description
stringlengths 2.98k
3.35M
| abstract
stringlengths 94
10.6k
| cpc
int64 0
8
|
|---|---|---|
FIELD OF INVENTION
The present invention relates generally to a valve stem for a pneumatic tire and more specifically to a valve stem which is capable of allowing for the introduction of pulverulent matter into the tire directly through the valve while at the same time also being capable of filtering the air released from within the tire through the valve core to prevent pulverulent matter contained within the tire from entering the valve core seat assembly and the atmosphere. The present invention also prevents pulverulent matter which may be contained within a tire from being forced into the valve core over time through use of the tire and due to routine checking of tire air pressure.
BACKGROUND OF THE INVENTION
It is becoming increasingly popular to purposely introduce particulate or pulverulent matter into a tire to affect the tire characteristics. This application involves introducing a powder of specific composition into the tire to dynamically "balance" the tire and to reduce radial and lateral force variations found within a tire under varying load conditions. This method is taught and described in applicant's prior U.S. Pat. No. 5,073,217 and applicant's copending application Ser. No. 08/184,735, both of which are herein incorporated by reference. The particulate composition is sold by International Marketing, Inc. under the trademark "EQUAL®."
These various powders and substances may cause loss of air through the tire valve core, especially upon the checking of tire air pressure. The small size of the particles allows the particles to enter the valve core assembly and these particles may adversely affect the valve core components or their operation. Furthermore, it is desirable to prevent these installed substances from escaping the tire. By preventing the escape of the pulverulent powder, the powder does not enter the atmosphere and does not need to be replenished when the tire is re-inflated.
The EQUAL® tire balancing formula is often placed within new tires before the valve core is installed and before the tire is inflated. However, to introduce particulate compositions into an installed tire, it saves time and effort and is generally desirable to introduce such substances directly into a tire which already has a tire valve installed and which may already be partially or fully inflated. This is accomplished by introducing the powder or particulate matter directly into the valve under pressure such as in combination with compressed air to force the powder into the interior of the tire. A valve stem containing a simple screen or mesh to prevent valve core blockage upon tire air pressure checks does not allow such particulate matter to be introduced into the valve core seat because the screen or mesh blocks the particulate matter.
Also, it is not uncommon for a tire to contain other particulate matter such as dust, dirt, and as a consequence of use whereby particles of rubber become dislodged from the interior bead of the tire and freely move about the interior of the tire when the tire is in use. Over time, a large number of such particles may be found in any tire. It is not uncommon for these particles to enter into the tire valve core and prevent the valve from fully closing resulting in an air leak. This is especially likely to occur when air is released from the tire as the flow of air exiting the valve naturally draws the particles into the valve core.
SUMMARY OF THE INVENTION
The present invention is therefore directed to a tire valve specially designed to allow the relatively unimpeded flow of compressed air or a combination of compressed air and pulverulent matter into a tire while at the same time being capable of preventing any particulate or pulverulent matter contained within a tire from entering the tire valve core as is especially likely to occur when compressed air contained within the tire is vented through the valve core. The invention comprises an elongated valve body having a first end, a second end, and including a passageway formed therein, said passageway extending from said first end of said valve body to said second end of said valve body and said passageway defining an inlet port at said first end of said valve body for communication with a source of compressed air, and defining an outlet port at said second end of said valve body for communication with the interior of a tire; valve means disposed within said passageway for selectively blocking the flow of air through said passageway; a filter chamber, formed in fluid communication with said passageway between said first end and said second end of said passageway, said filter chamber having an upper region and a lower region wherein said upper region defines a filter seat; a filter element smaller in cross-sectional size relative to said filter chamber and disposed in an unbiased state within said filter chamber, said filter element capable of forming a selective seal with said filter seat to substantially preclude the passage of particulate matter when said filter element is forced adjacent to said filter seat; and, means for preventing said filter element from exiting said lower region of said filter chamber. The valve may be sized and configured for use with automobiles or light trucks, or it may be sized and configured for use with heavy duty trucks.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view showing the valve of the present invention as it may be installed in a wheel rim (the rim shown in ghost lines);
FIG. 2 is an enlarged elevational longitudinal cross-section of the present invention;
FIG. 2A is a greatly enlarged partial sectional view illustrating the valve operation as may occur when pressurized air contained within a tire is vented through valve;
FIG. 3 is a plan view as it may be taken at line 3--3 of FIG. 2; and
FIG. 4 is a greatly enlarged partial sectional view illustrating the operation of the valve as may occur when particulate matter is introduced into the valve in combination with compressed air.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the preferred embodiment of the present invention which is illustrated in the accompanying drawings. Referring to FIG. 1, the invention is shown generally at 10 and comprises an elongated valve body 12 having a first end 14 and a second end 16. First end 14 may contain external threads 15 to allow for the attachment of a protective cap or to allow for the attachment of a mating pneumatic fitting. Additional external threads 17 may be provided along the valve body to allow for attachment of valve body to wheel rim 20 using a nut (not shown). Second end 16 preferably contains an annular rubber seal 18 to provide for an airtight seal between second end 16 of valve body 12 and wheel rim 20. Many shapes and sizes and varieties of valve bodies are known in the art and the present invention is not meant to be limited to any particular valve body or any particular method of attachment with wheel rim 20. In particular, those skilled in the art will recognize that the disclosure and figures may apply equally to a valve sized and configured for use with automobile and light truck tires, as well a valve sized and configured for use with tires and wheels of heavy duty over-the-road and off-road trucks.
As seen in FIG. 2, a central passageway or bore 30 extends from first end 14 to second end 16 of valve body 12 Passageway 30 defines an inlet port 32 at first end 14 of valve body, and defines an outlet port 34 at second end 16 of valve body 12. Valve means which is preferably a pneumatic valve or valve core 40 is disposed in passageway 30. Valve core 40 is threadably secured at or near first end 14 of passageway 30 and depends from first end 14 into passageway. Valve pin 36 is biased by means of a spring to extend into inlet port 32 to be capable of being depressed by a mating pneumatic fitting or other implement as is known in the art to open valve core 40 to allow air to pass through passageway 30. It should again be noted that many such valve cores are known in the art, one such valve core being made by Schrader Automotive, Inc., Charlotte, N.C., and being commonly known in the industry as a Schrader Valve. The invention however is not meant to be limited to any particular type of valve core.
A filter chamber 50 is provided in fluid communication with passageway 30 and includes an upper portion or region defining a filter seat 55. In the preferred embodiment, outlet port 34 of passageway 30 defines the lower portion or region of filter chamber 50. Filter chamber 50 may be formed in communication with passageway 30 at any point along passageway 30 however is preferably formed between valve core 40 and outlet port 34 of passageway 30. Filter chamber 50 is preferably larger in cross-sectional diameter than passageway 30.
A filter element 60, which in the preferred embodiment is spherical in shape, is disposed in an unbiased manner within chamber 50. The spherical shape of filter element 60 is preferable because it allows filter element 60 to act similar to a ball check valve to form a selective seal with filter seat 55. Filter element 60 is smaller in cross-sectional size than filter chamber and in the preferred embodiment is made from sintered bronze although other suitable filtering materials as are known in the art may be employed. For example, filter element 60 may be formed of sintered stainless steel, sintered magnesium, sintered manganese, and other sintered metals formed using known powdered metallurgical techniques. In addition various nonmetallic filter media are well known in the art and are suitable for use with the present invention. Filter element 60 should allow for the passage of air but be substantially impervious to pulverulent matter. Cross-sectional size of filter element 60 should be small enough relative to the cross-sectional size of the filter chamber 50 to allow pulverulent material introduced into valve 10 through inlet port 32 to pass between walls of filter chamber 50 and filter element 60 when filter element 60 is unseated relative to filter seat 55.
As an alternative embodiment, filter chamber 50 may be frusto-conical in shape being of smaller cross-sectional diameter at its upper region and of larger cross-sectional diameter at its lower region. In such an embodiment, filter element 60 could be spherical or could be conical or frusto-conical. Filter element should be sufficiently small in cross-sectional size relative to filter chamber 50 to allow for the passage of pulverulent material between walls of filter chamber 50 and filter element 60 when filter is unseated relative to filter seat 55. However, in such an embodiment employing a frusto-conical filter chamber 50, and a conical or frusto-conical filter element 60, filter element 60 must be of sufficiently large dimensions such that filter element 60 does not tumble within chamber 50 and maintains the proper orientation relative to filter seat 55.
An occlusion means for preventing the escape of filter element 60 from lower portion of filter chamber 50 is shown in a preferred embodiment in FIGS. 2 and 3 as a wire 65 attached at opposite sides of outlet port 34 and spanning outlet port 34 to partially occlude or block the outlet port 34 of passageway 30. A first groove 70a and a second groove 70b may be disposed on opposite sides of outlet port 34 to accommodate wire 65. Subsequent to the placing of wire 65 in grooves 70a, 70b, grooves 70a, 70b may be deformed by means of a punch or otherwise to frictionally secure wire 65 therein. It is certainly recognized that wire 65 may be attached by numerous means known in the art and various occlusion means serving an equivalent purpose to wire 65 may be employed. One such equivalent occlusion means would involve forming the lower region of filter chamber 50, which in the preferred embodiment also functions as outlet port 34, to have an outer diameter which may be larger than the cross-sectional size of filter element, and an inner diameter smaller than the cross-sectional size of filter element 60 and having a perimeter of a shape which does not correspond to the shape of filter element 60. For example, lower region of filter chamber 50, which is preferably outlet port 34, could be formed having a serrated perimeter such that the teeth extend into outlet port 34 to provide an inner diameter (as measured between the points of opposing teeth) which confines filter element 60 while air and pulverulent material could pass through the gaps found between the teeth of the serrated perimeter.
In operation, the invention 10 is installed in a tire wheel rim 20 using the same methods as would be used to install a conventional tire valve stem. A tire is also mounted on rim 20. Filter element 60 is disposed in filter chamber 50 in an unbiased state and will only lie adjacent to filter seat 55 (FIG. 2 and FIG. 2A) if tire contains sufficient internal air pressure to force filter 60 adjacent to filter seat 55 or if gravity or other force such as centrifugal force pushes or pulls filter element 60 adjacent to filter seat 55. When valve pin 36 is depressed and compressed air is introduced into inlet port 32 as occurs when a tire is pressurized using methods known in the art, the pressure forces the filter element 60 away from filter seat 55 (FIG. 4) if it is not already naturally away from filter seat 55 and the compressed air and any pulverulent matter of sufficiently small size is allowed to enter the interior of tire through valve 10.
As seen in FIG. 4, a majority of the compressed air and any pulverulent matter contained within the stream of compressed air passes around the filter element 60 and between the filter element 60 and the walls of the filter chamber 50 to enter the tire through outlet port 34. A small amount of the compressed air introduced into inlet port 32 may pass through filter element 60 before entering the tire, although filter element 60 would deflect any pulverulent matter so that it travels around filter element 60. The small amount of compressed air which does travel through filter element 60 dislodges much of the particulate matter which may be contained on the surface of or within filter and in this manner, filter element is self-cleaning. If pulverulent matter is introduced into the tire through valve 10, it is desirable to subsequently introduce a short blast of compressed air free of any pulverulent matter into inlet port 32 to flush the valve stem passageway 30 of any residual pulverulent matter.
When tire is pressurized, forces, such as the internal air pressure of the tire, push or bias filter element 60 into upper region of filter chamber 50 and adjacent to filter seat 55. Other forces such as centrifugal force caused by the rolling of the tire and gravity, if the tire is at rest, may also force filter element 60 adjacent to filter seat 55. Filter element 60 forms a selective seal with filter seat 55 which substantially prevents the passage of pulverulent matter between filter element 60 and filter seat 55 although air may pass between filter element 60 and filter seat 55. Filter element 60 also does not allow for the passage of pulverulent matter but does allow the passage of air. In this manner, any pulverulent matter contained within tire or filter chamber 50 is prevented from passing into passageway 30 above filter chamber. This allows for air to be vented through inlet port 32 without any pulverulent matter contained within tire from entering valve core 40 or from exiting into the atmosphere.
In tires in which particulate compositions such as EQUAL® have not been installed, this invention also prevents any other particulate matter, such as dust, dirt, and small pieces of rubber which may be contained within the tire, from being forced into passageway and interfering with the flow of air or the operation of the valve core seat.
While the foregoing description has set forth the preferred embodiment of the invention in particular detail, it must be understood that numerous modifications, substitutions and changes can be undertaken without departing from the true spirit and scope of the present invention as defined by the ensuing claims.
|
The present invention relates generally to a valve stem for a pneumatic tire and more specifically to a valve stem which is capable of allowing for the introduction of pulverulent matter into the tire directly through the valve while at the same time also being capable of filtering the air released from within the tire through the valve core to prevent pulverulent matter contained within the tire from entering the valve core seat assembly and the atmosphere. The present invention also prevents pulverulent matter which may be contained within a tire from being forced into the valve core over time through use of the tire and due to routine checking of tire air pressure. The invention is suited for use with any size wheel and tire assembly including those found on automobiles, light trucks, heavy duty over-the-road trucks, and heavy duty off-road trucks.
| 8
|
[0001] This application claims the benefit of U.S. Provisional Application No. 60/592,393, filed Aug. 2, 2004, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to identifying proteins involved in mediating neuronal cell death. More specifically, this invention relates to identifying proteins involved in neuronal cell death induced by amyloid-beta protein and the use of such proteins in developing therapies for the treatment of neurodegenerative diseases, such as Alzheimer's disease.
BACKGROUND OF THE INVENTION
[0003] Alzheimer's disease (AD) is a progressive neurodegenerative disease resulting in senile dementia and afflicts four million people in the United States alone (see generally Sloe, TINS, 16:403-409 (1993); Hardy et al., WO 92/13069; Sloe, J. Neuropathol. Exp. Neurol., 53:438-447 (1994); Duff et al., Nature, 373:476-477 (1995); Games et al., Nature, 373:523 (1995)). Broadly speaking, the disease falls into two categories: late onset, which occurs in old age (65+ years); and early onset, which develops well before the senile period, i.e., between 35 and 60 years. In both types of disease, the pathology is the same but the abnormalities tend to be more severe and widespread in cases beginning at an earlier age. The disease is characterized by at least two types of lesions in the brain, senile plaques and neurofibrillary tangles. Neurofibrillary tangles are intracellular deposits of microtubule-associated tau protein consisting of two filaments twisted about each other in pairs. Senile plaques are areas of disorganized neuropil up to 150 microns across (visible by microscopic analysis of sections of brain tissue) and have extracellular amyloid deposits at the center. A principal component of such plaques is β-amyloid peptide (Aβ) (see Forsyth Phys. Ther., 78:1325-1331 (1998)). Additional proteins found in the plaques include laminin as described by Murtomaki et al., J. Neurosci. Res., 32:261-273 (1992), apoE, acetylcholinesterase, and heparin sulfate proteoglycans, as described by Yan et al., Biochim. Biophys. Acta, 1502:145-57 (2000).
[0004] Amyloid precursor protein (APP) is a synaptic single-pass transmembrane protein that is best known for its involvement in AD. In AD patients, amyloid plaques containing aggregated Aβ peptide appear in specific brain regions, triggering an inflammatory response, neuronal cell death, and gradual cognitive decline. One mechanism by which Aβ is derived from APP is cleavage of APP at an extracellular position (β site), followed by an unusual cleavage within the APP transmembrane segment (γ site), producing a fragment of 39-43 amino acids of APP.
[0005] Several mutations within the APP protein have been correlated with the presence of Alzheimer's disease (Goate et al., Nature, 349:704-06 (1991) (valine 717 to isoleucine); Harlin et al., Nature, 353:844-46 (1991) (valine 717 to glycine); Murrell et al., Science, 254:97-99 (1991) (valine 717 to phenylalanine); Mullan et al., Nature Genet., 1:345-47 (1992) (a double mutation changing lysine 595 methionine 596 to asparagine 595 leucine 596 )). Such mutations are thought to cause Alzheimer's disease by increased or altered processing of APP to Aβ, particularly processing of APP to increased amounts of the long form of Aβ (i.e., A1-42 and A1-43). Mutations in other genes, such as the presenilin genes PS1 and PS2, are thought to indirectly affect processing of APP to generate increased amounts of long form Aβ (Hardy, TINS, 20:154 (1997)). These observations indicate that Aβ, and particularly its long form, is a causative element in Alzheimer's disease (Velez-Pardo et al., Gen. Pharm., 31(5):675-81 (1998)).
[0006] The Aβ peptide has also been implicated in neuropathological defects seen in individuals inflicted with Down's syndrome. For example, almost all individuals with Down's syndrome, who have an extra copy of chromosome 21, show neuropathological changes similar to those seen in Alzheimer's disease, if they survive into their 40s. This has been attributed to excess production of β-amyloid protein, which is encoded by the APP gene on chromosome 21.
[0007] Several proteins have been investigated for possible interactions with Aβ. These include the receptor for advanced glycation endproducts, RAGE (see Yan et al., Nature, 382:685-91 (1996)), the scavenger receptor (Khoury et al., Nature, 382:716-719 (1996); and Paresce et al., Neuron 17:553-65 (1996)), the endoplasmic reticulum-associated amyloid-beta biding protein (ERAB) (Yan et al., Nature, 389:689-695 (1997)), α4 or α7 nicotinic acetylcholine receptor (Wang et al., J. Neurochem., 75:1155-1161 (2000) and Wang et al., J. Biol. Chem., 275:5626-5632 (2000)), and the low affinity p75 NGF receptor (see Yaar et al., J. Clin. Invest., 100:2333-2340 (1997)). Additionally, Aβ has been reported to mediate adhesion of cells in a 131-integrin subunit-dependent manner when coated onto plates. (Ghiso et al., Biochem. J., 288:1053-59 (1992); Matter et al., J. Cell Bio., 141:1019-1030 (1998)). However, the mechanism(s) by which Aβ may mediate neurodegeneration remains unclear. The existence and nature of other cellular proteins that may have roles in the process is also largely unclear.
[0008] Various signaling pathways have been implicated in the pathogenesis of AD, including, p38, erk and c-jun N-terminal kinases (JNK) kinase cascades. For example, chronic stimulation of the JNKs has been shown to cause neuronal cell death in several disease paradigms, including in vitro AD models. Additionally, it has been shown that expression of kinase-deficient JNK3 protects against Aβ-induced cell death. However, it is not entirely clear which of these pathways and/or the signaling molecules are the key players in the development of the disease. Accordingly, elucidation of the signaling pathways as well as the intermediates of those pathways will help in understanding the pathology of AD and in developing therapeutic strategies to combat AD.
SUMMARY OF THE INVENTION
[0009] This invention provides human proteins that play a role in neuronal cell death. In particular, this invention relates to identification of proteins that are involved in the Aβ-induced cell death pathway in an in vitro model for AD.
[0010] The present invention is based on the discovery and isolation of a human homolog of a previously described FISH adapter protein (FISH), from embryonic human cortical cells (HCC). This invention is further based on an observation that FISH is phosphorylated in response to neurotoxic forms of Aβ and is likely to serve as a signaling molecule in A13 induced neuronal cell death, as shown in an in vitro model for AD. FISH also interacts with other proteins, such as ADAM12, in mediating Aβ-induced cell death
[0011] The invention further provides screening methods for identifying agents that modulate Aβ induced cell death by contacting Aβ treated neuronal cells with a candidate agent, and detecting the survival rate of Aβ-treated cells in the presence of the agent relative to the survival rate in the absence of the agent. The cells can be contacted with the agent either sequentially or simultaneously with Aβ. It is understood that the cells are contacted with a neurotoxic form of Aβ, as described herein, in order to induce cell death.
[0012] In certain embodiments, the screening method for identifying agents that modulate Aβ induced cell death employs two populations of cells: a first population that overexpresses FISH protein and a second population that expresses less FISH protein or no FISH protein. Both populations are treated with Aβ and either sequentially or simultaneously with a candidate agent. The rate or amount of cell death is compared between the two populations. An agent that has a greater effect (either positive or negative) on the cells that overexpress FISH is likely to modulate the activity of the one or more components of the FISH-mediated cell death pathway.
[0013] In certain embodiments, the screening method for identifying agents that modulate Aβ induced cell death measures the effect of a candidate agent on Aβ-induced phosphorylation of FISH protein.
[0014] In certain embodiments, the screening method for identifying agents that modulate Aβ induced cell death measures the effect of a candidate agent on Aβ-induced phosphorylation of ADAM12 protein.
[0015] In various embodiments, the screening method for identifying agents that modulate Aβ induced cell death measures the effect of a candidate agent on Aβ-induced cleavage of ADAM12 protein.
[0016] In certain embodiments, the screening method for identifying agents that modulate Aβ induced cell death measures the effect of a candidate agent on Aβ-induced changes in FISH protein localization.
[0017] Generally, an agent that modulates Aβ-induced cell death in a method of the invention, can be a compound that inhibits one or more activities of Aβ, including but not limited to, for example, phosphorylation of a FISH adapter protein by Aβ, interaction of FISH with members of the ADAM family of proteins, and cleavage of ADAM12.
[0018] In some embodiments, an agent is an antibody which binds FISH, thereby blocking the Aβ induced cell death pathway involving FISH. In other embodiments, such an antibody is an antibody that binds a FISH interacting protein involved in the Aβ induced cell death pathway. Examples of FISH interacting proteins include, but are not limited to, ADAM12. An antibody can be a monoclonal or a polyclonal antibody.
[0019] In certain embodiments, agents can also be nonantibody peptides and polypeptides, nucleic acids, lipids, carbohydrates, and small molecules that can modulate Aβ-induced cell death.
[0020] The present invention provides methods for modulating Aβ-induced neuronal cell death by administering an effective amount of a mutant form of a FISH interacting protein, such as, for example, a mutant of ADAM12 lacking metalloproteinase activity, to Aβ treated cells. In some embodiments, the mutant ADAM is a deletion mutant. In certain embodiments, the mutant ADAM12 protein is administered directly to the cell. In some embodiments, the mutant ADAM12 protein is encoded by a nucleic acid administered to the cell.
[0021] The present invention also provides methods for modulating Aβ-induced neuronal cell death by administering an effective amount of a mutant FISH protein. In certain embodiments, the invention provides a method for preventing Aβ-induced neuronal cell death by administering an effective amount of a dominant negative mutant of FISH protein. In certain embodiments, the mutant FISH protein is administered directly to the cell. In some embodiments, the mutant FISH protein is encoded by a nucleic acid administered to the cell.
[0022] According to the invention, an agent identified by the methods of the invention can be administered to a patient, in a therapeutically effective dose, in order to treat or prevent Aβ-induced cell death. Embodiments include treatment of AD.
[0023] The invention further provides agents that disrupt the interaction of FISH with other proteins, such as members of the ADAM family, where the interaction plays a role in Aβ-induced cell death.
[0024] The invention also provides methods of treating or preventing AD in a patient by administering an agent that modulates Aβ-induced cell death, for example, by blocking phosphorylation of FISH, blocking the interaction of FISH with a FISH interacting-protein, such as, ADAM12, or decreasing ADAM12 cleavage. Such agents include, but are not limited to, antibodies, nonantibody peptides and polypeptides, nucleic acids, lips, carbohydrates, and small compounds.
[0025] In some methods, the dosage of antibody can be about 0.01 to about 10 mg/kg body weight of the patient.
[0026] In some methods, an agent can be administered with a carrier as a pharmaceutical composition.
[0027] In some methods, an agent can be administered intraperitoneally, orally, intranasally, subcutaneously, intrathecally, intramuscularly, topically or intravenously.
BRIEF DESCRIPTION OF THE FIGURES
[0028] FIG. 1 shows a western blot depicting the cross-reactivity of a protein (p165) in lysates of cultured human cortical cells with an anti-pY845EGFR antibody in the presence or absence of an Aβ peptide (lanes 3 and 4). The western blot also shows the disappearance of cross-reactivity of the p165 protein with the anti-pY845EGFR antibody in lysates of cultured human cortical cells, when the lysates are pretreated with a phosphotyrosine-specific phosphatase (LAR) (lanes 1 and 2).
[0029] FIG. 2A is a flow-chart depicting the various steps involved in the purification of the p165 protein. FIG. 2B (lanes 1-6) shows a western blot with eluates from various steps of a protein purification protocol to purify p165 from whole cell lysates of cultured human cortical cells treated with Aβ. The western blot depicts enrichment of the eluates for the p165 protein, detected with an anti-pY845EGFR antibody.
[0030] FIG. 3 is a schematic representation of the p165 protein, identified as a human homolog of the mouse FISH adapter protein, which includes a Phox homology (PX) domain and five Src homology 3 (SH3) domains. Two peptides corresponding to amino acid residues 402-411 and 739-751 were sequenced.
[0031] FIG. 4A shows a western blot depicting the immunoprecipitation of endogenous FISH from cultured human cortical cells and the phosphorylation of FISH in the presence of Aβ, as detected with an anti-pY845EGFR antibody. FIG. 4B shows a western blot depicting the phosphorylation of FISH protein expressed from an adenovirus construct in cultured human cortical cells upon treatment with Aβ, as detected with an anti-pY845EGFR antibody.
[0032] FIG. 5 shows western blots depicting the phosphorylation of Phox homology deletion mutants of FISH (14FL-includes a deletion of 166 amino acids from the N-terminus of FISH; 615-includes a deletion 347 amino acids from the N-terminus of FISH) in an Aβ-independent manner.
[0033] FIGS. 6A-6C are micrographs depicting inverted images of epidermal growth factor protein (EGFP) positive neurons expressing deletion mutants of FISH.
[0034] FIG. 7 is a bar graph showing the survival rate of neuronal cells infected with mutant forms of FISH expressed by adenovirus constructs.
[0035] FIGS. 8A-8D are immunofluorescence images of HCC cells showing the localization of FISH in the presence and absence of Aβ, as detected using an antibody to FISH.
[0036] FIG. 9A shows a western blot depicting the expression of ADAM12 and ADAM19 in lysates of cultured human cortical cells either left untreated (C) or in cells treated for about 18 hours with A13 (T). FIG. 9B shows a western blot depicting the degradation of heregulin (HRG) in lysates of cultured human cortical cells either left untreated (C) or in cells treated for about 18 hours with Aβ (T).
[0037] FIGS. 10A-10F are micrographs of inverted images of EGFP-positive neurons ( 10 D) and EGFP-positive neurons expressing a deletion mutant of FISH (FISH 348-1105) ( 10 A), which further express ADAM12 deletion mutants: ADAM12del 198-415 in 10 B and 10 E and ADAM12del 198-501 in 10 C and 10 F.
[0038] FIGS. 11A-11F are micrographs of inverted images of neurons, either left untreated ( 11 A, B, and C) or treated with Aβ ( 11 D, E, and F), and further expressing either ADAM12del 198-501 in 11 A and D, EGFP in 10 B and E, or ADAMdel 198-415 in 11 C and F.
DETAILED DESCRIPTION OF THE INVENTION
[0039] In order that the present invention be more readily understood, certain terms are first defined. Additional definitions are set forth throughout the detailed description.
[0040] The term “antibody” refers to an immunoglobulin, or a fragment thereof, and encompasses any polypeptide comprising an antigen-binding site. The term includes, but is not limited to, polyclonal, monoclonal, monospecific, polyspecific, non-specific, humanized, human, single-chain, chimeric, synthetic, recombinant, hybrid, mutated, grafted, and in vitro generated antibodies. It also includes, unless otherwise stated, antibody fragments such as Fab, F(ab′) 2 , Fv, scFv, Fd, dAb, and other antibody fragments which retain the antigen binding function.
[0041] The terms “Aβ” and “Aβpeptide” refer to the beta-amyloid protein which is a proteolytic product of the amyloid precursor protein (APP). Aβ is found in senile plaques of brains of individuals affected with Alzheimer's disease (AD) and triggers neuronal cell death, which can be assayed by one or more methods described herein.
[0042] The term “ADAM” refers to disintegrin-like and zinc-dependent metalloproteinases that belong to a large protein family. These proteins share all or some of the following domain structure: a signal peptide, a propeptide, a metalloproteinase, a disintegrin, a cysteine-rich and an epidermal growth factor (EGF)-like domain, a transmembrane region, and a cytoplasmic tail. ADAMs are widely distributed in many organs, tissues, and cells, such as brain, testis, epididymis, ovary, breast, placenta, liver, heart, lung, bone, and muscle. These proteins are capable of at least four potential functions: proteolysis, adhesion, fusion, and intracellular signaling, and have been implicated in many diseases. ADAM12, 15, and 19 are members of this family of proteins that have been previously shown to interact with FISH, in particular with the fifth SH3 domain of FISH. (Abram et al., J. Biol. Chem. 278: 16844-16851 (2003)).
[0043] The term “Aβ activity” refers to at least one cellular process interrupted or initiated by an Aβ peptide. This term includes signaling pathways involved in Aβ-induced cell death. Generally, Aβ activities include, but are not limited to, tyrosine phosphorylation of FISH, interaction of FISH with FISH interacting proteins, such as ADAM12, and cleavage of ADAM 12, However, an Aβ activity can be any response initiated upon exposure of neuronal cells to a toxic form of Aβ peptide, including, induction of cell death, both in vivo and in vitro.
[0044] The terms “FISH” and “FISH adapter protein” refer to a scaffolding protein that contains Five SH3 domains. FISH was first identified as a substrate of the Src protein tyrosine kinase. (Lock et al., The EMBO J., 17: 4346-4357 (1998)). It also contains a Phox homology (PX) domain at the amino-terminus. The fifth SH3 domain has been shown to interact with members of the ADAM family, including, ADAM12, 15, and 19. (Id.)
[0045] The nucleic acid sequence of a murine FISH is provided in SEQ ID NO:1 (Genbank Accession Number AJ007012); the amino acid sequence is provided in SEQ ID NO:2.
[0046] The term “FISH interacting protein” refers to proteins that cohere with FISH. The term also refers to any variants of such proteins (including splice variants, truncations, fragments, substitutions, addition and deletion mutants, fusion proteins, shuffling sequences and motif sequences, and homologs) that have one or more of the biological activities associated with native proteins, or show disruption of a biological activity associated with the native protein. These proteins further include amino acid sequences that have been modified with conservative or non-conservative changes to the native proteins. These proteins may be derived from any source, natural or synthetic. A FISH interacting protein may either stimulate Aβ-induced cell death or inhibit Aβ-induced cell death. Examples of FISH interacting proteins include members of the ADAM family of proteins, including, ADAM12, 15 and 19, and variants of such proteins, including deletion mutants, such as the ADAM12 deletion mutants described in the Examples herein.
[0047] The nucleic acid sequence of a human ADAM12 is provided in SEQ ID NO:3 (GenBank Accession Number BC060804); the amino acid sequence is provided in SEQ ID NO:4.
[0048] Additional FISH-interacting proteins can be identified by methods described herein or those well known in the art. For example, co-immunoprecipitation or two-hybrid systems can be used to identify proteins that interact with FISH, which may be involved in the Aβ induced cell death pathway mediated by FISH.
[0049] A deletion in a FISH or an ADAM12 protein can be made anywhere in the protein as desirable. A deletion may occur anywhere within the protein; for example, N-terminus, C-terminus or any other part of a FISH protein or an ADAM12 protein. An amino acid deletion according to the invention comprises the removal of at least one amino acid from the N-terminus of a FISH protein. In some embodiments, a deletion comprises removal of at least one amino acid from the C-terminus of a FISH protein. In yet another embodiment, a deletion comprises removal of one or more amino acids from a region lying between the N-terminal end and the C-terminal end of a FISH protein. In one embodiment, such a deletion involves the removal of an entire PX domain of a FISH protein. In certain embodiments, such a deletion involves the removal of an entire SH3 domain of a FISH protein. For example, FISH proteins of the invention comprising a deletion include FISH proteins that have the PX domain deleted or FISH proteins that have one or more of the SH3 domains deleted. Similarly, ADAM proteins can include a deletion of one or more amino acid at the N-terminus, the C-terminus or anywhere in between. Such a deletion may also include the deletion of one or more entire domains, for example, the metalloproteinase domain. Deletions can be generated directly in the FISH or ADAM12 amino acid sequence to make a deletion mutant of the corresponding protein, or they may be generated in a polynucleotide sequence encoding the FISH or ADAM12 protein, thereby making a nucleic acid encoding a deletion mutant of the corresponding protein.
[0050] The term “inhibit” or “inhibition” of Aβ activity refers to a reduction, inhibition of otherwise diminution of at least one activity of Aβ due to an agent that effects either phosphorylation of FISH, interaction of FISH with one or more of the FISH interacting proteins, such as ADAM12, or cleavage of ADAM12. Inhibition of a activity does not necessarily indicate a complete negation of Aβ activity. A reduction in activity can be, for example, at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or more. In certain embodiments, inhibition can be measured by a decrease in FISH phosphorylation. In certain embodiments, the inhibition can be measured by a decrease in ADAM12 cleavage. In some embodiments, the inhibition can be measured by a decrease in heregulin degradation. Generally, inhibition of Aβ activity can simply be detected by a decrease in cell death or an increase in cell survival after treatment of cells with an agent, as measured by one or more assays provided herein.
[0051] In some embodiments, inhibition of an Aβ activity can be measured, for example, by the difference in the activity before and after exposure of Aβ-treated neuronal cells to a suitable agent. The agent can be chosen from an antibody, a non-antibody polypeptide, a nucleic acid molecule, a carbohydrate, and a small molecule. Examples of antibodies include, but are not limited to, an antibody to FISH and/or a FISH interacting protein such as ADAM12. Examples of non-antibody polypeptides include, for example, deletion or substitution mutants of FISH and/or FISH interacting proteins, including dominant negative mutants of FISH and/or FISH interacting proteins. Examples of nucleic acid molecules include, for example, polynucleotides encoding deletion or substitution mutants of FISH and/or FISH interacting proteins, including dominant negative mutants of FISH and/or FISH interacting proteins. Additionally, antisense molecules and/or iRNA can be used as agents, where such antisense molecules hybridize to mRNA encoding FISH and/or a FISH interacting protein, thereby blocking the Aβ induced cell death pathway involving FISH and/or a FISH interacting protein.
[0052] The term “treating” or “treatment” refers to both therapeutic treatment and prophylactic or preventative measures. Those in need of treatment can include individuals already having a particular medical disorder, as well as those who may ultimately acquire the disorder (i.e., those needing preventative measures). Treatment can regulate Aβ activity or the level of Aβ to prevent or ameliorate clinical symptoms of at least one disease. The inhibitors and/or antibodies can function by, for example, preventing the phosphorylation of FISH, by blocking the interaction of FISH and its interacting proteins, such as ADAM12, and/or by reducing or blocking cleavage of ADAM12.
[0053] The term “patient” includes human and other mammalian subjects that receive either prophylactic or therapeutic treatment.
[0054] In the experiments leading to the present invention, a human homolog of the mouse FISH adapter protein (FISH) was isolated from cultured human cortical cells (HCC), which serve as an in vitro model for AD. Additionally, proteins that interact with FISH to mediate Aβ-induced cell death were also identified. An anti-phosphoTyrosine845 Epidermal Growth Factor Receptor (EGFR) antibody detected a phosphorylated form of FISH on western blots that was specific to cells treated with Aβ, thereby suggesting that phosphorylation of FISH can be induced by Aβ.
[0055] A similar approach can be used to identify other proteins, whose phosphorylation is induced by Aβ.
[0056] The invention further provides assays for identifying agents that modulate Aβ-induced cell death using an in vitro model for AD. Of particular interest are those agents that reduce or prevent Aβ-induced cell death. For example, in one embodiment, human cortical cultures (HCC) can be treated with Aβ, followed by treatment of cells with various agents to monitor their effect on the survival rate of such cells. Agents include, but are not limited to, antibodies that bind FISH and antibodies that bind ADAM12.
[0057] The present methods are useful for the prophylactic or therapeutic treatment of several diseases and conditions that are characterized by the presence of Aβ peptide. Such diseases include, for example, AD, Down's syndrome and cognitive impairment, type II diabetes, Parkinson's disease, amyloidoses such as hereditary or systemic amyloidoses, and diseases caused all or in part by prion infection.
[0058] Patients amenable to treatment include individuals at risk of disease but not showing symptoms, as well as individuals presently showing symptoms. In the case of AD, virtually anyone is at risk of suffering from AD if he or she lives long enough. The present methods are useful for individuals who have a known genetic risk of AD. Such individuals include those having relatives who have experienced this disease, and those whose risk is determined by analysis of genetic or biochemical markers. Genetic markers of risk toward AD include mutations in the APP gene, for example mutations at position 717 and positions 670 and 671 referred to as the Hardy and Swedish mutations, respectively (see Hardy, TINS, supra). Other markers of risk are mutations in the presenilin genes, PS1 and PS2, and the gene for ApoE4, family history of AD, hypercholesterolemia, or arteriosclerosis. Individuals presently suffering from AD can be recognized from characteristic dementia, as well as the presence of the risk factors described above. In addition, a number of diagnostic tests are available for identifying individuals who have AD. These include measurement of cerebrospinal fluid (CSF) tau and Aβ42 levels. Elevated tau and decreased Aβ42 levels signify the presence of AD. Individuals suffering from AD can also be diagnosed by ADRDA criteria. In asymptomatic patients, treatment can begin at any age (e.g., about 10, about 20, about 30). Usually, however, it is not necessary to begin treatment until a patient reaches about 40, about 50, about 60, about 70, about 80 or about 90. Treatment typically entails multiple dosages over a period of time. In the case of Down's syndrome patients, treatment can begin prenatally by administering therapeutic agents to the mother; or treatment may begin shortly after birth.
[0059] In prophylactic applications, pharmaceutical compositions or medicaments can be administered to a patient susceptible to, or otherwise at risk of developing AD, in an amount sufficient to eliminate or reduce the risk, lessen the severity, or delay the onset of the disease, including biochemical, histological and/or behavioral symptoms of the disease, its complications and intermediate pathological phenotypes presenting during development of the disease.
[0060] In therapeutic applications, compositions or medicaments can be administered to a patient suspected of, or already suffering from a disease in an amount sufficient to cure, or at least partially arrest, the symptoms or progression of the disease (biochemical, histological, and/or behavioral), including its complications and intermediate pathological symptoms. An amount adequate to accomplish therapeutic or prophylactic treatment is defined as a therapeutically- or prophylactically-effective dose. In therapeutic regimes, the agent can be administered at intervals until symptoms of the disease disappear or significantly decrease. Optionally, administration can be continued to prevent recurrence. In prophylactic regimes, agents can also be administered at intervals, in some instances for the rest of a patient's life. Treatment can be monitored by assaying levels of administered agent, or by monitoring the response of the patient. The response can be monitored by ADRDA criteria and imaging of plaques in the brain of the patient (see WO 00/14810).
[0061] Effective doses of the compositions of the present invention, for the treatment of the above-described conditions vary depending upon many different factors, including means of administration, target site, physiological state of the patient, whether the patient is human or an animal, other medications administered, and whether treatment is prophylactic or therapeutic. Usually, the patient is a human; nonhuman mammals, including transgenic mammals, can also be treated. Treatment dosages can typically be titrated to optimize safety and efficacy.
[0062] Dosages of antibodies, nonantibody peptides and polypeptides, lipids, carbohydrates, and small molecules can range from about 0.0001 to about 100 mg/kg, and more usually about 0.01 to about 20 mg/kg, of the host body weight. For example, dosages can be about 1 mg/kg body weight or about 20 mg/kg body weight or within the range of about 1 to about 10 mg/kg. An exemplary treatment regime entails administration once per every two weeks or once a month or once every 3 to 6 months. In some methods, two, three, four or more monoclonal antibodies with different binding specificities can be administered simultaneously, in which case the dosage of each antibody administered falls within the ranges indicated. An antibody can usually be administered on multiple occasions. Intervals between single dosages can be weekly, monthly or yearly. In some methods, dosage of antibody can be adjusted to achieve a plasma antibody concentration of about 1 to about 1000 μg/ml, and in some methods about 25 to about 300 μg/ml. Alternatively, antibody can be administered as a sustained release formulation, in which case less frequent administration is required. Dosage and frequency vary depending on the half-life of the antibody in the patient. In general, human antibodies show the longest half life, followed by humanized antibodies, chimeric antibodies, and nonhuman antibodies. The dosage and frequency of administration can vary depending on whether the treatment is prophylactic or therapeutic. In prophylactic applications, a relatively low dosage can be administered at relatively infrequent intervals over a long period of time. Some patients continue to receive treatment for the rest of their lives. In therapeutic applications, a relatively high dosage at relatively short intervals can sometimes be required until the progression of the disease is reduced or terminated, and preferably until the patient shows partial or complete amelioration of the symptoms of the disease. Thereafter, the patient can be administered a prophylactic regime.
[0063] Doses for nucleic acid agents can range from about 10 ng to 1 g, about 100 ng to about 100 mg, about 1 μg to about 10 mg, or about 30 to about 300 μg DNA per patient. Nucleic acids encoding mutant forms of FISH and/or FISH interacting proteins, such as ADAM12, can be linked to regulatory elements, such as promoters and enhancers, that allow expression of the mutant forms in a cell and/or a patient. In some embodiments, promoters/enhancers that specifically cause expression in the brain are used. Promoters such as platelet-derived growth factor (PDGF), prion, or the neural enolase promoter are examples.
[0064] The linked regulatory elements and coding sequences can be cloned into a suitable vector. A number of viral vector systems are available including retroviral systems (see, e.g., Lawrie and Tumin, Curr. Opin. Genet. Develop., 2:102-109 (1993)); adenoviral vectors (see, e.g., Bett et al., J. Virol., 67:5911 (1993)); adeno-associated virus vectors (see, e.g., Zhou et al., J. Exp. Med., 179:1867-75 (1994)), viral vectors from the pox family including vaccinia virus and the avian pox viruses, viral vectors from the alpha virus genus such as those derived from Sindbis and Semliki Forest Viruses (see, e.g., Dubensky et al., J. Virol., 70:508-19 (1996)), Venezuelan equine encephalitis virus (see U.S. Pat. No. 5,643,576), rhabdoviruses, such as vesicular stomatitis virus (see WO 96/34625), herpes simplex virus, and papillomaviruses (Ohe et al., Human Gene Therapy, 6:325-33 (1995); Woo et al., WO 94/12629; and Xiao & Brandsma, Nucleic Acids. Res., 24:2630-22 (1996)).
[0065] DNA can be packaged into liposomes. Suitable lipids and related analogs are described by U.S. Pat. Nos. 5,208,036, 5,264,618, 5,279,833, and 5,283,185.
[0066] Gene therapy vectors or naked DNA can be delivered in vivo by administration to an individual patient, typically by systemic administration (e.g., intravenous, intraperitoneal, nasal, gastric, intradermal, intramuscular, intrathecal, subdermal, or intracranial infusion) or topical application (see, e.g., U.S. Pat. No. 5,399,346). Vectors can include facilitating agents such as bupivacine (U.S. Pat. No. 5,593,970). DNA can also be administered using a gene gun. See Xiao & Brandsma, supra. The DNA is precipitated onto the surface of microscopic metal beads. the microprojectiles are accelerated with a shock wave or expanding helium gas, and penetrate tissues to a depth of several cell layers. For example, the Accel™ Gene Delivery Device manufactured by Agacetus, Inc., Middleton, Wis. is suitable. Alternatively, naked DNA can pass through skin into the blood stream simply by spotting the DNA onto skin with chemical or mechanical irritation (see WO 95/05853).
[0067] In a further variation, nucleic acids can be delivered to cells ex vivo, such as cells explanted from an individual patient, followed by reimplantation of the cells into a patient, usually after selection for cells that have incorporated the vector.
[0068] The effect of antisense agents can be evaluated on the expression of the target nucleic acid (e.g., FISH and/or a FISH interacting protein) in a cell expressing the target nucleic acid at measurable levels. This can be routinely determined using, for example, PCR or Northern blot analysis.
[0069] Agents of the invention can be administered by parenteral, topical, intravenous, oral, subcutaneous, intrathecal, intraarterial, intracranial, intraperitoneal, intranasal, or intramuscular means for prophylactic and/or therapeutic treatment. In some methods, agents can be injected directly into a particular tissue where Aβ deposits have accumulated, for example, by intracranial injection. In some methods, intramuscular injection or intravenous infusion can be employed for the administration of antibody. In some methods, particular therapeutic antibodies can be injected directly into the cranium. In some methods, antibodies can be administered as a sustained release composition or device, such as a Medipad™ device.
[0070] Agents of the invention can optionally be administered in combination with other agents. In the case of AD and Down's syndrome, in which amyloid deposits occur in the brain, agents of the invention can also be administered in conjunction with other agents that increase passage of the agents of the invention across the blood-brain barrier.
[0071] Agents of the invention can be administered as compositions comprising an active therapeutic agent and a variety of other pharmaceutically acceptable components. See Remington's Pharmaceutical Science (15th ed., Mack Publishing Company, Easton, Pa., 1980). The particular formulation employed depends on the intended mode of administration and the therapeutic application. The compositions can also include, depending on the formulation desired, pharmaceutically-acceptable, non-toxic carriers or diluents, which are defined as vehicles commonly used to formulate pharmaceutical compositions for animal or human administration. The diluent can be selected so as not to negatively impact the biological activity of the combination. Examples of such diluents include, but are not limited to, distilled water, physiological phosphate-buffered saline, Ringer's solution, dextrose solution, and Hank's solution. In addition, the pharmaceutical composition or formulation can also include other carriers, adjuvants, or nontoxic, nontherapeutic, nonimmunogenic stabilizers, and the like.
[0072] Pharmaceutical compositions can also include large, slowly metabolized macromolecules such as proteins, polysaccharides such as chitosan, polylactic acids, polyglycolic acids, copolymers (such as latex functionalized Sepharose™ beads, agarose, cellulose, and the like), polymeric amino acids, amino acid copolymers, and lipid aggregates (such as oil droplets or liposomes).
[0073] For parenteral administration, agents of the invention can be administered as injectable dosages of a solution or suspension of the substance in a physiologically-acceptable diluent with a pharmaceutical carrier that can be a sterile liquid such as water, oils, saline, glycerol, or ethanol. Parenteral compositions for human administration can be sterile, substantially isotonic, and made under GMP conditions. Additionally, auxiliary substances, such as wetting or emulsifying agents, surfactants, pH buffering substances, and the like, can be present in compositions. Other components of pharmaceutical compositions can be those of petroleum, animal, vegetable, or synthetic origin, for example, peanut oil, soybean oil, and mineral oil. Glycols, such as propylene glycol or polyethylene glycol, can be liquid carriers, for example, for injectable solutions. Antibodies can be administered in the form of a depot injection or implant preparation that can be formulated in such a manner as to permit a sustained release of the active ingredient. An exemplary composition comprises monoclonal antibody at 5 mg/mL, formulated in aqueous buffer containing 50 mM L-histidine (optional), 150 mM NaCl, adjusted to a suitable pH with HCl.
[0074] Compositions can be prepared as injectables, either as liquid solutions or suspensions; solid forms suitable for solution in, or suspension in, liquid vehicles prior to injection can also be prepared. The preparation also can be emulsified or encapsulated in liposomes or microparticles such as polylactide, polyglycolide, or copolymer for enhanced adjuvant effect, as discussed above (see Langer, Science, 249:1527-33 (1990) and Hanes et al., Advanced Drug Delivery Reviews, 28:97-119 (1997). The agents of this invention can be administered in the form of a depot injection or implant preparation that can be formulated in such a manner as to permit a sustained or pulsatile release of the active ingredient.
[0075] Additional formulations suitable for other modes of administration include oral, intranasal, and pulmonary formulations, suppositories, and transdermal applications. For suppositories, binders and carriers include, for example, polyalkylene glycols or triglycerides; such suppositories can be formed from mixtures containing the active ingredient in the range of about 0.5% to about 10%, or about 1% to about 2%. Oral formulations include, but are not limited to, excipients such as pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, and magnesium carbonate. These compositions can take the form of solutions, suspensions, tablets, pills, capsules, sustained release formulations or powders and contain about 10% to about 95% of active ingredient, or about 25% to about 70%.
[0076] Topical application can result in transdermal or intradermal delivery. Topical administration can be facilitated by co-administration of the agent with cholera toxin or detoxified derivatives or subunits thereof or other similar bacterial toxins (See Glenn et al., Nature, 391:851 (1998)). Coadministration can be achieved by using the components as a mixture or as linked molecules obtained by chemical crosslinking or expression as a fusion protein. Alternatively, transdermal delivery can be achieved using a skin patch or using transferosomes (Paul et al., Eur. J. Immunol., 25:3521-24 (1995); Cevc et al., Biochem. Biophys. Acta, 1368:201-15 (1998)).
[0077] The following examples provide various embodiments of the invention. One of ordinary skill in the art will recognize the numerous modifications and variations that can be performed without altering the spirit or scope of the present invention. Such modifications and variations are believed to be encompassed within the scope of the invention. The examples do not in any way limit the invention. It is understood that all of the numbers in the specification and claims are modified by the term about, as small changes in dosages, for example, would be considered to be within the scope of the invention.
EXAMPLES
[0078] The following materials and methods are for Examples 1-8, which follow.
[0079] Tissue Culture
[0080] Tissue culture plates were coated with polyethyleneimine (PEI) in 150 mM sodium borate, pH 8.5, and incubated overnight at room temperature. Prior to adding cells, the wells were washed with phosphate-buffered salene (PBS) and Minimal Essential Media (MEM with 10% fetal bovine serum (FBS)) was added until cells were ready for plating. Human fetal cerebral cortex (E13-E16) was rinsed with Hank's Balanced Salt Solution (HBSS). Tissue was triturated in 1 mg of DNAse in HBSS. This suspension was filtered through a 100 micron nylon cell strainer and centrifuged at 250×g for 5 minutes. The cells were resuspended in trypsin and incubated at 37° C. for 20 minutes. Modified Minimal Essential Media (MMEM with 10% FBS and 1 mg of DNase) was added and the cells were resuspended; then collected again by centrifugation. Cells were resuspended in MMEM containing B27, and plated in washed PEI-coated plates at 125,000 cells/well in 96 well plates or at 2.5 million cells/well in 6 well plates. The human cortical cultures (HCC) were incubated for 3 weeks with biweekly medium exchanges prior to treatment.
[0081] Aβ Generation
[0082] Aβ was generated by adding double distilled water (ddH 2 0) to Aβ to make up a 1 mM stock. This was aged for 3 days at 37° C., aliquoted, and stored frozen at −20° C. Soluble Aβ was made by adding DMSO to Aβ to make a 7.5 mM stock, sonicating for 30 minutes, aliquoting, and freezing at −20° C. Neurotoxic Aβ was generated by adding ddH 2 0 to Aβ, aliquoting, and freezing at −20° C.
[0083] FISH Immunoprecipitations from HCC Lysates
[0084] Cells were washed, lysed with 25 mM Hepes, pH 7.5, 1% Triton X-100, 0.1% SDS, 150 mM NaCl, 0.5 mM EDTA, 0.5 mM EGTA, and passed through a 26 gauge needle three times. Insoluble material was removed by centrifugation at 15,000 rpm for 15 minutes at 4° C. Lysates were pre-cleared on rabbit anti-mouse (RAM) antibody coupled to protein A beads and immunoprecipitated with FISH-specific antibodies or with antipY845EGFR antibodies. In certain experiments, HCC in 6 well plates were labeled with 100 μCi/ml 35 S-methionine in methionine-free medium overnight prior to lysis. In some experiments, FISH protein was phosphorylated with 32 P.
[0085] Aβ Immunofluorescence
[0086] HCC treated with Aβ for 72 hours were fixed with 4% paraformaldehyde, stained with 5 μg/ml anti-A6-3D6-biotin, and visualized with 10 μg/ml streptavidin-FITC (Jackson).
[0087] Aβ Neurotoxicity in Human Cortical Neurons
[0088] HCC were pretreated with antibodies or ligands (Please let us know whether HCC cells were treated with any antibodies and/or ligands in this case? If so, please provide the rationale behind using any antibodies and/or ligands and what these are, including the source) for 30 minutes in neuronal medium (MEM) supplemented with glutamine and penicillin/streptomycin (basal media). One micromolar Aβ in basal medium was added for 1 hour. The medium was removed and the HCC were treated with antibodies or ligands and 20 μM soluble Aβ in basal medium for 3 days. At three days, the toxicity was determined by incubating in 10% alamar blue in basal medium for two hours. Fluorescence levels were measured relative to control and Aβ treated wells in triplicate.
[0089] Aβ Induction of FISH Phosphorylation
[0090] Neurotoxic Aβ was added to HCC in 6-well plates in basal media supplemented with N-2 for 0 minutes to 24 hours. HCC was placed on wet-ice, washed with PBS, lysed with 25 mM Hepes, pH 7.5, 1% Triton X-100, 0.1% SDS, 150 mM NaCl, 0.5 mM EDTA, and 0.5 mM EGTA, and passed through a 26 gauge needle 3 times. Insoluble material was removed by centrifugation at 15,000 rpm for 15 minutes at 4° C. Lysates were precleared on protein A beads and FISH was immunoprecipitated using anti-FISH or an anti-pY845EGFR antibody and protein A beads. Immunoprecipitates were washed 3 times with 1 ml of 25 mM Hepes, pH 7.5, 1% Triton X-100 150 mM NaCl, 0.5 mM EDTA, and 0.5 mM EGTA. Immunoprecipitated samples were separated on 8% tris-glycine gels (Novex) and Western blotted with anti-phosphotyrosine 845 EGFR.
[0091] The present examples use an in vitro tissue culture model of Aβ plaques that form on hippocampal and cortical neurons in Alzheimer's disease (AD) and exhibit the associated neurotoxicity. The model uses primary human cortical neuronal cultures to represent the neurons effected in AD as closely as possible. Addition of Aβ to these cultures results in a reproducible A13 meshwork that forms over 1-3 days on the neurons and subsequently causes toxicity in the neurons. Aβ incubated on plates without HCC also stained as a meshwork but consistently showed a more uniform pattern with extensions that were shorter, thinner, and more linear than those seen on HCC.
Example 1
Identification and Purification of a Human Homolog of the Mouse FISH Adapter Protein
[0092] HCC cells were treated with Aβ, as discussed above, and the whole cell lysates were treated with an anti-phosphotyrosine-845 EGFR antibody to detect proteins that may be phosphorylated on tyrosine residues upon treatment of cells with Aβ. A western blot of the cell lysates revealed a phosphoprotein (p165) that appeared in HCC cells only upon treatment with Aβ, suggesting that phosphorylation of this protein was induced by Aβ. FIG. 1 shows a representative western blot of one such experiment which demonstrates cross-reactivity of the p165 protein with an anti-pY845EGFR antibody in presence of Aβ (lane 3). Immunoprecipitation of EGFR revealed that this protein was not phosphorylated EGFR but a yet unknown protein (data not shown). Treatment of cell lysates with a phosphotyrosine-specific phosphatase (LAR) resulted in a disappearance of the band corresponding to the p165 protein (lane 1)
[0093] An empirically defined protocol was used for the purification of p165 from whole cell lysates of HCC cells treated with Aβ. FIG. 2A shows a flow chart with the various steps used in the purification process and FIG. 2B shows a western blot that depicts enrichment of p165 in eluates obtained from various steps in the purification process.
[0094] The p165 protein was microsequenced and the deduced amino acid sequence was used to search known databases. (Please provide us with names of specific databases that were used. Also, please provide the sequence so that we can claim the protein.). The p165 protein was subsequently identified as a human homolog of a murine protein called FISH adapter protein. (Lock et al., The EMBO J., 17: 4346-4357 (1998)). A schematic representation of p165 is shown in FIG. 3 . Based on the deduced amino acid sequence of the p165 protein, the protein is predicted to have an N-terminal Phox-homology (PX) domain and five Src homology 3 (SH3) domains. The fifth Src homology domain of the mouse FISH(SH3 domain #5) has been previously reported to interact with members of the ADAM family of proteins, including ADAM12, ADAM15, and ADAM 19. (Abram et al., J. Biol. Chem., 278: 16844-16851 (2003)).
Example 2
FISH is Phosphorylated in HCC Cells in Response to Aβ Treatment
[0095] HCC cells were treated with Aβ, as discussed above, and endogenous FISH was immunoprecipitated, also as discussed above. Results of one such representative experiment are shown in FIG. 4 .
[0096] Immunoprecipitations and subsequent detection by western blotting were performed both in absence and presence of Aβ. FIG. 4 (lanes 1 and 2) depict a negative control where no FISH is detected, as expected. Lanes 3 and 4 show the presence of endogenous FISH both in Aβ treated and untreated HCC cells, as detected using an anti-FISH antibody. Lanes 5 and 6 show that FISH is phosphorylated on one or more tyrosine residues only upon treatment with Aβ. Accordingly, this experiment suggests that phosphorylation of endogenous FISH is induced by Aβ.
[0097] The results of this experiment were further substantiated by investigating the phosphorylation of exogenous FISH expressed in HCC from an adenovirus construct. As shown in FIG. 4B , Aβ treatment led to robust phosphorylation of adenovirally expressed FISH (lane 4).
Example 3
PX Deletion Mutants of FISH are Phosphorylated in an Aβ Independent Manner
[0098] In order to determine which domain(s) of FISH were involved in Aβ-induced phosphorylation of FISH, various mutant forms of FISH were generated. Two mutant forms carried deletions of the N-terminal PX domain. These were designated 14FL, which was missing the first 166 amino acids of FISH, and 615, which was missing the first 347 amino acids of FISH. These mutant forms were expressed in HCC cells either treated with Aβ or left untreated and subsequently immunoprecipitated FISH protein was subsequently detected by western blotting using the anti-phosphotyrosine-845 EGFR. As shown in FIG. 5 , both of the PX deletion mutants (14FL and 615) were phosphorylated independent of treatment with Aβ.
Example 4
The Presence of the Fifth SH3 Domain in Fish is Necessary but not Essential for Neurotoxicity and PX has a Protective Effect on the Neurons
[0099] Various N and C terminal mutant forms of FISH were generated and tested for their toxic effect on neurons. Initially, three mutant forms were tested. The FISH 981-1105 mutant form was missing the PX as well as the first four SH3 domains but contained the fifth SH3 domain, which has previously been reported to interact, with members of the ADAM family of proteins. The FISH 348-1105 mutant form was missing the PX domain, but included the third, forth, and fifth SH3 domains. The FISH 348-911 mutant form was missing the PX as well as the fifth SH3 domain.
[0100] FIG. 6 shows micrographs of inverted images of neurons that were infected with adenoviruses encoding the above-described FISH mutant forms. In all instances, the neurons were positive for epidermal growth factor protein, which was used as a marker for the infected cells. As shown in FIG. 6 , the neurons that were infected with the mutant forms that contained the fifth SH3 domain (FISH 981-1105 and FISH 348-1105) showed more cell death relative to the neurons that were infected with mutant forms that were missing the SH3 domain (FISH 348-911).
[0101] To further delineate the importance of the various domains on the effect of FISH on neurotoxicity, additional deletion mutants of FISH were generated. All the Mutant forms are summarized below in Table 1 along with the degree of neurotoxicity after neurons were infected with adenovirues encoding the various mutant forms.
[0000]
TABLE 1
FISH protein (amino acids)
Toxicity
FLPX (1-1105)
−
14FL (167-1105)
++
615 (348-1105)
++++
Hinc (348-911)
+
232 (981-1105)
+/−
14PCR (167-431)
−
14Sma (167-721)
+/−
[0102] As summarized in Table 1, the full-length FISH protein (FLPX) appeared to have little or no toxic effect on HCC, whereas the mutant forms that included the fifth SH3 domain were the most neurotoxic, in particular, 14FL and 651. Also, the 14PCR mutant form, which included the PX domain but was missing the fifth SH3 domain, also produced little or no toxicity. The results of one such experiment are also graphically depicted in FIG. 7 , which shows the percentage of cells that survived after being infected with adenoviruses encoding the various forms of FISH, relative to non-infected cells. The percentage survival of these cells was determined as described above in Materials and Methods.
Example 5
FISH Adapter Protein Re-Localizes in Cells Upon Treatment with Aβ
[0103] Tyrosine phosphorylation of FISH upon treatment with Aβ suggests that the Aβ neurotoxic signal may be mediated through FISH tyrosine phosphorylation. In order to further investigate the role of FISH in Aβ-induced cell death, HCC cells were examined for the subcellular localization of FISH in untreated cells as well as in cells that were treated for 6 hours with Aβ. Endogenous FISH was detected by immunofluorescence using a primary anti-FISH antibody followed by a Red Cy3 labeled anti-rabbit antibody. A blue DAPI stain was used to detect nuclei. The FISH adapter protein was re-localized in Aβ treated cells, as shown in FIG. 8A , compared to the localization in untreated cells, as shown in FIG. 8C .
Example 6
ADAM12 is Cleaved During Aβ-Induced Toxicity
[0104] Previously, it was reported that FISH, especially the fifth SH3 domain of FISH, interacts with members of the ADAM family of proteins, including ADAM12, 15, and 19. However, the significance, if any, of these interactions in Aβ-induced toxicity is unknown. Because the fifth SH3 domain of FISH appears to be important in Aβ-induced toxicity, as discussed above, the interaction of FISH with members of the ADAM family of proteins was investigated.
[0105] Self-cleavage of ADAMs accompanies activation of their protease activity. Western blotting for ADAM12 and 19 in whole cell lysates of HCC cells either left untreated or treated for 18 hours with Aβ, revealed that ADAM12 is in fact cleaved in cells treated with Aβ, suggesting that cleavage of ADAM12 and subsequent activation may play a role in Aβ-induced toxicity. The results of one such representative experiment are shown in FIG. 9A , which is a western blot depicting ADAM12 cleavage during Aβ-induced toxicity in HCC cells, as indicated by lower levels of ADAM12 in Aβ treated cells (lane 2), whereas levels of ADAM19 do not change in the presence or absence of Aβ (lanes 3 and 4).
[0106] That Aβ-induced toxicity is accompanied by cleavage and subsequent activation of ADAM12 was confirmed by investigating the degradation of heregulin (HRG), which is a transmembrane precursor protein known to be cleaved by metalloproteases of the ADAM family. Degradation of pro-HRG was investigated in HCC cells either left untreated or treated with Aβ. As shown in FIG. 9B , Aβ treatment induced degradation of pro-HRG relative to cells that were left untreated.
Example 7
ADAM12 Deletion Mutants Block FISH Induced Toxicity
[0107] As discussed above, the PX domain of FISH has a protective effect on neurons. However, FISH mutants containing the fifth SH3 domain are the most toxic. Since, the fifth SH3 domain has been shown to interact with members of the ADAM family and ADAM12 appears to be involved in Aβ-induced toxicity, the effect of ADAM12 deletion mutants that are missing the metalloprotease domain (ADAM12D198-415 and ADAM12D198-501) was investigated on the toxic effect of a FISH deletion mutant, which was missing the PX domain but contained the fifth SH3 domain.
[0108] HCC cells were either infected with an adenovirus encoding the FISH mutant (FISH 348-1105) or encoding EGFR, and subsequently infected with an adenovirus encoding either EGFR, ADAM12D198-415, or ADAM12D198-501. The effect on neuronal toxicity was examined. As shown in micrographs of the cells in FIG. 10 , the FISH mutant induced toxicity in the presence of Aβ, as evidenced by increased web-formation, relative to the cells transfected with EGFR alone ( 10 D). The cells expressing the ADAM12 deletion mutants appeared to have less web formation ( 10 B and 10 C), thereby suggesting that these mutants block the toxic effect of the FISH deletion mutant.
Example 8
ADAM12 Deletion Mutants Block Aβ Induced Toxicity
[0109] In addition to examining the effect of the ADAM12 deletion mutants on FISH induced toxicity, their effect on Aβ-induced neuronal toxicity was also examined. The results of a representative experiment are shown in FIG. 11 , which shows micrographs of HCC cells transfected with adenoviruses encoding various ADAM12 deletion mutants in both untreated cells and cells that had been treated with Aβ. As shown in FIG. 11 , the ADAM12 deletion mutants (ADAM12del 198-501 in 11 A and ADAM12del 198-415 in 11 F) blocked the toxic effect of Aβ.
[0110] All publications and patent applications cited above are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication or patent application were specifically and individually indicated to be so incorporated by reference. If the disclosure of any of the publications and patent applications incorporated by reference conflicts with the disclosure of the instant application, the instant application controls. Although the present invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be apparent that certain changes and modifications can be practiced within the scope of the appended claims.
[0111] Many modifications and variations of this invention can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. The specific embodiments described herein are offered by way of example only and are not meant to be limiting in any way. Unless otherwise indicated, all numbers expressing quantities of ingredients, cell culture, treatment conditions, and so forth used in the specification, including claims, are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated to the contrary, the numerical parameters are approximations and may very depending upon the desired properties sought to be obtained by the present invention. Unless otherwise indicated, the term “at least” preceding a series of elements is to be understood to refer to every element in the series. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.
|
The invention provides a novel human protein, FISH adaptor protein, involved in amyloid β-protein-mediated cell death. Also provided are methods for modulating amyloid β-protein-mediated cell death using agents that interfere with the activity of FISH adaptor protein.
| 2
|
BACKGROUND OF THE INVENTION
The invention herein described was made in the course of or under a contract thereunder with the United States Air Force Systems Command.
This invention relates to the preparation of Binor-S. More particularly, the invention relates to the preparation of Binor-S. from norbornadiene. Still more particularly, the invention relates to the catalytic dimerization of norbornadiene to Binor-S using a three-component catalyst system.
Binor-S, upon further processing, can be converted into a component of a high energy fuel which can be used in either jet or rocket propulsion. Jet propulsion includes a jet engine which can be used for a missile plane and others and includes the three basic types, i.e., ramjet, turbo-jet and pulse jet. The term rocket generally refers to a device containing its own oxygen or oxidizing agent.
Binor-S is known by the systematic chemical name of endo-cis-endo-heptacyclo(5.3.1.1 2 ,6.1 4 ,12.1 9 ,11.0 3 ,5.0 8 ,10)-tetradecane. Its melting point is about 65° C. It has a net volumetric heat of combustion of about 178,570 BTU/gallon.
Preparation of Binor-S is disclosed in an article in the Journal of the American Chemical Society, [88:21] Nov. 5, 1966, pages 4890-4894. The article is titled "π-Complex Multicenter Reactions Promoted by Binuclear Catalysts Systems. "Binor-S", a New Heptacyclotetradecane via Stereospecific Dimerization of Bicycloheptadiene", by G. N. Schrauzer, et al. Disclosed is the dimerization of bicycloheptadiene (also known as norbornadiene) to Binor-S using metal salts of cobalt carbonyl hydrides (e.g., Zn(Co(C0) 4 ) 2 ). A Lewis acid, such as AlBr 3 , can be used as a cocatalyst with the transition metal carbonyl catalyst. Another related article appears in Tetrahedron Letters, No. 8, 1970, pages 543-545 titled "New Catalysts of Stereospecific Norbornadiene Dimerization to "Binor-S", by G. N. Schrauzer et al. This second article discloses the use of RhCl[P(C 6 H 5 ) 3 ] 3 as a catalyst with BF 3 0(C 2 H 5 ) 2 as a cocatalyst for the dimerization of nobornadiene to Binor-S. The former two form a heterogenous catalyst system.
A metal-cobalt carbonyl complex useful as a catalyst in the polymerization of norbornadiene is disclosed in U.S. Pat. No. 3,679,722. Also, U.S. Pat. No. 3,676,474 discloses a multinuclear π-complex having at least two metal cobalt bonds which can be used as a catalyst in the dimerization of norbornadiene.
Catalytic dimerization of norbornadiene to Binor-S using a two component catalytic system of tris(triphenylphosphine) rhodium chloride and diethylaluminum chloride or ethylaluminum dichloride or aluminum ethylsesquichloride is disclosed in a related application, Ser. No. 631,978, filed Nov. 14, 1975, now U.S. Pat. No. 4,031,150.
Norbornadiene is also known as bicyclo(2.2.1)heptadiene-2,5. A method of preparation is disclosed in U.S. Pat. No. 2,875,256 issued February 24, 1959. Norbornadiene will be referred to as NBD hereinafter. NBD can be represented by either one of the following structural formulas: ##STR1##
During the dimerization of NBD more than one dimer is possible. G. N. Schrauzer, in his review "On Transition Metal-Catalyzed Reaction of Norbornadiene and the Concept of a Complex Multicenter Processes" in Advances on Catalysis 18, 373 (1968) Acad. Press, describes the fourteen theoretically possible dimers of NBD. And any and each of the dimers described therein have different physical and chemical properties.
Thus, a specific synthesis problem in the dimerization of NBD, as can be visualized from the fourteen theoretically possible isomers, is to obtain both excellent selectivity and conversion to the desired isomer at as low an economic cost as possible.
SUMMARY OF THE INVENTION
NBD is rapidly dimerized to Binor-S at both excellent selectivity and conversion. The dimerization requires a catalytic amount of a three component catalytic system of cobaltic acetylacetonate, triphenyl phosphine and diethylaluminum chloride or ethylaluminum dichloride or aluminum sesquichloride. The components are referred to hereinafter as CoA 3 , TPP, DEAC, EADC and EASC, respectively. The dimerization can occur at an ambient temperature.
The advantages of the present invention are as follows. Prior art methods are characterized by an extremely rapid exotherm, and to prevent runaway temperatures, high capacity heat exchange equipment is necessary. The investment cost and associated operating costs of this equipment adds substantially to the manufacturing cost of Binor-S. In contrast, present invention is not characterized by an extremely rapid exotherm and thus investment and operating cost savings are obtained.
Furthermore, the production of Binor-S from NBD is performed with both excellent selectivity and conversion. Furthermore, the reaction rate is rapid. Excellent selectivity and conversion, because the product is almost pure Binor-S, further facilitates the conversion of Binor-S to selectivity hydrogenated dimer mixtures having a ulitity as a high energy fuel. Since the product is mostly Binor-S the need to separate it from unreacted feed or other dimers or other compounds is minimized or obviated. Furthermore, the reaction occurs at a relatively low temperature and a relatively low pressure, both of which reduce relative manufacturing costs. By itself Binor-S also may have utility as a solid fuel.
DESCRIPTION
The catalytic dimerization of essentially NBD via present invention can be represented by the following formula reaction: ##STR2## compound I is NBD while compound II is Binor-S which is also a C 14 H 16 heptacyclic dimer of NBD. The structure of II is also often shown as follows: ##STR3## The NBD feed may contain a nominal amount of similar hydrocarbons; however, which if present should not be of a type which would adversely effect the reaction. If the NBD feed contains such undesirable hydrocarbons they can be removed by known means.
The Binor-S product can be separated from the other materials, that is unreacted NBD and the catalyst and other hydrocarbon. Also reaction A may also form nominal amounts of other dimers as well as heavier compounds. These heavier compounds as well as any unreacted feed and catalyst can be separated from the product by distillation, if necessary. An alternative procedure is that the catalyst can be deactivated by the addition of a hydroxylic solvent, e.g., methanol. This results in formation of two distinct layers which can be separated and then Binor-S can be distilled from other hydrocarbons, if necessary. Another separation procedure is crystallization from the quenched reaction product by cooling.
Generally the product from reaction A contains a major amount of Binor-S. Or expressed another way, a majority of the norbornadiene is dimerized to Binor-S. If the reaction is permitted to run for sufficient time then the product can contain substantial amounts of Binor-S. Based on the runs reported hereinafter the product can contain Binor-S in an excess of 90 mole %, however, a yield in excess of 80 mole % could also be economically acceptable. Again expressed another way the amount of norbornadiene dimerized to Binor-S can be in excess of at least 80 mole % and even in excess of 90 mole %. Such higher values are preferred.
The catalytic system favoring the aforementioned dimerization reaction A contains three components. The three are CoA 3 , TPP and DEAC, EADC or AESC. The amount present is a catalytic amount so that a suitable conversion to Binor-S occurs and the selectivity as to Binor-S is sufficient. Material, which during the dimerization reaction could adversely effect the catalyst system, should not be present. For example, the presence of hydroxylic compounds such as water, alcohol or oxygen from air could deactivate the catalyst system.
Selectivity refers to the amount of particular compound formed divided by the amount of all compounds formed. Conversion to the dimer is the amount of total dimer formed divided by the sum of the total dimer plus unreacted feed. From a commercial standpoint economics of an overall process determines the optimal levels for both the selectivity and conversion.
The reaction time required for an economically satisifactory selectivity and/or conversion depend on a number of factors, such as catalyst to NBD ratio, as well as operating conditions. Also the economics depend on capital investment versus conversion per pass and the like . The catalyst to NBD ratios are discussed hereinafter while typical conditions are provided by the Examples.
An inert solvent can be used in the dimerization reaction. Since the reaction is mildly exothermic the solvent can serve as a heat sink. It can also assist in solubilizing the reaction components, that is the feed and the components of the catalyst and thereby provide for a homogeneous reaction medium. Some solvent can be added to the system as a carrier for one or more of the catalyst components. For example, DEAC is often maintained in a solvent such as toluene. Furthermore the solvent should not adversely react with the feed, products or catalyst, therefore it should be inert. Also, presence of the solvent can facilitate the handling of the reaction mixture. Classes of suitable inert solvents include aromatic hydrocarbons, cycloparaffins, cycloolefins, ethers, halogenated aromatics, halogenated paraffins and halogenated cycloparaffins. Specific examples include benzene, toluene, xylenes, cyclohexane, cyclopentadiene, diethylether, chlorobenzene, bromobenzene, chlorinated cyclohexane and the like. As to the amount of solvent used, excessive amounts decrease the reaction rate, and thus adversely affect the economics for a commercial operation. However, reaction A can take place without a solvent.
The dimerization of NBD with the three-component catalyst system can occur at ambient temperature. Thus the temperature of the homogeneous NBD-catalyst system mixture need not be raised to initiate reaction A. Of course, if the mixture is at an extremely low temperature, then heating of the cooled mixture could be necessary. However, once reaction A is underway, some heat is generated and the temperature of the mixture increases. If the temperature increases too much then some cooling would be required. Generally, however, the dimerization of NBD with the three-component catalyst system is not characterized by an extremely rapid exotherm.
Selective dimerization of the NBD occurs in a liquid phase therefore it is not desirable to have the reaction temperature largely exceed the boiling points of the NBD and/or solvent. Conversely, if the temperature is too low the reaction rate would be too low to be economically feasible. An operable temperature range is between from about 0° C. to about 150° C. with about 10° C. to about 100° C. a preferred range. The operating pressure can vary substantially, however, it can range from about atmospheric up to about 2000 psi with 1000 psi a preferred upper value. Process economics favor lower operating pressure, however, a moderately elevated reaction pressure may be desirable to keep gaseous reaction components, if any, in solution.
The amount of CoA 3 present compared to the NBD feed should be catalytically sufficient to obtain the desired product. Generally the mole ratio of NBD to CoA 3 can range between from about 50 to about 2000 with a preferred range between from about 100 to about 1000.
The second component of the catalyst system is TPP. The amount of this second component of the catalyst system should be catalytically sufficient to obtain the desired product. Generally the mole ratio of TPP to CoA 3 can range between from about 0.55 to about 100 with a preferred range between from about 1 to about 5.
DEAC, EADC, or EASC is the third component of the catalyst system with DEAC preferred. The amount of the third component can vary substantially but generally it relates to the amount of CoA 3 used. An effective mole ratio of DEAC, EADC or EASC to CoA 3 can be between from about 0.5 to about 100 with from about 1 to about 50 preferred and from about 3 to about 20 more preferred. Excess DEAC, EADC or EASC also serves as a scavenger for any water and/or oxygen in the system. Generally, however, when DEAC, EADC or EASC is used it is advantageous to conduct the reaction under substantially anhydrous conditions and under an inert gas blanket.
The feed to the process consists essentially of NBD. Other hydrocarbons, which could react with the NBD or with itself, should be avoided since such hydrocarbon could lower yields, and/or the effectiveness of the catalystic system.
The selective NBD dimerization of the present invention can be carried out in either a batch or a continuous process.
To further illustrate the invention, the following examples and comparisons are provided.
EXAMPLES
The accompanying Table summarizes the dimerization and comparative runs which were carried out in 15 milliliter pyrex vessels closed with wired serum caps fitted with an internal immersion thermometer. The procedure was as follows. In comparative run 1 the CoA 3 , TPP and NBD were added to the vessel. The resulting mixtures was deaerated by flushing with argon. After the deaeration the mixture was cooled from a temperature of about 24° C. to -60° C. The cooling was for safety reasons; initially it was thought that the resulting exotherm would be extremely rapid. Then DEAC, in a 1 molar solution with toluene, was added. The DEAC solution was at room temperature so the temperature of the resulting mixture increased above the aforementioned -60° C. The resulting mixture was warmed to room temperature and then the temperature of the combination of DEAC, NBD, TPP and CoA 3 gradually increased by itself and reached a maximum of 55° C. During the warming the color of the mixture of CoA 3 , TPP and NBD changed from an initial green solution to brown with the assimilation of DEAC and gradually then changed to amber. And then during the final warming period, a precipitate formed. As shown in the Table, little or no conversion occurred after 74 minutes.
Run 2 was essentially a repeat of Run 1 except that the amount of TPP used was increased. As shown in the Table, after 42 minutes the conversion was 29% and the selectivity as to Binor-S was in excess of 90%.
Run 3 also was essentially a repeat of Run 1 except that the amount of TPP used was increased compared to Runs 1 or 2. As shown in the Table both the conversion and selectivity were excellent.
Run 4 was different (from Runs 1-3) in that an ether (CH 3 CH 2 0--CH 2 CH 3 ) was used as a solvent and that the mixture of CoA 3 , TPP, NBD and the ether was cooled from about 24° C. to 0° C. Then the DEAC was added and the mixture warmed. As shown in the Table both the conversion and selectivity were in excess of 95%.
Run 5 was different from the previous runs in that the mixture of CoA 3 , TPP and NBD, after deaeration of 24° C., was warmed to 65° C. to insure that all the components were in solution. Afterwards, the mixture was cooled to -20° C. After cooling, the DEAC was added. However, upon adding the DEAC, a rapid exotherm and evolution of gas (about 5 minutes) caused the resulting mixture to boil. For safety reasons after 22 minutes the reaction vessel was quenched in a -65° C. bath. The conversion was 73.4% whereas the selectivity was 95.3%.
While in Run 5 the initial color of the solution was green, as in all runs, it turned yellow with the addition of the DEAC and then turned to a hazy amber.
Run 6 was made using cyclopentadiene as a solvent. The CoA 3 , TPP and NBD were mixed, deaerated, and then warmed to 60° C. to insure that all the components were in solution. Then the mixture was cooled to -29° C. At the lower temperature the DEAC was added, and the mixture was warmed. The cyclopentadiene was then added and again the mixture was warmed. The addition of the latter caused an orange colored precipitate. As shown in the Table, after 90 minutes the conversion was 32% and the selectivity was 73%, excluding the precipitate.
Comparisons of Runs 1 and b 2 indicate that a catalytic amount of the three component system need be present to obtain Binor-S. Comparison of Runs 2 and 3 indicate that the use of additional TPP increases the conversion and reaction rate. Runs 4 and 6 indicate that solvents can be used.
Analogous results will be obtained when other solvents, e.g., benzene, toluene, xylene, cyclohexane, chlorobenzene, bromobenzene, chlorinated cyclohexane are used and/or EADC or EASC is used in lieu of DEAC.
TABLE__________________________________________________________________________DIMERIZATION OF NBD TO FORM BINOR-S AdditionalAmounts of.sup.5 Time.sup.3 Maxmum Solvent.sup.6 % NBD % Binor-SRun NBD CoA.sub.3.sup.2 TPP.sup.2 DEAC.sup.7 (minutes) Temp. °C. (Amount) Conversion.sup.1 Selectivity.sup.1__________________________________________________________________________1 1 ml 7.5 mg 3 mg.sup.4 0.4 ml 74 55 none nil n.a.2 1 ml 7.5 mg 7 mg " 42 55 none 29 903 1 ml 7.5 mg 20 mg " 10 55.sup.9 none 96 904 0.9 ml 7 mg 4 mg " overnight 50 ether (0.9 ml) 95 955 1 ml 7 mg 21 mg 8 22 92 none 73.4 95.36 1 ml 7 mg 14 mg 0.4 ml 90 80 cyclopentadiene 32 73 (0.4 ml)__________________________________________________________________________ .sup.1 Based on analysis via gas chromatography. .sup.2 The weights shown are approximate. .sup.3 Time is from addition of DEAC to the sample. .sup.4 TPP/CoA.sub.3 mole ratio = .543. .sup.5 ml = milliliters, mg = milligrams. .sup.6 Other than toluene. .sup.7 One molar in toluene. .sup.8 10 weight % DEAC in toluene. .sup.9 Exotherm to 92° C. may have occurred.
|
Binor-S is prepared by the catalytic dimerization of norbornadiene (bicyclo[2.2.1]hepta-2,5-diene) using a homogeneous catalyst system of cobaltic acetylacetonate and diethylaluminum chloride and triphenyl phosphine. Ethylaluminum dichloride or aluminum ethylsesquichloride can be used in lieu of the diethylaluminum chloride. The reaction rate is rapid at an ambient temperature. Binor-S can be used as a precursor for hydrocarbons having utility as a high energy fuel.
| 2
|
This application is a continuation, of application Ser. No. 198,200, filed May 25, 1988 now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a two-cycle engine and, more particularly, to a two-cycle engine employing a balancing shaft and wherein an engine casing is provided in which an intake passage, a crank chamber and a transmission chamber are integrally formed.
A large number of two-cycle engines carried by vehicles, such as motorcycles, motor three wheelers, or the like, are provided with an engine casing in which an intake passage, a crank chamber and a transmission chamber are integrally formed. Such engines are also provided with a balancer shaft which is used for cancelling oscillations due to the reciprocatory movements of the pistons, the connecting rod, or the like. In such two-cycle engines, as for example the one disclosed in Japanese Patent Laid-Open No. 62-13761 (No. 13761/1987), both of the intake passage and the balancer shaft are arranged above the line which connects the axis of the crank shaft with the axis of the main shaft of the transmission mechanism in which the power of the crank shaft is input to the axis of the main shaft. Consequently, the conventional structure of these engines is not intended to lower the center of gravity of the engine. Also, in such engines incorporating a structure wherein reed valve is located in the intake passage, because of the problem of balancer shaft interference with the reed valve, limitations are imposed when designing the reed valve.
SUMMARY OF THE INVENTION
The present invention is devised in light of the aforementioned circumstances and, accordingly, has as an object to provide a two-cycle engine in which the center of gravity of the engine can be lowered, without impeding the layout, or accommodation of the reed valve.
In order to attain such object, there is provided, according to the present invention, an intake passage arranged in the engine casing above the line connecting the axis of the crank shaft with the axis of the main shaft, while the balancer shaft is arranged below this line.
Practice of the present invention results in a lowering of the center of gravity of the engine and facilitates the layout of the reed valve.
For a better understanding of the invention, its operating advantages and the specific objectives obtained by its use, reference should be made to the accompanying drawings and description which relate to the preferred embodiments thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional elevational view illustrating essential parts of the engine casing of the present invention;
FIGS. 2 and 3 are sectional views taken along line II--II and III--III, respectively, in FIG. 1; and
FIG. 4 is a view similar to FIG. 2 illustrating a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drawing figures illustrate at 1 a two-cycle engine, at 3 a crank shaft, at 5 a cylinder axis, at 7 a cylinder, at 9 an intake passage, at 11 a reed valve, at 13 an exhaust passage and at 15 an engine casing. The engine casing 15 (FIG. 2) comprises a casing body 17, and side covers 19 and 21 which are attached to the left and right sides, respectively, of the casing body 17. A crank chamber 23 is defined in the front portion of the engine casing 15 and a transmission chamber 25 is defined in the rear portion of the crank chamber 23. Also, a side chamber 27 is defined by a left side cover 19 and the left side wall of the casing body 17, and a balancer chamber 29 is defined by a right side cover 21 and the right side wall of the casing body 17. Lubricant oil is stored in the transmission chamber 25, the side chamber 27 and the balancer chamber 29.
In the chamber 25 is arranged a transmission mechanism 33 that is provided with a main shaft 37 on which are mounted a plurality of reduction gears 35 and a counter shaft 39. Power generated by the crank shaft 3 is input to the main shaft 37 through the intermediary of a clutch 41 arranged in the side chamber 27. The intake passage 9 is formed in the upper portion of the engine casing above a phantom line 49 which connects the axis of the crank shaft 3 with the axis of the main shaft 37. Reference numeral 43 indicates a balancer shaft which is rotatably supported by bearings 45 and 47 incorporated into the casing body 17. The balancer shaft 43 is arranged below the phantom line 49. To the left end of the balancer shaft 43 is attached a driven gear 51 with the drive gear 53 of the crank shaft 3 in the side chamber 27 which serves as a balancer 55A. To the right end of the balancer shaft 43 is provided a balancer 55B which is contained in the balancer chamber 29.
In the portion of the side chamber 27, where the drive gear 53 and the driven gear 51 mesh with each other, is formed a pressure chamber 57 in which the lubricant oil is collected by the toothed portions of the gears 51 and 53 and the pressure thereof increased. The pressure chamber 57 is defined by a side wall portion 19A and a bottom wall portion 19B of the left side cover 19, and a side wall portion 17A and a bottom wall portion 17B of the casing body 17.
Reference numeral 59 indicates an oil passage that communicates the transmission chamber 25 with the pressure chamber 57. Passage 59 is provided with a longitudinal portion 61 which extends substantially vertically and a portion 63 extending in the transverse direction. The longitudinal portion 61 of the oil passage 59 comprises a groove 65 formed in the casing body 17 and a plate-like piece 69 attached to the casing body by a threaded screw 67 to cover the groove 65. The transverse portion 63 of the passage 59 contains appropriately positioned holes 71 for supplying oil to the parts to be lubricated.
An opening 73 is provided in the cover piece 69 to communicate pressure chamber 57 with the lower end of the longitudinal portion 61. An oil passage 75 communicates the bottom portion of the transmission chamber 25 with the bottom portion of the side chamber 27. Also, the bottom portion of the balancer chamber 29 is adapted to communicate with the bottom portion of the side chamber 27 through the opening at 77 disposed adjacent the driven gear 51.
The present embodiment, constructed as described above, advantageously lowers the center of gravity of the engine, and in the disposition of the reed valve 11, the latter suffers no restriction from the balancer shaft 43 thereby enhancing the layout of the reed valve 11.
As a result of the described arrangement, during operation of the engine, the lubricant oil collected in the side chamber 27 is supplied under pressure from the pressure chamber 57 to the reduction gears 35 in the transmission chamber 25 through the intermediary of the opening 73, the oil passage 59 and the hole 71, whereby the lubrication of the transmission mechanism 33 is improved. Also, because the lubricant oil is supplied from the described pressure chamber to the transmission chamber 25, as shown in FIG. 2, the oil level in the transmission chamber 25 is increased while being lowered in the side chamber 27 and the balancer chamber 29. Therefore, according to the present invention, the efficiency of lubrication of the transmission mechanism 33 is increased. Moreover, it is possible to arrange the balancer shaft 3 at the lower position in order to lower the center of gravity of the engine while, at the same time, reducing the loss of power resulting from the stirring resistance of the balancer 55 in the body of lubricant oil.
Although the described embodiment is adapted to incorporate two balancers on the portion out of the web portion of the crank shaft 3 on the balancer shaft 43, one balancer may be provided at a position opposing to the web portion.
FIG. 4 illustrates a second embodiment of the present invention in which the balancer chamber 29 and the side chamber 27 are separated by a seal member 91 and lubricant oil is not stored within the balancer chamber 29. By means of this arrangement the stirring resistance of a balancer 55B in a body of lubricant oil is totally eliminated. This second embodiment of the invention otherwise has the same function and effect as the first embodiment; that is, it operates to lower the center of gravity of the engine 1 and is advantageous in the layout of the reed valve 11.
As is apparent from the above description, the present invention provides a two-cycle engine having the advantage of a lowered center of gravity and an improved layout of the reed valve.
It should be further understood that, although preferred embodiments of the invention have been illustrated and described herein, changes and modifications can be made in the described arrangements without departing from the scope of the appended claims.
|
A two-cycle engine having a crank shaft, a main transmission shaft and a balancer shaft in order to lower the center of gravity and to improve lead valve layout is provided with a casing structure containing an intake passage formed integrally with a crank chamber and a transmission chamber and wherein the intake passage is located in a portion of the casing above the axes of the crank shaft and the main shaft and the balancer shaft is located below such axes.
| 5
|
This application is a continuation of application Ser. No. 407,882, filed Aug. 13, 1982 now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a sheet assembly for simple and quick manual work of applying a polish or like composition to a desired object and polishing it. The object to be polished may be a shoe, a car or furniture, for example.
Sheets impregnated with polishing oil of known types are typically furnished with in hotel rooms or the like for free service for cleaning shoes. Such sheets, however, are not of the nature which positively give shoes their original gloss since the oil is not a shoe polish, though capable of achieving the cleaning function only.
A sheet assembly for polishing work embodying the present invention can carry a shoe polish in itself and, therefore, perform regular shoe polishing work in addition to the simple cleaning work. This allows shoes to be polished positively, easily and quickly.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a portable sheet assembly which can readily and quickly polish a desired object such as a shoe, a baseball glove or furniture or even avoid fogging of glass when applied thereto. In order to achieve this object, the sheet assembly of the present invention is provided with a portion for retaining an intended composition for polishing work, which may thus be a shoe polish or like polishing material, wax for preservation of hide, or antifogging material. Such sheet assemblies will prove desirable when installed in rooms for free service.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a sheet assembly for polishing work embodying the present invention;
FIG. 2 is a section taken along line II--II of FIG. 1;
FIG. 3 is a perspective view of another embodiment of the present invention;
FIGS. 4 and 5 are sections showing further different embodiments of the present invention;
FIG. 6 is a plan view of a still further embodiment of the present invention;
FIG. 7 is a perspective view of a still further embodiment of the present invention;
FIG. 8 is a section taken along line VIII--VIII of FIG. 7;
FIG. 9 is a perspective view of a still further embodiment of the present invention; and
FIGS. 10, 11, 12 and 13 are sections of still further embodiments of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Preferred embodiments of the present invention will be described hereunder with reference to the accompanying drawings.
Referring to FIGS. 1 and 2, a sheet assembly for polishing work embodying the present invention is shown and generally designated by the reference character A. The sheet assembly A includes a sheet 1 which may be a Japanese paper or a non-woven fabric having a surface and an interfilament spacing as rough as those of a Japanese paper. Said sheet 1 has a first side and a second side.
A sheet lamination 4 is bonded to the first side of the sheet 1 along its peripheral edge 4c by welder means or adhesive means, in such a manner that a dispersion space S is defined between the sheet lamination 4 and sheet 1 which form a first chamber. The sheet lamination 4 is made up of a non-permeable relatively thick and strong outer film 4a such as of plastic or aluminum material and a non-permeable relatively thin and weak inner film 4b such as of plastic material (preferably polyethylene), which define a sealed second chamber R therebetween. A composition 3 such as a polish is filled in the sealed chamber R. Both the outer and inner films 4a and 4b are made of transparent or translucent synthetic resin such as polyethylene. The sheet lamination 4 is formed with a plurality of apertures 4d at one of its diametrically opposite portions in order to allow the filler 3 to come out therethrough, as will be described later. The second side of the sheet 1 is coated with a thin layer 1a of polyvinyl chloride or like synthetic resin. Pockets 2 for receiving a user's fingers are formed on said second side of the sheet 1.
Referring to FIG. 3, a sheet assembly A' according to another embodiment of the present invention includes first and second non-woven fabric sheets 5 whose facing or inner surfaces are individually coated with layers 5a of synthetic resin. The sheets 5 are bonded together through the layers 5a by welder means along preselected opposite edges thereof as at 6. The rest of the sheets 5 spanning the bonded edges 6 forms a pocket or sack 7 into which fingers can be inserted.
One of the sheets 5 carries on a first side thereof the sheet lamination 4 for storing the filler which may be a shoe polish 8 in this embodiment, though the manner of storage of the filler is identical with that of the first embodiment. The position of the sheet lamination 4 is such that it will be backed through sheet 5 by fingers which are inserted into the pocket 7.
In use, the sealed chamber R of the sheet lamination 4 is strongly pressed from behind by fingers to rupture the inner film 4b. Then, the filler 3 or 8 is discharged from the chamber R into the dispersion space S and, therefrom, to the outside of the sheet assembly via the apertures 4d by further pressing action of the fingers. The filler 3 or 8 on the sheet 1 or 5 is now ready to be applied to a desired object such as shoes.
FIG. 4 shows a further embodiment of the present invention in which a retainer sheet 9 defines the sealed chamber R for storing the filler. The sheet lamination 4 composed of sheet 4a and polyethylene film 4b is laid on the retainer sheet 9 and bonded together therewith to the sheet 1 along aligned edges 4c and 9a of the sheet lamination 4 and sheet 9.
FIG. 5 illustrates a still further embodiment of the present invention which employs a capsule 10 for defining the sealed chamber R. The capsule 10 is movably disposed in the space S which is defined between the non-woven fabric sheet 1 and sheet lamination 4. Said capsule 10 is made of polyethylene film.
FIG. 6 shows a still further embodiment of the present invention which is designed to facilitate discharge of the filler to the outside of the sheet assembly. The sheet lamination 4 in FIG. 6 is bonded to the sheet 1 throughout its major area except for the sealed chamber R and the space S which is directed to the apertures 4d.
Referring to FIGS. 7 and 8, a still further embodiment will be described hereinafter. The first side of the sheet 1 is coated with a thin layer 1a of polyvinyl chloride or like synthetic resin. Pockets 2 for receiving fingers are formed on the same side of the sheet 1 which has the layer 1a thereon. The sheet 1 carries a sheet lamination on its first side which has the layer 1a. The sheet lamination 4 comprises a non-permeable relatively thick and strong film 4a such as a film of transparent or translucent synthetic resin typified by polyethylene or a foil of metal typified by aluminum. A non-permeable film 4b of synthetic resin is positioned inside the sheet 4a to define a sealed second chamber R in cooperation with the latter. The film 4b is shaped to be relatively thin and weak. A composition 3, which may be a polish for example, is filled in the sealed second chamber R. The sheet lamination 4 is bonded to the sheet 1 along its peripheral edge 4c by welder means or adhesive means, while defining a dispersion space S therebetween forming a first chamber. The sheet 1 is formed with a plurality of apertures 1b in its area which corresponds to the dispersion space S. The filler 3 will come out through the apertures 1b when the sheet assembly is in use, as will be described later.
Referring to FIG. 9, a sheet assembly A' according to a still further embodiment includes first and second nonwoven fabric sheet 5 whose facing or inner sides are individually coated with layers 5a of synthetic resin. The sheets 5 are bonded together through the layers 5a by welder means along preselected opposite edges thereof as at 6. The rest of the sheets 5 spanning the bonded edges 6 forms a pocket or sack 7 into which fingers can be inserted. One of the sheets 5 carries on its first side the sheet lamination 4 for storing the filler 8 which may be a shoe polish 8 in this embodiment, though the manner of storage of the filler is identical with that of the previous embodiment. The position of the sheet lamination 4 is such that it will be covered by fingers when the fingers are inserted into the pocket 7. This sheet 5 is formed with apertures 5b in its area which corresponds to the space S, in order to allow the passage of the filler 8 to the outside of the sheet assembly.
In use, the sealed chamber R of the sheet lamination 4 is strongly pressed from behind by fingers to rupture the inner film 4a. Then, the filler 3 or 8 is dislodged from the chamber R into the space S and, therefrom, to the second side of the sheet 1 or 5 via the apertures 1b or 5b. The filler 3 or 8 on the sheet 1 or 5 is now ready to be applied to a desired object such as shoes.
If desired, the apertures serving as outlets for the filler may be replaced by cuts or the like.
FIG. 10 shows a still further embodiment of the present invention in which a retainer sheet 9 defines the sealed chamber R for storing the filler. The sheet lamination 4 is laid on the retainer sheet 9 and bonded together therewith to the sheet 1 along aligned edges 4c and 9a of the sheets 4 and 9.
FIG. 11 illustrates a still further embodiment of the present invention which employs a polyethylene capsule 10 for defining the sealed chamber R. The capsule 10 is movably disposed in the space S which is defined between the sheets 1 and 4.
FIG. 12 shows a still further embodiment of the present invention wherein use is made of a sheet 1' constituted by a piece of non-woven fabric having a relatively rough filament structure, which permits the filler 8 to easily infiltrate thereinto. In this structure, a portion 1'b of the sheet 1 which overlies the space S serves as an outlet for the filler 3. The filler 3 will progressively ooze out through the sheet portion 1'b as the sheet assembly is rubbed against an intended object.
FIG. 13 shows a still further embodiment of the present invention which includes a layer of synthetic resin 1'a coated on the first side of a sheet 1', in addition to the structural elements shown in FIG. 12. The layer 1'a is formed with an opening 1'a 1 in its outlet portion 1'b.
Although the second chamber R sealing a polishing composition therein is adapted to be pressed by a user's fingers in the foregoing embodiments, a length of string may be attached to the relatively thin polyethylene film defining the chamber R to extend outside the sheet assembly such that the thin polyethylene film is broken by pulling the string from outside the sheet assembly.
In summary, it will be seen that a sheet assembly for polishing work of the present invention is portable and convenient for storage and can be used easily and quickly for various purposes such as shining shoes or keeping glass from a cloud.
It will also be seen that the sheet assembly prevents degeneration of a shoe polish or like composition over a long period of time, because the composition is retained in a sealed second chamber inside a first chamber.
|
A sheet assembly for polishing work is provided. A non-woven fabric sheet and a non-permeable thick sheet are bonded together to define a first chamber. Further, a second chamber to contain a shoe polish therein is defined within said first chamber by a non-permeable but easily rupturable film such as a polyethylene sheet. The non-woven fabric sheet or the non-permeable thick sheet is formed with apertures therein. The shoe polish contained in the second chamber is discharged therefrom and further through the apertures to the outside of the sheet assembly when manually pressed from outside such that the shoe polish is ready for application onto shoes such that the shoes are shined by use of the non-woven fabric portion.
| 0
|
BACKGROUND OF THE INVENTION
The present invention relates generally to the field of digital computers and, more particularly, to the field of executive function implementations.
An executive currently is defined as a program which regulates when each portion of the application software has access to the various resources of the computer. The application software informs the executive of its needs and available resources by calling executive service request (ESR) routines. Often several ESR's share common subroutine components. The one or more subroutine components of an ESR are called executive functions.
Executive functions are usually implemented in software. Occasionally, firmware implementations are used for speed improvement. While statistics in the literature vary, firmware implementations usually obtain a two to three times improvement in executive function execution speed. Their speed improvement is derived primarily through the elimination of most of the instruction fetches associated with software implementations. Executive functions make heavy use of data structures stored in memory. Consequently, the speed of the data access cycle is the major limiting factor preventing still further speed improvement through microprogramming.
The throughput of multiprocessing systems increases less than linearly with an increase in the number of processors. Each processor is burdened not only with the coordination of its own activity but also with at least some portion of the activity of the processors to which it is connected. Increasing the number of processors increases the overhead in each processor. Eventually, a point is reached where adding a processor has a negligible effect or even decreases the usable throughput of the system. This is because the increase in overhead in all the processors totals more than the capacity of the added processor.
One of the major manifestations of executive overhead is table searching. It is encountered in dispatch checking, real-time clock management, resource management, and event binding. To illustrate the effect, consider a multiprocessing system employing a common table. A configuration consisting of a single stand-alone processor spends some portion of its time serially searching a table. When a second processor is added to improve system capacity, both processors are required to search the same common table. The added contribution of processing from the second processor roughly doubles the original size of the table. Increasing the size of the table, and hence the time spent searching the table, leaves less time in each processor for other processing. The time each processor has available for other processing continues to decrease as additional processors are added.
Since table searching is an important component determining the speed of executive processing, executive software often exhibits similar characteristics. A good example is a common task table in a multiprocessing system in which the highest priority task ready for execution is dispatched on the first available processor. The dispatch check performed by each processor must examine all the tasks in the system. The larger the system, the more tasks each processor must examine, and consequently, the less application work performed by each processor.
Message processing in distributed processing systems also suffers from diminishing returns as processors are added. One example is SEAMOD, a proposed Navy distributed command and control system architecture. The processors of the system are interconnected through a high-speed message bus. It has been estimated in this proposed system that up to 58 percent more processors are required, depending on the configuration, simply to perform the executive functions associated with message traffic of the distributed system.
Another example of the problem is illustrated by an experiment performed by the developers of the Shipboard Integrated Processing and Display System (SHINPADS) for the Canadian Navy. They wished to demonstrate two megabits of data traffic on a triaxial cable bus interconnecting ten AN/UYK-20 computer emulators. Each computer generated and received one-tenth of the two megabit traffic. Using 200-bit messages, this means that each computer generated and received one message every millisecond. It was found that the one millisecond was consumed almost entirely by the executive software. Not only does such a system fail to apply the power of ten computers to the performance of the application work, but it fails to do almost any useful work.
The problem is that the execution speed of the executive functions is too slow in a conventional processor. The executive functions considered in the SEAMOD example, when executed on an AN/UYK-20 computer, would require 1.12 milliseconds per message. The motivation for high-speed execution of executive functions in hardware is the reduction of overhead in each processor of a multiprocessing or distributed processing system to extend the point of diminishing returns to a larger number of processors.
SUMMARY OF THE INVENTION
The computer hardware executive of the present invention overcomes the foregoing problem by implementing in hardware those executive functions which heretofore created particular execution speed bottlenecks in software executives. The hardware executive is not intended to replace a software executive in its entirety. A software executive can be built on top of the hardware executive which translates ESR's into either executive function calls on the hardware executive or on its own software as appropriate.
The computer hardware executive of the present invention is designed to be connected to the host processor through the memory interface of the host processor. The hardware executive appears to the host processor as a slow memory. The software of the host processor communicates with the computer hardware executive using a technique commonly know as "memory mapping." Each executive function is associated with a dedicated address in the address space of the hardware executive. In accordance with the present invention, the programmer invokes a hardware executive function by accessing the memory address associated with the desired function. The data read from or written to the dedicated executive function address is the operand of the executive function. The Task Dispatch Check executive function, for example, which determines the identity of the highest-priority task ready for execution, is performed by reading the identity of that task from the address dedicated to the Task Dispatch Check executive function.
The computer hardware executive of the present invention maintains internal executive tables. These tables are also mapped into the host processor address space. This enables them to be initialized by the host processor. They can be read or written like conventional memory. The host processor must not write into them indiscriminately, however, since their contents have a direct bearing on the proper operation of the algorithms implementing the executive functions.
The computer hardware executive of the present invention provides executive functions to control the allocation of space in its internal executive tables. The host processor requests space for a new table entry by executing the Reserve executive function for the table desired. There is one Reserve executive function for each table. The Reserve executive function is executed by reading the index of the table entry being assigned by the hardware executive from the address dedicated to that Reserve executive function. The index is then used by the host processor to form the addresses needed to directly load the table entry. This index can also be used to maintain parallel tables in software for items not handled by the hardware executive. The return of a negative index from the hardware executive indicates that the table is full. The host processor can easily detect a full condition using one of its conditional branch instruction.
The term "task" refers to an independent entity of computing. For example, a computer system permitting many users on different terminals access to the same central processor and other computer resources assigns a unique task to each user's computing since the computing of each user is generally unrelated to the computing of the other users. The term "task management" refers to the process of determining which task obtains access to which computer resource at any point in time.
Two of the hardware executive internal executive tables are used for task management. The first, the task table, contains a table entry for each task. It maintains information needed to determine which task should next gain control of the host processor. Its entries have three fields. The state field indicates whether the task is ready for execution. The priority field indicates the preference the task should have relative to other tasks when it is among several that are ready for execution. The semaphore field identifies the resource which is preventing a waiting task from being ready for execution. Resources are defined by the user. Examples of resources include peripheral devices and segments of programs and data stored in memory.
The other table, called the semaphore table, contains an entry for each resource claimed for exclusive use by a task. Its entries have two fields. The semaphore field identifies the resource claimed. The task field identifies the task making the claim. The semaphore table is used to determine if a resource is available and to identify all the resources claimed by a task that can be made available when a task is terminated.
A task is created in accordance with the present invention by establishing an entry for the task in the internal task table. The index of an empty task table location is obtained by reading the contents of the hardware executive address dedicated to the Reserve Task executive function. This index is used by the host processor to form the memory addresses necessary to directly load the appropriate task table fields for the new task. The return of a negative index indicates that the task table is full.
A task known to the executive is in one of five possible states at any given time, described as follows.
Running: In this state the task is executing on the host processor.
Ready: In this state the task could execute on the host processor.
Waiting: In this state the task cannot execute on the host processor until a resource it desires becomes available.
Suspended-Ready: In this state the task is explicitly prevented from executing on the host processor.
Suspended-Waiting: In this state the task is explicitly prevented from executing on the host processor, but even if this were not the case, it cannot execute on the host processor until a resource it desires becomes available.
The Reserve Task executive function initializes the task table entry to the suspended-ready task state to prevent its consideration for execution until the task table entry can be completely specified. The task state transitions resulting from the various executive functions in accordance with the present invention are depicted in FIG. 1.
The term "dispatching" refers to the process of determining which task should have control of the computer at a given point in time. The determination is based on the contents of the task table. There are many algorithms which may be used to decide which task to dispatch. The Dispatch Check executive function of the present invention selects for dispatch the task having the highest priority from among the tasks in the ready or running task state. The priority is a number supplied by the user which indicates the relative importance of executing the associated task before other tasks when a choice is possible. If two or more tasks of the same priority are in the ready or running task state, they are queued on a first-ready-first-dispatched basis.
The Dispatch Check executive function of the present invention returns to the host processor the task table index, which also serves as the task identifier, of the task that next enters the running task state. The host processor then uses the index to direct the task-to-task context switch. The Dispatch Check executive function returns a negative number to the host processor when no task can be placed in the running task state. The negative condition can be used to direct the host processor to its idle loop.
The Wait-On-Semaphore executive function is used to move a task from the ready or running task states to the waiting task state if a desired resource is not available. For example, a user may desire that only one task at a time have access to a printer. All tasks invoke the Wait-On-Semaphore executive function to determine whether the resource, in this case a printer, is available before attempting access. Resources are identified by a unique user-defined number called a "semaphore". Availability of a resource is indicated by the absence of its semaphore from the internal semaphore table.
The Wait-On-Semaphore executive function first checks the semaphore table to determine whether any other task has previously claimed the resource associated with the semaphore. If the semaphore is found in the table, then the resource is not available. In this case, the state field of the task table entry is changed to move the task from the running state to the waiting state and the semaphore field is loaded with the semaphore on which the task is waiting. If, on the other hand, the semaphore is not found in the semaphore table, then the associated resource is available. The invoking task can remain in the running task state. The Wait-On-Semaphore executive function claims ownership of the resource on behalf of the invoking task by recording the semaphore and task identifiers in an empty location in the semaphore table.
Since the Wait-On-Semaphore executive function has the potential of creating a new entry in the semaphore table, the function must be preceded by a Reserve Semaphore executive function to assure the availability of space. This space is freed by the Wait-On-Semaphore executive function if it turns out not to be needed.
The Signal Semaphore executive function is used to announce that a resource is now available. It searches the task table for the highest priority task waiting on the semaphore specified by the function operand. Once found, the task is moved from the waiting (or suspended-waiting) task state to the ready (or suspended-ready) task state and its semaphore field in the task table is cleared. Finally, the task identifier is loaded into the semaphore table entry associated with the signaled semaphore to claim ownership for the task.
The Suspend Task executive function is used to explicitly exclude the specified task from consideration by the Dispatch Check executive function. If the task is in the ready or running task states, it is moved to the suspended-ready task state. If the task is in the waiting task state, it is moved to the suspended-waiting task state.
The Resume Task executive function is the converse of the Suspend Task executive function. If the task is in the suspended-ready task state, it is moved to the ready task state. If the task is in the suspended-waiting task state, it is moved to the waiting task state.
A task is terminated by first invoking the Suspend Task executive function to properly exclude the task from further dispatch. Then the Terminate Task executive function is invoked. The latter function flags all the semaphores in the semaphore table owned by the specified task. It is followed by repeated invocations of the Release Semaphore executive function. The Release Semaphore executive function returns, one by one, the identity of the semaphores owned by the task being terminated. The host processor uses this information to release the resources owned by the terminated task using the Signal Semaphore executive function. Finally, the content of the task table entry is cleared by direct accesses to the task table address space.
The Wait-On-Semaphore, Signal Semaphore, Suspend Task, and Resume Task executive functions all potentially or actually change the task state. They should by followed by the Dispatch Check executive function since the task previously in the running state may not be ready or have the highest priority.
The term "event" refers to a software or hardware perturbation causing an alteration in the expected sequence of computing. The event concept can be viewed as a generalization of the hardware interrupt concept to include pseudo-interrupts triggered by software.
The computer hardware executive of the present invention distinguishes between normal events and time events. The term "normal event" refers to an event triggered only directly through software invocation of the Cause Event executive function. The term "time event" refers to an event triggered by the expiration of a present time interval as well as by the Cause Event executive function. Time events are either time-critical or non-time-critical. The term "time-critical" refers to a time event which has been specified by the user to demand immediate notification of the hose processor when it occurs. The term "non-time-critical" refers, on the other hand, to a time event that can be checked for occurrence at the convenience of the host processor.
An executive cannot respond to an event unless it has been instructed previously as to what action should be taken when the event occurs. The term "event registration" refers to the process of associating an event or a class of events with a task to be created or a semaphore to be signalled.
The computer hardware executive of the present invention maintains a list of event registrations in its internal event tables. Normal and time event registrations are maintained in separate tables to enlarge the maximum number of events permitted. Normal event table entries contain two fields. The event field contains user-defined information specifying the event or class of events to which the registration applies. The state field whether the event has been triggered. Time event table entries contain the same two fields found in normal event table entries plus two additional fields indicating the time interval remaining before the event is triggered and whether the time event is time critical.
An event is registered by first obtaining an empty event table entry location using either the Reserve Normal Event executive function or the Reserve Time Event executive function depending on the type of event. The functions return to the host processor the event table index of an empty location. The functions mark the selected entry location as reserved but as yet not registered to prevent the entry from being considered by other event executive functions until the appropriate fields of the entry are completely specified. The specification of user-specified fields is performed by direct accesses into the event table entry. Return of a negative index by the functions indicates that the respective table is full.
An event known to the executive has two possible states at any given time.
Armed: This state indicates that the executive is ready to process the event if something causes it to occur.
Triggered: This state indicates that the executive has recognized that the event has occurred.
The event state transitions are illustrated in FIG. 2.
The Cause Event executive function matches the event specified by the function operand with a qualifying event registration in the normal or time event tables. The event table entry selected is then moved from the armed to the triggered event state. The Cause Event function should be followed by the Normal Event Check and the Time Event Check executive function. These functions return the event table index of the highest priority event in the triggered event state and then move the selected event to the armed state. The host processor uses this index to identify the task to be created or the semaphore to be signalled. Return of a negative index indicates that no events in the respective event table remain in the triggered state. Since several time events may be triggered at the same time, the Time Event Check executive function should be repeated until all triggered time events are processed.
The initial time interval associated with a time event is relative to the time that the event was registered. An oscillator in the present invention generates "ticks" which are processed by the hardware executive microprogram. When a tick is detected, the contents of the time interval field of all the armed time event table entries are decremented and tested. Those found to contain zero are moved to the triggered state and their time-critical bit is tested. If the time-critical bit indicates a time-critical event, then an interrupt is generated to notify the host processor that a time-critical event has occurred. Periodic Time Event Check executive functions must be invoked to detect triggering of non-time-critical time events.
The registration of an event is removed using the Cancel Event executive function. This function frees the space occupied by the event table entry.
Most function performed by a software executive implementation consist of the manipulation of tables or linked lists. The implementation of these functions can be viewed as a state machine. In the state machine model, the ESR's are the input, the identity of the next running task is the output, and the content of the various internal tables or linked lists is the machine state. Executive functions are the component algorithms of ESR's used to transform the present state into the next state. This model is illustrated in FIG. 3.
The computer hardware executive of the present invention contains an associative memory for the storage of executive tables. The term "associative memory" refers to a memory which identifies any of its locations containing a value equivalent to a given input. Thus the associative memory of the present invention implements a table search in hardware. The associative memory of the computer hardware executive of the present inventions is designed to permit searches on any bit position or set of bit positions within its locations. This enables the same location to contain a single entry for each of the executive tables.
The associative memory of the present invention is implemented using conventional random access memory (RAM). The RAM is organized such that the same bit position of all associative memory locations is accessed simultaneously. One way to visualize this organization is to view the associative memory as a two-dimensional matrix of bits where rows correspond to words mapped into the host processor address space and columns correspond to words of physical RAM. When the host processor writes directly into the tables, the microprogram of the hardware executive of the present invention serially loads the word from the host processor one bit at a time into the successive physical RAM addresses. Similarly, when the host processor reads directly from the tables, the operand read is collected serially from successive physical RAM addresses. This approach to implementing an associative memory is termed a "bit-serial" associative memory implementation.
Each associative memory location of the present invention has a serial adder/subtracter and a capture flip-flop. The microprogram of the present invention performs searches one bit position per cycle across all associative memory locations simultaneously. Each serial adder/subtracter compares the sought contents with the contents of it respective location. The capture flip-flop, which is cleared at search initialization, is set by the serial adder/subtracter when a bit position fails to match. All capture flip-flops still remaining cleared after all the bit positions of interest have been examined correspond to the locations satisfying the search criterion. A priority encoder connected to the output of the capture flip-flops identifies the location with the lowest location address from among those satisfying the search criterion. It is used when only a single location satisfying the search criterion is desired, such as when a table index is returned to the host processor.
Searching for the location whose given field contains numerically the lowest value follows a similar process. The search proceeds from the most-significant to the least-significant bit position of interest. Special circuitry in the present invention is enabled which prevents any of the capture flip-flops from being set by a microinstruction cycle if so doing would leave all capture flip-flops set. The Dispatch Check executive function uses this type of search to find the highest priority task for the running task state. High priority is represented by a low positive numeric value.
Queues within user priority levels are implemented by extending the user priority field with a queue priority field consisting of bits of lesser numeric significance. Tasks entering the queue receive progressively lower queue priority assignments. Tasks leaving the queue cause the queue priority of all the tasks of lower queue priority to be adjusted upward. The adjustment is efficiently handled by the serial adder/subtracters. This technique prevents overflow of the queue priority field.
The computer hardware executive of the present invention performs internal table searches by sequentially examining each bit position of all table entries simultaneously. The search time depends on the number of bits in the table fields and not on the number of entries in the table. Faster execution is obtained because the number of bit positions examined is usually smaller than the number of table entries. This simplifies system design by removing the variability in execution speed of the executive functions.
The hardware executive of the present invention reduces context switching. The term "context switching" refers to a form of overhead encountered when resources occupied by one program, typically the processor and memory management registers, are transferred to another program. One source of context switching is the transfer from the application software to the executive software and back again. Hardware implementation of the executive reduces context switching by providing separate resources for the executive which are independent of those used by the application software. Another source of context switching results from the requirement for re-entrant executive functions. An executive function is made re-entrant to permit its preemption by an interrupt handler desiring use of the same executive function. Executive functions of the computer hardware executive of the present invention have been specifically designed such that an interrupt between a sequence of executive functions does not disrupt their proper operation.
The computer hardware executive of the present invention is connected to the host processor in the same manner as a conventional memory. Executive functions are selected by accessing the appropriate address within the hardware executive address space. This "memory mapped" interface permits simple retrofit of the hardware executive to existing computers since there is no need to augment or modify the host computer instruction set. The same basic hardware executive unit can be attached to a large variety of different processor designs while only the memory interface logic changes from design to design. The memory mapped interface also provides the ability to share a common hardware executive among several processors. Like shared memory, the hardware executive address space is configured to be accessible to each processor.
OBJECTS OF THE INVENTION
Accordingly, it is the primary object of the present invention to disclose a special-purpose associative processor for providing high-speed execution of computer executive functions.
It is a concomitant object of the present invention to disclose a machine for implementing computer executive functions which eliminate most context switching between the application processing and the executive and between the executive and itself.
It is another object of the present invention to disclose a mechanism for performing computer executive functions which utilizes an associative memory to thereby achieve high-speed execution.
A further object of the present invention is to disclose a mechanism for implementing computer executive functions by examining a single bit position of all table entries simultaneously whereby the search time is the same regardless of the number of active table entries.
Still another object of the present invention is to disclose a computer executive function implementing mechanism for use with a host computer which requires no augmentation or modification of the host computer instruction set thereby enabling retrofit of the computer hardware executive of the present invention to existing computers.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a task state transition diagram previously referred to in the Summary of Invention.
FIG. 2 is an event state transition diagram previously referred to in the Summary of Invention.
FIG. 3 is a block diagram of the computer executive implementation modeled as a state machine previously described in the Summary of Invention.
FIG. 4 is a block diagram of the computer hardware executive of the present invention showing its interconnection with the host processor.
FIG. 5 is a block diagram of one of the associative memory logic banks of the present invention.
FIG. 6 is a schematic block diagram illustrating how the associated memory logic banks of the present invention are interconnected to each other and to the various busses utilized in the present invention.
FIG. 7 is a block diagram of the data multiplexer utilized in each associative memory logic bank of the present invention, illustrating the connection of the EMIT bit to the data multiplexer.
FIG. 8 is a block diagram of the memory selection logic portion of the present invention.
FIG. 9 is a block diagram of the microsequence control logic portion of the present invention.
FIG. 10 is a block diagram of the bank and bit priority logic components of the present invention.
FIG. 11 is a block diagram of the register logic portion of the present invention.
FIG. 12 is a block diagram conceptual representation of the capture enable logic portion of the present invention.
FIG. 13 is a block diagram of the capture enable logic of the present invention.
FIG. 14 is a block diagram of the memory address register logic portion of the present invention.
FIG. 15 is a block diagram of the register clock decoder portion of the microinstruction decode logic portion of the present invention.
FIG. 16 is a block diagram of the transform logic portion of the present invention.
FIG. 17 is a network block diagram of one of the random access memories of the present invention.
FIG. 18a is a block diagram of another portion of the microinstruction decode logic of the present invention.
FIG. 18b is a block diagram of a still further portion of the microinstruction decode logic of the present invention.
FIG. 19 is a block diagram of the priority register of the present invention.
FIG. 20 is a block diagram of the host bus interface control logic of the present invention.
FIG. 21 is a block diagram of the pulse detect circuit portion of a the host bus interface control logic of the present invention.
FIG. 22 is a host bus interface control logic timing diagram example.
FIG. 23 is a block diagram of the ALLCAP register and gate of the present invention.
FIG. 24 is a block diagram of the interface of the host memory address bus to the command register of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENT
The design of the computer hardware executive of the present invention is functionally divided into four parts: The associative memory logic section, the memory selection logic section, the register logic section, and finally, the microsequence control logic section. The computer hardware executive 10 of the present invention is shown in FIG. 4 as it is connected to the host computer 12. The host processor 14 of the host computer 12 is connected to its host memory section 16 via the memory bus 18. The computer hardware executive 10 of the present invention connects directly to the memory bus 18 of the host computer 12.
The associative memory logic portion of the present invention is used to implement the storage and search of executive tables. A block diagram of the associative memory logic banks 20(n) of the present invention is illustrated in FIG. 5. In the preferred embodiment there are eight associative memory logic banks identical to the one depicted in FIG. 5. It is understood at this point that, although the preferred embodiment of the present invention utilizes eight banks of associative memory, a fewer or greater number of such banks may be utilized in accordance with the particular requirements of the application to which the invention is applied. Each of the associative memory logic banks 20(0), 20(1), . . . 20(N- 1) are interconnected by the system of busses as illustrated in FIG. 6. More particularly, each associative memory logic bank 20(n) is connected to the input BI bus 22, to the EMIT bus 24, to the capture enable EE bus 26, to the general enable AS bus 28, to the anticipated all capture gate AACG bus 30, to the output BO bus 32, and finally to the address A bus 33.
Part of each associative memory logic bank 20(n) is a random access memory RAM 34. The RAM 34 is constructed to provide independent read/write control of each bit position of the addressed word. This is accomplished by using a separate memory component for each bit position. It is noted that each bit position has an independent data input, DI, data output, DO, write enable, WE, and general enable, E. All of the bits of the addressed word share the same address input A and common general enable AS. The write enable, WE, and both general enables, E and AS, must all be in the logic true state for data to be written. The write enable must be in the logic false state and both general enables must be in the logic true state for data to be read. When these conditions are not met, the data output, DO, is in the logic one state.
The associative memory logic banks 20(n) are associative memories, and more particularly, bit-serial associative memories having the capacity to read from and write to internal locations like conventional memory, to search for the locations having a particular content in a particular location field, and to search for the locations with the minimum positive numeric value. A bit-serial associative memory is an associative memory constructed such that it accesses a single bit position of all locations simultaneously and performs its functions by sequencing through the bit positions serially. The bit-serial associative memory of the present invention is controlled by a microprogram.
Each of the RAM 34 data outputs, DO, provides a data path for reading the content of the bit position selected by the RAM address input, A, for a particular associative memory location. Each of the RAM 34 data outputs, DO, is connected to one input of an independent serial adder/subtracter 36. The other input of these serial adder/subtracters 36 is connected to the common signal referred to previously as the EMIT bit. Each serial adder/subtracter 36 contains an output flip-flop for synchronization of the output with the system clock.
Each RAM 34 data input, DI, is connected to the output of an independent output of a data multiplexer 38. The data multiplexer 38 selects for all associative memory locations simultaneously either the output of the respective serial adder/subtracter 36 or the common EMIT bit.
The general enable E of the RAM 34 associated with each associative memory location is connected to the output of an independent flip-flop called a capture flip-flop 40. When the common general enable AS is true, the presence of logic zero and logic one in the capture flip-flop 40 enables and disables the associated memory location, respectively. When an associative memory location is disabled, attempts to read to or write from the associative memory location are ignored and the data output, DO, is in the logic one state regardless of the location bit position content. The capture flip-flops 40 are clocked whenever the common capture flip-flop enable input, EE, is true.
The data inputs of the capture flip-flops 40 are connected to the output of another multiplexer 42. This multiplexer 42 selects for all capture flip-flops 40 simultaneously either the output of the serial adder/subtracter 36 logical OR'ed with the previous output of the capture flip-flops 40 via the OR gate 44 for each respective associative memory location, an independent input BI bus for the respective associative memory location within the associative memory bank, or zero. The first of these selections permits the occurrence of a logic one generated by the respective serial adder/subtracter 36 to be "captured", that is, to remain in the capture flip-flop for successively cycles. The other two multiplexer 42 selections are used to initialize the capture flip-flops 40.
The outputs of the OR gates 44 are connected to an AND gate called the anticipated all capture gate 46, AACG. The output of the anticipated all capture gate 46 is in the logic true state if and only if the output of each capture flip-flop 40 OR'ed with the output of respective serial adder/subtracter is a logic one for all associative memory locations of the associative memory logic bank 20(n).
The outputs of the capture flip-flops 40 are connected to respective bus buffers 48 permitting their output to be logically connected or disconnected to the output BO bus 32. This connection or disconnection is controlled by the buffer enable, BE. The output BO bus 32 is comprised of independent signals for each respective associative memory location of an associative memory logic bank 20(n). In the preferred embodiment, the bus buffers 48 are implemented from three-state buffer components. It is noted that the bus buffers 48 may be implemented with three-state buffers, open-collector buffers, open-emitter buffers, or multiplexers.
As shown in FIG. 6, the associative memory logic portion of the present invention is partitioned into N identical associative memory logic banks. Each associative memory logic bank 20(n) contains a segment of the total memory word addressed by the common address lines 33, A. As stated above, two busses, the input BI bus 22 and the output BO bus 32 interconnect the associative memory logic banks 20(n). The general enables AS inputs 28 and the anticipated all capture gate 46 AACG outputs for each associative memory logic bank 20(n) remain independent permitting the banks to be selected and examined individually.
As described previously, the associative memory locations of the computer hardware executive 10 are mapped into the host processor 14 address space. This enables the host processor 14 to load and to examine the content of the executive tables maintained by the computer hardware executive 10. The host processor 14 loads a segment of an associative memory location by writing into the address dedicated to that segment in the host processor address space. The host processor 14 provides the address of the segment and the contents to be loaded. Associative memory location segments are loaded serially, that is, each bit forming the segment is loaded on a separate microinstruction cycle. A bit position multiplexer, to be described, selects from among the various bit positions in the exchange register, to be described (see FIG. 11), the bit to be loaded on each microinstruction cycle into the memory component implementing the associative memory location.
The serial adder/subtracters 36 compare two serial bit streams, each pair of bits forming the bit streams being compared in a separate microinstruction cycle. More particularly, the number represented by the bit steam entering the serial adder/subtracter 36 from the respective data output DO of each RAM 34 memory component is compared with the number represented by the bit stream entering the respective serial adder/subtracter 36 from the EMIT input. The comparison is performed by subtracting one bit stream from the other, and if the resulting bit stream contains only logic zero bits, the two input bit streams are equal. The serial adder/subtracters 36 also have the capacity to increment or decrement a bit stream. This is accomplished by adding or subtracting a bit stream representing the number one via the EMIT input to or from the data output DO respectively.
In the preferred embodiment each associative memory logic bank 20(n) has eight associative memory locations. Since, in the preferred embodiment, there are eight associative memory logic banks 20(n), this gives a total of sixty-four associative memory locations in the preferred embodiment. Sixty-four associative memory locations in the preferred embodiment. It is to be understood, however, that other numbers of associative memory locations may be utilized upon the particular requirements of the application. The signals from the input BI bus 22 are used to initialize and load all enabled associative memory locations simultaneously. In this embodiment, therefore, there are eight wires from the input BI bus 22 leading from multiplexer 42, one wire for each associative memory location contained within a single associative memory logic bank. These wires are indicated by the notation on the line connecting the input BI bus 22 to the multiplexer 42 as is illustrated in FIG. 5.
The capture enable signal EE is a signal which enable or disables the clock of all the capture flip-flops 40. For example, if it is desired that the capture flip-flops not change their state regardless of what is coming from the multiplexer 42, turning off the enable EE prevents any change in the state of the capture flip-flops 40. When the capture enable signal EE disables the clock to the capture flip-flops 40, the capture flip-flops 40 ignore any information at their input and retain their previous state.
The EMIT bit signal is a single bit per microinstruction cycle generated by the bit position selector, to be described, of the register logic portion of the present invention, to be described (see FIG. 11). This EMIT bit signal provides the bit being compared by the serial adder/subtracters to the bit supplied by each respective memory component implementing an associative memory location.
It is noted at this point that the output of each of the eight OR gates 44 is connected to the input of a separate data path through multiplexer 42, and that the input of each OR gate 44 is connected from the output of the respective capture flip-flop 40. These connections are provided to implement the "capture" function of the capture flip-flops 40. The multiplexer 42 selects either the output of the OR gates 44 or the input from the input BI bus 22. The capture function is implemented as follows. Initially, the multiplexer 42 is set so that the input BI bus 22 can load a zero into the capture flip-flop 40. Then, on each of the succeeding microinstruction cycles, the multiplexer 42 is set to the other position so that the output of the serial adder/subtracter 36 through the OR gate 44 can be clocked into the capture flip-flop 40. The capture function is implemented by first initializing the capture flip-flop 40 to logic zero through the input BI bus, and then in successive microinstruction cycles, loading the capture flip-flop 40 with the logical OR, using OR gate 44, of the previous state of the capture flip-flop 40 and the comparison output from the serial adder/subtracter 36. If the numbers being compared are equal, then the output generated by the serial adder/subtracter 36 is a bit stream containing only logic zero bits. This means that the output of the OR gate 44 is the logical OR of the zero bit from the serial adder/subtracter 36 and the zero bit from the initialization of the capture flip-flop 40 for all microinstruction cycles of the comparison. The capture flip-flop 40, which is loaded with the output of the OR gate 44, remains zero. If, on the other hand, the numbers being compared differ, then at least one of the bits of the serial bit stream output generated by the serial adder/subtracters 36 is a logic one. This means that the output of the OR gate 44 is the logical OR of the previous content of the capture flip-flop 40 and, for at least one microinstruction cycle, a logic one from the serial adder/subtracter. The capture flip-flop 40 is thus set by the one from the serial adder/subtracter 36, and remains set by the one from its own previous output on the succeeding microinstruction cycles.
The output of each of the eight OR gates 44 is connected to one of the inputs of a single AND gate 46. The output of AND gate 46 is logic true if and only if the outputs of all the OR gates 44 are in the logic one state. This information is used to determine whether all the associative memory locations in a particular associative memory logic bank 20(n) have all their capture flip-flops 40 in the logic one state or will have all their capture flip-flops 40 in the logic one state on the next microinstruction cycle if the capture flip-flops 40 clock were enabled. It is noted at this point that the AND gate 46 inputs are wired from the OR gate 44 outputs, not from the output of the capture flip-flops 40, in order that the AND gate 46 can anticipate when the capture flip-flops 40 will be set to the all logic one state. For this reason, the AND gate 46 is called the "anticipated all capture gate" (AACG).
As previously stated, the data multiplexer 38 selects between the EMIT bit and the output of the serial adder/subtracter 36 of each respective associative memory location. The path from the EMIT bit is used so that the value of the EMIT bit can be directed through the multiplexer 38 into the data DI input of the RAM 34. This is how the function of writing into a location is accomplished. The other input to multiplexer 38, from the output of the serial adder/subtracters 36, is used when it is desired to increment or decrement the content of fields of the associative memory locations. It is noted that there are eight output from the serial adder/subtracter 36, one for each associative memory location of the associative memory logic bank, and therefore there are eight inputs to one port of the multiplexer 38. Since the EMIT bit is only a single bit, it is wired into each of the eight input to the other port of multiplexer 38. These connections are illustrated in detail in FIG. 7 wherein multiplexer 38 is seen receiving the EMIT bit wired to each position of one of the multiplexer ports. It is also noted at this point that bus buffer 48 is utilized to extract the output values of the capture flip-flops 40.
The memory selection logic portion of the present invention will now be described. The memory selection logic 50 of the present invention interconnects the associative memory logic banks 20(n) of the associative memory portion of the present invention via the input BI bus 22 and output BO bus 32, and the independent signals, AS, BE, EE, and AACG, of each associative memory logic bank 20(n). The memory selection logic 50 is comprised of two functional sections, the bank selection logic section 52 and the bit selection logic section 54.
The bank selection logic section 52 is used to control the activation of the associative memory logic banks 20(n) by generating an independent general enable AS for each associative memory logic bank 20(n). It also activates one of the independent output bus buffer enables BE to logically connect the output of the capture flip-flops 40 of a single associative memory logic bank 20(n) which it selects for input to the bit selection logic section 54. Similarly, the bit selection logic section 54 control the activity of the individual associative memory locations within each associative memory logic bank 20(n).
Internally, the bank selection logic section 52 contains a bank capture flip-flop 56 for each associative memory logic bank 20(n). The output of each bank capture flip-flop 56 is connected to the respective bank general enable AS. As is the case of the associative memory logic capture flip-flops 40, flip-flop contents of zero and one are defined as enable and disable, respectively. The memory component implementing a particular associative memory location within an associative memory logic bank 20(n) is enabled for reading and writing only if both its associative memory logic capture flip-flop 40 and its bank capture flip-flop 56 contain zero.
Bank multiplexer 58 supplies the input to the bank capture flip-flops 56. The multiplexer 56 selects either the output of the bank priority logic 60, the output of the bank decoder 62, or zero.
The bank priority logic 60 is used to determine the highest-priority bank containing at least one associative memory logic capture flip-flop 40 in the zero state. The inputs to the bank priority logic 60 are the independent outputs of the anticipated all capture gates AACG 46 from each associative memory logic bank 20(n). The anticipated all capture gate AACG signals pass through the anticipated all capture pipeline register for synchronization with the next microinstruction cycle. Both encoded and decoded priority output is provided by the bank priority logic 60. An eight-input gate-level implementation of the bank priority logic 60 is illustrated in FIG. 10 and will be described in detail below. The encoded output provides the most-significant input to the priority register and register logic to be described. The bank capture flip-flop input bank multiplexer 58 uses the decoded output. The decoded output also provides as independent output bus buffer enable BE to control buffer 48 of each associative memory logic bank 20(n).
The bank decoder and "zero" selections of bank multiplexer 58 are used to initialize the bank capture flip-flops 56. The bank decoder 62 is constructed such that the bits forming the decoded output are all ones except the output addressed by a field of the exchange register within the register logic to be described. This path permits the contents of the exchange register, to be described (See FIG. 11), to address a single associative memory logic bank 20(n) directly by loading all the bank capture flip-flops 56 with ones expect the bank being addressed by the content of the exchange register.
As stated previously, the bit selection logic section 54 is used to control the activity of the individual associative memory locations within each associative memory logic bank 20(n). This is accomplished through the input BI bus 22 and the output BO bus 32 which interconnect all the associative memory logic banks 20(n) in parallel.
The bit selection logic section 54 contains a bit decoder 64 driven by another field of the exchange register of the register logic portion to be described (See FIG. 11). The output of the bit decoder 64 is logically connected to the output BO bus 32 through its own bus buffer 66 which is compatible with the associative memory logic output bus buffers 48. In the preferred embodiment these buffers are three-state buffers which are well known. The output bus buffer 48 selected by the bank selection logic section 52 is forced to disconnect when the bit decoder output bus buffer 66 is enabled. This is accomplished by the control signal BDE. The bit decoder 64 works in conjunction with the bank decoder 62 so that a single associative memory location within a single associative memory logic bank 20(n) can be addressed by the content of the exchange register of the register logic to be described.
The bit selection logic section 54 also contains a bit priority logic circuit 68. This bit priority logic 68 is designed in the same manner as the bank priority logic 62 and is depicted in FIG. 10 to be described. The bit priority logic 68 prioritizes the bits found on the output BO bus 32. Its decoder output directly drives the input BI bus 22. Its encoded output generates the least-significant input to the priority register of the register logic portion to be described.
When an address of an associative memory location is placed in the exchange register of the register logic portion (See. FIG. 11), it must be decoded to select the appropriate associative memory logic bank 20(n) and the appropriate associative memory location within the selected bank. The address in the exchange register is split such that the most-significant bits of the address are connected to the bank decoder 62 and the least-significant bits of the address are connected to the bit decoder 64.
The bit decoder takes, in the preferred embodiment where there are eight associative memory locations per associative memory logic bank 20(n), a three-bit number and converts it into a one-of-eight output, more particularly, an output such that all bits are one except the bit corresponding to the associative memory location within the associative memory logic bank 20(n) being addressed. The output of the bit decoder is logically connected through bit decoder output bus buffer 66 to the output BO bus 32. The output of bit decoder output bus buffer 66 is also provided to the input of the bit priority logic 68. From the output of the bit priority logic 68, the bus buffer 66 output bits are passed to the input BI bus 22. The bit priority logic output selects as its one-of-eight output the same bit as its one-of-eight input. Thus, all the bits on the input BI bus 22 are ones except for the bit corresponding to the associative memory location within the associative memory logic bank 20(n) being addressed.
The input BI bus 22 is connected to all the associative memory banks 20 in parallel. Under microprogram control, to be described, the content of the input BI bus 22 is sent through multiplexer 42 (FIG. 5) to the capture flip-flops 40 of all associative memory logic banks 20. The output of the capture flip-flops 40 are the same as their input after the occurrence of the clock. Since the same input BI bus 22 content is clocked into the capture flip-flops 40 of all associative memory logic banks, one capture flip-flop in each associative memory logic bank 20(n) will contain zero and all the rest will contain one. The capture flip-flop containing zero is used to enable the associative memory location only in the bank selected by the most-significant bits of the exchange register, as shall be described. The output of each capture flip-flops 40 is connected to the enable input E of the corresponding RAM 34. If the enable input E is a one then the RAM will not permit its contents to be altered and will always generate an output of one. All the capture flip-flops 40 containing one thus disable their corresponding RAMs 34 implementing their corresponding associative memory locations. Only the RAMs 34 whose enable inputs E are zero have the potential of being accessed.
All associative memory logic banks 20(n) are connected to the same input BI bus 22 which means that the capture flip-flops 40 in each of the banks 20( n) will attempt to enable the location corresponding to the three least-significant bits which were provided originally from the exchange register. To select only the associative memory location in the bank specified by the most-significant bits from the exchange register, the RAMs 34 implementing each associative memory location have two enable inputs. One of these input is the enable input E described above. The other enable input, called the AS input, is connected to all the RAMs 34 of a single associative memory logic bank in parallel. Each RAM 34 implementing an associative memory location in enabled only if both the enable input E and the enable input AS are zero. If either or both are one, the RAM 34 for that location is disabled, thus preventing its contents from being altered and forcing its output to be one. The AS enable inputs are used to select the appropriate associative memory logic bank 20(n). With enable AS selecting the appropriate bank and enable E selecting the appropriate location with the banks, and single location within a single bank can be selected. The bit selection logic section 54 enable the appropriate enable E for the corresponding location within each bank 20(n) but only one bank is enabled because enable AS is generated by the bank selection logic section 52. The combination of the bit selection logic section 54 and the bank selection logic section 52 effectively restricts the selection down to a single associative memory location.
The three least-significant bits, in the preferred embodiment, go into the bit selection logic section 54 and the next three most-significant bits go into the bank selection logic section 52. The bank decoder converts the three most-significant bits into a one-of-eight signal such that one of the outputs is zero and the rest are one. The output of zero corresponds to the bank to be enabled. The output of the bank decoder 62 goes through the bank multiplexer 58 to the bank capture flip-flops 56. There is a single bank capture flip-flop for each associative memory logic bank 20(n) The output of each bank capture flip-flop 56 is connected to the respective enable AS input of the RAMs 34 implementing the associative memory locations for that associative memory logic bank 20(n).
The output BO bus 32 accesses the output of the capture flip-flops 40 via the bus buffer 48. In the preferred embodiment, the bus buffer 48 is a three-state buffer. When the bus buffer 48 is turned on, the contents of the capture flip-flops 40 are connected to the output BO bus 32. No more than one bus buffer 48 is turned on at any given time since the output BO bus 32 is capable of transferring the content of only one associative memory logic bank 20(n) at any given time.
In addition to the bus buffer 48 from each associative memory logic bank 20(n), the bus buffer 66 of the bit selection logic section 54 (FIG. 8) is also attached to the output BO bus 32. When bus buffer 66 is turned on, the output of the bit decoder 64 is connected to the output BO bus 32. Since the output of only one bus buffer can be logically connected to the output BO bus 32 at any given time, all bus buffers 48 of the associative memory banks 20 (n) are forced to be off when the control signal BDE, to be described, turns on the bit decoder bus buffer 66.
The technique whereby the present invention selects a unique location within the associative memory when more than one location satisfies a test condition, a situation existing when the capture flip-flop 40 of more than one location is in the zero (location enabled) state, is as follows. As in the case for the selection of a single location addressed by the exchange register described previously, the process of selecting a unique location from among those locations whose capture flip-flops 40 are in the zero state consists of first identifying a unique associative memory logic bank 20(n) containing one or more candidate locations, and then identifying a unique location within that bank. In the preferred embodiment, three bits are generated to identify the selected associative memory logic bank 20(n) and three bits are generated to identify the selected location within that bank. The two three-bit numbers are concatenated to form a six-bit result identifying a unique location among all locations. The process of selecting a unique associative memory location from all those locations whose capture flip-flops 40 are set is called prioritization.
There are two outputs from each associative memory logic bank 20(n) which may be seen at the lower left-hand corner of FIG. 5. The first is a single-bit output from an AND gate called the anticipated all capture gate 46 (AACG). The AACG 46 outputs from the respective associative memory logic banks 20(n) are collected at the bank selection logic section 52 where the selection of a unique bank is made. The second output is from the output bus buffer 48 and consists of a single bit from the capture flip-flop 40 of each associative memory location provided by a single associative memory logic bank 20(n). In the preferred embodiment there are eight locations per associative memory logic bank 20(n), and hence, eight bits of bus buffer 48 output and eight parallel binary signals comprising the output BO bus 32. The output of the bus buffer 48 of the associative memory logic bank 20(n) selected by the bank selection logic section 52 is transferred over the output BO bus 32 to the bit selection logic section 54 where the selection of a unique location within the selected bank is made.
The output of the anticipated all capture gates (AACGs) 46 of the associative memory logic banks 20(n) are collected and connected to independent input bits of the anticipated all capture pipeline register 70 of the memory selection logic 50 (FIG. 8. The purpose of the anticipated all capture pipeline register 70 is to synchronize the AACG outputs with the system clock. Only those bits corresponding to associative memory logic banks 20(n) which have at least one of their capture flip-flops 40 in the zero state are activated. The output of the anticipated all capture pipeline register 70 feeds the bank priority logic 60. The bank priority logic 60 has a decoded output and an encoded output. The decoded output consists of a bit corresponding to each bit of bank priority logic input. The bank priority logic 60 is designed such that no more than one decoded output bit is activated at any given time and the activated decoded output bit is selected from among those whose corresponding input bits are activated. The encoded output is a number representing the address of the associative memory logic bank 20(n) whose associated decoded output bit is activated. It is this encoded output which uniquely specifies the selected associative memory logic bank of the prioritize function. The encoded output of the bank priority logic 60 is connected to the most-significant input bits of the priority register to be described (FIG. 11). In the preferred embodiment there are eight associative memory logic banks 20(n), and hence, eight AACG outputs, eight-bits in the anticipated all capture pipeline register, eight bits of input to the bank priority logic, eight bits of bank priority logic decoded output, and three bits of bank priority logic encoded output (since eight log base two is three).
Each bit comprising the decoded output of the bank priority logic 60 is connected to the respective associative memory logic bank 20(n) output bus buffer 48 enable. Only the single decoded output bit which is activated will enable the corresponding bus buffer 48 connecting the capture flip-flops 40 of that associative memory logic bank 20(n) to the output BO bus 32. The activated decoded output of the bank priority logic 60 is used turn on the bus buffer 48 of the now unique associative memory logic bank. In other words, the only associative memory logic bank 20((n) that is connected to the output BO bus is the one selected by the bank selection logic section 52.
Now that a unique bank has been selected, the selection of a unique location within the selected bank is performed as follows. The outputs of all the capture flip-flops 40 of the selected associative memory logic bank 20(n) are connected to the output BO bus 32 by the bank selection logic section 52 as previously described. The output BO bus is directly connected to the bit priority logic 68 of the bit selection logic section 54. The bit priority logic 68 is a circuit similar to the bank priority logic 60, differing only in that the BDE signal which forces all the decoded outputs of the bank priority logic 60 to the deactivate state when the bit decoder bus buffer 66 is turned on is not present. The circuit used in the preferred embodiment is illustrated in FIG. 10. It has a decoded output and an encoded output. The decoded output consists of a bit corresponding to each bit of the bit priority logic input. The bit priority logic 68 is designed such that no more than one decoded output bit is activated at any given time and the activated decoded output bit is selected from among those whose corresponding input bits are activated. The encoded output is a number representing the address of the location within the selected associative memory logic bank 20(n) whose associated bit in the decoded output is activated. The encoded output of the bit priority logic 68 is connected to the least-significant input bits of the priority register to be described (FIG. 11). The concatenation of the encoded output of the bank priority logic 60 in the least-significant bits of the priority register and the encoded output of the bit priority logic 68 in the most-significant bits of the priority register provides a number uniquely identifying a single location from among all locations.
The decoded output of the bit priority logic directly drives the input BI bus 22. The prioritize function is completed by loading the content of the input BI bus 22 into the capture flip-flops 40 of all associative memory logic banks 20(n) in parallel and simultaneously loading the bank capture flip-flops 56 with the decoded output of the bank priority logic 60 through the bank multiplexer 58. As described previously, only the location for whom both the capture flip-flop 40 and the bank capture flip 56 are in the zero state (activated state) is enabled.
The capture enable logic 72 generates the signal EE used for turning on and off the clock of the capture flip-flops 40 of the associative memory logic banks 20(n).
To recapitulate the operations of the present invention thus far described with respect to FIG. 5 and FIG. 8, the bus functions illustrated on FIG. 6 are as follows.
The input BI bus 22 is parallel connected to all the associative memory logic banks 20(n) The number of wires comprising the input BI bus 22 is equal to the number of associative memory locations within a single associative memory logic bank 20(n). The signals on the input BI bus are generated by the bit priority logic 68.
The EMIT signal is a single wire connected to all the associative memory logic banks 20(n). The EMIT signal is used to supply the bit being compared with a bit in a selected associative memory location bit position, to load the content of a selected associative memory location bit position, and to supply a bit from a number being added to the content of a selected associative memory location bit position. The EMIT signal is generated by the emit generation logic 84.
The EE signal is a single wire connected to all capture flip-flops 40. The EE signal is used to turn on and off the clock to the capture flip-flops. The EE signal is generated by the capture enable logic 72.
The AS signals are general enables connected to the RAMs 34 of their respective associative memory logic bank 20(n). There is an independent AS signal dedicated to each associative memory logic bank 20(n). The AS signals are used to enable or disable read and write access to the RAM 34. The AS signals are from the outputs of the bank capture flip-flops 56.
The AACG signal is a single wire independently generated by each associative memory logic bank 20(n). The AACG signals are used to determine when all the capture flip-flops 40 of a particular associative memory logic bank 20(n) are expected to be set by the next microinstruction cycle. The AACG signals are connected to the anticipated all capture pipeline register 70 and to the capture enable logic 72.
The output BO bus 32 signals are connected in parallel to the output bus buffers 48 of all the associative memory logic banks 20(n). The number of wires in the output BO bus 32 is the same as the number of wires in the input BI bus 22. The output BO bus 32 is also connected to the bit decoder output bus buffer 66. The output BO bus 32 signals are the input to the bit priority logic 68.
The output bus buffer enables BE are single wires connected to each respective associative memory logic bank 20(n). The BE signals are used to turn on or off the output bus buffers 48. The BE signals are generated by the decoded output of the bank priority logic 60.
The register logic portion of the present invention will now be described, with reference to FIG. 11. The register logic portion 74 encompasses the interface to the host processor 12, the priority register 76, the exchange register 78, the queue priority counter 80, the real-time counter 82, and the emit generation logic 84.
The exchange register 78 holds the data word received from the host processor 14 during its write operation. Depending on the function invoked, the contents of the exchange register 78 may then be transferred to the clock register 82 or be used in serial form by the associative memory logic portion 50 through the emit generation logic 84. The exchange register 78 also holds the data output to be sent to the host processor 14 during its read operation. Depending on the function invoked, the contents of the exchange register 78 may originate from the clock counter 82, the priority register 76, or the associative memory logic portion 50. In the latter case, the exchange register 78 operates as a shift register to collect the bits generated by the associative memory logic portion 50 in serial form.
The priority register is a register which maintains the priority encoded result of the last prioritization of the capture flip-flops 40 of the associative memory logic portion 50. Input to the most-significant and least-significant halves of the priority register 76 is generated by the bank priority logic 60 and the bit priority logic 68, respectively.
The queue priority counter 80 is an up-down counter used with the queue priority algorithm to be described. The contents of the queue priority counter 80 can be incremented, decremented, and initialized with the content of the exchange register 78.
The real-time counter 82 is used as a clock to maintain the current time for use by the executive functions. The contents of the real-time counter 82 can be incremented or initialized with the content of the exchange register 78. The real-time counter 82 is partitioned into most-significant and least-significant portions for greater time range. The loading and incrementing of the real-time counter 82 is under the control of the microsequence control logic portion (FIG. 9), to be described, to insure proper synchronization with the executive function algorithms.
The register selection multiplexer 86 is used to permit the contents of the exchange register 78, the queue priority counter 80, either portion of the real-time counter 82, the priority register 76, the host processor data bus, or the host processor address bus to be loaded back into the exchange register 78. The exchange register 78 is always clocked. The transfer of the contents of the exchange register 78 back into itself is the mechanism whereby its contents are not altered. The register selection multiplexer is forced to select the exchange register 78 when the queue priority counter 80 or either portion of the real-time counter 82 is being loaded.
The EMIT bit, the output of the EMIT generation logic 84, is used by the associative memory logic banks 20(n) as a common data input to the serial adder/subtractors 36 and as a common input to the memory data multiplexers 38. The EMIT generation logic 84 consists of a serial adder with output flip-flop 88 and two multiplexers 90 and 92 called bit selectors. One bit selector 90 is wired to select any of the exchange register 78 bits, any of the queue priority counter 80 bits, or zero as one of the inputs of the serial adder 88. The other bit selector 92 is wired to select any of the real-time counter 82 bits or zero as the other input to the serial adder 88. The bit selectors 90 and 92 are wired such that when both selectors are selecting a bit from a register or counter as opposed to zero, they select the bit in the same relative bit position. The purpose of the serial adder is to enable the generation of a series of EMIT bits representing the sum of the exchange register 78 and the real-time counter 82, which is required for converting relative time intervals provided by the host processor 14 into absolute time relative to the real-time counter 82. When this summation function is not required, one of the two data inputs of the serial adder 88 is fed a zero by the respective bit selector. The output of the serial adder flip-flop 88 is passed through buffer 94. The output of buffer 94 is the EMIT bit.
In addition to selecting from among the registers and counters described previously, multiplexer 86 can also be directed to select the current host processor address and write data. These are derived from the address and data busses of the host processor memory interface.
The method used to implement a Dispatch Check executive function using the hardware executive 10 shall now be described. The dispatch check executive function seeks to identify the task with the highest priority that is in either the ready or the running task state. When more than one task has been assigned the same user priority, the highest priority task is the task most recently placed in the ready task state, excluding the currently running task. Tasks of the same user priority are thus queued on a first-ready-first-dispatched basis.
The software in the host processor supplies the content of the user priority field of the task table entry by directly writing into the field of the hardware executive table location for the respective task. Successively higher priorities are specified by successively lower positive numeric values of the priority field. Since the sequence of task creations and terminations is arbitrary, and since the user priority assigned to each task is also arbitrary, the tasks stored in the task table are not in any particular sequence with respect to priority.
Queue priority information is stored in a separate priority field maintained by the hardware executive called the queue priority field. The content of the queue priority field is supplied by the queue priority counter 80 under microprogram control. Each time a task enters the ready task state, the content of the queue priority counter 80 is loaded into the queue priority field of the respective task and the queue priority counter 80 is incremented. The queue priority counter 80 is incremented by the microinstruction decode logic to be described. Since high priority is defined by low positive numeric value in the priority fields, the tasks entering the ready state first will automatically have lower values and hence higher priorities in their queue priority fields compared to those that follow. To prevent the queue priority counter 80 from overflowing, the queue priority counter 80 and the queue priority fields of all the tasks whose queue priority fields are greater than the queue priority of the task leaving the ready task state are decremented. The queue priority counter 80 is decremented by the microinstruction decode logic to be described. The qualifying queue priority fields are first located by a comparison with the queue priority counter which upon completion leaves only their capture flip-flops 40 containing zeros. These selected queue priority fields are then decremented using the loop from the RAM 34, through the serial adder/subtracter 36 where the contents are decremented, and on the next microinstruction cycle, through the data multiplexer 38, to finally return to the RAM 34.
A unified priority scheme encompassing both the user and the queue priority fields is constructed by concatenating the priority fields. Since the queue priority has an effect only when the user priority fails to resolve to a single task with the highest priority, the user priority is more significant than the queue priority. For this reason, the user priority occupies the most-significant bits and the queue priority the least-significant bits of the concatenated priority field. This same principle is used regardless of the complexity of the priority resolution defined for a particular implementation.
The microsequence control logic 98 of the present invention will now be described with reference to FIG. 9. Microsequence control logic 98 generates the control signals for the rest of the logic of the computer hardware executive of the present invention. It contains the clock oscillator 100, the host processor interface control logic 102, the microprogram memory 104, logic to decode fields of the microinstruction into various control signals, and logic to generate the next microinstruction address.
The logic that generates the next microinstruction address to be accessed from the microprogram memory 104 for each microinstruction cycle is called the transform logic 106. Usually the transform logic 106 obtains the bit constituting the next microinstruction address from a field in the microinstruction. In the preferred embodiment, there is no counter circuit acting as a microprogram counter. The transform logic 106 is used to convert the address presented by the host processor 14, which signifies the executive function or direct executive table access requested, into unique microinstruction addresses. Signals from the host processor 14 indicating whether the access is a read or a write are used by the transform logic 106 in conjunction with the host provided address to generate unique microinstruction addresses for each combination within the executive function address space of the hardware executive 10. A single microinstruction address is generated for direct reads and another for direct writes into the executive table address space of the hardware executive. The transform logic also provides conditional jumps on the state of the anticipated all capture signal, which is in the true state if and only if all the individual anticipated all capture gate 46 outputs of the associative memory logic banks 20(n) indicate that all the capture flip-flops 40 would be set if clocked on the previous microinstruction cycle.
The connection between the transform logic 106 and the microprogram memory 104 carries the microinstruction address. The connection between the microprogram memory 104 and the microinstruction register 108 carries the next microinstruction accessed from the microprogram memory 104. The microinstruction register 108 is used to synchronize the microinstruction read from the microprogram memory 104 with the microinstruction cycle clock of the hardware executive 10. It is noted that a portion the bits constituting the output of the microinstruction register 108 is fed back to the transform logic 106 so that the respective bits of the microinstruction can be used by the transform logic to specify the next microinstruction address as described previously.
The bits of the microinstruction register 108 output not fed back to the transform logic are used by the microinstruction decode logic which generates the various control signals used by the rest of the hardware, i.e., DS, ES, EG, DBE, IQC, etc.
The power reset circuit 112 is connected to the transform logic 106 and is used to force the microinstruction address generated by the transform logic 106 is an initial start-up address, regardless of any other inputs to the transform logic 106, when input electrical power is first applied to the hardware executive. In the preferred embodiment, the initialization signal to the transform logic 106 is also generated when a master reset signal is received from the host computer 10 through the host reset input buffer 111.
The clock oscillator 100 provides the clock signal used by all the registers, counters, and flip-flops of the hardware executive 10. Each cycle of the clock oscillator corresponds to a microinstruction cycle.
The tick timer 114 and the tick flip-flop 116 are used to initiate time event processing. The tick timer 114 is an oscillator operating at a preset frequency that is low compared to the frequency of the clock oscillator 100 used to cycle microinstructions. A frequency between 100 Hertz and 1 Hertz is typical. The actual frequency selected matches the resolution desired for time intervals implemented by the time event executive functions. The tick timer 114 is wired to the tick flip-flop 116 such that each tick pulse from the tick timer 114 sets the tick flip-flop 116 indicating to the microprogram that a tick has occurred that needs to be processed. The microprogram starts processing a tick after completing any executive function or direct access in progress. When the microprogram processes the tick, it clears the tick flip-flop 116 so that tick processing will not be repeated for the same tick.
The command register 118 is used to save the identity of the executive function received by the hardware executive 10 from the host processor 14 when the host processor referenced the hardware executive address space. Command register 118 is fed by command multiplexer 120. When the command is an executive function, the command multiplexer 120 feeds the concatenation of the least-significant bits of address from the host processor, the read-write bit, and a hard-wired non-zero pattern of bits indicating that the executive function address space is being accessed to the command register 118. When the command is for a direct executive table access, the command multiplexer 120 feeds the concatenation of the read-write bit and a unique non-zero pattern of bits indicating that the executive table address space is being accessed to the command register 118. When neither address space is being accessed, the command multiplexer 120 feeds all zero bits to the command register 118. Thus the command register contains a unique pattern of bits for every possible command from the host processor 14.
The address space detector 115 consists of a comparator whose output indicates when the address on the host processor address bus is within the range of the hardware executive address space. The output of the address space detector is gated with the host request signal to prevent the host request signal from being received by the host busy circuit 102 when the request is for an address not within the hardware executive 10 address space. The address space detector 115 is also wired to the command multiplexer 120 to force the output of the command multiplexer 120 to zero as described above.
The executive function space detector 117 consists of a comparator whose output indicates when the host processor address is within the range of addresses dedicated to hardware executive functions. In the preferred embodiment, this component reduces to a direct connection to one of the bits of the host processor address which in combination with the address space detector output indicates when the host processor address is within said range. The output of the executive function space detector 117 controls the selection of the command multiplexer 120.
The control and memory bus signals generated by the host processor 14 for use by the hardware executive 10 use input buffer circuits internal to the hardware executive to match the electrical loading requirements of the host processor. The input buffers are the host request input buffer 101 (FIG. 9), the host read/write input buffer 119 (FIG. 9), the host reset input buffer 111 (FIG. 9), the host memory address input buffers 127 (FIGS. 9 and 11), and the host memory write data input buffers 85 (FIG. 11).
The control and memory bus signals generated by the hardware executive 10 for use by the host processor 14 use output buffer circuits internal to the hardware executive to match the electrical drive requirements and driver type, i.e., open-collector or three-state, of the host processor 14. The output buffers are the data ready output buffer 103 (FIG. 9), the busy output buffer 105 (FIG. 9), the interrupt output buffer 107 (FIG. 9), and the host read date output buffer 96 (FIG. 11).
The capture enable logic 72 shall now be described. The capture enable logic circuit (FIG. 8) generates the signal EE which controls the clock to the capture flip-flops 40. The capture enable logic receives the output of the anticipated all capture gate 46 from each of the associative memory logic banks 20(n). As described previously, these gates indicate whether the capture flip-flops 40 would be set to one, or remain one, if they were clocked. The function of the capture enable logic is illustrated in FIG. 12. The capture enable logic 72 is functionally comprised of a gate 122 feeding a multiplexer 124. The gate 122 forms from the individual outputs of the anticipated all capture gates 46 a single signal indicating whether all capture flip-flops 40 in all associative memory logic banks 20(n) would be set, or remain set, if they were clocked. The multiplexer 124 is controlled by the microprogram. When the multiplexer 124 selects the output of the gate 122, the multiplexer output EE allows the capture flip-flops 40 to be clocked if and only if so doing would not leave all the capture flip-flops 40 set to one. The other two selections of the multiplexer 124 cause the capture flip-flops 40 to be clock or not clocked respectively, regardless of the present state of the capture flip-flops 40.
TABLE I______________________________________HARDWARE EXECUTIVE FUNCTIONSExecutive Function Type Operand______________________________________INITIALIZE Write --RESERVE TASK Read Task Index = Task IDSUSPEND TASK Write Task Index = Task IDRESUME TASK Write Task Index = Task IDDISPATCH CHECK Read Task Index = Task IDTERMINATE TASK Write Task Index = Task IDRESERVE SEMAPHORE Read Semaphore IndexWAIT ON SEMAPHORE Write Semaphore IDSIGNAL SEMAPHORE Write Semaphore IDRELEASE SEMAPHORE Read Semaphore IndexRESERVE NORMAL Read Event IndexEVENTRESERVE TIME EVENT Read Event IndexCAUSE EVENT Write Event IDNORMAL EVENT CHECK Read Event IndexTIME EVENT CHECK Read Event IndexCANCEL EVENT Write Event ID______________________________________
TABLE II______________________________________MICROINSTRUCTION FORMAT______________________________________Bit 31Element Memory Write Control0 Read Reading is enabled for only those elements for whom both the Element Capture Flip-Flop and the Bank Capture Flip-Flop are not set. The Element Memory Output for disabled elements during a read operation is one.1 =106=30-Write Writing is enabled for only those elements for whom both the Element Capture Flip-Flop and the Bank Capture Flip-Flop are not set. The Element Memory Output of all elements during a write operation is one.Bits 30 28Capture Flip-Flop FunctionThe results of these functions appear at the CaptureFlip-Flop outputs at the beginning of the next cycle.Unless otherwise noted, the Element Memory Address Regis-ter is loaded with the contents of Bit Position field.0 0 0 No Change0 0 1 Clear All Bank and Element Capture Flip-Flops are cleared. The Clear function is used to initialize the Capture Flip-Flops before a search operation.0 1 0 Set All Bank Capture Flip-Flops are set. The Element Capture Flip-Flops are unchanged.0 1 1 Prioritize All Bank Capture Flip-Flops are set except the flip-flop for the bank containing the Element Capture Flip-Flop that has the lowest element address and is not set. All Element Capture Flip-Flops of the selected bank are set except the flip-flop of the selected element. The Ele- ment Capture Flip-Flops in all banks are set identically. The Priority Register is loaded with the selected element address. It is cleared when no element is selected. The Prioritize function normally follows a winnow function in order to select a unique element from all those elements not captured after a search operation.1 0 0 Exclusive Winnow If an Element Capture Flip-Flop is set, it remains set. Otherwise it is set if the output of the respective serial arithmetic unit is one and so doing does not leave all Element Capture Flip-Flops set. The Bank Capture Flip-Flops are cleared. The Exclusive Winnow function is used when searching for a field with the lowest numeric value. Since at least one field satisfies the search, the function inhibits the setting of any Element Cap- ture Flip-Flops if so doing will leave all of them set.1 0 1 Inclusive Winnow If an Element Capture Flip-Flop is set, it remains set. Otherwise it is set if the output of the respective serial arithmetic unit is one. The Bank Capture Flip-Flops are cleared. The Inclusive Winnow function is used when searching for a field whose contents are identical to some key. Since possi- bly no field satisfies the search, the function permits all the Capture Flip- Flops to be simultaneously set.1 1 0 Exchange Register Addressed All Bank Capture Flip-Flops are set except the flip-flop for the bank selected by bits 5 through 3 of the Exchange Register. All Element Capture Flip-Flops in each bank are set except the flip-lop selected by bits 2 through 0 of the Exchange Register. The Element Capture Flip-Flop in all banks are set identically. The Exchange Register Addressed function permits the specification of the element address by the host processor Write Data as required for the Suspend and Resume state change executive functions. It also permits the selection of the ap- propriate element during a direct read or write access by the host processor.1 1 1 Exchange Register Addressed Same as above.Bits 27 - 24Register Function0 0 0 0 Clear Exchange Register0 0 0 1 Increment Time Counter0 0 1 0 Increment Queue Priority Counter0 0 1 1 Decrement Queue Priority Counter0 1 0 0 Load Upper Time Counter from Exchange Register0 1 0 1 Load Lower Time Counter from Exchange Register0 1 1 0 Load Queue Priority Counter from Exchange Regis- ter0 1 1 1 Store Host Processor Address into Address Regis- ter Address Register bits 3 through 0 are always tak- en from Microinstruction bits 11 through 8. Address Register bits 7 through 4, which are nor- mally Microinstruction bits 15 through 12, are replaced by this function with Host Address bits 3 through 0.1 0 0 0 No Change1 0 0 1 Shift All Capture Flag into Exchange Register Each bit of the Exchange Register is shifted one place right. The most-significant bit is lost. The All Capture Flag is shifted into the least significant bit. The Shift Exchange Register function col- lects the bits read from successive bit positions of an element for return to the host processor during a direct read ac- cess.1 0 1 0 Store Queue Priority into Exchange Register1 0 1 1 Store Upper Time Counter into Exchange Register1 1 0 0 Store Lower Time Counter into Exchange Register1 1 0 1 Store Priority Register into Exchange Register1 1 1 0 Store Host Processor Data into Exchange Register1 1 1 1 Store Host Processor Address into Exchange Regis-terBits 23 - 22Serial Arithmetic FunctionInitialization of the Output and Carry flip-flops of theserial arithmetic unit occurs immediately. The resultsof the Add and Subtract functions are not available untilthe beginning of the next cycle.0 0 Clear Output, Clear Carry, Connect Output to Ele- ment Memory Data Input.0 1 Clear Output, Set Carry, Connect Emit Bit to Ele- ment Memory Data Input1 0 Add, Connect Output to Element Memory Data Input1 1 Subtract, Connect Emit Bit to Element Memory Data InputBits 21- 19Binary Operand SelectIf Bit 23 is zero, the output is cleared regardless ofthe contents of Bits 21 through 19. The results of thesefunctions are not available at the data inputs of theelement memory and the serial arithmetic unit until thebeginning of the next cycle.0 0 0 Zero0 0 1 Two0 1 0 Queue Priority The 16 Queue Priority Counter bit positions are addressed by the least-significant bits of the Bit Position field. The Queue Priority Counter supplies the contents of the task element queue prior- ity fields when tasks are moved to the ready or running task state. It is used to implement queuing within user supplied priority levels.0 1 1 One1 0 0 Time Plus Exchange Register The bit positions of the Time Counter and the Exchange Register are addressed by the least- significant bits of the Bit Position field. They must be addressed sequentially from least to most significant for the proper sum to by computed serially. This function is used to add a time in- terval suppled by the user through the Exchange Register to the current time maintained in the Time Counter to form the trigger time for time events.1 0 1 Time The 32 Time Counter bit positions are addressed by the least-significant bits of the Bit Position field. The Time Counter provides a time base for time-dependent and time-critical events. The output of the Time Counter is com- pared with the contents of the trigger time registered with timed events to determine if the event should be trig- gered.1 1 0 Exchange Register The 16 Exchange Register bit positions are ad- dressed by the least-significant bits of the Bit Position field.1 1 1 Zero Reserved for the future.Bits 18- 16Branch and Host Interface Control0 0 0 Clear Host Interface Busy Bit 0 of the next microinstruction address is zero. Host Interface Busy is cleared.0 0 1 Pulse Host Interface Data Available Bit 0 of the next microinstruction address is zero. Host Interface Data Available is strobed.0 1 0 Clear Tick Flag Bit 0 of the next microinstruction address is zero. The Tick Flag is Cleared. The Tick Flag is set by the tick interval counter. It is cleared by the micropro- gram after completing the triggering of timed events.0 1 1 Pulse Host External Interrupt The External Interrupt line is pulsed. The External Interrupt line is pulsed by the microprogram when a time-critical event is identified.1 0 0 Zero Bit 0 of the next microinstruction address is zero.1 0 1 One Bit 0 of the next microinstruction address is one.1 1 0 All Capture Flag Bit 0 of the next microinstruction address is zero if all the Element Capture Flip-Flops are set. Otherwise it is one.1 1 1 Transform Bit 0 of the next microinstruction address is one. Bits 8 through 1 of the next microinstruc- tion address are the logical bitwise OR of the command transformed from the host processor memory address lines and bits 7 through 0 of the microinstruction.Bits 15- 8Bit PositionThe Bit Position field specifies the element bit positionwithin the element memory by loading the Element MemoryAddress Register. Exceptions are noted in the descrip-tion of the Register Function field. It also specifiesthe register bit position when the Binary Operand Selectfield selects a register. The specified bit positionaddress is available to the element memory and selectedregister at the beginning of the next cycle.Bits 7- 0Next Microinstruction AddressThe Next Microinstruction Address field specifies bits 8through 1 of the next microinstruction address. Bit 0 ofthe next microinstruction address is generated by theBranch and Bus Control field.______________________________________
It is understood that the bit assignments illustrated in Table II above are by way of example only and could be assigned otherwise depending upon the particular design requirements. It is also noted that there are thirty-two bits in the microinstruction in the preferred embodiment of the present invention but it is to be understood that other numbers of bits may be utilized if desired.
Bit 31, for example, is a bit of the microinstruction register 108 which is hooked up to the WE input of all the RAMs 34. The WE inputs of each RAM 34 instructs the RAM whether it is to perform a read or write function.
The next field of the microinstruction, bits 30 through 28, control what the capture flip-flops are doing and these bits are directed to the capture enable logic 72 and the bit selection logic 54. If this field has 000 in it, the capture flip-flops 56 do nothing. The EE line is forced into a state such that the capture flip-flops 56 do not change state. If there is a 001, the capture flip-flops are cleared. 010 is a set function. 011 is the prioritize function. When a dispatch check executive function is performed, a single location address must be returned to the host processor. This function is used to examine all the capture flip-flops 40 which contain "zeros", to ignore all the capture flip-flops 40 which contain "ones" and to select from the ones containing "zero" a unique location. Tracing this prioritize function through the hardware executive 10 goes as follows. In order to prioritize across all locations, it first must be determined which bank 20 n has the priority being looked for and then the location (or element) within the bank 20 n is searched for the priority of interest. First, the output of the capture flip-flops 40 is routed through to the bank priority logic via the pipeline register 70. The bank priority logic 60 generates the bus enable BE for the bank 20 n selected. The bus enable BE is routed to the enable input of the particular bus buffer 48 to turn on the buffer 48 of the selected bank 20 n . That permits the content of the capture flip-flop 40 within that bank to come through the buffer 48 through the output BO bus 32 and into the bit priority logic 68 to select the location within the a.m.l. bank 20 n having the priority of interest. The outputs of the bit and bank priority logic, 68 and 60, respectively, are fed into the priority register 76. The bank and bit priority logic 60 and 68, respectively, also generate a decoded output which is sent, in the case of the bit priority logic 68 over the BI bus 22 and is eventually multiplexed into the capture flip-flops 40 by a multiplexer 42.
Thus the prioritize function places in the priority register 76 the selected location in the associative memory bank 20 n and changes the contents of the capture flip-flop 40 so that all the capture flip-flops 40 will contain "ones" except for the locations in the selected bank which will contain a "zero". It is noted that the BI bus 22 is wired in parallel to each of the banks so the result of the bit priority logic 68 will be fed to the capture flip-flop 40 of each of the banks 20 n . Thus, if location 2, for instance, of the selected bank 20 n was the selected location, then the capture flip-flops 40 in each of the banks 20 n associated with a number two location would appear to be selected. The function of excluding the selected locations from the nonselected banks 20 n is accomplished by the bank capture flip-flops 56. It is recalled that a RAM 34 is enabled only if its capture flip-flop 40 and its bank capture flip-flop 56 both indicate that the RAM 34 should be enabled. The bank capture flip-flops 56 are under control of the bank priority logic 60 and thereby will disable the non-selected banks 20 n .
A numerical value of 100 in bit positions 30 through 28 cause implementation of the exclusive winnow function which is utilized to perform a sort. A numerical value of 101 in bit positions 30 through 28 causes implementation of an inclusive winnow function which is utilized to perform a search function. Numerical value of 110 is the exchange register address function. Numerical value of 111 in bit positions 30 through 28 is the host processor address function.
There are two kinds of numbers which can be entered into the hardware executive 10, those numbers identifying addresses and those which constitute data. When an address is entered into the hardware executive 10 to perform one of the functions illustrated by the dotted lines of FIG. 1, the address supplied by the host processor 12 is converted into an enable signal to the appropriate associative memory 20 n location. This is most easily accomplished by setting or enabling its capture flip-flop 40.
The capture enable logic 72 may be implemented as follows with reference to FIG. 13. The capture enable logic 72 may be envisioned as an AND gate 122 feeding a multiplexer 124 as is illustrated in FIG. 12. The multiplexer 124 function is implemented as illustrated in FIG. 13 which shows the control lines of the multiplexer. There are eight inputs coming in from the AACG lines derived from the outputs of the AND gates 46 of each associative memory 20 n which feed the AND/OR invert gates 130. Bits 28 through 30 of the microinstruction register 108 are fed to the OR gate 132 and to the NOR gate 134 as is illustrated. These bits form the control lines of the multiplexer 124.
Each of the control signals furnished as inputs to the components of each associative memory logic bank 20 n illustrated in FIG. 5 will now be described as to what they do and how they interconnect with the remainder of the system. The write enable signal WE is connected to the microinstruction register 108 bit 31. This is the signal that constitutes the write enable for each of the RAMs 34. The SADSU and the SACLR signals control the serial adder/subtracters 36 and are connected to microinstruction register 108 bits 22 and 23, respectively. Signal SADSU tells the adder/subtracters 36 whether to add or subtract. Signal SACLR is used to initialize the serial adder/subtracters 36. Signal DS is the select input of the data multiplexer 38 and also is connected to microinstruction register 108 bit 22. The serial adder/subtracter 36 performs addition when the data multiplexer 38 selects the output of the serial adder/subtracter 36 and performs subtraction when the data multiplexer 38 selects the EMIT bit. The EMIT is a single bit which is wired to the input of the data multiplexer 38 and the serial adder/subtracter 36 for each associative memory location. Signal ES is the capture flip-flop multiplexer select signal and is wired to multiplexer 42 such that the multiplexer 42 selects from the BI bus 22 when microinstruction register 108 bit 29 is a "one". The capture flip-flop multiplexer 42 gate is wired such that the output of the multiplexer 42 is "zero" regardless of the input when microinstruction 108 bits 30 and 29 are both "zero". Bits 30 and 29 are thus ANDed and the AND gate output is sent to the multiplexer 42 as signal EG. The signal EE is the capture flip-flop 40 clock enable and forces new contents to be caught into the capture flip-flops 40 when both microinstruction register 108 bits 29 and 28 are not "zero". Otherwise, new contents are clocked into the capture flip-flops 40 only when neither microinstruction register 108 bits 30 nor 29 are "zero" and none of the All Anticipated Capture Gates (AACG's) outputs from the associative memory banks 20 n indicate that all their capture flip-flops 40 would otherwise be set if the clock occurred. BE is the associative memory bank output bus buffer 48 enable and connects the content of the capture flip-flops 40 of an associative memory bank 20 n to the output BO bus 32 when the signal BDE has not connected the bit decoder bus buffer 66 and the bank priority logic 60 has selected this bank. No more than one buffer can be connected to the output bus BO 32 at any given time. There is one BE input wire for each associative memory bank 20 n . Finally, the signal BDE is the bit decoder bus buffer 66 enable and this connects the output of the bit decoder 64 from the output bus BO 32 and the input of the bit priority logic 60 when microinstruction register 108 bit 28 is "one" and microinstruction register 108 bit 30 is "zero".
The address for a bit position location within an associative memory bank 20 n comes from two places, one place being from the microinstruction register 108 so the microcode can specify which bit position will be acted upon. However, when directly writing into the memory from the host processor 12 or when directly reading from the memory, the host processor 12 puts bits on its address bus specifying where in the memory the host processor 12 is looking; a portion of those bits are run directly into the A input of the RAM 34 when that function is implemented. This is accomplished by the multiplexer 128 and the address register 126 illustrated in detail in FIG. 14 and to be described more specifically below. By this connection of components, the bits which indicate which host processor "word" is involved come from the host processor memory address bus rather than from the microinstruction register 108. The same microcode may thus be used to load a word which the host processor is accessing regardless of where the word is located.
Referring now to FIGS. 9, 11 and 15, the register clock decoder 136 will be described. There are a number of signals which are used as clock pulses and are derived from clock oscillator 100 illustrated in FIG. 10 and which are channeled through the register clock decoder 136. The register clock decoder 136 sends these control pulses to various other components of the hardware executive 10. This decoder, shown in detail in FIG. 15, is part of the microinstruction decode logic 110 and may be implemented with a model 74LS138. Its select inputs are wired to bits 27 through 24 from the microinstruction register 108. Thus, for example, if bits 27 to 24 have 0001 in them, the register clock decoder 136 will send a pulse, ITC, to the real time counter 82 to increment the time counter. The other signals ZER, SPC, LUTC, LLTC, LQC and US are the signals which clear the exchange register, which clock the queue priority counter 80 which load the upper time counter of the real time counter 82, which load the lower time counter of the real time counter 82, which load the queue priority counter 80 and which switch the address register 126 via multiplexer 128, respectively.
The bit priority logic 68 and the bank priority logic 60 will now be described in detail with reference to FIG. 10. Both the bit priority logic network 68 and the bank priority logic network 60 are identical and in the present embodiment are comprised of eight NAND gates 140, 142, 144, 146, 148, 150, 152, and 154 in the decoded section and three NAND gates 156, 158, and 160 in the encoded section. The input to this priority circuit is "high" if it is desired that it be prioritized. The input is "low" if no action is to be taken. There are two general outputs, the decoded priority output 162 which is "active low" and the encoded priority output 164 which is "active high". The decoded output 162 selects a single signal from the eight signals coming in to the NAND gates 140 through 154, inclusive. The one selected output will be different from the other seven. Since the decoded output of the priority circuit is active "low", the selected output will be "low" and the others will be "high".
The encoded priority output 164 takes the output that has been selected by the decoded output 162 and generates a number specifying the output that was selected.
The highest priority input is the one on the right. If a high comes in on this NAND gate 154, for instance, there will be a low on the output of NAND gate 154. This low also connects to every other NAND gate of lesser priority, i.e. gates 140 through 152, inclusive. This low prevents all the other NAND gates of the priority circuit from turning on even if they have a high input. Thus, the highest priority signal will cause its NAND gate to have an active "low" output and will prevent all other NAND gates from having active "low" outputs.
The NAND gates 156, 158 and 160 will produce a "one" if any of their inputs goes "low". At most, only one of these inputs can go "low". The inputs to the encoded section 162 NAND gates 156, 158 and 160 are so wired that they select the bit positions from the decoded output to generate their number.
The random access memory 34 illustrated in block diagram in FIG. 5 will now be described in detail with reference to FIG. 17. Each RAM 34 is implemented as follows. It is noted at this point that in the preferred embodiment of the present invention, each RAM 34 comprises eight 256-word by one-bit RAM components 166 0 , 166 1 , . . . , 166 7 . Each component RAM (256×1) 166 represents a memory location (element).
The AS signal is the general bank enable signal, there being one such signal for each memory bank 20 n . This signal AS is fed through an AND gate at the input to each memory location RAM 166. These eight memory location RAMs are commercially available with he input AND gates 168 0 , 168 1 , . . . 168 7 . All the write enable lines WE are wired in parallel. All address lines from the address register 126 are wired in parallel. The AS signal is wired in parallel for all the 256×1 RAMs 166 within each bank 20 n . The AS signal for each bank 20 n are separate from each other. It can be seen in FIG. 17 that the write enable signal WE is generated from bit 31 of the microinstruction register 108. The common driver inverter 70 is used to generate a sufficient drive signal so as to power all the 256×1 RAM chips 166.
Referring now to FIG. 14 the address register logic comprised of address register 126 and multiplexer 128 will be described in detail. The address register logic generates the address inputs to all the RAMs in each associative memory bank 20 n . The purpose of this network is to allow the least significant bit of the host bus address to be switched into the associative memories 20 n so that a particular segment representing a host processor "word" can be read or written from the associative memories. Normally, the multiplexer 128 would connect the address inputs of the RAMs 34 directly to the microinstruction register 108 but this multiplexer 128 can be operated so as to allow the host address to come through directly.
The interconnection of the individual bits from the host address bus and from the microinstruction register 108, i.e. bits 0 through 3 and bits UR8 through UR15. respectively are shown connected as illustrated in FIG. 14 to multiplexer 128 and the address register 126. Also, the individual output bits of the address register 126 and the clock input to register 126 are illustrated in FIG. 14. The signal US is generated by decoder 172 which is illustrated in detail in FIG. 18a and is part of the microinstruction decode logic 110. The signal US is generated when the input to the decoder 172 is 0111, in the present example, this input being derived from bits 27 through 24 of the microinstruction register 108.
It is also noted at this point that the signal ZER from the decoder 172 output is used to clear the exchange register 78. Once the exchange register 78 is clear, the output of the exchange register 78 is used via the multiplexer 86 to clear the queue priority counter 80, the clock counter 82 and the other registers.
Referring now to FIG. 18b there are illustrated the various gates utilized to control the multiplexers 58 utilized in the memory selection logic section 50, generating, for instance, the KS and the KG signals which control the bank multiplexer 58. FIG. 18b illustrates what the "high" and "low" outputs, H and L, respectively, switch. The portion of the microinstruction decode logic 110 illustrated in FIG. 18b is comprised of NAND gate 174, inverter 176, NOR gate 178, inverter 180, and NOR gate 182 connected to bits UR 30 through UR 28 from the microinstruction register 108. These gates 174 through 182 generate the signals KS, KG, ES, EG and BDE, respectively.
Referring again to FIG. 18a, it can be seen how the signals ZER, ITC, IQC, DQC, LUTC, LLTC, LQC, and US are generated. It is understood that the overbar denotes active "low" signals. The signal ZER is utilized to clear the exchange register 78. The signal ITC is utilized to increment the time counter 82. The signal IQC is utilized to increment the queue counter 80. The signal DQC is utilized to decrement the queue counter 80. The signal LUTC is utilized to load the upper time counter portion of the time counter 82 and the signal LLTC is utilized to load the lower time counter portion of counter 82. LQC is the signal that is utilized to load the queue counter 80 and finally, as previously described US is the address register 126 control signal utilized as a control input to multiplexer 128.
Referring to FIG. 19 the priority register 76 illustrated in block diagram form in FIG. 11 is seen in detail along with its associated logic gates. The priority register 76 is comprised of register 184, the inputs to which are the least and most significant outputs from the bit and bank priority logic 68 and 60, respectively. Register 184 is controlled by microinstruction register bits UR 20 through UR 30 via inverter 186 and NAND gate 188. The register 184 will only record the value coming into its input when 011 is in the field of bits UR 28 through UR 30.
The host bus interface control logic 102 is illustrated in detail in FIG. 20. The host bus interface control logic 102 takes signals from and generates signals to the host processor 12. The host request enters from the host computer 12 and informs the hardware executive 10 that a particular function or address is available and that some action is required. The host request signals triggers the request if the address is in the hardware executive 10 address space. The Host Busy signal goes back to the host computer and informs the host that its request is being processed. The Host Busy line stays down until the request is processed. The host bus interface control logic 102 is comprised of decoder 190 and two pulse detector circuits 192 and 194. Two flip-flops, 196 and 198 connected as shown to decoder 190 generate the Host Data Ready and the Host Interrupt signals. The two pulse detect circuits 192 and 194 are fed by the decoder and the Host Request line 200 and also by the clock signal on line 202 via the tick timer 204 which is a frequency dividing counter.
The pulse detect circuits 192 and 194 are implemented as shown in FIG. 21 which illustrates the gates and flip-flops utilized to implement the pulse detect circuits. More particularly, the pulse detect circuits 192 and 194 are each comprised of three flip-flops 206, 208 and 210 and the AND/OR invert gate 212 which is comprised of AND gate 214, AND gate 216 and NOR gate 218. The timing diagram illustrated in FIG. 22 shows that when a host request comes in "low" into the D input of flip-flop 206, flip-flop 206 synchronizes the request with the hardware executive 10 clock coming in on line 202. As soon as the clock pulse from the hardware executive 10 rises, the Q output of flip-flop 206 goes "low" and the Q output of flip-flop 206 will go "high". At this point a "high" will appear at the Q output of flip-flop 208. These is a period of time where flip-flop 206 has a "zero" on its Q output and flip-flop 208 still has a "one" on its Q output. Gating the Q output of flip-flop 206 with the Q output of flip-flop 208 at the AND gate 214 results in a signal at the output of AND gate 214 which is a "one" for one cycle only, just after the request line has gone to "zero". The output of AND gate 214 goes through NOR gate 218 and since the input is a "one", the output of the NOR gate will be a "zero". This "zero" goes into the D input of flip-flop 210 and on the next clock cycle, the Q output of flip-flop 210 will generate the output signal which is used as the Host Busy signal returning to the host processor 12. Thus, when the request comes in, two clock cycles later, the Busy Signal will be generated. The foregoing is illustrated on the timing diagram of FIG. 22 where it is seen that when the second clock pulse arrives, the Host Busy signal goes down, indicating that the hardware executive 10 is processing the request. Once the Host Busy line goes down, the Q output of flip-flop 210 will be a high and is fed back into the input of AND gate 216, the other two inputs of which are normally "high". Thus, a high will appear at the output of the AND gate 216. This "high" will enter the NOR gate 218 and its output will be "zero" which will maintain the Host Busy line down. This line will remain down until either the clear input to AND gate 216 goes to "zero" or the reset input to the pulse detect circuit goes to "zero". The reset input is used for initialization purposes. The clear input is under microprogram control. It is controlled by the decoder 190 in the host bus interface control logic (FIG. 20) which is controlled by bits UR 18 through UR 16, inclusive, of the microinstruction register 108. A 000 on bits UR 18 through UR 16 of the microinstruction register 108 thus lowers the clear input to the pulse detect circuit 192. Relating decoder 190 to the microcode listing of Table II above, it is seen that the 000 code indicates the action of clearing the Host Bus Interface Busy line.
001 on bits UR 18 through UR 16 from the decoder 190 indicates that the data being returned to the host computer 12 is available to be read, etc.
The bottom portion of the host bus interface control logic 102 is used to generate the "tick". The system clock is divided down to a low frequency by the tick timer 114 which is a frequency divider/counter. It acts to count up to a predetermined count and then resets itself. The pulse detect circuit 194 is the same kind of circuit as the pulse detect circuit 192 previously described with respect to FIG. 21. The divider/counter 114 divides the clock 100 frequency down to the tick frequency and sets the pulse detect circuit 194 in the same manner that a Host Request sets the pulse detect circuit 192 for the Busy signal. However, the microcode implementing the various algorithms may not be ready to process the tick signal. Once the pulse detects circuit 194 is set, it is held in this condition until the next time the microcode executes the transform bits, i.e. the bits having values 111 in the field UR 18 through UR 16 described in more detail in Table II above.
When the microcode is available to process the "tick", the microcode that does process the tick can clear the pulse detector circuit 194. The "tick" signal is an indication that a tick has occurred and serves as a request that the microcode initiate an action. The tick enable, TICK E, is analogous to the Host Busy signal above and prevents the tick from being processed when some other function is in progress.
The transform logic 106 illustrated generally in block diagram form in FIG. 9 will now be described in greater detail with reference to FIG. 16. The purpose of the transform logic 106 is to take signals from various parts of the hardware executive 10 and generate a unique microinstruction address based on the previous state of the machine. The transform logic 106 may be conceptually divided into a mechanism for generating the least significant bit of the microinstruction, for generating the next least significant bit of the microinstruction, and for generating the rest of the bits of the microinstruction. When bits UR 16 through UR 18 of the microinstruction register 108 are 111 (see Table II above) the transform function is being implemented and is used to take information from the host processor 12 and direct it to the appropriate section of the microcode.
Transform logic section 106, as illustrated in detail in FIG. 16, is comprised of AND/OR invert gates 215 0 , 215 1 , 215 2 , 215 3 , . . . , 215 8 . AND/OR invert gate 215 0 is comprised of NOR gate 217 0 fed by the two AND gates 219 0 and 220 0 . Likewise, AND/OR gate 214 2 is comprised of NOR gate 216 2 which is fed by AND gates 219 2 and 220 2 .
Likewise, the AND/OR inverter 215 3 is comprised of a NOR gate 217 3 fed by AND gates 219 3 and 220 3 . Also, AND/OR inverter gate 215 8 is comprised of NOR gate 217 8 which is fed by AND gates 219 8 and 220 8 . The AND/OR inverter gates 215 4 through 215 7 (not shown) are identically constructed. The transform logic circuit 106 AND/OR inverter gate 215 1 is comprised of NOR gate 217 1 which is fed by three AND gates 219 1 , 220 1 and the AND gate 22. The remaining component of the transform logic 106 is the AND gate 224.
If the transform 106 is not enabled, i.e. bits UR 16 through UR 18 are not 111 (see Table II above), the output of AND gate 224 will be a zero which will cause disconnection of any of the AND gates 217 1 through 217 8 , inclusive.
In the case for all but the two least significant bits, the contents of the microinstruction 108 are fed back to the transform logic 106. The signals, for example, UR 7 and UR 2 are the outputs of the microinstruction register 108. These signals go straight through the AND gates 220 in each of the AND/OR invert gates 214 and exit the NOR gates 217. The reset line comes from the power reset circuit 112. If the reset line seen at the bottom right hand corner of FIG. 16 goes to zero, the output of the AND/OR invert gates 215 will be forced to microinstruction address zero, i.e. they will be all high, since this is active "low" logic. Since the reset is normally "high", microinstruction register signals UR going straight through the AND gates 219, 220 and 222 and the NOR gates 217 will be in effect. The reset signal thus turns off all the AND gates in the logic circuits 215 0 through 215 8 inclusive.
If the transform 106 is enabled, i.e. the microinstruction register bits UR 16 through UR 18 are 111 (see Table II above), then the AND gate 224 will be enabled. Consequently, the AND gates 219 will be enabled.
For all except the two least significant bits, the output T of the command register 118 will go through the AND gates of the AND/OR invert networks 215 when the transform 106 is enabled and the reset is not resetting. The output of these AND gates are OR'ed with the output coming from the microinstruction register loop, signals UR 0 through UR 7.
AND/OR invert gate 215 0 responds to the least significant bit from the output of the microinstruction register 108, i.e. bits UR 16 through UR 18 as is further defined in Table II above.
The next to the least significant bit is processed by the AND/OR invert gate 215 1 which has an extra AND gate 222 which allows the tick and tick enable signals into the transform logic 106. If the transform function is being performed and there is no reset signal and the tick enable is one, busy is zero, and there is a tick request from the pulse detect circuit 194, then a "one" input will be produced on the line denoted UA1.
Referring again to FIG. 9, one component thereof previously omitted from the discussion will now be described. More particularly, the all capture register and gate 226 generates the signal denoted ALLCAP. Referring to FIG. 23 the all capture register and gate 226 is illustrated in further detail. As seen in FIG. 23, the all capture register and gate 226 is comprised of three NOR gates 228, 230 and 232 followed by the all capture register 234 which supplies the inputs to NAND gate 236. The output of the NAND gate 236 is the signal ALLCAP which is sent to the transform 106 and the exchange register 78 shift inputs.
Above the command register 118 (see FIG. 9) is a multiplexer 238 which is controlled by the host command signal. Referring to FIG. 24 which illustrates in detail the multiplexer 238 and the command register 118, it is seen that there are two kinds of information which the host processor 12 can send to hardware executive 10. One type of information is that information indicating a function, like the Dispatch Check function and the other type of information is a request for a direct read or write. The host 12 provides the host command signal which controls the multiplexer 236 so there will be one set of bits entering the command register 118 if a function, like the Dispatch Check function, is requested and another set of bits is sent into the command register 118 if a read or write is to be performed.
A direct access if implemented by a read or write bit in the third position as is illustrated in FIG. 24. A function as opposed to a direct access is implemented by a "one" in the fourth bit position of the host address bus bits as is illustrated. Also entering the function bit locations are the least significant bits of the address bus from the host 12 directing the particular function to be implemented. The purpose of this interface comprised of the multiplexer 238 and command register 118 is to uniquely define what the hardware executive 10 is to do.
As an example of how the hardware executive 10 of the present invention works, implementation of a read function will now be described. In implementing a read function it is desired that the data be read from the host processor 12 directly in the hardware executive 10 associative memory 20 n . First, the host processor 12 puts out on its memory bus the address of the location to be read, a signal indicating that a read is to be performed vis a vis a write, a request signal to perform the read and a host command indicating an access operation as opposed to a function operation as is illustrated in FIG. 24.
Since this is a read function, the host command signal sets the multiplexer 238 to establish in the command register 118 the bit code corresponding to read function. The command register 118 will thus be loaded with this unique number as is illustrated at the upper left of FIG. 24 in the block entitled ACCESS. The hardware executive microsequencer (see FIG. 10) is performing the transform 106 function and will be cycling until the request signal enters the transform 106. The contents of the command register 118 will now be brought down to the transform logic network 106 where these contends are converted to a unique microinstruction address which essentially directs in the hardware executive 10 to the function to be performed in the microcode.
On the first microinstruction cycle, the host address is loaded into the exchange register 78 via the multiplexer 86. On the next cycle, the exchange register 78 output goes to the bit and bank decoder sections 64 and 62, respectively. The bank decoder 62 output goes to the bank capture flip-flops 56 via the bank multiplexer 58. The bit decoder output 64 goes to the bus buffer 66 through the bit priority logic 68 and thence on to the input BI bus 22. From there the information goes into the capture flip-flops 40 of each of the associative memory banks 20 n . A single associative memory location has now been selected and the information stored there will be read out. The address of the location within the selected memory banks is in the capture flip-flops 40. The host address plus the least significant bit of the word to be read are entered into the address register 126. The multiplexer 128 is set up such that the three least significant bits of the host address are concatenated with the bits from the microinstruction register 108 and there is thereby entered into the address register 126 the address of the bit position zero of the segment that is to be addressed from the host processor 12. The bit within the segment has been selected by the microinstruction register 108. The segment has been selected by the three least significant bits coming from the host address bus.
Next, the serial adder/subtracter 36 is initialized and the emit generation logic 84 is set up to put out a "zero" such that the "zero" is subtracted from the number coming from the memory.
The contents of the selected RAM 34 are now loaded into the registers at the outputs of the serial adder/subtracters 36 and meanwhile the host address plus bit 1 of the segment addressed are put in the address register. While the contents of the RAM 34 are being read out for bit position zero, simultaneously the address register 126 is being set up to obtain bit position one on the next cycle. This is known as "pipelining". All the serial adder/subtracters 36 and RAMs 34 are working in parallel but only the one that has been selected by the capture flip-flop 40 is putting out a "one" or a "zero". All the others are putting out ones.
The output of the serial adder/subtracters 36 is put through the AACG circuit comprised of the OR gate 44 and the AND gate 46 and from there goes through the ALLCAP circuit and thence into the shift input of the exchange register 78. OR gates 44 OR in a "one" from the capture flip-flops 40 corresponding to the locations not selected and a zero for the one that was selected. All OR gates 44 not corresponding to the selected location have "ones" and the OR gate corresponding to the bit position read has the bit read at its output. The AND gate 46 outputs will all be "one" except possibly the one that has been read. The AACG outputs of the AND gates 46 are sent around to the all capture register and gate 226 which generates the signal ALLCAP. This ALLCAP signal is sent to the shift input of the exchange register 78. One of the functions of the microinstruction bits UR 27 through UR 24 is that of shifting the exchange register 78 implemented by the code 1001 (see Table II above). Bit zero has been channeled through the ALLCAP circuit and is shifting into the exchange register 78. The following bits of the selected segment eventually fill up the exchange register 78 in this manner. When this happens, the word to be sent back to the host computer 12 is in the exchange register 78. The Host Data Ready signal is pulsed under control of microinstruction register 108 bits UR 16 through UR 18 (see Table II above). The host computer 12 then reads the word out of the exchange register 78. The Host Busy signal is cleared and the transform logic 106 is now ready to engage another function.
The write function begins as does a read function. The host processor in this case provides the data input. The host address of the location to be written into is put into the exchange register 78. The exchange register 78 output is processed through the bank and bit decoders 62 and 64, respectively, and into the capture flip-flops 40. The host data to be written is put in the exchange register 78. The host address and least significant bit of the segment to be written into are used to set up the RAM memory address with the four least significant bits of the host address and bit zero from the microinstruction register 108 to get the first bit within the selected memory location set up. The individual bits of the word to be written are selected on successive cycles as the EMIT bit via the bit selectors 90 and 92. The EMIT bit is then written into the DI input of the RAM 34 selected by the capture flip-flops 40 via the multiplexer 38. The only RAM component that will be written into is the one that has been enabled by the combination of signals from the capture flip-flops 40 (input E to the RAM 34) and the bank capture flip-flops 56 (signals AS). This cycle continues until all bit positions are written into and the Host Busy signal is cleared indicating to the host computer 12 that this function is complete.
|
The computer hardware executive is a special purpose associative processorhich interfaces to the memory bus of a digital computer to provide high-speed execution of executive functions. These functions include task registration, task synchronization, normal, time-dependent and time-critical event registration and triggering, hierarchical event-to-semaphore translation, and buffer allocation. The programmer invokes an executive function by accessing the address in the hose computer address space dedicated to that function. The data written to or read from that address is the function operated or result, respectively. The hardware executive maintains task and event tables internally within its associative memory. The memory is organized such that the same field bit position of all table entries is accessed in parallel within a microinstruction cycle. Searches are performed by sequencing through the bit positions of interest. The computer hardware executive also contains an internal clock for comparison against time-dependent and time-critical event registrations. The executive function algorithms are executed by an internal microprogram.
| 6
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a National Stage of International Application No. PCT/EP2011/000659 filed on Feb. 11, 2011, which claims priority from French Patent Application No. 1051170, filed on Feb. 18, 2010, the contents of all of which are incorporated herein by reference in their entirety.
The invention concerns a method of operating a braiding machine including a ring carrying spools of reinforcing fibers to braid successively a plurality of layers of reinforcing fibers around the same mandrel moved several times through the ring or around a plurality of mandrels moved one after the other through the ring.
BACKGROUND OF THE INVENTION
A braiding machine enables a composite material part to be fabricated by braiding around a mandrel and over the whole of its length one or more layers of reinforcing fibers superposed one on the other.
Once the various layers have been formed, the assembly constituted by the mandrel and the layers that it is carrying is placed in a mold to inject resin into these layers. This resin is then polymerized, for example by heating, to constitute a raw rigid part.
Such a braiding machine 1 , which is represented in FIG. 1 , essentially includes a ring 2 lying in a vertical plane, the revolution axis AX of this ring thus being horizontal. This ring 2 carries a set of spools of reinforcing fibers 3 that converge toward a point or a region situated on the axis AX and in front of the plane of the ring. These fibers thus conjointly define a generally conical shape.
When the braiding cycle is started, the mandrel 4 is moved along the axis AX to pass through the ring 2 beyond the point of convergence of the fibers. At the same time, the spools carried on the ring 2 by motorized mobile supports are actuated to fabricate a sock of reinforcing fibers on the external face of this mandrel 4 .
This sock covers the mandrel over the whole of its length once it has passed completely through the ring, i.e. once it is situated beyond the point of convergence of the fibers, which is itself offset relative to the ring.
The layer of reinforcing fibers is then cut downstream of the mandrel and the mandrel is demounted and then replaced behind the ring, in order to pass through it again for the formation of a second layer of reinforcing fibers radially superposed on the first.
In practice, the mandrel has its downstream end rigidly fastened to a rear rod and its upstream end rigidly fastened to a front rod by means of which it is pulled through the ring. The mandrel may to this end include at each of its ends a threaded hole, each rod then having a corresponding threaded end that is screwed into this threaded hole.
In operation, the layer of braided fibers surrounds the front rod, and is formed around the mandrel as the latter is pulled forward along the axis AX by this rod.
When this layer has been completely formed, a cord is passed through the braid, downstream of the mandrel, and this cord is tensioned parallel to the axis AX to maintain the point of convergence of the fibers in front of the ring and approximately on the axis AX.
The reinforcing fiber braid may then be cut between the mandrel and the region in which the cord passes through it. After this step, the front rod is unscrewed from the front end of the mandrel and the mandrel is unscrewed from the front end of the rear rod and extracted with the layer of reinforcing fibers that it is carrying.
The mandrel with the layer of fibers is then installed behind the ring again. The rear end of the rod that passes through the ring is then screwed into the front end of the mandrel and this rod, which was the rear rod in the previous step, then becomes the front rod.
Another rod is screwed to the rear end of the mandrel. These rods that are fastened to the mandrel are moreover retained in position on the axis AX by means of a plurality of bearings spaced from each other along the axis AX.
In practice, when the point of convergence of the fibers is held by the cord during removal and reinsertion of the mandrel, the position of this point of convergence is insufficiently well controlled to be sure that it remains centered on the axis AX, with the result that this point of convergence is offset radially relative to the axis AX.
Accordingly, when the mandrel is again installed in the machine and its front end is brought to bear against the area of convergence of the fibers, the radial offset of this area of convergence results in localized disorganization of the reinforcing fibers at the level of the end of the mandrel. The mechanical strength of the raw part produced is then significantly penalized at the level of this end.
One way to prevent this problem consists in operating the braiding machine so as to recenter the area of convergence of the carbon fibers before proceeding to remount the mandrel. However, this solution is costly in terms of fabrication time and increases the length of reinforcing fibers necessary for braiding each layer.
OBJECT OF THE INVENTION
The object of the invention is to propose a solution to remedy this drawback.
SUMMARY OF THE INVENTION
To this end, the invention consists in a method of operating a braiding machine including a ring carrying spools of reinforcing fiber for successively braiding a plurality of layers of reinforcing fibers around the same mandrel moved several times through the ring or around a plurality of mandrels moved one after the other through the ring, each mandrel being carried by a support movable through the ring along the axis of the ring, in which method, after passing a mandrel through the ring, the reinforcing fibers are cut downstream of this mandrel to be able to remove it, characterized in that:
a hub carried by the support and fastened to the mandrel is mounted downstream of the latter; the reinforcing fibers are tightened around the hub by means of a tie around these reinforcing fibers after passing the mandrel through the ring; and the reinforcing fibers are cut between the mandrel and the hub before removing the mandrel.
With this solution, the fibers can be held perfectly centered on the axis of the ring during removal of a mandrel. The fabrication cost is therefore reduced since it is no longer necessary to actuate the braiding machine to recenter the braid prior to the installation of a new mandrel.
The invention also concerns a method as defined above wherein a hub is used including at least one circumferential groove forming an imprint in which is accommodated the tie for attaching the reinforcing fibers.
The invention also concerns a method as defined above wherein a hub is used having a shape that is at least partly conical.
The invention also concerns a method as defined above wherein a hub is used having a biconical shape.
The invention also concerns a method as defined above wherein the hub has ends of different sections corresponding to the sections of a mandrel mounted upstream of this hub and a mandrel mounted downstream of this hub.
The invention also concerns a method as defined above wherein the support of the mandrel and the hub is formed by one or more rods extending along the axis and carried by at least two bearings situated on either side of the ring.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view showing the braiding of a layer of carbon fibers around a mandrel by means of a braiding machine.
FIG. 2 is a perspective view of the hub of the method of the invention.
FIG. 3 shows diagrammatically a step of the method of the invention in which the reinforcing fibers are assembled and tightened around the hub.
FIG. 4 shows a step of fabrication of a first layer of reinforcing fibers around the mandrel.
FIG. 5 shows a step of the method in which the fibers are tightened around the hub mounted downstream of the mandrel and the braided fibers are cut upstream and downstream of the mandrel.
FIG. 6 shows a step of the method of the invention corresponding to the removal of the mandrel with the braided layer that it is carrying.
FIG. 7 is a lateral view showing the mandrel and the hub in section.
FIG. 8 is a lateral view showing in section another mandrel and another hub associated with that mandrel.
DETAILED DESCRIPTION OF THE INVENTION
The basic idea of the invention is to mount a hub on the axis AX downstream of the mandrel and to use this hub to keep the area of convergence of the reinforcing fibers centered on the axis AX when removing the mandrel. In concrete terms, once the layer of fibers has been braided over the whole of the length of the mandrel, a tie or collar is placed and tightened around the fibers to clamp them against the hub in order to keep the area of convergence of these fibers centered on the axis AX.
The hub 5 , which is shown on its own in FIG. 2 , has a general shape of revolution about the axis AX. Here its external surface is generally conical and it includes two circumferential grooves 8 and 9 spaced from each other along the axis AX.
Each groove 8 , 9 constitutes a housing designed to receive a tie fitting tightly around the hub with the fibers surrounding the hub, so that this tie cannot slide along the external surface 7 when it has been tightened sufficiently to hold the area of convergence of the fibers in position.
In practice, and as can be seen in FIG. 3 , the reinforcing fibers 3 conjointly extend in a conical shape, the apex of which situated on the axis AX corresponds to their area of convergence. When the hub 5 is situated at the level of this area along the axis AX, it is surrounded by the reinforcing fibers, which then bear on its external face.
In this situation, by being clamped onto them, a tie or collar 11 around these fibers in line with one of the grooves 8 or 9 on the hub 5 enables these reinforcing fibers to be retained in position so that their area of convergence is kept on the axis AX with no radial offset.
FIG. 3 shows more particularly a braiding installation 1 at the beginning of a braiding operation. This installation includes a ring 2 carrying a series of spools of reinforcing fibers 3 , a support 12 carrying a mandrel 13 and a first hub 5 and a second hub 6 forming an assembly extending along the axis AX.
The first hub 5 is situated beyond the front end of the mandrel 13 , namely at the end of the mandrel that is farthest away from the ring 2 , toward the right in the figure. The second hub 6 is for its part situated in line with the rear end of the mandrel 13 .
The reinforcing fibers 3 are all clamped around the hub 5 by the tie 11 and the mandrel 13 is situated in the internal space delimited by the conical surface that the reinforcing fibers 3 form, for the purpose of braiding a sock of reinforcing fibers around this mandrel and over the whole of its length.
The support 12 may be constituted by four rods 12 a , 12 b , 12 c , 12 d . In this case, each rod has both ends threaded and each end of the mandrel 13 and of each of the hubs 5 and 6 includes a threaded hole into which a rod end is screwed.
Assembling the rods with the mandrel 13 and the hubs 5 and 6 consists in screwing one end of the rod 12 a to the front end of the hub 5 , screwing the front end of the rod 12 b to the rear end of the hub 5 , and screwing the rear end of the rod 12 b to the front end of the mandrel 13 . In a similar manner, the front end of the rod 12 c is screwed to the rear end of the mandrel 13 , the rear end of the rod 12 c is screwed to the front end of the hub 6 , and, finally, the front end of the rod 12 d is screwed to the rear end of the hub 13 .
The assembly constituted by the mandrel 13 , the two hubs 5 , 6 and the rods 12 a - 12 c constitutes a rigid whole held in position on the axis AX on the one hand by a first bearing at the rear, not shown, that is situated to the rear of the ring 2 , i.e. to the left of the ring in the figure, and on the other hand by traction means, not shown, to which the front end of the rod 12 a is fastened.
This bearing includes a fixed frame, optionally removable, comprising in its upper part members adapted to receive a rod to hold it in position on the axis AX and immobilizing it at least in rotation and possibly in translation. The traction means similarly include members receiving the rod and holding it in position on the axis AX, with translation and rotation locking members for pulling this rod along the axis AX.
The braiding operation is begun by moving the rigid assembly constituted by the support 12 with the mandrel 13 and the hubs 5 and 6 forward, i.e. toward the right in FIG. 3 , by actuation of the traction means that are not shown.
A sock is then braided around the mandrel in line with the point of convergence of the fibers, as the mandrel is moved, as shown diagrammatically in FIG. 4 , in which approximately half the sock has been braided, the point of convergence of the reinforcing fibers then being situated substantially half way along the mandrel.
As this movement continues, the layer of reinforcing fibers is formed over the whole of the length of the mandrel 13 , until the second hub 6 is in line with the area of convergence of the fibers, which corresponds to the FIG. 5 situation.
The installation is then stopped, and a tie or a collar 14 is passed around the second mandrel 6 to hold the reinforcing fibers in position at the level of their area of convergence. Once this operation has been effected, the braided layer 16 of reinforcing fibers is cut on the one hand between the front end of the mandrel 13 and the first hub 5 and on the other hand between the rear end of the mandrel 13 and the second hub 6 . These cuts are made by means of scissors or similar type cutting tools.
When the layer of reinforcing fibers has been cut upstream and downstream of the mandrel 13 , the mandrel is removed. In concrete terms, a second or rear bearing is advantageously installed temporarily to the rear of the ring 2 , complementing the first rear bearing and being spaced therefrom along the axis AX, to hold the rod 12 d completely in position on the axis AX. This rod 12 d being the one that is carrying the second hub 6 , its retention by the two rear bearings is sufficient to hold the area of convergence of the fibers 3 in position on the axis AX with no radial offset.
At this stage, the rod 12 a is uncoupled from the traction means that are not shown so that the assembly formed by the rod 12 c , the mandrel 13 with the layer that it is carrying, and the rods 12 b and 12 a may be unfastened from the second hub 6 by unscrewing the rear end of the rod 12 c that is screwed into the front end of this hub 6 .
The rod 12 a can then be demounted by unscrewing it from the front end of the first hub 5 . After this, this rod 12 a is on the one hand screwed into the front end of the second hub 6 and on the other hand coupled again to the traction means that are not shown. In a complementary way, one or two additional front bearings are advantageously installed temporarily to hold this rod 12 a coaxial with the axis AX.
At this stage, the rod 12 d is demounted by unscrewing it from the rear end of the second hub 6 , this second hub 6 then being held by the front hub 12 a that is itself carried by the traction means and the temporarily installed front bearings.
The first hub 5 is then unscrewed from the front end of the rod 12 b and then screwed into the rear end of the rod 12 c . The assembly formed by, successively, the first hub 5 , the rod 12 c , the mandrel 13 and the hub 12 b is then installed by screwing the front end of the rod 12 b into the rear end of the second hub 6 and then screwing the front end of the rod 12 d into the rear end of the first hub 5 .
At this stage, the disposition of the installation again corresponds to that of FIG. 3 , except that the positions of the first hub 5 and the second hub 6 are reversed relative to that which they occupy in FIG. 3 .
The braiding of a new layer of reinforcing fibers superposed on the first may then begin, if necessary after removing the front and rear bearings which have been installed temporarily. Different layers are then braided onto the mandrel until a predetermined thickness is reached.
In the example shown in the figures, the hubs 5 and 6 are separated from the mandrel 13 by a relatively large distance, but this distance can advantageously be smaller, enabling the length of the reinforcing fibers necessary for each layer, and therefore the cost of fabrication, to be reduced.
Accordingly, as shown in FIG. 7 , the distance separating each hub from the mandrel may be reduced to a minimum value d that substantially corresponds to the minimum space necessary for the tool for cutting the layer of reinforcing fibers.
In the example shown in the figures, the hub 5 includes two grooves for clamping the reinforcing fibers in two corresponding ties or collars, but a solution including only one groove may also be satisfactory, the choice of the number of grooves and collars or ties being essentially conditioned by the fabrication conditions.
In the same way, the exterior shape of the hub 5 is also chosen as a function of fabrication conditions. In the FIG. 8 example the hub 18 is disposed between two consecutive mandrels 13 and 17 having different diameters that are mounted one after the other on the support.
Under these conditions, the hub 18 has a biconical shape and features at its end 19 nearest the mandrel 13 a section corresponding to that of the mandrel 13 and at its end 21 nearest the mandrel 17 a section corresponding to the section of that mandrel 17 . The external surface of the hub 18 connects the contours of these two sections, whilst defining in its central region a constriction 23 constituting a groove designed to receive a tie for attaching the reinforcing fibers of the braided layer 22 .
The diameter of the end 19 is advantageously significantly less than the diameter of the mandrel 13 and, conversely, the diameter of the end 21 is advantageously significantly greater than the diameter of the mandrel 17 , so as to spread the braid to facilitate mounting this mandrel 17 between the two braiding operations.
This hub makes it possible to ensure continuity of the braided layer 22 between the first mandrel 13 and the second mandrel 17 so that the orientation of the fibers is not disturbed by the transition from one mandrel to the other.
As in the FIG. 7 example, the hub 18 is separated from each of the mandrels 13 and 17 by a distance d that corresponds to the minimum space for a tool for cutting the layer of reinforcing fibers.
Moreover, it is to be noted that in the FIG. 7 example the hub has an asymmetrical biconical shape. However, a hub having a biconical shape symmetrical with respect to its center could be suitable for some fabrication situations, notably when layers of reinforcing fibers are braided around different mandrels of the same diameter.
In the various examples shown in the figures, the mandrels have simple shapes of revolution, as do the hubs, but the invention also applies to situations in which the mandrel or mandrels has or have any other section, for example rectangular sections, in which case the hub or hubs used also have other sections corresponding to those of the mandrels.
If the mandrels and hubs have shapes that are not shapes of revolution, it is advantageous to ensure that these elements are not able to turn about the axis AX during the formation of the layer of reinforcing fibers. There may then be provision for the coupling between each support rod and each mandrel or hub to incorporate a transverse key passing through the end of the element concerned and the rod to prevent rotation of each element relative to the rod.
|
The invention relates to a method for the operation of a plaiting machine ( 1 ) that comprises a ring ( 2 ) carrying fiber spools ( 3 ) for plaiting layers ( 16, 22 ) of fibers ( 3 ) about a mandrel ( 13, 17 ) carried by a carrier ( 12 ) capable of movement along the axis (AX) of the ring ( 2 ), wherein after plaiting the fibers ( 3 ) are cut in order to withdraw the mandrel ( 13, 17 ), and that comprises: a hub ( 5, 6; 18 ) carried by the carrier ( 12 ) and secured to the mandrel ( 13; 17 ) while being mounted upstream therefrom; an operation for tightening the fibers ( 3 ) around the hub ( 5, 6 ; IS) with a link ( 11, 14 ) surrounding said fibers ( 3 ) after the mandrel ( 13, 17 ) has passed through the ring ( 2 ); and in which the fibers ( 3 ) are cut between the mandrel ( 13, 17 ) and the hub ( 5, 6; 18 ) before withdrawing the mandrel ( 13, 17 ).
| 3
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority benefit of U.S. Provisional Patent Application No. 61/087,250, filed Aug. 8, 2008, the contents of which are incorporated herein by reference in their entirety.
This invention was made under a contract with the United States Government Department of Energy, Contract No. DE-FG02-06ER84482.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to manufacturing of superconductor wire. More particularly, the invention relates to a method for manufacturing superconductor wire using high-tin compounds that have high melting temperatures.
2. Related Art
The conventional internal-tin process (IT) (see Eric Gregory, “Multifilamentary Superconducting Composites”, Concise Encyclopedia of Magnetic and Superconducting Materials, p. 332, 1992, Editor Jan Evetts, Pergamon Press, the contents of which are incorporated herein by reference in their entirety) and the conventional powder-in-tube process (PIT) (see C. A. M. van Beijen and J. D. Elen, IEEE Trans. Magn., MAG-15, 87, 1979, the contents of which are incorporated herein by reference in their entirety; and J. H. Lindenhovius, “SMI Activities and Plans on PIT Nb 3 Sn”, WAMS, Archamps, Mar. 23, 2004, the contents of which are incorporated herein by reference in their entirety) are the leading Nb 3 Sn conductor manufacturing approaches that have the potential to meet the High Energy Physics (HEP) goals of performance and cost for high field magnets such as the LHC luminosity upgrade. Along with the standard bronze process, schematics of both approaches are compared in FIG. 1 . The main advantage of both the IT and PIT approaches is that they have more tin available (up to 20%) for Nb 3 Sn formation, where as the bronze approach is limited to 13% by weight. See A. Godeke, “Performance Boundaries in Nb 3 Sn Superconductors”, Ph.D. Thesis, 2005, University of Twente, Enshede, The Netherlands, the contents of which are incorporated herein by reference in their entirety.
Because of the higher availability of tin in both the IT and PIT approaches, significant progress has been achieved toward improving the non-Cu JC (critical current density, Amps/mm 2 ) performance. For example, the performance goal set by the conductor advisory group has been attained by the IT approach. See R. M. Scanlan and D. R. Dietderich, “Progress and Plans for the U.S. HEP Conductor Development Program”, IEEE Trans. On Appl. Super., Vol. 13, No. 12, p. 1536, June 2002, the contents of which are incorporated herein by reference in their entirety. The J c (12T, 4.2K) has been reported at or exceeding the 3,000 A/mm 2 . See J. A. Parrell et al., “High Field Nb 3 Sn Conductor Development at Oxford Superconducting Technology”, IEEE Trans. On Appl. Super., Vol. 13, No. 2, p. 3470, June 2003, the contents of which are incorporated herein by reference in their entirety. The non-Cu J achieved by the PIT approach is about 2,400 A/mm 2 at 12T. See Lindenhovius, supra. These high J c performance characteristics are not possible with the bronze process due to lower tin availability.
Both the IT and PIT begin with a subelement. See Gregory, supra, and Godeke, supra. In the case of the IT, a Cu/Nb composite with solid niobium filaments imbedded in the copper matrix is hot extruded. After extrusion, the composite is gun drilled to form a hole at the center of the array of niobium filaments. A solid tin rod is then inserted into this composite and further processed to a size for restacking into a copper tube for design and fabrication of a multifilament conductor. The restacked billet is then cold drawn to final wire size.
In the case of the PIT approach, a copper-clad niobium tube is filled with an intermetallic NbSn 2 powder compound, plus additional free tin and copper powder. The PIT subelement is then processed to a final restack size and, like the IT approach, is assembled into another copper tube to fabricate the final multifilament wire.
A weakness of the IT process is the additional cost involved in gun drilling a long length of extruded composite rod. A weakness of the PIT approach is the inherent high cost of preparing the NbSn 2 intermetallic powder due to high cost of niobium and processing.
The cost to fabricate the IT Nb 3 Sn superconductors is on the order of $2 to $4 per meter. The cost associated with the PIT process is currently greater than $4 per meter. In contrast, the cost of state-of-the-art NbTi superconductors manufactured for the MRI industry is on the order of $0.50 to $1.00 per meter. See L. D. Cooley, A. K. Ghosh, and R. M. Scanlan, “Costs of high field superconducting magnet strands”, the contents of which are incorporated herein by reference in their entirety. If the cost of a Nb 3 Sn process could be reduced to the same level as the current state-of-the-art production levels of NbTi, then this higher performance conductor could become the conductor of choice for various commercial applications such as for example MR imaging and NMR spectroscopy. A low cost Nb 3 Sn conductor could allow magnet engineers new design opportunities toward reducing volume and weight of the overall magnet for a given applied magnetic field without sacrificing performance. Such a conductor would also have significant cost implications for large scale magnet projects such as upgrades for the Large Hadron Collider and the International Fusion machine.
Earlier conductor developments have replaced the solid tin core of the sub-element in the IT process with salt cores. See W. Marancik, S. Hong, and R. Zhou, “Method for Producing Multifilamentary Niobium-Tin Superconductor”, U.S. Pat. No. 5,534,219, Jul. 9, 1996, the contents of which are incorporated herein by reference in their entirety. The sub-elements with the salt cores are then assembled into a multifilament array as schematically depicted in FIG. 1 . This assembly is then hot extruded. The result is a fully bonded multifilament composite with removable inert salt cores. The inert salt cores are then dissolved with jets of water leaving behind longitudinally extended channels which are symmetrically distributed with reference to the transverse cross-section of the conductor. These channels are then filled with solid tin followed by further drawing the composite to a final wire size.
In practice, the size of the salt cores need to be relatively large after extrusion in order to dissolve the salts with jets of water. However, in modern high critical current IT conductors (for example RRP process, see Parrell, supra), it is desirable to increase the number of sub-elements such that the sub-element diameter is less than 100 microns at final wire diameter. This means the sub-elements with the salt cores would be too small for practical removal by water jet dissolution of the salts. Thus, the approach has been limited to a small number of sub-elements that may be designed into a multifilament billet.
Another recent IT development to reduce cost is the “Mono Element Internal Tin (MEIT) conductor. See B. A. Zeitlin, B. Gregory, J. Marte, M. Benz, T. Pyon, R. Scanlan, and D. Dietderich, “Results on Mono Element Internal Tin Nb3Sn Conductors (MEIT) with Nb7.5Ta and Nb(lZr+Ox) Filaments”, IEEE Trans. on Appl. Supercond., Vol. 15. No. 2, pp. 3393, June 2005, the contents of which are incorporated herein by reference in their entirety. The approach in this process reduces the steps by eliminating the final restack assembly of 19 or 37 IT sub-elements as depicted in the schematic of FIG. 1 . In this approach, the sub-element is hot extruded and drawn into a multifilament wire. This approach takes advantage of the cost effective large scale assembly of the subelement in a similar manner to MRI production size NbTi billets. However, a weakness of this approach is the fact that after extrusion, the composite must be gun-drilled to form a hole for the insertion of solid tin. This operation is expensive since very few companies worldwide specialize in this operation for superconducting composites. Moreover, gun-drilling a long length rod could result in an off center hole and damage the inner filaments. Furthermore, MRI extruded production scale rods are about 3 to 4 inches in diameter, 30 feet long and not perfectly straight. Technology to drill a straight hole over such a length does not exist. An example of MEIT conductor design is shown in FIG. 2 . The central region is filled with solid tin after the extrusion and is surrounded by an array of solid niobium filaments in a copper matrix.
In the PIT process, NbSn 2 is the high tin source with about 72% tin by weight. It is an extremely hard compound and difficult to fracture, making this approach expensive to fabricate. Drawing this wire with PIT sub-elements containing the hard NbSn 2 is difficult. The addition of ductile tin powder to micron size NbSn 2 powder in early as well as more recent advanced designs of PIT wires enables processing long piece lengths of wire. See H. Krauth, A. Szulczyk, M. Thoener, and J. Lindenhovius, “Some Remarks on the Development of Commercial NbTi and Nb 3 Sn Superconductors”, in Progress on Nb-Based Superconductors, p. 91, Editors, K. Inoue, T. Takeuchi, and A. Kikuchi, Feb. 2-3, 2004, the contents of which are incorporated herein by reference in their entirety; C. V. Renaud, L. R. Motowidlo, and T. Wong, “Status of powder-in-tube Nb 3 Sn conductor development at Supercon”, IEEE Trans. Appl. Supercond., Vol. 13, No. 2, pp. 3490-3493, 2003, the contents of which are incorporated herein by reference in their entirety; and L. R. Motowidlo and G. M. Ozeryansky, “A Nb 3 Sn Conductor via Cu 5 Sn 4 PIT Process for High Field Applications”, Adv. In Cryo. Eng., Vol. 54, p. 269, Jul. 16-20, 2007, the contents of which are incorporated herein by reference in their entirety. See also Matt Jewell et al., “Novel Approaches to Forming Nb 3 Sn”, 2005 Low Temperature Workshop, Napa, Calif., the contents of which are incorporated herein by reference in their entirety. Low temperature hydrostatic extrusion of PIT composite wires is presently being explored by groups in Europe to develop a large-scale process. However, reports so far indicate some difficulties with wire drawing. This may be due to the hard nature of NbSn 2 and/or the lack of true bonding from low temperature hydrostatic extrusion. Moreover, it is still an expensive process due to the inherent high cost of the micron size Nb powder and the high cost of processing to form the intermetallic micron size NbSn 2 powder. Furthermore, large scale hydrostatic presses are few worldwide with limited access for extrusion.
Referring to FIGS. 3 a and 3 b , in general, PIT Nb 3 Sn wire utilizing NbSn 2 or Cu 5 Sn 4 has shown a porous remnant of the core after final reaction and diffusion of the tin into the niobium tube. Another general feature of PIT Nb 3 Sn wires is large Al5 grains on the inner diameter of the reacted layer. Both features are undesirable. These general features have also been observed in recent PIT development work with FeSn 2 , Ni 3 Sn 4 , and YSn 2 high-tin compounds. See L. R. Motowidlo, “An Extrudable Low-Cost Nb 3 Sn PIT Conductor for Applications to HEP Magnets”, Phase II SBIR ER84482, the contents of which are incorporated herein by reference in their entirety. FIG. 3 illustrates a porosity and a large grain size of PIT Nb 3 Sn wire utilizing Cu 5 Sn 4 cores.
In summary, both of the conventional IT and PIT processes have not achieved simultaneously all the cost/performance goals for a true manufacturing process suitable for production and application of advanced high energy accelerator magnets, fusion magnets, or commercial MRI and NMR magnets. A truly low-cost manufacturing process for Nb 3 Sn conductors, like the state-of-the-art NbTi utilized in commercial MRI machines, has not been fully established to date, and thus, the present inventors have recognized that there is a need for such a process.
SUMMARY OF THE INVENTION
In one aspect, the invention provides a method of manufacturing Nb 3 Sn superconductor wire. The method comprises the steps of: producing a high-tin intermetallic powder compound; preparing a catalyst powder compound; mixing the high-tin intermetallic powder compound with the catalyst powder compound to produce an intermetallic powder mixture; introducing the intermetallic powder mixture into a tube to form a mono-element, the tube including copper cladding and the tube comprising one of niobium or a niobium alloy; cold-drawing the mono-element to a first predetermined diameter; assembling a plurality of mono-elements into a multi-element billet; hot-extruding the assembled multi-element billet to produce at least one multifilament billet containing Nb 3 Sn; and forming a wire having a second predetermined diameter by cold-drawing the at least one multifilament billet through a plurality of dies. The high-tin intermetallic compound may comprise MnSn 2 .
The step of producing the high-tin intermetallic MnSn 2 compound may include the steps of: introducing a first predetermined amount of elemental manganese into a mixer or shaker; introducing a second predetermined amount of elemental tin into the mixer or shaker; mixing the elemental manganese with the elemental tin to produce a combination of manganese and tin; subjecting the combination of manganese and tin to a heat treatment such that MnSn 2 is produced; mechanically grinding the produced MnSn 2 into a first plurality of particles having a particle size not exceeding a first predetermined maximum size; and jet milling the first plurality of particles into a second plurality of particles having a particle size not exceeding a second predetermined maximum size. The first predetermined amount of elemental manganese may be approximately equal to 19% by weight of the combination of manganese and tin, and the second predetermined amount of elemental tin may be approximately equal to 81% by weight of the combination of manganese and tin. The first predetermined amount of elemental manganese may include a first plurality of manganese particles, each of the first plurality of manganese particles having a size less than or equal to 44 microns. The second predetermined amount of elemental tin may include a second plurality of tin particles, each of the second plurality of tin particles having a size less than or equal to 44 microns.
The step of mixing may further comprise mixing the manganese with the tin under an argon atmosphere. The step of subjecting the combination of manganese and tin to a heat treatment may further comprise subjecting the combination of manganese and tin to a temperature of approximately 500° C. for approximately 72 hours. The first predetermined maximum size may be equal to 150 microns. The second predetermined maximum size may be equal to 5 microns.
The catalyst powder compound may comprise CuTiSn. The step of preparing the catalyst CuTiSn compound may comprise the steps of: introducing a first predetermined amount of elemental copper into a mixer or shaker; introducing a second predetermined amount of elemental titanium into the mixer or shaker; introducing a third predetermined amount of elemental tin into the mixer or shaker; subjecting the combination of copper and titanium and tin to a heat treatment such that CuTiSn is produced; mechanically grinding the produced CuTiSn into a first plurality of particles having a particle size not exceeding a first predetermined maximum size; and jet milling the first plurality of particles into a second plurality of particles having a particle size not exceeding a second predetermined maximum size. The third predetermined amount of elemental tin may be approximately equal to 38% by weight of the combination of copper and titanium and tin.
The step of mixing the high-tin intermetallic powder compound with the catalyst powder compound to produce an intermetallic powder mixture may further comprise mixing a first amount of the high-tin intermetallic powder compound with a second amount of the catalyst powder compound to produce an intermetallic powder mixture, wherein the first and second amounts are selected in accordance with a predetermined ratio. The predetermined ratio may be approximately equal to 1:1. When the tube comprises a niobium alloy, the niobium alloy may be selected from the group consisting of the compositions of Nb-1% Zr, Nb-1% Zr-x % Gd, Nb-1% Zr-x % Y, and Nb-1% Zr-x % Nd.
In another aspect, the invention provides a method of manufacturing Nb 3 Sn superconductor wire. The method comprises the steps of: producing a high-tin intermetallic powder compound; preparing a catalyst powder compound; mixing the high-tin intermetallic powder compound with the catalyst powder compound to produce an intermetallic powder mixture; introducing the intermetallic powder mixture into a tube to form a mono-element, the tube including copper cladding and the tube comprising one of niobium or a niobium alloy; cold-drawing the mono-element to a first predetermined diameter; assembling a plurality of mono-elements into a multi-element billet; cold-drawing the assembled multi-element billet into at least one multifilament billet; and forming a wire having a second predetermined diameter by cold-drawing the at least one multifilament billet through a plurality of dies. The high-tin intermetallic compound may comprise MnSn 2 . The catalyst powder compound may comprise CuTiSn. When the tube comprises a niobium alloy, the niobium alloy may be selected from the group consisting of the compositions of Nb-1% Zr, Nb-1% Zr-x % Gd, Nb-1% Zr-x % Y, and Nb-1% Zr-x % Nd.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates schematics of several conventional Nb 3 Sn manufacturing process designs.
FIG. 2 shows an exemplary Mono Element Internal Tin (MEIT) conductor design.
FIGS. 3 a and 3 b illustrates a porosity and a large grain size of PIT Nb 3 Sn wire utilizing Cu 5 Sn 4 cores.
FIG. 4 a shows an analysis of and an illustration of a solid core within the PIT sub-elements after completing a heat treatment reaction as part of a method of manufacturing Nb 3 Sn superconductor wire using a PIT process according to a preferred embodiment of the present invention according to FIG. 4 .
FIG. 4 b illustrates a PIT core interface with a reaction layer as observed while performing a method of manufacturing Nb 3 Sn superconductor wire using a PIT process according to a preferred embodiment of the present invention.
FIG. 5 shows a flow chart that illustrates a method of manufacturing Nb 3 Sn superconductor wire using a high-tin intermetallic compound such as manganese-tin, according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In order to attain a low cost PIT process for an advanced multifilament Nb 3 Sn design, new intermetallic compounds with tin must be substituted for NbSn 2 . In addition, a lower cost Nb alloy tube must be substituted for the current Nb7.5Ta tube utilized in state-of-the-art PIT conductors.
It is an object of this invention to utilize a new high-tin intermetallic powder compound. In a preferred embodiment, this intermetallic compound is MnSn 2 . Another object of this invention is to utilize a Nb-1% Zr alloy tube. The purpose of Nb-1% Zr is to reduce the cost of the tube from approximately $288/lb to approximately $90/lb.
MnSn 2 has a melting point of about 550° C. and contains 81% tin by weight. This particular compound has unique unexpected characteristics. An important characteristic discovered while investigating this compound was the result of a solid core within the PIT sub-elements after the heat treatment reaction was complete. This is shown in FIG. 4 a . Porosity within state-of-the-art PIT Nb 3 Sn conductors is an undesirable by-product of this process as shown in FIGS. 3 a and 3 b . A porous core within each PIT sub-element adjacent to the brittle Nb 3 Sn reacted layer does not provide any mechanical support. The lack of mechanical support may cause cracks within the reacted Nb 3 Sn layer if external stresses are applied to the conductor. These hoop stresses on the conductor are produced due to the so-called Lorentz forces during operation of an electromagnet.
Another interesting feature discovered with MnSn 2 as the high-tin source are the grains at the interface between the Nb 3 Sn layer and the MnSn 2 PIT core. The size of the grains and more importantly the overall thickness of this region are compared to the Nb 3 Sn layer in FIG. 4 b . The overall thickness of the grains at the Nb 3 Sn layer/PIT core interface are smaller in comparison to the large grain remnants and thickness obtained after reaction in the state-of-the-art PIT wire shown in FIGS. 3 a and 3 b . This is also an important result since large grains do not contribute substantially to the performance of the conductor as do the small grain region of the Nb 3 Sn layer. Reducing the layer thickness or eliminating this large grain region may improve the overall PIT efficiency of the noncopper area and increase relatively the small grain region for higher superconducting transport.
Both features are believed to be unique to the MnSn 2 compound and in contrast to other PIT conductors that exhibit porous and large grains after reaction.
Method of Manufacture
Preparation of the Intermetallic Powder Compound
Referring to FIG. 5 , flow chart 500 illustrates a method of manufacturing superconductor wire using a high-tin intermetallic powder compound according to a preferred embodiment of the present invention as shown in FIG. 4 . In the first step 505 , elemental manganese and tin having up to 44 micron particle size is weighted to include 81% tin by weight tin and 19% manganese by weight, then mixed in a SPEX 8000 mixer/mill or production size shaker under an argon atmosphere. Depending on the billet size, an appropriate amount of phase pure MnSn 2 is prepared. In the case of MnSn 2 , it was found that a heat treatment condition of 500° C. for 72 hours is appropriate. Variation from this temperature and time may be applied to produce nearly phase pure material. Once the compound has been produced, mechanical grinding by a mortar and pestle produces less than 150 micron particle size. Further processing is performed by jet milling the MnSn 2 compound to less than 5 microns. In the second step 510 , a catalyst powder compound is prepared. In order to promote the reaction of tin with the Nb or Nb alloy tube, copper must be included in the core. Copper is a necessary catalyst to form Nb 3 Sn. Also, titanium is included to enhance the critical magnetic field. In this process, we preferably prepare a CuTiSn compound containing 38% tin by weight and 10% titanium by weight; however, other weight percentages of tin and titanium may be used. This compound is prepared by weighting elemental copper, titanium, and tin with starting particle size of about 44 micron size. The fabrication of the CuTiSn compound to less than 5 microns is performed in a similar method described for the fabrication of MnSn 2 . In the third step 515 , once both compositions have been prepared, the intermetallic powders are mixed and blended together using a mechanical mixer. The combination of MnSn 2 and CuTiSn is prepared in the ratio of 1 to 1. This PIT composition provides a sufficiently thick Nb 3 Sn layer of approximately 10 microns as shown in FIG. 4 b . Reducing the CuTiSn addition to 20 wt % will increase the tin content of the PIT core and may further increase the Nb 3 Sn layer thickness.
Preparation of the PIT Sub-Element and Multifilament Processing
In the fourth step 520 , after preparation of the PIT MnSn 2 +CuTiSn core composition, the intermetallic compound is introduced into a niobium or niobium alloy tube to form a mono-element or sub-element. The niobium alloy tube may be a composition of Nb-1% Zr, Nb-1% Zr-x % Gd, Nb-1% Zr-x % Y, Nb-1% Zr-x % Nd. The powder compound is introduced by pouring into the tube to tap density of approximately 4 g/cm 3 . The copper clad niobium or niobium alloy tube is closed at each end using copper plugs and swaged tight. In the fifth step 525 , the mono-element is mechanically processed using an industry standard cold drawing schedule until the mono-element is reduced to a desired diameter for assembly into a multifilament billet in step 530 for further processing to final wire diameter. The number of PIT sub-elements assembled in step 530 depends on the desired application and may vary from 19 to several hundred PIT sub-elements. The starting billet diameter of the multifilament billet may be up to 300 mm, with a starting length of up to 1000 mm long, for production-size processing using hot extrusion; alternatively, the starting billet diameter of the multifilament billet may be up to 100 mm, with a starting length of up to 5000 mm long, for production-size processing using cold drawing. After assembly, the billets are closed by welding a nose and lid. In the seventh step 535 , the assembled multifilament billet is processed using either a hot extrusion process or a cold drawing process. Finally, in the eighth step 540 , the multifilament billet is processed to a final desired wire diameter by cold drawing through a series of dies.
While the present invention has been described with respect to what is presently considered to be the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
|
A method for forming Nb 3 Sn superconducting wire is provided. The method employs a powder-in-tube process using a high-tin intermetallic compound, such as MnSn 2 , for producing the Nb 3 Sn. The use of a high-tin intermetallic compound enables the process to perform hot extrusion without melting the high-tin intermetallic compound. Alternatively, the method may entail drawing the wire without hot extrusion.
| 8
|
BACKGROUND INFORMATION
1. Field of the Invention
The present invention relates to the field of trash containers. More particularly, the invention relates to tarps for securing the trash-receiving opening in the rear of a trash container.
2. Description of the Prior Art
A compactor receiver container (CRC) is a trash container that receives compacted trash. The CRC has an opening in the rear vertical container panel and is otherwise enclosed. Large stores, for example, typically have a trash collection site that includes a trash compactor installed in a trash disposal room and a CRC stationed to receive trash directly from the compactor. The CRC, once filled, is towed away by a tow vehicle to a waste disposasl site for emptying and then returned to the trash collection site.
A frequent nuisance when moving the CRC away from the trash collection site is that trash falls out of the opening onto the ground. The typical CRC removal procedure thus includes multiple steps: the driver of the tow vehicle first moves the CRC away from the wall, then gets out, picks up trash that has fallen onto the ground, and finally manually secures a tarp over the opening. The tarp is secured by elastic cords, rope, or the like. Having to clean up trash from the ground is an avoidable waste of time. Furthermore, it can take considerable time and effort for a single person to secure the tarp over the opening of an overfilled CRC. A further disadvantage of the current practice is that the cords securing the tarp may fray and/or break, with trash then spilling out onto the ground during transit to the waste disposal site.
In an effort to simplify the process of securing the trash opening in the CRC, Brown (U.S. Patent Appl. Pub. 2002/0139493) devised a spring-loaded tarp assembly for covering the trash opening of a CRC, which makes it easier for the operator to secure a tarp over the trash opening. A disadvantage of this tarp assembly is that the tarp must be manually lowered and secured by the operator. Another disadvantage is that the tarp is pulled from the upper edge of the trash opening downward, to be secured at the lower edge of the CRC. This does not eliminate the problem of trash spilling from the trash opening as the tarp is pulled down. Furthermore, due to the force of gravity, trash in an overfilled CRC will tend to work its way out of the CRC at the bottom of the tarp, even when it is properly secured.
A further nuisance related to the use of the CRC is that once it is transported away from the trash collection site, there is often nowhere to put trash that spilled out of the CRC. When the CRC is picked up for emptying, it is typically not replaced with another one at that time. Rather, the CRC is brought to the waste disposal site and then returned to the trash collection site. If someone does go out and pick up any spillage, there is no CRC or other large container available for stowing the trash until the CRC is returned. As a result, the spillage is quite often left to blow around the parking lot until the empty CRC is returned.
What is needed, therefore, is a tarping system for a CRC that does not require manual intervention by the operator of the trash tow vehicle. What is further needed is such a device that automatically covers the trash opening when the CRC is moved away from a wall. What is yet further needed is such a device that prevents trash from falling from the CRC onto the ground, even when the opening in the CRC is not fully covered.
BRIEF SUMMARY OF THE INVENTION
For the reasons stated above, it is an object of the present invention to provide a tarping system for a CRC that automatically covers the trash opening in the CRC when it is moved away from a wall. It is a further object to provide such a device that prevents trash from falling from the CRC on the ground, even when the trash opening in the CRC is not fully covered.
The objects of the invention are achieved by providing a tarping system that automatically swings a tarp over the trash opening of a CRC, from the bottom up, when the CRC is moved away from a wall. The term “CRC” as used hereinafter includes both 40-yard and 100-yard trash containers, the key feature of the CRC being that the trash opening is in the rear of the container and not on the top. The tarping system according to the invention comprises a tarp, tarping bar, and an actuating means. One end of the tarp is secured to the bottom of the trash opening of the CRC and the other end attached to the tarping bar. When in the “open” mode, the tarping bar is held in an open position against or in the vicinity of the lower edge of the opening; in a “closed” mode, the tarping bar is held in a closed position against the rear panel above the upper edge of the trash opening. With the tarping bar in the open position, the tarp is folded or pleated between the tarping bar and the rear panel of the CRC; with the bar in the closed position, the tarp is unfolded and pulled upward to cover the entire trash opening of the CRC.
The tarping system according to the invention encompasses at least two embodiments; one that is strictly mechanical in operation and one that is power-assisted. Electromechanical, electromagnetic, hydraulic, or pneumatic devices may provide the power assistance. In the mechanical embodiment, the actuating means for moving the tarping bar between the open and closed positions is a spring-loaded tension assembly comprising a tension spring attached at one end to a cable and at the other end to a pivot end of the tarping bar. The pivot end of the tarping bar is pivotably mounted on a pivot pin that is attached to the rear panel of the CRC, near a side edge of the trash opening. The actuating means in this mechanical embodiment is a tensioner that applies tension to the tension spring, which then forces the tarping bar to swing about the pivot pin through a semicircular arc, from its open position in which the tarping bar is positioned at or near the lower edge of the trash opening to the closed position, in which the tarping bar is positioned at or near the upper edge of the trash opening.
The tarp itself is attached to the rear panel of the CRC, around the lower half of the trash opening, and to the tarping bar. The contour of the tarp is such that it has sufficient fabric to allow the tarping bar to swing through a full semicircular arc from the open position to the closed position, to completely cover the trash opening.
When the CRC is in position for receiving compacted trash from the trash compactor, the tarping bar is held in the open position, without any tension on the spring, of a safety chain or other retaining means. Before moving the CRC away from the compactor, the safety chain or other retaining means is released. The tensioner is moved to a position that applies tension to the spring, which biases the tarping bar to move upward. The CRC is then moved away from the compactor site by the tow vehicle. As the CRC moves away from the compactor site and the tarping bar is free to move upward, the tension spring pulls the end of the tarping bar about its pivot pin, forcing the tarping bar upward into the closed position and thereby automatically pulling the tarp upward over the trash opening. Once in the closed position, the tarping bar may be secured against the rear panel of the CRC by means of safety chains, elastic shock cords, or other means, to prevent the bar from being jostled open in transit. Additionally, a lock is included that locks the tarping bar in the down or “open” position to prevent the bar from accidentally snapping up.
This mechanical embodiment of the tarping system is particularly advantageous for several reasons. The spring force can be very fast-acting, so as to snap the tarping bar up toward the closed position within a very brief span of time. This is desirable, because the faster the trash opening is closed, the less able trash is able to spill. Also, the tarping system requires no power source, other than the force exerted to apply tension to the spring. This is advantageous because the CRC itself does not have a power source. Because the CRC is not always returned to the same trash collection site, and some trash collection sites do not have the means to provide a power, it would require some logistical effort to ensure that a CRC with a power-assisted tarping system is not placed at a trash collection site that has no means of providing power.
In a power-assisted tarping system, the power-assists may include hydraulic, pneumatic, and/or electromagnetic means for moving the tarping bar. In such an embodiment, the actuating means includes a control module or power switch, ideally located on the rear panel of the CRC, and a power-assist unit, such as an electric motor with winch, or hydraulic unit with piston and cylinder.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements.
FIG. 1 is a front view of the preferred embodiment of the automatic tarper according to the invention, showing the automatic tarper in its open position.
FIG. 2 is a front view of the automatic tarper of FIG. 1 , showing the automatic tarper in its closed position.
FIG. 3 is an illustration of the automatic tarper of FIG. 1 as it moves from the open position to the closed position.
FIG. 4 is a front view of a tarp of the automatic tarper according to the invention.
FIG. 5 is a front view of a second embodiment of the automatic tarper according to the invention.
FIG. 6 is a front view of a third embodiment of the automatic tarper according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 illustrate a preferred embodiment of an automatic tarper 100 according to the invention for automatically covering a trash opening O in a CRC C. FIG. 1 shows an open position of the automatic tarper 100 and FIG. 2 a closed position. The trash opening O is located in the rear vertical panel of the CRC and has a lower edge O L , an upper edge O U , and side edges O S . The automatic tarper 100 comprises an actuating assembly 110 , a tarping bar 160 , and a tarp 180 . The tarp is generally depicted with cross-hatching. In the embodiment shown, the actuating assembly 110 is mounted on each side of the trash opening O, with the two assemblies being the mirror reverse of each other. When the automatic tarper 100 is in the open position, the tarping bar 160 is positioned slightly below the lower edge O L and along the lower portions of the side edges O S and is spring-biased to spring upward to the closed position. In the closed position, the tarping bar 160 is positioned above or near the upper edge O U of the trash opening O. When moving to the closed position, the tarping bar 160 pulls the tarp up over the trash opening O.
The actuating assembly 110 comprises a tension spring 132 , but in the embodiment shown, the assembly includes an actuator 111 , a tensioner bar 116 , and a tension assembly 112 , which includes the tension spring 132 . The actuator 100 , in this preferred embodiment, is a simple lever that is fixedly connected to the tensioner bar 116 , which is rotatably mounted on the rear panel of the CRC C with mounting brackets 113 . The tension assembly 112 includes a tension cable 114 , a tension spring 132 , and an adjustment means 120 . One end of the tension cable 114 is fixedly attached to the adjustment means 120 and the other end to the tension spring 132 . The adjustment means 120 is connected to the tensioner bar 116 via a swing bar 122 that is fixedly attached to the tensioner bar 116 . The adjustment means 120 in this embodiment includes a turnbuckle 126 that is connected at one end to the swing bar 122 via a shackle 124 and at the other end to the tension cable 114 .
FIG. 1 also illustrates the attachment of the tension spring 132 to the tarping bar 160 . The tarping bar 160 is U-shaped, with side arms 162 and a horizontal bar 161 therebetween. Each side arm 162 is pivotably mounted to a pivot bar 165 that is fixedly mounted on the side edge O S of the CRC C at a pivot point 166 . A pivot end 164 of the side arm 162 extends beyond the pivot pivot point 166 and has an eye for receiving a fastening means 143 of the tension spring 132 . In the embodiment shown, the fastening means 143 is a hook. When tension is applied to the tension spring 132 , it exerts a downward force on the pivot end 164 , biasing the tarping bar 160 to the closed position.
Tension is applied to the tension spring 132 by rotating the lever 111 from a tension release position, shown in FIG. 1 , downward to a biasing position, shown in FIG. 2 . This swings the swing bar 122 approximately 180 degrees about the axis of the tensioner bar to its biasing position in which a pull is exerted on the tension cable 114 and on the pivot end 164 , which in turn biases the tarping bar 160 to move to the closed position.
Several safety features are incorporated into the automatic tarper 100 . A tension lock 128 is provided, to lock the tension assembly 112 into the open or biased position. In the embodiment shown, the tension lock 128 is a simple bar that prevents the tarping bar 160 from swing outward. A safety chain 190 is attached to the horizontal bar 161 . This chain may be attached to the CRC C to prevent the tarping bar 160 from moving toward the closed position and may also be attached to the upper edge O U , when the CRC is being readied for transit, to secure the tarping bar 160 in the closed position. Eyes for receiving hooks are generally provided along the upper edge O U of the conventional CRC and a simple, effective means of securing the tarping bar 160 for transit is to hook the safety chain 190 to one of the eyes.
FIG. 3 is a side view of the automatic tarper 100 , illustrating the motion of the tarping bar 160 , as the CRC C is pulled away from the trash compactor site. As shown, the tarp 180 is attached to a bottom edge of the CRC C and to the lower half of the side edges of the trash opening O. As the tarping bar 160 swings upward approximately 180 degrees, it pulls the tarp 180 up over the rear panel of the CRC C, thereby closing the trash opening O. Conventional CRCs have a recessed area R on the rear panel, shown in FIGS. 1 and 2 . In the embodiment shown, the actuating and tensioning components of the automatic tarper 100 are installed in this recess R.
FIG. 4 is a front view of the tarp 180 . The tarp 180 includes a main section 182 , two side sections 181 A, 181 B and a sleeve 182 . The side sections 181 A, 181 B are triangular shaped pieces having an extra width at the top edge that corresponds to the length of one of the side arms 162 . The sleeve 182 is constructed to fit over the side arms 162 and the horizontal bar 162 , leaving the pivot ends 164 of the side arms 162 free. The bottom edge of the main section 183 is affixed to the lower edge O L and the side sections 181 A, 181 B are affixed to the lower halves of the two side edges O S . The top edge of the side sections 181 A, 181 B have an extra width that is dimensioned such that the tarping bar 160 is able to swing through a full semicircular arc. Any suitable means may be used to affix the main section 183 and side sections 181 A, 181 B to the edges of the trash opening O, such as rivets, adhesive means, hook-and-loop fastener strips, hooks and eyes, snap fasteners, clamps, or any combination thereof.
FIGS. 1–4 illustrate the various components of the preferred embodiment of the automatic tarper 100 . Ideally, the components are incorporated into a pre-assembled unit that is mounted in the recess R as a single unit, with essentially only the tarping bar 160 extending out beyond the recess. The pre-assembled unit simplifies installation of the tarping bar 160 , as it eliminates the need to measure carefully the specific mounting locations of the various components on the CRC C.
FIG. 5 illustrates a second embodiment of the invention that is a winch-operated automatic tarper 200 . The automatic tarper 200 comprises an electrical actuating assembly 210 , the tarping bar 160 and the tarp 180 . The actuating assembly 210 includes a winch 220 with a cable 230 , a motor 240 , a switch or control module 250 and a power cord 260 for connecting to an external energy source. The cable 230 is attached to the pivot end 164 of the side arm 162 of the tarping bar 160 . To raise the tarping bar 160 to the closed position, the switch 250 is actuated and the the motor 240 energized. The winch 220 turns, shortening the length of the cable 230 and thereby forcing the tarping bar 160 to pivot about the pivot point 165 . Ideally, the electric actuating assembly 210 is mounted at the rear of the CRC C and is actuated while the operator has the automatic tarper 200 in view, to ensure that it is not actuated while persons are working in the area.
FIG. 6 illustrates a third embodiment of the invention that is a hydraulically driven automatic tarper 300 comprising a hydraulic actuating assembly 310 , the tarping bar 160 and the tarp 180 . The hydraulic actuating assembly 310 includes a piston 320 with an operating end 350 , a cylinder 330 , and quick connectors 340 A, 340 B that connect the cylinder 330 to a hydraulic fluid reservoir. The operating end of the piston 350 attaches to the pivot end 164 of the side arm 162 and, depending on whether the piston 320 is being extended or retracted, forces the tarping bar 160 to the open or the closed position, respectively. The hydraulic piston and cylinder system is well known and is not described with any detail herein.
It is understood that the embodiments described herein are merely illustrative of the present invention. One skilled in the art may contemplate variations in the construction of the automatic tarper without limiting the intended scope of the invention herein disclosed and as defined by the following claims.
|
A tarping system that automatically covers and prevents trash from spilling from a trash opening in the rear vertical panel of a CRC. The tarping system automatically draws a tarp from the lower edges of the trash opening up over the opening, effectively closing the opening completely. The lower edges of the tarp are secured around the lower side edges and bottom edge of the trash opening of the CRC and the upper edges are secured to a tarping bar. The tarping bar is spring-biased to automatically swing upward when the CRC is moved away from a trash compactor site, in the process collecting any trash that spills from the trash opening and preventing trash from slipping from the CRC at the bottom of the tarp.
| 8
|
RELATED APPLICATIONS
This application claims priority to Taiwan Application Serial Number 96106508, filed Feb. 26, 2007, which is herein incorporated by reference.
BACKGROUND
1. Field of Invention
The present invention relates to a light emitting diode structure. More particularly, the present invention relates to a fixing structure of a light emitting diode and a method to assemble thereof.
2. Description of Related Art
The manufacturing technology of light emitting diodes is getting advanced recently, so that the light emitting efficiency for light emitting diodes is accordingly improved. The application of light emitting diode is based on its good characters, such as low operating temperature and low power assumption, etc. Therefore, the light emitting diode is getting more used in the light emitting field. For example, the light emitting diode is introduced to manufacture flashlights or automobile headlights.
The normal LED (Light Emitting Diode) structure consists of the die that is attached to the leadframe with an electrically conductive glue. Gold wire is used to connect the metal contact on the top of the LED die to the adjacent pin. Finally, the epoxy package is molded around the leadframe. Pins set of the leadframe extends outside the LED package. The pins can be inserted into holes in a circuit board, and be fixed on the circuit board by welding. The temperature for welding can be up to hundreds of Celsius degrees, which may be conducted to LED die and make the die burn down.
A prior structure and method of fixing a LED package on a circuit board without welding is provided. Referring to FIG. 1 , it illustrates a prior structure and method for fixing a LED package on a transferring board without welding. A LED package 10 includes a conductive leadframe 20 . The conductive leadframe 20 has fixing holes 30 . Corresponding to the locations of the fixing holes 30 , holes 50 are formed by protruding from the bottom surface to the upper surface of a transferring board 40 . After the holes 50 are formed, a fixing plate 60 is naturally formed from the protruding part of the holes 50 . Referring to FIG. 2 , it illustrates a prior structure of a LED package fixed on a transferring board without welding according to FIG. 1 . The fixing plate 60 passes through the fixing holes 30 , and the fixing plate 60 is bended inside out by using proper tools to fix the LED package 10 with the conductive leadframe 20 on the transferring board 40 . The transferring board 40 can be used as a circuit board to transmit current to LED die and a media for heat-dissipation at the same time.
The prior structure and method for fixing a LED package on a transferring board can prevent high temperature which is generated by welding from the assembly processes. However, it is not easy to form a uniform fixing plate 60 by protruding out from the holes 50 . Furthermore, the length of the fixing plate 60 is limited by the diameter of the holes 50 , which is generally equal to the radii of the fixing holes 30 . Referring to FIG. 3 , it illustrates a prior structure and method for a fixing plate passing through a fixing hole. The included angle ⊖ between the fixing plate 60 and the transferring board 40 herein is larger than 90 degrees, so that the fixing plate 60 can pass through the fixing hole 30 easily. However, the included angle ⊖ would make it difficult to bend the fixing plate 60 inside out for the following bending process. On the contrary, the fixing plate 60 with the included angle ⊖ would be bended inwards, it accordingly reduce the efficiency for fixing the LED package 10 and the conductive leadframe 20 on the transferring board 40 . Thus, for normally fixing the LED package 10 and the conductive leadframe 20 on the transferring board 40 , the included angle ⊖ between the fixing plate 60 and the fixing holes 30 should be less than 90 degrees. That is, the fixing plate 60 should be bended inside out. However, it will make the fixing plate 60 passing through the fixing holes 30 difficulty. Therefore, after the fixing plate 60 passing through the fixing holes 30 , it needs another process to deal with the included angle ⊖ between the fixing plate 60 and the transferring board 400 . It's really a dilemma.
However, one more process will result in increasing cost and decreasing yield rate, even downgrading manufacture automation process. It is not the manufacturers wanted. Thus, it is very important to provide a simple and non-welding structure and method for fixing the LED package and the conductive leadframe on the transferring board.
SUMMARY
It is therefore, the present invention to provide a structure of a light emitting diode and a method to assemble thereof, such that the light emitting diode can be fixed on a substrate. The substrate includes a circuit board, a transferring board or any kind of carrying board which can be used for fixing the light emitting diode thereon.
The light emitting diode structure comprises conductive frames electronically and respectively connecting to a packaged die of the light emitting diode. Each conductive frame comprises fixing holes, which pass through the conductive frame. The top radius of the fixing hole (output opening) is broader than the bottom radius of the fixing hole (input opening). Therefore, the fixing hole may have an inclined sidewall from top to bottom, or the fixing hole may have a ladder-shaped sidewall. In addition, the design that top and bottom radii of the fixing hole are broader than the middle radius of the fixing hole is also within the scope of the present invention. Besides, the fixing hole also can be set on the substrate. The bottom radius of the fixing hole is broader than the top radius of the fixing hole on the substrate. Therefore, the fixing hole may have an inclined sidewall from bottom to top, or the fixing hole may have a reversed-ladder shaped sidewall.
In one of the embodiments, a protrusive pillar is set on the substrate. The material of the protrusive pillar is a kind of conductive and expandable material, such as metal. The protrusive pillar can be a cylinder or hollow pillar. Generally, the hollow pillar is more deformable than the cylinder pillar. The cross-sectional area of the protrusive pillar can be equal to or smaller than the area of the bottom of the fixing hole or the cross-sectional area with the smallest radius of the fixing hole. Of course, the cross-sectional area of the protrusive pillar is not limited in the above-mentioned requirement. Any one of the protrusive pillar can pass through the input opening and protrude out of the output opening of the fixing hole is within the scope of the present invention. In addition, in the other embodiment, the protrusive pillar can be set on the surface of the conductive frame corresponding to the substrate, rather than set on the substrate.
In accordance with the foregoing disclosed structures of the present invention, a method for assembling a light emitting diode is provided. When a protrusive pillar passes through the fixing hole, the light emitting diode is not fixed yet. The protrusive pillar is then pressed by tools, and is deformed to hook the fixing hole. That is, the protrusive pillar fills the fixing holes, or the outer sidewalls of the protrusive pillar adhere to the inner inclined sidewalls of the fixing holes closely, so that the light emitting diode can be fixed on the substrate. The present method for assembling a light emitting diode without welding is easy and efficient. Therefore, the present invention provides a light emitting diode and a method to assemble thereof with low cost, high production rate and high yield rate.
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, figures, and appended claims.
It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,
FIG. 1 is a prior structure and method for fixing a packaged light emitting diode on a transferring board without welding;
FIG. 2 is a prior structure of a light emitting diode fixed on a transferring board without welding according to FIG. 1 ;
FIG. 3 is a prior structure and method for a fixing plate passing through a fixing hole;
FIG. 4 is a three-dimensional explosion diagram illustrating a structure of a light emitting diode according to first preferred embodiment of the present invention;
FIG. 5A is a cross-sectional view illustrating a structure and method for fixing a light emitting diode on a substrate according to first preferred embodiment of the present invention;
FIG. 5B is a cross-sectional view illustrating a structure of a light emitting diode fixed on a substrate according to first preferred embodiment of the present invention;
FIG. 6A is a cross-sectional view illustrating a structure and method for fixing a light emitting diode on a substrate according to second preferred embodiment of the present invention;
FIG. 6B is a cross-sectional view illustrating a structure of a light emitting diode fixed on a substrate according to second preferred embodiment of the present invention;
FIG. 7 is a cross-sectional view illustrating a structure of a light emitting diode fixed on a substrate according to third preferred embodiment of the present invention; and
FIG. 8 is a cross-sectional view illustrating a structure of a light emitting diode fixed on a substrate according to fourth preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a fixing structure of a light emitting diode, which uses riveting process rather than welding process for fixing the light emitting diode on a substrate to prevent the damage of the light emitting diode chip from high temperature of the welding process. Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Referring to FIG. 4 , it is a three-dimensional explosion diagram illustrating a structure of a light emitting diode according to first preferred embodiment of the present invention. As shown in FIG. 4 , a packaged light emitting diode 100 has a packaged die 102 and conductive frames 104 and 104 ′. The conductive frames 104 and 104 ′ electrically connect to the cathode and anode of the light emitting diode respectively (not shown). The conductive frames 104 and 104 ′ have fixing holes 106 and 106 ′ respectively.
Continue to FIG. 4 . Protrusive pillars 110 and 110 ′ are set on two substrates 108 and 108 ′ respectively. According to the first preferred embodiment of the present invention, the protrusive pillars 110 and 110 ′ can be hollow cylinders. The protrusive pillars 110 and 110 ′ are drawn to cylinders by pressing mold technic. Of course, the above-mentioned example is one of the embodiments of the present invention, the protrusive pillars 110 and 110 ′ are not limited to cylinders or hollow pillars, and are not limited to be formed in one piece (in an integral) with substrates 108 and 108 ′. A hollow or non-hollow pillar can be pressed into or screwed into the holes of the substrate.
Referring to FIG. 5A , it is a cross-sectional view illustrating a structure and method for fixing a light emitting diode on a substrate according to first preferred embodiment of the present invention. A light emitting diode 100 has a packaged die 102 and conductive frames 104 and 104 ′. The conductive frames 104 and 104 ′ electrically connect to the cathode and anode of packaged die 102 of the light emitting diode respectively (not shown). The conductive frames 104 and 104 ′ have fixing holes 106 and 106 ′ respectively. Protrusive pillars 110 and 110 ′ are set on the two substrates 108 and 108 ′ respectively. The protrusive pillars 110 and 110 ′ can be hollow pillars. As shown in FIG. 5A , the protrusive pillar 110 passes through the fixing hole 106 and combines with the fixing hole 106 , and the protrusive pillar 110 ′ passes through the fixing hole 106 ′ and combines with the fixing hole 106 ′.
Referring to FIG. 5B , it is a cross-sectional view illustrating a structure of a light emitting diode fixed on a substrate according to first preferred embodiment of the present invention. As shown in FIG. 5B , the protrusive pillars 110 and 110 ′ in FIG. 5A pass through the fixing hole 106 and combine with the fixing holes 106 and 106 ′ respectively. The protrusive pillars 110 and 110 ′ protrude out from the top surface of the substrates 108 and 108 ′ respectively. A pressing process then performs on the protrusive pillars 110 and 110 ′ by using proper tools, so that the protrusive pillars 110 and 110 ′ in FIG. 5A are deformed to become protrusive pillars 110 a and 110 a ′ in FIG. 5B and fill the fixing holes 106 and 106 ′. According to other embodiments of the present invention, the outer sidewalls of the protrusive pillars 110 a and 110 a ′ can adhere to the inner sidewalls of the fixing holes 106 and 106 ′ closely and not fill the fixing holes 106 and 106 ′. Generally, the height of the top surfaces of the protrusive pillars 110 a and 110 a ′ can be equal to, slightly higher than or slightly lower than the height of the top surfaces of the fixing holes 106 and 106 ′.
Please refer to FIG. 6A . It is a cross-sectional view illustrating a structure and method for fixing a light emitting diode on a substrate according to second preferred embodiment of the present invention. And referring to FIG. 6B , it is a cross-sectional view illustrating a structure of a light emitting diode fixed on a substrate according to second preferred embodiment of the present invention. The differences between the embodiment of FIGS. 6A and 6B and the embodiment of FIGS. 5A and 5B are that the shapes of fixing holes 206 and 206 ′ differ from the fixing holes 106 and 106 ′. As shown in FIG. 6A , the cross-sectional view of the fixing hole 206 is in a ladder shape. When protrusive pillars 210 and 210 ′ are inserted into the fixing holes 206 and 206 ′, a pressing process then performs on the protrusive pillars 210 and 210 ′ by using proper tools. The protrusive pillars 210 and 210 ′ in FIG. 6A are deformed into protrusive pillars 210 a and 210 a ′ in FIG. 6B and fill the fixing holes 206 and 206 ′. Of course, the outer sidewalls of the protrusive pillars 210 a and 210 a ′ may adhere to the inner sidewalls of the fixing holes 206 and 206 ′ closely and not fill the fixing holes 206 and 206 ′.
Please refer to both FIGS. 7 and 8 . FIG. 7 is a cross-sectional view illustrating a structure of a light emitting diode fixed on a substrate according to third preferred embodiment of the present invention. FIG. 8 is a cross-sectional view illustrating a structure of a light emitting diode fixed on a substrate according to fourth preferred embodiment of the present invention. As shown in FIG. 7 , the structure of the third preferred embodiment of the present invention in FIG. 7 is like the structure of the first preferred embodiment of the present invention in FIG. 5B . The only difference between FIG. 7 and FIG. 5B is that the locations of the protrusive pillars 310 a and 310 a ′ in FIG. 7 and the locations of the protrusive pillars 110 a and 110 a ′ in FIG. 5B are different. The protrusive pillars 110 a and 110 a ′ in FIG. 5B are set on the substrates 108 and 108 ′ respectively, while the protrusive pillars 310 a and 310 a ′ in FIG. 7 are set on the conductive frames 304 and 304 ′ respectively. In detail, the protrusive pillars 310 a and 310 a ′ in FIG. 7 are set on the surfaces of the conductive frames 304 and 304 ′ in correspondence with to the substrates 308 and 308 ′ respectively. Other characters of the third preferred embodiment of the present invention are the same with the first preferred embodiment of the present invention and can refer to the above description for the first preferred embodiment of the present invention.
Referring to FIG. 8 , the structure of the fourth preferred embodiment of the present invention in FIG. 8 is like the structure of the second preferred embodiment of the present invention in FIG. 6B . The only difference between FIG. 8 and FIG. 6B is that the locations of the protrusive pillars 410 a and 410 a ′ in FIG. 8 differ from the locations of the protrusive pillars 210 a and 210 a ′ in FIG. 6B . The protrusive pillars 210 a and 210 a ′ in FIG. 6B are set on the substrates 208 and 208 ′ respectively, while the protrusive pillars 410 a and 410 a ′ in FIG. 8 are set on the conductive frames 404 and 404 ′ respectively. In detail, the protrusive pillars 410 a and 410 a ′ in FIG. 8 are set on the surfaces of the conductive frames 404 and 404 ′ corresponding to the substrates 408 and 408 ′ respectively. Other characters of the fourth preferred embodiment of the present invention are the same with the second preferred embodiment of the present invention and can refer to the above description for the second preferred embodiment of the present invention.
In the above-mentioned embodiments of the present invention, the substrates can be used as circuit boards to transmit current to light emitting diode package. The protrusive pillars are added on the circuit board herein. The materials of the substrates can be metal, such as gold, silver, copper, aluminum, nickel, chromium, iron, or an alloy composed of the above-mentioned metals. The metal substrates not only can form a transmissible route for working current, but also can provide a heat-dissipation surface for the light emitting diode, so that the heat-dissipation efficiency is improved to prolong the lifetime of the light emitting diode.
According to the above-mentioned embodiments of the present invention, there are some advantages described as follows. The present structure of a light emitting diode and a method to assemble thereof is very easy and efficient, and does not need any welding process at all. Therefore, the present structure and method for fixing a LED package on a transferring board can reduce cost, and provide high production rate and high yield rate.
Although there are some embodiments have been disclosed above, they are not used to limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the structure and method of the present invention without departing from the scope or spirit of the invention. For example, the protrusive pillar can be pressed and deformed to fix on the top surface of the conductive frame or on the bottom surface of the substrate. A fixing hole with straight inner sidewall can be used at this time. In view of the foregoing, it is intended that the present invention covers modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
|
A structure of a light emitting diode is provided. The light emitting diode comprises a light emitting diode die; two conductive frames electronically and respectively connecting to the cathode and anode of the light emitting diode die, and two substrates. Each conductive frame has a fixing hole and each substrate has a protrusive pillar. The upper opening of the fixing hole is broader than the bottom opening. The protrusive pillar is inserted into the fixing hole and the shape of the protrusive pillar is deformed for fitting and binding with the fixing hole.
| 7
|
BACKGROUND OF THE INVENTION
This invention relates to plants for the processing of packets of cigarettes, pieces of soap or similar articles essentially of prismatic shape and, in particular, has as its subject electrical control and follow up gear for such plants.
DESCRIPTION OF THE PRIOR ART
The processing of packets of cigarettes or similar articles essentially of prismatic shape requires, as is known, machines for packeting the product, commonly called "packeting machines"; machines for overwrapping the packet containing the products, commonly called "overwrapping machines" or "cellophaning machines" since the overwrap is usually executed with a transparent material such as cellophane or with some other similar transparent material; and machines for forming a given number of overwrapped packets into cartons or parcels, commonly called "parcelling machines".
It is known to be easier to perform the operations of overwrapping the individual packets and of forming the parcels containing a number of the overwrapped packets than to carry out the operations pertinent to the formation of the individual packets. Thus the overwrapping or cellophaning machines, as well as the parcelling machines normally used in these plants for processing packets of cigarettes or similar articles essentially of prismatic shape, operate at a unit output speed greater than that of the packeting machines, and in each plant more than one packeting machine works in conjunction with one single overwrapping machine and with one single parcelling machine.
In order to render the individual packeting machines functionally independent of the overwrapping or cellophaning machine and of the parcelling machine relevant thereto a storage device or magazine is usually connected between the exits of the packeting machines and the entry point to the overwrapping or cellophaning machine. The purpose is to accumulate articles coming from the packeting machines and to supply the accumulated articles to the overwrapping or cellophaning machine at a rhythm compatible with the handling possibilities of the latter machine and with the output or infeed speed of the packeting machines. This is in conformity with the contents of U.S. Pat. No. 3,450,246 of the assignees hereof.
According to the aforementioned Patent, a multiple contact remote contactor connected to the mechanism for controlling the operational functions of the processing machines attends to the task of setting their handling rhythm to suit the running speed of the processing machines.
It is a known fact that in all production fields where a number of processing machines run in series, the second stage machines are always more prone to encountering operating problems than those with which the initial processing operations are carried out. This is because faults build up as the sequence of processing operations is gradually performed on the individual products. This obviously also happens in the plants for processing packets of cigarettes or similar articles essentially of prismatic shape. Thus the second stage machines provided, which in this particular case are the overwrapping machines and the parcelling machines, need to be fitted with a larger number of devices for controlling their various drive mechanisms prior to, during and after their respective periods of operation.
Drive mechanisms for these machines are normally provided with control devices, each of which generally consists of at least one electric contact movable in such a way that when a fault occurs or some difficulty is encountered, the processing machine to which the drive mechanism belongs is halted.
The moving contacts of the control device of the drive mechanisms are, furthermore, usually connected in series to one another so that when the fault or problem has been put right, normal operation can immediately be resumed.
This known technique satisfactorily answers the requirements for the running of the plant in accordance with the procedure outlined above. However, operational exigencies, connected above all with reliability and other guarantees make it desirable that, once the fault has been removed, or the difficulty overcome, the operator can restore operation of the machine previously halted because of the fault or difficulty.
SUMMARY OF THE INVENTION
The object of the present invention is, therefore, to make available electrical control and follow up gear in plants for processing packets of cigarettes or similar articles essentially of prismatic shape, with which the operator is able to put back into service the processing machines, once the causes of a stoppage have been remedied.
This is achieved by providing such a plant (in which there are one or more packeting machines, an overwrapping machine, a parcelling machine connected to the latter, a storage device or magazine interposed between the packeting machines and the overwrapping machine, a main multiple contact remote contactor connected to the individual electric motors used to power the packeting machines and the overwrapping machine through motor protection contactors and which also controls the satisfactory operation of the storage device or magazine, as well as a plurality of mechanisms in the overwrapping machine and the parcelling machine) with control switches interconnected in series, there being an operating relay provided with at least one moving contact and a manually operated pushbutton contact electrically connected in series to the moving contact of the relay, the operating coil of the relay being electrically shunt connected to the electrical connection between the moving relay contact and the manually operated pushbutton contact and being connected in series with the operating coil of the main multiple contact remote contactor through a pair of contacts belonging to the main multiple contact remote contactor, one of the contacts in the pair of contacts being normally open and the other, normally closed.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages will emerge more clearly from the following detailed description of a preferred but not the sole form of embodiment for the electrical control and follow up gear according to the invention. In the drawings
FIG. 1 shows, in a perspective view, a conventional plant for processing packets of cigarettes;
FIGS. 2 and 2a, to be joined along the line x--x, provide the wiring diagram for the plant, according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1 a conventional plant for processing packets of cigarettes has two packeting machines I and I', the output channels u and u' of which supply the packets of cigarettes to a vertical storage device or magazine A, for example, of the type described in the aforementioned Patent.
Magazine A is of the type that has two stacking columns C and C', respectively, one for the packeting machine I and one for the packeting machine I', and an output channel u" for supplying the packets of cigarettes to the overwrapping machine S, to which the parcelling machine Z is directly coupled.
In the wiring diagrams shown by way of an example in FIGS. 2 and 2a, the machines I, I', S and Z, like the device A, are depicted in block form with a thin line consisting of dots and dashes delimitating each.
The sole parts of the packeting machines I and I' visible are their electric drive motors MI and MI' along with their motor protection contactors r MI and r MI', the contacts of which are normally connected to the corresponding power supply lines to normally activate these motors.
In magazine A, each stacking column C and C' has a corresponding overflow microswitch AC and AC', respectively.
For the overwrapping machine S, its electric drive motor MS is shown along with the motor protection contactor r MS normally dis-connected thereto, whose contacts are connected from the power supply line, as shown, to normally deactivate this motor.
Connected to the packeting and overwrapping mahines I, I' and S there is a main contactor T which has contacts 5-6, 7-8 and 9-10 for controlling, through motor protection contactors r MI, r MI' and r MS the motors MI, MI" and MS. The main contactor T also governs the operation of the storage device A. This main contactor T is depicted, by way of an example, as having seven pairs of contacts T1-T2, T3-T4, T5-T6, T7-T8, T9-T10, T11-T12 and T13-T14. The normally open pair T1-T2 serves to keep the coil of contactor T self-excited through a plurality of microswitches connected to mechanisms of the overwrapping machine S and the parcelling machine Z, as will be seen better in due course. The normally closed pairs T11-T12 and T13-T14 are a part of the follow up contacts of the storage device or magazine A, other details of which are described in the aforementioned Patent. The normally open pairs T5-T6 and T9-T10 serve to keep drive motors Mi, Mi', M4 operating so long as the contactor T is energized.
The mechanisms with which the overwrapping machine S is provided comprise assemblies a and b for supplying from a reel, in known fashion, a strip of material 1 such as cellophane or a similar transparent material, in sheet form for wrapping around the outside of the individual packets. In FIG. 2a the assemblies a, b of machine S' are shown as Sa, Sb, respectively; similarly other assemblies c to o are shown with suitable prefixes. The machine S also has an assembly c for supplying, again from a reel, what is known as the "tear strip" 12 incorporated in the wrap formed around the outside of the individual packets. It also has an assembly d which, as will be seen better later on in this text, serves as a movable protection guard; an assembly e connected to the means that operate the machine itself; an assembly f for supplying the individual packets to the machine; and, finally, an assembly g for the supplementary supply of packets to replace others previously rejected.
The parcelling machine Z has assemblies h and i for supplying from a reel 35, material 36 in sheet form with which to parcel up a given number of overwrapped packets; an assembly l for supplying, again for a reel, what is known as the "tear strip" 45 incorporated in the material used to parcel up the packets; an assembly m connected to the means that operate the machine itself; an assembly n for checking the position of the overwrapped packets at the time they are being supplied for the formation of the parcel; and, finally, an assembly o for checking the number of overwrapped packets that go to make up the parcel.
In the assembly a, the strip 1 of cellophane or other similar transparent overwrapping material to be supplied passes between two rollers 2 and 3. Resting, in order to act as a feeler, on that part of the strip 1 located between the said rollers 2 and 3, there is a cylindrical member 4 carried loosely on one end of a lever 5 pivotally mounted to oscillate around a pin 6, the other extremity 5' of which works in conjunction with the mechanism for tripping a microswitch 7 provided with a moving contact 1 and two fixed changeover contacts 2-3. Should there be a break in the supply of the strip of material 1 from the reel, or should the reel come to an end, the lever 5 rotates around the pivot 6 and its tail end 5' is carried into a position whereby it touches the tripping mechanism of the microswitch 7 which causes the moving contact 1 to move from its normal position 1-2 to position 1-3.
The strip 1 is, furthermore, made to pass into the assembly b, between the fixed guide 8 and the movable guide 9, so as to adopt an operating position as shown in FIG. 2a in which it is held firm by a clamp bar 10 which can be operated manually or else to adopt a non-operative position. The strip 1 thus passes between the guides 8 and 9, and should it accidentally corrugate while the machine is in motion, it touches against the tripping mechanism of a microswitch 11 whose moving contact 1 then changes from its normal position 1-2 to the position 1-3.
The tear strip 12 supplied in the assembly c passes between two rollers 13 and 14. Resting, in order to act as a feeler, on that part of the tear strip 12 located between the rollers 13 and 14, there is a cylindrical member 15 carried loosely on one end of a lever 16 pivotally mounted to oscillate around a pin 17, the other extremity 16' of which works in conjunction with the mechanism for tripping a microswitch 18 provided with a moving contact 1 and two fixed changeover contacts 2-3. Should there be a break in the supply of the tear strip 12 from the supply reel thereof, or should the reel come to an end, the lever 16 rotates around the pivot 17 and its tail end 16' is carried into a position whereby it touches the tripping mechanism of the microswitch 18 which causes the moving contact 1 to move from its normal position 1-2 to position 1-3.
The assembly d consists essentially of a panel 19 rotatably mounted on hinges 20 in front of a compartment for assembly a, b and/or c. The panel is made of a transparent material and it serves as a guard for the front part of the machine. When, for any reason at all connected with the operation of the machine, the operator opens the panel, a feeler member 21 integral with the panel operates the tripping mechanism of a microswitch 22 which causes the moving contact 1 to move from its normal position 1-2 to position 1-3.
The assembly e belonging to the overwrapping machine comprises a drive pulley 23 which, through a belt 24, drives a speed reduction pulley 25, to the shaft of which is keyed, so that it can slide elastically in an axial direction, a transmission gear 26. The gear 26 is rotatably mated with the pulley 25 through a drive pin 27. In the event of an accidental increase in the torque between the pulley 25 and the gear 26, due, for example, to a blockage on the part of the packets, the gear 26 is displaced axially, against an elastic action, in such a way as to touch the tripping mechanism of a microswitch 28 which causes the moving contact 1 thereof to move from its normal position 1-2 to position 1-3.
The assembly f comprises a pusher member 29 which, in the event of the individual packets being fed to the overwrapping machine S causing a blockage, touches the tripping mechanism of a microswitch 30 which causes its moving contact 1 to move from its normal position 1-2 to position 1-3.
The assembly g is provided to supply replacement packets if there are rejects in the packets being supplied for the formation of a parcel. A rotatable feeder plate 31 passes beneath a supplementary chute 32 and in the event that faulty packets have been rejected, plate 31 drags packets dropped from chute 31 into the places where packets are missing. The hopper 32 is provided with a feeler device 33 for detecting the presence of packets within the chute.
This feeler device works in conjunction with the tripping mechanism of a microswitch 34. If the chute is empty the microswitch 34 is made to trip and this causes its moving contact 1 to move from its normal position 1-2 to position 1-3.
The assembly h provided to supply carton material with which to parcel up a given number of overwrapped packets comprises a reel 35 from which a parcelling strip 36 of such material is made to pass over a surface 37 below a feeler device 38 which oscillates around a shaft 39 carried by supports 40 secured to the surface 37. In this surface there is a recess 41 into which the feeler member 38 drops in the event of an interruption in the infeed of the strip 36 or of its coming to an end. In this way the feeler device brings about the tripping of a microswitch 42 which causes the moving contact 1 of the latter to move from its normal position 1-2 to position 1-3.
The strip of material 36 is, furthermore, made to pass into the assembly i, between a roller 43 and the tripping mechanism of a microswitch 44. If it should happen that the strip 36 accidentally corrugates, the tripping mechanism of the microswitch 44 is displaced and thus the moving contact 1 of the microswitch moves from its normal position 1-2 to position 1-3.
A tear strip 45 for the carton or parcel, in the assembly l, passes between two rollers 46 and 47. Resting, in order to act as a feeler, on that part of the tear strip located between the rollers 46 and 47, there is an arm 48 of a member 49 with two arms, which member is rotatably mounted so that it oscillates around a pin 50 carried by a fixed support 51.
The other arm 52 of the member 49 works in conjunction with the mechanism for tripping a microswitch 53 provided with a moving contact 1 and two fixed changeover contacts 2-3. Should there be a break in the supply of the tear strip 45 from the supply reel thereof or should that reel come to an end, the oscillating member 49 rotates around the pivot 50 and its arm 52 is carried into a position whereby it touches the tripping mechanism of the microswitch 53 which causes is moving contact 1 to move from its normal position 1-2 to position 1-3.
The assembly m on the parcelling machine Z takes its drive from the aforementioned drive pulley 23 of the overwrapping machine S. For this purpose the shaft 25' of the corresponding reduction pulley 25 (not depicted in FIG. 1) has a transmission gear 54 provided similarly to the transmission gear 26 previously described for the assembly e.
In the event of an accidental increase in the torque between reduction pulley 25 and the gear 54, due, for example, to blockage of packets supplied for the formation and wrapping of a parcel, the gear 54 is displaced axially, against an elastic action, in such a way as to touch the tripping mechanism of a microswitch 55 which causes the moving contact 1 of the microswitch 55 to move from its normal position 1-2 to position 1-3.
The assembly n comprises a brush device 56 for checking the position of the overwrapped packets while they are being infed for the formation of the parcel.
One part of the brush device 56 is in the form of a tail 56' and this is intended to work in conjunction with the tripping mechanism of a microswitch 57 provided with a moving contact 1 and two fixed changeover contacts 2-3. In the event of the packets infed getting blocked, the brush device 56 is raised as shown in FIG. 2a and the tail 56' releases the tripping mechanism of the microswitch 57, the moving contact 1 of which moves from its normal position 1-2 to position 1-3.
The assembly o provided to check the number of overwrapped packets destined to form the parcel, comprises a brush device 58 provided with a lateral protrusion 59.
Should there be less than the predetermined number of packets required to form the parcel, that is to say, should, for example, a packet be missing in the infeed channel 60, the brush device 58 is lowered and its protrusion 59 comes into contact with the tripping mechanism of a microswitch 61 which causes its moving contact 1 to move from its normal position 1-2 to position 1-3.
Finally, at 62 there is a cam driven by overwrapping machine motor MS (FIG. 2) to cyclically cause a microswitch 63 to be tripped and its moving contact 1 to move from its normal position 1-2 to position 1-3; at r there is a relay provided with a normally open moving contact r'; and on a line 64 shunted from a 24 V supply transformer Y, a manually operated microswitch P with normally open contacts 1-2 is connected in series with the microswitch 63 and with the operating coil of the aforementioned relay r.
As can be seen from the electro-mechanical diagram in FIGS. 2 and 2a, the microswitches of the above mentioned assemblies a to o are all interconnected in series with one another and with the moving contact r' of the relay r, the operating coil of the relay r, and the contacts T1-T2 and T3-T4 of the contactor T, the latter being paralleled with each other.
As previously stated, the storage device A comprises two vertical columns C and C'. Each of the columns is connected to a feeler device, 65 and 65', respectively, which work in conjunction with a corresponding microswitch, AC and AC', respectively, provided with a moving contact 1 and two fixed changeover contacts 2-3.
These feeler devices are provided to signal the filling of the storage columns. Once the level of the packets contained therein has reached the height of the corresponding feeler device, through the microswitch with which the feeler device works, the respective packeting machine I or I' is halted.
The operation of the plant with the electrical control and follow up gear in question takes place in the following way:
When the overwrapping machine S has been set ready to operate by manually depressing the pushbutton of the microswitch P, then, in phase with the closing of the microswitch 63 by the cyclic cam 62, the contactor T and the relay r are excited. Through the contacts T1-T2 and r1, respectively, they thereafter remain self-excited, as will be clear from FIG. 2. All the series connected microswitches of the assemblies a to o are closed under normal operating conditions of these assemblies (see FIG. 2a), just as is true, after depression of pushbutton P, as to the contact r1 of the relay r which is also connected in series with them (see FIG. 2).
Should any of the accidental conditions described with reference to the assemblies a to o occur, the contactor T and the relay r are de-energized through the opening of the corresponding miroswitch and thus the overwrapping machine S and, consequently, also the parcelling machine Z mechanically coupled therewith come to a halt. At the same time through the contacts T11-T12 and T13-T14 of the contactor T, the storage device A is put into service; it then operates in the way described in the above mentioned Patent.
Storage device A then stores packets at C or C', and if the overwrapping machine S continues to be out of operation, the stored packets rise to the level of the feeler device 65 or 65', the corresponding microswitch AC or AC' is tripped, and thus the displacement of its moving contact from position 1-2 to position 1-3 also causes the respective packeting machine I or I' to cease running.
Once the cause of the stoppage of the machines S and Z has been remedied, to set the machines going again, the pushbutton of the microswitch P, as previously seen, has to be depressed in order to return the plant to its original operating condition.
|
Control for a system of machines for packeting, overwrapping and parcelling packets of cigarettes or similar articles of prismatic shape, so that in the event of a machine dropping out of operation, the operator be able to set it going again after having first overcome the causes that brought about the stoppage. The control is effected through a main multiple contact remote contactor connected to the individual motors of the individual machines. The excitation coil of the remote contactor is connected in series with the operating coil of a main relay actuated by a manual pushbutton which serves to manually reset the plant in operation after an outage.
| 1
|
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to an edge guard of the type applied to the trailing edges of automobile doors.
The advantages of door edge guards are recognized by the automobile industry. Edge guards provide functional, decorative and protective aspects when applied to the trailing edges of automobile doors or the edges of other swinging closures.
The original equipment automobile industry has never approved of strictly plastic edge guards but rather has insisted upon metal edge guards because of their superior characteristics. In order however to provide certain styling features, it has been deemed desirable to provide other than a metallic appearance to the exposed exterior of an installed door edge guard.
Many of applicant's inventions, as evidenced by the following patents, relate to insulated door edge guards: U.S. Pat. Nos. 4,259,812, 4,338,148, 4,379,376, 4,316,348, 4,365,450, 4,379,377, 4,334,700, 4,377,056, 4,387,125.
Applicant also has pending applications directed to the same general subject.
One procedure for making an insulated door edge guard comprises laminating a sheet of plastic to a sheet of metal, then slitting the laminated sheets into desired widths and roll-forming the strips into desired U-shaped cross section. One part of the procedure involves the formation of beads on the ends of the legs. In an insulated metal edge guard where the exterior of the edge guard is covered by insulation, the inward turning of the beads will result in insulation being disposed between the metal of the edge guard and the door edge at the points of force application when the edge guard is mounted on the door.
The usage of self-retaining edge guards is deemed desirable but depending upon painting procedures which are used on automobiles the insulated metal edge guards may not exhibit the expected self-retention characteristics on a door edge.
The present invention relates to an edge guard which provides a solution to the inability of an edge guard to exhibit the expected self-retention characteristics on particular types of painted surfaces. The invention arises through the judicious selection of material for the metal edge guard so that a desired retention characteristic is obtained for different types of paint procedures on door edges.
By way of example reference is made to a water based paint procedure and a solvent based paint procedure. For a given door, the differences in these two procedures may result in a situation where an edge guard is self-retaining on one type of painted surface but exhibits less than expected self-retention characteristics on the other type of painted surface.
The invention will be described in detail with reference to the accompanying drawings, the ensuing description, and the appended claims. The disclosure is of a preferred embodiment according to the best mode contemplated at the present time in carrying out the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial side elevational view of an automobile containing door edge guards embodying principles of the present invention.
FIG. 2 is a cross sectional view taken in the direction of arrows 2--2 in FIG. 1 and enlarged.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an automobile 10 having front and rear doors 12 and 14 containing door edge guards embodying principles of the present invention. The door edge guards are identified by the reference numerals 16, 18 and by way of example are shown to be fully coextensive in length with the trailing edges of the respective doors to which they are applied. However, the door edge guards need not necessarily be of the same length as the trailing edges of the doors and therefore the drawing illustration of FIG. 1 should be considered to be merely representative.
FIG. 2 illustrates the edge guard cross section which is representative throughout the length of the edge guard. The edge guard comprises an insulated metal structure comprising a metal edge guard member 20 and an insulating liner 22. The edge guard metal channel has a generally semi-circular base 24 with legs 26 and 28 extending away from the generally semi-circular base. The distal ends of the legs are provided with beads 30 and 32 formed by fully reverse turning the distal ends of the legs back onto themselves in the inward direction. The insulating liner 22 covers the exterior of the U-shaped cross section and extends around the rounded ends of the beads so that the beads are covered with insulation at the points 34, 36 where the self-retention pressure is applied by the metal edge guard channel to opposite sides of the door. Hence at the points of retention force application, the metal of channel 20 is insulated from the door edge.
One procedure for fabricating the edge guard comprises laminating a flat sheet of plastic to one surface of a metal strip and then slitting the strip to an appropriate width. The laminated strip is then formed to the illustrated cross section through roll-forming procedures. This yields the finished edge guard construction in which the plastic laminate lines the exterior of the edge guard so as to provide a desired outward appearance when the edge guard is installed on the door edge. Yet at the same time, the formation of the inwardly directed beads results in insulation being disposed between the metal channel and the door edge at the points of force application. Moreover, where the insulation is a grained plastic film, it is preferred to orient the grain such that the length of the grain runs lengthwise of the edge guard. This will result in the forces exerted on the beads during installation of the edge guard on the door being across the grain, rather than with the grain, and this reduces the tendency to tear the film from the metal.
Because it is the intention to have the edge guard self-retaining on the door edge without the use of separate adhesives or other procedures, the metal channel must bear certain characteristics. Heretofore, stainless steel has been one of the preferred materials for exerting suitable self-retention force for the installed edge guard yet one which can be subjected to the required fabrication and installation procedures. However, because the metal exterior is covered by insulation, it is more economical to use a less expensive material such as aluminum.
As explained earlier in this application, it was found that on certain doors, edge guards would not exhibit the desired self-retention characteristics while on certain other doors there was no departure from the desired self-retention characteristics. The source of this problem was traced to different types of painting procedures applied by different plants to the same model of door. These two procedures are a solvent-based procedure and a water-based procedure. On one type of paint, the edge guards were satisfactorily self-retained while on the other, less than desired retention force had a tendency to occur, resulting in loosening of the edge guards or inability to be installed and retained on the door edge. Efforts to dimensionally redesign the edge guard in order to obtain a construction which exhibited satisfactory characteristics for both types of painted doors proved unsuccessful. However, further diligent research and investigation resulted in the selection of a new material for the metal edge guard channel which was able to solve the problem. The material involved and which is now used in the manufacture of the edge guards is 5052 H-33 aluminum. This material exhibits particular hardness and temper characteristics which enable edge guards so constructed to be installed and satisfactorily retained on both types of painted doors, yet enabling the laminated material to be formed to the desired cross sectional shape to achieve the desired appearance characteristics with the economy of aluminum rather than stainless steel.
While a preferred embodiment of the invention has been disclosed, it will be appreciated that principles are applicable to other embodiments.
|
An edge guard comprises a generally U-shaped cross section with insulated beads formed at the outer marginal edges of the legs which apply the retention force to the door edge. The invention provides a construction which is self-retaining on different types of surfaces. The metallic material of the edge guard is 5052 H-23 aluminum.
| 1
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a control scheme. More particularly the present invention relates to a method and apparatus for reducing a shaft power required to drive a multistage turbocompressor by selectively manipulating throttle valves at the compressor stages' inlets while simultaneously protecting the compressor stages from surge.
[0004] 2. Background Art
[0005] During some modes of operation a load imposed by the process on a single- or multistage compressor may exceed a maximum power available from the driver or drivers. Compressor shutdown may be required to avoid damage to the driver. Shutdown is to be avoided due to its inherent production loss.
[0006] A known method to avoid shutdown while still protecting the driver from damage reduces the load on the train by throttling the inlet flow using an inlet throttle valve on each stage of compression.
[0007] The present-day scheme of protection calls for reducing the opening of the inlet throttle valves, when present. The anticipated result is a reduction of flow through each of the compressor stages, and a consequent reduction in power consumed by compressor train.
[0008] Compressor surge is an unstable operating condition that is to be avoided. Modern control systems provide antisurge protection by calculating an operating point of the compressor and determining a proximity of the operating point to the compressor's surge limit. Antisurge control is explained in the Compressor Controls Series 5 Antisurge Control Application Manual, Publication UM5411 rev. 2.8.0 Dec. 2007, herein incorporated in its entirety by reference.
[0009] A surge control line is defined by providing a safety margin to the surge limit. When the compressor's operating point approaches the surge control line, a recycle, or antisurge, valve plumbed in parallel with the compressor is opened to provide sufficient flow to the compressor to keep it safe from surge.
[0010] Throttling the inlet flow of a turbocompressor stage operating at or near its surge control line causes that stage's operating point to be driven nearer to surge. When the antisurge control system is actively manipulating the antisurge valve to protect its compressor stage from surge, closing the inlet throttling valve will cause the control system to increase the opening of the antisurge valve to compensate for the reduction of the inlet flow rate. Thus no reduction of shaft power is realized.
[0011] There is, therefore, a need for an improved control strategy for the startup of turbocompressors to reduce the loading of the compressor while maintaining the compressor flow out of the unstable, surge region.
BRIEF SUMMARY OF THE INVENTION
[0012] An object of the present invention is to provide a method and apparatus for effectively reducing the shaft power required to drive a multistage turbocompressor. It is a further object of the present invention to provide this reduction in shaft power while maintaining the compressor train in a stable operating condition.
[0013] The instant invention uses compressor driver power limiting to simultaneously close inlet throttling valves in the train to reduce the overall driver power consumption by the compressor train. All inlet valves are closed in this manner except those valves on compressor stages operating nearer surge than a predetermined distance. Therefore, inlet throttling valves are not closed past the point where the compressor's operating point is at that predetermined distance from surge.
[0014] The instant invention can be used for to control any compressor train with one or more stages of compression, where the shaft load must be limited to avoid shutdown, and where suction throttling valves are available. For the purposes of this document, including the claims, the term compressor train is hereby defined as one or more turbocompressors or turbocompressor stages on a single shaft. Shaft power may be provided by one or more drivers such as gas or steam turbines, or electric motors.
[0015] The novel features believed to be characteristic of this invention, both as to its organization and method of operation together with further objectives and advantages thereto, will be better understood from the following description considered in connection with the accompanying drawings in which a presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood however, that the drawings and examples are for the purpose of illustration and description only, and not intended in any way as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0016] FIG. 1 is a schematic of a compressor train wherein each stage of compression is outfitted with an inlet throttling valve;
[0017] FIG. 2 is a schematic of a compressor train and a control system for the same;
[0018] FIG. 3 is a representative compressor performance map in (Q,H p ) coordinates;
[0019] FIG. 4 is a representative compressor performance map in (Q,{dot over (W)}) coordinates;
[0020] FIG. 5 is a flow diagram illustrating a logic of the control scheme of the instant invention;
[0021] FIG. 6 is a schematic of a compressor train driven by a gas turbine driver;
[0022] FIG. 7 is a detail of an overpower query using electric motor current or power as the criterion for detecting overpowering;
[0023] FIG. 8 is a detail of an overpower query using steam turbine steam flow rate as the criterion for detecting overpowering;
[0024] FIG. 9 is a detail of an overpower query using gas turbine exhaust gas temperature as the criterion for detecting overpowering; and
[0025] FIG. 10 is a detail of an overpower query using shaft torque as the criterion for detecting overpowering.
DETAILED DESCRIPTION OF THE INVENTION
[0026] A three-stage compressor train is shown, schematically, in FIG. 1 . The present invention is useful on compressor trains of any number of compressor stages 115 a - 115 c , and is, therefore, not limited to the three-stage train shown in FIG. 1 . Shaft power to drive the compressors 115 a - 115 c is, in this case, provided by a steam turbine 110 and an electric motor 120 .
[0027] Instrumentation for monitoring and control comprises flow meter transmitters 125 a - 125 c , suction pressure transmitters 130 a - 130 c , and discharge pressure transmitters 135 a - 135 c for each stage of compression 115 a - 115 c.
[0028] The drivers are also instrumented: the electric motor 120 is fitted with an electric current or power transmitter 155 while the steam flow rate into the steam turbine 110 is measured by the steam flow transmitter 160 .
[0029] In FIG. 6 , a gas turbine 610 is shown as the driver of the compressor train. Instrumentation on the gas turbine might include an Exhaust Gas Temperature (EGT) transmitter 620 and a shaft torque meter 630 .
[0030] Each compressor stage 115 a - 115 c is fitted with an inlet throttling valve 140 a - 140 c by which performance or capacity control is effected and load balancing between the individual compressor stages 115 a - 115 c is carried out.
[0031] Adequate flow through the compressor stages 115 a - 115 c is provided for antisurge control by manipulating the antisurge valves 145 a - 145 c.
[0032] As with many refrigeration compressors, sidestreams 150 a - 150 b are integral to the compression system.
[0033] In FIG. 2 , the same compressor train as illustrated in FIG. 1 is shown with a control system. Some of the reference numbers shown in FIG. 1 are not shown in FIG. 2 for clarity. A typical control system comprises antisurge controllers 210 a - 210 c and performance controllers 220 a - 220 c for each stage of compression 115 a - 115 c , and a load sharing controller 230 .
[0034] Into each antisurge controller 210 a - 210 c is inputted signals representing: a flow rate from the flow meter transmitter 125 a - 125 c , a suction pressure from the suction pressure transmitter 130 a - 130 c , and a discharge pressure from the suction pressure transmitter 135 a - 135 c . Other signals may also be provided and the present invention is not limited to any particular set of input signals to the antisurge controllers. The output signal from each of the antisurge controllers 210 a - 210 c is a signal to manipulate the antisurge valve 145 a - 145 c.
[0035] The performance controllers 220 a - 220 c manipulate the inlet throttling valves 140 a - 140 c based on a load sharing control scheme such as those disclosed in U.S. Pat. No. 5,743,715, hereby incorporated by reference. The load sharing controller 230 communicates with the performance controllers 220 a - 220 c , causing them to manipulate their respective inlet throttling valves 140 a - 140 c to maintain a process variable at a predetermined set point.
[0036] Note that all individual controllers 210 a - 210 c , 220 a - 220 c , 230 are able to communication one with another over a hardwired or wireless network represented by dash-dot-dot lines in FIG. 2 . Therefore, when a driver is overpowered—for instance: the electric motor current (or power) exceeds a predetermined upper threshold—the load sharing controller 230 is able to detect that event by comparing the signal from the current (or power) transmitter 155 to the predetermined threshold, and is then able to signal the performance controllers 220 a - 220 c to cause their respective inlet throttling valves 140 a - 140 c to close. Additionally, the performance controllers 220 a - 220 c can receive information from the antisurge controllers 210 a - 210 c regarding the position of their respective compressor's operating points. With this information, each performance controller 220 a - 220 c will determine if and how much to close the inlet throttling valve 140 a - 140 c to simultaneously reduce the electric motor's load and safeguard the compressors 115 a - 115 c from surge.
[0037] A typical compressor performance map in polytropic head vs. Q coordinates is shown in FIG. 3 . Here, Q is volumetric flow rate—usually measured at the inlet. The map of FIG. 3 comprises curves of constant rotational speed 310 a - 310 d , a surge limit 320 , a surge control line 330 , and a power limiting curve 340 . The surge limit 320 is the boundary between the surge region and the stable operating region, usually simply referred to as the operating region. The surge control line 330 is a curve set apart from the surge limit 320 by a safety margin, sometimes referred to as the surge margin. The power limiting curve 340 is a curve set apart from the surge control line 330 by a predetermined distance. When the driver is overpowered, the inlet throttling valve 140 a - 140 c of each turbocompressor 115 a - 115 c is ramped closed to the point where the compressor's operating point reaches the power limiting curve 340 . In this fashion, the antisurge valve 145 a - 145 c of that particular turbocompressor stage 115 a - 115 c is not forced to open to protect the compressor 115 a - 115 c from surge.
[0038] In FIG. 4 , another compressor performance map is shown. Here, the performance curves are in shaft power vs. Q coordinates. Each curve 410 a - 410 d is, again, a line of constant rotational speed. It is clear from the curves of shaft power 410 a - 410 e , at a given rotational speed, the required shaft power decreases as the compressor's operating point moves toward the surge limit 210 .
[0039] In FIG. 5 , the control algorithm of the present invention is illustrated in a flow diagram. This diagram may be considered the programmed algorithm in the control system 210 a - 210 c , 220 a - 220 c , 230 shown in FIG. 2 . Because the individual controllers 210 a - 210 c , 220 a - 220 c , 230 are able to communicate with one another, any part of the algorithm shown in FIG. 5 may be executed in any particular controller 210 a - 210 c , 220 a - 220 c , 230 . Necessary inputs and outputs to each controller function are communicated via the inter-controller communication links.
[0040] As is well known in the art, in the usual course of operation, some aspect of performance or capacity control is carried out on the compressors 115 a - 115 c via the manipulation of the inlet throttling valves 140 a - 140 c . This usual mode of operation is indicated in the top block 510 of FIG. 5 . The control system 210 a - 210 c , 220 a - 220 c , 230 monitors some aspect or aspects of the driver 110 , 120 , 610 to determine if the driver 110 , 120 , 610 is overpowered. Aspects that may be monitored include, but are not limited to: electric motor current, electric motor power, gas turbine exhaust gas temperature, shaft torque, and steam turbine steam flow rate.
[0041] When the monitored aspect, or one of the monitored aspects, exceeds a threshold (see FIGS. 7-10 ), the driver 110 , 120 , 610 is deemed overpowered, as indicated in the first query block 520 . When the query proves true, that is, the driver 110 , 120 , 610 is overpowered, the algorithm calls for a query of the control system 210 a - 210 c , 220 a - 220 c , 230 , in the second query block 530 , to determine if each compressor's operating point is to the right of the power limiting curve 340 —that is, if it is safe to close the inlet throttling valve 140 a - 140 c . If the result of this query 530 is false, control of the inlet throttling valve 140 a - 140 c remains with the performance controller in block 510 . Whenever the query 530 is true, the opening of the respective throttling valve 140 a - 140 c is reduced in block 540 while continuously or periodically checking if the driver 110 , 120 , 610 remains overpowered and, if so, if it remains safe to close the inlet throttling valve 140 a - 140 c further. Note that the function illustrated in FIG. 5 is carried out for each of the turbocompressors 115 a - 115 c in the compressor train that has an inlet throttling valve.
[0042] FIGS. 7-10 clarify the first query block 520 in FIG. 5 . In FIG. 7 , the criterion used for determining if the electric motor 120 is overpowered is motor current or motor power, according to the signal received from the current or power transmitter 155 . The signal received from the transmitter 155 is compared to a threshold value for that signal in a query block 710 to make the determination as to whether or not the driver is overpowered.
[0043] In FIG. 8 , the criterion used for determining if the steam turbine 110 is overpowered is steam flow rate, according to the signal received from the steam flow rate transmitter 160 . The signal received from the transmitter 160 is compared to a threshold value for that signal in a query block 710 to make the determination as to whether or not the driver is overpowered.
[0044] In FIG. 9 , the criterion used for determining if the gas turbine 610 is overpowered is the exhaust gas temperature, according to the signal received from the exhaust gas temperature transmitter 620 . The signal received from the transmitter 620 is compared to a threshold value for that signal in a query block 710 to make the determination as to whether or not the driver is overpowered.
[0045] In FIG. 10 , the criterion used for determining if the driver 110 , 120 , 610 is overpowered is the shaft torque, according to the signal received from the torque transmitter 630 . The signal received from the transmitter 630 is compared to a threshold value for that signal in a query block 710 to make the determination as to whether or not the driver is overpowered.
[0046] The above embodiment is the preferred embodiment, but this invention is not limited thereto, nor to the figures and examples given above. It is, therefore, apparent that many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
|
A control method and apparatus for simultaneously protecting a compression system from driver overpowering and turbocompressor surge. When overpowering is detected, flow rate through the each compressor in the turbocompressor train is reduced by closing an inlet throttling valve at the inlet of each respective compressor stage unless a compressor operating point is sufficiently near surge. In this latter case, the inlet throttling valve is not closed. In this way, overall flow rate through the compressor train is reduced while maintaining adequate flow through compromised stages to avoid surge.
| 5
|
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of the prior filed, co-pending provisional applications Ser. No. 61/347,493, filed May 24, 2010 and Ser. No. 61/441,835, filed Feb. 11, 2011.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to gift cards and more particularly to a device for suspending or hanging a gift card from a gift card holder or greeting card.
[0003] Transaction cards, stored value cards, or gift cards as they are commonly called based upon their intended use, have become popular gifts. Gift cards typically comprise a stored value card whereby a certain cash equivalent value is encoded upon a magnet strip applied to the surface of the card. This stored value may be determined by the vendor prior to packaging and display for sale or may be selected at the point of sale by the purchaser and loaded by the cashier using a magnetic card reader/writer. In some cases, the cash value is not stored upon the card itself but is associated with a card identification number and stored in a remote database. Alternatively, gift cards may be provided with a bar code or account number that links the card to a system account in which a record is stored associated with a monetary value. While popular, gift cards are typically provided with a generic and impersonal design, typically identifying only the associated merchant for which the card may be used to purchase merchandise, and therefore are not personalized in view of the intended recipient.
BRIEF DESCRIPTION OF THE INVENTION
[0004] The purpose of this invention is to provide a means for hanging or suspending a transaction card, such as a conventional gift card, mounted on a backer card or panel from a greeting card or gift card holder. The gift card holder typically includes indicia for indicating both the name of the sender and recipient of the gift card, decorations of various styles or themes, and one or more slots for inserting a gift card into the holder or other means such as adhesive for holding the gift card to or within the hold structure. The holder may be mounted on a first backer panel that includes a peg hole for hanging the first backer panel and attached holder upon a display rack peg. The holder may include electronics for recording and playing sound such as music and/or a message from the gift giver. The electronics may include a sound speaker, a power source such as one or more commonly available watch batteries, a control circuit, a memory chip for storing sound recordings, and record and playback buttons.
[0005] The gift card is typically mounted on a second backer panel that is also provided with a peg hole for either hanging the second backer panel upon a display rack peg or for use within the system disclosed herein. The gift card may be disposed upon the second backer panel so that the magnetic strip of the gift card projects below the lower margin of the second backer panel, or the second backer panel may be provided with a fold line, either structure thereby enabling the gift card magnetic strip to be scanned at the point of sale. Alternatively, in the case of a gift card provided with a bar code or other optically scannable indicia on the back of the gift card, the second backer panel may include a window in alignment with the scannable indicia so that the indicia may be scanned without removing the gift card from the second backer panel.
[0006] A strip or tab of acetate, plastic, paper or the like projecting from the lower margin of the first backer panel is looped through the peg hole of the second backer panel and then affixed via adhesive or equivalent means (e.g. hook and loop fasteners) to a surface of the first backer panel to form a loop by which the second backer panel and attached gift card may be hung or suspended from the first backer panel and/or gift card holder.
[0007] After purchase of the assembly comprising the gift card holder and gift card, the gift card may be removed from the second backer panel and installed within or upon the gift card holder. In certain embodiments, the gift card holder may then be detached from the first backer panel prior to giving the gift card holder bearing the gift card to a gift recipient.
[0008] An embodiment of a transaction card hanger system includes a transaction card assembly attached to a transaction card holder assembly by suspending the card assembly from the holder assembly via a looped tab secured at either end to the holder assembly. The transaction card assembly may include a panel bearing an attached transaction card. The transaction card holder assembly may include a panel bearing a transaction card holder.
[0009] Another embodiment of a transaction card hanger system includes a transaction card holder assembly. The transaction card holder assembly comprises a transaction card holder and a tab extending from the transaction card holder assembly. The tab has a free end for passing through an aperture in a transaction card assembly, which comprises a transaction card mounted upon a transaction card backer panel. The transaction card assembly is suspended from the transaction card holder assembly by passing the fee end of the tab through the aperture to attach to a surface of the transaction card holder assembly.
[0010] A gift card hanger system according to the present invention may include a gift card assembly attached to a gift card holder assembly by suspending the gift card assembly from the holder assembly by a looped tab secured at either end to the gift card holder assembly. The gift card assembly may include a panel bearing an attached gift card. The gift card holder assembly may include a panel bearing a gift card holder.
[0011] A gift card holder system according to the present invention may include a gift card holder assembly including a first backer panel, a detachable gift card holder attached to a face of the first backer panel, an elongated tab extending from a lower portion of the first backer panel, the tab including a free end, and a second backer panel including means for temporarily holding a gift card, the second backer panel including an aperture for accepting the free end therethrough, the first backer panel including means for attaching the free end to the first backer panel. The holder may include two hingedly connected panels and a means for holding a gift card. The holder may include three hingedly connected panels and a means for holding a gift card. The holder may include a container including a flap closure.
[0012] Other advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example an embodiment of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a front view of a gift card mounted upon a gift card backer panel prior to installation upon a gift card holder backer panel.
[0014] FIG. 2 is a side view of a gift card holder backer panel showing the tab projecting from the lower margin of the holder backer panel and partially bent upward and rearward.
[0015] FIG. 3 is a rear view of a holder backer panel.
[0016] FIG. 4 is a front view of a gift card backer panel suspended from a holder backer panel via a looped tab.
[0017] FIG. 5 is a front view of second backer panel.
[0018] FIG. 6 is a rear view of the second backer panel of FIG. 5 showing a fold line.
[0019] FIG. 7 is a side view of the second backer panel of FIG. 6 showing the lower portion of the second backer panel lifted upward and rearward and away from the lower portion of the gift card.
[0020] FIG. 8 is a front view of a second backer panel showing the gift card mounted to project below the bottom edge of the panel.
[0021] FIG. 9 is a rear view of the second backer panel of FIG. 8 showing the gift card magnetic strip.
[0022] FIG. 10 is a rear view of a second backer panel provided with a window for exposing a gift card bar code.
[0023] FIG. 11 is a front view of a gift card assembly suspended from a gift card holder assembly and showing the upper flap of a gift card holder lifted to show interior details.
[0024] FIG. 12 is a front view of an alternative embodiment of a gift card holder assembly having a tab formed integrally from the gift card holder backer panel.
[0025] FIG. 13 is a rear view of the gift card holder assembly of FIG. 12 .
[0026] FIG. 14 is a front view of an alternative embodiment of a gift card hanger system showing a gift card assembly suspended from a gift card holder assembly by a looped tab integral to the gift card holder backer panel.
[0027] FIG. 15 is a rear view of the hanger system of FIG. 14 .
DETAILED DESCRIPTION
[0028] As required, one or more detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
[0029] Referring now to FIGS. 1 through 4 , there is shown an embodiment of a system for hanging a transaction card, such as a gift card, as indicated generally by the reference numeral 100 . The system 100 includes a gift card holder assembly 105 and a gift card assembly 110 . The holder assembly 105 and gift card assembly 110 are attached to one another by suspending the gift card assembly 110 from the holder assembly 105 via a strip or tab 115 .
[0030] The holder assembly 105 includes a gift card holder 120 for holding, retaining or storing a gift card 125 after removal of the gift card 125 from the gift card assembly 110 . The holder 120 is typically formed of one or more relatively planar panels of cardstock or the like and typically includes indicia thereon for indicating both the names of the sender and recipient of a gift card 125 , indicia for indicating a message thereon from the sender to the recipient, decorations of various styles or themes, and one or more slots for inserting a gift card 125 into the holder 120 , or other means for holding the gift card 125 to, or within, the holder structure. When presented for sale, the holder 120 is typically mounted on a first backer panel 130 typically formed of card stock or the like. The first backer panel 130 includes a front surface 130 a, rear surface 130 b , top edge 130 c , bottom edge 130 d , left edge 130 e and right edge 130 f . A peg hole 135 is typically provided proximate the top edge 130 c for hanging the first backer panel 130 and attached holder 120 upon a display rack peg (not shown). The holder 120 may include electronics for recording and playing sound such as music and/or a message from the gift giver. The electronics may include a sound speaker, a power source such as one or more commonly available watch batteries, a control circuit, a memory chip for storing sound recordings, and record and playback buttons.
[0031] A gift card 125 , typically provided with a magnetic strip, bar code and/or ID number associated with one or more monetary values or monetary accounts, is mounted on a second backer panel 140 using temporary or removable adhesive 155 or other operable means. In FIGS. 5 and 6 , a strip of removable adhesive 155 (shown in phantom lines) is interposed between the gift card 125 and the front surface 140 a of the second backer panel 140 to adhere the gift card 125 to the second backer panel 140 .
[0032] The second backer panel 140 includes a front surface 140 a , rear surface 140 b , top edge 140 c , bottom edge 140 d , left edge 140 e and right edge 140 f . The second backer panel 140 is also typically provided with a peg hole 145 proximate the top edge 140 c that may be used either for hanging the second backer panel 140 upon a display rack peg or for use within the system 100 disclosed herein.
[0033] As shown in FIGS. 5 , 6 and 7 , the second backer panel 140 may be provided with a fold line 150 that extends transversely across the second back panel 140 between the left edge 140 e and right edge 140 f . The fold line 150 and gift card 125 are positioned relative to each other so that the portion of the second backer panel 140 bearing the adhesive 155 (or other means of retaining or attaching the gift card 125 to the second backer panel 140 ) lies above the fold line 150 . Typically, the fold line 150 will traverse the lower portion of the second backer panel 140 . At the point of purchase of a device according to the system 100 , the gift card 125 is typically scanned by the cashier to activate the gift card 125 or load it with a monetary or other value. To facilitate scanning, the bottom edge 140 d of the second backer panel 140 is lifted upward, in the direction of arrow A, as shown in the side view of the second backer panel 140 in FIG. 7 . The lower portion 140 g of the second backer panel 140 that pivots about the fold line 150 may be referred to as a flap 140 g . After the flap 140 g is lifted, the magnetic strip 127 of the gift card 125 may be inserted into the slot of a magnetic card reader or scanner (not shown) without interference from or obstruction by the lower portion of the second backer panel 140 .
[0034] Alternatively, as shown in FIGS. 8 and 9 , the gift card 125 may be disposed upon the second backer panel 140 so that the magnetic strip 127 of the gift card 125 projects below the bottom edge 140 d of the second backer panel 140 . As shown in FIGS. 8 and 9 , a shortened version of the second backer panel 140 may be used to expose the lower portion of the gift card 125 while retaining the same space above the gift card 125 on the front surface 140 a of the second backer panel 140 . Alternatively, the gift card 125 may simply be positioned further down upon the second backer panel 140 . In such case, the fold line 150 may be omitted. Either structure enables the magnetic strip 127 to be readily scanned at the point of sale by passing exposed lower portion of the gift card 125 , including the magnetic strip 127 , through a card reader (not shown) without the need for removing the card 125 from the second backer panel 140 .
[0035] Alternatively, in the case of a gift card 125 provided with a bar code or other optically scannable indicia on the back of the gift card 125 , the second backer panel 140 may include an opening, aperture or window 165 in alignment with the bar code so that it may be scanned (typically at the point of sale) without removing the gift card 125 from the second backer panel 140 . FIG. 10 provides a rear view of a second backer panel 140 showing the rear surface 140 b and a window 165 in the lower portion of the second backer panel 140 disposed to align with a bar code 167 (visible through the window 165 , see FIG. 10 ) on a rear surface of a gift card 125 . The gift card 125 , which is mounted on the front surface 140 a , is indicated in phantom lines.
[0036] The gift card holder assembly 105 is provided with a strip or tab 115 projecting from the bottom edge 130 d of the first backer panel 130 . The tab 115 may be formed of acetate, plastic, paper or the like. Any operable material may be selected of appropriate flexibility and strength. As shown in FIG. 2 , the upper portion of the tab 115 may be sandwiched and secured between front and back cooperating panels that form the first backer panel 130 . Alternatively, and particularly when the first backer panel 130 is formed from a single sheet of material, the tab 115 may simply be attached to the front surface 130 a or more preferably the rear surface 130 b of the first backer panel 130 .
[0037] In order to assemble an apparatus according to the system 100 , the tab 115 is looped through the peg hole 145 of the second backer panel 140 and then affixed via adhesive 160 (such as a section of double stick tape) or equivalent means to a surface of the first backer panel 130 , preferably but not necessarily the rear surface 130 b , to form a loop 117 (see FIG. 4 ) by which the gift card assembly 110 may be suspended from the gift card holder assembly 105 . As shown in FIGS. 1 and 2 , the lower portion of the tab 115 is lifted upward in the direction of arrow B to generally pivot around line 115 b to thereafter contact a target surface 130 g of the rear surface 130 b of the first backer panel 130 (as indicated by phantom lines 130 g in FIG. 1 ) to form loop 117 . It should be appreciated that the lower portion 115 c of the tab 115 is first passed through the peg hole 145 of the gift card assembly 110 prior to attachment to the target surface 130 g so that the tab 115 forms a loop 117 holding the second backer card 140 to the first backer card 130 and, therefore, the gift card assembly 110 to the gift card holder assembly 105 , as shown in FIG. 4 .
[0038] In certain embodiments of the system 100 , the lower portion of the tab 115 (typically the rearward surface) is provided with a strip of adhesive 115 a that contacts and adheres to the target surface 130 g when the lower portion of the tab 115 is lifted to meet the first backer panel 130 . In the other embodiments, the tab 115 is adhered to a section of double stick tape 160 located on the target surface 130 g after the tab 115 is passed through the peg hole 145 .
[0039] After purchase of a device according to the system 100 , the gift card 125 may be removed from the second backer 140 and installed within or upon the gift card holder 120 . In certain embodiments, the gift card holder 120 may then be detached from the first backer 130 card prior to giving the gift card holder 120 bearing the gift card 125 to a gift recipient. In further embodiments, an envelope is included with the system 100 and the gift card holder 120 is inserted into the envelope after it is detached from the second backer 140 .
[0040] FIG. 11 illustrates an example of a gift card holder 120 A comprising two flaps of cardstock or the like defined from one another by a hinge or fold line 120 a . Typically, as when presented for sale, the upper flap 180 lies flat against the lower flap 185 , however, in this illustration the upper flap 180 is shown lifted upward to expose interior details, namely, slits 190 a and 190 b in the upper flap 180 , to/from indicia 195 a and 195 b and message indicia 197 . After purchase of a device according to the system 100 , the gift giver (typically the buyer) may indicate the name of the gift recipient as prompted by the “To:” indicia 195 a , the name of the gift giver as prompted by the “From:” indicia 195 b , provide a written message as prompted by the “Message” indicia 197 , and remove the gift card 125 from the second backer panel 140 and install it in the holder 120 A as generally indicated by arrow C. The gift card 125 may be attached to or installed in the holder 120 A by slipping diagonally opposing corners of the gift card into slits 190 a and 190 b as indicated in phantom lines 125 A in FIG. 11 .
[0041] As illustrated in FIGS. 12 through 15 , an alternative embodiment of the system 100 A includes a first backer panel 130 A with an integral strip 115 A formed from the same piece of material (typically card stock, thin plastic, paper or the like) as the first backer panel 130 A. FIG. 12 is a front view of a gift card holder assembly 105 A having a tab or strip 115 A formed integrally from the gift card holder backer panel (first backer panel 130 A). The strip 115 A may be scored 116 to facilitate bending it in the general direction indicated by arrow D after looping it through the second backer panel 140 peg hole 145 . Notches 170 and 175 in the first backer panel 130 A, separate and define an upper portion of the strip 115 A from the adjacent portions of the backer panel 130 A.
[0042] The notches 170 and 175 allow the second backer panel 140 to be drawn further upward and in overlapping engagement with the first backer panel 130 A after the free end of the strip 115 A is passed through the peg hole 145 and secured to the rear surface of the first backer panel 130 A using adhesive 160 , such as double stick tape or the like. As illustrated in FIG. 14 , the upper portion of the second backer panel 140 slides into the notches 170 and 175 as the second backer panel 140 drawn upward by fastening the free end of the looped strip 115 A to the back of the first backer panel 130 A. Note that as indicated in FIG. 13 , which shows a rear view of the first backer panel 130 A, the adhesive may be placed near the free end of the strip 115 A or on the rear surface of the first backer panel 130 A at the point where the free end of the strip 115 A will meet when secured to form a loop 117 A. FIG. 14 is a front view of the gift card assembly 110 suspended from the gift card holder assembly 105 A by the looped tab 115 A integral to the gift card backer panel 130 A. FIG. 15 is a rear view of the gift card assembly 110 suspended from the gift card holder assembly 105 A via loop 117 A.
|
A system for hanging a gift card includes a gift card assembly suspended from a gift card holder assembly by a looped strip of flexible material. The gift card assembly includes a removeably attached gift card and the gift card holder assembly includes a gift card holder for receiving the gift card after detachment from the gift card assembly.
| 1
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a process for producing and multiplying lymphocytes as well as a composition which is suitable as a culture medium for lymphocytes.
2. Description of the Related Art
The production and multiplication of lymphocytes is problematic. Some types of lymphocytes cannot be cultured at all in vitro or are very difficult to culture in vitro. Native B lymphocytes can for example only be cultured for a short period and T lymphocytes require difficult culture conditions for longer culture such as a combination of growth factor(s) and “feeder cells” (“nurse cells”) or the use of unphysiological and potentially dangerous substances such as tumour promoters (phorbol esters) in combination with ionophoric substances (e.g. ionomycin) or plant lectins (e.g. phytohaemagglutin, PHA). This puts severe constraints on possibilities for the long-term culture and multiplication of T lymphocytes and other lymphocytes, and the production of lymphocytes in significant amounts for diagnostic or therapeutic purposes is very limited or impossible.
However, there is manifold interest in the ability to produce, culture and multiply lymphocytes in vitro e.g. B lymphocytes as producers of specific antibodies or cytotoxic T lymphocytes (CTL) to treat infections or tumours, in addition regulator T lymphocytes (helper or suppressor T lymphocytes) for the diagnosis and treatment of autoimmune diseases or “natural killer (NK) lymphocytes for treating malignant growths.
Hybridoma cells which are formed from a fusion of B lymphocytes or T lymphocytes with malignant, lympoid cells (e.g. myeloma cells) can be cultured and multiplied without difficulty. Such hybridoma cells have the immunological function of the original lymphocytes as well as the essentially unlimited ability to proliferate of the malignant fusion partner. However, the application of the hybridoma technique is limited to a few animal species (mouse, rat) and essentially fails in other mammalian species and also in particular in humans.
A process for the production of proliferating CD4+ lymphocytes is described in WO90/10059. According to this peripheral mononuclear blood cells (PBNMC) are treated with alkyl esters to remove monocytes and granulocytes and subsequently cultured in a culture medium which contains a T cell stimulant and/or IL-2. Mitogens such as PHA are used as the T cell stimulant. However, the use of IL-2 alone only leads to a low proliferation of the cells. The addition of mitogenic substances during the culture of cells which are subsequently to be implanted into a patient is critical.
A process for the culture of T cells in the presence of interleukin-2 is also described in EP-A 0 203 403. A disadvantage of this process is also that the T cells can only be proliferated to a slight extent by this means.
A process for culturing and multiplying tumoricidal T lymphocytes is described in WO94/23014 by co-culturing lymphocytes with a cell line (stimulator cells) while avoiding an allogenic stimulation and without addition of interleukin-2. In this process resting T lymphocytes are activated to effector cells which recognize and kill tumour cells or inhibit their growth. A considerable amount of fermentation is required to provide such stimulator cells for the mass proliferation of for example tumoricidal killer T cells. In addition the killer T cells must be separated in a sterile manner from these stimulator cells or their cell debris before use (reinfusion into the patient).
V. Kutnik et al., Period. Biol. 92 (1990) 48 describe that, in the allogenic mixed lymphocyte reaction of mouse spleen lymphocytes, the addition of IL2 restores the cyclosporin A-induced inhibition of the proliferation of the responder cells and increases their alloreactivity.
Pierson, B. A. et al., Blood 87 (1996) 180-189 describe that isolated human NK cells (CD56+, CD3−) can be multiplied to a slight extent in culture by adding IL2. The addition of supernatants of irradiated mononuclear cells from blood increases the multiplication of the NK cells. Thrombospondin was identified as the active principle of this effect which does not act directly but rather indirectly by activation of latent TGFβ. TGFβ activated in this manner inhibits the proliferation in the early phase of the culture and increases the further proliferation. A repeated addition of TGFβ when the medium is changed inhibits the growth of the cells and in this case suppresses the proliferation of the NK cells. In Immunological Invest. 25 (1996) 129-151 I. A. Ayoub investigates the effect of human TGFβ on a bovine CD4+ lymphoblastoid T cell line (BLTC) which grows autonomously in IL2-containing medium. The cell line is arrested in medium without IL2. The addition of TGFβ to the arrested BLTC drives them rapidly into apoptosis. The simultaneous addition of IL2 abolishes the arrest and prevents the induction of apoptosis. The addition of TGFβ to suboptimal concentrations of IL2 co-stimulates the proliferation of the BLTC.
In Intern. Immunol. 6 (1994) 631-638 R. de Jong describes the effect of TGFβ1 on the proliferation of isolated subpopulations of human CD4+ T lymphocytes. TGFβ1 amplifies the proliferation of CD4 cells (CD45 RA+) by antibodies in the presence of IL2, but the proliferation of pre-activated T cells (CD45 RO+) is inhibited by the addition of TGFβ1. However, it turned out that the induced proliferation of the CD45 RA+ cells is inhibited after five days by addition of TGFβ1.
A. Cerwenka describes in J. Immunol. 156 (1996) 459-464 that the presence of TGFβ1 during the primary stimulation of human T lymphocytes increases their ability to survive in secondary cultures and reduces their susceptibility to apoptosis-inducing anti-Fas antibodies. The addition of TGFβ1 also reduces the apoptosis susceptibility of primary activated T lymphocytes to secondary activation. A survival of the T cells over a long period is ensured in the presence of IL2 and TGFβ1.
T. H. Inne et al., J. Immunol. 148 (1992) 3847-3856 describe that the proliferation of CTLL-2 cells (murine T cell line) in IL2-containing medium is inhibited by addition of TGFβ1. In addition to the inhibition of proliferation, TGFβ1 induces a change in the cell morphology and induces the expression of the surface molecule CD8 in CTLL-2. A combination of IL2 and TGFβ also induces an increased expression of CD8 in murine thymocytes which have been activated by phorbol dibutyrate and ionomycin. In this case the addition of TGFβ1 also reduces the proliferation rate.
However, TGFβ is not a substance that is readily and cheaply available in adequate amounts. TGFβ is usually either isolated from natural sources or produced recombinantly. The main object of the invention was to provide an effective and cheap means for culturing and multiplying lymphocytes as well as a process for the production of pancytotoxic T cells. A further object of the present invention is to provide a process which enables lymphocytes to be produced, cultured and/or multiplied in a simple manner on a large scale.
SUMMARY OF THE INVENTION
The subject matter of the invention is a process for culturing and/or multiplying lymphocytes in a cell culture medium which contains a lymphocyte growth factor and additionally aurintricarboxylic acid, cyclosporin and/or ascomycin.
Surprisingly the process according to the invention enables lymphocytes with special properties to be produced in a simple manner, to be cultured over a long period and to be multiplied on a considerable scale. The process according to the invention is particularly suitable for culturing and multiplying T lymphocytes and NK lymphocytes.
Furthermore it has turned out that the process according to the invention particularly advantageously enables lymphocytes to be cultured over a long period (more than 14 days) and to be multiplied on a large scale (factor of 100, 1000 or more). In addition a combination of a lymphocyte growth factor and additionally aurintricarboxylic acid, cyclosporin and/or ascomycin enables pancytotoxic T cells to be multiplied from lymphocyte mixtures by long-term culture, preferably from a lymphocyte cell population and hence enables such cells to be produced simply and in large amounts.
A lymphocyte growth factor is understood as a substance which is able to promote cell division of lymphocytes. Lymphocyte growth factors are known to a large extent to a person skilled in the art. Suitable T lymphocyte growth factors are for example interleukin 1 (IL-2) and interleukin 15 (IL-15). A suitable NK lymphocyte growth factor is e.g. IL-15. Suitable B lymphocyte growth factors are for example interleukin 13 (IL-13), IL-14 and IL-10 (Callard, R. E., and Gearing, J. H., The Cytokine Facts Book, Academic Press, London, 1994).
Surprisingly ciclosporin (e.g Cyclosporin A®), ascomycin (FK520) and/or tacrolimus (FK506) can be used according to the invention to increase proliferation. These are substances which bind to a cyclophilin and inhibit calcineurin in this complex. Other substances which have these properties are also suitable according to the invention. Pazderka-F., et al., Transpl. Immunol. (1996) 23-31, Rusnak-F., et al., Bone-Marrow-Transplant 17 (1996) 309-13, Su-Q., et al., Ren-Physiol-Biochem. 18 (1995) 128-39, Baughman-G., et al., Mol-Cell-Biol. 15 (1995) 4395-402, Kawamura, A., et al., J-Biol-Chem. 270 (1995) 15463-6, Kakalis, L T., et al., FEBS-Lett. 362 (1995) 55-8.
Surprisingly aurintricarboxylic acid (ATA) can also be used to increase the proliferation of lymphocytes. Aurintricarboxylic acid is a substance which inhibits the interaction of proteins and nucleic acids [Gonzales, R. G. et al.: Biochemistry 19: 4299-4303 (1980)] and is a general inhibitor of nucleases.
The amount of aurintricarboxylic acid which is added in the process according to the invention can also be varied and is to a certain extent dependent on the medium used and on the cell to be cultured. It has turned out that for example when culturing tumour-infiltrating lymphocytes (TIL) in serum-containing medium it is advantageous to add 0.1-100 μM ATA.
Lymphocytes within the sense of the invention are understood as leucocytes which are derived from lymphocyte progenitor cells in the haematopoietic system and can be for example found in blood, in the lymph, in the spleen, in lymph nodes, in tumours (tumour-infiltrating lymphocytes, TIL) or inflamed tissue. Important subgroups are T lymphocytes, NK lymphocytes and B lymphocytes. B lymphocytes are antibody-producing lymphocytes in their mature form.
T lymphocytes (T cells) are understood as lymphocytes which are for example involved in cell-mediated cytotoxicity, in allergy of the delayed type and in the activation of B lymphocytes. There are numerous different types (subtypes) of T cells which can be each distinguished by their function and/or their cell surface antigens (see e.g. Imm. Rev. (1993), 74 and (1992), 82; Advances in Immunology 58 (1995) 87). Such surface antigens are for example referred to as CD (Cluster of Differentiation) antigens. The expression of the antigen-recognizing T cell receptor is typical for all T cells. T cells develop from haematopoietic stem cells and mature, with some exceptions, in the thymus. Examples of T cells are cytotoxic T cells, helper T cells, suppressor T cells, suppressor-inducer T cells and killer T cells.
Natural killer cells (NK cells) are lymphoid cells which develop from haematopoietic stem cells and differ from T cells and B cells in that they express neither the T cell receptor nor the B cell receptor and are CD3−.
DETAILED DESCRIPTION OF THE INVENTION
The culture of lymphocytes in the process according to the invention is carried out in a conventional basic culture medium which additionally contains a lymphocyte growth factor and cyclosporin and/or ascomycin. All media are suitable as basic culture media which are usually used to culture mammalian cells. Such culture media can either contain serum or be serum-free and are known to any person skilled in the art. Examples are RPMI 1640-medium, Dulbecco's Modified Eagles Medium (DMEM), F12 medium or a mixture of the latter (DF medium) which can be used in a serum-containing and also in a serum-free form. If serum-free media are used, the medium must be supplemented by critical components. Such critical components are, as known to any person skilled in the art, albumin, transferrin, selenite and insulin. Serum-free media which already contain all critical supplements such as e.g. the culture medium X-Vivo 20® (Bio-Whittaker, Serva) are also particularly suitable.
The amounts of lymphocyte growth factor and cyclosporin and/or ascomycin which are added in the process according to the invention can vary and, to a certain extent, depend on the medium used (serum-free or serum-containing) and on the cell to be cultured. It has turned out that in serum-free culture amounts of 0.1-10×10 −9 mol/l growth factor and 10 −10 -10 −2 mol/l cyclosporin and/or ascomycin are suitable. Consequently in the culture of T cells and/or NK cells in serum-free medium it is advantageous to for example add 10-20 ng/ml IL-2 or IL-15 and 5-20 ng/ml Cyclosporin-A® and/or 1-10 ng/ml Ascomycin®.
The process according to the invention is especially suitable for culturing and multiplying killer T cells (KT cells) and tumoricidal killer T cells. Such tumoricidal killer T cells can for example be produced according to WO 94/23014 by co-culturing lymphocytes, which for example have been isolated from blood, with stimulator cells. In this process resting T lymphocytes are activated to effector cells which recognize and kill tumour cells and inhibit their growth. The activated T lymphocytes are stimulated to proliferate in this co-culture and can be further cultured and multiplied by the process according to the invention.
The process according to the invention is also advantageous for the production and multiplication of pancytotoxic T cells. A combination of a lymphocyte growth factor with aurintricarboxylic acid, and a substance which binds to cyclophilin and inhibits calcineurin in this complex, or an apoptosis antagonist is suitable. In addition the process according to the invention enables the sustained proliferation of blood lymphocytes after treatment with leucyl-leucine-methyl ester. The phenotyping of such cells produced according to the invention on the basis of surface markers shows that the proliferating cells are uniformly T lymphocytes (100% CD3+). These cells exhibit a previously unknown activity which is referred to as pancytotoxic activity in the following. Pancytotoxic T cells are characterized in that they indiscriminately kill normal cells such as e.g. fibroblasts, keratinocytes or endothelial cells and also tumour cells such as e.g. malignant melanoma, T lymphoma or lung carcinoma. Surprisingly pancytotoxic T cells can be produced from mononuclear cells by treatment with a combination IL-2 and apoptosis antagonists. Pancytotoxic T cells can be used advantageously for the local treatment of tumours (e.g. tumour metastases).
An apoptosis antagonist (apoptosis inhibitor) is to be understood as a substance which is able to not allow the genetically determined self-destruction program to become effective in a cell that would lead to cell death after activation, and which partially or completely slows or prevents the lysis of a cell after activation of a suicide signal. Suitable substances are for example described in Kroemer, G., Advances in Immunology 58 (1995) 211-296. According to the invention substances are suitable which are able to inhibit agents with an apoptosis signal effect on lymphocytes (e.g. an antibody to TNFα which prevents binding of this cytokine to its receptor). Furthermore substances are suitable which prevent reception of an apoptosis signal by the lymphocytes (e.g antibody to the TNFα receptor which inhibits binding of TNFα to this receptor). Substances are also suitable which are able to prevent apoptosis by interrupting the signal chain from the cell membrane into the inside of a lymphocyte (e.g. an inhibitor of sphingomyelinase, inhibition of the formation of ceramide). Finally an apoptosis inhibitor is also to be understood as a substance which is able to activate the anti-apoptosis program in a lymphocyte which is also genetically determined (e.g. up-regulation of the bcl-2 expression). Cyclosporin and ascomycin are also suitable as calcineurin inhibitors.
It has surprisingly turned out that when mononuclear blood cells (PBMNC) are cultured without pre-treatment with leucyl-leucine-methyl ester, lymphocytes usually grow after a latency period of 14-28 days which can be multiplied as desired. Phenotyping of these cells shows that they represent a mixture of T cells (CD2+, CD3+) and NK cells (CD2+, CD3−, CD16+). Functionally they are also pancytotoxic and thus differ from KT cells. In this case it is also preferable to use IL2 or IL15 as a lymphocyte growth factor and Cyclosporin or Ascomycin.
The following examples, publications and the figures further elucidate the invention, the scope of which results from the patent claims. The described processes are to be understood as examples but still describe the subject matter of the invention even after modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the growth behaviour of killer T cells in serum-free DF medium on addition of IL-2+CsA(A) and CsA alone (B).
FIG. 2 shows the growth behaviour of killer T cells in serum-free DF medium on addition of IL-15 and CsA(A) and IL-15 alone (B).
FIG. 3 shows the growth behaviour of killer T cells in serum-free DF medium on addition of IL-2 and Ascomycin (FK520) (A) and Ascomycin alone (B).
FIG. 4 shows the growth behaviour of killer T cells in serum-free DF medium on addition of IL-2 and aurintricarboxylic acid (A) and arintricarboxylic acid alone (B).
EXAMPLE 1
Production of Killer T Cells
Mononuclear cells from peripheral blood (PBMNC) of human donors are isolated by means of gradient centrifugation (lymphocyte separation medium, BM), washed twice with phosphate-buffered saline solution and incubated at a density of 5-10×10 6 cells/ml DF medium according to Thiele and Lipsky (J. Immunol. 136 (1986) 1038-1048) with 250 μM leucyl-leucine-methyl ester (BM) for 20 minutes at room temperature. After washing with DF medium the cells are cultured at 37° C. in 8% CO 2 atmosphere at a density of 1-2×10 6 per ml DF medium together with irradiated (2000 rad) HB654 cells or HB617 cells (stimulator cells; 2-5×10 5 per ml). On day 5-6 of the co-culture half to two thirds of the culture medium is renewed and irradiated stimulator cells (2-5×10 5 per ml) are added again. From day 8-10 after starting the co-culture, when all stimulator cells have been destroyed by the cytotoxic activity of the killer T cells, the killer T cells are used for the following examples.
Phenotyping the cells on day 10 of the co-culture shows that >95% of the cells are CD3+, ca. 40% CD4+ and ca. 60% CD8+. Cells with the markers CD19 or CD16 are not found.
EXAMPLE 2
Multiplication of Killer T Cells in Serum-free Medium which Contains Interleukin-2 (IL-2) and Cyclosporin A (CsA).
Killer T cells which have been produced according to example 1 are washed once in DF medium and cultured at a density of 5×10 5 per ml DF medium in two separate preparations that are denoted A and B. Human recombinant IL-2 (BM; 20 ng/ml) and CsA (Sandoz; 12.5 ng/ml) are added to preparation A. Only CsA (12.5 ng/ml) is added to preparation B. Half of the culture medium is renewed every second day and the cell count is adjusted to 5×10 5 per ml.
As shown in FIG. 1 the killer T cells multiply in preparation A (IL-2+ CsA) with a doubling time of about 48 hours for at least ten doubling cycles (corresponds to 1000-fold multiplication). In preparation B (only CsA) the killer T cells do not multiply.
EXAMPLE 3
Multiplication of Killer T Cells in Serum-free Medium which Contains Interleukin-15 (IL-15) and Cyclosporin A (CsA).
Killer T cells which have been produced according to example 1 are washed once in DF medium and cultured at a density of 5×10 5 per ml DF medium in two separate preparations that are denoted A and B. Human recombinant IL-15 (R & D Systems; 15 ng/ml) and CsA (Sandoz; 12.5 ng/ml) are added to preparation A. Only IL-15 (15 ng/ml) is added to preparation B. Half of the culture medium is renewed every second day and the cell count is adjusted to 5×10 5 per ml.
As shown in FIG. 2 the killer T cells multiply in preparation A (IL-15+CsA) with a doubling time of about 48 hours for at least 11 doubling cycles. In preparation B (only IL-15) the proliferation stagnates after 3 doubling cycles.
EXAMPLE 4
Multiplication of Killer T Cells in Serum-free Medium Containing Interleukin-2 (IL-2) and Ascomycin (FK 520).
Killer T cells which have been produced according to example 1 are washed once in DF medium and cultured at a density of 5×10 5 per ml DF medium in two separate preparations that are denoted A and B. rh IL-2 (20 ng/ml) and Ascomycin (Calbiochem; 2.5 ng/ml) are added to preparation A. Only Ascomycin (2.5 ng/ml) is added to preparation B. Half of the culture medium is renewed every second day and the cell count is adjusted to 5×10 5 per ml.
As shown in FIG. 3 the killer T cells multiply in preparation A (IL-2+Ascomycin) with a doubling time of about 48 hours for at least ten doubling cycles. In preparation B (only Ascomycin) no multiplication of killer T cells is observed.
EXAMPLE 5
Multiplication of NK and T Lymphocytes from Mononuclear Cells of Human Blood in Serum-free Medium Which Contains Interleukin-2 (IL-2) and Transforming Growth Factor-β1 (TGF-β1).
Mononuclear cells from peripheral blood (PBMNC) of a human donor are isolated by means of gradient centrifugation (lymphocyte separation medium, Boehringer Mannheim GmbH, Germany (BM)), washed twice with phosphate-buffered saline solution and taken up in DF medium at a density of 1×10 6 cells/ml and cultured in three separate preparations which are denoted A, B and C. Recombinant human IL-2 (BM, 20 ng/ml) and rh TGFβ1 (BM, 4 ng/ml) are added to preparation A, only IL-2 (20 ng/ml) is added to preparation B and only TGFβ1 (4 ng/ml) is added to preparation C. Half of the culture medium (+cytokine(s)) is renewed every second day and the cell count is adjusted to ca. 1×10 6 cells/ml during the first 7 days and subsequently to ca. 0.5×10 5 cells/ml.
In preparation A (IL-2+TGFβ1) the number of non-adherent lymphoid cells increases approximately from day 5 after the beginning of the culture, firstly with a doubling time of ca. 96 hours, from day 20 when no more colonies with adherent monocytic cells are detectable with a doubling time of less than 48 hours. On day 50 of the continuous culture the cell count has increased more than 10 4 -fold compared to the initial state. The analysis of the cells with regard to their surface markers yields the following result on day 50: the population contains:
ca. 50% NK cells (CD2+, CD3−, CD16+, CD56+) and
ca. 50% T cells (CD3+, CD4+, CD8+)
In preparation B (only IL-2) lymphoid cells only multiply moderately (<50-fold) over ca. 16 days, then stagnate and die after ca. 20 further days.
In preparation B (only TGFβ1) the cells do not multiply.
EXAMPLE 6
Multiplication of Killer T Cells in Serum-free Medium Containing Interleukin 2 (IL-2) and Aurintricarboxylic Acid (ATA).
Killer T cells which have been produced according to example 1 are washed once in DF medium and cultured at a density of 5×10 5 per ml DF medium in two separate preparations that are denoted A and B. IL-2 (20 ng/ml) and aurintricarboxylic acid (Aldrich Chemie; 4.2 μg/ml) are added to preparation A. Only aurintricarboxylic acid (4.2 μg/ml) is added to preparation B. Half of the culture medium is renewed every third day and the cell count is adjusted to 5×10 5 per ml.
As shown in FIG. 4 the killer T cells multiply in preparation A (IL-2+ATA) with a doubling time of about 72 hours for at least 11 doubling cycles. In preparation B (only ATA) the killer T cells do not multiply.
EXAMPLE 7
Multiplication of Tumour-infiltrating Lymphocytes in a Medium which Contains Interleukin-2 (IL-2) and Aurintricarboxylic Acid (ATA).
The nodules of a human colon carcinoma which was removed by an operation from the large intestine is freed of connective tissue and normal parts of the intestine and cut into ca. 2×2×3 mm pieces. The tumour fragments are taken up in Iscove-modified DME medium (Gibco) which contains 15% FCS (BM) and divided equally into four culture dishes which are named A, B, C and D. IL-2 (20 ng/ml) is added to preparation A, aurintricarboxylic acid (4.2 μg/ml) is added to preparation B and IL-2 (20 ng/ml) plus aurintricarboxylic acid (4.2 μg/ml) is added to preparation C. Preparation D remains without additions. Three quarters of the respective culture media is removed each second day without changing the tissue or cell content. Microscopic control of the cultures shows that after 24-48 hours lymphocytic cells migrated out of the tumour tissue fragments which multiplied in the partial culture C which contains IL-2 plus ATA but not in the partial cultures A, B or D. After a ten day culture the picture is as follows: In A and B (only IL-2 or ATA) the number of emigrated lymphocytes has remained constant compared to day 2, in D (no additives) hardly any lymphocytes are detectable. In the partial culture C the number of lymphocytes has increased 20-fold compared to A or B. The lymphocytes from C are isolated from the partial culture C and they are analysed on the basis of their surface markers. The population contains:
ca. 60% T lymphocytes (CD3+, CD4+, CD8+, CD19−)
ca. 25% NK cells (CD2+, CD3−, CD56+, CD19−) and
ca. 15% B lymphocytes (CD19+, CD3−).
LIST OF REFERENCE
Advances in Immunology 58 (1995) 87
Ayoub, I. A., Immunological Invest. 25 (1996) 129-151
Baughman-G., et al., Mol-Cell-Biol. 15 (1995) 4395-402
Callard, R. E., and Gearing, J. H., The Cytokine Facts Book, Academic Press, London 1994
Cerwenka, A. J. Immunol. 156 (1996) 459-464
EP-A 0 203 403
Immm. Rev. (1992) 82
Imm. Rev. (1993) 74
Inne, T. H., et al., J. Immunol. 148 (1992) 3847-3856
Jong de, R., Intern. Immunol. 6 (1994) 631-638
Kakalis, L. T., et al., FEBS-Lett. 362 (1995) 55-8
Kawamura, A., et al., J-Biol-Chem. 270 (1995) 15463-6
Kroemer, G., Advances in Immunology 58 (1995) 211-296
Kutnik, V., et al., Period. Biol. 92 (1990) 48
Pazderka-F., et al., Transpl-Immunol. (1996) 23-31
Pierson, B. A. et al., Blood 87 (1996) 180-189
Rusnak-F., et al., Bone-Marrow-Transplant. 17 (1996) 309-13
Su-Q., et al., Ren-Physiol-Biochem. 18 (1995) 128-39
Thiele and Lipsky, J. Immunol. 136 (1986) 1038-1048
WO90/10059
WO94/23014
Gonzales, R. G. et al., Biochemistry 19: 4299-4303 (1980)
|
A method for culturing and/or multiplying lymphocytes in cell culture medium which contains as lymphocyte growth factor and additionally, aurin tricarboxylic acid, ciclosporin, tacrolimus, and/or ascomycin.
| 2
|
FIELD AND BACKGROUND OF THE INVENTION
This invention relates in general to sewing machines and in particular to a new and useful thread cutting mechanism.
A thread cutting device is disclosed in German utility model 79 12 758. In this prior art device, a spring acts on the piston rod of the air cylinder by which the first step of motion of the thread catcher is supported and the opposite second step of motion is braked. The spring helps to overcome starting resistances while executing the first step of motion which may occur especially after a longer standstill. During the second step of motion, the spring reduces the speed of the thread catcher insofar as even thin threads can be pulled out without a risk of tearing and moved to the counter-knife, and satisfactory cutting is effected even under adverse conditions. The thread catcher is further equipped with a second air cylinder whose piston rod, with the thread catcher standing still, engages an opening of a member which is connected to the piston rod of the first air cylinder, thereby preventing the spring from pulling the thread catcher into the path of motion of the needle in instances of an air supply failure.
However, a satisfactory operation of the thread catcher requires additional, considerably expensive equipment, namely, aside from the spring, an adjusting device for presetting the spring tension, and the second air cylinder. Even more expensive is the mounting, since the initial tension of the spring must be adjusted as a function of the respective spring rate, and the position of the second air cylinder must exactly correspond to the mounted position of the first air cylinder, to enable it to perform its retaining function.
SUMMARY OF THE INVENTION
The present invention is directed to a simplified design of a thread catcher, also facilitating and accelerating the assembly and mounting.
The use of a piston having two portions of unequal diameters makes it possible to provide a permanent pressurizing of the smaller cylinder space, and to alternately pressurize and vent only the larger cylinder space. Experience has shown that with a permanently pressurized smaller cylinder space and quick venting of the larger cylinder space at a start of the first sign of motion, neither appreciable delays in starting the motion, nor longer periods of standstill are caused.
Due to the providing of a throttling section in the conduit for supplying the large cylinder space and/or in the conduit for permanently venting the larger cylinder space, either the pressure build-up in the larger cylinder is retarded, or an air cushion braking the motion of the piston is produced at the side close to the smaller piston portion of the larger cylinder space. Preferably, a throttling section is provided in both of the conduits. Consequently, the piston speed reduction during the second step of motion needed for a satisfactory function of the thread cutter is obtained by simple pneumatic means alone. Since the cross-sectional area of flow of the throttling passages can be kept within narrow tolerances, with the results, under an assumed constant pressure, of obtaining with different air cylinders always identical flow conditions, no initial adjustment is necessary, in contradistinction to prior art thread cutters where such an adjustment is inevitible because of the varying stiffness of springs.
Upon a pressure failure, the piston stops in its rest position, since, except for the pressure exerted by the compressed air, no other forces act on the piston in rest position. That is why no additional air cylinder retaining the thread catcher is needed in the inventive thread cutting device.
As soon as the surface ratio of the larger to the smaller piston portion exceeds 2 to 1, the piston exerts a stronger force during the second step of motion than during the first step of motion, in spite of the lower speed. This makes sure that even thick threads are reliably cut.
Due to the provision of a damping piston adjacent the piston portion of larger diameter, which is associated with a damping bore adjacent to the cylinder space, the piston is braked at the end of the first step of motion, so that it is prevented from butting hard against the front face of the air cylinder.
The feature of a combined air cylinder and directional valve further simplifies the mounting of the thread cutter, since the otherwise needed flexible tube connections between the valve and the air cylinder are saved. The short communication paths between the valve and the air cylinder reduce the response time and also increases the timing accuracy of the individual switching operations.
The arrangement and design of the directional valve between the conduit for supplying the larger cylinder space and a venting bore, and that the valve piston is provided with sealing fromt surfaces for alternately closing the supply conduit and the venting bore, and with at least one flow channel extending the entire length of the valve piston is a particular simplification, so that a 3/2 directional valve can be employed, requiring actuation with external energy only in one direction, thus, with an electromagnetic actuation, a single effective coil.
Accordingly, it is an object of the invention to provide an improved mechanism for effecting the severing thread in a sewing machine.
A further object of the invention is to provide a mechanism for severing thread in a sewing machine which includes an actuator for moving the thread catcher so that a first step of motion is effected in a rapid and exact manner and a second step is slower but performs greater force.
A further object of the invention is to provide a device for cutting thread in a sewing machine which is simple in design, rugged in construction and economical to manufacture.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings
FIG. 1 is a partial vertical sectional view of a sewing machine with a simplified schematic of the pneumatic control constructed in accordance with the invention;
FIG. 2 is a sectional view of the air cylinder and the directional valve; and
FIG. 3 is a section taken along the line III--III of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in particular the invention embodied therein comprises a thread cutting device for a sewing machine, the plate of which 1 is shown in FIG. 1 over which a needle 4 reciprocates. The thread cutting device includes a thread catcher 6 which includes a thread cutter 5 having a support arm which is movable to present the thread to a knife 7 and which is actuated by a mechanism generally designated 16. The mechanism 16 is moved by a piston rod 15 acting through a linkage mechanism and the piston is moved so that the thread cutter executes a first step of motion to take hold of the threads and a second step of motion in an opposite direction to pull the threads out and move them to the fixed knife 7. Piston rod 15 is actuated by a double acting air cylinder which has a large diameter portion 26 and a small diameter portion 25 and a piston movable therein having a large diameter portion in the large diameter portion of the cylinder and a smaller diameter portion in the smaller diameter portion of the cylinder. The piston is movable so as to effect the first step of motion and the smaller diameter portion of the piston and the larger diameter portion is actuated by pressure fluid to effect the second step of motion. For this purpose the large diameter portion of the cylinder is vented on its end adjacent the small diameter portion thereof and means are provided for pressurizing and venting the large diameter portion of the cylinder on its end opposite to the small diameter portion. The means for alternately pressurizing and venting the large diameter space 26 includes a conduit 35 having a throttling element 43 therein.
FIG. 1 shows the base plate 1 of a sewing machine below which the horizontal shaft 2 for driving the rotary hook 3 is mounted. The rotary hook is secured to the forward end of shaft 2 and cooperates with a needle 4 which is moved up and down by a needle bar (not shown).
Beneath base plate 1, a thread cutter 5 is provided which is designed and operates as described in German Pat. No. 1,125,742. Thread cutter 5 comprises a thread catcher 6 which is mounted coaxially of the rotary hook 3 and cooperates with a knife 7 secured to the underside of the base plate 1. The thread catcher 6 is secured to a supporting arm 8 which is connected to a ring 9 loosely embracing a hook drive shaft 2. Ring 9 is secured against axial displacement and rotatable in an annular track 10 which is secured below base plate 1. Hinged to the supporting arm 8 is a link 11 which is connected to one arm of an angle lever 12 carried by a bracket 13 which is fixed to the housing. The other arm of the angle lever 12 is connected through a link 14 to the piston rod 15 of an air cylinder 16.
Air cylinder 16 comprises a housing or casing 17 having a front wall 18 and a screwable cover 19. Piston rod 15 extends through cover 19 and front wall 18 and carries a piston 20. The piston 20 comprises a small diameter piston portion 21 having a smaller diameter than a large diameter piston portion 22 having a larger diameter. The effective surface of the larger piston portion 22 is more than twice the front face area of the smaller piston portion 21, so that the surface ratio is greater than 2 to 1. Frontally adjacent to the larger piston portion 22 is a damping piston 23 having a smaller diameter than portion 22 and being provided, on its circumference, with a lengthwise extending notch 24. Within case 17, a small cylinder space 25 associated with the smaller piston portion 21 a large cylinder space 26 associated with the larger piston portion 22, and a damping bore 27 associated with damping piston 23 are formed.
A radial bore 29 opens into a vestibule 28 of the cylinder space 25, and an obliquely extending bore 30 opens into cylinder space 26. Further, an axial bore 31 extends from cylinder space 26 to a vertical bore 32 for receiving a screw 33. From bore 32, a cross bore 34 extends to the ambient atmosphere. Bores 31 and 34 form a conduit 35 in which a throttling valve 36 comprising bore 32 and screw 33 is provided.
Secured to casing 17 are two attachments 37 and 38. Attachment 37 is provided with a bore 39 which is aligned with the bore 29. The bore 39 opens into a bore 40 extending crosswise thereto and is connected, at one side, to a compressed air source 41 indicated in FIG. 1, and changes, at the other side, into a narrow bore 42. Bore 42 forms a throttle 43, while bores 29,39,40 form a conduit 44.
Attachment 38 is provided with an oblique bore 25 which is aligned with bore 30. Bore 45 opens into a chamber 48 which is closed by a funnel-shaped wall 47. A bore 49 is provided in wall 47, through which chamber 48 communicates with the ambient atmosphere. In front of bore 47 a disc 50 of sintered metal is secured, serving as a sound absorber.
Screwed into attachment 38 is a cylindrical valve casing 51 which is provided with a bore 52 aligned with bore 42, and with a valve chamber 53 which opens into chamber 48. Bores 42, 52, 45 and 30 and valve chamber 53 form together a conduit 46. Valve chamber 53 accommodates a valve piston 54 whose two front faces 55,56 form sealing surfaces. On the circumferential surface of valve piston 54, four grooves 57 are provided extending axially the entire length of the piston. Valve casing supports an electromagnet 60 comprising a housing 58 and a coil 59, with valve piston 54 operating as the armature. Attachment 38, valve casing 51 with valve piston 54, and electromagnet 60 form a 3/2 directional valve 61.
The device operates as follows:
With the sewing machine both switched on and switched off, bore 40 is connected to compressed air source 41. Consequently, small cylinder space 25 and small piston portion 21 are permanently under pressure, through conduit 44. During a sewing operation, and with the sewing machine stopped, electromagnet 60 is de-energized. Therefore, valve piston 54 is held by the compressed air in its left-hand position as shown in FIG. 2, in which bore 52 is cleared by front face 56, and bore 49 is closed by front face 55. In this position of valve piston 54, large cylinder space 26 and large piston portion 22 are under pressure through conduit 46. The compressed air acting on both sides of piston 20 produces on piston portions 21,22 opposite forces whose magnitudes correspond to the surface ratio. In the view of FIGS. 1 and 2, the force acting toward the right-hand side exceeds thus more than twice the force acting toward the left-hand side, so that portion 20 is securely held in its right-hand position. In this way, thread catcher 6 is also firmly held in its rest position.
At the end of each seam, the sewing machine, controlled by a synchronizer (not shown), is stopped with needle 4 in the upper dead center position. Thread cutter 5 is then released, for example by actuating a foot rocker. This causes one revolution of the main shaft of the sewing machine. During this revolution, about in the lower dead center position of needle 4, electromagnet 60 is energized so that valve piston 54 is pulled to the right. This closes bore 52 and clears bore 49, whereupon cylinder space 26 is vented through bores 30, 45, chamber 48, bore 49, and disc 50 of sintered metal.
Since bores 30, 45 and 49 have a relatively large cross-sectional area of flow, cylinder space 26 is vented very quickly. Consequently, piston 20, which continues to be under pressure from the right-hand side, through conduit 44 which again has a large cross-sectional area of flow, can also be moved very quickly to the left. Since at the right-hand side of piston 20, no building up of pressure is needed at the start of the thread cutting operation, as the full pressure has permanently been applied, piston 20 is capable of overcoming without delay even larger resistances to motion, such as caused by static friction.
Toward the end of the motion of piston 20 to the left, damping piston 23 plunges into damping bore 27. The compression of air in damping bore 27, thus the formation of an air cushion, retards the piston. Through notch 24, the air cushion can expand, so that an excessive pressure rise and thus a reversal of the motion of piston 20 are eliminated. While being displaced to the left, piston rod 15 moves thread catcher 6, through link 14, angle lever 12 and link 11, into the needle thread loop which has been engaged and enlarged by rotary hook 3, and takes hold of the needle thread loop portion leading to the work, as well as of the bobbin thread.
Upon stopping the sewing machine in the upper dead center position of needle 4, electromagnet 60 is de-energized through a timing circuit, and valve piston 54 is returned by the compressed air into the position shown in FIG. 2, in which bore 52 is cleared by front face 56 and bore 49 is closed by front face 55. As bore 52 is cleared, cylinder space 26 is pressurized again through conduit 46. Because of throttle 43, a pressure can build up in cylinder space 26 only relatively slowly. As soon as the force acting on large piston portion 22 exceeds the opposite force acting on small piston portion 21, piston 20 starts moving to the right. Thereby, the air taken earlier through throttle valve 36 into the portion of cylinder space 26 at the right-hand side of piston portion 22 is initially compressed and then displaced again through throttle valve 36, so that the movement of piston 20 is braked.
Throttle 43 in conduit 46 and throttle valve 36 in conduit 35 thus produce the effect that piston 20 returns into its initial position 3 at a relatively slow speed. Therefore, thread catcher 6 is also returned to its rest position at a reduced speed. During this return, it pulls the needle and bobbin threads off in a length corresponding to the extent of its travel, and moves them to cutting knife 7 by which the threads are cut through at the end of this step of motion.
Since the second step of motion of thread catcher 6 is effected at a reduced speed, there is no chance that thin and sensitive threads would tear during the thread pulling operation. Piston 20 is moved back against the flow resistance produced by throttle valve 36, so that the full pressure builds up in cylinder space 26 at the left-hand side remote from piston portion 21. Therefore, due to the surface area ratio of piston portions 21,22, a force more than twice as strong is exerted by piston 20 during its motion toward the right, into its rest position, than in the opposite direction. This makes sure that even thick threads will be satisfactorily cut.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
|
A thread catcher of a cutting device in sewing machines is actuated by an air cylinder whose piston has two portions of unequal diameter. The small cylinder space accommodating the smaller-diameter piston portion is permanently pressurized while the larger cylinder space is alternately pressurized and vented. The larger cylinder space portion on its end closer to the smaller piston portion is permanently vented through a conduit. Both this conduit and the conduit for supplying the larger cylinder space include a throttle. The obtained effect is that the first step of motion of the thread catcher is quick and exact in duration, while the second step of motion is slower but performed with a greater force, so that thin threads are prevented from tearing prematurely and thick threads are cut reliably.
| 3
|
This is a division of application Ser. No. 772,964, filed Sept. 5, 1985, now U.S. Pat. No. 4,933,115.
BACKGROUND OF THE INVENTION
The invention relates to a process and an apparatus for the production of a flowable mixture which reacts to form foam from flowable components stored in storage containers. Prior to the metered introduction into a mixing zone at least one of the components is charged with a defined amount of gas by introducing this component and gas separately into a gasification chamber equipped with a hollow stirrer. If gas is required, the gas is sucked in by the hollow stirrer through the hollow shaft thereof, is stirred into the component and is finely divided therein until the desired value is achieved.
With an apparatus of this general type (U.S. application Ser. No. 550,428, filed on Nov. 10, 1983 now abandoned; German Offenlegungsschrift 32 44 037), gasification is carried out in the storage container or in a smaller intermediate container. The air is sucked in by the hollow shaft inside the container directly from the gas space. The suction opening of the hollow shaft is thus located beneath the lid inside the gas space. The density measuring device switches on the stirrer mechanism by means of a control device in order to stir in gas when the lower tolerance threshold of the desired density value is exceeded, and switches it off again when the upper tolerance threshold is reached. This arrangement has the disadvantage that the stirrer mechanism can no longer be used for homogenizing the component located in the container because it is and must be switched off from time to time.
Segregation then occurs in the case of components containing additives which tend to settle. Continuous circulation is also important for keeping the temperature uniform.
The object of the present invention was to improve the apparatus in such a way that components containing additives which tend to settle and components which have to be kept at a uniform temperature can be circulated continuously for the purpose of homogenization.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an apparatus with supply of gas for gasification from the gas space of the storage container,
FIG. 2 shows an apparatus with an external gas source, and
FIG. 3 shows a section of a modification to the apparatus according to FIG. 2.
DESCRIPTION OF THE INVENTION
The above object is achieved according to the invention in that the component is circulated from the storage container through the gasification chamber and back into the storage container. The gas sucked in by the hollow stirrer is maintained at a pressure at least equal to the prevailing pressure in the storage container. The component fraction remaining in the storage chamber is also homogenized during those periods in which gasification does not take place.
In this manner, the gasification and homogenization processes have been separated. This means that the component can be circulated continuously in the storage container, for example by means of a stirrer mechanism, in order to avoid sedimentation and to keep the contents of the container at a uniform temperature even if, from time to time, gasification does not take place.
According to a particular embodiment of the new process, the gas is drawn by suction from the gas space of the storage container.
Storage containers for such components are generally kept under a preliminary pressure, generally of the order of from 2 to 5 bar. For this purpose, compressed air from a compressed air supply is supplied via a pressure regulating valve so that the pressure is kept constant in the container. It is particularly advantageous to remove the gas from the gas space because volatile substances contained in the component can escape from the component and accumulate in the gas space. They are then simultaneously reintroduced into the component during the gasification process.
According to one particular embodiment, the gas is taken from an external gas source and the pressure level in the gasification chamber is made to equal the pressure level of the gas supplied. Using this method, it is possible to carry out gasification either at the safe pressure as that prevailing in the storage container or at a higher pressure level. The gasification process can be carried out correspondingly faster under a higher pressure level, i.e. more gas is absorbed by the component per unit time.
The new apparatus for producing the flowable mixture compression storage containers containing a gas space, wherein supply lines lead from the storage containers via metering pumps to a mixer head, with the supply system of at least one component being provided with a gasification container having a hollow stirrer as well as a gas content measuring device which is connected to the stirrer drive by means of a pulse switching device and the hollow stirrer has a suction opening. This apparatus has the disadvantage that the stirrer, due to its design, can operate only during the gasification periods.
The novelty lies in the fact that the stirrer container is arranged in a circulating line which leaves the storage container and reenters it, in which circulating line a conveying pump is provided and in that the suction opening of the hollow stirrer is provided with a gas supply line. This design of the apparatus enables the stirrer mechanism in the storage container to be operated independently of the gasification process.
According to one particular embodiment, the gas supply line is connected to the gas space of the storage container. In this way, the gas can be sucked from the gas space of the storage container just as advantageously as with the apparatus described in the above-identified U.S. application.
According to an alternative embodiment, the gas supply line is connected to an external gas source.
Two different operating methods are possible with this arrangement: Firstly, the pressure of the external gas source can be adjusted to the preliminary pressure in the storage container and, in the second case, a pressure higher than that in the storage container can prevail.
The gas supply line is preferably provided with a pressure regulator having a connection to the section of the circulating line leading into the storage container.
Pressure variations in the system can be compensated using this pressure regulator.
According to a further particular embodiment, the gas supply line and the section of the circulating line arranged between the gasification chamber and the storage container are joined to each other via a pressure balancing piston. This arrangement has the advantage that the pressure in the gasification chamber is automatically adapted to the pressure of the gas supplied from an external gas source. The pressure in the gasification chamber can be kept above the pressure level in the storage container so that gasification takes place more rapidly.
One embodiment has proven particularly advantageous, according to which the circulating line enters the gasification chamber at the level of the stirring elements of the hollow stirrer. By means of this arrangement, the air introduced is immediately mixed with the newly supplied component which means that the air is dispersed particularly quickly and intensively.
A further particular embodiment has proven advantageous, in particular for gasifying filler-containing components, according to which embodiment a rinsing line leads back to the storage container from the base of the gasification chamber, the base, which is preferably conical in shape, being located above the maximum filling level of the storage container.
Since fillers, such as glass fibers, often tend to settle, the above method prevents deposits in the stirrer container. The rinsing line is optionally provided with a stop-valve which is, however, preferably always open when processing filler-containing components. This rinsing line either enters the storage container directly or indirectly by joining the section of the circulating line leading to the storage container. This rinsing line does, of course, only have a small cross-section so that the considerably larger portion of the gasified component leaves the gasification chamber via the returning section of the circulating line. The conical base ensures that settling particles move more quickly towards the outlet of the rinsing line.
The novel apparatus is illustrated purely diagrammatically in the drawing with reference to two embodiments and is described in more detail below.
In FIG. 1, components A and B pass from storage containers 1, 2 via supply lines 3, 4, metering pumps 5, 6 and change-over valves 7, 8 to a mixing head 9. In order to circulate the components, circulating lines 10, 11, which lead back to the storage containers 1, 2, branch off from the change-over valves 7, 8. Gas spaces 12, 13 and stirrer mechanisms 14, 15 are arranged in the storage containers 1, 2. The storage container 1 is provided with a gasification device 16. It consists of several elements: A circulating line 18 leads from the base 17 of the storage container 1 and reenters the storage container 1 at the top 19. A gas content measuring device 20 (density measuring device according to document number 6100 belonging to the company Josef Heinrichs Meβgerate, D-5000 Cologne 41), a conveying pump 21 as well as a small stirrer mechanism container (or gasification chamber) 22 are arranged in succession in this circulating line 18. The stirrer mechanism of the stirrer mechanism container 22 consists of a drive 23 and a hollow stirrer 24 equipped with a stirring element 33, the suction opening 25 of said hollow stirrer 24 communicating with the gas space 12 of the storage container 1 via a gas supply line 26. The gas supply line 26 enters an annular chamber housing 27 which surrounds the hollow stirrer 24 at the level of the suction opening 25 in a sealing manner. The circulating line 18 enters the stirrer container 22 laterally at the level of the stirring element 33. A connection 28 which can be shut off and which is connected to a compressed gas source which is not shown is also provided on the storage container 1. A section 18a of the circulating line 18 extends between the stirrer mechanism container 22 and the storage container 1. The gas content measuring device 20 is connected via a pulse line 29 to a desired value comparator 30 which is designed as a pulse switching device and switches the drive 23 of the hollow stirrer 24 on and off as required via a pulse line 31. The drive 32 for the stirrer 14 of the storage container 1 can be driven independently thereof. The stirrer mechanism container 22 has a conical base 34 which tapers into an outlet 35, from which a rinsing line 36 with a shut-off valve 37 leads back into the supply container 1 and enters it above the maximum filling level. It has a considerably smaller cross-section than section 18a.
In FIG. 2, components A and B pass from storage containers 41, 42 via supply lines 43, 44, metering pumps 45, 46 and change-over valves 47, 48 into a mixing head 49. In order to circulate the components, circulating lines 50, 51, which lead back to the storage containers 41, 42, branch off from the change-over valves 47, 48. Gas spaces 52, 53 and stirrer mechanisms 54, 55 are arranged in the storage containers 41, 42. A gasification device 56 is connected to the storage container 41. It consists of several elements: A circulating line 58 leads from the base 57 of the storage container 41, reenters the storage container 41 at the top 59 and passes into the lower region thereof. A gas content measuring device 60, a conveying pump 61 as well as a small stirrer mechanism container (a gasification chamber) 62 are arranged in succession in this circulating line 58. The stirrer mechanism of the stirrer mechanism container 62 consists of a drive 63 and a hollow stirrer 64 whose suction opening 65 is connected, via a gas supply line 66, to an external gas source 52a (compressed air supply). A pressure reducing valve or pressure maintaining valve which are not shown may also be provided in some cases. The gas supply line 66 enters an annular chamber housing 67 surrounding the hollow stirrer 64 in a sealing manner at the level of the suction opening 65. A pressure-balancing piston 68 is arranged between the section 58a of the circulating line 58 extending from the stirrer mechanism container 62 and the storage container 41 and the gas supply line 66. The gas content measuring device 60 is connected via a pulse line 69 to a desired value comparator 70 designed as a pulse switching device which switches the drive 63 of the hollow stirrer 64 on and off as required via a pulse line 71. The drive 72 of the stirrer 54 of the storage container 41 can be driven independently thereof. The storage container 41 is connected via a supply line 73, which can be shut off, to a compressed air supply, which is not shown.
The apparatus according to FIG. 3 differs from the apparatus according to FIG. 2 in that the balancing piston 68 is eliminated. Instead, there is arranged in the gas supply line 81 a pressure regulator 82 which detects the pressure prevailing in the line section 84 via a connection 83 and accordingly adjusts the pressure of the air to be supplied to it. In other respects, this embodiment corresponds to the embodiment shown in FIG. 2.
The invention is further illustrated, but is not intended to be limited by the following examples in which all parts and percentages are by weight unless otherwise specified.
EXAMPLES
Process Example 1
The apparatus according to FIG. 1 is used. A preliminary pressure of 4 bar is maintained in the storage container 1. In order to prevent the additives contained in component A from settling, the stirrer 14 is driven continuously by the stirrer mechanism 32. The density of the component is used as a gauge of the gas charge. The component is circulated continuously via the circulating line 18 by the conveying pump 21. In a specific ratio, the greater part flows via the line section 18a back into the storage container 1 and the smaller part via the rinsing line 36, in order to avoid deposits at the base 34 of the stirrer mechanism container 16. The density measuring device 20 continuously measures the density of component A under the set pressure of 4 bar and transmits the measured value via pulse line 29 to the desired value comparator 30. If the measured density value exceeds the specified desired value of 0.93 g/cm 3 , the desired value comparator sets the stirrer mechanism drive 23 into operation via the pulse line 31 so that the hollow stirrer 24 produces a vacuum and sucks gas from the gas space 12 of the storage container 1 via the suction opening 25, the annular chamber housing 27 and the gas supply line 26. During gasification, the density of the component falls again and, when the desired value is reached, the desired value comparator 30 emits a pulse to switch off the stirrer mechanism drive 23. It goes without saying that the desired value has a certain tolerance spectrum and transmits the pulses to the stirrer mechanism drive 23 when the upper or lower threshold value is reached. Apart from prolonged rest periods, the metering pumps 5, 6 operate continuously and meter the components A and B via the change-over valves 7 and 8 into the mixer head 9 or convey them via the return lines 10 and 11 back into the containers 1 and 2.
Process Example 2
The apparatus according to FIG. 2 is used. The components A and B stored in the storage containers 41 and 42 under a pressure of 4 bar are circulated continuously by the stirrers 54 and 55. The conveying pump 61 arranged in the circulating line 58 circulates component A continuously. The density of component A is measured continuously by means of the density measuring device 60. The measured value is supplied to the desired value comparator 70 via a pulse line 69. A desired density value of 0.93 g/cm 3 is specified. If a rise in density occurs, the stirrer drive 63 is actuated via the pulse line 71 when the upper tolerance threshold of the desired value is attained. Compressed air is conveyed from the external gas source 52a via the gas supply line 66 to the suction opening 65 of the hollow stirrer 64 which sucks in this air and finely divides it in the component. The compressed and is subjected to a pressure of 5 bar. The pressure-balancing piston 68 ensures that the pressure is equalized between the compressed air supplied and the component issuing from the stirrer mechanism container 62 so that a pressure of 5 bar also prevails in the stirrer mechanism container 62. Gasification takes place in a substantially shorter period than in Process Example 1 owing to the higher pressure level in the stirrer mechanism container 62. Components A and B are conveyed via the supply lines 43 and 44 from the metering pumps 45 and 46 via the change-over valves 47, 48 into the mixer head 49 or they pass via the return lines 50 and 51 back into the storage containers 41 and 42 if the change-over valves 47 or 48 are in the appropriate position.
Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
|
The present invention relates to an improved apparatus for the production of a flowable mixture which reacts to form foam from flowable components stored in storage containers, wherein prior to metered introduction into a mixing zone, at least one of the components is charged with a defined quantity of gas, by (i) introducing said one component and gas separately into a gasification chamber equipped with a hollow stirrer, (ii) sucking gas into said component through the hollow shaft of the hollow stirrer, and (iii) stirring the gas into the component, until the desired value is attained, the improvement wherein (a) the component is circulated from the storage container through the gasification chamber and back into the storage container, (b) the gas sucked through the hollow shaft of the hollow stirrer being maintained at pressure at least equal to the pressure prevailing in the storage container, and (c) the component fraction remaining in the storage container is homogenized during those periods in which gasification does not take place.
| 8
|
CROSS REFERENCE TO RELATED APPLICATION
This application is related to copending application Ser. No. 540,800, filed Jan. 14, 1975, entitled "Baling Press with Replaceable Wear Strips and Replaceable Liner and Control Therefor."
BACKGROUND OF THE INVENTION
This invention relates generally to a baling press used in compressing loose material to effect a reduction in volume and form the material into a block or bale of a predetermined size, and specifically to a door arrangement for the loading chute for such a press.
Baling presses are used to produce compressed bales of synthetic polymeric materials from loose tacky synthetic crumb. The use of hydraulic baling presses for this general purpose has been well known.
Typically in prior art baling presses the bolster performing compression of the crumb material reciprocates vertically, and the loose crumb material is loaded into the press cavity prior to compression through the same opening used to discharge the compressed material. A retractable chute is used to supply the loose crumb material to the press cavity through the single opening, and the chute is then retracted so as to allow discharge of the compressed material.
SUMMARY OF THE INVENTION
The present invention generally provides an improved baling press which uses separate loading and unloading openings so that the press may operate faster, and specifically provides a door arrangement which will automatically allow or prevent flow of material through the loading opening during the various cycles of the pressing operation.
The basic press structure comprises a cavity, having separate loading and unloading openings near its opposite ends, and in which a bolster moves to reduce the volume of the cavity and compress the material loaded therein, to a predetermined size, e.g., a bale. The loading opening includes a chute through which loose material, such as loose tacky synthetic polymeric crumb, can pass into the cavity. A ram is connected to reciprocate the bolster within the cavity between a retracted position clear of the loading opening and an advanced position beyond the loading opening.
The loading chute need not be moved out of the way during the compression step, and by having the loading opening near one end of the chamber, in the upper wall of the press cavity, and the unloading opening near the other end, the improved press utilizes a faster, smoother "flow through" technique. Substantial compression of the crumb material will not occur until the bolster has moved past the supply opening, so that the door, which is used to control the flow of material through the loading opening, is not subjected to the forces produced during compression of the material.
In order to prevent in-flow of the material during the compressing and discharging operations the door closes off the loading opening. A cooperating cam and follower means is used to close the door automatically during the beginning of the compression step, and to open the door as the bolster returns to its retracted position. Preferably, the cam is mounted to reciprocate with the ram, while the follower is connected by linkage to the door to control the motion of the door. The cam design is such as to allow the door to close quickly, but seat slowly, to prevent excessive wear which would occur if the door was continually slammed shut.
It is therefore an object of this invention to provide an improved baling press having a door arrangement for its loading opening which will automatically close the door in response to predetermined compressing movement of the ram to stop further flow of loose material through the loading opening.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view, with a portion broken away and shown in section, showing the major components of a typical baling press incorporating the features of the invention;
FIG. 2 is a plan view of the press as shown in FIG. 1; and
FIG. 3 is an enlarged view, partially in elevation and partially in cross-section, of the door arrangement for the loading chute employed in the press shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, and particularly to FIGS. 1 and 2, the press structure consists of extended side plates 10 and 12 which are connected at opposite ends with a plurality of through bolts designated by the general reference numeral 14. A bottom plate 15 and a top plate 16 are held in place by additional studs 17, extending between the side plates and appropriately fitted thereinto.
As seen in FIG. 1, the bottom plate 15 extends from the bale discharge opening 20 between the side plates, rearwardly or to the left to the retracted position of the bolster 22. In this position, the face 23 of the bolster is vertically aligned with the rearward edge of the loading opening or feed chute 25, which communicates with the press cavity 26 through a pivoting door 27. The upper plate 16 is shorter, and extends from the plane of one edge of the discharge 20 rearwardly to the edge of the feed chute 25.
Appropriate keys (not shown), comprising longitudinally tapered strips, are tapped into place after bolts 17 are tightened so as to exert an upward pressure on bottom plate 15 and a downward pressure on top plate 16, and allow replaceable liner pieces to be used to line the sides of cavity 26. Details of the replaceable liner pieces and key strips form the subject matter of related U.S. Patent application, Ser. No. 540,800.
The press head 35 is supported between the side plates 10 and 12, spaced on the opposite side of the bale discharge or unloading opening 20, and a vertically movable cover or gate 36 is supported at the top of the discharge, capable of moving vertically from its open position, as shown in FIG. 1, to a closed position where one face 37 of the gate functions as an end wall of the cavity 26.
Movement of the gate 36 is guided by roller 38 which operates in a track 39 that is supported on the center of the head 35. In addition, cooperating wedges 41, on the gate, and 42, on the head, are arranged to contact each other in the closed position of the gate, firmly supporting it against the thrust of material being compressed in the cavity by the movement of the bolster 22.
The bolster 22 is driven by a double acting hydraulic ram which is shown at 45, and the gate 36 is operated by a double acting hydraulic cylinder 47. The door 27 is moved between its open and closed positions by a means discussed in more detail hereinafter.
In a normal cycle of operation, gate 36 is closed, the cavity is filled with a measured charge of material which is fed to the cavity via the feed chute 25, and ram 45 moves the bolster 22 forward, while the door 27 is closed, and compresses the material within the cavity 26 against the gate 36. The stroke of the ram is halted when the material is compressed to the desired thickness within the end of the cavity at the gate 36. In the case of crumb synthetic polymers, the pieces are sufficiently tacky that they adhere together and form an essentially self-supporting block or bale. The gate is then withdrawn upwardly, and ram 45 moves the bolster further forward until its face 23 aligns with the edge of the cavity at the discharge opening 20. The gate 36 then is moved downwardly by cylinder 47, functioning to push the compressed block or bale of material down and away from the discharge 20, and to wipe it from the face of the bolster in the event there is any sticking of the bale to the face. This same motion again moves the gate to its closed position and the ram 45 withdraws the bolster to its starting position as shown in FIG. 1. Details of the complete cycle and the supply of crumb to the press, as from a scale, are disclosed in said copending application, Ser. No. 540,800, filed Jan. 14, 1975.
In order for the door 27 to open automatically, so that material will flow into cavity 26 via feed chute 25, and to close automatically so that further flow of material is prevented when the bolster 22 begins its compression stroke, a cam and follower arrangement connected to door 27 by linkage means is provided as shown in FIG. 3. Door 27 is mounted to the press by hinge 50, so that door 27 will pivot about hinge 50 from the closed position (FIG. 3) to the open position (FIG. 1). In the closed position, door 27 forms a part of the upper wall to cavity 26, while in the open position, door 27 forms part of feed chute 25.
Identical cams 51 are located on either side of ram 45 and are attached by bolts 52 to the rear of bolster 22. In this way cams 51 will reciprocate with ram 45. Followers 54 ride in the cams 51, and comprise rollers 55 carried at the end of short arms 56. Arms 56 are connected by linkage 60 to door 27 and cause the door to open and close in response to the movement of follower 54 in cam 51.
Linkage 60 comprises long arms 62 angularly and fixedly connected to arms 56. Both the short and long arms pivot about pivot pins 63, which are suitably mounted on the press frame. Arms 62 are joined together by a cross arm 64, so that arms 62 will work together, and are pivotally connected to door 27 by rods 66 which have pivotal connections 67 at one end to arms 62, and at their other ends 68 to door 27.
Cam 51 is designed to close door 27 quickly as ram 45 begins moving from its retracted position (FIG. 1) to its advanced position (not shown) in its compression stroke. But, the cam is also designed so that door 27 will seat slowly once it's in the closed position to prevent door 27 from being worn excessively by continually being slammed shut. Because the press is designed for operation at a comparatively rapid rate, for example in the order of three bales per minute, rapid seating of the door will result in quick wear. Therefore, the actual seating of the door is done relatively slowly compared to the closing of the door. Further, since substantial compression of the material will not occur until the bolster has moved past the supply opening 25, it is not necessary that the door form a perfect seal.
As shown in FIG. 3, the cam 51 comprises channel or slot 70 receiving the roller 55 of the follower 54. Channel 70 includes three shapes or cam surfaces which together describe an essentially S-shaped curve having an elongated lower end. The first part 73 of channel 70 is approximately convex and causes the door 27 to move rapidly from the open position (FIG. 1) to an almost closed position. The second part 74 has a reverse curvature and causes door 27 to become seated. The final segment 75 is connected to segment 74, is straight and maintains the door 27 in the closed position while the pressing operation is completed. When follower 54 is in the straight portion 74, the bolster 22 will be in the extended positions, i.e., compressing and discharging the bale.
The pressing operation begins with the bolster 22 in the retracted position and the cam follower 54 initially resting in the upper portion 73 of the camming channel 70. The door 27 is in the open position shown in FIG. 1, and the gate 36 covers discharge opening 20. As the compression stroke begins, hydraulic force is applied to ram 45 causing bolster 22 and cams 51 to move axially, i.e., left to right as shown in FIG. 3, into cavity 26. As cams 51 move, cam followers 54 will move down cam portions 73 to cam portions 74. As followers 54 move downward, so do arms 56 to which followers 54 are attached, causing long arms 62 to swing about pivots 63. The movement of arms 62 causes door 27 to pivot about hinge 50 from the open to the closed position. As follower 54 moves through cam portion 74, arms 56 and 62 turn about pivots 63, but at a slower rate because of the slope of segment 74. This slowing movement seats the door 27 at a slower rate than it was closed so as not to slam it shut. Once linear segment 75 is reached, all movement of arms 56 and 62 has ceased and the door 27 is closed. The length of segment 75 is not critical, but is at least long enough to hold the door closed until the leading edge of the bolster had cleared it.
When the bolster 22 is moved from the extended or advanced position to the retracted position, the movement of the cam will be the reverse of that described above. The door 27 will quickly move from the closed position to the open position, and then slowly seat in the wall of the feed chute 25 from which position the door 27 started. The door 27 will thereafter remain in the open position until a new cycle and forward movement of the bolster 22 is started.
While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus and that changes may be made therein without departing from the scope of the invention.
|
A baling press including a cavity, having separate loading and unloading openings near its opposite ends, a bolster which moves in the cavity to reduce the volume of the cavity and compress the material loaded therein to a predetermined size, a ram connected to reciprocate the bolster within the cavity between a retracted position clear of the loading opening and an advanced position beyond the loading opening, and a door linked to a cooperating cam and a follower means mounted one to reciprocate with the ram and the other to control the motion of the door whereby movement of the bolster from its retracted position to its advanced position in a compression stroke will automatically close the door until the bolster returns to its retracted position.
| 1
|
[0001] This invention relates to a blanket having a slit through which a person's feet may protrude. The blanket is designed for singles, couples or multiple persons sharing a blanket. The individuals sharing the same blanket can protrude their feet or keep them inside the blanket.
BACKGROUND
[0002] All commercial blankets today come as a whole sheet. Some individuals, however, want to expose their feet when sleeping especially during summer while keeping their bodies covered. For these individuals, the only option is to pull the blanket upwards to expose their feet. While this is a solution, because of the size of the standard blankets, it is still a struggle to keep the feet exposed at all times. Further, the problem is accentuated when two or more individuals with different preferences are sharing the same blanket. It would be difficult for one to keep his or her feet in the blanket while the other individual keeps his or her feet exposed. The blanket of this invention addresses this problem.
[0003] It is an object of this invention to provide a blanket that will keep an individual's feet out of the blanket but keeps his or her body covered.
[0004] It is also an object of this invention to provide a blanket that will cater to one's preference of keeping his or her feet out while the other individual/s sharing the same blanket keep their feet inside.
SUMMARY OF THE INVENTION
[0005] This is related to a blanket having a slit for exposing a foot while keeping the other parts of the body covered. The blanket is made of a fabric material having a top surface, a bottom surface with the peripheral edges preferably protected from frilling. The core of the invention is the slit forming an opening resembling an open bottom pocket located across the top surface of the fabric. This slit is formed by overlapping pieces of fabric materials. The overlap of the pieces of fabric material is preferably 12 to 15 inches in length to keep the exposed feet uncovered while sleeping but at the same time keep the covered feet covered. This amount of overlap will also prevent air from drafting into the blanket. The width of the slit is preferably the same as that of a mattress sized for the blanket. For example, for a twin size blanket the width of the slit will be the same as the width of a twin mattress. The width can be narrower than the width of the mattress, however, it should not be less than 15 inches. A narrower slit would not comfortably accommodate an individual's feet unless it is desired to custom make the blanket so that only one foot has to be exposed while keeping the other foot covered. In the latter case, the slit may be narrower than 15 inches. The blanket may be made from one layer or multilayer of fabric materials and may have different geometric shapes aside from four sided such as rectangular or square.
[0006] There are generally two ways of assembling the slitted blanket from a piece or pieces of fabric materials. One way is to cut pieces of fabric materials, usually at least two, to a desired dimension; overlapping the pieces of fabric material that would serve to cover the body; and, sewing these overlapping pieces of fabric material together at each lateral side of the overlap to form an open bottom pocketlike opening. If the area of the pieces of fabric material joined together is not large enough, matching pieces of fabric material may be sewn on each lateral side of the main pieces of fabric material to widen the blanket. If the width of the slit or opening is too wide, one may narrow this by sewing together, horizontally along the slit, a portion of the overlapping fabric materials to a desired dimension. The peripheral edges are preferably protected from frilling by methods known in the art such as trimming, hemming, overlocking and overlapping a strip of fabric on the exposed edges.
[0007] The other way of assembling the slitted blanket is by cutting a piece of fabric material conforming to a desired size and shape of the blanket; cutting a slit of a desired width across a desired position on the piece of fabric material thereby forming a top slit and a bottom slit; and, sewing a piece of fabric material having a length of at least 12 inches and a width matching the width of the slit to the bottom slit to form an opening resembling an open bottom pocket. The preferable ranges of the width of the opening and the length of the overlap is as described above. Also as above, it is preferable to protect any exposed edges of the blanket from frilling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a perspective view of the blanket as it is used.
[0009] [0009]FIG. 2 is an exploded view of how the pieces are sewn together to form the blanket with a slit with an overlapping section shaded for illustration purpose.
[0010] [0010]FIG. 2A shows the bottom overlap as a shaded area underneath the top surface of a finished blanket.
[0011] [0011]FIG. 3 is an exploded view of another method of forming the slit with an overlap on a blanket.
[0012] [0012]FIG. 3A is an exploded view of another method of making the slitted blanket from a one piece starting material.
[0013] [0013]FIG. 4 shows how the pieces are sewn together underneath.
[0014] [0014]FIG. 4A shows overlocking on the edges or borders.
[0015] [0015]FIG. 5 is an exploded view of assembling a slitted blanket from two pieces of fabric sewn on the sides to limit the length of the slit.
[0016] [0016]FIG. 5A shows the finished blanket assembled according to FIG. 5.
DESCRIPTION OF THE INVENTION
[0017] [0017]FIGS. 1 and 2 show the blanket with a slit 10 , hereinafter referred to plainly as blanket, as it is used by a couple, one preferring to put her feet under the blanket while the other preferring to keep his feet uncovered. The blanket 10 as shown here is generally rectangular in shape having a top surface 11 , a bottom surface 12 , and borders 13 a - f. Other shapes are known and used. The peripheral edges or borders 13 a - f of the blanket 10 are preferably protected from frilling off, that is, threads being unwoven and detaching from the fabric, by means known in the art such as trimming with pinking shears or edging scissors, hemming, overlocking or by overlapping a strip of fabric along the peripheral edges or borders of the fabric.
[0018] The blanket may be made of one layer or a multilayer of fabric material. The fabric material suitable for making a blanket is known and is dependent on the weather condition, for example, a thin sheet of cotton is preferable for warm weather while wool and quilted multilayer of fabric are preferable for the cold weather. The kind of fabric may be natural, man-made, synthetic or blended. The blanket may be plain or with design.
[0019] The slit 14 of the blanket runs horizontally across the top surface 11 of the blanket, preferably, with the width 15 of the slit the same as the width 16 of the mattress 17 as shown in FIGS. 1 and 2A. For example, for a twin size blanket, the width 15 of the slit 14 will be approximately 39 inches since this is the usual width of a twin size mattress. For a full size, it is approximately 54 inches, for a queen size, 60 inches and for a king or California king, 72-76 inches. The recommended minimum width of the slit is 15 inches because this would comfortably accommodate only one person's feet protruding from the slit. The important feature of this invention is the design of the slit 14 . The slit is not just a plain opening cut across the top surface of the blanket but rather, the slit is designed to form an opening that looks like a pocket with an open or unsewn bottom. To more clearly describe the slit 14 , it is further identified as having a top 18 lip and bottom lip 19 . The top lip 18 does not align with the bottom lip 19 but has corresponding overlapping sections as shown in FIGS. 1, 2A, 3 , 3 A, 5 and 5 A. The bottom section extending outwards from lip 19 is hereinafter referred to as bottom overlap 20 and this section is shaded to assist in describing the slit. The bottom overlap 20 ranges from 12 to 15 inches in length with a width matching the width of the slit which is preferably the same as the width of the mattress. FIG. 1 shows the location of the overlapping section on the blanket with dash lines with the bottom overlap 20 shaded to differentiate this from the corresponding overlapping section at the top surface of the blanket. Note that the bottom overlap 20 is underneath the feet of the individual who wants his/her feet exposed while the individual who wants his/her feet covered has these underneath or covered by the bottom overlap 20 , that is, the feet are fully covered under both the top and bottom 20 overlapping sections. An overlapping section that has a length of 12-15 inches allows the exposed feet to be exposed all the time while keeping the covered feet, fully covered. With this amount of overlap, the exposed feet laying over the bottom overlap 20 will be kept exposed because it will be not be so easy, although not impossible, to go under the overlap. The covered feet, on the other hand, will be kept covered because the weight of the exposed feet keeps the bottom overlap 20 in place. The length of the overlap is preferably not less than 12 inches because a shorter length will allow the air to draft into the blanket 10 , thereby causing discomfort for the person who wants his/her feet covered. Note that one can also use this blanket with a little bit of adjustment for keeping one foot exposed while keeping another foot covered.
[0020] [0020]FIG. 2 shows one easy way to assemble or make the blanket 10 . Four pieces of fabric, A-D, are cut and sewn together. To form the slitted top surface 11 , a proximal end section 21 of A and a distal section 22 of B are sewn together on both lateral sides to form the open pocketlike slit wherein the top lip 18 would be on the top surface and exposed while the bottom lip 19 would be inside and underneath the top surface. The distal section 22 , shaded for illustration, forms the bottom overlap 20 underneath the top surface 11 , therefore the length of this section should be 12-15 inches. The top lip 18 is bordered by 13 f while the bottom lip 19 is bordered by 13 e. The inside lateral side 23 of piece C is then sewn with an inside lateral side of A and the opposite inside lateral side of A is sewn with the inside lateral side 24 of piece D in a manner shown in FIG. 4. The inside lateral sides of A are formed after end sections 21 and 22 are sewn together. The interconnection of the pieces of fabric in the methods described herein are done in the same manner as shown in FIG. 4. After sewing the pieces together, the edges 25 are preferably overlocked to prevent frilling as shown in FIG. 4A. Other means to prevent frilling as described above can also be used. In use, pieces C and D would normally overlay and hang along the lateral sides of the bed depending upon its widths. The width of pieces C and D are normally obtained by subtracting the standard width of the mattress from the standard width of the blanket. For example, in a twin size blanket having a width of 65 inches, the preferred size or width of the slit of 39 inches is subtracted from 65 to give a difference of 26 inches. Therefore, the width of C would be 13 inches and the width of D would be 13 inches. The length of pieces C and D would normally be the same as the length of a standard twin which is approximately 90 inches. This holds true for the other sizes such as full, queen and king, as well. The widths of the blankets are typically 62-66 inches for twin, 72-80 inches for full, 90-92 for queen and king while the widths of the mattresses are typically 39 inches for twin, 54 inches for full, 60 inches for queen, 76 inches for king and 72 inches for California king. The above method of attaching or connecting pieces like C and D on both sides of another piece like piece A shown here, as well as protecting the edges or borders from frilling are also applicable to all similar steps that will be described hereafter, therefore, these methods will not be repeatedly described in detail. FIG. 2A shows the finished blanket 10 with the bottom overlap 20 shaded to illustrate the pocketlike opening.
[0021] Another method of assembling the blanket 10 as shown in FIG. 3 is to simply cut a slit on piece E, protect the resulting top slit 26 from frilling by methods known in the art, typically by overlapping a strip of fabric 27 on top slit 26 and sewing a piece F to the bottom slit 28 , the piece F having the dimensions of the bottom overlap 20 as described above. Pieces G and H are sewn on each lateral side of E in the same manner as pieces C and D are sewn to the lateral sides of A. This same method can be applied to a one piece starting material I as shown in FIG. 3A. Here, there are no separate pieces like G and H to be sewn to E as shown in FIG. 3. Rather, after the slit is cut on I, the same methods as described above for protecting the edges of the cut slit from frilling and for sewing the bottom overlap 20 to the resulting bottom slit 28 are followed. This latter method would work well for blankets that are not four sided but are of different geometric shapes such as circle, oval, and the like.
[0022] An alternative easy method of assembling this blanket 10 is by simply overlapping two pieces of fabric J and K by an amount of 12 to 15 inches in length as shown in FIG. 5. The lateral edges 29 and 30 of the overlapping sections are sewn together. The desired width of the slit is formed by sewing together from both lateral edges 29 and 30 , that portion 31 with portion 32 and portion 33 with portion 34 running horizontally along the width of the slit. A stitching 35 is preferably sewn laterally as shown in FIGS. 5 and 5A to segregate the slit from the non-slit sections of the blanket. As in the other methods of assembling the blanket, the bottom overlap is identified as 20 to show correlation of the alternative methods of producing the pocketlike opening which is a core feature of the invention.
[0023] The blanket described here may be lined with another fabric material by methods known in the art so long as the slit is maintained according to the design described above.
[0024] The method of choice for assembling the blanket is at the discretion of the manufacturer. Other ways may be used but blankets having the pocketlike slit opening as described is within the scope of this invention.
[0025] While the embodiment of the present invention has been described, it should be understood that various changes, modifications and adaptations may be made therein without departing from the spirit of the invention and the scope of the appended claims. Those skilled in the art will recognize that other and further variations of the features presented herein are possible. The scope of the present invention should be determined by the teachings disclosed herein, the appended claims and their legal equivalents.
|
This invention relates to a blanket having a slit through which a person's feet may protrude. The blanket is designed for singles, couples or multiple persons sharing a blanket. The individuals sharing the same blanket can protrude their feet or keep them inside the blanket. The slit is not just a plain opening or cut across the top surface of the blanket but rather, the slit is designed to form an opening that looks like a pocket with an open or unsewn bottom.
| 0
|
CROSS-REFERENCES TO RELATED CASES
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 09/738,282, filed on Dec. 14, 2000, which is a continuation of Ser. No. 09/426,060, filed Oct. 22, 1999, now U.S. Pat. No. 6,266,462, which is a continuation-in-part of Ser. No. 09/022,413, filed Feb. 12, 1998, now U.S. Pat. No. 6,021,237, which claims priority to Korean Application No. 97-24796, filed Jun. 6, 1997.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention generally relates to a method of preparing optical fiber with low polarization dependence for use in acousto-optic applications, and, more particularly, to an acousto-optic filter employing such a fiber to reduce polarization-dependent loss (PDL) in the filter.
[0004] 2. Discussion of Related Art
[0005] As an optical signal traverses an optical network, the signal is subject to losses and nonlinear effects that result in signal attenuation and distortion. Amplifiers, such as erbium-doped fiber amplifiers (“EDFA's”), are typically placed approximately every 80 kilometers along an optical fiber to boost signal strength. However, such amplifiers impose their own distortions on the signal power spectral distribution (as a function of wavelength). One of the major distortions is caused by the non-uniform gain profile (as a function of wavelength) of the amplifiers, which imposes a non-uniform spectral distribution on the amplified signals. It is especially important in wavelength division multiplexed (“WDM”) networks to maintain a uniform spectral distribution across all channels.
[0006] Static filters are often used to attenuate the signal power as a function of wavelength to achieve a substantially uniform power distribution. Static filters, however, cannot adapt to dynamically changing conditions such as amplifier aging, temperature variations, channel add/drop, fiber loss and other changes in components along the transmission line. Moreover, the required filter shape is dependent upon system configuration e.g. the spacing between amplifiers. Static filter characteristics cannot be modified to compensate for these changes without replacing the filter itself.
[0007] To overcome these problems, it is known in the art to employ dynamic wavelength tunable filters to flatten or equalize the signal spectrum, as well as to obtain any desired spectral shape. One such filter is an all-fiber acousto-optic tunable filter (“AOTF”) described in U.S. Pat. No. 6,233,379, entitled “Acousto-optic filter,” which is assigned to the assignee of the present invention and incorporated by reference herein. As described in the patent, the all-fiber AOTF is a multiple notch filter, with a transfer function characterized by notch depth and center frequency (or wavelength).
[0008] One problem with the all-fiber AOTF is that the effect of the filter on light in the fiber is polarization dependent. For example, although the filter may attempt to place a notch at one desired center frequency, the notch will effectively be placed at a different center frequency for each polarization splitting one notch into two. The relative frequency shift between the polarization-dependent notches causes a difference between the transmissions of the different polarizations through the filter as a function of frequency, which results in a polarization-dependent loss in the filter. It is desired to reduce the polarization dependence of light in optical fiber, and to thereby reduce PDL in an all-fiber AOTF.
SUMMARY OF THE INVENTION
[0009] This invention relates to a method of making optical fiber having low polarization dependence and an acousto-optical filter, generally of the kind described in U.S. Pat. No. 6,266,462, with low PDL. A section of the fiber is heated and then allowed to cool. At least the heating is controlled to reduce stresses in a cladding layer surrounding a core of the interaction length after the interaction length is allowed to cool to reduce polarization dependence of the cladding layer. At least time and temperature of heating may be controlled.
[0010] The optical fiber may be used for constructing an acousto-optical filter. The filter includes a support, and first and seconds mounts at spaced locations on the support. The optical fiber has first and second mounted portions secured to the first and second mounts respectively. An exposed section of the fiber is heated and cooled between the first and second mounted portions. A signal generator is operable to generate a periodic signal. An electro-acoustic transducer has a terminal connected to the signal generator and an actuating portion, the electric signal causing vibration of the actuating portion, and the actuating portion being connected to the interaction length so that the vibration generates a transverse wave traveling along the interaction length. Such a filter has the ability to reduce an amplitude of one or more selected wavelengths of light as the light travels through the interaction length.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention is further described by way of example with reference to the accompanying drawings wherein:
[0012] [0012]FIG. 1 is a side view illustrating manufacturing of optical fiber;
[0013] [0013]FIG. 2 is a side view illustrating severing of a length of optical fiber manufactured according to the process shown in FIG. 1;
[0014] [0014]FIG. 3 is a cross-sectional side view of an interaction length of the severed length of the optical fiber of FIG. 2;
[0015] [0015]FIG. 4 is a view similar to FIG. 3 after a section of a jacket of the optical fiber is stripped;
[0016] [0016]FIG. 5A is a cross-sectional end view on 5 - 5 in FIG. 4 illustrating stresses in a cladding layer of the interaction length;
[0017] [0017]FIG. 5B is a cross-sectional plan view through a section of the optical fiber;
[0018] [0018]FIG. 6 is a side view illustrating apparatus that is used to anneal the cladding layer of the interaction length;
[0019] [0019]FIG. 7 is a cross-sectional side view of an acousto-optical tunable filter according to an embodiment of the invention;
[0020] [0020]FIG. 8 is a side view illustrating functioning of the filter;
[0021] [0021]FIG. 9 is a view similar to FIG. 7 illustrating coupling of x-polarized light into the cladding layer;
[0022] [0022]FIG. 10 is a view similar to FIG. 9 illustrating coupling of y-polarized light into the cladding layer;
[0023] [0023]FIG. 11 is a graph illustrating transmission of x-polarized light and y-polarized light through a core of the fiber, both before and after annealing; and
[0024] [0024]FIG. 12 is a graph illustrating PDL before and after annealing.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Optical fiber fabrication typically consists of two major steps: preform fabrication and fiber drawing. There are a number of different methods for preform fabrication, such as modified chemical vapor deposition (MCVD), outside vapor deposition (OVD), and vapor-phase axial deposition (VAD). FIG. 1 shows a preform that is manufactured utilizing the MCVD technique. The process is initiated with a silica tube 12 , which eventually forms an outer cladding layer of a fiber. An inner cladding material 14 is deposited on an inner surface of the silica tube 12 , and eventually becomes an inner cladding layer of the fiber. A core material 16 is deposited on the inner cladding material 14 .
[0026] A heat source 18 is located near an end of the preform 10 . The heat source 18 heats the end of the preform 10 to approximately 2000° C. to melt it. Rollers 20 engage with material melted out of the end of the preform 10 . The rollers 20 rotate, thereby drawing an optical fiber 24 out of the preform 10 . As the fiber is drawn, a polymer jacket material (not shown) is coated on the fiber. The optical fiber 24 shown here is a single-mode fiber which is composed of the materials 12 , 14 , and 16 , and is rolled into a roll 26 .
[0027] In FIG. 2, a length 28 of the fiber 24 is paid out from the roll 26 and cut from the remainder of the fiber on the roll 26 for the purpose of constructing an optical filter according to the invention. FIG. 3 illustrates in cross section a portion of the severed length 28 . The optical fiber includes a glass core 30 made of the core material 16 , a cladding layer 32 surrounding the core 30 , wherein the cladding layer itself may include an inner cladding layer 32 A surrounding the glass core 30 , and an outer cladding layer 32 B surrounding the inner cladding layer 32 A. A jacket 34 surrounds the cladding material 32 B.
[0028] As part of the process of constructing a filter according to the invention, a portion of the jacket 34 is removed to expose a section 36 of the fiber. A number of techniques may be employed to remove the jacket, including mechanical stripping and exposure to hot sulfuric acid, among others. FIG. 4 illustrates the severed length 28 after a portion of the jacket is stripped from the section 36 . First and second portions 38 A and 38 B of the jacket remain on the cladding layer 32 . The portions 38 A and 38 B are located on opposing sides of the stripped section 36 .
[0029] In order to achieve guiding characteristics, the core 30 is designed to have a higher refractive index than the cladding region by adding impurities such as GeO 2 and P 2 O 5 to the SiO 2 basis of the core material 16 . Such impurities in the core 30 not only create the required refractive index difference with respect to the cladding 32 A and 32 B, but also make the coefficient of the thermal expansion (CTE) and the melting temperature different from that of the cladding. Therefore, when the preform is fabricated in a high temperature of approximately 2000° C. and cooled down to room temperature, a significant amount of stress is generated in the core 30 and the cladding 32 A and 32 B. This inherent stress is called “thermally-induced stress”.
[0030] Moreover, when the preform 10 is pulled to the optical fiber 28 at the drawing tower, the optical fiber is exposed to a drawing tension of typically 100-1,000 N, and this stress becomes frozen in the optical fiber 28 while the optical fiber 28 is cooled down to room temperature. Therefore, an additional stress field is created in the optical fiber, which is called “mechanically-induced stress.”
[0031] [0031]FIGS. 5A and 5B show the combined stress profile. The core is under axial, radial and tangential tensile stress. The cladding 32 A and 32 B is under radial tensile stress and under axial and tangential compressive stress. There is thus a discontinuity of the stress field in the core-cladding interface.
[0032] According to the invention, the cladding layer 32 of the stripped section 36 is then annealed utilizing an apparatus 50 , as shown in FIG. 6. The apparatus 50 may employ, for example, a modified CW-200 Fused Coupler/WDM workstation sold by Lightel Technologies, Inc. of Kent, Wash. The apparatus 50 includes a support structure 52 , first and second attachment formations 54 and 56 respectively, a flame nozzle 58 , and a hydrogen source 60 .
[0033] The attachment formation 54 is rigidly secured to the support structure 52 . The attachment formation 56 is movably secured to the support structure 52 . The hydrogen source 60 is connected to the flame nozzle 58 . The flame nozzle 58 is secured to the support structure 52 for movement between the attachment formations 54 and 56 .
[0034] In use, the portions 38 A and 38 B of the jacket 34 are attached to the first and second attachment formations 54 and 56 , respectively. A force F is applied, which tends to move the attachment formation 56 away from the attachment formation 54 , thereby creating a tension in the stripped section 36 .
[0035] Hydrogen from the hydrogen source 60 flows to the flow nozzle 58 and is lit at an exit from the flame nozzle 58 to create a flame 64 . The nozzle 58 and the flame 64 are located above the stripped section 36 so as to heat the stripped section 36 from above. Hydrogen may be preferred to any other source of fuel because hydrogen combustion does not produce carbon or hydrocarbon byproducts that may deposit on the cladding layer 32 . Those skilled in the art will recognize that electro-resistive and other heating sources may be employed in the present invention instead of the hydrogen flame described in this example.
[0036] The nozzle 58 moves in a direction 66 parallel to the longitudinal axis of the stripped section 36 . The advancing flame 64 heats areas of the stripped section 36 as those areas are exposed to the flame 64 . Heating of the stripped section 36 is primarily due to radiation from the flame 64 . Regions of the stripped section 36 trailing the flame 64 are allowed to cool. Cooling of the stripped section 36 is primarily due to convection of the heat to ambient air. The force F compensates for heat-induced elongation of the stripped section 36 by moving opposing ends of the stripped section 36 apart. The fiber is heated and cooled without the core 30 expanding by more than 20%.
[0037] The effect of heating and cooling the stripped section 36 is that the cladding 32 A and 32 B is annealed. Fiber formed by modified chemical vapor deposition has stress characteristics that are particularly conducive to the beneficial effects of this process.
[0038] The flame 64 may be in the range 1-20 mm wide as measured along the stripped section 36 . The flame 64 may be held at a distance of 0.1-5 mm, or, or more particular 0.5-5 mm from the stripped section 36 . Movement of the flame in the direction 66 may be at a speed of 1-50 mm per second, or, more particularly, 1-10 mm/s. The stripped section 36 may be heated to a temperature between 500-1300° C., and, more particularly, to between 800-1000° C. The force F may be in the range 0.05-0.5 N, or, more particularly, 0.05-0.15 N, maintained substantially constant.
[0039] [0039]FIG. 7 of the accompanying drawings illustrates an acousto-optic filter 120 constructed according to an embodiment of the invention. The filter 120 is of the kind described in U.S. Pat. No. 6,266,462, issued Jul. 24, 2001, which is incorporated herein by reference. The filter 120 includes a mounting construction 122 , the severed length 28 of the optical fiber, and an electrical signal generator 130 .
[0040] The mounting construction 122 includes a heat sink 132 , an acoustic wave generator, such as a piezo-electric transducer 134 , an acoustic wave propagation member 136 , such as an aluminum horn, an outer tube arrangement 138 , and an end plug 140 .
[0041] Gold terminals are sputtered on opposing surfaces of the piezo-electric transducer 134 . One terminal is located against the heat sink 132 and attached to the heat sink 132 . The base of the acoustic wave propagation member 136 is then attached to an opposing terminal of the piezo-electric transducer 134 .
[0042] Openings are made in the heat sink 132 , piezo-electric transducer 134 , and acoustic wave propagation member 136 to form a continuous passage. The end of the severed length 28 having the portion 38 A of the jacket is inserted through the opening of the acoustic wave propagation member 136 , whereafter it is inserted through the openings in the piezo-electric transducer 134 and the heat sink 132 .
[0043] The portion 38 B of the jacket is then located in a groove in the end plug 140 . A resin is then placed in the groove and allowed to cure, thereby securing the portion 38 B of the jacket to the end plug 140 .
[0044] Resin is also applied to the interaction length 37 where it protrudes from a tip 150 of the acoustic wave propagation member 136 , and flows into the tip 150 of the acoustic wave propagation member 136 . The resin then cures and secures the interaction length 37 to the tip 150 of the acoustic wave propagation member 136 .
[0045] A damper 152 is located on the optical fiber 142 . The damper 152 is coaxially disposed on the stripped section 36 adjacent the portion 38 B of the jacket. The length of exposed fiber from the tip 150 to the end of the damper 152 nearest the tip 150 is the “interaction length” 37 of the filter. Generally, the interaction length or “interaction region” is the length of fiber in which light is coupled from one mode to another, and, more particularly in this case, the portion of the exposed section 36 not covered by the damper 152 .
[0046] An end 154 of the outer tube arrangement 138 is then located over the portion 38 B of the jacket and moved over the end plug 140 until it contacts a surface of the heat sink 132 . A second, opposing end 156 of the outer tube arrangement 138 is located over the end plug 140 . The positioning of the end plug 140 is then adjusted within the end 156 . By adjusting the positioning of the end plug 140 , the interaction length 37 of the optical fiber 142 is tensioned by about 0.2 N to eliminate slack. When a predetermined tension in the interaction length 37 is reached, a resin is applied to an interface between the end plug 140 and the end 156 . The resin is allowed to cure, thereby securing the end plug 140 stationarily within the end 156 . The tension of the interaction length 37 is thereby set.
[0047] The signal generator is connected to the transducer 134 through leads 160 and 162 . The lead 160 couples to the heatsink 132 , which is itself electrically coupled to a terminal on one face of the transducer 134 . The lead 162 is electrically connected to the opposing face of the transducer 134 , either directly to the terminal on the opposing face, or indirectly through the acoustic wave propagation member 136 . The heat sink 132 and the acoustic wave propagation member 136 can be made of conductive aluminum so that the terminals on the opposing sides of the piezo-electric transducer 134 are at the voltages of the leads 160 and 162 , respectively. A voltage potential is thereby created across the piezo-electric transducer 134 .
[0048] The signal generator 130 applies across the piezo-electric transducer 134 a voltage at one or more frequencies in the range 0-20 MHz, or more particularly 0-3 MHz. The voltage signal applied across the piezo-electric transducer 134 causes opposing surfaces of the piezo-electric transducer 134 to vibrate relative to one another in a direction transverse to a longitudinal axis of the interaction length 37 . Adjusting the frequency and amplitude of the electrical signal applied to the transducer results in a corresponding change in the frequency and amplitude, respectively, of the mechanical vibration of the transducer. Those skilled in the art will recognize that the invention may employ acoustic wave exciters other than the acoustic wave exciter formed from the combination of the signal generator 130 , acoustic wave generator 134 and acoustic wave propagation member 136 described herein.
[0049] Vibrations of opposing surfaces of the piezo-electric transducer 134 are transferred through the acoustic wave propagation member 136 to the tip 150 thereof. The tip 150 vibrates periodically in response to the change in the voltage. Movement of the tip 150 is transferred to the end of the interaction length 37 closest to the tip 150 .
[0050] [0050]FIG. 8 illustrates how vibration of the tip 150 imposes acoustic waves in the interaction length 37 . In the present example, the waves are y-direction transverse flexural waves that travel along the interaction length 37 from the tip 150 to the damper 152 . The damper 152 is designed to absorb the waves or otherwise minimize reflection of the waves back to the tip 150 . The creation of a standing wave is thereby prevented.
[0051] In use, the filter 120 is inserted into a fiber optic transmission line. A light signal is transmitted through the core 30 . The light signal may be modulated as a WDM signal having many channels, each at a different wavelength. For various reasons, including the non-uniform gain profiles of amplifiers along the fiber optic transmission line, the intensity of light may differ from channel to channel at the point where the light enters the optical fiber 142 of the filter 120 .
[0052] The effect of the acoustic waves in the interaction length 37 is that the intensity of selected wavelengths of light traveling through the interaction length 37 is attenuated by coupling these wavelengths from a mode in the core into one or more modes in the cladding layer 32 of the interaction length 37 . This coupling creates a notch in the transmission spectrum centered at each selected wavelength. By changing the frequency of the applied electrical signal, and thus the frequency of the acoustic waves in the interaction length 37 , the center wavelength of the notch can be altered . Furthermore, by changing the magnitude of the applied voltage (and thereby the magnitude of the acoustic wave), the depth of the notch (representing the amount of light coupled to the other mode) can be changed. By cascading multiple acoustic exciter/interaction length combinations and/or applying multiple acoustic frequencies with each exciter, a combination of notches of different optical center frequencies and depths may be achieved, thereby allowing creation of a desired filter transfer-function as described in Ser. No. 09/738,282. Such a filter may be employed for gain equalization purposes. Those skilled in the art will recognize that, as an alternative to coupling light between core and cladding modes, an AOTF may also couple light between different core modes. Further details of the functioning of the filter 120 are described in U.S. Pat. No. 6,266,462 referenced above.
[0053] [0053]FIGS. 9 and 10 illustrate how light is coupled into the cladding layer 32 after application of an acoustic wave. These figures are for conceptual purposes only, and do not necessarily reflect the actual intensity distribution in the fiber. Light traveling in the core mode in the core 30 couples into both an x-polarized cladding mode including regions 70 and 72 in the cladding 32 (as shown in FIG. 9), and into a y-polarized cladding mode including regions 80 and 82 (as shown in FIG. 10). X-polarized and y-polarized components of light traveling in the core couple preferentially into corresponding x-polarized and y-polarized cladding modes, as shown in FIGS. 9 and 10, respectively. The arrows in FIGS. 9 and 10 indicate the direction and phase differences of the polarization of the light in each mode.
[0054] The center wavelength λ 0 of light coupling into the cladding layer 32 is a function of the index of refraction β of the material of the cladding layer 32 . At different points in the fiber, stress in the cladding layer changes the index of refraction β to an effective index of refraction β eff which is different from the index of refraction β without any stress in the cladding layer 32 . As a result of this stress-induced change in refractive index, the center wavelength λ 0 shifts, and is thus also recognized as a function of stress in the cladding layer 32 .
[0055] Referring to FIGS. 5A and 5B, there is a larger tensile stress in the x-direction than in the y-direction. The larger tensile stress in the x-direction results in an effective index of refraction in the x-direction β eff-x which differs from the index of refraction β of the cladding layer 32 with no stress therein. The effective index of refraction in the y-direction β eff-y is however substantially equal to the index of refraction β of the cladding layer 32 without stresses in the cladding layer 32 . The effective index of refraction in the x-direction β eff-x is thus different from the effective index of refraction in the y-direction β eff-y due to the tangential stresses 40 . Light coupling from the core 30 to x and y polarized modes, as shown in FIGS. 9 and 10, will thus be coupled at different center wavelengths, λ 0-x and λ 0-y .
[0056] [0056]FIG. 11 illustrates how the filter of FIG. 7 filters light when the stresses are not reduced as in FIG. 5. Wavelengths λ are shown on the abscissa and transmission T through the core 30 is shown on the ordinate. It can be seen that there is a relatively large difference between the center notch wavelength of x-polarized light λ 0-x and the center notch wavelength of y-polarized light λ 0-y .
[0057] Annealing the cladding layer 32 , as discussed with reference to FIGS. 5A and 5B, causes a reduction in tensile stress in the x-direction. A reduction in tensile stress in the x-direction causes a reduction in the stress difference between the x- and y-directions and a corresponding reduction in the difference between the effective index of refraction in the x-direction β eff-x and effective index of refraction in the y-direction β eff-y . There is also a corresponding reduction in the difference between the center wavelengths of x-polarized light λ 0-x and y-polarized light λ 0-y , respectively. Referring again to FIG. 11, annealing causes the center notch wavelength of the x-polarized light λ 0-x to move towards the center notch wavelength of y-polarized light λ 0-y as indicated by the arrow. This reduction in the difference between the center notch wavelengths indicates a reduction in the polarization dependence of light coupling into the cladding layer, along with a corresponding reduction in the PDL of the filter.
[0058] [0058]FIG. 12 illustrates the extent to which PDL is reduced. The PDL of the filter is defined by the following formula:
PDL=|T x −T y |,
[0059] where T x is transmission of x-polarized light and T y is transmission of y-polarized light through the core 30 . The PDL before annealing is represented by line 74 and the PDL after annealing is represented by line 76 . The PDL before annealing is as much as 4 decibels (dB) before annealing, and less than 1.0 dB, or, more particularly, less than 0.5 dB, after annealing.
[0060] While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative and not restrictive of the current invention, and that this invention is not restricted to the specific constructions and arrangements shown and described, since modifications may occur to those ordinarily skilled in the art.
|
This invention relates to a method of making optical fiber having low polarization dependence and an acousto-optical filter with low PDL. A section of the fiber is heated and then allowed to cool. At least the heating is controlled to reduce stresses in a cladding layer surrounding a core of the interaction length after the interaction length is allowed to cool to reduce polarization dependence of the cladding layer. Preferably, at least time and temperature of heating is controlled.
| 6
|
TECHNICAL FIELD
[0001] The invention relates to a process for preparing electrospun fiber tubular material using electrospinning technology and particular collecting template, and to electrospun fiber tubular material prepared with the same. The invention belongs to the field of electrospun fiber tubular material.
BACKGROUND ART
[0002] Along with the industrial development and technological advancement, electrospinning technology is gaining more and more attention. As a simple and effective process for preparing nano-/micro-scale fiber materials, electrospinning has been widely used in such fields as biomedical materials, tissue engineering, photoelectric materials, filtering materials, sensors and the like. Electric technology involves formation of a jet from a solution or melt of a polymer or other material in high-voltage electric field, ejection of the jet from a solution-storing unit during which the solvent evaporates and the jet solidifies, and finally deposition of the solidified jet on a receiving unit to form nano-/micro-scale fiber assemblage.
[0003] Tubular fiber materials have been widely used in biomedical and certain industrial fields, and still have promising prospect of further development, especially in tissue engineering such as blood vessels, nerves, etc., where tubular fiber materials play a vital role as scaffold materials. Tissue engineering imposes certain demands on the macro-configuration and micro-morphology of three-dimensional tubular fiber materials in practical use. For example, for a particular organ or tissue, certain tubular fiber materials with particular macro-configuration and size are needed to fit the contour of the organ or tissue. On the other hand, certain tubular fiber materials with particular micro-morphology are needed to facilitate the adherence and differentiation of particular cells. For different organs or tissues, besides a network of tubular fiber material having a structure of communicating channels as required by blood vessel tissue engineering, the angle, number, size, etc. of channel furcation(tube furcation) vary according to practical demand. Therefore, preparation of tubular fiber materials with controllable macro-configuration and micro-morphology is of great significance in biological tissue engineering and a variety of industrial applications. Generally, tubular fiber materials of certain size may be collected controlling electrospinning process parameters and a roller assembly. However, both macro-configuration and micro-morphology thereof are limited to some extent. For example, due to the limitation of the roller assembly, controllable macro-configuration can not be achieved in terms of the size, tube end closure, etc. of the tubular fiber material. On a micro scale, fibers are generally arranged randomly or oriented to the degree only along the circumference, and no complex and controllable micro-morphology can be formed in a controllable way. In addition, conventional processes are just limited to the preparation of a single-channel structure, unable to produce electrospun fiber materials having a structure of complex communicating channels, letting alone control of the complex channel structure. Thus, it is still blank up to date in the area of preparing three-dimensional tubular fiber material with controllable macro-configuration and micro-morphology using electrospinning.
SUMMARY OF THE INVENTION
[0004] The object of the invention is to provide a process for preparing electrospun fiber tubular material as well as electrospun fiber tubular material prepared using the same, wherein the process comprises the following specific steps:
(1) formulating a solution or melt for the electrospinning process, wherein the solution or melt for the electrospinning process is known to those skilled in the art; particularly, the formulation method may be any reported conventional electrospinning process; the material used to prepare the solution or melt may be a polymer, inorganic material or composite material; and there is no limitation on the material on condition that it does not limit the object of the invention; (2) loading the solution or melt into an electrospinning fluid supplying unit, wherein the solution or melt may be alternatively formulated in the electrospinning fluid supplying unit directly as known to those skilled in the art; (3) immobilizing one or more metal rod templates or a metal rod combined-template, as a collecting unit, on an auxiliary planar substrate connected with a low-voltage earth terminal, wherein the collecting unit may be assembled according to any conventional method in the art of electrospinning; the object of the invention may also be achieved by only using the template without the use of any auxiliary planar substrate; the template may be solid or hollow; and in the case of being hollow, there is no limitation on the shape and size of the template on condition that the outer wall of the template is kept intact; (4) controlling the flow rate of the electrospinning solution or melt in the range of 0.1-300 ml/h, the distance between the spinneret as the high-voltage terminal and the collecting unit in the range of 1-100 cm, and the voltage provided by the high voltage generator during electrospinning in the range of 1-80 kv; (5) collecting the electrospun fiber tubular material on the metal rod templates or the metal rod combined-template and removing it therefrom.
[0010] The electrospinning fluid supplying unit (including the spinneret therein), the high voltage generator and the low-voltage earth terminal may be arranged according to any conventional method in the art of electrospinning.
[0011] The metal rod template or the metal rod combined-template includes:
(1) a single metal rod template; and (2) a two-dimensional or three-dimensional metal rod combined-template having an intersecting structure(cross structure) which is formed by combining single metal rod templates, wherein the intersecting angel lies between 10°-90°, and more than two single metal rod templates are combined.
[0014] The two-dimensional or three-dimensional metal rod combined-template may be designed to be a disassemble or undisassemble collecting template.
[0015] The surface of a removable singe metal rod template may be designed to have a hole compatible with the size of a secondary removable template. The hole may be an intersecting through-hole or closed at one end. Single metal rod templates may be combined by intersecting one another in different directions.
[0016] The single metal rod template, including those in the two-dimensional or three-dimensional metal rod combined-template, has the following features or a combination thereof:
(1) The metal material used in the single metal rod template may be conductive metal material and conductive metal alloy material, including copper, iron, aluminum and alloys thereof. (2) The single metal rod template may be column-shaped or noncolumn-shaped or a combination thereof, such as a taper, a combination of columns of various sizes, a combination of a taper and a column, etc. (3) The length of the single metal rod template may be tailored in the range of 0.5-50 cm. Adjustment may be made by those skilled in the art according to practical need. For example, a length in the range of 0.05-0.5 cm is permitted for a template. A preferred length is in the range of 0.5-30 cm. (4) The cross-sectional shape of the single metal rod template may be any regular or irregular shape, such as triangle, square, rectangle, pentacle, circle, etc. (5) The size of the cross-section of the single metal rod template may be in the range of 0.005-30 cm based on the circumcircle diameter of the cross-section. (6) The surface of the single metal rod template may be smooth or have a particularly patterned microstructure, wherein the particularly patterned microstructure is a grid collecting structure or a raised collecting structure.
[0023] The grid collecting structure is formed by weaving grid wires of various radial sizes using various weaving methods. The radial size of the grid wires is in the range of 0.1-5 mm, and the space between the grid wires is in the range of 10-1000 μm. The grid may be woven in a series of different ways such as single weaving, double weaving and the like.
[0024] The raised portion of the raised collecting structure comprises protrusions on the surface of the single metal rod template. The height of the protrusions may be tailored in the range of 10-5000 μm. The raised portion may be designed to form raised dot collecting template (the protrusions are composed of dots with a combination of shapes such as square, rectangle, circle, star, etc.), raised line collecting template (the protrusions are lines, i.e. composed of a combination of straight lines, arc lines and line segments) and raised dot-line collecting template (the protrusions are composed of a combination of dots and lines of various shapes). The non-raised portion may be conductive or insulating.
[0025] According to the process of the invention, the metal rod template or the metal rod combined-template as described above may be used successfully to prepare a series of nano-/micro-scale tubular fiber materials with controllable macro-configuration and micro-morphology, comprising:
(1) single tubular fiber materials; and (2) two-dimensional or three-dimensional tubular fiber materials having a structure of communicating and intersecting channels, wherein the intersecting angle lies between 10°-90°; the communicating structure of the channels in the fiber assemblage may be a thoroughly communicating structure such as crisscross-shaped and X-shaped structure, or a structure which is open at one end and closed at the other, such as T-shaped structure and Y-shaped structure; and various amounts of tubular fiber materials may be combined to form different two-dimensional and three-dimensional network structures.
[0028] The single tubular fiber material, including those in the two-dimensional or three-dimensional tubular fiber materials having a structure of communicating and intersecting channels, has one or a combination of the following features:
(1) The single tubular fiber material may be a polymeric, inorganic or composite material. (2) The single tubular fiber material may have a shape of column-shaped channel, non-column-shaped channel or a combination of column-shaped and non-column-shaped channel, such as a three-dimensional channel configuration of taper, a combination of columns of various sizes, a combination of a taper and a column, etc. (3) The single tubular fiber material may have a length in the range of 0.5-50 cm, dependent on the length of the template. In other words, a length in the range of 0.05-0.5 cm is also permitted. The preferred length is in the range of 0.5-30 cm. (4) The cross-sectional shape of the single tubular fiber material may be any regular or irregular shape, such as triangle, square, rectangle, pentacle, circle, etc. (5) The size of the cross-section of the single tubular fiber material may be in the range of 0.005-30 cm based on the circumcircle diameter. (6) The surface morphology of the single tubular fiber material may be an unorderly non-woven structure, or have a particularly patterned microstructure.
[0035] Compared with conventional collecting methods in electrospinning, the process of the invention provides unexpected results by designing and using the collecting templates as described above, which may be explained by way of the following mechanism. During electrospinning, fiber is forced by the high-voltage field to move toward the collecting template. Wherever the structure of the collecting template changes, the direction of the electric field force changes accordingly to redirect the fiber toward the surface of the three-dimensional collecting template. In this electric field with varying direction, the fiber is deposited on the surface of the collecting template from different directions to form a tubular fiber material rather than only on a planar template as in conventional electrospinning to form a two-dimensional thin film.
[0036] At the same time, a planar auxiliary substrate and a rod-like auxiliary template (especially the latter) are incorporated into the invention to diversify the deposition routes of the electrospun fibers, successfully avoiding both concentrated deposition of fibers on the top of the three-dimensional collecting template and suspension of fibers from the root of the three-dimensional collecting template. As a result, the structural integrity and uniformity of the three-dimensional tubular fiber material are enhanced effectively (see FIG. 1 ). Specifically, as a fiber approaches the collecting template under the electric field force, the electrostatic charges on the fiber surface will induce opposite charges to the collecting template. The attraction between unlike charges brings about Coulomb force therebetween. Since Coulomb force is inversely proportional to the square of the distance between charges (F=kqQ/r 2 , wherein F represents Coulomb force, and r represents the distance between two unlike charges, i.e. the space between a fiber and the collecting template), and a fiber segment is more close to an adjacent protrusion than to the other area of the template, the fiber prefers to deposit on the protrusion under the relatively larger Coulomb force therebetween. Different segments of a fiber may be attracted by different protrusions, so that the fiber may deposit on and thus is suspended between different protrusions. The suspended fiber is drawn by Coulomb forces from different directions into an oriented arrangement between protrusions.
[0037] The features of the invention include:
(1) The three-dimensional configuration of the fiber material may be controlled by the macro-configuration of the single three-dimensional collecting template. The fiber mainly deposit on the surface of the three-dimensional collecting template. The macro-configuration of the tubular fiber material closely resembles and is mainly determined by the contour configuration of the three-dimensional collecting template. (2) The deposition position and arrangement pattern may be controlled by the patterned microstructure on the collecting template surface. Fibers are mainly deposited on protrusions, and fibers suspended between protrusions feature well-oriented arrangement. (3) The three-dimensional communicating channel structure of the fiber material may be controlled by the way in which removable three-dimensional collecting templates are combined and the network structure thus formed. The fibers mainly deposit on the surface of the combined disassemble three-dimensional collecting templates. The communicating channel structure of the fiber material closely resembles and is mainly determined by the network structure of the three-dimensional collecting template. (4) Several electrospun fiber tubular materials having the same or different macro-configurations and patterned microstructures may be prepared concurrently by batch production of combined templates.
[0042] According to the invention, while making use of conventional electrospinning technology and suitable starting materials and processes, electrospun fiber tubular material with controllable macro-configuration and micro-morphology has been prepared by designing and using a collecting template with controllable macro-configuration and micro-morphology. Furthermore, the structure and morphology of the tubular material may be controlled by designing the macro-configuration and patterned microstructure of the template. Thus, the practical application of electrospinning is more promising, especially in the field of biomedical material, tissue engineering, photoelectric material, filtering material, sensors, etc. which have higher demand on material morphology.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIG. 1 is a schematic view showing the operational principles of electrospinning and the three-dimensional collecting template according to the invention, wherein 1 represents a high voltage generator and controller, 2 represents a flow rate controlling pump, 3 represents an electrospinning solution or melt supplying unit, 4 represents a spinneret of electrospinning, 5 represents electrospun fiber tubular material, 6 represents a rod-like template, and 7 represents a planar auxiliary substrate.
[0044] FIG. 2 is a schematic view showing several column-shaped collecting templates having different three-dimensional configurations.
[0045] FIG. 3 is an optical photo of side view showing the electrospun fiber tubular materials of different diameters as obtained according to Example 1.
[0046] FIG. 4 is an optical micrograph of top view showing the electrospun fiber tubular materials of different diameters as obtained according to Example 1, wherein the insertion is a magnified SEM image of the electrospun fiber tubular materials.
[0047] FIG. 5 is an optical photo showing the electrospun fiber tubular material having a longer length as obtained according to Example 2.
[0048] FIG. 6 is an optical photo showing the electrospun fiber tubular materials having different cross-sectional shapes as obtained according to Example 3.
[0049] FIG. 7 is an optical photo showing the electrospun fiber tubular materials with one end closed as obtained according to Example 4.
[0050] FIG. 8 is a schematic view showing several non-column-shaped collecting templates having different three-dimensional configurations.
[0051] FIG. 9 is an optical photo showing the electrospun fiber tubular materials having different configurations as obtained according to Example 5.
[0052] FIG. 10 is a schematic view showing a three-dimensional collecting template having a patterned microstructure on its surface.
[0053] FIG. 11 is an optical photo showing the electrospun fiber tubular material having a patterned micro-morphology as obtained according to Example 6.
[0054] FIG. 12 is a SEM image showing the electrospun fiber tubular material having a patterned micro-morphology as obtained according to Example 6.
[0055] FIG. 13 is an optical photo showing the three-dimensional electrospun fiber tubular material having two different patterned micro-morphologies as obtained according to Example 7.
[0056] FIG. 14 is an optical photo showing one of the patterned micro-morphologies in the three-dimensional electrospun fiber tubular material as obtained according to Example 7.
[0057] FIG. 15 is an optical photo showing the other patterned micro-morphology in the three-dimensional electrospun fiber tubular material as obtained according to Example 7.
[0058] FIG. 16 is a schematic view showing a three-dimensional collecting template having four patterned microstructures on its surface.
[0059] FIG. 17 is an optical photo showing the three-dimensional electrospun fiber tubular material having four different patterned micro-morphologies as obtained according to Example 8.
[0060] FIG. 18 is an optical photo showing the unfolded three-dimensional electrospun fiber tubular material having four different patterned micro-morphologies as obtained according to Example 8.
[0061] FIG. 19 is a schematic view showing the specific experimental steps for preparing a three-dimensional electrospun fiber material having a communicating channel structure controlling electrospinning process parameters and a disassembble three-dimensional combined collecting template.
[0062] FIG. 20 is a schematic view showing the disassembble three-dimensional combined collecting templates having different intersecting structure(cross structure)s according to Examples 9-12.
[0063] FIG. 21 is an optical photo showing the three-dimensional electrospun fiber material having a crisscross-shaped intersecting and communicating channel structure as obtained according to Example 9.
[0064] FIG. 22 is an optical photo showing the three-dimensional electrospun fiber material having a T-shaped intersecting channel structure as obtained according to Example 10.
[0065] FIG. 23 is an optical photo showing the three-dimensional electrospun fiber material having an X-shaped intersecting channel structure as obtained according to Example 11.
[0066] FIG. 24 is an optical photo showing the three-dimensional electrospun fiber material having a Y-shaped intersecting channel structure as obtained according to Example 12.
[0067] FIG. 25 is a schematic view showing the disassemble three-dimensional combined collecting template having various intersecting structure(cross structure)s according to Examples 13.
[0068] FIG. 26 is a schematic view showing the three-dimensional electrospun fiber material having two branch channels of different configurations connected to the same primary channel as obtained according to Example 13.
[0069] FIG. 27 is a schematic view showing the disassemble three-dimensional combined collecting template having a complex intersecting network structure according to Examples 14.
[0070] FIG. 28 is a schematic view showing the three-dimensional electrospun fiber material having a complex channel network structure as obtained according to Example 14.
[0071] FIG. 29 is an optical photo showing the three-dimensional electrospinning fiber tubular materials as batch-produced according to Example 15 along with the collecting templates.
[0072] FIG. 30 is an optical photo showing the three-dimensional electrospun fiber tubular materials as batch-produced according to Example 15.
[0073] FIG. 31 is a schematic view showing the batch production of three-dimensional electrospinning fiber tubular materials according to Example 16.
[0074] FIG. 32 is a schematic view showing the templates of three-dimensional electrospinning fiber tubular materials according to Example 17.
[0075] FIG. 33 is a schematic view showing the Y-shaped templates of three-dimensional electrospinning fiber tubular materials according to Example 18.
[0076] FIG. 34 is a schematic view showing the three-dimensional electrospinning fiber tubular materials as batch-produced according to Example 20 along with the collecting templates.
DETAILED DESCRIPTION OF THE INVENTION
[0077] The invention will be illustrated with reference to the following examples but is not limited thereto.
Example 1
[0078] A group of cylindrical copper rods with different diameters, namely 0.18 mm, 0.50 mm, 1.36 mm and 3.28 mm, were prepared as three-dimensional templates. This group of cylindrical templates were selected as the collecting substrates for electrospinning. 2 g polycaprolactone (PCL, Mw=5 w) was dissolved in 6 ml N,N-dimethyl formamide (DMF) and 4 ml tetrahydrofuran (THF), and agitated at room temperature to form a homogenous and stable solution. The solution was infused into an injector, the head of which was connected to a high-voltage electric source and used as the high-voltage terminal. The flow rate of the solution was controlled at 0.5 ml/h by a flow rate pump. The applied voltage was 10 kv. The distance(or space) between the high-voltage terminal and the collecting unit was 10 cm. Three-dimensional electrospinning fiber tubular materials, having similar structures to those of the substrates and different diameters, were collected in this process ( FIGS. 2-4 ), wherein the tube diameters were 0.18 mm, 0.50 mm, 1.36 mm and 3.28 mm respectively, and their lengths were 1 cm, 1.3 cm, 1.5 cm and 1.3 cm respectively.
Example 2
[0079] A cylindrical copper wire having a relatively longer length was prepared as a three-dimensional template. The copper wire had a diameter of 0.50 mm and a length of 15 cm. The other parameters were the same as those in Example 1. A three-dimensional electrospinning fiber tubular material, having a similar structure to that of the substrate and a relatively longer length, was collected in this process ( FIGS. 2 and 5 ), wherein the tube diameter was 0.50 mm, and its length was 15 cm.
Example 3
[0080] A group of column-shaped copper rods having different cross-sectional shapes, namely triangle, square and cylinder, were prepared as three-dimensional templates. This group of column-shaped templates were selected as the collecting substrates for electrospinning. The other parameters were the same as those in Example 1. Three-dimensional electrospinning fiber tubular materials, having similar structures to those of the substrates and different cross-sectional shapes, were collected in this process ( FIGS. 2 , 6 ), wherein the tube length was 2 cm.
Example 4
[0081] A group of column-shaped copper rods having one arc-shaped end were prepared as three-dimensional templates. The copper rods had square cross-sections with a side length of 2 mm. This group of column-shaped templates were selected as the collecting substrates for electrospinning. The templates was arranged with the arc-shaped end upward, in proximate to the spinneret. The other parameters were the same as those in Example 1. After spinning, each of the collecting copper rods was pulled out from the non-arc end, so that the structure of the fiber assemblage at the arc end was not impaired. Three-dimensional electrospinning fiber tubular materials, having similar structures to those of the substrates and one closed end, were collected in this process ( FIG. 7 ), wherein the tube lengths were 1.5 cm and 2 cm.
Example 5
[0082] A group of non-column-shaped copper rods having different configurations were prepared as three-dimensional templates. The copper rods were tapers of different taper degrees, or had a combination of cylinders with different diameters at different locations. The other parameters were the same as those in Example 1. After spinning, each of the collecting copper rods was pulled out from the non-arc end, so that the structure of the fiber assemblage at the arc end was not impaired. Three-dimensional electrospinning fiber tubular materials, having similar structures to those of the substrates and different cross-sectional sizes at different locations, were collected in this process ( FIGS. 8 , 9 ), wherein the tube length was 2 cm.
Example 6
[0083] A column-shaped copper rod having patterned microstructure of annular line protrusions on its surface was prepared as a three-dimensional template. The copper rod had a circular cross-section with a diameter of 5 mm, and the space between protrusions was 0.5 mm. This column-shaped template was selected as the collecting substrate for electrospinning. 0.275 g polylactic acid (PDLLA, Mw=45 kDa) was dissolved in 8 ml N,N-dimethyl formamide (DMF) and 2 ml tetrahydrofuran (THF), and agitated at room temperature to form a homogenous and stable solution. The solution was infused into an injector, the head of which was connected to a high-voltage electric source and used as the high-voltage terminal. The flow of the solution was controlled at 0.5 ml/h by a flow rate pump. The applied voltage was 10 kv. The space between the high-voltage terminal and the collecting unit was 10 cm. A three-dimensional electrospinning fiber tubular material, having a similar structure to that of the substrate and a patterned microstructure, was collected in this process ( FIGS. 10-12 ), wherein the tube diameter was 4 mm, and its length was 5 cm.
Example 7
[0084] A column-shaped copper rod having two different patterned microstructures on its surface was prepared as a three-dimensional template. One of the micropatterns was a structure comprising annular line protrusions, wherein the space between the protrusions was 0.5 mm. The other micropattern was a woven grid structure, wherein the grid line had a diameter of 0.1 mm, and the space between the lines was 0.14 mm. The copper rod had a circular cross-section with a diameter of 5 mm. This column-shaped template was selected as the collecting substrate for electrospinning. The other parameters were the same as those in Example 1. A three-dimensional electrospinning fiber tubular material, having a similar structure to that of the substrate and two patterned microstructures, was collected in this process ( FIGS. 13-15 ), wherein the tube length was 1.5 cm.
Example 8
[0085] A column-shaped copper rod having four different patterned microstructures on its surface was prepared as a three-dimensional template. The first micropattern was a structure of smooth flat plate. The second micropattern was a structure comprising square dot protrusions arranged orderly, wherein the side length of each protrusion and the space between the protrusions were both 0.2 mm. The third micropattern was a structure comprising straight line protrusions, wherein the width of each protrusion and the space between the protrusions were both 0.2 mm, and the line protrusions were parallel to the axis of the three-dimensional column-shaped template. The fourth micropattern was a structure comprising straight line protrusions, wherein the width of each protrusion and the space between the protrusions were both 0.2 mm, and the line protrusions were perpendicular to the axis of the three-dimensional column-shaped template. The copper rod had a square cross-section with a diameter of 3 mm. This column-shaped template was selected as the collecting substrate for electrospinning. The other parameters were the same as those in Example 1. A three-dimensional electrospinning fiber tubular material, having a similar structure to that of the substrate and four patterned microstructures, was collected in this process ( FIGS. 16-18 ).
Example 9
[0086] A whole cylindrical copper rod was prepared as a removable three-dimensional collecting template with a diameter of 3 mm. Another cylindrical copper rod with a through-hole (having a size compatible with the above template) was prepared as a fixed collecting template with a diameter of 4 mm. These two templates were assembled in a perpendicularly intersecting relationship to form a disassemble three-dimensional combined collecting template. This combined template was selected as the collecting substrate for electrospinning. The other parameters were the same as those in Example 1.Specific experimental steps were as follows ( FIG. 19 ): (1) assembling the two individual templates into a disassemble three-dimensional combined collecting template before electrospinning and collection; (2) depositing the fiber on the template surface during electrospinning to form electrospun fiber material having a similar structure to that of the substrate and perpendicular communicating channels; (3) pulling out the removable template first after collection; and then (4) removing the three-dimensional electrospun fiber material from the fixed template. A three-dimensional electrospun fiber material, having a similar structure to that of the substrate and crisscross-shaped intersecting and communicating channels, was collected in this process ( FIGS. 20 , 21 ).
Example 10
[0087] A whole cylindrical copper rod was prepared as a removable three-dimensional collecting template with a diameter of 3 mm. Another cylindrical copper rod with a hole (having a size compatible with the above template) closed at one end was prepared as a fixed collecting template with a diameter of 4 mm. These two templates were assembled in a perpendicularly intersecting relationship to form a disassemble three-dimensional combined collecting template. This combined template was selected as the collecting substrate for electrospinning. The other parameters were the same as those in Example 1. The specific steps for moving and removing the electrospinning fiber tubular material were the same as those in Example 9. A three-dimensional electrospun fiber material, having a similar structure to that of the substrate and T-shaped intersecting channels, was collected in this process ( FIGS. 20 , 22 ).
Example 11
[0088] A whole cylindrical copper rod was prepared as a removable three-dimensional collecting template with a diameter of 3 mm. Another cylindrical copper rod with a through-hole (having a size compatible with the above template) was prepared as a fixed collecting template with a diameter of 4 mm. These two templates were assembled at an intersecting angle of 30° to form a disassemble three-dimensional combined collecting template. This combined template was selected as the collecting substrate for electrospinning. The other parameters were the same as those in Example 1. The specific steps for moving and removing the electrospinning fiber tubular material were the same as those in Example 9. A three-dimensional electrospun fiber material, having a similar structure to that of the substrate and X-shaped intersecting channels, was collected in this process ( FIGS. 20 , 23 ).
Example 12
[0089] A whole cylindrical copper rod was prepared as a removable three-dimensional collecting template with a diameter of 3 mm. Another cylindrical copper rod with a hole (having a size compatible with the above template) closed at one end was prepared as a fixed collecting template with a diameter of 4 mm. These two templates were assembled at an intersecting angle of 30° to form a disassemble three-dimensional combined collecting template. This combined template was selected as the collecting substrate for electrospinning. The other parameters were the same as those in Example 1. The specific steps for moving and removing the electrospinning fiber tubular material were the same as those in Example 9. A three-dimensional electrospun fiber material, having a similar structure to that of the substrate and Y-shaped intersecting channels, was collected in this process ( FIGS. 20 , 24 ).
Example 13
[0090] A whole triangular prism copper rod and a whole cone copper rod were prepared as removable three-dimensional collecting templates. A square prism copper rod with both a hole closed at one end and a through-hole was prepared as a fixed collecting template. The three templates were assembled at intersecting angles of 30° and 90° to form a disassemble three-dimensional combined collecting template. This combined template was selected as the collecting substrate for electrospinning. 1.1 g polysuccinate (PBSu, Mw=30 w) was dissolved in 10 ml chloroform (CHCl 3 ), and agitated at room temperature to form a homogenous and stable solution. The solution was infused into an injector, the head of which was connected to a high-voltage electric source and used as the high-voltage terminal. The flow of the solution was controlled at 5.0 ml/h by a flow rate pump. The applied voltage was 60 kv. The space between the high-voltage terminal and the collecting unit was 25 cm. The specific steps for moving and removing the electrospinning fiber tubular material were the same as those in Example 9. A three-dimensional electrospun fiber material, having a similar structure to that of the substrate and two branch channels of different configurations connected to the same primary channel, was collected in this process ( FIGS. 25 , 26 ).
Example 14
[0091] Cylindrical copper rods of different sizes were prepared as single collecting templates, and they were assembled perpendicularly to each other to form a disassemble three-dimensional combined collecting template. This combined template was selected as the collecting substrate for electrospinning. 0.5 ml 1 mol/l hydrochloric acid was added to 50 ml dry ethanol, and then 6.7 g tetraethyl orthosilicate (TEOS), 0.58 g triethyl phosphate (TEP) and 1.48 g calcium nitrate tetrahydrate were added to the solution. After 2 hours of agitation, 5 ml of the resultant sol was added to 5 ml ethanol solution of 1 g polyvinylpyrrolidone (PVP, Mw=3 w) and 0.4 g P123. The resultant solution was agitated for 2 hours and left for later use. The solution was infused into an injector, the head of which was connected to a high-voltage electric source and used as the high-voltage terminal. The flow of the solution was controlled at 0.1 ml/h by a flow rate pump. The applied voltage was 5 kv. The space between the high-voltage terminal and the collecting unit was 2.5 cm. The specific steps for moving and removing the electrospinning fiber tubular material were the same as those in Example 9. A three-dimensional electrospun fiber material, having a similar structure to that of the substrate and a complex channel network structure, was collected in this process ( FIGS. 27 , 28 ). Then this product was sintered to give tubular inorganic bioglass fiber material ( FIGS. 27 , 28 ).
Example 15
[0092] A three-dimensional combined collecting template was prepared for batch production, wherein each individual template was a cylindrical three-dimensional template with a diameter of 0.5 mm and a height of 2 cm. Nine identical individual templates were immobilized on an insulating plate, wherein the space between the templates was 4 cm. The other parameters were the same as those in Example 1. Nine three-dimensional electrospinning fiber tubular materials, each having a similar structure to that of the substrate, were collected in this process ( FIGS. 29 , 30 ). The tubes had a diameter of 0.5 mm and a length of 1.5 cm.
Example 16
[0093] A three-dimensional combined collecting template was prepared for batch production, wherein the individual templates were single collecting templates having different macro-structures and micro-morphologies and disassemble collecting templates having intersecting structure(cross structure)s respectively. Nine individual templates were immobilized on an insulating plate, wherein the space between the templates was 4 cm. 0.1 g wollastonite nanowhisker was first dissolved in 10 ml chloroform (CHCl 3 ), dispersed evenly by ultrasound, added with 1.1 g polysuccinate (PBSu, Mw=30 w), and then agitated at room temperature to form a homogenous and stable solution. The organic/inorganic composite solution was infused into an injector, the head of which was connected to a high-voltage electric source and used as the high-voltage terminal. The flow of the solution was controlled at 25.0 ml/h by a flow rate pump. The applied voltage was 75 kv. The space between the high-voltage terminal and the collecting unit was 60 cm. Nine organic/inorganic composite tubular fiber materials, each having a similar structure to that of its substrate, were collected in this process ( FIG. 31 ). Each single tube had a diameter (circumcircle diameter) of 10 cm and a length of 20 cm.
Example 17
[0094] A group of column-shaped hollow copper rods with different cross-sections were prepared as three-dimensional templates, wherein the cross-sectional shapes of the hollow copper rods included triangle, square and cylinder ( FIG. 32 ). This group of column-shaped templates were selected as the collecting substrates for electrospinning. The other parameters were the same as those in Example 1. Three-dimensional electrospinning fiber tubular materials, having similar structures to those of the substrates and different cross-sectional shapes, were collected in this process, wherein the tube length was 2 cm.
Example 18
[0095] A hollow cylindrical copper rod was prepared as a removable three-dimensional collecting template, wherein the diameter of the template was 3 mm, and the thickness of the tube was 1 mm. Another hollow cylindrical copper rod with a hole (having a size compatible with the above template) closed at one end was prepared as a fixed collecting template, wherein the diameter of the template was 4 mm. These two templates were assembled at an intersecting angle of 30° to form a disassemble three-dimensional combined collecting template. This combined template was selected as the collecting substrate for electrospinning. The other parameters were the same as those in Example 1. The specific steps for moving and removing the electrospinning fiber tubular material were the same as those in Example 9. A three-dimensional electrospun fiber material, having a similar structure to that of the substrate and Y-shaped intersecting channels, was collected in this process ( FIG. 33 ).
Example 19
[0096] A three-dimensional hollow combined collecting template was prepared for batch production, wherein each individual template was a hollow cylindrical three-dimensional template with a diameter of 0.5 mm, a height of 2 cm and a tube thickness of 0.2 mm. Nine identical individual templates were immobilized on an insulating plate, wherein the space between the templates was 4 cm. The other parameters were the same as those in Example 1. Nine three-dimensional electrospinning fiber tubular materials, each having a similar structure to that of the substrate, were collected in this process. The tubes had a diameter of 0.5 mm and a length of 1.5 cm.
Example 20
[0097] A three-dimensional hollow combined collecting template was prepared for batch production, wherein the individual templates were single collecting templates having different macro-structures and micro-morphologies and disassemble collecting templates having intersecting structure(cross structure)s respectively. Nine individual templates were immobilized on an insulating plate, wherein the space between the templates was 4 cm. The other parameters were the same as those in Example 16. Nine organic/inorganic composite tubular fiber materials, each having a similar structure to that of its substrate, were collected in this process ( FIG. 34 ). Each single tube had a diameter (circumcircle diameter) of 10 cm and a length of 20 cm.
|
A method of preparing electrospun fiber tubular material comprises: using single metal rod template or two-dimensional or three-dimensional metal rod combined-template which has cross structure and is composed of the said single metal rod templates to prepare tubular electrospun fiber material by controlling electrospinning process parameters. The method could control the macro-structure and micro-structure of the tubular electrospun fiber material by adjusting template parameters. The tubular electrospun fiber material obtained from the method could be used in such fields as biomedical material, tissue engineering scaffold, photo-electric material, filtering material and sensor etc.
| 3
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a bracket for use in mounting speakers or other equipment to a pole, flat surface, or other structure. In particular, the invention relates to a two-part bracket that allows simple mounting of the equipment to the mounting surface by connecting the two parts of the bracket together.
[0003] 2. The Prior Art
[0004] In order to mount a speaker or other object onto a pole, a pipe clamp is commonly used. The pipe clamp contains a U-bolt that is specifically sized for a single pipe diameter. The U-bolt usually has threaded ends for nuts to provide an extreme clamping force against the pole. One disadvantage of this type of system is that it requires a different pipe clamp for each size of pole. Another disadvantage is that the installer is required to hold the speaker or other object in place and to tighten the bolts at the same time. This operation thus usually requires two people for installation.
SUMMARY OF THE INVENTION
[0005] It is therefore an object of the invention to provide a mounting bracket that can be used to install a speaker or other object on a variety of surfaces of different sizes. It is another object of the invention to provide a mounting bracket that can be used by one person to install the object in a simple and effective manner.
[0006] These and other objects are accomplished by a mounting bracket assembly comprising a stationary bracket to be mounted on a pole or other surface, and an adjustable bracket to be attached to the object to be mounted. The adjustable bracket is then positioned on the stationary bracket to mount the object on the surface or pole.
[0007] The invention provides the means to mount a product on a pole, pipe, column, or the like, and allow the product to be easily aimed in a particular direction, using separate pole adapters. It can also be used on walls without the pole adapters. It should be resistant to weather, wind, and vibration because it will typically be used outdoors. Stainless steel components are preferable. The bracket assembly is suitable for loudspeakers, lighting, signage, displays, monitors, video cameras, etc.
[0008] The invention is specifically designed for one person to install a fairly heavy item. The installer never needs to support the weight of the object and handle attachment hardware simultaneously. Competitive solutions require additional parts, more installers, expensive manufacturing methods, multiple adapters, etc. This system uses a minimal amount of inexpensive but robust components, providing both economic and time based efficiency for the installer.
[0009] The bracket assembly consists of two major components: a stationary bracket and an adjustable bracket. The stationary bracket is attached to the mounting surface, such as a wall, pole, column, etc. The adjustable bracket is attached to the product that requires directional positioning, and this can be done in a more convenient location than at the mount site which may be relatively inaccessible. Tapered springs guide the two brackets together during the initial mating. The adjustable bracket is then rotated into a locked position, and the two mount halves snap together temporarily (without tools or hardware) using integrated hooks and tabs. After this minimal effort, grip on the product can be released to allow for easy completion of the installation process. Two axel screws are inserted loosely through the adjustable bracket into locking threads in the stationary bracket. This forms the hinge, and the assembly is safely secured and ready for adjustment (although tightening of 4 mating screws and a safety tether is required for permanent use). To adjust the adjustable bracket, the tabs are released by compressing the angle adjustment wings on the adjustable bracket, and the product can then be rotated down. The spring causes these tabs to sequentially engage a series of holes so the user can evaluate the dispersion pattern or viewing angle achieved. When the desired position is selected, two screws permanently attach the brackets together and provide additional torque resistance. Finally the two axel screws are tightened to create 4 solid attachment points, and vertical adjustment from 0 to −70 degrees is achieved.
[0010] For use on poles and the like, the product includes a pole clamp assembly. Two adapter brackets with stepped teeth are attached to the stationary bracket. These adapters are designed for an ideal fit on 1-4″ cylinders, making contact with the cylinder at 4 points each. Larger diameters and irregular shapes can be accommodated, although contact points will likely be reduced to two per adapter. For convenience, a supplied nylon wire tie or other temporary tether is inserted through an opening in the stationary bracket. This can temporarily fasten the stationary bracket with adapters to the pole while clamp components are secured. The clamp is comprised of a length of link chain with a threaded J-hook or hooked rod at each end. These J-hooks pass through aligned slotted openings in the stationary bracket and pole adapters. Wing nuts on the J-hooks provide the means to easily tension the chain adequately without the need for tools, while preventing excessive clamping force. This combination of components fits a wide variety of pole shapes and sizes, produces excellent resistance to rotation, and reduces the likelihood of over tensioning. Additional tension on the clamp components only weakens the system, and wing nuts discourage over-tightening. After installation, the stationary mounting bracket is directly secured to the pole via the chain, hooks, and wing nuts, with the adapters trapped in between. This assembly can be tightened in any position around a pole, providing 360 degrees of horizontal adjustment. This clamp needs only to prevent rotation or slippage and, by nature, chain provides excellent resistance to these forces.
[0011] A speaker mounting bracket can be attached to the adjustable bracket, so that a loudspeaker can be mounted using the assembly according to the invention. The speaker mounting bracket is securely screwed to the adjustable bracket, and the speaker is mounted on the speaker mounting bracket. The assembly of the speaker, speaker mounting bracket and adjustable bracket can then be easily mounted on the stationary bracket to mount the speaker to a pole or other surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.
[0013] In the drawings, wherein similar reference characters denote similar elements throughout the several views:
[0014] FIG. 1 shows an embodiment of the stationary bracket for use in the assembly according to the invention;
[0015] FIG. 2 shows an embodiment of the adjustable bracket for use with the stationary bracket of FIG. 1 ;
[0016] FIG. 3 shows the initial placement of the adjustable bracket of FIG. 2 onto the stationary bracket of FIG. 1 ;
[0017] FIG. 3 a shows an enlarged detail III of FIG. 3 ;
[0018] FIG. 4 shows the preliminary mounting position of the adjustable bracket onto the stationary bracket;
[0019] FIG. 4 a shows enlarged detail IV of FIG. 4 ;
[0020] FIG. 5 shows the placement of the adjustable bracket into a final mounting position on the stationary bracket;
[0021] FIG. 5 a shows enlarged detail V of FIG. 5 ;
[0022] FIG. 6 shows the final mounting position of FIG. 5 , with the screws attached to secure the adjustable bracket to the stationary bracket;
[0023] FIG. 6 a shows enlarged detail VI of FIG. 6 ;
[0024] FIG. 7 shows the pole mounting brackets and how they are mounted to the stationary bracket of FIG. 1 ;
[0025] FIG. 8 shows a front view of the stationary bracket mounted on a pole;
[0026] FIG. 9 shows a side and rear view of the stationary bracket mounted on a pole;
[0027] FIG. 10 shows a speaker and a speaker mounting bracket for use with the adjustable bracket of FIG. 2 ; and
[0028] FIG. 11 shows the entire bracket assembly connected to a speaker and mounted on a pole.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Referring now in detail to the drawings and, in particular, FIG. 1 shows stationary bracket 10 for use in the assembly according to the invention. Stationary bracket 10 has a flat rear panel 11 and two side walls 12 , extending from panel 11 . Side walls 12 have an upper edge with hooks 13 , 14 , and a curved front edge with a series of apertures 15 . Side walls 12 also have a rear aperture 16 . Rear panel 11 has a plurality of mounting holes 17 , for mounting rear panel 11 on a flat surface, and also has slits 18 and supports brackets 19 (shown in FIGS. 3 and 4 ) for securing stationary bracket 10 to a pole, which will be described in detail below.
[0030] FIG. 2 shows one embodiment of an adjustable bracket 20 for use in the assembly according to the invention. Bracket 20 has a top surface 21 , and side walls 22 with flexible wings 25 below a slit 26 . Tabs 23 and 24 are disposed along the rear and front areas, respectively, of side walls 22 .
[0031] To connect adjustable bracket 20 to stationary bracket 10 , as shown in FIGS. 3 and 4 , tabs 24 on bracket 20 are placed into engagement with hooks 14 on bracket 10 (also shown in detail in FIG. 3 a ), and bracket 20 is rotated into position, so that tabs 23 on bracket 20 engage hooks 13 (shown in detail in FIG. 4 a ). This creates a temporary mounting position, where bracket 20 is supported by bracket 10 until a final adjustment position can be reached.
[0032] To reach a final adjustment position, where adjustable bracket 20 is placed at the desired angle with respect to stationary bracket 10 , two axel screws 29 are placed loosely through holes 16 and 28 on each side of brackets 10 , 20 to hold them together. Then, wings 25 are pressed inward until tabs 23 and 24 clear hooks 13 and 14 , respectively, as shown in FIGS. 5 and 5 a. Then, bracket 20 is rotated downward until a desired angle is reached. At this point, wings 25 can be released, which places tab 24 into one of the holes 15 along stationary bracket 10 . If the installer is satisfied with this position, then a further screw 30 is placed into one of holes 15 adjacent to tab 24 , which screw also extends though hole 31 on bracket 20 . Finally all of screws 29 , 30 are tightened to secure bracket 20 to bracket 10 in a final position.
[0033] Prior to connection of bracket 20 to bracket 10 , the object to be mounted is connected to bracket 20 , and bracket 10 is connected to the mounting surface, such as a wall or a pole. Then, bracket 20 is secured to bracket 10 , to mount the object to the mounting surface, in a simple manner. This way, even large, cumbersome objects can be securely mounted to a pole or a wall by a single installer.
[0034] As described above, bracket 10 can be mounted to a wall or other flat surface via holes 17 , in any conventional manner. For pole mounting, the arrangement shown in FIGS. 7-9 can be used. As shown in FIG. 7 , pole mounting bracket 19 , which has a vertical section 32 with slots 34 and a horizontal pole-mounting section 33 , can be attached to stationary bracket 10 via screws 36 through holes 17 on bracket 10 , and holes 35 on brackets 19 .
[0035] The mounting of bracket 10 to a pole 50 is shown in FIGS. 8 and 9 . Bracket 10 , with bracket 19 secured thereto, is placed against a pole 50 , so that horizontal section 33 of bracket 19 abuts pole 50 . Horizontal section 33 has a cutout to create ridged sections 55 , which can grip poles of various sizes, to reduce any slippage between pole 50 and brackets 19 . A strap 40 is then threaded through bracket 10 via slots 38 disposed on side walls 12 just in front of rear panel 11 . Strap 40 keeps bracket 10 in place until further securing measures are taken.
[0036] Subsequently, hooked securing rods 41 are fed through slots 18 and 34 in brackets 10 , 19 , respectively, and secured on threaded portions 43 with wing nuts 44 . Securing rods 41 each have a hook 42 on its opposite end, which extends along pole 50 . As shown in FIG. 9 , a chain is then hooked on hooks 42 to wrap around pole 50 to further secure bracket 10 to pole 50 . Finally, wing nuts 44 are tightened further to eliminate any slack in chain 52 , thus creating a tight connection between stationary bracket 10 and pole 50 .
[0037] FIG. 10 shows a possibility for mounting a speaker 60 to adjustable bracket 20 . First, speaker bracket 70 is attached to adjustable bracket 20 by screws 75 through holes 76 in speaker bracket 70 and holes 77 in adjustable bracket 20 . Knobs 63 are attached to speaker 60 on its top and bottom by extending threaded portion 64 of knob 63 through a washer 65 and then loosely screwing knob 63 into holes 62 on the top and bottom of speaker 60 . Thereafter, speaker bracket 70 is attached to speaker 60 by sliding speaker bracket 70 onto threaded portions 64 of knobs 63 via slits 72 until threaded portion 64 resides within aperture 71 . Then, knobs 63 are tightened to secure speaker 60 to speaker bracket 70 , as well as adjustable bracket 20 .
[0038] Once speaker 60 is connected to adjustable bracket 20 , adjustable bracket 20 can be mounted to stationary bracket 10 , which is already connected to a mounting surface or pole, in the manner discussed above with respect to FIGS. 1-9 , to form a pole-mounted speaker, as shown in FIG. 11 . In this Figure, adjustable bracket 20 has just been placed on stationary bracket 10 , prior to being moved into its final adjustment position and secured with screws, which is done in the manner described with respect to FIGS. 5-6 .
[0039] Accordingly, while only a single embodiment of the present invention has been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.
|
A mounting bracket assembly has a stationary bracket to be mounted on a pole or other surface, and an adjustable bracket to be attached to the object to be mounted. The adjustable bracket is then positioned on the stationary bracket to mount the object on the surface or pole. The adjustable bracket is first mounted on the stationary bracket in a preliminary mounting position using integrated hooks and latches, and then can be easily adjusted to a permanent mounting position and secured with screws.
| 5
|
BACKGROUND OF THE INVENTION
[0001] (1) Field of the Invention
[0002] This invention relates to a process for collecting seeds.
[0003] (2) Description of the Related Art
[0004] Some seeds of plants such as a cattail, reed, cogon, redtop, dandelion and cotton have fluffy fibers that help the seed be blown away by wind or be widely scattered by sticking to an animal body.
[0005] Regarding cotton among these plants, a cotton gin has been used for spinning cotton. On the other hand, a fluffy fiber of seed of the plants such as a cattail, reed, cogon and redtop does not have a length long enough to be spun by a cotton gin and to begin with, these plants have rarely been regarded as a cultivated plant.
[0006] Recently, cultivation of these plants besides cotton such as a cattail, reed, cogon and redtop, a seed of which has fluffy fibers, has been examined from viewpoints of conservation and improvement with respect to soil and environment.
[0007] Upon cultivation of these plants, the fluffy fibers of the seeds are in a tangle with each other among the seeds, resulting in a difficulty in separating grain from grain of the seed and obstruction for sowing work thereof.
[0008] Furthermore, these plants, a seed of which has the fluffy fibers, are so-called a wild plant and a germination rate of these plants is much lower than that of an ordinary cultivated plant. Therefore, a treatment for promoting the germination is needed, but then, the fluffy fibers of the seed have been obstructive for such treatment.
[0009] For the above reasons, a process for removing the fluffy fibers from the seeds and collecting only the seeds is required, however, such a process requires a very painstaking work, forcing workers to do a troublesome and inefficient work by hand.
SUMMARY OF THE INVENTION
[0010] It is therefore an objective of the present invention to solve the above problems and to provide a process for collecting seeds efficiently and simply at a low cost from a lump consisting of a plurality of seeds having fluffy fibers.
[0011] In order to attain the above objective, the present invention is to provide a process for collecting seeds from a lump consisting of a plurality of seeds having fluffy fibers, comprising the steps of: disentangling said lump; and burning the fluffy fibers after the disentanglement of said lump.
[0012] The seed having fluffy fibers is a seed of any one among a cattail, reed, cogon and redtop.
[0013] The disentanglement of said lump is carried out to such an extent that the step of burning the fluffy fibers is finished in a short period of time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic appearance of a seed of a cattail (a seed having fluffy fibers);
[0015] FIG. 2 is a schematic appearance of a seed of a cogon (a seed having fluffy fibers on the surface); and
[0016] FIG. 3 is a schematic appearance of a seed of a reed (a seed having fluffy fibers).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The process for collecting seeds according to the present invention is applicable to collect seeds of any plant besides plants such as a cattail, reed, cogon and redtop provided that the seed has fluffy fibers like a seed of cotton.
[0018] FIG. 1 is a schematic appearance of a seed of a cattail. Like a seed of a dandelion, the seed of a cattail has parachute-shaped fluffy fibers, in which a trunk-shaped fiber comes out from a body of the seed and forks into many fine fibers at the end of the trunk-shaped fiber.
[0019] FIG. 2 is a schematic appearance of a seed of a cogon having fluffy fibers, in which many fibers directly grow from both sides of a body of the seed.
[0020] FIG. 3 is a schematic appearance of a seed of a reed having fluffy fibers, in which many fibers radially grow from the end of a body of the seed.
[0021] In FIGS. 1 to 3 , a 1-centimeter scale graduated in millimeters is shown together with the schematic appearance of the seed.
[0022] According to the present invention, a lump consisting of a plurality of seeds having fluffy fibers is disentangled and then, the fluffy fibers are burned to collect the seeds.
[0023] The disentanglement of the lump of the seeds, in which the fluffy fibers are tangled with each other among the seeds, enables that air is supplied to the fluffy fibers sufficiently enough to burn the fluffy fibers in a short period of time upon the burning and that a distance between the burning fluffy fibers and the seed body is enlarged so as to minimize an influence of generated heat and flame upon each seed body. Consequently, the disentanglement of the lump of the seeds is preferably carried out to such an extent that the next step of burning the fluffy fibers is finished in a short period of time
[0024] To the contrary, when the fluffy fibers of the lump of the seeds, in which the fluffy fibers are tangled with each other among the seed, are burned without being disentangled prior to the burning, the generated heat and flame upon the burning cause damage to each seed body, resulting in severe deterioration in the germination rate of a plant.
[0025] The disentanglement of the lump of the seeds, in which the fluffy fibers are tangled with each other among the seeds, can be carried out in such a manner that the lump is torn off by hand or a tool such as a pair of tweezers and a carding machine provided that the seeds themselves are not damaged by using the carding machine.
[0026] Then, the fluffy fibers must be burned. To the contrary, when the fluffy fibers are removed by using chemicals such as a sulfuric acid, the seeds themselves are damaged, thereby causing severe deterioration in the germination rate of a plant.
EXAMPLES
[0000] Examination on Germination Rate
[0027] In the following, examples of the process for collecting seeds according to the present invention are explained.
[0028] A lump consisting of a plurality of cattail seeds (about 100 cattail seeds) of about 10 mm in diameter having fluffy fibers tangled with each other among the seeds was disentangled by hand and then, set fire by a cigarette lighter to the fluffy fibers to burn the fluffy fibers off, whereby seeds (A) according to the present invention are collected. The same lump of cattail seeds was directly set fire to the fluffy fibers to burn the fluffy fibers off without being disentangled prior to the burning, whereby seeds (B) are collected. The other same lump of cattail seeds was subjected to a seed-collection work by hand using a pair of tweezers, whereby seeds (C) are collected.
[0029] The process for collecting seeds (A) was very simple and the burning of the fluffy fibers finished promptly, and each seed body was flicked away before being caught by flames.
[0030] On the other hand, the process for collecting seeds (B) was also very easy but the burning was slow and lasted for a relatively long period of time with smoking. An observation of each body of the seed (B) revealed that some seeds (B) were carbonized. The collection work of the seeds (C) was very troublesome and required a long period of time.
[0031] One hundred grains of each kind of seeds were put (sown) on a petri dish of 120 mm in diameter, on which two filter papers were put one on top of the other, then 8 mL of water was added into the petri dish and then, the petri dish was capped. Four additional such petri dishes were prepared for each seed, then the petri dishes were put into a temperature controlled bath of 20 and then, a germination rate of each seed was investigated.
[0032] The results are shown in Table 1. In Table 1, measured germination rates of each seed with respect to number of days after the sowing are shown and numerical values in percent are rounded off to zero decimal place.
TABLE 1 5 th 10 th 15 th 20 th 25 th 30 th Seed day day day day day day Example A 4% 12% 33% 56% 52% 53% Comparative B 1% 4% 5% 5% 6% 7% Example 1 Comparative C 2% 10% 28% 44% 53% 55% Example 2
[0033] Table 1 reveals that the germination rate of the seed (A) according to the present invention is comparable to that of the seed (C), which is collected by hand, and that the disentanglement of the lump of the seeds prevents any damage from occurring to the seeds even if the fluffy fibers of the seeds are burned off.
[0000] Examination on Application to Gel-Coated Seed
[0034] Since a gel coating of seed enables a high germination rate of the seed and secures cultivation of a plant, the gel coating of seed has been applied to various kinds of seed.
[0035] A 20 g-lump of cattail seeds was disentangled by hand and then, set fire by a cigarette lighter to the fluffy fibers to burn the fluffy fibers off, whereby seeds (A) according to the present invention are collected. On the other hand, the other same 20 g-lump of cattail seeds (B) as it is without being disentangled was prepared.
[0036] The cattail seeds (A) and seeds (B) were thrown into respective 3 liters of 3-wt %-sodium alginate aqueous solution, then stirred so as to disperse the seeds. Then, the solution in which the seeds float was collected with a pipette and dropped into a 1-wt %-calcium chloride aqueous solutinon for gelation and then, taken out from the calcium chloride aqueous solutinon and washed with tap water.
[0037] A number of seeds enclosed in thus formed gel capsule were counted with respect to one hundred capsules of each kind. The results are shown in Table 2. In Table 2, a number of gel capsules is shown with respect to a number of seeds enclosed in a gel capsule.
TABLE 2 Number of enclosed seeds Seed (A) Seed (B) 0 8 37 1 43 0 2 40 0 3 9 0 4 or more 0 63
[0038] Table 2 reveals that a majority of capsules include one or two seed for the seeds (A) according to the present invention and that the number of gel capsules is not uniform with respect to the number of seed enclosed in a gel capsule for the seeds (B) according to a conventional process, therefore, no satisfactory gel-coated seed was produced according to the conventional process.
[0000] Basic Examination on Chemical Treatment of Seeds
[0039] A dipping of plant seeds into a chemical solution has been often tried in order to improve a germination rate of the seed and to prevent a damage of the seed due to disease.
[0040] However, when the above dipping method is applied to a seed having fluffy fibers, a contact between the seed and the chemicals is often inhibited due to a nature of the fluffy fibers or oils and fats adhering on the fluffy fibers.
[0041] As a basic examination on chemical treatment of the seeds, a 20 g-lump of cattail seeds was disentangled by hand and then, set fire by a cigarette lighter to the fluffy fibers to burn the fluffy fibers off, whereby seeds (A) according to the present invention are collected. On the other hand, the other same 20 g-lump of cattail seeds (B) as it is without being disentangled was prepared. The cattail seeds (A) and seeds (B) were dipped into respective 3 liters of water for four hours, then a water absorption of the seed was measured as follows: water adhering on the surface of the seed dipped into the water was well removed by using a filter paper; and a water content of the seed was measured by an infrared moisture meter. As a result, the water content of the seed (A) was 93.1 wt %, while that of the seed (B) was 42.7 wt %. The result suggests that a sufficient effect of the dipping into chemicals can not be attained unless the fluffy fibers of the seed having the fluffy fibers are removed and therefore that the aforementioned effect of the dipping into chemicals can be well attained with respect to the seed (A) of which fluffy fibers are removed by the process according to the present invention.
[0042] The aforementioned preferred embodiments are described to aid in understanding the present invention and variations may be made by one skilled in the art without departing from the spirit and scope of the present invention.
[0043] The process for collecting seeds according to the present invention is a very simple, efficient and excellent process, by which the seeds can be collected without being caused any substantial damage. Furthermore, a process to form a gel-coated seed can be easily carried out and a treatment of the seeds by various chemicals also can be easily carried out with respect to the seeds collected by the process according to the present invention.
|
A process for collecting seeds efficiently and simply at a low cost from a lump consisting of a plurality of seeds having fluffy fibers is provided. The process for collecting seeds includes the steps of disentangling the lump consisting of a plurality of seeds and burning the fluffy fibers after the disentanglement of the lump.
| 0
|
[0001] This application is based on and claims the benefit of priority from Japanese Patent Application No. 2007-002710, filed on 10 Jan. 2007, the content of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a gaming machine which provides an award corresponding to the number of played games within a predetermined time limit.
[0004] 2. Related Art
[0005] Conventionally, in regards slot machines, which are a type of gaming machine, a game is generally started by inserting a game medium such as coins into the gaming machine. Then, the slot machine displays an image of a symbol line which is rotated in a predetermined area of the gaming machine. After a predetermined amount of time elapses, the slot machine displays an image of the symbol line which is stopped. Finally, the slot machine provides an award to a player based on the combination of the stationary symbols. Whether a combination for which an award is provided has been formed or not is generally determined based on whether or not a predetermined number of the same type of symbols (for example, “Cherry”, “7”, etc.) is arranged along a predetermined active pay line. Furthermore, these slot machines have a game mode which can multiply payback to players. U.S. Pat. No. 7,052,392 discloses a technique that allows a player to improve the odds of winning in a bonus game associated with a result of a basic game.
SUMMARY OF THE INVENTION
[0006] Although U.S. Pat. No. 7,052,392 discloses a technique that allows a player to improve the odds of winning in a bonus game associated with a result of a basic game, the entertainment properties of the technique thus disclosed has become ordinary of recent, and thus players have lost interest.
[0007] The present invention has an object of providing a gaming machine which can further improve entertainment properties.
[0008] In an aspect of the present invention, a gaming machine is provided, which includes a memory, an input device and a controller. The memory stores a number of played games and a predetermined time limit applied to the games. The input device accepts an operation to start a game. The controller is configured with logic to: (a) start the game when the input device has accepted the operation to start the game; (b) start counting up time at predetermined regular intervals to the time limit when a result of the game satisfies a predetermined condition; (c) increase the number of played games each time a game is started; and (d) when the number of played games is equal to or greater than a predetermined threshold at expiration of the time limit, pay a player in accordance with a predetermined award.
[0009] The gaming machine described above allows the player to be paid in accordance with the predetermined award when the player can play the games the predetermined number of times within the time limit.
[0010] Since the player can advantageously increase the number of games in a lost game that does not need time to pay out, the gaming machine gives a new dimension to the game.
[0011] In another aspect of the present invention, a gaming machine is provided, which includes a display device, a memory, an input device and a controller. The display device displays an image related to a game. The memory stores a number of played games and a predetermined time limit applied to the games. The input device accepts an operation to start a game. The controller is configured with logic to: (a) start the game when the input device has accepted the operation to start the game; (b) start counting up time at predetermined regular intervals to the time limit when a result of the game satisfies a predetermined condition; (c) increase the number of played games each time a game is started; (d) cause the display device to display an image of the counted time; and (e) when the number of played games is equal to or greater than a predetermined threshold at expiration of the time limit, pay a player in accordance with a predetermined award.
[0012] The gaming machine described above allows the player to visually comprehend the counted time, providing more fun to the player in playing the game.
[0013] In still another aspect of the present invention, a gaming machine is provided, which includes a display device, a memory, an input device and a controller. The display device displays an image related to a game. The memory stores a number of played games and a predetermined time limit applied to the games. The input device accepts an operation to start a game. The controller is configured with logic to: (a) start the game when the input device has accepted the operation to start the game; (b) start counting up time at predetermined regular intervals to the time limit when a result of the game satisfies a predetermined condition; (c) increase the number of played games each time a game is started; (d) cause the display device to display an image of the counted time and the number of played games; and (e) when the number of played games is equal to or greater than a predetermined threshold at expiration of the time limit, pay a player in accordance with a predetermined award.
[0014] The gaming machine described above allows the player to visually comprehend the counted time and the number of played games, providing more fun to the player in playing the game.
[0015] In yet another aspect of the present invention, a gaming machine is provided, which includes a memory, an input device and a controller. The memory stores a number of played games and a predetermined time limit applied to the games. The input device accepts an operation to start a game. The controller is configured with logic to: (a) start the game when the input device has accepted the operation to start the game; (b) start counting up time at predetermined regular intervals to the time limit when a result of the game satisfies a predetermined condition; (c) increase the number of played games each time a game is started; and (d) when the number of played games is equal to or greater than a predetermined threshold at expiration of the time limit, pay a player in accordance with the number of played games.
[0016] The gaming machine allows the player to advantageously increase the number of games in a lost game that does not need time to pay out. Since the player can obtain the award in accordance with the number of played games, the player feel more excited in playing the game.
[0017] In a further aspect of the present invention, a gaming machine is provided, which includes a display device, a memory, an input device and a controller. The display device displays an image related to a game. The memory stores a number of played games and a predetermined time limit applied to the games. The input device accepts an operation to start a game. The controller is configured with logic to: (a) start the game when the input device has accepted the operation to start the game; (b) start counting up time at predetermined regular intervals to the time limit when a result of the game satisfies a predetermined condition; (c) increase the number of played games each time a game is started; (d) cause the display device to display an image of the counted time; and (e) when the number of played games is equal to or greater than a predetermined threshold at expiration of the time limit, pay a player in accordance with the number of played games.
[0018] In a still further aspect of the present invention, a gaming machine is provided, which includes a display device, a memory, an input device and a controller. The display device displays an image related to a game. The memory stores a number of played games and a predetermined time limit applied to the games. The input device accepts an operation to start a game. The controller is configured with logic to: (a) start the game when the input device has accepted the operation to start the game; (b) start counting up time at predetermined regular intervals to the time limit when a result of the game satisfies a predetermined condition; (c) increase the number of played games each time a game is started; (d) cause the display device to display an image of the counted time and the number of played games; and (e) when the number of played games is equal to or greater than a predetermined threshold at expiration of the time limit, pay a player in accordance with the number of played games.
[0019] According to the present invention, a player can enjoy further entertainment properties.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a flowchart showing the flow of a game which is executed in a slot machine according to the preferred embodiment of the present invention;
[0021] FIG. 2 is an external perspective view showing the slot machine according to the preferred embodiment of the present invention;
[0022] FIG. 3 is an enlarged front view showing an enlarged view of a display region of the slot machine according to the preferred embodiment of the present invention;
[0023] FIG. 4 is a block diagram showing a controller of the slot machine according to the preferred embodiment of the present invention;
[0024] FIG. 5 is a block diagram showing a display/input controller of the slot machine according to the preferred embodiment of the present invention;
[0025] FIG. 6 is a diagram showing a symbol line represented on each video reel according to a preferred embodiment of the present invention;
[0026] FIG. 7 is a diagram showing a symbol arrangement table according to the preferred embodiment of the present invention;
[0027] FIG. 8 is a flowchart showing a main flow for a game program executed by the slot machine according to the preferred embodiment of the present invention;
[0028] FIG. 9 is a flowchart showing a flow for processing a basic game executed by the slot machine according to the preferred embodiment of the present invention;
[0029] FIG. 10 is a flowchart showing a flow for processing a basic game executed by the slot machine according to the preferred embodiment of the present invention;
[0030] FIG. 11 is a continued flowchart from FIG. 10 .
[0031] FIG. 12 is a diagram showing a random number table for a basic game according to the preferred embodiment of the present invention;
[0032] FIG. 13 is a diagram showing a payout table for a basic game according to the preferred embodiment of the present invention;
[0033] FIG. 14 is a diagram showing a payout table for a sub game according to the preferred embodiment of the present invention; and
[0034] FIGS. 15 and 16 are examples of display images according to the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The embodiments of the present invention are hereinafter described in detail with reference to the attached drawings.
[0036] The slot machine 13 according to the present invention is provided with RAM 110 storing the number of played games and a predetermined time limit in regards to the game, and a touch panel 32 accepting an input by a start operation in the game. A CPU 106 starts the game in response to the acceptance of the input by the start operation in the game by way of a start switch 25 . When a predetermined condition is generated, the CPU 106 starts processing for incrementing by a certain number the number of the played games every time the game is started. Upon a predetermined time limit elapsing, in a case in which the number of the played games is more than the predetermined times of the games thus played, the CPU 106 provides an award according to a predetermined award.
[0037] Specifically, as shown in FIG. 1 , the CPU 106 CPU 106 starts the game in response to the acceptance of the input by the start operation in the game by way of a start switch 25 (Step S 100 ). When a predetermined condition is generated, the CPU 106 starts processing for counting a predetermined time limit at a predetermined time interval (Step S 200 ). Then, the CPU 106 starts processing for incrementing by a certain number the number of the played games every time the game is started (Step S 300 ). Upon the predetermined time limit elapsing, in a case in which the number of the played games is more than the predetermined times of the games thus played, the CPU 106 provides an award according to a predetermined award (Step S 400 ).
[0038] FIG. 2 is a perspective diagram illustrating the slot machine 13 according to the embodiment of the present invention. The slot machine 13 includes a cabinet 20 and a main door 42 . The cabinet 20 has a structure in which the face facing the player is open. The cabinet 20 includes various kinds of components. Such components include: a controller 100 (see FIG. 4 ) for electrically controlling the slot machine 13 ; a hopper 44 for controlling insertion, retaining, and paying out of coins (game medium) (see FIG. 4 ), etc. The game medium is not restricted to coins. Furthermore, examples of such game media include medals, tokens, electronic money or electronic value information (credit) having the same value.
[0039] The main door 42 is a member that serves as a cover of the cabinet 20 , which protects the internal components stored in the cabinet 20 from being exposed to the outside. The main door 42 includes the liquid crystal display 30 at approximately the center thereof.
[0040] The liquid crystal display 30 is provided for displaying various kinds of images with respect to the game such as images for providing visual effects. Such an arrangement allows the player to advance the game while visually confirming various kinds of images displayed on the liquid crystal display 30 . The liquid crystal display 30 includes a transparent liquid crystal panel 34 . The transparent liquid crystal panel 34 has a function of switching a part of or the entire area of the liquid crystal panel 34 between a transparent mode and an opaque mode, and a function of displaying various kinds of images.
[0041] In a configuration in which the slot machine 13 includes video reels, five virtual reels are displayed on the liquid crystal display 30 . Note that the term “video reel” as used here represents a mechanism for displaying a reel on the liquid crystal display 30 in the form of an image. Multiple kinds of symbols necessary for the basic game include “BONUS”, “WILD”, “TREASURE BOX”, “GOLDEN MASK”, “HOLY CUP”, “COMPASS & MAP”, “SNAKE”, “A”, “K”, “Q”, “J”, and “10”. With such an arrangement, the liquid crystal display 30 displays these symbols with an image as if the reel were rotating.
[0042] The slot machine 13 includes an approximately horizontal operation unit 21 below the liquid crystal display 30 . Furthermore, a coin insertion opening 22 is provided on the right side of the operation unit 21 , which allows the player to insert coins. On the other hand, the components provided to the left side of the operation unit 21 include: a bet switch 23 which allows the player to determine which lines are to be set to active pay lines among nine lines L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7 , L 8 , and L 9 , for providing an award described later (which will simply be referred to as “active pay lines” hereafter), and which allows the player to select the number of coins as game media which are to be bet on the active pay lines; a spin repeat bet switch 24 which allows the player to play the game again without changing the number of coins bet on the active pay lines from that in the immediately prior game. Such an arrangement allows the player to set the number of coins bet on the active pay lines by performing a pressing operation on either the bet switch 23 or the spin repeat bet switch 24 .
[0043] With the operation unit 21 , a start switch 25 is provided on the left side of the bet switch 23 , which allows the player to input a start operation instruction for the basic game in increments of games. Upon performing a pressing operation on either the start switch 25 or the spin repeat bet switch 24 , which serves as a trigger to start the game, the five mechanical reels 3 A to 3 E start to rotate.
[0044] On the other hand, a cash out switch 26 is provided near the coin insertion opening 22 . Upon the player pressing the cash out switch 26 , the inserted coins are paid out from a coin payout opening 27 provided at a lower portion of the front face of the main door 42 . The coins thus paid out are retained in a coin tray 28 . Furthermore, the coin payout opening 27 is provided on the upper side of the coin tray 28 , with sound transmission openings 29 provided to both the left and right of the coin payout opening 27 . Here, the sound transmission openings 29 are provided for transmitting sound effects generated by a speaker 41 (see FIG. 4 ) stored within the cabinet 20 .
[0045] FIG. 3 is an enlarged view illustrating the display region of the slot machine 13 . The liquid crystal display 30 of the slot machine 13 includes a front panel 31 and the transparent liquid crystal panel 34 provided to the rear face of the front panel 31 . The front panel 31 comprises a transparent display screen 31 a and a design formation area 31 b where designs have been formed. Such an arrangement allows the player to visually confirm the image information displayed on the transparent liquid crystal panel 34 provided to the rear face of the front panel 31 through the display screen 31 a of the front face 31 . On the other hand, let us consider an arrangement in which the slot machine 13 comprises video reels. With such an arrangement, the transparent liquid crystal panel 34 in an opaque state may display the reels in the form of an image. Furthermore, an ordinary liquid crystal panel may be employed instead of the transparent liquid crystal panel 34 .
[0046] Furthermore, various kinds of display units, i.e., a payout display unit 48 , a credit amount display unit 49 , and a bet amount display unit 50 , are provided on the left side of the rear face the liquid crystal display 30 . Note that the design formation area 31 b of the front panel 31 is formed having a transparent portion that covers the top faces of these display units 48 through 50 , thereby allowing the player to visually confirm the contents displayed on the display units 48 through 50 .
[0047] The slot machine 13 has the nine lines L 1 through L 9 for providing awards as shown in FIG. 3 . Each of the lines L 1 through L 9 for providing awards is formed such that it extends so as to pass through one of the symbols for each of the mechanical reels 3 A to 3 E when the five video reels have stopped.
[0048] Upon pressing the bet switch 23 once, the line L 3 for providing a third award, the line L 5 for providing a fifth award, and the line L 7 for providing a seventh award, are set to be active pay lines, and one coin is input as a credit medal, for example.
[0049] Furthermore, upon pressing the bet switch 23 twice, the line L 1 for providing a first award, the line L 4 for providing a fourth award, and the line L 8 for providing an eighth award, are set to be active pay lines, in addition to the three lines, and two coins are input as credit medals, for example.
[0050] Furthermore, upon pressing the bet switch 23 three times, the line L 2 for providing a second award, the line L 6 for providing a sixth award, and the line L 9 for providing a ninth award, are set to be active pay lines, in addition to the six lines, and three coins are input as credit medals, for example.
[0051] The payout display unit 48 is a component for displaying the amount of the coins paid out when a combination of the symbols has been established along any one of the active lines for providing an award. The credit amount display unit 49 is a component for displaying the amount of the coins retained in the slot machine 13 in the form of a credit. The bet amount display unit 50 is a component for displaying the bet amount which is the number of coins bet on the active pay lines. Each of the display units 48 through 50 comprises a segment display device. Alternatively, each of the display units 48 through 50 may be displayed on the transparent liquid crystal panel 34 in the form of an image.
[0052] FIG. 4 is a block diagram illustrating an electric constitution of the controller 100 of the slot machine 13 having video reels. As shown in FIG. 4 , the controller 100 of the slot machine 13 is a micro computer, and includes an interface circuit group 102 , an input/output bus 104 , the CPU 106 , ROM 108 , RAM 110 , a communication interface circuit 111 , a random number generator 112 , a speaker driving circuit 122 , a hopper driving circuit 124 , a display unit driving circuit 128 , and a display/input controller 140 .
[0053] The interface circuits 102 are electrically connected with the input/output bus 104 , which carries out input and output of data signals and address signals for the CPU 106 .
[0054] The start switch 25 is electrically connected with the interface circuits 102 . In the interface circuits 102 , a start signal generated by the start switch 25 is transformed into a predetermined form of signal to be supplied to the input/output bus 104 .
[0055] Furthermore, the bet switch 23 , the spin repeat bet switch 24 , and the cash out switch 26 are connected to the interface circuit group 102 . In the interface circuits 102 , a switching signal generated by each of these switches 23 , 24 and 25 is transformed into a predetermined form of signal to be supplied to the input/output bus 104 .
[0056] A coin sensor 43 is also electrically connected with the interface circuits 102 . The coin sensor 43 detects coins inserted into the coin insertion slot 22 , and is disposed at an appropriate position relative to the coin insertion slot 22 . In the interface circuits 102 , a sensing signal generated by the coin sensor 43 is transformed into a predetermined form of signal to be supplied to the input/output bus 104 .
[0057] The ROM 108 and the RAM 110 are connected to the input/output bus 104 .
[0058] Upon reception of the basic game start operation instruction input through the start switch 25 , which serves as a trigger, the CPU 106 reads out a basic game program, and executes the basic game. The basic game program has been programmed so as to instruct the CPU 106 to perform the following operation. That is to say, according to the basic game program, the CPU 106 displays an image of the five video reels commencing to scroll the symbols on the five video reels on the liquid crystal display 30 via the display/input controller 140 . Then, the CPU 106 displays an image of the five video reels stopping such that the combination of the symbols on these five video reels is rearranged, whereupon a new combination of the symbols is made along the active pay lines. In a case that a specified combination of the stationary symbols for providing an award has been made along any one of the active pay lines, the CPU 106 pays out a predetermined amount of coins corresponding to the specified combination for providing the award.
[0059] The ROM 108 stores: a control program for central control of the slot machine 13 ; a program for executing a routine shown in FIG. 8 and FIG. 11 (which is referred to as the “routine execution program” hereafter); initial data for executing the control program; and various data tables used for determination processing. Note that the routine execution program includes the basic game program etc. The RAM 110 temporarily stores flags, variables, etc., used for the control program.
[0060] Furthermore, a communication interface circuit 111 is connected to the input/output bus 104 . The communication interface circuit 111 is a circuit for communicating with a server, etc., via various kinds of communication networks including a public telephone line network, LAN, etc.
[0061] Furthermore, the random number generator 112 for generating a random number is connected to the input/output bus 104 . The random number generator 112 generates a random number in a predetermined range, e.g., in a range of 0 and 65535 (the sixteenth power of two minus one). Alternatively, an arrangement may be made in which the CPU 106 generates a random number by computation.
[0062] Furthermore, the display unit driving circuit 128 for driving each of the display units 48 through 50 is connected to the input/output bus 104 . The CPU 106 controls the operation of each of the display units 48 through 50 via the display unit driving circuit 128 according to occurrence of a predetermined event.
[0063] The speaker drive circuit 122 for the speakers 41 is also electrically connected with the input/output bus 104 . The CPU 106 reads out the sound data stored in the ROM 108 , and transmits the sound data thus read to the speaker driving circuit 122 via the input/output bus 104 . In this way, the speakers 41 generate predetermined sound effects.
[0064] The hopper drive circuit 124 for driving the hopper 44 is also electrically connected with the input/output bus 104 . Upon reception of a cash out signal input from the cash out switch 26 , the CPU 106 transmits a driving signal to the hopper driving circuit 124 via the input/output bus 104 . Accordingly, the hopper 44 pays out coins such that the number of them is equivalent to the current number of coins remaining as credit, which is stored in a predetermined memory area of RAM 110 .
[0065] Furthermore, the display/input controller 140 is connected to the input/output controller 140 . The CPU 106 creates an image display command corresponding to the state and results of the game, and outputs the image display command thus created to the display/input controller 140 via the input/output bus 104 . Upon reception of the image display command input from the CPU 106 , the display/input controller 140 creates a driving signal for driving the liquid crystal display 30 according to the image display command thus input, and outputs the driving signal thus created to the liquid crystal display 30 . As a result, a predetermined image is displayed on the transparent liquid crystal panel 34 of the liquid crystal display 30 . The display/input controller 140 transmits the signal input through the touch panel 32 provided on the liquid crystal display 30 to the CPU 106 via the input/output bus 104 in the form of an input signal.
[0066] FIG. 5 is a block diagram illustrating the electric constitution of display/input controller 140 of the slot machine 13 . The display/input controller 140 of the slot machine 13 is a sub-microcomputer for performing image display processing and input control for the touch panel 32 . The display/input controller 140 comprises an interface circuit 142 , an input/output bus 144 , the CPU 146 , ROM 148 , RAM 150 , a VDP 152 , video RAM 154 , image data ROM 156 , a driving circuit 158 , and a touch panel control circuit 160 .
[0067] The interface circuit 142 is connected to the input/output bus 144 . The image display command output from the CPU 106 of the controller 100 is supplied to the input/output bus 144 via the interface circuit 142 . The input/output bus 144 performs input/output of data signals or address signals to/from the CPU 146 .
[0068] Furthermore, the ROM 148 and the RAM 150 are connected to the input/output bus 144 . The ROM 148 stores a display control program for generating a driving signal, which is to be supplied to the liquid crystal display 30 , according to an image display command received from the CPU 106 of the controller 100 . On the other hand, the RAM 150 stores flags and variables used in the display control program.
[0069] Furthermore, the VDP 152 is connected to the input/output bus 144 . The VDP 152 includes a so-called sprite circuit, a screen circuit, a palette circuit, etc, and can perform various kinds of processing for displaying images on the liquid crystal display 30 . With such an arrangement, the components connected to the VDP 152 include: the video RAM 154 for storing image data according to the image display command received from the CPU 106 of the controller 100 ; and the image data ROM 156 for storing various kinds of image data including the image data for visual effects etc. Furthermore, the driving circuit 158 for outputting a driving signal for driving the liquid crystal display 30 is connected to the VDP 152 .
[0070] The CPU 146 instructs the video RAM 154 to store the image data which is to be displayed on the liquid crystal display 30 according to the image display command received from the CPU 106 of the controller 100 by reading out the display control program stored in the ROM 148 and by executing the program thus read. Examples of the image display commands include various kinds of image display commands including the image display commands for visual effects etc.
[0071] The image data ROM 156 stores various kinds of image data including the image data for visual effects etc.
[0072] The touch panel control circuit 160 transmits the signals input via the touch panel 32 provided on the liquid crystal display 30 to the CPU 106 via the input/output bus 144 in the form of an input signal.
[0073] FIG. 6 shows symbol lines on which 21 symbols arranged on each video reel 3 A to 3 E are represented. The symbol line for the first video reel corresponds to the video reel 3 A. The symbol line for the second video reel corresponds to the video reel 3 B. The symbol line for the third video reel corresponds to the video reel 3 C. The symbol line for the fourth video reel corresponds to the video reel 3 D. The symbol line for the fifth video reel corresponds to the video reel 3 E.
[0074] Referring to FIG. 6 , a code number of “00” to “20” is assigned to for each symbol of video reels 3 A to 3 E. The code number is converted to be data in a data table so as to be stored in the ROM 108 ( FIG. 4 ).
[0075] On each video reel 3 A to 3 E, a symbol line is represented with symbols as follows: Bonus symbol (symbol 61 ) (hereafter, “Bonus”), Wild symbol (symbol 62 ) (hereafter, “Wild”), Treasure Chest symbol (symbol 63 ) (hereafter, “Treasure Chest”), Golden Mask symbol (symbol 64 ) (hereafter, “Golden Mask”), Holy Grail symbol (symbol 65 ) (hereafter, “Holy Grail”), Compass and Map symbol (symbol 66 ) (hereafter, “Compasses and Map”), Snake symbol (symbol 67 ) (hereafter, “Snake”), Ace symbol (symbol 68 ) (hereafter, “Ace”), King symbol (symbol 69 ) (hereafter, “King”), Queen symbol (symbol 70 ) (hereafter, “Queen”), Jack symbol (symbol 71 ) (hereafter, “Jack”), and 10 symbol (symbol 72 ) (hereafter, “10”). The symbol line of each video reel 3 A to 3 E displays an image moving to the direction of the arrow in FIG. 8 (moving below from the top) by displaying an image that the each video reel 3 A to 3 E is being moved in forward direction.
[0076] Here in the present embodiment, each combination of “Bonus”, “Wild”, “Snake”, “Treasure Chest”, “Golden Mask”, “Holy Grail”, “Compass and Map”, “Ace”, “King”, “Queen”, “Jack” and “10” is set as an award combination. A combination (combination data) is control information which relates credits awarded to a player (the amount of payout of coins) to a combination of an award combination, and which is used for stop control of each video reel 3 A through 3 E, change (shift) of a game state, awarding of coins, and the like.
[0077] FIG. 7 shows a symbol arrangement table. The symbol arrangement table relates the code number indicating the position of each symbol which constitutes the symbol lines to each symbol of the respective video reels 3 A to 3 E, and then, registers thereof. In addition, the first video reel through the fifth video reel corresponds to the video reels 3 A to 3 E, respectively. In other words, the symbol arrangement table includes symbol information corresponding to the symbol position (the code number) of video reels 3 A to 3 E.
[0078] FIG. 8 is a flow chart illustrating a flow of the processing operation in the game machine 13 executed by the controller 100 of the game machine 13 . The processing operation is called from a main program for the slot machine 13 at a predetermined timing, and then executed.
[0079] A description is provided below regarding a case in which the slot machine 13 has been activated beforehand. Furthermore, let us say that the variables used by the CPU 106 included in the controller 100 have been initialized to predetermined values, thereby operating the slot machine 13 in a normal state.
[0080] As shown in FIG. 6 , the CPU 106 included in the controller 100 firstly determines whether or not any coins inserted by the player are remaining in a main flow of the game program executed in the gaming machine 13 (Step S 1 ). More specifically, the CPU 106 reads an amount of credits C stored in RAM 110 and executes processes according to the amount of credits C thus read. When the amount of credits C equals “0” (NO in Step S 1 ), the CPU 106 terminates the routine without executing any process, because it cannot start a game. When the amount of credits C is not less than “1” (YES in Step S 1 ), the CPU 106 determines that coins remain as credit, and moves the process to Step S 2 .
[0081] The term “coin” refers to a game credit in the gaming machine. The credit may be currency circulated in the country where the present invention can be carried out. For example, the credit may also be medals that are uniquely used in the game hall where the present invention can be carried out and that are available to players by exchanging with currency in that country. Furthermore, the credits may be electromagnetic or electric information which can be stored in a storage medium such as a magnetic medium, an optical medium, or the like. In the case of electric information, the coin is stored in the storage medium as an award with values corresponding to the amount of the coins. In addition, “the coin” may be given to players by way of printed information such as a bar code, QR code, and the like, as well as being stored in the storage medium. In the present embodiment described below, although the coins as medals are paid out, it is selectable according to the way of payout employed in the gaming machine.
[0082] Upon advancing to Step S 2 , the CPU 106 sets a game condition, and moves the processing to Step S 3 . Specifically, the CPU 106 determines the number of coins bet in a basic game described later based on the number of the coins inserted by a player. Then, the CPU 106 receives an operational signal generated by a pressing operation of a bet switch 43 . Based on the number of times the operational signal has been received, the CPU stores the bet amount in a predetermined memory area of the RAM 110 . The CPU 106 reads the amount of credits C written in a predetermined area in the RAM 110 . The CPU 106 subtracts a total bet amount including the abovementioned bet amount from the amount of credits C thus read. Then, the CPU 106 stores the subtracted value in a predetermined memory area in the RAM 110 .
[0083] In Step S 3 , the CPU 106 determines whether or not a sub game flag is activated (described hereafter). More specifically, the CPU 106 refers to the flag which is stored in a predetermined area of the RAM 110 , and determines whether it is activated or not. If it is activated (YES determination in the Step S 3 processing), the CPU 106 moves the processing to Step S 5 . If it is not activated (NO determination in Step S 3 processing), the CPU 106 moves the processing to Step S 4 .
[0084] In the following Step S 4 , the CPU 106 performs basic game processing. When the basic game processing is terminated, the CPU 106 advances the process to Step S 6 .
[0085] Upon moving to Step S 5 , the CPU 106 performs processing of a basic game with the sub game described later. When the basic game with the sub game is finished, the CPU 106 terminates the routine.
[0086] In Step S 6 , the CPU 106 determines whether or not the symbol combination matches Holy Grail. Specifically, the CPU 106 determines whether the determined symbol combination is Holy Grail or not in the basic game. If it is Holy Grail (in the case of determination of “YES” in the processing in Step S 6 ), the CPU 106 advances the processing to Step S 7 . On the other hand, if it is not Holy Grail (in the case of determination of “NO” in the processing in Step S 6 ), the CPU 106 terminates the routine.
[0087] In Step S 7 , the CPU 106 activates the sub game flag. More specifically, the CPU 106 activates the sub game flag which is stored in a predetermined area of the RAM 110 . Upon finishing the processing in Step S 7 , the CPU 106 terminates the routine.
[0088] A description is made regarding a basic game processing with reference to FIG. 8 .
[0089] In the following Step S 11 , the CPU 106 determines whether or not the start switch 25 is activated. Based on the determination, the CPU 106 stands by as is until the player operates the start switch 25 . Upon the player operating the start switch 25 , and accordingly, upon receipt of an operation signal via the start switch 25 (in a case of “YES” in the determination processing denoted by Step S 11 ), the CPU 106 determines that the start switch 25 has been operated, and accordingly, the CPU 106 moves the processing to Step S 12 .
[0090] Upon moving to Step S 12 , the CPU 106 performs processing for determining a symbol combination. A specific description is provided below regarding the combination determination processing.
[0091] In the combination determination processing, first, the CPU 106 determines the combinations of the stationary symbols along the active pay lines. Specifically, the CPU 106 issues a command for the random number generator 112 to generate a random number, thereby extracting a random number in a predetermined range (in a range of “0” to “65535” in the present embodiment) generated by the random number generator 112 . The CPU 106 stores the random number thus extracted in a predetermined memory area of the RAM 110 . In this embodiment, the random number generator 112 displaced outside the CPU 106 generates random numbers. However, the present invention is not restricted to this setup. It may be alternatively possible that the CPU 106 generates random numbers without the random number generator 112 . The CPU 106 reads a random number table for a basic game (see FIG. 12 ), and a payout table for a basic game (see FIG. 13 ), each of which is stored in the ROM 108 . Then, the CPU 106 stores the random number table for a basic game and the payout table for a basic game thus read in a predetermined memory area of the RAM 110 . It should be noted that the CPU 106 controls display of the stationary symbols for each reel based upon the random number table for a basic game. Furthermore, the CPU 106 reads the random number table for a basic game and the payout table for a basic game stored in the predetermined area of the RAM 110 . Then, the CPU 106 determines the combination of the stationary symbols with respect to the active pay lines with reference to the random number table for a basic game, using the random number stored in the predetermined memory region of the RAM 110 as a parameter. Upon determination of specified combinations for providing an award, the CPU 106 stores the specified combination data for providing an award thus determined in a predetermined memory area of the RAM 110 . Then, the CPU 106 reads out the random number and the specified combination data for providing an award stored in the predetermined memory area of the RAM 110 , and determines the combination of the stationary symbols to be displayed based upon the random number and the specified combination data for providing an award thus read. In this stage, a symbol arrangement table (see FIG. 7 ) stored in the ROM 108 is read by the CPU 106 . The symbol arrangement table thus read is stored in a predetermined memory area of the RAM 110 , and used as reference data. The CPU 106 stores the data for the stationary symbols thus determined in a predetermined memory area of the RAM 110 . Alternatively, an arrangement may be made in which the stationary symbols are determined for each reel using the random number table for a basic game.
[0092] Upon determination of the combination of the stationary symbols with respect to the active pay lines, the CPU 106 determines whether or not the combination of the stationary symbols with respect to the active pay lines matches any one of the specified combinations for providing an award. In a case that the stationary combination of the symbols with respect to the active pay lines matches any one of the specified combinations for providing an award, the CPU 106 activates a flag, which indicates that the player has won the award that corresponds to the kind of specified combination for providing an award, in order to provide the award that accords with the specified combination of symbols with respect to the active pay lines for providing the award. The activated flag, which indicates the player has won an award, is stored in a predetermined area of the RAM 110 according to the instruction from the CPU 106 . On the other hand, in a case that the combination of the stationary symbols with respect to the active pay lines matches any one of the other combinations, i.e., the losing combinations, the CPU 106 does not activate the flag which indicates that the player has won an award. Subsequently, the CPU 106 moves the process to Step S 6 .
[0093] Here, a random number table for basic games shown in FIG. 12 is explained. In the random number table for a basic game, a range of random numbers and the probability of winning are registered in association with each of the specified winning combinations. In processing for determining a symbol combination, for example, in a case where a random number lying in a range of “0” to “299” is extracted from a range of numbers between “0” to “165535”, the internal component of the slot machine 13 determines to generate a bonus combination as the final results of the basic game. In other words, the probability is “300/65536” that the combination of the stationary symbols matches any one of the bonus combinations. On the other hand, in a case where a random number lying in a range of “10000” to “165535” is extracted from a range of numbers “0” to “65535”, the internal component of the slot machine 13 determines to generate other combinations, i.e. losing combinations, as the final results of the basic game. In other words, the probability is “55536/65536” that the combination of the stationary symbols matches any one of the losing combinations.
[0094] FIG. 13 shows a payout table for a basic game. In the payout table for a basic game, the coin amount to be paid out is registered in association with each specified combination for providing an award for each credit amount bet on one game. Therefore, let us consider a stage in which a determination is made whether the combination thus generated matches any one of the specified combinations for providing an award. In this stage, let us consider a case in which the combination thus generated matches the combination “Wild”. In this case, in a case where the credit amount bet is “1”, 50 coins are paid out. In a case where the credit amount bet is “2”, 100 coins are paid out. In a case where the credit amount bet is “3”, 150 coins are paid out.
[0095] Referring to Step S 9 again, the CPU 106 instructs the video reels 3 A through 3 E to start to rotate. Specifically, the CPU 106 displays an image which shows rotating the video reels 3 A to 3 E, in sequence or Simultaneously, based upon the symbol arrangement table stored in the RAM 110 .
[0096] Upon beginning to display a video image of the video reels 3 A through 3 E starting to rotate, the CPU 106 waits for a predetermined period of time to elapse (Step S 14 ). After the predetermined period of time has elapsed (in a case of “YES” in the determination processing in Step S 14 ), the CPU 106 instructs the video reels 3 A through 3 E to automatically stop rotating (Step S 15 ). Specifically, the CPU 106 displays an image of the video reels 3 A through 3 E stopping to rotate in a predetermined order or at the same time such that the stationary symbols, which correspond to a specified winning combination as determined in the Step S 12 , is displayed in a display region that can be observed by the player. The CPU 106 then moves the processing to Step S 16 .
[0097] In the following Step S 16 , the CPU 106 determines whether a predetermined symbol combination has been formed based upon the results of the combination determination processing performed in Step S 12 . Specifically, the CPU 106 makes this determination based upon the state of the flag that indicates whether or not the player has won an award with respect to the active pay lines stored in the predetermined memory area of the RAM 110 . In a case where the flag, which indicates that the player has won an award, has not been activated, i.e. in a case where the symbol combination matches a combination of “Others”, which is a combination other than the specified combinations for providing an award (in a case of NO in the determination processing in Step S 10 ), the CPU 106 determines that the specified combination for providing an award has not been formed, and ends this routine. On the other hand, in a case where the flag, which indicates that the player has won an award, has been activated, i.e. in a case where the symbol combination matches any one of the combinations other than the combination of “Others” (in a case of YES in the determination processing in Step S 10 ), the flow proceeds to Step 11 according to the instruction from the CPU 106 .
[0098] In the following Step S 17 , the CPU 106 determines whether the symbol combination thus formed based upon the combination determination processing performed in Step S 12 is a bonus combination. Specifically, the CPU 106 makes this determination based upon the state of the flag that indicates whether or not the player has won an award with respect to the active pay lines stored in the predetermined memory area of the RAM 110 . In a case where the flag, which indicates that the player has won an award, has been activated, and the specified combination for providing an award is a “bonus” combination, the flow proceeds to Step 18 according to the instruction from the CPU 106 . If not, the flow proceeds to Step 19 .
[0099] In the following Step S 18 , the CPU 106 performs bonus game processing. Upon finishing the processing in Step S 11 , the CPU 106 terminates the routine.
[0100] In a case where the flow has proceeded to Step S 19 , the CPU 106 pays out an amount of coins corresponding to the specified combination for providing an award. Specifically, the CPU 106 calculates the amount of coins to be paid out for the specified combination for providing an award, with reference to the payout table for a basic game ( FIG. 17 ). The CPU 106 reads out the credit amount stored in the predetermined memory area of the RAM 110 . Then, the CPU 106 calculates the sum total amount of coins to be paid out thus calculated and the credit amount thus read, and stores the sum thus calculated in a predetermined memory area of the RAM 110 . Furthermore, the CPU 106 displays the sum thus stored on the credit amount display unit 49 . Subsequently, the CPU 106 terminates the routine.
[0101] A description is provided regarding a basic game with sub game processing with reference to FIG. 10 and FIG. 11 .
[0102] Firstly, in Step S 21 , the CPU 106 included in the controller 100 sets S as a time limit of the sub game to 60 seconds. Then, the CPU 106 performs counting at one second intervals, and moves the processing to Step S 22 . Specifically, the CPU 106 stores the value “60” as the time limit in a predetermined memory area in the RAM 110 , and performs decrementing the value at one second intervals.
[0103] In Step S 22 , the CPU 106 initializes the number of sub games played to zero, and moves the processing to Step S 23 . More specifically, the CPU 106 stores the value of the number of games in a predetermined area of the RAM 110 and sets the value to zero.
[0104] In Step S 23 , the CPU 106 decides whether the start switch is activated or not. If it is activated, the CPU 106 moves the processing to Step S 24 . If it is not activated, the CPU 106 moves the processing to Step S 23 . Specifically, this processing is the same as that in Step S 11 described above with reference to FIG. 9 .
[0105] Referring to FIG. 10 again, in Step S 24 , the CPU 106 increments by 1 the number of sub games played and the processing proceeds to Step S 25 . Specifically, the CPU 106 increments by 1 the number of sub games played stored in a predetermined memory area in the RAM 110 .
[0106] In Step S 25 , the CPU 106 displays a numeral image in regards to processing for a counting time limit in S 21 and the number of sub games played. Then, the CPU 106 moves the processing to Step S 26 . Specifically, the CPU 106 displays, on the liquid crystal display 30 via the display/input controller 140 , a value of the time limit of the sub game during counting and a value of the number of sub games played, which are stored in a predetermined memory area in the RAM 110 .
[0107] In Step S 26 , the CPU 106 performs processing for determining a symbol combination and then moves the processing to Step S 27 . Specifically, this processing is the same as that in Step S 12 described above with reference to FIG. 9 .
[0108] Referring to FIG. 10 again, in Step S 27 , the CPU 106 processes starting rotation of a scroll line, and moves the processing to Step S 28 . Specifically, this processing is the same as that in Step S 13 described above with reference to FIG. 9 .
[0109] Referring to FIG. 10 again, in Step S 28 , the CPU 106 determines whether a predetermined period of time has elapsed, and in a case where it has elapsed, the CPU 106 moves the processing to Step S 29 . When it has not elapsed, the CPU 106 moves the processing to Step S 28 . Specifically, this processing is the same as that in Step S 14 described above with reference to FIG. 9 .
[0110] Referring to FIG. 10 again, in Step S 29 , the CPU 106 processes stopping rotation of a scroll line, and moves the processing to Step S 30 . Specifically, this processing is the same as that in Step S 15 described above with reference to FIG. 9 .
[0111] Returning to FIG. 10 , in Step S 30 , the CPU 106 determines whether or not a predetermined symbol combination has been formed. In a case that the predetermined symbol combination has been formed, the flow proceeds to Step S 31 . On the other hand, in a case that the predetermined symbol combination has not been formed, the flow proceeds to Step S 34 . Specifically, this processing is the same as that in Step S 16 described above with reference to FIG. 9 .
[0112] Returning to FIG. 10 , in Step S 31 , the CPU 106 determines whether or not a symbol combination is a bonus. In a case that the symbol combination is a bonus, the flow proceeds to Step S 32 . On the other hand, in a case that the symbol combination is not a bonus, the flow proceeds to Step S 33 . Specifically, this processing is the same as that in Step S 17 described above with reference to FIG. 9 .
[0113] Referring to FIG. 10 again, in Step S 32 , the CPU 106 performs a bonus game processing, and moves the processing to Step S 44 . Specifically, this processing is the same as that in Step S 18 described above with reference to FIG. 9 .
[0114] Returning to FIG. 10 , in Step S 33 , the CPU 106 performs payout processing according to the symbol combination, and the flow proceeds to Step S 34 . Specifically, this processing is the same as that in Step S 19 described above with reference to FIG. 9 .
[0115] Referring to FIG. 11 , in Step S 34 , the CPU 106 determines whether S (a value of time limit) is zero or not. In a case where it is zero, the processing proceeds to Step S 35 . On the other hand, in a case where it is not zero, the processing proceeds to Step S 23 . Specifically, the CPU 106 refers to the value of the time limit of the sub game which is stored in a predetermined memory area in the RAM 106 , during counting, and determines whether the value is zero or not.
[0116] In Step S 35 , the CPU 106 determines whether or not the number of sub games played is more than 10 times. When it is more than ten times, the processing is moved in Step S 36 , and when it is not more than 10 times, the CPU 106 terminates the routine. Specifically, the CPU 106 refers to the value of the number of sub games played, which is stored in a predetermined memory area in the RAM 106 , and determines whether the value is more than ten times or not.
[0117] In Step S 36 , the CPU 106 provides an award corresponding to the number of games played. Specifically, the CPU 106 refers to the payout table for a sub game described later, and determines the amount of credits to be paid out. Upon finishing the processing in Step S 36 , the CPU 106 terminates the routine.
[0118] The payout table for a sub game shown in FIG. 14 is explained. The CPU 106 refers to the payout table for a sub game in order to determine the amount of credits corresponding to the value of the number of sub games played. For example, in the case where the number of sub games played is 11 times, the amount of credits is determined as “110”.
[0119] FIG. 15 is a diagram showing an example of a rendered image. In FIG. 15 , upon a start of the basic game with the sub game in FIG. 10 , the message “TIME LIMIT IS 60 SECONDS. PLAY 10 TIMES WITHIN 60 SECONDS AND YOU WIN AN AWARD” is displayed. The CPU 106 displays the image on the liquid crystal display 30 via the display/input controller 140 .
[0120] FIG. 16 illustrates an example of the rendered image. According to FIG. 16 , counting the time limit of the sub game and the number of sub games played in Step S 25 in the FIG. 10 are displayed. Counting of the time limit is displayed on the display area 81 and the number of sub games played is displayed on the display area 82 . The CPU 106 displays the image on the liquid crystal display 30 via the display/input controller 140 .
[0121] It should be noted that although in the present embodiment the amount of credits corresponding to the number of sub games played is 100 , 110 , 120 , and 130 , the present embodiment is not limited thereto. Therefore, in the case where the number of sub games played is more than a predetermined number, the CPU may provide an award corresponding to a predetermined award.
[0122] In addition, although in the present embodiment the time limit of the sub game is 60 seconds, the present embodiment is not limited thereto. Another value may be used.
[0123] Furthermore, in the present embodiment, processing for counting the time limit of the sub game is not supposed to be stopped during counting. However, the present embodiment is not limited thereto. Therefore, in the case where a predetermined symbol combination is achieved, processing for counting the time limit of the sub game may be stopped during counting.
[0124] In addition, although in the present embodiment, an example applied to a video reel slot machine is explained regarding the present invention, the present embodiment is not limited thereto, and for example, the present invention may be applied to a mechanical slot machine.
[0125] Furthermore, although in the present embodiment, an example using a slot machine (a so-called casino machine) in which a reel is automatically stopped after being rotated without using a stop button is explained regarding the present invention, the present embodiment is not limited thereto, and for example, the present invention may be applied to a slot machine (a so-called Pachinko-slot machine) in which reels are stopped in the order by which a player stops the reels by hand using the stop button.
[0126] While the embodiments according to the present invention have been described as mentioned above, it is understood that many changes and modifications may be made therein without departing from the spirit and scope of the present invention.
|
A gaming machine is provided, which includes a memory, an input device and a controller. The memory stores a number of played games and a predetermined time limit applied to the games. The input device accepts an operation to start a game. The controller is configured with logic to: (a) start the game when the input device has accepted the operation to start the game; (b) start counting up time at predetermined regular intervals to the time limit when a result of the game satisfies a predetermined condition; (c) increase the number of played games each time a game is started; and (d) when the number of played games is equal to or greater than a predetermined threshold at expiration of the time limit, pay a player in accordance with a predetermined award.
| 6
|
FIELD OF THE INVENTION
The present invention relates generally to data transmission, and in particular, to intrasystem communication in networks employing the international standard synchronous data hierarchy.
BACKGROUND OF THE INVENTION
To facilitate data communication over an international network, a standard has been promulgated to define the communication protocol for use in optical digital networks. This standard is discussed in detail in International Telecommunication Union, CCITT, General Aspects Of Digital Transmission Systems Recommendations G.707-G.709 (Geneva 1989), which is incorporated herein by reference. The CCITT standard known as the Synchronous Data Hierarchy ("SDH" or "the standard") defines a hierarchy of data containers and their pointers for standardized high bit rate transmission. Under the CCITT hierarchy, data signals are, in general, mapped into containers and then transmitted in transport module frames. Recommendation G.708 §2.2. The SDH defines several types of standard data containers, thereby allowing SDH to accommodate data signals operating at various standard bit rates. See, for example, CCITT FIG. 1-1/G.709.
Under one implementation of the standard that is experiencing widespread use, sixty-three 2 Mbit/s data signals are mapped into VC-12 containers, multiplexed and transmitted using transport module frames. The multiplexed VC-12 containers are first arranged into larger data containers known as C-4 containers. Each C-4 container is designed to fit into one transport module frame known as an STM-1 frame. Because of the respective sizes of the C-4 and VC-12, containers, sixty-three multiplexed VC-12 containers do not fit within one C-4 container and must be split over four consecutive C-4 containers, and therefore, four consecutive STM-1 frames. The four frame signal sequence is known as a multiframe signal.
Under the SDH standard, a C-4 container is converted into a VC-4 container before it is placed into an STM-1 frame. The VC-4 adds critical overhead data, including, in particular, data indicating the VC-4 container's position within the multiframe signal sequence. With this multiframe position data, referred to as multiframe synchronization (MFS) information, the terminal equipment at a node within the network receiving STM-1 signals can determine the beginning and end of a multiframe signal. Without the MFS information, the VC-12 data within the STM-1 signals cannot be accessed for reasons that will become clear hereinafter. The standard C-4 container is equivalent to a VC-4 in most respects, with the exception that the VC-4 also contains path overhead information.
The digital optical network that transports the SDH-formatted signals includes various nodes that provide maintenance, trafficking and error checking functions. One such node cross-connects data that is received as STM-1 frames on the VC-12 level. This node, called a cross connect node, rebuilds new STM-1 cells after cross-connection for transmission over the system. The node cross connect circuitry, however, does not cross-connect data directly from the STM-1 frames. Instead, the node circuitry must process the STM-1 frame to reproduce the data in the form of C-4 containers, which are simply multiplexed columns of VC-12 data. The presentation of data in C-4 container form facilitates cross-connecting on the VC-12 level.
Moreover, the node containing the cross connect circuitry does not receive data exclusively in the STM-1 format. In addition, the node may receive lower order signals, including, for example, plesiochronous 2 Mbit/s signals (CCITT standard), that must be mapped to VC-12 containers and multiplexed into standard container format. In either case, the cross-connecting circuitry is designed to handle data that has been converted to the standard C-4 container format.
The physical structure of the cross connect node may comprise several physical component racks or subracks in order to accommodate several input/output ports. In order to allow for flexibility in the physical configuration of the several subracks, the system must be capable of transmitting data considerable distances between subracks. Such flexibility necessitates intranodal or intrasystem communication over distances that may well be in excess of 10 meters. The transmission of standard containers or C-4 containers within the node at sufficiently high bit rates requires the use of communication links. Such intrasystem communication requires a communications protocol to transfer data between the input/output racks and the cross connect core circuitry.
One way to facilitate intrasystem communications is to transport the standard containers using the SDH standard STM-1 frame. Such an approach is logical considering that the standard container is already structured for use in this context. However, the SDH requires that each standard container, in other words, each group of multiplexed VC-12 containers, must first be mapped into a VC-4 container, which in turn requires the generation of a path overhead. See, for example, CCITT Recommendation FIG. 5-1/G.708. Because generation of the VC-4 and its path overhead requires additional hardware in the intrasystem link, it provides a less than optimal solution.
An alternative method is to employ a separate communications protocol to deliver the standard container intact. The implementation of a new protocol, however, would likely incur significant development costs and delays. Because such costs and delays would be incurred and a new protocol would presumably introduce non-standard codes into the data, this solution is also less than optimal.
It is therefore an object of the invention to provide a method and apparatus of transporting multiframe signals of VC-12 data in standard container form within a network node without requiring unnecessary hardware or significant development costs.
SUMMARY OF THE INVENTION
The present invention uses an innovative method of transmitting a multiframe signal comprising a plurality of standard containers within a network node or system employing an modified STM-1 frame. Each standard container is provided directly to a means for generating an STM-1 overhead. The STM-1 overhead generating means creates a modified STM-1 frame for transmission. To compensate for the fact that no VC-4 path overhead is generated, the multiframe information for the standard container is written to the STM-1 user definable F1 byte by a means for writing to the STM-1 user byte.
The modified STM-1 may then be transmitted to a remote part of the node or system. At the receiving end, the STM-1 overhead is removed and the contents of the F1 user byte obtained. The present invention facilitates savings in time and circuitry that would be required to build a proper STM-1 frame, including the VC-4 and its path overhead for every intrasystem transfer of standard container formatted data.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a digital cross connect node that utilizes the method of intrasystem communication according to the present invention;
FIG. 2 illustrates the functional steps required to prepare a standard container for intrasystem transmission according to the present invention;
FIG. 3 shows a standard C-4 container which is a part of a multiframe signal comprising sixty-three multiplexed VC-12 containers; and
FIG. 4 illustrates a communication link for use between two subracks of a system which uses the method of the present invention to prepare, transmit and receive standard containers within the system.
DETAILED DESCRIPTION
The present invention provides a novel communication link that may be utilized in a cross connect node of a communication network. The cross connect node switches data at the VC-12 level that is either received as STM-1 frames or lower order data signals.
FIG. 1 illustrates a digital cross connect node or system 100 which utilizes a method of intrasystem communication according to the present invention. The cross connect system 100, provides controlled cross-connection of data containers at the VC-12 level.
In general, the cross connect system 100 comprises the following components arranged in subracks. Up to n input/output subracks 102 1 . . . 102 n are connected to the optical network, not shown, through input ports 103 1 . . . 103 n and output ports 104 1 . . . 104 n . Transmission lines 105 1 . . . 105 n connect and facilitate data communication between the input/output subracks 102 1 . . . 102 n and the cross-connect core subrack 106. Transmission lines 105 1 . . . 105 n may suitably be coaxial fiber with a length of on the order of 10 meters, or optical fiber that may be substantially greater than 10 meters. The use of such transmission lines allows for flexible physical configuration of the various subracks. The cross connect core subrack 106 includes circuitry capable of column switching VC-12 containers presented in standard C-4 container format, employing a time-space-time Clos network. Circuitry capable of performing such functions is well known in the art.
There may be up to as many as two hundred fifty-six input/output subracks 102 1 . . . 102 n . Systems having greater capabilities and incorporating more subracks are also contemplated by the current invention. The cross connect system 100 further contains a control portion, not shown, which is connected to each of the input port subracks 102 1 . . . 102 n , and the cross-connect core subrack 106. The control section may comprise a local area network control system that initializes, configures, and manages the various subracks in the system.
Incoming signals arrive through facilities connected to ports 103 1 . . . 103 n of the input port subracks 102 1 . . . 102 n . The incoming signals may suitably be STM-1 signals such as those discussed above, or signals containing lower order forms of data, such as 2 Mbit/s CEPT-1 signals. If the incoming signals are STM-1 frames comprising multiframe signals, the input port processes the STM-1 frames into a multiframe signal of standard containers having a structure as discussed below in connection with FIG. 3. If, however, the incoming signals are lower order signals, they may be mapped into VC-12 containers which are then multiplexed to form a multiframe signal of standard containers.
As discussed above, a standard container may suitably comprise sixty-three multiplexed VC-12 containers and typically includes nine unused columns such that the standard frame comprises the dimensions of the STM-1 frame payload portion. The standard containers are transmitted over lines 105 1 . . . 105 n to the cross connect core 106 using modified STM-1 frames according to the method of the present invention such as those produced by the method discussed below in conjunction with FIG. 2.
The standard containers are received and removed from the modified STM-1 frames at the cross connect core subrack 106. The standard containers enter the cross connect core subrack 106 and are switched at the VC-12 level. In other words, individual VC-12s are extracted from the standard containers and combined to form new standard containers. The new standard containers are then transported back to the input/output subracks 102 1 . . . 102 n , using modified STM-1 frames according to the present invention. The input/output subracks 102 1 . . . 102 n may then process the STM-1 frames into either standard STM-1 frames or any other suitable data configuration, such as CEPT-1 signals, for transmission over the network.
FIG. 2 illustrates the novel method of preparing a standard container for intrasystem transmission in a modified STM-1 frame. The resulting modified STM-1 frame may suitably transfer data within a system such as the one discussed in connection with FIG. 1 above. A multiframe signal is first provided in the form of a plurality of standard containers 151 1 . . . 151 n , which may suitably be four standard C-4 containers. As discussed above, an input port subrack may contain circuitry capable of providing such containers.
FIG. 3 shows, in detail, a standard container 310, or C-4 container, which may be the first C-4 container 151 1 of a multiframe signal as illustrated in FIG. 2, above. The arrangement of VC-12 data in such containers is well known in the art. The C-4 container 310 is composed of 261 byte columns as illustrated, for example, by byte column 312. The C-4 container 310 contains nine rows of bytes. Of the 261 byte columns, the first nine columns, illustrated as block 314 are not used for data, and may comprise fixed stuff. The remaining columns are split into four groups of sixty-three byte columns each. The lower order VC-12 containers may be time division multiplexed into these four groups of byte columns. As discussed above, however, the C-4 container 310 is only one of four consecutive C-4 containers required to hold sixty-three VC-12 containers. The C-4 container size is limited by the size of the STM-1 frame. See, for example, CCITT Recommendation G.709 §2.
If the C-4 container 310 is the first or second container in the multiframe signal, the container will include pointers that point to the beginning of each of the VC-12s within the multiframe. The pointers for the VC-12 containers are located within the first row of bytes and always occupy the bytes in the first sixty-three columns of data following the nine columns of fixed stuff, as illustrated by block 316. The pointers are located only within the first and second C-4 container of a multiframe signal. Each pointer points to the VC-12 within its column. The pointers are required because the VC-12s are not phase aligned, and therefore begin at different locations within the four C-4 containers of the multiframe signal. See CCITT Recommendation G.709 §3.3, FIGS. 3-13
It will be understood that the use of a multiframe to transmit sixty-three VC-12 containers is given by way of example only. Other multiframe configurations may suitably be used, including, for example, a multiframe signal required to transmit a plurality of VC-11 containers.
Returning to FIG. 2, the C-4 containers 151 1 . . . 151 4 are processed individually, starting with the first container 151 1 . The first standard C-4 container 151 1 of the multiframe signal is converted to an STM-1 frame 152 1 by adding an STM-1 section overhead 153 1 . The contents of the section overhead 153 1 are dictated by the CCITT standard, and comprise frame alignment information, parity check data, and protection switching information. See CCITT Recommendation G.708 §5.2.1 & FIG. 3-4/G.708. The STM-1 section overhead further contains a user definable byte, or F1 byte 154. Use of the F1 user byte 154 is not otherwise defined or reserved by the SDH standard or CCITT recommendations. According to the method of the present invention, the MFS information 155, which indicates the relative position of the standard container within the multiframe signal, is inserted or written to the F1 user byte 154.
The MFS information 155 may be represented in binary form in the following manner. The MFS information 155 may, for example, uniquely identify each distinct frame in the multiframe. In other words, for the first standard container 151 1 of the multiframe, an MFS indicator may suitably be 00, for the second standard container 151 2 , the MFS indicator may suitably be 01, for the third standard container 151 3 , the MFS indicator may suitably be 10, and so forth. Alternatively, the MFS information may simply provide a flag 1 bit for the first standard container 151, and provide a not-flag 0 bit for the remaining containers. The F1 user byte contains eight bits, thus allowing several options for representing the MFS information.
An STM-1 frame may then be transmitted by means well known in the art.
The method discussed above provides a simple way of preparing standard containers and multiframe synchronization information into STM-1 frames for intrasystem transmission. Once the STM-1 frame is generated, it may be transmitted within a system as discussed above in connection with FIG. 1.
The method of the present invention provides an improvement by eliminating the step of creating a VC-4 container, in other words, writing the VC-4 path overhead. The SDH standard requires the VC-4 for network transmissions. This step is not required in intrasystem communications because most of the information ordinarily contained within the VC-4 path overhead is only required for node to node network communication. The MFS information normally located in the VC-4 path overhead, however, is still needed within the system. According to the present invention, the MFS information may suitably be written to the STM-1 overhead, which requires relatively little processing compared to generating an entire VC-4 path overhead. Because substantial time delay and one or more pieces of hardware are associated with the generation of the VC-4 path overhead, the method of the present invention provides the advantage of reducing the hardware and time required to transmit the data in the standard containers 151 1 . . . 151 4 .
FIG. 4 shows a communicative link 400 operable to create, transmit and receive the modified STM-1 frames such as STM-1 frame 152 1 discussed above in connection with FIG. 2. The apparatus illustrated in FIG. 4 may suitably be employed in a node of a communication network such as the cross connect node 100 illustrated in FIG. 1 above. It will be understood that the generation and configuration of any of the containers or modules defined by the standard from either raw data or another container or module is well known. See generally CCITT Recommendations, above. The specific hardware required to perform any required data or pointer manipulation between defined blocks or modules will be readily apparent to one skilled in the art. It will be understood that each functional block is connected to system timing circuitry, not shown, which provides sequence and timing control to each block.
A data source 402 is connected to a data conversion means 406. The data source 402 may suitably be a circuit that receives STM-1 frames from an external network, not shown. In such a case, the data conversion means 406 would comprise circuitry for processing the STM-1 frames into standard containers, for example, C-4 containers. Alternatively, the data source 402 may suitably receive data in the VC-12 form or lower. In such a case, the data conversion means 406 would comprise circuitry for multiplexing and mapping such data into a C-4 container. Circuitry capable of receiving data in those forms and subsequently converting the data into C-4 or other standard containers is well known in the art.
The data conversion means 406 is operably connected to provide data in the form of a standard container to an STM-1 processor 408. The STM-1 processor 408 comprises circuitry for receiving data, generating an STM-1 section overhead and providing at the output an STM-1 frame comprising the data and the section overhead according to the CCITT standard. The generation of STM-1 frames is a basic function in SDH communication systems and is readily accomplished by one of ordinary skill in the art. See CCITT Recommendation G.708 §5.2.
A source of multiframe synchronization information 410 is connected to a link processor 412 and the data conversion means 406. The source 410 provides the MFS information to the link processor 412 and may comprise, for example, a portion of the system timing circuit. Whether or not the source of MFS information 410 comprises the system timing circuit, it will be understood that the timing circuitry may otherwise be connected to the various functional blocks for sequence and timing control. The link processor 412 is also connected to the STM-1 frame processor 408. The link processor 412 is operable to write information to the F1 user byte of the STM-1 overhead through interaction with the STM-1 frame processor. The hardware necessary to write information to the F1 user byte would be apparent to one skilled in the art.
The STM-1 frame processor 408 is further connected to provide STM-1 frames of data to electrical-to-optical conversion means 414. The electrical-to-optical conversion means 414 is connected through an optical link 416, which may be optical fiber of a variable length of greater than 10 meters, to an optical-to-electrical conversion means 418. The optical-to-electrical means 418 may, for example, represent the input to the cross connect subrack 106 discussed above in connection with FIG. 1.
At a remotely located subrack, the optical-to-electrical conversion means 418 is coupled to a second STM-1 frame processor 420. The second frame processor 420 is operable to receive STM-1 frames and remove the STM-1 section overhead from the data contained therein. Circuitry capable of performing the foregoing is well known in the art. The second STM-1 frame processor 420 is operably connected to provide the resulting data to a data processing means 426. The data processing means 426 may comprise circuitry capable of switching data at the VC-12 level. Alternatively, the data processing means 426 may comprise any circuitry that processes data on the VC-12 level.
The second STM-1 frame processor 420 is further connected to a second link processor 422. The link processor 422 is connected to the data processing means 426. The second link processor 422 is operable to extract data contained in the F1 user byte of the STM-1 frame. The F1 user byte is intended for user implementation and therefore circuitry capable of extracting such information would be readily apparent to one of ordinary skill in the art.
In operation, data is received from data source 402 and processed by data conversion means 406 in an ongoing manner. Upon command of the system timing circuitry, the source of MFS information 410 provides a signal indicating the beginning of a multiframe signal to the data conversion means 406 and the link processor 412. The data conversion means 406 then formulates and transmits the first standard container of the multiframe to the STM-1 frame processor 408. The STM-1 frame processor 408 then builds a STM-1 section overhead for the data. Concurrently, the link processor 412 writes the MFS information corresponding to the beginning of a multiframe to the F1 user definable byte of the STM-1.
This process may then be repeated for the remaining frames in the multiframe. For subsequent containers, however, the source of MFS information 410 provides a different signal, indicating that the frame is not the first container of a multiframe signal. The data conversion means 406 then formulates subsequent standard containers of the multiframe and the STM-1 frame processor 408 generates corresponding section overheads, including the MFS information. Further details on the preparation of the modified STM-1 frames according to the present invention is discussed above in connection with FIG. 2.
The modified STM-1 frames generated by the STM-1 frame processor 408 as discussed above are transferred through the electrical-to-optical conversion means 414 and the optical link 416 to an optical-to-electrical conversion means 418 located at another subrack within the system. At the other subrack, the modified STM-1 signals enter the second frame processor 420 wherein the section overhead of each STM-1 signal is interpreted. The frame processor 420 thereafter provides the standard containers from the STM-1 signals to the data processing means 426. Concurrently, the link processor 422 retrieves from the frame processor 420 the contents of each F1 user byte. The link processor 420 provides the F1 contents, which comprises the MFS information, to the data processing means 426. The data processing means 426 may thereafter access and process the data in the standard containers using the MFS information retrieved from the F1 user byte.
In an alternative embodiment of the communication link 400, the data may be transmitted as electrical signals instead of optical signals. In such an embodiment, the electrical-to-optical conversion means 414 would be replaced by a line transmitter, the optical link 416 would be replaced by coaxial cable, and the optical-to-electrical conversion means 418 would be replaced by a line receiver.
It will be understood that use of the invention for intrasystem optical communication is not limited to a cross connect system in an optical network but can relate to any system in an optical network in which optical links connect the various parts of a localized system run from the same clock. By using the STM-1 frame to transmit the MFS information, the need for generating the VC-4 path overhead to transmit a standard container of data is not needed.
It will be further understood that the above-described arrangements of the invention are merely illustrative. Other arrangements may be devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.
|
The present invention provides an innovative method of transmitting a multiframe signal generated in accordance with the international standard synchronous data hierarchy. Multiframe signals comprising a plurality of standard containers may be transmitted within a network node or system employing an STM-1 frame in a novel manner. Each standard container is provided directly to an STM-1 frame processor. The STM-1 frame processor creates a modified STM-1 frame for transmission. Because the VC-4 path overhead is not generated, the multiframe synchronization (MFS) information for the standard container is written to the STM-1 user definable F1 byte by a link processor. The modified STM-1 is then converted to an optical signal and transmitted to a remote part of the node where the STM-1 is received. The STM-1 overhead is thereafter removed and the contents of the F1 user byte is obtained. The receiving node uses the MFS information to access the data contained within the multiframe signal.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
CLAIM TO PRIORITY
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
REFERENCE TO A MICROFICHE APPENDIX
Not Applicable.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to a corrosion inhibiting composition for use in commercial, institutional, and industrial water systems. The compositions comprise a mixture of (1) a fatty acid ester, and (2) a polyethylene glycol ester. These compositions are useful in inhibiting the corrosion of metals such as steel, copper, and brass, which are exposed to water.
(2) Description of the Related Art
The pipes, heat exchangers, equipment, and other components of commercial, institutional and industrial water systems, are often made of metal such as steel, copper, and brass, which corrode after time when subjected to oxygen, moisture, and corrosive gases. Examples of such industrial systems include cooling water systems, boiler systems, including steam condensate, heat transfer systems, refinery systems, pulp and paper making systems, food and beverage systems, and mechanical coolant systems. Examples of institutional and commercial systems include HVAC systems, sterilizers, and kitchen steam tables.
Corrosion of metallic components in these systems can cause system failures and shutdowns. In addition, corrosion products accumulated on the metal surface decreases the rate of heat transfer between the metal surface and the heat transfer medium, such as water, which reduces the efficiency of the system.
In order to inhibit corrosion of the metal surfaces in these systems, especially of steam condensate return lines, volatile amines, filming amines, or amine derivatives are added to water and steam in such systems, e.g. to the feedwater or other injection points used for this purpose. However, amines may have limitations from an environmental or toxicity standpoint, especially in humidification and food contact.
U.S. Pat. No. 5,849,220 discloses the use of non-amine filming inhibitors, which are a combination of a surfactants comprising (1) at least one sorbitan fatty acid ester surfactant, and (2) at least one polyoxyethylene derivative of a sorbitan fatty acid ester. These non-amine inhibitors have environmental benefits because they are less toxic, more biodegradeable, and can be used in many products made for human consumption, because they have a less objectionable odor and taste.
All citations referred to under this description of the “Related Art” and in the “Detailed Description of the Invention” are expressly incorporated by reference.
BRIEF SUMMARY OF THE INVENTION
This invention relates to a corrosion inhibiting composition for use in inhibiting the corrosion of metallic surfaces exposed to water comprising a mixture of:
(1) a fatty acid ester, and
(2) a polyethylene glycol ester.
These compositions are useful in inhibiting the corrosion of metals such as steel, copper, and brass, which are exposed to water or other industrial fluids.
The examples herein illustrate that the combination of esters reduces corrosion in steel, copper, and other metallic surfaces, and that this result is unexpected, or synergistic, in view of the limited inhibition effect of the components alone. In addition to the environmental advantages of the corrosion inhibiting compositions described in U.S. Pat. No. 5,849,220, which contains a polyoxyethylene derivative of a sorbitan fatty acid ester, instead of a polyethylene glycol dioleate, the compositions of the subject invention provide improved corrosion resistance when compared to the corrosion inhibiting compositions described in U.S. Pat. No. 5,849,220.
The invention also relates to a method of reducing corrosion on metallic surfaces exposed to water in an industrial, commercial or institutional system, which comprises adding a corrosion inhibiting amount of the composition to the water or steam at an injection point, such that the corrosion inhibiting composition comes into contact with the metal surface.
Examples of such commercial, institutional and industrial systems, which contain metallic components exposed to water, include, for example, cooling water systems, boiler systems, heat transfer systems, refinery systems, pulp and paper making systems, food and beverage systems, mechanical coolant systems, water treatment systems, refinery and oil field processes, metal making, mining and ore processing applications, beverage production, hospital sanitation systems, and pharmaceutical manufacturing.
The corrosion-inhibiting composition is effective over a broad pH range, especially under slightly acidic solutions, preferably between a pH of 5 to 9, more preferably from about 5 to about 7, and most preferably from about 5.5 to about 7. The temperature of the industrial fluid typically ranges from about 10° C. to about 250° C., more typically from about 15° C. to about 95° C. The corrosion inhibiting composition is injected directly into the vapor phase, liquid phase, or both phases of the industrial system.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Not Applicable.
DETAILED DESCRIPTION OF THE INVENTION
The detailed description and examples will illustrate specific embodiments of the invention will enable one skilled in the art to practice the invention, including the best mode. It is contemplated that many equivalent embodiments of the invention will be operable besides these specifically disclosed. All units are in the metric system and all percentages are percentages by weight unless otherwise specified.
Although other fatty acid esters are useful in formulating the corrosion inhibiting compositions, preferably the fatty acid ester is a sorbitan ester of a saturated fatty acid having from 16 to 18 carbon atoms. Most preferably, the sorbitan fatty acid ester is selected from the group consisting of sorbitan monostearate, sorbitan monopalmitate, sorbitan monooleate, sorbitan sesquioleate, and mixtures thereof. Examples of suitable sorbitan fatty acid esters are sold under the following trademarks: SPAN 60 and ARLACEL 60 (sorbitan monostearate), SPAN 40 and ARLACEL 40 (sorbitan monopalmitate), SPAN 80 and ARLACEL 80 (sorbitan monooleate), and ARLACEL C and ARLACEL 83 (sorbitan sesquioleate).
Although other polyalkalylene glycol esters are useful in formulating the corrosion inhibiting compositions, preferably the polyalkylene glycol ester is the dioleate of polyethylene glycol. The polyethylene glycol dioleates are prepared, according to well known methods, by esterifying a polyethylene glycol, having an average molecular weight of 400 to 800, more preferably from about 500 to 700, most preferably about 600, with oleic acid. Examples of polyethylene glycol dioleates include PEGOSPERSE 600 D diester sold by Lonza
The weight ratio of the fatty ester to polyalkylene glycol ester is typically from about 1:1 to 1:10, preferably from about 1:1 to about 1:4, more preferably from about 1:2 to about 1:4.
The dosage of the corrosion inhibiting composition ranges from about 1 ppm to about 60 ppm, based upon the amount of active components (1) and (2) in the corrosion inhibiting composition.
The compositions may contain one or more optional components, for instance thickeners and preservatives.
Abbreviations
The following abbreviations are used:
PGD polyethylene glycol dioleate sold under the tradename PEGOSPERSE 600DO by Lonza
SME sorbitan monoester of stearic acid, sold by ICI under the trade name SPAN 60.
PAG-SME oxyethylene adduct of SME prepared by reacting about 20 moles of ethylene oxide with SME, sold under the trade name TWEEN 60, which is used in the corrosion inhibiting compositions of U.S. Pat. No. 5,849,220.
EXAMPLES
While the invention has been described with reference to a preferred embodiment, those skilled in the art will understand that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. In this application all units are in the metric system and all amounts and percentages are by weight, unless otherwise expressly indicated.
To eight-ounce jars were added 230 mL of deionized water and the corrosion-inhibiting treatment, which was omitted for the blank. The solutions were heated to 60° C. to 66° C. and held at that temperature. A pre-weighed C-1010 mild steel corrosion coupon was added to each jar, and the jars were closed with caps perforated with quarter-inch holes to allow contact with air and atmospheric carbon dioxide. The jars were agitated at 145 to 155 cycles per minute for 48 hours. At the end of the contact period the coupons were removed, corrosion products were removed by blasting with glass beads, and the coupons were re-weighed. The dimensional loss rate was calculated from the weight loss.
Examples (Control A, Comparisons A and B, and Example 1)
These examples compare SME alone and PGD alone to a mixture of SME and PGD at a weight ratio of 1 to 4. The results are summarized in Table I.
TABLE I
(Comparison of SME, PGD, and Mixture)
SME
PGD
Ratio
Corrosion Rate
Example
(ppm)
(ppm)
SME/PGD
(mpy)
Control A
0
0
0
35.32
Comparison A
200
0
0
0.50
Comparison B
0
200
0
3.41
1
0
0
40/160
0.10
These examples illustrate the synergistic effect of using a mixture of SME and PGD rather than SME or PGD alone.
Examples Control B, Comparison C, and Example 2
These examples compare SME-PGD to SME-PAG as described in U.S. Pat. No. 5,849,220.
TABLE II
SME
PAG
PGD
Corrosion Rate
Example
(ppm)
(ppm)
(ppm)
(mpy)
Control B
0
0
0
16.52
Comparison C
100
100
0
0.34
2
40
0
160
0.05
These examples indicate that the mixture of SME and PGD at a 1:4 ratio is more effective than the mixture of SEM and PAG at the same dosage in reducing corrosion.
Examples 3-5
These examples illustrate the effectiveness of SME-PGD at different ratios of SME to PGD.
TABLE III
SME
PGD
Ratio
Corrosion Rate
Example
(ppm)
(ppm)
(ppm)
(mpy)
3
100
100
1:1
0.28
4
66.6
133.4
1:2
0.24
5
40
160
1:4
0.10
Examples 3-5 illustrate the effect of using different ratios of SME to PGD. The data indicate that the ratio of 1:2 to 1:4 performs the best.
Evaluation of the Foaming Properties of the Corrosion Inhibiting Compositions
The foaming properties of the corrosion inhibiting compositions were also evaluated by a modified “Ross-Miles Foam Test”. This compares the foaming tendencies of different products or surfactants in water at various temperatures. The method was used to demonstrate/evaluate foaming tendency of products/treatment dosages.
The test is carried out as follows:
1. 500 ml. of water (the water should be representative of the system 1 ) was added to a 1000 ml. graduated cylinder having a cylinder diameter 65 mm. Then 18.0 ppm ortho phosphate is added to the cylinder as a buffer. The resulting pH was about 10.3 and the test was carried out at a temperature of 66° C.-67° C.
Experimental Boiler Water Treated With Caustic and Sodium Phosphate.
2. The recommended treatment dosage was added to 500 ml. of the water sample from step #1 to measure foaming tendency.
3. Then cylinder with contents is shaken vertically at the specified temperature ten times (the times shaken equals the number of cycles). After the tenth time, the initial foam height (t=0) is recorded in mL Then the foam level at t=5 minutes and t=30 minutes is recorded. Whether the foam broke in less than a five minute interval is also noted.
4. The initial appearance of test solution is recorded.
Example (Control, Comparison D, and 8)
(Comparison of Foaming Properties of SME-PGD and SME-PAG)
In these examples, the foaming properties of a mixture of SME and PGD was compared to a mixture of SME and PAG as described in U.S. Pat. No. 5,849,220. The test conditions and results of the foaming test are summarized in Table IV. The foam was measured after 10 cycles.
TABLE IV
ppm
ppm
Foam Height mL
SME/PAG
SME/PGD
After
After
Example
ratio
ratio
Initial
5 Min.
30 Min
Comparison D
1.5
/
1.5
1
:
1
0
23
19
5
8
0
0.6
/
2.4
1
:
1
Trace
Trace
None
The test results indicate that the composition containing the SME/PGD produced less foam than the prior art composition. This is significant because it is anticipated that, in many systems, small quantities of the corrosion inhibiting composition will return to the boiler with the steam condensate. If it induces foaming, the foam will carry boiler water with its attendant dissolved solids through the steam-water separation equipment typically in the boiler drum. These impurities in the steam typically deposit in downstream equipment and cause damage such as unbalanced turbines, blocked valves and the like as well as corrosion. Consequently, minimal foaming tendency is desired.
|
This invention relates to a corrosion inhibiting composition for use in commercial, institutional, and industrial water systems. The compositions comprise a mixture of (1) a fatty acid ester, and (2) a polyethylene glycol ester. These compositions are useful in inhibiting the corrosion of metals such as steel, copper, and brass, which are exposed to water.
| 2
|
BACKGROUND OF INVENTION
[0001] This invention relates to the use of one or more small vehicle-mounted wind turbines connected to one or more small generators to generate electricity for use by a vehicle when in motion. Specifically, the wind turbines are located in an area of wind recirculation in between the segments of an articulated vehicle combination, or in the aerodynamic wake behind the vehicle.
SUMMARY
[0002] With the advent of modern Hybrid Electric Vehicles, much development has occurred in the art having to do with recapturing vehicle kinetic energy and regeneration of that energy into a useable form. The primary focus of development has been in the area of regenerative vehicle braking. Other areas of development have focused upon utilizing secondary sources of available energy, such as solar energy or wind energy.
[0003] In many prior-art developments concerning the use of wind energy to provide power to Hybrid Electric Vehicles, the inventions as set forth have consumed more energy than they have produced. Specifically, they have involved vehicles having wind turbines located in the slipstream above or in front of the vehicle, or equivalently, having ducts leading from those locations to wind turbines located elsewhere on the vehicle. Because these turbines, or the ducts leading to them, were continually in the vehicle slipstream, they caused a net increase in the amount of power required to drive the vehicle to overcome air resistance. Constrained by the first law of thermodynamics, the wind turbines consumed more energy than they returned to the vehicle. The simplest model of these inventions would be a vehicle composed of a turbine, a generator, an electric motor, and wheels. The electric motor would drive the wheels to push the vehicle forward, which would cause the turbine to spin the generator in order to provide electricity to the electric motor.
[0004] One or two of these inventions have had some merit, in that the turbine has had provisions to accept an air stream from vectors other than straight forward. That is to say, if the vehicle experienced a strong sidewind, the turbine was capable of capturing the component of the air stream not generated by its own motion, and converting that into useable energy. Under conditions of a strong headwind, a vehicle equipped with a wind turbine may even be able to generate enough energy from the vector component of the air stream not generated by its own motion, to overcome the resistance caused by the movement of the additional frontal area due to the turbine through that slipstream. This would be the thermodynamic equivalent of a sailboat tacking upwind.
[0005] In the area of development having to do with Hybrid Electric Vehicles and regenerative braking, the focus has thus far been upon vehicles having a city or urban driving cycle. These vehicles, typically passenger vehicles and delivery vehicles, use large amounts of energy accelerating and accumulating kinetic energy, which is then lost upon braking. The objective of regenerative braking is to return a portion of that kinetic energy to storage in the form of electrical potential for subsequent use. For vehicles having a highway or long-haul driving cycle, such as line-haul trucks, the driving profile involves considerably less braking, and more expenditure of energy overcoming wind resistance.
[0006] There exists an area of air movement relative to a moving vehicle that heretofore remains unexploited as a source of energy, and which presents the possibility of extracting energy from said air movement without requiring additional energy in order to move the vehicle. To an even greater degree of benefit, extracting energy from this area of air movement may even decrease the amount of energy required to move the vehicle. That area of air movement is the area of recirculation in between the segments of an articulated vehicle combination, or in the aerodynamic wake behind the vehicle.
[0007] Articulated moving vehicles, such as highway tractor and semi-trailer combinations, possess a large gap between the tractor and trailer due to constraints having to do with articulation at low speeds. At high speeds, air passing over and around the vehicle recirculates within this gap. As a moving fluid exerts less pressure and as a greater velocity of relative movement occurs near the rear side of the tractor cab due to this recirculation, the net pressure differential between the forward side of the tractor portion of the vehicle and the rearward side of the tractor portion of the vehicle is increased as a result of this recirculation. Extracting energy from this recirculating air mass not only provides a source of energy, but also reduces this net pressure differential, thus reducing overall wind resistance. An additional principle in operation under this circumstance is based on the fact that this rotating air mass further disturbs the air flowing past the gap, and as a result promotes turbulent air flow relative to the vehicle, thereby increasing overall wind resistance.
[0008] A similar principle operates within the wake of the moving vehicle. At that point, the airflow past the vehicle has generally deteriorated to a turbulent state, such that less steady-state recirculation is taking place. However, there is still a significant component of steady-state recirculation combined with shedding vortices. This steady-state component of recirculation again causes the exertion of less pressure by the moving fluid, resulting in an increase in pressure differential between the forward side of the moving vehicle and the rearward side of the moving vehicle. By extracting energy from the recirculating air mass, the pressure differential between the forward side of the moving vehicle and the rearward side of the moving vehicle is reduced. This again reduces overall wind resistance.
[0009] In no way does the present invention claim to extract enough energy from the recirculating air mass to fully propel the vehicle. If it did, it would be a violation of the first law of thermodynamics. However, sufficient energy may be extracted from these regions of recirculation using small, strategically placed wind turbines coupled to efficient generators to generate fifty to one hundred amperes of useable electrical power. This figure assumes a recirculating wind speed of approximately twenty meters per second, a turbine diameter of approximately half a meter, and sea-level standard atmospheric conditions. The power generated may be used to supply vehicle parasitic loads, or it may be used to partially charge vehicle batteries.
[0010] The multiple embodiments of the invention disclosed herein each involve the use of one or more such wind turbine driven generators in certain strategic locations, such as directly behind the cab of a highway tractor and semi-trailer combination, between the frame rails and skirts of such a vehicle, or in the wake area located behind a given vehicle. A single axial flow turbine driven generator, an array of such generators, or even a multi-stage axial flow turbine driven generator may be used.
DRAWINGS
[0011] FIG. 1 —A side view of an articulated vehicle having a gap and an area of air recirculation therein.
[0012] FIG. 2 —A side view of a vehicle having an area of air recirculation in its wake area.
[0013] FIG. 3 —A view of a wind turbine coupled to an electrical generator.
[0014] FIG. 4 —A view of a first embodiment of the invention.
[0015] FIG. 5 —A view of a second embodiment of the invention.
[0016] FIG. 6 —A view of a third embodiment of the invention.
[0017] FIG. 7 —A side view of a vehicle having an area of recirculation extending through its chassis.
[0018] FIG. 8 —A partial view of a fourth embodiment of the invention.
[0019] FIG. 9 —A view of a fifth embodiment of the invention.
[0020] FIG. 10 —A power diagram of a vehicle having a wind turbine coupled to an electrical generator.
DETAILED DESCRIPTION
[0021] The vehicle 101 shown in FIG. 1 has a cab 102 attached to a chassis 103 , and is adapted to pull a semi-trailer 105 , which semi-trailer 105 is partially shown. FIG. 1 further shows airflow 106 relative to the moving vehicle 101 . Located between the cab 102 of the vehicle 101 and the semi-trailer 105 attached to the vehicle 101 , is a vehicle gap 107 , within which exists an area of air recirculation 108 .
[0022] The vehicle 101 shown in FIG. 2 has a cab 102 attached to a chassis 103 , and is provided with a cargo-carrying body section 104 . Airflow 106 is shown relative to the moving vehicle 101 , behind which vehicle 101 exists an area of recirculation 108 .
[0023] FIG. 3 shows a wind turbine 109 having turbine blades 110 coupled to a generator 112 by means of a shaft 113 . The wind turbine 109 may be provided with a turbine housing 111 , within which the turbine blades 110 rotate. The wind turbine 109 is supported by a turbine mounting 115 . The generator 112 provides electrical power by means of electrical leads 114 .
[0024] The vehicle 101 shown in FIG. 4 has a cab 102 attached to a chassis 103 , similar to the vehicle 101 shown in FIG. 1 . The vehicle 101 shown in FIG. 4 is again adapted to pull a semi-trailer 105 , which semi-trailer 105 is partially shown. FIG. 4 further shows the airflow 106 relative to the moving vehicle 101 , the vehicle gap 107 , and the area of air recirculation 108 . Attached to the cab 102 , and located within the area of air recirculation 108 , is a wind turbine 109 and generator 112 . By means of the wind turbine 109 and generator 112 , a portion of the energy contained within the recirculating air 108 is converted to electrical energy for use by the vehicle 101 .
[0025] The vehicle 101 shown in FIG. 5 has a cab 102 attached to a chassis 103 , and is provided with a cargo-carrying body section 104 , similar to the vehicle 101 shown in FIG. 2 . FIG. 5 shows the airflow 106 relative to the moving vehicle 101 , as well as an area of recirculation 108 . Attached to the cargo-carrying body section 104 , and located within the area of air recirculation 108 , is a wind turbine 109 and generator 112 . By means of the wind turbine 109 and generator 112 , a portion of the energy contained within the recirculating air 108 is converted to electrical energy for use by the vehicle 101 .
[0026] FIG. 6 shows a rear view of a vehicle 101 having a cab 102 attached to a chassis 103 . Similar to the vehicle 101 in FIG. 1 , the vehicle 101 in FIG. 6 is adapted to pull a semi-trailer 105 , which is not shown in FIG. 6 . Airflow 106 is shown entering the area of air recirculation 108 . An array of wind turbines 109 and generators 112 are attached to the cab 102 of vehicle 101 . By means of the wind turbines 109 and generators 112 , a portion of the energy contained within the recirculating air 108 is converted to electrical energy for use by the vehicle 101 .
[0027] The vehicle 101 shown in FIG. 7 has a cab 102 attached to a chassis 103 , and is adapted to pull a semi-trailer 105 , similar to the vehicle 101 shown in FIG. 1 . The semi-trailer 105 is not shown in FIG. 7 . The vehicle 101 is provided with chassis skirts 116 and deck plates 117 . Airflow 106 is shown entering an area of recirculation 108 , which area of recirculation 108 extends through the chassis 103 , passes within the area defined by the chassis skirts 116 , and flows upwards through the deck plates 117 .
[0028] FIG. 8 shows a partial view of a vehicle 101 , including a partial outline view of a cab 102 attached to a chassis 103 , which chassis 103 is also partially shown. Similar to the vehicle 101 shown in FIG. 7 , the vehicle shown in FIG. 8 is provided with chassis skirts 116 and deck plates 117 . Wind turbines 109 and generators 112 are attached to the chassis 103 , and are located beneath the deck plates 117 and in between the chassis skirts 116 .
[0029] FIG. 9 shows a rear view of a vehicle 101 having a cab 102 attached to a chassis 103 . Similar to the vehicle 101 shown in FIG. 1 , the vehicle 101 shown in FIG. 9 is adapted to pull a semi-trailer 105 , which is not shown in FIG. 9 . Airflow 106 is shown entering the area of air recirculation 108 . A multi-stage wind turbine 118 is attached to the cab 102 of the vehicle 101 , which multi-stage wind turbine 118 is provided with multiple sets of turbine blades 110 . The multiple sets of turbine blades 110 rotate within the turbine housing 111 upon a shaft 113 , which shaft 113 in turn drives the generator 112 , thereby converting a portion of the energy contained within the recirculating air 108 into electrical energy for use by the vehicle 101 .
[0030] FIG. 10 shows a vehicle 101 having a cab 102 attached to a chassis 103 . Similar to the vehicle 101 shown in FIG. 1 , the vehicle 101 shown in FIG. 10 is adapted to pull a semi-trailer 105 , which is not shown in FIG. 10 . The vehicle 101 is provided with a wind turbine 109 , which wind turbine 109 drives a generator 112 . The vehicle 101 is further provided with an engine 119 for propulsion, which engine 119 also drives a primary generator 120 . The vehicle 101 may also be provided with an auxiliary electric motor 122 for propulsion. The vehicle 101 also possesses one or more vehicle batteries 121 , and vehicle parasitic loads 124 . A vehicle system controller 123 is connected to and manages power flow to and from each of the generator 112 driven by the wind turbine 109 , the primary generator 120 driven by the engine 119 , the vehicle batteries 121 , the auxiliary electric motor 122 if one is present, and the vehicle parasitic loads 124 , by means of a power distribution network 125 .
[0031] Other permutations of the invention are possible without departing from the teachings disclosed herein, provided that the function of the invention is to generate usable electrical power by extracting wind energy from an area of recirculation between the segments of a moving vehicle, or from an area of recirculation within the wake of a moving vehicle. Other advantages to a vehicle equipped with a wind turbine driven generator within an area of recirculation may also be inherent in the invention, without having been described above.
|
A vehicle having one or more small vehicle-mounted electricity generating wind turbines located within an area of wind recirculation. The electricity generated is used to recharge vehicle batteries, partially power an auxiliary electric propulsion motor, or supply vehicle parasitic loads.
| 5
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. § 119(a) of Korean Patent Application No. 2005-59218, filed on Jul. 1, 2005, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a dual-lens assembly having two independent lens modules for photographing moving images and still images, and an image photographing apparatus having the same.
[0004] 2. Description of the Related Art
[0005] In general, a DSC (Digital Still Camera) converts an image that enters through a lens into a digital signal, and stores it in a recording medium such as a hard disk or a memory card. The photographed image is then stored in the recording medium, not on photographic film, and can be entered directly to a computer. Since a digital still camera is fully compatible with a computer, anyone with a personal computer can easily edit and modify a digital image (that is, a photograph). Also, the photographed image may be transmitted to an external computer system. However, due to the limited capacity of the recording medium, digital still cameras are mainly used for photographing still images. Although some digital still cameras are capable of recording moving images, their recording time is insufficient. Normally, recording moving (or video) images requires two separate processes: one for recording video images and another for recording and reproducing audio for the video images. Therefore, realistically, a digital still camera is inadequate for recording and reproducing video images with sound. For this reason, people prefer a camcorder, which is capable of recording or reproducing both video images of a subject being photographed and audio onto or from a recording medium such as a tape.
[0006] Typically, a camcorder uses a cassette tape as its recording medium. The cassette tape is mounted in a deck for video recording. Also, a camcorder is typically provided with a microphone and a speaker. The camcorder, like the digital still camera, is capable of photographing a still image, but its picture quality is typically not as good as that of a digital still camera. Thus, the camcorder is used mostly for recording video images. Because a camcorder has more functions and thus a more complicated construction than a digital still camera, a typical camcorder is larger and more expensive than a digital still camera.
[0007] Until recently, when people wanted to take advantage of both digital still cameras and camcorders, they had to purchase two separate products. This was a financial burden on users, and was also inconvenient because a user had to carry two separate products. To resolve this problem, there have been efforts to devise an apparatus for photographing a still image and recording a video image, that is, having functions of both a digital still camera and a camcorder built into a single product, so that a user can selectively choose which one to use according to the circumstances. A “dual cam” has been developed and sold as one such product.
[0008] A dual cam has two lens modules with a different number of pixels. For instance, a lens module with a relatively higher number of pixels may be used for photographing a still image, whereas a lens module with a relatively lower number of pixels may be used for recording video images. Dual cam image photographing apparatuses capable of storing still images and moving (video) images photographed by each lens module in a medium such as a hard disk or a memory are now being actively developed.
[0009] In the dual cam, however, incorporating two products into a single product has caused problems such as an increased product size and a more complicated structure. Therefore, recent research has focused on developing an image photographing apparatus having a simpler structure and a small size. Furthermore, research continues on improving manufacturing productivity.
[0010] Accordingly, there is a need for a simpler, more compact image photographing apparatus capable of photographing both still images and moving (video) images.
SUMMARY OF THE INVENTION
[0011] An aspect of the present invention is to address at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a dual-lens assembly with an improved structure featuring a simple and easy arrangement of a plurality of lens modules, and an image photographing apparatus having the same.
[0012] To achieve the above objects and advantages, a dual-lens assembly comprises a board performing a predetermined function in an image photographing apparatus, a first lens unit joined with the board, and a second lens unit joined with the board. The second lens unit is oriented so that it obtains an image in the same direction as the first lens unit.
[0013] The first and second lens units may be arranged so that a virtual reference line connecting an optical axis passing through each of the lens units crosses a plane of the board.
[0014] The reference line and the plane of the board may form an angle of about 40° to 50° with respect to one another.
[0015] In an exemplary embodiment, the first lens unit may comprise a first lens module for photographing high quality picture images, a lens holder for encompassing the first lens module, and a first support bracket attached to the board for supporting the lens holder and the first lens module.
[0016] In an exemplary embodiment, the second lens unit may comprise a second lens module for obtaining moving picture quality images and a second support bracket for supporting the second lens module to the board and the first lens unit.
[0017] The second support bracket may comprise a first locking hole through which a screw is inserted into the second lens module, a second locking hole through which a screw is inserted into the lens holder, and a third locking hole through which a screw is inserted into the board.
[0018] The first lens unit may be installed at a lower position than the second lens unit.
[0019] The first lens unit may be arranged in a manner that the optical axis of the first lens unit is separated from the plane of the board.
[0020] The optical axes of the first and second lens units may be separated from each other.
[0021] The first and second lens units may be installed on opposite sides of the board and may be vertically offset with respect to one another.
[0022] In accordance with another exemplary embodiment of the present invention, an image photographing apparatus comprises a main body, a board performing a predetermined function disposed in the main body, a first lens unit joined with the board, and a second lens unit joined with the board. The second lens unit is oriented so that it obtains an image in the same direction as the first lens unit.
[0023] In accordance with still another exemplary embodiment of the present invention, an image photographing apparatus comprises a main body. A board is disposed in the main body, and the board has a plurality of electronic components for processing image data. A first lens unit is mounted on the board and has a first optical axis. The first lens unit obtains image data of a first quality and provides the image data to the plurality of electronic components. A second lens unit is mounted on the board and has a second optical axis. The second lens unit obtains image data of a second quality and provides the image data to the plurality of electronic components. The first and second optical axes are generally aligned so that the first and second lens units obtain images from the same direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The above and other objects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
[0025] FIG. 1 is a schematic front view of an image photographing apparatus according to an exemplary embodiment of the present invention;
[0026] FIG. 2 is an exploded perspective view of the dual-lens assembly shown in FIG. 1 ;
[0027] FIG. 3 is a perspective view of the first lens unit of FIG. 2 , assembled;
[0028] FIG. 4 is a perspective view of the second lens unit of FIG. 2 , assembled;
[0029] FIG. 5 is a perspective view of the second lens unit joined with a board; and
[0030] FIG. 6 is a perspective view of a dual-lens assembly (a first and a second lens unit) joined with a board.
[0031] Throughout the drawings, the same reference numerals will be understood to refer to the same elements, features, and structures.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0032] The matters defined in the description such as a detailed construction and elements are provided to assist in a comprehensive understanding of the embodiments of the invention. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
[0033] Referring to FIGS. 1 and 2 , an image photographing apparatus according to an exemplary embodiment of the present invention includes an image photographing apparatus main body 10 , and a dual-lens assembly 100 installed in the main body 10 . The dual-lens assembly 100 includes a board 20 , and first and second lens units 30 , 40 joined with the board 20 .
[0034] A data storage medium (not shown) is installed in the main body 10 . Images (or image data) provided by each lens unit 30 , 40 are stored in the storage medium. Also, a display panel 11 for displaying an image that enters through each lens unit 30 , 40 is attached in an openable and closable manner to the outside of the main body 10 .
[0035] The board 20 is electrically connected to both of the first and second lens units 30 , 40 and controls the operation of each lens unit 30 , 40 and processes photographed image data provided by the lens units 30 , 40 . The board 20 has a substantially planar shape and is installed in the main body 10 in such a manner that its plane 21 stands basically upright. A plurality of electronic components are installed on the board 20 . Connectors 22 , 23 , 24 are provided on the board 20 and are connected to the first and second lens units 30 , 40 and other functional components through a cable.
[0036] In an exemplary embodiment, the first lens unit 30 is a digital still camera lens (DSC-lens) which may be used for photographing a still image. In particular, the first lens unit may be used for taking a high picture quality image by employing a CCD having a high number of pixels. The first lens unit 30 includes a first lens module 31 , a lens holder 33 for encompassing and supporting the lens module 31 , and a first support bracket 35 for attaching the lens holder 33 and the first lens module 31 to the board 20 .
[0037] The first lens module 31 has a cylindrical shaped housing 31 a in which a lens is installed. The lens holder 33 is fit into the outside of the housing 31 a from the front side of the first lens module 31 . Meanwhile, the rear side of the first lens module 31 is combined to a CCD (Charge-Coupled Device) (not shown) and a CCD board. Moreover, on the rear side of the first lens module 31 there is a coupling part 31 b having a locking hole 31 c into which a screw is inserted. This coupling part 31 b may be combined with the housing 31 a as one unit, or screwed into the housing 31 a as a separate component. Also, a drive motor 34 for driving the internal lens is installed at the outside of the first lens module 31 .
[0038] The lens holder 33 has a pipe-shaped body 33 a for encompassing the outside of the housing 31 a , and a first and a second screw coupling part 33 b , 33 c combined as one unit on the outside of the body 33 a . The first screw locking part 33 b is formed to correspond to a locking hole 31 c of the coupling part 31 b . Therefore, the first support bracket 35 and a screw 36 passing through the locking hole 31 c are locked to a first screw coupling part 33 b , so that the first lens module 31 , the lens holder 33 and the first support bracket 35 may be locked together.
[0039] The first support bracket 35 has a plurality of first screw holes 35 a formed to correspond to the locking holes 31 c for the screws 36 . Screws 37 pass through a plurality of second screw holes 35 b to lock the first support bracket 35 to the board 20 . The portion of the first supporting bracket 35 where the second screw holes 35 are formed is bent so that it is substantially parallel with the board 20 . The first support bracket 35 is preferably made of metal.
[0040] The first lens unit 30 having the above configuration is arranged so that an optical axis x 1 passing through the lens is spaced a distance away from the plane 21 of the board 20 . In the illustrated, exemplary embodiment of the present invention, the first lens unit 30 is located on the left side of the board 20 when seen from the front of the body 10 (that is, from the direction of a subject being photographed).
[0041] The second lens unit 40 includes a second lens module 41 , and a second support bracket 43 for supporting the second lens module 41 to the board 20 and the first lens unit 30 .
[0042] The second lens module 41 is used mainly for photographing moving images. That is, the second lens module produces images with a smaller number of pixels, yielding a poorer picture quality that that of the first lens module 31 . A lens 41 b is installed in front of a housing 41 a , and another lens (not shown) is installed inside the housing 41 a.
[0043] A locking boss 41 c where a screw 45 is inserted is formed on one side of the housing 41 a , and a CCD board 44 for driving a CCD 42 is attached to the rear side of the housing 41 a . The CCD board 44 is provided with a connector 44 a which joins the connector 22 on the board 20 .
[0044] The second support bracket 43 has an “L” shape. In detail, it has a horizontal portion 43 a and a vertical portion 43 b . The top end of the vertical portion 43 b has a first locking hole H 1 through which a screw 45 is inserted into the locking boss 41 c of the second lens module 41 . The horizontal portion 43 a has a second locking hole H 2 through which a screw 46 is inserted into the board 20 , and a third locking hole H 3 through which a screw 48 is inserted into the second screw coupling part 33 c of the lens holder 33 . In this manner, the second support bracket 43 combines with the second lens module 41 , the lens holder 33 and the board 20 , which in turn makes the first and second lens units 30 , 40 firmly fastened to the board 20 .
[0045] The second lens unit 40 having the above configuration is arranged in such a manner that an optical axis x 2 passing through the lens is spaced away from the plane 21 of the board 20 as well as the optical axis X 1 . In detail, the second lens unit 40 is located on the right side of the board 20 , on the opposite side of the board 20 than the first lens unit 30 . The second lens unit 40 is located above the first lens unit 30 . More specifically, the lens units 30 , 40 are arranged so that a virtual reference line L 1 connecting the two axes X 1 and X 2 cross the plane 21 of the board 20 , that is, a reference plane A parallel to the plane 21 (see FIG. 1 ), at a predetermined angle. In an exemplary embodiment, an angle θ between the reference line L and the reference plane A ranges from approximately 40° to 50°. The illustrated embodiment has an angle of approximately 45°.
[0046] By installing the second lens unit 40 above the first lens unit 30 so that there is about a 45° angle between the reference line L and the reference plane A, the total width in a parallel direction of the reference plane A can be reduced. In other words, the image photographing apparatus can be manufactured in a smaller size. By the nature of the apparatus, the main body 10 tends to be cube-shaped. If the first and second lens units 30 , 40 are arranged to at the corners of the main body 10 as in the exemplary embodiments of the invention, both the horizontal and vertical sizes of the main body 10 can be minimized while using the interior space of the main body 10 more efficiently.
[0047] A method of assembling the image photographing apparatus according to an exemplary embodiment of the present invention will now be described. Initially, one of the first and second lens units 30 , 40 is assembled. If the first lens unit 30 is assembled first, the lens holder 33 is inserted into the first lens module 31 . Then, the lens holder 33 , the first lens module 31 , and the first support bracket 35 (here, the first support bracket 35 is placed behind the first lens module 31 ) are combined with the screws 36 . In this manner, the assembly of the first lens unit 30 is finished as depicted in FIG. 3 . Of course, before assembling the first support bracket 35 , the coupling part 31 b and the CCD (not shown) are assembled behind the first lens module 31 .
[0048] Next, the second lens unit 40 , the CCD 42 and the CCD board 44 are sequentially assembled to the second lens module 41 . Then, the second support bracket 43 is linked to the second lens module 41 using the screw 45 . In this manner, the assembly of the second lens unit 40 is finished as shown in FIG. 4 .
[0049] The completely assembled second lens unit 40 is joined with the board 20 by the screw 46 . That is, the screw 46 is inserted into the second locking hole H 2 of the second support bracket 43 to fasten the second lens unit 40 to the board 20 . The connector 44 a of the CCD board 44 is joined with the connecter 22 of the board 20 . In this manner, the assembly of the second lens unit 40 to the board 20 is finished as illustrated in FIG. 5 .
[0050] The completely assembled first lens unit 30 is then joined with the board 20 . In detail, the screw 37 is inserted into the second screw hole 35 b of the first support bracket 35 to fasten the first lens unit 30 to the board 20 . In this manner, the assembly of the first lens unit 30 to the board 20 is finished as illustrated in FIG. 6 .
[0051] In this state, the second support bracket 43 is joined with the lens holder 33 using the screw 48 to complete the assembly work of the dual-lens assembly 100 .
[0052] Finally, the board 40 and the lens units 30 , 40 are connected through a signal cable, so that signals and power can be transferred to each other.
[0053] According to the exemplary embodiment of the dual-lens assembly and the image photographing apparatus of the present invention, the overall size of the set and the interior space of the apparatus can be reduced by arranging two lens units in an oblique direction crossing the reference plane of the board at an angle.
[0054] Moreover, since the first and second lens units are all assembled to one board, the total number of components used can be reduced and the assembly time can be shortened. Accordingly, manufacturing productivity is enhanced and manufacturing costs can be reduced.
[0055] While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
|
A dual-lens assembly for an image photographing apparatus includes a board that performs a predetermined function in an image photographing apparatus. A first lens unit is joined with the board, and a second lens unit is joined with the board. The first and second lens units are oriented so that they obtain images in the same direction.
| 7
|
REFERENCE TO RELATED APPLICATION
This application is a division of U.S. patent application Ser. No. 09/472,480, filed on Dec. 27, 1999, now U.S. Pat. No. 6,504,684 and entitled “Head Suspension With Integral Shock Limiter.”
FIELD OF THE INVENTION
The present invention is directed to a head suspension for supporting a head slider relative to a rotating disk in a rigid disk drive, and in particular, to a head suspension having a shock limiter integrally formed in the load beam.
BACKGROUND OF THE INVENTION
In a dynamic rigid disk storage device, a rotating disk is employed to store information. Rigid disk storage devices typically include a frame to provide attachment points and orientation for other components, and a spindle motor mounted to the frame for rotating the disk. A read/write head is formed on a “head slider” for writing and reading data to and from the disk surface. The head slider is supported and properly oriented in relationship to the disk by a head suspension that provides both the force and compliance necessary for proper head slider operation. As the disk in the storage device rotates beneath the head slider and head suspension, the air above the disk also rotates, thus creating an air bearing which acts with an aerodynamic design of the head slider to create a lift force on the head slider. The lift force is counteracted by a spring force of the head suspension, thus positioning the head slider at a desired height and alignment above the disk which is referred to as the “fly height.”
Head suspensions for rigid disk drives include a load beam and a flexure. The load beam includes a mounting region at its proximal end for mounting the head suspension to an actuator of the disk drive, a rigid region, and a spring region between the mounting region and the rigid region for providing a spring force to counteract the aerodynamic lift force generated on the head slider during the drive operation as described above. The flexure typically includes a gimbal region having a slider mounting surface where the head slider is mounted. The gimbal region is resiliently moveable with respect to the remainder of the flexure in response to the aerodynamic forces generated by the air bearing. The gimbal region permits the head slider to move in pitch and roll directions and to follow disk surface fluctuations.
In one type of head suspension the flexure is formed as a separate piece having a load beam mounting region which is rigidly mounted to the distal end of the load beam using conventional methods such as spot welds. Head suspensions of this type typically include a load point dimple formed in either the load beam or the gimbal region of the flexure. The load point dimple transfers portions of the load generated by the spring region of the load beam to the flexure, provides clearance between the flexure and the load beam, and serves as a point about which the head slider can gimbal in pitch and roll directions to follow fluctuations in the disk surface.
As disk drives are designed having smaller disks, closer spacing, and increased storage densities, smaller and thinner head suspensions are required. These smaller and thinner head suspensions are susceptible to damage if the disk drive is subjected to a shock load or if the suspension experiences excessive pitch and roll motion. Moreover, as the use of portable personal computers increases, it is more likely that head suspensions in these portable computers will be subjected to shock loads. Thus, it is becoming increasingly important to design the head suspension so that it is less susceptible to excessive movements caused by shock loads and by pitch and roll motion, while still maintaining the necessary freedom of movement in the pitch and roll directions. In this manner, damaging contact between the head slider and the disk surface and permanent deformation of components of the head suspension can be prevented.
Mechanisms have been developed for limiting the movement of a free end of a cantilever portion of a flexure for protection against damage under shock loads. One such mechanism is disclosed in U.S. Pat. No. 4,724,500 to Dalziel. The Dalziel reference describes a limiter structure comprising a head slider having raised shoulders to which one or more elements are secured. The elements on the head slider overlap at least a portion of a top surface of the load beam to which the flexure is attached.
Another motion limiter is disclosed in U.S. Pat. No. 5,333,085 to Prentice et al. The head suspension shown in Prentice includes a tab that extends from a free end of a cantilever portion of a flexure. The tab is fitted through an opening of the load beam to oppose the top surface of the load beam.
Another motion limiter is disclosed in U.S. Pat. No. 5,526,205 to Aoyagi et al. The Aoyagi reference discloses a head suspension having a perpendicular hook at an end of a flexure. The hook is shaped to engage a transverse appendage at the distal end of a load beam to prevent the end of the flexure from displacing vertically too great a distance from the load beam.
Yet another motion limiter is disclosed in U.S. Pat. No. 5,877,920 to Resh. The Resh reference discloses a head suspension assembly including a load beam, a recording head and a gimbal including a head mounting tab on which the recording head is mounted. A displacement limiter extends between the load beam and the gimbal for limiting vertical displacement of the gimbal in a direction toward the recording head relative to the load beam.
Additionally, mechanisms have been developed for limiting motion of the overall load beam relative to the disk. One such mechanism is shown in Japanese Patent No. 11-66766 to Kawazoe. The Kawazoe patent teaches a hard disk drive having a suspension including a lift prevention member formed in or attached to the mounting region of the load beam that prevents lifting of the flying head away from the hard disk due to an impact load. Another mechanism is shown in U.S. Pat. No. 5,808,837 to Norton. The Norton patent teaches a hard disk drive having a suspension arm and a separate limit stop to restrain movement of the suspension arm that is mounted adjacent the suspension arm. Other mechanisms for restraining suspension movement are shown in U.S. Pat. No. 5,936,804 to Riener et al., U.S. Pat. No. 5,926,347 to Kouhei et al., and U.S. Pat. No. 5,831,793 to Resh.
A need still exists, however, for an improved head suspension including a mechanism capable of limiting motion of the suspension away from the surface of the disk due to impact and shock loading. Such a mechanism should work within the requirements of hard disk drive suspensions, including overall weight limitations, height limitations, manufacturability and functionality.
SUMMARY OF THE INVENTION
The present invention meets the ongoing need for improved head suspensions by providing a head suspension that includes an integral shock limiter. The head suspension is typically formed from a flexure and a load beam that has a mounting region, a rigid region and a spring region located between the mounting and rigid regions. The load beam includes a shock limiter integrally formed within the spring region as a cantilevered portion surrounded by a spring aperture used for adjusting the spring stiffness of the spring region. The cantilevered portion is configured to overlap a portion of the head suspension, such as the flexure, a portion of the load beam or a base plate mounted to the load beam at the mounting region.
A bend or radius is typically formed into the spring region in order to bias the head suspension toward the disk surface. A cantilevered portion of the shock limiter is formed to allow for a pre-determined gap between the shock limiter and the overlapped portion of the head suspension, when the suspension is held in its operating position. This gap allows for slight movement vertically before the shock limiter is engaged. Upon movement of the head suspension away from the disk surface due to an impact load, the head suspension flexes about the spring region and the rigid region of the load beam moves away from the disk surface. As the head suspension moves farther away from the disk surface, the cantilevered portion contacts the overlapped portion of the head suspension, thereby arresting the movement of the head suspension and limiting damage to the disk drive. The cantilevered portion may be reconfigured by bending to achieve the overlap with the overlapped portion of the head suspension.
The present invention provides a head suspension including a shock limiter integrally formed in the spring region of the load beam for limiting movement of the head suspension away from the surface of the disk over which the head suspension is suspended. Use of such an integral shock limiter provides the advantage of simultaneous formation with a spring aperture used to adjust the stiffness of the spring region. In addition, such a shock limiter allows for minimization of weight and manufacturing steps by utilizing material and processes already present in the fabrication of the head suspension. Yet another benefit of the shock limiter of the present invention is the ability to minimize load loss due to back bending of the spring region radius formed to provide gram loading at the head slider to counteract aerodynamic lifting forces on the head slider. These numerous benefits, along with the function of the shock limiter, set the present invention apart as a significant improvement in head suspension design.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 a top plan view of a hard disk drive including a head suspension assembly.
FIG. 2 is an exploded perspective view of the head suspension assembly of FIG. 1 , including one embodiment of an integral shock limiter in accordance with the present invention.
FIG. 3 is a top plan view of the head suspension shown in FIG. 2 .
FIG. 4 is a top plan view of a head suspension including another embodiment of an integral shock limiter in accordance with the present invention.
FIG. 5 is a perspective view of the head suspension of FIG. 4 after reconfiguration of the integral shock limiter.
FIG. 6 is a cross-sectional side view of the d suspension of FIG. 5 , taken along Line 6 — 6 .
FIG. 7 is a top plan view of a head suspension including yet another embodiment of an integral shock limiter in accordance with the present invention.
FIG. 8 is a perspective view of the head suspension of FIG. 7 after reconfiguration of the integral shock limiter.
FIG. 9 is a cross-sectional side view of the head suspension of FIG. 8 , taken along Line 9 — 9 .
FIG. 10 is an exploded perspective view of a head suspension assembly, including another embodiment of a shock limiter in accordance with the present invention.
FIG. 11 is a top plan view of the head suspension shown in FIG. 10 .
FIG. 12 is a cross-sectional side view of a portion of the head suspension of FIG. 11 , taken along Line 12 — 12 .
FIG. 13 is an exploded perspective view of a head suspension assembly, including yet another embodiment of a shock limiter in accordance with the present invention.
FIG. 14 is a top plan view of the head suspension shown in FIG. 13 .
FIG. 15 is a cross-sectional side view of a portion of the head suspension of FIG. 14 , taken along Line 15 — 15 .
DETAILED DESCRIPTION OF THE INVENTION
With reference to the attached Figures, it is to be understood that like components are labeled with like numerals throughout the several Figures. FIG. 1 schematically illustrates a rigid disk drive 12 that includes a head suspension assembly 8 . Head suspension assembly 8 resiliently supports a head slider 14 at a fly height above a rigid disk 16 during operation, as described above in the Background section. Head suspension assembly 8 is connected to a rotary actuator 18 , as is known, for accessing data tracks provided on the surface of rigid disk 16 . Head suspension assembly 8 could otherwise be utilized with a linear type actuator, as is also well known.
FIG. 2 shows head suspension assembly 8 in greater detail. Head suspension assembly 8 includes head suspension 10 in accordance with the present invention, slider 14 , and a base plate 22 . Head suspension 10 includes a load beam 20 and a flexure 30 . Base plate 22 can be conventionally fixed to an actuator mounting region 24 located at the proximal end 23 of the load beam 20 , such as by welding. The load beam 20 has a rigid region 28 , and a spring region 26 between the mounting region 24 and rigid region 28 . The spring region 26 typically includes a bend or radius 50 , and provides a load to the rigid region 28 with respect to mounting region 24 . Rigid region 28 is provided with stiffening rails 32 , as are well known, to enhance stiffness properties.
In the embodiment shown in FIGS. 2 and 3 , the flexure 30 extends from the distal end 21 of load beam 20 , is constructed as a separate element of head suspension 10 , and is co-extensive with the rigid region 28 of the load beam 20 . Flexure 30 comprises a load beam mounting region 37 and a gimbal region 38 and is generally co-planar to the load beam 20 . The flexure 30 is secured to load beam 20 in a conventional manner, such as by welding load beam mounting region 37 to the rigid region 28 of the load beam 20 .
Rigid region 28 of load beam 20 includes a load portion 36 at its distal end 21 . Included in the load portion 36 is a load point 40 for transferring the load from load portion 36 to the gimbal region 38 of the flexure 30 . The load point 40 may be formed extending from the load portion 36 of the load beam 20 toward gimbal region 38 , or the load point 40 can be formed in gimbal region 38 to extend toward load portion 36 of load beam 20 . The load point 40 may be formed as a dimple, using conventional methods such as a forming punch. Alternately, the load point 40 may be formed by other structure, including an etched tower, a glass ball, or an epoxy dome.
The spring region 26 of the load beam 20 provides a spring force load to the slider 14 through the flexure 30 at the distal end 21 of the load beam 20 . This is typically accomplished through the pre-formed bend or radius 50 that is formed in a rotational direction for functionally biasing the slider 14 toward the surface of the disk 16 when the disk drive 12 is in use. The degree of the bend or radius 50 is determined by both the predetermined offset height of the slider 14 over the non-moving disk 16 , and the gram load needed to counteract the aerodynamic lift force generated on the slider 14 when the slider 14 flies over the moving disk 16 and to produce a desired fly height of the slider 14 over the moving disk 16 .
The spring region 26 may also include a spring aperture 60 used to adjust or tune spring characteristics (such as stiffness) of the spring region 26 , and thus the gram loading, by removal of spring region material. Such adjustment of the spring stiffness has the added benefit of reducing the overall weight of the head suspension 10 .
The spring region 26 is thus designed to provide a desired force toward the disk 16 to counteract a resulting aerodynamic lift force away from the disk 16 . However, when the disk drive 12 is subjected to shock or impact loads, such as those due to dropping of the drive 12 or other impact, the head suspension 10 may react by moving abruptly toward or away from the disk 16 . Such movement may cause the head slider 14 to crash into the disk 16 , and/or crash against other components within the disk drive 12 . Either type of head slider contact may damage the head slider 14 and/or the disk drive 12 . In addition, excessive movement of the head suspension 10 away from the disk 16 , and thus in the opposite direction of the bend or radius 50 , may cause permanent deformation of the bend or radius 50 , thereby changing the gram loading associated with the bend or radius 50 and affecting the function of the drive 12 . Such a change in the gram loading is typically known as “load loss.”
In order to help prevent catastrophic contact of the head slider 14 due to impact loads, as well as prevent load loss, a shock limiter 70 is integrally formed within the spring region 26 , in accordance with the present invention. In the embodiment shown in FIGS. 2 and 3 , the shock limiter 70 is formed from the spring region material as an elongated cantilevered portion extending from a proximal edge 62 of the spring aperture 60 . The shock limiter 70 connects to the spring region material at a proximal end 72 and extends toward the distal end 21 of the load beam 20 at a distal end 74 . As shown in FIG. 3 , the distal end 74 of the shock limiter 70 overlaps a proximal end 35 of the flexure 30 .
The spring aperture 60 is formed around the shock limiter 70 in a generally ‘U’ shaped configuration. Since the spring aperture 60 is responsible for adjustment of the spring stiffness in the spring region 26 , the size and shape of the spring aperture 60 around the shock limiter 70 may vary according to the spring force requirements of a particular head suspension 10 . In the embodiment shown in FIG. 3 , the spring aperture 60 includes a pair of larger openings 64 flanking the proximal end 72 of the shock limiter 70 . The spring aperture 60 also includes an elongated portion 66 formed as a generally uniform gap around the sides and distal end 74 of the shock limiter 70 , overlapping a portion of the proximal end 35 of the flexure 30 , as well.
As shown in FIG. 2 , the bend or radius 50 is formed in the spring region 26 . The shock limiter 70 is formed to include a pre-determined gap between the distal end 74 of the shock limiter 70 and the rigid region 28 of the load beam 20 , when the head suspension 10 is in an operating position. When a shock load causes the head suspension 10 to move away from the disk 16 , the head suspension 10 flexes about the spring region 26 and the rigid region 28 of the load beam 20 moves toward the shock limiter 70 . As the head suspension 10 moves farther away from the disk 16 , the overlapped portion 35 of the flexure 30 contacts the shock limiter 70 , thus arresting the movement of the head suspension 10 , thereby minimizing the effects of the shock load induced movement.
Integral formation of the shock limiter 70 within the spring region 26 results in both the spring aperture 60 and the shock limiter 70 being formed simultaneously, thus eliminating the need for additional manufacturing steps. Additionally, integral formation of the shock limiter 70 eliminates the need for additional material being mounted to the head suspension 10 in order to provide limitation of movement during a shock loading, thereby keeping the overall weight of the head suspension to a minimum.
Referring now to FIGS. 4–6 , in another embodiment of the present invention, a head suspension 110 is shown formed from a load beam 120 having a mounting region 124 , a rigid region 128 and a spring region 126 located between the mounting region 124 and rigid region 128 . Integrally formed within the spring region 126 is a shock limiter 170 surrounded by a spring aperture 160 . In this embodiment, the shock limiter 170 is also an elongated cantilevered portion connected to the spring region material at a proximal end 172 , but includes a transverse cross-piece 176 at a distal end 174 . The cross-piece 176 extends beyond the sides 177 , 178 of the shock limiter 170 , giving the limiter 170 a generally ‘T’ configuration.
The spring aperture 160 conforms in shape to the configuration of the shock limiter 170 . In this embodiment, the spring aperture 160 includes an elongated portion 166 and a transverse opening 168 at the distal end 167 of the elongated portion 166 , formed as a generally uniform gap around the perimeter of the shock limiter 170 . In addition, the spring aperture 160 also includes enlarged side openings 164 formed adjacent the proximal end 172 of the shock limiter 170 . As described above, the size and shape of the spring aperture 160 may vary according to the spring force stiffness requirements of the head suspension 110 .
In this embodiment, instead of utilizing a flexure (not shown) as the contact surface for the shock limiter 170 , two transverse tab portions 127 formed by the configuration of the spring aperture 160 serve as the contact surface. In order to accomplish this, the shock limiter 170 is reconfigured, preferably by bending, to overlap these two tab portions 127 . The shock limiter 170 is bent at form lines 181 , 182 and 183 (shown in phantom) to produce a ‘V’ notch 179 perpendicular to the plane of the head suspension 110 , best seen in FIG. 6 . The effect of the ‘V’ notch 179 is to shorten the shock limiter 170 , thus moving the cross-piece 176 over the two tab portions 127 . FIG. 5 shows the resulting configuration of the shock limiter 170 .
In the same manner as the embodiment described above, a bend or radius 150 is formed in the spring region 126 , and the shock limiter 170 is formed with a predetermined gap between the distal end 174 of the shock limiter 170 and the rigid region 128 of the load beam 120 . When shock or impact loading causes the head suspension 110 to move away from the disk 16 , the spring region 126 flexes and the rigid region 128 moves toward the shock limiter 170 . The two tab portions 127 then contact the shock limiter cross-piece 176 , arresting the movement of the head suspension 110 away from the disk 16 . The lateral spacing of the tab portions 127 provides additional stability to the head suspension 110 when subjected to torsional shock loads.
Referring now to FIGS. 7–9 , in yet another embodiment of the present invention, a head suspension 210 is shown formed from a load beam 220 having a mounting region 224 , a rigid region 228 and a spring region 226 located between the mounting region 224 and rigid region 228 . Integrally formed within the spring region 226 is a shock limiter 270 surrounded by a spring aperture 260 . In this embodiment, the shock limiter 270 is also an elongated cantilevered portion connected to the spring region material at a proximal end 272 , but includes a transverse ‘U’ shaped cross-piece 276 at a distal end 274 . The ‘U’ shaped cross-piece 276 extends beyond the sides 277 , 278 of the shock limiter 270 with two ‘L’ shaped fingers 273 and 275 , giving the limiter 270 a generally ‘Y’ configuration.
The spring aperture 260 also conforms in shape to the configuration of the shock limiter 270 . In this embodiment, the spring aperture 260 includes a rectangular portion 266 and a ‘U’ shaped transverse opening 268 at the distal end 267 of the rectangular portion 266 , formed as a generally uniform gap around the perimeter of the shock limiter 270 . In addition, the spring aperture 260 also includes enlarged side openings 264 formed adjacent the proximal end 272 of the shock limiter 270 . As described above, the size and shape of the spring aperture 260 may vary according to the spring force stiffness requirements of the head suspension 210 . As a result of the configuration of the spring aperture 260 , two side tabs 227 extend transversely into the spring aperture 260 and a distal tab 229 extends longitudinally into the spring aperture 260 .
In this embodiment, the contact surface for the shock limiter 270 is the distal tab 229 . In order to accomplish this, the shock limiter 270 is reconfigured, preferably by bending, to overlap this distal tab 229 . The two ‘L’ shaped fingers 273 , 275 are bent perpendicular to the shock limiter 270 away from the load beam 220 at form lines 280 , 281 (shown in phantom). As a result, the two fingers 273 , 275 overlap the distal tab 229 . FIG. 8 shows the resulting configuration of the shock limiter 270 .
In the same manner as the embodiments described above, a bend or radius 250 is formed in the spring region 226 , and the shock limiter 270 is formed with a predetermined gap between the distal end 274 of the shock limiter 270 and the rigid region 228 of the load beam 220 . When shock or impact loading causes the head suspension 210 to move away from the disk 16 , the spring region 226 flexes and the rigid region 228 moves toward the shock limiter 270 . The distal tab 229 then contacts the shock limiter fingers 273 , 275 , arresting the movement of the head suspension 210 away from the disk 16 .
Referring now to FIGS. 10–12 , in yet another embodiment of the present invention, a head suspension assembly 308 is shown. Head suspension assembly 308 includes head suspension 310 in accordance with the present invention, slider 314 , and a base plate 322 . Head suspension 310 includes a load beam 320 and a flexure 330 . Base plate 322 is shown mounting to an actuator mounting region 324 located at the proximal end 323 of the load beam 320 on the underside of the load beam 320 . The base plate 322 includes a proximal edge 380 and a distal edge 382 .
The load beam 320 is shown having a mounting region 324 , a rigid region 328 and a spring region 326 located between the mounting region 324 and rigid region 328 , as well as a spring aperture 360 formed within the spring region 326 . Integrally formed in the spring aperture 360 within the spring region 326 is a shock limiter 370 configured as an elongated cantilevered portion extending from a distal edge 363 of the spring aperture 360 . The shock limiter 370 connects to the spring region material at a distal end 374 and extends toward the proximal end 323 of the load beam 320 at a proximal end 372 . As shown in FIG. 11 , the proximal end 372 of the shock limiter 370 overlaps the distal edge 382 of the base plate 322 .
The spring aperture 360 is formed around the shock limiter 370 in a generally ‘U’ shaped configuration. Since the spring aperture 360 is responsible for adjustment of the spring stiffness in the spring region 326 , the size and shape of the spring aperture 360 around the shock limiter 370 may vary according to the spring force requirements of a particular head suspension 310 . In the embodiment shown in FIGS. 10 and 11 , the spring aperture 360 includes a pair of larger openings 364 flanking the distal end 374 of the shock limiter 370 . The spring aperture 360 also includes an elongated portion 366 formed as a generally uniform gap around the sides and proximal end 372 of the shock limiter 370 , overlapping a portion of the distal end 382 of the base plate 322 , as well.
As shown in FIGS. 10 and 12 , in a manner similar to the embodiments described above, a bend or radius 350 is formed in the spring region 326 . The shock limiter 370 is configured to include a pre-determined gap between the proximal end 372 of the shock limiter 370 and the mounting region 324 of the load beam 320 , when the head suspension 310 is in an operating position. When a shock load causes the head suspension 310 to move away from the disk 16 , the head suspension 310 flexes about the spring region 326 and the rigid region 328 of the load beam 320 also moves away from disk 16 resulting in the shock limiter 370 moving toward the mounting region 324 . As the head suspension 310 moves farther away from the disk 16 , the overlapped distal edge 382 of the base plate 322 contacts the shock limiter 370 , thus arresting the movement of the head suspension 310 , thereby minimizing the effects of the shock load induced movement.
Referring now to FIGS. 13–15 , in yet another embodiment of the present invention, a head suspension 410 is shown formed from a load beam 420 having a mounting region 424 , a rigid region 428 and a spring region 426 located between the mounting region 424 and rigid region 428 . Integrally formed within the spring region 426 is a shock limiter 470 surrounded by a spring aperture 460 . In this embodiment, the shock limiter 470 is also an elongated cantilevered portion connected to the spring region material at a distal end 474 .
The spring aperture 460 conforms in shape to the configuration of the shock limiter 470 . The spring aperture 460 includes an elongated portion 466 formed as a generally uniform gap around the perimeter of the shock limiter 470 and enlarged side openings 464 formed adjacent the distal end 474 of the shock limiter 470 . As described above, the size and shape of the spring aperture 460 may vary according to the spring force stiffness requirements of the head suspension 410 .
In this embodiment, instead of mounting a base plate 422 to the mounting region 424 of the load beam 420 on the underside, the base plate 422 is mounted in a similar manner to the topside of the load beam 420 , as shown in FIG. 13 . In order utilize the base plate 422 as the contact surface for the shock limiter 470 , the shock limiter 470 is reconfigured, preferably by bending, to overlap the distal edge 482 of the base plate 422 . The shock limiter 470 is bent at form lines 485 and 486 (shown in phantom in FIG. 14 ) to produce an offset 479 transverse to the plane of the head suspension 410 , best seen in FIG. 15 . The effect of the offset 479 is to lift the shock limiter 470 above the base plate 422 . FIG. 13 shows the resulting configuration of the shock limiter 470 .
In the same manner as the embodiments described above, a bend or radius 450 is formed in the spring region 426 , and the shock limiter 470 is formed with a predetermined gap between the proximal end 472 of the shock limiter 470 and the base plate 422 . When shock or impact loading causes the head suspension 410 to move away from the disk 16 , the spring region 426 flexes and the rigid region 428 also moves away from disk 16 resulting in movement of the shock limiter 470 toward the mounting region 424 . The proximal end 472 of the shock limiter 470 then contacts the base plate 422 , arresting the movement of the head suspension 410 away from the disk 16 .
As would be apparent to one skilled in the art, other suitable integral shock limiters may be formed within the spring region of the load beam and other portions of the head suspension used as contact surfaces to achieve the same results as those embodiments described above. It is to be understood that such shock limiters are within the spirit and scope of the present invention.
A shock limiter, as described in the embodiments above, may be formed from the spring region of the load beam using fabrication methods generally known in the art. These fabrication methods include, but are not limited to, etching, stamping, and machining. Since the shock limiter may be formed simultaneously with the spring aperture, the same fabrication methods used for the spring aperture may also be used for the shock limiter.
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. In addition, the invention is not to be taken as limited to all of the details thereof as modifications and variations thereof may be made without departing from the spirit or scope of the invention.
|
A method of limiting movement of a head suspension away from a disk surface, the head suspension used for supporting a head slider over the disk surface in a rigid disk drive, the method comprising the steps of providing a load beam for use in a head suspension, the load beam having a mounting region, a rigid region and a spring region located between the mounting region and rigid region; forming a shock limiter from the same piece of material as the spring region of the load beam, the shock limiter comprising a cantilevered portion overlapping an overlapped portion of the head suspension; forming a head suspension from the load beam; and mounting the head suspension in a bard disk drive suspending a head slider over the surface of the disk, such that when an impact load causes the head suspension to move away from the surface of the disk, the shock limiter limits such movement
| 8
|
RELATED APPLICATIONS
The present application is related to commonly assigned, copending patent applications for MOLDED CONTROL PANEL FOR OUTBOARD MOTOR, Ser. No. 07/525,594, filed May 18, 1990, for MOLDED LOWER MOTOR COVER, Ser. No. 07/525,595, filed May 18, 1990, and for MARINE PROPULSION DEVICE COWL ASSEMBLY, Ser. No. 07/526,499, filed May 18, 1990.
BACKGROUND OF THE INVENTION
The present invention relates to outboard marine motors having upper and lower motor covers, and more specifically to a motor cover seal for sealing opposed edges of the upper and lower motor covers against the intrusion of moisture.
An outboard marine motor generally includes an engine portion and a depending gear case. The engine portion of the outboard motor is typically enclosed by upper and lower motor covers which may be collectively referred to as the cowl assembly.
A disadvantage of conventional marine motor cowls relates to the necessity of maintaining a watertight seal between interfacing opposed edges of the upper and lower motor covers. In conventional outboard motor cowls, a continuous looped sealing member is either glued or stitched to either one or both opposing edges of the upper and lower motor covers. Thus, when the cowl is closed, the entry of water into the cowl is prevented. Through use and/or exposure to the elements, the glue or stitching deteriorates, and the seal may become detached from the cover. This deterioration of the seal decreases its water repelling efficiency, and when replacement is required, the fastening of a replacement seal is often a laborious procedure.
Another disadvantage of conventional marine motors is that the lower motor covers of conventional cowl assemblies are fabricated of die cast aluminum, and, as such, require significant machining to complete the manufacturing process of each cover. Consequently, manufacturing costs for producing lower motor covers of die cast aluminum are relatively high. In addition, die cast lower motor covers restrict the available design configurations of such covers, and thus impede motor cowl styling. Furthermore, conventional aluminum die cast lower motor covers require supplemental mounting hardware to enable the attachment of the cover to the motor.
Still another disadvantage of conventional motor cowls relates to the necessity of removing the lower motor cover when maintenance is performed on the engine. In conventional cowls, the motor control systems such as choke, fuel connector, throttle cable and/or remote control cables must also be removed during disassembly of the lower motor covers. This requirement results in excessively costly and time consuming maintenance procedures.
Thus, there is a need for an outboard motor cowl including a positively attached, yet readily replaceable seal for the opposing edges of the upper and lower motor covers. There is also a need for an outboard motor cowl including an easily manufactured and assembled lower motor cover which may be styled in a wide variety of exterior configurations without requiring excessive mounting hardware. In addition, there is a need for a marine motor cowl in which the control systems are accessible without requiring disassembly of the lower motor cover.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a motor cover seal which may be positively attached to the lower motor cover without the use of adhesives or stitching, and, as such is readily replaceable. More specifically, the present motor cover seal includes an elongate body constructed and arranged for disposition between the corresponding opposed edges of the upper and lower covers, an attachment portion on the body configured to be secured to the lower motor cover, and a compressible portion on the body configured to be compressed by the closing of the upper motor cover against the lower motor cover.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of an outboard marine motor of the type in which the present motor cover seal may be employed;
FIG. 2 is a front elevational view of the motor of FIG. 1, taken generally along the line 2--2 of FIG. 1 and in the direction indicated generally, with certain parts removed for clarity;
FIG. 3 is a fragmentary sectional view taken generally along line 3--3 of FIG. 1 and in the direction indicated generally;
FIG. 4 is an exploded front perspective elevational view of the marine outboard motor of FIG. 1;
FIG. 5 is a fragmentary rear exploded view of a latch portion of the motor of FIG. 4;
FIG. 6 is a fragmentary vertical sectional view of the latch portion depicted in FIG. 5, shown in the closed position:
FIG. 7 is a side elevational view of one of the motor cover halves shown in FIG. 4:
FIG. 8 is a fragmentary sectional view taken generally along the line 8--8 of FIG. 7 and in the direction indicated generally;
FIG. 9 is a top plan view of the control panel shown in FIG. 4; and
FIG. 10 is a side elevational view of the control panel of FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, an outboard motor 10 is provided with a motor cowl 12 which includes an upper motor cover 14 and a lower motor cover 16, the lower motor cover 16 being provided in two parts, a first cover portion 18 and a second cover portion 20 (best seen in FIG. 4). The first and second cover portions 18, 20 are generally mirror images of each other and are 1 configured to meet and partially enclose an internal combustion engine 22 (shown hidden in FIG. 1). The cover portions 18, 20 are preferably injection-molded of a thermoplastic material; however, other molding processes are contemplated, including, but not limited to, sheet molding. The material used for the cover portions 18, 20 is preferably a rigid plastic, such as an impact modified thermoplastic polyester alloy with 30% glass reinforcement such as VANDAR 4662 Z available from Celanese Corporation. The use of injection molded plastic for the lower motor cover 16 permits a wider variety of styling configurations than is available from conventional die cast aluminum covers.
An exhaust housing 24 depends from the engine 22 and is attached at a lower end 26 to a gear case housing 28. A propeller 30 is provided at a lower rear portion of the gear case housing 28 for propelling a boat through water, as is well known.
A steering handle assembly 32 is located at a front end 34 of the motor 10. The steering handle assembly 32 includes a steering arm or bracket 36, a tiller handle 38, an axially rotatable grip portion 40 and a stop switch assembly 42 located on the assembly 32. A starter rope handle 46 is disposed within a recessed mounting panel 48 which is secured within an opening 49 (best seen in FIG. 4) in the upper motor cover 14.
A stern bracket assembly 50 is provided with a vertical housing 52 including a shaft 54 axially disposed therein. A bracket 56 attached to the exhaust housing 24 surrounds a lower end of the housing 52 and permits pivotal movement of the housing 52. A lower end of the shaft 54 pivotally engages a pivot bore 58 (best seen in FIG. 4) of the exhaust housing 24, and an upper end of the shaft 54 engages a pivot bore 60 located in an upper flange 62 of the exhaust housing 24 (best seen in FIG. 4). The stern bracket assembly 50 also includes at least one and preferably two threaded clamp members 6 for securing the bracket assembly 50 to the stern of a boat as is well known. The stern bracket assembly 50 permits the motor 10 to be pivotally controlled by the steering assembly 32 for steering purposes.
Referring now to FIGS. 2 and 4, the motor 10 further includes a control panel 64 centrally disposed between respective front edges 66, 68 of the first and second cover portions 18 and 20. The control panel 64 includes at least one motor control access opening, such openings possibly including a steering bracket opening 70 configured to allow the passage of the steering bracket 36 therethrough, a remote control shift and throttle cable access opening 72, a choke control access opening 74, and/or a twist grip throttle cable opening 76. An outwardly projecting latch attachment formation 78 (best seen in FIGS. 9 and 10) is centrally located upon a front surface 79 of the control panel 64. A fuel line connector location 80 may be secured to a support formation 82 located either on the second cover portion 20, as shown, on the first cover portion 18, or to the control panel 64 at point 83.
Referring now to FIGS. 4, 5 and 6, the upper motor cover 14 is secured to the lower motor cover 16 by means of a latch assembly 84 located at the rear end 86 of the motor 10. The latch assembly 84 includes a latch hook 88 secured at a head end 90 to a lower rear portion of the upper motor cover 14 by means of fasteners 91 (best seen in FIG. 6), which may be threaded fasteners or rivets. The latch hook 88 further includes a depending body 92 and a pair of depending arms 94, 96. A tension spring 98 is secured at each end to one of the depending arms 94, 96 and is disposed upon the latch hook 88 so as to be generally horizontal. The hook body 92 is provided with a plurality of parallel serrations 100 on a rear face 101.
The latch assembly 84 also includes a latch body 102 which defines a cavity 104 configured for accommodation of the latch hook 88. The latch body 102 includes a generally L-shaped latch handle 106 having a gripping leg 108 with a handle 109, and a generally vertically positioned serrated leg 110. The serrated leg 110 has a plurality of serrations 112 on an inner face thereof which are disposed so as to operationally engage the serrations 100 on the latch hook 88. The latch handle 106 is secured at an upper end 114 to the latch body 102 so that the latch handle pivots in a general direction indicated by the arrow 116. The latch assembly 84 is preferably fabricated of durable plastic, and as such, the upper end of the latch handle 106 may be integral with the latch body 102. A leaf spring 118 is secured to the latch body 102 at a lower end of the cavity 104 to bias the latch handle 106 against the latch hook body 92 so that the serrations 112 lockingly engage the serrations 100 and prevent upward movement of the upper motor cover 14 once the latch assembly 84 is closed (best seen in FIG. 6).
Referring now to FIG. 6, which shows the latch assembly 84 in the closed or locked position, when the upper cover 14 is locked in position upon the lower cover 16, the spring 98 is held in an extended, biased position against a ledge or shoulder 120 of the latch body 102. When the latch hook 88 is to be released, the operator pulls the handle 109, which overcomes the biasing force of the spring 118, and releases the engagement between the serrations 100, 112. At this point, the spring 98 is free to resume its generally unbiased, horizontal position (best seen in FIG. 5) and, in so doing, forces the upper cover 14 to pop up. Thus, this operational aspect of the latch assembly 84 gives the operator an indication that the upper motor cover 14 has been released, and also allows the operator to remove the upper motor cover 14 one-handed.
Referring now to FIG. 4, at the front end 34 of the motor 10, the upper motor cover 14 and lower motor cover 16 are releasably secured to each other by means of a hook 122 which depends from a front end portion of the cover 14. The hook 122 is configured to engage the latch attachment formation 78 located on the control panel 64.
Referring now to FIGS. 3, 4, 7 and 8, the lower motor cover 16 of the invention is described in greater detail. Each of the first and second cover portions 18, 20, which are generally configured to be mirror images of each other, respectively, includes an outer wall 124, 126, an upper edge 128, 130, and an inside edge 132, 134. When the first and second motor cover portions 18, 20, respectively, are secured to each other (best seen in FIG. 2), the respective inside edges 132, 134 are in engagement with each other. If desired, the inside edges 132, 134 may be provided with mating tongue-in-groove configurations 137, 135 (shown hidden in FIG. 2) for attaching the first and second cover portions 18, 20 to each other in a manner which inhibits the entry of moisture into the cowl 12.
Each cover portion 18, 20 is provided with a respective laterally opening groove formation 136, 138, the groove formation being integral with and being disposed generally horizontal relative to the outer wall 124, 126 of each of the cover portions 18, 20. The groove formations 136, 138 are configured so that when the lower motor cover 16 is assembled, a substantially rectangular groove is defined. The groove formations 136, 138 are also dimensioned to accommodate the upper flange 62 of the exhaust housing 24 (best seen in FIG. 4), when the flange 62 is equipped with an annular elastomeric seal 140. The seal 140 is disposed around the flange 62 and the assembled seal and flange are then seated within the groove formations 136, 138. In this manner, the lower motor cover 16 is securely disposed relative to the motor 10 and is sealed from entry of moisture from below.
The groove formations 136, 138 are each integrally joined to a respective inner face 142, 144 of each of the motor cover portions 18, 20 by means of a preferably continuous web 146, 148. In view of the fact that the lower motor cover portions 18, 20 are each preferably injection molded, and as such a wide variety of motor cowl styling configurations are available, including forming the outer walls 124, 126 to be as smooth as possible for aesthetic reason.. As such, it would be undesirable for so-called "sink" marks to appear on the exterior of the walls 124, 126 to indicate a linear attachment point "P" of the web 148 to the inner face 142, 144 of the motor cover portions 18, 20. In order to avoid any sink marks appearing on the outer walls 124, 126, it is preferred that the outer walls 124, 126 be thickened along the linear attachment point "P" relative to the thickness of the web 148. The thickened portion is designated 149 (best seen in FIG. 8). It is preferred that the thickness of the web 148 be as small as possible relative to the thickness of the thickened portion 149 and still be capable of supporting the groove formations 136, 138.
Referring now to FIGS. 4 and 7, the first and second motor cover portions 18, 20 are secured to each other by means of front, rear and lower integral boss formations, respectively designated 150, 152 and 153 on the cover portion 18, and 154, 156 and 157 on the cover formation 20. The corresponding front boss formations 150, 154, rear boss formations 152, 156 and lower boss formations 153, 157 are generally coaxially aligned to permit the engagement therethrough of threaded fasteners 158. The boss formations 150, 152, 153, 154, 156 and 157 ensure secure attachment of the cover portions 18, 20 without the necessity of excessive supplemental mounting hardware. The first and second motor cover portions 18, 20 are also provided with steering arm channel formations 160, 162 which, when joined, form a steering arm channel 164 (best seen in FIG. 2). A rear gripping recess 163 is also integrally formed at the rear 34 of each cover portion 18, 20.
Referring now to FIGS. 3, 4, 7 and 10, the upper edges 128, 130 of each of the lower motor cover portions 18, 20 are provided with a shoulder respectively designated 166, 168 and an upwardly projecting seal retaining formation respectively designated 170, 172. The respective upper ends 171, 173 of each of the seal retaining formations 170, 172 have a barb-shaped, frustoconical or trapezoidal cross-section (best seen in FIG. 3).
An elastomeric motor cover seal 174 is provided which defines a generally rectangular shape (best seen in FIG. 4). The seal 174 is preferably made of vinyl nitrile or equivalent material and is extruded as one elongate piece, the ends of which are joined together by adhesive or equivalent permanent bonding procedure. The seal 174 includes an elongate body 176 configured to be secured upon the seal retaining formations 170, 172, and which conforms to the generally rectangular shape defined by the upper edges 128, 130 of the lower motor cover portions 18, 20, as well as by an upper edge 178 of the control panel 64. The upper edge 178 of the control panel 64 is also provided with a barb-shaped, frustoconical or trapezoidal seal retaining formation 179. The seal 174 also includes an attachment portion 180 which defines a generally barb-shaped, frustoconical or trapezoidal recess 182 dimensioned to matingly engage the barb-shaped upper ends 171, 173 of the seal retaining formations 170, 172.
The seal body 176 also includes a compressible tubular portion 184 which is integral with the body 176 and which has a lower end 186 configured to seat upon the shoulders 166, 168, as well as upon a shoulder 187 of the control panel 64. The tubular portion 184 is disposed on the seal 174 relative to the shoulders 166, 168 and 187 so that a lower edge 188 of the upper motor cover 14 which opposes the upper edges 128, 130 of the lower motor covers 16, 18 will engage and vertically compress the tubular portion in a similar manner to that shown in FIG. 3. In this manner, the entry of moisture into the cowl 12 is prevented. In addition, the seal body 176 includes a wiping formation 190 which is integral with the body 176. The wiping formation 190 is outwardly projecting and generally wedge-shaped, and has a tip 192. The tip 192 is designed to be biased against an inside wall 194 of the upper motor cover 14. The wiping formation 190 and the tip 192 are provided with the wedge shape in order to guide the upper motor cover 14 to its closed position upon the lower motor cover 16. Also, the tip 192 will exert a slight outward biasing force against the upper motor cover 14 to maintain the cover under compression and to hold the cover in position.
Referring now to FIGS. 2, 4, 9 and 10, the control panel 64 is described in greater detail. The control panel 64 includes vertical tongue formations 196 on each of the two vertical side edges 198, 200 for engagement with corresponding groove formations (not shown) on the forward edges 66, 68 of the lower motor cover portions 18, 20. In addition, each side portion 198, 200 includes a mounting tab 202 having a U-shaped recess 204 to facilitate the attachment of the control panel 64 to each forward edge 66, 68 of the respective lower motor cover portions 18, 20. In an alternative embodiment, additional U-shaped tabs can be located at the upper and outer edges of the control panel to restrict any lateral motion of the side covers. A rear body portion 206 includes a recess formation 208 to accommodate the shift linkage of the motor 10 (not shown). It is preferred that the control panel 64 is fabricated by injection molding or other molding process using similar thermoplastic materials as are used to fabricate the lower motor cover portions 18, 20.
The cowl 12 is assembled upon the motor 10 by placing the seal 140 around the flange 62 of the exhaust housing 24. The lower motor cover portions 18, 20 are then positioned on either side of the exhaust housing 24 so that the seal 140 and the flange 62 are engaged in the grooves 136, 138. The control panel 64 is then secured at the front edges 66, 68 of the respective lower motor cover halves 18, 20 by means of the tabs 204. The lower motor cover portions 18, 20 are then secured to each other by means of the fasteners 158. Next, the rectangular-shaped seal 174 is secured to the upper edges 128, 130 of the lower motor cover 16 by means of the barb-shaped recess formation 182 being pressed upon the barb-shaped seal retaining formations 170, 172.
Concurrently with the attachment of the lower motor cover portions 18, 20 and the control panel 64 to each other, the latch assembly 84 may be assembled by securing the latch hook 88 to the rear end 86 of the upper motor cover 14 and the latch body 102 to the lower motor cover 16. Likewise, the hook 122 is anchored to the front end 34 of the upper motor cover 14 for engagement with the latch attachment formation 78 on the control panel 64. As the upper motor cover 14 is secured to the lower motor cover 16, the tubular portion 184 of the seal 174 is compressed and the wedge-shaped wiping formation 190 engages the inner face 194 of the upper motor cover 14 to maintain it in position and to create a watertight seal for the motor 10.
Thus, the present motor cover seal may be positively attached to the upper edge of the motor cover portions without the use of adhesive or stitching, and is readily replaceable when necessary.
While a particular embodiment of the motor cover seal of the invention has been shown and described, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.
|
A motor cover seal for sealing opposed edges of upper and lower outboard motor convers includes an elongate body constructed and arranged for disposition between the opposed edges of the upper and lower covers, an attachment portion on the body configured to be secured to the lower motor cover, and a compressible portion on the body configured to be compressed by the closing of the upper motor cover against the lower motor cover.
| 5
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2004-253070, filed on Aug. 31, 2004, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a semiconductor storage apparatus including memory cells that need refresh operation.
[0004] 2. Related Art
[0005] As for the conventional DRAM cell consisting of one transistor and one capacitor including a trench capacitor or a stacked capacitor, there is a concern that its fabrication may become difficult as it becomes finer. As a candidate for a future DRAM memory cell, a new memory cell FBC (Floating Body Cell) is proposed (see Japanese Patent Application Laid-Open Nos. 2003-68877 and 2002-246571). In the FBC, majority carriers are formed in a floating body of an FET (Field Effect Transistor) formed on SOI (Silicon on Insulator) or the like, to store information.
[0006] In the FBC, an element unit for storing one bit information is formed of only one MISFET (Metal Insulator Semiconductor Field Effect Transistor). Therefore, the occupation area of one cell is small, and storage elements having a large capacity can be formed in a limited silicon area. It is considered that the FBC can contribute to an increase of the storage capacity.
[0007] The principle of writing and reading for an FBC formed on PD-SOI (Partially Depleted—SOI) can be described as follows by taking an N-type MISFET as an example. A state of “1” is defined as a state in which there are a larger number of holes. On the contrary, a state in which the number of holes is smaller is defined as “0.”
[0008] The MISFET includes an nFET formed on SOI. Its source is connected to GND (0 V) and its drain is connected to a bit line (BL), whereas its gate is connected to a word line (WL). Its body is electrically floating.
[0009] For writing “1” into the FBC, the transistor is operated in the saturation state. For example, the word line WL is biased to 1.5 V and the bit line BL is biased to 1.5 V. In such a state, a large number of electron-hole pairs are generated near the drain by impact ionization. Among them, electrons are absorbed to the drain terminal. However, holes are stored in the body having a low potential. The body voltage arrives at a balanced state in which a current generating holes by impact ionization balances a forward current of a p-n junction between the body and the source. The body voltage is approximately 0.7 V.
[0010] A method of writing data “0” will now be described. For writing “0,” the bit line BL is lowered to a negative voltage. For example, the bit line BL is lowered to −1.5 V. As a result of this operation, a p-region in the body and an n-region connected to the bit line BL are greatly forward-biased. Therefore, most of the holes stored in the body are emitted into the n-region. A resultant state in which the number of holes has decreased is the “0” state. As for the data reading, distinguishing between “1” and “0” is conducted by setting the word line WL to, for example, 1.5 V and the bit line BL to a voltage as low as, for example, 0.2 V, operating the transistor in a linear region, and detecting a current difference by use of an effect (body effect) that a threshold voltage (Vth) of the transistor differs depending upon a difference in the number of holes stored in the body. The reason why the bit line voltage is set to a voltage as low as 0.2 V in this example at the time of reading is as follows: if the bit line voltage is made high and the transistor is biased to the saturation state, then there is a concern that data that should be read as “0” may be regarded as “1” because of impact ionization and “0” may not be detected correctly.
[0011] The FBC stores information relating to the difference of the number of majority carriers. While data is retained, the word line is set to a negative value with the source of the grounded cell. In both the “1” state and the “0” state, since the potential of the body is thus set to negative values by using capacitive coupling between the word line and the body, p-n junction between the body and the source and p-n junction between the body and the drain are reverse-biased. In this way, a current flowing between the body and the source and a current flowing between the body and drain are held down to low values.
[0012] Since there is a slight reverse bias current across each PN junction, however, holes flow into the body little by little. Since the gate is set to a negative potential as compared with the drain, there is also a flow of holes to the body caused by GIDL (Gate Induced Drain Leakage). Since the data “1” is the state in which the number of holes is originally large, therefore, it is sufficient to replenish holes which overflow when the body potential is raised to a positive value in ordinary read/write operation. As for data “0”, however, refresh operation for bailing holes over a certain fixed period becomes necessary.
[0013] As compared with the conventional IT (Transistor)—IC (Capacitor) type DRAM cell, the FBC is small in P-N- junction area because the SOI substrate is used and the leak current can be held down to a comparatively small value. However, the capacitance for storing electric charge is less than 1 fF in the FBC whereas it is several tens fF in the conventional IT-IC type DRAM cell. Therefore, it is inevitable that the data retaining time becomes shorter than that in the DRAM. Therefore, there is a drawback that the frequency of refreshing becomes high and the external access period for conducting the read/write operation is limited by that amount.
[0014] In a VSRAM (Virtually Static RAM) including conventional IT-IC type cells, if read/write operation is conducted from the outside and a competition with the internal refresh operation occurs, the read/write operation must be kept waiting until the refresh operation is completed (see K. Sawada et al., “A 30-uA Data-Retention Pseudostatic RAM with Virtually Static RAM Mode”, IEEE J. Solid-State Circuits, vol. 23). The reason is because the IT-IC cell is a destructive read-out cell. In other words, once the WL is activated and data begins to be read out, cell data is destroyed if interruption occurs without amplifying the data and completing the rewrite operation. This results in a drawback that the random access time and the random write time are prolonged to twice or more if the VSRAM is composed by using the IT-IC type DRAM.
SUMMARY OF THE INVENTION
[0015] A semiconductor storage apparatus' according to one embodiment of the present invention, comprising:
[0016] memory cells which need refresh operation; and
[0017] a refresh control circuit which suspends the refresh operation when external access for reading out from or writing into the memory cells is requested.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a circuit diagram showing an internal configuration of a semiconductor storage apparatus according to an embodiment of the present invention.
[0019] FIG. 2 is a detailed circuit diagram showing an internal configuration of a sense amplifier 1 provided in the semiconductor apparatus of FIG. 1 .
[0020] FIG. 3 is a detailed circuit diagram showing an internal configuration of a sense core unit 11 .
[0021] FIG. 4 is a block diagram showing a general configuration of a semiconductor storage apparatus according to the present embodiment.
[0022] FIG. 5 is a circuit diagram showing an example of an internal configuration of the refresh interval timer 31 .
[0023] FIG. 6 is a circuit diagram showing an example of an internal configuration of the tRAS timer 32 .
[0024] FIG. 7 is a block diagram showing an example of an internal configuration of the address counter 33 .
[0025] FIG. 8 is a circuit diagram showing an example of an internal configuration of a frequency divider circuit 85 .
[0026] FIG. 9 is a circuit diagram showing an example of an internal configuration of the refresh controller 34 .
[0027] FIG. 10 is a circuit diagram showing an example of an internal configuration of the row address switch 37 .
[0028] FIG. 11 is a circuit diagram showing an example of an internal configuration of the row decoder 39 .
[0029] FIG. 12 is a circuit diagram showing an example of an internal configuration of the RINT generator 35 .
[0030] FIG. 13 is an operation timing diagram in the case where a refresh request is given when the external signal BRAS is active.
[0031] FIG. 14 is an operation timing diagram in the case where the refresh request signal REFREQ is given when the external signal BRAS is at the high level (precharge state), but immediately thereafter the external signal BRAS becomes the low level.
[0032] FIG. 15 is an operation timing diagram in the case where the refresh request signal REFREQ is given when the external signal BRAS is at the high level (precharge state) and the precharge state is continued until the refresh operation is completed.
[0033] FIG. 16 is an operation timing diagram in the case where an interrupt is caused in the middle of the refresh operation by the ordinary read operation.
[0034] FIG. 17 is a block diagram showing a general configuration of a semiconductor storage apparatus according to the second embodiment.
[0035] FIG. 18 is a block diagram showing an example of an internal configuration of the interval timer & controller 145 .
[0036] FIG. 19 is a timing diagram of signals generated by the interval timer & controller shown in FIG. 18 .
DETAILED DESCRIPTION OF THE INVENTION
[0037] Hereafter, an embodiment of the present invention will be described with reference to the drawings.
[0000] (First Embodiment)
[0038] FIG. 1 is a circuit diagram showing an internal configuration of a semiconductor storage apparatus according to an embodiment of the present invention. FIG. 2 is a detailed circuit diagram showing an internal configuration of the sense amplifier 1 provided in the semiconductor apparatus of FIG. 1 . FIG. 3 is a detailed circuit diagram showing an internal configuration of the sense core unit 11 , which is a core portion in the sense amplifier 1 shown in FIG. 2 .
[0039] The semiconductor storage apparatus shown in FIG. 1 includes a plurality of sense amplifiers 1 arranged side by side approximately in the center, and cell arrays 2 arranged on both sides of the sense amplifiers 1 . Although omitted in FIG. 1 , the semiconductor storage apparatus according to the present embodiment includes a read/write control circuit.
[0040] As shown in FIG. 1 , a cell array 2 includes 256 word lines arranged on the left or right side of the sense amplifiers 1 . Although not illustrated, the cell array 2 includes 1024 pairs of bit lines. In other words, 1024 sense amplifiers 1 are arranged. FBCs 3 are disposed near intersections of even-numbered-word lines and true lines of respective bit lines and intersections of odd-numbered word lines and complement lines of respective bit lines, respectively. In this way, the semiconductor storage apparatus shown in FIG. 1 has a cell arrangement of a folded bil line scheme.
[0041] Each of the cell arrays 2 arranged on the left and right sides of the sense amplifiers 1 includes bit line equalize transistors 4 , each of which short-circuits a bit line to a source potential of the FBCs 3 , and dummy cells 5 . The bit line equalize transistors 4 are connected near intersections of equalize signal lines EQLL 0 , EQLL 1 , EQLR 0 and EQLR 1 and bit lines. Dummy cells 5 are connected near intersections of dummy word lines DWLL 0 , DWLL 1 , DWLR 0 and DWLR 1 and bit lines. Prior to read operation for FBCs 3 , data “1” and “0” are written into the dummy cells 5 alternately in the word line direction by a circuit which will be described later.
[0042] NMOS transistors 6 are connected between one line included in a bit line pair and one line included in an adjacent bit line pair. Signals AVL 0 , AVR 0 , AVL 1 and AVR 1 are supplied to gates of the NMOS transistors 6 .
[0043] As shown in FIG. 2 , a transfer gate 15 formed of an NMOS transistor is connected between each bit line and a sense core 11 . These transfer gates 15 are switched to turn on or off by φTL and φTR. Hereafter, paths located on the sense amplifiers 1 side with respect to the transfer gates 15 are referred to as sense nodes SN 0 , BSN 0 , SN 1 and BSN 1 .
[0044] Each CMOS transfer gate 12 switches to cross-connect sense nodes to bit lines. NMOS transistors in the transfer gates 12 are controlled by signals FBL 0 , FBL 1 , FBR 0 and FBR 1 , whereas PMOS transistors in the transfer gates 12 are controlled by signals BFBL 0 , BFBL 1 , BFBR 0 and BFBR 1 .
[0045] A transistor 13 is connected to each of bit lines BLL 0 , BBLL 0 , BLR 0 and BBLR 0 to couple the bit line to the ground potential VBLL. “0” is written into dummy cells 5 connected to the bit lines BLL 0 , BBLL 0 , BLR 0 and BBLR 0 by the transistors 13 . A transistor 14 is connected to each of adjacent bit lines BLL 1 , BBLL 1 , BLR 1 and BBLR 1 to couple the bit line to a power supply voltage VBLH. “1” is written into dummy cells 5 connected to the bit lines BLL 1 , BBLL 1 , BLR 1 and BBLR 1 by the transistors 14 .
[0046] For example, it is now supposed that WLL 0 in the cell array 2 located on the left side of the sense amplifiers 1 is activated. In this case, the dummy bit line DWLL 1 and the signal AVL 1 are also activated at the same time. As a result, FBCs 3 are coupled to the bit lines BLL 0 and BLL 1 . At the same time, dummy cells 5 having “0” written therein are coupled to a bit line BBLL 0 , and dummy cells 5 having “1” written therein are coupled to a bit line BBLL 1 . And the transistor 6 turns on, and the bit lines BBLL 0 and BBLL 1 are short-circuited to each other. Therefore, currents flowing through the two dummy cells are averaged. It is equivalent to that an intermediate current between “1” and “0” cell currents flows through the bit lines BBLL 0 and BBLL 1 . In the case of a “0” cell, therefore, potentials on the sense nodes SN 0 and SN 1 become higher than those on the sense nodes BSN 0 and BSN 1 . In the case of a “1” cell, potentials on the sense nodes SN 0 and SN 1 become lower than those on the sense nodes BSN 0 and BSN 1 . When these potential differences have been sufficiently developed, a signal BSAN becomes a low level and a signal SAP becomes a high level.
[0047] As shown in FIG. 3 , the sense core unit 11 includes a current load circuit 21 formed of a current mirror circuit, and dynamic latch circuits 22 and 23 connected to the pair of bit lines SN 0 and BSN 0 . The signal BSAN is input to a connection node between two NMOS transistors forming the dynamic latch circuit 22 . The signal SAP is input to a connection node between two PMOS transistors forming the dynamic latch circuit 23 . When the potential difference between the pair of sense nodes SN 0 and BSN 0 or SN 1 and BSN 1 has been sufficiently developed, the dynamic latch circuits 22 and 23 conduct latch operation.
[0048] It has been found that the FBC 3 is not a complete non-destructive read-out cell. The reason is because the charge pumping phenomenon is present. If the on-off operation of a transistor is repeated, i.e., the so-called pumping operation at the gate is conducted a plurality of times, the inversion state and the accumulation state on the gate silicon surface are repeated alternately and holes gradually disappear at an interface between the silicon surface and SiO 2 . This is the charge pumping phenomenon.
[0049] The number of holes that disappear due to one state change between inversion and accumulation depends on a density Nit of interface levels at the Si—SiO 2 interface. For example, supposing that Nit=1×10 1 cm −2 and W (channel width)/L (channel length) of a cell transistor=0.1 μm /0.1 μm, the area of the Si—SiO 2 interface becomes 1.0×10 −10 cm 2 per cell and consequently the number of interface levels per cell becomes approximately one on the average. The number of holes stored in one FBC 3 has a difference of approximately 1,000 when the data is “1” or “0”. If the word line WL is subjected to pumping approximately 1,000 times, therefore, data “1” completely changes to data “0”.
[0050] Practically, if the word line WL is subjected to pumping approximately 500 times, then the readout margin for the data “1” is lost and the risk that a fail may occur becomes high. Therefore, the FBC 3 is neither a destructive read-out cell nor a complete non-destructive read-out cell. The FBC 3 is so to speak a “quasi non-destructive read-out cell”.
[0051] However, data in the FBC 3 is not destroyed by only one read operation. Therefore, it is allowed for an external read or write operation to interrupt the refresh operation. This means that the external access can have priority over the internal refresh operation in the VSRAM (when competing with the refresh operation). Thus, it becomes possible to design the VSRAM whose performance is equivalent to the access time and write time of the FBC 3 memory in which self-refresh operation is not conducted.
[0052] FIG. 4 is a block diagram showing a general configuration of a semiconductor storage apparatus according to the present embodiment. The semiconductor storage apparatus shown in FIG. 4 includes a refresh interval timer 31 to conduct time measurement in order to prescribe an interval period between a refresh operation of the FBC 3 and the next refresh operation, a tRAS timer 32 to conduct time measurement in order to prescribe a tRAS period required for the refresh operation, an address counter 33 to generate an address of an FBC 3 to be refreshed, a fresh controller 34 to control the refresh operation and the external access operation, a RINT generator 35 to generate a control signal RINT described later, a row address buffer 36 , a row address switch 37 , a row path controller 38 to control the row address, a row decoder 39 , a column address buffer 40 , a column & data path controller 41 , a column decoder 42 , a data input-output buffer 43 , and a DQ buffer 44 .
[0053] FIG. 5 is a circuit diagram showing an example of an internal configuration of the refresh interval timer 31 . The timer shown in FIG. 5 includes a bias circuit 51 , a ring oscillator 52 , and an output circuit 53 . The bias circuit 51 includes a PMOS transistor 54 having a current mirror connection in which its gate is short-circuited to its drain, an NMOS transistor 55 having a current mirror connection in which its gate is short-circuited to its drain in the same way, and a resistor 56 connected between the drain of the PMOS transistor 54 and the drain of the NMOS transistor 55 .
[0054] The ring oscillator 52 includes five-stage logic inversion circuits 57 connected in series. The output of a logic inversion circuit 57 located at the final stage is fed back to the input of a logic inversion circuit 57 located at the first stage. Each of the logic inversion circuits includes a PMOS transistor 58 , a PMOS transistor 59 , an NMOS transistor 60 and an NMOS transistor 61 connected in series between a power supply voltage and a ground voltage.
[0055] The PMOS transistor 54 in the bias circuit 51 constitutes a current mirror circuit in conjunction with the PMOS transistor 58 and PMOS transistors 62 to 65 in the ring oscillator 52 . The NMOS transistor 55 in the bias circuit 51 constitutes a current mirror circuit in conjunction with the NMOS transistor 61 and NMOS transistors 66 to 69 in the ring oscillator 52 . Therefore, a current that is equal in magnitude to that flowing through the bias circuit 51 flows through the PMOS transistors 58 and 62 to 65 and the NMOS transistors 61 and 66 to 69 in the ring oscillator 52 .
[0056] The output circuit 53 includes an inverter 70 to invert the output RFECT of the ring oscillator 52 , inverters 71 to 75 of five stages connected in series, and a NOR circuit 76 to conducts a NOR operation on an output of the inverter 75 disposed at the final stage and the output of the inverter 70 .
[0057] The NOR circuit 76 conducts the NOR operation on the signal BREFCT obtained by inverting the input-output signal REFCT of the ring oscillator 52 and the signal obtained by inverting the signal BREFCT by means of the inverters 71 to 75 .
[0058] The refresh interval timer 31 flows a current equal to that flowing through the bias circuit 51 , through stages of the ring oscillator 52 . Therefore, high precision time measurement that does not depend upon dispersion of device characteristics of MOSFETs can be conducted. A signal REFREQ output from this timer 31 is a positive pulse having the measured time as its period.
[0059] FIG. 6 is a circuit diagram showing an example of an internal configuration of the tRAS timer 32 . The tRAS timer 32 shown in FIG. 6 includes an inverter 81 , a delay circuit 82 , and an inverter 83 connected in series. The tRAS timer 32 outputs a signal REFTRAS obtained by delaying a signal REFRESH, which instructs the refresh operation, by time τ3. A time period since the signal REFRESH becomes a high level until the signal REFTRAS becomes a high level can be considered to be a time period over which a signal BRAS, which is typically an external signal, is active (at a low level), i.e., a time period over which the refresh operation is being conducted. In other words, the tRAS timer 32 measures time τ3 required for the refresh operation.
[0060] FIG. 7 is a block diagram showing an example of an internal configuration of the address counter 33 . As shown in FIG. 7 , the address counter 33 includes a plurality of frequency divider circuits 85 connected in series. An output logic of each frequency divider circuit 85 changes at a falling edge of its input signal. Each frequency divider circuit 85 outputs a divided frequency signal, which is obtained by dividing its input signal by two in frequency.
[0061] FIG. 8 is a circuit diagram showing an example of an internal configuration of the frequency divider circuit 85 . As shown in FIG. 8 , the frequency divider 85 includes a logic inversion circuit 91 having an output logic switched by a logic in which a signal BCi- 1 is at a low level and a signal Ci- 1 is at a high level, a logic inversion circuit 92 having an output logic switched by a logic in which the signal Ci- 1 is at a low level and the signal BCi- 1 is at a high level, a logic inversion circuit 93 having an output logic switched by a logic in which the signal Ci- 1 is at a low level and the signal BCi- 1 is at a high level, a logic inversion circuit 94 having an output logic switched by a logic in which a signal BCi- 1 is at a low level and a signal Ci- 1 is at a high level, and inverters 95 to 97 . Each of the logic inversion circuits includes a PMOS transistor, a PMOS transistor, an NMOS transistor and an NMOS transistor connected between a power supply terminal and a ground terminal.
[0062] FIG. 9 is a circuit diagram showing an example of an internal configuration of the refresh controller 34 . The refresh controller 34 shown in FIG. 9 includes flip-flops 101 and 102 each including two cross-connected NAND circuits, inverters 103 to 107 , and NAND circuits 109 and 110 .
[0063] FIG. 10 is a circuit diagram showing an example of an internal configuration of the row address switch 37 . The row address switch 37 includes inverters 111 and 112 , OR circuits 113 to 116 , NAND circuits 117 and 118 , and inverters 119 and 120 .
[0064] FIG. 11 is a circuit diagram showing an example of an internal configuration of the row decoder 39 . The row decoder 39 includes a PMOS transistor 121 and four NMOS transistors 122 to 125 connected in series between a voltage VWLHW which is provided on the word line when writing data into a memory cell and a voltage VWLL which is provided on the word line when retaining data, three inverters 126 to 128 connected in series to the connection node between the PMOS transistor 121 and the NMOS transistor 122 , and a PMOS transistor 129 connected between the connection node and the voltage VWLHW.
[0065] Supposing that the refresh request signal REFREQ formed of a positive pulse is output when the external signal BRAS is at a high level (a precharge state of the FBC 3 ), the inverted signal REXT for the signal BRAS is at a low level and consequently the refresh signal REFRESH output from the refresh controller 34 shown in FIG. 9 becomes a high level. As a result, a refresh operation is started.
[0066] If time τ3 elapses since the refresh signal becomes the high level, then the output signal REFTRAS of the tRAS timer 32 shown in FIG. 6 becomes the high level, and the flip-flop 102 in a latter stage in the refresh controller shown in FIG. 9 is reset. As a result, the refresh signal REFRESH falls to a low level and the refresh operation is completed.
[0067] If the external signal BRAS falls to a low level before elapse of the time τ3, i.e., (if an interrupt is caused during the refresh operation by the ordinary read/write operation), then the inverted signal REXT for the external signal BRAS becomes a high level. As a result, the flip-flop 102 in the latter stage in the refresh controller 34 shown in FIG. 9 is reset, and the refresh signal REFRESH becomes the low level. In other words, if an interrupt is conducted in the middle of the refresh operation by ordinary operation, then the refresh operation is forcibly suspended. And the output of the NAND circuit 110 is forcibly set to a high level by the inverted signal of the signal REXT in order to prevent the output of the flip-flop 101 in the former stage in the refresh controller 34 from being reset even if the delay time of τ3 elapses and the output signal REFTRAS of the tRAS timer 32 shown in FIG. 6 becomes the high level.
[0068] If thereafter the ordinary read/write operation is finished and the external signal BRAS becomes the high level again, then its inverted signal REXT becomes the low level. At this time, the output signal REFTRAS of the tRAS timer 32 shown in FIG. 6 is at a low level. Therefore, the flip-flop 102 in the latter stage in the refresh controller 34 shown in FIG. 9 is set again, and the refresh signal REFRESH rises. As a result, the refresh operation which has been suspended is resumed.
[0069] At this time, the word line for the refresh operation is selected by inputting an output of the address counter 33 shown in FIG. 7 to the row decoder 39 shown in FIG. 11 via the row address switch 37 shown in FIG. 10 .
[0070] The address counter 33 shown in FIG. 7 conducts count operation in response to signals CTR and BCTR output from the flip-flop 101 in the former stage in the refresh controller 34 shown in FIG. 9 . Even if an interrupt is conducted during the refresh operation by the ordinary read/write operation, however, the flip-flop 101 in the former stage is not reset, and consequently the logics of the signals CTR and BCTR do not change and the address counter 33 does not count up.
[0071] If the refresh operation is suspended by an interrupt and then the refresh operation is resumed, therefore, then the selected word line is the same as the word line before the interrupt and the refresh operation can be conducted correctly from the suspended address.
[0072] If the refresh operation is completed normally without an interrupt conducted by the ordinary read/write operation, both the flip-flops in the former and latter stages in the refresh controller 34 shown in FIG. 9 are reset. As a result, logics of the signals CTR and BCTR change, and the address counter 33 shown in FIG. 7 counts up. At the time of the next refresh operation, the apparatus is ready for refreshing a new word line.
[0073] The signal BPRST input to the flip-flop 101 in the former stage is a signal that maintains the low level immediately after power is turned on in order to prevent the output from becoming vague when both two inputs of the flip-flop 101 are at the high level, and that rises to the high level after the output of the flip-flop 101 has become a required value.
[0074] FIG. 12 is a circuit diagram showing an example of an internal configuration of the RINT generator 35 . The RINT generator 35 includes delay circuits 131 to 133 , AND circuits 134 and 135 , and NOR circuits 136 and 137 . The signal RINT is generated by using the inverted signal REXT for the external signal BRAS and the refresh signal REFRESH.
[0075] The signal REXT becomes the high level, and then the signal RINT rises after a delay time of τ1+τ2. Hereafter, the reason why the time τ1+τ2 is necessary will be described. It is now supposed that the refresh operation is started and a word line is activated and then an interrupt is conducted by the ordinary read/write operation (hereafter referred to as ordinary operation). At this time, the activated word line is inactivated, and a word line corresponding to the ordinary operation is activated to conduct the ordinary operation. When activating the word line for the refresh operation again after completion of the ordinary operation, it is necessary to switch the row decoder 39 properly.
[0076] Typically, as shown in FIG. 11 , the row decoder 39 includes dynamic NAND circuits. The following processing orders are important, i.e. all addresses are set to the low level, then a signal PRCH is set to a low level, then the decoder circuit is precharged properly, then the next address is inputted, and the word line is activated.
[0077] Even if the signals REXT (low to high) and REFRESH (high to low) are almost simultaneously switched in the RINT generator 35 shown in FIG. 12 , therefore, a signal that changes from the high level to the low level is immediately propagated and the signal RINT becomes the low level. Thereafter, the signal RINT is raised to the high level after a wait of time (τ1+τ2), where τ1 is time taken until the row address is reset or time taken until the signal PRCH becomes the low level, and τ2 is time taken until the row decoder 39 is precharged properly or time of a pulse width required for the signal PRCH. Such an operation is implemented by the circuit configuration shown in FIG. 12 .
[0078] As timing of the competition between the ordinary read/write operation and the refresh operation, three cases shown in FIGS. 13 to 15 are conceivable.
[0079] FIG. 13 is an operation timing diagram in the case where a refresh request is given when the external signal BRAS is active. Even if the refresh request signal REFREQ is given when the inverted signal REXT for the external signal BRAS is at the high level, the flip-flop 102 in the latter stage in the refresh controller 34 is not set. Therefore, the refresh signal REFRESH remains at the low level.
[0080] Since the flip-flop 101 in the former stage is set, the flip-flop 102 in the latter stage is set and the refresh signal REFRESH becomes the high level when the signal REXT has become the low level (when the external signal BRAS is not active). If the time tRAS τ3 required for the refresh elapses thereafter, the refresh operation is completed.
[0081] FIG. 14 is an operation timing diagram in the case where the refresh request signal REFREQ is given when the external signal BRAS is at the high level (precharge state), but immediately thereafter the external signal BRAS becomes the low level (active state). Since in this case the refresh request signal REFREQ is given while the inverted signal REXT for the external signal BRAS is at the low level, the refresh signal REFRESH immediately becomes the high level. Since the external signal BRAS becomes active before the tRAS time τ3 required for the refresh operation elapses, however, the flip-flop 102 in the latter stage in the refresh controller 34 shown in FIG. 9 is reset and the refresh signal REFRESH falls to the low level.
[0082] If the external signal BRAS is brought into the precharge state and the signal REXT becomes the low level thereafter, then the flip-flop 102 in the latter stage in the refresh controller 34 shown in FIG. 9 is set again and the refresh signal REFRESH rises. After the tRAS time τ3 required for the refresh operation has elapsed, the refresh operation is completed. Until the refresh operation is resumed since the refresh operation is suspended, the flip-flop 101 in the former stage in the refresh controller 34 shown in FIG. 9 continues to be set. Therefore, the signal CTR, which causes the address counter 33 shown in FIG. 7 to count up, is kept at the high level. Therefore, the word line selected when the refresh operation is suspended is the same as the word line selected when the refresh operation is resumed. Even if the refresh operation is suspended once, the refresh operation can be conducted properly from the address at the time when the refresh operation is suspended.
[0083] FIG. 15 is an operation timing diagram in the case where the refresh request signal REFREQ is given when the external signal BRAS is at the high level (precharge state) and the precharge state is continued until the refresh operation is completed.
[0084] If the request signal REFREQ is output while the inverted signal REXT for the external signal BRAS is at the low level, then the refresh signal REFRESH becomes the hig level. Since the external signal BRAS does not become active within the tRAS time τ3 required for the refresh operation, the refresh operation is completed normally. After the external signal BRAS becomes active thereafter and the ordinary read/write operation is completed, the refresh operation is not started unlike the case shown in FIG. 14 .
[0085] FIG. 16 is an operation timing diagram in the case where an interrupt is caused in the middle of the refresh operation by the ordinary read operation. A word line for the refresh operation is activated at time τ0, and the external signal BRAS becomes the low level (active state) at time τ2. As a result, the word line is immediately inactivated, and a world line for the ordinary read is activated at time τ3. A potential difference between the bit lines BL and BBL becomes gradually large at time τ4. At time τ5, the potential difference on a data line DOUT also becomes large gradually and data readout is conducted.
[0086] After the read operation is finished, the external signal BRAS is raised to the high level (precharge state) at time τ6. As a result, a word line for the ordinary readout is activated at time τ7. Thereafter, the word line for the suspended refresh operation is activated again at time τ8.
[0087] Thus, if the ordinary read/write request is given in the middle of the refresh operation in the first embodiment, the refresh operation is suspended to conduct the ordinary read/write operation and the refresh operation is resumed after the ordinary read/write operation is finished. Therefore, there is no concern that the external access speed may be limited by the refresh operation, and fast operation is made possible.
[0088] By the way, the first embodiment does not cope with the case where before the refresh operation started in response to a given refresh request REFREQ is not yet completed the next refresh request REFREQ is given. Therefore, the time over which the external signal BRAS is active continuously is limited to (refresh interval tREF+2×tRAS (ref)) or less. Here, the refresh interval tREF is an interval prescribed by the refresh interval timer 31 shown in FIG. 5 , and it is time between start of a refresh operation and the next start of a refresh operation. The time tRAS (ref) is time interval τ3 taken for the refresh operation prescribed by the tRAS timer 32 shown in FIG. 6 .
[0089] Typically, the refresh interval tREF is several sec and tRAS is several tens seconds. Therefore, the time over which the external signal BRAS is active continuously is limited by approximately the refresh interval. The interval over which the external signal BRAS is kept active is less than at most several sec.
[0090] In the present embodiment, a semiconductor storage apparatus having a memory capacity of approximately 1 Mbits is supposed and cell arrays 2 each having a capacity of 512 Kbits are disposed on the left and right side of the sense amplifiers 1 . However, the degree of integration and the configuration of the cell arrays 2 are not restricted to those illustrated. Even if the same memory capacity of 1 Mbits is maintained, for example, four cell arrays 2 each having a memory capacity of 256 kbits may be provided.
[0000] (Second Embodiment)
[0091] In a second embodiment, the time over which the external signal BRAS can be kept active is made long as far as possible.
[0092] FIG. 17 is a block diagram showing a general configuration of a semiconductor storage apparatus according to the second embodiment. The semiconductor storage apparatus shown in FIG. 17 includes four cell arrays 2 that can be independently accessed. Each cell array 2 has a memory capacity of 256 kbits, and a chip has a memory capacity of 1 Mbits as a whole. The cell arrays are distinguished by row addresses A 8 R and A 8 L. The cell arrays 2 are driven by RINTO generator 141 , RINT 1 generator 142 , RINT 2 generator 143 and RINT 3 generator 144 . The cell arrays 2 have their own sense amplifiers 1 . Each cell array 2 can conduct the read/write operation and the refresh operation independently.
[0093] In FIG. 17 , circuits of column paths and data paths are omitted for simplification.
[0094] In the present embodiment, it is not determined whether the whole chip is in the precharge state as a whole, but it is determined whether each cell array 2 is in the precharge state and the refresh operation is conducted individually for each cell array 2 . Therefore, a restriction on the permissible time tRAS(rw)over which the external signal BRAS becomes active continuously is alleviated to tRAS(rw)<tREF×n+tRAS(ref)×2, whereas it was tRAS(rw)<tREF+tRAS(ref)×2 in the first embodiment. Here, tRAS(ref) is time required for the refresh operation, and n is the number of cell arrays 2 .
[0095] In the semiconductor storage apparatus shown in FIG. 17 , the refresh interval timer 31 and the refresh controller 34 shown in FIG. 4 are united into one body as an interval timer & controller 145 . The interval timer & controller 145 , the row address buffer 36 and a row address buffer controller 146 are shared by the cell arrays 2 .
[0096] On the other hand, the tRAS timer 32 , the address counter 33 , RINT generators 141 to 144 , the row address switch 37 , the row path controller 38 and the row decoder 39 are provided for each of the cell arrays 2 .
[0097] FIG. 18 is a block diagram showing an example of an internal configuration of the interval timer & controller 145 . FIG. 19 is a timing diagram of signals generated by the interval timer & controller shown in FIG. 18 .
[0098] As shown in FIG. 18 , the interval timer & controller 145 includes two frequency divider circuits 151 connected in cascade. Each of these frequency divider circuits 151 is formed of, for example, a circuit similar to that shown in FIG. 8 . Each of these frequency divider circuits 151 divides its input signal by two in frequency, and outputs a resultant signal. Therefore, the interval timer & controller 145 generates a signal REFCT 1 having a period that is twice the period of REFCT, and a signal REFCT 2 having a period that is four times the period of REFCT.
[0099] The interval timer & controller 145 includes NAND gates 152 to 155 and inverters 156 to 159 to conduct logical operations by using these divided frequency signals. As shown in FIG. 19 , these four inverters generate signals REFREQO, REFREQ 1 , REFREQ 2 and REFREQ 3 that have a cycle equivalent to four times of a cycle of the refresh request signal REFREQ and that are displaced one after another by one cycle.
[0100] Thus, in the second embodiment, a plurality of cell arrays 2 are provided and it is made possible to conduct either the refresh operation or the ordinary read/write operation individually on each cell array 2 . Therefore, the restriction on the time tRAS(rw)over which the external signal BRAS becomes active continuously is alleviated considerably. In other words, tRAS(rw) can be made long by the number of the cell arrays 2 as represented by the expression tRAS(rw)<tREF×n+tRAS(ref)×2. It is thus possible to provide a memory that is further better in convenience to use than the first embodiment.
[0101] If the cell array 2 is formed of FBCs 3 in the first and second embodiments, then the refresh operation needs to be conducted only for FBCs 3 storing data “0”, and it is not necessary to conduct the refresh operation on FBCs 3 storing data “1”. Since data “0” can be written far faster than data “1” (refresh operation), the cycle time required for the refresh operation can be made far shorter than that required for the ordinary read/write operation (ordinary operation). Therefore, the restriction on the minimum specification of the precharge time tRP for the external signal BRAS at the time of ordinary operation can be alleviated considerably. And the timing specifications for tRAS and tRP for the VSRAM of this invention can be nearly the same as those for the ordinary DRAM having no VSRAM function.
|
A semiconductor storage apparatus according to one embodiment of the present invention, comprising: memory cells which need refresh operation; and a refresh control circuit which suspends the refresh operation when external access for reading out from or writing into the memory cells is requested.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent Application No. 10-2006-0123924 filed in the Korean Intellectual Property Office on Dec. 07, 2006, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to a method of requesting resources, a method of allocating resources, and an apparatus therefor by using bandwidth request ranging in a mobile communication system. More particularly, the present invention relates to a method in which a subscriber station requests resources required for transmission of uplink traffic and in which a base station allocates the requested resources, and an apparatus therefor.
(b) Description of the Related Art
FIG. 1 is a flowchart illustrating a procedure of a broadcasting system for broadcasting information in a portable Internet system.
In the portable Internet system, ranging is classified as initial ranging, periodic ranging, bandwidth request (BR) ranging, and hand-off ranging.
The BR ranging is used to request resources that are necessary for a subscriber station to transmit traffic through an uplink. As shown in FIG. 1 , a base station (AP: Access Pointer) broadcasts code division multiple access (CDMA) code information as system information used for BR ranging, which is included in an uplink channel descriptor (UCD). The base station broadcasts information on the uplink resources to all subscriber stations, and the subscriber stations use the uplink resources to transmit a BR code through a UL-MAP.
FIG. 2 is a view illustrating a BR ranging procedure in a portable Internet system.
Referring to FIG. 2 , the BR ranging procedure is performed in the current portable Internet system, as follows.
When uplink traffic occurs, a subscriber station performs BR ranging in order to transmit the uplink traffic as shown in FIG. 2 . More specifically, the subscriber station selects an arbitrary BR code included in the UCD and transmits the selected BR code to the base station in a competition scheme by using resources allocated to the UL-MAP (S 210 ).
Next, when the BR code is successfully received without conflict, the base station broadcasts CDMA_Allocation_IE of the UL-MAP including a frame number of the BR code received from the subscriber station, subchannel information, a received BR code number, and bandwidth allocation information that the subscriber station needs in order to transmit a BR header (S 220 ).
Next, the subscriber station compares the frame number, the subchannel information, and the bandwidth request code number of the CDMA_Allocation_IE included with information that the subscriber station transmits in order to perform the BR ranging. If the information is the same, the subscriber station transmits the BR header by using the uplink resources allocated to the base station (S 230 ). Here, the BR header includes resource information that the subscriber station needs in order to transmit the uplink traffic.
Next, when the BR header is received, the base station allocates the uplink resources with respect to the resources requested by the subscriber station and broadcasts associated information through the UL-MAP (S 240 ). When the resources requested through the UL-MAP are allocated, the subscriber station transmits the uplink traffic.
As described above, in order to transmit the uplink traffic in the portable Internet system, the subscriber station transmits the BR code and is allocated the uplink resources from the base station. In this case, a total of 9 frames are delayed, so there is a problem in that a transmission delay of the uplink traffic increases. Particularly, the transmission delay of the uplink traffic results in an increase in the time taken for transmission of an uplink ACK on a packet that is received through a downlink in a transmission control protocol (TCP)-based Internet service, so there is a problem in that downlink traffic transmission speed is decreased.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
SUMMARY OF THE INVENTION
The present invention has been made in an effort to provide a method of requesting resources, a method of allocating resources, and an apparatus thereof, by using bandwidth request ranging in a mobile communication system having advantages of being capable of decreasing transmission delay of uplink traffic in a portable Internet system from the time of transmitting a bandwidth request code to the time of being allocated requested resources from a base station, and being capable of preventing a decrease in downlink traffic transmission speed that is caused by a transmission delay of an uplink ACK in a TCP-based Internet service.
An exemplary embodiment of the present invention provides a method of allocating uplink resources to a subscriber station by using bandwidth request ranging in a mobile communication system, including: transmitting an uplink channel descriptor (UCD) including code group information to the subscriber station, wherein the code group information is obtained by dividing a bandwidth request code into a plurality of groups and mapping the groups to predetermined data block sizes; receiving a bandwidth request code selected in the subscriber station; determining a code group including the selected bandwidth request code; and allocating a bandwidth through which a data block size corresponding to the determined code group can be transmitted to the subscriber station.
Another embodiment of the present invention provides a method of requesting uplink resource allocation to a base station by using bandwidth request ranging in a mobile communication system, including: receiving an uplink channel descriptor (UCD) including code group information from the base station, wherein the code group information is obtained by dividing a bandwidth request code into a plurality of groups and mapping the groups to predetermined data block sizes; selecting an arbitrary bandwidth request code from a code group corresponding to a data size of traffic that is to be transmitted through an uplink; transmitting the selected bandwidth request code to the base station; allocating a bandwidth through which the traffic is transmitted by the base station; and transmitting the traffic through the allocated bandwidth.
Yet another embodiment of the present invention provides a base station for allocating uplink resources to a subscriber station by using bandwidth request ranging in a mobile communication system, including: a transmission module that transmits an uplink channel descriptor (UCD) including code group information to the subscriber station, wherein the code group information is obtained by dividing a bandwidth request code into a plurality of groups and mapping the groups to predetermined data block sizes; a reception module that receives a bandwidth request code selected in the subscriber station; a determination module that determines a code group including the selected bandwidth request code; and an allocation module that allocates a bandwidth through which a data block size corresponding to the determined code group can be transmitted to the subscriber station.
Still another embodiment of the present invention provides a subscriber station for requesting uplink resource allocation to a base station by using bandwidth request ranging in a mobile communication system, including: a reception module that receives an uplink channel descriptor (UCD) including code group information from the base station, wherein the code group information is obtained by dividing a bandwidth request code into a plurality of groups and mapping the groups to predetermined data block sizes; a selection module that selects an arbitrary bandwidth request code from a code group corresponding to a data size of traffic that is to be transmitted through an uplink; a transmission module that transmits the selected bandwidth request code to the base station; an allocation module that receives an allocation of a bandwidth through which the traffic is transmitted from the base station; an a traffic transmission module that transmits the traffic through the allocated bandwidth.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flowchart illustrating a procedure for broadcasting system information in a portable Internet system.
FIG. 2 is a view illustrating a band request (BR) ranging procedure in a portable Internet system.
FIG. 3 is a view illustrating a procedure for allocating a bandwidth code group based on a size of a block according to an embodiment of the present invention.
FIG. 4 is a flowchart illustrating a procedure for requesting resources and a procedure of allocating the resources by using BR ranging according to an embodiment of the present invention.
FIG. 5 is a view illustrating a BR ranging procedure in a case where a size of uplink traffic is 480 bits or less according to an embodiment of the present invention.
FIG. 6 is a view illustrating a BR ranging procedure in a case where a size of uplink traffic is in a range of 480 bits to 4800 bits according to an embodiment of the present invention.
FIG. 7 is a view illustrating a BR ranging procedure in a case where a size of uplink traffic is 4800 bits or more according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In addition, for clarifying the present invention, portions that are not directly related to the description are omitted in the drawings. Like reference numerals designate like elements throughout the specification.
In the specification, it should be noted that a phrase that a portion “includes” an element means that the other element is not excluded but it can be further included therein if a particularly contrary phase is not disclosed.
In addition, it should be noted that a term “module” disclosed in the specification denotes a unit for performing at least one function or operation, and it can be implemented in combination of hardware, software, or hardware and software.
FIG. 3 is a view illustrating a procedure for allocating a bandwidth code group based on a size of a block according to an embodiment of the present invention.
In the present invention, as shown in FIG. 3 , bandwidth request (BR) codes are divided into several groups, and the BR codes of each group have a specific block size.
When uplink traffic occurs, the subscriber station selects a to-be-transmitted bandwidth request code group based on a size of traffic that is to be transmitted through the uplink. Next, the subscriber station selects an arbitrary bandwidth request code in the bandwidth request code group and transmits the bandwidth request code to the base station.
In an 802.16-based portable Internet system, an IP-based packet service is provided, and a unit of a block size of a data that is transmitted through uplink and downlink is shown in FIG. 3 . The traffic that occurs in the IP-based packet service basically includes information such as a CP/UDP header, an IP header, a MAC header, and a cyclic redundancy check (CRC), and a length of the information is 400 bits or more. Generally, the size of the uplink traffic is concentrated in a range between 480 bits and 4800 bits in an array of the block size shown in FIG. 3 .
As described above, since the block size of the uplink traffic that the subscriber station is to transmit is concentrated in a range between 960 bits and 4800 bits, the subscriber station requests bandwidth allocation according to the bandwidth request code based on each of the block sizes. Therefore, as shown in FIG. 3 , the bandwidth request codes are divided into N code groups, and the code groups are mapped to the corresponding block sizes. The block sizes in a range of 48 bits to 480 bits are mainly used for MAC control messages other than the uplink traffic, so that the block sizes are mapped to a code group G 0 .
Since the block sizes of the uplink traffic are mostly concentrated in a range between 480 bits and 4800 bits, the block sizes in a range between 960 bits and 4800 bits are mapped to code groups G 1 , . . . , GN. The base station broadcasts information on code groups corresponding to the block sizes to all subscriber stations by using an uplink channel descriptor (UCD).
When the uplink traffic occurs, the subscriber station that receives the information on code groups corresponding to the block sizes selects a code group corresponding to the block size of the traffic. Next, the subscriber station selects an arbitrary bandwidth request code in the selected code group and transmits the bandwidth request code to the base station in a competition scheme. The base station allocates uplink resources in a variable manner according to the code group including the received bandwidth request code.
FIG. 4 is a flowchart illustrating a procedure for requesting resources and a procedure of allocating the resources by using BR ranging according to an embodiment of the present invention. Now, the procedure of requesting resources and the procedure of allocating the resources by using the BR ranging according to the embodiment of the present invention are described with reference to FIG. 4 .
Firstly, the base station broadcasts the UCD including the information on the code group to the subscriber station (S 410 ). At this time, the base station also transmits a UL-MAP.
Next, when there is traffic that is to be transmitted through the uplink, the subscriber station selects the code group corresponding to a block size of the to-be-transmitted traffic (S 430 ). The subscriber station selects an arbitrary bandwidth request code in the selected code group (S 440 ). The subscriber station transmits the selected bandwidth request code to the base station (S 450 ).
The base station determines the code group including the received bandwidth request code (S 460 ). The base station allocates a bandwidth corresponding to the code group to the subscriber station (S 470 ).
Next, the subscriber station transmits the traffic through the bandwidth allocated by the base station.
The method of allocating the bandwidth to the subscriber station by the base station based on the code group including the bandwidth request code transmitted from the subscriber station and the method of transmitting the traffic through the bandwidth allocated from the base station by the subscriber station are classified into three types, which are described later in detail.
FIG. 5 is a view illustrating a BR ranging procedure in a case where the size of uplink traffic is 480 bits or less according to an embodiment of the present invention. Now, the BR ranging procedure in a case where the size of uplink traffic is 480 bits or less according to the embodiment of the present invention is described with reference to FIG. 5 .
Firstly, in a case where the size of the to-be-transmitted uplink traffic is 480 bits or less, since the traffic is mainly an MAC control message which is not sensitive to a delay, the subscriber station selects an arbitrary bandwidth request code in the code group G 0 (S 510 ) and, after that, transmits the bandwidth request code to the base station (S 513 ).
Next, the base station determines which code group the received bandwidth request code is included in (S 520 ). In a case where the received bandwidth request code is determined to be included in the code group G 0 , the base station allocates uplink resources to the subscriber station so that the subscriber station can transmit a BR header (S 530 ). The base station transmits the allocated uplink resources to the subscriber station (S 530 ).
The subscriber station transmits to the base station the BR header indicating information on resources required for uplink traffic transmission by using the uplink resources allocated by the base station (S 540 ).
Next, the base station allocates to the subscriber station the uplink resources corresponding to the information on the resources that the subscriber station requires (S 550 ). The subscriber station transmits the uplink traffic to the base station (S 560 ).
FIG. 6 is a view illustrating a BR ranging procedure in a case where the size of to-be-transmitted uplink traffic is in a range of 480 bits to 4800 bits according to an embodiment of the present invention. Now, the BR ranging procedure in a case where the size of the uplink traffic is in a range of 480 bits to 4800 bits according to the embodiment of the present invention is described with reference to FIG. 6 .
As shown in FIG. 6 , in a case where the size of the to-be-transmitted uplink traffic is in a range of 480 bits to 4800 bits, the subscriber station selects an arbitrary bandwidth request code corresponding to the block size that is the largest one among the block sizes larger than the size of the traffic in the code groups G 1 , . . . , GN (S 610 ). The subscriber station transmits the bandwidth request code to the base station (S 613 ).
When the received bandwidth request code is determined to be included in one of the code groups G 1 , . . . , GN (S 620 ), the base station allocates the uplink resources corresponding to the block size corresponding to the code group (S 630 ) to the subscriber station. The base station transmits CDMA_Allocation_IE of the UL-MAP including a frame number of the received BR code, subchannel information, received BR code number information, and bandwidth allocation information to all the subscriber stations (S 633 ).
Next, the subscriber station determines whether or not the CDMA_Allocation_IE of the UL-MAP is equal to the information that the subscriber station transmits (S 640 ). If the CDMA_Allocation_IE of the UL-MAP is determined to be equal to the information, the subscriber station transmits the traffic by using the uplink resources allocated by the base station (S 650 ).
Accordingly, a delay taken for the subscriber station to transmit the uplink traffic from the time of transmitting the bandwidth allocation code to the time of being allocated with the resources can be reduced from 9 frames to 5 frames.
FIG. 7 is a view illustrating a BR ranging procedure in a case where the size of uplink traffic is 4800 bits or more according to an embodiment of the present invention. Now, the BR ranging procedure in a case where the size of the uplink traffic is 4800 bits or more according to the embodiment of the present invention is described with reference to FIG. 7 .
As shown in FIG. 7 , in a case where a size of the to-be-transmitted uplink traffic is 4800 bits or more, the subscriber station transmits segmented traffic.
Firstly, the subscriber station segments the uplink traffic so as to be suitable for the 4800 bits (S 710 ). The subscriber station selects an arbitrary BR code in the code group GN corresponding to the 4800 bits (S 720 ) and transmits the BR code (S 723 ).
Next, the base station determines the code group including the received BR code (S 730 ). If the code group including the BR code is in a range of the code group G 1 to code group GN, the base station allocates 4800-bit uplink resources corresponding to the code group including the received BR code (S 740 ). The base station broadcasts the CDMA_Allocation_IE of the UL-MAP including the allocation information (S 743 ) to all subscriber stations.
Next, the subscriber station adds a grant management (GM) subheader to the segmented uplink traffic that is segmented so as to be suitable for the allocated resources and transmits the segmented uplink traffic together with the GM subheader to the base station (S 750 ). The GM subheader includes additional resource request information.
Next, when the segmented uplink traffic and the GM subheader are received from the subscriber station, the base station allocates the additional resources that are requested through the GM subheader (S 760 ) to the UL-MAP and transmits the additional resources to the subscriber station (S 763 ).
Next, the subscriber station transmits remaining traffic by using the additional resources allocated by the base station (S 770 ).
Accordingly, since the subscriber station can transmit the segmented traffic, it is possible to transmit a large size of traffic without an additional delay.
Exemplary embodiments of the present invention can be implemented not only through the aforementioned method and/or apparatus but also through computer programs executing functions in association with the structures of the exemplary embodiments of the present invention or through a computer readable recording medium having embodied thereon the computer programs. The present invention can be easily implemented by those skilled in the art by using the above descriptions according to the exemplary embodiments.
Although the exemplary embodiments and the modified examples of the present invention have been described, the present invention is not limited to the embodiments and examples, but may be modified in various forms without departing from the scope of the appended claims, the detailed description, and the accompanying drawings of the present invention. Therefore, it is natural that such modifications belong to the scope of the present invention.
According to the present invention, bandwidth request codes are divided into code groups of which bandwidth request codes represent specific block sizes, and a base station that receives the bandwidth request code allocates uplink resources corresponding to the bandwidth request code, so that it is possible to decrease a transmission delay of the uplink traffic.
In addition, due to a decrease in the transmission delay of the uplink traffic, it is possible to prevent a decrease in a downlink traffic transmission speed that may be caused by a transmission delay of an uplink ACK in a TCP-based Internet service.
While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
|
A method of requesting resources, a method of allocating resources, and an apparatus therefor by using bandwidth request ranging in a mobile communication system are provided. The method of allocating uplink resources to a subscriber station by using bandwidth request ranging in a mobile communication system includes: transmitting an uplink channel descriptor (UCD) including code group information to the subscriber station, wherein the code group information is obtained by dividing a bandwidth request code into a plurality of groups and mapping the groups to predetermined data block sizes; receiving a bandwidth request code selected in the subscriber station; determining a code group including the selected bandwidth request code; and allocating a bandwidth through which a data block size corresponding to the determined code group can be transmitted, to the subscriber station. Accordingly, bandwidth request codes are divided into code groups of which bandwidth request codes represent specific block sizes, and the base station that receives the bandwidth request code allocates uplink resources corresponding to the bandwidth request code, so that it is possible to decrease a transmission delay of the uplink traffic.
| 7
|
RELATED APPLICATIONS
[0001] This application claims priority to, and the benefit of, U.S. Provisional Application Ser. No. 61/317,354, filed Mar. 25, 2010, for all subject matter common to both applications, and claims priority to, and the benefit of, U.S. Non-Provisional Application Ser. No. 13/071,610, filed Mar. 25, 2011 also entitled System and Method for Providing Visual Job Information and Job Seeker's Information, naming Young Jea Shin as the inventor, all of which are incorporated herein by reference. This application also claims priority to, and the benefit of, U.S. Non-provisional application Ser. No. 13/551,404, filed Jul. 17, 2012 also entitled System and Method for Providing Visual Job Information and Job Seeker's Information, naming Young Jea Shin as the inventor, all of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present disclosure relates to an automated process and associated computerized system for improving the recruitment process of qualified candidates for opened positions of different job postings, the process and system includes a platform for transforming information into a video posting displaying human and written video highlights based on the information, and more particularly to an online platform which includes multiple different functions, which includes uploading a text job opening and receiving a encoded video to imbed in internet sites where job seekers can access the posting, offering a more cost efficient alternative for a semi-manual job reports generation, and the automated process of generating a post-response candidate expectation video and support information.
BACKGROUND OF THE INVENTION
[0003] The present application relates to multiple integrated tools to improve the job application process including a system and method for providing job information to job seekers in a visual or video format and/or job seekers' information to employers in a visual or video forma, offering a more cost efficient alternative for a semi-manual job reports generation, and the automated process of generating a post-response candidate expectation video and support information.
[0004] The same way trading, bartering, or employment has been around as long as our culture has existed, recruitment has also been used to match job seekers with employers. For a very long time, employment was mostly a word-to-mouth process where only known people were hired. Small businesses would organically grow by merging in family members or friends of family members. As our culture grew, so did the need for employment. Then came the invention of paper, and this medium defined the next centuries of job searching. In the conventional recruitment systems, employers post job information on the job board in a text-based format. The job seekers who apply for the job submit their resume and other information in a text-based format.
[0005] Many corporations have an ongoing flow of job openings to be filled by candidates and require an automated and simplified process for managing these job openings. Further, these corporations desire to reach a wider audience of potential job seekers and receive a larger proportion of well qualified and highly motivated applicants.
[0006] As each job opening differs and the unique and necessary qualifications for each posting differ, it may be difficult for potential applicants to distinguish certain requirements that are essential to the opening from other requirements that are used to give a profile of what may be a good applicant.
[0007] In the pre-internet era, employers used newspapers ads to post new openings. A human resource manager would make an executive decision as to the publication in different newspapers, covering different geographical areas, and this manager would also decide the size of the posting and the font size for each requirement. Job seekers by looking at the ad and the newspaper reputation would get some type of information as to which requirement will be strictly observed, and which will generally be useful to get a position. Other types of venues for job postings included small job related publications, and local television channels offering wanted ad services. In each case the distribution of the job offer was limited in its potential to reach qualified candidates and distinguish between the essential job requirements from secondary job requirements.
[0008] Today with the arrival of the internet and other types of online or wireless communications, job seekers are bombarded with text-based job descriptions. In this fluid format of information, it may be very difficult to distinguish between essential job requirements and secondary job requirements. It is also difficult to distinguish between important ads posted by employers and less important ads as these may be posted side by side on a board or list.
[0009] What is needed is a new and cost efficient system and process for facilitating the transfer of information between potential employers and job seekers and increasing the number of qualified applicants for any given job opening.
[0010] In the field of broadcast, publishing, and media edition, the authorship of a book, a pilot, or even a video clip created using any automated system is only the first part of the process. Even the best book, may fail unless it reaches the intended audience and is distributed to an audience in such a way and time as to achieve the desired result. What is desired are improvements associated with a system for providing visual or video format information to potential job seekers.
[0011] There are many other chronic problems and frustrations associated with the process of recruitment. From a legislative risk standpoint, employers must guard themselves from bias. Employees in charge of hiring could sometimes be left to make personal decisions instead of decisions for the good of the employer as a whole. Second, improving a process to include an applicant's appearance as part of the pre-selection process may result in prejudicial bias. Third, the most desire employees looking for work may have more alternatives and failure to move quickly to meet their demands will result in these individuals accepting other less desirable jobs. Fourth, a job applicant unaware of the internal processes of a corporation, may wrongfully perceives internal delays or deadlines as a lack of interest. Further, as part of the process, a potential job applicant may get the wrong messages sent by intermediaries who see the potential job applicant as a potential competitor. For these reasons, a new system is needed which resolves these problems at a minimum cost.
BRIEF SUMMARY OF THE INVENTION
[0012] An exemplary embodiment of the present application is a multimedia recruitment system for delivering job and career opportunity information in a visual or video format to potential job seekers. The exemplary embodiment automatically converts text-based job descriptions provided by employers and/or recruiters relating job openings, into a high quality visual or video representations (“Job Reports”).
[0013] The Job Reports are then distributed to job seekers through a plurality of media including for example television (“TV”) channels or networks, on-line communication networks, wireless networks, etc. The exemplary embodiment provides a new recruitment system that brings the power of video and the convergence of media to the employers as well as to the job seekers.
[0014] An exemplary embodiment may provide job seekers or job candidates' information in a visual or video format. Unlike the conventional text-based resume, the exemplary embodiment may generate visual or video representations (“Video Introductions”) of the job seekers or job candidates' information. The exemplary embodiment may enable the job seekers or job candidates to submit their Video Introductions to employers through TV channels or networks, on-line communication networks, wireless networks, etc. The employers can reduce a screening process using the Video Introduction.
[0015] In another exemplary embodiment, the system designed to create Job Reports also allows for administrators to use the platform to broadcast widely the information to customized client web pages, a basic web portal managed by the system, external pages found on different external web pages such as social web sites, and to web pages of partners also engaged in distribution of related content. The system also allows for client customization of client web pages, distribution to external web pages of the choosing of the client, and to any other web page.
[0016] Furthermore, it has been found that while the generation of a Job Report linked with a job opening is always very highly useful, some employers to further accelerate the process and reduce costs will opt for an intermediary version of the Job Report called a Montage Video. This intermediary solution relies on the same technology with the exception of an on-air talent replaced by other video footage and a voice-over.
[0017] In another embodiment, either the Job report or the Montage Video can be produced in conjunction with an Expectation Video. This latest video utilizes a portion of the information used in the Job Report and/or the Montage Video and places post-submission context to the applicant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a screen shot of a frame from a Job Report in an exemplary embodiment.
[0019] FIG. 2 is a screen shot of an exemplary contact information page displayed at the end of the exemplary Job Report as shown at FIG. 1 .
[0020] FIG. 3 is a screen shot of a different frame from the Job Report shown at FIG. 1 in which an on-air talent interviews a company executive or a recruiter to deliver job information and/or company information.
[0021] FIG. 4 is a flow chart showing the interactions between an employer and a multimedia recruitment system used as part of the recruitment system to generate the Job Report shown at FIG. 1 in an exemplary embodiment.
[0022] FIG. 5 is a diagram showing how the a script and the graphic form are input to a teleprompter and a character generator as part of the multimedia recruitment system.
[0023] FIG. 6 is a diagram of portions of the multimedia recruitment system shown at FIG. 4 used to generate a Job Report as shown at FIG. 1 in an exemplary embodiment.
[0024] FIG. 7 is a diagram showing the distribution of the Job Report of FIG. 1 to TV channels in an exemplary embodiment.
[0025] FIG. 8 is a diagram showing the distribution of the Job Report of FIG. 1 in a Job Video .FLV format and ultimately posted on an exemplary website in an exemplary embodiment.
[0026] FIG. 9 is a diagram showing the distribution of the Job Report of FIG. 1 is posted on a mobile friendly website in an exemplary embodiment.
[0027] FIG. 10A is a flow chart showing production of a Video Introduction in an exemplary embodiment.
[0028] FIG. 10B is a block diagram showing the server side application and the client side application running on the multimedia recruitment system and the job seeker's device, respectively, in an exemplary embodiment.
[0029] FIG. 10C shows an interaction between the server side application and the client side application during the production of a Video Introduction in an exemplary embodiment.
[0030] FIGS. 10D-10F are screen shots of the user interfaces provided by the client side application running on the job seeker's device in an exemplary embodiment.
[0031] FIG. 11 is an exemplary network environment suitable for implementing a recruitment system for generating a Job Report as shown at FIG. 1 .
[0032] FIG. 12 depicts a computing device suitable for practicing the recruitment system for generating a Job Report in a network environment.
[0033] FIG. 13 is a diagram associated with the input by an administrator on the system and platform for generating a Job Report to publish and distribute content to several external sources.
[0034] FIG. 14 is a diagram associated with the input by a client on the system and platform for generating a Job Report to customize web pages where content is distributed and published.
[0035] FIG. 15 is a sub-diagram of the process shown at FIG. 14 that describes particulars associated with the management of client pages with distributed content.
[0036] FIG. 16 is also a sub-diagram of the process shown at FIG. 14 that describes particulars associated with the management of other external distribution centers of the content generated by the system and platform.
[0037] FIG. 17 is also a sub-diagram of the process shown at FIG. 14 that describes the specific of XML data creation and publication
[0038] FIG. 18 is an illustration showing the different portions of a Job Report Information Form according to one embodiment of the present invention.
[0039] FIG. 19 is a diagram representing the different elements of the system to generate a Montage Video as a Job Report according to an embodiment of the present invention.
[0040] FIG. 20 is a diagram representing the different steps of generating a Montage Video as part of a production of a Job Report.
[0041] FIG. 21 is a diagram representing the process of providing multiple employer videos to enhance the probabilities of a Job Seeker being selected by the employer.
[0042] FIG. 22 is a diagram representing the of optimizing the process of hiring of a job seeker using a system for generating a plurality of videos related to the employment of the job seeker.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The Significance of The Invention
[0044] Recent case law has clarified the fact that new inventions, which are worthy of protection under the Patent Act must be more than simply a technical upgrade from one existing technology to a new technology. All inventions are worthy of protection as long as they are not simply applying improved efficiency to existing ideas. At the heart of this invention is a significant improvement which is much broader than simply applying audio-visual tools to another area. At the heart of inventions is an “Eureka” moment of inventiveness which must be proven to have happened independently of technical evolution of science.
[0045] The ultimate application of the use of audio-visual power to the area of job search is the show Celebrity Apprentice® on NBC®. This show, invented by Mark Burnett in 2004. In this reality show, one CEO uses hours of footage and multiple tasks to help select an employee. As part of the weekly process, a set of 18 candidates are matched and each week one is eliminated until one remains. This process is long and costly. As part of the earlier versions of the show, the job function were given very broadly (e.g. “you will be my apprentice working on this building”) along with a very simple description of the salary (e.g. “you will be paid at least $250,000 per year”). Because of the popularity of this show, other programs also offer live competitions for employment. In each case, one individual is hired under rather strange conditions. One trap of hindsight is to think that because audio-visual tools allow for these live shows to take place, that extrapolation suggests that simpler systems would also be simple to implement. That is not the case.
[0046] We all know that after decades of producing popular comic books, the popularity of Marvel® movies has recently exploded. We all understand that taking a written story and producing a movie is completely different than producing a comic book. We also all understand that an invention which would automate part of the process and take an author's story and instead of producing a comic book or a movie would produce some hybrid intermediary would be novel and non-obvious. The same can be said in the process of hiring of individuals. The suggestion that any new system which helps manage and expedite generation would be a natural consequence of technology is wrong
[0047] To understand the fact that the invention is not a simple normal growth from known technology, one must look at the time of this invention. The earliest priority date is 2010, more than two decades after the arrival of network news and of the internet as a whole. From the period of 1990 to 2010, the different audio-visual content providers owned computers and cameras and were able to interface with remote users, yet, during this period and still mostly today, the paper/text method of recruitment is generally in use. Many large employers with hundreds of job postings have been unable to reach this technology because it relies on more than simply the extrapolation of tools to a new field.
[0048] General Description
[0049] As shown, this invention relates at least in part to a multimedia recruitment system for providing and transforming job related information in a visual or video format and for generating a visual or video representation of this information in what is referred to as a Job Report. A text-based job description is received from an employer and/or a recruiter and in turn this description is used to generate a visual or video representation of associated with the job description.
[0050] The invention provides a multimedia recruitment system for providing to a job seeker or a job candidate information in a visual or video format relating to a job opening. In addition, the multimedia recruitment system also provides to the job seeker or the job candidate a tool for generating a visual or video representation of the job seeker or job candidate's information back as a response to the Job Report. The visual or video representation of the job seeker or the job candidate with personal information sufficient to answer the job opening is referred to as a Video Introduction.
[0051] The visual or video format or representation may include at least a series of image or picture frames for a predetermined time period or duration. The visual or video representation may be provided in a wide range of video formats, which use different COmpressors-DECcompressorS (CODECS) to encode and compress video data. The possible contemplated video formats include, but are not limited to, .3GP (3GPP Multimedia File), .FLV (Flash Video File), .MPG (MPEG Video File), .WMV (Windows Media Video File). The visual or video representation may also include an audio stream of data.
[0052] In addition to a Job Report linked with a job opening, what is also contemplated is a platform and system which can also generate an intermediary version of the Job Report called a Montage Video. This intermediary solution relies on the same technology with the exception of an on-air talent replaced by other video footage such as B-Roll, animations from an employer website, screen shots, mounted over a voice-over version of the same script.
[0053] The Job Report or the Montage Video can be produced alone or in conjunction with an Expectation Video. This latest video utilizes a portion of the information used in the Job Report and/or the Montage Video and enhances the information with post-submission context to the job seeker to allow the process to attract and retain the best applicant by making the employer more attractive. In some embodiments, the Expectation Video is used as part of the input information for a Job Report and/or a Montage Video, in other embodiments, the Expectation Video is generated from input information from the Job Report or the Montage Video.
[0054] Description of the Job Report
[0055] FIG. 1 is a screen shot of one of the frames of an exemplary Job Report. The invention generates for example a Job Report that is specific and customized to an individual job opening. The Job Report may have a predetermined fixed length of time or a variable length of time depending on the job description provided by an employer. For example, the Job Report may be 30 seconds in length. In the Job Report, the job description may be as shown partly delivered by an on-air talent 110 in a network news style. While one type of delivery is shown, one of ordinary skill in the art will appreciate that other types of delivery styles aside from the network news style may be used. For example, a delivery may include the Montage Video style described below.
[0056] The on-air talent 110 may first introduce a job listing while relevant position information is displayed as shown at 120 , 130 on the side and/or bottom of the screen as shown. The Job Report may contain the employer or company's logo 140 and key statistics about the company and the job positions available. In the background, as shown, the logo of a third party offering services associated with the production of Job Reports (i.e. JSTN) may be displayed in the back, on the relevant positions 120 , 130 .
[0057] The Job Report as shown at FIG. 1 may include several graphic areas 120 and 130 displayed at different portions of the screen. In the example shown at FIG. 1 , one of the two graphic areas is located on left side of the screen, and the second graphic area is located on the bottom of the screen. The first graphic area 120 may be provided at the left upper corner of the screen. The graphic area may display information such as an employer's name, a job title for the position, a job location for the position, a job type, a required experience/education level and a unique job number.
[0058] The second graphic area 130 as shown may be provided at the bottom area of the screen. In the second graphic area 130 , different information may be displayed in sequence or even scrolled as for stock or live news tickers. For example, an employer information may be displayed next to other important information 130 . This information may include benefit information, the responsibilities of the position, and then the qualifications of the position. This area 130 may include a single or a plurality of lines for the display the this information. As shown, the second graphic includes three lines each with up to 45 characters. The employer's logo 140 may be displayed in the second graphic area. While one possible configuration of information display is shown, what is contemplated is the use of any known techniques to display as an overlay over an anchor the information.
[0059] FIG. 2 illustrates a screen shot of a job and contact information page generally reserved for the end portion of the Job Report. On FIG. 2 , at the top of the screen, an employer name, an employer's logo and a job title is be displayed. At the bottom of the screen, the employer's contact information, a job identification number and a disclaimer is displayed. Once again, as shown the logo of a third party service provider may be imbedded within these images to help give every Job Report describing jobs from a large number of different potential employers an overall look and feel. While one possible display of information is shown, what is contemplated is the display of information in any number of configurations.
[0060] FIG. 3 shows a screen shot of an exemplary Job Report from a different camera angle in which an on-air talent 110 interviews a company executive or a recruiter to help deliver some of the company information. During the interview, the company logo may be displayed on the background of the Job Report or it may be placed in different areas around the display area. While FIG. 3 shows one possible different camera angle or method of display of the information using external actors or other sources of information, what is contemplated is the use of any incrustation of video, or information in any format known in the news industry. In addition to inputting the graphic form into the character generator, the second video includes information selected from a group consisting of a film of an external actor, incrustation of a video, information from the news industry.
[0061] The Production of a Job Report
[0062] FIG. 4 is a flow chart showing the interactions between an employer 410 who must fill a job vacancy and the multimedia recruitment system shown here as a platform 420 to produce a Job Report as shown at FIG. 1 . An employer provides a text-based job description 430 , an in an alternate embodiment, the employer uploads the text-based job description 430 using a pre-populated form in a text editor format and more precisely using an online web form. The multimedia recruitment system 420 can also generate a script 440 for the on-air talent 110 to read out loud using a teleprompter 520 as shown at FIG. 5 and to be incorporated as part of the Job Report shown at FIG. 1 . The script 440 is then sent in some embodiments back to the employer 410 for approval (as illustrated by the arrow). As illustrated at FIG. 4 in a page drawn with the label ‘script example,’ the script 440 is text to be read out loud by one or several actors as part of the Job Report.
[0063] At the same time, the multimedia recruitment system 420 may generate and send graphic forms 450 directly for processing as shown at FIG. 5 or for the employer 410 to fill out. The graphic forms 450 are text to be displayed on the screen of the Job Report as discussed above with reference to FIG. 1 . After the employer 410 approves the script 440 and alternatively also fills out the graphic form 450 if one is generated, the employer 410 returns the script 440 and the graphic form 450 to the multimedia recruitment system. These exchanges of information between the employer 410 and the platform 420 also the recruitment system for generating a Job Report are designed to be optimized and minimized in size and volume. Employers 410 often look for many closely related candidates and the different scripts 440 and graphic forms 450 will be closely related as the text job opening 430 will also be extremely similar (e.g. two engineers may have only the level of experience different). By using forms and validation steps as part of this process, the employer 410 and the platform 420 can be programmed to generate the different intermediate documents 430 , 440 and 450 in less time and effort.
[0064] FIG. 5 is a diagram showing how the script 440 from FIG. 4 is input to the teleprompter 520 to be read out-loud by the talent 110 as shown at FIG. 1 . The graphic forms 450 are in turn input to a character generator 510 in the multimedia recruitment system as shown at FIG. 4 . The multimedia recruitment system 420 may include the character generator 510 and the teleprompter 520 . FIG. 5 shows how once the employer 420 has approved both the script 440 and the graphic form 450 , the employer 410 can provide the script 440 and the graphic form 450 to the platform 420 also described as the multimedia recruitment system and both of these documents are in turn sent to two elements 510 and 520 that can also be considered part of the platform 420 that are useful external tools to generate the Job Report. In an alternate embodiment, the character generator and the teleprompter 510 , 520 are internal to the multimedia recruitment system but external to the platform 420 .
[0065] FIG. 6 is a diagram of an exemplary multimedia recruitment system that generates a Job Report with a third portion of the entire process illustrated in full by FIGS. 4-6 . When the multimedia recruitment system 420 produces a Job Report, the multimedia recruitment system feeds the graphic information from the character generator and the script to a teleprompter while taping. The Job Report with graphic areas and the Job Report without graphic areas are recorded in the video tape recorders as well as captured in the Quicktime video format, which is known as .MOV file. The .MOV files are stored in the Storage Area Network (SAN) 610 . The video clips with graphic areas are edited in the editing system 620 to produce a predetermined length of a Job Report 630 .
[0066] What is described is a recruitment system 420 for generating a Job Report as shown in FIG. 1 in a network environment as described in FIG. 11 . The recruitment system 420 includes a server 1150 as shown at FIG. 11 to house the recruitment system 420 coupled as shown to a plurality of job seeker devices 1120 , 1130 , and 1170 and at least an employer device 1140 via a communication network 1110 .
[0067] In the system 420 , an employer 410 uploads using the employer device 1140 a text-based job description 430 relating to a job opening to the server 1150 via the communication network link 1110 between the employer device and the server (shown by lines between the units). The server 1150 includes a multimedia requirement system 1160 also shown as 1200 for the production of a Job Report produced by transforming the text-based job description 430 using a platform 420 into a script 440 and a graphic form 450 by inputting the script 440 into a teleprompter 520 to be read by an on air talent 110 and recorded using a camera (not shown) as a first video. Further, the system 420 produces the Job Report as shown at FIG. 1 by inputting the graphic form 450 into a character generator 510 for producing a second video and by storing the first and second videos in a storage area network 610 as shown at FIG. 6 .
[0068] Finally, the system 420 also allows for editing the first and second videos using an editing suite 620 to produce with both the first and second videos the Job Report as shown at FIG. 1 . The Job Report as shown at FIG. 11 can be viewed by at least a job seeker using one of the plurality of job seeker devices 1120 , 1130 , and 1170 over the communication network 1110 from the server 1150 .
[0069] In another embodiment, Job Report is uploaded by the employer 410 using the employer device 1140 from the server 1150 and the Job Report is viewed on a employer website instead of the server 1150 after being uploaded in a video format and merged into an HTML web page.
[0070] What is also contemplated and described is a method for producing a Job Report as shown at FIG. 1 . The method is performed by conducting using the hardware as described above the steps of (a) uploading a text-based job description 430 relating to a job opening in a multimedia requirement system 420 using an employer device 1140 connected to a server 1150 hosting the multimedia requirement system 1160 . The multimedia requirement system 1160 as shown at FIG. 12 can be located in a computing device 1202 with an execution unit 1204 , a memory 1208 , and a network interface 1216 in communication with a storage 1218 .
[0071] The next step is to transform the text-based job description 430 using the platform 420 into a script 440 and a graphic form 450 , and then inputting the script 440 into a teleprompter 520 to be read by an on air talent 110 and recorded using a camera (not shown) as a first video. The next step is the input of the graphic form 450 into a character generator 510 for producing a second video, and finally storing the first and second videos in the storage 610 and editing the first and second videos 620 to produce a Job Report.
[0072] Other possible steps include having at least one of a plurality of job seekers through their own devices uploading the Job Report on a job seeker device 1120 , 1130 , and 1170 connected to the multimedia requirement system 420 . The Job Report can also be viewed using a video streamer from a web-based interface, and using a review step as part of this method.
[0073] Distribution of Job Report
[0074] FIG. 7 is a diagram showing how the Job Report is distributed to those who broadcast the Job Reports via TV channels or networks. Once the Job Report is produced, the multimedia recruitment system prints out the Job Report on the video tapes and distributes the video tapes to dedicated market MSOs (Multiple System Operators), such as Comcast, Time Warner, Cox and Mediacom, etc. The Job Reports are broadcasted via the TV channels or networks. In an embodiment, the Job Report may be distributed using a satellite or an optical fiber.
[0075] FIG. 8 is a diagram showing that the Job Report is posted on a website in an exemplary embodiment. The multimedia recruitment system may transfer each Job Report into a Flash Video File, which is known as .flv files, and send the .flv files to the website to post the Job Report on the website.
[0076] FIG. 9 is a diagram showing that the Job Report is posted on a mobile friendly website in an exemplary embodiment. The multimedia recruitment system may transfer each Job Report into mobile phone video file, which is known as .3gp, to post the Job Report on a mobile friendly site. The Job Report can be viewed on the mobile phone, which can access the mobile friendly site
[0077] Video Introduction Production
[0078] To create a Video Introduction, the job seeker's device, such as a TV set, a computer and a mobile device, may include a camera to generate a video data stream in the job seeker's device.
[0079] FIG. 10A is a flow chart showing the production of a Video Introduction in an exemplary embodiment. As described above, a job seeker may view a Job Report on a job seeker's device connected to the multimedia recruitment system via a network. The multimedia recruitment system may provide the Job Report along with an Apply button for the job seeker to apply for the job described in the Job Report 1000 . When the job seeker presses the Apply button, the multimedia recruitment system may provide an additional button for the Video Introduction option 1002 . When the job seeker selects the Video Introduction option, then the multimedia recruitment system may enable the job seeker to create a Video Introduction through the multimedia recruitment system. To create the Video Introduction, the job seeker may download an application from the multimedia recruitment system 1004 .
[0080] FIG. 10B is a block diagram showing that a client side application 1022 is downloaded from the multimedia recruitment system 1024 and runs on the job seeker's device 1020 . The multimedia recruitment system may be implemented in a server, such as a media server, and include a server side application 1026 . The client side application may communicate with the server side application to establish a channel between the job seeker's device and the multimedia recruitment system for the transmission of video data in real time.
[0081] FIG. 10C shows the communication between the client side application 1030 and the server side application 1038 in an exemplary embodiment. The client side application initiates a connection to the multimedia recruitment system ( 1032 ). If the server side application is ready to receive images or streaming from the client side application, the server side application sends a message that the server is ready. The client side application receives a response from the sever side application and determines whether the connection is established for the transmission of video data 1034 . If the connection fails, the application repeat the above process. If the connection is established, the application transmits the video data in real time as recording of the Video Introduction starts 1036 .
[0082] In order to enable the job seeker to record a Video Introduction, the client side application may provide guidelines for recording the Video Introduction 1006 in FIG. 10A . FIGS. 10D-10F are exemplary user interfaces provided by the client side application in the job seeker's device. The initial user interface shown in FIG. 10D may include image window 1040 , “Start Record” button 1042 , text-based Instruction 1044 , “Time Left” box 1046 and “Recorded Videos” box 1048 . The image window displays the image captured by a camera in the job seeker's device. The text based Instruction may include information on the procedures for the job seeker to create a Video Introduction. For example, the guidelines may include information on the position of the job seeker's face on the image window. The “Time Left” box displays the time left to finish recording the Video Introduction. The “Recorded Videos” box may displays the file name of the Video Introduction recorded. The “Recorded Videos” box may display a plurality of file names when the job seeker records a plurality of Video Introductions.
[0083] *** If the job seeker pushes the “Start Record” button, recording of a Video Introduction may start. The client side application may receive a video stream from the camera and send the video stream or images to the multimedia recruitment system in real time. The multimedia recruitment system manages the video stream and images to create a Video Introduction file and save the Video Introduction file in the multimedia recruitment system or other file storage devices.
[0084] The client side application may receive video data for a predetermined time to create a Video Introduction 1008 in FIG. 10A . FIG. 10E shows an exemplary user interface provided when a Video Introduction is being recorded. The remaining time may be displayed in the “Time Left” box. When the Video Introduction is being created, a file name may be automatically assigned and displayed in the “Recorded Videos” box. A job seeker may stop recording the Video Introduction by pushing “Stop Record” button 1050 . A job seeker may create a plurality of Video Introductions and select one of the plurality of Video Introductions for submission to an employer.
[0085] When a Video Introduction has been created, the job seeker may preview the Video Introduction before submission 1010 in FIG. 10A . FIG. 10F shows an exemplary user interface provided when a Video Introduction has been recorded. The user interface may provide “Replay” button 1060 to preview the Video Introduction. The job seeker can delete the recorded Video Introduction using “x” mark 1062 on the image window. The job seeker may repeat the above operations to create a plurality of Video Introductions until the job seeker is satisfied with one of the Video Introductions. The job seeker may submit a Video Introduction using “Submit” button 1064 . The multimedia recruitment system may submit the Video Introduction to an employer 1012 in FIG. 10A .
[0086] When the job seeker approves the Video Introduction, the application may disconnect from the multimedia recruitment system.
[0087] FIG. 11 is an exemplary network environment 1100 suitable for implementing an exemplary embodiment. Environment 1100 may include a server 1150 coupled to job seeker's devices 1120 , 1130 and 1170 and an employer's device 1140 via a communication network 1110 . A multimedia recruitment system 1160 may be provided in server 1150 . The employer may post information on job openings on a website in multimedia recruitment system 1160 . Using the multimedia recruitment system, the employer is able to post the job opening information in a visual or video format. Job seeker's devices 1120 , 1130 and 1170 may access server 1150 to search job openings posted in multimedia recruitment system 1160 . Server 1150 and multimedia recruitment system 1160 may be managed by the employer or a third party recruiter. Communication network 1110 may include a television network, Internet, intranet, Local Area Network (LAN), Wide Area Network (WAN), Metropolitan Area Network (MAN), wireless communication network, etc.
[0088] FIG. 12 depicts exemplary computing device 1200 suitable for practicing an embodiment. Computing device 1202 may include execution unit 1204 , memory 1208 , keyboard 1210 , pointing device 1212 , network interface 1216 and storage 1218 . Execution unit 1204 may include hardware or software based logic to execute instructions on behalf of computing device 1202 . For example, in one implementation execution units 1204 may include one or more processors, such as a microprocessor. In one implementation, execution unit 1204 may include single or multiple cores 1205 for executing software stored in memory 1208 , or other programs for controlling computing device 1202 . In another implementation, execution unit 1204 may include hardware 1206 , such as a digital signal processor (DSP), a graphics processing unit (GPU), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), etc., on which at least a part of applications can be executed. In another implementation, execution units 1204 may include virtual machine (VM) 1207 for executing the instructions loaded in the memory 1208 . Multiple VMs 1207 may be resident on a single execution unit 1204 .
[0089] Memory 1208 may include a computer system memory or random access memory (RAM), such as dynamic RAM (DRAM), static RAM (SRAM), extended data out RAM (EDO RAM), etc. Memory 1208 may include other types of memory as well, or combinations thereof. Computing device 1202 may include input devices, such as keyboard 1210 and pointing device 1212 (for example, a mouse) for receiving input from a user. A display device 1214 , such as a computer monitor, may be provided. Optionally, keyboard 1210 and pointing device 1212 may be connected to display device 1214 , or a soft keyboard may be implemented by a touchscreen input device. A graphical user interface (GUI) 1215 may be shown on the display device 1214 . Computing device 1202 may include other suitable conventional I/O peripherals. Moreover, computing device 1202 may be any computer system such as a workstation, desktop computer, server, laptop, handheld computer, smartphone, or other form of computing or telecommunications device that is capable of communication and that has access to sufficient processor power and memory capacity to perform the operations described herein.
[0090] Additionally, computing device 1202 may include network interface 1216 to interface to a Local Area Network (LAN), Wide Area Network (WAN) or the Internet through a variety of connections including, but not limited to, standard telephone lines, LAN or WAN links (e.g., T1, T3, 56 kb, X.25), broadband connections (e.g., integrated services digital network (ISDN), Frame Relay, asynchronous transfer mode (ATM), wireless connections (e.g., 802.11), high-speed interconnects (e.g., InfiniBand, gigabit Ethernet, Myrinet) or some combination of any or all of the above. Network interface 1216 may include a built-in network adapter, network interface card, personal computer memory card international association (PCMCIA) network card, card bus network adapter, wireless network adapter, universal serial bus (USB) network adapter, modem or any other device suitable for interfacing computing device 1202 to any type of network capable of communication and performing the operations described herein.
[0091] The storage device 1218 may be, for example, a hard-drive, CD-ROM or DVD, for storing an operating system (OS) and for storing application software programs, such as multimedia recruitment system 1220 . Multimedia recruitment system 1220 may run on any operating system such as any of the versions of the Microsoft® Windows operating systems, the different releases of the Unix and Linux operating systems, any version of the MacOS® operating system for Macintosh computers, any embedded operating system, any real-time operating system, any open source operating system, any proprietary operating system, any operating systems for mobile computing devices, or any other operating system capable of running on the computing device and performing the operations described herein.
[0092] Furthermore, the operating system and multimedia recruitment system 1220 can be run from a bootable CD, such as, for example, KNOPPIX®, a bootable CD for GNU/Linux.
[0093] Multimedia recruitment system 1220 may enable an employer to produce a Job Report 1222 for a job opening. The job seekers may generate a Video Introduction 1224 using the multimedia recruitment system 1220 . The generated Video Introduction 1224 may be submitted to the employer through the multimedia recruitment system 1220 . With the above features, the multimedia recruitment system 1220 may enable the employer and the jobseekers to communicate with each other.
[0094] As shown at FIGS. 13-17 , once the system has produced as described above a Job Report using the multimedia recruitment system for providing and transforming job related information in a visual or video format, the Job Report information is then broadcast and distributed using several means to reach a wider audience and further increase the efficiency of the process.
[0095] The job search process is a time intensive process that ultimately tries to match relevant candidates to the best job offers. Employers desire qualified or over-qualified employees at the lowest salary while job seekers try to optimize their salaries by applying on job postings for which they may be under-qualified. The process of broadcasting different related job openings in any given sector allows for applicants to understand their level of qualification and apply to the right posting. For example, if an employer can find a way to convey to potential applicants the fact that it has the same job opening for operators with 2, 4, and 6 years of experience, and that these jobs are paid $25,000, $27,500 and $30,000 yearly respectively, an applicant with 3 years of experience will be dissuaded from applying on the two of the three job openings.
[0096] To help convey this information, several types of web pages are contemplated that help job seekers get a broader view of the employment offers and situation as offered by a single employer. For example, a home web page can include (a) a search bar with tools for indexing based on job title, skills, keywords, or even geographical location, (b) a rotation of features employers along with their Job Reports, (c) the logo of featured partners for external access, and (d) general menu information like tips, job categories for rapid search, etc. In one embodiment, the element (b) is placed predominantly in the middle of the page in a larger size.
[0097] In a second possible type of web page, an industry specific page or a topic specific page is created where the web page is structured as (a) a search bar with tools for indexing based on job title, skills, and geographical location, (b) a rotation of industry specific or topic specific information, video or Job Reports, (c) the logo of industry specific or topic specific employers, (d) a list of the different main categories of jobs in the industry listed in order of importance and relevance, and (e) Job Reports of currently available jobs within the specific industry. In one embodiment, element (c) is placed alongside (b).
[0098] Several types of employer pages are also contemplated. In a first type, the logo is the logo of a specific employer and instead of a list of different main categories of jobs, what is found is a description and cultural insight of the employer. Then specific Job Reports for all currently available jobs at this specific employer are then listed and any other external information such as cultural insight videos are listed and available for broadcast. In a second type of employer specific page, the page can include small shortcut external icons that direct to Facebook®, Twitter®, LinkedIn®, or other social media websites. These links to external sites direct a user, via a single click to the social portal of the employer where the employer can have already broadcasted the Job Reports. In another embodiment, a large button allows to access all of the job openings of the employer in other formats or other sites outside of the platform. In yet another embodiment, the page the Job Report displayed includes textual information related to the job opening, an “apply now” button, a link to the written job description, and a link to related job openings. What is also contemplated is the creation of pages with the same type of information but where no Job Report is found in the page.
[0099] FIG. 13 illustrates a diagram associated where one of a plurality of N administrators 1301 (to indicate a plurality, the mathematical expression 1 . . . n is used) can access the platform 420 using log-in protocols for the generation of Job Reports. The administrator 1301 is given access to generate information that is relayed out or broadcasted from the platform 420 on many different places on the internet. For example, the platform 420 can be programmed and configured to send information to a main website like the JSTN.COM website 1302 , to social sites associated by the operator of the main website, for example social sites like Facebook®, Twitter®, Linkedln®, or Youtube® to name a few 1303 .
[0100] The update of the different social sites 1303 and possibly partner sites 1304 , for example indeed.com, simplyhired.com, and aggregator.com can be done by having an access to upload information into these sites as an administrator or a user. The publication to these sites are done generally using a coded XML interface or any other software that sends access information, along with the code
[0101] In turn, each of these partner sites 1304 , who already have access and code validation to different social pages 1305 owned by these partner sites 1304 can use the information sent from the platform 420 and relay the information to the social sites 1305 . For example, An administrator of JSTN™ 1301 uses the platform 420 to generate a Job Report relating to a new IT opening. The Job Report can be sent either to the main JSTN.COM website 1302 , also to different social websites owned by JSTN 1303 , or sent to different other websites 1304 ready to publish the job opening in the video format. These partners 1304 can in turn distribute to their own social pages 1305 further increasing the distribution of the pages.
[0102] FIG. 14 describes a relatively similar system of push of content but where a client 1401 is able to access a specific client page via the system platform 420 as a sub address of the main website 1302 such as MYJSTN.COM 1402 . The content of these client pages is described above. The client 1401 is also able to push the content to the Client's page or any other social media site 1403 owned by the client 1401 . While two examples are given, what is contemplated is the distribution to a large number of external locations and sites to better the distribution of the Job Report or any associated data.
[0103] FIG. 15 is a sub-diagram of the process shown at FIG. 14 that describes particulars associated with the management of client pages with distributed content. In this diagram, the system platform 420 includes an Application Programming Interface (API) 1501 that then directs the information to a Controller 1502 that regulates a form editor 1503 to send and customize the Client's pages on MYJSTN.COM 1402 . In a different embodiment shown at FIG. 16 , the form editor 1503 is replaced in the Controller 1502 with a connector 1602 that allows to edit the content to a different format capable of being used by Social sites 1303 or partner websites 1304 .
[0104] FIG. 17 is also a sub-diagram of the process shown at FIG. 14 that describes the specific of XML data creation and publication. A client 1401 will log in 1701 to the platform 420 and then enter into a Job Report Management tool 1702 designed to help create, modify or delete the different Job Reports as described earlier in this document. The Job Report is then stored and/or indexed 1703 in a database. A creator engine capable of generating code for example in the XML format 1704 sends the data to the Connector 1603 as described in FIG. 16 before the XML data is pushed outward for the different social sites 1303 . For example, if Facebook® requires a log in, and will only accept a very unique type of script, then the XML Creator is set up to generate the XML text that can be accepted by the social interface 1303 .
[0105] Another key part of the process includes the use of a Job Report Information Form sent to employers to help with the process of generating the text job opening 430 as shown at FIG. 4 . In one embodiment, the firm is a .pdf format with scroll-down bars to help fill in different fields
[0000]
Field #
Text
Information Type
#1
COMPANY NAME
TEXT
#2
JOB REPORT LANGUAGE
TEXT
#3
SUBSIDIARY STATUS
YES - NO
#4
PARENT NAME
TEXT
#5
LISTING ENTITY
PARENT - SUBSIDIARY
#6
JOB TITLE
TEXT
#7
POSITION TYPE
CHOICE BAR
a. Full time
b. Part time
c. Full and/or Part time
d. Independent Contractor
e. Intern
f. Contract for Hire
#8
JOB CATEGORY
CHOICE BAR
#9
OPENINGS AVAILABLE
CHOICE BAR
a. Single
b. Multiple
#10
CITY/STATE/COUNTRY
TEXT
#11
EXPERIENCE NECESSARY
TEXT
#12
BRIEF JOB DESCRIPTION
TEXT (MAX. LIMIT)
#13
BRIEF RESPONSIBILITIES
TEXT (MAX. LIMIT)
DESCRIPTION
#14
INSIDE COMPANY
THREE BULLET POINTS
FOR VIDEO
INTEGRATION (MAX
LIMIT)
#15
BENEFITS
THREE BULLET POINTS
FOR VIDEO
INTEGRATION (MAX.
LIMIT)
#16
RESPONSIBILITIES
THREE BULLET POINTS
FOR VIDEO
INTEGRATION (MAX.
LIMIT)
#17
QUALIFICATIONS
THREE BULLET POINTS
FOR VIDEO
INTEGRATION (MAX.
LIMIT)
#18
FULL JOB DESCRIPTION
TEXT
#19
JOB APPLY URL
EXAMPLE
SEE FIG. 18
GIVEN
SCRIPT
GENERATED BY
PLATFORM
(#440 FROM FIG. 4)
INTERNAL
USE SHEET
[0106] The illustration at FIG. 18 in an effort to manage the process of generation of a Job Report, an employer 410 described at FIG. 4 will provide a text job opening 420 by filling in #1 to #13 in the table above. In some cases, elements #14 to #19 will be entered internally. The system will generate a script from the information found at #1 to #19 using proprietary technology and the graphic form. Many features of this intake sheet are novel.
[0107] In addition to capturing and automating the process, points #12 to #17 includes a formatting of a maximum number of characters is placed on the data entry. This allows for the generation of the graphic form 450 as shown at FIG. 4 without having to validate the formatting. The use of three bullet points at elements #14 to #17 allows a control of the script format in a default setting to help place the graphic form in the right place. For example, templates can be used to mine the data from the different elements #1 to #19. Generally, all of the fields entered will be used as part of the script created.
[0108] The use of these different elements as shown at FIG. 18 allows for a simple way to populate a video and generate at least the video overlay over the normal script.
[0109] In yet another embodiment, what is contemplated is the use of a simpler version of the Job Report, a video which incorporates most of the elements described above without the need for a prompter and an anchor in a recording. This “Montage Video” is designed from a template-type setup where animation is uploaded, along with other images from either databases (such as for example Youtube® or a corporate site of an employer. The script, instead of being sent to a prompter, is simply read as an audio file layered on an animated presentation. Tools like Photoshop® or After Effect® can serve to generate the Montage Video.
[0110] FIG. 19 illustrate the different computers or databases needed to help generate the Montage Video, the location where the video is done is shown as 420 connected via a network to either the employee station 1130 or the internet where the Montage Video will reside. The visual data, instead of being generated by the service provider can be taken from an Employer 410 or its website or borrowed with license from third party sites and databases 37 .
[0111] FIG. 20 illustrates how a template, for example using PowerPoint® software can be made to include multiple slides to ‘fill’ with data. Each slide page also includes a portion of the script 440 to be read in the audio recording device as the use, a portion of the graphic form and mounted on one or more images from the third party source. Much like the Job Report is generated using the process shown at FIG. 5 , the Montage Video of a Job Report 451 . The data from the employer 410 describing the job function of the job opening 430 is split into a script portion 440 and a graphic form portion 450 . Instead of being simply sent to the character generator 510 and the teleprompter 520 as shown at FIG. 5 , the information is broken into several N segments 441 , 442 , and into several parts A to N 443 , 444 . The data is then merged into a template 445 with the number of pages N needed to contain all of the script 440 and the graphic form 450 .
[0112] The information is then merged into a single software utility and each character is merged into the pages of the template 447 and the voice is then read by a person 449 using each segment 446 associated with the page N. Once images are added 448 to the characters taken from one of multiple places, the information is then merged 451 into a single film format. The film plays like an animation with text and images appearing with different types of fade-in functions like an animation.
[0113] Finally, FIG. 21 illustrates the complete process of hiring a Job Seeker 612 by providing this person with multiple video tools to help enhance the process. The employer has a database 611 or a website portal on which the Job Seeker 612 can use his/her own HTML portal or browser connected to the internet, or use a local station located in a convenient location for the Employer (such as for example a standalone station) to watch either of (a) an employer introduction video 614 , which describes generally the employer, (b) a Job Report or Montage Video 617 which describes generally (as described in greater detail above) a job opening to be answered by the Job Seeker 612 , and (c) a Candidate Expectation Video 623 which is designed to describe the process linked with the hire of the potential candidate.
[0114] The Candidate Expectation Video 623 is designed to describe generally one of multiple different segments 615 of the employer. As shown at FIG. 21 , the employer may have a number O of different business segments. For example, the Employer may have a different hiring process for lateral attorneys, summer associates, and staff attorneys. For each of these groups, a different Candidate Expectation Video 623 may be produced and associated with each of the Job Report or Montage Video 617 created.
[0115] The Candidate Expectation Video 623 is designed to offer visual and written information describing the internal hiring process at the Employer 611 . This allows a potential Job Seeker 612 to set reasonable expectations as to when the Employer 611 will get back to the individual. For example, larger corporations may require three weeks before getting back to the Job Seeker 612 . Failure to inform the Job Seeker 612 of this potential delay may result in the most employable candidates to believe erroneously that the Employer is not interested and will accept other opportunities. The Candidate Expectation Video 623 is produced by using the same technology as described above for either a Job Report or a Montage Video 617 . The principle of offering a Candidate Expectation Video 623 to the Job Seeker 612 .
[0116] As shown at FIG. 21 , a Job Seeker 612 may use an HTML browser to view an employer introduction video 613 , then watch an associated Job Report or Video Montage for a job opening of interest 618 . As described above, the Job Seeker 612 may then generate a Video Introduction responsive to the Job Report or Montage Video 621 . In a subsequent step, the method includes the Job Seeker 612 watching 622 a Candidate Expectation Video 623 available on the Employer Website 611 .
[0117] That is shown is a system for generating a plurality of videos 614 , 615 , and 623 as shown at FIG. 21 or 1120 , 1130 , and 1170 at FIG. 11 related to the employment of a potential job seeker 612 at an employer 1140 at FIG. 11 and for managing the process of employment of the job seeker 612 by the employer 1140 . This recruitment system comprises at least a server 1150 for storing an employer database 611 as shown at FIG. 21 on behalf of an employer with a plurality of job openings 616 accessible by a job seeker 612 via a communication network 1110 as shown at FIG. 11 by a plurality of job seekers 1120 , 1130 , and 1170 each using a job seeker device to allow the plurality of job seekers to engage in the process of employment.
[0118] The system also includes a platform 420 for generating at least a Job Report 630 or a Montage Video 451 as shown at FIG. 20 associated with at least a Job Opening 616 , and at least a Candidate Expectation Video 623 associated with a different segment 615 in which the Job Report or the Montage Video is associated. The system also allows for the upload and storing from the platform 420 to the server 1150 of the Employer Introduction Video 614 , the Job Report or the Montage Video 617 , and the Candidate Expectation Video 623 . The system also allows for the viewing by the job seeker at the job seeker device of the Job Report 618 before generating a Video Introduction 621 at the job seeker devices and uploading the Video Introduction to the server 619 , and where the system allows for the viewing by the job seeker of the Candidate Expectation Video 622 at the job seeker device.
[0119] In another embodiment, the system includes the generation by the platform 420 of the Job Report or Montage Video by an employer upload 430 using an employer device a text-based job description relating to a job opening 616 to the server via the communication network link between the employer device and the server as shown at FIG. 11 , where the server 1150 includes a multimedia requirement system as shown at FIG. 6 for the production of the Job Report or the Montage Video.
[0120] Also described is how the Job Report is produced by transforming the text-based job description using the platform into a script 440 and a graphic form 450 , by inputting the script into a teleprompter to be read by an on air talent as shown at FIG. 6 and recorded using a camera as a first video, and by inputting the graphic form into a character generator also shown at FIG. 6 for producing a second video, by storing the first and second videos in a storage area network, and editing the first and second videos to produce with both the first and second videos the Job Report 630 .
[0121] The Montage Video 451 as shown at FIG. 20 produced by transforming the text-based job description using the platform into the script 440 and the graphic 450 form both broken into several voice text segments 441 , 442 and parts for insertion within a template 445 with multiple pages and by entry of characters 447 for inclusion on the multiple pages, and adding at least an image 448 , and merging a recorded voice of each voice 449 text segments 446 into a Montage Video using the software 451 .
[0122] The generation by the platform of the Candidate Expectation Video as shown at FIG. 21 includes at least information on a different segment of the Employer and an anticipated response time to an uploaded Video Introduction in response to the Job Report or the Montage Video by the Employer.
[0123] As shown at FIG. 21 by the arrows, what is also claimed is a method of optimizing the process of hiring of a job seeker using a system for generating a plurality of videos related to the employment of the job seeker, the method comprising the steps of receiving 651 as shown at FIG. 22 via a network from an employer at a platform a text-based job description associated with at least a job opening where the text-based job description includes at least a field having a maximum character limit and a field having a limited number of bullet points, generating 652 at the platform using the text-based job description at least a Job Report or a Montage Video, where the generation includes sub-steps of generating a script 653 to be read either by an on-air talent in a prompter or to be read by a narrator reading a segment of the script associated with a page of a template, and where the Job Report or Montage Video using 654 as a formatting guideline the maximum character limit or the limited number of bullet point.
[0124] The method then includes the step of generating 655 at the platform using employer information a Candidate Expectation Video including at least information on a segment of the Employer and an anticipated response time to an uploaded Video Introduction in response to the Job Report or the Montage Video and then storing 656 by the platform on a server in an employer database the Job Report or the Montage Video for uploading by a remote job seeker using a job seeker device and allowing 657 the job seeker to view the Job Report or the Montage Video, uploading and storing on the server in the employer database a Video Introduction produced by the job seeker based on the Job Report or the Montage Video, and allowing 658 the job seeker to view the Candidate Expectation Video to receive at least the information on the segment of the employer and the anticipated response time by the employer to the Video Introduction.
[0125] In a further step, what is contemplated is the step of generating at the platform an Employer Introduction Video, and allowing the job seeker to view the Employer Instruction Video before the step of allowing the job seeker to view the Job Report of the Montage Video.
[0126] Exemplary embodiments are described above. It is, however, expressly noted that these exemplary embodiments are not limiting, but rather the intention is that additions and modifications to what is expressly described herein also are included within the scope of the present implementation. Moreover, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations, even if such combinations or permutations are not made express herein, without departing from the spirit and scope of the present implementation.
[0127] Since certain changes may be made without departing from the scope of the present implementation, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative and not in a literal sense. Practitioners of the art will realize that the sequence of steps and architectures depicted in the figures may be altered without departing from the scope of the present implementation and that the illustrations contained herein are singular examples of a multitude of possible depictions of the present implementation.
|
The present disclosure relates to an automated process and associated computerized system for improving the recruitment process of qualified candidates for opened positions of different job postings, the process and system includes a platform for transforming information into a video posting displaying human and written video highlights based on the information, and more particularly to an online platform which includes multiple different functions, which includes uploading a text job opening and receiving a encoded video to imbed in internet sites where job seekers can access the posting, offering a more cost efficient alternative for a semi-manual job reports generation, and the automated process of generating a post-response candidate expectation video and support information.
| 6
|
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. provisional application Ser. No. 60/854,747 filed Oct. 27, 2006.
BACKGROUND
[0002] Whitewater recreationalists are persons in or on a river, rapid, or flowing channel that use the currents and various hydraulic formations for recreation and enjoyment. This grouping of recreationalists is also referred to as “boaters” or “river runners”. There are many different types of whitewater craft that whitewater recreationalists can use to make their way down a river or rapid. An abbreviated list includes:
[0000]
Inflateable kayaks
Open-decked
Rafts
Kayaks
and other craft
Canoes
Closed-decked
Dory or Drift
Personal Inflated
Catarafts
Canoes
Boats
Water Craft (“rubber
duckies”)
Wake boards &
Swimmers with
Surfboards &
Tubes
other small
or without fins,
Riverboards
boards used to
and paddles
assist
swimming
[0003] Whitewater recreationalists include an increasing number of persons with disabilities including paraplegics, the blind, amputees, etc. Organized sports which involve or evolved from recreational whitewater include:
Slalom: A competitive event for canoeing and kayaking where boaters negotiate gates suspended over the river for the fastest time. Freestyle or Rodeo: A competitive event for canoeing and kayaking where boaters perform tricks on a wave, hole, or other hydraulic feature or obstruction. Rafting: An event where rafters race down the river for the fastest time. Down-River or Wildwater kayaking: An event where kayakers race down the river for the fastest time. Squirt Boating: A competitive event where kayakers and canoeists perform tricks utilizing sub-surface current in low volume boats.
[0009] Open Channel Hydraulics is the formalized science that considers the formation of hydraulic formations that are encountered by whitewater recreationalists found in rivers and man-made structures. This includes those features associated with whitewater rapids and features. The basic equations governing whitewater hydraulic formations are the Navier-Stokes equations which are an application of Newton's second law. These can be reduced to simpler forms when considering the free (water) surface found in rivers and channels and the incompressibility of water.
[0010] Whitewater recreationalists refer to various hydraulic formations found in fast-moving rivers, rapids, and channels. These hydraulic formations include “Holes”, “Waves”, and “Hydraulics”. These describe various forms of what is referred to by scientists and engineers as a hydraulic jump. (Note however that waves can be formed by other hydraulic mechanisms.) A hydraulic jump occurs when fast moving flow in a state known as supercritical changes to a slower moving subcritical state. From a scientific point of view, supercritical flow is defined as having a Froude Number greater than one, and subcritical flow is defined as having a Froude Number less than one. The Froude Number is a well defined hydraulic term which is a dimensionless ratio of inertial forces to gravitational forces. The Froude Number is defined as V_√(gd), where V=velocity of the flow, g=gravitational acceleration, and d=characteristic depth.
[0011] The hydraulic jump was studied extensively in the 1950s and 1960s, although hydraulic jump formations involving non-linear channel geometries formations can be quite complex and difficult to analyze or predict—even with computer modeling. Physical structures that can create waves and holes with recreationally desirable attributes have a vertical or steep downward slope in the vicinity where the hydraulic jump occurs. This condition was studied in the 1950s and 1960s and is know as a hydraulic jump at an abrupt drop.
[0012] The abrupt drop can cause the hydraulic jump to stabilize in deeper areas, and create other characteristics that are advantageous to whitewater recreationalists. At an abrupt drop the transition from supercritical to subcritical flow is characterized by several flow patterns depending upon the inflow and conditions found in the downstream pool (tailwater). These flow patterns include (1) the A-jump, (2) the wave jump or W-jump or the wave train, and (3) the B-jump which is characterized by a plunging jet. The characteristics of wave jump and wave train are essentially the same and hereafter the wave jump and wave train will simply be referred to as ‘Wave’
[0013] Holes and waves are often the predominant features treasured by whitewater recreationalists. Holes are more retentive—having tendency to impede the passage of buoyant objects, while waves create exciting changes in elevation. Waves known as “breaking waves” can also have breaking water (whitewater) toward their crest that acts to retain buoyant whitewater craft. The form and type of these hydraulic jumps varies dramatically and even small nuances not noticeable to the untrained eye can affect the desirability to whitewater recreationalists.
[0014] Pools are areas in a river or channel that move slowly (relative to the higher velocity rapids) in the downstream direction. They are typically in a hydraulic state known as subcritical—having a Froude Number less than a value of one. However higher velocity currents or jets can carry through the entire length of a pool. Pools can also have recirculating eddy currents known as “eddies”. Pools are advantageous to whitewater recreationalists for recovery.
[0015] Eddies are formed upstream and downstream of obstructions in a river. Eddies are generally recognized by whitewater recreationalists to occur in a pool adjacent to and downstream of a wave or hole. Eddies are currents that tend to rotate in the horizontal plane. This rotation can usually be seen on the surface of the water. Typically, the flow in an eddy is oriented upstream rather than downstream. An eddy can have slow or mild upstream currents or can be quite violent. The characteristics of an eddy are important to the recreational experience of whitewater recreationalists playing in an adjacent hydraulic jump.
[0016] Structures that create the various formations of the hydraulic jump including waves and holes tend to control and focus flow and/or lower the flow to increase it's velocity and power so that it is supercritical. This requires some type of crest, which usually has elevated portions to form a constriction. The flow in the vicinity of the physical crest—also known as a control section—typically enters a state known as critical depth. Note that at this location, the Froude Number of the flow has a value of one. Downstream of this crest is a ramp where the flow transitions from a critical state to supercritical state prior to entering the hydraulic jump. Note that some structures have an entirely vertical ramp; while in others; there is no clear physical distinction between the crest and the ramp. The ramp is simply where the flow transitions from the critical flow to the hydraulic jump.
[0017] A wave can also be created in situations where a hydraulic jump is not involved. Sometimes known as a wave train or standing waves, these can be created by a perturbation or series of perturbations or “bumps” in the invert of a river or channel. This type of wave, however, is difficult to reliably create or predict and usually occurs through very specific flow rates when found in natural rivers.
[0018] Typically, prior art man made physical structures for producing hydraulic formations have fixed geometries and fixed dimensions. One problem with these fixed physical structures is that they may not produce the desired hydraulic formations at normal or low water flow rates. In addition, at excessively high water flow rates, fixed physical structures may form constrictions, increased floodplains and high water surface elevations.
[0019] It would be advantageous for physical structures for producing hydraulic formations to have an adjustable geometry, which could be used to vary the size and character of the corresponding hydraulic formations over a wide range of water flow rates. It would also be advantageous for physical structures for producing hydraulic formations to be adjustable for constructing a variety of systems for whitewater recreationalists under a variety of conditions.
[0020] Various embodiments of adjustable physical structures to be further described can be used to form hydraulic formations. In addition, the adjustable physical structures can be adjusted to vary the geometry of the hydraulic formations, and can be used over a wide range of flow rates and environmental conditions. Further, the adjustable physical structures can be used to construct various systems including kayak courses, rafting courses, boating courses and theme park rides.
[0021] However, the foregoing examples of the related art and limitations related therewith, are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
SUMMARY
[0022] An adjustable physical structure is configured for placement in a channel containing a flow of water for producing a variety of hydraulic formations beneficial for whitewater recreationalists. The channel can comprise a man made channel, or a natural channel such as a river bed. The adjustable physical structure includes a control structure placed in the channel, and an adjustable lip located downstream of the control structure.
[0023] The control structure can include a crest and a ramp downstream of the crest. The crest constricts and/or elevates (dams) the flow water to increase it's energy and focus the flow of water. The crest can be curved, linear or irregular in both plan and in cross-section. The flow in the vicinity of the crest—also known as a control section—goes through a state known as critical depth. At this location, the Froude Number of the flow of water has a value of one. If present, the ramp routes the flow of the water to the adjustable lip. The ramp can have varying and non-linear slopes and plan configurations. Additionally, the ramp can be static or adjustable to elevate the flow of water and vary the velocity and energy of the supercritical flow as it is passed to the adjustable lip.
[0024] The adjustable lip is configured for placement at a selected position in the flow of water. For example, the adjustable lip can be adjusted vertically to vary the elevation and angle of supercritical flow as it exits the adjustable physical structure and enters a downstream pool where the flow transitions—via a hydraulic jump to subcritical flow. The adjustable lip can also be located downstream of a second adjustable plate(s), perforated plate(s), or series of vanes. The adjustable physical structure can also include an adjustable placement mechanism such as a cylinder, a bladder or a mechanical jack, which can be operated to place the adjustable lip in the selected position.
[0025] An alternate embodiment adjustable invert physical structure comprises a shaped structure configured for placement on the invert of the channel. The adjustable invert physical structure can be moved or adjusted in horizontal and/or vertical directions to shape the flow of water.
[0026] A method for forming hydraulic formations includes the steps of providing a flow of water in a channel; providing an adjustable lip configured for placement in a selected position in the flow of water; forming a drop upstream of the adjustable lip; accelerating the flow of water towards the lip; and adjusting a position of the lip in the flow of water to the selected position.
[0027] A whitewater system includes one or more adjustable physical structures and/or adjustable invert physical structures placed in a channel at desired locations, and configured to form desired hydraulic formations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Exemplary embodiments are illustrated in the referenced figures of the drawings. It is intended that the embodiments and the figures disclosed herein are to be considered illustrative rather than limiting.
[0029] FIG. 1A is a schematic plan view of a system for whitewater recreationalists constructed using adjustable physical structures for producing hydraulic formations;
[0030] FIG. 1B is a schematic plan view of another system for whitewater recreationalists constructed using adjustable physical structures for producing hydraulic formations;
[0031] FIG. 2 is a plan view of an adjustable physical structure for producing hydraulic formations taken along line 2 of FIGS. 1A and 1B ;
[0032] FIG. 2A is a cross sectional view taken along section line 2 A- 2 A of FIG. 2 ;
[0033] FIGS. 2B-2E are plan views of optional wave shaper extensions for the adjustable physical structure of FIG. 2 ;
[0034] FIGS. 2F-2I are end views of the optional wave shaper extensions shown in FIGS. 2B-2E ;
[0035] FIG. 2J is a plan view of an optional lip block wave shaper;
[0036] FIG. 2K is a cross sectional view of the lip block wave shaper of FIG. 2J ;
[0037] FIG. 3 is a plan view of an adjustable through-flow physical structure taken along line 3 of FIGS. 1A and 1B ;
[0038] FIG. 3A is a cross sectional view taken along section line 3 A- 3 A of FIG. 3 showing the adjustable through-flow physical structure in a raised position;
[0039] FIG. 3B is a cross sectional view equivalent to FIG. 3A showing the adjustable through-flow physical structure in a lowered position;
[0040] FIG. 3C is a schematic cross sectional view showing the operation of an adjustable lip of the adjustable through-flow physical structure;
[0041] FIG. 3D is a cross sectional view equivalent to FIG. 3A showing the adjustable through-flow physical structure with an optional cover;
[0042] FIG. 3E is a cross sectional view taken along section line 3 E- 3 E of FIG. 3 showing the adjustable through-flow physical structure along side identical adjustable through-flow physical structure in phantom lines;
[0043] FIG. 4 is a plan view of an adjustable wing wall physical structure taken along line 4 of FIGS. 1A and 1B ;
[0044] FIG. 4A is a cross sectional view taken along section line 4 A- 4 A of FIG. 4 ;
[0045] FIG. 4B is a cross sectional view taken along section line 4 B- 4 B of FIG. 4 ;
[0046] FIG. 5 is a plan view of an adjustable wing wall physical structure taken along line 5 of FIGS. 1A and 1B ;
[0047] FIG. 5A is a cross sectional view taken along section line 5 A- 5 A of FIG. 5 ;
[0048] FIG. 5B is a cross sectional view taken along section line 5 B- 5 B of FIG. 5 ;
[0049] FIG. 6 is a plan view of an adjustable physical structure taken along line 6 of FIGS. 1A and 1B ;
[0050] FIG. 6A is cross sectional view taken along section line 6 A- 6 A of FIG. 6 ;
[0051] FIG. 6B is cross sectional view taken along section line 6 B- 6 B of FIG. 6 ;
[0052] FIG. 7 is a plan view of an adjustable physical structure integrated into the outlet of a conveyance structure such a pump outlet. The section is taken along line 7 of FIGS. 1A and 1B ;
[0053] FIG. 7A is a cross sectional view taken along section line 7 A- 7 A of FIG. 7 ;
[0054] FIG. 7B is a cross sectional view taken along section line 7 B- 7 B of FIG. 7 ;
[0055] FIG. 8 is a plan view of an adjustable physical structure with an expandable or flexible membrane taken along line 8 of FIGS. 1A and 1B ;
[0056] FIG. 8A is a cross sectional view taken along section line 8 A- 8 A of FIG. 8 ;
[0057] FIG. 8B is a cross sectional view taken along section line 8 B- 8 B of FIG. 8 ;
[0058] FIG. 9 is a plan view of an adjustable invert physical structure taken along line 9 of FIGS. 1A and 1B ; and
[0059] FIG. 9A is a cross sectional view taken along section line 9 A- 9 A of FIG. 9 .
DETAILED DESCRIPTION
[0060] Referring to FIG. 1A , a whitewater system 10 - 1 includes various adjustable physical structures 12 A- 12 H which produce various hydraulic formations. By way of example, the whitewater system 10 - 1 can be part of a theme park or other attraction for whitewater recreationalists 11 . The whitewater system 10 - 1 ( FIG. 1A ) includes a man made channel 14 - 1 configured to contain a flow of water 16 in a closed loop as indicated by water flow direction 18 . The whitewater system 10 - 1 ( FIG. 1A ) is sized to allow one or more watercraft 19 , and swimmers as well, to ride on the flow of water 16 through the system 10 - 1 . The whitewater system 10 - 1 ( FIG. 1A ) can also include one or more pumps (not shown) configured to produce the flow of water 16 . A representative depth d of the flow of water 16 in the channel 14 - 1 can be from 4 inches to 10 feet. A representative flow rate of the flow of water 16 in the channel 14 - 1 can be from about 30 cubic feet per second (cfs) to 1000 cubic feet per minute (cfs).
[0061] Referring to FIG. 1B , a whitewater system 10 - 2 containing adjustable physical structures 12 A- 12 H is illustrated. In this embodiment, the channel 14 - 2 can comprise a river bed, and the system 10 - 2 can form a whitewater course such as a slalom course, a kayak course, a rafting course or a boating course.
[0062] Referring to FIGS. 2 and 2A , an adjustable lip physical structure 12 A is illustrated. The adjustable lip physical structure 12 A ( FIGS. 2-2A ) includes a crest 20 A, a ramp 22 A and an adjustable lip 24 A. The crest 20 A and the ramp 22 A form a control section in which the flow of water 16 is focused and increased in energy. The crest 20 ( FIGS. 2-2A ) is formed or placed on the invert 26 A (bottom) of the channel 14 - 1 or 14 - 2 oriented generally vertically, and generally perpendicular to the water flow direction 18 . The crest 20 A ( FIGS. 2-2A ), and the ramp 22 A as well, can be formed of a solid material such as concrete, rock, grouted rock or steel. The crest 20 A ( FIGS. 2-2A ) functions similarly to a dam, and is configured to focus and build up the water to form a hydraulic drop. The hydraulic drop is the difference in elevation between the water surface upstream and the water surface downstream of the adjustable lip physical structure 12 A. The height of the crest 20 A ( FIGS. 2-2A ) will be dependent on the depth d of the water in the channel 14 and the desired power, hydraulic formation, and recreational experience created by the physical structure. A representative depth dl ( FIG. 2 ) of the flow of water 16 above the top of the crest 20 A can be from 0.5 feet to 6 feet. A representative width of the crest 20 A, and the ramp 22 A and adjustable lip 24 A as well, can be from 6 feet to 30 feet.
[0063] The ramp 22 A ( FIGS. 2-2A ) comprises a sloped structure that can be formed continuously with the crest 20 A. The ramp 22 A ( FIGS. 2-2A ) is configured to accelerate the flow of water 16 from the crest 20 A downstream to the adjustable lip 24 A. The ramp also varies the velocity and energy of the flow of water 16 which preferably has a supercritical flow as it contacts the adjustable lip 24 A. As shown in FIG. 2A , the ramp 22 A ( FIGS. 2-2A ) can slope downwardly from the upstream end to the downstream end of the adjustable lip physical structure 12 A. A representative slope of the ramp 22 A ( FIGS. 2-2A ) can be from 0.5 inches per foot to 12 inches per foot. The ramp 22 A can also have a shape which converges the flow of water 16 towards the adjustable lip 24 A, such that a more focused v-shaped hydraulic formation is produced. The ramp 22 A can also have a shape which diverges the flow of water 16 towards the adjustable lip 24 A such that a broader hydraulic formation is produced.
[0064] The adjustable lip 24 A ( FIGS. 2-2A ) comprises a generally l-shaped structure pivotably and adjustably mounted to a base 28 A ( FIG. 2A ). The adjustable lip 24 A is located on a stepped invert 26 A of the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ) having a vertical drop 52 A. The adjustable lip 24 A can be formed of a material such as steel, and can be weighted with a material such as concrete, to resist the large hydraulic forces encountered during operation of the adjustable lip physical structure 12 A. As shown in FIG. 2A , the adjustable lip 24 A can include a vertical member 38 A and a horizontal member 40 A, which can be welded or bolted together. The inside angle between the horizontal member and the vertical member can range from 90 degrees (as shown) to 160 degrees. As shown in FIG. 2 , the adjustable lip 24 A can also include bracing members 42 A, and a pivot support member 44 A which pivotably mounts the adjustable lip 24 A to the base 28 A on bolts, pins or other mechanisms.
[0065] In FIG. 2A , the adjustable lip 24 A is shown in three different positions (Positions 1 - 3 ) in the flow of water 16 . The adjustable lip 24 A can be locked in each of these positions (Positions 1 - 3 ) as well as any position in between. As also shown in FIG. 2A , the position of the adjustable lip 24 A can be selected as required, from a lowered position (Position 1 ) wherein it is located beneath the surface of the ramp 22 A, to a generally horizontal medial position (Position 2 ) wherein it is generally planar with the surface of the ramp 22 A, to a raised position (Position 3 ) wherein it is oriented at a selected height above the surface of the ramp 22 A. In the different positions, the adjustable lip 24 A can be adjusted vertically to vary the elevation and angle of the flow of water 16 (supercritical flow) and enters the tailwater 48 A ( FIG. 2A ) where the flow transitions—via a hydraulic jump to subcritical flow.
[0066] In Position 3 ( FIG. 2A ) the downstream end of the adjustable lip 24 A can be located at a depth of from about 6 inches to 2 feet below the surface 30 A ( FIG. 2A ) of the flow of water 16 . This depth can be selected such that the water craft 19 ( FIG. 1 ) encounter a hydraulic formation 46 that is more retentive (i.e. a hole or A), so that craft are less likely to strike the adjustable lip 24 A. The lip 24 A can have a downward limit so as to reduce the chances of forming a hydraulic formation 46 B. The adjustable lip 24 A can also be oriented at an desired angle relative to the surface of the ramp 22 A or to the surface of the invert 26 A of the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ). For example, the adjustable lip 24 A can be located at an angle of from 130 degrees to 230 degrees relative to the surface of the ramp, or at an angle of from 45 degrees (upward) to 45 degrees (downward) relative the invert 26 A of the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ).
[0067] The base 28 A ( FIG. 2A ) for the adjustable lip 24 A can be formed of a solid material such as concrete, grouted concrete or steel anchored to the invert 26 A ( FIG. 2A ) of the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ). In addition, the base 28 A can include a invert portion 31 A, a vertical portion 33 A and a shaped portion 35 A configured as a support for the placement mechanism 36 A. The adjustable physical structure 12 A ( FIG. 2-2A ) can also include adjustable wing wall structures 12 C, or adjustable wing wall block structures 12 E, configured to control the formation of the hydraulic formation 12 A and resist the tailwater 48 A from collapsing into the lower water surface 30 A above the horizontal member 40 A As will be further explained, the adjustable wing walls 32 A can be formed of interlocking blocks 34 A.
[0068] The adjustable lip physical structure 12 A ( FIGS. 2-2A ) can also include an adjustable placement mechanism 36 A configured to pivot or otherwise move the adjustable lip 24 A to the selected position (e.g., Positions 1 - 3 ). As shown in FIG. 2A , the placement mechanism 36 A can comprise an inflatable bladder, which can be inflated or deflated as required to place the adjustable lip 24 A at the selected position. U.S. Pat. No. 7,114,879 to Obermeyer describes this type of inflatable bladder. With the placement mechanism 36 A formed as an adjustable bladder, the adjustable lip 24 A is preferably weighted to resist the hydraulic forces which tend to force the adjustable lip up and out of the flow of water 16 A. Alternately, the placement mechanism 36 A can comprise a hydraulic cylinder or an adjustable mechanism such as a mechanical jack. In this case the hydraulic cylinder or adjustable mechanism helps to lock the adjustable lip 24 A in the selected position (e.g., Positions 1 - 3 ). The adjustable lip physical structure 12 A ( FIG. 2-2A ) can also include a grate 56 A configured to prevent debris, whitewater recreationalist 11 , and water crafts 19 from getting under the adjustable physical structure or affecting the operation of the adjustable lip 24 A.
[0069] During operation of the adjustable lip physical structure 12 A ( FIGS. 2-2A ), the adjustable lip 24 A can be placed in the selected position (e.g., Positions 1 - 3 ) to form a desired hydraulic formation 46 A ( FIG. 2A ) in the tailwater 48 A ( FIG. 2A ) downstream of the adjustable lip physical structure 12 A. For example, depending on the position of the adjustable lip 24 A, the hydraulic formation 46 A ( FIG. 2A ) can comprise a wave or hole of a selected height and shape. For example, the hydraulic formation 46 A can comprise an A-jump which is characterized by the jump breaking at or upstream of the abrupt drop, (hole or retentive wave) (2) the wave jump or W-jump or the wave train which are characterized by the presents of waves, and (3) the B-jump which is characterized by a plunging jet (hole, or downstream formed wave).
[0070] Referring to FIGS. 2B-2E and FIGS. 2F-2I , optional wave shaper extensions 50 A- 50 D for the adjustable lip physical structure 12 A are illustrated. The wave shaper extensions 50 A- 50 D are configured to vary the shape and character of the hydraulic formations 46 A ( FIG. 2A ). In each embodiment the wave shaper extension 50 A- 50 D bolts or otherwise attaches to the vertical member 38 A of the adjustable lip 24 A. The surface can be in the same plain as the surface of the horizontal element 40 A ( FIG. 2A ) of the adjustable lip 24 A or can be angled upward from 0 degrees to 30 degrees or downward from 0 degrees to 60 degrees.
[0071] In FIG. 2B , a wave shaper extension 50 A has the shape a bell or a hillock with a selected height Ha and a selected width Wa. A representative value for Ha 24 can be from 0.5 feet to 6 feet. A representative value for Wa can be from be from 120 percent to 20 percent of the width of the horizontal element 40 A ( FIG. 2A ) of the adjustable lip In FIG. 2B , a wave shaper extension 50 B has the shape of a paddle with a selected height Hb and a selected width Wb. Representative values for Hb and Wb are the same described for wave shaper extension 50 A. In FIG. 2C , a wave shaper extension 50 C has the shape of a paddle with a selected height Hc and a selected width Wc. Representative values for Hb and Wb are the same described for wave shaper extension 50 A. In FIG. 2D , a wave shaper extension 50 D has the shape of a paddle with a selected height Hd and a selected width Wd. Representative values for Hb and Wb are the same described for wave shaper extension 50 A. Wave shaper extension 50 B is shown oriented with a downward slope in FIG. 2G , but all wave shaper extensions can be sloped upward or downward. The slope of the wave shaper extension can be adjusted with a placement mechanism 37 B to adjust the slope as required. In each embodiment the wave shaper extension 50 A- 50 D can be formed of a durable material such as metal or plastic. In addition, the surface of the wafer shaper extension 50 A- 50 D can be perforated, textured or otherwise shaped to further control the resultant hydraulic formation 46 A- 46 D.
[0072] Referring to FIGS. 2J and 2K , an adjustable lip block physical structure 12 D is illustrated. The adjustable lip block physical structure 12 D performs the objectives similar to the adjustable lip physical structure 12 A ( FIG. 2A ) but without the adjustable lip 24 A ( FIG. 2A ). The adjustable lip block physical structure 12 D includes a crest 20 D and a ramp 22 D substantially similar to the previously described crest 20 ( FIG. 2A ) and ramp 22 ( FIG. 2A ). In addition, the ramp 22 A can also have a shape which converges the flow of water 16 towards the adjustable lip 24 A such that a more focused v-shaped hydraulic formation is produced (shown in FIG. 2J ). The ramp 22 A can also have a shape which diverges the flow of water 16 towards the adjustable lip 24 A such that a broader hydraulic formation is produced. The adjustable lip block physical structure 12 D also includes a base 28 D formed of concrete or other suitable material, and an L-shaped lip block 66 D mounted or “keyed” to the base 28 D. The lip block shown 66 D forms a vertical lip 68 D adjacent to the invert 26 D of the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ) which functions substantially similarly to the previously described adjustable lip 24 A ( FIG. 2A ) to form a desired hydraulic formation 46 D. Various configuration and sizes of lip blocks can be placed into the base 28 D to form different hydraulic formations 46 D. Alternate shapes of lip blocks 66 D includes downward and upward sloping adjustable lip which can slope from 45 degrees downward to 45 degrees upward. Lip blocks can also have a vertical lip 68 D that is higher or lower than the base 28 D. Different lip blocks 66 D can also be used in the same base 28 D to form various hydraulic formations 46 D.
[0073] Referring to FIGS. 3 , 3 A, 3 B, 3 C, 3 D and 3 E, an adjustable through-flow physical structure 12 B is illustrated. As shown in FIGS. 3A and 3B , the adjustable through-flow physical structure 12 B is located on a stepped invert 26 B of the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ) having a vertical drop 52 B. The adjustable through-flow physical structure 12 B includes a crest 20 B and a ramp 22 B which function substantially as previously described. The adjustable through-flow physical structure 12 B also includes a base 28 B, and a through-flow adjustable lip 24 B. The base 28 B can be formed of concrete or other building material placed along the vertical drop 52 B on the invert of the channel 26 B. The adjustable through-flow physical structure 12 B increases the effective flow in the hydraulic formation 12 B and decreases the Froude Number of the flow 16 as it passes over the shaped vanes 58 B or perforations. The adjustable through-flow structure is shown and described as a lip 24 B, however it can also be configured into the ramp 22 B. For instance it could be readily included into the ramp 22 F or 86 G as described below.
[0074] As shown in FIGS. 3A and 3B , the adjustable through-flow physical structure 12 B also includes a plurality of adjustable placement mechanisms 36 B attached to the base 28 B configured to place the adjustable through-flow lip 24 B in a desired position in the flow of water 16 . In FIGS. 3A and 3B , the adjustable through-flow physical structure 12 B is shown in two different positions. In FIG. 3A , the adjustable through-flow lip 24 B is in a “raised” position located in the flow of water 16 above the lowest point of ramp 22 B. In FIG. 3B , the adjustable through-flow lip 24 B is in a “lowered position” located in the flow of water 16 above the lowest point of the ramp 22 B. However, the illustrated positions (“raised” and “lowered”) are merely exemplary, as the adjustable through-flow lip 24 B can be placed in any desired position in the flow of water 16 . By way of example, the adjustable through-flow lip 24 B can be placed from the tailwater surface to 5 feet below the tailwater surface 48 B, at an angle of from 30 degrees upward to 45 degrees downward relative to the invert 26 B of the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ) or tailwater surface 48 B.
[0075] As shown in FIGS. 3A and 3B , the adjustable through-flow physical structure 12 B can also include a linkage plate 54 B which is pivotably attached to the base 28 B and to the adjustable through-flow lip 24 B. The linkage plate 54 B serves as an attachment member for attaching the adjustable through-flow lip 24 B to the base 28 B. If included, the linkage plate 54 B allows adjustment of the vertical elevation of the flow of water 16 as it enters the downstream pool 88 B. The adjustable through-flow physical structure 12 B also includes a grate 56 B attached to the adjustable through-flow lip 24 B and slidably supported by the invert 26 B of the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ). The grate 56 B prevents debris from accumulating in the water proximate to the adjustable through-flow physical structure 12 B and can prevent whitewater recreationalists 11 , and water crafts 19 from getting under or into the adjustable flow-through physical structure 12 B or affecting the operation of the adjustable flow-through lip 24 B.
[0076] As also shown in FIGS. 3A , 3 B and 3 C, the adjustable through-flow lip 24 B can include a plurality of shaped vanes 58 B configured to direct water and allow water to flow freely as indicated by flow arrows 18 B through the adjustable through-flow lip 24 B. In addition, the shaped vanes 58 B ( FIG. 3B ) can have a curved shaped similar to turbine blades, which function to further shape the hydraulic formations 46 B ( FIGS. 3A and 3B ) in the tailwater 48 B ( FIGS. 3A and 3B ) downstream of the adjustable lip physical structure 12 A. For example, depending on the position of the adjustable through-flow lip 24 B, the hydraulic formation 46 B ( FIGS. 3A and 3B ) can comprise a wave substantially as previously described. Alternately, in place of shaped vanes 58 B, the through-flow adjustable lip 24 B can include holes, perforations, channels, slats, flat vanes, or other members that direct and allow water to flow freely through the adjustable flow-through lip 24 B.
[0077] The placement mechanisms 36 B ( FIGS. 3A and 3B ) can comprise adjustable mechanisms such as jacks or hydraulic cylinders which are pivotably attached to the base 28 B and to the through-flow adjustable lip 24 B. The placement mechanism can also be an inflatable bladder as shown in FIG. 2A . As shown in FIGS. 3A and 3B , the placement mechanisms 36 B, in combination with the adjustable through-flow lip 24 B and the linkage plate 54 B, form a four bar linkage that allows the adjustable through-flow lip 24 B to be placed in any desired position, and with any desired orientation relative to the flow of water 18 in the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ).
[0078] FIG. 3D illustrates adjustable wing wall physical structures 12 C in combination with the adjustable through-flow physical structure 12 B. The structure and function of the adjustable wing wall physical structures 12 C will be more fully explained in the paragraphs to follow. FIG. 3E illustrates three adjustable through-flow physical structure 12 B placed in series across the channel 14 - 1 ( FIG. 1A ) or 14 - 2 ( FIG. 1B ).
[0079] Referring to FIGS. 4 , 4 A and 4 B, an adjustable wing wall physical structure 12 C is illustrated. The adjustable wing wall physical structure 12 C is configured to control the formation of the hydraulic formation 46 C and resist the tailwater 48 C from collapsing into the lower water surface 30 above the lip 24 A, 24 B, 24 D, 24 F. For example, the adjustable wing wall physical structure 12 C can be located adjacent to, or in close proximity to, the adjustable through-flow physical structure 12 B ( FIG. 3D ), or any other adjustable physical structure herein described. The adjustable wing wall physical structure 12 C includes a base 28 C made of concrete or other suitable material. The base 28 C ( FIG. 4B ) can include a crest 20 C ( FIG. 4B ) and a ramp 22 C ( FIG. 4B ) constructed substantially as previously described. The base 28 C ( FIG. 4B ) can also include a vertical drop 70 C ( FIG. 4B ) downstream of the adjustable wing wall physical structure 12 C. The adjustable wing wall physical structure 12 C also includes a hinge plate 60 C attached to an upstream end of the stepped base 28 C, and a face plate 62 C attached to the hinge plate 60 C. The hinge plate 60 C allows the steel, ridged, inflated, or pliable face place 62 C to be pivoted or rotated into or out of the flow of water 16 . The face plate 62 C can also be made so as to allow vertical adjustment to further control the formation of the hydraulic formation 46 C and resist the tailwater 48 C from collapsing into the lower water surface 30 C above the adjustable lip physical structure 12 A or adjustable lip block physical structure 12 D.
[0080] The adjustable wing wall physical structure 12 C ( FIGS. 4 , 4 A and 4 B) also includes a locking mechanism 64 C for the steel face plate 62 C attached to the stepped base 28 C. In FIGS. 4 , 4 A and 4 B, the steel face plate 62 C is shown in a locked or “closed” position. In the “closed” position, the steel face plate 62 C forms a sidewall of the channel 14 - 1 ( FIG. 1A ) or 14 - 2 ( FIG. 1B ), such that the flow of water 16 in the channel 14 - 1 or 14 - 2 is constrained by the steel face plate 62 C. Alternately, the steel face plate 62 C can be pivoted upward about the hinge plate 60 C out of the flow of water 16 to an “open” position. In the “open” position, the flow of water 16 is constrained by the base 28 C, such that the width of the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ) has been effectively increased. In the “closed” position the flow of water is constrained by the steel face plate 62 C such that the width of the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ) has been effectively decreased. The dimensions and the geometry of the steel face plate 62 C can be varied as required for different applications.
[0081] Referring to FIGS. 5 , 5 A and 5 B, an adjustable block wing wall physical structure 12 E is illustrated. The adjustable block wing wall physical structure 12 E is configured to adjust the width of the channel 14 - 1 ( FIG. 1A ), 14 - 2 ( FIG. 1B ). The adjustable block wing wall physical structure 12 E can be located adjacent to, or in close proximity to, the adjustable lip physical structure 12 A ( FIG. 2A ), or any other adjustable physical structure herein described. It can be configured to control the hydraulic formation 46 D and resist the tailwater 48 D from collapsing into the lower water surface 30 D above the adjustable lip physical structure 12 A or the adjustable lip block physical structure 12 E.
[0082] The adjustable block wing wall physical structure 12 E includes a base 28 E made of concrete or other suitable material. The base 28 E ( FIG. 5B ) can include a crest 20 E ( FIG. 5B ) and a ramp 22 E ( FIG. 5B ) constructed substantially as previously described. The base 28 E ( FIG. 5B ) can also include a vertical drop 70 E ( FIG. 5B ) downstream of the adjustable block wing wall physical structure 12 E. The adjustable block wing wall physical structure 12 E is constructed of individual lip blocks 34 E that are shaped with mating keys/grooves 72 E ( FIG. 5A ) such that the lip blocks 34 E can be stacked vertically. This allows the height of the adjustable block wing wall physical structure 12 E to be adjusted as required.
[0083] Referring to FIGS. 6 , 6 A and 6 B, an adjustable crest physical structure 12 F is illustrated. The adjustable crest physical structure 12 F includes an adjustable crest 20 F ( FIG. 6A ) configured to adjust the amount of hydraulic drop across the adjustable crest physical structure 12 F. The hydraulic drop is the difference in elevation between the water surface upstream and the water surface downstream of the adjustable crest physical structure 12 F. The adjustable crest 20 F ( FIG. 6A ) functions substantially similar to the previously described static crest 20 A ( FIG. 2A ) of the adjustable lip physical structure 12 A ( FIG. 2A ). The adjustable crest physical structure 12 F also includes an adjustable ramp 22 F ( FIG. 6A ), which functions substantially similar to the previously described static ramp 22 A ( FIG. 2A ) of the adjustable lip physical structure 12 A ( FIG. 2A ). The adjustable crest physical structure 12 F ( FIG. 6A ) also includes an adjustable lip 24 F, which functions substantially similar to the previously described adjustable lip 24 A ( FIG. 2A ) of the adjustable lip physical structure 12 A ( FIG. 2A ).
[0084] As shown in FIG. 6A , the adjustable crest physical structure 12 F includes a base 28 F formed of a suitable building material such as concrete. The adjustable crest 20 F is hingedly mounted to the base 28 F on one or more hinge connections 74 F ( FIG. 6A ). The adjustable crest 20 F is movable from Position 1 , termed the “up” position, to Position 2 , termed the “down” position. In the “down” position the adjustable crest physical structure 12 F can have one-half foot or less of hydraulic drop. In the “up” position the adjustable crest physical structure 12 F can have as much as eight feet or more of hydraulic drop. The adjustable ramp 22 F is hingedly mounted to the adjustable crest 20 F on one or more hinge connections 76 F ( FIG. 6A ).
[0085] As also shown in FIG. 6A , the adjustable crest physical structure 12 F includes a placement mechanism 36 F such as a bladder, hydraulic cylinder or mechanism substantially as previously described. The placement mechanism 36 F moves the adjustable crest 20 F to the different positions. The adjustable crest physical structure 12 F also includes a fixed or variable track slide mount 78 F ( FIG. 6A ) attached to the end of the adjustable ramp 22 F. With this arrangement, movement of the adjustable ramp 22 F in the vertical direction also moves the adjustable ramp 22 F in the horizontal direction. The track slide mount 78 F ( FIG. 6A ) can be adjusted so that the end of the adjustable ramp 22 F can be lower or higher with the adjustable crest physical structure 12 F in the “up” position then in the “down” position. The adjustable lip 24 F ( FIG. 6A ) can be fixedly attached to the adjustable ramp 22 F or can be pivotably attached and operated by a second bladder, hydraulic cylinder or mechanism (not shown). The adjustable crest physical structure 12 F can be operated in substantially the same manner as the adjustable lip physical structure 12 A for producing various hydraulic formations 46 F ( FIG. 6A ).
[0086] Referring to FIGS. 7 , 7 A and 7 B, an adjustable outlet physical structure 12 G is illustrated. The adjustable outlet physical structure 12 G connects to the outlets 80 G of one or more conveyance structures 82 G such as conduits or channels hence the term “adjustable outlet”. The conveyance structures 82 G are connected to a source of water 84 G ( FIG. 7B ), such as a pump, a channel, or a pipe configured to supply a flow of water 16 G ( FIG. 7B ) at a suitable flow rate and velocity. By way of example, the flow of water 16 G can be from 30 cfs (cubic feet per second) to 2000 cfs (cubic feet per second) or more and at a Froude Number from 1.2 to 4.
[0087] The adjustable outlet physical structure 12 G ( FIG. 7B ) includes a crest 20 G ( FIG. 7B ) configured to provide a hydraulic drop across the outlet adjustable physical structure 12 G. The crest 20 G ( FIG. 7B ) functions substantially similar to the previously described crest 20 A ( FIG. 2A ) of the adjustable lip physical structure 12 A ( FIG. 2A ). The crest 20 G ( FIG. 7B ) is preferably formed at an elevation above the downstream water surface elevation to prevent backflow or reverse flow from downstream pools when there is no flow of water 16 G ( FIG. 7B ) in the conduits 82 G ( FIG. 7B ).
[0088] The adjustable outlet physical structure 12 G ( FIG. 7B ) also includes a ramp 22 G ( FIG. 7B ), which functions substantially similar to the previously described ramp 22 A ( FIG. 2A ) of the adjustable lip physical structure 12 A ( FIG. 2A ). The adjustable outlet physical structure 12 G ( FIG. 7B ) can also include an adjustable ramp 86 G ( FIG. 7B ), which functions substantially similar to the previously described adjustable ramp 22 F ( FIG. 6A ). The adjustable outlet physical structure 12 G ( FIG. 7B ) can also include an adjustable lip 24 G, which functions substantially similar to the previously described adjustable lip 24 A ( FIG. 2A ) of the adjustable lip physical structure 12 A ( FIG. 2A ).
[0089] As shown in FIG. 7B , the adjustable outlet physical structure 12 G includes a base 28 G formed of a suitable building material, such as concrete. The adjustable ramp 22 G is hingedly mounted to the base 28 G on one or more hinge connections 74 G ( FIG. 7B ). The adjustable ramp 22 G is movable from Position 1 , termed the “down” position, to Position 2 , termed the “up” position, or to any desired position in between Positions 1 and Position 2 . The ramp can be moved in this manner to account for variations in tailwater 48 G elevation or changes in flow 16 G rates.
[0090] As also shown in FIG. 7B , the outlet adjustable physical structure 12 G includes one or more first placement mechanisms 36 G- 1 for moving the adjustable ramp 86 G, and a second placement mechanism 36 G- 2 for moving the adjustable lip 24 G. As previously described, the placement mechanisms 36 G- 1 , 36 G- 2 can comprise bladders, hydraulic cylinders or jack mechanisms. In the illustrated embodiment, the first placement mechanisms 36 G- 1 comprise mechanical jacks, and the second placement mechanism 36 G- 2 comprises a bladder. The adjustable outlet physical structure 12 G takes advantage of energy (in the form of velocity head) that would otherwise be “wasted” to produce a useable hydraulic formation 46 G, such as a wave or a hole having side eddies.
[0091] With the source of water 84 G ( FIG. 7B ) for the adjustable outlet physical structure 12 G ( FIG. 7B ) being in the form of a pump, the adjustable outlet physical structure 12 G ( FIG. 7B ) can be placed in a still pool, such as a lake, swimming pool or tank, or in a river or channel. The adjustable outlet physical structure 12 G ( FIG. 7B ) can also be portable, as the source of water 84 G (e.g., pump), the conduit 82 G ( FIG. 7B ), the adjustable ramp 86 G ( FIG. 7B ), and the adjustable lip 24 G ( FIG. 7B ) can be easily transported and reassembled.
[0092] The source of water 84 G ( FIG. 7B ) can comprise a conventional propeller or mixed-flow impellor pump. Alternately, the source of water 84 G ( FIG. 7B ) can comprise a paddle wheel pump. One advantage of a paddle wheel pump is energy losses are reduced and efficiency is increased due to the desired nature of the pumped outflow. Specifically, the outflow of a paddle wheel pump has a low lift (less than 4 feet) and a high velocity (approximately 8 to 20 feet per second). The outflow of the paddle wheel pump can also be distributed across the width (cross section) of the adjustable outlet physical structure 12 G ( FIG. 7B ). This output width can thus be achieved without the need to contract, and then expand the flow as is necessary with a conventional pump.
[0093] With the source of water 84 G ( FIG. 7B ) in the form of either a pump or a paddle wheel, power can be supplied by an electric or gas engine or a water powered turbine. The return flow of the source of water 84 G can be through the bottom and/or through the side of the outlet adjustable physical structure 12 G ( FIG. 7B ). Flow routed through the bottom (below the adjustable lip 24 G) enhances the formation of the hydraulic formation 46 G ( FIG. 7B ), and decreases velocities at the downstream end of the downstream pool 88 G ( FIG. 7B ). Flow routed through the side of the adjustable outlet physical structure 12 G ( FIG. 7B ) can be used to decrease the intensity of the eddy if focused near the eddy line (i.e., the boundary between the eddy and the supercritical flow). In addition, the flow and formation of the hydraulic formation 46 G ( FIG. 7B ) can be adjusted with the pumping rate.
[0094] Referring to FIGS. 8 , 8 A and 8 B, an expandable invert physical structure 12 H is illustrated. The expandable invert physical structure 12 H ( FIG. 8B ) comprises a reinforced rubber membrane that is inflated with either air or water. Exemplary reinforcing materials include nylon, polypropylene, Kevlar, steel, and other reinforcing fibers. The expandable invert physical structure 12 H ( FIG. 8B ) can expand and rise according to a predetermined shape as controlled by the internal reinforcing. For typical applications, the expandable invert physical structure 12 H ( FIG. 8B ) can range from 2 feet to 25 feet in length and from 6 feet to 25 feet in width.
[0095] The expandable invert physical structure 12 H can be used to form a hydraulic drop for any of the previously described adjustable physical structures 12 A- 12 G. The height of the expandable invert physical structure 12 H ( FIG. 8B ) can be selected on the basis of the desired hydraulic drop with from 2 feet to 10 feet being representative. For example, as shown in FIG. 8B , the expandable invert physical structure 12 H can be placed on the invert 26 B of the channel 14 - 1 or 14 - 2 upstream of the adjustable through-flow physical structure 12 B in place of the crest 20 B ( FIG. 3A ) and ramp 22 B ( FIG. 3A ) to form hydraulic formations 46 B. As another example, the expandable invert physical structure 12 H can be used with the adjustable outlet physical structure 12 G ( FIG. 7B ) in place of the adjustable ramp 86 G ( FIG. 7B ).
[0096] Referring to FIGS. 9 and 9A , a moveable invert physical structure 12 I is illustrated. The moveable invert physical structure 12 I is configured for placement on the invert 261 of the channel 14 - 1 ( FIG. 1A ) or 14 - 2 ( FIG. 1B ). Because of it's size the moveable invert physical structure 12 I can be easily moved and placed at a desired location on the system 10 - 1 ( FIG. 1A ) or 10 - 2 ( FIG. 1B ). The moveable invert physical structure 12 I comprises a reinforced rubber membrane that is inflated with either air or water. As shown in FIG. 9A , the moveable invert physical structure 12 I can expand and rise according to a predetermined shape as controlled by the internal reinforcing. In addition, multiple moveable invert physical structure 12 I can be placed in series and adjusted to create optimal hydraulic formations such as waves, holes and eddies. Further, the spacing between the moveable invert physical structure 12 I can be adjusted to take advantage of the natural wavelength and to enhance the size and the formation of a wave train.
[0097] As shown in FIG. 9 , individual moveable invert physical structure 12 I can be made as a single element or divided into individual segments. In FIG. 9A , the cross sectional geometry of the moveable invert physical structure 12 I is semi-circular comprising between ⅛ to ½ of the circumference of a full circle. The diameter of the circular cross section is typically between 2 to 10 feet. Other curve-linear and triangular cross sections can provide similar results, but the semicircular section is the easiest and least expensive to make.
EXAMPLES
[0098] The described adjustable physical structures 12 A- 12 I have undergone extensive experimentation and testing. Experimentation included hydraulic Froude scale modeling at 1:12 scale in Woodstock Md. Over 20 configurations were tested and four configurations were selected for further testing and development.
[0099] Hydraulic Froude scale modeling at a 1:12 scale, was conducted at a hydraulics laboratory at Colorado State University in Fort Collins Colo.
[0100] Testing and observation of six full scale prototypes built in McHenry, Md. was also conducted by the inventor. Survey data was taken and wave formations were documented. A second series of testing and observations was also conducted by the inventor. This testing included collecting formalized input from over 60 tip athletes and testing by the inventor.
[0101] While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and subcombinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.
|
An adjustable physical structure for producing hydraulic formations for whitewater recreationalists includes a control structure, and an adjustable lip located downstream of the control structure. The control structure can include a crest and a ramp. The crest constricts and/or elevates (dams) the flow water to increase it's energy and focus the flow of water. Downstream of the crest, the ramp routes the flow of the water to the adjustable lip. The ramp can have varying and non-linear slopes and plan configurations. Additionally, the ramp can be static or adjustable to elevate the flow of water and vary the velocity and energy of the supercritical flow as it is passed to the adjustable lip. An adjustable invert physical structure comprises a shaped structure configured for placement on the invert of the channel. The adjustable invert physical structure can be moved or adjusted in horizontal and/or vertical directions to shape the flow of water.
| 0
|
BACKGROUND OF THE INVENTION
This invention relates to a variable frequency characteristic circuit for a vehicular acoustic device.
Acoustic characteristics inside a vehicle are different from those in the general sound field and have unique patterns because the sound field is surrounded by reflective surfaces such as window glass and a dashboard and by sound absorbing surfaces such as seats. Furthermore, the space of the sound field is narrow unlike the more normal home or office. For instance, the front seats are located roughly in the center of the longitudinal direction of the vehicle with sound sources (speakers) respectively arranged in both front doors. The resultant sound pressures has a frequency characteristic that peaks at about 250 Hz and 1-2 kHz and in which a dip occurs at about 700 Hz.
However excellent are the characteristics that a speaker unit has in an anechoic room, it is impossible to obtain a flat frequency characteristic from such a speaker unit installed in a vehicle. To compensate this disturbance, the frequency characteristics have conventionally been corrected by inserting a variable frequency characteristic circuit in the reproducing system of a vehicular acoustic device. Moreover, a sound quality adjusting circuit for adjusting the sound quality is also normally inserted in the reproducing system of the acoustic device.
FIG. 5 shows a circuit diagram of a conventional acoustic adjusting circuit and a variable frequency characteristic circuit. In FIG. 5, there is shown a buffer amplifier 1 formed with an operational amplifier OP 1 receiving an input signal as a non-inverted input. In a sound quality adjusting circuit 4, a resistor R 1 , a variable resistor VR 1 , and a capacitor C 1 , are connected in series between the output of the operational amplifier OP 1 and ground. A resistor R 2 is connected in parallel across the variable resistor VR 1 Capacitors C 2 , and C 3 are respectively connected from both ends of the variable resistor VR 1 and its slider (output). These elements constitute a resonance circuit 2 for adjusting the bass sound quality (low frequency sound). Moreover, a resistor R 3 , a capacitor C 4 , a variable resistor VR 2 , a capacitor C 5 and a resistor R 4 are connected in series between the output of the operational amplifier OP 1 and ground. These elements constitute a resonance circuit 3 for adjusting the treble (high frequency sound). The sliders of variable resistors VR 1 and VR 2 are connected through resistors R 5 and R 6 and the contact common to them is grounded through resistors R 7 and R 8 and a capacitor C 6 . The contact common to the resistors R 7 and R 8 is connected to the inverted input of the operational amplifier OP 1 . The sound quality of the bass and treble are respectively adjusted by the variable resistors VR 1 and VR 2 in the sound quality adjusting circuit 4 thus arranged.
The output signal of the sound quality adjusting circuit 4 is applied through a resistor R 9 to the non-inverted input of another operational amplifier OP 2 . The operational amplifier OP 2 and a feedback resistor R 10 connected between the output and inverted input of the operational amplifier OP 2 constitute a buffer amplifier 5. Resonance circuits 6 and 7 whose resonance frequencies are different from each other are connected between the non-inverted input of the operational amplifier OP 2 and ground through damping resistors R 11 and R 12 , whereas a resonance circuit 8 is connected between the inverted input of the operational amplifier OP 2 and ground through a damping resistor R 13 . There results a variable frequency characteristic variable circuit 9 for correcting the transmission frequency characteristics inside a vehicle.
Since the sound quality adjusting circuit 4 and the frequency characteristic variable circuit 9 each have their own separate buffer amplifiers, as described above, the combined circuit is disadvantageous in being not only costly but also handicapped in view of acoustic performance. That is the signal-to-noise ratio (S/N) and the distortion factor are degraded because two buffer amplifiers are inserted on the signal line.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above problems, and it is therefore an object of the invention to provide a variable frequency characteristic circuit for use in a vehicular acoustic device designed to improve acoustic performance and to reduce cost.
The frequency characteristic variable circuit for a vehicular acoustic device according to the present invention comprises a single buffer amplifier inserted in a signal line. A plurality of resonance circuits correct the vehicular transmission frequency characteristics and a plurality of resonance circuits adjust the sound quality to provide both sound field correcting and sound quality adjusting functions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing an embodiment of the present invention.
FIG. 2 is the frequency characteristic diagram of the circuit of FIG. 1.
FIG. 3 shows the frequency characteristic diagrams inside a vehicle before correction (alternately long and short dash line) and after correction (continuous line).
FIG. 4 is the frequency characteristic diagram inside a vehicle at the front seats when sound sources are arranged in front doors.
FIG. 5 is a circuit diagram showing a conventional variable circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the accompanying drawings, an embodiment of the present invention will be described in detail.
FIG. 1 is a circuit diagram embodying the present invention. In FIG. 1, an input signal is applied to an operational amplifier OP 0 as a non-inverted input through a resistor R 14 . The operational amplifier OP 0 and a feedback resistor R 15 connected between the output and the inverted input of the operational amplifier OP 0 constitute a buffer amplifier 10. Resonance circuits 11 and 12 whose resonance frequencies are different from each other are connected between the non-inverted input of the operational amplifier OP 0 and ground (reference potential) through respective damping resistors R 16 and R 17 . By a resonance circuit is meant a circuit, such as an LC circuit, having a minimum impedance at the resonance frequency. A resonance circuit 13 is connected between the inverted input of the operational amplifier OP 0 and ground through a damping resistor R 18 . The circuit impedance and thus the resonant frequency of each of the resonance circuits 11-13 and the resistance of each of the resistors R 16 -R 18 are fixed. If the resonance frequencies of the respective resonance circuits 11-13 are denoted by f1, f2 and f3 and the corresponding resonance sharpness by Q 1 , Q 2 and Q 3 , then exemplary values are about 250 kHz for f 1 , 1 to 2 kHz for f 2 , about 700 Hz for f 3 , 1 to 4 for Q, and 3-7 for both Q 2 and Q 3 . However. it is not necessary that Q 2 equal Q 3 . As a result, fixed frequency characteristics inside the vehicle are obtained, as shown in FIG. 2, with dips at f 1 and f 2 and a peak at f 3 . This same characteristic is represented by an inverted curve of the transmission frequency characteristics shown in FIG. 4. In consequence, the peaks and dips of the transmission frequency characteristics inside the vehicle before correction as shown by a alternately long and short dash line in FIG. 3 are corrected by the resonance circuits 11-13 as shown by a continuous line in FIG. 3.
Additionally, variable resistors VR 3 and VR 4 are connected in parallel between the non-inverted and inverted inputs of the operational amplifier OP 0 and resonance circuits 14 and 15 whose resonance frequencies are different from each other are connected between the outputs (sliders) of the respective variable resistors VR 3 and VR 4 and ground (reference potential). If the resonance frequencies of the resonance circuits 14 and 15 are denoted by f 4 and f 5 and the corresponding resonance sharpness by Q 4 and Q 5 , then exemplary values are about 80 Hz for f 4 , about 8 KHz for f 5 and between 0.5 and 1 for Q 4 and Q 5 , both being equal with these values, a low frequency can be boosted, cut or made flat by the variable resistor VR 3 , whereas a high frequency can be boosted, cut or made flat likewise by the variable resistor VR 4 . In other words, bass and treble sound quality is controllable by the variable resistors VR 3 and VR 4 .
The resonance circuit 11 or 12 may be omitted depending on the car model or limitation of cost.
At the present time, a variable frequency characteristic circuit having five resonance circuits is employed for a vehicular sound device, as described above. Reference has been made to the use of three resonance circuits for the correction of the sound field and of the other two resonance circuits for adjusting sound quality in the above embodiment. However. another embodiment may be employed having two resonance circuits for the correction of the sound field and three resonance circuits for adjusting sound quality. Further, two additional resonance circuits may be connected between the operational amplifier and ground and, by setting the resonance frequencies at about 50 Hz and 10 kHz, the frequency characteristics shown by a broken line of FIG. 2 are obtainable.
In the above embodiment, moreover, two resonance circuits for adjusting sound quality were used to deal with two ranges of sound, bass and treble, three resonance circuits may be used to comply with three ranges of sound, bass, mid-range and treble. Although the resistance of the disclosed variable resistor is changeable continuously, the variable resistance may be allowed to change discontinuously using a switch and, by preparing combinations of such resistors, they may be made to function as a tone selector.
Although a description was given of a case where the transmission frequency characteristics at the front seats were corrected in such acoustic conditions in which sound sources (speakers) were arranged in both left and right front doors, the peaks and dips of the transmission frequency characteristics at the rear seats may also be corrected by setting the circuit constant of each resonance circuit in such a manner as to make obtainable frequency characteristics represented by an inverse curve relative to the transmission frequency characteristics involved because the transmission frequency characteristics at the rear seats are different in terms of acoustic conditions.
In the case of employing a variable frequency characteristic circuit having more than six resonance circuits, each of the resonance circuits may, as appropriate, be distributed among the circuits for the correction of the sound field and the circuits for adjusting sound quality.
As set forth above, only a single buffer amplifier is inserted in the signal line in accordance with the variable frequency characteristic circuit of the present invention. Because one buffer amplifier can be dispensed with, as compared with the conventional variable circuits, acoustic performance including the S/N, distortion factor, separation and the like is improved, whereas production costs become reducible. If the circuit is formed as an IC (Integrated Circuit). the space required for its installation may also be minimized.
|
A variable frequency characteristic circuit to be used in compensating the frequency characteristics in an audio device in a vehicle. A single operational amplifier is used. Different resonance circuits of different frequencies are connected from ground to either the inverting or non-inverting inputs in order to provide local peaks and dips. Two variable resistors are connected in parallel between the inverting and non-inverting inputs. Different resonance circuits of different frequencies are connected from ground to center taps of the variable resistors to provide treble and base control.
| 7
|
TECHNICAL FIELD
The invention relates generally to the field of image processing of colour images and more particularly to histogram and chrominance processing of YUV colour video signals for reproduction on the display screen of for instance a colour TV set.
BACKGROUND OF THE INVENTION
Image processing techniques comprising histogram processing, such as histogram equalisation is known within the art. Histogram processing may serve many different purposes, for instance enhancing the contrast of an image. The theory of histogram equalisation and matching are well known, and for a continuous signal it is theoretically possible to obtain perfect histogram equalisation or a match to a specific distribution. Using the same approach it is possible to obtain an approximate equalisation/match for a discretised histogram. It is furthermore known to apply processing of the chrominance of a video signal in order to attain optimal perceived quality of a colour image for instance on a television screen.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and corresponding system for improving the perceived visual quality of images for instance displayed on a colour television screen. According to a preferred embodiment of the method and system of the invention account is taken both of the video signal itself and of characteristics of the ambient light, for instance sensed by suitable sensor means provided on a TV set.
According to an aspect of the present invention there is provided a histogram processing method and system for scaling an input video signal such that the maximum dynamic range is utilised and where the quality of the perceived image is also optimised.
According to the present invention there is provided a method and corresponding system that carry out histogram processing and chrominance processing, which processings according to a specific embodiment of the invention can be performed sequentially in two consecutive modules. The main functionalities of these processings will be described in detail in the detailed description of the invention. The input is a component signal, i.e. luminance and colour difference signals. This is generally denoted Y′UV, with Y′ being the luminance component and U and V the colour difference components.
The main functionality of the histogram processing according to the invention is to provide a transfer function, for the image pixels, to obtain enhanced image dynamics and to provide a scaling factor or chrominance gain for scaling the chrominance components when luminance has been changed by the histogram processing. The said transfer function is also according to a specific embodiment modulated according to a signal provided by an ambient light sensor. If the ambient light intensity is high, the image dynamics are moved towards the low image levels, and vice versa. The black level is set according to a measure of the lowest levels present in the image and a function dependent on the average image level. As mentioned, additionally the histogram processing provides a chrominance scaling value. The chrominance scaling is according to a specific embodiment of the invention based on the ratio of a standard linear transfer function (an identity mapping) T(k) and the transfer function T (k) derived by the histogram processing according to the invention. The scale value is calculated at the average level of the unprocessed image. Thus as the processing is likely to increase/decrease the luminance at the average level, the chroma components are multiplied by the scale value to achieve a similar increase/decrease. This approximately preserves the saturation of the image.
The subsequent chrominance processing represents a selective chroma adjustment. The processing considers each individual pixel (p), having co-ordinates (U,V) p in the U,V-plane. Based on the pixel co-ordinates, the (U,V) p components are scaled by a specific gain. The gain will typically be greater than or equal to one, thus maintaining or increasing the saturation of the pixel. Having the gain dependent on the pixel co-ordinates allows selective processing, such that e.g. pixels within a specific region of the (U,V) plane, will be unaltered. This is desirable in e.g. the (U,V) region representing typical skin colour. The magnitude of the scaling will in general depend on the magnitude of the (U,V) p vector in such a way that small magnitudes will receive a relatively large scaling and vice versa.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by reference to the following detailed description of embodiments of the invention taken in conjunction with the figures, where:
FIG. 1 shows a schematic block diagram illustrating the main functionalities of the method and system of the invention;
FIG. 2 shows a schematic block diagram illustrating the overall effect of applying the histogram and chrominance processing according to the invention;
FIGS. 3( a ) and ( b ) show a flow chart summarising the main processing steps for carrying out the histogram processing according to an embodiment of the invention;
FIG. 3( c ) shows a flow chart summarising the main processing steps for carrying out the chrominance processing according to an embodiment of the invention;
FIG. 4 shows an illustrative graphical representation of a gain function provided by the histogram and chrominance processing according to the invention; and
FIG. 5 shows an example of an interpolated mapping for an 8-bit signal input-output function derived by the method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 there is shown a schematic block diagram illustrating the main functionalities of the method and system of the invention. The shown processing system 1 receives an input video signal 6 represented by the components Y′UV according to the known YUV model for representing a colour image, where the Y component represents the luminance (brightness) of the individual pixels p of the image and U and V represent the chrominance (colour) components, mapping each representable colour into a two-dimensional UV-space. The shown embodiment of the system 1 according to the invention comprises an inference system 2 for carrying out the histogram and chrominance processing according to the invention. This system 2 provides output variables 9 , 10 , 11 and 12 relating to saturation, brilliance, contrast and gamma that by means of the display controlling system 3 , which also receives the original Y′UV video signal 6 , provide the final output signal 8 to the display means 4 . According to a specific embodiment of the invention, the inference system (or specifically the histogram processing means as will be described in detail below) is furthermore provided with an output signal from an ambient light sensor that senses the intensity (or other related quantity) of the ambient light.
Histogram and Chrominance Processing:
Histogram and chrominance processing can be viewed as an inference system, which affects various parameters via modifications of the incoming video signal. The modification is based on the properties of the incoming video signal and (according to a specific embodiment of the invention) an ambient light sensor. The resulting parameters may be based on both global properties (the entire image field) and local properties.
With reference to FIG. 2 , the inference system 2 consists basically of two consecutive modules 13 and 14 , with the main functionalities described below. The input is typically a component signal i.e. luminance and colour difference signals. This is generally denoted Y′UV, with Y′ being the luminance component, and U, V the colour difference components. The first module is the histogram processing block 13 , by means of which a luminance transfer function T (k) and a chrominance scaling factor or chrominance gain g c 16 is determined. The second module is the chrominance processing block 14 , carrying out selective chroma adjustment (global chroma adjustment is carried out in block 17 , cf. below). The original input video signal (Y′UV) IN 6 results by the processing carried out in the modules 13 and 14 in the output signal (Y′UV) OUT1 15 that after scaling of the chrominance components U and V by the chrominance gain g c as shown in the functional block 17 results in the final output video signal (Y′UV) OUT2 18 . In the following a detailed description of the processing actually carried out in the functional blocks 13 and 14 will be given
Histogram Processing:
In the histogram processing, the black level is set according to a measure of the lowest level present in the image, and a function dependent on the average image level. The transfer function of the histogram processing block 2 is also modulated according to the input 5 of an ambient light sensor. If the ambient light intensity is high, the image dynamics are increased for the low image levels, and vice versa. In addition, the histogram processing block 2 provides a chrominance scaling value, the chrominance gain g c . The chrominance scaling is based on the ratio of a linear transfer function with offset, and the total transfer function derived by the processing. The global chrominance scale value is calculated at the average level of the unprocessed image, using only the black level offset. Thus, as the processing is likely to increase/decrease the luminance at the average level, the chroma components are multiplied by the scale value to achieve a similar increase/decrease. This approximately preserves the saturation of the image.
With reference to the flow charts shown in FIGS. 3( a ), ( b ) and ( c ) a more detailed description of the steps carried out in an embodiment of the invention will be given.
Initially a histogram (ref, number 19 ) of luminance values of the incoming video signal Y′UV (reference number 6 of FIGS. 1 and 2 ) is formed. This is done by dividing the total range of the luminance signal into N non-overlapping subranges (denoted bins). The bins can have any distribution, and can be of equal size, or the sizes may grow e.g. exponentially. Each sample (or, if the signal is subsampled, less than that) of the signal then adds to the count of the samples in the respective bin. This produces a histogram of luminance sample values, with an appropriate resolution. The histogram of luminance values of the image field is denoted as: H(k)=n k , where k denotes the bin number, and n k denotes the number of samples in the field falling within the levels represented by bin k. In the following description ‘histogram’ denotes the normalised histogram (ref. number 20 ): p(k)=n k /n, where n is the total count of the histogram—i.e. p(k) is the percentage of counts that fall within bin k.
The normalised histogram 20 is used for calculation of the average luminance level (ref. number 21 ):
Y AVG = ∑ k = 0 N - 1 a ( k ) p ( k )
where α(k) is the average level represented by bin k. The calculated average is used subsequently in the algorithm.
The histogram p(k) is according to one specific embodiment of the invention in functional block 22 weighted by a power function k α such that: p 1 (k)=p(k)k α , kε{0, . . . , N−1}, where α is a constant. Subsequently p 1 (k) is normalised (ref. number 23 ) such that
∑
k
=
0
N
-
1
p
1
(
k
)
=
1.
It should be noted that weighting of the histogram p(k) by a power function k α is only one specific example of a weighting function that can be applied in the histogram processing according to the invention. Generally the histogram p(k) can according to the invention be weighted by a weight function w(k) that can exhibit other and possibly more complicated functional relationships with the parameter k (the bin number) than the power function described above.
The power function weighted luminance histogram is then clipped (ref. number 24 ) by thresholding each bin at a particular maximum level such that: p 2 (k)=min[p 1 (k),c(k)], kε{0, . . . , N−1} where c(k)is a function setting the clipping level for bin k.
After these modifications a cumulative histogram is calculated (ref. number 25 ):
p
3
(
k
)
=
∑
i
=
o
k
p
2
(
i
)
,
k
∈
{
0
,
…
,
N
-
1
}
A second cumulative luminance histogram (ref. number 26 ) is also formed from the un-modified histogram:
p
C
(
k
)
=
∑
i
=
o
k
p
(
i
)
,
k
∈
{
0
,
…
,
N
-
1
}
.
The cumulative luminance histogram p C (k) is used (ref. number 27 ) for detecting the luminance level, for which the cumulative proportion exceeds a small but fixed percentage of the sample counts. The level found from this, denoted bl 1 , is used as an offset for the signal, which by subtraction moves the lowest signal level (occurring within some time period) to the lowest valid signal level. Additionally the offset is increased in relation to the average luminance of the image. This additional offset, bl 2 , is found (ref. number 28 ) from a scaled power-function relation: bl 2 =c 1 Y AVG p where c 1 , β are constants. With reference to block 29 the total offset, bl, is the sum of the two offsets bl 1 ,bl 2 , thresholded at a maximum offset b max as: bl=min[bl 1 +bl 2 , b max ] The total offset value bl is temporally filtered (ref. number 30 ) by a general finite impulse response filter, typically with a low-pass characteristic to avoid large fluctuations.
Referring to block 31 of FIG. 3( b ) an additional step of the algorithm according to this embodiment of the invention partially establishes the transfer function of the histogram processing block 2 based on the ambient light level 5 . Taking as reference an identity mapping: T(k)=k, which is transformed by the total offset described above such that the transfer function is: T(k)→T(k)=k−bl, the effect of the ambient light level is to transform this by a power function relation using two functions:
T 1 ( k ) = T ( k ) β = ( k - bl ) β , T 2 ( k ) = T ( k ) 1 β = ( k - bl ) 1 β , β ∈ ] 0 , 1 [ ,
k ∈ { 0 , … , N - 1 }
which are weighted to produce a transfer function by the relation:
{circumflex over (T)} ( k )=τ T 1 ( k )+(1−τ) T 2 ( k ), τε[0,1], kε{0, . . . , N−1}
The parameter τ reflects the ambient light intensity, e.g. by having a linear relation with a particular light intensity range. Using a β which does not deviate much from 1, the relation for {circumflex over (T)}(k) can produce an approximately linear transfer function for some particular τ. If the ambient light intensity is high the T 1 (k) function will receive the largest weight, and vice versa. This has the effect of increasing the dynamics for the low signal levels at high ambient light intensity, and vice versa. This results in a mapping, which provides a better utilisation of the available dynamic range, in accordance with human contrast sensitivity.
Referring to block 32 after these transformations a weighted summation of p 3 (k) and {circumflex over (T)}(k) is formed as: T (k)=s(p 3 (k)+c 2 {circumflex over (T)}(k)), where s is a scaling parameter, which normalises T (k) to utilise the maximum signal output range. The parameter c 2 controls the relative weighting of the two transfer functions, and thereby the weighting of histogram equalisation versus ambient light adaptation. The transfer function T (k) provides the desired input-output mapping. Thus, T(k) represents the transfer function from the input signal Y′UV (reference numeral 6 ) to the output signal of the histogram processing block 13 in FIG. 2 .
Since the luminance mapping is changed by this transfer function, a global chrominance gain, g c is calculated as: g c = T (Y AVG )/T(Y AVG ) as shown in block 33 . Thus, if at the average level, the luminance has increased, the chrominance signals will be multiplied by an equal factor and vice versa. The g c value is bounded within an interval of unity gain. If it falls outside this interval, it is set at the interval minimum/maximum. The global chrominance scaling effected by g c is applied after the chrominance processing described below in connection with FIG. 3( c ).
If the signal range has been quantized to a lower resolution for histogram processing, the resulting transfer function can be scaled to the proper range by using an interpolation method
Chrominance Processing:
The subsequent chrominance processing 14 according to the invention is described below with reference to FIG. 3( c ). The chrominance processing represents a selective chroma adjustment. The processing considers each individual pixel: p=(Y p ,U p ,V p ). The pixel chrominance co-ordinates: p c =(U p ,V p ) are used for calculating a local (i.e. individual for each pixel) chrominance gain. The chrominance components can be used as indices for e.g. a table 34 containing the gain values. Alternatively the gain could be calculated from a mathematical function 35 . Regardless of method, a function g(U p ,V p ) provides the local gain value for each individual pixel. The chrominance scaled pixel is then given by:
p s =( Y′ p ,g ( U p ,V p ) U p ,g ( U p V p ) V p ),
forming the output 15 from the chrominance processing block 14 .
Referring again to FIG. 2 after application of the global chrominance gain g c , derived by the above luminance histogram processing the output (Y,U,V) co-ordinates of the pixel become:
p S =( Y′ p ,g c g ( U p ,V p ) U p ,g c g ( U p ,V p ) V p ).
The gain from the chrominance processing, i.e. g(U p ,V p ), will typically be greater than or equal to one, thus maintaining or increasing the saturation of the pixel. An illustrative example of such a gain function, where the gain is represented by the grey tone value, where black indicates unity gain and white indicates a gain value >1, is given in FIG. 4 , where (U,V)=(0,0) is located at the centre. For this gain function, most of the (U,V) plane has a homogeneously decreasing gain as a function of (U,V) magnitude. A specific region 37 is set at unity gain, having a smooth transition to the surrounding gain values. In the figure, black indicates unity gain, and white indicates the maximum gain value in the table.
Having the gain dependent on the pixel co-ordinates in this way allows selective processing, such that e.g. pixels within a specific region of the (U,V) plane, will be unaltered. This is desirable in e.g. the (U,V) region representing typical skin colour. The magnitude of the scaling will in general depend on the magnitude of the (U,V) vector, in such a way that small magnitudes will receive a relatively large scaling and vice versa.
Referring again to FIG. 1 , the four shown parameters: saturation 9 , brilliance 10 , contrast 11 and gamma 12 are related to various of the quantities determined as described above and shown in the flowchart in FIG. 3 . Thus, saturation 9 is primarily influenced by the chrominance gain g c which is the direct scaling of the chrominance components U p , V p resulting from the histogram processing. The chrominance processing furthermore influences the chrominance components U p , V p of the individual pixels by multiplication by a constant (per pixel) being typically larger than or equal to unity. This furthermore either maintains or increases the saturation 9 . Brilliance 10 is primarily influenced by the total off-set bl that improves the black level. Contrast 11 is primarily influenced by the quantity p 3 (k) being included in the expression T (k)=s(p 3 (k)+c 2 {circumflex over (T)}(k)) in that utilisation of p 3 (k) alone would have provided approximate histogram equalisation. This would, however, lead to a rather drastic effect on the image, which is according to this embodiment of the invention counteracted by using the two transfer functions in the expression for T (k). The parameter gamma 12 is directly influenced by the second term in the above expression, i.e. c 2 {circumflex over (T)}(k), i.e. the transfer function formed based on the intensity of the surrounding light. The quantities T 1 (k) and T 2 (k) in {circumflex over (T)}(k) can reduce or increase, respectively, the gamma value of the system and the effect hereof is a change of the dynamics of the image.
For the parameter saturation 9 the effect can thus be described for each individual pixel, in that the chrominance signal is changed relative to the luminance signal. For the remaining of the four parameters shown in FIG. 1 , i.e. brilliance 10 , contrast 11 and gamma 12 , it is only relevant to regard the effect for the entire image, as the effect results from the signal values being stretched over the interval of these values in order to attain a new distribution of signal values.
Calculation of the global chrominance gain g c is in the following illustrated by a specific (and simplified) numerical example of histogram processing according to the invention.
Consider the expression for the transfer function T (k):
T ( k )= s ( p 3 ( k )+ c 2 {circumflex over (T)} ( k ))
In the following example, it will be assumed that the number of input levels have been quantizised into ten bins (in an actual implementation this number will typically be larger). It is furthermore assumed that the values of p 3 (k) and {circumflex over (T)}(k) for each bin number are as given in TABLE 1 below:
TABLE 1
k
0
1
2
3
4
5
6
7
8
9
p 3 (k)
0.0000
0.1279
0.2768
0.3961
0.4246
0.4901
0.6412
0.7894
0.8556
1.0000
{circumflex over (T)}(k)
0.0000
0.2148
0.3489
0.4635
0.5669
0.6627
0.7529
0.8387
0.9209
1.0000
If it is furthermore assumed that c 2 =8 the values for the sum of p 3 (k) and c 2 {circumflex over (T)}(k)given in TABLE 2 below will be obtained:
TABLE 2
k
0
1
2
3
4
5
6
7
8
9
p 3 (k) + c 2 {circumflex over (T)}(k)
0.0000
1.8463
3.0684
4.1038
4.9594
5 7916
6 6644
7 4988
8.2225
9 0000
Assuming furthermore that the final transfer function concerns an 8-bit video signal (256 levels, all levels used as valid signal data), the constant (scale factor) s is used for scaling the output appropriately, in this example yielding: s=255/9. The values of the total transfer function T (k) given in TABLE 3 below are then obtained:
TABLE 3
k
0
1
2
3
4
5
6
7
8
9
T (k)
0.00
52.31
86.94
116.27
140.52
164.10
188.83
212.47
232.97
255.00
The above data can be used for interpolation by standard methods to the desired number of input-output levels.
For the data shown above, an interpolated mapping for 8-bit signal input-output is given in FIG. 5 . This mapping will add dynamics to the low signal levels, at the expense of decreased dynamics for the higher image levels. After interpolation T (k) is now defined for the desired input levels. In this example for kε{0, 1, . . . , 255}.
Assuming now that Y AVG =140, then T (Y AVG )= T (140)=162.
T(k) is in this example an identity mapping minus the offset bl, i.e. T(k)=k−bl. Assuming that bl=1, T(140)=139.
Finally, the chrominance gain g c can be calculated:
g
c
=
T
_
(
Y
AVG
)
T
(
Y
AVG
)
=
162
139
≈
1.17
The average luminance has thus been increased by the histogram processing method according to the invention and the chrominance components should be scaled accordingly by g c .
|
The present invention relates to a method and corresponding system for improving the perceived visual quality of images for instance displayed on a color television screen. According to the invention, there is provided a means for carrying out histogram processing ( 13 ) for scaling an input video signal ( 6 ) such that the maximum dynamic range is utilised and where the quality of the perceived image is also optimised. According to the invention, the histogram processing ( 13 ) provides a transfer function for the image pixels to obtain enhanced image dynamics and also to provide a chrominance gain (g c ) for scaling the chrominance components, when the luminance has been changed by the histogram processing. According to the invention, the histogram processing can also take variations of the ambient light into account ( 5 ). The method and system according to the invention can be implemented by a histogram processing block ( 13 ) providing a luminance transfer function followed by a chrominance processing block ( 14 ), where the latter represents a selective chroma adjustment considering each individual pixel of an image.
| 7
|
FIELD OF THE INVENTION AND RELATED ART
[0001] The present invention relates to a fibrous aggregate formed by processing fibrous material comprising fibers in particular, a fibrous aggregate which is relatively low in density and is relatively thick. It also relates to a thermal method for forming such a fibrous aggregate, and an apparatus for forming such a fibrous aggregate.
[0002] Conventional methods for forming a fibrous aggregate, which are widely in use, may generally be classified into two groups: the needle punching group and the thermal group. In certain cases, a needle punching method and a thermal method are independently used, whereas in other cases, they are used in combination.
[0003] Next, the two groups of fibrous aggregate forming methods will be briefly described.
[0004] (1) Needle Punching Method
[0005] This is a method for continuously forming a sheet of fibrous aggregate by entangling fibers among themselves; multilayered fibrous material is reciprocally punched through with the use of a needle punching machine which uses a needle called a felting needle.
[0006] (2) Thermal Method
[0007] This is a method for forming a fibrous aggregate by thermally welding fibers among themselves; a predetermined amount of heat is applied to multilayered fibrous material comprising plural types of fibers different in melting point, so that the fibers with the lower melting point (bonding material) melt and weld the fibers with the higher melting point (structural material), at the intersections of the fibers with the higher melting point. In other words, according to a thermal method, the fibers with the higher melting point serve as structural material, whereas fibers with the lower melting point serve as bonding agent. As for typical thermal methods, there are a method called a heated air conveyer heating chamber method, in which multilayered fibrous material is continuously fed into a heated air conveyer heating chamber to form a continuous form of fibrous aggregate, a method called a molding method, or a batch method, in which multilayered fibrous material is packed into a mold of a predetermined size and is heated to form a block form of fibrous aggregate, which has a predetermined size (size and shape).
[0008] Next, the two methods will be described in more detail.
[0009] (2-a) Heated Air Conveyer heating chamber Method
[0010] [0010]FIG. 12 is a schematic sectional view of a conventional heated air conveyer heating chamber used for a thermal fibrous aggregate forming method. As is evident from FIG. 12, this heated air conveyer heating chamber 500 has a pair of mesh belts 510 and 520 , which are placed in a manner to vertically oppose each other, with the provision of a predetermined gap between the two belts, in order to move the multilayered fibrous material 600 , in the leftward direction of the drawing, while compressing the multilayered fibrous material 600 from the top and bottom sides (in the direction in which the fibers are stacked), as the multilayered fibrous material 600 is fed from the upper right direction of the drawing. The multilayered fibrous material 600 is actually layers of webs of sheathed fiber. Each web has been produced with the use of a carding machine (unillustrated), a cross-laying machine (unillustrated), or the like, and the fibers in each web have been laid more or less in parallel. The weight per unit of area of the multilayered fibrous material 600 is selected in accordance with its usage. Further, the multilayered fibrous material 600 comprises plural types of fibers different in melting points.
[0011] The distance between the two mesh belts 510 and 520 is approximately equal to the thickness of the final product, or a continuous fibrous aggregate 650 , and can be adjusted as necessary. The thickness H of the continuous multilayered fibrous material 600 fed into the heated air conveyer heating chamber 500 is greater that the gap h between the two mesh belts 510 and 520 . After being fed into the heated air conveyer heating chamber 500 , the continuous multilayered fibrous material 600 is compressed all at once to the thickness h by the mesh belt 510 and 520 , and is thermally formed into the continuous fibrous aggregate 650 while remaining in the compressed state.
[0012] In order to thermally form the continuous multilayered fibrous material 600 into a continuous fibrous aggregate 650 , an air sending chamber 530 for blowing air, and an air receiving chamber 540 for suctioning the heated air blown out of the air sending chamber 530 , are provided in the heated air conveyer heating chamber 500 . The air sending chamber 530 is provided with an air supplying hole 531 and a plurality of perforations, and is located above the path of the multilayered fibrous material 600 , within the heated air conveyer heating chamber 500 . Heated air is blown into the air sending chamber 530 through the air supplying hole 531 , and is blown out of the air sending chamber 530 through the plurality of perforations 532 to be blown at the multilayered fibrous material 600 . The air receiving chamber 540 is located below the path of the multilayered fibrous material 600 , and is provided with a plurality of perforations 542 and a plurality of air suctioning holes 541 . As the heated air having been blown at the multilayered fibrous material 600 from the air sending chamber 530 , as described above, passes through the multilayered fibrous material 600 , the heated air is suctioned into the air receiving chamber 540 through the plurality of perforations 542 , and is exhausted through the plurality of air suctioning holes 541 .
[0013] Upon being introduced into the heated air conveyer heating chamber 500 , the continuous multilayered fibrous material 600 is heated by the heated air blown out of the air sending chamber 530 until its temperature rises to a predetermined one. As described above, the continuous multilayered fibrous material 600 is continuous layers of plural types of fibers different in melting point. Therefore, the fibers, which have a relatively lower melting point, can be melted by setting the temperature of the heated air to a temperature which is higher than the melting point of the fibers with a relatively lower melting point, and is lower than the melting point of the fibers with a relatively higher melting point, so that the fibers with the relatively higher melting point, can be bonded among each other at their intersections, with the melted fibers with the lower melting point acting as bonding agent, to effect a continuous fibrous aggregate 650 , which has a predetermined thickness.
[0014] (2-b) Mold Based Method
[0015] [0015]FIG. 13 is a drawing for depicting one of conventional methods for forming a fibrous aggregate. A block of multilayered fibrous material 610 is identical in material to the continuous multilayered fibrous material 600 used in the heated air conveyer heating chamber based method, except that it is in the form of a block. More specifically, as shown in FIG. 13( a ), the multilayered fibrous material block 610 comprises several layers of fibers, in which fibers are aligned approximately in parallel in a certain direction a, and which are stacked in a direction b perpendicular to the direction in which the fibers are aligned in each layer. This multilayered fibrous material block 610 is placed in an aluminum mold 700 , and is covered with a lid 710 as shown in FIGS. 13 ( b ) and ( c ). At this stage, the multilayered fibrous material block 610 in the mold 700 has been simply compressed in the stacking direction b, in the mold 700 . Then, a block of fibrous aggregate is obtained by heating the mold 700 until the aforementioned condition is satisfied.
[0016] However, the above described methods for forming a fibrous aggregate block have such problems of their own that will be described below.
[0017] (1) Needle Punching Method
[0018] A needle punching method physically causes fibers to entangle, with the use of a felting needle. Therefore, a fibrous aggregate produced by a needle punching method is hard, thin, and high in bulk density. In other words, a soft and thick fibrous aggregate which is low in bulk density is difficult to produce using a needle punching method.
[0019] ( 2 a ) Heated Air Conveyer heating chamber Based Method
[0020] In a heated air conveyer heating chamber based method, heated air is blown at multilayered fibrous material from above, and therefore, the fibers in the layers on the top side tend to soften before those in the layers on the bottom side. As a result, the layers on the top side tend to be collapsed by the pressure from the heated air from above, and also the self-weight of the layers of fibers, causing the layers on the top side to become higher in bulk density than the layers on the bottom side. In other words, it is difficult to produce a fibrous aggregate uniform in density using a heated air conveyer heating chamber based method. One of the solutions to this problem is to reduce the velocity of the heated air. However, reducing the heat air velocity makes it impossible for the heated air to pass through the multilayered fibrous material, creating a problem in that it is virtually impossible to heat the bottom portion of the multilayered fibrous material.
[0021] Therefore, producing a soft and thick fibrous aggregate which is low and uniform in bulk density using a heated air conveyer heating chamber based method is as difficult as producing it using a needle punching method, admitting that a relatively hard sheet of fibrous aggregate which is relatively high in bulk density can be as easily produced by the latter method as the former method. In addition, the layered fibrous material is heated while being kept in the compressed state by the mesh conveyer, and therefore, there is a problem in that the pattern (ridges and recesses) of the mesh conveyer is imprinted onto the surface layer of the multilayered fibrous material.
[0022] ( 2 b ) Mold Based Method
[0023] Referring to FIG. 14, the problems associated with methods for forming a fibrous aggregate using a mold will be described. FIG. 14 is a drawing for depicting the state of the inside of a mold during the production of a fibrous aggregate using a mold.
[0024] As the mold 700 begins to be heated after the multilayered fibrous material block 610 is packed into the mold 700 and the mold 700 is sealed with the lid 710 , the multilayered fibrous material block 610 begins to gradually collapse in the gravity direction starting from its fringe. This phenomenon is not conspicuous when the plural types of fibers in the multilayered fibrous material block 610 are very different in melting point, for example, when one group of of fibers in the multilayered fibrous material block 610 is formed of polyethylene, and the other group of fibers is formed of polypropyleneterephthalate. However, if the two groups of fibers are selected from among olefinic materials alone, the phenomenon becomes very conspicuous. This may be due to the fact that in this case, there is little difference in melting point between the two groups of fibers, and therefore, the effects of the heat transmitted from the mold 700 first manifest in the fringe portions of the multilayered fibrous material block 610 .
[0025] As the heating of the mold 700 is continued, heat is conducted all the way to the center of the multilayered fibrous material block 610 , causing the entirety of the adjacencies of the bottom surface of the multilayered fibrous material block 610 to collapse as shown in FIG. 14( b ). When the multilayered fibrous material block 610 is in this state, the bulk density of the multilayered fibrous material block 610 is nonuniform in terms of the gravity direction; the top portion of the multilayered fibrous material block 610 is lower in bulk density than the bottom portion of the multilayered fibrous material block 610 because the bottom side of the multilayered fibrous material block 610 is more affected by the weight of the multilayered fibrous material block 610 itself. In other words, a high bulk density region 610 a and a low bulk density region 610 b coexist in the multilayered fibrous material block 610 ; an undesirable bulk density gradient has been created.
[0026] As described before, in the case of a conventional mold based method, bulk density gradient occurs, and therefore, a fibrous aggregate block which is relatively high in hardness and bulk density, such as the one formable by a conventional heated air conveyer heating chamber based method, can be easily formed, but a soft and thick fibrous aggregate block which is uniform and low in bulk density is difficult to produce.
[0027] Further, across the portions of the internal surface of the mold 700 , with which the fibers come into contact, melted fibers (fibers which have the relatively low melting point and act as bonding agent) spread flat. As a result, a porous skin, which is smaller in porosity than the internal portion of the multilayered fibrous material block 610 , is formed in a manner to wrap the multilayered fibrous material block 610 along the internal surface of the mold 700 . Depending upon the type of fibrous aggregate usage, the presence of this skin is undesirable, and therefore, a process for removing the skin becomes necessary, which is a problem in that the removal of the skin reduces yield relative to the amount of raw material.
SUMMARY OF THE INVENTION
[0028] The primary object of the present invention is to provide a method and an apparatus which are capable of forming a thicker fibrous aggregate which is low and uniform in bulk density, in particular, a method and an apparatus which are capable of forming such a fibrous aggregate even when the fibers in the multilayered fibrous material used for the formation of a fibrous aggregate are the same in properties, are not very different in melting point, and/or are relatively low in melting point.
[0029] A fibrous aggregate forming method in accordance with the present invention for accomplishing the above described objects is a method for thermally processing fibrous material to form a fibrous aggregate, and comprises: a heating process in which heated air is blown upward through the fibrous material from below the fibrous material to melt at least a portion of each fiber of the predetermined group of fibers in the fibrous material, while keeping the fibrous material afloat and in the same state as it was prior to the blowing of the heated air; a compressing process in which the heated fibrous material is compressed to a desired thickness from the top and bottom sides; and a cooling process in which the fibrous material is cooled to solidify the melted portion of each fiber, so that the fibers are firmly welded to each other at their intersections.
[0030] A fibrous aggregate forming apparatus in accordance with the present invention is an apparatus for thermally processing a fibrous material to form a fibrous aggregate, and comprises: a supporting means on which the aforementioned fibrous material is mounted; a heated air flow generating means for blowing the heated air for the heating process for melting at least a portion of each fiber, upward from below the fibrous material to lift and keep afloat the fibrous material from the supporting means; a compressing means for compressing the fibrous material toward the supporting means; and an attitude controlling means for controlling the attitude of the fibrous material kept afloat by the heated air.
[0031] According to one of the aspects of the present invention, while the fibrous material is thermally processed, it is lifted and kept afloat by blowing heated air upward at the fibrous material from directly below the fibrous material, and the attitude of the fibrous material kept afloat is regulated. As a result, the effect of the gravity which affects formation of fibrous aggregate is eliminated, and therefore, relatively thick fibrous aggregate which is relatively low in bulk density can be easily obtained.
[0032] In particular, a ventilatory sheet is placed in contact with the top and bottom surfaces of the fibrous material, and therefore, the surface pattern of the members used to compress the fibrous material is not imprinted onto the skin layer, or the top layer, of the fibrous material.
[0033] These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] [0034]FIG. 1 is a schematic sectional view of the heating heating chamber for forming a fibrous aggregate, in the first embodiment of the present invention.
[0035] [0035]FIG. 2 is a sectional view of an example of a strand of fiber in the fibrous material in accordance with the present invention.
[0036] [0036]FIG. 3 is a schematic drawing for depicting a method for forming a block of fibrous aggregate using the heating heating chamber illustrated in FIG. 1, and shows the state in which the dies are placed in contact with the top and bottom surfaces of the multilayered fibrous material block, one for one.
[0037] [0037]FIG. 4 is a schematic drawing for depicting a method for forming a block of fibrous aggregate using the heating heating chamber illustrate in FIG. 1, and shows the positional relationship between the bottom mold set in the heating heating chamber, and the top mold.
[0038] [0038]FIG. 5 is a schematic drawing for depicting a method for forming a block of fibrous aggregate using the heating heating chamber illustrate in FIG. 1, and shows the state in which heated air is being blown at the multilayered fibrous material from below.
[0039] [0039]FIG. 6 is a graph which shows the characteristic, in terms of temperature increase, of a block of multilayered fibrous material formed of such fiber that has a core portion and a sheath portion, which are formed of polypropylene and polyethylene, respectively.
[0040] [0040]FIG. 7 is a schematic drawing for depicting a method for forming a block of fibrous aggregate using the heating heating chamber illustrated in FIG. 1, and shows the state in which the block of layers of fibers is being compressed by the top and bottom dies.
[0041] [0041]FIG. 8 is a schematic drawing for depicting a method for forming a block of fibrous aggregate using the heating heating chamber illustrated in FIG. 1, and shows the state in which the ventilatory sheets are being peeled away after the completion of the compressing process and cooling process.
[0042] [0042]FIG. 9 is a perspective view of a block of fibrous aggregate formed with the use of the heating heating chamber illustrated in FIG. 1.
[0043] [0043]FIG. 10 is a schematic sectional view of the a fibrous aggregate forming apparatus in the second embodiment of the present invention.
[0044] [0044]FIG. 11 is a schematic sectional view of the fibrous aggregate forming apparatus illustrated in FIG. 10, at a plane indicated by a line A-A.
[0045] [0045]FIG. 12 is a schematic sectional view of a conventional heated air conveyer heating chamber used for a thermal molding method.
[0046] [0046]FIG. 13 is a drawing for depicting a method for forming a block of fibrous aggregate using a conventional mold based method.
[0047] [0047]FIG. 14 is a drawing for describing the problems in a conventional mold based fibrous aggregate forming method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] Next, the preferred embodiments of the present invention will be described with reference to the appended drawings.
[0049] (Embodiment 1)
[0050] [0050]FIG. 1 is a schematic sectional view of the heating heating chamber for forming a fibrous aggregate, in the first embodiment of the present invention.
[0051] The heating heating chamber 10 depicted in FIG. 1 contains a heated air flow generating unit 11 for generating a flow of heated air. The heated air flow generating unit 11 is located in the bottom portion of the heating heating chamber 10 , and has: a plurality of heating rods 12 for generating heat; an air blowing fan 13 which is located below the heating rods 12 to generate upward heated air flow; and a perforated stainless steel plate 14 located above the heater 12 . With this structural arrangement, as the air within the heating heating chamber 10 is blown upward by the air blowing fan 13 , and is heated by the heating rods 12 . Then, the heated air flow is uniformly diffused as it passes through the perforated plate 14 . After passing through the perforated plate 14 , the heated air hits the top wall of the heating heating chamber, moves downward through a return path 15 , and is suctioned by the air blowing fan 13 , being again blown upward to circulate through the heating heating chamber 10 . The internal temperature of the heating heating chamber 10 is kept constant by an unillustrated controlling means.
[0052] Located above the heated air flow generating unit 11 is a molding unit 20 which holds a block 50 of multilayered fibrous material from the top and bottom sides. The molding unit 20 has top and bottom dies 22 and 21 , which are structured so that they can be placed in, or removed from, the heating heating chamber 10 , independently of each other. The top die 22 is supported by a top die guide 26 which can be moved upward or downward by an unillustrated driving means, so that the top die 22 can be moved up or down in the heating heating chamber 10 . The left half of FIG. 1 shows the state in which the top die 22 has been moved upward, whereas the right half shows the state in which the top die 22 has been moved downward. The top and bottom dies 22 and 21 are structured so that heated air can be passed upward through them as will be described later, and also so that they do not deform when compressing the multilayered fibrous material 50 . Therefore, the top and bottom dies 22 and 21 are perforated stainless steel plates.
[0053] Here, the multilayered fibrous material 50 will be described. The multilayered fibrous material 50 is a block of multilayered webs of fibers, and the fibers are extended more or less in parallel. It is produced using a carding machine (unillustrated), a cross-layer machine (unillustrated), or the like. The weight per unit of area, of the multilayered fibrous material 50 is determined depending on the usage of the finished product. It is given a predetermined size. The direction in which the webs are stacked is parallel to the gravity direction, and coincides with the vertical direction in FIG. 1. The direction in which fibers are extended is approximately perpendicular to the direction in which the webs are stacked, and coincides with the left-to-right direction, or the front-to-rear direction, in FIG. 1. In this embodiment, a large sheet of multilayered fibrous material, which is produced using the aforementioned carding machine, a cross-laying machine, or the like, is cut into approximately square pieces having a dimension of an approximately 1,000 mm x approximately 1,000 mm, and these pieces are used as the multilayered fibrous material blocks 50 . It should be noted here that it is not always necessary that the multilayered fibrous material 50 is directional; the fibers in the multilayered fibrous material 50 may extend in random directions. The bulk density of the multilayered fibrous material 50 is desired to be approximately uniform.
[0054] As for the material for the fibers 51 in the multilayered fibrous material 50 , a type of fiber structured of two portions: core portion 51 a of polypropylene, and sheath portion 51 b of polyethylene which sheaths the core portion 51 a , as shown in FIG. 2, is used as the fiber in this embodiment (hereinafter, sheathed fiber). The melting point of polypropylene is approximately 180° C., and the melting point of polyethylene is approximately 130° C. Therefore, the difference in melting point between the two materials is approximate 50° C. As for fiber diameter, fiber with a diameter of 5 μm to 50 μm is generally used. In this embodiment, fiber with a diameter of approximately 18 μm (2 deniers) is used.
[0055] Although the above described sheathed fiber 51 is used in this embodiment, the fiber structure does not need to be limited to this structure. For example, a blend between pure polypropylene fiber and pure polyethylene fiber, or a blend between sheathed fiber formed of polypropylene and polyethylene, and pure fiber, may be used. When the sheathed fiber 51 is used, the polyethylene is present at all intersections among the fibers, and therefore, virtually all fibers are securely fixed to the fibers in contact with them, at their intersections. As a result, sturdy fibrous aggregate is produced. When a blend between polyethylene fibers and polypropylene fibers is used, the ratio at which the fibers are fixed to the fibers in contact with them, at their intersections, varies depending on the blending ratio between the polyethylene fibers and polypropylene fibers. In other words, the fiber fiber-to-fiber fixation occurs only at the intersections where a polyethylene fiber is in contact with another polyethylene fiber. Thus, employment of the above described blend is useful to obtain relatively soft fibrous aggregate. Further, even though polyethylene and polypropylene are used as the material for the fibrous aggregate in this embodiment, fiber selection is not limited to the one in this embodiment, as long as a plurality of selected fibers are different in melting point from each other. Further, the number of different fibers does not need to be two; it may be three or more.
[0056] Next, the fibrous aggregate forming method which uses the heating heating chamber 10 illustrated in FIG. 1 will be described with reference to a case in which fibrous aggregate with an apparent density of 0.038-0.043 g/cm 3 and a thickness of 35 mm is formed.
[0057] (1-1) Preparatory Process
[0058] In order to form fibrous aggregate with an apparent density of 0.038-0.043 g/cm 3 and a thickness of 35 mm using the aforementioned sheathed fibers, the thickness of the multilayered fibrous material block 50 after it is prepared, that is, after fiber stand webs are vertically stacked, are lightly compacted down, and are relieved of pressure, is desired to be approximately 120 mm (100-150 mm). In this embodiment, therefore, the multilayered fibrous material block 50 with a thickness of 120 mm was used.
[0059] Referring to FIG. 3, first, the bottom die 21 is removed from the heating heating chamber 10 (FIG. 1), and a ventilatory sheet 23 is spread on the bottom die 21 . Then, the multilayered fibrous material block 50 is placed on the ventilatory sheet 23 . The edge portions of the ventilatory sheet 23 are anchored to the bottom die 21 with weighting blocks 24 . In order to assure that there will be a sufficient amount of margin used by the weighting blocks 24 to anchor the ventilatory sheet 23 , and also in order to allow the ventilatory sheet 24 to float from the bottom die 21 during the heating process which will be described later, the size (size of the entirety of the surface on which multilayered fibrous material block 50 is placed) of the ventilatory sheet 24 is rendered sufficiently large compared to the size of the exact portion of the surface of the ventilatory sheet 24 , on which the multilayered fibrous material block 50 is placed.
[0060] On the top surface of the multilayered fibrous material block 50 , a ventilatory sheet 25 similar to the ventilatory sheet 24 is placed. The size of this ventilatory sheet 5 is approximately the same as the size of the top surface of the multilayered fibrous material block 50 . Of the two ventilatory sheets 23 and 25 , the bottom ventilatory sheet 23 is required to retain the multilayered fibrous material block 50 during the heating process which will be described later, and therefore, it is required that the ventilatory sheet 23 is capable of sufficiently engaging or entangling with the fibers of the multilayered fibrous material block 50 , and also capable of stretching or shrinking in an environment in which heat is applied. If the fibers of the multilayered fibrous material block 50 do not entangle with the ventilatory sheet 23 , when the multilayered fibrous material block 50 is made to float, it becomes separated from the ventilatory sheet 23 ; the ventilatory sheet 23 fails to remain in contact with the multilayered fibrous material block 50 .
[0061] On the other hand, the top die 22 (FIG. 1) has been set in advance in the heating heating chamber 10 . In this state, it is desired that the top die 22 has been heated to a predetermined internal temperature of the heating heating chamber 10 , which will be described later. If the temperature of the top die 22 is too low, the fibers are rapidly cooled and solidify, making it impossible to uniformly compress the multilayered fibrous material block 50 , as the top die 22 comes into contact with the multilayered fibrous material block 50 in the compressing process which will be described later.
[0062] (1-2) Heating Process
[0063] After the multilayered fibrous material block 50 is mounted on the bottom die 21 as described above, the bottom die 21 on which the multilayered fibrous material block 50 is mounted is set in the heating heating chamber 10 . At this stage, the position of the top die 22 is such that as the multilayered fibrous material block 50 is set in the heating heating chamber 10 , a gap is created between the multilayered fibrous material block 50 and the top die 22 , as shown in FIG. 4. Further, the interior of the heating heating chamber 10 has been heated in advance to a desirable temperature. As described before, the multilayered fibrous material block 50 is formed of the aforementioned sheathed fiber, that is, fiber having core and sheath portions formed of polypropylene and polyethylene, respectively, and therefore, the temperature to which the interior of the heating heating chamber 10 is to be heated has only to be between the melting point (approximately 130° C.) of the polyethylene and the melting point (approximately 180° C.) of polypropylene, and also higher than the softening point (approximately 120° C.) of the polypropylene. In this embodiment, the interior of the heating heating chamber 10 was set to 140° C.
[0064] After setting the bottom die 21 in the heating heating chamber 10 , the air blowing fan 13 is driven to blow heated air toward the multilayered fibrous material block 50 from below the multilayered fibrous material block 50 to heat the multilayered fibrous material block 50 . The air blowing fan 13 is set so that the velocity of the upward air flow generated by the air blowing fan 13 becomes 0.3-0.8 m/sec. As described before, the bottom and top dies 21 and 22 are formed of perforated plate, and the multilayered fibrous material block 50 is sandwiched by the top and bottom ventilatory sheets 23 and 25 . Therefore, the heated air is more uniformly passed through the multilayered fibrous material block 50 . Incidentally, in order to prevent the bottom and top dies 21 and 22 from interfering with the ventilatory performance of the ventilatory sheet 23 and 25 , the sizes and densities of the perforations of the bottom and top dies 21 and 22 are selected so that the ventilatory performances of the bottom and top dies 21 and 22 become approximately the same as, or greater than, those of the ventilatory sheets 23 and 25 . The air blowing fan 13 is driven to generate such a heated air flow that is capable of keeping the multilayered fibrous material block 50 afloat above the bottom die 21 , against the gravity G, in such a manner that the multilayered fibrous material block 50 remains in contact with the top die 22 without being compressed thereby. In other words, the fibers themselves are kept afloat by the heated air from below, while the multilayered fibrous material block 50 is being held by the top die 21 by the top surface. Therefore, the effect of the gravity which affects each fiber is reduced. Further, the interposition of the ventilatory sheet 25 between the top surface of the multilayered fibrous material block 50 and the top die 22 prevents the bulk density of the top layer of the multilayered fibrous material block 50 from becoming locally high. In other words, with the provision of the above described heating arrangement, the multilayered fibrous material block 50 can be heated while keeping the multilayered fibrous material block 50 virtually before heating.
[0065] As described above, the multilayered fibrous material block 50 is caused to float by the heated air. However, the fiber stands of the multilayered fibrous material block 50 have sufficiently entangled with the ventilatory sheet 23 , and further, the edge portions of the ventilatory sheet 23 are anchored to the bottom die 21 by the weighting blocks 24 . Therefore, the ventilatory sheet 23 balloons as shown in FIG. 5; the amount of the lift of the multilayered fibrous material block 50 and the attitude of the multilayered fibrous material block 50 are regulated by the ventilatory sheet 23 as the multilayered fibrous material block 50 is lifted by the heated air. By regulating the position and attitude of the multilayered fibrous material block 50 while the multilayered fibrous material block 50 is kept afloat by the heated air, it is assured that the multilayered fibrous material block 50 is uniformly heated by the heated air.
[0066] If the weighting blocks 24 are not used, the following problems occur. That is, if the velocity of the heated air blown upward from directly below the multilayered fibrous material block 50 is excessively high, the multilayered fibrous material block 50 is pressed against the top die 22 with excessive force, and therefore, the bulk density of the top portion of the multilayered fibrous material block 50 becomes greater than that of the bottom portion of the multilayered fibrous material block 50 . On the other hand, if the heated air velocity is excessively low, the multilayered fibrous material block 50 fails to be lifted, and the fibers softened by the heated air droop downward, causing the bulk density in the bottom portion of the multilayered fibrous material block 50 to become greater than that in the top portion of the multilayered fibrous material block 50 . In either case, unless the heated air is blown upward at a proper velocity, the bulk density of the multilayered fibrous material block 50 will not turn out to be uniform after the heating. Incidentally, if it is possible to control the heated air velocity so that the multilayered fibrous material block 50 is lifted and kept afloat, and the entirety of the top surface of the multilayered fibrous material block 50 remains virtually evenly in contact with the top die 22 without causing the top portion of the multilayered fibrous material block 50 to be compressed against the top die 22 , the weighting blocks 24 are not necessarily required.
[0067] Further, the ventilatory sheet 23 is entangled with the fibers of the multilayered fibrous material block 50 to a proper degree, which in turn increases the frictional resistance between the ventilatory sheet 23 and multilayered fibrous material block 50 . Therefore, it is difficult for the multilayered fibrous material block 50 to horizontally shift relative to the ventilatory sheet 23 . Thus, the multilayered fibrous material block 50 is prevented from being shifted, stretched, or compressed by external physical force during this heating process, compressing process, and cooling process. As a result, a block of fibrous aggregate uniform in density is produced.
[0068] Regarding the above described lifting and keeping afloat of the multilayered fibrous material block 50 , at least the opposing two edge portions of the ventilatory sheet 23 placed in contact with the polygonal flat bottom surface of the multilayered fibrous material block 50 are prevented from lifting, by being anchored by the weighting blocks 24 , and since the ventilatory sheet 23 is ballooned upward by the heated air, the multilayered fibrous material block 50 on the ventilatory sheet 23 is actually lifted and kept afloat from the bottom die 21 . Therefore, the upward flow of the heated air is prevented from escaping from the lateral sides of the multilayered fibrous material block 50 . As a result, the bulk density of the multilayered fibrous material block 50 remains as desirable as possible in terms of the horizontal direction as well as the vertical direction, that is, the direction of thickness, almost to the surfaces of the multilayered fibrous material block 50 .
[0069] At this time, the characteristic, in terms of temperature increase, of the multilayered fibrous material block 50 formed of such sheathed fiber that has a polypropylene core and a polyethylene sheath will be described. FIG. 6 is a graph which shows the characteristic of the multilayered fibrous material block 50 in terms of temperature increase. In FIG. 6, the axis of ordinates represents temperature, and the axis of abscissas represents elapsed heating time.
[0070] As the multilayered fibrous material block 50 is placed in the heating heating chamber 10 which has been heated to a target temperature of S 3 which is lower than the melting point S 2 (approximately 180° C.) of the polypropylene, the temperature of the multilayered fibrous material block 50 rises to the melting point S 1 (approximately 130° C.) after the elapse of a time T 1 . As the temperature of the multilayered fibrous material block 50 reaches S 1 , the polyethylene begins to melt, and the temperature of the multilayered fibrous material block 50 remains at S 1 until the polyethylene, that is, the material of the sheath portion, completely melts.
[0071] Then, after the passage of a time T 2 , that is, as the polyethylene completely melts, temperature of the multilayered fibrous material block 50 again begins to rise, and reaches the target temperature S 3 of the heating heating chamber 10 after the elapse of a time T 3 . Since the temperature S 3 has been set to be lower than the melting point S 2 of the polypropylene, it does not occur that polypropylene melts and allows the structure of the multilayered fibrous material block 50 to collapse.
[0072] In the case of the multilayered fibrous material block 50 in this embodiment, the size of which is 1,000 mm×1,000 mm, the proper lengths of T 1 , T 2 , and T 3 are 10-15 minutes, 10-20 minutes, and 20-25 minutes, correspondingly.
[0073] In this process, causing the fibrous material block 50 to float, is advantageous irrespective of the use of the ventilatory sheet 23 . If the fibrous material block 50 is not caused to float, the state of being heated is different between adjacent the opened portions and adjacent the closed portions of the die 21 , which is the perforated plate of stainless steel in this embodiment. the heated air passes through the opened portions, and therefore, the portions adjacent the openings is more quickly heated with the result that the temperature distribution in the fibrous material block 50 is not uniform, and the produced fibrous material may be non-uniform. However, by causing the fibrous material block 50 to float as with this embodiment, there is provided a gap between the bottom die 21 and the bottom portion of the fibrous material block 50 . The perforations and the gap function like a damper such that the hot air can relatively uniformly hit the bottom of the fibrous material block 50 to uniformly heat the block 50 . Thus, a uniform fibrous material block can be produced.
[0074] (1-3) Compressing Process
[0075] Referring to FIG. 7, after the entirety of the multilayered fibrous material block 50 is satisfactorily heated, the top die 22 is lowered to compress the multilayered fibrous material block 50 to a predetermined thickness (bulk density). At this stage, it is desired that the top die 22 has been heated to approximately the same temperature as that of the multilayered fibrous material block 50 . This is for the following reason. If the temperature of the top die 22 is lower than the melting point of the polyethylene which acts as adhesive, the polyethylene in the topmost portion of the multilayered fibrous material block 50 solidifies, causing the fibers to be welded to the adjacent fibers. As a result, such a problem occurs that the bulk density of the top portion of the multilayered fibrous material block 50 becomes locally high; the bulk density of the top portion of the multilayered fibrous material block 50 becomes undesirably higher than that of the rest.
[0076] In this compressing process, the heated air flow is not stopped, and therefore, the multilayered fibrous material block 50 is compressed while the gravity acting on each fiber is being cancelled by the flow. As a result, the multilayered fibrous material block 50 is compressed while maintaining uniform bulk density throughout its entirety. As the multilayered fibrous material block 50 is compressed, the bulk density of the multilayered fibrous material block 50 gradually increases, making it more difficult for the heated air to pass through the multilayered fibrous material block 50 , and for heat to conduct through the multilayered fibrous material block 50 . Thus, it is desired that while compressing the multilayered fibrous material block 50 , the heated air flow is slightly reduced. This is for the following reason. As the bulk density increases, the increased bulk density decreases the ventilability and thermal conductivity of the multilayered fibrous material block 50 , which in turn causes the entirety of the multilayered fibrous material block 50 to be blown upward and pressed against the top die 22 by the heated air flow, resulting in the problem that the bulk density of the top portion of the multilayered fibrous material block 50 locally increases, or the like problems. In this embodiment, the velocity of the heated air flow in the compressing process was set to 0.2-0.4 m/sec.
[0077] As for the compression speed (the speed at which the top die 22 in this embodiment is lowered), it matters very little when it is intended to obtain a fibrous aggregate block with high bulk density (0.15 g/cm 3 or more). However, when it is intended to obtain a fibrous aggregate block with a low bulk density, it is desired that the multilayered fibrous material block 50 is compressed at a slower speed. This is for the following reason. If the compression speed is high, before the entirety of the multilayered fibrous material block 50 is compressed, the bulk density of the multilayered fibrous material block 50 increases on the side in contact with the top die 22 , and the fibers on this side are welded to each other while the bulk density of this side remains high. As a result, the problem that the bulk density of the top portion locally increases, or the like problems, occur.
[0078] Obviously, it is desired that also during the compressing process, the top die 22 is lowered from straight above while keeping afloat the multilayered fibrous material block 50 by blowing the heated air upward from directly below the multilayered fibrous material block 50 .
[0079] (1-4) Cooling Process
[0080] After compressing the multilayered fibrous material block 50 to the predetermined thickness, the top and bottom dies 22 and 21 are removed from the heating heating chamber 10 , with the multilayered fibrous material block 50 remaining compressed between the two dies, and the entirety of the two dies 22 and 21 and the multilayered fibrous material block 50 is cooled. During this cooling period, the top die 22 may be kept pressed toward the bottom die 21 with the use of a weight or the like, with a spacer (unillustrated) with a predetermined height being placed between the top and bottom dies 22 and 21 , so that the state in which the multilayered fibrous material block 50 has been kept compressed in the heating heating chamber 10 can be exactly maintained during the cooling period. As for the cooling method, any method will do: natural cooling, forced cooling by a cooling fan or the like. Further, the cooling may be done within the heating heating chamber 10 ; the interior of the heating heating chamber 10 is cooled without removing the top and bottom dies 22 and 21 from the heating heating chamber 10 .
[0081] After the temperatures of the surface layers of the multilayered fibrous material block 50 , that is, the temperatures of the top and bottom surfaces of the multilayered fibrous material block 50 in contact with the top and bottom dies 22 and 21 , respectively, drop below the melting point of the polyethylene, the multilayered fibrous material block 50 is separated from the top and bottom dies 22 and 21 , with the perforated sheets 23 and 25 remaining with the multilayered fibrous material block 50 . At this stage, the multilayered fibrous material block 50 has already turned into the multilayered fibrous aggregate block 55 (FIG. 9), that is, the multilayered fibrous material block 50 is practically the same as the fibrous aggregate block 55 , although the perforated sheets 23 and 25 are still firmly in contact with the multilayered fibrous material block 50 at this stage. Thus, after the cooling process, the multilayered fibrous material block 50 will be referred to as the fibrous aggregate block 55 .
[0082] After the separation of the top and bottom dies 22 and 21 from the fibrous aggregate block 55 , the perforated sheets 23 and 25 are peeled from the fibrous aggregate block 55 as shown in FIG. 8 to obtain the fibrous aggregate block 55 in the state depicted in FIG. 9.
[0083] By going through each of the above described processes, the fibrous aggregate block 55 with an apparent specific weight of 0.038-0.043 g/cm 3 and a thickness of 35 mm can be formed. The obtained fibrous aggregate block 55 is cut into smaller pieces of a predetermined size, or used in combination with other fibrous aggregate block 55 , depending on usage.
[0084] In the above description of this embodiment, the case in which the fibrous aggregate block 55 having the aforementioned apparent specific weight and the aforementioned thickness was formed using such sheathed fiber that has a polypropylene core and a polyethylene sheath, was stated. However, various manufacturing conditions such as the aforementioned internal temperature setting of the heating heating chamber 10 or velocity of the heated air flow are adjusted in accordance with the type, thickness, and physical properties of the fibrous aggregate block to be formed. According to the method used in this embodiment, a thick and uniform block of fibrous aggregate 55 having a bulk density ranging between 0.03-0.3 g/cm 3 , can be produced using a block of multilayered fibrous material 50 having a bulk density of approximately 0.02 g/cm 3 .
[0085] The thus formed fibrous aggregate block 55 possesses a proper amount of elasticity, and therefore, can be used as a preferable interior material for a seat, an armrest, a headrest, and the like for a passenger car, or a preferable cushioning material for such furniture that is represented by a bed and a sofa. Further, the fibrous aggregate block 55 is superior in water retention, and therefore, can be used as a preferable material for a water retaining member placed in various liquid containers in which various liquids are kept.
[0086] The fiber aggregate comprising fibers welded at the crosing points of fibers is advantageous over aggregated of non-welded fibers as follows.
[0087] When the aggregate is used of cushion, the shape may lose relatively easily, and the cushion performance varies since the fibers slide in response to the external pressure relative to each other because of the fibers are not fixed to each other at the crossing points. According to the present invention, the positional relationships among the fibers hardly changes evey by pressure, and therefore, the shape can be maintained, and the cushion perfromance can be maintained.
[0088] When the aggregate is used as water-retaining material, the fibers may become non-uniform due to impact or water absorbing action with the result of bulk density of the aggregate changes so that the intended water-retaining performance is not provided. By welding the fibers at the crossing points, these problems can be avoided.
[0089] Furthermore, according to the present invention, a welded fiber aggregate having a low bulk density and large thickness can be provided. The low limit of the density changes with the diameter (denier) of the fiber. Generally, the difficuly of production becomes greater with increase of the thickness. According to the present invention, such a low density fiber aggregate as 0.025 g/cm 3 with the thickness of 45 mm or 0.03 g/cm 3 with the thickness of 60 mm could be produced. With conventional methods, it has been difficult to produce the aggregate of 0.06 g/cm 3 in density. According to the present invention, the fiber aggregate having the density of not less than 0.03 g/cm 3 can be easily produced when the thickness is not less than 15 mm and not more than 60 mm. Such a low density fiber aggregate is advantageous in that the degree of deformation against the pressure is large, and therefore, it can be used for sheet of car or cushins for furniture, or packing materials particularly for ornaments of precious metal, jewels, fragile materials or the like, for which cushion of less elasticity and high restoring performance is desired.
[0090] As described above, according to the fibrous aggregate forming method in this embodiment which employs the heating heating chamber 10 , heated air is blown upward at the multilayered fibrous material block 50 , which has not been compressed, from below the multilayered fibrous material block 50 during the heating process, and therefore, the heated air smoothly climbs through the multilayered fibrous material block 50 while exchanging heat with the multilayered fibrous material block 50 , efficiently heating the multilayered fibrous material block 50 and therefore reducing the heating time. Consequently, a thick block of fibrous aggregate which is low in bulk density can be formed.
[0091] At this time, the description of the perforated sheets 23 and 25 will be supplemented.
[0092] As described before, the perforated sheet 23 on the bottom side effectively contributes to produce a thick sheet of fibrous aggregate block 55 which is low and uniform in bulk density, by preventing the multilayered fibrous material block 50 from becoming separated from the bottom die 21 during the heating process. When only this aspect of the fibrous aggregate production is taken into consideration, the perforated sheet 25 on the top side is unnecessary. However, the perforated top sheet 25 contributes to preventing the top surface of the multilayered fibrous material block 50 from being disturbed while the multilayered fibrous material block 50 is kept afloat and heated, and also to prevent such a phenomenon that an unintended bulk density distribution is created in the multilayered fibrous material block 50 by the sudden conduction of heat from the heated top die 22 . In addition, in consideration of the compressing process, which comes after the heating process, and in which the multilayered fibrous material block 50 is compressed by the top and bottom dies 22 and 21 while polyethylene is in the melted state, if the perforated sheets 23 and 25 are not used, the textures of the surfaces of the top and bottom dies 22 and 21 are imprinted onto the multilayered fibrous material block 50 , and as a result, the top and bottom surface layers of the multilayered fibrous material block 50 are turned into the so-called skin layers. The interposition of the perforated sheets 23 and 25 between the two members used for compressing the multilayered fibrous material block 50 is effective to prevent the formation of these skin layers.
[0093] As is evident from the above description, the material for the perforated sheets 23 and 25 is desired to be such a material that is capable of sufficiently entangling with the fibers of the multilayered fibrous material block 50 , is capable of stretching or shrinking in the heated environment, and does not melt during the heating process. Further, since the textures of the surfaces of the perforated sheets 23 and 25 are imprinted, to no small extent, on the surfaces of the multilayered fibrous material block 50 , the material sheet for the perforated sheets 23 and 25 is desired to be such a material sheet that is similar to the inner portion of the multilayered fibrous material block 50 in terms of the porosity. Thus, in this embodiment, a foamed polyurethane sheet with a cell count of approximately 16/cm was used as the material sheet for the perforated sheets 23 and 25 .
[0094] Materials in the form of a sheet, for example, a sheet of foamed polyurethane, produced by removing cell membranes after foaming, are not much different from the multilayered fibrous material block in terms of local difference in air-flow resistance at the cell level (approximately 300-600 μm) between the areas with high air-flow resistance and the areas with low air-flow resistance. Depicted two dimensionally, the multilayered fibrous material can be compared to a large room formed by removing all the walls of a plurality of contiguous small rooms (pillars can be compared to fibers). However, if the cells of the urethane sponge are compared to the rooms of a building, the rooms are different in size (cell size). In addition, some of the walls have been removed, but the other have not been removed, hindering the traffic through the building (increasing air-flow resistance). Positioning a sheet of foamed material, as the ventilatory sheet, in contact with the top or bottom surface of the multilayered fibrous material provides an effect of rectifying air flow across the entire surface through which the heated air flows.
[0095] Generally speaking, synthetic fibers are coated with various oily substances to provide them with convergence and smoothness, to prevent static electricity generation, or the like purposes; oily substances are adhered to them during a spinning process. However, in the fields of medicine or precise machinery, the oily substances are extremely disliked in some cases. In such cases, the amount of the oily substances must be reduced to an extremely low level. If the present invention is applied to such fibers, various problems that fibers entangle among themselves in an unintended manner, that bulk density becomes disturbed, and the like, occur sometimes in the presence of static electricity. Thus, it is desired as a countermeasure to such problems that the entirety of the webs are subjected to discharging blow when manufacturing fibrous aggregate. Further, a process in which ion exchange water or a water solution of nonionic surfactant is sprayed onto fibers may be provided in addition to the discharging blow process. The addition of such a process may be also very effective.
[0096] (Embodiment 2)
[0097] [0097]FIG. 10 is a schematic sectional view of the fibrous aggregate forming apparatus in the second embodiment of the present invention, and FIG. 11 is a schematic sectional view of the apparatus illustrated in FIG. 10, at a plane indicated by a line A-A in FIG. 10.
[0098] In the fibrous aggregate forming apparatus in this embodiment, fibrous aggregate is formed by moving a unit of continuous multilayered fibrous material 150 sandwiched by ventilatory sheets 111 and 112 from the top and bottom sides, from the right side of the drawing to the left side, with the use of first to third mesh belts 101 , 102 , and 103 , in the housing of the heating heating chamber 100 .
[0099] The first mesh belt 101 is in the bottom side of the heating heating chamber 100 . The first mesh belt 101 extends across the entire range through which a unit of continuous multilayered fibrous material 150 is moved. After being fed into the heating heating chamber 100 , the unit of continuous multilayered fibrous material 150 is carried on the first mesh belt 101 and moved in the left direction indicated in the drawing through the heating heating chamber 100 , and then is discharged from the heating heating chamber 100 . Regarding the direction in which the unit of continuous multilayered fibrous material 150 is moved, a feeding conveyer is located on the upstream side of the first mesh belt 101 , and a discharging belt is located on the downstream side of the first mesh belt 101 . The vertical level at which the first mesh belt 101 conveys the unit of continuous multilayered fibrous material 150 coincides with the vertical levels at which the feeding and discharging conveyers convey the unit of continuous multilayered fibrous material 150 . With the provision of this arrangement, the unit of continuous multilayered fibrous material 150 can be smoothly transferred onto the first mesh belt 101 from the feeding conveyer, and then can be smoothly transferred out onto the discharging conveyer from the first mesh belt 101 ; in other words, the unit of continuous multilayered fibrous material 150 can be continuously moved. As for a preferable material for the first mesh belt 101 , there is a metallic belt with an approximate mesh number of 4 mesh/cm, for example.
[0100] The unit of continuous multilayered fibrous material 150 is fed into the heating heating chamber 100 , with its bottom and top surfaces being covered with ventilatory sheets 111 and 112 which are placed in contact with the corresponding surfaces. Referring to FIG. 11, the ventilatory sheet 111 placed in contact with the bottom surface of the unit of continuous multilayered fibrous material 150 is wider than the unit of continuous multilayered fibrous material 150 , and the opposing edge portions of the ventilatory sheet 111 extending beyond the corresponding edges of the unit of continuous multilayered fibrous material 150 are held to the first mesh belt 101 with the use of anchoring members 113 . The width of the ventilatory sheet 112 placed on top of the unit of continuous multilayered fibrous material 150 is the same as that of the unit of continuous multilayered fibrous material 150 . The material and structure of the unit of continuous multilayered fibrous material 150 , and the materials and structures of the ventilatory sheets 111 and 112 , in this embodiment, are the same as those in the first embodiment.
[0101] The interior of the heating heating chamber 100 has two separate sections: a heating section 120 on the upstream side, and a cooling section 140 on the downstream side, in terms of the direction in which the unit of continuous fibrous material 150 is moved.
[0102] First, the heating section will be described. The heating section 120 has the second mesh belt 102 , which is positioned above the first mesh belt 101 in a manner to oppose the first mesh belt 101 . The second mesh belt 102 is rotated at the same velocity as that of the first mesh belt 101 and in synchronism with the first mesh belt 101 . It guides the unit of continuous multilayered fibrous material 150 , directly bearing down on the ventilatory sheet 112 , as the unit of continuous multilayered fibrous material 150 is moved by the first mesh belt 101 . The second mesh belt 102 is vertically movable by an elevating mechanism (unillustrated), for example, a hydraulic cylinder or the like, and its distance from the first mesh belt 101 has been adjusted to be greater than the thickness of the unit of continuous multilayered fibrous material 150 inclusive of the ventilatory sheets 111 and 112 , so that the top surface of the unit of continuous multilayered fibrous material 150 comes into contact with the second mesh belt 102 only when the unit of continuous multilayered fibrous material 150 is made airborne above the first mesh belt 101 . As for the preferable material for the second mesh belt 102 , there is metallic belt with an approximate mesh number of 4 mesh/cm, for example.
[0103] There are a first air sending chamber 122 and a first air receiving chamber 121 a certain distance below and above, respectively the passage through which the unit of continuous multilayered fibrous material 150 is moved by the first and second mesh belts 101 and 102 . The first air sending chamber 122 has an air supplying holes 122 a which open in the side wall of the first air sending chamber 122 , and a large number of perforations 122 b which are in the top wall of the first air sending chamber 122 , being evenly distributed. The structure of the first air receiving chamber 121 is similar to that of the first air sending chamber 122 ; air suctioning holes 121 a are in the side wall, and a large number of perforations 121 b are in the bottom wall, being evenly distributed. Referring to FIG. 10, a pair of conveyer rollers 102 a around which the second mesh belt 102 is suspended appear as if they are in the air receiving chamber 121 . However, they are positioned outside the air receiving chamber, one on each side, as shown in FIG. 11, and therefore, they do not affect the heated air flow from the air supplying holes 122 a which will be described later.
[0104] Referring to FIG. 11, the air suctioning holes 121 a and air supplying holes 122 a are connected to a heated air flow generating machine 105 by way of corresponding air ducts. The heated air flow generating machine 105 contains a heater 107 , and an air blowing fan 106 which generates air flow which flows from the air suctioning hole 121 a side toward the air suctioning hole 122 a side. As the heated air flow generating machine 105 is driven, heated air flow which flows towards the supplying holes 122 a is generated in the heated air flow generating machine 105 . This heated air is sent into the air sending chamber 122 through the air supplying holes 122 a , and is blown into the unit of continuous multilayered fibrous material 150 from directly below through the perforations 122 b . After being blown into the unit of continuous multilayered fibrous material 150 , the heated air travels upward through the unit of continuous multilayered fibrous material 150 , is suctioned into the air receiving chamber 121 through the perforations 121 b , and is returned into the heated air flow generating machine 105 through the air supplying holes 121 a . In other words, across the range across which the unit of continuous multilayered fibrous material 150 is moved, upward flow of heated air occurs.
[0105] As will be described later, in this embodiment, in order to make it possible to allow heated air to be blown upward toward the unit of continuous multilayered fibrous material 150 even while the unit of continuous multilayered fibrous material 150 is compressed, the first air sending chamber 122 and first air receiving chamber 121 are extended into the areas below and above a pair of conveyer rollers 103 a , that is, the most upstream conveyer rollers, around which the third mesh belt 103 is suspended, respectively, in the cooling section 140 which will be described later. These conveyer rollers 103 a are also positioned outside the air receiving chamber 121 as the aforementioned pair of conveyer rollers 102 a , and therefore, they do not affect the flow of heated air from the air supplying holes 122 a.
[0106] Next, the cooling section 140 will be described. The basic structure of the cooling section 140 is the same as that of the heating section 120 . In other words, it has the third mesh belt 103 which is positioned above the first mesh belt 101 in a manner to oppose the first mesh belt 101 , a second air sending chamber 142 positioned below the path through which the unit of continuous multilayered fibrous material 150 is conveyed, and a second air receiving chamber 141 positioned above the path through which the unit of continuous multilayered fibrous material 150 is conveyed. However, this cooling section 140 must quickly cool the unit of continuous multilayered fibrous material 150 after the compression of the unit of continuous multilayered fibrous material 150 , and therefore, a cold air flow generating machine (unillustrated), instead of the aforementioned heated air flow generating machine, is connected to the second air sending chamber 142 and second air receiving chamber 141 .
[0107] The third mesh belt 103 is rotated at the same velocity as that of the first mesh belt 101 and in synchronism with the first mesh belt 101 . It guides the unit of continuous multilayered fibrous material 150 , bearing down on the ventilatory sheet 112 , as the unit of continuous multilayered fibrous material 150 is conveyed by the first mesh belt 101 . The third mesh belt 103 is vertically movable by an unillustrated elevating mechanism as is the second mesh belt 102 , and its distance from the first mesh belt 101 has been adjusted so that the unit of continuous multilayered fibrous material 150 is compressed to the thickness of a final product, or a unit of continuous fibrous aggregate. A preferable material for the first mesh belt 101 is a metallic belt with an approximate mesh number of 4 mesh/cm, for example.
[0108] The second air sending chamber 142 has air supplying holes 142 a and perforations 142 b similar to the air supplying holes 122 a and perforations 122 b of the first air sending chamber 122 , and the cold air generated by the aforementioned cold air flow generating machine is blown upward from below the unit of continuous multilayered fibrous material 150 . The second air receiving chamber 141 has an air suctioning hole 141 a and perforations 141 b similar to the air supplying holes 121 a and perforations 121 b of the first air receiving chamber 121 , and the cold air is blown upward from the second air sending chamber 142 , is suctioned through the unit of continuous multilayered fibrous material 150 , and is returned into the cold air flow generating machine.
[0109] As for the cooling air to be blown through the heated unit of continuous multilayered fibrous material 150 in the cooling section 140 , air (ambient air) with normal temperature may be used. In such a case, the aforementioned cold air flow generating machine is structured as a simple air blower, which takes in air from outside the heating heating chamber 10 , and exhausts it from the second air receiving chamber 141 . With the provision of a blower or the like for forcefully exhausting the air within the second air receiving chamber 141 , at the air suctioning hole 141 a of the second air receiving chamber 141 , improvement in air exhausting efficiency can be expected.
[0110] At least one of the rollers around which the first and third mesh belts 101 - 103 are suspended is provided with a secondary heating means constituted of a piece of electrical heating wire or the like, and any given portions of the first to third mesh belts 101 - 103 are preheated to an approximately the same temperature as that necessary in the heating heating chamber 10 , before they come into contact with the unit of continuous multilayered fibrous material 150 .
[0111] More specifically, the temperature of a given portion of the first mesh belt 101 drops as it moves through the cooling section 140 , and therefore, this portion of the first mesh belt 101 is preheated to a predetermined temperature before it enters the heating section 120 , so that the efficiency with which the unit of continuous multilayered fibrous material 150 is heated in the heating section 120 is prevented from falling. The temperature of a given portion of the second mesh belt 102 also falls before it comes into contact with the unit of continuous multilayered fibrous material 150 after it becomes separated from the unit of continuous multilayered fibrous material 150 , and therefore, this portion of the second mesh belt 102 is also heated to a predetermined temperature before it comes into contact with the unit of continuous multilayered fibrous material 150 again, so that the efficiency with which the unit of continuous multilayered fibrous material 150 is heated in the heating section 120 is prevented from reducing. The temperature of a given portion of the third mesh belt 103 drops as this portion of the third mesh belt 103 comes into contact with the cooling air while it is moving between the second air sending camber 142 and second air receiving chamber 141 , and therefore, it is heated to a predetermined temperature before it comes into contact with the unit of continuous multilayered fibrous material 150 , so that the temperature of the top portion of the compressed unit of continuous multilayered fibrous material 150 is prevented from rapidly dropping. As a result, the entirety of the unit of continuous multilayered fibrous material 150 is evenly compressed across the surfaces to the core while it is kept at the temperature to which it is heated in the heating section 120 , eliminating such a problem that the unit of continuous multilayered fibrous material 150 is compressed after it begins to solidify due to the temperature drop.
[0112] Next, an example of a process, in which a unit of continuous fibrous material with an apparent bulk density of 0.038-0.043 g/cm 3 and a thickness of 35 mm is continuously formed of a supply of the sheathed fibers with a fineness of 2-6 deniers, with the use of the forming apparatus illustrated in FIG. 10, will be described.
[0113] (2-1) Preparatory Process
[0114] First, the unit of continuous multilayered fibrous material 150 similar to the multilayered fibrous material block 50 in the first embodiment is prepared. Then, the position of the second mesh belt 102 is adjusted; the second mesh belt 102 is vertically moved to a position at which the unit of continuous multilayered fibrous material 150 which has been sandwiched by the two ventilatory sheets 111 and 112 and mounted on the first mesh belt 101 does not make contact with the second mesh belt 102 . Since the thickness of a unit of continuous fibrous aggregate into which the unit of continuous multilayered fibrous material 150 is formed is 35 mm, the position of the third mesh belt 103 is adjusted; the third mesh belt 103 is vertically moved so that the thickness of the unit of continuous multilayered fibrous material 150 becomes 35 mm in the cooling section 140 . The rotational velocities of the mesh belts 101 - 103 are set so that the velocity at which the unit of continuous multilayered fibrous material 150 is conveyed becomes 0.5 m/min.
[0115] As for the heating section 120 , a temperature to which air is heated, a velocity at which air is blown, and the like factors, are set in accordance with the physical properties of the fiber. More specifically, the unit of continuous multilayered fibrous material 150 is formed of strands of such sheathed fiber that has a core portion of polyethylene and a sheath portion of polypropylene as described before. Therefore, it is required that the unit of continuous multilayered fibrous material 150 is heated to a temperature, which is higher than the melting point of polyethylene and is lower than the melting point of polypropylene, while the unit of continuous multilayered fibrous material 150 is conveyed to the downstream end of the heating section 120 . In this embodiment, the heated air temperature was set to approximately 140° C., and the heated air velocity was set to a velocity in a range of 0.3-0.8 m/sec.
[0116] As for the cooling section 140 , the temperature and velocity of cooling air, and the like factors, are set based on the fact that polyethylene, that is, one of the constituents of the fiber in the unit of continuous multilayered fibrous material 150 , must be cooled to a temperature lower than the melting point of polyethylene while the unit of continuous multilayered fibrous material 150 having been heated and compressed is conveyed to the downstream end of the compressing section. It is desired that the unit of continuous multilayered fibrous material 150 is uniformly cooled in terms of its thickness direction, toward the top surface (toward third mesh belt 103 ) starting from the bottom surface (first mesh belt 101 side). In this embodiment, therefore, the cooling air temperature was set to approximately normal temperature, and the cooling air velocity was set to a velocity in a range of 0.2-0.3 m/sec.
[0117] After the various sections are adjusted as described above, the unit of continuous multilayered fibrous material 150 is fed into the heating heating chamber 100 , with the unit of continuous multilayered fibrous material 150 sandwiched by the ventilatory sheets 112 and 111 from the top and bottom sides, respectively.
[0118] (2-2) Heating Process
[0119] After being fed into the heating heating chamber 100 , the unit of continuous multilayered fibrous material 150 is first conveyed into the heating section 120 . While the unit of continuous multilayered fibrous material 150 is conveyed through the heating 120 , it is heated by the heated air blown upward from directly below the unit of continuous multilayered fibrous material 150 . As a result, polyethylene which constitutes the sheath portion of the fiber melts, causing the fibers of the unit of continuous multilayered fibrous material 150 to be welded to each other. During this process, the unit of continuous multilayered fibrous material 150 is kept airborne above the first mesh belt 101 by the upward flow of heated air as shown in FIG. 11, the gravity acting on each fiber being cancelled by the flow. Thus, the fibers in the unit of continuous multilayered fibrous material 150 are thermally welded to each other while remaining in the same state as they were prior to the heating. The properties required of ventilatory sheets 111 and 112 are the same as those in the first embodiment, and a pair of weighting blocks 113 required in this embodiment are the same as the weighting blocks 24 required in the first embodiment. Therefore, they will not be described in detail here.
[0120] (2-3) Compressing Process
[0121] After being compressed by the first and third mesh belts 101 and 103 , the unit of continuous multilayered fibrous material 150 is conveyed through the cooling section 140 while remaining compressed by the first and third mesh belts 101 and 103 . In the cooling section 140 , the cooling air is being blown upward from directly below the path of the unit of continuous multilayered fibrous material 150 . Therefore, the unit of continuous multilayered fibrous material 150 is gradually cooled, and the polyethylene portions of the fibers solidify before the multilayered fibrous material block 50 is released from the compressing effect of the belts 101 and 103 .
[0122] After being passed through the cooling section 140 , the unit of continuous multilayered fibrous material 150 is discharged from the heating heating chamber 100 , and the ventilatory sheets 111 and 112 are removed from the unit of continuous multilayered fibrous material 150 . Consequently, a unit of continuous fibrous aggregate is obtained. The thus obtained unit of continuous fibrous aggregate is cut into a plurality of small pieces of fibrous aggregates of different sizes in accordance with usage.
[0123] As described above, according to this embodiment, the unit of continuous multilayered fibrous material 150 is mounted on a conveyer and is fed into the heating heating chamber 101 , which continuously heats the unit of continuous multilayered fibrous material 150 to a predetermined temperature without compressing it, and then, continuously cools the unit of continuous multilayered fibrous material 150 , while keeping it compressed, immediately after the heating. Therefore, a unit of continuous fibrous aggregate, which has a predetermined bulk density and a predetermined thickness, can be continuously formed. The effect of keeping the unit of continuous multilayered fibrous material 150 airborne by blowing heated air upward from directly below the unit of continuous multilayered fibrous material 150 , and the effect of placing a ventilatory sheet in contact with at least the bottom surface of the unit of continuous multilayered fibrous material 150 , are the same as those in the first embodiment.
[0124] In another embodiment of the present invention, a plurality of pairs of the top and bottom dies used in the first embodiment, and a heating heating chamber capable of continuously moving the plurality of the pairs of the top and bottom dies, are used to form a unit of continuous fibrous aggregate. The preparatory process in this embodiment is the same as that in the above described first embodiment, and therefore, will not be described here. Thus, the details of the heating process, compressing process, and cooling process in this embodiment will be described below.
[0125] (Embodiment 3)
[0126] In this embodiment of the present invention, a unit of continuous fibrous aggregate is formed by preparing plural pairs of the top and bottom dies used in the first embodiment of present invention, and a heating heating chamber capable of continuously moving the plural pairs of the top and bottom dies.
[0127] (3-1) Preparatory Process
[0128] The preparatory process in this embodiment is the same as that in the above described first embodiment, and therefore, its details will not be described here, and the details of the heating, compressing, and cooling processes in this embodiment will be described below.
[0129] (3-2) Heating Process
[0130] A multilayered fibrous material block 50 is placed on each of the bottom dies 32 as in the first embodiment. At this stage, the position of the top die 22 is such that a gap is present between the top die 22 and the ventilatory sheet 5 on the top side. The interior of the heating heating chamber has been preheated to a desired temperature by a heater 12 . In this state, the bottom die 21 on which the multilayered fibrous material block 50 is resting, and the top die 22 set on the multilayered fibrous material block 50 , are moved into the heating heating chamber. The heating heating chamber contains a moving means for moving the top and bottom dies 22 and 21 . In the heating heating chamber, the distance between the bottom and top dies 21 and 22 is maintained at a desired distance by this die moving means. The distance between the bottom and top dies can be optionally set. As described before, the plural pairs of top and bottom dies are prepared, and are sequentially moved through the heating heating chamber. The size (length) of the heating heating chamber is determined in accordance with the required heating time and die moving speed. Since the method for heating the multilayered fibrous material block 50 in the heating heating chamber is the same as that in the above described embodiment, its description will not be given here.
[0131] (3-3) Compressing Process
[0132] After the entirety of the multilayered fibrous material block 50 is heated in the above described heating heating chamber, each of the above described top dies 22 is lowered to compress the multilayered fibrous material block 50 to a desired thickness (bulk density). Each bottom dies 21 is provided with a spacer with a desired height, as was the bottom die 21 in the first embodiment, and each top die 22 is lowered until it comes into contact with the spacer. The aforementioned top die 22 moving means can be vertically moved in this compressing zone. Each top die 22 has been heated to virtually the same temperature as that of the multilayered fibrous material block 50 while being moved through the heating heating chamber by the aforementioned die moving means, as in the first embodiment.
[0133] Also in this compressing process, heating air is not stopped as in the first embodiment, and therefore, the multilayered fibrous material block 50 is compressed while the gravity acting upon each fiber is being cancelled by the flow of the heated air. It is obvious that also in this compressing process, it is desired that the top die 22 is lowered from above the multilayered fibrous material block 50 while the multilayered fibrous material block 50 is kept afloat by the upward flow of heated air from directly below the multilayered fibrous material block 50 .
[0134] (3-4) Cooling Process
[0135] After being compressed to a desired thickness, the top and bottom dies 22 and 21 remaining compressing the multilayered fibrous material block 50 are moved out of the heating heating chamber by the above described moving means, and are cooled in entirety while being kept in the same state as the state in which they were moved out of the heating chamber. As for the cooling method, they may be naturally cooled, or may be forcefully cooled with the use of a cooling fan or the like; any cooling means may be employed as the cooling means for this embodiment. After at least the temperature of the surface layer of the multilayered fibrous material block 50 , that is, the surfaces of the multilayered fibrous material block 50 in contact with the top and bottom dies 22 and 21 falls below the melting point of polyethylene, the top die 22 is moved upward, and the multilayered fibrous material 50 is moved out of the bottom die 21 . At this stage, the multilayered fibrous material block 50 is still firmly in contact with the ventilatory sheets 23 and 25 . In reality, however, the multilayered fibrous material block 50 is the same as the same as the multilayered fibrous material block 55 (FIG. 9). According to this embodiment, after the multilayered fibrous material block 50 is taken out, the next multilayered fibrous material block 50 may be set to repeat the heating-compressing-cooling processes, so that it appears as if a large number of fibrous aggregate blocks are continuously produced. The structures in this embodiment other than those described above, and their effects, are the same as those in the above described embodiment. Further, as described above, also in the cases of the structures in this embodiment, a large number of fibrous aggregate blocks can be efficiently produced. The size of the apparatus, and the number of the pair of top and bottom dies, should be determined in accordance with the heating time, compressing time, and cooling time for the multilayered fibrous material block 50 , and the speed at which the multilayered fibrous material block 50 is moved.
[0136] While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
|
A forming method for a fiber aggregate in which fibers are heated to be welded with each other, the method includes a heating step of applying upward heated air to a bottom of a block of the fibers to pass the heated air therethrough and to cause the block of fibers to float, wherein at least parts of fibers are melted while the block of the fibers float; a compression step of compressing substantially in a vertical direction the heated block of fibers into a desired height; and a cooling step of cooling the compressed block of fibers to solidify melted portions of the fibers at portions where the fibers intersect with each other.
| 3
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a non-provisional application based on and claiming priority to provisional application Ser. No. 60/802,636, filed May 22, 2006, having the first named inventor Stefan Andren and attorney docket number 005127.00649.
FIELD OF THE INVENTION
[0002] The present invention relates generally to user interfaces on consumer electronic devices. More specifically, the invention relates to a user interface for remotely controlling a digital media player, such as a media player that plays MP3, ACC, or other audio files. Various examples of the invention are particularly applicable for use with a watch that remotely controls a digital media player.
BACKGROUND OF THE INVENTION
[0003] Digital media players, such as music players that play back sound files stored in an electronic storage medium, are becoming ubiquitous. Because of their portability, many people listen to music or other recordings while performing some type of physical activity, such as jogging or exercising. While the small form factor of digital media players allows them to be easily carried while performing a physical activity, that same small form factor often makes them difficult to control during such physical activity due to the fine motor skills required to control most digital media players. That is, while performing a physical activity such as jogging, it becomes more difficult to use the fine motor skills necessary to control a digital media player.
BRIEF SUMMARY OF THE INVENTION
[0004] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to the more detailed description provided below.
[0005] To overcome limitations in the prior art described above, and to overcome other limitations that will be apparent upon reading and understanding the present specification, aspects of the present invention are directed to a remote control device for controlling a digital media player. Some implementations may be used on a watch or similar alternately-purposed device configured to control a digital music player in addition to performing other functions. A wristwatch or other alternatively-purposed device may incorporate a transceiver for communicating with the digital media player.
[0006] A user may interact with the wristwatch using a plurality of buttons disposed about a housing of the watch, through which the user may adjust a volume level of the digital media player, navigate audio playback, power the digital media player on and off, request playback of a song previously identified by the user, and adjust settings of the wristwatch. The wristwatch and/or the digital media player may be in communication with a biological performance measurement device, and the user, via the wristwatch, may request playback of a biological performance measurement recorded by the biological performance measurement device.
[0007] Methods and systems may encompass a device (e.g., a watch) having a device housing configured to be worn by a human user, a display providing visual output of the device, an input subsystem comprising a plurality of input buttons, a transceiver for communicating with a digital media player based on input received from a user via the plurality of buttons, and a processor for controlling overall operation of the device based on stored control logic. The control logic may indicate that the device, upon detecting a brief press of a first button of the plurality of input buttons, sends a play/pause toggle command to the digital media player. The device, upon detecting a brief press of a second button of the plurality of input buttons, sends a command to the digital media player to skip to a next audio file. The device, upon detecting a long press of the second button, sends a command to the digital media player to fast forward a currently playing audio file. The device, upon detecting a brief press of a third button of the plurality of input buttons, sends a command to the digital media player to skip to a previous audio file. The device, upon detecting a long press of the third button, sends a command to the digital media player to rewind a currently playing audio file. The device, upon detecting a brief press of a fourth button of the plurality of input buttons, sends a command to the digital media player to increment a volume up one step. The device, upon detecting a long press of the fourth button, sends a command to the digital media player to scroll volume up while the fourth button remains in a depressed state.
[0008] The device, upon detecting a brief press of a fifth button of the plurality of input buttons, sends a command to the digital media player to decrement a volume down one step. The device, upon detecting a long press of the fifth button, sends a command to the digital media player to scroll volume down while the fifth button remains in a depressed state.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a watch according to an illustrative embodiment of the invention.
[0010] FIG. 2 illustrates a control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0011] FIG. 3 illustrates a feedback/PowerPlay control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0012] FIG. 4 illustrates a volume control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0013] FIG. 5 illustrates a track change control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0014] FIG. 6 illustrates a track change control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0015] FIG. 7 illustrates a play/pause/power control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0016] FIGS. 8 and 9 illustrates an adjust mode control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0017] FIGS. 10-12 illustrate animations that may be displayed by a watch while controlling a remote digital music player according to an illustrative aspect described herein.
[0018] FIG. 13 illustrates a multi-button control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0019] FIG. 14 illustrates a demo mode animation according to an illustrative aspect described herein.
[0020] FIG. 15 illustrates a wake up animation according to an illustrative aspect described herein.
[0021] FIG. 16 illustrates a watch according to an illustrative embodiment of the invention.
[0022] FIG. 17 illustrates a volume control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0023] FIG. 18 illustrates a track control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0024] FIG. 19 illustrates a track control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0025] FIG. 20 illustrates a feedback/PowerPlay control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0026] FIG. 21 illustrates a play/pause/power control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0027] FIG. 22 illustrates an adjust mode control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0028] FIG. 23 illustrates a sport mode control flow for controlling the operation of a watch and a remote digital music player according to an illustrative aspect described herein.
[0029] FIG. 24 illustrates a block hardware diagram of a watch according to one or more illustrative aspects described herein.
DETAILED DESCRIPTION OF THE INVENTION
[0030] As discussed herein, various examples of the invention may be employed with a watch or other multipurpose device to control the operation of a digital media player. Digital media players include, for example, music players that play back sound files saved in any of a variety of formats, including MP3 files, ACC files, and WAV files. Depending upon the type of digital media player, these files may be stored on a magnetic storage medium, such as a magnetic hard disk drive, in an electronic memory circuit, such as a flash memory device, or in any other known storage media. With some examples of the invention, the sound files may be stored on an optical storage medium, such as a compact disc player. Still further, with some examples of the invention, the digital media player may additionally play back and display a video file, such as an MPEG file, display photos, play games, etc.
[0031] FIG. 1 illustrates a watch that may implement one or more aspects of the invention. As seen in FIG. 1 , the watch may include five buttons on its face: a center button 103 , a left face button 105 , a right face button 107 , an upper face button 109 a lower face button 111 , a left side button 113 , and a right side button 115 . This button arrangement or a portion thereof (e.g., buttons 103 - 111 ) may correspond to a conventional button configuration on a digital media player. Buttons 105 - 111 may be disposed about a bezel of watch 101 . In this configuration, the center face button 103 may correspond to a “PLAY” command, the left face button 105 may correspond to a “REWIND/PREVIOUS TRACK” command, the right face button 107 may correspond to a “FORWIND/NEXT TRACK” command, the upper face button 109 may correspond to a “VOLUME UP” command, and the lower face button 111 may correspond to a “VOLUME DOWN” command. In the illustrated example, watch 101 also has a pair of buttons on either side of its casing, referred to herein as left side button 113 and right side button 115 , respectively. Watch 101 may also include a display area 117 , e.g., an LCD display, dot matrix LEDs, or the like.
[0032] Watch 101 may wirelessly communicate with digital media player 121 based on button commands input by a user or wearer of watch 101 . For example, when a user presses an initial button (e.g., any button), watch 101 may wirelessly “pair up” with digital media player 121 .
[0033] With reference to FIG. 2 , depressing each button of watch 101 activates a function on either the watch, digital media player 121 communicating with the watch from a remote location, or both. As used in the figures, the abbreviation “P” indicates the action of briefly depressing a corresponding button, also referred to herein as a brief press. The abbreviation “LP” indicates the action of depressing the corresponding button and then holding that corresponding button in the depressed position for some threshold period of time, e.g., greater than 0.5 seconds, also referred to herein as a long press. Thus, in the illustrated example of FIG. 2 , briefly depressing right side button 115 causes the watch to display its current time values, while depressing and holding (long press) right side button 115 causes the watch to initiate its adjust mode, allowing the user to adjust the current time values.
[0034] With reference to FIG. 3 , the left side button 113 may perform functions associated with the remotely controlled digital media player. With various examples of the invention, the digital media player (or the watch) may be in communication with yet another device 119 that measures an activity performance parameter associated with the user. The activity performance parameter measurement device 119 may be a device that measures a biological performance parameter associated with the user, such as the user's heart rate or blood oxygen content. The activity performance measurement device 119 alternately or additionally may be a device that measures a physical performance parameter associated with the user, such as the distance traveled by a user, the user's speed, or a current position of the user. With these examples of the invention, when the user briefly depresses the left side button 113 , the watch 101 may command the digital media player to audibly play back the value of the performance parameter most recently measured by the activity performance measurement device 119 .
[0035] If, however the user depresses and holds left side button 113 , then watch 101 may command the digital media player to enter a PowerPlay mode, where the digital media player plays back a specific sound file previously designated by the user. For example, a user may find a favorite song particularly inspirational when performing some type of physical activity such as running up a hill or lifting heavy weights. If the user feels the need to obtain extra inspirational encouragement, such as just before getting his or her second wind or at the final length of an arduous race, the user can depress and hold left side button 113 to cause the digital media player to begin playback of the previously designated song. Of course, in addition to an inspirational song, a user can designate left side button 113 to playback any desired sound file, such as a sound file containing inspirational words or a song useful to maintain a specific pace.
[0036] With reference to FIG. 4 , top button 109 and bottom button 111 may be used to remotely adjust a volume level up and down, respectively, of the digital media player. When a user briefly presses top button 109 , watch 101 sends a command to the digital media player to increase its volume one incremental step. When a user presses and holds top button 109 , watch 101 sends a command to the digital media player to keep increasing its volume until top button 109 is released. When a user briefly presses bottom button 111 , watch 101 sends a command to the digital media player to decrease its volume one incremental step. When a user presses and holds bottom button 111 , watch 101 sends a command to the digital media player to keep decreasing its volume until bottom button 111 is released. As shown in FIG. 4 , watch 101 may provide visual feedback based on each action.
[0037] With reference to FIG. 5 and FIG. 6 , left button 105 and right button 107 , respectively, may be used to move backward and forward, respectively, audio playing on digital media player 121 . When a user briefly presses left button 105 , watch 101 sends a command to the digital media player to skip to a previous or prior audio file. When a user presses and holds left button 105 , watch 101 sends a command to the digital media player to rewind a currently playing audio file. When a user briefly presses right button 107 , watch 101 sends a command to the digital media player to skip to a next or subsequent audio file. When a user presses and holds right button 107 , watch 101 sends a command to the digital media player to fast forward a currently playing audio file. As shown in FIG. 5 and FIG. 6 , watch 101 may provide visual feedback based on each action.
[0038] With reference to FIG. 7 , center button 103 may be used to control start/stop operations of digital media player 121 . For example, when a user briefly presses center button 103 , watch 101 sends a play/pause toggle command to digital media player 121 to alter between a play and a pause state. When a user presses and holds center button 103 , watch 101 sends a command to the digital media player to either stop/pause a workout (when in a special workout mode) or to power down (when not in the special workout mode). As shown in FIG. 7 , watch 101 may provide visual feedback based on each action.
[0039] FIG. 1 illustrates display 117 in a default state, e.g., displaying no information. Each of FIGS. 2-7 illustrate display 117 providing visual feedback based on the action that watch 101 performs. The visual feedback may include a static display of a symbol, design, pattern, number or letter (collectively, icon), flashing icon, or an animated icon.
[0040] In an embodiment incorporating a speaker, audible feedback may be included as well, for example, to confirm button presses. Each of FIGS. 2-7 further indicates a wait period or other event associated with each action that, upon the occurrence of the event, display 117 returns to a default state.
[0041] FIGS. 2-7 illustrate basic operations of an illustrative embodiment. If any button becomes stuck in a pressed position, watch 101 may send a clear signal after some predetermined period of time, e.g., 2 minutes. Watch 101 may require some predetermined minimum time lapse between button presses. That is, watch 101 may ignore a button press that follows less than the predetermined amount of time after a previous button press. According to an illustrative embodiment, multiple simultaneous button presses may be ignored, or may cause watch 101 to perform an additional function. For example, FIG. 13 illustrates that a demo mode may be entered by pressing a first button combination, e.g., buttons 105 , 107 , for some predetermined amount of time, e.g., >5. A master reset may be performed by pressing a second button combination, e.g., buttons 103 , 109 , for some predetermined amount of time, e.g., >5 secs. Other button combinations and/or predetermined amounts of time may be used.
[0042] FIGS. 8-9 illustrate a control flow for adjusting the time values of watch 101 . While in the time adjust mode, display 117 may remain in an always on state. After some predetermined amount of time of inactivity, e.g., 30 seconds, watch 101 may revert to a default mode (i.e., exit the time adjust mode) and return display 117 to a default state. FIGS. 10 and 11 illustrate animations 1001 , 1003 , 1005 , 1101 , 1103 , 1005 that may be displayed by watch 101 on display 117 during various steps of the control flow illustrated in FIGS. 8-9 . For example, upon entering time adjust mode by pressing and holding right side button 115 for some predetermined amount of time (e.g., >0.5 seconds), FIG. 8 indicates that the “Hours” icon “H” may be displayed in an animated manner according to animation 1001 ( FIG. 10 ) before the user may adjust the hours. The remainder of FIGS. 8-9 also identify which of the animations shown in FIG. 10 and FIG. 11 correspond to each action while watch 101 is in the time adjust mode depicted FIGS. 8-9 . The animations in FIG. 10 and FIG. 11 are similar, except that whereas in FIG. 10 the icons appear from the right, in FIG. 11 the icons appear from the left. In an alternative embodiment, the same animation may be used regardless of whether a left or right button triggered an action.
[0043] FIG. 12 similarly illustrates animations 1201 , 1203 , 1205 , 1207 , 1209 , and 1211 that may be displayed by watch 101 on display 117 during various steps of the control flow illustrated in FIGS. 3-9 . For example, watch 101 may display animation 1201 on display 117 when a user briefly presses button 107 from a default mode to skip to a next track. Watch 101 may display animation 1203 on display 117 when a user briefly presses button 105 from a default mode to skip to a previous track. Watch 101 may display animation 1205 on display 117 when a user briefly presses button 113 from a default mode to request voice feedback to audibly play back a value measured by the activity performance measurement device 1 19 . Watch 101 may display animation 1207 on display 117 when a user simultaneously presses button 113 and button 115 to exit an adjust settings mode. Watch 101 may display animation 1209 on display 117 when a user presses and holds button 113 for a predetermined amount of time, e.g., >0.5 seconds, from a default mode to request the PowerPlay mode described above. Watch 101 may display animation 1211 on display 117 when a user presses and holds button 103 for a predetermined amount of time, e.g., >0.5 seconds, from a default mode to request that digital media player 121 either stop/pause a workout or put the digital media player in a power down mode (depending on the current mode of the digital media player, as discussed above).
[0044] FIG. 14 illustrates a demo mode animation 1401 that may be displayed by watch 101 on display 117 as a result of a user pressing a button combination to enter a demo mode, e.g., as illustrated in FIG. 13 . FIG. 15 illustrates a wake up animation sequence that watch 101 may display on display 117 when either watch 101 and/or digital media player 121 wakens from a power down mode.
[0045] FIG. 16 illustrates a watch 1601 according to a second illustrative embodiment of the invention. Watch 1601 may include input buttons 1603 , 1605 , 1607 , 1609 , 1611 , 1613 , 1615 , and 1617 , and visual display 1619 . Watch 1601 may wirelessly communicate with digital media player 121 . Digital media player 121 and/or watch 1601 may be in further communication with performance measuring device 119 . Buttons may be placed around a bezel of watch 1601 , on one or more sides of watch 1601 , on the face of watch 1601 , or elsewhere as desired.
[0046] One or more buttons 1603 - 1617 may cause watch 1601 to send one or more commands to digital media player 121 . In the presently illustrated embodiment, button 1617 may correspond to a “PLAY” command, button 1607 may correspond to a “REWIND/PREVIOUS TRACK” command, the button 1609 may correspond to a “FORWIND/NEXT TRACK” command, button 1603 may correspond to a “VOLUME UP” command, and button 1605 may correspond to a “VOLUME DOWN” command. Watch 101 may wirelessly communicate with digital media player 121 based on button commands input by a user or wearer of watch 101 . For example, when a user presses an initial button (e.g., any button), watch 101 may wirelessly “pair up” with digital media player 121 .
[0047] FIG. 17 illustrates a control flow for adjusting a volume level of digital media player 121 using watch 1601 . Top button 1603 and bottom button 1605 may be used to remotely adjust a volume level up and down, respectively, of digital media player 121 . When a user briefly presses top button 1603 , watch 1601 sends a command to the digital media player to increase its volume one incremental step. When a user presses and holds top button 1603 , watch 1601 sends a command to the digital media player to keep increasing its volume until top button 1603 is released. When a user briefly presses bottom button 1605 , watch 1601 sends a command to the digital media player to decrease its volume one incremental step. When a user presses and holds bottom button 1605 , watch 1601 sends a command to the digital media player to keep decreasing its volume until bottom button 1605 is released. As shown in FIG. 17 , watch 1601 may provide visual feedback based on each action.
[0048] With reference to FIGS. 18 and 19 , right button 1609 and left button 1607 , respectively, may be used to move forward and backward, respectively, audio playing on digital media player 121 . When a user briefly presses left button 1607 , watch 1601 sends a command to the digital media player to skip to a previous or prior audio file. When a user presses and holds left button 1607 , watch 1601 sends a command to the digital media player to rewind a currently playing audio file. When a user briefly presses right button 1609 , watch 1601 sends a command to the digital media player to skip to a next or subsequent audio file. When a user presses and holds right button 1609 , watch 1601 sends a command to the digital media player to fast forward a currently playing audio file. As shown in FIG. 18 and FIG. 19 , watch 1601 may provide visual feedback based on each action.
[0049] With reference to FIG. 20 , when the user briefly depresses the northwest button 1611 , watch 1601 may command the digital media player to audibly play back the value of a performance parameter most recently measured by activity performance measurement device 119 . When the user depresses and holds northwest button 1611 , then watch 1601 may command the digital media player to enter the PowerPlay mode described above. As indicated in FIG. 20 , watch 1601 may provide visual feedback based on the action performed.
[0050] With reference to FIG. 21 , southwest button 1617 may be used to control start/stop operations of digital media player 121 . For example, when a user briefly presses southwest button 1617 , watch 1601 sends a play/pause toggle command to digital media player 121 to alter between a play and a pause state. When a user presses and holds southwest button 1617 , watch 1601 sends a command to the digital media player to either stop/pause a workout (when in a special workout mode) or to power down (when not in the special workout mode). As shown in FIG. 21 , watch 1601 may provide visual feedback based on each action.
[0051] Again referring to FIG. 18 , when a user presses northeast button 1613 , watch 1601 may enter a sport mode, further discussed below with reference to FIG. 23 . When a user briefly presses southeast button 1615 , watch 1601 may illuminate a built in light for some predetermined period of time. When a user long presses, watch 1601 may enter an adjust mode, described with reference to FIG. 22 .
[0052] FIG. 22 illustrates control flow of watch 1601 during an adjust mode, e.g., through which a user can alter settings of watch 1601 . Initially, a user long presses southeast button 1615 to enter the adjust mode, and watch 1601 may provide visual feedback 2201 that watch 1601 is in adjust mode. Upon entering adjust mode, watch 1601 may present a first variable for adjustment, e.g., hours. While in the adjust mode, pressing button 1603 may step up a variable currently being adjusted, and long pressing button 1603 may scroll up a variable currently being adjusted. Pressing button 1605 may step down a variable currently being adjusted, and long pressing button 1605 may scroll down a variable currently being adjusted. According to one illustrative embodiment, watch 1601 may cycle through the variables: hours, minutes, seconds, month, day, year, 12/24 time format, display settings (Day-01, Mon-01), and power settings (e.g., power save mode after 0, 1, 3, 6, 12, 24 hours). A user can advance to a next variable or go backward to a previous variable using buttons 1607 and 1609 . Pressing button 1609 may advance the variable being adjusted to a subsequent variable, whereas pressing button 1607 may change the variable being adjusted to a previous variable. Upon reaching the end of the variable list, watch 1601 may loop back to the first variable in the list.
[0053] FIG. 23 illustrates control flow of watch 1601 during a sport mode, e.g., that provides a chronograph feature. Initially, from a default mode, a user may long press button 1613 to cause watch 1601 to enter the sport mode. Once in the sport mode, pressing button 1613 may start and stop a chronograph displayed on watch 1601 , and long pressing button 1615 may clear or reset the chronograph. Another button, e.g., button 1611 , may provide a lap feature while watch 1601 is in sport mode.
[0054] The aforementioned embodiments are for illustrative purposes only. Modifications and variations may be made without departing from the scope of invention. For example, button functions may be swapped, removed, added, or otherwise changed. Watch 101 , 1601 may directly communicate with performance measuring device 119 or may communicate with performance measuring device 119 indirectly through digital media player 121 . Watch 101 , 1601 and digital media player 121 preferably communicate wirelessly, e.g., using Bluetooth, RF, etc., however they may alternatively be directly connected via a cable. Some implementations may be used on a watch or similar alternately-purposed device configured to control a digital media player in addition to performing other functions.
[0055] FIG. 24 illustrates a block hardware diagram of a device 2401 that may be used according to one or more aspects illustrated herein. Device 2401 may represent watch 101 , watch 1601 , or some other alternately-purposed device that is adapted to operate in conformance with one or more aspects described herein. Device 2401 may include a processor 2403 controlling overall operation of the device based on instructions stored in a primary subsystem 2417 and DM control subsystem 2415 . Primary subsystem 2417 stores control logic to cause device 2401 to operate in conformance with a primary function, such as a watch function as is illustrated above, or may include functions for any other alternate-purpose device, e.g., scuba diving, mobile telephony, mobile communications, etc. Alternatively, device 2401 may be a special-purpose device that only controls a digital media player as described herein. Digital media control subsystem 2415 stores control logic to cause device 2401 to operate in conformance with one or more aspects described herein. Subsystems 2415 and 2417 may include volatile and/or nonvolatile memory, as needed.
[0056] Device 2401 may further include input system 2405 , display 2407 , speaker 2409 , I/O data port 2411 , and transceiver 2413 . Input system 2405 may include multiple input buttons such as buttons 103 - 115 and/or button 1603 - 1617 . Input buttons may include physical buttons, soft buttons, switches, levers, toggles, or any other actuatable device or system. Input system, 2405 may further include a microphone for voice recognition. Display 2407 may include an LCD display such as is illustrated in FIGS. 16-23 , and/or a dot matrix LED display such as is illustrated in FIGS. 1-15 . Any other type of known display may alternatively be used. Speaker 2409 may provide audio feedback based on actions/functions of device 2401 , e.g., button confirmation clicks, alarms based on the biological performance parameter meeting predefined criteria (alarms may alternately be implemented in the digital media player to play the alarm through a headset worn by the user). Device 2401 may use a communication port to communicate with digital media player 121 (not shown). For example, I/O 2411 may be used to provide a direct cable connection between device 2401 and digital media player 121 (not shown). Alternatively (or in addition) device 2401 may primarily communicate with digital media player 121 (not shown) via transceiver 2413 , such as a Bluetooth transceiver, RF transceiver, home band radio transceiver, or the like.
[0057] Control logic may be embodied in computer-usable data and/or computer-executable instructions, such as in one or more program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types when executed by a processor in a computer or other device. The computer executable instructions may be stored on a computer readable medium such as a hard disk, optical disk, removable storage media, solid state memory, RAM, etc. As will be appreciated by one of skill in the art, the functionality of the program modules may be combined or distributed as desired in various embodiments. In addition, the control logic may be embodied in whole or in part in firmware or hardware equivalents such as integrated circuits, field programmable gate arrays (FPGA), and the like. Particular data structures may be used to more effectively implement one or more aspects of the invention, and such data structures are contemplated within the scope of computer executable instructions and computer-usable data described herein.
[0058] While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention as set forth herein.
|
Methods and systems for remotely controlling operation of a digital media player are described herein. A wristwatch or other alternatively-purposed device may incorporate a transceiver for communicating with a digital media player. A user may interact with the wristwatch using a plurality of buttons disposed about a housing of the watch, through which the user may adjust a volume level of the digital media player, navigate audio playback, power the digital media player on and off, request playback of a song previously identified by the user, and adjust settings of the wristwatch. The wristwatch and/or the digital media player may be in communication with a biological performance measurement device, and the user, via the wristwatch, may request playback of a biological performance measurement recorded by the biological performance measurement device.
| 6
|
BACKGROUND
[0001] Interactive events and gatherings allow people and/or audience to interact with each other and with event performers. Each interactive experience can be unique and fun. However, interactive events have been constrained to one physical location.
[0002] While live events or gatherings can be broadcasted through Internet or TV channels, interaction options are limited. Each participant of a live event can watch the same live video stream. Participants do not feel connected with other participants in remote physical venues nor the performer(s) or speaker(s) of the live event or gathering.
DISCLOSURE OF INVENTION
[0003] A method of operating a network-capable experience platform system is disclosed. The method includes: facilitating an interactive gathering by providing layers for composing a live experience presentation on a participant device, the layers including a content layer; identifying a relationship between the participant device and a vehicle; configuring the live experience presentation based on the relationship between the participant device and the vehicle; generating an interactive object within the layers based on the relationship; and managing the interactive object based on the relationship. The method may be implemented as one or more modules stored on a non-transitory storage medium executable by a processor.
[0004] A method of operating a network-capable participant device is also disclosed. The method includes: receiving a content layer at the participant device; generating a live experience presentation for an interactive gathering on the participant device, the live experience presentation composed of layers including a base layer and the content layer; identifying a relationship between the participant device and a vehicle; configuring the live experience presentation based on the relationship; generating an interactive object within the layers based on the relationship; and managing the interactive object based on the relationship.
[0005] An in-vehicle device coupled to a vehicle is further disclosed. The in-vehicle device is configured to join or create an interactive gathering and interact with a participant device through a together experience service. The in-vehicle device includes: a network device configured to communicate with the together experience service and receive multimedia stream layers from the together experience service; a sensor configured to provide a location information of the vehicle; a input device configured to capture a multimedia stream; and a module stored on a non-transitory storage medium, when executed by a processor is configured to: receive a video stream from the participant device external to the vehicle via the network device; generate a live experience presentation of the interactive gathering, the live experience presentation composed of the multimedia stream layers including a content layer and the video stream; provide an interactive object on the live experience presentation capable of affecting external live experience presentation of the participant device to facilitate interaction among participants of the interactive gathering.
BRIEF DESCRIPTION OF DRAWINGS
[0006] These and other objects, features, and characteristics of the present disclosure will become more apparent to those skilled in the art from a study of the following detailed description in conjunction with the appended claims and drawings, all of which form a part of this specification. In the drawings:
[0007] FIG. 1 illustrates an interactive experience system in accordance with one embodiment of the present disclosure.
[0008] FIG. 2 illustrates a schematic block diagram of a cloud-based experience platform 160 according to another embodiment of the present disclosure.
[0009] FIG. 3 illustrates a flow chart showing a set of operations 300 that may be used in accordance with yet another embodiment of the present disclosure.
[0010] FIG. 4 illustrates a flow chart showing a set of operations that may be used in accordance with yet another embodiment of the present disclosure.
[0011] FIG. 5 illustrates a an interior view of an automobile implementing an interactive experience system in accordance with yet another embodiment of the present disclosure.
[0012] FIG. 6 illustrates devices in an automobile implementing an interactive experience system in accordance with yet another embodiment of the present disclosure.
[0013] FIG. 7 illustrates devices in an automobile implementing an interactive experience system in accordance with yet another embodiment of the present disclosure.
[0014] FIG. 8 illustrates an exterior view of an automobile implementing an interactive experience system in accordance with yet another embodiment of the present disclosure.
[0015] FIG. 9 illustrates devices in an airport waiting area implementing an interactive experience system in accordance with yet another embodiment of the present disclosure.
[0016] FIG. 10 illustrates devices on an aircraft implementing an interactive experience system in accordance with yet another embodiment of the present disclosure.
[0017] FIG. 11 illustrates devices on an aircraft implementing an interactive experience system in accordance with yet another embodiment of the present disclosure.
[0018] FIG. 12 illustrates architecture of video audio host system at a host venue of an interactive experience in accordance with yet another embodiment of the present disclosure.
[0019] The drawings have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be expanded or reduced to help improve the understanding of the embodiments of the present disclosure. Similarly, some components and/or operations may be separated into different blocks or combined into a single block for the purposes of discussion of some of the embodiments of the present disclosure. Moreover, while the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0020] Various embodiments of the present disclosure generally relate to methods and systems for providing an interactive experience capable of synchronizing participants at one or more physical venues. In some embodiments, the one or more physical venues may include mobile vehicles, stationary locations, or any combination thereof. Vehicles may include, but are not limited to, aircraft, trains, boats, buses, automobiles, emergency vehicles, or any combination thereof. In such vehicles, participants may include, but are not limited to, drivers, pilots, support staff such as an airline flight crew, passengers, or any combination thereof. Stationary locations may include, but are not limited to, buildings, stadiums, houses, parks, plazas, other locations that are not mobile, or any combination thereof.
[0021] Traditionally, participants in vehicles had limited options to interact with other participants in their vehicle, with participants in other vehicles, or with participants at other remote stationary physical venues. For example, some airlines provide passengers with an option to chat via an instant message service with fellow passengers on a flight. In such an example, passengers may communicate but do not feel connected. Although in close proximity to each other, passengers may feel disconnected from each other due to the way in which they are seated. In contrast, various embodiments of the present disclosure provide multiple participants an interactive experience through the use of multiple devices, multiple sensors and/or an experience platform. The interactive experience may be presented to participants in the form of audio, visual, tactile, or other sensations. Streams of data from one or more physical venues or at other physical venues may be coupled and synchronized through an experience platform. The content (e.g. audio and/or visual streams) of the interactive experience may then be shared among participants at any number of physical venues. Any particular participant at a particular physical venue can play an active role in the interactive experience by interacting with other participants at the particular physical venue or with other participants at other physical venues.
[0022] While examples described herein refer to an interactive experience system, the descriptions should not be taken as limiting the scope of the present disclosure. Various alternative, modifications and equivalents will be apparent to those skilled in the art without varying from the spirit of the invention. For example, coupling and synchronizing an interactive event experience may be implemented in any computing system organizing live data stream. For another example, the interactive event experience system may include multiple computer systems spanning multiple locations, or reside in a cloud computing platform. It will be appreciated by one of ordinary skill in the art that computing devices constituting the cloud computing platform need not be located remotely from a particular physical venue. For example, multiple participant devices, such as iPad® devices, iPhone® devices, Android® devices, other tablet devices, or any combination thereof may be located at or near a particular physical venue and may be coupled to each other through a wired (e.g. USB, or Ethernet over twisted pairs of copper cable such as Category 6 cable) or wireless (e.g. Wifi, or Bluetooth) connection, thereby constituting a cloud computing platform.
[0023] FIG. 1 diagrams an interactive experience system 100 suitable for providing an interactive event experience. The system may include an experience platform 160 , a local physical venue 110 and one or more remote physical venues 150 . Examples of the local physical venue 110 or remote physical venues 150 may in include, vehicles, stationary locations, or any combination thereof. The local physical venue 110 may include one or more participant devices 112 , such as iPad® devices, iPhone® devices, Android® devices, other tablet devices, or any combination thereof, one or more integrated venue devices 113 , such as speakers, LCD monitors, sensors (e.g. cameras, microphones, heat sensors, proximity sensors), or any combination thereof, an optional computing service 111 , and an internet connection coupling the one or more participant devices to a cloud computing service 130 . It is appreciated that the experience platform 160 need not be physically separate from the participant devices 112 , 153 , integrated venue devices 113 , 153 , optional computing service 111 , 151 , or cloud computing platform 130 as shown diagrammatically in FIG. 1 . See FIG. 2 for further information on the experience platform 160 . Each of the one or more remote venues 150 may include one or more participant devices 152 , one or more integrated venue devices 153 , an optional computing service 151 , and an internet connection coupling at least one participant device to the cloud computing platform 130 . The experience platform 160 can couple audiovisual streams from the host physical venue 110 and the one or more remote physical venues 150 , and provide a synchronized interactive event experience to all participants.
[0024] The interactive experience system 100 can provide options to a host participant to create an interactive experience spanning across a plurality of physical venues. The host participant may define the interactive experience as a public experience or a private experience. The host participant at the host physical venue may invite participants at the host physical venue, participants at remote physical venues, and/or participants online, to join the interactive experience. If the interactive experience is private, only the host participant and/or invited participants can invite additional participants to join the interactive experience.
[0025] In some embodiments, the interactive experience may include at least a content layer with audio and visual dimensions. The content layer may include live audiovisual streams (e.g. video, still images, and/or rendered graphics) from a plurality of physical venues, recorded audiovisual streams (e.g. video, still images, and/or rendered graphics), streams of data associated with interactive games, streams of data associated with text, streams of data associated with other media (e.g. software, or documents), or any combination thereof. Based on the characteristics of a particular physical venue, the content layer of the interactive experience may be presented differently on different integrated venue devices and participant devices.
[0026] Some embodiments may present a plurality of objects (e.g. graphical tiles displaying video streams presented on an LCD screen, graphical tiles displaying digital still images presented on an LCD screen, graphical tiles displaying graphics associated with an interactive game presented on an LCD screen, audio streams presented through a speaker, or any combination thereof) on an integrated venue device and/or participant device at a physical venue. Each object may correspond to live audiovisual streams from a particular physical venue or from remote physical venues. In some implementations, the volume of the audio stream from a particular participant device and/or a particular integrated venue device may be a function of the proximity between the particular participant device and/or the particular integrated venue device and another participant device and/or another integrated venue device. In some implementations, the audio stream from a particular participant device and/or particular integrated venue device may be set at a constant ambient level or muted if the distances (as displayed on a participant device and/or integrated venue device) between the objects corresponding to the audio stream from the particular participant device and/or the particular integrated venue device are beyond a certain distance from the objects corresponding to another participant device and/or integrated venue device.
[0027] The interactive experience system 100 can provide options to a particular participant at a particular physical venue to select and engage in dialogue with another participant at either the particular physical venue or at a particular remote physical venue. During the dialogue, the objects corresponding to video and audio streams from the particular participant and/or the particular remote physical venue may become larger, as in the size of a particular object, and/or more prominent audio in the interactive event. In some embodiments, close-up video of the particular participant and/or the other participant may be provided while the particular participant and/or the other participant are talking.
[0028] In some embodiments, when the particular participant and/or the other participant start to talk, the volume of audio streams from other dimensions may go down. When the particular participant and/or the other participant stop talking, the volume of audio streams from other dimensions may go up again. In some implementations, video(s) that is shared among all participants in the content layer may be replaced with video and audio streams from the particular participant and/or the other participant who are talking.
[0029] In some embodiments, participants may have different predetermined roles within the interactive experience. The content presented and/or options available to each participant may depend on the pre-determined role of the participant.
[0030] For example, in the case of an interactive experience on an aircraft, the participants may assume a number of different roles including, but not limited to, pilot, passenger, or aircraft support staff. Due to safety concerns, a pilot may not have access to entertainment content, such as video, that is available to the passengers, but may have broad control over the way in which the content is presented to passengers. For example, the pilot may, through the use of the interactive experience system 100 , present visual or audio content associated with flight announcements on integrated venue devices and/or passenger participant devices, or may draw on a live map displayed on integrated venue device and/or passenger participant devices to relay information about a diverted flight path. In order to provide the pilot greater control over the interactive experience, the interactive experience system 100 may provide the pilot with the option to override all content currently displayed on passenger participant devices. Similarly, the interactive experience system 100 may provide the aircraft support staff with options to override a particular interactive experience among passenger participants make an important announcements to passenger participants regarding the flight. Conversely, passenger participants may have only limited control over content displayed on other participant devices. For example, the interactive experience system 100 may allow a family of passenger participants that are not seated together to share photos among passenger participant devices associated with the family of passenger participants, but may not allow the passenger participants to share photos with the integrated venue devices.
[0031] In some embodiments, the content and/or options presented on a participant device may be determined by the relative position of the device within a physical venue.
[0032] For example, in the case of an automobile as a physical venue, the interactive experience system 100 may restrict certain content associated with the interactive experience from being presented on a participant device located near the driver's seat in order to prevent the distraction of a driver participant. In the same example, the interactive experience system 100 may provide the participant device different options to adjust the content of the interactive experience depending on the location of the participant device in the automobile. For example, options to control the ambient temperature in the automobile may be presented on a participant device located near the front passenger seat, but not on participant devices located near the rear passenger seats. Similarly, in the case of an aircraft as a physical venue, the interactive experience system 100 may restrict certain content associated with the interactive experience from being presented on a participant device located in the cockpit in order to prevent the distraction of a pilot and/or co-pilot. In that same example, access to services associated with the interactive experience may differ depending on the class of seating in which a participant device is located. Participant devices located in a first class seating section may be allowed the option of viewing entertainment content not available to participant devices located in the coach seating area.
[0033] The interactive experience system 100 may equalize participant devices and/or integrated venue devices at a plurality of physical venues through an experience platform 160 . The experience platform 160 can couple and synchronize audiovisual streams from the plurality of physical venues, resulting in a synchronized interactive experience between participants at each physical venue. Audio and/or visual streams from participant devices and/or integrated venue devices at a local physical venue 110 and/or remote physical venue 150 may be transmitted to the experience platform 160 via internet. The experience platform 160 can couple and synchronize the audio and/or visual streams from the local physical venue 110 and/or remote physical venue 150 . Audio and/or visual streams from a particular physical venue can be presented as one or more objects on one or more content layers provided by the experience platform 160 , each of the one or more objects corresponding to audio and/or visual streams from a particular physical venue.
[0034] In some embodiments, the experience platform may take a set of audio streams from a particular physical venue at any particular time. The set of audio streams from the particular physical venue can be generated by a microphone, one of the participant device(s), or combined audio streams from the microphone and the participant device. The combined audio streams can be provided by an audiovisual system coupled to the microphone and the smart device at the particular physical venue via a Wi-Fi or a wired connection.
[0035] In some embodiments, options are provided to a particular participant and/or particular physical venue to manage attention in the interactive experience. The particular participant may draw and/or write on the content layer with a variety of color selections. The color ink of drawing or writing can be color-coded with each color representing a specific meaning. For example, an aircraft flight crew participant can display an image of the aircraft on passenger participant devices and then circle the exits of the aircraft in green to indicate points of egress. Similarly, the aircraft flight crew participant may circle a section of the aircraft in red to indicate an area of the aircraft that is not accessible to passengers.
[0036] In some embodiments, participants can be organized into groups. For example, passenger participants on an aircraft may be divided into two teams to play an interactive game through the interactive experience system 100 . Similarly, passenger participants on a flight may compete as a team in an interactive game against passengers on another flight through the interactive experience system 100 .
[0037] In some implementations, a particular participant using a particular participant device may initiate an interaction with other participants by throwing animated objects, such as flowers, eggs, tomatoes, or other animated objects at the screens of other participant devices. In this example, the participant throwing the animated objects may do so by making a hand gesture that is sensed by the particular participant device. In some implementations, a particular participant at a physical venue can participate in the interactive experience through gestures and/or actions, e.g., clapping, cheering, jeering, and booing. In this example, the gestures and/or actions may be sensed by sensors inside participant devices and/or integrated venue devices.
[0038] Some embodiments may provide methods instantiated on an experience platform, a local computer and/or a portable device. In some implementations, methods may be distributed across local and remote devices in the cloud computing service.
[0039] FIG. 2 illustrates a schematic block diagram of a cloud-based experience platform 160 according to another embodiment of the present disclosure. The experience platform 160 may include at least one processor 220 , one or more network interface 250 and one or more computer readable medium 230 , all interconnected via one or more data bus 210 . In FIG. 2 , various components are omitted for illustrative simplicity. The experience platform 160 is intended to illustrate a device on which any other components described in this specification (e.g., any of the components depicted in FIGS. 1-12 ) can be implemented.
[0040] The experience platform 160 may take a variety of physical forms. By way of examples, the experience platform 160 may be a desktop computer, a laptop computer, a personal digital assistant (PDA), a portable computer, a tablet PC, a wearable computer, an interactive kiosk, a mobile phone, a server, a mainframe computer, a mesh-connected computer, a single-board computer (SBC) (e.g., a BeagleBoard, a PC-on-a-stick, a Cubieboard, a CuBox, a Gooseberry, a Hawkboard, a Mbed, a OmapZoom, a Origenboard, a Pandaboard, a Pandora, a Rascal, a Raspberry Pi, a SheevaPlug, a Trim-Slice), an embedded computer system, or a combination of two or more of these. Where appropriate, the experience platform 160 may include one or more experience platform 160 , be unitary or distributed, span multiple locations, span multiple machines, or reside in a cloud, which may include one or more cloud components in one or more networks. Where appropriate, one or more experience platform 160 may perform without substantial spatial or temporal limitation one or more steps of one or more methods described or illustrated herein. As an example and not by way of limitation, one or more experience platform 160 may perform in real time or in batch mode one or more steps of one or more methods described or illustrated herein. One or more experience platform 160 may perform at different times or at different locations one or more steps of one or more methods described or illustrated herein, where appropriate.
[0041] The experience platform 160 preferably may include an operating system such as, but not limited to, Windows®, Linux® or UNIX®. The operating system may include a file management system, which organizes and keeps track of files. In some embodiments, a separate file management system may be provided. The separate file management can interact smoothly with the operating system and provide enhanced and/or more features, such as improved backup procedures and/or stricter file protection.
[0042] The at least one processor 220 may be any suitable processor. The type of the at least one processor 220 may comprise one or more from a group comprising a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU), a physics processing unit (PPU), a digital signal processor, a network processor, a front end processor, a data processor, a word processor and an audio processor.
[0043] The one or more data bus 210 is configured to couple components of the experience platform 160 to each other. As an example and not by way of limitation, the one or more data bus 210 may include a graphics bus (e.g., an Accelerated Graphics Port (AGP)), an Enhanced Industry Standard Architecture (EISA) bus, a front-side bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infiniband interconnect, a low-pin-count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a serial advanced technology attachment (SATA) bus, a Video Electronics Standards Association local (VLB) bus, or another suitable bus or a combination of two or more of these. Although the present disclosure describes and illustrates a particular bus, this disclosure contemplates any suitable bus or interconnects.
[0044] The one or more network interface 250 may include one or more of a modem or network interface. It will be appreciated that a modem or network interface can be considered to be part of the experience platform 160 . The interface can include an analog modem, an asymmetric digital subscribe line (ADSL) modem, a cable modem, a doubleway satellite modem, a power line modem, a token ring interface, a Cambridge ring interface, a satellite transmission interface or any suitable interface for coupling a computer system to other computer systems. The interface can include one or more input and/or output devices. The I/O devices can include, by way of example but not limitation, a keyboard, a mouse or other pointing device, disk drives, printers, a scanner, a touch screen, a tablet screen, and other input and/or output devices, including a display device. The display device can include, by way of example but not limitation, a cathode ray tube (CRT) display, a liquid crystal display (LCD), a 3-D display, or some other applicable known or convenient display device. For simplicity, it is assumed that controllers of any devices not depicted in the example of FIG. 2 reside in the interface.
[0045] The computer readable medium 230 may include any medium device that is accessible by the processor 220 . As an example and not by way of limitation, the computer readable medium 230 may include volatile memory (e.g., a random access memory (RAM), a dynamic RAM (DRAM), and/or a static RAM (SRAM)) and non-volatile memory (i.e., a flash memory, a read-only memory (ROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), and/or an electrically erasable programmable ROM (EEPROM)). When appropriate, the volatile memory and/or non-volatile memory may be single-ported or multiple-ported memory. This disclosure contemplates any suitable memory. In some embodiments, the computer readable medium 230 may include a semiconductor-based or other integrated circuit (IC) (e.g., a field-programmable gate array (FPGA) or an application-specific IC (ASIC)), a hard disk, an HDD, a hybrid hard drive (HHD), an optical disc (i.e., a CD-ROM, or a digital versatile disk (DVD)), an optical disc drive (ODD), a magneto-optical disc, a magneto-optical drive, a floppy disk, a floppy disk drive (FDD), a magnetic tape, a holographic storage medium, a solid-state drive (SSD), a secure digital (SD) card, a SD drive, or another suitable computer-readable storage medium or a combination of two or more of these, where appropriate. The computer readable medium 230 may be volatile, non-volatile, or a combination of volatile and non-volatile, where appropriate.
[0046] Programs 2310 may be stored on the one or more computer readable medium 230 . As an example, but not by way of limitation, the experience platform 160 may load the programs 2310 to an appropriate location on the one or more compute readable medium 230 for execution. The programs 2310 , when executed, may cause the experience platform 160 to perform one or more operations or one or more methods described or illustrated herein. In some implementations, the operations may include, but are not limited to, receiving live stream signals, including audio streams, from each of a plurality of physical venues of an interactive event, synchronizing the live stream signals from the plurality of physical venues, displaying a plurality of objects on a content layer that is instantiated on the display device of each of the plurality of physical venues, each of the plurality of objects corresponding to live stream signals from a specific physical venue, and providing options for a specific participant at a particular physical venue to manage the size of each of plurality of objects on the display device at the particular physical venue.
[0047] As will be appreciated by one of ordinary skill in the art, the operations may be instantiated locally (i.e. on a local computer or a portable device) and may be distributed across a system including a portable device and one or more other computing devices. For example, it may be determined that the available computing power of the portable device is insufficient or that additional computer power is needed, and may offload certain aspects of the operations to the cloud. As discussed earlier, it will be appreciated to one having ordinary skill in the art that the cloud need not be located remotely from a particular physical venue. Instead, the cloud may comprise computing devices, including participant devices, located partially or exclusively at a particular physical venue.
[0048] FIG. 3 illustrates a flow chart showing a set of operations 300 that may be used in accordance with yet another embodiment of the present disclosure. At step 310 , a host participant is provided option to create an interactive experience spanning across one or more physical venues. The interactive experience may have various dimensions, such as a content layer with live audiovisual dimensions and/or a content layer with interactive, graphic, and/or ensemble dimensions. The content layer may include audiovisual streams from a plurality of physical venues associated with the interactive experience and/or audiovisual streams between participants at a particular physical venue associated with the interactive experience.
[0049] At step 320 , one or more options may be provided for a remote participant to join the interactive experience. A participant may opt to join an ongoing interactive experience if the interactive experience is public. If the interactive experience is private, only the host participant and/or existing participants of the interactive experience may invite new participants. At step 330 , an interactive experience may be coupled and synchronized among participants across one or more physical venues.
[0050] FIG. 4 illustrates a flow chart showing a set of operations 400 that may be used in accordance with yet another embodiment of the present disclosure. At step 410 , live streams, including audio and visual streams, may be received from each of one or more physical venues of an interactive experience. The live streams may include close-up video of an individual participant (e.g., a host participant, a particular participant who is talking) and/or a group of participants (e.g., participants at a remote physical venue).
[0051] At step 420 , a plurality of objects may be presented on the corresponding participant devices and/or integrated venue devices of each physical venue. Each of the plurality of objects may correspond to a particular physical venue of the interactive experience. In some implementations, a wide master shot capturing the overall live event at the host venue may be displayed as a content layer on the participant devices and/or integrated venue devices of each physical venue.
[0052] At step 430 , options may be provided to a particular participant at a particular physical venue to manage the position of its corresponding object relative to other objects. The volume of a live audio stream from another physical venue may be a function of distance between the object corresponding to the particular physical venue and the objects corresponding to the other physical venue. The particular participant may move to a different relative position within the particular physical venue to experience different dimensions of the interactive experience.
[0053] At step 440 , options may be provided to the particular participant at the particular physical venue to initiate an interaction with participants located at the particular physical venue or other physical venues of the interactive experience.
[0054] FIGS. 5-8 illustrate, by way of example, an implementation of the methods and systems in accordance with one embodiment of the present disclosure. In this example, a driver 590 has initiated a private interactive experience at an automobile 500 , 800 . FIG. 5 illustrates a driver's view inside an automobile that implements an interactive experience system. FIG. 6 illustrates a remote participant device that is interacting with the automobile illustrated in FIG. 5 . FIG. 7 illustrates a passenger participant using a passenger participant device in the back seat of the automobile illustrated in FIG. 5 . FIG. 8 illustrates an exterior view showing external sensors on the automobile illustrated in FIG. 5 .
[0055] According to FIG. 8 , the automobile 800 may include external sensors 810 such as cameras, heat sensors, proximity sensors, microphones, or any combination thereof. The external sensors may be functionally connected to a computing device located in the automobile via either a wired or wireless connection. The external sensors 810 may also be functionally connected to a participant device located within the automobile or outside of the automobile via a wired or wireless connection. According to FIG. 5 , the automobile 500 may also have internal sensors 510 such as cameras, proximity sensors, or microphones. Also according to FIG. 5 , the automobile may have an integrated display 540 and integrated speakers.
[0056] According to FIG. 5 , an experience platform presents content associated with the interactive experience on one or more objects on one or more content layers. In the illustrated example, objects associated with visual streams may be displayed on the integrated display device inside the automobile. Similarly, objects associated with audio streams may be presented via integrated speakers inside the automobile. In the illustrated example, the objects presented are associated with an audiovisual stream 542 from a remote participant device 630 (as shown in FIG. 6 ), an audiovisual stream 541 from a participant device 730 (as shown in FIG. 7 ) located near the back seat of the automobile 500 , a graphic of a map 543 showing the current location of the automobile 500 , and a object 544 graphically displaying updated data from the external and internal sensors of the automobile 500 .
[0057] According to FIG. 6 , a remote participant 690 may have remote participant device 630 capable of presenting content from the interactive experience. For the purpose of illuminating the present example, the remote participant in this example might be the spouse of the driver 590 who has joined the driver's interactive experience from the couple's home. It should be noted that because the driver 590 initiated a private interactive experience, the remote participant 690 would wait for an invitation from the driver 590 or from an existing participant before joining the interactive experience. The experience platform couples and synchronizes the data associated with the events occurring at the automobile 500 , 800 which allows the remote participant 690 to participate in the interactive experience. In the illustrated example, the objects of the interactive experience presented on the remote participant device 630 are associated with an audiovisual stream 631 from the integrated internal camera 510 inside the automobile 500 focused on the driver 590 , an audiovisual stream 632 from the passenger participant device 730 (as shown in FIG. 7 ) located near the back seat of the automobile 500 , an audiovisual stream 633 from an external camera on the automobile 500 showing the view of the driver 590 , a graphic map 634 showing the current location of the automobile 500 , and an object 635 displaying continuously updated data from the external and internal sensors of the automobile 500 .
[0058] In the illustrated example, the remote participant 690 may interact with the other participants in a number of different ways. For example, the remote participant 690 may make a swiping motion with their finger to draw a circle around a point of interest. The experience platform may then display the circle over the map 543 on the integrated display 540 in the automobile 500 in FIG. 5 . The remote participant 690 may also look up information on a nearby restaurant on the remote participant device 630 and send that information to be displayed on the integrated display 540 at the automobile 500 . Alternatively, the remote participant 690 may send a video clip to the passenger participant device 730 (as shown in FIG. 7 ) located in the back seat of the automobile 500 .
[0059] According to FIG. 7 , a passenger participant 790 may be seated in the back seat of the automobile 500 and have a passenger participant device 730 capable of presenting content from this and/or other interactive experiences. For the purpose of illuminating the present example, the passenger participant 790 in this example might be the child of the driver 590 and the remote participant 690 . Here the passenger participant 790 has joined both the private interactive experience at the automobile and a public interactive experience at a sporting event. The experience platform may present objects associated with both the private interactive experience at the automobile 500 or the public interactive experience at the sporting event. Here, an object of the private interactive experience at the automobile 500 is associated with the audiovisual stream 731 from the remote participant device 630 . The objects of the public interactive experience at the sporting event are associated with an audiovisual stream 732 from the remote physical venue of the sporting event and audiovisual streams 733 from remote participants of the public interactive experience at the sporting event. For the purpose of illuminating the present example, the remote participants 733 of the interactive experience at the sporting event may be friends of the local participant 790 .
[0060] As discussed earlier, a system according to one embodiment of the present disclosure may be configured to limit the display of content on a particular participant device based on the relative location of the participant device in the physical venue. In the present example, according to FIG. 7 , the system may be configured so that the local participant device 730 is incapable of receiving the audiovisual stream 732 from the sporting event when the local participant device 730 is located near the driver's seat of the automobile 500 and the automobile 500 is in motion. Such a configuration would allow the local participant 790 to avoid distraction while driving the automobile 500 . Configuration of this feature may be adjusted according to the characteristics of the physical venue. For example, an interactive experience system in accordance with one embodiment of the present disclosure may recognize that the automobile 500 is equipped with systems allowing the automobile 500 to automatically drive with minimal input from a driver. The interactive experience system can then adjust the configuration thereby allowing a participant device 730 to display the audiovisual stream 732 from the sporting event while the participant device 730 is near the driver's seat and the automobile 500 is in motion.
[0061] FIGS. 9-11 illustrate, by way of example, an implementation of the methods and systems in accordance with one embodiment of the present disclosure. In this example, a participant has initiated a private interactive experience at an aircraft 900 . FIG. 9 illustrates passengers 990 waiting at an airport 910 to board an aircraft 900 and utilizing an interactive experience system such as the interactive experience system illustrated in FIG. 1 . FIG. 10 illustrates a passenger seated in a coach seating section 1000 on board an aircraft 900 utilizing an interactive experience system such as the interactive experience system illustrated in FIG. 1 . FIG. 11 illustrates passengers 1190 seated in a first class lounge 1100 on board an aircraft 900 utilizing an interactive experience system such as the interactive experience system illustrated in FIG. 1 .
[0062] According to FIG. 9 , an airport waiting area 910 may include integrated venue devices, in this example, an integrated display 950 and integrated speakers 940 . Additionally passengers 990 may carry passenger participant devices 930 , in this example, mobile tablet devices. Once a particular participant has initiated the private interactive experience at the aircraft 900 , passengers 990 may join the interactive experience at which point they become passenger participants 990 in the interactive experience. In this example, the interactive experience is private so passengers 990 must wait to be invited before joining the interactive experience. Alternatively, the system may be configured so that passengers 990 automatically join and become participants once they come into close proximity with a physical venue, in this case the aircraft 900 .
[0063] According to FIG. 9 , an experience platform may present content associated with the interactive experience on one or more objects on one or more content layers. In the illustrated example, objects associated with visual streams may be displayed on the integrated display device 950 . Similarly, objects associated with audio streams may be presented via the integrated speakers 940 . Here, the objects of the interactive experience presented on the integrated display 950 and integrated speakers 940 are associated with an audiovisual stream 951 from a flight crew participant, a visual stream of a graphic of a map 952 showing the current location of the aircraft 900 , and a visual stream of a graphic 953 showing updated data from internal and/or external sensors on the aircraft 900 . The objects of the interactive experience presented on the participant devices 930 may be the same as those displayed on the integrated display 950 or they may include objects with particularized information such as ticketing information of seating assignment. Additionally, the interactive experience system may be configured to allow passenger participants 990 to utilize the integrated display 950 and integrated speakers 940 to make announcements. For example, a passenger participant 990 may, with a gesture on a touch-screen passenger participant device 930 , send an object associated with an audiovisual stream from the passenger participant device to the integrated display 950 . The passenger participant 990 may then make an announcement to other participants in the waiting area to ask to switch seats so that they can sit with a family member.
[0064] According to FIG. 10 , the coach seating section 1000 on the aircraft 900 may include a plurality of integrated displays 1040 and integrated speakers. Additionally, the passenger participant may have a passenger participant device 1030 . An experience platform displays content associated with the interactive experience on one or more objects one or more content layers. In the illustrated example, objects associated with visual streams may be displayed on the integrated display device 1040 . Similarly, objects associated with audio streams may be presented via the integrated speakers. Here, the objects of the interactive experience presented on the integrated display devices 1040 and integrated speakers are associated with a live audiovisual stream 1041 from a remote physical venue hosting a sporting event and a live audiovisual stream from a pilot participant 1042 . The objects of the interactive experience presented on the passenger participant device 1030 are associated with live audiovisual streams 1031 from other passenger participants, a live audiovisual stream from the pilot participant 1032 , and a visual stream 1033 of graphics associated with an interactive game of Scrabble.
[0065] In the above example, a live audiovisual stream 1041 from a remote physical venue hosting a sporting event is presented on the integrated displays 1040 and integrated speakers. The selection of content presented on the integrated displays 1040 and speakers may be set by a particular participant, for example a flight crew member. The content presented on the integrated displays 1040 and integrated speakers may also be selected by a direct vote from all of the passenger participants via passenger participant devices 1032 . Additionally, the content presented on integrated displays 1040 and integrated speakers may be selected automatically by the experience platform based on the level of emotional engagement of the passenger participants. In such an embodiment, the level of emotional engagement of the passenger participants may be determined using a plurality of sensors integrated into the physical venue 900 and/or integrated into individual participant devices 1030 .
[0066] In the above example, live audiovisual streams 1031 from other passenger participants are presented on a passenger participant device 1030 . For the purpose of illuminating the present example, the other passenger participants may be members of a family that are seated separately, but wish to speak with one another. The objects associated with the audiovisual streams 1031 from the other passenger participants may be sized according to various criteria. For example, the passenger participant may control the size of each object, by using hand gestures on a touch screen. Additionally, the experience platform may automatically size an object when the passenger participant associate with the object is speaking. Additionally, the experience platform may automatically size objects based on a relative distance between passenger participants associated with the objects on the aircraft 900 .
[0067] In addition to communicating via audiovisual streams, the passenger participants in the above example may interact with each other by playing an interactive game. Here, the passenger participant and three other passenger participants on the aircraft are playing an interactive game of Scrabble 1033 . Additionally, the passenger participant may invite another participant to join the game of scrabble 1033 . The other participant in the game of Scrabble may be physically located on the same flight, on a different flight, or at another remote physical venue, for example a house.
[0068] It should be noted that in the above example, the experience engine is presenting an object associated with an AV stream 1042 from the pilot participant on the passenger participant device 1032 as well as all of the integrated displays 1040 . Here, the pilot participant is overriding all devices associated with the interactive experience (both participant devices and integrated venue devices) to convey an important message to other participants about the flight.
[0069] FIG. 11 illustrates several passenger participants 1190 seated in a first class lounge 1100 in the aircraft 900 . According to FIG. 11 , the coach seating section 1100 on the aircraft 900 may have a one or more integrated displays 1140 and one or more integrated speakers 1140 . Additionally, the passenger participants 1190 may have passenger participant devices 1130 . Similar to the coach seating section 1000 , the experience platform displays content associated with the interactive experience on one or more objects on one or more content layers. In the illustrated example, objects associated with visual streams may be displayed on the integrated display devices 1140 inside the first class lounge 1100 or displayed on participant devices 1130 in the first class lounge 1100 . Similarly, objects associated with audio streams may be presented via integrated speakers 1140 in the first class lounge 1100 or presented via participant devices 1130 in the first class lounge 1100 . As discussed earlier, additional content and/or services may be available to participant devices 1130 located in the first class lounge 1100 that are not available to participant devices 1030 located in the coach seating 1000 . For example, the experience platform may grant priority to participant devices 1130 in the first class lounge 1100 for direct live audiovisual streams to remote participants (e.g. family members and friends on the ground) where granting such services to all participant devices 1030 in the coach seating area 1000 would overwhelm available bandwidth on a satellite connection from the aircraft 900 to the internet.
[0070] It will understood that while the above illustrated examples describe an interactive experience system that manages audiovisual streams the present disclosure is not limited to just audiovisual streams. According to another embodiment, the experience platform may also couple and synchronize streams of data associated with touch, smell or other sensory data that may be used to provide an interactive experience. For example, a particular passenger device may transmit a stream of tactile data. In this example, the particular participant passenger participant may touch a particular passenger particular device and the experience platform may present the tactile data on another passenger participant device in the form of a tactile sensation transmitted to a hand of the other passenger participant, thereby allowing a particular passenger participant to touch another passenger participant seated in another section of the aircraft.
[0071] FIG. 12 illustrates architecture of video and audio system at a host venue 700 of an interactive experience in accordance with yet another embodiment of the present disclosure. It will be appreciated that the host venue in this context may be either a vehicle or a stationary physical venue. In some embodiments, video signals captured at the host venue 700 (e.g., video signals from participant devices) may be transmitted to a house AV system 710 through wired and/or wireless connections. Audio signals captured at the host venue 700 (e.g., audio signals from participant devices) may also be transmitted to the host AV system 710 through wired or wireless connections and combined into one set of audio signals. The house AV system 710 can couple and synchronize received video and audio signals at the host venue 700 . The house AV system 710 may transmit synchronized video and audio signals to an experience platform via internet, a projection video screen, and/or house speakers at the host venue 700 . In some implementations, synchronized video signals may also be transmitted to a DVR for recording.
[0072] In some embodiments, video and audio signals captured at the host venue 700 can be directly transmitted to an experience platform 160 via internet or may be transmitted to experience platform via direct wireless and/or wired transmission between devices (e.g. via Bluetooth). The experience platform 160 can couple and synchronize video and audio signals from a plurality of physical venues of the interactive experience and then transmit synchronize video and audio signals to devices at all physical venues.
[0073] As will be appreciated by one of ordinary skill in the art, the operations or methods may be instantiated locally (i.e., on one local computer system) and may be distributed across remote computer systems. For example, it may be determined that the available computing power of the local computer system is insufficient or that additional computing power is needed, and may offload certain aspects of the operations to the cloud.
[0074] While the computer-readable medium is shown in an embodiment to be a single medium, the term “computer-readable medium” should be taken to include single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that stores the one or more sets of instructions. The term “computer-readable medium” shall also be taken to include any medium that is capable of storing, encoding or carrying a set of instructions for execution by the computer and that cause the computer to perform any one or more of the methodologies of the presently disclosed technique and innovation.
[0075] Further examples of computer-readable medium, machine-readable storage medium, machine-readable medium or computer-readable (storage) medium include but are not limited to recordable type medium such as volatile and non-volatile memory devices, floppy and other removable disks, hard disk drives, optical disks, Digital Versatile Disks, among others and transmission type medium such as digital and analog communication links.
[0076] In some circumstances, operation of a memory device, such as a change in state from a binary one to a binary zero or vice-versa, for example, may comprise a transformation, such as a physical transformation. With particular types of memory devices, such a physical transformation may comprise a physical transformation of an article to a different state or thing. For example, but without limitation, for some types of memory devices, a change in state may involve an accumulation and storage of charge or a release of stored charge. Likewise, in other memory devices, a change of state may comprise a physical change or transformation in magnetic orientation or a physical change or transformation in molecular structure, such as from crystalline to amorphous or vice versa. The foregoing is not intended to be an exhaustive list of all examples in which a change in state for a binary one to a binary zero or vice-versa in a memory device may comprise a transformation, such as a physical transformation. Rather, the foregoing are intended as illustrative examples.
[0077] A storage medium typically may be non-transitory or comprise a non-transitory device. In this context, a non-transitory storage medium may include a device that is tangible, meaning that the device has a concrete physical form, although the device may change its physical state. Thus, for example, non-transitory refers to a device remaining tangible despite this change in state.
[0078] The computer may be, but is not limited to, a server computer, a client computer, a personal computer (PC), a tablet PC, a laptop computer, a set-top box (STB), a personal digital assistant (PDA), a cellular telephone, an iPhone®, an iPad®, a processor, a telephone, a web appliance, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine.
[0079] In alternative embodiments, the machine operates as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine may operate in the capacity of a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment.
[0080] Some portions of the detailed description may be presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers or the like.
[0081] It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or “generating” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
[0082] The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the methods of some embodiments. The required structure for a variety of these systems will appear from the description below. In addition, the techniques are not described with reference to any particular programming language, and various embodiments may thus be implemented using a variety of programming languages.
[0083] In general, the routines executed to implement the embodiments of the disclosure may be implemented as part of an operating system or a specific application, component, program, object, module or sequence of instructions referred to as “programs.” The programs typically comprise one or more instructions set at various times in various memory and storage devices in a computer, and that, when read and executed by one or more processing units or processors in a computer, cause the computer to perform operations to execute elements involving the various aspects of the disclosure.
[0084] Moreover, while embodiments have been described in the context of fully functioning computers and computer systems, various embodiments are capable of being distributed as a program product in a variety of forms, and that the disclosure applies equally regardless of the particular type of computer-readable medium used to actually effect the distribution.
[0085] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but is not limited to.” As used herein, the terms “connected,” “coupled,” or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling of connection between the elements can be physical, logical or a combination thereof. Additionally, the words “herein,” “above,” “below” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or,” in reference to a list of two or more items, covers all the following interpretations of the word, any of the items in the list, all of the items in the list and any combination of the items in the list.
[0086] The above detailed description of embodiments of the disclosure is not intended to be exhaustive or to limit the teachings to the precise form disclosed above. While specific embodiments of and examples for the disclosure are described above for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize. For example, while processes or blocks are presented in a given order, alternative embodiments may perform routines having steps, or employ systems having blocks in a different order, and some processes or blocks may be deleted, moved, added, subdivided, combined and/or modified to provide alternative or sub combinations. Each of these processes or blocks may be implemented in a variety of different ways. Also, while processes or blocks are at times shown as being performed in series, these processes or blocks may instead be performed in parallel or may be performed at different times. Further, any specific numbers noted herein are only examples—alternative implementations may employ differing values or ranges.
[0087] The teaching of the disclosure provided herein can be applied to other systems and not necessarily to the system described above. Any patents and applications and other references noted above, including any that may be listed in accompanying filing papers, are incorporated herein by reference. Aspects of the disclosure can be modified if necessary to employ the systems, functions and concepts of the various references described above to provide yet further embodiments of the disclosure.
[0088] Any patents and applications and other references noted above, including any that may be listed in accompanying filing papers, are incorporated herein by reference. Aspects of the disclosure can be modified if necessary to employ the systems, functions, and concepts of the various references described above to provide yet further embodiments of the disclosure.
[0089] These and other changes can be made to the disclosure in light of the above Detailed Description. While the above description describes certain embodiments of the disclosure and describes the best mode contemplated, no matter how detailed the above appears in text, the teachings can be practiced in many ways. Details of the system may vary considerably in its implementation details while still being encompassed by the subject matter disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the disclosure should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features or aspects of the disclosure with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the disclosure to the specific embodiments disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the disclosure encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the disclosure under the claims.
[0090] While certain aspects of the disclosure are presented below in certain claim forms, the inventors contemplate the various aspects of the disclosure in any number of claim forms. For example, while only one aspect of the disclosure is recited as a means-plus-function claim under 35 U.S.C. §112, ¶ 6 , other aspects may likewise be embodied as a means-plus-function claim, or in other forms, such as being embodied in a computer-readable medium. (Any claims intended to be treated under 35 U.S.C. §112, ¶6 will begin with the words “means for”.) Accordingly, the applicant reserves the right to add additional claims after filing the application to pursue such additional claim forms for other aspects of the disclosure.
[0091] Some portions of this description describe the embodiments of the invention in terms of algorithms and symbolic representations of operations on information. These algorithmic descriptions and representations are commonly used by those skilled in the data processing arts to convey the substance of their work effectively to others skilled in the art. These operations, while described functionally, computationally or logically, are understood to be implemented by computer programs or equivalent electrical circuits, microcode or the like. Furthermore, it has also proven convenient at times to refer to these arrangements of operations as modules, without loss of generality. The described operations and their associated modules may be embodied in software, firmware, hardware or any combinations thereof.
[0092] Any of the steps, operations or processes described herein may be performed or implemented with one or more hardware or software modules, alone or in combination with other devices. In one embodiment, a software module is implemented with a computer program product comprising a computer-readable medium containing computer program code, which can be executed by a computer processor for performing any or all of the steps, operations or processes described.
[0093] Embodiments of the invention may also relate to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, and/or it may comprise a general-purpose computing device selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a nontransitory, tangible computer-readable storage medium, or any type of medium suitable for storing electronic instructions, which may be coupled to a computer system bus. Furthermore, any computing systems referred to in the specification may include a single processor or may be architectures employing multiple processor designs for increased computing capability.
[0094] Embodiments of the invention may also relate to a product that is produced by a computing process described herein. Such a product may comprise information resulting from a computing process, where the information is stored on a nontransitory, tangible computer-readable storage medium and may include any embodiment of a computer program product or other data combination described herein.
|
A system to provide an interactive experience with a participant device operating in relation to a vehicle is disclosed. The interactive experience may include live experience presentations synchronized across multiple participant devices. The multiple participant devices may be operating within or outside of the vehicle. The system may identify a relationship between the participant device and the vehicle. A live experience presentation on the participant device is configured based on the identified relationship. One or more of multimedia and/or multi-sensory streams may be communicated amongst the multiple participant devices and an experience service as layers. The layers are composed to generate the live experience presentation. The experience service may be implemented by an experience platform system.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit under 35 U.S.C §119(e) of U.S. provisional application Nos. 61/290,092 filed Dec. 24, 2009; 61/306,359 filed Feb. 19, 2010; 61/328,316 filed Apr. 27, 2010; 61/349,273 filed May 28, 2010; and 61/356,126 filed Jun. 18, 2010, all of which are herein specifically incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention is related to human antibodies and antigen-binding fragments of human antibodies that specifically bind human angiopoietin-like protein 4 (hANGPTL4), and therapeutic methods of using those antibodies.
STATEMENT OF RELATED ART
Lipoprotein lipase (LPL) has a central role in lipoprotein metabolism to maintain normal lipoprotein levels in blood and, through tissue specific regulation of its activity, to determine when and in what tissues triglycerides (TG) are unloaded. It has been reported that ANGPTL4 inhibits LPL and retards lipoprotein catabolism, in humans and rodents. ANGPTL4 null mice exhibit a significant decrease in serum TG. Conversely, ANGPTL4 injection into mice produces a rapid increase in circulating lipids and this is at a higher rate than the injection of angiopoietin-like protein 3 (ANGPTL3) (Yoshida et al., 2002 , J Lipid Res 43:1770-1772). The N-terminal coiled-coil region, not the C-terminal fibrinogen-like domain, of ANGPTL4 is known to be important in the inhibition of LPL activity and, therefore, for the hypertriglyceridemia indication. These observations indicate that inhibition of ANGPTL4 could be beneficial in treating diseases characterized by elevated lipid levels, including primary dyslipidemia and hypertriglyceridemia associated with obesity, metabolic syndrome, type II diabetes, and the like. ANGPTL4 has also been implicated as having a role in angiogenesis and cancer (Galaup et al., 2006 , PNAS 103(49):18721-18726; Kim et al., 2000 , Biochem J 346:603-610; and Ito et al., 2003 , Cancer Res 63(20):6651-6657).
The nucleic acid and the amino acid sequences of human ANGPTL4 are shown in SEQ ID NOS: 475 and 476, respectively. Antibodies to ANGPTL4 are disclosed in, for example, WO 2006/074228 and WO 2007/109307.
BRIEF SUMMARY OF THE INVENTION
In a first aspect, the invention provides fully human monoclonal antibodies (mAbs) and antigen-binding fragments thereof that specifically bind and neutralize human ANGPTL4 (hANGPTL4) activity.
The antibodies (Abs) can be full-length (for example, an IgG1 or IgG4 antibody) or may comprise only an antigen-binding portion (for example, a Fab, F(ab′) 2 or scFv fragment), and may be modified to affect functionality, e.g., to eliminate residual effector functions (Reddy et al., 2000 , J. Immunol. 164:1925-1933).
In one embodiment, the invention comprises an antibody or antigen-binding fragment of an antibody comprising a heavy chain variable region (HCVR) selected from the group consisting of SEQ ID NO:2, 18, 22, 26, 42, 46, 50, 66, 70, 74, 90, 94, 98, 114, 118, 122, 138, 142, 146, 162, 166, 170, 186, 190, 194, 210, 214, 218, 234, 238, 242, 258, 262, 266, 282, 286, 290, 306, 310, 314, 330, 334, 338, 354, 358, 362, 378, 382, 386, 402, 406, 410, 426, 430, 434, 450, 454, 458, 466, 468 and 487, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity. In another embodiment, the antibody or an antigen-binding fragment thereof comprises a HCVR having an amino acid sequence selected from the group consisting of SEQ ID NO:26, 42, 46, 487, 74, 90, 94, 122, 138, 142, 146, 162 and 166. In yet another embodiment, the antibody or fragment thereof comprises a HCVR comprising SEQ ID NO:42, 487, 90, 138 or 162.
In one embodiment, an antibody or antigen-binding fragment of an antibody comprises a light chain variable region (LCVR) selected from the group consisting of SEQ ID NO:10, 20, 24, 34, 44, 48, 58, 68, 72, 82, 92, 96, 106, 116, 120, 130, 140, 144, 154, 164, 168, 178, 188, 192, 202, 212, 216, 226, 236, 240, 250, 260, 264, 274, 284, 288, 298, 308, 312, 322, 332, 336, 346, 356, 360, 370, 380, 384, 394, 404, 408, 418, 428, 432, 442, 452 and 456, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.
In another embodiment, the antibody or antigen-binding portion of an antibody comprises a LCVR having an amino acid sequence selected from the group consisting of SEQ ID NO: 34, 44, 48, 82, 92, 96, 130, 140, 144, 154, 164 and 168. In yet another embodiment, the antibody or fragment thereof comprises a LCVR comprising SEQ ID NO:44, 92, 140 or 164.
In further embodiments, the antibody or fragment thereof comprises a HCVR and LCVR (HCVR/LCVR) sequence pair selected from the group consisting of SEQ ID NO:2/10, 18/20, 22/24, 26/34, 42/44, 487/44, 46/48, 50/58, 66/68, 70/72, 74/82, 90/92, 94/96, 98/106, 114/116, 118/120, 122/130, 138/140, 142/144, 146/154, 162/164, 166/168, 170/178, 186/188, 190/192, 194/202, 210/212, 214/216, 218/226, 234/236, 238/240, 242/250, 258/260, 262/264, 266/274, 282/284, 286/288, 290/298, 306/308, 310/312, 314/322, 330/332, 334/336, 338/346, 354/356, 358/360, 362/370, 378/380, 382/384, 386/394, 402/404, 406/408, 410/418, 426/428, 430/432, 434/442, 450/452, 454/456, 458/394, 466/404 and 468/408. In one embodiment, the antibody or fragment thereof comprises a HCVR and LCVR selected from the amino acid sequence pairs of SEQ ID NO:26/34, 42/44, 487/44, 46/48, 74/82, 90/92, 94/96, 122/130, 138/140, 142/144, 146/154, 162/164 and 166/168. In another embodiment, the antibody or fragment thereof comprises a HCVR/LCVR pair comprising SEQ ID NO:42/44, 487/44, 90/92, 138/140 or 162/164.
In a second aspect, the invention features an antibody or antigen-binding fragment of an antibody comprising a heavy chain complementarity determining region 3 (HCDR3) amino acid sequence selected from the group consisting of SEQ ID NO:8, 32, 56, 80, 104, 128, 152, 176, 200, 224, 248, 272, 296, 320, 344, 368, 392, 416, 440 and 464, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity; and a light chain CDR3 (LCDR3) amino acid sequence selected from the group consisting of SEQ ID NO:16, 40, 64, 88, 112, 136, 160, 184, 208, 232, 256, 280, 304, 328, 352, 376, 400, 424 and 448, or substantially similar sequences thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity. In one embodiment, the antibody or fragment thereof comprises a HCDR3/LCDR3 amino acid sequence pair comprising SEQ ID NO:32/40, 80/88, 128/136 or 152/160. In another embodiment, the antibody or fragment thereof comprises a HCDR3/LCDR3 amino acid sequence pair comprising SEQ ID NO:32/40 or 80/88.
In a further embodiment, the antibody or fragment thereof further comprises a heavy chain CDR1 (HCDR1) amino acid sequence selected from the group consisting of SEQ ID NO:4, 28, 52, 76, 100, 124, 148, 172, 196, 220, 244, 268, 292, 316, 340, 364, 388, 412, 436 and 460, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity; and a heavy chain CDR2 (HCDR2) amino acid sequence selected from the group consisting of SEQ ID NO:6, 30, 54, 78, 102, 126, 150, 174, 198, 222, 246, 270, 294, 318, 342, 366, 390, 414, 438 and 462, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity; and optionally further comprises a light chain CDR1 (LCDR1) amino acid sequence selected from the group consisting of SEQ ID NO:12, 36, 60, 84, 108, 132, 156, 180, 204, 228, 252, 276, 300, 324, 348, 372, 396, 420 and 444, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity; and/or a light chain CDR2 (LCDR2) amino acid sequence selected from the group consisting of SEQ ID NO:14, 38, 62, 86, 110, 134, 158, 182, 206, 230, 254, 278, 302, 326, 350, 374, 398, 422 and 446, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.
Alternatively, the invention features an antibody or antigen-binding fragment of an antibody comprising a HCDR1/HCDR2/HCDR3 combination selected from the group consisting of SEQ ID NO:4/6/8, 28/30/32, 52/54/56, 76/78/80, 100/102/104, 124/126/128, 148/150/152, 172/174/176, 196/198/200, 220/222/224, 244/246/248, 268/270/272, 292/294/296, 316/318/320, 340/342/344, 364/366/368, 388/390/392, 412/414/416, 436/438/440 and 460/462/464; and/or a LCDR1/LCDR2/LCDR3 combination selected from the group consisting of SEQ ID NO:12/14/16, 36/38/40, 60/62/64, 84/86/88, 108/110/112, 132/134/136, 156/158/160, 180/182/184, 204/206/208, 228/230/232, 252/254/256, 276/278/280, 300/302/304, 324/326/328, 348/350/352, 372/374/376, 396/398/400, 420/422/424 and 444/446/448.
In one embodiment, the HCDR1, HCDR2 and HCDR3 are selected from the group consisting of SEQ ID NO:28/30/32, 76/78/80, 124/126/128, and 148/150/152; and/or the LCDR1, LCDR2 and LCDR3 are selected from the group consisting of SEQ ID NO:36/38/40, 84/86/88, 132/134/136, and 156/158/160. In yet another embodiment, the heavy and light chain CDR amino acid sequences comprise a CDR sequence combination selected from the group consisting of SEQ ID NO:28/30/32/36/38/40, 76/78/80/84/86/88, 124/126/128/132/134/136, and 148/150/152/156/158/160. In yet another embodiment, the antibody or antigen-binding fragment thereof comprises heavy and light chain CDR sequences of SEQ ID NO: 28/30/32/36/38/40, or 76/78/80/84/86/88.
In a related embodiment, the invention comprises an antibody or antigen-binding fragment of an antibody which specifically binds hANGPTL4, wherein the antibody or fragment thereof comprises heavy and light chain CDR domains contained within HCVR/LCVR pairs selected from the group consisting of SEQ ID NO: 2/10, 18/20, 22/24, 26/34, 42/44, 487/44, 46/48, 50/58, 66/68, 70/72, 74/82, 90/92, 94/96, 98/106, 114/116, 118/120, 122/130, 138/140, 142/144, 146/154, 162/164, 166/168, 170/178, 186/188, 190/192, 194/202, 210/212, 214/216, 218/226, 234/236, 238/240, 242/250, 258/260, 262/264, 266/274, 282/284, 286/288, 290/298, 306/308, 310/312, 314/322, 330/332, 334/336, 338/346, 354/356, 358/360, 362/370, 378/380, 382/384, 386/394, 402/404, 406/408, 410/418, 426/428, 430/432, 434/442, 450/452, 454/456, 458/394, 466/404 and 468/408. Methods and techniques for identifying CDRs within HCVR and LCVR amino acid sequences are known in the art and can be applied to identify CDRs within the specified HCVR and/or LCVR amino acid sequences disclosed herein. Conventional definitions that can be applied to identify the boundaries of CDRs include the Kabat definition, the Chothia definition, and the AbM definition. In general terms, the Kabat definition is based on sequence variability, the Chothia definition is based on the location of the structural loop regions, and the AbM definition is a compromise between the Kabat and Chothia approaches. See, e.g., Kabat, “Sequences of Proteins of Immunological Interest,” National Institutes of Health, Bethesda, Md. (1991); Al-Lazikani et al., J. Mol. Biol. 273:927-948 (1997); and Martin et al., Proc. Natl. Acad. Sci. USA 86:9268-9272 (1989). Public databases are also available for identifying CDR sequences within an antibody. In one embodiment, the antibody or fragment thereof comprises CDR sequences contained within a HCVR and LCVR pair selected from the group consisting of the amino acid sequence pairs of SEQ ID NO: 26/34, 42/44, 487/44, 46/48, 74/82, 90/92, 94/96, 122/130, 138/140, 142/144, 146/154, 162/164 and 166/168. In another embodiment, the antibody or fragment thereof comprises CDR sequences contained within the HCVR and LCVR sequence pair of SEQ ID NO: 42/44, 487/44, 90/92, 138/140 or 162/164.
In another related embodiment, the invention provides an antibody or antigen-binding fragment thereof that competes for specific binding to hANGPTL4 with an antibody or antigen-binding fragment comprising heavy and light chain CDR sequences of SEQ ID NO: 28/30/32/36/38/40, 76/78/80/84/86/88, 124/126/128/132/134/136, or 148/150/152/156/158/160. In one embodiment, the antibody or antigen-binding fragment of the invention competes for specific binding to hANGPTL4 with an antibody comprising a HCVR/LCVR sequence pair of SEQ ID NO:42/44, 487/44, 90/92, 138/140, or 162/164.
In another related embodiment, the invention provides an antibody or antigen-binding fragment thereof that binds the same epitope on hANGPTL4 that is recognized by an antibody or fragment thereof comprising heavy and light chain CDR sequences of SEQ ID NO: 28/30/32/36/38/40, 76/78/80/84/86/88, 124/126/128/132/134/136, or 148/150/152/156/158/160. In one embodiment, the antibody or antigen-binding fragment of the invention recognizes the epitope on hANGPTL4 that is recognized by an antibody comprising a HCVR/LCVR sequence pair of SEQ ID NO:42/44, 487/44, 90/92, 138/140, or 162/164.
In a third aspect, the invention provides nucleic acid molecules encoding anti-ANGPTL4 antibodies or fragments thereof, in particular, those described above. Recombinant expression vectors carrying the nucleic acids of the invention, and host cells, e.g., bacterial cells, such as E. coli , or mammalian cells, such as CHO cells, into which such vectors have been introduced, are also encompassed by the invention, as are methods of producing the antibodies by culturing the host cells under conditions permitting production of the antibodies, and recovering the antibodies produced.
In one embodiment, the invention provides an antibody or fragment thereof comprising a HCVR encoded by a nucleic acid sequence selected from the group consisting of SEQ ID NO: 1, 17, 21, 25, 41, 45, 49, 65, 69, 73, 89, 93, 97, 113, 117, 121, 137, 141, 145, 161, 165, 169, 185, 189, 193, 209, 213, 217, 233, 237, 241, 257, 261, 265, 281, 285, 289, 305, 309, 313, 329, 333, 337, 353, 357, 361, 377, 381, 385, 401, 405, 409, 425, 429, 433, 449, 453, 457, 465, 467 and 486, or a substantially identical sequence having at least 90%, at least 95%, at least 98%, or at least 99% homology thereof. In another embodiment, the antibody or fragment thereof comprises a HCVR encoded by a nucleic acid sequence selected from the group consisting of SEQ ID NO: 25, 41, 45, 73, 89, 93, 121, 137, 141, 145, 161, 165 and 486. In yet another embodiment, the antibody or fragment thereof comprises a HCVR encoded by the nucleic acid sequence of SEQ ID NO: 41, 89, 137, 161 or 486.
In one embodiment, an antibody or antigen-binding fragment thereof comprises a LCVR encoded by a nucleic acid sequence selected from the group consisting of SEQ ID NO: 9, 19, 23, 33, 43, 47, 57, 67, 71, 81, 91, 95, 105, 115, 119, 129, 139, 143, 153, 163, 167, 177, 187, 191, 201, 211, 215, 225, 235, 239, 249, 259, 263, 273, 283, 287, 297, 307, 311, 321, 331, 335, 345, 355, 359, 369, 379, 383, 393, 403, 407, 417, 427, 431, 441, 451 and 455, or a substantially identical sequence having at least 90%, at least 95%, at least 98%, or at least 99% homology thereof. In another embodiment, the antibody or fragment thereof comprises a LCVR encoded by a nucleic acid sequence selected from the group consisting of SEQ ID NO: 33, 43, 47, 81, 91, 95, 129, 139, 143, 153, 163 and 167. In yet another embodiment, the antibody or fragment thereof comprises a LCVR encoded by the nucleic acid sequence of SEQ ID NO: 43, 91, 139 or 163.
In further embodiments, the antibody or fragment thereof comprises a HCVR and LCVR (HCVR/LCVR) sequence pair encoded by a nucleic acid sequence pair selected from the group consisting of SEQ ID NO:1/9, 17/19, 21/23, 25/33, 41/43, 486/43, 45/47, 49/57, 65/67, 69/71, 73/81, 89/91, 93/95, 97/105, 113/115, 117/119, 121/129, 137/139, 141/143, 145/153, 161/163, 165/167, 169/177, 185/187, 189/191, 193/201, 209/211, 213/215, 217/225, 233/235, 237/239, 241/249, 257/259, 261/263, 265/273, 281/283, 285/287, 289/297, 305/307, 309/311, 313/321, 329/331, 333/335, 337/345, 353/355, 357/359, 361/369, 377/379, 381/383, 385/393, 401/403, 405/407, 409/417, 425/427, 429/431, 433/441, 449/451, 453/455, 457/393, 465/403 and 467/407. In one embodiment, the antibody or fragment thereof comprises a HCVR/LCVR sequence pair encoded by a nucleic acid sequence pair selected from the group consisting of SEQ ID NO: 25/33, 41/43, 486/43, 45/47, 73/81, 89/91, 93/95, 121/129, 137/139, 141/143, 145/153, 161/163 and 165/167. In yet another embodiment, the antibody or fragment thereof comprises a HCVR/LCVR pair encoded by a nucleic acid sequence pair of SEQ ID NO:41/43, 486/43, 89/91, 137/139 or 161/163.
In one embodiment, the invention features an antibody or antigen-binding fragment of an antibody comprising a HCDR3 domain encoded by a nucleotide sequence selected from the group consisting of SEQ ID NO:7, 31, 55, 79, 103, 127, 151, 175, 199, 223, 247, 271, 295, 319, 343, 367, 391, 415, 439 and 463, or a substantially identical sequence having at least 90%, at least 95%, at least 98%, or at least 99% homology thereof; and a LCDR3 domain encoded by a nucleotide sequence selected from the group consisting of SEQ ID NO: 15, 39, 63, 87, 111, 135, 159, 183, 207, 231, 255, 279, 303, 327, 351, 375, 399, 423 and 447, or a substantially identical sequence having at least 90%, at least 95%, at least 98%, or at least 99% homology thereof. In another embodiment, the antibody or fragment thereof comprises a HCDR3 and LCDR3 sequence pair encoded by the nucleic acid sequence pair of SEQ ID NO: 31/39, 79/87, 127/135 or 151/159. In yet another embodiment, the antibody or fragment thereof comprises a HCDR3 and LCDR3 sequence pair encoded by the nucleic acid sequence pair of SEQ ID NO:31/39 or 79/87.
In a further embodiment, the antibody or fragment thereof further comprises a HCDR1 domain encoded by a nucleotide sequence selected from the group consisting of SEQ ID NO: 3, 27, 51, 75, 99, 123, 147, 171, 195, 219, 243, 267, 291, 315, 339, 363, 387, 411, 435 and 459, or a substantially identical sequence having at least 90%, at least 95%, at least 98%, or at least 99% homology thereof; and a HCDR2 domain encoded by a nucleotide sequence selected from the group consisting of SEQ ID NO:5, 29, 53, 77, 101, 125, 149, 173, 197, 221, 245, 269, 293, 317, 341, 365, 389, 413, 437 and 461, or a substantially identical sequence having at least 90%, at least 95%, at least 98%, or at least 99% homology thereof; and optionally further comprises a LCDR1 domain encoded by a nucleotide sequence selected from the group consisting of SEQ ID NO: 11, 35, 59, 83, 107, 131, 155, 179, 203, 227, 251, 275, 299, 323, 347, 371, 395, 419 and 443, or a substantially identical sequence having at least 90%, at least 95%, at least 98%, or at least 99% homology thereof; and/or a LCDR2 domain encoded by a nucleotide sequence selected from the group consisting of SEQ ID NO: 13, 37, 61, 85, 109, 133, 157, 181, 205, 229, 253, 277, 301, 325, 349, 373, 397, 421 and 445, or a substantially identical sequence having at least 90%, at least 95%, at least 98%, or at least 99% homology thereof.
Alternatively, the invention features an antibody or antigen-binding fragment of an antibody comprising a HCDR1/HCDR2/HCDR3 combination encoded by a nucleotide sequence combination selected from the group consisting of SEQ ID NO:3/5/7, 27/29/31, 51/53/55, 75/77/79, 99/101/103, 123/125/127, 147/149/151, 171/173/175, 195/197/199, 219/221/223, 243/245/247, 267/269/271, 291/293/295, 315/317/319, 339/341/343, 363/365/367, 387/389/391, 411/413/415, 435/437/439 and 459/461/463; and/or a LCDR1/LCDR2/LCDR3 combination encoded by a nucleotide sequence combination selected from the group consisting of SEQ ID NO:11/13/15, 35/37/39, 59/61/63, 83/85/87, 107/109/111, 131/133/135, 155/157/159, 179/181/183, 203/205/207, 227/229/231, 251/253/255, 275/277/279, 299/301/303, 323/325/327, 347/349/351, 371/373/375, 395/397/399, 419/421/423 and 443/445/447.
In one embodiment, the HCDR1, HCDR2 and HCDR3 are encoded by a nucleotide sequence combination selected from the group consisting of SEQ ID NO:27/29/31, 75/77/79, 123/125/127, and 147/149/151; and/or the LCDR1, LCDR2 and LCDR3 are encoded by a nucleotide sequence combination selected from the group consisting of SEQ ID NO:35/37/39, 83/85/87, 131/133/135, and 155/157/159. In yet another embodiment, the antibody or fragment thereof comprises heavy and light chain CDR sequences encoded by a nucleotide sequence combination selected from the group consisting of SEQ ID NO: 27/29/31/35/37/39; 75/77/79/83/85/87; 123/125/127/131/133/135; and 147/149/151/155/157/159. In another embodiment, the antibody or antigen-binding portion thereof comprises heavy and light chain CDR sequences encoded by the nucleotide sequence combination of SEQ ID NO: 27/29/31/35/37/39; or 75/77/79/83/85/87.
In a fourth aspect, the invention features an isolated antibody or antigen-binding fragment of an antibody that specifically binds hANGPTL4, comprising a HCDR3 and a LCDR3, wherein the HCDR3 comprises an amino acid sequence of the formula X 1 -X 2 -X 3 -X 4 -X 5 -X 6 -X 7 -X 8 -X 9 -X 10 -X 11 -X 12 -X 13 -X 14 -X 15 -X 16 -X 17 -X 18 -X 19 -X 20 (SEQ ID NO:471) wherein X 1 is Ala, X 2 is Arg or Lys, X 3 is Gly or Glu, X 4 is Gly, Asp or absent, X 5 is Asp or absent, X 6 is Leu, Arg or absent, X 7 is Arg or Ser, X 8 is Phe, Gly or Arg, X 9 is Leu, His or Asn, X 19 is Asp, Pro or Tyr, X″ is Trp, Tyr or Phe, X 12 is Leu, Phe, Val or Asp, X 13 is Ser, Tyr or Gly, X 14 is Ser, Tyr or Asp, X 15 is Tyr, X 16 is Phe or Gly, X 17 is Leu or absent, X 18 is Asp, X 19 is Tyr, Val or Phe, and X 20 is Trp; and the LCDR3 comprises an amino acid sequence of the formula X 1 -X 2 -X 3 -X 4 -X 5 -X 6 -X 7 -X 8 -X 9 -X 10 (SEQ ID NO:474) wherein X 1 is Gln, X 2 is Asn or Gln, X 3 is Tyr or Leu, X 4 is Asn, His, Ser or Asp, X 5 is Thr or Ser, X 6 is Ala or Tyr, X 7 is Pro, Ser or Phe, X 8 is Leu or Arg, X 9 is Thr, and X 10 is Phe.
In a further embodiment, the antibody or fragment thereof further comprises a HCDR1 sequence comprising an amino acid sequence of the formula X 1 -X 2 -X 3 -X 4 -X 5 -X 6 -X 7 -X 8 (SEQ ID NO:469), wherein X 1 is Gly, X 2 is Gly or Phe, X 3 is Ser or Thr, X 4 is Phe, X 5 is Ser, X 6 is Ile, Ser or Thr, X 7 is His or Tyr, and X 8 is His, Gly or Asp; a HCDR2 sequence comprising an amino acid sequence of the formula X 1 -X 2 -X 3 -X 4 -X 5 -X 6 -X 7 -X 8 (SEQ ID NO:470), wherein X 1 is Ile, X 2 is Asn, Ser or Gly, X 3 is His, Phe, Ser or Val, X 4 is Arg, Asp or Ala, X 5 is Gly, X 6 is Gly or absent, X 7 is Ser, Asn or Asp, and X 8 is Thr or Lys; a LCDR1 sequence comprising an amino acid sequence of the formula X 1 -X 2 -X 3 -X 4 -X 5 -X 6 (SEQ ID NO:472) wherein X 1 is Gln, X 2 is Gly or Ser, X 3 is Ile, X 4 is Ser or Asn, X 5 is Asp, Ser or Arg, and X 6 is Tyr or Trp; and a LCDR2 sequence comprising an amino acid sequence of the formula X 1 -X 2 -X 3 (SEQ ID NO:473) wherein X 1 is Ala or Lys, X 2 is Ala, and X 3 is Ser. The sequence alignments of H1H268P, H1H284P, H1H291P and H1H292P monoclonal antibodies are shown in FIG. 1 (HCVR) and FIG. 2 (LCVR).
In a fifth aspect, the invention features a human anti-ANGPTL4 antibody or antigen-binding fragment thereof comprising a heavy chain variable region (HCVR) encoded by nucleotide sequence segments derived from V H , D H and J H germline sequences, and a light chain variable region (LCVR) encoded by nucleotide sequence segments derived from V K and J K germline sequences, wherein the HCVR and the LCVR are encoded by nucleotide sequence segments derived from a germline gene combination selected from the group consisting of: (i) V H 3-30, D H 5-12, J H 6, V K 1-9 and J K 4; (ii) V H 4-34, D H 3-3, J H 4, V K 1-27 and J K 4; and (iii) V H 3-13, D H 1-26, J H 4, V K 1-5 and J K 1.
In a sixth aspect, the invention features an antibody or antigen-binding fragment thereof that specifically binds to hANGPTL4 with an equilibrium dissociation constant (K D ) of about 1 nM or less, as measured by surface plasmon resonance assay (for example, BIACORE™). In certain embodiments, the antibody of the invention exhibits a K D of about 500 pM or less; about 400 pM or less; about 300 pM or less; about 200 pM or less; about 150 pM or less; about 100 pM or less; or about 50 pM or less.
In a seventh aspect, the present invention provides an anti-hANGPTL4 antibody or antigen-binding fragment thereof that binds hANGPTL4 protein of SEQ ID NO:476, but does not cross-react with a related protein, such as a human angiopoietin-like protein 3 (hANGPTL3; SEQ ID NO:485), as determined by, for example, ELISA, surface plasmon resonance assay, or LUMINEX® XMAP® Technology, as described herein. ANGPTL3 is another secreted protein that is known to reduce LPL activity and has an N-terminal coiled-coil region and a C-terminal fibrinogen-like domain (Ono et al., 2003 , J Biol Chem 43:41804-41809). In related embodiments, the invention provides an anti-hANGPTL4 antibody or antigen binding fragment thereof that binds a hANGPTL4 protein and cross-reacts with a hANGPTL3 protein. In certain embodiments, the binding affinity of the hANGPTL4 antibody or fragment thereof to hANGPTL3 protein is about 75% or less, or about 50% or less, of the binding affinity of the antibody or fragment to the hANGPTL4 protein. In another related embodiment, the invention provides an anti-hANGPTL4 antibody or antigen binding fragment thereof that does not cross-react with mouse ANGPTL4 (mANGPTL4: SEQ ID NO:478) but does cross-react with cynomolgus monkey ( Macaca fascicularis ; the amino acid sequence of the N-terminal 1-148 residues and the encoding DNA sequences are shown as SEQ ID NOS:490 and 489, respectively) and/or rhesus monkey ( Macaca mulatta ; the amino acid sequence of the N-terminal 1-148 residues and the encoding DNA sequences are shown as SEQ ID NOS:492 and 491, respectively) ANGPTL4.
The invention encompasses anti-hANGPTL4 antibodies having a modified glycosylation pattern. In some applications, modification to remove undesirable glycosylation sites may be useful, or e.g., removal of a fucose moiety to increase antibody dependent cellular cytotoxicity (ADCC) function (see Shield et al. (2002) JBC 277:26733). In other applications, removal of N-glycosylation site may reduce undesirable immune reactions against the therapeutic antibodies, or increase affinities of the antibodies. In yet other applications, modification of galactosylation can be made in order to modify complement dependent cytotoxicity (CDC).
In an eighth aspect, the invention features a pharmaceutical composition comprising a recombinant human antibody or fragment thereof which specifically binds hANGPTL4 and a pharmaceutically acceptable carrier. In one embodiment, the invention features a composition which is a combination of an antibody or antigen-binding fragment thereof of the invention, and a second therapeutic agent. The second therapeutic agent may be one or more of any agent such as (1) 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, such as cerivastatin, atorvastatin, simvastatin, pitavastatin, rosuvastatin, fluvastatin, lovastatin, pravastatin, and the like; (2) inhibitors of cholesterol uptake and/or bile acid re-absorption; (3) niacin, which increases lipoprotein catabolism; (4) fibrates or amphipathic carboxylic acids, which reduce low-density lipoprotein (LDL) level, improve high-density lipoprotein (HDL) and TG levels, and reduce the number of non-fatal heart attacks; and (5) activators of the LXR transcription factor that plays a role in cholesterol elimination such as 22-hydroxycholesterol, or fixed combinations such as ezetimibe plus simvastatin; a statin with a bile resin (e.g., cholestyramine, colestipol, colesevelam), a fixed combination of niacin plus a statin (e.g., niacin with lovastatin); or with other lipid lowering agents such as omega-3-fatty acid ethyl esters (for example, omacor). Furthermore, the second therapeutic agent can be one or more other inhibitors of ANGPTL4 as well as inhibitors of other molecules, such as ANGPTL3, ANGPTL5, ANGPTL6 and proprotein convertase subtilisin/kexin type 9 (PCSK9), which are involved in lipid metabolism, in particular, cholesterol and/or triglyceride homeostasis. Inhibitors of these molecules include small molecules and antibodies that specifically bind to these molecules and block their activity.
In related embodiments, the second therapeutic agent may be one or more anti-cancer agents, such as chemotherapeutic agents, anti-angiogenic agents, growth inhibitory agents, cytotoxic agents, apoptotic agents, and other agents well known in the art to treat cancer or other proliferative diseases or disorders, as well as other therapeutic agents, such as analgesics, anti-inflammatory agents, including non-steroidal anti-inflammatory drugs (NSAIDS), such as Cox-2 inhibitors, and the like, so as to ameliorate and/or reduce the symptoms accompanying the underlying cancer/tumor.
In a ninth aspect, the invention features methods for inhibiting hANGPTL4 activity using the anti-hANGPTL4 antibody or antigen-binding portion of the antibody of the invention, wherein the therapeutic methods comprise administering a therapeutically effective amount of a pharmaceutical composition comprising an antibody or antigen-binding fragment of an antibody of the invention and, optionally one or more additional therapeutic agents described above. The disease or disorder treated is any disease or condition which is improved, ameliorated, inhibited or prevented, or its occurrence rate reduced compared to that without anti-hANGPTL4 antibody treatment (e.g., ANGPTL4-mediated diseases or disorders), by removal, inhibition or reduction of ANGPTL4 activity. Examples of diseases or disorders treatable by the methods of the invention include, but are not limited to, those involving lipid metabolism, such as hyperlipidemia, hyperlipoproteinemia and dyslipidemia, including atherogenic dyslipidemia, diabetic dyslipidemia, hypertriglyceridemia, including severe hypertriglyceridemia with TG>1000 mg/dL, hypercholesterolemia, chylomicronemia, mixed dyslipidemia (obesity, metabolic syndrome, diabetes, etc.), lipodystrophy, lipoatrophy, and the like, which are caused by, for example, decreased LPL activity and/or LPL deficiency, decreased LDL receptor activity and/or LDL receptor deficiency, altered ApoC2, ApoE deficiency, increased ApoB, increased production and/or decreased elimination of very low-density lipoprotein (VLDL), certain drug treatment (e.g., glucocorticoid treatment-induced dyslipidemia), any genetic predisposition, diet, life style, and the like. The methods of the invention can also prevent or treat diseases or disorders associated with or resulting from hyperlipidemia, hyperlipoproteinemia, and/or dyslipidemia, including, but not limited to, cardiovascular diseases or disorders, such as atherosclerosis, aneurysm, hypertension, angina, stroke, cerebrovascular diseases, congestive heart failure, coronary artery diseases, myocardial infarction, peripheral vascular diseases, and the like; acute pancreatitis; nonalcoholic steatohepatitis (NASH); blood sugar disorders, such as diabetes; obesity, and the like.
Other examples of diseases or disorders treatable by the methods of the invention include cancer/tumor as well as non-neoplastic angiogenesis-associated diseases or disorders, including ocular angiogenic diseases or disorders, such as age-related macular degeneration, central retinal vein occlusion or branch retinal vein occlusion, diabetic retinopathy, retinopathy of prematurity, and the like, inflammatory diseases or disorders, such as arthritis, rheumatoid arthritis (RA), psoriasis, and the like.
Other embodiments will become apparent from a review of the ensuing detailed description.
BRIEF DESCRIPTION OF THE FIGURE
FIG. 1 shows a sequence alignment of heavy chain variable regions (HCVR) of antibodies H1H268P, H1H284P, H1H291P AND H1H292P.
FIG. 2 shows a sequence alignment of light chain variable regions (LCVR) of antibodies H1H268P, H1H284P, H1H291P AND H1H292P.
FIGS. 3A and 3B show the pharmacokinetic clearance of anti-ANGPTL4 antibodies in wild-type mice ( FIG. 3A ) and in transgenic mice expressing human ANGPTL4 [hAngptl4(+/+) mice; or “humanized ANGPTL4 mice”] ( FIG. 3B ). H4H268P2 (□); H4H284P (▴); and hIgG4 control (●).
FIG. 4 shows the effect of anti-ANGPTL4 antibody, H4H268P2, on serum triglyceride (TG) levels in humanized ANGPTL4 mice crossed to ApoE null mice. Percent (%) changes of serum TG levels by H4H268P2, compared to control antibody with irrelevant specificity, are shown. Control Ab (∘); and H4H268P2 (▪).
FIG. 5 shows the effects of anti-ANGPTL4 antibody H4H268P2 and TG-reducing drug fenofibrate, each alone or in combination, on serum TG levels in humanized ANGPTL4 mice.
FIG. 6 shows the results of phase I pilot study on effects of anti-ANGPTL4 antibodies on fasting serum TG levels, among other lipids, in obese rhesus monkeys ( Macaca mulatta ). All monkeys received a vehicle (10 mM histidine, pH 6) intravenous (IV) infusion on Day −5 and either H4H268P2 (n=3) (●) or H4H284P (n=3) (□) at 10 mg/kg IV on Day O, Serum samples were collected from the baseline period through Day 35 post-dosing. The average baseline for each animal was determined based on the samples taken on Days −7, −5 and 0, and percent (%) changes of serum TG levels from the baseline determined and averaged for each Ab group.
FIG. 7 shows the results of phase II pilot study on effects of anti-ANGPTL4 antibody H4H268P2 on fasting serum TG levels in obese monkeys, as described for FIG. 6 , except that the step of vehicle infusion was omitted. The average baseline was obtained for each monkey based on the samples taken on Days −7, −3 and 0. Monkeys were divided into Groups based on their baselines: A. TG<150 mg/dL (n=3; □); B. 150 mg/dL<TG<500 mg/dL (n=4; ●); and C. TG>1000 mg/dL (n=1; ∇). Percent (%) changes of fasting TG levels from the baseline were determined for each monkey and averaged for each Group.
Error bars in all graphs indicate mean±SEM.
DETAILED DESCRIPTION
Before the present invention is described in detail, it is to be understood that this invention is not limited to particular methods, and experimental conditions described, as such methods and conditions may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference in their entirety.
DEFINITIONS
The term “human angiopoietin-like protein 4” or “hANGPTL4”, as used herein, refers to hANGPTL4 having the nucleic acid sequence shown in SEQ ID NO:475 and the amino acid sequence of SEQ ID NO:476, or a biologically active fragment thereof.
The term “antibody”, as used herein, is intended to refer to immunoglobulin molecules comprised of four polypeptide chains, two heavy (H) chains and two light (L) chains inter-connected by disulfide bonds. Each heavy chain is comprised of a heavy chain variable region (HCVR) and a heavy chain constant region (C H ; comprised of domains C H 1, C H 2 and C H 3). Each light chain is comprised of a light chain variable region (LCVR) and a light chain constant region (C L ). The HCVR and LCVR can be further subdivided into regions of hypervariability, termed complementarity determining regions (CDR), interspersed with regions that are more conserved, termed framework regions (FR). Each HCVR and LCVR is composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, and FR4.
Substitution of one or more CDR residues or omission of one or more CDRs is also possible. Antibodies have been described in the scientific literature in which one or two CDRs can be dispensed with for binding. Padlan et al. (1995 FASEB J. 9:133-139) analyzed the contact regions between antibodies and their antigens, based on published crystal structures, and concluded that only about one fifth to one third of CDR residues actually contact the antigen. Padlan also found many antibodies in which one or two CDRs had no amino acids in contact with an antigen (see also, Vajdos et al. 2002 J Mol Biol 320:415-428).
CDR residues not contacting antigen can be identified based on previous studies (for example, residues H60-H65 in CDRH2 are often not required), from regions of Kabat CDRs lying outside Chothia CDRs, by molecular modeling and/or empirically. If a CDR or residue(s) thereof is omitted, it is usually substituted with an amino acid occupying the corresponding position in another human antibody sequence or a consensus of such sequences. Positions for substitution within CDRs and amino acids to substitute can also be selected empirically. Empirical substitutions can be conservative or non-conservative substitutions.
The term “human antibody”, as used herein, is intended to include antibodies having variable and constant regions derived from human germline immunoglobulin sequences. The human mAbs of the invention may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo), for example in the CDRs and in particular CDR3. However, the term “human antibody”, as used herein, is not intended to include mAbs in which CDR sequences derived from the germline of another mammalian species (e.g., mouse), have been grafted onto human FR sequences.
The fully-human anti-hANGPTL4 antibodies disclosed herein may comprise one or more amino acid substitutions, insertions and/or deletions in the framework and/or CDR regions of the heavy and light chain variable domains as compared to the corresponding germline sequences. Such mutations can be readily ascertained by comparing the amino acid sequences disclosed herein to germline sequences available from, for example, public antibody sequence databases. The present invention includes antibodies, and antigen-binding fragments thereof, which are derived from any of the amino acid sequences disclosed herein, wherein one or more amino acids within one or more framework and/or CDR regions are mutated to the corresponding residue(s) of the germline sequence from which the antibody was derived, or to the corresponding residue(s) of another human germline sequence, or to a conservative amino acid substitution of the corresponding germline residues(s) (such sequence changes are referred to herein collectively as “germline mutations”). A person of ordinary skill in the art, starting with the heavy and light chain variable region sequences disclosed herein, can easily produce numerous antibodies and antigen-binding fragments which comprise one or more individual germline back-mutations or combinations thereof. In certain embodiments, all of the framework and/or CDR residues within the V H and/or V L domains are mutated back to the residues found in the original germline sequence from which the antibody was derived. In other embodiments, only certain residues are mutated back to the original germline sequence, e.g., only the mutated residues found within the first 8 amino acids of FR1 or within the last 8 amino acids of FR4, or only the mutated residues found within CDR1, CDR2 or CDR3. In other embodiments, one or more of the framework and/or CDR residue(s) are mutated to the corresponding residue(s) of a different germline sequence (i.e., a germline sequence that is different from the germline sequence from which the antibody was originally derived). Furthermore, the antibodies of the present invention may contain any combination of two or more germline mutations within the framework and/or CDR regions, e.g., wherein certain individual residues are mutated to the corresponding residues of a particular germline sequence while certain other residues that differ from the original germline sequence are maintained or are mutated to the corresponding residue of a different germline sequence. Once obtained, antibodies and antigen-binding fragments that contain one or more germline mutations can be easily tested for one or more desired property such as, improved binding specificity, increased binding affinity, improved or enhanced antagonistic or agonistic biological properties (as the case may be), reduced immunogenicity, etc. Antibodies and antigen-binding fragments obtained in this general manner are encompassed within the present invention.
The present invention also includes anti-ANGPTL4 antibodies comprising variants of any of the HCVR, LCVR, and/or CDR amino acid sequences disclosed herein having one or more conservative substitutions. For example, the present invention includes anti-ANGPTL4 antibodies having HCVR, LCVR, and/or CDR amino acid sequences with, e.g., 10 or fewer, 8 or fewer, 6 or fewer, 4 or fewer, 2 or 1, conservative amino acid substitution(s) relative to any of the HCVR, LCVR, and/or CDR amino acid sequences disclosed herein. In one embodiment, a HCVR comprises the amino acid sequence of SEQ ID NO:487 with 10 or fewer conservative amino acid substitutions therein. In another embodiment, a HCVR comprises the amino acid sequence of SEQ ID NO:487 with 8 or fewer conservative amino acid substitutions therein. In another embodiment, a HCVR comprises the amino acid sequence of SEQ ID NO:487 with 6 or fewer conservative amino acid substitutions therein. In another embodiment, a HCVR comprises the amino acid sequence of SEQ ID NO:487 with 4 or fewer conservative amino acid substitutions therein. In yet another embodiment, a HCVR comprises the amino acid sequence of SEQ ID NO:487 with 2 or 1 conservative amino acid substitution(s) therein. In one embodiment, a LCVR comprises the amino acid sequence of SEQ ID NO:44 with 10 or fewer conservative amino acid substitutions therein. In another embodiment, a LCVR comprises the amino acid sequence of SEQ ID NO:44 with 8 or fewer conservative amino acid substitutions therein. In another embodiment, a LCVR comprises the amino acid sequence of SEQ ID NO:44 with 6 or fewer conservative amino acid substitutions therein. In another embodiment, a LCVR comprises the amino acid sequence of SEQ ID NO:44 with 4 or fewer conservative amino acid substitutions therein. In yet another embodiment, a LCVR comprises the amino acid sequence of SEQ ID NO:44 with 2 or 1 conservative amino acid substitution(s) therein.
Unless specifically indicated otherwise, the term “antibody,” as used herein, shall be understood to encompass antibody molecules comprising two immunoglobulin heavy chains and two immunoglobulin light chains (i.e., “full antibody molecules”) as well as antigen-binding fragments thereof. The terms “antigen-binding portion” of an antibody, “antigen-binding fragment” of an antibody, and the like, as used herein, include any naturally occurring, enzymatically obtainable, synthetic, or genetically engineered polypeptide or glycoprotein that specifically binds an antigen to form a complex. Antigen-binding fragments of an antibody may be derived, e.g., from full antibody molecules using any suitable standard techniques such as proteolytic digestion or recombinant genetic engineering techniques involving the manipulation and expression of DNA encoding antibody variable and (optionally) constant domains. Such DNA is known and/or is readily available from, e.g., commercial sources, DNA libraries (including, e.g., phage-display antibody libraries), or can be synthesized. The DNA may be sequenced and manipulated chemically or by using molecular biology techniques, for example, to arrange one or more variable and/or constant domains into a suitable configuration, or to introduce codons, create cysteine residues, modify, add or delete amino acids, etc.
Non-limiting examples of antigen-binding fragments include: (i) Fab fragments; (ii) F(ab′) 2 fragments; (iii) Fd fragments; (iv) Fv fragments; (v) single-chain Fv (scFv) molecules; (vi) dAb fragments; and (vii) minimal recognition units consisting of the amino acid residues that mimic the hypervariable region of an antibody (e.g., an isolated complementarity determining region (CDR)). Other engineered molecules, such as diabodies, triabodies, tetrabodies and minibodies, are also encompassed within the expression “antigen-binding fragment,” as used herein.
An antigen-binding fragment of an antibody will typically comprise at least one variable domain. The variable domain may be of any size or amino acid composition and will generally comprise at least one CDR which is adjacent to or in frame with one or more framework sequences. In antigen-binding fragments having a V H domain associated with a V L domain, the V H and V L domains may be situated relative to one another in any suitable arrangement. For example, the variable region may be dimeric and contain V H -V H , V H -V L or V L -V L dimers. Alternatively, the antigen-binding fragment of an antibody may contain a monomeric V H or V L domain.
In certain embodiments, an antigen-binding fragment of an antibody may contain at least one variable domain covalently linked to at least one constant domain. Non-limiting, exemplary configurations of variable and constant domains that may be found within an antigen-binding fragment of an antibody of the present invention include: (i) V H -C H 1; (ii) V H -C H 2; (iii) V H -C H 3; (iv) V H -C H 1-C H 2; (v) V H -C H 1-C H 2-C H 3; (vi) V H -C H 2-C H 3; (vii) V H -C L ; (viii) V L -C H 1; (ix) V L -C H 2; (X) V L -C H 3; (xi) V L -C H 1-C H 2; (xii) V L -C H 1-C H 2-C H 3; (xiii) V L -C H 2-C H 3; and (xiv) V L -C L . In any configuration of variable and constant domains, including any of the exemplary configurations listed above, the variable and constant domains may be either directly linked to one another or may be linked by a full or partial hinge or linker region. A hinge region may consist of at least 2 (e.g., 5, 10, 15, 20, 40, 60 or more) amino acids which result in a flexible or semi-flexible linkage between adjacent variable and/or constant domains in a single polypeptide molecule. Moreover, an antigen-binding fragment of an antibody of the present invention may comprise a homo-dimer or hetero-dimer (or other multimer) of any of the variable and constant domain configurations listed above in non-covalent association with one another and/or with one or more monomeric V H or V L domain (e.g., by disulfide bond(s)).
As with full antibody molecules, antigen-binding fragments may be monospecific or multispecific (e.g., bispecific). A multispecific antigen-binding fragment of an antibody will typically comprise at least two different variable domains, wherein each variable domain is capable of specifically binding to a separate antigen or to a different epitope on the same antigen. Any multispecific antibody format, including the exemplary bispecific antibody formats disclosed herein, may be adapted for use in the context of an antigen-binding fragment of an antibody of the present invention using routine techniques available in the art.
In certain embodiments, antibody or antibody fragments of the invention may be conjugated to a therapeutic moiety (“immunoconjugate”), such as a cytotoxin, a chemotherapeutic drug, an immunosuppressant or a radioisotope.
The term “specifically binds,” or the like, means that an antibody or antigen-binding fragment thereof forms a complex with an antigen that is relatively stable under physiological conditions. Specific binding can be characterized by an equilibrium dissociation constant (K D ) of about 1×10 −6 M or less (i.e., a smaller K D denotes a tighter binding). Methods for determining whether two molecules specifically bind are well known in the art and include, for example, equilibrium dialysis, surface plasmon resonance, and the like. An isolated antibody that specifically binds hANGPTL4 may, however, exhibit cross-reactivity to other antigens, such as ANGPTL4 molecules from other species, for example, cynomolgus monkey ANGPTL4, and/or hANGPTL3 having the amino acid sequence of SEQ ID NO:485. Moreover, multi-specific antibodies (e.g., bispecifics) that bind to hANGPTL4 and one or more additional antigens are nonetheless considered antibodies that “specifically bind” hANGPTL4, as used herein.
The term “high affinity” antibody refers to those antibodies having a binding affinity to hANGPTL4, expressed as K D , of about 1×10 −9 M or less, about 0.5×10 −9 M or less, about 0.25×10 −9 M or less, about 1×10 −10 M or less, or about 0.5×10 −10 M or less, as measured by surface plasmon resonance, e.g., BIACORE™ or solution-affinity ELISA.
The term “K D ”, as used herein, is intended to refer to the equilibrium dissociation constant of a particular antibody-antigen interaction.
By the term “slow off rate”, “Koff” or “k d ” is meant an antibody that dissociates from hANGPTL4 with a rate constant of 1×10 −3 s −1 or less, preferably 1×10 −4 s −1 or less, as determined by surface plasmon resonance, e.g., BIACORE™
By the term “intrinsic affinity constant” or “k a ” is meant an antibody that associates with hANGPTL4 at a rate constant of about 1×10 −3 M −1 s −1 or higher, as determined by surface plasmon resonance, e.g., BIACORE™
An “isolated antibody”, as used herein, is intended to refer to an antibody that is substantially free of other mAbs having different antigenic specificities (e.g., an isolated antibody that specifically binds hANGPTL4 is substantially free of mAbs that specifically bind antigens other than hANGPTL4). An isolated antibody that specifically binds hANGPTL4 may, however, have cross-reactivity to other antigens, such as ANGPTL4 molecules from other species, such as cynomolgus monkey, and/or other related proteins, such as human ANGPTL3.
A “neutralizing antibody”, as used herein (or an “antibody that neutralizes ANGPTL4 activity”), is intended to refer to an antibody whose binding to ANGPTL4 results in inhibition of at least one biological activity of ANGPTL4. This inhibition of the biological activity of ANGPTL4 can be assessed by measuring one or more indicators of ANGPTL4 biological activity by one or more of several standard in vitro or in vivo assays known in the art (also see examples below).
The term “surface plasmon resonance”, as used herein, refers to an optical phenomenon that allows for the analysis of real-time biospecific interactions by detection of alterations in protein concentrations within a biosensor matrix, for example using the BIACORE™ system (Pharmacia Biosensor AB, Uppsala, Sweden and Piscataway, N.J.).
The term “epitope” is a region of an antigen that is bound by an antibody. Epitopes may be defined as structural or functional. Functional epitopes are generally a subset of the structural epitopes and have those residues that directly contribute to the affinity of the interaction. Epitopes may also be conformational, that is, composed of non-linear amino acids. In certain embodiments, epitopes may include determinants that are chemically active surface groupings of molecules such as amino acids, sugar side chains, phosphoryl groups, or sulfonyl groups, and, in certain embodiments, may have specific three-dimensional structural characteristics, and/or specific charge characteristics.
The term “substantial identity” or “substantially identical,” when referring to a nucleic acid or fragment thereof, indicates that, when optimally aligned with appropriate nucleotide insertions or deletions with another nucleic acid (or its complementary strand), there is nucleotide sequence identity in at least about 90%, and more preferably at least about 95%, 96%, 97%, 98% or 99% of the nucleotide bases, as measured by any well-known algorithm of sequence identity, such as FASTA, BLAST or GAP, as discussed below.
As applied to polypeptides, the term “substantial similarity” or “substantially similar” means that two peptide sequences, when optimally aligned, such as by the programs GAP or BESTFIT using default gap weights, share at least 90% sequence identity, even more preferably at least 95%, 98% or 99% sequence identity. Preferably, residue positions which are not identical differ by conservative amino acid substitutions. A “conservative amino acid substitution” is one in which an amino acid residue is substituted by another amino acid residue having a side chain (R group) with similar chemical properties (e.g., charge or hydrophobicity). In general, a conservative amino acid substitution will not substantially change the functional properties of a protein. In cases where two or more amino acid sequences differ from each other by conservative substitutions, the percent or degree of similarity may be adjusted upwards to correct for the conservative nature of the substitution. Means for making this adjustment are well known to those of skill in the art. See, e.g., Pearson (1994) Methods Mol. Biol. 24: 307-331. Examples of groups of amino acids that have side chains with similar chemical properties include 1) aliphatic side chains: glycine, alanine, valine, leucine and isoleucine; 2) aliphatic-hydroxyl side chains: serine and threonine; 3) amide-containing side chains: asparagine and glutamine; 4) aromatic side chains: phenylalanine, tyrosine, and tryptophan; 5) basic side chains: lysine, arginine, and histidine; 6) acidic side chains: aspartate and glutamate, and 7) sulfur-containing side chains: cysteine and methionine. Preferred conservative amino acids substitution groups are: valine-leucine-isoleucine, phenylalanine-tyrosine, lysine-arginine, alanine-valine, glutamate-aspartate, and asparagine-glutamine. Alternatively, a conservative replacement is any change having a positive value in the PAM250 log-likelihood matrix disclosed in Gonnet et al. (1992) Science 256: 1443 45. A “moderately conservative” replacement is any change having a nonnegative value in the PAM250 log-likelihood matrix.
Sequence similarity for polypeptides is typically measured using sequence analysis software. Protein analysis software matches similar sequences using measures of similarity assigned to various substitutions, deletions and other modifications, including conservative amino acid substitutions. For instance, GCG software contains programs such as GAP and BESTFIT which can be used with default parameters to determine sequence homology or sequence identity between closely related polypeptides, such as homologous polypeptides from different species of organisms or between a wild type protein and a mutein thereof. See, e.g., GCG Version 6.1. Polypeptide sequences also can be compared using FASTA with default or recommended parameters; a program in GCG Version 6.1. FASTA (e.g., FASTA2 and FASTA3) provides alignments and percent sequence identity of the regions of the best overlap between the query and search sequences (Pearson (2000) supra). Another preferred algorithm when comparing a sequence of the invention to a database containing a large number of sequences from different organisms is the computer program BLAST, especially BLASTP or TBLASTN, using default parameters. See, e.g., Altschul et al. (1990) J. Mol. Biol. 215: 403 410 and (1997) Nucleic Acids Res. 25:3389 402.
By the phrase “therapeutically effective amount” is meant an amount that produces the desired effect for which it is administered. The exact amount will depend on the purpose of the treatment, the age and the size of a subject treated, the route of administration, and the like, and will be ascertainable by one skilled in the art using known techniques (see, for example, Lloyd (1999) The Art, Science and Technology of Pharmaceutical Compounding).
Preparation of Human Antibodies
Methods for generating human antibodies in transgenic mice are known in the art. Any such known methods can be used in the context of the present invention to make human antibodies that specifically bind to ANGPTL4.
Using VELOCIMMUNE™ technology or any other known method for generating monoclonal antibodies, high affinity chimeric antibodies to ANGPTL4 are initially isolated having a human variable region and a mouse constant region. As in the experimental section below, the antibodies are characterized and selected for desirable characteristics, including affinity, selectivity, epitope, and the like.
In general, the antibodies of the instant invention possess very high affinities, typically possessing K D of from about 10 −12 M through about 10 −9 M, when measured by binding to antigen either immobilized on solid phase or in solution phase. The mouse constant regions are replaced with desired human constant regions, for example, wild-type IgG1 (SEQ ID NO:481) or IgG4 (SEQ ID NO:482), or modified IgG1 or IgG4 (for example, SEQ ID NO:483), to generate the fully human antibodies of the invention. While the constant region selected may vary according to specific use, high affinity antigen-binding and target specificity characteristics of the antibodies reside in the variable region.
Epitope Mapping and Related Technologies
To screen for antibodies that bind to a particular epitope, a routine cross-blocking assay such as that described in Antibodies , Harlow and Lane (Cold Spring Harbor Press, Cold Spring Harb., N.Y.) can be performed. Other methods include alanine scanning mutants, peptide blots (Reineke (2004) Methods Mol Biol 248:443-63), or peptide cleavage analysis. In addition, methods such as epitope excision, epitope extraction and chemical modification of antigens can be employed (Tomer (2000) Protein Science 9: 487-496).
The term “epitope” refers to a site on an antigen to which B and/or T cells respond. B-cell epitopes can be formed both from contiguous amino acids or noncontiguous amino acids juxtaposed by tertiary folding of a protein. Epitopes formed from contiguous amino acids are typically retained on exposure to denaturing solvents, whereas epitopes formed by tertiary folding are typically lost on treatment with denaturing solvents. An epitope typically includes at least 3, and more usually, at least 5 or 8-10 amino acids in a unique spatial conformation.
Modification-Assisted Profiling (MAP), also known as Antigen Structure-based Antibody Profiling (ASAP) is a method that categorizes large numbers of monoclonal antibodies (mAbs) directed against the same antigen according to the similarities of the binding profile of each antibody to chemically or enzymatically modified antigen surfaces (US 2004/0101920). Each category may reflect a unique epitope either distinctly different from or partially overlapping with epitope represented by another category. This technology allows rapid filtering of genetically identical mAbs, such that characterization can be focused on genetically distinct mAbs. When applied to hybridoma screening, MAP may facilitate identification of rare hybridoma clones that produce mAbs having the desired characteristics. MAP may be used to sort the anti-ANGPTL4 mAbs of the invention into groups of mAbs binding different epitopes.
ANGPTL4 contains an amino-terminal coiled-coil domain and a carboxyl-terminal fibrinogen like domain and the full-length ANGPTL4 protein forms an oligomer held by intermolecular disulfide bonds (Ge et al., 2004 , J Bio Chem 279(3):2038-2045). It has been reported that the N-terminal coiled-coil domain mediates ANGPTL4's oligomerization (Ge et al., supra) and is also important in the inhibition of LPL activity (Ge et al., 2005 , J Lipid Res 46:1484-1490; and Ono et al., 2003 , J Biol Chem 278:41804-41809). Thus, in certain embodiments, the anti-hANGPTL4 antibody or antigen-binding fragment of an antibody binds an epitope within the N-terminal coiled-coil domain (residues 1-123) of hANGPTL4 (SEQ ID NO:476). In certain embodiments, anti-hANGPTL4 antibody or fragment thereof binds an epitope within the region from about residue 1 to about residue 25, from about residue 25 to about residue 50, from about residue 50 to about residue 75, from about residue 75 to about residue 100, from about residue 100 to about residue 125, from about residue 125 to about residue 150, of hANGPTL4 (SEQ ID NO:476). In some embodiments, the antibody or antibody fragment binds an epitope which includes more than one of the enumerated epitopes within the N-terminal coiled-coil domain of hANGPTL4. In other embodiments, hANGPTL4 antibody or fragment thereof binds one or more fragments of hANGPTL4, for example, a fragment from residues 26 to 406, from residues 26 to 148, from residues 34 to 66, and/or residues 165 to 406, of SEQ ID NO:476.
The present invention includes hANGPTL4 antibodies that bind to the same epitope as any of the specific exemplary antibodies described herein. Likewise, the present invention also includes anti-hANGPTL4 antibodies that compete for binding to hANGPTL4 or a hANGPTL4 fragment with any of the specific exemplary antibodies described herein.
One can easily determine whether an antibody binds to the same epitope as, or competes for binding with, a reference anti-hANGPTL4 antibody by using routine methods known in the art. For example, to determine if a test antibody binds to the same epitope as a reference anti-hANGPTL4 antibody of the invention, the reference antibody is allowed to bind to a hANGPTL4 protein or peptide under saturating conditions. Next, the ability of a test antibody to bind to the hANGPTL4 molecule is assessed. If the test antibody is able to bind to hANGPTL4 following saturation binding with the reference anti-hANGPTL4 antibody, it can be concluded that the test antibody binds to a different epitope than the reference anti-hANGPTL4 antibody. On the other hand, if the test antibody is not able to bind to the hANGPTL4 molecule following saturation binding with the reference anti-hANGPTL4 antibody, then the test antibody may bind to the same epitope as the epitope bound by the reference anti-hANGPTL4 antibody of the invention.
To determine if an antibody competes for binding with a reference anti-hANGPTL4 antibody, the above-described binding methodology is performed in two orientations: In a first orientation, the reference antibody is allowed to bind to a hANGPTL4 molecule under saturating conditions followed by assessment of binding of the test antibody to the hANGPTL4 molecule. In a second orientation, the test antibody is allowed to bind to a hANGPTL4 molecule under saturating conditions followed by assessment of binding of the reference antibody to the ANGPTL4 molecule. If, in both orientations, only the first (saturating) antibody is capable of binding to the ANGPTL4 molecule, then it is concluded that the test antibody and the reference antibody compete for binding to hANGPTL4. As will be appreciated by a person of ordinary skill in the art, an antibody that competes for binding with a reference antibody may not necessarily bind to the identical epitope as the reference antibody, but may sterically block binding of the reference antibody by binding an overlapping or adjacent epitope.
Two antibodies bind to the same or overlapping epitope if each competitively inhibits (blocks) binding of the other to the antigen. That is, a 1-, 5-, 10-, 20- or 100-fold excess of one antibody inhibits binding of the other by at least 50% but preferably 75%, 90% or even 99% as measured in a competitive binding assay (see, e.g., Junghans et al., Cancer Res, 1990:50:1495-1502). Alternatively, two antibodies have the same epitope if essentially all amino acid mutations in the antigen that reduce or eliminate binding of one antibody reduce or eliminate binding of the other. Two antibodies have overlapping epitopes if some amino acid mutations that reduce or eliminate binding of one antibody reduce or eliminate binding of the other.
Additional routine experimentation (e.g., peptide mutation and binding analyses) can then be carried out to confirm whether the observed lack of binding of the test antibody is in fact due to binding to the same epitope as the reference antibody or if steric blocking (or another phenomenon) is responsible for the lack of observed binding. Experiments of this sort can be performed using ELISA, RIA, surface plasmon resonance, flow cytometry or any other quantitative or qualitative antibody-binding assay available in the art.
Immunoconjugates
The invention encompasses a human anti-ANGPTL4 monoclonal antibody conjugated to a therapeutic moiety (“immunoconjugate”), such as a cytotoxin, a chemotherapeutic drug, an immunosuppressant or a radioisotope. Cytotoxin agents include any agent that is detrimental to cells. Examples of suitable cytotoxin agents and chemotherapeutic agents for forming immunoconjugates are known in the art, see for example, WO 05/103081.
Bispecifics
The antibodies of the present invention may be monospecific, bispecific, or multispecific. Multispecific mAbs may be specific for different epitopes of one target polypeptide or may contain antigen-binding domains specific for more than one target polypeptide. See, e.g., Tutt et al. (1991) J. Immunol. 147:60-69. The human anti-hANGPTL4 mAbs can be linked to or co-expressed with another functional molecule, e.g., another peptide or protein. For example, an antibody or fragment thereof can be functionally linked (e.g., by chemical coupling, genetic fusion, noncovalent association or otherwise) to one or more other molecular entities, such as another antibody or antibody fragment, to produce a bispecific or a multispecific antibody with a second binding specificity.
An exemplary bi-specific antibody format that can be used in the context of the present invention involves the use of a first immunoglobulin (Ig) C H 3 domain and a second Ig C H 3 domain, wherein the first and second Ig C H 3 domains differ from one another by at least one amino acid, and wherein at least one amino acid difference reduces binding of the bispecific antibody to Protein A as compared to a bi-specific antibody lacking the amino acid difference. In one embodiment, the first Ig C H 3 domain binds Protein A and the second Ig C H 3 domain contains a mutation that reduces or abolishes Protein A binding such as an H95R modification (by IMGT exon numbering; H435R by EU numbering). The second C H 3 may further comprise a Y96F modification (by IMGT; Y436F by EU). Further modifications that may be found within the second C H 3 include: D16E, L18M, N44S, K52N, V57M, and V821 (by IMGT; D356E, L358M, N384S, K392N, V397M, and V4221 by EU) in the case of IgG1 antibodies; N44S, K52N, and V821 (IMGT; N384S, K392N, and V422I by EU) in the case of IgG2 antibodies; and Q15R, N44S, K52N, V57M, R69K, E79Q, and V82I (by IMGT; Q355R, N384S, K392N, V397M, R409K, E419Q, and V4221 by EU) in the case of IgG4 antibodies. Variations on the bi-specific antibody format described above are contemplated within the scope of the present invention.
Bioequivalents
The anti-hANGPTL4 antibodies and antibody fragments of the present invention encompass proteins having amino acid sequences that vary from those of the described mAbs, but that retain the ability to bind human ANGPTL4. Such variant mAbs and antibody fragments comprise one or more additions, deletions, or substitutions of amino acids when compared to parent sequence, but exhibit biological activity that is essentially equivalent to that of the described mAbs. Likewise, the hANGPTL4 antibody-encoding DNA sequences of the present invention encompass sequences that comprise one or more additions, deletions, or substitutions of nucleotides when compared to the disclosed sequence, but that encode an anti-hANGPTL4 antibody or antibody fragment that is essentially bioequivalent to an anti-hANGPTL4 antibody or antibody fragment of the invention. Examples of such variant amino acid and DNA sequences are discussed above.
Two antigen-binding proteins, or antibodies, are considered bioequivalent if, for example, they are pharmaceutical equivalents or pharmaceutical alternatives whose rate and extent of absorption do not show a significant difference when administered at the same molar dose under similar experimental conditions, either single does or multiple dose. Some antibodies will be considered equivalents or pharmaceutical alternatives if they are equivalent in the extent of their absorption but not in their rate of absorption and yet may be considered bioequivalent because such differences in the rate of absorption are intentional and are reflected in the labeling, are not essential to the attainment of effective body drug concentrations on, e.g., chronic use, and are considered medically insignificant for the particular drug product studied. In one embodiment, two antigen-binding proteins are bioequivalent if there are no clinically meaningful differences in their safety, purity, and potency.
In one embodiment, two antigen-binding proteins are bioequivalent if a patient can be switched one or more times between the reference product and the biological product without an expected increase in the risk of adverse effects, including a clinically significant change in immunogenicity, or diminished effectiveness, as compared to continued therapy without such switching.
In one embodiment, two antigen-binding proteins are bioequivalent if they both act by a common mechanism or mechanisms of action for the condition or conditions of use, to the extent that such mechanisms are known.
Bioequivalence may be demonstrated by in vivo and in vitro methods. Bioequivalence measures include, e.g., (a) an in vivo test in humans or other mammals, in which the concentration of the antibody or its metabolites is measured in blood, plasma, serum, or other biological fluid as a function of time; (b) an in vitro test that has been correlated with and is reasonably predictive of human in vivo bioavailability data; (c) an in vivo test in humans or other mammals in which the appropriate acute pharmacological effect of the antibody (or its target) is measured as a function of time; and (d) in a well-controlled clinical trial that establishes safety, efficacy, or bioavailability or bioequivalence of an antibody.
Bioequivalent variants of anti-hANGPTL4 antibodies of the invention may be constructed by, for example, making various substitutions of residues or sequences or deleting terminal or internal residues or sequences not needed for biological activity. For example, cysteine residues not essential for biological activity can be deleted or replaced with other amino acids to prevent formation of unnecessary or incorrect intramolecular disulfide bridges upon renaturation.
Therapeutic Administration and Formulations
The invention provides therapeutic compositions comprising the anti-hANGPTL4 antibodies or antigen-binding fragments thereof of the present invention and the therapeutic methods using the same. The administration of therapeutic compositions in accordance with the invention will be administered with suitable carriers, excipients, and other agents that are incorporated into formulations to provide improved transfer, delivery, tolerance, and the like. A multitude of appropriate formulations can be found in the formulary known to all pharmaceutical chemists: Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa. These formulations include, for example, powders, pastes, ointments, jellies, waxes, oils, lipids, lipid (cationic or anionic) containing vesicles (such as LIPOFECTIN™), DNA conjugates, anhydrous absorption pastes, oil-in-water and water-in-oil emulsions, emulsions carbowax (polyethylene glycols of various molecular weights), semi-solid gels, and semi-solid mixtures containing carbowax. See also Powell et al. “Compendium of excipients for parenteral formulations” PDA (1998) J Pharm Sci Technol 52:238-311.
The dose may vary depending upon the age and the size of a subject to be administered, target disease, the purpose of the treatment, conditions, route of administration, and the like. When the antibody of the present invention is used for treating various conditions and diseases directly or indirectly associated with ANGPTL4, including hypercholesterolemia, disorders associated with LDL and apolipoprotein B, and lipid metabolism disorders, and the like, in an adult patient, it is advantageous to intravenously or subcutaneously administer the antibody of the present invention at a single dose of about 0.01 to about 20 mg/kg body weight, more preferably about 0.02 to about 7, about 0.03 to about 5, or about 0.05 to about 3 mg/kg body weight. Depending on the severity of the condition, the frequency and the duration of the treatment can be adjusted. In certain embodiments, the antibody or antigen-binding fragment thereof of the invention can be administered as an initial dose of at least about 0.1 mg to about 800 mg, about 1 to about 500 mg, about 5 to about 300 mg, or about 10 to about 200 mg, to about 100 mg, or to about 50 mg. In certain embodiments, the initial dose may be followed by administration of a second or a plurality of subsequent doses of the antibody or antigen-binding fragment thereof in an amount that can be approximately the same or less than that of the initial dose, wherein the subsequent doses are separated by at least 1 day to 3 days; at least one week, at least 2 weeks; at least 3 weeks; at least 4 weeks; at least 5 weeks; at least 6 weeks; at least 7 weeks; at least 8 weeks; at least 9 weeks; at least 10 weeks; at least 12 weeks; or at least 14 weeks.
Various delivery systems are known and can be used to administer the pharmaceutical composition of the invention, e.g., encapsulation in liposomes, microparticles, microcapsules, recombinant cells capable of expressing the mutant viruses, receptor mediated endocytosis (see, e.g., Wu et al. (1987) J. Biol. Chem. 262:4429-4432). Methods of introduction include, but are not limited to, intradermal, intramuscular, intraperitoneal, intravenous, subcutaneous, intranasal, epidural, and oral routes. The composition may be administered by any convenient route, for example by infusion or bolus injection, by absorption through epithelial or mucocutaneous linings (e.g., oral mucosa, rectal and intestinal mucosa, etc.) and may be administered together with other biologically active agents. Administration can be systemic or local.
The pharmaceutical composition can be also delivered in a vesicle, in particular a liposome (see Langer (1990) Science 249:1527-1533; Treat et al. (1989) in Liposomes in the Therapy of Infectious Disease and Cancer, Lopez Berestein and Fidler (eds.), Liss, New York, pp. 353-365; Lopez-Berestein, ibid., pp. 317-327; see generally ibid.).
In certain situations, the pharmaceutical composition can be delivered in a controlled release system. In one embodiment, a pump may be used (see Langer, supra; Sefton (1987) CRC Crit. Ref. Biomed. Eng. 14:201). In another embodiment, polymeric materials can be used; see, Medical Applications of Controlled Release, Langer and Wise (eds.), CRC Pres., Boca Raton, Fla. (1974). In yet another embodiment, a controlled release system can be placed in proximity of the composition's target, thus requiring only a fraction of the systemic dose (see, e.g., Goodson, in Medical Applications of Controlled Release, supra, vol. 2, pp. 115-138, 1984).
The injectable preparations may include dosage forms for intravenous, subcutaneous, intracutaneous and intramuscular injections, drip infusions, etc. These injectable preparations may be prepared by methods publicly known. For example, the injectable preparations may be prepared, e.g., by dissolving, suspending or emulsifying the antibody or its salt described above in a sterile aqueous medium or an oily medium conventionally used for injections. As the aqueous medium for injections, there are, for example, physiological saline, an isotonic solution containing glucose and other auxiliary agents, etc., which may be used in combination with an appropriate solubilizing agent such as an alcohol (e.g., ethanol), a polyalcohol (e.g., propylene glycol, polyethylene glycol), a nonionic surfactant [e.g., polysorbate 80, HCO-50 (polyoxyethylene (50 mol) adduct of hydrogenated castor oil)], etc. As the oily medium, there are employed, e.g., sesame oil, soybean oil, etc., which may be used in combination with a solubilizing agent such as benzyl benzoate, benzyl alcohol, etc. The injection thus prepared is preferably filled in an appropriate ampoule. A pharmaceutical composition of the present invention can be delivered subcutaneously or intravenously with a standard needle and syringe. In addition, with respect to subcutaneous delivery, a pen delivery device readily has applications in delivering a pharmaceutical composition of the present invention. Such a pen delivery device can be reusable or disposable. A reusable pen delivery device generally utilizes a replaceable cartridge that contains a pharmaceutical composition. Once all of the pharmaceutical composition within the cartridge has been administered and the cartridge is empty, the empty cartridge can readily be discarded and replaced with a new cartridge that contains the pharmaceutical composition. The pen delivery device can then be reused. In a disposable pen delivery device, there is no replaceable cartridge. Rather, the disposable pen delivery device comes prefilled with the pharmaceutical composition held in a reservoir within the device. Once the reservoir is emptied of the pharmaceutical composition, the entire device is discarded.
Numerous reusable pen and autoinjector delivery devices have applications in the subcutaneous delivery of a pharmaceutical composition of the present invention. Examples include, but certainly are not limited to AUTOPEN™ (Owen Mumford, Inc., Woodstock, UK), DISETRONIC™ pen (Disetronic Medical Systems, Burghdorf, Switzerland), HUMALOG MIX 75/25™ pen, HUMALOG™ pen, HUMALIN 70/30™ pen (Eli Lilly and Co., Indianapolis, Ind.), NOVOPEN™ I, II and III (Novo Nordisk, Copenhagen, Denmark), NOVOPEN JUNIOR™ (Novo Nordisk, Copenhagen, Denmark), BD™ pen (Becton Dickinson, Franklin Lakes, N.J.), OPTIPENT™, OPTIPEN PRO™, OPTIPEN STARLET™, and OPTICLIK™ (sanofi-aventis, Frankfurt, Germany), to name only a few. Examples of disposable pen delivery devices having applications in subcutaneous delivery of a pharmaceutical composition of the present invention include, but certainly are not limited to the SOLOSTAR™ pen (sanofi-aventis), the FLEXPEN™ (Novo Nordisk), and the KWIKPEN™ (Eli Lilly).
Advantageously, the pharmaceutical compositions for oral or parenteral use described above are prepared into dosage forms in a unit dose suited to fit a dose of the active ingredients. Such dosage forms in a unit dose include, for example, tablets, pills, capsules, injections (ampoules), suppositories, etc. The amount of the aforesaid antibody contained is generally about 0.1 to about 800 mg per dosage form in a unit dose; especially in the form of injection, the aforesaid antibody is contained in about 1 to about 500 mg, in about 5 to 300 mg, in about 8 to 200 mg, and in about 10 to about 100 mg for the other dosage forms.
Combination Therapies
The invention further provides therapeutic methods for treating diseases or disorders, which is directly or indirectly associated with hANGPTL4, by administering the hANGPTL4 antibody or fragment thereof of the invention in combination with one or more additional therapeutic agents. The additional therapeutic agent may be one or more of any agent that is advantageously combined with the antibody or fragment thereof of the invention, including HMG-CoA reductase inhibitors, such as cerovastatin, atorvastatin, simvastatin, pitavastin, ros uvastatin, fluvastatin, lovastatin, pravastatin, and the like; niacin; various fibrates, such as fenofibrate, bezafibrate, ciprofibrate, clofibrate, gemfibrozil, and the like; LXR transcription factor activators, and the like. Furthermore, the hANGPTL4 antibody or fragment thereof of the invention can be co-administered with other ANGPTL4 inhibitors as well as inhibitors of other molecules, such as ANGPTL3, ANGPTL5, ANGPTL6 and proprotein convertase subtilisin/kexin type 9 (PCSK9), which are involved in lipid metabolism, in particular, cholesterol and/or triglyceride homeostasis. Inhibitors of these molecules include small molecules and antibodies that specifically bind to these molecules and block their activity (see, for example, anti-PCSK9 antibodies disclosed in U.S. 2010/0166768 A1).
Furthermore, the additional therapeutic agent may be one or more anti-cancer agents, such as chemotherapeutic agents, anti-angiogenic agents, growth inhibitory agents, cytotoxic agents, apoptotic agents, and other agents well known in the art to treat cancer or other proliferative diseases or disorders. Examples of anti-cancer agents include, but are not limited to, an anti-mitotic agent, such as docetaxel, paclitaxel, and the like; a platinum-based chemotherapeutic compound, such as cisplatin, carboplatin, iproplatin, oxaliplatin, and the like; or other conventional cytotoxic agent, such as 5-fluorouracil, capecitabine, irinotecan, leucovorin, gemcitabine, and the like, and anti-angiogenic agents, including vascular endothelial growth factor (VEGF) antagonists, such as anti-VEGF antibodies, e.g., bevacizumab (AVASTIN®, Genentech) and a receptor-based blocker of VEGF, e.g., “VEGF trap” described in U.S. Pat. No. 7,070,959, delta-like ligand 4 (DII4) antagonists, such as anti-DII4 antibodies as described in U.S. Patent Application Publication No. 2008/0181899, and a fusion protein containing the extracellular domain of DII4, e.g., DII4-Fc as described in U.S. Patent Application Publication No. 2008/0107648; inhibitors of receptor tyrosine kinases and/or angiogenesis, including sorafenib (NEXAVAR® by Bayer Pharmaceuticals Corp.), sunitinib (SUTENT® by Pfizer), pazopanib (VOTRIENT™ by GlaxoSmithKline), toceranib (PALLADIA™ by Pfizer), vandetanib (ZACTIMA™ by AstraZeneca), cediranib (RECENTIN® by AstraZeneca), regorafenib (BAY 73-4506 by Bayer), axitinib (AG013736 by Pfizer), lestaurtinib (CEP-701 by Cephalon), erlotinib (TARCEVA® by Genentech), gefitinib (IRESSA™ by AstraZeneca), BIBW 2992 (TOVOK™ by Boehringer Ingelheim), lapatinib (TYKERB® by GlaxoSmithKline), neratinib (HKI-272 by Wyeth/Pfizer), and the like, and pharmaceutically acceptable salts, acids or derivatives of any of the above. In addition, other therapeutic agents, such as analgesics, anti-inflammatory agents, including non-steroidal anti-inflammatory drugs (NSAIDS), such as Cox-2 inhibitors, and the like, may be also co-administered with the hANGPTL4 antibody or fragment thereof of the invention so as to ameliorate and/or reduce the symptoms accompanying the underlying cancer/tumor.
The hANGPTL4 antibody or fragment thereof of the invention and the additional therapeutic agent(s) can be co-administered together or separately. Where separate dosage formulations are used, the antibody or fragment thereof of the invention and the additional agents can be administered concurrently, or separately at staggered times, i.e., sequentially, in appropriate orders.
Diagnostic Uses of the Antibodies
The anti-ANGPTL4 antibodies of the present invention can be also used to detect and/or measure ANGPTL4 in a sample, e.g., for diagnostic purposes. For example, an anti-ANGPTL4 Ab or fragment thereof, can be used to diagnose a condition or disease characterized by aberrant expression (e.g., over-expression, under-expression, lack of expression, etc.) of ANGPTL4. Exemplary diagnostic assays for ANGPTL4 may comprise, e.g., contacting a sample obtained from a patient, with an anti-ANGPTL4 Ab of the invention, wherein the anti-ANGPTL4 antibody is labeled with a detectable label or reporter molecule or used to selectively capture and isolate ANGPTL4 protein from patient samples. Alternatively, an unlabeled anti-ANGPTL4 Ab can be used in diagnostic applications in combination with a secondary antibody which is itself detectably labeled. The detectable label or reporter molecule can be a radioisotope, such as 3 H, 14 C, 32 P, 35 S, 131 I or 125 I; a fluorescent or chemiluminescent moiety, such as fluorescein isothiocyanate, or rhodamine; or an enzyme such as alkaline phosphatase, β-galactosidase, horseradish peroxidase, or luciferase. Assays that can be used to detect or measure ANGPTL4 in a sample include enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA), fluorescence-activated cell sorting (FACS), and the like.
EXAMPLES
The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the methods and compositions of the invention, and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers used but some experimental errors and deviations should be accounted for. Unless indicated otherwise, molecular weight is average molecular weight, temperature is in degrees Centigrade, and pressure is at or near atmospheric.
Example 1
Generation of Human Antibodies to Human ANGPTL4
VELOCIMMUNE™ mice were immunized with human ANGPTL4, and the antibody immune response monitored by antigen-specific immunoassay using serum obtained from these mice. Anti-hANGPTL4 expressing B cells were harvested from the spleens of immunized mice shown to have elevated anti-hANGPTL4 antibody titers and were fused with mouse myeloma cells to form hybridomas. The hybridomas were screened and selected to identify cell lines expressing hANGPTL4-specific antibodies using assays as described below. The assays identified several cell lines that produced chimeric anti-hANGPTL4 antibodies designated as H1M222, H1M223, H1M224, H1M225, H1M234 and H1M236.
Human ANGPTL4-specific antibodies were also isolated directly from antigen-immunized B cells without fusion to myeloma cells, as described in U.S. 2007/0280945 A1. Heavy and light chain variable regions were cloned to generate fully human anti-hANGPTL4 antibodies designated as H1H257, H1H268, H1H283, H1H284, H1H285, H1H291, H1H292, H1H295, H1H624, H1H637, H1H638, H1H644 and H1H653. Stable recombinant antibody-expressing CHO cell lines were established.
Example 2
Variable Gene Utilization Analysis
To analyze the structure of antibodies produced, the nucleic acids encoding antibody variable regions were cloned and sequenced. From the nucleic acid sequence and predicted amino acid sequence of the antibodies, gene usage was identified for each Heavy Chain Variable Region (HCVR) and Light Chain Variable Region (LCVR). Table 1 shows the gene usage for selected antibodies in accordance with the invention.
TABLE 1
HCVR
LCVR
Antibody
V H
D H
J H
V K
J K
H1M225
3-9
1-7
1
1-5
2
H1M236
3-9
6-6
5
3-15
5
H1H283
3-13
1-26
4
1-5
1
H1H285
3-13
1-26
4
1-5
1
H1H291
3-13
1-26
4
1-5
1
H1H292
3-13
1-26
4
1-5
1
H1H295
3-13
1-26
4
1-5
1
H1H637
3-13
1-26
4
1-5
1
H1H638
3-13
1-26
4
1-5
1
H1H644
3-13
1-26
4
1-5
1
H1H257
3-13
1-26
4
1-5
1
H1M224
3-13
3-3
4
1-16
3
H1M223
3-15
3-3
4
1-12
3
H1M234
3-15
3-3
4
1-12
3
H1H624
3-23
5-5
6
1-9
3
H1H284
3-30
5-12
6
1-9
4
H1M222
3-33
3-9
5
3-20
4
H1H653
3-33
2-8
6
1-17
2
H1H268
4-34
3-3
4
1-27
4
Table 2 shows the heavy and light chain variable region amino acid sequence pairs of selected anti-hANGPTL4 antibodies and their corresponding antibody identifiers. The N, P and L designations refer to antibodies having heavy and light chains with identical CDR sequences but with sequence variations in regions that fall outside of the CDR sequences (i.e., in the framework regions). Thus, N, P and L variants of a particular antibody have identical CDR sequences within their heavy and light chain variable regions but contain modifications within the framework regions.
TABLE 2
HCVR/LCVR
Name
SEQ ID NOs
H1M222N
314/322
H1M223N
410/418
H1M224N
338/346
H1M225N
362/370
H1M234N
434/442
H1M236N
386/394
H1H236N2
458/394
H1H257N
2/10
H1H268N
26/34
—
—
H1H283N
50/58
H1H284N
74/82
H1H285N
98/106
H1H291N
122/130
H1H292N
146/154
H1H295N
170/178
H1H624N
194/202
H1H637N
218/226
H1H638N
242/250
H1H644N
266/274
H1H653N
290/298
H1M222P
330/332
H1M223P
426/428
H1M224P
354/356
H1M225P
378/380
H1M234P
450/452
H1M236P
402/404
H1H236P2
466/404
H1H257P
18/20
H1H268P
42/44
H4H268P2
487/44
H1H283P
66/68
H1H284P
90/92
H1H285P
114/116
H1H291P
138/140
H1H292P
162/164
H1H295P
186/188
H1H624P
210/212
H1H637P
234/236
H1H638P
258/260
H1H644P
282/284
H1H653P
306/308
H1M222L
334/336
H1M223L
430/432
H1M224L
358/360
H1M225L
382/384
H1M234L
454/456
H1M236L
406/408
H1H236L2
468/408
H1H257L
22/24
H1H268L
46/48
—
—
H1H283L
70/72
H1H284L
94/96
H1H285L
118/120
H1H291L
142/144
H1H292L
166/168
H1H295L
190/192
H1H624L
214/216
H1H637L
238/240
H1H638L
262/264
H1H644L
286/288
H1H653L
310/312
Example 3
hANGPTL4 Binding Affinity Determination
Equilibrium dissociation constants (K D values) for antigen binding to selected antibodies that bind amino acid residues 26-148 of human ANGPTL4 fused in-line to mouse IgG2a (hANGPTL4-mFc; SEQ ID NO:480) were determined by surface kinetics using a real-time biosensor surface plasmon resonance assay (BIACORE™ T100). hANGPTL4-mFc was captured with goat anti-mouse IgG polyclonal antibody (GE Healthcare) that was chemically coupled to a BIACORE™ chip through free amino groups. Varying concentrations (ranging from 12.5 nM to 50 nM) of anti-ANGPTL4 antibodies were injected over the captured antigen surface for 90 seconds. Antigen-antibody binding and dissociation were monitored in real time at 25° C. and 37° C. Kinetic analysis was performed to calculate K D and half-life of antigen/antibody complex dissociation. Results are shown in Table 3. A human anti-EGFR antibody was used as a negative control, which showed no binding to the captured hANGPTL4-mFc.
TABLE 3
25° C.
37° C.
Antibody
K D (pM)
t 1/2 (min)
K D (pM)
t 1/2 (min)
H1H257P
201
91
238
63
H1H268P
275
80
389
57
H1H283P
130
119
1360
12
H1H284P
168
162
349
81
H1H285P
92.5
156
194
71
H1H291P
87.6
303
178
122
H1H292P
136
112
167
88
H1H295P
30.7
874
2620
10
H1H624P
1190
7
3710
3
H1H638P
193
85
299
48
H1H644P
111
144
3000
6
H1H653P
411
43
2130
6
For H1H268P and H1H284P, Fab fragments were prepared by papain digestion and purified by standard purification methods, and their binding affinities to hANGPTL4 were measured at 25° C. at pH 7.2 and pH 5.75 using the BIACORE™ system, essentially according to the method described above. Briefly, various concentrations (3.125 nM-100 nM) of anti-hANGPTL4 antibodies (i.e., H1H268 Fab, entire H1H268 mAb, H1H284 Fab, and entire H1H284 mAb) were injected over a low density anti-mFc captured hANGPTL4(26-148)-mFc (−68±4 RU) surface, or the surface of amino-coupled hANGPTL4(26-406)-His (R&D Systems) (450 RU) or amino-coupled cynomolgus monkey N-terminal region (amino acid residues 1-130 of SEQ ID NO:490) expressed with an C-terminal hexa-histidine tag (MfANGPTL4(1-130)-His) (1,028 RU). Kinetic analysis was performed to measure k a and k d , and K D values and half-life of antigen/antibody complex dissociation were calculated. The results are shown in Table 4 (H1H268P) and Table 5 (H1H284P).
TABLE 4
50 mM
Antigen
mAb
Antibody
captured
or Fab
k a
k d
K D
t 1/2
Antigen
H1H268P
pH
(RU)
bound
(M −1 s −1 )
(s −1 )
(pM)
(min)
hANGPTL4
Full mAb
7.2
35 ± 1.9
40
1.53 × 10 5
9.59 × 10 −5
629
120
(26-148)-
5.75
27 ± 0.6
77
6.28 × 10 5
1.38 × 10 −4
220
84
mFc
Fab
7.2
35 ± 1.9
10
3.00 × 10 5
6.01 × 10 −4
2,000
19
5.75
27 ± 0.6
20
1.74 × 10 5
3.04 × 10 −3
17,500
4
hANGPTL4
Full mAb
7.2
Amino-
38
4.89 × 10 5
2.00 × 10 −4
408
58
(26-406)-
5.75
coupled
45
9.23 × 10 5
4.46 × 10 −4
483
26
His
Fab
7.2
450 RU
13
7.26 × 10 5
1.18 × 10 −2
16,300
1
5.75
10
4.44 × 10 5
6.57 × 10 −3
14,800
2
MfANGPTL
Full mAb
7.2
Amino-
279
3.92 × 10 5
4.76 × 10 −5
122
243
4(1-130)-
5.75
coupled
583
1.07 × 10 5
8.24 × 10 −5
77.2
140
His
Fab
7.2
1,028 RU
167
2.67 × 10 5
1.71 × 10 −3
6,420
7
5.75
178
3.12 × 10 5
4.32 × 10 −3
13,800
3
TABLE 5
50 mM
Antigen
mAb
Antibody
captured
or Fab
k a
k d
K D
t 1/2
Antigen
H1H284P
pH
(RU)
bound
(M −1 s −1 )
(s −1 )
(pM)
(min)
hANGPTL4
Full mAb
7.2
35 ± 1.9
99
2.74 × 10 5
5.36 × 10 −5
196
216
(26-148)-
5.75
27 ± 0.6
171
1.09 × 10 6
8.91 × 10 −5
81.9
130
mFc
Fab
7.2
35 ± 1.9
29
2.45 × 10 5
2.02 × 10 −4
823
57
5.75
27 ± 0.6
56
4.72 × 10 5
1.60 × 10 −3
3,400
7
hANGPTL4
Full mAb
7.2
Amino-
77
8.50 × 10 5
8.85 × 10 −5
105
130
(26-406)-
5.75
coupled
101
1.93 × 10 6
2.72 × 10 −4
141
42
His
Fab
7.2
450 RU
32
1.11 × 10 6
3.44 × 10 −4
310
34
5.75
33
1.21 × 10 6
1.73 × 10 −3
1,440
7
MfANGPTL
Full mAb
7.2
Amino-
414
4.67 × 10 5
5.83 × 10 −5
125
198
4(1-130)-
5.75
coupled
804
1.55 × 10 6
8.42 × 10 −5
54.3
137
His
Fab
7.2
1,028 RU
214
3.10 × 10 5
3.13 × 10 −3
10,100
4
5.75
255
7.24 × 10 5
6.19 × 10 −3
8,540
2
Both Fab fragments were capable of binding to all forms of ANGPTL4, albeit with lower affinities than the whole antibody molecules.
Example 4
Anti-hANGPTL4 Antibody Cross-Reactivity Determination
Possible cross-reactivity of the anti-hANGPTL4 antibodies to related proteins, i.e., hANGPTL3, human angiopoietin-like protein 5 (hANGPTL5) and mouse ANGPTL4 (mANGPTL4), was tested for the selected antibodies, i.e., H1H268P and H1H284P, using the BIACORE™ system. Briefly, anti-hANGPTL4 antibodies as well as negative controls, i.e., two monoclonal antibodies (Control a and Control b) that are non-binders to any ANGPTL proteins, were injected at 3.125 μg/mL-50 μg/mL over amine coupled chip surfaces of hANGPTL3-His (R&D Systems, cat #3829-AN) at 5228 RU, hANGPTL4-His (R&D Systems, cat #4487-AN) at 6247 RU, hANGPTL5-His (Abnova Corp., cat #H00253935-P01) at 5265 RU, and mANGPTL4-His [R26-S410 of mANGPTL4 (SEQ ID NO: 478) fused with an AS linker to a C-terminal 6-histidine tag] at 5233 RU, respectively. A polyclonal antibody specific for hANGPTL3 (R&D System, cat #BAF3485) was also tested. The binding of each antibody, expressed as a specific RU value, was determined and the results are shown in Table 6.
TABLE 6
Specific RU
mAb injected
hANGPTL3-His
hANGPTL4-His
hANGPTL5-His
mANGPTL4-His
Buffer
−17
−23
−18
−7
H1H268P
−17
768
−16
−7
H1H284P
−6
1351
−13
18
Control a
−16
−23
−18
−6
Control b
−17
−23
−18
−6
Anti-hANGPTL3
680
−1
−1
2319
H1H268P and H1H284P only bound specifically to hANGPTL4-His and did not bind any of the other related ANGPTL proteins.
Further, the binding affinities of H1H268P and H1H284P for various ANGPTL3 and ANGPTL4 peptides were also determined by BIACORE™ system. Briefly, H1H268P (1348±11 RU) and H1H284P (868±13 RU) were captured over anti-human Fc surface and various concentrations (62.5 nM-500 nM) of the hANGPTL3 and hANGPTL4 peptides were injected. The peptides tested were hANGPTL4 (R34-L66 of SEQ ID NO:476), N-terminally biotinylated hANGPTL4 (R34-L66 of SEQ ID NO:476), hANGPTL3 (R36-I68 of SEQ ID NO:485), and N-terminally biotinylated hANGPTL3 (R36-I68 of SEQ ID NO:485). Kinetic analysis was performed to measure k a and k d , and K D values and half-life of antigen/antibody complex dissociation were calculated. The results are shown in Table 7. NB: No binding under the experimental conditions described.
TABLE 7
Anti-hANGPTL4
Antibody
Peptide
k a (M −1 s −1 )
k d (s −1 )
K D (nM)
t 1/2 (min)
H1H268P
hANGPTL3-Nterm biotin
NB
—
—
—
hANGPTL4-Nterm biotin
4.53 × 10 3
2.94 × 10 −4
64.8
39
hANGPTL3
NB
—
—
—
hANGPTL4
6.49 × 10 3
3.65 × 10 −4
56.3
32
Neither of the antibodies bound to any of the hANGPTL3 peptides. In addition, H1H284P did not bind to any of the hANGPTL4 peptides even at the highest peptide concentration tested (500 nM), while H1H268P was able to bind to both hANGPTL4 peptides. This suggests that H1H268P recognizes a linear epitope within the 34-66 region. In contrast, H1H284P either binds outside this region or does not recognize a linear epitope in this region.
Example 5
Inhibition of hANGPTL4 by Anti-ANGPTL4 Antibodies
Lipoprotein Lipase (LPL) plays a critical role in lipid metabolism in humans. LPL catalyzes hydrolysis of triglycerides and releases fatty acids to be metabolized. ANGPTL4 inhibits LPL activity leading to increased level of lipids (Oike et al., 2005 , Trends in Molecular Medicine 11(10):473-479). The N-terminal coiled-coil region of ANGPTL4 undergoes homo-multimerization, both in isolation and when joined to the C-terminal fibrinogen-like region. The N-terminal region also inhibits LPL when expressed without the C-terminal fibrinogen region. A cell-free bioassay was developed to determine the ability of selected anti-hANGPTL4 antibodies to inhibit ANGPTL4-induced decrease in LPL activity.
Inhibition of hANGPTL4 activity by selected anti-hANGPTL4 antibodies was determined using the CONFLUOLIP™ Continuous Fluorometric Lipase Test (Progen, Germany) using two hANGPTL4 proteins: full-length hANGPTL4 (i.e., amino acid residues 26-406 of SEQ ID NO:476) with a C-terminal hexa-histidine tag (hANGPTL4-His; R&D Systems, MN) and hANGPTL4-mFc (SEQ ID NO:480) containing the N-terminal coiled-coil region.
Briefly, 2 nM bovine LPL, 0.25 μM human ApoCII (a cofactor of LPL), 2 mg/mL BSA and 1.6 mM CaCl 2 , were premixed in a 96-well assay plate. Either hANGPTL4-His or hANGPTL4-mFc protein was added to the Apo/LPL mixture to a final concentration of 10 nM and 2 nM, respectively. The Apo/LPL/ANGPTL4 protein mixtures were then added together with serially diluted anti-hANGPTL4 antibodies with a starting concentration of 300 nM (for inhibition of hANGPTL4-His) or 100 nM (for inhibition of hANGPTL4-mFc) and incubated at room temperature for 30 minutes (final volume 50 μl). Following the incubation, 200 μl of reconstituted lipase substrate, 1-trinitrophenyl-amino-dodecanoyl-2-pyrendecanoyl-3-O-hexadecyl-sn-glycerol (LS-A, Progen), was added to the antibody mixture and incubated at 37° C. for two hours. Fluorescence was then measured at 342 nm/400 nm (excitation/emission) using a FlexStation® 3 Microplate Reader (Molecular Devices, CA). Fluorescence is directly proportional to LPL activity. Results are shown in Table 8. Control I: a rabbit polyclonal antibody specific for hANGPTL4 (BioVendor). Control II: an irrelevant human antibody that does not bind hANGPTL4. NT: not tested. The total inhibition (i.e., 100% inhibition) was determined from the relative fluorescence unit (RFU) of the assay with 2 nM bovine LPL, 0.25 μM human ApoCII, 2 mg/mL BSA and 1.6 mM CaCl 2 , in the absence of anti-ANGPTL4 antibodies and ANGPTL4 proteins.
TABLE 8
% Inhibition of hANGPTL4 Activity
hANGPTL4-mFc
hANGPTL4-His
Antibody
(2 nM)
(10 nM)
H1H236N2
13
19
H1H257P
16
NT
H1H268P
76
80
H1H284P
82
90
H1H285P
28
47
H1H292P
20
53
H1H624P
62
48
H1H653P
55
48
Control I
29
66
Control II
No inhibition
No inhibition
Antibodies H1H284P and H1H268P exhibited the highest inhibition of ANGPTL4's inhibitory activity against LPL among the antibodies tested, including the polyclonal hANGPTL4 antibody control. For antibodies H1H284P and H1H268P, the antibody concentrations required for 50% maximum inhibition (1050) of 2 nM hANGPTL4-mFc were determined to be 0.8 nM and 1.2 nM, respectively. In addition, the antibody concentrations required for 50% maximum inhibition of 10 nM hANGPTL4-His were determined to be 0.5 nM and 0.2 nM, respectively.
Similarly, H1H284P and H1H268P were tested in the LPL bioassay for their ability to inhibit cross-species orthologs: the cynomolgus monkey N-terminal region (amino acid residues 26-148) expressed with an N-terminal hexa-histidine tag (His-MfANGPTL4; SEQ ID NO:488) and the mouse full-length ortholog (amino acid residues 26-410 of SEQ ID NO:478) with a C-terminal hexa-histidine tag (mANGPTL4-His). A full dose-response using the ANGPTL4 protein in the LPL assay was first performed to determine the ANGPTL4 EC50 for each experiment and 1050 determinations for each antibody were then performed using constant concentrations of ANGPTL4 protein, as shown in Table 9. Antibody concentrations ranged from 0 to 100 nM. NB: Not blocking.
TABLE 9
hANGPTL4
hANGPTL4
His-MfANGPTL4
mANGPTL4
(26-406)-His
(26-148)-mFc
(26-148)
(26-410)-His
EC50 (nM)
6.00
0.50
3.89
0.63
Constant ANGPTL4 (nM)
10
2
10
1
IC50
H1H268P
0.46
0.47
0.42
NB
(nM)
H1H284P
0.31
0.51
0.42
NB
IgG1 control
NB
NB
NB
NB
Both antibodies inhibited both human ANGPTL4 (full-length and N-terminal) and monkey ANGPTL4 (N-terminal) protein activity with IC50s of about 0.3-0.5 nM; but neither antibody inhibited mouse ANGPTL4 (full-length) up to the highest antibody concentrations tested (i.e., 100 nM).
Example 6
In Vivo Effect of ANGPTL4 on Plasma Lipid Levels
hANGPTL4 was administered intravenously to C57BL/6 mice to determine the biological effect of hANGPTL4 on plasma lipid levels. Briefly, C57BL/6 mice were put into four groups of five animals and each group was administered with different amount of hANGPTL4-mFc protein (SEQ ID NO:480): 25 μg, 50 μg, 100 μg and 300 μg, per mouse. A control group received injections of PBS. hANGPTL4-mFc protein and PBS were administered by intravenous injection (i.v.) via tail vein. Mice were bled at 15 min, 30 min, 60 min and 120 min after delivery of hANGPTL4-mFc or PBS and plasma lipid levels were determined by ADVIA® 1650 Chemistry System (Siemens). Measurements of triglycerides, total cholesterol, low density lipoprotein (LDL), nonesterified fatty acids (NEFA-C) and high density lipoprotein (HDL) were determined for each dose group. Measurements of total cholesterol, LDL, NEFA-C and HDL were not significantly different across each dose group for each time point post-injection. Injection of 25 μg/mouse of hANGPTL4-mFc increased circulating triglycerides greater than two-fold as compared to control mice (PBS) 30 minutes post injection. Thus, the 25 μg dose of hANGPTL4-mFc was selected as a possible minimum dosage for analysis of inhibition of ANGPTL4-induced increase in serum triglyceride levels by selected anti-hANGPTL4 antibodies as described below.
Example 7
In Vivo Inhibition of ANGPTL4 by Anti-ANGPTL4 Antibodies
In another set of experiments, selected anti-hANGPTL4 antibodies were tested for their ability to inhibit hANGPTL4-induced increase of triglyceride levels. Measurements of total cholesterol, LDL, NEFA-C and HDL were also made. Briefly, C57BL/6 mice were put into groups of five mice each for each antibody tested. Antibodies were administered at 5 mg/kg dose by subcutaneous injection. Control group I, i.e., mice that received neither anti-hANGPTL4 antibodies nor hANGPTL4, were administered with PBS. Twenty-four hours post-injection of antibody, hANGPTL4-mFc (SEQ ID NO:480) was administered (i.v.) at a dose of 25 μg/mouse to each antibody group. Mice were bled at 30 min after hANGPTL4-mFc injection and lipid levels were determined by ADVIA® 1650 Chemistry System (Siemens). Averages were calculated for each of the measurements of triglycerides, total cholesterol (Total-C), LDL, NEFA-C and HDL for each antibody or control group. Levels of circulating anti-hANGPTL4 antibodies (Serum Ab) were also determined using a standard ELISA assay. Briefly, plates were coated with a goat anti-human Fc antibody (Sigma-Aldrich) to capture Serum Ab. Serum was then added to the plates and captured anti-hANGPTL4 antibodies were detected by chemiluminescence using a horseradish peroxidase (HRP) conjugated goat anti-human IgG antibody (Sigma-Aldrich). Results, expressed as (mean±SEM) of serum lipid concentration, are shown in Tables 10-12. Control I: Mice that received PBS, but neither anti-hANGPTL4 antibodies nor hANGPTL4-mFc. Control II: Mice that received a human antibody specific for CD20 (i.e., the mAb having the sequence of 2F2 clone disclosed in US 2008/0260641) and hANGPTL4-mFc.
TABLE 10
Serum
Triglycerides
Total-C
LDL
NEFA-C
HDL
Ab
Antibody
(mg/dL)
(mg/dL)
(mg/dL)
(mg/dL)
(mg/dL)
(μg/mL)
Control I
98.20 ± 5.49
89.80 ± 4.28
5.60 ± 0.66
1.01 ± 0.04
44.18 ± 2.43
—
Control II
211.60 ± 58.29
93.40 ± 5.52
6.30 ± 0.22
1.33 ± 0.17
44.62 ± 3.14
12.76 ± 0.52
H1H284P
99.20 ± 9.52
80.80 ± 6.40
4.98 ± 0.87
0.99 ± 0.11
39.60 ± 3.46
7.96 ± 0.55
H1H257P
115.80 ± 6.43
84.40 ± 3.53
5.30 ± 0.36
0.97 ± 0.03
41.38 ± 3.24
8.43 ± 0.86
TABLE 11
Serum
Triglycerides
Total-C
LDL
NEFA-C
HDL
Ab
Antibody
(mg/dL)
(mg/dL)
(mg/dL)
(mg/dL)
(mg/dL)
(μg/mL)
Control I
66.60 ± 7.94
70.00 ± 2.3
3.88 ± 0.36
0.76 ± 0.08
35.26 ± 1.09
—
Control II
161.00 ± 17.83
73.60 ± 0.93
4.12 ± 0.17
1.18 ± 0.09
35.10 ± 0.6
11.05 ± 2.28
H1H236N2
151.80 ± 9.26
72.40 ± 1.81
4.26 ± 0.25
1.11 ± 0.18
33.78 ± 1.13
9.20 ± 0.63
H1H624P
81.20 ± 9.26
72.80 ± 5.49
4.36 ± 0.92
0.86 ± 0.07
35.40 ± 2.68
11.76 ± 0.89
H1H268P
92.60 ± 11.44
76.00 ± 2.14
4.94 ± 0.51
0.82 ± 0.04
35.94 ± 1.64
8.05 ± 1.06
TABLE 12
Serum
Triglycerides
Total-C
LDL
NEFA-C
HDL
Ab
Antibody
(mg/dL)
(mg/dL)
(mg/dL)
(mg/dL)
(mg/dL)
(μg/mL)
Control I
94.20 ± 10.91
75.00 ± 5.32
3.98 ± 0.25
1.01 ± 0.05
40.46 ± 3.25
—
Control II
179.80 ± 28.06
76.80 ± 3.46
4.38 ± 0.09
1.30 ± 0.13
39.06 ± 2.94
11.59 ± 1.2
H1H291P
111.00 ± 7.51
71.20 ± 3.26
3.84 ± 0.12
1.11 ± 0.04
38.24 ± 2.14
9.46 ± 0.73
H1H283P
113.60 ± 8.74
75.80 ± 1.53
4.62 ± 0.39
1.13 ± 0.05
40.30 ± 0.72
7.85 ± 1.00
H1H295P
104.80 ± 9.44
74.60 ± 4.82
4.04 ± 0.40
1.12 ± 0.04
39.70 ± 3.13
12.61 ± 0.83
H1H653P
88.00 ± 13.52
74.20 ± 4.49
3.84 ± 0.32
1.04 ± 0.1
40.10 ± 2.72
8.77 ± 1.06
H1H285P
91.40 ± 11.99
76.40 ± 1.75
3.72 ± 0.44
0.97 ± 0.06
42.20 ± 0.91
10.49 ± 0.67
H1H292P
85.80 ± 7.00
74.40 ± 2.11
3.96 ± 0.15
1.06 ± 0.06
39.44 ± 1.68
12.61 ± 0.55
H1H638P
102.80 ± 10.75
73.80 ± 2.78
4.14 ± 0.18
1.06 ± 0.05
39.54 ± 1.65
12.20 ± 0.80
After injection of hANGPTL4-mFc (25 μg), most of the anti-hANGPTL4 antibodies tested (shown in Tables 10-12) exhibited significantly reduced levels of serum triglycerides compared to mice treated with irrelevant antibody (control II).
Example 8
Preparation of Anti-ANGPTL4 Antibodies with hIgG4 Isotype
The antibodies H1H268P and H1H284P with hIgG1 isotype were converted to hIgG4 isotype by replacing the respective constant regions with the hIgG4 amino acid sequence of SEQ ID NO:483, which contains a S108P mutation in the hinge region. Furthermore, a single amino acid substitution was introduced in the framework region 1 of H1H268P (SEQ ID NO:42) to form H4H268P2 (SEQ ID NO:487) in the IgG4 version. K D (pM) and t 1/2 values of the IgG4 antibodies, designated as H4H268P2 and H4H284P, respectively, for hANGPTL4-mFc (SEQ ID NO:480) binding were obtained by Biacore at pH7.4 and 25° C., according to the protocol as described in Example 3 above. The results are shown in Table 13 below.
TABLE 13
Antibody
K D (pM)
t 1/2 (min)
H4H268P2
146
195
H4H284P
143
205
H4H268P2 and H4H284P together with the corresponding IgG1 versions, H1H268P and H1H284P, respectively, were tested in the LPL inhibition assay, as described in Example 5 above, to determine 1050 values. The results are shown in Table 14. NB: Not blocking.
TABLE 14
hAngPTL4
hANGPTL4
(26-406)-His
(26-148)-mFc
EC50 (nM)
4.54
0.29
Constant ANGPTL4 (nM)
10
2
IC50
H1H268P
0.20
0.67
(nM)
H1H284P
0.42
0.33
IgG1 control
NB
NB
H4H268P2
1.61
1.85
H4H284P
1.19
1.69
IgG4 control
NB
NB
In this assay, H1H268P and H1H284P showed IC50s ranging from about 0.2-0.7 nM for the full-length and the N-terminal hANGPTL4 proteins, while H4H268P2 and H4H284P showed IC50s ranging from about 1.0-2.0 nM.
Example 9
Pharmacokinetic Study of Anti-ANGPTL4 Antibodies
Pharmacokinetic clearance rates of anti-hANGPTL4 antibodies H4H268P2 and H4H284P were determined in wild-type mice and in transgenic mice expressing human ANGPTL4 [hANGPTL4(+/+) mice]. The strain background for both wild-type and transgenic mice was C57BL6 (75%) and 129Sv (25%). Separate cohorts consisting of 5 mice each of either wild-type or hANGPTL4(+/+) mice received subcutaneously (s.c.) 1 mg/kg of H4H268P2, H4H284P, or an isotype-matched (hIgG4) control with irrelevant specificity. Blood samples were collected at 0 hour, 6 hours, 1 day, 2 days, 3 days, 4 days, 7 days, 10 days, and 15 days, 22 days, and 30 days after the injection. Serum levels of human antibodies were determined by a sandwich ELISA. Briefly, a goat polyclonal anti-human IgG (Fc-specific) capture antibody (Jackson ImmunoResearch, PA) was coated in 96-well plates at a concentration of 1 μg/mL and incubated overnight at 4° C. After the plates were blocked with BSA, serum samples in a six-point serial dilution and reference standards of the respective antibody in a twelve-point serial dilution were added to the plate and incubated for one hour at room temperature. After washing with a suitable washing buffer, captured human antibodies were detected using the same goat polyclonal anti-human IgG (Fc-specific) antibody conjugated with horse radish peroxidase (HRP) (Jackson ImmunoResearch, PA) and developed by standard colorimetric response using tetramethylbenzidine (TMB) substrate, measuring absorbance at 450 nm in a plate reader. Concentrations of human antibodies in serum were determined using the reference standard curve generated for the same sample plate. The results are shown in Table 15 and FIGS. 3A and 3B .
TABLE 15
Mouse
Cmax
AUC
Antibody
Genotype
(μg/mL)
(hr*μg/mL)
H4H268P2
Wild-type
18.4
318
H4H284P
Wild-type
15.7
200
hIgG4 control
Wild-type
14.2
199
H4H268P2
hANGPTL4(+/+)
13.3
37.0
H4H284P
hANGPTL4(+/+)
5.86
7.60
hIgG4 control
hANGPTL4(+/+)
11.6
168
As shown in Table 15, both anti-hANGPTL4 antibodies showed similar clearance rates as the isotype-matched control antibody in wild-type mice, as reflected in the area under the curve (AUC) calculated over the 30-day period of about 318, 200, and 199 (hr*μg/mL), respectively, for H4H268P2, H4H284P, and hIgG4 control (also see FIG. 3A ). In the transgenic mice expressing only human ANGPTL4 [hANGPTL4(+/+)], the clearance rates as reflected in AUCs were faster for both H4H268P2 (37.0 hr*μg/mL) and H4H284P (7.60 hr*μg/mL) compared to clearance rates in wild-type mice (318 and 200 hr*μg/mL, respectively) and compared to the clearance rate of the isotype-matched control antibody in either the hANGPTL4(+/+) mice (168 hr*μg/mL) or the wild-type mice (199 hr*μg/mL) (also see FIG. 3B ). In the hANGPTL4(+/+) mice, the 30-day AUC for H4H284P (7.60 hr*μg/mL) was about 5-fold less than that for H4H268P2 (37.0 hr*μg/mL). Together these results suggest that both anti-hANGPTL4 antibodies exhibit target-mediated clearance in mice expressing human ANGPTL4, and H4H284P exhibits a substantially faster clearance rate than H4H268P2.
Example 10
In Vivo Effect of IgG1 Anti-hANGPTL4 Antibodies on Circulating TG Levels in Humanized ANGPTL4 Mice
The effect of anti-hANGPTL4 antibodies H1H268P and H1H284P on serum TG levels was determined in mice expressing the ANGPTL4 protein containing the human N-terminal coil-coil region (“humanized ANGPTL4 mice”). The humanized ANGPTL4 mouse was made by replacing first three exons of the mouse Angptl4 gene (the N terminal coil-coil region) with the corresponding human N-terminal coil-coil ANGPLT4 sequence in C57BL6/129 (F1H4) embryonic stem cells. After germ line transmission was established, heterozygous mice (ANGPTL4hum/+) were bred together to generate homozygous mice [ANGPTL4hum/hum or hANGPTL4(+/+)] on a C57BL6 background. Humanized ANGPTL4 mice were pre-bled 7 days before (day −7) the experiment and put into groups of six mice each for each antibody tested. Antibodies (H1H268P, H1H284P and isotype-matched (hIgG1) control with no known cross-reactivity to mouse antigens) were administered at 10 mg/kg dose by subcutaneous injection. Mice were bled after 4 hours of fasting at days 1, 4, 7 and 11 after antibody injection; and serum TG levels were determined by ADVIA® 1800 Chemistry System (Siemens). Average TG levels were calculated for each time point for each antibody. Results, expressed as (mean±SEM) of serum TG concentration, are shown in Table 16.
TABLE 16
Days after
Serum TG (mg/dL)
injection
hIgG1 Control
H1H268P
H1H284P
−7
117 ± 18
112 ± 9.3
113 ± 11
1
138 ± 21
129.8 ± 5.6
125 ± 18
4
102 ± 14
73.3 ± 8.9
67 ± 9.8
7
112 ± 10
83 ± 14
91 ± 7.2
11
110 ± 15
76 ± 5.5
109 ± 11
Levels of circulating anti-hANGPTL4 antibodies (“serum human Ab”) were also determined using a standard ELISA assay. Briefly, plates were coated with a goat anti-human Fc antibody (Sigma-Aldrich) to capture serum human Ab. Serum was then added to the plates and captured anti-hANGPTL4 antibodies were detected by chemiluminescence using a horseradish peroxidase (HRP)-conjugated goat anti-human IgG antibody (Sigma-Aldrich). Results, expressed as (mean±SEM) of serum human Ab, are shown in Table 17.
TABLE 17
Days after
Serum Human Antibody (μg/mL)
injection
hIgG1 Control
H1H268P
H1H284P
−7
2.71 ± 2.18
2.92 ± 2.92
3.02 ± 2.38
1
24384 ± 911
24130 ± 1788
16459 ± 1455
4
22553 ± 1811
16557 ± 1369
9103 ± 767
7
13833 ± 467
12586 ± 1176
2428 ± 525
11
13145 ± 1598
6106 ± 1111
135 ± 38
Administration of H1H268P to humanized ANGPTL4 mice led to ˜25-30% reduction in circulating TG 4-11 days after the antibody administration, compared to mice dosed with an isotype-matched control antibody. TG reduction resulting from H1H284P administration was most effective at day 4 after injection of the antibody (˜34% in TG reduction), but by day 11 TG levels were increased back to control level, probably due to fast clearance rate of the antibody.
Example 11
In Vivo Effect of IgG4 Anti-hANGPTL4 Antibodies on Circulating TG Levels in Humanized ANGPTL4 Mice
The effect of anti-hANGPTL4 antibodies, H4H268P2 and H4H284P, on serum TG levels was determined in humanized ANGPTL4 mice. Humanized ANGPTL4 mice were pre-bled 7 days before the experiment and put into groups of six mice each for each antibody tested. Antibodies (H4H268P2, H4H284P and isotype-matched (hIgG4) control with no known cross-reactivity to mouse antigens) were administered at 10 mg/kg dose by subcutaneous injection. Mice were bled after 4 hours of fasting at days 1, 4, 7 and 11 after antibody injection; and TG levels were determined in the serum by ADVIA® 1800 Chemistry System (Siemens). Average TG levels were calculated for each time point for each antibody. Results, expressed as (mean±SEM) of serum TG concentration, are shown in Table 18.
TABLE 18
Days after
Serum TG (mg/dL)
injection
hIgG4 Control
H4H268P2
H4H284P
−7
103 ± 9.5
101 ± 9.3
103 ± 8.0
1
118 ± 13
81 ± 6.8
86 ± 8.6
4
115 ± 9.8
67 ± 5.3
69 ± 6.4
7
81 ± 9.7
56 ± 7.1
71 ± 11
11
109 ± 10
87 ± 8.7
83 ± 7.3
Administration of H4H268P2 and H4H284P to humanized ANGPTL4 mice led to a significant reduction in circulating TG on day 1 (H4H268P2) and day 4 (H4H268P2 and H4H284P) after the antibodies administration, compared to mice dosed with isotype-matched control antibody.
The effect of H4H268P2 on circulating TG levels was further studied in humanized ANGPTL4 mice crossed to ApoE null mice. The ApoE null mouse model is known as a highly atherogenic and hyperlipidemic model with the majority of cholesterol and TG circulating in VLDL particles due to impaired VLDL remnant clearance. Humanized ANGPTL4×ApoE null mice were pre-bled 7 days before the experiment and put into 2 groups of six mice each. Antibodies H4H268P2 and Control Ab were administered at 10 mg/kg by subcutaneous injection. Mice were bled after 4 hours of fasting on days 1, 4, 7, 11 and 17 after antibody injection and TG levels were determined in the serum by ADVIA® 1800 Chemistry System (Siemens). TG reductions shown in FIG. 4 are expressed as a percent of TG levels compared to Control Ab.
TG levels were significantly reduced for all 17 days (more than 42%) with the greatest reduction at day 7 (˜50%) after administration of H4H268P2, compared to mice dosed with Control Ab.
Example 12
In Vivo Effect of Anti-hANGPTL4 Antibodies in Combination with Fenofibrate on Serum TG Levels
The effects of the anti-ANGPTL4 antibody H4H268P2 and TG-reducing drug fenofibrate, each alone or in combination, on serum TG levels were evaluated in humanized ANGPTL4 mice. The mice were pre-bled 7 days before the experiment after 4 hours of fasting and put into 4 groups of six mice each. Groups 2 and 4 were administered with H4H268P2 at 10 mg/kg by subcutaneous injection on day 0 and groups 1 (control group) and 2 were placed on regular chow diet. Groups 3 and 4 received chow diet supplemented with 0.05% (w/w) of fenofibrate (the dosage level was determined experimentally in a pilot study). Serum was collected from a terminal bleed on day 7 after H4H268P2 and/or fenofibrate administration (after 4 hours of fasting) and analyzed by ADVIA® 1800 Chemistry System (Siemens). The results are shown in FIG. 5 .
Administration of H4H268P2 alone and in combination with fenofibrate led to significant reduction in circulating TG levels 7 days after administration. TG levels were reduced by ˜40% (mean) 7 days after H4H268P2 administration alone, ˜25% after fenofibrate treatment alone, and ˜50% after combination treatment of H4H268P2 and fenofibrate, compared to control group treated with chow diet. H4H268P2 showed more efficacy than fenofibrate in reducing circulating TG levels in mouse models. Combination treatment showed a synergistic effect of H4H268P2 and fenofibrate on TG levels. Remarkably, livers collected from mice consumed fenofibrate (groups 3 and 4) for 7 days were significantly enlarged (1.8 times, liver weight/body weight), compared to mice consumed control chow diet (groups 1 and 2) (data not shown).
Example 13
Pilot Study on Pharmacokinetics/Pharmacodynamics of Anti-ANGPTL4 Antibodies in Obese Rhesus Monkeys
Phase I: In a pilot non-GLP pharmacokinetics/pharmacodynamic (PK/PD) study, H4H268P2 and H4H284P were administered as a single bolus intravenous (IV) injection, to obese rhesus monkeys ( Macaca mulatta ). Rhesus monkeys were selected because this species is closely related, both phylogenically and physiologically, to humans and is a species commonly used for nonclinical toxicity evaluations. Obese monkeys that had been on a high fat diet for greater than 6 months were selected because they typically display moderately elevated TG levels (i.e., mean
>100 mg/dL; hyper-TG). Eight confirmed healthy, male monkeys were acclimated and assigned to the study for baseline assessment for 7 days prior to dosing. All animals received a vehicle (10 mM histidine, pH 6) IV infusion on Day −5, after which four of them received H4H268P2 and another four H4H284P at 10 mg/kg IV on day 0. No injection site reactions or other adverse effects were observed at any time point after infusion.
Serum samples were collected from the baseline period through day 35 post-dosing and assessed for serum lipid levels by ADVIA® 1800 Chemistry System (Siemens). The average baseline for each animal was determined based on the samples taken on Days −7, −5 and 0. Preliminary analysis of samples taken after vehicle administration revealed that 3 obese animals from each group displayed elevated fasted TG levels (i.e., TG>100 mg/dL) while one animal from each group had an average TG level well within the normal range (i.e., mean fasting TG level of 42 mg/dL and 84 mg/dL). Thus the data analysis was done with 3 animals in each group. Percent (%) changes of serum TG levels from the baseline were determined for each animal and averaged for each Ab group. The results are shown in FIG. 6 .
Administration of H4H268P2 to the three mildly hyper-TG animals showed a maximal reduction of 57% at day 4 post-dosing. The mean serum TG levels for these animals after H4H268P2 treatment remained at or below 100 mg/dL until approximately Day 25. Moderate effects were observed on additional lipids, such as LDL-cholesterol (LDL-C) and HDL-C; however total-C was unchanged (data not shown). Administration of H4H268P2 to the single obese animal with low TG levels did not yield any significant effect to lower fasting TG's or any other lipid parameters (data not shown), suggesting a lower limit for the reduction of TG levels by the antibody.
Phase II: In the second non-GLP pharmacokinetics/pharmacodynamic (PK/PD) study only H4H268P2 was administered as a single bolus intravenous (IV) injection to eight obese rhesus monkeys ( Macaca mulatta ). The step of pre-dosing vehicle injection was omitted in this study. Three baseline assessments were taken at days −7, −3 and 0 of the study and all eight monkeys received H4H268P2 at 10 mg/kg by IV on day 0, Serum samples were collected from the baseline period through day 35 post-dosing and assessed for serum lipid levels by ADVIA® 1800 Chemistry System (Siemens). Animals were grouped for data analysis according to average baseline TG levels so as to prospectively predict the effect: A. TG<150 mg/dL (n=3); B. 150 mg/dL<TG<500 mg/dL (n=4); and C. TG>1000 mg/dL (n=1).
FIG. 7 shows the TG levels of the three groups expressed as percent changes of TG levels from the average of 3 baseline TG values. As expected on the basis of preclinical data, the greater reduction in fasting TG levels was seen in the animals with higher basal serum TG levels. An especially dramatic and rapid drop in TG level was observed in an individual animal whose baseline TG level was >1000 mg/dL. A robust decrease in TG levels (50-68%) was observed for animals with baseline 150 mg/dL<TG<500 mg/dL. In this group of obese monkeys administration of H4H268P2 increased HDL-C, but had no effect on LDL-C or Total-C (data not shown). Animals with baseline TG<150 mg/dL (normal TG levels) were largely unresponsive to H4H268P2.
|
A fully human antibody or antigen-binding fragment of a human antibody that specifically binds and inhibits human angiopoietin-like protein 4 (hANGPTL4) is provided. The human anti-hANGPTL4 antibodies are useful in treating diseases or disorders associated with ANGPTL4, such as hyperlipidemia, hyperlipoproteinemia and dyslipidemia, including hypertriglyceridemia, hypercholesterolemia, chylomicronemia, and so forth. Furthermore, the anti-hANGPTL4 antibodies can be administered to a subject in need thereof to prevent or treat diseases or disorders, for which abnormal lipid metabolism is a risk factor. Such diseases or disorders include cardiovascular diseases, such as atherosclerosis and coronary artery diseases; acute pancreatitis; nonalcoholic steatohepatitis (NASH); diabetes; obesity; and the like.
| 2
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to, and is a continuation of, U.S. application Ser. No. 11/831,433, filed Jul. 31, 2007, issued as U.S. Pat. No. 8,006,265, which is a continuation of U.S. application Ser. No. 09/584,805, filed May 31, 2000, issued as U.S. Pat. No. 7,269,837, which are all incorporated herein by reference in their entirety for all purposes.
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates generally to the field of interactive television and in particular to a new and useful way to provide selective advertising to a television viewer using an interactive display.
Interactive television systems including advertising are generally known in the art. For example, an interactive television system which queries a viewer about their advertising preferences and then presents targeted advertisements is taught by U.S. Pat. No. 6,006,257. A viewer can select from the option of receiving no advertising and pay a fee to watch a program, some advertising and a reduced fee, or interactive advertising and watch the program for free. The interactive advertising requires responses from the viewer, and the advertising can be changed depending on the responses given by the viewer. A set-top communications box having a cable modem connection is used to connect the television to the program provider and advertiser on the Internet.
U.S. Pat. No. 5,761,606 is for an interactive system which provides indicators to a viewer through the vertical blanking intervals (VBI) of a conventional program. The indicator can be a message on the television screen, a blinking light or a sound, among other things. The indicators provide a notice to viewers that more information about the program is available, sometimes through links to Internet or other on-line information providers. If the link is selected, the system connects to the on-line information provider via a digital connection using address information in the indicator link. The information may be displayed on a television using picture-in-picture format.
U.S. Pat. No. 5,585,858 teaches a system for simulcasting an interactive program with a normal television program using the same video signal bandwidth. Graphical questions can be presented to the viewer at the beginning or during the program. A response is made using a keyboard or keypad. The system generates a reply based on the user response. Users can have either a set-top communications box or a personal computer attached to the television to connect interactive components. The system is particularly adapted to educational uses.
U.S. Pat. No. 5,724,103 discloses an interactive information delivery system using the vertical blanking intervals (VBI) of certain television stations to provide data sent with the conventional programming on a computer monitor. A computer having the necessary decoding hardware can display both the data and the conventional program on the monitor. The data is encoded into the VBI by the television station broadcaster prior to transmission of the conventional program. The patent does not teach displaying the data and conventional program on a television.
U.S. Pat. No. 5,931,908 describes an overlay system for an interactive television program in which overlay items seen on the screen can be selected to activate information retrieval from the Internet. As an example, if an overlay of an actor's name shown in the credits is selected, information about the actor is retrieved from the Internet and displayed to the viewer. Overlays are associated with a particular program so that the available selection options are relevant to the program.
Patents which disclose cable devices for displaying information on a television, include U.S. Pat. No. 5,579,057 for an on-screen display system for a subscriber terminal of a subscription television system. A screen containing a reduced size graphics area (television signal) bordered by a text display is described in columns 10 and 11 . The graphics area can be overlapped by the text mode. The patent relates to addressable television cable converter boxes which can use either the cable connection or a telephone connection to order pay-per-view events and other programming. The patent does not teach receiving a signal from the Internet; the television signals are all received from a cable provider via the cable, or the display information comes from graphics stored in a memory in the converter box.
U.S. Pat. No. 5,524,195 discloses a graphical interface for an on-demand video system having a television, a set-top communications box and a video server. The available user selections are presented as a graphic scene on the television for selection by a user. A CPU in the set-top box generates the graphic scene and interprets user commands. Advertisements are identified as being one of the possible selections presented on the television screen. However, the graphic scene occupies the entire screen, there is no connection to the Internet and television signal programming cannot be viewed concurrently with the graphic scene.
A method of providing directed advertising via a consumer's television is taught by U.S. Pat. No. 5,915,243. First, the consumer is asked a series of questions to determine what advertising is appropriate for the consumer. Then, based on the profile, different promotions and coupons are offered to the consumer through the television. A set-top communications box is connected to the television which is both a signal tuner and transmitter using the cable television lines.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an interactive television advertising method using a set top box to deliver internet-based advertisements.
It is a further object of the invention to provide advertising to a consumer which can be selected to obtain more detailed information about an advertised product or service.
Accordingly, an advertising method provides a way of marketing products and services from an Internet-based computer server on a television set equipped with a communications box connecting the television to the Internet.
A semi-transparent icon is displayed on the television screen by the communications box, preferably in the lower left corner, over the programming from the currently selected channel. The icon periodically changes to resemble different product trademarks or company names. The icon is a link to an advertisement or other product information for the trademark or name. The advertisement can be stored on the communications box in a cache memory or on a disk. Alternatively, the box can be used to retrieve advertising from an Internet server computer when the icon is selected.
The box may receive Internet signals over telephone lines, or, in an alternate embodiment, the Internet signal can be transmitted in the sidebands of television channels, such as PBS. The box may adjust the television signal to display the advertisement from the Internet source as a border around the resized television signal, similar to sports tickers and stock tickers used on television stations like ESPN, CNN, CNBC, among others.
Thus, the method comprises providing a communications box for storing and displaying advertising and interpreting user commands, connecting the box to a television set and to the Internet, and using the box to display an icon on the television screen. The icon is a semi-transparent link superimposed over the television signal programming, that, when selected by sending a user command to the box, causes advertising stored in the box to be displayed on the television. The communications box is updated via the Internet connection, either by the box requesting updates, or an Internet server sending the updates to the box automatically.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a drawing showing the interconnection of components at a subscriber's location;
FIG. 2 is a schematic drawing showing the interconnection of the components of a system used to practice the invention; and
FIG. 3 is a flowchart showing the steps of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The method of the invention delivers advertising from an Internet-based server to multiple subscribers at different, distributed locations through a conventional television using a set top box.
Referring to the drawings, in which like reference numerals are used to refer to the same or similar elements, FIG. 1 shows the equipment used to practice the method at a subscriber's location. A television set 10 is connected to a cable box 20 channel selector and to a set top controller or communications box 30 by standard coaxial cables or other known connections. The set top communications box 30 has a cable connection 34 to the cable TV provider company and a phone connection 36 to the local telephone company. A keyboard 40 or other input device is connected to the set top communications box 30 .
Some televisions do not require a cable box 20 , and so this component may not be present in some installations.
The set top communications box 30 includes a CPU for controlling and processing instructions, a memory and a modem. The memory is used for both long term storage and short term CPU operations, and may include RAM and ROM memory and storage devices such as a magnetic or optical drive. The modem may be a telephone modem or a cable modem. When a cable modem is used, the phone connection 36 is not needed. Signals may be received using the cable connection 34 , such as through the vertical blanking index (VBI) portion of channels or other sideband frequencies on stations like PBS. The CPU receives instructions from the keyboard 40 and produces a TV-compatible output to the cable box 20 for display on the television 10 .
Television 10 has a screen 12 which displays an image depending on the channel selected using the cable box 20 . Recently, many broadcast and cable television stations have begun displaying a semi-transparent logo 14 identifying the station being watched in the lower right corner of the image presented on the screen 12 . The logos 14 typically appear as a white logo with the background determined by the image being displayed, so that the full television image is still displayed.
An advertising icon 50 generated by the set top box 30 is presented to the subscriber in the lower left corner of the screen 12 . The advertising icon 50 indicates an interactive link which can be selected by the subscriber using the input device 40 to retrieve advertising information, as described below.
The subscriber's equipment is connected to a central advertising server 70 through the Internet 60 as shown in FIG. 2 . The set top communications box 30 uses either a dial-up or other phone line connection through the local telephone company 37 , or where available, a cable modem connection through the local cable provider 35 to connect to the Internet 60 . As used herein, the term Internet is intended to encompass any large grouping of distributed computers which can share data, as is presently known, or as may be done in the future under a different name.
The method for providing advertising to multiple subscribers shown in the flowchart of FIG. 3 may be practiced using the equipment described above.
As seen in FIG. 3 , with reference to FIGS. 1 and 2 , first the television is turned on 100 . The set top communications box 30 begins displaying semi-transparent icons 50 one at a time on the television screen. The icons are preferably recognizable logos or trademarks of advertisers. The icons 50 each represent the availability of an advertisement or advertiser information. Following an icon 50 being displayed, the set top box 30 waits for an input from the subscriber through the input device 40 . The input is whether the subscriber using the television has selected the icon or not 130 using the input device 40 . If no input is detected after a fixed period, the icon 50 is changed 120 to a different icon and the new icon is displayed 110 on the TV screen 12 . In a preferred embodiment, the icon 50 changes about every 2 minutes, or 120 seconds.
If an icon 50 is selected by a subscriber, then advertising information is retrieved 140 and displayed 150 , 160 on the TV screen 12 . The set top box 30 contains link information for each icon, matching the displayed icon 50 to related advertising information. The advertising information may be stored in a local memory device of the set top box 30 and retrieved on request 142 . Alternatively, the advertising information may be requested and retrieved 146 from the central advertising server 70 .
In order to maintain a current selection of advertisements in the memory of the set top box 30 , advertising information and associated display icons 50 may be automatically downloaded 144 to the set top box 30 memory devices on a regular basis. For example, the information can be downloaded 144 during the early morning of each day, or once per week or less frequently, depending on the nature of the advertising. The automatic download 144 can occur in a number of different ways, including by having the set top box 30 assigned an Internet address to which the central advertising server 70 transmits when the box 30 has a permanent connection, or by having the set top box 30 make the connection to the server 70 , followed by the server downloading 144 the advertising information after it detects the connection.
In a further embodiment, the icons may be transmitted to and stored in the set top communications box 30 separately from the associated advertising information. In such case, the icons are displayed on the screen, and when an icon is selected, the associated advertising information is requested from the central advertising server 70 and transmitted to the set top box 30 for displaying on the television screen 150 , 160 .
Once the set top box 30 has the advertising information retrieved, the display on the TV can either be changed or reframed 150 to fit the format of the advertising information. If the display will be reframed, the displayed program can be reduced in size and framed in the upper portion of the screen, while the lower portion of the screen is used to display the advertising information 160 . Or, the entire TV screen can be used to display the advertising information 160 in place of the regular programming.
Using the method of the invention, a subscriber can view advertising which he/she would like to see on a selective basis. If particular information is known about the subscriber, such as when the set top box 30 is installed in a resort hotel, targeted advertisements can be provided. For example, at a resort in Florida, icons and advertisements for local restaurants and entertainment facilities may dominate the advertising. At a hotel in New York, the advertisements may focus on Broadway shows, restaurants and transportation services.
The method is particularly well suited for providing targeted advertising to persons staying in hotels, resorts and other rental properties, where the owner of the property subscribes to the advertising method and installs the set top communications boxes 30 . The tenants using the TV's in the rooms then receive the advertising. Discounts can be provided to the tenants who view the advertising, in the form of increased savings at the advertiser's business, or a discount off their rental rate for each advertisement viewed.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
|
A method of providing advertising from a central database server connected to a global computer network to distributed sites via interactive television. A representative icon is presented to a subscriber on a television screen indicating an advertisement. When a the icon is selected, an advertisement information detail is retrieved from storage in a local memory, or from the central database server and presented to the subscriber on the television screen.
| 7
|
BACKGROUND OF THE INVENTION
[0001] The invention relates to improvements in suspended ceiling grid components and, in particular, to end connectors for main runners or tees of such systems.
PRIOR ART
[0002] It is difficult to produce a main tee grid connector with previously known designs that is consistently easy to assemble in the field and that will result in a reliable and positive interconnection. Various known end connectors for main runners or tees can be somewhat difficult to install for numerous reasons. Such connectors may not be self-aligning and if they have provisions for self-alignment, their performance in this regard may be marginal at best. Smooth engagement and coupling between end connectors can be obstructed where the configuration of the connector parts have prominent surfaces or projections that interfere with the advance of mating end connectors.
[0003] Typically, main runners are 12′ long and are installed by a technician who, during an installation, grasps the runner, relative to the end being joined to a preceding runner, on the far side of its center. This permits proper balance and allows the technician to be in a suitable position to initially tie the runner up in suspended position. Thus, the technician is at least 6′ away from the joint so that it is difficult for the technician to clearly see the end receiving pocket of the preceding runner. Moreover, from this location, the technician cannot cup the ends to be joined in one hand to align them together. Consequently, there remains in the art, a need for an end connection or splice system that affords improved self-aligning capability.
[0004] A more subtle but sometimes more troublesome problem occurs when the end connectors are out or nearly out of dimensional tolerance due to variations in material stock, tool wear or other manufacturing conditions. In this circumstance, the forces required to connect the ends of the runners may vary from one runner to the next so that the technician installing the grid is confounded by not knowing for sure if a good connection is being made. Additionally, these dimensionally marginal parts can require excessive assembly force, again to the distraction or frustration of the technician.
SUMMARY OF THE INVENTION
[0005] The invention provides an end connector or “splice” for main runners or tees that has improved self-aligning properties and that provides greater consistency and comparatively lower levels in the force required to complete a connection. The connector of the invention includes an end tab that is configured to align itself with an identical opposing connector to which it is being joined. The connector further includes a resilient pocket receiving area for the end tab of the opposing connector that avoids both high assembly force levels and widely varying assembly force levels in the installation of one runner to the next.
[0006] In the illustrated embodiment, the end tab has elements for aligning itself to the receiving pocket of an opposed connector in both the vertical and horizontal directions. The vertical alignment feature is advantageously effective from a condition where the end tab misalignment is physically limited by the flange of the opposed tee runner. This structure enables a connection to be made where the end tab is first laid on the flange of the opposing previously installed runner and then is simply subjected to an endwise force by the installer. The leading profile of the end tab is effective, in the vertical location established by the flange of the opposed tee, to cam the end tab towards alignment with the mating connector. The vertical self-aligning character of the end tab is augmented by a lock lance element that registers with a groove in an opposed connector end tab. The vertical alignment action of the lock lance is assisted by horizontal alignment elements of the connector. The horizontal alignment elements of the connector comprise a lead angle formed by bending the forward portion of the end tab out of the plane of a main portion of the end tab and an outwardly flared entrance to the end tab receiving pocket. These lead angle and flared entrance elements provide relatively large, smooth camming surfaces, as compared to edge areas, that improve the smooth functioning of the connector. The lead angle of the end tab and outward flare of the opposed connector are readily inter-engaged for horizontal alignment. Additionally, these lead angle and outward flare components avoid any direct edge-to-surface contact between these components so that smooth sliding action occurs when the lock lance moves out of the relief groove of the opposed connector in the late stages of the assembly movement where the potential interference between the connectors is greatest.
[0007] The disclosed connector is arranged to produce an audible click when a connection is completed and, therefore, signal the same to the installer technician. The repeatability and loudness of the click is the result of several structural elements of the connector. The lock lance has a locking edge configured to cause it to snap over a mating edge of the opposed connector without interference with the locking edge of the opposing connector. The resilient character of the receiving pocket of the opposed connector imparts kinetic energy to the end tab when its lock lance snaps over the locking edge of the opposed connector. The end tab, additionally, has stiffening ribs which increase the sharpness of the click made by the snap-over of the lock lance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a perspective view of end portions of two main runners or tees shown prior to their endwise assembly or connection;
[0009] [0009]FIG. 2 is a side elevation of an end portion of a main runner or tee and an associated connector;
[0010] [0010]FIG. 3 is a fragmentary cross-sectional view of the connector area taken along the line 3 - 3 in FIG. 2;
[0011] [0011]FIG. 4 is a cross-sectional view of the end tab taken along the line 4 - 4 in FIG. 2;
[0012] [0012]FIG. 5 is a fragmentary cross-sectional view of the end tab taken along the line 5 - 5 in FIG. 2;
[0013] [0013]FIG. 6 is a side elevational view of an opposed pair of connectors prior to their connection;
[0014] FIGS. 6 A- 6 D show progressive stages of assembly of the opposed connectors and horizontal alignment thereof as viewed from the top of the connectors;
[0015] [0015]FIG. 7 is a side elevational view of the connectors in their assembled state; and
[0016] [0016]FIG. 8 is a side elevational view of a pair of connectors in a self-aligning condition both in the vertical direction and in the horizontal direction, the latter corresponding to a stage between that shown in FIGS. 6A and 6B.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] Referring now to the drawings, there is shown an end portion of a main runner or tee 10 of a general type commonly used for suspended ceiling grid systems as known in the art. Typically, such main runners or tees 10 are combined with cross runners or tees (not shown) to create a suspended grid work. In the illustrated example, the main tee 10 is made of two formed metal strips 12 , 13 typically of steel, although other material such as aluminum can be used. One of the strips 12 forms an upper hollow bulb 14 , a double wall web 16 , and oppositely extending flanges 17 all integral with one another. The strip 12 can have, for example, a thickness of 0.012″ to 0.027″ depending on the application. The other strip 13 lies under the flanges 17 and is wrapped around the distal edges of the flanges 17 to lock the strip 12 in its tee shape, conceal the seam between the flanges 17 and provide a smooth appearance for a lower face 18 of the tee 10 ; the lower face 18 of the strip 13 typically is painted for appearance purposes. The lower strip 13 is a suitable material, typically steel, but can be other materials such as aluminum. Holes 19 through the web 16 enable the tee 10 to be suspended by wire or other means as is known in the art. It will be understood that the runner 10 can have various other shapes, besides a conventional tee shape as is known in the art.
[0018] The runner or tee 10 has an end connector or splice 20 that, in the illustrated case, is integral with the web 16 . It will be understood that certain features of the invention can be applied to connectors that are formed in a single web wall or layer or are formed wholly or partially as separate elements that are joined to the main parts of a runner with rivets or other means as is known in the art. As is conventional, a runner or tee 10 will have a connector 20 at each end.
[0019] The connector 20 includes an end tab 21 and an end tab receiving pocket 22 that, as explained below, cooperate with an identical connector in the manner of a “handshake” to connect the opposed ends of two aligned tees or runners 10 together. The end tab 21 and pocket 22 are die cut and formed by suitable stamping dies. The end tab 21 projects from an imaginary vertical plane perpendicular to the lengthwise direction of the tee 10 and located where the lower face 18 terminates, this location being the nominal end of the tee proper. Major or “land” portions of the end tab 21 are planar and are offset from the plane of the center of the tee 10 (where the walls of the web 16 abut) by a distance at least equal to the thickness of the stock forming the walls of the web (i.e. the thickness of one web wall). As will be understood, this will allow a face of an end tab 21 to mate with the face of another end tab substantially at the mid-plane of each of the tees 10 being joined or connected.
[0020] The side profile of the end tab 21 is generally rectangular having two parallel horizontal edges 23 , 24 at the top and bottom, respectively. A plane of an end portion or lead angle 26 is at an acute angle of about 35°, for example, from the plane of the end tab proper to the side of the tee 10 from which the end tab is offset.
[0021] A lock lance 27 is stamped into a forward area of the end tab 21 at mid-height of the end tab. The lock lance 27 projects from the plane of the end tab proper to the same side to which the lead angle end portion 26 is bent and from which the end tab is offset. The lock lance 27 is bulbous and preferably has the general shape of a longitudinal half of a bullet. A locking edge 28 of the lance 27 is originally cut by a stamping die from a line common to an end edge 29 of a relief and alignment groove 31 . The lock lance edge 28 is originally cut in the plane of the end tab proper on a line that is curved on a radius or radii centered away from the main tee proper, i.e. this cut line is convex with reference from the main tee proper. The result of this curved cut line geometry, when the lock lance is caused to protrude from the plane of the end tab proper, is that the free locking edge 28 forms an angle when viewed in a vertical direction as in FIG. 3 that is about 90° or less. Thus, the apex or mid-point of the edge 28 furthest from the plane of the end tab proper is, ideally, situated at least as far back from a front edge 32 of the end tab 21 as remaining parts of this edge 28 .
[0022] The relief groove 31 is vertically aligned with the lock lance 27 and extends longitudinally rearwardly from the lock lance to a somewhat rounded end 33 adjacent the receiving pocket 22 . The relief groove 31 has a depth about equal or more than the height of the lock lance 27 and a width moderately larger than that of the lock lance.
[0023] A pair of beads or small ribs 34 extending longitudinally from a bend line 36 between the lead angle end portion 26 and end tab proper are stamped into the material of the end tab and project to a side of the end tab opposite that of the lock lance 27 . The beads 34 are parallel to the edges 23 , 24 and extend rearwardly somewhat beyond the lock lance 27 and thereby stiffen the end tab 21 across a weakened line existing where it is cut to form the lock lance edge 28 and groove end edge 29 .
[0024] The tab receiving pocket 22 comprises a wall 37 and an opening 38 . In the illustrated case, the wall 37 and opening 38 are rectangular and are produced by lancing or cutting the stock of the web 16 along parallel horizontal lines or cuts 39 and a vertical line or cut 42 . The pocket wall 37 is integral with the web 16 along a side 43 proximal to the web 16 while the remainder including a distal edge 44 and top and bottom edges 46 , 47 are cut free of the web. With particular reference to FIG. 3, the wall 37 is stamped into a non-planar configuration that, for the most part, is spaced laterally outward of the web 16 . In this context, the plane of the web 16 is defined as the space occupied by the web proper. A region of the wall 37 proximal to the web 16 forms a hollow by virtue of a step portion 48 bent away from the plane of the web 16 and an intermediate portion 49 bent slightly back toward the plane of the web. The distal end of the pocket wall 37 is formed with an outwardly flared portion 51 at an angle to the plane of the web 16 . The wall 37 , when viewed in FIG. 3 is re-entrant at the zone of a bend line 52 between the outwardly flared portion 51 and intermediate portion 49 so that this zone 52 is exclusive in its proximity to the plane of the web 16 as compared to adjacent parts of the wall 37 .
[0025] The connector 20 is adapted to mate with an identical connector as shown in FIGS. 6 A- 6 D and FIG. 7. In this manner, successive main tees or runners 10 are joined together end-to-end to span a room or other space in which a suspended ceiling is to be constructed. An important feature of the connector 20 is its ability to self-align itself to a mating connector. By way of example, FIG. 8 shows a condition where two connectors 20 are being joined together and are initially out of vertical alignment. In the condition of FIG. 8, the connector 20 of one tee 10 is resting on the upper side of a flange 17 of another tee. This condition most typically would be where the higher tee (on the left in FIG. 8) has previously been installed and the lower tee (on the right) is being joined to the previously installed tee. Inspection of FIG. 8 reveals that a lower inclined, curved part 60 of the lead edge 32 has a portion slightly higher than the lower edge of the pocket opening 41 of the opposed connector. Similarly, but not shown, on the opposite side of the tees in FIG. 8, an upper inclined, curved part 61 of the lead edge of the relevant end tab has a portion below the upper opening edge 39 of the connector 20 . With the connector 20 urged horizontally or laterally towards the opposite connector, the lead angle end portion 26 slips into the pocket opening 38 of the opposed connector. Longitudinal force applied to the tee 10 being installed causes the inclined edge 60 working against the pocket opening edge 41 of the opposed connector to cam the connector 20 upwardly relative to the opposed connector and thereby self-aligns the connector to the opposed connector. Other shapes for the rounded edge parts 60 , 61 capable of shifting the connector up or down when engaging the pocket structure are contemplated. This camming action is augmented by two other camming functions. Cam-like inter-engagement between the lead angle end portion 26 and the outwardly flared portion 51 of the pocket wall 37 , at each set of these elements, biases the connectors 20 laterally or horizontally towards one another when the tees are forced axially or longitudinally towards one another. When the lock lances 27 inter-engage with the opposed relief grooves 31 , these elements, in response to the lateral or horizontal bias developed by the sets of lead angle end portion 26 and pocket wall flare portion 51 cam the connectors 20 vertically, again in self-alignment action. The result of these combined camming actions is that the connectors 20 are positively self-aligning and are comparatively easy to interconnect.
[0026] The relief groove 31 avoids significant interference between the connectors due to the projection of the lock lance 27 until after they have been effectively aligned by the end tabs 21 being substantially received in opposed pocket holes or openings 38 . When the lock lances 27 reach the end 33 of the respective relief grooves 31 of their opposed connector 20 continued advance of the tee being installed requires the pocket walls 37 to momentarily resiliently deflect laterally outwardly to allow the lock lances to slide out of the ends of the grooves and over a short distance on the surface of the end tab proper until it passes the cut or edge 42 formed when the pocket wall 37 was made. The reentrant character of the wall 37 allows the surface area of the bend line 52 to exclusively contact the opposing end tab 21 (between FIGS. 6C and 6D) and assures consistent spring action. At this point, the lock lances 27 , under the influence of the spring-like force developed by the deflected resilient pocket walls 37 snap longitudinally behind the edges 42 of the opposed connector thereby completing a connection or splice.
[0027] A beneficial result of the disclosed structural features of the connector is that an audible click is produced when the lock lance edges 28 pass over the edges 42 of the pocket openings 38 allowing the end tabs 21 to snap against one another. The click signals the installing technician that a connection has been completed. The loudness of this click is due in part to the geometry of the lock lance edge 28 which is, as discussed, 90° or less, thereby avoiding a condition where if this edge were in a plane greater than 90°, it would slide down the opposed locking edge 42 and mute the click. The beads 34 , by stiffening the end tabs 21 in the area of the lock lances 27 add to the loudness of the click.
[0028] The lead angle end portions 26 and the flared portions 51 of the pocket walls ensure that only surface-to-surface contact occurs when the greatest interference arises in the connection sequence as the lock lances slide over the land areas between the relief grooves 31 and the locking edges 42 of the openings 38 . Contact between the front edge 32 of an end tab 21 or the distal edge 44 of the pocket wall 37 could greatly increase the frictional resistance between the connectors. In part, the re-entrant character of the wall at the bend line 52 avoids such edge contact. With the periphery of the pocket wall, specifically the edges 44 , 46 and 47 (apart from where it is joined with the web proper), being free of connection with other parts of the connector, the pocket wall acts as a resilient spring. Consequently, the force to deflect it laterally for passage of the lock lance out of a groove 31 and over the adjacent land to the opening edge 42 is limited. In turn, the force to effectuate a connection is moderate and not prone to vary widely when the connectors 20 are nearly out of tolerance because of material thickness variation, tool wear or other manufacturing conditions. Such wide variation is known to occur in prior art connector designs and is found to be very objectionable to professional installation technicians. The beads 34 , in addition to reinforcing the end tab 21 and improving the audible click, serve to avoid excessive friction during a connection where burrs may exist on edges of adjacent parts.
[0029] It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.
|
A connector for a main tee of a suspended ceiling grid that has improved self-aligning and connection force properties. The connector has an end tab with a forward portion bent at a lead angle and a receiving pocket with an outwardly flared entrance that, with an opposed identical connector, cooperate to provide smooth horizontal alignment. The end portion, additionally, includes an edge profile that vertically aligns itself with the receiving pocket of the opposed connector. The receiving pocket includes a spring-like resilient wall that limits the assembly force to overcome interference with projecting lock lances even when the connectors are nearly out of dimensional tolerance. The spring-like pocket wall, shape of the lock lance, and reinforcing beads contribute to an improved audible click signaling that a connection has been completed. The lock lance works with a relief groove to augment self-alignment of the connectors.
| 4
|
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for recording graphic or image information by means of punctiform recording spots that are arranged line-by-line according to a recording grid, or multi-lined within a matrix, and the recording effected step by step, with a recording frequency corresponding to the point intervals or pitch of the grid or matrix, and in which at the beginning of a contour proceeding obliquely to the recording direction the first recording spot is displaced in the direction of the contour by at least a fractional pitch step when its edge does not coincide with the contour, and recording the following recording spots step-by-step in the pulse of the recording frequency.
Recording methods are known in which the image or graphic characters are recorded by the formation of covered surfaces arranged in a grid, for example mosaic printers, which operate with needles, thermographic or electric recording combs. Ink jet printers with individual jets or jets arranged in a matrix, which generate punctiform recording spots, operate along the same principle. The individual recording spots are recorded in correspondence with the grid which is dependent upon the recording frequency. In all of these cases, contours running diagonally to the recording direction are reproduced with poor quality, i.e. present a more or less stepped formation. An example of a general system of the type involved, and of stepped configurations is illustrated in German Offenlegungsschrift No. 2,639,856. This could of course be improved by a finer resolution, i.e. increasing the scanning and recording frequency or, effecting a refinement of the scanning and recording grid. This, however, will be associated with a greater cost and, if the recording apparatus will not permit a higher point frequency, with an impairment of the recording. In some of the aforementioned recording methods, this is only possible to a certain degree, as it is not possible to reduce the point size in the recording as greatly as would be desired.
A method as heretofore been proposed for effecting an improvement in the contour without increasing the fineness of the scanning or the scanning frequency. However, this improvement is effected on the first or leading edge occurring in the recording direction but not on the trailing edge. This method has been termed the "fractional step method" and makes it possible, with the same recording frequency, to displace the first point on an edge by a fractional pitch of the screen line distance in the direction of the contour. The subsequently following points are then written with the normal recording frequency which, however, result in the contour being reproduced at its trailing edge in the original stepped formation, i.e. the improvement thus occurred only along the leading edge of the contour.
BRIEF SUMMARY OF THE INVENTION
The present invention therefore has its objective to provide a method and apparatus for effecting an improvement in the fractional step method by means of which the recording at the trailing edge of a contour is also improved.
This is achieved in the present invention by displacing the first recording spot, at the beginning of the contour proceeding obliquely to the recording direction, in the direction of the contour by at least a fractional pitch when its edge does not coincide with the contour, as in the known method above referred to, with the subsequently following recording spots being recorded step-by-step in the pulse of the recording frequency until the last recording step, which is then displaced in the direction of the contour an additional amount, thereby reducing the stepped effect and providing an improvement in the edge of such a contour.
Apparatus for practicing the method is also provided. In the exemplary embodiment illustrated, the information to be recorded, in quantized form and its length determined in terms of multiplies of the point interval or pitch utlizing a pulse frequency which is a multiple of the recording or step frequency and thus represents a predetermined fraction of the pitch interval. In the event the video segment is not an even multiple of the pitch interval, the control signal is formed which controls the formation of the final output signal.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings wherein like reference characters indicate like or corresponding parts:
FIG. 1 represents a point arrangement of a obliquely proceeding black line, with the application of the usual fractional pitch method;
FIG. 2 illustrates a point arrangement of a corresponding obliquely proceeding black line with the application of the present invention thereto for improving the trailing edge thereof;
FIG. 3 is a point arrangement corresponding to FIG. 2 but in which an overlapping of spots has been employed;
FIG. 4 is a similar point arrangement illustrating the application of the quarter pitch method thereto;
FIG. 5 is a point arrangement according to FIG. 4, in which additional improvement of the trailing edge is effected in accordance with the invention;
FIG. 6 illustrates a point arrangement according to FIG. 5, in which an overlapping of the recording points is employed;
FIG. 7 illustrates various line widths, utilizing a half pitch step, in the fractional pitch method in accordance with the invention;
FIG. 8 is a similar illustration of various line widths utilizing the invention with the fractional pitch method utilizing a one-third pitch step;
FIG. 9 is an illustration of various line widths utilizing the fractional pitch method with a one quarter pitch step;
FIG. 9a illustrates a variation of FIG. 9;
FIG. 10 is a block diagram of the invention;
FIG. 11 is a block diagram for a scanning installation;
FIG. 12 represents schematically an exemplary electronic circuit for the invention; and
FIG. 13, consisting of a-i, illustrates pulse diagrams for the circuit of FIG. 12.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings and more particularly to FIG. 1, there is illustrated therein a portion of a contour which is defined by means of lines I and II, which contour comprises the recording points 1 through 11. Lines n, n+1, and n+2 are illustrated in vertical direction, and respective half pitch steps of the grid points are illustrated in horizontal direction. It will be apparent that in line n+1, in which the half pitch method has been employed, the contour proceeding along the boundary or edge line I has been accurately and cleanly depicted. However, it will be noted that at the end of such line the edge-defining line II has been crossed and a "hole" has resulted between the preceding line, which produces a stepped formation of the contour.
FIG. 2 generally illustrates the sample example. However, in line n+1, the last grid point is displaced by a half pitch step in the direction of the contour, i.e. to the right as viewed in FIG. 2, which, in contrast to the usual recording method, does not involve an increased scanning frequency. As hereinafter subsequently explained, this displacement of the grid point is relatively easy to achieve, by effecting a retarding of the recording thereof sufficient to displace the recording spot by a half pitch step during the recording operation. While there still remains small gaps along the boundary line II between the lines n and n+1, as well as between the n+1 and n+2, these will normally be suppressed in the usual recording operation in which a very strong or large overlapping of grid points are utilized. Such overlapping is disclosed, for example in German Offenlegungsschrift No. 2,616,397. This result is illustrated in FIG. 3 and it will be clearly apparent that a more gap-free contour edge is also achieved at the boundary line II.
FIG. 4 illustrates an example of a contour such as illustrated in FIG. 1, likewise defined by the border or edge defining lines I and II, in which the known quarter pitch method is utilized and, as will be apparent, the contour at line I is better reproduced but there is still a gap present in line n+1 of the contour at the edge defining line II.
FIG. 5 also illustrates the use of the quarter pitch method in conjunction with the present invention, in which a stepped configuration at the trailing edge is avoided, and, in addition, the three recording spots are distributed on the quarter pitch steps available in the line to provide a uniform distribution or spot spacing along the line n+1. The contour is thus optimally reproduced along both the edge line I as well as the edge line II.
FIG. 6 depicts the embodiment of FIG. 5, utilizing the additional overlapping of the grid points or recording spots. As will be apparent the individual recording spots almost completely disappear, so that a nearly ideal representation is achieved of the contour defined by the lines I and II. If a larger overlapping is utilized, the intermediate spaces will disappear entirely.
FIG. 7, illustrates, in chart form, the formation of line widths involving a larger number of grid points, illustrating the application of the invention to the half pitch method. Where the line lengths involve even multiples of full pitch steps, the grid points connect closely to one another, and only in the case where a line length involves a half pitch step, does a gap arise by reason of the retardation of the recording of the last grid point. However, it will be apparent that with suitable overlapping, such gap presents no problem as has been noted from the arrangement in FIG. 6.
FIG. 8 illustrates the basic format utilizing one-third pitch steps. In this arrangement, it will be noted that where five or eight pitch steps are involved, alternative formations are possible. Thus, in the case of five 1/3 pitch steps, one grid point or two grid points may be employed, while in the case of eight 1/3 pitch steps, three grid points may be utilized instead of one.
It will be appreciated that the number of variations in the individual transitions become greater as the number of fractional pitch steps increases, as will be apparent from reference to FIG. 9, illustrating the use of 1/4 pitch steps. Thus, in the case of seven 1/4 pitch steps, two possibilities again arise of utilizing of either two or three grid points. Likewise, in the case of eleven 1/4 pitch steps, a choice is presented of utilizing either two or three grid points, and similarly in the case of fifteen 1/4 pitch steps, three or four grid points may be employed. This law of formation proceeds according to a specific plurality of fractional pitch steps, in the last example, all four fractional pitch steps. Which solution is employed is to a large extent dependent upon whether a large or a small overlapping is utilized. In most instances, where overlapping is involved, it will be desirable to employ the lower number of grid points.
FIG. 9a illustrates an example similar to FIG. 9, again utilizing a 1/4 pitch steps in which a distribution may be effected of the gaps in the interior of the graphic line to be written. For example, beginning with the fourteenth and fifteenth pitch steps as well as the eighteenth and nineteenth steps, the gap may be distributed between several pairs of recording spots.
FIG. 10 illustrates in block form the basic design of a circuit which is suitable for the practice of the invention. It comprises a data source, which repesents a scanning system that is described in greater detail in FIG. 11, a digitalizer, and a data sink.
FIG. 11 schematically illustrates an arrangement for scanning the original from which the recording is to be made. It comprises a light source 1, and an optical system 2, by means of which the light source is focused on a schematically illustrated original 3. The light reflected therefrom is supplied over a collector lens 4, and an aperture 5 to an optoelectric transducer 6, whose output signal is supplied, over an amplifier 7, to a comparator 8, which converts the signal delivered from the optoelectric transducer into a video signal V, which is temporally analog and quantized black/white in its amplitude. This signal is illustrated in line b of FIG. 13.
As illustrated in FIG. 12, the input signal V is supplied to the D-input of a D-flip-flop 9 and to one input of an AND-gate 10. The output of a pulse generator 11, having a pulse frequency corresponding to a one-half pitch step, has its output connected to the T input of the flip-flop 9 and to the second input of the gate 10, the output of which is connected to the trigger input of a monostable flip-flop 12. The Q output of the flip-flop 9 is supplied to one input of an AND-gate 13, the output of which is supplied to the trigger input of a second monostable flip-flop 14.
The Q output of the monostable flip-flop 12 is supplied to the second input of the gate 13 and to the input IN of a shift register 15, the T input of which is supplied with pulses from the generator 11.
The outputs 03 and 02, respectively representing a retarding of the input signal by three or two pulse steps, are supplied to respective inputs of AND gates 16 and 17, each of which has a second input connected to the output of the gate 13, with the Q output of the flip-flop 14 being supplied to a third input of the gate 17 and the Q output of the flip-flop supplied to a third input of the gate 16. The output of the respective gates 16 and 17 are supplied to an output D over a suitable OR-gate 18.
In operation, the video input signal V is temporarily quantized in the flip-flop 9 by means of the pulses of the pulse generator 11, so that a video signal A (line c, FIG. 13) is produced at the output Q and Q of the flip-flop. The first of the video pulses A has an exact length of five and one-half full pitch steps (two half-steps or pulses of the pulse generator 11), so that without employment of the invention, the problem of a stepping of the trailing edge would occur. In the case of the second pulse thereof, the length of the pulse is exactly a whole multiple, i.e. four full pitch steps. In accordance with the invention, this is also reproduced as four full pitch steps. Upon coincidence between the video signal V (line b) and the pulse of the pulse generator 11 (line a) an output pulse signal will appear at the output of the gate 10, causing the monostable flip-flop 12 to trigger. The monostable flip-flop 12 is so adjusted that its duration in flipped state is somewhat smaller than an entire full pitch step, so that the output signal will correspond to the form illustrated in line d of FIG. 13.
When the signal at the output of the flip-flop 9 (line c) is not an even multiple of a full pitch step, a control signal will appear at the output of gate 13 (line g of FIG. 13) which signal is applied to the trigger input of the flip-flop 14 and to respective inputs of gates 16 and 17.
The output of the monostable flip-flop 12 is additionally applied to a input of a shift register 15, by means of which, in conjunction with the pulses supplied thereto by the pulse generator 11 (line a), a retarding is effected of two half pitch steps or three half pitch steps which respectively appear at the output 02 and 03, such retarded signals are respectively illustrated in lines e and f of FIG. 13. These two signals being selectively supplied over the gates 16 and 17 and OR-gate 18, to the output D, whose signal is illustrated in line i of FIG. 13. The output pulse of gate 13 illustrated in FIG. 13g is prolonged by means of the monostable flip-flop 14 for a duration of about four half pitch steps, i.e. four pulse periods, as will be apparent from a reference to line h of FIG. 13.
The output signals of gate 13 and the flip-flop 14 control the change over of the retarded signals supplied by the shift register 15 (lines e and f) to the output D. When the signal illustrated in line h of FIG. 13 is equal to a logic zero, the signal is supplied to the output D in accordance with line f of FIG. 13 and likewise, when such signal is equal to a logic one, the signal is supplied to the output D in accordance with line e of FIG. 13.
However, it is also possible that the output signal of gate 13 is a logic zero, in which event neither of the signals of lines e or f are supplied to the output D, but instead a logic zero exists thereat.
As a result, video signals with a length consist of exact multiples of full pitch steps arrive at the output retarded by three half-pitch steps or periods. However, in the event the video signal length, as illustrated in Example 13, does not amount to an exact multiple of a full-pitch step, an interval of a half full-pitch step is produced between the last full-pitch step recorded and the next full-pitch step. In the example, the total length of such video signal at output D likewise amounts to five and one half full-pitch steps as in the video signal depicted on line c of FIG. 13. As a result the last full pitch step of such video signal corresponds to the signal depicted on line i of FIG. 13, i.e. it thereby conforms to the trailing edge of the contour being reproduced. It will be appreciated that the invention is not limited to the use of one half or one quarter pitch step, but that the full pitch step can be subdivided as finely as desired. Thus, the finer the subdivision, the more precisely the recording spots can be placed on the contours, whereby the cost outlay is dependent upon the quality required, i.e. determined by the fineness of the subdivision to be utilized.
Although I have described my invention by reference to particular illustrative embodiments, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. I therefore intend to include within the patent warranted hereon all such changes and modifications as may reasonably and properly be included within the scope of my contribution to the art.
|
A method and apparatus for recording graphic or image information by means of punctiform recording spots which are arranged line-by-line according to a recording grid, or multi-lined within a matrix, whereby at the beginning of a contour proceeding obliquely to the recording direction, the first recording spot is displaced in the direction of the contour when its edge does not coincide with the contour and, in order to improve the end edge of such a contour proceeding obliquely to the recording direction, the recording of the last recording spot may be additionally displaced relative to the preceding recording spot by a retarding in time of the recording of said last spot.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Patent Application No. 2003-4131, filed Jan. 21, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, in general, to a door control device for refrigerators, and a refrigerator with such a device. More particularly, the present invention relates to a door control device for refrigerators which controls the open angle of a refrigerator door as a user desires, maintains the selected open angle of the door, and dampens a door closing action to retard the energy generated from the door closure. The present invention also relates to a refrigerator having such a door control device.
2. Description of the Related Art
As is well known to those skilled in the art, refrigerators are domestic appliances which keep food and drink cool, for a desired lengthy period of time, while maintaining the freshness of the food and drink. A refrigerator typically comprises a freezer compartment and a refrigerator compartment, with a door provided on each compartment to close the compartment.
Refrigerators are typically arranged side by side with other kitchen furniture or appliances, such as a kitchen sink or a microwave oven. A large-sized refrigerator may be installed in a specified recess formed in a kitchen wall. Due to such an arrangement of the refrigerators, there sometimes occurs interference between the doors of a refrigerator and neighboring furniture, appliances, or the kitchen wall. As a result, the refrigerator doors are easily damaged and are inconvenient for users while opening or closing the doors.
In an effort to solve such problems, the inventors of the present invention proposed a door control device for allowing a user to control the maximum open angles of refrigerator doors, as disclosed in Korean Patent Application No. 2002-53288. However, the conventional door control device is problematic in that a user is forced to loosen and tighten bolts to adjust the maximum open angles of refrigerator doors, making the device inconvenient for the users. In addition, the device only allows a user to adjust the maximum open angles of refrigerator doors, so it is difficult to control the open angles of the refrigerator doors as users desire, or to maintain the selected open angles of the refrigerator doors.
SUMMARY OF THE INVENTION
Accordingly, it is an aspect of the present invention to provide a door control device for refrigerators, which controls the open angle of a refrigerator door as a user desires, maintains the selected open angle of the door, and dampens a door closing action to retard the energy generated from the door closure. It is another aspect of the present invention to provide a refrigerator having the door control device.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
The foregoing and/or other aspects of the present invention are achieved by providing a door control device for a refrigerator having a refrigerator door, including a movable body coupled to the refrigerator door, wherein the movable body is arranged to move in opposite directions in accordance with opening and closing actions of the refrigerator door, and a control unit controlling an opposite directional movement of the movable body in a multi-stage manner.
Also, a guide element contains the movable body, in order to guide the opposite directional movement of the movable body.
Also, a link bar is hinged at a first end thereof to an end of the movable body, and is connected at a second end thereof to the refrigerator door.
Also, the link bar is hinged to the refrigerator door.
Also, the movable body is provided with a plurality of grooves formed along a longitudinal side surface thereof.
The foregoing and/or other aspects of the present invention are also achieved by providing a door control device for a refrigerator having a refrigerator door, including a movable body coupled to the refrigerator door, wherein the movable body is arranged to move in opposite directions in accordance with opening and closing actions of the refrigerator door, and a dampening unit dampening a rearward movement of the movable body during a door closing action, thus retarding energy generated from door closure.
BRIEF DESCRIPTION OF THE DRAWINGS
These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of preferred embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is an exploded perspective view of a part of a refrigerator having a door control device, according to an embodiment of the present invention;
FIG. 2 is a top view of the part of the refrigerator having the door control device of the present invention;
FIG. 3 is a top view of the part of the refrigerator having the door control device of the present invention, and showing the operation of the door control device of the present invention; and
FIG. 4 is a top view of the part of the refrigerator having the door control device according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
FIG. 1 is an exploded perspective view of a part of a refrigerator having a door control device according to an embodiment of the present invention. FIG. 2 is a top view of the part of the refrigerator having the door control device. FIG. 3 is a top view of the part of the refrigerator having the door control device, showing the operation of the door control device of the present invention. FIG. 4 is a top view of the part of the refrigerator having the door control device according to another embodiment of the present invention.
As shown in FIGS. 1 and 2 , the door control device according to the present invention is used with a refrigerator 100 . The refrigerator 100 having the door control device is configured as follows.
The refrigerator 100 comprises a cabinet 101 with storage compartments, typically a freezer compartment and a refrigerator compartment, with doors 102 hinged to the cabinet 101 to close the respective storage compartments. For ease of description, only one door 102 is shown in the drawings. The refrigerator 100 also has a door control device according to the present invention. The door control device includes a leg casing 103 which is installed in a lower portion of the cabinet 101 . A longitudinal movable bar 104 is axially arranged in the leg casing 103 such that the bar 104 is axially moved under the guide of a channeled rail 105 in opposite directions. A longitudinal side surface of the movable bar 104 is uneven, with four grooves 10 a , 10 b , 10 c and 10 d formed along the uneven surface of the bar 104 at regular intervals. The channeled guide rail 105 is axially installed in the leg casing 103 to hold the movable bar 104 and to guide any axial movement of the bar 104 . A hinge bracket 106 is mounted to the door 102 . A curved link bar 107 is hinged at a first end thereof to an end of the movable bar 104 , and at a second end thereof to the hinge bracket 106 at a position spaced apart from a rotating axis of the door 102 by a predetermined distance in a radial direction from the rotating axis. A control chamber 108 is perpendicularly defined at a sidewall of the leg casing 103 , and a control unit 200 is installed in the control chamber 108 so as to control the axial movement of the bar 104 in a multi-stage manner. A dampening unit 300 is installed in the leg casing 103 at a position behind the rear end of the movable bar 104 , so that the dampening unit 300 dampens a rearward moving action of the movable bar 104 during the door closure. The dampening unit 300 thus dampens the door closing action, and retards the energy generated from the door closure.
The control unit 200 comprises a retractable locking unit and a first spring 21 . The first spring 21 is axially arranged in the control chamber 108 , and the retractable locking unit comprises a roller 22 and a roller bracket 23 . The roller bracket 23 is elastically supported at a first end thereof by the first spring 21 , and rotatably holds the roller 22 at a second end thereof. The roller 22 is thus perpendicularly placed relative to the movable bar 104 , and is elastically retractable, so that the roller 22 is sequentially seated into the four grooves 10 a , 10 b , 10 c and 10 d while rolling on the uneven surface of the movable bar during an axial movement of the movable bar 104 in the leg casing 103 .
The uneven surface of the movable bar 104 , having the four grooves 10 a , 10 b , 10 c and 10 d , is smoothly curved to form a waved configuration, so that the roller 22 rolls on the uneven surface of the bar 104 while being sequentially seated into the four grooves 10 a , 10 b , 10 c and 10 d in response to an axial movement of the movable bar 104 .
The dampening unit 300 is an elastic support unit which elastically supports the rear end of the movable bar 104 . That is, the dampening unit 300 includes a support member designed as an end plate 31 , and an elastic member comprised of two second springs 32 . The end plate 31 is mounted to the rear end of the movable bar 104 , and the second springs 32 are connected to the end plate 31 at two positions while being arranged in parallel, so that the second springs 32 are brought into contact with a rear end wall of the leg casing 103 during a door closing action.
The operational effect of the refrigerator having the door control device of the present invention will be described herein below, with reference to FIG. 3 .
When a user (not shown) rotates the door 102 in a direction as shown by the arrow of FIG. 3 to open the door 102 to a desired open angle, the link bar 107 , hinged to the hinge bracket 106 of the door 102 , is pulled toward the front of the refrigerator 100 , so that the movable bar 104 , hinged at a front end thereof to the rear end of the link bar 107 , is axially moved toward the front of the refrigerator 100 . During the forward movement of the movable bar 104 , the roller 22 rolls on the uneven surface of the bar 104 . In such a case, the uneven surface of the movable bar 104 has the four curved grooves 10 a , 10 b , 10 c and 10 d , so that the roller 22 , held by the roller bracket 23 and elastically biased by the first spring 21 , perpendicularly advances and retracts repeatedly, relative to the uneven surface of the movable bar 104 , during the forward movement of the bar 104 .
When the user opens the door 102 to a desired open angle, for example, 90° as shown in FIG. 3 , the roller 22 rolls on the uneven surface of the forward moving bar 104 , while repeatedly advancing and retracting relative to the uneven surface of the bar 104 , until the roller 22 is seated into the third groove 10 c , which corresponds to the desired open angle of 90°. When the door 102 is opened to reach the desired open angle of 90°, the user releases his/her handling force from the door 102 , so that the roller 22 of the roller bracket 23 , biased by the first spring 21 , is somewhat strongly pushed into the third groove 10 c corresponding to the open angle of 90°. The roller 22 is thus maintained at the position thereof inside the third groove 10 c, and the door 102 is maintained at the open position of the open angle of 90°. That is, the control unit 200 , including the roller 22 , stops the axial movement of the movable bar 104 , and allows the door 102 to be maintained at its open state of the open angle of 90°. Even though external force, such as weight of the door 102 , is applied to the door 102 on which the user does not impose his/her physical force, the control unit 200 prevents an undesired axial movement of the movable bar 104 . The open angle of the door 102 is thus not changed, but the open door 102 is maintained at its open state at the desired open angle.
FIG. 3 shows the door 102 , which is maintained at its open state, at an open angle of about 90°. However, it should be understood that the open angle of the door 102 may be controlled by the variable position of the roller 22 relative to the four grooves 10 a , 10 b , 10 c and 10 d of the movable bar 104 , and the door 102 is maintained at a desired open angle determined by the roller seated in either of the four grooves 10 a , 10 b , 10 c and 10 d.
When the user closes the open door 102 , the second springs 32 are brought into contact with the rear end wall 103 a of the leg casing 103 , and elastically support the movable bar 104 moving backward in the leg casing 103 during the door closing action. Therefore, the second springs 32 dampen the door closing action, thus reducing the door closing speed and retarding the energy generated from the door closure. The door 102 is thus smoothly and gently closed without applying impact energy to the refrigerator.
In an embodiment of the present invention, the movable bar has four grooves to change the open angle of the door between four angles. However, it should be understood that the number of grooves formed on the movable bar may be changed to five or more grooves, or three or less grooves, in order to change the number of open angles of the door which may be selected by a user, as desired. In addition, the grooves for seating the roller of the control unit may be formed on a separate member mounted to a side surface of the movable bar, as illustrated in FIG. 4 .
The control chamber which receives the first spring of the control unit may be integrally formed on the sidewall of the leg casing by outwardly depressing the sidewall, as shown in the drawings. Alternatively, the control chamber may be defined in a separate member which is provided at a predetermined position around the sidewall of the leg casing, as illustrated in FIG. 4 .
In addition, the end plate and the second springs may be provided on the inner surface of the rear end wall of the leg casing, in place of the rear end of the movable bar. Alternatively, the end plate and the second springs may not be mounted to the inner surface of the rear end wall of the leg casing or the rear end of the movable bar, but arranged between the rear end wall of the leg casing and the rear end of the movable bar.
As is apparent from the above description, the present invention provides a door control device for refrigerators, which allows a user to easily control the open angle of a refrigerator door as desired without forcing the user to perform additional work to control the open angle of the door. The door control device also maintains a selected open angle of the door, and dampens a door closing action to retard the energy generated from the door closure. The door control device thus prevents interference between the refrigerator doors and neighboring furniture, appliances or kitchen wall, and is convenient for users of refrigerators. The door control device also prevents rapid door closure.
Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
|
A door control device for refrigerators and a refrigerator with the device. The door control device for a refrigerator having a refrigerator door includes a movable body coupled to the refrigerator door, wherein the movable body is arranged to move in opposite directions in accordance with opening and closing actions of the refrigerator door, and a control unit controlling an opposite directional movement of the movable body in a multi-stage manner.
| 4
|
RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 61/416,063, filed on Nov. 22, 2010. The entire teachings of the above application are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The fabrication of most compound semiconductor devices begins with growth of semiconductor thin films, also known as epilayers, onto a substrate using deposition techniques such as metalorganic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). For both techniques, precise control of the temperature, thickness, growth rate, composition, and doping concentration during film growth is critical. It is desirable to measure these parameters in-situ (during the growth process) to provide information on epilayer properties during growth. These in-situ data may be used to simultaneously provide intra-wafer and inter-wafer uniformity information for each wafer, for example, in a multi-wafer MOCVD reactor. Furthermore, during the epitaxial growth process it is common for many layers to be sequentially deposited on the starting substrate. Once these layers are complete, most metrology techniques only enable analysis of the full structure (i.e., analysis is generally confused by the presence of many similar layers that cannot be clearly or individually identified). Thus, without in-situ monitoring, information about each layer of a complex multilayer structure can be lost. By employing in-situ monitoring, it is possible to simultaneously detect shifts in the properties of the epilayers and minimize time waiting for data collection after film growth. This real-time feedback can allow corrective actions to be taken before additional failed wafers are grown.
[0003] Optical techniques can be used for such in-situ measurements by monitoring the thermal irradiance and reflectivity of thin film structures during growth. Emissivity-corrected pyrometry measurements enable accurate determination of the substrate temperature from thermal irradiance through the Stefan-Boltzmann law. Reflectivity data are collected by directing a light source of known wavelength and intensity onto a substrate, then monitoring the intensity of reflected light returned during epilayer growth. The phase shift of the reflected light, caused by differences in refractive index of epilayers in the structure, results in sinusoidal interference patterns known as Fabry-Perot oscillations. The period of the sine wave provides information regarding growth rate, the amplitude is related to the refractive index change from underlying layers, and the damping can be caused by absorption of the growing film.
[0004] Unfortunately, present optical techniques for in-situ measurements are not well-suited for measuring extremely thin (e.g., <100 nm) epilayers because thin epilayers may not produce one or more full periods of a sinusoidal interference pattern. As a result, it can be difficult to discern the actual thickness of the deposited layer.
[0005] In addition, it can also be difficult to accurately characterize devices that include multiple thin layers, such as Bipolar-High Electron Mobility Transistors (BiHEMTs), which is a semiconductor device with epilayer structure that includes a heterojunction bipolar transistor (HBT) grown on top of a high electron mobility transistor (HEMT) structure. It should be noted that in certain cases the sequence of these layers may be reversed and it may be advantageous to grow the HEMT above the HBT. Such devices are also sometimes known as a Bipolar-Field Effect Transistor (BiFET). The term BiHEMT is used herein to describe any epilayer structure that incorporates the functionality of a bipolar transistor and field-effect transistor. In either case, by combining the advantages of HBTs and HEMTs in the same monolithic structure, BiHEMT can address the demands for greater circuit functionality from a single chip (i.e., increased integration). The BiHEMT circuits are attractive for many applications such as wireless handsets and wireless local area networks. As an example, power amplifier circuits and switches can be integrated in a single BiHEMT chip instead of having a separate power amplifier circuit in an HBT structure and a separate switch circuit in a HEMT structure.
[0006] The combined epilayer structures of a BiHEMT are extremely challenging to produce and can include thirty or more discrete layers, each with strict tolerances for film thickness, composition, doping density, and uniformity across the substrate. For these reasons, there is a need for methods controlling the growth of BiHEMT structures. However, monitoring BiHEMT growth by in-situ techniques is complicated by the fact critical epilayers in this structure can be very thin (e.g., less than 100 nm thick). As such, there is also a need for methods to extract information from the in-situ data in a manner that enables analysis of thin film properties during growth.
SUMMARY OF THE INVENTION
[0007] A method of monitoring deposition of thin films onto a substrate includes the steps of :in-situ monitoring to generate reflectance oscillation data during growth of a thin film; curve fitting the reflectance oscillation data to thereby extract information on the thickness, growth rate, composition, or doping of the thin film; and monitoring the thin film, which comprises at least a portion of a BiHEMT structure.
[0008] In another embodiment, the method calibrates thickness uniformity, and includes the steps of: in-situ monitoring to generate reflectance oscillation data during growth of a thin film; curve fitting the reflectance data to thereby extract information on the thickness, growth rate, composition, or doping of the thin film; and calibrating for thicknesses of multiple layers of a device structure that includes the thin film.
[0009] Compared to other in-situ monitoring techniques, the present in-situ monitoring techniques provide thickness information on thiner layers. For example, the present techniques can derive thickness information from reflectance curves that include only a fraction of an oscillation of an interference pattern. As the complexity of epilayer structures increases, the benefits of in-situ monitoring increase accordingly. In addition, the present techniques make it possible to extract information from the in-situ data in a manner that enables analysis of thin film properties during growth,
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
[0011] FIG. 1 is a plot of reflectance versus time with an oscillation of less than one period, which is typical for certain layers of interest for BiHEMT and related structures.
[0012] FIG. 2 illustrates a technique for fitting a reflectance curve that represents a very thin epilayer (i.e., an epilayer whose reflectance curve is less than half an oscillation).
[0013] FIG. 3 illustrates a technique for fitting a reflectance curve that represents a thin epilayer that is slightly thicker than the epilayer of FIG. 2 (i.e., an epilayer whose reflectance curve includes a reflectance minimum or maximum).
[0014] FIG. 4 illustrates a reflectance range of >1 period with both a maximum and a minimum. Such layers typically enable complete fitting of growth rate, film composition, and doping density by methods of this invention.
[0015] FIG. 5 is a layer structure of a typical GaAs-based BiHEMT structure
[0016] FIG. 6 is a plot of in-situ monitoring data for layers with low, medium, and high doping densities, and illustrates the corresponding differences in reflectance near the reflectance minimum.
[0017] FIG. 7 is a plot of reflectance curves from the same material layer collected with different wavelengths of incident light, highlighting the difference in information available as a function of wavelength.
DETAILED DESCRIPTION OF THE INVENTION
[0018] A description of example embodiments of the invention follows. Embodiments of the present invention relate in general to monitoring deposition of thin films, and in particular to in-situ monitoring during the growth of BiHEMT and similar semiconductor device structures. These embodiments provide methods for applying in-situ monitoring to the growth of BiHEMTs and extracting information about the properties of the deposited thin films from their in-situ reflectance curves. Such curves may only contain a portion of an oscillation, as shown in FIG. 1 .
[0019] FIG. 2 illustrates techniques for fitting very thin layers of less than half an oscillation. The output includes the change in reflectance from start to end of the layer and the slope. Methods of this invention enable extraction of information regarding film thickness changes of such a layer, enabling more precise control than without such methods.
[0020] For slightly thicker layers, FIG. 3 illustrates methods of this invention applied to a layer with optical thickness slightly larger than the film of FIG. 2 , thus enabling capture of one reflectance minimum or maximum and extraction of information concerning epilayer composition change, including doping density.
[0021] FIG. 4 illustrates methods of this invention applied to a layer that has both a reflectance a maximum and a minimum. The output includes the change in reflectance between the extrema (oscillation amplitude) and the change in time from start to the extrema (oscillation period). Such layers typically enable complete fitting of growth rate, film composition, and doping density. It should be noted that even if absolute magnitudes of each of these parameters is not known with precision, in-situ monitoring techniques as provided by methods of this invention enable discernment of very slight differences between position on a wafer (i.e., intra-wafer uniformity) or between multiple wafers being grown simultaneously (i.e., inter-wafer uniformity). The significant advantages associated with such measurement capability will be evident to those of skill in the art.
[0022] A typical GaAs-based BiHEMT structure is shown in FIG. 5 . For such a structure, many of the constituent layers are very thin. Whereas techniques such as photoluminescence (PL) and x-ray diffraction (XRD) can be used to monitor growth of less complex device structures such as GaAs-based, these techniques may not be possible at all for BiHEMTs. Since the HEMT device layers of a BiHEMT are often located below the HBT layers, PL of HEMT layers is not possible due to contributions from overlying layers. Additionally, XRD will be greatly complicated for the same reasons. With in-situ techniques, the buried HEMT layers will also not be affected by measurements of the HBT layers grown above them. More specifically, methods of this invention can provide information regarding the channel layer (often InGaAs), spacer layer (often AlGaAs), and Schottky layer (often AlGaAs). These layers are mentioned as representative examples. Those skilled in the art will appreciate that embodiments of the present invention include other layers not mentioned explicitly in this description.
[0023] Example data from application of in-situ methods to thin layer with differing doping densities is shown in FIG. 6 . Such layers are common, for example, as the base layers of BiHEMT structures (see FIG. 5 ). Although only a partial oscillation is present, note that the minima of the 3 curves correspond to differing reflectance values and can be used to differentiate between films with high, medium, or low doping density. Such changes can lead to significant shifts in the parametric performance of BiHEMT devices. Specifically, even minor changes in the doping of the base layer of BiHEMT devices can lead to changes in the transistor gain.
[0024] FIG. 7 illustrates how different wavelengths of incident light can lead to differences in in-situ reflectance. The two curves of FIG. 7 were collected from the FET channel of a BiHEMT structure. The short wavelength reflectance trace includes both a minimum and a maximum, whereas the long wavelength reflectance trace contains a minimum and a more gradually increasing slope, but no obvious maximum. The short wavelength data can provide more measurement resolution due to the larger fraction of a period used by the curve fitting algorithms.
[0025] For example, the wavelength of the incident light can be used to tailor the in-situ monitoring scheme to the material properties and/or thickness of epilayers of interest. A wavelength of about 950 nm is often used due to the low blackbody incandescence intensity at this energy, which enables the wavelength to be used for both reflectivity and pyrometry measurements. For thin layers or materials with low refractive index, it may be advantageous to use light of shorter wavelength. A wavelength of 633 nm is sometimes used due to the readily available helium-neon laser emitting at this wavelength. However, even shorter wavelength can produce an increased number of oscillations for a given film thickness, thus increasing signal-to-noise of the extracted in-situ data and improving ability to perform curve fitting. Specifically, a wavelength of <600 nm (corresponding to the bandgap energy of Al0.73Ga0.27As) or even <500 nm (energy greater than bandgap of any alloy of the InAlGaAsP system) may be advantageous, depending on the materials and structure of interest.
[0026] However, the wavelength should be optimized within other constraints. As an example, for GaAs device, if the wavelength becomes too short, information about layers such as the emitter cap of a Heterojunction Bipolar Transistor (HBT) or the n+ cap of a High Electron Mobility Transistor (HEMT) may be difficult to extract due to optical absorption. Likewise, if the wavelength becomes too long, less information may be available from layers such as HBT InGaP emitter or AlGaAs Schottky layers. Optimization of multiple wavelengths is important such that data from all layers of interest can be captured with maximum precision.
[0027] The teachings of Rehder, E. M., et al., “In Situ Monitoring of HBT Epi Wafer Production: The Continuing Push Towards Perfect Quality and Yields,” CS MANTECH Conference, May 18-21, 2009, Tampa, Fla., USA, are incorporated by reference in their entirety.
[0028] While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
|
Deposition of a thin film is monitored by illuminating the thin film with an incident beam during deposition of the thin film, wherein at least a portion of the incident beam reflects off the thin film to yield a reflected beam; measuring intensity of the reflected beam from the thin film during growth of the thin film to obtain reflectance; and curve-fitting at least part of an oscillation represented by the reflectance data to obtain information about at least one of thickness, growth rate, composition, and doping of the thin film.
| 2
|
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 11/241,429, filed on Sep. 30, 2005, which issued as U.S. Pat. No. 7,636,842 on Dec. 22, 2009 which claims the benefit of U.S. Provisional Application No. 60/642,691 filed Jan. 10, 2005 which are incorporated by reference as if fully set forth herein.
FIELD OF INVENTION
The present invention relates generally to wireless communication network security. In particular, the invention relates to methods for providing secure communications in a wireless communication system.
BACKGROUND
The nature of wireless communication networks makes them very susceptible to attack. Various security methods are currently implemented to secure wireless communications between wireless transmit/receive units (WTRUs) and other WTRUs, and between WTRUs and wireless access points (APs). These security methods include, for example, various types of encryption, which is the process of encoding information in such a way that only a recipient with the appropriate key can decode the information. Other technologies for protecting wireless data include, for example, error-correcting codes, checksums, hash functions (including message authentication codes), digital signatures, secure socket layer (SSL) technology, and the like.
Various wireless communication networks employ various security technologies. For example, an IEEE 802.11a/b wireless local area network (WLAN) employs wired equivalent privacy (WEP), a symmetric key encryption scheme, for securing wireless communications across a wireless network. An IEEE 802.11i WLAN employs Wi-Fi protected access (WPA) for securing wireless communications across the network. Cellular networks, for example GSM and UMTS networks, use the Authentication and Key Agreement Protocols (AKA) which utilize integrity keys, cipher keys, and anonymity keys. These keys form the basis for the confidentiality, integrity, authentication, and anonymity of the security system. Typically, the security method or technology utilized is dictated by the applicable standards.
These security technologies require large amounts of computational power, thereby creating a potential bottleneck in the speed at which the network operates. For example, a Palm™ III-X handheld WTRU requires 3.4 minutes to perform 512-bit RSA key generation, 7 seconds to perform digital signature generation, and can perform DES encryption for at most 13 kbps. Increased electrical power consumption is an additional drawback associated with highly secure encryption algorithms.
Accordingly, the competing interests of data security and network performance typically result in a fixed level of network security. Generally, the data rate of a network is inversely proportional to the security level of the network. That is, increasing a wireless network's security decreases the rate at which data can be conveyed across the network. The security parameters selected by a network administrator typically optimize these competing interests for a particular use of the wireless communication network.
FIG. 1 is an illustration of a conventional wireless communication network 100 operating with a fixed security level. The network shown in FIG. 1 is a wireless local area network (WLAN), such as one typically found in homes and small businesses. An access point 110 connects the WLAN to the Internet 120 and an intranet 125 , and routes data transmitted between a plurality of WTRUs 130 generally, and 130 1 , 130 2 , 130 3 specifically, within a trust zone 140 extending a predetermined distance from the wireless access point 110 . The WTRUs 130 possess the appropriate encryption key or other required information, depending on the nature of the security technology utilized by the network 100 .
The security level maintained among devices operating within the trust zone 140 of the network 100 is static; it will not change unless the security settings are adjusted or the security is turned off by the system administrator. To illustrate, an intruder WTRU 150 is located outside the trust zone 140 at position A. When the intruder WTRU 150 enters into the trust zone 140 at position B, the security level of the system remains unchanged. The intruder WTRU 150 either has the necessary encryption key or other information as required by the security technology currently in use, or it does not. If the intruder WTRU 150 possesses the appropriate encryption key or other necessary information, the intruder WTRU 150 may then access the network 100 . If, however, the intruder WTRU 150 does not possess the required encryption key or other necessary information, the intruder WTRU 150 will be unable to communicate with the network 100 .
Accordingly, the network 100 unnecessarily utilizes large amounts of resources on security when only trusted WTRUs 130 are operating within the network 100 . As a result, the network 100 sacrifices the ability to provide higher data rates by maintaining unnecessarily high security levels when only trusted WTRUs 130 are operating within the trust zone.
Therefore, a method for providing variable security in a wireless communication network is desired.
SUMMARY
The present invention is a system and method for providing variable security levels in a wireless communication network. The present invention optimizes the often conflicting demands of highly secure wireless communications and high speed wireless communications. According to a preferred embodiment of the present invention, various security sensors are scanned to determine the likely presence of an intruder within a predetermined trust zone. If an intruder is likely present, the security level is changed to the highest setting, and consequently a lower data rate, while the intruder is identified. If the identified intruder is in fact a trusted node, the security level is returned to a lower setting. If the identified intruder is not a trusted node, the security level is maintained at an elevated state while the intruder is within the trust zone.
BRIEF DESCRIPTION OF THE DRAWINGS
A more detailed understanding of the invention may be had from the following description of a preferred embodiment, given by way of example and to be understood in conjunction with the accompanying drawings wherein:
FIG. 1 is an illustration of a conventional wireless communication system having a predetermined trust zone, wherein a plurality of trusted WTRUs are operating, and an intruder WTRU enters the trust zone;
FIG. 2 is a flow diagram of a method for providing variable level security in a wireless communication system according to a currently preferred embodiment of the present invention;
FIG. 3 is an illustration of a wireless communication system having a predetermined trust zone wherein a plurality of trusted WTRUs are operating and variable level security is implemented in accordance with the present invention; and
FIG. 4 is a block diagram of a node for performing variable level security in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described in more detail with reference to the drawing figures wherein like numerals indicate like elements.
As referred to herein, a wireless transmit/receive unit (WTRU) includes, but is not limited to, a cell phone, pager, laptop, user equipment (UE), mobile station (MS), a fixed or mobile subscriber unit, or any other device capable of operating in a wireless communication system. As referred to herein, the term ‘access point’ includes but is not limited to a base station, a Node-B, a site controller, or any other type of interfacing device in a wireless environment. As referred to herein, a ‘node’ may be either a WTRU or an access point. As referred to herein, the term ‘trust zone’ means a physical space in which the network is able to determine the likely presence of a WTRU or other mobile device, operating in an expected manner. As referred to herein, the term ‘intruder’ means any WTRU or other mobile device operating within a trust zone that is not associated with the wireless communication network.
In a preferred embodiment of the present invention, a wireless communication system dynamically changes its security level based on the presence of an intruder within a trust zone. For simplicity, the invention will be described in the context of an 802.11 WLAN using WEP security. It should be understood by those skilled in the art that this implementation of the present invention is exemplary and not limiting, and the invention may be carried out in various types of wireless communication networks, such as, for example, 3G, 802.x, GPRS, or the like, using various security protocols such as symmetric encryption, asymmetric encryption, error-correcting codes, checksums, hash functions (including message authentication codes), digital signatures, SSL, or the like, alone or in combination.
Referring to FIG. 2 , a method 200 for providing variable level security in a wireless communication network according to a preferred embodiment of the present invention is shown. The method 200 begins when the wireless communication system is brought online. Alternatively, a system administrator may enable and disable the variable level security method as desired. Various security sensors scan the trust zone for intruders, (step 210 ). The various security sensors may include, for example, individually or in various combinations, infra-red sensors, video monitoring sensors, photo-electric sensors, motion sensors, audio sensors, or the like. Traditional radio frequency (RF) sensors such as antennas, smart antennas, or the like may also be used to scan for likely intruders. Various signal quality metrics, such as, for example, channel impulse response (CIR) for signal-band channel changes may also be used as a means of detecting intruders. Additionally, spatial/frequency/temporal CIR or the like may be used.
The system administrator may adjust the settings and parameters of the various security scanning devices to adjust their thresholds and sensitivity for determining whether an intruder is likely present. It is then determined, based on the security sensor scans, whether any intruders are likely present, (step 220 ). If no intruder is detected, the method returns to step 210 for further scanning.
If an intruder is detected, the security level of the network is immediately raised to a level higher than the current level, (step 230 ). This elevated security level may be, for example, where the wireless system is utilizing public key encryption (e.g. wired equivalent privacy (WEP)) for security, a longer public key. For example, the key length may be increased from 64 bits in length to 128 bits in length, providing a higher level of security.
Alternatively, when the wireless system is utilizing asymmetric encryption techniques, the frequency of the key changes may be increased to provide a higher level of security. Trusted users may be alerted to the presence of a likely intruder and notified of the resulting increase in security level and associated decrease in data rates. Alternatively, when communications in a wireless network are both encrypted and unencrypted, an elevated security level may be provided by restricting all unencrypted communications, only allowing encrypted communications. Alternatively, when either the AP or the WTRU, or both, are equipped with switched beam antennas, a higher level of security may be provided by beam steering techniques designed to create null areas covering the intruder's spatial location. Methods for using beam steering techniques in this manner are well known in the art. These techniques may be used in combination or alone, providing an elevated security level as desired.
The system administrator determines the various levels of security to which the system will change upon the detection of a likely intruder, as desired. Alternatively, the system can be set by the system administrator to stop transmitting data all together. However, this may not be practical in certain types of communication systems, such as, for example, a 3G wireless communication system implemented primarily for voice communications.
While the system is operating at an elevated security level, the likely intruder is identified, (step 240 ). Where the intruder is a wireless communication device, identification of the intruder may occur, for example, via polling, signaling, referencing a database, remote attestation, whereby a challenger can ascertain the security properties of an intruding device, RF channel sensing, and/or CIR signatures. Various other identification techniques are well known in the art.
The method 200 then determines whether the identified intruder is trusted, (step 250 ). This may include determining whether the identified intruder is operating in an expected manner. Where the intruder is another wireless communication device, the intruder may at some point in time attempt to register with the network. Such a process of registration will identify the intruder to the network. A database of known and trusted devices may or may not be referenced for this determination. In other cases, for example, when the policy is to stop data transmission or to null the intruder's spatial location, intruder identification may not be necessary.
If the network determines the identified intruder is not trusted, or the network is unable to identify the intruder as trusted, an elevated level of security is maintained while the identified intruder is likely present within the trust zone, (step 260 ). If, on the other hand, the network determines the identified intruder is trusted, the security level is set to a predetermined security level appropriate for use with the identified intruder, (step 270 ). When beam steering is used to null the signals covering an intruder's location, an intruder determined to be a trusted intruder is allowed into the network by ceasing the nulling. In either case, the method 200 returns to step 210 for further scanning.
Typically, decisions to alter security settings are first made locally where the intruder is identified. Then the intruder identification and any additional information, such as any classification information, location information, or the like, is distributed throughout the network. For example, in a WLAN, the identification of an intruder may occur at both a WTRU and at the AP. (It should be noted that since APs typically possess more functionality than WTRUs, it is more likely that the AP will identify an intruder.) Any station that identifies an intruder immediately changes its own security policy, and begins notifying other nodes of the network.
Referring to FIG. 3 , an illustration of a wireless communication network operating in accordance with the present invention is shown and generally designated 300 . The network 300 , purely by way of example, is an IEEE 802.11x network utilizing WEP security technology. An access point 310 wirelessly connects a plurality of WTRUs, generally designated 330 , to the Internet 120 and an intranet 125 . A trust zone 340 extends a predetermined distance from the access point 310 . The size or extent of the trust zone may be modified by the system administrator based on a variety of parameters as desired. WTRUs that are identified by the network and determined to be trusted WTRUs are designated 330 1 , 330 2 , and 330 3 specifically, and generally 330 .
In order to demonstrate the operation of variable level security of the present invention, two examples of variable level security will now be described. When an intruder WTRU 350 is positioned outside the trust zone at position A, the network security level is set as desired for trusted communications. Typically, this security level setting will be a relatively low level of security so that a higher level of data throughput is achieved. For example, where the network is using WEP encryption to secure wireless communications, a relatively low level of security is a 64-bit key, or no key at all. When the intruder WTRU 350 enters the trust zone 340 at position B, various security sensors determine the likely presence of an intruder. Upon determining the presence of the intruder WTRU 350 at position B, the network raises the security level, for example, the encryption key length may be set at 128 bits. The network attempts to identify intruder WTRU 350 . In this first example, the intruder WTRU 350 is not associated with the network 300 and is determined to not be trusted. Accordingly, the security level is maintained at an elevated level while the intruder WTRU 350 is located at position B. When intruder WTRU 350 exits the trust zone 340 and is located at position C, the network 300 may return to a lower security level.
Alternatively, referring still to FIG. 3 , in a second example an intruder WTRU 360 that is in fact a trusted WTRU is positioned outside of the trust zone 340 at position D. Upon entering the trust zone 340 , intruder WTRU 360 is located at position E and is sensed by various network security sensors associated with the network 300 . Upon this determination that an intruder is likely present, the security level of the network 300 is raised. The intruder WTRU 360 is then authenticated by the network 300 as a trusted WTRU, using methods well known in the art. The security level of the network 300 is then returned to its original relatively low security level.
In an alternative embodiment of the present invention, again referring to FIG. 3 , the variable security levels may be configured to correspond to various WTRUs that are within the trust zone of the network. For example, referring again to FIG. 3 , intruder WTRU 360 that is in fact a trusted WTRU, moves inside the trust zone 340 to position E. The security level is raised and the intruder WTRU 360 is authenticated. When the intruder WTRU 360 exits the trust zone 340 by moving to position F, the security level is lowered, but preferably not to its original security level. The security level is preferably set at an intermediate level. In this manner, the variable security method of the present invention provides a wireless variable security method that is configurable to the specific WTRUs operating within the network 300 , thus optimizing transmission speed and network security to the specific network condition.
It should be understood by those of skill in the art that many levels of security may be implemented depending on the perceived threat to network security as measured by various sensors throughout the communication system. A system administrator may set the various levels as desired.
It should be understood by those of skill in the art that variable level security may be achieved by utilizing other well-known data protection schemes. These techniques include, but are not limited to, varying the parameters of error-correcting codes, checksums, hash functions (including message authentication codes), digital signatures, various ciphers, changing the type of cipher altogether, changing antenna patterns, fully or partially interrupting transmissions, varying transmit power, or the like.
Referring to FIG. 4 , a node 400 for performing variable level security in a wireless communication system in accordance with the present invention is shown. The node 400 may be an access point, a WTRU, or any other device capable of operating in a wireless environment. The node 400 includes an intruder detector 410 . The intruder detector 410 is configured to detect the presence of intruders within a trust zone. More specifically, the intruder detector 410 receives and processes data regarding intruders via antenna 420 wherein the antenna 420 is operating as a sensor. The antenna 420 may also receive data regarding intruders from other sensors deployed throughout the trust zone. In another embodiment of the present invention, the node 400 may be configured to receive data regarding intruders from sensors that are hardwired to the node 400 via port 430 . As mentioned above, the sensors may be various types of sensors for detecting intruders. In a preferred embodiment of the present invention, upon detection of an intruder, the intruder detector 410 notifies the security level controller 450 which immediately sets the network security level via antenna 420 to the most secure security level. Alternatively, upon detection of an intruder, the security level is raised to an elevated security level predetermined by a system operator. The intruder detector 410 may alternatively be provided with a processor for increasing the security level upon detection of an intruder within a trust zone so that it may raise the security level without interfacing with the security level controller 450 .
The intruder identifier 440 receives data from the intruder detector 410 regarding detected intruders. The intruder identifier 440 determines the identity of an intruder and whether the intruder is in fact a trusted device or not. As disclosed above, various authentication methods may be used in identifying and determining the trustworthiness of the intruder, for example, via polling, signaling, referencing a database, remote attestation, whereby a challenger can ascertain the security properties of an intruding device, RF channel sensing, CIR signatures, and other methods well known in the art. A database of trusted devices may be used in determining whether an intruder device is trusted. Alternatively, determining whether the device is trusted may include determining whether the identified intruder is operating in an expected manner.
The node 400 further includes a security level controller 450 for determining and managing the security level of the communication system. The security level controller 450 receives data regarding the identity and trust status of a detected intruder from the intruder identifier 440 . When the intruder identifier 440 determines an intruder is not a trusted device, the security level controller 450 raises the security level to a more secure security level. When the intruder identifier 440 determines an intruder is in fact a trusted device, the security level controller 450 may lower the security level to a lower security level, thereby increasing data rates. Alternatively, an intermediate security level may be utilized, as desired, according to operator preference. In a preferred embodiment, when a security level has previously been elevated upon detection of an intruder within the trust zone, the security level is maintained in an elevated state upon determination that the intruder is not a trusted device. The elevated security state may be the same or different from the security level in place prior to detection of the intruder. The security level controller 450 communicates changes in the security level and the presence of both trusted and not trusted intruders to other nodes operating within the communication system via antenna 420 .
The security level controller 450 further controls and stores the various security data required to implement variable level security. This data includes, for example, encryption keys, length of the current encryption keys, hash functions, authentication keys, SSIDs, and the like. When asymmetric cryptography is used, the security level controller 450 controls the cycling of the public keys.
The intruder detector 410 , intruder identifier 440 , and the security level controller 450 may be incorporated into an integrated circuit (IC) or be configured in a circuit comprising a multitude of interconnecting components or any other type of circuit and/or processor. As one skilled in the art should realize, the functions of the various components of node 400 may be performed by various other components or combinations of components, and/or may be performed in different components or combinations of components than those described herein.
Although the present invention has been described with reference to the preferred embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the invention.
|
A system and method for providing variable security levels in a wireless communication network. The present invention optimizes the often conflicting demands of highly secure wireless communications and high speed wireless communications. According to a preferred embodiment of the present invention, various security sensors are scanned to determine the likely presence of an intruder within a predetermined trust zone. If an intruder is likely present, the security level is changed to the highest setting, and consequently a lower data rate, while the intruder is identified. If the identified intruder is in fact a trusted node, the security level is returned to a lower setting. If the identified intruder is not a trusted node, the security level is maintained at an elevated state while the intruder is within the trust zone.
| 7
|
This appln. claims benefit of provisional appln. 60/078,016, Mar. 14, 1998.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention generally relates to holding a desired tension in a length of thread (yarn, wire, etc.) during interlacing with other threads. The invention is more specifically related to the application of different tensions between threads and variable lengths of time for holding the tension.
In particular, it concerns an apparatus for use with an interlacing apparatus, for example, a weaving loom, which is positioned just outside of the fabric selvage to control the tension of an inserted thread as it is stretched across the weaving loom thru an open shed.
2. Prior Art
It has been known that tensioning devices are desirable to control the threads and apply a predetermined tension to the thread during a certain time frame which is related to thread insertion. It is important to insert the thread with a specific tension to avoid slack or tight threads which diminish the product's quality. If the tension is too low, thread loops protrude from the fabric surface, or if the tension is too high, the fabric edges are pulled toward the fabric's center.
U.S. Pat. No. 4,976,292 describes a tensioning device that grips and holds the free end of an inserted thread while applying tension in synchronism with the insertion motion. The synchronized motion is achieved by the free end of the thread being pushed into the holding device during a beat-up motion.
In U.S. Pat. No. 5,105,856, the tensioning device is based on the concept that a thread guide pin, driven up and down in synchronism with the beat-up motion stretches, tensions the thread, either due to the return motion of the beat-up or by an additional component.
In U.S. Pat. No. 4,513,792, the tensioning device has a rod which oscillates at the cadence of the weaving machine transversely of the inserted thread position. The rod deflects the thread to a retaining element that holds it during the rod's upward movement. This device requires elaborate, synchronized control of the tensioner's movement.
In U.S. Pat. Nos. 5,462,094 and 5,725,029, the disclosed devices use brakes to control the thread's tension. Such brakes may control the tension during the process where a thread is paid out in a weaving loom. Such brakes may also be combined with sensors to stop the machine motion if the tension is too low or too high during the thread laying out process. Such brake systems may control different tensions as when multiple threads are inserted.
SUMMARY OF THE INVENTION
The present invention provides a tensioner for gripping an inserted thread and applying or removing tension based on the thread's inserted tension. Through the use of sensors in the gripping means, the as inserted tension is compared to a desired value in a controller which controls the direction of rotation by the drive motor connected to the tensioner. The present invention provides for a thread positioner which cooperates with the gripper to assure that the threads are repeatedly gripped at the same general location. This expedites the detection of the inserted tension and avoids false initial readings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the thread tensioner of the invention in a shuttle weaving loom as viewed from the weaver's position.
FIG. 2 illustrates the preferred travel path of the present invention as seen from either position A or B of FIG. 1 .
FIG. 3 is a side elevation illustrating the position of the thread tensioner relative to the slay and the reed as seen along the line 3 — 3 of FIG. 2 .
FIG. 4 is a side elevation of a thread positioner according to the invention for locating the thread relative to the thread tensioner.
FIG. 5 illustrates the thread positioner and thread tensioner assembled in an apparatus according to the present invention.
FIG. 6 illustrates the location of the present invention relative to a thread path along the slay.
FIG. 7 illustrates a block diagram of the sequence of events of the invention.
FIG. 8 illustrates a thread tensioner control and display panel.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1 shows a section of the slay beam ( 1 ) in the thread insertion position. The shuttle 5 is in its end position after having inserted the thread 4 . Preferably, a thread tensioning apparatus 6 or 7 is placed on either side of the loom just outside of the fabric edge. Thus, each apparatus 6 or 7 will be programmed to engage a thread traveling to a respective edge of the loom. During thread insertion, the thread tensioner 6 and 7 are in the rest position, illustrated as position R in FIG. 2 . As soon as the shuttle 5 , traveling in it's given direction, passes sensor 8 or 9 , which may be optical sensors, it signals the tensioning apparatus 6 or 7 to start the tensioning process. Since the tensioners operate in the same manner, the remaining description will refer to only tensioner 6 . The tensioning apparatus 6 rotates into position X to engage the thread 4 and travels in the direction of the shuttle A to B in FIG. 1, through positions Y and Z until the desired tension is applied to the thread 4 . The tensioning apparatus rotates to a stop at position Z and the thread tension is held until the inserted thread is locked by the closing of the shed.
As the loom changes in accordance with the pattern, a sensor signal created by the pattern causes the tensioning apparatus 6 to free the thread from its grip. The tensioner 6 is then free to return to the rest position. The tensioning process is then repeated as the next thread is inserted.
With reference to FIGS. 2 and 3, the position of the invention relative to the loom can be seen. In FIG. 3, a reed 10 is illustrated on the slay beam 1 . The thread 4 is illustrated in the closed gripper 18 of tensioner 6 with the thread 4 positioned above the surface of beam 1 . The mounting brackets, 11 , 15 , 16 and 17 are affixed to the backside of the slay beam 1 so as to hold the tensioning device in the thread's travel path. Tensioner 6 includes a motor 12 , such as a stepper or servo motor, a torque sensor 13 connected to the motor's shaft, and tensioner arm 14 mounted on the torque sensor 13 for holding the gripper 18 . With the gripper 18 open, the tensioner is in the rest position, to enable the shuttle 5 to pass underneath it. Recognition that a shuttle 5 has passed sensor 8 of FIG. 1, activates the motor 12 and begins rotation of arm 14 . When the tensioner passes position X in FIG. 2, a controller signals the gripper 18 to close. As soon as the gripper has closed, the tensioner 6 starts to stretch and tension the thread. The position Y where the gripper is fully closed is generally perpendicular to the thread path of travel. The final tension position Z is where motor rotation stops, because either the servo motor reaches an electric resistance equal to the set resistance corresponding to the desired tension, or the torque sensor responds having reached the torque equal with the tension multiplied by the tension arms distance between the gripper and stepper motor's shaft. In it's final tension position the tensioner holds the tension in the thread until the controller opens the gripper, frees the thread, and rotates the gripper and tension arm back into its rest position R.
FIG. 5 illustrates a thread guide 27 . The guide 27 has a radius that guarantees that a thread held in gripper 18 will be in the same position relative to the motor's shaft and therefore guarantees that the thread's stop position will be based on torque sensing. The thread positioning device shown in FIG. 4, has opposed fingers 19 that are driven by air cylinder 20 via arms 21 which are rotatably fixed in the accurate recesses of opposed fingers 19 . Extension of the cylinder 20 , because the arms 21 are pinned to cylinder 20 by a common pin and to fingers 19 by an individual pin, causes the fingers 19 to move in opposite directions from the vertical to positively position the thread in the same location proximate to gripper 18 . Using the positioner 50 is preferred as it is believed to increase the repeatability of thread positioning.
The described thread tensioner apparatus is also able to adjust to the requested thread tension even though the inserted thread tension is higher than the desired tension. When the tensioner registers a tension higher than the desired tension, the respective tensioner, 6 or 7 will then rotate in the reverse direction to thread insertion, to pull thread from the thread supply i.e., shuttle, and reduce the thread tension. As soon as the tensioner detects a tension in the desired range the rotation stops.
With the above operational explanation in mind, the operation of the stepper motor and torque arm can be better understood. The stepper motor is a brushless permanent magnet motor with a full step increment of 1.8 degrees. It is possible to use half or micro steps which yields increments of 0.9 to 0.0144 degrees. Steppermotors may be operated at speed rates up to 20,000 steps per second, and can provide holding torque ratings from 60 to 5330 oz-in (42.4 to 3764 Ncm) with both windings energized. In the present invention the stepper motor operates on phase switched dc power. The motor shaft advances in steps of 1.8 degrees (200 steps per revolution) in the full step mode, and 0.9 degree steps (400 steps per revolution) when in the half step mode. Power transistors connected to flip-flops are used for switching. The motor has a high holding torque, when it is not being stepped, because current is maintained on the motor windings. A suitable stepper motor is available from Superior Electric, Bristol, Conn. as model M063-LS09. The stepper motor may be controlled by a driver, model SS2000MD4-M available from the same manufacturer.
With the above in mind, it can be appreciated that the torque applied or created by the tensioner 6 or 7 can be measured with commercially available strain gauges which will be well known in the art. The strain gauge will detect the initial condition when the thread 4 is engaged by the gripper 18 . If the initial tension is too low, the most common condition, the strain gauge will signal the detected tension to the controller which will compare that value to the desired value. Once the condition is determined, the controller will activate the stepper motor in the proper direction to tension the thread. If the tension is too high, the sequence will be the same however, the stepper motor will be activated in the opposite direction.
It will be appreciated that the number of tensioner devices may vary based upon the insertion equipment. Likewise, the gauge of the device will depend on the diameter or denier of the inserted thread.
In FIG. 8 the final tension condition is indicated by 3 LED's (# 24 ) in range, (# 25 ) low range, (# 26 ) high range. By programming the tension range conditions, individual output signals which are dependent upon the controlled thread tension can be displayed. For example, the high and low range output signals can be used to stop the machine and the operator is then able to determine by observing the LEDs the reason the machine has stopped. Instead of LEDs a screen or other components may be used.
|
A tensioner for gripping an inserted thread in a weaving shed and applying or removing tension based on the thread's inserted tension. Through the use of sensors in a thread gripper, the inserted thread tension is compared to a desired value in a controller which controls the direction of rotation of a drive motor connected to the tensioner. A thread positioner which cooperates with the gripper assures that the threads are repeatedly gripped at the same general location. This expedites the detection of the inserted tension and avoids false initial tension readings.
| 3
|
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority benefit of Taiwan application serial no. 95145600, filed on Dec. 7, 2006. All disclosure of the Taiwan application is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present, invention relates to a light pipe, and more particularly to a light-guiding structure for preventing the interference of light waves.
2. Description of Related Art
Generally, most electronic devices take the signal light emitted by light emitting diodes (LEDs) as the indicating signal to show current operation state of the electronic device. However, since the position where the LED disposed from the surface of the casing of the electronic device is usually separated by a distance, a light pipe must be used to transmit the signal light wave, and display it on the surface of the casing.
Referring to FIG. 1 , it is a schematic view of the configuration of conventional light pipes. Each LED 100 is disposed on one end of respective light pipe 110 , which emits light wave with a different wavelength such as red light, blue light, or green light. When the light wave is transmitted in each light pipe 110 , the user can see from each end of light pipes 110 that the indicating lamp is ON or Off state, so as to determine the current operation state of the electronic device.
However, due to the limitation on formation, when the light pipes 110 are fabricated, the light pipes 110 are connected through the plasticizing process by the fixing connecting portion 120 , such that the light pipes 110 can be fixed on a suitable position in the electronic device. However, it may cause the light wave transferring from a light pipe 110 to another light pipe 110 through the fixing connecting portion 120 , as a result, the light waves are mixed and the light signals are irregular. Therefore, how to prevent the light waves emitted by the LEDs 100 from being transferred into another light pipe 110 is an urgent issue.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a light-guiding structure, which is applicable for preventing the mutual interference of the light waves in the light pipes.
The present invention provides a light-guiding structure, which comprises a plurality of light pipes, a plurality of connecting portions, and a fixing socket. The light pipes are disposed on the fixing socket, and they are connected with the connecting portions. A to-be-destroyed portion is formed between the connecting portions. Furthermore, the fixing socket has a destructive structure corresponding to the to-be-destroyed portion, and the destructive structure is used to destroy the to-be-destroyed portion, so as to disconnect the connecting portions.
In an embodiment of the present invention, a plurality of LEDs is disposed on one end of each light pipe for emitting light waves into the light pipe, and the other end of the light pipe displays the light wave transmitted via the light pipe, so as to be used as an indicating lamp.
In an embodiment of the present invention, the fixing socket comprises a plurality of buckling portions, and the light pipes are fixed on the fixing socket with the buckling portions.
In an embodiment of the present invention, the fixing socket comprises a plurality of plugs, and the light pipes are fixed on the fixing socket with the plugs.
In an embodiment of the present invention, the destructive structure can block the transmission path of the light wave, so as to prevent the mutual interference of the light waves when passing through the connecting portions between two light pipes. The destructive structure is, for example, a sharp object, a notch structure, or a quirk, and it can cut off the to-be-destroyed portion between the connecting portions under an external force. The to-be-destroyed portion can be a necked-down portion, or can have at least one through hole.
The present invention further provides a light-guiding structure, which comprises a plurality of light pipes, a plurality of connecting portions, and a fixing socket. The light pipes are disposed on the fixing socket, and they are connected with the connecting portions. A to-be-destroyed portion is formed between the connecting portions. Furthermore, the fixing socket has a plurality of light shielding walls, and the light pipes are separated by the light shielding walls. The light shielding wall has a destructive structure corresponding to the to-be-destroyed portion, and the destructive structure is used to destroy the to-be-destroyed portion, so as to disconnect the connecting portions.
The light-guiding structure cutting off the to-be-destroyed portion is employed in the present invention, such that the light waves cannot be transmitted through the connecting portions, so as to prevent the mutual interference of the light waves.
In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a schematic view of the configuration of conventional light pipes.
FIG. 2 is a schematic view of a light-guiding structure according to an embodiment of the present invention.
FIG. 3 is a schematic view of the configuration of a light-guiding structure according to an embodiment of the present invention.
FIG. 4 is a schematic cross-sectional view of the light pipes of FIG. 3 fixed on a fixing socket.
DESCRIPTION OF EMBODIMENTS
FIG. 2 is a schematic view of light-guiding structure according to an embodiment of the present invention, and FIG. 3 is a schematic view of the configuration of a light-guiding structure according to an embodiment of the present invention. It should be firstly noted that, the light-guiding structure in this embodiment can be applied for the indicating lamp of a display, a portable computer, a tablet PC, a personal digital assistant (PDA) or the like to display the operation state of the electronic device. However, those of ordinary skill in the art may apply it on any indicating lamps, point light sources, or linear light sources, which is not limited herein.
Referring to FIGS. 2 and 3 , the light-guiding structure 200 includes a plurality of light pipes 210 , a plurality of connecting portions 220 , and a fixing socket 230 . Before the light pipe 210 is assembled on the fixing socket 230 , the light pipes 210 are connected with the connecting portions 220 , such that the light pipes 210 can be integrally assembled on a suitable position in the electronic device. The light pipe 210 and the connecting portions 220 are, for example, injected by a forming mold and then formed through molding releasing process. Each light pipe 210 has a light entrance end 212 and a light exit end 214 , and the light entrance end 212 is corresponding to each indicating light source (not shown) of the electronic device, for example, a red LED, a green LED, or a blue LED.
The light emitted by the indicating light sources may enter from the light entrance end 212 of the light pipe 210 , and transmit to the light exit end 214 through the light transmission part 216 , for the user to see the indicating lamp to be bright or dark to determine the operation state of the electronic device. As shown in FIG. 3 , a substrate 250 has a partition plate 252 , and the light exit end 214 of each light pipe 210 is exposed on the partition plate 252 , to be used as the indicating lamps.
In order to prevent light leakage, the fixing socket 230 has a plurality of light shielding walls 232 , and each light pipe 210 is disposed on the fixing socket 230 and separated by the light shielding walls 232 , so as to reduce the light refraction effect, and thereby obstructing the light waves. However, since the light waves may still pass through the light shielding walls 232 via the connecting portions 220 , it is not sufficient for blocking the interference of the light wave by way of merely using the light shielding walls 232 of the fixing socket 230 . In the forming process, the light pipes 210 are connected together through the connecting portions 220 , which is convenient for the subsequent assembling operation. But after the assembling process, if the connecting portions 220 are still maintained on the light pipes 210 , the possibility of the interference of the light waves is increased without any benefits. Therefore, in the present invention, the connecting portions 220 are destroyed to block the transmission path of the light waves.
Referring to FIG. 3 , it is a schematic view of the configuration of a light-guiding structure according to an embodiment of the present invention. A to-be-destroyed portion 222 is formed between the connecting portions 220 , and the fixing socket 230 correspondingly has a destructive structure 234 , such that when an external force is applied to the to-be-destroyed portion 222 , the to-be-destroyed portion 222 is cut off by the destructive structure 234 . In order to easily destroy the connecting portions 220 , the sectional area of the to-be-destroyed portion 222 can be smaller than that of the other regions without being destroyed, for example, a through hole 222 a or a necked-down portion is formed on the to-be-destroyed portion 222 between the connecting portions 220 .
In this embodiment, the destructive structure 234 can be disposed on the light shielding wall 232 in a form of protruding from the light shielding wall 232 to form a sharp object. In another embodiment, the destructive structure 234 can also be formed by opening a notch structure or a V-shaped quirk on the light shielding wall 232 , such that the connecting portions 220 are destroyed. As shown in FIG. 3 , after the light pipes 210 has been assembled, the to-be-destroyed portion 222 and the through hole 222 a of FIG. 2 are destroyed, which cannot be seen in FIG. 3 . The destructive structure 234 is not limited to be disposed on the light shielding wall 232 , and it can be separately disposed on the fixing socket 230 depending upon the actual conditions.
FIG. 4 is a schematic cross-sectional view of the light pipes of FIG. 3 fixed on a fixing socket. In order to firmly fix each light pipe 210 on the fixing socket 230 , the fixing socket 230 further has a plurality of plugs 240 and a plurality of buckling elements 242 and 244 . The plugs 240 can be inserted into a base 210 a of the light pipe 210 , and the plugs 240 are heated and pressed, so as to be melted and fixed on the base 210 a . Furthermore, the buckling elements 242 and 244 are arranged on two sides of the light pipes 210 in pairs. Once an external force is applied on the light pipes 210 , the buckling elements 242 and 244 are deformed under the external force, such that the light pipe 210 passes between the buckling elements 242 and 244 and thereby being fixed under the buckling elements 242 and 244 . Each light pipe 210 can be fixed on the fixing socket 230 through the plugs 240 and the buckling elements 242 and 244 , so even if the connecting portions 220 are destroyed, the assembling reliability is not affected.
To sum up, the light-guiding structure of the present invention includes a plurality of light pipes, a plurality of connecting portions, and a fixing socket. A to-be-destroyed portion is formed between the connecting portions, and the fixing socket has a corresponding destructive structure. When a force is applied on the to-be-destroyed portion, the to-be-destroyed portion is cut off by the destructive structure, so that the light waves cannot be transmitted through the connecting portions. Furthermore, the fixing socket further has a plurality of light shielding walls disposed between two neighboring light pipes, so as to prevent the interference of the light waves, and thereby preventing the neighboring light sources from affecting each other.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
|
A light-guiding structure including a plurality of light pipes, a plurality of connecting portions and a fixing socket is provided. The light pipes are disposed on the fixing socket, and the light pipes are connected together by the connecting portions. At least one to-be-destroyed portion is formed between the connecting portions. In addition, the fixing socket has at least one destructive structure for disconnecting the connecting portions from each other by destroying the to-be-destroyed portion. Therefore, the interference caused by the light wave passing through the connecting piece is avoided.
| 6
|
GOVERNMENT INTEREST
The U.S Government has rights in this invention pursuant to Contract No. ZAK-8-17619-33 between the Department of Energy and the University of Delaware.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to solar cells and other semiconductor devices. More particularly, the invention relates to a process for forming ultra-thin semiconductor films for solar cells.
2. Description of the Related Art
Photovoltaic devices, or solar cells, use the specific conductivity properties of semiconductors to convert visible and near visible light energy from the sun into usable electrical energy. In the past, solar cells for use in solar power generation have been formed of single crystal or polycrystalline silicon. However, such solar cells are expensive and difficult to mass-produce, as they require much time and energy for crystal growth and also complex subsequent steps.
Thus, thin film semiconductor solar cells have been developed. Thin film solar cells are typically prepared by forming a thin film layer of a semiconductor compound on a substrate such as a glass or stainless steel sheet, through relatively simple manufacturing steps. Thin film solar cells formed using Group II-VI or Group I-III-VI 2 compound semiconductors are particularly desirable, since they can be produced at low cost and with a good mass-production capability, and because films such as CdS and CdTe can be formed uniformly on substantially the entire surface of a glass substrate using a relatively easy process.
However, such thin film solar cells and their manufacturing processes are still in need of further improvement. This is because thin film solar cells are known to have a lower conversion efficiency than silicon crystal photovoltaic devices, and greater manufacturing costs. One preferred process known in the art for the formation of Group II-VI compounds is chemical bath deposition, which has various drawbacks. This process for forming such compounds often exhibits low utilization of the Group II species, leading to the generation of large amounts of hazardous waste by-products, thus increasing processing costs. There is also a problem with particulate formation caused by reaction in the bath, known as homogeneous nucleation, of product species prior to application to the substrate. This leads to imperfections in the resulting film.
Thus, it would be desirable to provide an improved process for forming low cost, high quality thin film solar cells having high conversion efficiencies. It would be further desirable to provide a process which exhibits an increased utilization of Group II species, resulting in the formation of less hazardous waste and thus lowering processing costs. It would also be desirable to limit the formation of particulates formed by homogeneous nucleation of product species, to thereby form uniform, dense films.
The present invention provides a solution to these problems and includes a chemical surface deposition process. The process of the present invention involves the preparation of a liquid coating composition which comprises at least one Group IIB ionic species, at least one Group VIA ionic species, and a complexing agent capable of causing the Group IIB ionic species and the Group VIA ionic species to combine. The liquid coating composition is applied onto a heated substrate surface, which substrate surface is at a temperature higher than the temperature of the liquid coating composition. Prior to application, the solution temperature is maintained at a low enough temperature to reduce or eliminate homogeneous nucleation in the bath. To obtain the desired heterogeneous nucleation on the substrate while minimizing such homogeneous nucleation in the bath, the solution temperature is kept at a lower temperature than the substrate. Application onto the heated substrate causes the Group IIB ionic species and the Group VIA ionic species to react on the substrate surface and form a solid reaction product film of the Group IIB ionic species and the Group VIA ionic species on the substrate. This process solves the problems discussed above by decreasing the formation of particulates formed by homogeneous reactions in bath, dramatically increasing the utilization of Group IIB species (from about 1% to almost 100%), and forming dense, adherent films for thin film solar cells.
SUMMARY OF THE INVENTION
The invention provides a chemical surface deposition process for forming a film on a substrate which comprises:
a) forming a liquid coating composition which comprises at least one Group IIB ionic species, at least one Group VIA ionic species, and a complexing agent capable of causing the Group IIB ionic species and the Group VIA ionic species to combine;
b) applying the liquid coating composition onto a heated substrate surface, which substrate surface is at a temperature higher than the temperature of the liquid coating composition; and
c) causing the Group IIB ionic species and the Group VIA ionic species to react on the heated substrate surface under conditions sufficient to form a solid reaction product film comprising a reduced form of the Group IIB ionic species and the Group VIA ionic species on the substrate surface.
The invention also provides a process for forming a solar cell which comprises:
a) forming a liquid coating composition which comprises at least one Group IIB ionic species, at least one Group VIA ionic species, and a complexing agent capable of causing the Group IIB ionic species and the Group VIA ionic species to combine;
b) applying the liquid coating composition onto a heated substrate surface, which substrate surface is at a temperature higher than the temperature of the liquid coating composition;
c) causing the Group IIB ionic species and the Group VIA ionic species to react on the heated substrate surface under conditions sufficient to form a solid reaction product film comprising a reduced form of the Group IIB ionic species and the Group VIA ionic species on the substrate surface;
d) removing any excess liquid coating composition from the substrate;
e) rinsing the film with water; and
f) drying the film.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a flow chart of the process of the present invention.
FIG. 2 shows a schematic side-view of the present invention being carried out on a surface.
FIG. 3 shows a current-voltage (J-V) curve of the device formed according to Example 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The first step of the inventive process involves forming a liquid coating composition as indicated in FIGS. 1 and 2. According to the invention, the liquid coating composition comprises at least one Group IIB ionic species, at least one Group VIA ionic species, and a complexing agent.
The Group IIB ionic species comprises cadmium, mercury, zinc, or combinations thereof. Group IIB ionic species is preferably obtained from an aqueous solution of cadmium, mercury or zinc sulfate, acetate, bromide, fluoride, chloride, iodide, hydroxide, nitrate, oxalate, citrate, phosphate, tungstate, hydrates or combinations thereof. Preferably, the Group IIB ionic species component is present in the overall liquid coating composition at a concentration of from about 0.1 millimol to about 10 millimol per liter of the overall composition , more preferably from about 0.5 millimol to about 5 millimol per liter of the overall composition, and most preferably from about 1 millimol to about 2 millimol per liter of the overall composition.
The Group VIA ionic species comprises oxygen, sulfur, selenium, tellurium, polonium, or combinations thereof. The Group VIA ionic species is preferably obtained from an aqueous solution of oxides, halides, sulfates, nitrates, or ureates of the Group VIA species. Preferably, the Group VIA ionic species component is present in the overall liquid coating composition at a concentration of from about 0.05 mol to about 5 mol per liter of the overall composition, more preferably from about 0.1 mol to about 3 mol per liter of the overall composition, and most preferably from about 0.5 to about 1 mol per liter of the overall composition.
The complexing agent serves to control complexing of the Group IIB species, and affects the pH of the liquid coating composition. The complexing agent is capable of causing the Group IIB ionic species and the Group VIA ionic species to combine, most preferably upon the application of sufficient heat to cause such combining. Suitable complexing agents nonexclusively include diethanolamine (DEA) and ethylene diamine tetra-acetic acid (EDTA), and nitrogen-hydride compounds such as ammonium hydroxide and hydrazine. In a preferred embodiment of this invention, the complexing agent comprises ammonium hydroxide. The complexing agent is preferably present in the overall liquid coating composition at a concentration of from about 0.1 mol to about 5 mol per liter of the overall composition, more preferably from about 0.5 mol to about 3 mol per liter of the overall composition, and most preferably from about 1 mol to about 2 mol per liter of the overall composition.
The liquid coating composition preferably further comprises a solvent such as water, preferably deionized water. In a most preferred embodiment of the invention, the liquid coating composition comprises an aqueous mixture of cadmium sulfate, thiourea, and ammonium hydroxide. The liquid coating composition may also optionally comprise one or more additives which nonexclusively include surface modification agents such as surfactants, pH modification agents, and the like, which are well known to those skilled in the art.
The liquid coating composition preferably has a pH of from about 9 to about 14, more preferably from about 10 to about 13 and most preferably from about 11 to about 12. The composition can be made up to 30 minutes prior to application before noticeable onset of homogeneous reaction. Preferably, the composition is made immediately prior to application.
Once formed, the liquid coating composition is applied onto a surface of a heated substrate. Prior to deposition, the substrate surface is heated to a temperature which preferably ranges from about 50° C. to about 100° C., more preferably from about 60° C. to about 80° C., and most preferably from about 75° C. to about 85° C. The substrate may be heated using any suitable means known in the art such as a heat plate, lamp, latent heat from prior processing steps, or the like. It is most preferable that liquid coating composition is maintained at a lower temperature than the substrate surface prior to deposition. This is to prevent the occurrence of homogeneous reactions in the bath, thus reducing particulate formation in the liquid coating composition. Prior to deposition, keeping the solution at low temperatures, from about 5° C. to about 25° C., ensures a reasonably long shelf life due to reduction of species evaporation and reduction of reaction rate leading to the onset of homogeneous nucleation in the solution. After the liquid is applied, it gains heat by conduction from the substrate surface. Once applied onto the heated substrate, the temperature of the liquid coating composition preferably ranges from about 5° C. to about 80° C., more preferably from about 40° C. to about 70° C., and most preferably from about 50° C. to about 60° C. The chemical reaction that occurs on the substrate is:
Cd(NH 3 ) 4 ++ +(NH 2 ) 2 CS+2OH − ←→CdS+4NH 3 +H 2 CN 2 +2H 2 O
with free energy of reactions of ΔG rxn (25° C.)=−20.7 kcal/mol and ΔG rxn (100° C.)=−24.4 kcal/mol.
The substrate preferably comprises any suitable material known in the art which is suitable as a semiconductor substrate or solar cell substrate. Preferred substrate materials nonexclusively include plastic, glass, ceramic, metal, amorphous semiconductor materials, crystalline semiconductor materials, polycrystalline semiconductor materials and the like, and combinations thereof. In one preferred embodiment, the substrate comprises glass. At least one surface of the substrate preferably comprises a layer of a conductive material, such as a metal or a transparent conductive oxide (TCO). Suitable metals nonexclusively include molybdenum, platinum, nickel, chromium, gold, titanium, vanadium, and combinations and alloys thereof. Suitable transparent conductive oxides nonexclusively include tin oxide, indium oxide, zinc oxide, gallium oxide, cadmium stannate, zinc stannate and combinations thereof. The conductive material layer may be applied to the surface of the substrate by any suitable method known in the art such as evaporating, spraying, spin-depositing, sputtering, chemical vapor depositing, and the like. The conductive material layer may optionally comprise a conductive grid. TCO-coated substrates are well known in the art, and are commercially available from Libbey-Owens Ford, of Toledo, Ohio, or TFD of Los Angeles, Calif. The surface of the substrate may also optionally comprise a layer of a semiconductor material such as a Group I-III-VI 2 , Group II-VI, Group II-V, Group III-V, or Group IV semiconductor material, and the like.
Application of the liquid coating composition may be performed using any suitable deposition method known to those skilled in the art, such as flowing or sparging from pipettes, flowing or sparging from rollers, spraying, spin-depositing and the like. The surface tension between the liquid coating composition and the heated substrate determines the maximum solution volume for adhering the composition to a given substrate material without the use of a containment barrier along the edges. The surface tension can be modified by the addition of a wetting agent to the solution, such as glycerine. Depending on such surface tension, application of the liquid onto the substrate may optionally be conducted upside down. Addition of surface modification agents as described above may change the limiting volume that adheres to the substrate. Furthermore, a containment frame may be used to increase the total volume of applied solution.
Once the liquid coating composition is applied, heat flows from the substrate to the liquid, causing a reaction between the Group IIB ionic species and the Group VIA ionic species. This results in the formation of a solid reaction product film on the substrate surface. The reaction is allowed to proceed for a predetermined time, preferably ranging from about 1 to about 10 minutes. Any excess liquid coating composition which remains on the substrate may be discarded. It is important to not let the sample dry during reaction, in order to prevent non-uniformities and inclusions of secondary products in and on the film. The resulting film may optionally be rinsed with water and dried using any suitable method known in the art such as by baking or drying under a forced argon stream.
The solid reaction product film comprises a material which comprises a reduced form of the Group IIB ionic species and the Group VIA ionic species of the liquid coating composition. The film preferably comprises at least one material selected from the group consisting of cadmium sulfide, zinc sulfide, mercury sulfide, cadmium telluride, zinc telluride, mercury telluride, cadmium selenide, zinc selenide, mercury selenide, cadmium oxide, zinc oxide, and mercury oxide and combinations and alloys thereof. Most preferably, the film comprises cadmium sulfide.
The film optionally further comprises at least one additional species to provide alloy compounds or to provide a dopant for the semiconductor. Suitable additional species for alloy formation nonexclusively include magnesium, calcium, strontium, barium, and combinations thereof. Suitable additional species for doping nonexclusively include Group III and Group V components such as boron, aluminum, indium, gallium, thallium, nitrogen, phosphorous, arsenic, antimony, bismuth, and combinations thereof. The additional species may be incorporated into the film by the inclusion of an ionic species component of the additional species in the liquid coating composition at a concentration of from about 0.1 millimol to about 10 millimol per liter of the overall composition, more preferably from about 0.5 millimol to about 5 millimol per liter of the overall composition, and most preferably from about 1 millimol to about 2 millimol per liter of the overall composition. In the case of dopant species, lower ionic species concentrations are preferred and can be controlled in the present invention by ionic concentration in the solution or by the addition of complexing agents such as tetraethylamine (TEA) or ethylene diamine tetra-acetic acid (EDTA).
The film's thickness preferably ranges from about 100 Å to about 1000 Å, more preferably from about 200 Å to about 800 Å, and most preferably from about 300 Å to about 500 Å. The thickness of the film is dependent on the concentration of the Group IIB species in the solution, since the formation of the film preferably stops when the Group IIB species is completely utilized. Furthermore, a containment frame, Group IIB and complexing agent species replenishment, or multiple applications may be used to increase the thickness. In a preferred embodiment of the present invention, multiple applications of the inventive process, which enable the formation of additional film layers on the solid reaction product film, yield an overall film thickness increase which is linearly proportional to the number of coatings. The film's thickness may be measured using any suitable method known in the art such as optical absorption and step profilometry.
The film's grain size, morphology, and atomic smoothness are influenced by the deposition conditions. In a preferred embodiment of the invention, a single coating yielded CdS films of about 400 Å thick, with dense, conformal film coverage, and low area densities of adherent particulates, less than about 1×10 5 particulates per square centimeter of area. By comparison, a film deposited by the conventional art with the same thickness yielded greater than 1×10 8 particulates per square centimeter, consisting of homogeneously nucleated CdS and reaction by-products. The film's grain size, morphology, and atomic smoothness may be determined using any suitable method known in the art, such as by atomic force microscopy (AFM) or scanning electron microscopy (SEM)
The films formed according to the present invention exhibit low particulate density and high utilization of the Group IIB species. Such films are preferably used in forming window layers for thin film solar cells, but may have other useful applications in the art.
The following non-limiting examples serve to illustrate the invention. It will be appreciated that variations in proportions and alternatives in elements of the components of the invention will be apparent to those skilled in the art and are within the scope of the present invention.
EXAMPLE 1
CdS Thin-Film Formation
Stock aqueous solutions of 0.015 M cadmium sulfate, CdSO 4 , 1.5 M thiourea, CS(NH 2 ) 2 , and 14.28 M ammonium hydroxide, NH 4 OH, were placed in titrating burets for volumetric dispensation.
The following quantities of the solutions were dispensed into a mixing beaker with deionized water to form the working solution, at a temperature of 25° C. The volumetric proportions were:
2.2 ml CdSO 4
2.2 ml CS(NH 2 ) 2
2.8 ml NH 4 OH
15 ml H 2 O
Several indium tin oxide coated glass substrates were placed under a glass cover on a heated plate at temperatures of 55° C., 65° C., 75° C., 85° C., and 95° C., and allowed to heat for 10 minutes prior to application of the solution. The glass covers were removed, 0.7 ml per square inch of working solution was applied to the surface of each substrate, and timing clocks were started. At the end of the prescribed reaction times, ranging from 2-6 minutes, residual solution was transferred from each sample surface to a waste beaker. The coated substrates were rinsed in flowing de-ionized water and dried under a forced argon gas stream. To avoid incorporation of non-CdS phases, samples were rinsed immediately after the CdS reaction appeared to be completed. The time for this completion is referred to hereafter as the “reaction time”. This process resulted in ultra-thin, 100-500 Å, CdS films with high utilization of Cd species.
Reaction Time versus Reaction Temperature:
The time to complete the reaction varied with temperature for fixed total quantity of solution is shown in Table 1.
TABLE 1
Reaction time.
Reaction
Saturation
Temp.
Time
(° C.)
(min)
55
6
65
5
75
3
85
2
95
2
Thickness versus Cadmium Concentration and Reaction Temperature:
Thickness was determined by optical absorption and step profilometry. Using the reaction times shown in Table 1, films were deposited at different temperatures and Cd species concentration as shown in Table 2, thickness increased with temperature for fixed Cd concentration. At fixed temperature, such as 75° C., thickness increased with total Cd concentration until about 3 mMol, at which concentration, the obtained film thickness saturated. This was due to loss of ammonia species and stalling of the reaction as the applied solution heated. The maximum film thickness achieved for a single coating was about 500 Å, obtained at about 3 mMol and about 85° C. In a separate experiment performed on similar substrates at about 80° C., it was found that multiple coatings resulted in a thickness increase which is linearly proportional to the number of coatings.
TABLE 2
Thickness (Å)
Temp
[Cd] (mMol)
(° C.)
1.5
2.0
3.0
4.0
5.0
55
70
65
160
380
75
225
305
420
395
430
85
230
500
415
95
235
305
Cd Utilization versus Concentration and Reaction Temperature: Utilization of Cd species was calculated by mass balance from applied solution to thickness of deposited CdS film and is shown in Table 3. Cd species utilization increased with reaction temperature and was >80% for cadmium ion concentrations from about 1.5 to about 3 mMol. Thus, high utilization can be obtained for film thicknesses from about 200 to about 500 Å.
TABLE 3
Utilization of Cd species (%)
Temp
[Cd] (mMol)
(° C.)
1.5
2.0
3.0
4.0
5.0
55
28
65
65
56
75
90
85
84
58
51
85
92
100
60
95
94
45
EXAMPLE 2
CdTe Solar Cell Formation
A device was fabricated in superstrate configuration using a single chemical surface deposited (CSD) CdS coating applied to a glass/TCO/HRT (High Resistance Transparent layer) structure consisting of Corning 7059 glass/indium tin oxide/indium oxide. The CdS film was deposited by CSD for 3 min at 80° C. using the solution described in Example 1. A 4 micron thick CdTe absorber layer was deposited by evaporation at 340° C. The CdTe/CdS/HRT/TCO/glass structure was annealed at 600° C. in argon for 10 minutes and then treated in CdCl 2 :O 2 :Ar vapor at 400° C. for 20 minutes. Ohmic contact was formed by depositing Cu 2 Te followed by application of a conductive graphite ink.
Current-voltage (J-V) parameters are summarized in Table 4. The term “Voc” represents open circuit voltage; “Jsc” represents short circuit current; “FF” represents fill factor; and “Eff” represents efficiency (at AM 1.5 spectrum, 28° C.). FIG. 3 shows the J-V curve of the device.
TABLE 4
CdTe/CdS device J-V results.
Voc
Jsc
FF
Eff
Device
(mV)
(mA/cm 2 )
(%)
(%)
CdTe/CdS
790
26.0
68
13.8
The efficiency of this cell is among the highest obtained for a CdTe/CdS device made using evaporated CdTe. This data shows that such chemical surface deposited (CSD) CdS films yield high quality devices that are amenable to large area manufacturing of CdTe/CdS photovoltaic devices.
EXAMPLE 3
CuInGaSe 2 (“CIGS”) Solar Cell Formation
Devices were fabricated in substrate configuration using chemical surface deposited CdS on Cu(InGa)Se 2 films from a single deposition. The Cu(InGa)Se 2 was deposited by elemental evaporation at 550° C. and was 2 microns thick. The CdS coating was applied to three structures consisting of soda lime glass/molybdenum/Cu(InGa)Se 2 .
1. Sample 1 was the control sample with CdS deposited by the baseline CdS chemical bath process.
2. Sample 2 had the CdS deposited by chemical surface deposition using the following volumetric proportions: 2.8 ml of 0.015 Mol CdSO 4 +2.2 ml of 1.5 M CS(NH 2 ) 2 +2.2 ml of 14 M NH 4 OH+15 ml of H 2 O. The sample was pre-heated for 10 minutes to 80° C.
3. Sample 3 had the CdS deposited by chemical surface deposition with two coats, 3 minutes each of the same solution as in Sample 2.
Solar cell devices were completed with the sputter deposition of an Al-doped ZnO layer which was 0.5 μm thick and had sheet resistance of 20 Ω/square, followed by a Ni/al collector grid. Individual cells with total area 0.47 cm 2 were delineated by mechanical scribing.
Current-voltage (J-V) parameters are summarized in Table 5. Sample 3 had comparable Voc and FF to the control sample but lower Jsc. With efficiency greater than about 13% these results demonstrate that the chemical surface deposition of CdS can be used on Cu(InGa)Se 2 .
TABLE 5
Cu(InGa)Se2/CdS device results
CdS
Voc
Jsc
FF
Eff
Sample #
Deposition
(Volts)
(mA/cm 2 )
(%)
(%)
1
control:chemical
0.63
32.3
75.6
15.4
bath deposition
2
single layer chemical
0.63
29.6
64.8
12.2
surface deposition
3
double layer chemical
0.62
28.4
75.1
13.2
surface deposition
The examples show that the process taught by the present invention results in the formation of high quality, ultra-thin films with high Group IIB utilization that are amenable to large area manufacturing of photovoltaic solar cell devices.
While the present invention has been particularly shown and described with reference to preferred embodiments, it will be readily appreciated by those of ordinary skill in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. It is intended that the claims be interpreted to cover the disclosed embodiment, those alternatives which have been discussed above and all equivalents thereto.
|
A chemical surface deposition process for forming an ultra-thin semiconducting film of Group IIB-VIA compounds onto a substrate. This process eliminates particulates formed by homogeneous reactions in bath, dramatically increases the utilization of Group IIB species, and results in the formation of a dense, adherent film for thin film solar cells. The process involves applying a pre-mixed liquid coating composition containing Group IIB and Group VIA ionic species onto a preheated substrate. Heat from the substrate causes a heterogeneous reaction between the Group IIB and VIA ionic species of the liquid coating composition, thus forming a solid reaction product film on the substrate surface.
| 8
|
PRIOR APPLICATION
This is a continuation-in-part application of U.S. patent application Ser. No. 08/908,285, filed Aug. 7, 1997.
TECHNICAL FIELD
The present invention relates to a novel method for producing pulp, preferably sulphate cellulose, with the aid of a continuous cooking process.
BACKGROUND INFORMATION AND SUMMARY OF THE INVENTION
Environmental demands has forced our industry to develop improved cooking and bleaching methods. One recent breakthrough within the field of cooking is ITC™, which was developed in 1992-1993. ITC™ is described in WO-9411566, which shows that very good results concerning the pulp quality may be achieved. ITC™ is mainly based on using almost the same temperature (relatively low temperature compared to the prior art) in all cooking zones in combination with moderate alkaline levels. The ITC™-concept does not merely relate to the equalization of temperatures between different cooking zones, but a considerable contribution of the ITC™-concept relates to enabling an equalized alkaline profile also in the lower part of the counter-current cooking zone.
Moreover, it is known that impregnation with the aid of black liquor can improve the strength properties of the fibers in the pulp produced. The aim of the impregnation is, in the first place, to thoroughly soak each chip so that it becomes susceptible, by penetration and diffusion, to the active cooking chemicals which, in the context of sulphate cellulose, principally consist of sodium hydroxide and sodium sulphide.
If, as is customary according to the prior art, a large proportion of the white liquor is supplied in connection with the impregnation, there will exist no distinct border between impregnation and cooking. This leads to difficulties in optimizing the conditions in the transfer zone between impregnation and cooking.
Now it has been found that surprisingly good results can be achieved when:
1. Keeping a low temperature but a high alkali content in the beginning of a concurrent cooking zone of the digester;
2. Withdrawing a substantial part of a highly alkaline spent liquor that has passed through at least the concurrent cooking zone; and
3. Supplying a substantial portion of the withdrawn spent liquor that has a relatively high amount of rest-alkali, to a point that is adjacent the beginning of an impregnation zone.
This leads to a reduced H-factor demand, reduced consumption of cooking chemicals and better heat-economy. Additionally, the novel method leads to production of pulp that has a high quality and a very good bleachability, which means that bleach chemicals and methods can be chosen with a wider variety than before for reaching the desired quality targets (brightness, yield, tear-strength, viscosity, etc.) of the finally bleached pulp.
Furthermore, we have found that these good results can also be achieved when moving in a direction opposite the general understanding of the ITC™-teaching, in connection with digesters having a counter-current cooking zone. Instead of trying to maintain almost the same temperature levels in the different cooking zones, we have found that when using a digester that has both a concurrent and a counter-current cooking zone, big advantages may be gained if the following basic steps are used:
1. Keeping a low temperature but a high alkali content in the concurrent zone of the digester;
2. Keeping a higher temperature but a lower alkali content in the counter-current zone;
3. Withdrawing a substantial part of the highly alkaline spent liquor that has passed through at least one digesting zone; and
4. Preferably supplying almost all of the withdrawn spent liquor, that has a relatively high amount rest-alkali, to a position that is adjacent the beginning of the impregnation zone.
Also, in connection with digesters of the one-vessel type (without a separate impregnation vessel), surprisingly good results are achieved when the basic principles of the invention are used. The good results also apply to digesters having no counter-current zone and to overloaded digesters that cannot be provided with a sufficient supply of wash liquor to enable a sufficient up-flow for counter-current cooking.
Moreover, preliminary results indicate that the preferred manner of using the invention may be somewhat modified also in other respects but still achieving very good result, e.g., by excluding the counter-current cooking zone. Additionally, expensive equipment might be eliminated, e.g., strainers in the impregnation vessel, hanging central pipes, etc., making installations much easier and considerably less expensive.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic flow diagram of an embodiment of a digester system according to the basic principles of the present invention;
FIG. 2 is a cross-sectional view of a preferred first embodiment of a top separator according to the present invention;
FIG. 3 is a schematic flow diagram of a preferred second embodiment of a digester system according to the present invention;
FIG. 4 is a cross-sectional view of a preferred second embodiment of a top separator to be used in an impregnation vessel and/or hydraulic digester according to the present invention;
FIG. 5 is a cross-sectional view of a preferred third embodiment of a top separator to be used in an impregnation vessel and/or hydraulic digester according to the present invention;
FIG. 6 is a cross-sectional view of a preferred fourth embodiment of a top separator to be used in an impregnation vessel and/or hydraulic digester according to the present invention; and
FIG. 7 is a top view along line 6--6 of the top separator shown in FIG. 6.
FIG. 8 shows test data related to peroxide consumption and brightness for the present method compared to a conventional process;
FIG. 9 shows test data related to tensile index and tear index for unbleached pulp according to the present method compared to a conventional process;
FIG. 10 shows test data related to tensile index and tear index for bleached pulp according to the present method compared to a conventional process;
FIG. 11 shows test data related to Cl charge and brightness for the present method compared to a conventional process;
FIG. 12 is a schematic flow diagram of a preferred alternative embodiment of a two vessel cooking system according to the present invention; and
FIG. 13 is a schematic flow diagram of a preferred alternative embodiment of a single vessel cooking system according to the present invention.
DETAILED DESCRIPTION
FIG. 1 shows a preferred embodiment of a two vessel steam/liquid-phase digester for producing chemical pulp according to the invention. The main components of the digesting system consist of an impregnation vessel 1 and a steam/liquid-phase digester 6.
The impregnation vessel 1, which normally is totally liquid filled, possesses a feeding-in device 2 at the top, which feeding-in device may be a top separator with screw-feed device which feeds the chips in a downward direction at the same time as transport liquid is drawn off. The details of this top separator are described below. At the bottom, the impregnation vessel possesses a feeding-out device 3 comprising a bottom scraper. In addition, there is a conduit 17 in fluid communication with the impregnation vessel for adding hot black liquor. As best seen in FIG. 1, the black liquor is preferably supplied at the top of the impregnation vessel. In contrast to conventional black liquor impregnation vessels, no draw-off screen is located on the impregnation vessel. However, such draw-off may be provided, if so desired.
The chips are fed from a chip bin 20A, through a steaming vessel 20B and into a chip chute 20C. A feeding device, preferably a high-pressure feeder 19, feeds the chips via a conduit 18 to the top of the impregnation vessel 1. The feeder 19 is arranged in a known manner to the chute, and is connected to the necessary liquid circulations and replenishment.
A conduit 21 for transporting chips extends from the bottom of the impregnation vessel 1 up to a top portion 5 of the digester 6 having a steam space, wherein the liquid level is indicated by a dashed line. A supply line for supplying steam to the top portion 5 provides for heating of the steam space. As best seen in FIG. 2, the conduit 21 opens out at the bottom of a top separator 7 which may feed the chips by means of a screw in an upwardly moving direction. A screen of the separator is used to draw off the liquid D (which is then returned in the return line 15) together with which the chips are transported up to the top. At the upper edge of the screen (over which edge the chips tumble out), there is arranged an integrated annular ring 23. The annular ring 23 is connected to a conduit 24 which (preferably via a heat-exchanger 13A) leads to a white-liquor container (not shown). As best seen in FIG. 1, a screen girdle section 8 is arranged in conjunction with a step-out approximately in the middle of the digester 6. Draw-off from this screen girdle section 8 can be conducted directly via the conduit 17 to the impregnation vessel 1. Preferably, however, the black liquor is drawn off via a conduit 28 to a first flash cyclone 9. The first flash cyclone may be in operative engagement with the heat exchanger 13A to provide steam to the heat exchanger. At the bottom 10 of the digester 6, there is a feeding-out device including one scraping element 22.
According to a preferred alternative, a "cold-blow" process is carried out so that the temperature of the pulp is cooled down at the bottom of the digester with the aid of relatively cold (preferably 70-80° C.) liquid (wash liquid) which is added by means of the scraping element 22 and/or other liquid-adding devices 25 (such as annular pipes) at the bottom of the digester, and then conducted upwards in counter-current. With the aim of being able to produce high-quality pulp having a low and equal kappa number, it is essential to distribute chemicals and heat evenly across the digester, so that all fibers in the column are treated under the same conditions.
This may be achieved by means of a lower circulation 11, 12, 13, 14, a so-called ITC™ circulation. This lower circulation consists of a screen girdle section 12 (in the shown embodiment consisting of three rows) which is arranged just above the lower liquid-addition point 22 and/or 25. In an overloaded digester, it is desirable to position the section 12 close to the washing liquid conduit 25 if there is no or only insubstantial counter-current flow in the zone below the screen girdle section 12. The draw-off from the screen girdle section 12, is recirculated (for displacing black liquor in counter-current to the draw-off screen 8) into the digester with the aid of a stand pipe 14 that extends from the bottom of the digester and opens out approximately on a level with the screen girdle section 12. A heat exchanger 13 for temperature regulation (increasing the temperature of the re-introduced liquid) and a pump are also located in the conduit 11 which connects the screen girdle 12 with the stand pipe 14.
The recirculation loop 11 may also be connected via a branch conduit 27 to the white liquor supply so that fresh alkali can be supplied and, in the form of counter-current cooking, further reducing the kappa number. The digester construction described is notable for the lack of a plurality of central pipes arranged from above and hanging downwards, as well as of feed pipes connected to them and of other necessary parts for the circulations.
A preferred installation according to the invention may function as follows. The chips are fed into the chip bin 20A, subsequently to the steaming vessel 20B and, thereafter, forwarded into the chute 20C. The high-pressure feeder 19 (which may be supplied with about 5% of the total amount of white liquor in order to lubricate the feeder 19), with the aid of which the chips are fed into the conduit 18 together with transport liquid. The slurry of chips and liquid that is fed to the top of the impregnation vessel 1 may have a temperature of about 110° C. to 120° C. on entry to the impregnation vessel 1 (excluding recirculated transport liquor).
In addition to the actual fibers in the wood, the latter also conveys its own moisture (the wood moisture), which normally constitutes about 50% of the original weight, to the impregnation vessel 1. Over and above this, some condensation is present from the steaming, i.e., at least a part of the steam (principally low-pressure steam) which was supplied to the steaming vessel 20B is cooled down to such a low level that it condenses and is then recovered as liquid together with the wood and the transport liquid.
At the top of the impregnation vessel 1, there is a screw feeder 2 that pushes chips from above and downwards into the impregnation vessel 1. Preferably, no liquid is recirculated within the impregnation vessel. Instead, spent liquor that has passed through the first flash tank 9 is supplied. If desired, however, such recirculation may be provided in the impregnation vessel.
The chips which are fed out from the bottom of the top screen 2 then move slowly downwards in a plug flow through the impregnation vessel 1 in a liquid/wood ratio between 2/1-10/1 preferably between 3/1-8/1, more preferred of about 4/1-6/1. Hot black liquor, which is drawn off from the first flash tank 9, is added, via the conduit 17, to the top of the impregnation vessel 1. The high temperature of the black liquor (100° C. to 160° C.), preferably exceeding 130° C., more preferred between 130° C. to 160° C., ensures rapid heating of the chips. In addition, the relatively high pH, exceeding pH 10, of the black liquor neutralizes acidic groups in the wood and also any acidic condensate accompanying the chips, thereby, i.e., counteracting the formation of encrustation, so-called scaling.
An additional advantage of the method is that the black liquor supplied into the impregnation vessel has a high content of rest alkali, (EA as NaOH), at least 13 g/l, preferably about or above 16 g/l and more preferred between 13 g/l to 30 g/l at the top of the impregnation vessel 1. This alkali mainly comes from the black liquor due to the high amount of alkali in the concurrent zone C of the digester. Furthermore, the strength properties of the fibers are positively affected by the impregnation because the high amount of sulphide. The major portion of black liquor is directly (or via one flash) fed to the impregnation vessel 1.
A minor amount of the black liquor may be used for transferring the chips from the HP-feeder to the inlet of the impregnation vessel. However, no amount, or only an insubstantial amount, of black liquor is directly transferred to the cooking zones.
The total supply of black liquor to the impregnation vessel exceeds 80% of the amount drawn off from the draw-off strainers 8, preferably more than 90% and optimally about 100% of the total flow, which normally is about 8 to 12 m 3 /ADT.
The chips, which have been thoroughly impregnated and partially delignified in the impregnation vessel, are then fed to the top of the digester 6 and conveyed into the upwardly-feeding top separator 7. The chips are thus fed upwards through the screen, meanwhile free transport liquid is withdrawn outwardly through the screen and finally the chips fall out over the edge of the screen down through the steam space. Before or during their free fall, the chips are drained with a cooking liquor which is supplied by the conduit 24 into the top separator 7. The white liquor is preferably heated by the heat exchanger 13A that preferably is supplied with heat steam from the flash tank 9.
The quantity of white liquor that is added at the top of the digester 6 depends on how much white liquor possibly is added else where, but the total amount corresponds to the quantity of white liquor that is required for achieving the desired delignification of the wood. Preferably, a major part of the white liquor is added here, i.e., more than 60%, which also improves the diffusion velocity, since it increases in relation to the concentration difference (chip-surrounding liquid). The thoroughly impregnated chips rapidly assimilate the active cooking chemicals by diffusion, since the concentration of alkali (EA as NaOH) is relatively high, at least 20 g/l, preferably between 30 g/l and 60 g/l and more preferred between about 45 g/l and 55 g/l.
The chips then move down into the concurrent cooking zone B and through the digester 6 at a relatively low cooking temperature, i.e., between about 130° C. to 160° C., preferably about 140° C. to 150° C. The major part of the delignification takes place in the concurrent cooking zone B.
The retention time in the concurrent cooking zone should be at least 20 minutes, preferably at least 30 minutes and more preferred at least 40 minutes. The liquid-wood ratio should be at least 2/1 and should be below 7/1, preferably in the range of 3/1 to 5.5/1, more preferred between 3.5/1 and 5/1. The liquid wood-ratio in the counter-current cooking zone C should be about the same as in the concurrent cooking zone B.
The cooking liquid mingled with released lignin, etc., is drawn off at the draw-off screen 8 into the conduit 28. As mentioned above, liquid is also supplied in the lower part of the digester which moves in a counter-current flow direction. It can be described as the pipe 14 displacing it from the wood upwards towards the draw-off screen 8. This results, consequently, in the delignification being prolonged in the digester 6.
The alkali content in the lowermost part of the counter-current cooking zone C should preferably be lower than in the beginning of the concurrent zone B, above 5 g/l, but below 40 g/l. Preferably less than 30 g/l and more preferred between 10 g/l to 20 g/l. In the preferred case, the aim is to have about the same temperature in all cooking zones but sometimes a temperature difference of about 10° C. between the cooking zones may be advantageous. Expediently, the lower circulation 11, 12, 13, 14 is charged with about 5% to 20%, preferably 10% to 15% of the total amount of white liquor. The temperature of the liquid which is recirculated via the stand pipe 14 that is regulated with the aid of a heat exchanger 13 so that the desired cooking temperature is obtained at the lowermost part of the counter-current cooking zone C.
In the preferred case, the cold-blow process is used so that the temperature of the pulp in the outlet conduit 26 is less than 100° C. Accordingly, washing liquid having a low temperature, preferably about 70° C. to 80° C., is added by using the scraping element and an outer annular conduit 25 arranged at the bottom of the digester 6. This liquid consequently displaces the boiling hot liquor in the pulp upwards in counter-current and thereby imparts a temperature to the remaining pulp which can be cold-blown, i.e., depressurized and disintegrated without any real loss of strength.
From tests made in lab-scale, we have found indications that it is desired to keep the alkaline level at above at least 2 g/l, preferably above 4 g/l, in the impregnation vessel 1 in connection with the black liquor, which would normally correspond to a pH of about 11. If not, it appears that dissolved lignin precipitate and even condensate.
In FIG. 2 there is shown a preferred embodiment of a separator to be used in connection with one of the embodiments of steam/liquid phase digester systems disclosed herein. It is often preferred to have an upwardly feeding top separator for a steam/liquid phase digester. The separator may comprise a screen basket 61 in which a rotatable screw feeder 62 is positioned. The screw feeder is fixedly attached to a shaft 63 which at its upper end is fixedly attached to a drive unit 64. The drive unit 64 is attached to a plate 65 which is attached to the digester shell 6.
Circumjacent the screen basket 61 there is arranged a liquid collecting space 67, which may be connected to the return pipe circulation 15. Above the liquid collecting space 67, also circumjacent the screen basket 61, there is arranged a liquid supply space or opening 23 which is connected to the supply line 24 that supplies white liquor. Between the outer peripheral wall 66 of the liquid collecting space 67 and the liquid supply space 23 respectively, and the digester shell 6 at the top, there exist an annular space 70 which opens up down into the upper part of the digester 6. The functioning of the top separator may be described as follows.
The thoroughly heated and impregnated chips are transferred by means of the supply line 21 into the bottom portion of the screen basket 61. Here the screw feeder 62 moves the chips upwardly at the same time as the transport liquid D is separated from the chips, by being withdrawn outwardly through the screen basket 61 and further out of the digester through return line 15. More and more liquid will be withdrawn from the chips during their transport within the screen basket 61. Eventually, the chips will reach the level of the supply space 23. Here the desired amount of cooking liquor, preferably white liquor, is added through the supply space 23, having a temperature and effective alkaline content in accordance with the invention.
In order to eliminate the risk of back flowing of the supplied liquid from the supply space 23 into the withdrawal space 67, a minor amount of free liquid (at least about 0.5 m 3 /ADT) should be left together with the chips, which free liquid will then be mixed with the supplied cooking liquor. Preferably, about one m3/ADT should be left together with the fiber material. Additionally, the white liquor should be provided at a point that is downstream of the flow of the suspension of the fiber material and the free liquid that is being fed through the screw member.
At the top of the screen basket 61, the chips and the cooking liquor may flow over the upper edge thereof and fall into the steam liquid space 70 and further on to the top of the chips pile within the digester, where the concurrent cooking zone (B) starts.
In FIG. 3, it is shown a preferred embodiment for applying the invention to a single vessel hydraulic digester 6. The same kind of basic equipment before and in connection with the HP-feeder as shown in FIG. 1 is used, which therefore is not described in detail. Withdrawal strainers 8 are arranged in the middle part of the digester 6. The lowermost part of the digester is in principle similar to the one shown in FIG. 1, with a supply line 25 for washing liquid and a blow line 26 for removing the digested pulp from the digester 6. A very short distance above the bottom of the digester 6, there is positioned a strainer arrangement 12 for withdrawing liquid which is heated and to which some white liquor, preferably about 10% of the total amount, is added before it is recirculated by means of a short stand pipe 39, which opens up at about the same level as the lowermost strainer girdle 12.
In the upper part of the digester there are arranged two further strainer sets 40, 41. The upper strainer 40 is arranged for withdrawing liquid which has passed the impregnation zone (A). Some of the withdrawn liquid D is taken out via a conduit 46 to a second flash tank 47. The other part of the withdrawn liquid is recirculated for re-introducing liquid withdrawn by means of a central pipe 42 which opens up at a level adjacent the strainer 40. Before the liquor withdrawn from the strainer 40 is re-introduced, white liquor can be added thereto by means of a supply-line 43 and thereafter the liquid is heated to the desired temperature by means of a heat exchanger 44.
The second strainer 41, which is positioned immediately below the upper strainer 40 but above the withdrawal strainer 8 is a also part of a re-circulation unit.
The liquor that is withdrawn from the strainer 41 is recirculated for re-introducing the liquor by means of a central pipe 52 which opens up at a level adjacent the strainer 41. Before the liquor withdrawn from the strainer 41 is re-introduced, the main portion of the white liquor is added thereto by means of a supply-line 53 and thereafter the liquid is heated to the desired temperature by means of a heat exchanger 54.
The digesting process within a digester shown in FIG. 3 may be described as follows. The slurry of chips and transport liquid is transferred, e.g., by means of high pressure feeder, within the feeding line 21 to the top of the digester where it is introduced into the top of a screen basket 35s (see FIG. 4) of the separator, wherein the major part of transport liquid is separated from the chips. Below the separator at supply devices 37s, an impregnation liquor E is supplied by means of the supply lines 38s. The supply devices 37s should be a sufficient distance from the separator to prevent any undesirable back-flowing from occurring. The impregnation liquor may be hot black liquor that is taken from the withdrawal screen 8 via a flash tank 9 by means of the supply conduit 38.
If all the desired liquor amount cannot be withdrawn via the conduit 46 (see FIG. 3) to the flash tank 47, there is provided for the possibility of also withdrawing liquor from the outlet of the first flash tank 9 via a conduit 45. A minor amount of the black liquor withdrawn from flash tank 9 may be used for transferring the chips from the HP-feeder via the conduit 21 to the inlet of the digester 6. This minor flow then has to be cooled in a cooler 80 before it is entered into the feeder. The two flows of black liquor are preferably used to regulate the temperature within the impregnation zone A. In the preferred embodiment, the temperature of the black liquor within the impregnation zone is over 100° C. Preferably, the temperature is between about 120° C. and about 140° C.
The amount of effective alkaline of the black liquor provided in the conduit 38 is relatively high, at least 13 g/l, preferably about 20 g/l, which provides for the impregnation zone (A) to be established without any substantial additional supply of white liquor at this position. The chips are then impregnated and heated when moving down towards the upper screen 40, where the spent liquor (D) is withdrawn and transferred by means of the conduit 46 to the flash tank 47.
The chips are heated and alkali is introduced by means of the above described cooking circulations 40, 42, 43, 44; and 41, 52, 53 and 54 in order to obtain the desired cooking conditions. In the preferred mode, the temperature at the beginning of the concurrent zone B is about 145° C. to 160° C. for soft wood and about 140° C. to 155° C. for hard wood and an alkaline content of about 30 g/l to 55 g/l. Thanks to the exothermic reaction of the chemicals the temperature is slightly further increased when the fiber material is moving downwardly in the concurrent cooking zone B.
Liquid having a relatively high content of effective alkaline is withdrawn at the strainers 8 positioned adjacent the middle section of the digester 6. The alkaline content of this withdrawn spent liquor E would normally exceed 15 g/l.
Also liquor from the counter-current zone C is withdrawn at this withdrawal strainer 8, since the liquor being introduced by means of the stand pipe 39 moves in counter-current upwardly through the concurrent cooking zone C finally reaching these strainers 8. A withdrawal strainer 12 is positioned close to the bottom, as shown in FIG. 3. In the counter-current zone C, the temperature is controlled by means of heating the liquid drawn from the lower withdrawal strainer 12, in a heat exchanger 51 before introducing it through the stand pipe 39. In the preferred case, also a minor amount, about 10% to 15% of the total amount, of white liquor is added to this recirculation line to achieve the desired alkali concentration in the counter-current cooking zone C.
The pulp is then cooled by means of washing liquid 25 that is supplied at the bottom of the digester 6. The washing liquid 25 moves in counter-current upwardly and subsequently is withdrawn at the strainer 12. The cooled finally digested pulp, is then taken out of the digester into the blow-line 26.
As already mentioned, pulp produced in this manner has a higher quality and better bleachability than pulp produced with known methods. In lab-scale tests, we have found that about 10 kg of active chlorine can be saved for reaching full brightness (about 90% ISO), compared to a conventionally cooked pulp.
In FIG. 4, there is shown a preferred second embodiment of a top separator intended for a hydraulic digester or an impregnation vessel according to the present invention. Only a part of the top of the digester 6s is shown. The slurred fiber material is transferred to the top of the digester by means of a transfer line 21s and enters an in-let space 30s of a screw-feeder 31s. The screw-feeder 31s is attached to a shaft 32s connected to a drive-unit 33s which is attached to a mounting-plate 34s at the top of the digester shell 6s. The drive-shaft 32s is rotated in a direction so as to force the screw to feed the fiber slurry in a downward direction.
A cylindrical screen-basket 35s surrounds the screw-feeder 31s. The screen-basket 35s is arranged within the digester shell 6s so as to form a liquid collecting space 36s between the digester shell and the outer surface of the screen-basket 35s. The liquid collecting space 36s, which preferably is annular, communicates with a conduit 17s for withdrawing liquid from the liquid collecting space 36s, which in turn is replenished by liquid from the slurry within the screen basket 35s. The major part of the free liquid within the slurry entering the screen basket is withdrawn into the liquid collecting space 36s, but a small portion of free liquid, at least about 0.5 m 3 /ADT should not be withdrawn from the slurry.
Below the outlet end of the screen basket 35s there is arranged a pair of liquid supply devices 37s, each preferably comprising an annular distribution ring which opens up into the chips pile for supply of liquid into the fiber material moving down into the digester 6s. The liquid supply devices 37s are replenished by means of lines 38s wherein a desired amount of liquid is supplied. If it is a two-vessel hydraulic digester system, the liquid supplied through the liquid supply devices 37s into a concurrent cooking zone B would be hot cooking liquor having a relatively high amount of effective alkaline, in order to provide for the possibility of establishing the concurrent cooking zone B having a desired cooking temperature and a desired content of effective alkaline.
FIG. 5 shows a preferred third embodiment of a separator to be used together with a hydraulic digester or an impregnation vessel 1 that is part of a digester system, such as the digester system shown in FIG. 1, where there is a need for a heat seal. The advantage of providing the heat seal adjacent the separator is to enable the injection of hot black liquor (above 100° C.) into the top of the vessel without risking to operate the high pressure feeder at too high of a temperature. The heat seal reduces or even eliminates the risk of any hot liquor being inadvertently conducted back to through the top separator and to the high pressure feeder which may damage the feeder. The separator may also be used in a single vessel hydraulic digester if required. Only a top portion of such an impregnation vessel 1 or a digester is shown. The non-impregnated slurred fiber material is transferred to the top of the impregnation vessel or the digester by means of the transfer line 21 and enters an inlet space 30 of a screw-feeder 31. The screw-feeder 31 is attached to a shaft 32 connected to a drive-unit 33 which is attached to a mounting-plate 34 at the top of the vessel shell 1. The drive-shaft 32 is rotated in a direction so as to force the screw to feed the chips and the transport fluid in a downward direction.
A cylindrical screen-basket 35 surrounds the screw-feeder 31. The screen-basket 35 is arranged within the vessel shell 1 so as to define a liquid collecting space 36 between the digester shell and the outer surface of the screen-basket 35. The liquid collecting space 36, which preferably is annular, communicates with a conduit 15 for withdrawing liquid from the liquid collecting space 36, which in turn is replenished by liquid from the slurry within the screen basket 35. The major part of the free liquid within the slurry entering the screen basket is withdrawn into the liquid collecting space 36, but a small portion of free liquid, at least about 0.5 m 3 /ADT should not be withdrawn from the slurry.
A set of level sensors 60 is positioned along a side wall of the vessel 1 to sense the level in the vessel. The level sensors are disposed below the screw-feeder 31 but above the pair of liquid supply devices 37. A top section 62 of the vessel 1 has a diameter (d) that is less than a diameter (D) of the vessel at a mid-portion and bottom portion thereof. The diameter (d) is small to reduce or even avoid any substantial heat transfer to the return line leading to the high pressure feeder so that the maximum temperature is slightly below the boiling temperature of the liquid in the chip chute. The boiling temperature is dependent on the pressure in the chip chute. In this way, a heat lock zone 64 is formed between the liquid supply devices 37 (for supplying hot black liquor) and the liquid collecting space 36.
The liquid supply devices 37 preferably comprise an annular distribution ring 38 which has a number of supply conduits disposed between the ring 38 and the vessel 1. The supply conduits 37 open up into the chips pile for supplying liquid into the fiber material moving down into the vessel 1. The annular distribution ring 38 is replenished by means of the conduit 24 wherein a desired amount of liquid is supplied. The liquid supplied through the liquid supply device 37 and annular ring 38 may be hot black liquor having a relatively high amount of effective alkaline, in order to provide for the possibility of establishing a concurrent impregnation zone (A) having a desired temperature of about 120° C. to 145° C., and a desired content of effective alkaline, of about 10-20 g/l.
FIGS. 6-7 illustrate a preferred fourth embodiment of a top separator of the present invention. Similar to the earlier described embodiments of the separators, this alternative embodiment has a screw feeder that feeds the fiber material and the transport liquid downwardly through the separator, only some of the most important features of this embodiment are described herein.
The separator 200 is mounted in a vessel 206 having cupped gables and the separator 200 has an extension portion 202 that extends downwardly from the separator 200. A plurality of separation plates 204 extend from the separator 200 to an inner wall of a vessel 206. The extension portion 202 reduces the risk of any undesirable back flow of the black liquor into the separator 200. A set of supply devices 237 are disposed between the separation plates 204. The supply devices 237 each have a downwardly bent conduit section to further reduce the risk of a undesirable back-flow and to permit the black liquor to flow in a downward direction that is concurrent with a flow of the fiber material that has been fed through the top separator 200. Similar to the embodiment illustrated in FIG. 5, a set of level sensors 208 are disposed at the inner wall of the vessel 206. However, the level sensors 208 are disposed below the supply devices 237 as opposed to above the supply devices as shown in FIG. 5.
A major advantage of the shown separation devices is that they provide for establishing a distinguished change of zones (they enable almost a total exchange of free liquid at this point), which means that the desired conditions in the beginning of the concurrent zone can easily be established.
FIG. 8 shows results from a TCF bleaching using the cooking process, illustrated as the new concept, of the present invention compared to a conventional ITC reference cooking process. The present invention provides a TCF-bleached pulp having extremely good bleachability and a higher brightness is achieved compared to the conventional process for the same amount of peroxide consumption, and also a higher brightness ceiling is obtained.
FIG. 9 shows the tear index relative to the tensile index. The new concept of the present invention provides a higher tear index relative to the tensile strength compared to a conventional ITC cooking process.
Similarly, FIG. 10 illustrates test data for the present invention, illustrated as the new concept, compared to a conventional reference ITC-digester. The present invention exhibits better tensile index compared to the conventional method for bleached pulp.
FIG. 11 shows the brightness level by using the present invention, illustrated as the new concept, compared to a conventionally cooked pulp using the ITC process. As is evident, the cooking process of the present invention results in a pulp that is much easier to bleach compared to the conventional cooking process, i.e. the present invention requires less chemicals at a given brightness. The new cooking concept of the present invention also provides a higher brightness ceiling.
When cooking in mill scale according to the new concept of the present invention, the following significant advantages are gained in comparison to a conventional ITC-cooking.
When cooking softwood:
Increased tear strength by 10%;
Unchanged beatability;
Improved viscosity by 40 units at kappa number 22;
Increased brightness of unbleached pulp by 2% ISO units;
Increased brightness ceiling of bleached pulp by 0.5% to 1% ISO unit;
Lowered H 2 O 2 consumption by 15% to 20%;
Reduced knot content by 60%;
Reduced shive content by 55%;
Reduced MP-steam consumption in digester by 10% to 15%.
When cooking hardwood:
Increased tensile index at 500 PFI-revolutions by 8%;
Increased tensile stiffness at 500 PFI-revolution by 8%;
Improved viscosity by 50 units at kappa number 15;
Increased brightness ceiling;
Lowered H 2 O 2 consumption by 15%;
Reduced knot content by 55%;
Reduced shive content by 50%;
Reduced alkali charge by 10%.
FIG. 12 shows a way of running the process of the present invention in connection with an overloaded two vessel steam/liquid digester. Due to the overload (normally more than 30 ADMT pulp/hour and m 2 in the final cooking zone C) such a digester 6 normally has difficulties to obtain a sufficient up-flow in the so called counter-current cooking zone. The final cooking zone C will therefore be in form of a concurrent final cooking zone C. To run according to the invention this requires a withdrawal strainer 12 positioned close to the bottom of the digester 6 and the retrofitting of a withdrawal line 99 that extends from a conduit 11 that is connected to the strainer to a flash tank 16 to be further conveyed to a recovery unit. FIG. 12 is almost identical to FIG. 1 (no retro-fit), except for the withdrawal line 99 which transfers liquor withdrawn from the lowermost screen 12 to a recovery unit. However, a major (more than 50%) portion of the liquor that is conducted to the recovery unit is still taken from the return line 15 via a connecting conduit 29 that extends to the flash tank 16. The process preferably leads to a higher wood/liquid ratio in the impregnation zone A of the impregnation vessel 1 than in the con-current cooking zone B of the digester 6 that may have a higher wood/liquid ratio than the final cooking zone C, i.e. w/l of zone A>w/l of zone B>w/l of zone C. In order to achieve a cold blow (below 100° C. in the blow line 26) it may be necessary to add a sufficient amount of cold wash liquor conducted in a conduit 25 at a point that is adjacent the bottom of the digester 6. The wash liquor is normally supplied by means of nozzles, and sometimes preferably also through the scraper 22 disposed at the bottom of the digester 6. The wash liquor in the conduit 25 may partly flow upwards and displace the hot cooking liquor in the pulp that is moving downwardly below the screen 12, and partly go out in the blowline 26 together with the pulp. If desired, some wash liquor may be added by means of the central pipe 14 disposed inside the digester 6 in order to radially displace hot cooking liquor. Alternatively, the latter may be achieved by means of a stand pipe that extends upwardly from the bottom of the digester 6. This method may also be used in connection with digesters that are not overloaded but that have problems with keeping a sufficient up-flow (normally recommended to be at least 1.5 m 3 /ADMT pulp dilution factor for counter current cooking) in the final cooking stage.
FIG. 13 shows a way of running the process in connection with an overloaded single vessel hydraulic digester. FIG. 13 is almost identical to FIG. 3 (no retro-fit), except for a withdrawal line 99 that transfers liquor withdrawn from the lowermost screen 12 to recovery. More particularly, the line 99 has one end connected to a conduit 101 and an opposite end connected to a flash tank 47. The flash tank 47 has a conduit 103 that leads to a recovery unit. As mentioned above, in an overloaded digester, the upward flow in the counter-current zone C is often insignificant to the downward flow in the concurrent zone (B) of the overloaded digester. The method of operating the digester in the lowermost zone (C) of FIG. 13 is virtually identical to the method described in connection with FIG. 12.
With regard to the temperatures used when running overloaded digesters as described in FIGS. 12-13, it should be noted that the temperatures in the cooking zones are related to the retention time of the cooking zones that in turn corresponds to the H-factor. As already mentioned, the new concept of the present invention leads to a lower H-factor demand compared to conventional methods and digesters. However, since an overloaded digester has a production rate exceeding its nominal dimensions, the retention time will be reduced. If the same temperature would be maintained in the cooking zones as calculated for its nominal production this would lead to a reduced H-factor which may result in an insufficient Kappa reduction. Accordingly in connection with overloaded digesters it may be preferred or even necessary to increase the temperatures in the cooking zones to achieve the desired kappa reduction. The increase of the temperatures may be as high as 15° C., preferably about 10° C., compared to the nominal temperature according to the new concept of the present invention.
While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the spirit and scope of the following claims.
|
This invention relates to a new and improved way of continuously cooking fiber material in an over loaded digester, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimize chemical consumption and heat economy and, at the same time, to achieve very good pulp properties.
| 3
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to spill guards and, more specifically, to a paint bucket spill guard that is installed on a paint bucket for the purpose of preventing paint from collecting in the paint can rim channel. The conical shape of the device provides a large opening for dispensing the paint from the paint can as well as pouring the paint back into the paint can as from a roller tray.
2. Description of the Prior Art
Normally, when applying paint by brush, the tendency is to extract excess paint by wiping the brush on the paint can interior rim. This often causes an undesirable accumulation in the paint can rim channel, interfering with the hermetic seal of the paint can lid, rendering long term storage useless. Ordinary funnels, spouts and caps do not address this problem. What is needed is a device that provides the pouring functions of a funnel, that also has the capability to isolate the paint can rim channel from the paint or other liquid.
SUMMARY OF THE PRESENT INVENTION
A primary object of the present invention is to provide a paint bucket spill guard that is installed on a paint bucket for the purpose of preventing paint from collecting in the paint can rim channel.
Another object of the present invention is to provide a conical shaped device providing a larger opening for dispensing the paint from the paint can as well as pouring the paint back into the paint can as from a roller tray.
Yet another object of the present invention is to provide two lifting tabs aligned with the uppermost horizontal surface, positioned roughly 180 degrees apart.
Still yet another object of the present invention is to provide tabs that serve to facilitate positioning the device atop a paint can and also to allow convenient removal without having to come in contact with the surfaces that may contain wet paint.
Another object of the present invention is to provide a paint bucket spill guard that provides an inner work surface.
Yet another object of the present invention is to provide a paint bucket spill guard conveniently sized to overlap the paint can rim channel structure so as to further prevent possibility of contamination.
Additional objects of the present invention will appear as the description proceeds.
The present invention overcomes the shortcomings of the prior art by providing a paint bucket spill guard that is installed on a paint bucket for the purpose of preventing paint from collecting in the paint can rim channel. Also, the conical shape of the device provides a larger opening for dispensing the paint from the paint can as well as pouring the paint back into the paint can as from a roller tray. Also, having two lifting tabs aligned with the uppermost horizontal surface positioned roughly 180 degrees apart that serves to facilitate positioning of the device atop a paint can, and also allows convenient removal without having to come in contact with the surfaces that may contain wet paint.
There is provided a device for guiding a liquid into a liquid storage can having a top and a top opening, the top having a rim about the opening, the rim having an upwardly facing shoulder and an upwardly facing channel, the device comprising: a wall portion forming an open enclosure, the wall portion having a bottom end, the wall portion enclosure opening through the bottom end; a flange portion on the wall portion bottom end, the flange portion having a downwardly facing shoulder and a downwardly facing engaging member, the engaging member being received by the liquid storage can rim channel about the rim circumference, such that the downwardly facing shoulder bears upon the rim shoulder and, when the liquid is poured into the device, the wall portion directs the liquid through the wall portion enclosure opening, and the flange portion isolates the liquid storage can rim channel from the liquid.
In one embodiment, the liquid storage can rim channel further comprises an inner lip and the flange portion further comprises a downwardly facing inner shoulder, the inner shoulder being inwardly disposed from the engaging member, such that the inner shoulder bears upon the rim channel inner lip when the engaging member is received by the rim channel.
In one embodiment, the liquid storage can rim channel further comprises an inner lip and the engaging member further comprises an inner side, the inner side being tapered such that the engaging member inner side bears upon the rim channel inner lip when the engaging member is received by the rim channel, the joinder of the inner side and inner lip isolating the liquid storage can rim channel from the liquid.
In one embodiment, the liquid storage can is a paint can, and the liquid is paint.
In one embodiment, the engaging member is closely received by the liquid storage can rim channel.
In one embodiment, the wall portion has at least one grasping extension.
In one embodiment, the wall portion has a pair of grasping extensions.
In one embodiment, the wall portion is conical.
There is provided, in combination with a liquid storage can having a top and a top opening, the top having a rim about the opening, the rim having an upwardly facing shoulder and an upwardly facing channel, a device for guiding the liquid into the liquid storage can top opening, the device comprising: a wall portion forming an open enclosure, the wall portion having a bottom end, the wall portion enclosure opening through the bottom end; a flange portion on the wall portion bottom end, the flange portion having a downwardly facing shoulder and a downwardly facing engaging member, the engaging member being received by the liquid storage can rim channel about the rim circumference, such that the downwardly facing shoulder bears upon the rim shoulder and, when the liquid is poured into the device, the wall portion directs the liquid through the wall portion enclosure opening, and the flange portion isolates the liquid storage can rim channel from the liquid.
A device is provided for guiding a liquid into a liquid storage can having a top and a top opening, the top having a rim about the opening, the rim having an upwardly facing shoulder and an upwardly facing channel, the device comprising: a wall portion forming an open enclosure, the wall portion having a bottom end, the wall portion enclosure opening through the bottom end; flange means for positioning the wall portion bottom end in the rim channel such that the rim channel is isolated from liquid being poured through the wall portion enclosure opening into the liquid storage can.
A device is provided for guiding liquid paint into a paint can having a top and a top opening, the top having a rim about the opening, the rim having an upwardly facing shoulder, an upwardly facing channel, and an inner lip, the device comprising: a wall portion forming an open, conical enclosure, the wall portion having at least two grasping extensions and a bottom end, the wall portion enclosure opening through the bottom end; a flange portion on the wall portion bottom end, the flange portion having a downwardly facing outer shoulder, a downwardly facing inner shoulder and a downwardly facing engaging member, the engaging member being received by the paint can rim channel about the rim circumference such that the outer shoulder bears upon the rim channel shoulder, the inner shoulder bears upon the rim channel inner lip and, when the paint is poured into the device, the wall portion directs the paint through the wall portion enclosure opening, and the flange portion isolates the paint can rim channel from the paint.
The foregoing and other objects and advantages will appear from the description to follow. In the 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 will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. In the accompanying drawing, like reference characters designate the same or similar parts throughout the several views.
The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawing in which:
FIG. 1 is an illustrative view of the present invention in use. Shown is the present invention installed on a paint can for the purpose of preventing paint from collecting in the paint can rim channel. Additionally the conical shape of the device provides a larger opening for dispensing the paint from the paint can as well as pouring the paint back into the paint can as from a roller tray.
FIG. 2 is an illustrative view of the present invention in use. Shown is the installed device being used in a typical paint application process. Normally, when applying paint by brush, the tendency is to extract excess paint by wiping the brush on the paint can interior rim. This often causes an undesirable accumulation in the paint can rim channel, interfering with the hermetic seal of the paint can, rendering long term storage useless. The conical shaped device of the present invention seals the paint lid-closing channel while providing an edge and interior work surface.
FIG. 3 is a perspective view of the present invention. The present invention has two lifting tabs aligned with the uppermost horizontal surface positioned roughly 180 degrees apart. These serve to facilitate positioning of the device atop a paint can and also to allow convenient removal without having to come in contact with the surfaces that may contain wet paint.
FIG. 4 is a top view of the present invention. The lower base of the device contains an aperture allowing for passage of paint into and out of the paint can. It is conveniently sized to overlap the paint can rim channel structure so as to further prevent possibility of contamination.
FIG. 5 is a cross sectional view of the conical device of the present invention. Shown is the exterior side of the paint can closure channel engaging member having a slope whereby the engaging member has a tapered side so that the engaging member will seat within the channel even though the channel may differ in distance across the rim of the channel.
FIG. 6 is a perspective view of the present invention with paint can positioned immediately beneath. The present invention has a flange portion conforming substantially to the paint can rim channel thereby forming a seal with the paint can.
FIG. 7 is a perspective view of the present invention in operating position atop a paint can. Shown is the conical device having oppositely opposed tabs located on the upper periphery acting as handles for attaching and removing the device from a paint can.
FIG. 8 is a cross sectional view of the present invention in use. Shown is a cross sectional view of the present invention mounted on a typical paint can, whereupon the conical shape of the invention increases the effective opening of the paint can. In addition, the engaging member of the invention is seated in the rim channel preventing paint from accumulating in the rim channel.
FIG. 9 is an enlarged view of the conical device flange portion shown in mating position with the paint can rim channel. The engaging member and shoulders of the flange portion form a mating seal with the paint can rim channel thereby no paint can enter said channel. The flange at the base of the device is sized to extend beyond the innermost lip of the paint can rim channel whereby any paint on the walls will drip into the interior of the can instead of running down the sides.
DESCRIPTION OF THE REFERENCED NUMERALS
Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, the figures illustrate the Paint Can Spill Guard of the present invention. With regard to the reference numerals used, the following numbering is used throughout the various drawing figures.
10 Paint Can Spill Guard of the present invention
11 paint can
12 paint
13 paint can outer side
14 paint can rim shoulder
15 paint can rim channel
16 paint can rim inner lip
17 paint can interior
18 paint brush
20 paint can spill guard wall
22 outer shoulder
24 inner shoulder
26 engaging member
28 engaging member tapered side
30 spill guard interior
32 spill guard opening
34 lift tabs
DETAILED DESCRIPTION OF THE INVENTION
The following discussion describes in detail the preferred embodiments of the invention. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well. For a definition of the complete scope of the invention, the reader is directed to the appended claims.
As shown in FIGS. 1-9, the spill guard 10 is specially adapted to be installed on the typical paint can 11 holding paint 12 . The paint can 11 has an outer side 13 which may be round or otherwise. The paint can 11 has a rim shoulder 14 extending radially inwardly on the top of the can 11 , with a rim channel 15 disposed inwardly from the rim shoulder 14 . The rim channel 15 has an inner lip 16 that generally forms the perimeter of the paint can 11 opening to the paint can interior 17 .
As shown in FIG. 2, a paint brush 18 is typically used and the brush 18 is often wiped free of loose paint 12 . Prior to the present invention this wiping usually occurred on the paint can 11 itself, leaving paint 12 in the rim channel 15 .
To avoid paint 12 accumulations the rim channel 15 , it is necessary to isolate the paint 12 from the rim channel 15 . The spill guard 10 of the present invention has a wall portion 20 that is generally conical, and has a flange portion at the lower end with an outer shoulder 22 , as shown particularly in FIG. 9 . This outer shoulder 22 follows the circumference of the paint can 11 rim, and abuts the paint can rim shoulder 14 .
Similarly, the spill guard 10 flange portion has a inner shoulder 24 and an engaging member 26 , with the engaging member 26 being closely received by the paint can rim channel 15 , and the inner shoulder 24 abutting the rim channel inner lip 16 . The engaging member 26 has an inner side 28 .
As shown in FIGS. 6-7, the spill guard 10 is lowered directly onto the paint can 11 . When so lowered, FIGS. 8-9 show the engaging member 26 seating in the paint can rim channel 15 , the outer shoulder 22 abutting the paint can rim shoulder 14 , and the inner shoulder 24 abutting the rim channel inner lip 16 . This seat isolates the rim channel 15 from paint 12 as the paint 12 shakes, or is wiped, from the brush 18 , as shown in FIG. 2 . This isolation is also maintained as the paint 12 is poured into the spill guard interior 30 and on through the spill guard opening 32 into the paint can 11 , as shown in FIG. 1 .
The seating of the spill guard 10 flange portion in the rim channel 15 also prevents paint 12 from missing the paint can 11 and causing a spill generally.
As shown in FIG. 5, a slight radially outward taper, of angle A, is present on the engaging member inner side 28 . This optional taper accommodates small variations in the width of the rim channel 15 , ensuring that the rim channel 15 is isolated even in situations when the rim channel 15 is slightly smaller than the full width of the engaging member 26 .
Generally planar lifting tabs 34 extend from the wall 20 in diametric opposition. The tabs 34 provide a convenient grasping point to lift or otherwise hold the spill guard 10 . The tabs 34 are of sufficient size to keep the hands away from the wall 20 and the spill guard interior 30 , to assist in keeping the hands free from paint 12 .
In another embodiment, the engaging member extends generally upwardly to the wall, while continuing to positively displace the rim channel 15 . In this embodiment, the inner shoulder 24 is eliminated.
With respect to the above description then, it is to be realized that the optimum material and dimensional relationships for the parts of the Paint Can Spill Guard 10 , will include variations in size, materials, shape, and form, which will occur to those skilled in the art upon review of the present disclosure. For example, the spill guard 10 is constructed from various woods, metals and plastics, either in a single piece or in individual components. In other embodiments, the flange portion engaging member is configured to accommodate non-circular paint cans, with the wall remaining generally conical, or changing to correspond to the non-circular paint can configuration. The spill guard 10 is also readily adapted to other liquid storage cans having a rim shoulder and a rim channel, as well. All equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
|
A device for positioning on the top of a liquid storage can to assist in the transfer of liquids, such as paint, in and out of the can, while simultaneously isolating the can top rim channel from the liquid being transferred. An engaging member on the device is received by the can rim channel to seal off the rim channel.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention is a divisional of U.S. application Ser. No. 09/652,632 entitled “An Interleaved Delay Line for Phase Locked and Delay Locked Loops” filed 31 Aug. 2000 and having common ownership.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is directed to phase locked and delay locked loops and, more particularly, to the delay line used in such loops.
[0004] 2. Description of the Background
[0005] A phase locked loop is a circuit designed to minimize the phase difference between two signals. When the phase difference approaches zero, or is within a specified tolerance, the phase of the two signals is said to be “locked”. A delay locked loop is similar to a phase locked loop, but instead of producing an output signal which has the same phase as an input or reference signal, the delay locked loop passes a reference signal or input signal into a delay line, and the output of the delay line has some predefined phase delay with respect to the reference or input signal.
[0006] Phase locked loops (PLL's) and delay locked loops (DLL's) are widely used circuits where it is necessary to have two signals which have a known relationship to one another. For example, when transmitting information from a sending device to a receiving device, it is necessary to have the local clock of the receiving device in sync with the clock of the sending device so that the information can be reliably transmitted. A PLL may be used for that purpose. Both PLL's and DLL's have been used for a long period of time, and numerous analog examples of these circuits can be found in the literature and in many devices.
[0007] Both PLL's and DLL's may be implemented either by analog components or digital components. In an analog loop, a delay chain is used to adjust delay and each element in the delay chain has its delay varied by analog bias voltages supplied by a phase detector. In a digital loop, rather than adjust the delay of, for example, a transistor, the delay is adjusted based on the number of delay stages that are included in the delay chain. Analog loops have continuous delay adjustments whereas digital loops adjust delays in discreet steps. As a result, one advantage of an analog loop is that the jitter is very low compared to the step jitter of a digital loop.
[0008] It is also known to implement loops in phases. For example, U.S. patent application No. ______, filed ______, (Micron No. 98-0788) entitled Digital Dual-Loop DLL Design Using Coarse and Fine Loops illustrates a circuit in which the delay line is comprised of both a coarse loop and a fine loop. The coarse loop is designed to produce an output signal having a phase variation from an input signal within a course delay stage while the fine loop is designed to produce an output signal having a phase deviation from the input signal which is substantially smaller than the deviation of the coarse loop. The coarse loop is designed to bring the output signal to a near phase lock condition, or phase delayed condition, while the fine loop is designed to achieve a locked condition. Thus, a dual-loop (coarse and fine loops) all digital PLL or DLL can provide a wide lock range while at the same time still providing a tight lock within reasonable time parameters.
[0009] There are several ways to implement the fine delay tap used in a fine loop. For example, one implementation embodies load-adjusting using a variable load capacitors. Another implementation is to provide both a fast path and a slow path using slightly different sized devices. The first method has little intrinsic delay and almost constant delay over process, voltage and temperature (PVT) variations. In contrast, the second method has a large intrinsic delay but provides better tracking for delay variations. Thus, a tradeoff must be made which is driven by the design parameters of the final device. Accordingly, a need exists for a DLL and PLL that have a large locking range, tight locking characteristics, little intrinsic delay, low power distribution and good tracking over PVT variations.
SUMMARY OF THE PRESENT INVENTION
[0010] The present invention is directed to an interleaved delay line for use in phase locked and delay locked loops. The present invention is comprised of a first portion providing a variable amount of delay substantially independently of process, temperature and voltage (PVT) variations while a second portion, in series with the first portion, provides a variable amount of delay that substantially tracks changes in process, temperature, and voltage variations. By combining, or interleaving, the two types of delay, single and multiple locked loops constructed using the present invention achieve a desired jitter performance under PVT variations, dynamically track the delay variations of one coarse delay stage without a large number of fine delay taps, and provide for quick and tight locking. Those, and other advantages and benefits, will be apparent from the Description of the Preferred Embodiment appearing hereinbelow. Methods of operating delay lines and locked loops are also disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For the present invention to be easily understood and readily practiced, the present invention will now be described, for purposes of illustration and not limitation, in conjunction with the following figures, wherein:
[0012] [0012]FIG. 1 is a block diagram of a memory device in which a DLL having an interleaved delay line constructed according to the teachings of the present invention may be used;
[0013] [0013]FIG. 2 is a block diagram of the DLL of FIG. 1 in conjunction with certain components of the memory device
[0014] [0014]FIGS. 3 and 4 illustrate two methods of implementing delay interpolation for the fine loop of a delay line;
[0015] [0015]FIG. 5 is a block diagram illustrating an interleaved delay line implementing the methods shown in FIGS. 3 and 4;
[0016] [0016]FIG. 6 illustrates a circuit for implementing a locked loop having an interleaved delay line;
[0017] [0017]FIG. 7 illustrates another method of implementing delay interpolation for the fine loop of a delay line;
[0018] [0018]FIGS. 8A, 8B and 8 C are simulations of the delay adjustment of the embodiments of FIGS. 3, 7 and 4 , respectively;
[0019] [0019]FIG. 9 illustrates the present invention used in a phase locked loop; and
[0020] [0020]FIG. 10 is a block diagram of a computer system using the memory device of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The present invention will now be described in conjunction with FIG. 1 which illustrates a memory device 10 . The reader will understand that the description of the present invention in conjunction with the memory 10 of FIG. 1 is merely for the purpose of providing one example of an application for the present invention. The present invention is not to be limited to the application shown if FIG. 1.
[0022] The memory device 10 includes, by way of example and not limitation, a synchronous dynamic random access memory device (SDRAM). As shown in FIG. 1, memory device 10 includes a main memory 12 . Main memory 12 typically includes dynamic random access memory (DRAM) devices which include one or more memory banks, indicated by BANK 1-BANK N. Each of the memory banks BANK 1-N includes a plurality of memory cells arranged in rows and columns. Row decode 14 and column decode 16 access the rows and columns, respectively, in response to an address, provided on address bus 18 by an external controller (not shown), such as a microprocessor. An input circuit 20 and an output circuit 22 connect to a data bus 24 for bi-directional data communication with main memory 12 . A memory controller 26 controls data communication between the memory 10 and external devices by responding to an input or reference clock signal (CLKref) and control signals provided on control lines 28 . The control signals include, but are not limited to, Chip Select (CS*), Row Access Strobe (RAS*), Column Access Strobe (CAS*), Write Enable (WE*), and Clock Enable (CKE).
[0023] A digital locked loop DLL 30 , constructed according to the teaching of the present invention, connects to input circuit 20 and output circuit 22 for performing a timing adjustment, such as skew elimination or clock synchronization between two clock signals. While the invention is described in the context of a DLL, the present invention is applicable to any type of PLL. According to the teachings of the present invention DLL 30 is an all digital loop. Those skilled in the art will readily recognize that the memory device 10 of FIG. 1 is simplified to illustrate the present invention and is not intended to be a detailed description of all of the features of a memory device.
[0024] [0024]FIG. 2 is a block diagram illustrating a portion of memory device 10 of FIG. 1 including main memory 12 , dual-loop DLL 30 and output circuit 22 . Output circuit 22 includes an output latch 32 connected to an output driver 34 . Output latch 32 is connected to main memory 12 via connection line 35 . Output driver 34 is connected to an output pad 36 which provides a data output signal DQ.
[0025] DLL 30 includes a forward path 38 having a first loop or coarse loop 40 connected to a second loop or fine loop 42 . In one embodiment, coarse loop 40 has a delay range up to 20 ns (nanosecond) to provide a wide frequency lock range. Fine loop 42 has a delay range from about 1 to 1.2 ns to provide a tight locking. Coarse loop 40 receives an input clock signal CLKref and a local clock signal CLK DLL on a feedback path 43 . Fine loop 42 is responsive to coarse loop 40 . Fine loop 42 also receives the CLKref signal and CLK DLL signal. Fine loop 42 outputs the local clock signal CLK DLL.
[0026] In a register-based all digital DLL, the phase jitter is primarily determined by the basic delay stage used in the delay line. Depending on the variations of process, supply voltage and temperature (PVT), the delay for one stage may vary from 130 ps to 350 ps. In a high-speed memory system, this skew has to be further reduced to ensure proper timing and valid data windows. The dual loop embodiment illustrated in FIG. 2 can be used to reduce the skew. The fine loop 42 can be used to provide fine delay interpolation and skew reduction after the coarse loop 40 is locked.
[0027] There are several ways to implement a fine delay line with a small delay resolution. FIGS. 3 and 4 illustrate two methods. FIG. 3 illustrates a method involving eight taps with which the load is adjusted while FIG. 4 illustrates a method involving a single tap with fast and slow paths.
[0028] The method in FIG. 3 employs a pair of series connected inverters 44 and 45 . The load can be adjusted through operation of switches 47 - 54 which can be used to switch capacitors 56 - 63 into the circuit. An implementation for one of the capacitors, capacitor 63 , is also illustrated. Each of the capacitors 56 - 63 may be implemented in a similar manner. The capacitor 63 is implemented through a pair of n-channel and p-channel transistors with their gate terminals connected together and, in the case of the p-channel device, the remaining terminals connected to a voltage source (e.g. V DD ) and, in the case of the n-channel device, the source and drain terminals are is connected to ground. By adding or removing the capacitors 56 - 63 , a delay can be achieved that can be increased or decreased in a step-wise fashion. That delay is almost constant over PVT variations. The method of FIG. 3 has a very small, e.g. 0.3 ns intrinsic delay. Here, intrinsic delay refers to the initial delay added to the loop when a fine loop is used. The intrinsic delay will slow down the loop operation which is generally not a good feature.
[0029] The embodiment illustrated in FIG. 4 includes a slow path 65 which is comprised of a first inverter 66 , a second inverter 67 , and a multiplexer 68 . A fast path 70 is similarly comprised of a first inverter 71 , a second inverter 72 , and a multiplexer 73 . By varying the size of the inverter in the slow path 65 , a different delay resolution can be achieved. Thus, the embodiment of FIG. 4 utilizes different paths to achieve a verniered delay. In contrast to the embodiment of FIG. 3, the delay varies with, or tracks, the variations in PVT, i.e. increasing in the slow corners and decreasing in the fast corners. However, a large intrinsic delay is introduced because of the two inverters and the multiplexer for each delay tap (0.3 ns per tap).
[0030] An interleaved delay line constructed according to the present invention is designed to use both delay interpolation methods to achieve:
[0031] (1) desired jitter performance under PVT variations;
[0032] (2) dynamic tracking of the delay variations without a large number of delay taps; and
[0033] (3) quick and tight locking.
[0034] A block diagram of such an interleaved delay line 75 is shown in FIG. 5. A shift register 76 in combination with multiplexers 77 and 78 forms a control circuit that is used to select different delay taps with the delay taps being selected alternately from the delay line comprised of load adjusting taps and the delay line comprised of fast/slow-path taps. Initially, half of these delay taps are selected which gives an M-tap tuning range for increasing or decreasing the delay. This arrangement gives more flexibility to eliminate the skew and other timing errors under PVT variations.
[0035] [0035]FIG. 6 illustrates a circuit for implementing the interleaved delay line 75 of FIG. 5. In FIG. 6, a phase detector 80 receives the signals CLKref, CLK DLL. The phase detector circuit 78 produces a FAST control signal and a SLOW control signal which are each comprised of pulses. The number of pulses in the FAST and SLOW control signals is representative of the difference in phase between the signals CLKref and CLK DLL. The FAST control signal is used for advancing the phase of the signal CLK DLL while the SLOW control signal is used to retard the phase of the signal CLK DLL. The FAST and SLOW control signals are input to a control block 82 . The control block 82 outputs signals to control the capacitive load of variable delay line 84 and to control the number of fast and slow paths connected in variable delay line 86 . The variable delay line 84 may be constructed as illustrated in FIG. 3 while the variable delay line 86 may be constructed as illustrated in FIG. 4. The signal OUT (which is the signal CLK DLL) is input via a feedback path, not shown, to the phase detector 80 . A coarse locked loop is typically added in front of delay line 84 , such that the delay line 84 is responsive to the coarse locked loop and the signal CLK DLL is input to the coarse locked loop. Through the implementation illustrated in FIG. 6, the advantages of both the variable delay line 84 and variable delay line 86 can be obtained.
[0036] In an exemplary embodiment, eight delay taps (M=8) were used for each delay line and the typical delay of the load-adjusting tap for delay line 84 was approximately 30 ps (t dl ), although the delay varied from 25 ps to 35 ps.
[0037] For the fast/slow variable delay line 86 , a typical delay for each stage was about 50 ps (t dp ) with a range of 35 ps-70 ps (per tap). The tuning range of this interleaved delay line can be calculated as:
t tune = M 2 ( t dl + t dp )
[0038] For above given numbers, t tune works out to be
[0039] 240 ps<t tune <420 ps
[0040] which covers the coarse delay per stage over PVT variations. The worst-case RMS jitter is below 35 ps and peak-to-peak jitter is less than 70 ps.
[0041] [0041]FIG. 7 illustrates another example of how the fine delay may be adjusted by adjusting the amount of drive. The phase detector 80 produces the FAST and SLOW control signals which are input to a selection control block 88 . The selection control block 88 produces signals for controlling individual drive stages 90 , 91 , 92 , 93 . One of the drive stages, drive stage 91 , is illustrated as a pair of parallel connected inverters, and one of the inverters is illustrated in detail in FIG. 7A. Thus, the selection control block 88 determines if one or both paths within drive stages 90 , 91 , 92 , 93 are used.
[0042] The following table compares the three types of delay discussed; namely, the load adjusting delay of FIG. 3, the drive adjusting delay of FIG. 7, and the fast/slow path adjustment of FIG. 4.
DELAY T D T D T D INTRINSIC DELAY INTERPOLATION DELAY TAP (FAST) (TYPICAL) (SLOW) (TYPICAL) Load Adjusting (1) ncap & pcap 27 ps 34 ps 38 ps 300 ps Drive Adjusting (2) 2 inverters (in parallel) 20 ps 30 ps 45 ps 780 ps Fast/Slow Path (3) 2 inverters each path 20 ps 50 ps 70 ps 1750 ps (in serial) & 1 MUX
[0043] An interleaved fine delay line can use any two of these three methods to achieve fast and tight locks. It is possible that if the last two methods are used, situations may arise in which the delay is varied nonlinearly as shown in the simulation results of FIGS. 8A, 8B and 8 C. Under those circumstances, duty cycle distortion of the output may occur. In terms of power distribution, the load adjusting delay is the best whereas the fast/slow path adjustment is the worst.
[0044] [0044]FIGS. 8A, 8B and 8 C are simulations based on using the load adjusting method of FIG. 3, the drive adjusting method of FIG. 7, and the fast/slow path method of FIG. 4, respectively.
[0045] While the present invention has been described in the context of a delay locked loop, the present invention may also be utilized in a phase lock loop as illustrated in FIG. 9. In FIG. 9, a course loop is comprised of a phase detector and control block 95 which controls a delay line 96 . The fine loop is comprised of a phase detector and control block 98 which controls an interleaved fine delay line 99 of the type, for example, illustrated in FIG. 6. The output of the interleaved fine delay line 99 is input to the delay line 96 through a digitally controlled oscillator 100 .
[0046] [0046]FIG. 10 illustrates a computer system 200 containing the SDRAM 10 of FIG. 1 using the present invention. The computer system 200 includes a processor 202 for performing various computing functions, such as executing specific software to perform specific calculations or tasks. The processor 202 includes a processor bus 204 that normally includes an address bus, a control bus, and a data bus. In addition, the computer system 200 includes one or more input devices 214 , such as a keyboard or a mouse, coupled to the processor 202 to allow an operator to interface with the computer system 200 . Typically, the computer system 200 also includes one or more output devices 216 coupled to the processor 202 , such output devices typically being a printer or a video terminal. One or more data storage devices 218 are also typically coupled to the processor 202 to allow the processor 202 to store data in or retrieve data from internal or external storage media (not shown). Examples of typical storage devices 218 include hard and floppy disks, tape cassettes, and compact disk read-only memories (CD-ROMs). The processor 202 is also typically coupled to cache memory 226 , which is usually static random access memory (“SRAM”) and to the SDRAM 110 through a memory controller 230 . The memory controller 230 normally includes a control bus 236 and an address bus 238 that are coupled to the SDRAM 110 . A data bus 240 may be coupled to the processor bus 204 either directly (as shown), through the memory controller 230 , or by some other means.
[0047] While the present invention has been described in connection with exemplary embodiments thereof, those of ordinary skill in the art will recognize that many modifications and variations are possible. Such modifications and variations are intended to be within the scope of the present invention, which is limited only by the following claims.
|
An interleaved delay line for use in phase locked and delay locked loops is comprised of a first portion providing a variable amount of delay substantially independently of process, temperature and voltage (PVT) variations while a second portion, in series with the first portion, provides a variable amount of delay that substantially tracks changes in process, temperature, and voltage variations. By combining, or interleaving, the two types of delay, single and dual locked loops constructed using the present invention achieve a desired jitter performance under PVT variations, dynamically track the delay variations of one coarse tap without a large number of delay taps, and provide for quick and tight locking. Methods of operating delay lines and locked loops are also disclosed.
| 8
|
BACKGROUND OF THE INVENTION
[0001] (1) Field of the Invention
[0002] The invention relates to the operational design of hard disk drives and more particularly, to an improved read/write seek procedure and associated components which provide good access times as well as reduced acoustic noise.
[0003] (2) Background of the Invention and Description of Previous Art
[0004] A disk drive is a data storage device that stores digital data onto concentric circular tracks defined on the surface of a data storage disk. Data is read from or written to a track of the disk using a transducer mounted on the tip of a head assembly of an actuator arm. The transducer comprises a read/write element. The element is held close to a desired track while the disk spins about its center at a substantially constant angular velocity. To properly locate the transducer near the desired track during a read or write operation, a closed-loop servo scheme is generally implemented to move the actuator arm. The servo scheme uses servo data read from the disk surface to align the transducer with the desired track.
[0005] In order to move the read/write head from over one track to over another, a controller sends a sequence of signals to a voice coil mounted within the field of a permanent magnet at the distal end of the actuator arm. The voice coil moves within the magnetic field according to the strength of the signal and thereby positions the read/write head at the other end of the actuator arm from one position to another over the tracks of the hard disk. The signals are derived from an procedure which is programmed into the controller and which optimizes the speed of the head for a smooth error free head travel. The procedure controls the speed of the read/write head from its starting location over an arbitrary track on the storage disk to its final position over a target track. The starting location is either over the track whereon the previous read/write operation was performed or at some other arbitrary or “parking” location. The path taken by the head is over an arc determined by the locus of the actuator arm to which the head is attached. Those skilled in the art are familiar with the operation of head controllers.
[0006] In order to move the head from its initial position to its target location as quickly as possible, the servo system must have instantaneous knowledge of the heads position, velocity, and acceleration and from this information, compute and dispatch incrementally forward looking values for these parameters to the actuator. This is accomplished by a feedforward control which causes the head to respond accordingly. The feedforward control is able to minimize tracking errors caused by known disturbances by compensating for them in advance. The process of directing the head from its starting location to its target location is referred to as a “seek” operation and the path by which the head travels is defined by a seek procedure.
[0007] Chu, et. Al., U.S. Pat. Nos. 6,801,384 B2 and 6,744,590 B2 describe the communication between a controller and a magnetic read/write transducer in detail wherein the path of the transducer is controlled by a sinusoidal seek procedure. In '590 the seek time is adjusted by observing the maximum velocity error of the previous seek. '384 includes all actuator electrical characteristics in setting the acceleration level. It is common practice to account for back emf in ‘bang-bang’ seeks. Both show a sine wave seek where position, velocity and acceleration are individually controlled in the time domain. Kobayashi, et. Al., U.S. Pat. No. 6,153,997 cites a seek procedure where the acceleration trajectory follows a trapezoidal/exponential function
[0008] Squires, et. al., U.S. Pat. No. 6,279,108 B1 cites a long seek procedure which is typical of those presently in use. This method produces good access times but also unwanted acoustic noise. It would be desirable to significantly reduce the acoustic noise while still obtaining good access times. Burton, et. Al., U.S. Pat. No. 6,515,820 describes a sine seek procedure whereby the velocity of the seek starts at zero and accelerates, following a sine wave until an acceleration saturation occurs. The sine seek controller receives velocity information and dispatches velocity feedforward data. It also computes a position error and a switch point curve. The switch point curve is is computed as an offset to a demand velocity curve which is stored in memory. When the velocity crosses the switch point curve, the feedforward signal changes from acceleration to deceleration and the velocity decreases until the demand velocity curve is crossed and then decreases linearly, reaching zero when the desired read/write head is over the target track.
[0009] Generally, a seek procedure independent of time is superior, particularly when gain variations and/or nonlinearities are present. This is so because It is found that forcing acceleration, velocity and position to zero simultaneously at a specific time is more difficult than forcing these parameters to zero without a time constraint.
[0010] If a seek is off the prescribed trajectory, as it typically is, the loop self-corrects by adjusting the acceleration and driving the seek back onto the trajectory, independent of time. If the acceleration feedforward is too low, the seek just takes a little longer but acceleration, velocity, and PES (Position Error Signal) are all simultaneously driven toward zero.
SUMMARY OF THE INVENTION
[0011] It is an object of this invention to provide a seek procedure for a hard disk drive which provides high performance as well as a significant reduction in acoustic noise.
[0012] It is yet another object of this invention to provide a seek procedure for a hard disk drive having a time domain acceleration.
[0013] It is still another object of this invention to provide a seek procedure for a hard disk drive which lowers the peak acceleration for short seeks to impart a smooth transition to an exponential arrival.
[0014] It is yet another object of this invention to provide a seek procedure for a hard disk drive which lowers the peak acceleration for long seeks to limit peak velocity.
[0015] It is still another object of this invention to provide a sine seek procedure for a hard disk drive providing an error free feedforward signal derived from a single sine table.
[0016] It is yet another object of this invention to provide a method to implement the seek procedure described by this invention.
[0017] These objects are accomplished by a seek procedure which implements a time domain sinusoid acceleration feedforward component combined with a phase-plane controlled velocity trajectory which, near seek completion, switches to an exponential arrival trajectory.
[0018] The procedure is constructed so that the acceleration begins at zero and, in the fashion of a sine, increases to a maximum, decreases to a minimum and then increases again until a computed switchpoint is reached. The switchpoint is determined in-situ, to provide a smooth velocity transition from sinusoid to exponential. The velocity trajectory is computed from a normalized look-up table.
[0019] Matlab® 2 is used to model the drive and simulate the seek system. The procedure is implemented in C or assembly language and a microprocessor. 2 Matlab is a registered trademark of The MathWorks, Inc., 3 Apple Hill Drive, Natick, Mass.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a normalized plot of the continuous time equations of motion use in the development of the sine seek procedure of this invention.
[0021] FIG. 2 is a plot of the normalized feedforward acceleration equation used in the development of the sine seek procedure of this invention.
[0022] FIG. 3 is a plot comparing normalized velocity vs. position for a sine seek path to circular and square root paths.
[0023] FIG. 4 is a plot illustrating the path of the acceleration feedforward of the sine/exponential seek procedure of this invention.
[0024] FIG. 5 is a graph showing the behavior of the exponential time constant τ as a function of the position of the sine-to-exponential transition in the sampling sequence of this invention for various values of the total number of samplings.
[0025] FIG. 6 is a plot of the position of the sine-to-exponential transition point M as a function of the total number of samplings N for the seek procedure taught in this invention and a τ of 10.
[0026] FIG. 7 is a plot of a family of curves of the calculated offset x adjust to the PES as a function of M/N for various values of N and a τ of 10,
[0027] FIG. 8 is plot of the calculated offset x (adjust) as a function of the total number of samplings N, for a τ of 10.
[0028] FIG. 9 is a plot of the sine-to-exponential transition point variable s the as a function of the time constant τ for the seek procedure of this invention.
[0029] FIG. 10 is a plot of the calculated offset K (adjust) as a function of τ for the seek procedure of this invention.
[0030] FIG. 11 is a flow chart illustrating the steps followed by the seek controller during the operation of the seek procedure disclosed by this invention.
[0031] FIG. 12 is a block diagram illustrating the operational layout of an actuator seek controller for the performing s sine/exponential seek operation using the principles and methods outlined by this invention.
[0032] FIG. 13 is a plot of a 1000 track seek showing the acceleration of the actuator head during the sine move with exponential arrival using the procedure taught by this invention.
[0033] FIG. 14 is a plot of a 1000 track seek showing the velocity of the actuator head during sine move with exponential arrival using the procedure taught by this invention.
[0034] FIG. 15 is a plot of the is a plot of a 1000 track seek showing the DAC output during sine move with exponential arrival using the procedure taught by this invention.
[0035] FIG. 16 is a plot of the is a plot of a 1000 track seek showing the velocity error of the actuator head during sine move with exponential arrival using the procedure taught by this invention.
[0036] FIG. 17 is a plot of actual current command in DAC counts delivered to the head assembly as a function of the sample number.
[0037] FIG. 18 is a plot of the actual and commanded velocities as a function of the sample number.
[0038] FIG. 19 is a plot of the position error of the head in tracks as a function of sample number.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] In an embodiment of this invention the quiet seek procedure of the invention is described and mathematically developed as an procedure with reference to a corresponding process flow illustrated by a flow chart in FIG. 11 and a block diagram in FIG. 12 . In the first section, the sine portion of the procedure is described. The second section describes the exponential arrival and the third, the transition from the sine movement to the exponential movement.
Sine Seek Movement
[0040] The continuous time equations of motion for the read/write head during a seek operation are given as follows:
[0000]
a
=
a
0
sin
(
ω
t
)
(
1
)
v
=
a
0
ω
(
1
-
cos
(
ω
t
)
)
(
2
)
x
=
a
0
ω
(
t
-
1
ω
sin
(
ω
t
)
)
(
3
)
[0000] where α is the acceleration, ν the velocity and x the position. ωt is a polar angle in radians wherein, when applied to a seek, ω is the reciprocal of the total time required to move the head from the starting position to the target track.
[0041] A normalized plot of these entities is shown in FIG. 1 . Note that acceleration α is a sine, velocity μ a raised cosine and position x is a sine on a ramp. The plot in FIG. 1 is normalized to 1000 samplings from start of the seek to arrival at the target track. This spans a complete sine cycle from 0 to 2π radians.
[0042] A normalized acceleration feedforward equation (4) can be extracted from the equations of motion supra.
[0000]
(
v
-
0.25
)
2
0.25
2
+
a
2
=
1
(
4
)
[0043] This is an equation for an ellipse. A plot of normalized acceleration vs. velocity is shown In FIG. 2 . The seek begins at the origin and travels one revolution clockwise (arrow) around the ellipse. To decouple acceleration from time the procedure would find the appropriate acceleration for a given velocity. At least two problems exist viz. 1) the origin is a stable location and the system would somehow have to be “started” and 2) for a given velocity, the polarity of the acceleration is not known. The system would know that if it had been accelerating, it probably still is, but at or near peak velocity the acceleration polarity is ambiguous. This means the feedforward needs to be time-based or tied to position.
[0044] Matlab® simulations of a position-based acceleration feedforward perform poorly. This ‘forces’ the acceleration feedforward to be time based.
Velocity Trajectory
[0045] A phase-plane velocity trajectory equation cannot be extracted from the equations of motion; the equations are transcendental. Matlab® can be used to obtain the data.
[0046] FIG. 3 is a plot of velocity vs. position for a sine wave acceleration. Also shown are a circle and a square root velocity trajectory (commonly used in disk drive seek procedures). The circle is similar to the sine however Matlab® simulations show it's usage to be unacceptable. Since there is no equation for the velocity trajectory, a lookup table must be used to find the desired velocity as a function of position. In the block diagram ( FIG. 12 ) this is noted as ν(x).
Sampled Data Equations of Motion
[0047] In order to apply the equations of motion to an application wherein the time intervals are represented by an ‘orderly set of successive time sampled data, such as the interchange of instructions and feedback between a moving read/write head of a disk drive and its controller, the time element ωt in the continuous equations is replaced with a normalized sample fraction. Substituting
[0000]
a
(
n
)
=
a
0
sin
(
2
π
N
n
)
(
5
)
v
(
n
)
=
a
0
N
2
π
(
1
-
cos
(
2
π
N
n
)
)
(
6
)
x
(
n
)
=
a
0
N
2
π
(
n
-
N
2
π
sin
(
2
π
N
n
)
)
(
7
)
[0000] into the continuous equations, the sampled data equations of motion become:
[0000]
ω
t
=
2
π
N
n
[0000] where N is the number of samples required for one full sine wave of acceleration. Thus when n=N the sine wave is complete. Note that N is not required to be an integer. The x=axis in FIG. 1 is labeled in two ways. The sine cycle labels indicate the position along the sine wave in radians according to equation (3). The sample labels indicate position along the sine wave in terms of the sample number n as defined by equation (7) for a selected value of N=1000 samples to complete one sine cycle. The value of n depends upon the ability of the controller hardware to complete one controller cycle of receiving and interpreting data, computing and dispatching feedforward parameters. The value of N in turn depends not only on that of n but also upon the seek length, that is the distance in sample units that the head must travel from its starting position to its target position.
[0048] Substituting n=N into equation (7) and solving for N one obtains:
[0000]
N
=
2
π
x
(
N
)
a
0
(
8
)
[0000] Thus a seek of length x(N) tracks requires N samples for completion and corresponds to a seek time. For short seeks a corresponding low value of N may not be practical and can cause instabilities in the seek. It is therefore necessary to define an N min . Then, for short seeks (N<N min ), the value of α 0 is changed and a new N is computed.
[0049] By inspection of equation (6), maximum velocity occurs at n=0.5*N (or cos θ=−1). Substituting N from the seek time equation, one obtains:
[0000]
v
max
=
a
0
N
π
=
2
π
a
0
x
(
N
)
(
9
)
[0050] In order to limit the acceleration so that a maximum velocity ν (NE) . is not exceeded, one substitutes N from the seek time equation (8) into the maximum velocity equation (9) and solves for peak acceleration to obtain:
[0000]
a
0
=
π
2
v
max
2
x
(
N
)
(
10
)
[0051] Determination of coast is not necessary if the drive never reaches coast velocity. This is a property of the drive design considered here. A different drive could easily necessitate a coast state. It would be straightforward for a person skilled in the art to add a coast state to the present sine seek procedure.
Exponential Arrival
[0052] Referring back to in FIG. 3 , it can be seen that the velocity trajectory of the sine seek curve becomes very steep near the target position. In fact, the slope is vertical at the target position. This means that the incremental gain of ν(x) in the block diagram ( FIG. 12 ) grows without limit. Left unchecked, this will cause the outer position loop to become unstable at or near the target position. This problem is overcome by switching the travel mode of the read/write head from a sine path to an exponential path at an appropriate time. At the switch point, which is preferably near the target track of the read/write head, the feedforward instructions begin exponentially decreasing the acceleration, approaching zero when the target track is reached. The preferred exponential arrival time response for this embodiment may be represented by the equation:
[0000] x=x i e −t/τ (11)
[0000] where x i is the head position at the switch point and τ is the exponential time constant
[0053] Differentiating equation (11) yields the velocity ν.
[0000]
v
=
-
x
i
τ
-
t
/
τ
(
12
)
[0000] Substituting x into (12) gives
[0000]
v
Exp
Traj
=
-
x
τ
(
13
)
[0000] where ν ExpTraj is the velocity trajectory during exponential arrival (box 121 of FIG. 12 ). Care must be taken with the sign in the exponential velocity trajectory equation. When x=PES we obtain.
[0000]
v
Exp
Traj
=
PES
τ
(
14
)
[0000] Now, differentiating velocity to get acceleration.
[0000]
a
=
x
i
τ
2
-
t
/
τ
(
15
)
[0000] and substituting ν into α one obtains:
[0000]
a
FF
=
-
v
Exp
Traj
τ
(
16
)
[0000] This is the acceleration feedforward needed to drive the PES to zero. A possible variation here is to exchange the estimated velocity for the trajectory velocity. The idea is that the acceleration feedforward α FF drives the head velocity to zero and the exponential velocity trajectory drives the PES to zero while the velocity minor loop balances these two efforts. This is most useful when the exponential arrival initial conditions are not favorable (e.g. v i ≠x i /tau). Matlab® simulations validate this idea.
[0000]
a
FF
=
-
v
Est
τ
(
17
)
[0000] ν Est is an estimated velocity which is calculated from the measured position of the head and the corresponding actuator current, which is proportional to acceleration. These are instantaneously available parameters during the seek. The actuator current is proportional to the acceleration. Box 126 of FIG. 12 is an estimator which makes this calculation. An estimator is a standard item found in control systems and in disk drive servos. The acceleration feedforward is then computed by dividing by τ ( FIG. 12 box 124 ).
[0054] Equations (16) and (17) represent two different ways of computing an acceleration feedforward. Equation (16) uses the desired trajectory while equation (17) uses the measured velocity. If the seek is precisely on the desired trajectory, the responses to both feedforward equations are the same. If the seek is off the trajectory, equation (17) will be superior. It is very unlikely that a seek will be precisely on the desired trajectory.
[0055] Because there is no easily implementable closed-form solution for the velocity trajectory, a lookup table must be used to find the desired velocity as a function of position. This is denoted by box 120 In FIG. 12 .
Calculation of the Sine Move to Exponential Arrival Switchpoint
[0056] The next objective is to provide a smooth transition from sine move to exponential arrival. This requires no discontinuities in the acceleration. However, the derivative of the acceleration is allowed to have a discontinuity.
[0057] One method of keeping the acceleration continuous during the transition is to force both the feedforward and the velocity error ν Err . to be continuous (see FIG. 12 ).
[0058] To force the feedforward to be continuous, the acceleration due to the sine wave trajectory must equal the acceleration due to the exponential arrival trajectory at the switch point.
[0059] The sine wave acceleration at the switchpoint (n=M) is straight forward. M is the sample where the switch from sine to exponential occurs. Substituting M into the sine move acceleration (5) yields:
[0000]
a
sin
e
(
M
)
=
a
0
sin
(
2
π
M
N
)
(
18
)
[0000] The exponential acceleration is a function of ν Est . Assuming a nominal system, ν Est will be equal to ν(n) in the equations of motion. Substituting ν(M) into (17) gives:
[0000]
a
exp
(
M
)
=
-
a
0
N
2
πτ
(
1
-
cos
(
2
π
M
N
)
)
(
19
)
[0000] Setting the α's equal and solving for τ yields:
[0000]
τ
=
-
N
(
1
-
cos
(
2
π
M
N
)
)
2
π
sin
(
2
π
M
N
)
(
20
)
[0000] Equation (20) is the requirement for the feedforward to be continuous. Note that τ is independent of α 0 .
[0060] FIG. 5 shows a family of curves plotting τ as a function of MIN for several values of N. The values of N are denoted in the figure alongside each curve. A value of τ is selected and the values of M/N for the for each N value at the selected τ are collected. Table I lists these values for a value of τ=10. From each of these, a value of M is calculated. These values of M are then plotted against N as illustrated in FIG. 6 .
[0061] The data is fitted to a straight line and the intercept at N=0 yields the desired value of M for the data shown in FIG. 5 for τ=10. The slope of the line is essentially 1 and the fitted intercept occurs at M=−18. The fitted values of M are also listed in Table I. Thus M=N−18. This means that, regardless of α 0 or seek length, and for a τ of 10, switching the acceleration feedforward 1 8 samples before sine move completion produces a continuous feedforward. For τ≠10, the process must be repeated and a new switch point computed.
[0000]
TABLE I
Values of MIN for various values of N at τ = 10 (from FIG. 5).
N
MIN
M (calc)
M (fitted) 1
M (fitted) /N
X (adjust) 2
−100
—
—
−118.19
—
—
0
—
—
−18.47
—
—
75
—
—
56.31
—
—
100
0.820
82.00
81.24
0.812
34.00
125
0.853
106.63
106.17
0.849
29.50
150
0.874
131.10
131.10
0.874
25.00
175
0.890
155.75
156.03
0.892
22.50
200
0.903
180.60
180.96
0.905
20.00
250
0.922
230.50
230.82
0.923
16.00
300
0.934
280.20
280.68
0.936
14.00
350
0.944
330.40
330.54
0.944
12.00
400
0.950
380.00
380.39
0.951
10.00
500
0.961
480.50
480.11
0.960
8.50
600
0.967
580.20
579.83
0.966
7.50
1 Linear least squares fit of M (calc).
2 Data from FIG. 7.
[0062] To force the velocity error to be continuous, ν (x) must equal x tgt /τ at the switch point. Assuming a nominal system, ν est will be equal to ν (n) in the equations of motion. This implies that:
[0000]
PES
(
M
)
τ
=
v
(
M
)
(
21
)
[0000] This equation has little chance of ever being valid exactly. Therefore we add an offset to PES, viz.
[0000]
PES
(
M
)
-
x
adjust
τ
=
v
(
M
)
Solve
for
x
adjust
(
22
)
x
adjust
=
PES
(
M
)
-
τ
v
(
M
)
(
23
)
[0063] Substitute from the equations of motion (note: PES (M) =x (N) −x (M) ).
[0000]
x
adjust
=
x
(
N
)
-
a
0
N
2
π
(
M
-
N
2
π
sin
(
2
π
M
N
)
)
-
τ
a
0
N
2
π
(
1
-
cos
(
2
π
M
N
)
)
(
24
)
[0064] Finally rearranging and taking X (N) from the seek time equation (7), we get:
[0000]
x
adjust
=
a
0
N
2
π
(
N
-
M
+
N
2
π
sin
(
2
π
M
N
)
-
τ
+
τ
cos
(
2
π
M
N
)
)
(
25
)
[0000] Equation (25) defines x adjust in a way that the velocity error is continuous at the sine to exponential switch point.
[0065] Referring to FIG. 7 there is shown a plot of x adjust vs. M/N for various values of N and for τ=10 and α 0 =1. Using the M/N,N data previously collected, the x adjust , N data are collected from FIG. 7 . The values of M (fitted) /N are read from Table I and the corresponding values of x adjust in FIG. 7 are collected. These values are marked by a point 71 on each curve in the figure and are listed in Table I. Note that, in this case, the x adjust values are favorably located (where the curves are ‘flat’).
[0066] Plotting x adjust vs. N produces the curve shown in FIG. 8 . The dots 81 are the x adjust , N data points, the line 82 is a curve fit to the data using the power expression:
[0000] x adjust =2337N −0.906 . (26)
[0000] Line 83 is X adjust =4000/N. 4000 was chosen because for large N, x adjust is increased by α 0 and for small N, x adjust is decreased by α 0 . These x adjust values are for α 0 =1 and τ=10. For α 0 ≠1, the x adjust value must be multiplied by α 0 .
[0000]
x
adjust
=
a
0
(
4000
N
)
(
27
)
[0000] For τ≠10, the process must be repeated.
Short Seek α 0 Reduction
[0067] One of the first steps of the each seek operation is the determination of the seek length x(N), the distance in terms of the number of tracks from the seek start to the target track. For short seeks, it is likely that N would be too small to permit a reasonable value for M, that is, it would set the switchpoint too far back into the sine wave. To overcome this problem a minimum value N min is defined as an empirical constant stored in memory. Then the value of α 0 is then adjusted to permit a reasonable switchpoint. Whereas in the previous derivation the switchpoint was determined as 18 from the calculated intercept of the M vs. N curve ( FIG. 6 ) which had a α 0 of 1, for the short seek we set N=N min and determine a new α 0 by allowing the intercept to become a variable s.
[0000] M=N−s (28)
[0000] A second equation (29) is then defined to set the switchpoint at a convenient fraction k s of the sine wave.
[0000] M=k s N (29)
[0000] Combining equations (28) and (29) and recognizing that k s sets a minimum value for N yields:
[0000]
N
min
=
s
1
-
k
s
(
30
)
[0000] This means that seeks faster than N min samples must have a smaller α 0 (Reducing α 0 increases N).
[0068] Substituting N min for N in the seek time equation and solving for α 0 yields
[0000]
a
0
=
2
π
x
(
N
)
N
min
2
(
31
)
[0069] For seeks not meeting N min this lowers α 0 such that all seeks of less than x(N min ) tracks have the same M and they will all take the same amount of time during the sine move. However, the time during the exponential arrival will not be constant because a shorter seek will have a smaller position (and velocity) initial condition and will therefore transition to the target track sooner. The seek time vs. the seek length will monotonically increase.
[0000] Switching from Sine Move to Exponential Arrival for τ≠10
[0070] In the section describing the calculation of the sine move to exponential arrival supra, τ is set to 10. The technique for obtaining M & x adjust are repeated for a range of τ's. FIG. 9 shows the results of these calculations for several values of τ with the new variable s replacing M.
[0071] The data was extracted from that displayed in FIG. 4 in the same manner as the data for FIG. 6 . The linear least squares fit of the data, shown by line 91 in FIG. 9 provides the equation (32) for s for various values of τ.
[0000] S= 1.6τ+2.3 (32)
[0000] Equation (32) should be used when setting up the seek constants for a given τ.
[0072] FIG. 10 shows the relationship between x adjust and τ where x adjust =α 0 K adjust /N. The value 4000 in equation (27) is now replaced by a new constant K adjust which is computed from the data in FIG. 8 collected for various values of τ The curve fit yields equation (33) for K adjust as a function of τ.
[0000] K adjust =4.37×τ 2.97 (33)
[0073] As in the case of equation (32) equation (33) should be used when setting up the seek constants for a given τ.
[0074] Two things are sufficient to keep the acceleration continuous when switching from sine move to exponential arrival: 1) the feedforward must be continuous and 2) the velocity error must be continuous. Equations (32) and M=N−S keep the feedforward continuous. Equation (33) and the expression X adjust =α 0 K adjust /N keep the velocity error continuous. Equation (32) has no part in K adjust .
Seek Procedure Summary, Step by Step
[0075] The following sequence of steps is followed by the disk seek controller to implement the procedure of the present invention. References are made to steps on the flow chart in FIG. 11 as well as to features in the block diagram in FIG. 12 :
1. Get Seek Length, X(N) and Calculate Seek Time, N( 111 ).
[0076] The disk controller receives the address of the target track from the microprocessor or host interface, directs the transducer to read its current position, and then computes the number of samples N required to reposition the transducer from the current track to the target track.
2. Test for Short Seeks (FIG. 11-112).
[0077] If N<Nmin, reduce α 0 with equation (31) and calculate a new N with equation (8) ( FIG. 11-112 a ).
[0000] 3. Compute ν (max) (( FIG. 11-113 ) Equation (9) and Test Against ν (NE) ( FIG. 11-114 ) for Long Seeks.
a) If ν (max) >ν (NE) , compute α 0 with equation (10), set ν (max) =ν (NE) , and compute a new N from equation (8) ( FIG. 11-114 a ).
4. Calculate Sine-to-Exponential Switch Point, M (Equations (32) and (28)) (FIG. 11-115).
5. Calculate X (adjust) (eqn 33 and X adjust =α 0 K adjust /N) and a new N=
[0079]
N
(
adjust
)
=
2
π
(
x
(
N
)
-
x
(
adjust
)
)
a
0
(
Equation
(
8
)
,
Fig
.
11
-
116
)
6. Start Seek (FIG. 11-117).
[0000]
a.) turn on sine feedforward using new N from step 5 ( FIG. 11-117 and FIG. 12 —switches 122 and 125 set to move).
b.) obtain velocity trajectory from normalized table ν(x) ( FIG. 12-120 ).
i) scale up position by total seek length and scale up velocity by ν (max) . ii) look up velocity for distance=X (N) −X (adjust)
7. At Sample M Switch to Exp Arrival.
[0000]
a. Switch to exponential feedforward (−ν(est)/τ) ( FIG. 12 switch 125 )
b. Switch to exponential velocity (PES/τ) ( FIG. 12 switch 122 )
i) seek as if distance=X(N).
8. Wait Until Done and Switch to Track Follow.
[0087] In step 1, the seek length is determined from the initial position of the read/write head and the position of the target track. The former is obtained by query of the servo controller, the later by request from the disk controller. From this the value of N (step 2) is easily determined from α 0
[0088] In step 3, ν (max) >is tested against a velocity which is not to be exceeded. ν (NE) , This value is a constant of the disk drive.
[0089] τ, the exponential time constant, is chosen by the designer. Too large a value will make the overall seek time become too large. Too small a value will not allow the system sufficient time to reduce any errors before arriving at the target location.
[0090] In the FIG. 12 boxes 121 and 124 are multipliers. The output of each box is the input times whatever's in the box. PES is the input to 121 . The multiplier in box 121 is 1/τ. Consequently 121 's output is PES/τ. The input to box 124 is ν(est) and the output is −ν(est)/τ. These procedures are standard and well known to those skilled in the field of servo control systems.
[0091] In FIG. 12 , boxes 127 , 128 , and 129 , labeled Kloop, Kdac, and Kact/s 2 respectively are relatively common in servo systems.
[0092] Kact is the actuator gain (or plant gain). The units here are tracks/sample 2 /mA. Depending on the situation, it is sometimes necessary to include the dynamic characteristics of the actuator in the model. In that case, this block is a transfer function. Fortunately, we can use a simple gain term and 1/s 2 .
[0093] Kdac is the digital to analog converter gain in mA/bit.
[0094] Kloop is the gain term used by the drive servo code to set the bandwidth of the velocity minor loop. The velocity minor loop is the path in FIG. 12 through the Est, Kloop, Kdac, Kact & back to the Est block. The minor loop bandwidth is roughly 500 Hz.
Calibrations of the Disk Drive
[0095] The calibrations necessary for the Implementation of the quiet seek procedure are described as follows:
(I) One Time Calibrations:
[0096] The composite gain Kact* Kdac (referred to within the firmware as “acceleration gain”) is calibrated on a one time basis after the drive is assembled in the factory. This calibration factor (with units of tracks/sample 2 /bit) is used in three ways in the quiet seek procedure. They are:
1) To generate the DAC command corresponding to the acceleration feedforward component used during the sine portion of the seek. 2) To generate the DAC command corresponding to the acceleration feedforward component used during the exponential arrival portion of the seek. 3) To “calibrate” the velocity estimator response based on the measured response characteristics of the drive.
(II) Boot Up Calibrations: None
(III) Adaptive Calibrations
[0100] Adaptive calibrations are continuously ongoing with each seek performed. Even when all system parameters aren't precisely known, the quiet seek will eventually converge to the target track with the acceleration, velocity, & position being driven to zero at the target track. This is particularly dictated by the phase plane (time independent) method of generating the acceleration feedforward term during exponential arrival. As our knowledge of the system parameters deviates from the ideal, the seeks will generally take longer to complete as the controller (with finite gain) compensates for the slight overshoot or undershoot incurred. In an effort to maintain predictable and repeatable seek times, the velocity error at the sine to exponential switch point is slowly driven to near zero in the controller firmware by a scheme that adaptively adjusts the acceleration gain to achieve this. This puts the actuator precisely on the exponential arrival trajectory as the target track is approached, minimizing errors that add variability in the total seek time.
[0101] Matlab® is used to model the drive and simulate the seek system. Matlab® simulations are incorporated as look-up tables.
[0102] Matlab® participates in the seek directly in two ways:
[0103] 1) It is used to generate a “folded over” normalized velocity trajectory table which is incorporated in the controller firmware. This is a look-up table of normalized velocity vs. normalized position used by the seek controller during the sine move to determine the desired velocity at any given position.
[0104] The velocity reference for the sinusoidal portion of the quiet seek is generated using a table contained in firmware. Since the velocity profile for the seek is symmetric about the seek midpoint, the table need only represent the trajectory for the first half of the seek. For the second half of the seek, the table is “folded over” and traversed in the reverse direction until the switch-point for the exponential arrival is reached.
[0105] In order that a single trajectory table can be utilized for all seek lengths which necessarily have different maximum velocities, the table seek length and velocity parameters are both normalized to 1. To conserve memory yet provide good accuracy at the end of the seek where precise velocity control is necessary, the table has zones of varying resolution. The highest resolution zone is at the beginning of the table (used at the beginning and end of the seek when velocities are lowest), with zones of decreasing resolution as the table is traversed to the end (used in the highest velocity mid-part of the seek).
[0106] The normalized velocity trajectory table is used to generate a velocity demand at any given position in a phase-plane approach. This normalized table is independent of actual acceleration as well as all system-specific parameters making it reusable across all platforms and systems. The table features multiple“zones” with varying resolution, insuring accurate trajectories at low velocities when transitioning to exponential arrival.
[0107] 2) It is used to generate a look-up table incorporated in the controller firmware which is used to:
[0108] a) determine the number of samples N required for any length seek as described by equation (8)
[0109] b) determine the actual peak acceleration α 0 for any length seek as described by equation (10) and
[0110] c) determine a highly precise increment used to step through the firmware sine table to generate an accurate acceleration feedforward current during the sine move.
Results
[0111] FIGS. 13 through 16 show the behavior of various parameters of the the sine/exponential seek process of the present invention as a function of time in seconds. FIG. 13 shows the acceleration sine curve 130 and the exponential curve 131 , the transition taking place at about 0.004 seconds. FIG. 14 shows the corresponding sine 140 and exponential 141 velocity.
[0112] FIG. 15 shows the behavior of the DAC output command 150 as a function of time and FIG. 16 shows the behavior of the velocity error 160 .
[0113] FIGS. 17 through 19 show the progression of actual seeks as a function of sample count. In FIG. 17 the current commands 170 delivered to the actuator of a head assembly in terms of DAC counts is shown as a function of the sample period number. This corresponds to the acceleration feedforward. FIG. 18 shows the corresponding velocity 180 in terms of number of tracks-per-sample-period. In the curve of FIG. 18 the both the actual velocity and the commanded velocity are identical and fall on the same curve 180 . The transition between the sine portion and the exponential arrival is so smooth and continuous that it cannot be casually discerned in either figure.
[0114] FIG. 19 shows the actual position error 190 driven smoothly to zero at the end of the seek. When the head reaches the target track at the end of the seek, a track following period occurs during which the desired read/write operation is performed. Then either a new seek is begun or the head may be returned to a designated parking zone, ready for the next seek.
[0115] While this 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.
|
a seek procedure for a hard disk drive which provides a significant reduction in acoustic noise as well as high performance fast seek times is described. The seek procedure lowers the peak acceleration for short seeks and imparts a smooth transition from a sine seek to an exponential arrival at the target track. The seek procedure provides an error free feedforward signal derived from a single sine table. The procedure which contains a time domain sinusoid acceleration feedforward combined with a phase-plane trajectory controlled velocity which, near seek completion. The procedure is constructed so that the acceleration begins at zero and, in the fashion of a sine, increases to a maximum, decreases to a minimum and then increases again until a computed switchpoint is reached. The switchpoint is determined in-situ, to provide a smooth and continuous velocity transition from sinusoid to exponential. The velocity trajectory is computed from a look-up table. The procedure is implemented using conventional seek controller servo components and commercially available operation software.
| 6
|
BACKGROUND OF THE INVENTION
The present invention relates to a sheet feeding apparatus to separate and feed individual sheets in a sheet storage device, and more particularly to a sheet feeding apparatus which is of the type that intermittently and separately supplies sheets from a storage device through a semicylindrical pickup roller to office automation equipment such as a printer.
An important problem in the sheet feeding art relates to stable and accurate feeding of sheets from a sheet storage device to equipment. Here, a description will be made with reference to FIGS. 13 to 16 in terms of an arrangement of a conventional sheet feeding apparatus and a problem inherent to such a conventional sheet feeding apparatus. In FIGS. 13 and 14, in response to setting a sheet-loaded sheet storage device 121 to a body of a laser printer 111, a sheet feeding apparatus, designated at numeral 141, supplies the laser printer 111 with sheets 123 pushed up by a push-up spring 122. The sheet feeding apparatus 141 comprises a semicylindrical pickup roller 144 coaxially fixed to a drive shaft 142, a stopping roller 147 disposed at both end portions (sides) of the semicylindrical pickup roller 144 and coaxially and rotatably couped to the drive shaft 142, a retard pad 146 disposed to be elastically brought into contact with the circumference of the semicylindrical pickup roller 144 by means of elastic members (springs) 145, and a sheet guide plate 148 for rotatably supporting the retard pad 146 to guide the sheets 123. The sheets 123 fed from the sheet feeding apparatus 141 are supplied through a carrying roller 149 into the body of the laser printer 111.
FIG. 15 is a cross-sectional illustration of the semicylindrical pickup roller 144 taken along a line X--X in FIG. 14. In FIG. 15, the semicylindrical pickup roller 144, being made of a rubber, is arranged to have a diameter slightly greater than the diameter of the stopping roller 147 and fixedly coupled through a core member 143 to the drive shaft 142. Further, the semicylindrical pickup roller 144 has a plurality of grooves 144a formed along its axis and has a notch 144c.
In operation, the sheets 123 placed in the sheet storage device 121, as mentioned above, are pushed up by the push-up spring 122 to be pressed against the stopping roller 147 whereby the sheets 123 are positioned for supply. Then, the semicylindrical pickup roller 144 is rotated by one revolution in a direction indicated by an arrow in FIG. 13, whereby a leading portion 144b of the semicylindrical pickup roller 144 comes into contact with a front portion of the uppermost (topmost) sheet 123 so that the uppermost sheet 123 is moved forwardly by means of a frictional force relative to the semicylindrical pickup roller 144. At this time, the retard pad 146 comes into contact with the sheets 123 other than the uppermost sheet 123 to suppress the supply of the sheets 123 by means of a sliding resistance to prevent the following sheets 123 from being supplied simultaneously with the uppermost sheet 123.
There is a problem which arises with such a sheet feeding apparatus, however, in that, in cases where the rigidity of the sheets 123 is low, when the second sheet 123 follows the uppermost sheet 123 moved forwardly by the semicylindrical pickup roller 144, the second sheet floats or rises as illustrated in FIG. 16 whereby the aforementioned sliding resistance between the retard pad 146 and the sheet 123 becomes low, that is, the retard pad 146 does not fulfil its function, to result in allowing the simultaneous supply of the more than one sheet 123.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a sheet feeding apparatus which is capable of preventing simultaneous supply of more than one sheet irrespective of the rigidity of the sheets.
One feature of this invention is that a projection is provided at a leading portion of a sheet pickup roller so as to prevent sheets from floating to avoid the simultaneous supply of the sheets.
According to the present invention, there is provided a sheet feeding roller having a cross section comprising an arc portion and a chord portion to substantially form a semicylindrical configuration, the sheet feeding roller being equipped with a projection at the chord portion and the projection being made of a material different from a material of the arc portion. A circumferential surface of the projection is arranged to have a coefficient of friction smaller than a coefficient of friction of the material of the arc portion.
Further, in accordance with this invention, there is provided a sheet feeding apparatus for intermittently feeding sheets, comprising: a sheet pickup roller fixed to a rotatable drive shaft and having a cross section comprising an arc portion and a chord portion to substantially form a semicylindrical configuration; cylindrical roller means rotatably coupled to the rotatable drive shaft and disposed at both sides of the sheet pickup roller; a pad biased by elastic means to be pressed against the sheet pickup roller and the cylindrical roller means; and a projection provided at the chord portion of the sheet pickup roller, the projection being arranged to come into contact with the sheet in response to rotation of the sheet pickup roller in a predetermined direction.
The projection has a length in its cross section to come into contact with the sheet over a range from a contact point between the sheet pickup roller and the pad to one end portion of the arc portion which acts as a leading portion at which the sheet pickup roller initially comes into contact with the sheet when rotating in a predetermined direction. An outer surface of the projection is lowered in cross-sectional height from a circumferential portion of the cylindrical roller means or protruded by a predetermined distance from the circumferential portion of the cylindrical roller means. Further, a film is adhered onto an outer surface of the projection, the film having a coefficient of friction smaller than a coefficient of friction of the sheet pickup roller.
Moreover, according to this invention, there is provided a sheet feeding apparatus for intermittently feeding sheets, comprising: a sheet pickup roller fixed to a rotatable drive shaft and having a cross section comprising an arc portion and a chord portion to substantially form a semicylindrical configuration; cylindrical roller means rotatably coupled to the rotatable drive shaft and disposed at both sides of the sheet pickup roller; a pad biased by elastic means to be pressed against the sheet pickup roller and the cylindrical roller means; and a guide member provided at the chord portion to extend along an axis of the sheet pickup roller, the guide member has a width to come into contact with the sheet over a range from a contact point between the sheet pickup roller and the pad to one end portion of the arc portion which acts as a leading portion at which the sheet pickup roller initially comes into contact with the sheet when rotating in a predetermined direction.
BRIEF DESCRIPTION OF THE DRAWINGS
The object and features of the present invention will become more readily apparent from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view showing a sheet feeding apparatus according to a first embodiment of this invention;
FIG. 2 is an enlarged view showing a sheet pickup roller and a guide member in the sheet feeding apparatus of the first embodiment of this invention;
FIG. 3 is a cross-sectional view showing an arrangement of the sheet pickup roller of the sheet feeding apparatus in the first embodiment of this invention;
FIGS. 4 to 8 are illustrations of a laser printer using the sheet feeding apparatus according to the first embodiment of this invention;
FIG. 9 is a cross-sectional view showing an arrangement of a sheet pickup roller of a sheet feeding apparatus according to a second embodiment of this invention:
FIGS. 10A and 10B are illustrations of a laser printer equipped with the sheet feeding apparatus according to the second embodiment of this invention;
FIG. 11 is a cross-sectional view showing an arrangement of a sheet pickup roller of a sheet feeding apparatus according to a third embodiment of this invention;
FIGS. 12A and 12B are illustrations of a laser printer equipped with the sheet feeding apparatus according to the third embodiment of this invention;
FIGS. 13 to 16 are illustrations for describing a conventional sheet feeding apparatus.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1 to 3, a description will be made herein below in terms of a sheet feeding apparatus according to a first embodiment of the present invention. FIG. 1 is a perspective view showing an arrangement of the sheet feeding apparatus according to the first embodiment of this invention. As illustrated in FIG. 1, the sheet feeding apparatus, designated at numeral 32, comprises a sheet pickup roller 4 fixedly secured to a drive shaft 12, a guide member 21 attached to a leading portion 4b of the sheet pickup roller 4 in its rotational direction, a stopping roller 7 disposed at both ends of the sheet pickup roller 4 and coaxially and rotatably couped to the drive shaft 12, a retard pad 6 disposed to be elastically brought into contact with the circumference of the sheet pickup roller 4 by means of elastic members 5, and a sheet guide plate 13 for rotatably supporting the retard pad 6 to guide sheets to be fed to equipment. FIG. 2 is an enlarged view showing the sheet pickup roller 4. As illustrated in FIG. 2, the sheet pickup roller 4 has a notch portion to substantially form a semicylindrical configuration and is composed of an outer portion and an inner portion which are integrally and fixedly coupled to each other. The outer portion of the sheet pickup roller 4 is made of a rubber or the like, and the inner portion thereof acts as a core member 14 of the sheet pickup roller 4 having a center through-hole into which the drive shaft 12 is inserted to be fixedly secured thereto so that the sheet pickup roller 4 is coaxially coupled to the drive shaft 12 to be rotatable in accordance with rotation of the drive shaft 12. Further, the core member 14 has a plurality of caves extending along the axis of the center through-hole. The guide member 21 is equipped with claw portions 22 at its both ends. The claw portions 22 are engaged with one cave 14b of the core member 14 from both the sides so that the guide member 21 is detachably attached to a predetermined portion of the sheet pickup roller 4. As seen from FIG. 3 which is a cross-sectional view taken along a line A--A in FIG. 2, the sheet pickup roller 4 has a diameter slightly greater than the diameter of the stopping roller 7 and further has in its circumference (outer portion) a plurality of grooves 4a extending along its own axis. The guide member 21 is positioned at a portion of the notch portion (designated at 4c) of the sheet pickup roller 4, i.e., positioned at the vicinity of a portion 4b of the sheet pickup roller 4 which acts as a leading portion when the sheet pickup roller 4 rotates in a predetermined direction. The guide member 21 is made of a material such as polyacetal resin and alkyl benzene sulfonic acid type resin having a coefficient of friction smaller than that of the material of the sheet pickup roller 4. That is, the guide member 21 has a smooth surface. A tip portion 21a of the guide member 21 is arranged to have a thickness whereby the guide member 21 attached to the sheet pickup roller 4 slightly protrudes outwardly from the outer circumference of the stopping roller 7 or the outer surface of the guide member 21 becomes substantially equal in height to the circumferential surface of the stopping roller 7. In this embodiment, as a preferable value, the protruding amount (t1 in FIG. 3) from the outer circumference of the stopping roller 7 is arranged to be 1 to 3 times the thickness of each sheet (3) to be fed. Further, a rear end portion 21b of the guide member 21 is arranged to be lowered with respect to the outer circumferential surface of the sheet pickup roller 4 or arranged to be substantially equal in height to the outer circumferential surface of the sheet pickup roller 4. Preferably, the range (arc-length) of the protruding portion 21a of the guide member 21 is set to be substantially equal to a range from the contact point between the guide member 21 and the retard pad 6 to the leading portion 4b of the sheet pickup roller 4 in the state that the leading portion 4b of the sheet pickup roller 4 comes into contact with the sheet (3) to be fed.
FIG. 4 is an illustration for describing the sheet supply passage of a laser printer when using the sheet feeding apparatus 32 according to this embodiment. In FIG. 4, sheets 3 are stored in a sheet storage device 31 which is in turn loaded to the body 11 of the laser printer. The front (tip) portion of the sheet storage device 31 is coupled to the sheet feeding apparatus 32. In a carrying passage of a sheet 3 fed from the sheet feeding apparatus 32 there is disposed a resist roller 42 for temporarily stopping the sheet 3. After passing through the resist roller 42, the sheet 3 enters into a carrying passage 43 where there is disposed a charger 35 for charging a recording device (photosensitive drum) 34, an exposure device 36 for converting recording information into optical information so that the recording device 34 is illuminated with the optical information to form an electrostatic latent image on the recording device 34, a developing device for giving a developer with respect to the electrostatic latent image on the recording device 34, a transfer device 38 for transferring the developer on the recording device 34 to the sheet 3, and a fixing device 39 for heating and fixing the developer on the sheet 3. Further, at a position close to the recording device 34 there is disposed a cleaning device 33 for removing the remaining developer from the recording device 34, and at an exit of the fixing device 39 there is disposed a sheet-discharging device 44 for guiding the sheet 3 on to an upper cover of the body 11 of the laser printer.
FIG. 5 shows a drive system for the supply of the sheets 3 into the laser printer body 11. In FIG. 5, a main motor 51 acts as a drive source to drive, through a first gear train 52, the recording device 34 (not shown), the developing device 37, the cleaning device 33, a second gear train 53, and a third gear train 54. The second gear train 53 operates, through a first solenoid type clutch 55, the resist roller 42 and further operates, through a second solenoid type clutch 56, the sheet feeding apparatus 32. The third gear train 54 operates the fixing device 39 and the sheet-discharging device 44.
A printing operation of the laser printer thus arranged will be described hereinbelow. In response to completion of supply of image information from a host computer (not shown), a scanner motor (not shown) of the exposure device 36 starts to rotate. When the rotational speed of the scanner motor reaches a given value and becomes stable, the main motor 51 starts to rotate to drive the recording device 34, the developing device 37, the fixing device 39, the cleaning device 33 and the sheet-discharging device 44 which are coupled to the first and third gear trains 52 and 54, thereafter start the output control of a semiconductor laser (not shown) of the exposure device 36 and the charging control of the charger 35. In this state, when the second solenoid type clutch 56 is operated, the sheet pickup roller 4 of the sheet feeding apparatus 32 rotates by one revolution whereby one sheet 3 in the sheet storage device 31 is supplied into the carrying passage 41 of the laser printer. The sheet 3 supplied takes a waiting state for printing by means of the resist roller 42. Further, the exposure device 36 starts to write the image information in the recording device 34 and the recording device 34 rotates for completely writing the image information. The image information written therein is developed by the developing device 37. On the other hand, the first solenoid type clutch 55 is operated at the timing that the front end portion of the sheet 3 supplied from the resist roller 42 is coincident with the transferring device 38, thereby starting the operation of the resist roller 42. Thereafter, the image information on the recording device 34 is transferred onto the sheet 3 in the transferring device 38. The aforementioned operation is repeatedly affected with respect to the following sheets 3. The sheet 3 on which the image information is transferred is supplied through the carrying passage 43 up to the fixing device 39. In the fixing device 39, the developer transferred on the sheet 3 is heated by a heating roller (not shown) to be fixed thereon.
Secondly, a description will be made hereinbelow in terms of an operation of the sheet feeding apparatus 32 for feeding the sheets 3 one by one. FIG. 6 is a cross-sectional view showing a principal portion of the sheet feeding apparatus 32 which takes the waiting state. In FIG. 6, the sheets 3 stored in the sheet storage device 31 is urged by means of a push-up spring 9 to be pressed against the stopping roller 7 and positioned thereby. At this time, the guide member 21 does not yet come into contact with the sheets 3. In response to a command for start of the sheet supply, the sheet pickup roller 4 starts to rotate in a direction indicated by an arrow. FIG. 7 is a cross-sectional view showing the principal portion of the sheet feeding apparatus 32 which takes a state immediately after the start of the sheet supply. In FIG. 7, the guide member 21 presses the front portion (preceding portion) of the uppermost sheet 3 from the upper side and slightly feeds the uppermost sheet 3. Here, since the guide member 21 is made of a material whose frictional coefficient is lower than that of the sheet pickup roller 4, the uppermost sheet 3 cannot be completely forwarded. Further, since the guide member 21 is arranged to be slightly protruded from the circumference of the stopping roller 7 or to be substantially equal in height to the circumference thereof, the front portion of the sheet 3 subjected to the feeding force due to the guide member 21 can be prevented from floating and strongly guided toward the sliding surface of the retard pad 6. FIG. 8 is a cross-sectional view showing the principal portion of the sheet feeding apparatus 32 which takes a sheet-feeding state. In this sheet-feeding state, the front portion of the uppermost sheet 3 is brought into contact with the circumferential surface of the sheet pickup roller 4 to be sent out through a frictional force relative thereto, and is surely brought into contact with the retard pad 6 under a pressure due to the guide member 21. Thus, even if the uppermost sheet 3 and the second sheet 3 are integrally piled up to each other by an electrostatic suction force or friction, the retard pad 6 can surely control the second or other sheet so as to prevent the simultaneous supply of the multiple sheets 3. Thereafter, the sheet 3 sent out from the sheet feeding apparatus 32 is supplied through carrying rollers (8 in FIG. 6) into the laser printer and then carried and processed as described above.
In addition, a description will be made hereinbelow with reference to FIG. 9 in terms of an arrangement of a sheet feeding apparatus according to a second embodiment of this invention. FIG. 9 is a cross-sectional view taken along the line A--A in FIG. 1 where parts corresponding to those in FIG. 3 are marked with the same numerals and the description thereof will be omitted for brevity. In FIG. 9, a sheet pickup roller 204, made of a rubber or the like, has a diameter slightly greater than that of a stopping roller 7, and has a number of grooves 204a extending along its own axis on its circumference and has a notch portion 204c at a portion of the circumference. Further, the sheet pickup roller 204 has a projection 204d at its leading portion 204b which first faces sheets when rotating in a predetermined direction for the pick-up of the sheets. This projection 204d may be made of the same material (rubber) as the sheet pickup roller 204 body (outer portion of the sheet pickup roller 204) and may be integrally constructed together with the sheet pickup roller 204 body. The projection 204d has a circumferential surface (arc-shaped surface) substantially extending along the circumference of the sheet pickup roller 204 or the circumference of the stopping roller 7. Onto the circumferential surface of the projection 204d there is adhered a film 205 made of a material such as a resin which has a coefficient of friction smaller than that of the sheet pickup roller 204 body. Preferably, the film 205 is made of tetrafluoroethylene polymer. The circumferential surface of the film 205 is arranged to have a diameter whereby the film 205 is positioned to be slightly lowered with respect to the circumference of the stopping roller 7 or substantially become equal in height to the circumference of the stopping roller 7. Preferably, the lowered amount (12 in FIG. 9) of the film 205 is set to be 1 to 3 times the thickness of the sheet (3). The projection 204d will be effectively used when its length is set to be equal to a range from the contact point between the projection 204d (film 205) and a retard pad 6 to the leading portion 204b of the sheet pickup roller 204 in the state that the leading portion 204b of the sheet pickup roller 204 comes into contact with the sheet (3) to be fed. Here, if the sheet pickup roller 204 is made of a rubber whose elasticity is slight so that the sheet pickup roller 204 is scarcely dented, it is appropriate that the projection 204d is arranged to be similar in shape and structure to the guide member 21 in FIG. 3.
Secondly, a description will be made hereinbelow in terms of an operation of the sheet feeding apparatus for feeding sheets by one. FIG. 10A is a cross-sectional view showing the principal portion of the sheet feeding apparatus which takes a state immediately after the start of the sheet-feeding operation. In FIG. 10A, the projection 204d first presses the front portion of the uppermost sheet 3 from the upper side and slightly sends out the uppermost sheet 3. Here, since the film 205 having a coefficient of friction smaller than that of the sheet pickup roller 204 is adhered through an adhesive onto the circumferential surface of the projection 204d, the sheet 3 is not completely sent out therefrom. Further, since the outer surface of the film 205 is arranged to be lower or equal in height to the stopping roller 7, it is possible to prevent the front portion of the sheet 3 fed from floating before sending it out to the sliding surface of the retard pad 6. FIG. 10B is a cross-sectional view showing the principal portion of the sheet feeding apparatus which takes a sheet-feeding state. In this sheet-feeding state, the front portion of the uppermost sheet 3 is sent out through a frictional force relative to the circumferential surface of the sheet pickup roller 204 and surely pressed against the retard pad 6 by means of the projection 204d. Thus, it is possible to surely and accurately feed only the uppermost sheet 3 because the second and other sheets are controlled by the retard pad 6, thereby preventing the simultaneous supply of the multiple sheets. Thereafter, the sheet 3 fed from the sheet feeding apparatus is supplied through carrying rollers (8) into the laser printer and printing-processed as described above.
Here, even if the projection 204d is arranged to be similar in structure to the guide member 21 in FIG. 3, it is possible to offer the same effect.
Moreover, a description will be made hereinbelow in terms of a third embodiment of this invention. FIG. 11 is a cross-sectional view taken along the line A--A in FIG. 1, showing a sheet pickup roller of a sheet feeding apparatus according to this embodiment where parts corresponding to those in FIG. 3 are marked with the same numerals and the description thereof will be omitted for brevity. In FIG. 11, a sheet pickup roller 304 whose outer portion is made of a rubber or the like has a diameter slightly greater than that of a stopping roller 7 and has a number of grooves 304a extending along its own axis. Further, the sheet pickup roller 304 has a notch portion 304c and a projection 304d at a leading portion which first faces sheets when rotating in a predetermined direction for the pick-up of the sheets. The projection 304d and the sheet pickup roller 304 may be made of the same material and integrally constructed with each other.
The projection 304d has a circumferential surface (arc-shaped surface) substantially extending along the circumference of the sheet pickup roller 304 or the circumference of the stopping roller 7. The circumferential surface of the projection 304d is arranged to have a diameter smaller than that of the stopping roller 7. Preferably, the lowered amount (t3 in FIG. 11) of the projection 304d is set to be approximately 5 times the thickness of the sheet (3). The projection 304d will be effectively used when its length is set to be equal to a range from the contact point between the projection 304d and a retard pad 6 to the leading portion 304b of the sheet pickup roller 304 in the state that the leading portion 304b of the sheet pickup roller 304 comes into contact with the sheet (3) to be fed. Secondly, a description will be made hereinbelow in terms of an operation of the sheet feeding apparatus for feeding sheets one by one. FIG. 12A is a cross-sectional view showing the principal portion of the sheet feeding apparatus which takes a state immediately after the start of the sheet-feeding operation. In FIG. 12A, the projection 304d first presses the front portion of the uppermost sheet 3 from the upper side and slightly sends out the uppermost sheet 3. Here, since the outer surface of the projection 304d is arranged to be lower in height than the circumferential surface of the stopping roller 7, it is possible to prevent the front portion of the sheet 3 from floating, before guiding it to the sliding surface of the retard pad 6. FIG. 12B is a cross-sectional view showing the principal portion of the sheet feeding apparatus which takes a sheet-feeding state. In this sheet-feeding state, the front portion of the uppermost sheet 3 is sent out through a frictional force relative to the circumferential surface of the sheet pickup roller 304 and surely pressed against the retard pad 6 by means of the projection 304d. Thus, it is possible to surely and accurately feed only the uppermost sheet 3 because the second and other sheets are controlled by the retard pad 6, thereby preventing the simultaneous supply of the multiple sheets. Thereafter, the sheet 3 fed from the sheet feeding apparatus is supplied through carrying rollers (8) into the laser printer and printing-process as described above.
It should be understood that the foregoing relates to only preferred embodiments of the present invention, and that it is intended to cover all changes and modifications of the embodiments of the invention herein used for the purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.
|
A sheet feeding apparatus for intermittently feeding sheets one by one into printing equipment. The apparatus comprises a sheet pickup roller fixed to a rotatable drive shaft, a pair of cylindrical rollers rotatably and coaxially coupled to the drive shaft and disposed at both sides of the sheet pickup roller, and a pad biased by a spring to be pressed against the sheet pickup roller and the cylindrical rollers. The sheet pickup roller has a cross section comprising an arc portion and a chord portion to substantially form a semicylindrical configuration. Also included in the apparatus is a projection provided at the chord portion of the sheet pickup roller. The projection is arranged to come into contact with the sheet over a range from a contact point between the sheet pickup roller and the pad to one end portion of the arc portion which acts as a leading portion at which the sheet pickup roller initially comes into contact with the sheet when rotating in a predetermined direction.
| 1
|
BACKGROUND
A continuing goal is to have more energy saving and a lower energy bill amount for buildings (both for residential and commercial), which has an added benefit of reducing the emissions that cause global warming. One way is to reduce the amount of energy escaping/exchanging through windows. A method of measuring the efficiency of insulation for heat transfer is R-value. An R-value indicates the insulation's resistance to heat flow. (A higher R-value would indicate a greater insulating effectiveness.) The R-value generally depends on the type of insulation (e.g. material, thickness, and density). To find the R-value of a multilayered system, one would add the R-values of the individual layers.
In the current invention, press-fit storm windows are installed on existing frames or windows, without the hassle and expense of replacing the whole window (to save time, cost, and inconvenience), to increase R-value for the windows (i.e. reduce energy waste).
In the prior art, U.S. Pat. No. 7,481,030 teaches methods and structures for sealing air gaps in a building. It teaches a seal structure for sealing an air gap between a framing member and a wallboard, the seal structure being formed on a framing member from a curable, flowing material and comprising: a body having first and second opposing surfaces, the first surface of the body being bonded to the framing member; and at least one flexible seal member integral with and extending generally transversely with respect to the second surface of the body, the seal member; wherein the body and the at least one seal member are formed from air curable silicone caulk on said framing member defines a seal between the framing member and the wallboard, when the wallboard engages a distal end of the seal member.
In the U.S. Pat. No. 7,546,793 (dated Jun. 16, 2009) (titled “Window component notching system and method”), LaSusa teaches: A system and method for producing window components using polymer based, metallurgy based, extruded, injection molded, or wooden lineal material. The lineal material is notched at intervals calculated to include a stretch treatment and folded to form window components, such as window sashes, frames, and the like. Internal reinforcing members may be welded within the joints formed by folding at the notches. The notching system and method provide low cost, highly reliable, low defect production of multi-sided window components from a continuous piece of lineal material.
U.S. Pat. No. 7,490,445, Steffek et al., dated Feb. 17, 2009, titled “Integrated window sash”, teaches: An integrated window sash, which includes a sash frame having a first sheet supporting surface, a second sheet supporting surface spaced from the first sheet supporting surface, and a base between the first and second sheet supporting surfaces, the base defining an opening; a first sheet having a first major surface and an opposite second major surface with marginal edge portions of the first surface of the first sheet secured to the first sheet supporting surface, the first sheet sized to pass through the opening toward the first sheet supporting surface; a second sheet having a first major surface and an opposite second major surface with marginal edge portions of the first surface of the second sheet secured to the second sheet supporting surface, the second sheet sized to be larger than the opening, wherein the first major surface of the second sheet faces the second major surface of the first sheet and is spaced therefrom to provide a compartment between the sheets; and a retainer mounted on the base between the sheets and having a first end portion engaging surface portions of the second surface of the first sheet and an opposite second end portion secured to the base.
Embodiments of the invention address these and other problems in the prior art.
SUMMARY
Embodiments of the present invention relate generally to easily and inexpensively adding a primary or secondary panel to an existing framed opening in a building. New demands emerging on the energy or audio characteristics of buildings are requiring increasingly expensive and difficult-to-install devices (and related methods). This particularly applies to historic buildings, but can apply to recent structures built before the awareness of the importance of energy and audio efficiency. At present, there is no device or method that is well accepted as adequately low in cost, outstanding in appearance and performance, and simultaneously easy to install. Therefore, an advantage of the preferred embodiments of the present invention is to provide energy and/or sound isolating panels suitable for use in any building.
In embodiments of the current invention, we introduced an easy way (and less expensive) of installing the press-fit storm window, on existing frames or windows, without the hassle and expense of replacing the whole window (to save time, cost, and inconvenience), to increase R-value for the windows (i.e. reduce energy waste).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the extrusion to put around edge of a press fit storm window to allow a pressure fit into window frames (profile view).
FIG. 2 shows the extrusion to put around edge of a Press Fit Storm Window™ to allow a pressure fit into window frames (Front or rear view).
FIG. 3 shows the extrusion to put around edge of a Press Fit Storm Window™ to allow a pressure fit into window frames (Installation view).
FIG. 4 shows the view of the upper corner, as installed.
FIG. 5 shows the view of the upper corner, as un-installed or removed.
FIGS. 6 ( a ), 6 ( b ), and 6 ( c ) show silicon molded corner piece, in 3 different views/angles.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In one embodiment of the inventive press-fit storm window, a transparent panel of acrylic glass, such as PLEXIGLAS, glass, or other clear rigid material is held in place by the spring action created by a continuous (or partial, conceivably) round gasket (or other spring-like gasket), that creates outward pressure around the entire exterior edge of the clear panel (or the top, left, and right sides).
The panel is held securely in place through a combination of this outward pressure and friction. The press-fit storm window can be installed on the interior or exterior of a structure. The windows are not designed to replace existing windows, but rather to supplement them by creating a tight seal between the interior space or exterior space and the existing window.
The benefits of the device are much greater insulation (R value, technically) for an existing window (energy-efficient or lower energy bills), as well as a significant reduction in noise passing through the window or portal into which the press-fit storm window is placed. The device will be dramatically less expensive than upgrading an existing single pane window to a more efficient dual pane window, without any real cutting the walls, which entails construction of the outside and inside, which means inconvenience and expense (reluctance to upgrade), for the home owners.
Another benefit is that these press-fit windows will preserve the architectural integrity of the existing windows, in older homes. Customers will be able to install the windows in a matter of minutes with no screws, nails, or adhesives, which points to a third major benefit of the windows: They provide dramatic environmental and efficiency improvements, while preserving the architectural integrity of homes.
FIG. 1 shows the extrusion to put around edge of a press fit ( 440 ) storm window to allow a pressure fit into window frames (profile view). FIG. 1 displays round or oval shaped tube formed from a springy material with ‘hollow’ interior ( 102 and 104 , or 402 and 410 , or 502 and 510 ). ‘Hollow’ space could be air or foam. ‘Channel groove’ connects bulb to clear panel ( 106 , 108 , and 110 ). It also shows ‘spring’ plastic extrusion, which is UVA resistant. (It will be exposed to sunlight, heat, and cold.) As an example, ⅛″ clear acrylic glass panel (PLEXIGLAS) is used, but other material can be used, as well ( 130 or 530 ).
FIG. 2 shows the extrusion to put around edge of a press-fit storm window to allow a pressure fit into window ( 560 ) frames ( 540 and 542 ) (Front or rear view) ( 210 , 212 , 214 , and 220 ). FIG. 2 shows that the spring tube extrusion is fitted around the panel. Corners are cut at 45 degree angle ( 216 and 218 ) and sealed with thermal sealer or glue, as an example, but it can be any other form/angle and any adhesive method. It shows ⅛″ acrylic glass, front or rear view ( 230 ). FIG. 2 shows the bottom extrusion, possibly of a different material, formed into a similar profile. Material could be of a semi-rigid and non compressing tube to prevent ‘droop’, as an example of embodiments, but not limiting the scope of the invention.
FIG. 3 shows the extrusion to put around edge of a press-fit storm window to allow a pressure fit ( 350 , 352 , and 354 ) into window frames (Installation view), at the edges ( 322 and 324 , or 522 ) and sides ( 310 , or 408 , 312 , 314 , and 320 , or 508 ). FIG. 3 shows the plastic tube is fitted ( 516 ) around acrylic glass panel ( 330 or 430 ). Corners are cut at 45 degree angle ( 316 and 318 or 418 ) and sealed with a thermal sealer. These are just some examples for one embodiment, and can be any other angle and any other sealant or adhesive, commonly known and used for windows. It displays ⅛″ acrylic glass, front or rear view. It shows the plastic extrusion, when compressed by after being pressed into the window frame ( 340 ), which creates an outward pressure that holds the acrylic glass into place.
The other figures display various views and configurations for the setup described above. FIG. 4 shows the view of the upper corner, as installed. FIG. 5 shows the view of the upper corner, as un-installed or removed.
FIGS. 6 ( a ), 6 ( b ), and 6 ( c ) show silicon molded corner piece, in 3 different views/angles, which is another embodiment, with some different features. The shape shown in FIG. 6 makes it easier to fit the window, and seal it better, with better flexibility, for minor adjustments, and accommodating imperfections in the original frame or window. Note the shape at the corner, and also the layered structure (with tube and skin, or shell, plus a narrow fin on the back), as shown in FIG. 6 , for better flexibility and coverage. The typical distances are: 1.25″ for a, (⅜)″ for b and c, (⅝)″ for d, and 0.5″ for e, as distances shown in FIG. 6( b ). However, these values can range from 10 percent of these typical values to 500 percent of these typical values, and this invention would still work.
In an example, item 603 or 607 or 637 in FIG. 6 represents outer layer or shell; 601 or 609 or 639 or 631 is the inner layer, with inner cross section 611 , and a gap 613 ; 619 is the angled cut to attach the pieces 603 and 607 together; 615 and 605 or 635 are parallel plates, with a gap 617 between them; 643 is a notch for better coverage and flexibility; and 641 is the fin at the corner of 637 , for better coverage/adhesion/insulation and flexibility; variously shown at different angles, in three figures, FIGS. 6 ( a ), 6 ( b ), and 6 ( c ).
In one of the embodiments, a rubber bulb is added around all edges of a rigid plastic sheet cut to fit inside a window frame. It was intended that metal clips be used to ensure that the panel would stay in place. The assembled panel was first pressed tightly inside the frame. To their surprise, when attempting to remove the panel from the frame, it was found to be necessary to use a prying device. This indicated that the use of the metal clips would unexpectedly not be required, thereby greatly simplifying installation. Thus, this embodiment is very simple, practical, and yet, still, strong.
However, other methods can be combined here, as well: For example, in another embodiment, the panel can also be attached with glues, mechanical clamps, screws, or spring-like o-rings, or combinations of the above. The pressure can be exerted on all sides, one or more sides, locally at the corners, at a selected points only, or by suction (due to pressure difference between the two sides). For example, by a slight variation of the pressure on both sides, the difference on the pressure can partially or fully hold the panel in place.
In another embodiment, the panel can be in place using hangers, belts, chains, ribbons, frames, railings, or gap in frame of the window. In another embodiment, the panel can be hung through a metal or plastic rebar perpendicular to the surface of the panel.
In another embodiment, the panel can be held using its own weight or gravity, partially or fully supported, by using the slight inclined surface, with respect to the ground and a plane perpendicular to the ground. That is, we held the panel not exactly perpendicular to the ground or 90 degrees, but slightly off, say e.g. at the 85 degree angle, with respect to the ground (instead of 90 degrees). It can vary in the range of 80 to 89 degrees, for example.
In another embodiment, the panel can be curved, rather than flat, to stand on it own, based on its center of gravity. This way, the panel can stand on its own by its weight, fully or partially, as long as the center of gravity for the panel is within the boundary of the shadow of the window's frame, to have a stable system, holding up on its own. Of course, we can combine the embodiments above, to make the panel better attached to the window or frame, in the case of snow, fast wind, or storm.
Additional embodiments are, in combination or not-in-combination to above:
i. Use trim with multiple slots or openings to accept the panels. This would allow multi-pane windows.
ii. Use separate corner pieces of trim and bulb, to eliminate bevel cuts and improve appearance.
iii. Use stiffeners before installing trim.
The material used for frames can be plastic, metal, elastic, man-made, natural, or a combination of the above. The shape of windows can be square, rectangular, circle, ellipse, polygon, curved, irregular, symmetric, or not-symmetric, as an example.
Here are more variations and examples:
1. Panel(s) (fills framed opening in building):
a. Materials:
i. Plastic ii. Glass iii. Wood iv. Metal v. Other
b. Purposes:
i. Light transmission ii. Thermal Insulation iii. Sound isolation iv. View v. Privacy vi. Security vii. Bulletproofing
c. Light Transmission:
i. Clear, Transparent ii. Translucent iii. Opaque iv. Reflective v. Colorless vi. Colored
d. Shape:
i. Rectangular ii. Square iii. Polygon of any description iv. Round v. Oval vi. Elliptical vii. Irregular viii. Angled to vertical or Curved ix. Any other
2. Trim (fastens over and frames edge of panel):
a. Material:
i. PVC ii. EPDM iii. Silicone iv. Plastic v. Rubber vi. Metal vii. Other
b. Shape:
i. “C” iv. “L” v. Other
3. Internal Clip (internal to and stiffens trim):
a. Material:
i. Aluminum ii. Steel iii. Plastic iv. Rubber v. Other vi. None
b. Shape:
i. “C” ii. “U” iii. “V” iv. “L” v. Other vi. None
4. Bulb (fastened to or same extrusion as trim):
a. Material:
i. PVC ii. EPDM iii. Silicone iv. Other
b. Shape:
i. “C” ii. “U” iii. “V” iv. “L” v. Circular vi. Spiral vii. Oval viii. Elliptical xi. Square x. Triangular xi. Other xii. Square
5. Corner Pieces (eliminates necessity of beveling trim/bulb):
a. Material:
i. Plastic ii. Rubber iii. Metal vi. Identical to bulb v. Identical to trim vi. Combined bulb material and trim and clip material vii. Other
b. Shape (cross-section)
i. Identical with bulb only ii. Identical with trim only iii. Identical with combined trim and bulb vi. Larger than trim, bulb, or combination v. Smaller than trim, bulb, or combination vi. Exemplifying aesthetic of building vii. Other
6. Stiffeners (applied at panel edges to improve overall panel stiffness)
a. Material:
i. Plastic ii. Rubber iii. Metal vi. Other v. None
b. Shape:
i. “C” ii. “U” vi. “L” v. Open Circular vi. Open Spiral vii. Open Triangular viii. Open Square ix. Other
Any variations of the teachings above are also meant to be covered and protected by this current application.
|
Described are a new type of storm windows, along with an easy way (and less expensive) of installing the press-fit storm window, on existing frames or windows, without the hassle and expense of replacing the whole window (to save time, cost, and inconvenience), to increase R-value (insulation efficiency) for the windows (i.e. reduce energy waste). This relates to the construction and installation and use of easily installed low cost interior or exterior storm windows, which are attractive and effective in reducing heat and noise transmission. Different approaches and variations to implement this are shown here.
| 4
|
FIELD OF THE INVENTION
The present invention relates to paper interleavers for sheet metal and, in particular, to a paper interleaver capable of withstanding temperatures approaching 200° C. for prolonged periods of time.
BACKGROUND OF THE INVENTION
Recent capital expansion and upgrades in sheet metal mills have produced reducing mills which run faster and can take larger reductions in the sheet metal thickness during each pass. These passes are done in rapid succession, building up a high level of thermal energy in the sheet metal which is wound into coils without allowing much heat to dissipate.
According to conventional practice, an interleaver is typically co-wound into the windings of a sheet metal roll between the metal layers. The interleaver remains in contact with the sheet metal up to a week or more until the coil is fed into the cold annealing and pickling line wherein the interleaver is wound out of the coil.
The increased production rates achieved in many sheet metal mills have resulted in wound sheet metal temperatures as high as 200° C. at the point the interleaver is introduced into the coil. At these temperatures, the natural kraft and laminated papers which have been used as interleavers in the past often do not perform satisfactorily, exhibiting thermal degradation and adhesion to the sheet metal which causes clouding or surface roughness on the metal. This adds cost to the process because the metal has to be further processed to remove the surface damage.
Because of these effects, many sheet metal mills have had to either slow down the process or add more oil to cool the sheet metal and to aid in release of the paper from the sheet metal. Each of these options adds cost to the process.
Japanese Patent No. 18199 describes a heat resistant laminated paper for use as an interleaver for sheet metal. The laminated paper contains 0.5 to 5.0 weight percent based on the weight of the pulp of a synthetic resin formed from polyacrylamide, urea and melamine. The heat resistance of the paper may be further improved by adding dicyandiamide to the paper. A significant disadvantage associated with the use of such resins is that they contain or result in release of formaldehyde, which is a respiratory irritant and a possible carcinogen. In addition, the use of dicyandiamide in the United States is restricted due to heath concerns and the material is expensive.
Many types of silicone coatings have been described for application to paper to improve various properties of the paper. U.S. Pat. No. 4,954,554 describes an aqueous polysiloxane emulsion which comprises a polyvinyl alcohol component as an emulsifying agent. The polysiloxane emulsion composition contains an organopolysiloxane bearing silicone-bonded curing radical selected from the group consisting of hydroxyl radicals and olefinic radicals, a polyvinyl alcohol emulsifying agent and water. The radicals of the curable organopolysiloxane include hexenyl radicals. Curing of the organopolysiloxane is achieved using a cross linking agent such as organoxhydrogenpolysiloxane.
U.S. Pat. No. 2,774,674 describes treatment of kraft paper with organopolysiloxanic oils to provide heat resistance and release properties. The organopolysiloxanic oils are prepared as an aqueous dispersion containing a mineral filler, an emulsifier and an alkali salt of an organosilane-triol. The organopolysiloxanic oils are polysiloxanes containing hydrocarbon groups such as alkyl, aryl, or aralkyl groups linked to a silicon atom and have a viscosity at 25° C. between 100 and 1000 centistoke.
U.S. Pat. Nos. 4,190,688 and 3,463,661 describe silicone release coatings which are cured with heat and a catalyst. The '661 patent describes the use of a release coating prepared from polyvinyl alcohol, silicone resin, acetic acid, a wetting agent and a tin octoate catalyst. The '688 patent describes the use of a release coating prepared from a vinyl-containing siloxane polymer having hydroxy end groups. The polysiloxane polymer of the '688 patent is emulsified in water with polyvinyl alcohol with or without an organic solvent and a hydride polysiloxane cross-liking agent is used along with a tin or platinum catalyst at elevated temperatures to cure the coating.
Although the coatings described in the above patents have provided various improvements in paper properties, the high temperatures to which interleavers are exposed in modern sheet metal manufacturing coupled with the increased amount of oil used to address blocking problems has created a need for a further improved economical paper-based interleaver which will perform satisfactorily under these conditions. Standard coated paper grades with silicone-type coatings are relatively expensive and therefore do not adequately address this need, and formaldehyde-containing additives generally will not be accepted for environmental reasons.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a paper interleaver for sheet metal.
Another object of the invention to provide a paper interleaver for sheet metal which can withstand temperatures approaching 200° C. for prolonged periods.
It is also an object of the invention to provide a paper interleaver for sheet metal which exhibits limited adherence to the sheet metal, does not damage or disaffect the metal surface and does not cause the sheet metal to discolor or corrode.
A further object of the invention is to provide a paper interleaver for sheet metal which exhibits good absorbency with respect to residual oil used to cool and lubricate the sheet metal and manufacturing equipment.
An additional object of the invention is to provide a paper interleaver for sheet metal wherein the paper does not require a coating and the manufacture of the paper does not present health risks to workers.
Yet another object of the invention is to provide a paper interleaver of the character described and a method of making the same which is economical and cost effective as compared with conventional interleavers.
With regard to the foregoing and other objects, the invention provides a paper interleaver for placement between layers of sheet metal. The interleaver comprises a porous fibrous web containing from about 0.1 to about 5 weight percent of a catalytically cross-linked polysiloxane dispersed generally through the thickness of the web.
According to another aspect the invention provides a method of making a paper interleaver for placement between layers of sheet metal, said method comprising impregnating a porous fibrous web at a section of a paper making process wherein the web has a moisture content of from about 5 to about 15 weight percent with a polysiloxane/crosslinker emulsion and a polysiloxane/catalyst emulsion and thereafter curing the web to cause the polysiloxanes to cross-link and drying the web whereby a catalytically cross-linked polysiloxane is cured in the web dispersed generally through the thickness of the web.
An additional aspect of the invention comprises a method of storing an elongated sheet of metal at an elevated temperature which comprises winding the sheet metal into a roll to provide spirally wound adjacent layers of sheet metal, co-winding an elongated paper interleaver with the elongated sheet metal so that the paper interleaver is spirally wound in the roll between the adjacent layers of spirally wound sheet metal, wherein the paper interleaver comprises a porous fibrous web containing from about 0.1 to about 5 weight percent interleaver of a catalytically cross-linked polysiloxane dispersed generally through the thickness of the web. A further aspect of the invention is the spirally wound roll of sheet metal with the paper interleaver wound between adjacent layers of sheet metal.
The paper interleaver of this invention withstands temperatures approaching 200° C. for prolonged periods and exhibits reduced adhesion to the sheet metal reducing damage to the surface of the sheet metal associated with use of conventional interleavers. Discoloration and corrosion of the metal is also reduced using the interleaver of the invention. In addition, the interleaver protects the sheet metal from scratching, absorbs residual oil from the sheet metal and provides a means for dissipating the heat of the sheet metal. Also, the manufacture of the paper does not present health risks to workers and the paper can be produced in an economical manner.
DESCRIPTION OF THE INVENTION
This invention provides an improved paper interleaver for wound rolls of sheet metal. The paper interleaver is placed between layers of sheet metal to physically separate the adjacent layers of metal and to protect the metal surfaces when the sheet metal is rolled, cleaned, transported and warehoused.
The paper interleaver is prepared from a porous fibrous web which can be produced using conventional papermaking methods and machines. A wide variety of sources of fibers may be used such as flax, bagasse, esparto, straw, papyrus, bamboo, jute, softwoods, hardwoods, and synthetic fibers. Examples of softwoods include spruce, hemlock, fir and pine. Examples of hardwoods include popular, aspen, birch, maple and oak.
The porous fibrous web is relatively thin, essentially planar or flat and has substantially parallel, oppositely facing surfaces spaced apart by the thickness of the web. Such a web is a three dimensional structure comprised of a network of fibers with interstices therebetween. The fibers can be a mixture of relatively short and relatively long fibers of natural or synthetic origin. Mixtures of natural fibers and synthetic fibers can also be used. Examples of natural fibers include cotton, wool, silk, jute, linen, and the like. Examples of synthetic fibers include rayon, acetate, polyesters (including polyethyleneterephthalate), polyamides (including nylon), acrylics, olefins, aramids, azlons, glasses, modacrylics, novoloids, nytrils, rayons, sarans, spandex, vinal, vinyon, and the like.
The porous fibrous web may additionally include one or more additives. Suitable additives include wet end chemicals, wet strength chemicals, sizes such as rosin size, biocides, thickeners, inhibitors, reinforcing agents, fillers, defoamers, and flame retardants. Combinations of additives may also be used.
Preferred wet strength chemicals are aqueous-based solutions of polyacrylamide, urea, melamine and polyamideepichlorohydrin resin. Preferred wet end chemicals are polyaluminum hydroxychloride, polyaluminum silicate sulfate, aluminum sulfate, bentonite, colloidal silica, soda ash, clay, starch, titanium dioxide, and calcium carbonate. It is noted that fillers may be excluded from paper prepared by the process of the present invention in order to increase the absorbency of the paper.
In accordance with the invention, the porous fibrous web contains a catalyzed polysiloxane dispersed generally throughout the thickness of the web. By "catalyzed crosslinked polysiloxane" it is meant a crosslinked polysiloxane which is produced by impregnating the web substantially uniformly through its thickness with a polysiloxane/crosslinker emulsion and a polysiloxane/catalyst emulsion. The polysiloxane emulsions are applied to the porous fibrous web as a two part system hereinafter referred to as a polysiloxane emulsion system.
Preferably, the polysiloxane/crosslinker emulsion comprises from about 20 to about 50 weight percent of a polysiloxane, from about 0.1 to about 5 weight percent of a hydride polysiloxane cross linking agent, from about 1 to about 5 weight percent of a surfactant, and from about 50 to about 80 weight percent water. A preferred polysiloxane is hexenyl substituted or vinyl substituted such as dimethyl, methyl-hexenyl terminated polysiloxane or vinyl-dimethyl terminated polysiloxane. A preferred surfactant is polyvinyl alcohol (PVA). The hydride polysiloxane cross linking agent is selected from a hydride containing diorganopolysiloxane polymer of 1 to 250 centipoise viscosity at 25° C., a hydride resin composed of monofunctional siloxy units and tetrafunctional siloxy units, or a hydride siloxy resin composed of monofunctional siloxy units, tetrafunctional siloxy units and difunctional siloxy units.
Most preferably, the polysiloxane/crosslinker emulsion comprises from about 35 to about 41 weight percent dimethyl, methyl-hexenyl terminated polysiloxane, from about 0.1 to about 5 weight percent dimethyl, methylhydrogen siloxane, from about 0.1 to about 5 weight percent vinyl alcohol-vinyl acetate copolymer, from about 0.1 to about 5 weight percent polyvinyl alcohol and from about 55 to about 65 weight percent water.
Preferably, the polysiloxane/catalyst emulsion comprises from about 20 to about 50 weight percent of a polysiloxane, from about 0.001 to about 5 weight percent of a catalyst, from about 0.1 to about 5 weight percent surfactant and from about 50 to about 80 weight percent water. Most preferably, the polysiloxane/catalyst emulsion comprises from about 30 to about 40 weight percent dimethyl siloxane, from about 0.1 to about 5 weight percent tetra methyl tetravinyl cyclotetrasiloxane, from about 0.1 to about 5 weight percent vinyl alcohol-vinyl acetate copolymer, from about 0.005 to about 2 weight percent platinum or a platinum-containing catalyst, and from about 55 to about 65 weight percent water.
The platinum or platinum-containing catalyst includes solutions or complexes of chloroplatinic acid in alcohols, ethers, divinylsiloxanes and cyclic vinyl siloxanes. A preferred tin salt of a carboxylic acid is dibutyltindilaurate. It is within the scope of the invention to use a tin salt of a carboxylic acid as a catalyst in place of or in conjunction with the platinum catalyst. Both the platinum and tin catalyst can be activated at elevated temperatures or by radiation.
The viscosity of the polysiloxane emulsion system should be low enough to enable the polysiloxane emulsion system to penetrate the interstices of the porous fibrous web. A preferred viscosity is from about 10 centipoise to about 500 centipoise measured at a shear rate of 10 reciprocal seconds at 25° C. More preferably, the viscosity of the polysiloxane emulsion system is from about 20 to about 100 centipoise.
The polysiloxane emulsion system may carry additives as listed above into the porous fibrous web. An especially preferred additive is a non-volatile inhibitor which limits premature curing of the polysiloxane emulsion system.
The polysiloxane emulsion system is preferably applied to both sides of the porous fibrous web in a manner so as to fully saturate the web at a point in the papermaking process wherein the web has a moisture content of from about 5 to about 15 weight percent. More preferably, the porous fibrous web comprises about 6 to about 9 weight percent of water when the polysiloxane emulsion system is applied.
It is a feature of the invention that the porous fibrous web is impregnated with the polysiloxane emulsion system. As used herein, "impregnate" refers to the substantially complete penetration of the polysiloxane emulsion system into and through the porous fibrous web, and to the distribution of the polysiloxane emulsion system in a preferably substantially uniform, manner in the web. The polysiloxane emulsion system preferably envelopes, surrounds, and/or impregnates individual fibers within the porous fibrous web. The polysiloxane emulsion system is also present on the surface of the porous fibrous web, but is preferably not substantially concentrated on the surface. In this manner, the web is heat stabilized substantially uniformly through its thickness in contrast with a coated web wherein the material is concentrated on the web surfaces as a layer. Applying the material to the web on the papermaking machine prior to the final drying step enables enhanced infusion of the agents into the fiber web because the web is still relatively open and porous and will consolidate and close to a substantial degree in final drying and calendering operations.
The quantity of the polysiloxane emulsion system absorbed and the penetration of the polysiloxane emulsion system in the porous fibrous web depends on the moisture content of the porous fibrous web, the percent solids of the polysiloxane emulsion system, the nip pressure applied to the porous fibrous web, and the viscosity of the polysiloxane emulsion system.
Suitable means of applying the polysiloxane emulsion system on a paper machine are by size press, blade coater and speedsizer. Preferred size press configurations include a flooded nip size press and a metering blade size press. The nip pressure at the size press controls the metering of the polysiloxane emulsion system onto the porous fibrous web. Suitable means of applying the polysiloxane emulsion system on off-machine coating equipment are by rod, gravure roll and air-knife. The polysiloxane emulsion system may also be sprayed directly onto the porous fibrous web or onto rollers which transfer the polysiloxane emulsion system to the porous fibrous web.
In one embodiment of the invention, the impregnation of the porous fibrous web with the polysiloxane emulsion system occurs at the nip point between two rollers. The polysiloxane emulsion system preferably is applied to both rollers but may be applied to only one roller.
Upon exiting the size press, the moisture content of the porous fibrous web which is impregnated with the polysiloxane emulsion system will generally be about 20 to about 40 weight percent water, and will preferably be about 25 to 35 weight percent water. The porous fibrous web is then heated to evaporate water and to cure the polysiloxane emulsion system. Alternatively, or in addition to conventional drying methods, the web impregnated with the polysiloxane emulsion system may be radiation cured.
Once dried and cured, the porous fibrous web impregnated with the cured polysiloxane emulsion system provides an improved paper interleaver. The weight of the paper interleaver is preferably from about 15 to about 45 pounds per 3,000 square feet of paper. More preferably, the weight of the paper interleaver is from about 30 to about 35 lbs/3,000 ft 2 of paper. The amount of the polysiloxane emulsion system in the paper interleaver after final drying and calendaring is preferably from about 0.5 to about 5 weight percent based on the total weight of the paper. It is within the scope of the invention to have greater than 5 weight percent of the polysiloxane emulsion system in the paper interleaver in order to achieve acceptable heat resistance, however, such higher amounts may not be cost effective. More preferably, the polysiloxane emulsion system is present in the paper interleaver after final drying and calendaring in an amount of from about 1.5 to about 3.5 weight percent based on the total weight of the paper.
The paper interleaver of the invention withstands temperatures approaching 200° C. without charring or depositing materials on the sheet metal. The paper interleaver protects sheet metal and prevents metal to metal contact which may result in scratching or deformation of the sheet metal. The paper interleaver also exhibits improved absorption of residual oil used as a lubricant in the manufacturing of sheet metal. Residual oil on the sheet metal is disadvantageous because the oil leaves a white residue on the sheet metal.
The following nonlimiting examples illustrate further aspects of the invention.
EXAMPLE 1
Coatings were applied by means of a wire wound rod to a 30# unbleached MF neutral sheet of paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, and 0.1% soda ash. The coatings were applied to the paper samples after final drying and calendaring of the paper. The samples and coating compositions are identified in Table I.
TABLE I______________________________________Sample Coating Composition______________________________________1 1% solution of polyacrylamide (0.4 lbs./3000 ft.sup.2).2 1% solution of polyacrylamide + 0.5% solution of dicyandiamide mixed at a 1:10 weight ratio, respectively (total chemical wt. 0.7 lbs./3000 ft.sup.2).3 1% solution of polyacrylamide + 0.5% solution of dicyandiamide mixed at a 1:10 weight ratio, respectively (total chemical wt. 1.2 lbs./3000 ft.sup.2).4 1% of a solution containing 7% by wt. polyacrylate (1.3 lbs./3000 ft.sup.2).5 1% of a solution containing 10% by wt. polyacrylate (1.3 lbs./3000 ft.sup.2).6 1% of a solution containing 10% by wt. of polyacrylate + 0.5% solution of dicyandiamide (total chemical wt. 1.0 lbs./3000 ft.sup.2).______________________________________
Each sample was sandwiched between two stainless steel plates of a Carver Model 2518 press at a temperature of 200° C. and a pressure of 350 psi for 24 hours and the release property was determined. The samples were tested with and without being saturated with mineral oil which was applied by dipping the samples into the oil.
All of the samples (both with and without mineral oil) stuck significantly to the steel plates of the press and the paper became discolored (charred) and brittle. Thus, these coatings did not provide acceptable release properties.
EXAMPLE 2
The heat stability/release properties of several paper samples were evaluated. Sample 1 was a 30# unbleached MF neutral sheet of paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, and 0.1% soda ash. Samples 2 and 3 were 30# unbleached MF neutral sheets of paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, 0.1% soda ash, and 1% polyacrylamide. Samples 1-3 were not coated with dicyandiamide. Sample 4 was similar to Sample 3 but was coated with a 2.5% solution of dicyandiamide by means of a wire wound rod. The polyacrylamide in Samples 2, 3 and 4 was added as a wet end chemical in the papermaking process. The samples are identified in Table II. (Reel 1 and Reel 2 refer to different reels of paper.)
TABLE II______________________________________Sample Paper Interleaver Coating______________________________________1 30# MF unbleached paper No Coating2 30# MF unbleached paper having 1 wt. % polyacrylamide (reel 1) No Coating3 30# MF unbleached paper having 1 wt. % polyacrylamide (reel 2) No Coating4 30# MF unbleached paper having 1 wt. % polyacrylamide (reel 2) dicyandiamide______________________________________
The release properties for Samples 1-4 with and without mineral oil were determined by the procedure set forth in Example 1. The test results are summarized in Table III.
TABLE III______________________________________ Color/ Color/ Release Charring Release CharringSample (w/o oil) (w/o oil) (w/oil) (w/oil)______________________________________1 Stuck to Some Stuck to Some steel plate steel plate (worst one)2 Stuck Some Stuck Some slightly to slightly to steel plate steel plate3 Stuck Some Stuck Some slightly to slightly to steel plate steel plate4 Stuck Some Stuck Some slightly to slightly to steel plate steel plate______________________________________
The test results in Table III show that all of the samples stuck to the steel plates of the press and the paper became discolored (charred). The presence of mineral oil did not prevent the samples from sticking to the steel plates.
EXAMPLE 3
The release properties of several paper samples were evaluated. Sample 1 was 30# unbleached MF neutral sheet of paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, 0.1% soda ash, and 1% polyacrylamide. Samples 2-6 were 30# unbleached MF neutral paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, and 0.1% soda ash.
A coating was applied to Samples 2-6 with a wire wound rod after final drying and calendaring of the paper. The coating compositions are listed in Table IV. Sample 5 was coated with a polysiloxane/crosslinker emulsion (40% solids) and a polysiloxane/catalyst emulsion (40% solids) which are commercially available under the trademarks SYL-OFF 1171 and SYL-OFF 1171A, respectively, from Dow Corning in Midland, Mich. Sample 6 was coated with a polysiloxane/crosslinker emulsion and a polysiloxane/catalyst emulsion which are commercially available under the trademarks SYL-OFF 7910 and SYL-OFF 7924, respectively, from Dow Corning in Midland, Mich. The emulsions are described in Table IV.
TABLE IV______________________________________Sample Coating Composition______________________________________1 2.5% solution of dicyandiamide (1.5 lbs./3000 ft.sup.2).2 2.5% solution of dicyandiamide + 22% solution of polyacrylamide mixed at a 10:1 weight ratio, respectively (total chemical wt. 1.75 lbs./3000 ft.sup.2).3 Polystyrene latex + urea formaldehyde + water in a weight ratio of 2 0:8:72, respectively (total chemical wt. 1.5 lbs./3000 ft.sup.2).4 Polystyrene latex + polysiloxane/ crosslinker emulsion + water in a weight ratio of 20:4:76, respectively (total chemical wt. 1.5 lbs./3000 ft.sup.2).5 Polysiloxane/crosslinker emulsion and a polysiloxane/tin catalyst emulsion + water in a weight ratio of 18:2:80, respectively (total chemical wt. 1.75 lbs./3000 ft.sup.2).6 Polysiloxane/crosslinker emulsion and a polysiloxane/platinum catalyst emulsion + water in a weight ratio of 15:1:84, respectively (total chemical wt. 1.75 lbs./3000 ft.sup.2).______________________________________
Each sample was sandwiched between two stainless steel plates of a Carver Model 2518 press at a temperature of 180° C. and a pressure of 850 psi for 14 hours and the release properties and degree of charring were determined. The samples were tested with and without being saturated with mineral oil. The test results are summarized in Table V.
TABLE V______________________________________ Color Color/ Release Charring Release CharringSample w/oil w/oil w/oil w/oil______________________________________1 Poor Acceptable Poor Good2 Poor Acceptable Poor Acceptable3 Acceptable Poor Acceptable Poor4 Acceptable Good Acceptable Good5 Good Good Good Good6 Good Good Good AcceptableRelease Properties:Poor = stuck to steel plate, fibers left on plate;Acceptable = removed from steel plate with use of razor blade, no fibers left;Good = removed from steel plate after starting corner with razor blade.Color/Charring Properties:Poor = high degree of darkening of fibers, very brittle;Acceptable = some darkening of fibers, some brittleness;Good = minimal darkening of fibers and minimal loss of strength of paper.______________________________________
The test results in Table V show that Samples 5 and 6 which were coated with a platinum or tin catalyst containing polysiloxane emulsion did not stick to the steel. It is important to note that the polysiloxane emulsion in Samples 5 and 6 was applied as a coating after final drying and calendaring of the paper. The other samples coated with dicyandiamide; dicyandiamide and polyacrylamide; polystyrene latex, urea formaldehyde; polystyrene latex and polysiloxane emulsion, respectively, stuck to the steel plates and exhibited unacceptable charring.
EXAMPLE 4
The release properties of several paper samples were evaluated. Sample 1 was a 25.8# commercially available unbleached MF neutral paper made with dicyandiamide. Sample 1 was not coated. Sample 2 was a 30# unbleached MF neutral paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, 0.1% soda ash, and 1% polyacrylamide. Samples 3-7 were 30# unbleached MF neutral paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, and 0.1% soda ash. The samples and weight percent coating compositions are listed in Table VI.
TABLE VI______________________________________Sample Coating Composition______________________________________1 No Coating.2 2.5% solution of dicyandiamide (1.5 lbs./3000 ft.sup.2).3 2.5% solution of dicyandiamide + 22% solution of polyacrylamide mixed at a 10:1 weight ratio, respectively (total chemical wt. 1.75 lbs./3000 ft.sup.2).4 Polystyrene latex + urea formaldehyde + water in a weight ratio of 20:8:72, respectively (total chemical wt. 1.5 lbs./3000 ft.sup.2).5 Polystyrene latex + polysiloxane/crosslinker emulsion + water in a weight ratio of 20:4:76, respectively (total chemical wt. 1.5 lbs./3000 ft.sup.2).6 Polysiloxane/crosslinker emulsion + polysiloxane/tin catalyst emulsion + water in a weight ratio of 18:2:80, respectively (total chemical wt. 1.75 lbs./3000 ft.sup.2).7 Polysiloxane/crosslinker emulsion + polysiloxane/platinum catalyst emulsion + water in a weight ratio of 15:1:84, respectively (total chemical wt. 1.75 lbs./3000 ft.sup.2).______________________________________
Each sample was sandwiched between two stainless steel plates of a Carver Model 2518 press at a temperature of 180° C. and a pressure of 850 psi for 14 hours and the release property and degree of charring were determined. The samples were tested with and without being saturated with mineral oil. The test results are summarized in Table VII.
TABLE VII______________________________________ Color/ Color/ Release Charring Release CharringSample (w/o oil) (w/o oil) (w/oil) (w/oil)______________________________________1 Good Good Fair Fair2 Fair Poor Poor Poor3 Fair Fair Poor Poor4 Poor Poor Fair Poor5 Good Good Very good Very good6 Poor Fair Very good Good7 Fair Poor Fair Fair______________________________________
Paper was prepared as above and coated with the coating compositions for Samples 5-7 and evaluated in a Carver Model 2518 press at a temperature of 190° C. and a pressure of 850 psi for 24 hours and the release property and degree of charring were determined. The samples were tested with and without being saturated with mineral oil. The test results are summarized in Table VIII.
TABLE VIII______________________________________ Color/ Color/ Release Charring Release CharringSample (w/oil) (w/oil) (w/oil) (w/oil)______________________________________5 Good Good Very good Very good6 Poor Fair Very good Good7 Fair Poor Fair Fair______________________________________
The test results in Tables VII and VIII show that paper samples coated with the polysiloxane/crosslinker emulsions and polysiloxane/catalyst emulsions outperformed the other coated samples and exhibited good release properties without charring at a press temperature of 180° C. for 14 hours. However at a press temperature of 190° C. for 24 hours, the paper samples coated with the polysiloxane/crosslinker emulsions and polysiloxane/catalyst emulsions stuck somewhat to the steel plates and exhibited some charring.
EXAMPLE 5
The release properties of coated paper samples were evaluated. Sample 1 was 30# unbleached MF neutral paper made from 20% hardwood and 80% softwood and contained 0.5% alum,0.4% rosin size, 0.2% polyacrylamide, and 0.5% dicyandiamide, based on fiber weight. In Sample 1, the polyacrylamide and dicyandiamide were added at the size press in the papermaking process. Samples 2 and 3 were 30# unbleached MF neutral paper made from 20% hardwood and 80% softwood and contained 0.5% alum, and 0.4% rosin size, based on fiber weight. Coatings which are described in Table IX were applied to Samples 2 and 3 on a pilot plant size press.
TABLE IX______________________________________Sample Coating Composition______________________________________1 No Coating2 Polysiloxane/crosslinker emulsion + polysiloxane/tin catalyst emulsion + water in a weight ratio of (18:2:80) to provide a total chemical wt. on paper of 0.6 lbs./3000 ft.sup.2.3 Polysiloxane/crosslinker emulsion + polysiloxane/platinum catalyst emulsion + water in a weight ratio of (15:1:84) to provide a total chemica1 wt. on paper of 0.6 lbs./3000 ft.sup.2.______________________________________
Each of the paper samples was interleaved into at least one stainless steel coil following the last reduction pass at a rolling mill. The temperature of the steel was raised higher than normal to subject the paper to temperature conditions as hot as possible.
After 18 hours, the paper was wound out at the cold annealing & pickling line. The release properties of coated paper samples were evaluated. The test results are summarized in Table X.
TABLE X______________________________________ Temp. of Steel When Paper is Paper Stick OtherSample Interleaved to Steel Comments______________________________________1 107° C. No Very brittle, many breaks in paper while unwinding steel.1 127° C. No Very brittle, many breaks in paper while unwinding steel.2 127° C. No Brittleness, some breaks in paper while unwinding steel.3 138° C. No Brittleness, some breaks in paper while unwinding steel.______________________________________
The test results in Table XI show that the paper coated with the polysiloxane/crosslinker emulsions and polysiloxane/catalyst emulsions and the uncoated paper manufactured with polyacrylamide and dicyandiamide did not stick to the steel plates at temperatures of 107° C. to 138° C. However, the uncoated paper manufactured with dicyandiamide and polyacrylamide exhibited excessive brittleness.
EXAMPLE 6
The release properties of three different paper samples were evaluated. Sample 1 was 30# unbleached MF neutral paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, and 0.3% polydimethylsiloxane emulsion without a catalyst. The weight percentages are based on fiber weight. The polydimethylsiloxane emulsion was applied to both sides of the porous fibrous web in Sample 1 in the papermaking process after the first dryer unit and prior to the size press.
Sample 2 was 30# unbleached neutral extensible paper having microcrepes which was made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, and 0.3% polydimethylsiloxane emulsion without a catalyst. The weight percentages are based on fiber weight. The polydimethylsiloxane emulsion was applied to one side of the porous fibrous web in Sample 2 in the papermaking process after the first dryer unit and prior to the size press.
Sample 3 was the same as Sample 1 except that the polydimethylsiloxane emulsion was applied to only one side of the porous fibrous web.
The paper samples were wound into a steel coil following the last pass at the reducing mill. The temperature of the steel is listed in Tables XII and XIII. After approximately 20 hours, each of the paper samples was wound out at the cold annealing and pickling line and evaluated. Additional mineral oil was applied to some steel coils for the first evaluation but not for the second evaluation. The test results for the first evaluation are summarized in Table XII and for the second evaluation in Table XIII.
TABLE XII______________________________________ Steel Temp. Paper as Paper is Sticking to OtherSample Interleaved Steel Comments______________________________________1 152° C. No Extra oil at reducing mill used to aid release.1 124° C. No Paper was slightly brittle, a few breaks.2 171° C. Yes Failure--paper stuck to steel plus very brittle.2 132° C. No Extra oil at reducing mill used to aid release.3 149° C. No Extra oil at reducing mill used to aid release.3 143° C. No Paper did not stick to steel and no break.______________________________________
TABLE XIII______________________________________ Steel Temp. Paper as Paper is Sticking to OtherSample Interleaved Steel Comments______________________________________1 132° C. Yes Failure--paper stuck to steel.1 116° C. No OK2 141° C. Yes Failure--paper stuck to steel for most of coil.2 110° C. No OK3 121° C. No OK3 138° C. Yes Failure--paper stuck to steel and was brittle.______________________________________
The test results in Tables XII and XIII show that paper made by applying a noncatalyst containing polydimethylsiloxane emulsion to the porous fibrous web in the papermaking process does not provide heat resistance at temperatures above 141° C. It is noted that the addition of extra mineral oil to the steel coils in the first evaluation aided in release of the paper from the steel but did not completely eliminate sticking of the paper to the steel.
EXAMPLE 7
The release properties of five different paper samples were evaluated. Sample 1 was 30# unbleached MF neutral paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, and 0.3% polydimethylsiloxane emulsion without a catalyst which was applied to both sides of the porous fibrous web in the papermaking process after the first dryer unit and prior to the size press. The weight percentages are based on fiber weight.
Sample 2 was a 25.8# unbleached MF neutral commercially available paper manufactured with dicyandiamide.
Sample 3 was 30# unbleached MF neutral paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, and 1.0% polysiloxane/crosslinker emulsion and polysiloxane/platinum catalyst emulsion which was applied to both sides of the porous fibrous web in the papermaking process after the first dryer unit and prior to the size press. The weight percentages are based on fiber weight.
Sample 4 was 30# unbleached MF neutral paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, and 1.0% polysiloxane/crosslinker emulsion and polysiloxane/platinum catalyst emulsion which was applied to both sides of the porous fibrous web in the papermaking process at the size press. The weight percentages are based on fiber weight.
Sample 5 was 30# unbleached MF neutral paper made from 20% hardwood and 80% softwood which contained 0.5% alum, 0.4% rosin size, and 3.3% polysiloxane/crosslinker emulsion and polysiloxane/platinum catalyst emulsion which was applied to both sides of the porous fibrous web in the papermaking process at the size press. The weight percentages are based on fiber weight.
The release and charring properties of the paper samples were evaluated. Each paper sample was placed in a hot press at a temperature of 200° C. and a pressure of 850 psi for 24 hours. Each paper sample was tested with and without being saturated with mineral oil. The test results for two evaluations are summarized in Tables XIII and XIV.
TABLE XIII______________________________________ Release Color/Charring Release Color/CharringCoating (w/oil) w/oil) (w/o oil) (w/o oil)______________________________________1 very good good good good1 very good fair good fair2 very good good very good good2 very good good very good good3 good fair very good good3 very good fair very good good4 very good good very good good4 very good good very good good5 very good good very good good5 very good good very good good______________________________________
TABLE XIV______________________________________ Release Color/Charring Release Color/CharringCoating (w/oil) w/oil) (w/o oil) (w/o oil)______________________________________1 good good good good1 good good good fair2 good good good good2 very good fair good good3 good good fair good3 good fair good good4 good fair fair fair4 good fair good good5 very good fair good good5 good fair good good______________________________________
The test results in Tables XIV and XV show that the paper samples impregnated in the papermaking process with the polysiloxane/crosslinker emulsion and polysiloxane/platinum catalyst emulsion provided very good release properties and resisted charring much more consistently than the uncoated paper samples or paper samples impregnated with a polydimethylsiloxane emulsion without a catalyst. Moreover, the paper samples impregnated in the papermaking process with the polysiloxane/crosslinker emulsion and polysiloxane/platinum catalyst emulsion did not require additional mineral oil in order to exhibit very good release from the steel plates. No significant difference was observed between the paper samples containing the different amounts of polysiloxane/crosslinker emulsion and polysiloxane/platinum catalyst emulsion.
EXAMPLE 8
Samples 4 and 5 from Example 7 which were impregnated with the polysiloxane/crosslinker emulsion and polysiloxane/platinum catalyst emulsion were wound into spirally wound steel coils following the last pass at the reducing mill and evaluated for release and brittleness. The paper samples remained in the coil for about 20 hours before being wound out at the cold annealing and pickling line. No additional lubricating oil was applied to the coils prior to contact with the paper samples. The test results are summarized in Table XV.
TABLE XV______________________________________ Steel Temp. Paper as Paper is Sticking OtherSample Interleaved to Steel Comments______________________________________4 160° C. No Brittle paper, many breaks at cold A&P4 160° C. No Brittle paper, many breaks at cold A&P4 166° C. Yes Failure--paper stuck to steel5 149° C. No OK5 166° C. No Brittle paper, many breaks at cold A&P______________________________________
The test results in Table XV show that Sample 5 which was impregnated in the papermaking process with the polysiloxane/crosslinker emulsion and polysiloxane/platinum catalyst emulsion in an amount of 3.3 weight percent did not stick to the steel plates even at a temperature as high as 166° C. Moreover, Sample 5 did not give any indication that it would stick to the steel even at higher temperatures.
Sample 4 which was impregnated in the papermaking process with the polysiloxane/crosslinker emulsion and polysiloxane/platinum catalyst emulsion in an amount of 1.0 weight percent did not stick to the steel plates at a temperature of 160° C. but did stick to the steel plates at a temperature of 166° C. It is noted that a temperature of greater than 166° C. could not be attained for these particular steel plates.
While the invention has been described with particular reference to certain embodiments thereof, it will be understood that changes and modifications may be made by those of ordinary skill in the art within the scope and spirit of the following claims.
|
The present invention relates to paper interleavers for sheet metal and, in particular, to a paper interleaver containing catalytically crosslinked polysiloxane capable of withstanding temperatures approaching 200° C. for prolonged periods of time.
| 3
|
This application claims the benefit of the filing date of U.S. Provisional Application No. 60/810,891, filed Jun. 5, 2006. This application is related to a U.S. application Ser. No. 11/754,797, also entitled TRADING SYSTEM AND METHOD FOR INSTITUTIONAL ATHLETIC AND EDUCATION PROGRAMS, filed on May 29, 2007.
BACKGROUND OF THE INVENTION
The present invention relates generally to trading novel commodity options and futures contracts, and more particularly to a device and method for trading such contracts as they relate to athletic and education programs.
Education, particularly higher education, is the gateway to the American Dream. The long-term economic value of earning a college degree is well-documented. College-educated workers, on average, can bring home more than $1 million more over a lifetime than people who end their formal education after high school.
Though benefits of a post-secondary degree are undeniable, consumers of higher education (students and families) have to find a way to cover the price of education before the benefits can be realized. During the past two decades, the price of education in the United States has increased dramatically and at a rate approximately twice the rate of inflation. Between 1980 and 2001, spending at public colleges and universities increased by almost seventy five percent, after accounting for inflation, to over one hundred and thirty five billion dollars.
In addition, student debt obligations have risen dramatically. The average debt fourth year-students at public four-year colleges have accumulated has risen thirty nine percent to over fifteen thousand dollars since 1993. The average debt fourth year-students at private four-year colleges have accumulated has risen forty nine percent to over twenty three thousand dollars since 1993.
In 2005, there were approximately four thousand degree-granting colleges and universities in the United States. In October of 2005, according to the U.S. Department of Labor, there were eleven million sixteen to twenty-four year-olds enrolled in colleges in the United States. This disparity between the supply of and demand for education means that while education is one of the best investments an individual can make, the price risk of education is difficult to hedge because there are many more buyers of education (i.e., students and families) than there are sellers (i.e., colleges and universities). The difficulty related to hedging the price risk of education demonstrates that there is a clear and pressing need for the current invention.
Like the price of education, the price of producing educational athletics, particularly collegiate athletics, in the United States has increased dramatically in the past two decades. At the collegiate level, the amount of revenue that most institutions must allocate from academic resources to balance athletic budgets is increasing. Recent research indicates that the rate of increase in athletic expenditures is tripling that of spending in higher education overall. In other words, the price of athletics is increasing at the equivalent of six times the rate of inflation. It has recently been reported that athletic programs at public institutions receive more than one billion dollars in student fees and general school funds and services. Without outside funding, fewer than ten percent of athletic departments would have been able to support themselves with ticket sales, television contracts and other revenue-generating means. Most of these institutions would have lost more than five million dollars in a single year. Thus, it is clear that the price of athletics is sympathetic with the price of education.
Athletics and education and the business of athletics and education, particularly the business of collegiate athletics, has experienced revenue growth in recent years. Assets related to athletic programs and education programs often generate millions of dollars in revenue. However, the athletic prospects who are the students that contribute to the generation of this revenue do not share in it. Rather, as documented in testimony before Congress in 2003, they often live in poverty. The risk of poverty to prospects who contribute to the generation of athletic revenue demonstrates that there is a clear and pressing need for the current invention.
Furthermore, institutions do not have adequate tools for managing economic risk related to athletic program assets and education program assets. For example, the president of the National Collegiate Athletic Association (NCAA) has publicly stated that Division I collegiate athletics “do[es] not have a sustainable business model” despite the fact that: (a) participating institutions generate millions of dollars via operation of their athletic programs that is not subject to taxation; (b) these institutions do not pay any wages to the athletes who contribute their physical efforts to generating the revenue; and (c) the majority of these institutions provide additional cash subsidies to athletic programs by charging fees to all students attending the institution. In addition, the chairman of the NCAA's Task Force on Fiscal Responsibility has stated that “the rate of growth of expenditures and revenues in intercollegiate athletics simply is not sustainable.” The former chairman of the NCAA's Division I Board of Directors has testified before the Knight Commission on Intercollegiate Athletics (Knight Commission) about the “inequity of the marketplace” for athletic prospects participating in collegiate athletics and has stated that higher education has not “been able to address how to use education as a commodity.” Finally, the former president of the Knight Commission has said that he does not believe that there will be a time when the NCAA or its members “do something so dramatic and wonderful that it really changes the situation.” These statements and findings demonstrate a clear and pressing need for the present invention.
In all collegiate athletic environments, one of the greatest risks to a program is the fierce competition among educational institutions to recruit and retain the most promising athletic prospects in order for an institution to maximize the chances of continuously maintaining an athletic program that is academically, athletically, and economically successful. At the collegiate level, during the off-season (i.e., that time of the year when an athletic program's teams are not engaged in on-field play with competing teams), an institution seeks to persuade desirable prospects to commit to attending that particular institution and participating in the institution's athletic program. Most or all institutions use a standardized contract known as a National Letter of Intent (NLI) to secure a prospect to the exclusion of other competing institutions. According to NCAA Bylaw 13.02.08, the NLI is “utilized by subscribing member institutions to establish the commitment of a prospect to attend a particular institution.”
The NCAA considers the NLI to be a binding agreement between a prospect and an institution in which the institution agrees to provide the prospect a grant-in-aid for one year in exchange for the prospect's agreement to attend the institution and participate in the designated athletic program for that year. The time periods for a prospect to sign an NLI vary by sport. For example, the NLI signing period for college football prospects is open from approximately December 21 through January 15 (for junior college prospects) and approximately February 1 through April 1 (for high school prospects). In the case of football, the prospect who signs an NLI typically delivers himself to the institution by the following July or August. The NLI is binding for a four-year term.
The NLI is a type of unregulated contract known as a forward contract that is similar, but not identical, to a regulated commodity futures contract (also known as a future). A traditional forward contract can be settled only by physical delivery of an underlying commodity and cannot be cash settled. In contrast to a forward contract, most transactions involving futures do not require the seller of the future to actually deliver the underlying commodity to the buyer. Instead, as the last trading date (known as the settlement date) approaches, the buyer and seller execute offsetting contracts, thereby exiting the market and taking a corresponding profit or loss. In other words, a futures contract can be cash settled. These attributes allow a futures contract to mimic the equivalent of real ownership of a commodity without either trader actually obtaining anything but the economic results of the transaction. In general, a future is a standardized contract to buy or sell an underlying commodity or instrument (such as grain, oil, or currency) at a future date and at a set price specified on the last trading date. Unlike traditional forward contracts and unregulated derivative contracts that can be traded on an unregulated over-the-counter (OTC) market, a commodity future can be traded only on a regulated futures exchange known as a designated contract market (DCM).
In a commodity market that underlies a DCM, producers of commodities (such as a grain farmer) and users of commodities (such as a cereal manufacturer) enter into contracts to buy or sell a fixed amount of a particular commodity on a cash (or spot) market. The unpredictable nature of underlying commodities markets led to the development of futures markets as a method for producers and users of commodities to spread the economic risk of price fluctuation and other uncertainties. By trading futures on a DCM, producers and users hedge and manage their economic risk by providing an investment opportunity to investors whose money injects liquidity into the market. By engaging in such a hedging transaction, a producer or user can shift or offset economic risk to the investor seeking economic reward. To offset risk in this manner, a hedging producer or user typically takes on a financial obligation that is opposite to his or her obligation in the underlying commercial transaction.
Hedging is not gambling. In a publication entitled The Economic Purpose of Futures Markets , the Commodity Futures Exchange Commission (CFTC), which is the federal agency with regulatory authority over futures and related options trading in the United States, stated that “[m]any people think that futures are just about speculating or ‘gambling.’ While it is true that futures markets can be used for speculating, that is not the primary reason for their existence. Futures markets are actually designed as vehicles for hedging and risk management, that is, to help people avoid ‘gambling’ when they don't want to.”
In contrast to regulated futures markets, participants in gambling activities do not have any underlying commercial relationship. Unlike regulated futures markets, sports gambling activities cannot have any producers with bona fide hedging interests because laws, rules, regulations, league bylaws, and player contracts prohibit teams and their players from buying or selling a commercial interest in their own performance or in the performance of their rivals. Any potential hedging producer (i.e., a team or player) is strictly prohibited from taking a financial obligation that is the opposite of the obligation to perform to the best of his or her ability in the underlying sporting event. Indeed, in the infamous 1919 World Series, eight members of the Chicago White Sox allegedly sold a commercial interest in their future performance against the Cincinnati Reds and then “shorted” their performance during several games of the World Series competition. Thereafter, the Commissioner of Major League Baseball banned the eight players from organized baseball for life. The whole sports gambling industry is based on the outcome of a sporting event or events as determined solely by the performance of the teams or individuals engaged in the sporting event or events. Thus, instruments that pay dividends that are contractually tied to the underlying performance of a team or individual on a field or court (the output of a team or individual) are not futures, even if such instruments are labeled or referred to as derivative contracts.
An option contract (also referred to as an option) is another type of contract that is traded on a regulated exchange. An option, such as that used in a futures market, is a right, but not an obligation, to buy or sell a future or a commodity at a present fixed price called the exercise price (or strike price). The buyer of an option pays a fixed price, called a premium, to the option writer for this right. A call option is the right to buy a future or a commodity at the strike price, and has positive economic value (also known as in-the-money) when the future market price of the future or commodity is greater than the strike price. A put option is the right to sell a future or a commodity at the strike price, and has positive economic value when the future market price of the future or commodity is less than the strike price.
The price of a regulated commodity contract such as a future or option is established when the contract is made in a trade on a regulated DCM. Numerous such exchanges exist throughout the world. Examples of such regulated exchanges in the United States include The Chicago Mercantile Exchange and The New York Mercantile Exchange. In an exchange's traditional form, buyers and sellers engage in trading through intermediaries such as brokers and merchants who use an open outcry system in an exchange pit (also known as a trading floor). Under this traditional system, the exchange acts as both a clearinghouse and regulator of the market.
The ascendancy of electronic (or computer-based) trading has supplemented (and in some cases supplanted) the open outcry system, increased individual direct access to futures markets, and made it easier for traders to enter and exit futures markets directly. Trading on a DCM can be either intermediated or direct (i.e. non-intermediated). A broker or merchant trades on behalf of and for the benefit of the buyer or seller when trading is intermediated. A buyer or seller trades directly on his or her own behalf and for his or her own benefit when trading is direct. The technological advances mentioned above have increased the feasibility of direct trading of commodity contracts, including direct trading of futures and options.
Futures and options trading is the natural outgrowth of maintaining a continuous supply of seasonal products like agricultural crops. Institutional athletic programs also need a continuous supply of a seasonal product such as NLI commitments. In this regard, the present inventors have recognized that collegiate athletic recruiting markets (as well as collegiate education recruiting markets) function in a manner similar to that of traditional commodity markets.
A prospect and an institution that enter into an NLI are natural counterparties to an illiquid transaction. On one hand, a prospect takes a short position and sells his short-term athletic participation for access to the future earning power of a degree. The institution takes the long position and buys the potential that the athlete will contribute to the long-term athletic and economic well-being of the institution. On the other hand, the prospect can be characterized as the party who takes the long position and buys the potential future return on the institution's academic and athletic programs paying off in the form of a degree and long-term economic prosperity. Under such a view, the institution can be characterized as taking the short position and selling one year of grant-in-aid in exchange for one year of athletic participation and resulting revenue.
The characterization of one party's position as short and the other party's as long is not determinative. Rather, as counterparties, a prospect and an institution have a shared bona fide interest in hedging the risk that the price of the NLI commitment will change for the prospect or the institution after the NLI commitment has been executed. For example, a prospect bears the risk that he or she will live in poverty while participating in athletics and the risk that the demands of athletic participation will take precedence over academic development. The institution takes the risk that its spending on its group of prospects will in the aggregate exceed the economic return to the institution, and the risk that the prospect will not attain an academic degree.
Rival supporters of athletic programs also are natural counterparties. For example, the counterparty to an Ohio State football supporter is a Michigan football supporter or a Penn State football supporter. However, unlike the prospect/institution relationship, rival supporters of college athletic programs have no overlapping long-term interest. For example, when Ohio State competes against Michigan or Penn State on the field during a game, the competition between rival supporters of athletic programs is purely a binary, zero-sum (or winner-take-all) proposition.
The competition between rival supporters of competing institutions is a zero-sum competition because a “win” on a football field or other athletic field or court is a purely rival good or interest (rival interest). A purely rival interest has the property that its use by one precludes its use by another. For example, in a football game between Ohio State and Michigan to determine which of the two teams will compete in a Rose Bowl football game, a successful Ohio State performance that results in a win for the Ohio State football team precludes the use of the win by the Michigan football team. As a result, the Ohio State football team goes to the Rose Bowl and the Michigan team does not. Thus, the win resulting from the Ohio State and Michigan competition is a purely rival interest.
In contrast, an institution's athletic program that consists of an aggregate of athletic teams (e.g., football, basketball, volleyball, field hockey, etc.) is a non-rival, partially excludable interest (non-rival interest) because an athletic program as an organizational unit does not actually compete directly on any field or court with any other institution's athletic program. No meta-competition between athletic programs exists. An interest in an institution's athletic program can be used and enjoyed by any person in the public without limiting the use or enjoyment of any other person's interest in the same athletic program. Thus, an institution's athletic program is non-rival.
A non-rival interest has the property that its use by one firm or person in no way limits its use by another firm or person. A purely non-rival interest cannot be traded in a competitive market. However, a non-rival, partially excludable interest can be traded in a competitive market. Generally, an example of a non-rival, partially excludable interest is a design of a membership organization. For instance, beginning in 1971, the New York Stock Exchange (NYSE) was designed as a private, non-profit association. In 2006, the NYSE merged with Archipelago Holdings, a provider of electronic trading technology, and became a public company. As with other public companies, investors now can trade ownership interests (shares) in the NYSE itself.
Another example of a non-rival interest is a design of an institution's athletic program. Thus, while the Michigan football team's loss to Ohio State precludes the Michigan football team from participating in the Rose Bowl, the outcome in no way limits the interest of any person in either Michigan's athletic program or Ohio State's athletic program. Notwithstanding the outcome of the game, all persons in the public remain free to take a tangible commercial interest in either program or both programs by entering into a contract to sponsor the athletic program or by purchasing tickets to athletic events or by making financial donations to the athletic program(s) or their parent institution(s). In addition, notwithstanding the outcome of the game, all persons in the public remain free to take an intangible interest in either program or both programs by simply rooting for teams sponsored by either athletic program in future athletic events. The design of the NCAA is but another example of a design of a non-rival interest, as is the design of the exchange of the present invention.
No non-rival educational athletic program commodity options or futures currently exist. In addition, no exchange currently exists for an institution, a prospect or the public to hedge their long-term risks related to a prospect entering into an NLI (or related contractual) commitment with a particular institution or to determine the price of an institution's non-rival athletic program. Likewise, no exchange currently exists for the non-NLI students at an institution to manage the risk of the rising cost of education during their years at the institution. Accordingly, it is desirable that a device and method of operating the device be established that facilitates trading non-rival, partially excludable educational athletic program commodity options and futures. It is additionally desirable that such a device and method be established to provide institutions with a tool to manage the risks related to the operation of athletic programs and education programs. It is further desirable that such a device and method be established to provide athletic prospects with a tool to manage the risks related to their participation in athletics, including the risk of living in poverty while participating in athletics. It is further desirable that such a device and method be established to provide the public with a hedge against the increasing price of education. It is further desirable that such a device and method be established to provide institutions with a means for growing revenue. It is further desirable that such a device and method be established to inject liquidity into athletics and education. It is further desirable that such a device and method be established to subsidize the growth of the cumulative effect of higher education (human capital). It is further desirable that such a device and method be established to promote economic growth.
BRIEF SUMMARY OF THE INVENTION
The proposed exchange would meet these desires by providing a tool to manage the risks associated with producing collegiate athletic programs and educational programs. In the present context, the term “exchange” or the like refers (either collectively or individually) to the device and method proposed herein, and can be used interchangeably.
In one form, the present invention embodies a futures and options trading exchange platform on which, in exchange for payment of certain premiums, qualified institutions and qualified prospects (the latter also referred to as qualified students) can buy options on an affiliated institution's non-rival athletic program (for example, SYM OHIOSTATE ). Upon exercise of those options, payment of a certain exercise price or strike price, and payment of a transaction fee, those institutions and prospects can sell one or more futures contracts related to that non-rival athletic program. In addition, all other investors participating in trading on the exchange would pay a transaction fee to buy and sell futures on any non-rival athletic program (for example, SYM OHIOSTATE , SYM MICHIGAN , SYM TEXAS , SYM DUKE , SYM NOTREDAME , SYM KENTUCKY , SYM NEBRASKA or the like). Revenues generated from the transaction fee, less the cost to establish and operate the exchange, can be distributed to the general scholarship funds of every institution trading on the exchange. Thus, by subsidizing tuition, the exchange would facilitate a public hedge against the increasing price of higher education. It will be appreciated by those skilled in the art that even though the majority of the discussion herein is within the context of collegiate athletics, it will be understood that the proposed exchange can be extended to manage the risk and cost associated with operating non-rival athletic programs sponsored by other educational institutions such as high schools, prep schools, community colleges, and the like.
Under the proposed exchange, a prospect that signs an NLI (or similar contract) with a particular institution can, for a premium (for example, $100), qualify to buy the right, but not the obligation (a call option), to buy a predetermined number of futures contracts (for example, one thousand) of that institution's non-rival athletic program for a fixed price per future (for example, $1 per future). Likewise, for a premium per prospect (again, for example, $100), that institution can qualify to buy the right, but not the obligation (a call option), to purchase futures contracts for a fixed price (again, for example, $1 per future) for use in its general scholarship fund or at its discretion in a manner consistent with applicable legislation and/or regulation. Identical rights would accrue to all institutions and their prospects that participate in trading on the present exchange.
Once an institution or prospect buys an option to purchase futures, the institution or prospect can exercise the option at the strike price (in the example above, $1) and sell the futures to an investor (for example, a member of the general public who participates in the exchange of the present invention) at the market price. If the option is in-the-money (i.e., the market price exceeds the strike price) at the time the institution or prospect exercises the option and sells the future, the institution or prospect will profit from the transaction.
Similar to the pre-2006 NYSE, the NCAA is a private, non-profit association. The NCAA regulates the eligibility of prospects for participation in collegiate athletics. The NCAA's regulations pertaining to eligibility are not binding on the trading exchange of the present invention. Nevertheless, the options and futures to be traded on the present invention's trading exchange are expressly authorized by NCAA regulations, and are consistent with the spirit of the regulations. The NCAA only prohibits a prospect from receiving pay or gifts or “extra benefits.” The NCAA does not prohibit a prospect from buying regulated financial products or making any sort of investment that is subject to risk, such as an investment opportunity involving the options and futures created by the present invention. On the present invention's trading exchange, prospects will not receive pay or gifts. Indeed, the present invention's trading exchange incorporates the exact opposite relationship, as prospects must pay a premium for such options, an exercise or strike price for futures contracts, and the same transaction fees that all investors must pay.
NCAA Bylaw 16.02.03 expressly provides that “[r]eceipt of a benefit by student-athletes [a/k/a prospects] or their relatives or friends is not a violation of NCAA legislation if it is demonstrated that the same benefit is generally available to the institution's students or their relatives or friends or to a particular segment of the student body (e.g., foreign students, minority students) determined on a basis unrelated to athletics ability.”
On the trading exchange of the present invention, the benefit of these options and futures (if any) will be available to both prospects and other students (through the university as intermediary) on a basis other than athletic ability. The benefit (if any) to prospects and other students is uniform in that it is a hedge against the respective economic risks borne by athletic prospects and by other non-athlete students. Prospects bear the short-term risk that they will live in poverty while participating in collegiate athletics, but do not bear the risk that the price of their education will increase as the institution absorbs that cost. In contrast, other non-athlete students are not prohibited from accepting pay and benefits by NCAA rules or time commitments to collegiate athletics. However, such students bear the short-term risk that the price of education will increase. In other words, the short-term risk borne by athletic prospects is the inverse of the short-term risk borne by non-athlete students. Moreover, both prospects and other non-athlete students share the long-term risk that their respective short-term risks will interfere with their shared long-term interest in obtaining an academic degree. While the long-term risks borne by prospects and other students are directly related and their short-term risks are inversely related, the trading exchange of the present invention provides “the same benefit” to both prospects and other non-athlete students in the form of a hedge against their economic risks.
In addition, by generally subsidizing tuition on a basis unrelated to athletic ability, the trading exchange of the present invention provides a subsidy of the production of human capital on a basis unrelated to athletic ability. Human capital is a distinct measure of the cumulative effect of activities such as formal education. In other words, human capital is a distinct measure of the accumulation of knowledge derived from higher education. According to economist Paul Romer's model in a paper entitled Endogenous Technological Change , “knowledge enters into production in two distinct ways. A new design enables the production of a new good that can be used to produce output. A new design also increases the total stock of knowledge and thereby increases the productivity of human capital in the research sector. The owner of a design has property rights over its use in the production of a new producer durable but not over its use in research. If an inventor has a patent design for widgets, no one can make or sell widgets without the agreement of the inventor. On the other hand, other inventors are free to spend time studying the patent application for the widget and learn knowledge that helps in the design of a wodget. The inventor of the widget has no ability to stop the inventor of a wodget from learning from the design of a widget. This means that the benefits from the first productive role for a design are completely excludable, whereas the benefits from the second are completely non-excludable. In an overall sense, this means that the nonrival design inputs are partially excludable.”
Romer's model suggests that what is important for economic growth is “integration not into an economy with a large number of people but rather into one with a large amount of human capital.” Subsidizing the general accumulation of knowledge (human capital) by generally subsidizing the tuition of non-athlete students in order to produce economic growth is one of the economic purposes of the present invention.
The trading exchange of the present invention provides a subsidy of tuition expenses of non-athlete students and the accumulation of knowledge (human capital) that is independent of the performance or outcome of any athletic event or events to every institution whose non-rival athletic program is traded on the exchange by providing a percentage of a transaction fee charged for each trade made on the exchange to each institution. Thus, the trading exchange of the present invention is calculated to produce economic growth as measured by the accumulation of knowledge (human capital) that is independent of the outcome of any athletic event or events, which clearly is a basis unrelated to athletic ability.
The institution alone will select those prospects with whom it will enter into NLI commitments and who thereby might benefit from buying options and selling futures. The institution alone, acting as an intermediary, will select those other students who might benefit from that institution's intermediated buying of options and selling of futures. The benefits, if any, that prospects and other students will receive from trading on the present invention's exchange will be determined by trading skill and market forces, which clearly is a basis unrelated to athletic ability. In addition, increased contributions to an institution's general scholarship fund made possible from trading and operation of the exchange of the present invention will benefit all students attending that institution, which is also a basis unrelated to athletic ability.
On the present invention's trading exchange, the options are similar in nature to tuition as well as athletic scholarships and academic scholarships that institutions have provided to athletic prospects and scholars since the 1950s. Like tuition or a scholarship, the option is an investment in prospects, other students and the institution that carries both potential risk and potential reward to the same. The option is leverage that prospects and the institution mutually and symbiotically employ in pursuit of a better future for all students, as opposed to an immediate benefit for one group at the expense of another group.
There is precedent in higher education for using market designs, methods, and tools for educational purposes. For example, the University of Iowa Tippie College of Business has operated the Iowa Electronic Markets as part of its “research and teaching mission.” The Iowa Electronic Markets are a group of real-money futures markets that allow traders to buy and sell contracts based on political election results.
In addition, in January of 1956, Nobel Prize-winning economist Vernon L. Smith created a student market in his classroom in which student-traders engaged in trading with one another within the classroom. Smith found that the classroom market maximized the group's total gain from trading. In other words, the classmates could not have done any better had someone with perfect knowledge told them what to do. According to James Surowiecki's book The Wisdom of Crowds , “in the four decades since Smith performed that first experiment and published the results, they have been replicated hundreds, if not thousands, of times, in ever more complex variations. But the essential conclusion of those early tests—that, under the right conditions, imperfect humans can produce near-perfect results—has not been challenged.”
Section 2(a)(1) of the Commodities Exchange Act (the Act) defines a “commodity” to include all “goods and articles . . . and all services, rights and interests in which contracts for future delivery are presently or in the future dealt in . . . ” According to a former chairman of the CFTC and the author of the treatise Commodities Regulation , under this section of the Act: “Congress expanded the definition of commodity to encompass virtually anything that is or becomes the subject of futures trading, intangible as well as tangible . . . . A fair reading of the amended and expanded definition suggests that, as for ‘all goods and articles . . . and all services, rights and interests,’ their status as statutory commodities does not emerge until they become the subject of futures trading. Although this method of converting something into a commodity may seem curious, it illustrates an important principle of commodities regulation: Its interest is in a form of economic activity rather than in the attributes or character of the underlying subject. The economic activity in question is futures and commodity options trading; the nature of the commodity does not affect the regulatory result.”
The subject assets underlying the options and futures traded on the exchange can be thought of as a basket (i.e., aggregate) of NLI commitments that each institution's non-rival athletic program accumulates through the recruiting process. Unlike the trading of some traditional commodity futures such as wheat or oil, the cash value of a basket of NLI commitments is unknown and currently is not measured by any external economic index or reference point. Nevertheless, a commodity does not require a cash market in order for the commodity to be traded as a future. As observed in Commodities Regulation : “[M]ost futures and commodity option contract prices, unlike securities, are normally related to prices actively and continually made in a separate commercial market, and this interrelationship imposes a form of price discipline on futures contracts. The latter, in other words, will seldom deviate substantially from prices being actually paid for the same commodity in the commercial world. The reasonableness of most futures prices, therefore, can be tested against an external reference point. No such opportunity is presented to the securities investor, who can look only to the securities market itself for price information. Techniques have been devised, of course, such as the test of price-earnings ratio, to analyze the attractiveness of a particular security's current price, but these formulas are fraught with subjective evaluation and are frequently ignored . . . . Financial futures and options reflect the underlying value of government obligations, foreign currencies, and stock indexes, all of which can be said to lack the firmer external reference points applicable to other commodities.” Weather options and futures are contracts traded on regulated DCMs where the underlying commodity (weather) is not benchmarked in monetary units or subject to a cash market.
Institutions face cyclical periods of interest in their non-rival athletic programs. For example, college football operates pursuant to a business cycle composed of four quarters or seasons. A first season is made up of pre-season preparation and non-conference competition, a second season is made up of conference competition and bowl games, a third season is made up of recruiting competition and spring practice, while a fourth season is the quiet period between seasons three and one. By way of example, NCAA Division I-A institutions face a cyclical period of relatively low interest in their football programs during the fourth quarter discussed above, which runs from the end of the recruiting season and spring practice until the majority of new prospects begin arriving on campus in the later summer and early fall. As with weather futures, the present invention will enable institutions and prospects to make available a large base of written options that will provide liquidity for a seasonal futures market in NLI commitments.
The basket of NLI commitments known as recruiting classes that make up a non-rival athletic program are the assets underlying the present invention's trading exchange, and as mentioned above with weather futures, are not measured in monetary units. Nevertheless, an investor who uses the exchange of the present invention to invest in a particular institution's non-rival athletic program will have at least four external reference points or benchmarks by which he or she can judge an investment: (1) an institution's and a prospect's option exercise price per future (for example, $1); (2) a market price or prices at which futures related to competing institutions are trading; (3) an NCAA-set settlement bid floor price of $0; and (4) an exchange-set maximum ask ceiling price and settlement ask price (for example, $100). In situations involving a companion market, an additional benchmark, that of a composite or aggregate index of some or all of the institutions, may be used.
In one embodiment of the present invention, the value of a non-rival athletic program's future is the absolute future value between $0 and $100 of the non-rival athletic program to a person with a tangible interest (i.e., commercial or contractual interest) or intangible interest in the program. The future value of the non-rival athletic program is nothing to a person who values the program at $0 and everything to a person who values the program at $100 and something in between for values $0 to $100.
In a typical futures market, an investor that buys or sells a commodity future such as oil knows the absolute spot price of the oil on the day he or she purchases the future, while the future settlement price is liquid and fluctuates relative to the spot price. The present invention embodies the inverse scenario. An investor that buys a future in a non-rival athletic program would know that, consistent with NCAA rules, the absolute future settlement price of the future on the primary market would be $0, but the spot price of the non-rival athletic program would be liquid and fluctuate relative to the price of the futures of the non-rival athletic programs of all other competing institutions traded on the exchange. Likewise, an investor that sells short a future in a non-rival athletic program by depositing $100 with the exchange and borrowing a future would know that, consistent with exchange rules, the absolute future settlement price would be $100, but the spot price of the non-rival athletic program would be liquid and fluctuate relative to the price of the futures of the non-rival athletic programs of all other competing institutions traded on the exchange. In other words, an investor will not be speculating where a future will settle at the end of trading. Rather, an investor will be speculating as to what traders will be willing to invest in NLI commitments at every instant in time prior to settlement. As Nobel-prize winning economist Kenneth Arrow stated in The Theory of Risk - Bearing: Small and Great Risks , “[w]hat the markets for risk-bearing achieve is an efficient distribution of the risks as viewed before the event. In this respect, it is like the workings of the price system in general. If a commodity, e.g., oil becomes less available, the economy is going to be worse off. What the price system does is to make the loss to society as small as possible.” The present inventors expect that what one aspect of the trading exchange of the present invention will achieve is an efficient distribution of the risks of producing non-rival athletic programs. In this respect, the trading exchange of the present invention works like a price system for the purpose of insuring and sustaining the unique collegiate model of athletics. Insuring and sustaining the unique collegiate model of athletics is one of the economic purposes of the present invention.
The discussion above describes the operation of a risk-neutral exchange with a single primary market. In a variation, investors also will be able to speculate and hedge the risk of buying and selling futures in the primary market by trading in a companion market that aggregates and indexes the price of all futures traded on the exchange. At all times, the public trading of all futures will yield an aggregate mean price per future. In the companion market, an investor can buy an index future contract (index future) if he or she expects the aggregate mean price to increase. Correspondingly, an investor can sell index futures if he or she expects the aggregate mean price to decrease. Thus, investors in index futures will speculate on where the aggregate mean price per future will finally settle, and can use index futures to hedge underlying future trading in the same way that the trader of traditional commodities can hedge his or her position by trading commodity index futures, such as Goldman Sachs Commodity Index Futures (GSCI Futures).
In one embodiment of the present invention, the final settlement price of the index futures will be the special quotation of the aggregate mean price per future on a pre-determined, final day of the trading period. Investors holding open positions in index futures at the time of the expiration of trading will realize a gain or suffer a loss based on the final settlement price and will receive a payout based on a pari-mutuel risk-sharing rule or some other risk-sharing rule.
In another embodiment of the present invention's companion market, the market price of any index future traded on the system, and therefore the risk assumed by every investor in index futures, would be strictly bounded between two fixed endpoints. At expiration, the payoff will be based on the ending aggregate mean price per future, relative to the index future range. If the aggregate mean price per future ends at or below the floor, the payoff is $0 for the buyer and the stated contract size for the seller. If the aggregate mean price per future ends at or above the cap, the payoff is the stated contract size for the buyer and $0 for the seller.
If the aggregate mean price per future ends between the floor and the cap, the stated contract size is split between the buyer and seller, where the buyer receives $A for every B tick the aggregate mean price per future finished above the floor and the seller receives $X for every Y tick the aggregate mean price per future finished below the cap, such that payoff for the buyer increases when the aggregate mean price per future ends closer to the cap, and payoff for the seller increases when the aggregate mean price per future ends closer to the floor. In addition, investors could close their positions prior to expiration by selling their index futures at any time before the last trading date. In such cases, the profit or loss is the difference between the price received and the price paid. It will be appreciated by those skilled in the art that other variations of futures and options contracts based on the index can be traded on the companion market.
The exchange will not permit qualified prospects or qualified institutions to take, own or otherwise control a short position on any contract traded on the exchange. Qualified institutions and qualified prospects will be strictly limited to taking, owning or controlling long positions. By limiting the qualified institutions and the qualified prospects to taking, owning or controlling long positions in their particular non-rival athletic program, the exchange of the present invention will eliminate the incentive of any qualified institution or qualified prospect to use less than best effort when participating in such non-rival athletic program.
The exchange will not permit margin accounts. Thus, for an investor to take a long position (i.e., buy futures) or a short position (i.e., sell futures) on a given number of futures contracts, he or she will have to post in an account a deposit adequate to cover the difference between the bid/ask price and the settlement price. For buyers of futures, the deposit will be equal to the bid price. For non-institution and non-prospect sellers of futures (i.e., supporters and investors), the deposit will be $100 per future. For an institution or a prospect, no deposit will be necessary as long as a bidder with an unfilled order greater than the exercise or strike price (for example, $1 per future) exists to take the institution's or prospect's sale price offer. If no such bidder exists and an institution or a prospect still desires to exercise options, the institution or prospect will have to make the appropriate deposit.
Consistent with well-established principles of commodity markets, the exchange will employ reasonable open interest limits and position limits to prevent any person or entity from cornering, squeezing, or otherwise manipulating a non-rival athletic program. For example, limits that restrict an investor to a total of one thousand open interests and/or positions at any one time essentially would limit an investor to bidding for one prospect at a time. Such pro-competitive limits will increase liquidity within the market.
In accordance with a first aspect of the present invention, a method of electronically trading futures contracts associated with non-rival athletic programs of one or more educational institutions is disclosed. The method includes granting an option to one or both of a qualified student and a qualified educational institution that sponsors a non-rival athletic program that the student participates in, configuring an exchange to execute trading of one or more futures contracts, and facilitating at least one trade on the exchange between a seller of one or more futures contracts and a buyer of one or more futures contracts. In the present context, a student and his or her corresponding educational institution may become qualified by entering into an underlying contractual commitment, such as the aforementioned NLI or the like. Also in the present context, futures contracts tradable on the exchange may include both those that are initially bought by the qualified student, educational institution or both, as well as those initially or subsequently procured by investors.
Optionally, the method includes storing trade information data corresponding to each of the trades. Such data may be aggregated to provide information relating to market liquidity, trading or transaction revenues and other such data as the exchange operators, regulators and others may find useful. Configuring the exchange may include electronically connecting a host computer to a remote client computer through a network. In this way, a trading algorithm that can be installed in or otherwise cooperative with one or more of the host computer, network and remote client computer performs the one or more arranged trades. This may also include functionality beyond the mere executing of trades, such as keeping records of the trades made. In this way, the trading algorithm (or another algorithm cooperative with the trading algorithm) may be programmed to establish user accounts. In this way, automated record-keeping may be implemented. This can be a valuable way to show each user's transactions, as well as a way to credit or debit the user's account. In one preferred embodiment, the exchange operates as a DCM that complies with operating requirements of the Commodity Exchange Act.
According to another aspect of the present invention, a method of managing economic risk associated with producing educational non-rival athletic programs is disclosed. The method includes qualifying one or more educational institutions and one or more prospects within that institution's non-rival athletic program. Once qualified, the prospect, educational institution or both may purchase (for a fixed premium price) an option to purchase (at a fixed strike price) one or more futures contracts in the institution's non-rival athletic program. The method further includes granting the option to the qualified institution, student or both so that they may purchase futures contracts once the option has been exercised. The method also includes facilitating the exercise of the option. For example, in a configuration where the method is at least partially achieved over an electronic exchange, such facilitating may be in the form of the exchange (including trading software) allowing the qualified student or representative of the qualified educational institution to proceed with paying an option premium, after which the qualified student or representative of the qualified educational institution may be able to purchase one or more of the futures contracts through an account held on the exchange by the qualified student or representative of the qualified educational institution. The method additionally includes matching a bid to purchase and an offer to sell one or more futures contract. The method also includes collecting data associated with each matched trade. Such data may include price data, volume data as well as other data. Furthermore, final settlement prices are established for the futures contracts, as well as bids to purchase and offers to sell the futures contracts that are neither matched nor cancelled by the predetermined date.
Optionally, the qualified educational institution and student achieve their qualified status by entering into an underlying binding agreement that obligates the institution to provide the student with the opportunity to attend the institution (such that the student may participate in academic and athletic program offerings of the institution) in return for the student to provide his or her participation in the non-rival athletic program. Typically, the institution satisfies its part of the agreement by providing grant-in-aid or other form of tuition reimbursement, as well as reimbursement of the cost of other necessities. As discussed above in conjunction with the previous aspect, the underlying agreement may be in the form of an NLI or other written instrument. In a particular form, the method may further include prohibiting the student and the institution from selling or trading contracts and options associated with any other educational institution's non-rival athletic program. In another form, the method may be used to prohibit any student and his or her respective institution from opening, owning or controlling a short position in the market in the form of one or more open futures contracts in that educational institution's non-rival athletic program.
In a preferred form, the method operates as a DCM. More particularly, buying and selling of one or more futures contracts on the DCM can be either direct or through an intermediary. In another option, the maximum total number of open interests and positions that may be held or controlled by a single trading entity cannot exceed the number of futures that a qualified student or qualified institution have the right to purchase. For example, if the maximum number of futures contracts that a qualified student or his or her respective educational institution has the right to purchase is one thousand, then an investor may control no more than a total of one thousand open interests and positions at any one time. In the present context, an investor is either an individual (such as those that are registered with the exchange), an intermediary of an individual or pool of individuals. The method may further include facilitating trading a composite index. In such form, such an index (with the corresponding contract referred to as an index futures contract) represents an unleveraged, long-only investment in futures contracts of one or more of the qualified (i.e., participating) educational institution's non-rival athletic programs that are traded on the designated contract market. The composite index serves as a benchmark of the value of the educational institution's non-rival athletic program, or as a benchmark of the value of the aggregate value of all non-rival athletic programs traded on the exchange. In this way, the composite index serves as a measure of the educational institution's non-rival athletic program, or as a measure of the aggregate value of all non-rival athletic programs traded on the exchange over time.
A future final settlement value of a futures contract to purchase an interest in the institution's non-rival athletic program can be fixed at zero dollars, while a future final settlement value of a futures contract to sell an interest in the institution's athletic program is fixed at a value greater than zero dollars. In one example, the future value of the futures contract is between a floor value of zero dollars per futures contract and a ceiling value of one hundred dollars per futures contract.
According to another aspect of the present invention, a method of hedging the risk of future education costs is disclosed. The method includes granting options to purchase futures contracts to at least one qualified educational institution that sponsors a non-rival athletic program and one or more qualified prospects within that educational institution's non-rival athletic program. In addition, the method includes configuring an electronic DCM to execute trading of one or more of the futures contracts, facilitating trading on the electronic DCM between a seller of at least one of the futures contracts and a buyer of at least one of the futures contracts. Such a transaction generates a transaction fee for the operator of the exchange, and the operator may distribute at least a portion of the transaction fee revenue to a scholarship fund or other fund to further the educational institution's academic mission. Optionally, the method can be used to subsidize at least a portion of tuition expense of one students in the student body of the qualified educational institution. Such subsiding may come from a portion of the revenues generated by the transaction fees.
In accordance with another aspect of the present invention, a device for trading derivative contracts of one or more educational institutions is described. The device includes a data input, a data output, a communications link and a computer readable medium onto which trading software or a related algorithm can be placed or operated. The data input receives trading instructions or requests for trading information from the trader, while the data output can convey (for example, visually through a display screen or hard copy printout, or aurally through a speaker) either the input trading instructions or request for trading information that may be of interest to the trader. Such trading information may include, among other things, a list of participating educational institutions, current bid or ask prices, quantity available, open contracts, recently-completed contracts, or news or other information pertaining to one or more contracts that are available for trade, as well as the educational institutions to which those contracts correspond. The communications link allows electronic connection between one or more of the data input and data output to a trading exchange, while the computer readable medium is cooperative with them such that the trading software or related algorithm loaded on the medium can instruct one or more parts of the device to perform a trade.
Thus, when the trader places an offer to sell or a bid to buy the contract through the data input, an algorithm on the computer readable medium processes data associated with the bid or offer and compares it against currently available contracts and their price, quantity or other trading parameter in order to establish a trade between the trader and another trader who makes a complementary offer or bid on the contract. In the present context, a complementary bid or offer is one that, upon satisfaction of one or more trading criteria, can be paired with an opposing offer or bid such that ownership of the contract is conveyed from the seller to the buyer in exchange for money, another contract, or item of comparable value. As an example, bids and offers can be matched based on price, quantity or like criteria. Likewise, other factors, such as counterparty credit limit, trade clearing, trade settling or other appropriate indicia may form the criteria necessary to effect matching complementary trade positions. Furthermore, terms such as “bid”, “offer” and “ask” are used in the present disclosure in both particular and colloquial forms. For example, the term “offer” may be understood colloquially to represent a general buy or sell request, with no loss of specificity to a particular side taken by a trader in an underlying trade.
In one particular form, the contracts are based on mutually agreed-upon obligations (for example, contractual commitments such as an NLI) between one or more prospects and the educational institution. While the NLI is the most common contractual vehicle for binding an institution and a prospect, the present inventors believe that other such vehicles, either presently known or developed in the future, may be used to ensure an underlying commercial relationship. Thus, any contract that mimics the attributes of an NLI contract would suffice to form the underlying relationship. The proposed exchange would provide a trading platform on which qualified institutions and qualified prospects could purchase and exercise options and sell futures on their specific non-rival athletic program, while the general public could buy and sell futures on any participating institution's non-rival athletic program. The present inventors believe that using the NLI as the underlying commodity or instrument is sufficient to sustain significant market activity, as recruiting and signing prospects is already embedded in the public consciousness.
The device is preferably in the form of a computer-implemented trading system that involves a network, including one or more host computers and one or more client computers linked to the host. Such a system allows buy and sell orders initiated at the client devices to be matched up by the host machine. There are numerous optional configurations for the computer readable medium, including hard disk drive, compact disk (CD), digital video disk (DVD), floppy disk, flash memory and propagated signal transmitted over the communications link. The computer readable medium can be resident with one or more of the data input, data output and trading exchange. In the present context, the term “resident” means that physically the medium is situated in, on or cooperative with the respective device in such a way that together they function as a unitary whole. This may include having the medium adjacent the other components of the computer. For example, if the medium is resident on a laptop computer, it is either enclosed inside or readily attachable to the frame or case of the laptop, or may be signally connected thereto. Likewise, if the medium is resident on a desktop computer, it can be enclosed within or signally connected to the case, input, output or memory. One or more of the data input and data output can be configured as a graphical user interface, thereby facilitating ease of use. In another form, the data input and data output include a client terminal configured to send, receive and view data related to one or more of a placed order, a completed trade or trading information.
In another option, the trading information is arranged in a database that includes identification of one or more educational institution's athletic programs that are available for trading through the device. Other database information may include current trading price and current number of the contract that corresponds to the identified program that are available for trading. Furthermore, the database may also include more detailed contractual obligation information, such as identification of the number of prospects who are contractually obligated to the identified program. The database may also be configured to include identifying information about such prospects. The same could apply to authorized trading intermediaries or pools of the participating institutions. The present inventors envision this as a way to enhance security, as an individual purporting to be a prospect or intermediary or pool could be cross-checked against the database to ensure that the prospect or intermediary or pool in fact has entered into a qualifying underlying commercial relationship.
According to yet another aspect of the invention, a device for trading futures relating to a non-rival college athletic program is disclosed. The device includes a central trading platform, a database made up of a collection of available non-rival athletic programs from which a trader may choose to trade, means for exchanging order information (such as trader input) pertaining to the futures contracts of the non-rival college athletic program, means for executing a trade of futures relating to the non-rival college athletic program and means for informing traders of a contract fill status. Each of the athletic programs within the database includes identification that distinguishes one program and its related futures contracts from another.
Optionally, the central trading platform is an electronic trading platform made up of one or more processing units, one or more memory storage devices to exchange data with the processing unit or units, and related computational componentry. The various means for exchanging, executing and informing may be a computer program that is cooperative with the platform. Thus, the means may be embodied in computer software, firmware or hardware, and includes algorithms that, in conjunction with the aforementioned computational componentry, can perform the desired function. The input interface can receive data associated with futures contracts relating to one or more non-rival college athletic programs selected from the database. As stated above in conjunction with the previous aspects, the derivative nature of the contract (for example, a futures contract) has as an underlying asset a contractual commitment between a prospect and a particular educational institution. In a preferred form the contractual commitment is an NLI between an athletic prospect and the particular college or related educational institution. The computer program module provides instruction to the processing unit so that trader buy and sell orders selected from the database can be matched. The computer program module is further operative to enable not just the trading transaction, but also contract listing, availability, price, quantity or the like. The device may further include the ability to settle a trade and clear the trade. In another option, the device need not be an automated, computer-based system, where some of the features can be used in a manner generally similar to the open-outcry method, where certain functions, such as means for exchanging contract order information, means for executing a trade and a means for informing traders could be performed using human intermediaries equipped with mechanical or electrical members (including paper-based hard copies) to convey and record contract order information. The device may further be configured as an exchange, such that it may be particularly tailored to the trading of futures relating to one or more non-rival college athletic programs. In a particularly desirable form, the exchange can operate as a designated contract market.
According to still another aspect of the invention, an article of manufacture comprising a computer usable medium having computer readable program code embodied therein for executing a trade of one or more futures contracts relating to one or more college athletic programs. In the article, the computer readable program code includes means for causing a computer to accept at least one bid from a buyer, means for causing the computer to accept at least one offer from a seller, means for causing the computer to match the bid and the offer, thereby effecting the trade, and means for causing the computer to notify the buyer and the seller that the trade has been executed. These means may be in the form of program code segments, portions, routines, subroutines or the like to ensure proper execution of the command contained in those means. The program, when installed in an appropriate computer, enables the computer to trade athletic futures contracts (such as the non-rival futures contracts discussed in conjunction with the previous method aspects) on an electronic exchange. The program code recorded on the medium can perform numerous functions, including (but not limited to) listing available futures contracts, accepting trader input, keeping track of the trader's account, displaying information pertaining to currently available trade orders, completing a trade and reporting the results of the trade to the trader. The computer readable program code may include, or have access to, one or more databases that contain contractual obligations between a college and an athletic prospect. In this way, such database and program code can help ensure that a particular college and athletic prospect can participate in trading college athletic futures contracts.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The following detailed description of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
FIG. 1 shows a block diagram of a trading system according to an embodiment of the present invention;
FIG. 2 shows a flowchart with a sequence of steps that may be executed in conjunction with the system of FIG. 1 in order to trade novel options and futures contracts.
FIG. 3A shows a welcome screen for an exchange corresponding to an embodiment of the present invention;
FIG. 3B shows a log-in screen for entrance into an individual trader account;
FIG. 3C shows the home screen of a registered trader that successfully logged-in from the screen of FIG. 3B ;
FIG. 3D shows a screen highlighting trading choices of educational institutions that participate in futures trading on the exchange of FIG. 1 ;
FIG. 3E shows a screen highlighting a particular educational institution chosen in FIG. 3D ;
FIG. 3F shows an active trading screen with available trading choices that appears when a trader hits the trade icon of FIG. 3E ;
FIG. 3G shows fields where a trader can input a desired quantity of futures contracts, as well as a price per contract;
FIG. 3H shows a verification of trade quantities and prices initiated by the trader in FIG. 3G ;
FIG. 3I shows a confirmation of receipt of an order placed by the trader in FIG. 3H , including additional trading options;
FIG. 3J shows when a contract order placed by the trader in FIG. 3I has been accepted and completed, as well as giving the trader the option of making additional trades;
FIG. 3K shows a screen that displays the most traded educational institution futures contracts that a user can access by clicking on the “top 25 most active programs” icon of FIG. 3A ; and
FIG. 3L shows a screen generally similar to that of FIG. 3C , except now tailored for use by a trader who is also a qualified prospect or a trader who represents a qualified educational institution.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1 , a computerized system 10 is employed to provide the electronic infrastructure for an automated embodiment of the device of the present invention. A host computer 1 is linked by a network 15 to numerous remote client devices 20 such that together they take advantage of the network's broad-based communications capability for having one or more remote machines communicate with and transfer information and related data to and from the host computer 1 , server, mainframe, minicomputer or related central machine. In one form, the network 15 can be a direct, dedicated connection between the host computer 1 and one or more remote client devices 20 . Preferably, the dedicated connection provides high-bandwidth, such as can be found in T1 lines, Ethernet lines or local networks. In another form, the network 15 can be the internet generally and the World Wide Web, or more concisely, the web, specifically. In either configuration, such a distributed approach allows any number of traders to simultaneously connect to the host computer 1 to enable real-time trading. It also enables the traders to exercise control from a location convenient to the trader, regardless of the physical situs of the host computer 1 , communication link (such as network 15 ) or other components of system 10 . In such a way, a user can control the transmission of information originated at remote client device 20 and benefit from the exchange of information with host computer 1 as long as communication between the remote client device 20 and host computer 1 is available. In one form, either or both of the host computer 1 and the remote client device 20 may be general purpose digital computers that can be suitably programmed to accomplish the trades and listing of available trades discussed herein. In the present disclosure, remote client device 20 may also be referred to as a remote client computer, or more simply a computer; the degree of specificity will be apparent from the context.
All traders who are connected to the host computer 1 have equal access to order routing (for example, order entry, modification, cancellation, confirmation, fill and related management), market data and other information relating to trading the futures contracts discussed herein. The real-time availability of market data and related information gives each trader the ability to quickly ascertain market movements. Relevant information can include, but is not limited to, the current trading price of the contracts then offered, as well as volume of trades relating to a particular non-rival athletic program within a particular institution. Connectivity to provide such order routing and market data can be achieved through interfaces between the trading customer and the host computer 1 . Such interfaces can use either proprietary or well-known industry standard protocols, such as the Financial Information eXchange (FIX) protocol, or an Application Programming Interface (API).
The host computer 1 can be set up to conduct the same administrative functions normally performed by a conventional floor-trading exchange, including taking trade orders, matching competing trades, providing current trading information to all participating traders, ensuring the security and integrity of the trades as well as maintaining a proper accounting of positions and to what accounts corresponding debits and credits should be placed in to ensure prompt and accurate clearing and settlement of all trading contracts in the system 10 . One attribute of the system 10 is that by its automated operation, it does not interfere with the natural operation of the market. Thus, outside of a minimum and maximum contract value, it is solely the marketplace made up of the connected traders that determines price movements of the contracts being traded, not the system 10 or its operator. What control the operator does have is preferably limited to the aforementioned security, administration and trading protocols, all of which can be implemented through trading software (also known as a trading application). Likewise, trading and accounts can be set up so that the traders may maintain their anonymity, or be known to other traders.
Preferably, system 10 includes redundancy to ensure uninterrupted operation. Examples include distributed processing and computation capability, redundant software implementation, database rollback schemes (a statement in SQL where proposed changes in a pending database transaction are cancelled) and other methods known to those skilled in the art. In addition, the system 10 is scalable, including high throughput (i.e., bandwidth) communications links and additional processors to handle increases in trading load. The system 10 also includes security and data integrity features that control access to the system 10 , as well as perform authentication and verification of trading transactions. It will be appreciated that existing conventional authentication methods could be used to promote accurate, secure operation. Such security measures also can be used to monitor fund activity (for example, deposits and withdrawals) within traders' accounts. Furthermore, built-in third party operations and automated systems can be employed, including those for verification, authentication and fulfillment of credit card and related transactions. Encryption protocols and software, for example, secure shell (SSH), secure sockets layer (SSL) and transport layer security (TLS) can be used in conjunction with a multiplicity of trader verification steps by the host computer 1 to promote security for the trade orders between the host computer 1 and the remote client device 20 of the subscribing trader. As will be described in more detail below, additional security is ensured through the use of unique trader identifiers known only to the system 10 and the individual trader.
Those skilled in the art will appreciate that alternative hardware environments may be used without departing from the scope of the present invention, and as such, the precise configuration of the system 10 presently depicted in FIG. 1 is not intended to limit the present invention. As will be further understood by those skilled in the art, the term “network” may encompass various forms of connectivity between two or more machines, including point-to-point, shared, dedicated, intermittent or the like. The terms “network”, “web” and “internet” are understood by those skilled in the art as being possessive of particular attributes that distinguish each from the other. For example, the web is more precisely thought of as a subset of internet sites. Nevertheless, each of these terms may be used interchangeably in the present context to convey the necessary host and client connectivity unless specifically noted.
The web is a hypertext-based system. In that way, it can use its hypertext protocols and language on network 15 to facilitate communication between a server (e.g., the host computer 1 ) and a client (such as the remote client device 20 ). Hypertext markup language (HTML) is the language used by web servers to create and connect documents that contain network addresses called hyperlinks, which allow a user to navigate through a web site. For example, HTML functions as a mark-up language that breaks the document into syntactic portions that specify layout and contents. As will additionally be understood by those skilled in the art, the web and other network connections may be through either a wired or wireless configuration, the latter in the form of radio-frequency (RF) or related waves across the electromagnetic spectrum. One particular form of wireless connectivity can be in the form of a satellite-based system 70 that can relay data worldwide, employing laser or related optical or electronic carriers. Particular forms of wired communication configurations include conventional telephone lines, as well as co-axial cable, fiber-optic bundles or the like. A market data feed 80 can be used to provide up-to-date information related to the market, various institutions and their athletic or educational programs, or other information (such as streaming quote information) that may be of interest to a trader. Market data feed 80 can be provided to host computer 1 by satellite 70 , the internet or any other communication link known to those skilled in the art. Moreover, market data can be disseminated by the host computer 1 to remote users through various channels, including the operator of the host computer 1 , trading software 45 C, third-party trading application programs, quote vendors or the like. Such information updates are compatible with either electronic trading or open-outcry trading configurations.
Connection between the remote client devices 20 and the host computer 1 within the network 15 may be made using any suitable network interconnection rules, a commonly-used example of which is the TCP/IP protocol for transmitting packets of data over a wide or local area network, where the latter may be a node within the former. TCP/IP is a popular internet protocol because it provides file transfer, electronic mail and remote log-in capability for large numbers of host and client systems. TCP is often used in conjunction with a file transfer protocol (FTP) to transfer files between computers linked together by the internet. Arbitration between computers can take place through various systems known to those skilled in the art, such as a Token Ring or Ethernet. TCP/IP is configured to run on top of these protocols.
The remote client devices 20 may be in the form of a computer, personal digital assistant, telephone (including cellular phones), touch screen, pager or other device suitably-configured to communicate with the host computer 1 . When the remote client device 20 is in the form of a computer, it may include a microprocessor 25 , a memory storage device (also referred to simply as memory) 30 (including volatile random access memory (RAM) and nonvolatile read-only memory (ROM)), an input 35 (such as a mouse, keyboard or voice recognition system), an output 40 (such as a monitor or related display), as well as software (also referred to as programs or applications) 45 to facilitate cooperation between the various computer components, as well as between different devices within the system 10 . Throughout the remainder of this disclosure, references to computer 20 are meant to cover the particular embodiment of remote client device 20 , yet will be considered to encompass the other forms of remote devices shown in FIG. 1 . Thus, any electronic device that accepts structured input, processes it according to prescribed rules and produces the results of that processed input as output would qualify as a computer in the present disclosure. Such interpretation is consistent with the von Neumann architecture of a computer, which includes an input, output, memory, arithmetic logic unit (for example, the aforementioned microprocessor) and a central control unit to orchestrate operations. In this context, the personal digital assistant, telephone, pager or related devices discussed above could be configured to operate as a rudimentary computer, and as such would be within the scope of that term's present definition. The computer 20 may also include communication hardware 50 for supporting the transfer of data between it and the host computer 1 .
Software 45 comes in various forms, including operating system software 45 A and application-specific software 45 B. An example of the former (such as Microsoft Windows) is that which allows the latter to make use of the input 35 , output 40 and other hardware components within the computer 20 . Application specific software 45 B can run on top of the operating system software 45 A, performing functions based on user input. Examples of application specific software 45 B include word processing and trading-specific software 45 C, the latter of which is of particular interest in the present context. Application specific software 45 B used for receiving and transmitting data can be loaded into one or both of the host computer 1 and the computer 20 . Software 45 may include web-browsing capability (called browser software) as either operating system software 45 A or application specific software 45 B. One popular example is Microsoft's Internet Explorer.
To meet technology needs, the trading software 45 C of the present invention can be configured as a stand-alone (i.e., autonomous) system, or could be coupled to other presently-available commercial systems, of which there are numerous examples, such as the on Exchange Extensible Clearing System, owned by The Clearing Corporation of Chicago, Ill., or X_Trader®, owned by Trading Technologies International of Chicago, Ill., The Chicago Mercantile Exchange's Globex® Trading System, Electronic Broking Services (“EBS”), or many other such systems, any of which can be implemented on host computer 1 . In either event, it will be appreciated by those skilled in the programming art that trading software 45 C be configured to facilitate trading between host computer 1 and remote client device 20 in a manner consistent with the principles of operation disclosed herein. Furthermore, it is well within the skill of a programmer in the trading art to create the necessary software 45 C to accomplish the required listing, trading and record-keeping calculations. In addition, trading software 45 C can be provided on any computer readable medium, such as the memory storage device 30 discussed above, as well as on portable storage, such as compact disks, floppy disks, tape, flash memory or the like. It will be appreciated that the trading software 45 C can be configured to facilitate the trading of the novel options and futures contracts associated with the production of educational athletics. Accordingly, the invention disclosed is not limited to any specific embodiment of the computer programs (including trading software 45 C) disclosed herein.
Connection between trading software 45 C and a commercial electronic trading system such as those discussed above can be through means known to those skilled in the art, including internet connectivity or direct connectivity, the latter through such approaches as a T1 line, Ethernet connection, hybrid or other high-bandwidth line. Preferably, in situations where the trading software 45 C is being used as a front-end system with a larger electronic trading system, the two are fully compatible with one another so that, among other things, proper order entry and cancellation is ensured (as well as verification of same), proper connectivity, login, message sequencing is ensured, all critical market data and related information be received and displayed, be readily upgradable based on trading needs or changes in market conditions, and avoid disruptions to other markets that may be running simultaneously on the electronic trading system. An electronic trading system platform can be of either an open or closed architecture, where the former would enable ease of access to individual forms of trading software 45 , including situations where the trading software 45 C is proprietary. Since such systems are well known in the art, they will not be discussed in further detail.
In certain architectures, some functions are performed by the host computer 1 , while others are performed on the remote computer 20 . For example, in the client-server based approach, much of the graphics (and other memory-intensive data) can be pre-stored on the remote client computer 20 , thereby allowing the less cumbersome input and requests, as well as host computer 1 response, to proceed at a more rapid pace.
The host computer 1 may be equipped with a web server and appropriate web browser interface, as well as one or more databases 60 . As mentioned above, at least one form of software 45 is used for connecting to the web through various components, including a web browser and various servers, especially those for hypertext transfer protocol (HTTP), structured query language (SQL) and file transfer protocol (FTP), as well as an interpreter for script (such as Javascript). HTTP is the protocol used by the servers and their clients to communicate using HTML hyperlinks that upon clicking execute the hyperlink to retrieve the linked information. SQL is a popular language used to create, modify and retrieve tabular data (such as that used in relational database management systems). The HTTP server establishes and manages the connection to the internet as one form of network 15 , as well as maintain a web site. Pages used to convey the information may be written in conventional internet-compatible languages, such as extensible markup language (XML), standard generalized markup language (SGML), virtual reality markup language (VRML) or the aforementioned HTML. Web-accessible information is available between connected machines, and is identified by a uniform resource locator (URL) that specifies the location of a file containing such information in terms of a specific computer and a location on that computer. Any computer with an internet protocol (IP) address that is connected to the internet can access one or more files of web-accessible information by invoking the proper communication protocol and specifying the URL.
In one embodiment, computer 20 can be equipped to process Java or related machine-independent script instructions to facilitate the display of moving animation and related dynamic information. In addition, software components referred to as applets can be encoded in the script to interact with the trader locally to perform a specific function on the client computer 20 . These applets are transferred to the web browser that is loaded on computer 20 along with other web page information to be executed by the interpreter. These applets can further cause the web browser to retrieve information via hypertext links, thus data acted upon by the applet can be located on the same or a different web page (and even on a different server entirely). At the beginning of each trading session, trading software 45 C is preferably transmitted to or activated by each subscribing trader; in the case of the former, it is transmitted by the host computer 1 in the form of a feature-rich applet. The trading software 45 C enables the trader to display graphical user interface (GUI) screens such as those shown in FIGS. 3A through 3L on display 40 ; the trader may navigate through them using a mouse 35 or other conventional pointing device. Such device may be used to click on various HTML icons, as well as allow input into various fields information germane to a particular trade or the trader's account. Thus, by using these interactive locations displayed on these GUI screens, traders may submit dynamically written queries to data tables maintained by the host computer 1 .
Programs such as that used to facilitate the present trading system may be provided by the host computer 1 upon an appropriate log-in sequence by a user of the computer 20 or as part of a downloadable package that is provided to the user once that user subscribes to exchange of the present invention. Such programs can be written in any well-known internet-compatible language, such as Dynamic HTML, Active X, or the aforementioned Java. These languages allow internet publishers to create complex multimedia web pages of text, graphics, tables, buttons, images, sounds and videos each identified by an HTML tag that define the above-mentioned functions. Possible trader interfaces may include HTML pages, Java applets and servlets, Java or Active Server pages, or other forms of network-based GUIs known to those of skill in the art. In one example, traders connected through the internet can submit HTML requests via Java Remote Method Invocation (RMI), a Java application programming interface for performing remote procedure calls, or Internet Inter-Orb Protocol (IIOP), an implementation of the more abstract Global Internet Inter-Orb Protocol (GIOP). Both RMI and IIOP can run on top of the standard TCP/IP protocol.
In operation, the remote client computer 20 , in response to instruction from trader input, executes a buy or sell order by communicating the trader's input with host computer 1 . Display 40 is configured to show data from database 60 in graphical or related user-friendly format. Database 60 may be situated in memory 30 , or may be intermittently fed to host computer 1 or remote client computer 20 through periodic updates from a data and information service, such as a trading information service or the like. The host computer 1 includes (in addition to many of the attributes previously discussed in conjunction with the remote client computer 20 above) the ability to send, receive and operate on information contained in databases 60 ; such information may include contract identifier information (for example, the name of the non-rival athletic program contract within a particular educational institution being traded), price, quantity presently available on the exchange, news or other such information that a trader may find useful. The software 45 resident on or otherwise used by host computer 1 may be similar to, or have different features from, the software 45 of the remote client computer 20 , so long as communication and trade execution between the host computer 1 and remote client computers 20 are not adversely impacted.
Trading software 45 C can, among other things, manage individual trader accounts, receive trader input, match bids between traders, then execute, clear and settle all trades. The trading software 45 C may also include security measures to ensure that all transactions are protected. In one form, the trading software 45 C may be executed by the host computer 1 , although in alternative embodiments, such software may also be executed on the remote client computer 20 . The databases 60 can be utilized to reproduce the information available in a traditional floor-trading system, as well as to maintain dynamically updated information of all pertinent trading information and data on an individual institution's non-rival athletic program. Additional updated information on exchange subscribers and their accounts, as well as a history of all bids (including quantity, price, date and time of receipt, trader identification, and trade status) may also be maintained by the host computer 1 . The software 45 C may also process data from individual or aggregate trading activity in the system 10 to provide other information that a trader may find useful, including contract volume, past and current market and contract history, as well as market concentration and volatility.
Trading software 45 C may include an applet that has means for accepting and verifying user input, and means for transmitting that user input to the host computer 1 , enabling the user to engage in trading activities. Such input may include logging onto the system 10 , navigating a web site through HTML page requests, viewing market data and news, making trades on futures contracts and monitoring an investment. This, coupled with all of the aforementioned security, accounting and related functions allows trading software 45 C to be configured to handle most, if not all, of the trader's needs. Thus, for internet-based access and trading, the only application software 45 B (besides trading software 45 C) needed on the computer 20 is a conventional web browser, although it will be appreciated that other software (such as operating system software 45 A) is typically also present.
Some of the electronic or screen-based commodity trading systems in use today require a broker, specialist, telephone operator or other intermediary between the trader and the trading floor, while others are fully automated so that traders can complete a trade without the need for such intermediaries. Either form is compatible with the system and method of the present invention, although the fully automated approach has the potential to reduce the likelihood of human error or abusive trading practices in the execution, clearing and settlement of trades. Likewise, an automated system advantageously allows for automated record-keeping.
Referring next to FIG. 3A in conjunction with FIGS. 1 and 2 , when a user first connects to the host computer 1 of system 10 , a welcome screen 400 shows up on display 40 of computer 20 , revealing a banner 4002 and numerous icons (or buttons) in the form of HTML links, including one 4004 that can describe the basic services offered by the present exchange, one that will lead to a current list of the most active (i.e., most widely-traded) contracts 4006 , as well as new subscriber (i.e., member) registration 4008 and present member log-in 4010 . For example, if a user wants to find out which institutions' non-rival athletic programs have been the most actively traded, he or she clicks on the icon 4006 , which routes the user to the appropriate screen as described in more detail below. HTML links 4012 , 4014 and 4016 may also be used for various commercial entities that purchase advertising space that appears on the screen 400 . Additional icons 4018 can also be used to provide information regarding contacting the operators of the exchange, explanation of non-rival athletic program commodities, a homepage or the like. It will be appreciated by those skilled in the art that the precise arrangement of icons on the screens can be varied, according to aesthetic or functional needs. For example, in an alternate version, the screens can include fewer icons to present simplified choices for the trader.
By clicking on the present member log-in icon 4010 , the trader is routed to a log-in screen 410 . Some of the screens (including screen 410 ) contain interactive fields that allow the input of user-specific information into computer 20 . Screens with fields for input are referred to as form pages, where the input fields enable information to be sent to an HTTP server for further action. Referring next to FIG. 3B , screen 410 includes, in addition to a banner 4102 which may or may not be generally similar to that of welcome screen 400 , fields 4104 , 4106 where the subscribing trader can provide an identifying username and password, then click on the log-in icon 4108 . This instructs the browser to post the information contained in the fields back to the HTTP server, which analyses the incoming data and looks for information to instruct it how to deal with the trader's request. The HTTP server passes a script file (not shown) from the HTML page to a script interpreter, which extracts input tag information and forwards it to the program instructed by the script file. By way of example, the script file may instruct the script interpreter to have the SQL server write the passed information to a database stored on the local memory storage device 30 . The script file could further instruct the script interpreter to request information from the database, in which case the SQL server extracts the requested information and then passes it back to the HTTP server for use by the web browser.
If the trader has forgotten his or her password or username, he or she can click on the links 4110 , 4112 , which will redirect the trader to another screen (not shown), where the trader will be queried to provide secret information (such as a social security number in conjunction with a mother's maiden name or the like, based on an earlier question provided during registration), after which the host computer 1 will mail back a new username and/or password to the e-mail address provided in the user's registration database. Prospective (i.e., new) members may register on-line for the service provided by the present invention by clicking on an icon 4008 which will reroute the user to one or more registration screens (not shown), which may query the registrant for information that will be used to set up a new account. Part of the registration process includes the registrant choosing a unique username and password, both of which will be used for subsequent log-in after registration. By providing an e-mail address, the registrant can receive additional registration and related instructional information. The registrant will have the option of funding the account on-line, or through various conventional ways (such as check, wire transfer, money order or the like). Once the registrant receives a password and has appropriately funded the account, he or she may begin trading up to the amount of such funding.
Referring next to FIG. 3C in conjunction with FIG. 2 , once the trader is logged-in as an authorized user, he or she is greeted with a home screen 420 that identifies the trader by name 4202 that was provided during registration. Furthermore, once the trader username and password have been verified by the host computer 1 as identifying a subscribing trader, the host computer 1 transmits for viewing on the display 40 the trader's personal account information obtained from database 60 . Such information could be displayed directly on screen 420 , or can be accessed by clicking on one or more icons, such as icon 4204 , 4206 , 4208 or 4210 . By having the trader be properly logged-in and verified, all subsequent transaction data transmitted back and forth between the host computer 1 and the logged-in remote client device 20 is associated with that unique trader. Authentication devices, such as cookies residing in the remote client device's 20 HTTP browser (which can be transmitted to the HTTP server of host computer 1 ) may also be employed to ensure security. Such a system of identification and security allows the system 10 to reliably identify data inputs that are have been generated by a unique and approved subscribing trader.
Icons near the top of the screen 420 can be used to provide general information. For example, if the member is desirous of changing password, he or she can click on the change password icon 4216 , which will lead to another screen (not shown) with another set of instructions. It will be appreciated that features such as the change password icon 4216 could be placed in other suitable locations, as well as on other screens. In addition to the screen 420 displaying the trader's personal account summary 4204 , available funds 4206 , recent trades 4208 , open (i.e., unfulfilled) contracts 4210 and important dates relating to the NLI process 4212 for various sports, it has an icon 4220 that allows the trader to select a particular educational institution in which he or she may be interested in trading. Such choice sends the trader to screen 430 , discussed in more detail below. Optionally, screen 420 can include updates to one or more non-rival athletic programs of particular interest to a trader. Such information can be in the form of a moving ticker or banner 4218 that scrolls across the bottom of the trader's screen 420 . Thus, for example, if a trader who is an Ohio State fan wants to keep tabs on futures trading of Michigan's non-rival athletic program, he or she can enter such target programs in another screen (not shown); the exchange will store this information in database 60 , or can retrieve it from another source, such as market data feed 80 , and will automatically forward information pertaining to SYM MICHIGAN to the trader's screen 420 . Those skilled in the art will appreciate that such information can be provided continuously, or as important triggering events occur.
It will be appreciated by those skilled in the art that selection of a particular non-rival athletic program through icon 4220 can proceed in any order. Once the non-rival athletic program icon 4220 is selected, the trader is routed to screen 430 , which is shown with particularity in FIG. 3D . A banner 4302 indicates to the trader that a list of all the non-rival athletic programs that have futures contracts available for trading. From this list or field 4304 (which includes HTML features), a particular non-rival athletic program 4304 A may be selected merely by clicking on the name of the desired program. In the event the trader does not know the name of the program, a search aide icon (not shown), which may be based on a program name, state, city or the like, may be included.
By selecting the name of a particular non-rival athletic program 4304 A from screen 430 , the trader is routed to screen 440 , as shown with particularity in FIG. 3E . In addition to a trading icon 4402 , icons 4404 and 4406 that are unique to the non-rival athletic program chosen from screen 430 can be selected, so that the trader can get publicly available news, statistics, schedules, recruiting or related information that the trader may find useful. With regard to the chosen non-rival athletic program (again, SYM OHIOSTATE in this example), other information, such as that shown in fields 4408 A-E give the trader the most up-to-date information on what the current bid and ask price, as well as last price, change and cumulative volume (which can be measured in any convenient metric, such as total dollar value or the total number of futures contracts of all traded SYM OHIOSTATE contracts in the current period) can also be shown. As with other information provided to the trader from the exchange, the trading information of fields 4408 A through 4408 E is updated periodically (for example, continuously to ensure real-time or near real-time delivery), based on input from the market data feed 80 or database 60 . Details pertaining to futures contracts can be displayed in field 4410 , including the date that the contracts expire. An overview of a trading histogram 4412 may also be shown, covering a length of time (for example, day, week, month or season-to-date) chosen by the trader.
By clicking on the trade icon 4402 , the trader instructs the exchange to proceed to the trading screen 450 . Referring with particularity to FIG. 3F in conjunction with FIG. 2 , the user may buy or sell non-rival athletic program futures by clicking on the appropriate icon 4502 , 4504 . To help the trader quickly ascertain the price status of the program at issue, fields 4508 and 4510 show the current bid and ask values, respectively. A histogram 4506 depicting price fluctuations over a recent period can additionally be used to inform the trader. As trades are made, the screen of each logged-in trader can be continually updated (for example, at preset intervals, or upon a preset or otherwise significant change in a particular program's price or other measurable parameters), thereby enabling each trader to make further trading decisions based on up-to-the-minute information regarding current contract prices and trade volume. The status of an open contract can be updated automatically (through for example periodic automated updates sent from host computer 1 ), including volumes and prices, as well as trends to help keep a trader informed. Subscribing traders also have the option of submitting dynamic queries to the host computer 1 at any time.
If the trader is interested in buying futures contracts on the institution (again, using SYM OHIOSTATE as the example), he or she clicks on the buy icon 4502 . When this happens, the exchange sends the trader to screen 460 , which is shown with particularity in FIG. 3G . This screen gives the trader the opportunity to input desired price and number of contracts in fields 4602 and 4604 , subject to funding availability as previously discussed. Once these values are entered, the submit icon 4606 is clicked. This directs the trader to a verification screen 470 , shown with particularity in FIG. 3H , that asks the trader to verify the price and quantity of futures contract that were entered from the previous screen 460 . In addition, the exchange is checking the trader's account for an adequate deposit in his or her account to enable the requested trade. If the trader's funds are insufficient, a message can be sent from the host computer 1 to the remote client device 20 altering the trader of the shortage. In addition, immediately upon receiving an order and entering it into the database 60 , the host computer 1 sets up a reserve against each new order. This reserve can be in the form of a deposit placed in the trader's account. Furthermore, the host computer 1 can update each trader's account upon the occurrence of any action against that trader's account. In such way, the host computer 1 will not perform any trade that would cause a trader's account to become overdrawn, thereby eliminating a major source of account errors. If the values shown in fields 4702 and 4704 are in agreement with the trader's expectations, the trader clicks an appropriate verification icon 4706 A, which then sends the trader to screen 480 . If the values displayed are not in accordance with the trader's expectations, icon 4706 B can be pushed, thereby sending the trader back to the input fields 4602 , 4604 of screen 460 .
If the displayed information is correct, and the trader clicks on icon 4706 A, the trader is forwarded to screen 480 , shown with particularity in FIG. 3I . The trader receives confirmation of a placed order on screen 480 , with indication of the name, number and price of contracts bought or sold. Icon 4804 gives the trader the option of instantly cancelling the just-placed order, as long as it has not been accepted, as indicated by notice 4812 . As stated before, there are various ways of facilitating the trade. For example, trading can occur in either a bid-matching exchange format or a variation of a pari-mutuel format, where the following discussion is based on a bid-matching form of exchange. The host computer 1 processes the trader's order by placing it in memory, such as that of memory storage device 30 . The order is a data structure that may include, among other things, a trader's name, account number, time and date of the order, nature of the contracts bought or sold, and cash balance in the account. An icon 4814 for cancelling open contracts can be clicked; this opens a dialog box (not shown) that contains a listing of that trader's active contracts, as well as the ability to pick and choose (such as by clicking or otherwise highlighting) what trades to cancel. As with buying contracts, cancellation of a presently open position requires a verification step somewhat analogous to what was previously described. Upon the confirmation of the trader's order, the transaction data is compiled and transmitted to the host computer 1 , preferably using the aforementioned encryption means. Upon submission of the original order by the remote client device 20 , the exchange reserves or withdraws from the trader's account the funds that would be needed to finalize a trade based on the order.
Once the trader's order has been placed, the exchange searches the database 60 for any reciprocal open contract. As stated above, in one form, database 60 may reside in memory storage device 30 . The database includes a comprehensive, dynamically updated listing of all orders placed in the system, including price, quantity, when placed, trader and order identification, and bid status. In one form, records of trades in database 60 can be in the form of a lookup table. The exchange creates a new record, assigning it a time-stamp and an open (i.e., unfulfilled) status identifier to indicate that the order is available to be matched. As indicated by language 4802 on the screen 480 , the exchange sends confirmation that the system 10 has entered the submitted order, confirming the values specified by the trader for price and lot size. Additional language indicating that the order is open, and that the trader will receive notification upon completion of the order, is also provided. Icons 4806 and 4808 can be used to allow the trader to proceed with another trade while waiting on the results of the previous trade. For example, icon 4806 can be used to do more trading on the present athletic program (shown as Ohio State in FIG. 3I ), while icon 4808 can be used to switch to another institution or athletic program. Thus, in this latter case, by clicking on icon 4808 the trader could be rerouted to list or field 4304 of FIG. 3D , while in the former, by clicking on icon 4806 the trader could be rerouted to screen 440 shown in FIG. 3E .
Returning again to FIG. 3F , if the user wishes to sell a futures contract, he or she follows the same procedure discussed above in conjunction with the “buy” transaction, except instead of clicking on the buy icon 4502 , he or she clicks on the sell icon 4504 . In situations where an investor is attempting to become a market maker, the exchange can check for an adequate deposit to cover the investor's position. The software 45 C can be used to run a check against the investor's account to ensure that such deposit is in place. In both the “buy” and “sell” scenarios, security (such as encryption) is preferably incorporated to ensure the integrity of the communication regardless of whether the order is a buy or sell.
In a configuration set up as a first-in, first-out order-matching scheme, the time and price can be made the determining factors. For example, all orders at the same price can be filled according to time priority. It will be appreciated by those skilled in the trading art that other approaches or algorithms may be used. For example, in a market-maker algorithm, where trading liquidity may be enhanced by the presence of a trading concern that can establish and maintain a two-sided market, the concern can be given a guaranteed allocation of any incoming orders in return for complying with market obligations that may be defined by the exchange. In another example, pro rata order matching approaches may be used, where orders are filled in accordance with price priority. In such case, the first order with a price priority will be given matching priority, with all others (at that price) will be at least partially filed, depending on the available quantity of remaining orders.
With particular regard to the first-in, first-out market matching scheme, if the exchange, in searching the database 60 for a match, does locate one or more matching orders, it selects the matching order with the earliest time-stamp. The exchange then compares the orders in database 60 to determine if they specify the same or a different lot size; if the number of contracts specified is the same, the exchange completes the order and sends an indication to the relevant traders that the contract has been filled. If the lot sizes differ, the exchange calculates the difference in lot sizes and matches the trader's order with the available lot number of open and reciprocal contracts. The process can be repeated by searching the opposing orders on a first-come-first-serve basis until a match is found, or until the trader cancels the order. If after a certain period of time no matching order is found, the exchange can optionally proceed to enact a partial fill of the order. This can be done at the trader's request (based on, for example, a query from the host computer 1 ), or automatically, depending on which option the trader selects during setup (not shown) of his or her account. For example, if an open contract to purchase one hundred futures of SYM OHIOSTATE could be matched with an open contract to sell fifty shares of SYM OHIOSTATE at the same price, the exchange can match the first fifty of the purchaser's contracts with the fifty seller's contracts, thereby completing that contract while leaving the remaining fifty purchaser's contracts for a later match. Thus, where an opposing order is submitted at a complementary price, but for a different number of contract units, a match is preferably still declared, and is effectuated for the lesser of the two numbers of units specified by the two traders. This results in filled contracts for each trader for the lesser number of contracts, as well as an open order for the contract units remaining unfilled. Once any trade has been completed (i.e., fulfilled), the host computer 1 sends confirmation to the remote client device 20 , instructing the GUI to show the results of the transaction on the trader's display 40 . This confirmation results in a screen display 490 , itemizing the number of contracts filled, the price, and the option to trade additional contracts. This is described in more detail next.
Referring next to FIG. 3J , whenever a match has been made, the exchange's trading software 45 C proceeds to notify the trader of the filled trade, as shown in field 4902 . Field 4906 gives the trader the option to look at details related to the trade by clicking on an HTML word, such as the word “HERE” in the field. The exchange automatically performs all clearing and accounting processes needed to complete, guarantee and confirm each trade. The accounting completes the transaction and credits and debits the respective account balances of the traders who are parties to the transaction. The exchange determines whether any portion of the recently filled contracts offset an existing position in that trader's account. The exchange determines the trader's overall position by counting the total number of filled contracts. The exchange determines if the number of filled contracts on both sides are equal, and if so, debits the trader's account in the amount previously reserved for the current order, less the amount allocable to any unfilled contracts still remaining.
If the trader's overall position is not neutral, the exchange determines whether such position shown is offset by an opposing position of the newly filled contract. If the newly filled contract does offset the trader's preexisting position, the number of new contracts filled is subtracted from the open position, and the trader's account record is accordingly updated. In such case, the trader's account is credited by multiplying the contract value by the number of offsetting filled contracts, less the trading fees associated with the filled contracts. Imbalances in traders positions are maintained until offset through additional trading activities or by final settlement at the end of the trading period.
After account balance checks by the host computer 1 , the reserves earlier withheld by the host computer 1 from each trader's account are now applied to clear and to settle the trade. Trading fees or commissions are charged at this time to the account of each matched trader according to predetermined contractual terms, and the accounts of the matched traders are debited or credited accordingly. All data pertinent to the trade is recorded by the host computer 1 to database 60 . Position and account information are updated to give the trader a complete set of information pertaining to the trade. This can be valuable for record-keeping, as well as indicia of the terms of the trade in the event of any dispute. Screen 490 also includes icon 4904 that allows the trader the option of pursuing additional trades. In this manner, icon 4904 can be made to function similarly to that of icons 4806 or 4808 from screen 480 in FIG. 3I .
By way of recap, one or more traders enter their orders through trading software 45 C or related front-end trading application. A submitted order is deemed to be accepted once the software 45 C has confirmed order validity, time-stamped the order and sent acknowledgement of the order to the trader. Accepted orders can be kept in a centralized order book (which may also be resident on host computer 1 ), where an entered order is matched to a complementary order from another trader. Depending on the algorithm making up the software 45 C, part or all of the order may be executed in one of the manners discussed above. For example, in situations where orders are not completely executed, the order time-stamp may be used for subsequent order prioritization, if time priority is a factor in the algorithm. Once a trade has been executed, the user receives the contract fill information, which is also sent to a clearing system (which also may be resident on or cooperative with the host computer 1 ) for post-execution processing.
Referring next to FIG. 3K in conjunction with FIG. 2 , an information screen 500 can be used to inform traders of the most actively traded programs, as shown in table 5002 . Various forms of information, including the name of the institution, trading price ranges and trading volume and other data may be presented. In addition to providing other icons that allow the viewer to register for an account, ask questions or the like, the data contained in table 5002 can be in HTML form, so that (in the event the viewer is already registered) if the viewer wants to trade on a particular institution's non-rival athletic program, clicking on the appropriate program name makes a direct link to that particular program.
Referring next to FIG. 3L in conjunction with FIG. 2 , in situations where the trader is also a qualified prospect or a qualified institution, a different screen 510 can be used. As stated before, a prospect or an educational institution may become qualified by entering into a binding agreement (such as an NLI or other contract) with one another. In a manner generally similar to that of screen 420 for other traders, screen 510 identifies qualified prospects and qualified institutions by the name 5102 that was provided during registration. A significant difference over screen 420 is the option icon 5104 that gives the qualified prospect and qualified institution the additional ability to exercise options to buy allotted futures contracts at a predetermined strike price. Once the qualified prospect or qualified institution has paid the option premium (for example, $100) and purchased futures at a fixed strike price (for example, $1), they gain the right to sell some or all of their allotted futures contracts (for example, up to one thousand futures) at the market price, assuming a matching buyer can be found in a bid-matching arrangement. Other icons, including account summary 5106 , available funds 5108 , open positions 5110 and recent trades 5112 can be used to keep the trading prospect up-to-date on the status of his or her account.
Regardless of how the companion market is structured relative to the primary market, the subscribing trader will be able to use the same exchange through the same interface, performing the same operations and using the same account. In other words, the operation is transparent to the trader, although it will be appreciated by those skilled in the art that minor variations in screen displays to best implement one of the variations discussed above are possible.
EXAMPLE
The following example can be used in order to better elucidate the concepts of the present invention, using a dual (i.e., primary and companion) market approach. In the example, a first Ohio State fan desires a highly touted football prospect to sign an NLI Commitment with Ohio State and has read on a recruiting web site that the prospect has narrowed his college choices to Ohio State and Michigan. The first Ohio State fan bids $20 for each of fifty SYM OHIOSTATE futures. On this same date, a current Ohio State player, whose position the prospect may be seeking in the fall, exercises some of his options, buys fifty futures at $1 apiece, and sells these futures to the first Ohio State fan. The Ohio State University does the same with a second Ohio State fan, and both the player and The Ohio State University realize an $850 profit (fifty futures times $20 per future less a $100 premium for option and the fifty $1 strike prices per future) and exit the market. Note that the $850 profit, as well as all profits discussed in this example, do not take into consideration the transaction fees (i.e., those fees charged by the exchange to complete the trading transaction).
The first Ohio State fan searches the market for other investors who believe the market for SYM OHIOSTATE futures has not reached the top. If the first Ohio State fan finds yet another Ohio State fan or an Ohio State speculator willing to pay more than $20 per future (perhaps because the price of Michigan futures and Penn State futures has increased to $25 each), then the first Ohio State fan sells his or her futures and exits the market, making a profit commensurate with the difference between what he or she was able to sell for and what he paid.
The first Ohio State fan also can hedge the risk of holding those futures by trading index futures on a companion market. For example, the same day the first Ohio State fan purchased the futures, the aggregate mean price per future (i.e., the aggregate price of all of the participating institutions) is trading at $15 per future. Given that the first Ohio State fan knows that he paid $20 per future, the first Ohio State fan speculates that the aggregate mean index future price will increase and hedges his purchase of Ohio State futures by buying 200 index futures at $15 per future.
On the subsequent NLI signing day, the prospect sees that SYM OHIOSTATE futures are trading at $20 while Michigan futures are trading only at $18 and the prospect, after weighing the respective futures prices, the academic programs, the coaching staff, the traditions, the athletic opportunities and other factors, chooses Ohio State. In addition, the aggregate mean index future price settles at $20 with a price per future payout of $5 per future for traders who speculated that futures would settle above $15 per future. The first Ohio State fan is satisfied: He has helped secure the prospect for Ohio State. In addition, the first Ohio State fan's gain on his index future trade (200 index futures×$5=$1000) offsets a potential $1000 loss on his purchase of 50 SYM OHIOSTATE futures at $20 per future in the primary market.
The final report card of the results of all these transactions is as follows: (a) The Ohio State University realizes $850; (b) the player realizes $850; (c) the prospect chooses Ohio State in part because the fans have demonstrated that they will support the non-rival Ohio State athletic program he will soon join; (d) the first Ohio State fan breaks even economically, but realizes the gain of Ohio State signing the prospect to an NLI Commitment. Lastly, the exchange collects transaction fees on the trades in the primary market and companion market of The Ohio State University, the player, the first Ohio State fan, the second Ohio State Fan and distributes a percentage of the transaction fees to the general scholarship funds of all institution's sponsoring non-rival athletic programs that are traded on the exchange.
The above example highlights one of the trading scenarios possible with the system and method of the present invention. As will be appreciated by those skilled in the art, other examples, using one or more of the exchange variations discussed above are also possible and fall within the scope of the present invention. Accordingly, while certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention, which is defined in the appended claims.
|
A device and method for trading commodity options and futures related to an educational institution's non-rival athletic program to manage risks associated with producing collegiate athletic programs. In one version, the underlying asset of the options and futures contracts is an athletic prospect's obligation to participate in a non-rival athletic program at a particular institution in exchange for the opportunity for the athletic prospect to participate in academic and athletic programs within the institution. In a particular form, the underlying asset is a signed National Letter of Intent, a contract that obligates a prospect attending a particular institution to participate in that institution's non-rival athletic program. Revenues generated by options and futures contracts traded according to the device and method of the present invention can be used to further the institution's educational and athletic missions.
| 6
|
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
All patents and publications described or discussed herein are hereby incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
The present invention relates to an improved panel. More specifically, without limitation, this invention relates to a panel made for use in portable flooring, folding tables, risers/platforms/event staging, and wall partitions.
There are numerous industries that use portable equipment and items in the preparation and production of events associated with those industries. The portable equipment used in and at these events are typically assembled and/or positioned prior to the event and removed after the event to allow alternate uses and/or different arrangements of the event venues. Examples of types of equipment that are assembled, moved and/or positioned during these events include portable flooring (such as dance floors, tent floors, stadium floors, etc.), folding tables, bench seating, event platforms/risers/staging, walls, and wall partitions.
For each of these various pieces of equipment, one of the general desirable characteristics is a generally planar shaped surface on which people and/or items will walk, stand, or are placed. Other desirable characteristics include high surface and structural durability, light weight, ease of assembly and disassembly, waterproof, various aesthetic patterns, images, and/or colors on the planar surfaces, and cost effective equipment pieces. To this end there have been numerous attempts in the art to construct various portable tables, portable floors, and the like. Examples of these attempts include U.S. Pat. Nos. 2,490,577, 2,849,758, 2,907,127, 2,911,274, 3,310,919, 3,323,797, 3,450,593, 3,512,324, 3,567,260, 3,582,447, 3,630,813, 3,676,279, 3,826,056, 3,868,297, 4,144,681, 4,353,947, 4,522,284, 4,645,171, 4,680,216, 4,879,152, 4,931,340, 4,973,508, 4,988,131 5,006,391, 5,070,662, 5,061,541, 5,154,963, 5,288,538, 5,348,778, 5,496,610, 5,569,508, 5,626,157, 5,634,309, 5,667,866, 5,776,582, 5,888,612, 5,947,037, 5,972,468, 5,992,112, 6,061,993, 6,117,518, 6,128,881 6,189,283 6,227,515, 6,235,367, 6,253,530, 6,446,413, 6,445,131, 6,505,452, 6,526,710, 6,743,497, 6,753,061, 6,761,953, 6,837,171 and 6,865,856. These patents are directed at various designs for tables, panels, locking mechanisms, portable flooring and the like. These patents use less than ideal methods to construct the substantially planar surfaces and connect these surfaces.
For example, in the portable flooring industry conventional flooring panels and the methods for making the same have several drawbacks. One type of typical conventional construction includes using oriented strand board or plywood cut to a preferred size from a large blank as the core structure. The perimeter of this core is machined to provide a contour to accept an edge and the core is coated on one side with a protective film for moisture protection. An edge structure is cut to a desired length and machined to facilitate assembly to the core. Then vinyl or wood parquet tiles are manually placed with adhesive glue onto one of the planer surfaces and then pressed and cured for somewhere between six to eight hours. The excess glue is cleaned off and the locking hardware is attached around the exterior.
An alternate conventional method of making the panels includes cutting a foam core to the preferred size and machining it to provide space for the locking hardware. Steel skins are cut and sized to fit over the foam and are glued to the foam core. A laminate skin is glued to the steel skin and then the panel is pressed and cured. Then the panel is placed into a mold wherein an elastomer edging is molded around the panel perimeter. The locking hardware is installed once the panel is removed from the mold.
Both of these conventional methods result in either very heavy panels that are difficult to transport or panels susceptible to water damage. Both of these methods are labor intensive, while the show surfaces, or show skins, of these panels are susceptible to glue failure rendering these panels disfigured and/or unusable.
What is needed then is a new panel and method for making the same that combines a light weight and durable construction for easy and convenient transport together with the ability to withstand the adverse affects of water and prolonged product life in use. The preferable panel is manufactured with more cost effective, less labor intensive methods to make the panel affordable to a broad cross-section of the market. This needed panel is lacking in the art.
BRIEF SUMMARY OF THE INVENTION
Disclosed herein is a portable panel having numerous favorable characteristics. The panel comprises a core having a length, a width, a first side and a second side. A first fiber layer is attached to the first side while a second fiber layer is attached to the second side. A first polyurethane layer is impregnated in the first fiber layer while a second polyurethane layer is impregnated into the second fiber layer. A first outer skin is attached to the first polyurethane layer while a second outer skin is attached to the second polyurethane layer. Each of these steps can take place individually then the composite is placed into a press for a cure cycle.
Also disclosed is a table comprising support legs and a planar surface attached to the support legs. The planar surface includes a core having first and second fiber layers attached on first and second sides of a core. First and second polyurethane layers impregnate the first and second fiber layers, respectively, while first and second outer skins are attached to the first and second polyurethane layers, respectively. Each of these steps can take place individually then the composite is placed into a press for a cure cycle.
Also included is a portable floor comprising a plurality of panels. Each panel includes a core having first and second sides. The first side has an attached first fibered layer impregnated by a first polyurethane layer and a first skin attached to the first polyurethane layer. Attached to the second side of the core is a second fiber layer impregnated with a second polyurethane layer having a second skin attached to the second polyurethane layer. A frame surrounds the core wherein the frame includes two male sides and two female sides. The female sides include an engaging location and a channel having a channel length substantially equal to the core length. The male sides include a protrusion shaped to engage the channel and a locking mechanism. The protrusion has a protrusion length substantially equal to the channel length.
Also included is a method of constructing a panel. The method comprises providing a core, attaching a first fiber layer to the first side of the core, and attaching a second fiber layer to the second side of the core. The method further includes impregnating first and second polyurethane layers into the first and second fiber layers, respectively, and preferably immediately attaching a first skin to the first polyurethane layer and a second skin to the second polyurethane layer. The entire composite is then placed in a press where it cures for a period.
Also included is a method of preventing lateral panel movement when a floor is assembled. The panels are secured together by the cam locks which are located in the male extrusion lengths. The method used to prevent the panels from sliding laterally is accomplished with apertures located on the male side in the section cutout for the lock to receive two protruding pieces, such as cap head screws, located on the female side.
The integration of light weight panel technology into a series of products with specific advantages in production and use is taught with this disclosure. The inventive panels relate generally to a process of polyurethane construction using combinations of fiber layers arrayed on both sides of a light weight core material with external skins bonded integrally to the polyurethane layers. The various layers can be bonded to both sides of the panel through the polyurethane polymerization process.
Advantages of the panels of the current invention, as compared to those of the prior art, include a waterproof characteristic and a lighter weight panel that facilitates transportation and assembly. The current invention can have a reversibility option with multiple patterns, designs and/or color options on the opposing sides. The various layers and skin have superior adhesion due to the impregnation and attachment of the skins during the curing process and the superior adhesive characteristics of polyurethane. The inventive panels have a substantial labor saving cost and specifically do not require a mold for their construction. This is an advantage since the use of a mold can severely restrict the economics of producing large panels and requires significant capital investment for the molds and presses. A mold also requires cleaning and maintenance both of which add to cost and time for the production of the panels. As such, the elimination of the use of a mold in panel construction can greatly reduce the production time and increase cost savings during the production of the inventive panels.
For example, the molds discussed in some of the prior art, namely U.S. Pat. No. 6,761,953 use an open mold containing the outer layer and optionally the decorative layer. The prior art fails to place the layers on to the composite materials outside of a press and without a mold. The production of the current inventive panels is facilitated by the flat geometry of the parts and the use of a pre formed perimeter enclosure, such as aluminum or elastomer edging. The elastomer edge can provide part shape opportunities that are not possible with extrusion.
Additionally, the inventive panels can be approximately 30% thinner than the existing panels which can enhance the safe use and operation of the panel. For example a thinner panel reduces the likelihood of trips and falls caused by the thickness of the panels when laid flat and used in a portable flooring embodiment. Additionally, the exterior surfaces on the inventive panels are superior in terms of wear, durability, and maintenance thereof. Additionally the panel lateral movement suppression system is a unique, cost effective, and practical method to prevent the panels from sliding when engaged.
The inventive panels can have various applications in numerous industries. These industries include hospitality and entertainment industries such as: hotel, recreation centers, banquet halls, conference centers, stadiums, schools, outdoor activities with and without tents, and other similar facilities/locations. For example, portable flooring made in accordance with the current inventive panels can be set up and used indoors or outdoors with minimal assembly and disassembly time. These inventive panels facilitate these applications due to their strength, durability, waterproof nature, light weight, and positive interconnection between adjacent panels. For example, dance floors, tent floors, stage floors or other portable flooring applications can be ideally made using the inventive panels. Flooring so made can include a perimeter composed of an elastomer or extruded metal framework using tongue and groove profiles for panel interconnection. Alternately at least one of the sides can be shaped to interact with supporting feet and/or legs used to facilitate the upright placement of the panels, such as in a wall configuration.
It is therefore a general object of the present invention to provide an improved panel.
Another object of the present invention is to provide a method for making an improved panel.
Still another object of the present invention is to provide an improved panel that can be used in the making of a portable floor, folding tables, risers, event staging, and wall partitions.
Another object of the present invention is to provide portable flooring system having a lateral movement suppression mechanism positioned to restrict movement of panels relative to adjacent panels in the portable flooring system.
Still another object of the present invention is to provide a panel having multiple show surfaces that can vary in appearance, design, texture, color, and the like.
Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon reading of the following disclosure when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is an expanded perspective view of a panel made in accordance with the current disclosure and used in connection with portable flooring.
FIG. 2 is a top perspective view of portable flooring made in accordance with the current disclosure.
FIG. 3 is a bottom perspective view of FIG. 2 .
FIG. 4 is a detail view of the area circled and labeled as 4 in FIG. 2 .
FIG. 5 is a detail view of the area circled and labeled as 5 in FIG. 3 .
FIG. 6 is a top view of a portion of the frame for a portable floor made in accordance with the current disclosure.
FIG. 7 is a side end view of FIG. 6 view showing the male and female sides of the frame engaged.
FIG. 8A is a top perspective view showing a female side of the frame.
FIG. 8B is bottom perspective view showing a female side of the frame.
FIG. 9 is a side end view of the female side of the frame.
FIG. 10A is a bottom perspective view showing a male side of the frame.
FIG. 10B is a top perspective view showing a male side of the frame
FIG. 11 is a side end view of the male side of the frame.
FIG. 12A is a cross-sectional view of the male portion shown in FIG. 11 .
FIG. 12B is an alternate cross-sectional view of the male portion shown in FIG. 11 .
FIG. 13 is an expanded perspective view of a table top made in accordance with the current disclosure.
FIG. 14 is a perspective view of a table made in accordance with the current disclosure.
DETAILED DESCRIPTION OF THE INVENTION
Referring generally to FIGS. 1-14 , a panel is shown and generally designated by the numeral 10 . The panel 10 has many uses and can be used in conjunction with a portable floor, as seen in FIGS. 1-12 , a portable table, as shown in FIGS. 13 and 14 , risers, bleachers event staging, walls, and the like.
The panel 10 will have a core 12 . The core can be made from many materials including paper honeycomb, plastic honeycomb, polyurethane, EPS, wood, metal, and the like. The core can preferably include a plurality of openings 14 wherein the openings are substantially uniformly spaced along the width 11 and length 13 of the core. The openings 14 can be honeycomb in shape as best seen in FIGS. 1 and 13 .
First and second fiber layers 16 and 18 are attached to the first and second sides 15 and 17 of the core 12 . First and second polyurethane layers 20 and 22 impregnate first and second fiber layers 16 and 18 respectively. First and second skins 24 and 26 are attached to the first and second polyurethane layers 20 and 22 , respectively.
The first and second skins 24 and 26 , which can also be first and second laminate skins, are attached to the polyurethane layers before the polyurethane layers dry. This creates a strong bond between the skins and the polyurethane layers to increase the durability and attachment thereto. Additionally the impregnation of the polyurethane layers through the fiber layers increases the strength and bonding of the polyurethane layers and skin to the fiber layers and a core upon which they are attached. Prior to application of the polyurethane the fiber layers 16 and 18 are attached to the core 12 . For example, staples, glue or other fastening systems known in the art to attach fiber layers to a core layer can be used.
Panels constructed in accordance with this disclosure have many benefits including exhibiting a light weight and a high strength for a given cross section, especially in view of prior art panels. The current inventive panels also include an option for the addition of strengthening ribs and/or edges to the design. Many surface finishes are possible including, but not limited to leather, laminate, vinyl, spray polyurethane, wood grain, texture and color variances, such as the use of various paints. Additionally various patterns and/or designs can be incorporated into the skins 24 and 26 . These variances can be realized through the type of skin 24 and 26 that is bonded in with the polyurethane layers 20 and 22 around the fiber layers 16 and 18 and a core 12 . Additionally an ultraviolet protective coating can be added if desired. Panels so constructed are also waterproof and have an increased durability for a wide range of uses.
One example of an item in which an inventive panel can be used is in the production of a portable floor. The portable floor 30 includes a plurality of floor panels 32 that include the core 12 , fiber layer 16 and 18 , polyurethane layers 20 and 22 , and skins 22 and 26 as previously discussed. Additionally, each panel includes a frame 34 surrounding the core 12 . The frame 34 preferably includes two (2) female sides 36 and two (2) male sides 38 . The female side 36 includes a lock engaging section 41 , and a channel 42 having a channel length 44 substantially equal to the core length 13 . The female side 36 is extruded such that it can directly engage the protrusion 46 . The male side 38 includes the protrusion 46 shaped to engage the channel 42 and a locking element 48 . The protrusion 46 has a protrusion length 50 substantially equal to the channel length 44 .
In a preferred embodiment the frame is composed of metal, such as aluminum, but can also be constructed of polymers. The protrusion 46 of one of the panels 32 is positioned to engage the channel 42 of an adjacent panel 32 to restrict movement of the panels in relation to one another. The engagement between the protrusion 46 and channel 42 preferably restricts both rotational and vertical movement of the panels in relation to one another. This can best be illustrated by FIG. 7 and FIGS. 2-3 showing engaged and disengaged embodiments of the male and female sides 36 and 38 of the frame 34 .
The frame 34 is designed with panel gaps 35 spaced to accept the core. The fiber layers, polyurethane layers and skins are all placed over the frame on the external surfaces 52 and 54 to increase the bonding and engagement between the frame pieces 34 . The external surfaces opposite 52 and 54 also get a fiber layer, polyurethane, and a skin.
The locking element 48 preferably includes a rotatable hook 56 that engages the extrusion of the female side or part 36 . Fasteners such as screws 58 can hold in the hook or lock 56 . This hook further facilitates the engagement between adjacent panels 32 during on-site assembly of the portable floor 30 and their disengagement upon disassembly of the floor after use. To engage the extrusion the hook 56 is rotated, for example using a known device such as an Allen wrench, inserted into hole 57 . Correspondingly, the female side 36 includes engaging aperture 41 into which the locking element 48 engages to secure adjacent panels 32 .
The floor panels 32 can also be constructed to include an alignment/lateral movement suppression system. The system comprises a gap in the protrusion 46 where the locking element 56 is located. This gap is used as a guide to mate to two pegs 62 , which can be cap head screws, located in the female side 36 . As such, corresponding floor panels 32 are aligned to establish a portable floor 30 that will be secure.
The extrusion incorporates at least one tooth 31 running the length of the extrusion on both sides of the channel 35 . This tooth 31 is compressed so as to bite into the core to secure the frame to the core.
Another example of a device incorporating one of the current inventive panels is a table 64 . The table 64 includes support legs 66 and a planar surface 68 attached to the support legs 66 . The planar surface 68 includes one of the panels 10 and a top exterior skin 70 and bottom exterior skin 72 . The top skin 70 and bottom skin 72 can be specifically designed for use as a table and can include corresponding edges 74 and 76 that engage and can be sealed together.
The table 64 can also include support structures 78 that are substantially equal to the core length 13 . The support structures 78 can provide additional rigidity to the table 64 . Additional support structures 80 can be positioned in the core 12 between the polyurethane layers 20 and 22 . These supports can be used to attach the hardware from the legs 66 to the planar surface 68 .
The bottom skin 72 can have recessed areas 73 positioned to accept the support structure 78 . This can also provide a handle area by which to carry the tables 64 . The table 64 can be made in both circular and polygonal shapes, such as rectangular, square and the like. Alternately, the legs 66 can be attached to the planar surface 68 or table top 68 by metal inserts that are integral to the bottom skin 72 .
Thus, although there have been described particular embodiments of the present invention of a new and useful NEW PORTABLE PANEL CONSTRUCTION AND METHOD FOR MAKING THE SAME, 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.
|
Disclosed herein is a portable panel having numerous favorable characteristics. The panel comprises a core having a length, a width, a first side and a second side. A first fiber layer is attached to the first side while a second fiber layer is attached to the second side. A first polyurethane layer is impregnated in the first fiber layer while a second polyurethane layer is impregnated into the second fiber layer. A first skin is attached to the first polyurethane layer while a second skin is attached to the second polyurethane layer. The panel can be used in the manufacture of tables, flooring, risers, stages, bleachers, and the like.
| 8
|
TECHNICAL FIELD
The disclosure relates to transmission clutches and, more particularly, to a passive clutch cooling system to reduce drag loss between the interleaved friction discs and the clutch plates of a rotating clutch.
BACKGROUND
Rotational clutches are frequently used as one of the mechanisms for engaging or disengaging the various gear components of a transmission in order to establish different gear ratios between an input member and an output member. A conventional rotational clutch assembly typically includes a set of clutch plates and a set of friction discs, sometimes referred to as a clutch pack, interleaved between one another in a clutch housing. When the clutch assembly is disengaged, the clutch plates and friction discs normally turn past one another without contact. However, when the corresponding components of a particular clutch, i.e., a drive member and a driven member, are to be engaged during a particular gear range, for example, a hydraulically actuated or spring-loaded piston forces the clutch plates and friction discs together. Friction surfaces on the clutch plates and the friction discs interact until the drive member and the driven member of the clutch assembly rotate in unison without slip.
In operation, a great deal of thermal energy is generated during the engagement and disengagement of the clutch plates and the friction discs, as well as during the period of full engagement, when the kinetic energy generated by the engaged clutch pack is also translated into a large amount of thermal energy. This thermal energy must be dissipated to prevent damage to the various components of the clutch assembly, particularly the frictional surfaces of the clutch plates and the friction discs. A continuous supply of a coolant, such as transmission fluid, is typically supplied to the clutch housing to serve this purpose. In a rotational clutch assembly, the transmission fluid may be supplied to an inside diameter portion of the engaged clutch plates and the friction discs and allowed to flow by centrifugal force across the plate surfaces to an outside diameter portion. The hot transmission fluid is then directed away from the clutch assembly to pass through a heat exchange process for transfer and release of the thermal energy absorbed into the transmission fluid.
When the rotational clutch assembly is not engaged, the clutch plates and the friction discs simply rotate past one another without contact. During this period of disengagement, the amount of thermal energy that must be dissipated is minimal. Furthermore, simply maintaining a continuous flow of transmission fluid to the clutch pack during disengagement may also result in significant inefficiencies. For example, depending on the relative speed of the rotating drive member with respect to the disengaged, driven member, drag losses may be generated as a result of shear experienced by the transmission fluid between the clutch plates and the friction discs. The shear increases proportionally with the amount of transmission fluid provided to the clutch pack during disengagement. Thus, particularly in gears where the relative rotational speed differential between the clutch plates and the friction discs is highest, it is desirable to limit the flow of coolant to the clutch pack.
Various clutch cooling systems have been proposed to address controlling the flow of coolant to the clutch pack during engagement and disengagement. For example, U.S. Pat. No. 5,988,335 describes actively controlling the flow to the clutch with a diverter valve and a sensor arrangement to sense the gear ratio of the transmission and divert flow from the clutch assembly in response to the transmission being in a selected gear ratio. U.S. Pat. No. 6,244,407 proposes a more passive system that does not rely on a sensor actuated valve. Rather, an outer ring is mounted onto the piston used to actuate engagement of the clutch pack. The outer ring has an orifice provided therein for allowing a flow of coolant therethrough. The outer ring is movable between a first position wherein the orifice is closed and the drive and driven members are disconnected and a second position where the orifice is open to allow the flow of pressurized fluid through the orifice to the clutch pack when dictated by movement of the piston to engage the clutch plates and the friction discs. Other types of “slider valve” arrangements are common in the industry, wherein the piston moves the slider valve in a direction to uncover an orifice for increasing coolant flow to the clutch pack during engagement. Typically, a spring, for example, may be employed to close the slider valve over the orifice when the clutch disengages.
As described above, conventional clutch cooling systems can often be complex and/or require the addition of various components to provide a variable flow of coolant to the clutch pack. The increased complexity of these designs may add to the cost of manufacture, assembly, and maintenance of the transmission and creates additional opportunities for failure during operation. As such, a clutch cooling system is needed that eliminates the requirement for additional components while taking advantage of the natural operational characteristics of rotational clutch assemblies.
SUMMARY
The foregoing needs are met, to a great extent, by aspects of the present disclosure, wherein a transmission clutch cooling system includes a drive member including a drive hub situated about an axis of rotation, a driven member including a clutch hub concentrically situated about the axis of rotation, wherein the clutch hub includes a hub deck having a plurality of bores therethrough, an inner annulus extending axially from the hub deck, and an outer annulus extending axially from the hub deck, the outer annulus including a plurality of radial orifices therethrough and a lip flange extending from a distal end towards the inner annulus. A clutch housing is defined between the drive hub and the clutch hub, and a clutch assembly is housed in the clutch housing that includes a plurality of clutch plates secured to the drive hub to rotate with the drive member, a plurality of friction plates secured to the driven member to rotate with the clutch hub, and a piston assembly for engaging or disengaging the plurality of friction plates against the plurality of clutch plates to cause or release integrated rotation of the drive member and the driven member.
In accordance with other aspects of the present disclosure, a clutch hub includes a hub deck having a plurality of bores therethrough, an inner annulus extending axially from the hub deck, and an outer annulus extending axially from the hub deck, the outer annulus including a plurality of orifices therethrough and a lip flange extending from a distal end towards the inner annulus.
In accordance with yet other aspects of the present disclosure, a method of cooling a rotational clutch includes supplying a flow of coolant to an annular clutch hub having axial bores and radial holes, the radial holes being in fluid communication with a clutch pack, increasing the flow of coolant to the clutch pack through the radial holes during engagement of the clutch pack, and diverting a portion of the flow away from the clutch pack through the axial bores when the clutch pack is disengaged.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of a machine including a multi speed transmission, in accordance with aspects of the present disclosure;
FIG. 2 is a schematic illustration of a transmission, in accordance with aspects of the present disclosure;
FIG. 3 is a partial cross-sectional side view of a clutch cooling system, in accordance with aspects of the present disclosure;
FIG. 4 is a chart illustrating rotational relative speed of a drive member and a driven member for a given set of gear ratios, in accordance with aspects of the present disclosure;
FIG. 5 is a bar graph illustrating estimated power loss in a clutch assembly for a given engine speed over a range of gears when transmission fluid flow to the clutch assembly is not restricted, in accordance with aspects of the present disclosure;
FIG. 6 is an axial view of a clutch hub component of a clutch cooling system, in accordance with aspects of the present disclosure;
FIG. 7 is a partial cross-sectional side view illustrates aspects of a clutch cooling system, in accordance with aspects of the present disclosure; and
FIG. 8 is a partial cross-sectional side view illustrating aspects of a clutch cooling system, in accordance with aspects of the present disclosure.
DETAILED DESCRIPTION
The disclosure will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout.
Referring to FIG. 1 , a multi-speed transmission 10 may be included in a machine 12 . An input member 14 may connect the transmission 10 to a prime mover 16 by a torque converter 18 , and an output member 20 may connect the transmission 10 to one or more traction devices 22 . Although the machine 12 is shown as a truck, it may be any type of machine that may benefit from the use of a multi speed transmission. The prime mover 16 may be of any type that outputs power in a form usable by the multi-speed transmission 10 . For example, the prime mover 16 may be an internal combustion engine (such as a diesel engine, a gasoline engine, a turbine engine or a natural gas engine), an electric motor, or other device capable of generating a power output. The traction devices 22 may be any type of traction devices, such as, for example, wheels as shown in FIG. 1 , tracks, belts, or any combinations thereof.
As shown in the schematic illustration of FIG. 2 , the multi-speed transmission 10 may be a planetary transmission having a series of annular components rotatably supported and aligned about a rotational axis 24 , the schematic illustrating aspects of the transmission on one side of the axis 24 only. Torque may be supplied to the input member 14 by the prime mover 16 through the torque converter 18 , for example. At least one, and often a plurality of gear sets, may be interconnected between the input member 14 and the output member 20 . As shown in FIG. 2 , the multi-speed transmission 10 may have four interconnected planetary gear sets, 30 , 32 , 34 and 36 rotatably supported concentrically along the rotational axis 24 in a transmission casing 28 . Each planetary gear set 30 , 32 , 34 and 36 includes at least one sun gear, at least one planetary carrier, and at least one ring gear.
The transmission 10 may also include a number of control elements operatively coupled to the planetary gear sets 30 , 32 , 34 and 36 . As used herein, the term “control element” includes clutches (which are alternatively referred to in the industry as rotational clutches), brakes (which are alternatively referred to in the industry as stationary clutches), synchronizers (including dog and other types of synchronizing clutches) or other torque control components that may conventionally be used in a transmission. As shown in FIG. 2 , the transmission 10 may include three rotational clutch assemblies 40 , 42 , and 44 and three brake assemblies 50 , 52 , and 54 . The rotational clutch assemblies 40 , 42 , and 44 and brake assemblies 50 , 52 , and 54 cooperate with and may selectively couple particular elements of the planetary gear sets to establish, for example, a set of ten forward gear ratios and one reverse gear ratio between the input member 14 and the output member 20 .
FIG. 3 illustrates a rotational clutch assembly 100 in accordance with aspects of the present disclosure. The rotational clutch assembly 100 may be used in the transmission 10 , for example, as one or more of the rotational clutch assemblies 40 , 42 , and 44 . The clutch assembly 100 may include a drive member, generally indicated at 102 , and a driven member 104 , generally indicated at 104 , which rotate about a common axis. A clutch housing 106 is generally defined between the drive member 102 and the driven member 104 and is formed to house a clutch pack, generally indicated at 110 , that is engaged or disengaged through actuation of a piston 112 , such as through hydraulic actuation or spring force actuation. A balance piston assembly 114 may be included and housed in the clutch housing 106 along with the piston 112 in order to introduce reverse pressure on the low pressure side of the piston 112 to counteract the large thrust generated by the hydraulic pressure fluid on the high pressure side of the piston and prevent the piston from engaging the clutch at high rotational speeds.
The annular clutch pack 110 may be composed of annular clutch plates 116 that are splined to and extend inward from a drive hub portion 118 of the drive member 102 and annular friction discs 120 that are splined to and extend outward from a clutch hub 122 of the driven member 104 . The clutch plates 116 and friction discs 120 are interleaved as shown in FIG. 3 . In accordance with aspects of the present disclosure, when the clutch assembly 100 is in a disengaged position, the drive member 102 maintains a certain rotational speed based on an input speed of the input member 14 of the transmission 10 and the driven member 104 is disengaged and not rotating or rotating at a different relative speed. When the clutch assembly 100 is in the disengaged position, the clutch plates 116 rotate freely past the friction discs 120 in a non-contacting manner. However, when the clutch pack 110 is to be placed into an engaged position during a particular gear change, for example, when moving from the fifth gear to the sixth gear in the transmission 10 described previously, pressurized hydraulic fluid is introduced into a pressure chamber 124 to produce axial movement of the piston 112 . In turn, actuation of the piston 112 forces a frictional engagement of the clutch plates 116 with the friction discs 120 to reduce or eliminate relative rotation between the clutch plates 116 and the friction discs 120 .
As discussed above, during engagement of the clutch pack 110 , the relative rotational speed of the drive member 102 and the driven member 104 may be synchronized. The frictional energy and kinetic energy generated by the engaged clutch pack 110 translates into a large amount of thermal energy that must be dissipated to reduce or eliminate wear or damage that may occur to the clutch plates 116 and the friction discs 120 . To facilitate cooling during this time, a continuous flow of coolant, such as automatic transmission fluid, may be provided to the clutch hub 122 .
In accordance with aspect of the present disclosure, the clutch hub 122 may be formed with an inner annulus 126 connected to an outer annulus 128 by a hub deck 130 . The inner annulus 126 and the outer annulus 128 extend from the hub deck 130 in a direction toward the piston 112 and cooperate with the shape of the hub deck 130 to form an interior space 132 . The outer annulus 128 may be provided with a series of radial bores 134 . The radial bores 134 provide fluid communication from the interior space 132 to the clutch pack 110 for a fluid to flow through the outer annulus 128 toward the clutch pack 110 . Thus, when the clutch pack 110 is engaged to cause rotation of the clutch hub 122 at the same speed as the drive member 102 , by way of centrifugal action, the transmission fluid is forced through the radial bores 134 and into the clutch pack 110 at an accelerated rate versus when the clutch pack is disengaged and motion of the transmission fluid into the clutch pack 110 is primarily by force of gravity. The radial bores 134 are sized to provide a maximum flow of coolant during a particular period of clutch engagement, for example, to provide sufficient cooling during engagement and disengagement between particular gears when thermal energy generation is greatest. Yet the radial bores 134 are also sized to restrict a majority of the coolant flow to the clutch pack 110 during a period of disengagement when centrifugal force is reduced or nonexistent.
As explained above, the issue of providing sufficient cooling during engagement of the clutch assembly 100 can also lead to inefficiencies due to transmission fluid sheer during disengagement. FIG. 4 is a chart illustrating the relative speed difference between the constantly rotating drive member 102 , including the clutch plates 116 , and the driven member 104 , including the friction discs 120 , for a typical range of gears in a multi-speed transmission 10 . The relative speed line indicates that the relative rotational speed between the driven member and the drive member is greatest in forward gears one ( 1 F) and two ( 2 F). In forward gears three ( 3 F) through five ( 5 F), the driven member 104 is controlled to increase speed relative to the drive member 102 until the clutch assembly 100 is engaged during a shift from gear 5 F to forward gear six ( 6 F) where it remains engaged through forward gear ten ( 10 F). As illustrated by the chart, because the rotational speeds of the clutch plates 116 and the friction discs 120 are synchronized in gears 6 F- 10 F, the difference in relative speed is zero. When the transmission is controlled to provide the reverse gear (R), the relative speed difference between the clutch plates 116 and the friction discs is again at its highest.
FIG. 5 is provided to illustrate the estimated power loss experienced as a result of the shearing of lubrication fluid in the clutch pack 110 if lubrication fluid is not diverted in accordance with aspects of the present disclosure. As shown by the chart, if the input speed of the transmission is maintained at a steady speed of, for example, 1500 rpm, the power losses are clearly highest in gears 1 F, 2 F and Reverse when the relative speed difference between the drive member 102 and the driven member 104 are highest, as illustrated in FIG. 4 . Conversely, the power loss decreases successively in gears 3 F- 5 F as the relative speed difference decreases until the power losses due to shearing are essentially zero in gears 6 F- 10 F because of the concurrent rotation of the clutch plates 116 and the friction discs 120 with the clutch assembly 100 engaged. It should be noted that the particular power numbers shown in FIG. 5 may vary significantly for different transmissions depending on a number of factors, including the number and diameter of the clutch plates 116 and/or the friction discs 120 , for example. However, the relative amounts of power loss experienced across the gear range, e.g., power loss being highest in gears 1 F, 2 F, and 1 R, remains substantially as shown in FIG. 5 .
As shown in FIGS. 6 and 7 , a cooling system in accordance with aspects of the present invention may include a series of axial facing bores 136 provided in the hub deck 130 of the clutch hub 122 . The axial facing bores 136 may be spaced peripherally toward an outside diameter of the hub deck 130 and sized to permit a substantial quantity of the flowing coolant to escape the interior space 132 , primarily during a period of disengagement of the clutch assembly. Placement of the axial facing bores 136 near the outside diameter of the hub deck 130 also allows the clutch hub 122 to retain and direct a significant quantity of the flowing coolant toward and through the radial bores 134 during the period of engagement to lubricate and cool the clutch pack 110 . Lengthening the run of fluid flow allows development of a significant amount of centrifugal force to act on the fluid as it flows toward the radial bores 134 .
Referring back to FIG. 3 , a lip flange 140 may be provided toward a distal end of the outer annulus 128 to extend a predetermined distance toward the inner annulus 126 . The axial bores 136 may be displaced radially inward from an inner diameter of the outer annulus 128 to create a step 138 . The lip flange 140 may be formed to extend toward the inner annulus 126 a distance greater than the radial dimension of the step 138 . Accordingly, a trough area 142 is formed in the outer annulus 128 between the step 138 and the lip flange 140 to maintain a small amount of coolant in the trough area 142 when the clutch hub 122 is not rotating or is rotating slowly. Thus, even during a period of clutch disengagement, although a majority of the coolant fluid flow is able to drain out of the interior space 132 through the axial bores 136 , the radial bores 134 may be appropriately dimensioned to allow an appropriate amount of coolant to drain by force of gravity from the trough area 142 into the clutch pack 110 . Thus, a minimal amount of fluid flow may be established during disengagement of the clutch assembly 100 , enough of a fluid flow from the interior space 132 to the clutch pack 110 to maintain viability and efficiency of the moving components without introducing the inefficiencies of shear caused by excessive fluid flow during the period of disengagement. As shown in FIG. 3 , through-holes 139 , for example, may be provided in a housing component of the drive member for further routing of the fluid flow away from the clutch assembly.
FIGS. 6 and 7 illustrate that the axial bores 136 may be arcuately spaced at equal angles θ around the perimeter of the hub deck 130 such that at least a portion of one or more of the axial bores 136 will always be below the fluid level in the trough area 142 formed in the outer annulus 128 of the clutch hub 122 when the clutch hub 122 is not rotating, i.e., when the clutch pack 110 is disengaged. Accordingly, when the clutch hub 122 is stopped and the relative speed between the clutch plates 116 and the friction discs 120 is highest, such as in gears 1 F, 2 F and R, for example, the larger axial bores 136 are configured to drain away a majority of the transmission fluid and the smaller radial bores 134 are configured to allow only a select quantity of transmission fluid into the clutch pack 110 . Similarly, when the clutch hub 122 of the driven member 104 begins to rotate faster relative to the drive hub portion 118 of the drive member 102 , such as in gears 3 F- 5 F, or when the the clutch assembly 100 is engaged in gears 6 F- 10 F, centrifugal force will once again operate to pump the transmission fluid through the outer annulus 128 and into the clutch pack 110 .
In accordance with yet other aspects of the present disclosure, a seal (not shown) may be provided to close a gap 146 that may exist between the lip flange 140 and components of the driven member 104 , such as the balance piston 114 (see FIG. 3 ), if it is determined that excess amounts of transmission fluid are spilling over the lip flange 140 into the clutch pack 110 during the disengagement period of the clutch assembly 100 .
FIG. 8 illustrates a rotational clutch assembly 200 in accordance with yet other aspects of the present disclosure. The rotational clutch assembly 200 may be used in the transmission 10 , for example, as one or more of the rotational clutch assemblies 40 , 42 , and 44 . The clutch assembly 200 may include a drive member, generally indicated at 202 , and a driven member, generally indicated at 204 , which rotate about a common axis. A clutch housing 206 is generally defined between the drive member 202 and the driven member 204 and is formed to house a clutch pack, generally indicated at 210 , that is engaged or disengaged through actuation of a piston 212 , such as through hydraulic actuation or spring force actuation. A balance piston assembly 214 may be included and housed in the clutch housing 206 along with the piston 212 in order to introduce reverse pressure on the low pressure side of the piston 212 to counteract the large thrust generated by the hydraulic pressure fluid on the high pressure side of the piston and prevent the piston from engaging the clutch at high rotational speeds.
The annular clutch pack 210 may be composed of annular clutch plates 216 that are splined to and extend inward from a drive hub portion 218 of the drive member 202 and annular friction discs 220 that are splined to and extend outward from a clutch hub 222 of the driven member 204 . The clutch plates 216 and friction discs 220 are interleaved as shown in FIG. 8 . In accordance with aspects of the present disclosure, when the clutch assembly 200 is in a disengaged position, the drive member 202 maintains a certain rotational speed based on an input speed of an input member of the transmission 10 and the driven member 204 is disengaged and not rotating or rotating at a slower relative speed. When the clutch assembly 200 is in the disengaged position, the clutch plates 216 rotate freely past the friction discs 220 in a non-contacting manner. However, when the clutch pack 210 is to be placed into an engaged position during a particular gear change, for example, when moving from the fifth gear to the sixth gear in the transmission 10 described previously, pressurized hydraulic fluid is introduced into a pressure chamber 224 to produce axial movement of the piston 212 . In turn, actuation of the piston 212 forces a frictional engagement of the clutch plates 216 with the friction discs 220 to reduce or eliminate relative rotation between the clutch plates 216 and the friction discs 220 .
As discussed above, during engagement of the clutch pack 210 , the relative rotational speed of the drive member 202 and the driven member 204 may be synchronized. To facilitate cooling during transition to and from an engaged state, and to reduce the transferred kinetic energy while the members are engaged, a continuous flow of coolant, such as automatic transmission fluid, may be provided to the clutch hub 222 . In accordance with aspects of the present disclosure, the clutch hub 222 may be formed with an inner annulus 226 connected to an outer annulus 228 by a hub deck 230 . The inner annulus 226 and the outer annulus 228 extend from the deck 230 in a direction toward the piston 212 and cooperate to form an interior space 232 . The outer annulus 228 may be provided with a series of radial bores 234 that provide fluid communication from the interior space 232 to the clutch pack 210 for a fluid to flow through the outer annulus 228 toward the clutch pack 210 .
A slinger plate 250 may be mounted to the hub deck 230 and configured to divide the interior space 232 into an upper space 233 and a lower space 235 while providing a trough 242 for collecting transmission fluid pumped into the interior space 232 . A series of axial facing bores 236 may be provided in the hub deck 230 of the clutch hub 222 . The axial facing bores 236 are spaced peripherally a radial distance from the center of the hub deck 230 and just above where the slinger plate 250 divides the interior space 232 . The axial bores 236 are sized to permit a substantial quantity of the flowing coolant to escape the upper space 233 , primarily during a period of disengagement of the clutch assembly 200 .
The slinger plate 250 is also provided with a series of radially situated slinger bores 244 at the bottom of the trough 242 . The slinger bores 244 provide fluid communication from the upper space 233 to the lower space 235 for the transmission fluid to flow therethrough. Thus, when the clutch pack 210 is engaged to cause rotation of the clutch hub 222 at the same speed as the drive member 202 , or during a period when rotation of the driven member 204 is increased relative to the rotation of the drive member 202 , such as in gears 3 F- 10 F, by way of centrifugal action transmission fluid is forced through the slinger bores 244 and into the lower space 235 . Once in the lower space 235 , the transmission fluid may continue under centrifugal force to flow through the radial bores 234 into the clutch pack 210 . The size of the slinger bores 244 and the radial bores 234 are determined in order to restrict a majority of the coolant flow to the lower space 235 and thus the clutch pack 210 during a period of disengagement, when most of the transmission fluid is intended to drain from the trough 242 by way of the axial bores 236 .
The axial bores 236 may be arcuately spaced at equal angles θ around the perimeter of the hub deck 230 such that at least a portion of one or more of the axial bores 236 will always be below the fluid level in the trough area 242 when the clutch hub 222 is not rotating, i.e., when the clutch pack 210 is disengaged. Accordingly, when the clutch hub 222 is stopped and the relative speed between the clutch plates 216 and the friction discs 220 is highest, such as in gears 1 F, 2 F, or R, the larger axial bores 236 may drain away a majority of the coolant before the coolant drains through the slinger bores 244 and the radial bores 234 into the clutch pack 210 . Once the clutch assembly 200 is engaged and/or the clutch hub 222 starts to rotate, the slinger bores 244 and the radial bores 234 will work again to pump the transmission fluid into the clutch pack 210 to provide adequate removal of the thermal heat generated therein.
Various aspects of systems and methods for cooling a clutch assembly may be illustrated by describing components that are connected, attached, and/or joined together. As used herein, the terms “connected”, “attached”, and/or “joined” are used to indicate either a direct connection between two components or, where appropriate, an indirect connection to one another through intervening or intermediate components. In contrast, if a component is referred to as being “directly coupled”, “directly attached”, and/or “directly joined” to another component, there are no intervening elements present.
Industrial Applicability
The disclosure includes a clutch cooling system and methods for cooling a clutch that include passively controlling the flow of coolant to a clutch pack in the clutch. The cooling system efficiently transfers thermal energy generated by the engagement and disengagement of the clutch pack while reducing drag losses of the clutch assembly when the clutch is disengaged. The clutch cooling system is disclosed for use in transmissions on vehicles, including heavy haul trucks or ground moving equipment, for example, but may be used in any machine that uses clutches for the engagement and disengagement of component members.
In a rotational clutch having a drive member and a driven member, the clutch cooling system employs a unitary clutch hub attached to the driven member that has axial bores and radial holes, the radial holes being in fluid communication with a clutch pack and the axial bores providing an outlet from the clutch assembly. Through placement and sizing of the axial bores and the radial holes, passive cooling control depends simply on the rotational speed of the clutch hub by increasing a flow of coolant to the clutch pack through the radial holes during engagement of the clutch pack, when the clutch hub is rotating, while diverting a larger portion of the flow away from the clutch pack via the axial bores when the clutch pack is disengaged, when the clutch hub is not rotating or rotating at a much slower speed.
The many features and advantages of the disclosure are apparent from the detailed specification, and, thus, it is intended by the appended claims to cover all such features and advantages of the disclosure which fall within the true spirit and scope of the disclosure. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the disclosure to the exact construction and operation illustrated and described, and, accordingly, all suitable modifications and equivalents may be resorted to that fall within the scope of the disclosure.
|
A transmission clutch cooling system includes a clutch housing defined between a drive hub of a drive member and a clutch hub of a driven member and a clutch assembly housed in the clutch housing. The clutch hub includes a hub deck having a plurality of bores therethrough, an inner annulus extending axially from the hub deck, and an outer annulus extending axially from the hub deck, the outer annulus including a plurality of radial orifices therethrough and a lip flange extending from a distal end towards the inner annulus. The clutch assembly includes a plurality of clutch plates secured to the drive hub and a plurality of friction plates secured to the driven member. A piston assembly is provided for engaging or disengaging the plurality of friction plates against the plurality of clutch plates to cause or release integrated rotation of the drive member and the driven member.
| 5
|
BACKGROUND
[0001] 1. Field
[0002] This disclosure relates to treatment of wastewaters containing organic matter, phosphorus and nitrogen. In particular, the disclosure relates to utilizing sulphur compounds as the electron carrier for biological nutrient removal of wastewater treatment
[0003] 2. Background
[0004] Since the discovery of activated sludge process and the introduction of the biological nutrient removal processes, the biological Phosphorus (P), Nitrogen (N) and Carbon (C) removal processes has remained the same, i.e., with electron flow from carbon to oxygen through heterotrophic carbon oxidation, as shown in FIG. 1 .
[0005] The details of this biological P, N and C removal process are as follows:
Reactor 1: P is released and organic carbon is taken up and stored as poly-hydroxyalkanoates (PHAs) by the Poly-phosphate Accumulating Organisms (PAOs) when no oxygen or nitrate is present. Reactor 2: When nitrate is present, the stored organic carbon is oxidized to CO 2 through heterotrophic denitrification. Nitrate is reduced to N 2 . Electron flows from organic carbon to nitrate with simultaneous P-uptake by the PAOs. Reactor 3: Electron flows from ammonia to oxygen with nitrate formed through autotrophic nitrification which is recycled back to Reactor 2.
[0009] If nitrogen removal is not necessary, the biological processes can be simplified as FIG. 2 . The biological processes are as follows:
Reactor 1: P is released and organic carbon is taken up and stored as PHAs by the PAOs when no oxygen is present. Reactor 2: When oxygen is present, the stored organic carbon is oxidized to CO 2 through heterotrophic carbon oxidation. Electron flows from organic carbon to oxygen with simultaneous P-uptake by the PAOs.
[0012] As the heterotrophic carbon oxidation and heterotrophic denitrification process has a very high sludge yield factor, depending on the sludge age, about 40-50% of the organic carbon in the sewage will be converted to CO 2 while the rest converted to sewage sludge. The disposal of excess sludge, which often involves sludge digestion, dewatering and incineration, is not only costly, but also unwelcome by neighbours to the facility.
[0013] Since the introduction of biological phosphorus (P) removal process in 1970s, the process has relied on the electron flow from organic carbon to oxygen via an integrated P-uptake and release cycle. As the process has a high sludge yield, excess sludge disposal is required.
[0014] Sulfate Reduction Autotrophic Denitrification and Nitrification Integrated SANI Process
[0015] Making use of the sulfate ion available in the saline sewage of Hong Kong, where seawater is used for toilet flushing, the Hong Kong University of Science and Technology developed the novel Sulfate reduction Autotrophic denitrification and Nitrification Integrated (SANI) process (Lau et al., 2006; Lu et al., 2009; Wang et al., 2009) as shown in FIG. 3 . In the SANI process, sulfate originating from seawater is used to oxidize organic carbon to CO 2 while sulfate is reduced to dissolved sulfide by the sulfate reduction bacteria in the first reactor. On the other hand, nitrogen present in ammonia is oxidized by oxygen to nitrate in the third reactor by the autotrophic nitrifiers. The nitrate formed is then recycled to the second reactor to react with the sulfide ion to convert into nitrogen gas by the autotrophic denitrifiers while sulfide will be converted back to sulphate ion. An example of the SANI process is described in PCT/CN2011/002019 filed 2 Dec. 2011, published as WO 2012/071793 A1, and as correspond application US2013/0256223.
[0016] Each liter of seawater contains about 2.7 grams of sulphate. When used with a seawater flushing system, the sulphates in seawater can be used to oxidize the organic carbon pollutants forming sulphide; while the sulphide formed can then be used to reduce nitrate to nitrogen gas through autotrophic denitrification, which can help sludge reduction. The SANI process uses sulphate-reducing bacteria to oxide and eliminate pollutants in the seawater-mixed sludge. It is noted, however, that the sulphate cannot directly reduce sludge; however, it is used as a oxidizing and reducing agent to remove organic carbon and nitrate, which in turn results in sludge reduction.
[0017] The three key biological chemical processes all produce minimal sludge as shown in the following equations:
[0018] (1) Heterotrophic Sulfate Reduction:
[0000] 127.8 gCOD+192 gSO 4 2− +55.8gH 2 O→68 gH 2 S+2.4 gSludge+244 gHCO 3 −
[0019] (2) Sulfide Oxidation and Autotrophic Denitrification:
[0000] 124gNO 3 − +7.32 gHCO 3 − +44.54 gH 2 S→28 gN 2 +125.76 gSO 4 2− +2.66 gSludge
[0020] (3) Autotrophic Nitrification:
[0000] 18 gNH 4 + +1.32 gCO 2 +62.4 gO 2 →0.94 gSludge+62 gNO 3 − +2 gH + +17.64 gH 2 O
[0021] Limited-Oxygen Sulphur Cycle-Associated EBPR (LOS-EBPR) Process
[0022] In view of its significant environmental and financial benefits to minimize sludge production by the SANI process, research has been conducted to extend the SANI process for P-removal. The success of this biological P-removal SANI process lies with the development of the P uptake and release in the sulphur cycle. Although the oxygen and nitrate induced P-uptake and release phenomenon has been fully studied and understood, the proposed sulphur cycle involved P-uptake and release has not been extensively tested. The phenomenon is described in Sulfate Reducing Bacteria (SRB) with the PAOs.
SUMMARY
[0023] Sewage treatment is performed using a first cycle which uses sulphur comprising at least one of sulphur and sulphur compounds to transfer electrons from organic carbon to oxygen, nitrate and nitrite. The sulphur is also used to convert phosphorus containing compounds to solid material for retention in sewage sludge. The sulphur is then used to perform denitrification of nitrogen compounds. Oxygen is used to oxidize any ammonia present to nitrate and/or nitrite.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a schematic diagram showing an example of a conventional biological process of P, N and C removal.
[0025] FIG. 2 is a schematic diagram showing an example of a conventional biological process of P and C removal.
[0026] FIG. 3 is a schematic diagram showing an example of a biological process using the SANI technique for N and C removal.
[0027] FIG. 4 is a schematic diagram showing an example of sulphur cycle-associated denitrifying enhanced biological phosphorus removal (SD-EBPR) process for biological nutrient removal.
[0028] FIG. 5 is a schematic block diagram showing a conceptual design for the SD-EBPR Process.
[0029] FIG. 6 is a schematic block diagram showing several sequencing batch reactors (SBR) operating in parallel to achieve a smooth operation of the SD-EBPR Process.
[0030] FIG. 7 is a diagram showing key biological reactions in the oxidation of sulphur compounds.
[0031] FIG. 8 is a diagram showing the SD EBPR process with a sulfate cycle used in a lab study.
[0032] FIG. 9 is a diagram showing the SD-EBPR process in which synthetic sewage is employed in a lab-scale system.
DETAILED DESCRIPTION
Overview
[0033] By introducing the sulphur cycle into the carbon oxidation cycle, a Sulphur cycle-associated Denitrifying Enhanced Biological Phosphorus Removal (SD-EBPR) process is developed for biological nutrient removal (BNR) with minimal sludge production. FIG. 4 is a schematic diagram showing an example of the SD-EBPR technique for C, N and P removal. Sulphur compounds in various forms, such as sulfate (SO 4 2− ), sulfite (SO 3 2− ), thiosulfate (S 2 O 3 2− ), sulfide (S 2− ) and elemental sulphur) (5° (the key forms of sulphur present in wastewater) can be used as electron carrier to transfer electrons from organic carbon to oxygen through luxury P-uptake and release, anaerobic carbon uptake (PHAs storage), heterotrophic sulphur reduction (poly-S 2− /S 0 storage), and heterotrophic/autotrophic denitrification and autotrophic nitrification, by the sulphur cycle based Poly-phosphate Accumulating Organisms (PAOs, as a new type of process using PAOs, which is not found in the conventional carbon based EBPR process. This process can be described as a sulphur cycle based PAO process, which differs from processes in other biological wastewater treatment plant processes using PAOs.
[0034] In terms of operation, the feed and the reaction of an aerobic sequencing batch reactor (SBR) can be combined into a single step. Moreover, to enable a more efficient operation, it is also possible to use a combination of several similar or identical biological P-removal reactors and nitrification reactors operating in parallel in order to smooth out the operations. Through the SD-EBPR process, it is possible to achieve biological nutrient removal from wastewater while at the same time minimizes sewage sludge production.
[0035] The sulphur can be derived from any convenient source. In non-limiting examples, saline sea water provides the sulphur. The saline water is either provided as part of the wastewater, for example as a saline water flush system, or is added to the wastewater during treatment. The salinity is not essential, and is only one way to provide the sulfate and/or sulphite. The sulphur can also be provided from industrial effluent such as flue gas desulphurization units.
[0036] The SD-EBPR process is shown in FIG. 5 . In a test configuration, a biological P-removal reactor was integrated into the system using the SBR process (Reactor 1) and an attached growth nitrification reactor (Reactor 2) for SD EBPR, as shown in FIG. 5 . The biological processes involved are summarized as follows:
Reactor 1—Primary Feeding: Wastewater is added to Reactor 1—the sulphur cycle SBR; where necessary, alternative sulphur source can be added at the same time. Reactor 1—Anaerobic reaction: Poly-phosphate degradation and organic carbon uptake by microorganisms. Phosphate is released to the bulk liquid and PHAs is synthesized. Sulphur compound reduces to poly-S 2− /S 0 while part of the organic carbon oxidizes to CO 2 through heterotrophic sulphur reduction. Electron flows from organic carbon to the storage products (e.g., PHAs and poly-S 2− /S 0 ). A small amount of sulfide and thiosulfate is produced by anaerobic sulphate reduction. Reactor 1—Primary Settling and Decantation: the supernatant of the reactor after anaerobic reaction is pumped into Reactor 2, an aerobic attached growth reactor. Reactor 2—Nitrification: The organic nitrogen compounds and any ammonia which is present/produced are converted to nitrite (NO 2 − )/nitrate (NO 3 − ) through autotrophic nitrification. Electron flows from organic nitrogen compounds and ammonia to oxygen with nitrite/nitrate formed. Reactor 1—Secondary Feeding: Effluent from Reactor 2 is pumped back to Reactor 1. Reactor 1—Anoxic Reaction: Electron flows from the storage products (e.g., PHAs and poly-S 2− /S 0 ) to nitrite/nitrate. Poly-S 2− /S 0 oxidizes to sulfate through autotrophic denitrification and PHAs oxidizes to HCO 3 − through heterotrophic dentrification while nitrite/nitrate reduces to nitrogen gas. At the same time, luxury P uptake occurs. Reactor 1—Secondary Settling and Decantation: Settling is conducted and the supernatant is decanted as final effluent.
[0044] The depiction of FIG. 5 shows at temporal change in status. Reactor 1 is a single reactor; however the depiction gives the appearance of multiple reactors because it represents a change of status in terms of time. In viewing FIG. 5 , after feeding, the stirrer will start with P-release, and then decants. The effluent from Reactor 1 will then be pumped to Reactor 2. After that, the effluent from Reactor 2 can feed back to Reactor 1, the stirrer then starts with P-uptake, then decants as final effluent.
[0045] Under anoxic condition, there is nitrate (NO 3− ) and nitrite (NO 2− ). During the process bacteria will use up the oxygen from nitrate and convert the nitrate to nitrogen gas. In this phase, bacteria consume the phosphorus from the bulk liquid. This contrasts with anaerobic processed in that, under anaerobic conditions, there is no nitrate and nitrite, and instead bacteria will release phosphorus into the bulk liquid.
[0046] Depending on the design of the reactors, apart from activated sludge/SBR process, other types of reactor designs such as granular sludge bed, attached growth biofilters, membrane biological reactors, can be used for biological P-removal. Moreover, the SD-EBPR process can be operated in many forms, such as a combination of SBR in parallel operation to enable a continuous flow condition, as shown in FIG. 6 .
[0047] The minimum sulphur content is related to the concentration of organic material in the wastewater. A minimum ratio between the organics and sulphur contents used to completely process the wastewater would be 2 g COD/1 g SO 4− S or 1.5 g COD/g SO 3− S, where COD is the Chemical Oxygen Demand. This ratio may change if other sulphur compounds, e.g. thiosulfate, is used. It is also possible that lower ratios can be used, such as at least 1.5 g COD/g SO 4 −S, or 1 g COD/g SO 3 −S by weight, depending on the characteristics of the wastewater being treated.
[0048] Using Other Sulphur Compounds
[0049] The SD-EBPR process, apart from sulfate, may make use of other possible sulphur oxidation and reduction processes for accomplishing the heterotrophic sulphur reduction and autotrophic sulphur oxidation processes. The key biological processes involved in the autotrophic oxidation of sulphur compounds are shown in FIG. 7 . The reverse of these reactions, i.e., the reduction of the oxidized sulphur compounds, are conducted by the heterotrophic sulphur-reducing bacteria.
[0050] As compared to the conventional biological P-removal processes, the SD-EBPR process makes use of the sulphur compounds as electron carrier for the oxidation of organic carbon to carbon dioxide. As both the anaerobic sulphur-reduction and autotrophic sulphur-oxidation processes have very low sludge yield factor, the sludge production rate of the SD-EBPR process is much lower than conventional P-removal processes. It effectively minimizes the need for sludge wastage, handling and disposal requirements. This not only reduces a large amount of sewage treatment cost, but also reduces greenhouse gas emission.
[0051] Effectiveness of the SD-EBPR
[0052] As compared with conventional biological process, shown in FIG. 1 , the SD-EBPR process shown in FIG. 5 introduces a sulphur cycle by making use of the sulphur compounds as the electron carrier for the oxidation of organic carbon to CO 2 .
[0053] As compared with the SANI process, shown in FIG. 3 , the SD-EBPR process ( FIGS. 4 and 5 ) introduces a sulphur induced Phosphorus-uptake and release phenomenon to accomplish biological phosphorus removal, in addition to carbon and nitrogen removal.
EXAMPLE
SD-EBPR Process
[0054] A 140-day lab-scale study was completed using synthetic sewage, confirming that the SD-EBPR system, as shown in FIG. 8 , operates satisfactorily with simultaneous removal of COD, N and P, and with minimized biological sludge production. The configuration was the same as depicted in FIG. 4 , except that, since sulfate (SO 4 2− ) was used in the lab study, sulfate, the process differs from that depicted in FIG. 4 in that the processing of sulfite (SO 3 2− ) is absent.
[0055] Set Up of the SD-EBPR Lab-Scale System
[0056] FIG. 9 is a diagram showing the SD-EBPR process in which synthetic sewage is employed in a lab-scale system. The SD-EBPR lab-scale system was installed in an environment in which synthetic sewage was employed. Comprising of a sequencing batch reactor (Reactor 1) for sulphur cycle enhanced biological removal, and a sequencing batch reactor (Reactor 2) for autotrophic nitrification. The lab-scale system had been operated at stable conditions for about 100 days.
[0057] Reactor 1 was made of transparent PVC, having a total reactor volume of 5 L (4 L reaction volume and 1 L headspace). This reactor was tightly sealed and continuously operated in darkness, with mixing by a mechanical mixer, at 250 rpm. Reactor 2, packed with plastic media (specific area of 200 m 2 /m 3 ), had an effective liquid volume of 4 L. In addition, a 3.5 L tank was used to collect the nitrified effluent from Reactor 2, and then pumped into Reactor 1 at the initial of anoxic reaction phase.
[0058] Reactor 1 was operated continuously under an alternating anaerobic/anoxic condition. The cycle length of this SBR (Reactor 1) was 720 min in total. The cyclic operation of this anaerobic anoxic-SBR, comprised (i) feeding of 2 L synthetic sewage (in 10 min), (ii) anaerobic reaction phase (in 310 min), (iii) setting (30 min), (iv) decanting 3.5 L of liquid (i.e., primary discharge) into Reactor 2 (in 10 min), (v) feeding of 3.5 L nitrified effluent from the collecting tank into Reactor 1 (in 10 min), (vi) anoxic reaction phase (in 230 min), (vii) settling (in 110 min), and (viii) decanting 2 L of supernatant as the final effluent (in 10 min).
[0059] Reactor 2 was intermittently operated in every 12 hours. In each operation, the cycle length of this SBR (Reactor 2) was 6 hours in total. The cyclic operation of Reactor 2 comprised (i) feeding 3.5 L of partially treated effluent from Reactor 1 into Reactor 2 (in 10 min), (ii) aerobic condition for autotrophic nitrification (in 310 min), (iii) settling (in 30 min), and (iv) decanting 3.5 L supernatant into the collecting tank (in 10 min).
[0060] After the nitrified effluent of Reactor 2 was discharged into the collecting tank, Reactor 2 and collecting tank was put aside in the idling condition of 6 hours; the nitrified effluent in the collecting tank was used by step (v) of Reactor 1 after 6 hours.
Reactor 1 and Reactor 2 were seeded and inoculated, respectively, with anaerobic digester sludge (MLSS˜8,000 mg/L) and recycle activated sludge (MLSS˜4,000 mg/L) taken from a local secondary saline sewage treatment plant. The operating condition of the lab-scale system at stable condition after an acclimation period of about 40 days is shown in Table 1:
[0000]
TABLE 1
Operating condition of the SD-EBPR lab-scale system at stable operating condition.
Operating
Cycle No.
Cycle time
ORP
DO
T
SRT a
Mode
(per day)
(hours)
pH
(mV)
(mg/L)
(° C.)
Salinity
(d)
Reactor 1
Continuous
2
12
7.4 ± 0.5
−150~−250
0.05
21 ± 1
0.7%
75
Reactor 2
Intermittent
2
6
7.0 ± 0.5
+100~+300
2-4
21 ± 1
0.7%
50
[0062] The system SRT values were estimated based on the effluent washed out solids.
[0063] Synthetic Sewage
[0064] Synthetic sewage composition was modified from a composition developed by Kuba, et al. (1993) in terms of organic carbon and phosphorus concentrations, which contained 400 mg COD/L, 20 mg P/L and 50 mg N/L. It was prepared from 0.521 g/L NaAc, 0.067 g/L K 2 HPO 4 and 0.035 g/L KH 2 PO 4 . Appropriate amounts of nitrogen and macro minerals were added to the feed by adding 0.19 g/L NH 4 Cl, and 0.01 g/L EDTA (Kuba et al., 1993), and 2.0 ml/L trace mineral solution. The only organic substrate was sodium acetate. The sulphur source was provided by using 20% of real toilet flushing seawater instead of distilled water in the synthetic sewage. Seawater naturally contains sufficient ions of Mg 2+ , K + and Ca 2+ required for poly-P synthesis.
[0065] System Performance
[0066] When operating under the anaerobic condition, Reactor 1 performed anaerobic acetate uptake (maximum rate≈11 mg C/g VSS/h) and sulfate reduction (maximum rate≈4 mg S/g VSS/h), in concomitant with anaerobic P release (maximum rate≈6 mg P/g VSS/h). The PHA synthesized during anaerobic phase was 30±12 mg PHA-C per cycle, while the poly-S 2− /S 0 formed was 21±8 mg poly-S 2− /S 0 -S per cycle. In the subsequent anoxic condition, Reactor 1 performed denitrification (maximum rate≈10 mg N/g VSS/h) and anoxic P uptake (maximum rate≈11 mg P/g VSS/h). The stored PHA and poly-S 2− /S 0 were completely consumed during the anoxic reaction phase. In summary, Reactor 1 achieved the volumetric rates of anaerobic acetate uptake, anaerobic sulfate reduction and anoxic nitrate consumption at 115±5.5 mg C/L/d, 48±6.9 mg S/L/d and 90 mg N/L/d, respectively. Meanwhile, the volumetric P removal rate from the bulk liquid in Reactor 1 was 7.2±3.2 mg P/L/d.
[0067] In Reactor 2, most ammonia was oxidized to nitrate, with an effluent nitrate concentration of 45 mg NO 3 —N/L. All of effluent nitrate was used for denitrification and anoxic P-uptake in the anoxic reaction phase of Reactor 1.
[0068] Over all, this new bioprocess has been operated for simultaneous removal of organics, nitrogen and phosphorus, exhibiting excellent performance with COD=100%, N removal >90%, and P removal >85%. The final effluent total COD, total nitrogen (TN) and total phosphorus (TP) of Reactor 1 was about 40˜60 mg COD/L, 0˜5 mg TN-N/L, and 0˜3 mg TP-P/L.
[0069] Comparing with conventional heterotrophic bacteria, both the sulphur cycle-associated bacteria and autotrophic bacteria produced much less sludge. The average MLVSS in Reactor 1 was about 3±0.5 g VSS/L. The observed yield coefficient of Reactor 1 was 0.05±0.02 g VSS/g COD. This confirmed that nearly no biological excess sludge removal from Reactor 1 was required. The settling capacity of the sludge in Reactor 1 was good, the SVI 30 of this sludge was 48±5 ml/g, since a large amount of inorganic poly-P had been accumulated in the sludge and the MLVSS/MLSS ratio was as low as 0.6˜0.75 g VSS/g SS. The final effluent TSS was <40 mg SS/L.
[0070] Energy consumption and CO 2 emission from a treatment plant were mainly contributed from two sources: operation and sludge disposal. As there was no excess sludge removal required, we estimated that the SD-EBPR process could reduce one-third of energy consumption and greenhouse gas emission as compared with conventional biological nutrient removal process.
CONCLUSION
[0071] It is noted that, while influent and effluent is described, it is possible to pre-treat the sewage, which is likely in some areas where intermediate settling plants are used, and to post-treat the sewage, for example to reduce bacteria levels. Therefore, “influent” and “effluent” may be intermediate connections rather than the initial inflow of sewage or the final discharge of treated waste. Additionally, further processes can be included within the system within the scope of the technique.
[0072] It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated to explain the nature of the subject matter, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.
|
Sewage treatment is performed by using Sulphur to facilitate electron flow. A first cycle uses a sulphur composition having sulphur and/or sulphur compounds to transfer electrons from organic carbon to oxygen, nitrate and nitrite, and to convert phosphorus-containing compounds to solid material, which is retained in sewage sludge. The sulphur is further used to perform denitrification of nitrogen compounds. A further cycle uses oxygen to oxidize any ammonia present to nitrate and/or nitrite.
| 2
|
PRIORITY CLAIM TO PROVISIONAL PATENT APPLICATION
This patent application claims priority to U.S. Provisional Patent Application Ser. No. 61/128,458 filed on May 20, 2008.
TECHNICAL FIELD OF THE INVENTION
The present invention is generally directed to the manufacture of tools for the oil and gas producing industry and, in particular, to a system and method for providing a mechanical energy absorber that may be advantageously used in a downhole environment.
BACKGROUND OF THE INVENTION
Downhole mechanical energy absorbers can be used to protect equipment in a wellbore from dynamic loads that can arise from several sources. These sources include impacts that occur during tool run-in or that occur when tools are dropped into the wellbore. The source of the mechanical load can also be an explosive blast such as the detonations that occur during perforation operations.
The dynamic loads may vary greatly in scale of magnitude and in duration. For example, a blast load may have peaks of less than a millisecond and may induce forces of hundreds of thousands of pounds. A tool drop impact may have a slower onset but may perhaps have an even larger total kinetic energy. On the opposite end of the load spectrum, a longer duration loading event may have a gradual onset, such as when weight is set down on a tool string.
The function of a mechanical energy absorber is to absorb mechanical energy and convert kinetic energy into heat and into a controlled material deformation. In doing so, the loads that affect the tool string can be limited in magnitude. In this manner a mechanical energy absorber is both an energy absorber and a load limiter. In some downhole applications, limiting peak loads in the tool string is the primary objective of the absorber. This may also include buckling prevention. In other downhole applications, the objective may be to protect sensitive equipment within the tools, such as electronics, from high acceleration levels or shock loads. In all cases, the wellbore diameter is a major design constraint.
Many different types of mechanical energy absorbers have been developed over the past half century. Mechanical energy absorbers (also referred to as shock absorbers) have been used not only in downhole applications but also in aircraft and ground vehicles to provide protection for passengers and sensitive cargo. Many of the designs for vehicles, particularly in the aerospace industry, focus on optimizing a specific energy absorbed, where weight is a penalty. The objective of these designs is to reduce acceleration magnitude and duration to improve survivability.
The ideal linear-motion mechanical energy absorbers provide a constant load during their stroke. This load may be set to a maximum allowable level without causing damage to the systems being protected. For the ideal constant load design, the mechanical energy absorber exhibits a near zero spring-rate during its stroke. Low noise or ripple during the stroke also reduces shock loads transferred across the device.
In order to operate over the full range of downhole loading conditions, a device must be able to handle very rapid onset of force as well as handle high levels of energy absorbed. The inelastic deformation of metals has been demonstrated to be one of the best performing and most versatile and reliable means of absorbing significant mechanical energy in a continuous and uniform fashion. Because wellbore conditions and tool string geometry vary greatly, it is imperative to have a design that can be readily adapted to meet the specific requirements of each job.
Some of the simplest energy absorbers rely primarily on the elastic compression of springs or elastomeric elements. The problem with these designs is that the force is not constant but rather increases during the stroke, and the energy is only stored temporarily and thus is not truly absorbed. This results in a rebound with similar potentially damaging effects as the original shock. Performance can also change significantly with temperature.
Other designs have utilized discretized energy absorbing elements that sequentially engage to absorb energy. Each element absorbs energy only over a small portion of the total stroke of the device. The drawback of such concepts is that the load level is still not constant and will have a significant ripple or noise level.
Other designs rely on frictional forces to dissipate energy as heat. The drawback of these concepts is also a non-constant load level and a build up of heat that can lead to damage and performance degradation, particularly in a long-stroke application.
Fluid-based concepts for dissipating energy typically force a fluid through an orifice similar to automotive shocks used between the wheel or axle and the vehicle frame. These devices depend upon viscous damping and fluid shear and are highly rate-dependent and are not feasible for high rate impact or ballistic shocks. At high rates, the fluid flow cannot respond to the rapid load onset causing the forces to escalate with minimal stroke.
Applications involving vibration isolation, vibration damping, or small-amplitude wave attenuation are not directly relevant. Designs for such applications cannot absorb energy on the scale required for the intended impact and shock events described here. Instead, these designs typically focus on protecting electronics from long duration vibratory loads such as those generated while drilling.
Prior art downhole mechanical energy absorbers include the following:
U.S. Pat. No. 3,653,468 is one of the earlier downhole shock absorbers and utilizes sequential shearing of metal disks or washers to absorb energy.
U.S. Pat. No. 4,679,669 cuts chips from a mandrel using shearing cutters fixed to the housing, similar to machine tools such as on a lathe.
U.S. Pat. Nos. 5,131,470 and 5,366,013, as well as U.S. Pat. App. 2006/0118297, describe honeycomb crushing along with a damping coil for shock absorption.
U.S. Pat. No. 5,188,191 utilizes alternating metal and rubber layers to provide an impedance mismatch for reducing shock transmitted.
U.S. Pat. Nos. 6,109,355 and 6,454,012 describe a frictional interference fit with elastic deformation for energy absorption. The patents describe a uniform deformation of the tool housing with hoop stress being the primary design metric. The deformation may also be inelastic for one-time use applications.
U.S. Pat. No. 6,708,761 employs the sequentially shearing of radially-oriented metal elements, or shear pins, to absorb energy during a linear stroke.
U.S. Patent Application Publication No. 2003/0150646 uses a porous material to absorb shock loads.
U.S. Patent Application Publication No. 2004/0140090 transfers shock energy to a spring-mass system.
A more extensive history of continuously deforming or rupturing metal for energy absorption can be found outside of the oil and gas producing industry. These devices are intended for absorbing energy from the relative motion between vehicles, between vehicles and the environment, or occupants and the vehicles themselves.
U.S. Pat. No. 3,143,321 describes the continuous rupturing of a tube forced onto a die. Similar concepts were also described in NASA technical report NASA TN D-5730.
Another NASA report, NASA TN D-4941, describes a tube cutter design that cuts a tube into longitudinal strips to absorb energy for a landing gear strut. A similar approach is used in U.S. Pat. No. 5,547,148.
U.S. Pat. No. 3,394,612 utilizes interference between telescoping tubes such that the outer tube is deformed by embossments on the inner tube for a vehicle steering column energy absorber.
U.S. Pat. No. 3,779,591 uses fixed cutters to shear away material from a moving mandrel.
Similarly, U.S. Pat. No. 4,346,795 uses a cutting ring to shear away the entire circumference of the mandrel surface.
U.S. Pat. No. 4,575,026 describes a continuous plastic deformation of metal to decelerate a vehicle on a track.
U.S. Pat. No. 5,351,791 discloses a tube pushed through a reducing die and a crushing element.
U.S. Pat. No. 6,135,252 relies on metal extrusion for energy absorption.
U.S. Pat. Nos. 6,308,809 and 6,457,570 introduce stress concentrators to control the rupture of a tube.
U.S. Pat. No. 7,147,088 describes the controlled collapse of thin-walled tubes in a multi-stage design.
U.S. Pat. No. 6,371,541 shear cuts material from a metal structure with guides to control the direction of the progression.
U.S. Pat. No. 6,394,241 applies a combination of shearing and bending to absorb energy for crashworthy seats. The inventor, Desjardins, also published a history and summary of energy absorbers used for crashworthy seats in an American Helicopter Society (AHS) presentation and paper (AHS 59 th Annual Forum, May 2003).
SUMMARY OF THE INVENTION
The novel and unique design of the present invention overcomes the deficiencies of the prior art for downhole mechanical shock absorbers. The present invention (1) maximizes the limit load achievable in a constrained cross-section of the downhole tool; (2) provides a long stroke for absorbing large amounts of kinetic energy; (3) provides a constant force (near zero effective stiffness) with low noise in a smooth continuous fashion to minimize the shock loads transferred; (4) avoids chips or metal cuttings that could take up valuable space or jam the relative motion; (5) provides the toughness needed for surviving and performing under downhole and ballistic shock and impact conditions; (6) is readily adapted to meet the specific job requirements; and (7) offers the opportunity to reduce manufacturing tolerances and material costs for a low-cost system.
The present invention utilizes the continuous deformation of a tubular element or array of elements to absorb kinetic energy. As a result of external loading, a rigid or deforming element moves slidably and coaxially relative to a deformable element in order to cause the deformation. An external housing encloses the deforming element. In a first advantageous embodiment, the deforming element is a modified tube engaging internal and/or external cutting/deforming teeth. These teeth serve a dual-role as a die to force localized inelastic deformation in the tube wall and also a cutter to force rupture or tearing of the wall. The sacrificial or frangible tube is provided with stress concentrations and/or guides to control both the initiation and the propagation of the deformation zone along the axis of the tube.
The present invention provides a great deal of adaptability to different downhole applications and conditions via simple changes to the sacrificial tube and cutting teeth. Changes to the limit load, the stroke, and the rise time or load-up time can be effected to match the anticipated dynamic load characteristics and requirements for the protection of sensitive tools in the wellbore or to maintain tool string integrity. Having a deformable element that is separate from the primary structures, the inner mandrel and outer housing, is significant for achieving the advantages of adaptability and ease of manufacture. More details on the specific means of varying design parameters will be provided below.
In a second advantageous embodiment, the deforming member is a cone and the deformable element is an array of axially oriented elements that fit in the annulus between the deforming member and an external housing. The array of elements does not completely fill the annular cross section with solid material but rather has open spaces to allow for bending and shear deformation as the cone engages. The array may be joined with welds or a frame. The geometry of the deformable elements can be selected from a wide range of commercially available or custom tubular or beam materials and geometries to tailor the deformation behavior and energy absorbed per unit length of stroke. As an example, the array may consist of small steel tubes having a diameter no greater than the initial radius gap between the inner mandrel and outer housing. The array may also include a combination of elements having more than one material type and geometry. The elements are preferably selected to individually engage the cone with a line contact but may also contact over a broader area. The elements may also be embedded in a matrix or compressible filler.
The present invention is also modular and stackable and has a two-way stroke capability. In one advantageous embodiment, the device can be a compressive energy absorber. Another advantageous embodiment operates as a tensile energy absorber, and a third advantageous embodiment would include both tension and compression energy absorbers.
The modular energy absorbing elements can be stacked on a common mandrel to increase the limit load or can be stacked to operate as independent absorbers to increase the effective stroke. Multiple distributed shock absorbers can be employed in a tool string to optimize performance. Each shock absorber can be set to a unique load and stroke characteristic. A dynamic simulation of a tool string can be used to determine optimal placement and sizing of the absorbers.
The present invention maintains structural integrity after stroking so that the tool string can be removed after an impact or blast. If necessary, inadvertent stroking during tool run-in can be locked out with shear pins. This maintains an accurate tool string length to ensure placement of guns or other tools on depth. The shock absorber tool has a central bore that can serve as a flow passage or a passage for detonation cord or wiring.
In an alternate advantageous embodiment primarily for perforating applications, the shear pins that lock the shock absorber during run-in are replaced with a controlled frangible element that breaks a structural connection to free up the shock absorbing element once the guns are located on depth. This can offer the benefit of improved performance by eliminating the initial load required to shear the pins before stroking can commence. Communication to disable the lock may come from a surface device or from another downhole device. The trigger for breaking this lock-out connection can be linked to a drop bar, a telemetry system, a pressure controlled release, a temperature, a time, an acceleration, or a direct link via detonation cord to the primary explosive chain. The trigger may also be a combination of these elements. In yet another advantageous embodiment, the frangible design is replaced with a torque-controlled release, whereby a rotation of the tool string from surface is used to unlock the energy absorber when desired. In another advantageous embodiment, the absorber is activated when the tool string engages a preset downhole device such as a packer.
In some applications it may be advantageous to tailor the load profile over the stroke of the device. The present invention can be tailored for such a load profile by adjusting the sacrificial tube geometry along its length, by using multiple cutting/deforming elements distributed axially to sum their effects, or by combining the primary energy absorber with a secondary absorber that engages in parallel during a portion of the stroke to add to the load for some period. Similarly, in a second advantageous embodiment, the deforming element or element array can be varied along its length by adjusting the lengths and combinations of element materials and geometries.
The apparatus of the present invention is also redressable and most components are reusable. The deformable elements can be removed after use and replaced, leaving the housing, mandrel, and other components for reuse.
In another advantageous embodiment, the apparatus of the present invention is enabled to transfer large torque loads. This may be desirable to allow surface torque and rotation to be used to control other downhole tools in the string.
In another advantageous embodiment, the cutting teeth are oriented radially inward from the mandrel to deform a second inner sacrificial tube. Multiple concentric deforming and deformable tubular elements or arrays can be integrated within a single housing. This may offer an increased limit load capability for a given tool cross section.
In another advantageous embodiment, the cutting teeth are fixed to the outer tool housing and are oriented radially inward to deform an internal sacrificial tube.
In another advantageous embodiment, a locking mechanism is included to increase the resistance to reverse motion after the initial energy absorbing stroke. The locking mechanism may be a spring-loaded engaging lock, a set of wedging slips, or other similar device that restrains relative motion between mandrel and housing. Alternately, the deforming teeth or the deforming cone may be designed such that reverse motion locks the teeth into the sacrificial tube.
In another advantageous embodiment, a two-way absorber enables energy absorption in compression and tension. The reverse lock may be employed to prevent slippage in one unit to allow the other to engage and operate.
Downhole applications for the mechanical energy absorber of the present invention include: protecting other tools, plugs, etc. from blast loading; reducing the loads on perforating gun bodies that result from interaction with the tool string; controlling the buckling of the tool string that may result from dynamic loading events; protecting fixed tools from moving objects in the well, such as drop bars, tool strings, etc., for example, protecting a downhole valve from a falling tool or object; protecting a tool or tool string from impacts with casing or other fixed objects during run-in; protecting sensitive equipment within a tool from impact-related loading. The mechanical energy absorber of the present invention may also protect coiled tubing, wireline, or slickline tool strings from similar loads.
The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.
Before undertaking the Detailed Description of the Invention below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like.
Energy absorption refers to the conversion of kinetic energy into deformation and heat. Deformable element refers to a primary component that is deformed in order to absorb energy. The deformable element is also sometimes referred to as a sacrificial element or a frangible element. Deforming element refers to a component that acts to deform the deformable element. Localized deformation refers to a non-uniform deformation including any one of: tension, compression, bending, and shear of an element cross section as a result of an engagement with a deforming element. Continuous deformation refers to a primarily constant cross section of a deforming element along a tool axis that engages a deformable element and results in a near constant resistance to relative motion.
Inelastic deformation refers to deformation that exceeds elastic limits or the yield strength of a material. Tubular member refers to a generally cylindrical object that is hollow but may have a non-circular, complex geometry. Load limiter refers to the limiting of maximum dynamic loads and the resulting stresses in tool string structures. Stroke refers to the relative motion of the device that results in deformation and energy absorption.
Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior uses, as well as future uses, of such defined words and phrases.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:
FIG. 1A illustrates a schematic diagram of a mechanical energy absorber tool of the present invention in an initial state;
FIG. 1B illustrates a schematic diagram of a mechanical energy absorber tool of the present invention in a compressed state;
FIG. 2 illustrates a more detailed view of the mechanical energy absorber tool of the present invention showing some of its internal components;
FIG. 3 illustrates a tabbed compression ring for carrying tensile loads;
FIG. 4 illustrates a cutting ring;
FIG. 5 illustrates an end view of the cutting ring that is shown in FIG. 4 ;
FIG. 6 illustrates a sacrificial tube;
FIG. 7 illustrates an end view of the sacrificial tube that is shown in FIG. 6 ;
FIG. 8 illustrates a mechanical energy absorber tool of the present invention with its housing removed;
FIG. 9 illustrates a cross sectional view of a mechanical energy absorber tool of the present invention with its housing removed;
FIG. 10 illustrates another view of the mechanical energy absorber tool of the present invention with its housing removed;
FIG. 11 illustrates a cutting ring engaging a sacrificial tube of the mechanical energy absorber tool of the present invention;
FIG. 12 illustrates a compression ring and shear set of the mechanical energy absorber tool of the present invention;
FIG. 13 illustrates angles defining a cutting edge on the teeth of the mechanical energy absorber tool of the present invention;
FIG. 14 illustrates an angle defining a leading edge of the cutting teeth of the mechanical energy absorber tool of the present invention;
FIG. 15 illustrates an angle defining a width of a deformable sector of a sacrificial tube between ribs of the mechanical energy absorber tool of the present invention;
FIG. 16 illustrates a schematic diagram that illustrates a definition of stress concentration groove angle and depth;
FIG. 17 illustrates a schematic diagram that illustrates a definition of a starting notch including depth, angle, and tip radius;
FIG. 18 illustrates a cross sectional view of the mechanical energy absorber tool of the present invention showing an elastomer ring between a sacrificial tube and a housing shoulder;
FIG. 19 illustrates a conceptual drawing of a second advantageous embodiment of the invention shown in longitudinal section;
FIG. 20 illustrates a conceptual drawing of the second advantageous embodiment of the invention shown in transverse section;
FIG. 21 illustrates a simplified representation of metal stress-strain curve to failure;
FIG. 22 illustrates a simplified representation of mechanical energy absorber performance;
FIG. 23 illustrates a LS-DYNA® model of a ten degree sector of a cutting element engaging a sacrificial tube showing tube deformation as the cutting element moves;
FIG. 24 illustrates a LS-DYNA® model showing deformation as a cutting element moves through a sacrificial tube;
FIG. 25 illustrates a graph showing a force versus stroke simulation for cutting ring moving through a four inch (4″) length of tube at a constant speed of one hundred feet per second (100 ft/sec);
FIG. 26 illustrates a graph showing energy absorption versus stroke simulation for s cutting ring moving through a four inch (4″) length of tube at a constant speed of one hundred feet per second (100 ft/sec);
FIG. 27 illustrates a LS-DYNA® model showing a Von Mises stress distribution in a mechanical energy absorber tool of the present invention;
FIG. 28 illustrates a LS-DYNA® model showing a plastic strain distribution in a mechanical energy absorber tool of the present invention; and
FIG. 29 illustrates a LS-DYNA® simulation comparison illustrating tool string load reduction using an energy absorber.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 through 29 and the various embodiments used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any type of suitably arranged mechanical energy absorber device.
To simplify the drawings the reference numerals from previous drawings will sometimes not be repeated for structures that have already been identified.
The following description of a preferred embodiment of a mechanical energy absorber of the present invention refers to FIGS. 1A , 1 B and 2 . FIG. 1A illustrates a view of the tool assembly in an initial state. FIG. 1B illustrates a view of the tool assembly in a compressed state. The terms leading and trailing are used in reference to the direction of mandrel travel with respect to the housing. The leading housing 1 interfaces the outer structure of the tool with an uphole toolstring. The center housing 2 is connected to the leading housing 1 . The trailing mandrel 3 extends downhole from within the center housing 2 and interfaces with a downhole toolstring. As shown in FIG. 1B , after the tool assembly has been compressed, the trailing mandrel 3 enters into the center housing 2 , leaving only the downhole toolstring interface exposed.
FIG. 2 provides a more detailed view of the major components of the tool assembly. The outer components of the center housing 2 interface with the uphole tool string. The outer components of the tool assembly comprise the leading housing 1 , the central housing 2 , and the trailing housing 12 . The inner components of the trailing mandrel 3 interface with the downhole tool string. The components of the mandrel comprise the trailing mandrel 3 and the leading mandrel 14 . When the tool assembly is compressed, the mandrel components will move upward into the center housing 2 . The sacrificial tube 5 is fixed to the outer housing. The cutting element 7 is fixed to the mandrel.
A shear set comprising an inner ring 10 , outer ring 9 , and shear pins 8 is used to lock out the mechanical energy absorber until some minimum desired load is exceeded. A stopper 11 is included on the lower end of the trailing housing to prevent damage to the tool when a full stroke (i.e., a full compression) is experienced in a mechanical energy absorbing event. Hydraulic seals are included to prevent flooding of the energy absorber and to isolate the external wellbore fluid and any internal flowbore fluids. These seals are included between mating housing components 4 and 13 , mating mandrel components 6 , and the housing-to-mandrel interfaces 15 and 16 . A compression ring 17 is optionally included to provide a stiff load path when the tool is subjected to tensile loads, such as during run-in or pull-out of the tool string. When subjected to compressive loads, the tabs deform to allow for operation of the mechanical energy absorber. The compression ring 17 is illustrated in greater detail in FIG. 3 .
A number of different views of portions of the mechanical energy absorber of the present invention are provided in FIGS. 4 through 17 . The cutting element geometry is critical to the function of the mechanical energy absorber of the present invention. The cutting element of the invention is designed to operate under ballistic loads in the extreme which would likely cause failure in prior art tube-cutter designs. The cutting element experiences high stresses during operation as all forces must be transferred through these elements from the mandrel to the sacrificial tube.
The present invention utilizes a robust cutting/deforming element that utilizes a cutting wedge in concert with a deforming boss. As the stroke progresses, the cutter forces material to push radially outward into the open spaces that are placed by design in the outer diameter of the sacrificial tube. The sacrificial tube comprises an alternating pattern of web strips that will be deformed, and rib strips that interface with the housing to provide radial support. As material moves along the cutting element, the outward radial force becomes more narrowly focused to maximize local deformation. A stress concentration groove or score line on the outside of the tube further enhances the local stress due to the cutter and the combination may result in rupture or failure of the tube. The zone of local deformation and possible rupture progresses along the score line as the cutter moves along the tube. The design seeks to reduce frictional forces while maximizing the energy absorbed in the cross-section.
FIGS. 13 and 14 illustrate the cutting element geometry. The angle of the leading edge of the cutter with respect to the axis is preferably fifteen degrees)(15°) but may be designed over a range of perhaps five degrees)(5°) to thirty degrees) (30°) depending on the exact configuration. This angle is critical to controlling the maximum stresses in the cutter during operation. Transverse to this leading edge, the cutter has a wedge shape with a radius on the leading edge. The wedge angle, measured normal to the leading edge, is preferably plus or minus forty five degrees)(+/−45°). This angle may also be varied over a range. In addition, the cutter may have a rounded profile or other additional complexity that can optimize the stresses in the cutter and cutting performance.
The leading edge has a nominal one hundredth of an inch (0.01″) radius to control peak stresses in the tooth. The back edge of the cutter may be designed to resist reverse motion. It may be designed to catch and engage the edges of the material that were deformed during the forward motion. The cutting edge geometry may also be tuned to match the material and geometry selected for the sacrificial tube in a particular application and loading characteristic. The cutting elements may be part of a modular ring component, inserts that directly engage the mandrel, or integral parts of the mandrel. The array of cutting elements may be distributed in a ring or may be distributed with a varying axial offset.
The mandrel is designed to maintain alignment within the sacrificial tube. Ahead of the cutting elements, the mandrel centralizes and supports the sacrificial tube against buckling. Behind the cutting elements, the mandrel is sized to provide internal support to the remnant strips of the sacrificial tube without inducing additional friction.
The sacrificial tube geometry is shown in more detail in FIGS. 15 , 16 and 17 . The cutters initially engage the end of the sacrificial tube which has been specifically formed to provide a smooth initiation of the cutting process. The stress concentrations in this area have been amplified with deeper cuts so that the force required to rupture the web between ribs is initially less and ramps up rapidly as motion progresses. The thickness of the tube may also be tapered in this region to further control the transition to limit-load operation. The deformation zone will propagate between the ribs and may be further directed and aided by the stress concentration groove or score line. The groove provides a local stress concentration and focuses the peak stresses. The relative width and thickness of the web may be adjusted to optimize energy absorption for a particular material selection and performance objective. Consideration for cutting tooth stress and wear will also factor into the desired web stiffness as defined by the width and thickness. The open space between ribs also provides clearance for the deforming web and a pathway for gas or fluid to bypass the cutter. The geometry of the sacrificial tube may be optimized for a range of shock absorber application requirements.
The sacrificial tube can be loaded in compression or tension within the housing. The cutting mandrel can push through with the trailing end of the sacrificial tube held in tension. Alternatively, the cutting mandrel can be pulled through with the leading end of the sacrificial tube held in compression.
The tool is sealed so that internal components are not subjected to corrosion and to ensure that the stroking (i.e., compression) is not inhibited by viscous or compressibility effects in the fluid. Air flow paths are provided to allow air ahead of the mandrel to flow back across the deformation zone. Seals are included to prevent liquid from entering the annulus containing the sacrificial tube. Seals prevent flow from pressure on the interior bore or from the exterior of the tool. Sliding rod seals are mounted on the inner diameter of the housing and seal against the sliding mandrel.
In one advantageous embodiment, the sacrificial tube may be fabricated from an extrusion or casting that will allow for cost savings in volume. The design will allow for the desired cross-sectional features of the design with some finish machining being required on the tube ends and designed stress concentration features. The idealized material properties may be traded off against cost in making an optimal selection.
Tools can be designed in a variety of sizes to fit different applications. Within each basic tool size, adjustments can be made to the performance characteristics. The simplest change will be to have several interchangeable cutter ring options with different numbers of teeth or tooth geometry. Alternate tube materials or tube geometries will provide another interchangeable option. For example, the yield point or elongation at break of the tube can be selected to meet a desired performance. An example of a way to achieve this variation would be to have several different material types or even heat treat conditions as options.
Another example would be to vary the wall thickness or stress concentration geometry to change the force characteristics. The stroking length (i.e., compression length) of the tool can also be selected to optimize tool size for an application. If a modular design is used, multiple shock absorber tools can be stacked in series to provide a longer total stroke.
Materials used for mating surfaces under contact stress can be chosen to minimize galling risks such as by choosing one material to be significantly harder than the other. Lubricants may also be used to control friction. Specialized coatings may be used to enhance wear and friction properties, providing a high surface hardness or friction reduction, or both.
A shear set may be used to lock out the motion of the mechanical energy absorber until a predetermined load level is exceeded. Such loading results in shearing of the pins, allowing engagement of the teeth with the sacrificial tube. Variation in the number of pins installed and the selection of the pin material can be used to select a specific critical load level.
A stopper is optionally included to minimize the impact energy should the mechanical energy absorber reach its full stroke capability. The relatively soft bronze or similar material will undergo significant deformation, reducing peak stresses in the mating components and reducing the initiation and transfer of shock loads. Ideally, the mechanical energy absorber will be configured for a given application such that it will not reach the stop during operation.
The exposed length of mandrel may be protected from wellbore fluids using protective coatings and/or a temporary sealed containment structure. The containment, such as a thin-walled sleeve, could be filled with oil and be pressure-balanced. The sleeve would only be functional prior to the stroking of the energy absorber. The sleeve would also aid in protecting the tool from casing contact during run-in which might damage or stroke the tool prematurely.
A key or similar feature may be used to transfer torsional loads from the housing to the mandrel to prevent relative rotation of the cutting elements and the sacrificial tube. Alternately, the sacrificial tube may be allowed to freely rotate within the housing while staying aligned with the cutting elements.
A secondary mechanical energy absorber may be used in series with a primary mechanical energy absorber. As a simple example, an elastomeric layer may be integrated to reduce peak shock or acceleration levels transferred. One or more of such layers would not function well as a primary absorber of mechanical energy, but can serve to attenuate peak levels in a complementary fashion. Alternating layers of disparate acoustic impedance may offer an optimal acoustic attenuation approach. An example of this approach is described in U.S. Pat. No. 5,188,191. However, the compliance of the elastomeric layers must not compromise the functionality of the primary mechanical energy absorber and thus a relatively thin layer of elastomeric material may be incorporated. The elastomer layer or layers could be incorporated as a separate tool section in series with the primary mechanical energy absorber tool.
Alternatively, the elastomer layer can be incorporated as a ring in the interface between the sacrificial tube and the housing shoulder. This embodiment is illustrated in FIG. 18 . A separate embodiment with a similar objective would have the elastomer surrounding the sacrificial tube in the housing and coupling the two via shear as the sole load path. The elastomer may be molded in place at elevated temperature. A third embodiment would locate the elastomer between the cutter ring and the mandrel, either in a compression ring or shear load transfer configuration.
If desired, the tool can be designed as a pressure-balanced system to eliminate the seals and pressure requirements on the housing strength. The inside of the tool would be filled with a low viscosity, high lubricity, clean oil, such as mineral oil or other fluid with advantageous properties. A pressure balance bellows or other similar mechanism would allow pressure to equalize between the wellbore and the inside of the tool, allowing for the compressibility of the selected fill fluid. Modifications can be made to the mandrel, sacrificial tube, and housing to enlarge bypass flow pathways to that fluid can transfer from in front of the cutting mandrel to the backside with a minimum of resistance. For example, the open space illustrated in FIG. 7 in the grooves on the outside of the sacrificial tube can be used as a flow bypass pathway.
In some applications, the system may allow for multiple uses without replacement of any components. For example, the mandrel may travel only through a part of the total allowable stroke. Upon evaluation of the remaining stroke, the tool may be run again in its current condition should sufficient available stroke remain.
In another advantageous embodiment, the tool may be designed such that the limit load is varied over the stroke if desired in certain applications. One example of this would be to have the load gradually increase, decrease, or vary continuously by tailoring the properties or geometry of the sacrificial tube along its length. A second example would utilize a segmented sacrificial tube, where each segment has different properties or geometry. A third example would have the mandrel engage secondary cutter rings to increase the effective number of teeth deforming the sacrificial tube during the stroke. Alternatively, a parallel load path may be engaged using a secondary mechanical energy absorber during part or all of the stroke of the device.
Simpler geometries for the mechanical energy absorber of the present invention may also provide continuous deformation and possible rupture. The tube geometry may be any closed section. The cutting teeth may be simplified to bosses at the cost of increased friction. The cutting teeth may be direct cutters that cut through the tube without applying a significant radial force. The closed section of the tube may be forced to reduce in circumference and buckle inward locally in a controlled manner. The tube may be replaced by one or more strips or open sections that are forced through a deformation process that causes localized bending and/or shearing within the cross section.
Referring now to FIG. 19 , a second advantageous embodiment of the invention operates in a similar manner but with a modification to the geometry of the deforming and deformable elements. The deformable element consists of axially-oriented tubes 20 arrayed in the annular space between an inner deforming element or mandrel 19 and outer housing 18 . Each tube in the array makes a line contact with the mandrel 19 and deforms locally and continuously during the stroke of the device. The mandrel 19 consists of a small diameter leading section and a larger diameter trailing section with a conical transition 21 in between. The leading section is sized to make contact with the tube array 20 to centralize the mandrel 19 and support the tubes. The maximum diameter of the mandrel 19 determined the maximum radial deformation of the annular array. The trailing diameter provides additional support to the deformed tubes and additional centralization of the mandrel 19 . The transition geometry of the cone 21 including leading and trailing angle and external transition radius can be chosen to optimize the deformation of the deformable array of tubes.
Referring now to FIG. 20 , a transverse section view through the housing 18 , annular array of tubes 20 , and mandrel 19 is shown forward of the conical transition.
The array of tubes illustrated here a simple example of an unlimited number of possible deformable element options. Various closed or open-section tubes offer a low-cost option for selecting a desired resistance load and energy absorption per unit stroke length. The array may be formed from completely separate elements or may be joined via welding or a carrier frame. The array may be a combination of different types of elements having various material properties and geometries. As with the first advantageous embodiment, the array of the second advantageous embodiment could also be formed from a custom extrusion or casting.
Many of the same advantages and alternate embodiments as described for the primary embodiment also apply to this second embodiment and are not repeated here for brevity.
The energy absorbed by a mechanical energy absorber is a function of the force and stroke of the device. A plot of the force versus stroke for the device during operation can be used to calculate the energy absorbed from the area under the curve. An impact event will provide a certain energy input to a system. Without the mechanical energy absorber, that energy would be transferred to the system in a rather short timespan and with very high peak acceleration and loading. The mechanical energy absorber functions to convert the energy transfer from a short duration, high-amplitude event into a longer duration, constant-amplitude event. The energy is essentially spread out over time and over the stroke of the device. As a result, the impacted system is subjected to much lower acceleration and force levels.
The situation is somewhat different for perforating applications where the blast energy excites the tool string structure over an extensive length. In this case, the energy absorber and load limiter may advantageously provide a “soft” boundary within the tool string. While absorbing energy, the device also allows for local displacement and thus modifies the complex dynamic behavior of the system. This approach can be used to reduce stresses and loads across a length of the tool string including within the perforating guns themselves.
When metals yield, deform plastically or inelastically, mechanical energy is converted into rearranging the structure of the material and creating heat. Energy is absorbed in the process. Similarly, when a metal ruptures or tears, energy is also absorbed in the breaking of the bonds of the metal lattice. The stress versus strain plot for a given metal describes its yield behavior and eventual failure. The area under the curve represents the specific energy absorbed if the material is loaded to failure. Note that this curve may be strain rate-dependent. Metals for the sacrificial tube may be chosen to have a desired combination of yield strength and elongation to break to maximize the specific energy absorbed. This metric must be traded off with the wear performance of the cutting teeth as they progress through the material.
FIG. 21 illustrates a typical stress-strain curve for a metallic material. Starting from the origin with zero load and stroke, the material is first loaded and deforms elastically up to the point of yield. Above the yield point, the slope of the curve becomes much lower as plastic deformation occurs. This continues up to the point of failure. Upon failure, the load is reduced to zero and elastic deformation is reversed. The exact shape of this curve varies greatly for different materials and conditions. The area under the curve is a measure of the specific energy or energy per unit volume that is absorbed in the plastic deformation of the material.
FIG. 22 illustrates a load-stroke diagram illustrating the general behavior of a load-limiting or constant-load shock absorber. After an initial load increase to the limit load, the load remains relatively constant over an extended stroke. The load may vary over this range but stays within some noise level. The amount of material deforming inelastically in the cross section of the shock absorber determines the limit load. Finally, at the end of the designed stroke, the absorber reaches stops that engage a stiffer load path, rapidly increasing the load for any additional stroke. The length of the deformable and deforming elements sets the design stroke. The area under this curve represents the total energy absorbed by the device. The load and stroke may be traded to achieve a particular energy absorption requirement. Constraints on maximum load and maximum stroke will also drive the design.
A SOLIDWORKS® 3-dimensional solid model was developed for the mechanical energy absorber tool of the present invention. SOLIDWORKS® is a trademark of SolidWorks Corporation. The model enables the fit of the various components to be checked and for drawings to be generated for fabrication of parts. The model also allows for adaptations to the design to be made for meeting modified application requirements.
LS-DYNA® explicit finite element software was used to simulate the performance of the mechanical energy absorber. LS-DYNA® is a trademark of Livermore Software Technology Corporation. Based on the symmetry of the system, a ten (10) degree sector model spanning from the midplane between two teeth to the plane through the center of a tooth was used. The mandrel was driven with either constant force or constant velocity and the resulting motion, deformation, and stresses were predicted. Results are included in the figures for the constant velocity case at one hundred feet per second (100 ft/sec). The half-tooth travels through a four inch (4″) length of tubing before exiting. The tooth is a hardened tool steel with 180 ksi yield strength while the tube is a mild steel with 50 ksi yield strength.
The deformation, stress distribution, and plastic strain distribution illustrate the local absorption of energy as the cutter traverses the sacrificial tube. FIGS. 23 through 28 illustrate the simulation results. The sacrificial tube consists of webs joining longitudinal ribs. The webs are split by the cutting teeth. Each web segment is forced radially outward to the point of rupture. FIGS. 23 and 24 provide two views of this deformation behavior. The rupture plane is on the symmetry plane of the model slice. The ribs provide stiffness to the sacrificial tube and contact support from the pressure housing while allowing adequate space for the web to deform. Energy is absorbed not only along the plane of rupture, but also throughout most of the web where permanent bending deformation occurs. The minimal elastic recovery of the deformed web results in inward radial motion and does not impart any substantial axial force or motion on the mandrel.
The simulation results in FIG. 25 show a gradual ramp up followed by a relatively constant load. The area under the curve represents the energy absorbed during the stroke. The load is shown for a full three hundred sixty degree)(360° assembly (eighteen (18) teeth) and reaches a constant load level of sixteen thousand pounds (16,000 lbs) through the stroke. The energy absorbed in FIG. 26 is also shown for a full assembly cutting through four inches (4″) of length and absorbing five thousand two hundred foot pounds (5,200 ft-lbs).
The stress distribution during deformation is illustrated in FIG. 27 . The peak stress is distributed along the leading edge of the cutting element. The plastic strain distribution in FIG. 28 indicates the large area of inelastic deformation extending across the web of the sacrificial tube as it is deformed by the cutting element.
A second LS-DYNA® analysis was performed on a representative downhole tool string affected by a load pulse. A tool string was modeled that consisted of one hundred feet (100 ft) of tubing hung from a packer and one hundred sixty feet (160 ft) of perforating guns below. A shock absorber was inserted between the tubing and the guns. A representative triangular load pulse was applied to the bottom of the string superimposed on a hydrostatic pressure load. Such a load could represent a simplified detonation event or a tool string impact with a fixed object during the run into the well. The pulse was ten milliseconds (10 msec) wide and had a five hundred thousand pound-foot (500,000 lbf) peak amplitude and acted upwardly so as to compress the string. The shock absorber simulated a rapid linear ramp up to a one hundred fifty thousand pound (150,000 lbf) limit load in both tension and compression. A full dynamic simulation of the tool string response was run to compare strings with the shock absorber engaged and with it locked out so that it could not stroke.
The stresses and loads in the tool string were compared for simulations with and without the shock absorber. Referring to FIG. 29 , time histories of the simulated tool string responses are presented. In this figure the stress in the tubing immediately above the shock absorber is plotted for the two configurations. The results indicate a fifty percent (50%) reduction in the peak stress predicted in the tubing above the shock absorber. In addition, a sixty six percent (66%) reduction was measured in the peak stresses immediately below the shock absorber and an average twenty five percent (25%) reduction in loads was predicted across the entire string of perforating guns.
It should be noted that these analyses were performed as a simple example of the potential performance for the proposed energy absorber designs and in no way limits the range of possible design parameters or downhole applications. A key advantage of the proposed embodiments is the ease of adjusting the limit load and stroke to optimize performance for a particular tool string configuration and anticipated loading environment. Modern analysis tools enable the tool string designer to determine the best configuration for the shock absorber or shock absorbers and their placement in the tool string or wellbore for a particular job. This example illustrates the benefits of a design without any attempt to optimize.
Although the present invention has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims.
|
A system and a method provide a downhole mechanical energy absorber that protects downhole tools from impact loads and shock loads that occur during run-in contacts, tool drops, perforating blasts, and other impact events. A continuous localized inelastic deformation of a tube is a primary energy absorber in a load limiting design of the downhole mechanical energy absorber.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to European application No. EP16160125.7, having a filing date of Mar. 14, 2016, the entire contents of which are hereby incorporated by reference.
FIELD OF TECHNOLOGY
[0002] The following relates to a sliding bearing arrangement for a wind turbine and a method to service the bearing.
BACKGROUND
[0003] A wind turbine comprises one or more rotor blades. The rotor blades are connected to a hub. The rotor blades and the hub form the rotor of a wind turbine. The wind interacts with the rotor and causes a rotation of the rotor. The rotation of the rotor is transferred to an electrical generator. The rotational energy of the rotor is there transferred into electrical energy.
[0004] The rotation of the rotor is often transferred over a shaft. The rotor, the shaft and the rotor of the generator are rotatable in respect to the stationary part of the wind turbine. The hub, and in cases the shaft, need to be connected to the stationary part of the wind turbine by a bearing.
[0005] In many wind turbines the rotation of the rotor is directly transferred to the generator without the use of a gear. These wind turbines are called direct driven wind turbines, or direct drive wind turbines.
[0006] The weight and the forces acting on the rotor of the wind turbine are transferred over at least one bearing from the rotatable part of the wind turbine to the stationary part. For higher loads a plain bearing, or sliding bearing, is used in the wind turbine.
[0007] The forces acting in the sliding bearing under operation lead to wear at the sliding surface. To improve the lifetime and serviceability of the wind turbine, the main bearing is equipped with bearing pads that are exchangeable.
[0008] The bearing pads need to be accessible to be exchanged. It is therefore known to remove at least a part of a sliding surface or a bearing shell of the sliding bearing, to access and exchange the bearing pads.
[0009] It is also known to provide an opening in the bearing or the support structure to access bearing pads.
[0010] This shows the disadvantage the openings, or parts that can be removed, weaken the bearing or the support structure. This leads to additional fatigue of the bearing of the structure.
SUMMARY
[0011] An aspect relates to an improved bearing arrangement, that provides access to exchange bearing pads while at the same time retaining the stability of the structure.
[0012] A sliding bearing arrangement of a wind turbine is disclosed, whereby the arrangement comprises a first shaft and a second shaft, whereby the shafts are arranged coaxially to each other and one of the shafts is rotatable in respect to the other shaft around a common axis of rotation.
[0013] A first radial sliding bearing is arranged between the shafts to support the rotatable shaft by the stationary shaft. The first radial sliding bearing comprises bearing pads.
[0014] The first shaft comprises a collar, whereby the collar is arranged mainly perpendicular to the axis of rotation and radially overlaps at least a part of a radial surface of the second shaft.
[0015] The collar comprises a first axial sliding bearing to support axial loads between the two shafts. The collar is connected to the first shaft at a first radial position of the collar and the first axial sliding bearing is connected to the collar at a second radial position of the collar.
[0016] The collar comprises an opening in the area between the first and the second radial position, to exchange the bearing pads of the first radial sliding bearing of the bearing arrangement.
[0017] The sliding bearing arrangement comprises a stationary shaft and a rotatable shaft. The rotatable shaft needs to be supported in radial and axial direction by the stationary shaft. Therefore, sliding bearings are arranged between the stationary shaft and the rotatable shaft. The rotatable shaft is supported by two radial sliding bearings and by two axial sliding bearings.
[0018] The stationary shaft and the rotatable shaft are hollow shafts that are arranged within each other, whereby the rotatable shaft is rotatable in respect to the stationary shaft around a common longitudinal axis.
[0019] A sliding bearing is also called a plain bearing, and can be a dry bearing, a hydrostatic bearing, or a hydrodynamic bearing, for example. The bearing can be lubricated by grease or oil respectively.
[0020] A first and a second radial sliding bearing are arranged between the two hollow shafts to support the rotatable shaft in respect to the stationary shaft in radial direction. To support the rotatable shaft in respect to the stationary shaft in axial direction, the first of the shafts comprises a collar.
[0021] This collar can be attached to the first shaft by connection means, or it can be formed together with the first shaft in one piece. The collar of the first shaft radially overlaps at least a part of a radial surface of the second shaft. An axial sliding bearing can be arranged between the surface of the collar pointing towards the radial surface of the second shaft and the surface of the second shaft.
[0022] The collar attached to the first shaft thus bridges the radial gap between the first shaft and the second shaft.
[0023] The collar is connected to the first shaft at a first radial position of the collar. An axial sliding bearing is attached to a second radial position of the collar. The radial area in between the first and the second radial position of the collar comprises openings.
[0024] The openings are arranged in a way that an access to the radial gap between the first shaft and the second shaft is provided. Thus, bearing pads present between the first shaft and the second shaft can be exchanged through the openings in the collar attached to the first shaft.
[0025] Thus, the bearing pads of the radial sliding bearing, present in the gap between the first shaft and the second shaft, can be exchanged easily through the openings in the collar attached to the first shaft without the need to disassemble the mechanical structure of the sliding bearing arrangement.
[0026] Thus, service to the sliding bearing can be performed very easily and without heavy equipment like cranes.
[0027] The second shaft comprises a collar that is arranged mainly parallel to the collar of the first shaft and at the first axial sliding bearing is located between the two collars.
[0028] A collar is attached to the first shaft. The collar is arranged in radial direction. A second collar is attached to the second shaft that is also arranged in a radial direction and thus leads in parallel to the first collar attached to the first shaft.
[0029] A first axial sliding bearing is located between the two collars. The first axial sliding bearing is attached to one of the collars and the surface of the bearing pads of the first axial sliding bearing act on the surface of the second collar.
[0030] Thus, axial forces from the second shaft can be supported by the collar of the first shaft.
[0031] The first shaft is the stationary shaft.
[0032] The sliding bearing arrangement comprises a first shaft and a second shaft. The first shaft is the stationary shaft and the second shaft is the rotatable shaft. The first shaft comprises a collar that bridges the gap between the first shaft and the second shaft.
[0033] This collar comprises openings that are arranged in a way that the pads of the radial sliding bearing present in the gap between the first shaft, thus the stationary shaft and the second shaft, thus the rotatable shaft, can be exchanged through the openings in the collar.
[0034] The first shaft is the outer one of the coaxially arranged shafts.
[0035] The first shaft and the second shaft are coaxially arranged within each other. The first shaft is the outer shaft. A radial sliding bearing is present between the outer and the inner shaft.
[0036] The outer shaft comprises a collar that comprises openings that are arranged in a way at the bearing pads of the radial sliding bearing present in the gap between the first shaft and the second shaft can be exchanged through the openings in the collar.
[0037] The bearing pads of the first sliding bearing are attached to a first shaft.
[0038] A first shaft comprises a recess to retain a bearing pad of the first radial sliding bearing, whereby the recess is in communication with the opening and the collar of the first shaft so that the bearing pad can be removed and exchanged by moving it along the recess and through the opening.
[0039] The first sliding bearing present between the first shaft and the second shaft comprises bearing pads. The first shaft comprises a recess, whereby a bearing pad can be slid into the recess of the first shaft and the recess keeps the bearing pad in place with the bearing arrangement.
[0040] The recess of the first shaft is in communication with the opening in the collar of the first shaft. The bearing pad can be slid along the recess and through the opening in the collar to be exchanged.
[0041] Thus, an exchange of the bearing pads of the first radial sliding bearing present between the first shaft and the second shaft is possible through the opening in the collar of the first shaft. Thus, the bearing pads can be exchanged easily by sliding them along the recess and through the opening.
[0042] In addition, the bearing pads are kept in place and cannot alter their position along the circumference of the bearing as they are held back in the recess of the first shaft.
[0043] The collar of the first shaft comprises a structure that enframes the collar of the second shaft to support the second axial sliding bearing that acts on the collar of the second shaft in the opposite direction than the first axial sliding bearing.
[0044] Axial forces between the first and the second shaft need to be supported in both axial directions. Therefore, a first and a second axial sliding bearing are needed. The first shaft comprises a collar and a second shaft comprises a collar. A first axial sliding bearing is arranged at the collar of the first shaft and acts on the collar of the second shaft.
[0045] The collar of the first shaft comprises an arrangement of a u-shaped form seen in a cut in parallel to the axis of rotation of the shafts. This u-shaped form enframes the collar of the second shaft.
[0046] A second axial sliding bearing is arranged at the u-shaped form of the collar of the first shaft and acts on the opposite side of the collar of the second shaft than the first axial sliding bearing. Thus, axial forces in both directions of the axis of rotation can be supported by the sliding bearing arrangement.
[0047] The collar of the first shaft is connected to an axial end of the first shaft.
[0048] The collar of the first shaft is connected to an axial end of the first shaft. It bridges the gap between the first shaft and the second shaft and at least partially overlaps with an axial end of the second shaft, and thus with an radial surface of the second shaft.
[0049] Thus, an axial bearing can be arranged between the collar of the first shaft and the axial end of the second shaft to support axial loads. An axial end of the first shaft is an end of the first shaft in axial direction of the bearing arrangement.
[0050] This axial end of the first shaft may comprise a radial surface and a collar can be connected to the radial surface.
[0051] The sliding bearing arrangement comprises a second radial bearing between the first shaft and the second shaft in a certain predetermined distance to the first radial sliding bearing to support radial loads or tilting moments.
[0052] For a better support of radial forces and tilting moments in the bearing arrangement, a second radial bearing is present to support the rotatable shaft in respect to the stationary shaft.
[0053] The second radial bearing is arranged in a certain distance from the first radial bearing, whereby the distance between the two radial bearings is at least 0.5 m, preferably more than 1 m, and for bigger sliding bearing arrangements of wind turbines most preferably more than 2 m.
[0054] Due to the distance between the first and the second radial sliding bearing, a certain lever is present to take up the tilting moments and the radial loads in the bearing.
[0055] The first shaft is more rigid and the area of the first radial sliding bearing than the area of the second radial sliding bearing.
[0056] The first and the second shaft are hollow shafts with a mainly cylindrical wall, whereby the wall of the first or the second shaft can at least in parts also be conical.
[0057] The first shaft and also the second shaft show a certain thickness of the wall of the cylindrical or conical sections. The wall thickness of the shafts varies depending on the position along the axis of rotation.
[0058] A first and a second radial sliding bearing are present between the first and the second shaft. The first shaft shows a bigger wall thickness in the area where the first radial sliding bearing is attached to the first shaft.
[0059] Thus, the first shaft can take up higher forces in the area of the first radial sliding bearing.
[0060] The second shaft is more ridged in the area of the second radial bearing than in the area of the first radial bearing.
[0061] Also the second shaft can show a varying thickness of the wall of the shaft. The wall of the second shaft can by cylindrical or conical in parts. The wall thickness of the second shaft can vary along the axis of rotation of the bearing arrangement.
[0062] The thickness of the wall of the second shaft is higher in the area of the second radial sliding bearing. Thus, the second shaft can take up higher forces in the area of the second radial sliding bearing than in the area of the first radial sliding bearing.
[0063] Thus, the thickness of the shaft and thereby the material needed for the shaft is optimized to the loads and forces that need to be transferred. Thus, the amount of material needed is optimized to the use of the sliding bearing arrangement.
[0064] The second radial bearing is a sliding bearing that comprises bearing pads and the bearing pads are arranged in openings in the first shaft.
[0065] A second sliding bearing is arranged between the first shaft and the second shaft. The first shaft and the second shaft are coaxially arranged hollow cylindrical shafts. The bearing pads of the second sliding bearing are mounted in openings in the first shaft.
[0066] Thus, the bearing pads of the second sliding bearing can be introduced into the bearing through the openings, and can be exchanged through the openings.
[0067] At least one axial sliding bearing comprises bearing pads and the bearing pads are arranged in openings in the collar structure of the first shaft.
[0068] Axial forces between the first shaft and the second shaft are supported by an axial sliding bearing. The axial sliding bearing is arranged at the collar that is connected to the first shaft.
[0069] The collar comprises openings and the bearing pads of the axial bearing can be introduced into the bearing through the openings. The bearing pads of the axial sliding bearing can be exchanged through the openings for the axial sliding pads in the collar.
[0070] The second shaft is at least partially arranged radially inward of the first shaft and a collar connected to the first shaft is reaching from the first shaft radially inwards in the direction of the center axis of the first shaft.
[0071] Thus, the collar connected to the first shaft, which is the outer shaft, bridges the gap between the first shaft and the second shaft and can support an axial sliding bearing that abuts on the second shaft.
[0072] At least one opening in the collar of the first shaft comprises a liquid-tight cover, thus the opening in the collar can be closed in a way that a lubrication present in the bearing can be retained in the bearing arrangement.
[0073] Lubrication in the bearing can for example be grease or oil. A liquid-tight cover in the opening of the collar of the first shaft prevents the oil from flowing out of the bearing.
[0074] A method is disclosed to exchange a bearing pad of a sliding bearing arrangement of a wind turbine, whereby the arrangement comprises a first shaft and a second shaft, whereby the shafts are arranged coaxially to each other and the one of the shafts is rotatable in respect to the other shaft around a common axis of rotation.
[0075] The first radial sliding bearing is arranged between the shafts to support the rotatable shaft by the stationary shaft. The first radial sliding bearing comprises bearing pads.
[0076] The first shaft comprises a collar, whereby the collar is arranged mainly perpendicular to the axis of rotation and radially overlaps at least a part of the radial surface of the second shaft.
[0077] The collar comprises a first axial sliding bearing to support axial loads between the two shafts. The collar is connected to the first shaft at a first radial position of the collar, and the first axial sliding bearing is connected to the collar at a second radial position of the collar.
[0078] The collar comprises an opening in the area between the first and the second radial position. The method comprises the step of exchanging a bearing pad of the first radial sliding bearing through the opening in the collar of the first shaft.
BRIEF DESCRIPTION
[0079] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:
[0080] FIG. 1 shows an embodiment of a sliding bearing arrangement;
[0081] FIG. 2 shows a stationary shaft of an embodiment of the sliding bearing arrangement;
[0082] FIG. 3 shows a stationary shaft of an embodiment of the sliding bearing arrangement with the bearing pads arranged at the stationary shaft;
[0083] FIG. 4 shows an embodiment of the sliding bearing arrangement in a perspective view;
[0084] FIG. 5 shows an embodiment of the sliding bearing arrangement in a second perspective; and
[0085] FIG. 6 shows the use of an embodiment of the sliding bearing arrangement in a wind turbine.
DETAILED DESCRIPTION
[0086] FIG. 1 shows a sliding bearing arrangement; the sliding arrangement can be used for a wind turbine.
[0087] The sliding bearing arrangement comprises a stationary shaft 1 and a rotatable shaft 2 , that are arranged coaxially within each other and rotatable in respect to each other around an axis of rotation 10 .
[0088] The arrangement comprises two radial bearings 4 , 5 that support the rotatable shaft 2 in respect to the stationary shaft 1 in radial direction. The radial bearings 4 , 5 are sliding bearings.
[0089] The stationary shaft 1 comprises a collar that is arranged perpendicular to the axis of rotation 10 . The first radial sliding bearing 5 is arranged between the rotatable shaft 2 and the stationary shaft 1 .
[0090] The collar that is attached to the stationary shaft 1 comprises an opening 8 that allows an exchange of the bearing pad of the first radial sliding bearing 5 .
[0091] The collar that is connected to the stationary shaft 1 comprises a sliding bearing 7 that supports the rotatable shaft 2 in axial direction. The collar comprises an opening 13 that allows the exchange of the sliding pads of the axial bearing 7 . The sliding pads of the axial bearing 7 are arranged in the opening 13 of the collar.
[0092] A carrier arrangement 15 is connected to the collar, whereby the carrier arrangement 15 comprises a second axial sliding bearing 6 to support the rotatable shaft 2 in respect to the stationary shaft 1 in axial direction.
[0093] The axial sliding bearings 6 and 7 support the rotatable shaft 2 in different axial directions. Thus, the rotatable shaft 2 is fixed in its axial position in respect to the stationary shaft 1 .
[0094] To support the rotatable shaft 2 , the rotatable shaft 2 comprises a collar 9 and the axial sliding bearing 6 and 7 act on the collar 9 of the rotatable shaft 2 .
[0095] The openings 8 in the collar of the stationary shaft 1 can be closed by a lid so that lubricant present in the sliding bearings 5 , 6 and 7 can be retained within the bearing arrangement.
[0096] The second radial sliding bearing 4 is arranged in an opening 11 that allows an exchange of the bearing pad of the second radial sliding bearing 4 .
[0097] The sliding bearing arrangement can be used for a wind turbine, therefore the rotatable shaft 2 comprises a flange 3 that can be connected to the rotor of an electrical generator of a wind turbine.
[0098] FIG. 2 shows a stationary shaft 1 of a sliding bearing arrangement.
[0099] The stationary shaft 1 comprises openings 11 , whereby pads of a radial sliding bearing 4 can be arranged in the openings 11 .
[0100] The stationary shaft 1 comprises recesses 14 , whereby the recesses 14 are prepared to hold sliding pads of a first radial sliding bearing 5 .
[0101] FIG. 3 shows a stationary shaft of the sliding bearing arrangement with the bearing pads arranged at the stationary shaft.
[0102] FIG. 3 shows a stationary shaft 1 of the sliding bearing arrangement.
[0103] At the radial sliding bearing 4 , bearing pads are arranged in the openings 11 of the stationary shaft 1 . For the first radial sliding bearing 5 , bearing pads are arranged in the recesses 14 of the stationary shaft 1 .
[0104] The bearing pads of the second radial sliding bearing 4 can be exchanged through the openings 11 . The bearing pads of the first radial sliding bearing 5 can be exchanged by sliding them along the recesses 14 in parallel to the inner wall of the stationary shaft 1 out of the recesses 14 at the end of the stationary shaft 1 .
[0105] FIG. 4 shows the sliding bearing arrangement in a perspective view.
[0106] The stationary shaft 1 and the rotatable shaft 2 are hollow shafts that are arranged coaxially within each other. The rotatable shaft 2 is supported in respect to a stationary shaft 1 by two radial sliding bearings 4 , 5 and by two axial sliding bearings 6 , 7 .
[0107] The second radial sliding bearing 4 is arranged at one end of the stationary shaft 1 . The first radial sliding bearing 5 is arranged close to the other end of the stationary shaft 1 .
[0108] The bearing pads of the second radial sliding bearing 4 can be exchanged from the outside of the stationary shaft 1 in a radial direction. The bearing pads of the first radial sliding bearing 5 are arranged in a radial gap between the stationary shaft 1 and the rotatable shaft 2 . The bearing pads of the first radial sliding bearing 5 can be exchanged by sliding them out of the gap between the stationary shaft 1 and the rotatable shaft 2 in axial direction.
[0109] At the end of the stationary shaft 1 close to the first radial sliding bearing 5 , the stationary shaft 1 comprises a collar that bridges the radial gap and overlaps the rotatable shaft 2 . The collar at a stationary shaft 1 is needed to support the first and the second axial sliding bearing 6 , 7 .
[0110] The collar comprises openings 8 that are through-going openings in the collar of the stationary shaft 1 , and that are arranged in a way that the bearing pads of the first radial sliding bearing 5 can be exchanged by sliding them out of the gap between the stationary shaft 1 and the rotatable shaft 2 through the openings 8 in the collar.
[0111] The collar connected to the stationary shaft 1 comprises a first axial sliding bearing 7 and a support arrangement 15 to support a second axial sliding bearing 6 . The pads of the axial sliding bearing 6 , 7 can be arranged through openings in their respective support arrangement in axial direction.
[0112] FIG. 5 shows the sliding bearing arrangement in a second perspective.
[0113] FIG. 5 shows the sliding bearing arrangement from the side of the collar attached to the stationary shaft 1 . The stationary shaft 1 supports the rotatable shaft 2 that is arranged within stationary shaft 1 . The radial forces are supported by radial bearings 4 , 5 . The axial forces are supported by axial bearings 6 , 7 . The rotatable shaft 2 comprises a collar 9 and the pads of the axial bearings 6 , 7 act on the collar 9 of the rotatable shaft 2 . The axial bearing 7 is connected to the collar attached to the stationary shaft 1 .
[0114] The axial bearing 6 is connected to a support structure that is attached to the collar of the stationary shaft 1 . The collar of the stationary shaft 1 comprises openings 8 that are arranged in a way that the bearing pads of the second radial sliding bearing 5 can be exchanged through the openings 8 .
[0115] The bearing pads of the second radial sliding bearing can be slid out of the radial gap between the stationary shaft 1 and the rotatable shaft 2 and through the opening 8 .
[0116] FIG. 6 shows the use of a sliding bearing arrangement in a wind turbine.
[0117] The sliding bearing arrangement comprises a stationary shaft 1 and a rotatable shaft 2 . The stationary shaft 1 is connected to the stator 17 of an electrical generator.
[0118] The rotatable shaft 2 is connected to the rotor 16 of the electrical generator. Therefore, the rotatable shaft 2 comprises a flange 3 . The rotor of the electrical generator is connected to the flange 3 at one side, and over a support bearing 18 to the stationary shaft 1 at the other end.
[0119] The illustration in the drawings is in schematic form. It is noted that in different figures, similar or identical elements are provided with the same reference signs.
[0120] Although the present invention has been described in detail with reference to the preferred embodiment, it is to be understood that the present invention is not limited by the disclosed examples, and that numerous additional modifications and variations could be made thereto by a person skilled in the art without departing from the scope of the invention.
[0121] It should be noted that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.
|
A sliding bearing arrangement for a wind turbine and a method to service the bearing is provided. A sliding bearing arrangement of a wind turbine includes a first shaft and a second shaft, whereby a first radial sliding bearing is arranged between the shafts. The first radial sliding bearing includes bearing pads. The first shaft includes a collar, whereby the collar is arranged mainly perpendicular to the axis of rotation, and radially overlaps at least a part of a radial surface of the second shaft. The collar includes an opening to exchange the bearing pads of the first radial sliding bearing of the bearing arrangement.
| 5
|
PRIOR APPLICATIONS
This is a continuation-in-part of co-pending application Ser. No. 07/811,940, filed Dec. 23,1991, U.S. Pat. No. 5,259,500.
BACKGROUND OF THE INVENTION
The present invention relates to odd component (i.e. size, geometry or production run length) packaging systems and, in particular, to a wound tape, component feeder assembly for packaging single or multiple small components, especially electronic components at seriatim covered, tape storage locations in indexed relation to each other and the tape.
Varieties of tape media have been developed for storing and conveying components within varieties of packaging systems which sequentially remove or mount the components to the tape carrier. Many of the tape carriers provide a substrate that includes one or more rows of apertures which mate with system conveyor drive sprockets. The system driver thereby appropriately conveys the tape contents to particular sites within the system.
The packaged components of many prior systems have been limited to components of uniform size and shape. In some systems components are secured to the tape carrier with removeable fastener or binding strips which longitudinally coincide with the tape carrier and which are secured to the carrier at either side of each component. The binding strips can be mounted to one or both of the upper and lower tape surfaces. Typically, the binding strips are treated as waste, although they may be re-used in certain arrangements. Examples of some of such systems and tapes can be found upon directing attention to U.S. Pat. Nos. 3,135,375; 3,129,814; 3,140,773; 3,920,121; and 4,852,737.
Applicant is also aware of systems wherein the tape carrier includes flap portions which are hinge coupled along one edge to the tape carrier. An opposite or other edges either permanently or detachably mount to the carrier. The contained components are thus insertable either from the side or vertically from above the tape. Various of such assemblies can be found upon directing attention to U.S. Pat. Nos. 4,621,486; 4,631,897; and attention to U.S. Pat. Nos. 4,621,486; 4,631,897; and 4,867,308.
Although these latter systems provide advantages by way of containing the component fastener mechanism to the tape carrier, the component accessing portion of the user system must accommodate the fastener media. This, oftentimes and necessarily, implies greater spacing between components.
A variety of tape systems have also been developed which provide component storage compartments. The compartments are formed either by way of thickened tape substrates or cavities which are formed into the substrate. Some examples can be found upon directing attention to U.S. Pat. Nos. 4,069,916; 4,657,137; 4,708,245; 4,898,275 and 3,861,560.
Various of the latter references disclose thermal formed storage compartments. The compartments are not particularly molded to the configuration of the contained component. Some require a separate, co-extensive and non-reusable binding tape. The binding tape of the U.S. Pat. No. 4,708,245 is reusable, but the longitudinal fasteners must be separately secured to the tape carrier to restrain one to the other; correspondingly, the tape fabrication costs and complexity of component extraction equipment increase proportionately.
Many of the foregoing tapes satisfactorily accommodate many conventional, low cost components. However, as the complexity of many small components has increased, due to the downsizing of many larger assemblies into smaller, more dense integrated circuits or hybrid assemblies, it has become increasingly desirable to contain each component at a conformal storage location. Such a location must not only conformably surround the component, but also support the lead wires to prevent bending or breakage. Desirably, the tape carrier should provide lead wire support apertures and/or include means for indexing and registering each component to the carrier generally or within a tape storage location containing a number of components.
Lead wire apertures and detachable support platforms are partially accommodated in U.S. Pat. Nos. 4,583,641 and 4,757,895. The components are secured to the tape with a longitudinal binder strip that requires a separate take-up assembly. Each storage location is intended to contain only a single component and no provision is made for tilt control or gripper finger pickup spacings.
Appreciating the foregoing deficiencies of existing tape carriers, Applicant has developed a carrier which provides for closely spaced component storage locations. The storage locations are conformably configured to the components to be stored and permit mounting of multiple components at each storage location. Each location is freely accessible from all directions for loading/unloading or test, upon removal of a conformal cover which is replaced after each access; thus minimizing waste. Each storage location further includes a component support pallet which can be replaced, when worn, or substituted to accommodate another component type, thus reducing attendant inventory costs to the tape manufacturer. The taper carrier thereby has a relatively long life and maybe re-used for many different components.
SUMMARY OF THE INVENTION
It is accordingly a primary object of the present invention to provide a tape carrier including a plurality of component storage sites or housings on a tape substrate with each site including a discrete, removable cover.
If is a further object to provide a tape carrier which is re-usable and accommodates a wide variety of sizes and shapes of components.
It is a further object of the invention to provide a tape carrier having a plurality of seriatim spaced, component storage housings including a raised sidewall portion containing fastener portions which project to resiliently receive a component support pallet comprising the bottom of the housing and wherein the cover also interconnects with the pallet and housing.
It is a further object of the invention to provide a component pallet including alignment apertures, cavities or raised projections, whereby one or more components may be supported in a flat or edge-mounted condition and in indexed relation to each other and the housing on a single pallet.
It is a further object of the invention to provide an automatic, static electricity free system.
It is a further object of the invention to provide a wound tape cartridge including a shuttered door which interacts with a tape splice connector block.
It is a further object of the invention to provide mating connector blocks at a tape cartridge leader and the trailer end of a tape carrier.
It is a further object of the invention to provide tape reel drive means for advancing a tape carrier and a connector splice block gripper means for coupling/uncoupling the ends of the tape carrier to the cartridge mounted leader.
It is a further object of the invention to provide a server assembly exhibiting cyclic operation between upper and lower tape cartridge mountings.
It is a further object of the invention to provide an indirect, sprocket pin containing tape drive means which accommodates tape slippage.
It is a further object of the invention to provide a means for removing/replacing the component covers on a non-interfering basis at each component storage site.
It is a further object of the invention to provide component loading/unloading means including component test fixtures.
It is a further object of the invention to provide component loading/unloading means including tape hold-down fingers and pallet insertion or extraction means.
It is a further object of the invention to provide a component insertion/extraction tool having multiple, selectable tool heads which is positionally indexed to the pallet, regardless of component or tape alignment.
It is a further object of the invention to provide a tool head that facilitates tool changes.
It is a further object of the invention to provide gripper assemblies containing ball bearing suspensions to support each tool head.
It is a still further object of the invention to provide plug mounted pneumatic or hydraulic and electrical control means.
It is a still further object of the invention to provide a system having tool heads which are controllable at four axes and which system is easily reconfigurable, mechanically and electrically.
Various of the foregoing objects, advantages and distinctions of the invention are notable within a presently preferred construction. Depending upon an application environment the invention is useable alone or in any system configuration wherein multiple odd component feeders are required to cooperate with a component supply source or a work object station. The latter may comprise a printed circuit board assembly station and the former might comprise an electronics component packing station.
Regardless, each of the present feeder or server assemblies provides a housing including a microprocessor controller and associated positionally indexed electro-mechanical controls. Mechanical control assemblies plug mount to an interface portion of the housing in a fashion similar to the printed circuit boards.
The aft end of the feeder housing provides upper and lower tape component cartridge receiving tracks. A spool or reel drive assembly projects from the housing to frictionally cooperate with a component containing tape carrier wound about the reel drive assembly advances a tape leader or the trailer end of the tape carrier to a splicing assembly where mating connector blocks are coupled to interconnect the supply and take-up cartridges. The splicing assembly includes means for actuating a splice block interconnect.
A driven sprocket tape, which mates with apparatus spaced along the tape carrier, projects from the feeder housing in relation to guide rails and conveys the component containing tape carrier along the housing. A cover removal assembly is vertically and longitudinally actuable to release the cover from the tape carrier; retain the cover at a distance from filling or extraction operations and replace the cover upon the completion of component filling or extraction.
Component manipulation otherwise occurs at lift-and-locate means which includes clamp means for restraining the tape to the housing and means for inserting a conformal component support pallet to the tape carrier. The insertion means may include electrical or mechanical test fixtures which test one or more contained components.
An overlying gantry framework supports an interchangeable tool changer assembly. The tool changer supports a multi-faceted, rotating tool head that contains a number of multi-fingered tools and means for positioning a specific tool at an operating position. A gripping means expands and contracts the tool fingers to grasp and release the components. A ball bearing suspension at each gripper provides a smooth and reliable action.
The tape substrate provides a plurality of seriatim component storage sites or housings. Each site includes resilient fastener means for coupling to vertically aligned component support pallets. The pallet defines the bottom of the housing. Each pallet provides appropriate apertures, formed projections and/or cavities to support one or more components and associated leads in a flat or edge-mounted condition. Each cover similarly contains conformal surfaces for mating with the contained components and complementary means for resiliently containing the cover at each storage site to the tape annulus and pallet.
Still other objects, advantages and distinctions of the invention will become more apparent from the following detailed description of one presently preferred embodiment with respect to the appended drawings. To the extent various modifications or improvements have been considered, they are described as appropriate. The description is intended to be illustrative only, and the scope of the invention should not be interpreted in strict limitation thereto. Rather, the invention should be interpreted within the spirit and scope of the following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan drawing of one multi-feeder, packaging system and cartridge support server.
FIG. 2a is a plan drawing of a component placement work station or workcell, supported by a number of component feeders.
FIG. 2b is a plan drawing of an alternative workcell and arrangement of the component feeders and control arm.
FIG. 3 is an elevation drawing shown in partial cutaway of one of the component feeder stations including a tool head containing gantry.
FIG. 4 is a perspective drawing of a component feeder station wherein the tape cartridges and tool head and gantry are shown in exploded assembly.
FIG. 5 is a perspective drawing of the tape cartridge door opener assembly.
FIG. 6 is a perspective drawing shown in exploded assembly of the tape splicing assembly and the tape splice blocks.
FIG. 7 is a perspective drawing of the connected tape ends.
FIG. 8 is a perspective drawing of the clutch driven, pinned drive tape assembly.
FIG. 8a is a detailed cross section drawing of a portion of the drive tape in relation to a typical tape carrier.
FIG. 9 is a perspective drawing of the cover removal assembly shown in retracted relation to the tape carrier clamping assembly.
FIG. 10 is a detailed perspective drawing of the tape carrier clamping assembly.
FIG. 11 is a perspective drawing of an electronic test platform useable with the assembly of FIG. 10.
FIG. 12 is a perspective drawing of a pneumatic/fluid test platform useable with the assembly of FIG. 10.
FIG. 13 is a perspective drawing of the gantry and multi-faceted component tool head.
FIG. 14 is a detailed perspective drawing of the multi-faceted tool head and the tool head changer.
FIG. 15a is a detailed perspective drawing of the tool head changer of FIG. 14.
FIG. 15b is a detailed perspective drawing of a high current electrical connector to the tool head changer.
FIG. 15c is a detailed perspective drawing of the multi-faceted tool head.
FIG. 15d is a side elevation drawing of a four-position tool head.
FIG. 15e is a side elevation drawing of a five-position tool head.
FIG. 15f is a detailed perspective drawing shown in cutaway of the parallel gripper portion of the tool head.
FIG. 15g is a detailed perspective drawing shown in partial explosed assembly of an improved gripper assembly containing a ball bearing suspension.
FIG. 16 is a perspective drawing shown in exploded assembly drawing of a component tape cartridge.
FIG. 17 is a perspective drawing shown in exploded assembly of one palletized component storage location.
FIG. 18 is a perspective drawing of a section of tape carrier including pallets for supporting dual-in-line (DIP) components.
FIG. 19 is a perspective drawing of a section of tape carrier including pallets having resilient component grasping projections.
FIG. 20 is a perspective drawing of a section of tape carrier including component fastener clips, with friction walled projections.
FIG. 21 is a perspective drawing of a section of a tape carrier wherein the pallet includes projections for indexing and supporting a plurality of populated, edge mounted, thick film hybrid components.
FIG. 22 is a perspective drawing of a section of a tape carrier wherein the pallet includes indexed recesses for supporting edge mounted components and provides spacing allowing component pickup.
FIG. 23 is a perspective drawing of a section of a tape carrier wherein the pallet includes a multi-apertured recess for receiving surface mount components.
FIG. 24 is a perspective drawing of a section of a tape carrier, similar to FIG. 23 but including lead wire spacer tabs.
FIG. 25 is a functional block diagram of the plug-mounted hydraulic/pneumatic and electrical controller.
FIGS. 26A through 26G, inclusive, show a generalized flow diagram of controller operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a top plan view is shown of the organizational layout of one possible, relatively sophisticated odd component packaging or feeder system 2. The system 2 incorporates numerous tape cartridge feeder stations or feeders 4 of the present invention. The particular details of the feeder station 4 will be discussed in detail in the following description.
For the system 2, a number of feeder stations 4 are positioned between a transversely mounted cartridge server conveyer 5, a cartridge loading means 6 and a component conveyor 8 or assembly station (reference FIGS. 2a, 2b). Depending upon the system function, whether packaging odd components within the cartridges 9 or unloading odd components from the cartridges 9, the server 6 conveys cartridges 9 to and from each of the individual feeder stations 4 in response to control signals identifying the filled/empty status of each of the cartridges 9.
The server 6 in response to the control signals induces a driven lead screw assembly 10 to positionally align a cartridge carrier 12 in relation to a particular one of the plurality of feeder stations 4. A slide arm 14 of the carrier 12 is activated to induce an empty slide tray 16 to extend and engage one of the component cartridges 9 of the selected feeder station 4. The cartridge 9 can either be filled or empty.
Upon grasping the cartridge 9, the slide tray 16 is retracted and withdrawn into registration with the carrier 12. Either the same or a second slide arm 14 containing a complementary filled or empty cartridge 9 is next indexed into alignment with the feeder 4 and extended to cause its cartridge to engage with the feeder 4. The parallel server conveyor 5, in turn, automatically replenishes the server carrier 12 with appropriate cartridges and extracts the populated or depleted cartridges 9. In a less automated setting, one or more of the foregoing functions can be performed manually.
Mounted in transverse relation to the opposite end of each of the plurality of feeder stations 4 is a component or work object conveyer 8. If the system is populating the tape cartridges 9, each feeder 4 may include a gantry mounted pick-and-place assembly 26 (reference FIG. 3) to select parts from the conveyor 8 and populate its cartridge 9. Alternatively, a plurality of assemblies, such as printed circuit boards (PCB) 7, may be conveyed in controlled relation to each feeder 4 or may be stationed at a number of component placement stations, where the PCB's are populated with parts extracted from the tape cartridges 9 of the feeder stations 4.
Where the PCB's 7 are being conveyed from feeder-to-feeder, each feeder station 4 may provide a particular component type, which may be the same or different from each neighboring station 4. Regardless, each feeder station 4 selectively extracts the components of the cartridges 9 and positionally mounts the components to each PCB 7. Upon incrementally advancing each PCB 7 past the feeder stations 4, each PCB 7 can be substantially populated with minimal human intervention.
With reference to FIG. 2a, a component placement station 19 is shown wherein nine feeder stations 4 are positioned relative to a transverse conveyer 20 including printed circuit boards 22. The PCBs 22 are populated via a single robotic control arm 24 having a single tool head which selects appropriate components from each feeder station 4 under system control. In contrast, the feeder stations 4 of the system 2 each include a single gantry arm assembly 26 containing a multi-faceted pick-and-place tool head 33, which will be described below.
FIG. 2b depicts an alternative component placement station 19. Instead of an articulating robotic arm 24, a single track mounted gantry assembly 29 is provided which contains a single multi-faceted tool head (not shown). Tool head movement is directed above the feeders 4 and conveyor 20 within known coordinates of a pre-defined Cartesian workcell. That is, the gantry 29 moves longitudinally along the rails 27 and 31, while the tool head extends and retracts along the gantry and laterally of the conveyor 20. Specific gantry and tool head movement is determined for four axes of motiion (X, Y, Z and theta rotate) under system control relative to the location of the component pallet, the PCBs 22 being populated and the available components at the feeders 4.
With attention next directed to FIGS. 3 and 4, a detailed elevation and exploded assembly drawing are shown of one of the feeder stations 4 of FIG. 1. For the depicted construction, a gantry arm assembly 26 is provided at each feeder 4 which contains a multi-faceted, tool head 33. As apparent from FIGS. 2a and 2b, the structure of each feeder 4 and station can be modified, depending upon the system requirements.
Generally, each feeder 4 is configured about a frame superstructure that is covered with a sheet metal cabinet or housing 28. The housing 28 contains the feeder control assemblies (i.e. pneumatic/hydraulic and electric), a control panel 30 and the associated tape handling assemblies which are described in greater detail below. The control panel 30 interacts with a multi-board, microprocessor based electronic controller 32 and associated solenoid activated, pneumatic and hydraulic controls, reference FIG. 25. Typically, twelve solenoids 31 are provided with each feeder 4. A plurality of plug-in ports 38 permit coupling appropriately sized pneumatic and electrical supply sources and communication lines (not shown) to power the feeder 4. Mating couplers connected to a service table (not shown) interface with the feeder at locating pins 34 which extend from a support base 36.
FIGS. 26A through 26G disclose a functional flow diagram of the operational source code implemented in on-board PROM memory 40. Additional instructions can be programmed by the system user via a micro computer 42 into memory associated with the microprocessor controller board 44.
Mounted to a forward and operator accessible surface of the housing 28 is the control panel 30. A plurality of manual control switches, push buttons, pilot lights and the like are mounted to the panel and interface with the microprocessor board 44 via an input board. FIG. 25 depicts more of the details of the manual controls. Most typically, the controls are accessed during initial system and feeder setup or manual operation, such as when initially splicing the tape cartridges together or when performing maintenance on the feeder.
Secured to the upper and lower aft surfaces of the housing 28, just forward of the control panel 30, are dove tail slide track assemblies 46, reference FIG. 4. The track assemblies 46 receive and contain the supply and take-up component cartridges 9. Two slide assemblies 46 are provided which are identical to one another, although only the upper assembly is depicted at FIG. 4.
Because the present feeders 4 are normally operable in a cyclic fashion, neither one of the cartridge positions continuously functions as a supply or take-up cartridge. Rather, the positions alternate relative to component flow through the feeder assemblies 4. That is and as will become more apparent hereinafter, the tape direction alternates with each cycle. For example and as depicted at FIG. 3, as a filled tape moves from the upper "Supply" cartridge 9 to the lower, "Take-up" cartridge 9, during the first half of a cycle, the components are removed.
With the emptying of the upper cartridge 9, a tape leader and connector block are eventually extracted and positioned for subsequent operations to be described below. The lower cartridge 9 then contains the depleted tape and is removed. A full component cartridge 9 is then mounted to the lower cartridge position and spliced to the upper, now empty supply cartridge which becomes the take-up cartridge and the drive direction is reversed. Handling time of the populated and empty cartridges 9 is thus reduced. For certain applications, it may however be desired to provide a single direction parts flow, with attendant increased cartridge handling.
Returning attention to FIG. 1 and although the cartridges 9 can be manually maintained, FIG. 1 depicts an automatic cartridge server assembly 6. The server 6 includes a lead screw 10, which along with a pair of slide rails 11 supports a screw follower mounted slide carrier 12 and a pair of cartridge support trays 16. The server 6 may include duplicate arrangements of upper and lower cartridge trays 16 for achieving the necessary loading/unloading at each feeder station.
Control signals, which typically are of a pulse width modulated variety, are applied from the controller 32 to drive a stepper motor 50 coupled to the lead screw 6. The slide trays 16 are thereby appropriately aligned with the depleted and full cartridges 9. The empty tray is extended and retracted to remove an empty cartridge 9 and the other tray re-loads the feeder 4 with a full cartridge. Tray movement is controlled to insure that the cartridges 9 are locked to the housing 28 and a forward surface adjacent a cartridge accessing station 54 (reference FIG. 4).
Formed within the upper and lower surfaces of the housing 28, adjacent the slide rails 46, are pairs of adjacent slots or apertures 58 and through which frictional drive wheels 60 extend. The drive wheels 60 are biased a sufficient height to extend interiorly of the cartridges 9 at matching cartridge apertures 62 to contact and rotate the peripheral surfaces of a tape reel 68 mounted within each cartridge 9, reference FIG. 3. The drive wheels 60 are driven via a drive assembly 70 and reel drive motor M2 (reference FIG. 25).
A dual drive assembly 70 is particularly provided which can be resiliently biased up or down to appropriately drive the tape of the upper or lower cartridge 9, until a sprocket tape drive assembly 72 captures the tape. This occurs in a region slightly forward of the cartridges 9 and will be described in greater detail below.
Mounted forward of the reel drive assembly 70, adjacent the forward face of each cartridge 9 are upper and lower cartridge access or tape splicing stations 54. The splicing stations are identical to each other. Each includes a cartridge door opening assembly 76 and a splicing assembly 78. The specific constructional details of the assemblies 76 and 78 can be seen upon reference to FIGS. 5 and 6.
Each door opener assembly provides a projecting lug 80 which mates with an aperture 82 formed in a spring loaded cartridge slide door 84. The lug 80 is vertically operable via an associated solenoid and pneumatic or hydraulic directed piston 86 to raise and lower the slide door 84 in response to signals from the controller 32. The lower edge of the door 84 is thereby released from a groove 88 formed within a surface of a female coupler or splice block 90. The splice block 90 is attached to the leading end of a tape leader 92 secured to the internal tape reel 68. More of the details of the construction of each cartridge 9, tape leader 92 and splice blocks 90 can be seen upon reference to FIGS. 6, 7, 16 and 17.
Referring to FIG. 6 and with the release of the door 84 from the block 90, the tape leader 92 is advanced to the splicing assembly 78 via a threader assembly 98. Actuation of a pair of opposed threader cylinders 99 extends and retracts the splicing assembly causing it to move to and fro along paired sets of guide rods 79. A vertical control cylinder 74 causes a pair of pins 94 to grasp the block 90 and contract a pair of spring biased fingers 102. Subsequent actuation the cylinders 99 aligns and directs the tape leader 92 along lateral edge guides which rise from the surface of the housing 28 to loosely constrain and confine the leader travel, without allowing the leader to buckle. A male splice block 100 is concurrently restrained adjacent the splicing assembly 78 from the previous full cartridge 9, which now comprises the take-up cartridge.
The advancement of the female connector block 90 via the cylinders 99 causes the connector and splice blocks 90 and 100 to couple. That is, the fingers 102 of the male splice block 100, which include tapered fore-ends 104 and a flange 106, are inserted within the mating longitudinal aperture 108 of the female splice block 90. With a subsequent removal of the pins 94, the fingers 102 expand to cause the flanges 106 to couple one block to the other. The splicing assembly 78 is then released from the coupled blocks 90, 100.
During an uncoupling operation, the pins 94 contract the fingers 102 to release the splice blocks from one another. The pin carriage is then retracted to separate the blocks. During initial threading, the actuation of the cylinders 99 also advances the tape carrier 92 onto the tape drive assembly 72.
With the release of the splice blocks 90, 100, the reel drive 70 is engaged to the depleted cartridge to induce the leader 92 to be taken up into the cartridge 9. The cartridge 9 can then be removed and replaced with a new cartridge 9. The male splice block 100 meanwhile is restrained at the splice station 78 and to the sprocket tape drive 72. The slide door 84 of the new cartridge is next retracted and the tape leader 92 is advanced by the reel drive 70 to achieve coupling. As the feeder operation cycles, the cartridge take-up and supply positions alternate, however, the positions of the male and female splice blocks remain constant relative to the splice station 78. Once the tape ends are coupled (reference FIG. 7), the sprocket tape drive assembly 72, which is contained within the housing 28 forward of the splicing assembly 74, determines subsequent movement of the tape 110.
With reference to FIGS. 8 and 8a, the tape drive assembly generally comprises a pair of endless, metal drive bands 112 which include a plurality of dual purpose, drive lugs 113 and drive pins 114. The pins 114 mate with apertures 115 let into the lateral edges of the tape 110. The drive bands 112 are wound about and in frictional contact with three pairs of drive wheels 116, 118 and 120. The drive wheels 116 contain recesses which mate with the drive lugs 113 and are driven via a notched belt 122, pulley 124 and stepper motor 126. The other pairs of wheels 118 and 120 act as idler wheels and are free spinning with the bands 112. Slippage is thereby minimized at any of the drive wheels 116, 118 or 120, which slippage could translate at the control circuitry into component misalignment (either real or apparent) relative to the splicing assembly 74, cover removal assembly 130 and lift and locate assembly 132.
In the event of a condition wherein the parts tape 110 binds or is otherwise placed under undue stress, the bands 112 can slip relative to the tape 110 or stepper motor 126 to prevent breaking the tape carrier. The amount of slippage is dependent upon drive band tension, which is adjustable at a tensioner assembly.
Slippage induces an alarm condition and, depending upon the amount of slippage, can be automatically corrected by the controller 32. Alternatively, should the tape 110 become disengaged from the drive bands 112, the loss of tension causes the controller 32 to stop drive power and annunciate an appropriate operator alarm.
From the splicing assembly 74, the tape 110 is advanced past the cover removal assembly 130 to the lift and locate station or assembly 132. With reference to FIG. 9, a detailed perspective drawing is shown of the assembly 130 which extends above the housing 28 and the path of the tape carrier 110, forward of the splicing assembly 78. The principal operation performed by the assembly 130 is to remove the Faraday cage or cover 134 (reference FIG. 7) from each of the plurality of storage sites or component compartments 135 located on the tape carrier 110.
The cover removal assembly 130 includes an extractor head 140. The extractor head 140 is capable of vertical and longitudinal movement via a pair of fluid controlled cylinders. A cylinder 131 mounted beneath the cover 139 (reference FIG. 3) controls longitudinal movement and a cylinder 143 secured to the head 140 controls vertical movement of the head 140.
Cover removal is particularly effected upon directing each component compartment into alignment with the lift and locate assembly 132. The extractor head 140 is then extended and vertically lowered with sequential control of the cylinders 131, 143 such that a number of contained fingers 142 are projected through mating apertures 144 of the cover 134. As the fingers 142 are lowered, they flex the cover 134 to disengage the cover from mating tabs formed into the sidewalls of a raised ring that projects from the tape 110 (reference FIG. 17) to release the cover 134 from the tape 110. Upon release, the fingers 142 support the cover 134, which is then vertically retracted and cleared to one side, away from further operations. The component storage compartment 135 is then accessed to either fill the compartment 135 or extract contained parts. Cover reattachment is effected in a reverse order, upon realigning each cover to an uncovered storage location.
Subsequent to removing and retracting each cover 134, the edges of a component support pallet 146 are clamped with a pallet clamping assembly 136, reference FIG. 10. The associated lift and locate assembly 132 is then engaged to support the bottom of the pallet and test components contained on the pallet, if desired. FIGS. 11 and 12 depict test fixtures 137 and 138 which contain electrical and/or pneumatic and fluid connectors which permit cursory electrical and mechanical integrity tests of each component. Varieties of other fixtures can be used, which either attach to the assembly 132 or to the tool head 33 to test the upper surfaces of each component. Appropriate temporary contacts/connections are thus made during testing without removing the component to confirm integrity. Depending upon test results, necessary actions can be taken replace the defective component or pass over the component.
The clamping assembly 136 includes a pair of clamps 152 which are mounted to rotate in response to the extension and retraction of a pair of cylinders 154 mounted to each side of the tape 110. As the pallet 146 is clamped, the lift and locate assembly 132 is actuated to raise a pallet support platform 133 (reference FIGS. 11 and 12). A number of pins 139 project from the platform to engage apertures 156 formed in the outer periphery of the component pallet. The pallet 146 is thereby securely constrained between the pins 139 and clamps 152. As significant, the pallet 146 is restrained to a known reference location and relative to which the previously mentioned robotic arm 24 or the gantry mounted, multi-faceted tool head assembly 33 can access the contained components. The components can also be simultaneously tested at the fixtures 137 as they are loaded or removed.
Returning attention to FIG. 3 and with additional attention to FIGS. 13 and 14, general and detailed views are shown of the gantry assembly 26 which supports the multi-faceted tool head assembly 33. The tool head assembly 33 contains a number of tool heads which typically contain pick-and-place fingers 164. The fingers 164 are secured to a gripper assembly 165 that determines finger movement. Each gripper 165, in turn, is secured to the tool head 33 via a coupler assembly 166.
The tool head assembly 33 is supported to the gantry 26 at a pair of driven lead screws 168 and 170. The assembly 33 is horizontally extensible via a servo-motor 169 and the screw 170 between each supported pallet 146 and the transversely mounted component containing conveyor 8 or work station 9. Otherwise, the assembly 33 is vertically extensible via a servo-motor 173 and the screw 168.
The lead screw 170 is particularly coupled to a carrier 171 that supports the lead screw 168 and servo-motor 173. The servo-motor 169 controls the position of the carrier 171 along the lead screw 170. The operation of the servo-motor 173, in turn, extends and retracts the pick-and-place fingers 164. The gripper assembly 165 causes the fingers 164 to appropriately contract or expand relative to the components. The particular tool head brought to bear and the force applied to grasp/release each component are determined by the controller 32 via control couplings to the tool head assembly 33.
A variety of tool heads, containing various facets and configurations of tools which mate with the components being accessed can be stored to one side of the housing 28. A three position, multi-faceted tool head 180 is particularly shown at FIG. 14. Alternatively, a single facet tool head may be respectively depict four and five position tool heads 181 and 182.
The detailed construction of the tool head assembly 33 is depicted in FIGS. 14, 15a-c and 15f. With attention first directed to FIG. 14, the head assembly 33 includes a coupler assembly 166. The coupler assembly 166 provides a flanged collar 174 which projects from a platform of the carrier 171 at FIG. 3 and mates with an automatic tool coupler 176. The coupler 176 includes pneumatically operated fingers 177 which couple to a tool changer plate 179. A threaded collar and nut (not shown), which is captured to the collar 174, secures the coupler 176 to the collar 174.
A number of modular blocks 178 and 262, which contain pneumatic and electrical terminations, are also detachably mounted to the coupler 176 and plate 179. Appropriate conduits or wires mount between the ports of the blocks 178 or terminal strips of the blocks 262 to define the operation of the tool head. The specific control signals are determined by the microprocessor controller 44.
Flexible strip circuits may extend from the block 262 along appropriate surfaces of the head 180 to further points of connection with other flexible conductors that couple to the gripper 165 and tools 192. The circuits may comprise discrete assemblies or conductive zones or bands formed into or on the head 180. The circuits may couple to one another with a wiping action at junctions at each separately moveable assembly.
FIGS. 15a and 15b depict more of the details of the coupler assembly 176 and tool plate 179. These include a pneumatic cylinder 250 which extends from a linkage plate 252 that contains the fingers 177, reference FIG. 15a. The cylinder 250 actuates the fingers 177 which, in turn, couple and align with mating pins 254 in the tool plate 179. The coupler 176 and plate 179 are further aligned to each other at mating radial locating rings 256, 258, such as O'rings, and axial locating slots 260 and mating pins (not shown) which extend from the coupler 176. Terminal strips on the upper and lower faces of the blocks are thereby able to engage each other.
FIG. 15b depicts an electrical connector 263 having upper and lower terminal strips 264, 266 which couple to strips provided at the back vertical surface of each block 262. The connector 263 finds use for coupling high current signals to the electrical termination blocks 262 of the tool coupler 176 and plate 179. The block 263 exhibits a low coupling force and high current carrying capability via a linkage 268 that actuates articulating connector arms 270, 272 to close around a stationary arm 274 when the tool coupler 176 and plate 179 are coupled together. The arms 272 and 274 contain multiple conductive bands 276 that when brought into contact with each other create a circuit having high current capability.
Returning attention to the tool head assembly 180 of FIG. 14 and also to FIG. 15c, the tool head assembly 180 provides a rotationally mounted multi-faceted, turret or gripper head 190 which supports various distinct grippers 165 and tools 192 at each of the facets 280. The head 190 may include any number of facets 280 and one or more of the facets 280 may be used for the same or different operations. As necessary, ones of the facets 280 may also not be populated with tools.
A desired facet 280 can be rotated to position via a stepper motor 282 which indexes the facets 280 in relation to a piston or pin position lock 284. The lock 284 mates with radial locating holes 286 to precisely define each tool position. The motor 282 couples to a geared strip or rack 288 that extends from a counterbalance plate 290. The plate 290 reduces the inertia to rotate the facets 280 and tools, and generally balances the load at the head 180. The facets 280 are modular and are individually secured to the head 180 at mounting projections 292.
Associated photo optic sensors 293 are mounted about the head 190 to monitor head movement and provide corresponding control signals to the micro controller 42
Particularly, secured to each facet of the head 190 is a so called "penny gripper" assembly 165. Grippers of this type find wide application with most components and support the pick-and-place fingers 164 which are mounted to expand and contract under appropriate control signals to the gripper 165.
One gripper assembly 165 is depicted in detail at FIG. 15f. The gripper 165 is configured about a pneumatic piston 294 which determines the gripping motion. A pin 296 extends from the piston 294 and translates vertical piston motion to a horizontal opposing motion of the finger bases 298 via elongated slots 300, 302 let into each finger base 298. The slots 300 are inclined at an angle less than 35 degrees from the longitudinal axis of the piston. Two additional horizontal slots 302 and intermediate needle bearings 304 independently, horizontally direct each finger base 298. The finger bases 298 are preloaded under spring tension for accuracy with spring washers 306. The lower end of each finger base 298 defines a tooling face 308 whereto the fingers 164 are attached. Sensors, such as photo optic couplers, are also mounted to the gripper 165 to monitor and further control the motion of the finger bases. Electrical connections to such sensors are facilitated through the flexible circuitry and conductive bands discussed above.
FIG. 15g depicts an alternative gripper assembly 310. The finger bases 298 of the assembly 310 are supported by upper and lower ball bearing supports 312. Two of the supports 312 are depicted, although four are provided at each gripper 310. The supports 312 are contained to the finger bases within ballways 313, behind covers 314. The covers 314 are secured to the finger base 298 with fasteners 316. Each finger base 298, in turn, is retained to the body 318 of the gripper via covers 320 and fasteners 322. Finger base motion is limited by the retention of a slide piece 323 between the covers 320.
Each ball bearing support 312 includes a number of bearings 324 which project through a carrier 326 and roll along pairs of upper and lower rails 328. A spring plate 330 mounts beneath the lower pair of rails 328 and cooperates with a tensioner screw 332 to establish the slide force of the supports 312.
Finger base motion is controlled via the cooperation of the pin 296 with a slot 333 that is formed into a block 336. The block 336 mounts within a cavity of each finger base 298. The supports 312 have been found to provide an improved and more durable freedom of movement to the finger bases 298. They particularly require less adjustment than the assembly of FIG. 15f and are more economical to manufacture and assemble.
It is to be appreciated that the particular shape, finger spacing and other details of the tool heads 192 will depend upon the particular types of components being accessed and their mounting relation to the pallet 146 and/or one another on the pallet 146. Thus, the present tool head assembly 33 is intended to accommodate a variety of tool heads which, in turn, are reconfigurable in various constructions.
Returning attention to the details of the tape 110 and cartridges 48, FIG. 16 depicts an exploded assembly drawing of a typical tape cartridge 9. Each cartridge is generally comprised of an external folded shell or housing 200. The housing 200 is typically formed of a plastic material that is folded to shape and appropriately secured to create a durable five sided outer shell. The lower, open end and corner of an adjacent side receive a formed metal extrusion assembly 202 which is bonded to the shell 200 at the edges 201, 203. The portion of the extrusion 202 mounted to the short edge 203 contains the mentioned spring biased and apertured shutter door 84. The bottom surface of the extrusion 202 contains a rail portion 56 which mates with the housing slide track 46.
Positioned internally of the outer shell 200 is a second folded sheet goods liner 204 which supports a bushing or axle 206 containing end bearing surfaces and the tape reel 68. In combination, the outer shell and liners 200, 204 form a relatively rigid protective casing about the center mounted reel 68, tape 110 and contained components.
The tape reel 68 is formed in two halves 205, 207 and each of which supports a cylindrical piece 208a and 208b. The pieces 208a and 208b mate with each other to form the bushing 206. Each core portion extends from the inner surface of one of the reel halves 205, 207. A pair of screw fasteners 209 and washers 211 mount to the bushing 206 to secure the halves 205, 207 to one another and to the liner 204 in a fashion which permits rotation of the reel 68 within the liner. The reel 68, otherwise, is of conventional construction.
The peripheral edges 214 of the reel 68 are widened to provide frictional drive surfaces relative to the drive wheels 60 which extend from the housing 28. Secured to the axle 206 is a tape leader 92 which is formed of a length of material similar to that used to form the tape substrate. It is sufficiently long to permit extension to the splice station 74 and terminates with a male splice block 90. Alternatively, a female splice block may be secured to the leader 92.
FIG. 17 depicts an exploded perspective drawing of a single component storage location 135 of the component tape 110. A conventional dual-in-line (DIP) integrated circuit 215, including opposite edge mounted parallel rows of pin connector terminals is specifically shown in relation thereto. A raised platform 230 extends from the pallet 146 to elevate and support the body of the component 215 and permit room for the gripper fingers 164 to grip the component. A complementary depression 232 is formed in the top of the cover 134 such that the component 215 is constrained between the two formed regions 230, 232 and vertical movement prevented.
The periphery of the pallet 146 and cover 134 are formed to a standardized size and shape relative to a raised annular ring 234 of the carrier tape 110. The pallet 146 interlocks with the sidewalls 234 at four tapered projections 236. Orthogonal flanges 158, otherwise, project inward in the space between each tapered projection 236. A gap or space 238 is provided between the bottom of the flanges 158 and the top of the projections 236 to retain the pallet 146. Each pallet 146 is fitted into the annular ring 234 by positioning each pallet 146 beneath the ring 234 and raising the pallet. The pallet 146 flexes the projections 236 as it is raised along the sidewalls 234, and the projections 236, expand beneath the pallet 146, which is restrained, to partially fill the upper gap 238.
Each cover 134, in turn, includes tapered projections 240 which align with the recess formed by each tapered sidewall projection 236. Upon lowering a cover 134 over an annular storage location 148, the cover walls flex until the projections 240 pass the pallet 146, when the cover walls re-expand to secure the cover 134 to the pallet 146. The cover 134 is thereby constrained to the pallet 146 which, in turn, is constrained beneath the upper flange 158.
Cover removal is effected at each storage location 148 via the plurality of fingers 142 which project from the cover removal assembly 130 to engage the cover in the region of the four cover recesses 240. Once the fingers 142 are lowered and engaged, the lift solenoid 138 is actuated which causes the fingers 142 to remove the cover 134. The peripheral edges of the pallet 146 flex slightly to permit release, although the dimensional tolerances are typically adjusted to permit minimal flexing. Over time, it may periodically be necessary to recondition a tape 110 by replacing worn or broken pallets 146 or covers 134. Under normal conditions and the typical flexing stresses that are encountered, it is anticipated that each tape 110 can be used in excess of twenty-five times. Depending upon the quality of materials, this reusability can be further enhanced.
In passing it is also to be appreciated that the lift and locate assembly 132 (reference FIG. 10) includes associated sensors shown at FIG. 25 which provide feedback information to the controller 30 and pick-and-place assembly 33 whereby empty storage locations 148 and/or empty component positions on a pallet 146 are detected and avoided. Extraneous equipment movement is thereby minimized.
Appreciating the varieties of odd component shapes which exist in typical PCB fabrication processes, the present tape carrier 110 is configured to accommodate a broad selection of component shapes and types. FIGS. 18 to 24 show a variety of perspective drawings of tape segments wherein the component pallets 146 and covers 134 are variously formed to accommodate some of these components. FIGS. 17 and 18 show an arrangement for supporting conventional DIP packages. FIG. 19 discloses an arrangement wherein the component pallet 146 includes resilient arcuate fingers 216 which project from the pallet surface to compressively restrain a component, such as a crystal oscillator, between the fingers 216. FIG. 20 shows a pallet 146 including a thermoformed projection 218 which is used to orient a component 220. FIG. 21 shows still another pallet 146 which includes a plurality of spaced projections 222. Thick film hybrid assemblies 224 or the like are contained between rows of the projections 222.
FIG. 22 shows another component pallet which also accomodates a nested edge mounting of the components. The elevated portion of the pallet surface particularly provides a plurality of cavities 226 which conform to and nest each component. A finger access channel 227 extends the width of the elevated platform and provides space to accommodate the gripper fingers.
FIGS. 23 and 24 disclose pallets containing flat pack receiving cavities 228. Such components contain conductors on all four edges. Apertures 242 are provided in each pallet to permit access by the grippers 164, to support the lead wire terminations and permit contact thereto for testing. Additional apertures may be provided to support still other test fixtures. The pallet of FIG. 24 also provides a plurality of combed projections 232 which separate the adjacent lead wires. The combination of the cavities 228, projections 244, and cover 134 passively restrain and fully enclose each component.
Optionally, each pallet can include a compliant corner projection 245 to separately restrain each component to the cavity 228. When included, a cover 134 is not required. In such circumstances, the fingers 164 are constructed to expand and release the projections.
Depending upon the particular component mounting, the pick- and-place assembly 33 or robotic arm 24 is positionally programmed relative to the precise position of the lift and locate assembly 132 and a pallet 146 and component supported thereat. The position is particularly established to a tolerance of plus/minus 0.0004 inch. Such a tolerance has heretofore not been achievable, except possibly for some large volume, uniform component packaging systems. Such a positional accuracy and the elevated arrangement of the pallets enables the associated handler assemblies to not only locate singular components positioned on the pallets, but also to select one of a number of components mounted on a pallet, such as in the constructions of FIGS. 21 and 22.
A further advantage of the present tape carrier 110 is that each feeder station 4 is essentially waste free. That is and in contrast to other known tape component carrier systems, a separate collection mechanism must be provided for spent binding tape or covers. While in some cases the binder tape may be re-utilized, this requires a re-weaving of the tape relative to the component loading operation which in turn requires special equipment. The present feeder achieves both functions within a singular assembly.
While the foregoing invention has been described with respect to its presently preferred construction, along with various considered modifications and improvements thereto, it is to be appreciated that still other modifications may suggest themselves to those of skill in the art. Accordingly, the invention should not be narrowly interpreted. Rather, the invention should be interpreted to include all those equivalent embodiments within the spirit and scope of the following claims.
|
A micro-component feeder assembly supporting small, odd lot or odd shaped components and subassemblies from a sprocket driven tape carrier including seriatim, annular housings having removeable covers and component pallets. The housing walls include fastener portions which support each pallet and cover. One or more components are indexed to pallet apertures, cavities, projections or resilient restraints. Wound tape supply and take-up cartridges mount to a controlled drive housing which includes tape reel drive, tape splice, tape sprocket drive, cover removal, clamp/test and lift and locate assemblies. Full and depleted component tapes cyclically alternate between upper and lower cartridges. A multi-faceted tool head assembly is controlled to a defined pallet presentation and defined component positions at each pallet. A gripper assembly produces a uniform gripping and insertion action of each component. In a multi-feeder system, a cartridge server assembly maintains a continuous supply of full component cartridges. A robotic arm may be used to pick-and-place components to and from a tape at a supply conveyor or work station.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device including a semiconductor circuit constituted of a thin-film transistor (hereinafter, abbreviated as a TFT) and a manufacturing method thereof. More particularly, the present invention relates to an electro-optical device as represented by a liquid crystal display panel and an electronic device including such an electro-optical device as a constituent.
Throughout the specification, the term “semiconductor device” indicates all devices that utilize the semiconductor characteristics to function; electro-optical devices (hereinafter, referred to as display devices), semiconductor circuits and electronic devices are all included in the category of the semiconductor devices.
2. Description of the Related Art
Recently, there has been developed a technique for manufacturing a TFT by using a thin semiconductor film (with a thickness of about hundreds to thousands of nm) formed on a substrate which has an insulating surface. The TFT is widely applied to semiconductor devices such as an integrated circuit (IC) or an electro-optical device, and is urgently expected to be developed as, in particular, a switching element for a display device or the like.
An active-matrix liquid crystal display device is frequently used as a semiconductor device because images with high definition can be obtained as compared with a passive liquid crystal display device. The active-matrix liquid crystal display device includes: a gate wiring; a source wiring; a TFT in a pixel portion, which is provided at the cross point of the gate wiring and the source wiring; and a pixel electrode connected to the TFT in the pixel portion.
An amorphous silicon film is used as an amorphous semiconductor film for a conventional TFT because the amorphous silicon film can be formed on a large substrate at a low temperature of 300° C. or less. An inverse-stagger type TFT having a channel formation region formed of an amorphous semiconductor film is widely used.
Conventionally, a TFT is formed on a substrate by using five or more photomasks through a photolithography technique in an active-matrix electric device. The reduction of the number of manufacturing steps is believed to be effective to improve the productivity and the yield.
For the reduction of the number of manufacturing steps, it is necessary to reduce the number of photomasks used in the manufacture of the TFT. With the use of one photomask, the steps of resist application, prebaking, exposure, development, postbaking and the like, the preceding and following steps of forming a coating film, etching and the like, and, furthermore, the step of resist removal, washing and drying, are inevitably added to complicate the manufacture of the TFT.
SUMMARY OF THE INVENTION
The present invention has been made to cope with the above problem, and has an object of reducing the number of photomasks used for manufacturing a TFT in an active-matrix liquid crystal display device so as to realize the improvement in productivity and yield.
Moreover, the present invention has another object of solving a problem of poor coverage of a pixel electrode at the end of a pixel TFT, which generally occurs with the reduction of the number of photomasks, and of providing a structure for preventing an insulating film from being etched during the etching of an amorphous semiconductor film and a manufacturing method thereof.
The present invention is characterized in that the manufacturing steps from the step of forming a conductive film for forming a gate wiring and a capacitance wiring and a terminal electrode to the step of forming a pixel electrode are carried out with three photomasks so as to solve the problem of poor coverage of a pixel electrode and to prevent an insulating film from being etched during the etching of an amorphous semiconductor film.
The three photomasks are respectively characterized as follows:
the first photomask is for forming a conductive film; the second photomask is for forming a first amorphous semiconductor film and a second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type); and the third photomask is for forming a pixel electrode, a source region, a drain region, a source electrode and a drain electrode, and for channel etching.
According to a constitution of a manufacturing method disclosed in the present specification, a method of manufacturing a semiconductor device comprising:
a first step of forming a gate wiring over an insulating surface;
a second step of forming an insulating film covering said insulating surface and said gate wiring;
a third step of forming a first amorphous semiconductor film over the insulating film;
a fourth step of forming a second amorphous semiconductor film containing an impurity element of one conductivity type over the first amorphous semiconductor film;
a fifth step of forming a conductive film comprising a metallic material over the second amorphous semiconductor film;
a sixth step of forming an side edge of the first amorphous semiconductor film into a taper shape by etching the first amorphous semiconductor film and the second amorphous semiconductor film and the conductive film;
a seventh step of forming a transparent conductive film over the conductive film;
an eighth step of etching a part of the first amorphous semiconductor film and the second amorphous semiconductor film and the conductive film and the transparent conductive film to expose a part of the first amorphous semiconductor film and to form a pixel electrode formed from the transparent conductive film, a source wiring formed from the conductive film, source region and drain region formed from the second amorphous semiconductor film.
In the sixth step, the conductive film and the second amorphous semiconductor film and the first amorphous semiconductor film are etched by chlorine group gas.
A TFT manufactured by utilizing the present invention is shown in FIG. 15 . In the present invention, the ends of a first amorphous semiconductor film 1001 are tapered so as to improve the coverage. In order to taper the ends of the first amorphous semiconductor film 1001 , by etching the first amorphous semiconductor film 1001 using an etching gas of chlorine group while etching the metallic layer 1002 a to form source electrode and drain electrode (and the second amorphous semiconductor film 1002 b for forming source region and drain region), only side edges of the first amorphous semiconductor film 1001 can be formed into taper shape. Ultimately, an inverse-stagger TFT in which coverage defect of a pixel electrode 1003 has been solved can be manufactured with three photomasks in total. Moreover, when the amorphous semiconductor film is to be etched, it is possible to prevent an insulating film 1004 from etching in the vicinity of the ends of the first amorphous semiconductor film 1001 .
In this way, in the present invention, a multilayer film (metal film, second amorphous semiconductor film and first amorphous semiconductor film) comprising a plurality of different materials is etched at a time using the same etching gas (chlorine group) with a second photomask to improve throughput.
Herein, a tapered shape angle (taper angle) of the first amorphous semiconductor film 1001 is defined as an angle formed by the surface of a substrate and an inclined portion of the end of the first amorphous semiconductor film ( FIG. 21B ). As shown in FIG. 21A , a taper angle of the end of the first amorphous semiconductor film can be controlled to fall within the range of 5 to 45 degrees by appropriately selecting the etching conditions.
A chlorine type etching gas is used as an etching gas for carrying out the present invention. For example, a gas selected from the group consisting of Cl 2 , BCl 3 , HCl and SiCl 4 , or a mixed gas of a plurality of gases selected from the above group, can be used as an etching gas.
Because the chlorine type gas has little difference between etching rate to the metal layer 1002 a and the etching rate to the second amorphous semiconductor film 1002 b , their side edges are almost made aligned. A chlorine type etching gas has different etching rates for the first amorphous semiconductor film and a second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type). Since the etching rate for the second amorphous semiconductor is higher than that for the first amorphous semiconductor film, the ends of the first amorphous semiconductor film can be formed in a tapered shape.
In one constitution of the present invention shown in FIG. 15 , a semiconductor device comprises a gate wiring over an insulating surface, an insulating film over the gate wiring, a first amorphous semiconductor film over the insulating film, a source region and a drain region provided in a second amorphous semiconductor film containing an impurity element of one conductivity type over the first amorphous semiconductor film, a source wiring or electrode over the source region or the drain region, and a pixel electrode overlapping and in contact with a part of the electrode, wherein a side edge of the first amorphous semiconductor film is tapered.
In FIG. 15 , the side edge of the second amorphous semiconductor film 1002 b (source region or drain region) containing an impurity element of one conductivity type (n-type or p-type) is formed almost perpendicularly to the substrate, that is, in alignment with the side edge of the metal layer 1002 a (source electrode and drain electrode). However, side edge of the second amorphous semiconductor film 1002 b containing the impurity element of one conductivity type (n-type or p-type) or side edge of the metal layer 1002 a may be etched into a taper shape.
In other constitution of the present invention, a semiconductor device comprises a gate wiring over an insulating surface, an insulating film over the gate wiring, a first semiconductor film over the insulating film, a source region and a drain region provided in a second amorphous semiconductor film containing an impurity element of one conductivity type over the first amorphous semiconductor film, a source wiring or electrode over the source region and the drain region, and a pixel electrode overlapping with and being in contact with a part of the electrode, wherein a side edge of the first amorphous semiconductor film and a side edge of the second amorphous semiconductor film are tapered.
It is to be noted that in the case where the side edge of the second amorphous semiconductor film 1002 b or the side edge of the metal layer 1002 a are tapered, they have a taper angle larger than that of the first amorphous semiconductor film.
Further, a dry etching apparatus used in the present invention may be an etching apparatus of RIE or an etching apparatus of ICP. It is to be noted that because a taper angle can be controlled by controlling electric power, the etching apparatus of ICP is preferable.
An etching experiment was conducted. After an insulating film (silicon oxide film) and a first amorphous semiconductor film (amorphous silicon film) and a second amorphous semiconductor film (phosphorus doped silicon film) and Al-Si film (aluminum film containing 2 wt % silicon) were laminated in order, they were selectively covered with a resist and they were etched using a mixture gas of Cl 2 and BCl 3 in fact. The cross-sectional view after that was observed and is shown in FIG. 19 . In FIG. 19 , SEM (Scanning Electron Microscope) photograph is shown and its magnification is fifty thousands times. By conducting the etching with the mixture gas of Cl 2 and BCl 3 , the Al—Si film and the second amorphous semiconductor film and the first amorphous semiconductor film can be etched at the same time, and further, only the side edge of the first amorphous semiconductor film can be tapered.
Further, it is possible to use other metal materials in place of the Al—Si film. In that case, it is necessary to select etching condition, typically etching gas. For example, in the case where Ta film (tantalum film) is used as the metal film 1002 a , by etching the first amorphous semiconductor film (amorphous silicon film) and the second amorphous semiconductor film (phosphorus doped silicon) and the Ta film, only the first amorphous semiconductor film can be tapered.
Further, in the case where a multi-layer of Tan and Ta is used as the metal film 1002 a , by using a mixture gas of Cl 2 (gas flow rate of 40 sccm) and CF 4 (gas flow rate of 40 sccm as etching gas, the first amorphous semiconductor film (amorphous silicon film) and the second amorphous semiconductor film (phosphorus doped silicon film) and the multi-layer film of Tan and Ta are etched and only the first amorphous semiconductor film can be tapered.
Further, in the case where W (tungsten) film is used as the metal layer 1002 a , by using a mixture gas of Cl 2 (gas flow rate of 25 sccm) and CF 4 (gas flow rate of 25 sccm) and O 2 (gas flow rate of 10 sccm) or a mixture gas of Cl 2 (gas flow rate of 12 sccm) and SF 6 (gas flow rate of 6 sccm) and O 2 (gas flow rate of 12 sccm) as an etching gas, the firs amorphous semiconductor film (amorphous silicon film) and the second amorphous semiconductor film (phosphorus doped silicon film) and the W film are etched, and the first amorphous semiconductor film can be tapered similarly.
Further, in the case where Ti (titanium) film is used as the metal layer 1002 a , by using a mixture gas of Cl 2 and BCl 3 as an etching gas, the first amorphous semiconductor film (amorphous silicon film) and the second amorphous semiconductor film (phosphorus doped silicon film) and Ti film are etched, and only the first amorphous semiconductor film can be tapered.
Further, in FIG. 15 , when formed into an island shape by etching using the second photomask, the side edge of the first amorphous semiconductor film is tapered, as illustrated above. However, as shown in FIG. 23 , the present invention can be applied to a step (channel etching) of removing a part of the first amorphous semiconductor film 2001 overlapping with the gate electrode 2000 through an insulating film. By using a third photomask and using an etching gas of chlorine type similarly, the metal layer 2002 a and the second amorphous semiconductor film 2002 b and the first amorphous semiconductor film 2001 are etched and only the first amorphous semiconductor film 2001 can be tapered so that a protective film (passivation film) is formed with favorable coverage at a later step. It is to be noted that reference numeral 2003 designates a pixel electrode and the reference numeral 2004 designates a gate insulating film.
Further, in the eighth step of the constitution of the above manufacturing method, a part of the first amorphous semiconductor film and the conductive film and the second amorphous semiconductor film are etched with a chlorine type gas.
Further, according to the constitution shown in FIG. 23 according to one of the present invention, a semiconductor device comprises a gate wiring over an insulating surface, a gate insulating film over the gate wiring, an amorphous semiconductor film over the gate insulating film, a source region and a drain region over the amorphous semiconductor film, a source wiring or electrode over the source region and the drain region, and a pixel electrode overlapping with and in contact with a part of the electrode wherein a region of the amorphous semiconductor film overlapping with the gate wiring with the gate insulating film therebetween and not overlapping with the source region and the drain region has a thickness thinner than the other region and is tapered to become thin toward the center thereof.
Further, in the above constitution, the region having the taper shape has an angle in the range of 5° to 45°.
Further, in the above constitution, the side edge of the first amorphous semiconductor film may be tapered with an angle in the range of 5° to 45°.
On the other hand, as a comparative example, FIG. 16 shows a TFT including a first amorphous semiconductor film and a second amorphous semiconductor film, each having the ends that are etched to be perpendicular to the substrate. The amorphous semiconductor films 1005 and 1006 b are etched separately from the etching of the metal layer 1006 a . After the metal layer 1006 a is selectively wet etched, a first amorphous semiconductor film 1005 and a second amorphous semiconductor film 1006 containing an impurity element with one conductivity type (n-type or p-type) of the TFT are dry etched with a mixed gas of CF 4 and O 2 using the metal layer as a mask. The first amorphous semiconductor film 1005 and the second amorphous semiconductor film 1006 containing an impurity element with one conductivity type (n-type or p-type) are simultaneously etched. As a result, the shapes of the ends of the first amorphous semiconductor film 1005 and the second amorphous semiconductor film 1006 containing an impurity element with one conductivity type (n-type or p-type) is formed to be perpendicular to the substrate in the almost same shape as each other as shown in FIG. 16 . Then, a pixel electrode 1007 is formed on these films 1005 and 1006 . In the respective etchings in the comparative example, a side etching (an undercut) is produced so that when a film is formed later, there is a fear that the film might be cut at a step.
In the above-described structure shown in FIG. 16 , poor coverage occurs at the ends of the first amorphous semiconductor film 1005 and the second amorphous semiconductor film 1006 containing an impurity element with one conductivity type (n-type or p-type) and the metal layer 1006 a . The poor coverage occurs to such a degree that the pixel electrode 1007 cannot be formed in a normal state due to a poor etching or due to a step shape of the three layers.
During the etching for manufacturing the above shape shown in FIG. 16 , an insulating film 1008 in the vicinity of the ends of the first amorphous semiconductor film 1005 is also etched to generate a variation of the insulating film in thickness.
The other structure of the present invention, which is different from the above-described structure, will be described below. In the present invention, the manufacturing steps from the formation of a conductive film to the formation of a pixel electrode are carried out with three photomasks so as to solve the problem of poor coverage of a pixel electrode.
The three photomasks are respectively characterized as follows:
the first photomask is for forming a conductive film; the second photomask is for forming an insulating film, a first amorphous semiconductor film, and a second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type); and the third photomask is for forming a pixel electrode, a source region, a drain region, a source electrode and a drain electrode, and for channel etching.
According to other constitution of manufacturing method shown in the present specification, a method for manufacturing a semiconductor device comprises:
a first step of forming a gate wiring over an insulating surface;
a second step of forming an insulating film covering the insulating surface and the gate wiring;
a third step of forming a first amorphous semiconductor film over the insulating film;
a fourth step of forming a second amorphous semiconductor film containing an impurity element of one conductivity type over the first amorphous semiconductor film;
a fifth step of forming a conductive film comprising a metallic material over the second amorphous semiconductor film;
a sixth step of etching the insulating film and the first amorphous semiconductor film and the second amorphous semiconductor film and the conductive film to taper a side edge of the first amorphous semiconductor film;
a seventh step of forming a transparent conductive film over the conductive film; and
an eighth step of etching a part of the first amorphous semiconductor film and the transparent conductive film and the conductive film and the second amorphous semiconductor film to expose a part of the first amorphous semiconductor film and to form a pixel electrode from the transparent conductive film and to form a source wiring from the conductive film and to form a source region and a drain region from the second amorphous semiconductor film.
A TFT manufactured by utilizing the present invention is shown in FIG. 17 . According to the present invention, the ends of a first amorphous semiconductor film 1801 are tapered so as to improve the coverage. In order to taper the ends of the first amorphous semiconductor film 1801 , an inverse-stagger TFT is manufactured with three photomasks by using a chlorine type etching gas. As a result, the ends of the first amorphous semiconductor film 1801 can be manufactured to have a tapered shape, thereby solving the problem of poor coverage of a pixel electrode 1803 .
Herein, a tapered shape angle (taper angle) of the first amorphous semiconductor film 1801 is defined as an angle formed by the surface of a substrate and an inclined portion of the end of the first amorphous semiconductor film 1801 ( FIG. 22B ). As shown in FIG. 22A , a taper angle of the end of the first amorphous semiconductor film can be controlled to fall within the range of 5 to 45 degrees by appropriately selecting the etching conditions.
A chlorine type etching gas is used as an etching gas for carrying out the present invention. For example, a gas selected from the group consisting of Cl 2 , BCl 3 , HCl and SiCl 4 , or a mixed gas of a plurality of gases selected from the above group, can be used as an etching gas.
Because a chlorine type gas has an etching rate to the metal layer 1802 a and an etching rate to the second amorphous semiconductor film with a little difference, their side edges are almost aligned with each other. However, a chlorine type gas has different etching rates for the first amorphous semiconductor film and a second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type). Since the etching rate for the second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type) is higher than that for the first amorphous semiconductor film, the ends of the first amorphous semiconductor film can be formed in a tapered shape.
According to the constitution of one of the present invention shown in FIG. 17 , a semiconductor device comprises a gate wiring over an insulating surface, an insulating film over the gate wiring, a first amorphous semiconductor film over the insulating film, a source region and a drain region provided in a second amorphous semiconductor film containing an impurity element of one conductivity type over the first amorphous semiconductor film, a source wiring or electrode over the source region or the drain region, and a pixel electrode overlapping with and in contact with a part of the electrode, wherein only a side edge of the first amorphous semiconductor film is tapered and is aligned with a side edge of the insulating film, and the side edge of the insulating film is not aligned with the source wiring or electrode.
In FIG. 17 , the ends of a metal layer 1802 a and a second amorphous semiconductor film 1802 containing an impurity element with one conductivity type (n-type or p-type) are formed so as to be perpendicular to the substrate. However, the ends of a metal layer 1802 a and a second amorphous semiconductor film 1802 containing an impurity element with one conductivity type (n-type or p-type) may alternatively be formed in a tapered shape.
An experiment of the etching was carried out. An insulating film and a first amorphous semiconductor film and a second amorphous semiconductor film and an Al—Si film (aluminum film containing 2 wt % silicon) are laminated over a substrate in order. Thereafter, they are selectively covered with a photoresist and actually etched using a mixed gas of Cl 2 and BCl 3 . A resultant cross-sectional view was observed and is shown in FIG. 20 . FIG. 20 is an SEM (scanning electron microscope) photograph taken at a magnifying power of 50000. By etching with a mixture gas of Cl 2 and BCl 3 , the Al—Si film and the second amorphous semiconductor film and the first amorphous semiconductor film can be etched at the same time so that only a side edge of the first amorphous semiconductor film can be tapered. Further, in FIG. 20 , the insulating film is removed using the first amorphous semiconductor film as a mask.
Further, in FIG. 17 , when formed into an island shape by etching using the second photomask, the side edge of the first amorphous semiconductor film is tapered. However, in a channel etch type TFT, the present invention can be applied a step (channel etching) of removing a part of the first amorphous semiconductor film overlapping with the gate electrode through the insulating layer. By using a third photomask and an etching gas of chlorine type similarly, the metal layer and the second amorphous semiconductor film and the first amorphous semiconductor film and the insulating film are etched, and only the first amorphous semiconductor film can be tapered so that in the case where a protective film (passivation film) is formed at a later step, a favorable coverage can be obtained.
On the other hand, as a comparative example, FIG. 18 shows a TFT including a first amorphous semiconductor film and a second amorphous semiconductor film, each having the ends that are etched to be perpendicular to the substrate. Etching of the metal layer 1902 a and etching of the amorphous semiconductor films 1901 and 1902 b are conducted separately from each other. After the metal layer 1902 a is selectively etched, a first amorphous semiconductor film 1901 and a second amorphous semiconductor film 1902 containing an impurity element with one conductivity type (n-type or p-type) of the TFT are etched with a mixed gas of CF 4 and O 2 . The first amorphous semiconductor film 1901 and the second amorphous semiconductor film 1902 containing an impurity element with one conductivity type (n-type or p-type) are simultaneously etched. As a result, the ends of the first amorphous semiconductor film 1901 and the second amorphous semiconductor film 1902 containing an impurity element with one conductivity type (n-type or p-type) are formed to be perpendicular to the substrate as shown in FIG. 18 . Then, a pixel electrode 1903 is formed on these films.
In the above-described structure, poor coverage occurs at the ends of the first amorphous semiconductor film 1901 and the second amorphous semiconductor film 1902 containing an impurity element with one conductivity type (n-type or p-type) and the metal film 1902 a and the insulating film 1904 . The poor coverage occurs to such a degree that the pixel electrode 1903 can not be formed in a normal state due to the thickness of the four films.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a top plan view showing a pixel;
FIGS. 2A to 2C are diagrams showing the steps of manufacturing a semiconductor device;
FIGS. 3A to 3C are diagrams showing the steps of manufacturing the semiconductor device;
FIGS. 4A and 4B are diagrams showing the steps of manufacturing the semiconductor device;
FIGS. 5A to 5C are diagrams showing the steps of manufacturing the semiconductor device;
FIGS. 6A to 6C are diagrams showing the steps of manufacturing the semiconductor device;
FIGS. 7A to 7C are diagrams showing the steps of manufacturing the semiconductor device;
FIG. 8 is a top plan view showing a pixel in Embodiment 3 of the present invention;
FIGS. 9A to 9C are diagrams showing the steps of manufacturing the semiconductor device;
FIGS. 10A to 10C are diagrams showing the steps of manufacturing the semiconductor device;
FIGS. 11A to 11C are diagrams showing the steps of manufacturing the semiconductor device;
FIGS. 12A and 12B are diagrams showing the steps of manufacturing the semiconductor device;
FIGS. 13A and 13B are diagrams showing the steps of manufacturing the semiconductor device;
FIGS. 14A to 14D are diagrams illustrating examples of apparatuses utilizing the semiconductor device;
FIG. 15 is a cross-sectional view showing a thin-film transistor manufactured by using the present invention;
FIG. 16 is a cross-sectional view showing a thin film transistor (comparative example);
FIG. 17 is a cross-sectional view showing another thin-film transistor according to the present invention;
FIG. 18 is a cross-sectional view showing another thin film transistor (comparative example);
FIG. 19 is a cross-sectional SEM showing a thin film transistor according to the present invention;
FIG. 20 is a cross-sectional SEM showing another thin film transistor according to the present invention;
FIGS. 21A and 21B are diagrams for defining the taper angle;
FIGS. 22A and 22B are another diagrams for defining the taper angle; and
FIG. 23 is a cross-sectional view showing a thin film transistor according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, a semiconductor device manufactured by carrying out the present invention will be described.
Embodiment Mode 1
First, a conductive film is formed on the entire surface of a substrate. The conductive film is formed into a desired shape through a first photolithography step. As a material of the conductive film, an element selected from W, WSi x , Al, Ti, Mo, Cu, Ta, Cr, Ni, and Mo, a film containing as a main component an alloy material or compound material containing the element as a main component, or a multi-layer film thereof can be enumerated. Later, the conductive film is etched to become a gate electrode or a gate wiring or a retention capacitance wiring.
Next, an insulating film is formed on the entire surface of the conductive film. Later, the insulating film functions as a gate insulating film. A first amorphous semiconductor film and a second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type) and a conductive film comprising a metallic material (a metallic material containing Al, Ti, Mo, Cu, Ta, Cr, Ni or Mo as a main component) are formed on the insulating film. Here, a conductive film containing Al as a main component is formed.
Then, an unnecessary portion of the layered film formed of the first amorphous semiconductor film and the second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type) and the conductive film comprising metallic material is removed by etching through a second photolithography step. Here, without changing the etching gas, the first amorphous semiconductor film and the second amorphous semiconductor film and the conductive film are etched. The etching is conducted using a chlorine type gas for example a mixed gas of Cl 2 and BCl 3 as an etching gas so that the ends of the conductive film comprising metallic material (Al) and the second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type) are etched perpendicularly to the substrate while the ends of the first amorphous semiconductor film are tapered. Note that the ends of the second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type) may also be tapered.
Here, because a conductive material containing Al as a main component as the conductive film to become a source electrode or a drain electrode later, etching is conducted using a mixture gas of Cl 2 and BCl 3 as an etching gas. However, not limited to that. When a material containing Ti is used, the side edge of the first amorphous semiconductor film can be tapered using the same mixture gas. Further, when a conductive material containing Ta as a main component is used for the conductive film, the side edge of the first amorphous semiconductor film can be tapered by using Cl 2 gas or a mixture gas of Cl 2 gas and CF 4 gas. Further, when a conductive material containing W as a main component is used for the conductive film, the side edge of the first amorphous semiconductor film can be tapered by using a mixture gas of Cl 2 gas and CF 4 gas and O 2 gas or a mixture gas of Cl 2 gas and SF 4 gas and O 2 gas.
Next, after removal of a second resist mask, another resist mask is formed by using a shadow mask so as to selectively remove the insulating film covering a pad portion of a terminal portion.
Next, a conductive film comprising a transparent conductive film is formed over the entire surface. As the transparent conductive film, ITO (indium oxide- tin oxide alloy) and an indium oxide—zinc oxide alloy (In 2 O 3 —ZnO) and zinc oxide (ZnO) are enumerated.
Next, a part of the first amorphous semiconductor film and the transparent conductive film and the conductive film comprising metallic material and the second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type) are removed through a third photolithography step to form a source region and a drain region provided in the second amorphous semiconductor film and to simultaneously form a source wiring from the conductive film comprising metallic material and form a pixel electrode from the transparent conductive film.
Further, when etching is conducted by using a chlorine gas for example a mixture gas of Cl2 and BCl3 as an etching gas in the third photolithography step, a part to become a channel formation region can be tapered as shown in FIG. 23 .
As described above, through three photolithography steps, a semiconductor device including a pixel TFT which has the first amorphous semiconductor film with the tapered ends, the source wiring comprising metallic material, a storage capacitor, and the terminal portion can be manufactured.
Embodiment Mode 2
First, a conductive film is formed on the entire surface of a substrate. The conductive film is formed into a desired shape through a first photolithography step. Later, the conducive film is etched to form a gate electrode or a gate wiring or a storage capacitance wiring.
Next, an insulating film is formed on the entire surface of the conductive film. Later, the insulating film functions as a gate insulating film. A first amorphous semiconductor film and a second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type) and a conductive film comprising metallic material (metallic material containing Al, Ti, Mo, Cu, Ta, Cr, Ni or Mo as a main component) are deposited on the insulating film.
Then, an unnecessary portion of the layered film formed of the first amorphous semiconductor film and the second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type) and the conductive film comprising metallic material is removed by etching through a second photolithography step. Here, the first amorphous semiconductor film and the second amorphous semiconductor film and the conductive film are etched without changing the etching gas. The etching is conducted using a chlorine type gas for example a mixed gas of Cl 2 and BCl 3 as an etching gas so that the ends of the conductive film comprising metallic material and the second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type) are formed to be perpendicular to the substrate while the ends of the first amorphous semiconductor film are tapered. Note that the ends of the second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type) may also be tapered.
Next, an unnecessary portion of the insulating film is removed by etching with continuous use of a second photomask which is used for etching the first amorphous semiconductor film and the second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type).
Next, a conductive film of a transparent conductive film is formed on the entire surface. As the transparent conductive film, ITO (indium oxide—tin oxide alloy) and indium oxide—zinc oxide alloy (In2O3—ZnO) and zinc oxide (ZnO) are enumerated.
Thereafter, a part of the first amorphous semiconductor film and the transparent conductive film and the conductive film comprising metallic material and the second amorphous semiconductor film containing an impurity element with one conductivity type (n-type or p-type) is removed through a third photolithography step to form a source region and a drain region of a gate electrode while forming a source wiring from the conductive film comprising metallic material and forming a pixel electrode from the transparent conductive film.
As described above, through three photolithography steps, a semiconductor display device including a pixel TFT which has the first amorphous semiconductor film with the tapered ends, the source wiring, a storage capacitor, and a terminal portion can be manufactured.
The present invention with the above-described structures will be described further in detail in the following Embodiments.
Embodiments
Embodiment 1
Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 4B . In Embodiment 1, a manufacturing method of a liquid crystal display device is described. A method of manufacturing an inverse-stagger TFT in a pixel portion on a substrate and manufacturing a storage capacitor to be connected to the TFT will be described in detail in the order of the manufacturing steps. In FIGS. 2A to 4B , a terminal portion, which is provided at the end of the substrate so as to be electrically connected to a wiring of a circuit provided on another substrate, is also illustrated in the steps of manufacturing a TFT. The cross-sectional views of FIGS. 2A to 4B correspond to the cross section taken along a line A–A′ in FIG. 1 .
First, a display device is manufactured by using a substrate 200 with light transmittance. As the substrate 200 , a glass substrate such as barium borosilicate glass and alumino borosilicate glass, as represented by #7059 glass and #1737 glass manufactured by Corning Inc., can be used. Besides, a light transmitting substrate such as a quartz substrate and a plastic substrate can also be used as the substrate 200 .
After forming a conductive film on the entire surface of the substrate 200 , a first photolithography step is conducted to form a resist mask. An unnecessary portion is removed by etching to form gate electrodes 202 and 203 , a storage capacitor wiring 204 , and a terminal portion 201 ( FIG. 2A ).
As a material for the electrodes 202 and 203 , an element selected from the group consisting of titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), chromium (Cr) and neodymium (Nd), an alloy containing the above element as a constituent, or a nitride containing the above element as a constituent, is used. Alternatively, the combination of plural selected from: an element selected from the group consisting of titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), chromium (Cr) and neodymium (Nd); an alloy containing the above element as a constituent; and a nitride containing the above element as a constituent, can be deposited as a laminate layer to form the electrodes 202 and 203 .
For application to a large screen, it is desirable to form gate wirings 202 and 203 including the gate electrodes, the capacitor wiring 204 and a terminal of the terminal portion 201 , using a low-resistance conductive material. Therefore, aluminum (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt) or the like, or an alloy containing the above element as a constituent can be used as a material. Since aluminum (Al), copper (Cu) and silver (Ag) are disadvantageous in their low thermal resistance, high corrosiveness and the like, however, these elements can be used in combination with a thermally resistant conductive material.
Next, an insulating film 207 is formed on the entire surface. A silicon nitride film is used as the insulating film 207 , and is formed to have a thickness of 50 to 200 nm, preferably, 150 nm. Note that the gate insulating film 207 is not limited to the silicon nitride film; an insulating film such as a silicon oxide film, a silicon nitride oxide film or a tantalum oxide film can also be used ( FIG. 2B ).
Next, a first amorphous semiconductor film 206 with a thickness of 50 to 200 nm, preferably, 100 to 150 nm, is formed on the entire surface of the insulating film 207 through a known method such as a plasma CVD method or a sputtering method. Typically, an amorphous silicon (a-Si) film is formed to have a thickness of 100 nm. As the first amorphous semiconductor film 206 , a microcrystalline semiconductor film and a compound semiconductor film with an amorphous structure, such as an amorphous silicon germanium film, or an amorphous silicon carbide film can also be used ( FIG. 2B ).
Next, a second amorphous semiconductor film 205 containing an impurity element with one conductivity type (n-type or p-type) is formed to have a thickness of 50 to 200 nm. The second semiconductor film 205 containing an impurity element with one conductivity type (n-type or p-type) is formed on the entire surface by a known method such as a plasma CVD method or a sputtering method. In Embodiment 1, the second amorphous semiconductor film 205 containing an n-type impurity element is formed by using a silicon target to which phosphorus (P) is added. Alternatively, the second amorphous semiconductor film 205 may be formed with a silicon target by sputtering in an atmosphere containing phosphorus. Further alternatively, the second amorphous semiconductor film 205 containing an impurity element that imparts an n-type conductivity may be formed of a microcrystalline silicon hydride film ( FIG. 2B ). Further, a conductive film 205 b comprising metallic material is formed to a thickness of 50 to 200 nm by using sputtering or the like.
Then, a second photolithography step is conducted to form a resist mask 208 . A first amorphous semiconductor film 209 and a second amorphous semiconductor film 210 containing an impurity element with one conductivity type (n-type or p-type) and a conductive film 210 b are formed to have a desired shape by selectively removing the conductive film and the first amorphous semiconductor film and the second amorphous semiconductor film by etching . In Embodiment 1, the first amorphous semiconductor film 209 and the second amorphous semiconductor film 210 containing an impurity element with one conductivity type (n-type or p-type) and the conductive film 210 b are formed by dry etching using a mixed gas of Cl 2 =40 sccm and BCl 3 =40 sccm as an etching gas. As a result of etching, the ends of the conductive film 210 b the second amorphous semiconductor film 210 a containing an impurity element with one conductivity type (n-type or p-type) are perpendicular to the substrate, whereas the ends of the first amorphous semiconductor film 209 are tapered at an angle in the range of 5 to 45 degrees ( FIG. 2C ).
The ends of the second amorphous semiconductor film 210 containing an impurity element with one conductivity type (n-type or p-type) may be tapered. Although the mixed gas of Cl 2 =40 sccm and BCl 3 =40 sccm is used as an etching gas in Embodiment 1, a composition of the etching gas is not limited to the above-mentioned composition as long as a TFT with a shape shown in FIG. 2C is obtained; for example, a gas selected from the group consisting of Cl 2 , BCl 3 , HCl and SiCl 4 , or a mixed gas of a plurality of gases selected from the above group, can be used as an etching gas.
Next, after removal of the resist mask 208 , another resist mask is formed by using a shadow mask. After the insulating film 207 , which covers a pad portion of the terminal portion, is selectively removed to form an insulating film 301 , the resist mask is removed ( FIG. 3A ). Instead of using the shadow mask, a resist mask formed by screen printing may alternatively be used as an etching mask.
Then, a conductive film 302 of a transparent conductive film is formed on the entire surface ( FIG. 3B ). The conductive film 302 is formed by sputtering or vacuum evaporation, using indium oxide (In 2 O 3 ) or an alloy of indium oxide and tin oxide (In 2 O 3 -SnO 2 ; abbreviated as ITO) as a material.
Next, a third photolithography step is conducted to form a resist mask 403 . An unnecessary portion is removed by etching to form a pixel electrode 405 from the transparent conductive film and to form a source wiring 402 and a drain electrode 404 and to expose a part of the first amorphous semiconductor film ( FIG. 4A ). The etching treatment of the conductive film comprising the transparent conductive film is conducted in a chlorine type solution. After the pixel electrode 405 is formed, etching gases are appropriately changed to etch the metal layer and the second amorphous semiconductor film . It is to be noted that in the above third photolithography step, an overetching is conducted to completely separate the source region and the drain region from each other, and further a part of the first amorphous semiconductor film is removed. In the removed region of the first amorphous semiconductor film, a channel is formed.
Further, similarly to the second photolithography step, a part of the first amorphous semiconductor film and the metal layer and the second amorphous semiconductor film may be etched at a time by using a chlorine type gas in the third photolithography step. In that case, the etched region of the first amorphous semiconductor film overlaps with the gate wiring with a gate insulating film therebetween and does not overlap with the source region or the drain region. The region overlapping with the gate wiring with a gate insulating film therebetween in the first amorphous semiconductor film is referred to as a channel formation region (back channel part). Further, the etched region in the first amorphous semiconductor film has a taper shape in which thickness thereof becomes thinner toward a center of the region. Accordingly, it is possible to manufacture a channel etch type TFT having a channel formation region free from a step.
Subsequently, a resist mask 401 is removed. FIG. 4B shows a cross-sectional view in this state.
As described above, through three photolithography steps, an active matrix substrate comprising a source wiring 402 and a pixel TFT of an inverse stagger type and the storage capacitor 408 and the terminal portion 409 can be obtained. With respect to the following steps, using the know technique, formation of orientation film and rubbing treatment and sticking of a counter substrate and injection of liquid crystal and sealing and sticking of FPC are conducted to complete a liquid crystal display device of transmission type.
Further, if necessary, a protective film comprising a silicon nitride film or a silicon oxynitride film may be formed. It is not provided over a terminal electrode connected with FPC.
The TFT including an active layer formed of the amorphous semiconductor film, obtained in Embodiment 1, has a small field-effect mobility, i.e., only about 1 cm 2 /Vsec. Therefore, a driving circuit for performing the image display is formed with an IC chip, and is mounted through TAB (tape automated bonding) or COG (chip on glass).
Further, a TFT having a multi-gate structure comprising a plurality of channel formation regions, here a TFT having a double-gate structure, is shown in Embodiment 1. However, a single gate structure may be used without limitation.
Embodiment 2
The semiconductor display device including the channel etch type TFT in the pixel portion has been described in Embodiment 1, while a semiconductor display device including a channel stop type TFT in the pixel portion will be described in Embodiment 2 with reference to FIGS. 5A to 7C .
First, a semiconductor display device is manufactured by using a substrate 500 with light transmittance. As the substrate 500 , a glass substrate such as barium borosilicate glass and alumino borosilicate glass, as represented by #7059 glass and #1737 glass manufactured by Corning Inc., can be used. Besides, a light transmitting substrate such as a quartz substrate and a plastic substrate can also be used as the substrate 500 .
After forming a conductive film on the entire surface of the substrate 500 , a first photolithography step is conducted to form a resist mask. An unnecessary portion is removed by etching to form gate electrodes 502 and 503 , a storage capacitor wiring 504 , and a terminal portion 501 ( FIG. 5A ).
As a material for the electrodes 502 and 503 , an element selected from the group consisting of titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), chromium (Cr) and neodymium (Nd), an alloy containing the above element as a constituent, or a nitride containing the above element as a constituent, is used. Alternatively, the combination of plural selected from: an element selected from the group consisting of titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), chromium (Cr) and neodymium (Nd); an alloy containing the above element as a constituent; and a nitride containing the above element as a constituent, can be deposited as a laminate layer to form the electrodes 502 and 503 .
For application to a large screen, it is desirable to form the gate wirings 502 and 503 including the gate electrodes, the capacitor wiring 504 and the terminal 501 of the terminal portion, using a low-resistance conductive material. Therefore, aluminum (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt) or the like, or an alloy containing the above element as a constituent, can be used as a material. However, since aluminum (Al), copper (Cu) and silver (Ag) are disadvantageous in their low thermal resistance, high corrosiveness and the like, these elements can be used in combination with a thermally resistant conductive material.
Next, an insulating film 506 is formed on the entire surface. A silicon nitride film is used as the insulating film 506 , and is formed to have a thickness of 50 to 200 nm, preferably, 150 nm. Note that the gate insulating film 506 is not limited to the silicon nitride film; an insulating film such as a silicon oxide film, a silicon nitride oxide film or a tantalum oxide film can also be used ( FIG. 5B ).
Next, an amorphous semiconductor film 505 with a thickness of 50 to 200 nm, preferably, 100 to 150 nm, is formed on the entire surface of the insulating film 506 through a known method such as a plasma CVD method or a sputtering method. Typically, an amorphous silicon (a-Si) film is formed to have a thickness of 100 nm ( FIG. 5B ).
Then, a second photolithography step is conducted to form a resist mask 507 . An unnecessary portion is removed by etching to form an amorphous semiconductor film 508 . In Embodiment 2, the amorphous semiconductor film 508 is formed by dry etching using a mixed gas of Cl 2 =40 sccm and BCl 3 =40 sccm as an etching gas. As a result of etching, the ends of the amorphous semiconductor film 508 are tapered at an angle in the range of 5 to 45 degrees. Although the mixed gas of Cl 2 =40 sccm and BCl 3 =40 sccm is used as an etching gas in Embodiment 2, a composition of the etching gas is not limited to the above-mentioned composition as long as a TFT with a shape shown in FIG. 5C is obtained; for example, a gas selected from the group consisting of Cl 2 , BCl 3 , HCl and SiCl 4 , or a mixed gas of a plurality of gases selected from the above group can be used as an etching gas.
Next, after removal of the resist mask 507 , another resist mask is formed by using a shadow mask. After the insulating film 506 , which covers a pad portion of the terminal portion, is selectively removed to form an insulating film 601 , the resist mask is removed ( FIG. 6A ). Instead of using the shadow mask, a resist mask formed by screen printing may alternatively be used as an etching mask.
Next, a doping step is conducted to form an LDD (lightly doped drain) region of the n-channel TFT. The doping is performed by ion doping or ion implantation. Phosphorus is added as an n-type impurity so as to form impurity regions 604 to 606 with the use of second insulating films 602 and 603 as masks. A donor density of these regions is set to 1×10 16 to 1×10 17 /cm 3 .
Then, a conductive film 608 of a transparent conductive film is formed on the entire surface ( FIG. 6C ). The conductive film 608 is formed by sputtering or vacuum evaporation, using indium oxide (In 2 O 3 ) or an alloy of indium oxide and tin oxide (In 2 O 3 -SnO 2 ; abbreviated as ITO) as a material. An etching treatment for such a material is conducted with a chlorine type solution.
Next, a third photolithography step is conducted to form a resist mask 701 . An unnecessary portion is removed by etching to form a source wiring 706 , a source region 702 , a drain region 704 and a pixel electrode 705 ( FIG. 7B ).
Subsequently, the resist mask 701 is removed. FIG. 7C shows a cross-sectional view in this state.
As described above, through three photolithography steps, a light transmitting semiconductor display device including the source wiring 706 , an inverse-stagger pixel TFT 707 , a storage capacitor 708 and a terminal portion 709 can be manufactured.
As in Embodiment 1, a driving circuit formed with an IC chip is mounted to perform the image display in Embodiment 2.
Embodiment 3
Embodiment 3 of the present invention will be described with reference to FIGS. 8 to 10C . In Embodiment 3, a manufacturing method of a liquid crystal display device is described. A method of manufacturing an inverse-stagger TFT in a pixel portion on a substrate and manufacturing a storage capacitor connected to the TFT will be described in detail in the order of the manufacturing steps. In FIGS. 9A to 10C , a terminal portion, which is provided at the end of the substrate so as to be electrically connected to a wiring of a circuit provided on another substrate, is also illustrated in the steps of manufacturing a TFT. The cross-sectional views of FIGS. 9A to 10C correspond to the cross section cut along a line A–A′ in FIG. 8 .
First, a semiconductor display device is manufactured by using a substrate 1200 with light transmittance. As the substrate 1200 , a glass substrate such as barium borosilicate glass and alumino borosilicate glass, as represented by #7059 glass and #1737 glass manufactured by Corning Inc., can be used. Besides, a light transmitting substrate such as a quartz substrate and a plastic substrate can also be used as the substrate 1200 .
After forming a conductive film on the entire surface of the substrate 1200 , a first photolithography step is conducted to form a resist mask. An unnecessary portion is removed by etching so as to form gate electrodes 1202 and 1203 , a storage capacitor wiring 1204 , and a terminal portion 1201 ( FIG. 9A ).
As a material for the electrodes 1202 and 1203 , an element selected from the group consisting of titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), chromium (Cr) and neodymium (Nd), an alloy containing the above element as a constituent, or a nitride containing the above element as a constituent, is used. Alternatively, the combination of plural selected from: an element selected from the group consisting of titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), chromium (Cr) and neodymium (Nd); an alloy containing the above element as a constituent; and a nitride containing the above element, can be deposited as a laminate layer to form the electrodes 1202 and 1203 .
For application to a large screen, it is desirable to form gate wirings including the gate electrodes 1202 and 1203 , the capacitor wiring 1204 and a terminal of the terminal portion 1201 , using a low-resistance conductive material. Therefore, aluminum (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt) or the like or an alloy containing the above element as a constituent can be used as a material. However, since aluminum (Al), copper (Cu) and silver (Ag) are disadvantageous in their low thermal resistance, high corrosiveness and the like, these elements can be used in combination with a thermally resistant conductive material.
Next, an insulating film 1207 is formed on the entire surface. A silicon nitride film is used as the insulating film 1207 , and is formed to have a thickness of 50 to 200 nm, preferably, 150 nm. The gate insulating film 1207 is not limited to the silicon nitride film; an insulating film such as a silicon oxide film, a silicon nitride oxide film or a tantalum oxide film can also be used ( FIG. 9B ).
Next, a first amorphous semiconductor film 1206 with a thickness of 50 to 200 nm, preferably, 100 to 150 nm, is formed on the entire surface of the insulating film 1207 through a known method such as a plasma CVD method or a sputtering method. Typically, an amorphous silicon (a-Si) film is formed to have a thickness of 100 nm. As the first amorphous semiconductor film 1206 , a microcrystalline semiconductor film and a compound semiconductor film with an amorphous structure, such as an amorphous silicon germanium film, or an amorphous silicon carbide film can also be used ( FIG. 9B ).
Next, a second amorphous semiconductor film 1205 containing an impurity element with one conductivity type (n-type or p-type) is formed to have a thickness of 50 to 200 nm. The second semiconductor film 1205 containing an impurity element with one conductivity type (n-type or p-type) is formed on the entire surface by a known method such as a plasma CVD method or a sputtering method. In Embodiment 3, the second amorphous semiconductor film 1205 containing an n-type impurity element is formed by using a silicon target to which phosphorus (P) is added. Alternatively, the second amorphous semiconductor film 1205 may be formed with a silicon target by sputtering in an atmosphere containing phosphorus. Further alternatively, the second amorphous semiconductor film 1205 containing an impurity element that imparts an n-type conductivity may be formed of a microcrystalline silicon hydride film ( FIG. 9B ). Further, a conductive film 1205 b comprising metallic material is formed to a thickness of 50 to 200 nm by sputtering or the like. ( FIG. 9(B) )
Then, a second photolithography step is conducted to form a resist mask 1208 . A conductive film and a first amorphous semiconductor film 1209 and a second amorphous semiconductor film 1210 containing an impurity element with one conductivity type (n-type or p-type) are formed to have a desired shape by etching. In Embodiment 3, the first amorphous semiconductor film 1209 and the second amorphous semiconductor film 1210 containing an impurity element with one conductivity type (n-type or p-type) and the conductive film 1210 b are formed by dry etching using a mixed gas of Cl 2 =40 sccm and BCl 3 =40 sccm as an etching gas. As a result of etching, the ends of the conductive film 1210 b and the second amorphous semiconductor film 1210 containing an impurity element with one conductivity type (n-type or p-type) are formed perpendicular to the substrate, whereas the ends of the first amorphous semiconductor film 1209 are tapered at an angle in the range of 5 to 45 degrees ( FIG. 9C ).
The ends of the second amorphous semiconductor film 1210 containing an impurity element with one conductivity type (n-type or p-type) may also be tapered. Although the mixed gas of Cl 2 =40 sccm and BCl 3 =40 sccm is used as an etching gas in Embodiment 3, a composition of an etching gas is not limited to the above-mentioned composition as long as a TFT with a shape shown in FIG. 9C is obtained; for example, a gas selected from the group consisting of Cl 2 , BCl 3 , HCl and SiCl 4 or a mixed gas of a plurality of gases selected from the above group can be used as an etching gas.
Next, with continuous use of the resist mask 1208 , an insulating film 1211 is formed in a desired shape by etching. In Embodiment 3, the insulating film 1211 is formed by dry etching using a gas of CHF 3 =35 sccm as an etching gas ( FIG. 9C ). Although a gas of CHF 3 =35 sccm is used as an etching gas in Embodiment 3, a composition of the etching gas is not limited thereto as long as a TFT with a shape shown in FIG. 9C is manufactured.
Then, a conductive film 1301 of a transparent conductive film is formed on the entire surface ( FIG. 10A ). The conductive film 1301 is formed by sputtering, vacuum evaporation, or the like using indium oxide (In 2 O 3 ) or an alloy of indium oxide, tin oxide (In 2 O 3 -SnO 2 ; abbreviated as ITO) etc., as a material.
Next, a third photolithography step is conducted to form a resist mask 1302 . An unnecessary portion is removed by etching to form a source wiring 1303 , a source region, a drain region, a drain electrode 1305 and a pixel electrode 1306 ( FIG. 10B ). It is to be noted that after the conductive film comprising a transparent conductive film is subjected to en etching treatment using a chlorine type solution, the metal film and the second amorphous semiconductor film are etched by using a gas. Further, in the above third photolithography step, in order to completely separate the source region and the drain region from each other, an overetching is conducted, and a part of the first amorphous semiconductor film is removed.
Subsequently, the resist mask 1302 is removed. FIG. 10C shows a cross-sectional view in this state.
As described above, through three photolithography steps, an active matrix substrate including the source wiring 1303 , an inverse-stagger pixel TFT 1308 , a storage capacitor 1309 and a terminal portion 1310 can be manufactured. With respect to the following steps, by using known technique, formation of orientation film and rubbing treatment and sticking of counter substrate and injection of liquid crystal and sealing and sticking of FPC are conducted to complete a transmission type liquid crystal display device.
Further, if necessary, a protective film comprising silicon nitride film and silicon oxynitride film may be formed. It is not provided over a terminal electrode connected with FPC or the like.
The TFT including an active layer formed of the amorphous semiconductor film, obtained in Embodiment 3, has a small field-effect mobility, i.e., only about 1 cm 2 /Vsec. Therefore, a driving circuit for performing the image display is formed with an IC chip, and is mounted through TAB (tape automated bonding) or COG (chip on glass).
Further, a TFT having a multi-gate structure comprising a plurality of channel formation regions, here a TFT having a double gate structure, is illustrated in Embodiment 3. However, a single gate structure may be used without limitation.
Embodiment 4
The semiconductor display device including the channel etch type TFT in the pixel portion has been described in Embodiment 3, while a semiconductor display device including a channel stop type TFT in the pixel portion will be described in Embodiment 4 with reference to FIGS. 11A to 13B .
First, a semiconductor display device is manufactured by using a substrate 1400 with light transmittance. As the substrate 1400 , a glass substrate such as barium borosilicate glass and alumino borosilicate glass, as represented by #7059 glass and #1737 glass manufactured by Corning Inc., can be used. Besides, a light transmitting substrate such as a quartz substrate and a plastic substrate can also be used as the substrate 1400 .
After forming a conductive film on the entire surface of the substrate 1400 , a first photolithography step is conducted to form a resist mask. An unnecessary portion is removed by etching to form gate electrodes 1402 and 1403 , a storage capacitor wiring 1404 , and a terminal portion 1401 ( FIG. 11A ).
As a material for the electrodes 1402 and 1403 , an element selected from the group consisting of titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), chromium (Cr) and neodymium (Nd), an alloy containing the above element as a constituent, or a nitride containing the above element as a constituent, is used. Alternatively, the combination of plural selected from: an element selected from the group consisting of titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), chromium (Cr) and neodymium (Nd); an alloy containing the above element as a constituent; and a nitride containing the above element as a constituent, can be deposited as a laminate layer to form the electrodes 1402 and 1403 .
For application to a large screen, it is desirable to form gate wirings including the gate electrodes 1402 and 1403 , the storage capacitor 1404 and a terminal of the terminal portion 1401 , using a low-resistance conductive material. Therefore, aluminum (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt) or the like, or an alloy containing the above element as a constituent, can be used as a material. However, since aluminum (Al), copper (Cu) and silver (Ag) are disadvantageous in their low thermal resistance, high corrosiveness and the like, these elements can be used in combination with a thermally resistant conductive material.
Next, an insulating film 1406 is formed on the entire surface. A silicon nitride film is used as the insulating film 1406 , and is formed to have a thickness of 50 to 200 nm, preferably, 150 nm. The gate insulating film 1406 is not limited to the silicon nitride film; an insulating film such as a silicon oxide film, a silicon nitride oxide film or a tantalum oxide film can also be used ( FIG. 11B ).
Next, an amorphous semiconductor film 1405 with a thickness of 50 to 200 nm, preferably, 100 to 150 nm, is formed on the entire surface of the insulating film 1406 through a known method such as a plasma CVD method or a sputtering method. Typically, an amorphous silicon (a-Si) film is formed to have a thickness of 100 nm ( FIG. 11B ).
Then, a second photolithography step is conducted to form a resist mask 1407 . An unnecessary portion is removed by etching to form an amorphous semiconductor film 1408 . In Embodiment 4, the amorphous semiconductor film 1408 is formed by dry etching using a mixed gas of Cl 2 =40 sccm and BCl 3 =40 sccm as an etching gas. As a result of etching, the ends of the amorphous semiconductor film 1408 are tapered at an angle in the range of 5 to 45 degrees. Although the mixed gas of Cl 2 =40 sccm and BCl 3 =40 sccm is used as an etching gas in Embodiment 4, a composition of an etching gas is not limited to the above-mentioned composition as long as a TFT with a shape shown in FIG. 11C is obtained; for example, a gas selected from the group consisting of Cl 2 , BCl 3 , HCl and SiCl 4 or a mixed gas of a plurality of gases selected from the above group can be used as an etching gas.
Next, with continuous use of the resist mask 1407 , an insulating film 1409 is formed in a desired shape by etching. In Embodiment 4, the insulating film 1409 is formed by dry etching using a gas of CHF 3 =35 scem as an etching gas ( FIG. 11C ). Although a gas of CHF 3 =35 sccm is used as an etching gas in Embodiment 4, a composition of the etching gas is not limited thereto as long as a TFT with a shape shown in FIG. 11C is manufactured.
Next, a doping step is conducted to form an LDD (lightly doped drain) region of the n-channel TFT. The doping is performed by ion doping or ion implantation. Phosphorus is added as an n-type impurity so as to form impurity regions 1503 to 1505 with the use of second insulating films 1501 and 1502 as masks. A donor density of these regions is set to 1×10 16 to 1×10 17 /cm 3 ( FIG. 12A ).
Then, a conductive film 1506 of a transparent conductive film is formed on the entire surface ( FIG. 12B ). The conductive film 1506 is formed by sputtering or vacuum evaporation, using indium oxide (In 2 O 3 ) or an alloy of indium oxide and tin oxide (In 2 O 3 SnO 2 ; abbreviated as ITO) as a material. An etching treatment for such a material is conducted with a chlorine type solution.
Next, a third photolithography step is conducted to form a resist mask 1601 . An unnecessary portion is removed by etching to form a source wiring 1605 , a source region 1602 , a drain region 1604 and a pixel electrode 1605 ( FIG. 13A ).
Subsequently, the resist mask 1601 is removed. FIG. 13B shows a cross-sectional view in this state.
As described above, through three photolithography steps, a light transmitting semiconductor display device including the source wiring 1606 , an inverse-stagger pixel TFT 1607 , a storage capacitor 1608 and a terminal portion 1609 can be manufactured.
As in Embodiment 3, a driving circuit formed with an IC chip is mounted to perform the image display in Embodiment 4.
Embodiment 5
The active-matrix substrate and the liquid crystal display device, manufactured through embodiments of the present invention, can be used for various electro-optical apparatuses. Specifically, the present invention can be applicable for all electronic devices including such an electro-optical apparatus as a display section.
As examples of such electronic devices, video cameras, car navigation systems, personal computers and portable information terminals (such as mobile computers, portable telephones, or electronic books) can be given. Some examples of these electronic devices are shown in FIGS. 14A to 14D .
FIG. 14A illustrates a personal computer including a main body 801 , an image input section 802 , a display section 803 and a keyboard 804 .
FIG. 14B illustrates a video camera including a main body 805 , a display section 806 , a voice input section 807 , operation switches 808 , a battery 809 and an image-receiving section 810 .
FIG. 14C is a digital camera including a main body 811 , a camera section 812 , an image-receiving section 813 , operation switches 814 , and a display section 815 .
FIG. 14D illustrates a player utilizing a recording medium containing the recorded programs (hereinafter, simply referred to as a recording medium). This player includes a main body 816 , a display section 817 , a speaker section 818 , a recording medium 819 , and operation switches 820 . This device uses a DVD (Digital Versatile Disc), a CD or the like as a recording medium to allow the music, the movies, the games and the Internet to be enjoyed.
As described above, the present invention has an extremely wide application, and thus is applicable to electronic devices of various fields. The electronic devices in Embodiment 5 can be realized with the structure obtained by any combination of Embodiment mode 1, Embodiment mode 2 or any combination of Embodiments 1 to 4.
According to the present invention, the conductive film and the second amorphous semiconductor film and the first amorphous semiconductor film can be removed with the same etching gas. Further, a TFT can be manufactured with three photomasks to realize improvement in productivity and yield.
Moreover, the ends of the first amorphous semiconductor film are tapered in the present invention. As a result, the problems of poor coverage of the pixel electrode can be solved.
|
The present invention has an object to provide an active-matrix liquid crystal display device that realizes the improvement in productivity as well as in yield. In the present invention, a laminate film comprising the conductive film comprising metallic material and the second amorphous semiconductor film containing an impurity element of one conductivity type and the amorphous semiconductor film is selectively etched with the same etching gas to form a side edge of the first amorphous semiconductor film 1001 into a taper shape. Thereby, a coverage problem of a pixel electrode 1003 can be solved and an inverse stagger type TFT can be completed with three photomask. Selected figure is FIG. 15.
| 7
|
BACKGROUND OF THE INVENTION
This invention relates to an air-release valve, of the type which is commonly used in a system containing liquid with gas above it. A common use of such a valve is for the release of gases from sewage systems during flow conditions, as distinct from the conditions which obtain during the charging and discharging of a pipeline or container.
Previously, a valve of this type has had a single orifice for the release of gas, the orifice being opened or closed either by a float, usually a rubber-covered sphere, or alternatively by a linkage mechanism interposed between the orifice and the float, and operated by the float.
A disadvantage of the former type of valve is that the level of liquid in relation to the ball is fairly high, with the result that the orifice may be fouled by the liquid or any floating debris in the pipeline. Also, when such a valve is closing during the charging of a pipeline or container, the high level of liquid relative to the ball may result in a quantity of the liquid being ejected from the valve orifice. In normal operation, the use of a fixed orifice results in the orifice seating bleeding continuously as the air and gases accumulate, and this continuous bleeding can erode and wear the orifice and the surface of the ball or float.
In the latter type of valve mentioned, the linkage mechanism is likely to become fouled by the liquid or floating debris, causing malfunction of the valve and the release of contained liquid. Also, such a linkage is liable to wear, reducing the efficiency of control and gas release.
In either form of air-release valve hitherto used, there is a likelihood of fumes and odours escaping from the pipeline when the line is draining or in a drained condition.
The present invention has been devised with the general object of overcoming the said present disadvantages by providing an air-release valve which will operate efficiently, is not liable to malfunction as a result of fouling from debris, and which is efficiently sealed when a pipeline or container is draining or in a drained condition.
SUMMARY OF THE INVENTION
The invention resides broadly in an air-release valve including a body; a float chamber in the body; a passage leading to the float chamber for connection to a pipeline or container; a float vertically movable in the float chamber; a top chamber in the body, a movable member vertically movable in the top chamber and adapted to be raised in the top chamber by the float rising in the float chamber or by gas pressure in the float chamber; a primary air release orifice through the said movable member from the float chamber to the top chamber; a secondary air release orifice from the top chamber to atmosphere, first sealing means connected to the float and adapted, when the float rises in the float chamber, to close the said primary orifice; and secondary sealing means conected to the said movable member and adapted when the said movable member is moved upwardly in the top chamber to close the said secondary orifice. Other features of the invention will become apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying drawing is a sectional view of an air-release valve according to a preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The valve illustrated includes a body 10 within which is a float chamber 11. The body tapers at the bottom to an inlet 12 which is externally threaded for connection to a sewerage main (not shown).
A float 13, weighted at the bottom, is freely movable vertically in the float chamber 11, and within guides 14 extending inwardly from the float chamber wall. The downwardly tapered bottom part of the float is formed with projections 15 which support the float in its lowermost position, as shown, resting against the tapered lower part of the valve chamber and ensuring that the inlet 12 is not closed by the float.
On top of the float there is secured a central resilient disc-shaped float seal pad 16, and, at a lower level, a concentric resilient float seal ring 17.
A bonnet 18 is bolted on top of the valve body 10 and is sealed by an O-ring 19. The bonnet is formed with an axial passage of which the upper part is tapped. A cylindrical liner 20 is secured in the main lower part of the axial passage, its lower end extending below the bottom of the passage to form an annular seating 21.
A piston 22 is slidable in the liner 20, and is sealed by an O-ring 23 in an annular groove 24 about the piston. A recess 25 is formed in the top of the piston, and below this recess an axial aperture is formed through the piston, its reduced-diameter lower part constituting the primary orifice 26 of the valve. About the bottom end of this primary orifice, the piston is shaped to form an annular seating 27.
A valve top 28 is screwed into the tapped upper part of the axial aperture of the bonnet 18, and the space enclosed within the liner 20, between the piston 22 and the valve top 28 constitutes a top chamber 29. The tope 28 has a recess 30 formed in its lower end, and has a tapped axial aperture into which there is screwed a threaded orifice plug 31 with an axial passage, the lower reduced-diameter part of which constitutes a secondary orifice 32. The bottom of the plug 31 is shaped to form an annular seating 33 about the lower end of the secondary orifice 32.
The piston 22 is urged downwardly by a helical compression primary spring 34, its upper end seated in the recess 30 of the valve top 28, its lower end on a spring retainer 35 in the recess 25 of the piston. A secondary spring 36, which is a coned helical spring which oerates in both the tension and compression regions during the operation of the valve, is seated on the top of the piston 22, located coaxially within the primary spring 34, and has fixed to its upper end a secondary orifice seal pad 37. In order to provide the necessary tension in the spring 36, it will be understood that the spring is connected at the top thereof to the pad 37 and at the bottom thereof, directly or indirectly, to the top of the piston 22.
A self-cleaning perforated air vent fitting 38, serving also as a frame trap, is provided in the enlarged-diameter upper end of the axial aperture of the orifice plug 31, and a cap 39 with gas outlet passages 40 is screwed onto the threaded upper end of the valve top 28.
The valve is not designed to vent large amounts of gas during the pipeline charging operations, but it will vent some of the gas in the line. As charging commences, the gas pressure in the line, and therefore in the float chamber 11, is increased, and acts on the bottom face of the piston 22 to force the piston upwards, compressing the primary spring 34 and, in lifting the seating 27 from the seal pad 16, opening the primary orifice 26, so that gas escapes into the top chamber 20. If the movement has been small, the gases in the top chamber 29 will then pass through the secondary orifice 32, the axial passage of the orifice plug 31, and the gas outlet passages 40 of the cap 39. If the pressure rise has been rapid and the piston 22 has moved to the extent of lifting the seal pad 37 to close the secondary orifice 32, the pressures in the top chamber 29 and the float chamber 11 will equalize, and the primary spring 34 will move the piston 22 down, reopening the secondary orifice 32. The valve will then vent the gases continuously in this equilibrium position. The piston will be restrained against vibration due to the damping effect of the O-ring 23.
When the piston 22 is moved down by the primary spring 34, the pressure in the top chamber 29 initially holds the seal pad 37 on the secondary orifice 32, until the tension of the secondary spring 36 is sufficient to snap the seal pad 37 down to open position.
When liquid level is rising during charging, then assuming the float 13 and the piston 22 to be initially in the equilibrium position described above, when the liquid enters the float chamber 11, the float 13 will rise and seal the primary orifice 26 with its central float pad 16. The gas pressure within the pipeline and the float chamber acting on the bottom of the piston 22, and the force exerted by the rising float 13, will move the piston and the float to top positions, the primary spring 34 being compressed, the seal pad 37 being brought up to close the secondary orifice 32, the secondary spring 36 also being compressed. The top chamber 29 is then completely sealed. As the gases are captured by the valve and held in the float chamber 11, the level of liquid is this chamber is forced down, so the float drops to open the primary orifice 26 and permit gas to enter the top chamber 29. The gas pressure above and below the piston 22 then being in near equilibrium, the primary spring 34 forces the piston 22 down. Simultaneously the liquid level in the float chamber 11 rises, so the float is again lifted to close the primary orifice 26 with its central seal pad 16. This operation is repeated, the piston 22 being lowered each time until the secondary orifice 32 is opened to release the accumulated gases to atmosphere. This release of pressure from the top chamber 29 removes the equilibrium of pressure across the piston 22, causing the gas pressure in the float chamber to move the piston 22 up assisting in the venting operation. The cycle as above described will then be repeated to the extent required to discharge the accumulated gases in the float chamber.
The normal operation of the valve, otherwise than when the pipeline is being charged or drained, is as above described.
During draining of the pipeline, the gas pressure in the pipeline and in the float chamber 11 is reduced, and the entrapped gases expand, lowering the liquid level, and the valve will exhaust to atmosphere as before described. With the gases fully exhausted, the top chamber 29 will be vented to atmosphere, and the piston 22 will be in bottom position, as shown in the drawing, with the primary orifice 26 closed against the float's central seal pad 16. If the pressure in the pipeline and float chamber is reduced further, the piston 22 will remain held against the float and effectively seal the pipeline. This sealing removes the problem of odours that can be released from the pipeline while under maintenance. Also, if the external pressure surrounding the valve should be increased, as may occur during flooding, the valve seals the contents of the pipeline and prevents contamination of the contents of the pipeline or of the environment.
The valve is such that normal maintenance can be carried out without the necessity to depressurize the pipeline, or to operate an isolating valve or the like. The valve is dismantled by removing the cap 39, then the orifice plug 31. As this is removed, the top chamber 29 is depressurized, and the piston 22 is lifted to full extent when it is brought against the bottom of the valve top 28. The valve top 28 is then unscrewed, and the float 13 is consequently permitted to rise so that its seal ring 17 is brought against the fixed protruding bottom end or seating 21 of the liner 20, the seal between the float and liner being thus completed before the top 28 has been completely disengaged from the bonnet 18. The removal of the valve top 28 gives full access to all the mechanisms of the valve, allowing replacement as required. For re-assembly, the orifice plug 31 is engaged in the valve top 28 before the valve top is screwed into the bonnet 18. As the valve top 28 is being screwed into place, the seal pad closes the secondary orifice 32, and at the same time the float's seal ring 17 remains firmly against the seating 21 about the bottom of the liner 20, so there is a sealed chamber between the bottom of the valve top 28 and the top of the float 13. As the vlave top is further screwed into place, the pressure rises in this sealed chamber, relieving the high contact pressure on the primary orifice 26 by the float's central seal pad 16 as the seal between the liner 20 and the float seal ring 17 is released. When the top 28 has been fully screwed into place, the cap 39 is refitted.
So that preventive maintenance may be carried out, the valve may be provided with a back-wash system. A nozzle 41 leads into the upper part of the float chamber, and may be connected by suitable passages formed in the valve body 10 to a source of water under pressure, the flow of which through the nozzle is controlled by a handle 42 which is rotatable to open or close a simple valve (not shown). When this valve is opened by means of the handle 42, a jet of water under pressure is directed through the nozzle 41 to clean away any accumulation of debris, particularly from the top of the float 13 and from the seal pad 16, seal ring 17 and bottom of the primary orifice 26.
|
An air release valve, used in a system containing liquid with gas above it, has a float chamber connected to the system and containing a float which normally closes a primary orifice leading through a vertically movable spring-loaded piston to an upper chamber. When the piston is raised by gas pressure in the float chamber to open the primary orifice, a seal pad, spring-mounted above the piston, closes a secondary orifice from the top chamber to atmosphere until the increased pressure in the top chamber moves the piston down to open the secondary orifice. When liquid entering the float chamber causes the float to rise, closing the primary orifice and lifting the piston, the seal pad closes the secondary orifice, trapped gas lowers the liquid and float, and the primary orifice opens.
| 5
|
CROSS REFERENCE TO RELATED APPLICATION AND INCORPORATION BY REFERENCE
[0001] This is a continuation of U.S. application Ser. No. 15/270,101, filed on Sep. 20, 2016. Furthermore, this application claims the benefit of priority of Japanese application number 2015-186403, filed on Sep. 24, 2015. The disclosures of both of these prior applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Technical Field
[0002] The present invention relates to a semiconductor device and a manufacturing method of a semiconductor device.
Background Art
[0003] Semiconductor devices in which a semiconductor layer having a sensor formed therein and a semiconductor layer having a peripheral circuit formed therein are stacked on the same semiconductor substrate through an insulating film are known. One example of such semiconductor devices is an X-ray sensor in which circuit elements such as a transistor and resistance and a PN diode that functions as a sensor are formed together on the same SOI (silicon on insulator) substrate.
[0004] In the X-ray sensor formed on the SOI substrate, a MOS-FET (metal oxide semiconductor-field effect transistor: will be simply referred to as a transistor below) for the circuit operation and the like are formed in a silicon layer of the SOI substrate, and a pixel sensor is formed adjacent to the substrate. Between the silicon layer and the substrate, a buried oxide (BOX) film is interposed. When X-ray is radiated, the X-ray collides with atoms in the silicon and the oxide film, which form the X-ray sensor, and generates electron-hole pairs. Among them, electrons or holes generated near the substrate are attracted to an electrode due to the field effect, extracted to the outside, and converted to an electric signal. This way, the function of the X-ray sensor is realized. However, when electron-hole pairs are generated in an oxide film such as the buried oxide film, positive charges are trapped and accumulated in the oxide film in some cases.
[0005] As the total amount of X-ray radiated to the X-ray sensor increases, the total amount of positive charges accumulated in the oxide film also increases. In some cases, the accumulated positive charges cause a characteristic change of the transistor, and the degree of the characteristic change may fluctuate depending on the amount of accumulated positive charges. In particular, positive charges trapped in the field oxide film that faces the channel region of the transistor, or positive charges trapped in the buried oxide film might change the threshold voltage or the current amount of the transistor or generate a leak current that is not relevant to the control by the gate.
[0006] One known example of the prior art that achieves an X-ray sensor configured to suppress a leak current is a semiconductor device disclosed in Japanese Patent Application Laid-open Publication No. 2013-069924 (will be referred to as Patent Document 1 below). As shown in FIG. 1 of Patent Document 1, a semiconductor device (100) includes a photodiode (30), a semiconductor region (14), a buried oxide film (10), and a semiconductor layer (9).
[0007] The photodiode (30) has a semiconductor layer (11) of one conductivity type, a first semiconductor region (182) of the other conductivity type that is disposed in a primary surface (151) of the semiconductor layer, semiconductor regions (191) and (192) of the one conductivity type that have a higher impurity concentration than that of the semiconductor layer (11), and a semiconductor region (99). The semiconductor regions (191) and (192) are formed in the primary surface (151) of the semiconductor layer (11) so as to be separated from the semiconductor region (182). The semiconductor region (99) of the one conductivity type has a higher impurity concentration than that of the semiconductor layer (11) and a lower impurity concentration than that of the semiconductor regions (191) and (192). The semiconductor region (99) is formed in the primary surface (151) of the semiconductor layer (11) at least between the semiconductor region (182) and the semiconductor regions (191) and (192).
[0008] The semiconductor region (14) of the other conductivity type is formed in the primary surface (151) of the semiconductor layer (11) and is given a fixed potential. The buried oxide film (10) is disposed on the primary surface (151) of the semiconductor layer (11). The semiconductor layer (9) is formed on the buried oxide film (10) and has a transistor element (40) formed therein.
[0009] In the semiconductor device (100) disclosed in FIG. 1 of Patent Document 1, the semiconductor region (99) functions as an inversion preventing layer of the primary surface (151) of the semiconductor layer (11), which suppresses the generation of a leak current at the interface of the semiconductor layer (11) and the buried oxide film 10. In the transistor element 40 formed in the semiconductor layer (9), the channel region thereof on the side closer to the buried oxide film (10) is not activated due to the effect of the semiconductor region (14), and therefore, it is possible to suppress the generation of a leak current that is not relevant to the control by the gate electrode (15).
SUMMARY OF THE INVENTION
[0010] In the X-ray sensor described above, in view of the above-mentioned phenomenon of the positive charges being trapped in the oxide film, there is a demand to suppress the characteristic change of the active element such as a transistor caused by the entrapment of charges in the oxide film (generally, insulating region) so that the accurate operation is ensured. However, an X-ray sensor that takes into consideration the phenomenon described above and that is configured to suppress the characteristic change of the active element caused by such a phenomenon has not been fully studied. The semiconductor device disclosed in FIG. 1 of Patent Document 1 is aiming at suppressing the generation of an unintended current, but the main focus thereof is to suppress a leak current that flows through the surface of the semiconductor layer (11) due to the interface state generated at the interface between the semiconductor layer (11) and the buried oxide film (10). Thus, the semiconductor device disclosed in Patent Document 1 is not designed to suppress the characteristic change of the transistor caused by the entrapment of electric charges in the buried oxide film (10) due to the X-ray radiation.
[0011] The present invention was made in view of the above-mentioned points, and an object thereof is to provide a semiconductor device that can suppress the characteristic change of an active element caused by the entrapment of charges in an insulating region, and a manufacturing method of the semiconductor device.
[0012] According to one aspect of the present invention, a semiconductor device includes a first semiconductor layer of a first conductivity type having a primary surface on one side thereof and a secondary surface on an opposite side thereof, and having a sensor therein, a second semiconductor layer of a second conductivity type having a circuit element formed therein, the second semiconductor layer being formed at said one side of the primary surface of the first semiconductor layer, an insulating layer formed between the first semiconductor layer and the second semiconductor layer, and being disposed on the primary surface of the first semiconductor layer, and a charge-attracting semiconductor layer of the first conductivity type configured to attract electrical charges generated in the insulating layer when a fixed voltage is supplied to the charge-attracting semiconductor layer.
[0013] According to another aspect of the invention, a semiconductor device includes a first semiconductor layer of a first conductivity type having a primary surface and a secondary surface and having a sensor therein, a second semiconductor layer of a second conductivity type having a circuit element formed therein, the second semiconductor layer being formed at a same side of the primary surface of the first semiconductor layer, and an insulating layer formed between the first semiconductor layer and the second semiconductor layer, the insulating layer being disposed on the primary surface of the first semiconductor layer so as to surround the circuit element, the insulating layer including a charge-attracting semiconductor pattern of the first conductivity type that is disposed near the circuit element, the charge-attracting semiconductor pattern being configured to attract electrical charges generated in the insulating layer.
[0014] According to one aspect of the invention, a manufacturing method of a semiconductor device includes preparing a semiconductor substrate that includes a first semiconductor layer of a first conductivity type, a first insulating layer formed on the first semiconductor layer, and a second semiconductor layer of a second conductivity type formed on the first insulating layer, forming, in a portion of the second semiconductor layer, an active region of the second conductivity type so as to be surrounded by a second insulating layer, the second insulating layer being integrally formed with the first insulating layer, and forming a charge-attracting semiconductor pattern in the first insulating layer so as to be adjacent to the active region, the charge-attracting semiconductor pattern being configured to attract electric charges generated in the first insulating layer or the second insulating layer.
[0015] According to another aspect of the invention, a manufacturing method of a semiconductor device includes preparing a semiconductor substrate that includes a first semiconductor layer of a first conductivity type, a first insulating layer formed on the first semiconductor layer, an intermediate semiconductor layer of the first conductivity type formed on the first insulating layer, a second insulating layer formed on the intermediate semiconductor layer, and a second semiconductor layer formed on the second insulating layer, forming, in a portion of the second semiconductor layer, an active region of the second conductivity type so as to be surrounded by a third insulating layer, the third insulating layer being integrally formed with the second insulating layer, and forming a charge-attracting semiconductor pattern in the second insulating layer so as to be adjacent to the active region, the charge-attracting semiconductor pattern being configured to attract electric charges generated in the second insulating layer or the third insulating layer.
[0016] According to the present invention, it is possible to provide a semiconductor device that can suppress the characteristic change of an active element caused by the entrapment of charges in an insulating region, and a manufacturing method of the semiconductor device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a vertical cross-sectional view showing an example of the configuration of a semiconductor device of Embodiment 1.
[0018] FIG. 2 is a plan view showing an example of the configuration of a charge-attracting part of Embodiment 1.
[0019] FIG. 3 is a vertical cross-sectional view for explaining how electrical charges are attracted in the semiconductor device of Embodiment 1.
[0020] FIGS. 4A to 4D are vertical cross-sectional views showing an example of a manufacturing method of the semiconductor device of Embodiment 1.
[0021] FIGS. 5A to 5D are vertical cross-sectional views showing an example of a manufacturing method of the semiconductor device of Embodiment 1.
[0022] FIGS. 6A to 6D are vertical cross-sectional views showing an example of a manufacturing method of the semiconductor device of Embodiment 1.
[0023] FIG. 7 is a plan view showing an example of the configuration of a charge-attracting part of Embodiment 2.
[0024] FIG. 8 is a vertical cross-sectional view showing an example of the configuration of a semiconductor device of Embodiment 3.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Embodiments of the present invention will be explained below with reference to figures. In the respective figures, constituting elements or parts that are identical or equivalent to each other are given the same reference characters, and overlapping descriptions will be omitted as necessary.
Embodiment 1
[0026] FIG. 1 is a vertical cross-sectional view showing an example of the configuration of a semiconductor device 100 of this embodiment. The semiconductor device 100 includes a photodiode 11 constituting an X-ray sensor and a transistor 51 that is a circuit element constituting a peripheral circuit. The photodiode 11 and the transistor 51 are formed in an SOI (silicon on insulator) substrate that is formed by stacking a first semiconductor layer 10 made of an n-type semiconductor, a first insulating layer 20 , and a second semiconductor layer 30 made of a p-type semiconductor in this order.
[0027] The photodiode 11 includes an anode 12 made of a high concentration p-type semiconductor and a cathode 13 made of a high concentration n-type semiconductor that are disposed on the surface of the first semiconductor layer 10 , which is made of low-concentration n-type silicon, so as to be separated from each other. The photodiode 11 also includes an anode electrode 74 connected to the anode 12 , a cathode electrode 75 connected to the cathode 13 , and a rear electrode 14 formed on the rear side of the first semiconductor layer 10 .
[0028] The circuit element including the transistor 51 is formed on the second semiconductor layer 30 at a position that does not overlap the photodiode 11 . The transistor 51 includes a channel region 53 , a gate electrode 55 formed on the channel region 53 , source and drain regions 52 made of a high concentration n-type semiconductor and disposed to have the channel region 53 therebetween, and source and drain electrodes 72 connected to the source and drain regions 52 respectively. The surface of the second semiconductor layer 30 is covered by a second insulating layer 40 made of an insulator such as a silicon oxide film (SiO 2 film).
[0029] The semiconductor device 100 also includes a charge-attracting part 60 as a charge-attracting semiconductor pattern. The charge-attracting part 60 of this embodiment includes a buried polysilicon (polycrystalline silicon) 80 as a charge-attracting semiconductor layer, and a buried well 84 as a fixed potential region, and a buried polysilicon electrode 82 is connected to the buried polysilicon 80 , and a buried well electrode 86 is connected to the buried well 84 . The buried polysilicon 80 is made of n-type polysilicon (polycrystalline silicon) as described below. The buried well 84 is a semiconductor region formed by injecting a p-type impurity into the first semiconductor layer 10 as described below. In some cases, the buried well 84 has a contact region (not shown in the figure), to which a high-concentration p-type impurity has been injected, in a region that includes the interface with the buried well electrode 86 .
[0030] FIG. 2 is a plan view of the charge-attracting part 60 . As shown in FIG. 2 , the buried polysilicon 80 has two regions that are separated from the transistor 51 in the gate width direction of the transistor 51 (direction indicated with the arrow W in FIG. 2 ) and that extend in the gate length direction (direction indicated with the arrow L in FIG. 2 ). The buried well 84 is formed so as to include the transistor 51 and the buried polysilicon 80 in a plan view.
[0031] Next, one example of the bias method in using the semiconductor device 100 will be explained with reference to FIG. 1 again. In order to detect X-ray in the semiconductor device 100 , a reverse bias voltage is applied to the photodiode 11 , thereby depleting the first semiconductor layer 10 . That is, in order to detect X-ray in the semiconductor device 100 , the rear electrode 14 and the cathode electrode 75 are connected to the positive electrode of a power source 200 , and the anode electrode 74 is connected to the negative electrode of the power source 200 , which is connected to the ground potential. The reverse bias voltage applied to the photodiode 11 , or in other words, the voltage of the power source 200 , is several hundred volts, for example. On the other hand, the source and drain electrodes 72 connected to the source and drain regions 52 of the transistor 51 are connected to the positive electrode of a power source 202 . The voltage applied to the source and drain regions, or in other words, the voltage of the power source 202 is several volts, which is 3.3 V or smaller, for example.
[0032] In the semiconductor device 100 , the buried polysilicon electrode 82 connected to the buried polysilicon 80 of the charge-attracting part 60 and the buried well electrode 86 connected to the buried well 84 are connected to the negative electrode of the power source 200 .
[0033] Next, the operation of the charge-attracting part 60 when the semiconductor device 100 biased in the manner described above is activated will be explained with reference to FIG. 3 .
[0034] When a prescribed bias voltage is applied, a depletion layer is generated in the first semiconductor layer 10 based on the difference in potential between the anode 12 and the cathode 13 of the photodiode 11 . If X-ray is incident on the semiconductor device 100 in this state, electron-hole pairs are generated in the first semiconductor layer 10 of the photodiode 11 , and the generated electrons are attracted to the cathode 13 , and the generated holes are attracted to the anode 12 . The electrons and holes are then taken out and observed.
[0035] When X-ray is incident on the semiconductor device 100 and electron-hole pairs are generated in insulating layers (first insulating layer 20 and second insulating layer 40 ) due to the phenomenon described above, positive charges PC might be trapped in the insulating layer as shown in FIG. 3 . As the amount of incident X-ray increases, the amount of trapped positive charges also increases, and the accumulated charges in the insulating layer could adversely affect the operation of the transistor 51 .
[0036] In order to solve this problem, in the semiconductor device 100 of this embodiment, a potential (ground potential in this embodiment) lower than the potential applied to the source and drain regions 52 of the transistor 51 (about +3.3V, for example) is applied to the buried polysilicon 80 . Thus, the positive charges PC generated in the insulating layer due to the radiation of X-ray are attracted to the buried polysilicon 80 , which reduces the amount of the positive charges PC below the transistor 51 , in particular. By reducing the amount of positive charges PC near the transistor 51 , the degree of characteristic change of the transistor 51 can be suppressed.
[0037] The semiconductor device 100 of this embodiment is configured to have the p-type buried well 84 applied with a potential lower than the potential applied to the source and drain regions 52 of the transistor 51 , and a depletion layer is formed in the PN junction at the interface between the buried well 84 and the first semiconductor layer 10 . Thus, the potential of the buried well 84 is not affected by the bias voltage applied to the first semiconductor layer 10 via the rear electrode 14 , and is maintained at the same potential as that of the negative electrode side of the power source 200 , which is applied to the buried well 84 (ground potential in this embodiment). This makes it possible for the buried polysilicon 80 to attract the positive charges PC efficiently. In this embodiment, the semiconductor device 100 does not necessarily have to have the buried well 84 , and it is possible to attract the positive charges PC by the buried polysilicon 80 alone depending on the radiation amount of X-ray and the like.
[0038] As described above, the buried well 84 is formed so as to include the buried polysilicon 80 (so as to extend to the outer periphery of the buried polysilicon 80 ) in a plan view. When the buried well 84 is not formed between the buried polysilicon 80 and the first semiconductor layer 10 , it is necessary to ensure a withstand voltage that at least corresponds to the voltage of the power source 200 between the buried polysilicon 80 and the first semiconductor layer 10 , and in order to ensure this withstand voltage, an oxide film having a sufficient thickness needs to be provided, for example. In other words, it is possible to omit the buried well 84 as long as an oxide film that can ensure such a withstand voltage can be formed.
[0039] Next, one example of the manufacturing method of the semiconductor device 100 will be explained with reference to FIGS. 4 to 6 . FIGS. 4 to 6 are vertical cross-sectional views showing the manufacturing method of the semiconductor device 100 .
[0040] First, an SOI substrate 1 in which a first semiconductor layer 10 made of an n-type semiconductor, a first insulating layer 20 , and a second semiconductor layer 20 made of a p-type semiconductor are stacked in this order is prepared ( FIG. 4A ).
[0041] Next, a field oxide film 90 is formed in the second semiconductor layer 30 by the LOCOS (local oxidation of silicon) method. The portion of the second semiconductor layer 30 where the field oxide film 90 is not formed is an active region 30 A in which a circuit element such as a transistor is to be formed ( FIG. 4B ).
[0042] Next, the first insulating layer 20 and the field oxide film 90 are etched by photolithography, for example, so as to expose the first semiconductor layer 10 and form openings 91 that reach the first semiconductor layer 10 in regions where a buried polysilicon 80 is to be formed ( FIG. 4C ). The width of the openings 91 is approximately 0.5 μm, for example, and the openings 91 are formed at positions that are approximately 0.3 μm from the active region 30 A, for example.
[0043] Next, the oxidation process is conducted on exposed areas O of the first semiconductor layer 10 , thereby forming an SiO 2 film having a thickness of approximately 10 nm on the surface of the first semiconductor layer 10 . This oxide film is an insulating film to provide insulation between the first semiconductor layer 10 and the buried polysilicon 80 , which will be formed later, and is formed to allow different potentials (several V, for example) to be applied to the buried polysilicon 80 and to the first semiconductor layer 10 , respectively. It is apparent that the formation method of the insulating film is not limited to this. It is also possible to partially remove the first insulating layer 20 in the etching process described above so that a portion thereof remains with a thickness of approximately 10 nm.
[0044] Next, the openings 91 are filled by the CVD (chemical vapor deposition) method using polysilicon, and thereafter, by etching back the deposited polysilicon, the thickness of the polysilicon is adjusted so that the top surface of the polysilicon is above the openings 91 ( FIG. 4D ). In this embodiment, doped polysilicon, which has an impurity doped therein in advance, is used for the polysilicon for forming the buried polysilicon 80 . The doped polysilicon is polysilicon that contains an n-type impurity at a high concentration (approximately 1×10 20 cm −3 , for example), which is formed by supplying a gas including an n-type impurity (P (phosphorus), for example)) during the CVD process using polysilicon.
[0045] Next, a gate oxide film 92 is formed in a region including the surface of the active region 30 A. Then, a region other than a buried well 84 forming region in the first semiconductor layer 10 is entirely covered by a photoresist R and a p-type impurity such as B (boron) is injected, thereby forming the buried well 84 ( FIG. 5A ). In this process, the impurity concentration of the buried well 84 is set to approximately 1×10 17 cm −3 , for example.
[0046] Next, a polysilicon film is deposited on the gate oxide film 92 , and by patterning the polysilicon film by photolithography, a gate electrode 55 is formed ( FIG. 5B ).
[0047] Next, a side wall 56 is formed on each side of the gate electrode 55 . Thereafter, an impurity containing a group V element such as phosphorus or arsenic is injected into the active region 30 A in the second semiconductor layer 30 by the ion injection method, thereby forming source and drain regions 52 made of a high concentration n-type semiconductor at the respective sides of the gate electrode 55 . This way, the transistor 51 is formed ( FIG. 5C ).
[0048] Next, by dry-etching, openings 93 and 94 that respectively reach the first semiconductor layer 10 through the field oxide film 90 and the first insulating layer 20 are formed ( FIG. 5D ). If a contact region is to be formed in the buried well 84 , an opening that reaches the buried well 84 is also formed in this process.
[0049] Next, by injecting an impurity containing a group V element such as phosphorus or arsenic to a portion of the first semiconductor layer 10 that is exposed in the opening 94 by the ion injection method, a cathode 13 made of a high concentration n-type semiconductor is formed on the surface of the first semiconductor layer 10 . Next, by injecting an impurity containing a group III element such as boron to a portion of the first semiconductor layer 10 that is exposed in the opening 93 by the ion injection method, an anode 12 made of a high concentration p-type semiconductor is formed on the surface of the first semiconductor layer 10 ( FIG. 6A ). If a contact region is to be formed in the buried well 84 , an impurity containing a group III element such as boron is injected into a portion exposed in an opening formed in the preceding process.
[0050] Next, by the CVD method, a second insulating layer 40 is formed of an insulator such as an SiO 2 film so as to cover the second semiconductor layer 30 where the circuit element including the transistor 51 is formed. The openings 93 and 94 formed in the preceding process are filled by the second insulating layer 40 ( FIG. 6B ).
[0051] Next, openings 99 that reach the source and drain regions 52 through the second insulating layer 40 and openings 98 that reach the buried polysilicon 80 through the second insulating layer 40 are formed by dry-etching. Also, an opening 97 that reaches the buried well 84 formed in the first semiconductor layer 10 through the second insulating layer 40 , the field oxide film 90 , and the first insulating layer 20 is formed by dry-etching. Furthermore, openings 95 and 96 that reach the anode 12 and cathode 13 formed in the first semiconductor 10 , respectively, are formed through the second insulating layer 40 , the field oxide film 90 , and the first insulating layer 20 by dry-etching ( FIG. 6C ).
[0052] Next, a metal such as aluminum is deposited on the surface of the second insulating layer 40 by spattering. The openings 95 , 96 , 97 , 98 , and 99 are filled by this metal. Thereafter, this metal is patterned into a desired shape. This way, source and drain electrodes 72 connected to the source and drain regions 52 , buried polysilicon electrodes 82 connected to the buried polysilicon 80 , a buried well electrode 86 connected to the buried well 84 , an anode electrode 74 connected to the anode 12 , and a cathode electrode 75 connected to the cathode 13 are formed. Next, a rear electrode 14 is formed on the rear surface of the first semiconductor layer 10 by spattering ( FIG. 6D ).
[0053] The semiconductor device 100 of this embodiment is manufactured by the manufacturing method described above.
Embodiment 2
[0054] A semiconductor device 100 a of this embodiment will be explained with reference to FIG. 7 . FIG. 7 is a plan view showing a charge-attracting part 60 a of the semiconductor device 100 a . The semiconductor device 100 a differs from the semiconductor device 100 in the shape of the buried polysilicon 80 . Thus, the same configurations as those of the semiconductor device 100 are given the same reference characters, and the detailed descriptions thereof will be omitted.
[0055] As shown in FIG. 7 , the position in the gate width direction relative to the transistor 51 and the width of the buried polysilicon 80 a of the charge-attracting part 60 a of this embodiment are similar to those of the buried polysilicon 80 , but the buried polysilicon 80 a differs from the buried polysilicon 80 in that the buried polysilicon 80 a is formed to surround the transistor 51 .
[0056] In the semiconductor device 100 in which the buried polysilicon 80 has two regions separated from each other in the gate width direction of the transistor 51 , if the gate width of the gate electrode 55 is great, a distance between the center of the transistor 51 and the buried polysilicon 80 would be longer, which possibly makes it difficult to efficiently attract the positive charges PC generated near the center of the transistor 51 . In order to solve this problem, in this embodiment, the buried polysilicon 80 a is formed so as to surround the transistor 51 . With this configuration, the positive charges PC generated near the center of the transistor 51 can be attracted in the gate length direction (direction indicated with the arrow L in FIG. 7 ), and therefore, it is possible to make the positive charges PC attracted to the buried polysilicon more efficiently.
Embodiment 3
[0057] A semiconductor device 100 b of this embodiment will be explained with reference to FIG. 8 . FIG. 8 is a vertical cross-sectional view showing an example of the configuration of the semiconductor device 100 b . The semiconductor device 100 b differs from the semiconductor device 100 in that a double-SOI (double-silicon on insulator) substrate is used for the substrate and that a fixed potential region is formed using an intermediate semiconductor layer instead of the fixed potential region by the buried well 84 of the semiconductor device 100 . Thus, the same configurations as those of the semiconductor device 100 are given the same reference characters, and the detailed descriptions thereof will be omitted.
[0058] In the double-SOI substrate, a first semiconductor layer 10 made of an n-type semiconductor, a first insulating layer 20 , an intermediate semiconductor layer 32 , a third insulating layer 42 , and a second semiconductor layer 30 made of a p-type semiconductor are stacked in this order.
[0059] The intermediate semiconductor layer 32 made of an n-type semiconductor is formed between the first semiconductor layer 10 having the photodiode 11 formed therein and the second semiconductor layer 30 having the circuit element such as the transistor 51 formed therein. Between the intermediate semiconductor layer 32 and the first semiconductor layer 10 , the first insulating layer 20 made of an insulator such as an SiO 2 film is formed, and between the intermediate semiconductor layer 32 and the second semiconductor layer 30 , the third insulating layer 42 made of an insulator such as an SiO 2 film is formed.
[0060] The intermediate semiconductor layer 32 includes a contact region 88 made of an n-type semiconductor that has a higher concentration than that of the intermediate semiconductor layer 32 . The contact region 88 is connected to an intermediate semiconductor layer electrode 89 , and the intermediate semiconductor layer electrode 89 is connected to the negative electrode of the power source 200 . In the semiconductor device 100 b , the charge-attracting part 60 b is constituted of the buried polysilicon 80 and the intermediate semiconductor layer 32 . The buried polysilicon 80 of this embodiment may have two regions that are separated from the transistor 51 in the gate width direction of the transistor 51 and that extend in the gate length direction as shown in FIG. 2 , or may be formed so as to surround the transistor 51 as shown in FIG. 7 .
[0061] As shown in FIG. 8 , in the semiconductor device 100 b , the potential applied to the intermediate semiconductor layer 32 disposed below the transistor 51 is adjusted so as to cancel the positive charges PC accumulated in the insulating layer (mainly the third insulating layer 42 ). This makes it possible to further suppress the characteristic change of the transistor 51 .
[0062] The semiconductor device 100 b of this embodiment can be manufactured according to the manufacturing method of the semiconductor device 100 shown in FIGS. 4 to 6 . The manufacturing method thereof will be briefly explained below.
[0063] First, a double-SOI substrate is prepared by stacking a first semiconductor layer 10 made of an n-type semiconductor, a first insulating layer 20 , an intermediate semiconductor layer 32 , a third insulating layer 42 , and a second semiconductor layer 30 made of a p-type semiconductor in this order (see FIG. 4A for reference).
[0064] Next, a field oxide film is formed in the second semiconductor layer 30 by the LOCOS method. The portion of the second semiconductor layer 30 where the field oxide film is not formed is an active region in which a circuit element such as a transistor is to be formed (see FIG. 4B for reference).
[0065] Next, the field oxide film, which was formed in the preceding process, and the first insulating layer 20 are etched by photolithography, for example, so as to expose the intermediate semiconductor layer 32 and form openings that reach the intermediate semiconductor layer 32 in regions where a buried polysilicon 80 is to be formed (see FIG. 4C for reference).
[0066] Next, the oxidation process is conducted on the exposed areas of the intermediate semiconductor layer 32 , the openings are filled by the CVD method using doped polysilicon, and the thickness of the polysilicon is adjusted by etching back the deposited polysilicon (see FIG. 4D for reference).
[0067] Next, after forming a gate oxide film in a region that includes the surface of the active region, a polysilicon film is deposited on the gate oxide film, and by patterning the polysilicon film by photolithography, a gate electrode 55 is formed (see FIG. 5B for reference).
[0068] Next, a side wall is formed on each side of the gate electrode 55 . Next, by injecting an impurity containing a group V element such as phosphorus or arsenic to the active region of the second semiconductor layer 30 by the ion injection method, source and drain regions 52 made of a high-concentration n-type semiconductor are formed at the respective sides of the gate electrode. This way, the transistor 51 is formed (see FIG. 5C for reference).
[0069] Next, an opening for forming a contact region 88 is formed so as to reach the intermediate semiconductor layer 32 through the field oxide film and the third insulating layer 42 by dry-etching. Also, openings for forming an anode 12 and a cathode 13 are formed so as to reach the first semiconductor layer 10 through the field oxide film, the third insulating layer 42 , the intermediate semiconductor layer 32 , and the first insulating layer 20 by dry-etching (see FIG. 5D for reference).
[0070] Next, by injecting an impurity containing a group V element such as phosphorus or arsenic to a portion of the intermediate semiconductor layer 32 that is exposed in the opening by the ion injection method, the contact region 88 made of a high concentration n-type semiconductor is formed on the surface of the intermediate semiconductor layer 32 .
[0071] Next, by injecting an impurity containing a group V element such as phosphorus or arsenic to a portion of the first semiconductor layer 10 that is exposed in the opening by the ion injection method, a cathode 13 made of a high concentration n-type semiconductor is formed on the surface of the first semiconductor layer 10 . Thereafter, by injecting an impurity containing a group III element such as boron to a portion of the first semiconductor layer 10 that is exposed in the opening by the ion injection method, an anode 12 made of a high concentration p-type semiconductor is formed on the surface of the first semiconductor layer 10 (see FIG. 6A for reference).
[0072] Next, by the CVD method, a second insulating layer 40 is formed of an insulator such as an SiO 2 film so as to cover the second semiconductor layer 30 where the circuit element including the transistor 51 is formed. The openings formed in the preceding process are filled by the second insulating layer 40 (see FIG. 6B for reference).
[0073] Next, openings that reach the source and drain regions 52 through the second insulating layer 40 and openings that reach the buried polysilicon 80 through the second insulating layer 40 are formed by dry-etching. Also, an opening that reaches the contact region 88 formed in the intermediate semiconductor layer 32 is formed through the second insulating layer 40 , the field oxide film, and the third insulating layer 42 by dry-etching. Furthermore, openings that reach the anode 12 and the cathode 13 formed in the first semiconductor 10 , respectively, are formed through the second insulating layer 40 , the field oxide film, the third insulating layer 42 , and the first insulating layer 20 by dry-etching (see FIG. 6C for reference).
[0074] Next, a metal such as aluminum is deposited on the surface of the second insulating layer 40 by spattering. The openings formed in the preceding process are filled by this metal. Thereafter, this metal is patterned into a desired shape. This way, source and drain electrodes 72 connected to the source and drain regions 52 , buried polysilicon electrodes 82 connected to the buried polysilicon 80 , an intermediate semiconductor layer electrode 89 connected to the contact region 88 , an anode electrode 74 connected to the anode 12 , and a cathode electrode 75 connected to the cathode 13 are formed. Next, a rear electrode 14 is formed on the rear surface of the first semiconductor layer 10 by spattering (see FIG. 6D for reference).
[0075] The semiconductor device 100 b of this embodiment is manufactured by the manufacturing method described above.
[0076] In the embodiments described above, the buried polysilicon and the fixed potential region (buried well 84 and intermediate semiconductor layer 32 ) are connected to the negative electrode of the power source 200 , or in other words, to the ground, but the present invention is not limited to this configuration. A different power source from the power source 200 may be connected to the buried polysilicon and the fixed potential region so that a potential is applied independently of the power source 200 , or a negative potential may be applied. The buried polysilicon and the fixed potential region do not necessarily have to have the same potential, and different levels of potential may be applied to the buried polysilicon and the fixed potential region, respectively.
|
A semiconductor device includes a first semiconductor layer of a first conductivity type having a primary surface on one side thereof and a secondary surface on an opposite side thereof, and having a sensor therein, a second semiconductor layer of a second conductivity type having a circuit element formed therein, the second semiconductor layer being formed at said one side of the primary surface of the first semiconductor layer, an insulating layer formed between the first semiconductor layer and the second semiconductor layer, and being disposed on the primary surface of the first semiconductor layer, and a charge-attracting semiconductor layer of the first conductivity type configured to attract electrical charges generated in the insulating layer when a fixed voltage is supplied to the charge-attracting semiconductor layer.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of U.S. Provisional Patent Application Ser. No. 60/869,590, filed Dec. 12, 2006, which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of this invention relate generally to systems used to cool computer hardware and more particularly to an adaptor for a graphics module.
2. Description of the Background Art
FIG. 1 is an isometric view illustrating a prior art cooling system 100 used to cool a heat-generating electronic device, such as a graphics processing unit (GPU), in a computer. As shown, cooling system 100 characteristically includes a blower/fan 106 , fins 109 and a bottom plate 111 . Typically, cooling system 100 is thermally coupled to the GPU, for example using thermal adhesive or grease having thermal properties that facilitate transferring heat generated by the GPU to the bottom plate 111 . Cooling system 100 may also include a heat sink lid (not shown), which, among other things, prevents particles and other contaminants from entering blower/fan 106 and air blown from blower/fan 106 from escaping cooling system 100 . The heat sink lid, together with the fins 109 and the bottom plate 111 , define a plurality of air channels 108 .
Blower/fan 106 is configured to force air through air channels 108 over bottom plate 111 such that the heat generated by the GPU transfers to the air. The heated air then exits cooling system 100 , as depicted by flow lines 114 , thereby dissipating the heat generated by the GPU into the external environment. This process cools the GPU, preventing the device from overheating during operation. Air channels 108 are configured to direct air blown from blower/fan 106 over bottom plate 111 and into the external environment in a manner that most efficiently removes heat from the GPU.
FIG. 2 is a schematic diagram illustrating a prior art computer 200 , such as a desktop, laptop, server, mainframe, set-top box, cellular phone, personal digital assistant (PDA) and the like within which the cooling system 100 for cooling the GPU 216 is incorporated. As shown, computer 200 includes a housing 201 , within which a motherboard 204 resides. Mounted on motherboard 204 are a central processing unit (CPU) 206 , a processor cooler 208 for cooling CPU 206 , and one or more peripheral component interface (PCI) cards 212 , each interfaced with a slot located in the back part of housing 201 . A system fan 210 is attached to the housing 201 for removing heat from computer 200 . Motherboard 204 further incorporates a graphics card 202 that enables computing device 200 to rapidly process graphics related data for graphics intensive applications such as gaming applications. Graphics card 202 includes a printed circuit board (PCB) upon which a plurality of circuit components (not shown), such as memory chips and the like, are mounted. In addition, graphics card 200 includes GPU 216 , mounted to one face of graphics card 202 , for processing graphics related data.
Because the computational requirements of GPU 216 are typically quite substantial, GPU 216 tends to generate a large amount of heat during operation. If the generated heat is not properly dissipated, the performance of GPU 216 degrades. For this reason, cooling system 100 , which is configured to remove heat from GPU 216 , is coupled to GPU 216 .
FIG. 3 is a schematic diagram illustrating a prior art computer 305 having an alternative cooling system 300 incorporated therein. Cooling system 300 is coupled to graphics card 302 in order to dissipate heat generated by the GPU 316 and other surface mounted components (not shown). Cooling system 300 is interfaced to graphics card 302 via a mounting plate 320 that is adapted for coupling to mounting holes on graphics card 302 . Cooling system 300 further includes a passive heat transport device 315 , such as a heat pipe, and a heat exchanger 325 coupled to GPU 316 using mounting plate 320 . The heat pipe 315 is a passive heat transfer device, employing two-phase flow to achieve an extremely high thermal conductivity. The heat pipe 315 includes a vapor chamber and a wick structure which draws liquid (e.g. water) to a heat source (provided by the heat generated by the GPU 316 and transferred through the base 320 ) by the use of capillary forces. The liquid evaporates in the wick when heated and the resulting vapor escapes to the vapor chamber of the heat pipe where the vapor is then forced by a resulting pressure gradient to cooler regions of the heat pipe for condensation. The condensed liquid is then returned to the heat source via the capillary action. The cooler region of the heat pipe 315 is in thermal communication with a system fan 310 via heat exchanger 325 .
Each of the graphics cards 202 , 302 is modular, thereby having a standard connector that interfaces with a mating standard connector of a respective motherboard 204 , 304 . The configuration of the standard connector is governed by a standard, such as peripheral component interface express (PCI Express), mobile PCI Express module (MXM), peripheral component interface (PCI), and Accelerated Graphics Port (AGP). A modular graphics card allows for a user to upgrade the graphics card for a particular computer and/or allows an original equipment manufacturer (OEM) to offer different graphics cards for a particular computer.
Even though a particular graphics card complies with a particular standard, there is still substantial variation between graphics cards from different vendors and even different graphics cards from the same vendor. Parameters, such as placement of the GPU and/or memory units on a graphics card, dimensions of the graphics card, number of memory units, location of power supply, components that require cooling, height of components, etc., will vary such that one particular cooling system configured for a particular graphics card will not interface with another graphics card complying with the same standard. Therefore, if the graphics card for a particular computer is upgraded, then the cooling system for that graphics card must also be replaced. Replacement of the cooling system is cumbersome especially in small form factor computers, such as servers, laptops, and PDAs, where the cooling systems are very compact to accommodate limited space availability. Further, when a new graphics card is designed by a particular vendor, a new or substantially re-configured cooling system must also be designed.
As the foregoing illustrates, what is needed in the art is a standard interface between a graphics card and a cooling system.
SUMMARY OF THE INVENTION
Embodiments of this invention relate generally to systems used to cool computer hardware and more particularly to an adaptor for a graphics module. In one embodiment a graphics card assembly is provided. The graphics card assembly includes a printed circuit board (PCB); a graphics processing unit (GPU) attached to the PCB; and an adaptor having first and second surfaces and made from a thermally conductive material. The adaptor is disposed on the PCB so that the first surface is in thermal communication with the GPU and the second surface providing a standard interface for thermal communication with a cooling system.
The standard interface of the adaptor allows for various graphics cards to be used with a standard cooling system without custom configuration of the cooling system. The adaptor is customized for a particular graphics card instead of having to customize the base of the cooling system. The standard interface provided by the adaptor simplifies graphics card installation, simplifies cooling system design, and eliminates customization of a particular cooling system for a particular graphics card.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view illustrating a prior art system used to cool a processor.
FIG. 2 is schematic diagram illustrating a prior art computing device adapted for use with the cooling system of FIG. 1 .
FIG. 3 is a schematic diagram illustrating a prior art computer having an alternative cooling system incorporated therein.
FIG. 4 is an exploded isometric view of a modular graphics card assembly and a portion of a cooling system for transferring heat from the graphics card assembly, according to one embodiment of the present invention.
FIG. 4A is a plan view of a first surface of the adaptor of FIG. 4 .
FIG. 4B is a plan view of a second surface of the adaptor of FIG. 4 .
FIG. 5 is an exploded isometric view of a modular graphics card assembly and a cooling system for transferring heat from the graphics card assembly, according to another embodiment of the present invention.
FIG. 5A is a plan view of a first surface of the adaptor of FIG. 5 .
FIG. 5B is a plan view of a second surface of the adaptor of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 4 is an exploded isometric view of a modular graphics card assembly 400 and a portion of a cooling system 450 for transferring heat from the graphics card assembly 400 , according to one embodiment of the present invention. The graphics card assembly 400 includes a graphics card 405 and an adaptor 410 . FIG. 4A is a plan view of a first surface 410 a of the adaptor 410 . FIG. 4B is a plan view of a second surface 410 b of the adaptor 410 . The graphics card 405 includes a PCB 402 , a GPU 406 attached to the PCB 402 , one or more memory units 407 a - d attached to the GPU 406 , and a connector 403 formed as part of the PCB 405 . The connector 403 interfaces with a mating connector of a motherboard (not shown) of a computer (not shown). One or more fasteners, such as screws 404 , may be provided and are received by respective standoffs (not shown) on the motherboard. As shown, the adaptor plate 410 and the graphics card 405 conform to the MXM standard, disclosed in the '590 Provisional. Alternatively, the adaptor plate 410 may be configured to conform to any standard for modular graphics cards, such as those listed above.
The adaptor 410 is made from a thermally conductive material, such as aluminum, copper, and alloys thereof. The adaptor 410 is mechanically coupled to the PCB 402 so that the first surface 410 a of the adaptor is in thermal communication with the GPU 406 and the memory units 407 a - d by one or more fasteners, such as screws 430 . Disposed on each screw 430 is a biasing member, such as a spring 430 a . Each screw is received in a respective hole 414 a formed through the adaptor 410 , a respective hole 409 formed through the PCB, and a respective threaded standoff (not shown) disposed through a hole formed through a back 435 , thereby coupling the adaptor 410 , the PCB 402 , and the back 435 together. Alternatively, the back 435 may be omitted and each of the screws 430 may instead have toggled ends. Each spring 430 a abuts a head of a respective screw 430 at one end and is received in a recess 414 b formed in the second surface 410 b of the adaptor 410 at the other end. A bushing or standoff 414 c may line each of the holes 414 a . The springs allow the adaptor 410 to float over the PCB 402 to ensure optimal thermal communication between the adaptor 410 and the GPU 406 and the memory units 407 a - d.
The adaptor 410 includes a central portion and one or more optional extended portions 412 a, b . The central portion includes a thermal transfer area (TTA) 418 , which may vary according to a particular standard. Whether to include the extended portions 412 a, b will be based on the cooling requirements of the particular graphics card 405 . For example, an economical graphics card may only require cooling of the GPU whereas a more powerful graphics card may require cooling of the GPU and memory units and an even more powerful graphics card may require cooling of the GPU, the memory units, and one or more other components, such as a power supply. The central portion includes a recess 415 which receives the GPU 406 and the extended portions 412 a, b and pads 416 a - d extending from the first surface 410 a for contacting the memory units 407 a - d . The recess 415 and the pads 416 a - d compensate for height variations between the GPU 406 and the memory units 407 a - d and may be specifically configured for a particular graphics card.
The adaptor 410 may further include one or more cutout portions 419 a, b . The cutout portions allow access to the motherboard screws 404 . The cutout portion 419 a also provides vertical space for a relatively tall component 408 of the graphics card 405 . The vertical space provided by the cutout portion 408 also minimizes the required thickness of the adaptor 410 , thereby also minimizing thermal resistance added by the adaptor 410 . The height of the component 408 may exceed the height of the second surface 410 b ; however, if so, then the component 408 may be located at a side of the graphics card 402 opposite the connector 403 to allow flexibility in choosing a coupling mode (discussed below).
The cooling system 450 includes a base 455 , an insert 475 , an L-shaped heat pipe 460 , and a heat exchanger, such as an array of fins 465 . Alternatively, the cooling system 550 (see FIG. 5 ) may be used instead. The insert 475 is made from a thermally conductive material and is received in a window 457 formed through the base 455 . Alternatively, the base 455 and the insert 475 may be formed as one integral member. The base 455 is mechanically coupled to the adaptor 410 so that the insert 470 is in thermal communication with the TTA 418 of the second surface 410 b of the adaptor 410 by one or more fasteners, such as screws 470 . Disposed on each screw 470 is a biasing member, such as a spring 470 a . Each screw 470 is received in a respective hole 417 formed through the adaptor 410 , and a respective hole 401 formed in the PCB 402 , thereby coupling the base 455 , the adaptor 410 , and the PCB 402 together. A bushing or standoff 401 a may line each of the holes 401 and a bushing or standoff 417 a may line each of the holes 417 . Each spring 470 a abuts a head of a respective screw 470 at one end and is received in a recess 457 a formed in a second surface of the base 455 at the other end. The springs allow the base 455 to float on the adaptor 410 to ensure optimal thermal communication between the base 455 and the adaptor 410 .
Various alternative modes of coupling the adaptor to the base 455 may be used besides fasteners. The adaptor 410 includes one or more ears 413 formed at opposing sides thereof. In one of these alternative modes, the base 455 includes a clip (not shown) so that the adaptor ears 413 may actuate the clip open upon insertion into the computer. The clip would then be closed, thereby coupling the adaptor to the base. In another of these alternative modes, a chassis (not shown) of the computer includes a slot, similar to a PC Card (formerly PCMCIA card). A chamfer 413 a of each of the ears 413 allows for the graphics card assembly 400 to slide along the first surface of the base 455 until the second surface 410 b of the adaptor 410 aligned with the first surface of the base 455 . In another of these alternative modes, the base 455 includes extensions (not shown) at opposing sides thereof each of which has a rail formed therein. The ears 413 would then be slid along the rails until the second surface 410 b of the adaptor 410 aligned with the first surface of the base 455 . In another of these alternative modes, the graphics card assembly 400 would be inserted into the computer until the second surface 410 b of the adaptor 410 aligned with the first surface of the base 455 and then a slide (not shown) is then moved over each ear 413 and locked into place.
A portion of a first leg of the heat pipe 460 is received in a recess 456 formed in a second surface of the base 455 , thereby providing thermal communication between the insert 475 and the heat pipe 460 . A portion of a second leg of the heat pipe 460 is received in a recess formed in a first surface of the fin array 465 . The fin array 465 is attached to the computer chassis in fluid communication with a system fan (not shown).
FIG. 5 is an exploded isometric view of a modular graphics card assembly 500 and a cooling system 550 for transferring heat from the graphics card assembly 500 , according to another embodiment of the present invention. The graphics card assembly 500 includes a graphics card 505 and an adaptor 510 . FIG. 5A is a plan view of a first surface 510 a of the adaptor 510 . FIG. 5B is a plan view of a second surface 510 b of the adaptor 510 . Mounting of the adaptor 510 to the graphics card 505 and connection of the graphics card 505 to the motherboard is similar to that of the FIG. 4 embodiment, discussed above. As shown, the adaptor plate 510 and the graphics card 505 conform to the MXM standard, disclosed in the '590 Provisional. Alternatively, the adaptor plate 510 may be configured to conform to any standard for modular graphics cards, such as those listed above.
The adaptor 510 is made from a thermally conductive material, such as aluminum, copper, and alloys thereof. The adaptor 510 includes a central portion and one or more optional extended portions 512 a,b . The central portion includes a thermal transfer area (TTA) 518 , which may vary according to a particular standard. Whether to include the extended portions 512 a,b will be based on the cooling requirements of the particular graphics card 505 , as discussed above. The central portion includes a recess 515 which receives the GPU 506 and the extended portions 512 a, b and pads 516 a - d extending from the first surface 510 a for contacting the memory units 507 a - d . The extended portion 512 b further includes one or more pads 520 a - d for contacting components 540 a - d , respectively, and/or one or more recesses 521 a - e for receiving components 545 a - e , respectively, thereby providing thermal communication between these components and the adaptor. These components may be, for example, part of a power supply or other graphics card components. In one embodiment, component 540 a is a portion of a power supply. The recesses and the pads compensate for height variations between the GPU, memory units, and the other components and may be specifically configured for a particular graphics card.
The adaptor 510 may further include a window 519 a and/or one or more cutout portions 519 b - e . The window 519 a and the cutout portions 519 b, c provide vertical space for relatively tall components 508 a - c , respectively, of the graphics card 505 , as discussed above. Each of the cutout portions 519 d, e allow access to one of the motherboard screws 504 .
The cooling system 550 includes a base 555 , a side 558 , an array of fins 565 , a fan 560 , and a lid 562 . Alternatively, the cooling system 450 may be used instead. Note that, because of the adaptors 410 , 510 , the cooling systems 450 , 550 may be interchanged without modification thereto, discussed below. The base 555 is made from a thermally conductive material and includes a pad 575 formed therein and extending from a first surface thereof. Alternatively, the pad 575 may be an insert. The base 555 is mechanically coupled to the adaptor 510 so that the pad 575 is in thermal communication with the TTA 518 of the second surface 510 b of the adaptor 510 by one or more fasteners, such as screws 570 . Disposed on each screw is a biasing member, such as a spring 570 a . Each screw 570 is received in a respective threaded hole 517 disposed through the adaptor 510 , thereby coupling the base 555 and the adaptor 510 together. Each of the holes 517 may be lined with a bushing or standoff 517 a . Each spring 570 a abuts a head of a respective screw 570 at one end and is received in a recess 557 a formed in a second surface of the base 555 at the other end. The springs 570 a allow the base 555 to float on the adaptor 510 to ensure optimal thermal communication between the base 555 and the adaptor 510 .
The fin array 565 is mechanically coupled to the base 555 so that the fin array 565 is in thermal communication with the base 555 . The fan 560 includes a motor (not shown) and is coupled to the base 555 so that the fan 560 may rotate relative to the base 555 and be in fluid communication with the fin array 565 . The side 558 is coupled to the base 555 and the lid 562 is coupled to the side 558 so that air impelled by the fan is directed through the fin array 565 . A hole is formed through the lid 562 to provide an inlet for the air. An outlet is formed in the side 558 to allow airflow to exit the cooling system 550 .
The TTAs 418 , 518 and/or second surfaces 410 b , 510 b of the adaptors 410 , 510 each provide a standard interface for a cooling system, such as the cooling system 450 or 550 . As long as a base/insert of the cooling system is configured to be placed in thermal communication with the TTA 418 or 518 , the parameters discussed above may be varied without custom configuration of the cooling system. In some embodiments, the second surface of each of the adaptors 410 , 510 provides a flat or substantially flat surface for mating with a base of the cooling system. Each of the first surfaces 410 a , 510 a of the adaptors 410 , 510 is customized for a particular graphics card instead of having to customize the base of the cooling system. The standard interface provided by the adaptor simplifies graphics card installation, simplifies cooling system design, and eliminates customization of a particular cooling system for a particular graphics card.
Although the invention has been described above with reference to specific embodiments, persons skilled in the art will understand that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The foregoing description and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
|
Embodiments of this invention relate generally to systems used to cool computer hardware and more particularly to an adaptor for a graphics module. In one embodiment a graphics card assembly is provided. The graphics card assembly includes a printed circuit board (PCB); a graphics processing unit (GPU) attached to the PCB; and an adaptor having first and second surfaces and made from a thermally conductive material. The adaptor is disposed on the PCB so that the first surface is in thermal communication with the GPU and the second surface providing a standard interface for thermal communication with a cooling system.
| 6
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to apparatus for detecting digital data and, more particularly, is directed to an apparatus for detecting digital data for use in a video tape recorder (VTR) which uses Class IV or other partial response signalling in high density digital tape recording and reproducing.
2. Description of the Prior Art
So-called digital video tape recorders have been developed to record a video signal in the form of a digital signal on a magnetic tape and, with such digital VTRs, the deterioration of image quality in the dubbing mode can be suppressed to a minimum.
Incidentally, when a signal is recorded on and/or reproduced from a magnetic tape, the electromagnetic transducing system used therefor, such as, a magnetic head or the like, has a differentiation characteristic so that the C/N (carrier-to-noise) ratio is deteriorated at the lower frequency side. The C/N ratio will be similarly deteriorated due to a magnetization characteristic of the magnetic tape itself, shown in FIG. 1, if the frequency is increased.
Accordingly, when using a magnetic recording and/or reproducing system for a digitized video signal (hereinafter, referred to as a digital video signal), the frequency band in which a satisfactory C/N ratio can be obtained is relatively narrow. For this reason, when a digital video signal is to be detected, a detection system is employed having a signal spectrum concentrated near a region in which the C/N ratio is maximized so as to effectively avoid deterioration of the C/N ratio of the reproduced signal, and thereby ensure that the digital video signal will be recorded and/or reproduced efficiently. In connection with the foregoing, it has been proposed to utilize a class IV partial response scheme in the reproduction and detection of a digital video signal, for example, as disclosed in U.S. Pat. No. 4,504,872, issued Mar. 12, 1985, and in U.S. Pat. No. 4,984,099, issued Jan. 8, 1991, and which has a common assignee herewith.
More specifically, since the C/N ratio in a magnetic recording and/or reproducing system is deteriorated at the low and high frequencies, its frequency characteristic can be approximated by a frequency characteristic H(ω) of a class IV partial response (1-D 2 ) scheme expressed by using a delay operator D as shown in FIG. 2.
Incidentally, the frequency ω 0 that is, the Nyquist frequency at which the response is minimized, has a relation to the delay time T imposed by the delay operator D as shown by the following equation: ##EQU1##
Accordingly, if the amount of delay imposed by the delay operator D is selected so that the signal spectrum is concentrated near the region in which the C/N ratio is maximized, then the digital video signal can be recorded and/or reproduced efficiently by effectively utilizing the frequency characteristic of the magnetic recording and/or reproducing system.
In other words, in the recording mode, a calculation process corresponding to the following expression (2) is sequentially performed on the digital video signal: ##EQU2## where MOD2 represents the remainder of 2.
Further, since the electromagnetic transducing system, for example, a magnetic head, has a differentiation characteristic, a reproduced signal from the magnetic head has a characteristic expressed as (1-D) with reference to the delay operator D and which is shown by the correspondingly labeled dashed line in FIG. 2.
Accordingly, in the playback or reproducing mode, a calculation process of (1+D) is performed on the reproduced signal, whereby the correction expressed by the following equation can be executed:
(1-D).(1+D)=1-D.sup.2 ( 3)
Owing to expression (2) and equation (3), the digital video signal can be reproduced with the transfer function of the recording and reproducing system being maintained at "1".
When the digital video signal is recorded and/or reproduced by making effective use of class IV partial response signalling, a digital video signal having a small bit error rate can be reproduced by the application of the Viterbi decoding technique, which indicates that, as shown in FIG. 2, the digital video signal can be efficiently detected by effectively utilizing a frequency characteristic nearly equal to the characteristic of FIG. 1 which represents the frequency characteristic of the magnetic recording and/or reproducing system.
For example, as disclosed in detail in "Analog Viterbi Decoding for High Speed Digital Satellite Channels", A. S. Acampora et al., IEEE Transactions on Communications, Vol. Com. 26, No. 10, October 1978, pages 1463-1470; and in "The Viterbi Algorithm", G. D. Forney, Jr., Proceedings of the IEEE, Vol. 61, No. 3, March 1973, pages 268-278, a Viterbi decoding circuit utilizes likelihood of correlation between data input successively thereto for detecting transit of the data and decodes the data on the basis of the detected result.
Accordingly, if the relationship (1-D 2 ) of the reproduced signal relative to the signal used for recording (hereinafter referred to as the "recording signal") is utilized to decode the recording signal from the reproduced signal and then the digital video signal is decoded on the basis of the decoded data, the bit error rate of the decoded data can be reduced as compared with a standard decoding circuit which decodes data with reference to the signal level.
A known reproducing circuit of a digital VTR which incorporates class IV partial response and Viterbi decoding schemes will now be described with reference to FIG. 3 in which digital video data recorded as a binary signal in analog form on a video tape 1 is reproduced by a magnetic head 2. The reproduced signal is supplied through an amplifier 3 to an equalizer circuit 4, and the equalized reproduced signal output from the equalizer circuit 4 is supplied to a processing circuit 5. The processing circuit 5 performs on this reproduced signal the calculation (1+D) in accordance with the above-mentioned partial response scheme. A calculated output of the processing circuit 5 is supplied to an analog-to-digital (A/D) converter 6. A reproduced clock is generated from the reproduced signal by a phase-locked loop (PLL) circuit 7 to which the output of the amplifier 3 is supplied. This reproduced clock is supplied to the A/D converter 6 which detects digital data from the reproduced signal level on the basis of the reproduced clock. Detected digital data is supplied to a Viterbi decoder circuit 8, in which the data is decoded in accordance with the Viterbi decoding scheme to detect a digital video signal. The thus detected digital video signal is supplied through an output terminal 9 to a reproduced signal processor circuit (not shown) at a next or succeeding stage.
When the digital video signal is reproduced by the known circuit arrangement of FIG. 3, the transmission rate of the digital video data is very high so that the frequency of a clock necessary for processing reproduced data in each of the circuits must be selected to be higher than 300 MHz. The circuits which are operated at such high clock frequency require a calculation circuit of a special configuration, which cannot be readily provided in actual practice. Further, it is preferable that the equalizer circuit 4 and the processing circuit 5 be fabricated as digital circuits because digital equalizer circuits and digital processing circuits can provide excellent characteristics. However, it is very difficult to operate the equalizer circuit 4 and the processing circuit 5 at any clock frequency higher than 30 MHz if these circuits 4 and 5 are in digital form. Therefore, in the circuit according to the prior art shown on FIG. 3, the equalizer and processing circuits 4 and 5 precede the analog-to-digital converter 6 and are not fabricated as digital circuits.
Similarly, in U.S. Pat. No. 4,504,872 referred to above, the analog-to-digital conversion follows passage of the reproduced signal through a 1-D 2 class IV response filter so that the latter is not fabricated as a digital circuit and, hence, does not realize the advantageous characteristics inherent in digital fabrication.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved apparatus for detecting digital data in which the above-mentioned problems and disadvantages encountered with the prior art can be substantially eliminated.
More specifically, it is an object of the present invention to provide an apparatus for detecting digital data in which, when digital data is detected in a digital video tape recorder or the like, a signal processing speed of each of the circuits can be substantially decreased.
It is another object of the present invention to provide an apparatus for detecting digital data in which the circuit arrangement thereof can be simplified so as to be operable by a clock signal of a relatively low frequency.
According to an aspect of the present invention, an apparatus for detecting input digital data is comprised of a distributor circuit for distributing the input digital data into at least two channels, a processing circuit in each of the channels for processing the digital data in the respective channel in accordance with a predetermined formula, a decoder circuit in each of the channels for decoding an output of the processing circuit in the respective channel in accordance with the Viterbi algorithm, and a composing circuit for composing or combining the outputs of the decoder circuits in the channels so as to obtain digital data in one sequence.
In accordance with another aspect of the present invention, an apparatus for reproducing digital data recorded as a binary signal in analog form on a magnetic tape is comprised of a playback circuit for reproducing the binary signal in analog form from the magnetic tape by means of a magnetic head, an A/D converter for converting an output of the playback circuit into digital data, a distributing circuit for distributing the digital data into at least two channels, a processing circuit in each of the channels for processing the digital data in the respective channel in accordance with a class IV partial response, a decoder in each of the channels for decoding an output of the processing circuit in the respective channel in accordance with the Viterbi algorithm, and a composing circuit for composing or combining the outputs of the decoders in the channels so as to obtain digital data in one sequence.
The above, and other objects, features and advantages of the present invention, will become apparent from the following detailed description of an illustrative embodiment thereof to be read in conjunction with the accompanying drawings, in which like reference numerals are used to identify the same or similar parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are frequency characteristic graphs to which reference is made in explaining a partial response scheme used in the prior art;
FIG. 3 is a schematic block diagram showing an example of a reproducing circuit of a digital video tape recorder according to the prior art which incorporates a class IV partial response scheme and a Viterbi decoding scheme;
FIG. 4 is a schematic block diagram showing an apparatus for detecting digital data according to an embodiment of the present invention;
FIG. 5. (Formed of FIGS. 5A and 5B) is a schematic block diagram showing a specific example of a main portion of the embodiment of the present invention shown in FIG. 4; and
FIGS. 6A through 6C and FIGS. 7A through 7E are timing charts to which reference is made in explaining operation of the embodiment of the present invention shown on FIGS. 4 and 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An apparatus for detecting digital data according to an embodiment of the present invention will hereinafter be described with reference to FIGS. 4 and 5, in which parts corresponding to those described with reference to FIG. 3 are identified by the same reference numerals and therefore will not be again described in detail.
In the illustrated embodiment, the invention is shown applied to a reproducing system of a digital video tape recorder in which digital data representing a video signal are recorded as a binary signal in analog form on a magnetic tape. This reproducing system is generally arranged as shown in FIG. 4, and in which the signal reproduced from the magnetic tape 1 by the magnetic head 2 is supplied through the playback amplifier 3 to the A/D converter 6, and digital data is derived from the reproduced signal by this A/D converter 6 on the basis of the reproduced clock signal supplied thereto from the PLL circuit 7.
Digital data output from the A/D converter 6 are divided into an odd sequence and an even sequence which are then supplied to respective channels containing equalizer circuits 11 and 12, respectively. In this embodiment, each of the equalizer circuits 11 and 12 is formed of a transversal filter. Outputs of the equalizer circuits 11 and 12 are supplied to processing circuits 21 and 22 in the respective channels which perform the (1+D) calculation on the outputs of the equalizer circuits 11 and 12, respectively, where D is a delay operator. In the embodiment being described, the processing circuit 21 derives the thus processed data for the odd sequence and the processing circuit 22 derives the thus processed data for the even sequence.
Outputs of the processing circuits 21 and 22 are supplied to Viterbi decoders 23 and 24, in the respective channels. The Viterbi decoder 23 is operable to Viterbi-decode data of the odd sequence and the Viterbi decoder 24 is operative Viterbi-decode data of the even sequence. Outputs of the two Viterbi decoders 23 and 24 are supplied to a change-over switch 25. The change-over or composing switch 25 alternately switches the outputs for the odd sequence and the even sequence from the Viterbi decoders 23 and 24 to compose them into data of one sequence, and supplies this data of one sequence to an output terminal 26. Data developed at the output terminal 26 are supplied to a reproduced signal processing circuit (not shown) forming a succeeding stage.
A specific circuit arrangement extending from the A/D converter 6 through the processing circuits 21 and 22 will now be described with reference to FIGS. 5A and 5B which together constitute FIG. 5.
In the arrangement of FIG. 5, the A/D converter 6 detects digital data from the level of a reproduced signal developed at a terminal 6a on the basis of a reproduced clock signal supplied thereto through a terminal 6b from the PLL circuit 7 (FIG. 4). The frequency of the reproduced clock signal supplied to the terminal 6b is selected to be 40 MHz.
The output digital data from the A/D converter 6 are supplied to a distributor which includes latch circuits 41 and 42. The latch circuits 41 and 42 latch the digital data on the basis of a clock signal having a frequency of 20 MHz and which is supplied thereto through a terminal 40. The clock signal supplied to the latch circuit 41 and the clock signal supplied to the latch circuit 42 are inverted in phase relative to each other by 180 degrees, so that the latch timings of the latch circuits 41 and 42 are displaced from each other, whereby data of an even sequence is latched by the latch circuit 41 and data of an odd sequence is latched by the latch circuit 42.
Data latched by the latch circuit 41 is supplied through a latch circuit 43 functioning as a delay circuit to the equalizer circuits 11 and 12, and data latched by the latch circuit 42 is supplied through latch circuits 44 and 45 arranged in series and also functioning as delay circuits to the equalizer circuits 11 and 12. The 20 MHz clock signal applied to the terminal 40 is also supplied to the latch circuits 43, 44 and 45, so that data are delayed by one clock in each of the latch circuits 43, 44 and 45.
In the equalizer circuit 11, output data from the latch circuit 43 is supplied to a series circuit of delay circuits 11a and 11b and output data from the latch circuit 45 is supplied to a delay circuit 11c. Outputs of the delay circuits 11a, 11b and 11c are supplied through coefficient multipliers 11d, 11e and 11f, respectively, to an adder 11g. In the equalizer circuit 12, output data from the latch circuit 43 is supplied to a series circuit of delay circuits 12a and 12b, and output data from the latch circuit 45 is supplied to a series circuit of delay circuits 12c and 12d. Outputs of the delay circuits 12b, 12c and 12d are supplied through coefficient multipliers 12e, 12f, 12g, respectively, to an adder 12h. The coefficient multipliers 11d, 11e and 11f and the coefficient multipliers 12e, 12f and 12g are operative to multiply the respective delayed data supplied thereto by coefficients K 1 , K 2 and K 3 , respectively.
Thus, the two equalizer circuits 11 and 12 constitute respective transversal filters and the adders 11g and 12h provide equalized signals, respectively. By adjusting coefficients k1, k2 and k3 employed in the coefficient multipliers 11d, 11e and 11f, and in the coefficient multipliers 12e, 12f and 12g of the equalizer circuits 11 and 12, the equalizing level is changed. Each of the delay circuits 11a, 11b, 11c, 12a, 12b, 12c and 12d is formed of a latch circuit which delays an input signal by a delay time of one clock having the frequency of 20 MHz.
Outputs of the equalizer circuits 11 and 12 are supplied to the processing circuit 21 which performs the (1+D) calculation so as to obtain the processed data of the odd sequence. More specifically, the output data of the equalizer circuit 11 is supplied through a series circuit of delay circuits 21a and 21b to one input terminal of an adder 21c, and the output of the equalizer 12 is supplied through a delay circuit 22a to the other input terminal of the adder 21c. An added or sum output of the adder 21c is supplied through a delay circuit 21d to an input terminal 23a of the Viterbi decoder circuit 23 in the respective channel. In other words, the output of the delay circuit 21d is supplied to the Viterbi decoder circuit 23 which Viterbi-decodes the data of the odd sequence constituting the output of the processing circuit 21.
The outputs of the equalizer circuits 11 and 12 are also supplied to the processing circuit 22 which perform the (1+D) calculation so as to obtain the processed data of the even sequence. More specifically, an output of the delay circuit 21a in the odd sequence data processing circuit 21 is supplied to one input terminal of an adder 22b, and an output of the delay circuit 22a is supplied to the other input terminal of the adder 22b. An added or sum output of the adder 22b is supplied through a delay circuit 22c to an input terminal 24a of the Viterbi decoder circuit 24. In other words, the output of the delay circuit 22c is supplied to the Viterbi decoder circuit 24 which Viterbi-decodes the data of the even sequence constituting the output of the processing circuit 22.
Incidentally, each of the delay circuits 21a, 21b and 21d, and each of the delay circuits 22a and 22c in the processing circuits 21 and 22 respectively, is formed of a latch circuit which delays the input signal input thereto by a delay time of one clock period of the clock signal having a frequency of 20 MHz.
Operation of the above embodiment of the invention will now be described with reference to FIGS. 6A through 6C and FIGS. 7A through 7E.
If it is assumed that digital data a 1 , a 2 , a 3 , . . . are output with a sampling frequency of 40 MHz from the A/D converter 6, as shown on FIG. 6A, then such digital data will be divided into data a 0 , a 2 , a 4 . . . , of even sequence (FIG. 6B) and data a -1 , a 1 , a 3 , . . . of odd sequence (FIG. 6C). The data shown in FIG. 6B represents the output of the latch circuit 43 and the data shown in FIG. 6C represents the output of the latch circuit 44. Since the digital data are divided into the data of the even sequence and the data of the odd sequence, as described above, the sampling frequency of the data of the even or odd sequence becomes 20 MHz which is one-half the sampling frequency of 40 MHz of the original data. Further, by delaying the data of the odd sequence by the latch circuit 44, the data of the even sequence and the data of the odd sequence are synchronized with each other.
The data of the even sequence and the data of the odd sequence divided from each other are then supplied to the transversal filter or equalizer circuits 11 and 12, respectively, thereby generating equalized data EQ which are separately equalized for the odd and even sequences. More specifically, assuming that data EQ 1 , EQ 3 , EQ 5 , . . . obtained at a junction or point e 1 corresponding to the output of the delay circuit 21a, are considered the output of the equalizer circuit 11, as shown in FIG. 7A, then data EQ 0 , EQ 2 , EQ 4 , . . . are obtained at a point e 2 , corresponding to the output of the delay circuit 22a at the same timing, and may be considered the output of the equalizer circuit 12, as shown in FIG. 7B. Further, at the same timing, as shown in FIG. 7C, data EQ -1 , EQ 1 , EQ 3 , . . . will be obtained at a point e 3 corresponding to the output of the delay circuit 21b.
The added or sum output of the adder 21c in the processing circuit 21 is simply the sum of the signals at the points e 2 and e 3 , and hence becomes the data EQ -1 +EQ 0 , EQ 1 +EQ 2 , EQ 3 +EQ 4 , . . . as shown in FIG. 7D. This added output is supplied to the Viterbi decoder circuit 23 which decodes the data of the odd sequence as the data processed by (1+D).
Similarly, the added or sum output of the adder 22b in the processing circuit 22 is simply the sum of the signals at the points e 1 and e 2 , and hence becomes the data EQ 1 +EQ 0 , EQ 3 +EQ 2 , EQ 5 +EQ 4 , . . . as shown in FIG. 7E. This added output is supplied to the Viterbi decoder circuit 24 which decodes the data of the even sequence as the data processed by (1+D).
The data of the odd sequence and the data of the even sequence are separately decoded by the two Viterbi decoder circuits 23 and 24 and then composed into data of one sequence by operation of the switch 25.
It will be seen that, in the data detecting circuit according to this embodiment of the invention, the reproduced signal is converted into digital data by the A/D converter 6 before being equalized so that the transversal filter or equalizing circuits 11 and 12 and the processing circuits 21 and 22, each of which performs the calculation of (1+D), can be fabricated as digital circuits. Accordingly, the digital equalizing circuits 11 and 12 and the digital processing circuits 21 and 22 can be provided with stable characteristics which can be adjusted with ease. Further, since the equalizer circuits 11 and 12 and the processing circuits 21 and 22 are arranged in respective channels to divide the data into data of an odd sequence and data of an even sequence, the digital signal having a sampling frequency of 40 MHz is equalized using a clock frequency which is one-half the sampling frequency, that is, a clock frequency of 20 MHz, and the (1+D) calculation or processing is also performed with such reduced frequency. Therefore, a simplified digital data detecting circuit which is operable by a clock of relatively low frequency can be employed, that is, there is no need to provide a special circuit which is operated by a clock signal of high frequency.
While the reproduced data is divided into data of 2 channels, that is, data of an odd sequence and data of an even sequence, in the above described embodiment of the invention, it will be appreciated that the reproduced data may be divided into data of 3 or more channels to thereby further lower the clock frequency.
Although, the present invention is described above as being applied to the reproducing circuit of a digital VTR, the present invention is not limited thereto and may be applied to a variety of digital devices.
Since the above described digital data detecting apparatus employing the partial response scheme and the Viterbi decoding system can be incorporated in a simple circuit operated by a clock signal of relative low frequency, it will be apparent that the digital data detecting apparatus embodying the present invention can be applied to a consumer digital VTR which, of necessity, is limited in cost.
Having specifically described a preferred embodiment of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to that precise embodiment, and that various changes and modifications could be effected therein by one skilled in the art without departing from the spirit or scope of the invention as defined in the appended claims.
|
In an apparatus for detecting input digital data, for example, as derived by analog-to-digital conversion of a reproduced binary signal in analog form; a distributor circuit distributes the input digital data into at least two channels, a processing circuit in each channel processes the respective digital data in accordance with a predetermined formula, a decoder in each channel decodes an output of the respective processing circuit in accordance with the Viterbi algorithm, and the outputs of the decoders are composed or combined to provide therefrom a single sequence of digital data.
| 6
|
This invention was made with Government support and the Government has certain rights in the invention.
BACKGROUND
When a digital to analog converter (DAC) converts the input digital bits into an analog output, each bit is assigned a weight. The sum of all weighted bits is then the analog output. However, the weights typically are not exactly the desired values. For example, although weights of 4, 2 and 1 are desired, they may actually be 3.4, 2.25 and 1.25. The result is that the analog output may not always increase as the digital input increases.
The problem is most pronounced at “major carry” transitions in the input code, as exemplified by the midscale transition between input code [0,1,1, . . . , 1,1] and [1,0,0, . . . , 0,0]. As the number of bits increase, the tolerances on individual bit weights decreases. More stringent tolerances on bit weights increase the cost of DACs and can limit the number of bits a DAC can accept. A corollary consequence is precision control based on non-monotonic DACs is difficult to ensure.
Previously known approaches to building precision DACs with more than 12 bits required very precise component matching and/or calibration to maintain monotonicity. More than 12 bits would require expensive or even unrealistic component tolerances. An alternative solution offering a guaranteed monotonic DAC used a thermometer code for the most significant bits and dithered the least significant bits. While this design may guarantee monotonicity, it may not allow the precise analog control desired in some applications.
A DAC is needed with a monotonic output at all transitions. Such a DAC should be extendable to a large number of bits without requiring components with unusually stringent tolerances.
SUMMARY
The problem of non-monotonic N+1 bit digital to analog converters (DACs) is solved by using an N bit differential DAC with true and complement outputs, where the outputs are offset by a half Least Significant Bit (LSB) and creating the N+1 bit output from appropriately weighted sums of the N bit DAC's outputs, where the transition at the major bit transition involves only the half LSB offset.
In a first embodiment N+M bit Digital to Analog converter (DAC) comprising: an N bit digital to analog converter (DAC) with a true output and a complementary output; wherein the true output and complementary output of the N bit digital to analog converter are offset by substantially a half LSB; a first weighting processor producing a true output of the N+M bit digital to analog converter, wherein the true output is a weighted combination of the true and complementary outputs of the N bit digital to analog converter; a second weighting processor producing a complementary output of the N+M bit digital to analog converter, wherein the complementary output is a weighted combination of the true and complementary outputs of the N bit digital to analog converter; wherein the first and second weighting processors adjust at each major carry transition of M most significant input bits such that the true output and complementary output are monotonic.
In another embodiment, a N+1 bit Digital to Analog Converter (DAC) comprising: an N bit DAC wherein the N bit DAC has a true output and a complementary output and wherein the outputs are offset by substantially a half LSB; an input processor accepting N+1 input bits and supplying N input bits to the N bit DAC such that the input processor maintains the input to the N bit DAC across a major carry transition of the N+1 input bit; a first processing unit producing a true output of the N+1 bit DAC, wherein the output is a weighted combination of the complementary output of the N bit DAC and the true output of the N bit DAC; wherein the weighting is such that the true output of the N+1 bit DAC is monotonic across the change of the N+1 input bit; a second processing unit producing a complementary output of the N+1 bit DAC, wherein the output is a weighted combination of the complementary output of the N bit DAC and the true output of the N bit DAC; wherein the weighting is such that the complementary output of the N+1 bit DAC is monotonic across the change of the N+1 input bit.
In another embodiment, a N+2 bit digital to analog converter (DAC) comprising: N+2 input bits, a true analog output and a complementary analog output; an N bit digital to analog converter (DAC) wherein the N bit converter has N input bits, a true output and a complementary output and wherein the outputs are offset by substantially a half LSB; a first switch wherein the complementary output of the N bit converter is switched to either a first output, a second output or a third output of said first switch according to the state of the N+2 and N+1 input bits; a second switch wherein the true output of the N bit converter is switched to either a first output or a second output of said second switch according to the state of the N+2 and N+1 input bits; an exclusive OR gate accepting the N+1 input bits and supplying the N input bits of the N bit DAC wherein each of the N input bits is exclusively OR'd with the N+1 bit; a first processing unit with an output and first, second, third and fourth inputs wherein the output is the complementary output of the N+2 bit DAC, the first input is connected to the first output of the first switch, the second input is connected to the first output of the second switch, the third input is connected to the second output of the first switch and the fourth input is connected to the second output of the second switch; a second processing unit with an output and first, second, third and fourth inputs; wherein the output is the true output of the N+2 bit DAC, the first input is connected to the first output of the second switch, the second input is connected to the second output of the first switch, the third input is connected to the second output of the second switch and the fourth input is connected to the third output of the first switch; wherein the first processing unit output is the sum of first input multiplied by a first scale factor, the second input; multiplied by a second scale factor, the third input multiplied by a third scale factor and the fourth input multiplied by a fourth scale factor wherein the second processing unit output is the sum of the first input multiplied by the fourth scale factor, the second input multiplied by the third scale factor, the third input multiplied by the second scale factor and the fourth input multiplied by the first scale factor.
Other embodiments use M N+1 bit DACs in cascade to comprise a N+M bit DAC. In another embodiment the N+M bit DAC may be built of a cascade of N+1 bit DACs and zero or more N+2 bit DACs.
DESCRIPTION OF THE DRAWINGS
The objects, features and advantages of the invention will be apparent from the following detailed description of the preferred embodiment of the invention in conjunction with reference to the following drawings where:
FIG. 1 shows the ideal output of a three bit digital to analog converter.
FIG. 2 illustrates the non-monotonicity when the error in the weighting of the most significant bit (for example) is large enough and of opposite sign of the errors in the lower significant bits.
FIG. 3 illustrates an N bit Exclusive OR gate used in the DAC of FIG. 4 .
FIG. 4 illustrates an embodiment of an N+1 bit DAC given an N bit DAC with half LSB offset in the output, a switch and two summers.
FIG. 5 is a table showing the output of the N+1 bit DAC of FIG. 4 when N is three.
FIG. 6 illustrates an embodiment of an N+2 bit DAC given an N bit DAC with half LSB offset in the output.
FIG. 7 is a table showing the output of the N+2 bit DAC of FIG. 6 when N is three.
FIG. 8 shows the switching and weighting functions of a generalized N+M bit DAC.
FIG. 9 shows cascaded N bit DACs connected to form an N+3 bit DAC.
DESCRIPTION
The following description is presented to enable one of ordinary skill in the art to make and use the invention and to incorporate it in the context of particular applications. Various modifications, as well as a variety of uses in different applications will be readily apparent to those skilled in the art, and general principles defined herein may be applied to a wide range of embodiments. Thus the invention is not intended to be limited to the embodiments presented, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
In the following detailed description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one skilled in the art that the invention may be practiced without necessarily being limited to specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the present invention.
All features disclosed in this specification, (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalents or similar features.
Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35USC Section 112, Paragraph 6. In particular, the use of step of or act of in the claims herein is not intended to invoke the provisions of 35USC Section 112 Paragraph 6.
The invention will be described with reference to the accompanying drawings. This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Further, the dimensions, materials and other elements shown in the accompanying drawings may be exaggerated to show details. The invention should not be construed as being limited to the dimensional or spatial relations or symmetry shown in the drawings, nor should the individual elements shown in the drawings be construed to be limited to the dimensions shown.
This invention describes a method and apparatus for converting a digital input to a monotonic analog output, despite large errors in the weighting of individual bits. When a digital to analog converter (DAC) converts the input digital bits into an analog output, each bit is assigned a weight. The sum of all weighted bits is then the analog output. For example, for a three bit digital value b2b1b0 the output is b2*w2+b1*w1+b0*w0. The weights w2, w1 and w0 should be 4, 2 and 1. The result is shown in FIG. 1 , a monotonic output. However, the weights typically are not exactly 4, 2 and 1. For example, they may actually be 3.4, 2.25 and 1.25. This is shown in FIG. 2 . When the input count goes from 011 to 100, that is at the major carry transition, the output will change from 3.5 to 3.4. The decrease in output when the input increases is non-monotonicity and is undesirable.
The problem is most pronounced at “major carry” transitions in the input code, as exemplified by the midscale transition between input code [0,1,1, . . . , 1,1] and [1,0,0, . . . , 0,0]. A major carry transition is not limited to N lower order bits and one higher order bit. Two most significant bits will have a major carry transition three times for the N lower order bits. This is illustrated in FIG. 7 and explained below. As an example and not as a limitation, DAC implementations with binary-weighted current sources or binary-weighted capacitor arrays should have the sum of the values of the N smaller terms equal to 1 LSB (Least Significant Bit) less than the value of the larger term (N+1st value) within a precision of less than 1 LSB to maintain monotonicity. As the number of bits increases, the tolerances on components to achieve individual bit weights decreases. This is one reason, but not the only reason, that precision control based on non-monotonic DACs is difficult to ensure.
The embodiment in FIG. 4 shows an example solution. The N+1 bit DAC 400 of FIG. 4 is built of an N bit DAC, an N bit Exclusive OR function, a switch and two weighting functions.
The N bit Exclusive OR 300 function shown in FIG. 3 ensures the output 340 will count up as the N bits of the input increase and then count down when the N bits reach a major carry transition. An alternative description of the N bit Exclusive OR function is that it maintains the input to the N bit DAC across the major carry transition. This is illustrated in FIG. 5 for N=3. The input 310 of the Exclusive OR 300 is shown in columns labeled d3d2 and d1. The output 340 of the Exclusive OR is in columns c3, c2 and c1. Note that c3c2c1 counts up as d3d2d1 counts up and then, when D4 changes from 0 to 1, c3c2c1 counts down. But across the major carry transition, the input d3d2d1 remains the same.
Returning to FIG. 4 , FIG. 4 shows an N+1 bit DAC 400 . The N+1 bit DAC 400 is built of an N bit DAC 418 , two weighting functions 438 and 440 , a switch 424 and an N bit Exclusive OR 414 . The N bit Exclusive OR 414 is shown in FIG. 3 and is described above. The weighting functions 438 and 440 may be implemented in a variety of technologies. Essentially, they scale their analog inputs 430 and 432 for weighting function 438 (and 434 and 436 for weighting function 440 ) by the weighting factor indicated for the particular analog input. The N bit DAC 418 can be implemented in a number of ways. The requirements on this DAC, which are easily implemented, are that it have differential outputs 420 and 422 , and that its output be offset by one-half LSB. By differential outputs it is meant that where the true output 422 ranges from half LSB to some positive value (2 N −½ LSB), the complementary output 420 equals the maximum value 2 N less the true output. As the N bit DAC input code 416 is incremented from [0, 0, . . . , 0] its true output 422 in units of its LSB will be 0.5, 1.5, 2.5, . . . rather than the normal 0, 1, 2, . . . . The complementary output is 7.5, 6.5, 5.5, . . . to 0.5 for N equals three. The switch 424 switches the complementary output 420 of DAC 418 from 426 to 428 when the N+1 bit 412 changes from zero to one, that is at a major carry transition. The true output 422 of the DAC 418 is connected to the half weight 432 and 436 inputs of weighting functions 438 and 440 respectively.
The true output 422 for a given input 416 is an analog value proportional to the decimal value of the binary input 416 . If the input 416 is [1001] then the true output is proportional to 9. The corresponding complementary output is proportional to 2 4 less the true output, not the negative or inverted value. If the input 416 is [1001] then the complementary output 422 is proportional to 16-9 or 7.
The weighted sums of the outputs 420 , 422 are combined as shown in 438 and 440 of FIG. 4 . For example: when the N+1 bit 412 is zero, the switch 424 is in the zero or 426 position; the complement output 482 of the N+1 bit DAC 400 is the sum of the complement output of the N-bit DAC 420 and ½ of its true output 422 ; while the true output 484 of the N+1 bit DAC 400 is ½ of the true output 422 of the N bit DAC 418 .
The operation of the N+1 bit DAC is shown in the table in FIG. 5 . Columns c3c2c1 are the outputs of the N bit Exclusive OR 414 , columns X and X are the outputs 422 and 420 , respectively, of the N bit DAC and columns Y and Y are the outputs 484 and 482 of the N+1 bit DAC. As the N+1 bit code D4d3d2d1 of the input 412 / 410 is incremented from [0, 0, . . . , 0] to [0, 1, . . . , 1], the N bit DAC 418 will count through its entire range, so that at [0, 1, . . . 1] its full scale true output 422 shown in column X of FIG. 5 is split evenly between the true output 484 in column Y and complement output 482 in column Y of the N+1 bit DAC 400 . Concurrent with N bit input 416 reaching all ones, the complement output 420 X of the N bit DAC 418 is at its minimum value of ½ LSB. At the major carry transition when D4 goes from 0 to 1 and the input D4d3d2d1 goes from [0, 1, . . . , 1] to [1, 0, . . . , 0]: the bank of exclusive-or gates 414 inverts all of the inputs 416 to the N bit DAC 418 as the most significant bit (MSB) 412 changes from 0 to 1, D4 in FIG. 5 ; the N bit code 416 , d3d2d1 in FIG. 5 , controlling the N bit DAC remains at [1, . . . , 1]; and the complement output 420 of the N bit DAC, X column in FIG. 5 , is switched by 424 from being summed into the complement output 482 to the true output 484 of the N+1 bit DAC 400 . Thus the only change in the output of the N+1 bit DAC 400 at the major carry is the transfer of ½ LSB of the N bit DAC 418 from the complement 482 to the true output 484 of the N+1 bit DAC 400 , corresponding to a 1 bit change in the output of the N+1 bit DAC 400 . As the N+1 bit input code is further incremented from [1, 0, . . . , 0] to [1, 1, . . . , 1], the inverted N bits 416 to the N bit DAC 418 count down from [1, . . . , 1] to [0, . . . , 0], so that the output 422 of the N bit DAC 418 is smoothly transferred to the true output 484 of the N+1 bit DAC 400 . Thus, over the full range of the N+1 bit word 412 / 410 from [0, 0, . . . , 0] to [1, 1, . . . , 1], the true output 484 of the N+1 bit DAC 400 ranges over 2 N+1 steps from ¼ LSB of the N bit DAC 418 to {(2 N −1)+¼ LSB} of the N bit DAC 418 in steps of ½ LSB of the N bit DAC 418 . The result is an N+1 bit DAC 400 with its outputs 482 , 484 offset by ½ LSB of the N+1 bit DAC.
As can be seen in FIG. 5 , at the major carry transition the input c3c2c1 to the N bit DAC continues as the mirror image of the previous values. The true output X 422 and complementary outputs X 420 do not change but the true output Y 484 of the N+1 bit DAC increments by virtue of the switching 424 from 426 to 428 of the complementary output X 420 in FIG. 4 .
This technique may be expanded to increase the resolution of the initial DAC by more than one bit, as illustrated by the embodiment in FIG. 6 where the resolution of the initial DAC 618 is increased by two bits. FIG. 6 shows an N+2 bit DAC 600 built from an N bit DAC 618 . The most significant bits 612 and 613 define three major carry transitions. As the N+2 bit input ( 613 , 612 , 610 ) varies from [0, 0, 0, . . . , 0] to [0, 0, 1, . . . , 1], the N bit DAC 618 counts up through its range while both switches S1 624 and S2 626 are in their left-most positions 631 and 641 respectively. Over this range, the complementary output 682 of the N+2 bit DAC 600 decreases from its maximum value to about 0.75 of maximum value while true output 684 increases from minimum to about 0.25 of full scale. At the major carry transition where the N+2 ( 613 , 612 , 610 ) bit code transitions from [0, 0, 1, . . . , 1] to [0, 1, 0, . . . , 0] the switch S1 624 is moved to its middle position 632 , and the Exclusive Or gate 614 inverts the input 616 to the N bit DAC 618 so that it remains at [1, . . . , 1]. As S1 624 is switched, the ½ LSB offset of the N bit DAC 618 is transferred from the complementary output 682 to being split evenly by the weighting functions 650 and 660 between the true output 684 and the complementary output 682 , thus ensuring a well controlled transition in the N+2 bit DAC output 684 at this carry. Over the N+2 bit code range from [0, 1, 0, . . . , 0] to [0, 1, 1, . . . , 1] the N bit DAC 618 counts down (because its inputs 616 are inverted when the N+1 st bit 612 is “1”); the complementary output 682 of the N+2 bit DAC 600 covers the range from 0.75 to 0.5 of full scale while the true output 684 ranges from 0.25 to 0.5 of full scale. At the transition from [0, 1, 1, . . . , 1] to [1, 0, 0, . . . , 0] in the N+2 bit input, the input 616 to the N bit DAC is no longer inverted, so it remains at [0, . . . , 0], and S2 626 is switched to the right, transferring the ½ LSB offset of the N bit DAC 618 from a weight of 0.75 to 0.25 in the sum forming the complementary output 682 and from a weight of 0.25 to 0.75 in the sum forming true output 684 , providing a smooth transition across this carry. Similarly, the N bit DAC 618 counts up over the range from 0.5 to 0.25 of full scale in the complementary output 620 and 0.5 to 0.75 in true output 622 and counts down over the range 0.25 to 0 in complementary output 620 X and 0.75 to 1 in true output X 622 . At each of the major carries the output of the N bit DAC 618 that is carrying its full scale output remains connected as it was, and the output that is carrying only the ½ LSB offset is the one that is switched to change the output of the N+2 bit DAC by 1 LSB, maintaining the monotonicity.
The switches 624 and 626 alternate at each major carry transition. For each position 631 to 633 and 641 to 642 in FIG. 6 there is the associated bit pattern for the switch 624 and 626 positions. One can see that as the N+2, N+1 bits count from 00 to 01 only switch 624 will switch from the 631 position to the 632 position and when the count changes from 01 to 10 switch 624 holds while switch 626 moves from 641 to 642 .
FIG. 7 shows a table of the outputs of the N+2 bit DAC 600 as a function of the inputs for N=3. As can be seen, the bits 616 driving the N Bit DAC 618 count up then count down under the control of D5 and D4. IF D5D4 is even, then the N Bit DAC 618 input c3c2c1 counts up. If D5D4 is odd, then the N Bit DAC 618 counts down. At each carry transition in D5D4 the switches 624 and 626 alternately “rotate” to the right as the count D5D4 increases. The references 631 , 632 , 633 , 641 and 642 of FIG. 6 show the switch positions for the D5D4 values indicated. The reference to the switch “rotating” is not intended to be limited to physical movement in the mechanical sense but is a conceptual description to explain the function. A person skilled in the art would be able to construct a switch that accomplishes the function described with no moving parts.
The extension of this technique to provide M bits of increased resolution is straightforward. Extending this technique to add M bits to a monotonic N bit DAC requires weighting functions with 2M inputs and switches with 2M outputs. The N bit DAC can be made to alternately count up and down across the operating range so that the complementary and true signal from the N bit DAC is switched at the carry points defined by the M extra bits. At each carry point either the true output or the complementary output that is switched has the value of only the ½ LSB offset. FIG. 8 shows a generalized N+M bit DAC with monotonic outputs. The N bit DAC and N bit Exclusive OR functions have been omitted from the figure since they are connected and operate as described for FIGS. 4 and 6 . The N+M Bit DAC is built from two weighting functions 810 A and B with weights as indicated for each input. That is, the 2 M −3 input has a weight of 2 M −3 applied to the input. This is not a contradiction with FIG. 6 since the generalized weighting function 810 does not use the scaling functions 655 and 665 of FIG. 6 , or rather the scaling functions are combined into the weights. If scaling functions 655 and 665 were present in FIG. 8 their value would be 2 M and each weight on the input would be divided by 2 M . Note the weighting function 810 is used twice (A and B) and it has an input with a weight of zero. The zero weight input was not drawn in FIG. 6 but shown in FIG. 8 to highlight the symmetry in the embodiment. The switch 830 switches the complementary input 820 to the specified input of the weighting function 810 A when the controlling bits d(N+M):d(N+1) represent the values 824 shown for switch 830 . Likewise, switch 835 switches the true input 822 to the indicated input of the weighting function 810 B when the controlling bits d(N+M):d(N+1) represent the values 827 shown for switch 835 . Switches 830 and 835 are not identical. Switch 830 has 2 M−1 +1 switch positions and switch 835 has 2 M−1 switch positions. In operation, each time the switch 830 or 835 changes, a ½ LSB is switched from one weighting function 810 to the other.
When an N Bit DAC 418 (or 618 ) and N Bit wide Exclusive OR 300 (or 614 ) is added to FIG. 8 , one obtains an N+M bit DAC.
In another embodiment, the approach above can be used to obtain an extended resolution monotonic DAC by cascading stages of the N Bit DAC 400 described above. As shown in FIG. 4 , the DAC 418 is a differential DAC with its outputs offset by ½ LSB; the output is also in the same format, so that it may serve as the input to a subsequent stage in which the resolution is extended further. As shown in FIG. 9 , such an extension may be implemented in a pipelined manner, with separate hardware at each stage. Alternatively, given discrete time circuitry, an extension may be implemented in a recursive fashion, where the output of a stage is held and used as the input to the same hardware for further extension of the resolution.
FIG. 9 shows a three bit extension to the N bit DAC 418 of FIG. 4 . Each N bit exclusive OR 300 is as shown in FIG. 3 where the N+1 bit gates each of the N lower order bits. The weighting functions and switch 424 , 438 and 440 are the same as in FIG. 4 but repeated three times. The N+3 bit DAC may itself be used as a building block for increased resolution DACs.
A single stage of the sort described above in FIG. 4 or 6 is very tolerant of errors that could result from mismatches, gain errors, offsets and the like. Pipelined or recursive implementations, such as in FIG. 9 , are similarly robust with the exception of offsets introduced in producing the weighted sums. The process of increasing the resolution depends on having an offset of nominally ½ LSB in the lower resolution DAC that is to have its resolution extended. If the offset is not exactly ½ LSB the step size at the carry points will differ from an LSB as seen at the extended range output. In order to maintain monotonicity, that offset has to be within the range between 0 and 1 LSB. Since the LSB decreases through the length of a pipeline, or through the sequence of steps in a recursive implementation, eventually a point will be reached where even a very small offset in the summing circuitry will produce a nonmonotonic output. The number of stages that may be used in a pipeline or recursive implementation is set by the requirement that the offset, both intentional and accumulated from errors, at the input to the last stage is within the range of 0 to 1 LSB.
An advantage of the use of stages that increase resolution by more than one bit per stage is that the resolution obtainable while still maintaining monotonicity is increased if the last stage adds more bits. For a 16 bit DAC, the design estimates were that offsets could be controlled within allowable limits to the 11 or 12 bit level. A 16 bit DAC was chosen to have an initial 1 bit DAC, and a stage that adds 5 bits that is used recursively three times to reach 16 bits of resolution. The input to the last stage is thus at a resolution of 11 bits.
|
Apparatus implementing a monotonic output digital to analog converter (DAC). A high resolution monotonic DAC may be built from a lower resolution DAC using weighting functions that combine the outputs of the lower resolution DAC such that monotonicity is maintained across major carry transitions. The lower resolution DAC should have a true output and a complementary output with a half LSB bias in the output. An extended resolution DAC may be built of; cascaded low resolution DACs; a low resolution DAC in a recursive arrangement with an intermediate storage of its output; or a low resolution DAC with weighting functions that adjust at each of several major carry transition.
| 7
|
FIELD OF THE INVENTION
The present invention relates to an improved photocoupler alone, or a device that uses a photocoupler, comprising light-emitting diodes and photodiodes, and in particular, a photocoupler having a structure for compensating for non-linearity related to current-voltage properties of light-emitting diodes.
DISCUSSION OF THE BACKGROUND ART
Photocouplers have been used for insulation and separation of signals among input signals and output signals. In recent years there has been a demand for photocouplers that are useful for high-speed analog signal transmission while improving the insulation and separation characteristic. The nonlinearity of photocouplers, particularly the nonlinearity associated with the voltage-current properties of LEDs, becomes a problem in this case. That is, if the photocoupler has a strong nonlinearity, this will result in the distortion of signals during analog signal transmission.
A method of applying negative feedback has been proposed as an example of technology for avoiding this problem (See JP (Kohyo) 11[1999]-509367 and JP (Kokai) 61[1986]-36981). By means of this method, an additional photodiode is positioned close to the light-emitting diode. This photodiode has a structure with which the amount of light emitted from the light-emitting diode is monitored and this is fed back to the operating current of the light-emitting diode.
Nevertheless, in addition to the difficulty of accurate monitoring, it is extremely difficult to design a high-speed circuit with this structure because the amplifier for amplifying the signals requires a band that is at least 10 times the transmission signal bandwidth and nonlinear elements are used. Consequently, this structure cannot be used for high-speed communications.
A method has also been suggested whereby analog signals are not transmitted and instead, analog signals are converted to digital signals and then transmitted, after which they are converted back to analog signals. However, AD/DA converters or additional circuits for modulation-demodulation are necessary in this case, complicating the circuit structure, and high speed operation is still difficult.
Therefore, the present invention seeks to improve the nonlinearity related to current-voltage properties of light-emitting diodes in photocouplers and provide a photocoupler with which relatively high-speed analog signal transmission is possible.
SUMMARY OF THE INVENTION
The present invention provides a photocoupler comprising two light-emitting diodes with almost common I-V properties, one of which is the principal light-emitting element and the other of which is a light-emitting element for compensation, in order to improve the nonlinearity of photocouplers, particularly the non-linearity associated with the properties of the light-emitting diodes. Compensation signals given to the light-emitting diode for compensation are determined from the operating input signals given to the principal light-emitting diode. These compensation signals are given as input of the light-emitting element for compensation. The light emitted from both of the light-emitting elements converges optically and is detected by a single photoelectric conversion detector (photodiode), or is detected by individual detectors, and this output is electrically combined. Transmission output signals with little distortion are obtained by superimposing these optical or electric signals.
A negative feedback means for the circuit is not necessary, and analog/digital conversion is not necessary, with the photocoupler of the present invention. Consequently, high-speed operation is possible with the photocoupler of the present invention. For instance, analog signals can be transmitted with little signal distortion at approximately 30 MHz or faster.
That is, the present invention provides a photocoupler which comprises first and second light-emitting diodes; a compensation circuit that compensates the input signals to this first light-emitting diode and produces input signals to this second light-emitting diode and makes the current waveform at this second light-emitting diode complementary to the current waveform at this first light-emitting diode; and at least one photodiode that detects the light emission of said first and second light-emitting diodes.
It is preferred that the compensation circuit determines that the input voltage waveform given to this second light-emitting diode becomes similar in shape but with a smaller output amplitude than the input voltage waveform to this first light-emitting diode.
It is preferred that the compensation circuit operates in such a way that the alternating-current component of this input voltage waveform is amplified by a pre-determined gain.
It is preferred that these first and second light-emitting diodes are grounded on one side.
It is preferred that this photodiode comprises separate first and second photodiodes corresponding to the first and second light-emitting diodes for receiving the light emitted from the respective light-emitting diode.
It is preferred that the photocoupler is structured such that signals that become the simple sum of detection signals are output by these first and second photodiodes.
It is preferred that a first group consisting of this first light-emitting diode and this first photodiode and a second group consisting of this second light-emitting diode and this second photodiode comprise separate integrated circuit (IC) packaged photocouplers.
It is preferred that these photodiodes become a single element that simultaneously receives the combined light emitted from these first and second light-emitting diodes.
It is preferred that this compensation circuit together with these light-emitting diodes and these photodiodes is included in a single IC package.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an electrical circuit that depicts the photocoupler according to the present invention.
FIG. 2 is a theoretical graph depicting the signal waveforms according to the present invention.
FIG. 3 is the compensation circuit according to the present invention.
FIG. 4 is an electrical circuit that depicts the photocoupler according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention provides a photocoupler with improved nonlinearity related to the current-voltage properties of light-emitting diodes in a photocoupler and with which relatively high-speed signal transmission is possible.
Photocouplers according to the present invention will be described in detail while referring to the attached drawings. FIG. 1 is a diagram describing a first embodiment of the present invention.
As shown in FIG. 1 , photocoupler 10 of the first embodiment comprises an input terminal 20 , a first light-emitting diode (principal light-emitting element) 30 , a second light-emitting diode (light-emitting element for compensation) 40 , a compensation circuit 50 that gives compensation input signals to second light-emitting diode 40 , a first photodiode 60 corresponding to first light-emitting diode 30 , a second photodiode 70 corresponding to second light-emitting diode 40 , and an output terminal 80 .
Each element constituting photocoupler 10 is made by mounting several packaged ICs on a circuit board. First light-emitting diode 30 and first photodiode 60 as well as second light-emitting diode 40 and second photodiode 70 must be structured such that they individually transmit and receive light signals and therefore, these groups are usually made into individual photocoupler ICs (refer to reference numbers 91 and 92 ). In this case, the compensation circuit is outside these ICs, but it can also be contained in one of these ICs. Furthermore, photocoupler 10 is an element providing electrical insulation and separation, and the side of light-emitting diodes 30 and 40 as well as the side of photodiodes diodes 60 and 70 , where light emitted from light-emitting diodes 30 and 40 is received, are separate boards.
Furthermore, although each group comprised of first light-emitting diode 30 and first photodiode 60 and comprised of second light-emitting diode 40 and second photodiode 70 can be contained in exactly the same package, independent signal transmission is necessary, and therefore, a barrier structure for optical separation is needed between the two groups, making production difficult. In this case, the compensation circuit can also be on a third board in the same package.
Input terminal 20 is a terminal that receives the high-frequency signals used for communications. The light signals received by input terminal 20 are guided through resistor R c1 to first light-emitting diode 30 . Pre-determined light emission is produced at first light-emitting diode 30 by the current that is flowing in accordance with the signal voltage waveform of the input signals. The current-voltage properties at first light-emitting diode 30 are usually nonlinear and therefore, light emission intensity to signal intensity is nonlinear and the output of the photodiodes that directly receive this light produce a signal distortion. The photocoupler 10 advantageously includes some elements for preventing this signal distortion, e.g. second light emitting diode 40 . Their effect is described below.
The input signals to second light-emitting diode 40 for signal compensation are given by compensation circuit 50 . Voltage signals for compensation are produced by reference to the waveform of signals input to first light-emitting diode 30 (point P). That is, second light-emitting diode 40 receives the signals generated by the compensation circuit for signal waveform compensation and emits light in accordance with these signals.
By means of the present embodiment, compensation circuit 50 multiplies the voltage waveform at point P in FIG. 1 k times to form signals of a similar voltage waveform and these serve as the compensation signals. The compensation signals are given to second light-emitting diode 40 through resistance R c2 .
Each signal waveform is shown in FIG. 2 . The broken line (W V1 ) in the figure is the voltage waveform at point P in FIG. 1 . The voltage waveform of the signal has already been distorted at the step before its input to first light-emitting diode 30 and its amplitude is relatively small on the positive side, while its amplitude is larger on the negative side when compared to the distortion-free sine waveform (dashed line: W R ). This voltage waveform is distorted due to the fact that point P is at the input position of the positive terminal of the light-emitting diode that has been grounded at the negative terminal side.
On the other hand, the waveform of the current that flows through first light-emitting diode 30 at this time is shown by the solid line (W I1 ). The light emission intensity at a light-emitting diode is generally considered to be almost proportional to the current within a normal range and therefore, this current waveform is apparently almost the same as the detected values at first photodiode 60 . As is clear from this figure, the current waveform, that is, the waveform of the detection signals at first photodiode 60 , has a relatively large amplitude on the positive side and a relatively small amplitude on the negative side.
As was previously explained, compensation circuit 50 gives the signal waveform for compensation of a shape similar to the voltage signal waveform at point P. When compensation signals are input to second light-emitting diode 40 , the waveform of the input voltage signals to second light-emitting diode 40 further deforms just as the distortion that is produced in the voltage waveform at point P and the signal amplitude of the compensation signal waveform becomes even smaller on the positive side when compared to the negative side, as shown by the dashed line (W V2 ). The waveform of the current that flows to second light-emitting diode 40 at this time (W I2 ) becomes smaller in amplitude on the positive side and larger in amplitude on the negative side, as shown by the solid line. As with first light-emitting diode 30 , this current waveform is approximately the same as the output waveform of second photodiode 70 .
What should be noted is that alternating current signals that are virtually distortion free (W out ) can be reproduced from the sum of the waveform of first light-emitting diode 30 and the current waveform of second light-emitting diode 40 , that is, the sum of the output waveform of first photodiode 60 and the output waveform of second photodiode 70 , but optimizing the value of above-mentioned “k.” That is, the distortion of signals can be compensated by using first and second light-emitting diodes 30 and 40 and the corresponding first and second photodiodes 60 and 70 .
If phase distortion of the current waveform signals is large, distortion compensation may not be sufficient when compensated by the sum of the current waveforms of first light-emitting diode 30 and second light-emitting diode 40 . A structure may be used here for combining the phase of two signals when the sum of current waveforms is used in order to efficiently reduce the distortion. An example of a specific means is the method whereby a buffer with the same delay as compensation circuit 50 is introduced behind photodiode 60 in order to improve the symmetry of the circuit structure. Furthermore, results that are satisfactory for practical application can be obtained by speeding up compensation circuit 50 .
FIG. 3 is a circuit diagram showing an example of the compensation circuit. The compensation circuit is shown together with the photocoupler that is used with the circuit. Compensation circuit 50 includes differential amplifier 51 . The voltage signals that branch at the input side of first light-emitting diode 30 are input to the positive terminal of differential amplifier 51 through capacitor C 1 . As shown in the figure, this positive terminal is grounded via resistor R 1 (10 kΩ) and the negative terminal is grounded via resistor R 2 with a smaller resistance (2.15 kΩ). Furthermore, although the negative terminal is connected to the output side via variable resistance R V , the resistor can also have a resistance that has been set at an optimal value.
As shown in the figure, the output of compensation circuit 50 is connected to a bias terminal via capacitor C 2 and is input to the LED terminal of photocoupler 92 . As a result, alternating-current signals that have been amplified to a pre-determined intensity by the compensation circuit are input to the photocoupler.
The output waveforms of first photodiode 60 and second photodiode 70 are electrically combined and output as sum signals in the embodiment in FIG. 1 . As a result, alternating-current signals that have been input to input terminal 20 are transmitted up to output terminal 80 as they are being brought to minimal distortion by being electrically insulated. Furthermore, signal treatment, such as the necessary amplification and so forth, is performed on the detection signals of first and second photodiodes 60 and 70 , or the sum signal of these detection signals, but a conventional amplification method can be used, and therefore, a description for this is not given.
FIG. 4 is a diagram showing a photocoupler that is a second preferred embodiment of the present invention. This photocoupler 110 comprises input terminal 120 , first and second light-emitting diodes 130 and 140 , compensation circuit 150 , photodiode 160 , and output terminal 180 . Photocoupler 110 is usually made into an individually packaged IC 190 as in the first embodiment, but it can also be made into an IC package that contains compensation circuit 150 .
The difference from the first embodiment is that a single photodiode 160 receives light from first and second light-emitting diodes 130 and 140 . That is, as with the first embodiment, input signals are given from input terminal 120 to first light-emitting diode 130 , and signals that are obtained when the signal voltage at the input side of the first light-emitting diode 130 is compensated by compensating circuit 150 are given to second light-emitting diode 140 . The light that has been emitted by light-emitting diodes 130 and 140 in accordance with these signals is received by a single photodiode 160 .
Consequently, in contrast to the fact that by means of the first embodiment, signals from first and second photodiodes 60 and 70 are electrically synthesized and output as a sum signal, by means of the second embodiment, they are synthesized as the sum of the amount of light (the sum of the number of photons) when light is received at photocoupler 160 and electric signals corresponding to this sum are output at photodiode 160 . That is, taking FIG. 2 into consideration once again, the signal waveform at the input side of first light-emitting diode 130 , that is, at point P, and the signal waveform at the input side of second photodiode 140 are optically synthesized. In other words, the sum waveform shown to the right in the figure is the same as the amount of light received by the single photodiode 160 and is understood to be the output from this photodiode 160 .
An advantage of the second embodiment is that the number of elements that are used can be minimized and as a result, the device can have a simpler structure. In particular, in addition to there being only one photodiode, additional circuits for amplification and synthesis of electrical signals in later steps are not necessary and therefore, there is a practical advantage in this case.
Preferred embodiments of the present invention were described above, but these are only examples and a variety of alterations and modifications by persons skilled in the art are possible. For instance, the number of light-emitting diodes in the present embodiments was two, but it is possible to add more light-emitting diodes. In this case, it is also possible to add photodiodes in combination with these light-emitting diodes, or it is possible for one photodiode to receive the light of three or more light-emitting diodes.
|
A photocoupler having a first and second light-emitting diodes, a compensation circuit, which compensates input signals to the first light-emitting diode and generates input signals to the second light-emitting diode, and further makes the current waveform at the second light-emitting diode complementary to the current waveform at the first light-emitting diode, and at least one photodiode that detects the light emitted from the first and second light-emitting diodes.
| 7
|
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to French Patent Application No. 01 09 009 filed Jul. 6, 2001.
The present invention relates to a process for the batchwise preparation of (meth)acrylic anhydride.
Acrylic and methacrylic anhydrides are reagents of choice in the the synthesis of (meth)acrylic thioesters, (meth)acrylic amides and (meth)acrylic esters, in particular of tertiary alcohols that cannot be obtained by standard esterification/transesterification processes.
They are also used in polymerization reactions or as crosslinking agents.
It has been known for a long time that it is possible to prepare an anhydride by reacting acetic anhydride with the acid corresponding to the desired anhydride.
As early as 1934, French patent No. 784 458 described the preparation of propanoic, butyric and caproic anhydride by reacting acetic anhydride with propanoic acid, butyric acid and caproic acid, respectively.
In 1979, European patent application No. 4 641 provided the public with a continuous or batchwise process for preparing carboxylic acid anhydrides such as benzoic, hexahydrobenzoic and trimethylacetic anhydride, by reacting, in reaction/distillation apparatus, the corresponding acids with acetic anhydride, preferably in stoichiometric proportions.
In 1986, German patent application No. 3 510 035 disclosed a process for continuously preparing carboxylic acid anhydrides such as acrylic or methacrylic anhydride by reacting, in a distillation column and in the presence of a catalyst such as sulphuric acid or sulphonic or phosphoric acids, acetic anhydride with the acid corresponding to the desired anhydride.
In 1987, French patent application No. 2 592 040 proposed a process for the batchwise synthesis of (meth)acrylic anhydride by reacting acetic anhydride with (meth)acrylic acid in the presence of polymerization inhibitors. According to this process, acetic anhydride and (meth)acrylic acid are first reacted together, the acetic acid formed during the reaction is withdrawn and a distillation is then carried out. The molar ratio between the (meth)acrylic acid and the acetic acid is chosen between 0.5 and 5 and preferably between 2 and 2.2.
However, the implementation of this process comes up against polymerization problems. In addition, the amount of anhydride produced is limited by the size of the reactor and thus by the amount of reagents loaded into this reactor.
The aim of the present invention is thus to propose a process for preparing (meth)acrylic anhydride which offers higher production efficiency and a reduction or even elimination of the risks of polymerization.
One subject of the invention is thus a process for the batchwise preparation of (meth)acrylic anhydride, in which acetic anhydride is reacted with (meth)acrylic acid and at least some of the acetic acid is removed gradually as it is formed.
This process is characterized in that the acetic acid removed is at least partly replaced by introducing into the reaction medium, during the reaction, acetic anhydride and/or (meth)acrylic acid.
Such a process allows a greater than 35% increase in production efficiency compared with the prior art processes.
Other characteristics and advantages of the invention will now be described in detail in the description that follows.
DETAILED DESCRIPTION OF THE INVENTION
The invention is based on the surprising discovery made by the Applicant, namely that, by means of an astute distribution of the reagents, it is possible to obtain large gains in production per batch (batchwise) of (meth)acrylic anhydride, without increasing the reaction time.
This very large increase in production per batch is obtained with an identical initial mass of reagents (acetic anhydride and (meth)acrylic acid).
This initial charge is preferably the maximum charge permitted by the volume of the reactor.
Thus, according to the invention, the acetic acid, which is formed by reaction of the acetic anhydride and which is at least partly removed gradually as it is formed, is replaced with one and/or the other of the reagents.
In other words, an amount of the reagent(s) is added to occupy the space liberated by the removal of the acetic acid.
Preferably, all the acetic acid that is formed during the reaction is removed, gradually and as it is formed, by distillation.
In order to optimize the production of (meth)acrylic anhydride, it is desirable to replace, by means of the reagent(s), all the acetic acid removed.
In addition, a continuous addition of the reagent(s) throughout the reaction time is a variant that is preferable to an irregular addition.
It is also preferable that this addition should follow, as closely as possible, the removal of the acetic acid.
This is then reflected by a virtually total occupation of the volume of the reactor throughout the reaction.
Preferably, only one of the reagents is added.
The reagent added is advantageously acetic anhydride.
Furthermore, the initial charge introduced into the reactor preferably has an initial molar ratio R 0 of the (meth)acrylic acid to the acetic anhydride of between 2.5 and 11 and in particular between 9 and 11.
The overall molar ratio R g of the (meth)acrylic acid to the acetic anhydride is preferably between 0.5 and 5 and in particular between 1.8 and 2.2.
The reaction may be carried out in a reactor on which is mounted a distillation column.
In general, the reactor is stirred and heated by circulating heat-exchange fluid in a jacket or by recirculation through an external heat exchanger.
The distillation column preferably has a separating efficiency of greater than 10 theoretical plates and in particular greater than 12 theoretical plates. This makes it possible to minimize the losses of acetic anhydride via the first distillation fraction, which in this case consists to more than 99% of acetic acid, to work at low levels of reflux (R/C less than or equal to 2/1) and consequently to reduce the reaction time and the risks of polymerization that increase as the reaction time increases.
The column packing may be a standard packing, in bulk form or structured, or a mixture of these two types of packing.
The reaction temperature is generally between 50 and 120° C. and preferentially between 85 and 105° C.
The pressure is adjusted as a function of the chosen reaction temperature. In general, it is between 20 and 200 mm Hg (0.0267 and 0.2666 bar).
The reaction may be carried out in “isobar” mode, i.e. by fixing the pressure and allowing the temperature to change up to a limit value preferably fixed between 90 and 150° C., or in “isothermal” mode, i.e. by fixing the temperature and adjusting the pressure in the plant throughout the reaction so as to maintain this pressure.
The temperature at the column head is advantageously adjusted during the reaction, as a function of the pressure, so as to correspond to the distillation temperature of acetic acid.
By working in this way, a head fraction containing more than 99% acetic acid is obtained.
According to one preferred embodiment of the invention, the reaction between acetic anhydride and (meth)acrylic acid is carried out in the presence of at least one polymerization inhibitor.
In addition, a double-stabilization is preferably carried out, by introducing at least one inhibitor into the reactor and at least one inhibitor into the distillation column.
The inhibitors must be active with respect to polymerization while at the same time being inert with regard to the anhydrides and the (meth)acrylic acid.
Thus, all risk of polymerization in the reactor and the column is avoided.
The inhibitor for the reactor is advantageously chosen from the group consisting of 2,4-dimethyl-6-tert-butylphenol (“Topanol A”) and 2,6-di-tert-butyl-para-cresol (“BHT”), and mixtures thereof.
The inhibitor for the distillation column is advantageously chosen from the group consisting of hydroquinone (“HQ”), 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-para-cresol and phenothiazine, and mixtures thereof.
As regards the amounts to be used, the reactor inhibitor is preferably introduced into the initial charge of reagents in a proportion of at least 0.001% (1000 ppm) by weight of the charge.
The distillation column inhibitor is preferably introduced into the distillation column throughout the reaction, for example as a 5% solution (by weight relative to the total weight of the solution) in acetic acid. The flowrate of introduction of the column inhibitor is adjusted so as to have less than 1000 ppm of inhibitor in the final reactor product.
Sparging with depleted air (8% oxygen and 92% nitrogen by volume) may be carried out throughout the reaction.
The crude product obtained is generally perfectly clear, free of polymers and able to be freed of the head fraction by distillation under reduced pressure (for example of 20 mm Hg) so as to rid it of the excess acetic acid, of (meth)acrylic acid and of the compound formed by reaction of 1 mole of (meth)acrylic acid with 1 mole of acetic anhydride.
The process according to the invention may comprise a further step of distillation of the crude product obtained, where appropriate after removal of the head fraction, on a distillation column or using a short-residence-time machine such as a film evaporator.
EXAMPLES
The examples that follow illustrate the present invention without, however, limiting its scope. The percentages therein are expressed on a mass basis.
The following abbreviations are used therein:
MAA: methacrylic acid AA: acrylic acid MA 2 OA: methacrylic anhydride A 2 OA: acrylic anhydride Ac 2 O: acetic anhydride AcOH: acetic acid Mixed: H 2 C═CHCOOOCCH 3 , or, depending on the case,
H 2 C═C(CH 3 )COOOCCH 3 .
Example 1 (Comparative)
361 g (3.54 mol) of Ac 2 O and 639 g (7.43 mol) of MAA (the molar ratio R 0 is thus 2.1) are introduced into a mechanically stirred reactor heated by circulation of thermostatically-maintained oil in a jacket, and on which is mounted a distillation column containing Multiknit® structured packing having a separation efficacy of 12 theoretical plates, and being able to function under vacuum.
1.09 g of Topanol A are introduced as inhibitor into the reactor, and a solution of 5% Topanol A and 5% HQ in acetic acid is introduced as inhibitor into the column, this solution being added uniformly throughout the duration of the reaction at a rate of 2 ml/h.
Sparging with depleted air (8% oxygen and 92% nitrogen by volume) is maintained in the reactor throughout the operation.
The acetic acid formed is removed gradually as it is formed. The first fraction distilled off is composed of 99.5% acetic acid.
After reaction for 6 hours 30 minutes at 95° C., the crude reaction product has the following composition:
AcOH
0.5%
Ac 2 O
0.06%
MAA
11.8%
Mixed
4.6%
MA 2 OA
81.6%
Side products
1.44%
TOTAL
100%
The amount of MA 2 OA contained in the crude product (measured by weighing at the end of the reaction) is 485 g.
Thus, the degree of conversion of Ac 2 O into MA 2 OA and Mixed is 96.5%.
The final molar ratio R f MAA/Ac 2 O is 2.1; it is identical to the initial molar ratio.
The crude product obtained is then freed of the head fraction under reduced pressure (20 mm Hg) in order to remove therefrom the residual MAA and the Mixed.
The crude product obtained after removal of the head fraction consists of 96.2% MA 2 OA.
Example 2 (According to the Invention)
The process is performed as indicated in Example 1, except that the same mass (1000 g) of overall initial charge of MAA and of Ac 2 O is added to the reactor, but with more MAA and less Ac 2 O being introduced.
The initial charge thus consists of 900 g (10.465 mol) of MAA and 100 g (0.98 mol) of Ac 2 O (the initial molar ratio R 0 is 10.7).
The same inhibitor as in Example 1 is introduced in the same proportion into the reactor.
The same inhibitor solution as in Example 1 is introduced at the same flowrate into the column.
Ac 2 O is introduced uniformly throughout the reaction, gradually as the AcOH is removed, so as to occupy all the space liberated by the said AcOH in the reactor.
Working in this way allows optimum occupation of the reaction volume.
After reaction for 6 hours 30 minutes at 95° C., the amount of Ac 2 O introduced continuously during the reaction was 408 g and the crude reaction product has the following composition:
AcOH
0.4%
Ac 2 O
0.2%
MAA
12.3%
Mixed
7.2%
MA 2 OA
78.8%
Side products
1.44%
TOTAL
100%
The amount of MA 2 OA contained in the crude product (measured by weighing at the end of reaction) is 680 g, for a total amount of reagent used of 1408 g (1000+408).
The final molar ratio R f is 2.1, as in Example 1.
Consequently, the gain in production of MA 2 OA is 40% relative to Example 1, without increasing the reaction time and with the same final molar ratio R f .
Thus, for the same reaction volume (same initial mass of 1000 g), but with a better distribution of the reagents, much more MA 2 OA was produced.
The degree of conversion of Ac 2 O into MA 2 OA and Mixed is 97%.
The crude product obtained after removal of the head fraction is entirely clear, free of polymers and able to be distilled under reduced pressure (20 mm Hg). It consists of 96.4% MA 2 OA.
Example 3 (Comparative) and Example 4 (According to the Invention)
The process as indicated in Examples 1 and 2 is performed, replacing the methacrylic acid with acrylic acid and using a distillation column having an efficacy of 20 theoretical plates.
All the other conditions are identical to those of Examples 1 and 2.
At the end of the 6 hours 30 minutes of reaction at 95° C., the following table may be produced:
Example 4
Example 3
(according to the
Synthesis A 2 OA
(comparative)
invention)
AA charged at the
535
735
start (g)
Ac 2 O charged at the
361
161
start (g)
Total charged at the
896
896
start (g)
Ac 2 O introduced
0
335
continuously during
the reaction
Total charged (g)
896
1231
throughout the
operation
A 2 OA produced (g)
360
497
The gain in production for Example 4 relative to Example 3 is thus 38%.
|
A process for the batchwise preparation of (meth)acrylic anhydride, in which acetic anhydride is reacted with (meth)acrylic acid and the acetic acid is at least partly removed gradually as it is formed. In the process, the acetic acid removed is at least partly replaced by introducing into the reaction medium, during the reaction, acetic anhydride and/or (meth)acrylic acid. The (meth)acrylic anhydride obtained by this process may be used in the synthesis of (meth)acrylic thioesters, (meth)acrylic amides and (meth)acrylic esters, in polymerization reactions or as crosslinking agents.
| 2
|
This application is a continuation of application Ser. No. 740,041, filed May 31, 1985.
TECHNICAL FIELD
This invention relates to a warp knitted stretch fabric suitable for outerwear end used, particularly in trousers, and to a method of knitting an outerwear fabric.
DISCUSSION OF PRIOR ART
In the course of development work to produce such a stretch fabric, trials were carried out involving laying into the warp knitted structure an elastomeric yarn to extend generally in the longitudinal direction of the fabric. The elastomeric yarn first chosen for trial was a bare polyurethane yarn but the fabric produced did not have an acceptable stretch performance. As an alternative, an elastomeric core plied yarn was tried. Such a yarn comprises an elastomeric filament twisted together with a spun yarn. Again the fabric produced was unacceptable in that it had a very rough surface.
The results obtained in the two trials mentioned above could easily have brought the development work to an end but perseverance with a third trial surprisingly showed that the use of a covered elastomeric yarn could produce an acceptable warp knitted fabric for outerwear end uses.
SUMMARY OF THE INVENTION
According to one aspect of the invention a warp knitted outerwear fabric comprising a coherent fabric structure knitted from a ground yarn and an elastic yarn laid into said fabric structure so as to extend generally in the longitudinal direction thereof, is characterised in that the fabric includes at least two covered elastomeric yarns each laid into a respective wale of the fabric with spaced excusions into an adjacent wale, such excursions of one of the covered elastomeric yarns taking place in courses different from such excursions of another, or the other, covered elastomeric yarn.
Preferably, the covered elastomeric yarn is a double covered yarn in which two strands of non-elastomeric covering yarn are separately wound about a core comprising an elastomeric strand.
Said coherent fabric structure may be a single bar structure, preferably a single bar structure with an underlap extending over two needle spaces.
According to a further aspect of the invention there is provided a method of warp knitting a fabric comprising forming a ground yarn into a coherent fabric structure and laying an elastic yarn into said fabric structure so as to extend generally in the longitudinal direction thereof, which is characterised in that the fabric is knitted as an outerwear fabric by steps including threading covered elastomeric yarns on at least two guide bars, causing each guide bar to make lapping movements such as to lay each covered elastomeric yarn into a wale of the fabric but with spaced excursions into an adjacent wale, such excursions of the covered elastomeric yarns laid by one of the guide bars taking place in courses different from such excursions of the covered elastomeric yarn laid by another of the guide bars.
To produce a stretch warp knitted fabric to simulate the appearance of a plain woven fabric, covered elastomeric yarns may be threaded on two guide bars each of which makes lapping movements such as to lay each covered elastomeric yarn into a separate single wale of the fabric with spaced excursions into an adjacent wale, such excursions of the covered elastomeric yarns from one of said two guide bars taking place in courses different from such excursions of the covered elastomeric yarns from the other of said two guide bars.
To produce a stretch warp knitted fabric to simulate the appearance of a twill, covered elastomeric yarns may be threaded on three guide bars each of which makes lapping movements such as to lay each covered elastomeric yarn into a separate single wale of the fabric with spaced excursions into an adjacent wale such that in every second course of the fabric, covered elastomeric yarns from two of said three guide bars make such an excursion but in no adjacent second courses is it the same two covered elastomeric yarns which are making such excursions.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be further described, by way of example, with reference to the accompanying drawing in which:
FIG. 1 is a lapping diagram for a fabric according to the invention simulating a plain woven fabric, and
FIG. 2 is a lapping diagram for a fabric according to the invention simulating a twill.
DESCRIPTION OF PREFERRED EMBODIMENTS
Both fabrics illustrated in the drawing are knitted from a ground yarn constituted by a textured polyester filament yarn and a laid-in covered, low-stretch, elastomeric yarn comprising a polyurethane filament core double covered with cotton yarn, two strands of cotton being separately wound about the polyurethane core.
In FIG. 1, the ground yarn is threaded in guide bar number one and the covered elastomeric yarn is threaded in guide bars numbers two and three. In FIG. 2, the ground yarn is threaded in guide bar number one and the covered elastomeric yarn is threaded in guide bars numbers two, three and four.
The lapping movements used in FIG. 1 are as follows:
______________________________________Guide bar 1 1-0/2-3/1-0/2-3Guide bar 2 0-0/1-1/0-0/2-2Guide bar 3 0-0/2-2/0-0/1-1______________________________________
The lapping movements used in FIG. 2 are as follows:
______________________________________Guide bar 1 1-0/2-3/1-0/2-3/1-0/2-3Guide bar 2 0-0/2-2/0-0/2-2/0-0/1-1Guide bar 3 0-0/1-1/0-0/2-2/0-0/2-2Guide bar 4 0-0/2-2/0-0/1-1/0-0/2-2______________________________________
In both the fabric of FIG. 1 and that of FIG. 2, the ground yarn forms a coherent fabric structure knitted on one fully-threaded guide bar with an underlap extending over two needle spaces.
In FIG. 1, covered elastomeric yarns are fully threaded on each of two guide bars each of which makes lapping movements such as to lay each covered elastomeric yarn into a separate single wale of the fabric but causes it at spaced intervals in the fabric to make excursions into an adjacent wale.
Thus, in FIG. 1, polyester filament ground yarn 5 is knitted in wales 6 and 7 two needle spaces apart so that the underlap in the fabric structure formed by the ground yarn extends over two needle spaces. The covered elastomeric yarns 8 and 9 (representative of the yarns from guide bars two and three respectively) are laid into the fabric of FIG. 1 to extend generally in the longitudinal (that is the wale) direction thereof. In fact, the yarn 8 is laid into wale 10 but in every fourth course of the fabric the second guide bar is moved to carry yarn 8 (and the other yarns threaded in the second guide bar) into the adjacent wale 11 and then back to wale 10. Similarly, the covered elastomeric yarn 9 is laid into wale 12 but in every fourth course of the fabric is carried by the third guide bar into the adjacent wale 13. The movements of the guide bars two and three are arranged so that the excursions of yarn 8 into the adjacent wale 11 take place in courses different from those in which the excursions of the yarn 9 into wale 13 take place and in fact these excursions take place in respect of one or other of the guide bars two and three every two courses so that a balanced fabric structure is produced; a course in which one set of laid in yarns moves to adjacent wales being followed by a course in which neither set does so, and then by a course in which the other set moves to adjacent wales and finally, to complete the cycle, there being a course in which neither set of laid-in yarns moves to adjacent wales.
Since all three guide bars are full-threaded, the ground yarn is knitted in every wale of the fabric and every wale of the fabric also has two covered elastomeric yarns laid into it which gives the fabric good covering power and a high superficial weight appropriate to an outerwear fabric.
In FIG. 2, covered elastomeric yarns are fully threaded on each of the guide bars, two, three and four. Each of the guide bars two, three and four follows a similar pattern of movements in sequence. The lapping movements set out above show that the movements of guide bar three follow, two courses behind, those of guide bar two and the movements of guide bar four follow, two courses behind, those of guide bar three. Each of these three guide bars lays each of its yarns, for example, yarn 14 from guide bar two into a single wale (15) with spaced excursions into an adjacent wale (16). In every second course of the fabric, yarns from two of the three guide bars two, three and four make such an excursion, the sets of yarns making the excursions being always different in adjacent second courses. Thus in course A, FIG. 2, yarns from guide bars two and four make lapping movements which take them to an adjacent wale (from wale 15 to wale 16 in the case of yarn 14). In the next course but one, B, yarns from guide bars two and three make a movement to an adjacent wale and in the next course but one after course B, in course C, the yarns from guide bars three and four make such a movement.
Warp knitted fabrics produced in the manner described above are particularly suitable for outerwear and have better stretch and recovery properties than can be achieved using textured yarns.
The knitted structures according to the invention described herein are such that the covered elastomeric yarn(s) is/are located in a surface of the fabric and thus can contribute to the surface texture and/or appearance of the warp knitted fabric.
|
Warp knitting of a stretch fabric suitable for outerwear end uses and simulating woven fabric is carried out to produce a coherent ground structure comprising non-elastomeric yarn, covered elastomeric yarns being laid into said ground structure.
| 3
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to measuring devices and, more specifically, to a tile measuring device for use in laying tiles and a method therefor.
2. Description of the Related Art
Laying floor tiles is a timely and arduous process. One of the most time consuming steps in laying tiles is the step of custom cutting tiles to fit properly adjacent an obstruction such as a cabinet or a wall.
Typically, floor tilers accomplished custom tile cuts in the following general manner. After laying standard, un-cut tiles over the majority of the floor space of a room, a tiler would need to custom cut standard tiles to fit properly adjacent an obstruction such as a wall. The tiler would use a measuring tape to determine what portion would need to be cut from a standard tile such that the new, custom tile would fit properly adjacent both the wall and any adjacent tiles. Frequently, after completing all of the required measuring and cutting, a tiler discovers that the new, custom tile does not fit properly. This problem is caused by a number of factors such as poor measuring and/or cutting.
Up until now, there has not been a device for quickly, accurately, and easily measuring a standard tile for removing unwanted portions therefrom such that the new, custom tile would fit properly adjacent both an obstruction and any adjacent tiles.
SUMMARY OF THE INVENTION
In accordance with one embodiment of this invention, it is an object of this invention to provide a measuring device.
It is another object of this invention to provide a tile measuring device for use in laying tiles.
It is a further object of this invention to provide a method for tile measurement for use in laying tiles.
It is yet another object of this invention to provide a tile measuring device for quickly, accurately, and easily defining a portion of a tile for removal from the tile such that the tile, after having a portion thereof removed, fits properly adjacent an obstruction.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with one embodiment of this invention, a tile measuring device for use in laying tiles is disclosed comprising, in combination, a support member, reference means slidably coupled to the support member for establishing a reference position for the device with respect to a tile and another tile, and measuring means movably coupled to the support member at a distal end thereof for defining a portion of the other tile relative to the reference position and for permitting the other tile to fit properly adjacent an obstruction after the portion is removed. The reference means is slidable from a proximate end of the support member substantially to the distal end of the support member. Additionally, the reference means further comprises means for fixedly retaining the reference means to the support member at any point from the proximate end substantially to the distal end of the support member. The reference means further comprises a horizontal member portion located substantially orthogonal to the support member and having a slot therein, and spacer bar means extending from the horizontal member portion for insertion between an edge of the tile and an edge of the other tile. The reference means further comprises gage member means slidably retained within the slot for extension from the horizontal member portion, and gage member retaining means coupled to the horizontal member portion for locking the gage member means in place. The slot is provided on a bottom side of the horizontal member portion and the slot extends along the full length of the horizontal member portion. The gage member means is extendable from both a first end and a second end of the horizontal member portion. The measuring means further comprises guide member means for alignment with the obstruction, and rotatable clamping means pivotally coupled to the support member for slidably retaining the guide member means and for rotating the guide member means for the alignment with the obstruction. The rotatable clamping means further comprises means for fixedly retaining the rotatable clamping means with the support member, and means for fixedly retaining the guide member means with the rotatable clamping means.
In accordance with another embodiment of this invention, a method for tile measurement for use in laying tiles is provided comprising the steps of providing a support member, providing reference means slidably coupled to the support member for establishing a reference position for the device with respect to a tile and another tile, and providing measuring means movably coupled to the support member at a distal end thereof for defining a portion of the other tile relative to the reference position and for permitting the other tile to fit properly adjacent an obstruction after the portion is removed.
The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiments of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the tile measuring device for use in laying tiles.
FIG. 2 is a cross sectional view taken along the line 2--2 of FIG. 1.
FIG. 3 is a cross sectional view taken along the line 3--3 of FIG. 1.
FIG. 4 is a cross sectional view taken along the line 4--4 of FIG. 3.
FIG. 5 is a plan view of the tile measuring device set up in a particular reference position with respect to both a tile and an obstruction.
FIG. 6 is a plan view of the tile measuring device set up in the reference position of FIG. 5 in order to cut a tile which will then fit properly with respect to the tile and the obstruction from FIG. 5.
FIG. 7 is a plan view of one of the configurations of the tile measuring device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a tile measuring device is shown and is generally designated by reference number 10. A tile 12 and another tile 14 are laid on a floor 16. An obstruction 18 such as a wall or a cabinet is also shown. The tile measuring device 10, or more simply the device, has a support member 20 which supports a reference portion 22 and a measuring portion 23 of the device 10.
The reference portion 22 has a horizontal member portion 24 which is located below and substantially orthogonal to the support member 20. The reference portion 22 has another member portion 26 coupled to the horizontal member portion 24. Note that the member portion 26 is partially located below the support member 20, however, another part of the member portion 26 extends above the support member 20 for slidably retaining the support member 20. A plate 29 and a bolt 28 are coupled to the member portion 26 for fixedly retaining the member portion 26, and thereby the reference portion 22, to the support member 20. The reference portion 22 can be slid from a proximate end 20p substantially to a distal end 20d (see FIG. 2) of the support member 20. Accordingly, the reference portion 22 can be fixedly retained via the bolt 28 and the plate 29 from the proximate end 20p substantially to the distal end 20d of the support member 20.
The bottom side of the horizontal member portion 24 has a slot 32 and a spacer bar 30. Both the slot 32 and the spacer bar 30 run along the entire lengthwise dimension of the horizontal member portion 24. The spacer bar 30 is inserted between an edge of tile 12 and an edge of tile 14 in order to form a space therebetween. After the tiles 12 and 14 have adhered to the floor 16, the space therebetween is filled with grout. The horizontal member portion 24 has a bolt 34 inserted therein for locking a gage member 52 (see FIG. 3) within the slot 32.
The measuring portion 23 of the device 10 has a guide member 38 for alignment with an obstruction. The measuring portion 23 also includes a rotatable clamp 40 which is pivotally coupled to the support member 20. The rotatable clamp 40 slidably retains the guide member 38, and the rotatable clamp 40 rotates the guide member 38 for alignment with an obstruction. The rotatable clamp 40 is provided with bolts 46 and a plate 44 for locking the guide member 38 with respect to the rotatable clamp 40. The rotatable clamp 40 is also provided with a bolt 42 and a member 43 for locking the rotatable clamp 40 into a position with respect to the support member 20.
Referring to FIG. 2, the guide member 38 is connected to the rotatable clamp 40 via the combination of the plate 44, the bolts 46, and angled portions 38a and 44a. As the bolts 46 (only 1 seen in this view) are loosened, the guide member 38 is permitted to slide in a linear manner along the track formed by angled portions 38a and 44a. When the guide member 38 has been slid into a desired position, the bolts 46 are tightened in order to lock the guide member 38. The rotatable clamp 40 is pivotally coupled to the support member 20 with a bolt 48. When the bolt 42 is loosened, the rotatable clamp 40 is free to rotate about the bolt 48, thereby rotating the guide member 38 into a desired angular position. When the guide member 38 is in the desired angular position, the bolt 42 is tightened, and, therefore, the member 43 locks the rotatable clamp 40 via contact at surface 43b. Note that the member 43 is coupled to the support member 20 at 43a. Also, note that when the rotatable clamp 40 is locked into a desired angular position, the guide member 38 is locked into the desired angular position. Thus, the rotatable clamp 40 permits one to both move the guide member 38 in a linear motion and to move the guide member 38 in a rotational motion until the guide member 38 is in a desired position.
Referring to FIG. 3, a cross sectional view shows the location of the support member 20 relative to the reference portion 22. Note that the horizontal member portion 24 extends below the support member 20. In FIG. 1, two bolts 50 are shown for connecting the spacer bar 30 to the horizontal member portion 24. One of these two bolts 50 is shown in FIG. 3. The slot 32 is shown to slidably retain gage member 52. The gage member 52 may be slid in both directions along the slot 32, and, therefore, the gage member 52 may be extended from either end of the horizontal member portion 24. Once the gage member 52 has been extended to a desired position, the bolt 34 is tightened in order to lock the gage member 52. In FIG. 1, the bolt 34 is shown near the right end of the horizontal member portion 24, however, note that on the left side of the horizontal member portion 24, there is another hole for a bolt 34. Thus, a single bolt 34 may be used on either the left or the right side of the horizontal member portion 24. Alternatively, one bolt 34 could be used for the left side of the horizontal member portion 24 and another bolt 34 could be used for the right side of the horizontal member portion 24.
Referring to FIG. 4, member portion 26 is shown to retain support member 20. The plate 29 is coupled to the member portion 26 such that when the bolt 28 is tightened, the plate 29 clamps down upon surface 29a in order to lock the position of the reference portion 22 with respect to the support member 20. Alternatively, the bolt 28 may be loosened in order to permit one to slide the reference portion 22 along the support member 20 until the reference portion 22 is in a desired position whereby one would then lock the reference portion 22 in place.
Referring to FIG. 7, in order to show some of the possible movements for the device 10, the guide member 38 is shown shifted to the right and the gage member 52 is shown shifted to the left. Obviously, there are many different possible arrangements of an obstruction 18 that may require unusual positions of the device 10, however, since the device 10 can be moved into many different positions, the device 10 is exceptionally useful in conforming to any one of a number of different obstructions. Consequently, a user can quickly and easily custom cut a tile for installation into a difficult location.
OPERATION
Referring to FIGS. 5 and 6, assume that the tiles 12a and 12b have already been laid in a manner well known to those skilled in the tiling art. Now, in order to lay a tile in the space between the tile 12a and the obstruction 18, one must create a custom tile 14 by removing a portion 14a therefrom. The specific structural details of the support member 20, the reference portion 22, and the measuring portion 23 have previously been disclosed, therefore, further detailed description of the mechanics of the device 10 will be limited. Moreover, the manner in which the various structural elements of the device 10 interact in order to permit movement and locking of the device 10 has also been previously disclosed. Thus, no further detailed description of the movement and of the locking of the device 10 is necessary.
Referring to FIG. 5, the spacer bar 30 (not shown in this view) is held with a back edge 30b (see FIG. 3) thereof flush against the top edge 12c of the tile 12a. The support member 20 is slid up through member portion 26 until the guide member 38 is aligned with the obstruction 18. The gage member 52 is extended from the right end of the horizontal member portion 24 until an edge 52a of the gage member 52 is aligned with an edge 12d of the tile 12a. Thus, in this case, the desired reference position is a combination of having the back edge 30b of the spacer bar 30 flush against the top edge 12c of the tile 12a, having the guide member 38 aligned with the obstruction 18 as shown, and having the edge 52a of the gage member 52 aligned with the edge 12d of the tile 12a. With the device 10 in the desired reference position, the bolts 42, 34, and 28 are tightened in order to lock the device 10 into the reference position. In this case, the bolts 46 are already tightened, however, if they were not tightened, then one would tighten them in order to maintain the desired reference position. The aforementioned movements of the device 10 may occur in a different order, however, the device 10 must be properly aligned and then locked into the desired reference position as shown and described.
Referring to FIG. 6, one uses the device 10, which has been locked into the reference position from FIG. 5, to define a portion 14a for removal from the tile 14. Specifically, the front edge 30f (see FIG. 3) of the spacer bar 30 is held flush against the bottom edge 14b of the tile 14, and the edge 52a of the gage member 52 aligned with the edge 14c of the tile 14. With the device 10 in this reference position relative to the tile 14, one marks tile 14 along the edge 38a of the guide member 38. After marking the tile 14, the unwanted portion 14a is removed by a cutting process well known to those skilled in the tiling art. Now, the remaining portion of the tile 14 has been custom cut to fit properly between the tile 12a and the obstruction 18. Note that this type of custom cut of the tile 14 will provide a grout line between tile 12a and tile 14 having a thickness approximately equal to the thickness of the spacer bar 30. Additionally, this type of custom cut of the tile 14 will result in a nearly flush fit between the obstruction 18 and the tile 14. In order to provide a grout line having a thickness approximately equal to the thickness of the spacer bar 30 between the tile 14 and the tile 12a and between the tile 14 and the obstruction 18, a similar procedure is implemented, with one exception. Rather than aligning the front edge 30f of the spacer bar 30 with the edge 14b of the tile 14, one aligns the front edge 24a of the horizontal member portion 24 flush with the edge 14b of the tile 14.
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 the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention. For example, the device 10 could be used to make angled cuts in dry wall construction.
|
A tile measuring device for use in laying tiles is disclosed comprising a support member, a reference member portion, and a measuring member portion. The reference member portion is slidably coupled to the support member for establishing a reference position for the device with respect to a tile and second tile. The measuring member portion is movably coupled to the support member at a distal end thereof for defining a portion for removal from the second tile relative to the reference position. Removal of this undesired portion from the second tile permits the second tile to fit properly adjacent an obstruction after the undesired portion is removed.
| 1
|
TECHNICAL FIELD
[0001] The present invention relates to a method of filling containers with gases. More particularly, the present invention relates to a method of filling containers with predetermined amounts of first and second gases.
BACKGROUND OF THE INVENTION
[0002] It is known to provide an inflator for inflating an inflatable vehicle occupant protection device. One particular type of inflator is a heated gas inflator. In a heated gas inflator, a combustible mixture of gases is stored under pressure in a gas storage chamber. The heated gas inflator may include an outlet that is closed by a burst disk. An igniter assembly is associated with the gas storage chamber and is actuatable to ignite the combustible mixture of gases. When the combustible mixture of gases is ignited, the pressure of the gases within the gas storage chamber increases. The increased pressure ruptures the burst disk enabling the gases to exit the inflator through the outlet.
[0003] The combustible mixture of gases in a heated gas inflator generally includes hydrogen, an inert gas, and air. Actuation of the igniter assembly ignites the hydrogen to heat the inert gas and the air. Typically, the combustible mixture of gases has a precise amount of hydrogen. For example, the amount of hydrogen in the combustible mixture of gases may have a tolerance of approximately 0.001 grams. Additionally, since the molecular weight of hydrogen is low, the total mass of the hydrogen in the combustible mixture of gases may be less than one gram. When the total mass of the empty inflator is, for example, 1000 grams, adding less than one gram of hydrogen, with a tolerance of approximately 0.001 grams, tends to be difficult.
[0004] Currently, the process for adding the combustible mixture of gases to the inflator is time consuming and labor intensive. The process includes placing an empty inflator on a high precision scale and determining the mass of the empty inflator. The scale must be protected from air drafts, vibrations, and other variables that may alter the measured weight and thus, the determined mass, of the inflator. After the mass of the empty inflator is determined, hydrogen is introduced into the gas storage chamber of the inflator. After the hydrogen is added to the inflator and the scale has stabilized, the mass of the inflator and the stored hydrogen is determined. If the additional mass of the hydrogen is outside of the required tolerance, the amount of hydrogen in the gas storage chamber is adjusted and a subsequent determination of the mass of the inflator and the stored hydrogen is made.
[0005] When the amount of hydrogen added to the inflator is within its required tolerance, the inert gas is added to the gas storage chamber of the inflator. Generally, the combustible mixture of gases also has a precise amount of the inert gas. The inert gas is added to the gas storage chamber of the inflator using the same process as was used to add the hydrogen. After the precise amount of the inert gas has been added to the inflator, air is added to the gas storage chamber of the inflator to bring the pressure within the gas storage chamber to a predetermined level. When the pressure within the gas storage chamber reaches the predetermined level, the fill port for the gas storage chamber is sealed.
SUMMARY OF THE INVENTION
[0006] The present invention relates to a method of filling containers with gases. Each container, when filled, includes a first predetermined amount of a first gas and a second predetermined amount of a second gas. The method comprises the steps of: forming a mixture comprising first and second amounts of the first and second gases, respectively. The first and second amounts are greater than and are in proportion to the first and second predetermined amounts, respectively. The method also comprises the steps of: determining a sum of the first and second predetermined amounts; and adding a third amount of the mixture to each of the containers. The third amount is equal to the sum of the first and second predetermined amounts.
[0007] In accordance with another aspect, the present invention relates to a method of filling inflators with gases. Each inflator, when filled, includes a first predetermined amount of a first gas and a second predetermined amount of a second gas and is actuatable for inflating an inflatable safety device of a vehicle safety system. The method comprises the steps of: forming, in a mixing vessel, a mixture comprising first and second amounts of the first and second gases, respectively, wherein a ratio of the first amount to the second amount equals a ratio of the first predetermined amount of the first gas to the second predetermined amount of the second gas; determining a sum of the first and second predetermined amounts; and adding a third amount of the mixture to each of the inflators. The third amount is equal to the sum of the first and second predetermined amounts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The foregoing and other features of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which:
[0009] FIG. 1 illustrates an inflator that has been filled with a combustible mixture of gases, in accordance with the method of the present invention;
[0010] FIG. 2 illustrates a vehicle safety system having the inflator of FIG. 1 ;
[0011] FIG. 3 schematically illustrates an apparatus for filling the inflator of FIG. 1 ; and
[0012] FIGS. 4A and 4B are schematic block diagrams illustrating a process of filling inflators, in accordance with the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] FIG. 1 illustrates an inflator 10 that has been filled with a combustible mixture of gases 12 , in accordance with the method of the present invention. The inflator 10 illustrated is a heated gas inflator. The combustible mixture of gases 12 is stored under pressure in a gas storage chamber 14 of the inflator 10 . Alternatively, the inflator 10 may be any type of inflator that includes a mixture of gases stored under pressure in a gas storage chamber 14 .
[0014] FIG. 2 illustrates a vehicle safety system 18 having the inflator 10 of FIG. 1 . The vehicle safety system 18 of FIG. 2 includes an inflatable safety device. The inflatable safety device of FIG. 2 is an inflatable curtain 20 . The inflator 10 , when actuated, provides inflation fluid for inflating the inflatable curtain 20 . As an alternative to an inflatable curtain 20 , the inflatable safety device may include an inflatable air bag, an inflatable seat belt, an inflatable knee bolster, an inflatable headliner, or a knee bolster operated by an inflatable air bag.
[0015] The inflatable curtain 20 of FIG. 2 is in a deflated condition and is stored within a housing 22 at a location adjacent both the side structure of a vehicle 26 and a roof of the vehicle. The side structure of the vehicle 26 includes an A-pillar 28 , a B-pillar 30 , a C-pillar 32 , and side windows 34 and 36 , respectively. FIG. 2 shows four brackets 40 securing the housing 22 and the inflatable curtain 20 to the side structure of the vehicle 26 .
[0016] A conduit 44 connects the inflator 10 to the inflatable curtain 20 . Upon actuation of the inflator 10 , inflation fluid flows through the conduit 44 and into the inflatable curtain 20 . In response to receiving the inflation fluid, the inflatable curtain 20 deploys from the deflated condition to an inflated condition to cover portions of the side structure of the vehicle 26 , such as side windows 34 and 36 .
[0017] As shown in FIG. 1 , the inflator 10 includes a cylindrical, metal container 50 . The container 50 includes a tubular body portion 52 having cylindrical inner and outer surfaces 54 and 56 , respectively, and opposite first and second ends 58 and 60 , respectively. An igniter end cap 66 closes the first end 58 of the tubular body portion 52 . The igniter end cap 66 includes an annular flange portion 68 that is fixed to the tubular body portion 52 and an igniter support portion 70 that supports an actuatable igniter 74 . The igniter support portion 70 of the igniter end cap 66 includes a passage 76 through which combustion products produced by actuation of the igniter 74 may pass. Prior to actuation of the igniter 74 , a rupturable burst disk 78 closes the passage 76 .
[0018] A diffuser end cap 84 closes the second end 60 of the tubular body portion 52 . The diffuser end cap 84 includes a tubular end portion 86 having inner and outer surfaces 88 and 90 , respectively. A circular gas fill port 92 extends through the tubular end portion 86 of the diffuser end cap 84 . The diffuser end cap 84 also includes an end portion 96 that includes an annular end wall portion 100 and a tubular discharge portion 102 . The tubular discharge portion 102 of the end portion 96 extends axially away from the annular end wall portion 100 in a direction parallel to an axis A. The tubular discharge portion 102 includes a passage 106 that provides an exit path for inflation fluid to flow out of the container 50 .
[0019] Prior to actuation of the igniter 74 , a rupturable burst disk 110 closes the passage 106 of the tubular discharge portion 102 of the diffuser end cap 84 . The burst disk 110 is designed to rupture when subjected to a predetermined pressure differential.
[0020] The tubular body portion 52 , the igniter end cap 66 , and the diffuser end cap 84 collectively define the gas storage chamber 14 . The gas storage chamber 14 extends along axis A between the igniter end cap 66 and the diffuser end cap 84 . The inner surface 54 of the tubular body portion 52 and the inner surface 88 of the tubular end portion 86 of the diffuser end cap 84 define a radial outer boundary of the gas storage chamber 14 .
[0021] When the igniter 74 of the inflator 10 receives an actuation signal from electronic circuitry 114 ( FIG. 2 ) of the vehicle safety system 18 , the igniter 74 is actuated. Combustion products from actuation of the igniter 74 travel through the passage 76 in the igniter end cap 66 , rupture the burst disk 78 , and enter the gas storage chamber 14 . The combustion products heat and ignite the combustible mixture of gases 12 that is stored under pressure within the gas storage chamber 14 . The heating and ignition of the combustible mixture of gases 12 increases the pressure within the gas storage chamber 14 . When the predetermined pressure differential across the burst disk 110 is reached, the burst disk 110 is ruptured. Inflation fluid resulting from heating and igniting the combustible mixture of gases 12 exits the inflator 10 through the passage 106 of the tubular discharge portion 102 of the diffuser end cap 84 .
[0022] FIG. 3 schematically illustrates an apparatus 120 for filling the inflator 10 with a combustible mixture of gases. As an example, the apparatus 120 of FIG. 3 will be described as filling the inflator 10 with a combustible mixture of gases that includes hydrogen, argon, and air. The apparatus 120 of FIG. 3 illustrates three vessels 122 , 124 , and 126 . Vessel 122 contains a stored quantity of hydrogen gas, under pressure. Vessel 124 contains a stored quantity of argon, under pressure. Vessel 126 contains a stored quantity of air, under pressure.
[0023] The apparatus 120 also includes a mixing vessel 130 . The mixing vessel 130 has a volume that is significantly greater than the volume of the gas storage chamber 14 of the inflator 10 . In a preferred embodiment of the invention, the volume of the mixing vessel 130 is over one thousand times greater than the volume of the gas storage chamber 14 of the inflator 10 .
[0024] A conduit 134 connects vessel 122 to the mixing vessel 130 . A valve 136 attaches the conduit 134 to the mixing vessel 130 . When the valve 136 is open, hydrogen flows into the mixing vessel 130 . A conduit 140 connects vessel 124 to the mixing vessel 130 . A valve 142 attaches the conduit 140 to mixing vessel 130 . When the valve 142 is open, argon flows into the mixing vessel 130 .
[0025] FIG. 3 illustrates a scale 146 that is associated with the mixing vessel 130 . The scale 146 is used for monitoring the amounts of hydrogen and argon in the mixing vessel 130 . The amounts of hydrogen and argon that are mixed together in the mixing vessel 130 are proportional to predetermined amounts of hydrogen and argon in the combustible mixture of gases 12 contained in the inflator 10 . For example, assume that a ratio of the predetermined amount, by mass, of hydrogen in the combustible mixture of gases 12 to the predetermined amount, by mass, of argon in the combustible mixture of gases 12 is 1/33. The ratio of the amount, by mass, of hydrogen and the amount, by mass, of argon that are mixed together in the mixing vessel 130 is also 1/33. The amounts of hydrogen and argon mixed together in the mixing vessel 130 , however, are significantly greater than the predetermined amounts used to fill one inflator 10 . In a preferred embodiment, the mixing vessel 130 holds enough hydrogen and argon to fill over one thousand inflators.
[0026] To ensure a proper mixture of the hydrogen and argon in the mixing vessel 130 , the scale 146 is used to determine the mass of the empty mixing vessel 130 . The valve 136 is then opened and a quantity of hydrogen flows into the mixing vessel 130 . The valve 136 is closed and the scale 146 is used to determine mass of the hydrogen that was added to the mixing vessel 130 . Since the amount of hydrogen added to the mixing vessel 130 is preferably enough to fill over one thousand inflators, the added hydrogen will have a sufficient mass so as to be easily monitored using the scale.
[0027] After the amount of hydrogen that was added to the mixing vessel 130 is determined, the amount of argon to be added to the mixing vessel 130 is calculated. The amount of argon to be added to the mixing vessel 130 is determined from the ratio of the predetermined amount of hydrogen to the predetermined amount of argon in the combustible mixture of gases 12 and from the determined amount of hydrogen so that mass ratio of hydrogen to argon in the mixing vessel 130 is equal to the mass ratio of hydrogen to argon to be added to the inflator, e.g., a mass ratio of 1/33.
[0028] With reference again to FIG. 3 , the apparatus 120 also includes a member 150 for temporarily attaching to the inflator 10 . The member 150 includes first and second input lines 152 and 154 , respectively, and a single output line 156 . A first valve 160 is associated with the first input line 152 . A second valve 162 is associated with the second input line 154 .
[0029] A conduit 166 connects the mixing vessel 130 to the first valve 160 . When the first valve 160 is open, a mixture of hydrogen and argon flows into the first input line 152 of the member 150 and is directed into the gas storage chamber 14 of the inflator 10 . As a result, when the first valve 160 is open, hydrogen and argon are added simultaneously to the gas storage chamber 14 of the inflator 10 .
[0030] A conduit 168 connects the vessel 126 to the second valve 162 . When the second valve 162 is open, air flows into the second input line 154 of the member 150 and is directed into the gas storage chamber 14 of the inflator 10 .
[0031] To fill the inflator 10 with the combustible mixture of gases 12 , the member 150 is secured to the inflator 10 so that the output line 156 of the member directs a flow of gas through the fill port 92 ( FIG. 1 ) and into the gas storage chamber 14 of the inflator 10 .
[0032] Next, the sum of the predetermined amounts of hydrogen and argon is determined. For purposes of example, assume that the inflator 10 is a 180 cm 3 inflator that holds approximately 75 grams of the combustible mixture of gases 12 . Also, for purposes of example, assume that the combustible mixture of gases 12 includes 12% by volume hydrogen, 20% by volume argon, and 68% by volume air. When filled with the combustible mixture of gases 12 , the inflator 10 will hold approximately 0.65 grams of hydrogen, 21.47 grams of argon, and 52.88 grams of air at a pressure of 6000 p.s.i. to 7000 p.s.i.
[0033] As set forth in the Background of the Invention, adding such a small mass of hydrogen to the inflator, with a tolerance of approximately 0.001 grams, tends to be difficult. Instead of adding the approximately 0.65 grams of hydrogen to the inflator 10 and then later adding the approximately 21.47 grams of argon, the hydrogen and argon are simultaneously added to the inflator 10 according the method of the present invention.
[0034] In our example, the determined sum of the predetermined amounts of hydrogen and argon equals approximately 22.12 grams (the sum of 0.65 grams and 21.47 grams). After the sum of the predetermined amounts is determined, an amount of the mixture of hydrogen and argon equal to the sum of the predetermined amounts, e.g., 22.12 grams, is added to the gas storage chamber 14 of the inflator 10 . A scale 174 is used for determining the amount (mass) of the mixture of hydrogen and argon that has been added to the inflator 10 .
[0035] Since both the hydrogen and the argon have associated tolerances, assuming the proportion of the hydrogen and argon in the mixture is proper (e.g., a ratio of 1/33) and assuming that the mixture of hydrogen and argon flowing into the inflator 10 is homogenous, the tolerance for the mixture of hydrogen and argon will be larger than the individual tolerances for the hydrogen and the argon. For example, if the tolerance for the hydrogen is 0.001 grams and the tolerance for the argon is 0.005 grams, the tolerance for the mixture of hydrogen and argon may be greater than 0.005 grams while still maintaining the proper amounts of hydrogen and argon in the inflator 10 . This results from the fact that the hydrogen only accounts for approximately 1/34 (0.65 grams H 2 /22.12 grams mixture) of the total added mass of the mixture and the argon only accounts for 33/34 (21.47 grams Ar/22.12 grams mixture) of the total added mass. Thus, when the amount of the mixture of hydrogen and argon added to the inflator 10 is within a 0.005 gram tolerance, the amount of hydrogen added is within its 0.001 gram tolerance (0.005 grams times 1/34 equals 0.000147 grams) and the amount of argon added is also within its 0.005 gram tolerance (0.005 grams times 33/34 equals 0.000485 grams).
[0036] After the mixture of hydrogen and argon is added to the gas storage chamber 14 of the inflator 10 , the second valve 162 is opened and air is added to the gas storage chamber 14 of the inflator 10 . the scale 174 is used to determine the weight of the air added to the storage chamber 14 of the inflator 10 . After the air is added to the inflator, the fill port 92 of the inflator 10 is closed and the inflator is removed from the apparatus 10 . FIG. 1 illustrates a closure member 180 closing the fill port 92 of the inflator 10 .
[0037] FIGS. 4A and 4B are schematic block diagrams illustrating a process 400 of filling inflators. For purposes of example, the discussion of FIGS. 4A and 4B will refer to the example given above, i.e., an inflator holding 75 grams of a combustible mixture of gases of which approximately 0.65 grams is hydrogen, approximately 21.47 grams is argon, and approximately 52.88 grams is air.
[0038] As shown in FIG. 4A , the process 400 begins at step 402 . At step 404 , a first gas, e.g., hydrogen, is added to the mixing vessel 130 . At step 406 , the amount of the first gas added to the mixing vessel 130 is determined. To determine the amount of the first gas added to the mixing vessel 130 , the mass of the mixing vessel 130 , when empty, is determined prior to the first gas being added. The mass of the mixing vessel 130 is then determined after the addition of the first gas. The difference between the two determined masses represents the mass of the first gas added to the mixing vessel. Step 406 does not require any precise amount of the first gas to be added to the mixing vessel 130 as long as the amount of first gas added is greater than a predetermined amount for filling one inflator. As set forth above, the amount of the first gas added to the mixing vessel 130 is preferably enough to fill a large number of inflators, such as one thousand inflators. For purposes of example, assume that 700 grams of hydrogen was added to the mixing vessel 130 at step 406 .
[0039] At step 408 , the amount of the second gas, e.g., argon, to be added to the mixing vessel 130 is calculated. The mass ratio of the first and second gases in the mixing vessel 130 should be equal to the mass ratio of the predetermined amounts of the first and second gases in the inflator. In our example, the mass ratio of hydrogen to argon is 1/33. Thus, the amount of argon to be added to the mixing vessel 130 at step 408 equals thirty-three times the amount of hydrogen added at step 406 . In our example, 700 grams of hydrogen was added to the mixing vessel 130 at step 406 . Therefore, at step 408 , the calculated amount of the argon is 23.1 kilograms.
[0040] At step 410 , the calculated amount of the second gas is added to the mixing vessel 130 . At step 412 , the amount of the second gas added to the mixing vessel 130 is determined. To determine the amount of the second gas added to the mixing vessel 130 , the mass of the mixing vessel 130 after the addition of the second gas is determined. The previously determined mass of the mixing vessel 130 after the addition of the first gas and prior to the addition of the second gas is subtracted from the determined mass of the mixing vessel 130 after the addition of the second gas. The difference between the two determined masses represents the mass of the second gas added to the mixing vessel 130 .
[0041] At step 414 , a determination is made as to whether the correct amount of the second gas has been added to the mixing vessel 130 . The determination at step 414 is made by comparing the determined amount of the second gas added to the mixing vessel 130 from step 412 to the calculated amount of the second gas from step 408 . When the determined amount of the second gas added is within a predetermined tolerance of the calculated amount of the second gas, the determination at step 414 is affirmative.
[0042] In response to a negative determination at step 414 , the process 400 proceeds to step 416 and the amount of the second gas in the mixing vessel 130 is increased if the amount of the second gas is too low. The amount of the second gas can not become too high, because the systems (in a manner not shown), is constantly being monitored by continually weighing the second gas in the mixing vessel and closing off the flow of the second gas when the correct weight is in the mixing vessel 130 . From step 416 , the process 400 returns to step 414 . In response to an affirmative determination at step 414 , the process proceeds to step 418 .
[0043] At step 418 , the sum of the predetermined amounts of the first and second gas to be added to an inflator is determined. In our example, the predetermined amount of the first gas, hydrogen, is 0.65 grams and the predetermined amount of the second gas, argon, is 21.47 grams. Therefore, the sum of the predetermined amounts that is determined at step 418 is 22.12 grams grams.
[0044] As shown with reference to FIG. 4B , the process 400 proceeds from step 418 to step 420 . At step 420 , an empty inflator is inserted into the apparatus 120 . When the empty inflator is inserted into the apparatus 120 , the member 150 of the apparatus 120 for directing gases into the inflator is connected to the inflator so as to direct gases through the fill port of the inflator and into the gas storage chamber. At step 422 , a mass of the empty inflator is determined.
[0045] At step 424 , the mixture of the first and second gases is added to the inflator. The amount of the mixture added to the inflator is the amount determined at step 418 . At step 426 , the amount of the mixture of the first and second gases added to the inflator is determined. To determine the amount of the mixture added to the inflator, the mass of the inflator after the addition of the mixture of gases is determined. The previously determined mass of the empty inflator is subtracted from the determined mass of the inflator after the addition of the mixture of gases. The difference between the two determined masses represents the mass of the mixture of gases added to the inflator.
[0046] At step 428 , a determination is made as to whether the correct amount of the mixture of gases has been added to the inflator. The determination at step 428 is made by comparing the determined amount of the mixture of gases added to the inflator from step 426 to the determined sum from step 418 . When the determined amount of the mixture of gases added is within a predetermined tolerance of the determined sum, the determination at step 428 is affirmative.
[0047] In response to a negative determination at step 428 , the process 400 proceeds to step 430 , and the amount of the mixture of gases in the inflator is adjusted by either adding or removing an amount of the mixture. From step 430 , the process 400 returns to step 428 . In response to an affirmative determination at step 428 , the process 400 proceeds to step 432 . At step 432 , a predetermined amount of air is added to the inflator. As noted above the air added to the inflator is weighted. The air increases the pressure of the gases in the gas storage chamber of the inflator to a predetermined pressure. At step 434 , the fill port of the inflator is closed and sealed and, at step 436 , the inflator is removed from the apparatus.
[0048] From step 436 , the process 400 proceeds to step 438 . At step 438 , the amount of the mixture of the first and second gases remaining in the mixing vessel 130 is determined. The amount of the mixture remaining may be determined by monitoring the total mass of the mixing vessel 130 and the mixture of gases. At step 440 , a determination is made as to whether the remaining amount of the mixture of gases is greater than the sum of the predetermined amounts from step 418 . When the determination at step 440 is affirmative, and the amount of the mixture of gases remaining in the mixing vessel 130 is greater than the sum of the predetermined amounts from step 418 , the process 400 proceeds to step 442 and another empty inflator is inserted into the apparatus 120 to be filled. From step 442 , the process 400 returns to step 422 . When the determination at step 440 is negative, the process 400 proceeds to step 444 and ends.
[0049] From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. For example, nitrogen may be used in the process as a substitute for argon. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.
|
A method of filling containers ( 50 ) with gases ( 12 ) provides each container, when filled, with a first predetermined amount of a first gas and a second predetermined amount of a second gas. The method comprises the step of forming a mixture comprising first and second amounts of the first and second gases, respectively. The first and second amounts are greater than and are in proportion to the first and second predetermined amounts, respectively. The method further comprises the steps of: determining a sum of the first and second predetermined amounts; and adding a third amount of the mixture to each of the containers. The third amount is equal to the sum of the first and second predetermined amounts.
| 1
|
This application is a continuation of U.S. Ser. No. 08/601,490, filed Feb. 14, 1996, which is a continuation of U.S. Ser. No. 08/333,944, filed Nov. 3, 1994, which is a continuation of U.S. Ser. No. 07/998,457, filed Dec. 30, 1992, which is a continuation-in-part of U.S. Ser. No. 07/753,185, filed Aug. 30, 1991 all abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an apparatus for digitizing transparencies or negatives in a desk-top computer environment and, more particularly, to such an apparatus designed to accommodate images presented as individually mounted slides, negatives in strips, or roll material.
2. Related Background Art
Image digitizers and their associated image processing workstations have grown in popularity. Individual graphic designers, advertisers, realtors and news reporters are incorporating this kind of image acquisition into their daily work. These digitizers or scanners are typically connected to computers for use in conjunction with desk-top publishing programs.
In addition, an image digitizer can be installed in a color copier, color printer, color facsimile machine or portable image transmission system. Further, a large part of the proofing can be accomplished by digitizing and sending the film data to a monitor.
A user typically purchases a scanner based upon cost, ease of use, performance and reliability. Desirable features are that it should not occupy considerable desk space. It should provide high performance, but still be affordable. If the decision is for a transparency scanner, the unit should be able to process negatives in their native format, namely uncut strips of 4 to 6 frames. Some users, such as stock photography houses, art galleries or museums, have a need to digitize large numbers of images for cataloging, archiving, or transmission over telephone lines.
SUMMARY OF THE INVENTION
One object of the present invention is the provision of a system which is inexpensive, compact, rugged and accurate. In order to be inexpensive, it must be easily assembled and not require critical alignment.
A further object is the implementation of a single assembly which includes all of the mechanical and optical components of the transparency digitizing system.
A further object is to provide a calibrated mechanical angular adjustment of images on the film before digitization.
A further object is to both accept and eject media through a front loading opening.
A further object is to accept an elongate film strip through a front loading opening and to discharge the strip through a second opening, preferably in the rear of the unit.
A further object is the capability to manage large numbers of individual images without the need for operator interaction.
An image digitizing system of the present invention for reading and digitizing an image of an original document is characterized by comprising an original holding member for holding the original document and having an opening to be used for reading the original document, drive means for moving the original holding member when the original document is read, and eject means for ejecting the original document out of the original holding member upon completion of reading of the original document.
Also, an image digitizing system of the present invention for focusing an image of an original document on a line sensor and reading said image on the original document in a line form to be digitized is characterized by comprising an original holding member for holding the original document and having an opening to be used for reading the original document, a guide member consisting of rods extending in the axial direction for guiding a movement of the original holding member, drive means for driving the original holding member along the guide member when the original document is read, focus means for performing focusing adjustment of the image of the original document in the original holding member on the line sensor, and eject means for ejecting the original document out of the original holding member upon completion of reading of the original document.
As described above, according to the image digitizing system of the present invention, an original document can be ejected out of the original holding member easily upon completion of the reading of the original document. Also, since said image digitizing system has the focus means, an image of the original document in the original holding member can be focused on the line sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention is described in detail below with reference to the accompanying drawings, in which:
FIG. 1 is a fragmentary diagrammatic perspective view of a transport mechanism according to the invention, including a motor/drive assembly;
FIG. 2A is a diagrammatic perspective view of an outer part of a slide jacket which is a component of the mechanism of FIG. 1, including structure which provides angular adjustment and automatic ejection of a slide;
FIG. 2B is a diagrammatic perspective view of an ejector and tilt bar which are components of the slide jacket of FIG. 2A;
FIG. 3 is a fragmentary diagrammatic perspective view of a cam arrangement with manual and servo control allowing fine focus adjustments;
FIG. 4 is a diagrammatic perspective view which shows an adaptor used to handle negatives in strips;
FIG. 5 is a diagrammatic perspective view of part of a variation of the embodiment of FIG. 1 which permits continuous processing of frames on a film roll;
FIGS. 6A to 6C are cross-sectional diagrammatic views showing an eject mechanism of a film in response to a movement of a carriage;
FIG. 7 is a fragmentary diagrammatic perspective view of another embodiment of the transport mechanism and the fine focus adjustment mechanism; and
FIG. 8 is a cross-sectional diagrammatic view showing a focusing mechanism according to the other embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed to a system of the general type disclosed in Applicant's copending Ser. No. 07/619,663 filed on Nov. 28, 1990 and entitled METHOD AND APPARATUS FOP RAPID SCANNING OF COLOR IMAGES, which is a continuation-in-part of Applicant's abandoned U.S. Ser. No. 07/511,649 filed on Apr. 20, 1990. The disclosure of each of these two prior applications is hereby incorporated herein by reference. The system disclosed in the prior applications includes mechanical, optical and electrical portions. The present invention relates to an improved mechanical arrangement for handling film which bears images to be digitized. The optical and electrical portions of the system embodying the present invention are effectively identical to the optical and electrical portions of the system disclosed in the two prior applications, and the optical and electrical portions are therefore not described herein in detail.
In practice, transparencies or slides 200 are typically framed in 50×50 millimeter mounts, while negatives are typically processed in strips of 4, 5 or 6 images. The preferred embodiment is disclosed with reference to these specific formats, but it will be recognized that the invention can be used with other formats.
Drive Mechanism
Attention is now drawn to FIG. 1, which illustrates pertinent mechanical parts of the system. A conventional stepper motor 101 is secured to a flange of a housing 102 which accommodates the entire scanning apparatus. Electrical components and optical components such as a light source, various mirrors, an imaging lens and a detector array have been omitted for clarity. The motor 101 has a shaft bearing a small gear 111, which meshes with a larger idler gear 112 fixedly secured to a shaft 121. The gears 111 and 112 could alternatively be replaced with a friction drive or an arrangement employing a belt and pulleys. The idler gear 112 rotatably drives the shaft 121, which is rotatably supported on the housing by two bearings 123 and 124. The shaft 121 also carries two pinions 125 and 126 which each mesh with a respective longitudinally movable rack 131 or 132. The two racks are rigidly connected to a transport carriage 201.
The transport carriage 201 is guided for reciprocal movement by a guide arrangement of rods 141-142 and bearings, which is equivalent to that disclosed in the above-mentioned prior applications. The guide arrangement is therefore described only briefly here. In particular, a pair of upper rods 141 are disposed above and extend approximately parallel to a pair of lower rods 142. The ends of the upper rods 141 remote from the front panel 151 are supported by the carriage which has its racks 131 and 132 supported by the pinions 125 and 126, which permits the ends of rods 141 adjacent the front panel 151 to move vertically a small amount. The lower rods 142 are supported at their ends adjacent the front panel by not-illustrated springs of the type disclosed in the above-mentioned prior patent, so that the ends adjacent to the front panel can move vertically a small amount. The transport carriage 201 includes an upper shell 201a having spaced bushing-like bearings slidably supported on the upper rods 141, and a lower shell 201b having spaced bushing-like bearings slidably supported on the lower rods 142. The upper rods 141 are each biased downwardly by a respective spring, one of which is shown in FIG. 1 at 143, thereby also urging the carriage downwardly so that the racks 131 and 132 are urged downwardly against the pinions, which in turn ensures that the gear teeth of the racks and pinions are fully in engagement without any significant play in order to provide zero backlash.
In the preferred embodiment the transport has the following pitch:
Motor 3.6° per full step
Idler gear ratio 1:3
Number of pinion teeth=12 with a 0.3 (metric) module
Driving the stepper with 32 mini-steps per 360 electrical thus yields a 0.15° rotation of the pinion per mini-step, and a 5 micron per mini-step feed resolution for the carriage.
The drive system provides enough friction so that, in conjunction with the gear ratio, the carriage 201 will remain in a fixed position even if the motor is not energized. This allows manual insertion of a slide 200 whenever the carriage is in its home position nearest the front panel 151, even if the motor has no power.
The pinions 125 and 126 act as a pivot axis about which the racks can rotate. This pivot axis and the pivot provided by a focussing cam 301 ensure that the piece of film being digitized is always kept at a uniform height regardless of variations in the thickness of the frames in which different pieces of film are mounted. The carriage assembly 201 is limited in its forward travel by the front panel 151. As to rearward travel, there is no direct limit on rearward travel of the carriage itself, but rearward travel of an ejector 211 is limited by a pair of claws 161 and 162 on the housing which can engage the ejector 211 of the carriage.
Eject Operation
In order to perform a scanning operation, the entire slide 200 is pushed into the unit through a narrow slotlike passageway or opening 152 in the front panel 151. This opening is kept small in order to positively key the slide to the proper position, to minimize the entry of dust, and to protect the detector array from ambient light. Once the slide is inside the scanning apparatus, it is inaccessible to the user. A mechanism must therefore be provided to eject the slide at the end of scanning.
FIG. 2A illustrates the eject mechanism. The above-mentioned ejector 211 (FIG. 2B) is located inside a slide jacket 221. The ejector 211 carries stops 212, against which the slide is seated. When a slide is manually inserted, the slide pushes stops 212 and ejector 211 rearwardly. The final position of the stops is determined by a tilt bar 231, which is described below.
During scanning of a slide, the motor 101 moves the carriage 201 far enough to expose the entire slide image to the optical components, so that the system can digitize the entire image field. Typically, this travel is 36 mm. If the user has specified via software that the slide is to be ejected, the software causes the control circuit to control the motor so as to move the carriage 201 an additional 14 mm. At the start of this over-travel, the ejector 211 engages the claws 161 and 162, which are part of the housing 102. The carriage 201 will thus continue its travel while the ejector 211, the stops 212 and the slide are held in a predetermined place. The ejector 211 is held in a predetermined place vertically and sideways by its shape, which mates with the shell of the carriage 201. Along the axis of travel the ejector can travel approximately 14 mm. Forward travel is limited by a cutout 203 (FIG. 2A) formed in the carriage upper shell 201a, and rearward travel by a tilt bar 231. The stationary slide is therefore pushed partially out of the carriage 201 by the amount of carriage over-travel. When the transport direction is then reversed and the carriage is brought to its home position adjacent front panel 151, the slide will extend out of the opening 152 by the amount of over-travel. The operator can thus comfortably remove it from the unit. The ejector is manually returned to its original position when a new slide is manually inserted.
The ejector 211 has several elongate slits 213. The pattern in which slits 213 are arranged is used as a code to differentiate whether the ejector or the slide frame is in the optical path, and allows the system to determine if the carriage is loaded with a slide. In particular, when the carriage is in its home position, the region which is imaged onto the detector array corresponds to a line extending across the portion of the ejector 211 which has the slits 213, and the system can examine the detected image for a pattern of bright and dark line segments corresponding to the slits. If the detector array senses black in this part of the image, a slide must be in the carriage since the slide mount will obstruct the optical path. If no slide has been inserted, either zero attenuation (i.e. maximum light source intensity) or the code pattern of the ejector (pattern of light and dark line segments) is detected.
On power-up, an eject operation is automatically executed to eject any slide which might have been left in the carriage inadvertently or which might be stuck because of a hang-up.
Emergency Ejector
Since it is always conceivable that power might suddenly fail completely during system operation, the apparatus also features a manual emergency ejector 241, which is shown in FIG. 2A. The emergency ejector is seated in a recess in the front panel 151 and is thus accessible from the outside. In the case of a crash, the carriage 201 could be located in any position along its path of travel. The emergency ejector 241 pulls the carriage 201 all the way forward to its home position against the front panel 151. Since the emergency ejector 241 engages the ejector stops 212, the slide will extend out of the opening 152 in the front panel.
Rotational Adjustment
For many applications, the exact orientation of the slide is not critical. For these applications, the edges of the window in the slide mount are a sufficient reference for the horizontal and vertical major axes. In some applications, however, the image orientation is more critical. For example, technical, architectural and product images often require precise angular orientation.
Since software rotation is very time-consuming and can degrade the image quality, the present invention avoids software rotation by providing precise mechanical adjustment of the angular orientation before scanning. FIG. 2A is again used for the purpose of illustration. The sidewalls of the jacket 221 have been formed to provide a wide slide receiving channel (about 52 mm in the preferred embodiment) for easy slide insertion. At the center of each side of the jacket is a convex protrusion 202, the distance between the two protrusions 202 being substantially the exact width of a slide frame. The protrusions 202 thus center the slide, while permitting it to be rotated a few degrees about a central vertical axis.
The ejector stops 212, which positively position the slide, are not fixed in their location relative to the carriage but are capable of some limited adjustment. This adjustment is effected by the tilt bar 231 which defines the angular position of the ejector 211 and thus of the stops 211 thereon. This tilt bar is pivotally supported on the slide jacket by a vertical rivet 233, which gives the tilt bar the ability to pivot a few degrees about a vertical axis. The angular orientation of the tilt bar can be adjusted by a screw 232 which is rotatably supported on and extends the length of the outer slide jacket, which is held against axial movement relative to the slide jacket, and which threadedly engages a threaded hole in a flange of the tilt bar 231 at a location spaced radially from the rivet 233. When the carriage is in its home position, the head of this screw becomes accessible from the outside through a small hole in the front panel.
The operator uses this feature in the following manner. The image is scanned in the normal position. If a critical reference line appears tilted in the resulting digitized image, the user will measure the angle of tilt in the image, either with a software tool or with a conventional ruler or protractor. The adjustment is calibrated by providing one degree of tilt per single full screw rotation. With this capability, the slide or negative carrier can be accurately aligned to the sensor when positively seated against the stops.
In a simplified alternative version of this arrangement, the ejector 211 could rest against the rivet 233 without the provision of the adjustment screw 232. While not providing calibrated rotational adjustment, this still allows the slide to be rotated about its center.
Fine Focus/Autofocus
The focusing arrangement is illustrated in FIG. 3. The interaction of the upper rods 141 and lower rods 142 with the transport carriage 201 ensures that most slides do not need any focusing adjustment. Regardless of the thickness of the mount, the film is always kept vertically centered. However, if the user is scanning glass-mounted slides, the optical path will be lengthened. There are also some exotic mounts in which the film is not centered. Additionally, one might want to purposely defocus the image for special effects. For these cases, a manual and motorized focus control is provided.
In the preferred embodiment, focussing is accomplished by adjusting the height of the front ends of the upper rods 141. These rods are supported at their front ends in respective grooves 302 machined into an elongate focussing cam member 301 which is supported on housing 102 for rotation about its lengthwise axis, the grooves 302 being eccentric to the axis of rotation. The focussing cam member can be rotated manually by a focus knob 303 which projects through a slot in the front panel 151. The focus knob 303 has a stop 304 which can engage the front panel 151 to limit its rotation. The film can be raised or lowered approximately 1 millimeter by cam member 301. It is further possible to couple the cam member 301 through a friction clutch 312 having a pinion to a worm gear 311 driven by a stepper motor 321, allowing for automatic focusing.
Adaptor for Negative Strips
The use of a transparency digitizer for the purpose of scanning negatives is highly desirable. While slides are framed in 50×50 mm mounts, negatives are typically kept as film strips of up to six frames per strip. This format is advantageous for both archiving and handling. A scanning system which required cutting and mounting of individual negative frames would be disadvantageous and undesirable.
The preferred embodiment has been designed to accommodate film strips, in the following manner. As shown in FIG. 4, an adaptor 401 can support a negative strip and can be inserted into the scanning apparatus. This adaptor has a central area which resembles a slide mount, in that it has a 24×36 mm opening 402. The user centers the particular frame of the film strip to be scanned within this opening. The first three frames of a six-frame strip can be scanned in their proper orientation. The length of the scanner allows it to receive only about half of the length of the film strip, and therefore to scan the remaining three frames the strip is physically reversed in the adaptor 401. Images will thus be scanned from the reverse strip upside down, and after scanning the resulting image has to be flipped digitally so that the data is in the proper format. Software capable of flipping a digital image is known and is not a part of the present invention, and therefore is not described here in detail. As shown in FIG. 4, the opening 402 has at one end a triangular extension 403. This extension exposes a border area 411 of the film located between two frames. Before digitization of the image data, the scanning apparatus can sample the density in this unexposed area to establish a black reference.
The rear portion of the adaptor, which is inserted first into the scanning apparatus, is 40 mm wide, which is enough to accept the 35 mm film width but also leaves 5 mm on either side for retention by the ejector stops 212 (FIG. 2). The rear portion has a length sufficient to accommodate two additional frames beyond the frame being scanned. The opposite or front end of the adaptor is long enough so that a part of it always projects out of the scanning apparatus to protect the film in any position, and has the width of a standard slide mount, namely 50 mm. The adaptor 401 has upper and lower shells or plates, the lower shell having upwardly projecting pins 421 which mate with holes 422 in the upper shell to facilitate the alignment of the negative strip by virtue of the pins on opposite sides or the opening 402 being spaced by a distance which is the width of a standard film strip. The upper and lower shells of the adaptor are pivotally coupled for ease of handling, for example by a hinge. Offset cutouts 423 in the upper and lower shell of the adaptor along an edge of each opposite from the hinge facilitate opening of the carrier.
This or a similar adaptor can also be used to manage single unmounted slide frames, or other transparent material such as dental X-ray films or glass microscope slides.
Inside the scanning apparatus, two important features facilitate use of the adaptor 401. Referring to FIG. 1, the stops 212 which positively orient the slide mount are spaced by a distance sufficient for film and carrier to pass. Also, there must be enough depth clearance toward the rear to allow unobstructed passage for the length of the adaptor. Typically, the adaptor penetrates into the scanning apparatus beyond the scanning area by at least two additional frames of 38 mm each.
Carousel Extension
In some applications, it is desirable to automatically scan a large number of slides. The use of a standard straight or carousel tray is therefore indicated. The disclosed scanning apparatus can operate in any orientation, and for this application it is located underneath the tray with the carriage traveling vertically. For a tray scanning station, the carriage assembly is implemented in a slightly different fashion. The ejector provides essentially a solid back wall for the jacket. The path of travel of the carriage is increased to include transporting the slide from inside the tray to the scanning position. After each full scanning cycle, a feed ratchet automatically advances the tray to the next position. Such an arrangement can digitize a 120 slide carousel in about 6 hours for off-line batch digitization.
Scanning of Roll Material
In another application for volume scanning, image data is stored on an elongate film strip having 24, 36 or more exposures. A variation of the disclosed embodiment which accommodates this application is shown in FIG. 5. In conjunction with the passage provided for the negative strip carrier, a rear opening 501 and an adaptor or chute 511 to guide the film have been added to allow handling of entire film strips or larger reels.
The adaptor 511 guides the film material in the pull-in direction. A set of two spaced sprocket wheels 521 and associated pinch rollers 522 retain the film when the carriage returns to its home position. In particular, the sprocket wheels include a ratchet mechanism 523 of a conventional type which allows the film to advance when the carriage moves in the feed direction, but keeps it from moving in the opposite direction as the carriage returns. The sprocket wheel and pinch roller assembly can be releasably snapped to the front panel. The scanning apparatus can automatically advance to the next frame. By analyzing the image data from scanning, the system can also automatically recognize frames that are placed irregularly on the film due to camera idiosyncrasies. This embodiment efficiently scans slide or negative film and finds application in laboratories and stock photography houses.
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.
In this regard, it will be recognized that the apparatus and method described above are directly applicable to a variety of image digitization tasks including different formats, monochrome films and even opaque originals. The preferred embodiment applies them specifically to the digitization of 35 mm color transparencies or negatives, but this is not to be considered limiting.
The eject mechanism described above with reference to FIG. 2A will be described in full with reference to FIGS. 6A to 6C.
Note that the ejector 211 and the claw 161, which are protruding upwardly from the carriage 201 in FIG. 2A, are protruding downwardly in FIGS. 6A to 6C.
FIG. 6A illustrates a state when the slide 200 is housed in the carriage 201 and before the claw 161 which is part of the housing collides with the ejector 211, i.e., a state after the reading of the image data is completed.
FIG. 6B illustrates a state in which the carriage 201 has been driven by the motor to travel further rearwardly from the state in FIG. 6A. Even after the claw 161 collides with the ejector 211, the carriage 201 continues to travel rearwardly further. On the other hand, the ejector 211 remains at the fixed position since it engages the claw 161. Therefore, the slide 200 which is in contact with the stop 212 of the ejector 211 also remains at the fixed position. Thus, the slide 200 is displaced fowardly relative to the carriage 201 as the carriage moves rearwardly.
FIG. 6C is a view showing a state in which the carriage 201 has been driven by the motor to travel toward the front panel from the position in FIG. 6B. Since the slide 200 has been displaced in a forward direction relative to the carriage 201, when the carriage 201 reaches the edge of the front panel by the driving of the motor, the slide 200 is protruding from the opening 152. Therefore, the operator can remove the slide from the unit.
Another embodiment will be described next. When an image is read only in one direction so that there is no problem of backlash, a drive mechanism as shown in FIG. 7 can be provided. The embodiment in FIG. 1 employs two racks and two pinions. However, the embodiment shown in FIG. 7 has only one rack and one pinion in a set, pivoting upon one end of paired lower rods. Differences from the embodiment in FIG. 1 will be specifically explained below.
One rack 131 is formed on the carriage 201. A pinion 125 which engages said rack 131 is provided. Since the rack is arranged on one side of the carriage, it is no longer necessary to adjust engagement and engaging positions between the racks and pinions on both sides as in the previous embodiment, which results in a simple assembling and adjustment. Also, very high precision is not required for gears and parts for installing the gears.
In the present embodiment, the rear end of the lower rod 142 (at a position remote from the opening) is arranged to be in contact with a lower rod receiving portion 181. Focusing is accomplished by using a contact point between said lower rod and the lower rod receiving portion as a fulcrum for rotation.
Full description will be made with reference to FIG. 8. An upper carriage 201a is brought into contact with an upper rod 141. A slide 200 is inserted between said upper carriage 201a and a lower carriage 201b. The lower carriage 201b is in contact with the lower rod 142. When the upper rod 141 is biased downwardly by a spring 143, the lower rod 142 is biased downwardly through the upper carriage 201a, the slide 200 and the lower carriage 201b. Therefore, the lower rod 142 is biased toward the lower rod receiving portion 181 of the housing 102. In this case, a position of engagement between the rack 131 and the pinion 125 and a position at which the end of the lower rod 142 is in contact with the lower rod receiving portion 181 are approximately aligned with each other in the longitudinal direction and the vertical direction. Thus, even when the focusing position is vertically moved by a cam member 301, backlash between the rack 131 and the pinion 125 does not change.
Therefore, when the focus knob 303 is rotated, the focusing position of the slide 200 changes by using the lower rod receiving portion 181 as a fulcrum for rotation.
|
A transporting system for an image digitizer can handle both positive and negative transparent film material. The transport features accurate linear motion with high resolution in a single compact unit. For the processing of individually framed slides, an automatic eject mechanism is provided. Both manual and motor driven focus adjustments are provided. Individual images can be oriented by an angular adjustment option. A special carrier allows the system to process negatives in uncut strips. The transport can manage larger number of images using either a slide tray or roll feed attachment.
| 7
|
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for molding thin disc substrata, for example in DVD.
DESCRIPTION OF THE RELATED TECHNOLOGY
Today consumers prefer DVD optical discs, which are capable of storing more digital information than a compact disc but on the disc size of a compact disc, 120 mm diameter. The DVD disc has two discs laminated as shown in FIG. 6. Two disc substrata 11, 12, each of which is 0.6 mm in thickness, are laminated by adhesive layer 18 so that information surfaces 13, 14 are face-to-face.
In DVD disc molding, to achieve low birefringence the occurrence of residual stress must be avoided. However, it is found that in molding to avoid residual stress the melted resin does not sufficiently reach to the outer periphery of the cavity, or the outer periphery portion of the disc is molded thinner than the central portion. Injection molding of DVD disc substrata 120 millimeters in diameter and 0.6 millimeter thick has been tried by conventional injection molding methods, but it has been found that the melted resin incompletely filled to the outer periphery of the disc or the thickness was not even.
Japanese Opened Patent Application 60-67124, entitled "Mold and stamper for injection molding plastic disk as carrier of high density information recording", refers to molding of discs with less residual stress. It discloses injection molding in which melted resin is injected through a sprue into the disc cavity in the closed mold under control of the speed and pressure of injected melted resin, wherein the thickness of the disc cavity is large in proportion to its diameter.
Another publication is U.S. Pat. No. 5,720,994, which discloses a mold for molding disc substrata in which an inserting block protrudes slightly into the molding cavity.
The DVD-9 (dual layer) standard, which regulates the thickness of DVD discs, specifies the thickness deviation as less than 10 microns (10 -3 millimeters). In addition, it is required that molded discs with have birefringence less than +100 nm, and preferably less than 70 nm, in double pass measurement, in order that pit signals can be accurately read on the information area of the discs.
SUMMARY OF THE INVENTION
Accordingly, the present invention has an object, among others, to overcome deficiencies in the prior art such as noted above.
In light of the above mentioned problems, it is another object of the present invention to provide a novel method and a mold for molding thin DVD discs with even thickness in rapid molding cycles.
A further object of the present invention is to provide a novel method and a mold for molding discs with even thickness and with lower residual stress in rapid molding cycles in order to improve the optical properties of the discs.
A further object provide a novel method and mold for saving maintenance costs of the movable mirror plate.
Other objects and features of the present invention will become apparent to those skilled in the art from the following specification in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The above and other objects and the nature and advantages of the present invention will become more apparent from the following detailed description of an embodiment taken in conjunction with drawings, wherein:
FIG. 1 is a sectional elevation of the moldhalves of the present invention in which the gradient of depth of the cavity is brought about by the surface gradient of the back-up plate.
FIG. 2 is a fragmentary enlarged sectional elevation of the movable mirror plate and the movable back-up plate of FIG.1.
FIG. 3 is a sectional elevation of the moldhalves in another embodiment of the present invention in which the gradient of depth of the cavity is brought about by a spacer inserted on the outer periphery of the flange of the inserting block.
FIG. 4 is a fragmentary enlarged sectional elevation of the movable mirror plate, the movable back-up plate, and the spacer of FIG. 3.
FIG. 5 is a perspective view of a molded disc indicating the positions where the thickness of the measured.
FIG. 6 is a sectional view of a completed DVD disc.
FIG. 7 is a graphical view representing the value of birefringence in the present invention and conventional method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described detailed by way of example, with reference to the accompanying drawings.
Referring to FIG. 1, moldhalves 100 for injection compression molding of DVD disc substrata are shown, including a stationary mold-half 20 and a movable mold-half 30. The stationary mold-half 20 includes a stationary base plate 25 and a stationary outer cylindrical plate 28 which is fixed on the side surface of the stationary base plate 25. A stationary mirror plate 21 is stacked on a stationary back-up plate 26 and these plates are fixedly inserted together into the inner periphery of the stationary outer cylindrical plate 28. A sprue bushing 24 with a stem 24a is fixedly inserted into each bore provided in the center portion of the stationary base plate 25, the stationary back-up plate 26, and the stationary mirror plate 21. A female cutter 23 is fixedly inserted on the outer periphery of the stem 24a, which has an inner hole 24b. An inner stamper retainer 22 is inserted on the outer periphery of the female cutter 23. A stamper 29 is retained on the surface of the stationary mirror plate 21 by the inner stamper retainer 22 and an outer stamper retainer 39. The stamper 29 may be retained on the movable mold-half 30 if need be.
A movable moldhalf 30 includes a movable base plate 37, a movable outer cylindrical plate 40 which is fixed on the side surface of the movable base plate 37, and a movable mirror plate 31 stacked on a movable back-up plate 38. These plates being fixedly inserted into the inner periphery of the movable outer cylindrical plate 40.
An inserting block 33 is fixedly inserted concentric with a circular central opening 32 of the movable mirror plate 31. An ejector sleeve 34, a male cutter 35, and a center ejector pin 36 are assembled and inserted together into an inner periphery of the inserting block 33. The inserting block 33 has a flange 33a and a tip surface 33s protruding 10 μm to 70 μm from the mirror surface 31s of the movable mirror plate 31 into a disc cavity C, in which the disc is molded.
When the mold is closed the disc cavity C is bounded by the surface of the stamper 29, the front surface of the inner stamper retainer 22, the front surface of female cutter 23, the front surface of the sprue bushing 24, the surface of the movable mirror plate 31, the front surface of the inserting block 33, the front surface of the ejector sleeve 34, the front surface of the male cutter 35, and the inner peripheral surface of the outer stamper retainer 39.
The outer periphery surface 31e of the movable mirror plate 31, on which the inner peripheral surface 39a of the outer stamper retainer 39 makes contact, is 120 mm in diameter and the inner periphery surface 32 of the movable mirror plate 31, in which the inserting block 33 is inserted, is 40 mm in diameter. In the present invention, the surface of the stamper 29 mounted on the stationary mirror plate 21 is kept flat and the surface 31s of the movable mirror plate 31 is inclined in order to increase the depth of the cavity C in proportion to the diameter of the outer periphery of the movable mirror plate 31 from the periphery of the central opening 32 of the movable mirror plate 31. The surface 31s of the movable mirror plate 31 is preferably inclined at a gradient of Y/R (as shown in the cross section of FIG. 2), wherein Y is from 5 μm to 30 μm and R is 40 mm.
However, if the surface 31s of movable mirror plate 31 is machined with a gradient and is flawed, its repair would be more difficult and expensive than repairing a flat movable mirror plate. Therefore, in one embodiment of the present invention, shown in FIG. 1 and FIG. 2, the surface 31s of the movable mirror plate 31 is flat when unstressed but the surface 38s of the movable back-up plate 38 is inclined at a gradient of Y/R as shown in FIG. 2, wherein Y is 5 μm to 30 μm and R is 40 mm. The movable mirror plate 31 with the flat surface is fastened by bolts B2 on the surface 38s of the movable back-up plate 38 and by the force of the bolts is bent to a gradient of Y/R, resulting in increasing the depth of the cavity C in proportion to diameter in the range of the outer periphery of the movable mirror plate 31, or, from the periphery of the central opening 32 of the movable mirror plate 31 outward.
The dot-dashed line in FIG. 2 may also represent that the back of the mirror plate 31 is beveled.
FIG. 3 and FIG. 4 shows another embodiment of the present invention, in which neither the surface 31s of the movable mirror plate 31 nor the surface 38s of the movable backup plate 38 is inclined. To make the gradient of Y/R on the surface of the movable mirror plate 31 when mounted, at least one spacer 41 of a doughnut or ring shape is inserted on or near the outer periphery of the flange 33a of the inserting block 33. Then the movable mirror plate 31 and the movable back-up plate 38 are fastened to the movable base plate 37 by the bolts B2, again resulting in increasing the depth of the cavity C in proportion to diameter in the range of the periphery of the central opening 32 to the outer periphery of the movable mirror plate 31.
The number of spacers 41, the thickness, and the outer diameter or diameters of the spacer 41 are defined by the required gradient of the surface of the movable mirror plate 31. In this embodiment the thickness of the spacers 41 are in the range of 10 to 40 μm and the gradient of the surface of the movable mirror plate 31 is Y/R as shown in FIG. 4, wherein Y is 5 μm to 30 μm and R is 40 mm. The spacer thickness in the non-compressed state of course depends on its stiffness or resistance to compression as compared to the stiffness against deformation of the mirror plate 31.
The figures show cross sections of the surfaces of the stamper 29 or mirror plate 31 in a longitudinal cross section, i.e. a section on a plane in which the mold axis of symmetry lies. It will be seen that the mirror plate 31 comprises a substantially frusto-conical molding surface, the conical axis of which is coincident with the mold axis and the disc axis, which lie within the section planes. The frusto-conical molding surface lies at an angle to the axes, as seen in the drawing.
The gradient angle may be defined as that between the conical or longitudinal axis and a perpendicular to the axis, having a sine defined by the fraction Y/R. That is, Y is the distance, measured in a direction parallel to the axis, from the apex of the cone to a point on the periphery of the frusto-conical surface; and R is the distance, measured perpendicular to the axis, from the axis to the same point on the periphery of the frusto-conical surface. The same meanings apply in the following claims. The same meanings apply in the following claims. The invention includes any deliberate angle whose sine is between about 0 and about 0.001. Because the angles are small, this is essentially the same as the angle being between 0 and 0.001 in radian measure. Because of the gradient or angle, the depth of the cavity C increases toward the outer periphery 31e.
Naturally, the mirror plate 31 may assume a shape which, while remaining substantially frusto-conical, can also be curved in the longitudinal cross section which is shown in the drawing. This may come about due to the radial stiffness function of the mirror plate 31. The same is of course true of the stamper 29, if that is alternatively a conical element (or if both the stamper 29 and mirror plate 31 are substantially conical). The present invention includes predetermined stiffness/elastic or plastic mechanical bending characteristics to provide optimal or desired substantially frusto-conical shapes adapted to different resins or conditions.
Given that the invention includes substantially frusto-conical surfaces whose surface angle may thus vary somewhat as a function of radius (distance from the axis), the invention Includes any deliberate set of angles, the sines of which are between about 0 and about 0.001.
In the above-described embodiments of the present invention, the gradient in the cavity depth and the protrusion of the inserting block from the mirror plate are provided on the side of the movable mirror plate 31. However, the present invention is not limited to locating these features on the movable mirror plate 31, or to placing both on the same side of the mold (movable or stationary). If the stamper is provided on the movable mirror plate 31, then above-described gradient and protrusion would have to be provided on the surface of a mirror plate opposite to the surface of the stamper, or a back-up plate under it. It is also within the scope of the present invention that the stamper may be bent.
In operation, polycarbonate resin is used for an injection compression molding of the invention. The temperature of the heating barrel of the injection molding machine preferably is set at 380 degrees centigrade on its front portion, at 360 degrees centigrade on its middle portion, and at 280 degrees centigrade its rear portion. The temperatures of the stationary mirror plate 21 and the movable mirror plate 31 preferably are both set at 110 degrees centigrade. The temperatures of the female cutter 23, the sprue bushing 24, the ejector sleeve 34, and the male cutter 35 are preferably all set at 40 degrees centigrade. A predetermined amount of resin, plasticized in the heating barrel, is injected into the cavity C of the closed moldhalves 100 through the inner hole 24b of the sprue bushing 24.
The resin is injected into the cavity C at a high injection rate and then held at a holding pressure. Simultaneously the moldhalves 100 opens slightly because the force of the injected resin acts against the surface 31s of the movable mirror plate 31 in the cavity C and overcomes the clamping force. Preferably the clamping force is then increased, resulting in closing the moldhalves 100. In one embodiment of the invention the first, lower clamping force is set at two tons and the second, higher one is set at seventeen tons. The second clamping force causes the injected resin to be spread from the center of the cavity C.
The behavior of the compressed resin in the cavity C is affected by the presence of the slight protrusion and the gradient of the movable mirror plate surface. When the resin injected into the cavity C is compressed by the higher clamping force, the injected resin on the tip surface of the inserting block 33 is compressed intensively owing to the presence of the protrusion of the inserting block 33 and it is spread toward the outer periphery of the cavity C where the injected resin has not yet flowed.
Just as the hydraulic resistance of a large pipe is less than that of a small pipe, so the flow resistance of the compressed resin decreases as the cross area of the cavity C increases (due to the gradient of the surface 31s of the movable mirror plate 31). The flow resistance decreases with increasing diameter. Furthermore, there is no reverse flow of the compressed resin into the sprue hole 24b. The flow resistance is of course relatively higher near the center.
Thus a combination of the gradient of the movable mirror plate surface, the protrusion of the tip surface of the inserting block, and injection compression molding results in improving the optical property of the molded discs.
After the resin is compressed, the male cutter 35 is advanced to make the central opening 15 of the disc. Then the moldhalves opens for ejector sleeve 34 to eject the molded disc.
Table 1 shows the thickness of discs molded by injection compression molding of the present invention. The measured positions are on points of different diameters along the A-, B-, C-, and D-lines of the molded disc as shown in FIG. 5.
TABLE 1______________________________________position On A-line On B-line On C-line On D-lineDiameter mm mm mm mm______________________________________ 45 mmΦ 0.608 0.606 0.608 0.609 80 mmΦ 0.608 0.606 0.606 0.609115 mmΦ 0.611 0.607 0.607 0.612______________________________________
As will be understood from the data of Table 1, the 0.006 mm of deviation is within the 10 micron value required by the regulations for the standard DVD-9 (dual layer).
FIG. 7 graphs comparative birefringence values, as measured by the double pass method, for discs made by the injection compression molding of the present invention and by conventional injection molding. The horizontal axis and the vertical axis represent the diameter and birefringence of the molded disc, respectively. The solid line represents the disc of the present invention and the broken line represents the conventional-method disc. The birefringence was measured in the range of an information area of the disc 43 mmΦ to 115 mmφ.
The minimum birefringence value is -55 nm in the present invention and -99 nm with the conventional method.
As mentioned above, the present invention includes a novel method and apparatus for molding thin disc substrata which results in injection compression molding the discs with low birefringence and even thickness in combination with a gradient in depth of the cavity and a slight protrusion of the tip surface of the inserting block into the cavity. Aside from the improved disc quality the present invention reduces maintenance costs for the movable mirror plate by using a movable back-up plate with a gradient or using at least one spacer 41 of a doughnut shape inserted on the outer periphery of the flange 33a of the inserting block 33.
In the present invention the stamper may be mounted on either the movable or the fixed side of the mold.
The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. The means and materials for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means and materials for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention.
Thus the expressions "means to . . . " and "means for . . . " as may be found in the specification above and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical or electrical element or structure may now or in the future exist which carries out the recited function, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above; and it is intended that such expressions be given their broadest interpretation.
|
A mold for injection molding thin discs for DVD has a cavity (C) bounded by a information-bearing stamper (29) surface, a mirror plate (31) opposite to the stamper surface, and the tip (33s) of an inserting block (33) at a central opening in the mirror plate. The tip surface (33s) protrudes into the cavity past the surface of the mirror plate between 10 μm and 70 μm. The mirror plate molding surface is slightly frusto-conical, with a gradient Y/R gradually increasing the depth of the cavity toward the periphery. R is approximately 40 mm and Y lies in the range of 5 μm and 30 μm. The mirror plate is preferably manufactured flat on the surface facing the mold, but bolted down onto a frusto-conical backing plate or on top of a central ring, so that it is stressed into the desired shallow cone shape. The invention includes a method of injecting resin with lower clamping force of about 2 tons and then applying a higher force of about 17 tons.
| 8
|
BACKGROUND OF THE INVENTION
The invention is an improvement in the fuel-air charging system for a loop charged two-stroke engine typical of those used in outboard motors. Such systems usually include at least two main input transfer passages and one or more boost passages. Over the years much effort has gone into improving scavenging in these engines by either enlarging, multiplying or changing the shape of such passages as well as the pistons and combustion chambers to achieve a better flow of fresh charge into the engine and thereby gain more power and increased efficiency. An example of this effort in regard to cross-charged engines is U.S. Pat. No. 3,494,335 issued to H. R. E. Meier in 1968.
As in all well developed arts, there is a continuing effort not only to improve performance but also to simplify design and develop methods of manufacture to reduce cost. This invention is a step forward in each of these areas as it teaches a highly efficient cylinder and piston combination designed specifically to be compatible with high pressure die casting of aluminum engine cylinder blocks.
One problem encountered in designing a cylinder of the type described herein, where the input passages are channels in the cylinder wall, is how to direct at least a portion of the incoming charge across the face of the piston -- as well as up into the combustion chamber -- and thereby more effectively scavenge the burned charge. In the prior art this problem has been solved typically by forming the input passage within the cylinder block which provided lateral room for the passage to be curved from upright to horizontal before discharging into the cylinder. This cannot be done with passages open to the cylinder, consequently, prior to the invention, performancce was sacrificed to gain the cost advantage of this latter construction. The piston and cylinder design of the invention overcomes this deficiency while preserving the economy of construction.
SUMMARY OF THE PRESENT INVENTION
Basically the invention comprises a piston for a cylinder of a loop charged two-stroke engine having its top annular edge beveled or curved, rather than sharp as in the prior art, at least in those portions of its circumference which overlap the input passages of the cylinder; and the combination of said piston and a cylinder construction where said input passages are open channels which may be formed in the cylinder walls during high pressure die casting of the engine block.
The primary advantage of the piston of the invention is that, in the environment of input passages described, it significantly improves scavenging of the spent charge in the combustion chamber by the incoming fuel-air charge and thereby increases volumetric efficiency of the engine at all speeds, but particularly at low rpm.
A further advantage of the invention is that it teaches a completely die castable cylinder structure that has input flow characteristics comparable to those of cylinders having input passages outside the cylinder walls, which cylinders are much more difficult and expensive to produce.
Another advantage of the cylinder of the invention is that it is more compact than cylinders having input ports that course through the cylinder block, so that an engine constructed according to the teaching herein will be smaller and lighter than those of prior design and yet produce as much or more horsepower per pound.
Other objectives, advantages, and various further features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross-sectional view of a piston and cylinder of the invention taken along line 1--1 of FIG. 2.
FIG. 2 is a bottom view of a cylinder of the invention.
FIG. 3 is a vertical cross-sectional view of the boost passage of the cylinder of the invention taken along line 3--3 of FIG. 2.
FIG. 4 is a vertical sectional view of a charging passage of the invention taken along line 4--4 of FIG. 2.
FIG. 5 is a vertical sectional view taken along line 5--5 of FIG. 2 illustrating a charging passage of the invention.
FIG. 6 is a front view of a piston of the invention.
FIG. 7a is a Jante plot of simulated scavenging/charging flow into a cylinder of the invention with the piston of the invention at bottom dead center.
FIG. 7b is a Jante plot of the same cylinder as that of FIG. 7a but with a prior art piston having a sharp upper annular edge so positioned within the cylinder.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 and 2, the cylinder block 10 includes the cylinder head 11 forming the combustion chamber 12 and providing an aperture 13 for a spark plug. Two charge input passages 15 and 16, a boost passage 17 and an exhaust port 14 are cast into the inner cylinder wall 18.
Referring to FIGS. 2 and 4, the input passages 15 and 16 are open their entire length through the cylinder wall 18 so that they comprise open channels in the cylinder wall. The side walls 20 and 21 of each input passage are substantially parallel to each other and to a vertical plane forming an angle of 58° with a diameter of the cylinder which bisects the exhaust port 14, and are located radially so that their respective longitudinal bisecting planes intersect in an area substantially equidistant from the center of the cylinder and the center of the open side of the boost passage 17.
Referring to FIGS. 4 and 5, the top edge 30 of each charge input passage i.e. the line along which the top of the passage intersects the cylinder wall, slopes circumferentially upwardly as it progresses away from the exhaust port 14 at an angle of 10° to a lateral plane perpendicular to the longitudinal axis of the cylinder. The outer wall 31 of each input passage intersects the cylinder wall 18 at angles progressing from 10° upwardly from said lateral plane at its corner 32 most remote from the exhaust port 14, to 30° at its corner 33 nearest the exhaust port. This angulation and curvature result from insertion of a core having a constant radius at its upper extremity into the wall of the cylinder. This shape of the core facilitates die casting of the cylinder block. All of the walls of the input and boost passages are tapered to facilitate withdrawal of cores used in the casting of the cylinder block 10.
Referring to FIGS. 2, 3 and 4, the boost passage 17 is located diametrically across from the exhaust port 14, with side walls 40 and 41 generally parallel to each other and to a vertical plane bisecting the cylinder 10 and the boost passage 17. The top edge 42 of the boost passage 17 falls on a circumference 39 of the cylinder 10, and the outer wall 43 of the passage 17 intersects a lateral plane through that circumference at a constant angle of approximately 60°.
The top edge 42 of the boost passage 17 and the top edges 30 of the input passages are in general alignment with the circumference of the cylinder bisecting the exhaust port 14, except for the 10° slope of the edges 30. Both the input and boost passages extend fully into the crankcase section 49 of the engine where the input fuel-air charge is compressed in the usual manner of operation of a two-cycle engine.
Referring to FIG. 6, the piston 50 of the invention may have annular grooves 51 for piston rings of the usual type which ride in fixed position therein. In the illustrated embodiment, the top face 52 of the piston is domed slightly to conform to combustion chamber design; however, such doming is not required to realize the advantages of the invention.
One particularly novel aspect of the invention is rounding of the piston side wall 53 into the piston face 52. The rounding need not be of a particular radius but should smoothly join the side wall 53 and the face 52 with a generous curve tongent to both surfaces 52 and 53 at its points of intersection therewith. In one configuration of the preferred embodiment, a piston of 1.55 in. diameter very successfully performed with such curvature commencing at the top edge 54 of the upper ring groove 51 and extending upwardly through a vertical use of approximately 0.110 in. where it joined the slightly domed face 52 of the piston. Although the inventor has not run studies to determine if the exact nature of this curvature can be correlated with the curvature of the outer walls 31 of the input passages to determine an optimum configuration, it is possible that such a relationship may be determined. It is speculated that even a simple beveling of the piston edge would show some improvement in the flow characteristic of the cylinder, but not so great as that achieved with the rounding described above.
Note that in applying known art to the design of an engine incorporating the invention, i.e. decision on input and exhaust port spacing to provide desired performance over a selected range of rpm, the timing edge of the piston is that point where the curved top edge of the piston breaks away from the cylinder wall 18 and not the highest lateral projection of the piston.
FIGS. 7a and 7b are flow diagrams which illustrate in feet-per-second the velocities of incoming charge of various points within a selected plane within the above described cylinder. This method of evaluating flow is described in paper no. -680468 authored by Alfred Jante and published by the Society of Automotive Engineers in May 1968, and consists essentially of indexing an array of pressure sensing tubes across the cylinder while a constant pressure drop is maintained across the cylinder. Efficiency is indicated not only by the shape of the pattern and the flow velocities achieved, but also by the energy required to drive the fan to maintain a selected pressure drop (12 inches H 2 O in this instance) through the cylinder. The energy required to maintain this 12 inches H 2 O drop through the cylinder in the drawings is indicated by power input to the fan; e.g. ampere flow at constant voltage, as indicated at the bottom of FIGS. 7a and 7b.
The figures compare the performance of a prior art piston with a sharp annular edge, FIG. 7b, with the performance of a piston of the invention, FIG. 7a when within the same cylinder described herein. In both instances the piston was at bottom dead center. A comparison of these two figures show that when the sharp annular edge of the piston is changed to a curved surface as taught herein, two things change:
1. The incoming charge moves in a more even front across the cylinder (a pattern found by experience and acknowledged in the art to be most effective), and
2. More energy is required to maintain the 12 inches H 2 O pressure drop across the cylinder with the curved edge piston, indicating less flow resistance with the improved piston to the incoming charge.
Both changes indicate an increase in scavenging efficiency.
The structure taught herein is adaptable to a die cast cylinder block of a hypereutectic silicon aluminum base alloy wherein the cylinder surface is treated as described in U.S. Pat. No. Re 27,081 assigned to Reynolds Metals Company, or a chromium plated aluminum cylinder, in either case to be used in conjunction with a compatible piston material.
It is significant to note that the pressure pattern of my improved cylinder, illustrated in FIG. 7a, compares very favorably with patterns of engines having input passages curving through the cylinder block, yet is achieved with a more simplified and inexpensive structure.
While the principles of the invention have been described in connection with the above specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention.
|
The invention is an improved piston and cylinder arrangement for a loop charged two-stroke engine wherein all input passages are open channels in the cylinder wall and the top annular edge of the piston is rounded. The rounded edge on the piston cooperates with the described scavenging and input passages to reduce drag and, cause the incoming charge to flow more horizontally over the piston head; thereby improving scavenging and volumetric efficiency.
| 5
|
FIELD OF THE INVENTION
This invention relates to a magnetic recording medium having improved stability with passage of time, still durability and outputs.
BACKGROUND OF THE INVENTION
Magnetic recording media comprising a non-magnetic support having thereon a magnetic layer containing ferromagnetic particles such as ferromagnetic iron oxide or ferromagnetic alloy particles dispersed in a binder are mainly used as magnetic recording media such as an audio tape, a video tape, a tape for computers or a magnetic discs.
With recent developments in the field of this technology, higher density recording and higher efficiencies have been required for magnetic recording media. Toward this end, research has particularly focused on the binder used in the magnetic layer of a magnetic recording medium. Binders having good wear resistance and weather resistance have been developed, and it has been suggested to use, for example, polycarbonate polyurethanes used in combination with nitrocellulose and copolymer resins of vinyl chloride and vinylacetate as described in JP-A-58-60430, JP-A-60-13324, JP-A-61-9830 and U.S. Pat. No. 4,761,338. (The term "JP-A" as used herein means an "unexamined published Japanese patent application"). Also, the use of vinyl chloride and vinyl chloride resins containing a polar group has been suggested, which are used in combination with polyurethane as described in JP-A-61-253627. Lubricating agents have been studied to improve still durability, and alkali salts of a polyalkyleneoxide alkylphosphate (described in JP-A-50-40103) and lecithin (described in JP-B-52-3348) have been suggested. (The term "JP-B" as used herein means an "examined Japanese patent publication").
However, when these lubricating agents are used in the binder of a magnetic recording medium, only some of the characteristics of the medium can be improved, and further, these characteristics are merely partially improved. Moreover, use of these lubricating agents has not brought about improvement in all of the following respects: stability with the passage of time (adhesive property), still durability, output, gloss, and squareness ratio.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a magnetic recording medium having improved efficiencies in all of the above-mentioned respects.
Other objects and effects of the present invention will be apparent from the following description.
The above objects of the present invention have been attained by a magnetic recording medium comprising a non-magnetic support having thereon a magnetic layer comprising a binder and ferromagnetic particles dispersed therein, wherein the binder comprises (a) a vinyl chloride resin, (b) a phenoxy resin, (c) a polycarbonate polyurethane resin and (d) a polyisocyanate; and the magnetic layer further comprises at least one lubricating agent selected from the group consisting of polyalkylnenoxide alkylphosphate, an alkali salt thereof, and lecithin.
In accordance with this invention, hydrolysis characteristics and stability with the passage of time become excellent, and the dispersibility of the ferromagnetic particles, the squareness ratio and output can be greatly improved.
BRIEF DESCRIPTION OF DRAWINGS
The sole figure of the drawing schematically shows an apparatus for measuring adhesive property (adhesive strength) used in the Examples of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The vinyl chloride resin (a) referred to in this invention may be a copolymer of vinyl chloride and a copolymerizable monomer such as vinyl acetate, vinylidene chloride, acrylonitrile, styrene, or an acrylic acid ester. The vinyl chloride resin is preferably bonded with an epoxy group and an SO 3 M group wherein M is Li, Na, or K, most preferably Na. The vinyl chloride resin preferably has a number average molecular weight of from 15,000 to 60,000, and more preferably from 20,000 to 55,000. The vinyl chloride resin preferably contains a vinyl chloride content in an amount of from 80 to 90 wt % and preferably contains a copolymerizable monomer in an amount of from 10 to 20 wt %. The --SO 3 M group is preferably present in the vinyl chloride resin in an amount of from 0.1 to 2.0 wt %, more preferably from 0.3 to 1.5 wt %, and the epoxy group is preferably present in the vinyl chloride resin in an amount of from 0.2 to 2.7 wt %, more preferably from 0.7 to 2.2 wt %.
A phenoxy resin (b) which can be used in the present invention may be a resin produced from bisphenol A and epichlorohydrin preferably having a molecular weight of from 14,000 to 57,000 represented by the following formula: ##STR1## wherein n is from 50 to 200.
Specific examples of the phenoxy resin include those commercially available under the trade name of "BAKELITE Phenoxy Resin PKHH" produced by Union Carbide Co., Ltd., or the trade name "DER-686" produced by Dow Chemical Co., Ltd.
Examples of the polycarbonate polyurethane (c) which can be used in this invention include the above-mentioned polycarbonate polyester polyurethanes which are described in JP-A-58-60430 and the above-mentioned polycarbonate polyurethanes which are described in JP-A-60-13324 and U.S. Pat. No. 4,761,338. The polycarbonate polyurethane of the present invention is present in an amount of from 20 to 70 wt % based on the total weight of the binder.
The above-mentioned polycarbonate polyester polyurethane preferably is a polyurethane comprised of a polyol, a polyisocyanate and, if necessary, a chain extending agent. The polyol preferably is a polycarbonate polyol or a polyester polyol comprised of 1,10-decanedicarboxylic acid and polycarbonate polyol. The polycarbonate polyol can be obtained by condensing polyhydric alcohol with phosgen, chloroformic acid ester, dialkylcarbonate or diallylcarbonate.
Examples of the above-described polyhydric alcohol include 1,10-decanediol, 1,6-hexanediol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol and 1,5-pentanediol.
Examples of the polyisocyanate, which is to be reacted with the above-described polyol includes tolylene diisocyanate, 1,5-diphenylmethane diisocyanate, xylene diisocyanate, 1,5-naphthylene diisocyanate, hexamethylene diisocyanate, o-tolylene diisocyanate and the adduct product of these isocyanates with active hydrogen compounds.
Examples of the chain extending agent which can be used, if necessary, in the above-mentioned polyurethane include the above-described polyhydric alcohols, aliphatic polyamines, alicyclic polyamines and aromatic polyamines.
The above-mentioned polycarbonate polyurethanes which can be used in this invention can be obtained by a urethanated reaction of a polycarbonate polyol and a polyhydric isocyanate. The polycarbonate polyol and the polyhydric isocyanate used herein may be those described for the polycarbonate polyester polyurethane.
Other polyhydric alcohols and conventional chain extending agents may be used in combination with the above-mentioned urethanated reactions.
The polycarbonate polyurethane used in this invention can be prepared by heating the above-described polyol and polyhydric isocyanate in a nitrogen atmosphere, in the presence of, if necessary, catalysts, amide solvents, sulfooxide solvents, cyclic ether solvents, ketone solvents and/or glycol ether solvents at from 60° C. to 100° C. for several hours to prepare a prepolymer, and then continuously heating the prepolymer at from 60° C. to 100° C. until a polymer is formed.
In this invention, the above-described three components ((a), (b), and (c)) are used as the main components for a binder and polyisocyanate (d) is used as a hardening agent. The term "binder" used herein means the whole of the components (a), (b), (c) and (d).
As the polyisocyanate (d) used in this invention, any of polyisocyanates used in this field of art as a hardening agent of binders.
The compounding proportions of the above-mentioned three components of the binder are as follows. The chloride resin is preferably present in an amount of from 15 to 65 wt %, more preferably from 20 to 55 wt %, the phenoxy resin is preferably present in an amount of from 10 to 60 wt %, more preferably from 15 to 50 wt %, and the polycarbonate polyurethane resin is preferably present in an amount of from 25 to 75 wt %, more preferably from 30 to 70 wt %, based on the total weight of the three components (a), (b) and (c) of the present invention. The polyisocyanate is preferably present in an amount of from 5 to 30 parts by weight based on 100 parts by weight of the three components (a), (b), and (c) of the present invention. The total weight of the binder is preferably in an amount of from 20 to 70 parts by weight based on 100 parts by weight of ferromagnetic particles in the magnetic layer.
Still durability, squareness ratio, gloss and output are deteriorated when the vinyl chloride resin (a) is not used in a magnetic recording medium. Still durability and output are deteriorated when the phenoxy resin (b) is not used. Still durability is greatly deteriorated when the polycarbonate polyurethane resin (c) is not used, and still durability and output are both deteriorated when the polyisocyanate (d) is not used. When a vinyl chloride resin (a), a phenoxy resin (b), a polycarbonate polyurethane (c), and a polisocyanate (d) are used simultaneously with the lubricating agent a magnetic recording medium can be obtained which exhibits excellent properties in all of the following respects: still durability, adhesive strength, squarenes ratio, gloss and output.
As a lubricating agent, a polyalkyleneoxide alkylphosphate and an alkali salt thereof which is used in the magnetic layer of the present invention as a lubricating agent are disclosed in JP-A-50-40103. For example, the polyalkyleneoxide alkylphophate (and/or an alkali salt thereof) can be the phosphoric acid ester (or an alkali salt thereof) having the following formulae (I), (II) and (III). ##STR2##
In formulae (I), (II) and (III), R 1 , R 2 and R 3 , which may be the same or different, each is a monovalent group having from 6 to 28 carbon atoms, preferably an alkyl group, a substituted alkyl group substituted with an alkoxy group, a phenyl group or a phenoxy group; R 4 , R 5 and R 6 , which may be the same or different, each is a hydrogen atom, a methyl group or an ethyl group; M 1 and M 2 each is a hydrogen atom, a sodium atom, a potassium atom or N(R 7 ) q (R 8 ) 4-q , wherein R 7 and R 8 each is a hydrogen atom, a methyl group, an ethyl group, a hydroxyethyl group or a hydroxypropyl group and q is an integer of from 1 to 4; m, n and p, which may be the same or different, each is an integer of from 4 to 12.
In case when compounds having formulae (I), (II) and (III) are used in mixture, the weight mixing ratio of (I) and (II) ((I):(II)) is preferably from about 2:8 to about 8:2, and the weight mixing ratio ((I)+(II):(III)) is preferably from about 10:0.01 to about 10:5.
The alkali salt of a polyalkyleneoxide alkylphosphate can be prepared by reacting a polyalkyleneoxide alkylphosphate with an alkali such as sodium hydroxide, potassium hydroxide, ammonia, monoethanol amine, diethanol amine or triethanol amine.
Below are examples of compounds having formulae (I), (II) and (III), but the present invention is not to be construed as being limited thereto. ##STR3##
In this invention, lecithin may be used instead of or with the above described phosphate or the alkali salt thereof. Lecithin is disclosed in JP-B-52-33482.
In this invention, the above-described lubricating agent is present in an amount of preferably from 0.08 to 8 parts by weight, more preferably from 0.3 to 5 parts by weight, based on 100 parts by weight of the ferromagnetic particles in the magnetic layer.
Examples of the ferromagnetic particles which can be used in this invention include γ-Fe 2 O 3 , Co-containing γ-Fe 2 O 3 , Fe 3 O 4 , Co-containing Fe 3 O 4 , γ-FeOx (1.33 <x ≦1.50), Co-containing γ-FeOx (1.33 <x ≦1.5), CrO 2 , Ce-Ni-P alloy, Co-Ni-Fe alloy, Fe-Ni-Zn alloy, Ni-Co alloy, Co-Ni-Fe-Be alloy and hexagonal crystal plate like barium ferrite. These ferromagnetic particles preferably have an average particle size of from about 0.005 to 2 μm and the ratio of axis length/axis width preferably is from 1/1 to 50/1. The specific surface area thereof preferably is from 1 to 70 m 2 /g.
In this invention, additives such as dispersing agents, antistatic agents or the like can additionally be added into the magnetic layer. These additives are disclosed in JP-B-56-26890.
In this invention, the above described ferromagnetic particles, abrasive agents and binders, and if necessary, other additives are mixed and kneaded using organic solvents to prepare a magnetic coating composition which is then coated on a non-magnetic support and dried to form a magnetic layer.
Examples of solvents which can be used to prepare the magnetic coating composition include ketone solvents (e.g., acetone, methyl ethyl ketone, methyl isobutylketone, cyclohexanone, isophorone, tetrahydrofuran), alcohol solvents (e.g., methanol, ethanol, propanol, butanol, isobutyl alcohol, isopropyl alcohol, methyl hexanol), ester solvents (e.g., methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isopropyl acetate, ethyl lactate, glycol acetate, monoethyl ether), glycol ether solvents (e.g., ether, glycol dimethyl ether, glycol monomethyl ether, dioxane), aromatic hydrocarbon solvents (e.g., benzene, toluene, xylene, cresol, chlorobenzene, styrene), chlorinated hydrocarbon solvents (e.g., methylene chloride, ethylene chloride, carbon tetrachloride, chloroform, ethylene chlorohydrin, dichlorobenzene), N,N-dimethyl formamide, and hexane.
Materials for forming a non-magnetic support include polyester resins, polyolefin resins, cellulose derivatives, polycarbonate resins, polyimide resins and polyamide imide resins. Also depending upon the purposes of use, aluminum, copper, tin and zinc, non-magnetic metals containing the above metals, plastics vapor-deposited with metals such as aluminum, paper and paper coated or laminated with polyolefins can be used. The shape of the non-magnetic support is not particularly limited, and a sheet shape support is generally used. The non-magnetic support may have a film shape, a tape shape, a disk shape, a card shape or a drum shape.
When a sheet shape non-magnetic support is used, it has a thickness of generally from 5 to 50 μm.
A backing layer may be provided on the surface of the non-magnetic support which is opposite to the surface coated with the magnetic layer.
The magnetic layer thus provided on the non-magnetic support is generally provided with magnetic orientation to orientate the ferromagnetic particles contained in the magnetic layer, and then dried. Further, if necessary, the magnetic layer is provided with a calendering treatment as a surface treatment, and thereafter is cut to a desired shape.
This invention will be illustrated by the following Examples and Comparative Examples, but is not to be construed as being limited thereto. All parts are by weight unless otherwise indicated.
EXAMPLES AND COMPARATIVE EXAMPLES
Magnetic recording media Samples Nos. 1 to 25 were prepared by the following manner.
The magnetic coating composition having the following formulation was coated on a polyethylene terephthalate film having a thickness of 30 μm, dried and provided with a mirror treatment to obtain a magnetic layer having a thickness of 5 μm.
__________________________________________________________________________Co-containing γ-Fe.sub.2 O.sub.3 ' 100 parts(specific surface area S.sub.SET : 30 m.sup.2 /g)Vinyl chloride Kinds and amountsacetate compound shown in Table 1Phenoxy resin Amounts shown in Table 1("BAKELITE phenoxy resin PKHH"produced by Union Carbide Co., Ltd.)Urethane resin Amounts shown in Table 1Carbon black 10 parts(average particle diameter: 120 nm)γ-Al.sub.2 O.sub.3 1 part(average particle diameter: 0.38 μm)Lecithin (produced by Nisshin Amounts shownOil Co., Ltd.) in Table 1Phosphoric acid ester Amounts shown("GAFACRE-610" produced by GAF CO., LTD.) in Table 1Butyl stearate 1 partMethyl ethyl ketone 60 partsToluene 80 partsTetrahydrofuran 60 partsIsocyanate compound 7 parts__________________________________________________________________________
The polycarbonate polyurethane used in Sample Nos. 1 to 16 and 19 to 25 was prepared in accordance with the disclosure of Example 1 of JP-A-60-13324, and the polycarbonate polyester urethane used in Sample No. 17 was synthesized in the same manner as that in Example 1 as disclosed in JP-A-58-60430.
The polyester polyurethane used in Sample No. 18 was "C7209" produced by DAINIPPON INK AND CHEMICALS, INC.
The vinyl chloride resin "400×110A" was a product of Nippon Zeon Co., Ltd., and "TPR-TM" was a product of Nisshin Chemical Industries, Ltd.
The following tests were performed on the samples thus obtained, and the results are shown in Table 2.
Adhesive strength
As shown in the drawing of FIG. 1, using a microtablet molding device produced by Hitachi, Ltd., two sample tapes having surface areas of 3.18 cm 2 (1.27 cm ×1.85) cm were placed one on top of the other, with their magnetic layers face to face, sandwiched between two spacers (1 and 1') through glass plates (2 and 2') , and were pressed at a torque (3) of 60 kg/cm 2 . The magnetic layers were allowed to stand at the above condition at 50° C. for 5 hours, and thereafter both tapes were pulled in the direction parallel to their surfaces by a pulling device to measure the adhesive strength in units of kg/3.18 cm 2 .
When a binder of a magnetic recording medium becomes hydrolyzed and its molecular weight becomes lower (a phenomenon which occurs at high temperatures and high humidities), the low molecular weight substances exude when pressure is applied, and thus the surfaces of magnetic layers become adhesive, and the adhesive strength of such layers becomes higher. That is, the adhesive strength represents the adhesive characteristics and the degree of hydrolysis of the binder
Gloss on the surface of the magnetic layer
Gloss was measured in accordance with JIS Z8741 and is shown in Table 2 in terms of relative values when mirror wise gloss on the surface of glass having a refractive index of 1.567 at an angle of incidence of 45° is 100%.
Squareness ratio
The squareness ratio Br/Bm was measured at Hm of 2 KOe using an oscillating magnetic flux meter produced by Toei Kogyo Co., Ltd.
Still durability
Screen image signals of image signals 501RE were recorded and reproduced at a still mode. While the reproduced RF output level was being recorded with a recorder, the period of time for the signal level to decrease to half of the initial level was measured.
The thermo-treated samples (60° C. at 80% RH for 7 days) and unthermo-treated samples were tested to demonstrate the effects of the present regarding still durability and adhesive strength.
Output
The output was measured using a video tape recorder "V500D" produced by Toshiba Corporation equipped with a ferrite head. In Table 2, the output is shown in terms of relative values when Sample No. 10 had an output value of 0 dB.
In Table 2, Sample Nos. 1, 2, 6, 10, 12, 18 and 19 are comparative examples, and the others are examples of the present invention.
TABLE 1__________________________________________________________________________ Phenoxy Polyiso- Vinyl chloride resin resin Urethane resin cyanate LubricantSample No. (wt %) (wt %) (wt %) (part) (part)__________________________________________________________________________ 1 MPR-TM 0 70 Polycarbonate 30 7 Lecithin 3 Polyurethane 2 MPR-TM 0 30 Polycarbonate 70 7 Lecithin 3 Polyurethane 3 MPR-TM 15 60 Polycarbonate 25 7 Lecithin 3 Polyurethane 4 MPR-TM 15 10 Polycarbonate 75 7 Lecithin 3 Polyurethane 5 MPR-TM 15 40 Polycarbonate 45 7 Lecithin 3 Polyurethane 6 MPR-TM 40 0 Polycarbonate 60 7 Lecithin 3 Polyurethane 7 MPR-TM 40 10 Polycarbonate 50 7 Lecithin 3 Polyurethane 8 MPR-TM 40 25 Polycarbonate 35 7 Lecithin 3 Polyurethane 9 MPR-TM 40 35 Polycarbonate 25 7 Lecithin 3 Polyurethane10 MPR-TM 40 60 Polycarbonate 0 7 Lecithin 3 Polyurethane11 MPR-TM 65 10 Polycarbonate 25 7 Lecithin 3 Polyurethane12 MPR-TM 35 25 Polycarbonate 40 0 Lecithin 3 Polyurethane13 MPR-TM 35 25 Polycarbonate 40 5 Lecithin 3 Polyurethane14 MPR-TM 35 25 Polycarbonate 40 15 Lecithin 3 Polyurethane15 MPR-TM 35 25 Polycarbonate 40 30 Lecithin 3 Polyurethane16 400 × 110A 40 25 Polycarbonate 35 7 Lecithin 3 Polyurethane17 400 × 110A 40 25 Polycarbonate 35 7 Lecithin 3 polyester polyurethane18 400 × 110A 40 25 Polyester 35 7 Lecithin 3 Polyurethane19 MPR-TM 40 25 Polycarbonate 35 7 I-1 0 polyurethane20 MPR-TM 40 25 Polycarbonate 35 7 I-1 0.08 polyurethane21 MPR-TM 40 25 Polycarbonate 35 7 I-1 3 polyurethane22 MPR-TM 40 25 Polycarbonate 35 7 I-1 8 polyurethane23 MPR-TM 40 25 Polycarbonate 35 7 I-4 3 polyurethane24 MPR-TM 40 25 Polycarbonate 35 7 II-2 3 polyurethane25 MPR-TM 40 25 Polycarbonate 35 7 III-2 3 polyurethane__________________________________________________________________________
TABLE 2__________________________________________________________________________Adhesive strengthSample Non-thermo- Thermo- Still SquarenessNo. treated treated durability ratio Gloss Output__________________________________________________________________________ 1 0.23 0.22 28 0.74 18 -2.4 2 0.20 0.21 31 0.74 19 -2.3 3 0.19 0.21 >60 0.84 38 -0.1 4 0.21 0.22 >60 0.83 40 -0.1 5 0.20 0.20 >60 0.83 41 0 6 0.23 0.22 40 0.85 38 -0.1 7 0.22 0.24 >60 0.82 42 0 8 0.24 0.22 >60 0.82 46 0 9 0.22 0.23 >60 0.84 38 -0.110 0.21 0.21 10 0.83 43 011 0.23 0.23 45 0.83 41 012 0.24 0.22 5 0.83 40 -0.213 0.23 0.24 >60 0.84 38 -0.114 0.22 0.23 >60 0.82 39 -0.115 0.22 0.20 >60 0.84 42 016 0.23 0.21 >60 0.84 39 -0.117 0.23 0.25 >60 0.84 41 018 0.58 5.00 >60 0.82 38 -0.119 0.22 0.23 >60 0.75 8 -3.020 0.21 0.23 >60 0.82 35 -0.321 0.24 0.22 >60 0.84 39 022 0.23 0.24 >60 0.85 43 023 0.22 0.23 >60 0.83 39 -0.124 0.23 0.24 >60 0.84 40 -0.125 0.23 0.22 >60 0.83 41 -0.1__________________________________________________________________________
Thermo-treated samples were tested and compared with non-thermo-treated samples to demonstrate the effect of the present invention on stability with passage of time (adhesive strength).
As is clear from the above results, the present invention improves still durability of a magnetic recording medium remarkably but does not increase adhesive strength (i.e., stability with passage of time is excellent).
It is also understood from the above results that invention remarkably improves squareness ratio and gloss, and as a result thereof output is remarkably improved as well.
While the 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.
|
A magnetic recording medium comprising a nonmagnetic support having thereon a magnetic layer comprising a binder and ferromagnetic particles dispersed therein, wherein the binder comprises (a) a vinyl chloride resin, (b) a phenoxy resin, (c) a polycarbonate polyurethane resin and (d) a polyisocyanate; and said magnetic layer further comprises at least one lubricating agent selected from the group consisting of polyalkylnenoxide alkylphosphate, an alkali salt thereof, and lecithin.
| 8
|
FIELD OF THE INVENTION
The present invention relates to a release system for the inflatable packer elements which are used with a drill stem tester.
BACKGROUND OF THE INVENTION
In order to evaluate the oil and gas producing potential of geological formations, it is known to attach a formation testing tool to a drill stem and lower the same into an inclosed well bore. Packer elements, which are used to isolate the zone which is to be tested for its producing potential, are lowered into the bore hole in a deflated state. When the formation testing tool attached to the drill stem is at the appropriate depth, the packers inflate on either side of the zone. After the test has been completed, the packers are deflated in order to permit the drill stem to be moved again.
Various inflatable packer systems have been proposed for use with drill stem testers. Some systems make use of the drill pipe rotation to actuate a piston pump which displaces fluid into the packer elements; in other systems, the drill pipe reciprocation actuates the piston pump to displace the fluid into the packer elements. The set-down movement of the drill pipe can also be used to move a piston to displace fluid into the packer elements. In still other systems, the drill pipe rotation or weight set-down opens a valve allowing compressed gas from a tank to move a piston so as to displace fluid into the packer elements.
Canadian Pat. No. 1,142,848 discloses one inflatable packer system which has been used in drill stem testing in the Canadian west. The system disclosed in the patent uses a rotary pump, actuated by rotating the drill stem, to pump drilling mud to the packer elements. A check relief valve is provided to guard against packer deflation in case of a loss of pump pressure, and against over-inflation and rupture of the packer elements. The valve subassembly incorporates a shifting sleeve which is pumped down upon initial operation of the pump. Pumping down the shifting sleeve opens a passage between the pump outlet and the packer elements so as to permit inflation of the packer elements.
When the packer system is inflated, weight is set-down on the drill stem to collapse the inner portion of the valve with respect to the outer portion of the valve. Initial movement of the inner portion of the valve isolates and seals off the packer elements; further movement vents inflation fluid from the pump to the well. Packer deflation is accomplished by lifting the drill stem to stretch the valve to its original elongated position. Initial lifting of the inner portion of the valve opens the vent to the well bore from the isolated zone to equalize the pressure in the zone with that in the well bore; further lifting causes the shifting sleeve to be picked up and opens a passage to the well bore from the interior of the packer elements, for deflation thereof.
In the operation of this prior art system, a mechanical latch must be released by pressure from the rotary pump in order to inflate the packer elements. This is a potential area of difficulty, where wearing or jamming may occur. Furthermore, in order to open a path for pressure fluid between the formation and the surfaee, the formation flow ports in the tool must move to open up relief ports between the pump and the release mechanism; the port is opened to the well bore after a short movement of the tool, so as to relieve any excess pressure, and then the port is resealed before the main valve opens. This design requires that the pressure between the pump and the release system be relieved, thus necessitating additional features. Finally, to release the packer elements, the ports must be aligned; again, the need to perform a mechanical latching operation presents an area vulnerable to wear and failure.
SUMMARY OF THE INVENTION
The present invention relates to a release system for use with inflatable packer elements forming part of a drill stem tester, comprising a hydraulically operated piston and upper adaptor assembly to inflate and deflate the packer elements. The initial flow of inflation fluid into the assembly causes the piston to move upward, aligning conduit means in the piston with conduit means in the upper adaptor. A valve permits passage of the inflation fluid to the packer elements through the conduit means in the piston when the piston is in alignment with the conduit means in the upper adaptor. An increase in the pressure of the inflation fluid causes a second valve in the upper adaptor to open, thereby allowing the piston to move to uncover the conduit means in the piston to the well bore, so that the pressure fluid from the packer elements can flow through such conduit means to the well bore.
More particularly, this invention relates to a device adapted to be positioned in a drill string to control the supply of inflating fluid to and from an inflatable packer. The device is
The first element is attached to the upper portion of the drill string, and has first conduit means which convey pressure fluid from the upper portion of the drill string. (The pressure fluid is usually generated by a pump in the drill string just a short distance above the release device.)
The second element is atached to the lower portion of the drill string and has second conduit means to convey pressure fluid to and from inflatable packer elements associated with the lower portion of the drill string.
A piston is provided which is moveable between two positions. In a first position, the first and second conduits are in register with one another, so that pressure fluid can flow from the upper part of the drill string through the first and second conduit means to inflate (or keep inflated) the packer elements. In a second position, the first and second conduits are out of register, and the second conduit is open to the well bore so that fluid will flow from the packer elements to the well bore, causing them to deflate.
In the preferred embodiment, the piston is caused to move towards the first position when the fluid in the first conduit is under pressure. When the fluid in the first conduit drops to the ambient pressure of the well bore, the piston moves to the second position. However, it is possible to cause piston movement in other ways, as by vertically moving the drill string from the ground surface. In the preferred embodiment as well, the first element defines the cylinder in which the piston travels, and the piston is integral with the second element. However, it will be evident to one skilled in the art that it is possible to have the second element define the cylinder, with the piston being integral with the first element. Such variations are within the scope of the invention, provided the piston moves from a first position where the first and second conduit means are in register to a second position where the second conduit means is open to the well bore.
Suitably, a first valve is provided to close off the first conduit means when it is not in register with the second conduit means. The valve is designed to open when the two conduit means are in register. This valve is not essential to the operation of the apparatus, but it is desirable to provide it, as otherwise the pressure of fluid in the first conduit may abrade the O-ring seals between the piston and the cylinder when the first and second conducts approach their in-register position. It is also convenient to have a second valve as an overpressure valve to reduce pressure in the first conduit means so that the piston can return to the second position. This permits the operator to actuate movement of the piston to the second position very simply, merely be causing excess pressure in the first conduit means, so as to cause the overpressure valve to open.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a drill stem testing system with which the release of the present invention can be used.
FIG. 2 depicts a longitudinal section through the release device shown in FIG. 1, the piston being in the position associated with fully deflated packers.
FIG. 3 depicts a longitudinal section through the release device shown in FIG. 1, the piston being in the position it assumes when the packer is inflated.
DETAILED DESCRIPTION
A preferred embodiment of the invention will now be described in detail in conjunction with the attached drawings.
The drill stem tester shown generally as 1 in FIG. 1 is inserted into bore hole 3. Drill string tester 1 has upper inflate packer 7 and lower inflate packer 8 disposed about zone 5, the zone which is being tested. Recorder carrier 9 and spacer 10 are located between upper inflate packer 7 and lower inflate packer 8; recorder carrier 9 is used to carry the instruments which record the data from the tests carried out when fluid is forced into the formation through formation flow ports 11. Release device 13 is fitted above upper inflate packer 7 and is in fluid connection with upper inflate packer 7; release device 13 is also in fluid connection with lower inflate packer 8, by means of annular conduit 12 in space 10 around conduit 16. Conduit 16 is the central bore through which the formation flows to the surface during the testing procedure. Located above release system 13 are suction screen 18 and inflate pump 19. Drag spring 20, below lower inflate packer 8, engages the wall of well bore 3 and prevents the system from turning as drill stem tester 1 is rotated.
Release system 13 is depicted in detail in FIG. 2. Release system 13 includes upper adaptor 30, flow mandrel 40, cylinder 50, piston 60, and lower adaptor 100. The upper adaptor, flow mandrel and cylinder together form the first element, or upper element, of the invention in this embodiment. Lower adapter 100 is the second element, and is integral with piston 60.
Internally threaded portion 35 of upper adaptor 30 is fitted to externally threaded portion 41 of flow mandrel 40. Upper adaptor 30 has formed therein passages 33 in fluid connection with passages 42 formed in adjacent flow mandrel 40. In the embodiment shown there are four passages 33 spaced around the diameter of the adaptor 30 and four connecting passages 42 in the flow mandrel but the number of such passages is not critical. Conventional O-rings 70 between upper adaptor 30 and flow mandrel 40 provide a seal therebetween. Upper adaptor 30 is fitted to the lower portion of suction screen 18 of the upper part of drill stem tester 1 by means of internally threaded portion 34. Conventional O-rings 78 provide a seal between flow mandrel 40 and an unthreaded lower portion of section screen 18.
Cylinder 50 has internally threaded portion 51 fitted to externally threaded portion 32 of upper adaptor 30. Piston 60 lies between flow mandrel 4, and cylinder 50; conventional O-rings 71 provide a seal between piston 60 and cylinder 50, and conventional O-rings 72 and 73 provide a seal between piston 60 and flow mandrel 40.
Piston 60 is capable of longitudinal movement in cavity 61 which extends between flow mandrel 40 and cylinder 50, cavity 61 having venting aperture 53 open to the well bore to relieve pressure build-up from such movement. Pin 52 protrudes from cylinder 50 and slides in a slot 66 provided in piston 60 as the piston moves so that piston 60 is not free to rotate relative to cylinder 50. Piston 60 has formed therein passage 62, passage 62 being in fluid connection with annular cavity 63 between piston 60 and flow mandrel 40 and in fluid connection with annular passage 64 between piston 60 and cylinder 50. Cavity 63 is in fluid connection with passages 42 formed in flow mandrel 40 and thence with passages 33. Passages 33, 42, 63, 62, and 64 together define, in his embodiment, the "first conduit means" of the invention.
Piston 60 narrows at the lower potion thereof, wherein cylinder 50 has formed recesses containing valve assemblies 80 and 90. Piston 60 has formd therein, below valve assemblies 80 and 90, passages 67 in fluid connection with passage 68 which extend the remainder of the longitudinal length of piston 60.
Externally threaded lower portion 69 of piston 60 is fitted into internally threaded portion 101 of lower adaptor 100. Lower adaptor 100 has formed therein passages 102, passages 102 being in fluid connection with passage 68. In the embodiment shown there are four such passages, spaced around the diameter of the lower adaptor, but the number of such passages is not critical. These passages together with passages 67 and 68 form the "second conduit means" of the invention in this emodiment. Lower adaptor 100 is fitted to upper inflate pacer 7 of the lower part of drill stem tester 1 by means of externally threaded portion 103. Conventional O-rings 674 and 75 between piston 60 and lower adaptor 100 provide a seal therebetween.
Valve assembly 80, located in a recess between cylinder 50 and piston 60, is a pump-up valve for inflating packer elements 7 and 8. Valve assembly 80 is in contact with annular passage 64 at the upper end thereof and discharges into annular space 55. Conventional O-rings 76 and 77 form a seal between piston 60 and cylinder 50, and O-rings surroundng the valve prevent fluid passage from passage 64 to space 55, so that valve assembly 80 provides the only means whereby fluid can pass through passages 64 and continue to flow downward toward packer elements 7 and 8. Valve assembly 80 has pin 81 at the lower end thereof. Pin 81 is a contact pin, such that contact of pin 81 by upper parl 104 of lower adaptor 10 causes valve assembly 80 to pen, thereby permitting the flow of fluid from passages 64 through valve assembly 80 to annular space 55 to aperture 57 and annular passage 59, and thence through passages 67, 68 and 102 to packer elements 7 and 8.
Valve assembly 90, located in recess 56 between piston 60 and cylinder 50, is a relief valve for use in deflating packer elements 7 and 8. Valve assembly 90 is set at a certain pressure level, such that excess pressure above the preset level causes valve assembly 90 to open and to permit fluid from annular passage 64 to flow through valve outlet 91 to well bore 3. O-rings surrounding the valve prevent leakage around it when the valve is closed. An example of a commercially available valve assembly suitable for use as valve assembly 90 is the "Nupro R3A series," (trade mark) externally adjusted relief valve, manufactured by the Nupro company
In order to fill packer elements 7 and 8, inflate pump 19 draws the drilling mud which is the pressure fluid from well bore 3 through suction screen 18 to release system 13. The fluid enters passages 33 of upper cylinder 30 and passes therethrough to passages 42 of flow mandrel 40. The fluid continues to flow through passages 42 and fills cavity 63 between flow mandrel 40 and piston 60. The fluid then flows through passage 62 in piston 60 to annular passage 64 between cylinder 50 and piston 60.
The increasing pressure of the pressure fluid causes piston 60 to move in a longitudinally upward direction with respect to cylinder 50. Being screwed to piston 60, lower adaptor 100 also moves upward. When upper part 104 of lower adaptor 100 makes contact with pin 81 of valve assembly 80, pin 81 causes valve assembly 80 to open, thereby permitting the pressure fluid to flow from passages 64 to annular recess 55 and thence through outlet aperture 57 to passages 67, which are in fluid connection with passages 68 in piston 60 and passages 102 in lower adaptor 100 as shown in FIG. 3. The pressure fluid is thus able to flow through passages 102 to packer element 7, and to packer element 8 by means of annular conduit 12. Packer elements 7 and 8 are inflated by the accumulation of the pressure fluid. After packer elements 7 and 8 have been inflated, the test of zone 5 can be conducted in conventional manner.
After the test of zone 5 has been completed, the fluid in packer elements 7 and 8 must be released to enable packer elements 7 and 8 to deflate and thereby permit drill stem tester 1 to be moved. An upward pull is exerted from ground level on the drill stem. This causes upper adaptor 30 and parts 40 and 50 (which are rigidly connected to it) to move upwardly. Piston 60 does not move upwardly, due to the weight of the lower drill string and because the inflated packers are engaging the well bore. Therefore, the pressure of the fluid in cavity 63 between the piston and mandrel 40 increases. This increase in pressure is transmitted to the fluid in the remainder of the first conduct means, including annular passage 64. When the fluid pressure in passage 64 exceeds the set pressure of relief valve 90, valve 90 opens and the fluid flows through outlet 91 to well bore 3. After the fluid is released, piston 60 is free to move in a downward direction and does so as the drill string is pulled upwardly from ground level. Piston 60 continues to move downward until shoulder 65 thereof engages the shoulder 58 on cylinder 50. As piston 60 moves downward, passages 67 are no longer sealed from the well bore by O-rings 77 in the lower portion of cylinder 50; passages 102 through lower adaptor 100 and 68 through piston 60 therefore come into connection with well bore 3. This permits fluid from packer elements 7 and 8 to flow through passages 102, 68 and 67 to well bore 3. Escape of pressure fluid from packer elements 7 and 8 causes packer elements 7 and 8 to deflate, thereby enabling drill stem tester 1 to be removed from the well.
It is seen that the use of the release device herewith described does not require that the release system be connected mechanically to the pump, thus obviating the necessity for connecting or latching operations. Reliability is increased because the entire release operation is performed hydraulically, rather than partially or entirely by mechanical means. The entire system design is simplified, and this minimizes the possibility of component failure.
The foregoing has shown and described a particular embodiment of the invention, and variations thereof will be obvious to one skilled in the art. Accordingly, the embodiment is to be taken as illustrative rather than limitative, and the true scope of the invention is as set out in the appended claims.
|
Apparatus for controlling the flow of inflation fluid to an inflatable packer elements forming part of a drill stem tester, comprises a hydraulically operated piston and adaptor assembly to inflate and deflate the packer elements. The initial flow of inflation fluid into the assembly causes the piston to move upward, aligning a conduit in the piston with a conduit in the adaptor. A valve permits passage of the inflation fluid to the packer elements through the conduit in the piston when the conduit in the piston are in alignment with the conduit in the adaptor. An increase in the pressure of the inflation fluid surrounding the piston causes a second valve in the adaptor to open, thereby allowing the piston to move downward and the pressure fluid from the packer elements to flow to the well bore.
| 4
|
FIELD OF THE INVENTION
The present invention relates generally to storage containers, and more particularly to a storage container having a unique divider system and hinge configuration.
BACKGROUND
Storage containers exist in many varieties and may be used to store, organize and transport various items such as fasteners, tool bits and other accessories.
The storage container of the present invention is designed such that it may simplify the manufacturing of a storage container. Plastic storage containers can be typically manufactured fairly inexpensively, but often at the expense of being less rigid and providing less flexibility in adapting the storage container to store items of various sizes and shapes. When used to store tool bits, fasteners or accessories on a job site, a storage case must be built to be strong and durable so that if it is dropped, it does not break open and spill its contents. Storage containers often include a base portion and a cover portion hingedly connected to the base portion.
Conventionally, molding a plastic cover with an integrated hinge portion would involve a first step of positioning a metal rod in the section of the die to consist of the hinge portion and a second step of removing the metal rod after the cover is molded to reveal the resultant continuous passage for the pin of the hinge. The base portion of the case would be molded in a similar fashion with the resultant hinge portion able to interfit with the hinge portion of the cover such that a pin may be inserted therethrough creating a hinged container. It would be desirable to mold the cover and base including the hinge side of a storage container each in a single step.
SUMMARY OF THE INVENTION
The storage container in accordance with this invention provides an improved storage container and method to mold the same. The molding process incorporates strategically placed bores and apertures in a die. The bores and apertures are formed at right angles such that they cooperate to form a continuous passage able to accept a pin to form a hinge. A base, cover and two internal transparent lids are each constructed with the unique hinge configuration.
The container includes internal lateral wall sections on the cover and base having tabs extending therefrom. Removable spacers slidably interfit with the tabs to allow the user to customize the interior of the container.
The transparent lids of the internal compartment have slidable latches for engagement with inner slots of the cover and base. The latches are aligned such that both lids must be secured in the locked position prior to properly closing the storage container.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a perspective view of an assembled storage container shown in an open position;
FIG. 2A is a plan view of the outer surface of the cover constructed in accordance to the teachings of the preferred embodiment;
FIG. 2B is a plan view of the inner surface of the cover;
FIG. 2C is a top view of the cover;
FIG. 2D is a side view of the cover;
FIG. 2E is a bottom view of the cover;
FIG. 3A is a plan view of the outer surface of the base of the storage container constructed in accordance to the teachings of the preferred embodiment;
FIG. 3B is a plan view of the inner surface of the base;
FIG. 3C is a top view of the base;
FIG. 3D is a side view of the base;
FIG. 3E is a bottom view of the base;
FIG. 4A is a plan view of the first side of a cover plate according to the principles of the present invention;
FIG. 4B is a plan view of the second side of the cover plate;
FIG. 4C is a rear view of the cover plate;
FIG. 4D is a side view of the cover plate;
FIG. 5 is a perspective view of a spacer according to the principles of the present invention;
FIG. 6 is a perspective view of a cover plate latch according to the principles of the present invention;
FIG. 7 is a perspective view of the storage case latch member according to the principles of the present invention;
FIG. 8A is a plan view of the inner surfaces of the cover and base to illustrate the alignment of the tab portions;
FIG. 8B is a plan view of the first and second cover plates, the second cover plate identical to the first but rotated and flipped 180 degrees from the first cover plate;
FIG. 9 is a plan view of an assembled storage container shown in an open position to illustrate the outer surface of the cover and base;
FIG. 10A is an exploded perspective view of a mold used to construct a cover portion of the storage container according to the preferred method of the present invention;
FIG. 10B is an exploded perspective view of the bottom and side mold members used to construct the cover portion according to the preferred method of the present invention; and
FIG. 11 is an enlarged perspective view of the area 11 of FIG. 10 illustrating the alignment of the hinge forming pegs.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1 , the storage container 10 of the present invention is shown. The storage container 10 includes a base 12 and a cover 14 hingedly attached to the base 12 . A pair of transparent cover plates 16 , 18 are provided for selectively enclosing the storage area defined by the base 12 and cover 14 , respectively.
As shown in FIGS. 2A–2E , the cover 14 includes a cover surface 20 , an inner surface 22 , a top wall 24 , side walls 26 , 28 and a bottom wall 30 . Similarly, referencing now FIGS. 3A–3E , the base 12 includes a bottom surface 32 , an inner surface 34 , a top wall 36 , side walls 38 , 40 and bottom wall 42 . The storage container 10 includes removable spacers 52 ( FIG. 1 and FIG. 5 ) that may be selectably positioned within the storage container to customize the interior space. Slidable latches 70 , 70 ′ releasably secure cover plates 16 and 18 to the base 12 and cover 14 , respectively. Latch 80 releasably secures cover 14 to the base 12 .
With continued reference to FIGS. 2A–2E , the cover 14 will now be described in greater detail. Cover surface 20 is contoured to include upwardly extending portions 44 . The inner surface 22 includes parallel dividers 46 , 56 extending between side walls 26 , 28 . Parallel dividers 46 , 56 and bottom wall 30 include tabs 48 extending therefrom. Tabs 48 are configured to engage fingers 50 of removable spacers 52 (best shown in FIG. 5 ). Opposing tabs 48 a , 48 b ( FIG. 2B ), are laterally offset a predetermined distance such that a readily available piece of material may be substituted for a spacer 52 , in the event a spacer is misplaced. The predetermined distance is configured to be a distance common to readily available scrap pieces of material such as, but not limited to, ⅛ inch plywood. Bottom surface 30 includes integrated hinge member 76 . A slot 58 is configured to accept a finger 98 on latch 70 ′ (best shown in FIGS. 1 and 6 ) of cover plate 18 .
Turning now to FIGS. 3A–3E , the base 12 will now be described in greater detail. The inner surface 34 of the base 12 is configured much the same as the cover 14 . Base surface 32 includes recessed portions 54 . The recessed portions 54 are coordinated to interfit with the upwardly extending portions 44 of cover 14 such that a series of cases 10 may be securely stacked. The inner surface 34 includes parallel dividers 64 , 66 extending between side walls 38 , 40 . Parallel dividers 64 , 66 and bottom wall 42 include tabs 68 extending therefrom. Tabs 68 are configured to engage tabs 50 of removable spacers 52 (best shown in FIGS. 1 and 5 ). Opposing tabs 68 a , 68 b are laterally offset a predetermined distance such that a scrap piece of material may be substituted for a spacer 52 as described above. Base 12 includes integrated hinge member 86 . A slot 120 is configured to accept finger 98 on latch 70 (best shown in FIGS. 1 and 6 ) of cover plate 16 .
The storage container 10 of the present invention allows the apertures of the hinge portion to be formed without the need of a metal rod for forming the apertures. The configuration of the cover 14 and the base 12 illustrated in FIGS. 2A–3E include hinge portions 76 and 86 , respectively. The hinge member 76 of cover 14 includes tab portions 78 which are formed from a die configuration that creates cavity sections 82 ( FIG. 2B ) in a direction perpendicular to the plane of cover 14 . Additionally, the die allows cavity sections 84 (viewed from FIG. 2E ) to be formed in a direction parallel to the plane of cover 14 and in a location between cavity sections 82 . The insert portions of the die are strategically located such that cavity sections 82 and 84 cooperate to form a continuous passage 88 ( FIGS. 2B and 2D ) which is created without the need for additional steps involving a metal rod die insert as is required with conventional hinge molding techniques.
The base 12 is molded in a similar fashion to create a continuous passage for a hinge pin. Tab portions 90 of hinge member 86 include cavity sections 92 ( FIG. 3B ) perpendicular from the plane of base 12 . Accordingly, cavities 94 ( FIG. 3E ) are also incorporated in a direction parallel to the plane of base 12 . Cavities 92 and 94 cooperate to form a continuous passage 96 ( FIG. 3B and FIG. 3D ).
Turning now to FIGS. 4A through 4D , the interior of case 10 includes two symmetric transparent cover plates 16 , 18 . The cover plates 16 , 18 are molded with the same hinge strategy as mentioned for the cover 14 and base 12 . The tab portions 102 of hinge sections 100 include cavities 104 formed perpendicular to face 106 of cover plate 16 , 18 on a first side of the cover plates 16 , 18 . Cavities 108 are also formed from the geometry of the die and are perpendicular to face 106 on a second side of the cover plates 16 , 18 . Cavities 104 and 108 are parallel to each other and offset which cooperate to form a continuous passage 110 ( FIG. 4D ). The tab portions 102 of the cover plates are laterally offset such that a first cover plate 16 may be turned 180 degrees from a second cover plate 18 allowing the tab portions 102 to interfit. This feature allows both cover plates 16 , 18 to be molded from the same die. Cover plates 16 , 18 include a slot 112 integrated thereon to accept slidable latches 70 , 70 ′ ( FIGS. 1 and 6 ).
As best shown in FIG. 4B , cover plates 16 , 18 further include a raised lip or edge 62 . Raised edge 62 is preferably formed around the side walls 55 and at least a portion of the top wall 56 of the cover plates. Raised edge 62 provides increased structural strength and rigidity to cover plates 16 , 18 . In this manner, raised edge 62 resists twisting and fatigue associated with repeated manipulation of the cover plates. In a preferred orientation, the raised edge 62 extends toward inner surface 22 and 34 of the cover and base respectively.
Referring now to FIGS. 8A and 8B , tab portions 90 of hinge 86 of the base 12 are offset from hinge portions 78 of cover 14 so as to interfit when mated. Furthermore, the tab portions 102 of the cover plates 16 , 18 are positioned between hinge members 86 , 76 of the base 12 and cover 14 , respectively (placing FIG. 8B onto FIG. 8A to create FIG. 1 ). The respective hinge portions 90 of base 12 , 78 of cover 14 and 102 of cover plates 16 , 18 interfit to define one continuous passage 114 aligned to accept a hinge pin 130 ( FIG. 1 ).
Turning now to FIG. 5 , the spacer 52 will now be described. A series of spacers 52 will be included for the user to customize the size of the inner compartments. Spacer 52 includes flared arms 116 having fingers 50 extending therefrom. The fingers 50 are adapted to slidably engage tabs 48 of cover 14 or tabs 68 of base 12 . The spacers are made from a flexible material such as soft rubber or other elastomeric material. The flared arms 116 of spacers 52 are contoured such that an object may be easily removed from the box without becoming caught in a 90 degree corner of an inner compartment. The internal configuration also provides shock resistance in the event of a drop or sudden impact.
Referencing now FIGS. 4A , 4 B and 6 with continued reference to FIG. 1 , the cover plates 16 will now be described. Cover plate 16 includes a latch 70 slidably engaged with slot 112 . The latch 70 (best shown in FIG. 6 ), includes body 74 , having an arm 98 and outwardly extending fingers 72 and tang 99 . Wing section 60 has a contoured surface to enhance grip while sliding latch 70 . Latch 70 is slidably engaged to slot 112 of cover plate 16 . When a cover plate 16 is in its closed position, latch 70 may be laterally moved such that fingers 72 of arm 98 engage the rear surface of slot 120 securing the cover plate 16 to base 12 in a locked position.
The second cover plate 18 (identical to the first cover plate but flipped 180 degrees) also includes a slot 112 ′ and latch 70 ′. The latch 70 ′ slidably engages slot 58 of cover 14 when in a locked position. The relationship of latches 70 , 70 ′ to cover plates 16 and 18 are such that the latches 70 , 70 ′ of the cover plates 16 , 18 must be in a locked position in order for the carrying case 5 to properly close. Explained further, if the latches 70 , 70 ′ are not in a locked position, the wing 60 of latches 70 , 70 ′ will abut against one another preventing the case 10 from properly closing.
Turning now to FIG. 7 with continued reference to FIGS. 2A and 2B , the cover 14 includes a slidable latch 80 . The slidable latch 80 includes outer circumferential wall 128 including fingers 122 for engagement with track 124 of base 12 and track 105 on cover 14 . Ribs 118 laterally extend from face 126 of latch 80 to improve grip.
Referencing FIGS. 10 and 11 , the mold used to construct the cover 14 of the storage container 10 will now be described. The tool 140 includes a first, second, and third die member 136 , 144 , and 138 . Die 136 includes vertical pegs 142 extending therefrom. The base 12 is molded from a similar tool having a corresponding peg and tab arrangement which are offset from those of the cover tool 140 such that the molded parts cooperate to form a hinge. As such, a similar die arrangement is used to mold the cover plates 16 , 18 .
The method of constructing the cover 14 and base 12 of storage container 10 , will now be described. In a first general step the preferred method of the present invention provides a first tool 140 having a first die member 136 including a series of pegs 142 extending in a first direction and a second die member 144 including a series of pegs 146 extending in a perpendicular direction.
In a second general step, the preferred method of the present invention introduces the molten plastic material to the first tool 140 .
In a third general step, the first, second, and third die members 136 , 144 , and 138 are removed to reveal a cover 14 having a first continuous passage 88 .
The base 12 is formed similar to the cover 14 .
The first continuous passage 88 of cover 14 is then aligned with the second continuous passage 96 of base 12 and the passage 110 through cover plates 16 , 18 . A pin 130 is inserted through the passages 88 , 96 and 110 .
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
|
A storage container having a unique hinge arrangement is provided. The container includes a cover and base portion having hinge portions extending therefrom. The hinge portions are molded from a die configuration that creates adjacent cavities formed vertically and laterally. The hinge portions are arranged such that the cover and base interfit to reveal a continuous passage. A pin is inserted through the continuous passage completing a workable hinge. The storage container includes internal lateral wall sections on the cover and base having tabs extending therefrom. The tabs are configured to accept removable spacers. The spacers include side walls that are contoured such that an object may be easily removed without becoming caught in an angled corner. Transparent lids are releasably latched to the inside of the cover and base. The latches for the lids are located in a position that requires each lid to be locked prior to closing the case.
| 1
|
BRIEF SUMMARY OF THE INVENTION
This invention relates to systems for inspecting resistance welding electrodes and, more particularly, to an improved inspection system for verifying that resistance welding electrodes have been properly dressed by an electrode tip dresser; that associated electrodes when installed in a weld gun are aligned with each other within predetermined tolerances; and that the weld pressure provided by the weld gun is within predetermined tolerances.
As is well known in the art, during resistance welding processes the tips of the electrodes tend to mushroom (flatten) due to the pressures applied by the associated weld gun and the heat generated by the electrical current that passes through the electrode tips. Also, for example, in the case of welding galvanized steel, a build-up of the brass alloy will form on the surface of the electrode tips. Both of such conditions are causes of poor welds being produced. Consequently, the electrode tips must be dressed periodically to insure that the tip configuration is maintained within predetermined tolerances. As is also well known in the art, in automated welding systems the use of automatic electrode tip dressers has been developed. Although the automated tip dressers are reliable there are cases in which the electrode tips are not properly dressed or are not dressed at all, because of broken or dull dresser cutter blades or other factors.
It is also well known in the art of resistance welding that correct alignment of the electrode tips is essential for good tip life and quality of weld. Loss of alignment may indicate that some part of the weld gun or head is not tightly secured or the electrode shank may have become bent in operation. Electrode pressure applied by the weld tips to the workpiece is also very important in producing successful welds. If the weld pressure is not maintained within predetermined parameters and the pressure is greater than required to produce a good weld, a shortened tip life may result. On the other hand, if the pressure is less than required the weld electrodes may not bring the two sheets of workpiece material together so that a proper weld may be made. Electrode tips that are not properly dressed or that are not properly aligned or if the weld pressure is not correct can result in welds of poor quality, and in some cases no welds whatsoever are produced. Consequently, the resulting substandard parts can have various types of negative consequences, such as requiring the reworking of parts, added costs, necessity of parts sorting, possible liability issues, poor customer relations and other adverse consequences.
An object of the present invention is to overcome the aforementioned problems which can be created when the tips of resistance welding electrodes are not properly dressed or are not properly aligned or when an improper weld pressure is applied to the associated workpieces, and to provide an improved inspection system for verifying that resistance welding electrode tips have been properly dressed, properly aligned, and that proper weld pressure has been applied to the workpieces thereby reducing the risks involved in the spot welding of metal components, and also reducing the problems that can be caused by welding with electrodes having tips that are not properly dressed, or are not properly aligned, or without proper weld pressure being applied to the workpieces.
Another object of the present invention is to provide an improved inspection system incorporating novel low pressure air sensing means for evaluating welding electrode tip faces, physical shape and condition, and the relationship of such tips to predetermined criteria.
Another object of the present invention is to provide an improved inspection system incorporating low pressure air sensing means capable of simultaneously sensing two opposing electrode tips to evaluate the suitability thereof for continuing welding operations satisfying predetermined standards.
Another object of the present invention is to provide an improved inspection system embodying low pressure air sensing means incorporating interchangeable collets permitting the inspection of welding electrodes of various sizes and shapes merely by interchanging the collets.
Another object of the present invention is to provide an improved inspection system that permits two welding electrodes of different sizes and shapes to be inspected at the same time.
A further object of the present invention is to provide an improved inspection system for verifying that the tips of welding electrodes have been properly dressed, and which system is capable of being mounted in close proximity to an electrode tip dresser machine and/or a welding gun.
Another object of the present invention is to provide an improved inspection system for verifying that the tips of welding electrodes are in correct alignment with each other within predetermined criteria.
A further object of the present invention is to provide an improved inspection system for verifying that the pressure applied to the workpieces by the electrodes is correct in accordance with predetermined requirements.
Another object of the present invention is to provide an improved inspection system that will verify weld tip geometry, weld tip alignment and weld tip pressure all simultaneously.
A further object of the present invention is provide an improved inspection system that will provide an output signal to a machine controller respecting whether the electrode tips meet predetermined requirements concerning tip alignment, tip geometry and weld pressure.
Yet another object of the present invention is provide an improved inspection system that is relatively easy to manufacture and assemble at economical cost while providing long life and reliable operation.
The above as well as other objects and advantages of the present invention will become apparent from the following description, the appended claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a control unit that may be used in the inspection system embodying the present invention;
FIG. 2 is a schematic elevational view of a portion of the inspection system embodying the present invention, showing the same in relationship with respect to a welding gun having opposed welding electrodes;
FIG. 3 is an enlarged perspective view of components of the inspection system illustrated in FIG. 2;
FIG. 4 is a longitudinal, sectional view of portions of the structures illustrated in FIGS. 2 and 3;
FIG. 5 is a cross-sectional view of a portion of the structure illustrated in FIG. 4 and illustrating a properly dressed welding electrode tip inserted therein;
FIG. 6 is a cross-sectional view similar to FIG. 5 and illustrating an improperly dressed electrode tip inserted therein;
FIG. 7 is a cross-sectional view of another embodiment of the invention and illustrating a light path when the weld electrodes are properly aligned;
FIG. 8 is a cross-sectional view similar to FIG. 7 and illustrating a light path when the weld electrodes are improperly aligned;
FIG. 9 is a top view of the structure illustrated in FIG. 7;
FIG. 10 is a sectional view of another embodiment of the invention incorporating a support column to control the depth of penetration of an electrode if the face thereof is too small;
FIG. 11 is a sectional view of another embodiment of the invention having a pair of collets incorporating a secondary air passageway in each collet to verify the diameter of the electrode tip; and
FIG. 12 is an exploded sectional view of a portion of the structure illustrated in FIG. 11 .
DETAILED DESCRIPTION
Referring to the drawings, the present invention is illustrated as embodied in an inspection system, generally designated 10 , which is particularly adapted for use in verifying that resistance welding electrodes have been properly dressed by an electrode tip dresser; that the electrode tip geometry is suitable for welding operations; that opposed electrodes are aligned with each other within predetermined tolerances; and that the weld gun applies the appropriate pressure to obtain a satisfactory spot weld, i.e. the weld pressure exerted by the weld gun meets predetermined criteria. It will be understood however that the present invention is also applicable to other uses.
Referring to FIG. 1 of the drawings, a control unit, generally designated 15 , is illustrated therein that may be used in the inspection system 10 . The control unit 15 may be of the type illustrated and described in U.S. Pat. No. 5,814,720, issued to the inventor of the present application on Sept. 29, 1998 for an Air Pressure Sensor Control System, and the entire disclosure of U.S. Pat. No. 5,814,720 is hereby incorporated herein by reference. The control unit 15 includes a bulkhead fitting 12 which is adapted to be connected to a suitable source of air pressure (not shown), the air pressure preferably being supplied at 60-120 PSIG with suitable air filtering whereby dirt particles and other foreign matter are removed from the incoming air. The air flows from the bulkhead fitting 12 through a hose 14 to a conventional air pressure regulator 16 incorporating a conventional air pressure gauge 18 . The air pressure regulator functions to reduce the operating pressure required to operate the system to approximately 0.5 to 8 PSIG depending upon the particular application. The low pressure air is then delivered into a common port manifold 20 through the agency of a hose 22 , the common port manifold being equipped with suitable needle valves, such as 24 , from which the volume of air is then delivered via hoses, such as 26 , 28 , 30 and 32 to the inlet end portions of associated switch air passageways internally defined by an electro-pneumatic interface module 38 , four such switch air passageways being internally defined by the electro-pneumatic interface module illustrated in FIG. 1 of the drawings.
The internal switch air passageways communicate with conventional pneumatic/electric switches 42 which are adapted to open and close as a function of variations in the air pressure in the switch air passageways. Each pneumatic/electric switch 42 (four such switches being illustrated in FIG. 1 of the drawings) is electrically connected to a terminal block 44 through the agency of wires, such as 46 , the terminal block 44 , in turn, being connected to a conventional programmable logic controller 48 by wires such as 50 , a relay 52 being provided to relay appropriate signals to a welding machine or other equipment being controlled by the air pressure sensor control unit 15 . The air entering the inlet of each switch air passageway flows through such passageway and exits the switch air passageway through hoses such as 54 and 56 to a terminal fitting, such as 58 , connected to a sensor 116 as will be described hereinafter in greater detail.
A conventional weld gun 118 is schematically illustrated in FIG. 2 of the drawings, the gun having an upper electrode 120 and a lower electrode 122 which cooperate with each other to resistance weld workpieces disposed between the electrodes 120 and 122 which must be properly dressed through the agency of an automatic electrode tip dresser or other suitable dresser means. The inspection system 10 embodying the present invention may be mounted in close proximity to the weld gun 118 as illustrated in FIG. 2 of the drawings, or the inspection system may be mounted on a dresser machine framework or on a separate pedestal as desired.
In addition to the control unit 15 , previously described, the inspection system 10 includes a sensor 116 which is connected by air hoses, such as 56 , to the control unit 15 . The sensor 116 includes a high precision combined light generating and reflected light sensing unit 114 which may be of the type commercially identified as “STM Sensor Incorporated,” Model V6A Optic Amplifier, available from Industrial Control, Inc., Zeeland, Mich. 49464. The unit 114 has a light generating and reflected light cable head 128 effective to detect misalignment of the electrodes as will be described hereinafter in greater detail. A force load cell 182 is also provided which may be identified as “Cooper Instruments and Systems,” Model LZBS 1010 2K, also available from Industrial Control, Inc., Zeeland, Mich. 49464.
The sensor 116 includes a top plate 124 and a bottom plate 126 , and the sensor 116 is connected to a manifold 112 by air passageways in the top plate 124 and bottom plate 126 , respectively. Inlet ports such as 142 and 143 on the side of the manifold 112 are connected by air hoses, such as 56 , to the control unit 15 . Means is also provided for back pressure developed at the sensor 116 to be communicated to the control unit 15 . The air entering the passageways 173 A and 173 B and 175 A and 175 B defined by the sensor 116 flows through such passageways and exits to atmosphere if there is no obstruction of orifices defined by the sensor 116 , as will be described hereinafter in greater detail. If there is an obstruction of an orifice, the air will be blocked from exiting the sensor 116 whereupon the associated pneumatic/electric switch 42 will be actuated due to the increase in back pressure thereby providing a circuit to the programmable logic controller 48 , the programmable logic controller, in turn, controlling a welding machine or other equipment through the agency of the relay 52 . It should also be understood that the air volume for each air passageway in the sensor 116 may be adjusted through the agency of the needle valves 24 which control the flow of air through the common port manifold 20 . It should also be pointed out that, if desired, the main components of the control unit 15 may be housed in a conventional NEMA enclosure 60 with the hoses 56 projecting from the enclosure 60 .
As shown in the drawings, the sensor 116 includes a pair of interchangeable collets 164 and 166 which are mounted on one end portion of the elongated mounting plates 124 and 126 and retained therein through the agency of retainer rings 136 and 137 , respectively, secured to the mounting plates 124 and 126 , as by screws 138 as illustrated. The mounting plates 124 and 126 are preferably made of aluminum or of any other suitable material having sufficient strength to withstand the forces exerted thereon. As shown in FIGS. 2 and 3 of the drawings, the other end portions of the mounting plates support the amplifier 114 and the manifold 112 .
The collets 164 and 166 define concave cavities 168 and 170 of a configuration that is complementary to the face of the tip of the particular electrode being inspected. It will be understood that there are numerous sizes and shapes of welding electrodes that can be used in resistance welding processes, and the collets 164 and 166 are preferably made of hardened steel to resist wear and also withstand the forces applied thereto. As shown in FIG. 4, the collets preferably have a taper 154 at the mouth side thereof to assist in aligning the electrodes with the shaped cavity in the collets. As shown in the drawings, the collets 164 and 166 define a pair of passageways 172 and 174 . One end of the passageway 172 communicates with the cavity 168 while the other end of the passageway 172 communicates with a passageway 173 B connected to the control unit 15 by the passageway 173 A and a hose 56 . One end of the passageway 174 communicates with the cavity 170 while the other end of the passageway 174 communicates with a passageway 175 B which in turn is connected to the control unit 15 by the passageway 175 A and a hose 56 . When the electrode is properly dressed it will restrict the flow of air through the passageways 178 and 180 thereby causing an increase in back pressure in the sensor back to the control unit 15 . The vents 178 and 180 provided in each of the collets allow air to escape to the atmosphere if an electrode tip is not properly dressed and therefore will not create an increase in back pressure within the control system.
As is well known in the art, standard welding electrodes are supplied in different diameters and different tip geometries, and special shapes are often produced to meet specific requirements. The inspection system embodying the present invention requires that only the collets need to be changed to match the selected electrodes required for any particular welding application. It will be understood that both of the collets may be of the same configuration or may be of different configurations or they may be matched to any combination of electrodes as required by the particular welding operation.
As is well known in the art, the electrodes 120 and 122 must be aligned with each other to obtain a satisfactory weld. As shown in FIGS. 4, 7 and 8 , light emitted from 128 will pass through the passageways 194 and 196 if the electrodes are aligned within predetermined values. When the electrodes are disposed in the cavities 168 and 170 and are misaligned, the collets are allowed to shift laterally within the mounting plates causing a misalignment between the passageways 194 and 196 . The light generated by the cable head 128 will be reflected by the surface of the collet 166 and through the associated passageway 194 back to the cable head 128 and thereafter will be transmitted back to the amplifier 114 . The unit 114 will provide an output to the machine controller (not shown) so that in a conventional manner the machine controller can sound an alarm and/or shut down the welding operation and/or otherwise alert the user thereof that the electrode alignment did not pass inspection.
As previously mentioned, the collets 164 and 166 are enabled to shift laterally in relationship to each other. Alignment springs, such as 186 , each in the form of a flexible plug are provided which allow the collets 164 and 166 to reposition themselves when a dislocation force is applied and will return the collets 164 and 166 back to center line with each other when the dislocation force is removed. “O” rings 188 and 190 are provided to maintain the collets on center line within the sensor 116 . When a dislocation force is applied the “O” rings 188 and 190 will collapse and the “O” ring portion on the opposite side of the collet will expand. When the dislocation force is removed the two collets 164 and 166 will return to their neutral position on center line of the sensor 116 . The fiber optic cable head 128 emits a light beam which beam passes through the passage ways 194 and 196 . If the collets 164 and 166 are aligned within predetermined tolerances no output signal will be made. If the collets 164 and 166 are misaligned beyond the acceptable tolerances the light beam emitted from the passageway 194 will impinge on the adjacent surface of the collet 166 . The light is reflected by such surface back through the passageway 194 to the cable head 128 and transmitted back to the unit 114 through the cable 130 and an output signal will be sent to the machine controller.
As is well known in the art, the force of the electrodes bearing on the sheet metal must be maintained with respect to predetermined values. If the force is less than required, the electrodes may not bring the two sheets together so that a weld may be made. If the pressure is too high, the tip of the electrode will mushroom at a faster rate and may also cause excessive indentations in the surface of metal being welded. The embodiment of the invention illustrated in FIG. 4 includes a force sensor 182 positioned between the collets 164 and 166 , during inspection of the electrodes, the electrodes 120 and 122 are disposed in the cavities 168 and 170 defined by the collets 164 and 166 . Pressure is then applied by the weld gun as if it were in the weld position. The value of the force applied by the collets 164 and 166 to the force sensor 182 is transmitted by the cable 146 to a conventional amplifier and digital display (not shown) in the machine controller for evaluation by the machine operator.
FIG. 5 illustrates the manner in which a properly dressed electrode blocks the passageway 172 and the entrance to the passageway 178 thereby preventing the escape of air to atmosphere through the passageway 178 and providing a circuit to the programmable logic controller 48 in the manner previously described. FIG. 6 illustrates the condition in which an improperly dressed electrode fails to block the passageway 172 and the entrance to the passageway 178 thereby permitting air to escape to atmosphere through the passageway 178 with the result that there will not be an increase in the air back pressure which can be communicated to the unit 15 in the manner previously described.
FIG. 10 illustrates an embodiment of the invention wherein support pins 169 and 171 are provided to control the depth of penetration of an electrode into the cavities 168 and 170 if the face of the electrode is too small. This prevents the passageways 172 and 174 from being restricted, and air will flow through the passageways 178 and 180 to atmosphere in the manner previously described.
In the embodiment of the invention illustrated in FIGS. 11 and 12, collets 164 C and 166 C are provided, the collet 164 C defining concentric air passageways 172 C and 172 D communicating with the cavity 168 C while the collet 166 C defines concentric air passageways 174 C and 174 D communicating with the cavity 170 C. The collet 164 C also defines an air passageway 178 C one end of which communicates with the cavity 168 C while the other end of the passageway 178 C communicates with atmosphere. The collet 166 C also defines an air passageway 180 C one end of which communicates with the cavity 170 C while the other end of the passageway 180 C communicates with atmosphere.
In this embodiment of the invention, as shown in FIGS. 11 and 12, the collet 164 C defines an air passageway 173 C one end of which communicates with the air passageway 172 C while the other end of the passageway is connected to the control unit 15 through the passageway 173 D. The collet 164 C also defines an air passageway 173 E one end of which communicates with the passageway 172 D while the other end of the passageway 173 E is connected to the control unit 15 through the passageway 173 F. The collet 166 C defines an air passageway 175 C one end of which communicates with the passageway 174 C while the other end of the passageway 175 C is connected to the control unit 15 through the passageway 175 D. The collet 166 C also defines an air passageway 175 E one end of which communicates with the passageway 174 D while the other end of the passageway 175 E is connected to the control unit 15 through the passageway 175 F.
In this embodiment of the invention if the tip of an electrode inserted in the cavity 168 C blocks the passageway 172 D, such blockage indicates that the tip is too large, and such blockage is communicated to the control unit 15 through the passageways 173 E and 173 F in the manner previously described, the control unit 15 in turn being programmed so as to indicate that the tip of the electrode has blocked the passageway 172 D. On the other hand, if the tip of an electrode inserted in the cavity 168 C blocks the passageway 172 C, such blockage indicates that the electrode is properly dressed as described herein above. It will be understood that similar results will be obtained if the tip of an electrode is inserted in the cavity 170 C, the manner of operation of the collet 166 C and the associated structure described hereinabove will correspond with the manner of operation of the collet 164 C and the associated structure described hereinabove.
While preferred embodiments of the invention have been illustrated and described, it will be understood that various changes and modifications may be made without departing from the spirit of the invention.
|
An improved inspection system for verifying that resistance welding electrodes have been properly dressed; that associated pairs of the electrodes are aligned with each other within predetermined tolerances; and that the pressure applied by a weld gun to the electrodes and material being welded is within predetermined standards. The system incorporates low pressure air apparatus that evaluates the back pressure resulting from the fit of collet geometry relative to the form of the electrode tip, and apparatus to verify the alignment of opposing electrodes with respect to each other and incorporating fiber-optic sensors that evaluate the alignment of collets with respect to each other. The system also provides apparatus for verifying that the proper pressure is applied to the workpieces by the electrodes during the welding operation.
| 1
|
TECHNICAL FIELD
This invention relates to ground drilling equipment. Specifically, this invention relates to connection designs for components of drill stems.
BACKGROUND
Directional drilling is a useful technique for several procedures such as utility installation, etc. One common type of directional drilling is horizontal directional drilling, where a drill stem is extended essentially horizontally to form passages under structures such as roads for example.
The drill stem typically includes multiple components, including a drill head, a sonde housing, sections of drill rod, etc. Drill heads in directional drilling typically have a feature which causes the drill head to steer in one direction when forced ahead by a drilling device. During a boring operation, pressure is applied through the drill stem from behind to the drill head. During a straight bore, the drill stem is typically rotated at a regular rate so that on average, only straight ahead drilling is accomplished. In order to steer a drill head, the rotation is temporarily stopped, and the drill head is allowed to steer in the desired direction. Once the steering maneuver is complete, the drill head is again rotated at a regular rate for straight ahead drilling.
Ground drilling requires large amounts of forward linear force, as well as large amounts of torque, applied to the drill stem. The drill stem also experiences frictional forces due to the interaction of the drill stem with the medium (i.e., soil, rock, sand, clay, etc.) through which the drill stem is traveling during a boring operation. Therefore, for a successful boring operation, it is necessary that the components, as well as the couplings therebetween, be able to withstand the various drilling forces without failure.
Various coupling designs and methods have been employed to connect drill stem components. One common method of connecting drill stem components is to threadingly couple one component to another, such that the linear and the rotational forces experienced during a drilling operation are transmitted from one component to the other through the threads of the adjoining components. Because of this, such threaded couplings are difficult to remove after the drilling operation is complete due to tightening of the threads during rotation of the drill stem in a drilling operation. Large tools, such as a pipe wrench, are frequently needed to disconnect the threaded-together drill stem components. Pipe wrenches or similar methods requiring large forces are inconvenient, and may be dangerous to the operator.
What is needed is a drill stem component connection system and method that provides structural integrity for drilling operations, while providing ease of assembly and disassembly with an increased level of safety.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a drilling device according to an embodiment of the invention.
FIG. 2 shows a drilling device according to an embodiment of the invention.
FIG. 3 shows a threaded collar of a drilling device according to an embodiment of the invention.
FIGS. 4A-4C show views of a threaded collar of a drilling device according to an embodiment of the invention.
FIG. 5 shows an adapter of a drilling device according to an embodiment of the invention.
FIGS. 6A-6C show views of an adapter of a drilling device according to an embodiment of the invention.
FIG. 7 shows a drill stem section of a drilling device according to an embodiment of the invention.
FIG. 8 shows a drill stem section of a drilling device according to an embodiment of the invention.
FIGS. 9A-9C show views of a drill stem section of a drilling device according to an embodiment of the invention.
FIG. 10 is a cross-sectional view of the drill stem section of FIG. 9C taken along line 10 - 10 .
FIG. 11 is an exploded view of a drilling device according to an embodiment of the invention.
FIG. 12 shows a drill stem component of the drilling device of FIG. 11 .
DETAILED DESCRIPTION
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. In the drawings, like numerals describe substantially similar components throughout the several views. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and structural, or logical changes, etc. may be made without departing from the scope of the present invention. In the following descriptions, a drill stem is defined to include any component that is advanced from a drilling device. A drill rod is defined as a section of pipe, solid material, etc. where sections of drill rod are coupled together to form a main part of a drill stem. Various drill stem components such as a drill head, a drilling blade holder, a sonde housing, etc. can be attached to the front end of a number of drill rods during one embodiment of a typical drilling operation.
Referring to FIGS. 1 and 2 , there is shown a drilling device. Although an example of a directional drill stem portion 10 is used in the following descriptions, other drilling devices utilizing a number of sections of drill stem are also contemplated to be within the scope of the invention. It is noted that, while the drill stem portion 10 of FIGS. 1 and 2 is shown in isolation, it is intended that in use the drill stem portion 10 be attached to an end of a drill rod (not shown) at least during directional drilling. Additionally, typically, the drill stem portion 10 will be drivingly coupled to a drilling apparatus (not shown) during directional drilling. In this example, the drill stem portion 10 includes a threaded collar 20 , an adapter 30 , and an end portion 40 . The end portion 40 , in at least this example, includes a sonde housing 42 and a drill head 44 .
Referring to FIGS. 5 and 6 A- 6 C, the adapter 30 is generally cylindrical in shape, having a side wall 30 a disposed between a first end 30 b and a second end 30 c. The first end 30 b of this example includes interior adapter threads 36 configured to selectively engage conical threads (not shown) of an end of a drill rod (not shown). In other examples, it is contemplated that engagement structures other than conical adapter threads 36 are used at the first end 30 b. The adapter 30 further includes a central passage 30 d therethrough disposed between the first and second ends 30 b, 30 c through which fluid (not shown), such as bentonite fluid or other drilling fluid, optionally travels. Proximate the second end 30 c, the central passage 30 d includes a radial passage 38 that extends through the side wall 30 a for fluid connection with a fluid passage within the end portion 40 , which will be described in greater detail below. Although the end of the central passage 30 d is shown as extending through the second end 30 c of the adapter 30 , in one example, it is intended that the end be closed off in a known way, such as by welding, inserting a stopper, etc., so that the fluid flows through the radial passage 38 and does not flow out of the second end 30 c of the adapter 30 . Although only one radial passage 38 is shown, it is within the spirit and scope of the present invention that there be more than one passage to facilitate the passage of fluid from the central passage 30 d to the fluid passage of the end portion 40 . An exterior of the side wall 30 a of one example of the adapter 30 includes O-ring slots 35 on either longitudinal side from the radial passage 38 for accepting O-rings (not shown) for sealingly engaging the adapter 30 within the end portion 40 to inhibit fluid leakage into the interior of the end portion 40 .
The adapter 30 , in one example, further includes an engagement feature in the form of exterior adapter splines 32 disposed proximate the second end 30 c of the adapter 30 . In one embodiment, the adapter splines 32 are generally longitudinally oriented with respect to the adapter 30 . The adapter 30 , in one example, further includes a raised shoulder 34 optionally including a generally circumferential channel 34 a, as shown in FIG. 5 , for engagement with the threaded collar 20 , as will be described below. In another example, the adapter 30 includes only a raised shoulder 34 , as shown in FIGS. 6A and 6B , and does not include a circumferential channel. The shoulder 34 and optional circumferential channel 34 a are configured for engagement with the threaded collar 20 , as will be described in greater detail below.
Referring to FIGS. 7-10 , the end portion 40 is generally cylindrical and includes a side wall 40 a disposed between a first end 40 b and the drill head 44 . At least the sonde housing 42 of the end portion 40 includes a generally hollow interior 40 c extending from the first end 40 b to the drill head 44 . In this example, the hollow interior 40 c is configured to optionally accept a sonde (not shown) for sensing and sending drilling environment data to a user in a manner that is generally known to those skilled in the art. The side wall 40 a in the area of the sonde housing 42 includes windows 40 d therethrough to allow radio waves or other such sensing signals emitted from the sonde to exit the sonde housing 42 . In one example, the end portion 40 includes three windows 40 d, although it is within the spirit and scope of the present invention that there be more or less than three windows 40 d through the side wall 40 a, provided the sensing signals of the sonde are able to exit the sonde housing 42 in order to sense drilling environment characteristics. Additionally, although not shown in the figures, the windows 40 d are intended to be covered or filled with epoxy or other such material that is permeable with respect to radio waves or other such signals emitted by the sonde. By filling or otherwise covering the windows 40 d, fluid can be prevented or at least inhibited from entering the interior 40 c of the end portion 40 , thereby at least reducing the likelihood that the sonde inside the sonde housing 42 will become damaged by fluids, soil, mud, and other drilling-related contaminates encountered by the drill stem portion 10 during directional drilling.
In one example, the end portion 40 further includes end portion threads 46 on end exterior surface of the side wall 40 a, disposed proximate the first end 40 b. The end portion threads 46 are configured to engage the threaded collar 20 , as described in more detail below. End portion splines 48 are disposed on an interior surface of the side wall 40 a proximate the first end 40 b. The end portion splines 48 are configured, in this example, to mate with and engage the adapter splines 32 , such that, when engaged with the adapter splines 32 , relative rotational motion of the adapter 30 with respect to the end portion 40 is inhibited thereby. Although a plurality of end portion splines 48 are shown disposed around the entire interior circumference of the end portion 40 and a plurality of adapter splines 32 are shown disposed around the entire exterior circumference of the adapter 30 , it is within the spirit and scope of the present invention that the adapter and end portion splines 32 , 48 be configured differently. For instance, the adapter splines 32 could be configured around an interior circumference of the adapter 30 and the end portion splines 48 could be configured around an exterior circumference of the end portion 40 . Also, the adapter splines 32 could be disposed only around a portion of the circumference of the adapter 30 with the end portion splines 48 disposed around a corresponding portion of the circumference of the end portion 40 . Additionally, one of the adapter 30 and the end portion 40 could have as few as one spline forming a projection and the other of the adapter 30 and the end portion 40 could have as few as two splines forming a slot for engagement of the projection therewith. Although not expressly shown or described herein, further engagement variations are contemplated in the present invention.
In one example, the drill head 44 of the end portion 40 includes a plurality of holes 44 a for optional engagement of additional components such as steering blades (not shown), etc. with the drill head 44 . In one example, the holes 44 a are threaded for receiving fasteners (not shown). Additionally, the drill head 44 of this example includes a slot 44 b for insertion and retention of a fluid port (not shown) or other tool and/or component suitable for use with a directional drill. The use of a steering blade is generally known in the art and, for this reason, will not be described in detail herein. The drill head 44 further includes a drill fluid outlet 44 c ( FIG. 7 ) for discharging drill fluid (not shown) into the fluid port within the slot 44 b or otherwise discharging drill fluid within the drill hole during directional drilling. Fluid is often used to loosen the soil in the vicinity of the steering blade, thus making the drilling operation easier. In one example, the drilling fluid includes a bentonite lubricant. The drill fluid outlet 44 c is fluidly coupled to the passage 38 of the adapter 30 with a drill fluid passageway 43 (see FIG. 10 ) in the side wall 40 a of the end portion 40 .
Referring now to FIGS. 3 and 4 A- 4 C, the threaded collar 20 in one example includes a generally cylindrical side wall 20 a disposed between first and second ends 20 b, 20 c. The threaded collar 20 is configured to fit over the adapter 30 and at least a portion of the end portion 40 to act to couple the adapter 30 to the end portion 40 . In one example, the threaded collar 20 includes collar threads 26 on an interior surface of the side wall 20 a configured to threadingly engage the end portion threads 46 described above. The collar threads 26 are configured to inhibit if not prevent loosening of the threaded collar 20 during rotation of the drill stem portion 10 during directional drilling. In one embodiment, the collar threads 26 are configured to be left-hand tightening threads so that rotation of the drill stem portion 10 , which is intended to be rotated in a right-hand rotational direction, and, more specifically the frictional interaction of the drill stem portion 10 with respect to the material being drilled causes further tightening of the threaded collar 20 .
Tightening of the collar threads 26 with the end portion threads 46 causes compression of a collar shoulder 20 d of the threaded collar 20 against the shoulder 34 of adapter 30 to engage the adapter 30 with the end portion 40 . In this way, tightening of the collar threads 26 with the end portion threads 46 inhibits axial movement of adapter 30 with respect to the end portion 40 . Through holes 28 of the threaded collar 20 are configured to accept set screws (not shown) for optional engagement within channel 34 a to further affix the threaded collar 20 to the adapter 30 . Two holes 28 are shown in this example, although it is contemplated that there be more or less than two holes 28 .
In one example, the collar threads 26 include one continuous thread with the end portion threads 46 including a corresponding thread. In another example, the collar threads 26 and the end portion threads 46 include more than one thread. In yet another example, the collar threads 26 and the end portion threads 46 include multiple, interlaced threads. For instance, the collar threads 26 could include two, three, or more interlaced threads with the end portion threads 46 including a corresponding number of threads. Multiple threads provide the same engagement surface area between the end portion threads 46 and the threaded collar threads 26 as a single thread. However, fewer rotations of the threaded collar 20 are required with multiple threads than are required for a single thread, leading to faster engagement/disengagement of the threaded collar 20 with the end portion 40 .
The threaded collar 20 further includes end holes 24 disposed around the first end 20 b configured to accept carbide blades to scrape away drill residue, i.e., caked on mud, rock, etc. during loosening of the collar 20 . Although four end holes 24 are shown, it is contemplated that there be more or less than four end holes 24 . Spanner features 22 , such as holes, flats, etc., are located in an exterior of the side wall 20 a. The spanner features 22 in this example only partially extend through the side wall 40 a and are configured for engagement with a spanner (not shown) or other such tool configured to be used to tighten and/or loosen the threaded collar 20 . In this example, there are two diametrically opposed spanner features 22 , although it is within the spirit and scope of the present invention that there be more or less than two spanner features and/or that the spanner features not be diametrically opposed, provided a tool such as a spanner is still capable of being used to tighten and/or loosen the collar threads 26 of the threaded collar 20 .
In this way, once engaged in a securing position (see FIGS. 1 and 2 ), the threaded engagement of the threaded collar 20 with the end portion 30 maintains the end portion 40 in engagement with the adapter 30 and, thereby, maintains mating engagement of the adapter splines 32 with the end portion splines 48 to transmit torque between the adapter 30 and the end portion 40 . The engagement of the collar threads 26 with the end portion threads 46 transmits axial forces along the drill stem portion 10 but does not transmit torque forces due to the above-described interaction of the end portion splines 48 and the adapter splines 32 . By isolating the torque forces and the axial forces in this way, the threaded collar 20 does not become over-tightened by rotation of the drill stem portion 10 during a drilling operation and, therefore, requires relatively little force by a user to remove the threaded collar 20 from the end portion threads 46 , when it is desired to disassemble the drill stem portion 10 after a drilling operation.
The threaded collar 20 , when engaged with the adapter 30 and the end portion 40 , not only acts to maintain connection of the adapter 30 and the end portion 40 , but also protects a joint between the adapter 30 and the end portion 40 by at least partially covering the joint. In one example, the threaded collar 20 completely covers the joint to inhibit encroachment of drilling byproducts, such as fluid, soil, rocks, etc., within the joint.
In operation, the threaded collar 20 is slidably disposed between the first end 30 b and the shoulder 34 of the adapter with the second end 20 c of the threaded collar 20 facing in the direction of the second end 30 c of the adapter 30 . The adapter threads 36 of the adapter 30 are then threadably engaged with an end (not shown) of a generally known drill rod (not shown). The first end 40 b of the end portion 40 is then slipped over the second end 30 c of the adapter 30 so that the adapter splines 32 engage with the mating end portion splines 48 , with the first end 40 b of the end portion 40 abutting the shoulder 34 of the adapter 30 in one example. The treaded collar 20 is passed along the adapter 30 toward the end portion 40 and into engagement with the end portion threads 46 , at which point the collar threads 26 are engaged therewith. Optionally, a spanner (not shown) can be engaged with the spanner features 22 of the threaded collar 20 to gain a mechanical advantage in order to further tighten the threaded collar 20 onto the end portion threads 46 , thereby compressing the joint between the end portion 40 and the adapter 30 . Optionally, set screws (not shown), such as allen bolts, hex bolts, screws, and the like, can be threaded into the through holes 28 in the threaded collar 20 , such that ends of the set screws become disposed within the channel 34 a, further optionally biting into an exterior of the adapter 30 within the channel 34 a. In this way, the threaded collar can be optionally further engaged with the drill stem portion 10 to lessen the likelihood that the threaded collar 20 becomes dislodged from its engagement with the end portion 40 . The drill stem portion 10 can then be used in a directional drilling operation to bore through soil, rock, clay, etc. in order to create a directional drilling hole in a manner generally known to those skilled in the art. It is further contemplated that the collar threads 26 be left-handed, such that frictional interaction of the threaded collar 20 with the drill bore causes further tightening of the threaded collar 20 onto the end portion threads 46 to further lessen the likelihood of disengagement of the end portion 40 . This promotes a secure attachment of the end portion 40 and the adapter 30 during a drilling operation. Because the threaded collar 20 at least partially covers the joint between the end portion 40 and the adapter 30 , the joint is protected from the incursion of drilling byproducts, such as soil, rocks, fluid, etc.
After performing a desired drilling operation, the drill stem portion 10 can be removed from within the drill bore, either by backing the drill stem portion 10 out or by passing the drill stem portion 10 completely through the drill bore. At this point, if desired, the end portion 40 can be removed from the adapter 30 by loosening the threaded collar 20 . If used, the set screws of the threaded collar 20 are loosened to disengage the set screws from within the channel 34 a of the adapter 30 . The threaded collar 20 is then loosened and removed from engagement with the end portion threads 46 . As discussed above, because the collar threads 26 are only tightened due to friction, are not tightened due to drill stem rotation, a lower amount of force is required to loosen the threaded collar 20 . Optionally, the spanner is engaged within the spanner features 22 and is used to gain a mechanical advantage in loosening the thread collar 20 from engagement with the end portion 40 . Use of the spanner in this way eliminates the unsafe and relatively common practice of using pipe wrenches (not shown) or other such devices to loosen the sections of the drill stem.
Although the above description relates to the use of the threaded collar 20 with the end portion 40 and adapter 30 , it is within the spirit and scope of the present invention that the threaded collar 20 be used with other joints between other sections of the drill stem, including, but not limited to, between drill rods, between a drill rod and the sonde housing, between the sonde housing and the drill head, etc. Additionally, although the above description primarily relates to the adapter splines 32 and the end portion splines 48 as the engagement/mating features of the end portion 40 and the adapter 30 , it is within the spirit and scope of the present invention that other engagement/mating features be used in conjunction with the threaded collar 20 .
For instance, in another example, referring to FIGS. 11 and 12 , a sonde housing 142 includes at least one twist-and-lock slot 148 , and an adapter 130 includes at least one corresponding protruding lobe 132 for selective engagement within the twist-and-lock slot 148 . More information regarding this twist-and-lock configuration can be found in U.S. patent application Ser. No. 10/757,378 entitled Connection Design and Sonde Housing Assembly for a Directional Drill, which is incorporated by reference herein in its entirety. In one example, the twist-and-lock slot 148 is proximate a first end 140 b of the sonde housing 148 and includes a first portion 148 a generally longitudinally oriented with respect to the sonde housing 142 and a second portion 148 b generally radially oriented with respect to the sonde housing 142 . In this way, the protruding lobe 132 is inserted within the first portion 148 a, and the adapter 130 is twisted with respect to the sonde housing 142 to slide the protruding lobe 132 into the second portion 148 b and locked into place using, for instance, an insert 145 . Once the protruding lobe 132 is engaged within the second portion 148 b of the twist-and-lock slot 148 , a threaded collar (not shown, but substantially similar to the thread collar 20 discussed above) is threadably engaged with sonde threads 146 proximate the first end 140 b of the sonde housing 142 . In a manner similar to that described above, the threaded collar, as it is tightened, abuts a shoulder 134 of the adapter 130 and compresses a joint between the adapter 130 and the sonde housing 142 . In this way, the threaded collar acts to couple the sonde housing 142 and the adapter 130 and provides at least some protection from drilling byproducts of the joint to facilitate disassembly after use.
It is noted that the above-discussed examples of drill stem couplings including the threaded collar are merely exemplary and that other configurations not specifically discussed herein are considered to be within the spirit and scope of the present invention. For instance, the thread collar discussed herein could be used with other engagement/mating features of drill stem components, whether initially designed to be used with the threaded collar or whether existing drill stem components having engagement/mating features are retrofitted for use with the threaded collar.
The above-described drill stem coupling of the drill stem portion 10 , namely, the threaded collar 20 used in conjunction with the adapter 30 , 130 and the end portion 40 or sonde housing 142 , is intended to provide a robust coupling for use during drilling operations in which torque forces are isolated to lessen the likelihood of the drill stem components becoming overly tightened and, as a result, difficult to separate. Because torque forces do not act to further tighten the threaded collar 20 of the present invention, the threaded collar 20 is relatively easier to remove than previously known drill stem couplings. As such, the present invention decreases the need to use large pipe wrenches or other such tools, which can be dangerous for a user to try to use and/or restrain, especially when the user is within a confined area such as a drill pit.
Additionally, as stated above, the threaded collar 20 in the secured position acts to at least partially cover the joint between the adapter 30 , 130 and the end portion 40 or sonde housing 142 , which serves to protect the joint from incursion of dirt, fluid, and other drilling debris into and around the joint. In this way, the threaded collar 20 acts to inhibit such debris from becoming lodged in and around the joint, thereby facilitating disassembly of the adapter 30 , 130 and the end portion 40 or sonde housing 142 .
While a number of advantages of embodiments described herein are listed above, the list is not exhaustive. Other advantages of embodiments described above will be apparent to one of ordinary skill in the art, having read the present disclosure. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiment shown. This application is intended to cover any adaptations or variations of the present invention. It is to be understood that the above description is intended to be illustrative, and not restrictive. Combinations of the above embodiments, and other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention includes any other applications in which the above structures and fabrication methods are used. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
|
A drill stem connection assembly includes a first drill stem section and a second drill stem section. At least one engaging feature is located at an end of the first drill stem section. At least one mating feature accepts the at least one engaging feature. The at least one mating feature is located at an end of the second drill stem section. Coupling of the respective ends of the first and second drill stem sections forms a drill stem joint. A threaded collar engages with at least one of the coupled first and second drill stem sections. When placed in a securing position, the threaded collar holds the engaging feature securely mated with the mating feature and at least partially covers the drill stem joint.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
The present Application is based on International Application No. PCT/SG2006/000033, filed Feb. 20, 2006 which in turn corresponds to Malaysia Application No. PI 20051074, filed Mar. 15, 2005 and priority is hereby claimed under 35 USC §119 based on these applications. Each of these applications are hereby incorporated by reference in their entirety into the present application.
FIELD OF THE INVENTION
The present invention relates to glycolipids, more particularly, it relates to glycolipids comprising an alcohol branched in the 2-position that is covalently bonded to an oligosaccharide in either α- or β-linkage. The present invention also relates to liquid crystalline properties and self assembly of these glycolipids, which give rise to applications of these materials for surfactants, artificial membranes and medicines.
BACKGROUND OF THE INVENTION
Alkyl glycosides are compounds comprising a carbohydrate and an alcohol, chemically bound in a cyclic acetal. Compounds involving alkyl groups exceeding C 5 belong to a class of compounds called glycolipids, which are commonly known to show surfactant properties and have acquired some industrial impact for special application fields. Their role in biology is widely acknowledged.
Most of the applications for synthetic glycolipids rest on their molecular properties as described in U.S. Pat. Nos. 3,219,656, 3,547,828, 3,839,318 and EP 041960. These properties fall into two broad categories: adsorption and self assembly. The first indicates interfacial properties on water/oil, water/air or solid/gas interfaces. Connected applications are focusing on wetting, foaming, detergency and emulsions. The most important industrial roles of surfactants are connected with the formation of emulsions and with detergency. An emulsion is a dispersion of two normally immiscible fluids; thus emulsions are multiphase systems even though they might appear to look homologue. Detergency is responsible for most cleaning purposes. Both rheology (flow properties) and kinetics of mesophase formation (any non crystalline kind of self assembly of matter) in surfactant systems has high potential impact on manufacturing processes, since rheology might limit the handling of processes. Self assembly is the ability of matter to form supramolecular structures. Examples cover micelles, bilayers and other liquid crystals which all may exhibit applications on their own.
The liquid crystalline behavior of alkyl glycosides has been subject to several investigations (e.g. D. E. Koeltzow et al., J. Am. Oil Chem. Soc., 1984, 61, 1651; V. Vill et al., Liq. Cryst., 1989, 6, 349-356). However, while carbohydrate derived compounds have been found useful as additives for liquid crystal based switches with respect to their high optical twisting power (V. Vill et al., Z. Naturforschung A, 1989, 44, 675-679), alkyl glycosides so far did not acquire usage for liquid crystal applications. Their liquid crystal phase temperature range resemble a major disadvantage. Pure compounds exhibit liquid crystallinity only at temperatures higher than ambient temperature. Most technical applications, however, require (or at least favor) lower temperatures. The present invention enables the formation of liquid crystal phases for alkyl glycosides at room temperature.
The use of alkyl glycosides for surfactant purposes has been described in several patents and papers (e.g. U.S. Pat. No. 9,908,517, WO 0190286). Suitable applications cover the use as detergent for cleaning purposes (e.g. U.S. Pat. No. 5,858,954, MY 106677) as well as additives for e.g. cosmetic formulations (e.g. WO 9406408, U.S. Pat. No. 5,605,651, JP 9173822). A related example for usage in vesicles may be found in German Patent DE 1963437. Commonly alkyl glycosides (also named APGs, or alkyl polyglycosides) contain only one single alkyl chain. This way they differ from natural lipids, which exhibit a double chain structure, involving a polar head-group and two non-polar chains. These structures, showing special physical characteristics generally believed to be responsible for the properties of biological membranes, cannot be mimicked by simple APGs.
For biophysical studies, therefore, more complex compounds, like glycoglycerolipids, are needed. Due to immense problems involved in lipid purification, generally synthetic compounds are favored over natural derived material. The number of chemical transformations involved and the extensive purification, however, make this approach expensive and limits future applications. A major obstacle is based on the limited chemical stability of the ester groups present in glycoglycerolipids. These add to both purification requirements and the number of chemical steps. While syntheses for ether analog structures have been published (e.g. H. Minamikawa et al., Chem. Phys. Lipids, 1994, 72, 111-118), improving the accessibility of materials, a more easy access to model compounds remains desirable. The present invention provides such a possibility.
Branched chain (guebert type) alcohol derived esters have been applied as emulsifiers before, showing superior emulsification and better liquidity (e.g. U.S. Pat. Nos. 5,717,119, 5,736,571, 6,013,813). The effect of branching on alcohols bond in glycosides, however, has not been investigated before.
Synthetic glycolipids exhibit a large spectrum of useful applications such as coating a drug to keep it from early destruction, stabilization of hydrocarbon foam, primary solvents for tropical medication, mild soap for delicate fields of application or the synthesis of nanostructure materials. Prior art Japanese Patent JP 11244608 even disclosed the usage of glycolipid derivatives as antifoaming additives for resin manufacturing, dyeing and wastewater treatment.
The objective of the invention is to provide new glycolipids showing special liquid crystal properties with respect to thermotropic and lyotropic behavior. Possible applications of these glycolipids involve:
low temperature liquid crystals, e.g. for optical switches and other applications artificial membranes drug coating and related pharmaceutical applications (e.g. vesicles) surfactant and micelle applications in cosmetics, detergency and nanotechnology antifoaming surfactants for process- and wastewater treatments
SUMMARY OF THE INVENTION
The inventors have investigated the liquid crystalline properties of branched chain alkyl oligosaccharides with the intention of providing novel easy accessible synthetic glycolipids suitable for model studies on membranes.
During this investigation it turned out, that the synthetic glycolipids show particular interesting liquid crystalline properties with respect to both thermotropic and lyotropic behavior, not being found for previously know straight chain alkyl saccharides. Features involve ambient temperature liquid crystalline appearance and thermotropic polymorphism, including observation of cubic phases. The latter are considered particularly interesting with respect to life science applications like e.g. liposomes for drug delivery.
Beside their unusual thermotropic liquid crystalline behavior, glycolipids of branched chain oligosaccharides also exhibit mesophases in aqueous environment, demonstrating their surfactant abilities. The close structural relationship towards natural glycoglycerolipids combined with their increased chemical resistance make them interesting subjects for pharmaceutical applications.
Based on accessibility and costs, the focus is set on nature derived reducing oligosaccharides. These especially involve but do not limit to malto-, cello-, chito- and xyloologomers as well as lactose, isomaltose, gentio- and meliobiose.
The glycolipids of the present invention may be summarized in Formula I, where
A=H, CH 2 Y, CH 3 , CO 2 R*, CO 2 M, COSR*, CSOR*, CONR*R**, C 2 H 4 X, CH 2 CO 2 R*, CH 2 COSR*, or CH 2 CONR*R**; L=H, sugar or acetylated sugar; M=cation; R 3 ═H, Ac, or H(C 2 H 4 O) x or W(C 2 H 4 O) x ; R 3 ═H, Ac, or H(C 2 H 4 O) x or W(C 2 H 4 O) x ; W═OH, NH 2 , NHC(═W*)R*, NHC(═W*)Y*R*, or O(C 2 H 4 O) x R*; Y═W, Cl, Br, F, N 3 , or CN; R*, R**=(substituted) alkyl, aryl, or H; W*, Y*═O, S, or NR**; X is an integer of 1 to 100; n, m≧2 and m≠n; d, d′=1, −1.
In another embodiment of the present invention, glycolipids of branched chain alkyl oligosaccharides show structures according to Formula II, where
A=CH 2 Y, CH 2 OL, CH 3 , CO 2 R*, CO 2 M, COSR*, CSOR*, CONR*R**, C 2 H 4 W,
CH 2 CO 2 R*, CH 2 COSR*, or CH 2 CONR*R**;
L=sugar, or acetylated sugar; M=cation; R 2 ═H, Ac, or H(C 2 H 4 O) x or W(C 2 H 4 O) x ; R 2 ═H, Ac, or H(C 2 H 4 O) x or W(C 2 H 4 O) x ; R 3 ═H, Ac, or H(C 2 H 4 O) x or W(C 2 H 4 O) x ; R 3 ═H, Ac, or H(C 2 H 4 O) x or W(C 2 H 4 O) x ; R 4 ═H, Ac, or H(C 2 H 4 O) x or W(C 2 H 4 O) x ; R 4 ═H, Ac, or H(C 2 H 4 O) x or W(C 2 H 4 O) x ; W═OH, NH 2 , NHC(═W*)R*, NHC(═W*)Y*R*, or O(C 2 H 4 O) x R*); Y═W, Cl, Br, F, N 3 , or CN; R*, R**=(substituted) alkyl, aryl, or H; W*, Y*═O, S, or NR**; X is an integer of 1 to 100; n, m≧2 and m≠n d, d′=1, −1.
The further subject of the present investigation is focused on the use of the glycolipids described before and their patterns of self assembly for pharmaceutical, cosmetic or other applications, especially with respect to the life science sector.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the branched chain glycolipid containing a (1,4)-linked saccharide.
FIG. 2 shows the branched chain glycolipid containing a (1,6)-linked saccharide.
FIG. 3 shows the core structure of a natural glycoglycerolipid.
FIG. 4 shows the synthesis route for branched chain alkyl α- and β-oligosaccharides, exemplified for a maltosides.
FIG. 5 shows the derivatization of branched chain glycolipids, of (1,4)-linked disaccharides.
FIG. 6 shows a DSC recording for a branched chain alkyl maltoside.
DETAILED DESCRIPTION OF THE INVENTION
Several branched chain alkyl oligosaccharides show ambient temperature liquid crystalline behavior. While common alkyl glycosides generally exhibit exclusively smectic phases, more complex phase diagrams can be observed for branched alkyl glycosides. Thus smectic, columnar and even liquid crystal phase polymorphism involving bicontinuous cubic phases may be found. The liquid crystal—liquid crystal phase transitions may give rise to some new applications of the compounds.
Branched alkyl glycosides are almost isosteric to natural glycoglycerolipids (see FIG. 3 ). Thus the branched alkyl oligosaccharides provide interesting candidates for new biotechnology applications as well as pharmaceutical applications. Based on their complex phase behavior, they may also exhibit superior properties for cosmetic formulations as e.g. creams.
The preparation of the compounds comprises a 3-step-synthesis starting from commercial available nature derived oligosaccharides following literature known procedures (e.g. V. Vill et al., Liq. Cryst., 1989, 6, 349-356; FIG. 4 ). Derivatization ( FIG. 5 ) of these products provide access to an even greater variety, which may be further improved taking advantage of amino or carboxyl-groups. The full range of structures available through this process is displayed in FIG. 2 .
The thermotropic phase behavior of branched chain alkyl oligosaccharides involve a change of liquid crystal phases found for a specific sugar head group from singly smectic, over liquid crystal polymorphism, towards a singly columnar liquid crystal mesophase with increasing size of alkyl chain. Most interesting among this is the appearance of bicontinous cubic phases separating the smectic and the columnar structures. Cubic phases are believed to play an essential role in cell-exchange processes. All processes involving endo- and exocytosis pass through a cubic state of the membrane. Cubic phases of membrane like material, therefore, are considered interesting with respect to possible life science applications. Cubic phases for branched chain alkyl oligosaccharides may be observed over a broad range of temperature. Experiments also indicate the presence of two different cubic phases for at least one of the compounds.
The lyotropic liquid crystal behavior in aqueous systems conforms the compounds' ability to act as structure forming surfactants. The thermal stability of the supramolecular structures formed depends on the length of the alkyl chain of the glycolipid. For some compounds textures be maintained over a broad temperature range, starting below room temperature and exceeding 80° C. The water miscibility of branched chain alkyl oligosaccharides for a given sugar head varies largely, depending highly on the length of the alkyl tails. Based on the applications requirements, either full water solubility (e.g. for emulsion applications) or mere slight water swelling of the glycolipids (e.g. for the formation of artificial membranes, since rearrangement of the material or even dissolving is to be avoided in that case) may be achieved.
In another embodiment, glycolipids of branched chain alkyl oligosaccharides of the present invention, or mixtures containing one or more of them, may be used in thermotropic liquid crystal applications, cosmetical applications, vesicles or liposomes preparation, especially for drug delivery, pharmaceutical emulsions, pharmaceutical applications, where the role of the compound is either protection, time release or direction of a drug or diagnostic sensor, lyotropic liquid crystal applications, especially for the preparation of artificial membranes, nanostructure templating, as antifoaming additives for process- or wastewater treatments, surfactant or any other suitable applications known in the art. The use of glycolipids for drug delivery system in the present invention aims to enhance permeability of the drug delivery system into the cells across the cell membrane rather than contributing as a specific antigen, which is used for targeting in receptor recognitions found in common drug delivery system.
The following examples are included herein solely as an illustrative aid to provide a more complete understanding of the present invention and the product formed thereby. The examples do not limit the scope of the present invention disclosed and claimed herein in any fashion.
EXAMPLES
General Synthesis of β-Glycosides (Amounts Based on Branched C 24 Disaccharide Glycosides)
A solution of 3.4 g β-peracetate and 2.3 g 2-decyl-tetradecanol in 50 mL anhydrous dichloromethane was treated with 600 μL borontrifluoride dimethyletherate and kept at room temperature for about 5-48 h. The mixture was washed with aqueous sodium bicarbonate and dried over magnesium sulfate. After evaporation of the solvent, the acetylated glycolipid was purified by chromatography (hexane/ethyl acetate). The intermediate product was dissolved in 30-40 mL methanol and treated with a catalytic amount of sodium methoxide. After 30-60 min the catalyst was removed by treatment with amberlite IR 120 (H + ) and the solvent was evaporated. Further purification of the anomer by chromatography on ion exchanging resin generally proofed to be unnecessary.
General Synthesis of α-Glycosides (Amounts Based on Branched C 24 Disaccharide Glycosides)
A solution of 3.4 g β-peracetate and 2.7 g 2-decyl-tetradecanol in 50 mL anhydrous dichloromethane was treated with 600 μL tin tetrachloride and kept at room temperature for about 2-3 d. The reaction mixture was filtered through moistened celite, then washed with aqueous sodium bicarbonate and dried over magnesium sulfate. After evaporation of the solvent, the acetylated glycolipid was purified by chromatography (hexane/ethyl acetate). The intermediate product was dissolved in 30-100 mL methanol and treated with a catalytic amount of sodium methoxide. After ½-3 h the catalyst was removed by treatment with amberlite IR 120 (H + ) and the solvent was evaporated. Further purification of the anomer by chromatography on ion exchanging resin was generally not required.
Example 1
2-Hexyl-decyl-α-meliobioside
Yield: 28%; Cr ? 5 mA 170° C. Dec
1 H-NMR (300 MHz, CDCl 3 , peracetate): δ 5.45 (dd, H-3; 10.0 Hz, 9.5 Hz), 5.44 (dd, H-4′; 3.0 Hz, 1.0 Hz), 5.31 (dd, H-3′; 10.5 Hz, 3.0 Hz), 5.18 (d, H-1; 3.5 Hz), 5.09 (dd, H-2′; 3.5 Hz, 10.5 Hz), 5.04 (dd, H-4; 9.5 Hz, 10.0 Hz), 4.97 (d, H-1′; 3.5 Hz), 4.76 (dd, H-2; 3.5 Hz, 10.0 Hz), 4.22 (ddd, H-5′; 1.0 Hz, 7.0 Hz, 6.5 Hz), 4.09 (dd, H-6′ a; 6.5 Hz, 11.0 Hz); 4.03 (dd, H-6′b; 7.0 Hz, 11.0 Hz), 3.93 (ddd, H-5; 10.0 Hz, 5.0 Hz, 2.5 Hz), 3.70 (dd, H-6a; 5.0 Hz, 11.5 Hz), 3.60 (2 dd, α-H, 9.5 Hz, 6.0 Hz); 3.53 (dd, H-6b; 2.5 Hz, 11.5 Hz), 3.22 (dd, α′-H, 9.5 Hz, 6.0 Hz), 2.12 (s, 3 H, Ac), 2.11 (s, 3 H, Ac), 2.04 (s, 3 H, Ac), 2.03 (s, 6H, 2 Ac), 2.00 (s, 3H, Ac), 1.96 (s, 3H, Ac), 1.57 (m c , β-H), 1.36-1.17 (m, 24H, CH 2 ), 0.87 (2 t, 6H, CH 3 ) ppm.
Example 2
2-Octyl-dodecyl β3-maltoside
Yield: 35%; Cr 19° C. 5 mA 115° C. Cub 192° C. Col 210° C. I
1 H-NMR (400 MHz, CDCl 3 , peracetate): δ 5.34 (d, H-1′; 4.0 Hz), 5.29 (dd, H-3′; 10.0 Hz, 10.0 Hz), 5.18 (dd, H-3; 9.0 Hz, 9.0 Hz), 4.98 (dd, H-4′; 10.0 Hz, 10.0 Hz), 4.79 (dd, H-2′; 4.0 Hz, 10.0 Hz), 4.75 (dd, H-2; 8.0 Hz, 9.5 Hz), 4.41 (2 d, H-1; 8.0 Hz), 4.39 (dd, H-6a; 3.0 Hz, 12.0 Hz), 4.18 (dd, H-6′a; 4.0 Hz, 12.0 Hz), 4.17 (dd, H-6b; 4.5 Hz, 12.0 Hz), 3.97 (dd, H-6′b; 2.5 Hz, 12.0 Hz), 3.93 (dd, H-4; 9.0 Hz, 9.5 Hz), 3.90 (ddd, H-5′; 10.0 Hz, 4.0 Hz, 2.5 Hz), 3.71 (dd, α-H, 9.5 Hz, 5.5 Hz), 3.59 (ddd, H-5; 9.5 Hz, 3.0 Hz, 4.5 Hz), 3.22 (dd, α-H′; 9.5 Hz, 6.5 Hz), 2.07 (s, 3H, Ac), 2.03 (s, 3H, Ac), 1.97 (s, 3H, Ac), 1.95 (s, 3H, Ac), 1.93 (s, 9H, 3 Ac), 1.47 (m, β-H), 1.29-1.11 (m, 32H, CH 2 ), 0.81 (2 t, 6H, CH 3 ) ppm.
Example 3
2-Decyl-tetradecyl β-maltoside
Yield: 40%; Cr 19° C. 5 mA 73° C. Cub 131° C. Col 225° C. I
Example 4
2-Ethyl-hexyl α-maltoside
Yield: 21%; Cr 74° C. I
1 H-NMR (300 MHz, CDCl 3 , peracetate): δ 5.50 (dd, H-3; 10.0 Hz, 8.5 Hz), 5.38 (d, H-1′; 4.0 Hz), 5.36 (dd, H-3′; 10.5 Hz, 9.5 Hz), 5.04 (dd, H-4′; 9.5 Hz, 10.0 Hz), 4.92 (H-1; 4.0 Hz), 4.85 (dd, H-2′; 4.0 Hz, 10.5 Hz), 4.70 (2 dd, H-2; 4.0 Hz, 10.0 Hz), 4.43 (dd, H-6*; 2 Hz, 12 Hz), 4.23 (dd, H-6*; 4 Hz, 12 Hz), 4.22 (dd, H-6*; 3.5 Hz, 12 Hz), 4.03 (dd, H-6*; 2 Hz, 12 Hz), 4.00-3.89 (m, 3 H, H-4, H-5, H-5′), 3.61/3.60 (2 dd, α-H, 9.5 Hz, 6.5 Hz), 3.24/3.22 (2 dd, α-H′; 9.5 Hz, 6.0 Hz), 2.12 (s, 3H, Ac), 2.08 (s, 3H, Ac), 2.05 (s, 3H, Ac), 2.02 (s, 3H, Ac), 2.01 (s, 3H, Ac), 1.99 (s, 6H, 2 Ac), 1.55 (m c , β-H), 1.44-1.18 (m, 8H, CH 2 ), 0.91-0.84 (m c , 6H, CH 3 ) ppm.
Example 5
2-Hexyl-decyl α-maltoside
Yield: 18%; Cr 123° C. 5 mA 224° C. Dec
Example 6
2-Hexyl-decyl β-cellobioside
Yield: 38%; Cr ? 5 mA 189° C. dec
1 H-NMR (400 MHz, CDCl 3 , peracetate): δ 5.17 (dd, H-3*; 10.0 Hz, 9.5 Hz), 5.12 (dd, H-3*; 10.0 Hz, 9.5 Hz), 5.04 (dd, H-4′; 9.5 Hz, 10.0 Hz), 4.89 (dd, H-2*; 8.0 Hz, 10.0 Hz), 4.87 (dd, H-2*; 8.0 Hz, 10.0 Hz), 4.49 (d, H-1*; 8.0 Hz), 4.48 (dd, H-6a*; 2.0 Hz, 12.0 Hz), 4.39 (d, H-11; 8.0 Hz), 4.34 (dd, H-6a*; 4.5 Hz, 12.5 Hz), 4.07 (dd, H-6b*; 5.0 Hz, 12.0 Hz), 4.03 (dd, H-6b*; 2.0 Hz, 12.5 Hz), 3.75 (dd, H-4; 10.0 Hz, 10.0 Hz), 3.73 (dd, α-H, 9.5 Hz, 6.0 Hz), 3.64 (ddd, H-5*; 10.0 Hz, 2.0 Hz, 4.5 Hz), 3.55 (ddd, H-5*; 10.0 Hz, 2.0 Hz, 5.0 Hz), 3.25 (dd, α′-H, 9.5 Hz, 6.0 Hz), 2.11 (s, 3H, Ac), 2.08 (s, 3H, Ac), 2.01 (s, 3H, Ac), 2.00 (s, 6H, 2 Ac), 1.99 (s, 3H, Ac), 1.96 (s, 3H, Ac), 1.50 (m c , β-H), 1.30-1.18 (m, 16H, CH 2 ), 0.86 (m c , 6H, CH 3 ) ppm.
Example 7
2-Decyl-tetradecyl β-lactoside
Yield: 26%; Cr 117° C. Col 235° C. I
1 H-NMR (400 MHz, CDCl 3 , peracetate): δ 5.31 (bd, H-4′; 3.5 Hz, <1 Hz), 5.16 (dd, H-3; 9.5 Hz, 9.5 Hz), 5.07 (dd, H-2′; 8.0 Hz, 10.5 Hz), 4.91 (dd, H-3′; 10.5 Hz, 3.5 Hz), 4.86 (dd, H-2; 8.0 Hz, 9.5 Hz), 4.44 (d, H-11; 8.0 Hz), 4.44 (m c , H-6*), 4.38 (d, H-11; 8.0 Hz), 4.12-4.01 (m, 3H, H-6*), 3.83 (bdd, H-5′; <1 Hz, 7 Hz, 7 Hz), 3.76 (dd, H-4; 9.5 Hz, 9.5 Hz), 3.55 (m c , H-5), 3.72 (dd, α-H, 9.5 Hz, 5.0 Hz), 3.23 (dd, α′-H, 9.5 Hz, 5.0 Hz), 2.12 (Int 3, s, Ac), 2.08 (s, 3H, Ac), 2.03 (s, 3H, Ac), 2.01 (s, 6H, 2 Ac), 1.98 (s, 3H, Ac), 1.93 (s, 3H, Ac), 1.58 (m c , β-H), 1.30-1.16 (m, 40H, CH 2 ), 0.84 (t, 6H, CH 3 ) ppm.
Example 8
2-Decyl-tetradecyl β-lactoside
Yield: 5% (+20% a/3-mixture ˜5:3)
Cr 93° C. 5 mA 142° C. Cub 164° C. Col 182° C. I
1 H-NMR (270 MHz, CDCl 3 , 3,6,2′,3′,4′,6′-hexaacetate): δ 5.34 (bd, H-4′; 3.0 Hz), 5.19 (dd, H-3; 10.0 Hz, 9.5 Hz), 5.12 (dd, H-2′; 8.0 Hz, 10.5 Hz), 4.95 (dd, H-3′; 10.5 Hz, 3.0 Hz), 4.80 (d, H-1; 4.0 Hz), 4.49 (d, H-1′; 8.0 Hz), 4.40 (dd, H-6*a; 2.0 Hz, 12.0 Hz), 4.21-4.02 (m, 3H, 3 H-6*), 3.87 (bdd, H-5′; 7 Hz, 7 Hz), 3.84 (m c , H-5), 3.65 (dd, H-4; 9.5 Hz, 9.5 Hz), 3.62 (dd, α-H, 9.5 Hz, 6.0 Hz), 3.54 (dd, H-2; 10.0 Hz, 4.0 Hz), 3.30 (dd, α′-H; 9.5 Hz, 6.0 Hz), 2.15 (s, 3H, Ac), 2.12 (s, 3H, Ac), 2.11 (s, 3H, Ac), 2.05 (s, 3H, Ac), 2.04 (s, 3H, Ac), 1.96 (s, 3H, Ac), 1.60 (mc, β-H), 1.40-1.15 (m, 40H, CH 2 ), 0.87 (t, 6H, CH 3 ) ppm.
It is to be understood that the present invention may be embodied in other specific forms and is not limited to the sole embodiment described above. However modification and equivalents of the disclosed concepts such as those which readily occur to one skilled in the art are intended to be included within the scope of the claims which are appended thereto.
|
Glycolipids of branched chain alkyl oligosaccharides according to this patent comprise of a primary alcohol branched in the 2-position and an oligosaccharide, covalently bond to the alcohol in either α- or β-linkage (shown in Formula I and Formula II). These compounds show particularly interesting phase behavior not found for the corresponding straight chain counterparts. The properties involve an ambient temperature liquid crystalline appearance and thermotropic liquid crystal phase polymorphism. Upon the latter, the formation of cubic phases is considered most interesting with respect to life science applications, e.g. liposome for drug delivery. Depending on the choice of sugar head group and alkyl tail, various levels of water miscibility may be adjusted to meet applications requirements (complete solubility for emulsifier applications, e.g. cosmetic creams, to limited water swelling only, e.g. for the preparation of artificial membranes). The closed structural relationship to natural lipids also make branched chain alkyl oligosaccharides valuable subjects for biochemical investigations, e.g. membrane studies. The range of possible applications for glycolipids of branched chain alkyl oligosaccharides involve material science liquid crystal applications, e.g, optical switches, as well as surfactants and the life science applications.
| 2
|
FIELD OF THE INVENTION
This invention relates to engine-driven electrical generators, and more particularly to a fuel tank for such generators.
BACKGROUND OF THE INVENTION
Electrical generators are commonly used to provide electrical power in situations where conventional wired electrical power grid sources are not available, such as during a power outage, at construction sites, or at remote locations. The generator may use an engine to drive the generator. The generator may include a fuel tank to store gasoline and provide fuel for the engine. Some prior art generators include fuel tanks that are mounted to the generator.
When refilling the fuel tank, the operator may take the entire generator to a gasoline station, or a separate gasoline container may be used to transport fuel to the generator. Generators are typically heavy and cumbersome, and transporting the entire generator for a refill is typically not practical. Separate gasoline containers are additional items for an operator to obtain and have available when a refill is necessary. Separate gasoline containers may be easily misplaced and may require additional storage space.
Also, the operator may have to maintain each separate gasoline container full of gasoline. It may be desirable for an operator to have a reserve supply of gasoline stored in separate gasoline containers for extended use of the generator. In this situation, the operator may have to make a first trip to the gasoline station with separate gasoline containers to obtain gasoline for filling the generator fuel tank, and a second trip to refill the separate gasoline containers to maintain a reserve supply of gasoline.
Some separate gasoline containers may have a capacity that is less than the capacity of the generator fuel tank. For example, some generator fuel tanks have a capacity of 5 gallons, and may have a capacity of 10 gallons or more. A typical separate gasoline container may have a capacity of 2.5 gallons. Therefore, multiple gasoline containers or multiple trips to a gasoline station may be needed to refill the generator.
Also, generators are often needed during power outages. Separate gasoline containers may become relatively scarce during a power outage when demand for backup power increases. A shortage of gasoline containers during a power outage may require an operator to have multiple containers or make multiple trips to a gasoline station to maintain a supply of fuel for the generator. The separate gasoline containers also requires extra storage space, and may not be readily available when needed.
SUMMARY OF THE INVENTION
A generator embodying the invention comprises a removable fuel tank that is easily accessible and may be easily removed from the generator. The exposed, easily accessible, removable fuel tank provides a convenience for the operator because the removable fuel tank may be taken to a gasoline station for refilling, and reattached to the generator for operation. The removable fuel tank is readily available and is less likely to be lost than a separate gasoline container. Additionally, the removable fuel tank does not require additional storage space when not in use.
The generator includes a frame that supports an engine and the fuel tank. The engine powers the generator, and the fuel tank stores gasoline for the engine. The fuel tank is removably interconnected to the frame with quick release fasteners. The quick release fasteners may retain the fuel tank to the frame, and may hold the fuel tank and frame from substantially moving with respect to each other. Preferably, the quick release fasteners may be disengaged by hand without the use of additional tooling. A fuel line between the fuel tank and the engine may include a quick disconnect attachment that may shut off fuel flow and easily detach the fuel tank from the engine.
In the preferred embodiment, the quick release fastener includes a threaded fastener, such as bolt or screw, and may include a handle to facilitate engaging or disengaging the fastener by hand. The fuel tank may include a clamping portion, and the bolt may extend through a slot in the clamping portion and engage the frame. The bolt may include a disc-shaped flange that clamps the clamping portion to the frame. Alternatively, the quick release fastener may include other fasteners, such as clamps, pivoting tabs, key locks, elastic members, pins, latches, or other similar fasteners. Preferably, the quick release fasteners may be engaged by hand, and do not require a tool.
The fuel tank may be openly exposed near the top of the generator to provide easy access when refilling the fuel tank, and when detaching or reattaching the fuel tank. The fuel tank is preferably not enclosed within a housing. The fuel tank is readily available, and the operator does not have to locate a separate gasoline container when the generator requires refueling. The entire removable fuel tank may be refilled without the need for multiple gasoline containers or multiple trips to the gasoline station.
Additionally, it may be desirable to maintain a reserve fuel supply for operating the generator for extended periods of time. The operator may make a single trip to the gasoline station to refill the removable fuel tank and separate gasoline containers. With some prior art generators, separate trips to the gasoline station with separate gasoline containers were needed to first obtain gasoline for refilling the generator, and then refill the separate gasoline containers again for a reserve supply of gasoline. With the removable fuel tank, an operator may refill the generator, and refill separate gasoline containers for a reserve fuel supply in a single trip to the gasoline station. Therefore, the removable fuel tank may be particularly useful for initial filling of the fuel tank, and may help an operator to maximize a reserve gasoline supply while minimizing trips to the gasoline station.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a generator having a removable fuel tank, according to the present invention.
FIG. 2 is an enlarged view of a quick-disconnect fuel line on the generator of FIG. 1 .
FIG. 3 is an exploded view of the fuel tank on the generator of FIG. 1 .
FIG. 4 is a cross sectional view taken along line 4 — 4 of FIG. 1 .
FIG. 5 is a perspective view of the fuel tank removed from the generator of FIG. 1 .
FIG. 6 is an alternate embodiment of a quick release fastener for retaining the fuel tank to the generator.
FIG. 7 is an alternate embodiment of a quick release fastener for retaining the fuel tank to the generator.
FIG. 8 is an alternate embodiment of a quick release fastener for retaining the fuel tank to the generator.
Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
Although references are made below to directions, such as left, right, up, down, top, bottom, front, rear, back etc., in describing the drawings, they are made relative to the drawings (as normally viewed) for convenience. These directions are not intended to be taken literally or limit the present invention in any form.
DETAILED DESCRIPTION
FIG. 1 illustrates a portable generator 10 having a removable fuel tank 14 . The generator 10 includes a frame 18 having a base 22 , a support portion 26 disposed above the base 22 , and a frame handle 30 projecting outwardly from the frame 18 . The frame handle 30 may be movable to reduce the height of the generator 10 for storage or transport. Wheels 34 are interconnected to the frame 18 near the base 22 to facilitate transporting the generator 10 . Stops 38 are also connected to the frame 18 near the base 22 to help provide stability while the generator 10 is stationary. FIG. 1 illustrates a portable generator 10 having wheels 34 , but the removable fuel tank 14 may also be used with a stationary generator. The removable fuel tank 14 may be beneficial for a stationary generator since the entire stationary generator cannot be transported to refill the fuel tank 14 .
An engine 42 is connected to the frame 18 and supported by the base 22 . The engine 42 is generally disposed between the base 22 and the support portion 26 . In the illustrated embodiment, the engine 42 is an approximately 10 HP engine, and the fuel tank 14 stores fuel for the engine 42 . The fuel tank 14 is disposed above engine 42 , and is openly exposed near the top of the generator 10 to provide easy access to the fuel tank 14 . The generator 10 includes a gen-set 46 that generally convert mechanical power from the engine 42 into electrical current. The gen-set 46 may provide AC or DC current, and may include, among other things, a rotor, stator, or alternator.
As shown in FIG. 1, the generator 10 includes a control panel 50 , having several electrical outlets. Various tools or appliances may be plugged into the control panel 50 , and the generator 10 may provide power for the tools or appliances. In the preferred embodiment, the generator 10 provides an AC current of 105-125 Volts (V), 50-60 Hertz (Hz), and 20 Amps (A) through a conventional outlet in the control panel 50 . Alternatively, the generator 10 may include a 120V-15A outlet, a 120V-30A locking type outlet, a 120/240V-20A locking type outlet, a 120/240V-30A locking type outlet, a 12V DC current outlet, or other similar outlets known to one skilled in the art.
The fuel tank 14 is removably interconnected to the frame 18 near the support portion 26 . A quick release fastener 54 retains the fuel tank 14 to the frame 18 . In the illustrated embodiment, the fuel tank 14 may have a capacity of approximately 5 gallons or more. The fuel tank 14 may be formed from a plastic material, or another similar substantially rigid material that is resistant to gasoline. The fuel tank 14 has a first face 58 that is substantially rectangular, a second face 62 , and a wall 66 extending between the first face 58 and the second face 62 . The first face 58 faces away from the engine 42 , and the second face 62 faces toward the engine 42 .
The wall 66 has a first end 70 and a second end 74 disposed opposite one another. The wall 66 also includes a first side 78 and a second side 82 disposed opposite one another, and adjacent the first end 70 and second end 74 . In the illustrated embodiment, the first end 70 is located near the frame handle 30 , and includes a C-shaped tank handle 86 . The second end 74 is disposed opposite the first end 70 near the control panel 50 , and includes a ridge 88 that extends inwardly from the second end 74 . The tank handle 86 and ridge 88 facilitate carrying the fuel tank 14 when the fuel tank 14 is removed from the frame 18 .
The fuel tank 14 includes a fuel opening 90 for refilling the fuel tank 14 . In FIG. 1, the fuel opening 90 is located in the first face 58 near the top of the generator 10 . The first face 58 and the fuel opening 90 are exposed near the top of the generator 10 to make the fuel opening 90 easily accessible. A fuel cap 92 may detachably engage the fuel opening 90 to enclose the fuel opening 90 . In the illustrated embodiment, the fuel cap 92 may be threaded on and off of the fuel opening 90 . The fuel cap 92 may include a vent 94 to release pressure within the fuel tank 14 . Vapors within the fuel tank 14 may expand when the fuel tank 14 is sealed, and actuating the vent 94 to release pressure may help prevent removing the fuel cap 92 while the contents of the fuel tank 14 are under pressure.
The fuel tank 14 includes a clamping portion 96 , and the frame 18 includes a retaining surface 98 . In the illustrated embodiment, the support portion 26 includes elongated rods 102 , and the retaining surface 98 is located near the top of the elongated rods 102 . The clamping portion 96 is located adjacent the sides 78 , 82 of the fuel tank 14 . The retaining surface 98 is adjacent the clamping portion 96 when the fuel tank 14 is interconnected to the frame 18 , and the retaining surface 98 may contact the clamping portion 96 . The clamping portion 96 may be incorporated into an edge 106 extending along the sides 78 , 82 of the fuel tank 14 , and the fuel tank 14 may extend outwardly beyond the elongated rods 102 . The quick release fastener 54 holds the retaining surface 98 and clamping portion 96 from substantially moving with respect to each other.
The fuel tank 14 may include a recess 110 in the sides 78 , 82 that extends inwardly toward the fuel tank 14 . As shown in FIG. 1, two recesses 110 extend into each side 78 , 82 . The clamping portion 96 may be at least partially disposed within the recess 110 . A slot 114 extends into the clamping portion 96 within the recess 110 . The quick release fastener 54 extends through the slot 114 and engages the frame 18 to retain the fuel tank 14 to the frame 18 .
FIG. 3 illustrates the fuel tank 14 removed from the frame 18 . In the illustrated embodiment, the quick release fasteners 54 are bolts 118 having a threaded end 122 and a head 126 opposite the threaded end 122 . A disc-shaped flange 130 projects radially outwardly from the bolt 118 adjacent the threaded end 122 . The head 126 includes a wing handle 134 to facilitate tightening and loosening the bolt 118 by hand. In FIG. 3, the fuel tank 14 includes four bolts 118 , one for each recess 110 . The recesses 110 provide clearance to rotate and thread the bolts 118 into position, and reduce the overall height of the fuel tank frame assembly. The recesses 110 and bolts 118 are preferably located near the corners of the fuel tank 14 to evenly distribute support for the fuel tank 14 . In the illustrated embodiment, the fuel tank 14 also includes an indentation 138 in the first side 78 between the other recesses 110 . The indentation 138 may provide access to the engine 42 for maintenance purposes, such as checking and refilling oil in the engine 42 .
The bolts 118 threadedly engage the support portion 26 to retain the fuel tank 14 to the frame 18 . As shown in FIG. 3, the support portion 26 includes elongated rods 102 , and the retaining surface 98 is disposed near the top of the elongated rods 102 . In the illustrated embodiment, apertures 142 extend into the elongated rods 102 . The apertures 142 are aligned with the slots 114 , and the bolts 118 extend through the slots 114 and into the apertures 142 . In FIG. 4, inserts 146 are disposed within the apertures 142 , and have a threaded inner surface 150 . The threaded end 122 of the bolt 118 engages the inner surface 150 of the insert 146 . An air gun having a threaded attachment that engages the insert's threads is used to form flanges on the inserts 146 . Alternatively, the threaded end 122 of the bolt 118 may directly engage the support portion 26 .
The wing handle 134 permits the bolt 118 to be easily threaded in or out of the apertures 142 . Preferably, the bolt 118 may be threaded by hand, and no additional tools are needed to insert or remove the bolt 118 . As shown in FIG. 4, the clamping portion 96 is clamped between the disc flange 130 and the elongated rod 102 when the bolt 118 is tightened. The bolt 118 retains the fuel tank 14 to the frame 18 , and holds the retaining surface 98 and clamping portion 96 from substantially moving with respect to each other.
As shown in FIG. 3 and mentioned above, the fuel tank 14 includes the ridge 88 near the first end 70 and the tank handle 86 near the second end 74 . The ridge 88 and tank handle 86 provide surfaces for an operator to grip while removing the fuel tank 14 from the frame 18 . The fuel tank 14 may be removed from the frame 18 after the quick release fasteners 54 are disengaged.
In FIG. 2, a fuel line 154 is connected to the fuel tank 14 and carries fuel from the fuel tank 14 to the engine 42 (FIG. 1 ). The fuel line 154 may include a shut-off valve 158 and a quick disconnect 162 . The shut-off valve 158 may be actuated to stop fuel flow. Once the fuel flow is stopped, the quick disconnect 162 may be disengaged to disconnect the fuel line 154 , and the fuel tank 14 may be removed from the frame 18 .
In the illustrated embodiment, the quick disconnect 162 includes a plug 166 that may be inserted into a receptacle 170 . The receptacle 170 may include a biased clamp 178 that clamps the plug 166 in an engaged position. The plug 166 may include an O-ring or gasket to help seal the fuel line 154 . The biased clamp 178 may be actuated against the bias to unclamp the plug 166 . Once the plug 166 is unclamped, the plug 166 may be detached from the receptacle 170 and moved to a disengaged position. In FIG. 2, the solid lines illustrate the plug 166 in the engaged position, and the broken lines illustrate the plug 166 in the disengaged position.
The fuel tank 14 may be removed from the frame 18 when the quick release fasteners 54 are disengaged, the shut-off valve 158 stops fuel flow, and the quick disconnect 162 of the fuel line 154 is disconnected. As mentioned above and illustrated in FIG. 3, the tank handles 86 and ridge 88 facilitate lifting the fuel tank 14 and removing the fuel tank 14 from the frame 18 .
FIG. 5 illustrates an operator holding the tank handle 86 and carrying the fuel tank 14 . FIG. 5 also illustrates the second face 62 having a rib 182 integrally formed with the fuel tank 14 . As mentioned above, the fuel tank 14 may be formed from a plastic material, and the rib 182 may help provide strength and stability for the fuel tank 14 . In the illustrated embodiment, the rib 182 projects outwardly from the fuel tank 14 and extends in a V-shape along the second face 62 . The rib 182 may also extend from the V-shape towards the tank handle 86 along the second face 62 for additional stability. FIG. 5 also illustrates the shut-off valve 158 and receptacle 170 of the fuel line 154 interconnected to the second end 74 of the fuel tank 14 .
Since the fuel tank 14 is removable, the fuel tank 14 may be transported separately from the generator 10 . In some prior art generators, a separate gasoline container may be needed to transport fuel from a gas station to the generator and refill the fuel tank. With this prior art arrangement, gasoline is transferred from the gas pump at the gasoline station to the separate gasoline container, and then transferred from the separate gasoline container to the generator. Each transfer or pour between containers provides an additional risk of spilling the gasoline. The separate gasoline container also requires extra storage space, and may not be readily available when needed.
As shown in FIGS. 1, 3 and 4 , the quick release fastener 54 includes the bolt 118 . Other embodiments of the quick release fastener 54 may also be used to retain the fuel tank 14 to the frame 18 . As shown in FIG. 6, the quick release fastener 54 includes a relatively flat tab 210 that retains the fuel tank 14 to the frame 18 . The tab 210 is pivotally connected to the frame 18 and projects outwardly from the support portion 26 . The tab 210 is connected to the support portion 26 , and may pivot with respect to the frame 18 to engage or disengage the fuel tank 14 . The fuel tank 14 includes at least one recess 110 that extends inwardly toward the fuel tank 14 . A clamping portion 218 is at least partially disposed within the recess 110 , and a slot 222 extends into the clamping portion 218 within the recess 110 . The recess 110 and tab 210 shown in FIG. 6 may be located on the generator 10 (FIG. 1) similarly to the location of the recesses 110 and quick release fasteners 54 shown in FIGS. 1 and 3.
In FIG. 6, when connecting the fuel tank 14 to the frame 18 , the fuel tank 14 is positioned above the support portion 26 such that the slots 222 are aligned with the tabs 210 . The tabs 210 are pivoted to extend in the same direction as the slots 222 . The fuel tank 14 is placed on the support portion 26 and the tabs 210 extend through the slots 222 . The tabs 210 are in a disengaged position when the tabs 210 are aligned with the slots 222 , and the tabs 210 extend in the same direction as the slots 222 . The clamping portion 218 may contact a retaining surface 226 on the support portion 26 . Once the tabs 210 extend through the slots 222 , the tabs 210 may be pivoted 90 degrees from the disengaged position to an engaged position to clamp the clamping portion 218 to the support portion 26 and retain the fuel tank 14 to the frame 18 . FIG. 6 illustrates the tab 210 in the engaged position.
The clamping portion 218 may include nubs 230 that project from the clamping portion 218 adjacent the slot 222 . The nubs 230 may lock the tab 210 into the engaged position as the tab 210 is pivoted with respect to the slot 222 . The nubs 230 may be aligned approximately normal to the slot 222 , and the tab 210 may slightly deflect the nubs 230 as the tab 210 is rotated 90 degrees and locked into the engaged position. The tab 210 may be spring-loaded to enable it to clear the nubs 230 . The nubs 230 may resist movement of the tab 210 from the engaged position to the disengaged position. The tab 210 holds the retaining surface 226 and clamping portion 218 from substantially moving with respect to each other.
To remove the fuel tank 14 from the frame 18 , the tabs 210 are pivoted to the disengaged position to align the tabs 210 with the slots 222 . The quick disconnect 162 (FIG. 2) is disengaged to disconnect the fuel tank 14 from the frame 18 . The fuel tank 14 may then be removed from the frame 18 .
FIG. 7 illustrates a variation of the embodiment shown in FIG. 6 . In FIG. 7, the fuel tank 14 extends over the elongated rods 102 of the frame 18 , and includes at least one recess 110 that provides clearance for the quick release fastener 54 , which includes the tab 210 . Once again, the tab 210 may pivot with respect to the frame 18 to engage or disengage the fuel tank 14 . A clamping portion 310 is at least partially disposed within the recess 110 , and the clamping portion 310 includes an elongated slot 314 . Similar to the previously described embodiment, the fuel tank 14 is initially positioned on the support portion 26 such that the slots 314 are aligned with the tabs 210 .
In the illustrated embodiment, the slot 314 is enclosed within the clamping portion 310 , and the slot 314 extends in substantially the same direction as the elongated rod 102 . Alternatively, the slots 414 could extend in any direction relative to the elongated rod 102 , as long as the tab 210 may be aligned with the slot 314 . Once the fuel tank 14 is positioned on the support portion 26 and the tab 210 extends through the slot 314 , the tab 210 may be pivoted 90 degrees from the disengaged position to the engaged position to clamp the clamping portion 310 and retain the fuel tank 14 to the frame 18 . FIG. 7 illustrates the tab 210 in the engaged position.
As described above, the clamping portion 310 may include nubs 318 that project from the clamping portion 310 adjacent the slot 314 . The nubs 318 may lock the tab 210 into an engaged position as the tab 210 is pivoted with respect to the slot 314 . Tab 210 may be spring-loaded to enable it to clear nubs 318 . The support portion 26 includes a retaining surface 322 , and the tab 210 holds the retaining surface 322 and clamping portion 310 from substantially moving with respect to each other. To remove the fuel tank 14 , the tabs 310 are pivoted to the disengage position and aligned with the slots 414 , and the quick disconnect 162 (FIG. 3) is disengaged. The fuel tank 14 may then be removed from the frame 18 .
FIG. 8 illustrates another alternate embodiment of the quick release fastener 54 that includes a C-shaped clamp 410 that retains the fuel tank 14 to the frame 18 . The fuel tank 14 includes a flange 414 that projects outwardly from the fuel tank 14 and extends along the sides 78 , 82 of the fuel tank 14 . The support portion 26 includes a lip 418 that is adjacent to the flange 414 when the fuel tank 14 is retained to the frame 18 . The flange 414 includes a clamping portion 422 , and the lip 418 includes a retaining surface 426 . The clamp 210 is engaged to clamp the flange 414 to the lip 418 and retain the fuel tank 14 to the frame 18 . The clamp 410 holds the retaining surface 426 and clamping portion 422 from substantially moving with respect to each other. The clamp 410 may be disengaged from the flange 414 to remove the fuel tank 14 from the frame 18 .
One skilled in the art will recognize that many variations of these illustrated embodiments of quick release fasteners 54 may be implemented to retain the removable fuel tank 10 to the frame 18 . For example, the quick release fasteners 54 , bolts 118 and tabs 210 (FIGS. 3-4 and 6 - 7 ) may be adapted to engage with an aperture in the flange 414 (FIG. 8 ). Additionally, the flange 414 (FIG. 8) may be combined with the support portion 26 having the elongated rod 112 (FIGS. 3-4 and 6 - 7 ) or the lip 418 (FIG. 8 ). Similarly, the lip 418 (FIG. 8) may also be combined with the recess 110 (FIGS. 3-4 and 6 - 7 ) and quick release fastener 54 . These and other similar embodiments of quick release fasteners 54 may be used to retain the fuel tank 14 to the frame 18 .
The foregoing detailed description describes only a few of the many forms that the present invention can take, and should therefore be taken as illustrative rather than limiting. It is only the following claims, including all equivalents that are intended to define the scope of the invention.
|
A generator embodying the invention comprises a removable fuel tank that is easily accessible, and may be easily removed from the generator. The generator includes a frame that supports an engine and the fuel tank. The fuel tank is removably interconnected to the frame with at least one quick release fastener. The quick release fastener may include a bolt, a pivoting tab, a clamp, or other similar quick release fasteners. Preferably, the quick release fastener may be engaged by hand, and does not require additional tooling. A fuel line between the fuel tank and the engine includes a quick disconnect attachment that prevents fuel flow and easily detaches the fuel tank from the engine. The fuel tank may be removed from the frame, taken to a gasoline station for refilling, and reattached to the generator for operation.
| 5
|
This is a division of application Ser. No. 08/899,745, filed Jul. 24, 1997 now abandoned.
DESCRIPTION OF THE INVENTION
BACKGROUND AND SUMMARY
The present invention relates to copper-based alloys for use in electronics for the manufacture of supports for components.
Copper, which, as is well known, is an excellent conductor of electricity, is used in many applications, especially in electronics; it is used as a support for electronic circuit components (lead frame) for the most varied components and especially electronic chips. In the production of circuits, the components are generally brazed, adhesively bonded and/or crimped and then hot-coated with plastics material on the copper support which must thus be temperature-resistant and preserve its mechanical characteristics.
Owing to this temperature resistance (restoration strength), copper-based alloys have been used; that enables the restoration strength to be increased while preserving a good conductivity.
The temperature strength, or what is referred to as restoration strength, corresponds to a mechanism leading to the softening of the copper alloy by activation of dislocation annihilation by re-heating to a high temperature. Restoration resistance is characterised by the maximum duration (for example longer than 10 minutes) of maintenance at an elevated temperature (for example 450° C.) after which the hardness of the metal remains higher than a predetermined value.
The measured conductivity of the alloy, given as a percentage, corresponds to the 100% conductivity of pure copper. This percentage conductivity is called IACS conductivity.
By way of example, the alloy Cu Sn 0.15, which is an alloy of copper and tin, is used.
The copper supports used in electronics must not only offer good mechanical strength and good temperature strength but they must also exhibit excellent solderability and/or brazing suitability; to that end, the copper alloy is coated with a layer of nickel. This layer of nickel is applied to the alloy before cutting the products, such as supports. This results in a substantial amount of nickel-coated copper alloy waste, which is expensive to recover because it is necessary to use electrolysis to separate the copper from the nickel and to recover it.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of temperature strength of various alloys over time in accordance with the present invention; and
FIG. 2 is a diagram of conductivity as a function of the content of nickel and iron of a pure copper-nickel-phosphorous alloy in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The aim of the present invention is to improve copper-based alloys for use in electronics in order to obtain alloys having high temperature strength and high conductivity and facilitating the recovery of manufacturing waste.
To that end, the invention relates to the use, for the manufacture of supports for electronic circuit components that are to be brazed, adhesively bonded and/or crimped at high temperature onto the support, of a copper-based alloy containing, as a percentage by mass, from 0.1 to 1% of nickel and from 0.005 to 0.1% of phosphorus, the remainder being copper or principally copper.
According to the invention, such an alloy may, in addition, contain up to 0.1% of iron and/or up to 0.5% of zinc.
This copper-based alloy has a good conductivity generally higher than 80% IACS in the composition ranges proposed, and also an excellent temperature strength, that is to say, restoration resistance, associated especially with the addition elements: nickel and phosphorus.
The copper-based alloy according to the invention is also very valuable from the economic point of view because it facilitates recycling of the waste occurring during the manufacture of supports or elements for electronics because, in this case, the alloy according to the invention is coated with a layer of nickel. The mechanical characteristics of this alloy are especially valuable.
The alloys according to the present invention offer numerous advantages. For example, their electrical conductivity is very good. It is easy to obtain an electrical conductivity higher than 70% IACS. It is even possible, as demonstrated by the Examples hereinafter, to ensure a conductivity higher than 80% IACS by varying the addition of phosphorus as a function of that of nickel and iron, and by limiting the content of residual elements (zinc, . . . ): special production programmes are therefore to be observed in order to optimise the annealing cycles and the formation fine precipitates of Nickle Phosphides.
The content of residual nickel and phosphorus in solution, after the most extensive precipitation possible, ensures very good resistance to restoration: softening is very slight, as demonstrated by the Examples hereinafter, when the alloy is maintained in a furnace even beyond 450° C. and would be negligible in the case of soldering, brazing or plastic encapsulation at temperatures of between 370 and 425° C.
The precipitates formed (of Ni 5 P 2 according to the most up-to-date thermodynamic calculations or more certainly of Ni 2 P according to analyses effected by loss of energy in transmission microscopy) permit significant hardening of the alloys according to the present invention. At the same time, they increase resistance to stress relief.
The alloys according to the present invention are inexpensive. They use only conventional addition elements. They also enable the nickel-coated copper waste to be recycled economically. Small amounts of impurities (zinc, silicon, . . . ) can be tolerated: according to known laws, they degrade the conductivity of the product. The marginal addition of other alloy elements, such as iron (up to 1000 ppm but preferably less than 100 ppm) can permit acceleration of annealing and an improvement in mechanical characteristics while hardly affecting conductivity.
The alloys according to the present invention are therefore especially suitable for electronic applications (grids, power components, . . . ) and would advantageously replace alloys such as Cu Sn 0.15.
The alloy according to the invention can be manufactured by casting processes normally used for copper-based alloys. The particular process selected for casting the alloy has no particular critical influence on the product obtained.
However, prior homogenisation of the alloy by dissolving all the alloy elements at high temperature (800° C. or more) is very desirable, especially where, for example, iron is added.
In order to obtain boards, it is possible, for example, to cast the alloy in strips, to mill it, then, after slight work-hardening, to subject it to homogenising annealing (from 800 to 850° C. for approximately 1 hour) followed by quench-hardening. It is also possible, and preferable, to cast the alloy in plates of conventional dimensions, and then first to hot-roll them (at from 650 to 1000° C. depending on the alloy elements) to a thickness of a few millimetres and then to cold-roll them.
The alloy can then be cold-rolled to the desired thickness with intermediate annealing operations.
The greatest possible reduction, and at least 50%, is preferable between two consecutive annealing operations: the duration of each annealing operation is thus substantially reduced with an improved final conductivity. The optimum annealing temperatures are between 400 and 600° C., with maintenance at the annealing temperature for at least two hours and, if possible, four hours. Longer durations generally ensure greater conductivity, except in the unfavourable case of competitive precipitations of addition elements with the phosphorus, for example.
The present invention will be explained hereinafter by means of two embodiments of copper-based alloys.
The results of hardness and conductivity measurements are given in appended FIGS. 1 and 2. FIG. 1 is a diagram of temperature strength at 425° C.; the time has been shown on the abscissa and the HV hardness has been shown on the ordinate. The diagram gives the graphs of Cu Sn, Cu Ni 0.4, Cu Ni 0.2 and the alloy FPG, that is to say, an alloy of copper containing from 950 to 1000 ppm Fe and from 330 to 370 ppm P.
The test consisted in increasing the temperature to 425° C. and remaining at that temperature for a period extending beyond the scale of the diagram.
FIG. 2 shows the conductivity graphs for various IACS percentages, the abscissa representing the mass in ppm of Ni and the ordinate representing the mass in ppm of P in the copper-based alloy.
EXAMPLE 1
The alloys of this Example are prepared in the manner indicated hereinafter. Cuttings of copper-phosphorus alloys (Cu-b1, Cu-b2) coated with nickel are melted in a channel induction furnace: at the end of the melting process, on the basis of a spectrometer analysis, adjustment of the content of phosphorus enables the desired composition to be obtained. The molten mass is then maintained for a few minutes at the same temperature (approximately 1200° C.) under a reducing cover of charcoal. Casting is effected in a water-cooled ingot mould measuring 200×400 mm, for example. The composition of the alloys prepared for this Example is given in the following Table.
______________________________________ Ni P Fe Zn______________________________________Cu Ni 0.2 2060 305 -- 3200Cu Ni 0.4 4410 300 -- 800______________________________________ (All the contents are given in mass ppm.)
The plates thus cast are reheated to a temperature higher than 840° C. and then hot-rolled to from 200 to 13 mm. They can then, at a temperature higher than 600° C., be either quench-hardened or not, as desired. The blank is then milled, cold-rolled to a thickness of 1.5 mm and then annealed under a hood with maintenance at 480° C. for 4 hours. The hardness in the annealed state is between 54 and 57 HV. The conductivities of the alloys Cu Ni 0.4 and Cu Ni 0.2 measured in this state are, respectively, 78.1% IACS and 79.4% IACS.
The high content of residual zinc has a substantial effect on conductivity. On the basis of the known effect of zinc in solution on conductivity, it is possible to estimate that Cu Ni 0.2 and Cu Ni 0.4 alloys containing no addition element other than nickel and phosphorus at the contents indicated, would have conductivities of 83% IACS and 79% IACS, respectively.
In that metallurgical state, after a fresh reduction by rolling of 20%, the conductivity hardly varies and the hardness reaches from 107 to 110 HV. It is equivalent to that obtained under the same conditions with a Cu Sn 0.15 alloy.
At this level of work-hardening, strip samples are annealed at different temperatures from 360 to 480° C. for 10 minutes. The fall in hardness with temperature in the case of the Cu Ni 0.4 alloy is compared with that measured for a Cu Sn 0.15 alloy. The softening temperature of the Cu Ni 0.4 alloy is higher than 460° C. when that of the Cu Sn 0.15 alloy is of the order of 440° C.
EXAMPLE 2
New alloys, according to this Example, were prepared in the manner indicated hereinafter. High-purity copper is melted in a channel induction furnace: the introduction of alloy elements is effected in the form of pure nickel, copper phosphide 85-15 and metal silicon until the desired composition is obtained. The molten mass is then maintained at the same temperature (approximately 1200° C.) under a charcoal cover. The composition is gradually modified in order to obtain a wide range of different alloys. Billets are taken from the bath and cast for each new composition (diameter: 25 mm, height: 40 mm). The composition of each alloy prepared for this Example is within the ranges indicated in the following Table.
______________________________________ Ni P Fe Si______________________________________minimum 2870 <10 <10 0maximum 4300 910 80 100______________________________________ (All the contents are given in mass ppm.)
Each of the billets is homogenised by being maintained at 850° C. for 1 hour and then being quench-hardened in water. In that state, they are deformed by more than 70% (reduction in height) by compression in a hydraulic press. They are then annealed in such a manner that, for each alloy, the maximum conductivity is obtained. Correlations were then established between these measured conductivity values and the composition of the alloys. The correlations also take into account the previous characterisations, indicated in Example 1.
Lines of the same conductivity can then be plotted in the plane of the nickel and phosphorus contents, without any other addition element, in the case of pure copper-nickel-phosphorus alloys. The results are indicated in FIG. 2.
|
A method for forming supports for use in electronic components. A plate of copper-based alloy including from 0.1 to 1.0% by weight nickel, and from 0.005 to 0.1% by weight of phosphorus is melted and cast. The alloy includes fine precipitates of nickel phosphides throughout the copper matrix. The plate is subjected to a series of deformation operations including, rolling and intermediate annealing at a temperature in the range of 400° to 600° C., with the annealing temperature being maintained for two to four hours, thereby maximizing the production of fine precipitates of nickel phosphides within the alloy. After alloy formation, the plate is coated with a layer of nickel, cut into a desired shape, and secured to an electronic component.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a Divisional of currently pending U.S. patent application Ser. No. 13/489,537, filed on Jun. 6, 2012 the subject matter of which is incorporated herein in all its details.
FIELD OF THE INVENTION
The present invention relates to semiconductor devices, and more particularly, to gated-diodes that includes capping dielectric layers within the active semiconductor structures.
BACKGROUND AND RELATED ART
Semiconductor diodes, in particular gated-diodes, are often used in CMOS integrated circuits for important analog circuit functions including temperature sensing and bandgap reference voltage applications. For the analog applications to properly function, the forward-bias diode characteristics should be nearly ideal, as measured by the diode ideality factor (n) which should be nearly equal to a value of 1. In advanced CMOS technologies, achieving a gated-diode structure with good ideality near 1 can be challenging because of the widespread use of Reactive Ion Etching (RIE), which can damage then semiconductor structures. RIE related damage is known to degrade diode ideality. Thus, in order to achieve a good diode ideality, the RIE damage should be eliminated or minimized.
Diodes in general are formed by creating abutting semiconducting regions of N-doped (excess electrons) and P-doped (excess holes). Preferably, one but not both regions is more heavily doped, creating either an N+/P diode or a P+/N diode. N-doped regions are typically formed by implanting or diffusing N-type donor dopant species, such as arsenic or phosphorus, into the semiconductor material such as silicon. Similarly, P-doped regions are formed by implanting or diffusing P-type acceptor dopant species, e.g., boron into a region adjacent to and contacting the N-type region. Typically, a dopant activation thermal cycle or heating is necessary to make the dopants electrically active.
Gated-diodes formed as described, with the addition of a gate electrode and gate dielectric located at or near the location of the P-N junction. Often but not always, the gate electrode serves as a masking structure to allow creating a self-aligned P-N diode wherein the edge of the gate electrode defines the location of the P-N junction. Self-alignment can be achieved when the P-N junction is formed by ion implantation, and the gate electrode is sufficiently thick to block either the heavier P+ or N+ region implant from penetrating through to the underlying semiconductor substrate, and is wide enough laterally to allow a photolithography mask to consistently land on the gate even in the presence of loose manufacturing alignment tolerances. Generally, it can be advantageous to achieve good diode ideality by locating the P-N junction underneath the gate electrode and gate dielectric because this region is typically a high quality interface largely free of defects. Avoiding defects in and around the P-N junction region is important for achieving good ideality, as defects are known to create generation and/or recombination sites which degrade the diode ideality.
Dielectric capping layers (such as nitride or oxide) on top of gates are commonly used in CMOS fabrication. Examples of the uses for these dielectric capping layers include use as a hard mask for gate electrode patterning and increasing the gate stack thickness for ion implantation blocking effectiveness. A gate electrode hard mask is a layer or layers patterned on top of a blanket gate electrode, which protects desired regions from RIE, thus forming patterned gate electrodes. This is in contrast to soft mask based patterning where the pattern is formed using photoresist. Oftentimes it is beneficial to keep the dielectric hard mask on top of the gate even after the gate electrode etching has been completed and during subsequent ion implantation steps required for building the gated-diode and Field Effect Transistors (FET). The additional dielectric layer contributes to blocking ion implantations, such as source/drain or halo implants from penetrating through the gate electrode into the channel. The dielectric layer is typically removed by RIE prior to a silicide formation, to enable the gate electrode region to be silicided. However, RIE can damage and introducing defects within and nearby the gated diode (P-N junction) region, resulting in a degraded ideality, that ultimately leads to poor circuit functionality in temperature sensor, bandgap reference voltage and other analog circuits that rely on good diode ideality.
Generally, all the gates and diffusions of a sub 250 nm technology have silicide formed to minimize resistance, knowing that silicidation of silicon and polysilicon regions reduces the resistance which results in increased transistor and circuit performance.
FIG. 1 is a perspective view of a prior art structure for a diode and a FET as part of integrated circuit. For simplicity, a single N-FET is shown, but it should be understood that N-FETs and P-FETs can be used together as part of CMOS integrated circuits. The fabrication sequence for the conventional structure shown in FIG. 1 results in damage to the diode which degrades the diode ideality. Note that in this prior art structure and P+/N diode is shown, but it should be understood that an N+/P diode can also be used.
Accordingly, there is a need for a structure that provides the benefits of a dielectric capping layer on top of the gate electrode of the gated-diode to avoid the diode ideality degradation of removing the capping layer that is desired for advanced CMOS integrated circuits.
SUMMARY
In one aspect, an embodiment of the invention provides a method of manufacturing a chip having an FET with a silicided high-K gate stack, source, and drain on high performance devices, with an adjoining diode having a silicided cathode and anode regions and a non-silicided high-K gate stack structure, the use of silicide implying a gate first high-K metal gate process with polysilicon in the stack.
In another aspect, an embodiment provides a polysilicon gate of the gated-diode that does not require silicidation as a gate terminal which is not intended to carry a significant current if the gate dielectric is sufficiently thick, such that the higher resistance of the non-silicided polysilicon is not a concern. The polysilicon gate of the gated-diode separates the cathode and anode implants, blocking the silicide between the anode and cathode. Because the gate electrode of the gated-diode does not require siliciding, it avoids the need to remove the cap from the gate over the device. By protecting the gated-diode with resist during a cap removal etching process, damage to the gated-diode due to etching can be avoided in view of etching a gate capping layer creates recess and damage in silicon regions near the diode P-N junction that degrades the diode ideality. By avoiding damage, an excellent diode ideality can be achieved. With the cap layer in place on top of the gate, silicide is not formed on the gate, but as described previously, the gate terminal of a gated-diode does not need to carry significant current. Hence, a higher resistance of non-silicided gate terminal is not a concern.
In yet another aspect, a method of forming a semiconductor structure provided with a silicided high-K gate stack, source, and drain on high performance NFETs/PFETs and a gated-diode having a silicided anode and cathode regions and non-silicide HiK gate stack structure, the use of a silicide on the high-K gate stack of the FET implying a gate-first high-K metal gate process with polysilicon in the stack.
In still another aspect, a method of fabricating a semiconductor integrated circuit provided with an n-FET and/or a p-FET having a silicided gate, source, drain, and a gated-diode with silicided anode and cathode regions, and a non-silicided gate. The NFETs/PFETs, gated-diodes and other active or passive devices are connected to metal wiring to form an integrated circuit.
In a further aspect, an embodiment provides a method of fabricating a semiconductor structure on a substrate that includes an FET having a silicided source, a silicided drain and a silicided gate stack; and a gated-diode adjacent to the FET having a silicided anode, a silicided cathode and a non-silicided gate stack, the non-silicided stack having a top surface covered by a layer of a material that inhibits silicide formation.
In still another aspect, an embodiment provides a method of forming a semiconductor structure that includes forming on a semiconductor substrate an FET having a silicided source, a silicided drain and a silicided gate stack; and forming a gated-diode adjacent to the FET having a silicided anode, a silicided cathode and a non-silicided gate stack, the non-silicided gate stack having a top surface covered by a layer of material that inhibits silicide formation.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and which constitute part of the specification, illustrate the presently preferred embodiments of the invention which, together with the general description given above and the detailed description of the preferred embodiments given below serve to explain the principles of embodiments of the invention, wherein like reference numerals denote like elements and parts, in which:
FIG. 1 shows a perspective view of a prior art diode and an FET as part of integrated circuit illustrating the damage to the diode degrading the diode ideality.
FIG. 2 illustrates a perspective view of the SOI substrate of FIG. 1 following superimposing over a silicon substrate a buried oxide layer (BOX) followed by the SOI layer.
FIG. 3 depicts a perspective view of the structure illustrated in FIG. 2 wherein a shallow trench isolation (STI) is formed in the SOI layer isolating the n-well from the p-well, followed by planarization such as CMP.
FIG. 4 shows ion implantation into different regions to form n-well and p-well regions.
FIG. 5 shows a perspective view of the formation of the gate stack that includes a gate dielectric, a gate electrode, and a hardmask.
FIG. 6 shows gate patterning using a photoresist.
FIG. 7 illustrates the resulting structure after etching the hardmask, transferring the photoresist pattern.
FIG. 8 is a perspective view of the structure after removing the photoresist, leaving the etched hardmask in the desired pattern.
FIG. 9 shows the structure after etching the gate electrode and gate dielectric forming gates in the desired pattern.
FIG. 10 shows the structure after a conformal spacer material is deposited.
FIG. 11 shows the resulting structure after etching the spacer material, preferably by a directional Reactive Ion Etch (RIE) process that removes the spacer material from the horizontal surfaces while leaving it on the vertical sidewalls.
FIG. 12 illustrates opening areas by way of the photoresist masking to receive N+ doping by ion implantation, the N+ region serving as source drain regions of an NFET or the N-well contact of the diode.
FIG. 13 shows a photoresist masking step with open areas which are to receive P+ doping by ion implantation, the P-dopant species preferably including boron. The P+ region serves as the P+ portion of the diode or the source drain region of the PFET (not shown).
FIG. 14 is a perspective view of the structure following the removal of the photoresist.
FIG. 15 shows a photoresist covering and protecting the diode while exposing the FET region to an etch that removes the hardmask over the gate of the FET.
FIG. 16 illustrates the structure following RIE, highlighting resulting damaged regions, wherein the photoresist covers the diode region, leaving the diode protected from the hardmask RIE, thus preserving the diode.
FIG. 17 shows the structure following the removal of the photoresist.
FIG. 18 depicts the structure after the formation of the silicide on the exposed N+ or P+ regions including the gate regions not covered by a spacer or by a hardmask, the diode gate remaining unsilicided while the hardmask is kept.
FIG. 19 shows a planar view of the structure shown in FIG. 18 including a gated-diode and a FET, in this example an NFET.
FIG. 20 shows an embodiment with a gated-diode with a non-silicided gate formed with NFETs and PFETs provided with silicided gates.
FIG. 21 illustrates a planar view of the structure shown in FIG. 20 , including a gated-diode and a NFET and a PFET.
FIG. 22 shows a plan view of an embodiment of an alternate diode structure illustrating additional plan-view designs of gated-diode, in an embodiment showing the gated-diode formed within the perimeter of the gate.
DETAILED DESCRIPTION
Detailed embodiments of the methods and structures of the present disclosure are described herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the described methods and structures that can be embodied in various forms. In addition, each of the examples given in connection with the various embodiments of the disclosure is intended to be illustrative, and not restrictive. Further, the figures are not necessarily to scale, some features can be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the methods and structures of the present disclosure. For purposes of the description hereinafter, the terms “upper”, “lower”, “top”, “bottom”, and derivatives thereof shall relate to the disclosed structures, as they are oriented in the drawings.
Referring to FIG. 2 , an illustrative structure and a method for forming semiconductor FET devices on a semiconductor-on-insulator (SOI) substrate are described.
FIG. 2 shows a substrate [ 100 ], presently Silicon-on-Insulator (SOI). The SOI layer [ 102 ] is located above the buried-oxide layer (BOX) [ 101 ] and the substrate [ 100 ]. The buried oxide (BOX) layer [ 101 ] on the substrate [ 100 ] can be made as a silicon oxide, a nitride, a silicon nitride, and/or an oxynitride, e.g., silicon oxynitride, having a thickness ranging from 5 nm to 1000 nm, or preferably, from 10 nm to 200 nm, and still more preferably, from 10 nm to 25 nm.
The semiconductor-on-insulator (SOI) substrate can be employed as the semiconductor substrate. When employed, the SOI substrate includes a handle substrate superimposed by a buried insulator layer located on an upper surface of the handle substrate, and a semiconductor device layer located on an upper surface of the buried insulator layer. The handle substrate and the semiconductor device layer of the SOI substrate can include the same or different semiconductor material. The term “semiconductor” as used herein in connection with the semiconductor material of the handle substrate and the semiconductor device layer denotes any semiconducting material including, for example, Si, Ge, SiGe, SiC, SiGeC, InAs, GaAs, InP or other like III/V compound semiconductors. Multilayers of these semiconductor materials can also be used as the semiconductor material of the handle substrate and a semiconductor device layer [ 102 ]. In one embodiment, the handle substrate [ 100 ] and the semiconductor device layer are both made of Si.
The handle substrate and the semiconductor device layer can have the same or different crystal orientation. For example, the crystal orientation of the handle substrate and/or the semiconductor device layer can be { 100 }, { 110 }, or { 111 }. Other crystallographic orientations besides those specifically mentioned can also be used in the present disclosure. The handle substrate of the SOI substrate can be a single crystalline semiconductor material, a polycrystalline material, or an amorphous material. The semiconductor device layer of the SOI substrate is a single crystalline semiconductor material. A single crystalline semiconductor material (or monocrystalline semiconductor material) is a semiconductor material in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample, with no grain boundaries.
The buried insulator layer of the SOI substrate can be a crystalline or non-crystalline oxide or nitride. In one embodiment, the buried insulator layer is made of oxide. The buried insulator layer 101 can be continuous or it can be discontinuous. When a discontinuous buried insulator region is present, the buried insulator region exists as an isolated island that is surrounded by semiconductor material.
The SOI substrate can be formed utilizing standard processes including for example, SIMOX (separation by ion implantation of oxygen) or layer transfer. When a layer transfer process is employed, an optional thinning step can follow the bonding of two semiconductor wafers together. The optional thinning step reduces the thickness of the semiconductor layer to a layer having a thickness that is more desirable.
The thickness of the semiconductor device layer of the SOI substrate is typically from 100 Å to 1000 Å, with a thickness from 500 Å to 700 Å being more typical. In some embodiments, and when an ETSOI (extremely thin semiconductor-on-insulator) substrate is employed, the semiconductor device layer of the SOI has a thickness of less than 100 Å. If the thickness of the semiconductor device layer is not within one of the above mentioned ranges, a thinning step such as, for example, planarization or etching can be used to reduce the thickness of the semiconductor device layer to a value within one of the ranges mentioned above.
Referring to FIG. 3 , a shallow trench isolation (STI) [ 103 ] created by a fabrication sequence is shown including trench etching, dielectric deposition such as oxide, followed by planarization such as CMP. The isolation formed by the STI process includes patterning (e.g., deposition a sacrificial pad layer (e.g., pad oxide and pad nitride), patterning (e.g., by lithography) and etching STI trenches, preferably by reactive ion etch (RIE), filling the trenches with one or multiple insulators including but not limited to oxide, nitride, oxynitride, high-k dielectric, or any suitable combination of those materials. The planarization process, such as chemical-mechanical polishing (CMP), can be used to provide a planar structure. Besides STI [ 103 ] other isolation such as mesa isolation, local oxidation of silicon (LOCOS) can also be used. The sacrificial pad oxide and pad nitride can then be stripped.
FIG. 4 shows ion implantation into different regions to form n-well [ 104 ] and p-well [ 105 ] regions. The n-well ion implantation can be n-type dopant elements including arsenic or phosphorus. The p-well ion implantation preferably uses a p-type dopant material, including boron or indium.
Referring to FIG. 5 , forming a gate stack is illustrated including a gate dielectric [ 106 ], a gate electrode [ 107 ], and a hardmask [ 108 ]. The gate dielectric [ 106 ] can be selected from silicon oxide, silicon oxynitride, nitride, high-K materials such as hafnium oxide or stacked combinations thereof. Gate electrode [ 107 ] is a conductor or semiconductor, e.g., polysilicon or metal, e.g., TiN, or stacked combinations thereof. The polysilicon layer can be doped by way of ion implantation or in-situ doped during the deposition. The hardmask [ 108 ] is typically a dielectric, e.g., silicon oxide, silicon nitride or a stacked combination thereof.
Referring to FIG. 6 , gate patterning is shown preferably using photoresist, a mask exposure using optical source, and photoresist development leaving the photoresist in desired areas [ 109 ].
FIG. 7 shows the resulting structure after etching the hardmask, preferably using a RIE process, and transferring the photoresist pattern into the hardmask.
Referring to FIG. 8 , the structure is shown following the removal of the photoresist by way of a stripping process, leaving the etched hardmask in the desired pattern.
FIG. 9 shows the structure after etching the gate electrode [ 107 ] and gate dielectric [ 106 ], preferably using a directional RIE, forming gates in the desired pattern.
FIG. 10 shows the structure following the deposition of a conformal spacer layer [ 110 ]. The spacer material is preferably a dielectric such as silicon nitride or silicon oxide that can be deposited by way of Chemical Vapor Deposition (CVD), Atomic Layer Deposition (ALD) or Molecular Layer Deposition (MLD).
FIG. 11 illustrates the resulting structure after etching the spacer material, preferably using a directional Reactive Ion Etch (RIE) tot remove the spacer material from the horizontal surfaces but keeping it on the vertical sidewalls.
FIG. 12 shows a photoresist masking [ 111 ] that opens areas that are to receive N+ doping by ion implantation [ 112 ]. N-dopant materials preferably include arsenic or phosphorus. The N+ region serves as the source drain region of an NFET or as the N-well contact of the diode. Alternatively, the N+ region could be formed by etching a trench and filling it with epitaxially deposited semiconductor, such as N-doped SiC.
FIG. 13 shows a photoresist masking step [ 113 ] that opens areas set to receive P+ doping by ion implantation [ 114 ]. P-dopant materials may include boron. The P+ region serves as the P+ portion of the diode or the source drain region of the PFET (not shown). The photoresist is then removed, resulting in the structure shown in FIG. 14 . Alternatively, the P+ region can be formed by etching a trench and filling it with epitaxially deposited semiconductor, such as P-doped SiGe.
FIG. 15 illustrates the photoresist step which covers and protects the diode, while exposing the FET region to etching that removes the hardmask [ 108 ] over the FET gate. The hardmask etch is preferably performed by RIE etching. The RIE etching can result in damaging the exposed regions as will be illustrated with reference to FIG. 16 .
Referring to FIG. 16 , the structure is shown following RIE etching, illustrating the resulting damaged regions [ 116 ]. Because the photoresist [ 115 ] covers the diode region, it protects the diode from hardmask RIE damage, and preserves not only the diode, but it also avoids degradation of the diode ideality.
FIG. 17 shows the structure following the removal of the photoresist.
FIG. 18 shows a cross-section view of the structure after silicide [ 117 ] formation. The silicide can be selected from nickel silicide, titanium silicide, cobalt silicide, or any other silicide material. The nickel, titanium, cobalt or other similar metal is deposited on the entire structure. During at heating of the wafer, preferably by Rapid Thermal Annealing (RTA), the silicide forms as a reaction between the metal and the silicon on the exposed N+ or P+ regions including gate regions not covered by spacer [ 110 ] or the hardmask [ 108 ]. The FET gate is silicided leaving the diode gate unsilicided as a result of the hardmask still remaining in place. The unreacted metal on the spacer or the hardmask is etched away, preferably by aqueous chemistry.
Still referring to FIG. 18 , in one embodiment, the gated-diode shown is devoid of any damage resulting from the absence of siliciding the gate, and is further formed alongside the FET having a silicided gate that allows it to achieve a high-performance caused by the reduced gate resistance.
FIG. 19 shows an embodiment wherein the gated-diode with its non-silicided gate is formed alongside the NFET and PFET having a silicided gate. It should be noted that while the gated-diode is shown as a P+/N diode, an embodiment of the inventive structure could be equally applicable to a N+/P diode.
FIG. 20 shows a plan view of the structure illustrated in FIG. 18 depicting additional details of the structure. The non-silicided gate [ 123 ] of the gated-diode is shown in the region on top of the active region of the device, leaving the cap layer in place within the active region, thereby avoiding RIE damage to the active region of the diode. The gate [ 121 ] of the gated-diode is silicided outside the active region to the diode, over the STI, by removing the cap layer in the stated region that allows silicide to form. The silicide within the region enables a good contact between the contact [ 120 ] and the gate [ 121 ] of the gated-diode. Removing the cap layer in the region outside of the active area of the gated-diode does not create damage near the active region of the diode. Shown in FIG. 20 , the gate of the FET is silicided [ 122 ].
FIG. 21 shows a plan view of the structure from FIG. 19 , illustrating an embodiment of the gated-diode with a non-silicided gate [ 124 ] and NFET [ 125 ] and PFET [ 126 ] with a silicided gate. The gate of the gated-diode is not silicided [ 124 ] in the region above the active region of the device, and leaving the cap layer in place within this region, making it possible to avoid RIE damage in the active region of the diode. The gate of the gated-diode is silicided outside the diode active region [ 122 ], over the STI, by removing the cap layer in this region, thus enabling silicide to be formed. The silicide in this region provides good contact between the contact [ 120 ] and the gate of the gated-diode. Removing the cap layer in the region outside of the active area of the gated-diode does not create damage near the active region of the diode. The gate of the FETs [ 125 , 126 ] is silicided.
FIG. 22 shows a plan view of an embodiment of an alternate diode structure illustrating other plan-view designs of the gated-diode (NFET and PFET not shown). In an embodiment, the diode is formed within the perimeter of the gate. As previously described, the gate of the gated-diode is not silicided [ 128 ] in the region located above the active region of the device by leaving the cap layer in place in this region, to avoid RIE damage within the active region of the diode. The gate of the gated-diode is silicided [ 127 ] in an area beyond the diode active region and spanning over the STI, and removing the cap layer from the region, thereby permitting the formation of silicide.
While the present disclosure has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details can be made without departing from the spirit and scope of the present disclosure. In one therefore intended that the present disclosure not be limited to the exact forms and details described and illustrated, but fall within the scope of the appended claims.
|
A method of fabricating a semiconductor structure provided with a plurality of gated-diodes having a silicided anode (p-doped region) and cathode (n-doped region) and a high-K gate stack made of non-silicided gate material, the gated-diodes being adjacent to FETs, each of which having a silicided source, a silicided drain and a silicided HiK gate stack. The semiconductor structure eliminates a cap removal RIE in a gate first High-K metal gate flow from the region of the gated-diode. The lack of silicide and the presence of a nitride barrier on the gate of the diode are preferably made during the gate first process flow. The absence of the cap removal RIE is beneficial in that diffusions of the diode are not subjected to the cap removal RIE, which avoids damage and allows retaining its highly ideal junction characteristics.
| 7
|
BACKGROUND OF THE INVENTION
The present invention relates to apparatus and methods for the repair of Porsche automobile engines and, more particularly, to a replacement oil drain tube for fitting between the cylinder head and crankcase of such engines, the replacement tube being designed for installation on such engines without the removal of the cylinder head.
Porsche automobile engines are opposed cylinder, air cooled engines including a main engine block incorporating a crankcase and its associated crankshaft and fitted with opposed, outwardly extending cylinder assemblies fitted with cylinder heads mounting overhead cam shafts, rocker arms, and valve assemblies. These elements within the cylinder head assembly are pressure lubricated, leading to an accumulation of oil which drains to the crankcase through plural oil drain tubes. The tubes interconnect the head assembly and crankcase, outboard of and below the cylinder assemblies. These engines are designed with exhaust manifold assemblies positioned below the cylinder and head assemblies, further outboard from the cylinder than the oil drain tubes, so that the oil drain tubes are positioned between these manifolds and the engine cylinders. As a consequence, the oil drain tubes supplied by the manufacturer are subject to extremely high temperatures and large temperature fluctuations. The tubes are sealed, using gasket material, to both the engine crankcase and head assembly, and the seals, as well as the oil drain tubes themselves, are subject to failure and resultant oil leakage.
In the case of this particular engine, such oil leakage is particularly objectionable, since the oil commonly leaks onto the hot exhaust manifold where it burns, creating smoke and fumes.
In the past, repair of failing oil drain tubes has required the removal of the cylinder head assembly, so that even though the oil drain tubes themselves are a relatively inexpensive replacement part, the labor cost involved in repairing oil leaks is quite high.
SUMMARY OF THE INVENTION
The present invention alleviates the requirement for cylinder head removal in repair of leaking Porsche oil drain tubes by providing a unique drain tube design, thus eliminating most of the labor cost involved in making the repair.
Standard oil drain tubes supplied by the engine manufacturer comprise a hollow cylindrical tube fitted with a pair of external O-rings at opposite ends. These O-rings are each confined by a pair of annular ribs extending circumferentially around the ends of the tube to form an annular groove conforming to the O-ring cross section. The cylinder head assembly is provided with an outlet port having a circular aperture for fitting tightly with the O-ring at one end of standard oil drain tube. This circular opening extends from the end of the outlet to a shoulder which confines the oil drain tube from vibrating in an axial direction toward the cylinder head assembly. Similarly, the crankcase of the engine includes an inlet formed as a circular aperture for tightly fitting with the O-ring at the remaining end of the tube, and provided with a shoulder to prohibit the oil drain tube from vibrating axially toward the engine crankcase. Thus, the pair of shoulders retains the axial position of the standard oil drain tube while the pair of ports on the cylinder head assembly and crankcase are sized to seal with the O-ring at opposite ends of the tube. This construction has prohibited the replacement of such oil drain tubes in the prior art without the removal of the cylinder head from the main engine block, since the oil drain tube cannot be moved axially toward either end beyond the location in which it is to permanently reside, the shoulders prohibiting such movement.
The present invention involves a novel construction for a replacement oil drain tube which permits the O-ring at one end of the tube to slide or telescope along the tube. The main oil drain tube is maintained at the standard length, so that when assembly is completed the oil drain tube does not fit further into the cylinder head or engine block than does the standard tube. Placing the O-ring on a sliding assembly, however, permits the central portion of one end of the tube to be extended beyond the shoulder in the cylinder head during assembly, so that sufficient clearance is provided at the engine block end of the replacement oil drain tube to allow it to be rotated into position. After such positioning, the O-ring sliding assembly can be telescoped into position to seal with the cylinder head, at the same time engaging O-rings positioned around the outside of the oil drain tube to seal the telescoping elements.
When assembly is completed, the oil drain tube, which is subjected to substantial vibration during engine operation, still extends completely as a unitary item into both the cylinder head and the engine block, which would not be possible if a telescoping interconnection were placed somewhere along the length of the replacement tubes. The telescoping member thus has the effect of reducing the diameter at one end of the drain tube to allow it to be inserted beyond the shoulder in the cylinder head to provide clearance for insertion. After the telescoping member has been positioned in its final location and held by a stop, the structural integrity of the oil drain tube is equal to that of the original part.
These and other advantages of the invention are best understood through the detailed description which follows. This description references the drawings, in which:
FIG. 1 is a lateral, schematic, sectional view through a Porsche automobile engine with a replacement oil drain tube in accordance with the present invention installed;
FIG. 2 is a contracted elevation view of the oil drain tube of the present invention during assembly with the Porsche engine of FIG. 1 and showing sectional views of the interconnecting apertures for the oil drain tube at the engine crankcase and cylinder head; and
FIG. 3 is a contracted elevation view, partially in section, of the oil drain tube of the present invention installed in the apertures of the crankcase and cylinder head of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1, a Porsche automobile engine 11 is shown schematically by way of a lateral sectional view. The major engine components include a main engine block 13, including its crankcase 15 to which is bolted plural, laterally extending, opposed cylinders 17. An air cleaner 19 and carburetors 21 supply fuel and air to the intake manifold, while exhaust manifolds 23 duct exhaust gases beneath the engine to a tail pipe.
Attached to the outer ends of the cylinders 17 are cylinder head assemblies 19 which enclose the cam shafts, rocker arms and valve springs. These elements within the cylinder heads 19 are pressure lubricated with oil drawn from the crankcase 15, which oil, after running from the mechanisms within the cylinder heads 19, is returned to the crankcase 15 through plural oil drain tubes 25.
These tubes 25 are inclined toward the crankcase 15 so that return oil will flow by gravity to the crankcase 15. The tubes 25 are located below and outboard of the cylinders 17 and positioned between these cylinders 17 and the exhaust manifolds 23. Because of this placement, the tubes 25 are subjected to very high temperatures and large temperature gradients during engine operation. In addition, due to temperature expansion of the engine parts and vibration during engine operation, the tubes 25 and their sealing fittings are subjected to substantial movement and vibration during use. Both the temperature variations and mechanical motion tend to limit the life of sealing members used to seal the tubes 25 to the cylinder heads 19 and crankcase 15, ultimately causing failure and leakage of these members. It can be seen from FIG. 1 that oil leaking from either end of the tubes 25, and particularly from the end fitted into the cylinder heads 19, can cause leaking oil to drip on the exhaust manifolds 23, creating fumes and smoke.
At the cylinder head end of the tubes 25, the tubes 25 are fitted into a circular aperture 27 in fluid communication with the interior of the cylinder head 19. Similarly, at the crankcase end of the tubes 25, an aperture 29 is provided in the crankcase 15 for mounting this end of the tubes 25.
The replacement oil drain tube 25 shown in FIG. 1 includes a main body section 30 and telescoping section 31 adapted to move axially relative one another, as will be described in more detail below.
Referring now to FIG. 2, the details of the replacement oil drain tube 25, cylinder head aperture 27, and crankcase aperture 29 will be described. The cylinder head aperture 27 is formed as a hollow tubular member including a shoulder 33 separating a large diameter external tubular portion 35 from a smaller diameter internal tubular portion 37. Similarly, the crankcase aperture 29 is formed as a tubular element including an internal shoulder 39 separating a large diameter outer tubular portion 41 from a smaller diameter internal tubular portion 43. The axes of the apertures 27 and 29 are aligned for receiving the oil drain tube 25. The main body section 30 of the oil drain tube 25 comprises a hollow tubular member 45 constructed, for example, of aluminum. The tube 45 is formed unitarily with an enlarged end portion 47 which includes a pair of extending, circumferential ribs 49, axially spaced to support a resilient O-ring 51. The end 47 of the tube 45 is similar in construction to the original oil drain tube 25 supplied with Porsche automobile engines. Thus, as shown in FIG. 3. the resilient O-ring 51 is sized to seal tightly within the aperture 41 and the outer rib 49 has a larger diameter than the aperture 43. Thus, the outer rib 49 can abut the shoulder 39 to prohibit the tube 25 from moving axially toward the crankcase 15.
It will be understood that a unitarily formed end identical to the end 47 exists also at the other end of the standard oil drain tube 25. In the present invention, however, the remaining end of the tube 45, as shown in FIGS. 2 and 3, includes three axially spaced, circumferential grooves 53, 55 and 57. The latter two grooves 55, 57 are sized to receive a pair of sealing, resilient O-rings 59 and 61, respectively, whereas the former groove 53 is designed to receive a resilient split ring 63.
The telescoping section 31 is formed with identical external contours at the end 47, and thus includes a pair of extending, axially spaced, circumferential ribs 65 and 67 for seating a resilient O-ring 69. The telescoping member 31, however, is formed to have a smooth inside diameter sized slightly larger than the outside diameter of the tube 45. As shown in FIG. 3, with the telescoping member 31 extended to the end of the tube 45 and the split ring 63 positioned in the groove 53 to maintain the telescoping member 31 in this extending position, the O-ring 69 seats tightly within the tubular portion 35 of the aperture 27 and, in a manner identical to the other end 47, the rib 67 can abut the shoulder 33 of aperture 27 to prohibit the tube 45 from moving axially toward the cylinder head 19.
The outer diameter of the tube 45 is selected to be smaller than the inside diameter of the tubular portion 37 of aperture 27 in the cylinder head 19, so that, with the telescoping member 31 positioned away from the end of the tube 45 as shown in FIG. 2, the end of the tube 45 including the O-rings 59, 61 can be positioned within the tubular portion 37 of the aperture 27 to permit installation in a manner which will be described in detail below.
It will be understood that, with a standard oil drain tube having identical ends such as the end 27, the ribs 49 and 67 prohibit axial motion of the tube 25 in either direction. Thus, referring to FIG. 1, it is impossible to replace the tube 25 without removal of the cylinder head 19, incurring substantial labor costs. The present tube 25, however, permits replacement of the tube 25 without removal of the cylinder head 19. This is accomplished as follows.
Initially, the old, damaged tube 25 is removed from the engine, for example by cutting the central section of the tube 25 away so that each end of the tube may be withdrawn axially from the apertures 27 and 29. Referring to FIG. 2, the telescoping member 31 and split ring 63 are slid away from the end of the tube 45 to approximately the position shown in FIG. 2. The end of the tube 45 with the O-rings 59 and 61 in place is then positioned in the aperture 27 and axially slid into the small diameter tubular portion 37 thereof, the diameter of the tube 45 being small enough to permit substantial extension of the tube 45 into the small diameter portion 37 even though the tube 25 is canted at an angle to permit the remaining end 47 to be positioned below the aperture 29. Once the tube 45 has been positioned a sufficient distance within the small diameter portion 37 of the aperture 27 to allow the end 47 to clear the aperture 29, as shown in FIG. 2, the tube 25 may be raised at the end 47 and slid axially into the aperture 29, with the O-ring 51 engaging the large diameter tubular portion 41 as shown in FIG. 3.
The telescoping member 31 may now be moved axially toward the aperture 27, the inside diameter of the telescoping member 31 engaging and sealing against the pair of O-rings 59, 61. At the same time, the O-ring 69 tightly engages and seals against the large diameter tubular portion 35 of the aperture 27. Once the telescoping member 31 is completely extended, the split ring 63 may be slid along the tube 45 until it resiliently engages in the groove 53 to form a stop which prohibits movement of the telescoping member 31 toward the center of the tube 45.
It can be seen from FIGS. 2 and 3 that the main assembly operation therefore involves insertion of the end of the tube 45, including the O-rings 59 and 61, into the aperture 27 at an angle so that the end 47 clears the aperture 29. The tube 25 is then aligned with the apertures 27 and 29 and moved axially toward the crankcase 15, so that the end 47 enters the large diameter portion 41 of the aperture 29. The telescoping member 31 is then moved axially to the end of the tube 45 to engage the large diameter portion 35 of the aperture 27 to complete the installation. It can be seen from FIG. 3 that the split ring 53 engages the end of the telescoping member 31 so that, once installed, the replacement tube 25 operates identically with the original tube, that is, the extending ribs 49 and 67 prohibit axial movement which would dislodge the tube 25 at either end by abutting, respectively, the shoulders 39 and 33. The O-rings 55 and 57 seal tightly against the inner diameter of the telescoping member 31 so that the tube 45 is completely sealed at each of the apertures 27 and 29. Once in place, the tube 45 extends completely from within the aperture 29 to within the aperture 27 so that structural integrity is maintained.
Use of this tube 25 permits a relatively inexpensive replacement of the oil drain tubes in a Porsche engine without removal of the cylinder heads, while at the same time providing a structurally sound, well sealed unit for conducting oil from the cylinder head 19 to the crankcase 15.
|
A replacement oil drain tube for interconnecting the head and crankcase on a Porsche automobile engine permits the repair of such engines through a replacement of standard, single piece oil drain tubes with a telescoping oil drain tube assembly, eliminating the requirement that the cylinder head be removed from the engine for such repair.
| 5
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for the production of alkyl and/or alkenyl oligoglucosides by drying of an aqueous glucose/fatty alcohol suspension and subsequent acetalization of the dried mixture in the presence of acidic catalysts.
2. Statement of Related Art
Alkyl oligoglycosides are important nonionic surfactants for a number of applications. They are generally produced by acetalization of aldoses (mainly glucose) with fatty alcohols in the presence of acidic catalysts (direct process). However, to obtain high yields in sufficiently short reaction times, it is of advantage to carry out the reaction in the absence of water. More specifically, this means that only water-free starting materials, i.e. starting materials with a residual water content of not more than 2% by weight, may be used for the acetalization. International patent application WO 90/3977 is cited as representative of the extensive literature available on this subject.
The use of pure materials, for example pure water-free glucose, adds to the costs involved in the production of alkyl oligoglucosides to such an extent that economic production is often impossible. Accordingly, there has been no shortage of attempts in the past to use technical glucose based on inexpensive water-containing glucose sirups which have been dried to the necessary extent [EP-A1 0 319 616]. However, a major disadvantage in this connection was found to be that conventional drying processes always influence the quality and composition of the water-free products and, in particular, can contribute towards an unwanted increase in the content of oligosugars and polysugars.
Accordingly, the problem addressed by the present invention was to provide a new process for the production of alkyl and/or alkenyl oligoglucosides which would be free from the disadvantages mentioned above.
DESCRIPTION OF THE INVENTION
The present invention relates to a process for the production of alkyl and/or alkenyl oligoglucosides, characterized in that
a) aqueous glucose sirups and fatty alcohols are dried in a turbo dryer with rotating fittings to a residual water content of 0.05 to 0.3% by weight and
b) the resulting glucose/fatty alcohol suspensions are acetalized in known manner in the presence of acidic catalysts.
It has surprisingly been found that the drying of mixtures of water-containing glucose sirups with fatty alcohols in a turbo dryer gives water-free suspensions in which the content of oligosugars and polysugars is not unfavorably increased in relation to the starting material.
Glucose sirups are understood to be refined aqueous solutions of D-glucose, maltose and higher polymers of glucose (oligosaccharides, dextrins) which are obtained by acidic hydrolysis or enzymatic degradation of starch. The glucose sirups preferably used have a solids content of 50 to 85 and preferably 75 to 80% by weight and a DP1 degree (monomeric glucose content) of 80 to 99 and preferably 92 to 97% by weight, based on the solids.
Suitable fatty alcohols are primary alcohols corresponding to formula (I):
R.sup.1 OH (I)
in which R 1 represents linear or branched alkyl and/or alkenyl radicals containing 6 to 22 carbon atoms. Typical examples are caproic alcohol, caprylic alcohol, capric alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl alcohol, stearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol and/or erucyl alcohol and technical cuts which may contain these alcohols in various mixing ratios. A technical fatty alcohol cut based on hydrogenated coconut oil containing 12 to 18 and, more particularly, 12 to 14 carbon atoms is preferred.
The molar ratio of glucose sirup to fatty alcohol may be 1:2 to 1:10 and is preferably 1:3 to 1:6, the ratio being based on the glucose in the sirup.
Turbo dryers in the context of the invention are cylindrical dryers, preferably of horizontal construction, in which rotating fittings turning at high speed provide for fine distribution of the material to be dried. In one preferred embodiment, the fittings in question are, for example, vanes, blades or paddles which are mounted on a rotating shaft (peripheral speed 5 to 25 and preferably 10 to 20 m/s). The actual drying process takes place at wall temperatures of 100° to 180° C. and at gas-phase temperatures of 150° to 220° C., preferably in the presence of air, inert gases, such as for example nitrogen or superheated steam, heat transfer taking place by convection and through the heated wall of the dryer. A temperature of 120° to 180° C. and a reduced pressure of 20 to 300 mbar and preferably 50 to 100 mbar have proved to be optimal for the production of water-free glucose/fatty alcohol suspensions.
Since the heated air or the heated inert gas are introduced into the dryer at the same time as the moist product to be dried, the water is instantaneously evaporated. By virtue of the high heat of evaporation of water, this leads to a temperature-stabilizing effect so that the drying process may even be carried out at high temperatures without any decomposition of temperature-labile products.
Accordingly, particular features of the turbo dryers to be used in accordance with the invention are the short residence time, the narrow residence time spectrum and the high temperature stabilization which provide for moderate treatment of the material to be dried, particularly in regard to composition and color.
The dry material may be separated from the gas phase, for example in a vacuum separation vessel. To minimize product losses, it is also advisable to pass the waste gas through a heated column for example, to condense entrained fatty alcohol and to return it to the suspension.
The water-free glucose/fatty alcohol suspensions obtainable by the process according to the invention have a residual water content of 0.1 to 2% by weight. They may be acetalized in known manner in the presence of acidic catalysts, for example p-toluenesulfonic acid, to form the corresponding alkyl and/or alkenyl oligoglucosides.
The following Examples are intended to illustrate the invention without limiting it in any way.
EXAMPLES
A) Preparation of an Anhydrous Glucose/fatty Alcohol Suspension
The suspension was prepared in a horizontally arranged turbo dryer (type ES 2050 manufactured by the Vomm company of Milan, Italy; turbine diameter 340 mm, turbine length 2.4 m) in which a shaft fitted with vanes or blades rotated at high speed.
Starting Materials:
A1) Glucose sirup
Solids content: 75% by weight
DP1 content(*): 95% by weight
a2) C 12/14 Coconut oil fatty alcohol (Lorol® Spezial, a product of Henkel KGaA, Dusseldorf).
The starting materials were separately preheated to a temperature of 60° C. First, the fatty alcohol was pumped into the "head" of the turbo mixer by a piston pump. The glucose sirup was then introduced at some distance (looking along the longitudinal axis of the dryer) by a second piston pump. The molar ratio of glucose sirup to fatty alcohol was 1:4.5, based on the glucose in the sirup. At a rotational speed of 1,000 r.p.m., the mixture was finely dispersed in a hot, turbulent airstream and at the same time freed from water.
The drying temperature was in the range from 160° to 180° C. and was transferred on the one hand by convection and on the other hand through the heated wall of the dryer. A pressure of 100 mbar was established at the mixer exit.
The glucose/fatty alcohol slurry was discharged into a vacuum separation vessel at the mixer exit and the gas phase--containing steam and entrained fatty alcohol--was passed through a heated column and through a heated heat exchanger. The fatty alcohol was condensed and returned while the steam was precipitated in a following condenser.
The resulting glucose/fatty alcohol suspension had a residual water content of 0.1% by weight.
B. Acetalization
1,050 g of the water-free glucose/fatty alcohol suspension from A) were introduced into a 2-liter three-necked flask equipped with a stirrer, distillation column and internal thermometer and heated to 110° C. under a reduced pressure of around 20 mbar.
0.1 to 0.5% by weight, based on the glucose, of p-toluenesulfonic acid in the form of a 5% by weight solution in coconut oil fatty alcohol was then added to the reaction mixture. To displace the equilibrium, the water of reaction was continuously distilled off and the reaction was terminated after the separation of water had stopped and the residual content of unreacted glucose in the mixture was less than 0.1% by weight, based on the starting quantity. The reaction mixture was then neutralized with magnesium oxide and the excess coconut oil fatty alcohol was removed under reduced pressure (approx. 1 mbar) and at a temperature of 180° C. by means of a thin-layer evaporator.
|
The aliphatic primary alcohols are reacted with a glycose, more especially glucose, in the presence of an acidic catalyst in certain process steps so that particularly light-colored and alkali-stable alkyl glucosides are obtained after a subsequent, compulsory bleaching step, which represents an improvement over known direct synthesis processes. The process may be carried out both on a laboratory scale and also on an industrial production scale.
| 2
|
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application Ser. No. 60/792,524, filed Apr. 17, 2006 which is incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention is directed to a system and method for detecting tubular structures using hierarchical modeling, and more particularly, to a system and method for detecting and tracking a flexible tube in an object.
BACKGROUND OF THE INVENTION
Prevention of colon cancer can be achieved by detecting and surgically removing the polyps from the colon wail. However, the colonoscopy procedure used for detecting the polyps is a time consuming procedure that produces great discomfort for the patient. Virtual colonoscopy is an increasingly popular alternative in which the patient's colon is inflated with air through a rectal tube and then one or two Computed Tomography (CT) scans of the abdomen are performed. A polyp detection method is used on the CT scans and the detection, results are reported to the doctor for inspection. The current polyp detection methods exhibit a relatively large numbers of false positives due to the rectal tube used to inflate the colon. Those false positives can be reduced by detecting and segmenting the rectal tube and discarding any potential positives that are close to the rectal tube.
A rectal tube detection method should be fast and have a very low false positive rate, since false positives can decrease the detection rate of the overall polyp detection system. A known method for rectal tube detection handles the appearance by template matching, which is a relatively rigid method for detection, and the shape variability by tracking 2-dimensional (2D) slices. The tracking assumes that the tube is relatively perpendicular to one of the axes, which is often not true as shown in FIG. 1 . FIG. 1 illustrates that the rectal tubes 102 - 124 are flexible and variable shape and appearance. The method only handles two types of rectal tubes and was validated on a relatively small number of cases (i.e., 80 datasets). The method also involved a large amount of potentially time consuming morphological operations such as region growing.
Another known method for reducing false positives due to rectal tubes involves using a Massive Trained Artificial Neural Network (MTANN) to distinguish between polyps and rectal tubes which raise questions about the degree of control of the generalization power of the system. There is a need for a method for detecting flexible tubes in an object that provides a large degree of control against overfitting the data.
SUMMARY OF THE INVENTION
The present invention is directed to a system and method for populating a database with a set of image sequences of an object. The database is used to detect a tubular structure in the object. A set of images of objects are received in which each image is annotated to show a tubular structure. For each given image, a Probabilistic Boosting Tree (PBT) is used to detect three dimensional (3D) circles. Short tubes are constructed from pairs of approximately aligned 3D circles. A discriminative joint shape and appearance model is used to classify each short tube. A long flexible tube is formed by connecting all of the short tubes. A tubular structure model that comprises a start point, end point and the long flexible tube is identified. The tubular structure model is stored in the database.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will be described below in more detail, wherein like reference numerals indicate like elements, with reference to the accompanying drawings:
FIG. 1 illustrates a set of example frames of computed tomography images that display a rectal tube;
FIG. 2 illustrates a hierarchical, model for detecting a three dimensional flexible tubular structure in accordance with the present invention;
FIG. 3 illustrates a flow chart that depicts the method for detecting and segments a 3D freeform flexible tube in accordance with the present invention;
FIG. 4 illustrates how the voting strategy provides possible locations for the axes of the detected tubes;
FIG. 5 illustrates a model of a 3D circle and its parameters;
FIG. 6 illustrates manual annotations of different types of rectal tubes;
FIGS. 7 a and 7 b illustrate the parameters of a short tube and how a short tube is constructed from a pair of aligned 3D circles; and
FIG. 8 illustrates some examples of segmentation results in accordance with the present invention.
DETAILED DESCRIPTION
The present invention is directed to a learning-based method for detecting and segmenting 3D free-form flexible tubular structures, such as the rectal tubes using in CT colonoscopy. This method can be used to reduce the false positives introduced by rectal tubes in current polyp detection approaches. The method is hierarchical and detects parts of the tube in increasing order of complexity, from tube cross sections and tube segments to the entire flexible tube. The method uses a voting strategy to select candidate tube parts and increase the speed of the method. The detected tube segments are combined into a flexible tube using a dynamic programming algorithm. The present invention will be described in the context of detecting flexible rectal tubes used for colonoscopy procedures but it is to be understood by those skilled in the art that the method can be easily retrained to detect and segment other tubular 3D structures, such as airways and vasculature as well as stents and other similar medical implants.
The input to the system is a 512×512×N, where N could range between 400 and 1200, isometric CT volume and a set of query locations that are the output, of a first stage of a polyp detection. A label “RT” or “non-RT” is assigned to each query location stating whether the query location is at most at a specified distance from a rectal tube or not, e.g. 5 mm. The queries labeled as “non-RT” are passed through a second stage of polyp detection using a more involved algorithm and the remaining locations are reported to the physician as detected polyps.
For each CT volume, there are a number of query locations as input to the rectal tube detector. Of those, about 80% are automatically labeled, as negative because they are outside of a predefined box in the caudal region of the CT volume, where all rectal tubes of the training data have been found to reside.
The remaining locations are clustered together by computing connected components in a graph. There is an edge between two locations if they are less than a given distance D apart. For each cluster or connected component of the graph, the bounding box is computed and enlarged by D on each side. The corresponding sub-volume is cropped and the tube segmentation algorithm that will be described below is used in the sub volume. This way, candidate locations that are clustered together will be processed at the same time. Any location that is closer than some distance K from the segmented tube is labeled as “RT” and the rest as “non-RT”.
Using a trained classifier to detect rectal tubes provides a convenient way to manage the generalization power and the false positive rate of the system. The price to pay is the computational expense to search for all possible parameters that define the classifier. It is practically impossible to detect the entire rectal tube using a single classifier, because there are too many parameters to search since the tube is flexible. Instead, a part-based approach is used that starts with simpler and more rigid shapes and gradually increases the complexity of the shapes until the entire flexible tube is detected. FIG. 2 illustrates a hierarchical model of the learning based method used to detect 3D flexible tubular structures.
As shown in FIGS. 2 and 3 , a parts based approach is used which starts with simpler and more rigid shapes, in this case tube cross sections 201 a - 201 f (steps 302 , 304 ), which are then connected to form short tubes 203 a - 203 d (step 304 ) and connected again to form a long free-form lube 205 (step 306 ). To detect the tube cross sections (also referred to as 3D circles), ideally the trained detector would be applied to all possible locations X=(x, y, z), directions D=(d x ,d y ,d z ) and radii R, which is computationally prohibitive. Instead, the application of the detector is restricted to promising locations by using a voting strategy which will be described in detail hereinafter.
As indicated, candidate tube cross-sections or 3D circles having parameters C=(X, D, R) in which X=location, D=direction and R=Radius, are found using a voting scheme. Inside a cropped sub-volume, the gradient at all locations is computed. At the places where the gradient is larger than a predefined threshold, the 3D curvatures and the principal directions of the curvature are computed.
The voting proceeds as follows. Each voxel x casts one vote at the location v(x) in the direction of the gradient g x at a distance equal to the inverse of the largest curvature k(x). That is, the vote is casted at location
v ( x ) = x + g x g x 1 k ( x ) .
For a tubular structure, all locations on a tube cross-section will vote the center of the cross-section. The votes for two input tubes are shown in FIG. 4 with the white areas representing 5 votes. At locations y having at least 5 votes, the tube direction is computed as the median of the second principal directions at locations x that voted y·i.e., v(x)=y. In that direction, the most promising 3D circles C y (R) are obtained by computing the voting number:
N y ( R )=|{ xεC y ( R ),0.5 ≦R*k ( x )≦2 }|/|C y ( R )| (1)
for some discretization of C y (R). For a perfect tube of radius R and y on its axis, all xεC y (R) would have curvature k(x)=1/R and the voting number N y (R) would be π. For practical reasons, all candidate circles C y (R) having N y (R)≧1.3 are kept.
The 3D circle detector is specialized in detecting cross-sections of the flexible tube. The parameters of a 3D circle are shown in FIG. 5 . The parameters include the center location X=(x, y, z), the direction D=(d x , d y , d z ),|D|=1, that is normal to the plane of the 3D circle and the radius R of the circle. The features of the 3D circle are computed using 12 circles (3 locations and 4 radii) that are relative to the 3D circle.
To avoid overfitting the data, all the features are invariant to rotation about the 3D circle axis. The features are obtained as 8 types of axial invariant statistics: mean, variance, central symmetry mean, central symmetry variance, 25, 50 and 75 percentile and voting number. Each invariant statistic is computed on one of the 12 circles having one of the 4 radii (R/3, R, 5/3 R, 7/3 R) and one of 3 locations along the circle direction (X and X±2D). Each of the 12 circles is discretized and subsampled and one of the 8 types of statistics is computed for one of 70 different combinations of gradient, curvature and principal directions (sum, difference, product, etc.). In total there are 6720 features.
For training, the rectal tubes of 154 CT volumes are annotated using a generalized cylinder model. There are 3 different types of tubes in the training data. A semi-automatic algorithm based on dynamic programming is used to compute a tube annotation given two manually marked endpoints. The algorithm produces circle sections of the tube spaced 10 voxels apart, starting from one endpoint of the tube and ending in the other endpoint. The circle locations and radii are manually corrected to obtain the best alignment possible. The annotations 602 , 604 , 606 of three volumes are shown in FIG. 6 .
An example of how the 3D circle detector can be trained will now be described. For training of the 3D circle detector, 15,000 positive examples are generated from the manual annotations by interpolation, excluding the region close to the tip of the tube where there are lateral holes. From the candidate locations obtained by voting 207,000 samples that are at a distance of at least 35 voxels from the tube annotations are chosen as negative examples.
The training algorithm is a Probabilistic Boosting Tree (PBT) that learns a binary tree of strong classifiers, where each node is trained by Adaboost starting from the root. The PBT method is described in detail in co-pending patent application Ser. No. 11/366,722, filed Mar. 2, 2006 and entitled “Probabilistic Boosting Tree Framework for Learning Discriminative Models”, which is incorporated by reference in its entirety. The PBT is a method to learn a binary tree from positive and negative samples and to assign a probability to any given sample by integrating the responses from the tree nodes. Each node of the tree is a strong classifier boosted from a number of weak, classifiers or features. The PBT is a very powerful and flexible approach that is easy to train and to control against overfitting.
At each node, after training, the positives and negatives are run through the detector of that, node and the detected positives and false alarms are passed as positives and negatives for the right subtree, while the rejected positives and negatives are passed as training data for the left subtree. After training, the PBT can assign a probability to any new sample, representing the learned probability that the new sample is a positive example. A PBT with 6 levels is trained using 15 weak classifiers per node with the first two levels enforced as a cascade. The detection rate on the training samples was 95.6% and the false positive rate was 1.7%. The 3D circle detector usually misses the part of the tube that is not circular due to lateral holes in the tube. This is corrected by the short tube detector.
The short tubes are the parts from which the dynamic programming method (i.e., long tube detector which is described hereinafter) constructs the final segmentation. For good performance, there should be approximately the same number of short tubes starting at each of the detected circles. For that, the short tubes are detected in two steps. In the first step, 10 candidate tubes are found on each side of any detected 3D circle. For each 3D circle C 1 =(X 1 ,D 1 ,R 1 ), the 10 neighbor circles C 2 =(X 2 ,D 2 ,R 2 ) with the smallest alignment cost A(C 1 ,C 2 ) are found. The alignment cost depends on the relative position of the circles, and their radii as shown in FIGS. 7 a and 7 b.
FIG. 7 a shows the parameters of a short tube. FIG. 7 b shows for a given pair of aligned 3D circles C 1 =(X 1 ,D 1 ,R 1 ), C 2 =(X 2 ,D 2 ,R 2 ) a short tube T=(X 1 ,X 2 ,R 1 ,R 2 ) is constructed. The alignment cost can be defined as follows:
A ( C 1 ,C 2 )=α 2 +β 2 +0.1( d −10) 2 +0.2( R 1 −R 2 ) 2 −0.5( R 1 +R 2 ) (2)
where α,β<π/2 are the angles between the axis X 1 X 2 and D 1 and D 2 respectively. This way, the preferred circles C 2 are those which are best aligned in direction, have similar and large radii, and are at a distance close to 10 voxels.
The parameters of a short tube are T=(X 1 ,R 1 ,X 2 ,R 2 ). For each pair of aligned 3D circles C 1 =(X 1 ,D 1 ,R 1 ),C 2 =(X 2 ,D 2 ,R 2 ) found as above, a candidate short tube is constructed, with parameters T=(X 1 ,R 1 ,X 2 ,R 2 ), using only the radii and positions of the 3D circles, as illustrated in FIGS. 7 a and 7 b.
The second step validates the constructed short tubes using the input data. For that, a short tube detector is trained and only those short tubes are kept whose probability is greater than a threshold. The short tube detector has the same features as the 3D circle detector, with the difference that the 12 circles on which the feature statistics are computed have positions X 1 ,(X 1 +X 2 )/2 and X 2 and radii R/3, R, 5/3R, 7/3R with R=R 1 ,(R 1 +R 2 )/2,R 2 respectively.
An example of a training set will now be described. For training 13,700 positive examples 10 voxels long were created from the manually annotated images. In addition, 40,000 negative examples were obtained at locations, directions and radii obtained by voting, all of which were of length 10 and of identical radii R 1 =R 2 . Another 9000 negative examples were obtained from aligned pairs of 3D circles that are at least 35 voxels away from the manual annotations. A PBT is trained with 6, levels, 20 weak classifiers per node, and the first two levels enforced as a cascade. The detection rate on the training samples was 95.1% and the false positive rate was 3.6%.
From the short tube detector a set of short lubes T={T 1 , . . . , T n } and a graph G=(T,E) are obtained whose nodes are the short tubes T. Two short tubes T i and T j are connected through a graph edge E i,j εE if they share one endpoint X and the have the same radius R at that endpoint, e.g., T i =(A,R 1 ,X,R) and T j =(X,R,B,R 2 ). All edges E ij for which the 3D angle α ij =AXB is not close to π, (i.e., α ij <5π/6 or α ij >7π/6) are removed. The weight of the edge is a measure of good continuation of the tubes:
E ij =|α ij −π|tan|α ij −π| (3)
There is also a unary cost for each short tube T=(X 1 ,R 1 ,X 2 ,R 2 ):
c ( T )=−1 n ( P ( T ))+0.2( R 2 −R 1 ) 2 (4)
where P(T) is the probability given by the trained short tube classifier.
In this dynamic programming framework, C ij k denotes the cost of the best of a chain of k short tubes starting with T i and ending in T j . This results in the following recurrence formula:
C ij k + 1 = min s [ C is k + E sj + c ( T j ) ] ( 5 )
For each k, the chain of short tubes S k is found that corresponds to the smallest C ij k . The chain S k with the largest length (in voxels) is the segmentation result. Some examples of segmentation results 802 - 806 are shown in FIG. 8 .
Having described embodiments for a method for detecting and tracking a flexible tube in an object, it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments of the invention disclosed which are within the scope and spirit of the invention as defined by the appended claims. Having thus described the invention with the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims.
|
The present invention is directed to a system and method for populating a database with a set of image sequences of an object. The database is used to detect a tubular structure in the object. A set of images of objects are received in which each image is annotated to show a tubular structure. For each given image, a Probabilistic Boosting Tree (PBT) is used to detect three dimensional (3D) circles. Short tubes are constructed from pairs of approximately aligned 3D circles. A discriminative joint shape and appearance model is used to classify each short tube. A long flexible tube is formed by connecting all of the short tubes. A tubular structure model that comprises a start point, end point and the long flexible tube is identified. The tubular structure model is stored in the database.
| 6
|
RELATED APPLICATION
[0001] This application is a divisional application from U.S. patent application Ser. No. 11/582,853, filed on Oct. 18, 2006, which in turn claims the benefit of priority from French Patent Application No. 06 50030, filed on Jan. 4, 2006, the entirety of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a method of cross-linking a composition associating a polyethylene-based silane-grafted polymer with a filler of any kind.
[0003] A particularly advantageous, but non-exclusive application of the invention lies in the field of insulating materials for power and/or telecommunications cables.
BACKGROUND OF THE INVENTION
[0004] Polyethylene is known for presenting excellent dielectric properties, and also low cost price. That is why it is nowadays in widespread use for making insulating layers of power and/or telecommunications cables.
[0005] In order to provide improved thermomechanical properties, polyethylene is generally used in a cross-linked form. It is known that establishing a lattice of chemical bonds extending in all three dimensions serves to increase the high temperature behavior of this particular type of insulating material.
[0006] Cross-linked polyethylene is usually fabricated by silane cross-linking. That now-conventional technique consists initially in grafting the base polyethylene with a silane, by adding radicals using a peroxide. Thereafter, the compound as grafted in that way is subjected to cross-linking by hydrolysis and then to condensation, which requires the presence of water and a condensation catalyst. It should be observed that the catalyst is commonly constituted either by dibutyl tin laurate (DBTL) or by dibutyl tin dilaurate (DBTDL).
[0007] With a polyethylene, the silane cross-linking technique nevertheless presents the drawback of being unsuitable for being implemented directly in ambient air if said polyethylene is filled. Unfortunately, in cable making, it is extremely common practice for insulating materials to include fillers. This applies in particular to flame-retardant fillers for improving the behavior of power cables and/or telecommunications cables in the event of fire.
[0008] In order to remedy that difficulty, the only solutions presently in use consist in implementing the second cross-linking step of the silane technique either in a pool for 24 hours (h) at 63° C., or else in a sauna for 15 h at 90° C.
[0009] Nevertheless, both of those solutions are particularly expensive because of the cost of the extra equipment that is needed, because of the cost of the energy required for operation, and because of the cost of maintaining the installation.
[0010] Furthermore, since marking inks do not withstand passing through a pool or a sauna, it is not possible to mark each cable directly on leaving an extruder, and the marking operation must necessarily be performed as an extra operation on leaving the bath of liquid water or of steam. Thus, a consequence of using a pool or a sauna is to complicate quite considerably the industrial fabrication method in terms of logistics, and that again constitutes more extra costs.
OBJECT AND SUMMARY OF THE INVENTION
[0011] Thus, the technical problem to be solved by the subject matter of the present invention is to propose a method of cross-linking a composition comprising both a polyethylene-based silane-grafted polymer and a filler, which cross-linking method makes it possible to avoid prior art problems, in particular by being substantially less complicated to implement and thus implicitly being less expensive.
[0012] According to the present invention, the solution to the technical problem posed lies in the fact that the cross-linking method consists in mixing the composition with a condensation catalyst constituted by lauryl stannoxane having the following formula
[0000] [(C 4 H 9 ) 2 Sn(OOCC 11 H 23 )] 2 O.
[0013] It should be understood that the term “silane-grafted polymer” conventionally designates a polymer on which a silane type compound has previously been grafted.
[0014] The concept of a “polyethylene-based polymer” relates to any low, medium, or high density polyethylene, and also any polyethylene-octene elastomer (POE), and regardless of the polymerization system involved.
[0015] Furthermore, it should be observed that the filler could, a priori, be of absolutely any kind.
[0016] The invention as defined presents the advantage of enabling a filled polyethylene to be cross-linked in ambient air and in a few days, with complete cross-linking being achieved within a period of less than 45 days. It is thus entirely appropriate to speak of self-cross-linking.
[0017] Consequently, the invention makes it possible to abandon the expensive and complicated step of passing through a pool or a sauna, and thus to eliminate the corresponding equipment. Independently of the purely monetary financial advantage associated with such omission, the resulting saving in time that results also serves to improve productivity.
[0018] Because of the self-cross-linking, cables can advantageously be marked continuously, directly at the outlet from an extruder. This also leads to a gain in productivity.
[0019] Furthermore, the use of a new catalyst does not require significant change to the overall industrial process of cable fabrication, and thus does not require significant change to the installations presently in use. In other words, this means that the cross-linking method of the invention can be implemented very easily using existing fabrication equipment.
[0020] According to a feature of the invention, the condensation catalyst is packaged in the form of a master batch.
[0021] This characteristic enables the lauryl stannoxane to be better dispersed within the batch, thereby achieving significantly greater effectiveness. For equivalent effect, it is consequently possible to use significantly less catalyst, thus implying a significant saving in terms of cost.
[0022] Packaging the lauryl stannoxane in the form of a master batch also makes it possible to measure out accurately the quantity of catalyst that is really necessary, which can be particularly advantageous given that the catalyst is liquid and is for use in very small quantities.
[0023] In particularly advantageous manner, the master batch comprises a polymer matrix having the lauryl stannoxane dispersed therein.
[0024] This naturally assumes that the polymer matrix of the catalyst master batch is compatible with the base polymer of the composition.
[0025] The polymer matrix of the master batch is preferably identical in nature with the base polymer of the composition.
[0026] This characteristic makes it possible in particular to avoid modifying the mechanical and dielectric properties of the final material.
[0027] In accordance with another advantageous feature, the composition contains 0.0036% to 0.0108% of condensation catalyst.
[0028] According to another advantageous characteristic, the composition contains 90 pcr to 190 pcr of filler.
[0029] In this respect, it should be understood that throughout this specification, the abbreviation “pcr” has the conventional meaning of percent of resin. Consequently, it designates the percentage by weight of a compound in question relative to the weight of the base polymer set arbitrarily as being 100.
[0030] According to another feature of the invention, the composition is also provided with at least one additive selected from a processing agent, an anti-oxidant, a colorant, an anti-UV agent, an anti-copper agent.
[0031] In particularly advantageous manner, the composition contains less than 3 pcr of processing agent.
[0032] According to another advantageous characteristic, the composition includes 0.5 pcr to 5 pcr of anti-oxidant.
[0033] According to another feature of the invention, the cross-linking method is implemented at ambient temperature.
[0034] According to another advantageous characteristic of the invention, the cross-linking method is implemented in ambient air.
[0035] Naturally, the invention also relates to any power and/or telecommunications cable including at least one insulating covering that is made from a composition cross-linked in application of the above-described method.
DESCRIPTION OF THE INVENTION
[0036] Other characteristics and advantages of the present invention appear from the following description of two comparative examples, said examples being given by way of non-limiting illustration.
[0037] The object of each of these Examples I and II is to compare the level of cross-linking in two identical filled polymer materials when left to cross-link in the open air, one of the materials including a condensation catalyst in accordance with the invention, and the other having only a prior art catalyst.
EXAMPLE I
Preparation of Samples
[0038] Two samples of materials A and B were prepared from two compositions that thus differed from each other solely in the nature of their respective condensation catalysts.
[0039] Specifically, the various ingredients for each of the compositions A and B were mixed, the resulting mixture was extruded, and the corresponding extruded sample was allowed to cross-link in the open air. It should be observed that in each case the condensation catalyst was added during extrusion, in the form of a master batch.
[0040] Table 1 below gives the respective compositions of the two material samples A and B.
[0000]
TABLE 1
Sample
A
B
Silane-grafted polymer (pcr)
100
100
Filler (pcr)
110
110
Processing agent (pcr)
3
3
Anti-oxidant (pcr)
1
1
DBTL (%)
0.072
—
Lauryl stannoxane (%)
—
0.072
[0041] It should be observed that the silane-grafted polymer in this first example was constituted by a linear low-density polyethylene grafted to 1% with a silane cocktail, which cocktail associated a peroxide and silane. Specifically, it was the composition sold under the name “CLDO” by the supplier Polimeri Europa.
[0042] The filler was of the flame-retardant type, being constituted by aluminum trihydroxide (ATH).
[0043] The DBTL used in sample A was as sold by the supplier Goldschmidt, under the reference Tegokat 218.
[0044] The lauryl stannoxane used in its sample B was as sold by the supplier Goldschmidt, under the reference Tegokat 225.
Hot-Set Test Under Mechanical Stress at 200° C.
[0045] In order to verify that each sample A and B had indeed cross-linked, it was subjected to a standardized hot-set test (HST) under mechanical stress.
[0046] That type of test is governed by the standard NF EN 60811-2-1. Specifically, it consists in loading one end of a dumbbell-H2 type test piece with a mass corresponding to applying stress equivalent to 0.2 megapascals (MPa), and in placing the assembly in an oven that is heated to a given reference temperature to within ±2° C. for a duration of 15 minutes (min). After that time, the elongation of the test piece while hot and under stress is measured as a percentage. The suspended mass is then removed, and the test piece is kept in the oven for five more minutes. The permanent elongation that remains, also known as remanence, is then measured and expressed in percentage.
[0047] The greater the extent to which a material is cross-linked, the smaller the values of elongation and of remanence. Furthermore, in the event of a test piece breaking during the test or in the event of its elongation exceeding 100%, under the combined effects of mechanical stress and temperature, then the result of the test is logically considered as being a failure.
[0048] The results of the hot-set tests under mechanical stress at 200° C. are summarized in Table 2 below.
[0000]
TABLE 2
Sample
A
B
Hot-set test (200° C.)
failure
success
Time
D + 36
D + 15
Elongation (%)
—
50
Remanence (%)
—
10
[0049] It should be observed firstly that only sample B was successful in passing the hot-set test at 200° C., and was capable of so doing after 15 days only. This means that only the catalyst of the invention is capable of enabling the filled polyethylene to self-cross-link in open air.
[0050] In contrast, it can be seen that sample A was not capable of passing the hot-set test at 200° C. successfully, even after 36 days. This confirms the known fact that a typical prior art catalyst is not capable of generating fast cross-linking in a filled polyethylene.
EXAMPLE II
Preparation of the Samples
[0051] The two material samples C and D of the second example were prepared in a manner analogous to that described above for Example I.
[0052] Table 3 specifies the respective compositions of the samples in question.
[0000]
TABLE 3
Sample
C
D
Silane-grafted polymer (pcr)
100
100
Filler (pcr)
110
110
Processing agent (pcr)
3
3
Anti-oxidant (pcr)
3
3
DBTL (%)
0.0036
—
Lauryl stannoxane (%)
—
0.0036
[0053] The major difference compared with the first example comes from the specific nature of the silane-grafted polymer common to samples C and D. Specifically, it was a polyethylene octene grafted to 3% with a silane cocktail, which in this example likewise associated a peroxide and a silane. Specifically, the composition sold under the name “Exact8203/LL4004(70/30)” from the supplier Exxon was used.
[0054] The filler was still of the flame-retardant type, and specifically was still constituted by aluminum trihydroxide (ATH).
[0055] The DBTL and the lauryl stannoxane used respectively in samples C and D were identical in kind to those used respectively in samples A and B.
Hot-Set Test Under Mechanical Stress at 200° C.
[0056] Samples C and D were subjected to the same hot-set test under mechanical test as in Example I. The results of the various tests are summarized in Table 4 below.
[0000]
TABLE 4
Sample
C
D
Hot-set test (200° C.)
failure
success
Time (days)
D + 27
D + 20
Elongation (%)
—
60
Remanence (%)
—
0
[0057] The conclusions are entirely similar to those formulated for Example I.
[0058] It can thus be seen that only sample D was successful in passing the hot-set test at 200° C., and it could do so after only 20 days. This confirms the fact that only a catalyst in accordance with the invention is capable of causing a filled polyethylene to self-cross-link in the open air.
[0059] It should also be observed that sample C was not capable of passing the hot-set test at 200° C. successfully, even after 27 days. This is further proof that a typical catalyst of the prior art cannot lead to rapid self-cross-linking of a filled polyethylene.
|
A method of cross-linking a composition comprising firstly a polyethylene-based silane-grafted polymer, and secondly a filler. The invention is remarkable in that the cross-linking method consists in mixing the composition with a condensation catalyst constituted by lauryl stannoxane of formula [(C 4 H 9 ) 2 Sn(OOCC 11 H 23 )] 2 O.
| 8
|
FIELD OF THE INVENTION
[0001] The invention relates to diode light sources with variable output color.
BACKGROUND OF THE INVENTION
[0002] Methods for varying the color of a light source can be divided into two cases, passive color conversion where filters etc. remove some frequencies to change the color, and active color conversion where fluorescent or phosphorescent substances alters the spectrum of the light from the light source by absorption and re-emission. Active color conversion has the advantages that it maintains the light power to a higher degree than passive color conversion. Further, active color conversion can produce wavelengths not contained in, or increase emission at wavelengths only weakly represented in, the emission spectrum of the light source. For this reason, active color converting substances are preferred for adjusting colors and color temperatures.
[0003] Light emitting diodes (LED's) are considered to become the next generation of lighting sources. Highly efficient inorganic diodes emit a band of light usually in the blue or red part of the spectrum. Green is usually obtained by converting blue light using green phosphor and white emitting diodes are obtained by converting blue light using green and red phosphors.
[0004] However, it is very desirable to be able to adjust the color characteristics of a diode light source in an electrically controllable way.
[0005] U.S. Pat. No. 6,375,889 describes a light source emitting light with a variable wavelength spectrum. The light source has multiple diodes with different emission spectra and a transmissive plate coated with a phosphor coating. The phosphor coating converts the color of the diodes by absorbing and re-emitting part of the incident light. The color of the light source is determined by the spectrum incident on the color converting phosphor coating, which is controlled by adjusting the relative emission intensity of the diodes.
[0006] This approach has the drawback that diodes emitting different colors age in different ways, so that the relative intensities giving a desired color will change over time. It is therefore necessary to use feedback based on e.g. a photo diode in order to compensate for this effect.
[0007] It is a disadvantage of the light source described in U.S. Pat. No. 6,375,889, that it is the emission intensity of the diodes, which is used to control the color. Firstly, for a given color of the light source, the diodes that contribute only little to this color must emit at a very low intensity—even though the light source as a whole emits the color at its highest intensity. Therefore, the maximum light intensities of the individual diodes must be grossly overdimensioned compared to the maximum output intensity of the light source.
[0008] Secondly, the color converting phosphors respond differently to the different emission spectra of the diodes. For a specific color and intensity of the light source, the diodes emit with a given relative intensity. If the intensity of the light source is to be adjusted while maintaining the color, adjusting the overall diode intensity with fixed relative intensity may alter the output color due to the varying response of the color converting phosphors. The relative intensity of the diodes must therefore be adjusted according to a feedback from a photo diode to keep the color mixing constant. This makes it difficult to perform the simple task of dimming a light source without changing its color.
SUMMARY OF THE INVENTION
[0009] It is an object of the invention to provide a color conversion cell to be applied in a method and a light emitting device, where the color or the color temperature can be electrically controlled.
[0010] According to the present invention, a color conversion cell with an active color converting substance is used to perform and control the color conversion of light from a light source.
[0011] Thus, in a first aspect the invention provides a color conversion cell comprising a color converting substance in a matrix held between two electrodes, the color converting substance having a second emission spectrum different from the first emission spectrum, the color conversion cell being electrically shiftable between at least a first state wherein the color converting substance will
[0012] absorb a first ratio, A 1 , of light incident on the cell,
[0013] emit light with the second emission spectrum, and
[0014] transmit a second ratio, T 1 , of light incident on the cell, and a second state wherein the first ratio, A 2 , is smaller than in the first state and wherein the second ratio, T 2 , is larger than in the first state.
[0015] The cell has two opposing and at least substantially transparent walls allowing light to pass through the cell when empty. The two electrodes are preferably transparent and form part of these walls.
[0016] The color converting substance is based on a photoluminescent substance such as fluorescent or phosphorescent dyes. The substance preferably has a high absorption at the first frequency spectrum and emits at the second frequency spectrum which may or may not overlap partially or completely with the first spectrum. The color converting substance may be formed by particles such as polymers, crystals, clusters, molecules, atoms etc., and may be fluid or solid. The matrix is the medium in which the substance is suspended, dissolved or embedded.
[0017] The color conversion can be controlled by controlling the degree to which the color from the light source is shifted to another color. The degree to which the color from a light source is shifted depends on how much of the light is absorbed and re-emitted by the color converting substance. Thus, the color conversion may be controlled by adjusting one or more of the following parameters:
[0018] the pathlength of the source light through color converting substance,
[0019] the color converting substance's density, distribution or extent in the media traversed by the source light,
[0020] the absorption cross section of the color converting substance, i.e. the probability that a photon will be absorbed by a particle of the color converting substance.
[0021] The color conversion cell may be shifted between the first and second state by adjusting one or more of the parameters mentioned above. The first ratio, A x , is an absorption coefficient defined as the quotient between absorbed light and incident light in the state X. It follows that 0≦A x ≦1. Similarly, second ratio, T x , is a transmission coefficient defined as the quotient between transmitted light and incident light in the state X. It also follows that 0≦T x ≦1. Preferably, the one or more parameters may be adjusted continuously to allow for a smooth transition between two color states. It is thus evident that the first and second ratios may take several values in between their values in the first and second state.
[0022] If there where no absorption, A x =0, the color converting substance would not emit any light, and similarly, if all light was absorbed, A x =1, the color converting substance would not transmit any light. However, unless A x is exactly equal to 0 or 1, there will be some absorption, some emission and some transmission, which is generally the case.
[0023] In a preferred embodiment, the color converting substance comprises anisometric color converting particles. The absorption cross section of such anisometric particles depends of their orientation relative to the propagation direction of the incident light. The anisometric color converting particles therefore have a high absorption orientation and a low absorption orientation in relation to light incident on the cell or particle. In this embodiment, the color conversion cell comprises means for controlling the orientation of the particles so that the anisometric particles can be at least substantially oriented in their high/low absorption orientations relative to the source light when the cell is in the first/second state.
[0024] The anisometric color converting particles may be dichroic fluorescent dye molecules having a larger absorption cross section in one orientation than in another. The molecules may be dichroic because of anisometric shape or because of intramolecular properties. Dichroic color converting particles may e.g. be rod-like molecules or disc like molecules, where the absorption cross section is high for light polarized parallel to the long axis of the molecule, and small for other orientations.
[0025] Alternatively, the anisometric color converting particles may be fluorescent dye particles shaped as flakes, rods, discs, ellipsoids, etc. where the amount of light incident on the particle depends on the alignment of the particle relative to the light.
[0026] In another alternative, the anisometric particles need not be fluorescent dyes themselves, but can have color converting substance attached to their surfaces. As the amount of light incident on the particle surface, and thereby on the color converting substance, depends on the alignment of the alignment. Here, the color converting substance itself may be isometric, which allows for a much larger selection of substances.
[0027] In one preferred embodiment, the means for controlling the orientating the anisometric color converting particles comprises a liquid crystal mixture containing fluorescent dichroic dye molecules. Here, anisometric and/or dichroic color converting particles are typically mixed with liquid crystals and the mixture is placed in a cell containing orientation layers as on top of transparent electrodes. Under the influence of the orientation layers the liquid crystal mixture become macroscopically oriented.
[0028] It is also possible to use various configurations in order to avoid polarization dependence. One such configuration is so called twisted configuration and involves rotation of the liquid crystal molecules within the cell. Such configuration is induced when a liquid crystal is provided with so-called chiral molecules. The orientation of the liquid crystal and hence the dichroic molecules can be altered when an electric field is applied across the cell. As an alternative, the means for controlling the orienting involves a suspended particle device wherein anisometric color converting particles are suspended in a liquid. In both alternatives, the means for controlling the orientation comprises the two electrodes and a voltage difference between these.
[0029] In another preferred embodiment, the color conversion cell involves an electrowetting cell as described in e.g. Nature 425, p. 383, hereby included by reference. The color converting substance can be mixed with an apolar liquid held together with a polar liquid in a small compartment with a hydrophobic surface which form a transparent section of the cell. By switching a voltage between the polar liquid and the hydrophobic surface, the apolar liquid will switchably wet the hydrophobic surface. This can be used to control how much of the transparent section of the cell that is covered with the color converting substance. In the first state of the color conversion cell, the apolar liquid will wet the hydrophobic surface so that the source light will illuminate the color converting substance. In the second state of the color conversion cell, the apolar liquid will at least substantially withdraw from said surface of the transparent section.
[0030] In still another preferred embodiment, the color conversion cell is adapted to adjust an average pathlength of the source light in the matrix containing the color converting substance inside the cell. If the average pathlength of the source light is longer in the first state of the cell than in the second state, more light will be absorbed and re-emitted in the first state, resulting on a larger color conversion. The pathlength may be adjusted by scattering the source light in the matrix, with an increased scattering leading to a longer pathlength. To this point, the color conversion cell preferably comprises electrically controllable scattering media such as polymer dispersed liquid crystal or liquid crystal gel or chiral texture. This embodiment have the advantage that the color converting substance need not be dichroic or anisometric, thus providing a larger selection of applicable substances. However the effect may be increased when anisometric particles or dichroic molecules are used.
[0031] Electrically controllable scattering can be obtained in various ways. The most known materials, which can be used for this purpose, are the polymer dispersed liquid crystal (PDLC), gels and cholesteric texture. PDLC is obtained when liquid crystal molecules are dispersed in an isotropic polymer. In the field off state liquid crystal molecules are oriented randomly in the polymeric matrix and the light is scattered randomly in all directions. Upon application of an electric field the scattering gradually decreases and when the liquid crystal molecules become totally aligned in the direction of the electric field the ordinary refractive index of the molecules match the refractive index of the polymer so the cell becomes transparent. In the case of the gels giving polarisation independent scattering, liquid crystals with negative dielectric anisotropy dispersed in an oriented anisotropic polymer matrix are preferably used. In the field off state the anisotropic network is oriented within the LC therefore there is no refractive index fluctuations within the cell so that the cell appears to be transparent. Upon applying an electric field across the gel the molecules tend to become oriented perpendicular to the applied field creating domains with various LC orientations causing scattering of light.
[0032] In the case of cholesteric texture surface treatment or polymer is used in order to induce the so-called focal conic texture in the liquid crystal which shows strong scattering of light. Upon application of an electric field liquid crystal molecules become aligned in the direction of the field and the scattering texture disappears.
[0033] The pathlength of the light may also be increased by a switchable resonating structure holding a color converting substance. The cell may comprise a thin layer of color converting material and a switchable reflector reflecting the spectrum of the light source but not the spectrum of the color converting substance. Also, the light source typically has a built-in reflector. In the on state of the reflector, light from the source resonate many times between the reflector of the color conversion cell and the reflector of the light source, thereby passing through the color converting substance many times. When the switchable reflector is not reflecting then light beam pass through the color converting substance only once. An example of a switchable mirror is cholesteric mirror as described in e.g. U.S. Pat. No. 5,762,823.
[0034] In a second aspect, the invention provides a light emitting device with adjustable color or color temperature comprising a light source having a first emission spectrum and a color conversion cell according to the first aspect of the invention. The color conversion cell is arranged to allow light from the light source to pass through the cell when empty.
[0035] Light emitted by the color converting substance will be emitted isotropically, some will be emitted in the direction of the source light whereas some will be emitted back towards the light source. In a preferred embodiment, the light emitting device comprises a reflector positioned between the light source and the color conversion cell, the reflector being at least substantially transparent for the source light and at least substantially reflective for light emitted by the color converting substance. The reflector reflects light emitted in directions back towards the light source. The reflector may be based on cholesteric liquid crystals or is a multi-layer dielectric reflector.
[0036] The efficiency of the color conversion can be improved by increasing the intensity of source light incident on the cell. For this purpose, the light emitting device may further comprise a layer with a collimating micro structure such as a lens or a grating positioned between the light source and the color conversion cell.
[0037] To allow for color mixing, the light emitting device may comprise multiple color conversion cells having different color converting substances. Arranging the cells behind one another as seen from the light source allows the light source to illuminate a succeeding cell through a preceding cell. Source light transmitted or emitted by the preceding cell may be converted by the succeeding cell resulting in multiple color conversion of the source light.
[0038] In a third aspect, the invention provides a method for adjusting the color or color temperature of light from a light source having a first spectrum, the method comprising the steps of
[0039] providing a color conversion cell comprising a color converting substance in a matrix held between two electrodes,
[0040] illuminating the matrix with the light source,
[0041] absorbing at least part of the source light illuminating the matrix in/by the color converting substance,
[0042] emitting light with a second emission spectrum from the color converting substance,
[0043] adjusting a voltage between the two electrodes to increase or decrease the amount of source light absorbed by the color converting substance and the amount of light with a second emission spectrum emitted by the color converting substance.
[0044] The basic idea of the invention is to control the color conversion by adjusting the color conversion of the incident light, instead of adjusting the amount incident light. This separates the light intensity, which is determined by the light source, and the light color, which is controlled by the color conversion cell(s).
[0045] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIG. 1 is a cross sectional view of a light emitting device according to the invention.
[0047] FIG. 2 illustrates high and low absorption orientations of preferred types of color converting substances.
[0048] FIG. 3 is a cross sectional view of a color conversion cell applying anisometric fluorescent dye molecules in liquid crystals.
[0049] FIG. 4 is the molecular formula for a dichroic fluorescent dye molecule.
[0050] FIG. 5 is a graph showing absorption spectra of the dichroic fluorescent dye molecule of FIG. 4 for different states of a cell.
[0051] FIG. 6 is a graph showing emission spectra of the dichroic fluorescent dye molecule of FIG. 4 for different states of a cell.
[0052] FIG. 7 is a graph showing emission spectra for a light source and a color converting substance for different states of a cell.
[0053] FIG. 8 is a cross sectional view of another light emitting device according to the invention.
[0054] FIGS. 9A and B are cross sectional view of a cell illustrating scattering of light for different states of the cell.
[0055] FIG. 10 is a graph showing emission spectra of a color converting substance for different states of a cell.
[0056] FIG. 11 is a cross sectional view of a light emitting device with a switchable reflector.
[0057] FIGS. 12A and B illustrates different states of a color conversion cell based on electrowetting.
[0058] FIG. 13 is a graph showing emission spectra of five sizes of CdSe quantum dots.
[0059] FIG. 14 is a graph showing absorption spectrum and emission spectrum a single quantum dot size.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0060] The following description proposes several light emitting devices for performing electrically controllable color conversion based on adjustable absorption and reemission by a color converting substance, typically a fluorescent dye. FIG. 1 illustrates a typical layout of such light emitting device. The designs presented in the present description primarily serves to illustrate the working principle of the invention and its embodiments, and secondly to present ways for carrying out the invention. These designs are not intended to restrict the scope of the invention in any way.
[0061] In FIG. 1 , a light emitting device 2 comprises an LED light source 4 and a color conversion cell 10 , all encapsulated in a lens 5 . The cell 10 has transparent glass walls 11 with transparent electrodes 12 and 13 and a reflector 15 at the wall nearest the LED. The cell contains a color converting substance 18 mixed in a liquid matrix 16 . The orientation of either the constituents of the matrix 16 , the color converting substance 18 , or both can be controlled by controlling a voltage between electrodes 12 and 13 with the voltage supply 19 .
[0062] Most preferred material for the electrode is indium tin oxide (ITO) which show high transparency and good conductivity. Depending on the type of device used the thickness of the gap containing the liquid will be in the range of 10-200 μm. The concentration of the color converting substance will be in the range 0.1-10%.
[0063] The color converting substance of the cell 10 emits in all directions. In order to redirect the light emitted through the wall 11 of the cell plate facing the LED 4 , a reflecting layer 15 is positioned between the LED 4 and the matrix 16 . The reflector 15 serves to transmit the light from the LED 4 but reflect the light emitted by the color converting substance. Such a layer may be a dielectric multilayer mirror, and may contain a structure or have a curvature in order to direct the reflected light in a certain direction.
[0064] In a first preferred embodiment, the absorption and reemission is adjusted by controlling the orientation of particles in a matrix relative to the direction of light. Since the orientation is adjusted in relation to the light from the light source, collimated light is preferred to have a well defined directionality of the light and ensure optimal performance. The first preferred embodiment has a number of different implementations described in the following in relation to FIGS. 1 through 10 .
[0065] In one implementation, the matrix 16 can be a liquid crystal matrix with a color converting substance 18 such as dichroic fluorescent dye molecules homogeneously mixed therein. The dichroic fluorescent dye molecules have a much higher absorption coefficient for light polarized along the long axis of the molecules than in lateral directions. As a result, the strength of absorption, and hence the intensity of their emission, can be controlled by controlling their orientation. As the liquid crystals can be reoriented by electric fields, the absorption/emission characteristics of the dye molecules can be controlled using a voltage supply 19 . An orientation layer 14 is added in the cell 10 to inducing a macroscopic orientation of the liquid crystals. For example rubbed polymer surfaces induce uniaxial planar orientation in liquid crystals while most other surfactants induce perpendicular alignment of the long axis of the liquid crystals with respect to the surfaces. Different orientation layers for inducing various orientations are well known to the person skilled in the art. Orientation layer 14 can also provide electrical isolation between the liquid and the solid substrate.
[0066] In FIG. 2 , a dichroic fluorescent dye molecules 21 is shown in its low absorption orientation (column A 2 ,T 2 ) and its high absorption orientation (column A 1 ,T 1 ) in relation incident light 20 . The orientation of the dye molecules 21 follows the orientation of a long axis of the liquid crystals in matrix 16 . If the liquid crystals have positive dielectric anisotropy their long axis will be aligned normal to the electrodes when V≠0, and, with a proper surface treatment, aligned parallel to the electrodes when V=0. Oppositely, if the liquid crystals have negative dielectric anisotropy their long axis will be aligned normal to the electrodes when V=0 and parallel to the electrodes when V≠0.
[0067] As light from an LED is unpolarized, and since liquid crystals in their “relaxed state”, V=0, are still aligned, only half of the incident light will be polarized parallel to the long axis of the crystals. Dichroic dye molecules show a high absorption towards light polarized along their long axis, and thus the aligned molecules will only have their high absorption orientation relative to half of the light. When applying dichroic dye molecules, it may therefore be necessary to apply a specially designed color conversion cell 30 shown in FIG. 3 . The cell 30 contains two liquid crystal matrices 32 and 34 with uniaxially oriented liquid crystals and dichroic fluorescent dye molecules. Orientation of the matrices 32 and 34 is made so that molecular orientations is 90 degree with respect to each other when V=0.
[0068] Thus in a first state of the cell 10 , the liquid crystals can orient the dye molecules 21 in their high absorption orientation in relation to light from the LED light source 4 . Adjusting the voltage between electrodes 12 and 13 can switch the cell 10 to a second state where the liquid crystals orient the dye molecules 21 in their low absorption orientation in relation to light from the LED light source 4 .
[0069] There exist a number of alternatives to the dichroic fluorescent dye molecules. FIG. 2 further shows other particles in low and high absorption orientations:
[0070] an anisometric particle 22 of a photoluminescent material composition (could also be disc-like),
[0071] sheet-like or disc-like particles 24 with fluorescent dye molecules 25 attached to the surface. One example being aluminumoxide flakes of thickness ˜100 nm and ˜1 μm diameter, and
[0072] rod-like particles 26 with fluorescent dye molecules 25 attached to the surface.
[0073] In those cases, proper alignment of the liquid crystals orients the particles in their low absorption orientation (A 2 , T 2 —column in FIG. 2 ) which dramatically reduces the light incident on the color converting particles as compared to their high absorption orientation (A 1 , T 1 —column in FIG. 2 ), and thereby reduces their absorption and re-emission. With these alternatives offer, non-dichroic dyes can also be used. This means that the fluorescent dye can be chosen from a much larger selection of dyes, offering a larger variety of absorption/emission spectra. Also, these particles does not have the inherent polarization dependence of dichroic particles, whereby the cell design 30 described in relation to FIG. 3 is not necessary.
[0074] In another implementation, the cell 10 contains a suspended particle device (SPD) instead of the liquid crystal matrix. Here, anisometric particles with large aspect ratios are suspended in a liquid. When no electric field is present, the particles will be randomly oriented, but applying a voltage between electrodes 12 and 13 will align the particles. The suspended particles themselves can be anisometric color converting particles 22 such as fluorescent plate or rod like particles. Alternatively, fluorescent dye molecules 25 may be attached to the surface of, or be incorporated inside, the larger suspended particles similar to particles 24 and 26 .
[0075] A test cell similar to the cell 10 of the preferred embodiment described in relation to FIG. 1 was fabricated to demonstrate the working principle of the invention. FIG. 4 shows the structure of a dichroic fluorescent perylene derivative dye dissolved (5% concentration) in a liquid crystal matrix (Zli 4788). This fluorescent dye has a high absorption in the range of 400-530 nm and emits in the range 500-650 nm.
[0076] FIG. 5 shows the absorption, A (in arbitrary units), as a function of the wavelength λ for the cell in its first and second state.
Spectrum 51 where the cell is in its first state with V=0. The liquid crystals are aligned normal to the direction of the incident light. Hence the molecular long axis of the dichroic fluorescent dye is parallel to the polarization of the light resulting in a high absorption, Spectrum 52 where the cell is in its second state with V≠0. The liquid crystals are aligned parallel with the direction of the incident light. In this case, the molecular long axis of the dichroic fluorescent dye is parallel to the direction of the light and thereby normal to the polarization of the light, resulting in a low absorption.
[0079] In FIG. 6 , the emission intensity, I (in arbitrary units), are shown as a function of the emission wavelength λ for the two states of the cell.
Spectrum 61 where the cell is in its first state with V=0, this corresponds to absorption spectrum 41 . The dichroic fluorescent dye molecules are aligned in their high absorption orientation in relation to the incident light. This gives a high absorption and a corresponding large emission in the emission spectrum of the dye, 500-650 nm. Spectrum 62 where the cell is in its second state with V≠0, this corresponds to absorption spectrum 42 . The dichroic fluorescent dye molecules are aligned in their low absorption orientation. As very little light is absorbed, the corresponding emission is very low.
[0082] It can be seen that the highest emission is obtained in the state or orientation in which the molecules show the largest absorption. This indicates that when such a cell is used in a light emitting device with a blue LED, a part of the blue light can be absorbed and re-emitted at longer wavelengths, thereby changing the emission characteristics of the LED. As the orientation of the fluorescent dye molecules depend on the applied electric field, the emission spectrum of the light emitting device can be electrically controlled.
[0083] Light emitting device with a blue LED and a cell similar to the cell 30 described in relation to FIG. 3 has been fabricated using the dye shown in FIG. 4 . FIG. 7 shows the emission spectra of the fabricated light emitting device, illustrating the change of the blue LED spectra for various voltages applied across the cell. It can be seen that for low voltages, a large ratio of the blue LED light (peak 71 centered at 470 nm) is absorbed and re-emitted in the range 525 nm-580 nm (peak 72 ). For increasing voltages, less blue LED light is absorbed and the emission from the dye decreases correspondingly.
[0084] FIG. 8 shows another light emitting device 80 according to the first preferred embodiment. The light emitting device 80 has several LEDs 4 illuminating multiple cells 81 and 82 with fluorescent dyes having different emission spectra. Combining e.g. blue LEDs with green and red emitting electrically controllable color conversion cells 81 and 82 , a light emitting device with controllable color and color temperature for use in e.g. lighting applications can be produced. Also, the light emitting device has no lens, but a reflector 17 reflecting both light from LEDs 4 and from the cells 81 , 82 . A microstructured layer 83 , such as a set of lenses, is positioned between the LEDs 4 and the cells 81 , 82 to collimate the light from LEDs 4 .
[0085] FIGS. 9A and B show still another implementation of the preferred embodiment. Here, the cell 10 contains an anisotropic gel 92 consisting of liquid crystal 93 with negative dielectric anisotropy in an anisotropic polymer 94 . A color converting substance 18 is mixed and oriented together with liquid crystal molecules. The gel was produced by adding the fluorescent dye of FIG. 4 to a mixture of non reactive liquid crystal molecules with 4% liquid crystal molecules with reactive end groups. The mixture was placed in a cell with transparent electrodes and an orientation layer which induced macroscopic orientation within the LC molecules so that they became oriented perpendicular to the cell surfaces. In this state the cell does not show any scattering and in with this orientation the absorption by the dye molecules is the lowest.
[0086] Upon application of an electric field, FIG. 9B , the dye and liquid crystal molecules tend to orient their long axis perpendicular to the applied field and cause the formation of domains giving rise to refractive index fluctuations within the cell causing strong light scattering. As the molecules tend to become perpendicular to the applied field they start also absorbing more light. The longer pathlength naturally also gives more incident light on the color converting substance and thereby a further increase in the absorption of light. Another advantage of this implementation is that the orientation of the color converting substance is random so that there is no polarization dependence.
[0087] Similarly to the emission spectra shown in FIG. 7 , FIG. 10 shows emission spectra of a light emitting device with a blue LED and the cell 90 described in relation to FIG. 9 .
[0088] The emission spectrum of the light emitting device is shown at various applied voltages across the cell. It can be seen that with increasing voltage, more blue LED light (peak 101 ) becomes absorbed and re-emitted as yellow light (peak 102 ) from the fluorescent dye in the cell.
[0089] FIG. 11 shows still another implementation of the color conversion cell 150 . Here, the cell has a layer 152 of color converting substance covered by a switchable reflector 151 controlled by the voltage supply 19 . The reflector can e.g. be a switchable cholesteric gel reflecting a band of light corresponding to the spectrum of the light source 4 . In the off state with V=0, the light resonates between the mirror and the source and mainly the converted spectrum comes out. In the on state, V≠0, mainly the light from the light from the source comes out.
[0090] In a second preferred embodiment, the absorption and reemission is adjusted by controlling the density, distribution or presence of color converting substance in a matrix. In this embodiment, the orientation of the color converting substances in relation to the light is of no consequence, and the light need not be collimated for optimal performance. Also, as the lack of directionality allows all fluorescent dye to be used isometric and anisometric. The second preferred embodiment is described in a number of different implementations in the following and in relation to FIGS. 1 and 11 through 13 .
[0091] In a first implementation of the second embodiment, the cell 10 of the light emitting device 2 of FIG. 1 adjust the distribution of the color converting substance 18 by electrowetting.
[0092] The working principle of an electrowetting cell 110 is shown in FIGS. 12A and B. Here a polar liquid droplet 111 is placed in an apolar matrix 16 on a hydrophobic coating 112 on an inside surface of the cell wall 11 . Due to the hydrostatic forces of the system, the droplet 11 does not spread but remains as a droplet in a corner of the cell, FIG. 12B . However, upon application of a voltage between electrode 12 and apolar matrix 16 , the droplet 111 it spreads on the surface coating 112 , FIG. 12A (Electrowetting).
[0093] By controlling the applied voltage, the coverage of the polar liquid 111 containing the color converting substance is adjusted. As more of the illuminated surface area is covered, or as the thickness of the polar liquid layer increases, more light will be absorbed and re-emitted at other wavelengths. Thus by electrically controlling the distribution of color converting substance in the cell, the color and the color temperature of the light source can be controlled.
[0094] Various kinds of fluorescent dyes can be used. Nano phosphors based on quantum dots (QD) might be particularly interesting as they show extremely high efficiencies, are very stable. Furthermore, their emission spectrum can be continuously tuned in wavelength simply by tuning their physical size. As an example, core-shell CdSe/ZnS nanocrystals exhibit strong band-edge photoluminescence with room temperature quantum efficiencies as high as 30-70%. The spectral position of the emission band is tunable from blue to red with increasing the size of CdSe core from ˜2 to 6 nm. Thin (˜2 monolayers) ZnS epitaxial shell grown around CdSe core considerably improves particle stability and the luminescence efficiency.
[0095] QDs are preferably prepared by wet chemical processes, and transfer molecules 15 are added to the surface after formation of the QD. QDs are semiconductor nanometer crystals and may comprise Group [II-VI] semiconductor compounds such as MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe and HgTe; and/or crystals of Group [III-V] semiconductor compounds such as GaAs, GaP, InN, InAs, InP and InSb; and/or crystals of group IV semiconductor compounds such as Si and Ge. In addition, the semiconductor compounds may be doped with rare earth metal cations or transition metal cations such as Eu 3+ , Tb 3+ , Mn 2+ , Ag + or Cu + . It may be possible that a QD consists of two ore more semiconductor compounds. Most likely the QDs comprise InN, InGaP or GaAs. The radii of the QDs are smaller than the exciton Bohr radius of the respective bulk material. Most likely the QDs have radii no larger than about 10 nm.
[0096] In FIG. 13 , the emission spectra of 5 sizes of CdSe quantum dots are shown. It can be seen that by changing the size of the quantum dots position of emission can be easily changed. In FIG. 14 , the emission spectrum 132 of a selected quantum dot is shown together with its absorption spectrum 131 .
|
The invention relates to light emitting devices ( 2 ) with variable output color. More specifically, the inventions provides a color conversion cell ( 10 ) which can be positioned in front of a light source ( 4 ) in order to generate other color or color temperatures. Typically the light source is a light emitting diode (LED) which is power efficient but emits in a narrow and fixed spectra. The new colors are generated by photoluminescence in fluorescent dyes contained in the cell. The color converting of the cell is electrically controllable, preferably by controlling the orientation, density or distribution of the fluorescent dyes, or by controlling a pathlength of the light in the cell.
| 5
|
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to shaped laminates and, more particularly, to a mold apparatus and method for molding clad products or partially clad products, which includes means to perform perimeter edge folding and perimeter trimming of a cladding layer in a single operation.
[0002] Current vehicle inner door panels comprise laminates of various types. In some inner door panels, a structural backing material is covered by an embossed covering, which is often vinyl. These panels are formed by bonding the covering to the backing in a mold which embosses the covering. Sometimes a filler material, such as cellulose or a foam sheet, is bonded between the backing and covering. After bonding, the periphery of these panels must be trimmed before vehicle installation. In the past, this trimming has been usually accomplished in a separate trim fixture.
[0003] The industry has developed a mold apparatus wherein the laminate is formed in a mold that also includes external trimming knives that provide a finished panel ready for vehicle installation. Such apparatus is shown in U.S. Pat. No. 4,692,108 to Cesano. All of the materials used in forming the Cesano type of laminated panel are preformed.
[0004] Another type of inner door panel in use is a laminate comprising a structural substrate of reinforced foam covered by a vinyl covering. This type of laminate is formed by placing the vinyl and reinforcing material in a mold and thereafter injecting foamable materials, which expand, set up and cure in the mold. After curing, this unfinished laminate requires further processing before it is ready for vehicle installation. It is removed from the mold and transferred to a trim fixture, where it is finally trimmed by accurately cutting the periphery with a water jet or the like.
[0005] Some problems attend this post-formation trimming operation. For example, the unfinished panel must be accurately positioned in the fixture. If it is not, the final panel will be out of dimension and unusable. Such a panel must be scrapped. Also, this post-formation trimming operation requires additional handling, equipment and labor.
[0006] It would be desirable to provide apparatus for forming a laminated panel which produces a finished panel needing no further processing.
[0007] It would be further desirable to provide a mold for forming a laminated panel comprising a structural foam backing having a decorative covering material that is ready for installation upon removal from the mold.
[0008] U.S. Pat. Nos. 4,243,456 (Cesano) and 4,328,067 (Cesano) disclose a laminating method and apparatus for making shaped laminates such as inner door panels for automobiles produced from a thermoplastic substrate and a flexible sheet material. A one-stroke operation molds, laminates, and cuts. The laminated products have protruding free edge portions so that cut edge portions can be subsequently covered with the protruding free edge portions. The apparatus and method do not provide for folding over of the laminate.
[0009] U.S. Pat. No. 4,327,049 (Miller) discloses a method of forming automotive headliners from a flat strip having laminated layers of resilient, cellular foamed plastic and a finish textile material. The strip is cut to form a flat blank which is heated to a temperature at which the foamed plastic loses its resilience. In its heated state, the blank is compressively formed and simultaneously trimmed in a mold to the desired size and contour. The cells adjacent the marginal edge of the blank are reduced in size to reduce the wall thickness of the blank. No edge folding takes place. Here, there is preferably a backing of a cellular thermoplastic material such as foamed polystyrene, an intermediate layer of a cellular, foamed thermoplastic such as polyurethane, and a finish layer formed of a thin textile material such as nylon.
[0010] U.S. Pat. No. 4,446,088 (Daines) discloses a method and mold for making an improved egg carton wherein an inwardly offset surface of the cover of the carton is cut in a plane transverse to the top of the cover. This disclosure is not directed to laminates, nor does it include a folding step.
[0011] U.S. Pat. No. 4,456,443 (Rabotski) discloses a steam chest molding process in general, wherein articles such as foamed boards or sheets are molded from expanded foam material, such as polystyrene. A cavity is filled with beads of partially expanded polystyrene and steam is used to completely expand the beads. The foam is then cooled with water.
[0012] U.S. Pat. No. 4,692,108 (Cesano) discloses a mold for the covering and trimming of products of plastics material, particularly for panels for the inside upholstery of motor vehicles. The covering material may be formed of plastic sheets, e.g., PVC, textile cloths, or fabrics. This covering material is heat secured to a sheet of any substantially rigid and heat formable (i.e. thermoplastic) material, e.g., polyolefins, and the like. Trimming knives are arranged in the female element of the mold, around the male element. The trimming knives are slidably guided transverse to the male element of the mold and are carried by slides either horizontally or at an angle of 0 to 15 degrees to the horizontal. The trimming knives first penetrate the plastic sheet and then cut both the covering material and the plastic sheet which simultaneously trims the edges of the plastic sheet and folds the covering material over so as to cover the edges of the plastic sheet.
[0013] U.S. Pat. No. 5,352,397 (Hara et al.) discloses a process for producing multilayer molded articles including folding of skin material over a back of a resin material. The skin material is supplied between a pair of molds and thermoplastic resin melt is supplied to form a multilayer molded article. At least one ejector is provided to fold an edge of the skin material toward the center of the mold over the back of the resin body. The skin material may be fabric, nets of fibers or resins, paper, metal foil or sheets, or a film of thermoplastic resin or elastomer or rubber. The thermoplastic resin melt may be expandable or nonexpandable resins such as thermoplastic resins (e.g., polypropylene, polyethylene, polystyrene, and the like). Numerous expansion members such as air cylinders or hydraulic cylinders are used both in the mold-closing direction and perpendicular to the mold-closing direction to effect the folding and trimming operations. Here, it would be desirable for folding and trimming to occur in substantially fewer steps.
[0014] U.S. Pat. No. 5,462,421 (Stein) discloses a method and mold for forming and trimming a shaped vehicle inner door panel. The panel includes a vinyl cover layer and a structural foam backing layer. Upper and lower mold members have peripheral seals which define a mold cavity when the mold is closed. A plurality of moveable trim blades are carried by the lower mold member adjacent the seal. The trim blades move between retracted, intermediate and extended positions. Hydraulic rams open and close the mold and move the trim blades. A cladding layer of vinyl and substrate are placed across the lower mold member and the mold is closed to seal the substrate and cladding layer about their periphery. As the mold closes, abutment surfaces on both mold members advance the trim blades to an intermediate position to pinch the cladding layer against the substrate inwardly of the peripheral seals. A two-part polyurethane liquid foam system is injected into the cavity. The liquid permeates the substrate and sets up within the area delimited by the trim blades. When the foam sets up, the trim blades are hydraulically extended to sever the substrate and cover layer and trim the door panel to its finished shape as the foam fully cures. The mold members are opened, the blades are spring retracted, and the finished door panel is removed.
[0015] U.S. Pat. No. 5,582,89 (Stein et al.) discloses a vehicle door panel manufacturing method that includes a first membrane with a foam backing, an apertured second membrane spread adjacent the foam backing of the first membrane, and a moldable rigid polymeric material providing a backing for the second membrane and supporting the membrane.
[0016] U.S. Pat. No. 5,718,791 (Spengler) discloses a method of laminating a trim panel and folding a cover sheet edge around the panel rim. A carrier frame holds the cover sheet material. A lower mold receives the substrate, while an upper mold laminates the cover sheet to the substrate. Edge-folding tools are laterally moveable and arranged around the perimeter of the upper mold. Here, the substrate is at least partially pre-formed and pre-molded.
[0017] U.S. Pat. No. 5,746,870 (Tomioka et al.) discloses a device for simultaneously carrying out vacuum forming, wrapping and trimming of a skin sheet about a base material in one molding stage.
[0018] The prior art also includes the in-mold edge folding and trimming of panels formed by structural reinforced injection molding (SRIM) using two-part polyurethane with encapsulated fiberglass mat construction and cladding laminates. The SRIM process requires a mold design specific to processing liquid materials which must include a liquid-tight seal around the full perimeter of the tool and necessarily precludes the ability to process materials in vertical platen molding machines. This requirement would also preclude the use of separate cutting surfaces in the male tool as the liquid will flash into gaps as small as 0.001″ creating severe tool maintenance problems.
[0019] Other processes exist today which feature the clad insert molded trim panels. None, however, is so complete after the molding step with partial cladding, edge folding, and trimming having taken place. Edge folding and trimming, for example, can not be accomplished in the molding operation of low-pressure injection molding or compression molding and must be done as a post mold operation. Partially clad products cannot be manufactured using the SRIM polyurethane process without extensive taping or masking of skin to keep the low viscosity liquid components from migrating to the visible side of the trim panel. Also, the male half of a SRIM mold must be liquid tight to keep polyurethane foam from building up in these areas. This process characteristic precludes the use of separate materials which can be used as cutting surfaces to extend blade life and obtain sharper cuts. In the SRIM process the foam build-up at the material interfaces is severe and requires extreme maintenance measures. In addition, the SRIM process requires a liquid tight seal around the entire perimeter of the trim panel. This is achieved by using the cladding layer which must cover the total area of the cavity with adequate runouts to seal against. This liquid tight requirement also precludes the possibility of running the mold in a vertical position as is the case with steam chest processing.
[0020] All references cited herein are incorporated herein by reference in their entireties.
BRIEF SUMMARY OF THE INVENTION
[0021] Specifically, the present invention relates to a steam chest molding process using, for example, a foamable material such as a solid, pre-expanded polyolefin bead, e.g., expanded polypropylene (EPP) or expanded polyethylene (EPE), which is conveyed into a mold cavity behind a laminating material, i.e., a cladding layer. The present invention encompasses the need to perform many functions of laminated trim panel production in an initial molding step to eliminate as many post molding operations as possible. The elimination of these post-molding operations along with the labor and materials required to perform them is viewed as a significant advantage over current state of the art EPP and EPE molding capability. Among the tool functions featured in the molding process to which this invention will pertain are the ability to mold partially clad products, the ability to perform perimeter edge folding, and the ability to perform perimeter trimming of cladding layer. Molding, including folding and trimming of the cladding layer is accomplished without the need for post mold secondary operations. These improvements are associated with a number of process specific variables in the molding process. Among these are the ability to use vertical platens in the molding machines, the use of a shear edge shut-off in the molds to accommodate crush filling (a process by which the mold is partially closed, filled with expanded foamable material, and closed), thereby partially crushing the foamable materials, and the fact that the molding material is molded in the solid state as opposed to the liquid state typical of most other molding processes associated with the manufacture of the parts of the type described herein.
[0022] The present invention includes a mold apparatus and method for forming a shaped laminate in one step where the laminate includes a cladding layer and a foam backing layer. The apparatus includes a male mold half matable to a female mold half that define a mold cavity. An inlet is mounted on the mold apparatus for introducing foamable materials, such as solid, partially expanded resin, into the mold cavity. Edge folding members, carried by one of the mold halves, movable from a retracted position to an extended position, fold the cladding layer over at least part of the edge of the foam backing layer. Trim blades are located adjacent to the edge folding members movable from a retracted position adjacent the cavity to an extended position engaging the other mold half to sever the cladding layer to define the finished shape of the laminate. At least one driver, such as a mechanical, pneumatic, or hydraulic actuator, for opening and closing the mold halves and for moving the edge folding members from the retracted position to the extended position is provided.
[0023] Each of the trim blades may be movably mounted on one of the edge folding members. Each of the edge folding members is preferably inwardly movable by an edge folding member actuator. The edge folding member actuators may be hydraulically, or pneumatically operated or by a camming action of a camming surface on heel blocks located on one of the mold halves against a camming surface on corresponding edge folding members on the other mold half. Folding of the cladding layer over the foam backing layer thereby occurs. A biasing means, such as springs, may be associated with each edge folding member to return it to a retracted position upon mold opening after completion of the molding process. Preferably, each edge folding member is slidably mounted on one of the mold halves, such that closing of the mold halves with respect to one another causes the camming surfaces on the heel blocks and the camming surfaces on the edge folding members to engage to move the edge folding members upon mold closure. The heel blocks are preferably located on the male mold half whereby movement of the male mold half into the female mold half causes the camming action to move the edgefold slide inwardly to fold the cladding layer over the foam backing layer.
[0024] The foamable materials may be solid, partially expanded resin and may preferably be pre-expanded polypropylene beads or pre-expanded polystyrene beads. The mold apparatus preferably is adapted to perform a steam-chest molding process. The cladding layer is a preferably a layer of a textile, a thermoplastic polyolefin sheet, or a polyvinylchloride sheet. The cladding layer may have a backing material of, for example, crosslinked polypropylene, thermoplastic polyolefin, or polypropylene bonded to it prior to being molded in the mold apparatus. The cladding layer may be a bilaminate, a trilaminate, or other multilayer laminate. The male mold half and the female mold half may be oriented with their openings preferably in a vertical plane, but may be oriented on a horizontal or other plane. A crush fill process may be used with the present invention.
[0025] Preferably, the drivers includes a hydraulic cylinder for opening and closing the mold halves and hydraulic cylinders for moving the trim blades. Optionally, adjacent trim blades overlap one another and are adapted to be sequenced to trim adjacent edges of the cladding layers in alternating movements to allow overlapping of the trim blades at the male mold cutting surface thereby facilitating a complete separation of excess cladding layer.
[0026] The molding apparatus may receive a cladding layer that fully covers or partially covers a surface of the foam backing layer.
[0027] The molding apparatus may include compression pins and cores, carried by the male mold half, moveable by a compression pin actuator in the direction of die draw to a position adjacent the female mold half, to compress the cladding layer onto the female mold half. The cladding layer is thereby sealed against the female mold to prevent the foamable materials from migrating under the cladding. The compression pin actuator may be mechanical, pneumatic, or hydraulic. The molding apparatus may include an air compressor to compress the foamable materials during the introduction of the foamable materials into the mold cavity.
[0028] A method for forming the shaped laminate in a single step is also provided using the above apparatus. The edge folding members and the trim blades are moved to retracted positions using a driver. The cladding layer is loaded onto surfaces of the edge folding members adjacent the female mold half. The female mold is then closed with respect to the male mold half, using a driver, to form the mold cavity. The mold cavity is filled, through the inlet, with the foamable materials. Preferably, the steam chest process is used to fuse the foamable materials. Each edge fold slide is actuated, using a driver, to the extended position to fold the cladding layer over at least part of the edge of the foam backing layer. Each of the trim blades is actuated to the extended position engaging the other mold half to sever the cladding layer to define the finished shape of the laminate, and then actuated back to the retracted position. The female mold half is then opened with respect to the male mold half to withdraw the finished shaped laminate.
[0029] Optionally, the mold halves may be partially closed, the mold cavity is filled, and then the mold halves are fully closed the molds to further crush and densify the foamable material aiding to fuse and homogeneous fill the mold cavity.
[0030] Optionally, a sequentially moving adjacent trim blades may be included. Here, the trim blades overlap one another to trim adjacent edges of the cladding layers in alternating movements. This allows overlapping of the trim blades thereby facilitating a complete separation of excess cladding layer may also be included.
[0031] The method may include compressing the cladding layer onto the female mold using the compression pins to seal the cladding layer against the female mold to prevent the foamable materials from migrating under the cladding.
[0032] The method may include the step of filling the mold cavity with prepressurized foamable materials, i.e. beads having an increased internal air pressure.
[0033] Finally, the method may include the step of providing an air compressor and the step of compressing the foamable materials with the air compressor as part of the step of filling the mold cavity with the foamable materials such that the foamable materials are pre-compressed in the mold cavity.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0034] The invention will be described in conjunction with the following drawings in which like reference numerals designate like elements and wherein:
[0035] [0035]FIG. 1 is a simplified plan view of a female mold half of a mold apparatus in accordance with one preferred embodiment of the present invention, having a cladding layer placed thereon, shown prior to molding.
[0036] [0036]FIG. 1A is an enlarged, partial plan view of the female mold half of the mold apparatus of in FIG. 1, depicting the cladding layer prior to molding and the shaped laminate subsequent to molding.
[0037] [0037]FIG. 2 is a sectional view of the mold apparatus of FIG. 1, taken substantially along lines 2 - 2 of FIG. 1, shown with the female mold in a position prior to molding.
[0038] [0038]FIG. 3 is a sectional view of the mold apparatus of FIG. 1, shown with compression pins and cores in an extended position and shown prior to molding.
[0039] [0039]FIG. 4 is a sectional view of the mold apparatus of FIG. 1, illustrating the mold subsequent to partial closure for crush filling, in a position to accept bead material for and foam injection.
[0040] [0040]FIG. 5 is a sectional view of the mold apparatus of FIG. 1, illustrating the mold subsequent to full closure (i.e., subsequent to crush filling) and illustrating a folding member in a position where the cladding layer is folded over the foam backing layer created during the molding operation, and illustrated prior to extension of a cutting blade carrier.
[0041] [0041]FIG. 5A is an enlarged view of “FIG. 5A” as depicted in FIG. 5.
[0042] [0042]FIG. 6 is a sectional view of the mold apparatus of FIG. 1, illustrating the mold subsequent to full closure and illustrating the folding member in a position where the cladding layer is folded over the foam backing layer created during the molding operation and the cutting blade is in an extended position, with the cutting blade in a final trim position.
[0043] [0043]FIG. 6A is an enlarged view of “FIG. 6A” as depicted in FIG. 6.
[0044] [0044]FIG. 7 is a top, perspective view of a simplified shaped laminate produced by the mold apparatus of the present invention using the method for one step steam chest molding of the present invention.
[0045] [0045]FIG. 8 is a bottom perspective view of the shaped laminate of FIG. 7.
[0046] [0046]FIG. 9 is a partial cross sectional view of the shaped laminate of FIG. 7, taken substantially along lines 9 - 9 of FIG. 8.
[0047] [0047]FIG. 10 is a partial cross sectional view of the shaped laminate of FIG. 7, taken substantially along lines 10 - 10 of FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
[0048] Referring now to the drawing figures wherein like reference numbers refer to like elements throughout the several views, there is shown in FIGS. 1 - 6 A a mold apparatus for one step steam chest molding 10 in accordance with one preferred embodiment of the present invention.
[0049] As can be seen, for example, in FIGS. 2 and 3, the mold apparatus 10 includes a male mold half 12 , a female mold half 14 , and at least one inlet 16 mounted on the mold apparatus 10 , preferably on the male mold half 12 , for introducing foamable materials 18 into a mold cavity 20 formed by the male mold half 12 and the female mold half 14 (see FIG. 5).
[0050] As can be seen in FIG. 1, a sheet of cladding material, cladding layer 22 , i.e., a foil as known in the art, is loaded onto a plurality of retaining pins 24 . Retaining pins 24 hold the cladding layer 22 firmly above the female mold half 14 , over the portion of the mold (or over all of the mold) where the cladding layer 22 is desired. Staggered around the perimeter of the female mold half 14 are a series of edge folding members 26 , also known as edgefold slides. The retaining pins 24 are preferably mounted to the upper surface of the edge folding members 26 .
[0051] The cladding layer 22 may be, for example, thermoplastic polyolefin (TPO) sheet, polyvinylchloride (PVC) sheet, a textile, or other cladding material and may or may not have back side laminates such as crosslinked polypropylene (XLPP), TPO, or polypropylene bonded to it. The cladding layer 22 may be constructed, for example, as a single layer skin (a “compact” layer as known in the art), as a bilaminate (for example, a compact layer with a crosslinked polyolefin foam), as a trilaminate (for example, a compact layer with crosslinked polyolefin foam plus a back compact layer), or as another appropriate multilayer laminate.
[0052] Once the cladding layer 22 is properly positioned, as seen in FIGS. 1 and 2, the male mold half 12 moves (downwardly in the figures) towards the female mold half 14 . As can be seen in FIGS. 3 and 4, compression pins 28 and compression cores 30 are located on the male mold half 12 . These pins 28 and cores 30 contact the cladding layer 22 and press it against the female mold half 14 (FIG. 4) to prevent migration of the foamable materials 18 (i.e., the beads) to the front side of the panel being formed, i.e., to prevent bead migration on the female mold half 14 side of the cladding layer 22 .
[0053] [0053]FIG. 3 shows the mold apparatus 10 partially closed with the spring loaded compression pins 28 and compression cores 30 in position to contact the cladding layer 22 . The compression pins 28 and cores 30 are positioned, when extended, to press the cladding layer 22 against the female mold half 14 , as can be seen in FIG. 4. The compression pins 28 and cores 30 are actuated by at least one compression pin and core actuator (not shown) which may be springs, pneumatic cylinders, hydraulic cylinders, or other mechanical actuator to establish contact of the pins 28 and cores 30 with the cladding material 22 .
[0054] [0054]FIG. 4 shows the mold in the mold fill position at the point where a “crush fill” is required, if desired. In a crush fill mode, the mold cavity is filled with foamable material 18 , made from, e.g., EPP, while in a position prior to full close. This allows the foamable material 18 to be further compressed upon fully closing the mold. When in this position, preferably, the compression pins 28 and cores 30 abut the cladding material 22 to prevent bead migration. This method of molding aids in bead fusion to each other and bead fusion to the cladding material 22 , better mold fill characteristics, better density control, and final forming of the cladding material 22 to the female mold half 12 surface. Crush filling is not required in every molding case and its need is dictated by product geometry, density requirements, cladding material characteristics, and other process variables.
[0055] In order to facilitate crush filling, the mold must be constructed with a shear edge seal 42 , for example, approximately 25 mm in depth, and continuing around the perimeter of the male mold half 12 . The shear edge seal 42 is necessary to confine the foamable material 18 to the mold cavity 20 as the filling cycle takes place and also, preferably, is used as a cutting surface. The shear edge seal 42 in this case is a machined two-part band. A lower mold seal is a separate machined aluminum detail but could be integrated into the male tool. An upper seal also acts as a cutting surface which is contacted by the trim blades 32 when the trim takes place around the perimeter 54 of the foam backing layer 52 formed in the mold process (see FIGS. 7 - 10 ). This shear edge seal 42 is machined from a heat resistant resin material which could be any material commonly used as cutting surfaces such as polypropylene, nylon, polyurethane, aluminum, or stainless steel. These seals 42 have enough land in the die draw plane to allow the male and female tools to mate prior to full close to provide the ability to “crush fill” the cavity.
[0056] [0056]FIG. 4 shows the mold apparatus 10 in the partially closed position with the cladding material 22 compressed. The edge folding members 26 are shown just prior to engagement with heel blocks 34 mounted on the male mold half 12 . Trim blade carrier slides 46 , as will be discussed below, are shown in a fully retracted position. The compression pins 28 and cores 30 are in full contact with the cladding material 22 , pressing the cladding material against the female mold half 14 .
[0057] [0057]FIGS. 5 and 5A show the mold apparatus 10 fully closed with the compression pins 29 and cores 30 still contacting the cladding material 22 and fully pressing it against the female mold half 14 . The foamable materials 18 are now compressed into their final configuration, i.e., into a foam backing layer with the cladding layer 22 integral thereto (a shaped laminate). The heel blocks 34 have also engaged the edge folding members 26 such that the edge folding members 26 have caused the cladding material to fold over the edge of the foamable material 18 , (now in the form of a foam backing layer), at the periphery of the molded article, which is now fused in a standard steam chest process.
[0058] The foamable materials 18 , i.e., the beads, may also be pressurized before the molding process to assist in the achieving of a high quality product. Here, prior to molding, the foamable materials 18 are held under pressure in a pressurized tank for an extended period of time. Over this time period, pressurized gas (e.g., air) seeps through the beads, raising the internal pressure of the gas in the beads. This extra step allows for more uniform molding and other advantages, as known in the art.
[0059] [0059]FIGS. 6 and 6A also show the mold apparatus 10 in the mold filled position subsequent to the position shown in FIG. 5. The trim blades 32 have been advanced to their extended positions and the cladding material 22 has been severed prior to opening of the mold apparatus 10 and subsequent part and offal removal.
[0060] The edge folding and trimming will now be discussed in greater detail. As was seen in FIGS. 1 - 3 , the mold apparatus 10 is in an open position with the cladding layer 22 in position for molding. In FIGS. 1 - 3 , as well as in FIG. 4, an edge folding member 26 can be seen in a fully retracted position. Each edge folding 26 member has a trim blade 32 associated therewith. In FIGS. 2, 3, and 4 trim blade 32 is also depicted in a fully retracted position. In FIG. 5, and in greater detail in FIG. 5A, the edge folding member 26 is depicted in an extended position with the trim blade 32 still in a retracted position. In FIG. 6, and in greater detail in FIG. 6A, the edge folding member 26 is depicted in an extended position with the trim blade 32 also in the extended position, i.e., in a position where the cladding layer 22 is cut. An edge folding member actuator moves the edge folding member from the retracted to extended position and back again, a preferred embodiment of which is described below. This actuator may be, for example, mechanical, or a pneumatic or hydraulic cylinder.
[0061] Each of the trim blades 32 is preferably mounted on a trim blade carrying slide 46 which is adapted to move from a retracted position relative to its corresponding edge folding member 26 , as shown in FIGS. 1 - 5 A, to its extended position, as shown in FIGS. 6 and 6A. Trim blade actuating devices 48 serve to slide the trim blade carrying slides 46 along with its integral trim blades 32 inwardly, in the same direction as the movement of the edge folding members 26 . The trim blade actuating devices 48 are preferably pneumatic, hydraulic or mechanical actuators that also move in the same plane as the slide or perpendicular to it. They may be mounted either on the male mold half 12 or female mold half 14 .
[0062] In the preferred embodiment, the edge folding member actuator is a plurality of heel blocks 34 , mounted on the male mold half 12 , which complement each edge folding member 26 , mounted on the female mold half 14 , which are used to move the edge folding members 26 from a fully retracted position (FIGS. 1 - 4 ) to a fully extended position (FIGS. 5 - 6 ). As the male mold half 12 is moved into position in the female mold half 14 to create the mold cavity 20 , camming surfaces 26 on each heel block 34 engage corresponding camming surfaces 38 on edge folding members 26 to begin a camming movement of the edge folding member 26 causing the edge folding member to move inward to its extended position towards the mold cavity 20 , i.e, perpendicular to the die draw. As indicated, these heal blocks 34 serve to mechanically actuate the edge folding members 26 . This action could also be initiated with, for example, pneumatic or hydraulic cylinders, and the like. Edge folding members 26 each preferably contain a trim blade 32 mounted on a trim blade carrier slide 46 . The cladding material 22 is thereby wrapped around the edge of the foamable material which is now foamed in place in the process. The trim blades 32 are then extended to their cutting positions, i.e, their extended positions, by actuating the trim blade actuating devices 48 , e.g., hydraulic cylinders, which push the trim blade carrying slides 46 forward, independently of the edge folding members 26 . The excess runout material is thereby severed from the molded product. After completion of a cooling cycle, the mold apparatus opens, i.e, the male mold half 12 is separated from the female mold half 14 and air may be used to assist in ejecting the part.
[0063] The edge folding members 26 are preferably spring loaded by springs 40 to cause the edge folding members 26 (as well as the trim blades 32 and the trim blade carrier slide 46 ) to retract to fully retracted positions once the male mold half 12 is withdrawn from the female mold half 14 at the completion of the molding process.
[0064] As can be seen in FIG. 1 and also in FIGS. 7 - 10 which show a simplified example of a shaped laminate 50 , the cladding layer 22 may cover the entire surface adjacent to the female mold half 14 of the shaped laminate 50 , i.e., cover the entire foam backing layer 52 , or the cladding layer 22 may cover any portion of the foam backing layer 52 , for example, about one half of the part, as actually shown in FIGS. 7 - 10 . If the cladding layer 22 covers the entire foam backing layer 52 , no compression pins 28 and compression cores 30 are necessary.
[0065] [0065]FIG. 1A depicts an alternate embodiment of a mold apparatus 10 ′ of the present invention. Here, adjacent edge folding members 26 ′ have trim blades that overlap one another at, for example, point X. Here, by appropriate selection of camming devices, the edge folding members 26 ′ are adapted to be sequenced to trim adjacent edges of the cladding layers in alternating movements to allow overlapping of the trim blades thereby facilitating a complete separation of excess cladding layer.
[0066] [0066]FIG. 1A also generally depicts the steps in the process wherein section A depicts the cladding material 22 ′ in place over the female mold half 14 ′, section B depicts the cladding material 22 ′ in place within the female mold half 14 ′, and section C depicts the mold apparatus 10 ′ in its final molding position and the cladding material 22 ′ being cut with alternating overlapping trim blades.
[0067] Trim panels manufactured using this process may include, for example, instrument panels, door trim panels, consoles, rear window trim panels, and garnish moldings which consist of a partial or complete cladding of, for example, a textile, a TPO, or a PVC. All listed cladding layers can have backing material such as XLPP, TPO, or polypropylene bonded to them prior to being back molded with EPP or EPE in the molding process.
[0068] The tactile characteristics of trim panels molded in the lower densities can be compared to those produced using a foam-in-place process which yields a fully clad, soft to touch part with generous return flanges commonly used in instrument panel production but with much higher labor, tooling, and investment content.
[0069] Finally, optionally, the filling of the mold cavity 20 may be accomplished using compressed air. The pressure used, for example, a pressure above atmospheric of from 0.5 to 5 bar, causes compression of the particles. By varying the pressure, different fill amounts per volume unit can be introduced into the mold cavity 20 . The chamber is then decompressed wherein the particles attempt to expand again and pack against one another in such a manner that virtually no movement of materials in the mold occurs. After the filling operation, the mold is heated using steam or hot air so that the foam particles soften, expand and weld to one another.
[0070] While the 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.
|
A mold apparatus and method for forming a shaped laminate in one step are provided where the laminate includes a cladding layer and a foam backing layer. The apparatus includes a male mold half matable to a female mold half that define a mold cavity. An inlet is mounted on the mold apparatus for introducing foamable materials into the mold cavity. Edge folding members, carried by one of the mold halves, movable from a retracted position to an extended position, fold the cladding layer over at least part of the edge of the foam backing layer. Trim blades are located adjacent to the edge folding members movable from a retracted position adjacent the cavity to an extended position engaging the other mold half to sever the cladding layer to define the finished shape of the laminate.
| 8
|
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/431,888 filed Dec. 6, 2002.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of carbon nanotubes. More particularly, the invention relates to mass-produced coiled carbon nanotubes and to a method for their synthesis using microwave chemical vapor deposition (CVD).
BACKGROUND OF THE INVENTION
[0003] Prior art methods of catalytic chemical vapor deposition (CCVD) have been used to prepare carbon fibers/tubules with different morphologies in different sizes. Among them, fibrous carbon materials with coil morphology have especially attracted a wide interest. This interest relates not only to academic research interests but also to potential versatile commercial applications. Motojima et al. first reported regular coiled carbon fibers in micron size by CCVD with thiopene vapor as an impurity gas, named carbon microcoils [Motojima S. et al., “Preperation of coiled carbon fiders by pyrolysis of acetylene using a Ni catalyst and sulfur or phosphorus compound impurity” Appl. Phys. Lett. 62 2322-3, 1993]. In this paper, the growth mechanism of carbon microcoils was postulated as resulting from the anisotropic properties of the catalyst for carbon deposition. Such carbon microcoils found applications in EM absorbers, micro springs, etc. Subsequently, Pan et al. reported the synthesis of carbon tubule nanocoils using iron-coated indium tin oxide as a catalyst [Pan L. et al., “Growth and density control of carbon tubule nanocoils using catalyst of iron compounds” J. Mater. Res. 17 145-8, 2001]. Recently, Varadan et al. synthesized carbon nanocoil fibers by using Ni particles [V. K. Varadan, J. Xie, “Synthesis of carbon nanocoils by microwave CVD” Smart Materials and Structures, 11 728-34, 2002]. Such nanocoiled carbon fibers/tubules have been shown to be good candidates for commercial applications, especially field emission display technology [Pan L. et al., “Field emission properties of carbon tubule nanocoils” Jpn. J. Appl. Phys. 40 L235-7, 2001]. Note that all of the coiled carbon fibers/tubules mentioned above are prepared using amorphous carbon materials.
[0004] In contrast to the conventional method of producing carbon nanocoils, the present invention relates to coiled carbon nanotubes. Since the discovery of carbon nanotubes by Iijima, coiled carbon nanotubes have become objects of widespread interest. The primary difference between coiled carbon nanotubes and carbon nanocoils lies in the crystalline graphitic structures of the nanotubes. Also, the diameter of coiled carbon nanotubes (<100 nm) is much smaller than the diameter of carbon nanocoils. The coil morphology, together with as well as the extraordinary properties of nanotubes, make coiled carbon nanotubes a promising material for hydrogen storage, field emission, EM absorber and nanotechnology applications in general.
[0005] Nanotubes prepared from CCVD methods tend to be produced in straight or randomly curled morphologies. For example, accidentally coiled carbon nanotubes were reported in extremely low yield by Hernadi et al. [“Fe-catalyzed carbon nanotube formation” Carbon 34 1249-57, 1996]. Also, Amelinckx et al. reported a formation mechanism for catalytically grown helix-shaped graphite nanotubes [“A formation mechanism for catalytically grown helix-shaped graphite nanotubes” Science 265 635-9, 1994]. According to their results, the coil morphology of carbon nanotubes is due to the mismatch between the extrusion velocity and the rate of carbon deposition.
[0006] Thus far the synthesis of coiled CNT has been reported as a byproduct of regular CNT synthesis. It would be more accurate to say that coiled CNTs have been found under microscope by accident because there was no control for the synthesis of coiled CNT. To date, neither specific process conditions nor special catalyst compositions have been identified for the effective and consistent synthesis of coiled CNTs. Despite the early indications of the usefulness of coiled CNTs, there continues to be a strong need for the effective synthesis of regular coiled carbon nanotubes.
[0007] CNTs, along with coiled carbon nanotubes, are the most promising materials anticipated to impact future nanoscience and nanotechnology. Their unique structural and electronic properties have generated great interest for use in a broad range of nanodevices. A significant amount of work has been done in the past decade to reveal the unique structural, electrical, mechanical, electromechanical and chemical properties of carbon nanotubes and to explore the key applications of this novel material. Most of these applications will require efficient fabrication methods capable of producing pure CNTs, including coiled carbon nanotubes, to meet device requirements. Another advantage of coiled carbon nanotubes is that they are capable of forming in situ semiconductor-metallic or semiconductor-insulator junctions which one can utilize for the fabrication of nanodevices. Coiled carbon nanotubes also have an greater surface area than CNTS which increases their functionalization. Accordingly it is an object of the present invention to provide effective and efficient methods of fabricating CNTs, especially coiled carbon nanotubes, to enable the commercialization of applications using such.
SUMMARY OF THE INVENTION
[0008] The invention is a method for synthesizing coiled carbon nanotubes using a microwave CVD system with inventive processing conditions and specialized catalyst(s). Preferred conditions include the use of acetylene as a hydrocarbon source gas in a microwave CVD system without using an impurity gas and using an iron supported on magnesium carbonate as a catalyst. The invention also includes the resulting coiled carbon nanotubes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 shows a schematic diagram of a conventional thermal filament CVD system.
[0010] [0010]FIG. 2 shows a schematic diagram of a microwave CVD system used in the present invention.
[0011] [0011]FIG. 3 shows an illustration of a coiled carbon nanotube.
[0012] [0012]FIG. 4 shows a flow diagram for the flow control systems.
[0013] [0013]FIG. 5 shows a SEM micrograph of coiled nanotube synthesized using a microwave CVD system in accordance with the present invention.
[0014] [0014]FIG. 6 shows a TEM image of coiled nanotubes obtained from a microwave CVD system in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Referring now to FIG. 1, an apparatus designed to perform this method is designated in its entirety by the reference numeral 8 . The method generally involves placing a catalyst 3 inside of a reaction chamber 1 and then heating up the reaction chamber 1 . In one embodiment of the method, a quartz reaction tube 2 is used to transport the catalyst in and out of the reaction chamber 1 . The temperature is monitored by a thermocouple 7 . When the temperature inside has reached a certain level (usually 700° C.) a hydrocarbon source gas 4 (such as acetylene) is pumped into the reaction chamber 1 through a intake valve. The hydrocarbon source gas 4 is then broken down into its elements which interact with the catalyst 3 resulting in the growth of carbon nanotubes. The exhaust gas 6 is removed from the reaction chamber 1 . In one embodiment of this method, argon 5 is pumped into the reaction chamber 1 for purging.
[0016] [0016]FIG. 2 shows a microwave CVD system 9 according to a preferred embodiment of the present invention. Until now, this method has involved the use of a furnace to heat the reaction chamber 33 . The present invention uses a magnetron 10 in place of a furnace. Although a magnetron 10 capable of producing 750 W is preferred, any commercially-available magnetron may be used. The magnetron 10 creates a microwave field inside the reaction chamber 33 .
[0017] In the preferred method of the invention, a known amount of the catalyst and catalyst support 15 are dispersed onto the substrate 34 . The substrate 34 is then loaded into the reaction chamber 33 . In this embodiment, the substrate 34 is loaded in and out of the reaction chamber 33 in a quartz container 19 . The magnetron 10 is then switched on to heat the substrate 34 to the reaction temperature. In this embodiment, the reaction temperature is set to 700° C. During heating, an inert gas 22 , at an optimized flow rate, can be used for purging, although the use of an inert gas 22 is not required for the present invention. When the reaction temperature is reached, a hydrocarbon source gas 21 is introduced into the reaction chamber at an optimal flow rate. The gases are pumped into the reaction chamber 33 through the gas inlet 17 and blown onto the substrate 34 using a quartz gas distributor 16 . Exhaust gas leaves the chamber through the gas outlet 18 . In this embodiment the reaction is set to 30 minutes. After the reaction, the resulting product is scratched from the substrate. Previous experiments by Varadan, V. et al. [“Synthesis of carbon nanocoils by microwave CVD” Smart. Mater. Struct. 11 (2002) 728-734] did not involve the production of carbon nanocoils, and utilized different processing materials and conditions than described in the present invention.
[0018] The advantage of using a microwave field is that it is uniform throughout the reaction chamber 33 . This uniform field allows for a higher quantity of coiled carbon nanotubes with consistent properties to be produced during each reaction. In addition, a microwave field can be instantly turned off whereas a reaction chamber heated by a furnace must be allowed to cool to room temperature before any nanotubes can be extracted. This dramatically reduces the lag time between production rounds. In the preferred embodiment of the invention, a commercially available stub tuner 12 is used prevent any reflected power from flowing into the magnetron 10 . In one example, the inventors manually adjusted the stub tuner 12 . In another example, a commercially available three-port circulator 13 was used to automatically adjust the stub tuner 12 . In addition, the invention may comprise a circulating chiller 14 which cools the magnetron 10 and therefore extends its life. The invention may further comprise a stirrer 27 , which assists in making the microwave field uniform. The stirrer 27 is driven by a motor 28 .
[0019] The reaction chamber 33 can be made from any number of materials without departing from the scope of the present invention. For instance, in one embodiment the reaction chamber is constructed out of aluminum. In a further embodiment, the reaction chamber is made of steel. In the preferred embodiment, the reaction chamber is a cylinder. The inventors used two reaction chambers manufactured by HVS Technologies. The smaller reaction chamber had dimensions of 14″ in length and 5.75″ in diameter. The larger reaction chamber had dimensions of 70″ in length and 35″ in diameter.
[0020] Although the catalyst can be made from various materials without departing from the scope of the present invention, a preferred catalyst is iron. Iron is preferred because it produces the highest yield of coiled carbon nanotubes. Alternatively, other transition metal catalysts can be used; including combinations of transition metals (e.g., bimetallic catalysts). It is important to note here that the indium-tin-iron catalyst disclosed in U.S. Pat. No. 6,583,085 to Nakayama et al. is not preferred for this invention. The presence of tin in the catalyst would cause the catalyst to spark when placed in the microwave field. In addition, the indium-tin-iron catalyst would not be preferred does not easily absorb the microwaves.
[0021] The specific support used in the method of the present invention is critical. The support must contain pores giving rise to the growth of coiled carbon nanotubes according to the invention as opposed to other formations, such as fibers. The supports must also be able to easily absorb microwaves. Some non-limiting examples include silica, zeolite, and magnesium carbonate (preferred). Preferred pore sizes lie in the range of 0.1 to 10 nm with a surface area of 250-300 m×m/g. The following are three examples of catalyst supports and catalysts with which they were combined (being just three examples of “supported metal catalyst”).
EXAMPLES
[0022] Catalyst and Catalyst Support #1
[0023] Iron nitrate and magnesium carbonate were weighed 1:1 weight ratio. Iron nitrate was dissolved in water and the resulting solution was added to magnesium carbonate, followed by continuous stirring to obtain a semi-solid mixture. The semi-solid mixture was kept inside an overnight at 500° C. After allowing the mixture to cool to room temperature, the resulting brown color solid was powdered. While the pole size of the magnesium carbonated varied somewhat throughout its surface, a majority were 10 nm in diameter.
[0024] Catalyst and Catalyst Support #2
[0025] Iron nitrate and silica were weighed 1:1 weight ratio. Iron nitrate was dissolved in water and the resulting solution was added to silica, followed by continuous stirring to obtain a semi-solid mixture. The semi-solid mixture was kept inside an oven at 120° C. overnight. After allowing the mixture to cool to room temperature, the resulting brown color solid was powdered. As a porous substance, the pore sizes for silica varied throughout its length.
[0026] Catalyst and Catalyst Support #3
[0027] The inventors used “hydrothermal processing” to manufacture zeolite (although commercial grade zeolite may be used). The hydrothermal processing method is described in Cundy, C. et al. [“The Hydrothermal Synthesis of Zeolites: History and Development from the Earliest Days to the Present Time” Chem. Rev. 2003, 103, 663-701] Nickel acetate was dissolved in water and a proper amount of zeolite was added into the solution with a Ni percentage in zeolite of 14.5 wt %. The gel solution was stirred and kept in an oven at 120° C. overnight. After drying, the solid was crushed into a fine powder. While the pore size for zeolite varied throughout its surface, the majority were 1 nm in diameter.
[0028] The substrate 34 is made of silicon carbide. Although the hydrocarbon source gas 21 can be any gas containing carbon, in the preferred embodiment the hydrocarbon source gas is acetylene. The inventors found that the optimal flow rate for acetylene is 30 sccm for the smaller reaction chamber (14″×5.75″) and 600 sccm for the larger one (70″×35″). Other non-limiting examples include methane, ethane and propane.
[0029] When an inert gas 22 is also used as described herein, helium is preferred, although any inert gas can be used (such as argon). The inventors found the optimal flow rate for helium is 190 sccm for the smaller reaction chamber and 3500 sccm for the larger one. It is important to mention here that for the synthesis of coiled carbon nanotubes by a conventional CCVD method, the presence of an impurity gas (e.g. thiophene) is necessary, while in the microwave CVD method, no impurity gas is required.
[0030] To optimize the processing conditions, the temperature of the reaction chamber 33 and the gas flow rates can be monitored by a computer 26 . FIG. 4 is a software flow chart for the flow control systems. The temperature of the reaction chamber 33 is monitored by a pyrometer 23 , which in the preferred embodiment is an optical pyrometer 25 . The temperature readings taken by the pyrometer 23 are transmitted to a computer 26 . The computer 26 then compares the temperature of the reaction chamber 33 with the set temperature for processing (preferably 700° C.). The computer 26 then controls the switching power supply 11 which in turn controls the magnetron 10 . If the reaction chamber temperature is too low, the computer 26 will tell the switching power supply 11 to turn on the magnetron 10 and increase the temperature. If the reaction chamber temperature is too low, the computer 26 will tell the switching power supply 11 to turn off the magnetron 10 . The computer 26 also communicates with the master flow controller 20 which controls the mass flow controllers 24 . The mass flow controllers 24 control the flow rates of the inert 22 and hydrocarbon source gas 21 .
[0031] An illustration of a coiled carbon nanotube is shown in FIG. 3. The distance between the coils is substantially uniform throughout the length of each coiled carbon nanotube. In addition, the diameter of each coiled carbon nanotube will also be substantially uniform. The coiled carbon nanotube 29 is composed of carbon rings in the shapes of pentagons 32 , hexagons 30 , and heptagons 31 . Depositing the various shapes in specific locations along the surface of the carbon nanotube causes the carbon nanotube to assume a coiled shape. Depending upon the distance between the coils, the non-hexagonal/hexagonal ratio of the carbon rings ranges from 0.1:1 to 1:1. A non-hexagonal/hexagonal ratio of 0.1 produces a “loose” coil with a large pitch. A non-hexagonal/hexagonal ratio of 1:1 produces a “tight” coil with a small pitch. The exact morphology of coiled carbon nanotubes will depend on the catalyst/catalyst support that is used and the conditions of the microwave CVD.
[0032] A scanning electron microscope (SEM 3000N manufactured by Hitachi) was used to investigate the morphology of the coiled carbon nanotubes. Due to the conducting property of carbon nanotubes, no gold coating is necessary for SEM operation. A transmission electron microscope (TEM 420T manufactured by Philips) was used to study the nanostructure of the coiled carbon nanotubes. TEM samples were prepared by ultrasonic vibration of a small amount of material in acetone followed by dropping on a TEM grid (Lacey carbon film on 300 mesh copper grid, Electron Microscopy Science).
[0033] In the SEM micrograph shown in FIG. 5, the coiled morphology for the microwave CVD samples is clearly revealed. From the TEM micrograph shown in FIG. 6, the hollow structure as well as coiled morphology for the microwave CVD samples was confirmed.
[0034] Under optimized conditions, the inventors have achieved ˜90% yield of coiled carbon nanotubes. While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various alterations in form and detail may be made therein without departing from the spirit and scope of the invention. In particular, the particular metal catalysts, supports, source gas, and flow rates used can vary significantly and still be within the optimization scope of the present invention.
|
The present invention provides a coiled carbon nanotube and a method for its manufacture. The coiled carbon nanotube comprises a specific non-hexagonal/hexagonal carbon ring ratio, a specific pitch, and a specific diameter. The invention employs a microwave chemical vapor disposition system with novel processing conditions and specialized catalysts to synthesize the coiled carbon nanotubes.
| 3
|
FIELD OF THE INVENTION
The present invention relates to a print control apparatus and method for performing print control concerning booklet printing and, more particularly, to a print control apparatus and method for performing print control concerning booklet printing in a system constituted by an information processing apparatus such as a personal computer and an output apparatus such as a printer.
BACKGROUND OF THE INVENTION
With the development of recent computer technologies, the performance of computers have improved, and printing apparatuses are equipped with various functions under the control of the computer. As a function of the printing apparatus, a booklet printing function has become available.
When, however, booklet printing is designated by an application program running on a computer to execute printing, a conventional printing apparatus does not perform any special control for one booklet in booklet printing. For example, to print a booklet with a different type of paper (e.g., colored paper) for the cover from that for the body, the user must perform special operation.
For example, the user separately prints a cover and body, and binds them after printing. Alternatively, the user sets one cover paper sheet on the top of a printer cassette having body paper sheets, and immediately prints the cover and body at the same time.
In a case wherein the printer performs saddle stitch in booklet printing, the cover and body of a booklet must be stapled, so that the user must execute the latter operation.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the conventional drawbacks, and has as its object to designate a paper feed selection for the cover of the booklet separately from the body, and enable printing out a booklet with a cover desired by the user without any cumbersome user operation.
It is another object of the present invention to provide a print control apparatus and method capable of automatically determining limitations caused by the hardware of the printing apparatus and limitations caused by designating different paper feed selections for the cover and body of a booklet to print the booklet, and explicitly indicating to the user whether or not booklet printing with a designated cover is possible.
It is still another object of the present invention to provide a print control apparatus and method capable of preparing a means for allowing the user to designate whether or not to print data on the cover and back pages of the cover of a booklet, and satisfying various booklet printing needs of the user.
To achieve the above objects, a print control apparatus capable of performing print control concerning booklet printing, comprises acquisition means for acquiring information for determining whether or not booklet cover printing is enabled, notifying means for notifying a user that booklet printing is disabled when booklet printing is disabled, determination means for determining whether or not a cover can be designated in booklet printing on the basis of the information acquired by the acquisition means, and setting means for setting a paper feed selection for a cover of a booklet by the user separately from other pages.
To achieve the above objects, the print control apparatus further comprises cover printing designation means for designating by the user whether or not to print data on the cover of the booklet, or back page printing designation means for designating by the user whether or not to print data on a back page of the cover of the booklet.
To achieve the above objects, a print control apparatus for performing print control concerning booklet printing, comprises means for determining whether or not a cover can be designated in booklet printing on the basis of information for determining whether or not acquired booklet cover printing is enabled, when booklet printing is disabled, notifying a user that booklet printing is disabled, and allowing the user to set a paper feed selection for a cover of a booklet separately from other pages.
To achieve the above objects, a print control method in a print control apparatus for performing print control concerning booklet printing, comprises the step of designating a paper feed selection for a cover of a booklet separately from a body, and enabling printing out the booklet with a cover desired by an operator.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram for explaining the arrangement of a printer control system according to the first embodiment of the present invention;
FIG. 2 is a block diagram showing typical printing processing in a host computer according to the first embodiment;
FIG. 3 is a flowchart showing booklet printing setting processing according to the first embodiment;
FIG. 4 is a flowchart showing booklet printing execution processing according to the first embodiment;
FIG. 5 is a flowchart showing booklet printing execution processing according to the second embodiment of the present invention;
FIG. 6 shows a memory map when a printing program in the first embodiment becomes executable after being loaded to the RAM of the host computer;
FIG. 7 shows a display window example when a booklet cover printing function is selected in the first embodiment;
FIG. 8 is for explaining designation of a paper feed selection for the cover on the display window shown in FIG. 7 according to the first embodiment;
FIG. 9 is for explaining designation of a paper feed selection for the body on the display window shown in FIG. 7 according to the first embodiment;
FIG. 10 shows a display window example after the paper feed selection is set in the first embodiment;
FIG. 11 shows a display example of a selection window for 1-sided printing/2-sided printing/booklet printing in booklet printing according to the first embodiment;
FIG. 12 shows a display example of a setting window shifted when booklet printing is validated in booklet printing according to the first embodiment;
FIG. 13 is a view showing a display example of a selection window for instructing printing by the booklet function in booklet printing according to the first embodiment,
FIG. 14 shows an example of a message notifying the user that booklet cover printing is invalid in the first embodiment; and
FIG. 15 shows a display example of a selection window for setting whether or not to print data on the cover and back pages of the cover in booklet printing according to the second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the present invention can be applied to a single device, a system constituted by a plurality of devices, or a system which performs processing while being connected via a network such as a LAN or WAN as far as the functions of the present invention are executed.
[First Embodiment]
FIG. 1 is a block diagram for explaining the arrangement of a printer control system according to the first embodiment of the present invention.
In FIG. 1, reference numeral 1500 denotes a printer; and 3000 , a host computer.
The printer 1500 and host computer 3000 are connected via a predetermined bidirectional interface (interface) 21 .
The host computer 3000 comprises a CPU 1 for executing document processing for figures, images, characters, and tables (including spreadsheets and the like) based on a document processing program stored in an internal program ROM 3 b of a ROM 3 or an external memory 11 . The CPU 1 integrally controls devices connected to a system bus 4 .
The program ROM 3 b of the ROM 3 or the external memory 11 stores an operating system program (to be referred to as an “OS” hereinafter) serving as the control program of the CPU 1 . A font ROM 3 a of the ROM 3 or the external memory 11 stores font data and the like used in document processing. A data ROM 3 c of the ROM 3 or the external memory 11 stores various data used in document processing or the like.
Reference numeral 2 denotes a RAM functioning as a main memory, work area, and the like for the CPU 1 ; 5 , a keyboard controller (KBC) for controlling a key input from a keyboard 9 or a pointing device (not shown); and 6 , a CRT controller (CRTC) for controlling the display on a CRT display (CRT) 10 .
Reference numeral 7 denotes a disk controller (DKC) for controlling access to the external memory 11 for storing a boot program, various application programs, font data, user files, edit files, a printer control command generation program (to be referred to as a “printer driver” hereinafter), and the like. The external memory 11 includes a hard disk drive (HD) and floppy disk drive (FD) as standard equipment. The external memory 11 can be expanded by various storage devices such as an IC card, magnetooptical disk (MO), and CD-ROM drive.
Reference numeral 8 denotes a printer controller (PRTC) connected to the printer 1500 via the bidirectional interface 21 to execute communication control processing with the printer 1500 .
The CPU 1 executes, e.g., mapping (rasterizing) processing of an outline font to a display information RAM (not shown) set on the RAM 2 , and enables WYSIWYG on the CRT display 10 . The CPU 1 opens various registered windows and executes various data processes on the basis of commands designated with a mouse cursor (not shown) on the CRT display 10 .
In executing printing, the user can open a window concerning settings of printing to set a printer and a printing processing method for the printer driver including selection of the printing mode.
In the printer 1500 , reference numeral 12 denotes a printer CPU for outputting an image signal as output information to a printer unit (printer engine) 17 connected to a system bus 15 on the basis of a control program stored in a program ROM 13 b of a ROM 13 or a control program stored in an external memory 14 .
The program ROM 13 b of the ROM 13 stores the control program of the CPU 12 . A font ROM 13 a stores font data used in generating output information. For a printer not having any external memory 14 such as a hard disk, a data ROM 13 c stores information used on the host computer. The CPU 12 can communicate with the host computer via an input unit 18 to notify the host computer 3000 of internal information of the printer.
Reference numeral 19 denotes a RAM which functions as a main memory, work area, and the like for the CPU 12 , and can expand the memory capacity by an optional RAM connected to an expansion port (not shown). The RAM 19 is used as an output information mapping area, environment data storage area, NVRAM, and the like. The external memory 14 such as a hard disk (HDD) or IC card is access-controlled by a memory controller (MC) 20 .
The external memory 14 is connected as an option, and stores font data, emulation programs, form data, and the like. Reference numeral 1501 denotes an operation panel having operation switches, LED indicators, and the like. Note that the external memory is not limited to one, and a plurality of external memories can be used. A plurality of external memories can be connected which include an optional font card in addition to a standard font card, and store programs for interpreting the printer control languages of different language systems.
Further, the printer 1500 may use an NVRAM to store printer mode setting information from the operation panel 1501 .
FIG. 2 is a block diagram showing typical printing processes in the host computer connected to a printing apparatus such as a printer directly or via a network. In FIG. 2, an application program 201 , graphic engine 202 , printer driver 203 , and system spooler 204 are program modules existing as files stored in the external memory 11 . In execution, these files (program modules) are loaded to the RAM 2 by an OS or modules using these modules.
The application 201 and printer driver 203 can be loaded from the FD or CD-ROM of the external memory 11 or via a network (not shown) and additionally stored in the HD of the external memory 11 .
The application 201 stored in the external memory 11 is loaded to the RAM 2 and then executed. In print data from the application 201 by the printer 1500 , data is output (drawn) using the graphic engine 202 which is similarly loaded to the RAM 2 and becomes executable.
The graphic engine 202 similarly loads the printer driver 203 prepared for each printing apparatus from the external memory 11 to the RAM 2 , and converts an output from the application 201 into a printer control command using the printer driver 203 . The converted printer control command is output to the printer 1500 via the system spooler 204 loaded to the RAM 2 and the interface 21 .
Booklet print control in the first embodiment having this arrangement will be explained with reference to the flowcharts of FIGS. 3 to 5 .
Booklet printing processing in the first embodiment having the above arrangement is done under the management of an OS (Operating Systems). The user operates the keyboard controller (KBC) 5 shown in FIG. 1 to load to the RAM 2 the application program 201 for performing booklet printing processing shown in, e.g., FIGS. 3 to 5 , and activate the application program 201 . Booklet print control starts by designating a destination printer and instructing execution of printing using the activated and running application program 201 .
An example of the storage state of programs in the RAM area in executing booklet printing processing in the first embodiment is shown in FIG. 6 . FIG. 6 is a view showing a memory map when a printing program in the first embodiment becomes executable after being loaded to the RAM 2 in the host computer 3000 .
In FIG. 6, reference numeral 1101 denotes an application program storage area; 1102 , a free area of the memory; 1103 , a related data storage area necessary for processing; 1104 , a printing-related program storage area; 1105 , an OS storage area; and 1106 , a BIOS storage area. The print control program in this embodiment exists as part of the printing-related program 1104 .
As shown in the flowcharts of FIGS. 3 and 4, the processing in the first embodiment is roughly divided into two, booklet printing setting processing and booklet printing processing. Booklet printing setting processing in this embodiment will be described with reference to the flowchart of FIG. 3 .
In step S 601 , the printing-related program 1104 running on the host computer 3000 requests the printer 1500 to transmit booklet printing-related information, and acquires the booklet printing-related information of the printer 1500 .
The information acquisition method depends on the connection method between the host computer and the printer. If the host computer and printer are connected via a parallel interface (e.g., interface having centronics interface specifications), information is acquired via a bidirectional interface (e.g., bidirectional I/F such as Nibble or ECP). If the host computer and printer are connected via a network, e.g., the host computer accesses an MIB mounted on the printer via the SNMP.
In this embodiment, the information acquisition means is not limited so long as necessary information can be acquired. Detailed information acquired from the printer 1500 includes information shown in Table 1 necessary for determining whether or not booklet printing is enabled and whether or not booklet cover printing is enabled.
For example, the acquired information includes “2-sided printing?” and “the attribute of each paper feed port (paper size and convey direction)”.
TABLE 1
Booklet Cover
Prerequisite
Booklet printing
Printing
must be enabled.
Enabled?
Paper size
capable of
2-sided printing
must be selected
as printing
paper.
Constraint
Among information
condition
of the paper size
set in the paper
feed port
selected as a
paper feed
selection, the
paper size and
paper convey
direction of the
cover must be
identical to that
of the body.
Information
2-sided printing
Used to determine
Acquired
enabled/disabled?
whether or not
from
booklet printing
Printer
is enabled.
Attribute of each
Paper size and
paper feed port
convey direction.
(used to
determine whether
or not booklet
cover printing is
enabled).
Information acquired in step S 601 is not limited to the those shown in Table 1, and may appropriately change in accordance with the characteristics of the printer. In some cases, new items may be added. For example, if the printer cannot perform booklet printing for a specific type of paper, the type of paper (plain paper, OHP, or thick paper) can be added to the acquired information, and used to determine whether or not booklet printing is enabled. Information acquired from the printer is temporarily stored in the free memory 1102 shown in FIG. 6 .
Processing in the following flowchart is serial processing for an input from the user, and all processes are not executed along this flowchart. After one input processing is done, the processing returns to step S 602 and continues until the user performs all selection processes.
FIGS. 7 to 10 show display examples of the paper feed selection setting window in booklet printing according to the first embodiment. For example, if the user selects a booklet cover printing function “Different for Cover and Others” from a state in which “Same Paper for All Pages” shown in FIG. 12 is selected, the display of the setting window switches to a display window shown in FIG. 7 .
The display window in FIG. 7 allows designating a paper feed selection for the cover or body. To designate a paper feed selection for the cover or body on the window in FIG. 7, a desired paper feed selection is designated from a pull-down menu, as shown in FIG. 8 . In the example of FIG. 8, “Drawer 1 ” is designated.
As shown in FIG. 9, a desired paper feed selection for “Other Pages” as the body is designated from a pull-down display, similarly to FIG. 8 . In the example of FIG. 9, “Drawer 2 ” is designated.
A display window upon completion of settings is shown in FIG. 10 . The user confirms the settings on this display, and if the settings are proper, setting processing ends. This setting processing will be explained in detail.
If the paper feed selection for the cover or body is changed as shown in FIG. 8 or 9 , the processing shifts to step S 611 . In FIG. 8 or 9 , controls “Cover Page” and “Other Pages” for the cover and body are used to select these functions.
In step S 602 , the printing-related program 1104 determines whether or not booklet printing processing can be selected, based on 2-sided printing enable/disable information acquired in step S 601 . If YES in step S 602 , the processing shifts to step S 603 to validate selection of booklet printing, and to step S 605 .
If NO in step S 602 , the flow shifts to step S 604 to invalidate selection of booklet printing (control not to perform selection processing of booklet printing). Then, the processing advances to step S 605 . An example of a selection window for selection/non-selection of booklet printing is not shown. For example, selection of a control “Booklet Printing” shown in FIG. 11 is validated in processing of step S 603 , and invalidated in processing of step S 604 .
In step S 605 , whether or not booklet printing is selected is determined. If NO in step S 605 , the processing shifts to step S 607 . If YES in step S 605 , the flow shifts to step S 606 to validate selection of booklet cover printing, and then to step S 607 . For example, when “2-Sided Printing” shown in FIG. 11 is selected, the booklet cover printing function “Different for Cover and Others” shown in FIG. 12 cannot be selected. However, if the booklet printing function “Booklet Printing” is selected, as shown in FIG. 13, the control “Different for Cover and Others” shown in FIG. 7 can be selected.
In step S 607 , whether or not booklet cover printing is selected is checked. If NO in step S 607 , the processing advances to step S 609 . If YES in step S 607 , the processing advances to step S 608 to validate designation of paper feed selections for the cover and body, and then to step S 609 . If the user selects the booklet cover printing function “Different for Cover and Others” from a state in which “Same Paper for All Pages” shown in FIG. 12 is selected, as described above, the display window switches to the one shown in FIG. 7, allowing designating a paper feed selection for the cover or body.
In step S 609 , whether or not a paper feed selection for the cover or body is designated (changed) is checked. If NO in step S 609 , the processing shifts to step S 610 to determine whether or not selection by the user ends. If YES in step S 610 , the setting window is closed to end booklet printing setting processing.
If NO in step S 610 , the processing returns to step S 602 to continue booklet printing setting processing.
If YES in step S 609 , and the setting of a paper feed selection for the cover or body is changed as shown in FIG. 8 or 9 , the processing advances to step S 611 . In FIG. 8 or 9 , the controls “Cover Page” and “Other Pages” for the cover and body are used to select these functions.
In step S 611 , it is checked whether or not the paper feed selection for the cover or body designated (changed) in step S 609 satisfies constraint conditions of booklet cover printing. The determination method in step S 611 is based on the paper size and paper convey direction as constraint conditions used in the first embodiment shown in Table 1.
In step S 610 , the attributes of paper feed ports selected by paper feed selections for the cover and body (information temporarily stored in the free memory 1102 in step S 601 ) are compared. For example, when Drawer 1 (paper feed attribute: A4-size paper, lateral convey direction) and Drawer 2 (paper feed attribute: A4-size paper, longitudinal convey direction) are respectively selected for the cover and body, the paper sizes are the same, but the convey directions are different. Thus, booklet cover printing cannot be executed.
If NO in step S 611 , the processing shifts to step S 612 to display an error message, as shown in FIG. 14, and the changed user settings are reset to the previous ones. Then, the processing shifts to step S 602 .
If YES in step S 611 , and booklet cover printing is properly set, the flow advances to step S 613 to validate designation of a paper feed selection for the cover or body, and to step S 602 .
After selection processing by the user ends, and the user instructs execution of printing, booklet cover printing is done along the flow shown in FIG. 4 . Booklet printing setting processing in the first embodiment will be described with reference to FIG. 4 .
FIG. 4 shows an example in which the setting method of a paper feed selection in booklet printing according to the first embodiment can be set. FIGS. 10 to 13 show display examples of the display window for enabling setting of the paper feed selection in booklet printing in booklet printing setting processing in executing processing of FIG. 4 .
FIG. 11 shows a display example of a selection window for 1-sided printing/2-sided printing/booklet printing. FIG. 12 shows a display example of a setting window shifted when booklet printing is validated. FIG. 13 shows an example of instructing printing by the printing function.
In step S 801 shown in FIG. 4, print start processing is performed. The contents of print start processing are preparations for step S 802 . In step S 802 , print data from the application program is temporarily stored in units of pages in a predetermined format. The data is kept stored in units of pages until printing from the application ends. In step S 802 , data is temporarily stored in units of pages, while page rearrangement processing necessary for booklet printing is done.
Although not shown in this embodiment, a table holds temporary file names for storing each page data, and the entry order of file names is adjusted to an order matching booklet printing.
For example, when the application instructs booklet printing of 8-page data, an actual printout page order is 4, 5, 3, 6, 2, 7, 1, and 8. This page order is adopted when the host computer controls the page order in booklet printing. When the printer controls the page order, processing in this step need not be performed.
In step S 803 , whether or not print starts from the first page is checked. If NO in step S 803 , the processing shifts to step S 805 .
If YES in step S 803 , the processing shifts to step S 804 to issue a printing command representing a paper feed selection for the body and output the command to the printer 1500 . Then, the processing advances to step S 805 .
In step S 805 , whether or not print starts with the last paper sheet is determined. As the determination method, when, e.g., 8-page data are to be so printed as to include printing even on the cover and back pages of the cover, a change page number for the paper feed selection of the cover is temporarily stored in the memory 1102 during page rearrangement processing in step S 802 . Then, this number is compared in step S 805 with a page number for which processing is to start. For 8-page data, the fifth page (i.e., second page as print data from the application) meets this condition.
If YES in step S 805 , the processing shifts to step S 806 to issue a command representing a paper feed selection for the cover, and then to step S 807 . If NO in step S 805 , the processing shifts to step S 807 .
In step S 807 , whether or not printing ends is checked. If YES in step S 805 and NO in step S 807 , the processing shifts to step S 808 to perform print data generation processing (step S 808 ), and returns to step S 803 . If YES in step S 807 , printing end processing is done to end the processing. After that, print data is transmitted to the printer 1500 via the system spooler 204 shown in FIG. 2, and printed by the printer.
In the description of step S 802 , the case in which the printer 1500 controls the page order in booklet printing has been exemplified. Alternatively, when the printer 1500 has the above-mentioned booklet printing function, processes in steps S 803 to S 806 may be done only by issuing a booklet printing command. As a matter of course, the booklet printing command used in this case must use a format which allows separately designating paper feed selections for the cover and body.
After the above processing, the whole printing processing from the application ends. As a result, the processing of the printing program in the first embodiment also ends, and the OS 405 functions to delete data from the RAM 2 . In this embodiment, the medium on which the printing program is recorded is an external memory. This medium may be a flexible disk (FD), hard disk (HD) drive, CD-ROM, IC memory card, or the like. The printing program only or together with another program running on the host computer can be recorded on the ROM 3 , and constituted as part of the memory map so as to be directly executed by the CPU 1 .
As described above, the first embodiment can designate a paper feed selection for the cover of a booklet separately from the body, and print out a booklet with a cover desired by the user without any cumbersome user operation. Further, the first embodiment can automatically determine limitations caused by the hardware of the printing apparatus and limitations caused by designating different paper feed selections for the cover and body of a booklet to print the booklet, and explicitly indicate to the user whether or not booklet printing with a designated cover is possible.
[Second Embodiment]
The first embodiment always performs printing processing on cover and back pages without controlling whether or not to print data on the cover and back page of the cover. Alternatively, a display window shown in FIG. 15 may be prepared, and a control (cover page: Printing on Cover Page, back page: Insert Other page into Back Page of Cover) for setting on this display window whether or not to print data on the cover and back pages of the cover may be employed to enable the control in executing booklet printing.
The second embodiment adopting this control according to the present invention will be described with reference to FIG. 5 .
FIG. 5 is a flowchart showing booklet printing execution processing according to the second embodiment of the present invention. In FIG. 5, the same step numerals as in booklet printing execution processing shown in FIG. 4 in the first embodiment denote the same steps, and a detailed description of the processing will be omitted.
In the second embodiment shown in FIG. 5, processes in steps S 1001 to S 1004 are inserted between steps S 802 and S 803 of the flowchart shown in FIG. 4 . These steps execute print control on cover and back pages in booklet printing processing.
In the second embodiment, the processing shifts from step S 802 to step S 1001 . In step S 1001 , it is determined whether or not printing on the cover page of the cover is designated. If YES in step S 1001 , i.e., “Printing on Cover Page” in FIG. 15 is “checked”, the processing advances to step S 1003 .
If NO in step S 1001 , and “Printing on Cover Page” in FIG. 15 is “not checked”, the processing advances to step S 1002 to insert a blank page at the position of print data to be printed on the cover page of the cover. This is because when print data is comprised of 8 pages, like the first embodiment, blank page data are generated before the first page and after the last page to process the 8-page data as a total of 10-page data. Thereafter, the processing shifts to step S 1003 .
In step S 1003 , it is determined whether or not printing on the back page of the cover is designated. If YES in step S 1003 , i.e., “Insert Other page into Back Page of Cover” in FIG. 15 is checked, the processing shifts to step S 803 and subsequent steps.
If NO in step S 1003 , the processing shifts to step S 1004 to insert a blank page at the position of print data to be printed on the back page of the cover. This is because when print data is comprised of 8 pages, like the first embodiment, blank page data are generated before the first page and after the last page.
If the number of pages exceeds, e.g., the maximum number of saddle stitch enable pages by the device owing to insertion of a blank page, the number of pages is separately adjusted.
Hence, the number of pages subjected to booklet printing processing is processed as a total of 10-page data when printing on the back page of the cover is designated, and as a total of 12-page data when printing on the back page of the cover is not designated. After this processing ends, the processing shifts to step S 803 and subsequent steps.
Processes in step S 803 and subsequent steps are the same as in the first embodiment shown in FIG. 4, and a detailed description thereof will be omitted.
As described above, the second embodiment can control whether or not to print data on the cover and back pages of the cover, in addition to the effects of the first embodiment.
[Other Embodiment]
The present invention may be applied to a system constituted by a plurality of devices (e.g., a host computer, interface device, reader, and printer) or an apparatus comprising a single device (e.g., a copying machine or facsimile apparatus).
The object of the present invention is realized even by supplying a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and causing the computer (or a CPU or MPU) of the system or apparatus to read out and execute the program codes stored in the storage medium.
In this case, the program codes read out from the storage medium realize the functions of the above-described embodiments by themselves, and the storage medium storing the program codes constitutes the present invention.
As a storage medium for supplying the program codes, a floppy disk, hard disk, optical disk, magnetooptical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like can be used.
The functions of the above-described embodiments are realized not only when the readout program codes are executed by the computer but also when the OS (Operating System) running on the computer performs part or all of actual processing on the basis of the instructions of the program codes.
The functions of the above-described embodiments are also realized when the program codes read out from the storage medium are written in the memory of a function expansion board inserted into the computer or a function expansion unit connected to the computer, and the CPU of the function expansion board or function expansion unit performs part or all of actual processing on the basis of the instructions of the program codes.
When the present invention is applied to the above storage medium, the storage medium stores program codes corresponding to the above-described flowcharts.
As has been described above, the present invention can designate a paper feed selection for the cover of a booklet separately from the body, and print out a booklet with a cover desired by the user without any cumbersome user operation. The present invention can automatically determine limitations caused by the hardware of the printing apparatus and limitations caused by designating different paper feed selections for the cover and body of a booklet to print the booklet, and explicitly indicate to the user whether or not booklet printing with a designated cover is possible. Moreover, the present invention can prepare a means for allowing the user to designate whether or not to print data on the cover and back pages of the cover of a booklet, and satisfy various booklet printing needs of the user.
As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.
|
An information processing apparatus connected and capable of transmitting print data to a printing apparatus having a plurality of paper feeds. The information processing apparatus includes (i) means for acquiring information from the printing apparatus, (ii) means for determining whether a cover of a booklet can be printed by the printing apparatus, based on the information obtained by the acquiring means, (iii) means for enabling selection of one of a first paper feed containing cover sheets for printing the cover of the booklet, if the determining means determines that the cover of the booklet can be printed by the printing apparatus, and (iv) generating means for generating print data linked to the paper feeds.
| 1
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is broadly concerned with a novel planking system utilizing an inventive groove design, combinations of planks having an inventive tongue-and-groove configuration, and methods of assembling planks to accommodate the expansion and contraction of the assembled planks.
2. Description of the Prior Art
Wood panels and planks are commonly used for various structures, including decks, porches, walls, and the like. Composite materials offer many benefits over natural wood products for these uses, including improved durability and enhanced moisture resistance. However, wood composites still expand and contract with changes in temperature and moisture like natural wood, which can cause unwanted buckling when these products are used in tongue-and-groove arrangements. In particular, tongue-and-groove arrangements are commonly used in the construction of covered porches, where a small uniform space between each plank is desirable, and where wood composite materials have become increasingly popular. There are two main concerns that arise during the assembly and installation of porch planks when wood or wood composites are used. The first problem is efficiently creating a small space between the planks that is uniform and that can be maintained throughout the installation process. The second problem is accommodating the expansion and contraction of the planks after installation is complete.
Previous attempts to relieve the pressure between planks upon the expansion of the interconnected boards have utilized a “crush bead” located on the tip of the tongue of the plank in anticipation of it being crushed during expansion. Although these crush beads do create the desired space during installation, they do not always crush wider the compressive forces of the adjacent planks, resulting in buckling of the interconnected boards. This especially common in composite tongue-and-groove configurations due to the high compressive strength of the wood composite materials from which the planks and crush beads are formed. It is therefore desirable to have planks or panels with a tongue-and-groove configuration that create the desired space, while at the same time accommodating the expansion and contraction of the interconnected boards.
SUMMARY OF THE INVENTION
The present invention solves these problems by providing planks with a tongue-and-groove configuration providing generally opposed tongue-engaging projections on the side walls of the groove, which create the desired space that is maintained during installation.
In more detail, the present invention provides a plank configured to be assembled with an adjacent plank having a first edge surface and a tongue extending from the first edge surface. The tongue of the adjacent plank is defined by a tongue end wall and a pair of tongue side walls extending between the tongue end wall and first edge. The plank comprises a body presenting a second edge surface and a groove projecting inwardly from the second edge surface along a groove axis, with the groove being configured to receive the tongue of the adjacent plank. The groove is defined by a groove end wall and a pair of groove side walls that extend between the groove end wall and the second edge surface. The groove side walls present generally opposed tongue-engaging projections that are spaced from the groove end wall in alignment substantially perpendicular to the groove axis.
In another embodiment, there is provided a combination of planks comprising a first plank and a second plank utilizing a tongue-and-groove arrangement. The first plank presents a first edge surface, and a tongue extending from the first edge surface. The tongue comprises a tongue end wall and a pair of tongue side walls extending between the tongue end wall and the first edge surface. The second plank presents a second edge surface, and a groove projecting inwardly from the second edge surface along a groove axis and receiving the tongue of the first plank. The groove comprises a groove end wall and a pair of groove side walls extending between the groove end wall and the second edge surface. The groove side walls present generally opposed tongue-engaging projections that are spaced from the groove end wall in alignment substantially perpendicular to the groove axis.
In a further embodiment, a method of assembling porch planks to accommodate expansion and contraction of the assembled planks is provided. The method comprises securing a first plank to a support and positioning a second plank adjacent to the first plank. The first plank presents a first edge surface and a tongue extending from the first edge surface. The tongue comprises a tongue end wall and a pair of tongue side walls extending between the tongue end wall and the first edge surface. The second plank presents a second edge surface and a groove projecting inwardly from the second edge surface along a groove axis to receive the tongue. The groove comprises a groove end wall and a pair of groove side walls extending between the groove end wall and the second edge surface. The groove side walls present generally opposed tongue-engaging projections that are spaced from the groove end wall in alignment substantially perpendicular to the groove axis. The planks are assembled by inserting the tongue into the groove so that the tongue is received in the groove and the tongue end wall is engaged by the tongue-engaging projections, thereby providing an interior space between the tongue end wall and groove end wall, and first and second spaces between the first edge surface of the first plank and the second edge surface of the second plank.
Expansion of the planks after installation pushes the projections off edge-wise, exercising the projections in shear, instead of in compression. In this sense, the tongue-engaging projections are “shearable.” Thus, when a given force is applied to the projections, they break away, relieving the pressure and preventing the buckling of the assembled planks.
Additional advantages of the novel tongue-and-groove configuration and method will be appreciated based upon the drawings and detailed description of the preferred embodiments below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an end view of a preferred plank in accordance with the invention;
FIG. 2 a depicts an enlarged profile view of a preferred groove;
FIG. 2 b depicts an enlarged profile view of a preferred tongue, and illustrates preferred tongue dimensions;
FIG. 3 provides an additional view of a preferred groove to illustrate preferred groove dimensions;
FIG. 4 depicts the profile of two preferred planks connected using the inventive tongue-and-groove combination;
FIG. 5 depicts a top view of the novel planking system and method utilizing the tongue-and-groove combination of the present invention; and
FIG. 6 depicts the expansion of the planks after installation, and the shearing off of the tongue-engaging projections that occurs upon expansion.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following sets forth preferred embodiments in accordance with the present invention. It is to be understood, however, that these preferred embodiments are provided by way of illustration and nothing therein should be taken as a limitation upon the overall scope of the invention that is claimed.
Referring to FIG. 1 , an end view of a preferred plank 10 in accordance with the present invention is provided. The plank 10 comprises a body 12 , presenting a first edge surface 14 , a second edge surface 15 , and an underside 36 . The first edge surface 14 includes a tongue 22 extending from the first edge surface 14 . The tongue 22 comprises a tongue end wall 30 and a pair of tongue side walls 32 , 34 extending between the tongue end wall 30 and the first edge surface 14 . The second edge surface 15 comprises an upper edge surface 15 a and a lower edge surface 15 b , and includes a groove 16 projecting inwardly from the second edge surface 15 along a groove axis 18 . The groove 16 is defined by a groove end wall 24 and a pair of groove side walls 26 , 28 , extending between the groove end wall 24 and the second edge surface 15 . It will be appreciated that although the underside 36 of the plank 10 illustrated in FIG. 1 is contoured, planks, boards, or panels can be provided with an underside 36 having a different contour, or being flat, without going beyond the scope of the present invention. It will also be appreciated that the present invention is not limited only to planks having a tongue extending from the first edge surface 14 and a groove projecting inwardly from the second edge surface 15 . Rather, planks can be adapted in a number of ways, depending upon the final desired use, in accordance with the present invention. For example, a plank can be configured to have two grooves or two tongues, one on each of the first and second edge surfaces 14 , 15 , respectively. It is also envisioned that a plank in accordance with the present invention can have a groove or a tongue on one edge surface only with the other edge surface having neither a tongue nor a groove, depending upon the final desired assembly.
FIGS. 2 a - 2 b illustrate an enlarged view of a preferred groove 16 and a preferred tongue 22 in accordance with the present invention. In more detail, as shown in FIG. 2 a , the groove side walls 26 , 28 present generally opposed tongue-engaging projections 38 , 40 , respectively, in alignment substantially perpendicular to the groove axis 18 , and spaced from the groove end wall 24 , to define respective spaces 42 , 43 between the projections 38 , 40 and the groove end wall 24 . The respective spaces 42 , 43 are preferably from about 0.50 mm to about 1.8 mm, more preferably from about 0.6 mm to about 1.6 mm, and even more preferably from about 0.8 mm to about 1.0 mm, when measured from the groove end wall 24 to the center of each tongue-engaging projection 38 , 40 . As shown in FIG. 2 b , the preferred tongue 22 has a length “L” being defined between the tongue end wall 30 and a plane 44 coinciding with that created by the first edge surface 14 ; a width “W” being defined as the greatest distance between the tongue side walls 32 , 34 ; and a width “W′” being defined as the shortest distance between the tongue side walls 32 , 34 . In a particularly preferred embodiment, the tongue side walls 32 , 34 are inwardly sloped to narrow the distance between the side walls 32 , 34 , and terminating at the tongue end wall 30 , causing the tongue 22 to be tapered when viewed from the side. In this embodiment, the length of W′ is less than the length of W. More particularly, W′ is at least about 60% the length of W, preferably from about 60% to about 100% the length of W, more preferably from about 70% to about 90% the length of W, and even more preferably at least about 82% the length of W. As shown in FIG. 2 a , the groove side walls 26 , 28 are also preferably inwardly sloped to narrow the distance between the groove side walls 26 , 28 , and terminating at the groove end wall 24 , creating a tapered groove 16 corresponding to the tapered tongue 22 .
The dimensions of a preferred groove are shown in more detail in FIG. 3 . The tongue-engaging projections 38 , 40 , respectively, extend from the groove side walls 26 , 28 , but are preferably spaced apart from each other, where “d” is the distance between the projections 38 , 40 . More preferably, the tongue-engaging projections are spaced apart from each other a distance d that is less than the width W′ of the tongue 22 (shown in FIG. 2 b ).
The tongue-engaging projections 38 , 40 also preferably have a height “h.” The height h is measured from the highest point of the projections 38 , 40 to their respective groove side walls 26 , 28 on the respective sides of tongue-engaging projections 38 , 40 that are adjacent the groove end wall 24 . The tongue-engaging projections 38 , 40 also preferably have a width “w,” as measured from the widest portion of the tongue-engaging projections 38 , 40 . In a particularly preferred embodiment, the tongue-engaging projections 38 , 40 have a height h of at least about 0.50 mm, preferably from about 0.70 mm to about 0.90 mm, and more preferably about 0.812 mm, and a width w of at least about 0.01 mm, preferably from about 0.02 mm to about 0.05 mm, and more preferably about 0.030 mm. It is also preferred that the height h be greater than the width w, more preferably at least about 2% greater, and even more preferably from about 2% to about 6% greater.
As shown in FIG. 4 , the groove 16 is configured to receive the tongue 22 of an adjacent plank 11 . When assembled, the adjacent planks 10 , 11 preferably have first and second spaces 46 , 48 , between the first edge surface 14 and the second edge surface 15 of each plank, and an interior space 52 between the groove end wall 24 and the tongue end wall 30 . More particularly, the assembled planks have a first space 46 above the tongue-and-groove configuration and a second space 48 below the tongue-and-groove configuration. The first and second spaces 46 , 48 , respectively, should be from about 0.10 mm to about 1.5 mm, preferably from about 0.80 mm to about 1.2 mm, and more preferably from about 1.0 mm to about 1.2 mm. In a further preferred embodiment, the first and second spaces 46 , 48 are different sizes, as shown in FIG. 4 , with the lower edge surface 15 b preferably being undercut and the first space 46 being smaller than the second space 48 . In this embodiment, the second space 48 should be from about 1.0 mm to about 2.54 mm, preferably from about 1.6 mm to about 1.9 mm, more preferably from about 1.78 mm to about 1.9 mm. The interior space 52 between the groove end wall 24 and the tongue end wall 30 should be from about 1.2 mm to about 3.0 mm, preferably from about 1.75 mm to about 2.5 mm, more preferably from about 1.9 mm to about 2.25 mm.
The first and seconds spaces 46 , 48 , and the interior space 52 are determined by the placement of the tongue-engaging projections 38 , 40 along the groove side walls 26 , 28 in relation to the second edge surface 15 . Referring again to FIG. 3 , the tongue-engaging projections 38 , 40 are preferably spaced from the second edge surface 15 a distance “D,” as measured from the center of the tongue-engaging projections to a plane 50 extending along the second edge surface 15 of the plank 10 . More preferably, the distance D is less than the length L of the tongue 22 of the adjacent plank 11 . In particular, the distance D is preferably from about 40% to about 95% the length L, more preferably from about 60% to about 90% the length L, even more preferably from about 80% to about 85% the length L. In this embodiment, when the tongue 22 is received in the groove 16 , the tongue-engaging projections 38 , 40 engage the tongue 22 , and more preferably the tongue end wall 30 , to provide the desired spaces 46 , 48 , 52 , respectively. Accordingly, the tongue-engaging projections 38 , 40 should be strong enough to prevent the tongue 22 of the adjacent plank 11 from being forced past the tongue-engaging projections 38 , 40 and into the groove end wall 24 during installation of the plank system. It is also preferred that the tongue-engaging projections 38 , 40 are integrally formed with the material forming the plank 10 . In other words, the entire plank 10 unitarily formed.
The planks can be made from any suitable material including sized lumber, synthetic materials, and wood composites. When formed from natural woods, the novel tongue-and-groove configuration can be formed for example, by conventional routering methods. A preferred method for forming wood composites with the novel tongue-and-groove configuration is by extrusion so that the tongue-and-groove configuration, including the tongue-engaging projections, are integrally formed with the material forming the planks.
In particular, a preferred method for making wood composites can be found in U.S. Pat. No. 6,737,006, incorporated by reference herein. In more detail, the products are formed by introducing ingredients including respective quantities of a fibrous or cellulosic material and polypropylene into the inlet of an extruder (preferably a twin screw extruder). Preferably, the weigh blender is positioned immediately above the extruder, at the extruder inlet, so that the blend of ingredients is formed immediately prior to entering the extruder, thus minimizing or preventing separation of the ingredients.
The screw(s) is then rotated at a rate of from about 10-50 rpm, and preferably from about 15-34 rpm to advance the ingredients through the extruder barrel and out the extrusion die to form the composite product. The die is configured to present an orifice configured to correspond to the desired plank or board profile, including the tongue-engaging projections 38 , 40 . Preferably, the screw(s) has a compression ratio of from about 2:1 to about 4:1, and more preferably from about 2.8:1 to about 3.6:1.
The temperature of the ingredients in the extruder barrel is preferably from about 150-260° C., and more preferably from about 175-230° C. The retention time of the ingredients in the barrel should be from about 20-120 seconds, and more preferably from about 40-80 seconds. Finally, the ingredients should be advanced through the barrel at a rate of from about 500-2,000 lbs/hr., and more preferably from about 1,000-1,500 lbs/hr.
The fibrous material is preferably present in the ingredients at a level of from about 20-80% by weight, more preferably from about 30-70% by weight, and even more preferably from about 50-70% by weight, based upon the total weight of the ingredients taken as 100% by weight. The polypropylene is preferably present in the ingredients at a level of from about 20-80% by weight, more preferably from about 30-70% by weight, and even more preferably from about 30-50% by weight, based upon the total weight of the ingredients taken as 100% by weight.
Preferred fibrous materials include those selected from the group consisting of sawdust, newspaper, alfalfa, wheat pulp, wood scraps (e.g., ground wood, wood flour, wood flakes, wood chips, wood fibers, wood particles), wood veneers, wood laminates, cardboard, straw, cotton, rice hulls, paper, coconut shells, peanut shells, bagasse, plant fibers, bamboo fiber, palm fiber, kenaf, and mixtures thereof. Furthermore, the average particle size of the fibrous material should be less than about ½ inch, and more preferably from about 1/16-¼ inch. Finally, the particles of the fibrous material should have an average aspect ratio (i.e., the ratio of the length to the widest thickness) of at least about 10:1, preferably at least about 20:1, and more preferably from about 30:1 to about 50:1. The use of such long particles increases the flexural modulus of the product as compared to products with lower aspect ratios by at least about 25%, and preferably at least about 40%, thus causing the final composite product to have a stiffness comparable to natural wood.
The preferred polypropylene for use in the invention is reactor flake polypropylene (i.e., the polymer flakes as they are produced in the reactor), preferably without any further treatment (e.g., without the addition of chemical additives or modifiers) to the polypropylene. The preferred polypropylene has a melt index at 230° C. of from about 0-10 g/10 min., preferably from about 0.1-4 g/10 min., and more preferably from about 0.1-1 g/10 min. Furthermore, it is preferred that the polypropylene has a bulk density of from about 20-40 lbs/ft 3 , and more preferably from about 28-32 lbs/ft 3 . The average fiber length or particle size of the polypropylene flakes utilized should be from about 350-1,000 μm, and preferably from about 500-700 μm.
The resulting composite product is in the form of a self-sustaining body and has an ASTM D-6109 flexural modulus of from about 600-1,100 psi, and preferably from about 800-1,100 psi. The product should have an actual density of from about 40-60 lbs/ft 3 , and preferably from about 50-58 lbs/ft 3 .
A number of optional ingredients can also be added to modify or adjust the properties of the final composite product. Examples of such ingredients include acrylic process aids (e.g., Rohm and Haas K175, Kaneka Kane-AcePA-101), UV stabilizers (e.g., CYTEC 38535, CYTEC 3346), and coloring agents. If a process aid is utilized, it is preferably present in the ingredients at a level of from about 0.5-5% by weight, and more preferably from about 1-2% by weight, based upon the total weight of the ingredients taken as 100% by weight. Unexpectedly, these acrylic process aids are particularly useful in the present invention in spite of the fact that they are intended to be used in PVC products rather than polypropylene products.
In use, the planks can be assembled and secured using traditional methods, including by securing through the face of the board, or through the tongue and/or groove, depending upon the final desired use. With reference to the plank system illustrated in FIG. 5 , a preferred method of assembly comprises the steps of securing a first starter plank 56 to a support (not shown). Preferably, the starter plank is secured through the face of the board using any suitable fastening device 58 (e.g., deck screws, nails, etc.). Next, a second plank 60 is positioned adjacent the starter plank 56 and the tongue 22 of the starter plank 56 is inserted into the groove 16 of the second plank 60 until the tongue end wall 30 is engaged by the tongue-engaging projections 38 , 40 in the groove 16 . The second plank is then secured, preferably, through the tongue of the second plank (see FIG. 6 ). More preferably, the second plank is secured by countersinking a nail, screw, or other fastening device 58 into the tongue 22 , so that it does not obstruct the tongue from being subsequently received into the groove of the next adjacent plank 62 . This preferred method automatically provides the desired first and second spaces 46 , 48 , respectively, between each plank, with the first space 46 between the planks being above the tongue-and-groove configuration and the second space 48 between the planks being below the tongue-and-groove configuration.
With reference to FIG. 6 , the tongue-engaging projections 38 , 40 should be configured to shear or break away when a given force is generated by expansion of planks 10 and/or 11 after installation. As shown in FIG. 6 , the assembled planks 10 , 11 utilizing the novel tongue-and-groove configuration have swelled and expanded. In particular, the second edge surface 15 of the plank 10 has expanded into the first edge surface 14 of the adjacent plank 11 , and the tongue-engaging projections 38 , 40 have been sheared or broken away by the tongue 22 of the adjacent plank 11 to permit this expansion. In this manner, the novel plank system and method allow for the planks to expand during temperature and/or moisture level changes, thereby preventing buckling of the assembled planks, in particular, when the planks are formed of high compressive strength composite materials.
It will be appreciated by those skilled in the art that although the foregoing description has been given with reference to planks having a length and respective end portions, the novel tongue-and-groove configuration and spacing system can be adapted to a wide number of areas, in addition to porch planking. In particular, the novel tongue-and-groove arrangement can be adapted to accommodate any application where wood and/or wood composites are commonly used, such as in wood and simulated wood flooring, decking, wall paneling, and roof paneling, door sills and jambs, fascia board, window edging, window sills, decorative architectural trim (e.g., deck or patio railing), and landscaping products (e.g., raised bed edging, flowerbed edging, driveway edging). It will also be appreciated that the inventive tongue-and-groove configuration can extend along the length of the planks, panels, or boards. However, the tongue-and-groove configuration can also be segmented along the length of the planks, panels, or boards, without going beyond the scope of this invention.
|
A novel planking system utilizing an inventive groove design is provided. The novel groove is defined by two opposing side walls and a groove end wall. The groove side walls present two generally opposed tongue-engaging projections that automatically provide a uniform space between planks during installation, and accommodate expansion of the planks after installation by breaking away when force is exerted on the projections by an adjacent plank. The present invention is also concerned with a combination of planks having an inventive tongue-and-groove configuration, as well as inventive methods of assembling planks to accommodate the expansion and contraction of the assembled planks after installation.
| 4
|
FIELD
[0001] The present disclosure relates to a vibration attenuation system for a vehicle steering wheel, and more particularly to a mass-damper system having an elastomeric element.
BACKGROUND
[0002] This section provides background information related to the present disclosure which is not necessarily prior art.
[0003] Comfort and feel are important qualities in modern automotive vehicles. Noise, vibration and harshness (NVH) in a steering wheel of the vehicle can adversely affect the overall comfort and feel of the vehicle. Vibrations from the engine, suspension and/or other components of the vehicle may propagate through the steering system to the steering wheel and the driver's hands. Such vibrations can be uncomfortable and/or produce undesirable noise.
SUMMARY
[0004] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
[0005] In one form, the present disclosure provides a vibration attenuation apparatus that may include a mass element, a bracket, and an elastomeric member. The mass element may include a first aperture. The bracket may include first and second portions. The first portion may be adapted to be attached to a structure that transmits an input vibration. The elastomeric member may engage the mass element and the second portion of the bracket and may suspend the mass element in spaced relation relative to the bracket. The elastomeric member may include a shaft portion and a barb portion. The shaft portion may engage the second portion of the bracket. The barb portion may engage the first aperture of the mass element. The elastomeric member may include properties allowing the mass element to move relative to the bracket in response to the input vibration at a frequency that reduces an amplitude of the input vibration.
[0006] In another form, the present disclosure provides a mass-damper assembly for a steering wheel. The mass-damper assembly may include a mass element, a bracket, and first and second elastomeric fasteners. The mass element may include a first engagement aperture and a second engagement aperture. The bracket may include a mounting arm for mounting the assembly to the steering wheel, a first support arm supporting the mass element, and a second support arm supporting the mass element. The first and second support arms may include first and second support apertures, respectively. The first elastomeric fastener may engage the first support aperture and the first engagement aperture. The second elastomeric fastener may engage the second support aperture and the second engagement aperture. The first and second elastomeric fasteners may maintain the mass element in a spaced apart relationship relative to the first and second support arms and allow the mass element to vibrate relative to the first and second support arms at a frequency that reduces an input vibration from the steering wheel.
[0007] In yet another form, the present disclosure provides a method that may include determining vibration characteristics of a steering wheel hub, tuning a plurality of elastomeric members to include predetermined structural properties based on the determined vibration characteristics of the steering wheel hub, securing a bracket to the steering wheel hub, suspending a mass from the bracket via the plurality of elastomeric members, and allowing the mass to vibrate relative to said bracket at a frequency that reduces vibration in the steering wheel hub.
[0008] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0009] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
[0010] FIG. 1 is a perspective view of a steering wheel including a mass-damper assembly according to the principles of the present disclosure;
[0011] FIG. 2 is a perspective view of the mass-damper assembly of FIG. 1 ;
[0012] FIG. 3 is an exploded perspective view of the mass-damper assembly of FIG. 1 ;
[0013] FIG. 4 is a perspective view of an elastomeric member of the mass-damper assembly according to the principles of the present disclosure;
[0014] FIG. 5 is a front view of the mass-damper assembly; and
[0015] FIG. 6 is a top view of the mass-damper assembly.
DETAILED DESCRIPTION
[0016] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses. It should be understood that throughout the several views of the drawings, corresponding reference numerals indicate like or corresponding parts and features.
[0017] Throughout the description, example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
[0018] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
[0019] When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0020] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
[0021] Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
[0022] With reference to FIGS. 1-6 , a mass-damper assembly 10 is provided and may include a bracket 12 , a mass element 14 , and a plurality of elastomeric fasteners 16 . The mass-damper assembly 10 may be mounted to a central hub area 18 of a steering wheel assembly 20 . As will be subsequently described, the plurality of elastomeric fasteners 16 may cooperate to suspend the mass element 14 relative to the bracket 12 and allow the mass element 14 to vibrate at a frequency and amplitude that reduces an input vibration that can be transmitted through the steering wheel assembly 20 .
[0023] The bracket 12 may be formed from a relatively thin plate or sheet of metal, plastic or other material and may include a body portion 22 having first and second mounting arms 24 , 26 and first and second support arms 28 , 30 extending therefrom. Each of the first and second mounting arms 24 , 26 may include a mounting aperture 32 extending therethrough. Fasteners 34 may engage the mounting apertures 32 and corresponding threaded apertures in the hub 18 to secure the bracket 12 to the steering wheel assembly 20 .
[0024] The first and second support arms 28 , 30 may extend from the body portion 22 in a first dimension X that is substantially perpendicular to body portion 22 and the first and second mounting arms 24 , 26 . Each of the first and second support arms 28 , 30 may include a first portion 40 and a second portion 42 . The first portion 40 may include a slot 44 extending at least partially across a length of the first portion 40 . The second portion 42 may extend outwardly from the first portion 40 to form a generally L-shaped cross section. Each of the second portions 42 may include an outwardly facing surface 49 , an inwardly facing surface 50 , and one or more support apertures 51 extending therethrough.
[0025] The mass element 14 may be a generally solid block formed from a metallic or polymeric material, for example, or any other suitable material. The particular material, size and/or shape of the mass element 14 may be selected to yield a predetermined weight, as will be subsequently described. The mass element 14 may include a first end 52 , a second end 54 , and a first side 56 . Each of the first and second ends 52 , 54 may include one or more engagement apertures 58 extending inwardly therefrom in a second dimension Z. The engagement apertures 58 may be positioned relative to each other such that each of the plurality of engagement apertures 58 is aligned with a corresponding one of the support apertures 51 in the bracket 12 . While the engagement apertures 58 are described above as being disposed in the first and second ends 52 , 54 , in other embodiments, the engagement apertures 58 may be disposed in any other suitable portion of the mass element 14 .
[0026] The first side 56 may include a plurality of apertures 60 extending through at least a portion of a thickness of the mass element 14 in a third dimension Y. Each of the plurality of apertures 60 can correspond to and be in communication with one of the engagement apertures 58 . While the plurality of apertures 60 are shown in the figures having a generally square shape, it will be appreciated that the plurality of apertures 60 could be round or otherwise suitably shaped.
[0027] The elastomeric fasteners 16 may be formed from a resiliently compressible and elastic material such as a natural rubber, silicone, or other elastomeric materials. Each of the elastomeric fasteners 16 may include a shaft portion 70 , a head portion 72 , and a barbed tip portion 74 . The head portion 72 may be disposed at a first end of the shaft portion 70 and the tip portion 74 may be disposed at a second end of the shaft portion 70 . The shaft portion 70 and the head portion 72 may be generally cylindrical members. As shown best in FIG. 4 , the tip portion 74 may include a frusto-conical configuration with a first end 78 and a second end 80 . The first end 78 may include a larger perimeter than a diameter of the shaft portion 70 and the second end 80 may include a smaller perimeter than the perimeter of the first end 78 . Tip portion 74 may include a plurality of flat faces 76 that are angled relative to the shaft portion 70 and extend from the first end 78 to the second end 80 , as shown in FIG. 4 . It should be appreciated that tip portion 74 may not include flat faces 76 , or may include fewer or more flat faces 76 than illustrated including, for example, two opposed flat faces 76 . While the mass-damper assembly 10 is shown in the figures having two pairs of opposing elastomeric fasteners 16 , in other embodiments, the mass-damper assembly 10 could have any number of elastomeric fasteners 16 arranged in any suitable configuration.
[0028] Each of the elastomeric fasteners 16 may be inserted through a corresponding one of the support apertures 51 and into a corresponding one of engagement apertures 58 such that the tip portion 74 is received in and engages a corresponding one of the apertures 60 and the head portion 72 abuts the outwardly facing surface 49 of the second portion 42 of the bracket 12 . The first end 78 of the barbed tip portion 74 may include a width or diameter of the perimeter that is greater than a diameter of the engagement aperture 58 such that the tip portion 74 is retained in aperture 60 after being inserted through engagement aperture 58 . In addition, the flat faces 76 may facilitate easier insertion of end 78 of tip portion 74 through the smaller diameter of engagement aperture 58 .
[0029] The elastomeric fasteners 16 engaging the apertures 60 proximate the first and second ends 52 , 54 of the mass element 14 , respectively, may exert equal and opposite retaining forces on the mass element 14 , thereby retaining the mass element 14 in a suspended condition relative to the bracket 12 such that the mass element 14 is spaced apart from the inwardly facing surfaces 50 of the second portions 42 and the rest of the bracket 12 . The resiliently deflectable material and structure of the elastomeric fasteners 16 may allow the mass element 14 to vibrate or move relative to the bracket 12 in the first, second and/or third dimensions X, Z, Y and without contacting bracket 12 .
[0030] With reference to FIGS. 1-6 , operation of the mass-damper assembly 10 and a method of attenuating vibration will be described in detail. As described above, the mass-damper assembly 10 may be mounted to the hub area 18 of the steering wheel assembly 20 and may reduce or attenuate vibrations in the steering wheel assembly 20 . The material and structure of the elastomeric fasteners 16 may be designed or tuned to allow the mass element 14 to vibrate at a predetermined frequency and amplitude in response to vibrations that may propagate through the steering wheel assembly 20 and into the bracket 12 . Such vibration of the mass element 14 relative to the bracket 12 may cancel or reduce these vibrations in the steering wheel assembly 20 .
[0031] The mass-damper assembly 10 for a particular steering wheel assembly 20 of a particular vehicle may be tuned based on calculated or measured vibration characteristics of the particular steering wheel assembly 20 such as a natural frequency and a frequency and amplitude of vibration at the hub area 18 during operation of the vehicle. Vibration in the hub area 18 having a first frequency can be cancelled or reduced by introducing vibration of the mass element 14 at a second frequency that is phase shifted relative to the first frequency. Therefore, based on the vibration characteristics of the steering wheel assembly 20 , desired vibration characteristics of the mass element 14 relative to the bracket 12 can be determined that will cancel or reduce an amplitude of vibration in the steering wheel assembly 20 .
[0032] To achieve the desired vibration characteristics of the mass element 14 , the weight of the mass element 14 and/or material and/or geometric properties of the elastomeric fasteners 16 may be adjusted or tuned such that the mass element 14 will vibrate at the second frequency in response to vibration of the hub 18 of the steering wheel assembly 20 at the first frequency. Such tuning may include selecting a material having a desired modulus of elasticity, modulus of rigidity, and/or Young's modulus, for example, and/or adjusting relative dimensions and/or geometry of the elastomeric fasteners 16 , for example, to facilitate vibration of a particular mass element 14 having a given weight.
[0033] Once the elastomeric fasteners 16 have been tuned for a given application, the mass-damper assembly 10 may be assembled and installed onto the hub area 18 of the steering wheel assembly 20 . During operation of the vehicle, vibrations from operation of various vehicle systems (e.g., the engine, suspension and/or steering system) and/or encounters with bumps in the road or driving surface may propagate to the hub area 18 and the bracket 12 . Such input vibrations (vibrating at a first frequency) may propagate through the first and second mounting arms 24 , 26 , the body portion 22 , and the first and second support arms 28 , 30 . Because the mass element 14 is suspended relative to the bracket 12 via the elastomeric fasteners 16 , the mass element 14 is allowed to vibrate at a second frequency in response to the input vibrations. As described above, the second frequency may be phase shifted relative to the first frequency, thereby cancelling or reducing the amplitude of the vibration in the steering wheel assembly 20 .
[0034] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.
|
A vibration attenuation apparatus may include a mass element, a bracket, and an elastomeric member. The mass element may include a first aperture. The bracket may include first and second portions. The first portion may be attached to a structure that transmits an input vibration. The elastomeric member may engage the mass element and the second portion of the bracket and may suspend the mass element relative to the bracket. The elastomeric member may include a shaft portion and a barb portion. The shaft portion may engage the second portion of the bracket. The barb portion may engage the first aperture of the mass element. The elastomeric member may include properties allowing the mass element to move relative to the bracket in response to the input vibration at a frequency that reduces an amplitude of the input vibration.
| 5
|
BACKGROUND OF THE INVENTION
The present invention relates to a rope element, and, more particularly, to a relatively short rodeo rope commonly referred to as a pigging string. Rodeo events commonly require the use of such ropes to tie the feet of calves which have been roped from horseback. The rodeo rider carries the pigging string to the roped calf, forces it off of its feet and utilizes the pigging string to bind the animal's legs. Time is generally of the essence. In fact, the whole event is usually judged according to the amount of time required to render the animal nonambulatory. For this reason, all associated apparatus such as lariats and pigging strings involved in the event must facilitate the rodeo rider's speed and effectiveness.
Prior art constructions of ropes for use as pigging strings have not been uniform and have varied considerably in both materials and technique of fabrication. On the average, such strings are on the order of six feet long and include an eye, or loop, at one end. However, the various rope characteristics such as stiffness, hardness, twist density, pliability, weight and durability have not been consistent, therein presenting problems. As in any athletic event, the "tools" of the event are integral to the success of the participant. Variations in the aforesaid characteristics of pigging strings thus affect the performance of the rodeo rider. It is particularly important for the pigging string to be hard and tightly woven to prevent stretching, while sufficiently pliable and balanced to facilitate the tying action therewith.
The main problematic manifestation in pigging strings centers in the loop at the one end. The loop must provide the requisite tensile strength without being loose or bulky. For reasons of balance and control, it is preferable for the loop to smoothly blend into the remaining string section. Such a configuration is difficult to achieve. Standard textile rope splicing techniques and the improvements thereto have not provided a suitable back splice configuration for pigging strings. For example, U.S. Pat. No. 3,411,400 issued to Morieras et al. on Nov. 19, 1968, discloses an improved back spliced loop for textile ropes. Such techniques as described therein illustrate the utility of effective back splice configurations. However, pigging strings do not normally lend themselves to such sophisticated multistranded braiding for reasons of size, weight, balance, and related characteristics.
Most prior art pigging strings are comprised of either grass or nylon ropes having a loop formed therein by a "knot"-like interlace. Generally, the pigging string of this type is formed by cutting a longer rope and utilizing a splicing device to weave the untwisted end thereof back into an intermediate region therealong. Such a device and technique is illustrated in U.S. Pat. No. 2,112,176 issued to Olsson on Mar. 22, 1938. Although effective in creating a loop, or eye, splicing devices generally do not permit the formation of the smooth interface and tautness needed in pigging strings due to their short length. Moreover, the optimal pigging string loop has no "twist bias" and is considerably shorter than conventional back splicing embodiments wherein the end of the rope is woven into the intermediate section of rope a plurality of times.
It would be an advantage therefore to provide a pigging string having a uniform hardness, tautness and pliability therealong and around a loop formed on the end thereof, which loop is substantially devoid of twist bias, ridges or loose strand ends. The pigging string and method of fabrication therefor of the present invention is especially adapted for just such an embodiment. The loop is formed during fabrication of the string, while it is being twisted and may be constructed with zero twist bias. In this manner, the tautness of the pigging string can be uniformly maintained even in the loop, which can be secured without multiple weaving therealong. The pigging string of such an assembly also facilitates improved fabrication techniques due to the inherent back splice solidarity.
SUMMARY OF THE INVENTION
The invention relates to pigging strings for rodeo riders wherein the pigging string is manufactured with a taut, integrally formed backsplice. More particularly, one aspect of the invention includes an improved pigging string of the type including a plurality of core filaments twisted into an elongated rope section of fixed length with a loop secured at one end thereof. The improvement comprises a first length of core filaments tautly twisted into an intermediate loop section therein being reversed upon itself. The loop section is intermediate of second and third core filament sections intertwined one with the other. The second core filament section is substantially shorter than the third core filament section and integrally interlaced therein in an untwisted state prior to the twisting of the third core filament section thereagainst. The third core filament section being in a tautly twisted configuration adjacent the loop section, thereby secures the untwisted interlaced core filaments of the second core filament section securely thereagainst.
In another aspect, the invention includes a pigging string wherein three core filaments are twistably united and the second core filament section is integrally interlaced into the third core filament section through a single phase juncture. The single phase juncture includes the uppermost core filament of the second core filament section wrapped once around the uppermost core filament of the third core filament section. The single phase juncture also includes the two lower core filaments of the second core filament section respectively wrapped, once around and singularly through the two lower core filaments of the third core filament section. The ends of the three core filaments of the second core filament section are then cut to lie substantially adjacent the periphery of the third core filament section, alleviating twist ridges and loose strand lays.
In yet another aspect, the invention includes a method of fabricating a pigging string having a loop integrally formed on one end thereof and including three strands of filaments twistably united through the steps of extending the strands in a lengthwise configuration between two points and then twisting a first segregated section of strands adjacent one of the points. A first end of the first section of twisted strands is secured adjacent the nontwisted strands. Next, a length of the strands on the opposite, second end of the first section of strands is untwisted. A second end of the first section of twisted strands adjacent the untwisted strands is then secured and the first section of strands is reversed upon itself, whereby the second end of the first section of twisted strands is disposed adjacent the first end. The untwisted strands are interlooped through adjacent nontwisted strands with the ends of the untwisted strands extending outwardly therefrom. The nontwisted strands are then twisted adjacent the loop for securing the untwisted strands thereagainst and providing the pigging string in a fixed length.
The final fabrication step in the assembly of the pigging string of the present invention also includes dipping the fixed length string in a hot wax bath. The string is then permitted to cool in a stressed condition. In this manner the pigging string and particularly the loop thereof provides the requisite rigidity and tensile strength in a tightly wound, pliable embodiment. The absence of loose strands and ridges around the loop further facilitates a balanced use thereof and the requisite reliability necessary in rodeo competition.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and, for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a fragmentary, perspective view of a pigging string fabricated in accordance with the principles of the present invention;
FIG. 2 is a fragmentary, perspective view of one step in the fabrication of the pigging string of FIG. 1;
FIG. 3 is a fragmentary, perspective view of a subsequent assembly step in the fabrication of the pigging string of FIG. 2, illustrating the interlooping of untwisted strands into nontwisted strands to provide an integrally formed eye member;
FIG. 4 is a fragmentary, perspective view of the interlooped strands of FIG. 3 in a tautly isolated configuration; and
FIG. 5 is a perspective view of the pigging string of FIG. 4 and eye member formed therein after the subsequent assembly step of twisting the nontwisted strands thereagainst.
DETAILED DESCRIPTION
Referring first to FIG. 1, there is shown a relatively short, multistranded rope member 10 of the type commonly referred to as a pigging string. In rodeo competition, such rope members are used to bind calves' feet after the animals have been roped from horseback. The pigging string 10 of the present invention is constructed of relatively short length and with a single loop, or eye 12, at one end 14 thereof. The opposite end 16 is usually threaded through the eye 12 during rodeo use to form an adjustable loop which is tightened around the roped animals' feet.
The eye 12 of the invention is integrally formed in the body 18 of the pigging string 10. As used herein, the term "integrally formed" shall mean constructed therein during fabrication thereof as contrasted to conventional back splice methods wherein the eyes are formed by weaving loose strands into an already twisted rope member.
The integrally formed eye 12 is constructed in such a way as to eliminate ridges and loose strands commonly found in prior art pigging strings. In this manner, also, the ends of the interlaced strands are secured between the twists thereof so as to not protrude therefrom. A rope guard 20, or jacket, is illustrated upon the end section of the eye 12, as such is conventionally provided for durability.
Referring now to FIG. 2, there is shown one step in the fabrication of the pigging string 10 in accordance with the principles of the present invention. In the particular embodiment shown herein, three core filaments, or strands 22, are utilized. These strands 22 may be of conventional rope material such as hemp or nylon. The strands 22 are first extended between two support points (not shown) for assembly purposes. The "points" are generally fasteners, or the like, of the type utilized in rope manufacture; which support the ends of various strand elements prior to the twisting thereof. Usually a first of said points, or fasteners is rotatably mounted for twisting the strands 22 extending therefrom and relative to the second opposite point. Such apparatus for supporting and twisting core filaments is conventional, does not comprise a part of the present invention, and is therefore not illustrated herein.
Still referring to FIG. 2, the first step in assembling the pigging string 12 is the twisting and isolation of a first short section 24 of the nontwisted strands 22, to form the body of the eye 12. The twisted section 22 is intermediate of second and third strand sections 26 and 28, respectively, and may be constructed without twisting either of said outer strand sections. In this manner, both outer strand sections 26 and 28 may remain nontwisted, as that term is used herein. However, the most expedient and preferable manner of construction is the twisting of the strands 22 from the first point of support thereof, back through sections 26 and 24, leaving section 28 nontwisted. A first end of section 24, adjacent section 28 is then secured with tape 30, or the like, to prevent untwisting. Next, the opposite, second, end of section 24 is also secured with tape 32, or the like, to prevent untwisting. The first point of support is then detached from the strands 22 and the strands forming section 26 thereof are untwisted, as shown in FIG. 2. Preferably, the strands 22 of section 26 are relatively short, on the order of six inches, since little more is needed to interloop the nontwisted strands of section 28.
Referring now to FIG. 3, there is shown the assembly of the twisted section 24 into the eye 12. The strands 22 of section 26 are brought to a position adjacent the strands 22 of section 28 and interlaced therein in a manner herein referred to as "interlooping". The individual strands 22 of untwisted section 26 are comprised of strands 34, 36 and 38 as shown. The individual strands 22 of the nontwisted section 28 are comprised of strands 44, 46 and 48. The strand numbering will facilitate explanation of the specific nature of interlooping as that term is used herein.
Still referring to FIG. 3, it may be seen that strand 36 is once wrapped around strand 46, strand 38 once wrapped around strand 48 and strand 34 once wrapped around strand 44. The particular strand interengagement herein defined is preferable to eliminate ridges and loose lays and provide a substantially rigid eye 12. Moreover, in this manner the eye 12 is formed without twist bias, which is the condition of the loop body 24 to exhibiting out of plane curvature or twist deformation. For example when the section 24 is reversed upon itself, it is done so uniaxially, or without any degree of twist. The strands 22 are thus arranged with mating lay configurations which facilitate interlooping. It may further be seen that each group of strands 22 is comprised of a top, or center strand, adjacent the two lower strands. This configuration is obtained when the tape 30 and 32 is applied at the ends of the twisted section 24. In the embodiment shown herein the center strands are 38 and 48 in string sections 26 and 28 respectively. When the twisted section 24 is uniaxially reversed upon itself, the center strand 38 lies atop center strand 48.
The strands 22 are interlaced in what is referred to as a single phase juncture. This term is utilized to describe the wrapping of each strand of section 26 in a single phase, or on the order of 180°, around the nontwisted strands of section 28. Additionally, the strands 22 of section 26 are wrapped singularly about the strands 22 of section 28. Specifically, strand 36 extends outwardly of strand 46 before it continues under, inward and between strand 46 and 48. In like manner, strand 34 extends inwardly of strand 44 before it continues under, and outwardly of strand 44 to maximize the strength of the single phase juncture. It is important to note that for strength, interlacing of strands in conventional ropes is generally multi-phase in nature, and in effect is similar to weaving the strands together. This technique is not generally suitable for pigging string fabrication due to weight, size and balance considerations.
Referring now to FIG. 4, there is shown the interlooped strand assembly of FIG. 3 in a more taut configuration prior to final assembly. It may be seen that the strands 34, 36 and 38 are pulled foward of section 28 whereby the tension and rigidity in the interlaced configuration is maximized. In this manner the strands 22 of section 26 may be twisted against the interlooped strands and eye 12 to form a secure interconnection and the desired rigidity in said eye.
Referring now to FIG. 5, there is shown the twisted configuration of section 28 prior to cutting and finishing the interlooped strand configuration. The end of section 28 is wrapped with tape or string 50 at the desired length to prevent twisting. The strands 34, 36 and 38 are next cut generally flush with the periphery of the twisted strands of section 28. Because of the particular interloop configuration described herein there are substantially no ridges or loose strands and strands 22 of eye 12 blend smoothly into the remainder of the pigging string 10. Moreover, the eye 12 is formed to rigidly extend from the body of the pigging string and resist bending or flexing as is a disadvantage in many prior art constructions.
Final assembly of the pigging string 10 includes finishing the surface of the twisted strands 22 with hot wax, or the like. If the pigging string 10 is formed of nylon as is preferable, then the ends of cut strands 34, 36 and 38 are first melted upon and into the twisted strands of section 28 with a hot iron. Then the pigging string 10 is immersed in a hot wax bath such as GULF No. 75. It has been found that a wax adapted for, and heated to, 250° F. will provide a more optimal coating in that the abnormally high heat induces the interlooped and twisted strands to "seat" more uniformly therealong. To render this effect permanent the pigging string 10 is put in tension while cooling. Generally, a period on the order of five minutes has been proven satisfactory. In the particular fabrication technique described herein and because the eye 12 is secured with only a single phase juncture, it is important to maximize tensile strength and maintain a uniform twist density. Were a different technique utilized for securing the eye 12, the post-stressed cooling would not be as integral to the pigging string construction. However, it has been observed that such treatment concommitantly imparts a hardness and a flexibility, or pliability, to the pigging string 10, which features are generally not compatible although very desirable.
The fabrication of the pigging string is facilitated greatly by the above technique. Conventionally, it has been deemed impractical to fabricate such a short, single purpose, rope member with an integrally formed eye 12. The method of the present invention provides not only an acceptable technique for accomplishing this but permits the construction of such a rope member with consistent twist density between the eye 12 and lower body thereof, herein referred to as section 28. Twist density, or the number of strand twists per inch, is an assembly parameter heretofore deemed problematic in pigging string fabrication. The most apparent reason is the intertwining of strands to form the eye 12. Obviously when strand twists must be separated to insert, or back-splice, the loop strand therein, twist density will be altered on either side of the splice, which may be multi-phase. In the present invention a single phase juncture effects the equivalent rigidity of a woven back-splice, in part because twist tension is applied only after the strands are interlooped and secured taut, prior to coating.
Final twisting of the pigging string 10, as shown in FIG. 5, is preferably accomplished by attaching, or hooking, the eye 12 to the first point of support from which strands 34, 36 and 38 were originally detached. In this manner the interlooped strands 22 are secured under tension and in the condition in which they will be used. The pigging string is then cut to a fixed length, generally on the order of five and one half feet to seven feet. Shorter ropes are not practical due to loop size and longer ropes provide unnecessary weight and imbalance. The average pigging string is thus six to six and one half feet in length with the average diameter on the order of 1/4 to 1/8 inch.
It is thus believed that the method and construction of the improved pigging string of the present invention will be apparent from the foregoing description. While the method and apparatus shown and described, have been characterized as being preferred, it will be obvious that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
|
A relatively short and improved multistranded rope member, commonly referred to as a pigging string, particularly adapted for rodeo applications and the like. The improved pigging string includes an integrally back spliced loop in one end thereof and is therein fabricated without twist bias to provide a smooth and reliable interconnection in a hard, yet pliable tying element for binding calves' feet during rodeo competition. The back splice is formed during twist fabrication of the pigging string in an intermediate section thereof and is so configured as to alleviate twist-ridges and loose strand lays which often interfere with maximum efficiency in use of pigging strings. Likewise, the pigging string is assembled in a taut configuration around the back spliced loop, then immersed in a preheated wax mixture prior to being post stressed during cooling. In this manner the pigging string provides the requisite tensile strength in a tightly wound, pliable embodiment affording a balanced use thereof as necessary where time is precisely recorded.
| 3
|
BACKGROUND OF THE INVENTION
This invention relates to a fitting having a split end, each segment of which forms a cantilever serving as jaws for clamping a workpiece within the body of the fitting. The clamping force is provided by the tightening of a nut of the invention with a camming surface being provided by another position of the fitting.
There are a variety of fittings available on the market today. One class of fittings, hydraulic or pneumatic fittings, involve deformation or flaring of the tube or workpiece on which they are applied; another class of fittings, Swage-Lock, require a wedging action by taper rings sealing the workpiece but again deforming the workpiece. A nut is generally used to provide the required compressional force.
Split head clamping fasteners have been known for some time, particularly in the field of electrical connectors. Patents illustrating such fasteners include U.S. Pat. Nos. 368,149; 1,802,381; 2,406,346; and 2,440,828 for holding electrical wires.
Although these prior art type of fittings and fasteners are useful, they have several drawbacks including the use of several mating parts, deformation of the workpiece, and multiple turns at high strength of the forcing nuts.
The present invention includes several advantages over the fittings and fasteners of the prior art. These advantages include the clamping action, which is achieved by a cantilever bending action rather than a high force requiring wedging action; the containment of the camming surface and nut as integral parts of the fitting; the non-movement of the workpiece or workpieces within the fitting as the clamping action takes place; the unitary construction of the fitting resulting in the lack of a requirement for several mating parts; the small amount of rotation, only a fraction of a turn of fitting nut is required for full clamping action; and the reusability of the fitting.
SUMMARY OF THE INVENTION
The invention seeks to provide a clamp action fitting with a split externally threaded, segmented end which minimizes the deficiencies of prior art fittings. The disclosed embodiments of the invention attain the clamping action by virtue of two simultaneous coactions; the first action occurs between a nut as it is being tightened on a threaded, segmented end of the fitting and a surface transverse to the longitudinal axis of the fitting, said surface being an integral part of the fitting; the second action occurs between the threads of the nut and the threads of the segmented end. Each end segment has a common thread.
The end of the fitting is segmented by two or more slots. Each of the segments forms a cantilever. As the face of the nut is moved into contact with said transverse surface, the nut experiences a reactive force directed against the nut's direction of forward motion. This reactive force is transmitted from the nut forward surface to the nut threads by the body of the nut. The nut's threads then exert a force on the externally threaded end segments of the fitting which results in a bending movement for each segment. This bending movement is generated in any cantilever.
The cantilevers or segments are thus forced inward by the force exerted on the segments thereby providing the clamping action. The fitting contains an axial passageway into which a workpiece, such as a tube, may be placed. A tube or other workpiece is rigidly held in place by the clamping action of the fitting. A principal advantage of the invention is that the workpiece is not forced to rotate or move in any way as said nut is tightened. The invention works on the basis of a clamping action as opposed to a wedging or deformation action which is characteristic of much of the prior art.
Each embodiment of the invention uses a clamping action involving only integral parts of the fitting so that the fitting is unitary; however, a fitting can have one split end or two or more split ends depending on the application. The slots dividing the end or ends into segments may be longitudinal through the axis or not, skewed, or of general curved form.
The body is not limited to the embodiments disclosed in this document.
BRIEF DESCRIPTION OF THE DRAWINGS
The many variables of the subject fitting are illustrated as follows:
FIG. 1 is an axial sectional view of the fitting including a nut, an "O" ring and the main body; the main body being made up of a split segmented end, a transversal surface, an external indentation, a remaining section, and a central axial passageway running the entire length of the main body. Also shown is a workpiece or tube which will be clamped by the fitting.
FIG. 2 presents a cross section of the fitting showing the split segmented end, each segment of the end forming a cantilever. The cross section of four such segments is shown. Also shown is a workpiece or tube to be clamped.
FIG. 3 is a side view of the fitting showing a partial view of one longitudinal slot.
FIG. 4 is a detail of the split segmented end of the embodiment of FIGS. 1, 2, and 3. Clearly shown is one segment in a side sectional view. This segment forms a cantilever secured at the point of the indentation. The external threads of the segment are shown as are the threads of the fitting nut. Also shown are some of the coacting forces of the invention which result in the clamping action.
FIG. 5 shows a side view of the fitting with ends segmented by skewed, curved, or longitudinal slots. The longitudinal slots shown in this figure do not pass through the center of the fitting. The longitudinal slots shown in FIG. 2 do pass through the central axis of the fitting.
FIG. 6 shows a view of another embodiment of the fitting. In this embodiment the fitting has two split segmented ends and two nuts so that two workpieces may be joined.
FIG. 7 shows a view of yet another embodiment of the fitting. In this embodiment the fitting has two split segmented ends and a main body shaped as an elbow. Two workpieces are also shown.
FIG. 8 shows an end view of a fitting wherein yet another slot, a cylindrical slot, is employed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The complete fitting embodiment shown in FIGS. 1-4 is designated 10 with a nut, 2, an "O" ring, 3; and a main body, 1; body 1 being subdivided into a split segmented end, 21, a transversal surface, 22, an external indentation, 23, serving to separate the segmented end, 21, and the transversal surface, 22; a remaining section, 24, and a central axial passageway, 25, running the entire length of the main body, 1. The split segmented end 21 is split into a plurality of segments by a plurality of slots, 8; each segment having a common external thread, 51, and each segment forming a cantilever; four such slots 8 and four such segments 7 are shown in the embodiment illustrated in FIG. 2. The split segmented end 21, of the main body 1 shown in FIG. 2, is divided into four equal segments by four longitudinal slots which are equidistantly spaced; however, more or less slots could be employed producing more or less segments respectively; a minimum of two slots is required.
FIG. 4 shows a detailed sectional view of a single segment, 7, from segmented end 21, a sectional view of external indentation 23, a sectional view of a portion of body 1 including transversal surface 22 and a sectional view of nut 2. The surface, 22, joining the indentation 23 to the rest of the body is a camming surface or reactive force surface for nut 2. Surface 22 is generally perpendicular to the axis 27 of axial passageway 25. Shown also in FIG. 4, in the sectional view of segment 7 are the external threads, 51, of segment 7. Each end segment, 7, is externally threaded. Shown also in FIG. 4 are the threads, 28, of nut 2 and a workpiece, in this case a tube, 4. Each of the end segments forms a cantilever, with threaded segment, 7, being the projected member of the cantilever and the member being supported at the indentation 23. The neutral axis, 9, of the cross section through indentation 23 for one end segment, 7, is shown in FIG. 2. The neutral axis reduces to a point, 12, in FIG. 4. A bending moment is generated in any cantilever.
In operation, fitting 10 clamps and holds a workpiece such as tube 4 in FIGS. 1 and 4 in place. The clamping action begins with the tightening of nut 2. As nut 2 is tightened, its leading edge, 29, approaches surface 22. When surface 29 contacts surface 22, a reactive force, 5, is produced; as nut 2 continues to be tightened, surface 22 acts as a camming surface. As is shown in FIG. 4, force 5 is transmitted via the body of nut 2 to the threads 51 of cantilever segment 7 resulting in the production of a plurality of forces of which only one force, 6, is numbered. Forces, 6, drive or move the segment or cantilever, 7, radially inward thus clamping the workpiece or tube 4 in place. This action is simultaneously produced in all end segments, 7, thus clamping the workpiece, 4, rigidly in place.
A key factor in clamping action is the magnitude of the distance, 30, shown in FIG. 4. The distance, 30, is distance from the point of strongest force, of type 6, application to the neutral axis projection, point 12. Force, of type 6, is not uniform along the threads, 13, and is strongest at thread surface 31. Thus the distances, 30 and 32, in FIG. 4 are of critical importance to the force level, 6, required for the onset and level or strength of the clamping action.
The forces, 6, prevent any axial motion of the tube, 4, when elevated pressure exists inside the tube and fitting. The "O" ring, 3, shown in FIG. 1, prevents the escape of any fluid flowing in tube 4 and fitting 10 if the fluid should infiltrate between the end of tube 4 and body 1.
In FIG. 2 the split segmented end of fitting 10 is shown to have four longitudinal slots in the preferred embodiment of FIGS. 1, 2, 3, and 4. The slots shown in FIG. 1 extend axially to point 12 of FIG. 4. In FIG. 5 another fitting embodiment is shown wherein the split segmented end 21 is segmented by various types of slots, 32. These slots are not radial in that they do not transect the central axis 27 of the axial passageway 25 as do slots 8. Slot 52, shown in FIG. 5, is a skewed slot which is neither longitudinal nor radial. Yet another type of slot is shown in FIG. 8. Slots 62 are of cylindrical shape, resulting in segments 53 of different shape. Clearly a plurality of slot designs are possible anyone of which can work with the bending clamping action of this invention.
Looking next at FIG. 6 there is illustrated a fitting embodiment, 33, with two split segmented ends, 34, 35; two camming or force reactive surfaces, 36, 37, two "O" rings, 38, 39; two indentations, 40, 41; and an axial passageway, 42, running from end to end of the fitting 33. Also shown in FIG. 6 is a workpiece connector, 43, which allows two workpieces, 44, 45, or tubes of the same size to be joined. Tubes 44 and 45 are clamped into place by the cantilever bending action of fitting 10 as nuts on ends 34 and 35 are tightened against camming surfaces 36 and 37 respectively.
Yet another fitting embodiment, 54, is shown in FIG. 7. Fitting embodiment 54 has two segmented ends, 55 and 56, and a main body, 57, which is bent into "elbow" form. Two camming or force reactive surfaces, 58 and 59, are used. Fitting embodiment 54 allows the joining of two workpieces, 60 and 61, which must be joined at an angle.
Clearly a wide variety of main body shapes may be used with the fitting of the invention. Other possible body shapes include, but are not limited to, reducer unions, female connectors, male and female elbows, tube tees, male and female side tees, male and female run tee, tube crosses, bulkhead unions, bulkhead elbows, and bulkhead tees.
Embodiments 10, 33, and 54 depend on a dual coaction of forces; the first of these coactions is that of a nut against a camming or reactive force surface, the second of these coactions is that of the threads of the nut upon the external threads of a cantilever segment. These two coactions result in the inward motion of the segments causing the segments to act as jaws and rigidly clamp the workpiece in place.
It is now believed that the unique construction features and coactions of the invention have been detailed for those skilled in the art not only to be able to understand and use the embodiments herein presented, but also to devise variations thereof which fall within the spirit and scope of the invention.
|
An externally commonly threaded split end fitting having a surface serving as a camming surface for an end-mounted nut. By advancing the nut along the split end of the fitting the camming surface reacting upon the nut causes a transmission of force through the nut onto the external threads of the split segmented end of the fitting causing in turn a radially inward pivoting of the jaw-like segments of the split head. The longitudinal axis of the fitting has a passageway for receiving a work piece, whereby the pivoting of the segments clamp the workpiece into the fitting. The fitting is unitary.
| 5
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/298,438 filed on Jan. 26, 2010, titled “Bacteriophage-Based Microorganism Diagnostic Assay Using Speed Or Acceleration Of Bacteriophage Reproduction,” the entire disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention relates generally to the field of identification of microscopic living organisms and more particularly to the identification of microorganisms using bacteriophage.
BACKGROUND OF THE INVENTION
[0003] Currently, bacteria that may be causing an infection or other health problem are identified by bacteria culture methods. Generally, it takes a day or several days to grow sufficient bacteria to enable the detection and identification of the bacteria. By that time, the person or persons infected by the bacteria may be very sick or even dead. Thus, there is a need for more rapid detection and identification of bacteria. Further, when bacterial infection is suspected, a physician will often prescribe a broad spectrum antibiotic. This has led to the development of antibiotic-resistant bacteria, which has further enhanced the need for more rapid identification of bacteria.
[0004] Bacteriophage are ubiquitous viruses that infect bacteria. Bacteriophage-based methods have been suggested as a method to accelerate bacterial identification. Bacteriophage are viruses that have evolved in nature to use bacteria as a means of replicating themselves. A bacteriophage (or phage) does this by attaching itself to a bacterium and injecting its genetic material into that bacterium, inducing it to replicate the phage from tens to thousands of times. Some bacteriophage, called “lytic bacteriophage,” rupture the host bacterium, releasing the progeny phage into the environment to seek out other bacteria. Thus, because of the sheer number of the bacteriophage after amplification, in principle it should be easier to detect the bacteriophage than to detect the bacteria. If, in addition the bacteriophage is specific to the bacteria, that is, if the bacteriophage amplification of a particular bacteriophage only occurs for specific bacteria, then the presence of amplified bacteria is then also an indication of the presence of the bacteria to which it is specific. Further, since the total incubation time for infection of a bacterium by parent phage, phage multiplication (amplification) in the bacterium to produce progeny phage, and release of the progeny phage after lysis can take as little as an hour after the bacteriophage find the bacteria depending on the phage, the bacterium, and the environmental conditions, in principle, bacteriophage amplification can result in much faster detection and identification of bacteria. See, for example, U.S. Pat. No. 5,985,596 issued Nov. 16, 1999 and No. 6,461,833 B1 issued Oct. 8, both to Stuart Mark Wilson; and Angelo J. Madonna, Sheila VanCuyk and Kent J. Voorhees, “Detection Of Esherichia Coli Using Immunomagnetic Separation And Bacteriophage Amplification Coupled With Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry”, Wiley InterScience , DOI:10.1002/rem.900, 24 Dec. 2002, which references are hereby incorporated by reference to the same extent as though fully disclosed herein. In summary, because bacteriophage are obligate bacterial parasites, their growth is fully dependent upon the presence of a suitable viable bacterial host. Bacteriophage amplification thus can be used as a surrogate marker for the identification and characterization of bacteria in a sample of interest, providing information that is of value in food, clinical, and environmental testing.
[0005] Bacteriophage amplification assays that depend upon amplification above a threshold level have been described: detection of bacteriophage at a concentration over a predetermined threshold is taken to indicate the presence of a suitable viable host in the sample.
[0006] In each of the methods of the above references, samples potentially containing target bacteria are incubated with bacteriophage, as specific as possible for those bacteria. In the presence of the bacteria, the bacteriophage infect the bacteria and replicate in the bacteria, resulting in the production of a measurable signal indicating the presence of the target bacteria. Some methods utilize the detection of progeny phage released from infected target bacteria as a means of detection and identification. In this case, progeny phage are not produced if the parent phage do not successfully infect the target bacteria. The degree to which the phage will infect the bacteria if the phage and bacteria are in the same sample is called “the infectious sensitivity of the phage.” Still other methods rely on the detection of phage replication products rather than whole progeny phage. For example, luciferase reporter bacteriophage produce luciferase when they successfully infect target bacteria. The luciferase then produces light that, if detected, indicates the presence of target bacteria in the sample. The promise of these methods has lead to much research on bacteriophage-based identification of microorganisms. However, as of this writing, the only commercially successful method of bacteriophage-based identification is a process in which the concentration of the bacteria is enhanced by a blood culturing process before or while the bacteriophage-based bacteria identification is performed.
[0007] In any method based on phage amplification, it is necessary to separate the signal that arises from the parent bacteriophage from the signal from the progeny bacteriophage. U.S. Pat. No. 5,498,525 issued Mar. 12, 1996 to Rees et al. solves this problem by destroying, removing, neutralizing, or inactivating the parent bacteriophage; and U.S. Pat. No. 7,166,425 issued Jan. 23, 2007 to Madonna et al. solves this problem by using a quantity of parent bacteriophage that is below the detection limit of the detection technology. However, to be sure that a lower level of bacteria are detected, the quantity of bacteriophage is kept as high as possible while still being under the detection limit.
[0008] To reliably detect a signal, the threshold must be significantly larger than the variability in initial bacteriophage concentration across sample runs. This variation can be attributed to many factors, including operator or manufacturing variability, dilution by sample, loss of activity over the test shelf life, or inhibition or neutralization by sample interferents.
[0009] Clearly, it would be highly desirable if a bacteriophage process could be provided that had increased selectivity, increased infectious sensitivity, and/or increased test sensitivity and still retained the fast detection of bacteria that is the promise of bacteriophage amplification methods, the potential of which has been driving research in this field.
BRIEF SUMMARY OF THE INVENTION
[0010] The invention solves the above problems, as well as other problems of the prior art, by employing the change in bacteriophage concentration over time, the curvature of a plot of bacteriophage concentration over time, or the change in the rate of change of bacteriophage concentration over time as the indicator of the presence of a specific bacterial host within the sample.
[0011] The invention provides a method of determining the presence or absence of a target microorganism in a sample to be tested, said method comprising: (a) combining with said sample an amount of bacteriophage capable of infecting said target microorganism to create a bacteriophage-exposed sample; (b) providing conditions to said bacteriophage-exposed sample sufficient to allow said bacteriophage to multiply in said target microorganism; and (c) assaying said bacteriophage-exposed sample to detect the time rate of change of a bacteriophage marker to determine the presence or absence of said target microorganism. Preferably, said microorganism is a bacterium, and said assaying comprises detecting said bacteriophage marker as an indication of the presence of said target bacterium in said sample. Preferably, said rate of change is the first time derivative or curvature of said bacteriophage marker. Preferably, said rate of change is the second time derivative of said bacteriophage marker. Preferably, said assaying comprises applying an algorithm that detects the slope of said marker. Preferably, the initial amount of said bacteriophage comprises a bacteriophage concentration of between 1×10 3 pfu/mL and 1×10 7 pfu/mL.
[0012] The invention also provides a method of determining the presence or absence of a target microorganism in a sample to be tested, said method comprising: (a) combining with said sample an amount of bacteriophage capable of infecting said target microorganism to create a bacteriophage-exposed sample; (b) providing conditions to said bacteriophage-exposed sample sufficient to allow said bacteriophage to multiply in said target microorganism; and (c) assaying said bacteriophage-exposed sample to detect the time rate of change of the time rate of change in a bacteriophage marker to determine the presence or absence of said target microorganism. Preferably, said microorganism is a bacterium and said assaying comprises detecting said bacteriophage marker as an indication of the presence of said target bacterium in said sample. Preferably, said assaying comprises applying an algorithm that detects the change in slope of said marker as a function of time. Preferably, the initial amount of said bacteriophage comprises a bacteriophage concentration of between 1×10 3 pfu/mL and 1×10 7 pfu/mL.
[0013] The invention solves the problem of the noisy bacteriophage marker signal while at the same time increasing the speed of bacterial identification. Numerous other features, objects, and advantages of the invention will become apparent from the following description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0014] FIG. 1 is a graph of bacteriophage concentration versus time for three different runs having different starting conditions; and
[0015] FIG. 2 is a graph of the first derivative of the three plot traces of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0016] In this disclosure, the terms “bacteriophage” and “phage” include bacteriophage, phage, mycobacteriophage (such as for TB and paraTB), mycophage (such as for fungi), mycoplasma phage or mycoplasmal phage, and any other term that refers to a virus that can invade living bacteria, fungi, mycoplasmas, protozoa, yeasts, and other microscopic living organisms and uses them to replicate itself. Here, “microscopic” means that the largest dimension is one millimeter or less. Bacteriophage are viruses that have evolved in nature to use bacteria as a means of replicating themselves. A phage does this by attaching itself to a bacterium and injecting its DNA (or RNA) into that bacterium, and inducing it to replicate the phage hundreds or even thousands of times. This is referred to as “phage amplification.”
[0017] Whether the bacteriophage has infected the bacteria is determined by an assay that can identify the change in concentration of a bacteriophage or bacterial marker or the change in the rate of change of a bacteriophage or bacterial marker. In this disclosure, a bacteriophage marker is any biological or organic element that can be associated with the presence of a bacteriophage. Without limitation, this may be the bacteriophage itself, a lipid incorporated into the phage structure, a protein associated with the bacteriophage, RNA or DNA associated with the bacteriophage, or any portion of any of the foregoing. In this disclosure, a bacterial marker is any biological or organic element that is released when a bacterium is lysed by a bacteriophage, including cell wall components, bacterial nucleic acids, proteins, enzymes, small molecules, or any portion of the foregoing. Preferably, the assay not only can identify the bacteriophage marker but also the quantity or concentration of the bacteriophage or bacterial marker and the change in the marker. In this disclosure, determining the quantity of a microorganism is equivalent to determining the concentration of the microorganism, since if you have one, you have the other, since the volume of the sample is nearly always known, and, if not known, can be determined. Determining the quantity or concentration of something can mean determining the number, the number per unit volume, determining a range wherein the number or number per unit volume lies, or determining that the number or concentration is below or above a certain critical threshold. Generally, in this art, the amount of a microorganism is given as a factor of ten, for example, 2.3×10 7 bacteriophage per milliliter (ml).
[0018] Some bacteriophage, called lytic bacteriophage, rupture the host bacterium, releasing the progeny phage into the environment to seek out other bacteria. The total reaction time for phage infection of a bacterium, phage multiplication, or amplification in the bacterium, through lysing of the bacterium takes anywhere from tens of minutes to hours, depending on the phage and bacterium in question and the environmental conditions. Once the bacterium is lysed, progeny phage are released into the environment along with all of the contents of the bacteria. The progeny phage will infect other bacteria that are present and repeat the cycle to create more phage and more bacterial debris. In this manner, the number of phage will increase exponentially until there are essentially no more bacteria to infect. The concept underlying the art of using bacteriophage to detect bacteria is that the huge numbers of phage that are created during phage amplification can be detected more easily than the much smaller number of bacteria; thus, phage amplification can be used to detect the presence of bacteria.
[0019] A fundamental principle that allows particular bacteria to be detected and identified via bacteriophage amplification followed by an assay of a bacteriophage marker is that a particular bacteriophage will, in principal, infect only a particular bacterium. That is, the bacteriophage is specific to the bacteria. Thus, if a particular bacteriophage that is specific to particular bacteria is introduced into a sample, and later the bacteriophage has been found to have multiplied, the bacteria to which the bacteriophage is specific must have been present in the sample. In this way, the prior art teaches that bacteriophage amplification can be used to identify specific bacteria present in a sample. However, the bacteriophage is rarely, if ever, 100% specific to a bacterium. In nature, bacteriophage tend to generally be 80% or less specific. This creates problems in bacterium detection and identification, and can be an additional factor that adds noise to the signal.
[0020] However, as indicated above, bacteriophage-based assays are inherently noisy. The present invention teaches a method of increasing the sensitivity and reliability of bacteriophage-based assays by using the change in bacteriophage concentration over time, i.e., the first derivative of the bacteriophage concentration or curvature, or a change in the rate of change in bacteriophage concentration over time, i.e., the second derivative of the bacteriophage concentration, as the signal that indicates bacteriophage growth, and thus the presence of a bacterial host in the sample, or more specifically, the presence of the bacteria to which the bacteriophage is specific.
[0021] FIG. 1 illustrates this principle. A plot of bacteriophage signal versus time for three different samples having initially different starting conditions, for example, and different concentrations of bacteriophage, is shown. The bacteriophage signal may be any measure of bacteriophage number or concentration. Generally, in this art, bacteriophage concentration is given in pfu/mL. For example, the initial concentration of one sample may be 1×10 6 pfu/mL; the initial concentration of another sample may be 3×10 6 pfu/mL; and the initial concentration of a third sample may be 7×10 6 pfu/mL. The range of bacteriophage initial concentration is preferably between 1×10 3 pfu/mL and 1×10 7 pfu/mL. More preferably, the initial amount of the bacteriophage is between 1×10 5 pfu/mL and 7×10 6 pfu/mL. Most preferably, the initial amount of the bacteriophage is between 2.5×10 6 pfu/mL and 4×10 6 pfu/mL. Because of the variance in initial levels, a reliable test based on an amplification threshold must use a threshold that is much larger above the mean initial level. Typically, this may be three standard deviations. A threshold-based test thus requires a minimal time of designated T T in FIG. 1 to detect amplification reliably. For the run 24 with the highest initial bacteriophage signal, which in this example has the highest concentration of bacteriophage, the time T T1 is the shortest, about 115 minutes. For the run 26 with the second highest signal, which in this case has the second highest initial concentration of bacteriophage, the time T T2 is longer, about 145 minutes; and the run 28 with the lowest signal, which in this case has the lowest initial concentration of bacteriophage, the time T T3 is about 155 minutes.
[0022] In contrast, an assay that monitors the change in bacteriophage levels over time is insensitive to variations in initial levels. Such an assay that detects a slope of a plot of a bacteriophage marker versus time, the curvature of a plot of the marker versus time, or a change in slope of a plot of the marker versus time, detects bacteriophage amplification more robustly and in less time, as designated T D in FIG. 2 , which in this case is about 105 minutes. It is noted that curve 30 is the same for all runs. It is evident that the lower the initial signal, the more the improvement in time to detection. Thus, the method of the invention is particularly useful for low initial signal levels or lower initial concentrations of bacteriophage. Since lower concentrations of bacteriophage can provide better signal to noise, the method of the invention is particularly effective. See United State patent application Ser. No. 12/066,806 filed Mar. 13, 2008, which is hereby incorporated by reference to the same extent as though fully disclosed herein.
[0023] The slope of a bacteriophage signal versus time, the curvature of the plot of the bacteriophage signal versus time, or a change in slope of the plot versus time, can be determined in many ways that are known in the art. We refer to the procedure for making one or more of these determinations as an “algorithm” herein. The algorithm may be as simple as simply taking measurements at time intervals and plotting them; or it may be by way of an instrument that detects the change in a bacteriophage measurement. Preferably, the plotting is done electronically. Preferably, the measurement is also taken electronically. For example, a plurality of lateral flow strips as described in United State patent application Ser. No. 12/402,337 filed Mar. 11, 2009 may be used to measure points on the curve. The flow strips may be read with an optical scanner. This patent application is hereby incorporated by reference to the same extent as though fully disclosed herein. A more sophisticated algorithm that can be used with any bacteriophage-based microorganism detection method is disclosed in United State Patent Application Publication No. US2010/0070185 on an invention of Ronald T. Kurnick and Martin Tiz, published on Mar. 18, 2010, which patent application is incorporated by reference to the same extent as though fully disclosed herein.
[0024] The bacteria detection processes using bacteriophage can be configured to determine antibiotic susceptibility of the target bacteria; and the invention is also applicable to such an antibiotic susceptibility test. For example, a sample potentially containing target bacteria is divided into two parts: Sample One and Sample Two. A phage amplification process or phage capture assay process measuring the change in bacteriophage concentration or change in the rate of change of the bacteriophage concentration described previously is performed on Sample One to ascertain the presence of the target bacteria in the sample. Samples One and Two are tested simultaneously or serially beginning with Sample One. If the presence of the target bacteria is already known via some other method, then Sample One is not needed nor is the associated phage assay. Sample Two is treated differently. An antibiotic is added to Sample Two at a specific concentration. Then Sample Two is optionally incubated for a predetermined period of time to allow the antibiotic to act upon the target bacteria. A reagent containing phage that is specific to the target bacteria is added to Sample Two; and Sample Two is incubated optionally for a predetermined time. The previously described phage amplification assay process or phage capture binding assay detection process measuring the change in bacteriophage concentration or change in the rate of change of the bacteriophage concentration is performed. If the target bacteria is resistant to the antibiotic, it will grow and a change in bacteriophage concentration or change in the rate of change of bacteriophage concentration is detected in the assay producing a positive result. The positive result indicates that the target bacterium is present in the assay; and the particular strain is resistant to the tested antibiotic. If the target bacterium is susceptible to the tested antibiotic, it will not grow in Sample Two; and the assay result will be negative. This result combined with a positive result on the assay performed on Sample One with no antibiotic will indicate that the target bacteria is present and that it is susceptible to the antibiotic.
[0025] Many other phage-based methods and apparatus used to identify the microorganism and/or to determine the antibiotic resistance test or antibiotic susceptibility can be enhanced by the method and apparatus of the invention. For example, a phage amplification process, such as a process described in US Patent Application Publication No. US2005/0003346 entitled “Apparatus And Method For Detecting Microscopic Living Organisms Using Bacteriophage” may be enhanced by the present invention. A process of attaching to a microorganism, such as described in PCT Patent Application Serial No. PCT/US06/12371 entitled “Apparatus And Method For Detecting Microorganisms Using Flagged Bacteriophage” may also be enhanced. Any other phage-based identification process may also be used.
[0026] There has been described an improvement to the conventional bacteria detection methods using bacteriophage that overcomes the problem of noise in the measurements. It should be understood that the particular embodiments shown in the drawings and described within this specification are for purposes of example and should not be construed to limit the invention, which will be described in the claims below. Further, it is evident that those skilled in the art may now make numerous uses and modifications of the specific embodiment described, without departing from the inventive concepts. Equivalent structures and processes may be substituted for the various structures and processes described; the subprocesses of the inventive method may, in some instances, be performed in a different order; or a variety of different materials and elements may be used. Consequently, the invention is to be construed as embracing each and every novel feature and novel combination of features present in and/or possessed by the microorganism detection apparatus and methods described.
|
A method of determining the presence or absence of a target microorganism in a sample to be tested, the method comprising: combining with the sample an amount of bacteriophage capable of infecting the target microorganism to create a bacteriophage-exposed sample; and measuring the time rate of change of the amount of said bacteriophage or the change in the rate of change of the amount of said bacteriophage as an indication of the presence or absence of the target microorganism as a function of time.
| 2
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a fuel supply apparatus, and more particularly to a fuel supply apparatus for supplying a fuel under a high pressure to a fuel injection type internal combustion engine, for example, an automobile engine.
[0003] 2. Description of the Related Art
[0004] FIGS. 8 to 14 are drawings describing a related art general fuel supply system for a fuel injection type internal combustion engine. FIG. 8 is a schematic illustration of this fuel supply system, FIG. 9 a sectional view of a principal portion of a fuel supply apparatus included in this fuel supply system, FIG. 10 a sectional view taken along the line X-X in FIG. 9, FIG. 11 a partial enlarged sectional view of what is shown in FIG. 9, taken along a plane Y-Z and illustrating the contacting condition of a driving cam and a tappet of the fuel supply apparatus, FIG. 12 a sectional view taken along a plane Y-X with respect to the plane Y-Z in FIG. 11, FIG. 13 a graph showing the condition of the deformation of a pressure receiving surface of the tappet which receives a force of the driving cam, and FIG. 14 a graph showing the condition of the distribution of Hertz stress on the pressure receiving surface.
[0005] Referring to FIGS. 8 to 9 , the fuel supply system includes a fuel tank 1 , a fuel supply apparatus 6 and fuel injection valves 10 as main elements, the fuel supply apparatus 6 having a filter 11 , a low-pressure damper 12 , a suction valve 13 , an electromagnetic valve 17 , a pump 16 , and a discharge valve 14 .
[0006] Fuel 2 in the fuel tank 1 is sent out by the low-pressure pump 3 , pressure regulated by a low-pressure regulator 5 via the filter 4 , and supplied to the fuel supply apparatus 6 . Only such a quantity of the fuel 2 thus supplied to the apparatus that is necessary for fuel injection is pressure-increased by the fuel supply apparatus 6 , and supplied to a common rail 9 of an internal combustion engine (not shown), the fuel being then injected as a high-pressure atomized fuel from the fuel injection valves 10 into cylinders (not shown) of the internal combustion engine. The quantity of fuel needed during this time is determined by a control unit (not shown) and controlled by the electromagnetic valve 17 , and an excess fuel is discharged from the electromagnetic valve 17 to the portion of a fuel passage which is between the low-pressure damper 12 and suction valve 13 . A reference numeral 7 in FIG. 8 denotes a filter, and 8 a high-pressure relief valve, which is opened when the pressure in the interior of the common rail becomes abnormally high, to prevent the common rail 9 and fuel injection valve 10 from being broken.
[0007] Referring to FIG. 9 showing a principal portion of the fuel supply apparatus 6 , the pump 16 includes a cylinder 25 incorporated in a cylinder casing 30 and provided with a pressure chamber 24 therein which has a fuel suction port 22 and a fuel discharge port 23 ; a piston 26 moving slidingly in the axial direction thereof in the cylinder 25 to vary the volume of the pressure chamber 24 ; a columnar tappet 28 joined to the piston 26 ; and a bolt 29 fitted slidably around the tappet 28 and having a threaded portion engaged with the cylinder casing 30 . Referring to FIGS. 10 to 12 , a driving cam 41 mounted on a cam shaft 40 of the engine contacts a pressure receiving surface 28 a at a lower end in the drawing of the tappet 28 , and a rotational force of the driving cam 41 occurring due to the rotation of the cam shaft 40 is transmitted to the tappet 28 and piston 26 via the pressure receiving surface 28 a as a driving force. Owing to the driving force thus transmitted to the piston 26 , the piston 26 is moved vertically to vary the volume of the pressure chamber 24 .
[0008] A surface 261 , which contacts the tappet 28 , of the piston 26 bulges slightly toward the tappet 28 as shown in FIGS. 11 and 12. The reason why the surface 261 is thus bulged resides in that, when the tappet 28 is moved slidingly in the axial direction owing to the rotation of the driving cam 41 , inclination of the tappet 28 occurs due to a clearance set between the tappet 28 and bolt 29 , which inclination reduces a lateral force transmitted from an upper surface 28 b of the tappet 28 to the piston 26 .
[0009] Referring to FIG. 11, all of arrows a, b, c represent positions from which a force from the driving cam 41 is applied to the pressure receiving surface 28 a . Out of these arrows, the arrow b represents a position from which the force is applied to the portion of the pressure receiving surface 28 a which is close to the center thereof, while both of the arrows a, c represent positions from which the force is applied to the portions of the pressure receiving surface 28 a which are on somewhat inner side of the outer circumference thereof. As shown in FIG. 11, the driving cam 42 is generally formed wider than the tappet 28 . In an initial stage of an operation of the driving cam 41 , the condition of the application of the force by the driving cam 41 to the receiving surface 28 a is uniform over the whole of the same surface 28 a . Accordingly, the levels of the force applied to the force applying positions represented by the arrows a, b, c are also uniform.
[0010] However, as described above, the portion of the upper surface 28 b of the tappet 28 which is around the force applying position represented by the arrow b contacts the bulging portion of the surface 261 of the piston 26 , while the portions of this surface 28 b which are around the force applying positions of the arrows a, c have a narrow clearance between the upper surface 28 b and the surface 261 . Due to the existence of this clearance, the pressure receiving surface 28 a is deformed as shown by a solid line in FIG. 13, and the distribution of Hertz stress during this time becomes as shown by a solid line in FIG. 14. FIGS. 13 and 14 show data obtained when a fuel discharge pressure is as high as 15 MPa.
[0011] What are shown in FIGS. 13 and 14 will now be described. The lateral axis of each of FIGS. 13 and 14 represents a position of the tappet 28 in the direction of Z-axis, and the longitudinal axis of each of FIGS. 13 and 14 a displacement distance (μm) based on the deformation of the pressure receiving surface 28 a and measured from an initial position thereof, and Hertz stress (MPa). Each of the solid curves in FIGS. 13 and 14 shows the distribution of Hertz stress recorded when the fuel discharge pressure is 15 MPa. The a, b, c in each of these drawings represent displacement distances (FIG. 13) and Hertz stress (FIG. 14) in the force applying positions of the arrows a, b, c. As is clear from FIG. 13, the displacement distance becomes maximal around the positions of arrows a, c, and decreases at an outer circumference. As a result, the Hertz stress becomes maximal at inflexion points of the displacement distance around the arrows a, c as is clear from FIG. 13.
[0012] When the fuel discharge pressure is thus high, the abrasion of the driving cam 41 and tappet 28 increases due to the high Hertz stress occurring locally in positions around those of the arrows a, c, i.e. the positions near the outer circumference of the pressure receiving surface 28 a . In order to deal with this problem, the related techniques employed a method of reducing Hertz stress by increasing the outer diameter of the tappet 28 and the width and outer diameter of the driving cam 41 , but this method caused the dimensions and weight of the fuel supply apparatus 6 to increase.
SUMMARY OF THE INVENTION
[0013] The present invention has been made in view of the above-mentioned circumstances, and provides a fuel supply apparatus capable of reducing the abrasion of a driving cam and a tappet without increasing the dimensions and weight of the apparatus.
[0014] The fuel supply apparatus for supplying a fuel to an engine according to the present invention includes a cylinder, a piston and a tappet. The cylinder is provided with a fuel pressurization chamber having a fuel suction port and a fuel discharge port. The piston is moving slidingly in the axial direction thereof in the cylinder and thereby increasing and decreasing the volume of the fuel pressurization chamber. The tappet has a pressure receiving surface for contacting a driving cam of the engine and receiving a driving force of the driving cam, and which transmits the driving force to the piston. The tappet has a groove on its outer surface. The groove is positioned in the region which corresponds to the vicinity of an outer circumference of the pressure receiving surface for preventing the local concentration of stress thereon. Accordingly, the groove gives an easily deformable portion of a low rigidity. The easily deformable portion is positioned in the region which corresponds to the vicinity of the outer circumference of the pressure receiving surface. The easily deformable portion works to relax the Hertz stress, and, owing to this action of the easily deformable portion, an effect of reducing the abrasion of the driving cam and tappet is obtained.
[0015] Preferably, in the fuel supply apparatus, the tappet includes a larger-diameter portion and a smaller-diameter portion. The larger diameter portion is engaged with a tappet stopper provided on an opened end portion of a cylinder casing. The smaller-diameter portion is capable of passing through the tappet stopper and has the pressure receiving surface. The groove is formed on the outer surface of the smaller-diameter portion.
[0016] Still preferably, in the fuel supply apparatus, the tappet has a board-like portion between the pressure-receiving surface and the groove. Accordingly, the board-like portion functions as a pressure receiving portion which effectively receives the driving force from the driving cam.
[0017] Still preferably, the fuel supply apparatus in which the outer diameter of the larger-diameter portion is 10 mm to 15 mm with the thickness of the board-like portion is 0.5 mm to 1.5 mm. Accordingly, the board-like portion functions as a pressure receiving portion which effectively receives the driving force from the driving cam, without being broken even when the board-like portion receives the driving force from the driving cam.
[0018] Still preferably, the fuel supply apparatus in which the depth of the groove measured from the outer surface of the lager-diameter portion is 0.5 mm to 2 mm.
[0019] Still preferably, the fuel supply apparatus in which the groove has a V-shaped, semicircular or U-shaped cross section. Accordingly, the easily deformable portion given by the groove maintains a low rigidity and, moreover, does not have the problem of the occurrence of the breakage thereof even when the easily deformable portion receives the driving force from the driving cam.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Preferred embodiments of the present invention will now be described in detail with reference to the following figures, wherein:
[0021] [0021]FIG. 1 is a sectional view of a first embodiment of the fuel supply apparatus according to the present invention;
[0022] [0022]FIG. 2 is a partial enlarged sectional view of what is shown in FIG. 1;
[0023] [0023]FIG. 3 is another partial enlarged sectional view of what is shown in FIG. 1;
[0024] [0024]FIG. 4 is a graph showing the condition of the deformation of a pressure receiving surface of a tappet;
[0025] [0025]FIG. 5 is a graph showing the condition of the distribution of Hertz stress on the pressure receiving surface;
[0026] [0026]FIG. 6 is a sectional view of a tappet used in a second embodiment of the fuel supply apparatus according to the present invention;
[0027] [0027]FIG. 7 is a sectional view of a tappet used in a third embodiment of the fuel supply apparatus according to the present invention;
[0028] [0028]FIG. 8 is a schematic illustration of a related art fuel supply system;
[0029] [0029]FIG. 9 is a sectional view of a related art fuel supply apparatus;
[0030] [0030]FIG. 10 is a sectional view taken along the line X-X in FIG. 9;
[0031] [0031]FIG. 11 is a partial enlarged sectional view of what is shown in FIG. 9;
[0032] [0032]FIG. 12 is another partial enlarged sectional view of what is shown in FIG. 9;
[0033] [0033]FIG. 13 is a graph showing the condition of the deformation of a pressure receiving surface of a related art tappet; and
[0034] [0034]FIG. 14 is a graph showing the condition of the distribution of Hertz stress on the related art pressure receiving surface.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] In the following description, the parts identical with those of the above-described related art fuel supply apparatus and previously-described embodiments will be designated by the same reference numerals and the description thereof will be omitted in some cases.
[0036] First Embodiment
[0037] FIGS. 1 to 5 illustrate a first embodiment of the fuel supply apparatus according to the present invention. FIG. 1 is a sectional view of a principal portion of the fuel supply apparatus, FIG. 2 a partial enlarged sectional view taken along a plane Y-Z and illustrating the condition of the driving cam and tappet in contact with each other, FIG. 3 a sectional view taken along a plane Y-X with respect to the plane Y-Z in FIG. 2, FIG. 4 a graph showing the condition of the deformation of a pressure receiving surface of the tappet which receives a force of the driving cam, and FIG. 5 a graph showing the condition of the distribution of Hertz stress on the pressure receiving surface. What are meant by the lateral axis, longitudinal axis, and reference letters a, b, c in FIGS. 4 and 5 are the same as those in FIGS. 13 and 14. A thick curve G 1 in FIG. 4 and that G 3 in FIG. 5 represent the distribution of Hertz stress in the first embodiment which are recorded when a discharge pressure of the fuel is 15 MPa, and a thin curve G 2 in FIG. 4 and that G 4 in FIG. 5 are the reproduction of the curves shown in FIGS. 13 and 14.
[0038] Referring to FIGS. 1 to 3 , especially, FIG. 3, a columnar tappet 28 has an outer surface 28 c , and includes a larger-diameter portion 281 and a smaller-diameter portion 282 , the portion of the outer surface 28 c which corresponds to the smaller-diameter portion 282 being provided with an annular groove 5 which extends around a circumference of the outer surface. A board-like portion 284 is provided between the groove 5 and pressure receiving surface 28 a , and a lower surface in the drawing of the board-like portion forms the pressure receiving surface 28 a . The board-like portion 284 substantially functions as a pressure receiving portion which receives a driving force from a driving cam 41 . Referring to FIG. 2, a reference symbol L 1 denotes the length of the larger-diameter portion 281 , L 2 the length of the smaller-diameter portion, R 1 the outer diameter of the larger-diameter portion 281 , R 2 the outer diameter of the smaller-diameter portion 282 , T 1 the thickness of the board-like portion 284 , T 2 the thickness of a thin portion 283 existing between a bottom of the groove 5 and the board-like portion 284 , D the depth of the groove 5 measured from the side surface 28 c of the larger-diameter portion 281 , and θ the angle of inclination of an inclined surface of the portion of the groove 5 which is on the side of the board-like portion 284 , in other words, an inclined surface of the thin portion 283 .
[0039] The effect of the provision of the groove 5 will now be described. Providing the groove 5 causes the thin portion 283 and board-like portion 284 to be formed on the smaller-diameter portion 282 . The outer circumferences and their near-by parts (which will hereinafter be referred to as easily deformable parts) of the thin portion 283 and board-like portion 284 are made thin and have a low rigidity. Therefore, when the pressure receiving surface 28 a or board-like portion 284 receives the driving force from the driving cam 41 , the easily deformable parts, in other words, the force applying positions indicated by arrows a and c are deformed at the outer circumference more greatly than those indicated by arrows a, c in FIG. 2. The curve G 1 in FIG. 4 indicates the condition of this deformation. The curve G 1 does not have inflexion points in regions of arrows a, c, as compared with the curve G 2 , but clearly shows that the deformation of the pressure receiving surface occurs increasingly in a monotonous manner toward an outer circumference thereof, at which the greatest deformation occurs. Since an inflexion point representing the occurrence of such large deformation does not appear, the Hertz stress in the force applying positions of the arrows a, c is sufficiently low as compared with that in the corresponding positions shown on the curve G 4 as is clear from the curve G 3 in FIG. 5. Therefore, it is understood that the stress relaxation with respect to the above-mentioned deformed shape of the pressure receiving surface has been achieved. The achievement of this stress relaxation is an effect obtained by the provision of the groove 5 . Owing to this effect, the abrasion of the driving cam 1 and tappet 28 is reduced, and the solving of the above-mentioned object of the present invention has thus come to be attained.
[0040] In order to prevent the tappet from falling from the cylinder casing 30 during the assembling of the fuel supply apparatus 6 , the tappet 28 includes the larger-diameter portion 281 having the outer diameter slightly larger than the inner diameter of a tappet stopper 31 provided in an opened portion of the cylinder casing 30 ; and the smaller-diameter portion 282 having the outer diameter slightly smaller than the mentioned inner diameter. During the assembling of the fuel supply apparatus 6 , the tappet 28 is inserted through the cylinder casing 30 from an upper side thereof in the drawing. When the tappet 28 is thus inserted through the cylinder casing 30 , the larger-diameter portion 281 alone is held in the cylinder casing 30 , and the smaller-diameter portion 282 passes through the tappet stopper 31 to be put in the condition shown in FIGS. 1 to 3 . In the first embodiment, the groove 5 is provided over substantially the whole region of the outer surface of the smaller-diameter portion 282 except the region thereof which corresponds to the board-like portion 284 , and has a V-shaped cross section.
[0041] When the depth D of the groove 5 and the size of the opened portion are small with the thickness of the easily deformable portion being large, the rigidity of the easily deformable portion is still large. Therefore, the degree of the above-mentioned deformation (degree of stress relaxation) becomes insufficient, so that the effect of the groove 5 becomes poor. Conversely, when the depth D of the groove 5 is excessively large with the thickness of the easily deformable portion being excessively small, the grooved portion is broken in some cases due to the force of the driving cam 41 . Therefore, it is preferable that the depth D of the groove 5 and the size of the opened portion be at levels between excessively high levels and excessively low levels. Such intermediate levels can be set generally by an analysis based on a rule of trial and error or a finite element method when the size of the tappet 28 are determined.
[0042] Apart from the determining by a rule of trial and error of the depth and size mentioned above, examples of optimum values of the size of the tappet 28 , thickness T 2 of the thin portion 283 and other sizes will be shown on the basis of FIG. 2. When the length L 1 of the larger-diameter portion 281 of the tappet 28 is around 15 mm to 20 mm with R 1 around 10 mm to 15 mm, the length L 2 is around 4 mm to 5 mm, a difference between R 1 and R 2 around 0.05 mm to 0.2 mm, the thickness T 1 around 0.5 mm to 1.5 mm and preferably around 0.5 mm to 1.2 mm, an angle θ of inclination around 30 to 60 degrees, the thickness T 2 of the thin portion 283 around 1 mm to 2 mm, and D around 0.5 mm to 2 mm.
[0043] According to the present invention, the groove 5 is provided basically in the portion of the outer surface 28 c of the tappet which is close to the outer circumference of the pressure receiving surface 28 a . However, when the groove 5 is provided excessively close to the mentioned outer circumference, the thickness of the board-like portion 284 becomes excessively small, so that the board-like portion 284 is easily broken due to the force of the driving cam 41 . Therefore, it is preferable that the groove 5 be provided in a position in which the board-like portion 284 can secure the thickness of around the above-mentioned level.
[0044] Second Embodiment
[0045] [0045]FIG. 6 illustrates a second embodiment of the fuel supply apparatus according to the present invention, and is a sectional view of a tappet 28 only. The sectional views of a principal portion of the second embodiment of the fuel supply apparatus will be omitted since these sectional views except a sectional view of a tappet 28 are identical with FIGS. 1 to 3 .
[0046] The second embodiment differs from the first embodiment only in the cross-sectional shape of a smaller-diameter portion 282 of the tappet 28 , and the construction of the remaining portions of the former is identical with that of the corresponding portions of the latter. An annular groove 5 in the second embodiment has a semicircular cross-sectional shape, and the depth D thereof is equal to that of the groove 5 of the first embodiment. Although the size of an opened portion in the second embodiment is set somewhat smaller with the thickness T 1 of a board-like portion 284 set somewhat larger to around 0.8 mm to 1.5 mm, the same operation and effect as in the first embodiment are obtained.
[0047] Third Embodiment
[0048] [0048]FIG. 7 illustrates a third embodiment of the fuel supply apparatus according to the present invention, and is a sectional view of a tappet 28 only. The sectional views of a principal portion of the third embodiment of the fuel supply apparatus will be omitted since these sectional views except a sectional view of the tappet 28 are identical with FIGS. 1 to 3 .
[0049] The third embodiment differs from the first and second embodiments in only the cross-sectional shapes of a smaller-diameter portion 282 of the tappet 28 , and the construction of the remaining portions of the former is identical with that of the corresponding portions of the latter. An annular groove 5 in the third embodiment extends over the whole region of a smaller-diameter portion 282 except the region thereof which corresponds to the thickness of a board-like portion 284 , and has a U-shaped, especially, flat-bottomed U-shaped cross-sectional shape. The thickness of the board-like portion 284 is around 0.8 mm to 1.5 mm which is equal to that of the same portion in the second embodiment. Only an outer circumferential portion of the board-like portion 284 functions as an easily deformable portion, and the operation and effect identical with those of the first embodiment is obtained.
[0050] The present invention is not limited to the above-described first, second and third embodiments but includes various modes of modifications in conformity with the spirits of the problem-solving method used in the present invention.
|
A fuel supply apparatus capable of reducing the abrasion of a driving cam and a tappet without increasing the dimensions and weight of the apparatus. This fuel supply apparatus is provided with a tappet which has a pressure receiving surface contacting the driving cam of an engine. The tappet is provided at the part of a outer surface thereof which is in the vicinity of an outer circumference of the pressure receiving surface with a groove adapted to prevent the local concentration of stress on the tappet and having a V-shaped, semicircular or U-shaped cross section.
| 8
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.