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TECHNICAL FIELD
The present invention relates to a starch composition containing a high proportion of so-called "resistant starch" (RS). The composition of the resistant starch is further characterised by a specific chain length distribution of the RS-fraction and by a relatively low specific Differential Scanning Chromatography (DSC) melting peak temperature. The composition furthermore shows a specific fermentation pattern resulting in an increased level of n-butyrate.
BACKGROUND OF THE INVENTION
It has been known for some years that a part of the starch contained in the human diet can pass the small intestine without being digested. This fraction of the food starch is called resistant starch. Different forms of starch have been found to be resistant to digestion. A classification of resistant starches has been given by Englyst and Cummings (Am. J. Clin. Nutr. (1987) 45 423-431). These authors distinguish between three types of resistant starches:
Type 1. Physically indigestible starch e.g. partially milled grains and seeds,
Type 2. Resistant starch granules e.g. raw potato, green banana,
Type 3. Retrograded starch e.g. cooled-cooked potato, bread, and cornflakes.
Effective enrichment of food with RS is possible by addition of processed starch containing a large percentage of retrograded structures. Starch is composed of amylose and amylopectin. The extent of retrogradation is known to be a function of the amylose content. Heating and cooling of amylose gives rise to resistant starch. Due to the branched structure of amylopectin the amount of resistant starch which is formed is decreasing with an increase in the amount of amylopectin in starch. The amount of RS can however be increased by debranching the amylopectin prior to heating. In view of the above high amylose (maize) starches have been chosen as the primary source of resistant starch for the first commercial high RS-products.
Carbohydrates which are not enzymatically digested in the small intestine reach the colon where they are fermented by the anaerobic microflora. Such carbohydrates include non-starch polysaccharides, resistant starch (RS), indigestible oligosaccharides and endogenous polysaccharides from mucus. The undigested starch fraction reaches the colon where it becomes a substrate for microbial fermentation. Besides gas production (H 2 , CH 4 , CO) different short chain fatty acids (SCFA) are formed depending on the type of carbohydrate.
The major end products of bacterial carbohydrate breakdown are short-chain fatty acids (SCFA: acetate, propionate and n-butyrate). SCFA are rapidly taken up by the colonic epithelial cells. Propionate and acetate are released by the basolateral membrane to the portal circulation and may have an effect far from their production site. n-Butyrate serves as energy yielding substrate in the colonocytes and additionally affects several cellular functions e.g. proliferation, membrane synthesis and sodium absorption.
Acetate, propionate and n-butyrate are the main SCFA produced from indigestible oligo- and polysaccharides the relative amounts of these fatty acids depend on the type of carbohydrate. SCFA are produced in the proximal colon in an average ratio of acetate:propionate: n-butyrate equivalent to 60:25:10 and in amounts of mmol/L. This ratio however is riot constant but is determined by the kind of substrate fermented. It has been shown both in vitro and in vivo that the fermentation of starch yields high levels of n-butyrate. The observations that ceacal SCFA levels are decreased by raw potato starch (Mallett et al. (1988) Brit. J. Nutr. 60, 597-604; Levrat et al.(1991), J. Nutr. Biochem.2, 31-36; Mathers et al., (1991) Brit. J. Nutr.66, 313-329) but increased by high amylose corn starch underline that different forms of RS have different effects in terms of n-butyrate production in the colon.
According to Wyatt and Horn (1988) J. Sci. Food Agric. 44, 281-288, RS-fractions of retrograded pea and corn starch respectively show quantitative differences in in vitro fermentation but without qualitative changes in SCFA composition. Six different raw starches also showed different in vitro fermentation kinetics. At the same time the molar n-butyrate proportion was not altered. Several independent in vivo animal studies confirm this. Thus the source of RS is important for the fermentability and hence for the amount of n-butyrate obtained but apparently not for the relative amount.
Compared with indigestible polysaccharides such as arabinogalactan, xylan and pectin, RS produces a significantly larger molar amount of n-butyrate (Englyst et. al. (1987) in I. D. Morton: "Cereals in a European Context", Chichester, UK, Ellis Horwood Ltd., pp. 221-223). This is considered important because of the general acceptance that n-butyrate plays a major role in the prevention of intestinal cancers (e.g. colorectal cancer) as recently summarised by Smith and German (Food Technology, (1995 November) 87-90). n-Butyrate appears to be a preferred substrate for normal colonocytes and assists in the maintenance of colonic integrity.
n-Butyrate inhibits growth of colon cancer cell lines. At the molecular level, n-butyrate causes histone acetylation, favours differentiation, induces apoptosis and regulates the expression of various oncogenes. In vivo n-butyrate increases immunogenicity of colon cancer cells.
Only indigestible polysaccharides which are associated with production of high n-butyrate concentrations in the distal large bowel (wheat bran, retrograded high amylose starch (type 3 RS)) were found to be protective against colorectal cancer in a rat model system wherein rats were treated with 1,2-dimethylhydrazine (McIntyre et al. (1993), Gut 34, 386-391; Young et al. (1996), Gastroenterology 110(2): 508-514). Oat bran, guar gum, raw potato starch (type 2 RS), cellulose and starch-free wheat bran have no protective effect in this model of colorectal cancer (McIntyre et al. (1993), Gut 34, 386-391, Young et al. (1996), Gastroenterology 110(2): 508-514).
From the above studies it appears that the amount of n-butyrate produced in the colon is important. What is needed for a maximal physiological benefit is not only a starch product with a high amount of RS, but a well fermentable RS-fraction producing high amounts of SCFA with an elevated n-butyrate level. Methods for the preparation of resistant starch have for example been disclosed in the following publications.
European patent application EP 688,872 discloses a method for obtaining increased levels of resistant starch. It is demonstrated that the highest amounts of RS are obtained when after enzymatic digestion, retrogradation is performed for a prolonged period of time and at a relatively low temperature. The maximum amount of RS which could be obtained was 51.8% (example 3 therein).
International patent application WO 91/07106 discloses a method for obtaining resistant starch wherein a retrogradation step is followed by enzymatic hydrolysis. The retrogradation step is performed at low temperature for amylose at 4° C. and for starch at 8° C. as mentioned on page 13. Moreover the process starts with undegraded starch which may be prior treated by a debranching enzyme.
European patent application EP 564893 discloses a method for obtaining resistant starch starting from a non-degraded high amylose starch. The DSC melting peak temperature of this product is mentioned to be in the range of 115-135° C. and the amount of resistant starch is below 51% and is correlated with the percentage of amylose used in the starting product.
There exists a need for a starch-based product which is highly fermentable and which gives rise to an increased amount of n-butyrate in the colon. The present invention provides such a starch-based product.
SUMMARY OF THE INVENTION
The present invention discloses a starch-based composition which is characterised in that it contains a high amount of resistant starch. The composition consists of partially degraded starch which has undergone a retrogradation process and contains at least 55% (w/w) pancreatine resistant starch. Preferably, the amount of resistant starch is at least 60%. The resistant starch fraction is characterised by a degree of polymerisation of predominantly between 10 and 35 and a DSC peak temperature of below 115° C., preferably between 90 and 114° C.
The partially degraded starch can be obtained by partial amylolytic or acid hydrolysis of starch followed by enzymatic debranching. A preferred partially degraded starch which is used as a starting product is a maltodextrin with a dextrose equivalent (DE) below 10 obtained by partial alpha-amylase degradation and additionally treated with isoamylase. The present invention also discloses a method for obtaining the starch-based compositions. The method comprises the following steps:
a) thinning of the starch,
b) enzymatic debranching of the thinned starch,
c) inactivation of the enzyme,
d) drying of the composition.
Step b) is preferably accompanied by retrogradation.
Preferably the high amount of resistant starch is obtained without a separate retrogradation step at low temperature.
The present invention further discloses the use of the partially degraded retrograded starches in the preparation of food or feed compositions and food or feed compositions containing the starch-based composition.
Finally, the invention discloses the use of partially degraded retrograded starch composition to prevent or treat diseases of the colorectal digestive tract.
DESCRIPTION OF THE FIGURES
FIG. 1 is an example of a DIONEX chromatogram of the resistant starch fraction of the present invention obtained by exhaustive pancreatine digestion of debranched potato maltodextrin (IRP) (measured according to Carbohydr. Res. 215 (1991) 179-192).
FIG. 2 shows the change of pH in time during in vitro fermentation of the RS fractions of Novelose™, Euresta and IRP.
FIG. 3 shows the formation of short-chain fatty acids during in vitro fermentation of Novelose™, Euresta and IRP.
FIG. 4 shows the formation of n-butyrate during in vitro fermentation of Novelose™, Euresta and IRP.
FIG. 5 shows DSC curves of milk drink residues obtained after pancreatine digestion for standard milk and milk with added IRP.
DETAILED DESCRIPTION OF THE INVENTION
The present invention discloses a starch-based composition which is characterised in that it contains a high amount of resistant starch. The composition consists of partially degraded starch which has undergone a retrogradation process and contains at least 55% (w/w) pancreatine resistant starch. Preferably, the amount of resistant starch is at least 60%. The resistant starch fraction is characterised by containing alpha-glucans with a degree of polymerisation of predominantly between 10 and 35 and a DSC peak temperature below 115° C., preferably between 90-114° C. The partially degraded starch can be obtained by amylolytic or acid degradation of starch followed by enzymatic debranching. A preferred partially degraded starch is a maltodextrin obtained by partial alpha-amylase degradation and treated with a debranching enzyme.
The partially degraded starches for use as a starting material of the present invention are obtainable from any suitable starch source. Useful starches are obtained from potato, wheat, tapioca and maize high amylose starches which are converted to maltodextrins have also been used.
The present invention also discloses a method for obtaining the starch-based compositions of this invention. The method comprises the following steps:
a) thinning of the starch,
b) enzymatic debranching of the thinned starch,
c) inactivation of the enzyme,
d) drying of the composition.
The debranching is achieved by using a suitable enzyme such as isoamylase or pullulanase, preferably by isoamylase
Step b) is preferably accompanied by retrogradation. Alternatively the starch may be retrograded after enzyme inactivation.
A preferred process for obtaining the products of the present invention contains the following steps:
a) maltodextrins (DE<10, preferably DE<5) are dissolved in water,
b) the pH is adjusted and the solution is cooled to a optimum temperature for the activity of a debranching enzyme,
c) the debranching enzyme is added and the mixture is incubated,
d) the enzyme is inactivated,
e) the mixture is spray-dried
f) the resistant starch is collected and optionally grinded.
Preferably the maltodextrin is potato or tapioca maltodextrin.
The process of the present invention starts from a partially degraded starch product. Contrary to known processes it was found that no separate retrogradation step is required. Retrogradation occurs at the same time as debranching. This results in a more economical process as the retrogradation used to be performed during a prolonged period (up to 48 hours) at a low temperature. The process is therefore faster and cheaper.
Furthermore the product obtained by the invented process contains a relatively high amount of resistant starch. It was found that this product gives a higher production of n-butyrate both relatively with respect to the other short chain fatty acids and in absolute terms than other known products.
The present invention further discloses the use of the partially degraded retrograded starches in the preparation of food or feed compositions and food or feed compositions containing the starch-based composition. The resistant starch product is added to the food or feed composition in an amount of up to 20% (w/w), preferably of up to 10%. Food preparations to which the starch-based composition of the present invention is added include, biscuits, toast, milk desserts up to 10% of the starch-based composition of claim 1.
It is shown that heating during the preparation of the food product does not significantly destroy the product. This means that sufficient RS survives the treatment of food preparation including UHT treatment and baking at 195° C.
The invention also discloses the use of debranched/retrograded maltodextrins in the prevention of diseases of the colorectal digestive tract. On the basis of the finding that n-butyrate plays a major role in the prevention of intestinal cancers (e.g. colorectal cancer) as recently summarised by Smith and German (Food Technology, 1995 (November) 87-90) the maltodextrins of the present invention are expected, due to their production of a high amount of n-butyrate, to assists in the maintenance of colonic integrity.
The present RS product having a specific chain length distribution range of the retrograded structures is not only fermented more easily but produces, in absolute and relative terms, significantly higher amounts of n-butyrate than RS products derived from the conventional high amylose starches.
In order to obtain the RS structures (after pancreatine treatment) having more than 50% of the specified chain length of 10-35 AGU, a suitable starting material is needed. We have found that a low DE potato maltodextrin after enzymatic debranching and retrogradation forms more than 30% RS, more preferably more than 40% RS. The RS structures after pancreatine digestion consist for more than 50% of linear chains of 10-35 alpha-glucans. Other debranched/retrograded low DE maltodextrins (e.g. from tapioca, maize, wheat starch) can be used for this purpose too as can maltodextrins obtained from high amylose starches. Starches degraded by other methods (e.g. acid thinned) followed by debranching/retrogradation are also suited for this purpose.
Finally, the invention discloses the use of partially degraded retrograded starch composition to prevent or treat diseases of the colorectal digestive tract.
The invention is illustrated by the following examples.
Example 1 shows a method for obtaining the resistant starch of the present invention. A commercial potato maltodextrin was dissolved in water at an elevated temperature, after cooling and pH adjustment the maltodextrin was debranched with isoamylase. Following incubation the material was spray-dried. As shown in FIG. 1 the product had a chain length distribution wherein the majority of the pancreatine resistant chains was between DP 10 and DP 35. The resistant starch content was determined to be 56%.
This product is further indicated as IRP.
The experiment was repeated using tapioca maltodextrin and on a larger scale. Starting with 4200 kg tapioca maltodextrin about 3500 kg spray-dried product was obtained which contained 66% resistant starch had a DSC melting temperature of 112° C. and contained 65% material having a DP between 10 and 35.
Example 2 shows chemical and physical data for the resistant starch of the present invention IRP in comparison with Euresta-RS and Novelose™ (National Starch & Chemical Comp.). This example demonstrates that IRP has a significantly higher content of saccharide with DP 10-35 and much lower melting temperature of the RS residues than the two other products.
Example 3 describes in vitro fermentation tests with three different starch-based compositions;
IRP (obtained according to Example 1), Euresta and Novelose™ (National Starch & Chemical Comp.). The pH of the fermentation medium between the three RS products was found to be different after 4 h of fermentation. The reduction of pH was more pronounced for IRP than for Euresta and Novelose™ products. A slight difference persisted after 8 h of fermentation. After 24 h of fermentation pH values were identical (see FIG. 2). This indicates that IRP is better fermentable than the other products. SCFA and n-butyrate production were also followed. FIGS. 3 and 4 show the amounts of SCFA and of n-butyrate formed during the fermentation of the three samples. It appears that the IRP containing faeces gave the highest amount of both SCFA and n-butyrate.
Example 4 describes the addition of resistant starch (IRP) to a milk drink. It is demonstrated that after Ultra-High-Temperature treatment RS can still be determined in the milk. It can be concluded that RS can be applied in the normal food production processes without the need of adaptation of this process.
The invention is further illustrated by the following non-limiting examples.
EXAMPLE 1
Preparation of Debranched, Retrograded Low DE Maltodextrins
A) From Potato Maltodextrin
The reaction sequence for the production of the resistant starch from potato maltodextrin according to the present invention is given below.
Potato maltodextrin (MDx 01970 (DE 3) from Cerestar) was used as a starting material. ##STR1##
It is evident that one does not have to start from a dried product a wet product may directly be used in the same process. The enzymatic debranching conditions corresponded to the conditions given by the supplier for almost total debranching, about 59 units of enzyme activity/g starch were used.
The product of the indicated process was characterised as follows;
a resistant starch content of 56%,
a Mw of 11340,
a DSC melting peak temperature of the RS residue of 105° C.
the chain length distribution after pancreatine digestion of IRP is shown in FIG. 1.
The major part of the resistant starch product consisted of alpha-glucans with a DP between 10 and 35.
B) From Tapioca Maltodextrin
This example shows the large scale production of resistant starch from a low DE tapioca (cassava) maltodextrin (DE 2.5) is described. The debranching process was performed in a 20 m 3 double wall reactor. A freshly prepared maltodextrin was used after dilution to 25% d.s. The reaction scheme with more details is shown below: ##STR2##
The analysis of the 3.5 tons of spray-dried debranched maltodextrin gave the following results:
a resistant starch content of 66%
a Mw of 7230
a DSC melting temperature of the RS residue of 112° C.
a chain length distribution with 65% in the range between DP 10 and 35
EXAMPLE 2
Comparison of Composition and Properties of IRP with other RS Products Based on Retrograded High Amylose Starches
The following table describes the RS content, the chain length distribution and the DSC melting peak temperature of IRP, Novelose™ and Euresta RS.
______________________________________ RS- DSC*- DP content** T.sub.peak DP < 10*** 10-35*** DP > 35*** Sample (%) (° C.) (%) (%) (%)______________________________________IRP 56 105 7,0 58.7 34.3 Novelose 57 128 4,4 35,0 60,6 Euresta 36 141 5,1 26,1 68,8______________________________________ *DSC measurement: 20-30 mg of starch was brought into a stainlesssteel DSCpan and water was added to give a 20% (w/w) system. The closed pan was heated in a SETARAM DSC 111 from 20-160° C. at a rate of 3° C./min. The enthalpy change was continuously recorded and the characteristic transition temperatures were registered. **For RS determinations the following procedure was used: A 5% (w/w) suspension of the retrograded starch product is thoroughly homogenised in an acetate buffer solution. The acetate buffer is made by dissolving 8.2 g anhydrous sodium acetate in 250 ml of a saturated aqueou solution of benzoic acid, adding 4 ml of 1M calcium chloride and making u to 800 ml with distilled water before adjusting the pH to 5.2 with acetic acid, and finally making up to 1000 ml # with distilled water. 25 ml of the suspension are incubated with 1 ml pancreatic solution for 16 hours a 37° C. in a shaking water bath. The incubated suspension is next stirred into 119 ml of 95% ethanol, filtered, the filter cake washed twic with 80% ethanol and dried in an oven at 105° C. The RS content wa calculated as follows: #STR3## The pancreatic solution is made by stirring 2 g pancreatine with 12 ml distilled water for 10 min, centrifuging and using the supernatant as the pancreatic solution. ***The saccharide distribution was analysed as described in Carbohydr. Res. 215 (1991) 179-192 this method only measures saccharides below DP 85 The content of saccharides DP > was characterised by size exclusion chromatography and the relative amounts of the different fractions were calculated after normalisation.
EXAMPLE 3
In Vitro Fermentation of Partially Degraded Retrograded Starch (IRP) in Comparison with Novelose™ and Euresta
Experimental
A. Starting Material
IRP, (Cerestar) was prepared according to Example 1. The product was recovered by spray-drying. The product contained 56% RS and had a DSC melting peak temperature of 105° C.
Euresta-RS: retrograded starch was produced by cooling and storage of extrusion-cooked amylomaize starch (Amylomaize VII, American Maize Products Comp.). Amylomaize containing 50% water was extrusion-cooked at 100° C., followed by 4 days storage at 4° C., then dried and milled. The product contained 36% RS and had a DSC melting peak temperature of 141° C.
Novelose™: This starch is a modified amylomaize starch (National Starch and Chemical Corp.), enriched in RS. It contains 57% RS and had a DSC melting peak temperature of 128° C.
B. Method Used for Predigestion of RS Products
The purification of the RS for in vitro fermentation has been performed by extensive digestion of the starch with pancreatic α-amylase (Sigma, A-3176).
42.5 g IRP, 72.7 g Euresta or 30.7 g of Novelose were suspended in sterile phosphate buffer pH 6.9 (300 ml, 400 ml and 700 ml respectively) and brought into a dialysis tube and α-amylase (10 mg/g of sample) was added. The tubes were then plunged in 1 L water at 37° C. and kept overnight. The following day, the same amount of α-amylase activity was added again and a second digestion took place overnight. Samples were centrifuged (10 min, 3000 rpm) and washed several times. The sediment (RS) was freeze-dried.
C. Method Used for the in Vitro Fermentations
The method has been extensively described elsewhere (Barry et al., Estimation of fermentability of dietary fibre in vitro: a European interlaboratory study. Br. J. Nutr. (1995), 74, 303-322).
C1. General Schedule
All experiments were conducted in an in vitro batch system. Fermentations were performed in vials using inoculum made from fresh faeces collected from healthy young volunteers. The volunteers usually ingested a normal diet, presented no digestive disease and had not received antibiotics for at least three months. Fermentation variables were measured in vials in which fermentation was stopped at various times.
C2. Inoculum
Faeces from two non-methane producer volunteers were collected in an insulated bottle previously warmed for about 5 min with hot tap water (approximately 65° C.). To eliminate O 2 , the bottle was flushed for 5 min with CO 2 at a flow of 100 ml/s and faeces were then collected. When the insulated bottle was received at the laboratory, CO 2 was flushed inside. The weight of faeces was then determined. The inoculum was produced in the insulated bottle by adding five parts of a warmed (37° C.) nutritive buffer to one part of faeces (v/w). The nutritive medium was made from carbonate-phosphate buffer solution containing (g/l): NaHCO 3 9.240, Na 2 HPO 4 .12H 2 O 7.125, NaCl 0.470, KCl 0.450, Na 2 SO 4 0.100, CaCl 2 (anhydrous) 0.055, MgCl 2 (anhydrous) 0.047, urea 0.400, with added trace elements (10 ml of the following solution (mg/l) per liter of final solution: FeSO 4 .7H 2 O 3680, MnSO 4 .7H 2 O1900, ZnSO 4 .7H 2 O 440, CoCl 2 .6H 2 O 120, CuSO 4 .5H 2 O 98, Mo 7 (NH 4 ) 6 O 24 4H 2 O 17.4). Before use, and during preparation of the inoculum, continuous bubbling of CO 2 maintained anaerobiosis and ensured a constant pH. The slurry was mixed using a Stomacher (Laboratory Blended, Seward Medical, London) apparatus for 2 min and then filtered through six layers of surgical gauze. The inoculum was maintained in a water bath at 37° C. and continuously bubbled with CO 2 .
C3. Fermentation Experiments
Fermentation was conducted in duplicate using 50 ml polypropylene vials (Falcon, Biolock). Except for blanks (B), 100 mg (dry-matter basis) of well-homogenised experimental substrate was weighed into each vial and 10 ml inoculum added. Air was displaced by flow of O 2 -free N 2 . After the cap was screwed on, the vial was placed horizontally (time 0) in a shaking bath. Fermentation was then performed at 37° C. and the results studied at 0, 4, 8 and 24 h. Two blanks were used for each experimental time. At each experimental time, fermentation in corresponding vials was stopped by instantaneous freezing (dry ice).
C4. Sample Preparation
The pH was immediately measured and 10 ml distilled water added. Sample was then centrifuged 10 min at 3000 g. Two samples of 1 ml supernatant were taken for SCFA determinations. Samples were mixed with 100 μl HgCl 2 -H 3 PO 4 (1%/5%) solution. Samples for SCFA determination and pellets for starch determinations were kept at -20° C. until analysis.
SCFA were quantified by the gas chromatographic method as described by Jouany J. P. (Dosage des acides gras volatils (AGV) et des alcools dans les contenus digestifs, les jus d'ensilage, les cultures bacteriennes et les contenus des fermenteurs anaerobies. Sci. Alim., (1982), 2, 131-144).
Remaining starch was quantified by the method of Faisant et al. (Resistant starch determination adapted to products containing high resistant starch. Sci. Alim., (1995), 15, 83-89).
C5. Calculation of Short Chain Fatty Acid in Slurries
The production of P i of each SCFA was calculated as follows for each experimental time:
P.sub.i =(S.sub.i -S.sub.0)-(B.sub.i -B.sub.0),
where S i and S 0 are SCFA concentration values in vials containing substrates at time i and 0 respectively, and B i and B 0 are SCFA concentration values for blank at time i and 0 respectively.
For each experimental time, total SCFA production was calculated as the sum of individual production of acetic, propionic and n-butyric acid.
Results and Conclusion of in Vitro Fermentations
Kinetics of fermentation are determined by measuring pH and SCFA production, in duplicate. For all parameters and each product the same pattern of fermentation was observed upon comparing the duplicate measurements.
A) Evolution of pH
The pH of the fermentation medium between the three RS products differed after 4 h of fermentation. The reduction of pH was more pronounced for IRP than for Euresta and Novelose products. A slight difference persisted after 8 h of fermentation. After 24 h of fermentation pH values were identical (see FIG. 2).
B) SCFA and N-butyrate Production
FIGS. 3 and 4 show the amount of SCFA and of n-butyrate formed during the fermentation of the three samples. It appears that the IRP containing faeces gave the highest amount of both SCFA and n-butyrate. IRP gives rise to a faster production of n-butyrate according to FIG. 4 more than 10 mMol/L was produced within 4 hours. FIG. 3 shows that also the amount of the other SCFA is increased.
EXAMPLE 4
Preparation of UHT Milk Drinks with Resistant Starch
This example describes the use of the debranched retrograded maltodextrin of example 1 in a UHT vanilla milk drink. The standard recipe used for the preparation of milk drink is given below.
______________________________________Standard recipe: whole milk 1000 ml______________________________________ Satro mix* 12 g Sucrose 20 g Dextrose 20 g______________________________________ *Carrageenan, vanilla, colour
To this standard formula in one case 30 g/l and in the second case 60 g/l of IRP (see example 1) were added.
The ingredients were mixed and homogenised at 50 bar. The UHT treatment was done with plate heating at 137° C. for 5 seconds. The products were aseptically filled into 250 ml bottles.
After cooling to ambient temperature the products were characterised:
______________________________________Product RS-content (%) Taste and mouthfeel______________________________________Standard 0,0 very liquid, no off-taste, no sandiness + 30 g 1,0 somewhat more mouthfeel, more creamy, IRP/l no off-taste, no sandiness + 60 g 1,95 most mouthfeel, no sandiness IRP/l______________________________________
The results show that the major RS part survives even UHT-processing and is detectable in the final product using the method as mentioned in example 3. This is further confirmed by the DSC measurement (for method see example 2) of the residues obtained after pancreatine digestion (see FIG. 5). The sample prepared with 60 g/l IRP shows a strong endothermic transition with a peak temperature around 96° C. whilst the standard product does not show any significant transition in this temperature range. The use of IRP does not only increase the RS content but improves the organoleptic properties to a significant extent. Due to the small particle size there is no sandiness and the use of IRP causes the impression of a higher fat content. IRP can therefore be used with advantage in low (no) fat products in order to improve the sensorial properties.
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The present invention discloses that retrograded starch having more than 55% resistant starch with >50% chains of DP 10-35 gives rise to a significantly higher amount of n-butyrate production under conditions simulating the human colon. It is expected that such an increased n-butyrate production will diminish the development of colon diseases notably of colon cancer.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 11/762,745, filed Jun. 13, 2007, which is a continuation of U.S. application Ser. No. 10/302,804, filed Nov. 21, 2002, now U.S. Pat. No. 7,331,967, which claims benefit of priority from U.S. application Ser. No. 60/409,530, filed Sep. 9, 2002. This application is also related to application Ser. No. 11/762,743, filed Jun. 13, 2007. The disclosures of these applications are expressly incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] For certain medical procedures, minimally invasive surgery has replaced conventional surgery where the patient's body cavity is open to permit the surgeon's hands and instruments access to the cavity and internal organs. Minimally invasive procedures are typically less traumatic than conventional surgery, in part, because of the significant reduced incision size through which the medical instruments are inserted.
[0003] A video camera may be inserted into the patient in the area of the surgical site to view the procedure. It is, of course, important that the surgeon have some feedback either through a camera and fiber optic cable, or through real-time computerized tomography scan imagery. However, even with such visualization, the surgeon's tactile and position senses are physically removed from the operative site.
[0004] Some have proposed, therefore, the use of robots in surgery. Although current laparoscopy limits dexterity, and robotics restores dexterity, presently, existing systems, using manipulators both with and without haptic feedback, are generally too bulky and heavy for many minimally invasive procedures, or are too weak and imprecise for surgery.
SUMMARY OF THE INVENTION
[0005] In accordance with a first aspect of the present inventions, a medical system is provided. The medical system comprises a surgical instrument carrying a distal tool configured for performing a medical procedure on a patient. The medical system further comprises an adapter having a clam-shell configuration configured for removably receiving a proximal end of the surgical instrument. The medical system further comprises a drive unit (e.g., one having a motor array) configured for being coupled to the adapter to control the movement of the surgical instrument within at least one degree-of-freedom (e.g., an actuation of the distal tool). The drive unit may be coupled to the adapter via external cabling.
[0006] In one embodiment, the medical system further comprises a remote controller configured for directing the drive unit to control the movement of the surgical instrument within the degree(s)-of-freedom. The remote controller may have a user interface for receiving commands from a user. In this case, the movements made at the user interface may correspond to movements of the surgical instrument. The remote controller may be coupled to the drive unit via external cabling. In another embodiment, the medical system may further comprise a coupling mechanism through which the adapter is operably coupled to the drive unit. The coupling mechanism may comprise a carriage on which the surgical instrument is slidably mounted. In still another embodiment, the adapter has a driver element configured for being actuated by the drive unit, and the surgical instrument has a driven element configured for being actuated by the driver element to move the surgical instrument within the degree(s)-of-freedom. The driver element may be, e.g., a drive shaft, and the driven element may be, e.g., a wheel that mates with the drive shaft.
[0007] The clam-shell configuration of the adapter may be accomplished in any one of a variety of manners. For example, the adapter and the proximal end of the surgical instrument may have corresponding mechanisms that align with each other when the proximal end of the surgical instrument is received within the adapter. As another example, the adapter may have a base portion and a clam-shell that pivots relative to the base portion between a first position that encloses the proximal end of the surgical instrument within the adapter and a second position that allows the proximal end of the surgical instrument to be removed from the adapter. In this case, the adapter may have a catch mechanism configured for engaging the clam-shell in the first position, and a release mechanism configured for being actuated to disengage the clam-shell from the catch mechanism to place the clam-shell within the second position.
[0008] In accordance with a second aspect of the present inventions, a surgical instrument adapter is provided. The surgical instrument adapter comprises a base portion configured for receiving a proximal end of a surgical instrument, and a clam-shell that pivots relative to the base portion between a first position that encloses the proximal end of the surgical instrument within the base portion and a second position that allows the proximal end of the surgical instrument to be removed from the base portion. The surgical instrument adapter further comprises a driver element (e.g., a drive shaft) configured for actuating a driven element located at the proximal end of the surgical instrument to move the surgical instrument within at least one degree-of-freedom (e.g., an actuation of a distal tool carried by the medical instrument). In one embodiment, the driver element is configured for being actuating by a drive unit located external to the adapter. In another embodiment, the adapter has a mechanism configured for aligning the proximal end of the surgical instrument within the base portion. In still another embodiment, the adapter has a catch mechanism configured for engaging the clam-shell in the first position, and a release mechanism configured for being actuated to disengage the clam-shell from the catch mechanism to place the clam-shell in the second position.
BRIEF DESCRIPTION OF THE INVENTION
[0009] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred 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 the principles of the invention.
[0010] FIG. 1 is a perspective view of a telerobotic surgical system in accordance with the invention.
[0011] FIG. 2 is a close-up view of a slider and drive mechanism of the system of FIG. 1 .
[0012] FIG. 3 is close-up view of the slider mechanism of FIG. 2 .
[0013] FIG. 4 is a cross-sectional view of the slider mechanism taken along the line 4 - 4 of FIG. 3 with a support clamp attached to the slider.
[0014] FIG. 5 is a cross-sectional view of an angle drive mechanism taken along the line 5 - 5 of FIG. 4 .
[0015] FIG. 6 is a perspective view of the angle drive mechanism of FIG. 5 .
[0016] FIG. 7 is cross-sectional view of a linear drive mechanism taken along the line 7 - 7 of FIG. 4 .
[0017] FIG. 8 is a cross-sectional view of a block and tackle assembly taken along the line 8 - 8 of FIG. 4 .
[0018] FIG. 9A is a perspective view of the block and tackle assembly of FIG. 8 .
[0019] FIGS. 9B-9E illustrate a sequence of steps for operating the block and tackle assembly of FIG. 8 .
[0020] FIG. 10 is a cross-sectional view of a split drive shaft taken along the line 10 - 10 of FIG. 4 .
[0021] FIG. 11 is a cross-sectional view of a cable drive for an outer guide tube taken along the line 11 - 11 of FIG. 4 .
[0022] FIG. 12 is a fragmentary cross-sectional view of a drive shaft lockout mechanism taken along the line 12 - 12 of FIG. 10 .
[0023] FIG. 13 is a cross-sectional view of a lockout disk mechanism taken along the line 13 - 13 of FIG. 12 .
[0024] FIG. 14 is a cross-sectional view of an instrument insert and drive mechanism taken along the line 14 - 14 of FIG. 4 .
[0025] FIG. 15 is a perspective view of an insert drive cabling of FIG. 14 .
[0026] FIG. 16A is an exploded view of a partially disassembled slider unit.
[0027] FIG. 16B is an exploded view of the instrument adapter and clamshell ready to receive a tool insert.
[0028] FIG. 16C is an exploded view of the instrument adapter and clamshell with the tool insert mostly inserted into the guide shaft.
[0029] FIG. 16D is a cross-sectional view taken along the line 16 D- 16 D of FIG. 16C .
[0030] FIG. 16E is an exploded view of the instrument adapter and clamshell with the tool insert fully inserted into the guide shaft prior to closing the clamshell.
[0031] FIG. 17 is an exploded view of the underside of the instrument insert.
[0032] FIG. 18 is a detail view of a tensioning blade before engagement.
DETAILED DESCRIPTION OF THE INVENTION
[0033] A description of preferred embodiments of the invention follows.
[0034] The surgical robotic system of the present invention, illustrated generally at 10 in FIG. 1 , although preferably used to perform minimally invasive surgery, can also be used to perform other procedures as well, such as open or endoscopic surgical procedures. Certain details of the operation of the system 10 are described in U.S. application Ser. No. 10/014,143 filed Nov. 16, 2001, by Brock and Lee, the entire contents of which are incorporated herein by reference.
[0035] The surgical instrument system 10 includes two main components, a master station M and a slave station S. At the master station M, a surgeon 12 manipulates an input device 13 to direct the operation of a surgical instrument 14 of the slave station S to perform a medical procedure on a patient P lying on an operating table T. Although there are shown two surgical instruments 14 positioned on either side of an endoscope 15 and controlled by a respective input device 13 , the surgical system 10 can be used with a single surgical instrument. Moreover, although reference is made herein to a “surgical instrument,” it is contemplated that the principles of this invention also apply to other medical instruments, not necessarily for surgery, and including, but not limited to, such other implements as catheters, as well as diagnostic and therapeutic instruments and implements.
[0036] The surgeon is illustrated as seated in a comfortable chair 16 , and the forearms of the surgeon are typically resting upon an armrest 18 of a master assembly 20 associated with the master station M. A slave assembly 22 , also referred to as a drive unit, is associated with the slave station S, and is attached to a rail 24 of the table T with a clamp 26 , which can be released such that the drive unit can be optimally positioned. In some implementations, the master station M is positioned away from the slave station S, for example, in another room. The assemblies 20 and 22 are interconnected by a cabling 28 with a controller 30 , which typically has associated with it one or more displays 32 a for viewing the surgical site, and a display 32 b for monitoring the system performance of the system 10 , and a keyboard (not shown). A slider mechanism 34 , which carries the medical instrument 14 , is supported by a support arm 38 . The drive unit 22 is tethered to the slider mechanism 34 with a bundle of mechanical drive cables 36 . The support arm 38 is provided with a clamp 40 at one end that clamps to the slider mechanism, and another clamp 42 that clamps the support arm to the rail 24 . This mounting arrangement permits the instrument to remain fixed relative to the patient even if the table is repositioned.
[0037] The master station M may also be referred to as a user interface vis-a-vis the controller 30 . Associated with the controller 30 is a computer that operates in accordance with a computer algorithm, such that the computer translates the commands issued at the user interface into electronic signals transmitted to the drive unit 22 through the cabling 28 . These signals direct the operation of the drive unit 22 , which has motors to transform the electrical signals into mechanical movement of the cables 36 to produce the desired replicated motions of the surgical instrument 14 . In particular, the movement of the handle or hand assembly at the input device 13 is interpreted by the controller 30 to control the movement of the medical instrument 14 . The use of the cables 36 facilitates positioning of the drive unit 22 away from the operation region, for example, from the sterile field.
[0038] In the illustrated embodiment, the surgical instrument 14 includes an instrument insert 56 that supports, at its distal end, a tool 44 , and an adaptor 49 , also referred to as a holder, having a guide tube 46 that receives the instrument insert 56 ( FIG. 2 ). The surgical instrument 14 is coupled to a coupling mechanism, preferable a slider mechanism 34 . In this implementation, the surgical instrument 14 provides a number of independent motions, or degrees-of-freedom, to the tool 44 . The surgical guide 46 is basically a passive mechanical device and may be of relatively simple construction. It is a simple guide tube, curved at its distal end, through which the end effector or tool 44 is inserted. Motion of the guide tube results in a movement of the end effector or tool 44 . The guide tube may be designed in length, diameter, and curvature for particular surgical applications such as abdominal, cardiac, spinal, arthroscopic, sinus, neural, etc. The adaptor 49 provides a means for exchanging the instrument inserts and thus the instrument tools 44 , which may be, for example, forceps, scissors, needle drivers, electrocautery probes etc.
[0039] The endoscope 15 ( FIG. 1 ) includes a camera to remotely view the operation site. The camera may be mounted on the distal end of the instrument insert, or may be positioned away from the site to provide an additional perspective on the surgical operation. In certain situations, as shown, it may be desirable to provide the endoscope through an opening other than the one used by the surgical instrument 14 . The endoscope 15 is connected to the master station M with a cable 17 to allow the surgeon 12 to view the procedure with the monitors 32 a.
[0040] In this regard, three separate incisions are shown in the patient P, two side incisions for accommodating the two surgical instruments 14 and a central incision that accommodates the viewing endoscope. A drape 48 covering the patient is also shown with a single opening 50 through which the surgical guide 46 of the surgical instrument 14 extends into the patient P.
[0041] The cable bundles 36 may terminate at respective connection modules or drive unit couplers 52 , which attach to and may be removed from the drive unit 22 . Further details of the connection modules 52 can be found in the earlier co-pending applications No. PCT/US00/12553 and U.S. application Ser. No. 10/014,143 filed Nov. 16, 2001, the entire contents of which are incorporated herein by reference. Although one cable bundle is shown associated with each of the surgical instruments 14 , it is to be understood that more than one cable bundle can be used. Furthermore, although the drive unit 22 is shown located outside the sterile field, it may be draped with a sterile barrier so that it can be operated within the sterile field.
[0042] To set up the system 10 , the user connects the drive unit couplers 52 to the drive units 22 and places a sterile drape 54 over slider mechanisms 34 , cable bundle 36 and the drive unit couplers 52 . The user then clamps the support arm 38 to the slider mechanism 34 with the clamp 40 , which clamps a knob 51 through the drape 54 . The user attaches the sterile adaptor 49 to the underside of the slider mechanism 34 such that the drape 54 is positioned between the slider mechanism 34 and the adaptor 49 . The user then places a sterile tool insert 56 (see, e.g., FIG. 2 ) into the adaptor 49 such that the tool 44 extends past the terminal end of the guide tube 46 , and inserts the tool 44 of the surgical instrument 14 into the patient through the incision or opening.
[0043] Particular details of the system 10 and its operation are now described below with reference to FIGS. 2-18 .
[0044] Turning to FIG. 2 , the surgical instrument 14 is coupled to a carriage 58 of the slider mechanism 34 with the insert adaptor 49 through a sterile drape insert 62 . The sterile drape insert 62 is attached to the drape 54 in a manner to create a sterile field outside of the drape 54 . The drape 54 is typically made of a suitable flexible material, while the drape insert 62 is made of metal or a stiff plastic. The drive unit 22 includes a set of motors (seven total) with capstans 22 a that engage with respective drivers 52 a of the drive coupler 52 .
[0045] FIG. 2 also shows how the slider mechanism 34 is connected to the drive coupler 52 with the single bundle of cables 36 . In particular, the control wires or cables of the bundle 36 connect to the slider mechanism 34 at a single location 36 a that does not move. That is, although the cables within the bundle 36 weave through the slider mechanism 34 , and are coupled to respective driven capstans or drive pulleys, the point of attachment 36 a to the slider mechanism 34 is stationary. Hence, none of the cables interferes with the movement of the slider mechanism and thus the surgical instrument and vice versa. It is not necessary for the bundle 36 to be composed of cables. Any suitable flexible segment or tendon can be used in place of one or more of the cables in the bundle 36 .
[0046] Referring also to FIG. 3 , the carriage 58 includes a block and tackle assembly 64 that decouples the movements of the guide tube 46 and the tool 44 from the overall linear (B-B) and angular (A-A) movements of the slider mechanism 34 . Thus, as the surgeon 12 manipulates the input device 13 ( FIG. 1 ), the computer system 30 issues commands to the drive motor array 22 to produce a desired motion of the instrument 14 . In the illustrated embodiment, the surgical instrument 14 is able to move with seven degrees-of-freedom: the pivoting base motion A-A of the slider mechanism 34 , and thus the carriage 58 , the linear motion B-B of the carriage 58 , a rotary motion C-C of the outer guide tube 46 , a rotary motion D-D of the tool insert 56 , a pitch E-E motion and a yaw F-F motion of the tool 44 , and a grasping motion G-G of a pair of graspers 198 of the tool 44 . Each movement is driven from a respective motor capstan 22 a of the drive unit or array 22 through push/pull wires or cables of the bundle of cables 36 coupled to the slider mechanism 34 .
[0047] FIG. 3 also illustrates details of the clamp 40 which includes a handle 41 , a moveable jaw 43 , and a stationary jaw 45 , all mounted in a housing 47 . The handle 41 and the jaw 43 function as a cam action lock so that as someone pushes the handle 41 down towards the housing 47 , the moveable jaw 47 and the stationary jaw 45 lock onto the knob 51 at the top of the slider mechanism 34 to secure the slider mechanism 34 to the support arm 38 .
[0048] Turning now to FIGS. 4-6 , there is shown the carriage 58 supported by a pair of rails 72 attached at one end to an end block 74 , and at the other end to a rotatable base 76 . The rotatable base 76 is connected to an axle 78 which in turn is mounted to an end cap 80 and a housing 90 with a pair of bearings 83 . The end cap 80 is suspended from the housing 90 by a set of bars 92 . An angle drive mechanism 70 includes a pair of gear reduction pulleys 84 and 86 connected to another axle 88 mounted with a pair of bearings 89 to the housing 90 . The drive mechanism 70 also includes a driven pulley 94 secured to the axle 78 , and coupled to the gear reduction pulley 86 with a cable 96 . As shown in FIG. 5 , the cable 96 has two ends 97 that attach to a cable tensioning block 99 mounted in the driven pulley 94 . Thus, as a set screw 99 a is turned, thereby moving the block 99 , the appropriate tension is applied to the cable 96 . A pair of cable segments 102 and 104 of the bundle of cables 36 are guided through a pair of guide pulleys 98 and 100 and attach to the gear reduction pulley 84 with respective cable anchors 106 and 108 . The other ends of the cables 102 and 104 are coupled to respective motor capstans 22 a of the drive unit 22 through the drive coupler 52 .
[0049] Accordingly, as a motor of the drive unit 22 applies tension to either of the cables 102 or 104 , a rotary motion is imparted to the pulley 84 and hence the pulley 86 about the longitudinal axis 110 of the axle 88 . The rotary motion of the pulley 86 consequently imparts a rotary motion through the cable 96 to the driven pulley 94 about the longitudinal axis 112 of the axle 78 . The driven pulley 94 in turn imparts a rotary motion of the rotatable base 76 and thus the carriage 58 back and forth in the direction of the double arrow A-A. Referring to FIG. 7 , there is shown a linear drive mechanism 120 that moves the carriage 58 back and forth along the rails 72 in the direction B-B. The linear drive mechanism 120 includes a pair of cable segments 122 and 124 attached to the carriage with respective anchors 126 and 128 . The cable 122 is guided about a guide pulley 130 , while the cable 124 is guided through a guide pulley 132 , the guide pulley 130 , and about an idler pulley 134 mounted in the end block 74 . The other ends of the cables 122 and 124 are attached to a motor of the drive unit 22 through the coupler 52 . Accordingly, as tension is applied to the cable 122 , the carriage moves from left to right, while tension applied to the cable 124 moves the carriage 58 from right to left.
[0050] Turning now to FIG. 8 , there is shown details of the block and tackle assembly 64 . The block and tackle assembly 64 includes a coupling system 200 for each of the degrees-of-freedom C-C, D-D, E-E, F-F, and G-G ( FIG. 3 ) that are decoupled from the linear B-B and rotary movements A-A of the carriage 58 . Although the coupling systems 200 are layered or stacked, the operation of the systems is best illustrated with reference to the single coupling system shown in FIG. 8 and further illustrated in FIGS. 9A-9E . The coupling system 200 includes two stationary pulleys 202 and 204 fixed to the slider 58 , and two additional pulleys 206 and 208 mounted in respective sliders 206 a and 208 a that are able to slide relative to the carriage 58 along tracks 210 . The pulleys 202 , 204 , 206 , and 208 and the sliders 206 a and 206 b are made of plastic or metal, and the tracks 210 are formed of plastic or Teflon™ . or any other suitable material that minimizes friction between the tracks 210 and the sliders 206 a and 206 b . A pair of cable segments 220 and 222 are attached at a first location 214 and a second location 216 , respectively, to a pair of anchors 218 on the end block 74 . The first cable segment 220 wraps around the sliding pulleys 206 and the stationary pulley 202 , and the second cable segment 222 wraps around the other sliding pulley 208 and the other stationary pulley 204 . The two segments 220 and 222 are fed through a pair of guide pulleys 224 and 226 and are coupled to a respective motor of the array 22 through the coupler 52 . The sliding pulleys 206 and 208 are also connected with another cable 230 to a driven capstan 232 that imparts one of the degrees-of-freedom of movement C-C, D-D, E-E, F-F, and G-G ( FIG. 3 ) to the surgical instrument.
[0051] When the system 10 is in operation, as the carriage 58 moves back and forth with the linear motion B-B ( FIG. 9E ), the cable segments 220 and 222 roll freely over the pulleys 202 , 204 , 206 , and 208 without rotating the driven capstan 232 . That is, the linear movement of the carriage 58 does not influence, and is therefore decoupled from, the degrees-of-freedom of movement C-C, D-D, E-E, F-F, and G-G.
[0052] If, however, the capstan 22 a is rotated to pull on the segment 220 or segment 222 , the distance between one of the stationary pulleys 202 or 204 and the corresponding sliding pulley 206 or 208 decreases, while the distance between the other fixed and sliding pulleys increases, resulting in a rotary motion of the driven capstan 232 . By way of example, as shown in FIG. 9C , if the capstan 22 a is rotated counterclockwise in the direction R to pull on the cable segment 222 from an initial position shown in FIG. 9B , the length of the cable 222 around the pulleys to the anchor 218 is shortened, causing the sliding pulley 208 to move towards the stationary pulley 204 . Since the cable 230 is of a fixed length, it pulls the other sliding pulley 206 away from the stationary pulley 202 , and rotates the driven capstan 232 counterclockwise with a rotary movement R′. No linear movement is imparted to the carriage 58 .
[0053] Similarly, as shown in FIG. 9D , if the capstan 22 a is rotated clockwise in the direction R″ to pull on the cable segment 220 , the sliding pulley 206 moves towards the stationary pulley 202 , while the sliding pulley 208 moves away the stationary pulley 204 , which imparts a clockwise rotary motion R′″ to the driven capstan 232 .
[0054] Note, as mentioned earlier, the movements B-B, C-C, D-D, E-E, F-F, and G-G do not influence and are therefore decoupled from the rotary movement A-A of the carriage 58 .
[0055] Referring now to FIG. 10 , a drive mechanism 300 used to drive one of the degrees-of-freedom E-E, F-F, or G-G of the tool 44 is shown. The drive mechanism 300 includes a lower drive shaft 302 mounted in the adapter 49 . The lower drive shaft 302 is coupled to an upper drive shaft 304 of the coupling system 200 through a rotatable coupler 306 that is mounted in the drape insert 62 . The lower drive shaft 302 is also coupled to a respective drive wheel 308 of the instrument insert 56 . The upper drive shaft 304 is provided with a set screw 310 that when rotated pushes against a set screw extension 312 which clamps the cable 230 in the driven capstan 232 mounted about the upper drive shaft 304 . As such, as the driven capstan 232 rotates, as discussed with reference to FIGS. 9A-9E , the rotary motion of the capstan 232 imparts a rotary motion of the drive wheel 308 through drive shaft 304 , coupler 306 , and the lower drive shaft 302 .
[0056] As mentioned above, the insert can be made of a stiff plastic. Similarly, the coupler 306 can be made from two plastic pieces 306 a and 306 b ( FIG. 10 ) connected together through a hole in the base 63 of the insert 62 . The lower piece 306 b is provided with a bearing 307 that allows the coupler 306 to rotate relative to the base 63 . Either or both of the insert 62 and the coupler 306 can be made of metal rather than plastic.
[0057] Rotary motion of the guide tube 46 (C-C) and the insert 56 (D-D) are imparted though somewhat different mechanisms. In particular, referring to FIG. 11 , a drive mechanism 330 used to drive the rotary motion of the outer guide tube 46 includes a lower drive shaft 332 mounted in the adapter 49 . The lower drive shaft 332 is coupled to a respective upper drive shaft 304 through the coupler 306 , similar to that described above for the lower drive shaft 302 . However, unlike the previously described drive mechanisms 300 , the lower drive shaft 332 is provided with a right angle cable drive 333 . The cable drive 333 includes a pulley 334 , and a pair of idler pulleys 336 mounted to the adapter 49 with a shaft 338 and positioned at 90.degree. from the pulley 334 . A cable 340 is wrapped around the pulley 334 , guided through the idler pulleys 336 , and attached to an outer tube drive pulley 342 clamped to the outer guide tube 46 with a clamp screw 344 . Hence rotary motion of the upper drive shaft 304 about an axis 346 ( FIG. 4 ) results in a rotary motion (C-C) about an axis aligned at a 90.degree. angle from the axis 346 .
[0058] Referring back to FIG. 4 , a similar drive mechanism 350 is used to rotate the shaft 353 of the insert 56 in the direction D-D ( FIG. 3 ). For the drive mechanism 350 , a drive cable 352 is coupled to tool shaft drive pulley 354 . The drive pulley 354 in turn is coupled to the shaft 353 . As such, as the upper drive shaft 304 rotates about an axis 360 , a consequent rotary motion is imparted to the shaft 353 to produce the rotary motion D-D.
[0059] Referring to FIGS. 12 and 13 , when the adaptor 49 is clamped to the drape insert 62 , a blade like tip 414 of the adaptor 49 fits in a slot 416 of the coupling 306 , so that rotation of the coupling 306 rotates the lower drive shaft 302 or 332 . When removing the adaptor 49 , a lockout mechanism 400 assures that the blade 414 remains in the same position to fit into the slot 416 when the adaptor 49 is reattached to the insert 62 . That is, the lockout mechanism 400 prevents rotation of the lower drive shafts 302 or 332 when the insert adapter 49 and the drape insert 62 are not clamped together. The lower drive shaft 302 or 332 is provided with a washer 404 positioned beneath a disk 406 . A clip 408 secures the washer 404 , disk 406 and hence the lower drive shaft 302 in place. When the adapter 49 and the insert 62 are clamped together, a protrusion 410 on a flexure 412 , attached to the surface the adaptor 49 with a screw 413 , is pushed down by the drape insert 62 to release a catch tab 411 on the flexure 412 from engagement with the disk 406 , thereby allowing the drive shaft to rotate. That is, the catch tab 411 is pushed out of a respective perforation or hole 406 a of the disk 406 . Meanwhile coupling between the lower drive shaft 302 and the coupler 306 occurs as the blade 414 engages with the slot 416 of the coupling 306 .
[0060] Additional details of the arrangement of the outer tube drive pulley 342 and the shaft drive pulley 354 in relation to the insert 56 are shown in FIG. 14 . The outer tube drive pulley 342 is positioned between an end section 500 and a mid section 502 of the adapter 49 . As mentioned above the outer tube drive pulley 342 is clamped to the outer tube 46 , which is mounted in the end section 500 and the mid section 502 with respective bearings 504 and 506 . Hence rotation of the drive pulley 342 causes a consequent rotation of the guide tube 46 with the degree-of-freedom of movement C-C ( FIG. 3 ). The shaft drive pulley 354 is positioned adjacent to the mid section 502 and mounted about the outer tube 46 with a bearing 508 so that it can rotate relative to the outer tube 46 . A retainer clip 510 holds the drive shaft pulley 354 in place. The shaft pulley 354 is also provided with a valve 356 , made from, for example, silicone. The shaft 353 is inserted through a flexible flap 356 a with a hole in it and into the guide tube 46 . Prior to the insertion of the shaft 353 into the guide tube 46 , the resiliency of the valve 356 and in particular the flap 356 a causes the hole in the flap to close off, hence, creating a seal between the guide tube 46 and the remainder of the adaptor 49 to prevent gas from escaping from the operating site through the guide tube 46 . Similarly, when the shaft 353 is in place, the flap 356 a forms a seal about the shaft 353 to prevent the escape of gas. A drive arm 512 of the insert 56 engages with a slot 514 of the pulley 354 to couple the shaft 353 with the pulley 354 so that the shaft 353 rotates with the pulley 354 with the degree-of-freedom of movement D-D ( FIG. 3 ).
[0061] Referring now to FIG. 15 , there is illustrated how the drive wheels 308 of the insert 56 engage with respective lower drive shafts 302 . In particular, a face 520 of each drive wheel 308 mates with an opposing face 522 of the respective lower drive shaft 302 .
[0062] Referring now to FIG. 16A , as well as FIGS. 2 and 4 , details of the attachment of the adaptor 49 to the slider mechanism 34 are shown, as well as the insert 56 prior to insertion of the shaft 353 into the guide tube 46 . The drape 54 is placed between the adaptor 49 and the bottom of the carriage 58 , and then a lip 600 of the adaptor 49 is placed into a corresponding lip 602 of the carriage assembly 58 , with the drape 54 pinched between the two lips. The adaptor 49 is then rotated up so that it engages with the carriage 58 through the drape insert 62 . A clamp 604 is then snapped in place to secure the adaptor 49 to the slider mechanism 34 .
[0063] Referring to FIG. 16B , there is shown the insert 56 prior to insertion into the adaptor 49 . The adaptor 49 includes alignment holes 610 for the corresponding nubs 612 of the insert 56 . The adaptor 49 also includes a clamshell 614 attached to a base portion 616 with a pivot joint 618 . The clamshell 614 is provided with a pair of pins 617 that engage with respective keyholes 620 of a catchplate 622 . A clamshell release handle 624 is springloaded with a spring 625 ( FIG. 10 ) to allow a user to release the clamshell 614 from the catchplate 622 by pushing on the handle 624 .
[0064] Referring also to FIG. 16C , after the shaft 353 is inserted into the guide tube 46 , the drive arm 512 mates with the receiving slot 514 to couple the shaft 353 to the shaft drive pulley 354 . In addition, a release pin 626 extending from the base portion 616 pushes against a flexure 628 to unlock the shaft 353 ( FIG. 16B ). Referring also to FIG. 17 , the flexure 628 has a hole 629 in which a tab 631 is positioned before insertion. The tab 631 is attached to the shaft 353 such that as the flexure 628 is pushed away from the tab 631 the shaft 353 is free to rotate.
[0065] Referring also to FIG. 16D , as the insert 56 is rotated in place, the nubs 612 align and fit into the alignment holes 610 while the face 520 of the drive wheels 308 mate with the face 522 of the lower drive shafts 302 . The clamshell 614 is provided with a spring 630 ( FIGS. 10 and 16C ) that pushes against the bottom of the insert 56 when the clamshell 614 is snapped into the locked position so that the insert 56 abuts against the adaptor 49 with an applied force. FIG. 16E illustrates the instrument insert 56 fully inserted, but with the clamshell 614 still open.
[0066] The adaptor 49 , such as depicted in FIG. 16A , is readily attachable and detachable with the coupling mechanism such as the block and tackle assembly 64 . This provides a more adaptable surgical system useable with a greater number of types of surgical procedures. For example, one of the primary differences from adaptor-to-adaptor may be the radius of curvature of the distal curved end of the guide tube 46 . Also, the length of the curved section of the guide tube may be varied, or the combination of curvature and length can to taken into account in selecting different adaptors. Moreover, the diameter of the tube could be different depending upon size and diameter of the instrument insert. Furthermore, instead of providing a curvature at the distal end of the guide tube, there can be a straight bend at the distal end. Either a curvature, bend, or other deflection of the distal end of the guide tube provides the desired off-set of the distal end so that, upon rotary motion C-C of the guide tube, there is motion of the tool out of the plane defined by the pivoting base motion A-A.
[0067] For some surgical procedure, as mentioned above, it may be desirable to substitute different types of adaptors. For example, if a particular procedure requires work in both a focused small area, as well as in a broader extending area of the patient, it is desirable to use different types of adaptors. The different adaptors might have different lengths, diameters, curvatures, or combinations thereof.
[0068] Details of the individual drive mechanisms of the insert 56 that provide the degrees of freedom of movement E-E, F-F, and G-G ( FIG. 3 ) are illustrated in FIGS. 17 and 18 , as well as FIG. 15 . For each degree-of-freedom, a pair of cables 700 and 702 extends through the shaft 353 and is coupled at the terminal ends of the cables to the tool 44 . The other ends of the cables 700 and 702 are attached to respective drive wheels 308 with cable anchors 704 and 706 .
[0069] Illustrated in FIG. 18 is a tensioning mechanism 710 that is in a non-tensioned position when the insert 56 is not in use. The tensioning mechanism includes a tensioning handle 712 ( FIG. 17 ) provided with a tab 729 on its underside that engages with a slot 731 on the bottom of a blade 714 , and a pair of outer lips 730 that engage with a pair of undercuts 732 on the bottom of the insert housing 750 .
[0070] Prior to inserting the insert 56 into the adaptor 49 , a user turns the handle 712 about 90.degree. until the tension blade 714 rests against a stop pin 716 , while a pair of spring-arm catches 734 snap up and latch the blade 714 in place. When this occurs, the blade 714 spreads the cables 700 and 702 apart such that they are pushed against a pair of cable guide posts 718 to pretension the cables 700 and 702 . This pretension position of the blade 714 is shown in FIGS. 14 and 15 . The handle 712 is provided with a pair of slots 730 a that match up with the undercuts 732 so that when the handle has been turned approximately 90.degree. the handle can be removed from the insert 56 . Note also that the housing 750 has a cutout 752 that provides a clearance while the insert 56 is being inserted into the adaptor 49 .
[0071] The blade 714 can be made of plastic and is provided with smooth surfaces 720 made of, for example, stainless steel, so that the cables 700 and 702 are able to glide over the blade 714 with minimal friction. Similarly, the guide posts 718 are also provided with smooth surfaces 722 that minimize friction between the posts 718 and the cables 700 and 702 .
[0072] While this invention has been particularly shown and described with references to preferred 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. For example, although the slider mechanism is described in the context of a coupling mechanism, other embodiments in which the cable bundle is attached at its distal end at a stationary location are also considered within the scope of the present invention.
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A medical system and surgical instrument adapter are provided. The medical system comprises a surgical instrument carrying a distal tool configured for performing a medical procedure on a patient, an adapter having a clam-shell configuration configured for removably receiving a proximal end of the surgical instrument, and a drive unit configured for being coupled to the adapter to control the movement of the surgical instrument within at least one degree-of-freedom. The surgical instrument adapter may comprise a base portion configured for receiving a proximal end of the surgical instrument, and a clam-shell that pivots relative to the base portion between a first position that encloses the proximal end of the surgical instrument within the base portion and a second position that allows the proximal end of the surgical instrument to be removed from the base portion.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device incorporated in the exhaust system of an automotive or similar internal combustion engine for purifying exhaust gases emanating from the engine and, more particularly, to an exhaust purifying device of the type using a metallic core having a honeycomb structure and coated with a catalyst.
2. Description of the Related Art
An exhaust purifying device or so-called catalytic converter has customarily been incorporated in the exhaust system of an automotive or similar internal combustion engine, e.g., an exhaust pipe or a muffler. Provided with a catalyst, the catalytic converter promotes the oxidation of carbon monoxide, hydrocarbons and other toxic components contained in exhaust gases emanating from the engine. One of conventional catalytic converters has a cylindrical casing attached to predetermined part of, for example, a muffler, and a metallic honeycomb core received in the casing and coated with a catalyst. The honeycomb core is made up of a corrugated sheet of metal and a flat sheet of metal which are rolled up together in a spiral configuration. Such a core is inserted into the casing and then soldered together with the casing. As a result, the corrugated sheet and flat sheet are bonded together to prevent the honeycomb structure from being deformed while, at the same time, the outer periphery of the core is bonded to the inner periphery of the casing to prevent the core from moving in the casing. However, the problem with this kind of catalytic converter is that the soldering operation is complicated and time-consuming. This, coupled with the fact that the solder itself is expensive, increases the cost of the catalytic converter.
To eliminate the above problem particular to soldering, Japanese Patent Laid-Open Publication No. 94015/1988, for example, discloses an exhaust purifying device in which a core is received in a cylindrical casing, but the former is not soldered to the latter. Specifically, retaining members are each affixed to one end of the casing in such a manner as to extend through the center of the opening of the casing. The retaining members prevent the core from slipping out of the casing and prevent the radially central portion of the core from protruding from the casing in an auger-like configuration. On the other hand, U.K. Patent 1452982 teaches an exhaust purifying device having similar support members affixed to opposite ends of a casing.
However, the conventional retaining members or support members affixed to the cylindrical casing as stated above simply restrict the core in the axial direction of the casing, i.e., they cannot cope with the movement of the core in the circumferential direction. As a result, when an automotive vehicle with such an exhaust purifying device is in travel, the core is apt to move in the circumferential direction within the casing due to the stream and heat of engine exhaust, vibration of the vehicle body and so forth. Specifically, it is likely that the core rotates within the casing while the corrugated sheet and flat sheet shift and rub against each other within the core. This would cause the catalyst to come off the core while cracking or breaking the core itself, degrading the expected function of the device.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an exhaust purifying device capable not only of restricting a core in the axial direction in a casing and preventing it from being deformed, but also of preventing the core from rotating in the casing while preventing members forming the cells of the core from shifting relative to each other.
An exhaust purifying device for reducing toxic components contained in an exhaust emanating from an internal combustion engine of the present invention comprises a casing to be connected at both ends thereof to an exhaust system extending from the internal combustion engine, and a core received in the casing and provided with a honeycomb structure constituted by a corrugated sheet and a flat sheet which are rolled up together in a spiral configuration. A pair of retaining members are received in axially opposite ends of the casing for preventing the core from moving in the axial direction and circumferential direction relative to the casing. The retaining members each radially traverses the associated end of the casing and includes a biting portion slightly biting into the associated end of the casing.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the present invention will become more apparent from the consideration of the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view showing an exhaust purifying device embodying the present invention;
FIG. 2 is a perspective view showing a core included in the embodiment specifically;
FIG. 3A is a section view showing the embodiment in a condition wherein retaining members are attached to a casing;
FIG. 3B is a view similar to FIG. 3A, showing a condition wherein the retaining members are attached to the casing; and
FIGS. 4 and 5 each shows an alternative embodiment of the exhaust purifying device in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawings, an exhaust purifying device or catalytic converter embodying the present invention is shown and generally designated by the reference numeral 10. As shown, the catalytic converter 10 has a hollow cylindrical casing 12 and a honeycomb core 14 made of metal and received in the casing 12. The casing 12 is welded or otherwise affixed to, for example, a muffler or an exhaust pipe of an automobile to form part of an exhaust passage. A catalyst is applied to the honeycomb core 14. In the illustrative embodiment, the core 14 is not soldered or otherwise affixed to the casing 12. Generally cruciform retaining members 16 are positioned at opposite ends of the casing 12, and each bites into adjoining end of the core 14.
Specifically, the casing 12, like the muffler or the exhaust pipe, is formed of a steel sheet having a predetermined strength great enough to resist the high-temperature and high-pressure engine exhaust. The steel sheet may be implemented as a stainless steel sheet which is 1 millimeter to 3 millimeters thick. The casing 12 is provided with a cross-section matching that of the muffler or the exhaust pipe, e.g., a circular, elliptical or partly curved rectangular cross-section. In the embodiment, let the casing 12 be assumed to have a circular cross-section for the sake of illustration. Also, in the embodiment, the casing 12 has a length m1 which is about 10 millimeters longer than the length m2 of the honeycomb core 14. Each end of the core 14 stands back from the adjoining end of the casing 12 by about 5 millimeters.
As shown in FIG. 2, the honeycomb core 14 is constituted by a corrugated sheet or vent sheet 18 and a flat sheet or partition sheet 20 laid one above the other. The corrugated sheet 18 and flat sheet 20 are rolled up together in a spiral configuration to form exhaust passageways extending in the axial direction of the core 14. The exhaust passageways are separated both in the radial direction and in the circumferential direction, thereby forming a honeycomb structure. Received in the casing 12, the core 14 has an outside diameter L1 slightly smaller than or substantially equal to the inside diameter L2 (see FIG. 1) of the casing 12. Specifically, the vent sheet 18 is formed by corrugating an elongate thin sheet metal and coating both surfaces of the corrugated sheet with a catalyst, e.g., platinum, palladium or rhodium. For example, the vent sheet 18 is implemented by a thin stainless steel sheet which is highly resistive to the high-temperature and high-pressure engine exhaust and, in addition, flexible enough to be rolled. In the illustrative embodiment, the vent sheet 18 has a thickness t3 of about 50 microns to about 100 microns. The vent sheet 18 is rolled up with the intermediary of the partition sheet 20 in a spiral to divide the exhaust passage of the muffler or that of the exhaust pipe into a plurality of passageways in the circumferential direction of the core 14. The passageways each extends along the axis of the core 14. This configuration allows the engine exhaust to contact the core 14 over a broad area. The partition sheet 20, like the vent sheet 18, is constituted by an elongate thin stainless steel sheet whose opposite surfaces are coated with palladium, rhodium or similar catalyst. The partition sheet 20 also has a thickness t4 of about 50 microns to 100 microns. At the beginning of rolling, the partition sheet 20 is arranged along the bottoms of the corrugations of the vent sheet 18 to form a core portion. Then, the sheet 20 is sequentially rolled in a spiral along the bottoms of the corrugations of the sheet 18 to define the cells of the honeycomb in the radial direction. As a result, the sheet 20 closes the upper and lower axially extending channels of the sheet 18 to guarantee a sufficient area over which the engine exhaust flowing through the core 14 contacts the catalysts. Finally, the sheet 20 forms the outer periphery of the core 16 enclosing the peaks of the corrugations of the sheet 18.
Referring again to FIG. 1, the cruciform retaining members 16 located at opposite ends of the casing 12 are each constituted by two elongate flat pieces, or bars, 16a and 16b. Each of the bars 16a and 16b is slightly bent at both ends thereof in opposite directions and in a shape complementary to the inner periphery of the casing 12. Specifically, the bars 16a and 16b are implemented as stainless steel sheets which are about 1 millimeter thick and about 5.5 millimeters wide. While such stainless steel sheets originally have a length greater than the inside diameter L2 of the casing 12, they are bent at both ends thereof to be received in the casing 12. The bars 16a and 16b are each formed with a slit widthwise at substantially the intermediate between opposite ends and are joined together perpendicularly to each by means of such slits. In the illustrative embodiment, the bars 16a and 16b are each formed with a saw-toothed portion 30 at one side edge thereof. As shown in FIG. 3A, the saw-toothed portion 30 has teeth whose height h ranges from about 0.5 millimeter to about 1.0 millimeters. The teeth are caused to bite into the core 14 by the following specific, but not limitative, procedure. One of the retaining members 16 is inserted into the casing 12 and positioned such that the end of the member 16 void of the teeth is flush with the end of the casing 12. The bent ends of this retaining member 16 are welded or otherwise connected to the inner periphery of the casing 12. Subsequently, the honeycomb core 14 is inserted into the casing 12 from the other end opposite to the retaining member 16 connected to the casing 12. After the core 14 has abutted against the retaining member 16 at one end thereof, the other retaining member 16 is forced into the casing 12 until the end thereof void of the teeth becomes flush with the other end of the casing 12. Then, this retaining member 16 is affixed to the casing 12 by welding or similar technology. Alternatively, the two retaining members 16 may be forced into opposite ends of the casing 12 in such a manner as to slightly press the adjoining ends of the core 14, in which case the members 16 will be affixed to the casing 12 after a predetermined load has been detected. In any case, the retaining members 16 are positioned in the casing 12 such that their teeth slightly bite into opposite ends of the core 14.
The casing 12 of the catalytic converter 10 having the above structure is welded or otherwise connected at both ends thereof to the intermediate portion of, for example, the exhaust pipe or the muffler of an automobile. The high-temperature exhaust from an engine mounted on the automobile flows into the core 14 via one end of the casing 12. Then, the exhaust is distributed to the number of passageways or cells of the honeycomb core 14 defined by the vent sheet 18 and partition sheet 20. At this instant, the catalyst applied to the two sheets 18 and 20 promote the oxidation of the exhaust, i.e., causes it to recombust. As a result, the exhaust coming out of the core 16 contains a minimum of carbon monoxide, hydrocarbons and other toxic components. Finally, the purified engine exhaust is emitted to the atmosphere.
While the automobile with the catalytic converter 10 is in travel, the honeycomb core 14 implemented by thin stainless steel sheets is apt to move in the axial direction due to, for example, the vibration of the vehicle body. However, the retaining members 16 affixed to the casing 12 and bitten into both ends of the core 14 prevent the retaining members 16 from moving in the above-mentioned direction. Since the retaining members 16 have a cruciform shape and retain the radially central portions of the core 14, they prevent the core 14 from being deformed in an auger-like configuration. Further, as the vehicle body vibrates and the engine exhaust flows through the honeycomb passageways under a high pressure, the core 14 is also apt to rotate relative to the casing 12 while the vent sheet 18 and partition sheet 20 are apt to shift relative to each other. The illustrative embodiment minimizes such an occurrence since the retaining members 16 press the core 14 with a predetermined force from both sides and since the saw-toothed portions 30 of the members 16 which are perpendicular to each other bite into the two sheets 18 and 20 of the core 14 in the radial direction. This prevents the catalysts from coming off the sheets 18 and 20 and protects the core 17 from cracks or similar damage, thereby enhancing the service life of the catalytic converter 10. In addition, the saw-toothed portions 30 of the retaining members 16 do not crush the ends of the core 14 more than necessary and bite into the core 14 only at points, i.e., not on lines. Hence, the teeth 30 allow the ends of the core 14 to adequately adapt thereto, thereby more surely eliminating the undesirable movement of the core 14.
FIG. 4 shows an alternative embodiment of the present invention. In FIG. 4, the same or similar constituents as or to the constituents of the previous embodiment are designated by the same reference numerals, and a redundant description will be avoided for simplicity. As shown, a catalytic converter, generally 10A, has retaining members 40 each being implemented as a single elongate member or bar which is bent at both ends thereof. The retaining members 40 are welded or otherwise affixed to opposite ends of the casing 12 perpendicularly to each other. Each retaining member 40 is formed with a saw-toothed portion 42 which bites into the adjoining end of the core 14, as in the previous embodiment.
FIG. 5 shows another alternative embodiment of the present invention. In FIG. 5, the same or similar constituents as or to the constituents of the previous embodiments are designated by the same reference numerals, and a redundant description will be avoided for simplicity. As shown, a catalytic converter, generally 10B, is essentially similar to the catalytic converter 10 of FIG. 1 except for the means for affixing the retaining members to the casing. Specifically, the casing 12 of the catalytic converter 10B is formed with four notches at equally spaced locations along the circumference at each end thereof. Retaining members 60 differ from the retaining members 16, FIG. 1, in that they are not bent at opposite ends thereof. The retaining members 60 are each received in the notches 50 of one end of the casing 12 and fixed in place by caulking.
In summary, in accordance with the present invention, an exhaust purifying device has retaining members provided with saw-toothed portions and affixed to both ends of a cylindrical casing. The saw-toothed portions bite into both ends of a honeycomb core disposed between the retaining members. As a result, the core is preventing from rotating relative to the casing while members constituting the core are prevented from shifting relative to each other. This prevents catalysts from coming off the members of the core and protects the core from damage despite that the core is not soldered or otherwise fixed to the casing. The device of the invention is, therefore, easy to fabricate, inexpensive, and has a long life.
While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention. For example, the saw-toothed portions 30 or 42 are only illustrative and may be provided with any other suitable configuration. Of course, the present invention is applicable not only to an automobile but also to any other motor vehicle, e.g., a motorcycle.
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An exhaust purifying device for reducing toxic components contained in an exhaust emanating from an internal combustion engine. The device has a casing connected at both ends thereof to an exhaust system extending from the engine, and a core received in the casing and provided with a honeycomb structure constituted by a corrugated sheet and a flat sheet which are rolled up together in a spiral configuration. A pair of retaining members are received in axially opposite ends of the casing for preventing the core from moving in the axial direction and circumferential direction relative to the casing. Each of the retaining members radially traverses the associated end of the casing and includes a biting portion slightly biting into the associated end of the core.
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[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 11/398,161, filed Apr. 4, 2006, and claims the priority of provisional patent application Nos. 60/708,206, filed Aug. 15, 2005, and 60/668,022, filed Apr. 4, 2005, the entire contents of each of which is incorporated herein by reference.
GOVERNMENT RIGHTS
[0002] This invention was made with Government support under Grant No. N00014-04-1-0654, awarded by the Office of Naval Research. The Government has certain rights in this invention.
[0003] Throughout this application various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which this invention pertains.
TECHNICAL FIELD OF THE INVENTION
[0004] The invention disclosed herein relates to compositions and methods for modulating the blood coagulation cascade, accelerating bone generation, and assisting in wound healing and body repair. Both the materials selected for the hemostatic composition and the method for regulating hemostasis provide novel means for predictable control over blood coagulation, allowing for both accelerating and slowing or stopping blood flow.
BACKGROUND OF THE INVENTION
[0005] U.S. Pat. No. 4,822,349 issued to Hursey, et. al. describes reduction of blood flow by application of a dehydrated zeolite material to the site of blood flow. In this method, a particular calcium rich zeolite formulation of the class Linde Type 5A has been utilized as an external application to a traumatically wounded individual to induce hemostasis through dehydration of the wounded area and induction of a blood clot formation (Breck, D W et al., J Am. Chem. Soc. 78, 23 (1956) 5963.). A major disadvantage to this product has been the excessive heat generated locally at the injured site as a consequence of the large enthalpy of hydration associated with the material currently marketed under the trade name, QuikClot™ and distributed Z-medica corporation of Newington, Conn. USA. There remains a need for modifications and improvements that optimize the enthalpy of hydration upon rehydration of the dehydration zeolite.
[0006] Bioactive glasses (BGs) with SiO 2 —CaO—P 2 O 6 —MO (M=Na, Mg, etc.) compositions were invented by Hench in 1971 (L. L. Hench et al., J. Biomed. Mater. Res. 1971, 2:117) and have been widely studied and used in clinical applications for bone and dental repair due to their chemical bonding with both soft and hard tissue through an apatite-like layer. The apatite-like layer promotes the adhesion of bioactive glass to tissues and avoids the formation of an intervening fibrous layer. This has been shown to decreases the failure possibilities of prostheses and influence the deposition rate of secondary bone and tissue growth. In vivo implantation studies demonstrate that these compositions produce no local or systemic toxicity, are biocompatible, and do not result in an inflammatory response. The SiO 2 —CaO—P 2 O 5 —MO BG system has been synthesized by the melting-quenching method (Hench et al., 1971, supra) or by the sol-gel method (P. Sepulveda et al., J. Biomed. Mater. Res. 2002, 59:340; P. Saravanapavan and I. I. Hench, J. Biomed. Mater. Res. 2001, 54:608). Compared with the traditional melting-quenching method, sol-gel techniques were developed in the past decade to produce the same material at a lower working temperature. Sol-gel techniques also allow a greater degree of functionalization to be incorporated into the bioactive glass material to increase the rate of apatite-like layer growth as well as afford a wider range of bioactivity.
SUMMARY OF THE INVENTION
[0007] The invention provides a homogeneous composition comprising a hemostatically effective amount of a charged oxide, wherein the composition has an isoelectric point, as measured in a calcium chloride solution, below 7.3 or above 7.4. Typically, the charged oxide is selected from the group consisting of silaceous oxides, titanium oxides, aluminum oxides, calcium oxides, zinc oxides, nickel oxides and iron oxides. In some embodiments, the composition further comprises a second oxide selected from the group consisting of calcium oxide, sodium oxide, magnesium oxide, zinc oxide, phosphorus oxide and alumina. In a typical embodiment of the invention, the charged oxide is silaceous oxide, the second oxide comprises calcium oxide and the ratio, by molar ratio, of silaceous oxide to calcium oxide is 0.25 to 15. Optionally, the composition further comprises phosphorous oxide. Unlike conventional silaceous oxide compositions, the composition of the invention can be free of sodium oxide.
[0008] The charged oxide can be porous or non-porous. In some embodiments, the charged oxide comprises glass beads that are from about 10 nm to about 100 microns in diameter, typically from about 3 to about 10 microns in diameter. In some embodiments, the oxide is a layered clay such as the aluminosilicate Kaolin. In some embodiments, the charged oxide is porous, having pores of 2-100 nm diameter, typically 100-200 μm diameter. The greater the porosity, the greater the surface area. The internal surface can be between 1 and 1500 square meters per gram as determined by BET N 2 adsorption. While non-porous bioactive glass typically has a surface area around 20-30 square meters per gram, mesoporous bioactive glass is distinct because its surface area is greater than 200 square meters per gram. In a typical embodiment, the surface area is between 300 and 1000 square meters per gram.
[0009] Additional components that can be included in a composition of the invention include a zeolite and/or an inorganic salt. Examples of an inorganic salt include, but are not limited to, a divalent ion selected from the group consisting of zinc, copper, magnesium, calcium and nickel, as well as the following: CaO, CaCl 2 , AgNO 3 , Ca(NO 3 ) 2 , Mg(NO 3 ) 2 , Zn(NO 3 ) 2 , NH 4 NO 3 , AgCl, Ag 2 O, zinc acetate, magnesium acetate, calcium citrate, zinc citrate, magnesium citrate, magnesium chloride, magnesium bromide, zinc chloride, zinc bromide, calcium bromide, calcium acetate and calcium phosphate.
[0010] In some embodiments, the charged oxide is hydrated to between 0.1% and 25%, typically between 0.5% and 5% w/w. The composition of the invention can be prepared as a sol-gel. In some embodiments, the composition further comprises an ammonium phosphate buffer.
[0011] The invention additionally provides a method of modulating hemostasis comprising contacting blood with a composition described herein. The modulating can comprise decreasing blood coagulation time, for which purpose the composition has an isoelectric point below 7.3. Examples of materials with an isoelectric point below 7.3 include, but are not limited to, silaceous oxides, titanium oxides and aluminosilicates. Alternatively, the modulating comprises increasing blood coagulation time and the composition has an isoelectric point above 7.4. Examples of materials with an isoelectric point above 7.4 include, but are not limited to, Al 2 O 3 and related aluminum oxides, calcium oxides, zinc oxides, nickel oxides, and magnetite and related iron oxides.
[0012] Also provided is a method of preparing a hemostatic composition. The method comprises: co-assembling a bioactive glass sol with a structure-directing amount of a triblock copolymer of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) to form a gel; and calcining the gel so produced at a temperature sufficiently high to remove the block copolymer and form mesopores; wherein the bioactive glass has an isoelectric point below the pH of blood. Similarly, the invention provides a method of preparing a passivated surface composition for minimizing coagulation upon contact of blood with the surface. The method comprises co-assembling a bioactive glass sol with a structure-directing amount of a triblock copolymer of poly(ethylene oxide)-poly (propylene oxide)-poly(ethylene oxide) to form a gel; and calcining the gel produced in step (a) at a temperature sufficiently high (typically 300-700° C.) to remove the block copolymer, form mesopores and create a highly hydroxylated surface, wherein the bioactive glass has an isoelectric point above the pH of blood.
[0013] In addition, the invention provides a method of preparing a hemostatic composition. This method comprises passing a carrier gas through a solution comprising a bioactive glass sol to produce droplets; and spraying the droplets down a furnace. Examples of a carrier gas include, but are not limited to, air, nitrogen, oxygen, or natural gas. In some embodiments, such as for preparation of mesoporous materials, the solution further comprises a block copolymer.
[0014] In another embodiment, the invention provides a method of preparing a hemostatic composition of micropores. The method comprises cooling a solution comprising silicic acid and calcium salts to below 0° C. to form a gel; and freeze-drying the gel to form micropores. Typically, the cooling step comprises cooling the solution to −70° C. to −200° C. In some embodiments, the solution further comprises a phosphorous oxide, typically in the form of a phosphate group. In another embodiment, the solution further comprises chitosan. The method can further comprise calcining the gel at 300 to 900° C. In a typical embodiment, the cooling comprises direction freezing. In some embodiments, the micropores produced by the method are 1 to 200 microns in diameter.
[0015] The invention further provides a method of modulating hemostasis comprising contacting blood with a composition prepared by one of the methods described herein. In addition, the invention provides a medical device that has been coated with a composition of the invention, such as a composition having an isoelectric point above the pH of blood.
[0016] Also provided is a method of promoting the formation of tissue comprising contacting the composition of the invention with a hydroxyapatite precursor solution. The tissue can comprise, for example, artificial bone, artificial skin, or a compound thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a plot of both clot detection time, R, (filled shapes) and rate of coagulation, α, (un-filled shapes) vs. BG Si:Ca. Data represents the mean of four trials. ▪ Porous BG;● Non-porous BG; ▾ Spherical BG; +No HA.
[0018] FIG. 2 is a Thrombelastograph® plot of bioactive hemostatic agents. Inner Thromboelastograph plot on both plots is sheep blood without a HA added.
[0019] FIG. 3 is a Thrombelastograph® plot of bioactive glass, QuikClot™, and sheep's blood alone.
[0020] FIG. 4 is a thermogravimetric analysis and differential scanning calorimetry of the dehydration of porous and non-porous bioactive glass. 90 J/g (Non-porous Bioactive glass) and 450 J/g (Porous Bioactive glass).
[0021] FIG. 5 is a Thrombelastograph® plot of mesoporous bioactive glass with varying SiO2:CaO ratios. BG 80 has a molar ratio of SiO2:CaO of 80:16 BG 60 has a molar ratio of SiO2:CaO of 60:16.
[0022] FIG. 6 is a Thrombelastograph® plot of non-porous bioactive glass with varying SiO2:CaO ratios. BG NP 80 has a molar ratio of SiO2:CaO of 80:16. BG NP 70 has a molar ratio of SiO2:CaO of 70:16. BG NP 60 has a molar ratio of SiO2:CaO of 60:16.
[0023] FIG. 7 is a thermogravimetric analysis and differential scanning calorimetry of the dehydration process for a hydrated mesoporous bioactive glass and a non-porous bioactive glass.
[0024] FIG. 8 is a compilation of the heat of hydration and hydration capacity of bioactive glass. BG 80 has a molar ratio of SiO2:CaO of 80:16. BG 60 has a molar ratio of SiO2:CaO of 60:16.
[0025] FIG. 9A shows a Thromboelastograph® plot of the hemostatic activity MBGM- 80 induced coagulation vs. blood w/o MBGM- 80 .
[0026] FIG. 9B shows a plot of both clot detection time, R, (filled shapes) and rate of coagulation, α, (un-filled shapes) vs. amount of mesoporous bioactive microspheres. Data represents the mean of four trials. ▪ MBGM- 60 , ● MBGM- 80 , ▴ MBGM- 60 Non-porous, ▾ MBGM- 80 Non-porous, +Sheep Blood w/o MBGM.
[0027] FIG. 10 shows BET adsorption-desorption isotherm of bioactive glass.
[0028] FIG. 11 shows pore size distribution of mesoporous bioactive glass.
[0029] FIG. 12 shows BET surface area and pore diameter calculations.
[0030] FIG. 13 shows wide angle x-ray diffraction of bioactive glass substrates pre- and post-immersion in simulated body fluids for 1 hour.
[0031] FIG. 14 is a Thrombelastograph® plot of oxides with an isoelectric point below the pH of blood.
[0032] FIG. 15 is a Thrombelastograph® plot of oxides with a isoelectric point above the pH of blood.
[0033] FIG. 16 shows R (min), onset of clot detection, versus the metal oxide's isoelectric point for low-surface area metal oxides.
[0034] FIG. 17 shows α (°), rate of coagulation, versus the metal oxide's isoelectric point for low-surface area metal oxides.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The invention is based on the discovery that oxide materials can be prepared to modulate hemostasis on the basis of surface change. This modulation enables the synthesis of materials that are: pro-coagulants; or, alternatively other materials that are anticoagulants. The latter are of importance with respect to the oxide coatings that form on metal medical implant devices. The methods of preparing oxide compositions of the invention avoid problems associated with longer setting times and also produce materials having better performance characteristics. The methods of the invention produce materials that offer superior compositional and structural homogeneity and higher surface area, which provide more effective materials. For example, one embodiment of the invention provides a rapid-setting, mesoporous, bioactive glass cement that exhibits excellent plasticity, superior bioactivity and is mechanically robust. In addition to modulation of hemostasis, the oxide compositions of the invention can be used for growth and repair of bone and other tissues as well as in drug delivery.
[0036] In one embodiment of the invention, high surface area mesoporous bioactive glass has been prepared by a sol-gel template directed assembly. This material has the ability to conform and adhere to wounded tissue to promote blood clot formation. This specific material has a distinct morphological advantage over previous bioactive glass materials in that it can conform and adhere to any wound cavity geometry. When mixed with an ammonium phosphate buffer solution, a bioactive glass cement can be formulated that has a predictable set time and accelerates the deposition of new apatite layers when in contact with biological fluids. Mesoporous bioactive glass (MBG) cements are malleable before setting and retain their shape and mechanical strength without crumbling after setting. Furthermore, mesoporous bioactive glass has demonstrated a high osteoconductive property. This material can be formulated in a variety of compositions for applications as a rapid acting hemostatic agent, template for the growth of artificial bone, and the generation of tissue. Bioactive glass can be formulated for a variety of distinct wound healing scenarios and can elicit a predictable wound healing response, for both controlling the flow of blood as well as controlling the rate of apatite deposition, as a function of agents chemical composition and Si to Ca ratio.
[0037] In addition to the synthesis of mesoporous bioactive glass, this invention provides a method by which materials can be selected based on their isoelectric point to induce a predictable hemostatic response. Under physiological conditions, the isoelectric point of an oxide will determine both the sign and magnitude of the initial surface charge density upon exposure to biological fluids. Oxides have been identified that will induce coagulation upon exposure to blood. Oxides have also been identified that will prevent or slow down the coagulation response of blood in contact with the surface of the oxide. A strategy to produce both rapid acting hemostatic agents and passivated medical device surfaces is described based on the selection criteria.
[0000] Definitions
[0038] All scientific and technical terms used in this application have meanings commonly used in the art unless otherwise specified. As used in this application, the following words or phrases have the meanings specified.
[0039] As used herein, a “hemostatically effective amount” means an amount sufficient to initiate detectable blood clotting (R) within 2 minutes, and/or achieve a rate of clotting (α) of 50° or greater, and/or achieve a clot strength (MA) of ≧50, as determined by Thromboelastograph® measurements. Assays for determining hemostatic effectiveness are known in the art, and described in the Examples below.
[0040] As used herein, a “thromboelastograph® assay refers to measurements typically taken using about 5-30 mg of material mixed with 340 microliters of citrate stabilized blood. Calcium ions are re-supplied to the citrate stabilized blood prior to measurements to replace the calcium ions chelated by citrate.
[0041] As used herein, “isoelectric point” refers to the pH at which the zeta-potential equals zero in an aqueous electrolyte such as 2 mM CaCl 2 . The zeta potential is the surface charge density of a metal oxide in aqueous suspension, measured as a function of pH by the electrophoretic method using the Smoluchowski equation (Cocera, M. et al., Langmuir 1999, 15, 2230-2233). Unless specifically indicated otherwise, the zeta potential of the metal oxide is measured in a CaCl 2 electrolyte that mimics the Ca 2+ concentration in blood.
[0042] As used herein, “homogeneous” means an absence of phase separation (e.g., separation of a silicate phase and a phosphate phase); the materials are not phase segregated when examined by energy-dispersive x-ray analysis (EDX) using scanning electron microscopy (SEM) with a resolution limit of 0.5 microns. A composition is homogeneous if it consists of a uniform distribution or dispersion of components.
[0043] As used herein, a “bioactive glass sol” means a colloidal suspension containing silica precursors and calcium salts that can be gelled to form bioactive glass solid, wherein the solvent can be water, ethanol or other substance that can dissolve silica precursors and calcium species.
[0044] As used herein, “a” or “an” means at least one, unless clearly indicated otherwise.
[0000] Bioactive Glass (BG)
[0045] For the sol-gel-derived BGs to exhibit in vitro bioactive behavior, it has been shown that both the chemical composition and textural properties (pore size and volume) are important. Melt-derived glasses show a direct dependence on composition with bioactivity. Increasing the specific surface area and pore volume of BGs will greatly accelerate the kinetic deposition process of hydroapatite and therefore enhance the bone-forming bioactivity of BGs. Several strategies have been developed to obtain high specific surface area materials and engineer pore structure of the BGs, including using soluble inorganic salt, colloidal spheres or block copolymers as pore-forming agents. The high surface area mesoporous bioactive glass described herein has a unique morphology with advantages over these methods including higher surface area and ease of functionalization of the final material. This functionalization includes, but is not limited to, the surface immobilization and the controlled release of biologically relevant molecules. Molecules such as phospholipids, fibrin, collagen, clotting zymogens, heat shock proteins, antibacterial peptides, and silver, magnesium, calcium, sodium, zinc, chloride, and phosphate ions can be controllably released to effect an optimal bio-response.
[0046] The porous bioactive glass material can be described by the general formula (SiO 2 —CaO—P 2 O 5 —MO (M=Na, Mg, etc.). BET analysis has shown that the bioactive glass of the invention has a surface area far greater than the 5 square meters per gram (m 2 /g) observed in prior art materials, and typically in the range of more than 100 m 2 /g, often more than 200 m 2 /g. In one embodiment, the bioactive glass of the invention has a surface area of at least about 300 m 2 /g. Surface areas of 500-1000 m 2 /g can be attained. The surface area is influenced by the polymer used in synthesis of the bioactive glass. A surface area of about 300 m 2 /g has been attained with bioactive glass prepared from P123, while low molecular weight polymers, such as L43, can produce much higher surface area (in the range of 900 m 2 /g). The high surface area provides for optimal pore volume.
[0000] Hemostatic Activity of Bioactive Glass
[0047] Disclosed herein is a new and specific application of bioactive glass related to rapid acting hemostatic agents for the treatment of traumatic injuries. The traumatic wound healing scenario is distinct from prior medical applications for bioactive glass-like materials. The term “bioactive glass” has been loosely applied to many companies of calcium oxide, silicon dioxide, phosphorous oxide and other metal oxides, the combination of which is able to promote the growth of bone and tissue.
[0048] The invention described in U.S. provisional patent application No. 60/668,022, filed Apr. 4, 2005, provides a calcium loaded zeolite linde type A that is ion exchanged with aqueous solutions of alkali, alkaline earth, and transition metal cations to specific ion formulations. This ion exchanged zeolite can be mixed with neutral inorganic salts like calcium chloride, aluminum sulfate, and silver nitrate and dehydrated to remove water. The dehydrated inorganic materials are sealed in mylar foil bags to prevent rehydration until required during medical application. At the time of medical application, the mylar bag can be opened and the inorganic contents poured into the traumatically injured site.
[0049] The present invention provides the bioactive glass in a gel, liquid, cement, paste or powder form, which allows for greater ease of use and better conformation to a desired area to be treated. By providing the material in gel (or cement) form, for example, it can be applied to a greater variety of surfaces, increasing its availability for use in numerous contexts, including application to medical devices and drug delivery.
[0050] Porous bioactive glass materials have been designed to treat traumatically injured tissue by inducing hemostasis through contact activation and release of coagulation co-factors. In addition, the compositions of the present invention provide a uniform pore size that further optimizes its use for regulation of hemostasis.
[0051] The hemostatic activity of bioactive glass is dependent on the material's chemical composition. For the range of chemically distinct bioactive glass agents studied (Si:Ca:P atomic _ratio 60:34:4 to 90:6:4), the onset time for contact-activated coagulation, rate of coagulation of post-initiation, and ultimate clot strength was found to be dependent on the material's Si:Ca ratio, porosity, and heat of hydration. The onset time for contact-activated coagulation was found to decrease in an increasing Si:Ca ratio. The rate of coagulation post-initiation was found to increase with an increasing Si:Ca ratio. Porous bioactive glass was found to have a greater procoagulation tendency than non-porous bioactive glass.
[0000] Bone-generating Activity of Bioactive Glass
[0052] The bone-generating activity of bioactive glass is dependent on the material's chemical composition. For the range of chemically distinct bioactive glass agents studied, (Si:Ca:P atomic _ratio 60:36:4 to 90:6:4) the deposition rate of hydroxyapatite deposition in biological fluids is related to the material's Si:Ca ratio and particle size and shape. The rate of deposition of hydroxyapatite was observed to be faster for bioactive glass samples with a lower Si:Ca ratio (e.g., BG60:36:4 faster than BG80:16:4).
[0053] The high osteoconductive properties of this unique formulation of bioactive glass is a result of the presence of a large number of surface hydroxyl groups (Si—OH) that provide nucleation sites for apatite-like layer growth. The sol-gel technique developed in our laboratory allows us to optimize these nucleation sites for a tailored bio-response, and ultimately an improved generation of hydroxyapatite.
[0000] The Isoelectric Point Material Property as a Predictor of Hemostatic Activity
[0054] The isoelectric point of a material is a critical material parameter that can be utilized to select oxides that can either promote or prevent the induction of hemostasis. Rapid acting hemostatic agents and passivated medical devices are applications intended for this material. The present inventors have discovered that the oxide's initial surface charge, driven by the isoelectric point of the material relative to the pH of the immersing biological medium, is the key factor in controlling hemostatic efficacy of the composition.
[0055] The onset time for contact-activated coagulation, rate of coagulation post-initiation, and ultimate clot strength are found to be dependent on the initial surface charge density of the metal oxide when exposed to blood, which is related to the oxide's acid-base nature and is quantitatively described by its isoelectric point. We found, that for polar metal-oxide substrates, the time to initiate contact-activated coagulation increases with the increase in the metal oxide's isoelectric point.
[0056] Blood is usually the first fluid an implanted foreign body encounters, and thus the thrombotic complications which arise from metallic implants (chronic inflammatory response), and inorganic-based estracorporeal circulating devices parts, arterial stents, and catheters is related to the chemistry that occurs during the initial exposure of blood to a foreign oxide surface. Although the activating inorganic surface will become contaminated with biological products over time (e.g. massive attack complex, fibrin 12 ), the initial surface charge density of a metal oxide surface will affect the selective adhesion of oppositely charged molecules and biological media (e.g. cells and larger proteins) immediately upon contact with blood. We observed that both the sign and magnitude of the metal oxide's surface-charge density affects blood coagulation metrics, including the onset time, rate of clot formation, and viscoelastic strength of contact-activated blood clots, and that an oxide's isoelectric point can be used to predict its in vitro hemostatic activity.
[0057] Negatively-charged surfaces are known to initiate the intrinsic pathway of the blood coagulation cascade, a network of feedback-dependent reactions that when activated results in a blood clot. The activation of this process by a foreign body is referred to as contact activation of coagulation. The same network of coagulation reactions also can be activated via the entrinsic pathway, which occurs when a breach in the endothelium allows the exposure of platelets to tissue factor bearing cells.
[0058] Because of the electronegativity difference between oxygen atoms and the metallic atoms they are covalently bonded to, metal oxides are inherently polar surfaces. Their surface chemistry is all the more complicated due to the presence of “dangling” terminal hydroxyl groups on unsaturated metal sites and related defect sites. The surface charge of metal oxides is known to be pH dependent and is thought to result from either the amphoteric dissociation of surface MOH groups or the adsorption of metal hydroxo complexes derived from the hydrolysis product of material dissolved from the metal oxide. There exists a unique pH for each oxide above which the material is negatively charged and below which the material is positively charged. The pH at which the sum total of negative and positive surface charges equals zero, Σ(z-n) M z (OH) n z-n =0, is called the isoelectric point.
[0059] We have observed a variable contact-activated coagulation response from metal oxides with distinct isoelectric points, all of which are inherently polar substrates, and which requires that we refine our understanding of the traditional definition of hemocompatibility based on surface energetics. We have found that acidic oxides are prothrombotic while basic oxide are antithrombotic. The relative difference between the metal-oxide's isoelectric point and the pH of blood determines the initial surface-charge density of the substrate when exposed to blood. This material parameter has been shown to affect the onset time for coagulation, rate of coagulation post-initiation, and ultimate clot strength.
[0000] Thromboelastograph Assay
[0060] Thromboelastograph®. The in vitro hemostatic activity of metal-oxide hemostatic agents was evaluated as previously described using a THromboelastograph®, a clinical instrument that monitors the change in viscoelasticity of blood as a function of time. Briefly, 340 μL of 4% v/v citrate-stabilized sheep blood (Quad Five of Ryegate, Mont.) was introduced into the sample cup of a Thromboelastograph®, Haemoscope model 5000, along with 20 μL of 0.2M CaCl 2 (aq) and 5-20 mg of a tested metal-oxide in a powder morphology. The 20 μL of 0.2 M CaCl 2 (aq) was added to the stabilized blood to replenish the Ca 2+ ions chelated by citrate, which was added to prevent coagulation of stored blood. Blood was stored at 8° C. prior to use.
[0061] The thromboelastograph® sample cup is rotated ±5° about a vertical torsion wire suspended in the middle of the cup. As the hardening blood clot tugs on the torsion wire, the change in viscoelectric clot strength is monitored as a function of time. The time until the bimodal symmetric viscoelasticity curve's amplitude is 2 mm is referred to as R (minutes), and represents the initial detection of clot formation. The angle between the tangent to the curve and the horizontal is referred to as α (°), and is related to the rate of coagulation. The maximum amplitude of the curves is referred to as MA (mm) and represents the maximum clot strength. Thromboelastograph® clotting parameters reported represented the mean of four reproducible trials. A summary of the hemostatic properties of metal-oxides with variable isoelectric points is described in Table 1.
TABLE 1 Summary of Metal-Oxide Contact-Activated Coagulation Low-surface-area High-surface-area Clotting Metric metal oxides metal oxides Onset of Coagulation onset time Coagulation onset coagulation; increased or of equal time for positively R (min) value compared to blood charged surface Initially alone for positively similar to blood Positively charged surface, and alone Charged Metal slowest for the most Oxide positive surface Initially Coagulation onset time Coagulation onset Negatively reduced for negatively time reduced for Charged Metal charged surfaces, and negatively charged Oxide fastest for most nega- surfaces tive substrate Rate of Positively-charged Positively-charged coagulation surfaces decelerate surfaces decelerate post-initiation; the rate of coagulation the rate of α (°) coagulation Initially Positively Charged Metal Oxide Initially Negatively-charged Negatively-charged Negatively surfaces accelerate surfaces accelerate Charged Metal the rate of coagulation the rate of coagula- Oxide tion in the presence of sufficient Ca2+ ions Isoelectric Point Isoelectric Point Clotting Metric Below the pH of Blood Above the pH of Blood Onset of Coagulation onset time Coagulation onset time coagulation; reduced for negatively increased or of equal R (min) charged surfaces, and value compared to fastest for most blood alone for negative substrate positively charged surface, and slowest for the most positive surface Rate of Negatively-charged Positively-charged coagulation surfaces accelerate surfaces decelerate post-initiation; the rate of coagulation the rate of coagulation α (°) Ultimate clot Most negative oxide Induced blood clots strength (MA) resulted in strongest are less than or blood clots and least equal in strength to negative oxide resulted naturally formed in weakest blood clot blood clots
Methods
[0062] The invention provides a method of producing a composition for modulating hemostasis, and also a method of modulating hemostasis comprising contacting blood with a composition of the invention. Compositions that modulate hemostasis can be prepared by the methods described in the Examples below, including aerosol synthesis and use of sol-gel chemistry. Sol-gel chemistry can be used to produce bioactive glass. By spraying the sol-gel solution down a hot furnace (e.g., 400° C.), spherical bioactive glass particles are produced. These bioactive glass particles can be as small as 10-50 nm in diameter, or smaller, or as large as about 100 μm or larger. In one embodiment, the particles are 50-200 nm in diameter.
[0063] Typically, the method of producing a composition of the invention involves starting from a bioglass sol, wherein the solvent is ethanol (or another solvent that can dissolve precursors and has a low boiling point). A block copolymer can be used as an additive to provide a pore-forming agent.
[0064] In some embodiments, such as the freezing method, the ideal solvent is water rather than ethanol because the melting point of ethanol is very low. The difference in solvent typically calls for some difference in the method. For example, most PEO—PPO—PEO block copolymers cannot dissolve in water. Second, chitosan can be incorporated into the system because it doesn't dissolve in the ethanol, and chitosan plays an important role in modulating blood coagulation. In addition, the silica and phosphorous precursors are different from those in an ethanol-based method and phosphorous oxide is not required in the starting sol, as would be the typical case when starting with a bioglass sol.
[0065] In some embodiments, the method of modulating hemostasis comprises decreasing blood coagulation time. In one embodiment, the time to initiate detectable coagulation (R), as measured by thromboelastograph®, is less than 2 minutes, and can be less than 1.8 minutes. In another embodiment, the rate of coagulation (α), is measured by thromboelastograph®, is more than 50°. Coagulation rates of more than 55°, and of more than 65° have been achieved. In a further embodiment, the coagulation results in blood coagulation time. Increased coagulation time is desirable, for example, when clotting poses a health risk to the subject.
[0000] Applications of the Invention
[0066] Oxides with an isoelectric point below the pH of blood can be formulated for action to induce blood clot formation faster than blood would naturally do in the absence of an oxide-contact activator. The materials can be applied both externally and internally as agents to induce hemostasis and reduce the flow of blood in a particular area of the body.
[0067] Oxides with an isoelectric point above the pH of blood can be formulated to induce blood clot formation slower than blood would naturally do in the absence of an oxide-contact activator, and therefore would be suitable as passivated surfaces for medical devices. Thus, the invention provides a medical device and methods of coating a medical device with a composition of the invention. Coatings can be prepared from a composition in powder form or using sol-gel chemistry, using conventional methods known in the art. In one embodiment, the coating reduces coagulation of blood in contact with the device. The medical devices include, but are not limited to, arterial and verial stents, catheters, shunts, and any medical machinery that will contact blood during invasive medical procedures.
[0068] Oxides with an isoelectric poin above the pH of blood can be formulated for devices that require a positively charged surface to interface with biological tissue and fluids.
[0069] Oxides with an isoelectric point below the pH of blood can be formulated for devices that require a negatively charged surface to interface with biological tissue and fluids.
[0070] When mixed with an ammonium phosphate buffer solution, a bioactive glass cement can be prepared with a controllable set time, Bioactive glass, and particularly, bioactive glass cement, can be prepared with a flexible morphology that allows for conformation and adhesion to any wound geometry. The bioactive glass cement can be molded in a variety of shapes that retain their mechanical integrity post-setting. The bioactive glass cements can accelerate the deposition of an apatite layer compared to the bioactive glass agent alone.
[0071] Mesoporous bioactive glass can be formulated as a rapid acting hemostatic agent. This material can predictably warm injured tissue to promote wound healing.
[0072] Mesoporous bioactive glass can be formulated to promote the formation of artificial bone. This same material can be used to generate tissue including, but not limited to, artificial skin and structural elements such as fibrin and collagen.
[0073] The internal porous architecture can be loaded with biologically relevant molecules and cofactors for controlled release during wound healing and body repair. These biologically relevant molecules and cofactors include, but are not limited to, phospholipids, blood coagulation factors, fibrin, collagen, blood clotting symogens, silver ions, magnesium ions, and calcium ions.
[0074] The internal porous architecture can be loaded with antibacterial peptides and silver ions for a controlled release of antibacterial agents.
[0075] Non-porous bioactive glass can be formulated as a rapid acting hemostatic agent. This material can predictably warm injured tissue to promote wound healing.
[0076] Non-porous bioactive glass can be formulated to promote the formulation of artificial bone. This same material can be used to generate tissue including, but not limited tot, artificial skin and structural elements such as fibrin and collagen.
[0077] The hemostatic activity of bioactive glass can be controlled and optimized for a variety of wound healing scenarios by manipulating the ratio of Si to Ca in the chemical composition of both porous and non-porous bioactive glass. The bone-generating activity of bioactive glass can be controlled and optimized for a variety of wound healing scenarios by manipulating the ratio of Si to Ca in the chemical composition of both porous and non-porous bioactive glass.
EXAMPLES
[0078] The following examples are presented to illustrate the present invention and to assist one of ordinary skill in making and using the same. The examples are not intended in any way to otherwise limit the scope of the invention.
Example 1
Hemostatic Activity of Bioactive Glass
[0079] The time clot unit detection, R, decreases for increasing Si:Ca ratios in BG ( FIG. 1, 2 ). R is reduced by a factor of 2 when the Si:Ca ratio is doubled over the range studied.
[0080] BG can perform the dual role of providing surface area for thrombosis and supplying Ca 2+ ions; hence there will be an optimum ratio of SiO 2 to Ca 2+ ions, which are co-factors throughout the clotting cascade, for the fastest hemostatic response. The BG-induced coagulation rate, α, increases with increasing Si:Ca ratios and maximizes for the same Si:Ca ratio as the minimum R time (Si:Ca(R min x max )˜2.5). All blood clots induced by BGs resulted in stronger than natural clots (MA BC ≧62 and MA Natural =58 dyn/cm 2 ).
Example 2
Formulation of Mesoporous Bioactive Glass
[0081] The unique formulation of high surface area mesoporous bioactive glass that we have prepared has the ability to rapidly induce a blood clot when exposed to blood. In fact, the formulation we have prepared has a faster clotting time and results in a stronger clot than QuikClot™, the leading inorganic hemostatic agent currently available (see FIG. 3 ). Both the porous and non-porous formulations of bioactive glass possess this ability to rapidly promote blood coagulation. Because the porous and non-porous formulation of bioactive glass can be hydrated to different degrees, and consequently will deliver different amounts of heat upon hydration during medical application to a wound site, we can further tailor the rate of blood coagulation. Combinations of porous and non-porous bioactive glass can be formulated to the desired specifications of hydration and delivery of heat (see FIG. 4 ).
Example 3
Mesoporous Bioactive Glass with Varying Ratios of SiO2:CaO
[0082] This example shows that one make the bioactive glass with varying ratios of SiO2:CaO. At higher SiO2:CaO ratios (more silica), the material tends to clot blood faster. This is illustrated in both FIGS. 5 and 6 . As the amount of SiO2 relative to the amount of CaO is reduced, the kinetics of clot formulation are much slower. The difference in clotting kinetics between two bioactive glass samples with different SiO2:CaO is more pronounced with the non-porous samples. The mesoporous bioactive glass is a faster clotting agent than the non-porous samples, but the difference between samples is greater within the non-porous samples.
[0083] This example also shows that one can use combinations of porous and non-porous bioactive glass, as well as composites with multiple bioactive glasses of different SiO2:CaO ratios, to achieve any desired hydration capacity and heating response when in contact with blood (see FIGS. 7 and 8 ).
Example 4
Spherical Bioactive Glass
[0084] Spherical Bioactive glass is produced by an aerosol assisted method and with the same sol-gel precursor solution employed for bioactive glass previously described. Spherical bioactive glass accelerates the formation of a contact-activated clot. The activity of bioactive glass is dependent on the relative amount of contact activating agent to the surrounding blood volume ( FIG. 9 ).
Example 5
Host-Guest Composites
[0085] The porous architecture of mesoporous bioactive glass is ideal for the controlled release of biomolecules. These molecules can be immobilized on the oxide surface of pores. Each of these formulations wil have a unique release profile with regard to concentration and rate of release. The combination of porous bioactive glass and biomolecules is referred to as a host-guest composite.
[0086] Host-guest composites can also be prepared to release ions including, but not limited to, silver, magnesium and calcium ions. Silver ions have been shown to be antibacterial at parts per billion concentration in biological fluids. Magnesium and calcium ions are essential cofactors during the coagulation of blood. Certain formulations of porous bioactive glass can also sequester magnesium and calcium from blood to delay the coagulation in response.
[0000] Synthesis
[0087] Mesoporous bioactive glasses (MBGs were synthesized by co-assembly of a BG sol with a triblock copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) as the structure-directing agent through an evaporation-induced self-assembly (EISA) process. The dried gel was calcined at high temperature to remove the block copolymer and form mesopores. The final MBGs were ground into powders. The as-calcined MBGs have more accessible mesopore surface area and ordered pore structure. In vitro study showed a greater bone-forming bioactivity than conventional sol-gel derived BGs by fast formation of an amorphous bioactive HA layer.
Example 6
Bioactive Glass Cements
[0088] Bioactive glass cements were prepared by mixing bioactive glass powders with an ammonium phosphate buffer solution. The liquid component of MBGCs, an ammonium phosphate buffer solution, was prepared by dissolving 60.1 g (NH 4 ) 2 HPO 4 and 5.0 g NH 4 H 2 PO 4 in 100 mL water. The pH of the resulting solution was ˜7.3. MBGC cements were made by mixing the solid and liquid components at the ratio of 1 g to 1 ml. The cements were kept in the ambient environment to set. Before setting fully, they were soft enough to be kneaded or molded. Structural characterizations were typically carried out at ˜1 h after the mixing of the solid and liquid components of MBG, and no structural changes were observed after 1 h after mixing.
[0089] The assessment of the in vitro bioactivity of bioactive glass powders and cements was carried out in SBF at 37° C. SBF contained 142.0 mM Na + , 5.0 mM K + , 1.5 mM Mg 2+ , 2.5 mM Ca 2+ , 147.8 mM Cl, 4.2 mM HCO 3 , 1.0 mM HPO 4 2 , and 0.5 mM SO 4 2 . Its chemical composition is similar to that of human plasma. The solution had a pH of 7.3-7.4 and was kept at 37° C. before use.
Example 7
Surface Area Measurements of Mesoporous Bioactive Glass
[0090] This example presents data on the surface area measurements that have been made of the mesoporous bioactive glass of the invention. In FIG. 10 , the adsorption-desorption isotherm is presented. The lack of hysteresis suggests a channel-like structure without internal cages. This adsorption-desorption isotherm can be used to calculate the pore size distribution of the mesoporous bioactive glass based on the BJH model. A plot of the pore size distribution is illustrated in FIG. 11 .
[0091] The calculated surface area of mesoporous bioactive glass is displayed in FIG. 12 . Bioactive glass can be formulated with a surface area ranging from 300 m 2 /g to 1000 m 2 /g. The sample that was used for the measurements described in this example had a surface area of 960 m 2 /g. The internal pore diameter was calculated to be 3.1 nm based on the BJH model and 2.5 nm based on the BET model.
Example 8
Bone-Generating Activity of Bioactive Glass
[0092] The assessment of the in vitro bioactivity of bioactive glass powders and cements was carried out in simulated body fluids (SBF) at 37° C. SBF contained 142.0 mM Na + 5.0 mM K + , 1.5 mM Mg 2+ , 2.5 mM Ca 2+ , 147.8 mM Cl − , 4.2 mM HCO 3 , 1.0 mM HPO 4 3 , and 0.5 mM SO 4 2 . Its chemical composition is similar to that of human plasma. The solution had a pH of 7.3-7.4 and was kept at 37° C. before use. The in vitro assessment of in vivo bone-generating bioactivity is typically conducted by monitoring the formation of hydroxyapatite on the surface of bioactive glass after immersion in SBF. After mixing the bioactive glass powder with the ammonium phosphate buffer solution, weak x-ray diffraction peaks at 20=26° (002) and 32° (211) corresponding to hydroxyapatite are observed. The broad peak at 2θ=23° is due to the amorphous nature of the bioactive glass walls ( FIG. 13 ). The average hydroxyapatite crystal size nucleated after immersing BG60:36:4 in simulated body fluids for one day is 37 nm. The average hydroxyapatite crystal size nucleated after immersing BG80:16:4 in simulated body fluids for one day is 32 nm. Faster rates of hydroxyapatite were observed with BG60:36:4 compared to BG80:16:4.
Example 9
Isoelectric Point, Fast Acting, Clotting Agents, and Passivated Medical Device Surfaces
[0093] As described in U.S. provisional patent application No. 60/668,022, filed Apr. 4, 2005, we have identified four critical materials parameters that can be used to predict the hemostatic response for exposing a given oxide to blood. We have shown that blood coagulation can be induced rapidly through the dehydration of blood, application of an appropriate amount of heat, and by delivering ions, like calcium, that are cofactors in the blood coagulation network. Oxides with a surface charge will also induce a coagulation response. More specifically, the isoelectric point is the underlying principle effecting the surface charge induced contact activation coagulation response.
[0094] Every oxide material will possess an initial surface charge that is a function of both the isoelectric point of the material and the pH conditions of the immersing solution (see FIG. 14 ). By observing the rate of coagulation of blood upon exposure to a variety of inorganic oxides, we have observed that those materials with an isoelectric point below the pH of blood accelerate the coagulation response (see FIG. 14 ). Those materials with an isoelectric point above the pH of blood are observed to decelerate the coagulation response (see FIG. 15 ).
[0095] Designing rapid acting hemostatic agents requires an optimization of the four material parameters already identified: isoelectric point, hydration capacity, thermal application (heat), and control of the local electrolyte conditions. Similarly, designing passivated medical device surfaces for contact with blood requires a related, albeit opposite, optimization of these material parameters compared to a fast acting clotting agent. By selecting oxides of varying isoelectric points, it is possible to modulate the blood coagulation response from spontaneous coagulation to inhibition of coagulation. This control over the blood response is unique to inorganic oxides and offers major advantages over current organic based hemostatic technology. This relationship between isoelectric point and coagulation provides for the design of new bioactive glass compositions tailored to desired objectives in the regulation of hemostasis.
Example 10
Isoelectric Point and Low-surface-area Metal Oxides
[0096] It is well accepted that negatively charged surfaces activate the intrinsic pathway of the blood clotting cascade. The SiO 2 glass beads, which have the lowest isoelectric point (IEP=2.1) of all the low-surface-area oxides analyzed, initiated the formation of a detectable blood clot on average 2.9 min after exposure to sheep blood. Because this material has the lowest isoelectric point, under physiological conditions (pH=7.3-7.4), SiO 2 substrates will initially possess the greatest negative surface-charge density compared to the other oxides tested. The time until clot detection increases with the increasing isoelectric point of the low-surface-area materials studied ( FIG. 16 ). NiO has the isoelectric point that is closest to the pH of blood, and the average clot time induced by NiO is nearly indistinguishable from that of blood in its absence (R NiO =11 min and R Bloodstream =10.9 min). Zno has the highest isoelectric point of the materials studied (IEP=9.5) and was observed to actually delay the time until blood clot detection by about 1.5 min compared to sheep blood alone.
[0097] The fastest rate of coagulation, α (°), for the low-surface-area metal oxides, was observed with the SiO 2 glass beads (α=75.2°, IEP=2.1), which initially posses the most negative surface in blood compared to the other low-surface-area metal oxides studied ( FIG. 17 ). The slowest rate of coagulation was observed when ZnO was introduced to sheep blood (α Blood =50.2°; α ZnO =30.4°). ZnO possesses the maximum positive surface charge when immersed in blood. All of the oxides with an isoelectric point above the pH of blood were observed to decelerate the rate of coagulation compared to blood alone, and in particular, NiO, which has the closest isoelectric point to the pH of blood but will be positively charged after immediately contacting blood, was observed to reduce the rate of coagulation.
[0098] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention.
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The invention provides a homogeneous composition comprising a hemostatically effective amount of a charged oxide, wherein the composition has an isoelectric point, as measured in calcium chloride, below 7.3 or above 7.4. Typically, the charged oxide is selected from the group consisting of silaceous oxides, titanium oxides, aluminum oxides, calcium oxides, zinc oxides, nickel oxides and iron oxides. In some embodiments, the composition further comprises a second oxide selected from the group consisting of calcium oxide, sodium oxide, magnesium oxide, zinc oxide, phosphorus oxide and alumina. In a typical embodiment of the invention, the charged oxide is silaceous oxide, the second oxide comprises calcium oxide and the ratio, by molar ratio, of silaceous oxide to calcium oxide is 0.25 to 15. Optionally, the composition further comprises phosphorous oxide. Also described are methods of making and using such compositions.
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BACKGROUND OF THE INVENTION
The practice is known (West German Pat. No. 1.287.484) of measuring the thickness of the silver before the draft zone and according to the measured values to adjust in the axial direction pins carried on a disc defining a continuous circulating store. The positions of the pins relative to the disc are sensed and corresponding electrical control pulses are generated. The pulses are fed to a control device which alters the ratio of transmission of a taper-roller gearing and thereby the draft ratio of the draft zone in such a way that the silver leaving the draft zone exhibits essentially constant thickness. Such a store provided with pins is, however, suitable only for relatively low draft speeds. But with the high speeds utilized today, satisfactory setting of the pins is not possible since rapid adjustment of the pins leads to throwing, so that no uniform sliver thickness can be achieved.
For higher operating speeds the practice is, however, known of inserting dimensional analogue voltages determined by the scanning, unchanged into an electrical store and recalling them with a phase shift for the control of the separate drive of the draft stage (West German Pat. O/S No. 2 331 217). But such a method is inaccurate since dimensional quantities cannot be stored as unaltered values for long, causing faulty regulation.
As a result of partial discharge of capacitors used in storage devices because of leakage currents in the case of long stoppage times of the machine and by ageing and deterioration, accurate regulation cannot be guaranteed in the case of the known method.
SUMMARY OF THE INVENTION
This problem is solved in accordance with the invention if the deviations of the sliver thickness from the desired thickness and converted into analogue electrical voltages and then converted back into digital values and stored as such. These digital values, after a time corresponding with the time for conveyance of the scanned point in the sliver up to and into the draft zone, are read out of the storage register and converted back into analogue electrical voltages. The analogue voltages are then fed to a control device for regulation of the draft.
Since the electrical voltages corresponding with the fluctuations in sliver thickness are converted into binary numbers, then it is only necessary to record the presence or absence of an electrical voltage in the storage register, the magnitude of the stored values being irrelevant. After read out of the stored binary numbers, they are converted back into analogue voltages which accurately correspond to the analogue values before storage. In this way accurate adaptation of the draft to the fluctuations in the sliver as scanned is achieved, so that a really uniform sliver can be produced.
For performance of the method described, in accordance with the invention a digital-value stepping-storage is provided with an analogue digital converter connected before it and a digital analogue converter connected after it. An impulse generator operating in dependence upon the draft speed is associated with the digital-value stepping-storage. Because of the impulse generator operating in dependence upon the draft speed, the pulse frequency is positively synchronized with the draft speed.
The digital value stepping-storage is in one embodiment a conventional digital shift register.
The impulse generator may be connected to any one of the moving draft members. A particularly accurate result can, however, be achieved if the impulse-generator is connected to the draft member for which the speed is adjustable. In order to utilize the same impulse generator for controlling the drafting of different lengths of fibers upon which the draft point in the draft zone would need to be changed, in accordance with a further feature of the invention an adjusting-gearing is associated with the impulse generator.
Advantageously, the control device is connected control-wise to the draft rollers, and between the digital analogue converter and the control device, a harmonic generator is arranged.
Accordingly, it is an important object of the present invention to provide a method and device for leveling bands of fibers such as fleece, roving, and sliver.
Another important object of the present invention is to provide a leveling device for bands of fibers which can operate at high draft speeds.
These and other objects and advantages of the invention will become apparent upon reference to the following, specification, attendant claims, and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating an embodiment of the invention for leveling bands of fiber.
FIG. 2 is a modified form of the invention in diagramatic form illustrating a method and apparatus for leveling bands of fiber.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with FIG. 1, a sliver 1 is running in the direction of the arrow 10 through a draft zone 100 which is bound by draft rollers 11 and delivery rollers 12. The draft rollers 11 are driven via a gear 13 from a motor 14. The delivery rollers 12 are driven by the motor 14 via a taper-roller gearing consisting of cones 15 and 150 together with a belt 151 as well as via a control gear consisting of the gearwheels 16, 160, 161 and 162. For alteration of the draft, an adjusting fork 152 is associated with the belt 151, which is controllable by an adjusting electromagnet 153. By varying the electromagnetic force of the electromagnet 153, the position of the fork 152 is varied for adjusting the belt 151 along the cones 15 and 150.
At a distance before the draft zone 100, a scanner is connected. In accordance with FIG. 1, the scanner exhibits a stationary supporting roller 20 as well as a scanner roller 2 arranged at the end of a lever 21. On the lever 21, which is pivotable about an axis 22, an adjustable slide 23 is arranged which carries a pin 24 upon which a second slide 25 is arranged. The second slide 25 is seated on a second lever 26, the pivot 27 of which is arranged at the end of it remote from the axis 22 of the lever 21. By adjustment of the slide 23 along the lever 21, it is possible to adapt the scanner to the medium cross-sectional thickness of the sliver as is explained again in detail later. An electrical measuring device 3 is associated with the lever 26. This may be of various forms, for example, in accordance with one of the solutions shown in the West German Pat. No. 889 987. Thus, the electrical measuring device may exhibit, e.g., a projection (of iron) connected to the lever 26, which depending upon the position of the lever 26, plunges further or less far into a coil, whereby a correspondingly large electrical voltage is generated. This electrical voltage which may be read on a voltmeter 30 is fed to an analogue digital converter 4 which is connected to an pulse generator 40 driven by the motor 14. The output from the analogue digital converter 4 is connected to a stepping-storage 5. The stepping-storage 5 exhibits two stepping-devices 50 and 51 which are driven by the motor 14 via gears 52 and 53. Each stepping-device 50 and 51 exhibits contacts 500 and 510, respectively, arranged in circles which are scanned in succession by an arm 501 and 511, respectively. The center 502 of the arm 501 is connected to the analogue-digital converter 4 while the center 512 of the arm 511 is connected to a digital analogue converter 41. The contacts 500 and 510 are connected in respective pairs to a storage element 54. The connection between the contacts 500 and 510 and the storage elements 54 or the position of the arms 501 and 511 is so formed that each storage element 54 is connected at different times to the analogue digital converter 4 or respectively to the digital analogue converter 41, the timeshift representing the storage time. The storage time, however, is aimed at the time for conveyance of the scanned point in the sliver 1 up to and into the draft zone 100.
A tachometer generator 154 is connected to the cone 15, while another tachometer generator 155 is connected to the cone 150. The tachometer generator 155 is connected to ground 157 via a resistor 156. One end of a potentiometer 158 is connected to the lead between the tachometer generator 155 and the resistor 156 and the other end is connected to the tachometer generator 154. The arm 159 taps off the voltage from the potentiometer 158 and feeds it to an amplifier 42 the second input of which is connected to the digital analogue converter 41. For control of the belt, the amplifier 42 is connected to the adjusting electromagnet 153.
In operation, the draft rollers 11 and the delivery rollers 12 are driven at a certain speed ratio relative to one another in order to achieve a definite draft of the sliver 1. The draft ratio is established by a suitable selection of the gearwheels 16, 160, 161 and 162 and may be altered at will. Alterations of the draft ratio, which becomes necessary because of fluctuations in the thickness of the sliver 1 are automatically performed by adjustment of the belt 151 along the cones 15 and 150. For this purpose, the sliver 1 on its way into the draft zone 100 before reaching the draft rollers 11 is led between the supporting roller 20 and the scanning roller 2. In order to run the belt 151 in a central position on the cones 15 and 150 at the desired thickness of the undrawn sliver 1, so that regulation of the draft which may possibly become necessary is possible through adjustment of the belt 151 in both directions along the cones 15 and 150, the slide 23 is brought into an appropriate fundamental position on the lever 21 and secured in this position.
At the transmission ratio hereby resulting because of the effective leverages of the levers 21 and 26, a certain electrical voltage is generated in the measuring device 3 which can be checked by the permanent or plug-in voltmeter 30. The electrical voltages generated by the measuring device 3 are fed to an analogue digital converter 4. These electrical voltages fluctuate according to the fluctuations in the thickness of the undrawn sliver 1. In the analogue digital converter 4, the electrical voltages are converted into binary numbers at the rhythm determined by the impulse generator 40. The pulse frequency of the impulse generator 40 is dependent upon the speed of the motor 14, and hence, upon the speed at which the sliver 1 is being passed through the draft zone. By suitable selection of the transmission ratio of the gearing 53 for the stepping-storage the time interval between two successive impulses is just as long as the time the arm 501 and 511 needs to get from one contact 500 or 510 to the adjacent contact. By suitable wiring or by arrangement of the arms 501 and 511 appropriately shifted in phase with respect to one another, the binary values delivered by the analogue digital converter 4 storage elements 54 can only be read out when the scanned point in the sliver 1 has reached the draft zone 100. The storage period in the stepping-storage 5 is therefore adjusted to the distance of the scanning roller 2 from the draft rollers 11 and to the speed of conveyance of the sliver 1. The path that the digital signals take from analogue digital converter 4 to digital converter 41 is through center contact 502, arm 501, contact 500, through storage element 54, contact 510, arm 511, through center contact 512 to digital converter 41.
Since the analogue values generated by the measuring device 3 is converted into digital values, loss of stored information when there is a voltage drop is impossible, since it is not voltage values but numerical values that get stored. The storage element 54 is in that case not to be understood as a single element but embraces a plurality of elements or bits for the individual binary numbers 1, 2, 4, 8, 16, 32, etc. the combination of which reproduces the respective electrical quantity.
The pulses released from the stepping-storage 5 after the established storage time are converted back again in the digital analogue converter 41 into electrical quantities. Storage in the form of digital values guarantees that the electrical quantities fed to the analogue digital converter 4 and the electrical quantities released by the digital analogue converter 41 are exactly equally large. This is essential for accurate draft regulation.
The electrical quantities which the digital analogue converter 41 emits are fed to an amplifier 42. In addition, an actual value is advanced to the amplifier 42 which is tapped off by the arm 159 from the potentiometer 158. The potentiometer 158 is preset to correspond with the required draft ratio, the values of voltage corresponding with the r.p.m. at the time, of the shafts 17 and 18 carrying the cones 15 and 150, being generated by the tachometer generators 154 and 155 and fed to the potentiometer 158. Hence, the actual value corresponds with the real draft ratio. The amplifier 42 compares this actual value with the value from the digital analogue converter 41 and actuates the adjusting electromagnet 153 to correspond with possible deviations. The adjusting magnet 153 then adjusts the belt 151 on the cones 15 and 150 by means of the adjusting fork in the direction hereby determined, whereby the draft is altered.
Depending upon the material, it may be desirable if the sliver 1 is drawn at differing speeds. To do this, the speed of the motor 14 and the position of the arm 159 on the potentiometer 158 merely needs to be altered.
FIG. 2 illustrates a modified form of the invention in which adaptation to the desired thickness of the sliver to be drawn is effected not by alteration of the transmission ratio of the lever 21 but by means of a potentiometer 31. This potentiometer 31 is set so that the indicator device 30 (FIG. 1) when the thickness of the sliver 1 is at its desired value always indicates a certain electrical quantity. Instead of a voltmeter, a device 300 may also be used which exhibits a certain number of signal lamps or luminous diodes 301 which light up in dependence upon the electrical voltage generated by the measuring device 3. The number of signal lamps or luminous diodes 31 illuminated is, therefore, a dimension of the electrical voltage and thereby of the measured thickness of the sliver 1. This device 300 may be permanent or of plug-in type.
In the case of the embodiment of the invention as shown in FIG. 2, a digital shift register 55 is used as stepping-storage. This is very simple in construction and conveys the stored binary numbers at the rhythm prescribed by the impulse generator 40 through the storage.
Depending upon the length of the fibers in the sliver 1, the actual draft point is shifted in the draft zone 100. While the draft point with shorter fibers lies nearer to the draft rollers 11, with increasing fiber length it moves in the direction of the delivery rollers 12. Hence, also the distance of the scanning roller 2 from the draft point is altered to correspond with the fiber length. In order to take this fact into account, an adjusting gearing 400 may be connected before the impulse generator 40 so that the pulse frequency may be altered correspondingly by alteration of the gear ratio of the adjusting gearing 400. The values stored in the digital shift register 55 are, therefore, shifted at an altered speed through the storage, whereby adaptation of the resultant distance of the scanning point from the draft point is possible. But by selection of a digital shift-register 55 having a number of outputs, it is also possible to select the output corresponding with a certain number of stepping stages in which case the frequency of the impulse generator does not have to be altered.
As a comparison of FIGS. 1 and 2 shows, either the delivery rollers 12 or the draft rollers 11 may be regulated. Hence, the motor 14 acts either on the shaft between the draft rollers 11 and the cone 15 or on the shaft between the delivery rollers 12 and the cone 15.
If the delivery rollers 12 are regulated (FIG. 1) the sliver 1 gets fed to the draft zone 100 always at the same speed, but led away out of the draft zone at variable speed. In accordance with FIG. 2, the sliver 1 is fed to the draft zone 100 at variable speed, but led away from the draft zone 100 at constant speed. If it is also possible as shown in FIGS. 1 and 2 to associate the impulse generator 40 fundamentally with the draft roller side a more accurate result is possible since on that side the impulse generator 40 takes the regulation into consideration. For this purpose, the impulse generator in accordance with a preferred embodiment of the invention is always associated with the draft member, the speed of which is being regulated. In accordance with FIG. 2, the speed of the draft rollers 11 is being regulated; consequently, the impulse generator 40 is being driven in dependence upon the speed of the latter. In the case of the embodiment as FIG. 1, the result of the regulation can be improved if the impulse generator 40 is driven in dependence upon the speed of the delivery rollers 12.
When the draft rollers 11 are regulated in accordance with a further feature of the invention, a harmmonic generator 43 may be arranged between the digital analogue converter 41 and the amplifier which smoothes the electrical voltages to values which are associated with a hyperbolic function. By this means, satisfactory speed regulation of the draft rollers 11 is achieved.
Instead of a potentiometer 158, a divider 44 may also be provided, which automatically delivers from the voltages delivered by the tachometer generators 154 and 155 an actual value which independently of the delivery r.p.m. always corresponds with the draft ratio. This value is passed on to the amplifier 42.
As the foregoing description shows, in accordance with the invention, the deviation of the sliver thickness from the desired thickness is determined in the form of analogue electrical quantities, normally in the form of voltage values. These values before storage are converted into binary values and inserted as binary values in a stepping-storage. Since the essential thing is only which bits are operated in this case but not which value is to be stored in each bit, electrical losses which possibly occur play no part. The binary values released again after a time corresponding with the time of conveyance of the scanned point in the sliver 1 up to and into the draft zone 100 are converted back into analogue values which are unaltered as compared with the corresponding electrical quantities before storage. These electrical quantities are then fed to the control device formed, for example, as an adjusting magnet 153 which then performs an accurate regulation of the draft. Through the accurate reproduction of the electrical voltages, satisfactory regulation of the sliver thickness is achieved, which by adjustment of the frequency of the impulse generator 40 or by alteration of the number of stages in the digital shift-register 55 may be adapted very accurately even to the shift of the draft point because of differing fiber lengths.
The impulse generator 40 is actuated always in dependence upon the motor 14 or a part driven by it, so that it operates always in dependence upon the draft speed. In both of the embodiments, the impulse generator 40 is utilized to synchronize the storage time for the digital signals in the storage register with the drafting speed. Control in dependence upon the network would imply an additional gearing for adaptation to the draft speed.
Naturally, it is also possible instead of the transmission by means of two cones 15 and 150 together with a belt 151 to employ two separate motors for the draft rollers 11 and the deliver rollers 12. The control device would then have to be adapted to correspond with such a driving device. But even in the case of a conical roller, gearing the control device may be of different form, for example, in accordance with West German Pat. No. 1,287,484.
While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.
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A method and apparatus for automatically leveling a band of fibers such as sliver, roving and the like by varying the drafting speed of a drafting mechanism responsive to variations in the thickness of the band. Analogue signals are produced by variations in the thickness of the band and are converted to digital signals for being stored in a digital register. After a period of time, corresponding with the time for conveyance of the scanned point in the sliver up to and into the draft zone, the information is read out of the storage register and converted back to an analogue signal. The analogue signal is compared with another signal representing the actual drafting speed for producing a compared signal for controlling the drafting speed.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of co-pending U.S. provisional application Ser. No. 60/820,711, filed on Jul. 28, 2006; 60/823,571, filed on Aug. 25, 2006; 60/825,359, filed on Sep. 12, 2006; and 60/868,233, filed on Dec. 1, 2006. The disclosures of the co-pending provisional applications are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of antennas and FM receivers.
BACKGROUND
[0003] The field of consumer electronics places a high value on minimizing size and improving portability, particularly in wireless communication devices. The need for an adequately long antenna, however, limits how small certain wireless devices can be. Antenna efficiency is a function of many parameters, including an antenna's length. Generally, most receivers function well enough with antennas half the wavelength or one quarter of the wavelength of the signal being received. Receivers using antennas substantially less than one quarter of the wavelength, however, will have less adequate reception.
[0004] The wavelength (λ) of a signal equals the speed of light (c) divided by the frequency (f). For example, 2.4 GHz signals, such as those used by Bluetooth devices, cordless phones, wireless routers, and other household devices have wavelengths less than 13 centimeters. FM radio signals, which range from approximately 87 MHz to 108 MHz, have wavelengths from 277 centimeters to 344 centimeters.
[0005] A λ/4 antenna for a 2.4 GHz headset only needs to be about 3 cm, compared to about 86 centimeters for a headset receiving radio waves. A high frequency device such as a wireless headset for a cell phone can, therefore, still be quite small and have an antenna capable of good reception. Receiving lower frequency signals such as radio waves on that same headset, however, would be quite challenging. Most typical handheld radios overcome these limitations by either using an extendable metal antenna or by using the radio's headphone cords as an antenna. These two solutions, however, are both less than ideal because they both greatly increase the physical size of the system.
[0006] It would be desirable to build a small device capable of receiving lower frequency signals without the need for bulky external antennas.
SUMMARY OF THE INVENTION
[0007] An aspect of the present invention calls for connecting a receiver to the human body to create a virtual antenna. Another aspect of the present invention calls for using impedance matching circuitry to minimize energy loss at the antenna/receiver interface. Another aspect of the present invention calls for using real-time impedance matching circuitry to adjust circuit parameters in accordance with changes detected in the impedance of the body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows a receiver embodying aspects of the present invention.
[0009] FIGS. 2 a - b show alternate views of a headset receiver embodying aspects of the present invention.
[0010] FIG. 3 shows an example of impedance matching circuitry embodying aspects of the present invention.
[0011] FIG. 4 shows an example of real-time impedance matching circuitry.
DETAILED DESCRIPTION
[0012] FIG. 1 depicts a diagram of a human body with an FM headset. An average body (˜5-6 feet), is roughly half of the wavelength of an FM radio wave and has a resonant frequency around 76 to 86 MHz, both of which are desirable characteristics for an FM antenna. The body, however, is a poor conductor, and due to the small size of the FM headset, the antenna connection will have a high impedance. The present invention overcomes these deficiencies and uses the human body to aid in the reception of radio waves.
[0013] FIGS. 2 a and 2 b show a headset device 220 containing a receiver 210 embodying aspects of the present invention. The device 220 is configured to be worn on the ear 230 . Although this particular embodiment shows a headset 220 , the same concepts can be applied to devices connected to the wrist, ankle, waist, or any other part of the human body. A receiver 210 inside the device 220 can have an antenna input which can be connected to a conductive, external part of the device 220 that touches the body. This connection can be achieved by enclosing the device 220 in a conductive casing, covering the outside of the device 220 with a metallic paint, or by using a conductive contact pad 250 to touch the body. Rather than having a conductive material directly contact the skin, the device can also be capacitively coupled to the skin by having a conductive surface separated from the skin by a layer of plastic or coating of paint. A contact pad 250 can allow the device designer, for example, to build a device 220 to be worn on the ear but where the contact point with the body is on the cheek or neck. The contact pad can be separated by a distance 260 from the receiver 210 . The device can be configured to either have the body serve as the only antenna or to have the body extend a built-in antenna.
[0014] Typical FM receivers have impedances of 75 to 300 ohms, while the system described herein has an impedance of roughly 1000 ohms, for example. In order to minimize the energy loss at the antenna/receiver interface and maximize power transfer, an aspect of the present invention may utilize an impedance matching network, such as the LC tank circuit shown in FIG. 3 for example. The circuit of FIG. 3 contains an antenna input 310 , a capacitor (C 1 ) 320 , and an inductor (L 1 ) 330 . The capacitor 320 and inductor 330 can be connected in parallel to the antenna input and a ground 340 .
[0015] An LC tank circuit can form a desirable impedance matching network because it can alter the impedance of the circuit with minimal power loss compared to a resistor or other circuit elements and configurations. The LC tank circuit can also be configured to act as a filter by maximizing transmission of signals at the desired frequency and minimizing transmission of signals at other frequencies. Values for the capacitor 320 and inductor 330 may be chosen so that the resonant frequency of the LC tank circuit is the desired transmission frequency. When the resonant frequency of the LC tank circuit corresponds to the desired transmission frequency, the efficiency of power transfer from the antenna to the receiver will be maximum.
[0016] A device, however, may not have a specific transmission frequency and may need to cover a band of frequencies. The values of the inductors 330 and capacitors 320 can be customized to the particular needs (e.g. narrow bandwidth or broad bandwidth) of each specific device. It is appreciated that the matching network of FIG. 3 represents only one of many matching networks that can be utilized.
[0017] The antenna input 310 can be connected to the human body, and the ground 340 can be connected to the ground of a PC board. The grounding 340 and antenna input 310 can also be reversed, with the ground 340 being connected to the human body instead of the antenna input.
[0018] The impedance of the system will change depending on the frequency of the signal being transmitted, as well other factors, such as where the device is connected on the body. In order to improve performance, an aspect of the present invention calls for real-time impedance matching to optimize the received signal level. FIG. 4 shows a diagram for a matching network circuit that can dynamically adjust to the changing impedance of the system. The circuit of FIG. 4 contains an antenna input 410 and a ground 440 . The antenna input 410 can be connected to the body, and the ground 440 can be connected to the ground of a PC board. Like the circuit of FIG. 3 , the matching network of FIG. 4 can contain capacitors 420 and inductors 430 connected in parallel to the antenna input 410 and ground 440 . An aspect of the present invention calls for the capacitor 420 to be a tunable capacitor bank that can be adjusted based on the measured impedance at the interface of the body and the antenna input 410 . The inductor 430 might have a value of approximately 100 nH, and the tunable capacitor bank might, for example, be able to adjust from approximately 5 pF to 20 pF.
[0019] Digital detection circuitry 470 can detect the impedance at the interface of the body and the antenna input 410 and adjust the tunable capacitor bank accordingly. Alternatively, the digital detection circuitry 470 can adjust the tunable capacitor bank based on a detected indication of signal strength. Based on either the detected impedance or the detected signal strength, the digital detection circuitry can use a software-based algorithm for tuning the capacitor bank so that the resonant frequency of the matching network is close to or the same as the transmission frequency. Varying the resonant frequency of the matching network can allow the matching network to achieve maximum efficiency of power transfer at multiple frequencies instead of at a specific frequency. Tunability to accommodate multiple frequencies can be desirable for devices that need to cover a wide band of frequencies.
[0020] Another aspect of the present invention calls for the real-time impedance matching to be performed dynamically. The digital detection circuitry 470 can act as a feedback loop that constantly monitors and adjusts the impedance of the network, even when the frequency of the signal being received is not changing. In other embodiments, the digital detection circuitry can include a Low Noise Amplifier 450 . Additionally, aspects or the entirety of the FM receiver can be combined with aspects of the digital circuitry.
[0021] The matching network of FIG. 4 can also contain a bypass capacitor 460 to block DC components of signals and a LNA 450 to amplify the received signal before sending it to a receiver. The signal can be transmitted to the receiver from the output 480 of the LNA 450 . In one embodiment of the present invention, the capacitor 420 and LNA 450 can be on-chip, while the inductor 430 and bypass capacitor 460 can be off-chip. The locations of the various components on or off the chip can be altered.
[0022] Although aspects of the present invention, for ease of explanation, have been described in reference to an FM radio receiver, the scope of the present invention includes a wide range of devices which can receive a wide range of signals at different frequencies. For example, aspects of the present invention could be included in two-way radios, cell phones, household cordless phones, AM radios, non-U.S. radios which operate at different frequencies (e.g. Japan where radio signals are transmitted at 76-90 MHz), and virtually any other miniature wireless receiving device.
[0023] The previous description of embodiments is provided to enable a person skilled in the art to make and use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles and specific examples defined herein may be applied to other embodiments without the use of inventive faculty. For example, some or all of the features of the different embodiments discussed above may be deleted from the embodiment. Therefore, the present invention is not intended to be limited to the embodiments described herein but is to be accorded the widest scope defined only by the claims below and equivalents thereof.
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An apparatus and method for receiving wireless signals couples an antenna input of a receiver to a human body and receives a signal conducting from said body. Impedance matching circuitry lessens signal power loss at the antenna input. Parameters of the impedance matching circuitry can be adjusted based on a detected impedance, a detected signal strength, or the frequency of the signal.
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This is a divisional of copending application Ser. No. 08/135,046 filed on Oct. 12, 1993.
This invention relates to the treatment of organic materials stored in large flexible storage bags and more particularly to the placement of conduits inside the bags to be used as desired to treat the stored materials with a media flowing through the conduits.
BACKGROUND OF THE INVENTION
An array of materials are stored in large plastic bags, e.g., bags that are 4-12 feet in diameter and 300 feet in length. Bags replace silos for the storing of silage. Bags replace granaries for the storage of grain. Bags replace outdoor composting piles for composting garbage. The three examples given have three different objectives. In the case of silage storage, a cut up or ground up agricultural crop, e.g., corn, is stored in a moistened condition. The enclosed crop ferments during the storage period which converts the material to silage, i.e., the pickled state of the crop material. The material is preserved in this pickled state for many months and is a popular form of feed for cattle during the harsh winter months in regions where pasture grass is not available during these months.
In the case of storage of grain for human consumption, pickling is not acceptable. Thus, grain is stored in a dry state. In absence of moisture, grain crop materials will not ferment and the dry grain sealed in a moisture proof container, e.g, a large plastic bag, can be safely stored for many months.
In the case of composting, the exact opposite of grain and silage storage is desired, i.e., the preservation of the material. Composting by definition is the decomposing of a material to rapidly return it to a form that is environmentally acceptable. It is an acceleration of the natural process of rotting and is achieved by exposing the material to a proper balance of moisture and air.
In summary, the fermenting process for producing silage requires a high level of moisture content, i.e., a moisture content above about 22%. Storage preservation for grain requires a low level of moisture content, i.e., below about 15%. Decomposition of garbage requires a moisture content (in the presence of air) of between about 18% to 90%.
Achieving the silage objective is the easier of the three processes. The crop is cut in a green state in which the moisture content is high. It is immediately chopped and placed in storage and as the crop naturally cures, the moisture that is naturally released produces the high moisture content.
Grain storage is a far greater problem. Ideally grain is allowed to totally ripen on the stalk at which point the grain is naturally dry, or it is cut in a semi-ripened state and allowed to lay on the ground where the uncured portion cures and releases its moisture to the atmosphere. However, this presumes that the weather is cooperative. Often it is not. Heretofore, when farmers were forced to harvest their grain crops under conditions where grain was too wet for storage, expensive grain drying techniques had to be employed before the crop could be stored.
The process of decomposing to accelerate rotting requires periodic, controlled exposure to moisture and air and, accordingly, it is an objective of the present invention to provide a means treatment of materials stored in large plastic storage bags including (but not limited to) all three of the above applications.
BRIEF DESCRIPTION OF THE INVENTION
The preferred embodiment of the present invention provides a perforated conduit lengthwise through the interior of the bag. Access to one end of the conduit, e.g., through a hole in the bag end, enables the introduction of a media, e.g, air, into the conduit to be dispersed throughout the material. An outlet may be provided at the opposite end to exhaust the air.
The problem of laying the conduit internally through the length of the bag is accomplished with rigid feed tubes that are mounted in the tunnel of a bagging machine. The feed tubes extend rearwardly in the tunnel to a position where the filled bag is being deployed from the tunnel. The feed tubes have a forward end that is open to the exterior of the tunnel. A roll of flexible perforated conduit is carried on the machine exterior and is fed through the feed tubes into the bag. Crushing and displacement of the conduit is thereby prevented in the area of the tunnel where the material being bagged is in motion. Where the conduits exit from the rigid tubes, the material is substantially static and thereby displacement and damage to the conduits is avoided.
When the bag is totally filled, the bag end is tied around the conduit end which is extended to the bag exterior. (Alternatively, a separate opening is provided in the bag through which the conduit end is extended.) Typically a blower is connected to the exposed exterior end and ambient air is blown through the conduit. An opening is provided in the opposite end of the bag for exhausting the air. Monitors may be provided along the bag (having a probe injected into the material of the bag) to measure moisture content. Alternatively, samples of the bagged material, e.g., grain are simply extracted from the bag and tested. For grain, air is blown through the material until the moisture content is reduced to 15% or less. For compost, ambient air may be blown through the conduit to reduce the moisture content down to the range of between 18% and 22% or if moisture is required, a water saturated air, e.g, steam or even liquid water may be introduced through the conduit. Silage, of course, needs to be maintained at above 22% moisture content and may be accordingly treated.
The above discussion very generally explains the method and apparatus for treating bagged materials and both will be more clearly understood by reference to the following detailed description and drawings referred to therein. Whereas this detailed description is primarily directed to grain storage, the reader will appreciate the ready application of the structure and processes to various other organic materials.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates the process of the invention for treating bagged materials.
FIG. 1a illustrates a section of perforated conduit used for treating the bagged materials.
FIG. 1b illustrates a section of non-perforated conduit to be coupled to the perforated conduit of FIG. 1a and extended through the bag end.
FIG. 2 schematically illustrates the process and apparatus of the invention whereby conduit is placed in a flexible bag being filled with the material to be treated by the process of FIG. 1.
FIG. 3 is a perspective rear view of the apparatus of FIG. 2 without the bag and illustrating the conduit feeding tubes in more detail.
DETAILED DESCRIPTION OF THE INVENTION
Reference is made to FIG. 1 which illustrates the process of treating the bagged materials. The bag 10 as illustrated is filled with a material which may be silage, grain, compost or other organic material which is capable of fermenting and/or decay. If the material 12 is grain that is in a too-moist condition for conventional storage, i.e., with a moisture content above 15%, it must be dried in order to prevent decay or fermenting. If the material is garbage that is to be composted, it must be provided, e.g., with oxygen as well as moisture to maintain the decaying process. In either event, the treatment prescribed is most likely to be aeration of the material with ambient air. As illustrated, a perforated conduit 14 is laid along the interior of the bag substantially the full length of the bag. The conduit is placed close to the bottom, e.g, about a foot off the bottom of the bag. It is believed that it is preferable to provide multiple conduits, e.g., four conduit sections along the bottom as illustrated but the number and location are somewhat determined by the design of the bagging apparatus and the materials and the condition of the materials being bagged. Other patterns of conduit placement may well prove to be as successful or even preferred to that illustrated and thus the invention is not limited to the illustrated arrangement or placement of the conduits.
The conduit 14 and the pattern of perforations provided therein is illustrated in the enlarged view of FIG. 1a. A short section of the conduit 14 as shown includes long narrow slits 16, e.g., having a width of about 1/16 inch, a length of about 3/4 inch and a diameter of 3 inches. The conduit is corrugated to have rigidifying ribs and intermediate grooves wherein the slits are provided. A known acceptable conduit is a corrugated conduit formed of semi-flexible plastic available from the Familian N.W. Company under the trade name ADS Sewer/Drain Pipe.
With reference to FIG. 1, the start-up end 18 of the conduit may or may not be plugged as desired to control the flow rate through the slots 16 and a rearmost section 18 of the conduit will not be perforated so as to maintain air pressure through the conduit until flowing air reaches the filled portion of the bag. The transition from perforated to non-perforated conduit can be provided in a number of ways. For example, as illustrated in FIG. 1b, different sections of the conduit can be readily coupled together. Thus, once the end of the bag is determined, the perforated conduit 14 can be severed and a non-perforated section 18 can be added for extension out the end of the bag. As shown, the end of conduit section 18 can be split and the circumference reduced (by overlapping the split sides as indicated by full line S and S') to fit the end of the perforated conduit. A more simple approach would be to simply extend the same perforating conduit out through the bag end but wrap that portion designated as section 18 with tape or the like to close the perforations. A third alternative is to generate the perforations as the conduit is being placed in the bag and simply discontinue the perforations when the bag end is reached.
As noted from FIG. 1, a blower 20 is schematically illustrated including an outlet nozzle 22 that is attached to the end 24 of the conduit 14. The treatment process as illustrated is thus the intake of ambient air to the blower 20 as illustrated by arrows 26, and the forced flowing of the air through the conduit as indicated by arrows 28 and into the material 12 as indicated by arrows 30.
As of the filing of this application for patent, insufficient data has been developed to determine the actual pattern of air flow from the conduit 14 into and through the material contained in the bag 10 or the optimum number and arrangement of the conduits provided along the interior of the bag. Nevertheless, the apparatus and processes described herein have been produced and operated under test conditions sufficiently to determine that the process does function to produce the desired results. Such has been established by the periodic extraction of grain samples from the bag at intervals along the length of the bag which were lab tested and found to be satisfactorily reduced in moisture content following treatment. The grain was initially determined to have a moisture content exceeding 18% when placed in the bag and following aeration as illustrated in FIG. 1, the moisture content along the length was reduced to below 15% moisture content.
Whereas the bags 10 utilized in this process are both moisture proof and air tight, it was believed necessary to provide a venting outlet. By placement of a single vent at the end illustrated as outlet 34, it is believed that the path of the air flow 30 is caused to flow outward and rearward as suggested by the arrows 30 toward the outlet 34 to be vented to the atmosphere as indicated by arrows 36.
Reference is now made to FIG. 2. Basically the machine of FIG. 2 but without the venting components which is explained hereafter is disclosed in detail in the commonly owned U.S. Pat. No. 5,140,802 and is incorporated herein by reference. In essence the machine 38 includes a hopper 40 for receiving grain 42, e.g., from a truck 51 which is augured from the hopper 40 by an auger 44 to a tunnel 46. The grain 42 is piled in the tunnel and flows from the pile into the bag 10. As the bag fills, the pile height increases and the forward pressure against a forward angled wall 48 of the tunnel 46 causes forward movement of the tunnel and incremental deployment of the bag which is folded or gathered around the tunnel and which is denoted 10'. As described above, the machine is disclosed in detail in the '802 patent.
The added structure for venting or treatment of the material will be explained but first it should be appreciated that there are known bagging machines for bagging silage and compost materials an example of which is illustrated in U.S. Pat. No. 4,337,805. The venting structure which will now be explained is readily adapted with minor modifications to these other structures.
The added structures will be explained with reference to both FIGS. 2 and 3. FIG. 3 is a perspective view looking into the back end of tunnel 46 with the bag removed (and, of course, with no grain occupying the tunnel interior).
As shown in FIG. 3, four rigid metal tubes 50 extend from an exterior open end 52, down through the top of the tunnel 46 along the rearwardly declining face of rearward wall 48. At a position above the bottom of the tunnel, the tubes 50 curve away from wall 48 to form a rearwardly projected end section 54 having an end opening 56 located approximately at the rear end of the tunnel (exclusive of the liner 1 shown in FIG. 3 which projects rearwardly beyond the tunnel end shown in dash line and into the bag as explained in the '802 patent).
The position of the rear opening 56 at the rear end of the tunnel as shown in the drawings is desirable for several reasons. The grain being deposited in the tunnel is in a state of movement as the tunnel first fills with grain and then flows rearwardly into the bag. This flow of grain (or silage or compost material) will disrupt the placement of a loose flexible hose inside the tunnel. Thus, the rigid feed tube preferably extends to the end of the tunnel so that the flexible conduit 14 is placed directly into the bag where the grain is at rest. On the other hand, it is desirable not to have the tubes extended rearwardly of the tunnel where it adds to the overall length and creates problems in packaging and shipment of the machine. An obvious variation is to provide removable extensions for the feed tubes 50 if additional rearward length is deemed desirable.
Referring to FIG. 2, it will be appreciated that the preferred conduit 14 is a flexible plastic that can be formed into a roll as illustrated at 58 and mounted on a reel (represented by shaft 60). Once the conduit is fed through the rigid feed tubes 50 to be placed under the grain 42, the further feeding of the conduit will be automatic. That is, the conduit portion residing in the bag will be held in place by the weight of the grain and forward movement of the machine will simply unroll additional conduit from the reel 60.
There are numerous variations that are possible. The objective, of course, is to provide treatment, e.g., aeration, consistently throughout the bag material. A single conduit may be sufficient in some cases. The conduit may preferably be positioned in the center of the bag. A plurality of conduits, e.g., four, may be preferably positioned symmetrically through the bag. Silage bagging machines have different mechanisms and it may be preferable to extend the tubes along the sides or along the top of the bagged material. The users of the equipment and methods employed will vary from one application to the other and the location of the conduits and the feed tubes will be varied as well. In all cases where loose flexible conduit is utilized, it is believed that a securely positioned rigid feed tube is important to avoid displacement due to material turmoil caused by the filling process. Whereas a rolled flexible tube is believed most convenient, it is also contemplated that rigid conduit sections may be utilized with successive sections being coupled one to the other as they are fed through a straight feed tube and into the bag.
All of the above and numerous variations will become apparent to those skilled in the art. Accordingly, the scope of the invention is determined by the claims appended hereto.
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A method and apparatus for treating bagged materials. A bagging machine is equipped with feed tubes that feed a conduit through a bag filling tunnel of the machine and through the open end of the bag and into the bag. The conduit is perforated and when the bag is filled, the length of the conduits is extended out through the bag end to be connected to a treatment media, e.g., forced air. An opening is provided at the rear end to provide an exhaust opening for air that is forced into the conduit, out the perforations and through the bagged material. The air will dry the material to lower the moisture content or provide oxygen as may be desired to enhance decomposition. Water may also be introduced as desired.
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FIELD OF THE INVENTION
The present invention relates to a perforator for use in perforating and fracturing well completions particularly, although not exclusively, perforators for use in tubing conveyed perforating guns for explosively perforating a well-bore casing, or perforating guns lowered on a slick line for perforating a tubing string or drill pipe string of wells such as, for example, oil, gas, water and steam wells.
BACKGROUND TO THE INVENTION
By far the most significant process in carrying out a completion in a cased well is that of providing a flow path between the production zone, also known as a formation, and the well bore. Typically, the creation of such a flow path is carried out using a perforator, with the resulting aperture in the casing and physical penetration into the formation via a cementing layer being commonly referred to as a perforation. Although mechanical perforating devices are known, almost overwhelmingly such perforations are formed using energetic materials e.g. high explosives. Energetic materials can also confer additional benefits in that may provide stimulation to the well in the sense that the shockwave passing into the formation can enhance the effectiveness of the perforation and produce increased flow from the formation. Typically, such a perforator will take the form of a shaped-charge. In the following, any reference to a perforator, unless otherwise qualified, should be taken to mean a shaped charge perforator.
A shaped charge is an energetic device made up of an axisymmetric case within which is inserted a liner. The liner provides one internal surface of a void, the remaining surfaces of the void being provided by the enclosure. The void is filled with a high explosive such as HMX, RDX, PYX or HNS which, when detonated, causes the liner material to collapse and be ejected from the casing in the form of a high velocity jet of material. It is this jet of material which impacts upon the well casing creating an aperture and then penetrates into the formation itself. The liner may be hemispherical but in most perforators is generally conical. The liner and energetic material are usually encased in a metallic case, conventionally the case will be steel although other alloys may be preferred. In use, as has been mentioned the liner is ejected to form a very high velocity jet which can have great penetrative power.
Generally, a large number of perforations are required in a particular region of the casing proximate a formation. To this end, a so called gun is deployed into the casing by wireline, coiled tubing or indeed any other technique know to those skilled in the art. The gun is effectively a carrier for a plurality of perforators which may be of the same or differing output. The precise type of perforator, their number and the size of the gun are a matter generally decided upon by a completion engineer based on an analysis and/or assessment of the characteristics of the completion. Depending on the nature of the formation, the aim of the completion engineer may be either to obtain the largest possible aperture in the casing or to obtain the deepest possible penetration into the surrounding formation. Thus, in an unconsolidated formation, the former will be preferred whereas in a consolidated formation the latter will be desired. It will be appreciated that the nature of a formation may vary both from completion to completion and also within the extent of a particular completion.
Typically, the actual selection of the perforator charges, their number and arrangement within a gun and indeed the type of gun is left to the completion engineer. The completion engineer will base his decision on an empirical approach born of experience and knowledge of the particular formation in which the completion is taking place. However, to assist the engineer in his selection there have been developed a range of tests and procedures for the characterisation of perforator performance. These tests and procedures have been developed by the industry via the American Petroleum Institute (API). In this regard, the API standard RP 19B (formerly RP 43 5 th Edition) currently available for download from www.api.org is used widely by the perforator community as indication of perforator performance. Manufacturers of perforators typically utilise this API standard marketing their products. The completion engineer is therefore able to select between products of different manufacturers for a perforator having the performance he believes is required for the particular job in hand. In making his selection, the engineer can be confident of the type of performance to expect from the perforator.
Nevertheless, despite the existence of these tests and procedures there is recognition that completion engineering remains at heart more art than science. It has been recognised by the inventors in respect of the invention set out herein, that the conservative nature of the current approach to completion has failed to bring about the change in the approach to completion engineering required to enhance and increase production from both straightforward and complex completions.
SUMMARY OF THE INVENTION
Thus, in accordance with a first aspect of the invention, there is provided a component for a shaped charge perforator, the component comprising a plastics material matrix having at least one non-explosive filler embedded therein.
The component may comprise either a shaped charge liner, a shaped charge case, or both.
Preferably, the non-explosive filler is distributed homogeneously throughout the matrix. However, a non-uniform distribution of filler may be employed where this brings about a particular effect in terms of size of hole and/or depth of penetration. Such tuning of the characteristics is achieved relatively straightforwardly through controlling the introduction of the filler during manufacture of the liner. In use, it may be found effective to tune a liner so at to suit a particular formation and the nature of the desired perforation. By utilising a plastics material matrix as a case, hitherto inaccessible volumes of rapid and large scale production may be opened up. Advantageously, the plastics material matrix may be selected to have frangible if not friable characteristics. Consequently, debris from the initiation of such a perforator may be rendered substantially harmless or at least less damaging than conventionally formed cases to structures surrounding the perforator. In addition, the debris will itself be inert inasmuch as it should not facilitate or otherwise cause corrosion in other downhole components of the completion.
The shaped charge case may be reinforced, for example either by means of means of a perform or by at least one of hand laying up, filament winding, compression moulding, and braiding, or by use of individual rovings.
In a further preferred embodiment filler volume is in the range 45% to 85% of the combined volume of filler and matrix, and most preferably in the range 45% to 65% of the combined volume of filler and matrix.
In a further preferred embodiment the filler comprises particles of substantially uniform size, and especially having particles size lies in the range 10-250 nm.
The filler may be a fibre, a flake, metallic or non-metallic.
In a further preferred embodiment the ratio of filler density to matrix density is substantially unity, the e filler having, for example, a density in the range between 0.5 gcm −3 and 5 gcm −3 .
According to a further aspect of the invention there is provided a shaped charge perforator comprising one or more components according to the first aspect of the present invention.
The shaped charge perforator may comprising a case, a liner, and a quantity of explosive packed between the case and the liner.
According to a further aspect of the invention there is provided a perforator gun comprising one or more shaped charge perforators according to the present invention.
According to a further aspect of the invention there is provided a compound for use in manufacture of components for shaped charge perforators under vacuum, the compound comprising a plastics material matrix having at least one non-explosive filler embedded therein and in which the filler volume comprises 45% to 85% of the combined volume of filler and matrix.
According to a further aspect of the invention there is provided a manufacturing method for a component for a shaped charge perforator, the method comprising compounding a matrix of plastic material with particulate filler under vacuum.
In preferred embodiments the component comprises at least one of a shaped charge liner and a shaped charge case.
In a further preferred embodiment the filler volume comprises 45% to 85% of the combined volume of filler and matrix.
In some embodiments the component comprises a first portion and a second portion, the first and second portions comprising different ratios of filler to matrix.
According to a further aspect of the invention there is provided a method of improving fluid outflow from a well borehole the method comprising perforating the borehole by means of a perforating gun according to the present invention.
Advantageously, subsequent recovery of fluids (e.g. hydrocarbons (oil or gas), water, or steam) from the well may be enhanced since use of liners and/or cases according to the present invention may provide improved penetration into the surrounding rock strata and/or mitigate the effects of debris left in the well shaft after penetration.
The fluid is typically one or more of hydrocarbons, water, and steam.
According to a further aspect of the invention there is provided a liner for a shaped charge perforator, the liner comprising a plastics material matrix having at least one non-explosive filler embedded therein, the filler being non-uniformly distributed throughout the liner whereby to tune the liner.
According to a further aspect of the invention there is provided a liner for a shaped charge perforator, the liner comprising a plastics material matrix having at least one non-explosive filler embedded therein, the liner being of non-uniform thickness whereby to tune the liner.
According to a further aspect of the invention there is provided a liner for a shaped charge perforator, the liner comprising a plastics material matrix having at least one non-explosive filler embedded therein, the filler being substantially density-matched to the plastics material.
Whilst in accordance with a yet further aspect of the invention, there is provided a manufacturing method for a shaped charge liner, the method comprising compounding a matrix of plastic material with particulate filler under vacuum. The liner may optionally include one or more of the following structures without limitation thereto, namely biconic or frills.
The various aspects of the invention may be combined both with each other and with their respective preferred features as would be apparent to the person skilled in the art.
BRIEF DESCRIPTION OF THE FIGURES
In order to assist in understanding the invention, a number of embodiments thereof will now be described, by way of example only and with reference to the accompanying drawings, in which:
FIG. 1 is a sectional view of a completion in which a perforator according to an embodiment of the invention may be used;
FIG. 2 is a scrap sectional view of a gun or carrier for one or more perforators of FIG. 1 ;
FIG. 3 is a cross-sectional view along a longitudinal axis of a perforator in accordance with an embodiment of the invention; and
FIG. 4 is a similar view of a further embodiment of a perforator in accordance with the invention.
DETAILED DESCRIPTION
In the following, any references to the term gun are intended to encompass the term carrier and vice versa.
With reference to FIG. 1 , there is shown a stage in the completion of a well 1 in which, the well bore 3 has been drilled into a pair of producing zones 5 , 7 in, respectively, unconsolidated and consolidated formations. A steel tubular or casing 9 is cemented within the bore 3 and in order to provide a flow path from the production zones 5 , 7 into the eventual annulus that will be formed between the casing 9 and production tubing (not shown) which will be present within the completed well, it is necessary to perforate the casing 9 . In order to form perforations in the casing 9 , a gun 11 is lowered into the casing on a wireline, slickline or coiled tubing 13 , as appropriate.
As is shown in more detail in FIG. 2 , the gun 11 is a generally hollow tube of steel in this are formed ports 15 through which perforator charges 17 are fired. The diameter of the gun 11 is selected to be a close but not interference fit with the casing 9 . Thus, the gun 11 is effectively self-centring within the casing 9 . By having the gun 11 self-centred within the casing 9 , there is little or minimal variation in the standoff distance between the charges 17 and the casing 9 . Any significant variation in the standoff distance may have a detrimental effect on the consistency of performance of the perforators.
In use, the gun 11 is lowered into the well 3 to a depth where it is adjacent the production zone 5 , 7 . It may be that the extent of the production zone 5 , 7 exceeds the length of a gun 11 in which case a string of guns (not shown) may be lowered and/or a number of operations may be required to fully perforate the casing in the region of each of the zones 5 , 7 . Furthermore, it may be that where the formation is relative unconsolidated, the perforators may be selected to form a larger aperture in the casing 9 at the expense of penetration into the formation 5 . Conversely, a small aperture may be formed in the casing 9 where greater penetration is required, such as, for example, in highly consolidated sediment 7 . In either case, the completion engineer will attempt to select the most appropriate charges for the particular perforations required in the casing 9 .
Turning to FIG. 3 , there is shown in more detail one embodiment of a perforator 17 for use with the abovementioned gun 11 . The perforator 17 is a shaped charge having a substantially cylindrical metallic case 19 and a liner 21 ′ according to the invention of conical form and having a wall thickness of 1% to 5% of the maximum diameter of the liner. The liner 2 is intended to fit snugly in one end of the cylindrical case 19 . The volume bounded by the inner surfaces 23 , 25 of the case and liner is filled with high explosive 27 . Typical high explosives suitable for filling the perforator 17 are RDX, HMX, PYX or HNS. As has been indicated, a number of such perforators 17 are loaded into the gun 11 . Each perforator 17 further includes a detonator 29 in contact with the high explosive 27 .
The case 19 provides impact and environmental protection for the explosive filing 27 as well as a containment mould when filling with explosive. In addition, during assembly, the case 19 assists in ensuring correct axial alignment of the liner 21 . The casing 19 is of conventional construction and as such is machined from steel selected to resist the tendency to fragment following detonation of the explosive 27 . It has been found that fragmentation of the case 19 can cause collateral damage to the structures surrounding the perforator 17 including the formation 5 , 7 and gun 11 . Furthermore, fragments of the case 19 can be carried by well fluids into valves and such like where they can lodge and/or initiate corrosion, particularly where zinc is used as a material in the composition from the case is fabricated.
In this embodiment, the liner 21 is formed from a reinforced polymeric material. Reinforcement is provided by a preform or in a variant of the embodiment using individual rovings.
The preform may be fabricated by hand lay up, filament winding, compression moulding or braiding using a binder to maintain the desired profile, to give just four examples. The selection of the most appropriate fabrication technique will, of course, depend to a large part on the scale and therefore economics of the perforator manufacture,
A matrix into which a solid material loading is added, can include one or more plastics material. The plastics material will be selected from types including, but not limited to one or more of the following, namely thermosets, thermoplastics and elastomers, It will be appreciated that the selection of a plastics material is, to a great part, made on the basis of its performance at the temperatures likely to obtain with a completion. In some circumstances, a gun 11 may remain within a casing 9 for extended periods before it is used. Thus the plastics material may need to be selected to withstand not only raised temperature, perhaps 200° C. but to maintain performance at elevated temperature for a significant period of days or even weeks.
It has been determined that of the class of thermoplastics, materials such as polystyrene, polymers of olefins containing 2 to 10 carbon atoms such as polyethylene and polypropylene are suitable for selection up to temperatures of around 200° C. Around and above this temperature, plastics material having higher meting points such as polyethersulfone (PES), polyoxymethylene (POM) and PK for example, can be utilised.
Into the matrix described above is added a non-explosive filler material. The loading may be up to 80% by volume. The filler material may include one or more preferably metallic materials. For example, a metallic material may be selected from the following non-exclusive list, namely copper, aluminium, iron, tungsten and alloys thereof. Additionally or alternatively, a non-metallic material or materials may be selected. Such materials include, but are not limited to inorganic or organic materials such as borides, carbides, oxides, nitrides of metals and glasses, especially refractory metals.
It has been found that quite unexpectedly the selection of low-density fillers is not necessarily detrimental to the performance of the perforator 17 . Lower density fillers are those having a density of 0.5 to around 5 g per cubic centimeter. By selecting appropriately, an approximate density match can be made between the filler and the matrix. It is thought that the approximate density match ensures that when the liner 21 is collapsed during the detonation of the high explosive 27 , the filler and matrix materials are less likely to separate from each other as the liner is accelerated into a jet by the explosive 27 . Furthermore, low density fillers having a density in the range of 1 to 5 g per cubic centimeter have the advantage that they lend greater bulk to the liner than higher density fillers for a given overall liner 21 weight. The filler may be a continuous or discontinuous material. By discontinuous material is meant a material whose properties vary in a piecewise constant fashion. Such materials can be modelled using a sub-structure approach. Alternatively, the variation in properties might be represented by an anisotropic elastic medium approximation.
The average particle or fibre diameter is in the range of around 10 nanometers to 250 microns. Above around 250 microns, in diameter, it has been found that coarse powders are more likely to separate out from the matrix during the formation of the perforator jet. Such separation results in reduced performance. At the other end of the range, it is seen that fine and ultrafine powders below about 2 microns in particle size are increasingly difficult to wet. As a result, such powders prove increasingly difficult to add to the matrix as their volume loading increases.
Although not apparent from the figure, it is possible during the formation of the lining 21 , to vary the distribution of the filler material or materials over the extent of the liner 21 . Such a variation in the loading permits the speed of sound within the liner 21 to be varied and thus allow the liner collapse mechanism to be tuned to suit a particular application. For example, in an unconsolidated formation, there is less need to form a so-called deep hole perforation. Rather there is a need to form a so-called big-hole perforation in the casing. The filler material may therefore be graded over the extent of the liner. Conversely, in a more consolidated formation, the creation of a deep hole perforation results in another graded distribution of filler material.
FIG. 4 shows a case 19 ′ for a shaped charge perforator 17 ′ in accordance with another embodiment of the invention. In this embodiment, the case 19 ′ is formed from a reinforced polymeric material. Reinforcement is provided by a preform or in a variant of the embodiment using individual rovings. The same reference numbers are used in the figure to represent elements common to the previously described embodiment. For example, a reinforced polymeric liner is shown as 21 .
The preform may be fabricated by hand lay up, filament winding, compression moulding or braiding using a binder to maintain the desired profile, to give just four examples. The selection of the most appropriate fabrication technique will, of course, depend to a large part on the scale and therefore economics of the perforator manufacture,
A matrix into which a solid material loading is added, can include one or more plastics material. The plastics material will be selected from types including, but not limited to one or more of the following, namely thermosets, thermoplastics and elastomers, It will be appreciated that the selection of a plastics material is, to a great part, made on the basis of its performance at the temperatures likely to obtain with a completion. In some circumstances, a gun 11 may remain within a casing 9 for extended periods before it is used. Thus the plastics material may need to be selected to withstand not only raised temperature, perhaps 200° C. but to maintain performance at elevated temperature for a significant period of days or even weeks.
It has been determined that of the class of thermoplastics, materials such as polystyrene, polymers of olefins containing 2 to 10 carbon atoms such as polyethylene and polypropylene are suitable for selection up to temperatures of around 200° C. Around and above this temperature, plastics material having higher meting points such as polyethersulfone (PES), polyoxymethylene (POM) and PK for example, can be utilised.
Into the matrix described above is added a non-explosive filler material. The loading may be up to 80% by volume. The filler material may include one or more preferably metallic materials. For example, a metallic material may be selected from the following non-exclusive list, namely copper, aluminium, iron, tungsten and alloys thereof. Additionally or alternatively, a non-metallic material or materials may be selected. Such materials include, but are not limited to inorganic or organic materials such as borides, carbides, oxides, nitrides of metals and glasses, especially refractory metals.
It has been found that unexpectedly loadings of up to 80% by volume result in a case of exceptional frangibility. Preferably, the volume loading of the filler within the matrix is in the approximate range of 45 to 80% and most preferably from 45% to 65%. It has also been found that higher volume loadings result in a mixture which can be too dry for practical use in injection moulding techniques.
The filler may be a continuous or discontinuous material. By discontinuous material is meant a material whose properties vary in a piecewise constant fashion. Such materials can be modelled using a sub-structure approach. Alternatively, the variation in properties might be represented by an anisotropic elastic medium approximation.
The average particle or fibre diameter is in the range of around 10 nanometers to 250 microns. It has been found that fine or ultrafine powders below about 2 microns in particle size are increasingly difficult to wet. As a result, such powders prove increasingly difficult to add to the matrix as their volume loading increases. Indeed as particle size rises above 250 microns, it seems a case is more likely to fragment in a manner detrimental to the condition of structures surrounding and included in the gun. It is believed that the reduced particle size and lower density of the particles or fibres result in less energy being transmitted to the surrounding structures and hence a lesser potential of collateral damage.
Although not shown in FIG. 4 , it is possible during the formation of the case 19 ′, to vary the distribution of the filler material or materials over the extent of the case. Such a variation in the loading permits the speed of sound within the case 19 ′ to be varied and thus allow the case fragmentation mechanism to be tuned to suit a particular application.
Whilst the case 19 ′ may be used with a conventional metallic liner, it has been found to be particularly effective to utilise the case with a reinforced polymeric liner 21 such as that set out in the preceding embodiment.
It will be appreciated by those skilled in the art that a manufacturing method suitable for the embodiment of a liner 21 described above is equally suited, with the necessary changes in terms of physical geometry and perhaps grading and type of loading, for the manufacture of a case 19 ′. Where a case 19 ′ and liner 21 of a perforator 17 are each formed from a reinforced polymeric material, then they may be manufactured as two separate elements, namely a liner 21 and a case 19 ′ as distinct manufacturing operations. Alternatively, the case 19 ′ and liner 21 may be formed in a single operation.
It should be further noted that where the case and liner are formed in a single operation, provision may need to be made to allow the introduction of the explosive.
It will be appreciated by those skilled in the art that what follows is a list of manufacturing techniques which is not intended to be exclusive. Thus, a matrix utilising a particulate reinforcement is formed by preparing a mixture of these two components and compounding them under vacuum. A case 19 ′ and/or liner 21 of compounded thermoplastic and particulate materials can be formed using injection or compression moulding. Injection moulding is believed to be particularly suitable for a case 19 ′ and/or liner 21 using a dry preform. Compression moulding is found to be effective for a case 19 ′ and/or liner 21 having a preform containing thermoplastic fibres co-mingled with the reinforcement.
Where the liner 21 and/or case 19 ′ is to be formed by filament winding, this has been found to give excellent strength and dimensional accuracy.
Finally, in a single operation moulding process where both case 19 ′ and liner 21 are formed together, it has been found effective to utilise dissolvable cores during the moulding process. Thus, it is possible to mould a waveshaper and initiation unit substantially contemporaneously with the case 19 ′ and liner 21 . Furthermore, by incorporating multiple injection ports into the tooling, it is possible to provide the grading of loading and indeed deliver different loadings into the case 19 ′ and/or liner 21 . Thus, it is possible to tune both the penetration characteristics of the liner and the frangibility characteristics of the case 19 ′ independently within a component formed during a single operation.
Furthermore, those skilled in the art will recognise that RIFT or RIM manufacturing techniques for example, may be employed as an alternative to injection moulding.
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A composite material case ( 19 ) and liner ( 21 ) is described for use in a perforator ( 17 ) for completing wells such as oil, gas and water wells ( 1 ). The materials selected are intended to exhibit stability during prolonged periods at the raised temperatures and pressures present in a well ( 1 ).
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FIELD OF THE INVENTION
[0001] The present invention relates to a device and a corresponding method for mechanically deforming cells.
BACKGROUND OF THE INVENTION
[0002] The past decade has seen substantial growth in research into how changes in the biochemical and biophysical properties of cells and subcellular structures influence and are influenced by the onset and progression of human diseases. It has been found in particular that the mechanical properties of cells are relevant for many diseases including cancer and coronary artery disease: diseases which cause large numbers of fatalities in the western world. According to the World Health Organization 7.6 million people worldwide died of cancer in 2005, while 8 million people in the US had a myocardial infarction. Other diseases that have been shown to influence the mechanical properties of the cell are malaria, cardiac myopathy, and muscular dystrophies.
[0003] The change in mechanical properties due to a disease can be significant. The elastic modulus of a cancerous cell can be an order of magnitude smaller than that of a healthy cell.
[0004] This indicates that the mechanical properties of cells in particular their stiffness is indeed a sensitive marker for the progression and/or presence even in the initial stages of a range of diseases. By measuring the cell stiffness it is in principle possible to detect single malignant cells and precancerous cells—malignantly transformed cells are easier to deform—and this opens for example the possibility to monitor the progress of cancer from pre-invasive to invasive. Similar arguments hold for the other diseases mentioned earlier.
[0005] Several approaches are being used to measure the mechanical properties of cells. Some of these techniques probe local deformation properties of the cell for example partial micropipette aspiration, cell indentation, and atomic force microscopy, while others probe the cell as a whole e.g. full micropipette aspiration, magnetic bead twisting, and cell compression testing. These measurement methods have various disadvantages.
[0006] First, for the local methods the response may depend significantly on the precise probing location and thus show a large cell-to-cell spread. Second, most methods are tedious and very time-consuming and are therefore not suitable for use in rapid clinical diagnosis. Third, other methods have the inherent risk of imposing damage to the cells (e.g. optical stretchers), leading to a faulty measurement. Finally, in many methods it is impossible to create a suitable environment around the cells to be tested leading to rather artificial and irrelevant results.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide a device and a corresponding method for mechanically deforming cells which avoid the above described disadvantages, and which preferably allow to monitor the mechanical properties of single cells but also of many cells simultaneously.
[0008] In a first aspect of the present invention a device for mechanically deforming cells is presented comprising
a cell holding element for holding a cell in a cell holding zone, a micro-actuator for applying a force on the held cell, wherein said micro-actuator can be electrically, thermally, photonically or magnetically actuated and wherein the micro-actuator applies said force on the cell in a non-actuated or an actuated state, and a stimulation unit for electrically, thermally, photonically or magnetically actuating said micro-actuator.
[0012] In a further aspect of the present invention a corresponding method is presented comprising the steps of
holding a cell in a cell holding zone, and electrically, thermally, photonically or magnetically actuating a micro-actuator for applying a force on the held cell, wherein said micro-actuator can be electrically, thermally, photonically or magnetically actuated and wherein the micro-actuator applies said force on the cell in a non-actuated or an actuated state.
[0015] Preferred embodiments of the invention are defined in the dependent claims. It shall be understood that the claimed device and the claimed method have similar and/or identical preferred embodiments as defined in the dependent claims.
[0016] The present invention is based on the idea to hold one (or more) cell(s) in one (or more) cell holding position(s) and to deform said one (or more) cells by applying a mechanical force by use of one (or more) micro-actuator(s), for instance to probe the mechanical properties of said cell(s). For this purpose different types of micro-actuators can be used, for instance polymer actuators, which have been described in WO 2006/087655 A1 and WO 2008/020374 A2 for manipulation (transportation, mixing, routing) of fluids in micro-fluidic devices.
[0017] According to a preferred embodiment, the micro-actuator has the form of a stripe which is curled in one of non-actuated or actuated state and non-curled in the other state as for instance disclosed in the above mentioned prior art documents. In one embodiment the force is applied to the cell when the micro-actuator is actuated from the curled state into the rolled out state whereas in another embodiment the force is applied to the cell when the micro-actuator is released from the actuated (rolled out) state into the curled state. In further embodiments the micro-actuator can also be adapted such that the curled state is the actuated state and that the rolled out state is the non-actuated state.
[0018] According to a further embodiment the micro-actuator comprises a double-layer including a polymer film layer in particular an acrylate film and an electrically conductive film layer and the stimulation unit comprises a stimulation electrode and a voltage source for applying a voltage between said stimulation electrode and said conductive film layer. In particular a polymer MEMS (micro-electro-mechanical system) actuator (PMA) as described in WO 2008/020374 A2 is employed according to this embodiment which is easily to control by application of a voltage, e.g. a high AC voltage.
[0019] According to an alternative embodiment the micro-actuator comprises a magnetic material and the stimulation unit comprises a magnetic field unit for generating a magnetic field through said cell holding zone. In this embodiment the micro-actuator preferably comprises a composite structure, in particular a polymer film with dispersed magnetic particles or a stack of non-magnetic and a magnetic films. The advantage of magnetic stimulation and detection over electrical stimulation and detection is that the magnetic field exhibits less interaction with biological materials present in the device. Therefore, electrochemical effects such as electrolysis are avoided easily and the detection is less influenced by background noise.
[0020] To enable a monitoring of the mechanical properties of cells a sensing element is provided adjacent to said cell holding zone for sensing the deformation of the cell when a force is applied to the cell by said micro-actuator. Thus the deformation (in particular the amount, location, duration, etc. thereof) of the cell induced by the force applied by the micro-actuator and hindered by the stiffness of the cell is detected allowing to get significant information about the cell.
[0021] According to a preferred embodiment the sensing element is an optical magnetic or electric sensing element in particular a camera, a GMR sensor or a sensing electrode. Thus different options exist for detection of the deformation. Optical sensing has the advantage of being a straight-forward commonly used approach for cell imaging. Electrical sensing has the advantage of enabling integration in the device.
[0022] Still further sensing element preferably comprises a sensing electrode and a capacitance measuring element for measuring the capacity between said sensing electrode and said conductive film layer of said micro-actuator. In particular in embodiments using electrostatic actuation the capacitance measurement is preferred the capacitance being a measure for the distance between the sensing electrode and the actuator electrode (conductive film layer of the actuator).
[0023] A further application of the device and method of the present invention is the lysing of cells. For this purpose according to an embodiment the stimulation unit is adapted for applying a stimulation signal, which is so large that the micro-actuator applies a force on the cell causing the cell to lyse. This provides a simple and effective possibility of lysing cells.
[0024] To avoid that the cell is pushed away from the cell holding position by the application of force from a single actuator, it is proposed according to a further embodiment that two or more micro-actuators are arranged on different sides of the cell holding element for applying a force on the same cell from different directions.
[0025] In a further embodiment an array of micro-actuators and associated cell holding elements are provided for simultaneously deforming a number of cells. In this way statistics of the mechanical properties of a large number of cells can be obtained quickly. For this purpose, an LTPS (low temperature polycrystalline Si) platform, as for instance described in WO 2008/020374 A2, can be used, according to which a number of micro-actuators is arranged in a two-dimensional matrix array.
[0026] Preferably the invention is used a micro-fluidic system and comprises a micro-fluidic chamber including said micro-actuator, said cell holding element, said stimulation unit and a buffer solution, in particular a sugar solution, containing the cells. Such micro-fluidic systems are in general also described in WO 2006/087655 A1 and WO 2008/020374 A2.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. In the following drawings:
[0028] FIG. 1 a - 1 e shows various embodiments of a micro-actuator used according to the present invention,
[0029] FIG. 2 shows the general layout of an embodiment of the device according to the present invention,
[0030] FIG. 3 a - 3 b shows a first embodiment of a device according to the present invention,
[0031] FIG. 4 a - 4 b shows a second embodiment of a device according to the present invention,
[0032] FIG. 5 shows a third embodiment of a device according to the present invention, and
[0033] FIG. 6 shows the general layout of an array of micro-actuators.
DETAILED DESCRIPTION OF THE INVENTION
[0034] FIG. 1 shows a number of embodiments of a micro-actuator. FIG. 1 a shows a double layer composite structure of a micro-actuator 1 comprising a polymer film 2 (e.g. an acrylate) and an electrically conductive film 3 (e.g. chromium). The processing is tuned such that the structure curls upward being attached at one end. When a voltage difference is applied between an electrode 4 , placed underneath the actuator 1 and insulated from the conductive film 3 by another insulating layer 5 (e.g. an acrylate layer) and the conductive film 3 , an electrostatic force will pull the actuator 1 towards the substrate 6 . Consequently, it will roll out and flatten out on the substrate 6 . When the voltage is removed the slab will return to its original curled shape by elastic recovery. The actuation effect is bi-stable and the position of the actuator tip is a function of the applied voltage. For a particular PMA design the “unroll” voltage Vun is 11 V, and the “elastic recovery” voltage Ver is 5V. These values can be tuned typically between 1V and 100V depending on the dimensions and mechanical properties of the actuator 1 . FIG. 1 b shows a SEM picture of actual structures made in this case with a length of 100 μm, a width of 20 μm, and a thickness of 1 μm. Such an embodiment of an actuator is described in more detail in WO 2008/020374 A2 (cf. FIG. 1 ).
[0035] Many alternatives to the geometry shown in FIGS. 1 a and 1 b are conceivable. Instead of curled strips they may be straight beams, cylindrical rods, and so forth. The initial orientation of the strips 7 , 8 may be parallel (strips 7 ) or perpendicular (strips 8 ) to the surface, as illustrated in FIG. 1 c.
[0036] Further “stimuli” other than electrical field may be used to actuate the structures. A magnetically stimulated actuator 9 having an actuator strip 10 is depicted in FIG. 1 d . The actuator strip 10 consists of a composite material, of which one component is magnetic. One example is a polymer film with dispersed magnetic particles. The latter may be paramagnetic or ferromagnetic. Another example is a structure consisting of a stack of non-magnetic (e.g. polymer) and a magnetic (e.g. nickel) films. Such a magnetic actuator can be set into motion by magnetic field that is generated by external means, such as (a combination of) coils, or by integrated current wires or coils, as is illustrated in FIG. 1 d where a current wire 11 indices a magnetic field near the strip 10 , which then moves due to the magnetic force acting upon it. Such an embodiment of an actuator is described in more detail in WO 2006/087655 A1 (cf. FIG. 13 ).
[0037] Even other possibilities are actuators responding to light or temperature. Several polymeric materials that respond to a change in temperature by deforming are known. An overview and some background can be found in Broer et al. [Dirk J. Broer, Henk van Houten, Martin Ouwerkerk, Jaap M. J. den Toonder, Paul van der Sluis, Stephen I. Klink, Rifat A. M. Hikmet, Ruud Balkenende. Smart Materials. Chapter 4 in True Visions: Tales on the Realization of Ambient Intelligence, ed. by Emile Aarts and José Encarnaçao, Springer Verlag, 2005.] For example by incorporating LC (liquid crystalline) material into an elastomeric network a material can be made which upon heating through a specific temperature (the nematic isotropic temperature) undergoes a transition in the backbone of the elastomer molecules and changes length. By careful control of processing conditions [D. J. Broer et al, accepted for pub. in Adv. Funct. Mater., (2005)] it is possible to obtain a gradient in orientation of LC molecules over the thickness of the film so that one side of the film contracts while the other expands. This creates a reversible rolling up of the film at a specific temperature. FIG. 1 e shows cross-sectional photos of such a film at various temperatures.
[0038] Light-actuation or photonic addressing can be achieved using photoresponsive materials, containing chromophores, leading to photochromism. Photochromism is defined as a reversible phototransformation of a chemical species between two forms with different absorption spectra. During the photoisomerisation, also other properties may change, such as the refractive index, dielectric constant and geometrical structure. Particular non-limitative examples of these materials include azobenzenes, spirobenzopyranes, stilbenes, α-hydrazono-β-ketoesters, and cinnamates.
[0039] The polymer-based actuators can be integrated in a micro-fluidic system, for example covering the floor of a micro-fluidic chamber or channel in an arrayed arrangement. In the case of electrostatic, magnetic, or temperature-actuation, the electrode pattern can be designed and manufactured such that the micro-actuators or groups of them can be addressed individually.
[0040] According to an application of the present invention a single micro-actuator or an array of micro-actuators is integrated in micro-fluidic systems to measure the mechanical properties in particular the stiffness of biological cells (e.g. for diagnostic analysis). The key is to trap/tether the cells on top of the micro-actuator(s) or between them apply a force on the cells through actuating the micro-actuator(s), and detecting the deformation of the micro-actuator(s), which will be induced by the stimulus such as electrical field or magnetic field but hindered by the stiffness of the attached/contacting cell. The general layout of an embodiment 20 of the device according to the present invention is as shown in FIG. 2 . The cells 21 , suspended in a buffer liquid 22 , are supplied through a supply channel 23 into a diagnostic chamber 24 . The chamber 24 contains cell trapping sites and corresponding polymer actuators (both not shown in FIG. 2 ). The cells 21 are deformed using the actuators, while the level of deformation is sensed. In such a diagnostic chamber 24 using an array of micro-actuators many cells 21 can be tested simultaneously.
[0041] In the following a number of particular embodiments will be shown and explained to illustrate the present invention in more detail.
[0042] One main application of the present invention is cell stiffness measurement using cell squeezing by actuated micro-actuators. A first embodiment of a device 30 for such an application is shown in FIG. 3 . This embodiment comprises two micro-actuators 31 for separately deforming a single cell 32 , which is held in a cell holding position by a cell holding element 33 . Below the cell holding elements 33 sensing units 34 , e.g. sensing electrodes 34 , are provided for measuring the deformation of the cell 32 above it when a force is applied to the cell 32 by the respective micro-actuator 31 . Further, an actuating electrode 35 is provided below each of the micro-actuators 31 , which is insulated from the (conductive) micro-actuator 31 by an insulating layer 36 . All elements are provided on a substrate 37 .
[0043] The micro-actuators 31 are similar to those shown in FIGS. 1 a , 1 b . They could be electrostatically actuated or magnetically actuated structures. In the non-actuated state shown in FIG. 3 a , they are curled away (upwards) from the substrate 37 . The cells 32 are trapped between the actuators 31 , on the cell adhesion spots by the cell holding elements, which are, for example, formed by cell adhesion proteins (integrins). Alternatively, tissue adhesives such as BD Cell-Tak™ can be placed at the cell holding positions as cell holding elements 33 .
[0044] The size and spacing of the actuators 31 should be tuned to the cell size. Since a typical biological cell size is 10 to 20 μm, the size and spacing of the actuators 31 should be several tens of μm, which is easily achievable with the current technology.
[0045] Preferably a high frequency AC voltage is applied to the actuating electrodes 35 to roll-out the flap of the micro-actuators 31 , as shown in FIG. 3 b . The same signal can also be used for probing the impedance of the overlying flap and therefore used to sense the position of the flap and deduce the presence, and eventual size, of a trapped cell 32 .
[0046] The cell 34 should be situated directly on top of the sense electrode 34 , and there should preferably be a gap in the insulator 36 so that the actuating electrodes 35 , makes direct contact with the medium in which the cells 32 are situated. This concentrates the field lines through the cells 32 and increases the sensitivity of the electrical measurement.
[0047] In a slightly modified embodiment, the size of the micro-actuators is such that it is possible to have multiple sense electrodes 34 under each flap.
[0048] When actuated, the micro-actuators 31 are attracted towards the substrate 37 and the cells 32 are “squeezed”. The resulting deformation of the cell 32 and the corresponding shape change of the actuators 31 , is determined by the cell stiffness. The deformation may be observed in various ways:
[0049] i) optically, e.g. by direct imaging with a CCD
[0050] ii) magnetically: if the actuators 31 are magnetic, a magnetic detector (as sensing element 34 ) integrated in the substrate 37 , e.g. a GMR sensor, can detect the movement and global shape of the actuator 31 ;
[0051] iii) from capacitance measurements (in particular for electrostatic actuation): the capacitance between the electrode integrated in the actuator 31 and actuating electrode 35 integrated in the substrate 37 depends on the distance between them; measurement of this capacitance, hence, gives information about the extent of squeezing of the cell 31 . In practice it will probably be most interesting to first apply a voltage to induce actuator roll-out. The capacitance immediately after roll-out is a measure of the volume of the cell 31 trapped under the flap. The voltage and therefore the force applied can then be ramped and the capacitance measured. This gives a deformation as a function of force curve.
[0052] The forces that would be necessary to deform the cell significantly are in the order of 1 nN, and these values can be easily reached with the proposed electrostatic or magnetic actuators.
[0053] An alternative embodiment of a device 40 according to the present invention is shown in FIG. 4 . In this embodiment two micro-actuators 31 a , 31 b are provided per cell holding position located on opposite sides of the cell holding element 33 . FIG. 4 a again shows the non-actuated state, FIG. 4 b shows the actuated state. As can be seen from FIG. 4 b the cell 32 is squeezed from two sides, decreasing the possibility that it is pushed away from the cell adhesion spot instead of being deformed. It shall be noted that, of course, also more than two micro-actuators 31 a , 31 b can be positioned around single cell adhesion spot to further increase this advantage.
[0054] In a further embodiment an electrically active substrate is used. Then it is also possible to design electrode geometries on the substrate which locate the cell at the required location. This can be in the form of a hole in the actuating electrode or any low E-field trap and can be used for either holding the cell or for manipulating it into the correct location for binding with the integrins.
[0055] The holding mechanism for the cell can also be of a microfluidic origin where a small hole is created between two volumes. A pressure difference between the volumes will suck the cells into the hole and hold the cell for probing.
[0056] For actuating it is proposed in an embodiment to place the cells in a sugar (sucrose or mannitol) water buffer solution. This medium has a low electrical conductivity and therefore prevents any ionic shielding of the electrical fields.
[0057] Another main application of the present invention is clean mechanical lysing. If the cell is firmly held on the adhesion spot, then the actuating voltage can be intentionally set very high. This results in the flap being actuated with an enormous force and can result in the lysing of the trapped cell. This is interesting as the cell membrane is thereafter bound to the substrate while the contents of the cell are free to diffuse into the solution. This is desirable for single cell PCR (Polymerase Chain Reaction) or for any integrated bio device where downstream DNA extraction has to be performed.
[0058] The invention can also be used with magnetic actuation and detection. As shown in FIG. 1 d current wires are integrated in the substrate. Running a current through them generates a concentric magnetic field that attracts the actuators toward the surface.
[0059] Another possibility is to place electromagnets or magnetic coils around the device, for example four magnetic coils 51 - 54 in a symmetric layout of a microfluidic device 50 illustrated in FIG. 5 . The magnetic coils 51 - 54 can be individually addressed. It will be possible to generate a magnetic field that changes in time and in magnitude, by which the actuators 55 (polymer micro actuators) are stimulated.
[0060] The general layout of an array of micro-actuators is shown in FIG. 6 . The array of electrodes 3 , 4 of the micro-actuators 1 can be connected to external voltage drivers 60 , 61 . In order to realize this passive matrix layout, it is necessary that both the actuation and foil electrodes are structured in the form of lines orientated at an angle to each other. In the example of FIG. 6 , the actuation electrodes have been structured in the form of columns, whilst the foil electrodes 3 have been structured in the form of rows. In order for a passive matrix system to operate successfully, it is required that the micro-actuator 1 exhibits a voltage threshold. A voltage of around Vur is required to unroll the foil 3 , whereby a voltage of around Vt will be insufficient to initiate the unrolling.
[0061] Each row and each column can be individually attached to a voltage source. For example, the row electrodes (foil electrodes 3 ) may be connected to a select driver 61 , e.g. a standard-shift register similar to a gate driver for an AMLCD, which can switch between 0V and Vt. The column electrodes (actuator electrodes 4 ) are then connected to the actuation driver 60 . The actuation driver 60 could be just a standard voltage data driver as used for e.g. passive or active matrix liquid crystal displays (LCD), with outputs which may have either 0V or (Vur−Vt) levels.
[0062] The operation of this array and further embodiments of arrays of micro-actuators which can generally be employed according to the present invention are shown in FIGS. 2-6 of WO 2008/020374 A2, the description of which being incorporated herein by reference.
[0063] Thus, according to the present invention it is possible to obtain statistics of the cell property measured since the signal can be read out per individual actuator. The use of an LTPS platform as described for instance in WO 2008/020374 A2 enables this. Alternatively the actuators could also be grouped together to give one average figure for the population.
[0064] Further, the actuation can be done in a dynamic time-varying way to probe time-dependent mechanical properties of cells. The method can also be combined with a cell sorting method. Still further, the “environment” (chemical, temperature) of the cell can be controlled to create either special or optimal conditions.
[0065] There are different fields of application of the invention:
Mechanical characterization of cells in general; Mechanical lysis of cells; Diagnostic micro-fluidic device for cancer, malaria, cardiac myopathy, muscular dystrophies or other diseases that affect the cell's mechanical properties: detection of presence or progression of these diseases; Screening large amounts of cells for affected cells e.g. when trying to find a few cancer cells among many normal cells; Screening for the effect of pharmaceuticals. (Simultaneous) Measurement of mechanical properties of (many) cells using micro-actuators integrated in a micro-fluidic system; the method enables to obtain statistics of the property of interest since the read-out can be done in principle per actuator, e.g. using an LTPS platform; A medical diagnostic device on the basis of this principle; Electrostatic/magnetic/optical/thermal actuation in combination with electrostatic/magnetic/optical detection.
[0074] In conclusion an aim of the present invention is to provide a device and a method to determine the mechanical properties of biological cells by deforming them using micro-actuators integrated in a micro-fluidic device. The method is such that many cells may be analyzed simultaneously. Since the mechanical properties of cells are relevant for many diseases including cancer and coronary artery disease the proposed micro-fluidic device may be used as a fast and sensitive diagnostic tool for detecting the presence or progression of these diseases. Further, lysing of cells is possible.
[0075] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.
[0076] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.
[0077] Any reference signs in the claims should not be construed as limiting the scope.
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The present invention relates to a device for mechanically deforming cells comprising: a cell holding element ( 33 ) for holding a cell ( 32 ) in a cell holding zone, a micro-actuator ( 31 ) for applying a force on the held cell ( 32 ), wherein said micro-actuator ( 31 ) can be electrically, thermally, photonically or magnetically actuated and wherein the micro-actuator ( 31 ) applies said force on the cell ( 32 ) in a non-actuated or an actuated state, and a stimulation unit ( 35 ) for electrically, thermally, photonically or magnetically actuating said micro-actuator ( 31 ).
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a 371 National Stage Application of PCT/EP2012/003450, filed Aug. 13, 2012. This application claims the benefit of European Application No. 11007232.9, filed Sep. 6, 2011, which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a device and a system for reading out X-ray information stored in storage phosphor plates as well as a storage phosphor plate.
[0004] 2. Description of the Related Art
[0005] The storing of X-rays penetrating an object, for example a patient, as a latent image in a so-called storage phosphor plate constitutes an option for recording X-ray images. In order to read out the latent image, the storage phosphor plate is irradiated with stimulating light and thereby stimulated to emit emission light. The emission light, the intensity of which corresponds to the image stored in the storage phosphor plate, is detected by an optical detector and converted into electrical signals. The electrical signals are further processed, as required, and finally made available for analysis, in particular for medical-diagnostic purposes, by providing them on a corresponding output device, such as for example a monitor and/or a printer.
[0006] In prior art devices and systems, storage phosphor plates are mostly transported relative to the read-out device by pairs of rotating rollers.
SUMMARY OF THE INVENTION
[0007] The problem addressed by preferred embodiments of the present invention is to provide a device and a system for reading out X-ray information stored in storage phosphor plates as well as a corresponding storage phosphor plate, the device and system assuring a transport of the storage phosphor plate that is as reliable as possible, while providing a straightforward structure.
[0008] Preferred embodiments of the present invention provide a device, a system and the storage phosphor plate as described below.
[0009] The device according to a preferred embodiment of the present invention comprises a read-out device for irradiating the storage phosphor plate with stimulating light and for detecting emission light which is thereby stimulated in the storage phosphor plate as well as a transport device for transporting the storage phosphor plate comprising at least one roller that can be put into rotation about its rotational axis, and is characterized in that one or more magnets are arranged inside the roller which has the form of a hollow body, in particular a hollow cylinder.
[0010] Apart from the device according to a preferred embodiment of the present invention, the system according to a preferred embodiment of the present invention comprises a storage phosphor plate comprising a base layer and a storage phosphor layer located on the base layer, at least one partial area of the base layer of the storage phosphor plate being ferromagnetic.
[0011] The storage phosphor plate according to a preferred embodiment of the present invention comprises a base layer and a storage phosphor layer located on the base layer and is characterized in that the base layer of the storage phosphor plate comprises a ferromagnetic layer and two non-ferromagnetic layers, in particular two plastic layers, the ferromagnetic layer being arranged between both non-ferromagnetic layers.
[0012] Preferred embodiments of the present invention are based on the thought of providing a hollow roller for transporting the storage phosphor plate, whereby one or more magnets are arranged inside the hollow roller in such a way that during a rotation of the roller they maintain a predetermined spatial position and in particular do not follow the rotational movement of the roller. The hollow roller body itself is hereby not magnetic, in particular not ferromagnetic. A storage phosphor plate which is made magnetic and/or ferromagnetic at least in partial areas is attracted towards the hollow roller body by magnetic forces by the magnets arranged inside the hollow roller body in such a way that the frictional forces which occur when the storage phosphor plate comes into contact with the hollow roller body are considerably increased compared to a roller with no additional magnets arranged in its inside. During a rotation of the roller the transport of the storage phosphor plate contacting the roller is assured with a reliability which is correspondingly increased. Compared to a transport device in which the storage phosphor plate is clamped between two rotating rollers in order to be transported in a reliable way by these rollers, a second roller may be omitted in the present case.
[0013] Overall, preferred embodiments of the present invention provide the advantage of combining a straightforward structure and a reliable plate transport.
[0014] In a preferred embodiment of the present invention, inside the roller a support is provided which extends in the direction of the rotational axis of the roller and at which the magnets are arranged. This configuration allows for an easy and reliable mounting of the magnets inside the roller.
[0015] Preferably, the support is rotatably mounted about a longitudinal axis which runs substantially parallel to the rotational axis of the roller or coincides with the rotational axis of the roller. This has the effect that the support and the magnets, respectively, can be rotated independently from the hollow roller body.
[0016] Preferably, the rotational position of the support hereby allows to select an area at the outside circumference of the roller in which a magnetic field occurs which is larger than the remaining outside circumference of the roller so that a ferromagnetic body, in particular a storage phosphor plate, is attracted by the roller when contacting the area on the outside circumference of the roller. The respective rotational position of the support thus allows selecting the area on the outside circumference of the roller at which the frictional forces are at their greatest during a contact between the storage phosphor plate and the roller. The selection of the rotational position of the support or the magnets, respectively, allows adjusting in a simple and precise manner when the storage phosphor plate is transported when contacting the rotating roller (the magnets are as closely as possible to the contact position) or not (the magnets are as remote as possible from the contact position).
[0017] Moreover, it is preferred that the support has the form of a bar, in particular with a rectangular or square cross-section. This allows implementing the above-described functionalities of the support in a simple and reliable way.
[0018] Preferably, the support or at least a section of the support is made ferromagnetic. For example, the support or a section of the support is composed of iron or a ferromagnetic iron alloy. As the magnetic attraction forces between the magnets and the support hereby already ensure the fixation of the magnets to the support, no further fixing devices, e.g. adhesive, clamps, screws or rivets, are needed. However, additional fixing devices can be provided in order to assure a secure fixation.
[0019] Preferably, the magnets are arranged in a lateral area of the support which in particular extends parallel to the rotational axis of the roller. This allows realizing the arrangement of the magnets inside the hollow roller body as well as the selection of the respective position of the magnets in a particularly simple and reliable manner.
[0020] The magnets arranged inside the roller can have the form, for example, of electromagnets. Electromagnets hereby have the advantage that their magnetic fields can be switched on and off, respectively, as and when required. Preferably, however, the magnets used are permanent magnets so that additional provisions, such as, for example, the power cables required in case of electromagnets, can be omitted, which simplifies the construction further.
[0021] In a preferred embodiment, the roller having the form of a hollow body is composed of a non-ferromagnetic material, in particular aluminum. A non-ferromagnetic material in the context of the present invention hereby is a diamagnetic or paramagnetic material having a relative magnetic permeability close to the value 1, in particular between about 0.99 and 1.01, that is able to weaken or amplify, respectively, a magnetic field only slightly. This assures high magnetic flow densities in the area of the roller jacket and hence high frictional forces in the contact area between the storage phosphor plate and the roller, thus assuring a reliable transport.
[0022] A further advantageous development provides that the outer circumferential area of the roller is provided with a friction-enhancing coating, in particular made of rubber or plastic. This allows a further amplification of the frictional forces between the storage phosphor plate and the roller that are already increased by the magnetic attraction forces, which in turn further enhances the reliability of the transport of the storage phosphor plate.
[0023] In a further preferred embodiment of the present invention, the transport device comprises a removal unit which can be coupled to the storage phosphor plate and which is ferromagnetic in at least a partial area so that the removal unit, optionally together with the storage phosphor plate coupled thereto, can be transported by the rotating roller when contacting it. Preferably, the removal unit is designed for removing and/or returning the storage phosphor plate located in an initial position, in particular in a cassette, respectively from and into the initial position. The removal unit that is ferromagnetic at least in partial areas and the roller are arranged in such a way that they are able to come into contact with each other and the removal unit can be transported by the rotating roller. Hence, the roller can indirectly—i.e. through the removal unit—also remove and/or return the storage phosphor plate respectively from and into the initial position, in particular a cassette, without requiring a further drive for the removal unit.
[0024] Alternatively or additionally, the transport device is designed for transporting the storage phosphor plate relative to the read-out-device, in particular past the read-out device. Preferably, the roller is hereby arranged close to, in particular below, the read-out device so that, wherever possible, the complete storage phosphor plate can pass through the read-out device and be read out by it. This allows omitting additional drive or transport devices for transporting the plate past the read-out device. A positioning of the roller below the read-out device, in particular below a line described by the deflected stimulating light beam, has the additional advantage that the storage phosphor plate supported by the roller shows a high degree of evenness, which allows a particularly reliable read-out of the X-ray information stored in the storage phosphor plate.
[0025] In a preferred embodiment of the storage phosphor plate, the ferromagnetic layer, in particular in its edge portion, is provided with at least one additional ferromagnetic area. As a result, the magnetic attraction forces occurring during a magnetic coupling between the transport device, in particular the removal unit, and the storage phosphor plate in the proximity of the ferromagnetic area, in particular in the edge portion of the ferromagnetic layer, are particularly strong. This makes the removal, the transport and the return, respectively, of the storage phosphor plate particularly reliable.
[0026] The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 a schematic representation of a device for reading out storage phosphor plates.
[0028] FIG. 2 a perspective representation of an example of a roller with a support provided on its inside and an enlarged cut-out view from the support.
[0029] FIG. 3 a cross-sectional view through a roller with a support provided on its inside at two different rotational positions of the support.
[0030] FIG. 4 a cross-sectional view of a first example of a storage phosphor plate.
[0031] FIG. 5 a cross-sectional view of a second example of a storage phosphor plate.
[0032] FIG. 6 a cross-sectional view of a removal unit.
[0033] FIGS. 7 a to 7 d are perspective representations (left part) and a cross-sectional representation (right part) of a transport device in different phases during the removal of a storage phosphor plate from a cassette.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] FIG. 1 shows a read-out device for reading out a storage phosphor plate 1 . A laser 2 generates a stimulating light beam 3 that is deflected by a deflection element 4 in such a way that the stimulating light beam moves along a line 8 across the storage phosphor plate 1 to be read out. The deflection element 4 has a reflecting area, in particular in the form of a mirror, that is made to move oscillatingly by a drive device 5 . Alternatively, the deflection element 4 can have a polygon mirror that is made to move rotationally by the drive device 5 , in this case a motor, and deflects the stimulating light beam 3 across the storage phosphor plate 1 .
[0035] During the movement of the deflected stimulating light beam 3 ′ across the storage phosphor plate 1 , the storage phosphor plate emits emission light depending on the X-ray information stored therein, which emission light is collected by an optical collection device 6 , for example an optical fiber bundle or a suitable mirror device, and detected by an optical detector 7 , preferably a photomultiplier (PMT), and is thereby converted into a corresponding detector signal S.
[0036] The detector signal S is supplied to a device 9 , in which digital image signal values B for individual pixels of the read out X-ray image are derived.
[0037] The transport of the storage phosphor plate 1 in the transport direction T by a transport device has the effect that individual lines 8 of the storage phosphor plate 1 are successively read out, and a two-dimensional composite X-ray image is thereby obtained that is composed of individual pixels with respectively one associated image signal value B.
[0038] In the example shown, the transport device comprises a roller 10 that is put into rotation about a rotational axis 11 by a roller drive (not shown). The storage phosphor plate 1 is supported, with its underside, by the roller 10 and is transported in direction T by the rotation of the roller 10 as a result of the frictional engagement occurring hereby.
[0039] In the example shown, the frictional forces that hereby occur between the storage phosphor plate 1 and the roller 10 are substantially increased by the fact that the storage phosphor plate 1 which is permanently magnetic or ferromagnetic at least in partial areas, is attracted towards roller 10 by magnetic forces. The magnetic fields required hereby are generated by one or more permanent magnets 14 which are arranged on a support 12 which extends inside the roller 10 . The roller 10 and the support 12 are hereby mounted or arranged in such a way that the rotational position of the support 12 remains unchanged when roller 10 rotates about its rotational axis 11 in the rotation direction indicated by an arrow. As a result, the magnetic field generated by the permanent magnet(s) 14 is at its largest in the upper part of the roller 10 which supports the storage phosphor plate 1 . In this part, the frictional forces between the storage phosphor plate 1 and the roller 10 are significantly increased, which allows a reliable transport of the storage phosphor plate in transport direction T.
[0040] FIG. 2 shows an example of a roller 10 with a support provided inside the roller 10 , whereby FIG. 2 only shows the bearing portions 13 of the support (upper part of the Figure), as well as an enlarged cut-out view from the support 12 (lower part of the Figure), in each case in a perspective representation.
[0041] Roller 10 preferably is a hollow body, for example a tube, made from a non-ferromagnetic material, for example aluminum or plastic. Preferably, the outer circumference of the roller 10 is configured in such a way that the frictional forces occurring when the storage phosphor plate 1 comes into contact with the roller 10 are as strong as possible. This is achieved, for example, by using a rubber coating or a plastic coating. The roller 10 is rotatably mounted in the device by bearings (not shown) and is put into rotation by a suitable roller drive.
[0042] Both ends of the support 12 which is provided inside the roller 10 are provided with a bearing section 13 which ensures the mounting of the support 12 in the device. Preferably, the support 12 is hereby rotatably mounted about its longitudinal axis, whereby the selection of the respective rotational position of the support 12 allows defining in which circumferential area of the roller 10 the magnetic attraction forces are at their largest. Preferably, the rotational axis of the support 12 and the rotational axis 11 of the roller 10 run coaxially, i.e. both axes coincide. Alternatively, it can be provided that the rotational axis of the support 12 runs parallel to the rotational axis 11 of the roller 10 .
[0043] In the example shown, the support 12 comprises a bar-like section with a square cross-section, whereby several permanent magnets 14 are arranged along a side of the bar-like section. Preferably, the bar-like section of the support 12 is ferromagnetic so that magnetic attraction forces already assure a reliable adhesion of the permanent magnets 14 to the support 12 . Additionally or—in case the bar-like section of the support 12 is not ferromagnetic—alternatively, the permanent magnets 14 can also be fixed to the support 12 by a suitable adhesive or other fixing device.
[0044] FIG. 3 shows a cross-section through a roller 10 with a support 12 located on its inside at two different rotational positions of the support 12 .
[0045] In the rotational position of the support 12 as shown in the upper part of the Figure, the magnetic field generated by the magnets 14 is at its largest in an upper circumferential part B1 which runs parallel to the rotational axis 11 of the roller 10 . A storage phosphor plate supported by area B1 (see FIG. 1 ) and having ferromagnetic properties is then attracted towards roller 10 by high magnetic forces—additionally to gravity.
[0046] On the other hand, in the case of the rotational position of the support 12 as shown in the lower part of the Figure, the magnetic field is at its largest in a circumferential area B2 along the roller 10 which is displaced by about 45°. Accordingly, for this rotational position, the magnetic field is substantially smaller in the upper circumferential part compared to the rotational position as shown in the upper part of the Figure. As a result, in the case of this rotational position, the magnetic attraction forces and thus the frictional forces between a storage phosphor plate 1 supported by area B1 and the roller 10 are correspondingly smaller.
[0047] This means that the selection of the rotational position of the support 12 and the magnets 14 located thereon allows adjusting precisely when, for example, a storage phosphor plate 1 supported by the upper circumferential area B1 of the roller 10 will be transported during a rotation of the roller 10 (upper part of the Figure) or has to be released by the roller 10 (lower part of the Figure), for example during a return of the storage phosphor plate 1 in a cassette provided.
[0048] FIG. 4 shows a cross-section of a first example of a storage phosphor plate 1 comprising a storage phosphor layer la that has been applied to a base layer. In the example shown, the base layer comprises a ferromagnetic layer ld that is surrounded by two non-ferromagnetic layers 1 b and 1 c.
[0049] The ferromagnetic layer 1 d preferably is a steel sheet having a thickness between approximately 0.01 mm and 0.1 mm, preferably of approximately 0.05 mm. Both non-ferromagnetic layers 1 b and 1 c preferably are plastic sheets. Preference is hereby given to polyester foils that allow achieving a particularly good frictional engagement between the underside of the storage phosphor plate 1 and the roller 10 . This particularly applies if the outer circumference of the roller 10 is provided with a rubber coating.
[0050] A particularly reliable frictional engagement is hereby achieved in particular if the rubber coating of the roller 10 is made of nitrile butadiene rubber (NBR). Preferably, the outer surface of the roller 10 is hereby provided, for example by coating or bandaging, with a rubber layer or a layer of raw rubber which is subsequently vulcanized at temperatures of preferably more than 120° C. The roller 10 thus coated is post-treated by bringing to the desired size and/or flattening the rubber surface, preferably by grinding. This allows achieving a high degree of evenness so that the storage phosphor plate 1 running on the rubber-coated roller 10 can be transported virtually without shocks and/or vibrations.
[0051] As can be seen from the Figure, the surface area of the ferromagnetic layer 1 d is smaller than the surface area of both non-ferromagnetic layers 1 b and 1 c . As a result, the ferromagnetic layer 1 d is also surrounded by the non-ferromagnetic layers 1 b and 1 c in the edge portion and is therefore protected against both mechanical and climatic influences, for example against corrosion.
[0052] The layers 1 b , 1 c and 1 d are preferably attached to each other by laminating. Preference is hereby given to a so-called hot-melt adhesive that is solid at room temperature fest and only becomes adhesive when heated.
[0053] In the described preferred embodiment, it is possible to make the ferromagnetic layer 1 d very thin in the manner already described hereinbefore, without compromising too much on the mechanical stability of the base layer. At the same time, the described structure of the base layer allows an extremely light configuration of it. As a result, any fall will subject this configuration, thanks to its substantially lower weight, to considerably less strain than conventional storage phosphor plates. The risk of damages to the base layer itself and/or to the storage phosphor layer 1 a located thereon is substantially reduced that way.
[0054] FIG. 5 shows a cross-section of a second example of a storage phosphor plate 1 . Additionally to the layers already illustrated by FIG. 4 , the preferred embodiment represented here shows an additional ferromagnetic area 1 e has been provided in the edge portion of the ferromagnetic layer 1 d.
[0055] The additional ferromagnetic area 1 e has, for example, the form of a strip that runs along an edge portion of the ferromagnetic layer 1 b (in this case perpendicular to the figure plane). Similarly to ferromagnetic layer 1 d , area 1 e preferably is a thin steel sheet having a typical thickness between about 0.01 mm and 0.1 mm.
[0056] Thanks to the additional ferromagnetic area 1 e , the magnetic attraction forces generated by an external magnetic field are significantly increased in this area of the storage phosphor plate 1 compared to the remaining areas of the storage phosphor plate 1 . This is particularly very advantageous if, during a so-called handling, the storage phosphor plate 1 has to be removed from an initial position, preferably from a cassette, and/or has to be returned in the initial position. Thanks to the additional magnetic area 1 e in the edge portion of the storage phosphor plate 1 , it is hereby achieved that a magnet which acts from the outside in this area can be coupled to the storage phosphor plate 1 with a particularly high attraction force and can subsequently guide the plate in a correspondingly reliable way. This is exemplified in greater detail by FIGS. 6 and 7 .
[0057] FIG. 6 shows the cross-section of a removal unit 20 comprising a substantially even ferromagnetic base plate 21 , a lateral area 22 which runs substantially perpendicular to the base plate 21 as well as a magnet 24 provided at a protrusion 23 of the lateral area 22 , preferably a permanent magnet.
[0058] FIGS. 7 a to 7 d each show both a perspective representation (left part of the Figures) and a cross-sectional representation (right part of the Figures) of the removal unit 20 shown in FIG. 6 during the multi-phase removal of a storage phosphor plate 1 from a cassette 30 .
[0059] In the phase represented in FIG. 7 a , the storage phosphor plate 1 is located inside the cassette 30 . Roller 10 and removal unit 20 are arranged in such a way that a lower area of the roller 10 can come into contact with the ferromagnetic base plate 21 of the removal unit 20 . The rotational position of the support 12 located inside the roller 10 and comprising the magnet 14 located thereon is hereby selected in such a way that the magnetic field generated by the magnets 14 is at its largest in the lower circumferential area of the roller 10 , i.e. in the contact area between roller 10 and base plate 21 of the removal unit 20 .
[0060] A corresponding drive roller puts the roller 10 into rotation in the direction of the curved arrows so that the removal unit 20 is transported by the roller 10 in the direction of the cassette 30 .
[0061] Preferably, the base plate 21 of the removal unit 20 is mounted with a certain tolerance in vertical direction so that the base plate 21 can move away downwards from roller 10 when the magnets 14 located on the support 12 point upwards and the base plate 21 can be attracted by the roller 10 (see right part of FIG. 7 a ) when the magnets 14 located on the support 12 point downwards.
[0062] In the phase shown in FIG. 7 b , the magnet 24 provided at the protrusion 23 of the lateral area 22 (see FIG. 6 ) of the base plate 21 of the removal unit 20 has reached a lateral side of the storage phosphor plate 1 and is coupled to it by magnetic attraction forces. The storage phosphor plate 1 is hereby preferably configured in the manner as shown in connection with FIGS. 4 and 5 . In particular, the ferromagnetic layer 1 d (see FIG. 5 ) comprises an additional magnetic area 1 e in the edge portion in which the magnet 24 is coupled magnetically to the storage phosphor plate 1 .
[0063] After the magnetic coupling of the removal unit 20 to the storage phosphor plate 1 , the rotational direction of the roller 10 is reversed without changing the rotational position of the support 12 and the magnets 14 located thereon with respect to the phases shown in FIGS. 7 a and 7 b . This has the effect that the removal unit 20 , together with the storage phosphor plate 1 coupled thereto, is transported in the opposite direction so that the storage phosphor plate 1 is transported out of the cassette 30 .
[0064] In the phase shown in FIG. 7 c , this process has already advanced so far that the lateral area 22 of the removal unit 20 is supported by the roller 10 and the removal unit 20 can no longer be transported further in this direction. Now, in this situation, the support 12 located inside of the roller 10 is brought into a rotational position in which the magnets 14 located thereon are oriented towards an upper area of the roller 10 that is nearest to the leading edge of the storage phosphor plate 1 . This is illustrated in the right part of FIG. 7 c . This leads to a substantial reduction of the frictional forces between the roller 10 and the removal unit 20 , whereas the magnetic attraction forces in the upper part of the roller 10 increase significantly so that, when the rotational direction of the roller 10 is reversed again, a magnetic coupling now occurs between the storage phosphor plate 1 and the roller 10 and the storage phosphor plate 1 is transported further out of the cassette 30 .
[0065] FIG. 7 d shows a phase in which the support 12 located inside the roller 10 is oriented in such a way that the magnetic field generated by the magnets 14 located on the support 12 is at its largest right in the contact area between the storage phosphor plate 1 being transported and the roller 10 . The frictional forces between the roller 10 and the storage phosphor plate 1 are correspondingly high so that a reliable transport of the storage phosphor plate 1 out of the cassette 30 is ensured.
[0066] As a result of the rotational position of the support 12 , including the magnets 14 located thereon, the base plate 21 of the removal device 20 is no longer attracted by the roller 10 so that the removal device 20 which is mounted with a vertical tolerance falls a bit downwards (see vertical arrow in FIG. 7 d ). The rotating roller 10 now only transports the storage phosphor plate 1 , preferably past the line 8 (see FIG. 1 ) in the area of the read-out device, whereas the removal device 20 maintains its position and is available for a subsequent return transport of the storage phosphor plate 1 into cassette 30 .
[0067] During the return transport, the above-described steps are executed in the reverse order until the read out storage phosphor plate 1 has been returned into the cassette 30 .
[0068] While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
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A device and a corresponding system for reading X-ray information stored in a storage phosphor plate includes a reading device for irradiating the storage phosphor plate with stimulation light and for detecting emission light stimulated in the storage phosphor plate, and a conveyance device for conveying the storage phosphor plate including at least one roller that can be put into rotation about its rotational axis. In order to guarantee, with a simple structure, the most reliable possible transport of the storage phosphor plate, one or more magnets, more particularly permanent magnets, are arranged in the interior of the cylinder which is formed as a hollow body, more particularly a hollow cylinder.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This Application claims the benefit of Ser. No. 13/611,030, filed Sep. 12, 2012 which is presently pending; and Ser. No. 11/427,490, filed Jun. 29, 2006, which is now U.S. Pat. No. 8,287,667.
TECHNICAL FIELD
The present invention relates to the treatment of the surface of cast iron brake rotors to improve performance characteristics, and more particularly to the nitrocarburizing of the surface of cast iron brake rotors to mitigate the effects of rotor surface oxidation and corrosion.
BACKGROUND OF THE INVENTION
The brake rotor is an integral component of braking systems across multiple types of motor vehicles. The disc brake is an energy conversion device which converts mechanical energy to heat. Disc braking systems consist of a non-rotating friction material and application sub-systems, as well as a brake rotor that rotates with the wheel. To stop or slow the vehicle the friction material sub-system is engaged with the braking surfaces (rotor cheeks) of the brake rotor to generate heat due to friction, thereby converting mechanical energy to heat, and thereby slowing the rotation of the wheel.
The performance of the braking system, in general, and the brake rotor in particular, is determined to a large extent by the condition of the surface finish of the rotor cheeks. The normal course of operation of a brake system involves production of high levels of friction, which, in turn, generates high temperatures on the rotor cheek surfaces. Environmental effects caused by exposure to corrosive agents, such as road salt and water, exacerbate these problems. These effects, either singly or in combination, can result in pedal pulsation or a corroded braking surface.
The braking system is an aggressive environment for corrosion and high temperature oxidation of cast iron brake rotors. The oxides produced can preferentially spall during normal brake applications. Oxide spalling produces local high spots, which form deep grooves or scoring of the rotor cheek surfaces. These surface features can produce pedal pulsation during braking.
Open style wheel designs, which are currently very popular, leave the rotor braking surfaces visible to onlookers. Surface corrosion that would normally be inconsequential in the operation of the braking system becomes an issue due to the perception of this oxidation.
A variety of methods have been attempted to improve the performance of brake rotor surfaces with respect to oxidation and corrosion. Aluminum rich paint, such as a B90 coating, may be applied to the rotor, but is readily removed during an initial brake application. Ceramic coatings and metallic plates provide corrosion protection, however, these have negative, undesirable braking characteristics.
Gaseous ferritic nitrocarburizing provides a durable corrosion and oxidation resistant diffused case without a large negative effect on braking performance. However, this process may produce geometric distortions that are problematic. Additionally, gaseous ferritic nitrocarburizing may involve long cycle times. Case hardening techniques such as conventional carbonitriding as performed above a critical temperature of the ferrous material, can result in very high distortion, long cycle times and a case structure that is not optimized for corrosion performance.
Therefore, what remains needed in the art is a means of producing a ferritic nitrocarburized surface treatment of cast iron brake rotors, without causing distortions such as thickness variation and lateral run out, which provides corrosion and elevated temperature oxidation resistance.
SUMMARY OF THE INVENTION
The present invention is a means for producing a ferritic nitrocarburized surface treatment of cast iron brake rotors to thereby provide oxidation resistance and an absence of distortion to the case structure.
According to the present invention, a two salt bath ferritic nitrocarburizing process is used to treat ferrous brake rotors, wherein these treated brake rotors have improved properties of corrosion and high temperature oxidation resistance and have improved durability. The present invention involves a processing sequence and fixturing for salt bath ferritic nitrocarburizing while maintaining dimension control in the areas of lateral run out and thickness variation.
The basic process involves nitrocarburizing of either stress relieved or non-stress relieved finish machined pearlitic cast iron (ferrous material) brake rotors. The machined brake rotors are first pre-heated in air to a moderately elevated temperature. The brake rotors are then immersed (submerged) into a molten nitrocarburizing salt bath at an elevated, but sub-critical, temperature for a first predetermined dwell time. After removing the brake rotors from the nitrocarburizing salt bath, the brake rotors are directly immersed (submerged) into an oxidizing salt bath at a moderately lower temperature than the nitrocarburizing salt bath so that the brake rotors are thermally quenched by being rapidly cooled to the oxidizing salt bath temperature. After a predetermined second dwell time in the oxidizing salt bath, the brake rotors are removed from the oxidizing salt bath and further cooled to room temperature, either by water application thermal quenching or slow cooling in air.
According to the present invention, salt bath ferritic nitrocarburizing is a thermo-chemical diffusion process, whereby a pearlitic cast iron brake rotor is immersed (submerged) in an elevated, but sub-critical, temperature nitrocarburizing salt. This elevated temperature is kept below the critical temperature, which is the temperature at which a phase transition in the material of the brake rotor may occur. The resulting chemical reactions produce free nitrogen and carbon species which in turn diffuse into the surface of the brake rotor and combine with the iron therein, thus providing a hard case composed of a shallow compound zone, as for example of about 0.015 millimeters deep and having a hardness as for example of about at least HRC 50 equivalent which is resistant to wear and provides corrosion protection, and a subjacent diffusion zone of approximately 0.15 millimeters deep. The relatively short dwell time at the elevated temperature of the nirocarburizing salt bath, unique with salt bath ferritic nitrocarburizing, provides for control over the distortion of the brake rotors, which is a significant advantage over other (ie., gaseous) nitrocarburizing processes.
Another significant advantage the present invention has over other nitrocarburizing techniques is the degree of protection for the iron brake rotors from corrosion. This protection is produced through the treatment of the brake rotors after removal from the nitrocarburizing salt bath by immersing them into an oxidizing salt bath. The oxidizing salt bath oxidizes a surface layer of the compound zone of the cast iron brake rotor, thereby creating an oxidation resistant layer of protection greatly improving the wear properties of the cast iron brake rotors. This layer consists primarily of Fe 3 O 4 , as noted in FIG. 1B .
Accordingly, it is an object of the present invention to provide a means to create a corrosion and high temperature resistant case at the surface of cast iron brake rotors, while maintaining dimensional control.
This and additional objects, features and advantages of the present invention will become clearer from the following specification of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a depiction of a photomicrograph of the surface structure of the diffused case formed by a two salt bath ferritic nitrocarburizing of a pearlitic cast iron ferrous material brake rotor according to the present invention.
FIG. 1B is an X-Ray diffraction pattern of the brake rotor of FIG. 1A , depicting the phase composition at the outer most surface thereof, particularly indicating the presence of iron oxide (Fe 3 O 4 ).
FIG. 2 is a block diagram showing the steps of the two salt bath ferritic nitrocarburizing of brake rotors according to the present invention.
FIG. 3A is a graph showing the depth of the compound zone as a function of time the brake rotor has spent in the ferritic nitrocarburizing salt bath.
FIG. 3B is a graph showing the depth of total nitrogen diffusion as a function of time the brake rotor has spent in the ferritic nitrocarburizing salt bath.
FIG. 4A is a side view of a rotor holder for holding a single brake rotor during placement in a ferritic nitrocarburizing salt bath according to the present invention.
FIG. 4B is a sectional view, seen along line 4 B- 4 B of FIG. 4A .
FIG. 5 is a partly sectional side view of a fixture for grouping rotor holders, each supporting, in mutually spaced relation, brake rotors in either of a ferritic nitrocarburizing salt bath or an oxidizing salt bath according to the present invention.
FIG. 6 is a graph, the plots of which showing results of wear tests of production brake rotors and brake rotors having surface ferritic nitrocarburizing treatment according to the present invention.
FIG. 7 is a graph, the plots of which showing results of thickness variation tests of stress relieved and non-stress relieved brake rotors having surface ferritic nitrocarburizing treatment according to the present invention.
FIGS. 8A and 8B are graphs, the plots of which indicating braking noise tests for production brake rotors and brake rotors having surface ferritic nitrocarburizing treatment according to the present invention, wherein FIG. 8A pertains to cold rotors and FIG. 8B pertains to warm rotors.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the Drawing, FIGS. 1A through 5 depict an example of a two salt bath ferritic nitrocarburizing system (process and apparatus) for producing a ferritic nitrocarburized surface treatment of cast iron brake rotors. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its applications, or its uses.
FIG. 1A shows a cross-section of the surface microstructure of a ferrous material 100 , a pearlitic cast iron brake rotor, subjected to the salt bath ferritic nitrocarburizing process according to the present invention. This process initially introduces carbon and nitrogen simultaneously from a nitrocarburizing salt bath into the surface S of the ferrous material 100 (an aluminum foil Al which is shown is merely an artifact of the testing set-up, and it does not form a part of the ferrous material 100 ). Thereafter, the ferrous material 100 is treated in an oxidizing salt bath. This step of the process creates a layer of Fe 3 O 4 .
As a result of this two bath nitrocarburzing process according to the present invention, there are two distinct regions, or zones, of material: a compound zone 102 and a subjacent nitrogen diffusion zone 104 which is not resolvable metallographically in the ferrous material 100 (pearlitic cast iron).
The compound zone (layer or region) 102 is an outer portion of the ferrous material 100 after being treated first in the ferritic nitrocarburizing salt bath, then subsequently in the oxidizing salt bath. The compound zone 102 is formed initially through the reaction between the iron of the ferrous material 100 and nitrogen and carbon species from the nitrocarburizing salt bath. The compound zone 102 at this point is essentially a new phase of material, consisting predominantly of epsilon iron nitride, Fe 3 N and a smaller volume of gamma prime iron nitride Fe 4 N. Thereafter, the ferrous material 100 is subjected to the oxidizing salt bath, whereupon a surface oxide layer 102 a is formed composed of oxidized nitrocarburzied iron, Fe 3 O 4 .
The diffusion zone (layer or region) 104 is disposed subjacent the compound zone 102 (ie., further into the ferrous material 100 ), consisting of the iron base ferrous material with a lower concentration of diffused nitrogen than that found in the compound layer, and with the nitrogen in solid solution with the base material. The depths of these two zones, i.e. compound zone 102 and the diffusion zone 104 , are predictable and reproducible, which is a primary factor in the control of dimensional growth of the brake rotors as a result of the process
Referring now to FIG. 1B , shown is an X-ray diffraction pattern 110 of the ferrous material 100 of FIG. 1A . (The specimen used to produce the photomicrograph, FIG. 1A , was taken from the same section of the brake rotor as the specimen used for the X-ray diffraction analysis, FIG. 1B . Technically, they may be considered two adjacent specimens from the same sample, and thus the surfaces examined represent the same microstructural characteristics.). The surface structure of the ferrous material is determined through employing Bragg's law, which relates the angle of X-Ray diffraction to the depth of the layer scattering the X-Rays. A sufficiently thick layer of material is required in order to create the constructive interference patterns shown in FIG. 1B . The thicker the layer, the more intense the X-Ray scattering, as indicated by higher count levels shown in FIG. 1B . The feature labeled N is the diffraction peak for iron nitride. The features labeled O 1 through O 4 are associated with layers of Fe 3 O 4 , most notably O 2 . This diffraction pattern provides independent corroboration of the photomicrographic assignments of FIG. 1A .
FIG. 2 is a block diagram of the salt bath nitrocarburizing process 200 according to the present invention. The process begins at Block 202 , whereat casting of pearlitic cast iron (ferrous material) brake rotors is performed in a generally conventional or known manner. At Decision Block 204 , a decision is made whether to stress relieve the brake rotors from Block 202 . If yes, then the process proceeds to Block 206 , whereat stress relief is performed and the process then proceeds to Block 208 . If no, then the process proceeds directly to Block 208 .
At Block 208 finish machining of the brake rotors is performed. This is performed now because of the dimensional controls of the salt bath nitrocarburizing process of the present invention obviates machining later in the process. In this regard, since the dimensional growth of the brake rotors is predictable, the process is preferably adjusted by empirical or theoretical analysis so that the brake rotors will not require further machining upon completion of the salt bath nitrocarburizing process.
At Block 210 , the brake rotors are preheated prior to submersion into the ferritic nitrocarburizing salt bath. This is accomplished through air heating in convection ovens or furnaces to about, for example, 400 degrees C. Pre-heating ensures the brake rotors will be free of moisture, which, if present, would react violently with the contents of the ferritic nitrocarburizing salt bath. Additionally, the pre-heating of the brake rotors is more efficiently performed ex-situ the nitrocarburizing salt bath as compared to allowing the brake rotors to come to thermal equilibrium in the ferritic nitrocarburizing salt bath from a substantially much lower temperature (ie., room temperature).
At Block 212 , a nitrocarburizing salt bath is utilized. This salt bath consists of salts and reagents necessary to perform the ferritic nitrocarburizing surface treatment of the cast iron brake rotors. This salt bath consists of between 25 and 57 percent by weight cyanate, calculated as cyanate ion, between 0 and 5 percent by weight cyanide, calculated as cyanide ion, between 0 and 30 percent by weight alkali metal chloride and the balance as potassium ion, sodium ion and carbonate ion. The most preferred embodiment consists of between 34 percent and 38 percent by weight cyanate ion, with a target of 36 percent, between 0.5 percent and 3.0 percent by weight cyanide ion, with a target of 2 percent, and a target of 20 percent by weight of carbonate ion. In addition, the target ratio of potassium ion to sodium ion is 4 to 1.
An organic polymer regenerator is added to the nitrocarburizing salt bath at regular intervals to maintain stable concentrations of the cyanate ions necessary for the nitrocarburizing reactions. A preferable regenerator is either melamine or urea or a derivative of melamine, such as melam, melem and melom.
During processing, the cyanate ions of the salt bath react at the metal surface of the brake rotors as follows:
4KOCN→K 2 CO 3 +2KCN+CO+2N*
2CO→CO 2 +C**
KCN+CO 2 →KOCN+CO
2KCN+O 2 →2KOCN
Nitrogen and carbon react with the iron of the ferrous material 100 as follows:
*N+3Fe→Fe 3 N
**C+3Fe→Fe 3 C
At Block 212 , the brake rotors are immersed (submerged) into the nitrocarburizing salt bath at about, for example, 579 degrees C. for a period between 1 and 2 hours, more preferably for about one hour. This process introduces nitrogen and carbon into the surface structure of the brake rotor as described with respect to FIG. 1 .
At Block 214 , the brake rotors are removed from the nirtocarburizing salt bath, transferred to, and thereupon submerged in, an oxidizing salt bath at about 427 degrees C. for about 20 minutes. This oxidizing salt bath is an alkali hydroxide/nitrate mixture that oxidizes nitrocarburized ferrous material forming a combined oxide/nitride compound zone with a high resistance to corrosion. The preferred embodiment contains between 2 percent and 20 percent, most preferably between 10 percent and 15 percent, by weight nitrate ions, in the form of either sodium or potassium nitrate, between 25 percent and 40 percent by weight carbonate ion, in the form of either sodium or potassium carbonate, and the balance as hydroxide ion, in the form of either sodium or potassium hydroxide.
During this process, the following neutralization reactions occur:
CN −1 +3OH −1 +NO 3 −1 →CO 3 −2 +NO 2 −1 +NH 3 +O −2
CNO −1 +3OH −1 →CO 3 −2 +NH 3 +O −2
[Fe(CN) 6 ] −4 +6NO 3 −1 →FeO+5CO 3 −2 +6N 2 +CO 2
Additionally, the oxidizing salt bath is used as an intermediate thermal quenching step to cool the brake rotors with minimal thermal differentials and mitigation of potential distortions.
At Block 216 , the brake rotors are removed from the oxidizing salt bath of Block 214 and are further cooled to room temperature either by air-cooling or a further step thermal quenching by water application (spray or dip) cooling. The nitrocarburized cast iron brake rotors are then water rinsed to remove reagents of Block 214 , and then are oil dipped, whereupon the nitrocarburized brake rotors are ready to be shipped for motor vehicle assembly.
FIG. 3A shows a graph 250 with a plot 252 indicative of compositional layers within the ferrous material 100 of FIG. 1A . The plot 252 shows the depth of the compound zone 102 of FIG. 1A as a function of the time the brake rotor dwells in the nitrocarburizing salt bath at Block 212 . This depth is determined by measuring the depth of the highly concentrated nitrogen species diffusion into the iron substrate 100 of FIG. 1A . The data shows that after one hour of submersion in the ferritic nitrocarburizing salt bath, the compound zone has a depth of 0.011 millimeters. After two hours of submersion in the ferritic nitrocarburizing salt bath, the data shows the compound zone has a depth of 0.018 millimeters.
FIG. 3B shows a graph 260 with a plot 262 showing the depth of the total nitrogen diffusion region. The data shows that after one hour of submersion in the ferritic nitrocarburizing salt bath, the total nitrogen diffusion zone has a depth of 0.14 millimeters. After two hours, of submersion in the the ferritic nitrocarburizing salt bath, the data shows the total nitrogen diffusion zone has a depth of 0.18 millimeters. This data is important because the depth of nitrogen diffusion into the ferrous material 100 is correlated with enhancement of mechanical engineering properties of the brake rotors
Turning attention now to FIGS. 4A through 5 , a preferred fixture for placement of the brake rotors into the nitrocarburizing and oxidizing salt baths.
Referring firstly to FIGS. 4A and 4B , a rotor holder 300 for supporting an individual brake rotor 302 includes a hub 304 having a central opening 306 , which may preferably be of a square shape. A pair of rotor support posts 308 , 310 , are rigidly affixed to the hub 304 , whereby the rotor support posts are at, preferably, 90 degrees to each other, wherein where the hub has a square shape it is preferred for the rotor support posts to be oriented orthogonally to the corners of the hub, as depicted in FIG. 4A . An L-shaped rotor location post 312 is rigidly affixed to the hub at a location on the opposite side of the hub 304 in relation to a bisection of the angle subtending the rotor support posts.
The dimensions of the rotor support posts 308 , 310 and the rotor location post 312 in relation to a brake rotor are as follows: the rotor support posts abut the inner race 302 a of the brake rotor such that the hub is concentrically disposed with respect to the inner race; and a terminal end 312 a of the rotor location post abuts the inner face 302 b of the brake rotor hat 302 c such that the plane of the center of gravity CG of the brake rotor bisects the rotor support posts, as depicted at FIG. 4B .
It is to be understood from the foregoing structural description, that the rotor holder 300 interfaces with only three local locations a, b, c of the brake rotor 302 , all of which being locations at which an absence of treatment by the two bath nitrocarburizing treatment process according to the present invention has no noticeable effect; indeed all other areas of the brake rotor are fully exposed, particularly the brake rotor cheeks 302 d , 302 e and the exterior side 302 f of the brake rotor hat 302 c . In addition, it will further be seen that the placement of the brake rotor 302 onto the rotor holder 300 is extremely simplistic, as there are no mechanical interlockings, yet the brake rotor will rest upon the rotor in a completely stable manner.
Referring now to FIG. 5 , an example of a rotor holder fixture 320 composed of a plurality of the aforedescribed rotor holders 300 will be detailed.
The rotor holder fixture 320 is provided with a suitably large circumscribing base 322 for stably resting upon a floor 324 a of a tank 324 , wherein the tank holds a salt bath 326 , either the nitrocarburizing salt bath or the oxidizing salt bath of the two bath nitrocarburizing treatment process according to the present invention. A mast 328 is rigidly affixed centrally to the base 322 and rises up through the tank (ie., extends normal to the floor 324 a ). The mast 328 provides the support of any number of interconnecting segments, as for example segment 328 a , segment 328 b , and segment 328 c , as shown at FIG. 5 .
At suitable junctures in height above the base 322 (to provide adequate bath access spacings between adjacent brake rotors, as discussed hereinbelow), arms 330 are perpendicularly attached to the main segments, 328 a , 328 b , and 328 c , as for example by welding. In the view of FIG. 5 , there are three vertical sets of pairs of arms 330 (one pair of arms for each mast segment), as would suit a tank having an elongated rectangular shape. If the tank were shaped round or square, then an additional three vertical sets of pairs of arms would be attached to the mast (one additional pair of arms for each mast segment) in a direction perpendicular to the arms shown (ie., in and out of the plane of the paper).
Slid onto each arm 330 , which may or may not include splines 340 therebetween, is a holder sleeve 342 . Any number of rotor holders 300 , as above described with respect to FIGS. 4A and 4B , may be connected rigidly to a holder sleeve 342 , as for example by the hub thereof being integral with the holder sleeve. In the exemplar view of FIG. 5 , the hubs of three rotor holders are integral constituents of each holder sleeve.
It will be seen by reference to FIG. 5 , that with each rotor holder 300 loaded with its respective brake rotor 302 , the salt bath 326 is able to wet the brake rotors everywhere, except the three aforementioned rotor holder contact locations (see a, b, c of FIG. 4B ). Additionally, it will be noted that a suitable horizontal distance L is maintained between brake rotors 302 parallel to the arms 330 and vertical distance L′ parallel to the mast 328 so that the bath 326 has free and open access to each and every brake rotor, whereby dimensional control is provided during treatment in the bath.
To vertically lift and lower the rotor holder fixture 320 , a conventional lifting apparatus is utilized (not shown) which interfaces with the mast 328 . For example, a crane apparatus may engage the upper end of the mast via a gripper or other mechanism.
In operation, the rotor holder fixture is assembled in terms of the base, mast, arms and rotor holder carrying holder sleeves. Next, each rotor holder is loaded with its respective brake rotor. The rotor holder fixture is then subjected to the pre-heating step, as described hereinabove, and then the rotor holder fixture is lowered into the tank so that all the brake rotors are wetted by the salt bath. Upon completion of the desired bath dwell time, the rotor holder fixture is then removed from the tank for further processing of the brake rotors according to the present invention.
Dimensional change of the brake rotors during the process according to the present invention may be due to either mechanically induced stresses and/or stresses developed due to thermal conditions.
Regarding mechanical stresses, there is a benefit to properly supporting the rotor during the process according to the present invention by the configuration of the rotor holder 302 and the fixture 320 . A further advantage of placement of the brake rotors into the salt bath 326 is buoyancy of the brake rotors, whereby the high density of the liquid medium of the salt bath provides added support to the brake rotor during salt bath treatment, which thereby tends to mitigate mechanical stresses.
Regarding thermally induced stresses, a few processing parameters need to be considered: the temperature of the nitrocarburizing salt bath; dwell time within the nitrocarburizing salt bath, per its temperature; and the rate of cooling of the brake rotors thereafter. The temperature of nitrocarburizing salt bath is based on empirically produced microstructural phase diagrams that define the required chemical reactions as a function of temperature. For a nitrocarburizing salt bath as used according to the present invention to treat brake rotors, a temperature of about 580 degrees C. is preferred. The depth of the nitride compound that is formed is dependant on the length of time (dwell time) of the brake rotor at this temperature.
Greater dimensional stability of the rotor can be best achieved by minimizing the dwell time at a given nitrocarburizing salt bath temperature. Chemical reactions within the nitrocarburizing salt bath develop a high nitrogen concentration (activity) which in turn enables shorter dwell times (as compared with gaseous dwell times) at a given temperature.
Minimizing thermal differentials within the brake rotor as it is cooled from the nitrocarburizing salt bath temperature also helps to reduce thermally induced stresses and, thus, encourages dimensional stability. This is accomplished by interrupted cooling, or step quenching from the nitrocarburizing salt bath temperature to room temperature by using a quench salt bath of about 427 degrees C., then followed by water or air cooling to room temperature.
Conventional production brake rotors (production rotors) were compared in a series of tests to brake rotors treated by the process according to the present invention (treated rotors).
In a series of friction tests, the apparent friction of a production rotor was compared to that of a treated rotor and was found to be, on average, only four percent above that of a treated rotor (indeed, for burnished brake rotors, the treated rotors had higher friction, for both cold and warm tests, than the production rotors). Therefore, it can be concluded that brake rotor friction is acceptably high for brake rotors treated by the process according to the present invention.
In a series of wear tests, as shown at FIG. 6 , three production rotors 402 , 404 , 406 were compared, respectively, with three treated rotors 403 , 405 , 407 (ie., production rotor 402 compared to treated rotor 403 , production rotor 404 compared to treated rotor 405 , and production rotor 406 compared to treated rotor 407 ). The resulting graph 400 of lateral run out per thickness variation (LRO/TV) versus motor vehicle driving mileage indicates that the treated rotors wear quite favorably as compared with the production rotors.
A series of thickness variation tests were conducted, shown at FIG. 7 , for pairs of batches of six stress relieved treated rotors and non-stress relieved (as cast) treated rotors for one hour nitrocarburizing salt bath treatment, graphs 500 and 502 respectively, and two hour nitrocarburizing salt bath treatment, graphs 504 and 506 , respectively. It will be seen from FIG. 7 that stress relieved treated rotors have a less thickness variation than non-stress relieved treated rotors, and that the treated rotors having one hour dwell in the nitrocarburizing salt bath had less thickness variation than those having a two hour dwell time.
A series of noise tests were conducted. As shown by the graph 600 of FIG. 8A of percent noise versus decibels, cold production rotors 602 , 604 were compared to cold treated rotors 601 , 603 . It is seen from FIG. 8A that the cold treated rotors had noise levels quite favorable as compared to the cold production rotors. As shown by the graph 610 of FIG. 8B of percent noise versus decibels, warm production rotors 612 , 614 , 616 , 618 were compared to warm treated rotors 611 , 613 . It is seen from FIG. 8B that the warm treated rotors had noise levels quite favorable as compared to the warm production rotors.
To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.
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A number of variations may include a brake rotor having a surface oxide layer and methods of making the same.
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BACKGROUND OF THE INVENTION
The present invention relates to a handbrake compensator for braking devices on the wheels to be used in modern motor vehicles as a safety device.
Handbrake compensators used as safety devices in motor vehicles are known. Special conditions of the assembly process on the lines of the large motor manufacturing works require a considerable time to adjust a prior tension of the handbrake cable which connects the handle of the brake with the rear wheel brake. At the present time, such adjustment is a manual operation, and the operator must check the cable tension in each motor vehicle in order to adjust the length of either the cable or the sheath by rotating a small specific tension adjusting mechanism by a greater or lesser number of turns until a predetermined tension is obtained.
Since the tension adjustment elements of the handbrake are located under the automobile chassis and very close to the sheet metal and despite the fact that the vehicle body being assembled is moved upwards, the adjustment operation is uncomfortable and requires from the operator carrying it out a great degree of attention. Furthermore, the amount of the adjustment to be made is variable within wide limits and has no specific law of correlation, which requires even more attention to be paid to the adjusting operation.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved handbrake compensator.
It is another object of the invention to provide a handbrake compensator easily mountable in the motor vehicle.
Yet another object of the invention is to provide a handbrake compensator which is easy and economical to manufacture and assemble and which is self-adjustable to the extent of providing the cables with a predetermined desired tension with an admissible tolerance.
These and other objects of the invention are attained by a handbrake compensator for motor vehicles, comprising support means having an axis of elongation and including a substantially tubular body closed at one end thereof and including at an opposite end two parallel flanges; load distributor means including two superimposed parallel wings positioned between said flanges; spring means accommodated in said tubular body and being maintained in a compressed position against said load distributor means; a cap screw extending through said flanges and said wings; a primary cable having a terminal inserted in said load distributor means; at least one secondary cable connected to said load distributor means, said screw holding said terminal of said primary cable in the handbrake compensator; and closing and retaining means provided on said cap screw, said wings each including an elongated slot through which said cap screw passes, one of said slots having two opposite toothed edges extended along said axis of elongation and adapted to snugly receive a portion of said cap screw, said cap screw being insertable into said one slot in an initial position in which said load distributor means applies against said spring means a predetermined force to compress said spring means, said cap screw being removable from said one slot by pushing said cap screw so as to change a position of said load distributor means along said axis and thus adjust a tension of said primary cable relative to said secondary cable by a residual force of said spring means, said cap screw being reinsertable into said one slot between said toothed edges in a new adjusted position in which said cap screw is retained by said closing and retaining means.
The small number of components parts of the brake compensator is significantly important for obtaining an effective, reliable, low cost and long lasting device. At the same time the installation of the brake compensator in an automobile is simple and speedy, without requiring any particular specialization of the operator to carry it out appropriately.
Said elongated slots may be centrally positioned in said respective wings.
The terminal of the primary cable may have an opening through which said cap passes to hold said terminal with a ability to pivot.
The flanges may be provided with bores receiving said cap screw, said portion of said cap screw being a neck of a square cross-section, one of said bores having a square cross-section to snugly receive said neck, said neck being also engaged in said adjusted position between flanks of two pairs of consecutive teeth of said toothed edges of said one slot so that in said adjusted position said support means and said load distributor means are firmly held together.
Said one of said bores has a diagonal which may coincide in direction with said axis of elongation.
It will be understood that the rigidity of the assembly is important to ensure interchangeability in use and operation of the handbrake after the installation of the compensator according to the invention in the vehicle.
The wings of said load distributor means may have arc-shaped surfaces, an arc-shaped surface of each wing forming a channel at an inner side.
In another embodiment, the load distributor means encloses a straight channel and has a bottom portion formed with two bores which receive ends of secondary cables.
In both embodiments the elongated slots are formed in the central portions of parallel wings.
The election of one or another embodiment of the load distributor means is determined by the need of adaptation to the fact that certain types of automobiles are provided with handbrakes having two secondary cables located between the brake mechanism of each wheel and the primary cable, whereas other types of vehicles are equipped with a single cable the free ends of which are attached to the brake mechanism of each wheel, being attached at the central portion thereof to the said primary cable.
The cap screw may include a head and a shank, said neck extending between said head and said shank, said shank having an end protruding outwardly from the compensator, said closing and retaining means being positioned on said end.
The retaining means may include a wire spring formed with double bends having free ends, said shank including bores receiving said free ends, said wire spring acting on said screw as a lever to set said screw in said initial position and formed with a certain degree of reversibility to prevent accidental adjustment and said screw from being released.
Alternatively, the retaining means may include a leaf spring formed with an elongated slot through which said shank passes so as to guide said spring, said shank including a widened end portion at a free end thereof, said spring acting on said widened portion to prevent an accidental release of said screw.
The leaf spring may include projections at opposite sides of said elongated slot and acting to retain the compensator in said adjusted position.
The leaf spring may include end bends facilitating maneuverability of the leaf spring.
The provision of means preventing accidental or involuntary release of the screw is noteworthy in order to provide a real and important improvement in the manufacture of automobiles on the assembly line, allowing a saving in time and effort to be applied in the particular operation to which this invention is applied. To be precise, the particular arrangement of the cap screw advantageously replaces the pins, spring washers or retaining clips currently used for the same purpose and which must be handled with special tools and with movements requiring a greater precision than is required by the object of this invention.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a plan view of the underside of the brake compensator in an initial assembly position, according to the invention;
FIG. 2 is a top plan view of the brake compensator of FIG. 1;
FIG. 3 is a side view, partially in section, of the brake compensator of FIGS. 1 and 2;
FIG. 4 is a plan view of the underside of the brake compensator according to another embodiment of the invention;
FIG. 5 is a partially sectional side view of the brake compensator of FIG. 4; and
FIG. 6 is a top plan view of the brake compensator of yet another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings in detail, and firstly to FIGS. 1 to 3 it will be seen that the brake compensator according to the invention is comprised of support 40 which includes a substantially tubular body 1 which is closed at one end thereof as designated at 2 and two flat flanges 3 and 3' which are formed as two opposite extensions of tubular body 2. Flanges 3 and 3' are both parallel to the axis of elongation of body 2 and are wider than the tubular body 2. Each flange 3, 3' is formed with a throughbore 4, 4', respectively. Throughbores 4 and 4' receive in snug fit a neck 5 and a shaft 6 of a cap screw 50 which has a head 7.
The handbrake compensator further includes a load distributor element 8 operated to transmit stress applied to a primary cable 13 of the handbrake to and distribute this stress proportionally between two arms of a secondary cable 14, 14'. Two cables in place of two arms of one secondary cable can alternatively operate the braking devices acting on the wheels.
The load distributor element 8 includes two parallel opposing wings 9 and 10 which include therebetween a channel which is partially convex as seen in FIGS. 1 to 5 or straight as in the embodiment of FIG. 6. The tubular portion 1 and flanges 3, 3' extend partially in said channel, as seen from the drawings. Wings 9 and 10 are each provided in the middle portion thereof with an elongated slot 11, 12, respectively to receive the cap screw 50 passing therethrough and extending further through flange 3' as described above.
It is to be understood that the load distributor element 8, both with the curved channel and straight channel (FIG. 6) fulfills its function in the same manner that is it distributes stress applied to the primary cable 13 between the braking devices positioned on the two wheels of the vehicle by means of two portions 14, 14' of either single secondary cable as shown in FIG. 1 or by two secondary cables as is the case of the embodiment of FIG. 6. The terminals of two cables not shown in the embodiment of FIG. 6 are housed in two openings 21, 21'. A two-branch single secondary cable embodiment or two secondary cables are selected depending on the particular features of the automobile model in which the brake compensator is to be installed.
Referring back to FIGS. 1 to 3, it is seen that the neck 5 of the cap screw 50 has a square cross-section and its thickness is substantially equal to the sum of the thickness of flange 3 of support 40 and wing 9 of the load distributor element 8. The shank or shaft 6, i.e., the remainder of cap screw 50 is of a circular cross-section and acts as a retainer and a pivot for a terminal 15 of the primary cable 13. Terminal 15 is suitably guided between wings 9 and 10 of the load distributor element 8. A thrust head or element 18 is positioned in tubular body 1 between spring 17 and the load distributor element 8.
Slot 11 of the load distributor element 8 is provided with toothed edges 16, 16'. The teeth at these edges are of right-angle profile. Thus the opposed edges of neck 5 of the cap screw 50 may snugly fit between each pair of opposing teeth of the edges of slot 11. Throughbore 4 is also of square cross-section and oriented so as to receive neck 5 of screw 50.
Initially the brake compensator is installed in the vehicle in a retracted condition, that is with the load distributor element 8 inserted as far as possible between flanges 3 and 3' of the compensator support, and the spring 17 housed within tubular body 1 is thereby compressed by thrust head 18. This initial position is shown in FIG. 1.
The brake compensator further includes a closing and retaining mechanism 60 which includes a wire spring 19 adapted to act in the direction of arrow F2 (FIG. 3). Wire spring 19 is pivotally mounted on the free portion of shank or shaft 6 of the cap screw 50 and is provided with a double bend 20 which allows this spring to act as a lever facilitating reinsertion of neck 5 between opposing toothed edges 16, 16, of slot 11 of the load distributor element. The geometry of the double bend 20 provides the closing mechanism 60 with a certain degree of irreversability thus ensuring permanence and durability of the adjustment of the brake compensator.
In order to set and adjust the brake compensator once it was mounted in the car, it is sufficient to push the cap screw 50 in the direction shown by arrow F1 in FIG. 3 until the square neck 5 is removed from the slot formed by opposing toothed edges 16, 16' so that spring 17 will be released causing the load distributor element 8 to move outwardly until tension between the primary cable 13 and secondary cable or cables 14, 14' is balanced with a residual force of spring 17. Thereafter the closing mechanism 60, namely its wire spring 19 is operated in the direction of arrow F2 to allow reinsertion of neck 5 between suitable teeth of slot 11 as described above thereby providing a very strong adjustment.
In the embodiment illustrated in FIG. 4 in which for the sake of clarity only one part of the load distributor element 8 is shown, the closing and retaining mechanism 60 comprises a leaf spring 22 seen in FIG. 5 in a side view. Leaf spring 22 is substantially wedge-shaped and includes terminal bends 23 and 24 and an elongated slot 25 extending over a substantial part of the length of leaf spring 22. The shank 6 of cap screw 50 passes through slot 25. The free end 26 of the shank 6 of the cap screw 50 has a widened portion which is greater than the width of slot 25. Thus spring 22 bears against said widened portion so that an accidental release of leaf spring 22 is prevented. Slot 25 is provided at one end thereof with a wider passage 27 to facilitate assembly of the end 26 of the cap screw 50 and the spring 22.
The brake compensator of the embodiment of FIGS. 4 and 5 is adjusted in the following fashion:
Initially the setting and adjustment of the brake compensator, once installed in the automobile, is carried out by pushing the leaf spring 22 in the direction of arrow F3 (FIG. 5) to release the same from the initial tension and allowing release of the cap screw 50 by pushing it in the direction of arrow F1. At this stage of setting of the brake compensator, the spring 22 slides easily guided by the screw 50, the shank 6 of which is inserted in the slot 25. This release is produced when the neck 5, which is provided with the square cross-section, emerges from the position between the toothed edges 16, 16' and the spring 17 becomes slack causing the consequent movement of the load distributor element 8 outwardly until the tension of the primary cable 13 and secondary cables 14, 14' is balanced by residual tension of spring 17. Immediately the spring 22 is pushed in the direction of arrow F4 causing the reinsertion of the neck 5 of screw 50 into slot 11 between two new teeth of edges 16, 16' of the load distributor element 8.
In order to prevent the closing and retaining mechanism 60 from undesired release, that is release of screw 50 from tension of spring 22 by non-intentional or accidental situation such as blows or vibrations caused by driving the motor vehicle over rough surfaces, spring 22 is provided with small projections or protuberances 28, 28' at each side of slot 25, causing an engagement with the widened portion 26 of the screw 50, of sufficient strength to ensure the necessary degree of irreversability required in the established adjustment.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of handbrake compensators differing from the types described above.
While the invention has been illustrated and described as embodied in a handbrake compensator, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.
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A handbrake compensator for a motor vehicle includes a support having a tubular body receiving a spring and two opposing flanges. The support is connected to a load distributor element which transmits load from a primary cable to a secondary cable connected to a wheel. The load distributor element has two opposing wings provided with elongated slots which receive a cap screw which connects the load distributor element to the support. One of the slots has toothed edges so that the screw can be moved axially of the support to adjust the position of the load distributor element relative to the spring to thereby adjust tension of the cables.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Stage of International Application No. PCT/DE2004/000844, filed Apr. 23, 2004, and which claims priority to German Patent Application No. 103 18 963.7, filed Apr. 26, 2003. The disclosures of these applications are incorporated herein by reference.
FIELD OF THE INVENTION
The invention is concerned with an internal combustion engine for operation with at least two different knock resistant fuels of different knock resistances and having at least one cylinder in which the combustion of fuel takes place cyclically and a metering system for the supply of a controlled quantity of fuel to the cylinder in each cycle. An internal combustion engine of this type in accordance with the invention may be fed for example either with natural gas or gasoline as a fuel.
BACKGROUND OF THE INVENTION
So-called multi fuel engines are known that can operate with different types of fuel and are based on the Otto principle. In this kind of an engine an air-fuel mixture is compressed before an externally initiated ignition. The compression can also result in spontaneous ignition before the externally initiated ignition, which is something that is not desirable. In general, different fuels exhibit different knock resistances, i.e. their mixture with air can be compressed by different amounts before resulting in spontaneous ignition. In order to use the fuel ideally, it is preferable that the fuel be compressed as much as possible before the externally initiated ignition. The geometric compression of an engine is, however, an unalterable parameter that is usually determined by its design. This kind of an engine can thus only be ideally designed and set for one fuel with a specific knock resistance. Operating this engine with another fuel possessing lower knock resistance could result in knocking whereby the engine will sustain damage.
SUMMARY OF THE INVENTION
The object of the invention is to design an internal combustion engine that can be operated with two fuels with different knock resistances and thereby achieve a high degree of efficiency during operation with more knock resistant fuel as well as effectively avoiding knocking during operation with the fuel that is less knock resistant.
An internal combustion engine of this kind in accordance with the invention can be optimised in a manner know per se, in particular through its geometric compression ratio, for operation with the fuel considered to be more knock resistant. Knocking during operation with a fuel that is less knock resistant can be avoided in that the metering system is set to feed a smaller quantity of air-fuel mixture when using a fuel that is less knock resistant than when using a fuel that is more knock resistant, which corresponds to a reduction of the effective compression ratio for the fuel that is less knock resistant. The pressure of this smaller quantity in the cylinder is less than if a larger quantity of the more knock resistant mixture is supplied, so that critical state variables that could lead to spontaneous combustion of the fuel are not achieved even at the top dead centre of the cylinder.
One only expediently provides a reduction of the quantity of the less knock resistant mixture if this is actually required to suppress knocking, particularly in the high speed range of the engine. On the other hand, the quantities of the mixture supplied can be the same for both fuels in the case of low speeds.
The control of the supplied fuel quantities can be expediently realized in that the metering system has at least two metering instructions at its disposal and in each case selects the instruction used to meter the air-fuel mixture with respect to the fuel supplied.
The metering instruction preferably specifies the maximum quantity of air-fuel mixture to be supplied as a speed function of the speed of rotation of the combustion engine.
The internal combustion engine expediently has a valve arrangement with a plurality of change-over positions in each of which one of a plurality of inlets of the valve arrangement, which can each be respectively connected to a tank for different fuels, is connected to a supply line of the engine, whereby the metering instruction used by the metering system is linked to the change-over position of the valve arrangement. In the case of switching over from one knock resistant fuel to a less knock resistant fuel, this enables timely adaptation of the mixture quantities fed to the cylinder at the start of combustion of the less knock resistant fuel and thereby effectively protects the angina.
This kind of valve arrangement can be executed e.g. by a routing valve that optionally links one of the tanks with the supply line of the motor or by two blocking elements that are respectively located between one of the tanks and the supply line. The first alternative can be used particularly in the case of fuels that can be injected into the supply line through a common injector, i.e. particularly for two liquid fuels. The second alternative permits the use of two different injectors for the different fuels and is therefore preferred if fuels with different physical states are used.
In order to meter the mixture quantities supplied, the metering system expediently utilizes a restrictor with controllable cross section in the supply line. The restrictor is preferably located at a point in the supply line that is upstream from the injector or injectors, i.e. at a location where the supply line only supplies air. The quantity of air supplied can be reduced by reducing the cross section when using a fuel that is less knock resistant. The metering system regulates the quantity of fuel fed to the injector in accordance with this quantity of air so that a desired air-fuel ratio is maintained during combustion.
The restrictor is preferably a butterfly valve. Whereas its flow cross section is normally determined only by the control signal, that is e.g. created with the help of an accelerator pedal, the position of the butterfly valve in accordance with the invention depends not only on the control signal but also on the type of fuel used.
It is particularly preferred for the metering system to have a pre-compressor or charger in the supply line whose secondary pressure can be set lower when using the less knock resistant fuel than when using the more knock resistant fuel. This is preferably also located upstream from the injector or injectors in the supply line so that it only acts on the fresh air supplied to the motor and the quantity of fuel fed in at the injector is in each case regulated by the metering system in such a manner that the desired air-fuel ratio is maintained during combustion.
It is preferred that the internal combustion engine be designed for operation with a liquid fuel, particularly gasoline and with a gaseous fuel, particularly natural gas. The term “gaseous” does not, thereby, necessarily refer to the physical state in which the fuel is present in the vehicle's tank but to its physical state when mixed with air before combustion.
The valve arrangement in the case of this kind of an engine is preferably formed by a first stop valve that is located between the tank for the gaseous fuel and the fuel supply line of the engine and a pump disposed between the tank for the liquid fuel and the fuel supply line, which develops a blocking effect when in the switched off state and thus acts as a second stop valve.
It is of advantage for the combustion engine to have a compression ratio of at least 11.5 but preferably of approximately 12.5 to 13. This compression ratio is higher than the ratio of approximately 10.5 which is typical for a gasoline driven engine but well matched to the high knock resistance of natural gas.
If another fuel is chosen as being the most knock resistant, it is preferred that the quantity of the mixture supplied be smaller than the maximum mixture quantities that can be fed to the engine in order to avoid the mixture achieving state variables in the cylinder at which there is a danger of knocking.
It is advantageous that the process for combustion of gasoline in an engine be initiated with a compression ratio of at least 11.5 and preferably approximately 12.5 to 13.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
An exemplary embodiment of the invention which is to be particularly preferred is explained in more detail in the following with reference to the Figures, wherein:
FIG. 1 is a schematic illustration of a vehicle with an internal combustion engine in accordance with the invention;
FIG. 2 illustrates engine characteristics of the combustion engine in accordance with the invention when driven by natural gas; and
FIG. 3 illustrates engine characteristics of the combustion engine in accordance with the invention when driven by gasoline.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
An example of an Otto engine for an internal combustion engine in accordance with the invention is described with reference to FIG. 1 that can be operated with both natural gas as well as with gasoline. The spark ignition engine in accordance with the invention has an engine block 11 that typically has four or six cylinders that are designed and constructed for operation principally with natural gas as fuel. Since the knock resistances of natural gas correspond to those of a fuel with up to RON 130 while normal gasoline has a value of RON 95 , the spark ignition engine in accordance with the invention is executed with a compression of approximately 13:1 compared to a standard compression of 10.5:1 in a normal, gasoline-driven spark ignition engine. This greater compression is enabled by the higher knock resistance of natural gas when compared to gasoline and results in a higher degree of thermal efficiency in the spark ignition engine in accordance with the invention, which is around 5 to 7% more than the degree of thermal efficiency in a gasoline driven, normal spark ignition engine.
The engine block 11 is incorporated in a vehicle that has two fuel tanks 12 , 13 , a main tank 12 for natural gas and an auxiliary tank 13 for gasoline. The auxiliary tank 13 for gasoline is necessary since the number of gasoline filling stations at which natural gas can be tanked is still very small and it could be necessary to drive the vehicle temporarily with gasoline in order to be able to reach the next available natural gas fuelling station when the main tank 12 is empty.
The spark ignition engine in accordance with the invention is therefore driven with gasoline instead of with natural gas when in reserve operation. However, in the case of a high compression of approximately 13:1 for which the spark ignition engines in accordance with the invention are designed, gasoline would combust with knocking and result in damage to the engine if the engine were to be supplied with the same maximum quantity of air-fuel mixture in the case of gasoline operation, as is suitable for operation with natural gas at the same engine speed. In order to prevent this, a metering system 14 of the spark ignition engine in accordance with the invention—that normally serves to supply natural gas to the engine block 11 From the tank 12 and, when the latter is empty, fuel from tank 13 — is designed to take account of this. The type of fuel supplied is taken into consideration when metering the mixture quantity fed to the engine in each combustion cycle.
The metering system 14 comprises a valve arrangement, a butterfly valve 16 and an electronic control circuit 17 . The valve arrangement serves to permit entry of only one fuel at a time to a supply line 23 of the engine. It includes a stop valve 15 and a gasoline pump 20 that connect the main tank 12 and the auxiliary tank 13 to respective injectors 21 and 22 that are delegated to the supply line 23 of the engine. The butterfly valve 16 is also located in the supply line, upstream from the injectors 21 , 22 . The fuel pump 20 is of a type such that it blocks the line in which it is located when it is not in operation e.g. a piston pump. It is therefore, impossible for gasoline to enter the supply line 23 at the same time that the engine is being operated with natural gas or for a natural gas-air mixture to reach the auxiliary tank.
The electronic control circuit 17 receives, via the first signal input, a signal for desired performance that is, for example, dependent on the position of the accelerator pedal 18 , via a second signal input, a signal from a speed sensor 19 located at a shaft of the engine 11 and, via a third signal input, a signal that indicates which engine fuel supply is currently in operation, i.e. whether the stop valve 15 is open or the fuel pump 20 is switched on. Depending on which engine fuel supply is in operation, the control circuit 17 uses one of two pre-determined metering instructions that are stored in an electronic memory of the control circuit, in order to regulate the position of the butterfly valve 16 and therewith the quantity of air-fuel mixture supplied to each cylinder. These metering instructions determine the quantity of mixture supplied in dependence on the performance required from the engine and/or on the position of the accelerator pedal 18 that is representative of this. At least the metering instructions used for the fuel that is less knock resistant further contains an upper limit for the quantity of mixture supplied that is not to be exceeded in order to avoid knocking in the engine 11 , independent of the performance required at any one time. This upper limit is determined in dependence on the speed of the engine registered by the sensor 19 . This upper limit can be determined in that the mechanical load is varied for a plurality of speeds in an engine prototype and the upper limit of mixture quantities supplied without resulting in knocking is tested. It has been found, particularly in the case of high speeds, that it is necessary to limit the maximum mixture quantity supplied for less knock resistant mixtures to a value that is less than that of the maximum quantity of the more knock resistant mixture supplied at the same speed, while the maximum quantities supplied at lower speeds could also possibly be set to be the same.
This kind of speed-dependent upper limit of mixture quantities supplied can naturally also be provided for knock resistant fuel, particularly in specific ranges of the speed of rotation.
The regulation of the mixture quantity that is controlled below this upper limit, in dependence on the engine load or on the performance demanded from it can in principle, take place in the customary manner whereby however, the dependence of the mixture quantity supplied on the performance required at a given speed of rotation could be different for both fuels.
A compressor or a charger can also be located in the supply line 23 in the place of the butterfly valve 16 , which injects fresh air under adjustable high pressure into the supply line. In this case the effective compression of the air-fuel mixture in the cylinder comprises the compression by the charger and the geometric compression in the cylinder. Analogously, as described above for the butterfly valve, by operating the charger with different compression depending on the fuel used, the quantity of mixture supplied to the cylinder when using the less knock resistant fuel can be reduced.
In FIG. 2 different engine characteristics for the spark ignition engine in accordance with the invention are displayed that have been determined on an engine test stand during which the spark ignition engine was driven by natural gas. All characteristics are plotted in dependence on the engine speed that is entered along the X axis in revolutions per minute. Characteristic 1 shows the engine performance found. This begins at 10 kW with an engine speed of 1000 rpm and increases to 70 kW at an engine speed of just over 6000 rpm. The build-up thereby takes place increasing monotonically with a slight kink at around 4000 rpm and 60 kW.
Characteristic 2 represents the torque M generated by the engine. It starts at approximately 98 Nm at 1000 rpm and increases to just over approximately 137 Nm at 4000 rpm to in order to fall again at beyond 4000 rpm.
FIG. 3 displays corresponding characteristics for the same engine when driven by gasoline as the fuel. At first glance the characteristics in FIG. 3 appear to be less uniform when compared to those in FIG. 2 . Thus, for example, the characteristic 4 for engine power P in the range of 1000 rpm up to 4000 rpm increases strictly monotonically from 10 kW to approximately 47 kW and exhibits alternatively falling and increasing trends at speeds of more than 4000 rpm. The characteristic 4 achieves its maximum at just over 5000 rpm with 52 kW in the speed range illustrated. This maximum lies clearly below the maximum of 70 kW of characteristic 1 .
The characteristic 5 behaves in a similar manner for the torque M of the engine. This increases strictly in the range from 1000 rpm up to 4000 rpm from 75 Nm to 113 Nm. However, it falls more steeply at over 4000 rpm when compared to characteristic 2 , then increases slightly between 4500 rpm and 5500 rpm and subsequently falls abruptly.
A direct comparison of the performance characteristics 1 and 4 shows that performance achieved with gasoline as the fuel for speeds N up to 4000 rpm is slightly less than that achieved with natural gas. The difference between characteristics 1 and 4 increases with increasing speed N. The difference in curves 1 and 4 becomes markedly noticeable for speeds N above 4000 rpm. i.e. markedly reduced performances are achieved with gasoline operation of the engine at these speeds.
The reduced engine performance P and the smaller torque M of the engine are, however, generally secondary and acceptable since operation of the engine with gasoline takes place only in reserve operation or in emergency operation. The restriction of the mixture quantity that results in lowered performance reliably reduces knocking as well as damage during operation with a less knock resistant fuel.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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The invention relates to an internal combustion engine which can be operated with at least two fuels that have different knock resistance and which comprises at least one cylinder in which combustion of the fuel takes place cyclically. Said engine is provided with a dosing system for feeding a controlled quantity of fuel to the cylinder in every cycle. The dosing system is designed in such a manner that, when fuels are used that are less resistant to knocking, the quantity of air-fuel mixture supplied is maintained below a threshold quantity at which there is no danger of knocking.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 60/144,508 filing date Jul. 19, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to downhole oil field tools. More particularly, the invention relates to performance enhancing devices for inflatable elements.
2. Prior Art
Inflatable elements such as packers have been known and used in the hydrocarbon production industry for a substantial period of time. During this time they have been reliable and favored by oil well operators in many sealing operations. Prior art inflatable elements have however had difficulty with setting in noncylindrical boreholes. Noncylindrical boreholes include oval boreholes, unconsolidated boreholes, windows, etc. The problems of the prior art inflatable elements in noncylindrical boreholes has been that the rubber of the inflatable boot is extruded through the ribs of the element. This can cause severe damage to the rubber of the boot and to the ribs of the element and may result in failure of the device. Thus, the art is in need of a means to avoid extrusion of the rubber boot of the inflatable element through the rib portion of the inflatable element during inflation of a tool in a noncylindrical environment.
SUMMARY OF THE INVENTION
The above-identified drawbacks of the prior art are overcome or alleviated by the extrusion resistant inflatable tool of the invention.
In the invention, a biaxially woven sleeve is interposed between the boot/inner-tube and the ribs of a tool having otherwise conventional components. The sleeve is preferably constructed of carbon fiber, aramid fiber, fiber glass or suitable alternative fiber which provides a bridge between the ribs of the inflatable tool as the element expands into the noncylindrical environment. The existence of the biaxially woven sleeve in an annular area outside the boot and inside the ribs of the element prevents the boot from being extruded through the ribs when they open excessively during expansion into a noncylindrical borehole environment. The sleeve further prevents excessive bending of the ribs which would otherwise create difficulties in removing the tool from the downhole environment.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:
FIG. 1 is a schematic cross section of the device of the invention illustrating the position of the extrusion resistant biaxially woven sleeve;
FIG. 2 is a view of the sleeve itself illustrating the pattern thereof;
FIG. 3 is an illustration of the sleeve disposed around the rubber boot; and
FIG. 4 is an illustration of a sleeve around the rubber boot after inflation and deflation.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, one of ordinary skill in the art will recognize the typical cross section of an end assembly of an external casing packer (ECP) 10 . Within the ECP 10 , a mandrel 12 is disposed at the inside diameter of the tool. Radially outwardly of mandrel 12 is an inflatable element such as an expandable boot or inner-tube 14 , which most commonly is constructed of rubber, although other expandable materials may be employed as desired.
Located radially outwardly of boot 14 is an extrusion resistant mechanism which preferably is biaxially woven sleeve 16 , which is critical to the functionality of the invention. The sleeve 16 is interposed between the boot 14 and ribs 18 which are mounted within the outer cover 20 and end sleeve 22 of the tool of the invention. Ribs 18 are constructed and overlapped according to industry standards, known to one of ordinary skill in the art. Upon expansion of boot 14 , in a noncylindrical shaped borehole environment, ribs 18 expand beyond the intended amount and subject the tool to damage. The distorted ribs 18 , even after deflation of the inflatable tool may hinder removal of the tool from the borehole costing both time and money. The interposition of sleeve 16 , between boot 14 and ribs 18 provides an effective bridge between the ribs when they open upon inflation, which is sufficient to retain boot 14 and prevent extrusion thereof through ribs 18 . Sleeve 16 is about 18″ long and is located substantially over the intersection between end sleeve 22 and rubber outer cover 20 to prevent the deformation of ribs 18 as well as the extrusion of boot 14 .
Sleeve 16 may preferably be constructed of carbon fiber or aramid fiber (or kevlar), fiberglass or other similiar fiber material having comparable properties. It is noted that the stronger fibers, i.e. carbon, kevlar are preferred. The fibers are at an acuate angle relative to one another. The acuate angle illustrated in FIG. 2 is about 45 degrees.
In construction of the device of the invention referring to FIG. 3, the uphole end 24 of sleeve 16 is tightly wrapped about boot 14 and generally does not move from its original location. In order to allow the sleeve 16 to expand however, it is preferable to provide a friction lowering material 26 . Such material may be applied to the inflatable element or to the sleeve or both. Additionally the friction lowering material 26 could simply be dispersed between the two. Wrap boot 14 with Teflon tape or other similar friction reducing material under all but the uphole end 24 of sleeve 16 . The sleeve 16 is commercially available from A&P Technology, Covington, Ky.
FIG. 4 illustrates the condition of the sleeve after inflation of boot 14 and deflation thereof. Although damage is notable on the sleeve, it is also apparent that the boot 14 did not extrude through the ribs of the inflatable device. Thus, the construction of the device of the invention overcomes the prior art difficulty of a rubber boot being extruded through the ribs of the inflatable device during inflation in a noncylindrical borehole environment.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
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Extrusion resistant inflatable tool having a biaxially oriented woven material disposed about at least one elastomeric element of the inflatable tool and radially inwardly of a rib structure of the inflatable tool. The woven material prevents extrusion of the elastomeric element between individual ribs of the ribs structure during the inflation of the tool.
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TECHNICAL FIELD
[0001] The present invention relates to an air and gas mixing valve for a water heater, and particularly to an air and gas mixing valve for a water heater which controls the amount of gas and air supplied to the burner provided in a water heater for a more efficient control of the heat quantity.
BACKGROUND OF THE INVENTION
[0002] In general, a gas water heater system is a heating apparatus providing living convenience, such as providing hot water for washing or taking a shower by heating low temperature direct water, and is not used for heating purposes. The system consists of two methods: instantaneous gas water heater system and storage gas water heater system.
[0003] The instantaneous gas water heater system of the above methods uses instantaneous heat exchanger to instantly heat desired amount of direct water for tapping hot water, and the storage gas water heater system consists of storing hot water in a storage tank and storing it while maintaining at a constant temperature for supplying.
[0004] The two aforementioned gas water heater systems comprise a heating means for heating low temperature direct water, and the heating means supplies a gas mixture mixed in a mixing valve to a burner, the gas mixture consisting of gas that is supplied through a gas regulator and air supplied through a blower.
PRIOR ART
Patent Literature
[0005] (Patent Literature 1) Korean Patent No. 10-113502
[0006] The aforementioned patent literature is directed to a composite gas water heater system manufactured by combining the instantaneous gas water heater and storage gas water heater, thus manufacturing a gas water heater of a compact volume while at the same time allowing a stable use thereof by decreasing temperature difference of the cold water and the hot water.
[0007] In the aforementioned patent literature, air and gas is supplied to the burner ( 28 ) by passing gas, supplied through a gas regulator ( 22 ) which controls the amount of gas, through a nozzle ( 26 ) to release heat to the upper portion, as shown in FIG. 6 . At this time, the blower ( 24 ) supplies air to the burner ( 28 ), thereby increasing combustion rate of the gas.
[0008] However, aforesaid gas water heater system is simply a structure in which air and gas are mixed to be supplied to a burner. It does not include a function of controlling the amount of air and gas according to the amount of heat quantity of the burner used for heating hot water needed by the user. Thus, hot water heater needs to be manufactured according to the heat quantity, which increases the manufacturing cost.
DISCLOSURE OF INVENTION
Technical Problem
[0009] The present invention has been made to solve the above-described problem occurring in the prior art, and an object of the present invention is to provide a dual venturi with simplified structure to minimize the apparatus, high operational reliability, easy manufacturing process, and decreased manufacturing cost.
[0010] Another objective of the present invention is to provide a dual venturi which can independently control the ratio of the first-side and second-side air and gas.
Technical Solution
[0011] The first configuration of the present invention, for solving the above-described problem comprises, a tubular part, as a cylindrical duct, having primary and secondary passageways separated by an internal partition therebetween, in which a primary gas inlet is provided on the side wall of the primary passageway; a body part, located in the interior of the second passageway of the tubular part, for opening/closing the flow of secondary air by rotating in horizontal plane and vertical plane directions, the horizontal plane direction being the cross-sectional direction of the tubular part and the vertical plane direction being perpendicular to the horizontal plane; a damper part having a damper part-side secondary gas outlet; a driving part, connected to the lateral surface of the damper part via a rotational shaft, for rotationally driving the damper part in the horizontal and vertical planes; and a secondary gas inlet for introducing secondary gas into the secondary passageway of the tubular part via the damper part by means of the secondary gas inlet-side outlet, which connects selectively to the damper part-side secondary gas outlet on the basis of the rotational position of the damper part, and for forming the rotational shaft of the damper part along with the rotational shaft of the driving part.
[0012] Preferably, the driving part comprises a synchronous motor, and the rotational shaft of the driving part is the rotational shaft of the synchronous motor.
[0013] Preferably, the secondary gas inlet-side outlet is connected to the damper part-side secondary gas outlet when the body part of the damper part is vertically positioned.
[0014] Preferably, the driving part includes a limit switch for indicating the horizontal and vertical direction positions of the damper part.
[0015] Preferably, the central diameter width of the tubular part increases from the center towards the upper and lower portions.
[0016] Preferably, the damper part-side secondary gas outlet is formed on the outer surface such that it is facing the upper side of the tubular part when the body part is positioned in the horizontal direction.
[0017] Preferably, the damper part-side secondary gas outlet is formed on the outer surface such that it is facing both the upper side and the lower side of the tubular part when the body part is positioned in the horizontal direction.
[0018] Preferably, only one secondary gas inlet-side outlet is formed, which is connected to the damper part-side secondary gas outlet when the damper part is vertically positioned.
[0019] Preferably, two secondary gas inlet-side outlets are formed, which are connected to the damper part-side secondary gas outlet when the damper part is vertically positioned.
Advantageous Effects
[0020] The following advantageous effects can be obtained through the present invention having the above configurations.
[0021] First, the inner portion of the tubular part is partitioned to form a primary passageway and secondary passageway. The air ratio of the first-side flow and second-side flow can be easily regulated since only the primary air and primary gas flow through the primary passageway and only the secondary air and secondary gas flow through the secondary passageway.
[0022] Second, opening on one-side of the secondary gas inlet is set as the secondary gas outlet, such that the secondary gas outlet is opened/closed simultaneously with opening/closing to the secondary air passageway via the rotation of the damper part. Thus, the structure is very simplified.
[0023] Third, the motor rotational shaft and the cylindrical gas inlet is used as the rotational shaft of the damper part, thus it is not necessary to install a separate rotational shaft. Further, the rotation of the damper part opens/closes the outlet of the stopped secondary gas inlet, thereby increasing operational reliability in addition to the simple structure thereof.
[0024] Fourth, generally a widely used ventilation facilities can be used for the damper part, allowing simple manufacturing process. Further, a synchronous motor can be used to directly connect the damper part to the rotational shaft of the motor of the driving part, thus additional elements such as a wire or a spring are not required, resulting in more simplified structure, and the overall volume is decreased.
[0025] Fifth, based on the first to fourth reasons above, simplification of the structure and decreased manufacturing costs can be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an exploded perspective view showing the dual venturi according to the first embodiment of the present invention.
[0027] FIG. 2 a shows an embodiment of the present invention, that is a longitudinal sectional view of the dual venturi with the damper part in a closed state; and FIG. 2 b is a longitudinal sectional view showing the dual venturi with the damper part in an open state.
[0028] FIG. 3 a , FIG. 3 b and FIG. 3 c show an embodiment of the present invention, that is a diagram showing the damper part in the closed state. FIG. 3 a is a perspective view of the dual venturi, FIG. 3 b is a planar sectional view of the dual venturi and FIG. 3 c is a sectional view showing the positional relationship between the secondary gas inlet and the secondary gas outlets of the damper part.
[0029] FIG. 4 a and FIG. 4 b show an embodiment of the present invention, that is a diagram showing the damper in the open state. FIG. 4 a is a planar sectional view of the dual venturi and FIG. 4 b is a sectional view showing the positional relationship between the secondary gas inlet and the secondary gas outlets of the damper part.
[0030] FIG. 5 a and FIG. 5 b show the positional relationship between secondary gas inlet-side secondary gas outlet and the damper part at the limit switch of the driving part. FIG. 5 a is a planar view of the limit switch and FIG. 5 b is a lateral view of the limit switch.
[0031] FIG. 6 is a drawing showing prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] Hereinafter, the first embodiment of the present invention will be described with reference to the accompanying drawings.
[0033] First, the overall structure of the dual venturi is explained with reference to FIG. 1 , FIG. 2 a and FIG. 2 b . FIG. 1 is an exploded perspective view defining the dual venturi according to an embodiment of the present invention, FIG. 2 a shows an embodiment of the present invention, that is a longitudinal sectional view of the dual venturi with the damper in a closed state, and FIG. 2 b is a longitudinal sectional view showing the dual venturi with the damper in an open state, respectively.
[0034] The dual venturi according to the present invention comprises a tubular part ( 40 ) having a primary passageway ( 43 ) and a secondary passageway ( 44 ) separated by a partition ( 47 ) therebetween (Refer to FIGS. 2 a and 2 b ), with a primary gas inlet ( 45 ) provided on the center of the side wall of the primary passageway ( 43 ); a damper part ( 20 ) formed on the tubular part ( 40 ) for opening/closing the secondary passageway ( 44 ) which forms the secondary air passageway extending in the direction from the lower portion to the upper portion of the tubular part ( 40 ); a driving part ( 10 ) connected to the lateral surface of the damper part ( 40 ) and inserted via the tubular part side second hole ( 42 ), resulting in the rotational shaft ( 15 ) of the motor to be connected to the damper part-side first hole ( 23 ) to rotationally drive the damper part ( 20 ); and a secondary gas inlet ( 60 ) inserted through the first hole ( 41 ) of the tubular part ( 40 ), and then passing through the primary passageway ( 43 ) and the partition ( 47 ) to connect to the damper part-side second hole ( 27 ) (Refer to FIG. 3 c ) within the secondary passageway ( 44 ), thereby supplying secondary gas via the damper part ( 20 ). In this manner, the tubular part ( 40 ) allows only the primary air and primary gas to pass through the primary passageway ( 43 ) separated by the partition ( 47 ), and allows only the secondary air and secondary gas to pass through the secondary passageway ( 44 ), to effectively regulate the air-gas ratio of the primary mixed airflow and secondary mixed airflow.
[0035] As illustrated in FIG. 1 , the tubular part ( 40 ) has a central diameter that is smaller than the diameter of both ends of the higher and lower portions, thus the central passageway is narrowly formed. This configuration can be more clearly understood from FIG. 2 a and FIG. 2 b . However, the shape of the tubular part ( 40 ) can be a cylindrical shape with equal upper and lower portions, and the present invention is not particularly limited to this shape.
[0036] The damper part ( 20 ) comprises an overall semicircle shaped body part ( 29 ), which has a horizontal area that can block the secondary passageway ( 44 ) of the tubular part ( 40 ), the upper surface of the body part ( 29 ) being provided with a damper part-side secondary gas outlet ( 22 ) having four slot-type holes through which secondary gas is discharged. The body part ( 29 ) corresponding thereto can also have a secondary gas outlet. That is, it can also be formed on the corresponding lower portion of the secondary gas outlet ( 22 ). Further, four slot-type holes are shown, but the number of the slot-type holes can be suitably selected according to need, and its shape can also be varied.
[0037] As shown in FIG. 2 a and FIG. 2 b , end part of the secondary gas inlet ( 60 ) in contact with the damper side ( 20 ) is closed by the damper part.
[0038] The secondary gas inlet ( 60 ) is cylindrically shaped, and is connected to the damper part-side second hole ( 27 ) (Refer to FIG. 3 c ) within the second passageway ( 44 ) via insertion through the tubular part-side first hole ( 41 ), the primary passageway ( 43 ) and the partition ( 47 ). Here, the secondary gas inlet ( 60 ) does not rotate but the damper part ( 20 ) can, thus the secondary gas inlet ( 60 ) also functions as a stationary shaft to rotate the damper part ( 20 ) together with the rotational shaft ( 15 ) of the motor. The damper part-side portion of the secondary gas inlet ( 60 ) becomes a closed state as defined above, and a secondary gas inlet-side secondary gas outlet ( 62 ) having an identical shape to the damper part-side secondary gas outlet ( 22 ) is formed on the circumference of the area near the damper part-side of the secondary gas inlet ( 60 ). The secondary gas inlet-side secondary gas outlet ( 62 ) is also symmetrically shaped and can form outlets on both sides of the pipe or form an outlet only on one side. FIG. 2 a illustrates a closed state of the damper part ( 20 ), that is the state in which the upper and lower passageways of the secondary passageway ( 44 ) of the tubular part ( 40 ) are blocked and only the primary passageway ( 43 ) of the damper part ( 20 ) is used as the passageway for the primary air and primary gas of the tubular part ( 40 ) to pass through. In other words, the state in which the damper part ( 20 ) is placed in the cross-sectional direction, that is the horizontal plane of the tubular part ( 40 ), only the primary gas inlet ( 45 ) is open towards primary passageway of the tubular part ( 40 ) (maintains an open state at all times), and the secondary gas inlet-side secondary gas outlet ( 62 ) is closed.
[0039] FIG. 2 b illustrates opened state of the damper part ( 20 ), that is the state in which the upper and lower passageways of the tubular part ( 40 ) are open, thus most of the primary passageway ( 43 ) as well as the secondary passageway ( 44 ) of the tubular part ( 40 ) is substantially used as the air passageway, the so-called secondary air passing state. Here, the damper part ( 20 ) is placed in the vertical plane that is perpendicular to the horizontal plane, and the primary gas inlet ( 45 ) as well as the secondary gas inlet-side secondary gas outlet ( 62 ) are both open towards the damper part-side secondary gas outlet ( 22 ). As a result, all functions of the first step distribution and second step distribution can be executed.
[0040] Hereafter, operation of the dual venturi according to an embodiment of the present invention will be described in detail with reference to FIG. 3 a to FIG. 5 b . Parts not thoroughly explained in the above detailed description will be explained through the additional configuration.
[0041] First, FIG. 3 a , FIG. 3 b and FIG. 3 c show an embodiment of the present invention, that is a diagram showing the closed state of the damper part ( 20 ). FIG. 3 a is a perspective view of the dual venturi, FIG. 3 b is a planar sectional view of the dual venturi and FIG. 3 c is a sectional view showing the positional relationship between the secondary gas inlet and the secondary gas outlets of the damper part.
[0042] As shown in the perspective view of FIG. 3 a , when the damper part ( 20 ) is closed, the positional relationship between the tubular part ( 40 ) and the damper part ( 20 ) is equal to when the damper part ( 20 ) blocks the entire upper and lower air passageways of the secondary passageway ( 44 ) of the tubular part ( 40 ), and only the primary passageway ( 43 ) substantially becomes the air passageway (primary air passageway) of the tubular part ( 40 ). In other words, the damper part ( 20 ) is placed in the horizontal plane in the cross-sectional direction of the tubular part ( 40 ), and at this time, as shown in FIG. 3 b , only the primary gas inlet ( 45 ) is open towards the tubular part ( 40 ) side (open at all times) so that primary gas flows through the tubular part ( 40 ), and the secondary gas inlet-side secondary gas outlet ( 62 ) is blocked by the wall of the damper part-side second hole ( 27 ) and thus closed, as shown in FIG. 3 c . That is, a small quantity of relatively low level primary air and primary gas flow through the primary passageway ( 43 ) of the tubular part in the closed state.
[0043] FIG. 4 a and FIG. 4 b show an embodiment of the present invention, that is a diagram showing the open state of the damper part. FIG. 4 a is a planar sectional view of the dual venturi and FIG. 4 b is a sectional view showing the positional relationship between the secondary gas inlet and the secondary gas outlets of the damper part.
[0044] As shown by the sectional view of FIG. 4 a , when the damper part ( 20 ) is opened, the positional relationship between the tubular part ( 40 ) and the damper part ( 20 ) is equal to the substantially opened state of the entire upper and lower air passageways of the tubular part ( 40 ) via the opening of the secondary passageway ( 44 ). In other words, the damper part ( 20 ) is placed upright in the vertical direction to the horizontal plane in the closed state, that is the vertical plane to the cross-sectional direction of the secondary passageway ( 44 ) of the tubular part ( 40 ). At this time, as shown in FIG. 4 a , the primary gas flows through the primary gas inlet ( 45 ) and also the secondary gas inlet-side secondary gas outlet ( 62 ) is opened to let the secondary gas flow out of the secondary passageway ( 44 ).
[0045] Referring to FIG. 4 b , the secondary gas inlet-side secondary gas outlet ( 62 ) and the damper part-side secondary gas outlet ( 22 ) formed on the wall of the damper part-side second hole ( 27 ) correspond to each other and thereby are connected.
[0046] In this embodiment, the secondary gas inlet-side secondary gas outlet ( 62 ) is formed only on one part of the circumference diameter such that only one lateral surface (for instance, the upper direction-side surface of the upper and lower directions of the tubular part ( 40 )) of the damper part ( 20 ) releases secondary gas. However, for instance, the secondary gas inlet-side secondary gas outlet ( 62 ) can be installed on the opposite side (that is, 180°) of the cylindrical secondary gas inlet ( 60 ) wall circumference to release secondary gas in the upper and lower directions of the damper part ( 20 ).
[0047] FIG. 5 a and FIG. 5 b show the positional relationship between the secondary gas outlet of the secondary gas inlet and the damper part at the limit switch of the driving part. FIG. 5 a is a planar view of the limit switch and FIG. 5 b is a lateral view of the limit switch, respectively.
[0048] In the limit switch ( 11 ) shown in FIG. 5 a , reference signs 211 a and 211 b show the position points of the damper part-side secondary gas outlets, 211 c and 211 d respectively show the position points of the secondary gas inlet-side secondary gas outlets, 211 g shows the damper part-side positional probe, and 211 h shows the secondary gas inlet-side positional probe, respectively. One of the damper part-side secondary gas outlet position points ( 211 a )( 211 b ) is positioned at the damper part-side positional probe ( 211 g ), and in the same manner if one of the secondary gas inlet-side secondary gas outlet position points ( 211 c )( 211 d ) corresponds to the secondary gas inlet-side positional probe ( 211 h ), secondary air and secondary gas are blocked, as shown in FIG. 3 c . That is, it shows the state in which the damper part ( 20 ) is at the horizontal position.
[0049] Further, on the contrary, if one of the secondary gas inlet-side secondary gas outlet position points ( 211 c )( 211 d ) corresponds to the damper part-side positional probe ( 211 g ), and at the same time one of the damper part-side secondary gas outlet position points ( 211 a )( 211 b ) is positioned at the secondary gas inlet-side positional probe ( 211 h ), the secondary air and secondary gas are open to flow through the tubular part ( 40 ), as shown in FIG. 4 a . That is, this shows the state in which the damper part ( 20 ) is vertically positioned.
[0050] Referring to FIG. 5 b , a synchronous motor is used as the motor ( 13 ) included in the driving part ( 10 ) and the rotational shaft ( 15 ) of the direct motor ( 13 ) can be connected to the damper part-side first hole ( 23 ). Thus, components necessary for the AC motor in the prior art such as a wire, or return spring can be removed, allowing the dual venturi of the present invention to be more simplified compared to the prior art.
[0051] The above description defines a preferred embodiment of the present invention but is not limited thereto, and various modifications and other similar embodiments are possible by the skilled person in the art. For instance, the combination of the limit switch sets the secondary gas open state as when the damper part-side probe and the secondary gas inlet-side probe positions are against each secondary gas outlet positions. However, the opposite setting may be used as long as practically identical results are obtained. Further, positions of the primary gas inlet and the partition of the tubular part may be varied according to their use, to change the flow velocity of the primary passageway and the secondary passageway. Thus, various modifications and embodiments that can be clearly expected are also within the scope of the present invention.
REFERENCE SIGNS
[0052] 10 : Driving Part, 11 : Limit Switch, 15 : Rotational Shaft of the Motor, 20 : Damper Part,
[0053] 22 : Damper Part-Side Secondary Gas Outlet, 23 : Damper Part-Side First Hole,
[0054] 24 : Damper Part-Side Sealing Hole, 27 : Damper Part-Side Second Hole, 29 : Body Part,
[0055] 40 : Tubular Part, 41 : Tubular Part-Side First Hole, 42 : Tubular Part-Side Second Hole,
[0056] 43 : Primary Passageway, 44 : Secondary Passageway, 45 : Primary Gas Inlet, 47 : Partition,
[0057] 60 : Secondary Gas Inlet, 60 : Secondary Gas Inlet-Side Outlet,
[0058] 211 a : Damper Part-Side Secondary Gas Outlet Position Point
[0059] 211 b : Damper Part-Side Secondary Gas Outlet Position Point,
[0060] 211 e : Secondary Gas Inlet-Side Outlet Position Point,
[0061] 211 d : Secondary Gas Inlet-Side Outlet Position Point, 211 g : Damper Part-Side Positional Probe,
[0062] 211 h : Secondary Gas Inlet-Side Positional Probe
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A dual venturi having a tubular part having primary and secondary passageways, wherein a primary gas inlet is provided on the side wall of the primary passageway; a body part, for opening/closing the flow of secondary air by rotating in horizontal plane and vertical plane directions, the horizontal plane direction being the cross-sectional direction of the tubular part and the vertical plane direction being perpendicular to the horizontal plane; a damper part having a damper part-side secondary gas outlet; a driving part, for rotationally driving the damper part in the horizontal and vertical planes; and a secondary gas inlet, which openly connects selectively to the damper part-side secondary gas outlet on the basis of the rotational position of the damper part, and for forming the rotational shaft of the damper part along with the rotational shaft of the driving part.
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PRIOR PROVISIONAL APPLICATION
Applicant claims the benefit of the filing date of Provisional Application Ser. No. 60/069,630, filed Dec. 15, 1997.
CROSS REFERENCE TO OTHER RELATED APPLICATIONS
This application is a continuation in part application of Ser. No. 08/956,217, filed Oct. 22, 1997, now U.S. Pat. No. 5,914,456, which, in turn, is a continuation of application Ser. No. 08/633,434, filed Apr. 17, 1996, now U.S. Pat. No. 5,837,039.
FIELD OF THE INVENTION
The present application pertains to an adsorbent package adapted for use in air conditioning accumulators and receiver dryers of the type having a fluid flow line disclosed therein that is connected to a filter or bleed nipple.
BACKGROUND OF THE INVENTION
Adsorbent packages are typically provided in automotive accumulators and receivers to dehydrate air and refrigerants. Commonly, liquid accumulators for air conditioning systems, such as automotive air conditioning systems, employ a sealed or closed canister which provides temporary storage for the refrigerant and the lubricating oil, and also provides for dehydration of the refrigerant. Typically, the liquid accumulator has a permanently sealed casing which includes a baffle which separates the liquid from the gas component, and also has a generally unshaped pick up tube or suction tube with a bight portion which has a filtered bleed opening facing the container bottom. The tube also has two legs which extend upwardly toward the baffle at the top in generally, but not necessarily, parallel relationship, one end of which is open to receive an inflow of vaporized refrigerant for delivery to the suction side of the compressor by downward flow past the bottom pick up opening.
One or more desiccant packages are normally carried on or mounted on this u-shaped tube with portions extending from the filtered pick up opening upwardly along the generally parallel portions of the tube extending from the bight. The desiccant package is inserted and sealed within the accumulator prior to its permanent assembly. Accumulators of this general kind are shown in the U.S. patents of Livesay, 4,291,548 of Sep. 29, 1981, and Kisch 4,496,378 of Jan. 29, 1985. In some cases, the adsorbent package is mounted directly to the filter.
There is a need in the art to provide a stable mounting of the adsorbent package so that it will not become misaligned or dislodged during use. Such actions could block the filter or result in positioning of the adsorbent packet in the sump area of the accumulator.
In many current accumulator structures, the filter is provided as part of a plastic snap on assembly wherein a mounting ring or clasp grasps the fluid flow tube to provide a mount for the filter. Due to excessive vibration during use, abrasion of the normally fibrous pouch along this ring or clasping mechanism could result in tearing or complete rupture of the package, spilling the contents of the package into the accumulator sump area.
Also worth mentioning is the need for the provision of a nesting area that extends along the adsorbent package in generally parallel relation to the bight tube of the accumulator. This nesting area helps to ensure stable mount of the adsorbent package in the accumulator.
SUMMARY OF THE INVENTION
The above noted concerns and needs are addressed by the single, unitary adsorbent package in accordance with the invention. Briefly, the adsorbent material package of the present invention comprises a sole elongated pouch like material adapted for filling with desiccant or other adsorbent medium therein. A centrally located aperture is provided in the package and is surrounded by an annularly shaped rigid zone defining a heat or ultrasonic seal of the top surface of the package with the bottom package surface to thereby form a rigid mounting zone. The package opening is force or snap fit over a flange or the like associated with the bleed filter that is in turn connected to the bight tube of the accumulator. In normal accumulator structures, the bight tube is oriented transversely with regard to the longitudinal axis of the cylindrical housing and connects upwardly extending fluid flow tubes.
A longitudinally disposed seam member is formed along the length of the top or bottom side of the adsorbent pouch. This seam includes a double fabric layer area and may be formed via conventional means such as heat sealing, ultrasonic sealing, or other electronic sealing or fusing means. This longitudinally extending zone provides a reinforced area of the pouch that is adapted for positioning adjacent a ring like mounting clamp or the like which latter structure is commonly used to detachably mount a plastic filter to the bight tube portion.
In another aspect of the invention, a pair of rigid shoulder members is formed in the unitary pouch. Each of the shoulder members extends from one of the width wise ends of the pouch towards the central opening. These rigid shoulders are generally flat and, together with the centrally disposed opening and its surrounding flat rigid member, define a nesting surface extending transversely across the length of the pouch. This nesting surface is adapted for reception of the bight tube therein.
Preliminary indications find that it is best to provide an aperture diameter in the package of from about 0.8-0.9 based upon the outside diameter of the filter flange.
The invention will be further described and illustrated in conjunction with the following detailed description and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut away view of an accumulator incorporating a unitary adsorbent material package in accordance with the invention;
FIG. 2 is a cross-sectional view of the accumulator and adsorbent material package and accumulator fluid flow conduits taken along the plane represented by the lines and arrows 2--2 of FIG. 1;
FIG. 3 is a bottom plan view of an adsorbent material package in accordance with the invention;
FIG. 4 is a top plan view of the adsorbent material package shown in FIG. 3;
FIG. 5 is another cut away view of the accumulator and adsorbent package shown in FIG. 1 rotated 90° from the position shown in that figure with the accumulator housing omitted for better clarity;
FIG. 6 is a magnified cut away view of the section of the assembly taken along the plane represented by the lines and arrows 6--6 of FIG. 1 with the exception that the lateral ends of the package have been moved downwardly as shown by the arrows to better illustrate the mounting of the adsorbent packet over the filter flange; and
FIG. 7 is a cut away view of an accumulator top incorporating another embodiment of an adsorbent material package in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning first to FIG. 1 of the application, there is shown an accumulator 2 of the general type shown and described in U.S. Pat. No. 4,474,035; the disclosure of which is incorporated by reference herein. The accumulator comprises a generally cylindrical housing 4 having a bottom wall 6 leading to a sump area 8. Upstanding fluid flow tubes 10, 12 are provided in the accumulator. A baffle 14 shields direct entry to fluid flow tube 10 as set forth in the aforementioned --035 patent. The fluid flow tubes 10, 12, are connected via a transversely oriented bight tube 16 (see FIGS. 2 and 6).
As per typical operation, inlet bore 100 is in communication with the outlet conduit from an evaporator or the like, with the outlet bore 102 and communicating fluid flow conduit 12 communicating with the suction or inlet side of a compressor unit.
As shown, a sole adsorbent packet 20 is provided toward the bottom of the accumulator, but does not extend into the sump area. In accordance with normal operation, the adsorbent package comprises desiccant or the like material therein that is adapted to dehydrate the fluid medium flowing through the accumulator. Also, a small amount of lubricating oil or the like injected into the system is aspirated into the suction side of the compressor through a filter housing 22 depending from the bight tube 16. The filter comprises a filter medium 23 and support flange 24.
Turning now to FIGS. 3 and 4 there is shown an adsorbent packet 20 in accordance with the invention. First, looking at FIG. 3 specifically, the back side or surface 42 of the packet is shown. Here, the elongated packet material comprises end seams 46, 48, sealing the respective longitudinal ends of the package. A longitudinally extending seam 44 extends longitudinally along the length of the elongated packet and slightly laterally offset from a longitudinally extending bisector line extending through the package. This seam 44 provides a double thickness of the felt like material used to form the packet 20 and therefore can be referred to as a reinforcement area. A circularly cross-sectioned aperture 60 is formed in the middle of the packet and is provided with a rigid heat or ultrasonically fused zone 62 surrounding the aperture. Shoulder members 50, 52 are laterally offset from the aperture 60 and provide rigid, flat surfaces which help aid in the stability of the mounting of the packet to the accumulator tube assembly as will be hereinafter explained in greater detail. The shoulders are defined by fused top and bottom surfaces of the packet. Tuck or fold sections 70, 82, 84 and 74 are disposed along the first widthwise edge of the pouch with tuck or folds 72, 86, 88, 76 provided in the opposing or second widthwise edge to define the pouch.
Although a generally circular aperture is shown in the drawings, the aperture may comprise any one of a myriad of possible cross sectional shapes such as a rectangle, triangle, parallelogram, rhombus, etc. The key criteria is that the aperture should snap or friction fit over the filter flank.
FIG. 4 depicts the top side or surface 64 of the packet 20. Here, aperture 60 is provided with rigid surrounding zone 62. Zone 62 provides a shoulder which will be snap mounted to the filter support flange 24.
The packet is formed from a fibrous, air permeable material such as a synthetic felt material. Polyester felts are presently preferred but other synthetic and natural felts can of course be employed. Turning now to FIGS. 5 and 6, there is shown bight tube 16 with filter housing 22 depending therefrom. The filter is clasped to the bight tube by means of the mounting ring 90 and associated clasp. The aperture 60 is firmly, frictionally received over the support flange 24 of the filter. The opposed lateral sides 201, 202 of the unitary packet will be moved upwardly, against the direction of the arrows (shown in FIG. 6), for proper insertion into the accumulator housing.
The pair of shoulders 50, 52 (see also FIG. 2) along with the rigid collar 62 surrounding the aperture, comprise a centrally located zone that extends transversely across the length of the packet. This zone provides a rigid, generally flat mounting area for congruent mounting of the bight tube portion therein. This helps provide stability for the adsorbent package during strenuous use conditions commonly encountered. Additionally, and as can be seen best in FIG. 2, the longitudinal seam 44 is parallel and adjacent to the mounting ring 90 of the filter assembly. Due to the rigid nature of the longitudinal seam, this helps to provide increased abrasion resistance of the felt packet in a location in which the ring may tend to shear or rub the packet.
It is therefore apparent that in accordance with the invention, an opening is provided in the unitary package that is snap fit over the filter housing. The opening is surrounded by an annularly shaped rigid zone so as to help maintain stability of the packet over the filter flange. Presently, the diameter of the package aperture 60 is formed so that it is about 0.8-0.9 of the diameter of the flange. One successfully employed package has provided an aperture 60 diameter of about 0.85-0.86 of the flange outside diameter dimension.
In order to make the packet 20 of the present invention, a tubular felted material, as previously described is first provided. The bottom of the pouch like material is then sealed via heat seal, or other electronically sealing system, with ultrasound sealing being preferred. Then, one half of the desired desiccant is filled into the pouch. Appropriate tucks are made in the pouch by holding the desired pouch portions in place by elongated fingers or the like and ultrasonic sealing of the area. The shoulder members and solid rigid zone 62 are then formed via ultrasonic sealing with the second half of the pouch then being filled with desiccant. The top longitudinal edge of the pouch is then sealed so as to provide a sealed packet. At the same time the bottom half of the next succeeding bag in the production run is sealed and the procedure repeated so that successive bags can be made. After each bag is cut, the central aperture 60 is cut in the middle of the zone 62.
FIG. 7 shows another version of the invention wherein a smaller packet 220 is shown for those cases in which only about 40-50 grams of desiccant is needed. In this figure, the top half 322 of the accumulator housing is shown. This half will be welded or otherwise sealed to a bottom assembly to form the general accumulator housing structure shown in FIG. 1.
Similar to FIG. 1, fluid tubes 210, 212 are connected via a transversely oriented bight section with an aspirator filter housing secured to the bight tube via a ring shaped clasp (not shown). The packet 220 comprises end seams 246, 248 and an aperture 260 provided along one of the longitudinal packet end regions.
The aperture 260 is surrounded by a rigid collar 262 to facilitate snap mount of the packet over the filter flange 224. Similar to the previously described embodiment, a longitudinally extending seam 244 provides a reinforced area that is adapted for positioning adjacent the mounting clasp used to affix the filter to the fluid flow tube.
The provision of a single packet for reception of desiccant therein not only reduces the number of seams and therefore potential rupture sites, but also leads to decreased production time. Additionally due to elimination of connecting seams between bags and the attendant reduced volume areas adjacent these seams, it is possible to place more adsorbent per unit packet length into the single bags in accordance with the invention, thereby shortening the bag's overall length which aids the process of assembling and welding the accumulator can.
While the forms of apparatus herein described constitute specific embodiments of this invention, it is to be understood that the invention is not limited to these particular embodiments, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.
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An adsorbent package is provided for mounting to a filter or bleed nipple that is, in turn, attached to a bight tube or other fluid flow conduit in an auto or truck accumulator or receiver dryer. In a preferred form of the invention, a centrally disposed opening is provided in the adsorbent package and is surrounded by a rigid collar. The aperture is dimensioned so that it will be force or snap fit over a flange or the like on a filter.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an automatic transport system for transporting articles by an automatic transport vehicle at an assembly location in a plant and the like without human attendance, and particularly to an automatic transport system which detects by a sensor an obstruction located ahead of the automatic transport vehicle in its moving direction to control the operation of the automatic transport vehicle.
[0003] 2. Description of Related Art
[0004] Automatic transport vehicles (hereinafter referred to as vehicles) are advantageously used in transporting parts in an assembly process in a plant and the like. Particularly, in a manufacturing semiconductor process, vehicles are used in transferring and assembling semiconductor wafers in the clean room without human intervention for preventing the contamination with dust and the like. For example, an Overhead Hoist Transport vehicle (hereinafter referred to as “OHT vehicle”), which travels along a ceiling rail in the clean room is used in the assembly process of semiconductor wafers and the liquid crystal devices.
[0005] Moreover, an optical beam reflection sensor (hereinafter referred to as “optical sensor”) such as an infrared type sensor, serving as a non-contact obstruction detecting apparatus of vehicles. The optical sensor detects an obstruction ahead in the moving direction by emitting an optical beam which is conical-shaped. If a long range detection sensor is provided at the front of the vehicle as a front detection sensor, the vehicle is stopped when the long range detection sensor is triggered while it is traveling. If a vehicle has two front detection sensor as a front detection sensor, detection may be carried out in two steps by two front detection sensors.
[0006] [0006]FIG. 9 is an operation conceptual view of an OHT system used in the semiconductor wafer manufacturing process or the like. The right portion of FIG. 9 is a side view of an OHT vehicle and the left portion of FIG. 9 is a view showing a projection of the OHT vehicle ahead in the moving direction at a predetermined position in the moving direction.
[0007] In FIG. 9, a rail 21 is laid down on a ceiling of a clean room (not shown) along the process line, and a part of the rail 21 is shown therein. An OHT vehicle 22 movably hangs on a lower portion of the rail 21 . For example, the OHT vehicle 22 is constituted such that it has a box-like frame and can hold a wafer cassette 23 in this frame and runs along the rail 21 .
[0008] Moreover, a front detection sensor 24 is attached to the front portion of the OHP vehicle 22 in the moving direction. As the front detection sensor 24 , an optical sensor of such as an infrared sensor is generally used such that an obstruction in the moving direction of the OHT vehicle 22 can be detected in a non-contact state. In other words, an obstruction ahead is detected by optical beams emitted in a conical shape from the front detection sensor 24 . Then, when the front detection sensor 24 detects the obstruction ahead, the OHT vehicle 22 is designed to automatically stop.
[0009] Additionally, in FIG. 9, although the front detection sensor 24 at the left side surface of the OHT vehicle 22 is provided for movement to the left side of the figure, the OHT vehicle 22 normally moves in two directions. In such a case, the front detection sensor 24 IS also provided at the right side surface of the OHT vehicle 22 .
[0010] However, in some cases, an associated manufacturing apparatus may be present very close to the periphery of the rail 21 , the door of the manufacturing apparatus may be opened, or parts being processed are located close to the periphery of the rail 21 . Further, in other cases, in locations outside of the passage of the OHT vehicle 22 , there may be a stepladder, a workbench or the like for maintenance, or a person. For this reason, in order to prevent the OHT vehicle 22 from colliding with them, the front detection sensor 24 on the OHT vehicle 22 detect obstructions ahead. However, as shown in FIG. 9, if the detection area of light emitted from the front detection sensor 24 is widened as shown in a detection area A in order to detect obstructions located in the passage area of the OHT vehicle 22 , there is a possibility that objects which are at the periphery of the running path will unnecessarily be detected and that the OHT vehicle 22 will not run.
[0011] In other words, the left side of the drawing indicates the passage area C of the OHT vehicle 22 , as seen from the front of the OHT vehicle 22 in the moving direction, by a solid line. Also, a wide detection area A where the entire passage area C of the OHT vehicle 22 can be detected is indicated by a broken line. This large detection area A is the bottom surface of the cone of the light beam emitted by the front detection sensor 24 at a predetermined position.
[0012] Unlike the wide circular detection area A that is the bottom of a conical surface, if the front shape of the OHT vehicle 22 that is the passage area C of the OHT vehicle 22 is rectangular, for example, as illustrated in the figure, excess detection area D, in which the wide detection area A lies outside of the passage area C to be detected will occur. If an object is located in this excess detection area D, the OHT vehicle 22 will stopped even though the object is not actually obstructing the passage of the OHT vehicle 22 .
[0013] On the other hand, if the detection area is narrowed as in the narrow detection area B indicated by a broken line, the corner portions of the passage area C of the OHT vehicle 22 cannot be detected, and form a non-detection area E. In such a case, there is the concern that the OHT vehicle 22 will collide with an object in the non-detection area E which is in the corner portion of the vehicle, when the vehicle passes the object.
[0014] [0014]FIG. 10 is an explanatory view showing the front detection sensor of the OHT vehicle 22 and an example of an obstruction. As illustrated in this figure, a stepladder 25 is placed in front, in the moving direction, of the OHT vehicle 22 . In this case, if the detection area at the front detection sensor 24 is wide, as in the wide detection area A, the stepladder 25 is detected as an obstruction and the OHT vehicle 22 is stopped even though the OHT vehicle 22 will not collide with the stepladder 25 . Furthermore, if the detection area is narrowed as in the narrow detection area B, the stepladder 25 is not detected. However, if workpieses or the like are placed at a location very close to the OHT vehicle 22 , there is the concern that the OHT vehicle 22 will collide with them and break them since they cannot be detected.
[0015] [0015]FIG. 11 is a conceptual view showing an OHT vehicle used in a semiconductor manufacturing apparatus. As illustrated in this figure, for example, in the apparatus for manufacturing a 300 mm wafer, a distance P between the end surface of the OHT vehicle 22 that transports the wafer and the front surface of the semiconductor manufacturing apparatus 26 is set to about 30 mm on the basis of a standard distance. It is assumed that working is carried out in such small distances. If the detection area is too wide, the front detection sensor 24 will detect the door of the semiconductor manufacturing apparatus 26 , so that the OHT vehicle 22 will not operates well and workcannot be carried out. Moreover, if the detection area is narrowed, there is the concern that the corner of the OHT vehicle 22 will contact semiconductor wafers (not shown) mounted on the semiconductor manufacturing apparatus 26 and these semiconductor wafers will be broken.
[0016] [0016]FIG. 12 is a conceptual view showing a vehicle using two front detection sensors for long range and medium range detection. The vehicle 111 is provided with a medium range detection sensor (not shown) which can detect over a medium detection range 113 and a long range detection sensor (not shown) which can detect over a long detection range 112 . The vehicle 111 detect an obstruction which is loaded ahead in moving direction by switching the respective sensors. Then, control is performed so that the speed of the vehicle 111 is reduced when the long range detection sensor works and makes a detection within the long detection range 112 and the vehicle 111 is stopped when the medium range detection sensor makes a detection in the medium detection range 113 .
[0017] [0017]FIG. 13 is a conceptual view showing an example of the operation state of a plurality of vehicles in a general OHT system. This figure is a conceptual view to explain a system in which a transport apparatus comprising a plurality of vehicles operating between the assembly apparatuses such as a plurality of semiconductor manufacturing apparatuses. In this figure, a rail 124 is provided along a plurality of assembly apparatuses 121 , 122 , 123 , and a plurality of vehicles 125 and 126 travel on the rail 124 . Then, in the case of operating the transport apparatus comprising a plurality of vehicles 125 and 126 which detect an obstruction which is located ahead by the front detection sensor as shown in FIG. 12, described above, it is effective for the respective vehicles 125 and 126 to made to be as close as possible to the vehicle in front when stopping in order to increase the transport efficiency of the system.
[0018] The transport efficiency of the transport system largely differs depending on whether the trailing vehicle 126 can move to a position G or only to a position H when the front vehicle 125 is placed at a position F as shown in FIG. 13. For example, it is assumed that there are requests for transfer from transfer ports 127 at positions F and G simultaneously in the assembly apparatus 121 . If the trailing vehicle 126 can move to the position G when the front vehicle 125 is stopped at the position F, the simultaneous transfer can be carried out at the positions F and G. However, if the trailing vehicle 126 can move to only the position H, the trailing vehicle 126 cannot move to the position G until the front vehicle 125 finishes transferring at the position F and leaves the position F. Therefore, the transfer efficiency of the trailing vehicle 126 at the position G is decreased.
[0019] On the other hand, the conventional use of the general front detection sensors is described below. Specifically, as explained in the FIG. 12, when the vehicle moves close to the obstruction, the long range detection sensor detects the obstruction located the long detection range 112 , firstly. Next, the sensor is changed to the medium range detection sensor or the detection range of the long range detection sensor is shortened to carry out the detection of the obstruction in the medium detection range 113 . In this way, the detection range of sensor is shortened in two steps, the speed of the vehicle 111 is reduced, and then the vehicle stops at a predetermined position. In order to stop a vehicle 111 moving at a high speed before colliding with an obstruction, it is necessary to allow for a braking distance to start braking. For this reason, the detection occur in two steps for the long detection range 112 and the medium detection range 113 in the operation control of the vehicle 111 .
[0020] However, in this case as described above, the front vehicle, which is regarded as an obstruction, may move forwards and is no longer regarded as an obstruction in some cases. This results in unnecessary braking, which reduces the operation efficiency of the entire OHT system. There is a method of preventing the unnecessary braking, that is to reduce the moving speed of the vehicle and to shorten the braking distance. However, this results in a reduction in the operating speed, so that the operation efficiency of the entirety of the OHT system is reduced after all.
[0021] For this reason, in the general OHT system, the speed of the vehicle is reduced in the long detection range or the medium detection range based on the detection result of the long range detection sensor, and the vehicle is stopped in the short detection range, which is very close to the front vehicle. The switching between the long detection range and the medium detection range using the long range detection sensor is generally decided based on the size of the vehicle and the speed, or the degree of the speed reduction or the like and the switching is decided such that after the operation of the long range detection sensor, the speed reduction of the vehicle and the stopping thereof are completed before the trailing vehicle contacts the obstruction. For example, when executing long range detection, the vehicle is operated if the distance between the obstruction ahead and the vehicle is 2 to 3 m. When executing medium range detection, the vehicle continues to operate when the distance between the obstruction ahead and the vehicle is 0.5 to 1.5 m. When executing short range detection, which covers shorter distances than the above, the vehicle is stopped. In this way, the distance between the obstruction ahead and the vehicle is predetermined in each detective range
[0022] If the vehicle is moving at high speed, it is necessary to reduce the detection range as little as possible after switching the detection range to the medium detection range from the long distance detection in order to stop the vehicle safely by the short range detection sensor after the operation of the long range detection sensor. However, the reduction of the detection range is limited to the braking distance of the vehicle, so that the medium detection range cannot be shortened much.
SUMMARY OF THE INVENTION
[0023] In view of the foregoing, an objective of the present invention is to provide an automatic transport vehicle providing sensors that can detect an obstruction present an area through which the automatic transport vehicle passes without losing the operation efficiency of the transport system.
[0024] Moreover, in an automatic transport vehicle comprising a plurality of vehicles, it is determined whether or not an obstacle ahead is a vehicle, and when the obstruction ahead is a vehicle, the distance up to the vehicle is shortened and the trailing vehicle is stopped, which makes it possible to improve the operation efficiency of an OHT system.
[0025] In order to solve the above-described problems and attain the above described objectives, the present invention provides an automatic transport system for transporting articles, comprising a front detecting device which detects an obstruction in a non-contact state in an area through which an automatic-transport vehicle passes, and a projection surface of said automatic transport vehicle, and when said front detecting device detects the obstruction in said area, the running speed of said automatic transport vehicle is reduced or said automatic transport vehicle is stopped.
[0026] Since the front detecting device of the present invention detects an obstruction which is located only the vehicle pass area of the actual passage region of the automatic transport vehicle. Therefore, in this transport system, only an object which located in the vehicle pass area is detected, and parts or the like in a position very close to a vehicle, but which does not impede the running of the vehicle, are not detected. In an automatic transport system, which is used in the assembly process of a semiconductor manufacturing apparatus, it is necessary to transport the workpieces or the like in the extremely narrow range to run the automatic transport vehicle. For this reason, the use of the automatic transport system of the present invention further improves the work efficiency.
[0027] Moreover, according to the automatic transport system, in the above-described invention, said front detecting device is an optical sensor, which emits an optical beam so as to irradiate an entire outer periphery of a projection surface of said automatic transport vehicle, and said optical sensor detects an obstruction in said area. Then, only the outer periphery of the area where the automatic transport vehicle passes is irradiated with the optical beam to detect the reflected light of this optical beam, making it possible to easily carry out detection in only the passage area of the automatic transport vehicle.
[0028] Furthermore, according to the automatic transport system of the above-described invention, a plurality of said optical sensors are provided near the outer periphery of a front surface of said automatic: transport vehicle, said optical sensors respectively emit the optical beams that irradiate a area throughout an entire outer periphery of the projection surface of said automatic transport vehicle, and said optical beams are fan-shaped.
[0029] The plurality of optical sensors are provided near the outer periphery of a front surface of the automatic transport vehicle in the moving direction. Then, the entire outer periphery of the running area is irradiated in the shape of a strip with the optical beams emitted from the respective optical sensors. As a specific method, for example, in the case of the automatic transport vehicle whose front surface in the moving direction is rectangular, if the strip slits are provided along the respective sides of the rectangle and the optical beams are emitted from the interior of these slits in the shape of a fan, the entire corresponding side of the rectangle, which is equivalent to a passage area, is irradiated with the optical beams. Therefore, the strip irradiation areas of the respective sides are combined with one another, making it possible to irradiate the outer periphery of the entire vehicle moving area the shape of a strip with the optical beams.
[0030] Moreover, according to the automatic transport system in the above-described invention, wherein the area irradiated by said optical beams lies partially outside of the outer area of said projection surface. Then, it is desirable that a slight allowance be provided in the width of the detection area such that erroneous detection of obstacles and a miss of detection can be prevented by mechanical shifts occurring when the automatic transport vehicle moves.
[0031] Still further, according to the automatic transport system of the present invention, the automatic transport vehicles constituting the automatic transport system of earn invention as-described above can be used in precision work, such as in a semiconductor manufacturing apparatus, and it can be employed in an Automatic Guided Vehicle (hereinafter referred to as “AGV”) running on the floor, a Rail Guided Vehicle (hereinafter referred to as “RGV”) running on a rail on the floor, which transport materials, parts, products or the like in automated plants or the like, other than an OHT, which runs on a ceiling rail.
[0032] The automatic transport system of the present invention is an automatic transport system, which comprises a plurality of vehicles running on a rail. The vehicles detect obstructions ahead in the moving direction and whether or not the obstruction is an automatic transport vehicle that runs in the front, so as to perform running control. According to the automatic transport system of the present invention, the running control differs depending on whether the obstruction ahead is a vehicle, and if the obstruction ahead is the vehicle, the vehicle is moved forward as much as possible to improve the entire transportation efficiency. In addition, the rail to which the present invention refers is not limited to a rail whose running route is physically constrained and the like. For example, a running route that runs on the floor and the like are also included therein.
[0033] Furthermore, according to the automatic transport system of the present invention, in the above invention, each of said plurality of vehicles comprises front detecting device for detecting whether at least two kinds of obstructions are present ahead and obstruction determining device which determine whether the obstructions detected by the detecting of the front detecting device are vehicles running ahead, and running control of the vehicles is performed based on the detection result of the front detecting device and the identification result of the obstruction determining device.
[0034] According to the automatic transport system of the present invention identification of whether an obstruction ahead is not a vehicle or is a vehicle running ahead is correctly performed. Then, the stopping of the trailing vehicle or the effective forward movement are carried out based on the identification result. This makes it possible to further improve the productivity of the entire system as compared with the conventional OHT transport system. Thus, running control can be carried out so that obstacles located in an area through which the vehicle passes can be detected with more reliability without losing the transportation efficiency of the system.
[0035] Still further, according to the automatic transport system of the present invention, in the above-described invention, said front detecting device comprises a long range detection sensor which detects an obstruction located in a long range, and a short range detection sensor which detects an obstruction located in a short range, said obstruction determining device determines whether or not an obstruction ahead detected by said long range detection sensor is an automatic transport vehicle running ahead, and running control of said automatic transport vehicle is performed based on a detection result of said long range detection sensor, an determining result of said obstruction determining device, and detection result of said short range detection sensor.
[0036] According to the automatic transport system of the present invention, the long range detection sensor, which has a relatively long detection range, detects obstructions, and the obstruction determining device identifies whether the detected obstruction is a vehicle. Then, the short range detection sensor, which has a short detection range, performs the stopping of the vehicle and control of the speed reduction based on the identification result of whether or not the detected obstruction is a vehicle, and on the distance to the obstruction.
[0037] In addition, according to the automatic transport system of the present invention, in the above-described invention, when the long range detection sensor detects an obstruction and the obstruction determining device identifies that the obstruction detected by the long range detection sensor is a vehicle running ahead, the vehicle moves ahead until the short range detection sensor detects the vehicle, and when the short range detection sensor detects the vehicle, the vehicle is stopped.
[0038] Still further, when the long range detection sensor detects an obstruction and the obstruction determining device identifies that the obstruction detected by the long range detection sensor is not a vehicle running ahead, the vehicle is immediately stopped, or when the short range detection sensor detects the vehicle, the vehicle is stopped.
[0039] According to the automatic transport system of the present invention, different and detailed operation control is performed depending on whether the obstruction ahead is a vehicle. If the obstruction ahead is a vehicle, the forward movement is effectively performed to improve the operation efficiency. Moreover, if the obstruction ahead is not a vehicle, the trailing vehicle is stopped at a safe distance and can be set to a standby state. For example, when a worker is working on the transportation rail, the worker is not erroneously recognized as a vehicle even if the worker is detected as an obstruction. For this reason, the trailing vehicle can be promptly stopped as required by the operation, which is different from the forward movement of the vehicle. As a result, the vehicle waits at a distance without approaching the worker, and this makes it possible to ease any concern that the worker may feel if the vehicle approaches the worker.
[0040] Furthermore, according to the automatic transport system of the present invention, in the above-described invention, the obstruction determining device comprises a light emitting device, which is provided at a rear portion of a vehicle running ahead, and a light receiving device, which-is provided at a front portion of a trailing vehicle. Alternatively, the obstruction determining device may comprise a reflector, which is provided at a rear portion of the vehicle running ahead, and a reflection sensor for receiving a reflected light, which is provided at a front portion of a trailing vehicle.
[0041] Still further, according to the automatic transport system of the present invention, in the above-described invention, the front detecting device is a plurality of optical sensors, which are provided over a predetermined periphery at a front portion of the vehicle, and the obstruction determining device comprises a logic circuit for signals from the plurality of optical sensors.
[0042] According to the automatic transport system of the present invention, the plurality of optical sensors are arranged around a predetermined periphery near an outer peripheral of the front surface of the vehicle in the moving direction, that is the entire periphery. Then, the entire outer periphery of the vehicle moving area is irradiated in the shape of a strip with the optical beams emitted from the respective optical sensors. As a specific method, for example, in the case of a vehicle whose front surface in the moving direction is rectangular, if the strip slits are provided along the respective sides of the rectangle and fan-shaped optical beams are emitted from these slits, the entire corresponding side of the rectangle, serving as a passage area, is irradiated with the optical beams. Therefore, the strip irradiation areas of the respective sides are combined with one another, making it possible to irradiate the outer periphery of the entire vehicle moving area in the shape of a strip with the optical beams. Additionally, if a logical calculation based on the signals from the plurality of optical sensors, for example, a logical sum, is performed, it is possible to detect that the obstruction is the vehicle only when the obstruction ahead is the vehicle.
[0043] Still further, in an automatic transport system that comprises a plurality of vehicles according to the present invention, the vehicles can be used in an AGV, RGV, or the like other than an OHT, which runs on ceiling rails.
[0044] As explained above, according to the automatic transport system of the present invention, since the automatic transport vehicle detects only substantially the area though which the automatic transport vehicle moved, only actual obstructions will be detected, without fail. There is no concern that an object or a person, which do not actually impede the running of the apparatus, will be detected, or that art obstruction will not be detected, causing unnecessary stopping and damage of objects. Therefore, the automatic transport vehicle can be run safely and efficiently, so that a safe and efficient automatic production system can be constructed.
[0045] According to the automatic transport system of the present invention, an obstruction present at in the area though which the vehicle of the moving direction will pass can be detected with more reliability without losing the transportation efficiency of the system. Also, identification of whether a obstruction ahead is a vehicle running ahead or not is correctly performed. Then, stopping of the trailing vehicle and the effective forward movement are carried out based on the identification result. This makes it possible to further improve the productivity of the entire system as compared with a conventional OHT transport system. Moreover, when a worker is working on the transportation rail, the worker is not erroneously recognized as a vehicle even if the worker is detected as an obstruction. For this reason, the trailing vehicle can be promptly stopped as required by the operation, which is different from the forward movement of the vehicle. As a result, the vehicle waits at a distance without approaching the worker, and this makes it possible to ease any concern that the worker may feel if the vehicle approaches the worker.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] For more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, in which.
[0047] [0047]FIG. 1 is an outline perspective view of an OHT vehicle according to the embodiment of the present invention;
[0048] [0048]FIG. 2 is a conceptual view showing a state in which the front in the moving direction is detected using the OHT vehicle of FIG. 1;
[0049] [0049]FIG. 3 is a perspective view showing one example of a semiconductor manufacturing apparatus using an OHT vehicle of the present invention;
[0050] [0050]FIG. 4 is a conceptual view showing a state in which a long range detection sensor and a short range detection sensor detect an implement in an OHT system of the present invention;
[0051] [0051]FIG. 5A is a view showing one example of a detection range when conical beam sensors as sensor S 1 and S 2 of FIG. 1 are used, and a view showing the detection range when the vehicle is seen from the side;
[0052] [0052]FIG. 5B is a view showing one example of a detection range when conical beam sensors as sensor S 1 and S 2 of FIG. 1 are used, and a view showing the detection range when the vehicle is seen from the plane;
[0053] [0053]FIG. 6A is a view showing one example of a preferable detection range of a sensor provided to correspond to the sensor shown in FIG. 5, and a view showing the detection range when the vehicle is seen from the side-surface;
[0054] [0054]FIG. 6B is a view showing one example of a preferable detection range of a sensor provided to correspond to the sensor shown in FIG. 5, and a view showing the detection range when the vehicle is seen from the plane,
[0055] [0055]FIG. 7 is a view showing one example of a detection range when the conical beam sensors are provided around the vehicle;
[0056] [0056]FIG. 8 is a schematic view showing one example of a beam scan sensor;
[0057] [0057]FIG. 9 is an operation conceptual view of the OHT system used in the semiconductor wafer manufacturing process or the like;
[0058] [0058]FIG. 10 is an explanatory view showing a front detection sensor of the OHT vehicle and one example of an obstruction;
[0059] [0059]FIG. 11 is a conceptual view showing an OHT vehicle used in a semiconductor manufacturing apparatus;
[0060] [0060]FIG. 12 is a conceptual view showing a state in which the vehicle uses two front detection sensors to detect a long distance range and a middle distance range; and
[0061] [0061]FIG. 13 is a conceptual view showing one example of an operation state of a plurality of vehicles in the general OHT system.
DETAILED DESCRIPTION OF THE INVENTION
[0062] The following will specifically describe the preferred embodiment of the automatic transport system, according to the present invention with reference to the drawings. Additionally, in the following description, the rail for running is omitted, and an OHT vehicle with a rectangular cross-sectional shape of its front surface, which is considered to be the-passage-area, is explained as an example.
[0063] [0063]FIG. 1 is an outline perspective view of an OHT vehicle according to an embodiment of the present invention. In the FIG. 1, at the front surface portion 2 of an OHT vehicle 1 in the moving direction, four optical sensors S 1 , S 2 , S 3 , and S 4 are arranged along the respective sides of the front surface portion 2 in the moving direction as front detection sensors.
[0064] In order to reserve a minimum area through which the OHT vehicle 1 passes, the optical sensor S 1 , which emits a fan-shaped beam of light, is placed along the side L 1 . Similarly, the optical sensors S 2 , S 3 , and S 4 are arranged along the sides L 2 , L 3 , and L 4 , respectively.
[0065] Each of the optical sensors S 1 , S 2 , S 3 , and S 4 is constituted to have a thin and rectangular slit, for example, along the portion close to each of the sides L 1 , L 2 , L 3 , and L 4 , and an infrared light source is provided in each slit, a light beam from the infrared light source (not shown) is emitted from each slit. Therefore, the respective optical beams are emitted from the respective optical sensors S 1 , S 2 , S 3 , and S 4 in the shapes of fans, and the irradiated light has a cross-sectional shape that is similar to the shape of each slit on a projection surface at a predetermined position.
[0066] [0066]FIG. 2 is a conceptual view showing a state in which the front in the moving direction is detected using the OHT vehicle of FIG. 1. The same figure shows a state in which an imaginary OHT vehicle 1 ′ having the same shape as the OHT vehicle 1 is located ahead in the moving direction of the OHT vehicle 1 .
[0067] On the front surface portion 2 of the OHT vehicle 1 in the moving direction, the optical sensors S 1 , S 2 , S 3 , and S 4 are arranged along the sides L 1 , L 2 , L 3 , and L 4 . Then, an irradiation area ml is irradiated with the light beam emitted from the optical sensor S 1 along a side L 1 ′ of the Imaginary OHT vehicle 1 ′. Also, an irradiation area m 2 is irradiated with the light beam emitted from the optical sensor S 2 along a side L 2 ′ of the imaginary OHT vehicle 1 . Moreover, an irradiation area m 3 is irradiated with the light beam emitted from the optical sensor S 3 along a side L 3 ′ of the imaginary OHT vehicle 1 ′ Then, an irradiation area m 4 is irradiated with the light beam emitted from the optical sensor S 4 along a side L 4 ′ of the imaginary OHT vehicle 1 ′.
[0068] Moreover, lights from the optical beams reflected by these irradiation areas m 1 , m 2 , m 3 and m 4 are detected by the optical sensors S 1 , S 2 , S 3 , and S 4 , respectively. A detection area which an obstruction is detected is the strip irradiation areas m 1 , m 2 , m 3 and m 4 of the beam light expanded in the shape of fan from the respective optical sensors S 1 , S 2 , S 3 , and S 4 .
[0069] This makes it possible to detect obstructions in the area which is surrounded by the sides L 1 ′, L 2 ′, L 3 ′ and L 4 ′ of the imaginary OHT vehicle 1 ′ and in the passage area which is surrounded with the sides L 1 , L 2 , L 3 , and L 4 of the front surface portion 2 of the OHT vehicle 1 in the moving direction. Therefore detection can be carried out without failures. In addition, the detection area is the area of the front surface portion 2 of the OHT vehicle 1 in the moving direction and the detection of obstructions in the OHT system can be carried out extremely efficiently without the occurrence of a detection leakage or an excessive detection.
[0070] Additionally, in performing the actual detection of obstructions, the setting of the direction of irradiation of the optical beams emitted by the respective optical sensors S 1 , S 2 , S 3 and S 4 is contrived to as to irradiate areas which are a little wider than that passage area of the OHT vehicle 1 . However, it is desirable to avoid detection of the peripheral manufacturing apparatuses. Also, it is desirable to prevent unnecessary detections and due to mechanical shift caused by vibration lichen the OHT vehicle 1 moves.
[0071] Regarding the specific method for setting the optical beams, for example, the respective optical sensors S 1 , S 2 , S 3 , and S 4 can be provided with an optical guide cylinder for restricting the direction in which light is emitted. Then, the directions of the optical beams emitted from the respective optical guide cylinder are controlled to be directed slightly to the outside of the outer periphery of the imaginary OHT vehicle 1 ′. If the irradiation areas m 1 , m 2 , m 3 , and m 4 of FIG. 2 are extended to slightly outside of the sides L 1 ′, L 2 ′, L 3 ′ and L 4 ′ of the imaginary OHT vehicle 1 ′, an areas which is a little wider than the passage area of the OHT vehicle 1 can be detected.
[0072] In this way, if the optical sensors for emitting the fan-shaped optical beams are arranged around the front surface of the OHT vehicle 1 in the moving direction and detect only the passage area of the OHT vehicle 1 efficiently, unnecessary stops of the OHT vehicle 1 and unexpected collisions with parts or the like can be prevented, and the OHT vehicle 1 can be efficiently operated.
[0073] The above embodiment describes an OHT vehicle 1 whose cross-section in the moving direction is rectangular. However, the cross-sectional shape in the moving direction is not limited to a rectangle, and the present invention can be applied to any cross-sectional shape. For example, if the cross-section of the OHT vehicle in the moving direction is polygonal, the irradiation of strips of light may be provided such that the respective sides are connected to one another to made a polygonal shape. Moreover, if the cross-section of the OHT vehicle in the moving direction is an elliptical shape, irradiation of the strips of light may be provided at the entire the outer periphery of the elliptical shape.
[0074] Next, a description is given of the actual-use of an OHT vehicle having the aforementioned front detection sensor. FIG. 3 is a perspective view showing one example of a semiconductor manufacturing apparatus using the OHT vehicle of the present invention.
[0075] In the case of manufacturing a semiconductor device by the semiconductor manufacturing device illustrated in FIG. 3, the aforementioned OHT vehicle is used to automatically transport semiconductor craters among various kinds of apparatuses. Generally, semiconductor wafers such as silicon wafers are transported by moving the OHT vehicle back and forth among various kinds of semiconductor manufacturing apparatuses (for example, a wafer processing apparatus, a storage apparatus, a workbench, a buffer apparatus, and so on), whereby the semiconductor devices are manufactured via numerous processes.
[0076] The process in which the OHT vehicle transports the semiconductor wafers is explained with reference to FIG. 3. An OHT vehicle 12 , which hangs on a rail 11 mounted on a ceiling of a clean room (not shown), runs freely, and a wafer carrier 14 on which semiconductor wafers 13 are leaded is transferred between the respective semiconductor manufacturing apparatuses 15 or between a semiconductor manufacturing apparatus 15 and a stocker 16 , and various kinds of processes are carried out on the wafers.
[0077] The OHT vehicle 12 shown in this figure comprises a ruining section 12 a that runs along the rail 11 , a hanging section 12 b that is provided at a lower portion of the running section 12 a , and a hand 12 c that hangs from the hanging section 12 b to be movable up and down. Specifically, the wafer carrier 14 that is placed on a load port 15 a of the semiconductor manufacturing apparatus 15 is held by the hand 12 c . Then, the hanging section 12 b moves up the hand 12 c , thereafter the OHR vehicle 12 runs along the rail 11 by the running section 12 a.
[0078] In manufacturing the semiconductor device, a plurality of OHT vehicles 12 move back and forth between the plurality of semiconductor manufacturing apparatuses 15 arranged in parallel along the rail 11 , and hold the wafer carrier 14 from the load port 15 a of each semiconductor manufacturing apparatus 15 to be transferred to the load port 15 a of another semiconductor manufacturing apparatus 15 .
[0079] In transporting the wafer carrier 14 , the OHT vehicle 12 first runs along the rail 11 and is stopped at the portion above the load port 15 a having the wafer carrier 14 to be transported thereon. Then, the hand hanging section 12 b is lowered to move the hand 12 c down, and this hand 12 c holds the wafer carrier 14 . Then, the hand hanging section 12 b is hoisted up to remove the wafer carrier 14 from the load port 15 a and to be the highest position. Thereafter, the OHT vehicle 12 is run again.
[0080] Then, the OHT vehicle 12 is stopped at another semiconductor manufacturing apparatus 15 , which performs the next process, or the load port 15 a of the stocker 16 . Then, the hand hanging section 12 b is lowered to lower the hand 12 c so that the wafer carrier 14 is mounted on the load port 15 a . Thereafter, the hand 12 c releases the wafer carrier 14 . Then, the hand hanging section 12 b is hoisted up to raise the hand 12 c , and the operation proceeds to the a next transporting operation.
[0081] Incidentally, the aforementioned transport system has a vehicle providing the front detection sensor (not shown) which detects an obstruction in the minimum range with no obstruction to movement of the OHT vehicle 12 . Therefore in the transport system can prevent the OHT vehicle 12 from contacting the doors of various kinds of apparatuses placed in the moving direction of the OHT vehicle 12 , adjacent parts or the like, and from being stopped after detecting doors and parts even though they are not obstructing the movement of the OHT vehicle 12 , since the transport work carry out in a small area. The detecting by the front detection sensor (not shown) allows the OHT system of the semiconductor manufacturing apparatus to perform efficient processing of the semiconductor wafer. This makes it possible to further improve the production efficiency of semiconductor devices or the like.
[0082] The aforementioned embodiment is one example to describe the present invention. However, the present invention is not limited to the above embodiment, and various modifications may be possible within the gist, of the invention. Namely, the aforementioned embodiment described the case in which the front detection sensor is provided on an OHT vehicle that runs along a ceiling rail. However, the present invention is not limited to this. For example, it is possible to provide the front detection sensor on an AGV that runs on the floor or an RGV that runs on a rail. The AGV and the RGV are used in process lines in which materials are transported and finished products are moved without human intervention in an automated factory. The provision of the front detection sensor of the present invention prevents the AGV and the RGV from being stopped unnecessarily and from colliding with the other parts and breaking them.
[0083] Next, an explanation is given of the operation system of the present invention in the case that a plurality of vehicles, each having the aforementioned optical sensors, run on the rail. FIG. 4 is a conceptual view showing a state in which a long range detection sensor and a short range detection sensor detect an obstruction in the OHT system of the present invention. In addition, the long range detection sensor device a sensor which has the longer detection range than that of the short range detection sensor.
[0084] In FIG. 4, in the OHT system of the present invention, a-front vehicle 4 and a trailing vehicle 5 hang on a rail 3 and run in the advancing direction indicated by the arrow in the figure. Moreover, a stepladder 6 with a height which does not obstruct the movement of vehicles 4 and 5 , is placed in pass of the respective vehicles 4 and 5 . Moreover, each of the vehicles 4 and 5 has the optical sensors at its front surface as shown in FIGS. 1 and 2, although these sensors are not illustrated in FIG. 4. Further, the trailing vehicle 5 has a vehicle determination sensor (light receiving device) 7 a as an obstruction determining device, which determines whether the obstruction ahead is a vehicle or not, on its front surface. The front vehicle 4 has a vehicle determination sensor (light emitting device) 7 b on its rear surface.
[0085] Now, a description is given of a case in which the trailing vehicle 5 is running while detecting ahead using the optical sensor (not shown). The optical sensor of the vehicle 5 has a long range detection sensor and a short range detection sensor. The long range detection sensor switches among two range, i.e., of the long range P 1 and the medium range P 2 , making it possible to detect an obstruction. For example, the long range P 1 can be used to detect obstructions at a distance of 2 to 3 m, and the medium range P 2 can be used to detect obstructions at a distance of 0.5 to 1.5 m. Moreover, a short range detection sensor can detect obstructions in a short range P 3 , which is shorter than the middle range P 2 (that is, 0.5 to 1.5 m).
[0086] Firstly, when the trailing vehicle 5 advances, the long range detection sensor, which is provided on the vehicle 5 , detects the obstruction (that is, front vehicle 4 ) with in the long range PI. As a result, if the vehicle 5 continues to advance while reducing its speed, the long range detection sensor detects the obstruction (that is, vehicle 4 ) within the middle range P 2 . Thereafter, when the vehicle determination sensor (light receiving device) 7 a , which the vehicle 5 has, receives an optical signal from the vehicle determination sensor (light emitter) 7 b of the vehicle 4 , which is the obstruction ahead, and thereby confirms that the obstruction ahead is the vehicle 4 , and the rear vehicle 5 further reduces its speed. Then, the vehicle 5 advances until the short range detection sensor of the vehicle 5 detects the vehicle 4 within the short range P 3 . Thereafter, at the point when the short range detection sensor of the vehicle 5 detects the vehicle 4 at the short range P 3 , the vehicle 5 stops. For example, the short range P 3 is set to about 0.2 to 0.1 m such that the back vehicle 5 is stopped at the shortest range at which the vehicle 5 does not collide with the front vehicle 4 .
[0087] If there is a station (transfer port of assembly apparatus) which has made a transfer request to the vehicle 5 which is located at a position which is before the vehicle reaches within the short range P 3 , the vehicle 5 can be stopped at the position of the station. When the vehicle 5 reaches the station which has made the transfer request to the vehicle 0.5 while the long range detection sensor is detecting in long range P 1 or the medium range P 2 and braking is performed, it is possible to stop the vehicle 5 at the corresponding station before the short range detection sensor detects in the short range P 3 .
[0088] Moreover, if the vehicle determination sensor (light receiving device) 7 a provided on vehicle 5 , cannot confirm that an obstruction ahead is a vehicle 4 when the long range detection sensor provided on the vehicle 5 detects the obstruction within the long range P 1 or the middle distance P 2 while the trailing vehicle 5 is advancing. When no optical signal is received from the vehicle determination sensor (light emitting device) 7 b of the front vehicle 4 , it is determined that the obstruction ahead is not a vehicle.
[0089] In this case, since the detected obstruction is, for example, the stepladder 6 , the vehicle 5 can be immediately stopped or the vehicle 5 can be stopped after advancing the vehicle 5 close to the stepladder 6 according to the presetting of the OHT system. The above embodiment describes the case in which the long range detection sensor is operated in the two steps of the long distance P 1 and middle distance P 2 . However, the long range detection sensor may be operated to detect a predetermined distance in only one step. Moreover, the number of long range detection sensors provided at the front surface of the vehicle is not limited to one. Namely, a plurality of sensors may be provided as the optical sensors shown in the aforementioned FIG. 1.
[0090] Herein, specific embodiments of the vehicle determination sensor, which is an obstruction determining device, will be described in more detail. Regarding the first embodiment, as illustrated in FIG. 4, a vehicle determination sensor (light receiving device) 7 a is provided at the front portion of each vehicle and a vehicle determination sensor (light emitting device) 7 b is provided at the rear portion. When the vehicle determination sensor (light receiving device) 7 a of the front portion of the trailing vehicle 5 receives an optical signal from the vehicle determination sensor (light emitting device) 7 b of the rear portion of the front vehicle 4 , it is determined that the obstruction ahead is a vehicle.
[0091] Moreover, in the second embodiment of the vehicle determination sensor, a reflector is provided at the rear portion of the front vehicle 4 , and a reflection sensor, which receives an optical signal from the reflector, is provided at the front portion of the trailing vehicle 5 . When the reflection sensor of the trailing vehicle 5 receives the optical signal, it is determined that the obstruction ahead is a vehicle. When the reflecting sensor of the trailing vehicle 5 receives no optical signal, it is determined that the obstruction ahead is not a vehicle.
[0092] Furthermore, regarding the third embodiment of the vehicle determination sensor, as described in the aforementioned FIG. 1, the plurality of sensors are arranged along the outer periphery of the vehicle and the plurality of sensors operate on the principle of an AND operation making it possible to more reliably recognize that the obstruction ahead is the vehicle. In other words, as mentioned in FIG. 1 and FIG. 2. concerning the optical sensors, that is, obstruction detection sensors, four optical sensors S 1 , S 2 , S 3 , and S 4 are provided along the respective sides of the front surface portions in the moving direction of each vehicle. Then, the sensors are designed to detect the outer peripheral area of a vehicle running ahead. Therefore, when an area different from this area is detected, it is determined that the obstruction ahead is not the vehicle.
[0093] In other words, based on the AND condition applied to the four optical sensors S 1 , S 2 , SB, and S 4 , only when the signals are sent by all optical sensors S 1 , S 2 , S 3 , and S 4 , it is determined that the obstruction ahead is a vehicle. Then, when no signal is sent by any one of the optical sensors, it is determined that the obstruction ahead is not the vehicle. Furthermore, the detection of a logical sum using a plurality of sensors in this way leads to the effect that the trailing vehicle is effectively moved forward. In addition, even if the plurality of vehicle determination sensors 7 a and 7 b of FIG. 4 and logic such as an OR condition are used, there is the effect that the trailing vehicle is effectively moved forward.
[0094] Note that, as specific embodiments of the above-described long range detection sensor and the short range detection sensor, there are conical beam sensors, which output long conical beams, beam scanning sensors, which scans beams, and the like.
[0095] [0095]FIG. 5 is a view showing one example of using conical beam sensors as sensors S 1 and S 2 of FIG. 1 to detect the upper end and lower end. FIG. 5A is a view showing the detection range when the vehicle is seen from the side surface, and FIG. 5B is a view showing the detection range when the vehicle is shown upper side.
[0096] Thus, when the conical beam sensors are used as sensors S 1 and S 2 , the detecting range has a conical shape expanding widely in a width direction and thinly in a height direction.
[0097] Moreover, FIG. 7 shows one example of a detection range. In this figure, the conical beam sensors shown in FIG. 5 are arranged near the outer periphery of the vehicle 41 .
[0098] Also, FIG. 6A and FIG. 6B are views, each showing examples of the detection range of the conical beam sensor. As illustrated in these figures, it is preferably that the sensor has a wide detection range in which obstructions near the vehicle are detected.
[0099] [0099]FIG. 8 is a schematic view showing one example of the beam scan sensor. This figure shows a state in which scanning with rays of light emitted from an LED 42 , which is provided at the front surface of an AGV 41 that runs on the floor surface, is performed for tong range and short range detection. For example, a semi-circular field 43 is scanned with rays of light with a wavelength of λ=870 nm emitted from the LED 42 at a step 9 (angle (162°). Then, coordinates are calculated based on a distance measurement and the step angle so as to detect an obstruction. Also, the detection area can be optionally selected, and the setting of the detection area can be carried out by any method such as a volume operation or an operation of a personal computer. For example, the detection area is set by the operation of a personal computer, making it possible to optionally switch the areas from among seven patterns.
[0100] The aforementioned embodiment is one example to describe the present invention. However, the present invention is not limited to the above embodiment, and various modifications may be possible within the gist of the invention. Namely, the aforementioned embodiment describes the case in which the front detection sensor is provided on an OHT vehicle that runs along a ceiling rail. However, the present invention is not limited to this. For example, it is possible to provide the front detection sensor on an AGV that runs on the floor or on an RGV that runs on a rail. AGV and RGV's are used in process lines in which materials are transported and finished products are moved without human intervention in an automated factory. The provision of the front detection sensor of the present invention prevents AGV's and RGV's from being stopped unnecessarily and from colliding with the other parts and breaking them.
[0101] Although the preferred embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions and alternations can be made thereto without departing from spirit and scope of the inventions as defined by the appended claims.
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An object of the present invention is to improve the transportation efficiency of an automatic transport system for transporting an article. In order to attain the above object, the automatic transport system of the present invention comprises a front detecting device which detects an obstruction in a non-contact state in an area through which an automatic transport vehicle passes and a projection surface of said automatic transport vehicle, and when said front detecting device detects the obstruction in said area, the running speed of said automatic transport vehicle is reduced or said automatic transport vehicle is stopped.
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BACKGROUND OF THE INVENTION
Conventional curtains to be attached to a window side of a room are used solely for the specific purposes of providing an ornament for a room and obtaining an internal space of a room or securing privacy.
In ordinary practice, two curtain rails are employed and a single sheet of curtain made of a relatively thick woven fabric or the like is hung on the room side or the window side and another single sheet of curtain made of a relatively thin material such as a lace material is hung on the window side or the room side, so that they can be opened and closed in accordance with necessity. In a day time, the relatively thick curtain made of a woven fabric material or the like is pulled opposite sides of the window in order to permit sun light to enter the room and only the relatively thick curtain made of a lace material or the like is closed. At night, however, only the relatively thin curtain made of a lace material or the like is not good enough because the inside of the room can be seen from outside through the lace curtain under the effect of light of the room lamp. Therefore, it is necessary to close the relatively thick curtain made of a woven fabric material so that the inside of the room cannot be see from outside.
The curtain used in the manner as mentioned above is called "dual curtain". As mentioned above, it is necessary for such a dual curtain to employ two curtain rails and two sheets of different kind of relatively thick and thin curtain materials.
In case of a window provided with only one curtain rail by some reasons (for example, a limited space just enough for mounting only one curtain rail, an economical reason or the like), only one of the curtain sheets, either the relatively thick one or the thin one, is employed. In this case, it is impossible, unlike in the case of the dual curtain, to selectively use the relatively thick or thin curtain in accordance with necessity.
There is also another example of a conventional curtain formed by integrally attaching two layers of fabric materials together. In this example, a sheet of front curtain material (the fabric appeared to the room side) is attached with a sheet of back curtain material (the fabric appeared to the window side) so that light shieldability is enhanced. There is still another example of a conventional curtain formed by integrally attaching two layers of fabric materials together. In this example, two sheets of relatively thin curtain material each having a good light permeability are attached together so that the final curtain allows light to permeate therethrough but does not allow the inside of the room to be seen from outside.
In the above additional examples, both the front and back curtain material sheets are attached by stitching with lug portions on opposite sides and occasionally with skirt portions and the two sheets of front and back curtain material are usually used as one piece. However, since there are differences in kind of the starting yarn used in the two sheets of fabric material (front sheet and back sheet), weaving texture, amounts of finishing agents such as various kinds of resins at the time of processing, heat effect at the time of heat set, etc., the two sheets of fabric material are not always entirely equal in elasticity.
Accordingly, if those two sheets of fabric material are stitched at their lug portions at opposite sides thereof into an integral curtain, a contracting wrinkle and an expanding wrinkle tend to occur in use due to difference in elasticity between the front fabric material and the back fabric material, thus resulting in a poor appearance.
SUMMARY OF THE INVENTION
This invention relates to a multilayered integral type curtain applicable to a window or the like.
The first object of the present invention is to obtain a triple layered integral type curtain capable of satisfying the requirements of utility and ornament by fixing three sheets of different kind of curtain material only at their upper edges by means of stitching or the like, so that three different kinds of curtain can be used with a single curtain rail or a single curtain rod, whereby, a single or plural sheets of curtain having best suited material can be used depending on circumstance, or the integral type curtain as a whole can be opened in accordance with necessity.
The second object of the present invention is to obtain a double layered integral type curtain by fixing two sheets of front and back fabric material only at their upper portions with opposite side edges and skirt portions thereof being open, so that an occurrence of wrinkle can be prevented in use.
The above objects can be achieved by the construction of the above-mentioned multilayered integral type curtain according to the present invention. Specific embodiments of the present invention are exemplified in the accompanying drawings and in the detailed description of the invention to be described hereinafter. Any minor alternation and modification are included in the scope of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view for explaining one embodiment of a triple layered integral type curtain according to the present invention;
FIG. 2 is a view for explaining a state of use of the embodiment of FIG. 1; and
FIG. 3 is an explanatory view of a double layered curtain according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As one embodiment of the present invention, FIG. 1 shows a triple layered integral type curtain including a left half portion (X) and a right half portion (X'). Those left and right half portions (X), (X') of the curtain each comprises a first layer of curtain (A), (A') made of a comparatively thick woven fabric material or the like, a second layer curtain (B), (B') made of a comparatively thin woven fabric material or the like and a third layer (C), (C') of a comparatively thin fabric material such as lace or the like. The first to third layers of curtain are fixed by stitching only at upper edges thereof to form an integral curtain assembly. There are provided a plurality of tucks (T) along a stitch line (e). Each tuck (T) is provided on a back side thereof with a hook not shown, so that the curtain can be hung on a single curtain rail or a single curtain rod.
FIG. 2 shows a state of use of the triple layered curtain (X), (X') of FIG. 1. That is, in a day time, the first layer of curtain (A), (A') made of a comparatively thick woven fabric material or the like is pulled to opposite sides (W), (W') of the window and retained by tassel bands (R), (R). At that time, the second layer curtain (B), (B') made of a comparatively thin woven fabric material or the like and the third layer (C), (C') of a comparatively thin fabric material such as lace or the like are in a closed position. In this state, a sufficient amount of light is allowed to enter the inside of the room from outside.
However, since the second layer curtain (B), (B') made of a comparatively thin woven fabric material or the like is closed in the above-mentioned state, the inside of the room cannot be seen from outside although a sufficient amount of light is allowed to enter the inside of the room from outside as previously mentioned. That is, although a reflecting light is allowed to enter the inside of the room in the above-mentioned state, a direct light proceeding straight ahead is restricted from passage through the curtain. This means that the ultraviolet ray and the infrared ray are also restricted from passage through the second layer curtain (B), (B') made of a comparatively thin woven fabric material or the like. In order to more efficiently achieve this purpose, the second layer curtain (B), (B') made of a comparatively thin woven fabric material or the like may be preliminarily fixedly impregnated with an ultraviolet ray absorbent agent and/or an infrared ray absorbent agent.
When sun light needs to be brought into the inside of the room from outside in a day time, second layer curtain (B), (B') made of a comparatively thin woven fabric material or the like is also pulled to the opposite sides (W), (W') of the window. That is, second layer curtain (B), (B') made of a comparatively thin woven fabric material or the like are also retained by tassel bands (R), (R') together with the first layer of curtain (A), (A') made of a comparatively thick woven fabric material or the like. In this way, there can be provided a multi-purpose triple layered integral type curtain (X), (X'), in which only the third layer (C), (C') of a comparatively thin fabric material such as lace or the like can be used, and when the first layer of curtain (A), (A') made of a comparatively thick woven fabric material or the like is closed, the outside cannot be seen from inside by the first layer of curtain (A), (A') and light can be restricted from passage through the curtain, with a single curtain rail or a single curtain rod. Moreover, since the triple layered integral type curtain (X), (X') are divided into two half portions at its central portion, the entire triple layered integral type curtain (X), (X') can be fully opened simply by pulling the two half portions to the opposite sides of the window.
With the triple layered integral type curtain (X), (X') according to the present invention, the first layer of curtain (A), (A') is gathered sideways and retained in a day time so that light can be freely brought into the inside of the room, and the first layer of curtain (A), (A') is spread by releasing the tassel bands at night so that the inside of the room cannot be seen from outside, and in addition, light can be restricted from passage through the curtain, by selectively using one or two or whole of the first to third layers of curtain. By this, there can be provided a curtain directly coping with a new interior design satisfying the requirements of ornament, performance and utility in addition to its feature of depth.
As the second embodiment of the present invention, there is provided a curtain (X") of FIG. 3 comprising a first and a second sheet of curtain material (x 1 ), (x 2 ) which are integrally fixed at an upper edge (1) of the curtain and provided with a plurality of tucks (T) at an upper edge area of the curtain. Lug portions (a 1 ), (a 2 ) at the opposite side edges and skirt portions (b 1 ), (b 2 ) are defined as a triple stitching portion (c) and are open. With such construction of a curtain, a back curtain fabric is attached to a front curtain fabric to form a double layered integral type curtain. In this way, the curtain as a double layered integral type is capable of enhancing shieldability of light. In addition, it can be used in such a manner as to allow passage of light but to make it difficult to see the inside of the room from outside by using the two layers of comparatively thin curtain fabric material each of which allows a good passage of light. In other words, this curtain exhibits a good light shielding and blocking performance. Moreover, an occurrence of wrinkle due to difference in expansion and contraction between the two sheets of curtain fabric material can be prevented.
This means that the present invention is applicable not only to the ordinary dual curtain using comparatively two sheets of thick and thin curtain fabric material but also to a double layered integral type curtain using a front fabric material and a back fabric material having vertically and horizontally different expansion and contraction which are conventionally supposed to be difficult to use for forming a dual curtain without any occurrence of wrinkle.
Moreover, by further provided with a wavy configuration (n) by holding the curtain (X") with a wavy form in a sandwiching manner and heat setting the same, there can be provided a first and a second sheet of curtain material (x 1 ), (x 2 ) in which valley portions and bump portions of the wavy configuration are in contact with each other, respectively, while allowing the area excluding the upper edge (1) to be free. Thus, this curtain can exhibit a stable configuration and performance as a double layered curtain.
In this way, there can be obtained a double layered curtain suitable as a room interior design.
It should be noted that the wavy configuration (n) can likewise be provided to the triple layered integral type curtain (X), (X') according to the first embodiment of the present invention in the same manner as in the curtain (X") according to the second embodiment.
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A multilayered integral curtain comprising a first layer of curtain made of a comparatively thick woven fabric material or the like, a second layer curtain made of a comparatively thin woven fabric material, and a third layer of a comparatively thin fabric material such as lace, said first to third payers of curtain being integrally fixed only at upper edges thereof and hung down from a single supporting member.
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BACKGROUND INFORMATION
[0001] Driver information systems are known in the form of vehicle navigation systems which output driving-direction information in acoustic and/or optical form to guide the driver of a vehicle along a previously calculated route to a destination. In order for the route to be calculated, the driver must first input the destination via an operator interface of the vehicle navigation system. Since inputting a destination while driving substantially distracts a driver from the traffic situation, it has been and is currently being discussed to prevent operation of the device, in particular to prevent the destination from being input during vehicle travel (so-called speed-lock function).
[0002] Many of today's vehicles make use of a signal that indicates passenger seat occupancy, which is used, for example, for an airbag control.
SUMMARY OF THE INVENTION
[0003] A driver information system according to the present invention advantageously makes use of a signal that is available in many vehicles and indicates the occupancy of a passenger seat, in order to influence a speed-lock function of the driver information system and, thus, also during vehicle travel, to render possible an operation of the driver information system to a full extent or to an extent that is at least expanded as compared to the speed-lock function. At the same time, the advantages of the speed-lock function, namely that the driver is distracted to a lesser degree by the operation of the vehicle information system, are retained, so that the result is better concentration on the actual driving task and, ultimately, improved traffic safety (safety while driving). In connection with the present invention, operation is understood to be the user's inputs into the driver information system and/or outputs of the driver information system to the user.
[0004] Thus, in the case of a navigation system, the front-seat passenger can take over operation of the navigation system during travel. For example, the need may arise during vehicle travel to manually change the driving route because of traffic disturbances not considered in a preceding route calculation or because of errors in the navigation data material.
[0005] In this way, during vehicle trips where there is a passenger, additional inputs may be made and unnecessary stops avoided. Safety arguments are likewise overcome. Also, within the framework of the speed-lock function, the present invention also permits a more advanced restriction of the operational control, where necessary, during operation without a passenger.
[0006] In any case, the present invention increases user acceptance of the speed-lock function and ensures a competitive advantage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] [0007]FIG. 1 shows a block diagram of the part of a driver information system according to the present invention that is important to the present invention.
[0008] [0008]FIG. 2 is a flow chart of the part of a control software that runs in a control of the driver information system.
DETAILED DESCRIPTION
[0009] Referring to FIG. 1, the driver information system according to the present invention is elucidated in the following using primarily the example of a vehicle navigation system. However, this does not signify any restriction of the present invention to vehicle navigation systems. Rather, the present invention is also applicable to other driver information systems, such as car radios, or mobile cellular phones operated in a vehicle.
[0010] Driver information system 1 according to the present invention includes an input device 13 having operating elements, preferably tip switches and/or incremental encoders, for inputting commands and/or operating parameters into driver information system 1 . In the case of a vehicle navigation system, the described operating elements are used, for example, in conjunction with a control 12 of the navigation system, for inputting a destination for a subsequent route calculation from the current location to the destination, and a subsequent route guidance. In the case of a mobile cellular phone, the operating elements are used, for example, for dialing a specific phone number of a desired telephone conversation partner or for receiving an incoming phone call.
[0011] Driver information system 1 according to the present invention also includes an output device 14 , preferably designed as an optical and/or acoustic output. In the case of a vehicle navigation system, output device 14 , in conjunction with the route guidance, is used for outputting driving-direction information for directing the vehicle driver in the form of spoken driving-direction information and/or in the form of directional arrows indicated on a display. Alternatively or in addition, a map display may be provided on which the calculated route or a detail of the same may be displayed to orient the vehicle driver.
[0012] In addition, output device 14 is used in conjunction with the destination input, for example, to display selectable destinations and/or a map display, on which a destination may be marked by using a cursor that is controllable by the operating elements of input device 13 .
[0013] In the case of a car radio, output device 14 includes, for example, the display of the car radio on which, besides the name or the incoming frequency of an actively set transmitter, changing displays, such as the title and intrepreter of an actively transmitted piece of music or tickers, such as advertising texts, transmitted by the radio data system (RDS) are displayed.
[0014] Input device 13 and output device 14 , which are each linked to control 12 , together form an operator control 15 of the driver information system according to the present invention.
[0015] In addition, means 11 for generating at least one signal indicating the state of motion, in particular the travel, in contrast to standstill of the motor vehicle, are linked to control 12 of the driver information system according to the present invention. It is a question in this context, for example, of a speedometer-signal generator which indicates the current vehicle speed. In the case of a vehicle navigation system 1 , means 11 may also include a GPS receiver, which evaluates positional data pertaining to the active vehicle position and derives therefrom a signal indicating the active state of motion of the vehicle.
[0016] The signals indicating the state of motion of the vehicle, e.g., of speedometer-signal generator 112 , are fed to an evaluation 111 , which is preferably designed as a component of the control in the form of a software routine. Evaluation 111 is designed, on the basis of the signals indicating the state of motion of the vehicle, to make a decision as to whether the vehicle is at a standstill, is driving, or is driving at a specific minimum speed.
[0017] Together, signal generator 112 and evaluation 111 form a device 11 for detecting driving of the motor vehicle.
[0018] A sensor 101 , which generates a signal indicating occupancy of the passenger seat, is also connected to control 12 . This sensor 101 may be designed, for example, in the form of a weight sensor, which senses a loading of the passenger seat by the weight of a passenger.
[0019] Alternatively or additionally, a signal indicating occupancy of the passenger seat may also be generated by a belt-latch mechanism 102 for the seat belt, the passenger seat being indicated as occupied when belt-latch mechanism 102 is closed, the seat belt therefore being engaged.
[0020] The signals of sensor 101 , of belt-latch mechanism 102 or of both sensors are analyzed in a further evaluation 103 , which is preferably designed, in turn, as a component of control 12 , to detect occupancy of the passenger seat. Thus, seat-occupancy sensor 101 and/or belt-latch mechanism 102 of the passenger seat, and further evaluation 103 form a device 10 for detecting occupancy of a passenger seat of the vehicle.
[0021] One advantageous embodiment of the present invention takes into consideration that today's child safety seats are often designed to be installed on the front passenger seat next to the driver's seat, to enable small children to be safely transported in motor vehicles, such child safety seats often being secured by seat belts. In the case that such a child safety seat is installed, further evaluation 103 in accordance with the above exemplary embodiment would detect the occupancy of the passenger seat, the small child being transported there, however, not being able to take over operation of the driver information system. For that reason, this advantageous embodiment provides that a deactivation of the airbag, as provided in today's vehicles in connection with the described child safety seats, is considered in the context of the passenger-seat occupancy detection in such a way that the passenger seat may only be detected as being occupied when the airbag is not deactivated.
[0022] Another advantageous refinement of the above described embodiments is suited for vehicles equipped with additional operator controls intended for use behind the driver's seat or other passenger seats (rear seat bench, or the like) which are arranged elsewhere in the vehicle. At the present time, such installations are known above all from luxury class vehicles, in which, for example, displays are configured as additional output devices in the headrests of the front seats and are used to entertain the rear passengers. Additional input devices are routinely assigned to the displays, for example, for selecting a television program or for operating a computer game. In accordance with the present invention, these additional operator controls, thus displays and input devices, may be used for operating the driver information system. For this purpose, this embodiment also provides for detecting the occupancy of a passenger seat in the rear of the vehicle. In the event that presence of a passenger is detected both at a rear seat, as well as at the front seat, it may be provided for the front seat passenger to be assigned a higher priority for the operation of the driver information system. In the same way, however, it may also be provided for the priority to be freely adjustable.
[0023] Control 12 of the driver information system includes a third module 121 , which is preferably designed, in turn, in the form of a software routine for controlling the scope of the operation or operability of the driver information system via operator control 15 . For this purpose, control 12 is designed to at least partially limit an operation of the driver information system using operator control 15 , thus user inputs via input device 13 and/or outputs of the driver information system to the user via output device 14 , as a function of device 11 for detecting travel of the motor vehicle. Thus, control 12 implements a speed-lock function in the above sense.
[0024] The speed-lock function prevents all user inputs when driving the vehicle, by way of input device 13 of the driver information system. In addition, it may be provided for displays or acoustic outputs, which require a high level of concentration on the part of the vehicle driver in order to be properly picked up, and, thus, considerably distract the vehicle driver, to be eliminated or replaced by outputs that are easier to pick up. In a vehicle navigation system, for example, within the framework of route guidance during vehicle travel, a map display having a marked route is replaced by a simpler and more rapidly understood display of turn-off arrows and by a simple acoustic announcement of the turn-off instructions. In the same way, complex announcements, such as “in 500 m, please turn to the left into the Hildesheimer Street. Please reduce your speed, the curve is narrow” may be replaced by briefer instructions prompting action, such as “immediate left” or “next street left”.
[0025] Control 12 or third software module 121 of control 12 of the driver information system is further designed in accordance with the present invention in such a way that the control limitations that accompany the speed-lock function, thus inputs into and/or outputs of the driver information system, are at least partially canceled or suitably adapted in the case of a passenger seat recognized as occupied by occupancy-detection device 10 .
[0026] This is explained in more detail based on the example of the flow chart of FIG. 2.
[0027] In step 21 , control 12 checks on the basis of the speed signal, thus preferably the speedometer signal, whether the vehicle is in motion. This is ascertained, for example, on the basis of a vehicle speed of greater than 5 km/h.
[0028] If no motion of the vehicle, thus standstill, is ascertained, then the control fully releases the operation of driver information system 1 via operator control 15 (step 23 ).
[0029] If, on the other hand, a motion of the vehicle, thus travel, is ascertained, in a further step 22 , control 12 checks on the basis of seatbelt signal 102 and/or of weight sensor 101 , whether the passenger seat is occupied.
[0030] If, accordingly, the passenger seat is not occupied, control 12 activates the speed-lock function (step 24 ), i.e., operation of the driver information system is limited. In the present case of a vehicle navigation system 1 , a selection of navigational destinations or of other adjustment parameters from the list that is displayable on display device 14 , is prevented. The same holds for the inputting of a navigational destination. As described above, what remains enabled here is merely the outputting of route guidance instructions or instructions prompting action.
[0031] In the case of the car radio, for example, the display of tickers or changing displays, such as title and intrepreter displays, is prevented.
[0032] In the case of a mobile cellular phone, for example, the inputting of phone numbers via the keypad of the mobile cellular phone is prevented.
[0033] If, on the other hand, during travel of the vehicle, control 12 determines in step 22 that the passenger seat is occupied, control 12 renders possible at least a limited, but also a full operability of driver information system 1 (step 24 ), depending on the specific embodiment of the present invention. In this case, thus given motion of the vehicle and an occupied passenger seat, control 12 preferably enables all display possibilities and input procedures which are also possible when the vehicle is at a standstill, since they are able to be handled by the passenger who does not have to concentrate on driving the vehicle. Preferably, however, the outputs which are predominantly directed directly toward the vehicle driver who is preoccupied with the driving task, are output in a simplified and, thus, easily grasped form.
[0034] Alternatively, provision may also be made here (step 24 ), for example, for the acoustic driving direction instructions of the navigation system to be output in an abbreviated form that is simple to comprehend, while a detailed map display, with the driving route marked, is shown on the display of the vehicle navigation system, so that it may be understood by the passenger, who is then able to give the vehicle driver explanatory or supplemental instructions, if necessary. In addition, this alternative also provides the passenger with improved possibilities for understanding and, as the case may be, correcting the route.
[0035] In addition, it may also be provided for the extent of operability to be adjustable on an individual basis in the case of vehicle travel with an occupied passenger seat.
[0036] For the case that the vehicle driver and passenger each have separate operator controls available to them, thus their own output and/or input devices, as is the case, for instance, when there are separate entertainment systems for the rear passengers or, for instance, for the case that an extra display device is provided in the instrument cluster, in addition to the display of the driver information system configured in the center console, further control strategies may additionally be provided. Thus, in the case of a traveling vehicle and occupied passenger seat, for instance, simple directional arrows for route guidance may be indicated to the vehicle driver via the additional display in the instrument cluster, while a detailed map display with the route marked is made available to the passenger on the display in the center console or in the headrest of the front seat. In addition, an operation may be rendered possible to the passenger in that, for example, he/she may adjust any desired map detail or zoom factor via the input device, while merely the directional arrows are indicated to the driver.
[0037] The present invention may be used in all driver information systems which have a speed-lock function and which support an access to the passenger seat occupancy. When such a signal is not connected (transmission of signal is blocked), the expanded functionality for the passenger preferably does not apply.
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A driver information system for a motor vehicle having an operator control for operating the driver information system, a device for detecting travel of the motor vehicle, and a control for limiting and/or preventing an operation of the driver information system via the operator control in the case that motor vehicle travel is recognized, in which a device for detecting the occupancy of a passenger seat of the vehicle is provided, and the control is designed to at least partially cancel the limitation and/or prevent the operation of the driver information system. A driver information system advantageously makes use of a signal that is available in many vehicles and indicates the occupancy of a passenger seat, in order to influence a speed-lock function of the driver information system and, thus, also during vehicle travel, to render possible an operation of the driver information system to a full extent or to an extent that is at least expanded as compared to the speed-lock function. At the same time, the advantages of the speed-lock function, namely that the driver is distracted to a lesser degree by the operation of the vehicle information system, are retained, so that the result is better concentration on the actual driving task and, ultimately, improved traffic safety.
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BACKGROUND OF THE INVENTION
The present invention relates to a proximity detonator for flying objects, particularly missiles, for combating flying targets with the use of information regarding the speed between detonator and flying target.
It is known that detonators in flying bodies used to combat flying targets generally employ two sensors, a contact switch which is to respond if a direct hit has been made, and a proximity detonator which is to initiate the self-destruct mechanism of the charge if no direct hit is possible. In other words, such proximity detonator must be designed so that it will not self-destruct if a direct hit is possible and that in the other case it determines the moment of self-destruction so that as many fragments as possible will hit the target.
In a known proximity detonator, self-destruction is initiated in dependence on an angular measurement, as soon as the angle between the line of sight between detonator and target and the longitudinal axis of the flying body carrying the charge and the detonator has reached or exceeded a certain value. In order to prevent self-destruction if a direct hit should be possible later, the proximity measuring portion of this known proximity detonator must be nonsensitive in the direction of the longitudinal axis of the flying body. This can be accomplished in principle with the use of a radar process by providing a zero position in the antenna diagram of the proximity measuring portion of the detonator. The drawback of this is that, particularly when this known detonator is intended for small flying bodies, e.g. for missiles, there is no known way of taking such angle measurement with sufficient accuracy. In the likewise known use of the radar process the zero position in the antenna diagram can also be realized only incompletely so that it may happen that the missile self-destructs in spite of a later possible direct hit.
A further known proximity detonator utilizes a distance measurement with the aid of very short radar pulses. The drawback of this is that there is no known possibility of making the moment of self-destruction dependent, in the desired manner, on the speed relationships between the detonator and the target. Here, too, a zero position must be given in the antenna diagram which again can be realized only incompletely, particularly with small flying bodies such as missiles so that self-destruction before a later direct hit is not impossible.
A process is finally known, particularly for radar detonators for missiles, which operates with the use of information regarding the relative speed between the detonator and the target and can get along without a zero position in the antenna diagram. It is also known that in the radar art a frequency shift occurs as a result of the Doppler effect, when one or two objects move, corresponding to the speed of the objects with respect to one another, which Doppler effect can be utilized to obtain the above-mentioned information. At the moment at which the detonator and the target have reached a minimum distance in this case, this frequency shift becomes zero. Precisely this criterion is utilized in the known process to actuate self-destruction of the combat charge. The drawback of this process is that the detonation occurs too late, due to the travel time required, for fragments of the missile to reach the target, particularly if the speed between the detonator and the target approaches the order of magnitude of the speed of the fragments.
Regarding the above-mentioned state of the art, reference is made to "Impulsfreie elektrische Ruckstrahlverfahren" (Pulse-free electrical reflected beam processes) by F. v. Rautenfeld, 1957, Garmisch-Partenkirchen, published by Deutsche Radar-Verlagsgesellschaft m.b.H., particularly pages 92, 142, 148 and 156.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a proximity detonator of the above-described type which permits determination of the moment of detonation even when used in missiles so that as many fragments as possible will hit the target with adaptation to the encounter situation and under consideration of the speed of the fragments but that, on the other hand, detonation is not initiated if a direct hit would be possible later, without the proximity measuring portion of the detonator having to have a zero position in the direction of the longitudinal axis of the missile.
This is accomplished according to the present invention in that detonation is initiated if the speed of approach v a and the amount of the relative speed v r differ by a firing value K z which is determined according to what is the optimum time for detonation; where ##EQU3## and r=the location vector from detonator to target; ##EQU4## =the differential quotient after time t.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are graphs of Doppler frequency vs. time used in explaining the operation of a detonator according to the invention.
FIGS. 3 through 8a show circuits explaining several embodiments of the invention.
FIG. 9 is a graph explaining the geometric relationships between a flying body and its target.
FIG. 10 displays the coordinate system used and the according geometric relations.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The operation and advantages of the detonator according to the invention will be described below for an embodiment of a special self-contained active radar detonator. It is to be understood, however, that the present invention is conceivable also for other uses, for example with utilization of the laser art or with acoustic processes.
A self-contained active radar detonator does not receive any information in addition to that which it obtains itself. However, it does contain its own transmitter which continuously radiates signals at a certain frequency f s .
The energy reflected by the target is received by the transmitter at a frequency f e and the following applies
f.sub.e =f.sub.s (1+2 v/c (3)
where
c=speed of light.
The following also applies ##EQU5##
A comparison between f s and f e provides the Doppler frequency f d ##EQU6##
Since the transmitting frequency f s and the speed of light c are known, the Doppler frequency f d provides an information about the speed v. A comparison between equations (4) and (1) shows that the speed v is equal to the approach speed v a .
For the case where the minimum distance r min between detonator and target is finite, the following generally applies: ##EQU7##
Equation (6) can also be expressed differently: that is, for
|r|>>r.sub.min (7)
the following applies
v.sub.r ˜v.sub.a (8)
If now the detonator has a range for its radial component which is sufficiently large compared to the expected or permitted minimum distance r min , it will initially measure the relative speed via the Doppler frequency. Upon approaching the target, the Doppler frequency decreases and becomes zero once target and missile have reached their mutual minimum distance. A comparison of the continuously measured speed of approach v a with the initially measured relative speed v r (equations 6 to 8) now permits detonation to be initiated if the difference between both has reached the value K z which above and hereinafter has been and will be called the firing value.
It can be demonstrated very easily how the firing value K z must be varied in dependence on the encounter situation if such variation is necessary at all. It generally applies that if an exact hit of the fragments on that point of the target to which the detonator responds is required, the following condition must be met for the firing value: ##EQU8## where v s =the speed of the fragments with respect to the missile;
K g =the characteristic geometric value.
The characteristic geometric value K g contains no speeds. It can be represented, for example, as a function of the angle enclosed between the direction of the fragments and the longitudinal axis of the missile, the lead angle occurring between the missile speed vector and the relative speed vector, as well as the passing flight angle which describes the position of the speed triangle formed of the vectors of the target speed, the missile speed and the relative speed with respect to the vector of the minimum distance. If these angles are known to the detonator, it will be possible to precisely determine the firing value K z .
However, this is not absolutely necessary in order to realize satisfactory operation of the detonator according to the invention. For a self-contained detonator for missiles it can be assumed, for example, that information other than the relative speed v r is not available. However, in such case the lead angles are generally small and equation (9) can be simplified as follows: ##EQU9##
Consideration of the function of equation (10) shows that in the case where ##EQU10## further simplification is possible inasmuch as the firing value K z can be set constant with slight errors. The firing value K z will then advantageously be between 25 and 30% of the fragment speed with the exact value depending on the range being utilized in equation (11). If a larger range than that of equation (11) is to be utilized, equation (10) can of course be simulated very easily, for example by means of a diode network.
It should also be mentioned that the fragment speed is not constant in time but decreases with the time the fragments are in flight. It is easiest to use that fragment speed which occurs as the average fragment speed until the maximum effective radius has been reached; a more precise determination which can be done mathematically under consideration of all occurring distributions will furnish a better approximation.
Finally it must be pointed out that it is of course also possible to provide information for the detonator from external sources. For example, in missile systems employing control by homing devices the relative speed is often known, thus the detonator need not measure it itself. Similar conditions may apply for the angles from the geometric constant.
The present invention generally affords the possibility of effecting a determination of the moment of firing depending on the information at hand, good accuracy being possible also with great variations of the relative speed v r . Special measures to prevent self-destruction of the combat charge before a later prossible direct hit need not be taken for the detonator according to the present invention since with a direct hit the speed of approach v a until contact is equal to the relative speed v r , i.e. the firing condition is not met; this fact will be explained in detail in connection with FIGS. 1 and 2.
FIG. 1 shows the time dependence of the Doppler frequency f d in a radar detonator upon approach to its respective target. At time t 0 a Doppler frequency emerges from the receiver noise which, with a large distance to the target, is approximately constant and then decreases relatively shortly before the point of reverse. The point of reverse is understood to mean, in the usual manner, that point at which the relative radial speed between detonator and target is zero. After reaching the point of reverse the distance between detonator and target increases again, the Doppler frequency increases again in a mirror image to the frequency axis, i.e. to the ordinate of the diagram of FIG. 1 but in the opposite phase.
In FIG. 1, a indicates that part of a curve f d =f(t) which corresponds to the time, during the approach of the detonator to its target, between the appearance of the Doppler frequency, from out of the noise, and the reaching of the point of reverse, at which time curve portion a decreases to the time axis, i.e. the abscissa. That curve portion of the same function which corresponds to the time between reaching the point of reverse and the disappearance of the Doppler frequency in the noise at time t 2 is marked b. The corresponding curve portions of a function associated to a lower relative speed v r between detonator and target than the function of curve portions a and b are marked c and d. At this opportunity it should be pointed out that the frequency drop of the Doppler frequency f d toward zero begins approximately at the same time t 1 for both curve portions a and b but with different slopes. In the same sense the mirror-image curve portions d and b also have different slopes.
FIG. 2 once again shows the function with curve portions a and b in solid lines. For the case, that the detonator will not fly by the target but hit the target, the Doppler frequency f d remains constant over the further time periods equal to that between time intervals t 0 and t 1 . This case is shown in FIG. 2 in dashed lines and marked as function part e whereas at t=0 impact occurs. Additionally there is in FIG. 2 a dot-dash function part f with its mirror-image extension g to show the differences which result compared to the function having curve portions a and b when the detonator flies by the target at a greater distance.
FIG. 3 shows the block diagram of a preferred embodiment of the invention wherein the firing value K z may be constant or variable according to a predetermined law as otherwise specified.
An antenna 2 is coupled with a mixing stage 1. Via antenna 2 electromagnetic waves are transmitted and echo signals from targets received. The mixing stage 1 delivers to an audio frequency amplifier 3 a doppler frequency signal, the frequency of which is the difference between the transmitting and receiving frequencies. The Doppler frequency signal at the output of the amplifier 3 is designated f D . This Doppler frequency signal is passed through a limiting stage 4. A frequency measuring stage 5 known per se determines the actual value of the Doppler frequency f D and delivers at its output a direct current voltage the value of which is dependent upon the Doppler frequency.
At the output of the frequency measuring stage 5 is provided a circuit consisting of three stages 7, 8 and 9. This circuit is shown in FIG. 3 within a dash-dotted block 6 which, in more detail, is shown in FIG. 4.
Block 6 comprises two signal channels 7 and 8 whose outputs are connected with the inputs of difference stage 9. In order to decouple both the signal channels 7 and 8 from each other amplifiers 7a and 8a may be provided; sometimes only one of these amplifiers 7a and 8a is necessary. In one of the signal channels 7 and 8a storage means is provided, for instance in the channel 7a storage capacitor 7b is included. The storage means stores the value of the direct current voltage which is present at the output of stage 5 when the speed of approach v a is being initially measured and when the approaching target is still within a sufficiently large distance from the proximity detonator.
The resistors in FIG. 4 which are designated 9a, 9b and 9c, respectively, are provided in such a way as to realize the difference stage 9. The values of these resistors are preferably chosen equal to each other. Additionally a polarity converting stage is included in one of the signal channels 7 and 8, for instance a polarity converting stage 8b within the signal channel 8.
As soon as the difference between the electric potentials at the two inputs of the difference stage 9 reaches a predetermined value, the output signal of stage 9 enables a firing switch 14 to activate an igniting pellet 15 which initiates the detonation.
FIG. 5 shows another embodiment of the invention. This embodiment differs from that according to FIGS. 3 and 4 only in the substitution of an operation amplifier 16 for the difference stage 9. The operation amplifier 16 operates as a difference stage and subtracts the potential corresponding to v a from the potential corresponding to v r . In FIG. 5 it is assumed that firing value K z is a constant.
The input circuit of the operation amplifier 16 according to FIG. 6 may be used whenever the firing value K z will vary in dependence upon v r and v s , for instance according to the equation ##EQU11##
The input circuit according to FIG. 6 comprises a diode 17 shunted by a resistor 18, two diodes 19 and 20 a resistor 21, a further resistor 22 and a capacitor 23. The electrical dimensions of the circuit elements which are indicated in FIG. 6 are typical but not limiting and they may be modified in order to vary the firing value K z according to another predetermined law. A more advantageous embodiment of the invention is characterized in that the means for varying the firing value K z considers the angles of encounter by means of the characteristic geometric value K g . For this reason, the embodiment of the invention shown in FIG. 7 comprises an operation amplifier 24 having an additional input which is to be connected with the source (not shown) of the potential corresponding to the geometric value K g . The information necessary for producing a potential according to K g may be derived from signals in the target seeker of the flying body. The value K g and the speed values v r and v s may be considered by the means for varying the firing value K z according to the equation ##EQU12##
FIG. 8 shows another embodiment of the invention wherein the stages 1 through 3 and 14 through 15 are identical to those described in connection with FIG. 3. The output signal of the audio frequency amplifier 3 is the Doppler frequency f D and is fed to two discriminators 25 and 26. At the output of the frequency discriminator 25 a direct current voltage appears which is proportional to the value v r . This value is stored by means of storage device 27, the output of which is connected with the control input of a voltage controlled oscillator (VCO) 28. The frequency f VCO of the VCO 28 is used as a reference frequency within the phase discriminator 26 whose output signal actuates the firing switch 14 as soon as f D ≦f VCO . The embodiment according to FIG. 8 initiates the firing of the detonator when the speed of approach v a and the relative speed v r differ by a constant predetermined firing value K z .
FIG. 8a shows another embodiment of the invention which differs from that according to FIG. 8 by the insertion of a function converter means 29 between the VCO 28 and the storage device 27. That converter means 29 considers the dependence of the firing value K z upon the speed value v r .
Furthermore the geometric value K g may be fed into the converter means 29.
FIG. 9 illustrates the encounter between a flying body and its target showing the geometric relationships of the two bodies and including the speed vectors, the value v r being the difference between the speed vector v F of the flying body and the speed vector v Z of the target.
When considering the dynamic variations of the geometric relationships between the flying body and its target a coordinate system advantageously may be used the origin of which is based on the flying body, the ordinate of which coincides with the speed vector v r and the abscissa of which is oriented so that the target is moving in the x-y-plane (FIG. 10). The z-axis is added to form a right hand coordinate system.
The following definition apply:
δ=the angle between v F and v r (lead angle)
α=the angle between v r and the line of sight between the target and the flying body
φ=the angle between the x-axis and the component of v F in the x-z-plane (the passing flight angle)
r=the distance between target and flying body
Equation (9) has been derived on the condition that detonation should occur when the fragments will hit the target. This condition is equal to the condition that the relative velocity of the fragments is parallel to the line of sight. The relative velocity of the fragments is easily computed by vector addition of v r and v s with v s in most cases being perpendicular to the longitudinal axis of the flying body. Using the aforementioned conditions a short computation yields: ##EQU13##
The geometric value K g can as an example be generated by microcomputers contained in modern seeker heads. It should be noted that the lead angle is frequently used in seeker heads to adjust the guidance law and that the passing flight angle is delivered by measuring the latest movement of the antenna of the seeker head.
Other possibilities also exist to measure the lead angle and the passing flight angle and to perform the computation of equation (11).
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A proximity fuse, hereinafter called detonator for flying bodies, particularly missiles, to combat flying targets using speed information regarding the speed between detonator and target, wherein the firing of the detonator is initiated when the speed of approach v a and the relative speed v r differ by a firing value K z which is selected in dependence on the optimum point of firing where ##EQU1## and r=the location vector from detonator to target; ##EQU2## =the differential quotient after time t.
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BACKGROUND OF THE INVENTION
The invention relates to a transfer line for the metal-cutting machining of workpieces, in which a plurality of machining stations comprising tools together with their drives and guides are arranged one after the other substantially in one plane and transfer devices convey the workpieces to the machining stations in which the workpieces are held by clamping devices during machining.
Transfer lines of the type described above are known. They serve, for example, for the fully automatic machining of workpieces of essentially the same kind, for example engine blocks. In the individual machining stations of the transfer line, the various machining operations are performed by suitable machining units and tools. When the machining operations are completed, the transfer devices move the workpieces in an operating cycle to the next machining station.
As a rule, liquid cooling lubricants are employed for the machining operations, the function of which is to lubricate and cool the tools and also to flush away the cut-off cuttings. For this purpose, there is arranged beneath the workpiece-conveying path a channel which receives the cuttings and the coolant. The channel may be arranged either in the machine bed or on the floor on which the machining stations also stand, or a suitable underfloor channel or drain is provided. In the channel or drain, there are then provided conveying devices for the cuttings, for example screw conveyors, band conveyors, scraper conveyors, flap conveyors or else flushing nozzles, which carry the cuttings away.
The use of the cooling lubricant is relatively expensive. On the one hand, a high delivery rate is required, and on the other hand appropriate devices for maintaining a supply of and for cleaning the cooling lubricant are required.
An object of the present invention is to avoid the use of cooling lubricant as far as possible, especially as the wetting of the cuttings by the cooling lubricant is also undesirable.
BRIEF SUMMARY OF THE INVENTION
This and other objects of the invention are achieved in the invention by the provision of a transfer line for the metal-cutting machining of workpieces, in which a plurality of machining stations comprising tools together with their drives and guides are arranged one after the other substantially in one plane and transfer devices convey the workpieces to the machining stations in which the workpieces are held by clamping devices during machining, wherein the clamping devices which fix the workpieces are arranged above the workpieces and the workpieces hang down during the machining operation, and in that a falling and collecting space for the cuttings, which is kept free of clamping devices and machining heads, is arranged under the workpieces.
The arrangement according to the invention obviates the need for the cooling lubricant to flush away the cuttings which are produced. Insofar as cooling is actually required, this may be effected, for example, by an air-oil mixture or else by small amounts of an alcohol solution. The supply of suitable, small amounts of liquid is also recommended when machining special materials, such as, for example, aluminium, in order to avoid undesired build-up on the cutting edge or wear of the tools.
DETAILED DESCRIPTION OF THE INVENTION
In the invention, the cuttings fall into the falling and collecting space, which may be, for example, of funnel-like design. It is possible to arrange in this collecting space transporting or discharging devices of known type, which then convey the cuttings further by mechanical means. In this way, the cuttings are produced in a virtually dry state, with any oil-air mixtures or alcohol solutions, for example, which are employed evaporating or being sucked off without residue. The previously encountered problem, namely of the cuttings building up on the tools, the workpieces, their supports or pallets, or on the clamping devices, work tables, etc., is avoided.
In the invention, the transfer of the workpieces or the workpiece supports from one machining station to the next machining station may be performed in various ways. The transfer devices may comprise, for example, cyclically operating bars which act from above on the workpieces or the supports. It is however also possible to arrange the transfer devices beneath the workpieces. The transfer devices, for example cyclically operating bars, may be formed in such a way that a buildup of falling cuttings on these devices is not possible, in particular by virtue of the fact that the upward-facing surfaces of these devices are sufficiently inclined. It is however also possible to design the transfer devices such that they are withdrawn during the machining operation and thus do not obstruct the fall of the cuttings.
In general, the tools of a machining station are arranged on one or else on both sides of the transfer device or the respective machining space. In the invention, the guides for the machining units may in particular be aligned horizontally, so that the tools are brought on to the workpieces laterally.
In a preferred embodiment of the invention, the guides of the machining units are arranged such that they enclose an acute, outwardly open angle, preferably of 45°, with the horizontal. In this way, the guides for the machining units extend into a space above the workpieces, and this affords considerable advantages. It becomes possible to cover the machining space laterally by means of shields or plates, and the passageways for the machining heads of the machine tools need to be arranged only in the upper region. This ensures that the cuttings encounter largely smooth surfaces and that it becomes possible to carry the cuttings away without disruptions. A further advantage of this arrangement is that it becomes possible to reduce the overall height. Owing to the inclined arrangement of the feed guides, the horizontal space requirement is reduced. The additional vertical space requirement is not significant, since the required space must be available there anyway.
Although it was previously stated that in the invention the falling and collecting space for the cuttings is kept free of tools and the machining units and guides therefor, this does not preclude auxiliary devices, which are suitable and required for the positioning and clamping operation, from acting from below on the workpieces or their supports. These auxiliary devices can then be withdrawn for the machining operation, so that the advantage obtained by means of the invention is fully available.
In general, it is advisable to cover the machining space, in which the workpiece is arranged and in which the working head or heads project, by shields at the sides and also at the top.
In order to avoid considerable adjusting and assembly work, it is advantageous for the tool heads to be each provided with a shield which is movable with the tool head and which covers the gap to the adjoining shields. This mode of construction affords the advantage that, during fine adjustment of the tools with respect to the workpieces, the respective shield is moved in association with the tool head. This shield covers the gap which necessarily surrounds the tool head to ensure mobility and adjustability of the latter, and then forms the connection to the adjacent shields.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross-section through a transfer line according to the invention,
FIG. 2 shows a variant of the representation of FIG. 1,
FIG. 3 shows a cross-section through a transfer line in another embodiment,
FIG. 4 shows a variant of the representation of FIG. 3,
FIG. 5 shows a partial cross-section through a further variant, and
FIG. 6 shows a schematic plan view of a transfer line according to the invention on a considerably reduced scale.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the representation of FIG. 1, a schematically illustrated workpiece 1 is held on a support or a pallet 2. The pallet 2 is movable in a guide 3 of a frame or mount 4 and can also be positioned and fixed on this frame or mount 4 for the machining operation. The corresponding equipment for this is not shown specifically.
Above the pallet 2, that is to say also above the workpiece 1, there may be provided, as can be seen in FIG. 1, a transfer device 5 in the form of a cyclically operating bar, which for example is pivotable, so that during the feed stroke a carrier 6 takes the released pallet 2 along with it and displaces it, perpendicularly to the plane of the drawing, so that the next machining station is reached.
The machining station 7 comprises a machining head 8 on which a tool 28 is arranged. A slide 10 is movable in a guide 11 and, as is clearly evident in FIG. 1, the feed direction of the slide 10 on the guide 11 encloses an angle of about 45° with the horizontal. The pallet 2 is oriented accordingly, with the result that not only the pallet 2 and the associated guides 3 of the frame or mount 4 are arranged above the workpiece 1, but also the tool 28 together with the associated equipment.
The cuttings produced during machining can pass freely into a falling and collecting space 12, to which is connected a funnel 13 which conveys the cuttings into a channel 14 in which a transporting device (not illustrated specifically) is arranged.
Shields 16,17,18 and 19 define the top and sides of the machining space 15. The shields 18 and 19 are adapted, moreover, to fit the slide 10 and the guide 11. This gives the slide 10 the required mobility with the machining head 8. The mass of cuttings reaches the falling and collecting space 12 without difficulties. The few cuttings which are flung upwards as a rule do not encounter any plane surfaces. The discharging of the cuttings in the falling and collecting space 12 is not disrupted.
Instead of the cyclically operating bar 5, a transfer device 21 may be provided beneath the workpiece 1. This transfer device is designed to promote the flowing-off of the cuttings or projects into the machining space 15 only during the cycles. During the machining operation, however, it is withdrawn outside the space. As a result, the pallet 2, for example, may be dispensed with and the workpiece 1 supported directly by the transfer device 21.
In the variant shown in FIG. 2, the workpiece 1 is arranged essentially in the same manner in the machining station 33. A clamping device 22 is provided, by means of which the workpiece 1 is raised and firmly clamped during the transition from the transfer position to the machining position. The embodiment of FIG. 2 differs from that of FIG. 1 essentially in that there are provided two machining heads 8 which are each movable by means of a respective slide 10 on an inclined guide 11, thereby enabling simultaneous machining of the workpiece 1 from two sides by means of the two machining heads 8. The auxiliary device 23 facilitates the clamping operation and may, if necessary, be withdrawn for the machining operation.
In the embodiment of FIG. 3, there are provided two machining heads 9 which are directed substantially towards one another. The guides 11 of the associated slides 10 are substantially horizontally aligned and directed towards one another. In this way, two opposite surfaces of the workpiece 1 can be machined simultaneously, the workpiece in the embodiment of FIG. 3 being supported by a pallet 2 arranged symmetrically with respect to the centre axis 24. The shields 18 move in association with the machining units and cover the sides of the machining space 15.
The shield 16 covers the top of the machining space 15. Appropriate openings for the machining heads 9 are provided in the shields 18.
In the embodiment of FIG. 4, the machining space 15 is reduced in size. Parts of the frame or mount 4 are arranged outside the machining space 15. Suitable openings are provided in the shields 18 for the machining heads 9 and for tubular shields 25 movable in association with the respective machining head 9. Protective gratings 26 cover the guides 11 and the slides 10.
The variant of the invention of FIG. 5 shows two machining heads 8 which are inclined and carry the tools 28 used to machine the schematically illustrated workpiece 1. Under the workpiece, there is provided a transfer device 21 which is movable in the vertical direction (see double arrow 27) so that the workpiece 1 can be brought from a lowered transfer position to a raised clamping position, in which machining is carried out. The lowered position is indicated by broken lines 29. For fixing and positioning in the raised machining position, use is made of a pivotable clamping lever 30 and also a further clamping device 31, which is movable in the direction of the double arrow 32.
In the transfer line schematically illustrated in FIG. 6, three machining stations 7,33 and 34 are arranged one after the other. The arrow 35 indicates the direction of travel of the workpieces 1. These workpieces are initially connected at 36 to the schematically illustrated transfer device 21 in such a way that the workpieces 1 hang down from the transfer device. The transfer device 21 transports the workpieces in sequence through the individual machining stations until they are removed from the transfer device 21 at 37 and placed onto a conveying device 38.
Although the invention has been described in terms of specified embodiments which are set forth in considerable detail, it should be understood that this is by way of illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention.
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In a transfer line for the metal-cutting machining of workpieces, the transfer line including a plurality of machining stations arranged one after the other substantially in one plane. The workpieces are arranged in hanging fashion in such a way that clamping devices are arranged above the workpieces, thereby providing a falling and collecting space for the cuttings under the workpieces. Removal of cuttings is thereby facilitated and it is not necessary to flush the cuttings away using large amounts of coolant.
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TECHNICAL FIELD
[0001] This invention relates to a method and its apparatus for testing ionic conductivity. Particularly, it is a method for testing ionic conductivity from an electronic conductive material.
BACKGROUND TECHNIQUE
[0002] Electronic and ionic conductivity are one of the most important phenomena in the fields of energy materials, sensor devices, biological systems and so on. It is not only important for the efficiency of charge transport, but also relates to the chemical and electrochemical reaction mechanism and rates within the systems. At the meantime, it is also one of the determinative factors for the construction of electrochemical boundaries, and then dominates the performance, cost, and durability of the applied devices. In the fields of advanced energy technologies, including fuel cells, metal-air batteries and lithium ion batteries, the synergy of electron and ion transport is the key factor limiting the development. Therefore, efficient detection of ionic conductivity and electronic conductivity, as well as effective analysis of charge transport channels, is one of the key technologies for synthesis of electrode materials and structures.
[0003] The traditional measurements of electronic and ionic conductivity include the two-electrode and four-electrode ohms or electrochemical methods. With years of development, these techniques have been evolved as mature detection systems, and gained success in theoretical and applied aspects. However, in the current electrochemical systems including fuel cells, lithium ion batteries, and electrochemical sensors, the functions of electronic and ionic conductance usually exist synchronously in the microstructure of the electrode in the form of compound channels to ensure the high efficiency and utilization of the electrochemical boundaries and active components. Therefore, in the systems integrated with both the electronic and ion conductivity, it was found difficult to separate ionic conductance from the complicated series and parallel connections of electronic and ionic conductors with the traditional measurement equipped with metal probes. Specifically, the electronic conductivity of the electrode is usually greater than 1 S/cm, generally up to 10-10 3 S/cm, much higher than the ionic conductivity in the magnitude order of 10 −3 -10 −1 S/cm range. Conventional conductivity testing methods could hide signals of the ion conductance, and then render it impossible to separate efficiently. For this reason, finding a way to effectively separate the electronic conductance from the ionic conductance is critical to the development of advanced materials. On the other hand, the traditional ionic conductance detections are usually performed in the aqueous solution, which obviously differ from the applied environment in the electrode system and hardly reflect the convincible property of the ionic conductance. Therefore, the design and preparation of an conductivity testing instrument with controllable temperature and humidity could lay the foundation of analytical techniques for the development of electrode materials.
SUMMARY OF THE INVENTION
[0004] To aim at the deficiencies of the prior art, this invention has been devised as an ion conductive polymer modified four-probe detection apparatus to separate ion-/electron-conductance from the composite conductive materials. This detection apparatus includes an ion-conductive polymer modified probe and the ambient temperature and humidity controlling system, effectively solving the difficulty of the ion-/electron-conductance separation and the problem of environmental differences between measurement and applied status. This invention could accurately detect ionic conductance from the composite conductor materials, with precisely controlled temperature/humidity, increased reproducibility, simplified testing procedures, and enhanced measurement efficiency.
[0005] The invention adopts the following specific schemes:
[0006] An ionic conductance measuring device is comprising a voltage/current detection part and a test electrode; the test electrode is consisted of a block of substrate, four linearly arranged through holes on the substrate, four platinum wires inserted in the holes with the upper tips extended outside the block and the opposite tips withdrawn inside the block. The axes of the mentioned Pt wire are parallelly aligned in the same plane. The distance between the lower end surface of the platinum wires and the bottom surface of the block substrate is 0 . 1 - 2 mm. The gaps between the bottom ends of the Pt wires and the substrate are filled with the ion conductive polymer.
[0007] The voltage/current testing device is one of a potentiostat, ohmmeter, ammeter, constant voltage power supply, and a constant current meter.
[0008] The distance between the adjacent Pt wires is equal, and the diameters of the Pt wires are equal.
[0009] The substrate material is one of polytetrafluoroethylene, polyether ether ketone and polyethylene;
[0010] The ion conductive polymer is one of perfluorosulfonic acid polymer, sulfonated polyetheretherketone, quaternized polysulfone, and polybenzimidazole. Such polymers usually have the capability of ionic conductance or could perform ion migration under certain conditions;
[0011] The range of the measurement for ionic conductivity is 0.01 to 1000 Ω·cm. The range with minimized error is 0.05 to 100 Ω·cm;
[0012] The testing device also comprises a temperature/humidity controllable test box, which includes three airtight chambers: a dry gas chamber, a wet gas chamber and a testing chamber; To adopt the separated dry/wet gas chambers could effectively control the testing humidity without a humidity sensor and simplify the testing system;
[0013] The probes of the voltage/current testing device and the testing electrode are arranged in the testing chamber;
[0014] A gas inlet-A and a dry gas outlet are fixed on the dry gas chamber, and the inside of the dry gas chamber is filled with dehydration material; a gas inlet-B and a moist gas outlet are fixed on the wet gas chamber, and the deionized water is contained in chamber; The gas outlets of the dry and wet gas are connected to the testing chamber by tubes, and the inlets are connected to an gas supply source by gas flow meters.
[0015] The dry gas outlet and the wet gas outlet are connected with the test chamber pipeline through the three-way valve, and the three ports of the three-way valve are respectively connected with the testing chamber, the dry gas outlet and the wet gas outlet; the gas flow meters are one of the rotor flow rate meters, electromagnetic flow meters, and differential pressure flow meters.
[0016] The bottom of the test chamber is set with a water outlet, and the water outlet is set with a valve, and the water outlet can be opened or closed, and the water outlet can be opened to discharge liquid water in the test chamber.
[0017] The test chamber is provided with a sample test table, and the sample test table is drilled with several through holes, which can drain the liquid water to the bottom of the testing chamber. The upper side of the test chamber is provided with a switchable sample taking-out port.
[0018] The humidity controllable testing box is provided with a heat keeping device outside, and the dry gas chamber, wet gas chamber and testing chamber are all covered by the heat keeping device.
[0019] The temperature controlling and keeping device is one of a thermostatic water bath and a electric heating jacket.
[0020] The dry gas chamber, the wet gas chamber and the testing chamber are made of moisture resistant and heat resistant materials, and the moisture resistant and heat resistant material is one of organic glasses, polytetrafluoroethylene and stainless steel.
[0021] The method for measuring ionic conductivity using the testing device involves the followed steps:
[0022] (1) measuring the ionic conductance: a sliced thin piece of the testing sample is tightly pressed on bottom end of the testing electrode block; the second and third Pt wires in the test electrode are connected with the potential control terminal, and the first and forth Pt wires are connected with the current control terminal; a certain voltage is applied on the voltage testing terminal, and the response current is recorded; the same procedure is repeated at least twice;
[0023] (2) Data processing: the measured current is set as the abscissa, and the voltage is set as the ordinate. A plot of current-voltage is obtained, and the linear section near the zero potential part could be fitted. The slope d of the fitted curve is the ionic resistance of the sample to be measured;
[0024] The ionic resistivity p of the test sample can be calculated by p=Cd, where C is the correction factor and can be calculated as follow:
[0000] C= 2π/[1 /S 1 +1/ S 2 −1/( S 1 +S 2 )−1/( S 2 +S 3 )]
[0025] Where S 1 , S 2 and S 3 are the distance between the first Pt wire and the second Pt wire, the second Pt wire and the third Pt wire, the third Pt wire and the fourth Pt wire, respectively. And the conductivity of the sample to be measured is 1/ρ.
[0026] The applied voltage range in step (1) is −1V to 1V.
[0027] When the length of the test sample on the vertical scale to the Pt wires is more than 10 times of the distance between the Pt wires, it could be considered to meet the semi-infinite boundary condition, and the conductivity value can be calculated directly from the above equation.
[0028] When the ratio of the sample thickness and the distance between the Pt wires is less than 0.5, a correction curve is required by testing a series of samples to evaluate the relationships between the sample thickness and the testing positions.
[0029] The ionic conductivity test method can be used to measure the ionic conductivity of samples as carbon paper, carbon powder, carbon fiber, semiconductor, metal, or polymers.
[0030] The flow ratio Q A : Q B is equal to X:(1−X), where X is the preset humidity, 0≦X≦100%; and the flow rate ratio of the gas inlet A and the gas inlet B is simultaneously introduced;
[0031] The gas is one of nitrogen, argon, air, and oxygen.
[0032] The invention solves the problem that the ionic conductivity mixed in the electronic conductor is difficult to measure in the prior art. By adopting this method, the ionic conductance of the electronic conductors could be precisely measured and the ion migration of the materials could also be investigated. This measurement possesses the multi advantages of testing accuracy, stability of temperature and humidity, data reproducibility, simplified procedures and enhanced testing efficiency.
DESCRIPTION OF THE FIGURES
[0033] FIG. 1 . Schematic of the invention for the measurement of ionic conductivity; in this figure,
[0034] 1 . The insulative block; 2 . The Pt wires; 3 . The ion conductive polymer; 4 . The test sample; 5 . The voltage applying terminals; 6 . The current response terminals;
[0035] FIG. 2 : Test results for Example 1 and Example 2;
[0036] FIG. 3 : Test results for Example 3 and Example 4;
[0037] FIG. 4 : Schematic of the humidity-controlled test box;
[0038] FIG. 5 : (a) The test signals for conductivity of different samples by adopting unmodified four-probe method (control example 1 and 2); (b) The test signals for conductivity of different samples by adopting modified four-probe method (example 1 and 2); (c) the results of the conductivity tests of Example 1 and 2 and Control Example 1 and 2.
DETAILED DESCRIPTION
EXAMPLE 1
[0039] As shown in FIGS. 1 and 4 of the schematic of the test device, the cylindrical PTFE block with diameter of 2 cm is drilled along the axis out four linear through-holes with the diameter of 1 mm and the adjacent distance of 3 mm. Four Pt wires of the same diameters as the holes were fixed in the holes, and the end surface of the Pt wires was 1 mm from the end surface of the PTFE block. The 5% Nafion ionomer solution was applied dropwise onto the end surfaces of the Pt wires. After drying, the coating was repeatedly applied until the Nafion polymer solid completely covered the end surfaces of the Pt wires.
[0040] The middle two Pt wires of the test circuit are connected to the voltage test terminals (reference electrode 1 and 2 ) of the potentiometer, and the outer two Pt wires are connected to the current test terminal (working electrode and counter electrode).
[0041] a. Measurement of Ionic Conductance:
[0042] A dried Nafion 115 film with a size of 5×5 cm 2 is closely contacted with the Nafion ionomer modified end of the test electrode. The potential signals were applied to the voltage test terminals with a voltage range of −1 to 1 V, and the current response signals were then recorded at the current test terminals.
[0043] b. Data Processing:
[0044] The above measured current data are set as the abscissa, and the voltage data are set as the ordinate, and an approximate linear curve could be obtained as shown in FIG. 2 . The linear fitting of the curve near the zero potential is performed, and the slope d of the fitting curve is the test ion resistance of the sample.
[0045] The ionic resistivity of the material is corrected by ρ=Cd, and C is the correction factor. When the spacing S between the probes is equal,
[0000] C=2πS
[0046] The measured ionic conductivity of the non-humidified Nafion 115 membrane is about 0.026±0.004 S cm −1 .
COMPARATIVE EXAMPLE 1
[0047] The experiment is carried out by the unmodified four-probe method. The cylindrical PTFE block with diameter of 2 cm is drilled along the axis out four linear through-holes with the diameter of 1 mm and the adjacent distance of 3 mm. Four Pt wires of the same diameters as the holes were fixed in the holes, and the end surface of the Pt wires was 0.5 mm reaching out from the end surface of the PTFE block.
[0048] The middle two Pt wires of the test circuit are connected to the voltage test terminals (reference electrode 1 and 2 ) of the potentiometer, and the outer two Pt wires are connected to the current test terminal (working electrode and counter electrode).
[0049] a. Measurement of Ionic Conductance:
[0050] A dried Nafion 115 film with a size of 5×5 cm 2 is closely contacted with the Nafion ionomer modified end of the test electrode. The potential signals were applied to the voltage test terminals with a voltage range of −1 to 1 V, and the current response signals were then recorded at the current test terminals.
[0051] b. Data Processing:
[0052] The above measured current data are set as the abscissa, and the voltage data are set as the ordinate, and an approximate linear curve could be obtained. The linear fitting of the curve near the zero potential is performed, and the slope d of the fitting curve is the test ion resistance of the sample.
[0053] The ionic resistivity of the material is corrected by ρ=Cd, and C is the correction factor. When the spacing S between the probes is equal,
[0000] C=2πS
[0054] The measured ionic conductivity of the non-humidified Nafion 115 membrane is about 0.030±0.003 S cm −1 . This result is similar to that of the Example 1, and indicates the convincing test results of the measurement.
EXAMPLE 2
[0055] As shown in FIGS. 1 and 4 of the schematic of the test device, the cylindrical PTFE block with diameter of 2 cm is drilled along the axis out four linear through-holes with the diameter of 1 mm and the adjacent distance of 3 mm. Four Pt wires of the same diameters as the holes were fixed in the holes, and the end surface of the Pt wires was 1 mm from the end surface of the PTFE block. The 5% Nafion ionomer solution was applied dropwise onto the end surfaces of the Pt wires. After drying, the coating was repeatedly applied until the Nafion polymer solid completely covered the end surfaces of the Pt wires.
[0056] The middle two Pt wires of the test circuit are connected to the voltage test terminals (reference electrode 1 and 2 ) of the potentiometer, and the outer two Pt wires are connected to the current test terminal (working electrode and counter electrode).
[0057] a. Measurement of Ionic Conductance:
[0058] A piece of dry Cu foil, Al foil, carbon paper, gas diffusion layer(GDL), porous PTFE, porous PTFE/Nafion ionomer with a size of 5×5 cm 2 is closely contacted with the Nafion ionomer modified end of the test electrode. The potential signals were applied to the voltage test terminals with a voltage range of −1 to 1 V, and the current response signals were then recorded at the current test terminals.
[0059] b. Data Processing:
[0060] The above measured current data are set as the abscissa, and the voltage data are set as the ordinate, and an approximate linear curve could be obtained as shown in FIG. 5 a . The linear fitting of the curve near the zero potential is performed, and the slope d of the fitting curve is the test ion resistance of the sample.
[0061] The ionic resistivity of the material is corrected by ρ=Cd, and C is the correction factor. When the spacing S between the probes is equal,
[0000] C=2πS
[0062] The measured ionic conductivity of the samples is shown in FIG. 5 c.
COMPARATIVE EXAMPLE 2
[0063] The experiment is carried out by the unmodified four-probe method. The cylindrical PTFE block with diameter of 2 cm is drilled along the axis out four linear through-holes with the diameter of 1 mm and the adjacent distance of 3 mm. Four Pt wires of the same diameters as the holes were fixed in the holes, and the end surface of the Pt wires was 0.5 mm reaching out from the end surface of the PTFE block.
[0064] The middle two Pt wires of the test circuit are connected to the voltage test terminals (reference electrode 1 and 2 ) of the potentiometer, and the outer two Pt wires are connected to the current test terminal (working electrode and counter electrode).
[0065] a. Measurement of Ionic Conductance:
[0066] A piece of dry Cu foil, Al foil, carbon paper, gas diffusion layer(GDL), porous PTFE, porous PTFE/Nafion ionomer with a size of 5×5 cm 2 is closely contacted with the Nafion ionomer modified end of the test electrode. The potential signals were applied to the voltage test terminals with a voltage range of −1 to 1 V, and the current response signals were then recorded at the current test terminals.
[0067] b. Data Processing:
[0068] The above measured current data are set as the abscissa, and the voltage data are set as the ordinate, and an approximate linear curve could be obtained. The linear fitting of the curve near the zero potential is performed, and the slope d of the fitting curve is the test ion resistance of the sample.
[0069] The ionic resistivity of the material is corrected by ρ=Cd, and C is the correction factor. When the spacing S between the probes is equal,
[0000] C=2πS
[0070] The measured ionic conductivity of the samples is shown in FIG. 5 c . As demonstrated by the results, this measurement effectively blocks the conductance of electrons, while maintains the conductance of ions, which can successfully separate ionic conductance from electronic conductors.
EXAMPLE 3
[0071] The testing instrument is the same as Example 1.
[0072] a. Measurement of Ionic Conductance:
[0073] A humidified Nafion 115 film with a size of 5×5 cm 2 is closely contacted with the Nafion ionomer modified end of the test electrode. The potential signals were applied to the voltage test terminals with a voltage range of −1 to 1 V, and the current response signals were then recorded at the current test terminals.
[0074] b. Data Processing:
[0075] The above measured current data are set as the abscissa, and the voltage data are set as the ordinate, and an approximate linear curve could be obtained as shown in FIG. 2 . The linear fitting of the curve near the zero potential is performed, and the slope d of the fitting curve is the test ion resistance of the sample.
[0076] The ionic resistivity of the material is corrected by ρ=Cd, and C is the correction factor. When the spacing S between the probes is equal,
[0000] C=2πS
[0077] The measured ionic conductivity of the humidified Nafion 115 membrane is about 0.128±0.012 S cm −1 .
EXAMPLE 4
[0078] The testing instrument is the same as Example 1.
[0079] a. Measurement of Ionic Conductance:
[0080] A carbon paper with a size of 5×5 cm 2 is closely contacted with the Nafion ionomer modified end of the test electrode. The potential signals were applied to the voltage test terminals with a voltage range of −1 to 1 V, and the current response signals were then recorded at the current test terminals.
[0081] b. Data Processing:
[0082] The above measured current data are set as the abscissa, and the voltage data are set as the ordinate, and an approximate linear curve could be obtained as shown in FIG. 2 . The linear fitting of the curve near the zero potential is performed, and the slope d of the fitting curve is the test ion resistance of the sample.
[0083] The ionic resistivity of the material is corrected by ρ=Cd, and C is the correction factor. When the spacing S between the probes is equal,
[0000] C=2πS
[0084] The measured ionic conductivity of the carbon paper is about 4.17±0.09 mS cm −1 , which indicates that the influence of the electronic conductance is largely separated.
EXAMPLE 5
[0085] The testing instrument is the same as Example 1.
[0086] a. Measurement of Ionic Conductance:
[0087] A carbon paper dipped with 5% Nafion ionomer with a size of 5×5 cm 2 is closely contacted with the Nafion ionomer modified end of the test electrode. The potential signals were applied to the voltage test terminals with a voltage range of −1 to 1 V, and the current response signals were then recorded at the current test terminals.
[0088] b. Data Processing:
[0089] The above measured current data are set as the abscissa, and the voltage data are set as the ordinate, and an approximate linear curve could be obtained as shown in FIG. 2 . The linear fitting of the curve near the zero potential is performed, and the slope d of the fitting curve is the test ion resistance of the sample.
[0090] The ionic resistivity of the material is corrected by ρ=Cd, and C is the correction factor. When the spacing S between the probes is equal,
[0000] C=2πS
[0091] The measured ionic conductivity of the carbon paper is about 20.83±0.56 mS cm −1 , which indicates the capability of ionic conductance of the materials and eliminates the electronic conductance.
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An ionic conductance measuring instrument comprising a voltage/current test device and a test electrode, in which the test electrode comprises a bulk substrate with four linearly arranged through holes, four Pt wires inserted in the through holes respectively with their upper ends exposed outside of the bulk and their downside ends hidden inside of the bulk; the four axis of the Pt wire is in the same plane and parallel with each other; the gap distance between the mentioned Pt wire and the bulk substrate is 0.1-2 mm, and is filled with ionic conductive polymer.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a divisional of application Ser. No. 13/248,798 filed Sep. 29, 2011.
BACKGROUND OF THE INVENTION
[0002] The present invention is generally directed to farm implements and, more particularly, to a method and apparatus for maintaining a level orientation of a bulk fill hopper frame.
[0003] Increasingly, farm implements have been designed to have frames that can be folded between field-working and transport positions. One such type of farm implement is a stack-fold planter, such as the 1230 Stackerbar planter from Case New Holland, LLC. Stack-fold planters generally consist of a center frame section and a pair of wing frame sections. in the field-working position, the wing frame sections are evenly aligned with the center frame section. In the transport position, however, the wing sections are lifted to a position directly above the center frame section, i.e., to a “stacked” position. In the stacked position, the width of the implement is generally that of the center frame section, thus making the implement better suited for transport along roads and between crops.
[0004] Openers are mounted to the frame sections at equal intervals, with each of the wing sections typically carrying one-half the number of openers mounted to the center frame section. The openers are designed to a cut a furrow into a planting surface, deposit seed and/or fertilizer into the furrow, and then pack the furrow. In this regard, each opener will have a seed box that is manually loaded with seed and/or fertilizer. Since the size of the seed box determines how much particulate matter the box can retain, there is generally a desire to have larger seed boxes for each of the openers. Since the larger seed boxes can hold more material, fewer refilling stops are needed when planting a field.
[0005] Larger seed boxes, however, have drawbacks. The additional material that can be carried by larger seed boxes adds to the overall weight of the openers, including those mounted to the wing sections. This additional weight can stress the lifting/lowering system that stacks the wing sections, or require a more robust system, which can add to the overall size, mass, complexity, and cost of the implement. Larger spacing between seed trenches lower per acre crop yields. Further, it can be problematic and time consuming to individually fill each of the seed boxes, whether using bags or a conveyor system.
[0006] Accordingly bulk fill systems have been designed for stack-fold planters that generally consist of one or more bulk fill tanks mounted to a frame or toolbar that can be coupled to the frame of the stack-fold planter. The frame for the bulk fill system is supported above the ground by a lift wheel assembly that is designed to raise the frame when the stack-fold planter is in transport. Oftentimes, an operator will also raise the bulk fill system frame at headland turns when the gull wings are also raised to provide additional implement stability.
[0007] Raising the gull wings and the frame for the bulk fill hopper(s) at headland turns poses one of the challenges that is faced by an operator when making a headland turn onto a new swath. More particularly, as the operator of a planter arrives at the headland of a field, the operator has to perform numerous tasks to reposition the planter in the next swath. Many of these tasks require the operator to attempt simultaneous control of three or more operations. For stack-fold planters equipped with lift assist wheels and/or gull wings, the operator needs to retract the gull wings to prevent the wings from drooping when lifted from the ground, elevate the three-point hitch that connects the stack-fold planter to the towing vehicle e.g., tractor, and extend the lift wheel assembly to raise the bulk fill system. The operator will also need to slow the tractor by shifting and/or reducing engine speed. By requiring the operator to perform these tasks substantially simultaneously, the operator can become mentally and physically fatigued, require an enhanced skill level to operate the stack-fold planter, increase the likelihood that the operator may make an error, or reduce the performance of the stack-fold planter at headland turns.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to a method and apparatus for automating some of the tasks that heretofore required operator action at headland turns or similar events. For example, in one embodiment, the present invention automates operation of lift assist wheels and/or gull wings, such as those found on a stack-fold implement, based on the position of the tractor hitch to which the implement is coupled. Accordingly, an operator may control the position of the implement, such as at a headland turn, by raising and lowering the tractor hitch using a conventional remote control. The invention enables the planter to compare the tractor hitch position relative to an implement position and control operation of the implement accordingly without additional user inputs.
[0009] In accordance with one aspect of the invention, a farm implement has a toolbar configured to be coupled to a towing vehicle and a bulk fill hopper mounted to a frame that is supported by a lift wheel assembly. The farm implement further has a connector for coupling the toolbar to a hitch of the towing vehicle. A first electrical input receives a hitch position signal from the towing vehicle and a second electrical input receives a frame position signal. The implement further has an electronic control unit (ECU) that receives the hitch position and the frame position signals and automatically activates the lift wheel assembly to maintain the frame in a level position as the vertical position of the connector changes.
[0010] In accordance with another aspect of the invention, a farm implement having a frame supported by a lift wheel assembly comprises a connector for coupling the toolbar to the ISOBUS hitch of a towing vehicle, a first electrical input that receives a hitch position signal from the tractor, an electric over hydraulic valve that controls hydraulic fluid flow from the hydraulic system to the lift wheel assembly, and an electronic control unit (ECU). The ECU receives the hitch position signal and provides a command signal to the electric over hydraulic valve to control hydraulic fluid flow in the hydraulic system to raise the frame when the hitch is in a raised position.
[0011] The present invention is also embodied in a method for automatically leveling a farm implement having a frame and being towed by a tractor that is coupled to the farm implement by a hitch. The method, which is preferably carried out automatically using various electronics, includes receiving a hitch position signal from the tractor and receiving a frame position signal from a sensor that detects a position of the frame. The method further includes the step of automatically raising or lowering the frame in response to changes in hitch position of the tractor.
[0012] Other objects, features aspects, and advantages of the invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout.
[0014] In the drawings:
[0015] FIG. 1 is a pictorial view of an agricultural planting system comprised of a stack-fold planter coupled to a tractor;
[0016] FIG. 2 is an isometric view of the stack-fold planter of FIG. 1 in a field-working (float) position;
[0017] FIG. 3 is a rear elevation view of the stack-fold planter of FIG. 1 in a stacked, transport position;
[0018] FIG. 4 is an isometric view of the central bulk fill system of FIG. 1 in a lowered, field working position;
[0019] FIG. 5 is a schematic block diagram of a hydraulic control system according to one embodiment of the invention; and
[0020] FIG. 6 is a schematic block diagram of a hydraulic control system according to another embodiment of the invention.
DETAILED DESCRIPTION
[0021] As will be made apparent from the following description, the present invention provides an apparatus that automatically adjusts the position of an implement in response to changes in the position of the hitch of a tractor towing the implement. For purposes of description, the invention will be described with respect to a stack-fold planter, such as that shown in FIGS. 1-4 , but it is understood that the invention is applicable with other types of implements. The invention, which can also be embodied in an automated method, is designed to reduce the number of user inputs that were heretofore required to command movements of the implement, such as at headland turns.
[0022] Turning now to FIGS. 1-4 , a planting system 10 includes a stack-fold implement 12 , shown in a field working position, coupled to a prime mover 14 , e.g., tractor, in a known manner. For purposes of illustration, the stack-fold implement 12 is a row crop planter, which as shown in FIG. 2 , includes a frame 16 generally comprised of a center section 18 and wing sections 20 , 22 on opposite lateral sides of the center section. The center section 18 includes a tongue (not shown) that extends forwardly of the center section 18 for hitching the implement 12 to the prime mover 14 . As will be described more fully below, the implement 12 is coupled to a three-point hitch of the prime mover 14 . Gauge wheels 24 on the frame sections 18 , 20 , and 22 set the seeding or cutting depth for the implement.
[0023] In the illustrated embodiment, sixteen openers 26 are mounted to the frame 16 at equally spaced intervals, but it is understood that more than or fewer than sixteen openers could be mounted to the frame 16 . As known in the art, the wing sections 20 , 22 may be raised to a transport position, as shown in FIG. 3 , in which the openers carried by the wing sections 20 , 22 are stacked over the center section 18 . As also known in the art, the openers 26 are designed to cut a furrow into the soil, deposit seed and/or fertilizer into the furrow, and then pack the furrow. Seed boxes or “mini-hoppers” 28 are optionally mounted to each of the openers 26 . The mini-hoppers 28 are preferably smaller than conventional mini-hoppers used with stack-fold crop row planters and thus hold less material than conventional seed boxes.
[0024] The smaller mini-hoppers are flow-coupled to a central bulk fill assembly 30 that delivers material, such as seed and/or fertilizer, to the openers 26 and/or the mini-hoppers 28 . The central bulk fill assembly 30 preferably includes a pair of bulk fill hoppers 32 and 34 supported adjacently to one another on a frame 36 . The frame 36 is coupled to the center section 18 by a set of rearwardly extending frame members 38 , 40 , and 42 connected to a crossbar 44 . In a preferred embodiment, the frame members 38 , 40 , 42 are removably coupled to center frame section 18 which allows the bulk fill assembly 30 to be removed from the implement 12 or added as an after-market add-on to an existing stack-fold implement.
[0025] The frame 36 is supported above the work surface (or transport surface) by a pair of wheels 46 , 48 that are each connected to the frame by a wheel lift assembly 50 , which in the illustrated embodiment includes a pair of parallel linkages 52 , 54 . Each linkage includes upper links 56 , 58 and lower link 60 , 62 , respectively. In addition to the links 56 - 62 , a pair of lift arms 64 , 66 are provided. Lift arm 64 is coupled to frame member 42 at a knuckle 68 to which parallel linkage 52 is also connected. In a similar manner, lift arm 66 is coupled to frame member 38 at a knuckle 70 to which parallel linkage 54 is also connected. As shown particularly in FIG. 4 , the frame 36 farther includes a Y-beam 72 that is pivotally coupled to the center frame member 40 . As is customary for most central bulk fill assemblies, an air blower 74 is mounted beneath the bulk fill hoppers and is operable transfer particulate matter from the hoppers 32 , 34 to the individual mini-hoppers 28 or directly to the openers 26 in a forced air stream.
[0026] As known in the art, central bulk fill hoppers, such as those described above, provide the convenience of a central fill location rather than having to fill the individual seed boxes. Also, the central fill hoppers have greater capacity than the seed boxes, which reduces the number of fill iterations that must be taken when planting. Simply mounting a central bulk fill assembly to a stack-fold planter, such as planter 12 , can create stability issues, especially when the stack-fold planter is in the transport position. In this regard, the present invention provides a mechanism for raising the bulk fill assembly 30 when the stack-fold planter 10 is in the folded, transport position. Raising the bulk assembly 30 provides greater stability during transport as well provides increased clearance between the bulk fill assembly 30 and the roadway.
[0027] A pair of hydraulic lift cylinders 76 and 78 are operable for lifting the frame 36 , and thus the bulk fill assembly 30 . Cylinder 76 is interconnected between forward knuckle 68 and a rearward knuckle 80 . As shown in FIG. 4 , the rearward knuckle 74 includes, or is coupled to, a mounting arm 82 that is coupled to axle 84 about which wheel 46 rotates. Cylinder 76 includes a ram 86 that is coupled to the rearward knuckle 80 whereas cylinder 76 is coupled to the forward knuckle 68 . In a similar fashion, cylinder 78 includes a ram 88 connected to a rearward knuckle 90 whereas the cylinder 78 is connected to the forward knuckle 70 . It will be appreciated that a mounting arm 92 is connected to, or formed with, the rearward knuckle 90 , and the mounting arm 92 is connected to an axle (not shown) about which wheel 48 rotates.
[0028] As known in the art, central bulk fill hoppers, such as those described above, provide the convenience of a central fill location rather than having to fill the individual seed boxes. Also, the central fill hoppers have greater capacity than the seed boxes, which reduces the number of fill iterations that must be taken when planting. Simply mounting a central bulk fill assembly to a stack-fold planter, such as planter 12 , can create stability issues, especially when the stack-fold planter is in the transport position. In this regard, the present invention provides a mechanism for raising the bulk fill assembly 30 when the stack-fold planter 10 is in the folded, transport position. Raising the bulk assembly 30 provides greater stability during transport as well provides increased clearance between the bulk fill assembly 30 and the roadway.
[0029] Turning now to FIG. 5 , the present invention provides a communications apparatus 94 for use with a prime mover equipped with ISO 11783 technology. The communications apparatus 94 includes datalink 96 that communicatively links an implement electronic control unit (ECU) 98 with electronics 100 of the prime mover 14 . The datalink 96 may be a wireless connection or, as shown in FIG, 5 . a wired communication consisting a connector 102 tethered by cable 104 to the electronics 100 and a receiver 106 tethered by cable 108 to ECU 98 . In a preferred embodiment, the connector 102 and the receiver 106 are ISO 11783 components that permit the transfer of data between the prime mover electronics 100 and the ECU 98 . Thus, it will be appreciated that the datalink 96 provides an ISOBUS connection between the prime mover 14 and the stack-fold implement 12 .
[0030] The ISOBUS connection enables the transmission of various data between the stack-fold implement 12 and prime mover 14 . One type of data is hitch position information. The prime mover 14 has a hitch position sensor 110 that provides feedback to the electronics 100 of the prime mover 14 as to the vertical position of the coupling between the stack-fold implement 12 and the prime mover 14 . In one embodiment, this coupling is a three-point hitch. The prime mover electronics 100 provides a data signal to the ECU 98 via datalink 96 containing hitch position information. In accordance with one aspect of the invention, the ECU 98 adjusts the vertical position of the stack-fold implement 12 accordingly.
[0031] More particularly, the stack-fold implement 12 has a frame position sensor 112 that measures the vertical position of the central bulk fill assembly 30 . In one preferred embodiment, the vertical position is determined from the angle between frame 36 and the wheel lift assembly 50 . It is contemplated that a number of sensors may be used to measure this angle including, but not limited to, rotary potentiometers, displacement sensors, optical sensors, strain gauges, pressure sensors, and the like. For example, in one embodiment, the frame position sensor 112 measures the displacement of either hydraulic lift cylinder 76 or hydraulic lift cylinder 78 .
[0032] The ECU 98 receives the frame position signal from the frame position sensor 112 and compares the frame position of the stack-fold implement 12 with the vertical position of the hitch, as provided in the hitch position signal. From this comparison, the ECU 98 raises or lowers the central bulk fill assembly 30 to level the central bulk fill assembly 30 in light of the changes in vertical position of the prime mover hitch.
[0033] In one embodiment of the invention, the central bulk fill assembly 30 is raised or lowered by ECU 98 controlling operation of an electric over hydraulic valve 114 . The hydraulic valve 114 is interconnected between the hydraulics 115 of the prime mover 14 and the hydraulics of the stack-fold implement 12 , which include the pair of hydraulic lift cylinders 76 , 78 . Thus, the hydraulic valve 114 , upon receipt of a corresponding command signal from the ECU 98 , can increase or decrease the pressure in the pair of hydraulic lift cylinders 76 , 78 to raise or lower, respectively, the central bulk fill assembly 30 . It is highly desirable to increase the elevation of the central bulk till assembly 30 when the hitch is raised and, conversely, lower the elevation when the hitch is lowered.
[0034] In a further embodiment of the invention, also shown schematically in FIG. 5 , the wing sections 20 , 22 are moved automatically based on the vertical position of the three-point hitch. As known in the art, the hydraulic components, including lift actuators 116 , 118 , are used to raise and lower the left wing section 22 (“left side gull wing”) and the right wing section 20 (“right side gull wing”), respectively. In this further embodiment, the ECU 98 also provides command signals to the left and right lift actuators, which can be of conventional design. In a preferred embodiment, the lift actuators are hydraulic cylinders whose operation is controlled by a valve, such as hydraulic valve 114 . As such, the ECU 98 provides control commands to the hydraulic valve 114 which in turn controls operation of the lift actuators preferably in synchrony with the wheel lift, assembly 50 .
[0035] It will be appreciated that the wing sections are movable between a field working position, such as illustrated in FIG. 2 and a retracted or raised position, such as illustrated in FIG. 3 . In the field working position, the wing sections (as well as the center section) are free to float so to respond to changes in surface contours. In this regard, the ECU 98 commands the electric over hydraulic valve 114 to control hydraulic fluid flow in the hydraulic system to move the wing sections to the float position when the hitch is in a fully lowered position.
[0036] It will also be appreciated that in the embodiment illustrated in FIG. 5 , the operator of the tractor, i.e., towing vehicle, using conventional hydraulic remotes, pressurizes the tractor's hydraulic system to which the hydraulics of the implement are flow-coupled and thus also pressurized. As such, the operator must manually operate the hydraulic remotes to supply the hydraulic power needed to operate the lift actuators for the gull wings and the central bulk fill assembly.
[0037] In contrast, and referring now to FIG. 6 , a communications apparatus 120 according to an alternate embodiment of the invention controls operation of the hydraulic remotes automatically, i.e., uses the tractor hydraulics 122 to directly control operation of the wheel lift assembly 50 and the lift actuators 116 , 118 rather than control an electronic-over-hydraulic valve 114 . More particularly, the hitch position sensor 110 provides hitch position data to the implement ECU 98 across ISOBUS connection 96 . The implement ECU 98 uses the hitch position information together with frame position data read from the frame position sensor 112 and provides control commands to the hydraulic remote(s) 124 , which are connected to the tractor hydraulics 122 in a known manner. The tractor hydraulics are flow-coupled to the actuators of the wheel lift assembly 50 and the lift actuators 116 , 118 . It is understood that the actuators could be independently flow coupled to the tractor hydraulics, but preferably, a single supply conduit 126 and return conduit 128 that are coupled to a manifold 130 or similar distribution device to which the actuators for the wheel assembly and the lift actuators are flow coupled in a conventional manner. It will thus be appreciated that in the embodiment illustrated in FIG. 6 , the implement controls the hydraulics of the tractor based on commands transmitted to the tractor via the ISOBUS connection.
[0038] It will be appreciated that in one embodiment of the invention, the position of the tractor hitch is used to adjust the vertical position of the implement frame. It is understood however that in another embodiment, the vertical position of the implement frame could be monitored to cause automatic adjustment of the tractor hitch.
[0039] Many changes and modifications could be made to the invention without departing from the spirit thereof. The scope of these changes will become apparent from the appended claims.
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A method and apparatus for automating some of the tasks that heretofore required operator action at headland turns or similar events are provided. The present invention automates operation of lift assist wheels and/or gull wings, such as those found on a stack-fold implement, based on the position of the tractor hitch to which the implement is coupled. An operator may control the position of the implement, such as at a headland turn, by raising and lowering the tractor hitch using a remote control. The invention enables the planter to compare the tractor hitch position relative to an implement position and control operation of the implement accordingly without additional user inputs.
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FIELD OF THE INVENTION
The present invention relates generally to shooting targets for use with handguns, shotguns, and rifles, and more particularly, to a rotary shooting target that has a plurality of impact paddle-like plates which define continually moving targets in response to being struck by bullets during usage.
BACKGROUND OF THE INVENTION
Vertical rotary shooting targets are known which comprise a stand having a horizontal axle on which a hub is rotatably mounted from which support rods extend radially on diametrically opposed sides of the hub. Each radial support rod carries a target in the form of a paddle-like impact plate made of hardened steel fixed to a side thereof, with the impact plates being mounted on opposite lateral sides of the radial support rods. When a shooter sequentially hits the targets, the hub, support rods and impact plates rotate about the axis in a vertical plane, creating rapidly moving targets for rapid fire practice.
When a bullet hits the impact plate, a splash cone is created which can cause particles of handgun bullets to splash and deflect more than 20 yards and rifle bullets can deflect 75 yards and more. When the bullet strikes a vertical junction between the support rod and the impact plate affixed thereof, lateral and rearward splashback can occur which can strike shooters located downwardly along a firing line. Moreover, the splashback can strike and damage the hub, axle, and stand, which are not made of impact resistant hardened steel. Since the impact plate and hubs are welded to the connecting rod, which can create stress cracks in the joint area, the junction areas can be susceptible to failure after repeated impact, as is the case in rotating targets of such type which are used for rapid shooting practice.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a vertical rotary shooting target adapted for more effectively preventing harmful splashback of bullet fragments along a shooting line.
Another object is to provide a vertical rotary shooting target as characterized above which minimizes splashback of bullet fragments which can damage the stand and support structure in the rotary target.
A further object is to provide a vertical rotary target of the foregoing type which provides more challenging rapid fire practice in sequential shooting.
Still another object is to provide a vertical rotary shooting target of the above kind which is adapted for more economical construction and long-term reliable usage. A related object is to provide such a rotary target which eliminates the necessity for welding structural components of the rotary targets at locations where stress cracks can occur that are susceptible to failure during usage of the target.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawing, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective of an illustrative rotary target in accordance with the invention being used on a shooting line.
FIG. 2 is an enlarged front elevational view of the rotary target shown in FIG. 1 ;
FIG. 3 is a vertical section of the illustrated rotary target taken in the plane of line 3 — 3 in FIG. 2 ;
FIG. 4 is an enlarged fragmentary section showing the connection of impact paddle support rods to a rotary hub of the device;
FIG. 5 is a front elevational view of an alternative embodiment of rotary target in accordance with the invention; and
FIG. 6 and FIG. 7 are enlarged fragmentary sections of the rotary target shown in FIG. 5 , taken in the planes of lines 6 — 6 and 7 — 7 respectively.
While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now more particularly to FIGS. 1–4 of the drawings, there is shown an illustrative vertical rotary target 10 embodying the present invention, comprising a conventional stand 11 and a rotary target support structure 12 . The stand 11 in this instance comprises a pair of side legs 14 which support a horizontal axle rod 15 . The legs 14 have respective collars 16 at their upper ends through which opposing ends of the axle rod 15 extend, with removable split pins 18 retaining the axle rod 15 in mounted position.
The rotary target support structure 12 comprises a hub 20 rotatably mounted centrally on the axle rod 15 , and a pair of target support members in the form of rods 21 extending radially from diametrically opposed sides of the hub 20 . The target support rods 21 in this instance are welded in a butting relation to opposite sides of the hub 20 and further retained by means of a pair of reinforcement support rods 22 each welded to respective ends of the support rods 21 on opposite sides of the hub. The hub 20 is maintained centrally on the axle rod 15 by pins 24 , and an appropriate bushing may be provided between the hub 20 and axle rod 15 facilitating relative rotational movement of the hub 20 . Hence, it can be seen that the target support structure 12 can be rotated relative to the axle rod 15 .
In accordance with the invention, the target support members each include a laterally extending horizontal section which supports a target in the form of an impact plate in a manner which prevents and/or substantially minimizes harmful bullet splashback that can harm persons on the shooting line or damage to the structure of the rotary target. To this end, in the illustrated embodiment, each target support rod 21 includes a radial section 21 a connected to the hub 20 , a horizontal target supporting section 21 b , and an angled section 21 c interconnecting the radial and horizontal sections 21 a , 21 b . Each target is in the form of a rectangular or square impact plate 30 made of hardened, impact resistant steel capable of withstanding impact from rifle and handgun bullets. The impact plates 30 in this case are welded to outer radial sides of the horizontal support rod sections 21 b . Hence, as depicted in FIG. 2 , when an impact plate 30 is in an upper position and it is on an upper side of the horizontal support rod section 21 b and when the impact plate 30 in the lower position it is on an underside of the horizontal support rod section 21 b.
It will be seen that when an impact plate 30 is in an upper position and a bullet strikes the impact plate at the juncture between the impact plate 30 and the horizontal support rod section 21 b fragments will tend to be deflected by the support rod section 21 in a substantial vertical direction, in contrast to the prior art in which vertical support rods that support the impact plates deflect bullet splashback laterally in a direction that could affect other shooters on the firing line. The horizontal support rod section 21 b , when in such upper position, further tends to prevent deflection of the splashback in a downward direction that can damage the stand 11 or the rotary target support structure 12 . Likewise, when the impact plate 30 is in a lower position, as depicted in FIG. 2 , bullet fragments striking the impact plate 30 at the junction between the impact plate 30 and the horizontal support rod section 21 b will be deflected downwardly toward the ground, again in a manner which will not cause harmful splashback to participants on the firing line or damage to the structure of the rotary target.
In carrying out a further feature of the invention, the target impact plates 30 are supported by the horizontal support rod sections 21 b in outward laterally spaced relation to the plane of the radial support rod sections 21 a for increased horizontal separation between the impact plates 30 and enhanced shooting practice difficulty. In the illustrated embodiment, the impact plates 30 are disposed a distance “x” laterally outwardly of the radial support rod section 21 a of about one-half the width “w” of the impact plate 30 , hence creating a lateral separation corresponding to about the horizontal width “w” of the impact plates 30 . It will be seen that rotary target provides more challenging sequential shooting by virtue of the increased horizontal spacing between the impact plates 30 during repetitive alternate shooting.
Referring now to FIGS. 5–7 , there is shown an alternative embodiment of rotary shooting target in accordance with the invention, wherein items similar to those described above have been given similar reference numbers with the distinguishing “prime” added. The rotary target 10 ′ includes a stand 11 ′ similar to that described above and a rotary target support structure 12 ′ which is adapted for more economical manufacture and even more effective prevention of undesirable bullet splashback. The rotary target support structure 12 ′ again include a hub 20 ′ supported on an axle rod 15 ′ of the stand for relative rotational movement in a vertical plane.
In keeping with this embodiment of the invention, the rotary target includes target impact plate and support structures connected to the rotary hub 20 ′ defined by unitary plates 35 of hardened impact resistant steel. Each plate 35 defines both a generally rectangular impact plate 30 ′ and a support member 21 ′ for supporting the impact plates 30 ′ radially outwardly of the hub 20 ′ in laterally spaced relation to a central radial axis by a distance by at least one-half the width of the impact plates. The support members 21 ′ in this case include a radial plate section 21 a ′ coupled to the hub 20 ′ and an inclined plate section 21 c ′ interconnecting the radial plate section 21 a ′ and the impact plate 30 ′. The radial plate section 21 a ′ of the lower plate depicted in FIG. 5 again is longer than the radial plate section of the upper plate for assuring a neutral vertical position of the target when not in use.
For affixing the target defining plates 35 to the rotary hub 20 ′, tubular members 38 are welded on sides of the hub 20 a ′. The radial plate sections 21 a ′ of the target defining plates 35 each are positionable along opposite sides of the tubular members 38 and are secured together and to the channels by removable fasteners in the form of bolts 39 .
It will be appreciated by one skilled in the art that since the impact plates 30 ′ and support members 21 ′ are defined by respective unitary, coplanar plates 35 , there are no joints, such as the juncture between impact plates and cylindrical support rods, that can increase potentially harmful splashback deflection to persons on the firing line. Since none of the structural members of the rotary support structure 12 ′ necessitate welding, there also are no stress cracks or other weld created defects that can affect the structural integrity of the rotary target at locations that are the subject of repetitive shooting impact. Moreover, since the target defining plates 35 can be easily bolted to the rotary hub 20 ′, the rotary target lends itself to easy manufacture and field assembly.
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A vertical rotary shooting target having a stand with a horizontally extending axial which supports a rotary target structure. The vertical rotary target structure includes a hub rotatably mounted on the axial, a pair of target impact plates, and a support structure connecting the impact plates radially outwardly on diametrically opposed sides of the said hub and in horizontally spaced relation for enhanced shooting difficulty. Alternative embodiments of impact plate support structures are disclosed which minimize potentially harmful and damaging splashback of bullets striking the impact plates.
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FIELD OF THE INVENTION
[0001] This invention relates to enteric coatings for encapsulated orally ingestible compositions exemplified by pharmaceutical compositions, nutraceutical compositions, nutritional supplements, foodstuffs and the like. More particularly, this invention relates to enteric coating compositions and to methods for applying said enteric coating compositions.
BACKGROUND OF THE INVENTION
[0002] There are many enteric coating materials currently available for use as outer coatings on capsules and tablet formulations containing chemically stable pharmaceutical compositions. Examples of such enteric coating materials include Aquacoat® CPD (Aquacoat is a registered trademark of the FMC Corporation), Eudragit® methacrylic copolymers (Eudragit is a registered trademark of Rohm & Haas G.M.B.H. Co.), Kollicoat® MAE (Kollicoat is a registered trademark of the BASF Aktiengesellschaft Corp.), Acryl-EZE® (Acryl-EZE is a registered trademark of BPSI Holdings Inc.), Opadry® (Opadry is a registered trademark of BPSI Holdings Inc.), and Sureteric® (Sureteric is a registered trademark of BPSI Holdings Inc.). Each of the afore-mentioned enteric coating materials is a proprietary formulation. However, there has been an emergence of significant market and consumer demands for novel chemical and biological-based pharmaceutical, nutraceutical and nutritional supplement compositions that are less stable and therefore, present new challenges for enteric coating materials with regard to: (a) post-manufacture chemical compatibility, stability and storage properties, (b) post-ingestion functionality, and (c) the replacement of organic synthesized components with components derived from naturally occurring materials. Consequently, there is a need for novel enteric coating materials, compositions, and coating methods that are compatible with less stable pharmaceutical compositions, nutraceutical compositions, nutritional supplement compositions, and foodstuffs.
[0003] Sodium alginate is a sodium salt of alginic acid. Alginic acid is a naturally occurring linear copolymer with homopolymeric blocks of (1-4)-linked β-D-mannuronate (M) and its C-5 epimer α-L-guluronate (G) residues, respectively, covalently linked together in different sequences or blocks. Sodium alginate is soluble in water having a pH of 4 and greater. However, in acidic environments having pH values less than 4, e.g., in gastrointestinal systems, sodium alginate is converted into the insoluble alginic acid form. The physico-chemical properties of sodium alginate are well-known and have been exploited for many food and pharmaceutical applications as supplementary thickeners, coating materials and in the formulation of controlled-release compositions.
[0004] Grillo et al (U.S. Pat. No. 6,468,561) teach the use of polydextrose or a combination of polydextrose and other polymers to enhance adhesive quality and color stability of tablet-coating films. Grillo et al also provide formulations comprising 30 to 90% of polydextrose (w/w). Polydextrose is very soluble in water regardless of the pH values. Therefore, if such high concentrations of polydextrose were incorporated into enteric coating formulations, the coating functions and stabilities of the coated articles would be significantly impaired after their oral ingestion because polydextrose in the coating film will be rapidly dissolved. The consequence would be rapid breakdown and disintegration of the coating thereby resulting in premature release of the constituents of the coated articles into the stomach contents. Grillo et al also teach that overcoating their polydextrose coating with a secondary coating comprising 2% to 10% sodium alginate (w/w) may enhance the adhesiveness and color stability of their films.
[0005] Zhang et al (U.S. Pat. No. 6,251,430) teach a sustained-release drug dosage tablet formulation comprising a combination of: (a) a mixture of a water-insoluble polymer, a pH-dependent gelling polymer, a pH-independent gelling polymer, and (b) an active ingredient that requires a time-release profile. Zhang et al's formulation requires the three polymers, i.e., the water-insoluble polymer, the pH-dependent gelling polymer and the pH-independent gelling polymer, to be commingled in order to provide controlled-release of the intermixed active ingredient. Their water-insoluble polymer was exemplified by ethylcellulose and copolymers of acrylic and methacrylic acid esters (e.g., Eudragit®). Their pH-dependent gelling polymer was exemplified by alginates and sodium carboxymethylcellulose. Their pH-independent gelling polymer was exemplified by hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl ethylcellulose, carboxypolymethylene and the like. Zhang et al's tablet-compressing system is not applicable for soft-capsule systems because soft-capsules are formed by injection methods that require the active ingredients to be provided in a liquid or paste form.
[0006] Kim et al. (U.S. Pat. No. 6,365,148) teach the preparation of granulated microbial inocula by spray-coating bacteria in a fluidized bed granulator with a water-miscible coating composition thereby producing granules wherein each granule comprises a plurality of bacteria encased in the water-miscible composition. Kim et al teach that their water-miscible coating composition may comprise one or more of alginates, gums, wheat proteins, methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, polyvinylacetate phthalate and the like. Using Zhang et al's terminology, Kim et al's water-miscible coating comprises one or more of a pH-dependent gelling polymer and/or a pH-independent gelling polymer. Kim et al. further teach an optional second coating for application as an overcoat to their granulated microbial inocola, wherein the second coating is a controlled-release composition.
SUMMARY OF THE INVENTION
[0007] The exemplary embodiments of the present invention, are directed to suspendible enteric coating compositions configured for encasing orally ingested articles, and to methods for applying suspendible enteric coating compositions.
[0008] An exemplary embodiment of the present invention is directed to enteric coating compositions suspendible in water for encasing therewith orally ingestible articles exemplified by soft-gel capsules, hard-gel capsules, tablets, pellets and the like. The enteric coating compositions comprise at least a pH-dependent polymer, a pH-independent water insoluble polymer, and a plasticizer.
[0009] According to one aspect, the pH-dependent polymer is selected from a group containing alginates and alginic acids.
[0010] According to another aspect, the pH-independent water insoluble polymer is selected from the group containing ethylcellulose and ethylcellulose-containing compositions.
[0011] According to another aspect, the plasticizer is selected from the group containing triethyl citrate, glycerin, propylenglycol, triacetin, acetylated monoglycerides, dibutyl sebacate, polyethyleneglycols and middle chain triglycerides.
[0012] According to a further aspect, the enteric coating compositions may optionally comprise at least one of a flavorant and/or a colorant.
[0013] Another exemplary embodiment of the present invention is directed to a three-step method for coating mated two-piece hard-shell capsules. The first step generally comprises encasing a plurality of mated two-piece hard-shell capsules with a first suspension comprising (1) a mixture of at least a sugar and a microcrystalline cellulose, or (2) the combination of at least two of the materials selected from the group comprising modified starch, maltodextrin, dextrin, microcrystalline cellulose, carboxylmethylcellulose (CMC) and polysaccharides, and then drying said mated two-piece hard-shell capsules thereby providing a first coat thereon. The second step generally comprises encasing a plurality of the first-coated mated two-piece hard-shell capsules with a second suspension comprising a mixture of a film-forming polymer and a plasticizer, and then drying the mated two-piece hard-shell capsules to providing a second coat encasing the first coat. The film-forming polymer may be optionally mixed with a gel-forming agent and a plasticizer. The third step generally comprises encasing a plurality of the second-coated mated two-piece hard-shell capsules with a third suspension comprising a selected enteric coating, and then drying hard-shell capsules to provide a third coat encasing the first and second coats.
[0014] Another exemplary embodiment of the present invention is directed to a two-step method for coating mated two-piece hard-shell capsules. The first step generally comprises encasing a mated two-piece hard-shell capsules with a first suspension comprising a mixture of: (1) maltodextrin or polydextrose or both, (2) at least one ingredient selected from the group of modified starch, microcrystalline cellulose hydroxypropylene methylcellulose (HPMC), carboxylmethylcellulose (CMC) and polysaccharides. The first suspension may additionally comprise (3) a plasticizer selected from the group comprising triethyl citrate, glycerin, propylenglycol, triacetin, acetylated monoglycerides, dibutyl sebacate, polyethyleneglycols and middle chain triglycerides. After receiving a coating with the first suspension, the mated two-piece hard-shell capsules are then dried. The second step generally comprises encasing the first-coated mated two-piece hard-shell capsules with a second suspensions comprising a selected enteric coating, and then drying hard-shell capsules to provide a second coat encasing the first coat.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention is directed to enteric coating compositions suitable for orally ingestible articles exemplified by soft-gel capsules, hard-shell capsules, tablets and the like, and to methods for the application of the enteric coatings onto the orally ingestible articles.
EXAMPLE 1
Enteric Coating Compositions for Orally Ingestible Articles Exemplified by Soft-Gel Capsules, Hard-Shell Capsules, Tablets, Pellets and the Like
[0016] The present invention provides an exemplary enteric coating wherein the coating comprises three components. The first component is a pH-dependent polymer that is: (a) soluble in solutions having a pH value of 4, and (b) insoluble in solutions having a pH value less than 4. Suitable pH-dependent polymers are exemplified by sodium alginate, alginic acid and the like.
[0017] The second component is a pH-independent water insoluble polymer exemplified by ethylcellulose. Suitable commercially available ethylcelluloses are exemplified by Aquacoat® ACD that comprises 30% ethylcellulose (w/w) (supplied by FMC BioPolymer, 1735 Market Street, Philadelphia, Pa., 19103, USA) and Surelease® that comprises 25% ethylcellulose (supplied by Colorcon, Inc., 420 Moyer Blvd., West Point, Pa., 19486, USA).
[0018] The third component is a plasticizer exemplified by triethyl citrate, glycerin, propylenglycol, triacetin, acetylated monoglycerides, dibutyl sebacate, polyethyleneglycols, sorbitol, sorbitol special, middle chain triglycerides, and the combinations thereof.
[0019] An exemplary enteric coating composition according to the present invention, in a dry form, comprises: (a) about 10% to about 20% of a pH-dependent polymer, (b) about 40% to 75% of a pH-independent water insoluble polymer, and (c) about 7% to about 20% of a suitable plasticizer. The dry form of the enteric coating composition may be suspended in a suitable solvent exemplified by water, to product an enteric coating suspension which will comprise: (a) about 1% to about 2% of the suitable pH-dependent polymer, (b) about 5% to about 10% of the suitable pH-independent water insoluble polymer, and (c) about 0% to 3% of the suitable plasticizer.
[0020] It is within the scope of the present invention to incorporate suitable colorants into the enteric coating compositions described herein. Suitable colorants are exemplified by dyes, titanium dioxide, iron oxides, natural pigments, pearlescent pigments or other pigments approved by regulatory agencies such as the USDA, FDA and Health Canada among others.
[0021] It is also within the scope of the present invention to incorporate suitable flavorants into the enteric coating compositions described herein. Suitable flavorants are exemplified by those that are currently approved by regulatory agencies such as the USDA, FDA and Health Canada among others.
[0022] It should be noted that the enteric coating compositions disclosed here in are suitable for application onto soft-gel capsules, hard-gel capsules, tablets, pellets, granules and the like containing therein orally ingestible components.
EXAMPLE 2
An Exemplary Enteric Coating Composition
[0023]
[0000]
Component
Tradename
Weight
pH-dependent polymer
Sodium alginate
1.5
pH-independent water insoluble
Aquacoat ECD
28.3
polymer
(30% ethylcellulose)
Plasticizer
Triethyl citrate
2.1
Distilled water
water
68.1
[0024] The three components were mixed into the water at room temperature until fully suspended. The enteric coating suspension thus produced was coated onto pre-weighed softgels, allowed to dry, after which, the coated softgels were re-weighed. The coated softgels weighed about 9.5% more than the uncoated softgels. The coated softgels were then placed into a low pH gastric fluid solution (pH˜2) to determine coating stability in pH and enzyme conditions that approximate stomach acidity conditions, and then, were removed from the low pH solution and transferred to a neutral pH intestinal fluid solution (pH˜6) to determine coated softgel disintegration in pH conditions that approximate intestinal fluid conditions. No visible disintegration was detectable after 60 minutes in the low pH solution. However, the coating completely disintegrated within 60 minutes in the neutral pH solution.
EXAMPLE 3
Enteric Coating Compositions for Orally Ingestible Articles Exemplified by Soft-Gel Capsules, Hard-Shell Capsules, Tablets, Pellets and the Like
[0025] Orally ingestible hard-shell capsules are known to be particularly difficult to provide satisfactory enteric coatings onto. Hard-shell capsules generally comprise a bottom half-capsule matable to a top half-capsule. The bottom half-capsule is generally configured for receiving therein active ingredients to be encapsulate, while the top half-capsule is generally configured for continuously contacting the outer edges of the bottom half-capsule for containing therein the active ingredients. However, before the filled and mated hard capsule configuration can be coated with an enteric coating composition, the outer surfaces of the top half-capsule and bottom half-capsule have to be pre-coated with an elastic film-forming material. It is essential that the elastic film pre-coat is sufficiently thick to fill the juncture seam between the top half-capsule and the bottom half-capsule and provide a smooth continuous surface about and around the two mated half-capsules. Furthermore, it is desirable that the elastic film pre-coat is sufficiently flexible and pliable to absorb mechanical stresses and pressures during the coating processes while sealably containing the mated half-capsules. Consequently, the initial elastic film pre-coating step is time-consuming and critical for satisfactory subsequent application of the enteric coatings.
[0026] Another exemplary embodiment of the present invention is directed to a three-step method for application of suitable enteric coatings to hard-shell capsules that overcomes the current problems commonly encountered in providing suitable enteric coatings onto hard-shell capsules. The first step generally comprises applying to a mated hard-shell capsule, an encasing first coating of an aqueous solution comprising about 40% of solids including microcrystallinecellulose and sucrose exemplified by LustreSugar® (LustreSugar is a registered trademark of the FMC Corporation) so that the weight of the mated hard-shell capsule is increased by about 15% after the first coating has dried. It only took one and a half hour to coat because of high solid content solution. The first coating provides sealing and binding for holding the two half-capsules together. The second step generally comprises applying to the once-coated hard-shell capsule, a second encasing coating solution comprising a mixture of at least a film-forming polymer and/or a gel-forming agent. A suitable film-forming agent is exemplified by microcrystalline cellulose, hydroxypropylene methylcellulose (HPMC), hydroxypropylcellulose (HPC) or other available film-forming polymers. A suitable gel-forming agent is exemplified by polysaccharides, such as carrageenan and alginates, carboxymethylcellulose. An exemplary suitable commercial preparation containing a suitable firm-forming agent and a suitable gel-forming agent is LustreClear® (LustreClear is a registered trademark of the FMC Corporation). An exemplary second encasing solution is an aqueous suspension containing 10% LustreClear®. The second encasing suspension is applied to the once-coated hard-shell capsule so that the weight of the once-coated mated hard-shell capsule is increased by about 7 to 15% after the second coating has dried. The third step generally comprises applying to the twice-coated mated hard-shell capsule, an encasing coating of a suitable enteric coating. Suitable enteric coatings are exemplified by Aquacoat® CPD, Eudragit® methacrylic copolymers, Kollicoat® MAE, Surelease®, Acryl-EZE®, Opadry®, Sureteric®, and the like. It is within the scope of the present invention to optionally incorporate flavorants and/or colorants into one or more the coatings applied in the present 3-step coating method.
EXAMPLE 4
An Exemplary 3-Step Enteric Coating Method for Hard-Shell Capsule
[0027] The first step comprised preparation of an aqueous suspension comprising 40% Lustre Sugar® dissolved in distilled water. Mated hard-shell capsules were then first coated with the Lustre Sugar® solution and then dried. The dry weight of the first-coated mated hard-shell capsules increased by 15% of the weight of the mated hard-shell capsules.
[0028] The second step comprised preparation of an aqueous suspension comprising 10% LustreClear® LC-103, 5% of glycerin (plasticizer), and 85% distilled water. The dried first-coated mated hard-shell capsules were then encapsulatingly coated a second time using the LustreClear® suspension and then were dried. The dry weight of the second-coated mated hard-shell capsules increased by 15% over the weight of the first-coated mated hard-shell capsules.
[0029] The third step comprised preparation of an enteric coating suspension comprising 10% Kollicoat® MAE-100P, 5% propylene glycol, 85% distilled water. The dried second-coated mated hard-shell capsules were then encapsulatingly coated a third time using the Kollicoat® suspension and then were dried. The dry weight of the third-coated mated hard-shell capsules increased by 9% over the weight of the second-coated mated hard-shell capsules. After drying, the third-coated mated hard-shell capsules possessed a very smooth and seamless opaque outer coating.
EXAMPLE 5
An Exemplary 2-Step Enteric Coating Method for Hard-Shell Capsules
[0030] Another exemplary embodiment of the present invention is directed to a two-step method for application of suitable enteric coatings to hard-shell capsules that overcomes the current problems commonly encountered in providing suitable enteric coatings onto hard-shell capsules. The first step comprises applying to a mated hard-shell capsule, an encasing first coating of an aqueous solution comprising about 50% of solids including 20% polydextrose, 20% maltodextrin and 10% starch 1500. The first-coated mated hard-shell capsules increased by 13% of the weight of the mated hard-shell capsules. The dried first-coated mated hard-shell capsules, which gave a transparent appearance, were then encapsulatingly coated a second time using the Kollicoat® suspension and then were dried. The dry weight of the second-coated mated hard-shell capsules increased by 9% over the weight of the second-coated mated hard-shell capsules. After drying, the second-coated mated hard-shell capsules possessed a transparent appearance. The coated softgels were then placed into a low pH gastric fluid solution (pH˜2) to determine coating stability in pH and enzyme conditions that approximate stomach acidity conditions, and then, were removed from the low pH solution and transferred to a neutral pH intestinal fluid solution (pH˜6) to determine coated softgel disintegration in pH conditions that approximate intestinal fluid conditions. No visible change in shape was detectable after 60 minutes in the low pH solution. However, the coating completely disintegrated within 60 minutes in the neutral pH solution.
EXAMPLE 6
An Exemplary 2-Step Enteric Coating Method for Hard-Shell Capsules
[0031] The first step comprises applying to a mated hard-shell capsule, an encasing first coating of an aqueous solution comprising about 47% of solids including 18% polydextrose, 18% maltodextrin, 9% instant pure-cote B793 (starch) and 2% glycerin. The first-coated mated hard-shell capsules increased by 20% of the weight of the mated hard-shell capsules. The dried first-coated mated hard-shell capsules were then encapsulatingly coated a second time using the Kollicoat® suspension and then were dried. The dry weight of the second-coated mated hard-shell capsules increased by 9% over the weight of the second-coated mated hard-shell capsules. After drying, the second-coated mated hard-shell capsules possessed a transparent appearance. The coated softgels were then placed into a low pH gastric fluid solution (pH˜2) to determine coating stability in pH and enzyme conditions that approximate stomach acidity conditions, and then, were removed from the low pH solution and transferred to a neutral pH intestinal fluid solution (pH˜6) to determine coated softgel disintegration in pH conditions that approximate intestinal fluid conditions. No visible change in shape was detectable after 60 minutes in the low pH solution. However, the coating completely disintegrated within 60 minutes in the neutral pH solution.
[0032] While this invention has been described with respect to the exemplary embodiments, it is to be understood that various alterations and modifications can be made to the enteric coating compositions, and to methods of applying enteric coating compositions can be made within the scope of this invention, which are limited only by the scope of the appended claims.
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A suspendible enteric coating composition for encasing orally ingestible articles wherein the enteric coating composition comprises a pH-dependent polymer selected from a group containing alginates and alginic acids, a pH-independent water insoluble polymer selected from the group comprising ethylcellulose and ethylcellulose-containing compositions, and a plasticizer selected from the group containing triethyl citrate, glycerin, propylene glycol, triacetin, acetylated monoglycerides, dibutyl sebacate, polyethylene glycols, sorbitals, middle chain triglycerides and combinations thereof. A three step method for providing a stable outer enteric coating on an ingestable item comprising a first step of encasing the item with a suspension comprising a mixture of at least a sugar and a microcrystalline cellulose, a second step of then encasing the item with a suspension comprising a mixture of a film-forming polymer and a plasticizer, and a third step of finally encasing the item with the enteric coating composition.
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This is a division of application Ser. No. 698,019, filed Feb. 4, 1985, U.S. Pat. No. 4,659,815.
BACKGROUND OF THE INVENTION
The present invention relates to novel chromogenic crown ethers and to the use of the ethers as reagents for the selective extraction and colorimetric determination of lithium. The compounds of the invention have the structural formula: ##STR1## wherein X and Y are, respectively, (i) OH and NH + ; (ii) O - and N, or (iii) O - and NH + . When X is OH and Y is NH + , the compound is systematically named, 1-(2-hydroxy-5-nitrobenzyl)1-hydro-1-aza-4,7,10-trioxacyclododecane; when X is 0 + - and Y is N, 1-(2-oxy-5-nitrobenzyl)-1-aza-4,7,10-trioxacyclodecane; and, when X is - and Y is NH + , 1-(2-oxy-5-nitrobenzyl)-1-hydro-1-aza-4,7,10-trioxacyclododecane. All three of these compounds are, generically, chromogenic aza-12-crown-4 ethers.
Selective reagents which permit the isolation of a particular ion from a complex matrix or mixture of ions are of interest to those in the chemical or bio-chemical analytical fields. When the matrix in question includes two or more cations of the Group I metals, it is often difficult to selectively isolate one of the Group I cations from the mixture without interference from other cations in the system. With respect to biological systems, such as blood serum, which contains a relatively large amount of sodium ion, a reagent having the ability to selectively (and quantitatively) extract lithium ion in the presence of sodium ion is of interest for bio-chemical assays.
The ability of crown ethers to selectively extract alkali and alkaline earth metal ions has been recognized in the art [Pedersen, C. J., J.Am.Chem.Soc. 1967, 89, 7017]. Nonetheless, there has been little successful work in utilizing these compounds in analytical determinations until quite recently, e.g., U.S. Pat. No. 4,436,923 to Pacey and Bubnis, which describes a crown ether reagent which can be used for the spectrophotometric determination of potassium ion in the presence of sodium ion.
Of particular interest to the background of the present invention is the crown ether N-(2-hydroxy-5-nitrobenzyl)-aza-15-crown-5 ##STR2## which was reported to be a selective extractant for lithium ion. [Nakamura, H., Sakka, H., Takagi, M. and Ueno, K., Chem.Lett., 1981, 1305]. Although this compound exhibited good extraction efficiency for lithium ion (-logK) LiL ex =9.15), the extraction efficiency of the reagent for sodium ion was of the same order of magnitude (-logK NaL ex =9.76). Thus the compound exhibited relatively poor selectivity in that it displayed only slightly more affinity for the lithium ion.
Another compound which is of interest to the chromogenic aza-12-crown-4 compounds of the present invention is the cryptand [2,1,1]. ##STR3## which was reported to extract lithium ions more selectively and more efficiently than the reagent of Nakamura et al. [Wu, Y. and Pacey, G., American Chemical Society 15th Central Regional Meeting, Miami University, Ohio, 1983, No. 18 (May 23-25, 1983)]. However, not only is the Wu et al cryptand difficult to synthesize, but the cryptand also requires an ion pairing agent, resazurin, in order to exhibit sensitivity to lithium. That is, the [2,1,1]cryptand itself is not sensitive to lithium ions.
SUMMARY OF THE PRESENT INVENTION
The present invention provides novel chromogenic crown ethers, viz, (i) 1-(2-hydroxy-5-nitrobenzyl)-1-hydro-1-aza-4,7,10-trioxacyclododecane; (ii) 1-(2-oxy-5-nitrobenzyl)1-aza-4,7,10-trioxacyclododecane; and, (iii) 1-(2-oxy-5-nitrobenzyl)-1-hydro-1-aza-4,7,10-trioxacyclododecane. It has been found that the presence of these structures is pH dependent. If the pH is low (less than 5), structure i will predominate. At higher pH's (greater than 11), compound ii represents the reagent structure. At a pH of approximately 8, a structure such as iii will predominate.
Reagents formed from these aza-12-crown-4 compounds exhibit affinity for lithium ion, and are substantially unreactive to potassium, rubidium, cesium and ammonium ions. Although the aza-12-crown-4 reagents exhibit some sensitivity to sodium, the affinity of the reagents for lithium ion is over two orders of magnitude (100 times) greater than their affinity for sodium ion.
Useful aqueous reagent compositions will result when the concentration of the aza-12-crown-4 ether is in the range 1×10 -4 M to 1×10 -2 M. The 10 -4 M concentration approximates the detection limit of the crown ether-lithium compound extracted to organic phase. On the other hand, use of concentrations in excess of 10 -2 M does not result in increased sensitivity with accuracy.
A base is required in the reagent system to ensure optimum properties. Both NaOH and KOH are suitable bases, but potassium hydroxide is generally preferred due to interference effects of the sodium ion on the absorbance during spectrophotometric analysis. The optimum concentration of hydroxide base is approximately 1×10 -2 M to 1×10 -1 M, although lower concentrations can be employed with some sacrifice in sensitivity.
The basic, aqueous reagent composition can be added to aqueous samples containing lithium ion resulting in the formation of a lithium ion/crown ether complex. Subsequent extraction of the sample with an organic solvent will cause the lithium ion/crown ether complex to pass into the organic phase. The absorbance of the organic phase can be measured against a reagent blank utilizing conventional spectrophotometric techniques. Although a number of organic solvents can be employed, it has been found that chloroform is preferred. When a reagent composition of the invention was added to aqueous solutions containing Na + and Li + in the weight ratio 30:1 and the solution was extracted with organic solvent, absorbance increased 8% when compared to a control containing Li + , alone, notwithstanding the presence of the large excess of sodium ion. Thus, aza-12-crown-4 compounds exhibit a high degree of selectivity for lithium in matrices which contain both lithium ion and sodium ion. The aza-12-crown-4 reagents can be synthesized as follows:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the ultraviolet-visible spectra of an aqueous solution containing a chromogenic aza-12-crown-4 reagent of the present invention, hydrochloric acid and cesium chloride while undergoing titration with potassium hydroxide. The procedure utilized is set forth in Example 6.
FIG. 2 illustrates the acid dissociation constants K 1 and K 2 and the complex formation constant K ML for the aza-12-crown-4 reagent of the present invention.
FIG. 3 illustrates the ultraviolet visible spectra of chloroform layers utilized in extracting aqueous basic solutions of lithium chloride and aza-12-crown-4 reagent at nine different levels of lithium ion in accordance with the procedure of Example 7.
FIG. 4 is the ultraviolet visible spectra of chloroform layers utilized in extracting aqueous basic solutions of lithium ion in the presence of sodium ion and employing a reagent compound of the present invention in accordance with the procedure of Example 9.
FIG. 5 shows the plots of data obtained for the determination of the extraction constant, K ML ex .
DETAILED DESCRIPTION
The preparation of the reagent aza-12-crown-4 compounds and their use as a reagent for the determination of lithium ion are illustrated in the following examples:
EXAMPLE 1--Preparation of 3-benzyl-1,5-diol-3-azapentane (1).
Benzyl chloride (158g, 1.25 mol) was stirred in a water-cooled reaction vessel while diethanolamine (126g. 1.2 mol) was gradually added. The temperature of the reaction mixture was kept below 70° C. until it became homogeneous and heat release stopped. The mixture was then kept at 70° C. for more than 1 hour, and, after cooling, dissolved into 200 ml of 1 M hydrochloric acid. The aqueous solution was extracted four times with 100 ml chloroform washes. To the aqueous solution, 300 ml of 5 M NaOH was added with water cooling in order to isolate the oily product. The oil layer was mixed with 300 ml of chloroform, washed with 100 ml of water and dried over anhydrous magnesium sulphate. The chloroform solution was evaporated to dryness. The pure compound (1) was obtained as light-yellow oil. Yield 67%; 1 HNMR (CDCl 3 ): δ 2.50-2.68 (t, 4H, N--CH 2 ), ˜3.2 (br, 2H, OH), 3.41-3.60 (t, 4H,O--CH 2 ; s(3.60), 2H, Ar--CH2), 7.10 (s, 5H, Ar--H).
EXAMPLE 2--Preparation of 1,5-dichloro-3-oxapentane (2).
Utilizing a procedure similar to that described in the literature [Pedersen, C.J., J.Am.Chem.Soc., 1967, 89, 7017], diethylene glycol was chlorinated with thionyl chloride in the presence of pyridine in benzene. The product was purified by vacuum distillation (0.7 Torr, 40°-0.25 Torr, 35° C.). Yield 69%; 1 HNMR (CDCL 3 ): δ3.4-3.9 (m, 8H).
EXAMPLE 3--Preparation of 1-benzyl-1-aza-4,7,10-trioxacyclododecane (3).
The cyclization of the diol(1) prepared in Example 1 with the dichloride(2) prepared in Example 2 was performed under the template effect of Li + ions in a highly diluted solution in accordance with a procedure suggested in the literature [Miyazaki, T., Yanagida, S., Itoh, A., Okahara, M., Bull. Chem. Soc. Jpn., 1982, 55, 2005]. A 1.6 liter portion of t-butylalcohol was refluxed together with lithium metal (6.2g, 0.9 mol) with stirring for two hours. Diol(1) (58.5 g, 0.3 mol) dissolved in 50 ml of t-butylalcohol was added to the reaction mixture and refluxing was continued for an additional 2 hours. Dichloride (2) (42.9 g, 0.3 mol) and lithium bromide (26 g, 0.3 mol) were added to the reaction vessel and the heterogeneous mixture was refluxed for 10 days to ensure reaction. The alcohol solvent was evaporated by using a rotary evaporator. Water (250 ml) was added to the residue to dissolve the inorganic salts and isolate a reddish-brown oil. The oil layer was mixed with 60 ml of chloroform, washed three times with 1M sodium hydroxide (30 ml), and slowly mixed with 100 ml of 5M hydrochloric acid while maintaining room temperature by water cooling. Thereafter, the aqueous layer was washed three times with chloroform (50 ml) and 80 ml of 4M sodium hydroxide was added slowly to a cooled vessel containing the aqueous solution, to isolate the oil. The cooled mixture was extracted with chloroform, the organic layer was dried over anhydrous magnesium sulphate, and evaporated to dryness under vacuum. The pure compound (3) was obtained by vacuum distillation (0.027 Torr, 112 °C. -0.04 Torr, 123° C.). Yield 63%; 1 HNMR (CDCl 3 ): δ 2.5-2.75 (m, 4H, N--CH 2 ), 3.35-3.65 (m, 14H, O--CH 2 , Ar--CH 2 ), 7.10(s, 5H, ArH).
EXAMPLE 4--Preparation of 1-aza-4,7,10-trioxacyclododecane (4).
A quantity of the 1-benzyl-1-aza-4,7,10-trioxacyclododecane compound (3) prepared in Example 3 (45.1 g, 0.17 mol), ethanol (7 g), and 10% palladium on carbon (0.5 g) were shaken in hydrogen atmosphere at more than 50 psi (1 psi= 6.9×10 3 Pa=0.07 kg cm -2 ). Hydrogen gas was recharged several times into the reaction chamber to keep the pressure elevated. Shaking was continued until the pressure lowering stopped (4 days). After the palladium carbon was filtered, the solvent was evaporated. The pure compound (4) was sublimed from the residue with gentle heating using a water bath (75°-77° C.; crude material melted at this temperature). The sublimate was white needles and was hygroscopic. Yield 60%; 1 HNMR (D 2 O): δ 2.53-2.70 (t, 4H, N--CH 2 ), 3.5-3.75 (m, 12H, O--CH 2 ), no signal at 7.1 (Ar--H of benzyl group, possible contaminant).
EXAMPLE 5--Preparation of 1-(2-oxy-5-nitrobenzyl)-1-hydro1-aza-4,7,10-Trioxacyclododecane (5).
The aza-crown 4 prepared in Example 4 (1.05 g, 0.0060 mol), freshly distilled tetrahydrofuran (THF; 50 ml), and potassium hydroxide pellets (0.8 g, 0.014 mol) were placed in a flask. A solution of 2-hydroxy-5-nitrobenzyl bromide (1.40 g, 0.0060 mol) dissolved in THF was added with vigorous stirring, which was continued overnight (14 hr). Examination of the reaction flasks revealed that bright yellow and white powders had been produced, and the potassium hydroxide pellets had been completely consumed. After evaporation of the solvent, the residue was dissolved into water (20 ml), and 6M hydrochloric acid (˜45 drops) was added until the solution turned colorless or pale yellow (di- or mono-protonated form respectively). The solution was extracted with chloroform while undergoing drop-wise titration with 5M potassium hydroxide. The effect of the titration was to convert the diprotonated compound to the monoprotonated dipolar ion (5), which was easily extracted to chloroform. The titration and shaking for extraction were continued until no increase in color intensity in the aqueous layer was observed during the titration. The aqueous layer was twice extracted with chloroform (20 cc). All the chloroform solutions were combined, washed with water (20 ml) four times, filtered with dry filter paper, and evaporated to dryness. In order to remove water-insoluble impurities, the residue was dissolved into water, filtered and evaporated to dryness. The pure compound (5) was obtained by the dissolution of the residue into chloroform and evaporating it to dryness in vaco with heating (80°-90° C.). The compound (5) (bright yellow) crystallized slowly from a glassy solid. Yield: 93%; m.p.: 98.5° C. 1 HNMR (CDCl 3 ): δ 2.6-2.8 (m, 4H, N--CH 2 ), 3.5-3.8 (m, 14H, O--CH 2 , Ar--CH 2 ), 6.62-6.77 (d, 1H, Ar--H) 7.72-8.02 (m, 2 H, Ar--H). Anal. Found: C, 55.30%; H, 7.04%; N, 8.52%. Calcd for C 15 H 22 O 6 N 2 : C, 55.19%; H, 6.81%; N, 8.58%.
EXAMPLE 6--Determination of Acid Dissociation Constants, K 1 and K 2 .
A 50 ml aqueous solution containing the crown reagent of Example 5 (8.70×10 -5 M), hydrochloric acid (6×10 -4 M), and cesium chloride (0.1 M) was titrated with potassium hydroxide [0.1 M (below pH12), and 1 M (above pH12)], using a Metrohm automatic titrator, Dosimat E535 equipped with Potentiograph E536. The titration was interrupted in every 0.3-1.5 pH increase for the measurement of the absorption spectrum of the solution. A 3-4 ml portion of the solution was taken to a cuvette, the spectrum was recorded on a Hewlett-Packard 8450A spectrometer, and the solution was returned to the titration vessel using a pipet. The magnitude of the spectrum was corrected in order to adjust for dilution upon titration, and corrected results shown in FIG. 1.
Equilibria for the chromogenic aza-12-crown-4 reagent in an aqueous solution are shown in FIG. 2 and as follows. ##EQU1## where K 1 and K 2 denote the acid dissociation constants, and K ML a complex formation constant. By assuming no significant complex-formation, an absorbance A at any wavelength and the total concentration of the reagent [HL] t are written as
A=ε.sub.HLH.spsb.+ [HLH.sup.+ ]+ε.sub.HL [HL]+εL.sub.L.spsb.- [L.sup.- ] (4)
[HL].sub.t =[HLH.sup. 30 ]+[HL]+[L.sup.- ] (5)
where ε's are molar absorption coefficients. Equations (1) and (2) can be rewritten using Equations (4) and (5) as: ##EQU2## assuming [HL] t >>[L - ]for K 1 and [HL] t >>[HLH + ]for K 2 . The fact that FIG. 1 exhibits two distinct isosbestic points (342.8 nm and 401.4 nm) depending on pH confirms that [L - ]or [HLH + ]can be neglected as compared with [HL] t in a certain pH region; thus [HL] t >>[L - ]at pH ≦6.6 (Eq. (6) is valid), and [HL] t >>[HLH + ]at pH ≧9.7 (Eq. (7) is valid).
FIG. 1 also shows that, at 401.4 nm and at pH ≧6.6, the absorbance approaching to the isosbestic point reflects the decay of HLH + and the growth of HL, so that these absorbance data can be used for the evaluation of -logK 1 using Eq. (6). At 342.8 nm and at pH ≧9.7, the absorbance deviating from the isosbestic point reflects the decay of HL and the growth of L-, so that these absorbance data can be used for the evaluation of -logK 2 using Eq. (7).
In Eq. (6) and (7), since [H + ]is known experimentally, and since ε HL [HL] t can be obtained as the average value of absorbances on each isosbestic point, unknown parameters are now only ε HLH + [HL] t and ε L [HL] t , which can be adjusted to give constant values for -logK 1 and -logK 2 , respectively, by applying the observed absorbance sets to the equations.
Table 1 lists the observed values for K 1 and K 2 for the chromogenic aza-12-crown-4 reagent of the present invention as well as the reported values for the prior art crown ether, N-(2-hydroxy-5-nitrobenzyl)-aza-15-crown-5 [Nakamura et al, Chem.Lett., 1981, 1305]. The value of -logK 1 for the aza-12-crown-4 reagent agrees reasonably with that reported for the aza-15-crown-5 reagent. However, the higher value of -logK 2 for the aza-12-crown-4 compound indicates that the proton of the reagent of the present invention is more tightly bound with the nitrogen atom and that complex formation is enhanced at a pH higher than 10.3.
TABLE 1__________________________________________________________________________ACID DISSOCIATION CONSTANTS (K.sub.1 and K.sub.2)AND EXTRACTION CONSTANT (K.sup.ex .sub.ML) -log K.sup.ex .sub.LiL -log K.sup.ex .sub.NaL -log K.sub.1 -log K.sub.2 0.1M KOH 0.05M KOH 0.1M KOH 0.05M KOH__________________________________________________________________________aza-12-crown-4 5.77.sup.a 10.31.sup.a 10.18.sup.c 10.23.sup.c 12.50.sup.c 12.49.sup.c(present invention)aza-15-crown-5 5.79.sup.b 9.69.sup.b 9.15.sup.d 9.76.sup.d(prior art)__________________________________________________________________________ .sup.a μ = 0.1 (CsCl) .sup.b μ = 0.1 (CH.sub.3).sub.4 NCl) .sup.c Solvent, chloroform .sup.d Solvent, 1,2dichloroethane; pH, not specified
EXAMPLE 7--Solvent extraction of lithium-ion containing solutions
Nine 10 ml volumetric flasks were prepared as follows: 1 ml of 1 M KOH and 2 ml of 3.34×10 -3 M aza-12-crown-4 reagent were added to each of the flasks; a measured amount of a 10 -3 M LiCl solution was added to eight of the flasks in 0.5 ml increments, (i.e., 0.5 ml, 1 ml, 1.5 ml, 2 ml, 2.5 ml, 3 ml, 3.5 ml, 4 ml); thereafter, sufficient water was added to the nine flasks to make the total volume of each flask 10 ml. Five ml aliquots of each of the volumetric flasks were transferred into a series of nine 50 ml round-bottomed flasks, forming aqueous solutions containing a constant amount of both the aza-12-crown-4 reagent (6.7×10 -4 M=0.22 μg ml -1 ) and potassium hydroxide (10 -1 M), and a varying amount of lithium chloride -- eight samples ranging from [LiCl]aq=5×10 -5 M through 4×10 -4 M (0.35 μg ml -1 through 2.8 μg ml -1 ), plus a non-lithium-containing blank. The concentration of hydroxide ion (1×10 -1 M) in each of the samples (including the flask containing no lithium chloride) was chosen based on the previously-determined pK 2 value (10.31). Five ml of chloroform was added to each of the round-bottomed flasks, each of the flasks was shaken for 20 minutes and, after shaking, left standing for more than 10 minutes at room temperature (20°± C. 2° C.). Absorbance of the organic layer was measured at 400 nm using a Hewlett-Packard 8450A UV/VIS spectrophotometer. Spectral data are illustrated in FIG. 3.
A calibration curve was obtained whose linear portion is from 0.3 μg ml -1 through 2 μg ml -1 , which can be expressed as:
C.sub.Li =3.00A±0.05
where C Li and A denote the concentration of lithium in μg ml -1 and the net absorbance (path length: 1 cm) at 400 nm, respectively. The error was calculated from the mean value of the standard devations of triplicate samples over the linear range. The error seemed to be mainly caused by the instability of the absorbance after the separation of the organic layer. The stability was improved, with slight loss of sensitivity and slight increase in interference, by the addition of a small amount of t-butyl alcohol (2% by vol.) to the chloroform, while the blank absorbance increased by a factor of 1.6.
EXAMPLE 8--Determination of extraction constant, K ML ex .
Extraction equilibria are illustrated in FIG. 2 and in the following equation: ##EQU3## where [M + ] t denotes a total alkali metal concentration. By assuming [L - a ]>>[HL a ]+[ML a ], and [M + ] t >>[HL] t ,
[HL].sub.t =[HL.sub.o ]+[ML.sub.o ]+[L.sup.-.sub.a ] (12)
[M.sup.+].sub.t =[M.sup.+.sub.a ] (13)
Combining Eq. (8), (11), (12), and (13) gives ##EQU4## where Δε=εML o -εHL o , and E° denotes the E value in the absence of the metal ion in the system (E°=.sup.ε HL o ). Eq. (14) shows that the plot of 1/(E°--E°) against 1/[M] t gives a straight line and that K ML ex is calculated from the slope, the intercept, and the pH value. The absorbance at the isosbestic point 401.4 nm shown in FIG. 1 gives ε L .spsb.-.sbsb.a, so that the values of E and E o , which are necessary for the plot, can be obtained experimentally.
Determination of the partition equilibrium system was made in a manner similar to that employed in Example 7. The concentrations [HL] t , [M + ] t , and [OH - ] were 5.35×10 -5 M, 4×10 -3 M-2 M (as chloride), and 10 -2 M-10 -1 M (as potassium hydroxide), respectively. Chloroform was used as the organic medium.
In order to confirm the important assumption [L a - ]>>[HL a ]+[ML a ], Eq.(11) (the left equation) was used for the evaluation of E instead of Eq.(15), which was derived from Eq.(11) under the assumption, and the obtained extraction constants compared with those obtained using Eq.(15). When Eq.(11) was applied, the species HL o and ML o in the organic layer were extracted into 0.1M hydrochloric acid as HLH + , and the concentration of HLH+was determined spectrophotometrically and equated to [HL o ]+[ML o ]in Eq.(11). The extraction constants obtained in this way are
-log K.sub.LiL.sup.ex =10.25, and -log K.sub.NaL.sup.ex =12.47
which agreed well with those obtained with the assumption (Table 1).
EXAMPLE 9--Effect of sodium ion
The effect of sodium ion in the system was determined in a procedure similar to that used in Example 7. A series of six round-bottomed flasks containing 5 ml of chloroform, and 5 ml of an aqueous solution containing aza-12-crown-4 reagent (6.7×10 -4 M), lithium chloride (1×10 -4 =0.694 μg ml -1 ), and a variable amount of sodium chloride [sodium chloride was added to five of these flasks in 0.001M increments whereby the [NaCl]aq =1×10 -3 M to 5×10 -3 M (23 μg ml -1 through 115 μg ml -1 ); one flask served as a sodium-free blank]. Absorbance of the organic layer was measured on a spectrophotomer. The results are illustrated in FIG. 4.
An analysis of FIG. 4 at 400 nm reveals that the sodium ion interference was linear in the whole range, and that the presence of a 30-fold excess of sodium ions to lithium ions resulted in only an 8% increase in absorbance.
FIG. 5 shows the plots of data obtained for the determination of K ML ex according to Eq. (14). The plot exhibits good straight lines for the lithium and sodium ion systems, respectively. Table 1 shows the -logK ML ex values obtained from the plots in FIG. 5 and from similar plots, together with that reported for the aza-15-crown-5 compound of the prior art. The -log K LiL ex is not significantly dependent on the hydroxide concentration employed.
When compared with the prior art aza-15-crown-5 compound, the value of K LiL ex for the aza-12-crown-4 reagent is smaller by a factor of ten. However, the ratio of K LiL ex to K NaL ex for the crown-4 is much greater than the aza-15-crown5. Thus, the extraction efficienty of aza-12-crown-4 might be lower than that of aza-15-crown-5, but its selectivity for lithium ions in the presence of sodium ions is much higher.
EXAMPLE 10--Effect of organic solvents and bases
Three solvents--chloroform, 1,2-dichloroethane and methylene chloride--were compared using potassium hydroxide and sodium hydroxide as bases. At 0.01 M hydroxide, no significant sensitivity and interference differences were observed between either the cations of the bases or between the organic solvents. At 0.1M hydroxide, however, large differences were observed both between the cations and between the organic solvents. Potassium hydroxide gave higher sensitivity in both chloroform and methylene chloride than sodium hydroxide, but not in 1,2-dichloroethane. Methylene chloride exhibited the highest sensitivity when used with potassium hydroxide, but was subject to increased interference by sodium ions. The combination of methylene chloride and sodium hydroxide allowed most of the reagent to pass into the organic layer and, as a result, the absorbance could not be measured. The results show that the optimum combination of high sensitivity, low interference, and low blank absorption was achieved by a system employing 0.1M potassium hydroxide and chloroform. The best stability of the absorbance after the separation of organic layer from the equilibrium system was also observed for this system.
Various other organic solvents were tested as organic media with a 0.01 M potassium hydroxide. Nitromethane and 10% nitromethane in chloroform extracted most of the reagent species into the organic phase, so that no response of the reagent to lithium and sodium ion was observed. Methyisobutyl-ketone showed only slight extraction of the metal complex. No extraction occurred into benzene, carbon tetrachloride, chlorobenzene, and trichlorethylene when these solvents were employed.
Although triethylamine (1M in CHCl 3 ) was examined as an organic base, the response to lithium ions was smaller and the response to sodium ions was larger than the preferred KOH inorganic base. A combination of the amine (1M in CHCl 3 ) and sodium hydroxide (0.1M) as base gave an intermediate response to lithium ions, and the response was not stable.
Example 11--Determination of lithium ion content in blood and urine samples.
Samples of human blood serum and urine were analyzed for lithium ion content utilizing a chromogenic aza-12-crown4 ether reagent. The procedure employed was essentially the same for both the blood serum and urine specimens except that larger dilutions were employed with the urine samples due to the higher concentration of lithium ion in urine. Because proteins react with the reagent to form emulsions, the blood serum and urine samples were heat-denatured prior to analysis.
Three specimens of blood serum and four specimens of urine, all of whose lithium ion content had been previously determined, were analyzed utilizing 1-(2-oxy-5-nitrobenzyl)1-hydro-1-aza-4,7,10 trioxacyclododecane reagent. Triplicate 3.0 ml samples of blood serum (nine samples) were transferred to labeled centrifuge tubes and 3 ml of water added to each sample. A similar procedure was followed with respect to the urine specimens, except that 1.0 ml samples were employed and each of the twelve urine samples was diluted with 11 ml of water. The samples were mixed, heated in a boiling water bath for 15 minutes, and centrifuged for 10 minutes. A 2.0 ml aliquot of each of the twenty-one sample solutions was transferred to a series of stoppered centrifuge tubes, and 2.0 ml of the crown ether solution (b 1×10 -3 M), 1 ml of KOH solution (1M) and 5 ml of water was added thereto (total volume=10 ml). Each of the samples was thoroughly mixed to ensure homogeneity, 10 ml of chloroform added to each tube, and the samples were shaken for 10 minutes. After phase separation, the absorbance of the organic phase of each of the samples was measured at 400 nm against a reagent blank. The results are set forth in Table 2.
TABLE 2______________________________________Determination of Lithium ion in Blood Serum or UrineUsing Chromogenic Aza-12-Crown-4.Blood Serum* Urine*Known Found Known Found______________________________________3.5 3.4 10.5 10.47.0 6.8 14.0 14.010.5 10.3 21.0 20.8 42.0 40.7______________________________________ *Triplicate Determination. Results are reported as parts per million.
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Chromogenic aza-12-crown-4 ethers which can be used for the spectrophotometric determination of lithium ion in aqueous solutions are disclosed. The compounds of the invention are particularly useful for the analysis of Li + in the presence of Na + , a situation common in biological and geological systems. The compounds [e.g., 1-(2-oxy-5-nitrobenzyl)-1-hydro-1-aza-4,7,10-trioxacyclododecane], their methods of manufacture, and methods of utilizing the compounds for the analysis of lithium are disclosed.
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FIELD OF THE INVENTION
[0001] The invention relates to a method of melting together the axial ends of bunched fibers of thermoplastic material, wherein the fiber ends are brought into contact with a heated surface of a stamp. The invention relates further to a device for attaching tufts of bristles for use in brushes to carrier plates of thermoplastic material. The carrier plates with the tufts of bristles attached thereto are incorporated in brush bodies, in particular for the fabrication of tooth brushes.
BACKGROUND OF THE INVENTION
[0002] Several methods are known for the fabrication of brushes. In principle, brush bodies, having an array of holes corresponding to the desired array of bristles, can be provided. The tufts of bristles are then inserted into the holes of the brush body and anchored therein. The anchorage of the tufts of bristles in the brush body by means of anchor platelets or loops requires, however, highly performant and hence expensive machines.
[0003] According to an alternative fabrication method for brushes, the tufts of bristles are attached to a carrier plate that then is built into a brush body. The carrier plate can be joined to the brush body by injection-moulding around it or by welding. The carrier plate will be provided with holes according to the desired hole pattern, the utilization ends of the tufts of bristles projecting out of one surface of the carrier plate, and the axial ends of the tufts of bristles to be anchored in the brush protruding slightly out of the opposite side. A heated stamp is pressed against those ends of the tufts of bristles that are to be anchored in the brush body, melting together the ends of the tufts of bristles and possibly deforming them into knobs. During the subsequent separation of the stamp from the melted fiber ends, sticky threads and smearing of the viscous melted synthetic material may occur. Since, furthermore, the ends of the bristles as well as the carrier plate are heated, it is difficult on the one hand to effect the deformation of the bristles necessary for a perfect anchoring, and to prevent on the other hand an unwanted deformation of the carrier plate, all the more since the carrier plate and the bristles usually are made of different synthetic materials.
BRIEF SUMMARY OF THE INVENTION
[0004] The invention provides a method of melting together the axial ends of bunched fibers of thermoplastic material, wherein the fiber ends are brought into contact with the heated surface of a stamp. According to the invention, the body of the stamp is heated by passing a controlled electric current through it, enabling extremely rapid and precisely controllable temperature changes of the stamp.
[0005] In a first variant of the invention, the fiber ends are brought into contact with a heated surface of a stamp, which then is cooled abruptly. Only after cooling of the surface has occured, the fiber ends are separated from it. In this way, the melted fiber ends can be removed cleanly from the heated surface and show an overall shape that is determined by the geometry of the surface. In this variant the application of a non-stick coating is advantageous.
[0006] Like in the first variant, in a second variant according to the invention the fiber ends are first brought into contact with a surface heated to a first temperature. The surface is then separated from the fiber ends while maintaining, however, the temperature of the surface. After that, the surface is heated up to a second, higher temperature in order to vaporize any remainder of the fiber material adhering to the surface. In a final step according to the method, the surface is cooled again to the first temperature. In this variant, the adherence properties of the heated surface with respect to the heated fiber material are uncritical, a non-stick coating being hence unnecessary.
[0007] Both variants of the invention are especially suited for the fabrication of arrays of bristles to fabricate brushes. Fibers for the fabrication of brushes mostly consist of a thermoplastic material like polyamide (“nylon”). This material can be deformed easily with the inventive method.
[0008] The invention further provides a device for attaching tufts of bristles to carrier plates in order to manufacture brushes, enabling a controllable and well reproducible operation of the stamp upon the ends of the bristles, assuring the desired deformation of the ends of the bristles without any unwanted deformation of the carrier plate. In the device according to the invention, the stamp is heated by an electric current and can be cooled by a flowing cooling agent. The stamp can be heated rapidly and in a specific way by an electric current, especially if, according to the preferred embodiment, it has a low heat capacity, so that it quickly can be cycled through different temperature phases, including cooling by the cooling agent. Since the ends of the bristles are heated only a very short time and instantanously cooled again afterwards, a smearing of the heated bristle material on the carrier plate is avoided. By the same token, the stamp may alternatively be heated to a second, higher temperature after having been withdrawn from the fiber ends in order to vaporize any remainder of the fiber material adhering to the surface. The carrier plate itself is warmed up only slightly since the stamp is heated only for a short time to the temperature needed to melt together the ends of the bristles, and is removed or cooled instantaneously thereafter. Controlling the electric current, particularly via pulse width modulation, allows a good control of the intensity and the duration of the heating process.
[0009] Preferably, the stamp comprises a body of electrically conducting material, on which two electrical high-current terminals in the shape of bent-off contact shoes are formed. The body of the stamp has a thin-walled stamp plate that may be strengthened by an angled bordering strip. Suitable materials for the manufacturing of the stamp are metals, having on the one hand sufficent mechanical strength in order to assure the desired low heat capacity needed for a fast change of temperature, and showing on the other hand only a moderate resistivity, so that only an uncritical electric voltage is needed to achieve the electrical heating power. Although, in this case, the required heating currents have values of some hundred Amperes and more, for example 200 Amperes at a voltage of 7 V, such high currents can well be controlled using available semiconductor components. In view of these criteria, stainless steel, titanium and NiCr-containing alloys are suitable materials for the fabrication of the stamp.
[0010] In order to cool the stamp, compressed air is preferably used. Due to the low heat capacity of the stamp, only a short time is needed to cool it down by directing compressed air against it, so that cycle times of about one second are feasable.
[0011] In the preferred embodiment of the device, a stamp carrier plate is provided with a plurality of stamps forming a group, and the same number of carrier plates is inserted into the corresponding openings of a supporting plate opposite the stamps. Preferably, the stamps are electrically connected in series at the stamp carrier plate, so that the intensity of the heating current does not increase. This measure is expedient especially if the stamp carrier plate together with the stamps is reciprocated with respect to the carrier plates incorporated in the supporting plate, in which case the electrical leads for the heating current have to be moved accordingly. As a consequence, large conductor cross-sections would be disadvantageous.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Further features and advantages of the invention will become apparent from the following description and from the accompanying drawings to which reference is made. The drawings show:
[0013] FIGS. 1 to 4 diagrams illustrating a first variant of the method according to the invention;
[0014] [0014]FIG. 5 a schematic perspective view of the device;
[0015] [0015]FIG. 6 an enlarged sectional view of a part of the device;
[0016] [0016]FIG. 7 an enlarged perspective view of a part of the device;
[0017] [0017]FIG. 8 a perspective view in detail of a stamp of the device;
[0018] [0018]FIG. 9 a sectional view, showing a variant of the embodiment shown in FIG. 2;
[0019] [0019]FIG. 10 a partial section of another embodiment; and
[0020] [0020]FIG. 11 diagrams illustrating a second variant of the method according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] In the first variant of the method, schematically depicted in FIGS. 1 to 4 , fibers 1 of synthetic material are bunched, in particular by means of an apertured plate 2 for example, and set on a stop 3 . The stop 3 may be flat or comprise a shaped surface with a profile and can hence be applied in the known way to give the bristles an overall contour by shifting them axially. The free fiber ends are situated opposite a stamp 4 that has a solid body and can be heated by means of an electric current passing through the body. The stamp 4 may have any form, in particular one showing a shaped surface. The stamp 4 is thin-walled and has a low heat capacity. Hence, it can be heated very rapidly using a resistance heating and cooled again equally rapidly with the help of a flowing cooling agent.
[0022] In a first step the stamp 4 is heated to a temperature T 1 . In a second step the stamp 4 is pressed onto the fiber ends, as shown in FIG. 1 and 2 , melting together and shaping the fiber ends. In a third step, FIG. 3, the stamp 4 is then cooled quickly by compressed air directed against it. Only then, in a fourth step, the stamp is separated from the now melted together and cleanly shaped fiber ends.
[0023] In the described embodiment of the device, it serves for the fabrication of tooth brushes, wherein a carrier plate, comprising tufts of bristles, is inserted into a brush head and welded to it. Details of such a device can be taken from the EP 0 972 464 A1 and the EP 0 972 465 A1.
[0024] A mount 10 (FIG. 5) is provided with a stamp carrier plate 12 that can be reciprocated vertically by means of guide rods 14 , the actuation being assured by a pneumatic cylinder 16 . To the bottom side of the carrier plate 12 four support bases 18 are attached, carrying each a heatable stamp 20 directed downwards. Below the carrier plate 12 , spaced from and parallel to it, is provided a supporting plate 22 having four openings 24 opposite to the stamps 20 . A carrier plate 26 made of synthetic material, comprising an array of holes corresponding to the desired array of bristles, is insertable into each of these openings 24 .
[0025] Via a compressed-air piping 28 branching at the stamp carrier plate 12 , the device can be supplied with blasts of compressed air directed against the stamps 20 . Furthermore, two flexible high-current cables 30 , able to carry an electric current controlled by pulse width modulation, are connected to the stamp carrier plate 12 .
[0026] [0026]FIG. 6 shows details of a single stamp of the device. This stamp 20 whose structure is better understood from FIG. 5 consists of a metallic body, especially of stainless steel, with a thin-wall stamp plate 20 a and two bent-off high-current terminals in the form of right-angled contact shoes 20 b , 20 c formed thereon. These contact shoes 20 b , 20 c in addition serve the attachment of the stamp 20 to the support bases 18 , which in turn are employed for electrically connecting the four stamps 20 . As can be seen from FIG. 6, the current cables 30 are each directly connected to a cable shoe. The support bases 18 are provided with openings 18 a being connected through the stamp carrier plate 12 to the compressed-air piping 28 and directing the compressed-air flow against the stamp plate 20 a.
[0027] As further can be seen from FIG. 6, the carrier plate 26 is inserted into the opening 24 of the supporting plate 22 in such a way that its circumferential border is held in place by the boundary of the opening 24 . The tufts of bristles 32 inserted into the holes of the carrier plate project 2 to 3 millimeters out of the side of the carrier plate 26 facing the stamp 20 and are propped at the opposite side at a push plate or stop 34 . This stop can either be flat or comprise a shaped surface that in addition can be used to give rise to a profile of the tufts of bristles by axially shifting the individual bristles within a single tuft. The surface of the stamp 20 facing the carrier plate is provided with sharp projections 36 , whose tips point towards the area of the carrier plate surrounding the holes and hence the tufts of bristles. The surface of the stamp facing the carrier plate further is provided with a non-stick coating.
[0028] As is apparent from FIG. 7, the four stamps 20 at the stamp carrier plate 12 are electrically connected in series. The connection of the stamps can be realised by individual cable sections or equally by an appropriate design of the support bases 18 .
[0029] From the representation of the FIG. 8 it is apparent that the stamp is a thin-wall member that is given a high inherent stability by suitable roundings, formed-on ledges, a bent-up circumferential border and the angled structure of the contact shoes.
[0030] As further is apparent from FIG. 7, at least one of the stamps 20 , though preferredly each stamp, is associated with a temperature probe 40 . The one or each of the temperature probes 40 is connected to a controller 42 driving an electric current supply 44 , to the output terminals of which are connected the current cables 30 . The current supply 44 preferably operates with pulse width modulation.
[0031] In a typical embodiment of the device, the body of each stamp 20 is made of stainless steel. The wall thickness near the stamp plate 20 a is only a fraction of a millimeter. With a length of the stamp plate of about 20 millimeters and a width of about 10 millimeters, there results a heating power of about 1400 W, corresponding to a current of 200 Amperes at 7 V. In this case, the body of the stamp has such a low heat capacity that the heating/cooling-cycle achievable is of the order of one second. The fast cooling is a consequence of the controlled blast of compressed air alone, being directed against the stamp plate.
[0032] In the embodiment shown in FIG. 9, in addition to the supporting plate 22 the carrier plate 26 is overlapped by a movable carrier ring 48 . The carrier ring 48 is provided with a through opening for the passage of the stamp 20 . The carrier ring 48 ameliorates the support at the circumferential border of the carrier plate 26 to prevent it from a deformation effected by the heated stamp 20 . With this embodiment of the device an excellent dimensional accuracy of the carrier plate 26 is assured, resulting in a clean joining with the brush head during the subsequent welding.
[0033] In the embodiment shown in FIG. 10, the through holes are enlarged on the side of the fiber ends to be melted together, the enlargements being cone-shaped in particular. Pressing the heated surface of the stamp on the plasticized mass of the fiber ends melted together, the mass is pressed into these enlargements resulting in frustum-shaped knobs at the melted fiber ends, that are referenced 5 in FIG. 10. Due to these knobs, the “pull-out force”, i.e. the tensile force in the direction “A” in FIG. 10 at which a tuft releases from the carrier plate 26 is increased strongly. An additional enhancement is achieved in that at least part of the plasticized mass is transformed into a continuous layer by pressing the heated stamp onto it, as indicated at 6 in FIG. 10. To facilitate the inserting of the tufts of fibers 1 into the through holes of the carrier plate 26 , these through holes are enlarged on the other side of the carrier plate 26 too, as indicated at 7 in FIG. 10.
[0034] The second variant of the method as depicted schematically in FIGS. 11 to 15 starts out from the same disposition as the first variant of the invention (FIGS. 1 to 4 ). Identical parts are indicated by the same reference numerals.
[0035] The first two steps of the second variant of the method correspond to the first two steps of the first variant. The stamp 4 is heated to a first temperatuer T 1 , and pressed onto the fiber ends, as shown in FIGS. 11 and 12. In a third step the stamp 4 is now withdrawn from the fiber ends, keeping, however, its temperature constant (FIG. 13). Occasionally, after having withdrawn the stamp 4 at the temperature T 1 , some material of the fibers still adheres to it. In order to remove this material, the stamp, in a fourth step, is heated to a second, higher temperature T 2 (FIG. 14) that is chosen such that in a pyrolysis process the material of the fibers first desintegrates into monomers before being vaporized. In this way, the stamp 4 is clean again and does not have any residual deposits. In the final step the stamp 4 is cooled to the temperature T 1 by directing compressed air against it (FIG. 15). Using fibers of polyamide, the temperature T 1 lies between 250° C. and 300° C. and the temperature T 2 between 600° C. and 700° C.
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In a method of melting together axial ends of bunched fibers of thermoplastic material, the fiber ends are brought into contact with the heated surface of a stamp. The body of the stamp is heated by controlling an electric current passing through it. In one embodiment the stamp is cooled by a flow of compressed air before the stamp is separated from the fiber ends. In another embodiment, the stamp is separated from the melted fiber ends, heated to a higher temperature to vaporize any residual fiber material, and cooled by exposure to compressed air until it has no more than the temperature for melting the fiber material.
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FIELD
This invention relates to the field of integrated circuit manufacturing. More particularly the invention relates to the treatment of platens for rendering them more useful in dry etching processes.
BACKGROUND
It is desirable to reduce extraneous particulate matter in the environments in which integrated circuits are processed. One reason for this is that when airborne particles are deposited on the surface of the substrate on which the integrated circuits are formed, the particles tend to create processing defects in the integrated circuits, thus reducing the yield of the process and increasing the manufacturing costs of the integrated circuits.
One method by which particles are generated during processing is by the degradation of a surface in a reaction chamber. For example, ceramic materials tend to be highly favored in certain types of reaction chambers because, among other things, they tolerate heat and tend to be non reactive in many environments. However, many ceramic materials tend to have relatively rough surfaces and relatively large pores which crack and spall relatively easily, thus creating particles. In some processes, where gases are distributed though the system, the particles thus created may become entrained in the flowing gases and redeposited on the substrates being process.
For example, dry etching is one method used to form integrated circuits on a substrate, such as a semiconductor substrate. In dry etching processes, such as reactive ion etching, an etching gas is introduced by a gas distribution plate into an etching chamber containing the substrate. One problem encountered in such processes is chipping or degradation of the gas distribution plate, which generate particulates of the plate material. These particles from chipping or other degradation of the plate are carried by the etching gas to the substrate and tend to be detrimental to the integrity and quality of the semiconductor substrate, as described above.
What is needed, therefore, is a system by which gas distribution plates are less susceptible to chipping and generation of particles so as to provide gas distribution plates which are more suitable for their intended purpose.
SUMMARY
The above and other needs are met by an improved platen for use in a dry etching process for substrate production. In a preferred embodiment, surfaces of the platen that are susceptible to chipping and particle generation from the dry etching process are coated with silicon carbide to render such surfaces less susceptible to chipping and particle generation. The coating is preferably applied to a thickness of at least about sixty microns by chemical vapor deposition.
It has been observed that the coating is particularly suitable for coating ceramic silicon dioxide distribution plates. Such plates are desirable from a cost basis, but are fragile and prone to chipping and particle generation. By coating the plates in accordance with the invention, the plate is rendered less prone to chipping and particle generation without unduly affecting the desirable cost attributes of the plates. Thus, the invention advantageously enables improved performance in an economical manner.
BRIEF DESCRIPTION OF THE DRAWING
Further advantages of the invention are apparent by reference to the detailed description when considered in conjunction with the FIGURE, which is not to scale so as to more clearly show the details, and which depicts a platen according to the present invention.
DETAILED DESCRIPTION
With reference to FIG. 1, there is depicted a preferred embodiment of a platen, such as gas distribution plate 10 , in accordance with a preferred embodiment of the invention. The plate 10 preferably includes a base plate member 12 having a configuration suitable for distributing gas in a dry etching process, with a thickness defined between opposite substantially planar surfaces 14 and 16 .
In a preferred embodiment, the base plate member 12 is made of ceramic silicon carbide. Such plates are desirable in that they are relatively inexpensive, but tend to be relatively fragile. Further, the surface of plates formed from such ceramic materials tends to be rather rough, which roughness provides points that are relatively easily fractured from the surface of the base 12 , such as by thermal or mechanical stresses. As a result, such plates tend to chip during the etching process such that particles of the plate material are generated and carried to the substrate during the etching process. This undesirably affects the etching process and may affect the quality of the substrate.
In accordance with the invention, it has been discovered that significant reductions in the chipping of the plates and the generation of particles may be achieved by applying to at least a portion of the plate member 12 , such as the surface 16 , a coating 18 . In a preferred embodiment, the coating 18 is a film of silicon carbide having a thickness of at least about sixty microns. The silicon carbide material for the coating 18 is preferred, because it tends to be nonreactive to many processes, such as dry etching processing. However, it is appreciated that other relatively nonreactive materials that are compatible with the materials, processes, and intended functions as described herein may also be used. It is understood that the coating 18 may additionally applied to other surfaces of the plate member 12 such as the surface 14 and the side edges of the plate 12 .
A preferred method for coating the plate member 10 includes the following steps. Most preferably, the edges of the base plate member 12 are chamfered to reduce relatively sharp edges. In a cleaning step, the plate is first cleaned using an acid solution and ultrasonic treatment. A preferred acid solution is hydrofluoric acid, in a concentration of from about five percent to about ten percent. After the cleaning step, the plate is dried in an oven, preferably at a temperature of from about one hundred centigrade to about two hundred centigrade, for a time of from about six hours to about twelve hours. Next, the coating 18 is applied, preferably as by chemical vapor deposition.
Application of the coating by chemical vapor deposition is particularly preferred because the coating is applied in a highly conformal manner, and the coating is deposited as a relatively dense layer. Further, the surface of the coating is preferably relatively smooth, and preferably does not have small cusps or other protrusions that would tend to easily be chipped away from the surface of the coating and become airborne, such as in a process where a gas delivery system is used, and in a portion of the process reactor where such chips would tend to become lofted in gases and swept through other portions of the reactor. Further, chemical vapor deposition tends to produce a film with relatively large grains, which further tends to increase a deposited films resilience to chipping.
The chemical vapor deposited coating 18 tends to fill in any cracks that are present in the base member 12 , as well as generally seal the surface of the base member 12 . Although a platen comprised entirely of a vitreous material also tends to have reduced particulate generation, such platens are quite expensive. A platen 10 formed according to the method as described herein provides the benefits of reduced particulate generation and reduced cost of manufacture.
The thickness of the coating 18 is preferably selected, at least in part, based upon the surface roughness or porosity of the base member 12 . For example, a surface 16 that is rougher or has larger pores is preferably given a thicker coating of the sealing material 18 , so as to encase all of the points of the rough surface and fill the pores of the base member 12 . On the other hand, a base member 12 with a smoother surface and smaller pores, even though still fragile and prone to cracking, may preferably receive a thinner coating, which is sufficient to encase the points of the smoother surface and seal whatever cracks and pores may be present.
In a most preferred embodiment, the base member 12 is formed of ceramic silicon carbide having a density of from about sixty percent to about eighty percent, and the coating 18 has a density of at least about ninety-nine percent.
The foregoing description of preferred embodiments for this invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the invention and its practical application, and to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as is suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.
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A platen for use in a dry etching process for substrate production, the platen having a surface susceptible to chipping and/or particle generation from the dry etching process and a coating applied to at least a portion of the surface for rendering the surface less susceptible to chipping and/or particle generation, the coating comprising a silicon carbide coating
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FIELD OF THE INVENTION
The present invention is in the general field of valves, more specifically faucet valves. The present invention concerns such valves that control the flow of fluids by the action of a rotatory stem that drives a seat-washer against a seat.
BACKGROUND OF THE INVENTION
The rapid wear of the seat-washer found in valves and faucets is caused by the rotation of the seat-washer against a seat. Rotation of the seat-washer in many water faucet designs occurs as the seat-washer is driven against a valve seat by a rotating stem.
U.S. Pat. No. 2,403,028 to Smith teaches a means to prevent further rotation of a resilient washer after it has been rotationally mated with a valve seat. Smith discloses a faucet in which a handle is rotated so that a stem brings pressure between a seal and a valve seat so that liquid flow is cut off. As the handle is rotated further in the Smith faucet, the stem travels a small additional distance downward and encounters a metal stop, preventing further travel. This feature prevents excessive compression and destructive rotation of the resilient material of the washer. Smith does not, however, teach any means to prevent rotation of the resilient washer as it mates with the valve seat.
U.S. Pat. No. 4,106,747 to Malacheski teaches a special washer construction means intended to prevent any rotational engagement between a resilient washer and a valve seat. However, the special washer must itself be replaced and has teeth that could break off and interfere with the operation of the faucet.
U.S. Pat. 2,271,391 to Drake discloses an assembly in which a washer is restricted from rotating with respect to the valve seat. Drake teaches a stem-borne lug that intermeshes with a channel between two vertical lugs formed in the valve shell.
Thus, it is apparent that the wearing of faucet seat-washers by their action against faucet seats is an existing problem that leads to the annoyance of users, water loss, and the necessity of frequent repairs to existing faucets.
SUMMARY OF THE INVENTION
A principal objective of the present invention is to significantly reduce wear of the resilient seat-washer of a valve. The present invention achieves a reduction in wear by preventing the seat-washer from rotating against the seat as the valve is closed. The decreased wear of the seat-washer increases its service life thereby allowing the valve, or faucet, to operate much longer before the seat-washer fails and the valve leaks until the seat-washer is replaced. Accordingly, faucets incorporating the present invention require less maintenance than conventional faucets and tend to conserve water due to decreased leakage by failed seat-washers.
The present invention provides a non-circular slider assembly with an attached resilient seat-washer, which slides within a broached cavity of a complementary shape. Embodiments of the invention are envisaged which have a square, hexagonal or octagonal slider assembly. In a preferable embodiment of the invention the slider assembly has a hexagonal cross-section. It will be appreciated by those of skill in the art, that the slider assembly and the complementary cavity may be of any non-circular shape to achieve the purposes of the present invention. In embodiments of the invention the slider assembly is moved longitudinally by a rotatory valve stem. In some embodiments of the present invention, the valve stem drives the slider assembly and pressure of the fluid serves to lift the slider assembly from the seat when the valve stem is withdrawn. In other embodiments of the present invention the slider assembly is connected to the valve stem in a manner that allows free rotation of one relative to the other so that withdrawal of the valve stem lifts the slider assembly from the seat. The rotatory stem is provided with a helical ridge mating with a faucet body having a complementary helical groove so that, as the stem is rotated, the stem is advanced towards or withdrawn from a sealing seat. The non-circular cavity that receives the slider is broached in the faucet body concentrically with the helical groove.
In a particular embodiment of the present invention, the stem has a helical ridge extending outwardly around its surface and a hexagonal slider is rotatably connected to the stem. The helical ridge is adapted to mate with a complementary helical groove on the inside wall of a faucet body. When the handle of the stem is rotated by a user, the stem, and the hexagonal slider assembly driven by it, are moved towards or away from a seat, depending on the rotation direction, clockwise or counterclockwise, by the interacting force generated between the pair of helical threads. Preferably, embodiments of the present invention have renewable seats.
The hexagonal slider assembly and the stem have two principal embodiments. In both of these embodiments, the slider assembly is attached to the stem in a manner permitting relative rotation at their interface. For example, in a permanently assembled embodiment of the invention, a tubular extension of the internal end of the stem is loosely swaged into a groove about a circular extension of the hexagonal slider. In a demountable embodiment of the invention, a collar is loosely attached to the hexagonal slider by a screw, and the collar has an internal thread by which it is attached to the end of the stem which is threaded to be complementary thereto.
In another embodiment of the present invention, the slider assembly is not attached to the stem but is merely propelled by it. In this embodiment of the invention, stem rotation drives the slider assembly against the seat to cut off or adjust the rate of fluid flow. When the stem is withdrawn by rotating its handle, the freely moving slider assembly is forced away from the seat by the fluid pressure.
The present invention further encompasses a method of making a washer-saving valves such as those described herein. Such a method comprises producing a valve body having an inner surface by processes known to those of skill in the art. Such a valve body has an inlet and an outlet and a seat which is preferably replaceable, at the inlet. A helical groove is machined into the inner surface of the valve body, and a non-circular bore is broached concentrically with the helical groove also into the inner surface of the valve body.
A valve stem is machined to have a helical ridge on the outer surface thereof complementary to the helical groove in the valve body, and to have a seat-facing end.
A slider assembly is machined to have a first and second end so that at least a portion of the slider assembly has a cross-section complementary to the shape of the broached non-circular bore and which sidably fits therein. The first end of the slider assembly is made so that it can rotatably interact with the seat-facing end of valve stem and the second end of the slider assembly is made so that a seat-washer may be removably attached thereto.
An embodiment of the present invention is assembled by rotatably connecting the first end of the slider assembly to the seat facing end of a valve stem, attaching a seat-washer to the second end of slider assembly and inserting the assembled stem into the valve body by rotating the helical ridge of the valve stem in the helical groove of the valve body.
In use, when the valve stem of an embodiment of the present invention is advanced by rotation through the valve body, the valve stem advances the seat-washer against the seat as the non-circular slider slides within the broached non-circular bore. Since the slider assembly is prevented from rotating by the non-circular bore the seat-washer borne upon the slider assembly does not rotate against the seat upon contact therewith.
Accordingly, the present invention overcomes the rapid wear of the seat-washer found in conventional faucets caused by the rotatory grinding action of the seat-washer against the seat as the valve is tightened to turn the water off. By eliminating the rotation of the seat-washer when the user rotates the handle connected to the stem the present invention eliminates the wear generated between the valve seat and the seat-washer when the faucet handle is rotated to open or close the valve and also substantially eliminates friction between the washer and the seat. As a consequence, embodiments of the present invention are very easy to open and close and have a substantially extended service life when compared with conventional faucets. The ease of use is advantageous when used by those with infimities such as arthritis, and the extended service life is of particular importance in commercial establishments such as restaurants, hotels and hospitals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is partially sectioned view showing the elements of a complete faucet of the present invention.
FIG. 2 is a sectional view showing the elements of a preferred embodiment of the present invention.
FIG. 3 is a partially sectioned view of the stem shown in FIG. 2, before it is swaged to the slider assembly shown in FIG. 4.
FIG. 4 is a partially sectioned view of a portion of a slider assembly of the present invention adapted to mate with the stem of FIG. 3.
FIG. 5 is sectional view showing the elements of another embodiment of the present invention.
FIG. 6 is a view of the stem shown in FIG. 5.
FIG. 7 is an "exploded" view showing the elements of a portion of a slider assembly of the present invention as embodied in FIG. 5.
FIG. 8 is a longitudinal cross-section of a hollow housing of the present invention having a hexagonal broach.
FIG. 9 is a transverse cross-section of the hollow housing shown in FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
Referring now more particularly to the drawings and specifically to FIG. 1 thereof, one embodiment of a faucet-type valve of the present invention is there shown as a partial cross-sectional view. FIG. 1 shows a hollow housing 102, and a depending inlet 104 with a seat 105. The hollow housing is provided with an outstanding outlet 106 and both the inlet 104 and the outlet 106 communicate with the interior of the hollow housing 102. The interior of the hollow housing opens upwardly through an internally threaded opening for threadedly receiving the bonnet 144. A gland nut 146 closes the upper opening of the housing 102 in a substantially conventional manner. The bonnet 144 and the gland nut 146 are provided with a through passageway, through which extends the stem 108. It will be appreciated that bonnets of different designs may be used with faucets of the present invention so as to conform with or enhance the decor of a room in which the faucet is used.
On its outer end the stem 108 is provided with a handle 148 which may be decorative or utilitarian depending on the location of the finished fitting. Within the faucet the stem 108 is provided with external helical threads 110 in mating engagement with internal helical threads 112 of the hollow housing 102. Thus, the stem is mounted for rotative movement within the housing, and longitudinal displacement upon said rotative movement.
Associated with the stem 108 is a slider assembly 118 having a cross-section of a regular hexagon 132 that slides within a hexagonal cavity that is broached into the hollow housing 102 concentrically with the helical threads 112. The seat-adjacent end 130 of the slider assembly 118 has a seat-washer 126 attached thereto by a screw 128.
FIG. 2 shows an embodiment of a faucet-type valve of the present invention having a hollow housing 202, a depending inlet 204 and a seat 205. The hollow housing is provided with an outstanding outlet 206 both the inlet 204 and outlet 206 communicating with the interior of the hollow housing 202. The interior of the hollow housing opens upwardly through an internally or externally threaded opening (not shown) for threadedly receiving a bonnet or plug (not shown) so closing the upper opening of the housing in a substantially conventional manner. The bonnet or plug is provided with a through passageway, through which extends the stem 208.
On its outer end the stem may be provided with a handle. Within the faucet the stem 208 is provided with external helical threads 210 in mating engagement with internal threads 212 of the hollow housing 202. Thus, the stem is mounted for rotative movement within the housing, and longitudinal displacement upon said rotative movement. For clarity of illustration, the valves illustrated herein restrict fluid flow upon clockwise rotative movement of the stem within the housing, however it will be appreciated that embodiments of the present invention having a stem with an external helical ridge and a corresponding mating internal helical groove that restrict fluid flow upon counterclockwise rotative movement of the stem within the housing are intended to be encompassed by the disclosure of the present invention.
The stem is in general axial alignment with the inlet, and the inner end of the stem is provided with a generally circular cavity or recess 214. The inner wall of the cavity is bounded by a generally circular peripheral rim 216.
Associated with the stem 208 is a slider assembly 218. A generally cylindrical extension 220 of the stem-proximal end of the slider assembly 218 with a basal groove 222 therearound is positioned within the generally circular cavity 214 of the stem 208 and is retained within the cavity by the lip of the peripheral rim 224 that is swaged into the basal groove 222.
A cross-section of the main body of the slider assembly 218 shown in FIG. 2, has the form of a regular hexagon 232, and the slider assembly 218 slides within a hexagonal cavity that is broached into the hollow housing 202 concentrically with the helical threads 212. It will be appreciated by those of skill in the art, that the slider assembly and the complementary cavity may be of any non-circular shape to achieve the purposes of the present invention.
The seat-adjacent end 230 of the slider assembly 218 has a seat-washer 226 attached thereto by a screw 228.
Generally, the depending inlet and the outstanding outlet of the valve of the present invention may be provided with internal or external threading to allow for the attachment of standard plumbing fittings thereto. The seat-washer of the faucet of the present invention is generally a conventional seat-washer made of rubber, composition, fiber or other conventional material. The attachment screw is shown as a right hand screw in FIG. 2. However such a screw may have a left-hand or right-hand thread. The seat of a valve of the present invention may be permanently affixed or may be replaceable. If replaceable, the seat may be screwed into position or located by other means known to those of skill in the art.
The components of this embodiment of the faucet of the present invention illustrated in FIG. 2 may be further appreciated by consideration of FIGS. 3 and 4. FIG. 3 shows a portion of a stem 308 in partial cross-section before assembly onto a slider assembly. FIG. 3 shows a cross-section of the peripheral rim 320 of the generally circular cavity 314 of the stem 308 and the lip 324 of the peripheral rim that is swaged inwards upon assembly of the stem with a slider assembly.
FIG. 4 shows a portion of a slider assembly 418 in partial cross-section before assembly with a stem. FIG. 4 shows a cross-section of the generally cylindrical extension 420 of the slider assembly 418 and the basal groove 422 adjacent to the hexagonal portion 432 of the slider assembly 418.
Referring to FIG. 5, a second embodiment of a faucet-type valve of the present invention is there shown having a hollow housing 502, a depending inlet 504 and a seat 505. The hollow housing is provided with an outstanding outlet 506 both the inlet 504 and outlet 506 communicating with the interior of the hollow housing 502. The interior of the hollow housing opens upwardly through an internally threaded opening (not shown) for threadedly receiving a bonnet or plug (not shown) so closing the upper opening of the housing in a substantially conventional manner. The bonnet or plug is provided with a through passageway, through which extends the stem or stem 508.
On its outer end the stem may be provided with a handle. Within the faucet the stem 508 is provided with external helical threads 510 in mating engagement with internal helical threads 512 of the hollow housing 502. Thus, the stem is mounted for rotative movement within the housing, and longitudinal displacement upon said rotative movement.
The stem is generally in axial alignment with the outlet, and the inner end of the stem is provided with a threaded extension 534.
Associated with the stem 508 is a slider assembly 518. The slider assembly 518 has rotatably attached at its stem-proximal end 536 a threaded cup 538 that is threadedly engaged with the threaded extension 534 of the stem 508. The threaded cup 538 is rotatably attached to slider assembly 518 by a screw 540 engaged in a threaded recess 542 in the slider assembly 518.
A cross-section of the main body of the slider assembly 518 has the form of a regular hexagon 532, and the slider assembly 518 slides within a hexagonal cavity that is broached into the hollow housing 502 concentrically with the helical threads 512.
The seat-adjacent end 530 of the slider assembly 518 has a seat-washer 526 attached thereto by a screw 528.
The components of this second embodiment of the faucet of the present invention illustrated in FIG. 5 may be further appreciated by consideration of FIGS. 6 and 7. FIG. 6 shows a portion of a stem 608 in partial cross-section before assembly onto a slider assembly. FIG. 6 shows the threaded extension 634 of the stem 608 that is threadedly engaged with the threaded cup of the slider assembly upon assembly.
FIG. 7 shows in partial cross-section an exploded portion of a disassembled slider assembly 718 before assembly with a stem. FIG. 7 shows a cross-section of the threaded cup 738 together with the screw 740 that holds the threaded cup 738 to the hexagonal portion 732 of the slider assembly 718. Also shown is the threaded bore 742 with which screw 740 engages to hold threaded cup 738 in rotatory attachment to slider assembly 718.
FIGS. 8 and 9 illustrate the detailed structure of a preferred form of a hollow housing of the present invention as has been described with respect o the embodiments shown in FIGS. 1 through 7. FIG. 8 shows a longitudinal cross-section of a portion of a hollow housing 802 showing the internal circular helical threads 812. Section line 9--9 shows the location of the transverse cross-section shown in FIG. 9.
FIG. 9 shows a transverse cross-section of a hollow housing 902 as it would be seen viewed from the handle end of a hollow housing. FIG. 9 shows a portion of the internal circular helical threads 912 shown cut-through and the location of hidden portions thereof shown as a dashed line 950. The hexagonal axially-located cavity that is broached into the hollow housing 902 concentrically with the helical threads 912 is shown. The seat 905 surrounding inlet 904 is viewed through the hexagonal broached cavity. Section line 8--8 shows the direction of view of the longitudinal cross-section shown in FIG. 8.
It will be appreciated that any non-circular shape may be used for the slider and complementary cavity. When assembled, the non-circular broached cavity receives the complementary non-circular slider assembly and prevents it from rotating relative to the seat upon rotation of the stem.
In operation, a partially open condition being shown in FIGS. 1, 4 and 7, it will there be apparent that the stem is axially rotatable in the hollow housing to shift the seat-washer-bearing slider assembly longitudinally toward and away from the valve seat. In the open condition shown, further closing rotation of the stem would shift the seat-washer closer toward the valve seat. As rotation of the slider assembly is restrained by interfitting engagement of its hexagonal body with the broached hexagonal bore of the faucet body, relative rotation may only occur between the stem and the slider assembly. This relative rotation and wear occasioned thereby is spread over substantial areas of lose-fitting relatively hard materials, so that only negligible wear occurs. Thus, the seat-washer of a faucet of the present invention is moved substantially non-rotatably into bearing-engagement with the seat, and is compressed thereagainst by force transmitted from the stem through the slider assembly.
It will be appreciated that the seat-washer fit on the seat is not critical, and a single size of seat-washer may be employed with a range of different sizes of stems. Thus, in the relatively less frequent event of replacing seat-washers, which is simply accomplished by merely attaching a new seat-washer to the slider assembly, it is not necessary that as great a number of different seat-washers be inventoried.
From the foregoing, it is apparent that the present invention provides a valve construction which substantially eliminates rotative frictional engagement between the seat-washer and valve seat to greatly increase seat-washer life and ease faucet operation, and otherwise fully accomplishes its intended objects. For purpose of clarity of understanding, embodiments that use a hexagonal slider are illustrated herein. However, it is to be understood that sliders of any non-circular shape are within the spirit of the invention and although the present invention has been described in some detail by way of illustration for purposes of clarity of understanding, it is to be understood that changes and modifications may be made within the spirit of the invention.
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The present invention provides a novel faucet with a non-circular slider assembly to which a resilient seat-washer is attached. In a preferable embodiment of the invention the slider assembly has a hexagonal cross-section. In embodiments of the invention the slider assembly is driven by a rotatory stem operated with a handle. The rotatory stem is provided with a helical groove mating with a faucet body of a complementary shape so that upon rotation of the stem the slider assembly is advanced towards or withdrawn from a sealing seat. Thus, when the handle of the stem is rotated by a user, the stem and the hexagonal slider assembly associated with it, are moved by the interacting force generated between the pair of helical threads, towards or away from the seat depending on the rotation direction.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims priority from Japanese Patent Application No. 10-357690, filed Dec. 16, 1998, the contents being incorporated herein by reference, and a continuation of PCT/JP99/03326 filed on Jun. 22, 1999.
BACKGROUND OF THE INVENTION
The present invention relates to a carrying strap attaching structure in a portable type electronic apparatus. The present invention also relates to an electronic apparatus to which a strap can be attached.
A case of a portable type electronic apparatus, such as a portable telephone, a portable personal computer, a hand-held terminal (hereinafter referred to as HHT) or a video camera, is generally provided with a strap for securing the case in a closed condition and for protection against dropping. For this purpose, each such portable type electronic apparatus has a structure for mounting a strap.
There are several kinds of straps, such as a neck strap to hang the apparatus from a user's neck or a wrist strap through which a user's wrist is passed and from which the apparatus hangs.
BACKGROUND ART
A conventional method/apparatus, for attaching a strap to a portable type electronic apparatus (hereinafter referred to as a body), is shown in FIGS. 13 and 14, in which a strap fitting metal member is arranged in the housing of the electronic apparatus. In FIGS. 13 and 14, a metal member 20 is fixed to a lower cover 4 by a screw 21 . FIG. 14 is a sectional view, taken on line XIV—XIV of FIG. 13, specifically showing a corner portion of the housing.
The upper cover 3 and the lower cover 4 making up the housing are fitted to each other with screws 22 . Also, an upper damper 5 and a lower damper 6 are mounted at the corner portion of the upper cover 3 and the lower cover 4 , respectively. These dampers 5 and 6 have the function of absorbing shocks applied to the electronic apparatus.
In the example shown in FIGS. 13 and 14, the metal member 20 is formed with a rectangular hole 20 ′ in an L-shaped bottom portion thereof. A strap is attached to the electronic apparatus by inserting a tape portion of the strap into the hole 20 ′.
The method using the metal member 20 as shown in FIGS. 13 and 14, however, is costly due to the need for the metal member 20 . Also, all portable type electronic apparatuses are desirably as small as possible. In the method/apparatus shown in FIGS. 13 and 14, however, a space for mounting the metal member 20 is required, which is a stumbling block to achieving a decreased size of the apparatus, on the one hand, and limits the position for mounting the metal member 20 , on the other hand, thereby posing the problem that the strap cannot necessarily be mounted at a convenient position.
In another conventional method/apparatus, as shown in FIG. 15, a screw-receiving metal member 23 is arranged in a housing, of upper and lower cases 3 and 4 , respectively, and the tape portion 25 of the strap is mounted to another metal member 24 , which is inserted and threaded into the threaded hole of the screw-receiving metal member 23 , to thus mount the strap 25 to the housing. Still another conventional method/apparatus is known in which, as shown in FIG. 16, a post 26 for binding the strap is integrally formed with the upper case 3 as disclosed in Japanese Unexamined Patent Publication No. 9-55587.
In the conventional method shown in FIG. 15, threaded members 23 and 24 are required on the housing and the strap 25 , respectively, resulting in increased cost and, because the screw-receiving metal member 23 is arranged horizontally in the side of the upper cover 3 , a slide mechanism is required in the die for molding the upper cover 3 , thereby leading to the disadvantage that the die is complicated.
Also, in the conventional method/apparatus shown in FIG. 16, the circular post 26 extends between the upper and lower walls of the upper cover 3 , so a slide mechanism is required in the die for molding the upper cover 3 , as in the conventional method/apparatus shown in FIG. 15, thereby similarly leading to the disadvantage that the die is complicated.
As described above, the conventional methods pose the problems that the cost of the portable type electronic apparatus is increased, the strap mounting position is limited and the die is complicated, introducing an increased cost.
SUMMARY OF THE INVENTION
The object of the present invention is to solve the above-mentioned problems and to provide a strap attaching structure for an electronic apparatus intended to reduce the apparatus size without increasing the cost.
According to the present invention, the housing of the electronic equipment is divided into an upper cover and a lower cover, both covers being fixed at a boss formed on at least one of the covers. The upper cover or the lower cover is molded integrally with the boss such that a space for mounting the strap is formed around the boss when the upper cover and the lower cover are assembled together.
With the structure according to the present invention, unlike the conventional methods/apparatuses, the space or the post for mounting the strap is formed with the upper and lower cover assembled. As a result, the die for producing the upper cover or the lower cover is not required to have a slide mechanism and therefore a die for fabricating same is not complicated.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will be described in more detail, below, with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view showing an electronic equipment according to a first embodiment of the present invention;
FIG. 2 is a perspective view as taken along arrow II in FIG. 1;
FIG. 3 is a sectional view taken in line III—III in FIG. 2;
FIG. 4 is a perspective view showing a portion of the lower cover;
FIG. 5 is a bottom view of the upper damper;
FIG. 6 is a perspective view showing a second embodiment of the present invention;
FIG. 7 is a perspective view showing a third embodiment of the present invention;
FIG. 8 is an exploded perspective view showing a fourth embodiment of the present invention;
FIG. 9 is a view taken along arrow IX in FIG. 8;
FIG. 10 is a perspective view showing an example of the upper cover;
FIG. 11 is a perspective view showing an example of the lower cover;
FIG. 12 is a partial view showing the upper cover of FIG. 10 and the lower cover of FIG. 11 assembled to each other;
FIG. 13 is a view for explaining a first conventional structure;
FIG. 14 is a sectional view taken in line XIV—XIV in FIG. 13;
FIG. 15 is a view for explaining a second conventional structure; and
FIG. 16 is a view for explaining a third conventional structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, embodiments of the present invention will be explained with reference to the drawings.
FIGS. 1, 2 and 3 are views showing portable electronic equipment according to a first embodiment of the invention, and especially illustrate an apparatus called a hand-held terminal.
FIG. 1 shows an outer appearance of a hand-held terminal 1 (hereinafter referred to as an HHT) to which a neck strap 2 is attached. The HHT 1 shown in FIG. 1 includes a screen 15 formed with a touch panel on the front surface thereof. Also, a keyboard 16 , including input keys such as numerical keys and function keys, is arranged on an edge of the screen 15 . The HHT 1 is carried by a user to a work-place and used there to input information while holding it in his/her hand. For this purpose, a hand strap or the neck strap 2 can be attached to the HHT 1 . The user uses the HHT 1 by hanging the neck strap from his neck, for example, to improve operability and reduce fatigue after a long period of use. Also, the strap can prevent the HHT 1 from dropping.
FIG. 1 shows an example in which respective strap attaching structures 17 are arranged at four corners of the terminal 1 and the neck strap 2 is attached to the respective structures 17 at the upper two corners of the HHT. Arbitrary ones of the four strap attaching mechanisms 17 can be used by the user as desired. For example, the two strap attaching mechanisms 17 located at the diagonal corners can be used.
Also, the HHT 1 according to this embodiment includes damper members 5 and 6 at the four corners for protection against dropping.
In FIGS. 1 to 3 , numeral 1 designates a hand-held terminal, numeral 2 a neck strap, numeral 3 an upper cover, numeral 4 a lower cover, numeral 5 an upper damper, numeral 6 a lower damper, and numeral 7 a strap mounting space.
FIG. 2 is a view taken along arrow II in FIG. 1, showing the tape 12 of the strap 2 mounted in a slit 18 formed in the sides of the upper damper 5 and the lower damper 6 . Further, a sectional view taken on line III—III of FIG. 2 is shown in FIG. 3 .
In FIG. 3, the upper cover 3 and the lower cover 4 are formed of plastic, and bosses 8 are integrally formed with respective covers 3 and 4 so that the covers 3 and 4 can be fixed by a screw 9 . The upper cover 3 and the lower cover 4 have outer walls 3 a and 4 a and inner walls 3 b and 4 b , respectively. The inner walls 3 b and 4 b can be joined with each other in opposed relation to each other. As a result, the upper cover 3 and the lower cover 4 make up a case of the HHT 1 . A space 7 , provided around the boss 8 , can be utilized for mounting the strap.
As shown in FIG. 3, the upper cover 3 and the lower cover 4 have bosses 8 formed therewith for fitting the two covers to each other. With the HHT 1 according to this embodiment, a slit-like strap mounting space 7 is formed around the bosses when arranged in abutment against each other.
FIG. 4 shows a portion of the lower cover 4 . The lower cover 4 has the boss 8 and the slit 7 a . In similar fashion, the upper cover 3 has a boss 8 and a slit 7 a (refer to FIG. 4 ). In the case where the inner wall 3 b of the upper cover 3 and the inner wall 4 b of the lower cover 4 are joined with each other, the boss 8 of the upper cover 3 and the boss 8 of the lower cover 4 come into abutment against each other on a straight line. Each boss 8 has a through hole. The slit 7 a of the upper cover 3 and the slit 7 a of the lower cover 4 form the space 7 . Each boss 8 has a free end and each slit 7 a is open, so the die can be released easily when the upper cover 3 and the lower cover 4 are molded integrally with the respective bosses 8 . Each slit 7 a is formed only in a range, corresponding to a quarter of a circle, around the boss 8 .
The upper damper 5 and the lower damper 6 , which are formed of an elastomer having the properties of both plastic and rubber for protection against dropping, are fixed integrally to the upper cover 3 and the lower cover 4 using the screw 9 . The dampers 5 and 6 have some elasticity and can absorb shock which may be exerted on the HHT 1 when dropped. In FIG. 3, each damper is formed of two materials. Specifically, the portions designated by 5 - 1 and 6 - 1 are formed of elastomer, while the portions designated by 5 - 2 and 6 - 2 are formed of plastic. In the example of FIG. 3, the plastic 5 - 2 and 6 - 2 and the elastomer 5 - 1 and 6 - 1 are overlaid one on the other in such a manner as to be located inside and outside, respectively. In other words, the plastic 5 - 2 and 6 - 2 and the elastomer 5 - 1 and 6 - 1 make up the upper damper 5 and the lower damper 6 integrally structured by two-color molding. As described above, these dampers 5 and 6 are mounted at the four corners of the HHT 1 .
The dampers 5 and 6 are each formed with a slit 18 open to the portion of the upper cover 3 and the lower cover 4 corresponding to the position of the strap mounting space 7 (shown in FIG. 2 ). By inserting the tape 12 of the strap into the slit 18 , it is possible to insert the tape 12 of the strap into the strap mounting space 7 . FIG. 5 is a bottom view of the upper damper 5 . The upper damper 5 has an insert-molded metal member 19 having a threaded hole. The screw 9 is threaded into the metal member 19 via the through holes of the two bosses 8 . Thus, the covers 3 and 4 and the dampers 5 and 6 can be fixed with a common screw 9 thereby to form the space 7 around the bosses 8 .
An explanation will be given of the advantage obtained by the use of bosses 8 for mounting the strap, which bosses 8 are arranged for fitting the upper cover 3 and the lower cover 4 to each other. Generally, the upper cover 3 and the lower cover 4 are formed of a comparatively tough resin. In the case where the strap 2 is mounted, however, the portion where the strap 2 is mounted is concentratedly subjected to a load to such an extent that the strap mounting structure 17 is sometimes broken.
According to this embodiment, however, the strap 2 is mounted around the bosses 8 . The screw 9 for joining the covers with each other is inserted into the bosses 8 . The screw 9 is made of a metal and has a considerably higher strength than resin. As a result, the screw 9 inserted into the bosses 8 performs a function of a reinforcing member for the bosses 8 , and the strength required to mount the strap 2 can be secured. Thus, even if the strap 2 is pulled strongly, the strap mounting mechanism (bosses) can be prevented from breaking.
FIGS. 1 to 3 show an example in which the slit 7 a constituting the strap mounting space 7 is formed in both the upper cover 3 and the lower cover 4 . Nevertheless, the slit 7 a can be formed in one of the upper cover 3 and the lower cover 4 . In that case, an opening is formed in the portion of the strap mounting space 7 in contact with the other cover to facilitate the sliding of the die at the time of integral molding.
FIG. 6 is a view showing a second embodiment of the invention and represents a case in which the strap mounting mechanism is configured of the bosses 8 alone. In the example of FIG. 6, a slit 18 is not formed in the upper damper 5 and the lower damper 6 , but the upper cover 3 and the lower cover 4 are so configured as to expose the bosses 8 formed on the covers. An effect similar to that of the first embodiment can be achieved by arranging the strap tape around or binding the string at the forward end of the strap to the circular post formed by the bosses 8 .
FIG. 7 is a diagram showing a third embodiment of the invention. This embodiment shows a case in which a slit 10 is formed in the wall surface portion of the upper cover 3 and the lower cover 4 , and the strap mounting mechanism is configured of the slit 10 . In the example of this embodiment, the strap tape is inserted through the space formed by the slit 10 . According to the third embodiment, unlike in the first embodiment, the member equivalent to the upper damper or the lower damper is not mounted at the corners of the HHT.
FIGS. 8 and 9 are views showing a fourth embodiment of the invention, in which the forward end of the tape of the strap 2 is prevented from being caught in the gap of the strap mounting space 7 in the first or third embodiment. FIG. 8 is a perspective view and FIG. 9 a view taken along arrow IX of FIG. 8 .
In the case of the first embodiment, as shown in FIG. 3, a gap is formed between the bosses 8 and the upper damper 3 or the lower damper 4 . For mounting the strap 2 to the HHT 1 , the tape portion of the strap is required to be inserted into the strap-mounting slit portion, but in this process, the forward end of the tape portion is liable to be caught or involved in the gap between the bosses 8 and the upper damper 3 or the lower damper 4 , with the result that the workability of the strap mounting job is deteriorated to such an extent that the tape portion 12 of the strap fails to be inserted. This is also the case with the third embodiment. In the second embodiment, the bosses 8 are exposed, and therefore the tape portion is not caught. A similar inconvenience occurs, however, in the case where the damper or the like is mounted for shock protection but a gap develops between the bosses and the dampers.
On the other hand, as shown in FIG. 9, according to this embodiment, ribs 11 are formed in the gap between the bosses 8 and the strap mounting space 7 . The ribs 11 extend to or near the wall surface of the cover. Therefore, the tape of the strap can be guided by the ribs 11 , and is not caught in the internal space. In other words, according to this embodiment, the tape inserted in the strap mounting space is less liable to be caught in the gap between the bosses 8 and the damper or the cover wall surface than in other embodiments. Consequently, the workability of the strap mounting job can be improved.
FIGS. 10 and 11 are views showing an example of the upper cover 3 and the lower cover 4 , respectively.
When the upper cover 3 of FIG. 10 and the lower cover 4 of FIG. 11 are assembled together as shown in FIG. 12, the strap mounting structures 17 are formed at the four corners. Three strap mounting structures 17 include the bosses 8 and the strap mounting spaces 7 , as explained heretofore. The remaining strap mounting structure 17 does not include the boss 8 and, instead, the space 7 b is formed around the metal member 19 of the upper damper 5 .
As explained above, according to the present invention, the attachment of the strap is established, utilizing the mounting boss for mounting the upper and lower covers. As a result, a special part for mounting the strap is not required, so that the apparatus cost and the apparatus size can be reduced correspondingly.
Also, the mounting boss is used for attaching the strap, and the screw passes through the boss, so the boss is substantially reinforced by the screw. Thus, there is an effect that a sufficient strength can be secured even when the strap is pulled.
Further, in the case where a strap mounting space is formed in the cover, an opening is formed in the surface of the cover fitted with the other cover eliminates the need of a slide mechanism in the die structure for the cover production and simplifies the equipment production process. In addition, the cover molding cost can be reduced.
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A strap mounting space is formed around a boss formed on an upper cover and a lower cover which, when assembled together, form a case for an apparatus. One, or each, of the upper cover and the lower cover is/are formed integrally with a respective boss, preferably at each corner, so that the respective bosses at corresponding, common corners of the upper and lower covers, when assembled, are in an aligned and abutting relationship. A slits is formed in one of the corners of the upper and lower covers, extending around the respective boss(es) thereof, making up a strap mounting space. A screw 9 is inserted into a corresponding axial hole extending through each boss, affording a sufficient strength of the abutting bosses for supporting the case, with the apparatus therein, by a strap received through the strap mounting space.
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BACKGROUND OF THE INVENTION
This invention relates to soldering machines and methods and more particularly to an improved drag soldering machine and method for the soldering of through-hole printed wiring boards (PWB).
Soldering is widely employed for the fabrication of many different products, especially products in the electronics field and notably through-hole printed wiring boards (PWB). Typically, electronic components with extending leads are connected to circuitry on the PWBs by soldering the leads into preexisting holes on the PWB. For the mating of electronic components to the PWBs a variety of different types of soldering techniques may be employed. The most common technique is wave soldering which involves moving a PWB in one direction across the crest of a stationary, continuously replenished wave of molten solder. The solder wave contacts the bottom of the PWB and simultaneously wets the holes in the PWB and the electronic component leads extending through these holes. Upon moving past the solder wave, excess solder drains away and a quality solder joint remains between the leads and the PWB. Another technique, drag soldering, involves lowering a pallet supporting the through-hole PWB with electronic components in place on the board into a solder bath until the PWB contacts with the solder. The PWB is then dragged a predetermined distance along the surface of the bath, after which it is lifted from the bath. Just as with wave soldering the solder simultaneously wets the holes in the PWB and the electronic leads of the components. After the PWB is lifted from the solder bath, excess solder drains and solder joints remain which attach the component leads to the PWB.
Prior to the introduction and promotion of the wave soldering technique, drag soldering was a popular means for soldering PWBs. Wave soldering has became a more popular soldering technique because in most instances the wave soldering technique minimizes defects such as bridging and excess solder on the bottom side of the PWB. However, recent modifications in PWB design and the addition of heat sinks have caused wave soldering techniques to be inadequate for heat transfer for these PWBs.
With technological advances the thickness of the PWB has become an important design factor because as new condensed electrical components become available the need to develop more densely populated PWBs emerges. This dense population of circuitry causes higher operating temperatures of the PWB whicn in turn demands the addition of heat sinks to the PWB design. Furthermore, this increased circuit density requires multilayer PWBs to provide enough circuit paths for the components to properly communicate with other components on the PWB. This results in a thicker PWB having a greater thermal mass, thereby exceeding the capability of the wave soldering technique to uniformly heat the PWB.
Using a wave soldering machine on thick PWBs is inadequate because of nonuniform heating across the length of the board caused by the wave soldering technique. Specifically, while the cold leading edge of the PWB requires a greater heat transfer rate from the solder wave to raise the leading edge to a minimum temperature, this same heat transfer rate causes the trailing edge of the PWB to overheat. The high rate of heat transfer causes the portion of the PWB approaching the solder wave to accumulate heat through heat conduction before it actually contacts the solder wave. Consequently, as the PWB passes over the solder wave the PWB portion which has already been substantially heated from previous heat conduction now passes over the solder wave and receives additional and excessive heating from the solder wave. Overheating the PWB during the solder process is unacceptable and subsequently wave soldering of thick PWBs is not acceptable. This is particularly a problem with thick PWBs and printed wiring assemblies with heat sinks since longer contact periods with the solder wave permit more extensive heat transfer.
On the other hand, the drag soldering technique permits the entire length of the PWB to dwell in the heated solder for a fixed period. This permits a relatively uniform heating of the PWB across its entire length, which is especially advantageous to the soldering of thick PWBs. Furthermore, a drag soldering machine generally is much less complex than a wave soldering machine and consequently maintenance costs are much less. Ideally for the soldering of electronic components to a thick PWB, the uniform heating of the drag soldering technique is desirable but the problem of defects caused by bridging and excess solder must be solved.
An object of this invention is to provide a solution to the current problem of drag solder defects caused by bridging and excess solder on the PWB.
FIG. 1 illustrates a schematic of a drag soldering machine. A PWB 2 with electronic components 4 in place enters the drag solder machine along a linear entry guide 6 and is moved along a drag guide 8 over the surface 10 of a molten solder bath 12. The PWB 2 is then removed from the solder bath 12 along a linear exit guide 14. The PWB 2 is moved in and out of the solder bath 12 using a transport means 16, which may consist of a motor-driven chain (not shown) that pulls a pallet (not shown) into which the PWB 2 would be placed. Note that in actuality the PWB is placed in a pallet and it is the pallet that is guided. For simplicity the PWB will be exactly the length of the pallet such that when the pallet enters and leaves the solder bath, the PWB will do so simultaneously. For this reason the PWB will be discussed without reference to the pallet. In actuality the pallet will probably be longer than the PWB.
In drag soldering a significant factor effecting the quantity of solder remaining on the solder joints and the PWB and a significant factor also effecting bridging, in which solder bridges between two terminals, is the vertical velocity of the PWB as it separates from the solder in the solder bath. This vertical velocity is also known as the peel-out velocity of the PWB with respect to the solder bath since this motion causes the PWB to separate, or peel, from the solder bath. A high vertical velocity leaves a large quantity of solder on the PWB, while a low velocity leaves a lesser quantity of solder on the PWB. A high vertical velocity also creates more bridging. Control of this influential vertical velocity has not been accomplished on existing drag soldering machines.
A more detailed sketch of a typical drag soldering machine exit guide is shown in FIG. 2. Typically, the linear exit guide 14 consists of a linear ramp oriented at an angle of approximately 13 degrees from the horizontal plane created by the solder bath surface 10 (see FIG. 1). This feature is highlighted in FIG. 2, which shows the PWB 2 in three positions. Position 18 shows the PWB on the drag guide 8. Position 20 shows the PWB 2 in transition between the drag guide 8 and the linear exit guide 14. Position 22 shows the PWB 2 on the linear exit guide 14. The vertical velocity of the PWB 2 as it leaves the solder bath depends on the velocity at which the PWB 2 moves across the drag guide 8 onto the linear exit guide 14 and the contour of the linear exit guide 14. Ideally, the vertical velocity at the point of separation of the PWB 2 from the solder of the solder bath should be constant across the length of the PWB 2. Since the actual point of separation of the PWB from the solder bath is strictly a function of the distance between the PWB and the solder bath and typically this distance is about 1/8", the critical vertical velocity is that velocity occurring at the portion of the PWB that is 1/8" from the solder bath. Note that this separation distance of about 1/8" is a function of the solder and the temperature of the solder. For simplicity and as an approximation, the vertical velocity of the PWB at the instant the PWB leaves the solder bath, not when the PWB is a 1/8" distance from the solder bath, will be used in this discussion.
Defining a leading edge 24, a middle point 26 and a trailing edge 28 on the PWB 2, it can be shown that the vertical velocity of the PWB from the solder bath for the configuration shown in FIG. 2, which is typical of existing drag soldering machines, is not constant. Once the PWB 2 passes a transition point 30 between the drag guide 8 and the linear exit guide 14, separation between the PWB 2 and the solder bath begins. Given a velocity V of the PWB 2 parallel to the linear exit guide 14, when the leading edge 24 of the PWB 2 passes the point 30 of transition, the vertical velocity increases from zero to V sin θ, where θ in this instance is equal to 13°, while the vertical velocity of the trailing edge 28 remains at zero. From the time the leading edge 24 passes the transition point 30, until the trailing edge 28 passes the transition point 30, the vertical velocity of any intermediate point, including the midpoint 26, may range in speed between zero and V×sin θ. The result of this is that the vertical velocity at the point of separation of the PWB 2 from the solder bath changes across the length of the PWB. The velocity of those points on the PWB closest to the leading edge 24 is much higher than that of those points closer to the trailing edge 28. Relating this to the drag soldering process, a larger quantity of solder is left deposited on those points of the PWB closer to the leading edge 24 than on those points closer to the trailing edge 26 since as mentioned earlier a high speed of withdrawal leaves a large quantity of solder on the PWB. This larger quantity of solder is the major cause of bridging on the PWB.
FIG. 3 is a graph which illustrates the fraction of the PWB which separates from the solder bath as the PWB is moved from the drag guide to the linear exit guide. FIG. 3 actually shows the location of the point of separation of the solder from the surface of the PWB. As mentioned earlier, this occurs when the PWB is about 1/8" above the solder bath. As the PWB begins to travel along the linear exit guide the distance between the board and the solder bath increases until the leading edge of the board is a vertical distance of about 1/8" from the solder bath. At this point the leading edge of the PWB breaks away from the solder. As the board continues to travel from the drag guide to the linear exit guide, the portion of the PWB that becomes separated from the solder bath increases rapidly. FIG. 3 illustrates that when the PWB has travelled about 20% of its length, 80% of the PWB has separated from the solder bath. Similarly, the vertical velocity of the point of separation in this region is very high which causes excessive amounts of solder to be deposited across the leading section the PWB. Furthermore, only 20% of the PWB is drained during the remaining 80% of the PWB travel onto the exit guide which necessarily indicates a relatively slow vertical velocity at the point of separation for 80% of the PWB. Ideally the PWB should be withdrawn from the solder bath so that a uniform vertical velocity exists across the length of the PWB at the point of separation between the PWB and the solder bath.
It is an object of this invention to provide a means by which a printed wiring board may be separated from a solder bath such that a uniform vertical velocity exists across the distance of the PWB at the point of separation between the PWB and the solder bath resulting in approximately equal amounts of solder deposited across the length of the PWB.
SUMMARY OF THE INVENTION
The invention is an improved drag soldering machine for printed wiring boards (PWB) for providing a uniform vertical velocity at the point of separation between the solder and the PWBs. The improved drag soldering machine has a molten solder bath, an entry guide for directing the PWB to a horizontal position partially submerged in the solder bath, a drag guide for horizontally directing the PWB across the solder bath, an exit guide for separating the PWB from the solder bath by directing the PWB up and away from the solder bath and a transport means for advancing the PWB in the guide means, wherein the improvement comprises an exit guide providing an approximately uniform vertical velocity at the point of separation between the PWB and the solder bath thereby promoting a uniform solder distribution over the length of the PWB.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is prior art and shows a schematic of a typical drag soldering system.
FIG. 2 is prior art and is a sketch showing the movement of a PWB on a typical drag soldering machine from a position submerged in the solder bath to a position in which the PWB has separated from the solder in the solder bath.
FIG. 3 shows a graph illustrating the portion of the PWB separated from the solder in the solder bath as a function of the horizontal displacement of the PWB on a typical drag soldering machine.
FIG. 4 shows a schematic of a drag soldering system with the improvement of this invention.
FIG. 5 shows the movement of the PWB using the improvement of this invention.
FIG. 6 shows the portion of the PWB separated from the solder in the solder bath as a function of the horizontal displacement of the PWB on a modified drag soldering machine utilizing the improvement of this invention.
FIGS. 7(A) and 7(B) show two positions used to graphically generate an optimum curve for the exit guide.
FIG. 8 shows a typical adaptation of a drag soldering machine incorporating the improved exit guide.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention is a modification to the exit guide on a drag soldering machine whereby approximately a uniform vertical velocity is provided between the printed wiring board and the solder bath at the point of separation of the PWB from the solder bath. The schematic of the modified drag soldering machine shown in FIG. 4 illustrates the invention. Note this schematic is identical to that shown in FIG. 1, except Item 6 in FIG. 1 the linear entry guide, and Item 14, the linear exit guide, have both been modified. While one embodiment of this invention involves modifying only the exit guide 14, another embodiment involves modifying both the entry guide 6 and the exit guide 14.
In FIG. 4 the PWB 2 is moved across the drag guide 8 by a transport means 16 over the surface 10 of the solder bath 12 onto a curvilinear exit guide 15. Unlike FIG. 1, the curvilinear exit guide 15 provides a nonlinear contour of which the PWB 2 follows. Looking further at the exit guide details, FIG. 5 is similar to FIG. 2 except that it shows the travel of a PWB 2 over the curvilinear exit guide 15. FIG. 5 shows three positions 18, 20, 22 of the PWB having a leading edge 24, a middle point 26, and a trailing edge 2B. Unlike the linear exit guide found in FIG. 2, the curvilinear exit guide 15 in FIG. 5 provides for a much more uniform vertical velocity at the point of separation 30 of the PWBs from the solder bath. Furthermore, just as in FIG. 3, FIG. 6 approximately illustrates the results of using the curvilinear exit guide by showing the portion of the PWB separated from the solder bath as a function of the distance the PWB is advanced along the drag guide via the transport means. Note that unlike FIG. 3, the curve in FIG. 6 is much closer to a straight line. This indicates that as the PWB travels from the drag guide to the curvilinear exit guide the portion of the PWB that becomes separated from the solder bath increases in a relatively uniform manner. When the PWB has travelled about 20% of its length along the curvilinear exit guide, only approximately 20% of the PWB has separated from the solder in the solder baths. Similarly, this indicates the vertical velocity at the point of separation is relatively uniform and consequently relatively equal amounts of solder will be deposited across the length of the PWB.
The contour of the curve ued as the exit guide is designed to provide for an approximately uniform vertical velocity at the point of separation across the length of the PWB. As an approximation for calculating the contour of a curve which would provide this constant vertical velocity, a curve was developed by which the separation distance, that is the vertical distance between the bottom of the PWB and the top of the solder bath at which the PWB separates from the solder, would occur at a fixed point along the drag solder machine guide. This may be graphically simulated by using a calibrated 8 inch ruler placed on its side with the far right end of the ruler resting on a vertical shim having a specific height. The length of the ruler may be any length corresponding to the length of the associated PWB. Note in actuality the PWB will rest in a pallet and the pallet will be transported along the guides but, for clarity, only the PWB will be discussed. While the ruler represents the PWB, the shim would represent the fixed and predetermined vertical separation distance. As an example, allow the shim height to be 1/8 inch which represents the vertical separation distance between the PWB and the solder bath at which separation initially occurs. The coordinates of the curve will be defined by the location of the right end of the ruler, with x identifying the distance of the ruler along the horizontal direction and y identifying the distance above the solder bath in the vertical direction. The right end of the ruler represents the leading edge of the PWB as it leaves the drag guide and begins ascending along the exit guide. FIG. 7A shows a ruler 40 with its left end resting on a flat surface 42 and its right end resting on a vertical shim 44. At this position the x coordinate is 0 and the y coordinate is the height of the right end of the ruler which is the height of the shim 44. To generate the curve the ruler 40, still on its side, is moved across the shim 44 a distance of 1 inch characterizing a 1 inch movement of the PWB along the exit guide. At this point x equals 1 inch and y would equal the vertical distance the right end of the ruler has moved from its original position. Proceeding to move the ruler at 1 inch increments to the right and recording the associated vertical distance the right end of the ruler has moved from its original position, a collection of data points may be acquired. FIG. 7B shows the ruler 40 moved a horizontal distance x along the flat surface 42 such that the right end of the ruler has moved upward and y' is now a distance from the flat surface 42. It can been seen that as the ruler 42 moves further and further to the right the y coordinate will continue to increase. Using an 8 inch ruler and a 1/8 inch vertical shim, Table 1 found below was constructed.
TABLE 1______________________________________x 0 .5 1.0 2.0 3.0 4.0 5.0 6.0 7.0 7.5______________________________________y .12 .13 .14 .17 .20 .25 .33 .50 1.00 1.94______________________________________
Table 1 provides coordinates to generate a curve to be used as an exit guide that will permit the solder bath to separate from the bottom of the PWB at the same location along the exit guide throughout the travel of the PWB across the solder bath. Consequently, this provides for a vertical velocity across the length of the PWB that is approximately uniform.
The data for the curve found in Table 1 was derived exclusively for a PWB having a length of 8", although improved results over the linear exit guide would exist for other than PWBs having a length of 8". For an optimum curve the proportions of the curve in Table 1 are applicable to a PWB of any length. The x and y coordinates of Table 1 are for a PWB having a length of 8" but the curve coordinates may be increased or decreased by the ratio of the desired PWB length to that of the PWB length. In this manner an exit guide for a PWB having a length of 12" could be designed merely by multiplying the values of the coordinates in Table 1 by a factor of 12/8 or 1.5.
While this curve is one geometry that provides an approximately uniform vertical velocity for a PWB with a length of 8", any curve that provides an approximately uniform vertical velocity would be an improvement over the current linear exit guide. For this reason, while a series of points defining a line is provided, the invention should not be limited to such a configuration. Finally, note that in order to insure that all parts of the PWB reside in the solder bath for an equal amount of time, one embodiment of this invention would require that a curvilinear entry guide means 7, as seen in FIG. 4, be designed to follow the same contour as the curvilinear exit guide 15.
Existing drag soldering machines may be modified to incorporate the modified curvilinear exit guide. FIG. 8 shows a typical adaptation to a machine already using a linear exit guide 14 having an angle of approximately 13° measured from the horizontal. A section 50 (shown by dotted lines) of the existing linear exit guide which begins at the end of the drag guide 51 at point 52 must be removed and replaced with the modified exit guide. The modified exit guide must first direct the PWB (not shown) to a vertical distance sufficient to begin separation of the PWB from the solder in the solder bath. A vertical distance of 1/8" will be used but, as implied earlier this distance is a function of the solder and the solder temperature. The geometry of an initial segment 53 ending at point 54 used to raise the PWB 1/8" is not critical but should provide a smooth transition (i.e. raise the PWB 1/8" along a 1/2" initial segment 53 of the exit guide). Once the exit guide has raised the PWB to a vertical distance of 1/8", then beginning at point 54 the contour of an intermediate section 56 is defined by the curve in Table 1, or any proportional curve that provides an approximately uniform vertical velocity, should be followed to a point 58 just before the intersection of the modified curve with the path of the linear exit guide 14. A smooth transitional final segment 62 must be formed to link the curve defined in the intermediate section 56 with the remainder of the linear exit guide 14 still in place on the drag soldering machine. Note again that Table 1 data pplies for a PWB having a length of 8" and that other proportional curves would be optimum for PWBs having different lengths.
As mentioned earlier, the linear entry guide of drag soldering machines may also be modified to incorporate a modified entry curve. This is shown by item 7 in FIG. 4. This would be done in the same manner in which the exit guide is modified. Using two similar curves for the entry guide and the exit guide insures the residency time in the solder bath of each part of the PWB will be equal.
Although this invention has been described with reference to a specific embodiment thereof, numerous modifications are possible without departing from the invention, and it is desirable to cover all modifications falling within the spirit and scope of this invention.
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The invention is an improved drag soldering machine for printed wiring boards (PWB) for providing a uniform vertical velocity at the point of separation between the solder and the PWBs. The improved drag soldering machine has a molten solder bath, an entry guide for directing the PWB to a horizontal position partially submerged in the solder bath, a drag guide for horizontally directing the PWB across the solder bath, an exit guide for separating the PWB from the solder bath by directing the PWB up and away from the solder bath and a transport means for advancing the PWB in the guide means, wherein the improvement comprises an exit guide providing an approximately uniform vertical velocity at the point of separation between the PWB and the solder bath thereby promoting a uniform soleder distribution over the length of the PWB.
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One of several synthetic procedures available for one-carbon homologation of monosaccharides is the addition of the elements of HCN to aldehydes to afford, generally, an epimeric pair of cyanohydrins, with subsequent reduction of the nitrile group of the latter under conditions where the formed imine is concurrently hydrolyzed to its corresponding aldose, as shown by the equation,
--CHO+HCN→--CHOHCN→--CHOHCHO
Recently we have shown in U.S. Pat. No. 4,581,447 that this approach provides an effective entry into the family of L-sugars, although several aspects of the synthesis required new developments before commercial feasibility became a reality.
The transformation of the intermediate cyanohydrin to its corresponding aldehyde is a curious one involving two consecutive reactions and requiring quite high discrimination among several reaction pathways. What is required is the reduction of the nitrile group to an imine followed by rapid hydrolysis of the imine to its corresponding aldehyde with minimal hydrogenation of the imine to its amine and of the aldehyde to its alcohol. ##STR1##
In the context of competing reactions the requirements for selectivity are that k i >>k a , k h >>k a [H 2 ], and assuming that hydrogenation of the nitrile is the rate limiting step in the above sequence, that k r <<k i . These requirements place a heavy burden on the catalyst used in selective hydrogenation-hydrolysis of cyanohydrins, but even these requirements are augmented by the need for the catalyst to be active at relatively low reaction temperatures (since the cyanohydrins are not particularly thermostable), by the need for the catalyst to be relatively resistant to poisoning by nitrogen-containing organic materials, and by the need for the catalyst to be hydrothermally stable at the low pH required for this transformation.
Previously these needs and requirements have been met, virtually uniquely, by a catalyst of zerovalent palladium supported on barium sulfate. As a zerovalent metal active at low temperatures in the reduction of nitriles, palladium is relatively resistant to poisoning by organic nitrogen-containing compounds, especially amines. By working in a restricted pH range and under hydrogen-poor conditions it was possible to favor hydrolysis of the imine to the aldehyde, and to limit amine formation via reduction of the imine. By performing the reaction over a limited temperature range it was possible to minimize the decomposition of reactants so as to give a process yielding the desired product aldehyde at commercially acceptable levels; see U.S. Pat. No. 4,581,447. More recently we have described catalysts which, compared to palladium on barium sulfate, are both more resistant to poisoning and more selective in hydrogenation. Although this development led to a further reduction in amine formation, amines remained a significant byproduct. Total elimination of amine formation remained a high priority whose accomplishment eluded us.
During the course of an investigation into the hydrogenation of a mixture of glucocyanohydrin and mannocyanohydrin we experienced poor product balance under certain reaction conditions. Although reactant cyanohydrins were being consumed, inadequate glucose and mannose was produced based on the amount of cyanohydrin which disappeared. Further investigation demonstrated that glucose and mannose was formed in the reaction mixture long after hydrogenation was completed, as if the reaction mixture contained a stable precursor which reacted slowly to give glucose and mannose. After further investigation the following was postulated as the relevant reaction path. ##STR2## What attached special importance to the foregoing was the observation that under conditions where glucose and mannose were formed long after hydrogenation had ceased, virtually no amine was formed; amine product formation had for all practical purposes been eliminated.
The sequence above predicts that if hydrogenation is performed under sufficiently acidic conditions, all of the formed imine would be "trapped" as the protonated pyranosyl amine, and no glucose or mannose would be formed during hydrogenation. Indeed, subsequent experiments verified this prediction. But what was particularly striking was the absence of amine produced during hydrogenation which implied that the pyranosyl amine was quite resistant to further hydrogenation. Recalling that a hexose such as glucose can be readily reduced because of the equilibrium between the pyranose and open chain form, it could be expected that equilibrium between the pyranose and the open chain form of the imine, whether or not protonated, also would lead to amine via reduction of the imine. This is not the case, and whatever may be its reason the virtual elimination of amine as a hydrogenation product certainly is unprecedented. In his study of the mutarotation, hydrolysis, and rearrangement reactions of glycosylamines Isbell and coworkers noted that glycosylamine hydrolysis rates were very low in strongly acidic solutions, and postulated that the presence of a general base was necessary for hydrolysis via the open chain immonium ion. See H. S. Isbell and H. L. Frush, J. Org. Chem., 23, 1309 (1958) and references cited therein. However stable the protonated pyranosyl (or furanosyl) amine may be at low pH, it is not clear how this is related, if at all, to the equilibrium between these ring forms and the open chain immonium ion.
Our observation also led to a method of selectively converting cyanohydrins to aldehydes with more than 95 percent exclusion of amine as a concurrent reaction product. The process which is our invention reduces cyanohydrins under conditions of high acidity where the intermediate imine is unreactive both as to further hydrogenation and as to hydrolysis. After hydrogenation of the cyanohydrin is complete, the reaction mixture is separated from both the hydrogenation catalyst and hydrogen. When acid is removed from the reaction mixture the imine hydrolyzes to the corresponding aldehyde which is then recovered as the desired product of one-carbon homologation of monosaccharides.
SUMMARY OF THE INVENTION
The purpose of our invention is to selectively convert cyanohydrins which are the HCN adducts of aldotetroses, aldopentoses, and aldohexoses to their corresponding aldehydes with high selectivity and with the virtual elimination of amine as the byproduct. An embodiment is the hydrogenation of aqueous solutions of cyanohydrins under sufficiently acidic conditions to stabilize the formed imine, separating the aqueous solution of the imine, and hydrolyzing it in the absence of hydrogen to its aldehyde(s). In a more specific embodiment the aqueous solution contains at least 1.4 equivalents of a strong acid relative to the cyanohydrin. In a still more specific embodiment the aqueous solution which is hydrogenated contains at least about 8 weight percent sulfuric acid.
DESCRIPTION OF THE FIGURE
FIG. 1 shows the dependence of glucose plus mannose, imine, and amine concentration on sulfuric acid concentration in hydrogenation at 23° C., 600 psig H 2 .
DESCRIPTION OF THE INVENTION
Our invention utilizes a method of selectively hydrogenating cyanohydrins under highly acidic conditions where the resultant imine is stable to both further hydrogenation and to hydrolysis. In our method the intermediate imine, postulated to be stabilized in its protonated pyranose form, is isolated as an aqueous solution and subsequently hydrolyzed in the absence of hydrogen by removal of acid. The result is the formation of aldehydes with largely complete elimination of amine, formed by reduction of the imine, as a byproduct. More specifically, amine is formed in less than about 5 percent theoretical yield. Previously, the selectivity of the conversion of cyanohydrins to their aldehydes by hydrogenation-hydrolysis was quite sensitive to hydrogen pressure, and because selective hydrogenation required hydrogen-poor conditions the prior art methods suffered from low conversion rates. A further benefit accruing from the present method is a greatly reduced sensitivity of the selectivity to reaction conditions, especially hydrogen pressure. In particular, since formation of a stabilized imine and its intrinsic stability is a function largely of acid concentration, hydrogenation can be performed at a much higher pressure than taught in the prior art without adversely affecting the selectivity of cyanohydrin conversion. Another incidental benefit is the elimination of alcohol formation via reduction of the product aldehyde, since in the present method aldehyde is formed in the absence of hydrogen.
Our invention is applicable to cyanohydrins which are the adducts of an aldose and hydrogen cyanide, HCN. Of particular importance are the tetroses, pentoses, and hexoses. Erythrose and threose exemplify the tetroses, while ribose, arabinose, xylose and lyxose exemplify the pentoses. Examples of a hexose include allose, altrose, glucose, mannose, gulose, idose, galactose, and talose. As can be readily appreciated, our process is equally applicable to the D-series of aldoses and the L-series. The cyanohydrins are used as aqueous solutions whose concentration is desirably as high as possible to maximize productivity. In the most usual case the feedstock will contain from about 5 through about 25 weight percent of cyanohydrin. Concentrations as high as 50 weight percent may be feasible; concentrations under 5 weight percent may be used, but generally with lower productivity.
The acidity of the aqueous solution of cyanohydrin used as a feedstock is a key to the success of our invention. In particular, it has been found that for imine stabilization under reaction conditions there is required a strong acid in an amount sufficient to afford at least 1.4 equivalents of acid per mole of cyanohydrin being reduced. By "strong acid" is meant an acid which is considered completely, or virtually completely, dissociated. Examples of strong acids which may be used in our invention include sulfuric acid, phosphoric acid, hydrochloric acid, and trifluoroacetic acid, with sulfuric acid being preferred solely for reasons of convenience. Using sulfuric acid as an example, the requirement of having at least 1.4 equivalents of acid per mole of cyanohydrin requires 0.7 moles of sulfuric acid per mole of cyanohydrin, since sulfuric acid is a diprotic mineral acid. Although there does not appear to be an upper limit to the amount of acid which may be used, when more than about 3 equivalents of acid is used per mole of cyanohydrin there is little, if any, incremental benefit. As a practical matter then, our invention may be practiced within the range from about 1.4 to about 3 equivalents of acid per mole of cyanohydrin. To give a concrete example, using a common stock solution containing 22 weight percent of a mixture of glucocyanohydrin and mannocyanohydrin, a mixture of 92 parts by weight of this stock solution with 8 parts by weight of sulfuric acid affords 1.4 equivalents sulfuric acid per mole of cyanohydrin; using 84.6 parts by weight of the stock solution and 15.4 parts by weight of sulfuric acid affords an aqueous feedstock containing 3 equivalents of sulfuric acid per mole of cyanohydrin mixture.
Since acid concentration is the key to selectivity, the nature of hydrogenation catalysts which may be used in the practice of this invention is less important than in other processes for analogous cyanohydrin conversions. However, since such catalysts are employed in highly acidic aqueous solutions it is apparent that they must be stable under these reaction conditions. The most useful class of catalysts is that of supported zerovalent palladium. Although the classic catalyst of palladium and barium sulfate may be used, a preferred catalyst is that of zerovalent palladium dispersed on a polymeric organic resin having a surface area of at least 30 m 2 /g. The palladium is zerovalent and is neither in a higher oxidation state nor complexed with other ligands. The organic resin on which it is dispersed serves only as a relatively porous physical structure on which zerovalent palladium is more or less uniformly dispersed, but the resin must be stable under the highly acidic conditions under which hydrogenation is performed. Examples of resins which may be successfully used in the practice of this invention include polystyrene, polyacrylamide, and poly(vinylpyridine). Resins bearing strongly acidic functional groups seem to be desirable and may be exemplified by divinylbenzene-crosslinked polystyrene having pendant sulfonic acid groups (available under the trade name XN1010 from Rohm & Haas) and polystyrene having pendant perfluoroalkyl carboxylic acid groups as exemplified by NAFION resins from E. I. DuPont. Among the preferred resins are polystyrenes, especially the polystyrenes with pendant perfluoroalkyl carboxylic acid groups, and polyacrylamides. Resins having a surface area greater than about 50 m 2 /g are preferred, and those with a surface area over about 100 m 2 /g are even more highly preferred.
The hydrogenation of cyanohydrins to the stabilized imine is effected by contacting the acidic aqueous solution of the cyanohydrin with a supported zerovalent palladium catalyst and hydrogen at a pressure up to about 2,000 pounds per square inch and at a temperature from 10 to about 85° C. Although the prior art has necessarily used low hydrogen pressures to effect selective hydrogenation of cyanohydrins, one benefit of our invention is that the selectivity of cyanohydrin hydrogenation is essentially independent of hydrogen pressure, at least up to about 2,000 pounds per square inch. Our invention permits hydrogenation at a much higher pressure than was formerly possible without adversely affecting selectivity and with a substantially higher rate of conversion. Hydrogen pressures between about 100 and about 1500 pounds per square inch are most often used for convenience with the range from 600 to 1000 psig most frequently employed, but it needs to be emphasized that hydrogen pressure is no longer the critical factor as was the case with prior art methods.
Hydrogenation is effected in a range between about 10° and about 85° C., although at temperatures in excess of about 50° C. the cyanohydrins frequently are less stable and undesirable byproducts accompany the major ones. It is for this reason that temperatures are usually held at no more than about 50° C., with reductions usually being carried out in a temperature range between about 20° and about 45° C. But it needs to be recognized that where all reactants and products are stable at temperatures over 50° C. then higher temperatures may be employed without detriment.
When hydrogenation of this cyanohydrin feedstock is complete, the aqueous solution of the resulting stabilized imine product is separated from hydrogen. In practice, hydrogen is vented, replaced first by an inert gas, and catalyst is separated from the aqueous product mixture, as by filtration. However, in principle, subsequent hydrolysis of the imine may not require removal of the catalyst so long as hydrolysis is conducted in the absence of hydrogen. But we emphasize that for practical purposes the stabilized aqueous imine solution is separated both from the hydrogenation catalyst and hydrogen prior to imine hydrolysis.
The stabilized imine in solution is then hydrolyzed by removal of acid. Any method which effects removal of acid can be successfully employed to hydrolyze the imine. Such methods include electrodialysis, neutralization of acid to a pH greater than about 3, precipitation of imine with concurrent hydrolysis of the precipitate, and thermal hydrolysis. For example, removal of salts via electrodialysis effectively drives to completion the hydrolysis of imines to aldehydes. As another example, the hydrolytic liability of imines leads to their rapid hydrolysis at ambient temperature at a pH above about 3. Consequently partial neutralization of the strong acid suffices for complete hydrolysis. It also has been observed that at temperatures above 85° C., and especially above 95° C., the protonated imines hydrolyze even in highly acidic solutions. Consequently the hydrogenation reaction mixture may be simply heated for a short period, typically about 3 hours at 100° C., to effect imine hydrolysis. Finally, the imine salt precipitated from highly acidic aqueous solutions, as with ethanol, undergoes very rapid hydrolysis upon addition of water or exposure to the moisture in air.
The following examples will serve to illustrate this invention and are intended only as representative illustrations of its successful practice. These examples should not be interpreted as limiting our invention in any way, and variants which will be recognized by the skilled worker are intended to be encompassed within our invention.
EXAMPLE 1
Preparation of Standard Cyanohydrin Feedstock. To an Erlenmeyer flask was charged 200 g (0.24 moles) of a 22 weight percent aqueous solution containing a mixture of gluco- and mannocyanohydrins. The flask was cooled in a dry ice bath at -78° C. and to it was slowly added 35.6 g 98 weight percent (cold) H 2 SO 4 (0.36 moles) in 2-3 g portions accompanied by vigorous shaking to mix the contents. After all of the acid was added, the mixture was allowed to reach 23° C. prior to hydrogenation.
Typical Hydrogenation Procedure. To a 100 cc glass liner for use in an 850 cc rotating bomb was charged 20 g feed (15 weight percent acid stabilized) and 0.5 g of a catalyst containing 4 weight percent zerovalent palladium on a washed polystyrene support (XAD-4 from Rohm and Haas). The bomb was flushed with nitrogen then charged to 500-1000 psig with hydrogen. Hydrogenation proceeded at 35° C. for 3-10 hours. The bomb was cooled, vented and flushed with nitrogen and the reaction mixture was filtered through Whatman #41 filter paper to remove catalyst. The filtrate was analyzed by ion chromatography (IC), 13 C NMR and HPLC for sugars, cyanohydrins, acids, amides and lactones.
EXAMPLE 2
Effect of Acid Concentration and Pressure on Hydrogenation. Aqueous solutions of a mixture of mannocyanohydrin and glucocyanohydrin feedstock (21-2 weight percent cyanohydrin) containing variable amounts of sulfuric acid were hydrogenated in a rotating autoclave at differing pressures at 23° C. using as a catalyst 2.5 weight percent of a composite having 4 weight percent zerovalent palladium dispersed on XAD-4 resin (see Example 1). Results are summarized below in Tables 1 and 2 and in FIG. 1.
TABLE 1__________________________________________________________________________Effect of Pressure and Acid Concentrationon Cyanohydrin HydrogenationAcid weight relative HydrogenRun.sup.c percent equivalents.sup.a Pressure, psig Cyanohydrin.sup.b Glucose/Mannose.sup.b Imine.sup.b Amine.sup.b__________________________________________________________________________1 5 0.9 600 0 80 34 122 10 1.8 600 1 5 90 13 15 2.9 600 0 0 100 04 8 1.4 60 0 0 100 05 8 1.4 200 5 5 97 16 8 1.4 1000 0 0 100 3__________________________________________________________________________ .sup.a Number of equivalents acid per equivalent cyanohydrin in feed. .sup.b All analysis were performed by .sup.13 CNMR. Numbers refer to relative intensities of the C1 signal normalized relative to the imine peak in run 4 which was arbitrarily assigned a value of 100. .sup.c Hydrogenation time: runs 1-3, 7 hours; runs 4-6, 3 hours.
TABLE 2__________________________________________________________________________Effect of Sulfuric Acid Concentration on Imine Stability in CyanohydrinHydrogenation (600 psig, 23° C.)Weight % Weight Percent.sup.a Peak Areas by .sup.13 C-NMR.sup.bRun Acid Glucose Cyano. Mannose Amine Imine Mannose/Glucose__________________________________________________________________________1 .sup. 0.sup.c 0.49 3.9 0.06 0 8 02 5 1.7 6.5 5.8 12 34 803 10 0.34 3.3 1.4 1 90 5 (5.1).sup.c (2.5).sup.c (8.7).sup.c 0.5.sup.c .sup. 0.sup.c 100.sup.c4 15 0.16 2.5 0.88 0 100 0__________________________________________________________________________ .sup.a By ion chromatography .sup.b See footnote b, Table 1 .sup.c After hydrolysis of mixture by partial neutralization to pH 4.
These results show that imine is stabilized at acid concentrations affording 1.4 equivalents acid per equivalent cyanohydrin with virtually no amine formed during hydrogenation. The data also point to imine (as its salt) as virtually the sole product at pressures of 60-1000 psig; i.e., catalyst selectivity is independent of pressure at high acid concentrations.
EXAMPLE 3
Effect of Specific Acids on Hydrogenation. Using the feedstock and hydrogenation catalyst of Example 2, hydrogenations were performed at 35° C., 60 psig, for 3 hours in the presence of 15 weight percent of different acids with the results given in Table 3. It is clear from the data that best results are obtained using sulfuric acid.
TABLE 3__________________________________________________________________________Stabilization of Imines During HydrogenationWeight Percent (ion chromatography) Peak Areas by .sup.13 C-NMR.sup.aAcid Glucose Cyanohydrin Mannose Amine Imine Glucose + Mannose__________________________________________________________________________H.sub.2 SO.sub.4 0.2 0.3 0.7 0 98 0H.sub.3 PO.sub.4 0.8 0.4 2.7 3 42 33HAc 2.2 0.3 6.1 23 86 23__________________________________________________________________________ .sup.a See footnote b, Table 1.
EXAMPLE 4
Hydrolysis of Imine by Electrodialysis. Twenty-five grams of 22 wt. % stabilized glucose/mannose imine solution containing 15 weight percent sulfuric acid was diluted with 35 g of water. The conductivity of this solution was 190 ms/cm. This solution was fed into an electrodialysis unit and treated over the course of 5 hours. After 2.5 hours an additional 10 g of water was added to compensate for losses. When the solution conductivity reached 22 ms/cm the waste salt stream was replaced with fresh water in order to drive the electrodialysis to lower conductivity. The procedure continued until the conductivity of the product (imine containing) solution reached 0.2 ms/cm at the end of 5 hours of total treatment time.
The solution recovered contained upon analysis by HPLC 1.37 g of L-glucose and 4.62 g of L-mannose. No imine was detected by 13 C-NMR; during the electrodialysis procedure all of the imine had been hydrolyzed to L-glucose, L-mannose.
Thermal Hydrolysis of Imines. To a rotating autoclave glass liner was charged 10 g of a filtered, catalyst free imine feedstock. The liner was charged to a rotating autoclave and was flushed with nitrogen. It was then pressured to 1000 psig with nitrogen and the contents heated at temperature (35° C.>100° C. range) for 3 hours.
Hydrolysis of Imine by Precipitation in Ethanol. Two g of a filtered imine solution resulting from hydrogenation of a standard cyanohydrin feedstock (21.4 weight percent imine) was added dropwise to 10 g of cold ethanol at 10° C. A total of 0.73 g (96 weight percent) of precipitate was collected (0.43 g imine and 0.3 g reaction salts) by filtration and washed with cold ethanol. When distilled water was added to the precipitate the imine dissolved and hydrolyzed. The imine is hydroscopic and will undergo spontaneous hydrolysis.
Hydrolysis of Imine by pH Adjustment with Base. 10 g of a filtered imine solution resulting from hydrogenation of a standard cyanohydrin feed (˜20-24 weight percent imine) was charged to an Erlenmeyer flask placed in an ice bath at 0° to 10° C. A stock solution of sodium hydroxide (10-20 weight percent) was prepared and also cooled. The sodium hydroxide solution was slowly added dropwise with stirring to the Erlenmeyer to give a solution with pH=4-5. The solution turned to a slight clear yellow tint and sodium chloride precipitated. The NaCl can be filtered off to afford a solution of the resulting glucose/mannose mixture.
EXAMPLE 5
Continuous Fixed Bed Hydrogenation of Cyanohydrin. Nineteen grams of a catalyst composed of 4% zerovalent palladium on polystyrene (XAD-4 from Rhom & Haas, surface area 725 m 2 /g) may be used as a fixed bed for the hydrogenation of a feedstock containing 24 weight per cent aqueous epimeric cyanohydrins. To the feedstock, previously adjusted to pH 2.0, may be added sulfuric acid to a ratio of 2.9:1 equivalents. The reactor may be run at 1000 psig hydrogen at a bed temperature of 30° C., and feed flow rate of 10 cc/hr in an upflow mode. Cyanohydrin conversion of 90% may be obtained with 75% selectivity to the imine with little aldose or amine product formed.
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There is described a method of selectively and continuously converting a cyanohydrin to its corresponding aldehyde using as a catalyst zerovalent palladium dispersed on an organic polymeric resin with a surface area above 30 m 2 /g under highly acidic conditions where the formed imine is resistant to further reduction to the amine. Where the aqueous cyanohydrin feedstock contains more than 1.4 equivalent proportions of a strong acid, less than 5% of the theoretical yield of amine is formed. Hydrogenation may be performed at a pressure as great as 2000 psig without significant deleterious effects on selectivity. Hydrolysis of the hydrogenation product affords the corresponding aldehydes in good yields.
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[0001] This application claims priority from U.S. provisional application Ser. No. 60/189,704, filed Mar. 15, 2000.
FIELD OF THE INVENTION
[0002] The present invention relates to an improved process for preparing 4-substituted resorcinol derivatives.
BACKGROUND OF THE INVENTION
[0003] Resorcinol derivatives are known to be useful for a variety of purposes. For example, in the cosmetic field, resorcinol derivatives have been used as skin lightening agents. The use of resorcinol derivatives as skin lightening agents is described in European Patent Application EP 904,774, published Mar. 31, 1999; U.S. Pat. No. 5,468,472, issued Nov. 21, 1995; U.S. Pat. No. 5,399,785, issued Mar. 21, 1995; European Patent Application EP 623,339, published Nov. 9, 1994; JP 5-4905, published Jan. 14, 1993; and European Patent Application EP 341,664, published Nov. 15, 1989.
[0004] Resorcinol derivatives have also been used as dandruff control agents (JP 4-169516, published Jun. 17, 1992); as anti-acne agents (JP 4-169511, published Jun. 17, 1992); as potentiators of anti-microbial compounds (U.S. Pat. No. 4,474,748, issued Oct. 2, 1984); as anti-browning agents for foods (U.S. Pat. No. 5,304,679, issued Apr. 19, 1994); and in the preparation of photographic dye images (U.S. Pat. No. 3,756, 818, issued Sep. 4, 1973).
[0005] The present invention provides an improved process for preparing 4-substituted resorcinol derivatives. The present invention further provides intermediate compounds useful in preparing such resorcinol derivatives, as well as processes for preparing the intermediate compounds. The improved process of the present invention is easier to use than standard methods for preparing resorcinol derivatives in large quantities. In addition, the improved process of the present invention results in a higher yield of final product than standard methods.
SUMMARY OF INVENTION
[0006] The invention provides a process for preparing a resorcinol derivative of formula l:
or a pharmaceutically acceptable salt thereof, wherein the dashed line indicates an optional double bond at that position, and wherein X and Y are each independently selected from hydrogen, (C 1 -C 12 )alkyl, (C 2 -C 12 )alkenyl, (C 2 -C 12 )alkynyl, or X and Y are taken together with the carbon to which they are attached to form a (C 4 -C 8 )cycloalkyl ring or (C 5 -C 8 )cycloalkenyl ring, provided that the (C 4 -C 8 )cycloalkyl ring or (C 5 -C 8 )cycloalkenyl ring is not aromatic; which (C 1 -C 12 )alkyl, (C 2 -C 12 )alkenyl, (C 2 -C 12 )alkynyl, (C 4 -C 8 )cycloalkyl ring or (C 5 -C 8 )cycloalkenyl ring is optionally substituted by one to three independently selected groups Z, wherein Z is any substituent capable of being substituted thereon where the process of the present invention can be used to prepare the particular substituted resorcinol derivative.
[0007] In a preferred embodiment, Z is selected from the group consisting of cyano; halo; (C 1 -C 6 )alkyl; aryl; (C 2 -C 9 )heterocycloalkyl; (C 2 -C 6 )heteroaryl; aryl(C 1 -C 6 )alkyl-; ═O; ═CHO(C 1 -C 6 )alkyl; amino; hydroxy; (C 1 -C 6 )alkoxy; aryl(C 1 -C 6 )alkoxy-; (C 1 -C 6 )acyl; (C 1 -C 6 )alkylamino-; aryl(C 1 -C 6 )alkylamino-; amino(C 1 -C 6 )alkyl-; (C 1 -C 6 )alkoxy-CO—NH—; (C 1 -C 6 )alkylamino-CO—; (C 2 -C 6 )alkenyl; (C 2 -C 6 )alkynyl; hydroxy(C 1 -C 6 )alkyl-; (C 1 -C 6 )alkoxy(C -C 6 )alkyl-; (C 1 -C 6 )acyloxy(C 1 -C 6 )alkyl-; nitro; cyano(C 1 -C 6 )alkyl-; halo(C 1 -C 6 )alkyl-; nitro(C 1 -C 6 )alkyl-; trifluoromethyl; trifluoromethyl(C 1 -C 6 )alkyl-; (C 1 -C 6 )acylamino-; (C 1 -C 6 )acylamino(C 1 -C 6 )alkyl-; (C 1 -C 6 )alkoxy(C 1 -C 6 )acylamino-; amino(C 1 -C 6 )acyl-; amino(C 1 -C 6 )acyl(C 1 -C 6 )alkyl-; (C 1 -C 6 )alkylamino(C 1 -C 6 )acyl-; ((C 1 -C 6 )alkyl) 2 amino(C 1 -C 6 )acyl-; —CO 2 R 2 ; —(C 1 -C 6 )alkyl-CO 2 R 2 ; —C(O)N(R 2 ) 2 ; —(C 1 -C 6 )alkyl-C(O)N(R 2 ) 2 ; R 2 ON═; R 2 ON═(C 1 -C 6 )alkyl-; R 2 ON═CR 2 (C 1 -C 6 )alkyl-; —NR 2 (OR 2 ); —(C 1 -C 6 )alkyl-NR 2 (OR 2 ); —C(O)(NR 2 OR 2 ); —(C 1 -C 6 )alkyl-C(O)(NR 2 OR 2 ); —S(O) m R 2 ; wherein each R 2 is independently selected from hydrogen, (C 1 -C 6 )alkyl, aryl, or aryl(C 1 -C 6 )alkyl-; R 3 C(O)O—, wherein R 3 is (C 1 -C 6 )alkyl, aryl, or aryl(C 1 -C 6 )alkyl-; R 3 C(O)O—(C 1 -C 6 )alkyl-; R 4 R 5 N—C(O)O—; R 4 R 5 NS(O) 2 —; R 4 R 5 NS(O) 2 (C 1 -C 6 )alkyl-; R 4 S(O) 2 R 5 N—; R 4 S(O) 2 R 5 N(C 1 -C 6 )alkyl-; wherein m is 0, 1 or 2, and R 4 and R 5 are each independently selected from hydrogen or (C 1 -C 6 )alkyl; —C(═NR 6 )(N(R 4 ) 2 ); —(C 1 -C 6 )alkyl-C(═NR 6 )(N(R 4 ) 2 ) wherein R 6 represents OR 2 or R 2 wherein R 2 is defined as above; —OC(O)aryl(C 1 -C 6 )alkyl; —NH(C 1 -C 6 )alkyl; aryl(C 1 -C 6 )alkyl-HN—; and a ketal.
[0008] The present invention also provides various intermediate compounds useful in this process, and methods for making them. Specifically, this invention relates to a process for preparing a compound of formula (6)
wherein W is hydrogen or a protecting group;
wherein X and Y are each independently selected from hydrogen, (C 1 -C 12 )alkyl, (C 2 -C 12 )alkenyl, (C 2 -C 12 )alkynyl, or X and Y are taken together with the carbon to which they are attached to form a (C 4 -C 8 )cycloalkyl ring or (C 5 -C 8 )cycloalkenyl ring, provided that the (C 4 -C 8 )cycloalkyl ring or (C 5 -C 8 )cycloalkenyl ring is not aromatic; and wherein the (C 1 -C 12 )alkyl, (C 2 -C 12 )alkenyl, (C 2 -C 12 )alkynyl, (C 4 -C 8 )cycloalkyl ring or (C 5 -C 8 )cycloalkenyl ring is optionally further substituted by one to three independently selected groups Z, where Z is as defined above; comprising reacting a compound of formula (5)
wherein Q is halo, with a base to form the compound of formula (6). In a preferred embodiment, Q is bromo, iodo or chloro; more preferably Q is bromo or iodo; and most preferably Q is bromo.
[0011] The present invention further provides a process for preparing a compound of formula (7)
wherein W, X and Y are as defined above;
comprising reacting a compound of formula (5)
wherein Q is as defined above, with a base to form the compound of formula (7).
[0013] In a preferred embodiment, the compound of formula (5) is prepared by reacting the compound of formula (4)
wherein W, X and Y are as defined above, with a halogenating agent, wherein the halogen corresponds to Q in the compound of formula (5). In a preferred embodiment, Q is bromo, and the compound of formula (5) is prepared by reacting the compound of formula (4) with a brominating agent such as, e.g., N-bromosuccinimide.
[0014] In a further preferred embodiment, the compound of formula (4) is prepared by reacting a compound of formula (2)
with a compound of formula (3)
wherein W, X and Y are as defined above, in the presence of a base to form the compound of formula (4).
[0015] The present invention further provides a process for preparing a compound of formula (5)
wherein Q, W, X and Y are as defined above, comprising reacting the compound of formula (4)
with a halogenating agent, as described above, to form the compound of formula (5).
[0016] In a preferred embodiment, the compound of formula (4) is prepared by reacting a compound of formula (2)
with a compound of formula (3)
wherein W, X and Y are as defined above, in the presence of a base to form the compound of formula (4).
[0017] The present invention further provides a process for preparing a compound of formula (4)
wherein W, X and Y are as defined above;
comprising reacting a compound of formula (2)
with a compound of formula (3)
in the presence of a base to form the compound of formula (4).
[0019] The present invention further provides a process for preparing a compound of formula I(a)
wherein X and Y are defined as above, comprising:
(a) reacting a compound of formula (5)
wherein Q is halo, W is hydrogen or a protecting group, and X and Y are as defined above, with a base to form a compound of formula (6); and
(b) where W is H, reducing the compound of formula (6) so formed to form the compound of formula I(a); or (c) where W is a protecting group, reducing the compound of formula (6) so formed and removing the protecting group to form the compound of formula I(a).
[0023] In a preferred embodiment, the compound of formula (6) is reduced to form the compound of formula I(a) by reaction with triethysilane in the presence of a Lewis acid, or alternatively by hydrogenation under standard conditions.
[0024] The present invention further provides a process for preparing a compound of formula I(a)
wherein X and Y are as defined above; comprising:
(a) reacting a compound of formula (5)
wherein Q is halo, W is hydrogen or a protecting group, and X and Y are as defined above, with a base to form a compound of formula (7); and
(b) where W is H, hydrogenating the compound of formula (7) so formed to form the compound of formula i(a); or (c) where W is a protecting group, hydrogenating the compound of formula (7) so formed and removing the protecting group to form the compound of formula I(a).
[0028] The present invention further provides a process for preparing a compound of formula I(a)
wherein X and Y are defined as above; comprising:
(a) reacting a compound of formula (5)
wherein Q is halo, W is hydrogen or a protecting group, and X and Y are as defined above, with a base to form a compound of formula (6);
(b) reacting the compound of formula (6) so formed with a base to form a compound of formula (7); and
(c) where W is H, hydrogenating the compound of formula (7) so formed to form the compound of formula I(a); or (d) where W is a protecting group, hydrogenating the compound of formula (7) so formed and removing the protecting group to form the compound of formula I(a).
[0033] The present invention further provides a process for preparing a compound of formula I(a)
wherein X and Y are as defined above; comprising:
(a) reacting a compound of formula (5)
wherein Q is halo, W is hydrogen or a protecting group, and X and Y are as defined above, with a base to form a compound of formula (6);
(b) reacting the compound of formula (6) so formed with a base to form a compound of formula (7); and
(c) where W is H, hydrogenating the compound of formula (7) so formed to form the compound of formula I(a); or d) where W is a protecting group, removing the protecting group from compound (7) so formed to form the compound of formula I(b)
and hydrogenating the compound of formula I(b) so formed to form the compound of formula I(a).
[0038] The present invention further provides a process for preparing a compound of formula I(a)
wherein X and Y are as defined above; comprising:
(a) reacting a compound of formula (5)
wherein Q is halo, W is hydrogen or a protecting group, and X and Y are as defined above, with a base to form a compound of formula (7); and
(b) where W is H, hydrogenating the compound of formula (7) so formed to form the compound of formula I(a); or (c) where W is a protecting group, removing the protecting group from compound (7) so formed to form the compound of formula I(b)
and hydrogenating the compound of formula I(b) so formed to form the compound of formula I(a).
[0042] The present invention further comprises a process for preparing a compound of formula I(b)
wherein X and Y are as defined above; comprising:
(a) reacting a compound of formula (5)
wherein Q is halo, W is hydrogen or a protecting group, and X and Y are as defined above, with a base to form a compound of formula (6);
(b) reacting the compound of formula (6) so formed with a base to form a compound of formula I(b) when W is H, and a compound of formula (7) when W is a protecting group; and
(c) when W is a protecting group, removing the protecting group from the compound of formula (7) so formed to form the compound of formula I(b).
[0046] The present invention further provides a process for preparing a compound of formula I(b)
wherein X and Y are defined as above; comprising:
(a) reacting a compound of formula (5)
wherein Q is halo, W is hydrogen or a protecting group, and X and Y are as defined above, with a base to form a compound of formula I(b) when W is H, and a compound of formula (7) when W is a protecting group; and
(b) when W is a protecting group, removing the protecting group from the compound of formula (7) so formed to form the compound of formula I(b).
[0049] As explained below in the description of Scheme I, where W is H, the compound of formula (5) can exist in equilibrium with the compound of formula (5′) as follows.
where W is H, the compound of formula (5′) may be formed directly from the compound of formula (4). In all of the processes described herein where W is H, where the compound of claim ( 5 ) is utilized, the compound of claim ( 5 ′) can be utilized in its place under the same reaction conditions as recited, e.g., to prepare the compounds of formula (6) or (7). The present invention also provides a process for preparing the compound of formula (5′) by treating the compound of formula (4), where W is H, with a halogenating agent to form the compound of formula (5′).
[0050] The various processes of the present invention, as described above, are incorporated into Scheme 1, shown below.
[0051] In a preferred non-limiting embodiment, X and Y are taken together with the carbon to which they are attached to form a (C 5 -C 8 )cycloalkyl ring or a (C 5 -C 8 )cycloalkenyl ring having the following structure:
wherein n is 0, 1, 2 or 3, where such (C 5 -C 8 )cycloalkyl ring or (C 5 -C 8 )cycloalkenyl ring is optionally substituted, and wherein the dashed line indicates an optional double bond at that position. In a non-limiting embodiment, the (C 5 -C 8 )cycloalkyl ring or (C 5 -C 8 )cycloalkenyl ring is substituted by one to three independently selected groups Z as defined above.
[0052] In a preferred embodiment, X and Y are taken together with the carbon to which they are attached to form a cyclohexyl or cyclohexenyl ring, and most preferably a cyclohexyl ring.
[0053] In a further preferred embodiment, X and Y are taken together with the carbon to which they are attached to form a cyclopentyl or cyclopentenyl ring, and most preferably a cyclopentyl ring.
[0054] In a further preferred embodiment, the (C 5 -C 8 )cycloalkyl ring or (C 5 -C 8 )cycloalkenyl ring is not substituted.
[0055] In a further preferred embodiment, the (C 5 -C 8 )cycloalkyl ring or (C 5 -C 8 )cycloalkenyl ring is monosubstituted. More preferably, X and Y are taken together with the carbon to which they are attached to form a monosubstituted cyclohexyl or monosubstituted cyclopentyl ring.
[0056] In a further preferred embodiment, the (C 5 -C 8 )cycloalkyl ring or (C 5 -C 8 )cycloalkenyl ring is disubstituted. More preferably, X and Y are taken together with the carbon to which they are attached to form a disubstituted cyclohexyl or disubstituted cyclopentyl ring.
[0057] Where X and Y are taken together with the carbon to which they are attached to form a cyclohexyl or cyclohexenyl ring, the ring is preferably substituted at the 3- or 4-position, and more preferably at the 4-position.
[0058] Where X and Y are taken together with the carbon to which they are attached to form a cyclopentyl or cyclopentenyl ring, the ring is preferably substituted at the 3-position.
[0059] In a further preferred embodiment, X and Y are taken together with the carbon to which they are attached to form:
which is substituted with one to three independently selected groups Z as described above;
wherein n is 0, 1, or 2.
[0061] In a further preferred embodiment, n is 0 or 1.
[0062] In a further preferred embodiment, n is 0; and the dashed line represents a double bond at that position.
[0063] In a further preferred embodiment, n is 1.
[0064] In a further preferred embodiment, the ring formed by X and Y taken together with the carbon to which they are attached is substituted by OH, ═O, ═NOH, CH 2 OH or
or a combination thereof.
[0065] In a further preferred embodiment, n is 0; the ring formed by X and Y taken together with the carbon to which they are attached is substituted by ═NOH; and the dashed line represents a double bond at that position.
[0066] In a further preferred embodiment, n is 1; and the ring formed by X and Y taken together with the carbon to which they are attached is substituted by OH, ═O, ═NOH, CH 2 OH, or
or a combination thereof.
[0067] Where Z is a (C 2 -C 9 )heterocycloalkyl substituent, it is preferably a group of the formula:
wherein m is 0, 1 or 2, and
Q is CH, NR 2 , O, S, SO, or SO 2 .
[0069] In a further preferred embodiment, X and Y are taken together with the carbon to which they are attached to form a cyclohexyl, cyclohexenyl, cyclopentyl or cyclopentenyl ring that is monosubstituted with Z selected from the group consisting of OH, R 3 C(O)O—, R 3 C(O)O—(C 1 -C 6 )alkyl-, R 2 ON═, R 2 ON═(C 1 -C 6 )alkyl-, R 2 ON═CR 2 (C 1 -C 6 )alkyl-, —NR 2 (OR 2 ), R 4 S(O) 2 R 5 N—, and R 4 S(O) 2 R 5 N(C 1 -C 6 )alkyl-; wherein R 2 , R 3 , R 4 and R 5 are as defined above.
[0070] In a further preferred embodiment, X and Y are taken together with the carbon to which they are attached to form a cyclohexyl or cyclopentyl ring that is monosubstituted with Z selected from the group consisting of OH, R 3 C(O)O—, R 3 C(O)O—(C 1 -C 6 )alkyl-, R 2 ON═, R 2 ON═(C 1 -C 6 )alkyl-, R 2 ON═CR 2 (C 1 -C 6 )alkyl-, —NR 2 (OR 2 ), R 4 S(O) 2 R 5 N—, and R 4 S(O) 2 R 5 N(C 1 -C 6 )alkyl-; wherein R 2 , R 3 , R 4 and R 5 are as defined above.
[0071] In a further preferred embodiment, Z is OH.
[0072] In a further preferred embodiment, Z is R 3 C(O)O—.
[0073] In a further preferred embodiment, Z is R 3 C(O)O—(C 1 -C 6 )alkyl-.
[0074] In a further preferred embodiment, Z is R 2 ON═, R 2 ON═(C 1 -C 6 )alkyl-, or R 2 ON═CR 2 (C 1 -C 6 )alkyl-.
[0075] In a further preferred embodiment, Z is R 2 ON═.
[0076] In a further preferred embodiment, Z is —NR 2 (OR 2 ).
[0077] In a further preferred embodiment, Z is R 4 S(O) 2 R 5 N—.
[0078] In a further preferred embodiment, Z is R 4 S(O) 2 R 5 N(C 1 -C 6 )alkyl-.
[0079] In a non-limiting embodiment, the process of the present invention can be used to prepare a compound selected from the group consisting of:
4-cyclohexyl resorcinol; 4-cyclopentyl resorcinol; 4-(2,4-dihydroxyphenyl)cyclohexanol; 4-(2,4-Dihydroxyphenyl)cyclohexanone; 4-(2,4-Dihydroxyphenyl)cyclohexanone oxime; O-Methyl-4-(2,4-dihydroxyphenyl)cyclohexanone oxime; O-Benzyl-4-(2,4-dihydroxyphenyl)cyclohexanone oxime; 3-(2,4-dihydroxyphenyl)-2-cyclohexen-1-one; (±)-3-(2,4-Dihydroxyphenyl)cyclohexanone; 3-(2,4-Dihydroxyphenyl)-2-cyclohexen-1-one oxime; (±)-3-(2,4-Dihydroxyphenyl)cyclohexanone oxime; (±)-4-[3-(1-Piperazinyl)cyclohexyl]-1,3-benzenediol; (±)-N-[3-(2,4-Dihydroxyphenyl)cyclohexyl]methanesulfonamide; (±)-4-[3(Hydroxymethyl)cyclohexyl]-1,3-benzenediol; (±)-4-[3-(Hydroxyamino)cyclohexyl]-1,3-benzenediol; cis/trans-4-[4-(Hydroxymethyl)cyclohexyl]-1,3-benzenediol; cis/trans-4-(4-Hydroxy-4-methylcyclohexyl)-1,3-benzenediol; (±)-O-Methyl-3-(2,4-dihydroxyphenyl)cyclohexanone oxime; (±)-3-(2,4-Dihydroxyphenyl-1-methylcyclohexanol; (±)-O-Benzyl-3-(2,4-dihydroxyphenyl)cyclohexanone oxime; 3-(2,4-Dihydroxyphenyl)-2-cyclopentenone oxime; (±)-3-(2,4-Dihydroxyphenyl)cyclopentanone; (±)-3-(2,4-Dihydroxyphenyl)cyclopentanone oxime; 4-(2,4-Dihydroxyphenyl)-3-cyclohexen-1-one; cis/trans-N-(4-(2,4-Dihydroxyphenyl)cyclohexyl]acetamide; cis-N-[4-(2,4-Dihydroxyphenyl)cyclohexyl-1-butanesulfonamide; trans-N-[4-(2,4-Dihydroxyphenyl)cyclohexyl]methanesulfonamide; cis-N-[4-(2,4-Dihydroxyphenyl)cyclohexyl]methanesulfonamide; 4-(4-(4-Hydroxyphenyl)cyclohexyl]-1,3-benzenediol; cis/trans-Methyl[4-(2,4-dihydroxyphenyl)cyclohexyl]acetate; trans-Methyl[4-(2,4-dihydroxyphenyl)cyclohexyl]acetate; cis-Methyl[4-(2,4-dihydroxyphenyl)cyclohexyl]acetate; trans-[4-(2,4-Dihydroxyphenyl)cyclohexyl]acetic acid; cis-[4-(2,4-Dihydroxyphenyl)cyclohexyl]acetic acid; cis/trans-[4-(2,4-Dihydroxyphenyl)cyclohexyl]acetic acid; cis/trans-[4-(2,4-Dihydroxyphenyl)cyclohexyl]acetonitrile; cis/trans-4-[4-(2-Aminoethyl)cyclohexyl]-1,3-benzenediol; (±)-4-(3,3-Difluorocyclohexyl)-1,3-benzenediol; (±)-3-(2,4-Dihydroxyphenyl)cyclohexanecarboxamide; (±)-3-(2,4-Dihydroxyphenyl)-N-hydroxycyclohexanecarboxamide; (±)-3-(2,4-Dihydroxyphenyl)-N-ethylcyclohexanecarboxamide; (±)-4-[3-Hydroxy-3-(hydroxymethyl)cyclohexyl]-1,3-benzenediol; (±)-N-[3-(2,4-dihydroxyphenyl)cyclohexyl]acetamide; trans-4-(2,4-Dihydroxyphenyl)cyclohexyl) 4-(dimethylamino)benzoate; cis/trans-4-(2,4-Dihydroxyphenyl)cyclohexanecarboxylic acid; trans-4-(2,4-Dihydroxyphenyl)cyclohexyl ethylcarbamate; trans-4-(2,4-Dihydroxyphenyl)cyclohexyl cyclohexylcarbamate; trans-4-(2,4-Dihydroxyphenyl)cyclohexyl 4-tert-butylbenzoate; trans-4-(2,4-Dihydroxyphenyl)cyclohexyl 4-fluorobenzoate; trans-4-(2,4-Dihydroxyphenyl)cyclohexyl 4-trifluoromethylbenzoate; trans-4-(2,4-Dihydroxyphenyl)cyclohexyl 4-methoxybenzoate; trans-4-(2,4-Dihydroxyphenyl)cyclohexyl 4-methylbenzoate; trans-4-(2,4-Dihydroxyphenyl)cyclohexyl 4-chlorobenzoate; trans-4-(2,4-Dihydroxyphenyl)cyclohexyl 3,4-dimethylbenzoate; trans-4-(2,4-Dihydroxyphenyl)cyclohexyl 3,4-dichlorobenzoate; trans-4-[4-(Phenylsulfanyl)cyclohexyl]-1,3-benzenediol; trans-4-[4-(Phenylsulfonyl)cyclohexyl]-1,3-benzenediol; [4-(2,4-Dihydroxyphenyl)cyclohexyl]methyl propionate; ethyl4-(2,4-dihydroxyphenyl)-1-hydroxycyclohexane carboxylate; cis/trans-4-[4-(hydroxyamino)cyclohexyl]-1,3-benzenediol; trans-4-[4-(methoxyamino)cyclohexyl]-1,3-benzenediol;
and a pharmaceutically acceptable salt thereof.
[0141] The term “resorcinol derivative”, as used herein, refers to a compound comprising a resorcinol ring monosubstituted at the 4-position, as defined above, and is represented by the structure of formula I.
[0142] The term “alkyl”, as used herein, unless otherwise indicated, includes saturated monovalent hydrocarbon radicals having straight, branched or cyclic moieties or combinations thereof, which may or may not be further substituted. Any substituents or functional groups on the alkyl group, as indicated herein, can be substituted anywhere on the alkyl group where such substitutions are possible.
[0143] The term “aryl”, as used herein, refers to phenyl or naphthyl optionally substituted with one or more substituents, preferably from zero to two substituents, independently selected from halogen, OH, (C 1 -C 6 )alkyl, (C 1 -C 6 ) alkoxy, amino, (C 1 -C 6 )alkylamino, di-((C 1 -C 6 )alkyl))amino, nitro, cyano and trifluoromethyl. Any substituents or functional groups on the aryl group, as indicated herein, can be substituted anywhere on the aryl group.
[0144] The term “one or more substituents”, as used herein, refers to a number of substituents that equals from one to the maximum number of substituents possible based on the number of available bonding sites.
[0145] The “halo”, as used herein, refers to halogen and, unless otherwise indicated, includes chloro, fluoro, bromo and iodo.
[0146] The term “acyl”, as used herein, unless otherwise indicated, includes a radical of the general formula RCO wherein R is alkyl, alkoxy, aryl, arylalkyl, or arylalkyloxy and the terms “alkyl” or “aryl” are as defined above.
[0147] The term “acyloxy”, as used herein, includes O-acyl groups wherein “acyl” is as defined above.
[0148] (C 2 -C 9 )Heterocycloalkyl, when used herein, refers to pyrrolidinyl, tetrahydrofuranyl, dihydrofuranyl, tetrahydropyranyl, pyranyl, thiopyranyl, aziridinyl, oxiranyl, methylenedioxyl, chromenyl, isoxazolidinyl, 1,3-oxazolidin-3-yl, isothiazolidinyl, 1,3-thiazolidin-3-yl, 1,2-pyrazolidin-2-yl, 1,3-pyrazolidin-1-yl, piperidinyl, thiomorpholinyl, 1,2-tetrahydrothiazin-2-yl, 1,3-tetrahydrothiazin-3-yl, tetrahydrothiadiazinyl, morpholinyl, 1,2-tetrahydrodiazin-2-yl, 1,3-tetrahydrodiazin-1-yl, tetrahydroazepinyl, piperazinyl, chromanyl, etc. One of ordinary skill in the art will understand that the connection of said (C 2 -C 9 )heterocycloalkyl ring can be through a carbon atom or through a nitrogen heteroatom where possible.
[0149] (C 2 -C 9 )Heteroaryl, when used herein, refers to furyl, thienyl, thiazolyl, pyrazolyl, isothiazolyl, oxazolyl, isoxazolyl, pyrrolyl, triazolyl, tetrazolyl, imidazolyl, 1,3,5-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,3-oxadiazolyl, 1,3,5-thiadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, 1,3,5-triazinyl, pyrazolo[3,4-b]pyridinyl, cinnolinyl, pteridinyl, purinyl, 6,7-dihydro-5H-[1]pyridinyl, benzo[b]thiophenyl, 5,6,7,8-tetrahydro-quinolin-3-yl, benzoxazolyl, benzothiazolyl, benzisothiazolyl, benzisoxazolyl, benzimidazolyl, thianaphthenyl, isothianaphthenyl, benzofuranyl, isobenzofuranyl, isoindolyl, indolyl, indolizinyl, indazolyl, isoquinolyl, quinolyl, phthalazinyl, quinoxalinyl, quinazolinyl, benzoxazinyl, etc. One of ordinary skill in the art will understand that the connection of said (C 2 -C 9 )heterocycloalkyl rings can be through a carbon atom or through a nitrogen heteroatom where possible.
[0150] Compounds of formula I may contain chiral centers and therefore may exist in different enantiomeric and diastereomeric forms. This invention relates to preparation of all optical isomers, stereoisomers and tautomers of the compounds of formula I, and mixtures thereof.
[0151] Formula I, as defined above, also includes compounds identical to those depicted but for the fact that one or more hydrogen, carbon or other atoms are replaced by isotopes thereof. Such compounds may be useful as research and diagnostic tools in metabolism pharmacokinetic studies and in binding assays.
[0152] The present invention also relates to preparation of the pharmaceutically acceptable acid addition and base addition salts of any of the aforementioned compounds of formula I. The acids which are used to prepare the pharmaceutically acceptable acid addition salts of the aforementioned base compounds of this invention are those which form non-toxic acid addition salts, i.e., salts containing pharmacologically acceptable anions, such as the hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, acetate, lactate, citrate, acid citrate, tartrate, bitartrate, succinate, maleate, fumarate, gluconate, saccharate, benzoate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate and pamoate (i.e., 1,1-methylene-bis-(2-hydroxy-3naphthoate)) salts.
[0153] The present invention also provides various intermediate compounds useful in the preparation of wide variety of resorcinol derivatives.
[0154] The present invention provides an intermediate compound of formula (4), where W, X and Y are as defined above.
[0155] In a preferred embodiment, the intermediate compound of formula (4) has the structure of formula (4a),
where W is as defined above, and n is 0, 1, 2 or 3.
[0156] In a further preferred embodiment, the intermediate compound of formula (4) has the structure of formula (4b) or (4c),
where W is as defined above.
[0157] In a further preferred embodiment, the intermediate compound of formula (4) has the structure of formula (4d),
where W and Z are as defined above, and n is 0, 1, 2 or 3.
[0158] In a further preferred embodiment, the intermediate compound of formula (4) has the structure of formula (4e) or (4f),
where W and Z are as defined above.
[0159] In a further preferred embodiment, the intermediate compound of formula (4) has the structure of formula (4g),
where W and each Z are as defined above, and n is 0, 1, 2 or 3.
[0160] In a further preferred embodiment, the intermediate compound of formula (4) has the structure of formula (4h) or (4i),
where W and each Z are as defined above.
[0161] The present invention further provides an intermediate compound of formula (5),
where Q, W, X and Y are as defined above.
[0162] In a preferred embodiment, the intermediate compound of formula (5) has the structure of formula (5a)
wherein Q and W are as defined above, and n is 0, 1, 2, or 3.
[0163] In a further preferred embodiment, the intermediate compound of formula (5) has the structure of formula (5b) or (5c)
wherein Q and W are as defined above.
[0164] In a further preferred embodiment, the intermediate compound of formula (5) has the structure of formula (5d)
wherein Q, W and Z are as defined above, and n is 0, 1, 2, or 3.
[0165] In a further preferred embodiment, the intermediate compound of formula (5) has the structure of formula (5e) or (5f),
where Q, W and Z are as defined above.
[0166] In a further preferred embodiment, the intermediate compound of formula (5) has the structure of formula (5g)
wherein Q, W and Z are as defined above, and n is 0, 1, 2, or 3.
[0167] In a further preferred embodiment, the intermediate compound of formula (5) has the structure of formula (5h) or (5i),
wherein Q, W and each Z are as defined above.
[0168] The present invention further provides an intermediate compound of formula (5′),
wherein Q, X and Y are as defined above.
[0169] In a preferred embodiment, the intermediate compound of formula (5′) has the structure of formula (5′a),
where Q is as defined above, and n is 0, 1, 2 or 3.
[0170] In a further preferred embodiment, the intermediate compound of formula (5′) has the structure of formula (5′b) or (5′c),
wherein Q is as defined above.
[0171] In a further preferred embodiment, the intermediate compound of formula (5′) has the structure of formula (5′d) or (5′e),
wherein Q and Z are as defined above.
[0172] In a further preferred embodiment, the intermediate compound of formula (5′) has the structure of formula (5′f) or (5′g),
wherein Q and each Z are as defined above.
DETAILED DESCRIPTION OF THE INVENTION
[0173] The process of the present invention is described in the following reaction schemes and discussion.
[0174] Referring to Scheme 1, compounds of formula (2) can be prepared starting with compound (1), which is commercially available (Aldrich Chemical Co.). A suitable protecting group can be selected as will be evident to those of skill in the art. An example of a suitable protecting group is benzyl. Conversion to compounds of formula (2) can occur under standard conditions. For instance, where the protecting group is benzyl, condensation can occur between compound (1) and benzyl alcohol with the removal of water using Dean-Stark apparatus. Condensation of compounds of formula (2) with compounds of formula (3) may occur using standard techniques, for instance, treatment of compounds of formula (2) with a base, such as lithium diisopropylamide or lithium hexamethyidisilazide, in an ethereal solvent followed by the addition of a compound of formula (3) would give compounds of formula (4). When W is H, condensation of compounds of formula (2) with compounds of formula (3) requires the use of at least two equivalents of a suitable base such as lithium diisopropylamide in an suitable solvent such as tetrahydrofuran, with a suitable co-solvent such as hexamethylphosphoramide. Treatment of compounds of formula (4) with a suitable halogenating reagent such as, for example, N-bromosuccinimide in a chlorinated solvent, such as dichloromethane or chloroform, at about room temperature, can give compounds of formula (5) where Q is halo, and preferably bromo. Where W is H, the compound of formula (5) may exist in equilibrium with the compound of formula (5′). Alternatively, where W is H, compounds of formula (5′) may be prepared directly from compounds of formula (4) by treatment of the compound of formula (4) with a suitable halogenating agent. The process of the present invention is intended to encompass each of these various synthesis routes.
[0175] Compounds of formula (6) may then be generated from compounds of formula (5) or (5′) under suitable conditions. Such conditions may involve treating compounds of formula (5) or (5′) with a base such as, e.g., 1,8-diazobicyclo[5.4.0]undec-7-ene in a suitable solvent such as N,N-dimethylformamide at about room temperature. Compounds of formula I(a) may be generated using standard techniques, e.g., treating compounds of formula (6) with triethylsilane in the presence of a Lewis acid such as boron trifluoride in a chloronated solvent, followed by suitable conditions to remove the protecting group, or hydrogenating compounds of formula (6) under standard conditions, would yield compounds of formula I(a). Compounds of formula (7) may be generated from compounds of formula (5), (5′) or (6) under suitable reaction conditions. Such conditions may involve treating compounds of formula (5) or (5′) or (6) with a base such as, e.g., 1,8-diazobicyclo[5.4.0)undec-7-ene in a suitable solvent such as N,N-dimethylformamide at about 140° C. Other solvents such as toluene or N-methylpyrrolidinone may also be useful for this purpose. Subjection of compounds of formula (7) to standard hydrogenation conditions, e.g., hydrogen gas and palladium on charcoal in ethanol, yields compounds of the general formula I(a) when the protecting group was benzyl. Where W is a protecting group, compounds of formula I(b) can be formed by treating compounds of formula (7) to standard conditions that will be obvious to those with skill in the art. Compounds of formula I(b) can in turn be converted to compounds of formula I(a) by standard hydrogenation conditions, such as described above. Compounds I(a) and I(b) fall within the scope of formula I.
[0176] Referring to Scheme 2 as an example of a more specific scheme, compounds of formula (8) can be prepared starting with compound (1), which is commercially available (Aldrich Chemical Co.). Conversion to compounds of formula (8) can occur under standard conditions, for instance where the protecting group is benzyl, condensation can occur between compound (1) and benzyl alcohol with the removal of water using Dean-Stark apparatus. Condensation of compounds of formula (8) with compounds of formula (9) may occur using standard techniques, for instance, treatment of compounds of formula (8) with a base such as lithium diisopropylamide in an ethereal solvent followed by the addition of a compound of formula (9) would give compounds of formula (10). Treatment of compounds of formula (10) with a suitable brominating reagent, such as N-bromosuccinimide in a chlorinated solvent at about room temperature, can give compounds of formula (11). Compounds of formula (12) may then be generated from compounds of formula (11) under suitable reaction conditions. Such conditions may involve treating compounds of formula (11) with a base such as 1,8-diazobicyclo[5.4.0]undec-7-ene in a suitable solvent such as N,N-dimethylformamide at about 140° C. Subjection of compounds of formula (12) to standard hydrogenation conditions, e.g., hydrogen gas and palladium on charcoal in an ethanol/tetrahydrofuran mixture, yields compounds of the general formula l(c) when the protecting group was benzyl. Compounds of formula I(d) may then be obtained by subjecting compounds of formula I(c) to acidic conditions. Compounds of formulae I(c) and I(d) both fall within the scope of formula I.
[0177] It will be appreciated by those of skill in the art that in the processes described above, the functional groups of intermediate compounds may need to be protected. The use of protecting groups is well-known in the art, and is fully described, among other places, in: Protecting Groups in Organic Chemistry, J. W. F. McOmie, (ed.), 1973, Plenum Press; and in: Protecting Groups in Organic Synthesis, 2 nd edition, T. W. Greene & P. G. M. Wutz, 1991, Wiley-Interscience, which are incorporated herein by reference in their entirety.
[0178] Resorcinol derivatives prepared according to the process described herein are useful for all of the purposes previously described for these types of compounds. For example, resorcinol derivatives useful as skin-lightening agents or for other cosmetic purposes can be prepared according to the process of the present invention.
[0179] Where resorcinol derivatives prepared according to the present invention are useful as skin-lightening agents, these may be used to treat disorders of human pigmentation, including solar and simple lentigines (including age/liver spots), melasma/chloasma and postinflammatory hyperpigmentation. Such compounds reduce skin melanin levels by inhibiting the production of melanin, whether the latter is produced constitutively or in response to UV irradiation (such as sun exposure), and typically by inhibition of the enzyme tyrosinase. Active skin-lightening compounds prepared according to the present invention can be used to reduce skin melanin content in non-pathological states so as to induce a lighter skin tone, as desired by the user, or to prevent melanin accumulation in skin that has been exposed to UV irradiation. They can also be used in combination with skin peeling agents (including glycolic acid or trichloroacetic acid face peels) to lighten skin tone and prevent repigmentation. The appropriate dose regimen, the amount of each dose administered, and specific intervals between doses of the active compound will depend upon the particular active compound employed, the condition of the patient being treated, and the nature and severity of the disorder or condition being treated. Preferably, the active compound is administered in an amount and at an interval that results in the desired treatment of or improvement in the disorder or condition being treated.
[0180] An active compound prepared according to the process of the present invention can also be used in combination with sun screens (UVA or UVB blockers) to prevent repigmentation, to protect against sun or UV-induced skin darkening or to enhance their ability to reduce skin melanin and their skin bleaching action. An active compound prepared according the process of the present invention can also be used in combination with retinoic acid or its derivatives or any compounds that interact with retinoic acid receptors and accelerate or enhance the invention's ability to reduce skin melanin and skin bleaching action, or enhance the invention's ability to prevent the accumulation of skin melanin. An active compound prepared according to the present invention can also be used in combination with 4-hydroxyanisole.
[0181] The active compounds prepared according to the process of the present invention can also be used in combination with ascorbic acid, its derivatives and ascorbic-acid based products (such as magnesium ascorbate) or other products with an anti-oxidant mechanism (such as resveratrol) which accelerate or enhance their ability to reduce skin melanin and their skin bleaching action.
[0182] Skin-lightening active compounds prepared according to the present invention are generally administered in the form of pharmaceutical compositions comprising at least one of the compounds of formula (I), together with a pharmaceutically acceptable vehicle or diluent. Such compositions are generally formulated in a conventional manner utilizing solid or liquid vehicles or diluents as appropriate for topical administration, in the form of solutions, gels, creams, jellies, pastes, lotions, ointments, salves, aerosols and the like.
[0183] Examples of vehicles for application of the active compounds of this invention include an aqueous or water-alcohol solution, an emulsion of the oil-in-water or water-in-oil type, an emulsified gel, or a two-phase system. Preferably, the compositions according to the invention are in the form of lotions, creams, milks, gels, masks, microspheres or nanospheres, or vesicular dispersions. In the case of vesicular dispersions, the lipids of which the vesicles are made can be of the ionic or nonionic type, or a mixture thereof.
[0184] In a skin-lightening composition comprising a resorcinol derivative prepared according to the process of the present invention, the concentration of the resorcinol derivative is generally between 0.01 and 10%, preferably between 0.1 and 10%, relative to the total weight of the composition.
[0185] A skin-lightening resorcinol derivative prepared according to the present invention can be conveniently identified by its ability to inhibit the enzyme tyrosinase, as determined by any standard assay, such as those described below.
[0186] 1. Tyrosinase (DOPA Oxidase) Assay Using Cell Lysate:
[0187] Human melanoma cell line, SKMEL 188 (licensed from Memorial Sloan-Kettering), is used in the cell lysate assay and the screen. In the assay, compounds and L-dihydroxyphenylalanine (L-DOPA) (100 μg/ml) are incubated with the cell lysates containing human tyrosinase for 8 hrs before the plates are read at 405 nm. Potency of the compounds in DOPA oxidase assay is correlated very well with that in tyrosine hydroxylase assay using 3 H-tyrosine as a substrate.
[0188] 2. Melanin Assay in Human Primary Melanocytes:
[0189] Compounds are incubated with human primary melanocytes in the presence of α-melanocyte stimulating hormone (α-MSH) for 2-3 days. Cells are then lysed with sodium hydroxide and sodium dodecyl sulfate (SDS) and melanin signals are read at 405 nm. Alternatively, 14 C-DOPA is added to the cells in combination with tyrosinase inhibitors and acid-insoluble 14 C-melanin is quantitated by a scintillation counter. IC 50 's reflect the inhibitory potency of the compounds in the new melanin synthesis that was stimulated by α-MSH.
[0190] 3. Tyrosine Kinase Assay (TK):
[0191] TK assays can be performed using purified tyrosine kinase domains of c-met, erb-B2, or IGF-r. A specific antibody against phosphorylated tyrosine residue is used in the assay. Colorimetric signals are generated by horseradish peroxidase, which is conjugated to the antibody.
[0192] 4. Human Skin Equivalent Model:
[0193] A mixture of human melanocytes and keratinocytes is grown in an air-liquid interphase. This tissue culture forms a three dimensional structure that histologically and microscopically resembles the human skin epidermis. Test compounds are added on top of the cells to mimic topical drug application. After incubation with the compounds (10 μM) for 3 days, the cells are washed extensively and lysed for DOPA oxidase assay.
[0194] 5. IL-1 Assay (Interleukin-1 Assay):
[0195] An IL-1α ELISA assay (R&D system) can be used to evaluate the effect of compounds on IL-1 secretion in a human skin equivalent model. IL-1α is a pro-inflammatory cytokine and plays a role in UV-induced skin inflammation.
[0000] 6. In Vivo Study:
[0196] Black or dark brown guinea pigs with homogeneous skin color can be used in this study. A solution of the test compound of formula 1 (5% in ethanol:propylene glycol, 70:30) and the vehicle control are applied to the animals twice daily, 5 days per week for 4-8 weeks. Using this assay, depigmentation can be determined by subtracting the light reflectance of untreated skin from the light reflectance of treated skin.
[0197] The present invention is illustrated by the following examples. It will be understood, however, that the invention is not limited to the specific details of these examples. Melting points are uncorrected. Proton nuclear magnetic resonance spectra (400 MHz 1 H NMR) were measured for solutions in d 6 -DMSO, CDCl 3 , or d 4 -MeOH, and peak positions are expressed in parts per million (ppm) downfield from tetramethylsilane (TMS). The peak shapes are denoted as follows: s, singlet; d, doublet; t, triplet; q, quartet, m, multiplet, b, broad.
[0198] The following examples are illustrative only, and are not intended to limit the scope of the present invention.
EXAMPLES
Intermediate 1
3-(Benzyloxy)-2-cyclohexen-1-one
[0199] To a round bottomed flask equipped with magnetic stirrer and Dean Stark apparatus was added 1,3-cyclohexanedione (70.0 g, 624 mmol), toluene (500 ml), p-toluenesulfonic acid monohydrate (1.68 g, 8.83 mmol) and benzyl alcohol (65.6 g, 606 mmol). The resulting solution was heated under reflux for 2 hr. The reaction mixture was cooled to room temperature and washed with saturated aqueous sodium carbonate solution (4×50 ml). The organic layer was washed with brine (50 ml), dried over magnesium sulfate, filtered and concentrated in vacuo, affording a brown oil which crystallised upon standing. The crude crystalline material was slurried in isopropyl ether (100 ml) and stirred at 0° C. for 2 hr. The mixture was filtered and the crystalline material was washed with ice cold isopropyl ether (3×100 ml) followed by cold petroleum ether (100 ml). The resulting solid was dried overnight under reduced pressure to furnish the title compound (85.3g, 68%). m/z (ES + ) 203 (M+H + ).
Intermediate 2
(±)-3-(Benzyloxy)-6-(8-hydroxy-1,4-dioxaspiro[4.5]dec-8-yl)-2-cyclohexen-1-one
[0200] To a round bottomed flask equipped with magnetic stirrer was added anhydrous tetrahydrofuran (600 ml) and diisopropylamine (38.1 ml, 272 mmol). The stirred solution was cooled to −78° C. and n-butyl lithium (113.4 ml, 272 mmol, 2.4 M in hexanes) was added dropwise via syringe in 20 ml portions. The resulting yellow solution was stirred for 35 min at −78° C., then 3-(benzyloxy)-2-cyclohexen-1-one (50.0 g, 248 mmol) was added as a solution in anhydrous tetrahydrofuran (100 ml). The solution was stirred for 1 hr prior to the addition of cyclohexane-1,4-dione monoethylene ketal (38.7 g, 248 mmol) as a solution in anhydrous tetrahydrofuran (100 ml). The solution was stirred for 2 hr at −78° C., then allowed to warm slowly to room temperature over 1 hr. Saturated aqueous ammonium chloride (80 ml) was added, followed by dichloromethane (700 ml) and the mixture was stirred until no solids remained. The layers were separated and the aqueous phase extracted with dichloromethane (2×100 ml). The combined organic layers were washed with brine (50 ml), dried over magnesium sulfate, then concentrated in vacuo. Trituration of the resulting solid with methanol afforded the title compound (78.4 g, 88%). m/z (ES + ) 359 (M+H + ).
Intermediate 3
(±)-1-(Benzyloxy)-6-bromo-3-(1,4-dioxaspiro[4,5]dec-8-yl)-2-oxabicyclo[2.2.2]octan-5-one
[0201] A round bottomed flask equipped with magnetic stirrer was charged with (±)-3-(benzyloxy)-6-(8-hydroxy-1,4-dioxaspiro[4.5]dec-8-yl)-2-cyclohexen-1-one (78.4 g, 219 mmol) and dichloromethane (600 ml). To the stirred solution was added N-bromosuccinimide (40.9 g, 230 mmol) in one portion, followed by aqueous hydrobromic acid (3 drops, 48% aqueous solution). The resulting solution was stirred at room temperature for 2 hr, then poured into a separating funnel containing aqueous sodium metabisulfite solution (150 ml) and dichloromethane (200 ml) and the funnel was shaken vigorously. The layers were separated and the organic layer was washed with brine (200 ml), dried over magnesium sulfate, filtered, then concentrated in vacuo to give a solid. Trituration with methanol (500 ml) afforded the title compound (82.8 g, 86%) as a white solid. m/z (ES + ) 437 and 439 [(1:1), M+H + ).
Intermediate 4
5-(Benzyloxy)-2-(1,4-dioxaspiro[4.5]dec-7-en-8-yl)phenol
[0202] A round bottomed flask was charged with (±)-1-(benzyloxy)-6-bromo-3-(1,4-dioxaspiro[4.5]dec-8-yl)-2- oxabicyclo[2.2.2]octan-5-one (36 g, 82.4 mmol) anhydrous N,N-dimethylformamide (300 ml). To the stirred solution was added 1,8-diazabicyclo[5.4.0)undec-7-ene (13.6 ml, 90.6 mmol) in one portion before heating to 140° C. for 19 hr with vigorous stirring. The reaction mixture was allowed to cool to room temperature and most of the solvent was removed under reduced pressure. The remaining oil was partitioned between dichloromethane (500 ml) and water (100 ml), and the layers were separated. The organic phase was washed with water (2×100 ml) followed by brine (100ml). The organic phase was dried over magnesium sulfate, filtered and concentrated in vacuo to afford a brown solid which was adsorbed onto silica gel. Purification via flash column chromatography (SiO 2 , dichloromethane then ethyl acetate/petroleum ether, 3:7, v/v) furnished an off white solid which was slurried in methanol (150 ml). The slurry was stirred for 20 min, filtered and washed with methanol (50 ml). The title compound (18.2 g, 65%) was isolated as a white solid after removal of excess solvent under reduced pressure. m/z (ES + ) 339(M+H + ).
Example 1
4-(1,4-Dioxaspiro[4.5]dec-8-yl)-1,3-benzenediol
[0203] A round bottomed flask equipped with magnetic stirrer was charged with 5-(benzyloxy)-2-(1,4-dioxaspiro[4.5]dec-7-en-8-yl)phenol (14.5 g, 42.8 mmol) and tetrahydrofuran (50 ml). The stirred mixture was gently heated until a solution formed, after which the solution was allowed to cool to room temperature. Ethanol (100 ml) and palladium (4.54 g, 10% on activated carbon) were added sequentially. The reaction vessel was then evacuated, placed under a hydrogen atmosphere and stirred vigorously for 24 hr. The reaction mixture was filtered through a celite plug, washing with ethyl acetate. The filtrate was concentrated in vacuo to give an off white solid. The crude solid was slurried in dichloromethane (200 ml), then collected on a sinter, affording the title compound (10.2 g, 95%) as a white solid. m/z (ES + ) 251 (M+H + ).
Example 2
4-(2,4-Dihydroxyphenyl)cyclohexanone
[0204] A round bottomed flask equipped with magnetic stirrer was charged with 4-(1,4-dioxaspiro[4.5]dec-8-yl)-1,3-benzenediol (11.3 g, 45.2 mmol), acetone (250 ml) and water (50 ml). To the stirred solution was added pyridinium p - toluenesulfonate (1.14 g, 4.52 mmol) in one portion and the reaction mixture was then heated under reflux for 8 hr. After allowing the reaction mixture to cool to room temperature, most of the acetone was removed in vacuo and the remaining mixture was partitioned between ethyl acetate (200 ml) and water (50 ml). The aqueous layer was extracted with ethyl acetate (3×50 ml) and the combined organic layers were washed with brine (30 ml), dried over magnesium sulfate, filtered and concentrated under reduced pressure to afford an off-white powder. After washing the powder with dichloromethane (100 ml) and removal of excess solvent under reduced pressure, the title compound (9.30 g, 100%) was obtained as an off-white powder. m/z (ES + ) 207 (M+H + ); δ H (CD 3 OD) 1.84-1.97 (2H, m), 2.15-2.23 (2H, m), 2.36-2.45 (2H, m), 2.58-2.68 (2H, m), 3.39 (1H, tt), 6.26 (1H, dd), 6.34 (1H, d), 6.96 (1H, d).
[0205] All patents, patent applications, and publications cited above are incorporated herein by reference in their entirety.
[0206] The present invention is not to be limited in scope by the specific embodiments described herein, which are intended as single illustrations of individual aspects of the invention, and functionally equivalent methods and components are within the scope of the invention. Indeed, various modifications of the invention, in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are intended to fall within the scope of the appended claims.
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The present invention relates to an improved process for preparing 4-substituted resorcinol derivatives, and intermediate compounds useful in the preparation of such resorcinol derivatives.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of co-pending application Ser. No. 07/301,472 filed Jan. 26, 1989 now abandoned.
TECHNICAL FIELD
The field of art to which this invention pertains is electrodepositable compositions containing aminoplast resins with metal catalysts to be used in cathodic electrocoat processes.
BACKGROUND ART
The coating of electrically conductive substrates by electrodeposition is a well known and important industrial process. (For instance, electrodeposition is widely used in the automotive industry to apply primers to automotive substrates). In this process, a conductive article is immersed as one electrode in a coating composition made from an aqueous emulsion of film-forming polymer. An electric current is passed between the article and a counter-electrode in electrical contact with the aqueous emulsion, until a desired coating is produced on the article. Early electrodeposition was conducted with the article to be coated serving as the anode. This was familiarly referred to as anodic electrodeposition. Currently, the article to be coated typically serves as the cathode in the electrical circuit with the counter-electrode being the anode. This is known as cathodic electrodeposition.
Resin compositions used in cathodic electrodeposition baths are also well known in the art. These resins are usually manufactured from polyepoxide resins which have been chain extended and adducted to include a nitrogen atom. The nitrogen is typically introduced through reaction with an amine compound. Normally these resins are blended with a crosslinking agent and then salted with an acid to form a water emulsion which is usually referred to as a principal emulsion.
The principal emulsion is combined with a pigment paste, coalescent solvents, water, and other additives to form the electrodeposition bath. The electrodeposition bath is placed in an insulated tank containing the anode. The article to be coated is made the cathode and is passed through the tank containing the electrodeposition bath. The thickness of the coating is a function of the bath characteristics, the electrical operating characteristics, the immersion time, and so forth.
The coated object is removed from the bath after a fixed period of time (normally about two or three minutes). The object is rinsed with deionized water and the coating is cured, typically in an oven at sufficient temperature to produce crosslinking.
The first cathodic electrodepositable compositions used amine salt group-containing resins or onium salt group-containing resins as the binder, see, for example, U.S. Pat. No. 3,454,482 to Spoor et al and U.S. Pat. No. 3,839,252 to Bosso and Wismer. The curing agents for these resins were usually aminoplasts since these curing agents were used quite successfully with the earlier anodic electrodepositable resins. However, it was initially found that the aminoplasts were not completely satisfactory for use in cathodic electrodeposition. Aminoplasts cure best in an acidic environment. With anodic electrodeposition, this poses no problem since the anodically electrodeposited coating is acidic. However, the cathodically electrodeposited coating is basic and relatively high temperatures, that is, about 400° F. (204° C.) or higher must be used for complete curing of the cathodically electrodeposited coating.
Attempts have been made to overcome this problem by utilizing an acid-functional aminoplast as crosslinker with the hydroxyl containing amino epoxy resin (U.S. Pat. No. 4,066,525). However, this approach has not been found to be satisfactory because a high cure temperature of over 175° C. is required. Other approaches include using quaternary onium salt-containing resins in combination with an aminoplast or a methylol-phenol ether (U.S. Pat. No. 3,937,679) disclosing 400° F. cure temperature. U.S. Pat. No. 4,501,833 also discloses quaternary onium salt containing resins in combination with high imino functional aminoplasts. While the '833 patent discloses relatively low cure temperature, we have found performance is not satisfactory because the coated film is rough and too thin.
Another approach is disclosed in U.S. Pat. No. 4,363,710 utilizing a resin with primary amino functionality and a melamine/formaldehyde crosslinker, catalyzed with a phenolic blocked phosphoric acid ester. However this system shows only very high temperature cure (180° C. or above for 20 minutes).
There is a need for a cathodic electrodeposition process using aminoplasts which will give a good smooth coating and yet cure at low temperatures in a basic environment. We have found that an aminoplast system will cure at low temperatures (100° C. to 150° C.) in a basic environment (i.e. cathodic system) if catalyzed by metal catalysts. The metal catalysts are metal salts of both organic acid salts or inorganic acid salts such as Cu, Fe, Mn, Co, Pb, Bi, Zn and Sn octoate and napthanate. As stated above, this result is very surprising, as it was previously thought that aminoplast resins would only cure in an acid environment at these relatively low temperatures.
Metal catalysts are known in the art to catalyze certain coating compositions but metal catalysts are not known to cure aminoplasts. Prior art references teach the use of metal catalysts for the following: alkyd oxidative cure (U.S. Pat. No. 4,495,327); in an electrocoat system for transesterification (U.S. Pat. No. 4,352,842 and U.S. Pat. No. 4,644,036); and in electrocoat systems for amidation (U.S. Pat. No. 4,477,530). There is nothing in the prior art to suggest their use to catalyze the reaction of aminoplast resins.
The novel resin of this invention is not restricted to cathodic electrodeposition. It also could be used in non-electrocoat applications such as spray applications, roller coating, dip applications, and so forth.
SUMMARY OF THE INVENTION
In accordance with the present invention, a novel, improved cathodic electrodeposition coating composition is disclosed using aminoplast resins. More specifically, our coating composition comprises a typical polyepoxy resin with primary or secondary amino functionality crosslinked with aminoplasts (melamine/formaldehyde or urea-formaldehyde crosslinker) and catalyzed by metal catalysts. The novel composition provides a smooth coating with good top coat adhesion and corrosion resistance which will cure at 100° C. to 150° C.
DETAILED DESCRIPTION
The amino functional backbone resin which is used in the practice of this invention is typically obtained by reacting polyepoxide resins with nitrogen containing compounds such that the resin becomes amino functional. The resin should contain either primary or secondary amino functionality and most preferably primary amino functionality. The polyepoxide resins which are used to make the amino functional resins are well known in the art.
The polyepoxide resins which are used in the practice of the invention are polymers having a 1,2-epoxy equivalency greater than one and preferably about two, that is, polyepoxides which have on an average basis two epoxy groups per molecule. The preferred polyepoxides are polyglycidyl ethers of cyclic polyols. Particularly preferred are polyglycidyl ethers of polyhydric phenols such as bisphenol A. These polyepoxides can be produced by etherification of polyhydric phenols with epihalohydrin or dihalohydrin such as epichlorohydrin or dichlorohydrin in the presence of alkali. Examples of polyhydric phenols are
2,2-bis-(4-hydroxy-3-tertiarybutylphenyl)propane,
1,1-bis-(4-hydroxyphenyl)ethane.
2-methyl-1,1-bis-(4-hydroxyphenyl) propane.
2,2-bis-(4-hydroxy-3-tertiarybutylphenyl)propane.
bis-(2-hydroxynaphthyl methane.
1,5-dihydroxy-3-naphthalene or the like.
Besides polyhydric phenols, other cyclic polyols can be used in preparing the polyglycidyl ethers of cyclic polyol derivatives. Examples of other cyclic polyols would be alicyclic polyols, particularly cycloaliphatic polyols, such as
1,2-cyclohexanediol, 1,4-cyclohexanediol,
1.2-bis(hydroxymethyl)cyclohexane,
1,3-bis-(hydroxymethyl)cyclohexane and hydrogenated bisphenol A.
The polyepoxides have number average molecular weights (Mn) of at least 200 and preferably within the range of 200 to 2000, and more preferably about 340 to 2000.
The polyepoxides are preferably chain extended with a polyether or a polyester polyol which increases rupture voltage of the composition and enhances flow and coalescence. Examples of polyether polyols and conditions for chain extension are disclosed in U.S. Pat. No. 4,468,307, column 2, line 67, to column 4, line 52, the portions of which are hereby incorporated by reference. Examples of polyester polyols for chain extension are disclosed in U.S. Pat. No. 4,148,772, column 4, line 42, to column 5, lines 53, the portions of which are hereby incorporated by reference.
In addition to the polyepoxide backbone resin, this invention would also be applicable to acrylic, polybutadiene, polyester or phenolic resins which contain amino functionality.
The backbone resin is given its amino functionality by reacting it with nitrogen containing materials. More specifically, the primary amino functionality can be imparted by the ketimine approach as shown by U.S. Pat. No. 4,104,147 or the ammoniation approach as shown by U.S. Pat. No. 4,310,645. Preferably the amino functionality on the backbone resin is primary amino or secondary amino functionality. Most preferably the amino functionality is primary. The ketimine approach appears to be the most preferred method of imparting the amino functionality.
The crosslinkers in this invention are aminoplast resins. The aminoplast resins must have either a high imino content or a high methylol content (or a mixture thereof) and also a low water solubility. The sum of the imino functional groups and methylol functional groups must be at least 20 percent and preferably 30 percent of the total available functional sites on the aminoplast resin. A commmercial example of such an aminoplast resin is Cymel 1158®.
Furthermore an aminoplast resin that is to be used in electrodeposition must be substantially water insoluble in order to ensure codeposition with the electrocoat backbone resin. At least 50 percent or more and preferably 75 percent or more of the aminoplast resin must partition into the discrete phase (the discrete phase contains the back-bone resin, pigments, heavy metal catalyst and additives). The aminoplast resin must be at least about as water insoluble as Cymel 1158®.
Melamine-formaldehyde resins having either a high imino content or a high methylol content (or a mixture thereof) and also a low water solubility are commercially from the Monsanto Company under the trademark Resimene® and from American Cyanamid under the trademark Cymel®. Our preferred aminoplast is one which contains high imino groups such as Cymel® 1158. It is also possible to use partially alkylated resins containing methyol groups. Less preferred are highly alkylated aminoplasts such as Cymel® 300 and Cymel® 1160. In addition, carboxyl modified amino resins such as the Cymel® 1100 resins (specifically Cymel® 1141 and Cymel® 1125) could be utilized in the invention. These carboxyl modified amino resins must also be substantially water insoluble and have the imino content and/or methylol content described above for other aminoplast resins.
Another type of aminoplast resin which can be used as the crosslinker are urea-formaldehyde resins. These resins are commercially available from American Cynamide Co. under the tradename Beetle®. These resins are also chosen according to the imino content and/or methylol content. The preferred urea-formaldehyde resins are ones which contains methylol groups such as Beetle® 55, 60, or 65. Less preferred are urea-formaldehyde resins which are highly alkylated such as Beetle® 80.
The metal catalysts of our invention are metal salts of both organic acids or inorganic acids, or coordination compounds of these metals. Organic acid salts are more desirable, particularly organic acid salts that are compatible with the resin compositions and that are water insoluble. These usually are metallic soaps of monocarboxylic acids containing 7 to 22 carbon atoms.
The metals used in the catalyst are iron, lead, lithium, potassium, sodium, calcium, magnesium, beryllium, aluminum, zinc, cadmium, barium, scandium, gallium, indium, tin, vanadium, manganese, molybdenum, tellurium, silver, copper, nickel, cobalt, chromium, palladium and so forth.
Our preferred catalysts are Co, Cu, Fe and Pb octoates or napthenates. These catalysts are commercially available from Huls American Inc. under the tradenames Nuodex® or Nuxtra®. We have found that especially preferred catalysts are chelates of the metals such as coordination compounds or complexes of the metal with Lewis bases or ligands. Our most preferred catalyst is cobalt acetyl acetonate.
The amine functional resin and the aminoplast crosslinker are the principal resinous ingredients in the electrocoating composition. They are usually present in a ratio of backbone resin to crosslinker of about 40/60 to 95/5 percent by weight of solids. Preferably, the ratio is 85/15 to 65/35 backbone resin to crosslinker. The metal catalyst is typically present in amounts of about 0.1 to 5.0 percent by weight of total resin solids. Preferably, the metal catalyst is present from 0.5 to 1.5 percent by weight of total resin solids.
Besides the resinous ingredients described above, the electrocoating compositions usually contain a pigment which is incorporated into the composition in the form of a paste. The pigment paste is prepared by grinding or dispersing a pigment into a grinding vehicle and optional ingredients such as wetting agents, surfactants and defoamers. Pigment grinding vehicles are well known in the art. After grinding, the particle size of the pigment should be as small as practical, generally a Hegman grinding gauge of about 6 to 8 is usually employed.
Pigments which can be employed in the practice of the invention include titanium dioxide, basic lead silicate, strontium chromate, carbon black, iron oxide, clay and so forth. Pigments with high surface areas and oil absorbencies should be used judiciously because they can have an undesirable effect on coalescence and flow.
The pigment-to-resin weight ratio is also fairly important and should be preferably less than 0.5:1, more preferably less than 0.4:1, and usually about 0.2 to 0.4:1. Higher pigment-to-resin solids weight ratios have also been found to adversely affect coalescence and flow.
The coating composition of the invention can contain optional ingredients such as plasticizers, wetting agents, surfactants, defoamers and so forth. Examples of surfactants and wetting agents include alkyl imidazolines such as those available from Ciba-Geigy Industrial Chemicals as "Amine C", and from Air Products as "Surfynol 104". These optional ingredients, when present, constitute from about 0 to 20 percent by weight of total resin solids. Plasticizers are preferred optional ingredients because they promote flow. Examples are high boiling water immiscible materials such as ethylene or propylene oxide adducts of nonyl phenols or bisphenol A. When plasticizers are used, they are used in amounts of about 0.5 to 10.0 percent by weight of total resin solids.
The electrodepositable coating compositions of the present invention are dispersed in aqueous medium. The term "dispersion" as used within the context of the present invention is believed to be a two-phase translucent or opaque aqueous resinous system in which the resin is in the dispersed phase and water the continuous phase. The average particle size diameter of the resinous phase is about 0.1 to 5.0 microns, preferably less than 1 micron. The concentration of the resinous products in the aqueous medium is, in general, not critical, but ordinarily the major portion of the aqueous dispersion is water. The aqueous dispersion usually contains from about 3 to 75, typically 5 to 50 percent by weight of total resin solids. Aqueous resin concentrates which are to be further diluted with water at the job site generally range from 30 to 75 percent by weight of total resin solids. Fully diluted electrodeposition baths generally have resin solids content of about 3 to 25 percent by weight of total resin solids.
Besides water, the aqueous medium may also contain a coalescing solvent. Useful coalescing solvents include hydrocarbons, alcohols, esters, ethers and ketones. The preferred coalescing solvents include alcohols, polyols and ketones. Specific coalescing solvents include butanol, 2-ethylhexanol, 4-methoxy-2-pentanone, ethylene and propylene glycol and the monoethyl, monobutyl, monohexyl and 2-ethylhexyl ethers of ethylene glycol. The amount of coalescing solvent is not unduly critical and is generally between about 0 to 15 percent by weight, preferably about 0.5 to 5 percent by weight based on total weight of the aqueous medium.
EXAMPLES
Example I
Preparation of Amine Containing Resin
(A) Preparation of Monoketimine
416.0 grams (4 gm-moles) of 2-(2-aminoethylamine) ethanol and 800.0 grams (8 gm-moles) of methylisobutylketone were charged to a 2-liter, three-neck reaction flask equipped with agitator, condenser, water separator, thermometer and heating mantle. The mixture was heated and held at reflux (initial reflux temperature was at 110° C.) and water (by-product) was azeotropically removed. When 74.0 grams of water was removed, 214 grams of methyisobutylketone was stripped off and the batch was cooled to 50° C. under a dry N 2 gas blanket and was packaged to be used in part (B). This product has a total amine equivalent of about 128.9 at 72.0 percent solids with amine functionality of two.
(B) Preparation of Primary Amine Containing Resin
A primary amine containing resin was prepared from the following ingredients:
______________________________________ SolidsIngredients in Grams Equivalents Grams______________________________________"Synfac 8105".sup.1 299.8 0.92 299.8Bisphenol A 264.2 2.32 264.2Methyisobutylketone (MIBK) -- 11.4(first portion)Diethanolamine 5.6 0.05 5.6"DER-361".sup.2 520.7 2.67 520.7Diethanolamine 5.2 0.05 5.2Hexyl "Cellosolve" 34.6Butyl "Cellosolve" 39.5MIBK (second portion) 200.7Monoketimine 197.2 2.12 273.9(prepared above)Deionized Water 30.0MIBK (third portion) 361.0TOTAL 2046.6______________________________________ .sup.1 Polyether epoxy from Milliken Chemical Co. formed from reacting bisphenol A with propylene oxide and epichlorohydrin having epoxy equivalent of 325. .sup.2 Epoxy resin from Dow Chemical Co. formed from reacting epichlorohydrin and bisphenol A having epoxy equivalent of 195.
The "Synfac 8105", bisphenol A, MIBK (first portion) and diethanol amine were charged to a reaction vessel and heated with a nitrogen purge to 130° C. After an exotherm, the batch was held at 150° C. for about two hours until the milliequivalent of combined amine and epoxy per gram solution was equal or less than 0.2. The batch was cooled to 120° C. and then the "DER-361" and diethanol amine were added and the batch was held at 120° C. for about one and one-half hours until the milliequivalent of the combined amine and epoxy per gram solution was between 1.21 to 1.17. The batch was then diluted with hexyl "cellosolve", butyl "cellosolve" and MIBK (second portion) and cooled to 70° C. The monoketimine was added and held at 70° C. for one hour. Then the batch temperature was raised to 120° C. and held for two hours followed by cooling to 90° C. After the addition of deionized water and the MIBK solvent (third portion), the batch was cooled to 50° C. and packaged.
TABLE 1 (below) shows the formulation of the amino epoxy resin using various aminoplasts with or without metal catalysts incorporated.
TABLE 2 (below) shows the solvent resistance of the draw down film from the formulations from TABLE 1 on cold roll steel and zinc phosphatized steel substrates at various bake temperatures. (A coating of film which withstands 100 MEK double rubs is considered cured). In all cases the formulations that contain metal catalysts cure much better than those without the metal catalyst. The cure temperature is significantly lower.
As the melamine-formaldehyde resins are replaced with urea/formaldehyde resins, e.g., Beetle® 60 or Beetle® 65 of American Cyanamid, the cure temperature in all cases has also been significantly reduced when an appropriate metal catalyst is utilized versus the same system without a metal catalyst. The cure film of either system above has also exhibited good solvent resistance and good adhesion to metal.
Formulation No.2 from Table I can be made into a cathodic dispersion as follows:
______________________________________Ingredient Solids Grams______________________________________Amino Epoxy resin of 141.4 235.6Ex. I-BCymel ® 1158 48.2 60.3Synfac 8029 ® .sup.(1) 0.9 0.9Lead Octoate/24% Lead 5.5 8.5(Nuodex ® 24% Lead)Formic Acid/90% 5.3Deionized Water 690.3Total 1,000.9______________________________________ .sup.(1) Propoxylated Bisphenol A from Milliken Chemical Co. formed by Reacting one mole of bisphenol A with two moles of propylene oxide.
The amino epoxy resin, Cymel ® 1158, Synfac 8029 ®, lead octoate and formic acid were premixed in a container equipped with an agitator for one-half hour. Then the deionized water was very slowly introduced with good agitation until the mixture was inverted or emulsified to aqueous dispersion. The initial pH was about 7.5 with a conductivity of about 2.8 micro-mHOs per cm.
After the above cathodic dispersion was agitated in an open can overnight, several cold roll steel and zinc phosphatized metal panels were cathodically electrocoated in the dispersion and then the panels were baked in an oven at various temperatures for 30 minutes. It has been found that the coated film of about 0.6 to 1.2 mil did cure at 120° C. The cured film did not soften after 100 MEK double rubs. It has good wet adhesion to metal and good corrosion resistance with a creepage of 1 mm after 1000 hours salt spray exposure.
TABLE I__________________________________________________________________________Formulations of Amino Epoxy ResinUsing Various Aminoplasts and Metal CatalystsParts by Wt. Parts by Weight - Metal CatalystFor- Amino Epoxy Nuodex ® Nuxtra ®Δ Nuodex ®mula- Resin Parts by Weight - Aminoplast Lead Synthetic Copper Nuxtra ®.DELT A.tion Ex I-B (at Cymel ® 1158* Cymel ® 373+ Cymel ® 303# Octoate Drier (12% Octoate 12%No. 65% Solids) 80% Solids 85% Solids 98% Solids (24% Pb) Cobalt) (8% Copper) Iron__________________________________________________________________________1 25.0 6.4 No Catalyst2 25.0 6.4 0.93 25.0 6.4 1.84 25.0 6.4 2.75 25.0 6.4 1.86 25.0 6.0 -- --7 25.0 6.0 0.98 25.0 6.0 1.89 25.0 6.0 2.710 25.0 6.0 1.811 25.0 5.2 -- --12 25.0 5.2 0.913 25.0 5.2 1.814 25.0 5.2 2.715 25.0 5.2 1.8__________________________________________________________________________ *Trademark of American Cyanamid Co. for their butylated, high imino (--NH melamineformaldehyde resin +Trademark of American Cyanamid Co. for one of their partially methylated melamineformaldehyde resins #Trademark of American Cyanamid Co. for one of their highly methylated melamineformaldehyde resins ,ΔTrademarks of Huls America Inc. for their line of metal driers o soaps based on naphthenates, octoates, and synthetic esters
TABLE 2__________________________________________________________________________SOLVENT RESISTANCE* OF VARIOUS COATINGSBAKED AT VARIOUS TEMPERATURES FOR 30 MINUTES Substrate Cold ** No. of MEK Double Rubs atFormulation Zinc Roll Application Various Bake Temperature - °F.No. Phosphatized Steel Draw Down 225 250 300 350 400__________________________________________________________________________1 Yes Yes 83 100 >1001 Yes yes 52 100 >1002 Yes Yes 100 100 >1002 Yes Yes 100 >100 >1003 Yes Yes >100 >100 >1003 Yes Yes >100 >100 >1004 Yes Yes >100 >100 >1004 Yes Yes >100 >100 >1005 Yes Yes >100 >100 >1005 Yes Yes >100 >100 >1006 Yes Yes 100 >100 >1006 Yes Yes 100 >100 >1007 Yes Yes >100 >100 >1007 Yes Yes >100 >100 >1008 Yes Yes >100 >100 >1008 Yes Yes >100 >100 >1009 Yes Yes >100 >100 >1009 Yes Yes >100 >100 >10010 Yes Yes >100 >100 >10010 Yes Yes >100 >100 >10011 Yes Yes 30 100 >10011 Yes Yes 26 100 10012 Yes Yes 80 >100 >10012 Yes Yes 72 >100 >10013 Yes Yes 30 >100 >10013 Yes Yes 100 >100 >10014 Yes Yes 45 100 >10014 Yes Yes 80 >100 >10015 Yes Yes >100 >100 >10015 Yes Yes >100 >100 >100__________________________________________________________________________ *Solvent resistance of cured or baked film is defined as the film remains intact after MEK solvent rubs. ** Drawdown film using 2.4 mil doctor blade using solution formulation at about 40% solids which gives a cure film thickness of approximately 1.0 mil.
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A low cure cathodic electrodepositable resin is disclosed. The backbone of the resin is a polyepoxide amine adduct which is crosslinked with aminoplast resins and catalyzed by metal catalysts. The resin is capable of curing in a basic environment at a temperature below 150° C. The resin can be salted with an acid and can be dissolved or dispersed in water. The aqueous dispersions can then be formulated into electrocoat primer coatings for metal objects.
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BACKGROUND OF THE INVENTION
The reaction of amines with phosgene to produce isocyanates is well known. The reaction may be represented by the following general reaction: ##STR1## In the course of the reaction the intermediate carbamyl chloride is formed which has a tendency to react under normal reaction conditions to produce urea and tars which detract substantially from the yield of the desired isocyanate. To avoid the formation of these side products several improvements in the phosgene preparation of isocyanates have been proposed.
One prior art method calls for a two-stage process, the first stage entails the formation of a slurry of intermediates at temperatures ranging from 0° C. to room temperature and subsequently reacting the intermediate products with phosgene at temperatures high enough to convert the intermediate to the isocyanate, usually in the range of 160° to 200° C. This procedure presents processing difficulties due to the release of large amounts of phosgene when the temperature is elevated in the course of the reaction.
Another prior art method is that of U.S. Pat. No. 2,908,703 wherein efforts to minimize by-product formation are by means of a two-stage procedure involving a first stage reaction at a temperature of from about 60° C. to about 90° C. and a second stage wherein intermediate product from the first stage are further reacted.
Still another method attempted is that of U.S. Pat. No. 3,226,410 wherein the patentees describe a continuous process for producing diisocyanates aimed at minimizing backmixing by reacting the phosgene with a dilute stream of the amine carried in an inert organic diluent under superatmospheric pressure in a controlled turbulent flow. None of the known prior art methods have sufficiently reduced the undesirable by-product formation. There is thus a need for a suitable method to increase the yield by minimizing by-products in the manufacture of diisocyanates.
SUMMARY OF THE INVENTION
In accordance with the invention a novel plug flow reactor and process is provided to eliminate backmixing at the feed mixing zone and facilitate the production of diisocyanates with a minimum of undesirable by-products. With the method and arrangement of the invention plugging is essentially eliminated in the reactor mixing zone.
In accordance with the invention, the pluggage in the reactor mixing zone identified as being primarily carbamyl chloride, the intermediate product in the isocyanate reaction is essentially eliminated by regulating the wall temperature of the reactor mixing zone. By thus controlling the temperature, timely and essentially complete conversion of the carbamyl chloride to the desired diisocyanate product takes place before the carbamyl chloride is able to deposit on the wall of the reactor resulting in pluggage of the reactor.
Thus the present invention includes a method of continuously preparing aromatic isocyanates by reacting phosgene in a reactor with an aromatic primary amine under conditions in which an intermediate carbamyl chloride is formed, regulating the reactor wall temperature by supplying sufficient heat to the reactor wall to counteract the cooling effect of additional amounts of phosgene reactant on said intermediate and, by said supplied heat, sustaining the reactor wall at a temperature at which the carbamyl chloride decomposes to aromatic isocyanate and above the reaction temperature prevailing during the formation of said carbamyl chloride, thereby preventing solidification of carbamyl chloride at the reactor wall and producing the desired aromatic isocyanate from the carbamyl chloride.
Regulation of the reaction of the carbamyl chloride in accordance with the invention is effected by controlling the wall temperature and thereby the temperature at which the carbamyl chloride is exposed in the reactor. Preferably a steam jacket is employed for this purpose.
Based on these heat transfer calculations and the fact that carbamyl chloride decomposes to the diisocyanate at temperature of about 90° to 140° C. heating of the reactor wall has been found to prevent pluggage of the reaction zone and undesirable by-product formation while only practical considerations impose an upper temperature limit, generally temperatures between about 90° C. and about 200° C. may be employed.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a flow diagram illustrating a preferred scheme for production of diisocyanate utilizing the improved reactor arrangement and process of the invention.
FIG. 2 is a vertical schematic cross-sectional illustration of a reactor of the kind employed in the process of the invention wherein the isocyanate is formed from the phosgene and aromatic amine.
FIG. 3 is a flow diagram similar to FIG. 1 illustrating an alternate scheme in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the description which follows toluenediamine (TDA) will be employed as a typical aromatic amine in describing the invention. However, it will be apparent that various other aromatic amines may also be employed while still retaining the advantages of the invention.
According to the present invention phosgene and an inert organic solvent solution of a primary aromatic amine are reacted together, initially at a temperature between about 60° C. and about 90° C. and subsequently by means of the heat of reaction and secondary backmix reactors. The intermediate reaction mixture is subjected to an elevated temperature sufficiently high to convert the intermediate product to the isocyanate before it can be exposed to reduced temperatures which generate undesirable by-products from the intermediate carbamyl chloride. In the process, aromatic isocyanates are prepared by reacting phosgene with an aromatic primary amine under conditions in which an intermediate carbamyl chloride is formed. Sufficient heat is supplied to the reaction to counteract the cooling effect of the phosgene. The reactor wall temperature is sustained above the temperature prevailing during the subsequent reaction between the carbamyl chloride and phosgene which produces the desired isocyanate.
In a representative embodiment of this invention, a dilute solution of the aromatic amine in an inert organic solvent, such as dichlorobenzene, is passed into the first reactor. Concomitant with the addition of amine solution to the first reactor, phosgene liquid from any convenient source is also admitted to the reactor through a separate entry point. The mass in the reaction vessel is preferably well agitated and sufficient heat is supplied via the exothermic heat of reaction of the amine with phosgene to maintain the preferred temperature for phosgenation.
Preferably, the solution of the amine and the phosgene are introduced at such rates that there is at least a 50% stoichiometric excess of phosgene over that theoretically required to react with the amine.
The process of the invention is preferably carried out continuously and is described by reference to the drawing wherein primed reference numbers are applied in FIG. 3 corresponding, where applicable, to similar components in FIG. 1 bearing the same reference numbers without prime designation.
In the drawing, 24 is a feed tank for the liquid phosgene, provided with the feed line 17 which feeds reactor 10 with the phosgene feed. In FIG. 3, 25 is a feed tank for a solution of phosgene and solvent with a feed line 25' which mixes with the liquid phosgene from line 17' and then fed via line 28' to reactor 10'. 23 and 23' are feed tanks for the amine and 22 and 22' are the solvent feed tanks. The amine fed from line 15 or 15' mixes with the solvent of line 14 or 14' is fed to reactor 10 or 10' via line 16 or 16'. The amine solvent mixture of line 16 or 16' contacts either the phosgene liquid from line 17 or the phosgene and phosgene solvent mixture from line 25' and 17' in the mixing zone 29 of reactor 10. In order to assure good mixing in reactor 10 without backmixing, reactor 10 is sized such that the velocity of stream 28' or 17 in the reactor annular space 30 is lower than the velocity of stream 16 or 16' in the feed tube 31. A velocity ratio of 2.6 to 1 assures good mixing while minimizing backmixing. A heating jacket 11 is provided to maintain the reactor wall temperature above 90° C. to avoid pluggage of the reaction zone. In the heating jacket steam as the heating medium is chosen for convenience, but any suitable heating method can be used such as hot oil in the jacket or heat tracing, steam tracing or electrical tracing, for example. The reaction mass containing a mixture of solvent, intermediate product and isocyanate product is fed through lines 26 or 26' continuously to two secondary backmixed agitated reactors 12, 27 or 12', 27' (FIGS. 1 and 3 respectively) maintained at a temperature of 110° C. to 155° C. to complete the reaction to the desired isocyanate. Excess phosgene and by-product hydrochloric acid are removed from reactors 12, 27 or 12', 27' as a gas, the majority of the phosgene is condensed in condenser 18 or 18' and sent from tank 20 or 20' to the phosgene feed tank 24 or 24' for reuse. The gas stream exits through tank 20 or 20' via line 19 or 19' for further processing to recover the remaining phosgene for reuse and HCl by-product. The reaction mass from reactor 27 or 27' is sent to product purification via line 32 or 32'.
Various aromatic amine primary may be converted to the corresponding isocyanate by this process. The amine may be a monoamine, a diamine or some other polyamine. Examples of aromatic amines which may be used in the practice of this invention are aniline, the isomeric toluidines, the isomeric xylidines, o-, m-, and p-alkylanilines, o-, m-, amd p-chloroanilines, the isomeric dichloroanilines, the isomeric phenylenediamines, the isomeric diaminotoluenes, the isomeric diaminoxylenes, various diaminoalkyl benzenes, alpha- and beta naphthylamines, the isomeric diaminonaphthalenes, the isomeric bisaminophenylmethanes, the isomeric trisaminophenylmethanes, the dianisidines the diaminodiphenyls and mixtures of these amines. The amine should be free of groups which would interfere with the reaction between the amino group and phosgene or with the isocyanate radical, that contain active hydrogen atoms. Such groups are, for example, --OH, --COOH, --SH, etc. The most preferred diamine is toluenediamine.
The initial temperatures of phosgenation employed in this invention range from about 60° C. to about 90° C. The preferred temperatures in this range are from 65° to 80° C.
30 pounds per square inch gage pressure is normally employed as a matter of convenience, though higher or lower pressure may be used.
The solvents employed in this process are those which are inert to the reactants and products. Although aliphatic and aromatic hydrocarbons which are inert to the reactants and products, are satisfactory solvents, the preferred solvents are the chlorinated hydrocarbons. Representative members of this class are monochlorobenzene, dichlorobenzene, carbon tetrachloride, the corresponding chlorinated toluenes and xylenes and trichloroethylene. The most preferred solvent is dichlorobenzene. It is desirable and preferable to choose a solvent that boils lower than the isocyanate product.
The amine may be introduced into the reaction vessel in solution in the chlorinated hydrocarbon solvent. Concentrations of the amine may be varied from about 2 to 20% by weight of the solution. The reaction will proceed at lower concentrations; however, lower concentrations result in uneconomically low volume productivities. Higher concentrations of the amine lead to formation of undesirable side products, i.e., urea, substituted ureas, polyureas and tar compounds The preferred range of the amine solution is 5 to 10% by weight of amine.
The concentration of phosgene in the reaction solution is regulated by the temperature being employed for the reaction. Preferably, an essentially saturated solution of phosgene in the solvent should be maintained at all times during the reaction. Low concentrations of phosgene result in decreased efficiencies, due to formation of side products. The use of greater amounts of phosgene does not adversely affect the efficiency of the operation. However, it will be apparent that precautions must be taken to handle the excess phosgene and, thus, large excesses of phosgene are to be avoided.
The advantages and mode of carrying out the process of this invention are further illustrated by the following representative examples:
EXAMPLE I
Referring to FIGS. 1 and 2, 100 pounds per hour of toulenediamine are mixed with 900 pounds per hour of dichlorobenzene at 60° C. and sent to reactor 10. Simultaneously, 365 pounds per hour of phosgene at 0° C. is pumped to reactor 10. Reactor 10 is so sized that a velocity ratio of 2.6 to 1 is maintained between the toluenediamine, dichlorobenzene mixture and the phosgene entering the reaction zone 29.
The reaction proceeds adiabatically with the reaction mass exiting the reactor at a temperature of 110° C. via stream 26. Steam is added to the jacket at point 33 to maintain the wall temperature of reactor 10 at 90° C. The reactor 10 is run at a pressure of 30 psig.
The reaction to the diisocyanate is completed in reactor 12 and 27. Reactor 12 being maintained at 110° C. and reactor 27 being maintained at 145° C. Phosgene and by-product HCl along with trace amounts of product isocyanate are taken overhead in stream 13. Stream 13 consists of 182.6 pounds per hour phosgene and 116.6 pounds per hour HCl. The phosgene is recovered from the HCl by condensation and 182.6 pounds per hour are sent to tank 20. 116.6 pounds per hour of HCl is recovered as aqueous HCl in standard equipment. 1065.8 pounds per hour of reaction products are removed via line 32. This reaction product consists of 3.1 pounds per hour HCl, 20.3 pounds per hour phosgene, 900 pounds per hour dichlorobenzene, 130.5 pounds per hour toluene diisocyanate and 11.9 pounds of reaction by-product. The product toluene diisocyanate is purified by fractional distillation. The yield of toluene diisocyanate is approximately 91% based on the amine.
EXAMPLE II
Referring to FIGS. 2 and 3, 100 pounds per hour of toluenediamine are mixed with 540 pounds per hour of dichlorobenzene at 60° C. and sent to reactor 10'. Simultaneously, 301 pounds per hour of phosgene is mixed with a solution containing 360 pounds per hour dichlorobenzene and 64 pounds per hour phosgene and is sent to reactor 10' via line 28. The mixture is at 0° C. Reactor 10' is so sized such that a velocity ratio of 2.6 to 1 is maintained between the toluenediamine, dichlorobenzene mixture and the phosgene, dichlorobenzene mixture entering the reaction zone 29.
The reaction proceeds adiabatically with the reaction mass exiting the reactor at a temperature of 110° C. via stream 26. Steam is added to the jacket at point 33 to maintain the wall temperature of reactor 10 at 90° C. The reactor 10' is run at a pressure of 30 psig.
The reaction to the diisocyanate is completed in reactor 12' and 27'. Reactor 12' being maintained at 110° C. and reactor 27' being maintained at 145° C. Phosgene and by-product HCl along with trace amounts of product isocyanate are taken overhead in stream 13'. Stream 13' consists of 182.6 pounds per hour phosgene and 116.6 pounds per hour HCl. The phogene is recovered from the HCl by condensation and 182.6 pounds per hour are sent to tank 20'. 116.6 pounds per hour of HCl is recovered as aqueous HCl in standard equipment. 1065.8 pounds per hour of reaction products are removed via line 32'. This reaction product consists of 3.1 pounds per hour HCl, 20.3 pounds per hour phosgene, 900 pounds per hour dichlorobenzene, 130.5 pounds per hour toulene diisocyanate and 11.9 pounds of reaction by-product. The product toluene diisocyanate is purified by fractional distillation. The yield of toluene diisocyanate is approximately the same as Example I based on the amine.
It will be apparent that various changes may be incorporated in the foregoing procedure without departing from the scope of the invention and that unless specifically limited in the appended claims the details supplied in the description as shown in the drawing are to be interpreted as illustrative and not limiting.
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The reaction of aromatic amines with phosgene takes place in the mixing zone of a plug flow reactor to form both the product isocyanate as well as the intermediate carbamyl chloride. The aromatic amine dissolved in an inert diluent is fed to the center portion of the plug flow reactor while the phosgene is fed to the annular space. The reactor is designed so as to eliminate back-mixing at the feed zone and thus to avoid reaction of any isocyanate formed with the incoming aromatic amine which produces in turn undesirable by-products such as urea and tar. Cold phosgene that is fed into the annular space cools the wall sufficiently to inhibit the reaction to TDI. By heating the wall such as with the installation of a heating jacket to counteract the cooling effect of phosgene, the wall of the reactor is maintained above 90° C. and thus any solid carbamyl chloride that migrates to the wall is reacted to the isocyanate, eliminating pluggage of the reactor from solids build-up.
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BACKGROUND OF THE INVENTION
The present invention relates to a method of automatically adjusting thread tension in a sewing machine.
The prior art belonging to this field will be explained in reference to the attached drawings. With respect to the thread tension, taking the tension of the upper thread, for example, it is preferable to make adjustments for thin fabric materials, middle materials and thick materials in proper ranges of the thread tension as shown with arrows in FIG. 1. It is in general required to increase the tension as thickness of the fabric becomes large and as hardness becomes high.
For automatically responding to these characteristics of the fabric, there has been proposed an adjustment of an electric driving part of the thread tension device in accordance with the data of the fabric thickness. However, for the fabric hardness, there have not been any measures.
SUMMARY OF THE INVENTION
This invention is to adjust the thread tension in response to load subjected on a needle bar when a needle penetrates the fabric material, thereby to automatically provide exact thread tension.
The load is detected by the premise that the load is relative to the characteristics of the fabric thickness and hardness. The detection is made in that electric current of the load on a motor driving a main shaft of the sewing machine is momentarily increased at the penetration, or in that an electric driving part of the thread tension device is controlled by deviation signals expressed with deviation between ordinary speed designating signals (corresponding to objective values of the speed) and speed feedback signals (corresponding to surveyed values of the speed), or by signals from a stress detector provided on the needle bar or others.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the relationship between the thickness of the fabric and the proper thread tension;
FIG. 2 shows a control circuit of an embodiment of the present invention;
FIG. 3 shows waves of current of load on a motor (MS) driving a main shaft of a sewing machine in the control circuit of FIG. 2;
FIG. 4 is a block diagram of the speed control in the control circuit of FIG. 2; and
FIG. 5 is a perspective view showing the attachment of a stress detector to a needle bar.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 2, a microcomputer is composed of a central processing unit (CPU), a read-only-memory (ROM), a read-access-memory (RAM) and an input-output port (I/O).
The sewing machine is, though not shown, provided with a driving part for controlling stitchings, which is controlled by the above mentioned microcomputer for producing desired stitching patterns. A motor (SM) for driving a main shaft of the sewing machine is provided with an armature (A) and a series field (FC), and is connected to a commercial power source (AC). The load current is effected with a full wave phase control by mixed bridge comprising diodes (D1)(D2) and thyristors (SCR1) (SCR2).
A gate controller (CC) makes an ignition phase control on the thyristors (SCR1) (SCR2) in accordance with signals processed as later mentioned from the central processing unit (CPU). A machine controller (CONT) designates the speed of the main shaft driving motor (SM), and gives digitalized designation signals to the central processing unit (CPU). A speed detector (SD) is provided on the main shaft (not shown) of the sewing machine for issuing and giving pulse signals of numbers in proportion to the rotation speed of the main shaft to the central processing unit (CPU), and feeding back the speed signal.
A transformer (TF) for detecting the load current supplies the current wave of the main shaft driving motor (SM) to a pick-up circuit (PU) and transmits the waves of the full wave controlled currents as shown in FIG. 3 for driving the sewing machine. The pick-up circuit (PU) rectifies the input signal wave in accordance with an order from the central processing unit (CPU) and holds peak values (P1) (P2) (P3) (P4) shown in FIG. 3 which are produced when the needle passes the fabric, and issues a read order of peak hold in synchronism with the phase penetrating the needle through the fabric, in response to the signal of a detector (PDp) of needle moving phase provided on the main shaft of the sewing machine.
Analog-digital converter (A/D) converts the peak hold value into a digital signal, and supplies it to the central processing unit (CPU). DC motor (DM) is controlled by a driver (DV) to adjust the upper thread tension effected by a thread tension device 1, and rotates a gear 3 secured on a thread shaft 2 to axially move an actuator 4 screwed on the shaft 2 for controlling the pressure exerted by thread tension discs 5 holding a thread. The driver (DV) rotates DC motor (DM) forward and backward and stops it in response to signals (+)(-) and (STOP) issued from a comparison circuit (COMP) for the period of issuing the signals.
A pulse generator (PG) issues pulse signals in proportion to the rotation or the rotation phase angle of the shaft 2, and and supplies these signals to a polarity discriminating circuit (Z). In combination of the signals (+)(-) of the comparison circuit (COMP) and the signals of the pulse generator (PG), and when the combination is the signal (+), the circuit (Z) counts up (UP) counting of a counter (COUNT) per each of the signals from the pulse generator (PG), and when it is the signal (-), the circuit (Z) counts down (DOWN).
The comparison circuit (COMP) is supplied with digital data for setting the thread tension at the starting of the sewing machine when the control power source is supplied, or digital data for setting the thread tension during driving of the sewing machine (called "thread tension designation data X" hereinafter) from the central processing unit (CPU), and the comparison circuit is supplied with the counting data for setting the thread tension at the starting of the driving of the sewing machine when the control power source is supplied, or the counter data counted by this data (called "counting data Y" hereinafter), from the counter (COUNT). These data X and Y are compared, and the case of Y<X, the signal (+) is the output, and in the case of Y>X, the signal (-) is output, and in the case of Y=X, the signal (STOP) is the output.
The next explanation will be concerned with actuation of the above mentioned structure. When the control electric source is supplied, the control circuit shown in FIG. 2 starts to work. The comparison circuit (COMP) is supplied with binary data 0 0 0 0 as an initial value of the data X from the central processing unit (CPU), and supplied with binary data 1 1 1 1 as an initial value from the counter (COUNT). Since Y>X is obtained, the comparison circuit (COMP) issues an output of the signal (-) to the driver (DV), so that the DC motor (DM) is reversely rotated and the actuator 4 of the thread tension device 1 is moved to the right side in FIG. 2 to loosen the thread tension.
The counter (COUNT) is successively counted down, and when Y=X is obtained the comparison circuit (COMP) outputs the signal (STOP) and the DC motor (DM) is stopped. During this period the actuator 4 engages a stopper (not shown) and stops at a scale 0 of the thread tension. The DC motor (DM) is idle in rotation after engagement, and the initial setting is finished by this stopping. On the standard of the initial setting position where the thread tension device 1 of X at the finishing being 0 0 0 0 and the DC motor (DM) are combined, the following thread tension is controlled.
Subsequently, the central processing unit (CPU) issues a determined value, e.g., X=0 0 1 0, as a standard setting value of the thread tension. When Y<X is obtained, the comparison circuit (COMP) outputs the signal (+), so that the DC motor (DM) is normally rotated and the actuator 4 moves to the left in FIG. 2 to increase the thread tension. When the counter (COUNT) is counted up by 2, Y=X is obtained and the DC motor (DM) is stopped. The thread tension at this time of the thread tension device 1 is set at the standard.
The fabric is set on the sewing machine and the machine controller (CONT) is operated to drive the sewing machine by designating, e.g., the low speed. The current waves of the load effected with the full wave control of the motor (SM), which is given to the pick-up circuit (PU) via the transformer (TF), are as shown in FIG. 3. Since friction resistance is large when the sewing machine starts to rotate, the load of the needle bar is increased and current value (I) becomes remarkably large to generate a peak (Ps) at the beginning of rotation. Since the friction resistance is decreased as time (t) passes, an evnelope (E) of the waves effected with the full wave control rapidly falls. After passing a transient period (A), the rotation speed of the sewing machine goes up as the time (t) passes by successively moving from the low speed designation to the high speed designation by means of the controller (CONT) and the envelope (E) also goes up. When the needle passes through the fabric per each of the rotation period (T) in an interval (B) of relatively low speed, the load of the needle momentarily increases due to the friction resistance, so that the current of the load increases accordingly and each of the peak values (P1) (P2) (P3) (P4) appears. The larger are these peak values, the thicker and the harder is the fabric. When the rotation speed of the sewing machine becomes higher, and enters an interval (C) of relatively higher rotation speed, these peak values do not appear, even if the load of the needle bar increases momentarily by inertia of the rotation, because the rotation speed of the sewing machine is equalized so that the load of the motor driving the main shaft is hardly changed.
As is seen from the above, in this invention, a calculation is made on each of the peak values (P1) to (P4) in the interval (B) having interrelation with the fabric characteristics, and the thread tension is controlled with the results of this calculation.
The pick-up circuit (PU) outputs the peak values (P1) to (P4) whose peaks are held, and these values are converted into the digital values by means of the analog-digital converter (A/D) and given to the central processing unit (CPU). The central processing unit (CPU) makes a calculation in the interval (A) for starting rotation of one or two stitchings by means of the signal from a speed detector (SD), and does not adopt the peak (Ps). Thus, the stitching is begun at the thread tension which has been in advance determined at the standard. The thread tension is not required to be of a high precision at the beginning of rotation.
The peak values (P1) to (P4) in the interval (B) of the normal low rotation are amended by the central processing unit (CPU), or judged successively as to whether the normal values or noises, or calculated to obtain mutual average values, so that these results are stored in the random-access-memory (RAM) as data ranking the fabric characteristics and are re-written appropriately.
The read-only-memory (ROM) stores the data X of designating the thread tension in response to the data of the fabric characteristics, and the data X are newly output instead of X=0 0 1 0. If the new data X is different from the previous condition, and since it is different from the counting data Y from the counter (COUNT), the comparison circuit (COMP) actuates and the thread tension device 1 is controlled to the thread tension based on a new data X. In the interval (C) of the comparatively high speed, the central processing unit (CPU) makes the calculation from the speed signal and does not adopt each of the peak values, but adopts the last data X in the interval (B), so that the thread tension based on this data is maintained, while the controlling electric source is continuously supplied the last data X is adopted also in the interval (A), so that this thread tension is maintained.
A further reference will be made to another embodiment where the thread tension is controlled by detecting the load of the needle bar not depending on the load electric current but depending on the speed controlling signal of the motor driving the main shaft of the sewing machine.
In the control circuit in FIG. 2, a speed control system of the motor (SM) driving the main shaft of the sewing machine may be simplified as shown in FIG. 4. A digital signal Cs(t) (t is for time) corresponding to the speed objective value is supplied to one of the terminals of the comparator (CP). The rotation period calculator (SR) counts the signal of the speed detector (SD), and supplies to the other terminal of the comparator (CP) the digital signal Cn(t) based on the counting value per unit time of the counted signal. The comparator (CP) compares these digital signals, and deviation signal ΔCn(t)=Cs(t)-Cn(t) is calculated per each small period of time t and gives it to an ignition time calculator (AT).
The ignition time calculator (AT) amends a new ignition phase in accordance with the deviation signal ΔCn(t) with respect to the present ignition phase for the gate controller (CC), and produces a negative feedback in order to lower the next deviation signal ΔCn(t). In the present invention, this deviation signal ΔCn(t) is amended in the speed similarly as in the previous embodiment and is stored as the data ranking fabric characteristics in the random-access-memory (RAM). If the rotation of the sewing machine rapidly decreases concerning the speed designation due to the rapid increase of the load of the sewing machine or for other reasons, the deviation signal ΔCn(t) increases to amend this rapid decrease as the peak values (P1) to (p4) in FIG. 3. In such a manner, the data X for designating the thread tension in response to the data of the fabric characteristics is stored in this embodiment, so that the thread tension is controlled as mentioned above. The present case does not need the transformer (TF) and the pick-up circuit (PU).
A further explanation will be made to a method of adjusting the thread tension by detecting the load on the needle bar by means of a stress detector. In FIG. 5, the needle bar 6 is secured with an elastic member 8 of U shape serving to hold the needle 7 and is provided with a stress gauge 9 in a bottom of an inner side. With respect to the stress gauge 9, leads 10 pass through the hollow needle bar 6 and reach sliding plates 12 which are insulated from each other. Brushes 11 contacting the sliding plate 12 issue detected values, and these values are amplified or digital-converted and given to the central processing unit (CPU). The stress gauge 9 detects the stress of the elastic member 8 when the needle 7 penetrates the fabric, and the detected data are stored in the random-access-memory (RAM) as data ranking the fabric characteristics. The data X for designating the thread tension in response to the data of the fabric characteristics are read out to adjust the thread tension. This case adopts all of the detected data all over the intervals (A), (B), (C).
As having mentioned above, according to the invention, the fabric characteristics concerning the thread tension are detected with respect to the thickness and hardness of the fabric to automatically adjust the thread tension without being troublesome, so that the thread tension suitable to each of the fabric characteristics may be obtained.
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A method of automatically adjusting thread tension in a sewing machine including detecting changes of load subjected on the needle bar caused when the needle penetrates the fabric to be sewn and adjusting the electric driving part of the thread tension device in accordance with the values of the changing components of the load.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No. 10/617,196, filed Jul. 9, 2003 now U.S. Pat. No. 6,938,857, which is a continuation of U.S. application Ser. No. 07/457,053, filed Dec. 26. 1989, and issued Aug. 12, 2003 as U.S. Pat. No. 6,604,708.
This invention relates to a method and means for increasing the life of carbon aircraft brakes. More particularly, this invention relates to the controlled application of braking pressure to only selected brakes during low speed ground travel.
BACKGROUND
Modern aircraft which are designed to carry large passenger or cargo payloads are often provided with carbon brakes on each of the wing or body mounted wheels. The nose wheel is typically not braked. Carbon brakes are preferred because of their light weight and performance characteristics and generally comprise a piston housing and parts, a torque plate and a carbon heat sink stack. This stack contains all the friction surfaces which, when compressed, cause the wheel to decrease its speed. The stack comprises a pressure plate, rotor disks, stator disks and backing plate. Carbon composite rotors are connected to the wheel through the rotor drive keys and turn with the wheel. Carbon composite stators, pressure plates and backing plate are connected to the torque tube and do not turn. Braking friction is caused when the rotors are compressed against the stators.
While carbon brakes are preferred for weight and performance reasons over steel brakes, the cost of replacing the stack divided by the number of landing cycles between replacements is much higher than for steel brakes.
Aircraft brake control systems are designed with separate pedal controls for the left and right brakes. When one of the brake pedals is depressed, all the brakes on that side of the aircraft are commanded to apply simultaneously and equally. By applying all brakes equally, the heat energy absorbed by each individual brake is minimized. For steel brakes, brake life is largely determined by the total amount of energy absorbed by each brake and is largely unaffected by the number of brake applications that accumulate that energy. Hence, brake control systems that apply all brakes simultaneously and equally provide economic operation of steel brakes and minimize exposure to overheating of any individual brake. However, direct application of this method to carbon brakes does not extend and may significantly shorten their lives. Accordingly, this invention provides a novel method and means to extend the life of carbon brakes and substantially reduce their operating cost.
BRIEF SUMMARY
In accordance with the invention carbon brake life is significantly extended by decreasing the number of brake applications during each landing cycle. More particularly, brake wear has been found to correlate significantly with the number of brake applications and to not be significantly affected by the energy absorbed during each. By far the largest number of brake applications occur during ordinary taxiing, so in preferred embodiments of this invention, only some of the brakes are applied in response to brake applications under ordinary taxiing conditions. An alternating wheel braking pattern is established to minimize brake wear at each braked wheel and yet to promote even distribution of absorbed energy among all the brakes. This, in turn, prevents overheating of any individual brake. The extended brake-wear system is activated only when aircraft ground speed and brake application pressures are typical of taxi operations. Preferably, aircraft speed and hydraulic pressure are sensed so that brakes at all wheels will be operative in critical braking situations such as landing, parking, or emergency stopping.
The invention will be better understood in terms of the Figures and detailed description which follow.
DETAILED DESCRIPTION
FIG. 1 is a simplified schematic of a subsystem for aircraft brakes which alternately disables one of two brakes in order to limit the number of brake applications and extend carbon brake life.
FIG. 2 is a schematic view of a sixteen wheel and brake landing gear configuration for a wide bodied aircraft showing a brake disable circuit which would be activated under low braking pressure and aircraft speed conditions representative of taxi braking to disable half the brakes and thereby extend brake life.
For carbon brakes, the landings to wear-out ratio is strongly dependent on the number of brake applications rather than the energy absorbed by a brake during each application. For commercial passenger aircraft, the brakes may be applied an average of twenty times per landing cycle. The brakes are generally applied during landing absorbing several million foot-pounds for heavy wide-bodied aircraft and once to stop the wheels from spinning before they are retracted after take-off. Both of these are “high speed” brake applications, and are typically at moderate hydraulic pressures less than about 1500 psi hydraulic pressure. The balance of the brake applications are “taxi snubs” for steering or low speed braking. They create hydraulic brake fluid pressures generally less than about 1500 psi and absorb about 0.5 MFP average per snub for wide-bodied aircraft. These taxi snubs account for a significant amount of brake energy temperature buildup, and for carbon brakes, most of the wear since carbon brake wear is dependent on the number of brake applications. Occasionally, “emergency” brake applications may be made at higher pressures (up to 3000 psi hydraulic fluid pressure), but such emergency braking is an insignificant wear factor.
Conventional brake wear control systems provide for applying all brakes equally, gently, and simultaneously during normal taxi braking. In accordance with a preferred embodiment of this invention, the life of carbon brakes is extended by minimizing the number of brake applications while distributing the heat energy absorbed substantially equally among all the brakes. This is accomplished by alternately applying only a selected number of brakes rather than all the brakes during each normal taxi braking operation.
A simplified example of a preferred embodiment of this invention is shown schematically in FIG. 1 . A left wheel 2 and right wheel 4 are on the same side of an airplane and are actuated by the one of the two brake pedals in the cockpit. Wheel 2 has a carbon brake 6 and right wheel 4 a carbon brake 8 . In this embodiment, the antiskid control system 10 is integral to the brake disable system. Left and right wheel speed sensors 12 and 14 , electronically measure wheel speeds and input the signals generated to the antiskid control circuit 10 . Signals from antiskid control circuit 10 are outputted through diodes 16 and 18 to left and right hydraulic antiskid valves 20 and 22 . The signals from wheel speed sensors 12 and 14 are integrated by antiskid control circuit 10 and outputted to brake disable control circuit 24 .
Brake metering valve 26 which is responsive to a call for braking from the cockpit is located in brake hydraulic line 28 . The static line pressure is low, pressure during taxi snubs is higher, and pressure during parking and emergency braking is relatively higher still. This pressure is measured at metered brake pressure sensor 30 . The signal from sensor 30 is inputted to brake disable control circuit 24 .
The system works in accordance with the invention as follows. The speeds of wheels 2 and 4 are sensed through sensors 12 and 14 and processed in antiskid control circuit 10 to determine aircraft speed. That aircraft speed signal is inputted to brake disable circuit 24 . The desired intensity of braking action is sensed by the metered brake pressure sensor 30 and is also inputted to brake disable circuit 24 . Inside brake disable control circuit 24 , the metered pressure signal is compared against a first predetermined value, 100 psi for example, to detect when a brake application has been commanded. At the moment at which a brake application is detected, a comparison is made between the aircraft speed signal and a predetermined value for aircraft speed in brake release logic circuit 32 . If the speed is higher than the predetermined value, 40 mph, for example, then brake disablement is not enabled. Subsequently, comparison is continuously made inside brake release logic 32 between the metered pressure signal value and a second predetermined value. If the pressure is greater than the second predetermined value, greater than 1500 psi, for example, then the brake disable control circuit 24 does not disable any brakes. That is, if heavy braking intensity is called for, all the brakes are applied. If and only if aircraft speed at the time of brake application and metered brake pressure are lower than their predetermined maximum values will brake release logic circuit 42 be activated.
As indicated by bipolar knife switch 36 , only one of the two antiskid valves 20 and 22 will be commanded to release its respective brake through left diode 38 or right diode 40 when brake release logic 32 triggers. Brake select logic circuit 42 remembers which brake was last disabled and switches switch 36 when a new brake application has been detected by brake disable circuit 24 .
Brake disable logic 24 responds to both the metered pressure signal and the aircraft speed signal at the time of brake application. Thereafter, logic circuit 24 responds only to the metered pressure signal from sensor 30 until the metered brake pressure returns to the no-braking system pressure. This ensures that following a high speed brake application, such as a landing, the brake release command will not be produced, and half the brakes will not be released, as the aircraft decelerates through the brake disable speed threshold. The disable signal would then only be produced at low speed after the brakes were released, then reapplied.
If an emergency stop, i.e., high metered pressure is sensed by brake disable circuit 24 , then brake release logic 32 removes the brake release command so that both brakes 6 and 8 are applied, thus insuring full aircraft braking capability when it is needed. Similarly, if a higher speed stop, such as a landing stop or rejected take off, is sensed by brake disable circuit 24 from the aircraft speed signal, then the brake release logic 32 removes the brake release command so that both brakes 6 and 8 may share the braking energy, preventing overheating of an individual brake or brakes.
While the desired braking intensity has been described in terms of metered braking pressure, other input to the brake disable circuit providing like information would be equally useful. For example, the acceleration and throw of the brake pedal in the cockpit could be monitored or the rate of brake temperature increase. Similarly, input other than aircraft speed such as wheel speed or aircraft ground speed measured independently of the wheel speed could be inputted to the brake disable circuit. Such alternatives will be apparent to those skilled in the art.
The invention has been described specifically in FIG. 1 in terms of a brake pair on one side of an aircraft. However, systems in accordance with this invention for aircraft with other numbers and arrangements of carbon braked wheels could be readily adapted by persons skilled in the art. For example, FIG. 2 shows the wheel configuration for a wide-bodied Boeing 747-400™ series aircraft equipped with a carbon brake on each main gear wheel. The nose wheel which is not braked is not shown.
Referring to FIG. 2 , there are four four-wheel trucks located under the left wing 44 , left body 46 , right body 48 and right wing 50 of an aircraft. Using truck 44 as an example, wheels 52 and 54 on one side, and 56 and 58 on the other side of a four-wheel axle frame 60 each provide input to a brake disable circuit 62 like that described in FIG. 1 . A metered brake pressure signal would also be provided to each like brake disable circuit. Thus, when both the aircraft speed at time of brake application and metered brake pressure are below target values, half of the sixteen brakes would be disabled. For example, brakes on wheels 52 and 54 on the left side of the truck 60 would be alternately disabled during successive brake applications as would the brakes on wheels 56 and 58 .
Since Carbon brake wear is a function of the number of applications, and since the vast majority of brake applications occur during taxiing, the life of carbon brakes is significantly improved by practicing this invention. For example, if half the brakes are applied during each taxi brake application, brake wear life could nearly double. The life of carbon brakes might be proportionately extended even further by disabling even more than half the brakes during each braking cycle. System logic insures maximum braking capability during emergency braking, i.e., high pressure, conditions. Overheating of individual brakes is prevented because system logic alternates between brakes to share the braking energy among all the brakes.
Other system refinements such as redundant metered pressure sensors could be added to improve failure mode performance. Also, means could be provided to smooth brake pedal control responsiveness in the cockpit between partial brake and full brake transitions. That is, the back pressure on the brake pedal could be adjusted so that equal pedal depression results in equal braking responsiveness irrespective of how many brakes are being disabled at a given time. Brake temperature could also be considered in the brake disabling algorithm to prevent disablement if some brakes are too hot from previous brake applications.
While the invention has been described in terms of specific embodiments thereof, other forms may be readily adapted by one skilled in the art. Accordingly, the scope of the invention is to be limited only in accordance with the following claims.
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Methods and systems are provided for improving brake performance, including extending the life of carbon brakes on aircraft. One embodiment of the method comprises measuring the speed of the aircraft and the intensity of braking and comparing these to predetermined maximum values for each. If the values are both lower than the maximum values, one or more of the brakes are selectively disabled. In other embodiments, the methods and systems can include other features, including providing selected back forces on brake pedals.
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BACKGROUND OF THE INVENTION
The present invention relates generally to the art of pyrolytic deposition of metal oxide films, and more particularly to the pyrolytic deposition of metal oxide films from aqueous compositions of coating reactants.
The pyrolytic deposition of metal oxides onto a glass surface is described in U.S. Pat. No. 3,660,061 to Donley et al. Organometallic salts, preferably acetylacetonates, are dissolved in an organic vehicle such as methylene chloride. Other suitable solvents include aliphatic and olefinic halocarbons, halogenated hydrocarbons, alcohols, and nonpolar aromatic compounds such as benzene and toluene. The organic solution is sprayed onto a hot glass surface where it thermally decomposes to form a metal oxide film which alters the reflectance and transmittance of solar energy by the glass.
Current interest in eliminating the health and environmental hazards of using large volumes of organic solvents has encouraged the development of aqueous coating compositions. It is known from U.S. Pat. No. 2,688,565 to Raymond that light reflecting coatings of cobalt oxide may be deposited by contacting a hot glass surface with an aqueous solution of cobalt acetate. However, such films have a grainy, irregular texture and poor acid resistance evidenced by debonding of the film.
U.S. Pat. No. 4,308,319 to Michelotti et al discloses the pyrolytic deposition of a durable, uniform, solar energy reflecting spinel-type film from an aqueous solution of a water soluble cobalt salt and a water soluble tin compound.
U.S. patent application Ser. No. 463,195 filed on even date herewith by V. A. Henery discloses pyrolytic deposition of metal oxide films from aqueous suspensions wherein organometallic coating reactants are physically suspended in aqueous media by means of vigorous and continuous agitation.
SUMMARY OF THE INVENTION
The present invention involves the pyrolytic deposition of light and heat reflective metal oxide films having similar spectral, physical and chemical properties in comparison with films pyrolytically deposited from organic solutions. However, films in accordance with the present invention are pyrolytically deposited from an aqueous suspension wherein organometallic coating reactants typically used in organic solutions are chemically suspended in an aqueous medium by use of a chemical wetting agent in combination with extremely fine powder reactants. The organometallic coating reactants chemically suspended in an aqueous medium may be pyrolytically deposited to form metal oxide films on a hot glass substrate using conventional spray equipment, and under temperature and atmosphere conditions generally encountered in pyrolytic coating operations. As a result, commercially acceptable transparent metal oxide films comparable to those currently deposited from organic solutions can now be produced using the same coating facilities while eliminating the costs and hazards of organic solvents by employing aqueous suspensions.
DESCRIPTION OF THE DRAWING
The figure illustrates hoppers 1 equipped with scales 2 which feed powdered coating reactants into a jet mill 3 which pulverizes the coating reactants to ultrafine powder which is conveyed to a baghouse 4 and delivered through an air lock 5 into a mixing tank 6 equipped with a stirrer 7 which gently stirs the aqueous suspension. The aqueous suspension is delivered by pump 8 through a filter 9 which removes impurities or undispersed coating reactant en route to spray guns (not shown).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While interest in eliminating the health and environmental hazards, as well as the cost, of organic solvents in pyrolytic coating processes has encouraged the use of aqueous coating solutions, many coating reactants, particularly organometallic coating reactants, have such low solubility limits in water that pyrolytic deposition has not been feasible. For example the acetylacetonates disclosed in U.S. Pat. No. 3,660,061 for pyrolytic deposition of metal oxide films on glass produce high quality, high performance coated products. However, their solubilities in water are relatively low; at 30° C. only 0.3% for cobaltic acetylacetonate and only 0.15% for chromic acetylacetonate. At such concentrations, very large volumes of aqueous solutions would be required, resulting in prohibitive cooling and possible breakage of the glass as well as unacceptably slow film formation rates.
In accordance with the present invention, relatively water-insoluble coating reactants, such as acetylacetonates, are chemically suspended in an aqueous medium by utilizing very fine micron-sized particles of coating reactants in combination with a chemical wetting agent. Thereby, concentrations as high or higher than those obtainable in organic solvents may be achieved in an aqueous suspension. The resulting aqueous suspension may be applied by conventional means, typically spraying, to a substrate to be coated, particularly a hot glass surface, preferably a float glass ribbon.
Although acetylacetonates are the preferred coating reactants in accordance with the present invention, various other organometallic coating reactants may also be employed, as well as relatively water-insoluble compounds in general. The principle of chemically suspending a relatively insoluble coating reactant in an aqueous medium has wide applicability in the field of pyrolytic deposition of films.
In preferred embodiments of the present invention, relatively water-insoluble coating reactants are obtained in solid, powder form. The powder is jet milled to a uniform, fine powder having particles typically less than 10 microns, preferably from about 2 to 5 microns, in diameter. In typical coating processes, when a mixture of metal oxides is desired in the film, organometallic coating reactants are first mixed together in the desired proportions, jet milled to obtain the desired particle size, and then added to the aqueous medium which contains a chemical wetting agent in order to form a chemical suspension.
The aqueous medium is preferably distilled or deionized water. However, if a more viscous medium is desired, a mixture of water and glycerol or other water-miscible organic thickener, may be used. The aqueous medium further comprises a wetting agent which acts to disperse, deaerate and suspend the ultrafine coating reactant particles. Various wetting agents, including anionic, nonionic and cationic compositions, are suitable, in amounts which are determined empirically depending on the wetting agent, the coating reactants and their concentrations, and the aqueous medium. The essential feature of the present invention involves the use of a wetting agent in combination with ultrafine particles of coating reactant to form a chemical suspension in an aqueous medium. The wetting agent displaces air entrained in the powder, and promotes dispersion and suspension of the powder particles by wetting their surfaces. Without the chemical wetting agent, the ultrafine particles would float on the surface of the aqueous medium.
In a most preferred embodiment of the present invention, a mixture of metal acetylacetonates is blended, jet milled to a particle size less than 10 microns, and added with stirring to water which contains a wetting agent. An aqueous suspension is formed which is a true chemical suspension as evidenced by the fact that after storage for more than 3 months with no stirring or mixing, very little separation or settling of the coating reactants from the aqueous suspension has occurred. The aqueous suspension is delivered by means of conventional pyrolytic spray equipment to the surface of a hot float glass ribbon. The coating reactants pyrolyze to form a metal oxide film having similar spectral, physical and chemical properties to a film formed by pyrolysis of the same coating reactants in an organic solution. Moreover, films pyrolytically deposited from aqueous suspensions in accordance with the present invention exhibit faster growth rates than the growth rates measured for films pyrolytically deposited from organic solutions, typically about one third faster. This faster growth rate enables the deposition of acceptable films at faster line speeds.
The present invention will be further understood from the description of specific examples which follow.
EXAMPLE I
An aqueous suspension is prepared by blending 117.7 grams of cobaltic acetylacetonate, 30.2 grams of ferric acetylacetonate and 41.0 grams of chromic acetylacetonate per liter of suspension, jet milling the powders to an average particle size less than about 10 microns, and adding the mixture to water containing 0.3 percent by volume of a nonionic wetting agent which comprises propylene oxide polymer and propylene glycol initiator. Such a wetting agent is available as Pluronic L-31 from BASF Wyandotte Corp. The aqueous suspension thus formed is pumped through a filter as shown in FIG. 1, and delivered by means of spray guns to the surface of a glass sheet which is at a temperature of about 1100° F. The organometallic coating reactants pyrolyze to form a mixed metal oxide film comparable in spectral, physical and chemical properties to the films formed from organic solutions of the same reactants as taught in U.S. Pat. No. 3,660,061, the disclosure of wnich is incorporated herein by reference. Such comparable films are formed at a growth rate about 33 percent faster than the rate of film formation experienced with organic coating solutions.
EXAMPLE II
During a coating process as described in Example I, exhausted material is recovered in a reclamation baghouse, similar to the collection baghouse illustrated in FIG. 1. The metal acetylacetonates are recovered by solution in methylene chloride. The dried powder is again jet milled for an average particle size less than about 10 microns. Specific metal acetylacetonates are added as needed to establish the proportions in Example I. The reconstituted powder is chemically suspended in an aqueous medium containing wetting agent and delivered to a hot glass substrate as in the previous Example, resulting in a coating with substantially identical properties, indicating that recovery and reuse of the reactants are commercially feasible.
EXAMPLE III
A dry powder mixture of 117.7 grams per liter of suspension cobaltic acetylacetonate, 30.2 grams per liter ferric acetylacetonate and 41.0 grams per liter chromic acetylacetonate is jet milled to an average particle size of about 10 microns or less, and dispersed in an aqueous medium comprising 60 percent by volume water and 40 percent by volume glycerol, which contains 0.3 percent (of combined volume) Pluronic L-31 wetting agent. The aqueous suspension is sprayed on the surface of a hot glass substrate, and forms a durable film of excellent quality at a film growth rate comparable to that of organic coating solutions.
EXAMPLE IV
A mixture of acetylacetonates is milled and suspended as in the previous examples. The aqueous medium comprises 60 percent by volume water and 40 percent glycerol. The aqueous suspension medium further comprises 0.3 percent (based on total volume of the water and glycerol) of a nonionic alkaryl polyether alcohol available as Triton X-100 from Rohm and Haas. The aqueous suspension is sprayed on a hot glass surface as in the previous examples to form a durable metal oxide film.
The above examples are offered to illustrate the present invention. Various other coating reactants, wetting agents, concentrations, additives, substrates, and temperatures may be used to form a wide variety of coatings from aqueous suspensions. For example, other suitable wetting agents include nonionic polypropylene oxide compositions; 1,1,4,4-tetraalkyl-2-butyne-1,4 diol; and anionic lauryl sulfate compositions at various concentrations. The scope of the present invention is defined by the following claims.
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A method is disclosed for depositing metal containing films using relatively water-insoluble coating reactants by dispersing said coating reactants in ultrafine powder form into an aqueous medium containing a wetting agent to form an aqueous chemical suspension.
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This application claims priority to International Patent Application PCT/SE2005/001834, filed 5 Dec. 2005, Publication No WO 2006/062454 A1, which claimed priority to Great Britain patent application 0426709.2 filed 6 Dec. 2004.
BACKGROUND OF THE INVENTION
This invention relates to a data compression method, and in particular concerns a method for transmitting data in a compressed form in real time. The invention may be used in devices such as vehicle safety systems in which the speed of transmittal of data is important.
Both when transmitting and storing data it is often desirable to compress the data to allow quick transmission thereof, to enable use of cheaper transmission lines having lower transmission capacities, or to ensure that less memory space is required to store the data. Many types of data contain redundant information which may be discarded before transmission or storage. The amount of redundant information present in a quantity of data will depend in part upon the type of the data. By using an appropriate algorithm, it is often possible to discard some or all of the redundant information to reduce the quantity of data before transmittal or storage thereof, and to recover this information when the data is to be used again.
Compression algorithms for use with a quantity of data representing a series of consecutive values of a parameter—for example, a sound signal from a microphone or an output from a volt meter or accelerometer—may need to use values which appear before and as well as after a current value in the series of values. If this is the case, there will be a delay involved in the compression of the data, as the algorithm waits for the required subsequent value to be received. In the case of a quantity of data representing an image, the delay due to compression may be larger still, because values relating to lines adjacent a current line in the image may need to be used.
For certain applications it is, however, important that the delays involved in transmission of data are minimized. An example of such circumstances is the transmission of data from a crash sensor, for instance an accelerometer, to a control unit that controls the deployment of a safety device in a vehicle. If a crash sensor has determined that the vehicle is involved in a crash situation, any delay before, for example, an airbag is inflated should clearly be as short as possible.
It is an object of the present invention to provide a method for transmitting data in a compressed form involving minimal delays.
SUMMARY OF THE INVENTION
Accordingly, one aspect of the present invention provides a method for transmitting the value of a parameter in a compressed form, the method comprising the steps of: accepting successive numbers representing the value of a parameter; manipulating each number, the manipulation comprising placing the number in a form comprising a mantissa and an exponent, and defining a transmission mantissa to be transmitted; transmitting to a receiver, in turn, only the transmission mantissas of the successive numbers; and receiving the transmission mantissas of the successive numbers at the receiver, characterized by the steps of: maintaining a record at the receiver of a receiver variable, the receiver variable initially corresponding to the exponent of an initial number; formulating at the receiver, for each received transmission mantissa, a reconstructed number comprising at least the transmission mantissa and an exponent corresponding to the receiver variable; and altering the receiver variable in a first manner if the transmission mantissa of the current number fulfills a first criterion, or altering the receiver variable in a second manner if the transmission mantissa of the current number fulfills a second criterion.
Advantageously, the manipulation comprises the step of defining the transmission mantissa as being at least a part of the mantissa if the mantissa is below a first predetermined value, or defining the transmission mantissa as being equal to the first predetermined value if the mantissa is equal to or greater than the first predetermined value. The transmission mantissa of the current number fulfills the first criterion (referenced in the prior paragraph) when the transmission mantissa is equal to the first predetermined value. Altering the receiver variable in the first manner comprises increasing the receiver variable incrementally.
Preferably, a record is maintained at the transmitter of a transmitter variable, the transmitter variable initially corresponding to the exponent of an initial number. The step of placing each number in a form comprising a mantissa and an exponent comprises the step of defining the exponent as being equal to the transmitter variable. The transmitter variable is increased incrementally whenever the transmission mantissa is equal to or greater than the first predetermined value.
Conveniently, the first predetermined value comprises the highest value that the transmission mantissa may have.
Advantageously, the manipulation comprises the step of defining the transmission mantissa as being at least a part of the mantissa if the mantissa is greater than a second predetermined value, or defining the transmission mantissa as being equal to the second predetermined value if the mantissa is equal to or less than the second predetermined value. The transmission mantissa of the current number fulfills the second criterion when the transmission mantissa is equal to the second predetermined value. Altering the receiver variable in the second manner comprises decreasing the receiver variable incrementally.
Preferably, a record is maintained at the transmitter of a transmitter variable, the transmitter variable initially corresponding to the exponent of an initial number. The step of placing each number in a form comprising a mantissa and an exponent comprises the step of defining the exponent as being equal to the transmitter variable. The transmitter variable is incrementally decreased whenever the transmission mantissa is equal to or less than the second predetermined value.
Conveniently, the second predetermined value comprises the lowest value that the transmission mantissa may take.
Advantageously, the manipulation comprises the step of defining the transmission mantissa as being at least a part of the mantissa. The transmission mantissa of the current number fulfills the second criterion when the first x significant digits of the transmission mantissa are 0. Altering the receiver variable in the second manner comprises decreasing the receiver variable by x.
Preferably, a record is maintained, at the transmitter, of a transmitter variable, the transmitter variable initially corresponding to the exponent of an initial number. The step of placing each number in a form comprising a mantissa and an exponent comprises the step of defining the exponent as being equal to the transmitter variable. The transmitter variable is decreased by x whenever the first x significant digits of the transmission mantissa are 0.
Conveniently, the step of altering the receiver variable in a first or second manner occurs after the step of formulating a reconstructed number.
Alternatively, the transmission mantissa of the current number fulfills the first criterion if the transmission mantissa of the current number is less than the transmission mantissa of the previous number by more than a first predetermined amount. Altering the receiver variable in the first manner comprises increasing the receiver variable incrementally.
Advantageously, the transmission mantissa of the current number fulfills the second criterion if the transmission mantissa of the current number is greater than the transmission mantissa of the previous number by more than a second predetermined amount. Altering the receiver variable in the second manner comprises decreasing the receiver variable incrementally.
Preferably, the step of altering the receiver variable in a first or second manner occurs before the step of formulating a reconstructed number.
Conveniently, the step of placing each number in a form comprising a mantissa and an exponent comprises the step of defining a mantissa in a digital form in which the most significant digit of the mantissa is 1, the remaining digits comprising a characteristic portion; and the step of defining a transmission mantissa comprises defining a transmission mantissa being equal to the characteristic portion.
Another aspect of the present invention provides a method of receiving values of a parameter in a compressed form, the method comprising the step of: receiving transmission mantissas of successive numbers, the numbers representing the value of a parameter, and being characterized by the steps of: maintaining a record of a receiver variable, the receiver variable initially corresponding to the exponent of an initial number; formulating, for each received transmission mantissa, a reconstructed number comprising at least the transmission mantissa and an exponent corresponding to the receiver variable; and altering the receiver variable in a first manner if the transmission mantissa of the current number fulfills a first criterion, or altering the receiver variable in a second manner if the transmission mantissa of the current number fulfills the second criterion.
A further aspect of the present invention provides a receiver for receiving values of a parameter in a compressed form, the receiver being operable to receive transmission mantissas of successive numbers, the numbers representing the value of a parameter, and being characterized by being operable to: maintain a record of a receiver variable, the receiver variable initially corresponding to the exponent of an initial number; formulate, for each received transmission mantissa, a reconstructed number comprising at least the transmission mantissa and an exponent corresponding to the receiver variable; and alter the receiver variable in a first manner if the transmission mantissa of the current number fulfills a first criterion, or alter the receiver variable in a second manner if the transmission mantissa of the current number fulfills a second criterion.
Another aspect of the present invention provides a method for transmitting the value of a parameter in a compressed form, the method comprising the steps of: accepting successive numbers representing the value of a parameter; manipulating each number, the manipulation comprising placing the number in a form comprising a mantissa and an exponent, and defining a transmission mantissa as being at least a part of the mantissa, if the mantissa is below a first predetermined value, or defining the transmission mantissa as being equal to the first predetermined value if the mantissa is equal to or greater than the first predetermined value; transmitting to a receiver, in turn, the transmission mantissas only of the successive numbers; and receiving the transmission mantissas of the successive numbers at the receiver characterized by the steps of maintaining a record at the receiver of a receiver variable, the receiver variable initially corresponding to the exponent of an initial number; for each received transmission mantissa formulating at the receiver, a reconstructed number comprising at least the transmission mantissa and an exponent corresponding to the receiver variable; and increasing the receiver variable incrementally if the transmission mantissa of the current number is equal to the first predetermined value, or altering the receiver variable in a second manner if the transmission mantissa of the current number fulfills a second criterion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic view of a vehicle safety system in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
In order that the present invention may be more readily understood, embodiments thereof will now be described, with reference to the accompanying FIG. 1 , which shows a schematic view of a vehicle safety system. The following description is merely exemplary in nature and is in no way intended to limit the invention or its application or uses.
With reference to FIG. 1 , a vehicle safety system 1 is shown. The vehicle safety system 1 comprises a control unit 2 which, in the present example, is operable to inflate an airbag (not shown), and hence is located near the steering wheel of the vehicle 3 in which the safety system 1 is installed.
Various sensors are arranged around the vehicle 3 and are configured to detect a crash situation. The sensors include an accelerometer 4 which is located near the center of mass of the vehicle 3 , front impact sensors 5 which are located near a front bumper 6 of the vehicle 3 , and side impact sensors 7 which are arranged on respective opposing sides 8 of the vehicle 3 . Communication lines 9 are provided between the sensors 4 , 5 , 7 and the control unit 2 . In the event one of the sensors 4 , 5 , 7 detects a crash situation, data is transmitted along the communication lines 9 to the control unit 2 , which inflates the airbag accordingly.
In many safety systems, information that is transmitted to trigger the deployment of, for instance, an airbag comprises the value of a measured parameter, rather than a direct indication of a crash situation. For instance, in the case of the accelerometer 4 , information comprising a series of values representing the magnitude of the acceleration experienced by the accelerometer 4 at successive sampling intervals will be transmitted along the communication line 9 connecting the accelerometer 4 to the control unit 2 .
As discussed above, it is desirable to compress this information to allow the information to be transmitted more rapidly or allow the use of cheaper transmission lines. It is, however, important that no delay is incurred in the compression process as, for instance, might occur if the compression algorithm were to wait for subsequent values before transmitting data relating to a current value, since this would negate the advantage gained by compressing the data to allow faster transmission thereof or the use of transmission lines.
The accelerometer 4 measures values of experienced acceleration, which are (in the present example) output in an absolute binary form. This is converted, by a processor (not shown) associated with accelerometer 4 to a binary scientific notation, comprising a mantissa and an exponent. In some cases, a normalized scientific notation (i.e. a normalized floating form) is used, in which the radix point is placed after the first non-zero digit. Examples of values in decimal form (for reference) in a binary absolute form, in a binary floating point form and in a binary non-normalized scientific form are shown below:
Decimal
Binary Absolute
Binary Floating
Scientific Non-
Form
Form
Form
Normalized Form
1
1.000
1.000E00
0.001E11
2
10.00
1.000E01
0.010E11
4
100.0
1.000E10
0.100E11 or 10.00E01
A first embodiment of the present invention will now be described. In an initial calibration step, the exponent of a first measured value of acceleration, or a predetermined exponent, is stored by the processor associated with the accelerometer 4 as a transmitter variable. Also, at least the exponent of the first measured value of acceleration may be transmitted along the communication line 9 to the control unit 2 , which stores this initial exponent as a receiver variable. Alternatively, a further predetermined exponent is stored as the receiver variable.
Preferably, both the transmitter variable and the receiver variable are set to be a predetermined exponent (e.g. both set as 00) each time the system is initialized. After this initialization, or following the above-described initial calibration step, the treatment of subsequent sensed values of acceleration will be described.
When a new sensed value of acceleration is received by the processor, the value is again converted to a scientific form, comprising a mantissa and an exponent which is equal to the current transmitter variable. If the mantissa is equal to or below a first predetermined value, for instance 1.111, this mantissa will be transmitted to the control unit 2 , assuming that the transmission line is selected to be able to transmit only 0.000 to 1.111 as possible mantissas The control unit 2 will then be able to reconstruct the scientific form of the sensed value of acceleration by using the received mantissa as the mantissa of the reconstructed number and using the receiver variable as the exponent of the reconstructed number. This means that without the exponent being transmitted to the control unit 2 , the sensed value of acceleration can be fully reconstructed at the control unit 2 .
If, however, the sensed value of acceleration is transmitted to a scientific form having the transmitter variable as its exponent and a mantissa that is greater than the first predetermined value (in this case, 1.111), then the value of 1.111 will be transmitted to the control unit 2 as the transmission mantissa. In this preferred embodiment of the invention, the first predetermined value is equal to the highest value that the mantissa can take, i.e. 1.111 in the case of a 4-digit mantissa. The processor transmits this highest value, and subsequently increases the stored transmitter variable by 1. Also, when the exponent of the sensed value is equal to the transmitting variable and the mantissa is equal to the first predetermined value, the transmitter variable should be increased by 1 after transmission of the mantissa to the control unit 2 .
On receiving a mantissa which is equal to the first predetermined value, the control unit 2 again reconstructs the sensed value of acceleration, in the same manner as described above. Once this value has been reconstructed, however, the control unit 2 increases the stored receiver variable by 1.
It will be appreciated that (unless the mantissa of the converted sensed value of acceleration happens to be equal to the first predetermined value) this reconstructed value will be inaccurate, since the actual value of the mantissa of the scientific form of the sensed value of acceleration has not been transmitted to the control unit 2 . However, the next-received sensed value of acceleration will have a scientific form with an exponent one unit higher than before, and the mantissa is likely to be below the first predetermined value, allowing this next sensed value of acceleration to be reconstructed correctly by the control unit 2 . Thus, a skilled person will appreciate that as the sensed value of acceleration rises values of acceleration reconstructed at the control unit 2 will contain inaccuracies, but that these inaccuracies will disappear once the sensed value of acceleration stabilizes.
An advantage of the present invention is that a sudden rise in the sensed value of acceleration, corresponding to a mantissa of the converted sensed value of acceleration having more than 2 digits to the left of the radix point, can be tracked reliably. If, for example, the value of the sensed acceleration rises so that the mantissa of the scientific form thereof will have 3 digits to the left of the radix point, 3, the following steps will occur.
When the sharply increased new sensed value is converted, the mantissa thereof is compared with the first predetermined value. This comparison will reveal that the mantissa is higher than the first predetermined value, and therefore the transmitter will transmit, as the transmission mantissa, the first predetermined value (e.g. 1.111). The transmitter will also incrementally increase the stored transmitter variable by 1.
When the next sensed value is converted by the transmitter, assuming that the next value is approximately equal to the previous, sharply-increased value, the transmitter will again determine that the mantissa of the converted value is greater than the first predetermined value, having 2 digits to the left of the radix point, and will again transmit a mantissa equal to the first predetermined value, and incrementally increase the stored transmitter variable by 1.
When a new sensed value is converted, again assuming that this value is approximately equal to the previous two values, the transmitter will determine that the mantissa of this converted value is equal to or less than the first predetermined value, and will therefore simply transmit the mantissa of the converted value as the transmission mantissa, in the normal way.
Upon receiving the two first successive mantissas which are each equal to the first predetermined value, the control unit 2 will have increased the stored receiver variable by 1 on each occasion, and will therefore correctly reconstruct the scientific form of the final new sensed value its entirety. If the final mantissa is equal to the first predetermined value then of course the transmitter and receiver variables will be increased once more as described above.
A skilled person will, however, appreciate that the inaccuracy in the reconstructed value of the acceleration will be relatively large when the actual sensed value of acceleration changes rapidly. It is, however, considered that in many circumstances this temporary loss of accuracy is compensated for by the ability of the invention to track sharp changes in the sensed acceleration in a robust manner.
A skilled person will appreciate how the above-described technique may be applied to a situation in which the sensed value of acceleration decreases. It is, however, envisaged that there are a number of ways in which these changes may be tracked.
Firstly, the system may define a second predetermined variable (which may be transmitted as the transmission mantissa when the actual mantissa of the sensed value of acceleration falls below a certain value). For instance, if the mantissa of the sensed value of acceleration is equal to or less than a second predetermined variable, which may for example be half of the maximum transmittable mantissa, i.e. 0.111 or below in the case of a four-digit mantissa, the mantissa of the converted value will be transmitted, and the stored transmitter variable will be decreased by 1. The control unit 2 will reconstruct the sensed value of acceleration in the manner described above, and will also decrease the stored receiver variable by 1. This may be repeated until the receiver variable reaches its lowest possible value (e.g. 00). After this, the transmitter and receiver variables can no longer decrease and the mantissa will simply decrease if the sensed value of acceleration falls further.
Alternatively, the processor associated with the accelerometer 4 may be programmed so that, if the mantissa begins with x zeros (where x is greater than zero), then the actual mantissa of the sensed value of acceleration is transmitted, and the stored transmitter variable is subsequently decreased by x.
Upon receiving this mantissa, the control unit 2 will reconstruct the sensed value of acceleration in the manner described above, and will subsequently decrease the stored receiver variable by x.
For instance, a sensed value of acceleration may be converted into the number 1.010E04. Assuming that this does not represent a significant departure from the previous few sensed values, then the stored transmitter variable, as well as the stored receiver variable, will be 4. If the converted next sensed value of acceleration is 0.010E04, then the transmitter transmits the mantissa 0.010, and then decreases the stored transmitter variable by 2. Similarly, on receipt of the mantissa, which begins with two zeros, the stored exponent of the receiver is decreased by 2. After this, the mantissas corresponding to the sensed values of acceleration are transmitted as normal. In this way, when the sensed value of acceleration decreases rapidly, the changes can be tracked quickly and accurately.
When the exponent of the scientific form of the sensed value of acceleration is zero, and the stored transmitter variable is also zero, then the exponent will not decrease any further. Once this has occurred, the mantissa may drop as low as 0000, which will typically correspond to no sensed acceleration.
In a further alternative method of handling decreasing sensed values of acceleration, only mantissas equal to or greater than a second predetermined value are transmitted. If the mantissa converted new sensed value is below the second predetermined value, the second predetermined value will be transmitted instead. This means that only values from 1.000 to 1.111 are transmitted. In this case, the first digit (the integer) is always 1, and thus will not need to be transmitted. This means that only the fractional part of the mantissa or the second predetermined value is transmitted. This reduction in the quantity of data that needs to be transmitted allows the use of a cheaper transmission line, having a lesser transmission capacity.
After a value equal to the fractional part of the second predetermined value (e.g. 000) is transmitted, the transmitter variable will be decreased by 1, and after the sensed value of acceleration is being reconstructed at the control unit 2 , the receiver variable will also be decreased by 1. In this embodiment, the decreasing values are handled in a manner analogous to that with which increasing values are dealt.
A second embodiment of the present invention will now be described. In this embodiment, the sensed value of acceleration is converted to a normalized floating point form. Again, at least the exponent of a first measured value of acceleration is transmitted along the communication line 9 to the control unit 2 , which stores this value as the receiver variable. With this embodiment, however, no transmitter variable need be stored.
New values of sensed acceleration are manipulated into the form “a.bcdEef”, with “a” representing the integer part of the mantissa, “bcd” representing the fractional part of the mantissa and “ef” representing the exponent. For a normalized floating point form, a will always be 1 and so does not need to be transmitted. Only the fractional part of the mantissa, therefore, needs to be transmitted to the control unit 2 as the transmission mantissa. In common with the above-described embodiment, the exponent part of the binary floating point forms are discarded prior to transmission, and in this embodiment the integer is also discarded. The manner in which this discarded data can be reconstructed upon receipt of the transmitted part of the mantissas by the control unit 2 will be described below.
Assuming that the measured acceleration is continuous and is not subject to very large fluctuations between consecutive samples (this might be achieved by passing the samples through a low pass filter), then the mantissa will jump from a value close to or equal to its upper limit to a value close to or equal to its lower limit as the exponent increases by one unit. To illustrate this, the following table shows the variations in a decimal value, the absolute binary equivalent, the binary floating point equivalent, and the fractional part (which might also be referred to as the characteristic part) of the mantissa of the binary floating point equivalent, as the decimal value rises gradually from 1 to 2:
Fractional
Fractional
Decimal
Binary Absolute
Binary Floating
Part of
Form
Form
Form
Form
Mantissa
8/8
1.000
1.000
1.000E00
000
9/8
1.125
1.001
1.001E00
001
. . .
15/8
1.875
1.111
1.111E00
111
16/8
2.000
10.00
1.000E01
000
It can be seen that as the decimal number rises from just below 2 to 2, the exponent changes from 00 to 01. At the same time, the transmitted part of the mantissa drops from 111 (the highest value thereof) to 000 (the lowest value thereof). Conversely, it will be appreciated that, if the decimal number dropped from 2 to slightly below 2, the exponent would drop from 01 to 00 and the transmitted part of the mantissa would rise sharply from 000 to 111.
If an initial sensed value acceleration is 1 (in arbitrary decimal units), and exponent of the binary floating point equivalent of this value is transmitted from the accelerometer 4 along the communication line 9 to the control unit 2 , where this information is stored, subsequent changes in the exponent may be determined simply from knowledge of the transmitted part of the mantissa only of subsequent values. In the example given above, it could be determined that, when the transmitted part of the mantissa changes from 111 to 000, the value of the sensed acceleration has risen from just below 2 to 2, and hence the control unit 2 may raise the stored receiver variable by 1 this time before the current value is reconstructed, and effectively reconstruct the binary floating point form of the sensed acceleration by using the formula 1.bcdExy (where “xy” is the stored receiver variable), without the need for the entire binary floating point form to be transmitted.
Conversely, if the control unit 2 receives a series of transmitted parts of mantissas and a transmitted part of 111 is received immediately after a mantissa of 000, it may be determined that the exponent of the binary floating form of the sensed acceleration has decreased by 1, and hence the value of the stored receiver variable is decreased by 1.
In this way, the sensed acceleration may be transmitted accurately from the accelerometer 4 to the control unit 2 in a compressed form, and transmission may occur in real time, without significant delays occurring.
The size of the transmitted part of the mantissa may be selected in dependence upon the type of data that is to be transmitted, and upon the particular application. However, in preferred embodiments of the present invention, the mantissa has at least four digits, and the exponent has at least two digits.
In this embodiment, the format of the numbers is preferably such that the most significant digit of this mantissa is always 1. It will be readily understood from the above table how this is achieved. A desirable consequence of this is that, since the most significant digit is always the same, this digit becomes “redundant information” and need not be transmitted to the receiver.
When used in this specification and claims, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilized for realizing the invention in diverse forms thereof. While the above description constitutes one or more embodiments of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.
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A method for transmitting the value of a parameter in a compressed form, the method comprising the steps of: accepting successive numbers representing the value of a parameter; manipulating each number, the manipulation comprising placing the number in a form comprising a mantissa and an exponent, and defining a transmission mantissa to be transmitted; transmitting to a receiver, in turn, the transmission mantissas only of the successive numbers; and receiving the transmission mantissas of the successive numbers at the receiver, characterised by the steps of maintaining a record, at the receiver, of a receiver variable, the receiver variable initially corresponding to the exponent of an initial number; formulating at the receiver, for each received transmission mantissa, a reconstructed number comprising at least the transmission mantissa and an exponent corresponding to the receiver variable; and altering the receiver variable in a first manner if the transmission mantissa of the current number fulfils a first criterion, or altering the receiver variable in a second manner if the transmission mantissa of the current number fulfils a second criterion.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Pat. App. No. 61/585,038 filed Jan. 10, 2012, the entirety of which is hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was not federally sponsored.
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to the general field of washing machines, and more specifically toward a cartridge used in a system for dispensing substances into a washing machine utilizing one or more cartridges that contain different substances commonly used in the process of washing clothes. The invention contemplates the use of a plurality of preferably different sized or shaped cartridges that are located within removable drawers. Each cartridge contains a particular substance, such as laundry detergent, bleach, or fabric softener, that is released into the washing machine. The washing machine system also includes a means to identify the substance contained within the cartridge as well as when and how much of the substance should be released into the washing machine, hence the cartridge contains a bar code or other readable indicia that communicates with a bar code reader or other reading device located in the washing machine. This bar code or other indicia allows the washing machine to determine whether the cartridge is an original cartridge with contents manufactured, or at least approved, by the company manufacturing the cartridge, or whether it is a re-filled, or even counterfeit cartridge. At the appropriate time, the washing machine dispenses an appropriate amount of substance into the washing machine from the cartridge. This can be accomplished through multiple means. First a pump could pull the substance out of the container and into the washing basin of a washing machine. Alternatively, a valve could be opened and the substance would then pour into the washing basin due to gravitational forces.
Washing machines enable users to wash their clothes in a shorter period of time and with greater ease than otherwise possible when doing it by hand. Whether it is a top loading or side loading washing machine, the clothes are soaked in water and agitated to get the clothes clean. Often, one or more substances such as laundry detergent, fabric softener, or bleach are added to the water to aid the cleaning process. However, how much of each substance and when it is added depends upon various factors, including the type of substance and the wash cycle set on the washing machine. Many users will place laundry detergent directly into the washing machine as it fills with water, then place fabric softener into a special container that releases the fabric softener at the appropriate time, and may also place bleach into yet another container that releases the bleach at its appropriate time.
Handling laundry detergent, fabric softener, bleach, or other common substances used to clean clothes can be unpleasant and even harmful. For example, bleach, which may include chlorine, is a respiratory irritant that attacks mucous membranes and can burn the skin. When adding these substances to the washing machine, either into the washing basin or into a separate receptacle, the amount of each substance must be measured. Pouring from a container into a measuring device, and then into the appropriate location in the washing machine often results in inadvertent spills as well as requiring that the measuring device be cleaned.
Thus there has existed a long-felt need for a system that dispenses an appropriate amount of a particular substance at the appropriate time into a washing machine without requiring a user to potentially come into contact with that substance. Furthermore, there is a need for a system that automatically dispenses a plurality of substances into a washing machine at the appropriate time during a wash cycle.
SUMMARY OF THE INVENTION
The current invention provides just such a solution by having a system for dispensing substances into a washing machine that relies upon a cartridge that has has been prefilled with a substance useful in the process of washing clothes. A plurality of preferably different sized or shaped cartridges are located within removable drawers in the washing machine. Alternatively, the cartridges can be stored in a stand-alone unit that can be purchased and retrofitted to an existing washing machine. Each cartridge contains a particular substance, such as laundry detergent, bleach, or fabric softener, that is released into the washing machine. The washing machine also includes a means to identify the substance contained within the cartridge as well as when and how much of the substance should be released into the washing machine, and the cartridge includes means of allowing the washing machine to identify the substance and the integrity of the cartridge. At the appropriate time, the washing machine dispenses an appropriate amount of substance into the washing machine. A pump pulls the substance out of the cartridge and into the washing basin of a washing machine. Alternatively, a valve is opened and the substance pours into the washing basin due to gravitational forces.
It is a principal object of the invention to provide a cartridge that enables users to safely, cleanly, and efficiently add substances to a washing machine.
It is another object of the invention to provide a cartridge that can be used for dispensing of one or more substances into a washing machine at the appropriate time.
It is a further object of this invention to provide a cartridge which provides a means by which a manufacturer of substances can try to ensure that a cartridge containing this substance cannot be refilled with a competitor's substance and resold.
It is an additional object of the invention to provide a cartridge where the delivery tube is directed not into the washing machine, but rather to a sprayer, where the sprayer can apply a substance, such as stain remover, to selected parts of selected items of clothing before the actual washing in the washing machine is begun.
It is yet another object of the invention to provide a dispensing system that is self-contained so as to eliminate pouring a substance form a separate container into a washing machine.
In a particular embodiment, the current invention is a cartridge that is used in a washing machine system for dispensing a substance into the washing machine comprising a plurality of cartridges, a plurality of level indicators, a plurality of barcode readers, a plurality of dispensing tubes, and a cover, where each cartridge comprises handle, a barcode, a vent, and a delivery tube adapter, where each of the plurality of dispensing tubes mates with a delivery tube of a cartridge, where a substance contained within each cartridge may flow through the delivery tube, where fluid that flows through the delivery tube is inserted into a washing machine, where each level indicator mates with the vent of a cartridge and determines the amount of substance contained within the cartridge, where each barcode reader reads data from a barcode of a cartridge and destroys the barcode of the cartridge, whereby the system for dispensing a substance dispenses a substance from each cartridge at a time and volume determined by the data read from the barcode of each cartridge.
In another embodiment, the current invention is a method of dispensing a substance into a washing machine comprising the steps of: acquiring a cartridge, having a washing machine accepting a cartridge, where the cartridge comprises a vent and a barcode; scanning the barcode of the cartridge; destroying the barcode of the cartridge such that it cannot be read again; inserting a level indicator through the vent and into the cartridge; and dispensing a substance contained within the cartridge into a washing machine; whereby data collected from scanning the barcode is used to determine the volume and timing of dispensing the substance contained within the cartridge into the washing machine.
In an additional embodiment, the current invention is a cartridge that can be used in a washing machine system for dispensing a substance comprising: a barcode reader, a level indicator, and a cartridge, where the cartridge comprises a vent and a barcode, where the barcode reader reads the barcode of the cartridge, where the barcode reader destroys the barcode of the cartridge after the barcode reader has read the barcode, where the level indicator is inserted through the vent and determines the level of a substance remaining within the cartridge.
In a further embodiment, the current invention is a cartridge system for dispensing a substance into a washing machine comprising: at least one cartridge, where the at least one cartridge comprises: six sides that define an inner space, a handle, a barcode, a vent, a delivery tube adapter, and a delivery tube, where the delivery tube adapter mates with the delivery tube, where a substance is contained within the inner space of the cartridge, where the substance may flow through the delivery tube, where the substance that flows through the delivery tube is inserted into a washing machine, where each barcode can contain three or more pieces data, where the three or more pieces of data relate to an identity of the substance, a delivery time which is the time during a washing machine cycle that the substance is to be delivered, and a delivery amount which is the amount of substance to be delivered.
In yet another embodiment, the current invention is a cartridge system for dispensing a substance into a washing machine comprising: at least one cartridge, where the at least one cartridge comprises: six sides that define an inner space, a handle, a barcode, a vent, a delivery tube adapter, and a delivery tube, where the delivery tube adapter mates with the delivery tube, where a substance is contained within the inner space of the cartridge, where the substance may flow through the delivery tube, where the substance that flows through the delivery tube is inserted into a washing machine, where each barcode can contain three or more pieces data, where the three or more pieces of data relate to an identity of the substance, a delivery time which is the time during a washing machine cycle that the substance is to be delivered, and a delivery amount which is the amount of substance to be delivered, further comprising a level indicator, where the level indicator mates with the vent of a cartridge, where the level indicator measures the amount of substance in the inner space, and displays one or more results from that measurement.
In an additional embodiment, the current invention is a cartridge system for dispensing a substance into a washing machine comprising: at least one cartridge, where the at least one cartridge comprises: six sides that define an inner space, a handle, a barcode, a vent, a delivery tube adapter, and a delivery tube, where the delivery tube adapter mates with the delivery tube, where a substance is contained within the inner space of the cartridge, where the substance may flow through the delivery tube, where the substance that flows through the delivery tube is inserted into a washing machine, where each barcode can contain three or more pieces data, where the three or more pieces of data relate to an identity of the substance, a delivery time which is the time during a washing machine cycle that the substance is to be delivered, and a delivery amount which is the amount of substance to be delivered, where the number of cartridges is at least two in number, where one of the cartridges comprises a sprayer, where the sprayer comprises a tube that extends from the delivery tube adapter to a spraying device, where the spraying device comprises a trigger that can be pulled to dispense a substance in the cartridge, a handle portion, where the handle portion is shaped like the grip on a handgun, and a dispensing nozzle, where a user can pull the trigger and dispense the substance onto clothes prior to the clothes being inserted into the washing machine.
In a further embodiment, the current invention is a method of dispensing a substance into a washing machine through a cartridge system, comprising the steps of: accepting a cartridge, where the cartridge comprises: six sides that define an inner space, a handle, a barcode, a vent, a delivery tube adapter, and a delivery tube, where the delivery tube adapter mates with the delivery tube, where a substance is contained within the inner space of the cartridge, where the substance may flow through the delivery tube, where the substance that flows through the delivery tube is inserted into a washing machine, where each barcode can contain three or more pieces data, where the three or more pieces of data relate to an identity of the substance, a delivery time which is the time during a washing machine cycle that the substance is to be delivered, and a delivery amount which is the amount of substance to be delivered; scanning the barcode of the cartridge; destroying the barcode of the cartridge such that it cannot be read again; inserting a level indicator through the vent and into the cartridge; and dispensing a substance contained within the cartridge into a washing machine; whereby data collected from scanning the barcode is used to determine the volume and timing of dispensing the substance contained within the cartridge into the washing machine.
In another particular embodiment, the current invention is a cartridge system for dispensing a substance comprising: a barcode reader, a level indicator, a cartridge, a second cartridge, a third cartridge, and a dispensing tube, where the cartridge comprises: six sides that define an inner space, a handle, a barcode, a vent, a delivery tube adapter, and a delivery tube, where the delivery tube adapter mates with the delivery tube, where a substance is contained within the inner space of the cartridge, where the substance may flow through the delivery tube, where the substance that flows through the delivery tube is inserted into a washing machine, where each barcode can contain three or more pieces data, where the three or more pieces of data relate to an identity of the substance, a delivery time which is the time during a washing machine cycle that the substance is to be delivered, and a delivery amount which is the amount of substance to be delivered; where the barcode reader reads the barcode of the cartridge, where the barcode reader destroys the barcode of the cartridge after the barcode reader has read the barcode, where the level indicator is inserted through the vent and determines the level of a substance remaining within the cartridge, wherein the cartridge further comprises a dispensing adapter, where the dispensing adapter of the cartridge mates with the dispensing tube, whereby a substance contained within the cartridge may flow through the dispensing adapter and through the dispensing tube, where the second cartridge and the third cartridge each comprise a barcode and a vent, where the second cartridge is smaller than the cartridge, where the third cartridge is smaller than the second cartridge, wherein the cartridge, second cartridge, and third cartridge each contain a substance, where the substance of the cartridge is laundry detergent, where the substance of the second cartridge is fabric softener, and where the substance of the third cartridge is bleach.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. The features listed herein and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.
BRIEF DESCRIPTION OF THE FIGURES
The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of this invention.
FIG. 1 is perspective view of a washing machine with a dispensing system illustrating the location of the cartridges, and some of the accessory parts of a washing machine that utilizes one of more of these cartridges to provide an efficient, clean and safe means by which a person can wash clothes.
FIG. 2 is a partial view of the dispensing system of the washing machine and the integration of the cartridges into a drawer of a washing machine showing the attachment of the level indicators and delivery tubes in the cartridges.
FIG. 3 is a perspective view of three cartridges according to selected embodiments of the current disclosure, showing how three cartridges, each of which contain a different substance, would be aligned in the drawers of a washing machine.
FIG. 4 is a perspective view of a washing machine with a dispensing system and integrated stain remover sprayer according to selected embodiments of the current disclosure.
FIG. 5 is a perspective view of a cartridge according to selected embodiments of the current disclosure, illustrating its key features.
DETAILED DESCRIPTION OF THE INVENTION
Many aspects of the invention can be better understood with the references made to the drawings below. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed upon clearly illustrating the components of the present invention. Moreover, like reference numerals designate corresponding parts through the several views in the drawings.
FIG. 1 is perspective view of a washing machine with a dispensing system illustrating the location of the cartridges, and some of the accessory parts of a washing machine that utilizes one of more of these cartridges to provide an efficient, clean and safe means by which a person can wash clothes. A cartridge 20 , as described in the claims of this application, is incorporated into a dispensing system 10 which resides on the top of a washing machine 90 . In this particular illustration, cartridge 20 is a cartridge filled with detergent. The dispensing system 10 has a cover 11 that is connected to the back of the dispensing system 10 by a hinge. The dispensing system 10 accepts cartridges, such as a detergent cartridge 20 , fabric softener cartridge 21 , and a bleach cartridge 22 . A level indicator 31 is used to determine the amount of fluid left within each cartridge. Barcode scanners 33 scan the barcode of each cartridge and then puncture (thereby destroying) each barcode after it is scanned. Described in more detail below, the barcode on the cartridge enables the dispensing system to determine what substance is in the cartridge as well as how much of and when to dispense the substance contained therein.
FIG. 2 is a partial view of the dispensing system and its integration into a drawer of a washing machine according to selected embodiments of the current disclosure, which illustrate the role the cartridge plays in providing the proper amounts of a substance to the washing machine, and how the cartridge interacts with the overall washing machine system. After a cartridge is inserted into the dispensing system, barcode readers 33 scan the barcode ( 25 in FIG. 4 ) of each cartridge. After scanning the barcode, the barcode readers 33 move downward toward the cartridge and pierce each barcode thereby destroying it. By destroying the barcode, the dispensing system prevents repeated use (such as refilling) of the cartridges since the barcode reader 33 will not read a destroyed barcode. The prevention of reuse of the cartridge by a competitor of the manufacturer of the cartridge will optimize profits for the manufacturer by eliminating the opportunity for competitors with lower quality and lower priced substances can refill a cartridge, then resell the cartridge and diminish the reputation of the manufacturer due to having its label on an inferior substance.
Level indicators 31 are also lowered though a vent in each cartridge. In a particular embodiment, each cartridge has a cap that covers the vent, which is removed before it is inserted into the dispensing system. At the appropriate time, fluid from each cartridge is dispensed through delivery tubes 35 to dispensing tubes 37 , which deposit the fluid in an appropriate area of a cleaning substance drawer 91 of a washing machine. The cleaning substance drawer 91 may include a detergent area 91 , a fabric softener area 93 , and a bleach area 94 . The dispensing tubes 37 deposit the appropriate fluid into the appropriate area.
FIG. 3 is a perspective view of three cartridges according to selected embodiments of the current disclosure, showing how three cartridges, each of which contain a different substance, would be aligned in the drawers of a washing machine. Three cartridges are shown in this embodiment: a detergent cartridge 20 , fabric softener cartridge 21 , and a bleach cartridge 22 . The detergent cartridge 20 contains laundry detergent and is the largest of the three cartridges shown. The fabric softener cartridge 21 contains fabric softener and is the second largest cartridge shown. The bleach cartridge 22 is the smallest cartridge shown and contains bleach. Each cartridge includes a vent 27 that is covered with a cap (not shown) when stored or otherwise not in use and not inserted within the dispensing system. A barcode 25 is also placed on each cartridge, which is used to identify the particular substance contained within the cartridge and the particular use instructions associated therewith.
FIG. 4 is a perspective view of a cartridge with an integrated stain remover sprayer according to selected embodiments of the current disclosure. The washing machine dispensing system 10 , in addition to a detergent cartridge, fabric softener cartridge, and bleach cartridge, may include a stain remover cartridge 23 . The stain remover cartridge 23 is designed to allow a user to spray stain remover on particularly dirty portions of clothes. A tube extends therefrom and through an opening in the dispensing system and is connected to a sprayer 39 . The sprayer 39 includes a trigger, which can be pulled to dispense a stain remover substance contained within the stain remover cartridge 23 . Thus, a user may quickly and efficiently treat a stained item of clothing by using the sprayer 39 integrated with the dispensing system 10 .
FIG. 5 is a perspective view of a cartridge according to selected embodiments of the current disclosure, illustrating its key features. The cartridge 20 , in this case in the shape of a detergent cartridge, includes a handle 26 that is used to grasp the detergent cartridge. A vent 27 is an opening that is used to allow air to enter the detergent cartridge 20 as the substance contained therein is withdrawn. A level indicator (not shown in this figure) may also extend through the vent opening 27 to measure the amount of substance remaining in the detergent cartridge 20 . A barcode 25 identifies that particular substance within the detergent cartridge 20 . The substance within the detergent cartridge 20 is withdrawn through a delivery tube 35 . The delivery tube mates with the detergent cartridge 20 via a delivery tube adapter 36 . As the detergent cartridge 20 is inserted into the dispensing system, the delivery tube 35 mates the delivery tube adapter 36 , which is integrated into the detergent cartridge.
The level indicators are inserted through the vent and are used to determine the amount of substance remaining in the particular cartridge. A float moves up and down depending on the level of the substance (fluid) in the cartridge. In other words, as the substance is removed from the cartridge, the float travels downward. Sensors determine the location of the float, and through this the relative amount of substance left in the cartridge.
In a particular embodiment, the dispensing system includes fluid pumps. The fluid pumps are in fluid connection with the cartridges via delivery tubes. Each fluid pump 50 is in electrical connection to a circuit board, such as a motherboard of the dispensing system or washing machine. Solenoid valves may also be utilized to block and unblock the flow of the fluid from the cartridge and to the washing machine cleaning substance drawer. In this manner, the fluid pump and/or solenoid valves are turned on and off as directed by the internal circuitry of the system and/or washing machine.
In another embodiment, the dispensing system lacks fluid pumps, and the substance flows from the cartridge through gravity. It is also contemplated that the drawer section of the washing machine could be tilted, or adjustably tilted, such that the gravitational flow is enhanced.
In another embodiment, the washing machine has drawer capacity to accept four different cartridges, including a stain removing cartridge with an integrated stain remover sprayer. The stain remover cartridge has a sprayer at the end of a tube which is connected to the stain remover cartridge. The sprayer includes a trigger, which can be pulled to dispense a stain remover substance contained within the stain remover cartridge. Thus, a user may quickly and efficiently treat a stained item of clothing by using the sprayer integrated with the dispensing system. It is also contemplated that more than four cartridges could be inserted into one or more drawers in the washing machine.
In another embodiment, the barcode includes data such as the type of substance within the cartridge, volume of the cartridge, manufacturing date, serial number, or codes or encrypted data that verifies the source and authenticity of the laundry detergent cartridge. By checking the data on the barcode of the cartridge, the system ensures that only compatible cartridges manufactured for the system will dispense the substance contained therein. Furthermore, the appropriate volume and timing of the substance to be dispensed is automatically read in by the system and implemented accordingly, thereby reducing user error.
In an alternative embodiment, the barcode includes only encrypted identifying data that is used to query a remote network connected server. By way of example, the barcode reader reads in the data from the barcode. It then uses this data to make a request to a remote server over the internet. The request is made as an http request made over a Wi-Fi-network that is connected to the internet. The data from the barcode, either encrypted or decrypted, is transmitted to the remote server, which then responds with various data related to the cartridge. The response data may include confirmation as to whether or not the cartridge is authentic, whether or not the cartridge has been used previously, the substance located within the cartridge, the amount of substance that should be dispensed per load of laundry, at what point in the cycle the substance should be dispensed, and how much substance is located within the cartridge.
The laundry detergent cartridge includes a vent, handle, and a barcode. The length of the laundry detergent cartridge of a particular embodiment is 14.5 inches, where the handle is 2.5 inches and the remaining portion is 12 inches, and the width of the laundry detergent cartridge is 5.875 inches.
In an alternative embodiment, the laundry detergent cartridge has a generally trapezoidal shape, where the width of the top part is 5.875 inches and the width of the bottom part is 5.0625 inches. The height of the laundry detergent cartridge is 5.5 inches. The trapezoidal shape helps ensure that the laundry detergent cartridge has the proper orientation when it is placed into the dispensing system. Notches in the laundry detergent cartridge may be used to align the laundry detergent cartridge in the appropriate position and location in the dispensing system.
A vent cap allows for air to vent into a cartridge as the substance contained within is removed from the cartridge. The vent cap may be a screw-type cap, wherein the vent cap is placed over a vent and screwed into position. When screwed shut, the vent cap closes the vent. When vent cap is unscrewed, the vent is opened and air is allowed to pass therethrough. Without venting the cartridge, fluid would not easily flow out of the cartridge and through the delivery tube.
The fabric softener cartridge is smaller than the laundry detergent cartridge. Often, more laundry detergent is used than fabric softener per load of laundry. Therefore, the fabric softener cartridge needs to hold less fabric softener than the laundry detergent cartridge needs to hold laundry detergent. In this particular embodiment, the main part of the fabric softener cartridge is 7.125 inches long and 3.5 inches wide. The fabric softener cartridge also includes a handle for grasping and maneuvering the fabric softener cartridge and a vent cap for allowing air to vent into the fabric softener cartridge as fabric softener is removed from the fabric softener cartridge.
In an alternative embodiment, the fabric softener cartridge has a generally trapezoidal shape, where the width of the top part is 3.5 inches. The height of the fabric softener cartridge is 5.25 inches. The trapezoidal shape helps ensure that the fabric softener cartridge has the proper orientation when it is placed into the dispensing system. Notches in the fabric softener cartridge align the fabric softener cartridge in the appropriate position and location in the dispensing system.
In a particular embodiment, the laundry detergent cartridge holds 170 oz. of laundry detergent and the bleach cartridge holds 5 oz. of bleach.
In practice, a user who has purchased one or more cartridges, opens the lid to the dispensing system, removes the vent cap that covers the vent of a cartridge, and then inserts the cartridge into the dispensing system. The user then closes the lid and the dispensing system reads in the barcode located on the cartridge, verifies its authenticity, and then punctures the barcode making it unreadable in the future. If necessary and enabled, the dispensing system queries a remote server for additional information on the cartridge, such as type of substance, size of the container, and dispensing instructions. At the same time or subsequent to reading the barcode, level indicators are inserted through the vent to read in the level of substance remaining within the cartridge.
Should the user find an unusually large amount of stain on a particular item of clothing, the user can use the sprayer portion of the stain remover cartridge to spray stain remover on the dirty portions prior to starting the normal wash cycle.
The user will then place dirty laundry into the washing machine, and start a washing cycle. The dispensing system dispenses an appropriate amount of the substance contained within the cartridge into the washing machine at the appropriate time. For example, a first substance may be deposited into the cleaning substance drawer of the washing machine when the cleaning cycle begins, while a second substance is deposited fifteen minutes after the cycle beings, and then a third substance is deposited 5 minutes before the cleaning cycle ends.
Multiple loads of laundry may be run for each cartridge. When the level indicators determine that there is little substance left within a particular cartridge, such as substance for five or fewer loads, a user is notified. Notifications include without limitation a blinking light, illuminated light, a beep, a buzz, a text message, an email, or red/yellow/green lights and/or bars.
After a cartridge is empty, the user opens the lid of the dispensing system. As the lid is opened, the level indicators are removed from each cartridge and the user may grasp the handle of the empty cartridge and remove it from the dispensing system. If each cartridge is designed to deliver substance for the same number of loads of laundry, and not necessarily the same amount of substance, then all of the cartridges should need to be replaced at roughly the same time.
The system described herein has been shown with three different sized cartridges. One skilled in the art will appreciate that fewer or more than three cartridges of the same or different substances may be implemented. For example, a four-cartridge system may be used where four different substances are desired to automatically dispense into the washing machine. Furthermore, multiple cartridges of the same type and/or size and shape (such as multiple laundry detergent cartridges) may be implemented into the system. Additionally, gravity or pressure pumps may be used to move the fluid substance contained within the cartridge.
It should be understood that while the preferred embodiments of the invention are described in some detail herein, the present disclosure is made by way of example only and that variations and changes thereto are possible without departing from the subject matter coming within the scope of the following claims, and a reasonable equivalency thereof, which claims I regard as my invention.
All of the material in this patent document is subject to copyright protection under the copyright laws of the United States and other countries. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in official governmental records but, otherwise, all other copyright rights whatsoever are reserved.
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A cartridge system for dispensing substances into a washing machine is disclosed. One or more preferably different sized or shaped cartridges are located within removable drawers contained in a washing machine. Each cartridge contains a particular substance, such as laundry detergent, bleach, or fabric softener, that is released into the washing machine. The cartridge system also includes a means to identify the substance contained within the cartridge as well as when and how much of the substance should be released into the washing machine. At the appropriate time, the system dispenses an appropriate amount of substance into the washing machine. A pump pulls the substance out of the container and into the washing basin of a washing machine. Alternatively, a valve is opened and the substance pours into the washing basin due to gravitational forces.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method editing a PLC program in a computer with a pointing device, especially to a method editing a PLC program in a computer with a pointing device, wherein the dragged source in a drag-and-drop operation is identified and the dragged source is selectively converted to program portion compatible to IEC61131.
[0003] 2. Description of Prior Art
[0004] The software developed for programmer logic controller (PLC) control program is mainly focused on Ladder Diagram (LD). LD language has simple syntax and is extensively used for PLC control program. However, LD language is lack of high-level language properties such as variable data structure, arithmetic calculation, object orientation design, and program control. Moreover, the syntax of LD language also depends on PLC hardware platform. Therefore, International Electrotechnical Commission (IEC) has defined IEC 61131-3 standard language to incorporate high-level language properties into the program developing tool of PLC control program.
[0005] IEC 61131-3 defines the following five standard languages.
[0006] 1. LD
[0007] The programming of LD language requires the information of mechanic operation sequence and control loop should be drawn firstly. Afterward, the contact a and the contact b in relay control, the serial and parallel connection and coil are symbolized.
[0008] 2. Functional Block Diagram, FBD
[0009] FBD is composed of predetermined functional block with suitable connection. Therefore, FBD is especially suitable for data flow in control components.
[0010] 3. Instructional List (IL) or Statement List (SL)
[0011] IL is a low level language composed of Boolean algebra and basic logic operation. IL mainly comprises Mnemonics such as AND, OR and NOT.
[0012] 4. Structure Text (ST)
[0013] ST is for PLC with high level language ability such as arithmetic operation, subroutine, loop and condition judgment. Therefore, the PLC with high level language ability can be linked with PC by communication network.
[0014] 5. Sequential Function Chart (SFC)
[0015] SFC decomposes mechanic operation into sequential function flow and then links the sequential functions to realize integral mechanic operation.
[0016] IEC 61131-3 program can be input by program entry device for PLC, or by a computer software in a computer linked to the PLC. The former is suitable for inputting command code; while the latter can input all kinds of PLC languages. When using conventional computer compilation languages such as CoDesys or InfoTeam, program drafters need to memorize the syntax of program. When the program includes function call, the program drafters also need to know the arguments in the called function. It is very inconvenient to user.
[0017] IEC 61131-3 has specific rule for ST and IL language. It is desirable to provide a drag and drop function to edit the PLC program, whereby user need not to memorize the syntax of the called function.
SUMMARY OF THE INVENTION
[0018] It is the object of the present invention to provide a method editing a PLC program in a computer with a pointing device, whereby an IEC61131-syntax program portion corresponding to a dragged source can be automatically pasted to an edit area by a drag-and-drop operation.
[0019] Accordingly, the present invention provides a method editing a PLC program in a computer with a pointing device such as a mouse. When a drag-and-drop operation is detected, a dragged source is identified. When the dragged source is from libraries, the dragged source is optionally converted into an IEC61131-syntax program portion according to the type of the libraries, namely, function or function block. When the dragged source is a POU (Programming Organization Unit), the dragged source is optionally converted into an IEC61131-syntax program portion according to the source POU type, the currently-edited POU type and criterion of forbidding recursion call. When the drag and drop operation is not feasible, the shape of mouse cursor is changed to remind user. The method of the present invention can advantageously convert items in libraries and POU into IEC61131-syntax program portion to facilitate the PLC programming task.
BRIEF DESCRIPTION OF DRAWING
[0020] The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself however may be best understood by reference to the following detailed description of the invention, which describes certain exemplary embodiments of the invention, taken in conjunction with the accompanying drawings in which:
[0021] FIG. 1 is a schematic view for demonstrating the PLC program editing method of the present invention.
[0022] FIG. 2 shows the flowchart of the PLC program editing method according to the first preferred embodiment of the present invention.
[0023] FIG. 3 and FIG. 3A show the flowchart of the PLC program editing method according to the second preferred embodiment of the present invention.
[0024] FIG. 4 shows an exemplary operation according to the method of the present invention.
[0025] FIG. 5A and FIG. 5B show the results of exemplary operation in FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
[0026] FIG. 1 is a schematic view for demonstrating the PLC program editing method of the present invention, which is implemented in a computer with window operation system. There is a function menu shown at upper portion of the window, a program file manager at lower-right portion and an editor area at lower-right portion. However, the layout is only for demonstration and does not pose limitation to the present invention.
[0027] The program file manager has a project tree with two file folders, namely, Library folder and Programming Organization Unit (POU) folder. The files in the Library folder have two types; function (FC) and function block (FB). The POU in project has three types: 1. Program (PG) 2. Function (FC) and 3. Function block (FB). The function in library and POU can be called by user. However, function has been packed and cannot be further edited. A currently-edited program is drafted in the editor area with text input by user.
[0028] As shown in this figure, the POU type in the currently-edited program (shown in the editor area) in this window is program and the title of the POU is ST. IEC61131 has following calling rules:
[0029] 1. Program (PG) can call Function (FC) and Function block (FB).
[0030] 2. Function block (FB) can call Function (FC) and Function block (FB), but cannot call Program (PG).
[0031] 3. Function (FC) can call Function (FC), but cannot call and Function block (FB).
[0032] 4. No recursive call is allowed and POU cannot call itself.
[0033] Therefore, the priority in above calling is Program (PG) Function block (FB) Function (FC) and No recursive call is allowed.
[0034] FIG. 2 shows the flowchart of the PLC program editing method according to the first preferred embodiment of the present invention. The PLC program editing method is operated when an IEC61131 text editor works (step 10 ). When a cursor tool such as a mouse detects a drag and drop operation (step 12 ), the method of the present invention judges whether a dragged content can be dropped to the text editor (step 14 ). If false, the process is back to step 10 . If true, the dragged content is judged to be FB or FC (step 16 ). If the dragged content is FC format, then the dragged content is converted to an FC program portion compatible with IEC61131 syntax (step 16 A), and the program portion compatible with IEC61131 syntax is then pasted to the IEC61131 text editor (step 18 ). If the dragged content is FB format, then the dragged content is converted to an FB program portion compatible with IEC61131 syntax (step 16 B), and the program portion compatible with IEC61131 syntax is then pasted to the IEC61131 text editor (step 18 ). Therefore, by the PLC program editing method of the present invention, PLC programmer can directly drag an FC program or an FB program in the library to a text editor. The program text of IEC61131 format corresponding to the FC program or an FB program is pasted to the text editor for facilitating the programmer to edit program.
[0035] FIG. 3 and FIG. 3A show the flowchart of the PLC program editing method according to the second preferred embodiment of the present invention. The second preferred embodiment demonstrates whether the drop operation is feasible based on the dragged content.
[0036] When a pointing tool such as a mouse detects a drag and drop operation in the IEC61131 text-editor area, which allows user input text to edit an currently-edited PLC program (step 20 ), the method of the present invention judges the source for the dragged content (step 22 ), the follow-up process is performed when the dragged content is from library (step 30 ), when the dragged content is from POU in project (step 50 ), and when the dragged content is from other source (step 70 ).
[0037] When the dragged content is from library (step 30 ), the function type of the dragged content is judged (step 300 ). When the function type of the dragged content is FC, then the dragged content is converted to an FC program portion compatible with IEC61131 syntax (step 302 ), the mouse cursor shape is changed to an icon indicating that “drop” action is allowable (step 314 ), the position corresponding to the cursor is found (step 318 ), and then the FC program portion compatible with IEC61131 syntax is pasted to the IEC61131 text-editor area (step 320 ).
[0038] When the function type of the dragged content is FB, then the POU type of the currently-edited program is judged (step 310 ). When the POU type in currently-edited program is FC, then mouse cursor shape is changed to an icon indicating that “drop” action is not allowable (step 312 ) because FC cannot call FB. When the POU type in currently-edited program is FB or PG, then mouse cursor shape is changed to an icon indicating that “drop” action is allowable (step 314 ), the dragged content is converted to an FB program portion compatible with IEC61131 syntax (step 316 ), the position corresponding to the cursor is found (step 318 ), and then the FB program portion compatible with IEC61131 syntax is pasted to the IEC61131 text-edit area (step 320 ).
[0039] When the dragged content is from a POU in project (step 50 ), the POU type for the dragged content is judged (step 52 ), wherein the POU type for the dragged content is classified into FC (step 54 ), FB (step 56 ) and PG (step 58 ).
[0040] When the POU type for the dragged content is FC, the dragged content is judged whether it has the same name as the POU in the currently-edited program (hereinafter, briefed as currently-edited POU) (step 54 ). If the dragged content has the same name as the POU in the currently-edited program, then the mouse cursor shape is changed to an icon indicating that “drop” action is not allowable (step 540 ) because recursive call is not allowed. If the dragged content has not the same name as the currently-edited POU, then steps 542 to 548 are perform to indicate that “drop” action is allowable, and to convert the dragged POU to program portion compatible to IEC61131 syntax and manifesting IEC calling an FC, and to find the cursor position and to paste the program portion compatible with IEC61131 to the IEC61131 text-editor area.
[0041] When the POU type for the dragged content is FB, the POU type of the currently-edited POU is judged (step 54 ), and step 560 (the POU type of the currently-edited POU is FC), step 562 (the POU type of the currently-edited POU is FB), and step 566 (the POU type of the currently-edited POU is PG) is performed, respectively.
[0042] When the POU type of the currently-edited POU is FC, then the mouse cursor shape is changed to an icon indicating that “drop” action is not allowable (step 560 ) because FC cannot call FB. When the POU type of the currently-edited POU is FB, then the dragged content is judged whether it has the same name as the currently-edited POU (step 562 ). If the dragged content has the same name as the currently-edited POU, then the mouse cursor shape is changed to an icon indicating that “drop” action is not allowable (step 564 ) because recursive call is not allowed. If the dragged content has not the same name as the currently-edited POU, then steps 566 to 572 are perform to indicate that “drop” action is allowable, and to convert the dragged POU to program portion compatible to IEC61131 syntax and manifesting IEC calling an FB, and to find the cursor position and to paste the program portion compatible with IEC61131 to the IEC61131 text-editor area.
[0043] When the POU type of the currently-edited POU is PG, then steps 566 to 572 are perform to indicate that “drop” action is allowable and to convert the source POU to program portion compatible with IEC61131 syntax for pasting to the IEC61131 text-edit area.
[0044] In step 52 , when the POU type of the dragged content is PG, then the mouse cursor shape is changed to an icon indicating that “drop” action is not allowable (step 58 ) because PG cannot be called.
[0045] In step 24 , when the POU type of the dragged content is other, then the mouse cursor shape is changed to an icon indicating that “drop” action is not allowable to warn programmer with error operation.
[0046] With reference to FIGS. 4 , 5 A, and 5 B, an exemplary operation according to above method is demonstrated, wherein a POU of PG type receives a drag-and-drop operation with FB content in library. The flow of operation is shown by dashed line in FIG. 4 .
[0047] When the text editor editing a POU of PG type senses a drag-and-drop operation, the text editor knows that the currently-edited POU is PG and the dragged source is FB. Therefore, the process is step 20 →step 22 →step 24 →step 30 →step 310 →step 314 →step 316 →step 318 →step 320 , as shown in FIG. 4 . According to the process of the present invention, the dragged source is FB and the currently-edited POU is PG. Therefore, the cursor will change to the shape indicating that “drop” action is allowable. The source POU is converted to a program portion compatible with FB IEC61131 syntax and the program portion compatible with FB IEC61131 syntax is pasted to the IEC61131 text-edit area designated by the cursor.
[0048] IEC61131 has very particular syntax for calling function (FC) and function block (FB), which is greatly different to other high-level program. The method of the present invention converts a dragged source to an IEC61131-syntax program portion corresponding to the dragged source when the dragged source is feasible to drop. The IEC61131-syntax program portion contains IEC61131 text program and text arguments to facilitate the programming drafting of programmer.
[0049] Moreover, the programmer does not need to memorize the IEC61131 syntax and the programming efficiency can be enhanced.
[0050] Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.
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A method edits a PLC program in a computer with a pointing device such as a mouse. When a drag-and-drop operation is detected, a dragged source is identified. When the dragged source is from libraries, the dragged source is optionally converted into an IEC61131-syntax program portion according to the type of the libraries, namely, function or function block. When the dragged source is a POU (Programming Organization Unit), the dragged source is optionally converted into an IEC61131-syntax program portion according to the source POU type, the currently-edited POU type and criterion of forbidding recursion call. When the drag and drop operation is not feasible, the shape of mouse cursor is changed to remind user. The method of the present invention can advantageously convert items in libraries and POU into IEC61131-syntax program portion to facilitate the PLC programming task.
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FIELD OF THE INVENTION
The present invention relates generally to the field of curtain coating and, more particularly, to methods and apparatus for establishing a uniform wetting line on the back surface of a curtain coating hopper lip.
BACKGROUND OF THE INVENTION
The technique of curtain coating is widely used in the industry of manufacturing photographic films and papers. Typically, a curtain coating apparatus comprises a feed system in the form of one or more slots fed with photographic emulsions and from which the photographic emulsions flow in the form of one or more layers which are superimposed on a slightly inclined plane. The photographic layers then flow onto a lip, where they leave the coating device to form a liquid curtain in substantially vertical free fall. The free-falling curtain is deposited on a moving support web typically while the web is supported on a driven roller. Structurally, the lip is substantially vertical and has a front face on which the layers of photographic emulsion flow, and a rear face forming, with respect to the front face, an angle which is typically around 30° to 45°. The bottom edge of the front face and the bottom edge of the rear face are separated by a bevel, the width of which varies overall between 0.1 mm and 2.5 mm. For applications of this type, the flow rates (per unit width of the lip) vary from 0.6 cm 2 /s to 6 cm 2 /s. The viscosity of the photographic layers varies from 0.005 to 3 poise. All these quantities are, of course, mentioned only by way of reference.
Such curtain coating systems have been the subject of numerous patents. By way of example, reference can be made to the European Patent No. EP-A-107 818; U.S. Pat. No. 4,510,882, U.S. Pat. No. 3,632,374; U.S. Pat. No. 3,867,901; and French Patent No. FR-A-2 346 057.
One condition that a curtain coating system can be particularly sensitive to (notably for photographic applications for which uniformity of coating is essential) is the formation of a curtain that is not uniform and homogeneous. This is because a non-uniform curtain creates streaks on the photographic product. That is, the coating is applied to the support web with variations in thickness across the width of the support web. These variations have an appreciable effect on the photographic properties of the film and consequently it is important to minimize such variations.
U.S. Pat. No. 5,725,666 to Baumlin, entitled “Method and Apparatus for Improving the Uniformity of a Liquid Curtain in a Curtain Coating System,” teaches a tool for creating a uniform wetting line on the rear face of the lip of a curtain coater. A perspective view of the tool is shown in FIG. 1 . The device comprises two fingers 1 , 2 mounted on a frame 3 . Each of the fingers 1 , 2 defines a first surface 4 , 5 designed to be brought to bear on the front face of the lip of the coating device, and a second or rear surface 6 , 7 designed to be applied substantially to the rear face of the lip. The first surface forms, with respect to the second surface, an angle substantially equal to the angle formed by the front and rear faces of the lip. Generally, the angle between the two surfaces varies from 30° to 45°. The height of the rear surface 6 , 7 of each of the fingers is at least equal to the height over which it is intended that the liquid should wet the rear face of the lip.
During operation, an operator applies the wetting device to the lip of the coating device and slides it so as to cause it to travel at least once over substantially the whole width of the lip. Thus, the rear surface 6 , 7 of each of the fingers is applied opposite the rear face of the lip and forces the liquid to wet the rear face of the lip over a height greater than its natural wetting height. There are some problems associated with the use of the device taught by Baumlin. Operator intervention is required. Operation of the tool is manually intensive. Operation of the tool results in generating substantial liquid waste at startup.
U.S. Pat. No. 5,759,633 to Baumlin et al. and entitled “Method for Improving the Uniformity of a Liquid Curtain in a Curtain Coating System,” teaches a method for improving curtain uniformity by forming a liquid curtain over the front face of a lip, progressively reducing the flow rate over the lip to a set value for a period of time so that the rear face of the lip is wet to a greater height, and increasing the flow rate to defined coating conditions. According to the teachings of Baumlin et al., there is initially a liquid composition with a high flow rate (6 cm 2 /s) and a low viscosity (6.5×10 −3 P, which typically corresponds to water at 40° C. to which surfactants are added to facilitate the formation of the curtain). The flow rate is reduced (1.5 to 2 cm 2 /s) so as to attain the flow rate level of a wettability window defining a flow rate and viscosity region within which the liquid composition wets the rear face of the lip over a height greater than the natural wetting height over which the coating composition would wet under the operating coating conditions (50×10 −2 P at a flow rate of 4 cm 2 /s). There is a progressive change from water to the photographic composition, while the flow rate is held substantially at the reduced value. The change from water to the photographic composition results in an increase in viscosity, which takes place progressively so that the process stays within the wettability window for a sufficiently long period (generally longer than 1second). The viscosity of the coating composition continues to increase outside the conditions of the wettability window. The flow rate is then increased to attain the coating rate. The wetting of the rear face of the lip remains uniform and has an average height of around 0.1 mm.
The location and size of the wettability window are, to a large extent, dependent on the geometry of the lip. Baumlin et al. teaches that for each type of lip there is a corresponding wettability window.
There are some drawbacks associated with the method taught by Baumlin et al. First, the method requires that water precede the introduction of product solutions on the slide surface of the curtain coating apparatus. Further, it is difficult to control the flow rates of the various coating layers in conjunction with the viscosity. The method relies on establishment of the wetting line to substantially wet the back of the lip uniformly across the entire width of the lip. There is also the dependence of the wettability windows on lip geometry requiring that a wettability window be established for each coating lip of different geometry.
Baumlin et al. also teaches a second embodiment of the method. According to this embodiment, a solution of gelatin and surfactant having a viscosity of 0.03P is used. Initially, the curtain is established with a high flow rate (around 6 cm 2 /s). The rate is then reduced to about 1.5 cm 2 /s, producing a significant wetting of the rear face of the lip. These conditions are maintained for a few seconds, and the flow rate is again increased to 6 cm 2 /s. This embodiment of Baumlin et al. has drawbacks similar to those discussed above.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method and apparatus for generating a uniform wetting line on the rear face of a curtain coating hopper lip.
It is a further object of the present invention to provide a method and apparatus for generating a uniform wetting line on the rear face of a curtain coating hopper lip which is not dependent on wettability windows and hopper lip geometry.
Yet another object of the present invention is to provide method and apparatus for generating a uniform wetting line on the rear face of a curtain coating hopper lip which can be automatically actuated and minimizes waste.
Still another object of the present invention is to provide a method and apparatus for generating a uniform wetting line on the rear surface of a curtain coating hopper lip which does not require physical contact between the apparatus and the hopper lip.
Briefly stated, the foregoing and numerous other features, objects and advantages will become readily apparent upon a review of the detailed description, claims and drawings set forth herein. These features, objects and advantages are accomplished by using a movable trough positioned in close proximity to the hopper lip. The movable trough can be pivoted or moved linearly into a position such that the hopper lip resides proximate to the movable trough. The curtain coating apparatus is then started and the coating solution leaving the hopper lip is intercepted by the trough. The coating solution flowing over the lip fills and floods the movable trough. The flooding of the trough forces the coating solution to substantially wet (to a height on the back side of the lip significantly higher than that of natural product flow) the back side of the hopper lip. The movable trough is then retracted from its position immediately beneath the hopper lip and intercepting the coating solution exiting the hopper lip to thereby allow the free-falling curtain to form and begin impingement on the moving support web to be coated. As the curtain forms, the wetting line on the back of the hopper lip naturally retracts toward the tip of the hopper lip thereby forming a uniform wetting line and a uniform curtain.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a prior art device used to achieve a uniform wetting line on the rear surface of a hopper lip of a curtain coating apparatus.
FIG. 2 is a perspective view of a movable trough apparatus of the present invention which can be manually positioned to intercept the coating solution exiting the hopper lip of a curtain coating apparatus, such that the hopper lip is flooded to establish a uniform wetting line on the rear surface of the hopper lip.
FIG. 3 is a side elevational schematic showing the position of the movable trough of the present invention in close proximity to the lip of a curtain coating hopper to thereby cause the lip to flood on the rear face thereof to an elevation higher than the operating wetting line on the rear face.
FIG. 4 is a perspective view of the movable trough of the present invention shown in combination with a curtain coating hopper wherein the movable trough is provided with a motorized system for positioning the trough.
FIG. 5 is a side elevational schematic of the movable trough and system depicted in FIG. 4 .
FIG. 6 is a perspective view of the movable trough of the present invention shown in combination with a curtain coating hopper wherein the movable trough is provided with a first alternative automated and powered positioning system from that depicted in FIGS. 4 and 5.
FIG. 7 is a side elevational schematic of the movable trough and system depicted in FIG. 6 .
FIG. 8 is a perspective view of the movable trough of the present invention shown in combination with a curtain coating hopper wherein the movable trough is provided with a second alternative automated and powered positioning system from that depicted in FIGS. 4 and 5.
FIG. 9 is a side elevational schematic of the movable trough and system depicted in FIG. 8 .
FIG. 10 is a side elevational schematic of the movable trough of the movable trough of the present invention shown in combination with a curtain coating hopper wherein the movable trough is provided with a third alternative automated and powered positioning system from that depicted in FIGS. 4 and 5.
FIG. 11 is a schematic depicting a curtain coating system in combination with the movable trough of the present invention.
FIG. 12 is a rear elevational view of the coating lip showing the relative elevations of the wetting line thereon when the movable trough of the present invention in close proximity to the lip of a curtain coating hopper to thereby cause the lip to flood and the operating wetting line when the movable trough has been retracted.
DETAILED DESCRIPTION OF THE INVENTION
Turning to FIG. 2, there is shown a perspective view of a movable trough system 10 adapted to be used in conjunction with a coating hopper (not shown). The system 10 includes feet 12 adapted to be affixed to the floor of a coating room. Extending up from feet 12 are adjustable legs 14 . Affixed to the top of legs 14 are gussets 16 . There is a frame 18 pivotally attached to gussets 16 by means of pins 20 . An arcuate slot 22 in one or both gussets 16 , in conjunction with pins 24 extending from frame 18 into a respective arcuate slot 22 , serve as travel stops, limiting the amount of travel that frame 18 can be pivoted. Affixed to frame 18 is trough 26 . Through the pivoting movement of frame 18 , trough 26 can be positioned in close proximity to the curtain coating hopper lip Such that the hopper lip resides in or proximate to trough 26 . Positioning of trough 26 can be performed manually by an operator, or can be powered such as through the use of a stepper motor. In either case, it is preferred that the trough position be governed by hard stops to insure that there will be no physical contact between the trough 26 and the coating lip. If positioning of trough 26 is performed manually, then the trough 26 will have to be held in position manually for a short period of time while the channel floods and a uniform wetting line is established. Alternatively, a position locking mechanism can be used (such as substituting threaded bolts and nuts for pins 24 so that the position of trough 26 can be positioned by tightening the nuts on the bolts) to hold the trough 26 in position while the channel floods and the uniform order line is established.
Looking next at FIG. 3 there is shown a cross-sectional view of trough 26 residing proximate to the lip 27 of a curtain coating hopper 29 . Trough 26 includes a channel 28 into which the solution from the hopper lip 27 pours. Preferably, channel 28 is semicircular in cross-section. However, it is believed that a variety of cross-sectional shapes can be employed successfully including V-shaped, square, trapezoidal, rectangular, and arcuate. The rear wall 30 of the trough 26 near the front face 31 of the curtain coating hopper 29 preferably has a beveled surface 32 to reduce the tendency of the coating liquid to splash onto the front face 31 of the hopper 29 . Positioning of the trough 26 is critical. The preferred position is such that the lowest point of the tip of the lip 27 is in the same horizontal plane as the top portion of the trough 26 . Importantly, the travel stops in combination with the adjustable legs 14 prevent the trough 26 from travelling into and damaging the hopper lip.
The width of the trough 26 is preferably approximately two (2) inches narrower than the coating width. Thus, there should be about one (1) inch of spacing between each end of the trough 26 and the curtain edge guide equipment (not shown) although the spacing between each end of the trough 26 and the curtain edge guide equipment can be as little as 0.1 inches. Trough 26 is preferably open at each end thereof, such that the excess coating solution is able to flow out of the ends of the channel 28 . In this way, although channel 28 substantially fills with liquid excess coating solution liquid does not flow over the top surfaces of trough 26 which could result in contamination of the web and backup roller. In addition, the spacing between the ends of trough 26 and the edge guides is sufficient to prevent the edge guides from being contaminated with the coating solution.
The method and apparatus of the present invention is preferably used prophylactically as discussed above. Trough 26 is positioned such that the coating lip 27 resides in or at least proximate to trough 26 prior to the introduction of product solutions to the curtain coating hopper. This can be performed while a pre-product solution fluid (e.g. water) is flowing over the hopper lip, or when no solutions are flowing over the hopper lip 27 . If the trough 26 is moved into position while fluid is flowing over the lip 27 , then trough 26 should be moved at a relatively slow rate of speed (about 1 inch per sec) in order to prevent the fluid splashing onto the front face 31 of the coating hopper 29 . The product solution is introduced into the curtain coating hopper 29 by conventional methods (at coating flow rates or at specific flow rates). Trough 26 is allowed to reside in close proximity to the hopper lip 27 (i.e. breaking the liquid curtain) for approximately 5 seconds. Once product solution flow has been established throughout the entire hopper 29 , channel 28 quickly fills, thereby wetting the rear face 33 of the coating lip 27 to an elevation 35 higher than the operating wetting line 37 (see FIG. 12 ). Trough 26 is then retracted and a uniform operating wetting line 37 is established. Trough retraction rate is preferably relatively quick (on the order of magnitude of 12 inches per second). This can be accomplished by releasing the trough position locking mechanism to thereby allow the trough to fall away in an arcuate path under the force of gravity.
The method and apparatus of the present invention can also be used as a corrective tool if wetting line non-uniformities are observed on the back surface 33 of the coating lip 27 . When used as corrective tool, trough 26 begins in the retracted position, that is, not in contact with the liquid curtain (not shown), while the product solution is forming a free-falling curtain. Trough 26 is then moved into a position in close proximity to the coating hopper lip 27 and intercepting the free-falling curtain. The action of placing the trough 26 in close proximity to the hopper lip 27 while product solution is flowing over the lip 27 is performed slowly—at a rate of approximately 1 inch per sec, such that fluid does not splash on the front face 31 of the hopper 29 . With the free-falling curtain intercepted by trough 26 , channel 28 quickly fills, thereby wetting the rear face 33 of the coating lip 27 to an elevation higher than the operating wetting line. Trough 26 is then retracted and a uniform operating line is established. The trough 26 is allowed to reside in close proximity to the hopper lip 27 (i.e. breaking the liquid curtain) for approximately 5 seconds, then the trough 26 is retracted from its position in close proximity to the lip. Retraction of the trough 26 should again be done quickly such as by releasing trough 26 to allow to fall away in an arcuate path under the force of gravity.
Although the trough 26 depicted in FIG. 2 is described herein as being manually positioned, it should be apparent to those skilled in the art that an automated driving mechanism can be employed to position trough 26 proximate to a coating lip 27 . A variety of different rotational and or linear driving mechanisms can be used to position trough 26 . Looking next at FIGS. 4 and 5, there is shown an alternative embodiment of the present invention wherein the means for positioning of a trough 40 is through a powered mechanism. Trough 40 is substantially identical to trough 26 . A motor 42 having a drive shaft 44 extending therefrom is used to drive the movement of trough 40 in an arcuate path. There are bearings 46 providing rotational support for drive shaft 44 . Motor 42 and bearings 46 are supported by a support frame (not shown). Affixed to drive shaft 44 arc arms 48 which support trough 40 . Motor 42 drives rotation of drive shaft 44 to cause trough 40 to be moved in an arcuate path either into close proximity with the coating lip 50 of coating hopper 52 to thereby be in position to intercept the free-falling curtain, or away from coating lip 50 such that the freefalling curtain is not intercepted by trough 40 . In such manner, trough 40 can be used prophylactically or as a corrective tool as described above with reference to trough 26 to establish a uniform wetting line on the back surface of coating lip 50 .
Turning next to FIGS. 6 and 7, there is shown yet another alternative embodiment of the present invention similar to that shown in FIG. 4 and 5. The positioning of trough 60 is driven by a linear actuator 62 . The piston 64 of linear actuator 62 has pivotally attached thereto an arm 66 . Attached to the opposite end of arm 66 is shaft 68 . Shaft 68 is supported for rotational movement by bearings 70 . Bearings 70 arc supported by a frame (not shown). Affixed to shaft 68 are arms 72 which support trough 60 . Linear actuator 62 drives rotation of shaft 68 to cause trough 60 to be moved in an arcuate path either into close proximity with the coating lip 74 of coating hopper 76 to thereby be in position to intercept the free-falling curtain, or away from coating lip 74 such that the free-falling curtain is not intercepted by trough 60 . In such manner, trough 60 can be used prophylactically or as a corrective tool as described above with reference to trough 26 to establish a uniform wetting line on the back surface of coating lip 74 .
FIGS. 8 and 9 schematically depict yet another alternative embodiment for driving the movable trough of the present invention. The trough 80 (which is substantially identical to trough 26 ) is mounted on a support frame 82 . Support frame 82 is in turn affixed to a pair of vertical guide bars 84 . Support frame 82 includes a cantilevered section 86 . A linear actuator 88 is provided wherein the piston 90 thereof engages a cantilevered section 86 . In such manner, linear actuator 88 can raise and lower support frame 82 with vertical guide bars 84 sliding in bearings 92 . Bearings 92 are supported by means not shown. It should be noted that the curtain coating hopper 94 moves between a coating position 96 in a preparation position 98 . When the hopper 94 is in the coating position 96 , the free falling curtain exiting lip 99 will impinge upon a moving web supported on a coating roller (not shown). Thus, in order to establish a uniform wetting line on the back surface of lip 99 , the coating hopper 94 is moved into the preparation position 98 . With the coating hopper 94 in the preparation position 98 , linear actuator 88 is used to drive frame 82 vertically upward to thereby position trough 80 proximate to lip 99 . In such manner, coating liquid or the startup liquid flowing over lip 99 floods the channel of trough 80 thereby establishing a wetting line on the back surface of lip 99 which is higher than the operating wetting line on the back surface of lip 99 . Linear actuator 88 than lowers frame 82 and trough 80 away from lip 99 . Then, with liquid still flowing from hopper 94 over lip 99 , hopper 94 it is retracted to the operating position 96 and curtain coating of the moving web is begun.
Looking next at FIG. 10, still another alternative embodiment for driving the movement of the movable trough is depicted. In this embodiment the position of trough 100 is driven by the movement of the coating hopper 102 . There is a bracket 104 mounted to the coating hopper 102 . Bracket 104 includes a curved engaging surface 108 . Trough 100 is mounted on beams 106 which extend from an axle not shown. The axle is rotatably supported in bearings 110 which are in turn supported by means not shown. Extending from each end of the axle are struts 112 . In operation, when hopper 102 is moved from the operating position 114 to a preparation position 116 the curved engaging surfaces 108 of brackets 104 engage struts 112 for driving struts 112 to an upright position thereby causing beams 106 to be pivoted upwards. In such manner, trough 100 is raised to be positioned proximate to lip 118 . Once the flow of liquid from lip 118 floods the channel in trough 100 thereby establishing a wetting line on the back surface of lip 118 , hopper 102 is retracted to the operating position 114 so that coating of the moving web can be performed.
Generally, the movable trough 26 , 40 , 60 , 80 , 100 of the present invention is used when the coating hopper is in a preparation position as discussed above with reference to FIGS. 1 through 10. Looking at FIG. 11, there is schematically depicted a curtain coating system with the movable trough of the present invention 26 , 40 , 60 , 80 , 100 . When the coating hopper 120 is in the preparation position 122 , fluid flowing over the coating lip 124 will be collected in a preparation trough 126 or drain collection trough 128 . Therefore, fluid exiting channel 28 at the ends thereof will also be captured in the preparation trough 126 or drain collection trough 128 . Once a wetting line has been established on the back face of lip 124 , the movable trough ( 26 , 40 , 60 , 80 , 100 ) is retracted, and the coating hopper 120 is retracted to an operating position 130 . In the operating position, the coating lip 124 is positioned above a moving web 132 , which is supported on a coating roll 134 . The solution is captured by the start/finish pan 136 until the coating is ready to begin.
Those skilled in the art will recognize that, typically, coating hoppers in a curtain coating operation are used to coat the moving web with a composite layer. The composite layer is comprised of a plurality of superimposed individual layers. In the practice of the method of the present invention it is generally preferred to position the movable trough in close proximity to the lip prior to the introduction of the product solution. The trough is preferably not moved away from the lip until all product coating layers have been fully established through the coating hopper.
From the foregoing, it will be seen that this invention is one well adapted to obtain all of the ends and objects hereinabove set forth together with other advantages which are apparent and which are inherent to the apparatus.
It will be understood that certain features and subcombinations are of utility and may be employed with reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth and shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
PARTS LIST
1 finger
2 finger
3 frame
4 first surface
5 first surface
6 second or rear surface
7 second or rear surface
10 movable trough system
12 feet
14 adjustable legs
16 gussets
18 frame
20 pins
22 arcuate slot
24 pins
26 trough
27 hopper/coating lip
28 channel
29 curtain coating hopper
30 rear wall
31 front face
32 beveled surface
33 rear face
35 elevation
37 operating wetting line
40 trough
42 motor
44 drive shaft
46 bearings
48 arms
50 coating lip
52 coating hopper
60 trough
62 linear actuator
64 piston
66 arm
68 shaft
70 bearings
72 arms
74 coating lip
76 coating hopper
80 trough
82 support frame
84 vertical guide bars
86 cantilevered section
88 linear actuator
90 piston
92 bearings
94 curtain coating hopper
96 coating position
98 preparation position
99 exiting lip
100 trough
102 coating hopper
104 bracket
106 beams
108 curved engaging surface
110 bearings
112 struts
114 operation position
116 preparation position
118 coating lip
120 coating hopper
122 preparation position
124 coating lip
126 preparation trough
128 drain collection trough
130 operating position
132 moving web
134 coating roll
136 start/finish pan
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A movable trough is taught for establishing a uniform wetting line on the rear face of a curtain coating hopper lip. The trough can be pivoted or moved linearly into a position such that the hopper lip resides in or proximate to the movable trough. The curtain coating apparatus is then started and the coating solution leaving the hopper lip is intercepted by the trough. The coating solution flowing over the lip fills and floods the movable trough. The flooding of the trough forces the coating solution to substantially wet (to a height on the back side of the lip significantly higher than that of natural product flow) the back side of the hopper lip. The movable trough is then retracted from its position immediately beneath the hopper lip and intercepting the coating solution exiting the hopper lip to thereby allow the free-falling curtain to form and begin impingement on the moving support web to be coated. As the curtain forms, the wetting line on the back of the hopper lip naturally retracts toward the tip of the hopper lip thereby forming a uniform wetting line and a uniform curtain.
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BACKGROUND OF INVENTION
PRIOR ART
This invention relates to the manufacture of 8-methoxypsoralen and is directed to improvements in a process in which pyrogallol is converted to 8-methoxypsoralen in six unit process steps.
Lagercrantz, Acta Chemica Scandinavica Vol. 10, (1956) pp. 647-654 reports the preparation of 8-methoxypsoralen in the following six unit process steps beginning with pyrogallol:
(1) Pyrogallol is reacted with chloracetic acid in the presence of phosphorus oxychloride to form ω-chloro-2,3,4-trihydroxyacetophenone,
(2) which product is cyclized by the splitting off .[.hydrochloric acid.]. .Iadd.of hydrogen chloride .Iaddend.to form 6,7-dihydroxycoumaranone,
(3) which product is hydrogenated with hydrogen over a palladium catalyst in acetic acid at 1 atmosphere and 65° C. .[.,.]. .Iadd.to form 6,7-dihydroxy-2,3-dihydrobenzofuran, .Iaddend.
(4) which product is reacted with malic acid in the presence of concentrated sulphuric acid to form .Badd..[.2,3-dihydroxanthotoxol.]..Baddend. .Iadd.4',5'-dihydroxanthotoxol, .Iaddend.
(5) which product is methylated using diazomethane to form .Badd..[.2,3-dihydroxanthotoxin.]..Baddend. .Iadd.4',5'-dihydroxanthotoxin, .Iaddend.
(6) which product is dehydrogenated with palladium catalyst in boiling diphenyl ether to form the desired 8-methoxypsoralen (xanthotoxin).
Davies et al., J. Chem. Soc., (1950), 3202-6 reports the first two of these unit process steps and Spath et al., Ber. 69, (1936), 767-770, reports the last four of these steps.
The overall yield in these prior art processes is less than about 3 percent. This is due to the relatively low yield in some or most of the unit process steps. The problem steps apparently are the hydrogenation step (3) and the dehydrogenation step (6). In regard to the former, Spath obtained 33 percent yield and Lagercrantz, 50 percent yield. However, Lagercrantz points out that this unit process is highly critical, that the hydrogenation also involves enolization of the oxo group and that the starting 6,7-dihydroxycoumaran-3-one (hereinafter referred to as 6,7-dihydroxycoumaranone) must be "very pure" in order to avoid poisoning of the catalyst. He suggests recrystallization several times with active carbon. In regard to the dehydrogenation, the best yield reported is 37 percent. This, coupled with the relatively low yields reported for steps 1, 3, and 4, makes the overall yield of the prior art process less than about 3 percent.
OBJECT OF THE INVENTION
It is an object of the invention to provide an improved process for making 8-methoxypsoralen. A further object of the invention is to provide a process which avoids the disadvantages of the prior art. A further object of the invention is to provide an improved process for the hydrogenation of 6,7-dihydroxycoumaranone. A further object of the invention is to provide an improved process for dehydrogenation of .Badd..[.2,3-dihydroxanthotoxin.]. .Baddend..Iadd.4',5'-dihydroxanthotoxin. .Iaddend.A further object of the invention is to provide an improved overall process. Further objects will appear as the description proceeds.
SUMMARY OF THE INVENTION
The invention relates to improvements in a process for making 8-methoxypsoralen from pyrogallol in the following steps:
(1) reacting pyrogallol with chloracetic acid to form ω-chloro-2,3,4-trihydroxyacetophenone,
(2) heating ω-chloro-2,3,4-trihydroxyacetophenone in the presence of a hydrogen chloride acceptor to form 6,7-dihydroxycoumaranone,
(3) hydrogenating 6,7-dihydroxycoumaranone to form 6,7-dihydroxy-2,3,-dihydrobenzofuran,
(4) reacting 6,7-dihydroxy-2,3,-dihydrobenzofuran with malic acid to form .Badd..[.2,3-dihydroxanthotoxol.]..Baddend. .Iadd.4',5'-dihydroxanthotoxol, .Iaddend.
(5-6) methylating and dehydrogenating to convert .Badd..[.2,3-dihydroxanthotoxol.]. .Iadd.4',5'-dihydroxanthotoxol .Iaddend.to 8-methoxypsoralen,
which improvements comprise a novel procedure for effecting the hydrogenation, a novel procedure for effecting the dehydrogenation, and a general overall combination of particular unit process steps leading to improved overall yield.
In steps 5-6, the methylation can be done first and then the dehydrogenation, or the dehydrogenation first and then the methylation. The latter is of advantage where a tagged or labeled product is desired. Thus, if .Badd..[.2,3-dihydroxanthotoxol.]..Baddend. .Iadd.4',5'-dihydroxanthotoxol .Iaddend.is first converted to xanthotoxol, the xanthotoxol can be methylated with a tagged or labeled methylating agent to form the desired tagged or labeled 8-methoxypsoralen.
Steps 1 and 2 are carried out as described in Lagercrantz and Davies and comparable yields are obtained. Step 3, however, has been modified to give substantially greater yields and to make it possible to avoid the necessity for repeated recrystallization of the starting 6,7-dihydroxycoumaranone. In Step 4, a low reaction temperature and a simplified work-up gives better yields. In Step 5-6, the methylation, the expensive and highly explosive and dangerous diazomethane is replaced by dimethyl sulphate without sacrificing yield and in the dehydrogenation, Step 5-6, use of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone as a dehydrogenation agent results in a two-fold increase in the unit yield of 8-methoxypsoralen. Still higher unit yields are obtained if chlorobenzene is used as the solvent. With these improvements, overall yields greater than 10 percent are obtainable.
The hydrogenation of 6,7-dihydroxycoumaranone in accordance with the invention is effected in a low pressure hydrogenation unit under an absolute pressure of hydrogen of about 2 atmospheres and a temperature of about 100° C. in a mixture of acetic acid and ethyl acetate, advantageously, in the proportions of about five percent to about thirty percent acetic acid. Higher percentages of acetic acid can be used, but only with sacrifice in yields. Also the ethyl acetate can be substituted by other solvents like methanol and ethanol but only with a sacrifice in yields. Higher or lower pressures, say, from about 1 to about 10 atmospheres absolute pressure, and higher or lower temperature, say, from about 65° C. to about 150° C., can be used in accordance with practices already well known for low pressure hydrogenation.
The reaction mixture is cooled and the catalyst is filtered off. The solvent is distilled under reduced pressure leaving an oil which can be used as the starting material in the next step. If desired residual acetic acid can be removed by azeotropic distillation with benzene. Finally, the product is crystallized from an inert solvent, such as benzene, to yield a crude product which can be used directly in the next step. If desired, however, the crude material can be further recrystallized. For this crystallization and recrystallization, any inert solvent for the produced .Badd..[.6,7-dihydroxy-2,3-benzofuran.]..Baddend. .Iadd.6,7-dihydroxy-2,3-dihydrobenzofuran, .Iaddend.can be used but those like benzene, toluene, chlorobenzene, petroleum ether, ethylene chloride, cyclohexane, and the like, in which the product has limited solubility are preferred.
The starting material for Step 3, 6,7-dihydroxycoumaranone, is obtained by refluxing ω-chloro-2,3,4-trihydroxyacetophenone in ethanol in the presence of sodium acetate, distilling off the ethanol and crystallizing the product from water.
The crude product resulting from this crystallization is used directly in the .[.hydrogen.]. .Iadd.hydrogenation .Iaddend.step but, if desired, can be recrystallized from acetone or other suitable inert solvent in which the 6,7-dihydroxycoumaranone has limited solubility.
Alternatively, the cyclization can be effected by heating in the presence of a hydrogen chloride acceptor in a suitable solvent or vehicle. Suitable such hydrogen chloride acceptors include potassium carbonate and exchange resins such as Dow-X 1, Imac A-21, Permutic ES, Amberlite IRA-410, and the like. Ordinarily these ion exchange resins comprise a cross-linked polystyrene base or like cross-linked resin base, substituted by a trimethylbenzylammonium group or like quaternary ammonium groups. Such hydrogen acceptors have the advantage that they are easily separated from the reaction mixture by filtration.
The 6,7-dihydroxy-2,3-dihydrobenzofuran from Step 3 is reacted with malic acid in concentrated sulpuric acid at a temperature of about 80° C. to not more than about 100° C. This temperature, which is substantially lower than that used in the prior art, makes it easier to control foaming and this, coupled with slightly different work-ups, results in higher yields.
The low temperature is determined by that at which the reaction proceeds as evidenced by the evolution of gas, presumably carbon monoxide, and the higher temperature by that at which excessive tar does not form. The action is continued until substantial evolution of gas ceases. Ten minutes or so will ordinarily suffice at temperatures about 100° C., but longer periods may be required at lower temperatures. The desideratum is as low a temperature and as short a time as possible since longer times and higher temperatures result in the formation of more tar and lower yields.
Advantageously, the sulphuric acid is preheated to or near the desired reaction temperature, say to between about 70° C. and about 100° C. To the hot sulphuric acid, a mixture of 6,7-dihydroxy-2,3-dihydrobenzofuran and malic acid is added with stirring while maintaining the temperature between about 80° C. and about 100° C. The proportions are the stoichiometric, advantageously with a slight excess, say up to 10 or 20 percent excess, of malic acid. As the sulfuric acid acts primarily as a dehydrating agent, the amount is not critical as long as sufficient is present for this purpose and to give an easily workable and handleable reaction mixture. The reaction mixture, however obtained, is cooled and poured into ice water and extracted with chloroform. Advantageously, the ice water and the chloroform are premixed so that the product, .Badd..[.2,3-dihydroxanthotoxol.]..Baddend. .Iadd.4',5'-dihydroxanthotoxol, .Iaddend.is extracted into the chloroform before it becomes contaminated with or occluded in any tar that is precipitated.
The chloroform extract is dried with sodium sulphate, concentrated to or near dryness, and washed with a relatively large volume of an inert non-solvent, for example, hexane, filtered and dried. Any inert non-solvent for the product can be used in place of the hexane, for example, any aliphatic or cycloaliphatic hydrocarbon, since it is used here primarily for its physical effect. The resulting crude product is used directly in the following step but, if desired, can be recrystallized from water.
The resulting .Badd..[.2,3-dihydroxanthotoxol.]..Baddend. .Iadd.4',5'-dihydroxanthotoxol .Iaddend.is now methylated with dimethyl sulphate in an inert solvent such as acetone in the presence of an acid acceptor, for example, potassium carbonate. The reaction mixture is drowned in a dilute sodium hydroxide solution and the product recovered by filtration. The crude product thus obtained can be used directly in the next step but, if desired, can be recrystallized from benzene, or like inert-solvent in which .Badd..[.2,3-dihydroxanthotoxin.]..Baddend. .Iadd.4',5'-dihydroxanthotoxin .Iaddend.has limited solubility.
The .Badd..[.2,3-dihydroxanthotoxin.]..Baddend. .Iadd.4',5'-dihydroxanthotoxin .Iaddend.thus obtained is then dehydrogenated. This advantageously is effected by heating the .Badd..[.2,3-dihydroxanthotoxin.]..Baddend. .Iadd.4',5'-dihydroxanthotoxin .Iaddend.with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in a substantially inert solvent, for example, toluene or chlorobenzene, advantageously at reflux, until substantial dehydrogenation is obtained. The 2,3-dichloro-5,6-dicyano-hydroquinone formed and any residual 2,3-dichloro-5,6-dicyano-1,4-benzoquinone are removed and the product taken up in chloroform and recovered therefrom. If substantial amounts of the residual 2,3-dichloro-5,6-dicyano-1,4-benzoquinone are present, it is desirable to convert this to the corresponding hydroquinone with sodium dithionite, dissolve the hydroquinone in aqueous sodium bicarbonate, and extract the sodium bicarbonate solution with chloroform to recover the 8-methoxypsoralen which can be recovered by drying over sodium sulphate and concentrating to dryness. The resulting product can then be recrystallized from benzene or any suitable inert solvent in which 8-methoxypsoralen has limited solubility. If there is little residual 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, the reaction mixture can be cooled and the precipitated hydroquinone filtered off and the reaction mixture, i.e., the filtrate, then extracted with chloroform. If desired, the filter cake can be extracted with benzene or like solvents such as chlorobenzene, toluene, and the like, for example, by refluxing the filter cake in the solvent and then adding the extract to the reaction mixture filtrate prior to the chloroform extraction. The chloroform solution is then washed successively with dilute sodium bisulfite solution, dilute sodiium bicarbonate solution, and water and dried over sodium sulfate. The resulting chloroform solution is then concentrated by distillation until the product precipitates and an inert non-solvent such as hexane or like aliphatic or cycloaliphatic hydrocarbon is added to cause further precipitation of the product and the product is filtered. If desired, the product can be further purified by redissolving it in chloroform, or chloroform containing a minor amount of ethyl acetate, passing the solution over an alumina column concentrating the effluent until crystallization takes place, adding hexane or like solvent further to cause precipitation of the product, and filtering the solution.
If desired, the last two steps, namely, the methylation and the dehydrogenation can be inverted. In other words, the .Badd..[.2,3-dihydroxanthotoxol.]..Baddend. .Iadd.4',5'-dihydroxanthotoxol, .Iaddend.instead of being methylated, is dehydrogenated to form xanthotoxol and the resulting xanthotoxol methylated to form 8-methoxypsoralen. The same reaction conditions and work-ups can be used as given above for the methylation and dehydrogenation.
DETAILED DESCRIPTION OF THE INVENTION
The following examples are given by way of illustration only. Parts and percentages are by weight unless otherwise specified.
EXAMPLE 1
8-Methoxypsoralen
Part A:
ω-Chloro-2,3,4-trihydroxyacetophenone
A flask equipped with a stirrer and protected from atmospheric moisture was charged with 126.1 g of pyrogallol, 101.1 g chloracetic acid and 101.2 g of phosphorus oxychloride.
The contents were stirred and heated at 60° C. until stirring became quite difficult (approximately 4 hours), hydrogen chloride was evolved during the reaction. The reaction mixture was then cautiously hydrolyzed with ice water (750 ml/mole), and the resulting mixture was heated to 70° C. for 30 minutes and then cooled to 0° C. After stirring at 0° C. for 12 hours, the mixture was filtered to collect the product. The cooled product was washed with a small amount of ice water and dried. Dark tan crystals of ω-chloro-2,3,4-trihydroxyacetophenone melting at 166°-8° C. were obtained in a yield of 55 percent (111 g/mole). This crude product was used directly in the next step without further purification.
On successive replications, the yield varied from 45 to 55 percent.
The crude product on recrystallization from water gave light tan crystals melting at 168°-170° C.
Part B:
.Badd..[.6,7-Dihydroxycumaranone.]..Baddend. .Iadd.6,7-Dihydroxycoumaranone .Iaddend.
A mixture of 1.5 l of ethanol (2B alcohol), 249.1 g sodium acetate and 202.6 g ω-chloro-2,3,4-trihydroxyacetophenone from Part A was refluxed for six hours. The ethanol was distilled off and the residue was treated with 1.5 l of water and was cooled with stirring to -5° to -0° C., filtered, and the product washed with a small amount of ice water and air dried. There was obtained 141 g (85 percent yield), of crude 6,7-dihydroxycoumaranone melting at 230°-2° C. This crude product was used in Step C.
On successive replications, the yield varied from 76 to 85 percent.
On recrystallization from acetone there were obtained light tan crystals melting at 232°-4° C.
Part C:
6,7-Dihydroxy-2,3-dihydrobenzofuran
A low pressure hydrogenation unit was charged with 4 l of a 20 percent acetic acid solution in ethyl acetate, 55 g of 10 percent palladium on carbon and 166.1 g of the crude 6,7-dihydroxycoumaranone of Part B. Hydrogen was admitted under 30 psi .[.guage.]. .Iadd.gauge .Iaddend.pressure and at a temperature of 100° C. until the theoretical amount .[.(1 mole).]. .Iadd.(2 moles) .Iaddend.of hydrogen was absorbed and further take-up had stopped. This took approximately 12 hours. The reaction mixture was then cooled and filtered to remove the catalyst. The filtrate was distilled under reduced pressure leaving an oil. This oil was taken up in 1 liter of benzene and the benzene distilled off to remove residual acetic acid as a benzene-acetic acid azeotrope. This was repeated two times. Finally the residue was taken up in 500 ml of benzene and the resultant cooled to precipitate out the product. On filtering and washing with a little cold benzene, there was obtained 126 g (83 percent yield), of crude 6,7-dihydroxy-2,3-dihydrobenzofuran melting at 97°-9° C., which was transferred directly as the starting material .[.as.]. .Iadd.of .Iaddend.Step D.
On successive replications, the yield varied from 74 to 83 percent.
On recrystallization from benzene, there were obtained off-white crystals melting at 104°-6° C.
If all the acetic acid is not removed in the azeotropic distillation, an oily residue may remain which is not taken up by the benzene. This oily residue is high in product and can be used successfully in the next step.
Part D:
.Badd..[.2,3-Dihydroxanthotoxol.]..Baddend. .Iadd.4',5'-Dihydroxanthotoxol .Iaddend.
A flask equipped with a stirrer and port thermometer was charged with 460 ml of concentrated sulphuric acid and the temperature was brought to 70° C. A mixture of 152 g of 6,7-dihydroxy-2,3-dihydrobenzofuran from Part C and 154 g of malic acid was cautiously added to the sulphuric acid with stirring while the temperature was brought to 100° C. Carbon monoxide was evolved during the reaction and caused some foaming of the reaction mixture. The reaction mixture was maintained at 100° C. for 10 minutes at which time the bulk of the gas evolution had ceased. The mixture was then cooled to room temperature and poured into a stirred mixture of 6 liters of water and 12 liters of chloroform. Sometimes material separates which generally remains suspended in the aqueous layer. The chloroform layer was separated and the aqueous .Iadd.layer .Iaddend.re-extracted two more times with chloroform, first with 6 liters and second with 2 liters. To the combined chloroform extract after drying with sodium sulphate and concentrating the combined chloroform extracts to near dryness, was added 1 liter of hexane and the product filtered and dried. There was obtained 1.2 g (55 percent yield), of crude .Badd..[.2,3-dihydroxanthotoxol.]..Baddend. .Iadd.4',5'-dihydroxanthotoxol .Iaddend.melting at 190°-3° C. This crude product was used in Step E.
On successive replications, the yield varied from 45 to 55 percent.
Upon recrystallization from water, there was obtained off-white crystals melting at 191°-3° C.
Part E:
.Badd..[.2,3-Dihydroxanthotoxin.]..Baddend. .Iadd.4',5'-Dihydroxanthotoxin .Iaddend.
A reaction mixture of 204 g of .Badd..[.2,3-dihydroxanthotoxol.]..Baddend. .Iadd.4',5'-dihydroxanthotoxol .Iaddend.of Part D, 136 g of dimethyl sulphate, 828 g of potassium carbonate, and 9 liters of acetone was refluxed with stirring for 16 hours. The reaction mixture was then cooled and filtered and the filter cake washed with acetone. The acetone solution was concentrated to approximately 2 liters and poured into 4 liters of 1 percent sodium hydroxide solution with good stirring. The product was filtered and washed with water until the pH was neutral. It was then washed with a little cold acetone and finally air dried. There was obtained 185 g (85 percent yield), of crude .Badd..[.2,3-dihydroxanthotoxin.]..Baddend. .Iadd.4',5'-dihydroxanthotoxin .Iaddend.melting at 158°-160° C. This crude product was used directly in Step F.
On successive replications, the yield varied from 80 to 85 percent.
On recrystallization from benzene, there was obtained a white solid melting at 159°-160° C.
Part F-1:
8-Methoxypsoralen
A reaction mixture of 218 g of .Badd..[.2,3-dihydroxanthotoxin.]..Baddend. .Iadd.4',5'-dihydroxanthotoxin .Iaddend.of Part E, 281 g of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, and 3 liters of toluene was stirred and heated at reflux for 20 hours. The mixture was cooled and poured into 10 liters of 10 percent sodium hydroxide solution containing 5 percent sodium dithionite. The solution was then extracted twice with about 2 liters of chloroform. The combined chloroform extracts were washed with water and dried over sodium sulphate and concentrated to dryness. There was obtained 150 g (70 percent yield), of crude 8-methoxypsoralen which on crystallization from benzene was obtained as white crystals melting at 138°-140° C.
On successive replications, the yield varied from 65 to 70 percent. The overall yield was 13%.
Part F-2:
8-Methoxypsoralen
A reaction mixture of 218 g of .Badd..[.2,3-dihydroxxanthotoxin.]..Baddend. .Iadd.4',5'-dihydroxanthotoxin .Iaddend.of Part E, 250 g of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, and 2 l of chlorobenzene was stirred at reflux for 12 hours. The reaction mixture was cooled and the precipitated hydroquinone filtered off, the filter cake was extracted with 2 l of benzene at reflux, filtered hot and the extract added to the filtrate. Three l of chloroform was then added and the mixture washed, first, with 2 l of 2 percent sodium bisulfite, second, 2 l of 1 percent sodium bicarbonate, and third, 2 l of water, and then dried over sodium sulphate. The dried solution was then concentrated by distillation until the product precipitated, whereupon 500 ml of hexane was added and the product filtered. The product was then dissolved in 4:1 (v/v) chloroform/ethyl acetate and passed over an alumina column (Neutral Alumina, Brockman Activity 1). The effluent was concentrated until crystallization took place. There was then added 500 ml of hexane and the product was recovered by filtration. White crystals of 8-methoxypsoralen melting at 143.5°-145° C. were obtained in 85 percent yield.
On successive replications, yields of 80 to 85 percent were obtained. The overall yield was 15%.
EXAMPLE 2
8-Methoxypsoralen
Part A:
Following the procedure of Part F-2 of Example 1, substituting the .Badd..[.2,3-dihydroxanthotoxin.]..Baddend. .Iadd.4',5'-dihydroxanthotoxin .Iaddend.by the equivalent amount of .Badd..[.2,3-dihydroxanthotoxol.]..Baddend. .Iadd.4',5'-dihydroxanthotoxol .Iaddend.of Part D of Example 1, there is obtained xanthotoxol.
Part B:
Following the procedure of Part E of Example 1, substituting the .Badd..[.2,3-dihydroxanthotoxol.]..Baddend. .Iadd.4',5'-dihydroxanthotoxol .Iaddend.by the equivalent amount of xanthotoxol from Part A above, there is obtained 8-methoxypsoralen.
Part C:
Following the procedure of Part B above, substituting the dimethylsulfate by tagged or labeled dimethylsulfate, there is obtained tagged or labeled 8-methoxypsoralen.
It is to be understood that the invention is not to be limited to the exact details of operation or structure shown as obvious modifications and equivalents will be apparent to one skilled in the art.
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8-Methoxypsoralen is prepared in six steps from pyrogallol including hydrogenation of .[.6,7-dihydroxy-2,3-dihydrobenzofuran.]. .Iadd.6,7-dihydroxycoumaranone .Iaddend.and dehydrogenation of .[.2,3.]. .Iadd.4',5'.Iaddend.-dihydroxanthotoxin. Improvements in these two steps lead to a marked overall increase in yield.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Related Application
[0001] This application is a continuation of and co-owned U.S. patent application Ser. No. 09/668,186, filed with the U.S. Patent and Trademark Office on Sep. 22, 2000, by the inventors herein; which is a division of U.S. patent application Ser. No. 09/124,780, now U.S. Pat. No. 6,533,049 entitled “Mining Drill Steels and Methods of Making the Same”, filed with the U.S. Patent and Trademark Office on Jul. 30, 2001, by the inventors herein; which is a continuation-in-part of U.S. patent application Ser. No. 08/917,623, now U.S. Pat. No. 6,516,904 entitled “Mining Drill Steels and Methods of Making the Same”, filed with the U.S. Patent and Trademark Office on Jul. 23, 1997, by the inventors herein, the specifications of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention disclosed herein relates generally to alloy steels used in drilling operations, more specifically it relates to steel drills normally used for roof bolt operations.
[0004] 2. Background of the Prior Art
[0005] For a number of years mining, particularly coal mining, has been carried out by securing protective plates to the roof of a mineshaft as it is advanced through the earth. Such plates protect the shaft and most importantly protect the miners against a collapse of, or falling of debris from, the roof of the shaft. To secure such protective plates to the mine roof, holes are drilled in the roof. Bolts anchored in the roof secure the protective plates. The bolts may be embedded in resin forced into the hole drilled in the roof or the bolt may be designed to expand to grip in the hole.
[0006] In order to drill holes in the rock strata, a conventional roof-drilling machine is utilized. Typically, these drilling machines include a drive end and utilize drill steel members and a carbide insert or drill bit, generally 1″ in diameter, attached to one end of the final drill steel member to drill the holes in the mine roof. These drill steel members are generally coupled on the other end, e.g. the drive end, by a chuck located on the drilling machine. This attachment provides a means for rotating the drill member and thus the drill bit to remove material and debris from the drilled hole.
[0007] To facilitate the removal of material and debris from the drilled hole, many drilling machines incorporate a vacuum suction collection system wherein the drill steel member is constructed from a hollow steel bar. Connected to the drill bit are one or more lengths of drill steel formed as hollow tubes of a suitable steel material. Such tube, or varying lengths of it, is connected ultimately to the rotating chuck of a drill motor. The chuck itself is connected to a vacuum to draw the dust from the drill bit through the drill tubes into a collector. In this way, the air in the mine is kept relatively free of dust, thus helping to maintain the health of the miners and to lessen the chances of an explosive mixture in the air.
[0008] U.S. Pat. No. 4,226,290 to L. H. McSweeney provides a detailed explanation of the devices and technique of “roof drilling” in coalmines and reference is made to that patent for a more complete explanation.
[0009] In the prior art, the hollow tubes, known as “drill steels” have been formed with flat surfaces, either square or hexagonal, at both ends. Such flat surfaces may be formed on the external surface of the tube or the internal surface, and are used to connect one tube to another, to a drill chuck, or to a drill bit.
[0010] As explained in U.S. Pat. No. 4,226,290, the drill steels have different functions and are assigned different tasks. The drill steel may have a squared end or a “hands off” hexagonal end for engaging in the drive system. Various couplings and collars may be used and assembled by press fitting on the ends of the steels. Thus, a finisher is a rod having two hexagonal ends with one end engaging a drill bit while the other end fits into the female end of another length of drill steel called a pusher. The pusher, or another piece called a starter, may be engaged at one end in a drive system. A special purpose drill steel is also used to engage the roof bolt for insertion into the drilled hole.
[0011] In accordance with one conventional manufacturing technique, a drill steel section is cut to the desired drilling length for a particular member and then the ends of the section are typically beveled to facilitate welding of a component part onto the corresponding end of the drill steel section. Individual components are initially cast or otherwise fabricated by forging internal or external flat surfaces and then welded directly to an appropriate end of the corresponding drill steel section. Although such completed drill steel members, including the starter, driver, extension, and finisher, are generally easy to manufacture, many drawbacks for the manufacturing method exist.
[0012] First, such forging process has the adverse effect of causing a stressed, weakened portion to be created along the length of the drill steel adjacent to the forged surface. Additionally, the effects of heat produced during the welding of components to drill steel sections results in the production of stress fractures, cracks and other residual stresses as a result of the intense heating (welding temperatures can exceed hundreds of degrees of Fahrenheit) and cooling of the steel. Fractures and cracks are produced not at the heat point but typically at the transfer points, or heat-affected zones, located on both sides of the heat point. Subsequent heat-treating does not completely cure the stressed and weakened area. Additionally, in the current industry, the joining of the components to the drill steel generally requires manual labor to assemble the parts. This assembly process results in variability in alignment of the component parts to the drill sections, and thus in the alignment of one drill steel member, such as a driver, when joined to another drill steel member, such as a finisher.
[0013] As one skilled in the art will appreciate, the potential for misalignment as well as the production of stress fractures and cracks around the transfer point can lead to a premature failure of one or more of the drill steel members and thus result in unsafe working conditions. Once the drill member is inserted well within the depths of the drilling hole, the opportunity for lateral movement of the drill steel member within the hole is minimal. Since the drilling machine is stationary, any stresses or forces generated by misalignment of the drill steel members will be imparted on the weakest point of the drilling system, e.g., the existing stress fracture or crack or misaligned area, and thus the drill steel member will prematurely fail. Such a fracture gives rise to several problems.
[0014] The first of these is the great potential of injury to the miners operating the equipment or in the vicinity of the failure. Often fracture occurs in the area proximate the drive end of the drilling machine and near the drilling machine operator, an extremely hazardous and unsafe condition. The situation at the time of such a fracture may involve several lengths of hollow steel rods, perhaps 10 feet, or more, in length, extending vertically and pressed upwardly while being subjected to rotating forces and upward pressure. Consequently, a fracture of one section could cause a number of flying steel projectiles capable of causing injury.
[0015] Because such fractures are relatively common, to reduce the costs associated with this operation it has been the practice to repair the drill steel after it has fractured. This is done by cutting the steel to provide a clean smooth end and welding a new socket or flat surface shank on the now shortened length of drill steel. Apart from the time required for and expense of this process, the problem of the stressed portion following the now welded piece is created again because of the heat required for the welding operation and the possibility of new fractures, with all of the previous problems, still exists.
[0016] Another problem is the cost of time and energy to repair or replace the fractured piece in order that work may continue. Therefore, as one skilled in the art will appreciate, these problems result in higher production costs due to excessive component usage and equipment downtime.
[0017] Still a third problem is the uncertainty as to when the fracture will occur. This uncertainty exists because such failure may occur in a relatively short time after the drill steel is put into use or it may occur at any time and, therefore, all precautions taken for safety or other reasons must be available at all times.
[0018] As pointed out above, varying lengths of the hollow pieces of drill steel are connected one to the other to provide the necessary driving connection between the drill chuck and the drill bit. The bit cuttings and collected dust are drawn through the lengths of drill steel passing from one to the other until they are deposited in a collector. In the prior art where these lengths are connected to one another or other couplers, adapters, sockets or shanks, the ends of the various pieces are formed with flat surfaces. It is possible to have a build up of the collected material at these flat surfaces causing a narrowing flow area and perhaps causing a total stoppage of flow decreasing the efficiency of the system. This too can lead to a halt in the work, adding to the costs of operation.
[0019] After a hole has been drilled, the drill steel, as described herein, is removed, and a bolt is placed in the hole. Resin is then shot into the hole and the bolt is spun at a high rate until the resin is set, securing the bolt in the hole. The bolt is spun using a special purpose drill steel that incorporates an embodiment of this invention engaged at one end in the chuck of a rotating tool.
[0020] Thus, there has been a long felt need for an improved drill steel member that provides a longer product life and a significant reduction in premature failures during operation. Furthermore, there exists a long felt need for drill steel members that are not only safer for the mineworker and for the industry but also provide improved drilling performance.
SUMMARY OF THE INVENTION
[0021] The present invention provides a family of drill steels for various purposes, including starters, drivers, finishers, and special purpose drill steels for turning roof bolts. The drill steel members disclosed herein do not utilize heat to join or configure component parts to the various sections.
[0022] It is, therefore, an object of the present invention to provide a strong, durable drill steel that avoids the disadvantages of the prior art.
[0023] It is another object of the present invention to provide a novel process for the manufacture of drill steels that does not result in a diminished strength area anywhere along the length of such an article. A related object of the present invention is to enable a drill steel that does not utilize heat to join or configure component parts to the ends of the drill steel sections.
[0024] It is another object of this invention to provide a novel drill steel capable of being used for extended periods with less concern for failure than heretofore possible.
[0025] A still further object of this invention is to provide a novel drill steel wherein the possibility of stoppage of flowing material within the steel is reduced.
[0026] In accordance with the above objects, a family of drill steels is disclosed which enables strong and durable drill steels manufactured by machining the ends of the drill steel, without the use of forging or welding. The drill steel comprises an elongate body having a uniform outer diameter with a generally hollow configuration and having each end of such body adapted for attaching additional components thereto, such ends being machined to a smaller outer diameter.
[0027] The foregoing and other objects of the invention are achieved by removing metal from the exterior or interior, as the case may be, of the hollow drill steel to form the required flat coupling or engaging surfaces. In a preferred embodiment, this is accomplished by machining the surfaces.
[0028] The various features of novelty that characterize the invention will be pointed out with particularity in the claims of this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The above and other features, aspects, and advantages of the present invention are considered in more detail, in relation to the following description of embodiments thereof shown in the accompanying drawings, in which:
[0030] [0030]FIG. 1 is a side view partially in section illustrating one embodiment of the invention;
[0031] [0031]FIGS. 2 and 3 are end views along the lines 2 - 2 and 3 - 3 respectively of FIG. 1;
[0032] [0032]FIG. 4 is an exploded side view of another embodiment of the invention;
[0033] [0033]FIG. 5 is an end view along the line 5 - 5 of FIG. 4;
[0034] [0034]FIG. 6 is a partial side view of the end of a length of drill steel according the prior art;
[0035] [0035]FIG. 7 is a partial side view of the end of a length of drill steel in accordance with this invention;
[0036] [0036]FIG. 8 is an exploded view of one form of a special purpose drill steel embodying the invention; and
[0037] [0037]FIG. 9 is an exploded view of another form of a special purpose drill steel embodying the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0038] The invention summarized above and defined by the enumerated claims may be better understood by referring to the following description, which should be read in conjunction with the accompanying drawings in which like reference numbers are used for like parts. This description of an embodiment, set out below to enable one to build and use an implementation of the invention, is not intended to limit the enumerated claims, but to serve as a particular example thereof. Those skilled in the art should appreciate that they may readily use the conception and specific embodiment disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent assemblies do not depart from the spirit and scope of the invention in its broadest form.
[0039] Referring first to FIG. 1, reference numeral 2 designates generally a length of drill steel in the form of a tube having a hollow passage 4 . Formed at one end is a first portion 6 having a hexagonal end. Such a hexagonal end is customarily used to engage a drill bit and may be provided with a hole 7 to engage a retaining clip. Formed at the other end is a second portion 8 having a hexagonal surface.
[0040] It should be understood, the shape of the flat surfaces on the ends of the drill steel is determined by the shape of the element with which it is to be connected, and therefore is typically shaped as a polygon, that is, square or hexagonal, as required. Thus, the coupling element may be a socket for engaging another drill steel, a socket for engaging a roof bolt, a drill chuck, or a drill bit. In addition, the coupling element may be a collar or a shank permitting coupling to another member. Likewise, whether the flat surface is internal or external depends upon the same considerations. The various connectors, collars and such are provided with surfaces matching the end of the drill steel they are to engage and can be mounted on the steel using press fits.
[0041] [0041]FIGS. 2 and 3 illustrate the cross section of a drill steel section along the lines 2 - 2 and 3 - 3 respectively of FIG. 1.
[0042] [0042]FIG. 4 illustrates one embodiment of the invention. In this figure, the drill steel 9 has an external hexagonal surface 10 at one end for engaging a female connector 12 having an internal hexagonal surface 11 to attach another drill steel. See FIG. 5, which is a sectional view along the lines 5 - 5 of FIG. 4. Formed at the other end of drill steel 9 is a hexagonal external end 14 that may, when in use, engage in complementary tube 16 having a matching hexagonal internal surface that may be press fitted on the end 14 along with a collar 18 .
[0043] As stated above, in the prior art the engaging square or hexagonal surfaces are formed by forging. In the forging process, the portion of the drill steel to be forged is heated to very high temperatures, approximately 1700 degrees F. and essentially beaten to the desired shape. This process results in a stressed and weakened portion in areas adjacent to the forged portion, such as indicated by the bracket 20 in FIG. 1.
[0044] The present invention involves forming the flat surfaces by machining, that is, the necessary metal is removed from the drill steel, which consequently is not distorted by a forging process. This process is carried out using conventional machine tools such as a vertical mill. For example, hexagonal surfaces 10 and 14 are machined on drill steel 9 . The drill steels themselves are heat treated either prior or subsequent to the machining process. It should be understood that the temperatures used to heat treat are not the same magnitude as those used to render the steels malleable for forging.
[0045] As a result of this process, the drill steel is not weakened in any respect that we have been able to determine. Consequently, the possibility of fracture caused by a stressed section is lessened, if not eliminated entirely.
[0046] The resulting advantage to the industry and the miner has been pointed out above.
[0047] Reference is made to FIGS. 6 and 7 of the drawings for a description of another advantageous aspect of the invention. FIG. 6 illustrates a drill steel 22 in accordance with the prior art. Drill steel 22 is shown broken to indicate it may be of any length. It is provided with two ends 24 and 26 having flat surfaces, each shown in cross section. The end 24 is formed as a square internal surface while the end 26 is formed as a hexagonal surface. In the prior art the respective faces 28 and 30 of each of these flat surfaces are at right angles to their lengthwise extensions. Thus, as material from the drill bit flows through the drill steel when in operation such material may collect around the flat surfaces, such as faces 28 and 30 . The build up of such material can result in blockage or narrowing of the passage thereby decreasing the efficiency of the process.
[0048] By machining the flat surfaces in accordance with the invention, the ends or faces can be chamfered or sloped as shown at 32 and 34 in FIG. 7. In this figure, the drill steel 36 is shown as having an exterior hexagonal surface 38 and an interior square surface 40 . As the result of this construction, no sharp ledges or faces, such as shown at 28 and 30 in FIG. 6, are presented to obstruct the flow of materials.
[0049] As stated above, the invention may be used to make drill steels to secure bolts in the holes formed by drilling using drill steels incorporating the invention. Such drill steels also are made by machining or otherwise removing metal from the surfaces of steel or alloy pieces.
[0050] Thus, in FIG. 8, drill steel 49 comprises a head 50 having a hexagonal or square recess on one end forming a socket to engage a roof bolt. The other end of head 50 is formed with an extension having a machined interior surface 52 , having a uniform interior diameter. A body 54 is likewise formed from an elongate tube with machined surfaces on two male ends of body 54 . At a first male end, machined surface 56 is shaped to match interior surface 52 . Machined surface 56 has a uniform outer diameter that is slightly larger than the inner diameter of machined interior surface 52 . Body 54 is connected to head 50 by matching the first male end shaped machined surface 56 with the shaped interior surface 52 and press fitting the components together. At the second male end of body 54 , machined surface 58 is shaped having a uniform outer diameter that is smaller than the outer diameter of body 54 . The shape of machined surface 58 may be hexagonal or square in order to engage the drive chuck of the roof-drilling machine or other drill. As may be seen, in accordance with current practice machined surface 58 is generally longer than machined surface 56 to facilitate coupling to a drill chuck. Drill steel 49 further comprises a collar 60 having an aperture therethrough, shaped to match machined surface 58 . The inner diameter of such aperture is slightly smaller than the uniform outer diameter of machined surface 58 . Collar 60 is press-fit onto machined surface 58 until collar 60 engages shoulder 61 . Shoulder 61 is formed on body 54 during machining of machined surface 58 since the outer diameter of machined surface 58 is smaller than the outer diameter of body 54 . Collar 60 limits the insertion of machined surface 58 into the drill chuck. The drill steel thus formed uses no forging or welding with attendant weakened zones.
[0051] In FIG. 9, an alternate embodiment of a drill steel is provided. Drill steel 62 comprises a head 63 having a first recess forming a socket to engage a roof bolt, a body 64 having a generally uniform exterior diameter with two male end machined surfaces 66 and 68 , and a chuck-engaging piece 70 with surfaces machined to engage the body 64 and the drill chuck.
[0052] Head 63 further comprises an extension having a second machined recess, having a uniform interior diameter. Machined surface 66 is configured to match such second machined recess in head 63 . Machined surface 66 has a uniform outer diameter that is smaller than the exterior diameter of body 64 and slightly larger than the inner diameter of the second machined recess in head 63 . In a preferred embodiment, the socket in head 63 is configured to engage a square roof bolt; both recesses in head 63 and machined surface 66 are also shaped as a square in cross-section. Body 64 is connected to head 63 by matching the shaped machined surface 66 with the second shaped machined recess and press fitting the components together.
[0053] Body 64 further comprises machined surface 68 having a uniform exterior diameter slightly smaller than body 64 . The shape of machined surface 68 may be configured as hexagonal or square in cross-section in order to be connected to chuck engaging piece 70 . Chuck engaging piece 70 comprises a machined recess configured in the same shape as machined surface 68 . Chuck engaging piece 70 is press-fit onto machined surface 68 . The exterior surface of engaging piece 70 is machined to an appropriate shape, such as square or hexagonal, to engage a drill chuck. A chuck insertion limiting shoulder 72 is machined into the structure of engaging piece 70 . Shoulder 72 is designed to limit the depth to which drill steel 62 can be inserted into the drill chuck. After machining, these parts are pressed onto each other to complete drill steel 62 . Again, there are no forged or welded parts.
[0054] It should be understood that the process of machining drill steel can be used on any such devices whether it be a starter, a pusher, a finisher, or a driver. Likewise the process can be used on the chucks, adaptors, shanks, couplings and the like, that are formed with square or hexagonal surfaces used with drill steels.
[0055] The invention has been described with references to a preferred embodiment. While specific values, relationships, materials and steps for various embodiments have been set forth for purposes of describing concepts of the invention, it will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the basic concepts and operating principles of the invention as broadly described. It should be recognized that, in the light of the above teachings, those skilled in the art can modify those specifics without departing from the invention taught herein. Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is contemplated to include all such embodiments, alternatives and other modifications insofar as they come within the scope of the claims appended hereto or equivalents thereof. It should be understood, therefore, that the invention may be practiced otherwise than as specifically set forth herein. Consequently, the present embodiments are to be considered in all respects as illustrative and not restrictive.
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A drill steel for use in mine roof bolting operations. To eliminate or reduce the possibility of fracture in drill steels used in the roof bolting operations in mines the square or hexagonal surfaces of such drill steels or the elements such as couplings, collars, and recesses that are to be connected to drill steels are machined rather than forged or welded. Pieces are joined by press fitting for assembly purposes.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority benefit of Taiwan application serial no. 98111842, filed on Apr. 9, 2009. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of specification.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a packaging process of a light emitting diode (LED), and more particularly to a packaging process of an LED capable of increasing the viscosity of an encapsulant of an LED package rapidly.
2. Description of Related Art
Due to the advantages of long lifetime, compactness, high vibration resistance, low heat emission, and low power consumption, light emitting diodes (LEDs) have been widely applied in indicators or light sources of various home appliances and instruments. With recent development towards multicolor and high illumination, the applications of the LEDs are extended to large-sized outdoor billboards, traffic lights, and the like. In the future, the LEDs may become the power-saving and environment-friendly light sources in replacement of tungsten filament lamps and mercury vapor lamps.
Generally, an LED package includes a carrier, an LED chip, and an encapsulant. The LED chip is disposed on the carrier and electrically connected to the same. The encapsulant encapsulates the LED chip and a portion of the carrier to protect the LED chip and expose a portion of the carrier outside of the encapsulant to provide a function of external electrodes. Since light emitted by the LED chip is transmitted to the outside of the LED package through the encapsulant, the encapsulant of the LED not only has a function of protecting the LED chip, but is also closely related to overall light emitting efficiency and optical characteristic of the LED.
In the conventional packaging process of the LED, the manufacture of the encapsulant is generally categorized into compression molding and transfer molding. In the process of compression molding, a substrate having LED chips mounted thereon is inserted into a mold which contains a melted encapsulant, after the encapsulant has been cured, an entire package is released from the mold to complete the encapsulating process. In the process of transfer molding, a substrate having LED chips mounted thereon is clamped by a mold, and a melted encapsulant is injected into the molding cavity of the mold to encapsulate the LED chip, after the encapsulant has been cured, an entire package is released from the mold to complete the encapsulating process.
However, both the compression molding and the transfer molding require molds and expensive injection machines, which results in a certain manufacturing cost. Moreover, a molding cavity of the mold may be deformed or damaged after being used for a period of time, thereby changing a configuration of the encapsulant formed and further affecting yield rate. In addition, since the making and modifying of the molds both require repetitive developments and adjustments, the molds can not be developed and modified quickly according to different designs. As a result, the production time is likely to be delayed. Hence, how to improve the packaging process is one of the issues that have to be conquered in the manufacture of the LED.
SUMMARY OF THE INVENTION
The present invention provided a packaging process of a light emitting diode (LED). The process rapidly increases a viscosity of an encapsulant formed on a carrier.
As embodied and broadly described herein, a packaging process of an LED is provided is the present invention, and includes the following steps. Firstly, an LED chip is bonded with a carrier to electrically connect the LED chip and the carrier. Next, the carrier is heated to raise a temperature of the carrier. Thereafter, an encapsulant is formed on the heated carrier to encapsulate the LED chip, wherein a viscosity of the encapsulant before contacting the carrier is lower than that of the encapsulant after contacting the carrier. Afterwards, the encapsulant is cured.
In one embodiment of the present invention, the process of forming the encapsulant on the heated carrier is performed by a dispensing process.
In one embodiment of the present invention, a processing temperature of bonding the LED chip with the carrier is T 1 , and a temperature of the heated carrier is T 2 . Moreover, a temperature difference (T 2 −T 1 ) ranges from 70° C. to 180° C.
In one embodiment of the present invention, the processing temperature of bonding the LED chip with the carrier ranges from 25° C. to 30° C. On the other hand, the temperature of the heated carrier ranges from 100° C. to 200° C.
In one embodiment of the present invention, the encapsulant is a transparent encapsulant.
In one embodiment of the present invention, the encapsulant is a thermal-setting encapsulant.
In one embodiment of the present invention, the viscosity of the encapsulant before contacting the carrier ranges from 1500 mPas to 4000 mPas.
In one embodiment of the present invention, the process of curing the encapsulant includes pre-curing the encapsulant and fully curing the encapsulant.
In light of the foregoing, since the present invention allows the rapid increase in the viscosity of the encapsulant formed on the carrier by raising the temperature of the carrier, the encapsulant can be formed more efficiently.
In order to make the aforementioned and other features and advantages of the present invention more comprehensible, several 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.
FIGS. 1A˜1E are cross-sectional diagrams of a packaging process of an LED according to an embodiment of the present invention.
FIGS. 2˜4 are graphs illustrating relationships between heating times and viscosities of different encapsulants under different temperatures.
DESCRIPTION OF EMBODIMENTS
FIGS. 1A˜1E are cross-sectional diagrams of a packaging process of a light emitting diode (LED) according to an embodiment of the present invention. Referring to FIG. 1A , firstly, an LED chip 110 and a carrier 120 are bonded such that the LED chip 110 and the carrier 120 are electrically connected with each other. The carrier 120 can be broadly interpreted as any carrier that is capable of carrying and electrically connecting with the LED chip 110 . In the present embodiment, the carrier 120 is a printed circuit board (PCB), and this printed circuit board is manufactured with ceramic material or plastic material, for example. Moreover, the printed circuit board can also be a metal core printed circuit board (MCPCB) with good heat dissipation characteristic or a flexible printed circuit (FPC). In other words, the manufacture of a light emitting diode 100 in the present embodiment is carried out with a chip-on-board (COB) technique. In details, in the COB technique, the LED chip 110 is directly mounted onto a circuit board, and then the LED chip 110 is electrically connected to the circuit board via bonding wires through a wire-bonding process.
The present invention does not specifically limit the type of the carrier 120 . In another embodiment of the present invention, the carrier 120 is a leadframe including two leads (not shown) for electrically connecting with the LED chip 110 and a die pad (not shown) for carrying the LED chip 110 .
Referring to FIG. 1B , the carrier 120 is then heated to raise a temperature thereof. In the present embodiment, a processing temperature of bonding the LED chip 110 with the carrier 120 is T 1 , and a temperature of the heated carrier 120 is T 2 . Moreover, a temperature difference (T 2 −T 1 ) ranges from 70° C. to 180° C.
Furthermore, in the present embodiment, the processing temperature of bonding the LED chip 110 with the carrier 120 ranges from 25° C. to 30° C. Alternatively, the temperature of the heated carrier 120 ranges from 100° C. to 200° C. Obviously, the present invention does not specifically limit the method of heating the carrier 120 , those skilled in the art may adopt suitable processes and apparatuses to heat the carrier 120 , and the present embodiment does not limit the method of heating the carrier 120 .
Next, referring to FIGS. 1C˜1E , after the carrier 120 has been heated to raise the temperature thereof, a dispensing process, for example, is performed with a dispenser 140 to dispense an encapsulant 130 on the heated carrier 120 for encapsulating the LED chip 110 , as illustrated in FIG. 1E .
Specifically, the encapsulant 130 is generally manufactured with materials having high transmittance, so that the light emitted from the LED chip 110 can penetrate the encapsulant 130 and transmits outside of the LED 100 .
Moreover, in the present embodiment, the encapsulant 130 is a thermal-setting encapsulant having specific physical or chemical characteristic required by the manufacturing process. For example, the material of the encapsulant 130 is epoxy, polymethyl methacrylate (PMMA), polycarbonate (PC), acrylate, or other optical polymer materials. Similarly, the present invention does not specifically limit the material of the encapsulant 130 . For example, the encapsulant 130 may also include nano-particles doped therein. In this case, the light emitted from the LED chip 110 is scattered by the nano-particles such that the light of the LED 100 is more uniform and the intensity of the light emitted by the LED 100 is enhanced.
As aforementioned, in the process of heating the carrier 120 and forming the encapsulant 130 by the dispensing process, the carrier 120 is heated to a specific temperature and the viscosity of the encapsulant 130 changes rapidly after the carrier 120 contacts the encapsulant 130 . When the encapsulant 130 contacts the carrier 120 , the encapsulant 130 is indirectly heated due to thermal conduction, so that the viscosity of the encapsulant 130 after contacting the carrier 120 increases rapidly.
Next, a curing process is performed to the encapsulant 130 . In the present embodiment, a process of curing the encapsulant 130 includes pre-curing the encapsulant 130 . More specifically, the pre-curing is carried out at a certain processing temperature, so that the encapsulant 130 is partially cured. In the present embodiment, the temperature of pre-curing ranges from 100° C. to 200° C. Next, the encapsulant 130 is fully cured. For example, the process of curing the encapsulant 130 can be a thermal curing process. In the present embodiment, a temperature of fully curing is approximately 150° C. and a time thereof is approximately 1˜2 hours. It should be illustrated that the processing temperatures applied in the pre-curing and the fully curing are generally similar. The difference between the pre-curing and the fully curing is the lengths of the curing time.
Referring to the following experiments, it should be noted that if the carrier 120 is heated before the encapsulant 130 is dispensed on the carrier 120 , a positive effect is observed for the increase in the viscosity of the encapsulant 130 which is formed on the carrier 120 .
FIGS. 2˜4 are graphs illustrating relationships between heating times and viscosities of different encapsulants under different temperatures. Referring to FIG. 2 , X-axis denotes the heating time while Y-axis denotes the viscosity of the encapsulant (mPas). In the present embodiment, when the thermal-setting encapsulant is heated from about room temperature and the temperature is set as 25° C. or 40° C. after heating, the viscosity of the thermal-setting encapsulant is substantially unchanged in the 120 minutes of heating time, and the slope of the curve is slightly higher than zero in general.
On the other hand, when the temperature of the thermal-setting encapsulant is 60° C. after the heating, the viscosity of the encapsulant and the rate of increasing viscosity are both dramatically increased starting at the 40 th minute of heating. From FIG. 2 , it is obvious that the slope of the curve is also rapid increased from the 40 th minute of heating. Specifically, the viscosity rapidly increases at a rate as rapid as at least 3500 mPas in 70 minutes after the 40 th minute.
When the temperature of the thermal-setting encapsulant is 80° C. or 100° C. after heating, a similar phenomenon occurs. However, the difference between the two is that the time points showing the rapid increasing of the slope after the heating are 15 minutes and 3 minutes, respectively. That is, after been heated for about 15 minutes and 3 minutes, the thermal-setting encapsulant starts to melt and the viscosity thereof increases rapidly. It should be illustrated that in the beginning of the heating process, the raise in the temperature causes the viscosity of the encapsulant to decrease temporarily, but the viscosity increases rapidly later on. This phenomenon does not affect the purpose of rapidly molding the encapsulant in the present invention.
Referring to FIG. 3 , the graph showing the relationship between the heating time and the viscosity of the encapsulant is similar to that of FIG. 2 . However, the difference between the two is that the type of encapsulant, the temperature, and the heating time in FIG. 3 is different from those illustrated in FIG. 2 . In the present embodiment, when the temperature of the thermal-setting encapsulant is 25° C. or 40° C. after heating, the viscosity of the encapsulant generally changes slowly within the heating time of 480 minutes. The viscosities are respectively 2400 mPas˜3100 mPas and 2400 mPas˜3400 mPas.
When the temperature of the thermal-setting encapsulant is 60° C. after heating, the viscosity thereof and the rate of increasing viscosity are both dramatically increased. When the temperature is 80° C. after heating, the viscosity thereof and the rate of increasing viscosity are increased rapidly after about 20 minutes of heating.
Referring to FIG. 4 , the graph showing the relationship between the heating time and the viscosity of the thermal-setting encapsulant is similar to that of FIG. 2 . However, the difference between the two is that the type of encapsulant, the temperature, and the heating time in FIG. 4 is different from those illustrated in FIG. 2 . In the present embodiment, when the temperature of the thermal-setting encapsulant is 60° C. after heating, the viscosity thereof is substantially 3500 mPas to 5900 mPas within the 30 minutes of heating time. When the temperature is respectively 80° C., 100° C., and 150° C., the viscosities of the thermal-setting encapsulant are increased rapidly after about 7 minutes, 5 minutes, and 4 minutes of heating.
After the encapsulant contacts the heated carrier, the raise in temperature causes the viscosity of the encapsulant to decrease temporarily and increase rapidly later on. Moreover, the faster the raising of the temperature, the faster the rate of increasing the viscosity of the encapsulant; therefore, the encapsulant having predetermined height and shape can be formed rapidly. In practical implementation, the heights and shapes of different encapsulants are obtained by adjusting the heating temperature, the rate of dispensing and choosing encapsulants having different viscosity characteristics.
In the present invention, the encapsulant is heated to a certain temperature so as to increase the viscosity of the encapsulant rapidly. The encapsulant can be rapidly molded by controlling the amount of dispensed encapsulant and the rate of dispensing the encapsulant.
In light of the foregoing, the present invention rapidly enhances the viscosity of the encapsulant formed on the carrier by raising the temperature of the carrier, thereby the encapsulant can be formed more rapidly. In comparison to the conventional packaging process, the packaging process of the LED in the present invention reduces the manufacturing cost of molding process, simplifies the overall manufacturing process, reduces the manufacturing time, and has a high flexibility of modifying the process.
Although the present invention has been described with reference to the above embodiments, it will be apparent to one of the ordinary skill in the art that modifications to the described embodiment may be made without departing from the spirit of the invention. Accordingly, the scope of the invention will be defined by the attached claims not by the above detailed descriptions.
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A packaging process of a light emitting diode (LED) is provided. First, an LED chip is bonded with a carrier to electrically connect to each other. After that, the carrier is heated to raise the temperature thereof. Next, an encapsulant is formed on the heated carrier by a dispensing process to encapsulate the LED chip, wherein the viscosity of the encapsulant before contacting the carrier is lower than that of the encapsulant after contacting the carrier. Thereafter, the encapsulant is cured.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an aluminum alloy material with superior corrosion resistance, and to a plate heat exchanger using the aluminum alloy material in or as a heat transfer unit that uses a corrosive fluid, such as seawater, as a coolant (cooling medium).
[0003] 2. Description of the Related Art
[0004] Aluminum (Al) alloys have high specific strength and high thermal conductivity and thus have been widely used as materials for compact lightweight heat exchangers. Representative examples of heat exchangers composed of aluminum alloys include fin-and-tube heat exchangers for use in household air conditioners and automotive radiators. In contrast, most of industrial single-pass heat exchangers using seawater as coolants are composed of titanium (Ti). Attempts have been made, however, to apply more economical aluminum alloys to such industrial single-pass heat exchangers.
[0005] Exemplary single-pass heat exchanges including heat transfer units using seawater as coolants (cooling water) include plate heat exchangers. They are exposed to stringent corrosive environments upon use in seawater environments. Thus, titanium (Ti), which has excellent corrosion resistance, is currently used. Aluminum alloys have high corrosion resistance as materials. However, when aluminum alloys are used for such plate heat exchangers in place of titanium, further sufficient corrosion protection is required, because they have not so high corrosion resistance as compared to titanium.
[0006] In general, examples of corrosion protection of aluminum alloys constituting such plate heat exchangers include formation of anodic oxide coatings, electrolytic protection, and formation of coatings with paint. Corrosion protection measures, if applied to heat exchangers, further include the incorporation of an inhibitor into a coolant.
[0007] However, plate heat exchangers are of a single-pass type, meaning that a coolant is discharged to outside of a system after passing through the apparatus and is not reused by circulation. Thus, a corrosion protection measure using an inhibitor is not proper, but a corrosion protection measure using paint film formation is economically appropriate.
[0008] Examples of coatings usable for aluminum alloys constituting heat exchangers include various types of inorganic, organic, and organic-inorganic hybrid coatings. These coatings are now practically used. Methods of forming coatings for heat exchangers are described typically in Japanese Unexamined Patent Application Publication (JP-A) No. 2003-88748 (Patent Document 1), JP-A No. 2004-42482 (Patent Document 2), JP-A No. 2006-169561 (Patent Document 3), and Akihiro YABUKI, Hiroyoshi YAMAGAMI, Takeshi OWAKI, Kiyomi ADACHI, and Koji NOISSHIKI, “Self-Repairing Property of Anticorrosive Coating for Aluminum Alloy”, Conference Proceedings of Material and Environment, 3-4 (2004) (Non-patent Document 1).
[0009] Patent Document 1 discloses the formation of a polyaniline coating for an aluminum alloy not constituting a plate heat exchanger using seawater as a coolant, to which the present invention is directed, but constituting a fin-and-tube heat exchanger for use typically in household air conditioners and automotive radiators.
[0010] Patent Document 2 discloses that, to improve adhesion, a coating is formed on a composite primer coating for an aluminum alloy material constituting a fin-and-tube heat exchanger for use in household air conditioners and automotive radiators as in Patent Document 1, which composite primer coating includes a coating prepared through treatment with a boehmite and/or a silicate.
[0011] Non-patent Document 1 discloses an anticorrosive trifluoroethylene polymer coating for a single-pass heat exchanger, which coating has self-repairing properties.
[0012] Patent Document 3 proposes a self-repairing aluminum alloy anticorrosive coating further containing 0.1 to 10 percent by volume of one or more members selected from zinc, titanium, manganese, aluminum, and niobium, in addition to such trifluoroethylene polymer. This technique is indicated as an improvement of the trifluoroethylene polymer anticorrosive coating. This is a measure for the fact that with a heat exchanger using seawater as a coolant, the surface of the heat exchanger is liable to be damaged, and, when surface damage is once induced, the damage tends to be abruptly enlarged by a vigorous corrosive action with seawater. More specifically, it is stated that the trifluoroethylene polymer anticorrosive coating containing a powder of the above-mentioned metal exhibits self-repair capability when the coating suffers damage.
[0013] The polyaniline coating disclosed in Patent Document 1 may be sufficient for an improvement in corrosion resistance of fin-and-tube heat exchangers used for household air conditioners and automotive radiators. However, when used in plate heat exchangers using seawater as coolants, to which the present invention is directed, such a coating is unsatisfactory with respect to seawater corrosion resistant properties such as corrosion resistance and coating adhesion in a saline environment such as of seawater.
[0014] The anticorrosive trifluoroethylene polymer coatings (fluorocarbon resin coatings) disclosed in Patent Document 3 and Non-Patent Document 1 have superior seawater corrosion resistance compared to the polyaniline coating disclosed in Patent Document 1 and to common corrosion protection such as anodic oxidation coatings and other coatings. However, when applied to a plate heat exchanger using seawater as a coolant, to which the present invention is directed, there arises a problem in that they degrade in adhesion (adhesion durability) to aluminium alloy materials in long-term use and are not thus reliable.
[0015] The degradation of adhesion (i.e., coating durability) to aluminium alloy materials in long use occurs likewise in primer or primer treatment that is directed to heat exchangers used in domestic air conditioners and automotive radiators such as of Patent Document 2. However, the fin-and-tube heat exchangers used in the air conditioners and automotive radiators have the life of at most ten and several years, and a required life of corrosion resistance is such a relatively short time as just mentioned.
[0016] In this connection, however, plate heat exchangers using seawater as coolants, such as vaporizers for natural liquefied gas, are industrially employed in plants, are of large-scale equipment and thus expensive. Accordingly, it is required that the life and anticorrosive life of the heat exchangers be a semipermanent life of several tens of years.
[0017] The corrosion resistance of such long life-oriented plate heat exchangers using seawater as coolants is predominant of adhesion of a coating to an aluminium alloy material rather than the corrosion resistance of the coating itself.
[0018] In this regard, the anticorrosive technique of providing a trifluoride resin anticorrosive coating (fluorocarbon resin coating) directly on a surface of aluminium alloy material as in Patent Document 3 and Non-patent Document 1 has a practical problem in that an adhesion to the aluminium alloy material is poor, and it is difficult to substantially improve the corrosion resistance under use of seawater.
SUMMARY OF THE INVENTION
[0019] Under these circumstances, an object of the present invention is to provide an aluminium alloy material having superior adhesion of a trifluoride resin anticorrosive coating, i.e. an aluminium alloy material having superior corrosion resistance. Another object of the present invention is to provide a plate heat exchanger with superior corrosion resistance.
[0020] Specifically, according to an embodiment of the present invention, there is provided an aluminum alloy material with superior corrosion resistance, which includes an aluminum alloy base material (base metal or substrate), an organic phosphonic acid primer coating arranged on the surface of the aluminum alloy base material, and a fluorocarbon resin coating arranged on the surface of the organic phosphonic acid primer coating, in which the aluminum alloy base material has an anodic oxide layer as its surface layer, the anodic oxide layer has an average thickness of from 1 to 20 μm, and the fluorocarbon resin coating has an average thickness of from 1 to 100 μm after drying.
[0021] The fluorocarbon resin coating preferably contains a trifluoroethylene polymer as its base polymer.
[0022] The trifluoroethylene polymer is preferably a chlorotrifluoroethylene/vinyl ether copolymer, and the fluorocarbon resin coating is preferably a crosslinked product of the chlorotrifluoroethylene/vinyl ether copolymer with an isocyanate.
[0023] The fluorocarbon resin coating preferably contains substantially no metal powder.
[0024] The organic phosphonic acid primer coating may contain at least one organic phosphonic acid selected from methylphosphonic acid, ethylphosphonic acid, and vinylphosphonic acid.
[0025] The aluminum alloy material is preferably used in a plate heat exchanger that uses a corrosive fluid as a coolant.
[0026] According to another embodiment of the present invention, there is provided a plate heat exchanger with superior corrosion resistance, which includes the aluminum alloy material in or as a heat transfer unit that uses a corrosive fluid as a coolant.
[0027] According to the present invention, there can be provided an aluminum alloy material having superior adhesion of a fluorocarbon resin coating and thus preventing the coating from peeling off. There can also be provided a plate heat exchanger with superior corrosion resistance, using the aluminum alloy material in or as a heat transfer unit that uses seawater as a cooling water (coolant).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The present invention will be illustrated in detail with reference to some embodiments below. All numbers are herein assumed to be modified by the term “about.”
[0029] Fluorocarbon Resin Coating
[0030] The thickness (average thickness) of the fluorocarbon resin coating is from 1 to 100 μm. A fluorocarbon resin coating, if having an average thickness of less than 1 μm, may show insufficient corrosion resistance. In contrast, a fluorocarbon resin coating, if having an average thickness of more than 100 μm, may impede the high thermal conductivity of aluminum to thereby impair the heat exchange capability of the heat exchanger and may show reduced adhesion, i.e., insufficient corrosion resistance contrarily. Accordingly, the average thickness of the fluorocarbon resin coating should be within the range of from 1 to 100 μm.
[0031] The average thickness of the fluorocarbon resin coating is determined in the following manner. A sample fluorocarbon resin coating is formed on an aluminum alloy base material through the interposition of an organic phosphonic acid primer coating mentioned below, and sufficiently dried. The cross sections of appropriate ten points of the sample coating are observed with an optical microscope at a magnification of about 50 times to measure thicknesses, and the ten measurements are averaged.
[0032] The fluorocarbon resin coating for use in the present invention preferably contains substantially no metal (metallic powder) such as zinc, titanium, manganese, aluminum, or niobium as described in Patent Document 3. A fluorocarbon resin coating, if containing any metal (metallic powder), may deteriorate in adhesion, because the metal will be oxidized to form an oxide in the coating.
[0033] Fluorocarbon Resins
[0034] Exemplary fluorocarbon resins for use in the fluorocarbon resin paint (coating) include trifluoroethylene polymers and tetrafluoroethylene polymers. Of these fluorocarbon resins, preferred are trifluoroethylene polymers because of higher adhesion to the organic phosphonic acid primer coating and higher corrosion resistance. The trifluoroethylene polymers are also preferred from the standpoint that they are soluble in low polar solvents having relatively low odor, and easy in handling (with good workability). The trifluoroethylene polymers and tetrafluoroethylene polymers may contain monomeric molecules and/or oligomeric molecules.
[0035] Trifluoroethylene, in which three of four hydrogen (H) atoms in an ethylene molecule are substituted by fluorine (F) atoms, is copolymerized with a copolymerizable compound (comonomer) such as a vinyl ether, an acrylic compound, and/or a vinyl ester, to form monomeric and oligomeric molecules of trifluoroethylene polymer. Tetrafluoroethylene, in which all four hydrogen (H) atoms in an ethylene molecule are substituted by fluorine (F) atoms, is copolymerized with a copolymerizable compound such as a vinyl ether, an acrylic compound, and/or a vinyl ester, to form monomeric and oligomeric molecules of tetrafluoroethylene polymer.
[0036] Exemplary trifluoroethylene polymers include chlorotrifluoroethylene (CTFE)/vinyl ether copolymers and chlorotrifluoroethylene/acrylic copolymers.
[0037] Fluorocarbon Resin Paint
[0038] A fluorocarbon resin paint for use in the present invention may be prepared by crosslinking these monomeric and/or oligomeric molecules of trifluoroethylene polymer with isocyanate groups (—N═C═O) of an isocyanate compound and/or siloxane groups of a siloxane compound serving as a curing agent.
[0039] In the present invention, a fluorocarbon resin paint prepared by crosslinking a chlorotrifluoroethylene/vinyl ether copolymer with a curing agent, such as an isocyanate or siloxane compound, is preferred because of the highest adhesion to the organic phosphonic acid primer coating.
[0040] The fluorocarbon resin paint as a coating composition is prepared by adding the curing agent, such as an isocyanate or siloxane compound, to the monomeric and oligomeric molecules of trifluoroethylene polymer as a base polymer. For example, 10 to 15 parts by mass of the base polymer is mixed with 0.1 to 3 parts by mass of the curing agent. The mixture is diluted with a thinner, according to necessity, to form the coating composition.
[0041] Organic Phosphonic Acid Primer Coating
[0042] In the present invention, the primer coating of an organic phosphonic acid, a kind of phosphorus-containing acid, for the fluorocarbon resin paint is selected as a primer coating (treatment), in order to improve the adhesion of the fluorocarbon resin coating (anticorrosive coating) to the aluminum alloy base material so as to improve corrosion resistance during use in seawater.
[0043] It should be noted that, in spite of being phosphorus-containing acids as with organic phosphonic acids, phosphoric acids, including inorganic phosphoric acids and organic phosphoric acids such as phosphates (e.g., zinc phosphate), as well as common primer treatments, such as chromate treatment and boehmite treatment, do not have the practical effect of improving adhesion of a fluorocarbon resin coating (anticorrosive coating) to the aluminum alloy base material. Thus, these are not employed herein.
[0044] Organic phosphonic acids are unsubstituted compounds each having two hydroxyl groups bonded to the phosphorus atom. Exemplary organic phosphonic acids include methylphosphonic acid: CH 3 P(═O) (OH) 2 , ethylphosphonic acid: C 2 H 5 P(═O) (OH) 2 , vinylphosphonic acid: C 2 H 3 P(═O) (OH) 2 , octylphosphonic acid: C 8 H 17 P(═O) (OH) 2 , and phenylphosphonic acid: C 6 H 5 P(═O) (OH) 2 .
[0045] From the viewpoint of handleability and superior adhesion-improving effect, the organic phosphonic acid primer coating is preferably composed of at least one organic phosphonic acid selected from methylphosphonic acid, ethylphosphonic acid, and vinylphosphonic acid.
[0046] Organic phosphonic acid has two hydroxyl (OH) groups, as described above. The two OH groups respectively bind to aluminum (Al) and oxygen (O) of the after-mentioned anodic oxide film (Al 2 O 3 ) on the surface of the aluminum alloy base material. The bond is a covalent bond and is very strong compared with other bonds such as ionic bond, van der Waals bond, and hydrogen bond. The hydrocarbon component and C—O component of the fluorocarbon resin are covalently bonded to the organic component of the organic phosphonic acid during crosslinking with the curing agent, forming very strong bonds. The fluorocarbon resin coating applied is therefore strongly bonded to the anodic oxide layer of the aluminum alloy base material through the organic phosphonic acid primer coating, thus significantly improving coating adhesion.
[0047] The way to form the organic phosphonic acid primer coating is not particularly limited. In view that the uniformity of the primer coating affects coating adhesion, the organic phosphonic acid primer coating is preferably prepared by immersing the aluminum alloy base material in an aqueous solution of organic phosphonic acid rather than by other procedures such as directly applying such a coating solution to the surface of the aluminum alloy base material.
[0048] The thickness of the organic phosphonic acid primer coating is not particularly specified. It is difficult and unnecessary to form the organic phosphonic acid primer coating having a thickness of the order of micrometers by the process for forming a primer coating. By employing the known process for forming a primer coating, the primer coating has a thickness of at most several angstroms to several tens of angstroms, which thickness is sufficient to improve the adhesion.
[0049] Uniformity in the thickness of the primer coating is important rather than the thickness of the organic phosphonic acid primer coating. From this viewpoint, the organic phosphonic acid primer coating is preferably prepared by immersing the aluminum alloy base material in an aqueous solution of organic phosphonic acid. The immersion in the aqueous solution of organic phosphonic acid is more preferably performed under conditions described below: the concentration of the organic phosphonic acid is in the range of from 0.01 to 100 g/L, the temperature of the aqueous solution is in the range of from 50° C. to 100° C., and the immersion time (duration) is in the range of from 1 to 120 seconds.
[0050] In the case of an excessively low organic phosphonic acid concentration of less than 0.01 g/L, an excessively low temperature of the aqueous solution of lower than 50° C., and an excessively short immersion time of less than 1 second, the thickness of the primer coating may become nonuniform, thereby increasing the possibility of reduction in coating adhesion. In the case of an excessively high organic phosphonic acid concentration of more than 100 g/L, an excessively high temperature of the aqueous solution of higher than 100° C., and an excessively long immersion time of more than 120 seconds, the thickness of the primer coating may become nonuniform, thereby increasing the possibility of reduction in coating adhesion. Thus, the formation of the organic phosphonic acid primer coating is preferably performed by immersion of the aluminum alloy base material in the aqueous solution of organic phosphonic acid under the conditions described above.
[0051] Anodic Oxidation
[0052] The surface of the aluminum alloy base material is subjected to anodic oxidation in order to form the organic phosphonic acid primer coating and the fluorocarbon resin coating with further satisfactory adhesion. Before carrying out anodic oxidation, the aluminum alloy base material is subjected to ultrasonic cleaning so as to remove, for example, soil on the surface of the aluminum alloy base material.
[0053] In the anodic oxidation, the aluminum alloy base material serving as an anode is immersed in an electrolytic solution and electrolysis is conducted to form an anodic oxide layer as a surface layer of the base material, in which the anodic oxide layer has an average thickness of from 1 to 20 μm. Exemplary usable electrolytic solutions include sulfuric acid, oxalic acid, and a mixture of sulfuric acid and oxalic acid.
[0054] An anodic oxide layer, if having an average thickness of less than 1 μm, may not contribute to a sufficient improvement in adhesion durability of the coating, failing to provide a desired corrosion resistance. In contrast, an anodic oxide layer, if having an average thickness of more than 20 μm, may reduce the heat exchange capability of the heat exchanger to impair the practicability of the heat exchanger, although satisfactory adhesion durability is obtained. Thus, the average thickness of the anodic oxide layer should be within the range of 1 to 20 μm.
[0055] The thickness of the anodic oxide layer can be adjusted by controlling the current, voltage, and duration of the anodic oxidation. Among these parameters, the control of the anodic oxidation duration is effective to adjust the thickness of the anodic oxide layer. Typically, an anodic oxidation for 15 minutes is enough to give an anodic oxide layer having an average thickness of 5 μm. Likewise, an anodic oxidation for 50 minutes is enough to give an anodic oxide layer having an average thickness of 20 μm.
[0056] The average thickness of the anodic oxide layer is determined in the following manner. A sample anodic oxide layer is formed on the aluminum alloy base material, and the cross sections of appropriate ten points of the sample anodic oxide layer is observed with a scanning electron microscope to measure thicknesses, and the ten measurements are averaged.
[0057] Aluminum Alloy Base Material
[0058] Aluminum alloys that can be easily processed or formed into plates may be used. Exemplary types of aluminum alloys usable herein include 1000, 3000, 5000, 6000, and 7000 series aluminum alloys specified in Japanese Industrial Standards (JIS) and Aluminum Association (AA) standards. Plates, strips, and extruded moldings of these aluminum alloys may be appropriately used. Specifically, 3003 and 5052 series aluminum alloys may be suitably used.
[0059] Other Applications
[0060] The present invention has been described with reference to embodiments where the invention is applied to a heat exchanger that uses seawater as a coolant. It should be noted, however, that the present invention can also be applied to any other heat exchangers that use corrosive fluids as coolants. Exemplary corrosive fluids include industrial water containing large amounts of calcium ion and/or magnesium ion; and groundwater containing, for example, hydrogen carbonate ion, chlorine ion, sulfur ion, iron ion, sodium ion, metasilicic acid, and/or hydrogen sulfide.
EXAMPLES
[0061] The present invention will be illustrated in further detail with reference to several examples below. It should be noted, however, that these examples are not intended to limit the scope of the present invention, various alternations and modifications may be made without departing from the scope and spirit of the present invention, and they are included within the technical scope of the present invention.
[0062] In each of Examples according to the present invention, the surface of an aluminum alloy sheet 1.0 mm thick, 60 mm wide, and 60 mm long as a test piece was subjected to anodic oxidation to form an anodic oxide layer on the surface of the test piece. Next, an organic phosphonic acid primer coating was formed on the surface of the anodic oxide layer; and a fluorocarbon resin coating made of a trifluoroethylene polymer was formed on the surface of the organic phosphonic acid primer coating to give a coated aluminum alloy material. The coating adhesion, i.e., the corrosion resistance, of the coated aluminum alloy material was evaluated. The results are shown in Table 1.
[0063] Independently, a coated aluminum alloy material having no anodic oxide layer, and a coated aluminum alloy material having an anodic oxide layer but having no organic phosphonic acid primer coating were prepared as Comparative Examples, and their coating adhesion, i.e., corrosion resistance, was evaluated. In these Comparative Examples, an aluminum alloy sheet 1.0 mm thick, 60 mm wide, and 60 mm long as with Examples was used in the test piece. The results are shown in Table 2.
[0064] Pretreatment
[0065] For the pretreatment, soil, oxides, and hydroxides formed on the surface of the aluminium alloy sheet test piece were once removed to expose the aluminium metal surface. Specifically, while immersing the test piece in acetone, ultrasonic cleaning for 30 seconds was carried out.
[0066] Anodic Oxidation
[0067] Anodic oxidation was conducted by immersing the test piece after the pretreatment in an electrolytic solution and carrying out electrolysis to form an anodic oxide layer having an average thickness of 5 μm or 20 μm on the surface of the test piece. The anodic oxidation was conducted with a diluted sulfuric acid having a concentration of 15 to 18 percent by mass as the electrolytic solution, at a current of from 80 to 100 A/m 2 and a voltage of from 10 to 13 V for a duration of from 15 to 20 minutes. The thickness of the anodic oxide layer was controlled by adjusting the treatment duration. Specifically, an anodic oxide layer 5 μm thick was obtained by anodic oxidation for 15 minutes, and an anodic oxide layer 20 μm thick was obtained by anodic oxidation for 50 minutes. Next, a sealing additive mainly containing nickel acetate was added, and boiling-water sealing was conducted for 15 minutes.
[0068] Primer Treatment with Organic Phosphonic Acid
[0069] Vinylphosphonic acid, used as an organic phosphonic acid, was diluted with ion exchanged water to a concentration of 10 g/liter to provide an aqueous solution of organic phosphonic acid primer. Next, the aluminium alloy sheet test piece after the anodic oxidation was immersed in the aqueous solution of organic phosphonic acid primer, heated at 65° C., for 10 seconds or for 2 minutes (120 seconds) to form an organic phosphonic acid primer coating, followed by rinsing with ion exchanged water.
[0070] Fluorocarbon Resin Coating
[0071] A paint for constituting a fluorocarbon resin coating used herein was one prepared by crosslinking a chlorotrifluoroethylene/acrylic copolymer (base polymer) with an isocyanate curing agent. In the paint, 13 parts by mass of the base polymer was mixed with 1 part by mass of the curing agent. The paint was then diluted with a thinner at a suitable dilution ratio to give a coating composition. The aluminum alloy sheet test piece was immersed in the coating composition so as to maximize the uniformity of a coating, and the applied coating composition on the outermost surface of the test piece was dried to give a fluorocarbon resin coating having an average thickness of 5 μm.
[0072] High Temperature Corrosion Test
[0073] Initially, an artificial seawater (“Aquamarine” for metal corrosion test; supplied by Yashima Pure Chemicals, Co., Ltd.) was diluted 20-folds, and 0.13 N aqueous sodium hydroxide solution was added to adjust the artificial seawater to have a pH of 8.2, to give a test fluid. Independently, each of the test pieces according to Examples and Comparative Examples was fixed to a plastic sample holder. Specifically, the sample holder grasped edges of the test piece to allow the test piece to stand. The test piece held by the sample holder was placed in an autoclave, the test fluid was fed into the autoclave, and the autoclave was hermetically sealed.
[0074] The temperature was raised to a predetermined temperature and held for two weeks. In this procedure, the pressure was not controlled and allowed to be a vapor pressure. Two weeks later, the temperature was returned to normal atmospheric temperature (room temperature), and the sample holder was taken out from the autoclave, from which the test piece was recovered.
[0075] Evaluation
[0076] The corrosion resistance of the coating was evaluated by determining the adhesion of the coating after the high temperature corrosion test (accelerated corrosion test). Specifically, the test piece recovered from the test fluid was dried at 50° C. for 24 hours, and subjected to a cross-cut adhesion test. In the cross-cut adhesion test, one hundred 1-mm square cross cuts were formed on the coating of the test piece, and a tape was attached thereto and then peeled therefrom according to the method specified in JIS K 5600-5-6.
[0077] Table 1 shows the results of Examples 1 to 4 according to the present invention. In Examples 1 to 4 in Table 1, the test pieces had different thicknesses of the anodic oxide layer and had different thicknesses of the organic phosphonic acid primer coating, but none of their coatings was peeled off upon tape peeling in the cross-cut adhesion tests.
[0078] In contrast, Table 2 shows the results of Comparative Examples 1 to 4. In Comparative Examples 1 and 2, no anodic oxide layer was formed. In Comparative Examples 3 and 4, an anodic oxide layer was formed but no organic phosphonic acid primer coating was formed. The test pieces according to Comparative Examples 1 and 2, having no anodic oxide layer, showed coating residual rates of 12/100 (12 cross cuts out of 100 cross cuts remained unpeeled) and 28/100 (28 cross cuts out of 100 cross cuts remained unpeeled), respectively, upon tape peeling in the cross-cut adhesion tests. In the test pieces according to Comparative Examples 3 and 4, having no organic phosphonic acid primer coating, all hundred cross cuts of the coating were peeled off (i.e., no cross cut remained unpeeled; 0/100) upon tape peeling.
[0079] These results demonstrate that the anodic oxidation of the surface of an aluminum alloy base material and the formation of an organic phosphonic acid primer coating enable the formation of a fluorocarbon resin coating with satisfactory adhesion to thereby significantly improve the corrosion resistance of the coating.
[0000]
TABLE 1
Aluminum alloy
Treatment with organic phosphonic acid
Anodic
Immersion
Immersion
Average thickness of
oxide layer
Concentration
temperature
period
coating
Result*
Category
Number
Type
(μm)
Agent
(g/l)
(° C.)
(second)
(μm)
(2 weeks later)
Examples
1
3003
5
vinylphosphonic acid
10
65
10
5
100/100
2
3003
5
vinylphosphonic acid
10
65
120
5
100/100
3
3003
20
vinylphosphonic acid
10
65
10
5
100/100
4
3003
20
vinylphosphonic acid
10
65
120
5
100/100
*Result: The result of the test piece upon tape peeling in the cross-cut adhesion test after holding the test piece at high temperatures. The result is indicated as a residual rate of cross cuts, i.e., how many cross cuts out of hundred cross cuts remain unpeeled.
[0000]
TABLE 2
Aluminum alloy
Treatment with organic phosphonic acid
Anodic oxide
Immersion
Immersion
Average thickness
layer
Concentration
temperature
period
of coating
Result*
Category
Number
Type
(μm)
Agent
(g/l)
(° C.)
(second)
(μm)
(2 weeks later)
Comparative
1
3003
none
vinylphosphonic acid
10
65
10
5
12/100
Examples
2
3003
none
vinylphosphonic acid
10
65
120
5
28/100
3
3003
5
none
none
none
none
5
0/100
4
3003
20
none
none
none
none
5
0/100
*Result: The result of the test piece upon tape peeling in the cross-cut adhesion test after holding the test pieces at high temperatures. The result is indicated as a residual rate of cross cuts, i.e., how many cross cuts out of hundred cross cuts remain unpeeled.
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Disclosed are an aluminum alloy material and a plate heat exchanger using the aluminum alloy material, both of which have superior corrosion resistance. Specifically, the aluminum alloy material includes an aluminum alloy base material having an anodic oxide layer with an average thickness of 1 to 20 μm as its surface layer, an organic phosphonic acid primer coating arranged on the surface of the aluminum alloy base material, and a fluorocarbon resin coating arranged on the surface of the organic phosphonic acid primer coating and having an average thickness of to 100 μm after drying.
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FIELD OF THE INVENTION
The present invention relates generally to networked services, and relates more particularly to admission control decisions made in respect of the provision of networked application services.
BACKGROUND
An existing admission control strategy used in the provision of web-hosting services is a “tail-dropping” strategy, which rejects a job when the queue length exceeds a specified bound. Chen et al (An Admission Control Scheme for Predictable Server Response Time for Web Accesses, 10 th International World Wide Web Conference , May 2001, Hong Kong) present a prediction-based admission control scheme that decides to accept or reject jobs based on the predicted workload.
This prediction-based strategy described by Chen et al is an improvement over the existing tail-dropping strategy. Using such a prediction-based strategy incorporates variable workload, rather than simply specifying conditions in which jobs are dropped, per the existing tail-dropping strategy.
The approach described by Chen et al is certainly an improvement over existing techniques. This approach, however, is still relatively unsophisticated. Issues relating to commercial provision of networked services are unaddressed by the control strategy proposed by Chen et al. Thus, a need clearly exists for an improved manner of admission control for networked services.
SUMMARY
A prediction-based online admission control scheme for incoming jobs is described herein. This scheme has an explicit objective of optimizing a predetermined utility function. An algorithmic procedural approach is used. The input to the algorithmic procedure is a set of jobs to a network service. Each job carries information about the length of the job. The job, in this context, can either be a request or a connection depending on the granularity of the service. An output of the algorithmic procedure is a selected subset of jobs that can be served within the capacity constraints of the network service, such that the predetermined utility function is approximately optimized (for example, minimized or maximized) depending on the context of the particular application.
An algorithmic methodology is presented for admission control, for jobs characterized by (i) the reward such jobs generate when admitted, (ii) the penalty such jobs incur if rejected (or not served), and (iii) the service time required to perform the job, for a single resource. Information concerning incoming jobs is, of course, not available a priori. Rather, admission control decisions are made as jobs arrive. The described methodology is readily extended, as also described herein, for admission-controlled jobs that are serviced using multiple resources.
The interposition of a service proxy that provides admission control functionality has various associated advantages. The service can be operated remotely, and different services can be provided on different networked computers, while retaining a single contact point for clients. A balanced strategy is implemented, which takes into account the length of the job, the reward/penalty of the job and the estimated system utilization into account. Short-term prediction is used to adapt an offline strategy to appropriately work in an online context.
Criteria can be specified upon which to select jobs that are to be dropped. Hence, profits can be increased by servicing an “optimal” request set, which is advantageous in a variable workload environment typical of network-services.
An extension can be made to jobs that require multiple resources, either simultaneously or sequentially. An extension can also be made to service level agreements (SLAs) that have multiple gradations, instead of a binary follow/do not follow QoS condition.
DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic representation of a system architecture involving a client and a service that interact using a request/response model.
FIG. 2 is a schematic representation of a modified system architecture that introduces a proxy between the client and service represented in FIG. 1 .
FIG. 3 is a schematic representation of the proxy represented in FIG. 2 .
FIG. 4 is a schematic representation of an architecture of the type represented in FIG. 2 , which can enforce request-level admission control.
FIG. 5 is a flowchart of steps involved in controlling request-level admission control.
FIG. 6 is a schematic representation of an example of an extension of the described techniques to multiple resources.
FIG. 7 is a schematic representation of a computer system suitable for performing the techniques described herein.
FIG. 8 is a flowchart of steps involved in admission control as described herein.
DETAILED DESCRIPTION
A network service is a remotely-accessible software program that offers a well-defined interface to its clients. Such an interface is typically referred to as an application programming interface (API). FIG. 1 schematically represents an architecture of a network service. Typically, a client 110 accesses a service 170 by sending requests 130 that conform to the service's API 160 , using a library 120 provided to the client 110 by the service provider. The service 170 in turn processes the request 130 and returns a response 180 .
In the present case, this existing arrangement is modified by introducing a proxy between the client 110 and service 170 , as schematically represented in FIG. 2 . The proxy 150 offers the same interface (API 140 ) as the service 170 the proxy 150 represents. The client 110 therefore remains unaware of the interposition of the proxy 150 . The proxy 150 interacts with the service 170 (which may be operated on a remote computer), and makes admission control decisions on behalf of the service 170 .
FIG. 3 schematically represents the internal structure of a proxy 150 , which has three primary parts: a request-to-resource mapper (RRM 310 ), predictor 320 and admission controller 330 . The RRM 310 maps attributes of a request to the expected resource requirements for serving the request. The predictor 320 makes a short-term prediction for the jobs and the corresponding service time distribution. The admission controller 330 decides whether to accept or reject a request, using techniques described in a subsection below, entitled “Admission control methodology”.
EXAMPLE
FIG. 4 schematically represents the architecture of a system that provides network services and has the ability to enforce request-level admission control. The network service (Service 1 , Service 2 , . . . Service N) is accessible over a network (the Worldwide Web in this example) using a specific set of standard protocols.
A client 110 typically sends requests 130 to the network service encoded using the SOAP protocol, with HTTP as the communication mechanism. These requests 130 are directed to a SOAP server 410 , at a particular location on the Internet specified using a uniform resource locator (URL).
A SOAP server 410 has a Servlet Container 420 (which is a web server capable of running servlets) that receives the request and usually directs the request to the appropriate service 140 pre-registered with the Servlet Container 420 . In the present case, a proxy 430 is substituted for each web service 440 . That is, instead of registering a web service 440 with the SOAP server 410 , its corresponding proxy 430 is instead registered. As before, the proxy 430 offers the same API as the service 440 , and thus the client 110 and the SOAP server 410 remain unaware of this substitution.
The Refresh criterion is satisfied if the proxy has not fetched the estimated capacity utilization for the future from the service for the last n jobs or if a predetermined time T has elapsed, since the previous refresh.
Control Flow
Step 510 A client 110 sends a request to the SOAP server 410 .
Step 520 The SOAP server 410 unmarshalls the request parameters of the request sent in step 610 , and calls the appropriate proxy 430 .
Step 530 The proxy 430 decides whether the proxy 430 needs to update its capacity information based on the Refresh criterion, outlined below. If so, the proxy 430 requests the service 440 to send the currently available capacity.
Step 540 The admission controller 330 decides whether to service the request using the techniques described below, which use the resource requirements provided by RRM 310 , and the predictor 320 and the estimated capacity utilization of the service resources to arrive at a decision.
Step 550 If the admission controller 330 decides to service the request, the admission controller 330 forwards the request to the service 170 and awaits response. Otherwise, the admission controller 330 sends a “busy” response to the client 110 .
Admission Control Methodology
More requests can be serviced if requests that collide with a only small number of other requests are scheduled. In this context, request R 1 is said to be colliding with another request R 2 if only one of the two requests R 1 and R 2 can be scheduled, while satisfying a resource capacity constraint determined by the capacity of the hardware that is used to service the requests.
If a request R 1 has an ending time greater than the ending time of request R 2 , and R 1 and R 2 can both be started without violating the capacity constraint, then the conflict set of R 1 (that is, the set of all requests that collide with R 1 ) is a superset of the conflict set of R 2 . Hence, if only one of R 1 and R 2 can be serviced, then R 2 is desirably serviced in preference to R 1 .
A schedule of arriving requests is not known a priori when decisions are made to accept or reject requests. One recognizes, however, that requests have rewards and penalties associated with these requests. An objective then is to maximize the sum of available rewards taking into account incurred penalties.
As foreknowledge does not exist of when requests will arrive in future, admission control decisions are made based upon a prediction of the short-term future arrival of requests. A measure of profit per unit capacity is used as a criterion for making an admission control decision. A strategy is adopted that takes into account both the profit (rewards and penalties), and the length of the remaining job.
To further elaborate, when a request R 1 (having reward r 1 and an end time d 1 ) arrives, a decision horizon is defined as the time between the start and the end of the request R 1 . A spare capacity array, called the available array, is computed for the decision horizon, based on the requests that are already scheduled. The available array is indexed against time. Each entry t in the array represents the amount of resource that is available at time t, if no further requests are admitted. Then capacity is pre-reserved for some of the jobs that are expected to arrive (based on the results of a short-term prediction over the decision horizon). The strategy is to pre-reserve capacity for an expected job R 2 (having reward r 2 and end time d 2 ), if the criteria of Equation (1) below is satisfied.
r 1 −r 2 <p ( d 1 −d 2 )·( r E +p E ) (1)
In Equation (1) above, p(d 1 −d 2 ) represents the probability of a new job being serviced within (d 1 −d 2 ) duration; r E represents the expected reward of the job; and p E represents the expected penalty of the job.
If, after pre-reserving capacity for all such requests R 2 that satisfy Equation (1) above, spare capacity remains to schedule request R 1 , then request R 1 is accepted. A request with a high reward has a higher chance of selection, as the relative reward (r 1 −r 2 ) is greater in value, and is not likely to be displacing capacity for future requests that might generate greater rewards. If, however, r 1 is relatively small then the inequality of Equation (1) above is satisfied. This is because if r 1 <r 2 then r 1 less r 2 is less than zero. Consequently, space for expected requests may be reserved in preference to scheduling the current request. This increases the chance of R 1 being rejected. Also, if a request has a large duration its end-time d 1 is later and, consequently, p(d 1 −d 2 ) is greater. Accordingly, capacity may be reserved for shorter jobs, thus causing R 1 to be rejected.
Table 1 below presents pseudo-code that describes the function of an admission control algorithm.
TABLE 1
1
function schedule
2
for every element j in the available capacity array
3
futureRequests
[
j
]
=
L
*
∑
i
=
1
d
-
j
(
P
(
serviceTime
=
i
)
*
f
(
d
,
i
,
j
)
)
4
backlog = 0
5
for k = 1 to j
6
backlog = backlog + futureRequests [k] *
P(serviceTime = (j − k))
7
end-for
8
capacityLeft = available [j] − (backlog +
futureRequests [j])
9
if(capacityLeft ≦ 1)
10
return false
11
end-if
12
end-for
13
return true
14
end function
In the pseudo-code of Table 1, f(d,i,j) is 1 if currentReward is less than or equal to the expectedReward and the probability of a new job arriving and finishing in (d−j−i) time, multiplied by penalty for rejecting a job. This is referred to as the High Profit Criteria.
The currentReward is the reward associated with the request under consideration, and
expectedReward is the sum of the rewards of the current expected request and the expected request in the remaining time in the decision horizon, namely length of the available array—j.
The above-described methodology assumes that exact system capacity information is available when a request is received and an admission control decision is required. This, however, may not be the case, and two cases are outlined below. The above-described methodology extends to these two cases listed below.
Due to the refresh criterion, exact system information may not be available for the capacity utilized when the admission control decision is made (that is, when a request R arrives). The system information for requests that arrived until time t 0 is available and a new request arrives at time t 1 which is later than t 0 . However, the request R can be replaced by a request R′, which starts at to and has all other properties identical to R.
Request R′ is assumed to clear part of the horizon from t 0 to t 1 . That is, the algorithm is initialized with j=t 1 −t 0 . If the request R′ clears the remaining horizon after reserving space for requests satisfying the HighProfit criterion, the request R is serviced. Instead of checking whether R should be serviced, the admission control criterion (ACC) is checked for another request R′, and if R′ clears the ACC, R is serviced.
In cases in which the request can be queued and serviced later (that is, a service level agreement between a service provider and a client has a turnaround time greater than the service time of the request), the request is continually tried to service. Consider an example of a request R of duration D that arrives at time to and has a turnaround time D+E. An attempt is made to schedule R at time t 0 . If, however, this attempt fails at some time t 1 in the decision horizon, further attempt is made to schedule R at time t 1 (using the extended methodology described above, which compensates for the lack of information of requests which arrived in time t 0 to t 1 ). This procedure is repeated until either the request R is serviced or time t 0 +E elapses, in which case, the request is rejected.
Extensions
The above-described methodology can be extended when multiple resources are present. Capacity is reserved for expected requests that satisfy the profit per unit capacity criterion in all dimensions (resources). That is, the admission controller module is run with reservation for only those future requests that satisfy the High Profit Criteria for all resources.
A conservative estimate is made of expected requests, as expected rewards in the future are appropriately discounted to reflect the possibility that such rewards may not occur. For example, while making the admission control decision for R 1 , resources 1 and 2 are reserved only for R 4 and not R 2 or R 3 , which satisfy the High Profit Criterion for only one of the resources. On the other hand, R 4 satisfies the High Profit Criteria in all dimensions (resources). In this example, all requests are assumed to have the same reward and penalty. FIG. 6 schematically represents an example of this extension to multiple resources for requests r 1 and r 2 .
The above-described methodology can be extended to cases in which a request requires multiple resources in a sequential manner. That is, if a request may require r 1 first and then r 2 . In such a scenario, a check is made of whether all resources (that is, both r 1 and r 2 ) can be given to the request at the time the request requires such resources, after reserving resource for requests satisfying the HighProfit Criteria for individual resources. To elaborate, if a request needs resource 1 from time t 1 to t 2 and then resource 2 from t 2 to t 3 , the request is serviced only if the request is able to access both resources 1 and 2 . That is, the request is able to clear the AC algorithm for resource 1 at t 1 and resource 2 at t 2 .
This methodology can also be extended to multiple-grade SLAs in which a client request has different rewards for different values of SLA parameters instead of a single value, which meets or does not meet the requirements of the SLA. For this modification, the request is not rejected outright if the request fails the admission control criteria for the best grade of its SLA. Instead, a check is made of whether the request can be serviced in the next grade specified in the SLA and so on, until service level grades are exhausted or the request can be serviced.
Computer Hardware and Software
FIG. 7 is a schematic representation of a computer system 700 that can be used to perform steps in a process that implement the techniques described herein. The computer system 700 is provided for executing computer software that is programmed to assist in performing the described techniques. This computer software executes under a suitable operating system installed on the computer system 700 .
The computer software involves a set of programmed logic instructions that are able to be interpreted by the computer system 700 for instructing the computer system 700 to perform predetermined functions specified by those instructions. The computer software can be an expression recorded in any language, code or notation, comprising a set of instructions intended to cause a compatible information processing system to perform particular functions, either directly or after conversion to another language, code or notation.
The computer software is programmed by a computer program comprising statements in an appropriate computer language. The computer program is processed using a compiler into computer software that has a binary format suitable for execution by the operating system. The computer software is programmed in a manner that involves various software components, or code means, that perform particular steps in the process of the described techniques.
The components of the computer system 700 include: a computer 720 , input devices 710 , 715 and video display 790 . The computer 720 includes: processor 740 , memory module 750 , input/output (I/O) interfaces 760 , 765 , video interface 745 , and storage device 755 .
The processor 740 is a central processing unit (CPU) that executes the operating system and the computer software executing under the operating system. The memory module 750 includes random access memory (RAM) and read-only memory (ROM), and is used under direction of the processor 740 .
The video interface 745 is connected to video display 790 and provides video signals for display on the video display 790 . User input to operate the computer 720 is provided from input devices 710 , 715 consisting of keyboard 710 and mouse 715 . The storage device 755 can include a disk drive or any other suitable non-volatile storage medium.
Each of the components of the computer 720 is connected to a bus 730 that includes data, address, and control buses, to allow these components to communicate with each other via the bus 730 .
The computer system 700 can be connected to one or more other similar computers via a input/output (I/O) interface 765 using a communication channel 785 to a network 780 , represented as the Internet.
The computer software program may be provided as a computer program product, and recorded on a portable storage medium. In this case, the computer software program is accessed by the computer system 700 from the storage device 755 . Alternatively, the computer software can be accessed directly from the network 780 by the computer 720 . In either case, a user can interact with the computer system 700 using the keyboard 710 and mouse 715 to operate the programmed computer software executing on the computer 720 .
The computer system 700 is described for illustrative purposes: other configurations or types of computer systems can be equally well used to implement the described techniques. The foregoing is only an example of a particular type of computer system suitable for implementing the described techniques.
Overview
A method, a computer system and computer software are described herein in the context of admission control for network services. In overview, the methodology described herein relates to a prediction-based strategy for deciding whether a job is accepted or rejected, based on attributes of the job. Such attributes include, for example, reward, penalty, resource requirements, and current resource utilization. By contrast, existing techniques take current resource utililization into account in admission control schemes.
FIG. 8 flowcharts steps involved in the described procedure for admission control. In step 810 , the arrival of incoming requests is predicted. In step 820 , the system capacity consumed by the expected requests is estimated. In step 830 , incoming requests are admitted or rejected based upon the estimated spare capacity available to service such requests.
The techniques described herein can be implemented with relatively little computation complexity, which is desirable for real-time implementation. The described algorithm is probably optimal in an offline, uni-dimensional job setting. An offline algorithm is one that assumes that a priori information is available concerning all the requests (and their service times) that will arrive in future. A uni-dimensional job setting denotes that there is a single resource that is admission controlled. The described algorithm uses prediction to simulate the offline algorithm in an online setting.
Various alterations and modifications can be made to the techniques and arrangements described herein, as would be apparent to one skilled in the relevant art.
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Prediction-based online admission control for incoming jobs has an explicit objective of optimizing a utility function. The input to an algorithmic procedure is a set of requests made in respect of a network service. Each request has information about the length of the request. An output of the algorithmic procedure is a selected subset of requests that can be served within the capacity constraints of the network service, such that the utility function is approximately optimized (for example, minimized or maximized) depending on the context of the particular application.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for improving the transient thermal properties of air-lubricated hydrostatic bearings for the main spindles of lathes, machining centers, turning centers, and other precision machine tools.
2. Prior Art Statement
In the prior art, when precision machining is performed with various types of precision machine tools, air-lubricated hydrostatic bearings are used for the main spindle bearings. The entire machine tool is installed within a constant-temperature chamber, and the air supplied to the spindle bearings is supplied at the same temperature as the temperature within the constant-temperature chamber. This method is used to homogenize the temperature distribution of the machine tool.
A main spindle lubricated by air in this manner innately has low friction, and the lubricating air will absorb and exhaust any heat generated, so very little thermal deformation would occur. However, when extremely high precision machining is performed, even thermal deformation on the order of several μm can adversely affect precision, thus requiring measures to reduce such thermal deformation.
In order to reduce this thermal deformation, the entire machine is externally cooled using oil, water, air or the like.
However, the method of external cooling of the entire machine tends to cool even unnecessary areas, requiring the addition of an inordinate amount of energy in comparison to the magnitude of the decrease in thermal displacement, thus degrading efficiency.
To solve this problem, the inventor of the present invention has proposed a method of reducing displacement by supplying the air spindle bearings with air of a temperature lower than the temperature within the constant-temperature chamber as lubricating air (Japanese Patent Application Public Disclosure No. 3(1991)-274737).
This newly proposed method can effectively reduce the absolute value of the thermal displacement in the steady state. However, this method requires a warm-up time of roughly 6-7 hours until the thermal displacement reaches the steady state, so a reduction in this warm-up time is desirable.
The present invention came about in light of the above, and its purpose is to provide a method for improving the transient thermal properties that can effectively reduce the absolute value of the thermal displacement in the steady state, and moreover, can shorten the warm-up time until the thermal displacement reaches a steady state.
SUMMARY OF THE INVENTION
The method of the present invention for improving the transient thermal properties of air-lubricated hydrostatic bearings for the main spindles of precision machine tools, intended to achieve this purpose, comprises the steps of installing an entire precision machine tool that has a main spindle with an air-lubricated hydrostatic bearing in a temperature-controlled constant-temperature environment, and raising the temperature of the lubricating air supplied to the air-lubricated hydrostatic bearing above the temperature of the constant-temperature environment until the thermal displacement of the main spindle reaches a previously-determined target value, and thereafter lowering it below the temperature of the constant-temperature environment.
As described above, by supplying the spindle bearing with lubricating air of a temperature higher than the constant-temperature environment, displacement in the spindle bearing increases rapidly. When this displacement reaches the target value, the temperature of the lubricating air supplied is reduced to below the temperature of the constant-temperature environment. This target value is a fixed temperature lower than room temperature, previously determined to be the ultimate value of the thermal displacement reached when air is supplied. By changing the temperature of the lubricating air as described above, the change in thermal displacement in the spindle bearing over time assumes an ideal shape, allowing the warm-up time to be shortened, simplifying the process of compensation by NC or the like.
These and other objects and features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional diagram that shows the bearing structure of a main spindle with an air-lubricated hydrostatic bearing.
FIG. 2 is a graph showing the history of the thermal displacement of the bearing when the present invention is used.
FIG. 3 is a graph showing the history of the thermal displacement of the bearing when the prior art is used.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an overview of the bearing structure of an air-lubricated hydrostatic bearing for the main spindles of precision machine tools that is subject to reduction of thermal deformation by means of the method of the present invention. A precision machine tool equipped with a main spindle incorporating this air-lubricated hydrostatic bearing is installed in a constant-temperature chamber or other constant-temperature environment maintained at a specific temperature (not shown).
The air-lubricated hydrostatic bearing main spindle in this precision machine tool is configured as a thrust-type high-speed main spindle, arranged such that a stator 1 supports a rotor 2 via a film of lubricating air 3. An air-supply channel is provided upon this stator 1 in order to supply lubricating air to the bearing section.
When the rotor 2 rotates, heat is generated due to the viscous friction of the lubricating air 3 within the bearing accompanying this rotation. In this case, if lubricating air of the same temperature as the set temperature within the constant-temperature chamber is supplied, as in conventional air lubrication methods, this heat conducts to the upper surface of the stator 1 and the lower surface of the rotor. Temperature differences arise with respect to other portions of the stator 1 and rotor 2 that are exposed to external air, and these temperature differences are the cause of thermal deformation of the main spindle.
For example, during long-term operation, thermal deformation on the order of several μm will normally occur.
According to the present invention, first, the steady-state thermal displacement of a bearing provided with lubricating air of a temperature 5° C.-10° C. below the setting temperature of the constant-temperature environment (hereafter called the steady-state temperature) is found experimentally or heuristically. This thermal displacement becomes the target value.
Next, lubricating air is supplied to the bearing together with the start of operation of the bearing. The temperature of the air supplied at this time is higher than the temperature within the constant-temperature environment. Since the purpose of supplying this higher-temperature air is to heat the bearing rapidly, its temperature is roughly 10° C. higher than the temperature of the constant-temperature environment. Accordingly, the bearing is heated by the supplied lubricating air, and its thermal displacement increases rapidly.
Once the thermal displacement reaches the target value set previously, the lubricating air is then supplied with its temperature at the steady-state temperature. Thereby, the thermal displacement of the bearing reaches the steady state.
Once the steady state is reached, lubricating air of a fixed temperature 5° C.-10° C. below the setting temperature of the constant-temperature chamber is supplied. Thereby, as heat is generated within the lubricating air and the temperature of the lubricating air rises, since it was originally of a lower temperature, this retards the development of temperature differences with other parts of the stator 1 and rotor 2 that are exposed to external air. This suppresses thermal deformation of the air-lubricated hydrostatic bearing main spindle, allowing the axial elongation of the main spindle due to heat to be greatly reduced in comparison to the normal case.
A preferred embodiment of this invention is given below.
A precision machine tool equipped with an air-lubricated hydrostatic bearing main spindle whose rotor rotates at a speed of 400 rpm is installed within a constant-temperature chamber with a temperature of 25° C.±0.3° C. Air is supplied to the air-lubricated hydrostatic bearing at a pressure of 4 kgf/cm 2 .
First, 35° C. lubricating air is supplied for roughly 60 minutes after the start of operation of the main spindle, at which time the thermal displacement reaches the target value for thermal displacement of 2.0, and then 15° C. lubricating air is supplied. The state of the thermal displacement of the main spindle is as shown by curve a in FIG. 2, showing that it took roughly 80 minutes to halt the increase in thermal displacement and reach the steady state.
If the target value for thermal displacement is set to 1.5, 35° C. lubricating air is supplied for 40 minutes after the start of operation of the main spindle, at which time the thermal displacement reaches the target value for thermal displacement, and then 15° C. lubricating air is supplied. In this case, the thermal displacement of the main spindle is as shown by curve a in FIG. 2, showing that it took roughly 60 minutes to halt the increase in thermal displacement and reach the steady state.
For comparison, when lubricating air of a temperature the same or lower than the temperature of the constant-temperature environment is supplied as described in the prior art, the results of measuring the state of thermal displacement of the main spindle in this case are shown in the graph of FIG. 3. Curve c shows the case of when 25° C. lubricating air is supplied continuously from the start of operation of the main spindle. Curve d shows the case of when 20° C. lubricating air is supplied continuously from the start of operation of the main spindle. Curve e shows the case of when 15° C. lubricating air is supplied continuously from the start of operation of the main spindle.
As is evident from FIGS. 2 and 3, in contrast to the case of the present invention illustrated by curves a and b on FIG. 2, in which the increase in the thermal displacement of the main spindle was halted and the steady state was reached in roughly one hour, in the case of the prior art illustrated by curves c, d, and e on FIG. 3, this took roughly six hours.
It is thus evident that the present invention can greatly reduce the warm-up time.
Thus, by means of the present invention, a method for improving transient thermal properties can be implemented by which one can effectively reduce the absolute value of the thermal displacement of air-lubricated hydrostatic bearings in the steady state, and moreover, can markedly shorten the warm-up time until the thermal displacement reaches a steady state.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
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A method for improving the transient thermal properties of hydrostatic air main spindles for precision machine tools comprises the steps of installing an entire precision machine tool that has a main spindle with an air-lubricated hydrostatic bearing in a temperature-controlled constant-temperature environment, and raising the temperature of the lubricating air supplied to the air-lubricated hydrostatic bearing above the temperature of the constant-temperature environment until the thermal displacement of the main spindle reaches a target value, and thereafter lowering it below the temperature of the constant-temperature environment.
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TECHNICAL FIELD
[0001] The present invention relates to a medicine comprising a mixture of a prostaglandin compound and a nitric oxide (hereinafter referred to as “NO”) donating compound that is effective in the treatment of ocular hypertension and glaucoma.
BACKGROUND ART
[0002] Presently, eye drop solutions and internal medicines are principally used for reducing ocular tension in the treatment of ocular hypertension and glaucoma. As examples of eye drop solutions, β-blockers such as timolol maleate, carteolol hydrochloride, befunolol hydrochloride, and betaxolol hydrochloride, sympathetic nerve stimulants such as epinephrine and dipivefrine hydrochloride, parasympathetic nerve stimulants such as pilocarpine hydrochloride and carbachol, α-blockers such as bunazosin, αβ-blockers such as nipradilol, and prostaglandin derivatives such as isopropyl unoprostone and latanoprost can be given. As examples of internal medicines, carbonic anhydrase inhibitors such as acetazolamide, methazolamide, and diclofenamide can be given.
[0003] In many cases, the use of only one of these medicines cannot sufficiently control ocular tension. Therefore, the combined use of two or more of these medicines has increased. However,there are cases where the combined use of these medicines does not significantly reduce ocular tension, thereby making the selection of these medicines very difficult.
[0004] Accordingly, an object of the present invention is to provide a medicine that significantly reduces ocular tension resulting from ocular hypertension and glaucoma, in particular, a medicine that effectively reduces ocular tension in cases where the combined use of conventional medicines is not effective.
DISCLOSURE OF THE INVENTION
[0005] To achieve the above object, the present inventors have conducted extensive research of a medicine comprising a prostaglandin compound and a NO-donating compound.
[0006] Of the above medicines, prostaglandin compounds are already known to be effective in reducing ocular tension when used alone. However, the action mechanism of this effect has not yet been fully understood. It is commonly believed that this effect is due to the increased uveoscleral flow rate and there are several opinions regarding the reason. One opinion is that prostaglandin F 2 α causes secretion of MMP. MMP degrades the extracellular matrix of the smooth muscle fibers of the ciliary body (uveoscleral outflow pathway) thereby decreasing outflow resistance and increasing outflow (Lutjen-Drecoll E. and Tamm E., Exp. Eye. Res 47, 761-769, 1988). Another opinion is that the smooth muscle fibers of the ciliary body become relaxed and the cell spacing expands thereby decreasing outflow resistance and increasing outflow (Poyer J F. , Inv. Opht. Vis. Sci. 36, 2461-2465, 1995).
[0007] The inventors of the present invention paid particular attention to the following reports on prostaglandin. As a result of combining a prostaglandin compound (a derivative of prostaglandin F 2 α. in particular) with a prostaglandin receptor, phospholipase A 2 is stimulated, thereby causing arachidonic acid to be produced and released from the biomembrane phospholipid. This arachidonic acid is converted into prostaglandin G 2 by the action of cyclooxygenase then converted into various types of endogenic prostaglandin. In this instance, prostaglandin E 2 and prostaglandin F 2 α are produced and cause the ciliary muscle to become relaxed thereby increasing the uveoscleral flow rate, and as a result, the ocular tension is reduced (Y. K. Sardar, Exp. Eye. Res. 63, 305, 1996 and the like)
[0008] The ocular tension reducing effect of NO donating compounds has already been known in the art. The nitric oxide released by the NO donating compound activates the guanylate cyclase, which increases the amount of cyclic GMP (S. A. Waldman et al, J. Biol. Chem 259, 5946, 1984), and results in reduced ocular tension (J. A. Nathanson et al, Invest. Ophthal. Vis. Sci. Abstr. 29, 323, 1988).
[0009] In general, the combination of several components effective in reducing ocular tension does not greatly improve the overall effect. However, the inventors of the present invention conducted research based on the assumption that a mixture of a prostaglandin compound and an NO donating compound could significantly reduce ocular tension, wherein the nitric oxide released by the NO donating compound not only activates guanylate cyclase but also activates cycloxygenase (D. Salvemini, et al, Proc. Natl. Acad. Sci. USA 90, 7240, 1993) thereby enhancing the conversion of arachidonic acid in the ocular tension reducing mechanism of the prostaglandin compound. As a result, the inventors have discovered that this combination is in fact highly effective in reducing ocular tension, thereby completing the present invention.
[0010] Accordingly, the present invention provides a medicine comprising a prostaglandin compound and an NO donating compound.
[0011] The present invention also provides a method for treating and/or preventing ocular hypertension or glaucoma using the above medicine.
[0012] Since ocular hypertension and glaucoma can be very difficult to treat, there are many cases where these disorders cannot be completely cured using conventional medicines for reducing ocular tension. Experimented use of various combinations of these medicines, which resulted in either no improvement or only a slight improvement in effect, could not achieve a significant improvement in the treatment of these disorders.
[0013] In the medicine of the present invention comprising the combination of a prostaglandin compound and an NO donating compound, the nitric oxide is released from the NO donating compound and enhances the conversion of the arachidonic acid in the ocular tension reducing mechanism of the prostaglandin compound, thereby exhibiting a synergistic effect of the two compounds of significantly increasing the ocular tension reducing effect. Thus, the medicine is not only effective in regular ocular hypertension and glaucoma patients but is also effective in those patients wherein the combined use of several conventional medicines does not significantly reduce ocular tension.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] As the prostaglandin compound used in the medicine of the present invention, all pharmaceutically acceptable prostaglandin compounds, derivatives, and analogues thereof can be given, wherein the derivatives include pharmaceutically acceptable esters and salts thereof.
[0015] As examples of the prostaglandin compound, naturally occurring prostaglandins such as prostagladin (hereinafter referred to as “PG”) D 1 , PGE 1 , PGE 2 , PGE 3 , PGF 1 α, PGF 2 α, PGF 3 α, PGG 2 , PGH 2 , PGI 2 , and PGI 3 , thromboxane A 2 , latanoprost, isopropyl unoprostone, PGF 2 α 1-isopropyl ester, salt of PGF 2 α 1-isopropyl ester-15-propione, and 15-deoxy PGF 2 α can be given without any limitations. These prostaglandin compounds may be used singularly or in combination of two or more.
[0016] Of those given above, prostaglandin F 2 α derivatives are preferably used as the prostaglandin compound in the medicine of the present invention, with PGF 2 α, latonoprost, and isopropyl unoprostene being particularly preferable.
[0017] In the medicine of the present invention, the prostaglandin compound is preferably used in an amount of 0.0001-0.05 w/v %, and particular preferably 0.001-0.01 w/v % of the total amount of the compound.
[0018] As the NO donating compound used in the medicine of the present invention, those that release NO (nitric oxide) in vivo can be given. Examples of the NO donating compound include, but are not limited to, nipradilol, nitroglycerine, isosorbide dinitrate, sodium nitroprusside, N-nitrosoacetyl penicillamine, 3-morpholino-sydnonimine hydrochloride, S-nitroso-N-acetyl-DL-penicillamine (SNAP), S-nitrosoglutathione, 4-phenyl-3-furoxanecarbonitryl, arginine, and sodium nitrite. These NO donating compounds may be used singularly or in combination of two or more.
[0019] Of the above NO donating compounds, nipradilol is particularly preferable. In addition to releasing NO, nipradilol is known to be effective in α,β blocking, which adds an increased effect to the treatment of ocular hypertension and glaucoma.
[0020] In the medicine of the present invention, the NO donating compound is preferably used in an amount of 0.01-5 w/v %, and particular preferably 0.1-1.0 w/v % of the total amount of the compound.
[0021] The medicine of the present invention may be used in the form of an eye drop solution and the like, wherein the prostaglandin and NO donating compounds may be combined into a single preparation or each compound may be separate preparations and administered in order in the form of a medicine kit or the like.
[0022] In the medicine of the present invention, the use of a single preparation comprising both compounds is advantageous in view of convenience. On the other hand, the use of each compound in separate preparations is also advantageous because the method of administration can be determined and the amount of each compound administered can be controlled.
[0023] The medicine of the present invention is preferably used in the form of an eye drop solution. This eye drop solution may comprise the prostaglandin compound and the NO donating compound in separate containers or both the prostaglandin compound and NO donating compound in the same container.
[0024] In the preparation of the above medicine, commonly used base materials, dissolution agents, solubilizers, solvents, wetting agents, emulsifiers, excipient, adhesives, viscous agents, binders, preservatives, antioxidants, stabilizers, surfactants, antiseptics, pH adjustors, and the like may be appropriately used in accordance with the form of the preparation.
EXAMPLES
[0025] The present invention will be described in more detail by the way of examples, which should not be construed as limiting the present invention.
Example 1
[0026] 100 ml of an aqueous solution containing 0.25 w/v % of nipradilol and 100 ml of an aqueous solution containing 0.005 w/v % of latonoprost were prepared separately and combined into a single package to prepare a medicine kit.
Example 2
[0027] 100 ml of an aqueous solution containing 0.1 w/v % of sodium nitroprusside and 100 ml of an aqueous solution containing 0.005 w/v % of latonoprost were prepared separately and combined into a single package to prepare a medicine kit.
Examples 3 and 4
[0028] The medicines of Examples 3 and 4 were prepared using the ingredients and amounts shown in Table 1.
TABLE 1 Example 3 Example 4 nipradilol 0.25 g nitroprusside 0.10 g Na latanoprost 0.005 g latanoprost 0.005 g purified appropriate amount purified water appropriate amount water total amount 100 mL total amount 100 mL
Test Example 1
[0029] Domesticated rabbits intravenously administered with 100 μl of a 5 w/v % hypertonic saline solution were used as ocular hypertension models. After intravenously administering the hypertonic saline solution, 50 μl of each of the eye drop solutions were administered and the ocular tension was measured 60 and 120 minutes thereafter.
[0030] A physiological saline solution, a 0.005 w/v % latonoprost aqueous solution (latanoprost), a 0.25 w/v % nipradilol aqueous solution (nipradilol), a combination of latanoprost and nipradilol (Example 1), and a combination of a 0.5 w/v % indomethacin aqueous solution (indomethacin), latonoprost, and nipradilol were used as the eye drop solutions.
[0031] When nipradilol and latanoprost were used in combination, nipradilol was administered first and latanoprost was administered five minutes thereafter. Furthermore, when indomethacin was used, the indomethacin was administered five minutes before the administration of nipradilol. The results are shown in Table 2, wherein the ocular tension change (mmHg), the change in ocular tension after administration, is shown as the mean value ± the standard error.
TABLE 2 No. of Ocular tension change (mmHg) Eye drop solution specimens 60 minutes 120 minutes Physiological saline 6 24.8 ± 1.7 16.2 ± 1.6 solution Latanoprost 6 22.7 ± 1.2 9.8 ± 1.9 Nipradilol 6 14.7 ± 1.7* 7.3 ± 1.6* Nipradilol + Latanoprost 6 5.3 ± 3.3** ♯♯b 1.7 ± 2.7** ♯ (Example 1) Indomethacin + 6 13.3 ± 3.7* ♯ 8.2 ± 1.7* Nipradilol + Latanoprost
Test Example 2
[0032] Domesticated rabbits intravitreously administered with 100 μl of a 5 w/v % hypertonic saline solution were used as ocular hypertension models. After intravitreously administering the hypertonic saline solution, 50 μl of each of the eye drop solutions was administered, and the ocular tension was measured 60 and 120 minutes thereafter.
[0033] A 0.1 w/v % sodium nitroprusside aqueous solution (sodium nitroprusside), a combination of the sodium nitroprusside and a 0.005 w/v % latanoprost aqueous solution (latanoprost) (Example 2) and a combination of a 0.5 w/v % indomethacin aqueous solution (indomethacin) , latanoprost, and sodium nitroprusside were used as the eye drop solutions.
[0034] When sodium nitroprusside and latanoprost were used in combination, sodium nitroprusside was administered first and latanoprost was administered five minutes thereafter. Furthermore, when indomethacin was used, the indomethacin was administered five minutes before administration of sodium nitroprusside. The results are shown in Table 3, wherein the ocular tension reduction (mmHg), the change in ocular tension after administration, is shown as the mean value ± the standard error.
TABLE 3 No. of Ocular tension reduction (mmHg) Eye drop solution specimens 60 minutes 120 minutes Sodium nitroprusside 5 18.0 ± 2.4 9.4 ± 2.5 Sodium nitroprusside + 5 4.8 ± 3.9 −2.8 ± 1.3** latanoprost (Example 2) Indomethacin + sodium 5 22.8 ± 2.9 ## 12.4 ± 6.3 ## nitroprusside + latanoprost
[0035] The results of the above Test Examples 1 and 2 show that the combination of the NO donating compound and prostaglandin compound significantly suppresses an increase in ocular tension when compared with the case where these compounds are individually used. The effect of this combination disappeared with the addition of indomethacin. This suggests that the effect of preventing an increase in ocular tension possessed by the combination of the NO donating compound and latanoprost is a result of cycloxygenase activation. The strengthened production of various endogenic prostaglandins resulting from a synergistic effect of the endogenic arachidonic acid derivative produced by the activation of phospholipase A2 by latanoprost and the activation of cycloxygenase by NO is believed to have stimulated production of PGE 2 , which is known to be effective for ocular tension reduction in domesticated rabbits.
INDUSTRIAL APPLICABILITY
[0036] A medicine comprising a combination of a prostaglandin compound and NO donating compound significantly suppresses an increase in ocular tension when compared to the compounds used individually.
[0037] Therefore, the medicine of the present invention is effective in treating persons affected by ocular hypertension and glaucoma.
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It is intended to provide medicines having a higher ocular tension-lowering effect on ocular hypertension and glaucoma. Because of showing an excellent effect of lowering ocular tension, medicines comprising a combination of a prostaglandin compound with an NO-donating compound are useful in treating ocular hypertension and glaucoma.
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FIELD OF THE INVENTION
[0001] The present invention relates to the manufacture of an aqueous slow-setting bitumen-aggregate mix suitable for cold paving of roads, parking places, sidewalks, and the like. The bitumen-aggregate mix is manufactured by mixing a mineral aggregate, water, and a cationic oil-in-water bitumen emulsion containing a salt between a tertiary polyamine and an acid as an emulsifying and cohesion-increasing agent.
BACKGROUND OF THE INVENTION
[0002] It is well-known in the art to prepare cationic oil-in-water emulsions of bitumen and to mix these emulsions with inorganic mineral aggregates. When mineral aggregates and the cationic emulsion are mixed, the emulsion will “break” due to the attraction between the positively charged bitumen droplets and the negatively charged aggregate surfaces. The cationic bitumen droplets will deposit on the aggregate surfaces and be bonded to the aggregates by the electrostatic action at the interface between the bitumen droplets and the aggregates. As emulsifiers, several salts between acids and amine compounds have been suggested. Frequently, acidified amidoamines, imidazolines, fatty polyamines, quaternary ammonium compounds, and mixtures thereof are used. The acid used normally is hydrochloric acid, but also phosphoric acids and other acids containing one or more acid hydrogen atoms have been used.
[0003] A variety of polyamines or derivates of polyamines have been used or suggested for use as emulsifiers or anti-stripping agents in bitumen compositions.
[0004] Thus, U.S. Pat. No. 3,259,512 discloses a branched polyamine where the branched group contains at least one nitrogen-bonded aminoalkylene group. These polyamines contain at least three primary amino groups and at least one tertiary amino group. The branched polyamines are used as de-emulsifiers for aqueous emulsions or as asphalt additives or as antistripping agents for asphalt-mineral aggregate compositions.
[0005] U.S. Pat. No. 3,518,101 describes an aqueous asphalt emulsion which contains, as an emulsifier, a salt between a polybasic acid selected from the group consisting of oxalic acid, tartaric acid, and citric acid, and a diamine compound containing an alkyl group having about 12 to about 22 carbon atoms. The amine groups could be primary, secondary and/or tertiary.
[0006] U.S. Pat. No. 3,615,797 discloses a method of making a bitumen with high adhesion properties by adding to the bitumen an ethylene oxide condensate of a long-chain alkyl triamine.
[0007] U.S. Pat. No. 4,967,008 discloses polypropylene polyamines which are partially methylated. The compounds are said to have surfactant properties and may, for example, be beneficial as asphalt emulsifiers and antistripping agents.
[0008] U.S. Pat. No. 5,073,297 discloses an aqueous bituminous emulsion-aggregate obtained by emulsifying bitumen in water with a particular cationic emulsifier which is a reaction product between modified polyamines and certain polycarboxylic acids and anhydrides. In the preparation of the bituminous emulsion, an acid solution of the emulsifier is used. For instance, hydrochloric, sulphuric, and phosphoric acid or the like can be added until a pH-value below 7 is reached and a clear emulsifier solution is obtained.
[0009] U.S. Pat. No. 6,048,905 describes a number of amine compounds suitable as an emulsifier for bitumen. For instance, the amine compounds can be monoamines or polyamines having an aliphatic substituent containing 8-22 carbon atoms. The amines can also be alkoxylated with ethylene oxide and propylene oxide.
[0010] When paving, it is today a general practice to prepare a cold mix in a plant and to transport the mix to the work site for paving. Therefore, it is of crucial importance that the mix retains a suitable consistency for paving for at least some hours after mixing. In addition, a strong cohesion between the bitumen and the aggregates as well as between the bitumen and the surface paved is essential. Further, a dense bitumen coating on the aggregates is desired.
SUMMARY OF THE INVENTION
[0011] It has now been found that by adding a salt of a specific polyamine it is possible to prepare an aqueous slow-setting bitumen-aggregate mix suitable for cold pavement. The cold mix has an open time of at least two hours and within 24 hours develops a high cohesion between the bitumen and the surface of the aggregates as well as between the bitumen and the paved surface. It also provides a dense bituminous coating of the solid surfaces.
[0012] According to the invention, the slow-setting bitumen-aggregate mix for cold paving is manufactured by
a) preparing a cationic oil-in-water emulsion of bitumen in the presence of an emulsifier containing
i) a tertiary polyamine selected from the group consisting of a di(C 2 -C 3 alkylene)triamine, a tri(C 2 -C 3 alkylene)tetraamine, a tetra(C 2 -C 3 alkylene)pentaamine, a penta(C 2 -C 3 alkylene)hexaamine, a hexa(C 2 -C 3 alkylene)heptaamine or a mixture thereof, which amine compounds have only tertiary amine groups and one or two substituents containing an aliphatic group of 8-22 carbon atoms, bound to a nitrogen atom, while the remaining substituents are methyl groups, and ii) an acid present in such an amount that the aqueous emulsion obtains a pH value from 1-6, preferably 1.5-5, and
b) mixing the aqueous emulsion obtained with a solid aggregate.
[0017] The present invention also comprises a tertiary polyamine selected from said group of tertiary polyamines or salts thereof with an acid, a process for the production of said tertiary polyamine, as well as the use of the salt of the tertiary polyamine as an emulsifying or cohesion-increasing agent.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The tertiary polyamines of the invention comprise amines which can be linear or branched. The substituents which are not methyl groups suitably are aliphatic groups with 8-22 carbon atoms, preferably aliphatic groups with 10-20 carbon atoms. Further, the aliphatic groups can be straight or branched, saturated or unsaturated. Examples of suitable aliphatic groups are decyl, dodecyl, myristyl, cetyl, stearyl, oleyl, coco alkyl, tallow alkyl, tall alkyl, rapeseed alkyl, linseed alkyl, as well as hydrogenated unsaturated aliphatic groups. The C 2 -C 3 alkylene group is ethylene or a propylene, preferably the group —(CH 2 ) 3 —.
[0019] Examples of suitable tertiary polyamines are those of the formula
[0000]
[0000] wherein one or two of the groups R 1 -R 5 are an aliphatic group containing 8-22 carbon atoms and the remaining groups of R 1 , R 2 , R 3 , R 4 , and R 5 are methyl, and n is an integer from 1-5.
[0020] Another class of tertiary polyamines is formed by those of the formula
[0000]
[0000] wherein one or two of the groups R 1 -R 7 are an aliphatic group containing 8-22 carbon atoms and the remaining groups of R 1 -R 7 are methyl, and x, y are numbers from 0-4, and the sum of x and y is 0-4.
[0021] Still another class of tertiary polyamines is
[0000]
[0000] wherein one or two of the groups R 1 -R 6 are an aliphatic group containing 8-22 carbon atoms and the remaining groups of R 1 -R 6 are methyl groups, t is 0-3, r and s are 1-4, and the sum of t, r and s is 2-5.
[0022] The acids can be inorganic or organic and monovalent or polyvalent. Examples of organic acids are carboxylic acids, such as acetic acid, oxalic acid, malonic acid, tartaric acids, maleic acid, succinic acid, and citric acid. Other organic acids are alkyl esters of phosphoric acid. Examples of inorganic acids are hydrochloric acid, sulphuric acids, ortophosphoric acid, and phosphorous acid. Especially preferred are polyvalent acids and hydrochloric acid.
[0023] The polyamines of the invention can be produced by methylation of the corresponding non-methylated or only partially methylated polyamines. The methylation can be performed with conventional methods, for instance methylation with a methyl halide, such as methyl chloride, methyl bromide or methyl iodide, with dimethyl sulfate or dimethyl carbonate. Another method of methylation of the nitrogen atoms is to perform a reductive amination with formaldehyde in the presence of a reducing agent, such as formic acid or hydrogen. If the reducing agent is hydrogen, the process is performed in the presence of a hydrogenation catalyst containing for example nickel, cobalt, copper or boron or a mixture of two or more of these metals.
[0024] Suitable polyamines for methylation are well-known. Thus, suitable polypropylene polyamines can be manufactured by first reacting a primary or secondary amine substituted with one or two aliphatic groups of 8-22 carbon atoms with acrylonitrile, and then performing a hydrogenation step. Thereafter, the nitrilation and hydrogenation steps are repeated until the desired number of nitrogen atoms has been obtained. Polyethylene polyamines suitable for methylation are also known and can be obtained by well-known amination reactions performed in the presence of a dehydrogenation/hydrogenation catalyst. Thus, for instance, a secondary or tertiary monoethanol monoamine with one or two aliphatic substituents of 8-22 carbon atoms or a primary or secondary amine with one or two substituents of 8-22 carbon atoms can, in accordance with well-known principles, be reacted with compounds selected from the group comprising ammonia, monoethanol monoamine, triethanolamine, ethylene diamine, diethylene triamine and/or higher polyethylene polyamines in appropriate amounts.
[0025] Polypropylene polyamines suitable for producing the methylated polalkylene polyamines of formula I can be prepared by first reacting a primary or secondary amine substituted with one or two aliphatic groups of 8-22 carbon atoms with equal molar amounts of acrylonitrile and thereafter performing a catalytic hydrogenation. The nitrilation and hydrogenation steps can then be repeated until the desired number of amine groups has been obtained. The corresponding polyethylene polyamines of formula I can be prepared by reacting, in accordance with well-known principles, a primary or secondary amine having one or two aliphatic groups having 8-22 carbon atoms or the corresponding ethanolamines with monoethanolamine, ethylene diamine, diethylene triamine and/or higher polyethylene polyamines in the presence of a conventional dehydrogenation/hydrogenation catalyst at about 150 to 200° C. Finally, any remaining hydroxyl groups are aminated with ammonia.
[0026] Suitable non-methylated polypropylene polyamines of formula II can be obtained by starting with a primary amine substituted with an aliphatic group of 8-22 carbon atoms. By reacting the primary amine with acrylonitrile in the presence of an acid as catalyst two moles of acrylonitrile can be added to one mole of the amine in one step. The acid is normally removed, after which the alkylaminonitrile is hydrogenated. The reaction can then be continued by adding between one or two equivalents of acrylonitrile, followed by hydrogenation. By repeating the addition of acrylonitrile and hydrogenation, the desired number of amino groups can be obtained. The corresponding polyethylene polyamines can be obtained by reaction between a tertiary diethanolamine substituted with one aliphatic group of 8-22 carbon atoms and ethylene diamine, diethylene triamine and/or monoethanol monoamine. Any remaining hydroxyl groups are finally aminated with ammonia.
[0027] The non-methylated polypropylene polyamines of formula III can be obtained by first reacting one equivalent of acrylonitrile and a primary or secondary amine substituted with one or two aliphatic groups of 8-22 carbon atoms in one or more steps and then hydrogenating the reaction product in one or more steps. In order to create branching, two equivalents of acrylonitrile are added to the intermediate in the presence of an acid as a catalyst, whereupon a hydrogenation takes place. The branched polypropylene polyamine can then be further reacted with acrylonitrile, followed by hydrogenation to obtain the desired number of amine groups. The corresponding polyethylene polyamines of formula III can be prepared for example by reacting triethanolamine and a primary or secondary amine substituted with one or two aliphatic groups of 8-22 carbon atoms in a surplus of triethanolamine in the presence of an amination catalyst. The aminated triethanolamine is recovered from the reaction mixture and then further aminated with ethylene diamine, diethylene triamine and/or monoethanolamine in the presence of hydrogen. Finally, any remaining hydroxyl groups are aminated with ammonia.
[0028] The aggregate is an inorganic material which normally contains a densely graded inorganic material, such as blast furnace slag and minerals, e.g. granite, limestone, and dolomite. The particle size distribution suitably includes both fines and coarser particles. A typical aggregate consists of the following fractions:
[0000]
0-4 mm
44%
4-8 mm
23%
8-12 mm
33%
[0029] Suitable kinds of bitumen for use in the present invention are those commonly used in road paving and in the techniques of cold emulsion mix, slurry seal, microsurfacing, and the like and include but are not limited to those having an AC grade from AC-15 to AC-35. The bitumen used in the present invention also includes petroleum straight asphalt, semiblown asphalt, out-back asphalt, natural asphalt, petroleum tar, pitch, heavy oil, and a mixture of two or more of these products. The bitumen can also be modified with polymers such as SBS and EVA.
[0030] An aqueous bitumen-aggregate mix according to the invention normally contains
[0000] 100 parts by weight of an aggregate,
6-20, preferably 8-15 parts by weight of bitumen,
0.1-3, preferably 0.2-2.5 parts by weight of the salt between the polyamine according to the invention and an acid.
[0031] The aqueous bitumen-aggregate mix can be produced by mixing a blend containing the mineral aggregate and 5-35% of water, calculated on the weight of the aggregate, with 10-40% of the aqueous acidic oil-in-water emulsion of the bitumen, calculated on the weight of the aggregate. Said bitumen emulsion normally contains 50-70% by weight of bitumen, 0.4-20, preferably 2-14% by weight of a salt between an acid and the polyamine according to the invention, and 21-43%, preferably 25-40% by weight of water. The total amount of water in the bitumen-aggregate mix normally is between 12 and 25% by weight of the aggregate.
[0032] Also other components can be present in the bitumen-aggregate mix and in the bitumen emulsion. Thus, the bitumen emulsion can contain other emulsifiers which are nonionic or cationic surfactants containing at least one hydrocarbon group of 6-22 carbon atoms, preferably 8-22 carbon atoms, such as amide compounds, ethyleneoxy-containing amide compounds, acidified amidoamines, ethyleneoxy-containing amidoamines, imidazolines, polyamines, and quaternary ammonium compounds, and mixtures thereof. Specific examples of other emulsifiers are salts between acids, suitably polyvalent acids, such as a polyvalent phosphoric acid, and an imidazoline compound of the formula
[0000]
[0000] wherein R is an alkyl group of 5-21, preferably 7-19 carbon atoms, and n is a number from 0-3; or an amidoamine compound of the formula
[0000]
[0000] wherein one or two of the groups R 1 , R 2 , R 3 , and R 4 are an acyl group of 6-22, preferably 8-20 carbon atoms and the remaining groups R 1 , R 2 , R 3 , and R 4 are lower alkyl groups of 1-4 carbon atoms, preferably methyl, hydroxyethyl, hydroxypropyl or hydrogen, and n is a number from 1 to 4, with the proviso that at least one nitrogen atom is part of an amino group.
[0033] The bitumen-aggregate mix can also contain an additional organic binder, for example latex, selected from the group consisting of SBR, polychloroprene, and natural latex, and mixtures thereof. The latex can be incorporated into the bitumen emulsion or directly into the mix. It may be necessary to use cationic or nonionic grades of latex compatible with the emulsion, as is well known in the art of emulsion formulation. The latex binder may impart desirable properties to the cured mixture including improved durability. The bitumen aggregate mix can also contain other components such as fibres and pigments.
[0034] The invention is further illustrated by the working examples below.
EXAMPLE 1
[0035] In a batchwise reactor acrylonitrile and a tallow alkyl amine were reacted at a temperature of 70-100° C. After the reaction, the obtained aminopropionitrile was hydrogenated in the presence of ammonia and a nickel-containing catalyst. The main product obtained was (tallow alkyl)NH(CH 2 ) 3 NH z , which was then reacted with acrylonitrile and thereafter hydrogenated as described above. The reaction mixture was analyzed by titration of the nitrogen in order to determine the total amount of basic nitrogen and the amounts of tertiary, secondary, and primary nitrogen. The major component was a triamine of the formula (tallow alkyl)NH(CH 2 ) 3 NH(CH 2 ) 3 NH 2 and its total yield was above 80% by weight.
[0036] The primary and secondary nitrogen atoms of the triamine were then methylated by reductive methylation with formaldehyde in the presence of formic acid as the reducing agent. In the process 100 g of the triamine were slowly added at a temperature of 80° C. to an aqueous solution containing 91.5 g of formic acid, 52.3 g of NaOH, and 47.1 g of formaldehyde. After completion of the methylation, the phase containing the methylated triamine was separated from the water by adding an aqueous solution containing 46% by weight of NaOH. The methylation degree of the triamine was controlled by the same method as described above. The yield of the methylated triamine, (tallow alkyl)N(CH 3 )(CH 2 ) 3 N(CH 3 )(CH 2 ) 3 N(CH 3 ) 2 , was found to be about 98% by weight of the starting triamine.
EXAMPLE 2
[0037] The (tallow alkyl)-dipropylene triamine disclosed in Example 1 was further reacted with one equivalent of acrylonitrile, whereupon the obtained nitrile derivative was hydrogenated. The nitrilation step, the hydrogenation step, and the methylation step were performed according to the same principles as described in Example 1. The major reaction product was a tetraamine of the formula (tallow alkyl)-N(CH 3 )[(CH 2 ) 3 N(CH 3 )] 2 (CH 2 ) 3 N(CH 3 ) 2 , and its structure was confirmed by the analyses described above. The total yield was about 80% by weight.
EXAMPLE 3
[0038] Several aqueous bitumen-aggregate mixes were prepared by mixing
a) 8 parts by weight of an aqueous oil-in-water bitumen emulsion containing 5.2 parts by weight of bitumen and an emulsifier in an amount in accordance with Table 1, b) 100 parts by weight of an aggregate of granite, consisting of the following fractions 0-4 mm 44%, 4-8 mm 23%, 8-12 mm 33%, and c) 5 parts by weight of water,
at a temperature of about 20° C. The bitumen used in the emulsion had an acid value of 4 mg KOH/g of bitumen. The emulsifiers used in the preparation were the following.
[0000]
Emulsifiers
Designation
Structure
A
Salt between orthophosphoric acid and the methylated
triamine described in Example 1
B
Salt between orthophosphonic acid and the methylated
tetraamine described in Example 2
C
Salt between orthophosphoric acid and (tallow alkyl)-
N(CH 3 )C 3 H 6 N(CH 3 ) 2
D
Salt between orthophosphoric acid and (tallow alkyl)-
NH(C 3 H 6 NH) 2 C 3 H 6 NH 2
E
Salt between hydrochloric acid and (tallow alkyl)-
NH(C 3 H 6 NH) 2 C 3 H 6 NH 2
F
(Tallow aikyl)N + (CH 3 ) 2 C 3 H 6 N + (CH 3 ) 2 + 2Cl
[0042] The pH of the emulsions was adjusted with orthophosphoric acid or hydrochloric acid to a pH value of 2. After their preparation, the asphalt mixes were spread out on a surface for six hours at 20° C., whereupon the workability of the asphalt mixes was determined according to the Workability Test of Nynäs Bitumen AB, Identification No. FBMASS2.BGu, dated 950621. According to said test, the workability of an asphalt mix was measured as the force needed to form, in a box, an asphalt layer of 50 mm thickness and 140 mm long by 230 mm broad from 20+ kg of the asphalt mix by shearing off the surplus with an aluminium plate moving 140 mm during 14 s. According to this test, an asphalt mix of good workability should have a value lower than 200 N. The results obtained are also shown in Table 1.
[0000]
TABLE 1
Compositions of the mixes and their workability
Emulsifier
Mix No.
Type
Parts by weight
Workability, N
1
A
1.0
78
2
B
1.0
130
3
C
1.0
571
4
D
1.0
586
5
E
0.6
1120
6
F
1.0
1248
[0043] From the results it is evident that the emulsifiers A and B according to the invention impart essentially better workability to the asphalt compositions than the comparison emulsifiers C-F.
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According to the invention, a slow setting bitumen-aggregate mix for cold paving is manufactured by a) preparing a cationic oil-in-water emulsion of bitumen in the presence of an emulsifier containing i) a tertiary polyamine selected from the group consisting of a di(C 2 -C 3 alkylene)triamine, a tri(C 2 -C 3 alkylene)tetraamine, a tetra(C 2 -C 3 alkylene)pentaamine, a penta(C 2 -C 3 alkylene)hexaamine, a hexa(C 2 C 3 alkylene)heptaamine or a mixture thereof, which amine compounds have only tertiary amine groups and contain one or two aliphatic groups with 8-22 carbon atoms, bound to a nitrogen atom, while the remaining nitrogen substituents are methyl groups and ii) an acid present in such an amount that the aqueous emulsion obtains a pH value from 1-6, preferably 1.5-5, and b) mixing the aqueous emulsion obtained with a solid aggregate. The present invention also comprises a tertiary polyamine selected from said group of tertiary polyamines or a salt thereof with an acid, a process for the production of said tertiary amine, as well as the use of the tertiary polyamine salt as an emulsifying or cohesion increasing agent.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application No. 61/012,395, and Provisional Application No. 61/012,346, both filed Dec. 7, 2007, which are herein incorporated by reference for all purposes.
BACKGROUND OF THE INVENTION
The present application is related to method and system for enhancing video and images. In various embodiments, the present invention provide techniques for enhancing color saturation levels in component color spaces, where images (or frames of videos) are stored in terms of luminance and chrominance levels. In certain embodiments, the present invention provides an algorithm for adjusting color saturation of video in real-time playback. But it is to be understood that embodiments of the present invention have wide range of applicability, which can be applied to video processing, imaging processing, image viewing, and others.
Over the last few decades, technologies for media processing and rendering developed rapidly, especially with the advent of the better computer hardware and telecommunication techniques. In today's world of ubiquitous data communications, ranging from Internet to personal mobile devices, people are sharing more and more media content over communication networks everyday.
Network resources are limited, despite the continuous effort by network companies and providers to improve and expand communication network. Meanwhile, content providers and engineers develop various means to improve media output under the constraints of existing hardware. Among others, various types of compression and enhancement techniques have been developed to improve images and video qualities. These techniques have been used for both contents shared over communication networks and contents stored in various types of media, such as DVD, Blu-Ray discs, CDs, tapes, etc. For each type of application, there are one or more specific and different requirements for the image/video quality. For example, many entertainment-related applications need the playback system to provide better color performance in terms of saturation and hue for the image/video viewers so that the video appear to be more colorful and vivid. This example is more so for low quality video (such as web cam and/or “youtube” videos), where colors are usually dull and uninteresting.
Saturation adjustment is a useful tool in improving video and/or image qualities. By adjusting color saturation, image and/or video can be made to look vivid or muted. There are various conventional techniques exist for saturation adjustment. Unfortunately, these conventional techniques are inadequate for various applications.
Therefore, improved methods and systems for color enhancement are desired.
BRIEF SUMMARY OF THE INVENTION
The present application is related to method and system for enhancing video and images. In various embodiments, the present invention provide techniques for enhancing color saturation levels in component color spaces, where images (or frames of videos) are stored in terms of one luminance and two chrominance levels. In certain embodiments, the present invention provides an algorithm for adjusting color saturation of video in real-time playback. But it is to be understood that embodiments of the present invention have wide range of applicability, which can be applied to video processing, imaging processing, image viewing, and others.
According to an embodiment the present invention provides a method for enhancing color saturation. The method includes providing a color image, the color image being defined by a component color space, the component color space being characterized by a luminance component and two or more chrominance components, the color image including a plurality of pixels, the plurality of pixels including a first pixel being characterized at least by a luminance value, a first chrominance value, and a second chrominance value. The method also includes processing the first chrominance value and the second chrominance value, the first chrominance value and the second chrominance value being characterized by a ratio. The method further includes determining a saturation level using based on the first chrominance value and the second chrominance value. Moreover, the method includes providing a factor for adjusting the first chrominance value and the second chrominance value, the factor being based on the saturation level. Furthermore, the method includes adjusting the first chrominance value and the second chrominance value using the factor, the adjusted first chrominance value and the second chrominance value being maintaining the ratio.
According to another embodiment, the present invention provides a method for enhancing color saturation. The method includes providing a color image, the color image being defined by a component color space, the color image including a plurality of pixels, the plurality of pixels including a first pixel being characterized at least by a luminance value, a first chrominance value, and a second chrominance value. The method also includes processing the first chrominance value and the second chrominance value. Additionally, the method includes determining a saturation level using based on the first chrominance value and the second chrominance value. Furthermore, the method includes providing a factor for adjusting the first chrominance value and the second chrominance value. In addition, the method includes subtracting the first chrominance value and the second chrominance value by an offset value. Moreover, the method includes multiplying the first chrominance value and the second chrominance value by the factor.
According to yet another embodiment, the method includes a method for enhancing color saturation of video in real time. The method includes providing a digital video, the digital video being defined by a component color space. The method also includes processing a frame of the digital video, the frame including a plurality pixels, the plurality of pixels including a first pixel being characterized at least by a luminance value, a first chrominance value, and a second chrominance value. Also, the method includes processing the first chrominance value and the second chrominance value. Moreover, the method includes determining a ratio for the first chrominance value and the second chrominance value. Additionally, the method includes providing a factor for adjusting the first chrominance value and the second chrominance value, the factor being based on the saturation level. In addition, the method includes multiplying the first chrominance value and the second chrominance value by the factor, the multiplied first chrominance value and the second chrominance value being characterized by a same ratio. Furthermore, the method includes outputting the frame within a predetermined time.
According to yet another embodiment, the present invention provides a method for enhancing color saturation. The method includes providing a color image, the color image being defined by a component color space, the component color space being characterized by a luminance component and two chrominance components, the color image including a plurality of pixels, the plurality of pixels including a first pixel being characterized at least by a luminance value, a first chrominance value, and a second chrominance value, first and second chrominance values having a range of between 0 and 255. The method also includes providing a first chrominance value adjustment table, the chrominance value adjustment table including at least 256 values, the 256 values being predetermined based on at least a first parameter, the 256 values being corresponding the range of chrominance values. The method also includes determining a third chrominance value based on the first chrominance value using the first chrominance value adjustment table. Also, the method includes determining a fourth chrominance value based on the second chrominance value using the first chrominance value adjustment table.
It is to be appreciated that embodiments of the present invention provide numerous advantages over conventional techniques. Among others, various techniques according to the present invention are applicable in component color spaces, such as YUV, YCbCr, YPbPr, and YIC spaces, thereby eliminating the needs of conversion between different color spaces and improving efficiency. In addition, it is also to be appreciated that embodiments of the present invention preserve continuity of color saturation level over adjacent pixels on both local level and global level, thereby keeping the whole image consistent. In various embodiments, the present invention takes existing color and/or saturation level into consideration to fine tune the amount of color adjustment being applied. Furthermore, various techniques according to the present invention can be easily implemented in conjunction with conventional systems.
Various additional objects, features and advantages of the present invention can be more fully appreciated with reference to the detailed description and accompanying drawings that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1( a )- 1 ( c ) are simplified diagrams illustrating the RGB color space.
FIG. 2 is a simplified diagram illustrating color representation in YCbCr color space.
FIG. 3 is a simplified diagram illustrating color adjustment technique according to an embodiment of the present invention.
FIG. 4 is a simplified diagram illustrating a method for determining the amount of adjustment to be applied to color saturation level.
FIG. 5 is a simplified diagram illustrating the use of look up table.
DETAILED DESCRIPTION OF THE INVENTION
The present application is related to method and system for enhancing video and images. In various embodiments, the present invention provide techniques for enhancing color saturation levels in component color spaces, where images (or frames of videos) are stored in terms of one luminance and multiple chrominance levels. In certain embodiments, the present invention provides an algorithm for adjusting color saturation of video in real-time playback. But it is to be understood that embodiments of the present invention have wide range of applicability, which can be applied to video processing, imaging processing, image viewing, and others.
As explained above, conventional techniques for color adjustment, especially the enhancement of color saturation, are inadequate for many of today's applications. These conventional techniques often yield unsatisfactory results. In addition, they are often slow and inefficient for various real-time applications, such as video playback, online playback, etc. In addition, these conventional techniques often cause artificial and undesirable change of the hue in colors.
In most conventional techniques, color adjustments and/or enhancements are performed in RGB color space, which is based on the RGB color model. Any color is defined by the three primary colors: red, green, and blue. Today, the RGB color space is used in a variety of applications, ranging from cameras, television, camcorders, and others. Many color enhancement techniques are designed for the RGB color space, since RGB color space is focused on color, and enhancing color in a color space seems intuitive and straightforward.
FIGS. 1( a )- 1 ( c ) are simplified diagrams illustrating the RGB color space. As shown in FIG. 1( a ), the RGB cube includes three axes, which respectively indicate the amount red, blue, and green. A color can be defined as position with the RGB cube. For example, a color shown in FIG. 1( c ) is defined by a position where R equals to 80, G equals to 200, and B equals to 130.
In a conventional technique for adjusting color saturation, a color pixel is processed and associated with a predetermined “color zone”. The color pixel is then modified within this color zone. The color zone allows the hue of the color pixel to be reasonable preserved while saturation of the color pixel to be increased. For example, a image full of color pixels processed using this conventional technique can look more saturated while overall color scheme is somewhat preserved. However, there are various drawbacks with this type of technique.
The “color zone” technique described above often produces undesirable discontinuity within an image. Sometimes, two or more adjacent color pixels, though having substantially similar colors, may be associated with different colors zones. For each pixel, the saturation enhancement is performed using their respective color zones. As a result, the two processed adjacent pixels can be more different from each other in color as a result of saturation adjustment. Often, such differences between adjacent pixels become undesirable artifacts visible on processed images or videos. To reduce this problem, it is often necessary to interpolate and smooth adjacent pixels during the color adjustment process, thereby increasing the computational cost thereof.
In addition to the poor image qualities, the conventional technique as described is inefficient. Usually, it takes many computation steps to determine the color zone for a pixel. If interpolating adjacent pixels is requirement to preserve color continuity and reduce artifacts, additional computations have to be performed.
Despite various drawbacks, various conventional RGB-based techniques are satisfactory for certain applications where RGB color space is used. However, these techniques are inefficient for processing videos and/or images that are encoded in other color spaces, such as YUV color space, YCbCr color space, YIQ color space, YPbPr space, and others. In these types of component color spaces, colors are defined in by a luminance value and two chrominance values. As an example, in YUV color space, Y represent the luminance (or brightness) value, while the U and V components represent chrominance (or color) values. Similarly, in a YCbCr color space, Y represent the luminance (or brightness) value, while the Cb and Cr components represent chrominance (or color) values. These types of component color space are widely used in video applications. For example, the YUV color model is used in the PAL, NTSC, and SECAM composite color video standards. Similarly, the YCbCr color space is widely adopted by various types of video and imaging formats, such as MPEG, H.262, JPEG format, HDTV format (e.g., ITU-R BT.709 standard), and others.
Processing these types of videos using the conventional RGB-based techniques require converting the videos to the RGB color space first and then converting them back. The conversion processes themselves are computationally intensive and inefficient. Therefore, it is appreciated that in various embodiments, the present invention allows color adjustment and/or enhancement to be performed in component color spaces, such as YUV color space, YCbCr color space, YIQ color space, and YPbPr space, without the need of converting to the RGB color space first.
FIG. 2 is a simplified diagram illustrating color representation in YCbCr color space. In a YCbCr color space, the Y, representing brightness level, is an 8-bit value ranging from 0 to 255. The Cb and Cr, representing the chrominance levels, are each an 8-bit value which usually represent values from −128 to +127. Since in digital representation, the 8-bit value is usually an unsigned (i.e., non-negative) integer, the value can be from 0 to 255. In this case, an offset of −128 is needed to obtain the actual color value of Cb and Cr for the purpose of color manipulation. For example, a Cb value that is stored using unsigned integer format needs to subtract 128. A value of 200 in the unsigned integer format is actually 72 on the color representation graph illustrated in FIG. 2 . A value of 10 in the unsigned integer format is actually −118 on the color representation graph.
As shown in FIG. 2 , color is defined by the amount of Cr and Cb components. The entire color spectrum in the Cr and Cb representation is contained in the hexagon shown in FIG. 2 . For example, each of the vertex of the hexagon is associated with a specific color: red, magenta, blue, cyan, green, and yellow. The origin of the Cr/Cb graph is the white point, where there are no color components. On the other hand, the closer it is to the edge of the edges of the hexagon, the more vivid or saturated a color appears.
As an example, the following texts of the specification illustrates embodiments the color adjustment techniques performed in YCbCr color space. It is to be understood that various embodiment of the present can be used in other color spaces as well, such as YUV color space, YIQ color space, YPbPr space, and others.
FIG. 3 is a simplified diagram illustrating color adjustment technique according to an embodiment of the present invention. This diagram is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications.
According to embodiment of the invention, the saturation of any point P(Cb, Cr) in the YCbCr space is the distance ∥PW∥ between P and the white point, Depending on the specific application, the distance ∥PW∥ may be calculated in a variety of ways. For example, the distance ∥PW∥ may be calculated as a Euclidean distance, a Manhattan distance, a Maximum distance (∥PW∥=max (Cb, Cr)), etc. By increasing the distance ∥PW∥, the color saturation for the point P(Cb, Cr) will be increased. Conversely, by decreasing the distance ∥PW∥, the color saturation for the point P(Cb, Cr) will be decreased.
It is to be appreciated that embodiments of the present invention adjust the color saturation of without changing the color hue, thereby preserving the color scheme of the original images and/or videos. The hue of the color in the YCbCr space, in various embodiment of the invention, is defined by the angle between directional line {right arrow over (WP)} (i.e., from the white point to the point P) and Cb axis. To increase the amount of saturation for the point P, the P is moved along the direction line {right arrow over (WP)} toward the border of YCbCr hexagon color space. On other hand, to decrease the amount of saturation for the point P, the P is moved along the direction line {right arrow over (WP)} toward the white point of YCbCr hexagon color space.
As explained above, the technique described above is also applicable to other component color spaces, wherein a pixel is presented by a luminance value and two chrominance values. These color spaces include, but not limited to YUV color space, YIQ color space, and YPbPr space. For example, to adjust to color for a point on the YUV color space, the distance ∥PW∥ from white point is derived from U and V values, and the hue angle is between the direction line {right arrow over (WP)} and the U axis. Similarly, to adjust to color for a point on the YPbPr color space, the distance ∥PW∥ from white point is derived from Pb and Pr values, and the hue angle is between the direction line WP and the Pb axis.
To increase the amount of saturation for the point P, the point P is to P′ along the direction line {right arrow over (WP)}, thereby preserving the same angle between the directional line {right arrow over (WP)} and Cb axis. Since the point P′ is closer to the saturation boundary, the point P′ has a higher saturation than the point P. As an illustration, the color adjustment performed according to embodiments of the present invention can be expressed by the following equation:
∥ P′W∥=β*∥PW ∥, where β is non-negative (Equation 1)
Typically, the value of β is close to 1. By using a β with a value greater than 1, the color saturation of the point P increases. By using a β with a value less than 1, the color saturation of the point P decreases. In an extreme case where β equals to zero, the color information for the point P is disregarded. Typically, to avoid over-adjustment of color saturation, which may cause loss in color fidelity, the value of β is close to 1. For example, to increase saturation, the β value could be 1.1 or 1.2.
To adjust color saturation level based on Equation 1, the value of Cb and Cr are computed using the following equations:
( Cb′− 128)=β*( Cb− 128) (Equation 2A)
( Cr′− 128)=β*( Cr− 128) Equation 2B)
In Equations 2A and 2B, the number 128 provides an offset for the Cb and Cr value stored in 8-bit unsigned integer format. Depending on the specific format in which the chrominance values are stored, the offset varies. The goal of the offset is to ensure that 0 in chrominance values represent the white point. For example, in a 4-bit unsigned integer format, the offset is 2 4 divide by 2, which equals to 8. In a different scenario, where the white point is already represented by the value 0 for chrominance values, the offset is not needed (i.e., offset equals to 0).
Actually obtain the chrominance values after the adjustment, the following equations can be used:
Cb′= 128+β( Cb− 128) (Equation 3A)
Cr′= 128+β*( Cr− 128) (Equation 3B)
Equation 3A is provided to calculate the value of Cb′, which is the chrominance value Cb after color saturation adjustment is performed. For example, Equation 3A is derived from Equation 2A. Similarly, Equation 3B is provided to calculate the value of Cr′, which is the chrominance value Cr after color saturation adjustment is performed. For example, Equation 3B is derived from Equation 2B. During the process of color enhancement, the luminance value is not changed.
As an example, a pixel P is represent by 24-bit value. The 24-bit includes an 8-bit luminance value, two 8-bit chrominance values. Using the color adjustment technique described above, the luminance value is not changed. The chrominance values are modify using the technique described above.
Depending on the application, the β value may be constant or variable, and can be set in various ways. In a specific embodiment, the β value is determining according to a set of constant preset values. Based on user input (e.g., vivid level +1, −1, etc.), the β value is selected from the set of values. In another embodiment, the β value is a constant value that is applied to all color pixels. In other embodiments, the β is calculated in different ways as described below.
In a specific embodiment, the value of β, which translates to the amount of saturation applied, depends on the amount saturation of the point P before any adjustment is applied. FIG. 4 is a simplified diagram illustrating a method for determining the amount of adjustment to be applied to color saturation level. This diagram is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. As an example, the graph in FIG. 4 is used to enhance (or increase) color saturation.
As shown in FIG. 4 , the β value largely depends on the value of ∥PW∥which can be calculated using the chrominance values. When the value of ∥PW∥ is close to zero, the color is close to grey. For example, when the color is close to grey, it falls into a grey zone, in which the saturation is near zero. In such case, little or no color adjustment should be applied to the color pixel. For example, increasing saturation of a grey pixel sometimes produces undesirable greenish artifact. As shown, the β value is close or equal to 1 when the color is within a predetermined grey zone. Since the β value is close or equal to 1, minimal or zero color adjustment is performed.
On the other hand, if the value of ∥PW∥ is close the maximum, it means that the color is already close to saturation before adjustment. To avoid over-saturation and/or artifacts (e.g., clipping) thereof, the amount of adjustment applied to pixel is very little or none. As shown, the β value is close or equal to 1 when the value of ∥P∥ is close to the maximum saturation level. Since the β value is close or equal to 1, minimal or zero color adjustment is performed.
As shown in FIG. 4 , the β value, which translates to the amount of color adjustment, is a function of the ∥PW∥ value. Depending on the application, the function may be different to suit the specific needs for color adjustment. For example, the curvature shown in FIG. 4 may be increased to bring out more color saturation, or to decreased to bring out less color saturation. In addition, the β value may also determined by other values, such as the Cb value and/or Cr value.
The existing saturation level of a color pixel is not the only factor in determining the β value. In certain embodiments, the color saturation levels of adjacent pixels are also considered to preserve the color continuity and fidelity. In certain embodiments, the β value is determined so that the color adjustment among neighboring pixels are monotonic incremental. That is, if one pixel has a relatively higher saturation level compared different pixel, this one pixel retains the relatively higher saturation level than the other pixel after color adjustments are performed, and vice versa.
It is to be understood that various embodiments of the present invention are flexibly implemented. The β value may be determined using any of techniques described above, or the combination thereof.
In an alternative embodiment, the present invention provides a simplified method in which amount of computation is reduced. This method lowers the priority of preserving the hue values and accepting the insignificant hue change. The new point P′ in color space is calculated using the following equations:
Cb′= 128+β b *( Cb− 128); where β b >1 and β b =F 1 ( Cb ) (Equation 4A)
Cr′= 128+β r *( Cr− 128); where β r >1, and β r =F 2 ( Cr ) (Equation 4B)
For Equations 4A and 4B, F 1 , F 2 , ad F are functions to compute β b and β r . To further reduce computational costs, the values of β b and β r are set as β b =β r =F(C). It is to be appreciated other computation methods may be derived from the above equations.
In the description of the embodiments above, the adjustment are performed one color pixel at a time. But it is to be understood that the invention has a broad range of applicability. For example, in the 4:2:2 Y′CbCr space, chrominance values are sampled at half of the rate of the luminance value. In this case, a pair of chrominance values is used to represent the color of two horizontal pixels. In this scenario, the color adjustment is performed for this pair of chrominance values. Similarly, such approach can used in other type sampling methods, such as 8:4:4, 4:4:2, 4:2:1, 4:1:1, 4:2:0, and others, where color adjustment is performed for a pair of chrominance values.
In an alternative embodiment, a lookup table is used to provided the value in lieu of performing computations. FIG. 5 is a simplified diagram illustrating the use of look up table. As shown in FIG. 5 , the graph illustrates the relationship between a chrominance values before adjustment (denoted C) and modified chrominance values (denoted C′). As can be seen from the graph, the chrominance values have a possible range of between 0 and 255. Accordingly, for each of the 255 chrominance values, the graph contains a corresponding modified chrominance value. Depending on the application, the modified chrominance value can be determined in many ways. For example, the modified chrominance values are determined using the process describe above (e.g., using Equations 3A and 3B). Once calculated, the modified chrominance values are stored in a table, which may be stored in a data structure. For example, the modified chrominance values are stored in an optimized manner for quick access.
In a specific embodiment, the modified chrominance value is stored in an array structure with a fixed size of 256. For example, to obtain a modified chrominance value from an original chrominance value, it is only necessary to access the array structure. For example, the modified chrominance value is an array C′=a[i], where i is between 0 and 255. To obtain a modified chrominance value based on a chrominance value, it may be as simple obtaining C′=a[C]. It is to be appreciated that by using the table as opposed to computation, the amount of time and resource for enhancing color saturation is improved.
Depending on the application, one or more tables may be used. In a specific embodiment, there are two chrominance value adjustment tables for Cb and Cr respectively. In another embodiments, multiple chrominance value adjustments table are provided to allow user to choose the amount of color enhancement to be performed.
As shown in FIG. 5 , the β value largely depends on the value ∥PW∥, which can be calculated using the chrominance values. In an alternative embodiment, the chrominance value adjustment is independently based on either Cb and Cr value, and the value ∥PW∥ is not used for the computation of the modified chrominance value. As an example, Cb has a value of 129, and Cr has a value of 240, as they are stored in 8 bits unsigned format. As explained above, an offset of 128 is used. After taking the offset value of 128 into consideration, the new Cb value is 1 and the Cr value is 112. That means Cb component is near the white point and the Cr value is near color saturation. The Cb value is modified by multiplying 1 by a factor of 1.6, while the Cr value is modifying by a factor of 1. The factor for multiplying Cb and Cr is totally based on the value of Cb and Cr after taking offset value into consideration. That, is one of the chrominance value is near white point, the factor is high. Chrominance value is near saturation, the factor is low. Under this scheme, the chrominance value is increased by a relative large amount for chrominance component that is nearly white, and the chrominance value is increased by a relative small amount (or not increased at all) for chrominance component that is nearly saturation. For example, when the chrominance value (after taking the offset of 128 into consideration) has an absolute value of less than 20, the factor of adjustment is 1.6; when the chrominance value has an absolute value of between 20 and 40, the factor of adjustment is 1.5, and when the chrominance value has an absolute value of higher than 110, the factor of adjustment is 1. As an example, FIG. 5 is a simplified graph illustrating the multiplying factor values to be used based on the chrominance value. This diagram is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications.
In applications involving videos, techniques according to the present invention are performed for each frame of the video.
The embodiments above can be implemented into various video and image systems. For example, these embodiments may be implemented as software algorithms that are executed when displaying, editing, and/or transmitting videos and images. In certain embodiments, techniques according to the present invention may be hardwired to image and/or video processing chips. It is to be appreciated that many types of image and video systems can benefit from embodiments of the present invention. For example, these system include, but not limited to, personal computer, television, media player, mobile phone, network device, etc.
Although specific embodiments of the present invention have been described, it will be understood by those of skill in the art that there are other embodiments that are equivalent to the described embodiments. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrated embodiments, but only by the scope of the appended claims.
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Method and system for enhancing color saturation. According to an embodiment the present invention provides a method for enhancing color saturation. The method includes providing a color image characterized by a luminance component and two chrominance components, the color image including a plurality of pixels, the plurality of pixels including a first pixel being characterized at least by a luminance value, a first chrominance value, and a second chrominance value. The method also includes processing the first chrominance value and the second chrominance value. The method further includes determining a saturation level using based on the first chrominance value and the second chrominance value. Moreover, the method includes providing a factor for adjusting the first chrominance value and the second chrominance value, the factor being based on the saturation level. Furthermore, the method includes adjusting the first chrominance value and the second chrominance value using the factor.
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This application claims the benefit of U.S. Provisional Application No. 60/178,980, filed Jan. 28, 2000.
BACKGROUND OF THE INVENTION
This invention is a medical device and relates generally to the field of punch devices used in performing anastomosis (the joining of a hollow or tubular organ to another hollow or tubular organ), and in particular such devices used in the surgical joining of a vein graft to the aortic wall, where the punch device is used to create the hole in the aortic wall.
In coronary bypass surgery, a blocked segment of the coronary artery is bypassed by attaching a vein graft to the aorta above the blocked point and to the artery downstream of the blocked point, such that blood flow is routed around the blockage through the vein graft. In a common technique used to attach the graft, a hole is created in the aortic wall by first creating a small slit using a scalpel. The cutting disk of a punch device is then inserted through the slit. The cutting disk is mounted onto a thin shaft, which is coaxially received by a tubular sleeve member, the end of which is provided with an annular cutting edge or rim. With the aortic wall between the disk and the sleeve, either the disk is retracted into the sleeve or the sleeve is advanced beyond the disk. This operation cuts a circular opening in the aortic wall, and the plug cut from the wall is entrapped within the sleeve and disk. The punch device is then removed and the surgeon proceeds with the anastomotic procedure.
It is necessary to temporarily occlude the opening in the aortic wall in some manner after removal of the plug to prevent excessive loss of blood during the anastomotic procedure. The most commonly employed method is to apply a C-shaped surgical clamp to the side of the aortic wall at the proposed site of the anastomosis prior to cutting the aorta and introducing the punch. The clamp compresses only a portion of the aorta, allowing continued blood flow past the clamped area. This technique can be problematic in that application of the clamp may cause damage to the aorta or release plaque fragments or atheromatous debris into the blood stream when the clamp is released.
One alternative technique for blocking blood flow through the hole created in the aortic wall by a combination punch device is shown in U.S. Pat. No. 5,944,730 of Nobles et al. The Nobles et al. device, as described in the second embodiment of the disclosure, is a grossly elongated instrument having an occluding inverting member mounted onto the distal end of a long, slender flexible tube, an inverter handle assembly, and an intermediately disposed punch assembly. The punch assembly is joined to the inverter handle assembly in a disconnectable fashion, such that the punch assembly is detached from the inverter handle assembly and slid distally along the flexible tube to remove the plug from the aortic wall, after which it is translated proximally and rejoined to the inverter handle assembly. The inverter handle assembly is then manipulated to cause the inverting member to fold onto itself into a conical configuration and the entire device is pulled in the proximal direction to seal the aortic wall. Each end of the inverting member must be attached to a different elongated tubular member which are slidably movable in the axial direction relative to each other. The provision of separable punch and inverter handle assemblies, the elongated flexible tube on which is mounted the occluding member, and the overly complicated design of the occluding member results in an awkward instrument of excessive length which is difficult to operate in an efficient and straightforward manner. Additionally, there is no structure to block blood flow through the hole in the aortic wall during the time period while the punch assembly is being withdrawn and rejoined to the inverter handle assembly prior to expansion of the inverting member and retraction of the apparatus.
It is an object of this invention to provide an anastomosis punch device for creating a hole in the aortic wall, and method of use for same, which has an occluding structure to prevent blood from exiting the hole created in the aortic wall during attachment of the vein graft, where the device comprises an elastic dam membrane having circumferentially spaced longitudinal ribs, where the ribs may be spread to open the membrane into a conical configuration in an umbrella-like manner to surround the hole, then collapsed for withdrawal after the vein has been partially secured, where the dam is affixed to the shaft of the cutting sleeve immediately proximal to the cutting sleeve, where an occluding body is provided to block blood flow through the hole created in the aortic hole prior to expansion of the elastic dam membrane, such that the punch device is a compact instrument which is easily manipulated by the surgeon.
SUMMARY OF THE INVENTION
The invention comprises an anastomosis punch device, and method of using same, for creating a circular hole in the aortic wall, where the device also segregates the hole from the blood flow path such that no blood is lost through the hole during attachment of the vein graft. The invention is a compact hand-held punch comprising an elongated housing to be gripped by the surgeon, the housing retaining in a coaxially aligned manner a distally extended punch head, a cutting sleeve having a distal cutting rim which cuts a circular plug in cooperation with the punch head, an expandable, umbrella-like, flexible dam formed of an elastic tubular material and adjoined to the sleeve in a manner which allows it to be deployed radially outward with the enlarged open rim facing the proximal direction, and a deployment ram movable axially relative to the dam to spread open the dam. The surgeon inserts the punch head through the aortic wall, then advances the cutting sleeve against and over the punch head to remove a circular plug of aortic wall, with the plug being retained within a chamber defined by the cutting sleeve and the punch head and the cutting sleeve locked in the advanced position. The entire device is then advanced a short distance through the hole in the aortic wall such that the entire flexible dam member is positioned internally to the aortic wall with a portion of the ram member occluding the hole in the aortic wall to prevent blood loss. The ram is then advanced relative to the dam, causing the proximal end of the dam to spread outwardly to form a cone shape, and the ram is locked in position. The rim of the expanded dam is then drawn against the interior wall of the aorta, thus forming a conical dam about the hole. The vein graft is then attached to the aortic wall at the hole using known suturing techniques while the device remains in place. Once the vein is sufficiently attached to the aortic wall in loose manner, the ram is retracted relative to the dam, allowing the dam to collapse into the passive configuration with minimal diameter because of the elastic nature of the membrane. The entire device is then withdrawn between the sutures and completely out of the aorta, with the sutures then quickly tightened to connect the vein graft to the aorta.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an external side view of the device.
FIG. 2 is a cross-sectional view showing the punch head of the device as inserted into the aortic wall, taken along line II—II of FIG. 1 .
FIG. 3 is a cross-sectional view similar to FIG. 2, showing the plug removed from the aortic wall and the device advanced into the aorta.
FIG. 4 is a partial cross-sectional view similar to FIG. 3, showing the ram advanced and the dam deployed against the aortic wall.
FIG. 5 is a partial view of the device similar to FIG. 4, showing the ram advanced and the dam deployed against the aortic wall.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the drawings, the invention will now be described in detail with regard for the best mode and the preferred embodiment.
As shown generally in FIG. 1, the invention is an anastomosis punch device comprising a generally elongated, tubular instrument housing 10 , a punch assembly 30 , a cutting sleeve assembly 50 , an elastic dam assembly 70 and a deployment ram assembly 90 . The device is configured as an integral apparatus of compact design so as to be easily gripped and manipulated by surgeon. For example, a device having a housing 10 approximately 9 cm in length and approximately 8 mm in diameter, with the distal portion of the punch assembly 30 extending only about 4 cm from the distal end 12 of the housing 10 , is representative of a very suitable size. With reference also to FIG. 2, the elongated instrument housing 10 is shown to comprise a proximal end 11 and a distal end 12 , where the distal end 12 is the end positioned against the aortic wall 100 during use. For purposes of this disclosure, references to the distal direction or a distal element shall mean the direction or element toward the aortic wall 100 with the device in use, while references to the proximal direction shall means the opposite direction, i.e., external to away from the aortic wall 100 . A pair of laterally extending finger grips 18 are externally mounted on the instrument housing 10 , preferably approximately 4 cm from the proximal end 11 of the instrument housing 10 . A first coaxial cylindrical bore 13 extends from the proximal end 11 and meets a second coaxial cylindrical bore 14 within the body of instrument housing 10 , where the second bore 14 extends from the distal end 12 and is larger than the first bore 13 . Cutting sleeve locking means 20 , comprising as shown a transverse bore 15 extending into the first bore 13 , is provided near the proximal end 11 to receive a sleeve locking pin 16 , which is used to secure the cutting sleeve assembly 50 in the advanced position relative to the instrument housing 10 , as shown in FIG. 3 . Equivalent constructions for cutting sleeve locking means 20 may be utilized as well. A longitudinally extending sleeve guide slot or pair of slots 17 is provided in first bore 13 , the sleeve guide slot 17 receiving the guide tabs 59 mounted onto the tubular shaft 52 of the cutting sleeve assembly 50 to prevent rotation of the cutting sleeve assembly 50 within the instrument housing 10 to maintain proper alignment between the transverse bore 15 and a pin receiving aperture 58 located in the tubular shaft 52 . A longitudinally extending ram guide slot 19 is provided adjacent or toward the distal end 12 of the instrument housing 10 to provide a channel for controlled movement of the handle 94 of the deployment ram assembly 90 in either axial direction.
Means 60 to create a circular opening 103 in the aortic wall 100 comprise in combination punch assembly 30 and cutting sleeve assembly 50 . Punch assembly 30 is mounted coaxially within instrument housing 10 with a portion extending from the distal end 12 of the instrument housing 10 . Punch assembly 30 comprises a punch head 31 mounted onto a shaft 33 , with the shaft 33 fixed within the instrument housing 10 by detent member 34 . The punch head 31 is a conical or bladed member with a sharp cutting edge or point such that relatively easy penetration can be attained through the aortic wall 100 by direct pressure on the exterior side 102 of the aortic wall 100 . The punch head 31 has an annular rim or disk member 32 on its proximal side, preferably about 3 to 6 mm in diameter, with the edge of the disk 32 having a relatively sharp lip. The outer diameter of the rim 32 is sized to correspond to the internal diameter of the annular cutting rim 55 and cutting sleeve 54 of the cutting sleeve assembly 50 , the outer diameter of disk 32 being only slightly smaller than the internal diameter of cutting rim 55 and cutting sleeve 54 , such that the cutting rim 55 and cutting sleeve 54 can be advanced over the disk 32 to produce a cutting action to remove a circular plug 104 from the aortic wall 100 , as shown in FIG. 3 .
Cutting sleeve assembly 50 is coaxially positioned within instrument housing 10 , fitting within first bore 13 such that sliding movement of the cutting sleeve assembly 50 relative to the instrument housing 10 and punch assembly 30 in the axial direction is possible. Cutting sleeve assembly 50 comprises a tubular shaft 52 which extends from both the distal end 12 and the proximal end 11 of the instrument housing 10 . A flange handle or button 51 is mounted onto the proximal end of the tubular shaft 52 , allowing the cutting sleeve assembly 50 to be advanced by pressure from the surgeon's thumb or palm. A spring member 57 is mounted between the proximal end 11 of the instrument housing 10 and the button 51 , and biases the cutting sleeve assembly 50 in the retracted proximal direction until sufficient pressure is applied to advance it in the distal direction. The tubular shaft 52 defines a coaxial bore 53 which snugly receives the shaft 33 of the punch assembly 30 . A pin receiving aperture 58 is positioned toward the proximal end of the tubular shaft 52 , sized to receive sleeve locking pin 16 when the sleeve cutting assembly 50 is advanced, as shown in FIG. 3 . One or more longitudinally extending guide tabs 59 are provided on the exterior of tubular shaft 52 , the guide tabs 59 being received by sleeve guide slots 17 to preclude relative rotation of the cutting sleeve assembly 50 and the instrument housing 10 . Longitudinal slots 61 are provided on the tubular shaft 52 to allow axial movement of the tubular shaft 52 past the punch detent member 53 .
The distal end of the cutting sleeve assembly 50 comprises a tubular cutting sleeve 54 mounted onto the end of tubular shaft 52 , the cutting sleeve 54 extending radially outward to have both a larger internal diameter than the internal diameter of bore 53 , in order to define a chamber 56 which receives both the disk 32 and punch head 31 of the punch assembly 30 , as well as the plug 104 which is removed from the aortic wall 100 , and to have a larger external diameter than the external diameter of tubular shaft 52 . The distal end of the cutting sleeve 54 is beveled or sharpened to provide an annular cutting rim 55 . The size and configuration of the cutting rim 55 and sleeve 54 are such that when they are advanced against and over the punch disk 32 of the punch head 31 , a shearing or cutting action is effected.
Affixed immediately to the proximal side of cutting sleeve 54 on tubular shaft 52 is the elastic dam assembly 70 , the means for occluding blood flow through the opening 103 in the aortic wall 100 . Elastic dam assembly 70 comprises a tubular elastic membrane or sheet material 72 impermeable to blood, preferably formed of a polymeric material, which in the passive, non-stretched state has a generally cylindrical or a very tight conical configuration of minimal diameter snugly encircling the tubular shaft 52 . The membrane 72 is mounted onto, is formed integrally with, or encases a plurality of relatively rigid, generally linear struts or rib members 73 , generally aligned in the axial or longitudinal direction and evenly spaced in the circumferential direction. The distal end 75 of the elastic membrane 72 is securely attached to or affixed around the tubular shaft 52 by fixation means or ring member 71 , while the proximal end 76 of the membrane 72 is non-attached to any portion of the cutting sleeve assembly 50 and defines a sealing rim 74 , which may be formed in a beaded or thickened configuration to provide a better seal against the interior side 101 of the aortic wall 100 . The membrane 72 is mounted such that it may be flared outwardly in an umbrella-like fashion into a conical active configuration by advancement of the deployment ram assembly 90 toward the fixed distal end 75 and against the ribs 73 , with the ribs 73 being pushed away from the tubular shaft 52 at an acute angle to stretch, support and extend the elastic membrane 72 , and with the expanded sealing rim 74 thus presenting a relatively large circumference, as shown in FIGS. 4 and 5. When the deployment ram assembly 90 is retracted to remove the pressure against the rib members 73 , the elasticity of the membrane 72 causes it to retract into the passive cylindrical configuration of minimal diameter tightly encircling the tubular shaft 52 .
The means to deploy or expand the elastic membrane 72 , deployment ram assembly 90 , is coaxially mounted about the cutting sleeve tubular shaft 52 , and comprises a tubular shaft 93 connected at its proximal end to a transversely extending handle 94 , which is positioned within ram guide slot 19 of instrument housing 10 , such that the ram assembly 90 is movable in the axial direction relative to the housing 10 . The distal portion of the deployment ram assembly 90 extends out of the instrument housing 10 and comprises an occluding body 92 of cylindrical shape, the occluding body 92 having a beveled, curved or cone-shaped head or distal end 91 of greater outer diameter than the tubular shaft 52 . The distal portion of the beveled head 91 of the occluding body 92 fits within the sealing rim 74 of the elastic dam assembly 70 in its passive condition when the deployment ram assembly 90 is advanced toward the fixation ring 71 , such that its movement in the distal direction results in it being positioned internally within the tubular elastic membrane 72 in order to effect expansion of the membrane 72 as it is advanced. The outer diameter and angle of the beveled head 91 , as well as the distance of travel relative to the dam assembly 70 , is such that the membrane 72 is significantly expanded when the ram assembly 90 is fully advanced, with the sealing rim 74 presenting a relatively large circumference to abut the internal side 101 of the aortic wall 100 sufficient distance from the hole 103 to provide room for the surgeon to apply the sutures. Additionally, the outer diameters of the cutting sleeve 54 and the occluding body 92 are substantially equal, such that the occluding body 92 serves to completely fill and block the hole 103 in the aortic wall 100 created by the cutting sleeve 54 , until the elastic membrane 72 is deployed to block blood flow through the hole 103 . The length of the occluding body 92 is preferably less than the axial length of the expanded membrane 72 , such that with the membrane 72 fully expanded and the sealing rim 74 pulled against the internal side 101 of the aortic wall 100 , the occluding body 92 is positioned beyond the aortic wall 100 and no longer fills the hole 103 , the proximal end of the occluding body 92 being disposed distally to the sealing rim 74 of the membrane 72 , thereby providing room for the surgeon to work at the attachment site. Means to lock the deployment ram assembly 90 in the advanced position are provided, and as shown comprises an annular locking collar 95 having of collar slot 96 of sufficient width to allow passage of the ram handle 94 from one side to the other. The locking collar 95 is positioned in an annular collar channel 97 located on the instrument housing 10 such that the collar 96 may be rotated relative to the housing 10 . With the collar slot 96 aligned with the ram guide slot 19 , as shown in FIGS. 1, 2 and 3 , the ram assembly 90 may be advanced to the deployment position, whereupon the locking collar 95 is rotated such that the collar slot 96 is no longer aligned with the ram guide slot 19 and the collar 95 prevents movement of the ram assembly 90 in the proximal direction, as shown in FIGS. 4 and 5.
To create the hole 103 in the aortic wall 100 to perform anastomosis of the vein graft, the surgeon creates a small slit with a scalpel in the aortic wall 100 and introduces the punch head 31 of the device into the slit, or using the punch head 31 alone to penetrate the aortic wall 100 , advances the instrument housing 10 such that the punch head 31 is positioned within the interior of the aortic wall 100 , as shown in FIG. 2 . The surgeon next advances the cutting sleeve assembly 50 relative to the instrument housing 10 and the punch head assembly 30 , thereby causing a circular plug 104 to be removed from the aortic wall 100 because of the interaction between the annular cutting rim 55 and the punch disk 32 . The cutting sleeve assembly 50 is then locked in the advanced position, as shown in FIG. 3, by inserting locking pin 16 into the pin receiving aperture 58 of the tubular shaft 52 . By locking the cutting assembly 50 in the advanced positioned, the combination of the punch head disk 32 and the cutting sleeve 54 create a sealed chamber 56 , such that the aortic plug 104 is retained therein and not released into the blood stream. The surgeon then advances the instrument housing 10 distally, such that the dam assembly 70 is positioned interior to the aortic wall 100 , with the occluding body 92 of the deployment ram assembly 90 blocking hole 103 to prevent or significantly reduce blood loss there through. The deployment ram assembly 90 is then advanced relative to the dam assembly 70 and the cutting sleeve assembly 50 , and is locked in the advanced position by rotating locking collar 95 , as shown in FIGS. 4 and 5. This causes expansion of the elastic membrane 72 , the beveled head 91 of the occluding body 92 pressing radially outward against the rib members 73 . With the membrane 72 in the open, conical configuration, the instrument housing 10 is slightly withdrawn, such that the sealing rim 74 of the membrane 72 seats firmly against the interior side 101 of the aortic wall 100 . In this manner, blood within the aorta is prevented from passing through the hole 103 in the aortic wall 100 while the vein graft is being sutured in place. Because the axial length of the occluding body 92 is limited such that the proximal end of the occluding body 92 is positioned within the aorta at this time, such that an open area around the smaller diameter shaft 93 is presented, the surgeon has better access to the aortic wall 100 around hole 103 . The vein graft is loosely sutured in known manner with the device in place. Once the initial suturing is completed, the device is advanced slightly, the locking collar 95 is rotated to align the collar slot 96 with the ram guide slot 19 to allow movement of the handle 94 in the proximal direction and the deployment ram assembly 90 is retracted. With the occluding body 92 withdrawn, the elasticity of the membrane 72 causes it to resume its passive cylindrical shape (as in FIG. 3 ), its outer diameter being smaller than the outer diameter of the cutting sleeve 54 and occluding body 92 . In this passive configuration, the entire device is then removed from the hole 103 in the aortic wall 100 and between the sutures, with the surgeon quickly tightening the vein graft sutures to secure the vein against the aortic wall 100 .
It is contemplated that equivalents and substitutions to certain elements set forth above may be obvious to those skilled in the art, and the true scope and definition of the invention therefore is to be as set forth in the following claims.
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An anastomosis punch device, and method of using same, for creating a circular hole in the aortic wall, where the device also segregates the hole from the blood flow path such that no blood is lost through the hole during attachment of the vein graft. The invention is a hand-held punch having an elongated housing to be gripped by the surgeon, the housing retaining in a coaxially aligned manner a distally extended punch head, a cutting sleeve having a distal cutting rim which cuts a circular plug in cooperation with the punch head, an umbrella-like flexible dam formed of an elastic material and adjoined to the cutting sleeve in a manner which allows it to be deployed radially outward with the enlarged open rim facing the proximal direction, and a deployment ram movable axially relative to the dam to spread open the dam.
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This is a continuation of application Ser. No. 219,613 filed Dec. 24, 1980, now abandoned.
FIELD OF INVENTION
This invention relates to the manufacture of dry laid fibrous webs of high bulk whose end use is for towel, tissue, napkin, filter, and absorbent substrates and the like. Specifically, the invention relates to a method for increasing the bulk of said webs by proper control of the web fiber moisture content upstream of web consolidation.
BACKGROUND OF INVENTION
Air laid (or dry laid) webs are presently produced by dispensing dry loose fibers, generally less than 1/4 inch long, from one or more distributors onto a moving foraminous forming wire to obtain a loose web having little strength or integrity. To give some strength to the loose web, the web is then consolidated between two compaction rolls or belts. The strength thus imparted enables transfer of the web from the forming wire to a foraminous carrier wire, which carries the web through subsequent bonding and drying operations. After drying, the web is wound-up on a parent roll. One advantage of dry-laid technology over more conventional wet laid processing is the increase in the bulk of the product web, which decreases the amount of fiber required per unit volume while improving softness. Generally, then, it is desirable to increase bulk if other required properties can be at least retained. In some end use applications improved bulk and softness are more important parameters than other properties, which can be reduced appropriately. Bulk as used herein is defined as the four ply caliper of the product web by a standard caliper gauge such as the TMI micronmeter divided by its basis weight increased fourfold.
Loose fibers used in dry-laid processes are typically prepared by defiberizing pulp rolls, laps or bales in a hammermill or its equivalent, said fibers then being transported to the distributor pneumatically. During defiberizing, the fibers are dried unintentionally to a moisture content of less than 3% by weight, generally less than 2%. At this moisture level, the fibers transported to the distributor are subject to electrostatic charge forces which interfere with proper fiber transportation and web formation in that they clump together or adhere to machine surfaces, and are particularly dangerous because of the potential for explosion. To overcome this condition, existing practice is to enclose the forming section of the web manufacturing process within a room of regulated temperature and humidity. With the room temperature typically at 70° F. and at a relative humidity of about 70%, sufficient driving force exists for said fibers to absorb moisture from the humidified air. Through the length of the forming wire, and during the residence time of said fibers in the distributor and on the wire, usually between 4 and 15 seconds, the fibers will pick up 2 to 5% additional moisture before reaching the aforesaid consolidation rolls. Applicants have found that this increase in fiber moisture content deleteriously affects the bulk of the final web product. Applicants have found further that variations in bulk of the product web in the cross machine direction are attributable in part to the non-linearity of moisture content profiles transverse of the forming wire prior to consolidation.
SUMMARY OF INVENTION
It is an object of this invention to provide a method of increasing the bulk of product webs formed by dry laid technology.
A further object of this invention is to provide an automated method of increasing bulk of dry laid webs.
Another object of this invention is to provide a method for obtaining dry laid webs of uniform caliper in the cross machine direction.
A collateral object of this invention is to disclose a system to carry out the above stated methods.
These and other objects of the invention will be more clearly understood upon an inspection of the drawings, and upon a reading of the detailed description of the invention, a summary of which follows.
Applicants have found that there is a correlation between moisture content of a dry laid loose fibrous web before consolidation and the caliper of the finished product web. As moisture content of the web decreases, caliper, or, for the same basis weight product, bulk of the product web increases. However, this correlation does not apply to webs previously compacted. The invention then relates to a method of increasing bulk by partially drying the non-compacted web before consolidation preferably by means of a through air drier or a microwave drier which reduces moisture content of the web at this point in the process to less than 4% by weight. It has been found that the preferred drying temperature is about 180° to 260° F., while the air flow rate for commercial equipment would be between 200 and 400 fpm. at operating temperature and essentially atmospheric pressure.
This invention can be used to control the caliper of the product web by scanning the product web in the cross machine direction with a caliper measurement device, the output signals therefrom being transmitted to the drier to control a selected variable. In the preferred embodiment, the drier is comprised of a plurality of sections extending in the cross machine direction, each section receiving an output signal from the caliper sensor corresponding to the respective web section. In his way caliper in the cross machine direction can be controlled uniformly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram of a conventional dry laid web forming process.
FIG. 2 shows a pertinent portion of the process of FIG. 1 with the features of the present invention contained therein.
FIG. 3 is a graph illustrating the effect of drying upstream of the consolidation rolls on the bulk of a product web.
FIG. 4 is a schematic diagram of the control loop used in relation with the present invention.
DETAILED DESCRIPTION OF INVENTION
FIG. 1 shows the overall sequence of existing operations used in the production of fibrous webs by dry laid technology. Pulp rolls, laps or bales, here pulp roll 20, are fed into a defiberizer, here hammermill 22, and are comminuted to loose fibers 21 of generally less than 1/4 inch in length. The roll 20 typically has a moisture content of between about 5 to 12% by weight, depending upon the storage conditions. Mechanical energy from the hammermill 22 is dissipated in the form of heat, the temperature of the outlet fibers, which are transported pneumatically through transfer conduit 23 to one or mre distributors 24, being raised thereby to about between 130° and 200° F. At the conditions in the hammermill and the transfer conduit 23, the moisture content of the fibers is reduced to less than 3%, typically below 2%, by weight.
The loose fibers 21 from the distributors 24 are then dispensed onto an endless moving foraminous forming wire 25, a loose web 26 being formed thereby, said fibers being carried by a stream of ambient air drawn through the distributors 24 to a suction box 27 beneath said forming wire 25. Because little moisture is present, the individual fibers comprising the loose web 26 are not susceptible to inter-fiber hydrogen bonding as in the much older wet laid process. Hence, the loose web 26 does not have significant strength at this stage in the process. For this reason the loose web 26 is compacted between consolidation rolls 28, which impart to the web sufficient strength to effect a transfer from the forming wire 25 to a carrier wire 31.
The carrier wire 31 carries the compacted web 32 through the remaining bonding and drying operations. As mentioned above, dry laid webs are inherently incapable of hydrogen bonding, so that a binding agent material 36 is applied to the web 32 at bond station 33, the binding agent then being dried and cured in drier 34, here a through air drier of conventional design. The dried web 37 is then wound-up on a parent roll 35, completing the process steps for making dry laid webs as now represented by the prior art. Webs produced in this way are superior to wet laid webs in that the caliper of the product web is greater by about 40 to 120% and are perceptibly softer to the touch. For a given basis weight web, then, the bulk of the web is greater, bulk being defined as the 4 ply caliper in thousandths of inches as measured at a load of 26.6 gms./cm. 2 divided by basis weight increased fourfold in pounds per ream of 3,000 sq. ft. Conversely, the amount of fiber required to make a web of a given caliper is less as bulk increases. For this reason, it is highly desirable to obtain webs of greater caliper, provided, however, that other properties can be retained or maintained within commercially feasible limits. Furthermore, as bulk increases, greater softness is typically perceived.
In performing the above described process, certain other factors are also germaine to an understanding of the present invention. As mentioned above loose fibers 21, prior to their introduction into the distributor 24, have a moisture content of less than about 3%. To form a properly laid web, however, it is desirable that the moisture content of the fibers constituting web 26 just below the distributors 24 be greater than 3%, preferably greater than 4%, by weight, the additional moisture offsetting the undesirable electrostatic charges that arise with very dry fibers. To eliminate these charges, it is now a practice to enclose the forming section within a room, designated by numeral 29 in FIG. 1, the room air therein having a constant temperature and humidity environment. The temperature is generally between 65° and 85° F., while the relative humidity must be high enough to ensure that there exists a driving force for rapid moisture transfer to the fibers within distributors 24 and comprising the loose web 26 from the air drawn into the suction box 27. This transfer must take place essentially along the length of the forming wire 25, which may be fifty to two hundred feet long, and within the time the web remains on said wire 25. For a 100 foot forming wire, and with machine speeds of 400 to 1,500 fpm., the residence time is only 4 to 15 seconds, thereby necessitating a large driving force. Air relative humidity is generally maintained at about 70%, but may be set within a range of from about 50% to about 85% depending on such factors as loose fiber moisture content, forming wire speed, air velocity through the web, basis weight of the loose web 26, and fiber-moisture equilibrium properties. At the end of the wire 25, and before consolidation, the web 26 generally will have a moisture content of about 4 to 6% by weight.
Applicants have found that a reduction in the moisture content of the web 26 before consolidation in rolls 28 results in an increase of the caliper of the final product 35. FIG. 2 shows the pertinent portion of the apparatus of FIG. 1 together with the additional elements which are the subject of this invention. Like elements in FIGS. 1 and 2 have been similarly numbered. To effect a decrease in the moisture of the web 26 before consolidation, applicants have added a drier 51. The drier is preferably a through air drier or microwave drier. By this device, the web moisture content can be reduced from about 4 to 6% by weight to about 2 to 4% by weight, resulting in a bulk improvement of 10 to 15%.
Air to the drier 51, regulated by temperature and flow control means (not shown), is heated to between 150° to 350° F., preferably to between 180° and 260° F. At these conditions, the relative humidity of the air stream is very low, and a high driving force for drying is obtained. Hence, drier residence time of the web can be low, generally no more than 0.1 to 1 second. For a wire moving at 900 fpm, the length of the drier in the machine direction is only 1.5 to 15 feet, although the length is not critical. Air flow rates through the web can be regulated by the vacuum suction applied in the vacuum box 27, and should be consistent with the amount and rate of heat transferred to the web. Further, the air exhaust temperature should be compatible with the exhaust system design, particular with respect to explosion suppression equipment contained therein. Typically, the air flow in commercial installations would be about 200 to 400 fpm. at operating temperature and essentially atmospheric pressure.
FIG. 3 graphically illustrates the increase in bulk that is obtained with this invention. Bulk is plotted on the coordinate for unbonded webs, while drier temperature appears along the abscissa. It will be noted that the bulk increase is asymptotic at low air and at higher air inlet temperatures, with the greatest rate of change in bulk occurring in the preferred temperature range of 180° to 260° F. Bulk for unbonded webs, as opposed to bonded webs, was measured for convenience, the respective bulk measurements for each being linearly related.
As will be readily understood, the use of the drier to regulate bulk of final web products has significant application to the automatic control of product caliper. Caliper of the web 37 before the parent roll can be measured by an on-line unit 52 such as that marketed by Autech, Inc. under the trade name Dimension Gauge, Model 1000. This machine scans the moving web in the cross machine direction and electro-optically determines the web caliper. As indicated in the control logic diagram, FIG. 4, the output signal 62 transmitted from the caliper indicator 52 is compared with the set point reference signal 61, and in light of this comparison identified by box 62 in the logic diagram, adjusts the air flow damper or fuel flow control valve in accordance with box 64. Of course dual control by means of a split range control device can also be used. The change of the damper or valve position then adjusts the air flow or air temperature to the drier 51, respectively, as indicated in box 65. The caliper of the fibrous web 32 is thus modified, said modification ultimately appearing in the dried web 37. Of course, the increase in web caliper obtained downstream of the consolidation rolls 28 will not be equal to the increase at the parent roll inasmuch as further processing, e.g., bonding and drying, is required. However, the effect obtained at the consolidation rolls is retained in the parent roll, and increases the bulk of the final web product key about between 10 to 15%. Web moisture content before and after the drier 51 can also be measured, for example, by Quadra-Beam IR reflectance gauges manufactured by Moisture Systems Corporation, to provide additional useful information to the operator.
The above described method of caliper control may also be used to reduce variations in cross machine web caliper. In commercial units, the width of the web is about 10 to 30 feet. Neither uniform distribution of the fibers onto the wire, nor uniform humid air flow through the web to the suction box is always achieved satisfactorily. Maldistrbution occurs because of transverse pressure gradients within the suction box 27, which gradients cannot be adequately eliminated by baffle and damper means. Hence, the web 32 may have a non-uniform caliper profile in the cross machine direction because web sections proximate to the wire edge typically pick up greater moisture from the humid air in room 29 than the interior sections. These variations in caliper would then appear in web 37, the end product.
This problem can be alleviated to a considerable extent by providing multisectional driers 51 across the lateral web surface. Three sections are considered adequate, but more can be used if greater precision is desired. Output signals transmitted from the caliper monitor 52 and corresponding to the individual lateral sections of the web would thus regulate the temperature and/or air flow parameters for each of the drier 51 sections. That is, temperature and/or air flow parameters for each drier can be varied to achieve an essentially uniform web caliper in the cross-machine direction.
Predried, compacted, unbonded webs of the present invention were compared to conventional compacted, unbonded webs, and were found to have comparable tensile strengths despite the increase in caliper. Hence, webs 26 dried within device 51 can be transferred after consolidation in rolls 28 without difficulty. The method can also be used with either bronze or synthetic forming wires, the bulk increase being realized in each instance. Furthermore, the method does not contribute significantly to additional losses of fiber fines, and such fines which do accumulate can be blended with the defiberized loose fibers. No significant adverse effects were found on caliper, water holding capacity or tensile strength at fine addition rates of about 11% by weight of the total fibers.
The method described herein has other collateral advantages. Because the web 32 is more porous (greater bulk), the efficiency of the drier 34 is greater. Thus the drier 34 air temperature can be decreased, or less air supplied thereto. Hence, while the overall heat balance would show that more energy is necessary, this is not as great as would be expected. Secondly, binding agent can be expected to penetrate the more porous web of this invention more easily so that higher emulsion concentrations might be justified. This, too, could decrease the heat load on the drier 34.
EXAMPLE I
A series of six runs were made on a pilot paper making machine. Loose Ontario softwood pulp fibers were dispensed onto a bronze forming wire moving at 200 fpm. The forming room temperature was 85° F., and the relative humidity 55%. The first two runs did not use the drier 51 to remove moisture from the unbonded web, while runs 3 to 6 employed the drier at two different temperature levels. In runs 2, 4 and 4, 10.8% of the web consisted of recycled fines. In each run latex binding agent solids contributed to 17% of the basis weight of the finished web. Reel speed in each run was between 215 and 233 fpm. The results are summarized in Table I.
TABLE I__________________________________________________________________________ Caliper, 4-Ply Cured CD Drier Inlet Air Basis Weight (inches Water Holding Wet TensileRun Temperature (°F.) % Fines (lbs./rm.) × 10.sup.3) Bulk Capacity Ratio (gms./3")__________________________________________________________________________1 Not Used None 43.1 146 0.85 12.4 15912 Not Used 10.8 44.9 150.0 0.84 12.3 16053 240 None 39.6 169.3 1.07 16.6 13114 240 10.8 42.1 171.8 1.02 15.8 13345 200 None 39.6 160.7 1.01 15.5 N/A6 200 10.8 42.0 164.8 0.98 15.3 N/A__________________________________________________________________________
EXAMPLE II
A second series of five runs was conducted on a synthetic forming wire, No. 5,710, of polyester and obtained from the Appleton Wire Company. Air temperature in the forming room was 85° F. Relative humidity was 55%. Again, 12% latex solids were added to the unbonded web. The consolidation rolls were heated to about 195° F. in each case, and a pressure of 45 lbs. per linear inch applied to the web. In each run wire speed was about 230 fpm. Table II summarizes these runs.
TABLE II__________________________________________________________________________ Caliper, 4-Ply Cured CD Drier Inlet Air Basis Weight (inches Water Holding Wet TensileRun Temperature(°F.) % Fines (lbs./rm.) × 10.sup.3) Bulk Capacity Ratio (gms./3")__________________________________________________________________________1 Not Used None 41.5 161.4 0.97 14.7 13772 Not Used 10.8 42.9 165.2 0.96 14.6 12963 240 None 38.8 186.8 1.20 17.7 10264 240 10.8 43.2 192.5 1.11 18.4 10355 200 None 38.6 179.3 1.16 17.5 1127__________________________________________________________________________
The above description is intended to be exemplary of the invention only, the limits and constraints thereof being defined by the claims appearing below.
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A method of increasing the caliper and bulk of air laid dry fibrous webs, particularly such webs intended for use as napkin, tissue, and absorbent paper towel products by partially drying the loose formed fibrous webs to a degree of dryness of less than 4% prior to consolidation. In the preferred embodiment uniformity of the product web caliper in the machine direction is obtained by measuring the caliper downstream of the bond curing drier and before take-up on the parent roll, output signals therefrom being transmitted to the drier for adjustment of one or more of the drier parameters. Uniformity of caliper in the cross machine direction can be optimized by providing multisectional driers in the cross machine direction, a series of output signals from the caliper sensing means being transmitted to the respective drier sections for individual adjustment of the drier parameters.
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CROSS REFERENCES TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 09/546,465, filed Apr. 10, 2000 now U.S. Pat. No. 6,545,268.
FIELD OF INVENTION
This invention relates generally to mass spectrometry, in particular to a novel apparatus and method to prepare an ion pulse for ideal analysis in a time-of-flight mass spectrometer and in tandem mass spectrometers in which fragments are analyzed via time-of-flight mass spectrometry.
BACKGROUND OF THE INVENTION
Mass spectrometers are devices which vaporize and ionize a sample and then determine the mass to charge ratios of the collection of ions formed. One well known mass analyzer is the time-of-flight mass spectrometer (TOFMS), in which the mass to charge ratio of an ion is determined by the amount of time required for that ion to be transmitted, under the influence of pulsed electric fields, from the ion source to a detector. TOFMS has become widely accepted in the field of mass spectrometry, having the desirable attributes of high scan speed, high sensitivity, theoretically unlimited mass range, and, if an ion mirror is used, achievable resolutions of greater than 10,000. The spectral quality in TOFMS reflects the initial conditions of the ion beam prior to acceleration into a field free drift region. Specifically, any factor which results in ions of the same mass having different kinetic energies, and/or being accelerated from different points in space, will result in a degradation of spectral resolution, and thereby, a loss of mass accuracy. High mass accuracy is a desirable property in spectrometers used in the analysis of biomolecules, as it is one of the important factors in the unambiguous determination of peptide, and thereby protein, identity using database searching.
Two instrumental developments which minimize the effects of spatial and energy spreads on the final spectra are prevalent in the field. The first is the two-stage, or Wiley-McLaren, acceleration source, which provides first order space focusing, and the second is the ion mirror, or reflectron, which provides first order energy focusing. Additionally, the two widely adopted methods to produce gas phase biomolecular ions for mass spectrometric analysis, namely matrix assisted laser desorption ionization (MALDI) and electrospray ionization (ESI), have integrated certain instrumental attributes which have enhanced spectral resolution. The development of delayed extraction (DE) for MALDI-TOF as described in U.S. Pat. Nos. 5,625,184, 5,627,369 and 5,760,393 has made high resolution routine for MALDI based instruments. For ESI-TOFMS, high resolutions have been achieved by transmitting the ion beam through an RF only quadrupole and into the acceleration region of a TOFMS. The accelerating pulse is applied perpendicular to the direction of transmission. For both these methods, however, the resolution enhancement is not achieved without sacrificing another element of instrumental performance.
In DE-MALDI, a short delay is added between the ionization event, triggered by the laser, and the application of the accelerating pulse to the TOF source region. The fast (i.e., high-energy) ions will travel farther than the slow ions, in effect transforming the energy distribution upon ionization to a spatial distribution upon acceleration. A Wiley-McLaren source is used for space focusing. The delay time in DE-MALDI, however, can only optimize performance across a narrow range of mass to charge ratios, hence, resolution varies across the spectrum and calibration is non-linear. Additionally, the performance of the spectrometer is strongly coupled to the energy distribution from the ionization source. The highest mass resolution is achieved using so-called “threshold” conditions, i.e., operating the laser at the minimal fluence that yields observable ionization. If laser fluence is increased beyond this threshold value, ions are formed with a broader energy distribution, thereby degrading spectral quality.
It is known in the art that raising the laser fluence substantially above the threshold value increases the number of ions formed per laser pulse by orders of magnitude. As a consequence, in DE-MALDI the resultant direct coupling of the ionization source with the spectrometer is manifested in a tradeoff between resolution and sensitivity, that is one cannot simultaneously optimize conditions for ionization and mass analysis. An independent problem in MALDI based spectrometers is the observation, in some instances, of spectral features resultant from decay of ions during their flight time from the acceleration source region to the detector. Briefly, if ions created in the MALDI process are formed with excess internal energy, ions may dissociate prior to detection. The resulting fragments appear in the spectrum as unassignable chemical noise, “metastable” peaks, and/or increased background in the spectrum.
In a spectrometer equipped with an ESI source, a method termed orthogonal acceleration (oa) TOFMS is typically used. In oa-TOFMS, the ionization source may be separated from the acceleration region of the TOFMS by an RF-only quadrupole operating in the millitorr pressure regime. This quadrupole acts as a beam guide transmitting ions formed at atmosphere into the vacuum regions of the spectrometer. As described in U.S. Pat. No. 4,963,736, the passage of an ion beam through an RF-only quadrupole operated in the millitorr pressure regime leads to the “collisional cooling” of the beam. Through sequential collisions between the ion and the background gas, the internal energy of the ions is lowered to approach that of the background gas (i.e., the ion beam becomes thermalized). Similarly, the translational kinetic energy of the beam is lowered, restricting the motion of the ions to the low field region of the quadrupolar potential, resulting in a narrow beam of ions and more efficient transmission through restrictive ion optics. Lastly, reduction of the translational kinetic energy of ions coaxial to the beam, results in a denser beam with a smaller translational energy spread. As collisional cooling lowers the internal energy of the ions formed, harsh ionization conditions can be used without degrading spectral resolution and thus in an oa-TOFMS the ionization source becomes effectively decoupled from the spectrometer. The oa-TOFMS has been coupled to a MALDI ionization source, operated with a high repetition rate, high fluence Nd:YAG laser OPO 5000, as described by Anatoli Verentchikov et al. “Collisional Cooling and Ion Formation at Intermediate Gas Pressure”, Proc. 47 th ASMS Conference on Mass Spectrometry and Allied Topics, 1999, to create a quasi continuous beam which is pulsed into the TOFMS.
A key element of oa-TOFMS is that the beam enters the acceleration region of the TOFMS orthogonal to the direction the pulse is accelerated. (see U.S. Pat. No. 5,117,107 and Dodonov USSR Patent No. SU 168134A1 and published PCT application WO91/03071). Thus, the initial conditions of the accelerated TOF pulse are defined by the properties of collisional cooling in a quadrupolar potential, i.e., the ions have small spatial and energy distribution. One limitation in oa-TOFMS is that the duty cycle of the instrument, which is defined as the ratio of the time required to fill the acceleration region of the TOF spectrometer to the time for mass analysis, is typically a low 5-20%. A further disadvantage of oa-TOFMS is that the ions of the accelerated pulse maintain a small velocity component in the direction perpendicular to TOF acceleration. Therefore the ion pulse accelerated in the TOF has a natural “drift” angle which must be compensated for, either through the use of a large detector surface or an electrostatic steering deflector, a device which is known in the art to degrade resolution.
The problem of poor duty-cycle in oa-TOFMS has been addressed in a combination, or “hybrid” instrument in which the continuous ion beam is stored in a quadrupole ion trap and ejected as discrete pulses into the TOFMS by Mark Q. Qian et al. “Procedures for Tandem Mass Spectrometry on an Ion Trap/Reflection Time-of-Flight Mass Spectrometer”, Rapid Communications in Mass Spectrometry, 10, 1996. According to the authors, careful synchronization of the emptying of the trap and the TOF analysis can be used to achieve a near 100% instrumental duty cycle. With few exceptions, these systems use a commercial ion trap with a conventional geometry for both storage and creation of the TOFMS acceleration field electrodes. The use of the trap geometry for ion extraction is problematic, as the trap electrodes create a non-linear electric field, while optimal TOFMS operation, requires a linear electric field. Two references, U.S. Pat. No. 5,569,917 and published PCT Application WO 99/39368, discuss novel combinations of extraction voltages that can be used in conjunction with the conventional ion trap geometry to create and improve ion pulses for TOFMS. In each case, however, reference is made to using differential extraction voltages to compensate for higher order fields in the trap itself and neither reference demonstrates the resolution of either oa-TOFMS or DE-TOFMS systems. Existing work on MALDI-trap TOFMS, as described by Peter Kofel et al. “Matrix Assisted Laser Desorption/Ionization Using a New Tandem Quadrupole Ion Storage Trap, Time-of-Flight Mass Spectrometer”, Rapid Communications in Mass Spectrometry, 19, 1996, has demonstrated that as the electric field in the center of the quadrupolar potential is substantially linear, ions are sufficiently collisionally cooled.
The issue of a poor extraction field in ion trap TOFMS systems has been addressed by the use of a segmented ring ion trap (see, for example, Qinchung Ji et al. “A Segmented Ring, Cylindrical Ion Trap Source for Time-of-Flight Mass Spectrometry”, Journal of the American Society of Mass Spectrometry, 7, 1996) the purpose of which was to couple an electron impact source to a TOFMS with a 100% duty cycle. In this instrument the “trap” was created by four simple ring electrodes, operated such that an oscillating field which is substantially quadrupolar was created. Ions are trapped in the field formed by the rings for a set period of time. At the end of the trapping period, the RF potential is rapidly switched off and a unidirectional, linear field in the (former) trapping volume is actualized by applying DC pulses to the rings, the magnitudes of which are proportional to the distance from that electrode to the source plate. Resolution attained on this TOFMS, however, was not optimal. Although an ideal extraction field was claimed to be formed, the position and energy of the ions at the time the field was applied was found to be strongly dependent on the phase of the quadrupolar potential at the instant the RF power supply was switched off. Ions that are moving in the direction opposite to that of the TOFMS accelerating field required a “turn around” time during extraction and this additional time degraded the spectral resolution. Also, the phase dependent spread in kinetic energies resulted in the necessity to use a reflectron that was specially designed to accommodate ions with a large velocity spread.
The performance of existing hybrid ion trap-TOFMS instruments has been substantially limited by the following factors:
Initial trapping of the ion beam is inefficient due to the necessity to overcome the barrier created by the rapidly oscillating quadrupolar potential. A significant portion of ions formed will be lost in the injection process unless the ions are formed within the trapping volume.
When a continuous ion beam is used, only those ions that have, through collisions with the background gas, lost sufficient translational kinetic energy to be confined in the quadrupolar potential will have stable trajectories in the ion trap. Consequently trapping efficiency is low.
The conventional electrode geometry of the three-dimensional ion trap has a relatively low space charge capacity. If, for example, more than 1000 ions are confined in 1 mm 3 , energy gained from inter-ion repulsion will result in the ions having a translational kinetic energy, which is greater than thermal energy, thereby lowering TOF resolution. For typical trap operating conditions of 1 millitorr of helium, fall collisional cooling requires approximately 30 ms. Thus, to maintain ions at thermal energies, total throughput of the system must be below 3×10 4 ions per second, a value which is not adequate for most applications.
In order for ions to be stored effectively, typically 1 millitorr of helium is present in the trap. However, since the same volume is used for storage and acceleration, during acceleration ions may undergo numerous collisions which alters the ideal trajectories in the TOF analyzer. Additionally, in the three-dimensional ion trap, the combination of poor confinement of the ion beam and the non-linear acceleration field result in a wide ion cloud to extract; therefore, to enhance sensitivity a large extraction aperture is used between the trap and TOFMS. This raises the pressure in the flight tube and thereby increases both the number of collisions which transpire and the load on the vacuum pumps in the flight tube.
Another broad application of mass spectrometry is tandem mass spectrometry, denoted MS/MS. An MS/MS instrument provides the capability to isolate an ion based on its mass to charge ratio, fragment the selected ion, and mass analyze the fragments. Spectra from MS/MS instruments are used to provide information on the structure and bond strength of the precursor ions (sometimes called parent ions). Additionally, through reducing the amount of chemical noise, MS/MS machines actually improve the spectral signal to noise ratio and hence the detection limit of the precursor ions.
The ability of TOFMS to provide parallel analysis of all mass components is used in multiple tandem instruments, classified as hybrid TOFMS. The most common of these hybrid instruments combines quadrupole and TOF technology, often referred to as QqTOFMS. An example of a QqTOFMS has been described by Howard R. Morris et al. “High Sensitivity Collisionally-activated Time-of-Flight Mass Spectrometer”, Rapid Communications in Mass Spectrometry, 10, 1996. This instrument is constructed from two tandem quadrupoles and an orthogonally situated TOFMS. The first quadrupole, a mass filter, is used for precursor ion selection; fragmentation is precipitated via sequential low energy collisions with an inert gas in an RF-only quadrupole operating in the millitorr regime. The resultant fragment ions are analyzed by an oa-TOFMS. Increasing precursor selection resolution in the mass filter results in decreasing sensitivity, thus achievement of unit resolution is only possible with significant ion losses. Consequently, resolution is compromised in most analytical applications, and the above discussed problems of the second oa-TOFMS, namely poor duty cycle and a drift velocity orthogonal to the TOF axis, also affect performance.
The ion trap TOFMS, can also be operated as a hybrid tandem TOF instrument. In MS/MS mode, during storage precursor ions are isolated and fragmented in a quadrupole ion trap and the contents are analyzed by TOFMS. As the processes of ion isolation and fragmentation are based upon the principles of resonant excitation, the ion traps in such instruments must provide well defined, and near ideal, quadrupolar electric fields. Thus the conventional three-dimensional ion trap electrode geometry operated with a background pressure of 1 millitorr helium is required. The disadvantages of this configuration for TOF analysis were discussed above.
In another hybrid TOF instrument used for MS/MS analysis, the three-dimensional ion trap is replaced with a linear, or two-dimensional, ion trap, (orthogonal to the direction of TOF acceleration) as detailed in published PCT Applications WO 99/30350 and WO 98/06481 and demonstrated by J. M. Campbell et al., as reported in “A New Linear Ion Trap Time-of-Flight System with Tandem Mass Spectrometry Capabilities”, Rapid Communications in Mass Spectrometry, 12, 1998. In the linear ion trap, ions are confined by a quadrupolar potential in two dimensions and by electrostatic potentials in the third dimension. Thus electrostatic, rather than oscillating quadrupolar, potentials control the flow of ions into and out of the trap and the processes of injection and extraction are both simpler to implement and more efficient than in the three dimensional ion trap. Additionally, the linear ion trap provides a larger trapping volume and thus an enhanced ion storage capacity over the three-dimensional trap. In the above PCT applications, ions were injected into the TOF through coupling lenses. In U.S. Pat. No. 5,763,878, the concept of extracting ions from the linear ion trap through a gap in the rod structure is described, and reference is made to the advantage such a concept would provide for TOF analysis in an oa-TOFMS system. However, the instrument described in this patent suffers from a slow cycle of ion selection and fragmentation in the first MS stage as well as the problems discussed above for all oa-TOFMS.
Another method of TOF based MS/MS analysis uses TOF mass analyzers for both precursor ion selection and fragment ion analysis. U.S. Pat. No. 5,206,508 discusses a TOF/TOF system without a mechanism for precursor ion isolation. A second patent, U.S. Pat. No. 5,202,563, discloses a TOF/TOF system with two reflecting-type mass analyzers coupled via a fragmentation chamber. Lastly, co-pending U.S. patent application Ser. No. 09/233,703, commonly assigned as with the present application, describes a TOF/TOF system and includes a detailed description of a timed ion selector (TIS) used to attain high resolution ion selection with a TOF based system. An instrument based on this patent has been used to record fragment spectra on a wide selection of ions, including biomolecules. This TOF/TOF system has been named a double DE system. Ions are formed in a region with a DE-MALDI source, the precursor ions are selected by the timed ion selector and transmitted to the collision cell. The resultant collection of precursor and fragment ions is transmitted into a second TOF acceleration region. At the time that the ions of interest are near the center of the second source, a high voltage pulse is applied, and the ions are accelerated toward the detector. Varying the time of application of the second acceleration pulse creates the second nominal DE system, through which the resolution of the fragment ion spectra can be optimized.
Various effects limit attainable performance of TOF/TOF instruments (mass accuracy and resolution). Analogous to DE-MALDI, the energies and positions of fragment ions entering the second source are dependent on mass to charge ratios. As the velocities of ions entering the second acceleration region of a TOF/TOF spectrometer are orders of magnitude greater than those extracted from a matrix in a standard DE source, limitations known in the art for DE-MALDI (e.g., non-linear calibration) are magnified in the TOF/TOF instrument. Consequently, uniform-focusing conditions cannot be attained across the entire mass range, limiting high resolution (and mass accuracy) to a narrow window of fragment ion masses. In addition, optimization of the resolution in the second MS is strongly dependent on conditions in the first MS, which complicates tuning of the instrument. Furthermore, ions which gain internal energy through collisions, but for which the kinetics of dissociation are such that fragments form during transmission in the field free region of the second TOF, appear as metastable ions in the spectrum, resulting in chemical noise and unassignable spectral features.
In spite of the numerous efforts in the past as reflected by the development of various instruments outlined above, there still is not an apparatus and method that simultaneously addresses all of the ideal requirements of TOF and tandem TOF analyses. For example, the need still exists for an MS instrument wherein final spectral quality is decoupled from the mechanism of ionization, such that conditions that provide maximum instrumental sensitivity (e.g., high laser fluence) can be used without sacrificing spectral quality. Furthermore, if harsh ionization conditions are used, a technique for “cooling” ions that are typically formed with sufficient internal energy to fragment, may be needed within the ion source, such that the spectral degrading effects of metastable fragmentation are suppressed. Ideally, resolution and accuracy should be uniform across the mass range and mass calibration should be linear. Lastly, a 100% duty cycle should be achieved with both pulsed and continuous ionization sources. In addition to the aforementioned desired features, MS/MS analysis using tandem TOF instruments ideally should possess the ability to decouple operation of both the first TOF and second TOF MS stages.
SUMMARY OF THE INVENTION
The present inventors have realized that the combined use of dynamic trapping and collisional cooling in a segmented ion trap operating at appropriate gas pressure provides a simple and effective method to prepare an ideal pulse for TOF analysis. In doing so, this invention addresses issues such as instability of ions, poor initial conditions, dependence on laser energy and/or ion losses at the time of ion pulse formation, which heretofore have been a significant limitation of TOFMS. Additionally, the invention addresses problems with respect to the issues of injection into and extraction from an ion storage volume to a time-of-flight mass analyzer. The present invention exhibits a high degree of flexibility and can be implemented in numerous existing TOF systems with MALDI and ESI ion sources, and can be used to substantially improve existing TOF/TOF systems. The invention is also adaptable to various hybrid systems with TOF as a final mass analyzer.
In a preferred embodiment, the invention includes a pulsed ion source (MALDI source or ESI source with a storing and pulsing multipole ion guide), a segmented ion trap filled with gas at about millitorr pressure, and a TOF analyzer. Ions from the source are injected into and dynamically trapped in the ion trap, collisionally confined to the center of the trap and subsequently extracted as a pulse into the TOF analyzer.
Briefly, one preferred embodiment of the invention, as implemented in a single stage TOFMS, operates as follows:
(1) Stable ions are formed using a known ionization mechanism, such as MALDI, ESI, thermospray, ICP, FAB, APCI, etc. sources, that are either pulsed or continuous in nature.
(2) The ions are pulse injected into a segmented ring trap. If MALDI is used, the ionization source could be located external to the trap in a region operated at a higher pressure than the trap. If ESI is used, the ions can be stored in an external ion guide, and pulsed into the segmented ring ion trap.
(3) The ions are trapped via dynamic trapping. The ions are initially confined in the segmented ring trap by rapidly switching on or ramping up a high voltage RF power supply. The applied RF potential creates a quadrupolar field confining the ions in two or three dimensions. In the instance of two-dimensional quadrupolar trapping, the ions are confined in the third dimension through electrostatic potentials.
(4) The ions are velocity damped via collisions with a neutral gas. The subsequent lowering of the ion translational energy will confine ions to the low field (i.e., center) region of the quadrupolar potential.
(5) The ions are pulse extracted from the segmented ring trap and into a TOFMS. This process is accomplished by rapidly switching off the RF potential, and rapidly (e.g., within ˜100 ns) applying an extraction potential to the ring electrodes of the trap. The extraction potential is linear and unidirectional, applying to each ring a pulse, the magnitude of which is proportional to the distance from that ring to the first ring electrode.
(6) A pulsed, high voltage, acceleration stage is adjacent to the trapping electrodes, and is differentially evacuated to operate at a pressure intermediate from that of the trap and the TOF flight tube.
(7) The extracted ions are analyzed via the TOFMS. To attain optimal resolution the TOF analyzer is equipped with an ion mirror.
One of the key elements of the invention is a use of a segmented ion trap. Unlike conventional ion traps with hyperbolic-shaped electrodes, a segmented ion trap utilizes multiple planar electrodes. When appropriate RF potentials are applied to these planar electrodes, an approximate quadrupolar field is generated resulting in confinement of ions. During ion extraction, the RF field is turned off and a unidirectional, linear field is achieved through application of suitable DC potentials to the planar electrodes. The invention utilizes two types of segmented trap: a three-dimensional trap, formed by ring electrodes and a two-dimensional trap, also termed ‘linear segmented trap’, formed by parallel flat plates. Both types of segmented trap are applicable for all the examples discussed below, and the specific type used is selected based on technical conveniences.
The segmented ion trap is used for trapping, storing, cooling and pulsed ejection, but not employed for isolation, excitation, and/or mass analysis. Consequently, there is no need to establish and maintain well defined ion trajectories in the quadrupolar field in the trap. The parameters of the system embodied by the invention can thus be optimized for pulse preparation for TOFMS. In doing so, various aspects of the invention provide numerous advantages and overcome the following problems of the known trap-TOF systems:
Inefficient collisional trapping of a continuous ion beam is replaced by a dynamic trapping of a pulsed ion beam.
Stabilization of ions can be improved when desired by lowering internal energy in gas collisions in the ion source. Gas collisions also lower kinetic energy of ions and thus improve efficiency of dynamic trapping in the segmented trap.
Confinement of ions in the trap can be improved by the use of a smaller size trap and the selection of a stronger RF field at a higher frequency, which allows a broad mass range of ions to be stable in RF field. The optimization becomes possible since the trap is used exclusively for storage and there are no requirements to select and control RF frequencies to maintain precise ion trajectories as imposed by resonant excitation techniques.
For certain applications, the space charge limitation can be reduced by the use of a two dimensional trap, low mass cut off in the trap, and a higher repetition rate of pulsed extraction.
The gas load on the TOF system can be reduced by using pulsed gas introduction into the trap or into the ion source and by the introduction of an additional differentially pumped acceleration stage.
The quality of TOF spectra (resolution and mass accuracy) can be improved by the better confinement of the ion beam, the absence of beam defocusing in a uniform accelerating field, and a low probability of gas collisions during acceleration and within a TOF flight tube.
One preferred embodiment provides a system with collisional stabilization of MALDI generated ions at an intermediate gas pressure with a subsequent pulsed injection into the next differentially pumped stage where ions are dynamically trapped in a segmented trap, wherein the ions are stabilized, confined, and pulse ejected into the TOF. In one particular implementation, the trap is a two dimensional segmented trap and pumping of the analyzer is improved by an additional pumping stage between the trap and the TOF. Both axial and orthogonal coupling geometries with the TOFMS are viable options for this embodiment. Collisional cooling in the source (i.e., prior to the confinement and acceleration region) allows the use of a high repetition and/or high energy laser to enhance sensitivity of analysis. Analyzer performance is decoupled from source conditions, resulting in improved, uniform resolution and a linear calibration.
In one embodiment of the invention, the gas is introduced into the source region via a pulsed valve to reduce gas load on vacuum pumps and to provide a lower gas pressure for ion ejection. In another embodiment of the invention, the gas is similarly introduced into the trap via a pulsed valve and ions are formed in the same differentially pumped stage. In yet another embodiment of the invention, an infrared laser is used to produce initially stable ions and gas pressure is reduced to the minimum sufficient for ions confinement. It is known in the art that use of an infrared laser with MALDI results in the formation of an excessive number of weak complexes with the matrix. Broadband excitation in, or heating of, the trap could be used to break these complexes and provide cleaner peaks of molecular ions.
In another preferred embodiment, the trap/TOF pulse preparation stage is coupled to an ESI source with a modulating multipole ion guide. The trap in this embodiment is a linear two-dimensional segmented trap to allow a wide range of masses to be trapped, thereby substantially increasing the space charge capacity of the trap. The trap is connected to the TOF analyzer via an intermediate, differentially pumped stage. The ion beam is fully utilized, providing a 100% duty cycle. The drift component of ion velocity is essentially eliminated and ions are injected into the TOF parallel to the axis.
The invention further encompasses the use of dynamically trapped, collisionally cooled ion preparation as part of a tandem TOF system. The precursor ions are injected into a trap with the energy desired for collisional dissociation. In one embodiment, the injected pulsed beam is dynamically trapped, undergoes fragmentation in earlier collisions and the resulting collection of fragment and precursor ions are collisionally cooled in the trap. Thus, the event which promotes the increase in internal energy necessary for fragmentation (e.g., collisions with a surface or a background gas), the trapping electrodes, and the background neutral gas are in a common volume, and activation and dissociation occur simultaneous with trapping. In another embodiment of the invention, the precursor ions are activated (i.e., their internal kinetic energy is increased) by surface induced dissociation (SID). The fragment ions formed in the SID process sequentially bounce off the surface, are dynamically trapped by the RF field and then are slowly damped in gas collisions. In both aforementioned embodiments, the use of dynamic trapping to efficiently capture the ion pulse allows the gas pressure in the trapping volume, and thus the mass analyzer, to be reduced. Consequently there will be fewer scattering collisions during both ejection into, and flight through, the mass analyzer, thereby allowing higher resolution to be achieved.
The invention provides a significant improvement of beam characteristics in front of the second TOFMS, since kinetic energy is damped in gas collisions and ions are confined to the center of the trap. As a result, the resolution is improved, linear calibration is achieved, and operation of the analyzer is decoupled from the ionization source.
Briefly, a preferred embodiment of the system for tandem TOF instruments operates as follows:
(1) A pulsed ion beam is formed from a MALDI or ESI source.
(2) A precursor ion is selected. In this embodiment the method of selection is a linear TOF equipped with a timed ion selector. In order to increase resolution of selection, a reflecting system can be employed.
(3) The ions are decelerated to the desired injection energy. In this manner, there is control of the energy available for the activation event, trapping is ensured, and ions of different mass but identical velocity to the precursor are filtered prior to entering the fragmentor volume.
(4) The precursor ions are pulse injected into a fragmentor. The fragmentor could contain a surface for SID (such as a gold surface with a monolayer of an organic known to promote efficient conversion of translational kinetic energy to internal energy) and/or a relative high pressure (1×10 −2 to 1×10 −4 torr) neutral gas for CID. In either instance some fraction of the ion population rapidly (e.g., in 1 μs to 1 ms) dissociates into fragment ions.
(5) The collection of activated precursor and fragment ions in the fragmentor is dynamically trapped and collisionally cooled for a fixed time frame as described above with respect to the TOF-only method. For tandem mass spectrometry applications, the trapping time is varied considering both the needs for collisional cooling and precursor dissociation kinetics.
(6) The contents of the fragmentor are extracted into the second TOFMS for fragment analysis using a uniform pulsed electric field.
(7) The fragments are mass analyzed by the second TOFMS as described above.
In one preferred embodiment, a folded geometry is employed, and the same mass analyzer is used for both MS 1 and MS 2 . The beam is formed in a pulsed source and is passed through the orifice of an annular detector. The beam is reflected in an electrostatic mirror at a small angle to the TOF axis. Precursor ions are selected with high resolution in a timed ion selector and enter the collisonal cell, equipped with a segmented ion trap. Fragments are trapped, cooled, and ejected into the same TOF analyzer but in the reverse direction. After being reflected in the mirror the ions hit the detector. This embodiment of the invention provides an inexpensive and compact solution for TOF-TOF instruments.
The invention summarized above addresses the limitations in TOF analysis as previously described. In particular, confining the ions in a collisional environment between the source and the pulsing necessary for TOF analysis provides a period of relaxation such that excess internal energy may dissipate prior to analysis. This will “cool” the internal temperature of the ions, lowering the rate of thermal decomposition, and thereby minimizing metastable fragmentation and the spectral noise associated with it. The combined use of a quadrupolar field, with collisional cooling, will result in the spatial localization of the low energy ions in the center of the electrode structure, thereby creating perfect initial conditions for extraction into the TOF analyzer. In addition, confining the ions to the center of the field will minimize the spatial spread of the extracted ions, largely eliminating the correlation between mass resolution and phase at the time of extraction. The segmented ring geometry provides an electrode geometry that can be used to create both a quadrupolar and an accelerating field. Additionally there should not be ion losses in the extraction phase. The present invention is presented as a general apparatus and method for preparing an ideal pulse for TOF analysis, and is easily adaptable to existing configurations of instruments.
BRIEF DESCRIPTIONS OF THE DRAWINGS
This invention is pointed out with particularity in the appended claims. The above and further advantages of this invention may be better understood by referring to the following description taking in conjunction with the accompanying drawings, in which:
FIG. 1A is a block diagram of one embodiment of the invention for use in TOFMS.
FIG. 1B is a block diagram of another embodiment of the invention for use in TOF-TOF MS.
FIG. 2A is a schematic of one embodiment of the invention for use in MALDI-TOFMS.
FIG. 2B is a schematic and accompanying three dimensional view of a segmented ring trap used in the embodiment of FIG. 2 A.
FIG. 3A is a timing diagram of the operation of the trap used in the embodiment of FIG. 2 A.
FIG. 3B is a graphical representation of the voltages present during ion trapping and ion ejection from a segmented trap for the embodiment shown in the FIG. 3 A.
FIG. 4A is a schematic of an embodiment of the invention for use in ESI-TOFMS.
FIG. 4B is a schematic of a two-dimensional segmented ring ion trap used in the embodiment of FIG. 4 A.
FIG. 5A is a block diagram of one embodiment of the invention used in TOF-TOF instrument systems.
FIG. 5B is a schematic of the fragmentor used in the embodiment of FIG. 5A where the left panel is used for collision induced dissociation (CID) and where the right panel is used for surface induced dissociation (SID).
FIG. 6A is a schematic of one embodiment with folded TOF-TOF geometry and with a SID/CID fragmentor.
FIG. 6B is a schematic of the SID/CID fragmentor of the TOF-TOF of the embodiment of FIG. 6 A.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1A, in brief overview, a time-of-flight mass spectrometer 11 in accordance with the present invention includes a pulsed ion generator 12 , a beam preparation unit 13 , which includes a segmented ion trap 14 , and a TOFMS 16 , which includes a differentially pumped acceleration region 15 . In operation, a pulse of stable ions is formed in the pulsed ion generator, then injected into the trap, dynamically trapped and collisionally cooled in the segmented ion trap at a sub-millitorr gas pressure. After a sufficient time frame for the trapped ion cloud to adopt the characteristics of an ideal pulse for TOF analysis, the ions are accelerated out of the trap and into the TOFMS for analysis.
Referring to FIG. 1B, in brief overview, the present invention further encompasses a tandem time-of-flight mass spectrometer 21 , including a pulsed ion generator 22 , a first TOF MS 23 with a timed ion selector 24 , a fragmentor 25 , containing a segmented trap 26 , and a second TOFMS 27 . In operation, ions are formed in the pulsed ion generator and accelerated into the first TOFMS towards the timed ion selector. Selected ions traveling with a uniform velocity (roughly corresponding to a few keV energy) are decelerated at the entrance into the trap, such that ions of a single mass to charge ratio enter the fragmentor, while metastable fragments (having lower energy) are deflected/defocused. Mass-selected ions enter the trap at a desired energy (e.g., ˜50 eV for 1 kDa precursor ion) and may either be subjected to collision induced dissociation (CID) or surface induced dissociation (SID). The resulting fragments and remaining precursor ions are trapped in the volume of the segmented trap. After trapping for an adequate time frame such that both an adequate number of fragments are created and fragment ions are collisonally confined to the axis of the trap (i.e., a suitable pulse for TOF analysis is formed), the collection of remaining precursor and fragment ions are accelerated into the second TOFMS.
Both the single and tandem TOFMS embodiments briefly described above employ the same principle of ion pulse preparation prior to TOF analysis, namely the dynamic trapping of the ion beam in the segmented trap followed by collisional cooling, preferably at low pressure, and pulsed ion ejection out of the segmented ion trap.
In more detail, and referring to FIG. 2, one preferred embodiment is shown for the application of the invention to a MALDI TOFMS 31 system. The pulsed ionization source 32 contains a laser 33 , a sample plate 34 , and a pulsed gas inlet system 35 . The ionization source is located a short distance (typically 1 to 3 mm) away from the first electrode plate 36 A of the segmented ring ion trap 36 . The trap is connected to a set of RF and pulsed power supplies 37 . The trap is in communication with the TOF 39 via an electrostatic acceleration stage 38 . All stages are differentially evacuated by a set of vacuum pumps 40 .
FIG. 2B presents a schematic and three dimensional view of the segmented trap. In order to achieve optimum ion injection, confinement, and extraction, the trap 36 in this embodiment is formed by four electrically isolated rings 36 A to 36 D. Details on the operation of the trap as well as timing and voltages on each component are shown in FIGS. 3 A and 3 B. By altering the voltages applied to the rings, these electrodes can be used to create the electric fields required for both ion confinement and unidirectional extraction. For ion trapping, the rings form a three-dimensional quadrupolar field, similar to that of the three-dimensional segmented trap described in the above mentioned Ji et al. publication. The first 36 A and last 36 D of the four rings are grounded and middle two electrodes 36 B and 36 C are connected to an RF power supply. An important aspect of the invention is that at the ejection step the potentials applied to the electrodes rapidly (e.g., about 100 ns) switch from a configuration which confines the ions to a unidirectional, linear acceleration field (FIG. 3 B). The magnitude of the extracting pulses applied to the rings are proportional to their distance from the first end cap ( 36 D).
In operation, and referring to FIGS. 2A, 2 B, 3 A and 3 B, the pulsed laser fluence (energy per unit area) is adjusted so that the laser pulse produces a burst of ions. Ions are ejected from the sample plate with initial velocities of 300 to 700 m/s, depending upon the matrix used. Using a pulsed gas inlet, the ion source 32 is synchronously filled with gas to a pressure of ˜1 torr. The internal energy of the ions is rapidly cooled in gas collisions in the source. Ions are rapidly (˜1 to 10 μs) transferred into the trap by weak electric fields and by diffusive flow between the source (<10 millitorr) and the trap (˜0.1 millitorr). As ions approach the center of the trap, the RF voltage is turned on (or ramped up) and subsequently ions are dynamically trapped. Ions gradually (typically in ˜10 ms) lose their kinetic energy in collisions with the background gas and thus move to the center of the trap, creating a “cold” and well-confined ion pulse tailored for subsequent TOF analysis. At the time the pulse is ready for extraction, the gas is evacuated by a turbo pump to a pressure below 0.3 millitorr thus scattering collisions during acceleration are avoided. The RF voltage is rapidly switched off and electric pulses are applied to the trap electrodes such that a uniform unidirectional electrostatic field is created for injecting ions into the TOF mass spectrometer.
The invention provides for the parallel optimization of multiple parameters which are key to final spectral quality, which include the following:
Collisional cooling in the ion source;
Optimal geometry of trap electrodes;
Simultaneous dynamic trapping of a broad mass range;
Selection of optimal parameters of the applied potential for beam confinement;
Consideration of the degradation of TOF resolution by space charge in the trap;
Cooling and pulsing rate in the trap;
Gas load on pumping system and scattering collisions in the trap and in the TOF;
Limited mass range of the trap-TOF MS.
One important aspect for certain applications of the invention is stabilization of ions in the ion source and prior to injection into the segmented trap. Ions generated in a MALDI process have a relatively large internal energy, which can lead to metastable dissociation, usually observed in TOFMS on a 10 to 100 μs time scale. In one embodiment of the present invention, collisions between ions and neutral gas introduced into the ion source at 1 torr pressure lead to rapid (˜1 μs) dissipation of internal energy, thereby stabilizing the ions and minimizing metastable fragmentation. Alternatively, instead of supplying a gas, stable ions can be formed with the use of an infrared laser. In this case, the ion source can operate at ˜1 millitorr, i.e., the same pressure as the ion trap.
The configuration shown in FIG. 2A permits a very high laser irradiance, which is known in the art to increase the number of ions produced by orders of magnitude. Therefore, a high repetition rate, high-energy laser, for example, an Nd-YAG laser at 355 nm wavelength, is preferred. Several kHz repetition rate of the Nd-YAG laser improves speed and sensitivity of analysis compared to commercial MALDI instruments equipped with a low repetition rate N 2 laser and typically operating at repetition rate below 20 Hz. Collisional cooling in the source and the confinement in the trap provide a complete decoupling between ion production and TOF analysis. Therefore, strong variations in the ion source do not affect TOF performance and the mild ionization properties of the method. Such variations may include non-conductive substrates, rough crystals, volatile matrices, outgasing gels, or tissues.
The injection into the trap should be rapid, soft and 100% efficient. Ions are transmitted from the ionization source 32 with a low kinetic energy, regulated by the energy offset between the sample plate 34 and the trap 36 . Ion neutral collisions during this process should be of sufficiently low energy to avoid ion dissociation, thus, for typical operating conditions the injection energy must be substantially lower than 50 eV/kDa. Complete ion sampling into the trap is ensured by a relatively large solid angle in the sampling aperture (1 mm diameter at ˜1 to 3 mm distance), by a transmitting electric field, and by diffusive flow into the lower pressure trapping region.
For dynamic trapping it is important to maintain all mass components in the trap at similar velocities. The MALDI process itself is known in the art to eject ions of all masses at the same velocity (300 to 700 m/s, depending on matrix properties). The gas pressure introduced in the MALDI ionization regions would similarly transmit all ions at approximately the same velocity (300 to 500 m/s). The mass dependent drift velocity in an electric field should not strongly exceed gas velocity. This requirement is consistent with the soft injection process. At a plate potential of ˜10V and for gas pressure of 1 torr (mobility, K, is ˜0.1 m 2 /Vs), the average drift velocity (ν=kU/L) will also remain substantially below 300 m/s and thus all mass components will be injected into the trap nearly simultaneously. The RF voltage is turned on or ramped up once the ions reach the vicinity of the center of the trap. The resulting quadrupolar field will create the trapping potential for retaining ions in the trap.
An important aspect of the present invention is that the trap parameters are chosen such that the collisionally cooled, trapped ion cloud is ideally designed for TOFMS analysis. As is known in the art, the resolution in TOFMS spectra is degraded by a spread in the spatial and the velocity distribution of the ions at the time of acceleration. Therefore, the invention allows the properties of ions in quadrupolar potentials to be used to maximize attainable resolution by confining the ion cloud tightly.
In the case of an RF only trap the motions of ions in quadrupolar fields are well known and described by the Mathieu equation. The stability of the harmonic trajectory of the ion in the quadrupolar field depends on Mathieu parameter, q u, defined as
q=− 8 zV rf /mΩ 2 u 0 2
where V rf is the 0 to peak amplitude of an RF power supply with an angular frequency, Ω, applied to the geometry with the field radius (in the coordinate u) of u 0, m and z are the mass and charge of ions. In the commonly used first stability region of the Mathieu equation, ions with q<0.908 have stable trajectories in the trap, i.e., ions with mass above the low mass cut off are confined in the trap. The q parameter also defines the position and energy of the ion in the trapping volume. For q<0.4, the motion of an ion can be approximated as a particle in harmonic potentials having the “pseudopotential” or “dynamic” well depth D as a function of distance to center r:
D ( r )= qV rf ( u/u 0 ) 2 /(8) 1/2
Typically, commercial ion traps have u 0 larger than 1 cm and radio frequency below 1 Mhz. In order to simultaneously trap ions with mass to charge ratios varying from 500 to 4000 (i.e., the typical requirement for peptide mass mapping applications) the preferred trap parameters are: u 0 =5 mm, V rf =5 kV and Ω=2π×3 MHz. These parameters differ from those of the conventional ion trap in order to provide a steeper trapping potential and thus tighter confinement of the ion cloud. Additionally, after collisional cooling is completed (typically after 10 ms trapping at a pressure of 0.1 millitorr), the energy distribution (at all depth of potentials) is close to thermal, and thus, at room temperature, the energy spread is ˜0.03 eV, which corresponds to a velocity spread of 50 m/s for ions of mass 1 kDa. The spatial distribution in the segmented ion trap (i.e., the width of the ion cloud) is determined by the balance of thermal energy and the depth of RF potential. For ions with a Mathieu parameter q=0.1 (heaviest component in this example of m/z=4000), RF amplitude zero to peak of 5 kV, and field radius of the trap of 3 mm, the spatial spread is below 2*u˜0.05 mm. The product of spatial and velocity spreads in such a trap is lower than the best characteristics in DE MALDI, namely ˜300 m/s velocity spread and 0.02 mm of non-correlated spatial spread (see Peter Juhasz et al. Journal of the American Society of Mass Spectrometry, 8, 1997). Hence the resolution of segmented trap-TOFMS should be comparable to, or better than, the resolution obtained in DE MALDI for the optimized mass range at or near threshold laser energy. The overall performance of the trap-TOFMS for this embodiment, however, is improved over that of DE-MALDI, as the trapped ions do not have a net component of velocity and, thus, resolution could be optimized for the entire mass range and mass calibration becomes a simple square root relation between mass and flight time.
The tight confinement of the beam may be altered by the space charge of the ion cloud. The potential created by space charge, Φ, is approximated by Φ=Ne/4πε 0 r where N is the number of trapped ions, e is the charge of electron, r is the radius of the ion cloud, and ε 0 is the vacuum permeation constant. The inventors believe that the failure to maintain the three dimensional ion trap population at levels sufficiently low to minimize energy gain from space charge is one issue which has led to existing trap-TOFMS configurations to exhibit worse resolution than is predicted by theory. Therefore, trap capacity for illustrative purposes of the teachings of the present invention is calculated by equating the force of inter-ion repulsion with the thermal energy of the gas in the trap. The potential of the ion cloud with radius of r=0.05 mm will remain below thermal energy (0.026 eV) if the number of ions N in the trapping volume is below 10,000. The space charge is strongly reduced by choosing the parameters of the applied potential such that the low-mass cut-off is near m/z=500, which eliminates the matrix ions which carry most of the charge in MALDI. Considering that the trap holds analyte ions from a single laser shot, one can realize that the capacity of the trap is compatible with the yield of ion production in conventional DE MALDI. In DE MALDI the dynamic range of the mircochannel plate (MCP) detector for single laser shot is ˜10,000 ions (10 6 channels with ˜100 channels killed per ion in the second MCP plate). This is also confirmed by the typical settings for a transient recorder operated in counting mode, as an eight-bit transient recorder saturates when ion signal exceeds ˜100 ions per isotope. Space charge effects become more pronounced if the laser is operated at higher energy as an increased ion count can also be achieved by operating the laser at a higher repetition rate. Techniques for dealing with such space charge effects will be further discussed subsequently in conjunction with the cooling rate and ion flux throughput.
An important result derived from the use of the invention is the achievement of a 100% duty cycle. The necessity to provide for an adequate time frame for collisional cooling is a constraint to take into account in determining the maximum possible repetition rate at which the instrument can be operated. In one commercially viable example, the pressure in the trap is varied from ˜3 millitorr at the time of initiation of the gas valve pulse in the trap to ˜0.1 millitorr at the time of ion extraction from the trap. For an ion with a mass of 1000 Da and a cross section of σ=10 −18 m 2 , and a collision gas of nitrogen (m=28 Da) at 3 millitorr (gas density is n=10 20 m −3 and thermal velocity ν˜300 m/s), collisional cooling to thermal temperatures requires ˜1 ms (T˜M/mnσV), and thus the corresponding maximum instrumental repetition rate is ˜1000 Hz. Other factors to consider in determining the optimum repetition rate are the speed of gas evacuation out of the trap and the duration of gas valve pulse.
A further source of spectral degradation in TOF spectra known in the art is collisions between the ion and latent gas particles in the acceleration stage and in the TOFMS itself. These are minimized in accordance with one embodiment of the invention through the use of lower pressure in the trap at the ejection stage. The pressure reduction is achieved with the use of multiple stages of differential pumping, pulsed gas introduction, and small apertures. Specifically, as detailed in FIG. 3A, the end caps of the segmented ion trap serve as differential pumping apertures between the source, trap, and acceleration regions. The conductance through the ˜1 mm diameter aperture is in the order of 0.1 L/s (10 L/s through 1 cm 2 ). In the MALDI source region, nitrogen is pulsed added to a pressure of 1 torr for the purpose of rapid stabilization of ions. Pulsed gas valves with 250 μs open time are available commercially from Parker Hannifin Corporation (Cleveland, Ohio). During application of the pulse the gas pressure in the trap would be defined by the pumping speed from the trap. The pumping speed is limited by conductance of a 1 cm diameter cell to a ˜30 L/s vacuum pump, giving a 3 millitorr pressure pulse in the trap. After the pulsed gas introduction, the pressure drops as a ratio of the delay time and the duration of the pulsed valve opening. The desired pressure in the trap is 0.1 torr, corresponding to a mean free path of λ˜1/nσ˜30 cm and thus the probability of scattering collisions in 5 mm trap is only 1.5%. The desired 0.1 millitorr pressure is achieved after 10 ms delay and thus the repetition rate of ejection in this example is limited to 100 Hz.
The pumping requirements downstream of the trap are less challenging. Since in the example above the ion cloud is confined to 0.1 mm and a uniform field is used for ion extraction, an aperture diameter of 1 mm is adequate for complete ion transmission. This corresponds to a gas flow of 0.1 L/s from the trap with a maximum peak pressure of ˜3 millitorr and a minimum pressure of 0.1 millitorr. A single turbo pump with a moderate pumping speed of 250 L/s will maintain an acceptable pressure below 10 −6 torr in the flight tube. By introducing an additional stage of differential pumping, for example, surrounding the DC acceleration stage, the gas pressure in the TOF analyzer could be maintained below 1×10 −7 torr, which is absolutely safe for TOFMS operation. If this second stage of differential pumping is added, the size of the exit aperture can be increased further, thereby ensuring a 100% ion extraction.
Earlier the space charge capacity for a typical three dimensional trap was estimated as 10,000 ions per cycle and it was found that a 100 Hz repetition rate can be achieved. These values define the throughput of the system which is equal to 1E+6 ions per second, which exceeds signals currently obtainable in DE MALDI.
The range of mass to charge ratios that can be simultaneously confined in the segmented ion trap is determined by the depth of the dynamic well. For the operating parameter discussed above, i.e., u 0 ˜5 mm, Ω=3×2π MHz and V rf =5000 V, the Mathieu parameter of 100 kDa protein is q˜0.002 and the depth of dynamic well, D, is 3 eV. Thus the maximum translational kinetic energy the ion can have and simultaneously be trapped is 3 eV, which corresponds to a translational velocity (again for the 100 kDa protein) of approximately 75 m/s. Such a velocity is prohibitively low for an ion formed by MALDI. To increase the dynamic well depth in order to trap higher mass MALDI ions, the frequency of the RF drive can be reduced, which will raise the q values across the mass range. Consequently, the upper and lower mass limits of the trap will be raised. For instance, if the frequency is lowered to 500 kHz, the 100 kDa ion will experience a well depth of 100 eV, and the lower mass cut off of the trap will be 20 kDa. A further consideration for high mass proteins with large collision cross sections is the occurrence of scattering collisions during the acceleration process. To minimize such collisions the gas pressure would have to be reduced by a factor of 100, which can be simply achieved by low frequency, pulsed introduction of the collision gas.
While the above description details one preferred embodiment for application to a pulsed ionization source, in this instance MALDI, the invention can be equally applied to continuous ionization sources, such as ESI. A preferred embodiment of the invention in application to continuous ionization sources is shown in FIG. 4 A. The TOF analyzer for a continuous ion source 41 includes a pulsed ion source 42 , a segmented linear trap 45 and orthogonally oriented TOF analyzer 49 with differentially pumped DC acceleration stage 49 A. The pulsed ion source 42 is formed by a continuous ion source 43 and a multipole ion guide 44 with a modulating cap 44 A. The linear trap 45 contains three sets of segmented traps 46 , 47 and 48 and electrostatic end cap electrode 48 A. The segmented linear ion trap helps minimize duty cycle losses typical in oa-TOFMS. In this embodiment of the invention, the multipole ion guide 44 behaves as a linear ion trap as described in the J. M. Campbell et al. reference cited above. In particular, the multipole ion guide can be used, with methods well known in the art, to store ions, to selectively eject ions of a specific mass to charge ratio or range of mass to charge ratios, and to fragment ions of a selected mass to charge ratio. Transmission of the stored ions from the multipole ion guide to the linear ion trap 45 of the TOFMS 47 is modulated by the potential applied to electrostatic cap 44 A such that duty cycle loses are minimized.
The details of the segmented ion trap of the TOFMS and the applied voltages for each mode of operation of the trap are shown in FIG. 4 B. In the segmented linear ion trap, a two dimensional quadrupolar potential, well known in the art from mass filters and RF-only beam guides, is applied in cross beam direction, and electrostatic potentials confine the beam coaxial to the multipole. The trap itself 45 is formed by three segments 46 , 47 and 48 , each segment having six parallel plates (labeled A to F). The top (A) and bottom (F) plates are analogous to one pole pair in the mass filter. The four additional plates (B to E), in sets of two opposite each other, are analogous to the second mass filter pole pair. Although for the purpose of this embodiment of invention each plate is electrically isolated, when trapping is invoked opposite poles (B,C and D,E) have the same RF voltage applied, while adjacent poles have potentials which are of the same amplitude and frequency, but which are 180° out of phase. For this embodiment, the effective field radius of the trap is ˜5 mm, and the length is 25 mm.
The trap 45 is formed from three segments and two end cap electrodes. The distribution of the electrostatic potential is shown in FIG. 4 B. The electrostatic potential of the middle trap segment 47 is lower than those of both the first 46 and the third 48 trap segments, such that ions are confined in the middle segment 47 . The potential offset of the middle trap segment 47 is also lower than that of the multipole ion guide 44 in order to promote the injection of ions into the segmented trap. Two electrostatic caps 44 A and 48 A assist trapping. The potential of the exit cap 48 A is constant and held high to prevent ions from escaping. During ion injection, the potential of the entrance cap 44 A is lowered for a short period of time (e.g., ˜10 to 100 us). After the desired number of ions is injected, the potential of electrostatic cap 44 A is raised again. Ions are dynamically trapped and oscillate within the linear trap. The RF potential is connected to the segmented linear trap for both ion injection and trapping. The kinetic energy of ions (in all coordinates) decreases via gas collisions with increased time of confinement in the multipole, and, eventually, ions precipitate near the axis of the middle trap segment 47 . Dynamic trapping allows reduced gas pressure to be applied in the segmented linear ion trap, minimizing collisions during the extraction step. The parameters of the confined beam were estimated above. The combination of a ˜50 m/s velocity spread and 0.05 mm radius of the pulse is an improvement over the comparable parameters in conventional oa-TOF, typically ˜20 m/s velocity spread and 0.5 mm spatial spread.
After the collisional cooling step the ions are extracted from the linear trap through the narrow slit 47 , covered with mesh, in the top electrode 45 . For this extraction step, the RF is rapidly turned off and accelerating pulses are applied to the trapping electrodes such that a linear, unidirectional extraction field is created. This can simply be done by maintaining the top electrode at ground and applying a high voltage extraction pulse to the other electrodes, the magnitudes of which are proportional to the distance between the particular pulsed electrode and the top trap plate. The pulse of ejected ions is transferred to a differentially pumped acceleration region with a constant electric field and then transmitted into the TOF flight tube, which is equipped with a single stage ion mirror.
One major advantage of using the segmented trap-TOF combination in this embodiment is the ability to fully utilize the beam from the continuous ionization source, provided the throughput of the system is sufficient to handle this ion flow. The amount of time required for collisional cooling depends on the pressure in the trap region and is usually selected to maximize the repetition rate, without creating too high a gas load in the TOF system. At a pressure of 0.3 millitorr, cooling with a heavy gas occurs at ˜10 ms, thus a repetition rate of 100 Hz is feasible. Another advantage of using the two dimensional trap structure of this embodiment is that the space charge capacity of the segmented linear trap is ˜30 fold higher than that of the three-dimensional trap and thus approximately 3×10 5 ions could be contained in the trap without any significant effect on the energy distribution of ions. An ion flow of 3×10 7 ions/sec is approaching the maximum current achievable in an ESI system. In an attempt to increase ion flow to the maximum currently reported values of 3×10 8 ions/sec (50 pA) as specified in the API 3000 MS System (PE Biosystems, Foster City, Calif.), the pressure could be increased to ˜1 millitorr and the trap may be elongated. If the higher pressure were used, it would be particularly advantageous to use either pulsed gas introduction, or an additional stage of differential pumping. If the conducting slit were a 1 by 25 mm rectangle, the gas flow through the slit would be ˜3 L/s. Two stages of differential pumping, each pumped with a speed of 300 L/s, would result in a sufficiently low analyzer pressure of ˜10 −7 torr (i.e., 100 fold pressure reduction per stage that is equal to the ratio of pumping speed to the gas flow). While this high ion flow would result in the use of high speed, large memory data acquisition systems, it is possible to reduce the frequency of pulses to 100 Hz (from 10 kHz which is typical in oa-TOF). This will similarly decrease the load on averaging memory, hence a larger number of bits could be used in a transient recorder.
Another advantage of this invention over existing systems is that collisional cooling removes drift velocity i.e., the velocity component in the direction orthogonal to TOF acceleration. Consequently, there is only a minimal natural drift angle, and thus it is unnecessary to adapt the instrument for any post acceleration deflection of the beam, or a larger detector surface. As a result, a higher resolution can be attained with fewer steering elements and with a smaller detector surface.
The embodiment of the invention discussed above and shown in FIG. 4A could be easily applied to existing oa-TOFMS systems, such as the Qq-TOFMS or the LIT/TOFMS, where ions are fragmented prior to orthogonal acceleration. Similarly, the segmented ion trap could serve as the final trap in a multistage linear ion trap.
Another embodiment of the invention is concerned with the application of the principles of ion pulse preparation as applied to a tandem mass spectrometer, which in the preferred embodiment is constructed from two TOF based mass analyzers. The schematic diagram of this embodiment is shown on FIG. 5 A. The tandem TOF mass spectrometer 51 includes a pulsed ion generator 52 , a first TOF analyzer 53 for selection of primary ions by a timed ion selector 53 A, a fragmentor 54 and a second TOF 59 for mass analysis of fragment ions. The pulsed ion generator comprises a pulsed ion source (such as MALDI) or a continuous ionization source (such as ESI) with orthogonal injection into the source region of a first TOFMS 53 or by injection using the storing ion trap as previously described. The fragmentor 54 includes a deceleration lens stack 55 , a segmented trap with the gas inlet system 57 , an acceleration stage 58 and a differential pumping system 57 with two stages 55 and 58 . The geometry of the fragmentor used in this embodiment is shown in FIG. 5B, which depicts two techniques wherein low energy fragmentation is induced by collisions between the ion and a neutral gas (left panel) or a surface (right panel).
In operation, a pulse of ions is produced by the ion generator 52 and injected into the first (linear) TOF 53 (TOF1). Velocity based separation of the precursor ion is achieved using the timed ion selector 53 A situated at the focal plane of TOF1 53 . The timed ion selector can be of various types well known in the art such as a single pulsed gate (e.g., a Bradbury Nielsen gate) or a single deflection gate. Selected ions are decelerated in the lens stack 55 , such that low energy metastable ions can be filtered out before entering the fragmentor. Additionally the decelerating lens stack can be used to adjust the collision energy. Mass selected ions enter the three-dimensional segmented ring trap 56 of the fragmentor 54 as a well focused pulse (in space, a <1 mm spread and in time, a <100 ns spread). In the case of CID fragmentation (FIG. 5B left panel) ions are dynamically trapped when they reach the center of the trap by turning on or ramping up the RF potential. Dynamically trapped ions continue oscillating within the trap at the same kinetic energy. The trap is filled with gas at ˜0.1 millitorr pressure via a gas inlet system. Although a fixed gas pressure can be used, in this embodiment, the gas is introduced via a pulsed valve and gas pulses are synchronized with ion production in the source. Trapped ions collide with the background gas and have a single collision per several passes. Excited ions slowly dissociate within the trap and lose kinetic energy in gas collisions. In ˜10 ms ions lose sufficient kinetic energy to be effectively confined in the center of the trap. After completing the cooling step, the product ions are extracted as pulses into the second TOF (TOF2) for mass analysis. In the case of surface induced dissociation SID (FIG. 5B right panel), ions are directed onto a back wall of the trap, collide with the surface and bounce off with ˜1 eV kinetic energy. Fragments and internally excited precursor ions are trapped dynamically with subsequent cooling and extraction into TOF2. In either case, ion confinement is achieved using the three-dimensional segmented ring ion trap shown and described with respect to the embodiment of FIG. 3 B. The implementation of dynamic trapping with collisional cooling as a method of pulse preparation, is analogous in operation to the previously described trap in MALDI-TOF applications. The improvements to the spectrum are as discussed above. The estimated velocity and spatial spreads of 50 m/s and 0.05 mm respectively are substantial improvements over comparable parameters in existing tandem TOF instruments, namely 1000 m/s and ˜1 mm.
In most existing TOF-CID-TOF instruments, ions are transmitted with high kinetic energy through the collision cell with a relatively small loss of energy and a finite probability of single collision with gas. The internal energy available in such a configuration is a small fraction of the kinetic energy of injected ions. In this embodiment, the kinetic energy is fully absorbed in multiple collisions and thus low kinetic energy (˜50 eV/1 kDa) is used at injection.
In TOF-TOF instruments such as that described in U.S. patent application Ser. No. 09/233,703, the translational kinetic energy is in the kilovolt regime and thus the kinetics of dissociation are expected to be rapid. However, those rapid channels mostly produce multiple stage fragmentation and small fragments carry limited structural information. The larger mass, structurally informative fragments are typically created in the 10 to 100 μs time scale. In current TOF-TOF and SID-TOF instruments such fragments are observed in TOF 2 as metastable peaks. Whether or not the fragments are detectable is in part related to the kinetics of dissociation. In the present invention, the time available for fragmentation increases, hence the fragmentation efficiency in the trap increases and metastable fragmentation in TOF 2 would become negligible. For example, at a storage time in the trap T TRAP =10 ms and a flight time in TOF 2 T TOF =0.1 ms, the in flight fragments can not exceed T TOF /T TRAP , which is 1%.
The issue of trapping in the quadrupolar field yields special consideration in the tandem embodiment of the invention. Dynamic trapping of ions requires that the translational kinetic energy of the ions in the direction of acceleration is lower than the depth of the trapping well in that coordinate. Additionally, for tandem mass spectrometry it is necessary to trap a broader mass range of fragment ions. Ideally, the mass range of the trap should extend from 100 Da to 2000 Da, such that both low mass immonium fragment ions and the precursor ions can be simultaneously trapped. The stability criterion that q<0.908, required for all of these conditions to be met, dictates that the RF drive must be operated with higher amplitude and angular frequency than conventional ion trap technology. For example, a peptide ion with a mass of 2 kDa and 150 eV of translational kinetic energy could be trapped with an applied RF potential having a zero to peak amplitude of 5 kV. The mass range could be further increased by introducing a segmented linear ion trap aligned along the beam with a ˜100 millitorr pressure. The fragments would be thermalized in a single pass through such a cell. The resultant fragments could be pulse injected into the subsequent trap for ion beam preparation, followed by TOF analysis as shown on FIG. 2A or an ortho-TOF as shown on FIG. 4 A.
Another embodiment of the tandem TOF instrument makes use of SID rather than CID for precursor ion activation. For details of this embodiment of the invention, reference is made to FIG. 6 A. The methods of ion formation and precursor ion selection are as shown in FIG. 5 A. For SID, ions are substantially decelerated as they enter the fragmentor and are electrostatically focused (at an angle) onto an inert surface such as gold, covered with a monolayer of an organic substance such as ethanioate. Such a surface is known in the art to promote SID by reducing ion losses and emission of secondary ions of the surface material and by enhancing the conversion of translational kinetic energy to internal ion energy. The efficiency of this conversion is known in the art to be 10-40%, depending on the nature of the surface, the ion, and the impact energy. Ions that impinge on the surface with energy of 50 to 100 eV will gain ˜10 to 40 eV internal energy and 0.2 to 1.0 eV kinetic energy. One advantage of SID is that the increase in internal energy is substantially lower than the activation energy required in CID, leading to greater control over the accessible fragmentation channels in MS/MS. Furthermore, the SID scheme provides an efficient method of absorbing the primary kinetic energy of ions and simplifies trapping of secondary ions, usually emitted with ˜1 eV (or less) energy.
The embodiment of the instrument utilizing the SID technique, shown in FIG. 5B, operates as follows. The precursor ions are admitted into the cell and strike the specially coated probe in the back wall of the fragmentor. The surface collision event is well defined in time as ions are time focused and time selected in TOF1. At gas pressures below 1 millitorr the effect of gas collisions in the cell is negligible and primary energy deposition is defined by the SID process. The excited precursor ions (with a minor degree of fragmentation) are repelled from the probe by a low potential (typically a few volts) and travel within the trap for 3 to 10 μs. After ˜1 μs delay after the collision, the RF amplitude is ramped up to trap fragment ions. Ions are stored for sufficient time (˜10 ms at 0.3 millitorr) to undergo slow fragmentation and to be collisionally confined.
Referring to FIG. 6A, a further embodiment of the invention is a TOF/TOF instrument using SID or low energy CID in the fragmentor. This instrument, termed the folded geometry TOF/TOF, has the same geometry as the single MALDI instrument shown in FIG. 3 A. However, in the folded geometry configuration the same TOF mass analyzer volume is used for both stages of tandem MS analysis.
In operation, ions are extracted from the source 62 , which may be either a MALDI source or a continuous ionization source with orthogonal injection, through an annulus 63 A in a microchannel plate 63 situated after the acceleration region 64 . From the acceleration region ions are injected into a reflecting TOF 65 at a small angle to the axis. After separation in time in the TOF, ions are selected by a timed ion selector 66 , pass through a decelerating lens 67 , and enter the fragmentor 68 . The SID fragmentor in this embodiment is the same as described and shown in the FIG. 6B embodiment. It includes the electrode configuration as described for the three-dimensional segmented ions trap, enclosed within a housing with a single differential pumping aperture to the TOFMS 65 . At the back wall of the fragmentor, a probe 69 with small metal surface coated with a monolayer of a surface known in the art to promote SID activation. Pressure in the fragmentor is maintained at 0.1 to 1.0 millitorr, through the addition of a pulsed neutral gas. The pulse is triggered prior to ion pulse injection. As there is only one aperture in the fragmentor, the load on the pumping system is reduced relative to the embodiment shown in FIG. 6 A. The activated ions are directed to the center of the fragmentor and the RF is rapidly turned on such that the precursor is confined in a collisional environment for 1 to 10 ms. Through collisional cooling these ions are stabilized and confined to the low field region near the center of the quadrupole trap. After complete cooling of the pulse (1 to 100 μs) the precursor and fragments are ejected out of the trap by applying a high voltage pulse of opposite polarity on the trap electrodes. The pulse is axially injected into the same reflecting TOF in the reverse direction of its transmission. Ions are directed onto the detector surface 63 in front of the acceleration region 64 .
The folded geometry configuration is also readily applicable to tandem mass spectrometry with collisionally induced dissociation (CID). In this case ions are dynamically trapped in the fragmentor 68 before they reach the SID probe. In dynamically trapped ions, kinetic energy is slowly converted to internal energy through gas collisions and experience decomposition with subsequent cooling and pulsed ejection into the TOF.
The publications referred to herein are hereby incorporated by reference to the extent that each is relied upon for the understanding of the various described embodiments of the invention.
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The use of a segmented-ion trap with collisional damping is disclosed to improve performance (resolution and mass accuracy of single stage and tandem time-of-flight mass spectrometers. In the case of single stage spectrometers ions are directly injected from a pulsed ion source into the trap supplied with RF field and filled with gas at millitorr pressure. Subsequently, the ions are dynamically trapped by an RF-field, cooled in gas collisions and ejected out of the trap by a homogeneous electric field into a time-of-flight mass spectrometer. In the case of tandem mass spectrometric analysis the pulsed ion beam is injected into a time-of-flight analyzer to select ions-of-interest prior to injection into the trap at medium energy to achieve fragmentation in the trap.
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BACKGROUND OF THE INVENTION
The invention relates to a deflection control device having a stationary supporting member comprising a series of hydrostatic supporting elements, and in the supporting member there are provided ducts for supplying or discharging pressure fluid for the supporting elements, two ducts being separated from one another by a partition wall.
A deflection control roll of this kind is known from U.S. Pat. No. 3,802,044, issued Apr. 9, 1974 FIG. 8. In that known roll, bores are provided in the supporting member which are associated with the individual hydrostatic supporting elements and through which the pressure fluid is supplied to the supporting elements. In that case, portions of the supporting member form the partition walls, through which the ducts associated with the individual supporting elements are separated from one another.
It has been proposed in U.S. patent application Ser. No. 738.561 filed Nov. 3, 1976 now U.S. Pat. No. 4,047,273, issued Sept. 13, 1977 to form the ducts for supplying the pressure fluid for the supporting elements by coaxial tubes which are situated in a bore of the supporting member and comprise at their ends in each case a partition wall, which separates two adjacent ducts from one another and abuts in a sealing-tight manner on the wall of the bore.
In the case of the aforesaid constructional arrangements, when the supply to the supporting elements in the series is to be variable from one supporting element to another, it is necessary to provide a separate duct for the pressure fluid in the supporting member for each supporting element, and a suitably comprehensive control device is required for controlling the pressure fluid in the ducts.
SUMMARY OF THE INVENTION
The invention has as its object to provide a deflection control device with which pressure fluid supply can be varied from supporting element to supporting element in a simpler manner and in such a way as to take up relatively little space in the supporting member.
In a deflection control device of the type initially described, this object is achieved according to the present invention in that the position of the partition wall along the series of supporting elements is variable.
Advantageously the position of the partition wall is variable by displacement of the partition wall along the series of supporting elements.
Advantageously the partition wall can be secured on an insert element introduced into the supporting member, and the position of the partition wall can be varied by intechanging the insert element for another insert element with a different position of partition wall.
It is also advantageous if the partition wall is arranged on an insert element introduced into the supporting member, and can be displaced after the insert element is removed.
BRIEF DESCRIPTION OF THE DRAWING
Constructional examples of the subject of the present invention are shown in a simplified manner in the drawings, by means of which the invention will be explained in detail. In these drawings
FIG. 1 shows a vertical axial section through a deflection control roll,
FIG. 2 shows a section taken on the line II--II of FIG. 1,
FIG. 3 shows a vertical axial section through a further constructional form,
FIG. 4 shows a vertical axial section through another constructional form,
FIG. 5 shows a section taken on the line V--V of FIG. 4,
FIG. 6 shows a vertical axial section through a further constructional form,
FIG. 7 shows a section taken on the line VII--VII of FIG. 6,
FIG. 8 shows a section corresponding to FIG. 7 through a further constructional form,
FIG. 9 shows a vertical axial section through a further constructional form,
FIG. 10 shows a section taken on the line X--X of FIG. 9,
FIG. 11 shows a section corresponding to FIG. 10 through a further constructional form,
FIG. 12 shows a vertical axial section through another constructional form,
FIG. 13 shows a section taken on the line XIII--XIII of FIG. 12,
FIG. 14 shows a section taken on the line XIV--XIV of FIG. 12 and
FIGS. 15 and 16 show vertical axial sections through two further constructional examples.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the constructional example of a deflection control device shown in FIGS. 1 and 2, that is to say a deflection control roll, a shell 1 is adapted to be supported by a series of supporting elements 2 which are arranged in a supporting member 3. Situated in the supporting member 3 is a bore 4 with a partition wall 5 wich divides the bore into a duct 6 1 and a duct 6 01 .
The position of the partition wall 5 can be varied along the series of supporting elements 2. For this purpose the partition wall 5 can be displaced along the series of supporting elements 2.
The displacement of the partition wall 5 is effected by means of a rod, that is to say by means of a screwthreaded spindle 7, which is mounted axially in a cover 8 of the supporting member 3, and engages in a screwthreaded bore of the partition wall 5. The screwthreaded spindle 7 can be rotated from the outside by means of a square head 9.
As FIG. 2 shows, there is also provided adjacent the screwthreaded spindle 7 a second screwthreaded spindle 7' which has a screwthread of the same pitch but in the opposite direction of rotation. Each of the screwthreaded spindles 7 and 7' carries an equally large gear wheel 10 and 10' respectively, these gear wheels being in engagement with one another. The arrangement avoids rotation of the partition wall 5 when the screwthreaded spindle 7 rotates. But the partition wall 5 could also be prevented from rotation in some other way, for example by providing a longitudinal wedge in the bore 4 or by replacing the screwthreaded spindle 7' by a cylindrical rod secured in the cover 8.
The duct 6 1 is connected by means of a pressure conduit 11 to a source of pressure medium not shown here. The duct 6 01 on the other hand, is connected to an outlet which is not specifically designated in the drawings. By displacement of the partition wall 5 the working width of the deflection control roll can be modified. Thus the supporting elements 2 situated at the left side of the partition wall 5 in FIG. 1 are subjected to pressure and the supporting elements 2 situated at the right side of the partition wall 5 are relieved of pressure. By displacement of partition wall 5 the boundary between the supporting elements which are under pressure and the supporting elements which are relieved of pressure can be displaced from supporting element to supporting element. Although only a single supply duct and a single discharge duct is necessary for the pressure medium of the supporting elements, the working width of the deflection control roll can be varied in small steps over the entire width of the roll.
In the constructional example shown in FIG. 3, four partition walls 5 1 to 5 4 are provided which engage with a common screwthreaded spindle 7. The partition wall 5 1 and 5 2 bound a duct 6 1 for pressure fluid. The partition walls 5 2 and 5 3 define a duct 6 2 for pressure fluid. The partition walls 5 3 and 5 4 define a duct 6 3 for pressure fluid. At the right-hand side of the partition wall 5 4 in the drawings there is situated a discharge duct 6 01 , and at the left side of the partition wall 5 1 there is situated a discharge duct 6 02 .
The screwthreaded spindle 7 in FIG. 3 comprises four successive different kinds of screwthreaded sections. The screwthread section belonging to partition wall 5 1 is provided with a right hand thread and has a large pitch. The screwthread section associated with the partition wall 5 2 has a right hand thread and has a relatively small pitch. The screwthread section associated with partition wall 5 3 is given a left hand thread and has the same relatively small pitch. The screwthread section associated with the partition wall 5 4 is given a left hand thread and has the large pitch. If the screwthreaded spindle 7 is rotated in one direction, the partition walls 5 1 and 5 4 approach one another to a relatively considerable extent, whereas the partition walls 5 2 and 5 3 approach to a relatively small extent.
In this way the working width of the roll which is determined by the spacing of the partition walls 5 1 and 5 4 can be modified in small steps, that is to say from supporting element to supporting element. The ratio of the three pressure zones which correspond to the ducts 6 1 , 6 2 and 6 3 , can be left unaltered.
In the constructional example shown in FIG. 4 the partition walls 5 1 to 5 4 are arranged on an insert element 12 introduced into the supporting member 3. To displace the partition walls 5 1 to 5 4 the insert element 12 is taken out of the supporting member 3 and the partition walls 5 1 to 5 4 are displaced into the desired position and fixed on the insert element 12 by means of an adjusting screw not shown here. The ducts for supplying or discharging the pressure fluid extend through the displaceable partition walls. The ducts are each formed by a flexible tube 13 1 , 13 2 , 13 3 , 13 4 .
As FIG. 5 shows more particularly, the flexible tubes 13 1 , 13 2 , 13 3 , and 13 4 extend through the partition wall 5 1 , and the flexible tube 13 1 opens into the space between the two partition walls 5 1 and 5 2 . The partition wall 5 2 has the flexible tubes 13 2 , 13 3 and 13 4 extending through it, the flexible tube 13 2 opening into the space between the partition wall 5 2 and the partition wall 5 3 . Correspondingly the flexible tubes 13 3 and 13 4 extend through the partition wall 5 3 and the flexible tube 13 4 extends through the partition wall 5 4 .
If when the partition walls are displaced they are additionally rotated, the flexible tubes may become wound helically on the insert element 12, so that the flexible tubes may stick fast in the partition walls and in the cover 8 of the supporting member 3.
In the constructional example according to FIG. 6 and FIG. 7 an insert element 12 is introduced into the supporting member 3. On this element there are secured partition walls 5 1 to 5 3 which can be displaced after the insert element is taken out. The insert element 12 comprises four bores 14 1 , 14 2 , 14 3 and 14 4 which extend over its entire length. These bores 14 1 to 14 4 are connected with the ducts 6 1 , 6 2 , 6 3 , 6 4 defined by the cover 8 and the partition walls 5 1 , 5 2 , 5 3 . Since the bores 14 1 to 14 4 extend over the entire width of the roll, bores corresponding to the connecting bores 15 1 to 15 4 can be arranged at each part of the width of the roll. Connecting bores which are no longer required after asjustment of the partition wall 5 1 to 5 3 can be closed by a plug and new connecting bores can be arranged. Thus, this constructional form is very adaptable.
Whereas in the constructional example shown in FIG. 7 and FIG. 6 the bores 14 are situated in a line adjacent to one another, these bores 14 in the constructional example shown in FIG. 8 are arranged in a circle; in FIG. 8 the connecting bores 15 then have to lead radially outwards.
In the constructional example shown in FIG. 9 and FIG. 10 the insert element 12 has four bores 14 which extend over the entire width of the roll. The insert element 12, however, is inserted with a fit in the supporting member 3 and a separate connecting bore 15 is provided for each supporting element 2. The portions of the insert element 12 which are situated between the connecting bores 15 in this case form the "partition walls" in the sense of the present invention. By appropriate opening or closing of the connecting bores 15, these partition walls can be displaced, or, in other words, the position of these partition walls can be modified along the series of supporting elements.
The constructional form shown in FIG. 9 and FIG. 10 has the further advantage that not only one series of supporting elements can be connected to the four bores 14, but a second series of supporting elements 2' can also be connected to the same bores. Accordingly in FIG. 9, the three supporting elements 2' situated at the right in the illustration are connected to a conduit 14 which conducts pressure medium to these supporting elements. The other supporting elements 2' and the supporting elements 2 situated opposite the three supporting elements 2' supplied with pressure medium, however, are connected to a bore 14 which leads to a pressure fluid outlet. The other supporting elements 2 which are shown are connected by connecting bores to conduits 14 in which pressure fluid is supplied. In this way only the first seven supporting elements 2 situated at the left in the illustration press the shell 1 of the roll against the associated opposite roll which is not shown here, whilst the three supporting elements 2' at the right in the illustration press the shell 1 away from the aforesaid associated roll.
In the constructional example shown in FIG. 11 the insert element 12 is constructed to be capable of rotating. In the illustrating position, the roll operates with the same supply as the roll shown in FIG. 9 and FIG. 10. If the insert element 12 is turned in the counter-clockwise direction in the drawings, the two supporting elements 2 and 2' which are illustrated are connected to other bores 14 than in the constructional example shown in FIG. 9 and FIG. 10. Thus the insert element 12 can comprise a plurality of series of connecting bores 15 which open along a generatrix, and which are brought into connection selectively with the supporting elements 2 and 2' respectively by turning the insert element 12. Thus the load pattern of the roll can be modified by simply rotating the insert element 12.
The constructional example shown in FIG. 12 to FIG. 14 corresponds, as regards the guiding of the pressure fluids, substantially to the constructional example which was shown in FIG. 4 and FIG. 5. However, the partition walls 5 1 and 5 2 can be displaced from the outside. The partition wall 5 1 is secured to two tubes 16 1 which run in sealing-tight fashion through the cover 8 of the supporting member 3. The partition wall 5 2 is secured to two tubes 16 2 which run in sealing-tight manner through the partition wall 5 1 and in sealing-tight manner through the cover 8 of the supporting member 3. The tubes 16 1 advantageously are all of the same length corresponding to the width of the roll, so that the partition walls 5 1 and 5 2 can be adjusted over the entire width of the roll, and the ends of the tubes 16 1 and 16 2 projecting from the roll give a representation of the position of the partition walls 5 1 and 5 2 . Finally, the ends of the tubes 16 1 and 16 2 are connected by means of mobile flexible tubes to a pressure medium source 17.
In the constructional example shown in FIG. 15, an insert element 12 is arranged in the supporting member 3 and comprises helical partition walls 5 1 and 5 2 which can be displaced along the series of supporting elements by rotating the insert element 12.
The constructional example shown in FIG. 16 corresponds substantially to that shown in FIG. 1. But the spindle 7 is replaced by a square section rod 18 and the screwthread is arranged on the periphery of the partition wall 5. Correspondingly, the bore 4 of the supporting member 3 is constructed as a screwthreaded bore in which the screwthred of the partition wall 5 engages.
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Deflection control device, having a stationary supporting member; said supporting member comprising a series of hydrostatic supporting elements; said device also having a shell movable transversely in relation to the series of said supporting elements; ducts being provided in said supporting member for supplying or discharging pressure fluid for said supporting elements; a partition wall separating two of said ducts from one another; the position of said partition wall being variable along the series of said supporting elements.
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FIELD OF THE INVENTION
The present invention generally relates to a high-speed film scanner, and more particularly to a film code reader assembly installed in a film scanner for reading film codes inscribed along either one of two film edges in the film scanning direction.
BACKGROUND OF THE INVENTION
Several major technological advances have resulted in significant changes in equipment and operating procedures of commercial photofinishing systems. In the past, a customer's exposed film would be dropped off or mailed to a photofinishing center, where the film was developed, and photographic prints were then produced by printing the image frames on the developed photographic negative onto photographic paper in a multi-step optical projection sequence. As technology advanced, analog images could be transformed into digital image information by various optical scanning means. The ability to render photographic images in digital form accelerated the evolution of processes and materials which became advantageous for recording the digital information of the images on the film on a variety of media and by an assortment of techniques. For example, digital image information can now be recorded on optical disks or photo compact discs, as well as on photographic paper by devices such as digitally addressable high-speed laser printers.
It is these rapidly advancing technologies which have had a significant impact on commercial photofinishing operations. Today, a photofinisher will develop films from many customers and splice these films together so as to form a single large reel of spliced film to be deployed as a film supply reel in a high-speed film scanner. All individual sections of film on such a reel are of one and the same nominal width, for example, 35 mm film, but are typically of different section length, for example, 12 exposures, 24 exposures, or 36 exposures. Individual film sections may have a particular film speed rating (for example, ASA 100 to ASA 1000) and frequently include films by different manufacturers. Film manufacturers have established on a worldwide basis standards and specifications for splicing of films and splicing tolerances, i.e., the degree of allowable lateral offset at the splice of spliced sections perpendicular to the length of the spliced film, as well as allowable angular deviations among two adjacent spliced film sections.
When the very first splice joins two film sections such that the last frame of the first section joins the first frame of the second section, all subsequent film sections are spliced in the same manner, thereby providing a film supply reel with a "first frame first" (F.F.F.) configuration. When the first splice joins the first frame of the first film to the last frame of the second film, the completed film supply reel is said to be in a "last frame first" (L.F.F.) configuration. With respect to the emulsion face of film image frames, all optical film codes along one edge of each film section will be presented at one side for F.F.F. and the opposite side of the film for L.F.F. along the film path in a film scanner.
Suitable optical codes reflective of these film parameters are encoded during the film manufacturing process alongside each image frame of a film in proximity to one edge of the film. Thus, each image frame of a section of spliced film on a film supply reel can, in principle, be uniquely identified by its optical code as to film manufacturer, film speed rating, and number of frames on that film section. In the present invention this identification of image frames is performed by a film code reader assembly which is deposed in a film scanner at a location between the film supply reel and the film scanning module.
SUMMARY OF THE INVENTION
It is the principal object of the invention to provide a film code reader assembly in a film scanner to read optically readable film codes at uniform film screening speed.
Another object of the present invention is to provide a self-alignment feature for a film code reader of the film code reader assembly so as to maintain alignment of the code reader in response to positional variation of the scanning film in a direction perpendicular to the film scanning path within the film code reader.
A further object of the invention is to provide a pivotably rotating orientation means for orienting the film code reader with respect to the code-bearing edge of the film.
A still further object of the present invention is to provide a film path defining means within one film code reader member for effecting accurate film guiding past a film code reading location in the film code reader at uniform film scanning speeds.
These and other objects, features, and advantages are achieved in a film code reader assembly having the following major components with their associated functions:
mounting means for mounting the film code reader assembly to a mounting surface within a film scanner housing along the film path within the scanner at a position between a film supply reel and a scanning unit;
film code reading means defining a code reading location;
film path defining means for defining the path of the scanning film at the code reading location;
self-alignment means for maintaining alignment of the film code reading means in response to positional variation of the scanning film in a direction perpendicular to the scanning direction; and
pivotably rotatable orienting means for orienting the film code reading means with respect to the one film edge having the film code.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood and appreciated more fully from the following detailed description, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic diagram of a high-volume film scanner, showing the film code reader assembly (FCRA) in accordance with the present invention, located between a film supply reel and a scanning unit;
FIG. 2 is an exploded perspective view of the components of the film code reader assembly of the present invention:
FIG. 3 is a perspective view of the film code reader assembly in accordance with the present invention, shown assembled and operating in a "last frame first" mode;
FIG. 4 shows the film code reading assembly in accordance with the invention, and operating in a "first frame first" film scanning mode;
FIG. 5 is a perspective view of a second film code reading member of the film code reading assembly of the present invention, showing the major components of the film path defining means and an open door position to facilitate insertion and removal of film from this member:
FIG. 6 provides a view similar to that shown in FIG. 5, but with the door closed, thereby indicating the film path defining function of the set of edge-guide bearings deposed in the door;
FIG. 7 is a partial break-away perspective view of a first and a second film code reading member in accordance with the invention, showing particularly the spring-urged mounting of the light sensor at its triangularly-shaped mounting surface in a recess within the first film code reading member;
FIG. 8 is a partially exploded perspective view of the second film code reading member of the film code reader assembly in accordance with the invention, indicating particularly the optical components inserted into this member on a common optical axis;
FIG. 9 is a cross-sectional side view of the film code reading means in accordance with the invention, as seen by cutting through the center of the common optical axis with a plane 9--9 in FIG. 3;
FIG. 10 is a perspective view of the first film code reading member in accordance with the present invention, as seen film the film gap between the first and second film code reading members; and
FIG. 11 is a perspective view of the pivot block, showing the bore and the semi-circular locator pin guide channel with end stops, in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is indicated schematically a high-volume, automated film scanner, such as may be employed in large-scale photofinishing operations. The film scanner is contained in a housing 1 and has the following major components: internal mounting surfaces 2A, 2B, 2C, and 2D provide for mounting the components of the scanner. The scanner may also have a front or side access door. A film supply reel 3 supplies spliced film 4 along a film path 5 over an assembly of rollers 6 to the film code reader assembly (FCRA) of the present invention, to a film scanning station or unit, to a capstan film drive module 8, and finally to a film take-up reel 10. Film guide rollers 6 may be tensioned by a tensioning means 9.
Film supply reel 3 contains a large number of spliced films of nominal constant width, but of varying film length, film sensitivities or film speed ratings, and from various manufacturers. At the beginning of the reel is a leader (not shown) without image frames which is inserted along the film path 5 through the various components and brought to the take-up reel. At the end of the film supply reel 3 is an equally long film trailer (not shown). Operationally, the film scanner functions in two sequences: first, the entire film on supply reel 3 undergoes a relatively rapid, so-called, pre-scan whereby the film code reader reads all the film codes along one edge of each frame of the film, and providing digital signals representative of the film codes to signal storage means exterior of the scanner. At the same time, the scanning unit 7 performs a pre-scan over a central portion of each image frame on the passing film, so as to determine average light levels as might result in accordance with varying optical densities of each frame. Those light level determinations are stored as digital electronic signals in separate storage means. This pre-scan function occurs at typical film scan speeds in the range of 4-8 inches per second (10-20 centimeter per second). Upon completion of the pre-scan, the film is rewound from take-up reel 10 onto supply reel 3, during which both the film scanner unit 7 and the film code reader assembly are electrically deactivated. On a second pass, namely the main film scanning operation, the film code reader is electrically deactivated, previously stored film code data now being used to identify the appropriate film frame and associated parameters in the final image scan in the scan unit 7. This final image scan occurs while each frame remains temporarily stationary in the scanning gate of the film scan unit 7.
Referring now to FIGS. 2, 3, and 4, there are shown the major components of the film code reader assembly in the exploded view of FIG. 2, and the completed assembly in a "last frame first" and a "first frame first" mode in FIGS. 3 and 4, respectively. Film code reader assembly FCRA has a mounting arm generally designated at 20 having a first portion 21 mounted to the internal mounting surface 2B in FIG. 1 by suitable means at locations 27 and 28. A second portion 22 of the mounting arm 20 serves to fasten a top guideshaft 31 and a parallel bottom guideshaft 32 at their respective ends 33 and 35 to arm portion 22 by seating in bores 23 and 25, the shafts being retained in the bores by retaining screws 24 and 26, respectively. A pivot block 40 contains two linear bearings 41 and 42, as well as a roller bearing 43. Pivot block 40 is axially and slidably inserted over the top and bottom guideshafts 31 and 32, whereupon an end block 37 is attached to guideshaft ends 34 and 36 by retaining screws 38 and 39, respectively, so as to confine these latter guideshaft ends and thereby retain the guideshafts in a parallel position. The pivot block 40 is also attached to a film code reading member 60. The axially slidable pivot block 40, together with guideshafts 31 and 32 is generally indicated at 30, and constitutes a self-alignment mechanism whereby the pivot block 40 can slide readily along guideshafts 31 and 32 in response to sideways displacement or motion of film 4, and hence of film code reading members 70 and 60, caused by non-uniformities of the film splices.
Another function of pivot block 40 is to rotatably pivot about a pivot shaft 51 between two end positions 58 and 59 along a semi-circular locator pin guide channel 54, the guide channel being slidably engaged by a locator pin 53 which is deposed on a first member of the film code reader 61. Shaft 51 slidably extends through a central bore 50 and bushing 52 in pivot block 40, and shaft 51 is axially retained in pivot block 40 under the urging of a spring 55 by an end cap 56 and a shaft retainer 57.
Functionally the pivot block 40 has the previously indicated axial alignment capability and additionally allows for a rotational orientation of the film code reader between either of two positions at the termination of a 180° rotation.
As shown in FIGS. 3 and 4, rotation of pivot block 40 provides for reading a film code on films supplied by the film supply reel 3 in FIG. 1 either in a "last frame first" mode or in a "first frame first" mode.
The film code reader sub-assembly has two major components, namely a first film code reading member generally designated at 60 and a second film code reading member generally designated at 70. First film code reading member 60 has a structural frame 61 and mounting means 62 and 63 for fixedly attaching first film code reading member 60 to the structural frame 71 of second film code reading member 70. Additionally, film code reading member 60 has fixedly attached thereto both the pivot arm shaft 51 and the pivot locator pin 53. Film code reading member 60 also contains a light sensor in a recess behind cover plate 64, this light sensor detects film code optical signals transmitted through the scanning film by a light source contained in flint code reading member 70. Attachment of film code reading member 60 to film code reading member 70 by means of attachment screws 65 and 66 is performed in such a manner as to establish a clearance or a gap between the two opposing surfaces of film code reader frames 61 and 71, respectively.
Within film code reading member 70 is contained a film path defining means generally indicated at 80. The film path 5 of the scanning film 4 is defined in the scanning direction by an entrance film guide roller 81 mounted to the frame 71 by mounting means 88, and an exit film guide roller 82 deposed on frame 71 by mounting means 89, as shown in FIG. 3. Furthermore, a recessed convexly curved surface 91 (FIG. 5) inside film code reading member 70 provides in conjunction with two convexly curved film path rails 92 (FIG. 5), 93 adjacent to film edges 4A and 4B, a smooth motion of film along the scanning direction (see FIGS. 5 and 6 for details). Moreover, this arrangement provides beam strength across the width of the flint to properly position the film relative to rollers 83A and 83B. Confinement and film guiding in a direction perpendicular to the film scanning direction is achieved by two opposing sets of film edge guide bearings 83A and 83B, and 84A and 84B, respectively. A more detailed rendition of these sets of film edge guide bearings can be seen in FIGS. 5 and 6. Film guide bearing set 84A and 84B is deposed within a pivotable door 86 pivoting about a pivot mount 85, and being urged by a spring 90 (see FIG. 5). Precise positioning of the set of film edge guide bearings 84A and 84B relative to either of the film edges 4A or 4B is accomplished by an adjustment screw 87 which extends through door 86 against an interior surface of film code reading member 70.
Referring now particularly to FIGS. 5 and 6, there is shown in FIG. 5 the open door position of pivotable door 86, thereby facilitating the insertion and removal of non-scanning (stationary) film into and from the film path defining guide mechanism. Also shown in FIGS. 5, 6 are raised convexly crowed film path rails 92, 93 and a recess 100 at the zenith of curvature of film path rail 93, having an aperture 101 at its base. The recessed convexly curved surface is indicated at 91. Aperture 101 provides a well-defined beam of light to the scanning film at the code reading location from a light source 104 through a second aperture 105 and a lens element 107A contained in a lens barrel 107B, all these elements being centered on a common optical axis 102 (see FIGS. 8 and 9 for details).
Thus, each one of film code reading members 60 and 70 accomplishes specific and unique objectives: film code reading member 60 contains the light sensor which transforms optical film code signals into electrical signals for storage and processing exterior to that member. Film code reading member 60, fixedly attached to member 70 (with a gap therebetween) also serves as a structural member to provide both, a self-alignment capability of the film code reader in response to positional variation of the scanning film in a direction perpendicular to the scanning direction and a pivotably rotatable orienting capability for orienting the film code reader with respect to the one film edge carrying the film code ("first frame first" and "last frame first" modes of operation).
Film code reading member 70 provides an accurate film path and film guiding at relatively high film scan speeds, and assures a well-defined beam of light to be incident upon the film code of the scanning film at the code reading location. Furthermore, a pivotably opening and closing door facilitates the insertion and removal of film into and from member 70 in the non-scanning mode, and provides in that door a set of film edge guide bearings.
Referring now to FIG. 7, there is provided a partial cross-sectional perspective view of film code reading members 60 and 70, showing the mounting of light sensor 108, with cover 64 removed from the back side of housing 61. Vertical side walls 122 and 123 meet at a corner (not shown) to form a fight angle recess. Attached to the back side of light sensor 108 is a right angle triangular plate 109 which also has vertical side walls (not shown) emanating from the right angle. The hypotenuse of that triangular plate 109 has an upwardly sloped wall face 109H. The light sensor 108 is secured in three orthogonal directions (namely against the vertical side wall recesses and pressed downwardly in the third orthogonal direction) by a spring 120 having a protrusion 121 pressing against sloped hypotenuse wall 109H. Spring 120 is fixedly held on the upper surface of housing or frame 61 by pivot locator pin 53. Of course, other mounting arrangements can be envisioned for mounting spring 120 to housing or frame 61 of film code reading member 60.
Referring now to FIG. 8, there is shown a perspective view of film code reading member 70, as seen from the light source 104. Housing or frame 71 has an opening 72 which is covered by a cover (not shown) when the optical elements are fully assembled into housing 71. The previously mentioned aperture 101 at the base of recess 100 in film guide rail 93 is shown centered on a common optical axis 102 together with a light-emitting diode light source 104, an optical aperture element 105, a coil spring 106, and a lens 107A (see FIG. 9) in a lens barrel 107B. Upon attachment of circuit board 73 at mounting surfaces inside housing 71, the lens 107A within lens barrel 107B will be properly positioned with respect to aperture 101 to provide the highest possible defined illumination at the film code reading location. Furthermore, coil spring 106 urges the aperture 105 against the front surface of the light-emitting diode light source 104, and the spring urges lens barrel 107B toward aperture 101. Also shown in FIG. 8 is a connector block 103 attached to circuit board 73. Extending from connector block 103 are two sets of electrical connections, electrical connections 150 leading to electrical circuits exterior of film code reader assembly, and electrical connections 140 which extend from connector block 103 to the photosensor in film code reading member 60. The light-emitting diode light source 104 is also attached to connector block 103.
Referring now to FIG. 9, there is shown a cross-sectional side view of the film code reading members 60 and 70. At the zenith of convexly crowed film path surface of rail 93 of film code reading member 70 is depicted the recess 100 with its associated aperture 101. On film code reading member 60 is provided a recess 110 on planar surface 112, this recess leading to aperture 111 and from there to the light-sensing surface of light sensor 108. All optical elements, namely light-emitting diode light source 104, aperture 105, lens barrel 107B containing a lens 107A, as well as aperture 101, recess 100, recess 110, aperture 111, and light sensor 108 are on the common optical axis 102. The gap between film code reading member 70 and film code reading member 60 is indicated in FIG. 9. Film 4 is shown to enter the film code reader through entrance film guide roller 81, thereupon following the path of the convexly curved surface 91 of film code reading member 70 and exiting the film code reader at exit film guide roller 82.
Emanating from connector block 103 are schematically indicated electrical connections 150 connecting to electrical signal storage means and electrical supply means exterior to the film code reader assembly, and electrical connections 140 which are connected through the film code reader outside the film scanning surface to light sensor 108.
Referring now to FIG. 10, there is shown film code reading member 60 as viewed from the film path surface of film code reading member 70. On the planar surface 112 and along the common optical axis 102 are indicated a recess 110 and centrally located therein an aperture 111 on frame or housing 61 of film code reading member 60.
Referring now to FIG. 11, there is shown a view of pivot block 40 as seen from film code reading member 60 in the direction of pivot arm shaft 51 (see FIG. 2). Semi-circular pivot locator pin guide channel 54 terminates in end positions 58 and 59. Pivot locator pin 53 (see FIG. 2) slidably engages guide channel 54 and end stops 58 and 59, thereby assuring pivotably rotatable orientation of film code reading members 60 and 70 with respect to the film code bearing edge in the "first frame first" and "last frame first" film scan mode or configuration. The 180° semicircular guide channel 54 ensures that the flexible electrical connections 150 (see FIGS. 8 and 9) will not be continually twisted in the same direction.
From the foregoing detailed description, it will be apparent that a film code reading assembly has been provided which mounts the film code reader assembly in suitable relationship to a film scanning unit of a film scanner, and which has a defined film code reading location. The film code reader assembly of the invention further defines the path of the scanning film at the film code reading location, as well as self-alignment capability of the film code reader in a direction perpendicular to the direction of the scanning film. Additionally, the film code reader assembly of the invention provides pivotably rotatable orienting arrangement for orienting the film code reader with respect to that film edge which carries the film code. Variations and modifications of the film code reader assembly within the scope of the invention will undoubtedly suggest themselves to those skilled in this art. Accordingly, the foregoing description should be taken as illustrative and not in a limiting sense.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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A film code reader assembly for a film scanner provides film path for accurately guiding the scanning film past a film code reading location where optically readable film codes are extracted by a code reader. The assembly self-aligns the film code reader in a direction perpendicular to the scanning direction of the film, and orients film film code reader with respect to the film code-bearing edge of the scanning film.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an electronic musical instrument which generates parameters specifying a musical tone wave form and controlling a musical tone wave form generation with the aid of a neural network.
2. Description of the Prior Art
The parameters to control the musical tone in the electronic musical instrument are a wave form data which specifies the wave form of the musical tone, an envelope data which specifies an output level of the musical tone wave form, a pitch data which specifies a tone pitch, etc. Several musical tone parameters are stored in a memory of the electronic musical instrument, and can be freely read by a player to play, varying expression. A part of the musical tone parameters is previously stored in the memory of the musical instrument before shipping thereof, and remaining another part of the musical tone parameters can be stored in the memory before the player plays the instrument.
The musical tone parameters stored in the memory in advance can be freely selected for playing by the player while playing the instrument. However, the parameters not stored in the memory cannot be selected. It takes too much time to set new parameters while the player plays the musical instrument, so that this setting was impractical. As a result of this the parameter selection range is too narrow, and play expression is poor.
If more musical tone parameters are stored in the memory for widening the selection range, larger memory is required and it takes much time to store the parameters.
The FM (Frequency Modulation) tone source is one of the conventionally applied tone sources to the electronic musical instrument. The FM tone source synthesize a musical tone by combining (modulating and adding) four or six operators each of which can be set basic wave form (sine wave, triangle wave, etc.), frequency (tone pitch), out put level, envelope, etc. based on a specific algorithm. This tone source can generate beautiful and varied musical tones with simple configuration.
However, it has been regarded that it is difficult to generate the musical tone using the FM tone source according to player's intention. This is mainly due to that it is difficult to predict the change of the musical tone based on the change of the operator and the algorithm since the musical tone is generated by using many parameters and FM modulation.
An example is an electronic musical instrument which is designed to set the pitch of the musical tone to be generated according to ON/OFF pattern of several play keys such as electronic musical wind instrument. Generally, such an electronic musical instrument is provided with a table which stores the pitch data corresponding to several ON/OFF patterns. This table is retrieved according to the ON/OFF pattern by player's operation to find the specific pitch.
In such electronic musical instrument, the ON/OFF pattern of the playing keys can set only the pitch, but the tone color (wave form) of the musical tone was constant irrespective of pitch. In case of natural musical instrument the tone color (wave form) varies delicately depending on the pitch even when the musical instrument (tone color) is the same, and this delicate change of the tone color affects significantly expression of the musical instrument. Moreover, even when the pitch is constant, the tone color changes if fingering pattern is changed. So as to change the tone color as discussed above on the electronic musical instrument, generally, it is necessary to sample the wave form of natural musical instrument for each ON/OFF pattern of the keys and for each pitch and to read out a wave form data. However, these wave form data for each pitch need a large memory capacity to store them, due to which the size of the musical instrument is increased, and its cost rises.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a musical tone parameter generating method which has solved the above-mentioned problems by generating also the unstored parameters with the aid of a neural network.
The second object of the present invention is to provide an electronic musical instrument which is provided with a musical tone generating device capable of generating easily the musical tone as imaged with the aid of the neural network which infers and outputs the wave form specifying parameters based on several image parameters expressing the features of tone color.
The third object of this invention is to provide an electronic musical tone generating device in which the above-mentioned problems have been solved by inferring and setting the wave form with the aid of the neural network.
The musical tone parameter generating method of this invention features that the neural network learns the input pattern and the musical tone parameter of an expected output which correspond to each other. Because such a neural network is provided, any value other than that of the musical tone parameter stored previously in the memory can be got freely, which enhances expression ability and saving of memory.
The above-mentioned neural network learns several combinations of the input patterns and the musical tone parameter patterns according to an algorithm such as back propagation. Consequently, when the learnt input pattern is inputted, the musical tone parameter pattern corresponding thereto is outputted. Even when any pattern not learnt is inputted, a new musical tone parameter pattern is outputted as a result of associative compensation with the aid of synapse joint of the neural network, which affords possibility of new musical tone expression and enables to save the time for pre-setting the musical tone parameter and the memory to store many musical tone parameters.
The musical tone generating device of this invention functions as follows. Several operators are generated based on several wave form specifying parameters. A musical tone is generated by synthesizing such operators according to a specific algorithm. The wave form specifying parameter for generating the musical tone and the synthesis algorithm are inferred and outputted by the neural network.
Entry for the inference is an image parameter. Applicable image parameters are, for example, tone hardness/softness, showiness/quietness of tone, beauty/dirtiness of tone, thickness/thinness of tone, etc. The neural network learns previously so that the wave form specifying parameter which causing ordinary player's imaging musical tone is outputted. Consequently, proper image parameters input allows of suiting generation musical tone to that image parameters.
Moreover, the electronic musical instrument of this invention features that by inputting the combination (ON/OFF pattern) of play keys into the neural network the data which specifies the wave form of the musical tone is outputted. As the data, the tone color can be inferred and outputted simultaneously in addition to the tone pitch. If this neural network learns, for example, so as to associate tone color change according to the .key ON/OFF pattern of a natural musical instrument, it is possible to infer all tone color patterns of the whole tone range with the aid of one set of synapse weights data. In case of a harmonics synthesis type tone source circuit which is designed so that the musical tone wave form is generated by additively synthesizing a sine wave, the result of Fourrie analysis can be used directly as neural network learning data, if the neural network can output the ratio of harmonics component, thereby facilitating remarkably the embodiment. It is allowed to set also the pitch simultaneously in the neural network. It is also allowed to set the pitch with another means (table, etc.) and to change the frequency of tone color wave which is inferred by the neural network.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of control section which is an embodiment of this invention.
FIG. 2(A) shows a partial configuration of the ROM of the control section.
FIG. 2(B) shows a partial configuration of the RAM of the control section.
FIG. 3 shows a configuration of a neural network which is arranged in this control section.
FIGS. 4 (A) to (F) are flow charts showing the operation of the control section.
FIG. 5 is a block diagram of control section of an electronic musical element which is another embodiment of the invention.
FIG. 6 shows a configuration of a neural network which is used in the control section.
FIG. 7 is a block diagram of control section of an electronic musical instrument which is also an embodiment of the invention.
FIG. 8 shows an approximate configuration of a playing unit, a neural network and a tone source circuit of the electronic musical instrument.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a block diagram of an electronic musical instrument employing the musical tone parameter generating method which is an embodiment of this invention. This electronic musical instrument is an electronic keyboard type musical instrument having a playing keyboard 16. A tone generator 14 generates the musical tone whose pitch is specified by the playing keyboard 16. A wave form of the musical tone to be generated is generated by a neural network. Namely, in this electronic keyboard type musical instrument the musical tone wave form (plotted amplitude level train) is generated by the neural network. For software configuration of the neural network, a CPU 10 is used. Inter-neuron synapse weights are stored in a memory. The CPU 10 which is designated to perform neural network operation and control, a ROM 12 which stores control program, and a RAM 13 which stores synapse weights are connected through a bus 11, through which data is transmitted and received. The tone generator 14, a function switch group 15, a keyboard 16, a display 17, and a wave form inputting device 18 are connected to the bus 11. The tone generator 14 has several tone generating channels which can operate individually. It generates musical tone whose pitch is specified by the keyboard 16. A sound system 19 is connected to this tone generator 14. The musical tone generated by the tone generator 14 is amplified and outputted from a speaker. The function switch group 15 has a wave form number inputting means, a vector specifying means, a preset mode switch, a learning mode switch, and a registration mode switch. The keyboard 16 has 61 (5 octaves) keys. The display 17 consists of a liquid crystal matrix indicator which displays specified vector value and wave form. The wave form inputting device 18 is a sampling device which converts the musical tone wave form inputted from a microphone into PCM (Pulse Coded Modulation) which is stored in a memory.
FIG. 2 (A) shows a partial configuration of the ROM 12. M1 is a preset wave form memory area, and M2 is preset synapse weights memory area. The preset wave form and the preset synapse weights are stored in advance in these memory areas. When the player enters a wave form number in the preset mode, a pertinent wave form is read from the preset wave form memory area, and sent to the tone generator 14. When the player enters a vector value in the preset mode, the CPU 10 performs neural network operation to determine the output pattern based on the preset synapse weights and outputs data.
FIG. 2 (B) shows a partial configuration of the RAM 13. M3 is a user-set wave form memory area, and M4 is a user-set synapse weights memory area. The wave form data and the synapse weights to be stored in these areas are written by the user of the electronic musical instrument.
The following flags and registers are set in the RAM 13.
PRI: Preset Mode Flag: Flag to be set in the preset mode.
ST: Learning Mode Flag: Flag to be set in the learning mode.
REG: Registration Mode Register: Flag which is set when a sampling wave form is inputted from the wave form inputting device 18 and is reset when this wave form is stored in the specified user-set wave form memory area.
BUF: Wave form Buffer: Buffer which stores temporarily the wave form which is sampled by the wave form inputting device 18.
VEC: Input Vector Register: Register which stores temporarily the vector value inputted from the vector specifying means.
WEV: Wave form Number Register: Register which stores temporarily the wave form number inputted from the wave form number inputting means.
FIG. 3 shows a concept of the neural network. This neural network is a hierarchy neural network. It comprises an input layer, an intermediate layer and an output layer, each of which consists of several neurons. The input layer consists of 5 neurons, I1 to I5. It can accept five dimensions vector (input pattern), each term of the vector may be any real number. Tone color image data can be used as the vector. Each neuron of the input layer is synapse-jointed to all neurons of the intermediate layer. The joint strength is determined by synapse weights w. The intermediate layer consists of m neurons N1 to Nm, and each neuron is synapse-jointed to all neurons of the output layer. The output layer consists of n neurons O1 to On, and each neuron corresponds to the amplitude of each timing of the musical tone wave form. Namely, the musical tone wave form can be formed by plotting the output value of the specific each neuron O1 to On in time series.
FIGS. 4 (A) to (F) are flow charts showing the operation of the control section. FIG. 4 (A) shows a main routine. In this main routine, at first initializing such as register reset, etc. is performed after power turning-on (n1), so that the electronic musical element is made ready to play. Then, the function switch and the keyboard operations are detected to execute the corresponding processing (n2, n3).
FIG. 4 (B) shows the preset mode switch ON event operation. When the preset mode switch is turned on, the preset mode flag PRI is inverted (n4). If PRI is set as a result of this inversion, the preset mode lamp is lit since the current mode is the preset mode to specify the wave form with the aid of data such as preset (stored in The ROM12) synapse weights, etc. (n6). In the case when PRI is reset, the preset mode lamp is turned off (n7), since the current mode is the user-set mode where the user uses the learnt data.
FIG. 4 (C) shows the learning mode switch ON event operation. This learning mode switch is operated when the relation between the vector and the output wave form is taught to the neural network. When the learning mode switch is turned on, the learning mode flag ST is inverted (n8). If ST is set as a result of this inversion, the learning mode is started. Therefore, the vector register VEC and the wave form number register WAV are cleared (n10), the learning mode lamp is lit (n11), and then the process returns. If ST is reset as a result of inversion, teaching to the neural network is executed by making the vector value stored in VEC to correspond to the wave form data of wave form number stored in WAV (n12). Accordingly, the vector value is an input pattern and the wave form data is an expected output pattern corresponding to this input pattern. These data, the vector value and the wave form data, are set in the registers VEC and WAV as described later in FIG. 4 (E) and FIG. 4 (F). The wave form data includes, for example, an attack part, a sustain part, and a decay part of the wave form of a piano tone. In the learning mode, the neural network is learned as follows.
First, a vector value and a wave form data corresponding to the attack part are inputted and set into the above registers VEC and WAV. Therefore the learning process is performed.
Second, a vector value and a wave form data corresponding to the sustain part are inputted and set, therefore the learning process is performed.
Third, a vector value and a wave form data corresponding to the decay part are inputted and set, therefore the learning process is performed.
According to the such learning process, a smooth varying piano tone is simulated by gradual varying of the vector value.
The above learning process is executed according to the back propagation system. After that the learning model lamp is turned off (n13), and the process returns.
FIG. 4 (D) shows registration switch ON operation. This is an operation to sample the musical tone wave form from the wave form inputting device 18. When the registration switch is turned on, this operation is started. It is repeatedly executed while the switch is kept turned on. At first, at step n14 the address to specify the area of the wave form buffer is reset. Buffer data read/write operation is executed according to this address. Then, the musical tone data (instantaneous value) of specific timing is fetched from the wave form inputting device 18, and this data is stored in the buffer (n16). After that, a judgment as to whether or not the registration switch is ON is executed (n17). If this switch is ON, the address is updated (n18), and the process returns to the step n15. If the registration switch is OFF, sampling is ended. Namely, the process proceeds from the step n17 to the step n19, the registration model flag REG is set, and then the process returns.
FIG. 4 (E) is a flow chart showing the processing when the vector number is inputted. When the vector number is inputted, this value is stored in the input vector register VEC (n21), and a judgment as to whether the preset mode flag PRI and the learning mode flag ST have been set or reset is executed (n22, n23). If PRI has been set, the process proceeds from step n22 to step n24 where the wave form data is calculated by the neural network using the preset synapse weights and this vector value. This wave form is indicated (n25), and at the same time the wave form data is sent to the tone generator 14 (n26). If the learning model flag ST has been set, the vector to be learnt is regarded to have been inputted. This vector is indicated on the display 17, and the process returns (n30).
If both the PRI and the ST have been reset, the process proceeds to step n27 where the musical tone wave form data is calculated by the neural network using the user-set synapse weights. The wave form is indicated on the display 17 (n28) and sent to the tone generator (n29).
FIG. 4 (F) is a flow chart showing the operation which is executed when the wave form selection witch is set to ON. When the wave form selection switch is set to ON, ON wave form number is stored in the wave form number register (n31), and a judgment as to whether the registration mode flag REG and the preset model flag PRI have been set or reset is performed (n32, n33). If the REG has been set, the wave form data stored currently in the wave form buffer BUF is registered in the user-set wave form data memory area (n34). The registration area is an area identified by wave form number (WEV). After the REG is reset (n35), and the process returns.
If the PRI has been set, the wave form data stored in the area which is identified by the wave form number (WEV) in the preset wave form data memory area is sent to the tone generator 14 (n36). The musical tone is generated by this wave form data.
If both the REG and the PRI have been reset, data of the WEV is indicated on the display (n37), and the process returns. This operation is performed when the wave form is selected in the learning mode.
Thus, this electronic musical instrument features that since the input pattern and the expected output are learnt to the neural network in specific conformance, any value of the musical tone parameter other than that stored previously in memory can be got freely, delicate change of the musical tone parameter can be obtained thereby enhancing the expression. Moreover, since there is no need to store many parameters in memory, memory can be saved.
The above-mentioned electronic musical instrument has been designed so that the musical tone parameter pattern is generated through the neural network for the wave form data. The same processing can be performed also for other musical tone parameters.
FIG. 5 is a block diagram showing the control section of an electronic musical instrument which is an another embodiment of the invention. This electronic musical instrument is controlled by a CPU 20 and generates a musical tone according to operation of a player. The CPU 20 is connected to specific circuit through a bus 21. The provided circuits comprises a ROM 22, a RAM 23, a neural network (NN) 24, a keyboard 25, an operation panel 26, and a FM sound tone circuit 27. A sound system 28 designed to amplify the generated musical tone and output it through a speaker, etc. is connected to an FM tone source circuit 27.
The ROM 22 stores a program and preset synapse weights. The RAM 23 has registers to store various data which are created during playing and stores the synapse weights which is obtained as a result of learning by user. The neural network 24 has a function to decide the wave form specifying parameter int eh FM tone source based on an inputted image parameter. This neural network 24 is a hierarchy neural network as shown in FIG. 6. The image parameter is inputted into an input layer from tone color image specifying dials 26a to 26d. The wave form specifying parameter as shown in FIG. 6 is outputted to an output layer according to inference based on this parameter. Any hardware configuration is applicable for the neural network provided that the hierarchy inference as shown in the figure is possible. The keyboard 25 is for playing and covers tone range of about 5 octaves. The operation panel 26 has a learning mode/normal mode selection switch, a synapse weights selection switch in addition to the above-mentioned tone color image specifying dials 26a to 26d. The learning mode is a mode in which an image for the currently set wave form specifying parameter is inputted with the aid of the tone color image specifying dials so that the tone color is learnt. The normal model is an ordinary play mode. The synapse weights selection switch is a selection switch to specify use of the synapse weights which are previously stored in the ROM 22 or use of synapse weights which are learnt in the above-mentioned learning mode and stored in the RAM 23.
The FM tone source circuit 27 is a circuit which specifies generation contents of 4 or 6 operators by settings several parameters, synthesize the musical tone according to the specified algorithm which designates the combination of operators and modification procedure. By properly adjusting the parameters and algorithm, complex changed tone colors and high-order harmonic overtones can be obtained. The parameters and the algorithm are set by the CPU 20 before playing. The musical tone of specific pitch is generated based on a key-ON signal and a key code sent from the CPU 20 during playing.
FIG. 6 shows an outline of the tone color image specifying dials 26a to 26d, as well as an outline of the neural network 24. The tone color image specifying dials 26a to 26d can set the extent of 4 types of tone color image. The dial 26a specifies hardness of tone (hard/soft). The dial 26b specifies tone thickness (thick/thin). The dial 26c specifies beauty of tone (beauty/dirt). The dial 26d specifies showiness of tone (showy/quiet). A value which is specified by the tone color image specifying dials 26a to 26d is inputted into the neural network 24 as image parameter. These 4 image parameters are inputted into the input layer of the neural network 24. Each neuron of the input layer and a joint layer is synapse-jointed with specific weighing, and each neuron of the joint layer and the output layer is also synapse-jointed with specific weighting. An output of specific neuron of the output layer corresponds to the wave form specifying parameter of specific operator and algorithm. For simpler explanation, FIG. 6 shows an operator ON/OFF, a frequency ration (pitch of musical tone to be generated with respect to frequency) and an envelope rate as the wave form specifying parameters of each operator. The real operator is specified by more parameters including musical effect parameter, such as a vibrato rate or a portamento. This output is sent to the FM tone source circuit 27 through the CPU 20, and the FM tone source circuit 27 generates the musical tone according to this parameter.
This neural network 24 learns previously several teach data. Proper output parameter can be set according to this learning irrespective of what parameter is inputted. Statistic data of unspecified many players are used as the teach data. The neural network is learnt so that it outputs the wave form specifying parameter which makes the FM tone source circuit 27 generate the musical tone suited to specified image by the tone color image specifying dial 26. This simplifies greatly tone generation.
Several sets of learnt the synapse weights to be stored in the RAM 23 applied in the above electronic musical instrument are applicable. Data of the musical tone to be learnt is allowed to be not the wave form specifying parameter which has been set in the electronic musical instrument but be data inputted from other equipment.
The musical tone generating device of this invention can generate the musical tone, using the neural network, so that the musical tone suited to image can be generated easily without operating complicated parameters. This simplifies, for example, a tone color edit of the FM tone source circuit.
The third embodiment of the invention is explained below by referring to FIG. 7 and FIG. 8.
FIG. 7 is a block diagram which shows a control section of the electronic musical instrument which is the 3rd embodiment of the invention. This electronic musical instrument is provided with a wind instrument type playing device (wind controller) 35 (see FIG. 8). It generates musical tone when a player blows. The whole operation is controlled by a CPU 30. The CPU 30 is connected to a ROM 32, a RAM 33, a neural network (NN) 34, an interface 39, an operation panel 36 and a harmonics additive type tone source circuit 37 through a bus 31. The above-mentioned wind controller 35 is connected to the interface 39. A sound system 38 to amplify a generated musical tone and to output it from a speaker is connected to a tone source circuit 37.
An operation control program and synapse weights corresponding to a musical instrument name chosen by the player are stored in the ROM 32. When the player chooses a musical instrument name, synapse weights corresponding thereto are read from this ROM 32 and set in the neural network 34. Several registers to store various data generated during playing are provided in the RAM 33. The neural network 34 executes an inference so as to decide a musical tone which must be generated according to the ON/OFF pattern of a key system 41 (see FIG. 8) of the wind controller 35. This neural network 34, as outlined in FIG. 8, is an hierarchy neural network. The ON/OFF signal of each key is inputted into each neuron of the input layer, and a frequency control signal of the harmonics to be synthesized and its amplitude control signal are outputted from the output layer. It is possible to use the neural network of any hardware configuration provided that the hierarchy inference as shown in the figure is feasible. Moreover, the Neumann type microprocessor is applicable if high speed inference processing is possible.
The wind controller 35, as shown in FIG. 8, is a wind musical instrument (recorder) type playing device. It controls tone generation/silencing and tone generation level according to an intensity of breath blown into a mouthpiece 40. The key system 41 is controlled by fingers of both hands of the player. The pitch of musical tone to be generated is decided by ON/OFF pattern of the key system 41. The operation panel 36 is provided with a tone color selection witch and a display. Tone source circuit 37 which is harmonics additive type is a tone source circuit which generates musical tone by adding sine waves of different frequencies to synthesize (generate) the musical tone as shown in FIG. 8 (right). Frequency and amplitude of the sine waves to be synthesized are inferred by the neural network 34.
FIG. 8 shows the approximate configuration of the wind controller 35, the neural network 34 and the tone source circuit 37 of the electronic musical instrument. The wind controller 35 has a shape similar to that of the wind instrument as shown in the figure. The player blows in breath from the mouthpiece 40, and controls the key system 41 with his fingers of both hands to play the instrument. Each key composing the key system 41 is an electronic switch. The ON/OFF signal caused by operation is given to the input layer 42 of the neural network 34 as an electric signal. The neural network 34 is a hierarchy neural network having 4 layers, namely an input layer 42, a 1st intermediate layer 42, a 2nd intermediate layer 44, and an output layer 45. The input layer 42 has the same number of neurons as the key system 41 and is connected to the 1st intermediate layer 44, with specific synapse weights. The 1st intermediate layer 44 and the 2nd intermediate layer 45 are also mutually connected with specific synapse weights, and the 2nd intermediate layer 44 and the output layer 45 are also mutually connected with specific synapse weights. The number of neurons of the output layer 45 is equal to the number of sine wave generating circuits 46 of the tone source circuit 37, or the number of distributors 47 of the tone source circuit 37. Each neuron of the output layer 45 outputs the frequency control signal of the sine wave to be generated to the sine wave generating circuit 46 and at the same time outputs a distribution rate (amplitude) control signal of the inputted sine wave to the distributor 47. The tone source circuit 37 comprises the above-mentioned sine wave generating circuit 46, the distributor 47, an adding circuit 48, and a ED/A converter 49. The sine wave generated by the sine wave generating circuit is restricted to the specified amplitude value by the distributor 47, and the restricted signal is inputted into the adding circuit 48. In the adding circuit 48 all the inputted sine waves are added to synthesize, and the obtained signal is inputted into the D/A converter 49. In the D/A converter 49 the inputted synthesis signal is shaped to give smooth envelop, and then the shaped signal is outputted. The outputted signal is the musical tone signal which is amplified by the sound system 38 and outputted herefrom.
Because the harmonics synthesis type tone source circuit is controlled by the neural network to generate the musical tone, it is possible to use the result of analysis by FFT (Fast Fourier Transformer) as teach pattern of the neural network. That is, musical tone of specific pitch of the musical instrument to be learnt is FFT-analyzed, and the result of FFT, to which the ON/Off pattern to generate the FFT-analyzed musical tone corresponds, is given to the neural network as the teach pattern. As above learning is performed for the whole tone range, it becomes possible to infer properly the musical tone of the whole tone range with one set of synapse weights.
The applicable tone source circuit is not restricted to the harmonics synthesis tone source circuit. FM tone source is also applicable. In this case the neural network outputs FM parameters specifying the music tone such as key level scaling parameter which enables operators of the FM tone source to vary generating sine wave according to a turned on key data (pitch data). And in this case the learning mode is performed by using pitch data and the key level scaling parameter.
It is allowed to include a blow intensity detected at the mouthpiece 40 in the input variables of the neural network 34. This makes it possible to infer simultaneously a change of tone color depending on the tone generation level.
Thus, this electronic musical instrument makes it possible to infer not only the pitch of the musical tone but also the tone color based on the ON/OFF pattern of several play keys. This enables the player to variegate the musical tone depending on the pitch similarly to the natural musical instrument, which enhances the expression of the electronic musical instrument.
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A musical tone parameter generating method and a musical tone generating device of this invention feature that when data inputted by a player is inputted into a neural network as input pattern, the neural network infers the parameters necessary to specify a musical tone wave form to be formed. This makes it possible to get parameters other than those stored in a memory by inferring, which increases variation of the musical tone to be generated.
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CLAIM OF PRIORITY IN PROVISIONAL APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 61/053,754 filed May 16, 2008, entitled, “Cryogenic Capable High Pressure Containers for Compact Storage of Hydrogen Onboard Vehicles” by Gene D. Berry et al, and incorporated by reference herein.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] The United States Government has rights in this invention pursuant to Contract No. DE-AC52-07NA27344 between the United States Department of Energy and Lawrence Livermore National Security, LLC for the operation of Lawrence Livermore National Laboratory.
FIELD OF THE INVENTION
[0003] The present invention relates to pressure vessels for fluid storage applications. More particularly, the present invention relates to cryogenic-capable high pressure containers for compact flexible storage of hydrogen onboard vehicles.
BACKGROUND OF THE INVENTION
[0004] Hydrogen as an alternative fuel to petroleum is well known, as well as its potential to reduce or eliminate petroleum dependence and associated tailpipe air pollutants and greenhouse gases. However, the predominant technical barrier limiting widespread use of hydrogen-powered vehicles is insufficient onboard fuel storage capacity for highway vehicles within volume, weight, cost, and refueling time constraints.
[0005] Three known technologies for automotive hydrogen storage include: high pressure compressed gas storage (CH 2 ), storage by low-pressure absorption of hydrogen in porous and/or reactive materials, and cryogenic storage as liquid hydrogen (LH 2 ). Each has its challenges. For example, one drawback of hydrogen stored as a compressed gas is that it occupies a relatively large volume at ambient temperature. For materials which absorb hydrogen, significant weight, cost, and thermal complexity is typically added to onboard storage systems. And LH 2 storage has the potential for evaporative losses from distribution, transfer and refueling operations, as well as from the venting necessary to relieve pressure buildup during periods of inactivity due to heat transfer from the environment. Because of the high sensitivity of LH 2 storage containers to heat transfer, high performance insulation has been used with typical thicknesses of 3 cm or more. Such evaporative losses are commonly associated with the use of conventional low-pressure cryogenic tanks consisting of a vessel for containing a cryogenic liquid, and a jacket spaced from and surrounding the vessel for thermal insulation.
[0006] One alternative to the use of conventional low pressure cryogenic tanks for LH 2 storage has been cryogenic-capable/compatible pressure vessels, such as disclosed for example in U.S. Pat. No. 6,708,502, incorporated by reference herein, for flexibly storing cryogenic liquid fuels or compressed gas fuels at cryogenic or ambient temperatures. The cryogenic-capable pressure vessel in the '502 patent has an inner pressure container enclosing a fuel storage volume, an outer container surrounding the inner pressure container to form an evacuated space therebetween, and a thermal insulator surrounding the inner pressure container in the evacuated space to inhibit heat transfer. Additionally, vacuum loss from fuel permeation is substantially inhibited in the evacuated space by, for example, lining the container liner with a layer of fuel-impermeable material, capturing the permeated fuel in the evacuated space, or purging the permeated fuel from the evacuated space. Cryogenic-capable pressure vessels like the one disclosed in the '502 patent are capable of storing hydrogen with far greater thermal endurance than conventional cryogenic tanks, more compactly than conventional ambient temperature pressure vessels, and with lower weight than hydrogen absorption storage technologies.
[0007] Moreover, such cryogenic-capable pressure vessels are capable of being refueled with hydrogen in a broad range of thermodynamic states (e.g. compressed hydrogen at ambient temperature, cryogenic LH 2 , etc.) to enable more flexible usage by allowing drivers to tailor refueling choices to best meet their driving patterns and priorities (driving range, perceived safety, refueling cost, location, speed, etc). In other words, the choice of fueling options serves to optimize hydrogen storage to suit various purposes, such as maximizing driving range versus minimizing fueling cost. For example, cryogenic-compatible pressure vessels may be filled as needed with either cryogenic LH 2 which provides a greater driving range but costs more to fill, or compressed hydrogen gas, at cryogenic or ambient temperatures which provides a shorter range but significantly reduces fuel costs, increases access to a greater number of refueling locations, and extends dormancy and thermal endurance for shorter distance and/or infrequent driving trips.
[0008] Differences between conventional low-pressure cryogenic storage tanks and high-pressure cryogenically-insulated pressure vessels are discussed in the publications by Applicants entitled, “ Thermodynamics of Insulated Pressure Vessels for Vehicular Hydrogen Storage , ” UCRL-JC-128388, June 1997, and “ Analytical and Experimental Evaluation of Insulated Pressure Vessels for Cryogenic Hydrogen Storage ,” International Journal of Hydrogen Energy 25 (2000), both of which are incorporated by reference herein.
SUMMARY OF THE INVENTION
[0009] One aspect of the present invention includes a cryogenic-capable high pressure container for flexibly storing hydrogen, or other substance, in gas and/or liquid phase, comprising: a high pressure vessel (HPV) enclosing a high pressure-capable storage volume and including an access port for providing controlled access to the high-pressure-capable storage volume; and an ultra-thin thermal insulator having a thickness less than about 5 mm surrounding the HPV.
[0010] Another aspect of the present invention includes a cryogenic-capable high pressure container for flexibly storing hydrogen, or other substance, in gas and/or liquid phase, comprising: at least two substantially box-shaped high pressure vessels (HPVs) secured in stacked arrangement with each other to form a substantially box-shaped stack, each HPV enclosing a high pressure-capable storage volume and including an access port for providing controlled access to the high-pressure-capable storage volume; a substantially box-shaped lower pressure vessel (LPV) with the stack nested inside the LPV so that a lower pressure-capable storage volume is formed between the stack and the LPV, said LPV including an access port for providing controlled access to the lower-pressure-capable storage volume; and an ultra-thin thermal insulator having a thickness less than about 5 mm conformably surrounding the LPV.
[0011] Another aspect of the present invention includes a cryogenic-capable high pressure container for flexibly storing hydrogen, or other substance, in gas and/or liquid phase, comprising: at least one high pressure vessel (HPV) enclosing a high pressure-capable storage volume and including an access port for providing controlled access to the high-pressure-capable storage volume; a substantially box-shaped lower pressure vessel (LPV) with the HPV nested inside the LPV so that a lower pressure-capable storage volume is formed between the HPV and the LPV, said LPV including an access port for providing controlled access to the lower-pressure-capable storage volume; and an ultra-thin thermal insulator having a thickness less than about 5 mm conformably surrounding the LPV.
[0012] And another aspect of the present invention includes a method of flexibly storing hydrogen, comprising: providing a cryogenic-capable high pressure container having a high pressure vessel (HPV) enclosing a high pressure-capable storage volume and including an access port for providing controlled access to the high-pressure-capable storage volume, and an ultra-thin thermal insulator having a thickness less than about 5 mm surrounding the HPV; and filling the cryogenic-capable high pressure container with liquefied hydrogen having a 25/75 percentage ratio of para-hydrogen to ortho-hydrogen.
[0013] Generally, the present invention is directed to a cryogenic-capable high pressure container which in the broadest sense combines the use of cryogenic-capable high pressure vessels (HPVs) and ultra-thin thermal barrier(s). The HPVs are of a type capable of high internal pressures, such as for example greater than about 5000 psi. And in contrast to the prior thick insulations (e.g. greater than 3 cm) typically used for cryogenic storage applications, the ultra-thin thermal insulators/barriers of the present invention generally have a thickness less than about 5 mm, e.g. ˜1-3 mm because of the reduced thermal requirements of the container from the flexible usage. The reduced thickness can thus maximize a given available storage space for the storage of fuel. The “ultra-thin thermal barrier” may be one of two types: either a vacuum space, or an insulating material. In the case of a vacuum space, two vessels (e.g. stainless steel) are typically required one nested inside the other and spaced by a low conductivity support/spacer. In the case of insulation material, multiple layers of plastic may be used, for that is easily adapted to any geometry. In addition to the ultra-thin thermal insulation, the cryogenic capable high pressure container of the present invention may also be substantially “box-shaped” to conform to similarly “box-shaped” or otherwise cuboidal spaces available onboard a vehicle to further maximize fuel capacity beyond that of a cryogenic high pressure vessel of conventional shape (e.g. cylindrical, ellipsoidal, or spherical). Further still, lower pressure vessels (LPVs) (capable of internal pressures less than about 5000 psi) may also be used in conjunction with HPVs to provide additional fuel storage volumes.
[0014] Exemplary embodiments of the present invention include: “conformable” cryogenic-capable high pressure containers, 2) cryogenic capable pressure containers using cylindrical HPVS to operate at even higher pressures (e.g. in the 10-20 k psi or higher range), and 3) cryogenic capable HPVs and lower pressure conformable LPVs (both inside an ultra-thin thermal barrier/insulator) partitioning hydrogen storage capacity into higher and lower pressure spaces. All of these exemplary embodiments provide flexibility of refueling with hydrogen in different thermodynamic states (for example pressure, temperature, phase, fraction of parahydrogen, etc.) and in varying quantities, which allows the driver to best meet instantaneous requirements (i.e. refueling cost, location, and time as well as vehicle range, trip length, vessel dormancy, and thermal endurance) as discussed in the Background.
[0015] The cryogenic-capable high pressure container of the present invention may be constructed in a manner similar to previous cryogenic-compatible pressure containers such as that discussed in U.S. Pat No. 6,708,502. In this regard, in each of the exemplary embodiments, the high pressure vessel (HPV) component of the cryogenic-capable high pressure container is preferably a composite fiber-wrapped vessel similar to those used to store compressed gases. The HPVs enclose a high-pressure-capable storage volume that can be flexibly refueled, such as for example, with high pressure LH 2 . Furthermore, performance of the container may be improved and enhanced by selecting appropriate surface treatments leading to a reduction in outgassing. For example, sorbent material may be used (e.g. carbon aerogel, activated carbon, or metal-organic framework) that is located inside the vessel. The sorbent material may improve the thermal endurance of the vessel due to its thermal capacity, and it may provide enhanced hydrogen storage capability at low pressure due to its high porosity. Performance may also be improved by using fiber formulations that may approach the thermal expansion coefficient of aluminum for reduced thermal stresses. Another embodiment may use plastic liners that include liner configurations that may avoid or eliminate hydrogen permeation (See U.S. Pat. No. 6,708,502). Access ports are also provided to enable controlled access to the high pressure-capable storage volume or the low pressure-capable storage volume. Such access port may include an inlet and an outlet for filling and extracting, respectively, hydrogen to and from the respective storage volumes.
[0016] And while hydrogen is a common example of an alternative fuel used for alternative fuel vehicle (AFV) applications, it is appreciated that other fuels may also be utilized which are suitable for compressed gas storage and/or cryogenic liquid storage, such as for example compressed natural gas (CNG). In the present discussion, hydrogen is used as an exemplary fuel for generally illustrating operation of the present invention. Additionally, while the advantages of a cryogenic-capable pressure vessel are readily apparent for vehicular storage applications, it is not limited only to such. The present invention may be generally used for any application requiring flexibility in the types of fluids stored.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings, which are incorporated into and form a part of the disclosure, are as follows:
[0018] FIG. 1 shows one exemplary embodiment of a “conformable” container having multiple high pressure vessels that are each substantially box-shaped and shown with the ultra-thin thermal insulation removed.
[0019] FIG. 2 is a cross-sectional view of the exemplary embodiment of FIG. 1 , but now shown with the ultra-thin thermal insulation in place.
[0020] FIG. 3 is a partially broken isometric view of another exemplary example of a conformable high pressure vessel of the present invention using a macrolattice structure.
[0021] FIG. 4 shows another exemplary embodiment of the present invention that is a cryogenic capable ultra high pressure vessel with ultra-thin insulation and vacuum space. In particular, the ultra high pressure vessel is shown having a cylindrical shape and configuration.
[0022] FIG. 5 shows another exemplary embodiment of the present invention having a cryogenic capable high pressure vessel nested inside a conformable lower pressure vessel with a common external thermal barrier of ultra-thin vacuum insulation.
[0023] FIG. 6 shows another exemplary embodiment of the present invention similar to FIG. 5 but with two HPVs inside the LPV, and struts of a macrolattice for structurally enhancing the LPV.
DETAILED DESCRIPTION
[0024] Turning now to the drawings, FIGS. 1 and 2 show a first exemplary embodiment of a “conformable” cryogenic-capable high pressure container generally indicated at reference character 10 , that is configured for high pressure service. It is appreciated that the term “conformable” used herein and in the claims generally means a shape that substantially takes on the shape of another, and in particular to a vessel having a shape that substantially takes on the shape of a space in which it is to be mounted, positioned, or stored onboard a vehicle.
[0025] Because the vessel mounting space in a vehicle (e.g. trunk) is typically a boxy, cuboid space formed by substantially planar surfaces and edges, the conformable embodiment of the present invention is intended to better fill such available boxy spaces (not normally available to a conventional (e.g. cylindrical) pressure vessel), and thereby achieve higher storage capacity. As such, the HPVs individually and as a combined stack shown in FIGS. 1 and 2 are characterized as being “conformable” because they are substantially box-shaped, and not cylindrical or spherical. As such, “substantially box-shaped” is defined and used herein as having a shape that is substantially like a box. In other words, it generally has a shape similar to a cuboid or right rectangular prism, although not limited strictly to such. It is appreciated that while the conformability of the present invention mainly suggests a regular boxy shape to fill a regular boxy space, irregular boxy shapes may also used to fill irregular boxy spaces as well.
[0026] The container 10 is particularly shown in FIGS. 1 and 2 having nine high pressure vessels (HPVs), 11 - 13 which are secured together in a stack arrangement, and surrounded by an ultra-thin thermal insulation ( 16 - 18 in FIG. 2 ). It is notable that at least two HPVs are required for stacking. In particular, the nine HPVs include two end HPVs 11 , 12 , and seven intermediate HPVs 13 therebetween, all of which are substantially box-, pillow-, rectancular-prism-, or otherwise cuboid-shaped (hereinafter “substantially box-shaped”) so as to have six sides, including two opposing broad-faced surfaces joined by four connecting side surfaces. Adjacent HPVs are stacked together along at least one of their face surfaces.
[0027] As can be seen in FIGS. 1 and 2 , the intermediate HPVs have both opposing face surfaces which are flat due to the stacking pressure exerted by longitudinally securing the HPVs together. In contrast, the end HPVs 11 and 12 have one flat face surface and another opposite face surface with a convex, bulbous shape. All the HPVs are bound or otherwise secured together, such as with straps 14 and 15 , so that the convex face surfaces of the end HPVs are at opposite ends of the stack. Alternatively, the stack may be wrapped with carbon fiber to secure the HPVs together so as to press them together to reduce stresses in the flat faces. These HPVs are preferably made of composite material (e.g. carbon fiber and epoxy resin), with a rigid wall. It is notable that the planar intersections between the six surface segments occur at corners and edges which are preferably rounded and not angular, so as to reduce stress at the joint due to internal pressures. In this geometry, pressure exerts equal and opposite forces on the flat surfaces (as long as segments are kept at equal pressure). This has the important consequence of eliminating/canceling pressure forces (and bending stresses) on the flat surfaces. In addition to the intermediate HPVS, this embodiment requires the manufacture of end segments that have a flat end and an elliptical end to guarantee pressure elimination in all the flat surfaces. These HPVs may be fiber wound on a plastic liner in the standard procedure used for making composite pressure vessels, except that the fiber paths are different (more complex). These HPVs may also include a metallic liner (not shown).
[0028] The vacuum insulation in FIG. 2 is shown comprising an inner shell 18 and an outer shell 17 to form a vacuum space 16 therebetween. Both the inner shell and the outer shell surround the stack of HPVs, and have substantially box-shaped configurations themselves. In one embodiment the inner shell 18 may be a lower pressure vessel (LPV) with its own access port (not shown) for enabling controlled access to the interstitial space, i.e. a lower pressure-capable storage volume between the stack and the LPV.
[0029] FIG. 3 shows another exemplary “conformable” high pressure vessel HPV having a substantially box-shaped configuration, and generally indicated at 30 . In particular, the HPV 30 has an internal macrolattice structure which enables the HPV to maintain its shape under high internal pressures by reducing the bending stresses on the outer skin/walls of the vessel. As shown in FIG. 3 , only three sides 31 - 33 are shown in isometric view, with an intersecting corner thereof partially broken to reveal the macrolattice structure inside the vessel. The macrolattice structure is shown comprising struts 34 made of a rigid material, such as steel or composite, secured to the walls of the vessel at connection points 35 . The struts 34 works under tension for optimum structural efficiency. Preferably, the geometrical pattern of the struts are obtained from crystallography tables, by determining which of all the available lattices yields optimum performance. The selected lattice has high volumetric efficiency (over 80% without including the outer skin) and manufacturability (only two struts cross at any given point).
[0030] FIG. 4 shows another exemplary embodiment of the cryogenic capable high pressure container of the present invention, generally indicated at 40 , and having a substantially cylindrical shape for its HPV. In particular, this embodiment 40 is designed to maximize (re)fueling capacity both when refueled with ambient temperature high pressure hydrogen and when refueled with high pressure hydrogen at lower temperatures. Its maximum operating pressure is several times higher than the substantially box-shaped HPVs of FIGS. 1 and 2 , to deliver the same capacity in the same mounting space. Its higher pressure capability requires more structure per unit of hydrogen capacity. This same higher pressure capability enables lower thermal performance requirements, especially given driver choice(s) of refueling with hydrogen of different thermodynamic states. Thermal endurance is further enhanced as fuel is extracted by self-cooling of the remaining hydrogen in the vessel and this effect is particularly strong at higher pressures, temperatures, and hydrogen densities. In FIG. 4 , an insulation shell is spaced from the high pressure vessel to form an evacuated space 44 therebetween, i.e. the vacuum insulation.
[0031] The high pressure vessel 42 in FIG. 4 is preferably of a similar type as that described in U.S. Pat. No. 6,708,502, and in particular having a construction similar to the inner pressure container 103 thereof, e.g. a lightweight composite material having a fiber reinforced resin matrix construction that surrounds a high pressure-capable storage volume 43 . And an ultra-thin thermal insulator is shown surrounding the HPV 42 . In particular, the insulator is shown as an outer shell conformably surrounding the HPV 42 with a thin vacuum space 44 separating the outer shell from the HPV. As shown, the HPV directly sees the vacuum space, and an access port 45 is provided to control access to the high pressure-capable storage volume. An optional inner liner 42 is also shown.
[0032] FIG. 5 shows another exemplary embodiment of the present invention, indicated at 50 , which combines cryogenic capable HPV(s) with a conformable lower pressure vessel (LPV) which stores hydrogen at a lower pressure than the HPV. In particular, a single cylinder-shaped HPV 41 is shown enclosing a high pressure-capable storage volume and nested inside a lower pressure vessel (LPV) 46 such that a lower pressure-capable storage volume 47 is formed therebetween in the interstitial space. The LPV is shown having a substantially box-shaped configuration. The HPV is shown having an access port 45 for enabling controlled access to the high pressure-capable storage volume. The LPV also has an access port (not shown) for enabling controlled access to the lower pressure-capable storage volume. The two higher and lower pressure-capable storage volumes are in thermal contact. Both volumes are inside a common external ultra-thin thermal barrier 48 (vacuum space created by an outer shell 49 ), reducing heat transfer to either volume from the environment. This embodiment partitions the stored hydrogen into separate quantities, in potentially different thermodynamic states, and with different thermal endurance. This container achieves a very high combined storage capacity by utilizing the additional volume formed by the LPV. The LPV requires less structure (due to its lower pressure) thereby enabling the use of lower cost and/or strength containers. The hydrogen capacity remaining in the HPV still enables extended thermal endurance and significant self-cooling, while retaining moderate hydrogen storage capacity when refueled with ambient temperature hydrogen. A greater range of storage system aspect ratios can be achieved by using multiple cryogenic capable HPVs with a conformable LPV volume at lower pressure. As shown in FIG. 5 , the LPV and the ultra-thin thermal barrier is also substantially box-shaped so as to substantially conform to and maximize for storage a substantially box-shaped mounting space for the container.
[0033] In FIG. 6 three pressure vessels are shown which comprise the container 60 generally. Two HPVs are shown at 42 and 51 , each cylindrical in shape and enclosing respective high pressure-capable storage volumes 43 and 52 . Both HPVS are located inside the LPV 46 so that a lower pressure-capable storage volume 47 is formed therebetween. The idea is to store hydrogen not only inside the HPVs but also in the interstices between the HPVs and the LPV, i.e. the low pressure-capable storage volume, to better occupy a square space. Considering that the HPVs are rated for very high pressure and the LPV is rated for lower pressure, each vessel would have its own separate access ports to fill and extract from the respective storage volumes. The embodiment is composed of multiple cryogenic capable high pressure vessels and a lower pressure conformable container with a common external thermal barrier of ultra-thin vacuum insulation. This arrangement achieves greater aspect ratio flexibility relative to a storage system with only a single high pressure vessel. The HPVs can store cryogenic hydrogen at high pressure and the outer LPV can store (additional) liquid hydrogen at lower pressure (e.g. 1-5 atm). Also shown are struts 53 secured at ends 54 to the walls of the LPV in a macrolattice arrangement to enhance the structure of the LPV for internal high pressures. All components of the container 60 , including the struts 53 and connections 54 , 54 , are shown contained inside the ultra-thin thermal insulator that is formed by the outer shell 49 .
[0034] Furthermore, these containers can be designed to take advantage of the self-cooling available from driving that can be stored in the ortho-para nuclear spin states of hydrogen. This thermal energy storage mechanism could occur spontaneously or be intentionally accelerated. All classes of these hydrogen storage systems benefit from the possibility of refueling with lower cost (lower than equilibrium fraction of parahydrogen) cryogenic hydrogen. For example, if a vehicle is initially fueled with a quantity of liquid hydrogen in which 25% of the molecules have the nuclear spin state known as “para” and 75% of which have the nuclear spin state known as “ortho” (this mixture of hydrogen molecules is often referred to as ‘normal’ hydrogen), the orthohydrogen molecules tend to change nuclear spin state and convert to parahydrogen molecules that are more stable at liquid hydrogen temperatures. This process releases heat, increasing the pressure of the stored hydrogen. This is beneficial to vehicle operation, providing the pressure potentially needed for vehicle operation, reducing or eliminating the need for a heat exchanger. Subsequently, as the hydrogen approaches temperatures between 40 and 100 K, an increasing fraction of parahydrogen molecules will tend to convert to orthohydrogen molecules, thereby absorbing heat and significantly enhancing thermal endurance. Another possibility is deliberate manipulation of the nuclear spin states of hydrogen molecules during refueling to store even greater amounts of hydrogen in the container. For example, if the container is filled with liquid parahydrogen and then topped off with high pressure cryogenic parahydrogen, the contents warm up. Conversion to the equilibrium concentration of parahydrogen at this warmer temperature will cool and further densify the fuel. Filling the high pressure vessel and/or the low pressure space are fueled with a quantity of liquid hydrogen in which 25% of the molecules have the nuclear spin state known as “para” and 75% of which have the nuclear spin state known as “ortho” (this mixture of hydrogen molecules is often referred to as ‘normal’ hydrogen) has the following advantages. Hydrogen with this combination of spin states can be liquefied with considerably less energy (˜30% less) than the equilibrium composition of liquid hydrogen (100% para). Ortho-hydrogen at liquid hydrogen temperature will convert over a few days to para-hydrogen, releasing heat and enhancing evaporation. This makes it impossible to use normal liquid hydrogen in most applications. The high pressure capability of our cryogenic pressure vessels described here enable direct utilization of normal liquid hydrogen in the vehicle without ortho-para conversion, thereby reducing by 30% the liquefaction energy.)
[0035] While particular operational sequences, materials, temperatures, parameters, and particular embodiments have been described and or illustrated, such are not intended to be limiting. Modifications and changes may become apparent to those skilled in the art, and it is intended that the invention be limited only by the scope of the appended claims.
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A cryogenic-capable high pressure container which combines the use of cryogenic-capable high pressure vessels and ultra-thin thermal barrier(s) having a thickness less than about 5 mm because of the reduced thermal requirements of the container from flexible usage, for maximizing storage space. Additional increase in storage capacity may be obtained by using conformable pressure vessels having box-shaped configurations for further maximizing storage space and capacity. Further efficiencies may be achieved by nesting high pressure vessels inside box-shaped lower pressure vessels to utilize for storage the interstitial spaces form between them.
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FIELD OF THE INVENTION
This invention relates to artificial kidney systems, and more particularly, to an apparatus and method for controlling and reversing the flow of dialysis solution within a dialyzer.
BACKGROUND OF THE INVENTION
Artificial kidney systems usually include a dialyzer and a dialysis machine which controls the operation of the dialyzer. The dialyzer is used to treat a patient's blood so as to remove water and waste products therefrom. Such dialyzers include a semipermeable membrane which separates the blood and the dialysis solution flowing through the dialyzer. Waste product removal occurs by mass transfer through the membrane, and water removal occurs by ultrafiltration through the membrane.
Some dialysis machines operate to draw the dialysis solution through the dialyzer under a negative pressure (i.e., below atmospheric pressure). These machines normally include: (a) a negative-pressure-type pump positioned downstream of the dialyzer for drawing the dialysis solution from a source through the dialyzer; and (b) adjustable restrictions positioned upstream and downstream of the dialyzer for controlling the flow rate and the negative pressure on the dialysis solution within the dialyzer.
U.S. Pat. No. 3,878,095 Frasier et al discloses a negative-pressure-type dialysis machine of that type. A commercial machine embodying such a system is manufactured and sold by Baxter Travenol Laboratories and is identified as Proportioning Dialyzing Fluid Delivery System (5M 1352-5M 1355).
Negative-pressure dialyzers of the type sold by Baxter Travenol Laboratories under the trademark CF® dialyzer are suitable for use with such dialysis machines. This dialyzer is commonly referred to as a hollow-fiber dialyzer and includes thousands of generally axially arranged hollow fibers within which blood flows. The dialyzer has axially-spaced blood inlet and outlet ports and axially-spaced dialysis solution inlet and outlet ports. Dialysis solution flows about these fibers but in the opposite direction so as to maximize mass transfer of impurities. This type of flow is sometimes referred to as a counter-current.
Presently during dialysis, the hollow fiber dialyzer is positioned in a generally vertical attitude with blood entering the dialyzer from the top, flowing downwardly, and exiting from the bottom. Dialysis solution enters at the bottom, flows upwardly, and exits at the top. These directions of flow have been selected because of gas separation problems on both the dialysis solution and blood sides of the dialyzer.
On the dialysis solution side, this is manifested by bubbles appearing in the dialyzer, adhering to the fibers and accumulating at the top of the dialyzer due to buoyancy. The adhering and accumulating is undesirable as it reduces the efficiency of the dialyzer. The direction of dialysis solution flow was selected as upward so as to sweep as much of the separated gas out of the dialyzer as possible. Thus in order to maintain counter-current flow, the flow of blood had to be downward. On the blood side, an arterial blood trap is provided for capturing gas before it can reach the patient.
Before dialyzing a patient, a series of set-up steps are performed. These steps generally include clearing the dialyzer of gas and conditioning the dialyzer to operating temperatures, etc.
During set-up, it has been customary to flow dialysis solution into the dialyzer in the normal upward direction so as to (a) force the air on the dialysis solution side of the dialyzer out of the dialyzer and replace it with dialysis solution and render that side substantially airfree and (b) adjust the temperature of the dialyzer. The upward flow is helpful in removing air since it cooperates with the air's natural tendency to rise.
The next step is to prime the blood side, and in order to take advantage of the air's tendency to rise, the dialyzer is rotated so that the blood inlet is below the blood outlet. A saline priming solution is then flowed through the blood side of the dialyzer so as to clear the air from that side. Thereafter, the patient's blood is flowed into the dialyzer, and after the blood flow is established, the dialyzer is rotated back to its original position and dialysis can begin.
In the event an emergency causes dialysis to cease, the priming operation including reversing of positions, etc., may be repeated.
These rotation operations are inconvenient, time-consuming and cumbersome in view of all of the inlet lines, outlet lines, clamps, bubble traps, brackets, etc., that must be handled. Furthermore, in order to accommodate the rotation, the blood lines are long, the blood priming volume is large, and the amount of blood outside the patient is large.
In West German Offenlegungsschrift No. 2,824,818 filed on June 7, 1978 and laid open on Dec. 21, 1978, there is disclosed another form of a hollow-fiber dialyzer having a single blood connection and a single dialysis solution connection with connectors which can be reversed to give upward blood priming or back flushing on the dialysis solution side. In the normal operation, that dialyzer is maintained in one position and blood flows downwardly and dialysis solution flows upwardly.
However, the use of that dialyzer does not solve the problem of positioning and repositioning of the typical hollow-fiber dialyzer which has a pair of spaced blood ports and a pair of spaced dialysis solution ports.
It is therefore an object of this invention to provide a dialysis machine and dialyzer system wherein the rotation or positioning and repositioning of the dialyzer during set-up in order to prime and condition the dialyzer is not necessary.
In addition to the CF® dialyzer, there is another negative-pressure type of dialyzer known as a HD™ capillary film dialyzer. This dialyzer is sold by Baxter Travenol Laboratories under its code M1780 and M1781.
In the HD™ dialyzer, both the blood inlet and dialysis solution inlet are located at the bottom of the dialyzer and respective outlets are at the top of the dialyzer so that both the blood and dialysis solution flow upwardly. It will be noted that in the HD™ dialyzer the blood flows from bottom-to-top, while in the CF® dialyzer, blood flows from top-to-bottom. Presently this difference in flow direction requires that different flow line connections-be made by the operator.
It is therefore another object of this invention to provide a dialysis machine capable of operation with either the hollow-fiber dialyzer, the capillary-film dialyzer, or other negative-pressure-type dialyzers so as to avoid different flow line arrangements.
These and other objects of this invention will become apparent from the following description and appended claims.
SUMMARY OF THE INVENTION
There is provided by this invention a dialysis machine having a dialysis-solution-flow reversing mechanism for reversing the direction of flow of dialysis solution to and from a dialyzer and thus through a dialyzer. By using this flow reversing mechanism, the need to position and reposition the hollow-fiber-type dialyzer having spaced blood and dialysis solution ports during set-up is avoided. Furthermore, the dialysis machine is more convenient to use with different types of dialyzers where the positions of the dialysis solution inlet and outlet with respect to the blood inlet and outlet is different.
Furthermore, since repositioning of the hollow-fiber dialyzer is eliminated, the blood lines can be shortened as they do not have to be long enough to accommodate the rotation. This reduces the amount of blood needed for priming and the amount of blood outside the patient (i.e., in the extracorporeal circuit) at any given time. It has also been found that the arterial blood trap can be eliminated, but if it is desirable to monitor pressure, a very small chamber may be used.
It has also been determined that for the most effective operation, this machine should also include a degassing system which assures delivery of degassed dialysis solution which, when flowing through the dialyzer under normal operating negative pressures, will not outgas or form bubbles during dialysis.
A very effective degassing system is disclosed in U.S. Patent Application Ser. No. 750,028 filed Dec. 13, 1976. That system includes a tank having valving for defining a volume within the tank from which gas is withdrawn at negative pressures as low as about -700 mm Hg.
With the foregoing system the direction in which the blood and dialysis solution flow in the hollow-fiber dialyzer during dialysis has been changed so that dialysis solution now normally flows from top-to-bottom and blood normally flows from bottom-to-top. This upward blood flow is very desirable since it enhances gas removal on the blood side as the system now utilizes the natural buoyancy of the gas for flushing the gas from the blood side of the dialyzer.
The dialysis machine of this invention includes a flow system whereby water is drawn from a supply through the degassing tank to a site where the water is mixed with dialysis solution concentrate. From there the dialysis solution flows through a flow control valve into the flow reversing mechanism, to the dialyzer, back through the flow reversing mechanism through a blood leak detector, and then through a pressure control valve to a negative pressure pump. From the pump spent dialysis solution is discharged to drain.
The flow reversing mechanism includes a pair of three-way valves which are connected such that when the valves are in a first arrangement, dialysis solution flows through the dialyzer in a first direction, and when the arrangement of the valves is changed, the solution flows through the dialyzer in the reverse direction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the flow system for a negative pressure-flow-through-type dialysis machine having a flow reversing mechanism with the machine connected to a hollow-fiber dialyzer and the dialysis solution shown flowing in the dialyzing direction;
FIG. 2 shows only a portion of the dialysis flow system and shows the flow reversing mechanism arranged so as to reverse the direction of flow of dialysis solution through the dialyzer; and
FIG. 3 shows the outside configuration and the inlets and outlets for the capillary-film-type dialyzer.
DESCRIPTION OF THE PREFERRED EMBODIMENT
General
Referring now to FIG. 1, the dialysis flow system 10 generally is shown connected to a CF® or hollow-fiber dialyzer 12 generally. The dialyzer is elongated and has a pair of spaced blood ports 12a and 12b and a pair of spaced dialysis solution ports 12c and 12d.
The dialyzer is vertically oriented, such that during dialysis, blood enters through the inlet 12a and flows upwardly to the blood outlet 12b, while dialysis solution enters through the port 12c and flows downwardly through the port 12d.
It is noted that during dialysis the direction of blood flow and dialysis solution flow are opposite each other to provide a counter-current flow arrangement.
The Flow System
The flow system includes a water supply 14 from which the water flows to a degassing tank 16. Air is withdrawn from the top of the tank 16, through line 18 and degassed liquid is drawn from the bottom of the tank via line 20 by the pump 22. Details of this degassing system are shown in U.S. Patent Application, Ser. No. 750,028 filed Dec. 13, 1976, the disclosure of which is incorporated herein by reference. Briefly, this system is capable of applying negative pressures as low as -700 mm Hg to the liquid in the tank, the result of which is a very effectively degassed liquid.
The degassed liquid flows from pump 22 via line 24 to a mixing site 26 where the degassed liquid mixes with dialysis solution concentrate entering the site 26 from the concentrate supply 28 via line 30. The dialysis solution then flows from the site 26 via line 32 to a flow restriction 34. This restriction cooperates in controlling flow to the dialyzer 12. From the restriction 34, liquid flows via line 35 to a three-way flow control valve 36 which is sometimes referred to as the "to" valve ("to" referring to the fact that the dialysis solution flows "to" the dialyzer through the valve 36). Valve 36 has three ports, identified as "C", "1" and "0" and line 35 connects to the "C" port. When deactivated, the "C" and the "0" ports are connected, and when activated, the "C" and the "1" ports are connected.
Dialysis solution exits the valve 36 from port "1" and flows through the flow reversing mechanism 100 (which is shown in the dashed lines), and during dialysis via line 38 to the dialysis solution port 12c. A dialysis solution pressure transducer 40 is provided for detecting the dialysis solution pressure in the line 38.
During dialysis, dialysis solution flows downwardly through the dialyzer and exits via port 12d. Spent or used dialysis solution then flows from the port 12d via line 42 back through the flow reversing mechanism 100. A second pressure transducer 44 is provided for detecting the dialysis solution pressure in line 42.
The dialysis solution exits the flow reversing mechanism 100 and flows through a blood leak detector 46 and then through a second valve 48, which is sometimes referred to as the "from" valve. This valve also has "C", "1" and "0" ports and related activated and deactivated positions. In this valve, port "0" is plugged so as to prevent flow therethrough and the valve thus acts as an on/off switch. The blood leak detector 46 is positioned downstream of the flow reversing mechanism so as to detect any blood which passes through the semipermeable membrane into the dialysis solution. Detection of such blood activates various alarm conditions and prevents further dialysis until the condition is corrected.
Spent dialysis solution enters from the valve 48 at port "1", exits at port "C" and then flows via line 50 to a second flow or pressure-regulating restriction 52. The solution then flows via line 54 to the negative-pressure or effluent pump 56 which then discharges the spent dialysis solution to drain 58.
The pump 56 is also connected to line 18 and creates the negative pressure for withdrawing gas from the upper portion of the degassing tank 16.
A bypass line 60 is provided and is connected to each of the valves 36 and 48 so as to permit dialysis solution flow to bypass the dialyzer. In the event it is necessary or desirable to cause dialysis solution to bypass the dialyzer, the ports "C" and "0" of valve 36 are connected and ports "C" and "1" of valve 48 are disconnected. This prevents dialysis solution from flowing to the dialyzer 12 and directs dialysis solution through the bypass line 60 and directly to drain.
On the blood side of the dialyzer, the arterial blood pressure is detected by the arterial blood pressure transducer 62 and the venous blood pressure is detected by the venous blood pressure transducer 64.
Negative-pressure-type dialyzers operate at pressures between "0" (atmospheric pressure) and -500 mm Hg. Hollow-fiber dialyzers of the type shown in FIG. 1 normally may operate at any pressure between about 0 and -500 mm Hg, while the capillary-film dialyzer may operate at negative pressures between about -100 mm Hg and -300 mm Hg.
Flow Reversing System--Structure
Referring now to the flow reversing mechanism 100 as shown in FIG. 1, dialysis solution enters the mechanism from the vave 36 via line 102. Line 102 divides into a first branch 102a and a second branch 102b. Branch 102a connects to the "1" port of a first three-way valve 104 and the branch 102b connects to the "1" port of a second three-way valve 106.
The "0" port of valve 104 is connected to the branch 108a of the outlet line 108 and the "0" port of valve 106 is connected to branch 108b of the outlet line 108. The "C" port of valve 104 is connected to line 38 and dialyzer port 12c, while the "C" port of valve 106 is connected to line 42 and dialyzer port 12d.
Each of the valves 104 and 106 are of identical construction and are arranged such that in the deactivated position the "C" port is connected to the "0" port and in the activated position the "C" port is connected to the "1" port. It should be noted that each of the "1" ports are connected to the inlet line branch, the "0" ports are connected to the outlet line branch, and the "C" ports are connected to the dialyzer.
Flow Reversing System--Operation
When the machine is not operating, all of the valves 36, 48, 104 and 106 are in the deactivated position and therefore the common "C" port is connected to the "0" port for each of the valves.
When the machine is is operation, the valves 36 and 48 are activated so that "1" and "C" ports for each valve are connected.
During dialysis using a hollow-fiber dialyzer, such as 12, the valve 104 is in the activated position with the "C" and "1" ports connected and the valve 106 is in the deactivated position with the "C" and "0" ports connected. With the valves in those positions, dialysis solution flows into the flow reversing mechanism 100 via inlet line 102 and then through branch 102a, through the valve 104 and the dialysis solution exits via the "C" port. The dialysis solution cannot flow through line 102b since the "1" port of valve 106 is closed, which thereby prevents flow through line 102b.
The dialysis solution then flows from valve 104 via line 38 into dialyzer 12, through port 12c, downwardly through the dialyzer and exits the dialyzer at port 12d. From port 12d, dialysis solution flows via line 42 to the "C" port of valve 106, exits valve 106 through the "0" port, and then flows downwardly through branch 108b and via outlet line 108 to the blood leak detector 46. Since the "0" port of valve 104 is closed, exiting spent dialysis solution must flow through outlet line 108 as it cannot flow through branch 108a.
The flow arrangement for dialysis set-up with the hollow-fiber dialyzer is shown in FIG. 2. There the flow reversing mechanism 100 is shown with the valves 104 and 106 in positions which permit reverse or upward flow of dialysis solution through the dialyzer. The valve 104 is shown in the deactivated position with the "C" and "0" ports connected while the valve 106 is shown in the activated position with the "1" and the "C" ports connected. Dialysis solution entering via line 102 cannot flow through branch 102a since the "1" port of valve 104 is disconnected. The solution thus flows via line 102b to valve 106 and exits that valve through the "C" port. From the "C" port the dialysis solution flows via line 42 to the dialyzer port 12d. From the dialyzer port 12d, the dialysis solution flows upwardly through the dialyzer 12 to the port 12c, through line 38 and to the "C" port of valve 104. The spent dialysis solution then flows through valve 104 from the "C" port to the "0" port and then via branch 108a to the outlet line 108 and blood leak detector 46. Spent dialysis solution cannot flow through line 108b since the "0" port of valve 106 has been disconnected.
Thus in the dialysis mode using a hollow-fiber dialyzer, such as 12, the valves are positioned as in FIG. 1, and when the machine is in the set-up mode, the valves are positioned as in FIG. 2. It should be noted that in either configuration the blood leak detector 46 is positioned so as to receive dialysis solution exiting the dialyzer and thus activate an alarm in the event blood enters the dialysis solution.
Capillary-Film Dialyzers
FIG. 3 shows a capillary-film dialyzer 200. The dialyzer has a blood inlet 202 positioned at the bottom of the dialyzer and blood outlet 204 positioned at the top of the dialyzer. The position of the blood inlet and outlet is similar to the positions intended for the hollow-fiber dialyzer 12. However in the capillary-film dialyzer 200, the dialysis solution inlet 206 is at the bottom of the dialyzer and the dialysis solution outlet 208 is at the top of the dialyzer. These positions are reversed relative to the positions in the hollow-fiber dialyzer. Therefore when the capillary-film dialyzer 200 is connected to the flow system, and during dialysis, the dialysis solution will flow from bottom-to-top. Therefore during dialysis using the capillary-film dialyzer, the valving will be positioned as shown in FIG. 2 with the valve 104 in the deactivated position and the valve 106 in the activated position.
The following table summarizes the positioning of the valves 104 and 106, in the flow-reversing mechanism, for the various modes of operation with the two different types of dialyzers. As indicated before, the connection between the "C" and the "0" ports represents the deactivated state for the valves, while the connection between the "C" and the "1" ports represents the activated position.
______________________________________Dialyzer Type Flow Condition Valve 104 Valve 106______________________________________Hollow fiber Normal Activated Deactivated (C -1) (C - 0)Hollow fiber Set-up Deactivated Activated (C - 0) (C - 1)Capillary film Normal Deactivated Activated (C -0) (C - 1)Capillary film Set-up Activated Deactivated (C - 1) (C - 0) Machine Not Deactivated Deactivated Operating (C - 0) (C - 0)______________________________________
Machine Operation For Set-Up and Dialysis
As explained above, there is a set-up mode and a dialysis mode. During the set-up mode, the dialyzer is conditioned and primed with both dialysis solution and blood. The priming is intended to remove or expel gas present within the unprimed dialyzer while conditioning adjusts the temperature of the dialyzer. During set-up for a hollow-fiber dialyzer it is positioned vertically with the normal blood flow direction being upwardly. The dialyzer is connected to the machine and the flow reversing mechanism is moved into a reverse flow mode (as shown in FIG. 2), and thus the dialysis solution sweeps upwardly through the dialysis solution side of the dialyzer removing the air or gas contained therein and sweeping that gas through the outlet 12c and then eventually to drain 58. The reverse flow through the dialyzer can be continued until no gas bubbles are observed within the dialyzer. Once the dialysis solution side is primed by the flow in a reverse direction, the flow reversing system is moved to the dialysis position as shown in FIG. 1 and dialysis solution then flows downwardly through the dialyzer. The blood side of the dialyzer is then primed using saline solution, and then blood and, thereafter the patient can be dialyzed.
In the event there is any gas build-up or separation during dialysis, the dialysis solution flow through the dialyzer may be momentarily reversed to again sweep any gas accumulation from the dialyzer.
However, it is desirable that during operation gas build-up be avoided during dialysis. In a hollow-fiber dialyzer, the negative pressure on the dialysis solution side is measured by transducers 40 and 44 and may be between 0 mm Hg and -500 mm Hg. Therefore if the degassing tank 16 is operated at pressures more negative than -500 mm Hg, no gas should separate in the dialyzer. In other words, the pressure for degassing should be more negative than the pressure for dialysis. The degassing system as shown herein is of a type disclosed in U.S. Patent Application, Ser. No. 750,028 filed Dec. 13, 1976. Thus the tank 16 is subjected to negative pressures as low as -700 mm Hg. Therefore, using that degassing system, and if the hollow-fiber dialyzer is used in accordance with the manufacturer's suggestion, the dialysis solution flowing through the dialyzer is so well degassed that at the operating negative pressures no gas should come out of solution.
The capillary-film dialyzer 200 is normally operated at negative pressures on the order of -250 mm Hg to -300 mm Hg. Here again, the degassing pressure (-700 mm Hg) is more negative than the operating pressure and there should be no gas separation during dialysis.
A principle by which to determine whether or not the dialysis solution will outgas (i.e., dissolved gas will come out of solution during dialysis) can be stated as follows: The level of degassing must be such that the amount of dissolved gas in the dialysis solution must be less than the amount of dissolved gas that will be present at equilibrium for the most negative pressure anywhere in the dialyzer for the particular operating conditions.
The term "operating conditions" refers to temperature, atmospheric pressure, altitude, etc.
There is also a "rule-of-thumb" which can be employed to determine whether or not outgassing is likely. That rule of thumb relates the amount of dissolved gas to the partial pressure of oxygen (pO 2 ) in the gas.
However, it must be recognized that any rule of thumb represents only an approximation for determining whether or not the degassing is sufficient to avoid outgassing in dialyzer.
Therefore, according to the rule of thumb, the calculated pO 2 for dialysis solution in the dialyzer must be greater than the calculated pO 2 in the degasser. The pO 2 in the dialyzer is determined by the following expression.
Dialyzer pO 2 =[atmospheric pressure-negative pressure in the dialyzer-water vapor pressure at dialysis solution temperature]×0.21*
In order to determine the pO 2 in the degassing unit, the following expression can be used:
Degassing pO 2 =[atmospheric pressure-degassing negative pressure-water vapor pressure]×0.21
As an example, assume:
1. Atmospheric pressure equals 760 mm Hg;
2. Degassing pressure of -600 mm Hg;
3. Dialyzing negative pressure of -300 mm Hg; and
4. Water vapor pressure of 47 mm Hg at 37° C.
In order to determine the pO 2 in the dialyzer, the rule of thumb is applied as follows:
Dialyzer pO 2 =[760-300-47]×0.21=86.7 mm Hg
In order to determine the pO 2 in the degassing unit, the calculation is as follows:
Degassing pO 2 =[760-600-47]×0.21=23.7 mm Hg
Since the dialyzer pO 2 is greater than the degassing pO 2 , the degassing is effective to prevent outgassing in the dialyzer.
Based upon the foregoing, it is seen that effective degassing can be defined: (1) by the pressure during degassing being more negative than the pressure during dialysis; (2) by the principle as stated; or (3) by the rule-of-thumb.
It will be appreciated that numerous changes, modifications, and additions can be made to the embodiment of the machine and dialyzer shown herein without departing from the spirit and scope of this invention.
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There is disclosed herein a dialysis machine adapted for operation with a negative-pressure-type dialyzer. The machine includes a flow system having a negative pressure pump for drawing fresh dialysis solution through a dialyzer under a controllable negative pressure and for discharging spent dialysis solution to a drain.
A flow reversing valve system is positioned in the flow system for cooperation with the dialyzer to selectively control the direction of dialysis solution flow within the dialyzer in either a first direction or a second reverse direction. The flow reversing valve system is operative in a first mode to control direction of flow to and from the dialyzer in a first direction and in a second mode to reverse the direction of flow.
The dialysis machine also includes a very effective degassing system which minimizes gas build-up on the dialysis solution side of the dialyzer so that when a hollow-fiber dialyzer is used the normal dialysis solution flow is in a downward direction and blood flow is in an upward direction.
The flow reversing system may be integral with the machine or may be a separate component for use with machines that do not include an integral or built-in flow reversing system.
Finally, a method is disclosed herein for operating such a system which avoids the previous requirements for positioning and repositioning of the dialyzer during dialysis set-up.
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ORIGIN OF THE INVENTION
The invention described herein was made by an employee of the United States Government, and may be manufactured and used by or for the Government for governmental purposes without the payment of any royalties thereon or therefore.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is in the technical field of improving the capability of equipment for usage in Earth and planetary orbit and altimetry. The principles of the present invention are also applicable to any diode pumped, solid state laser system.
2. Description of Related Art
The exploration of our Earth and space requires equipment and techniques that push modern technologies. For example, the usage of lasers is increasingly common, but many of the operational aspects of lasers stand in the way of their deployment, particularly in the harsh environment of space and their inherent relative low efficiency (typically <10% electrical-to-optical). This invention improves the efficiency of these lasers, as well as enables higher pulse energies and/or higher average powers to be produced from a given design than the current state of the art.
A chief problem is the management and dissipation of the heat generated in the usage of laser equipment. A laser head or crystal in operation generates significant amounts of heat, which if not removed would deform the crystal sufficiently to render it inoperable, or at minimum, greatly distort the produced beam quality and reduce efficiency. Conventional cooling techniques, such as a contact circulating fluid, present problems of their own, e.g., the usage of liquids in the cold and vacuum of the upper atmosphere and in space. Similarly, heat sinks and other mechanisms only go so far in the removal of the operational heat. For example, in most space-based usage of lasers to date, the lasers typically have significantly reduced lifetime than that demonstrated on Earth, and some have failed in short order. The harshness of the environment and the delicacy of these instruments can mean almost immediate failure if not manufactured precisely. The cost of launching such equipment, apart from all of the R&D to get there, is very high, and prohibitive for small planetary missions, unless this problem is solved. Furthermore, with the ever-escalating power requirement for lasers, these heat dissipation problems become ever magnified, necessitating a paradigmic shift in thinking away from current techniques, which become ungainly, insufficient and inadequate for future space exploration. Finally, the heat removal capability with non-fluid, conductive means, have not been improved upon significantly in the past decade. This design offers a method of achieving gains in performance, mentioned above, by using the produced heat and thermo-optical effects to the laser cavity's advantage. In other words, the thermo-optical effects are employed to improve beam quality and efficiency, rather than attempting drastic means of removing the heat.
The National Aeronautics and Space Administration (NASA) has been at the forefront of technology for such developments. With the diverse needs of current and upcoming NASA space research, there is a growing need for laser equipment that has better operational stability for use in space, atmospheric and terrestrial instrumentation. Further, there is a need for devices, particularly—space-based devices that are more efficient, have greater operational lifespan, have reduced complexity and have lower in cost.
There is, therefore, a need for improved systems, equipment, compositions and methods that provide improved heat-dissipation capabilities for laser devices, that these devices be operational in harsh environments, that the lasers be operable in larger power ranges, and that the combination be able to function properly in difficult and extreme situations and environments.
SUMMARY OF THE INVENTION
The present invention is directed to a system, apparatus and method employing a laser with a split-head, V-assembly gain material configuration. Additionally, the present invention is directed to techniques to better dissipate or remove unwanted energies in laser operations. The present invention is also directed to techniques for better collimated, laser beams, with single spatial mode quality (TEM00), with improved efficiency, in extreme environments, such as in outer space.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as forming the present invention, it is believed that the invention will be better understood from the following Detailed Description, taken in conjunction with the accompanying DRAWINGS, where like reference numerals designate like structural and other elements, in which:
FIG. 1 is an isometric illustration of components employed in practicing the principles of the present invention;
FIG. 2 is an end view of the components illustrated in FIG. 1 in an assembled state;
FIG. 3 is an exploded illustration of the components employed in a laser system using the present invention; and
FIG. 4 illustrates the assembled components of FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described more fully hereinafter with reference to the accompanying Drawings, in which preferred embodiments of the invention are shown. It is, of course, understood that this invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It is, therefore, to be understood that other embodiments can be utilized and structural changes can be made without departing from the scope of the present invention.
As discussed, various efforts have been employed to address the problems of heat dissipation in the use of lasers. Lasers by their very nature are delicate and complex instruments. Although the mechanics of laser technology will not be fully addressed herein, it should be understood that the various components must perform at operational levels, e.g., so many mJ per pulse. Conventional laser construction has a gain medium, which receives and temporarily stores input energy, e.g., photons or other means, and reflectors or mirrors to concentrate the light or other energies so that they may escape at one end, i.e., the laser energy.
With reference now to FIG. 1 of the DRAWINGS, there is shown an isometric view of apparatus in practicing the present invention, particularly a laser head configuration, generally designated by the reference numeral 100 . As discussed, in conventional laser systems the configurations are susceptible to overheating and warping, rendering the equipment useless. As these systems are often employed in space or high altitude, these failures greatly also affect the missions, e.g., distance measurements involving LIDAR, altimetry, and orbital or other space equipment for detecting and measuring ice, vegetation, atmospheric conditions, aerosols, winds, and crust movement and a host of other uses.
With reference to FIG. 1 , a gain medium is shown, which is used in amplifying the light. It should be understood that laser light is but one form of energy that may be created and amplified, and is herein employed as a representation form of that energy. In the prior art, the gain medium is one piece of material, and, as noted, the problem is that the temperatures and heat problems quickly destroy the equipment, without adequate measures to reduce the operational heat, which, in turn, greatly increases the complexity and cost of the equipment. In the instant invention, the gain medium is in at least two parts, designated by the reference numerals 110 A and 110 B. As shown, gains 110 A and 110 B are orthogonally aligned to each other.
Also shown in FIG. 1 are laser diode arrays, which as one of skill I the art knows produces the energy for the laser, e.g., by pumping the energy into the aforementioned gains 110 A and 110 B. These laser diode array configurations are generally designated by the reference numerals 120 A and 120 B, which pump energy, e.g., at 800 nm, into the respective gains. The energy so produced is preferably first passed through a pump lens, generally designated by the reference numeral 130 , and then to the gains or slabs 110 A and 110 B. As is understood in the art, the material constituency of the gains determines their ability to store the large energies needed for laser operation, e.g., to have a high energy saturation point, which upon release reflect and build to laser strengths, as discussed further hereinbelow and as known to those of skill in the art. As discussed further hereinbelow, gains made of Neodymium-doped Ytterbium Aluminum Garnet or like material allow such energy storage through atomic transitions. At saturation, the energy is then released. The aforementioned pump lens 130 may be cylindrically-shaped and made of fused silica.
With reference again to FIG. 1 , there is also shown a waveplate, particularly a one half waveplate, generally designated by the reference numeral 140 , positioned between the two gains 110 and between the aforementioned reflections. As is known in the art, light, such as sunlight, is polarized, e.g., the photons are horizontally and vertically aligned. Sunglasses and the like are able to filter these orientations and allow only some through. The waveplate 140 of the present invention exploits some principles of physics, such as the Brewster angle, to flip the polarization of the light 90 degrees. For example, light traveling through the gain 110 A toward gain 110 B, and vice versa, has the energy passing through the waveplate, preferably a one half waveplate, reorient the energy to match the polarization of the other gain material. As noted, in the prior art, there is no such reorientation.
The isometric axis, which is also the direction of the resultant laser beam is generally designated by the reference numeral 150 . It is preferred that the laser beam be a symmetrical round or pencil beam along axis 150 , which is termed single spatial mode, or TEM00 for Transverse Electro-Magnetic 00 fundamental mode. In the prior art, this is difficult to achieve with laser slabs as the gain medium geometry since the configurations are less capable of producing a symmetric beam due to the aforementioned thermal problems. The use of slab geometries are desired for solid state laser systems since they offer the highest possible energy extraction due to the zig-zag optical path traced through the pumped region of the material. This elongated path allows the cavity-formed TEM00 laser beam profile to overlap with the highest possible fraction of the absorbed or energized gain volume. Effectively, the present invention allows laser slabs to behave optically like cylindrical laser rods, but with much higher efficiency and laser energy production capability, but without the fluid-based, heat removing complexities of rods.
With reference now to FIG. 2 of the DRAWINGS, there is shown the dual head configuration of FIG. 1 assembled and oriented along the aforementioned axis 150 (now perpendicular to the sheet), and general designated by the reference numeral 200 . As shown, a foreground diode array, generally designated by the reference numeral 220 A, corresponds to the aforedescribed diode array 120 A in FIG. 1 , with like reference numerals in the instant application referring to like components. An electrically-isolated washer, such as a Delrin washer, generally designated by the reference numeral 125 and 225 , is employed for mounting and isolating the diode arrays 120 A and 120 B in FIGS. 1 and 220A and 220 B in FIG. 2 .
Atop the diode arrays 220 are respective pump lenses 230 . As shown in FIG. 2 , the pump lenses 230 concentrate or collimate the diode arrays' energy into the aforementioned gain material 220 A. The corresponding energy infusion into the gain material 210 B also occurs. As noted, a waveplate 240 is there between, governing the polarity transitions of photons transceived therein and transmission to the opposite gain material 210 . As discussed, the axis 150 is perpendicular the sheet of FIG. 2 and through the center of the gain material 220 A shown.
As discussed, the present invention offers a radically different design over the prior art. Splitting the gain material 110 / 210 and aligning them orthogonally, overcomes many of the problems of the conventional techniques in vogue for over 30 years, particularly the management of the thermal energy distribution of the operational laser. In the conventional techniques, with the one “slab” of gain material, that slab or crystal quickly heats up. Each crystal produced a highly astigmated thermal “positive” optical lens due to the thermal gradients across its axes. The pump beam direction has a very weak, or non-existent lens as the steady state temperature across that crystal's interior along that axis is approximately constant. However, the temperature across the orthogonal axis to the pump “sheet”, has a highly Gaussian profile, or relatively cool on the sides, and hot in the center. This creates an optical refractive gradient across the laser cavity beam, and thus a net positive lens. If this laser cavity was operated with one laser head on and the other off, or passive, the output laser beam would be highly multimode in 1 axis, or it would barely lase at all and produce an useable beam, unless a small circular optical aperture and negative cylinder lens was placed in the cavity to (a) constrain the optical mode to TEM00, and (b) crudely negate the positive cylindrical thermal lens in the single operating slab. As noted, it becomes increasingly difficult to manage or dissipate that heat buildup, especially for laser systems that cannot employ water cooling, e.g., an orbiting satellite or a probe in the depths of space exploration. A unique aspect of the instant orthogonal or V-assembly gain design is the use of the deformations to an advantage, e.g., the effects of the deformations offset one another between the two slabs of gain material 210 .
With reference now to FIGS. 3 and 4 , there are shown operational equipment employing the advantages of the present invention. Shown in FIG. 3 are the various components in an exploded view, generally designated by the reference numeral 300 . A high reflective (HR) mirror 371 is at a first end. Adjacent the end mirror 371 are a pair of Risley prisms, generally designated by the reference numeral 372 , which are employed for stabilization, as is understood to those of skill in the art. Adjacent the prisms 372 is one the aforedescribed devices of FIGS. 1 and 2 , i.e., the gain material 210 , the pump lens 230 and the diode array 220 assembled as in FIG. 2 , generally designated by the reference numeral 310 A. A waveplate 340 , preferably the aforementioned one half waveplate, is between the assemblage 310 A and a corresponding assemblage 310 B on the opposite side.
Adjacent the assemblage 310 B is a thin film polarizer (TFP), and adjacent that is another waveplate 374 , albeit preferably a one quarter waveplate. Next is an electro-optic Q-switch 375 , another pair of Risley prisms 376 and the terminal HF mirror 377 .
As with conventional laser techniques, the gain material 310 , augmented by the energy from the diodes, reaches saturation, at which point the photons travel between the mirrors 371 and 377 , passing through the various components, particularly the assemblages 310 A and 310 B with the waveplate 340 therebetween. Unlike the prior art, however, the distortions due to thermal effects are minimized, offset by the unique arrangement of the dual head V-shaped configuration and the waveplate 340 .
With reference now to FIG. 4 of the DRAWINGS, there is shown the various components illustrated and described in connection with FIG. 3 assembled into an operational device. Thus, starting at the left as in FIG. 3 , there is shown a high reflective mirror 471 at one end of the device to receive the aforementioned photons along an axis generally through the center of the figure. Thus, adjacent the mirror 471 are Risley prisms 472 . Next are assemblages 410 A and 410 B with a waveplate 440 therebetween, as discussed in connection with FIG. 3 . Adjacent the assemblage 410 B is a thin film polarizer 473 , a one quarter waveplate 474 , a Q-switch 475 and another pair of Risley prisms 476 . At the terminus is the corresponding mirror 477 . As discussed, the diodes pump the gain material 310 to saturation and the photons oscillate back and forth between the mirrors 471 and 477 until release along the axis.
As described hereinabove, the instant invention provides many significant advantages over the thermally-insecure devices of prior art. Discussed hereinbelow are more particular implementation of various aspects of the present invention. It should, of course, be understood that the principles of the instant invention are applicable to all or almost all diode pumped, solid state laser applications, particularly those where heat dissipation is a problem.
The present invention, termed the V-Assembly Dual-head Efficient Resonator (VADER) in one embodiment, offers a tremendous advancement in efficiency and lifetime over current solid state, flight laser designs, while greatly reducing system complexity and cost. Derived from earlier NASA laser efforts of the past decade, VADER employs a very similar cavity design, e.g., using a Positive Branch Unstable Resonator (PBUR), a conductively cooled, optically optimized zigzag slab or gain geometry, and a Gaussian Reflective Mirror (GRM) output coupler. When carefully implemented, this cavity structure matches or surpasses all the benefits of a more complex Master Oscillator Power Amplifier (MOPA) system, but with ⅓-½ the components. When considering the extensive manpower and hardware costs associated with any flight system of similar output, this translates to a large savings in cost and schedule for any mission. In a preferred embodiment, VADER produces Q-Switched laser pulses typical of MOPAs with low fluence, large beam size, inherent TEM00 beam quality, and symmetrical thermal lens compensation.
Applicants' VADER design was based on research proving that slab-based, oscillator only, aperture-free slab-based cavities are capable of producing high quality, laser pulses. Furthermore, these oscillators can also produce short pulse widths, pulse energies and even higher efficiencies than those commonly pursued with MOPA designs. The zigzag slab aspect of this effort is key for any flight system since liquid cooling, associated with rod based lasers, is a non-starter when conductive thermal control is required. Any added technologies or advances of the state of the art employed in the VADER effort is considered important for future LIDAR instruments NASA may pursue in the near future.
The various “new” components used in the VADER design are (a) the split head V-assembly gain module, (b) high power Quasi Continuous Wave (QCW) diode arrays rated at 200 W/bar, and (c) the use of ceramic Nd:YAG as the gain material. These individual items, concepts, and technologies are unique. The present invention is also notable for reduced part count, mass, complexity, and increased efficiency of any space-bound instrument. This is especially true of solid state laser technology for remote sensing missions, given that all of NASA's solid state flight lasers to date have all exhibited wallplug efficiencies in the low single digits. In VADER, it has 20 mJ pulse capability, firmly placing it in the ice and vegetation mapping altimeter class for Earth bound missions, as well as future planetary mappers for Mars and the Jovian planets' moons.
Using recent flight driver electronics efficiency values, VADER's wallplug efficiency is nearly 10%. The part count impact is an often underappreciated aspect of such a design, as many man hours/costs are incurred to insure each optical component will survive and operate to specifications in space. These costs for each component include the purchase of many spares, microscopic inspections and documentation, multiple precision cleanings, clean environmental storage and transport, performance characterization, bonding processes into flight hardware, as well as random selection of spares for optical damage testing. The present invention has the added virtue of being simpler in design and construction. For example, VADER has 12 optics, including 2 Risley pairs for alignment, while a typical single stage MOPA system would need at least 21 optical path components, including beam expansion, 2-pass amplification, and an extra 2 pair of Risleys for post cavity alignment; essentially a part count reduction by about half.
With earlier pulsed Nd:YAG systems employing the Positive Branch Unstable Resonator PBUR-GRM design, the single zig-zag slab produced a positive thermal lens with power perpendicular to the axis of the zig-zag plane, with a weak net-negative thermal lens in the other axis. This “cylindrical” lens increases in strength with higher repetition rates and average powers and thus, must be accounted for optically within the cavity with the addition of a negative cylinder lens within millimeters to one end of the slab. VADER's dual head geometry provides a symmetrical spherical thermal lens and is accounted for in the curvature of the nearby HR end mirror. Furthermore, subtle differences in net spectral line width of each pump diodes and absorption qualities in each slab will produce a slightly elliptical laser (TEM00) beams, due to unmatched thermal lensing in each axis. This beam can be spatially adjusted to maintain circular shape by fine-tuning the drive powers in each head. This capability is unavailable in all other solid state laser schemes, to the author's knowledge, and only possible with this dual head scheme.
The VADER laser cavity is currently in an “adjustable” breadboard state for mechanical sensitivity analysis, but employing flight quality mounts and head assemblies. This provides a proven means of transition to an all-flight hardware configuration for future environmental studies such as life testing, thermal vacuum, and vibration testing. It produces 20 mJ/pulse with each laser head employing a 4-bounce, side pumped zig-zag ceramic:Nd:YAG slab, 2.8 mm thick and a center length of 17.0 mm. In a preferred embodiment it is bonded to a MbCu heat sink to match the slab's thermal expansion and is held “over” a 4-bar diode array, rated at 200 W/bar. These arrays are preferably back cooled G-packages, operated at 100 A and 100 us at a repetition rate of 240 Hz. The theoretical models predict best performance with the aforementioned GRM and HR mirror curvatures at −2.15 mROC and −6.0 mROC, respectively. The 30 cm cavity length, the GRM's 1/c2 reflective spot of w0=1.11 mm, and it's peak reflectivity of R0=63% produces a Q-switched pulse width of ˜9 ns. The cavity is preferably held at a 45 degree angle about the optic axis to allow for even convective cooling for each head. FIG. 4 shows the high degree of adjustment; 2 axes on each head and 5 axes for each end mirror. Eventually, the optical bench is designed to allow replacement of the gimbaled mirror mounts with flight quality bonded optic mounts to prepare the design for a transition to a miniaturized hardware design and enclosure.
In like fashion, the improved configuration of the present invention can be employed in many other situations where heat must be displaced or moved from the apparatus. Although particular embodiments are disclosed, it should be understood that the principles of the present invention may be made applicable in many other situations with similar needs and not just those of space exploration. Further usages of the instant invention are thus envisioned and within the scope of the present application and the claims.
It should be understood that the principles of the present invention may be made applicable in a wide range of situations, not necessarily the extremes of space exploration or high elevations. Indeed, the present invention may be employed not only in earth's (or other extraterrestrial bodies') orbits or atmospheres, but also in countless ground-based applications where high energy lasers are employed. The control of the laser beam is of critical importance in many optical instruments, and the principles of the present invention for reducing the deleterious effects of heat generation are thus useful in a wide context.
Although the present invention illustrates the usage of Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG), a crystalline gain material, other such crystalline gain materials are applicable, provided the materials have sufficient performance capabilities. For example, additional gain materials include Gallium Scandium Gadolinium Garnet (GSGG), Ceramic YAG, and Yttrium Lithium Fluoride (YLF), particularly if Neodymium doped.
While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the invention is not to be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention as claimed.
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A system, apparatus and method employing a laser with a split-head, V-assembly gain material configuration. Additionally, the present invention is directed to techniques to better dissipate or remove unwanted energies in laser operations. The present invention is also directed to techniques for better collimated laser beams, with single spatial mode quality (TEM00), with improved efficiency, in extreme environments, such as in outer space.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a fluid filter, particularly a liquid filter, especially an oil filter for an internal combustion engine, comprising a receiving head, a cup-shaped housing releasably connectable to the receiving head, and a replaceable filter element disposed in the cup-shaped housing.
[0002] Two major types of fluid filters, particularly oil filters for internal combustion engines, are known in the art. The first major type comprises so-called spin-on filters. A spin-on filter has a cup-shaped housing, a filter element non-releasably disposed therein, and a threaded end plate. The cup-shaped housing is made of metal, so that it can withstand the pressure pulsation which occurs in the interior of the filter during operation of the internal combustion engine. The spin-on filter is screwed onto a receiving flange, or directly onto the engine block of the internal combustion engine, and during servicing is completely replaced with a new spin-on filter. This has drawbacks, however, resulting from the material mix of the filter because a mixture of plastics, paper, and metal must be disposed of, and material separation for disposal is problematic.
[0003] The second major filter type comprises so-called oil modules in which a filter element is releasably disposed in a preferably cup-shaped housing and with the aid of this housing is likewise screwed onto a receiving head located within the oil circuit. For servicing, only the metal-free filter cartridge needs to be replaced, while the cup-shaped housing is a lifetime component.
[0004] German Utility Model No. DE 200 04 31 U1 discloses a liquid filter with a bypass valve. A hollow cylindrical filter element is releasably disposed within a cup-shaped housing, and the cup-shaped housing is screwed onto a connection head. A support tube, which receives the bypass valve, is disposed concentrically within the interior of the filter element. The drawback of this arrangement lies in the changing of the filter element. First, there is a risk of contamination of the direct surroundings of the oil filter element because the oil-soaked filter medium still contains a residual amount of oil, which may drip as the filter element is replaced. In addition, the hands of the service personnel may become soiled because they come into direct contact with the oil-soaked filter element.
SUMMARY OF THE INVENTION
[0005] Accordingly, it is the object of the present invention to provide an improved fluid filter, especially one which is suitable for internal combustion engine applications.
[0006] Another object of the invention is to provide a fluid filter that can be disposed of without requiring separation of different materials.
[0007] A further object of the invention is to provide a fluid filter which is simple and clean to use.
[0008] It is also an object of the invention to provide a fluid filter which offers protection against pressure pulsations.
[0009] These and other objects are achieved in accordance with the present invention by providing a filter system for filtering a fluid comprising a receiving head, a cup-shaped housing releasably connectable to said receiving head, and a replaceable filter element disposed in said housing, in which the filter element is provided with a liquid-tight casing which is received in the interior of the cup-shaped housing.
[0010] The fluid filter system according to the invention, particularly a liquid filter, especially an oil filter for an internal combustion engine, has a cup-shaped housing, a replaceable filter element disposed therein, and a receiving head, such that the cup-shaped housing is releasably connectable to the receiving head. The filter element further has a liquid-tight casing within the cup-shaped housing. The liquid-tight casing is preferably made of a plastic material, which may be blow molded or injection molded. The exterior shape resembles the interior shape of the cup-shaped housing, i.e., here too, a cup shape is preferred. This shape may be designed to fully contact the cup-shaped housing, contact it only at a few points, or not contact it at all, but the distance between the inner wall of the cup-shaped housing and the outer wall of the liquid-tight casing should be as small as possible. This has the positive effect that when the filter element is replaced, the liquid present within the filter element cannot escape, and contamination of the environment is prevented. Soiling of the hands of the service personnel is also avoided because the outer shell of the liquid-tight casing is dry and clean. A further advantage compared to the conventional oil modules is that soiling of the inner wall of the cup-shaped housing is also avoided because the inner wall of the cup-shaped housing does not come into contact with the circulating oil.
[0011] In accordance with one advantageous embodiment of the invention, the cup-shaped housing is capable of absorbing and counteracting operational diameter fluctuations of the liquid-tight casing. These operational diameter fluctuations may, for example, comprise a diameter increase as a result of temperature fluctuations. By matching the liquid-tight casing to the cup-shaped housing it is possible to produce the liquid-tight casing with a thin wall thickness and to use an inexpensive plastic, so that the manufacture of the filter element becomes more cost-effective, and the desired functions can nevertheless be fulfilled. The cup-shaped housing, on the other hand, can be made more robust using a metal or plastic, so that it can absorb the diameter increase of the liquid-tight casing. The liquid-tight casing is supported against the robust cup-shaped housing, which as a lifetime component can have a greater wall thickness than the liquid-tight casing.
[0012] It is advantageous if the filter element comprises at least one hollow cylindrical filter bellows, which sealingly separates a liquid inlet from a liquid outlet. To this end, the liquid-tight casing includes a support for the radial outer contour of the filter bellows. The filter bellows may be constructed from a zigzag folded or wound filter medium, which may be made of filter paper or a synthetic nonwoven material. Because of the pressure pulsation during operation there is a risk that the filter bellows will collapse under certain circumstances. To counteract this, many hollow cylindrical filter elements have a support member within their interior diameter, but this does not eliminate the risk of an outward collapse. With this configuration, a radial expansion of the filter bellows as a result of pressure pulsations can be absorbed by the support within the liquid-tight casing. In combination with the absorption of the diameter fluctuations of the liquid-tight casing by the cup-shaped housing, the forces that occur can be transmitted directly to the cup-shaped housing via the liquid-tight casing. The result is a combination of ease of maintenance through clean servicing of the filter element, integration of the function of an external support member for the filter bellows, and cost-effective design of the liquid-tight casing because certain functions influencing stability can be assumed by the cup-shaped housing.
[0013] It is advantageous if the outer support is constructed as circumferentially distributed support contours in the liquid-tight casing. On the one hand, the support contours support the outer contour of the filter bellows against radially outwardly acting forces and, on the other hand, the support contours transmit the absorbed forces to the cup-shaped housing.
[0014] In accordance with another embodiment of the invention, the support contours form discharge volumes between the filter bellows and the inside of the liquid-tight casing, such that the discharge volumes communicate with the floor of the liquid-tight casing. As a result, the liquid cleaned by the filter bellows can flow through the discharge volumes to the floor of the liquid-tight casing. Apart from these advantages, i.e., greater ease of maintenance and the function of an external support member, a third advantage is achieved, i.e., the possibility of using the support member to receive and transfer a liquid.
[0015] In accordance with yet another advantageous embodiment of the invention, the liquid-tight casing has at least one active contour in the region of one of the end faces, extending radially beyond the circumferential diameter. This active contour enables, for example, a precise radial and axial association or positioning relative to the cup-shaped housing. The active contour also makes it possible to check whether a filter element is inserted and whether the inserted filter element is suitable for the filter system.
[0016] Advantageously, the active contour is designed to communicate with a recess in the cup-shaped housing. Because no liquid is present outside the filter element, the filter element can be easily inserted into the cup-shaped housing and axially and radially fixed without a special seal being required.
[0017] According to another advantageous embodiment of the inventive concept, an integral anti-drain membrane or back-flow check membrane is disposed in the region of the liquid inlet and outlet. This integral anti-drain membrane functions as a normal anti-drain membrane in the inlet region and, in addition, as an anti-drain valve in the outlet region. During operation of the internal combustion engine the inlet and outlet are open if the filter element is inserted. If the filter element is removed, however, the integral anti-drain membrane prevents the content of the filter element from flowing out of the inlet and/or outlet. This again has a substantial advantage during servicing because the filter element can be removed from the cup-shaped housing and disposed of at an angle to the horizontal without any leakage of the liquid contents which remain in the filter element.
[0018] According to yet another embodiment of the invention, two hollow cylindrical filter bellows are arranged concentrically within the interior of the liquid-tight casing. The filter bellows have a common end disk on one end face, and each bellows has a separate end disk on the other end face. The end disk is preferably made of a thermoplastic material, and the filter bellows are connected to the end disk by adhesive bonding or fusion welding. The common end disk is preferably annular in shape, so that a flow-through opening for the filtered liquid is formed concentrically in the interior of the inner filter bellows. The separate configuration of the two end disks on the opposite end face of the two filter bellows makes it possible to realize filter bellows having differing axial lengths.
[0019] It is advantageous if the common end disk has spring member on the side opposite the filter bellows to support the filter bellows against the inside of the floor of the liquid-tight casing. This makes it possible to axially support and fix the filter bellows relative to the liquid-tight casing.
[0020] According to yet another advantageous embodiment of the invention, the separate end disk of the outer filter bellows simultaneously forms a tight seal for the liquid-tight casing, so that the radially outer rim of the end disk is tightly and non-releasably connected to the liquid-tight casing. This connection may, for example, be provided by welding, bonding or some other conventional process for permanently connecting two plastic parts.
[0021] In addition, the separate end disk may advantageously have an annular collar that extends axially away from the filter element. A seal member to seal the filter element relative to the connection head is disposed within the annular collar. This seal member may, for example, be an O-ring or a sealing ring, which is disposed in a groove formed in the outer or inner circumference of the annular collar. Thus, the end disk of the outer filter bellows on the one hand secures the filter element and on the other hand seals the filter element and provides a connection to a connection head.
[0022] The liquid is filtered as follows. The unfiltered liquid flows through at least one inlet into a gap between the two filter bellows. To filter the liquid, it then passes through the two filter bellows—radially inwardly on the one hand and radially outwardly on the other. The filtered portion of the liquid stream that flowed inwardly into the interior of the inner filter bellows then flows back into the liquid circuit through the outlet. The filtered portion of the liquid that flowed radially outwardly into the outer filter bellows is conducted to the floor of the liquid-tight casing by the active contours of the liquid-tight casing, from where it flows through the opening in the separate end disk to reach the interior of the inner filter bellows. From there it is likewise transferred back into the liquid system through the outlet.
[0023] These and other features of preferred embodiments of the invention, in addition to being set forth in the claims, are also disclosed in the specification and/or the drawings, and the individual features each may be implemented in embodiments of the invention either alone or in the form of subcombinations of two or more features and can be applied to other fields of use and may constitute advantageous, separately protectable constructions for which protection is also claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will be described in further detail hereinafter with reference to illustrative preferred embodiments shown in the accompanying drawing figures, in which:
[0025] FIG. 1 is a sectional view of a liquid filter according to the invention;
[0026] FIG. 2 is a sectional view of the filter element and the cup-shaped housing;
[0027] FIG. 3 is a perspective view of the filter element and the cup-shaped housing;
[0028] FIG. 4 is a separate perspective view of the cup-shaped housing;
[0029] FIG. 5 is a sectional view of an outer shell of a filter element according to the invention;
[0030] FIG. 6 is a perspective view of the anti-drain membrane;
[0031] FIG. 7 is a top view of a section in the region of the blocking member;
[0032] FIG. 8 is a sectional view of an alternative anti-drain membrane, and
[0033] FIG. 9 is a sectional view of a portion of an alternative filter element.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0034] FIG. 1 is a sectional view of a liquid filter system 10 in which a cup-shaped housing 11 is connected to a connection head by a bayonet connection. The connection head 12 may be a separate connecting flange, or it may be formed directly from an internal combustion engine component. The filter system is suitable for liquids of any kind used in an internal combustion engine, such as oils, fuels, hydraulic fluids, or coolants. An inlet 13 and an outlet 14 are disposed in the connection head 12 of the filter system 10 . The outlet 14 is arranged concentrically in the center of the connection between the cup-shaped housing 11 and the connection head 12 . The inlet 13 is distributed concentrically around the outlet 14 , also in the interior of the connection between the cup-shaped housing 11 and the connection head 12 .
[0035] Inside the cup-shaped housing 11 is a filter element 15 . The filter element 15 comprises a canister 16 which holds the filter medium or media. The circumference of the canister 16 is radially outwardly supported against an inside wall 17 of the cup-shaped housing 11 . At the same time the canister supports an outer wall 18 of a first filter bellows 19 via grooves formed in the canister 16 . The canister 16 is liquid-tight and additionally functions as an outer support tube for the first filter bellows 19 and a support against pressure pulsations at the cup-shaped housing 11 . As a result, the canister 16 can be constructed relatively thin with regard to its material thickness because the actual support against each pressure pulsation is provided by the cup-shaped housing 11 .
[0036] Disposed concentrically within the interior of the filter element is a support tube 20 around which extends a second filter bellows 21 . The first and second filter bellows may be a zigzag folded filter medium, a wound filter medium, a combination thereof, or some other conventional filter bellows. In the region of a housing floor 22 of the canister 16 , the two filter bellows are held by an end disk 23 , which is ring-shaped with a concentrically disposed opening 24 . A spring element 25 is integrally formed on the end disk 23 . Spring element 25 supports the filter bellows against the housing floor 22 and axially locates and fixes the filter bellows by applying an axial spring force in an upward direction. Radial location and fixation is achieved by the inner contour of the canister 16 .
[0037] At the opposite end of the filter bellows, the first filter bellows 19 has an end disk seal 26 . The second filter bellows 21 , which is disposed in the interior of the first filter bellows 19 , extends slightly higher in the axial direction than the first filter bellows 19 . The end face seal of the second filter bellows 21 is provided by an end disk 27 , which is annular in shape and has a concentric passage for the outlet 14 . The end disk 27 has a coupling contour 28 extending axially toward the connection head 12 for an anti-drain membrane 29 . This coupling contour 28 is distributed across the end disk 27 and comprises a plurality of pins or mushroom-shaped contours protruding axially toward the connection head 12 . The anti-drain membrane 29 is tightly coupled to the end disk 27 by the coupling contour 28 . It seals the liquid inlet 13 when the internal combustion engine is stopped and the liquid outlet 14 during servicing. The anti-drain membrane 29 is preferably made of a soft thermoplastic material, such as a thermoplastic elastomer (TPE).
[0038] The end disk 26 comprises a concentric, axially protruding annular collar 30 with a groove in its outer circumference to accommodate a sealing ring 31 . When the cup-shaped housing 11 is connected to the connection head 12 , the annular collar 30 is inserted into a collar seat 32 of the connection head, so that the sealing ring 31 provides a seal between the annular collar 30 and the collar seat 32 . Disposed concentrically in the interior of the collar seat 32 is an outlet tube 33 , which extends into the opening of the end disk 27 and thereby opens the anti-drain element of the anti-drain membrane 29 on the outlet side. To seal the unfiltered side from the filtered side, sealing is effected radially between the anti-drain membrane 29 and the outlet tube 33 , which is disposed in the connection head 12 . To seal the filter element 15 liquid tight, the canister 16 and the end disk 26 are non-releasably and sealingly interconnected by a connecting contour 34 , e.g., by fusion welding or adhesive bonding.
[0039] To release the filter element for servicing and to connect it, the cup-shaped housing 11 has a tool-holding fixture 35 having, for example, a hexagon socket or a hexagon head. For servicing, a tool is applied at this point to separate the cup-shaped housing 11 from the connection head 12 , or to reconnect the two parts. The plurality of circumferentially spaced locking element parts 36 in the form of a radially outwardly protruding lug is shaped from the one axial end of the canister 16 . These parts engage in recesses of the cup-shaped housing and recesses within a locking contour of the cup-shaped housing 11 , which will be described with reference to the following figures. The part 36 of the locking elements of the canister 16 simultaneously serves as a connecting contour 34 relative to the end disk 26 . The connection head 12 has guides 37 into which locking contours formed from the part 36 of the locking elements of the canister 16 and from the cup-shaped housing 11 can be inserted and in which they are guided.
[0040] Disposed in the outer region of the connection head 12 is at least one blocking member 38 , which prevents a connection between the cup-shaped housing and the connection head 12 when no filter element 15 or a wrong filter element is inserted. The blocking member 38 then engages in a recess 44 of the cup-shaped housing 11 and thereby prevents the bayonet connection from closing. The function of the blocking member 38 is illustrated in FIG. 7 .
[0041] The liquid to be filtered flows through the inlet 13 of the connection head 12 into a space 39 between the two filter bellows 19 , 21 , then flows through the second or inner filter bellows 21 into a discharge chamber 40 located on the filtered side within the support tube 20 . From the discharge chamber 40 the filtered liquid flows back into the system through the anti-drain membrane 29 , which is opened by the outlet tube 33 , and through the outlet 14 located on the filtered side. Another portion of the unfiltered liquid flows radially outwardly from the space 39 through the first or outer filter bellows 19 into a space on the canister side, from whence it flows downwardly to the canister floor 22 . From the canister floor the liquid can again be returned to the system through the outlet 14 on the filtered side.
[0042] FIG. 2 illustrates the combination of the filter element 15 and the cup-shaped housing 11 in a sectional view. Components corresponding to those depicted in FIG. 1 are identified by the same reference numerals. FIG. 2 shows that when the cup-shaped housing 11 and the filter element 15 are released from the connection head 12 , the anti-drain membrane 29 returns to its original shape in the region of the outlet 14 on the filtered side because the outlet tube 33 is no longer present, so that the anti-drain membrane prevents the liquid stored in the filter element 15 from leaking out. Since the anti-drain membrane 29 is made of a thermoplastic elastomer, the contour can generate a return force within the blocking membrane, which return force has the effect of producing a tightly closed seal at the outlet.
[0043] FIG. 3 is a perspective view of the cup-shaped housing 11 and the filter element 15 disposed therein. Parts corresponding to those depicted in the previous figures are identified by the same reference numerals. This figure clearly shows the plurality of coupling contours 28 of the end disk 27 for the anti-drain membrane 29 . The open axial end of the cup-shaped housing 11 further has a plurality of regularly spaced locking contours 42 around the circumference to produce the bayonet connection within the filter system 10 .
[0044] When the filter element 15 is correctly installed, the locking element part 36 on the filter element side is disposed in a recess 43 of the locking contour 42 to complete the locking contour 42 . If the filter element 15 is not inserted, or if the filter element does not match, the recess 43 within the locking contour 42 remains free, so that the blocking member 38 prevents a bayonet-type connection between the cup-shaped housing 11 and the connection head 12 . The blocking member 38 then engages in the recess 43 and prevents the cup-shaped housing 11 from being twisted relative to the connection head 12 .
[0045] FIG. 4 shows a perspective view of the cup-shaped housing 11 . To insert the filter element 15 , the cup-shaped housing 11 has circumferentially spaced recesses 44 extending axially from the open end of the cup-shaped housing 11 and ending in the recesses 43 for the locking contour. The filter element 15 with the parts 36 of the locking elements is inserted into the recesses 44 until it reaches the end of the recess 43 of the locking contour so as to complete the locking contour 42 . Only this completes the locking contours 42 to establish the connection to the connection head 12 .
[0046] FIG. 5 is a sectional view of the canister 16 , which represents the outer shell of the filter element 15 . A plurality of grooves 45 are distributed across the lateral face of the canister 16 and form a support face 46 within the interior of the canister 16 for the first filter bellows 19 . Because the grooves, 45 in the inner circumference of the canister 16 are not continuous, the filtered liquid flowing through the first filter bellows 19 can be easily fed to the discharge space 40 on the filtered side via the canister floor 22 .
[0047] The rest of the above-described filter element is then inserted into the canister 16 and is connected to the canister 16 at the connecting contour 34 . This creates a liquid-tight system that prevents contamination of the surroundings and the environment and eliminates the handling of dirty filters by the maintenance personnel during servicing. The axial seal of the canister 16 in the region of the open end is again formed by the locking element part 36 , which engages in the recess . 43 of the locking contour 42 of the cup-shaped housing 11 .
[0048] FIG. 6 is a perspective view of the anti-drain membrane 29 . Components corresponding to those shown in the preceding figures are again identified by the same reference numerals. The anti-drain membrane 29 is substantially plate-shaped and is preferably made from a thermoplastic elastomer. Anti-drain membrane 29 has a plurality of openings 47 in the plate-shaped part to create the coupling with the end disk 27 via the coupling contour 28 . In its outer region, the anti-drain membrane 29 has a sealing face 48 angled relative to the plate-shaped region for the inlet area of the filter system 10 . Because of the flexibility of the material, the inlet area lifts from a sealing face in the end disk seal 26 as the liquid to be filtered streams in and thereby ensures the inflow of the liquid. When the internal combustion engine is stopped, i.e., when there is no liquid pressure against the anti-drain membrane, the sealing face 48 seals the inlet 13 because of its elasticity.
[0049] Concentrically disposed in the interior of the anti-drain membrane 29 is a type of sealing valve 49 to seal the outlet when the filter element is removed from the liquid circuit. The outlet seal 49 has a kind of duckbill, which in the inserted state is opened from the connection head 12 by the outlet tube 33 and which closes again because of its inherent elasticity when the outlet tube 33 is removed. Here, the anti-drain membrane and the anti-drain valve are integrated in a single component.
[0050] FIG. 7 illustrates one possibility of using the blocking member 38 . Once again, parts corresponding to those shown in the previous figures are identified by the same reference numerals. FIG. 7 shows a top view of a cutaway section in the area of the blocking member 38 . The blocking member 38 is disposed in the connection head 12 . A locking pin 50 and a spring member 51 are disposed in the connection head 12 such that the locking pin 50 is axially displaceable against the force of the spring member 51 .
[0051] When the cup-shaped housing 11 and the locking head 12 are brought together and no filter element 15 is present or provided, the force of the spring 51 causes the locking pin 50 to engage in the recess of the locking contour 43 , thereby preventing the twisting necessary to create the bayonet connection. If the filter element 15 is inserted correctly, the recesses 43 and 44 are filled by the locking element part 36 of the filter element 15 and thereby complete the locking contour 42 . As a result, the locking pin 50 is pushed into the locking head 12 against the force of the spring member 51 , so that the cup-shaped housing 11 can be twisted relative to the connection head 12 , allowing the bayonet connection to be created.
[0052] FIG. 8 shows a sectional view of an alternative anti-drain membrane 29 . Again, pars corresponding to those shown in the preceding figures are identified by the same reference numerals. In this embodiment, the connection to the filter element is realized in an alternative manner through a circumferential annular groove 52 disposed concentrically to the inlet sealing face 48 . This annular groove receives an end disk (not shown). This connection is discussed further below with reference to FIG. 9 .
[0053] FIG. 9 shows a sectional view of a portion of an alternative filter element using the anti-drain membrane 29 . Again, parts corresponding to those shown in the preceding figures are identified by the same reference numerals. In this case, the inner filter bellows 21 is sealingly connected by hot plate welding to the lower end disk 23 and the upper end disk 27 . A securing ring 53 holding the anti-drain membrane 29 is concentrically disposed within the end disk seal 26 . The securing ring 53 is preferably integrally connected to the end disk seal 26 via connecting webs 55 , such that the connecting webs 55 are circumferentially disposed around the outlet 14 . The end disk seal 26 and the end disk 23 each have sealing faces 54 for the outer filter bellows 19 and in addition fix the outer filter bellows. The canister 16 (not shown) may be configured analogously to the preceding embodiments and thus connects the two end disks 23 and 26 .
[0054] The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Since modifications of the described embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed broadly to include all variations within the scope of the appended claims and equivalents thereof.
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A filter system for a fluid, particularly a liquid filter, especially an oil filter for an internal combustion engine, having a receiving head, a cup-shaped housing releasably connectable to the receiving head, and a replaceable filter element disposed the cup-shaped housing, in which the filter element has a liquid-tight casing which is received in the interior of the cup-shaped housing.
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BACKGROUND OF THE INVENTION
The present invention relates to a friction lining carrier member having replaceable friction linings, in particular, for clutch-type disc brakes, with the friction linings moving axially in frictional engagement with a disc and being guided and held radially inwardly and outwardly in positive engagement by appropriate formations on the friction lining carrier member. The friction linings also being supported in the circumferential direction of the disc by supporting elements which are in force-transmitting connection with the friction lining carrier member.
A friction lining carrier member of this type is known from German Patent DE-OS 2,100,009. The friction lining carrier member is constructed as a circular segment having a dove-tailed groove arranged in the circumferential direction of the disc on the radially outwardly and radially inwardly edges of the circular segment so that a track-like guidance is established in the circumferential direction of the disc. Friction linings are positioned in this guidance, with an intermediate part disposed in the guidance located between the friction linings. The guidance is closed on both ends by clamping elements so that the friction linings are fixed in the circumferential direction of the disc as well.
Although this arrangement allows an easy replacement of the friction linings, the friction linings are subjected to different mechanical loads. When such an arrangement is brought into frictional engagement with a disc rotating in the main direction of rotation, the friction linings will transmit the friction forces occurring thereat onto that clamping element lying to the rear of the friction linings when looking in the main direction of rotation. Due to this, the friction element directly adjacent to the clamping element will have to transmit all friction forces of the friction linings inserted ahead of it, since the intermediate parts are not connected to the friction lining carrier member in the circumferential direction. Thus, the friction lining closest to the clamping element is required to transmit the entire amount of friction forces onto the clamping element. Due to this increased mechanical load, this friction lining is subjected to greater wear resulting in the friction volume available from the other linings not being permitted to be fully utilized. This disadvantage will be greater when more individual friction linings are arranged in a friction lining carrier member.
German Pat. DE-PS 927,905 shows a different arrangement of several friction linings on a friction lining carrier member. The friction linings are rigidly arranged on a backing plate, with the backing plate including mechanisms in the circumferential direction enabling the backing plate to be secured to fasteners on the friction lining carrier member. Each single fastening mechanism, however, has to be secured against detachment which considerably increases the expenditure needed for such an arrangement.
French Pat. No. 1,205,580 shows as an alternative arrangement where a circular disc is provided with friction linings rivoted or otherwise fastened thereto. Replacement of the linings is particularly time-consuming with an arrangement like this since several connections have to be removed and renewed.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a friction lining carrier member, in which the friction linings are held and supported in a guidance in such a manner that the friction linings are worn out substantially equally when loaded. The friction lining carrier member of the present invention also permits a simple and quick replacement of the friction linings without need for additional special tools.
A feature of the present invention is the provision of a friction lining carrier member having a plurality of replaceable friction linings comprising: the carrier member having a first formation on an inner portion thereof and a second formation on an outer portion thereof, each of the plurality of friction linings being guided in a circumferential direction between and in positive engagement radially with the first and second formations; and at least one supporting element disposed between each adjacent ones of the plurality of friction linings, the supporting elements being in a positive engagement with the carrier member and held in position in the carrier member by one of the adjacent ones of the plurality of friction linings. Such a supporting element may be easily detached and used several times. Thus, an extremely easy assembly of the friction linings in the friction lining carrier member is ensured which may be effected comparatively fast.
A favorable form of the supporting element is a round bolt member having a substantially rectangular head having a larger diameter than the bolt. Manufacturing technique requirements for such a supporting element may be easily met which results in comparatively low costs.
If the head includes a step on the side close to the friction lining and if the head is placed in a recess in the friction lining carrier member such that the step and the surface of the friction lining carrier member form one plane, the bolt member is able to be held in positive engagement by simply shifting the next friction lining against the supporting element. The friction lining will then be positioned on the step in such a manner as to be able to bear against the end face of the head close to itself. Provision of a force-receiving locking mechanism is thereby ensured for both directions of movement or directions of load on the friction linings.
The bolt member is preferably situated in a through-bore in the friction lining carrier member, thereby enabling the removal of the bolt member that may be stuck due to rusting or corroding by a punch.
The friction lining carrier member is most favorably constructed in the form of a circular ring, the inner and the outer rim of which having circumferential grooves facing each other. Thus, a simple guidance for the friction linings is made available. The simplest form is provided by the grooves being of dove-tailed cross section.
For ease of assembling the friction linings, the outer or the inner groove includes a gap whose width corresponds to at least the width of a friction lining. This enables assembly of the friction linings in the carrier member without difficulty. The gap is favorably closed by a clamping element completing the interrupted groove. This arrangement guarantees a safe mounting of each friction lining.
The clamping element is also easily detachable, since it is held to the friction lining carrier member by means of a clamping sleeve. An additional axial securing of clamping element is accomplished by the clamping element engaging axially in positive engagement with a radially outwardly extending groove in the friction lining carrier member.
The clamping element may be likewise fixed radially to the friction lining carrier member by means of the clamping sleeve. A particularly simple construction is provided by a cramp maintaining the clamping element in its position on the friction lining carrier member. A simple arrangement, which is detachable without need for special tools, for the cramp includes two pins in two bores of the clamping element, with the pins being received in bores of the friction lining carrier member.
BRIEF DESCRIPTION OF THE DRAWING
Above-mentioned and other features and objects of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a top view of a friction lining carrier member for an internally expanding clutch-type disc brake in accordance with the principals of the present invention;
FIG. 2 is a cross sectional view taken along line II--II of FIG. 1;
FIG. 3 is a cross sectional view of the clamping element taken along line III--III of FIG. 1;
FIG. 4 is a side view of a supporting element;
FIG. 5 is a top view of the supporting element of FIG. 4;
FIG. 6 is a cross sectional view through a clamping element with radial fastening; and
FIG. 7 illustrates a clamping element connected in its operative location.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The example cited herein shows but one possibility of a friction lining carrier member appropriate for a clutch-type disc brake or for a clutch disc. The present invention is, however, also suitable for arrangements of spot-type disc brakes with a plurality of friction linings on one friction lining carrier member.
In FIG. 1, reference numerals 1 to 12 designate the replaceable friction linings. The friction lining carrier member 13, having the form of a circular ring, includes a groove 14 at its radially outer rim and a groove 15 at its radially inner rim. Grooves 14 and 15 face each other and are constructed, for instance, to have a dove-tailed cross section. A guidance is provided due to this structure, in which friction linings 1 to 12 are positioned. For this purpose, outer groove 14 has a gap 19, the length of which corresponds to at least the width of a friction lining. Gap 19 is closed by a clamping element 16 completing the outer groove 14 in gap 19. Located between friction linings 1 to 12 are the supporting elements 17 which are inserted in bores 18 of friction lining carrier member 13.
In FIG. 2, a supporting element 17 in friction lining carrier member 13 is shown in detail. Supporting element 17 is a round bolt 20 with a head 21 having a larger diameter than the bolt and constructed substantially rectangular as shown in FIGS. 4 and 5. Head 21 has a step 24 disposed in an end face close to friction lining 4. Bolt 20 is housed in a bore 18 terminating in an enlarged bore 27 at the end portion close to the friction linings. Enlarged bore 27 is constructed so as to receive a part of head 21 and such that step 24 will be positioned in enlarged bore 27 such that the surface 25 of step 24 forms one plane with the surface 26 of friction lining carrier member 13. The adjoining friction lining 4 will be moved up to the side 23 of head 21, thereby covering step 24 completely. Supporting element 17 is thus secured axially in its mounting position by the friction lining and is fixed in an operative connected relation in friction lining carrier member 13.
The assembly of friction linings 1 to 12 in member 13 is carried out as follows, for example. A first friction lining 6 is positioned in gap 19 and moved up to the illustrated position in the guidance provided by grooves 14 and 15. On the right and on the left of friction lining 6, supporting elements 17 are inserted which will have their side faces 22 abut friction lining 6 directly and retain lining 6 in its position. Friction linings 5 and 7 may now be inserted through gap 19 moved up to side faces 23 of supporting elements 17 and will thus abut steps 24. The supporting elements 17 which support friction lining 6 in a circumferential direction are now axially secured in position. Friction linings 5 and 7 are, on their part, secured by additional supporting elements 17, these supporting elements 17 having abutting their side faces 22 abutting friction linings 5 and 7. In this manner, friction lining carrier member 13 is filled until friction linings 1 and 11 are secured, on their part, by supporting elements 17 lying on the right and on the left of gap 19. When friction lining 12 is inserted in gap 19, supporting elements 17 are secured in their axial position on the right and on the left of gap 19, since friction lining 12 will abut steps 24 of the four supporting elements 17. Gap 19 is closed by the clamping element 16 engaging--as shown in FIG. 3--with an extension 30 in a radially outwardly extending groove 29 of friction lining carrier member 13. Clamping element 16 is constructed relative to member 13 such that it embraces friction lining 12 at one rim thereof. The construction is chosen such that clamping element 16 completes outer groove 14 of member 13 and such that friction lining 12 as well as the other friction linings, is kept in its position on friction lining carrier member 13. Clamping element 16 is secured radially relative to member 13 by means of an inserted clamping sleeve 31. Friction lining carrier member 13 is now fully assembled and ready for operation.
When the linings are worn out, the friction linings are renewed without need for special tools by opening gap 19 and taking out friction linings 1 to 12 and supporting elements 17 individually. Since bores 18 in friction lining carrier member 13 are through-bores, it is possible to knock out supporting elements 17 which may be stuck due to rusting or corroding by means of a punch or the like.
FIGS. 4 and 5 illustrate a supporting element 17, whose manufacturing is particularly easy. As can be seen from FIG. 5, a supporting element 17 is in the form of a bolt with two portions 20 and 28 of different diameters. Portion 28 is machined to provide a substantially rectangular head 21. Step 24 is then obtained by a simple milling operation.
The illustrated form of friction lining carrier member 13 provides a simple and quick replacement of friction linings 1 to 12 resulting in a considerable shortening of the servicing time compared to the arrangements known in the prior art.
Since supporting elements 17 and clamping sleeve 31 can be used several times, a remarkable savings of material is obtained in addition to the saving of time.
In FIG. 6, a modified clamping element 16' with a radially arranged clamping sleeve 31 is shown. Groove 29 of FIG. 3 can be eliminated in this construction and clamping element 16' can be manufactured in a simpler way then element 16 of FIG. 3 and thus at lower cost because the necessity for extension 30 is eliminated which has to be machined very precisely.
Another clamping element is illustrated in FIG. 7. Clamping element 16" includes two bores 32 and 33 separated a given distance x in the circumferential direction and axially situated on the same level. Bores 32 and 33 continue into friction lining carrier member 13 and are aligned with the central point thereof, thereby forming an angle relative to each other. A resilient cramp 34 having two legs 35 and 36 have a given distance y separating each other are inserted in bores 32 and 33 deeply enough such that both legs 35 and 36 will be positioned in friction lining carrier member 13. Since the distance x of the bores is greater than the distance y, both legs 35 and 36 are operatively fixed in bores 32 and 33 and, hence, secure clamping element 16". Cramp 34 is secured radially as well, since the distance between the inlets of the two bores 32 and 33 is larger than the distance between the portion of the two bores 32 and 33 in member 13, and cramp 34 therefore, has to be bent upward when lining 12 is taken out radially.
While I have described above the principles of my invention in connection with 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 my invention as set forth in the objects thereof and in the accompanying claims.
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A carrier member for replaceable friction linings for clutch-type disc brakes wherein the friction linings are guided and held radially relative to a brake disc by a positive engagement with grooves in an adjacent surface of the carrier member with the friction linings being supported in the circumferential direction relative to the disc by supporting elements connected to the carrier member. The supporting elements engage bores in the carrier member perpendicular to the adjacent surface and are held in their mounted position by a friction lining overlapping an edge of the adjacent supporting element.
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BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for crimping cables, particularly cables made of synthetic plastic filaments. Even more particularly, this invention relates to a crimping apparatus provided with a compression chamber.
Crimping of cables formed of synthetic plastic filaments in mechanical compression chambers takes place in practice at the present time at operation speeds up to 300 m/min. A number of filament bundles are pulled out from a container and are combined into a cable which is fed with an overall size of up to 4,000,000 dtex into the compression chamber. The operation of the apparatus is carried out in such a fashion that the starting end of the cable is inserted into the gap between the pressing rolls when the apparatus is non-operative, and then the speed of the movable components of the apparatus is increased.
Such methods of crimping cables have been already described. In conventional methods, however due to the intermediate storage of the cable in the containers there have been losses. With these methods, the newly spun synthetic filaments are stretched in a continuous process, then crimped and eventually cut off to a size suitable for staple. It must be natural to assume that the insertion of the cable into the compression chamber should be carried out at a full operational speed. With customary dry spinning methods, the spinning speed is 500 m/min or higher so that, with a stretching ratio from 1 to 4 for the stretched cable, the speed of at least 2,000 m/min results. However, it has been very difficult or practically impossible with conventional mechanical compression chambers to insert the cable into such a chamber with the above speed.
German Pat. No. 1,816,028 discloses a crimping apparatus with a compression chamber in which one of the pressing rolls together with the pivotally positioned intermediate element, which closes the chamber in the operative position, is supported on rocking arm so that the pressing roll is pivoted out from the operation position. Thereby the cleaning and maintenance of the compression chamber are facilitated. The publication, however does not suggest that a cable could be inserted into the open compression chamber while the motors of the device are switched on. Obviously the insertion of the cable during the operation of the motors into the open compression chamber is not possible in the disclosed device because lateral access to the chamber is blocked by the machine components.
German Offenlegungsschrift No. 1,435,365 discloses an apparatus in which the compression chamber is formed by two suspended compression rolls and in which a gap between the rolls can be freed at one side by returning flaps provided on the side plate. However, there is no suggestion that the compression rolls could be moved away from the operative position to provide an enlarged gap between the rolls.
A crimping device for crimping synthetic plastic filaments has been also disclosed, for example, in applicant's U.S. Pat. No. 3,887,972.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved apparatus for crimping synthetic cables.
It is another object of this invention to provide an apparatus in which the cable can be inserted between the pressing rolls at full speed during a continuous spinning-stretching operation.
These and other objects of the invention are attained by a crimping apparatus for crimping synthetic plastic cables, comprising two rotary pressing rolls positioned relative to each other with a gap therebetween and forming a compression chamber at said gap, said rolls cooperating with each other to crimp a cable inserted into the compression chamber; two side plates and two intermediate elements enclosing said compression chamber at four sides thereof; means for displacing one of said pressing rolls and one of said intermediate elements enclosing said compression chamber from an operative position to a readiness position so as to enlarge said gap and open said compression chamber longitudinally and to provide between said rolls in said readiness position a passage for the insertion of the cable into the open compression chamber without requiring to stop the apparatus; and a housing having two housing portions each enclosing a respective pressing roll, said one pressing roll being connected to the assigned housing portion for displacement therewith in a concentrical recess in a respective one of said housing portions and means for securing each said ring in an adjusted position within the respective housing portion.
The displacing means may include a rocking member, said one roll having an axis, said one roll and said one intermediate element being supported on said rocking member which is pivotable about an axis which is parallel to the axis of said one roll.
Each of the rolls may have an individual drive motor, the drive motor of said one roll being supported on said rocking member, which makes possible the displacement of the pressing roll into the ready-to-operate position during the running of the apparatus.
The pressing rolls may be supported in the apparatus in an overhung position, whereby the front side of the apparatus becomes accessible in the ready-to-operate position for the insertion of the cable into the compression chamber.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic front view of a crimping device with a compression chamber in an operative position;
FIG. 2 is a sectional view along line II--II' of FIG. 1;
FIG. 3 is a detail of FIG. 1 on an enlarged scale;
FIG. 3a is a detail of FIG. 3 showing the device in a ready-to-operate position;
FIG. 4 is a sectional view taken along line IV--IV' of FIG. 3;
FIG. 4a illustrated a section taken along line IVa--IVa' of FIG. 3a;
FIG. 5 is a front view of the compression rollers of the device of another embodiment of the invention;
FIG. 5a is a detail of FIG. 5 of the device in a ready-to-operate position;
FIG. 6 is a section taken along line VI--VI' of FIG. 5; and
FIG. 6a is a section taken along line VIa--VIa' of FIG. 5a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings in detail, two slender compression rolls 2 and 2' are positioned in a compression chamber 1. The axes of rolls 2 and 2' extend through a common horizontal plane. Compression roll 2 is suspended on a shaft 3 in a frame which includes a bottom plate 4, a fork-shaped vertical front plate 5 and a cover-like rear plate 5'. Compression roll 2 is driven by a motor 7 via a gear belt 6 which runs behind the rear plate 5'. Motor 7 is positioned above the frame. Compression roll 2' is suspended on a shaft 3' which is supported in a bearing bush 8. The latter is rigidly connected to two arms 9, 9' spaced from each other and to an axle 10 so that bush 8, arms 9,9' and axle 10 form a single rigid unit which is pivotable in bearings 11, 11' as a rocking member. Bearings 11, 11' are supported in plates 5,5' via the compression roll 2'. The front plate 5 and rear plate 5' are each provided in the vicinity of shaft 3' with a wide cutout 12. Compression roll 2' is driven by a motor 7' via a gear belt 6' which runs behind the rear plate 5'; compression roll 2' is driven synchronously with the compression roll 2. Motor 7 is disposed above axle 10 on the arms 9,9'. Motors 7,7' are substantially symmetrically positioned in respect to a vertical plane 13 extended through a gap between the compression rolls 2,2'. A piston-cylinder unit 14 is, on the one hand, connected to a support 15 provided on the bottom plate 4, and, on the other hand, to the extension of arm 9.
As can be readily observed from FIGS. 3, 4, 3a and 4a, the compression chamber 1 is at its four longitudinal sides limited by the front side plate 16, a cover-like rear side plate 16' and two intermediate elements 17, 17'. Both side plates 16, 16' cover the gap formed between compression rolls 2 and 2' in the operative position of the crimping device. Thbe edges 70, 70' of plates 16, 16 facing towards the compression roll 2' extend vertically. Each plate 16, 16' at the side thereof, opposite to the vertical edge, is provided with a foot or projection 18. Intermediate elements 17, 17' have sharp edges 20, 20' extended in the proximity of the gap between the compression rolls, which edges are arranged as peeling-off blades relative to the outer surfaces of the compression rolls 2, 2'. Usually the shape of the intermediate element 17 is adjusted to the shape of foot 18, and the intermediate element 17' is arranged mirror-inverted relative to the element 17.
The intermediate element 17 forms with plates 16, 16' a rigid integral unit. This unit simultaneously serves as a spacer and is adapted for maintaining a narrow gap between the side surfaces of compression rolls 2, 2' and the upper surfaces of plates 16, 16' facing towards those side surfaces.
Each plate 16, 16' has a vertically extended bore 21 which is closed from above and extends downwardly up to edges 20, 20'. A horizontal bore 22 provided in each plate 16, 16' merges into each vertical bore, respectively. Bore 22 is provided with a thread connection for a hose to be connected thereto. Bores 21 are connected by oblique passages with openings 23 and vertical grooves 24. Openings 23 face the side surfaces of compression rolls 2, 2'. Grooves 24, 24' overlap the narrow gap between the compression rolls 2, 2' and intermediate elements 17, 17'.
The unit formed of plates 16, 16' and the intermediate element 17 is connected to a holding plate 26 provided with a support member 25 by means of a rotary pin and is adjustable by screws 27, 28. The holding plate 26 is screwed to the front plate 5 of the housing frame.
The intermediate element 17' is adjustable in the same fashion (although it is not shown in the drawings) on a rocking arm 29 which is pivotable or swingable about the axis of compression roll 2' by means of a bush 30. A piston-cylinder unit 31 shown in FIG. 1 is engaged at the side of the intermediate element 17' facing away from the compression chamber 1; piston-cylinder unit 31 is connected to the arm 9 through a support 32 extended through the cutout 12.
In the operative position, the compression chamber 1 is tightly surrounded at all four longitudinal sides by the side plates 16, 16' and intermediate elements 17, 17'. The outer surfaces of both rotating compression rolls 2, 2' from therebetween a narrow gap through which a cable to be crimped is pressed into the compression chamber. Air is blown through bores 22; air partially flows through openings 23 into the narrow intermediate space, formed between the side plates 16, 16' and compression rolls 2, 2', and partially through grooves 24, 24' into the gap between intermediate elements 17, 17'. Air is blown through the system for cooling and also for preventing the penetration of individual filaments into the narrow gap.
FIGS. 3a and 4a illustrate the device in the ready-to-operate position. In this position, compression roll 2' is pivoted from its operative position about an angle α. The pivoting takes place about the axle of bearings 11, 11' upon the actuation of the piston-cylinder unit 14. The intermediate element 17' is displaced together with compression roll 2' from the operative position to the pivoted-out-position so that the chamber 1 opens at its respective longitudinal side. A side passage 33 then occurs between the pivoted components and the stationary components of the device. A cable can now be inserted through this passage into the open compression chamber 1 in the direction of arrow 34 from the front side of plates 16, 16' at a full speed, for example, by means of the conventional suction injector. Finally, compression roll 2' is brought again to the operative position, the cable is lopped off below the compression chamber, the intermediate element 17', which was released in the ready-to-operate position, is again pressed by the piston-cylinder unit 31 and the crimping operation starts.
In the embodiment illustrated in FIGS. 5, 6, 5a, 6a, compression rolls 2, 2' are supported and driven in the same fashion as that described in connection with FIGS. 1-4. The compression rolls 2, 2' are each supported in a respective housing half 40, 40'. Each housing half or portion 40, 40' has the shape of the circular disc concentrical with the respective roll and with a segment cut off in the plane parallel to the plane 13 extended through the gap between compression rolls 2 and 2'. The housing portions 40, 40' are mirror-inverted relative to each other, whereby at the boundary position each portion lies closer to the compression roll 2' in a pivoted-out position thereof to the stationarily suggested compression roll 2. Each housing portion 40, 40' has a bottom plate 41, 41' and a cover plate 42, 42' bolted to the respective bottom plate. Plate 41 is flanged to the front plate 5 while plate 41' is flanged to the bearing bush 8.
Side plates 43, 43', made out of wear-resistant material and being interchangeable, are inserted in bottom plate 41 or cover plate 42 of the housing portion 40. Intermediate elements 44, 44' are positioned in concentrical recesses provided in plates 41, 41' and are clamped between the opposing faces of plates 41, 41' and 42, 42' by bolts 102, these intermediate elements each having the shape of a ring with a cut-off segment. The cut-off surfaces 45, 45' of intermediate elements 44, 44' form below the axes of the compression rolls two lateral boundaries of the compression chamber 1. Respective surfaces 46, 46' of the intermediate elements 44, 44' limit an inlet passage 47 extended through the plane 13. The inlet passage 47 is somewhat wider than the chamber 1 and the latter is slightly constricted in the downward direction in wedge-shaped manner. The angle of the wedge can be adjusted because the intermediate elements 44, 44' can be slighlty turned and thus adjusted in the corresponding concentrical recesses of plates 41, 41' which form the guides for these intermediate elements and can be then clamped by the bolts again. Screws or bolts 48, 48' which are accessible through the slots 12 in the edges of plates 41, 41' and screws 50, 50' serve for adjusting of the intermediate elements 44, 44'.
The intermediate elements 44, 44' are provided with the inner eccentrical recesses which form passages 51, 51'. Only a very small gap, which can be precisely adjusted upon the actuation of screws 50, 50', is formed between the opposing end faces 49, 49' of two intermediate elements 44 and 44' and the outer surfaces of the respective compression rolls 2, 2'. The relatively wide passage 51, 51' is formed between the inner peripheral surface of the respective intermediate element and the assigned compression roll at the side thereof facing away from the gap between the rolls. Additional enlarged recesses 52, 52' formed in the inner faces of the intermediate elements 44, 44' are positioned below the axes of compression rolls 2, 2'. Bores 53, 53' open into passages 51, 51', which are supplied with pressure air in the same manner that was described for FIGS. 3 and 4. The pressure air can escape only into the region of the compression chamber 1 and serves to efficiently cool the components of the device and to prevent filaments from penetration into the critical gap. Plates 41, 41' are provided in the regions of enlarged recesses 52, 52' with closeable openings 54, 54' similarly to openings 21 of FIGS. 3 and 4. Penetrated filament dross can be blown out through these openings. Rolls 2 and 2' are displaced in the same fashion as the compression rolls of the first embodiment.
The housing which in the operational position is fully closed opens in the manner described for FIGS. 1-4 so that in the ready-to-operate position shown in FIGS. 5a and 6a, passage 33 is free to receive a cable which can be inserted into the open inlet passage, the enlarged gap between compression rolls 2 and 2', and into the longitudinally open compression chamber 1. Compression rolls 2, 2' remain thereby practically completely enclosed or covered.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of crimping devices for crimping cables differing from the types described above.
While the invention has been illustrated and described as embodied in a crimping device for crimping cables, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
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An apparatus for crimping cables formed of synthetic filaments during a continuous spinning-stretching process includes two pressing rolls which form a crimping chamber into which a cable to be crimped by the rolls is inserted. One of the rolls is displaced from an operative position to a readiness position at a full apparatus speed. Upon displacement of the pressing roll into the ready-to-operate position, a gap between the rolls becomes wider and the crimping chamber opens longitudinally so that a passage is formed, which allows the cable to be inserted into the chamber from the front side thereof by means of a suction injector.
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FIELD OF THE INVENTION
This invention relates to the field of vehicle location monitoring systems.
STATE OF THE ART
There are several known approaches to locating a vehicle. These can be broadly grouped into four classes.
The first approach resorts to triangulation. The area travelled over by the vehicle is covered by a limited number of beacons. Either these beacons transmit signals which are received then compared by the vehicle or a signal is broadcast by the vehicle and picked up by the beacons. In either case, the physical location of the beacons must be known and the actual location of the vehicle is derived from a comparison of some physical characteristic of the received signals. Satellite systems also fall within this approach, since although the beacons (the satellites) are moving, their orbits are known with great precision.
The second approach resorts to proximity detection. The area travelled over by the vehicle is covered by a dense network of beacons, each one with limited coverage, either in range or in angular sector. The actual location of the vehicle is derived from the knowledge of which beacons are within radioelectric range of the vehicle.
The third approach resorts to dead reckoning. No ground facilities are required. Instead, the vehicle's current location is derived from a knowledge of its initial location and heading supplemented by integration over distance or time of suitable information about its course. An example of this approach is inertial navigation as used by certain ships and aircraft.
A fourth approach stems from a knowledge of constraints placed on the places which can be occupied by the vehicle, this approach removes a degree of uncertainty about where the vehicle is actually located as derived from some physical measurement made on the vehicle itself, such as distance travelled.
A typical representative of the fourth approach is a system used for monitoring the location of urban transit buses. Given the line or route number and the distance travelled since leaving the terminal, it is trivial to locate a bus. A number of systems have been proposed, which fall basically into this fourth "corridor" approach, while borrowing some elements from a crude dead reckoning mechanism. Of relevance are, in particular, a system described in U.S. Pat. No. 3,984,806 MARCONI and a system described in the U.S. Pat. No. 3,789,198 HENSON. In both of these systems, an exhaustive knowledge of all drivable surfaces is essential. In MARCONI, this description takes the form of a graph. Its nodes are junctions; its branches are segments of roads or streets between junctions. The branches are described by their length and the identity of the nodes which they link. The nodes are described by the identity of the branches that they terminate and by the relative angles between those branches. Knowing its initial position, a vehicle determines that it is approaching a junction when the distance travelled as indicated by its odometer is almost equal to the length of the current branch. It then makes a crude estimate of the variation of its heading to guess which new branch is being taken, and then relies on its odometer until it thinks that it has reached the next junction. In HENSON, the description of the corridors stored in the vehicle is more complete since a memory contains the coordinates of drivable surfaces; for example, a grid network is overlaid on a map of an area, each grid intersection is assigned a memory position, to which a value of 1 is given if the grid intersection coincides with a street, roadway or alleyway. The location monitoring system comprises a dead reckoning system, which outputs an estimated location, which is then corrected to the nearest drivable surface if the above-mentioned memory shows that the estimated location is not drivable.
The systems which have been proposed so far suffer from a number of drawbacks.
The drawbacks of the first approach are the following. It requires ground facilities, the high cost of which can hardly be justified for a small number of vehicles. It makes use of radio channels. If the bandwidth is large, this requires a large amount spectrum, which is a scarce commodity. On the other hand if the bandwidth is narrow, this results in poor location accuracy. If the signals are transmitted by fixed beacons and received by the vehicles, the vehicles must be equipped with fairly elaborate measurement apparatus and computing power. On the other hand if the signals are transmitted by the vehicles and picked up by the fixed beacons, channel congestion can only be avoided through a limitation either on the number of vehicles which can be monitored by the system or on the frequency with which the location of each vehicle can be monitored. The narrower the channel, the tighter the limitation.
The drawbacks of the second approach are the following. It requires the building of an extensive grid of beacons, not to mention the network which may be required to connect them to a monitoring station. The location accuracy may vary, due among other reasons to multi-path propagation, which is a common phenomenon in urban areas. Of course, the beacon range can be limited, for instance through burying inductive loops into the causeway, but then the cost is even higher. Or one can use highly directive radioelectric or optical beams, but then a vehicle can be masked by other vehicles.
The drawbacks of the third approach are the following. Errors made in the measurement of physical parameters are usually cumulative, so that the location accuracy drops sharply with time or with distance covered. Some military equipment uses highly complex and costly apparatus to mitigate the problem of cumulative errors but, even then, other forms of localisation system are required from time to time to obtain an accurate "fix".
The drawbacks of the fourth approach are the following. Either it is used by vehicles with limited freedom of action, e.g. busses (so long as there are no traffic diversions), or else an exhaustive description (e.g. of an entire city street plan) is required which constitutes a technical or economical obstacle to practical implementation.
Preferred embodiments of the present invention provide a vehicle location monitoring system of high accuracy and low cost, and that does not require any ground facility nor radioelectric means and that does not place any rigid constraints on the permissible paths followed by a vehicle.
SUMMARY OF THE INVENTION
The present invention provides a vehicle location monitoring system consisting of a primary system and a secondary system. The primary system updates an estimated location from an initial known position and heading by integrating elementary motions, as determined by measurement apparatus carried by the vehicle. The secondary system corrects the estimated location and, if need be, the estimated heading and any other parameter which may be used in the process (e.g. tire circumference). The secondary system performs its corrections on the basis of a knowledge of areas where the vehicle cannot be located and which consequently can only figure in the estimated position as a result of the accumulated dead reckoning errors of the primary system. Unlike known localisation systems based on a knowledge of all drivable areas, the use of "forbidden" areas for the sole purpose of correcting a primary system makes it possible to use a subset only of those areas where the vehicle cannot actually be as "forbidden" areas and even to use a stylized representation of those areas such as, for instance, a circle representing a block. The representation of the "forbidden" areas may be graphical or digital.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood with the following description of a preferred embodiment with reference to the accompanying drawings. This description is solely intended to help understand the invention and the invention is not limited to the preferred embodiment. In the accompanying drawings:
FIG. 1 is a block diagram of a location monitoring system in accordance with the invention and a possible layout of its constitutive parts on a vehicle on which it is installed;
FIGS. 2 and 3 are two orthogonal schematic views of a possible implementation of a sensor and its installation on a half-axle;
FIG. 4 is a plan view of a first implementation of the forbidden areas descriptor;
FIGS. 5 and 6 are two orthogonal views of a possible implementation of a display and control panel;
FIG. 7 is a block diagram of a circuit that yields a coarse value of the angular difference between two wheels, based on the indications of wheel sensors;
FIG. 8 is a block diagram of a circuit that improves the accuracy of the measurement of the FIG. 7 circuit; and
FIG. 9 is a block diagram of a path allocation system for a plurality of vehicles linked by radio connection to a central point, said path allocation system being based on a location monitoring system in accordance with the invention.
DESCRIPTION OF PREFERRED EMBODIMENT
The location monitoring system comprises a processor OC, two wheel sensors CG and CD from which the angular positions of the left rear wheel and of the right rear wheel of the vehicle can be derived and a forbidden areas descriptor DZI. The system is also provided, for the driver's convenience, with a display and control panel PCV.
Each of the two wheel sensors CG and CD is arranged in the following way (FIGS. 2 and 3). A toothed disk is rigged to a half-axle DE connecting the differential to a wheel. The disk is divided into angular sectors distinguished by slots and teeth. One slot and one adjacent tooth comprise what will be referred to as one step of the toothed disk CC. Two optical switches B1 and B2 are each made of a light-emitting diode (LED) and a phototransistor. They are set up in such a way that the teeth of the disk intercept the beam but the slots do not. The angular off-set between the optical switches is (n+1/2) times one half-step.
The forbidden areas descriptor DZI (FIG. 4) comprises a transparent film PZI with opaque areas corresponding to a graphical, stylized and non exhaustive representation of "forbidden" areas and a spot read-out device carried by anassembly which is movable relative to the film. The movable assembly is made in two parts. On one side of the film, it comprises a spot light source, e.g. an LED, the image of which is focused by a lens OP on a point of the film PZI. On the other side of the film it comprises a photodetector (not shown). The movable assembly further comprises two trays which move in perpendicular directions. The first tray carries the spot read-out device and moves in one direction along two lead-screws VF1 and VF'1 rotated by a toothed belt CC1 driven by a stepper motor M1.
The second tray carries the first tray together with its drive and itself moves in a perpendicular direction along two lead-screws VF2 and VF'2 rotated by a stepper motor M2.
By properly energizing the motors M1 and M2, the spot read-out device can be brought above that point of the film which corresponds to the estimated vehicular location. By detecting whether this point is opaque or transparent, the spot read out device can indicate whether the estimated position is within a forbidden area or not.
The opaque areas of the film PZI correspond to a non-exhaustive stylized representation of forbidden areas, that is to say that they do not correspond to all those areas where the vehicle cannot actually be located but to only some of them. In addition, these selected areas are not represented with their actual shape but with a simplified outline. The opaque parts may correspond, for example, to geometrical figures inscribed within some only of the blocks of a city, (e.g. the larger blocks, or parks, or sea etc)
The display and control panel PCV comprises the following items (FIG. 5): a light source S projects the image of a portion of an area map PZ through a lens 0 and, optionally, via a rotating prism PT onto a mirror, not shown, which reflects it onto a screen E, (FIG. 6) facing the driver of the vehicle. Next to this screen, a number of switches and indicator lamps serve to provide communication between the driver and the localising system.
The area map PZ is moved with respect to the lens system under the control of two stepper motors M3 and M4 which, via toothed belts CC3 and CC4, rotate lead screws VF3,VF'3 and VF4,VF'4, thus moving the tray to which the map PZ is fixed. The area map PZ may contain several pictures of the same area, which differ in scale and the amount of detail shown. Scale switching is performed under the control of keys (O,O); the area map then moves in such a way that the image remains centered on the same geographical point.
The optional rotating prism PT allows for a rotation of the map image so that the heading of the vehicle remains unchanged with respect to the screen, e.g. the vehicle is always represented as heading towards the top of the image.
Alternatively, if there is no rotating prism PT, or if it has been disabled under manual control, the image may be oriented with North at its top.
The control and display panel may be equipped with a heading indicator, not shown here. This indicator consists of a number of LEDs whose image is overlaid on the screen by means of a lens system and, possibly using a mirror. This indicator may be used to display the heading of the vehicle. If the processing unit of the location monitoring system is provided with a program to determine a critical path, the indicator may also be used to display the route to be followed or, if the scale is not adequate, a part of that route.
I will now give a more detailed description of the operation of the location monitoring system.
The optical switches B1 and B2 associated with a slotted disk CC (FIGS. 2 and 3) indicate the angular position accurate to within 1/8 of the size of the disk. This is because, when the slotted disk CC rotates through an angle that is equal to one step, optical switches B1 and B2 each go through one complete cycle between open and close and close and open, but at positions of the slotted disk CC which are not the same since optical switches B1 and B2 are off-set by an odd number of quarter steps. The illumination of the photodetectors of the optical switches B1 and B2 thus enables to define four states, all four of which are gone through by the outputs of optical switches B1 and B2 when the slotted disk CC rotates through one step. The order of the transitions between these four states indicates the direction of rotation since each one of these states corresponds to an angle of 1/4 step, the angular position of the slotted disk CC is therefore known to within about 1/8 step. Thus, for a disk with sixty four slots, the shaft position is known to within 1/512th of a turn.
Knowing the diameter of the tyres, one can associate a distance run with each angular motion of 1/4 of a step. The processing unit OC can then sum these incremental distances and thus give the distance travelled by the left wheel, by the right wheel and, if so desired, by the differential.
The heading of the vehicle can be derived from a measurement of the difference between the angular positions of the left and right wheels, by multiplying said difference by the ratio of the tyre radius divided by the track of the back wheels.
Counting the slots of the left and right disk gives a coarse estimate of the difference between the angular positions of the wheels, accurate to within 1/4 of a step. A time base makes it possible to refine on this measurement, hence on the knowledge of the heading, as soon as the vehicle is moving at not too slow a speed. An example will help understand this point. Assume that, for the initial heading the optical switch B1 of the left wheel and the optical switch B1 of the right wheel turn on and off simultaneously. Further, assume that the vehicle comes slightly to its right and then follows a steady course. While the vehicle is turning, the left wheel is rotating slightly faster than the right wheel. When the heading bcomes steady, so does the angular difference. The transitions of the optical switch B1 of the left wheel will now occur slightly ahead of time with respect to those of its right wheel counterpart. The ratio between the period of time when one of the optical switches is on and the other is off to the duration of one step, that is to the time elapsed between two successive on-off transitions of the same switch, indicates by what fraction of one step the left wheel is now ahead of the right wheel FIGS. 7 and 8 show an embodiment of a circuit for performing this calculation.
FIG. 7 is a block diagram of a circuit for determining the angular position to within 1/8 of a step. In the figure, FPLS designates a programmable logic sequencer such as Signetics™ type 82 S 105. It takes output signals from the optical switches B1 & B2 as input transitions. It has eight internal states corresponding to quarter steps, each quarter step comprising a transient state which only lasts for the duration of one clock period applied to the sequencer, and a stable state which lasts until the next transition in the signals from B1 & B2. S and T comprise two outputs from the sequencer FPLS. The output S indicates the direction of rotation, while the output T is a "pip". that marks the duration of the transient state. The outputs S & T are connected to respective inputs of an up/down counter UDC whose outputs indicate the angular position in 1/4 steps.
FIG. 8 is a block diagram of a circuit for estimating the amount by which one wheel has shifted relative to the other, on the basis of pulses T1 & T2 derived from two optical switches, each associated with a corresponding one of the wheels.
In the figure, D1 represents a count down circuit which is initialised on the appearance of a pulse T1 to a value contained in a register R1. The count down circuit D1 is re-initialised each time its count reaches zero, such that together with the register R1 it constitutes a circuit for dividing a series of clock pulse at its clock input C by the number stored in the register. The divided output pulse train appears at its output E and is applied to the clock input of a counter C1. The counter C1 is reset to zero by each pulse T1, which also has the effect of loading a register R2 with the value present in the counter C1 immediately before it is reset. A second down counter D2 and up counter C2 are arranged with respect to the register R2 in substantially the same way as the first down counter D1 and up counter C1 are arranged with respect to the register R1. The counter C2 counts at the rate of said clock pulses C, but divided by the value contained in the register R2. The count reached by the counter C2 on the appearance of pulse T2 is loaded into a register R3 by said pulse T2.
The count loaded into the register R3 is representative of the ratio between the time elapsed between two transitions on two different wheels and the time elapsed between two transitions on the same wheel. The first-mentioned time defines the counting interval, while the counting frequency is inversely proportional to the second-mentioned time. The scale is such that when these times are equal, the value contained in R3 is equal to that in R1 (to within one counter step). It is convenient for this value to be a power of 2, but it may be adjusted to take account of inequalities in tooth sizes for example.
Thus, by virtue of the circuit shown in FIG. 7, optionally supplemented by the circuit of FIG. 8 to improve accuracy, the processor OC is provided with means for detecting the distance run and the heading. It obtains this information by observing the up/down counter UDC and the register R3, either continuously, or in response to an interrupt derived from the up/down counter UDC, e.g. once per turn of the wheel.
The processing unit OC is thus able to compute the distance travelled and variations in heading. If it if fed with the initial location and heading, an integration program will give the estimated location. The processing unit OC can accordingly move the movable assembly of the forbidden area detector DZI.
It may happen that the photodetector PD of the assembly DZI detects one of the forbidden areas. This may result from poor accuracy in measurement or in computation, from the vehicle skidding, from side winds, from a badly cambered road, or perhaps from an incorrect value for one of the parameters which describe the vehicle, such as the tire circumference.
In this case, a correction program will be called upon. The estimated location is moved perpendicularly to the heading by an amount equal to the unit length used in the dead reckoning program, typically corresponding to one revolution of a wheel. The direction of the correction is obtained from the direction in which the photodetector PD must be moved to keep it out of the forbidden area (because the motors used are of the stepper variety, the actual motion of photodetector may be only roughly perpendicular to the heading).
The location correction which has been just described is not the only correction performed by the processing unit. The estimated heading is also corrected, by a very small amount, in the same left or right direction as the location correction. In addition, the heading corrections are accumulated over a certain distance. If this accumulated value exceeds a preset threshold, this may point to a poor knowledge of the relative pressure or wear of the left and right tires. Consequently, the processing unit will increment or decrement the value by a very small constant which it adds to the estimated heading say for each revolution of a wheel.
Moreover, although the preceding correction may compensate for a difference in pressure or wear, it may happen that, because the value used for the diameters of both types is either too large or too small, due, for instance, to wear or to pressure variation, the estimated course still collides with a forbidden area. Such a situation may arise shortly after a turn coming after a long straight line. The processing unit still makes a correction to the value used for the tire diameters. To this end, it logs the estimated location, say every mile travelled. When performing a location correction, the processing unit multiplies this correction by the cosine of its angle with the recent average course. If the sum of such values exceeds some threshold, say 50 feet for 10 miles travelled, the processing unit will slightly modify the value used as the tire diameters.
In another embodiment of the forbidden area descriptor DZI these areas are represented in a memory, for example as circles inscribed in blocks or fields which are defined by their radii and the coordinates of their centers. Should the estimated course cross into such a circle, a correction is performed, perpendicular to the heading and toward the outside of the circle, as determined from the angle between the heading and the vector linking the location to the center of the circle.
The location first estimated from the dead reckoning system which integrates data acquired from the position of the wheels, then corrected as discussed from possible infringements of forbidden areas, is the current location of the vehicle.
There are several applications to which a knowledge of a vehicle's position to the accuracy provided by the present system (a few meters) can be applied. One particular application is indicating a recommended route to reach a chosen destination. For this purpose, the display and control panel PCV is provided with keys for moving over the map a marker that normally indicates the position of the vehicle. It also includes a key for indicating that the position of the marker on the map is the desired destination. To make this destination indicating operation quicker and easier, the area through which the vehicle is moving can be displayed on the map PZ several times at different scales showing different degrees of detail, as can be seen in FIG. 5. Further keys (O,o) on the display and control panel PCV are used to switch scales, with the processor making sure that the marker continues to designate the same geographical location at each scale, or else refusing to change scale if the location is not available on a map at the chosen scale.
The display and control panel PCV also includes means (not shown in FIG. 5) for indicating a recommended route. These means comprise a set of LEDs in a lens system for superposing the image of the LEDs on the screen E, together with means for selectively lighting the LEDs so that the image of the lighted diodes on the map corresponds to the chosen route.
The processor OC is additionally provided with a digital memory storing the co-ordinates of a directed graph which represents a selection of node points in the area through which the vehicle travels, together with weighting factors associated with the branches between nodes to give an estimate of the time needed to run along them. To determine which route to recommend, the processor OC uses a shortest path search algorithm in three parts. The first part consists in estimating the time required for the vehicle to travel from its present location to the immediately surrounding nodes, as though there existed direct arteries for it to follow. The second part uses the same procedure to estimate the time required to reach the target point starting from its immediately surrounding nodes, again assuming that there exist direct arteries to follow. The third part comprises an algorithm for critical path analysis of the kind conventional to operations research (e.g. the Dantzig or the Ford-Fulkerson algorithm) to find the best path through the selection of stored node points.
Different weighting factors may be associated with each branch between nodes, corresponding to different traffic conditions for example, and the appropriate factor would then be chosen as a function of traffic conditions. Alternatively, the memory may be a read/write memory, to enable the weighting factors to be up-dated from periodic broadcasts from a control center.
The control center can up-date its own store of weighting factors from any conventional network of traffic detector means, e.g. vehicle counters, but advantageously it will include means for up-dating the store on the basis of radioed reports from a fleet of vehicles. If the vehicles are equipped with the same route-recommending system, this up-dating can proceed automatically.
Thus each vehicle is capable of: identifying the node points of the graph near to its current location; of noting the times at which it passes through or at least close to, each node point; of determining whether it is, in fact, following a path corresponding to stored branch; and finally, if it is following such a branch, of noting the time taken to travel along it. The vehicle is thus capable of determining up-to-date branch travel time data. This data can be relayed to the control center on request or as soon as it becomes available. The request may have the form: "will all vehicles located within one mile of the following node point report the most recent branch travelled and the time taken". The vehicles should reply in a predetermined order, e.g. as a function of their distance from the relevant node point. The request may alternatively be more restrictive, e.g. only requiring replies from vehicles that have a travel time which differs by more than 30% from the last broadcast travel time.
Another useful application of the location system consists in reconstituting the path travelled. This requires a suitable memory to be added to the processor OC for storing the co-ordinates of a selection of the points passed through, together with the times of passage if required. For example, a record could be kept every 100 yds of the vehicle position and the time. Alternatively, a more detailed record could be kept, but only of the last mile travelled. Data thus accumulated could be read out by radio in response to an appropriate request, or onto some form of removable medium such as a magnetic cassette, or simply directly onto the vehicle display, e.g. after the vehicle has come to rest.
A further useful application of the location system stems directly from its accuracy, and concerns locating vehicles without a driver, e.g. vehicles that have been hired and left wherever convenient by their previous user. The location system, together with a radio transmitter/receiver system makes it possible to locate the nearest free vehicle to a specified point. A table of street numbers and an interpolation program then make it possible to translate the given location into an address that can be told to a new user. That, together with information concerning make, color and registration number, should make it no problem to find the vehicle, since it will be within a number or two of the given address. For a hire system, there remains a requirement that the approved person and no one else should be able to drive away the vehicle.
This needs an identification system to be added to the location system. This could work in response to a suitable badge, or else by means of a code keyed-in by the user. The processor would then be able to verify that the new driver is indeed the driver announced to it over the radio.
Such a hire system could make good use of the above-mentioned system for reconstituting the path travelled for charging purposes. This could go as far as automatically debiting the charge from said badge, if of the credit card type.
Another useful application of the vehicle location system consists in selecting one from a plurality of vehicles to go to a particular scene. This applies particularly to police cars and taxis, but doubtless other vehicle fleets could also find it useful.
A control station interrogates the fleet of vehicles on the road by radio. The vehicles reply as a function of their respective locations. In practical terms, to avoid over-loading radio channel capacity, this should be arranged as a function of distance (in time or miles) from the specified scene.
The above-mentioned applications of the vehicle location system can be achieved using the circuit shown in FIG. 9.
In the figure OC is the processor. It is connected by a bus B to a data transmission controller CT, an initializable reply counter DR, and time counter DT which is likewise intializable. A radio transmitter ER receives data to be transmitted TXD from the data transmission controller CT, and a send instruction via an input CE. A radio receiver RR supplies data it receives to the data transmission controller via an output RXD, and supplies an indication of carrier detection on an output DCD. The device also has three gates P1, P2 & P3.
The apparatus works as follows. When the processor wishes to reply to a received radio request, it initializes the transmission controller CT, it loads the reply counter DR with the maximum number of replies authorised by the station, and it loads the time counter DT with a calculated figure that is lower the greater the estimated value of its reply. By way of example, the factor could be proportional to the square of the distance of the vehicle from the point mentioned by the central station, with a constant of proportionality chosen as a function of the kind of broadcast request to which a reply is being made.
After initialization, the time counter counts down at a rate set by a clock signal H, omitting those periods of time for which the receiver RR indicates, via its output DCD, that the central station is still transmitting or that some other vehicle is replying. This count down continues for as long as the transmission controller indicates, via its output RTS, that it desires to send, and until the time counter DT or the reply counter DR counts down to zero. If the time counter DT is the first to reach zero while the signal on output RTS is still indicative of a desire to send, then the send signal is applied to the input CE of the transmitter ER via the gate P3, and to the controller via its input CTS.
Each reply from another vehicle that is received by the receiver RR causes the reply counter DR to count down one step, unless it has already reached zero, in which case the vehicle assumes that no reply is required from it since enough better-placed vehicles have already replied. In FIG. 9 this is achieved by the zero signal from the counter DR disabling the application of further clock signals H to the counters DR & DT by means of gates P1 & P2.
With operation as has just been described, it can be seen that all vehicles likely to reply to a given question start counting down together on the central station carrier being turned off. The vehicle that has the best estimate of the value of its reply, i.e. the vehicle that initialized its time counter DT with the lowest figure, is the first to reply. Transmission of its message inhibits the count down in all the other vehicles, unless there are two "first" vehicles that start transmitting at the same instant. In that case the central station will probably not be able to understand either message due to mutual interference, and the third best vehicle (perceived as the second best by the rest of the fleet) is the one that will be understood by the central station. So long as the geographical density of vehicles is uniform, and the figure stored in each time counter DC is proportional to the square of its distance from the focal point of the central station request, the probability of mutual interference by simultaneous vehicle replies depends only on the vehicle density and on the constant of proportionality (to which said probability is inversely proportional).
It should be noted that the system does not require identical bit rates to be transmitted by the central station and by the vehicles, nor does it require them to use the same kind of modulation.
The various applications that have been described of uses to which the location can be put are merely by way of illustration. The invention is not tied to any specific application.
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The system comprises two parts: a first part which operates on a dead-reckoning basis from measurements of, say, measured wheel rotations (CD,CG) and a knowledge of an initial starting point and heading; and a second part which applies corrections to the first. The second part operates on the basis of a simplified map of the area travelled by the vehicle, said map storing only representations of "forbidden" areas (DZI) where the vehicle cannot possibly go, e.g. parks, lakes, large blocks of buildings etc. . . . A judicious selection of forbidden areas can be stored in highly stylized (i.e. simplified) form and still provide adequate information to overcome the inaccuracies inherent to any dead-reckoning system. This requires far less accurate storage for the secondary system than would a map of areas where the vehicle can go. A processor (OC) performs the required calculations and a display (PCV) is optionally provided for the driver, since in some systems, e.g. fleets of police cars, the point of the system is not to tell the driver where he is, but to tell a central control station.
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BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to a method and apparatus for cleaning dust-laden, generally tubular air filters. The invention involves spinning the filter within a closed cabinet, while simultaneously reciprocating a close-coupled reverse air jet along its inner surface and applying suction to its outer surface, to dislodge the dirt accumulated on the filter paper.
Air Filters
As stated, the invention has to do with cleaning air filters. More particularly, the invention has been developed in connection with the large, cylindrical, hollow filters used in conjunction with the motors of heavy equipment, such as ore trucks, bulldozers and the like.
This type of filter comprises an annular, perforated, metal frame containing a permeable pleated paper filter medium. In the use of the filter, air is drawn into the motor through the permeable filter wall and thence through the central filter bore. Dirt entrained in the air is separated and accumulates on the exterior surface of the filter paper; the cleaned air passes into the motor.
The filters quickly become dirty and plugged in the dusty environment in which they are used. It is not uncommon for a newly installed, clean filter to become non-useable within 1-3 weeks.
When this occurs, the user must remove the soiled filter and replace it with a clean one.
These filters are expensive. They commonly cost several hundreds of dollars. Therefore, it is self-evident that cleaning the used filters to render them re-useable is desirable.
Commerical Prior Art
The only technique used commercially, to applicants' knowledge, is a "wet" process. It involves hanging a number of the filters from a wire grid and then suspending them for a pre-determined period in a bath of water containing surfactants. After the bath, the filters are removed and hosed down with water. As a last step, they are dried using a reverse air flow (i.e. an air flow moving outwardly from the centre bore of the filter, through its wall).
This "wet" process is characterized by certain disadvantages. Firstly, the water bath carries dirt to the inside surface of the filter paper, where it is not wanted. Secondly, contacting the filter paper with water results in the paper becoming somewhat brittle on subsequent drying, so that it becomes fragile and can easily break. And thirdly, the procedure often causes pinholes to appear in the paper, which soon render it defective for its intended purpose.
Because of these problems, the filters can only be so cleaned perhaps 2-3 times, after which they are commonly discarded.
Development of the Present Invention
Wishing to develop a better technique, applicants began by washing filters in water in a household clothes washer, in the course of which the filter was spun. The procedure was unsuccessful, as the filter paper was damaged. However, it was noted that spinning was useful in dislodging some of the dirt.
Applicants then constructed a spinner having spaced plates which could be tightened, to friction grip the end surfaces of the filter. This spinner was used to spin dry, soiled filters at varying speeds. There was some success in removing the larger dirt particles, but the fine particles, in particular, were retained by the filter paper.
Applicants then chose to assist the dry spinning with a reverse air flow. An open-ended air hose was inserted into the filter bore and simultaneous spinning and reverse air flowing was tried. It was found that good cleaning of the filter wall would occur in one localized area, but then most of the air would begin channelling through that spot. As a result, inordinately large volumes of air were required to increase the extent of the cleaned area.
At this point, applicants chose of bring a relatively low volume of pressurized air flow into close proximity with the filter wall. To accomplish this, a relatively long, hollow cylinder was mounted on the end of a reciprocable hollow shaft connectable to an air compressor. The cylinder was provided with a longitudinally extending line of radially directed nozzle outlets. The nozzles were positioned close to the inner surface of the filter. Stated otherwise, the air jets produced by the nozzles were "close coupled" to the filter wall. Typically, the nozzle outlets were spaced about 1" from the filter wall.
A cabinet was also provided, to enclose the filter and the nozzle cylinder. A vacuum unit was attached to an outlet from the cabinet, to exert suction on the exterior of the filter and draw off the dust-laden air.
This unit thus incorporated:
spinning of the filter;
close coupled, localized reverse air flows or jets which could be moved along the length of the rotating filter wall, to ensure that the whole surface was subjected to the localized flows;
and suction on the outside of the filter, to draw off dust-laden air and assist in dislodging the dirt from the paper surface.
It was found that this combination was effective to clean the wall. A key factor was that now the air supplied was no longer so free to move to a clean spot along the filter wall and channel therethrough. Instead, the air supplied was now "controlled", in the sense that it was focussed in close proximity to a small area of dirty wall--in this circumstance, the jet of air would tend to pass through that area and remove the dust on the outside surface of the filter medium.
While the basics of the system were now established, there were still some secondary problems to be solved.
More particularly, centering of the soiled filters in the apparatus was difficult to consistently and quickly carry out. The central axis of the filter had to substantially coincide with the axis of the nozzle assembly, otherwise the close-coupled nozzles were liable to rip into the filter wall when the latter was spun. As there are many sizes of filters, it was necessary that centering means be provided and that they be adjustable.
In early versions of the assembly, a plurality of upstanding lugs or pins in a circular pattern were provided on the filter gripping plates, to engage the outer vertical side surface of the filter at points spaced around its circumference. These lugs were individually moveable radially and could be tightened down to lock them in place in tight abutment against the filter end. However, it was always a guessing game as to whether the axis of the filter was properly centered.
This problem was overcome by providing an assembly in which the lugs are simultaneously moved radially at the same rate, so that their centre remains constant.
Another secondary problem was that the fine dust particles were very difficult to dislodge from the filter. It was eventually discovered that preliminary drying of the filter and its attached solids would successfully convert the fines to a condition in which they could relatively easily be dislodged.
Patent Prior Art
In a search of the prior art U.S. patents, three of interest were located. These are: U.S. Pat. No. 3,998,656 issued to Grotto; U.S. Pat. No. 2,591,198, issued to Ringe; and U.S. Pat. No. 3,958,296 issued to Fell.
Grotto is the most pertinent, in that he shows the combined actions of spinning, reverse air flow and external suction. However Grotto does not incorporate a close-coupled, localized air flow in his cleaning action.
Ringe shows a long, rotating vane feeding air to reverse flow it through a stationary filter. Ringe fails to incorporate longitudinally moving, localized air flow and simultaneous spinning of the filter.
Fell shows a central air supply shaft and radial nozzles. However he too fails to incorporate spinning.
SUMMARY OF THE INVENTION
In accordance with the invention, therefore, there is provided a cleaner system consisting of a method and apparatus and incorporating the simultaneously applied actions of:
spinning the filter at a controlled rate;
applying a localized, close-coupled jet of air to the inner surface of the spinning filter and moving one of the jet and the filter relative to the other longitudinally, so that substantially all of the filter wall is subjected to the concentrated reverse air flow; and
applying suction to the exterior of the filter, to draw off the dust-laden air.
In an apparatus aspect, the invention is a cleaner assembly for dry cleaning a generally tubular air filter having a pleated paper filter medium therein on which dust has collected, comprising: (a) means for spinning the filter about its longitudinal axis; (b) means for applying one or more localized, close-coupled jets of pressurized air generally radially to the inner surface of the spinning filter, to dislodge the dust attached to the exterior of the filter paper and immediately in the path of said jet; (c) means for supplying pressurized air to said means (b); (d) means for reciprocating one of the means (b) and the filter, relative to the other longitudinally, whereby substantially all of the filter wall may be subjected to reverse air flow; and (e) means for applying suction to the exterior of the spinning filter during air cleaning, to draw off dust-laden air.
In another aspect, the invention is a method for cleaning dust from the outer surface of the pleated paper filter medium of a generally tubular air filter comprising: (a) drying the filter with dry air until the dust is substantially dry; (b) spinning the dry filter about its longitudinal axis in a cabinet; (c) applying a localized, close-coupled air jet to the inside surface of the spinning filter to clean a small area of the filter wall directly in the path of the jet, and moving one of the jet and the filter longitudinally relative to the other, so that the jet is applied to all or at least a major part of the surface of the filter wall; and (d) simultaneously suctioning dusty air from the cabinet.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partly schematic perspective view of the cleaner assembly;
FIG. 2 is a partly schematic, plan sectional view of the cleaner assembly;
FIG. 3 is an end view showing part of the filter wall and a nozzle group;
FIG. 4 is a plan view showing the rear plate; and
FIG. 5 is a perspective partly sectional view showing the details of a plate assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The Cabinet
The cleaner assembly 1 comprises a horizontal cylindrical cabinet 2 having end walls 3, 4. The cabinet 2 forms an interior cleaning chamber 5. A door 6 provides access to the chamber 5, for insertion and removal of filters 7.
The Filter Gripping and Spinning Means
A pair of plate assemblies 8, 9 are mounted in the chamber 5, for gripping the filter 7 at its ends and spinning it. Each such assembly comprises a pair of locked-together, flat plates extending in a vertical plane. The two plate assemblies 8, 9 are coaxial.
The left plate assembly 8 is mounted on a horizontally extending, hollow shaft 10. This shaft 10 is rotatable, being supported by bearing 11, which is supported by the cabinet end wall 3. A drive sheave 12 is secured to the shaft 10. A variable speed, reversible motor 13 is provided to drive the sheave 12 through the belt 14. In summary, therefore, the left plate assembly 8 is adapted to be rotated in either direction at a controlled, variable speed.
The right plate assembly 9 is arranged for free-wheeling rotation on a horizontally extending, axially extendable, non-rotating double-acting cylinder 15. More particularly, the plates 9a, 9b of the assembly 9 are mounted on a hub 16 extending over the left end of cylinder 15. The hub 16 is supported for rotation by the bearings 17. The cylinder 15 extends outwardly to the right through the cabinet end wall 4. It is supported by the sleeve 18 and its piston 19 is pivotally secured to a stop 20. A hydraulic pressure tank 21, supplied by a pump (not shown), functions to supply fluid through a valve 21a to the cylinder 15 through one of the lines 22, 23 to move the plate assembly 9 to the left or right, as required.
In summary, the right plate assembly 9 is free to rotate and can be controllably moved toward or away from the left plate assembly 8, to vary the spacing between them, as required to accommodate the filter 7. When the valve 21a is turned off, the spacing is fixed, as the right plate assembly 9 cannot then be shifted in either direction.
The plate assemblies 8, 9 are arranged to quickly and accurately centralize the filter 7 and to restrain it against lateral displacement when it is being spun. More particularly, the plate assemblies 8, 9 each comprise front and rear plates 8a, 8b and 9a, 9b respectively. The front plates 8a and 9a are fixed to the shaft 10 and hub 16 respectively. The rear plates 8b and 9b are rotatably mounted on the shaft 10 and hub 16 respectively and can be turned manually. Each front plate 8a, 9a has three equidistant, identical, linear slots 24 arranged 120° apart and extending from a common concentric inner radius to an outer radius. Each rear plate 8b, 9b has three equidistant, identical, curved slots 25 arranged to run from the same concentric inner radius to the same outer radius, as is the case with the slots 24. The front plate slots 24 are of greater width than the rear plate slots 25, as indicated in FIG. 5. Pins 27, having bearings 27a, which are positioned in the slots 24, 25 and through the front plates 9a. Bolt and nut assemblies 29 are provided to lock each of the pairs of plates 8a, 8b and 9a, 9b together, thereby fixing the positions of the pins 27. More particularly, a bolt 29a extends rearwardly from each front plate 8a, 9a through a slot 50 formed in the rear plate. A wing nut 29b can be screwed down to lock the front and rear plates together.
In summary, the filter 7 can be inserted between the front plates 8a, 9a. The right front plate 9a can then be advanced to the left by acuating pump 21. When the filter 7 is firmly gripped between the front plates, the valve 21a is turned off. The rear plates 8b, 9b are then manually rotated to simultaneously move the pins 27 inwardly to abut the side wall of the filter 7, while simultaneously centering it. The bolt and nut assemblies 29 are then tightened to lock the pins 27 and the pair of plates. As a result, the pins 27 function to hold the filter 7 in a centralized position, coaxial with the plate assemblies 8, 9 during spinning.
The Nozzle Assembly
A horizontally extending, first air tube 31 extends concentrically through the drive shaft 10 and is slidable longitudinally back and forth in said shaft. The right end of the first air tube 31 is thus positioned within the central bore of a filter 7, when the latter is in place between the plate assemblies 8, 9.
A second air tube 32 is disposed parallel and coextensive with the first air tube 31. Said second air tube 32 extends through the cabinet end wall 3 at an elevation such that it lies close to the outer surface of the filter 7.
The two air tubes 31, 32 are secured at their left ends to a cross member 33. A double-acting hydraulic cylinder 34 is also secured to the cross member 33, for reciprocating the tubes 31, 32. A hydraulic pump 35 is provided to actuate the cylinder 34. The pump 35 is provided with suitable controls, not shown, to cause it to reciprocate the air tubes 31, 32 at a pre-determined frequency and rate.
A compressor 36 is provided to supply pressurized air to the first and second air tubes 31, 32.
Attached to the right end of each air tube 31, 32 is a radially extending tube 37 which terminates in a plurality of nozzles 38. The two groups of nozzles 38 are close coupled to the inner and outer surfaces of the filter paper 39. The three nozzles of each group are arranged angularly, so that their jets will impact closely adjacent to, but spaced apart, portions of the pleated filter paper 39--this arrangement results in some vibration of the paper, which assists in dislodgement of the dust.
The nozzles 38 can vary in size and configuration--we typically use a nozzle having a bar-type 3/32" outlet and supply 12 CFM of air to it at a pressure of about 40 psi (for small filters) to about 120 psi (for large filters).
In summary, the first or inner air tube 31 is adapted to be reciprocated back and forth along the length of the spinning filter 7. The nozzles 38 provide close-coupled, localized jets of air which are found to be effective to dislodge the dirt on the outer side of the filter paper 39.
The second or outer tube 32 is not as important as the first. However its jets of air do assist in vibrating the filter paper 39. Also, the outside jets will loosen dirt clinging to the outside surface of the filter paper. The inside jets then blow the loosened dirt free of the paper.
Suction
A suction fan 40 is connected through a duct 41 with the cabinet 2. Openings 42 are also provided in the cabinet 2.
The fan 40 functions to remove not only the air being injected through the nozzles 38, but also the flushing air entering through the cabinet openings 42. Typically we use a fan capable of removing about 3000 CFM.
Pre-Drying
The filter 7 should be dried with a warm, dry air flow until the attached dust particles are substantially moisture free, before being cleaned. We have found that, otherwise, the fine particles, which become dampened in use by the natural humidity in the air, will tend to cling tenaciously to the filter paper and to a significant extent are not dislodged during cleaning. Once dried, however, they will come off relatively easily during cleaning.
Operation
The dirty, dried filter 7 is placed between the planar plate assemblies 8, 9. The piston 19 of the cylinder 15 is extended by actuating the pump 21, to move the plate assembly 9 to the left, whereby the plate assemblies 8, 9 will firmly engage the ends of the filter 7. The rear plates 8b, 9b are then rotated manually, to cause the pins 27 to move inwardly to centralize and grip the filter 7 from the side. The bolt and nut assembly 29 and set screw 30 are tightened to fix the plate assemblies 8, 9. The motor 13 is then actuated, to spin the filter 7. The air compressor 36 is actuated to commence pumping pressurized air through the nozzles 38. At the same time, the suction fan 40 is actuated to draw dusty air from the cabinet 2. The pump is then actuated to reciprocate the air tubes 31, 32 and their nozzles 38 along the inner surface of the filter 7, to clean the latter.
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As a preliminary step, the dirty filter is dried to remove substantially all moisture from the dust on the filter. The filter is then spun in a closed cabinet. Simultaneously, a jet of pressurized air is reciprocated in close proximity along the inner surface of the filter. Also at the same time, suction is maintained on the cabinet, to remove dust-laden air and assist in the dislodging of the dust from the filter paper. By the combined actions of spinning, close-coupled reverse air jetting, and suction, the dust can substantially all be removed from the dirty filter.
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This is a continuation of U.S. application Ser. No. 895,061, filed Apr. 10, 1978, now abandoned, which in turn is a continuation-in-part of U.S. application Ser. No. 670,902, filed Mar. 26, 1976, now abandoned. Reference is also had to U.S. application Ser. No. 136,129, a divisional of said abandoned continuation-in-part application Ser. No. 895,061.
BACKGROUND OF THE INVENTION
The invention generally relates to pressure indicating devices of the type used for the measurement of body fluid pressures and more particularly to an indirect non-invasive automatic mean blood pressure reading device.
FIELD OF THE INVENTION
The pressures of fluids in the vessels of all living things are indications of many facts which are of great value to those engaged in medical, biological and related fields. In the case of humans, the pressure in the vascular system is measured for many reasons, including diagnosis in pathology, laboratory routine for certain ailments, ascertainment of the progress of therapy, etc. As an example, the determination of venous blood pressure is an essential element in the diagnosis of a patient suspected of cardiac disease. Normal human venous blood pressure ranges between 80-120 millimeters water, whereas elevations of venous blood pressure above that range are found in cases of congestive heart failure.
True mean arterial pressure is not the arithmetic average of the systolic and diastolic pressure. Mean pressure depends on the amplitude and contour of the arterial pressure wave. Thus for example, if a person has a systolic pressure of 100 and a diastolic pressure of 50, the mean pressure would not be 75 but would be closer to 63 because the pulsation of the blood does not spend much time at the high systolic point as it retreats quickly from this peak pressure so that most of the pulsation time is spent at a lower pressure near the diastolic pressure. Thus if a total arterial wave form is ascertained, or its mean, a better picture of the patient's condition is presented to the physician. The presentation of only the systolic and diastolic pressure to a physician does not enable the physician to make a truly accurate assessment of the patient's arterial wave form. All that is really indicated by the pressure is that when the heart contracts, for some variable period of time the pressure in the artery goes up to systolic pressure. Thus the physician cannot determine if the pressure is for a tenth of a second, only that a particular pressure has been reached for some unknown instant. However, as to the actual pressure that the capillaries are encountering, the fluctuations are all, or practically all damped out. Thus by knowing the mean pressure the physician is better able to determine the pressure head that is driving blood through the capillaries.
Oscillatory mean blood pressure measurement is discussed in the "The Meaning of the Point of Maximum Oscillations in Cuff Pressure in the Indirect Measurement of Blood Pressure" July-September 1969, the Cardiovascular Research Center Bulletin page 15.
Presently the only means of measuring mean arterial pressure is to monitor it with direct intra-arterial means. While doctors are presently taking indirect measurements of the systolic and diastolic pressures of patients there is currently no automatic way that indirect mean blood pressure measurement can be obtained.
DESCRIPTION OF THE PRIOR ART
The most common method of obtaining indirect arterial blood pressure has been to gradually apply constructive pressure about the limb of the patient until the flow of blood through a vessel has been arrested, as determined by listening to a stethoscope applied over the vessel at a point distal the point of constriction. Then upon gradual release of the constricted pressure, the beginning of the flow through the vessel can be heard and the constricted pressure is noted on a gauge reading in millimeters of mercury. This pressure is referred to as systolic pressure. The pressure is then further gradually released until the sounds of the flow again cease and the pressure is again noted, which pressure is referred to as diastolic pressure. The difference between the diastolic pressure and systolic pressure is termed pulse pressure. Previous constriction pressure has been derived from an inflatable cuff connected to a mercury column manometer or to an aneroid type gauge having a dial scale calibrated in millimeters of mercury. While this common device is satisfactory for measuring the diastolic-systolic pressure range for a discrete period of time, it has the obvious disadvantage of not being able to continuously monitor the patient's blood pressure.
Many other attempts have been made to devise indirect blood pressure gauges which are portable, of reasonable cost and yet provide the attending physician with an accurate determination of the patient's blood pressure. One such device employs telescopically related, spring loaded tubes, the tubes being biased in an extended position. By exerting axial pressure on the tubes against an artery until blood flow in that artery is cut off, and by monitoring the relative displacement of the tubes from the fully extended position required to produce such flow cut off, the systolic pressure is monitored. However, this means for monitoring the displacement of the tubes is often inconvenient or clumsy.
Another prior art device employs a pointer extending from an inner tube through a longitudinal slot in an outer tube, the outer tube having calibrated markings adjacent the slot. A disadvantage with this arrangement lies in the fact that the tubes, and hence the pointer, return to the original biased position upon removal of the instrument from the body, thereby requiring the operator to take a reading while exerting direct pressure. Such a technique has been found to be inconvenient.
One automatic method which is used to obtain pressure readings comprises an ultrasound transducer which emits an ultrasound beam toward the artery. If the artery is pulsating, meaning that the pressure in the cuff is less than systolic pressure, it reflects back some of the ultrasound at a different frequency indicating that the pressure in the cuff must be below systolic pressure. Thus by starting the pressure of the cuff far above systolic pressure and bleeding it down slowly, one starts in a condition where the reflected ultrasonic sound is not of a changed frequency, that is the artery is not pulsating and as the cuff pressure bleeds down further at a certain point the artery will begin to pulsate which is indicated by a changed frequency. In the arterial pulsation method an ultrasound pickup or a microphone or stethoscope can be used. In whatever device is used, either ultrasound transducer or microphone, an instrument is utilized external to the cuff thus requiring a wire connecting the cuff to electronic circuitry used to make the pressure measurements.
There are several disadvantages in the above-mentioned types of devices, one being that in the microphone and stethoscope devices the turbulence in the flow of blood is heard rather than a change or a direct reflection of pressure. What the device relies on is that the pressure in the cuff occludes the flow of blood. Thus on the slow release of pressure the resumption of flow is difficult to determine in low flow state such as shock. In fact, in shock, the ausculatory method where one puts the microphone or stethoscope over the artery and listens to the flow fails because there is not enough flow to make Korotkoff noises. The ultrasound method works better than the auscultatory method in shock because it detects the movement of the artery rather than a flow within the artery. The disadvantages in the ultrasound device however, are that the external sensors must be closely and carefully applied over the artery and require a coupling jelly which can be messy. Even if the transducers are positioned very carefully, there is a possibility that they might shift during a lengthy operation, resulting in erroneous readings or no readings at all. Furthermore, the transducers are in an exposed position and can be easily broken resulting in expensive replacement costs.
In addition, with the ultrasound equipment, if one wants to measure the blood pressure of a child, a different size transducer must be used from the transducer used to measure the blood pressure of an adult necessitating the change of the transducer besides the additional cost of purchasing the different size transducer.
Another indirect measuring device is shown in U.S. Pat. No. 3,903,872 which teaches a system for measuring systolic and diastolic pressure by using a blood pressure cuff with a transducer mounted on the outside of it. The cuff is linearly inflated from zero pressure and during inflation the device picks for diastolic pressure the cuff pressure at which the slope of the first derivative just before the onset of a beat was a negative maximum and chooses for systolic pressure a point of the cuff pressure at which the second derivative was maximum.
Another indirect measuring method measures oscillation in the cuff pressure. The method dates from the turn of the century but has not been widely utilized because of the problems associated with it. It should be noted that the indirect measurement of mean blood pressure in a horse has been taken with the use of an oscillometer and a physiograph. This indirect measurement is described in The Southwestern Veterinarian, Volume 23 Summer of 1970, number 4 pages 289-294 and appears to be the most pertinent reference known to applicant in relation to the present invention. In this publication the cuff pressure was recorded on the physiograph and the oscillations in cuff pressure were amplified and displayed by a rapid responding meter on an electronic oscillometer with the amplified oscillations being recorded on the physiograph along with the direct arterial pressures. This method of measuring mean pressure requires operator judgment as to when the oscillations are maximum, which is difficult to quickly and correctly ascertain.
SUMMARY OF THE INVENTION
The present invention relates to automatic indirect blood pressure reading apparatus that automatically and adaptively pumps up an arm cuff to a proper pressure by taking the previous cuff pressure measurement and adding approximately 60 mm of mercury to the old pressure before beginning measurement of the amplitude of the oscillations in the cuff.
This adaptive pump-up feature minimizes the period of time that blood flow is occluded in the arm by minimizing the amount of overpressure required to occlude.
Once the amplitude of the oscillations at the starting pressure are measured the cuff is deflated a pre-determined pressure increment to a lower pressure and the oscillations at this lower cuff pressure are then measured. It is required that the pressure oscillations satisfy a plurality of artifact detecting tests before a peak to peak oscillation measurement is accepted as valid. Should an artifact be detected, additional oscillations are measured until the oscillations are tested to be free of artifacts. When this integrity test is satisfied or some predetermined time interval is exceeded, the cuff is once again deflated a pressure increment. The apparatus continues in this fashion until maximum amplitude oscillations are obtained at the lowest cuff pressure which is indicative of the mean arterial pressure. If after several deflation cycles after the maximum oscillation is reached and no peak to peak oscillation value is found which is greater than the peak to peak value which was previously ascertained, the cuff pressure at which the oscillations were maximum is displayed as mean arterial pressure and the cuff is purged to allow the venous blood trapped in the arm to drain. A programmed wait cycle is then entered and the entire procedure is repeated at the end of the wait period.
The invention is an indirect and non-invasive automatic device that pumps a cuff up and measures the mean blood pressure value automatically as it automatically deflates in pressure increments without any operator intervention. Additionally, it can be made to display a number proportional to the magnitude of peripheral pulsation which can be useful in determining the amount of vasoconstriction.
Measurement of mean arterial pressure by means of incremental deflation, conditioned upon successfully passing a plurality of oscillation integrity tests, forms a novel aspect of this invention and a desirable structure to satisfactorily operate reliably without human intervention.
The invention is constructed with a pressure transducer, air-pump, deflate valve, and a plurality of linear and digital semiconductor integrated circuits positioned within a cabinet enclosure. A three digit, numerical display indicates mean arterial pressure and an accessory printer can be used to print a tape for a permanent record.
The above mentioned purposes and operation are more readily apparent when read in conjunction with the following detailed description of a preferred embodiment of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of the overall invention.
FIG. 2 is a timing diagram of the cyclic action taken by the invention when performing mean arterial pressure measurements automatically.
FIG. 3A is a timing diagram of the applied cuff pressure signal during measurement.
FIG. 3B is a timing diagram of the arterial pulse pressure signal during measurement.
FIG. 4A is a signal characteristic diagram showing a time sampled arterial pulsation signal;
FIG. 4B is a signal characteristic diagram showing the derivative of the signal of FIG. 4A;
FIG. 4C is a signal characteristic diagram of a sampled cuff pressure signal taken simultaneously with the signals of FIGS. 4A and 4B;
FIG. 5 is a schematic block diagram of the pressure measurement circuits shown in FIG. 1;
FIG. 6 discloses a block diagram of the peak to peak calculator with artifact rejection circuits shown in FIG. 5;
FIG. 7A discloses the circuit operation of the pressure derivative calculator of FIG. 6;
FIG. 7B discloses the circuit operation of the peak-to peak detector of FIG. 6;
FIG. 7C discloses the circuit operation of the averager of FIG. 6;
FIG. 7D discloses the circuit operation of the amplitude check of FIG. 6;
FIG. 7E discloses the circuit operation of the envelope check of FIG. 6;
FIG. 7F discloses the circuit operation of the slope check of FIG. 6;
FIG. 7G discloses the circuit operation of the period check of FIG. 6;
FIG. 7H discloses the circuit operation of the rise time check of FIG. 6;
FIG. 7I discloses the circuit operation of the cuff pressure check of FIG. 6;
FIG. 8 is a block diagram of the maximum peak-to-peak selector circuit operation of FIG. 5;
FIG. 9 is a schematic block diagram showing the adaptive pump-up circuit operation of FIG. 5;
FIG. 10 is a schematic block diagram of the autozero pressure circuit operation of FIG. 5; and
FIG. 11 is an electronic schematic showing implementation of a typical sub-system of the invention using standard commonly available linear and logic semiconductor circuit components.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The automatic mean arterial blood pressure measuring apparatus as shown in FIG. 1 basically consists of an inflatable cuff 2 wrapped around an arm 1, pump up and deflation means 7 and 9, and electronic pressure measurement apparatus 6, 10, 11, 13, 14, 16 and 17 with numeric display means 23. With the exception of the cuff all the component parts are housed within cabinet 300. Additional circuits are provided to alert attending personnel to abnormal pressure or operating conditions. Further patient safety is enhanced with a protective overpressure switch 8 which will cause cuff deflation should the pump fail to shut off in a normal, controlled manner. The novelty of this invention primarily resides within the pressure measurement circuits 11 combined with conditional, incremental cuff deflation by means of deflate valve 7.
In operation, cuff 2 is wrapped around arm 1 and is automatically inflated to a predetermined pressure via air-tube 4 by air-pump 9. A pressure sensing tube 5 is connected to cuff 2 at point 3 and is coupled to an electronic pressure transducer 6. This transducer outputs a voltage proportional to the air pressure of tube 5 which typically consists of a d.c. voltage with a small superimposed, variational component which is caused by the arterial blood pressure pulsations in arm 1.
The transducer 6 produces an output 12 which is routed to a multiplexer 16 and to a bandpass filter 13 which in turn is connected to a quasi-logarithmic amplifier and compressor 14, having an output signal 15 to multiplexer 16. Subsystems 13 and 14, namely the filter and amplifier are designed to reject the d.c. component of pressure signal 12 and yet amplify the blood pressure pulsations. The filter 13 passes those signals whose frequency components lie in a range from 1 to 10 Hz and strongly rejects other frequency components. Amplifier 14 magnifies low level signals from filter 13 and reduces the level of larger signals in a manner approximating that of a logarithmic curve. These components are not novel and are readily implemented by one skilled in the art. The cuff pressure signal 12 and pressure pulsation signal 15 will be further described in the discussion of FIG. 3.
The multiplexer 16 selects one of two pressure signals and inputs it into a sampling analog to digital convertor 17. Each sampled pressure point is represented by 8 binary bits which are routed via line 18 to pressure measurement circuits 11.
Circuits 11 employ a plurality of logic circuits to determine the minimum cuff pressure for which a maximum pulsation exists. This cuff pressure produces a signal output on connection 21 to display 23. Circuits 11 also transmit a deflate control signal 34 to valve 7 via OR gate 39, a multiplexer select signal 37 and a control signal 38 indicating to apparatus timer 10 that a mean arterial pressure measurement is complete. Also a power-on reset signal is transmitted from 20 to properly initiate logic states when power from supply 19 is first turned on. Detailed circuit operation of 11 will be described later.
As shown in FIG. 1, the MAPOUT signal 21 is also routed to comparators 27, 28 where the value is compared to the patient pre-determined acceptable pressure limits as stored in counter/registers 24, 25 and found within those limits. These limit values are set to desired values by switch 26 which causes the counters to up-count in steps of 5 mmHg. The stored limit value is displayed by switch 22 which connects the display to either the high or low limit registers. Should the measured means arterial pressure be below the predetermined low-limit, then comparator 28 activates alarm circuits 29 which generate an audible tone with sounder 30 and a visible flashing light with light 31.
Another output signal transmitted from the measurement circuits 11 is the MAPAV signal 38. This "mean-arterial-pressure-available" signal indicates to the system operation timer 10 that a measurement is complete, and that the timer may sequence to its next operation.
The operation timer 10 controls overall apparatus timing and is built with conventional, logic integrated semiconductor circuits. It is constructed with a crystal oscillator for precise timing and generates a plurality of timing control signals. Output pulse "i" is the basic sampling pulse and causes the A to D convertor 17 to take uniformly spaced samples. Output pulse "n" exists each time a new pressure increment interval is to be measured. The output pulse "n" is used by counting circuits in 11. Timing signals "Tm" generated from timer 10 are used by the apparatus to operate each separate operation and are shown in FIG. 2.
FIG. 2 is a diagram defining and summarizing each of four operation timing intervals. T1 is the premeasurement interval lasting about 7 sec. in which cuff 2 is stably deflated while display 23 continues to display the last MAP reading. Circuits within 11 are enabled to automatically zero the transducer 6 in case it has drifted. A detailed description of this circuit will be given later.
T2 is the interval in which the air-pump 9 inflates cuff 2 to a value which is adaptively set. The circuits and their operation for ascertaining this value will be described later. The pump-up time is typically 5 sec.
Apparatus alarms 29, 30 and 31 are also used to alert attending personnel to a possible failure. Should the sampling pulse "i" fail or MAPAV fail to give a reading after 3 minutes, then the failsafe alarm 32 will activate the alarms.
Operation timer 10, also has a control input from delay select switches 33 which are user selected for the desired interval between automatic measurements.
T3, in FIG. 2, is the interval during which the cuff 2 is incrementally deflated by valve 7 under control of the pressure measurement circuits 11. The exact duration of this interval is dependent upon the quality of the measured arterial heart pressure pulses. For example, if the patient should be moving his arm or the attending surgeon should be bumping against the cuff 2, then the artifact sensing circuits in 11 will reject the affected pulsations and cease further cuff deflations until apparently good pulsations are detected. Thus, the typical T3 interval is about 30 sec. but could extend to over a minute. Once circuit 11 has completed its measurement, the MAPAV signal 38 advances the timer to interval T4, and the new MAP is displayed on 23.
Interval T4 initiates cuff deflation and is followed by a period of apparatus inactivity. The cuff is emptied quickly to minimize patient discomfort. This idle interval is user settable with delay switches 33 for 0.5 to 8 minutes.
After interval T4, the apparatus repeats the described operations starting again with interval T1.
A detailed description of the measurement circuits 11 requires some definition of the basic pressure signals 12 and 15 (FIG. 1). Reference is now made to FIG. 3A and 3B which shows typical behavior of the cuff-pressure signal Pc(t) and the arterial pulsation signal p(t). During a measurement interval, the cuff pressure is incrementally decreased causing cuff pressure signal voltage 12 to proportionately decrease. Each step n(50) and its successor (n+1) (51) is about 5 mmHg less. The arterial pulsation signal 15 shows each pulse 52. This signal also shows the deflate transient 53 which is ignored by logic in circuit 11 as will be later described. Also shown is an artifact pulse 54 as might be caused by someone hitting the cuff. Note that additional pulses 55 are measured before another deflate is initiated. Arterial pulse pair 56 would be decided by measurement logic circuits 11 to be the maximum peak-to-peak arterial pulses according to circuits to be described. The corresponding cuff pressure 57 would be decided to be the MAP 59 and displayed on display 23. Once 5 deflations have been made beyond pulse point 56 or the cuff pressure 12 is less than 20 mmHg., the cuff is deflated. This is shown as point 58 on the cuff pressure signal.
The cuff and arterial pressure signals 12, 15, are digitized by convertor 17 and analyzed by circuits 11 (FIG. 1). Certain important digitized signal characteristics are shown in FIG. 4. The sampled arterial pulse waveform p(i), 60, has three important characteristics: 61 is its peak to peak value PP(n) where n is the number of the current deflate interval; 62 is the duration between pulse peaks, Tpp, expressed in number of clock samples, i; and 63 is the pulse rise time, Tr, also expressed as a number of clock samples. These characteristics are derived by circuits in 11 with aid of the signal derivative waveform 67. Details of this waveform (64, 65, 66) will be described later.
The corresponding typical sampled cuff pressure signal 68 is also shown, and is used by a plurality of circuits in 11 in a manner which will be described.
An expanded functional diagram of all the circuits contained within the pressure measurement subsystem 11 is shown in FIG. 5. Most of these circuit blocks will be further expanded to the detailed operating circuit level in FIGS. 6 through 9.
The pressure measurement circuits subsystem contains circuits which are operational during three timing intervals. During, T1, circuits 71 and 77 are activated to accomplish pressure transducer autozeroing. Basically, source select circuit 74 connects the A to D signal 18 to differencing amplifier 71 which transmits an output signal showing the difference between a previously stored auto-zero pressure (Pco) and the new presumed zero cuff pressure, Pc'(i) 84. Pco is adjusted by circuit 10 to force Pc(i) 68 to be zero value in a manner to be described later. This "new" Pco value is retained throughout the following T2, T3, and T4 intervals.
During interval T2, adaptive pump-up circuits 75 and 76 are activated and line 18 is connected to 71. If a previous MAP value exists in storage register 76, then circuits 75 enable the pump via line PMPON 36 to pump until the cuff pressure is 60 mmHg over this previous MAP value. The details of this will be discussed later on in the specification. When the desired cuff pressure has been achieved as determined by measuring the pressure on signal line 68, then the next timing cycle T3 is entered.
Signal T3 activates all of the measurement circuits during this interval consisting of circuits 70, 71, 72,73, 80, 81, 82 and 83. Heartbeat counter circuit 78 and cuff exhaust circuit 79 are ancillary safety circuits. The basic operation of these circuits is as follows.
Circuit 70 calculates the average peak to peak value of the first two arterial pulses in which no artifacts have been found. When the artifact checks are found to be "all-okay" then the control line 86 sends the average peak to peak pulse value to max. selector circuit 72. This circuit, in turn, causes circuit 73 to store the corresponding cuff pressure 68, if no previous stored peak-to-peak value was larger. On the first step, the prestored value is always zero. The "all-okay" signal also initiates a step deflate in cuff pressure via line 90 through gate 80 to step-deflate circuit 81. Circuit 81 deflates cuff 2 via OR gate 82 with control line 34 to a value 5 mmHg less pressure. The correct pressure is measured with line 68. The timer 83 generates a "start" pulse 88 one-half second after step deflate circuit 81 stops deflating as determined via line 87, which delay permits the cuff pressure transient 53 (FIG. 3B) to die away before starting another peak to peak measurement in 70. Start pulse 88 initiates another measurement cycle at the lower cuff pressure. This process continues until circuit 72 determines that it has successfully selected the minimum cuff pressure in 73 for which the average peak to peak pulsations 85 were a maximum. The details of this selection are discussed later in the specification. The Mean Arterial Pressure Available signal 38 is transmitted to the operation timer 10, which advances the timer to state T4. Simultaneously, the "MAP OUT" signal 21 is sent to the display.
Safety circuit 78 is a simple logic counter which determines if the number of heart pulses is in excess of fifteen during any pressure step which only happens if no pulse pair is free of artifacts. Its output signal, 89, initiates another cuff deflate via OR gate 80. By limiting the maximum time the cuff pressure may dwell on any one increment, undue patient discomfort is avoided.
The other safety circuit, 79, senses when cuff pressure has reached a useful minimum of 20 mmHg pressure and then initiates a full cuff deflate via gate 82.
An important and novel feature of this invention is the incorporation of sophisticated artifact detection circuits which are incorporated in pressure calculator 70 and shown in more detail in FIG. 6. The peak to peak calculator consists of circuits 100, 101, and 104. Peak to peak detector 100 determines the difference in value between the pulse maximum and base of the pulse wave form where the positive slope first exceeds a predetermined threshold as was shown in FIG. 4. This value is found for two successive arterial pulses and averaged by circuit 101. This average peak to peak value PP(n) is transmitted on line 85.
Artifact detection circuits 102, 103, 105, 106, 107 and 108 have their signal outputs AND'ed by gate 109. Only if all of these circuits are satisfied to be artifact free is the "All-okay" line 86 enabled on this subsystem output. Should an artifact be detected, inverter circuit 101 enables 0.5 second timer 111, which in turn causes all of the peak to peak calculator circuits to take additional pulse pair measurements without another cuff deflate. The 0.5 second delay gives time for the artifact transients to die out in the pneumatic system (2,4,5,6). The peak to peak calculator and artifact rejection circuits as described in FIG. 6 are seen to embody three principles vital to the reliable determination of non-invasive mean arterial blood pressure by automatic means: (1) determining peak to peak heart pulse value by analysis of its time derivative (described in detail in FIGS. 7A and 7B), (2) performing an average operation on a plurality of arterial pulses (described in detail in FIG. 7C), and (3) not permitting another incremental cuff deflation until at least a pair of heart pulses successfully pass a plurality of artifact sensing tests. These artifact sensing tests are described in detail in FIGS. 7D, E, F, G, H, and I.
The time derivative of the heart pulse signal p(i) is calculated to aid the peak to peak detector and artifact sensing circuits. The derivative calculator 104 is shown in detail in FIG. 7A. The detail shown in this figure and the remaining figures is sufficiently detailed so that they are readily implementable with commercially available logic circuits by one skilled in the art of electronics design. The derivative calculator 104 simply calculates the difference between the current pressure pulse value 6 and its previous value. The difference is transmitted as an output signal as the derivative 201.
This value is used by peak to peak detector 100 as shown in FIG. 7B. The first circuit 202, compares the derivative 201 to a predetermined value "L1". When L1 is exceeded in value by 201, then the previous pressure sample p(i-1) is stored as the minimum value of the heart pressure pulse "Pmin." The maximum value of the pulse is then determined as the p(i) value where the derivative is below a threshold value "L2" which is near zero. The corresponding p(i) value is stored as Pmax by circuit 203. Circuit 204 calculates the peak to peak value as Pmax-Pmin and outputs it as signal 205, PP(a). A second pulse is similarly found, PP(b), and transmitted on line 205 to averager circuit 101. The relative relationship of thresholds L1 and L2 are easily seen in FIG. 4B. The important and novel feature about this peak to peak calculation is that the minimum of the pulse is measured at the base of the heart systolic pulse rather than the diastolic transient minimum (see FIG. 4B, 206). This technique has been found to yield more accurate MAP measurements with less variance when compared to direct, invasive pressure measurements.
Averaging circuit 101 as shown in FIG. 7C sums PP(a) and PP(b) and divides them by 2. The previous value is stored in register 208 and the new average is transmitted as output signal 85. The averager circuit provides immunity to high frequency, low-level pressure artifacts.
The amplitude check circuit 102 is shown in FIG. 7D. The two adjacent peak to peak values PP(a), PP(b) output signals by the peak to peak detector 100 are compared in amplitude. If the second value differs by less than 20% of the first value, then the check is satisfactory and a binary signal output one is transmitted; otherwise the output is a binary zero. Circuit 102 is effective at detecting pressure artifacts such as attending personnel hitting the cuff accidentally in synchronism with the arterial pulses.
The purpose of this tolerance requirement is to reject those beats which are widely variable in amplitude from beat to beat such as could be caused by premature ventricular contractions. Not only does this eliminate the acceptance of variable data during heartbeat irregularities but it also is quite useful for reducing the influence of pulsation artifacts caused by subject motion or outside interference such as the physician bumping against the cuff as could occur in an operation.
Should two artifact pressure pulses be caused of approximately the same amplitude, such that it would satisfy the test of circuit 102, another amplitude test is made by circuit 103 shown in detail in FIG. 7E. This circuit compares the envelope, that is, the calculated average peak to peak heart pulses PP(n), 85, with the previously calculated value of the previous cuff pressure increment. As shown in FIG. 7E, the absolute difference of these average peak to peak values must be less than 30% of their sum to pass the test. As was shown earlier in FIG. 3, the heart pressure peak to peak amplitudes change gradually between cuff deflation increments and the comparator 216 and register 215 of circuit 103 will detect violations of this rule.
Another artifact detecting circuit 105, FIG. 7F, determines if the heart pulse derivative 201 ever exceeds a predetermined limit L6. Since the human heart cannot increase arterial pressure faster than some maximum, this circuit tests to see if that maximum is exceeded due to any artifact. If this test is passed, output signal 220 is a binary one. Otherwise it is a binary zero. The relative value of this limit L6 is shown in FIG. 4B.
An additional artifact detecting circuit 106 tests the heart pulse period (Tpp, 62 of FIG. 4A) of the heart pulse pair and compares it to the previously measured heart pulse pair period during the previous cuff deflation increment interval. This circuit is shown in FIG. 7G. Circuit 221 determines the sample number of the first heart pulse maximum and circuit 222 does the same on the second heart pulse. Subtractor 223 calculates the peak to peak time period Tpp as the difference of these sample clock values. Time period Tpp is then compared in circuit 225 with the previous Tpp 224 and if they are equal within a 15% tolerance, then the test is satisfied. This test is disabled during the first pressure deflation so that the "previous value" may be stored.
The time period checking circuit is a valuable artifact detecting circuit because erroneous arterial pulses which may pass the aforementioned amplitude tests are unlikely to also have precise periodicity.
This relative immunity to artifact is enhanced by several additional criteria which must be met by the pulsations before they are accepted by the device as being true cuff pressure pulsations due to heart action. One criteria is that the rate of pulse rise be within a certain range. That is, if the rate of rise of a pulsation is either too slow (as could be caused by a gentle pressure applied from without or within the cuff) or if the rate of rise is too fast (as could be caused by someone striking the cuff) the pulsation will be disregarded regardless of its amplitude.
Such an artifact sensing test is made by circuit 107 by confirming that the heart pulse rise time is within prespecified limits. FIG. 7H shows that this is accomplished by taking the time difference (expressed as number of sample periods) between the base of the heart pulse and its maximum (see 63 on FIG. 4B). Circuit 230 in FIG. 7H stores the sample clock value, i, where the pressure derivative 201 first exceeds a pre-determined threshold, L1. Circuit 231 similarly stores the "i" value when the derivative is below another threshold (near zero) L2. FIG. 4B shows the relative values of these two thresholds. Circuit 232 determines the rise-time as the difference of the output signal 230 and 231 and circuit 233 compares this rise time value to two predetermined values. If rise time 63 is between these two limits, circuit 233 produces a binary one output signal; otherwise, the output is a zero. This test is valuable at detecting any artifacts which may have periodic, consistent pressure amplitudes, thus passing aforementioned tests, but which are rapidly or very slowly applied to the cuff.
In order to insure that the mean cuff pressure has not varied significantly during these tests at any given deflation increment, a continuous check is made by circuit 108 and is shown in detail in FIG. 7I. The cuff pressure signal 68 is compared against stored ideal value in counter 240 by subtraction circuit 241 and checks to see that the absolute difference is less than 2 mmHg in circuit 242. If the pressure difference is less than 2 mmHg, then output signal 245 is a binary one; otherwise, it is a zero. When a new cuff deflation increment is requested by "START" signal 88, then the pressure value in counter 240 is decreased by 5 units, preparing circuit 108 for operation at the new cuff pressure. During the pump-up interval, control signal T2 (244) presets register 240 to a value determined by the adaptive pump-up circuit 75.
FIG. 9 shows the adaptive pump-up circuit in detail as was previously described in FIG. 5. Timing signal T2 activates circuit 250 and sets output latch 254 to a binary one on line 36, which causes the air pump to turn on. If no previous mean arterial pressure measurement has been made (therefore MAP (j-1)=0), then comparator 251 is activated which stops the pump when the cuff pressure 68 has reached 160 mmHg. It does this by outputting a binary one via OR gate 253 to reset the input of latch 254 causing output 36 to be a binary zero. However, should a non-zero, previous MAP exist, then circuit 250 activates comparator 252 which permits the pump to remain on until the cuff pressure 68 exceeds the previous MAP by 60 mmHg, at which time the circuit outputs a binary one via OR gate 253 to reset latch 254 causing the pump to turn off via line 36. This adaptive pump-up circuit provides a plurality of features not found on blood pressure instruments heretofore: (a) patient discomfort is minimized since pressure is not pumped any higher than necessary, (b) the time to deflate is reduced since fewer deflation increments are required reducing patient discomfort; and (c) this circuit alleviates the need for an operator control to set maximum pump-up pressure. During an operation, a patient's blood pressure may change drastically and this circuit will automatically increase or decrease maximum pressure as required.
Since mean pressure is determined by this device by finding the lowest cuff pressure at which the peak to peak oscillations in cuff pressure are maximum it is necessary to measure the amplitude of pulsation at several lower cuff pressures after the supposed maximum oscillation occurs to insure that the higher cuff pressure maximum is the true maximum and not an early false maximum.
The maximum peak to peak selection logic circuits described earlier with FIG. 5 is shown in more detail in FIG. 8. This is a common circuit for saving the maximum of a sequence of numbers presented to it with the addition of a count to five timer to terminate the operation five cuff deflation increments after a maximum has been found. In initial operation the register 262 is set to zero. When signal 86 is a binary one (T3=1 during measurement mode), then comparator 260 compares the value in register 262 with the input average peak to peak value 85. If the input signal value is larger, then comparator output signal 265 enables AND gate 261 to input this new higher value into 262. Signal 265 also resets counter 263 to a value of zero. With each new average peak to peak value input signal, counter 263 is upcounted by clock pulse "n". Should no new maximums be found, after five successive values have been tested to the contents of 262, then it is assumed that register 262 contains the last maximum arterial average pulsation. Gate 264 senses that the count is five in 263 and transmits a binary one output signal on MAPAV signal line 38. In this regard it is important to recall that the STORE signal line 265 has caused the corresponding cuff pressure to be stored in register 73 (FIG. 5).
A problem in any electronic pressure sensing means utilizing a pressure transducer is that the zero point of the transducer changes with temperature. This could mean that with no pressure in the cuff, the pressure transducer would have a certain output, which would be different for different temperatures. The problem is that to set the zero point one must specify at what temperature the transducer is. Thus, when the device has warmed up, the zero point is set for zero pressure in the cuff with the transducer having an output corresponding to zero pressure. When the device is first turned on the zero point may be considerably different, (roughly 15 to 20 mm of mercury) that at a later time when the device warms up.
In order to overcome this variability of zero point with varying temperature the present device has an automatic zeroing function which works in the following manner.
The auto-zero pressure circuit 77, shown in detail in FIG. 10 permits long term zero drifts of the pressure transducer to be effectively cancelled out, thus assuring apparatus integrity without additional operator adjustments. This circuit is activated during the pre-measurement interval by timing signal T1 which activates the two second timer 271 and comparator 270. Circuit 270 outputs a binary one on line 275 if the pressure derivative 201 does not vary by more than one least significant digit of the zero digital value during the two seconds that timer 271 activate the circuit. The activation signal on line 275 causes cuff pressure value 60 input signal to be transmitted to register 273. This value is later transmitted by an output signal on line 274 to substractor 71 of FIG. 5. Comparator 270 and timer 271 insure that the deflated cuff is not being moved or otherwise disturbed, thus invalidating the true zero value.
As noted above, every time the apparatus measures the peak to peak value it also measures the pressure which existed in the cuff at that time. The apparatus measures first the peak to peak value of the oscillation and then it switches internally and measures the value of the pressure in the cuff itself which is the absolute value of the pressure such as 98, 100 or 150 millimeters of mercury.
The cuff is emptied at the end of 5 cycles after it completely measures the average maximum peak to peak oscillation. The cuff is emptied quickly once the mean blood pressure has been determined since discomfort to the patient would occur if the pressure were slowly decreased. The rationale for continuing the determination several cycles after the maximum peak to peak value is obtained is to be sure that the maximum obtained wasn't a premature maximum.
When first used, the apparatus initially pumps up the pressure in the cuff to approximately 160 millimeters of mercury. However, on succeeding determinations the cuff is inflated approximately 60 mm Hg over the previously determined mean pressure. Thus, if the mean pressure is 80, the cuff would be inflated to 140 mm Hg the next time.
Thus the automatic apparatus pumps up the cuff each time to the proper pressure and measures the mean arterial pressure without a transducer or other mechanism external to the cabinet. This construction makes the apparatus very rugged and easy to make.
This construction allows the operator to more accurately measure indirect blood pressure, because the operator is not constrained by the time it takes to inflate and deflate the cuff. The cuff is deflated on the basis of how good the data is. Therefore, the apparatus can hold at one particular pressure until acceptable pulsation data is obtained whereas on a constantly deflating machine, it is possible to obtain an incorrect or an inaccurate reading at a particular deflation due to an irregularity which is kept as a valid value by the machine.
In essence what the apparatus does is that it is looking for two (or three) successive peaks which are very close togather in peak to peak value and which additionally do not have too fast or too slow a rise time or which do not have too long a duration. That is, the pulse fluctuation has to take place in the proper amount of time and must perform in the same manner as a real arterial pulse. Even if the pulses were the right size, for example, two pulsations occurred which were the right size, very close together but which went up very slowly and came down very slowly, the apparatus would reject the pulsations and say that these pulsations were not arterial pulses (i.e. perhaps someone must have bumped the cuff twice and it was bumped the same way both times, but it wasn't bumped like an arterial heartbeat). So the apparatus not only can reject pulses when their peak to peak value is of a non-acceptable tolerance, it can reject pulses through their shape i.e. how fast or how slow they reach their peak. The apparatus can only make all of these decisions by being able to hold at each pressure for a variable length of time until it gets good data. The time of holding however, does not extend beyond 14 to 16 heartbeats, or a predetermined amount of time in which case the fail safe timer 32 sounds the alarm 29-31.
The circuits described are all readily implemented with commercially available electronic components as previously mentioned and FIG. 11 shows a portion of the circuitry, functionally described in FIG. 1, in detail with integrated circuit type numbers shown which are familiar to those skilled in the art.
In an additional embodiment, instead of storing the pressure readings internally a small accessory printer (not shown) can be plugged into the rear of the cabinet and each pressure as it is determined by the device will be digitally printed on a paper tape much like an adding machine prints numbers on a paper tape. In this way a hard copy record of the entire blood pressure history of the patient can be obtained without operator intervention or effort. This hard copy record recorded by the device itself is useful in research and for later review.
While the preferred embodiment of the invention has been disclosed, it is understood that the invention is not limited to such an embodiment since it may be otherwise embodied in the scope of the appended claims.
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An apparatus for producing information indicative of the mean blood pressure of a living creature through indirect measurement comprising an inflatable cuff, a pump connected to the cuff, a deflating valve connected to the cuff, measuring apparatus connected to the cuff adapted to measure cuff pressure and pressure oscillations occurring in the cuff caused by the heartbeat of the living creature and control apparatus connected to the pressure measuring apparatus, pump and deflating valve. Deflation of the cuff occurs in pressure increments, with processing being done at each given decrement to evaluate plural successive pulsations for purposes of artifact rejection and identification of a true pulsation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a multi-beam optical system, and more particularly, it relates to a multi-beam optical system for use in an optical system of an image formation such as a multi-color copying machine, color laser printer, or the like.
2. Description of the Related Art
A multi-beam optical system for use on an optical system of an image formation apparatus such as a multi-color copying machine, color laser printer, or the like forms images of plural colors by irradiating respective light beams emitted from plural light sources onto different locations of a beam receiving surface. In accordance with difference in the characteristics of the light beams, it can compose those light beams in the middle portion of optical paths of those light beams and can scan the composed light beams by one scanning means and then separate the scanned light beams according to the differences of the characteristics of those light beams.
Generally in such a multi-beam optical system as mentioned above, there is used a semiconductor laser element as the light source, accordingly, the light beam becomes a laser light. In addition, there are many cases where a polygon mirror is used as the scanning means and a photosensitive drum as the beam receiving surface, respectively.
Now will be described below an example of details of such a conventional multi-beam optical system as mentioned above.
FIG. 1 is a schematic side elevation to illustrate construction of the conventional two-beam optical system.
This two-beam optical system is provided with two semiconductor laser elements 61 and 62 each of which outputs a laser light which is modulated based on the image data obtained by an image reader (not shown), a composing mirror 63, a polygon mirror 65, a lens 69, a photosensitive drum 71, reflecting mirrors 67a, 67b and 67c, a separating mirror 68, and the like.
Each of the semiconductor laser elements 61 and 62 emit a laser light of a different wavelength from each other. In the example of the conventional system, the semiconductor laser element 61 emits a laser light 13a of 810 nm wavelength and the semiconductor laser element 62 emits a laser light 13b of 750 nm of wave-length, respectively. There are arranged, both a semiconductor laser element 61 behind the composing mirror 63 on a straight line connecting the composing mirror 63 and the polygon mirror 65, and the semiconductor laser element 62 in an offset position in front of the composing mirror 63.
The composing mirror 63 consists of a dichroic mirror which transmits a laser light of 780 nm or more wavelength and reflects a laser light of less than 780 nm of wavelength, for example. Accordingly, the laser light 13a emitted from the semiconductor laser element 61 penetrates through the composing mirror 63 and travels toward the polygon mirror 65, and the laser light 13b emitted from the semiconductor laser element 62 is reflected by the composing mirror 63 and travels toward the polygon mirror 65. As a result, both laser light 13a and 13b are composed as one composite laser light 13c and the composite laser light 13c is made to be incident on the polygon mirror 65 from the composing mirror 63.
The composite laser light 13c is deflected by the rotating polygon mirror 65, penetrates through the lens 69 and is reflected by the reflecting mirror 67a, reaching the separating mirror 68.
The separating mirror 68 has the same characterisitic as the above-mentioned composing mirror 63, and it transmits the laser light 13a emitted from the semiconductor laser element 61 out of the composite laser light 13c and reflects the laser light 13b emitted from the semiconductor laser element 62. As a result, the laser light 13a penetrates through the separating mirror 68 and travels a straight optical path, and the laser light 13b is reflected by the separating mirror 68 and travels another optical path different from that of the laser light 13a.
As can be seen from the above description, both of the laser lights 13a and 13b being separated from the composite laser light 13c by the separating mirror 68 travel their respective optical paths and reach different locations on the photosensitive drum 71 which is the beam receiving surface. The laser light 13a is reflected by the reflecting mirror 67b disposed on its optical path and reaches the photosensitive drum 71. On the other hand, the laser light 13b is reflected by the reflecting mirror 67c disposed on its optical path and reaches the photosensitive drum 71.
Both of the laser lights 13a and 13b form electrostatic latent images on the photosensitive drum 71. At this time, in the case where the electrostatic latent image formed by the laser light 13a is developed with a black developer and the electrostatic latent image formed by the laser light 13b is developed with a color developer, such as a red developer, respectively, there can be obtained a multi-color (two colors in this case) hard copy.
Meanwhile, the polygon mirror 65 deflects the composite laser light 13c so that the composite laser light 13c can form a straight scanning line in a direction parallel to the axial direction of the photosensitive drum 71. However, a laser light which penetrates through the lens 69 generally forms an arcing scanning line because of the characteristic and distortion of the lens.
FIG. 2 is a schematic view to illustrate configurations of scanning lines La and Lb to be formed on the photosensitive drum 71 by both laser lights 13a and 13b, respectively.
Assuming that there is formed an upwardly convex arcing scanning line at point that a laser light penetrates through the lens 69, for example, the laser light 13a which was reflected a total of twice by the reflecting mirrors 67a and 67b, than the upwardly convex arcing scanning line La (shown by the broken line in FIG. 2) is formed on the photosensitive drum 71. On the other hand, the laser light 13b which was reflected a total of three times by the reflecting mirror 67a, the separating mirror 68 and the reflecting mirror 67c forms the downwardly convex arcing scanning line Lb (shown by the solid line in FIG. 2) on the photosenstive drum 71. As a result, two scanning lines La and Lb formed on the photosenitive drum 71 by the laser lights lights 13a and 13b, respectively are not a parallel relationship with each other.
In the case where an image of a black line and an image of a red line in a parallel relationship with each other are formed in a multi-color, there will be formed the image of a black line by such an upwardly convex scanning line La of the laser light 13a as shown by the broke line in FIG. 2 and the image of a red line by such a downwardly convex scanning line Lb of the laser light 13b as shown by the solid line in FIG. 2. As a result, there is a difference between a distance in the central portion of the black line image and red line image and a distance in both end portions of these images, and in an extreme case, there is formed images of both the black and red lines being crossed.
As may be clear from the above description, it may be hard to reproduce good images by the conventional multi-beam optical system.
SUMMARY OF THE INVENTION
The foregoing inconvenience is overcome in accordance with the present invention, and the primary object of the invention is to provide a multi-beam optical system capable of keeping a parallel relation between scanning lines of a plurality of light beams.
The multi-beam optical system of the present invention is provided with reflecting mirrors and separating mirrors on optical paths of light beams so that difference of the numbers of reflections of the scanned light beams while they penetrate through the lens and reach the beam receiving surface can be equally to each other or equal to an even number.
In the multi-beam optical system of the present invention, the difference of the number of reflections of the scanned light beams becomes an even number and the scanning lines are distorted in the same direction by the lens, and then it is not liable to lose a parallel relation between the line images.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevation to illustrate construction of the conventional two-beam optical system;
FIG. 2 is a schematic view to illustrate configurations of scanning lines being formed on a photosensitive drum by two laser lights of FIG. 2;
FIG. 3 is a schematic side elevation to illustrate one example of construction of a two beam optical system of the first preferred embodiment of the present invention;
FIG. 4 is a schematic view to illustrate configurations of scanning lines being formed on a photosensitive drum by two laser lights of FIG. 3;
FIG. 5 is a schematic side elevation to illustrate one example of construction of the two-beam optical system of the second preferred embodiment of the present invention;
FIG. 6 is a schematic view to illustrate configurations of scanning lines being formed on a photosensitive drum by two laser lights of FIG. 5;
FIG. 7 is a schematic side elevation to illustrate one example of construction of a three-beam optical system of the third embodiment of the invention;
FIG. 8 is a schematic view to illustrate configurations of scanning lines being formed on a photosensitive drum by three laser lights of FIG. 7;
FIG. 9 is schematic side elevation to illustrate one example of construction of the two-beam optical system of the fourth embodiment of the invention; and
FIG. 10 is a schematic view to illustrate configurations of scanning lines being formed on a photosensitive drum by two laser lights of FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now will be described below preferred embodiments of the present invention with reference to the accompanying drawings.
FIG. 3 is a schematic side elevation view to illustrate one example of a construction of the two-beam optical system of the first embodiment of the invention.
This two-beam optical system is provided with two semiconductor laser elements 61 and 62 each of which outputs a laser light being modulated based on the image data obtained by an image reader (not shown), a composing mirror 63, a polygon mirror 65, a lens 69, a photosensitive drum 71, reflecting mirrors 67a, 67b1, 67b2 and 67c, a separating mirror 68, and the like.
Each of the semiconductor laser elements 61 and 62 emit a laser light of a different wavelength from each other. In the embodiment of the invention, the semiconductor laser element 61 emits a laser light 13a of 810 nm wavelengths and the semiconductor laser element 62 emits a laser light 13b of 750 nm wavelength, respectively, for example. The semiconductor laser element 61 is arranged behind the composing mirror 63 on a straight line connecting the composing mirror 63 and the polygon mirror 65, and the semiconductor laser element 62 is positioned in an offset position in front of the composing mirror 63.
The composing mirror 63 consists of a dichroic mirror which transmits a laser light of 780 nm or more of wavelength and reflects a laser light of less than 780 nm wavelength for example. Accordingly, the laser light 13a emitted from the semiconductor laser element 61 penetrates through the composing mirror 63 and travels toward the polygon mirror 65, and the laser light 13b emitted from the semiconductor laser element 62 is reflected by the composing mirror 63 and travels toward the polygon mirror 65. As a result, both of the laser lights 13a and 13b are composed as one composite laser light 13c and the composite laser light 13c is made to be incident on the polygon mirror 65 from the composing mirror 63.
The composite laser light 13c is deflected by the rotating polygon mirror 65, penetrates through the lens 69 and is reflected by the reflecting mirror 67a, reaching the separating mirror 68.
The separating mirror 68 has the same characteristic as the above-mentioned composing mirror 63, and it transmits the laser light 13a emitted from the semiconductor laser element 61 out of the composite laser light 13c and reflects the laser light 13b emitted from the semiconductor laser element 62. As a result, the laser light 13a penetrates through the separating mirror 68 and travels a straight optical path, and the laser light 13b is reflected by the separating mirror 68 and travels another optical path different from that of the laser light 13a.
As can be seen from the above description, both of the laser lights 13a and 13b are separated from the composite laser light 13c by the separating mirror 68 as they travel their respective optical paths and reach different locations on the photosensitive drum 71. The laser light 13a is reflected by the reflecting mirror 67b2 disposed on its optical path, reaches and finally is reflected again by the reflecting mirror 67b1, and reaches the photosensitive drum 71. On the other hand, the laser light 13b is reflected by the reflecting mirror 67c disposed on its optical path and reaches the photosensitive drum 71.
Both of the laser lights 13a and 13b form electrostatic latent images on the photosensitive drum 71. At this time, in the case where the electrostatic latent image formed by the laser light 13a is developed with a black developer and the electrostatic latent image formed by the laser light 13b is developed with a color developer, such as a red developer, respectively, there can be obtained a multi-color (two colors in this case) hard copy.
Meanwhile, the polygon mirror 65 deflects the composite laser light 13c so that the composite laser light 13c can form a straight scanning line in a direction parallel to the axial direction of the photosensitive drum 71. However, a laser light which penetrates through the lens 69 generally forms an arcing scanning line because of the characteristic distortion of the lens.
FIG. 4 is a schematic view to illustrate configurations of scanning lines La and Lb to be formed on the photosensitive drum 71 by both laser lights 13a and 13b, respectively.
Assuming that there is formed an upwardly convex arcing scanning line at point that a laser light penetrates through the lens 69, for example, the laser light 13a which was reflected a total of three times by the reflecting mirrors 67a, 67b2 and 67b1, form the downwardly convex arcing scanning line La (shown by the broken line in FIG. 4) on the photosensitive drum 71. On the other hand, the laser light 13b which was reflected a total of three times by the reflecting mirror 67a, the separating mirror 68 and the reflecting mirror 67c forms the downwardly convex arcing scanning line Lb (shown by the solid line in FIG. 4) on the photosensitive drum 71. As a result, the two scanning lines La and Lb formed on the photosensitive drum 71 by the laser lights 13a and 13b, respectively are in parallel relationship with each other.
Where an image of a black line and an image of a red line, in a parallel relationship with each other, are formed in a multi-color image, the image of the black line is a downwardly convex scanning line La of the laser light 13a as shown by the broke line in FIG. 4 and the image of the red line is a downwardly convex scanning line Lb of the laser light 13b as shown by the solid line in FIG. 4. As a result, the images of the both lines are not crossed, and the reproduction images are faithful to the originals are obtained as a hard copy.
As mentioned above, in the first embodiment of the present invention, the laser light 13a is reflected a total of three times by the reflecting mirrors 67a, 67b2 and 67b1 on its optical path after it penetrated through the lens 69 and reaches the photosensitive drum 71. On the other hand, the laser light 13b is reflected a total of three times by the reflecting mirror 67a, separating mirror 68 and reflecting mirror 67c on its optical path after it penetrated through the lens 69 and reaches the photosensitive drum 71. Accordingly, the numbers of reflections between the both laser lights 13a and 13b are the same and their difference is 0.
Now will be described below a second embodiment of the invention.
FIG. 5 is a schematic side elevation view to illustrate one example of a construction of the two-beam optical system of the second embodiment of the invention.
Incidentally, in the second embodiment of the invention of FIG. 5, those elements numbered identically with the first embodiment of FIG. 3 perform the same or similar functions, and their explanation will be omitted here.
The only difference of the second embodiment from the first embodiment is optical paths of the laser lights 13a and 13b after those lights 13a and 13b have penetrated through the lens 69. In other words, the composite laser light 13c which penetrated through the lens 69 reaches the separating mirror 68 first. As in the case of the first embodiment, the separating mirror 68 separates the laser lights 13a and 13b from the composite laser light 13c by transmitting the laser light 13a and by reflecting the laser light 13b out of the composite laser light 13c, respectively.
After penetrating through the separating mirror 68, an optical path of the laser light 13a separated from the composite laser light 13c by the separating mirror 68 is reflected by the reflecting mirror 67b3 disposed on the optical path and then reaches and is reflected again by the reflecting mirror 67b4, before reaching the photosensitive drum 71. On the other hand, after being reflected by the separating mirror 68, an optical path of the laser light 13b separated from the composite laser light 13c by the separating mirror 68 is reflected by the reflecting mirror 67c disposed on the optical path and reaches the photosensitive drum 71.
FIG. 6 is a schematic view to illustrate configurations of scanning lines La and Lb to be formed on the photosensitive drum 71 by the laser lights 13a and 13b, respectively.
Assuming that there is formed an upwardly convex arcing scanning line at point that a laser light penetrates through the lens 69, for example, the laser light 13a which was reflected a total of twice by the reflecting mirrors 67b3 and 67b4, forms the upwardly convex arcing scanning line La (shown by the broken line in FIG. 6) on the photosensitive drum 71. On the other hand, the laser light 13b which was reflected a total of twice by the separating mirror 68 and the reflecting mirror 67c forms the upwardly convex arcing scanning line Lb (shown by the solid line in FIG. 6) on the photosensitive drum 71. As a result, two scanning lines La and Lb formed on the photosensitive drum 71 by the laser lights 13a and 13b, respectively are in parallel relationship with each other.
Where an image of a black line and an image of a red line in a parallel relationship with each other are formed in a multi-color image, there are formed the image of black upwardly convex scanning line La of the laser light 13a as shown by the broke line in FIG. 6 and the image of a red upwardly convex scanning line Lb of the laser light 13b as shown by the solid line in FIG. 6. As a result, the images of both lines are not crossed, and reproduction images faithful to the originals are obtained as a hard copy.
As mentioned above, in the second embodiment of the present invention, the laser light 13a is reflected a total of twice by the reflecting mirrors 67b3 and 67b4 on its optical path after it penetrated through the lens 69 and reaches the photosensitive drum 71. On the other hand, the laser light 13b is reflected a total of twice by the separating mirror 68 and the reflecting mirror 67c on its optical path after it penetrated through the lens 69 and reaches the photosensitive drum 71. Accordingly, the numbers of reflections between the both laser lights 13a and 13b are the same and their difference is 0.
Now will be described below a third embodiment of the invention.
FIG. 7 is a schematic side elevation to illustrate one example of a construction of the three-beam optical system of the third embodiment of the invention.
Incidentally, in the third embodiment of the invention of FIG. 7, those elements numbered identically with the second embodiment of FIG. 5 perform the same or similar functions, and their explanation will be omitted here.
Portions of the third embodiment of the invention which are different from the second embodiment are three pieces of semiconductor laser elements 61, 62 and 62' which emit the laser lights 13a, 13b and 13d, respectively. The semiconductor laser element 61 is arranged behind the composing mirror 63 on a straight line connecting the polygon mirror 65 and the composing mirror 63. Another composing mirror 63' is arranged in the middle of the straight line connecting the polygon mirror 65 and the composing mirror 63, and the semiconductor laser element 62' is offset and arranged at the side of the polygon mirror 65 of the composing mirror 63'. The semiconductor laser element 62 is offset and arranged at the side of the polygon mirror 65 of the composing mirror 63.
For example, the semiconductor laser element 61 emits the laser light 13a of 810 nm wavelength, the semiconductor laser element 62 emits the laser light 13b of 780 nm wavelength, and the semiconductor laser element 62' emits the laser light 13d of 750 nm wavelength, respectively.
The composing mirror 63 consists of a dichroic mirror which transmits a laser light of 795 nm or more of wavelength and reflects a laser light of less than 795 nm of wavelength. Another composing mirror 63' consists of a dichroic mirror which transmits a laser light of 765 nm or more of wavelength and reflects a laser light of less than 765 nm.
Accordingly, the laser light 13a emitted from the semiconductor laser element 61 penetrates through the composing mirror 63 and travels toward the composing mirror 63', and the laser light 13b emitted from the semiconductor laser element 62 is reflected by the composing mirror 63 and travels toward the composing mirror 63'. As a result, the laser lights 13a and 13d are composed as one composite laser light 13c' and are made to be incident on the composing mirror 63'. The composite laser light 13c' penetrates through the composing mirror 63' and travels toward the polygon mirror 65, and the laser light 13d emitted from the semiconductor laser element 62' is reflected by the composing mirror 63' and travels toward the polygon mirror 65. Then both laser lights 13c' and 13d are composed as one composite laser light 13c and it is made to be incident on the polygon mirror 65.
The composite laser light 13c which has been scanned by the polygon mirror 65 and has penetrated through the lens 69 reaches the separating mirror 68' first. The separating mirror 68' has the same characteristic as that of the composing mirror 63', and it transmits the laser lights 13a and 13b out of the composite laser light 13c and reflects the laser light 13d. As a result, the laser light 13c' composed of the laser lights 13a and 13b penetrates through the separating mirror 68' and travels its straight optical path, and the laser light 13d is reflected by the separating mirror 68' and travels another optical path different from the composite laser light 13c'.
As mentioned above, the laser light 13d separated from the composite laser light 13c by the separating mirror 68' is reflected by the reflecting mirror 67d disposed on its optical path and reaches the photosensitive drum 71. On the other hand, the composite laser light 13c' which has penetrated through the separating mirror 68' reaches the separating mirror 68 disposed on its optical path.
The separating mirror 68 has the same characteristic as that of the composing mirror 63, and it transmits the laser light 13a out of the composite laser light 13c' and reflects the laser light 13b, separating the laser lights 13a and 13b from the composite laser light 13c'.
After penetrating through the separating mirror 68, an optical path of the laser light 13a separated from the composite laser light 13c' by the separating mirror 68 is reflected by the reflecting mirror 67b3 being disposed on the optical path and then reaches and is reflected again by the reflecting mirror 67b4, before reaching the photosensitive drum 71. On the other hand, after being reflected by the separating mirror 68, an optical path of the laser light 13b separated from the composite laser light 13c' by the separating mirror 68 is reflected by the reflecting mirror 67c disposed on the optical path and before it reaches the photosensitive drum 71.
FIG. 8 is a schematic view to illustrate configurations of scanning lines La, Lb and Ld to be formed on the photo-sensitive drum 71 by the both laser lights 13a, 13b and 13d, respectively.
Assuming that there is formed an upwardly convex arcing scanning line at point that a laser light penetrates through the lens 69, for example, the laser light 13a which was reflected a total of twice by the reflecting mirrors 67b3 and 67b4, forms the upwardly convex arcing scanning line La (shown by the broken line in FIG. 8) on the photosensitive drum 71. On the other hand, the laser light 13b which was reflected a total of twice by the separating mirror 68 and the reflecting mirror 67c forms the upwardly convex arcing scanning line Lb (shown by the solid line in FIG. 8) on the photosensitive drum 71. Further, the laser light 13d which was reflected a total of twice by the separating mirror 68' and reflecting mirror 67d forms the upwardly convex arcing scanning line Ld (shown by the alternate long and short dash line in FIG. 8) on the photosensitive drum 71. As a result, three scanning lines La, Lb and Ld formed on the photosensitive drum 71 by the laser lights 13a, 13b and 13d, respectively are in parallel relationship with each other.
Where an image of a black line, an image of a red line and a image of a blue line in a parallel relationship with each other are formed into a multi-color image, there are formed the image of a black line by an upwardly convex scanning line La of the laser light 13a as shown by the broke line in FIG. 8, the image of a red line by a upwardly convex scanning line Lb of the laser light 13b as shown by the solid line in FIG. 8, and the image of a blue line by a upwardly convex scanning line Ld of the laser light 13d as shown by the alternate long and short dash line in FIG. 8. As a result, there the images of the three lines are not crossed, and reproduction images faithful to the originals are obtained as a hard copy.
As mentioned above, in the third embodiment of the present invention, the laser light 13a is reflected a total of twice by the reflecting mirrors 67b3 and 67b4 on its optical path after it penetrated through the lens 69 and reaches the photosensitive drum 71. On the other hand, the laser light 13b is reflected a total of twice by the separating mirror 68 and the reflecting mirror 67c on its optical path after it penetrated through the lens 69 and reaches the photosensitive drum 71. Further, the laser light 13d is reflected a total of twice by the separating mirror 68' and the reflecting mirror 67d on its optical path after it penetrated through the lens 69 and reaches the photosensitive drum 71. Accordingly, the numbers of reflections among the three laser lights 13a, 13b and 13d are the same and any difference in numbers of reflections between each of said laser lights is 0.
Now will be described below a fourth embodiment of the invention.
FIG. 9 is a schematic side elevation to illustrate one example of a construction of the two-beam optical system of the fourth embodiment of the invention.
Incidentally, in the fourth embodiment of the invention of FIG. 9, those elements numbered identically with the first embodiment of FIG. 3 perform the same or similar functions, and their explanation will be omitted here.
The only difference is the fourth embodiment from the first embodiment are the optical paths of the laser lights 13a and 13b after those lights 13a and 13b have through the lens 69. In other words, the composite laser light 13c which penetrated through the lens 69 reaches the separating mirror 68 first. As in the case of the first embodiment, the separating mirror 68 separates the laser lights 13a and 13b from the composite laser light 13c by transmitting the laser light 13a and by reflecting the laser light 13b out of the composite laser light 13c, respectively.
After penetrating through the separating mirror 68, an optical path of the laser light 13a separated from the composite laser light 13c by the separating mirror 68 directly reaches the photosensitive drum 71. On the other hand, after being reflected by the separating mirror 68, an optical path of the laser light 13b separated from the composite laser light 13c by the separating mirror 68 is reflected by the reflecting mirror 67c disposed on the optical path and reaches the photosensitive drum 71.
FIG. 10 is a schematic view to illustrate configurations of scanning lines La and Lb to be formed on the photosensitive drum 71 by the laser lights 13a and 13b, respectively.
Assuming that there is formed an upwardly convex arcing scanning line at a point where a laser light penetrates through the lens 69, for example, the laser light 13a which was not reflected by any reflecting mirrors, forms the upwardly convex arcing scanning line La (shown by the broken line in FIG. 10) on the photosensitive drum 71. On the other hand, the laser light 13b which was reflected a total of twice by the separating mirror 68 and the reflecting mirror 67c forms the upwardly convex arcing scanning line Lb (shown by the solid line in FIG. 6) on the photosensitive drum 71. As a result, two scanning lines La and Lb formed on the photosensitive drum 71 by the laser lights 13a and 13b, respectively are in a parallel relationship with each other.
Where an image of a black line and an image of a red line which are in a parallel relationship with each other are formed in a multi-color image, there are formed the image of a black line by such an upwardly convex scanning line La of the laser light 13a as shown by the broke line in FIG. 10 and the image of a red line by such a upwardly convex scanning line Lb of the laser light 13b as shown by the solid line in FIG. 10. As a result, the images of the both lines are not crossed, and reproduction images faithful to the originals are obtained as a hard copy.
As mentioned above, in the fourth embodiment of the present invention, the laser light 13a is not reflected by any reflecting mirrors on its optical path after it penetrated through the lens 69 and reaches the photosensitive drum 71. On the other hand, the laser light 13b is reflected a total of twice by the separating mirror 68 and the reflecting mirror 67c on its optical path after it penetrated through the lens 69 and reaches the photosensitive drum 71. Accordingly, the difference in numbers of reflections between the both laser lights 13a and 13b is 2.
Meanwhile, in the above-mentioned embodiment, dichroic mirrors are employed as the composing mirrors 63 and 63' and the separation mirrors 68 and 68', however a polarization beam splitter which functions according to an angle of polarization of a laser light, a prism, and the like may be employed.
As this invention may be embodied in several forms without departing from the spirit of the essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims:
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A multi-beam optical system is provided with reflecting mirrors and separating mirrors on optical paths of light beams for each color so that the difference of the numbers of reflections of the scanned light beams for the respective colors when they penetrate through the lens and reach the photosensitive drum can be the same or an even number. The ference of the number of reflections of the scanned light beams for the respective color can become an even number and the scanning lines are distorted in the same direction by the lens, and are thus not liable to lose a parallel relation between the line images.
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[0001] This application claims the benefit of and priority from Japanese Applications No. 2002-212785 filed Jul. 22, 2002 and No. 2002-281576 filed Sep. 26, 2002, the 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 cap device that is detachably attached to a tank opening member.
[0004] 2. Description of the Related Art
[0005] One known example of the cap device is disclosed in JP No. 10-329861A. FIG. 38 is a partly broken view illustrating a prior art fuel cap 200 for a vehicle. The fuel cap 200 includes a casing body 202 , and a cover 210 attached to an upper flange 204 of the casing body 202 . The flange 204 has an outer ring element 206 for fixation of the cover 210 and a linkage element 208 for linkage with the casing body 202 . The linkage element 208 has a fragile portion including a notch 209 . The fragile portion makes a starting point of breaking the linkage element 208 when a large external force in any of diverse directions is applied to the flange 204 via the cover 210 . In the case of application of a large external force onto the periphery of the fuel cap 200 , for example, due to a collision of the vehicle, this structure breaks the linkage element 208 at the fragile portion and thereby keeps the sealing properties of a fuel tank from the outside.
[0006] The fuel cap 200 of the prior art structure may, however, be broken at the fragile portion to be unusable even by a simple inadvertent use other than a collision of the vehicle, for example, a careless drop of the fuel cap 200 during fuel supply or application of a twisting static load to the lower end of the cover 210 .
[0007] Setting the breaking load at the fragile portion to a specific range of loading, which excludes the possible load level in the case of the inadvertent use, however, has lots of difficulties, since the setting is adjustable only by the direction and the depth of the notch 209 in the narrow flange 204 .
SUMMARY OF THE INVENTION
[0008] The object of the present invention is thus to solve the drawback of the prior art technique and to provide a cap device of a simple structure that is not easily damaged by an inadvertent operation, such as a careless drop of a cap, and ensures the sufficient sealing properties even under application of an external load.
[0009] To solve the above problem, the present invention provides a cap device that opens and closes a tank opening. The cap device comprises a closer that closes the tank opening, a handle mechanism operable to open and close the tank opening, a disk-shaped torque member that is rotatably mounted on the closer, the torque member being configured to transmit rotational torque applied to the handle mechanism to open and close the tank opening to the closer and a plate attachment mechanism that rotatably attaches the torque member to the closer. The plate attachment mechanism is configured such that part of the torque member is elastically deforms by an external force applied to the handle mechanism, thereby detaching the torque member from the closer.
[0010] In the cap device of the present invention, when a rotational torque either in the closing direction or in the opening direction is applied to the manipulation mechanism in the state of the closer set on the tank opening, the rotational torque is transmitted via the torque member to the closer and makes the closer close the tank opening.
[0011] The torque member is attached to the closer in a rotatable manner by the plate attachment mechanism. The plate attachment mechanism is configured to elastically deform part of the torque member or part of the closer, so as to be coupled with and released from the closer. The torque member is thus readily attached to and detached from the closer by elastic deformation of the constituent of the plate attachment mechanism, which corresponds to part of the torque member or part of the closer.
[0012] The load of making the torque member detached from the closer is readily set by changing the shape and the number of the elastically deformed constituents of the plate attachment mechanism or their mechanical strength. This arrangement thus facilitates optimized setting of the breaking load against external forces in a diversity of directions with no restriction by the shape of the sealing portion of the closer.
[0013] The plate attachment mechanism supports the torque member on the closer in a rotatable manner. This structure desirably reduces a variation in rotational torque due to a displacement of the torque member in the diametral direction or in the vertical direction, thus ensuring a stable clamping force to attain the sufficient sealing properties.
[0014] In one preferable application of the present invention, the cap device further includes a handle attachment mechanism that supports the manipulation mechanism on a circumference of the torque member in a freely rotatable manner. Elastic deformation of the handle attachment mechanism, which corresponds to part of the torque member, attains attachment and detachment of a cover member and a handle included in the manipulation mechanism. This arrangement facilitates attachment and detachment of the cover member and the handle from the torque member and ensures easy disengagement of the cover member or the handle under application of an external force.
[0015] A careless drop of the cap during fuel supply may apply a large external force to the cap and cause the cover member or the handle to be detached from the torque member. The detached cover member or handle can be attached again to the torque member by elastic deformation of he handle attachment mechanism. This arrangement desirably prevents the cap device from being unusable only by a careless drop of the cap, unlike the prior art cap that is easily broken at the fragile portion.
[0016] In one preferable embodiment of the above application, the manipulation mechanism includes a handle, and a cover member that is joined with the handle and encircles an upper portion and the circumference of the torque member. The handle attachment mechanism includes an elastically deformable interlocking claw formed on one of the cover member and the torque member, and a matched interlocking element formed on the other of the cover member and the torque member to engage with the interlocking claw.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is an illustrative diagram showing in partial cutaway a cap device comprising a fuel cap pertaining to a first embodiment of the invention;
[0018] [0018]FIG. 2 is an illustrative diagram showing in partial cutaway a cap device rotatable by grasping the handle with the fingers and raising it up;
[0019] [0019]FIG. 3 is an illustrative diagram showing the relationship of the casing interlocking portion of the casing body to the filler neck;
[0020] [0020]FIG. 4 is a plan view showing the cover;
[0021] [0021]FIG. 5 is a perspective view showing parts on top of the fuel cap disassembled;
[0022] [0022]FIG. 6 is a front view showing the handle detached from the cover;
[0023] [0023]FIG. 7 is a front view showing an enlargement of the area around the axially supported portion of FIG. 6;
[0024] [0024]FIG. 8 is a diagram viewed in the direction of arrow 8 in FIG. 7;
[0025] [0025]FIG. 9 is an illustrative diagram illustrating the procedure for assembling the handle to the cover;
[0026] [0026]FIG. 10 is a sectional view taken along line 10 - 10 in FIG. 7;
[0027] [0027]FIG. 11 is a sectional view showing the handle prior to being assembled with the axial support portion;
[0028] [0028]FIGS. 12A, 12B and 12 C are illustrative diagrams illustrating the procedure for rotating the handle;
[0029] [0029]FIG. 13 is a perspective view showing the fuel cap disassembled;
[0030] [0030]FIG. 14 is an illustrative diagram illustrating the clutch mechanism in non-interconnected mode;
[0031] [0031]FIG. 15 is an illustrative diagram illustrating the clutch mechanism in interconnected mode;
[0032] [0032]FIG. 16 is an illustrative diagram illustrating the relationship of the handle to the button of the clutch member;
[0033] [0033]FIG. 17 is a sectional view taken in the vicinity line 17 - 17 in FIG. 15;
[0034] [0034]FIGS. 18A, 18B and 18 C are illustrative diagrams illustrating operation of the first clutch unit;
[0035] [0035]FIG. 19 is an illustrative diagram illustrating the second clutch unit;
[0036] [0036]FIGS. 20A and 20B are illustrative diagrams illustrating operation of the second clutch unit;
[0037] [0037]FIG. 21 is a perspective view showing the torque member;
[0038] [0038]FIG. 22 is a perspective view showing principal elements of the torque member enlarged;
[0039] [0039]FIG. 23 is a sectional view of the area around the top of the casing body;
[0040] [0040]FIG. 24 is a perspective view showing the torque transmission mechanism;
[0041] [0041]FIG. 25 is a plan view showing the torque transmission mechanism;
[0042] [0042]FIG. 26 is an illustrative diagram illustrating operation carrying over from FIG. 25;
[0043] [0043]FIG. 27 is an illustrative diagram illustrating operation carrying over from FIG. 26;
[0044] [0044]FIGS. 28A and 28B are illustrative diagrams illustrating frangible portion of the torque portion;
[0045] [0045]FIG. 29 is a sectional view of the area around the tether mechanism;
[0046] [0046]FIG. 30 is a plan view of the tether mechanism;
[0047] [0047]FIG. 31 is a perspective view illustrating the tether mechanism;
[0048] [0048]FIG. 32 is a perspective view illustrating operation of the tether mechanism;
[0049] [0049]FIG. 33 is an illustrative diagram illustrating operation carrying over from FIG. 32;
[0050] [0050]FIG. 34 is a perspective view showing the rear end of a vehicle being fueled with the fuel cap detached from the filler neck;
[0051] [0051]FIGS. 35A, 35B and 35 C are illustrative diagrams illustrating operation of the handle;
[0052] [0052]FIGS. 36A, 36B and 36 C are illustrative diagrams illustrating operation of the handle;
[0053] [0053]FIG. 37 is a graph illustrating the relationship of angle of rotation to rotational torque applied to handle;
[0054] [0054]FIG. 38 is a sectional view showing a cap device
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0055] (1) General Structure of Fuel Cap 10
[0056] [0056]FIG. 1 is an illustrative diagram showing in partial cutaway a cap device comprising a fuel cap 10 (cap) pertaining to a first embodiment of the invention. In FIG. 1, the fuel cap 10 is attached to a filler neck FN having a filler opening FNb (tank opening) for supplying fuel to a fuel tank, not shown. The cap 10 comprises a casing body 20 (closer) made of polyacetal or other synthetic resin material, an inner cover 30 closing the upper opening of the casing body 20 , forming a valve chamber 24 ; a regulator valve 35 housed within the valve chamber 24 ; a cover 40 made of nylon or other synthetic resin and mounted on the upper portion of the casing body 20 ; a handle 45 mounted on the upper face of the cover 40 ; a clutch mechanism 60 and the torque transmission mechanism 80 (interconnecting mechanism); a tether mechanism 100 ; and a gasket GS installed on the outside rim of the upper portion of the casing body 20 to provide a seal between the casing body 20 and the filler neck FN.
[0057] In the fuel cap 10 shown in FIG. 2, grasping the handle 45 and raising it upward while rotating allows the fuel cap 10 to be attached to or detached from the filler neck FN to close or open the filler opening FNb. External pressure in the opening direction applied to the cover 40 and the handle 45 in the upper portion of the fuel cap 10 will simply cause it to turn freely, so that the fuel cap 10 does not come away from the filler neck FN.
[0058] (2) Arrangement of Parts
[0059] The various parts of the fuel cap 10 pertaining to the present embodiment are described in detail hereinbelow.
[0060] (2)-1 The Casing Body 20
[0061] In FIG. 1, the casing body 20 comprises a substantially round outer tube 21 and a valve chamber molding 22 integrally provided to the interior of the outer tube 21 . The valve chamber molding 22 houses a positive pressure valve and negative pressure valve that function as a regulator valve 35 . The inner cover 30 is welded by an ultrasonic welding technique onto the upper portion of the valve chamber molding 22 to form the valve chamber 24 .
[0062] The gasket GS is installed to the outside of the bottom edge of a flange 21 b in the upper portion of the casing body 20 . The gasket GS is interposed between a seal retaining portion 21 a of the flange 21 b and the filler opening FNb of the filler neck FN so as to be forced against the seating face of the filler neck FN when the fuel cap 10 is tightened in the filler opening FNb, providing a sealing action.
[0063] [0063]FIG. 3 is an illustrative diagram showing the relationship of the casing interlocking portion 20 a of the casing body 20 to the filler neck FN. The casing interlocking portion 20 a is formed on the bottom outside wall of the outer tube 21 . A opening interlocking portion FNc is formed on the inside wall of the filler neck FN. In a portion of the inside wall of the opening interlocking portion FNc is formed a neck insertion notch FNd into which the casing interlocking portion 20 a is insertable in the axial direction. With the casing interlocking portion 20 a aligned with the neck insertion notch FNd and the fuel cap 10 inserted into filler opening FNb of the filler neck FN, turning the fuel cap 10 by a predetermined angle (about 90°) causes the casing interlocking portion 20 a to be engaged by the opening insertion notch FNc to attach the fuel cap 10 to the filler neck FN.
[0064] (2)-2 Inner Cover 20
[0065] As shown in FIG. 1, the inner cover 30 has a flange 32 formed on the outside wall of the inner cover 30 , the bottom edge of the flange 32 being ultrasonically welded to the top of the valve chamber molding 22 .
[0066] (2)-3 Structure of the Cover 40
[0067] The cover 40 comprises an upper wall 41 and a side wall 43 formed at the outside rim of the upper wall 41 , integrally molded in a cup configuration. Support projections 43 a extend from the lower interior of the side wall 43 . The support projections 43 a are arranged at six equidistant locations along the inside rim of the side wall 43 . The support projections 43 a mate with the outside rim of the torque member 90 of the torque transmission mechanism 80 to rotatably attach the cover 40 to the casing body 20 via the torque member 90 . The cover 40 attachment structure is described in detail later.
[0068] [0068]FIG. 4 is a plan view showing the cover 40 . The cover 40 is made of polyamide (PA), polyethylene (PP), acrylonitrile-butadiene-styrene (ABS) or polycarbonate (PC). The cover 40 is made of conductive resin material so as to constitute part of a ground path, indicated by the double-dotted lines in FIG. 2. The conductive resin material may be imparted with electrical conductivity by adding a metal filler (e.g. stainless steel, nickel, chromium, zinc, copper, aluminum, gold, silver, magnesium or titanium filler or some combination thereof) etc. Metal filler content is from 1 to 30 wt %. The reason is that amounts of less than 1 wt % do not give electrical conductivity, whereas in excess of 30 wt % the resin becomes highly viscous in injection molding process of the cover 40 , possibly resulting in injection molding defects due to metal filler clogging or pooling.
[0069] An indicia portion DP is formed on the surface of the upper wall 43 of the cover 40 . The indicia portion DP comprises of indicia such as text describing function, warning, description line, record or bar code, marked by laser irradiation. 0.01 to 3 wt % of carbon is added for the purpose of laser irradiation. Marking by laser irradiation is not possible with carbon content below 0.01 wt %, whereas in excess of 3 wt % the energy of the laser is absorbed by the cover 40 as a whole, so that localized coloration in the indicia portion DP is not possible.
[0070] (2)-4 Structure of Handle 45
[0071] [0071]FIG. 5 is a perspective view showing parts on top of the fuel cap disassembled. The handle 45 comprises a rectangular handle body 46 with chamfered corners. The handle body 46 is of semicircular configuration having an actuating recess 46 a produced by recessing its outside edge at the center. The actuating recess 46 a serves as a recessed location for inserting a finger to provide ease of operation when the handle 45 has been lowered into the retracted position (see FIG. 1).
[0072] (2)-5 Axial Support Mechanism 50
[0073] The handle 45 is rotatably mounted on the upper wall 41 of the cover 40 by means of an axial support mechanism 50 . The axial support mechanism 50 comprises axial support portions 51 , 51 projecting from the upper wall 41 of the cover 40 , and axially supported portions 55 , 56 formed on the handle 45 and rotatably supported by the axial support portions 51 , 52 .
[0074] (2)-5-1 Axial Support Portions 51 , 52
[0075] [0075]FIG. 6 is a front view showing the handle 45 detached from the cover 40 . The axial support portions 51 , 52 are members for rotatably supporting the handle 45 and are provided in a pair in the center of the cover 40 . The axial support portion 51 comprises a leg portion 51 a and an axle portion 51 b projecting from the side of the leg portion 51 a , and the handle 45 is rotatable about the axle portion 51 b while supported thereby. The axial support portion 52 comprises a leg portion 52 a and an axle portion 52 b projecting from the top of the leg portion 52 a . An axle hole 52 f is formed in the side of the axle portion 52 b.
[0076] (2)-5-2 Axially Supported Portions 55 , 56
[0077] The axially supported portions 55 , 56 are formed extending from the bottom to the center of the handle 45 and are provided so that the handle 45 may be supported via the axial support portions 51 , 52 provided on the cover 40 . The axially supported portion 55 comprises an opening 55 a open at the bottom and at one side of the handle 45 , and an axle hole 55 b of round cross section communicating with the opening 55 a in the axial direction. The opening 55 a and the axle hole 55 b are configured to axially support the axle portion 51 b of the axial support portion 51 .
[0078] The axially supported portion 56 comprises an opening 56 a , and has a pin mounting hole 56 g connecting with the opening 56 a . FIG. 7 is a front view showing an enlargement of the area around the axially supported portion 56 of FIG. 6, and FIG. 8 is a diagram viewed in the direction of arrow 8 in FIG. 7. The pin mounting hole 56 g communicating with the opening 56 a is formed on the side of the opening 56 a . Pin mounting hole 56 g passes through the side of the handle 45 . A pin 56 h fits into the pin mounting hole 56 g . The distal end of the pin 56 h has a support insert 56 i for insertion into an axle hole 52 f.
[0079] (2)-5-3 Assembly of the Handle 45
[0080] [0080]FIG. 9 is an illustrative diagram illustrating the procedure for assembling the handle 45 to the cover 40 . To assemble the handle 45 to the cover 40 by means of the axial support mechanism 50 , the axial support portion 51 is mated with the axially supported portion 55 , and then the axial support portion 51 is inserted into the opening 56 a of the axially supported portion 56 , the inserting the pin 56 h into the pin mounting hole 56 g ; finally, the support insert 56 i is mated with the axle hole 52 . In this way the handle 45 may be rotatably mounted on the cover 40 via the axial support mechanism 50 .
[0081] (2)-5-4 Urging Mechanism 57
[0082] [0082]FIG. 10 is a sectional view taken along line 10 - 10 in FIG. 7, and FIG. 11 is a sectional view showing the handle 45 prior to being assembled. The handle 45 is urged towards the retracted position by means of the urging mechanism 57 . The urging mechanism 57 comprises a cam 58 projecting from the side of the axial support portion 52 , and a cam support portion 59 provided to the handle 45 . In FIG. 11, a cam face 58 a of the cam 58 is defined by center axis O 1 , an arcuate face 58 b of substantially semicircular configuration of radius r 1 , a center O 2 offset from center axis O 1 , and a curving convex face 58 c of radius r 2 . The cam support portion 59 is bifurcated so that the cam face 58 a is held between a resilient cam support piece 59 a and a cam support rib 59 b . The resilient cam support piece 59 a is configured as a cantilever piece that resiliently flexes while following the cam face 58 a as the handle 45 rotates. On the inside of the resilient cam support piece 59 a is formed a cam guide face 59 c conforming in shape to the arcuate face 58 b . The cam support rib 59 b is integrally formed with the handle body 46 and is arranged substantially parallel to the resilient cam support piece 59 a.
[0083] [0083]FIG. 12 illustrates the procedure for rotating the handle 45 . The handle 45 is supported such that it can rotate within a 90° range by means of the axial support mechanism 50 , that is, upraised from the retracted position pressed against the upper wall 41 of the cover 40 as shown in FIG. 12(A) to the position shown in FIG. 12(B), and finally to the upraised handling position shown in FIG. 12(C). When the handle 45 is not in the retracted position it is urged towards the retracted position (in the direction indicated by the arrow in FIG. 12(B)) by means of the urging mechanism 57 . That is, when the handle 45 is positioned at an angle between the retracted position and the handling position, the resilient cam support piece 59 a pushes under spring force against the arcuate face 58 b of the cam 58 , whereby the resilient cam support piece 59 a exerts pushing force towards center O 2 . Since this pushing force is eccentric with respect to center axis O 1 (which is the center of rotation of the handle 45 ), counterclockwise moment M 1 is created. This moment M 1 translates to force rotating the handle 45 about center axis O 1 . The handle 45 is thereby urged in the counterclockwise direction towards the retracted position from any position between the handling position and retracted position.
[0084] (2)-6 Clutch Mechanism 60
[0085] [0085]FIG. 13 is a perspective view showing the fuel cap 10 disassembled, FIG. 14 is an illustrative diagram illustrating the clutch mechanism 60 in non-interconnected mode, and FIG. 15 is an illustrative diagram illustrating the clutch mechanism 60 in interconnected mode. The clutch mechanism 60 is a mechanism for transmission/non-transmission to the torque transmission mechanism 80 of rotational torque applied to the handle 45 , and comprises a clutch member 70 , a clutch spring 92 and the clutch arm 93 formed on the torque portion 90 , and a cam face 62 formed on the lower face at both sides of the handle 45 .
[0086] (2)-6-1 Clutch Member 70
[0087] In FIG. 13, the clutch member 70 is integrally molded by injection molding and comprises a clutch body 71 . The clutch body 71 comprises an upper wall 72 of circular disk shape and a side wall extending downwardly from the outside edge of 72 so that the space surrounded by the upper wall 72 and the side wall 73 forms a storage recess 71 a (see FIG. 14).
[0088] The upper wall 72 has an annular projection 72 a projecting therefrom. As shown in FIG. 14 this annular projection 72 a prevents the two from becoming wedged together so as to facilitate vertical motion of the clutch member 70 . The upper wall 72 shown in FIG. 13 has buttons 74 , 74 projecting therefrom at locations 180° apart with respect to the center of the clutch member 70 . The buttons 74 , 74 are retractably positioned in through-holes 41 a formed in the cover 40 .
[0089] (2)-6-2 Clutch Urging Mechanism 61
[0090] Three the clutch springs 92 are positioned at 120° intervals about the circumference on the upper face of the torque member 90 . The clutch springs 92 impart spring force in the vertical direction relative to the clutch member 70 . Each the clutch springs 92 comprises an arm 92 a coplanar with the upper face of the torque member 90 and extending in the circumferential direction, and a pushing projection 92 b projecting up from the upper face of the torque member 90 at the distal end of the arm 92 a . The clutch springs 92 are of cantilever design, with one end thereof inclinable within a notch 92 c in the upper face of the torque member 90 , thereby urging the clutch member 70 upwardly.
[0091] [0091]FIG. 16 is an illustrative diagram illustrating the relationship of the handle 45 to the button 74 of the clutch member 70 . The upper face of the button 74 is a sloped the pushing face 74 a . A cam face 62 for pushing against the pushing face 74 a is formed on the lower face of the handle 45 at both sides. The cam face 62 is designed so that with the handle 45 in the handling position, the button 74 of the clutch member 70 is pushed downwardly, and so that in the retracted position the button 74 s not pushed downwardly.
[0092] With this arrangement for the clutch urging mechanism 61 , rotating the handle 45 from the retracted position shown in FIG. 14 to the handling position shown in FIG. 15 causes the cam face to push against the pushing faces 74 a of buttons 74 , 74 , so that the clutch member 70 is pushed downwardly in opposition to the urging force of the clutch springs 92 and moves to the lower position, whereas in the retracted position, force ceases to be applied to buttons 74 , 74 so that the clutch member 70 is returned to its original position by the clutch springs 92 .
[0093] (2)-6-3 First Clutch Unit 63
[0094] [0094]FIG. 17 is a sectional view taken in the vicinity line 17 - 17 in FIG. 15, and FIG. 18 illustrates operation of the first clutch unit 63 . The first clutch unit 63 is a mechanism for transmitting rotational torque applied to the handle 45 in the closing direction, regardless of whether the handle is in the handling position or retracted position.
[0095] The first clutch teeth 75 are formed all the way around the inside rim of the side wall 73 of the clutch member 70 . The first clutch teeth 75 comprise a right-angled the interlocking face 75 a extending in the radial direction and a sloping face 75 b inclined a predetermined angle with respect to the interlocking face 75 a ; the teeth are substantially right triangular in shape when viewed in cross section.
[0096] On the outside rim of the torque member 90 there are provided clutch arms 93 for interlocking with interlocking faces 75 a . The clutch arms 93 are positioned at 120° intervals about the circumference on the upper outside rim of the torque member 90 . Each the clutch arm 93 comprises an arm 93 a extending along the circumferential direction, and a interlocking end 93 b provided at the distal end of the arm 93 a . The interlocking end 93 b is formed by a surface in the radial direction so as to interlock with a interlocking face 75 a . The interlocking face 75 a is thicker than the interlocking end 93 b so as to normally maintain the interlocked state regardless of whether positioned above (FIG. 18(A)) or below (FIG. 18(B)) the torque member 90 of the clutch member 70 .
[0097] As shown in FIGS. 81 (A) and (B), when the clutch member 70 is rotated in the clockwise direction, the interlocking end 93 b interlocks with the interlocking face 75 a , creating a torque transmission state in which the torque member 90 rotates in unison therewith in the clockwise direction. This torque transmission state is maintained regardless of whether the handle 45 is in the handling position of FIG. 18(A) or the handling position of FIG. 18(B), since in either state the interlocking face 75 a of the clutch member 70 is in abutment with the interlocking end 93 b.
[0098] On the other hand when the clutch member 70 is rotated in the counterclockwise direction as illustrated in FIG. 18(C), there results a non-interconnected mode in which the sloping face 75 b of the first clutch teeth 75 follows along the outside face of the arm 93 a so that the torque member 90 does not rotate. In this way the first clutch teeth 75 and clutch arms 93 constitute a one-way clutch mechanism which normally interlocks in the clockwise direction (closing direction) to transmit rotational torque, and which does not transmit rotational torque in the counterclockwise direction (opening direction).
[0099] (2)-6-4 Second Clutch Unit 65
[0100] [0100]FIG. 19 is an illustrative diagram illustrating the second clutch unit 65 . The second clutch unit 65 is a mechanism for transmitting rotational torque applied in the opening direction to the handle 45 , only when the handle is in the handling position.
[0101] The second clutch teeth 76 are formed all the way around the bottom outside rim of the upper wall 72 of the clutch member 70 . Each the second clutch teeth 76 comprises a substantially vertical the interlocking face 76 a and a sloping face 76 b inclined by a predetermined angle with respect to the interlocking face 76 a , to produce a substantially right triangular cross section.
[0102] On the upper face of the torque member 90 are formed second clutch interlocking portions 94 for interlocking with the second clutch teeth 76 . The second clutch interlocking portions 94 are positioned at 120° intervals about the circumference in the upper portion of the torque member 90 . Each the second clutch interlocking portion 94 comprises a vertical interlocking face 94 a interlocking with a interlocking face 76 a , and a sloping face 94 b abutting a sloping face 76 b.
[0103] [0103]FIG. 20 illustrates operation of the second clutch unit 65 . As shown in FIG. 20(A), when the clutch member 70 is positioned upwardly by the spring force of the clutch spring 92 of the clutch mechanism 60 , the interlocking faces 76 a of the clutch member 70 are not interlocked with the interlocking faces 94 a of clutch interlocking portions 94 . Therefore the torque member 90 does not rotate even if the clutch member 70 is rotated.
[0104] As shown in FIG. 20(B), when the clutch member 70 is positioned downwardly in opposition to the spring force of the clutch spring 92 of the clutch mechanism 60 , the interlocking faces 76 a of the clutch member 70 interlock with the interlocking faces 94 a of clutch interlocking portions 94 . Turning the clutch member 70 is the counterclockwise direction (opening direction) causes the torque member 90 to rotate in unison therewith in the same direction. In this way, the second clutch teeth 76 and second clutch interlocking portions 94 constitute a one-way clutch mechanism that transmits rotational torque only when the torque member 90 is in the down position, while not transmitting rotational torque in the clockwise direction.
[0105] (2)-7 Structure of the Torque Member 90
[0106] [0106]FIG. 21 is a perspective view showing the torque member 90 . The torque member 90 comprises a two-stage disk of resin having a projecting portion and interlocking portion in its center. That is, the torque member 90 comprises a torque plate body 91 . The torque plate body 91 comprises an upper disk 91 a , an annular portion 91 b situated at the outside bottom of the upper disk 91 a , and connector portions 91 c connected at three locations to the annular portion 91 b . The upper disk 91 a comprises a clutch spring 92 which carries the clutch mechanism 60 described earlier, and is provided on its outside edge with clutch arms 93 .
[0107] (2)-7-1 Torque Member 90 Mounting Structure
[0108] As shown in FIG. 22, the interlocking claws 97 are formed on the inside rim of the annular portion 91 b of the torque member 90 . The interlocking claws 97 are configured as tongue pieces extending towards the center of the torque member 90 and are resiliently deformable in the axial direction. FIG. 23 is a sectional view of the area around the top of the casing body 20 . An interlocking recess 21 c is formed around the upper outside rim of the outer tube 21 of the casing body 20 . The interlocking claws 97 are forced into the interlocking recess 21 c to rotatably mount the torque member 90 on the upper outside rim of the casing body 20 .
[0109] An interlocking recess 91 d is formed around the outside rim of the annular portion 91 b , allowing the cover 40 of the torque member 90 to be rotatably supported within the interlocking recess 91 d by detaining therein the support projection 43 a on the inside wall of the side wall 43 of the cover 40 (see FIG. 1).
[0110] (2)-7-2 Structure of the Torque Transmission Mechanism 80
[0111] The torque transmission mechanism 80 shown in FIG. 1 is a mechanism that enables confirmation that the fuel cap 10 has been attached to the filler neck FN at a predetermined level of rotational torque, by providing the user with a tactile warning if excessive rotational torque above a predetermined level is applied to the handle 45 during the operation of closing the filler opening FNb with the fuel cap 10 .
[0112] [0112]FIG. 24 is a perspective view showing the torque transmission mechanism 80 , and FIG. 25 is a plan view showing the torque transmission mechanism 80 . The upper inside rim of the outer tube 21 has formed thereon a body interlocking portion 25 constituting part of the torque transmission mechanism 80 , described later. The body interlocking portion 25 extends around the entire inside circumference of the outer tube 21 and has a peak configuration composed of a first interlocking face 25 a slanted substantially in the circumferential direction and a second interlocking face extending substantially in the radial direction.
[0113] An inner annular portion 91 e of hollow cylindrical configuration is formed in the bottom of the upper disk 91 a of the torque member 90 , and three the resilient torque pieces 95 are formed at 120° intervals about the circumference on the outside edge of the inner annular portion 91 e . As shown in FIG. 25, the resilient torque pieces 95 take the form of arched cantilever pieces having their support points at the supporting terminal portions 95 a , and having the torque piece interlocking portions 96 projecting from their outside edges, with the spaces 95 c to the inside of the torque piece interlocking portions 96 . Each the torque piece interlocking portion 96 has a first interlocking face 96 a formed on a first face thereof and a second interlocking face 96 b formed on a second face. First interlocking face 96 a is configured so as to come into abutment at a vertical face thereof with a first interlocking face 25 a of the body interlocking portion 25 with clockwise rotation of the torque member 90 ; when pushed in the radial direction from the center by a body interlocking portion 25 the torque piece interlocking portions 96 undergoes resilient deformation so as to the constrict space 95 c , as shown in FIG. 26.
[0114] (2)-7-3 Torque Member 90 Breaking Mechanism
[0115] As shown in FIG. 28(A), the frangible grooves 98 a constituting part of the frangible portions 98 are formed along the outside edge of the upper disk 91 a of the torque member 90 , between it and the connector portion 91 c . The frangible grooves 98 a are located at three areas in the circumferential direction, these the frangible grooves 98 a being provided along the circumference of a circle connecting the cutout portions between connector portions 91 c in the circumferential direction.
[0116] Referring now to FIG. 28(B), if the cover 40 or the handle 45 should be subjected to a strong external force such as that produced in an automobile collision, the frangible portions 98 supporting the cover 40 will separate at the outside edges thereof or the interlocking claws 97 will detach from the interlocking recess 21 c beginning at the frangible portions 98 . At this time the seal retaining portion 21 a of the casing body 20 supporting the gasket GS is not damaged so that the seal is not lost. An additional reason for providing the torque member 90 with the frangible portions 98 is that by forming the frangible portions 98 in the upper portion of the casing body 20 there are no limitations as to the shape of the seal retaining portion 21 a , making it a simple matter to optimize breaking load for external forces in various directions.
[0117] (2)-8 Tether Mechanism 100
[0118] [0118]FIG. 29 is a sectional view of the area around the tether mechanism 100 , FIG. 30 is a plan view of the tether mechanism 100 , and FIG. 31 is a perspective view illustrating the tether mechanism 100 . The tether mechanism 100 is designed to prevent the fuel cap 10 from falling off or becoming lost during fueling, and comprises a tether rotation support 101 , a connector member 110 , and a support end 120 . As shown in FIG. 29, the tether rotation support 101 is rotatably supported on one end of a support wall 99 of the torque member 90 . Specifically, the tether rotation support 101 has an annular configuration extending all the way around the support wall 99 and has an open square cross section defined by an outer the annular outer wall 102 , the floor 103 and annular the inner wall 104 , with an annular recess 101 a therebetween. The outer the annular outer wall 102 is taller than annular the inner wall 104 . The interlocking projections 102 a project from the inside face of the annular outer wall 102 . As shown in FIG. 30, the interlocking projections 102 a are situated at six locations equal distances apart along the circumference, and when the interlocking claws 99 a of the support wall 99 are snapped into the annular recess 101 a these interlock with the interlocking projections 102 a as shown in FIG. 29 so that the tether rotation support 101 is rotatably supported on the torque member 90 .
[0119] The tether mechanism 100 is integrally molded by injection molding of thermoplastic elastomer (TPEE) or thermoplastic resin (e.g. PP). As shown in FIG. 30 a first end of the connector member 110 is connected to the tether rotation support 101 , inclined with respect thereto by a predetermined angle a (5°-180°). The connector member 110 comprises a connector member body 112 and a flex portion 114 . The flex portion 114 is located in proximity to a first connecting end 110 a at one end of the connector member 110 . Flex portion 114 is composed of inverted “U” shapes connected together in a substantially “S” configuration and is coplanar with the tether rotation support 101 so that when subjected to force in the direction indicated by arrow d 1 in FIG. 32 the connector member body 112 will bend along the outside perimeter of the cover 40 .
[0120] In FIG. 31 a support end 120 is formed at a second connecting end 110 b at the other end of the connector member 110 . The support end 120 is of tabular configuration fanning out towards the distal end and is formed by twisting at a right angle, i.e. 90°, with respect to the connector member 110 . A detent projection 122 projects from the support end 120 . As shown in FIG. 34, the detent projection 122 is rotatably supported on a support portion formed on the back face of the fuel cover FL. When fuel cover FL is opened away from the filler neck FN the fuel cap 10 is suspended via the connector member 110 fixed to the support end 120 . When at this point the fuel cap 10 is released the cover 40 of the fuel cap 10 drops toward the exterior panel of the vehicle, suspended away from the vehicle panel due to the 90° bend with respect to the connector member 110 , enabling the fueling operation. That is, the fuel cap is located away from the vehicle panel during fueling and therefore does not interfere with the fuel nozzle and preventing fuel on the casing body 20 from dripping onto the vehicle panel.
[0121] With the fuel cap 10 removed, the fuel cap 10 is then replaced in the filler opening FNb of the filler neck FN and the handle 45 turned in the closing direction shown in FIG. 32; as the tether rotation support 101 is rotatable with respect to the torque member 90 (FIG. 29), and as the connector member 110 is not subjected to any appreciable force from the fuel cover FL or the fuel cap 10 so as to remain slack on a substantially straight line, the opening/closing operation of the fuel cap 10 is not impaired. At this time the connector member 110 flexes at the flex portion 114 so that the connector member body 112 flexes along the outside perimeter of the cover 40 .
[0122] When fuel cover FL (FIG. 34) is subsequently shut the connector member body 112 is pushed longitudinally from the position illustrated in FIG. 32 in association with the motion of fuel cover FL. Longitudinal force on the connector member body 112 is converted to force tending to rotate the tether rotation support 101 in the counterclockwise direction so that the tether rotation support 101 rotates smoothly causing the connector member body 112 to coil around the cover 40 as illustrated in FIG. 33. Since the connector member body 112 coils around the cover 40 in this way it can be accommodated within the space behind the fuel cover FL and does not hinder opening and closing of the fuel cover FL.
[0123] As shown in FIG. 29, the tether rotation support 101 of the tether mechanism 100 is supported by a torque member 90 of polyacetal having a smooth surface, enabling it to rotate smoothly about the outside rim of the torque member 90 so that the opening/closing operation of the fuel cap 10 is not impaired. The torque member 90 is moreover fabricated of highly swelling-resistant polyacetal and therefore experiences negligible change in shape that would increase outside diameter, so that the ability of the tether rotation support 101 to rotate is not diminished. Further, as the tether rotation support 101 is formed of pliable thermoplastic elastomer (TPEE) or thermoplastic resin (PP) bending thereof at the flex portion 114 can be assured.
[0124] (3) Fuel Cap 10 Assembly Procedure
[0125] To assemble the fuel cap 10 , first, the handle 45 is attached to the cover 40 as shown in FIG. 9. The regulator valve 35 is also installed in the valve chamber 24 of the casing body 20 as shown in FIG. 1, and the flange 32 of the inner cover 30 is ultrasonically welded onto the upper portion of the valve chamber molding 22 . Next, as shown in FIG. 23, the interlocking claws 97 of the torque member 90 are forced into the interlocking recess 21 c of the casing body 20 to attach the torque member 90 to the casing body 20 . The button 74 of the clutch member 70 is aligned with the through-hole 41 a in the cover 40 , attaching the clutch member 70 to the cover 40 and then interlocking the support projection 43 a of the cover 40 with the interlocking recess 91 d to attach the cover 40 onto the torque member 90 . Then as shown in FIG. 29 the tether rotation support 101 of the tether mechanism 100 is forced over the interlocking claws 99 a of the support wall 99 to attach the tether mechanism 100 to the torque member 90 . This completes assembly of the fuel cap 10 .
[0126] (4) Fuel Cap 10 Operation
[0127] Following is a description of the opening and closing operation when attaching or replacing the fuel cap 10 in the filler opening FNb of the filler neck FN.
[0128] (4)-1 Fuel Cap 10 Closing Operation
[0129] With the fuel cap 10 detached from filler opening FNb, the handle 45 is pulled upright with the fingers as shown in FIG. 14, whereupon the handle 45 rotates about axial support portions 51 , 52 shown in FIG. 14, in opposition to the spring force of the urging mechanism 57 (see FIG. 10) and the clutch spring 92 (see FIG. 20). Rotation of the handle 45 causes the cam face 62 to push against the pushing face 74 a of the button 74 of the clutch member 70 . The clutch member 70 then moves downwardly in opposition to the urging force of the clutch spring 92 of the torque member 90 as shown in FIG. 15.
[0130] Next, as shown in FIG. 3 the casing interlocking portion 20 a of the casing body 20 is aligned with the neck insertion notch FNd of the filler neck FN and inserted therein in the axial direction. Clockwise force is then applied to the handle 45 and is transmitted to the clutch member 70 via the cover 40 , the cover 40 the through-hole 41 a and the button 74 of the clutch member 70 , causing the clutch member 70 to rotate. Since the interlocking faces 75 a of the first clutch teeth 75 normally interlock with the interlocking ends 93 b of clutch arms 93 of the torque member 90 as shown in FIG. 18(A), the torque member 90 rotates in tandem with rotation of the clutch member 70 . It should be noted that even if the user does not move the handle 45 to the handling position, i.e., even with the handle in the retracted position, the interlocking ends 93 b are interlocked with the interlocking faces 75 a as shown in FIG. 18(B) so that rotational torque is transmitted from the clutch member 70 to the torque member 90 .
[0131] As the torque member 90 rotates, the first interlocking faces 96 a of the torque piece interlocking portions 96 of the torque member 90 press against first interlocking faces 25 a of body interlocking portions 25 at the interlock locations illustrated in FIG. 25. This causes the handle 45 , the cover 40 , the clutch member 70 , the torque member 90 and the casing body 20 to rotate in unison in the direction of closing the filler opening FNb, with the casing interlocking portions 20 a (see FIG. 3) interlocking with opening interlocking portion FNc with increasing force. When reaction force created by this interlocking force exceeds a predetermined level of rotational torque, the torque piece interlocking portions 96 in the state shown in FIG. 26 now ride over the body interlocking portions 25 .
[0132] At this point the first interlocking faces 96 a of the torque piece interlocking portions 96 are forced in the radial direction by the reaction force from the first interlocking faces 25 a , causing the resilient torque pieces 95 to resiliently deform so as to constrict the width of the spaces 95 c , so that the torque piece interlocking portions 96 ride up over body interlocking portions 25 . This provides to the user with a tactile warning of over-tightening. In this state the fuel cap 10 is attached to the filler opening FNb at a predetermined level of tightening torque.
[0133] When the handle 45 is subsequently released it is subjected to spring force created by the resilient cam support piece 59 a pinching the cam face 58 (see FIG. 36) and to the spring force of the clutch spring 92 transmitted to handle via the button 74 , and rotates about axial support portions 51 , 52 to return to the retracted position.
[0134] (4)-2 Fuel Cap 10 Closed State
[0135] In the state shown in FIG. 1, the handle 45 , the cover 40 , and the clutch member 70 are not constrained in the opening direction (counterclockwise direction) by the torque member 90 and the casing body 20 , and thus rotate freely. Thus, if the cover 40 and/or the handle 45 should be subjected to external force as in a collision, they will simply turn freely without rotational torque being transmitted to casing member 20 through the torque transmission mechanism 80 , so that there is no loss of seal.
[0136] (4)-3 Procedure for Opening the Fuel Cap 10
[0137] The procedure for opening the fuel cap 10 is initiated by pulling up the handle 45 as shown in FIG. 15. This causes the cam face 62 in the lower center of the handle 45 to push against the pushing face 74 a of the button 74 of the clutch member 70 , so that the clutch member 70 moves downwardly. In this state, turning the handle 45 counterclockwise causes the interlocking faces 76 a of the second clutch teeth 76 to interlock with the interlocking faces 94 a of second clutch interlocking portions 94 as shown in FIG. 20(B), so that the torque member 90 rotates in the counterclockwise direction in tandem with rotation of the clutch member 70 in the same direction.
[0138] In this state, the second interlocking faces 96 b of the torque piece interlocking portions 96 interlock with the second interlocking faces 25 b of body interlocking portions 25 as shown in FIG. 27. The second interlocking faces 96 b and the second interlocking faces 25 b come into abutment substantially in the radial direction and do not produce center-directed force tending to cause the resilient torque pieces 95 to constrict the spaces 95 c , so that the torque piece interlocking portions 96 do not ride over body interlocking portions 25 , but instead transmit rotational torque applied to the handle 45 to the casing body 20 . As a result the handle 45 , the cover 40 , the clutch member 70 , the torque member 90 and the casing body 20 rotate in unison in the clockwise direction.
[0139] The casing interlocking portion 20 a then comes away from the opening interlocking portion FNc of the filler neck FN so that the casing body 20 is released from the constraining force of the filler neck FN. The fuel cap 10 can now be removed from the filler neck FN by pulling out in the axial direction.
[0140] (4)-4 Operation of the Handle 45 the Urging Mechanism 57
[0141] [0141]FIG. 35 illustrates the return operation of the handle 45 by the clutch spring 92 , and FIG. 36 illustrates the return operation of operation of the handle 45 by the urging mechanism 57 . When opening or closing the handle 45 , the handle 45 is rotated from the retracted position to the handling position; this is done in opposition to rotational torque returning the handle 45 to the retracted position, due to spring force of the clutch spring 92 and the urging mechanism 57 . Rotational torque is normally energized in the return direction is for the following reasons.
[0142] (1) As the vehicle is driven the handle 45 is kept flat on the cover so as to not project significantly thereabove, making it more difficult for the handle 45 to be subjected to external force.
[0143] (2) Chattering of the handle 45 is reduced so that strange noises are not produced during driving.
[0144] The reason for using two resin springs as the urging mechanism 57 and the clutch spring 92 to produce rotational torque in the return direction is as follows.
[0145] [0145]FIG. 37 is a graph illustrating the relationship of angle of rotation to rotational torque applied to the handle. In FIG. 37, rotational torque produced by the urging mechanism 57 is graphed by a broken line, rotational torque produced by the clutch spring 92 by a dotted and dashed line, and total rotational torque applied to the handle 45 by a solid line. As will be apparent from FIG. 37, the urging mechanism 57 is set to high rotational torque at small angles of less than 45°, while the clutch spring 92 is set to high rotational torque at large angles of from 45° to 90°.
[0146] Rotational torque levels are set in this way for the following reason. The spring force produced by the urging mechanism 57 depends on the shape of the cam face 58 a of the cam 58 , making it difficult to produce a shape for a cam that can generate a high level of rotational torque over a wide control range. For the clutch spring 92 to generate rotational torque over a wide control range it would be necessary for the torque member 90 to move with a large stroke. Further, where only a single resin spring is used to generate rotational torque over a wide control range it will be necessary for the resin spring to flex appreciably, which over a period of several years may lead to failure. By using instead two resin springs, it is possible to achieve rotational torque for stable return over a wide range of 0-90°.
[0147] (5) Working Effects of the Fuel Cap 10
[0148] In addition to the working effects described above, the fuel cap 10 affords the following working effects.
[0149] (5)-1 In the process of closing the fuel cap 10 , tactile warning is provided when the torque piece interlocking portions 96 of the torque member 90 ride up over body interlocking portions 25 of the casing body 20 as shown in FIGS. 25 and 26, so that the user may determine that the fuel cap 10 has been tightened to a predetermined level of torque, thereby allowing the cap to be attached to a predetermined level of torque regardless of any resilience on the part of the gasket GS etc.
[0150] (5)-2 With the fuel cap 10 closing the filler opening FNb as shown in FIG. 1, the clutch member 70 does not move in tandem with the casing body 20 in the opening direction, due to the clutch mechanism 60 , and thus even if the handle 45 should be subjected to force in the opening direction due to some unforeseen external force, it will simply turn freely with respect to the casing body 20 . Therefore the casing body 20 will not be subjected to external force applied to the handle 45 and will remain seated in the filler opening FNb. The fuel cap 10 can therefore maintain a seal without becoming loosened by unforeseen external force.
[0151] (5)-3 With the fuel cap 10 attached to filler opening FNb as shown in FIG. 1, the handle 45 is placed in the retracted position by spring force and returns to this position from the upraised handling position during the opening/closing operation, and is therefore not susceptible to external force such as that occurring in a vehicle collision or the like, so that it is not subjected to force tending to loosen the fuel cap 10 . Additionally, even where the handle 45 is of appreciable size, since it is positioned laying flat on the upper wall 41 of the cover 40 in the closed position, a minimal amount of space around the filler opening is required to accommodate it.
[0152] (5)-4 As shown in FIG. 24, the body interlocking portions 25 of the torque transmission mechanism 80 are formed at equal distances all the way around the inner cover 30 , whereby rotational torque may be transmitted immediately to the casing body 20 without changing the position of the handle 45 , and whereby uniform rotational torque may be transmitted regardless of the position of the torque piece interlocking portions 96 .
[0153] (5)-5 With the fuel cap 10 in the closed state, the handle 45 turns freely in the opening direction whereby the user may turn the handle 45 to the desired position, improving ease of opening/closing.
[0154] (5)-6 As shown in FIG. 1, with the fuel cap 10 in the closed state the handle 45 can be visually confirmed to be lowered into the retracted position, and it will be readily understood that opening/closing can be accomplished by upraising it, thereby providing superior operation to the button operation arrangement described in the prior art.
[0155] (5)-7 As shown in FIG. 18, the first clutch unit 63 transmits rotational torque even when the handle 45 is not in the handling position, so that even if the user neglects to move the handle 45 to the handling position it is still possible to close the tank opening with the casing body 20 . The first clutch unit 63 (FIG. 18) and the second clutch unit 65 (FIG. 20) turn freely in the opening direction when the handle 45 is in the retracted position, so that the casing body 20 will not be rotated by external force and will not lose seal.
[0156] The foregoing detailed description of the invention has been provided for the purpose of explaining the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use contemplated. The foregoing detailed description is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Modifications and equivalents will be apparent to practitioners skilled in this art and are encompassed within the spirit and scope of the appended claims.
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A fuel cap has a torque member attached to an upper portion of a casing body. The torque member is a disk-shaped plate to transmit a rotational torque applied to a handle to the casing body. An interlocking recess and interlocking claws, which constitute a plate attachment mechanism, are arranged on the upper portion of the casing member. Fitting of the interlocking claws in the interlocking recess causes the torque member to be attached to the casing body in a freely rotatable manner. This simple structure of the invention effectively prevents the fuel cap from being easily damaged by an inadvertent operation, such as a careless drop of the fuel cap, and ensures the sufficient sealing properties of the fuel cap even under application of an external load.
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CROSS REFERENCE TO RELATED APPLICATIONS
This invention claims priority of the German patent applications 100 30 013.8 and 101 15 590.5 which are incorporated by reference herein.
FIELD OF THE INVENTION
The invention relates to a scanning microscope having a laser that emits a light beam of a first wavelength, which is directed onto an optical element that modifies the wavelength of the light beam at least to some extent.
BACKGROUND OF THE INVENTION
In scanning microscopy, a sample is scanned with a light beam. To that end, lasers are often used as the light source. For example, an arrangement having a single laser which emits several laser lines is known from EP 0 495 930: “Laser for confocal microscope”. Mixed gas lasers, especially ArKr lasers, are mainly used for this at present.
Examples of samples which are studied include biological tissue or sections prepared with fluorescent dyes. In the field of material study, illumination light reflected from the sample is often detected.
Solid-state lasers and dye lasers, as well as fiber lasers and optical parametric oscillators (OPOs), upstream of which a pump laser is arranged, are also used.
Laid-open patent specification DE 198 53 669 A1 discloses an ultrashort-pulse source with controllable multiple-wavelength output, which is used especially in a multiphoton microscope. The system has an ultrashort-pulse laser for producing ultrashort optical pulses of a fixed wavelength and at least one wavelength conversion channel.
U.S. Pat. No. 6,097,870 discloses an arrangement for generating a broadband spectrum in the visible spectral range. The arrangement is based on a microstructured fiber, into which the light from a pump laser is injected. The wavelength of the pump light is modified in the microstructured fiber so that the resulting spectrum has both wavelengths above and wavelengths below the wavelength of the pump light.
So-called photonic band gap material or “photonic crystal fibers”, “holey fibers” or “microstructured fibers” are also employed as microstructured material. Configurations as a so-called “hollow fiber” are also known.
Solid-state lasers, such as e.g. the Ti:sapphire lasers commonly used in scanning microscopy, usually have a folded resonator with x or z geometry, which is formed by two end mirrors and two folding mirrors. The light from a pump laser is in this case injected longitudinally in the resonator through one of the folding mirrors, which are transparent for light at the wavelength of the pump light. In the optically active medium (in the example, Ti:sapphire), the latter converts to another wavelength and leaves the resonator as output light through one of the end mirrors, which is designed to be semitransparent for the output light. Since the resonator mirrors are not fully transparent for the wavelength of the pump light, the output light still contains small fractions of light at the wavelength of the pump light. This more especially causes interference in multicolour fluorescence microscopy, since the sample is not illuminated and excited exclusively with light at the desired wavelength, but also with light at the wavelength of the pump light. This causes undesired fluorescences, artefacts and in the final analysis, since components of the pump light also reach the detector by reflection and scattering, leads to incorrect study results.
All known arrangements for wavelength modification have this disadvantage.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a scanning microscope with a flexible illumination which avoids the illumination of a sample with light of unwanted wavelengths.
The object is achieved by a scanning microscope comprising: a laser that emits a light beam of a first wavelength, an optical element that modifies the wavelength of the light beam at least to some extent and means for suppressing the light of the first wavelength in the modified-wavelength light beam.
The invention has the advantage that the undesired illumination of the sample by light of the first wavelength is avoided.
In a simple configuration, a filter is provided for suppressing the light of the first wavelength. It is preferably designed as a dielectric cut-off filter or as a coloured-glass filter. Especially when using microstructured material, such as photonic band gap material, for modifying the wavelength in such a way as to create a broad spectrum, it is advantageous to configure the filter in such a way, for example by corresponding coating, that the first wavelength is not fully suppressed but rather, within the modified-wavelength light beam, has the same power as the other components of equal spectral width.
In another configuration, the means for suppressing the light of the first wavelength contains a prism or a grating for spatial spectral spreading, downstream of which an aperture arrangement, which transmits only light of the desired illumination wavelength and blocks light that has the first wavelength, is arranged.
The suppression means can be fitted at arbitrary points within the beam path of the scanning microscope. It is particularly advantageous to arrange the suppression means directly behind the optical element, in order to prevent scattering and reflection of the light components of the first wavelength by other optical parts, since such components can reach the detector in this way.
In a preferred configuration of the scanning microscope, the optical element is constructed from a plurality of micro-optical structure elements, which have at least two different optical densities.
A more particularly preferred configuration is one in which the optical element contains a first region and a second region, the first region having a homogeneous structure and a microstructure comprising micro-optical structure elements being formed in the second region. It is also advantageous if the first region encloses the second region. The micro-optical structural elements are preferably cannulas, webs, honeycombs, tubes or cavities.
In another configuration, the optical element includes adjacent glass or plastic material and cavities, and is configured as an optical fiber.
A more particularly preferred alternative embodiment, which is simple to implement, contains a conventional optical fiber having a fiber core, which has a taper at least along a subsection, as the optical element. Optical fibers of this type are known as so-called “tapered fibers”. The optical fiber preferably has an overall length of 1 m and a taper over a length of from 30 mm to 90 mm. The diameter of the fiber, in a preferred configuration, is 150 μm outside the region of the taper, and that of the fiber core in this region is approximately 8 μm. In the region of the taper, the diameter of the fiber is reduced to approximately 2 μm. The fiber core diameter is correspondingly in the nanometer range.
In another embodiment, the optical element is a further laser. It may be designed as a solid-state, gas or dye laser, or as an optical parametric oscillator (OPO).
In a particular alternative embodiment, the optical element contains a frequency-multiplication crystal, such as e.g. KDP crystals or LBO crystals.
Another configuration contains a further optical element, which is arranged downstream of the optical element and remodifies the wavelength of the modified-wavelength light beam. In this embodiment, it is particularly advantageous to suppress both the light of the first wavelength and the light whose wavelength was initially modified. Specifically, such a configuration contains, for example, a sequential arrangement of an argon-ion laser, a dye laser and a frequency-doubling crystal. A sequential arrangement of an argon-ion laser, a Ti:sapphire laser and, configured as an optical fiber, a micro-optical structure made of photonic band gap material is particularly advantageous.
The scanning microscope may be configured as a confocal microscope.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter of the invention is diagrammatically represented in the drawings and will be described below with the aid of the figures, in which:
FIG. 1 shows confocal scanning microscope according to the invention,
FIG. 2 shows a part of the illumination beam path of a scanning microscope,
FIG. 3 shows a part of the illumination beam path of another scanning microscope, and
FIG. 4 shows a part of the illumination beam path of a further scanning microscope
FIG. 5 shows an embodiment of the optical fiber made of photonic band gap material, which has a special honeycombed microstructure 69 . The honeycomb structure that is shown is especially suitable for generating broadband light. The diameter of the glass inner cannula 71 is approximately 1.9 μm. The inner cannula 71 is surrounded by glass webs 73 . The glass webs 73 form honeycombed cavities 75 . These micro optical elements together form a second region 77 , which is enclosed by a first region 79 that is designed as a glass cladding.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a confocal scanning microscope 1 , which contains a laser 2 for producing a light beam 5 having a first wavelength of about 800 nm. The laser is embodied as a mode-locked titanium-sapphire laser 3 . The light beam 5 is focused by an input lens 7 into the end of an optical element 9 for wavelength modification, which is designed as an optical fiber made of photonic band gap material 11 . To collimate the modified-wavelength light beam 15 emerging from the optical fiber made of photonic band gap material 11 , an output lens 13 is provided. The spectrum of the modified-wavelength light beam is virtually continuous over the wavelength range from 300 nm to 1600 nm, the light power being substantially constant over the entire spectrum; only in the vicinity of the first wavelength of 800 nm is a drastic power increase to be recorded. The modified-wavelength light beam 15 passes through a dielectric filter 17 as suppression means 16 , which reduces the power, in the modified-wavelength light beam 15 , of the light component in the vicinity of the first wavelength to the level of the other wavelengths of the modified-wavelength light beam. The modified-wavelength light beam is subsequently focused by the lens 19 onto an illumination aperture 21 , and then travels via the main beam splitter 23 to the scanning mirror 25 , which guides the modified-wavelength light beam 15 through the scanning lens 27 , the tube lens 29 and the objective 31 , and over the sample 33 . The detection light 35 , which is represented by dashes in the drawing, leaving the sample 33 travels through the objective 31 , the tube lens 29 and the scanning lens 27 back to the scanning mirror 25 , and then to the main beam splitter 23 , whereupon it is transmitted by the latter and, after having passed through the detection aperture 37 , it is detected by the detector 39 which is embodied as a photomultiplier.
FIG. 2 shows the part of the illumination beam path of a scanning microscope as far as the main beam splitter 23 . In this exemplary embodiment, a laser 2 , which is configured as an argon-ion laser 41 , produces a light beam 43 having a first wavelength of 514 nm, which is directed onto a titanium-sapphire laser 45 that is used as the optical element 9 for wavelength modification. The modified-wavelength light beam 47 leaving the titanium-sapphire laser 45 has a wavelength of approximately 830 nm and subsequently strikes the means 16 for suppressing the first wavelength, which is embodied as a colour filter 49 and almost completely filters out the components of the first wavelength, so that the modified-wavelength light beam essentially consists only of light at a wavelength of 830 nm.
FIG. 3 shows the part of the illumination beam path of a further scanning microscope as far as the main beam splitter 23 . In this exemplary embodiment, a laser 2 , which is configured as an Nd-YAG laser 51 , produces a light beam 53 having a first wavelength of 1064 nm, which is directed onto an optical parametric oscillator 55 that is used as the optical element 9 for wavelength modification. The modified-wavelength light beam 57 leaving the optical parametric oscillator 55 contains, in addition to the light at the desired signal wavelength, light at the idler wavelength and light at the first wavelength; it is spread with the aid of a prism 59 , as the means for spatial spectral splitting 60 , and subsequently strikes an aperture arrangement 61 whose aperture blocks 63 , 65 are positioned in such a way that the light at the idler wavelength and light at the first wavelength is blocked, so that the light beam passing through the aperture arrangement 61 essentially contains only light at the signal wavelength.
FIG. 4 shows the part of the illumination beam path of another scanning microscope as far as the main beam splitter 23 , which largely corresponds to the structure shown in FIG. 3 . Here, however, a grating 67 is used as the means for spatial spectral splitting 60 .
FIG. 5 shows an embodiment of the optical fiber made of photonic band gap material, which has a special honeycombed microstructure 69 . The honeycomb structure that is shown is especially suitable for generating broadband light. The diameter of the glass inner cannula 71 is approximately 1.9 μm. The inner cannula 71
The invention has been described with reference to a particular embodiment. It is, however, obvious that modifications and amendments may be made without thereby departing from the scope of protection of the following claims.
PARTS LIST
1 scanning microscope
2 laser
3 titanium-sapphire laser
5 light beam
7 input lens
9 optical element
11 optical fiber made of photonic band gap material
13 output lens
15 modified-wavelength light beam
16 suppression means
17 dielectric filter
19 lens
21 illumination aperture
23 main beam splitter
25 scanning mirror
27 scanning lens
29 tube lens
31 objective
33 sample
35 detection light
37 detection aperture
39 detector
41 argon-ion laser
43 light beam
45 titanium-sapphire laser
47 modified-wavelength light beam
49 colour filter
51 Nd-YAG laser
53 light beam of a first wavelength
55 optical parametric oscillator
57 modified-wavelength light beam
59 prism
60 means for spatial spectral splitting
61 aperture arrangement
63 aperture
65 aperture
67 grating
69 microstructure
71 cannulas
73 web
75 cavity
77 second region
79 first region
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The invention discloses a scanning microscope ( 1 ) having a laser ( 2 ), which emits a light beam of a first wavelength ( 5, 43, 53 ) and is directed onto an optical element ( 9 ) that modifies the wavelength of the light beam at least to some extent. Means ( 16 ) for suppressing the light of the first wavelength in the modified-wavelength light beam ( 5, 47, 57 ) are provided.
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This invention relates to connectors for automotive air conditioning systems in general, and specifically to a sealed connector that provides assured sealing contact in a high pressure environment.
BACKGROUND OF THE INVENTION
Heat exchangers used in automotive air conditioning systems, such as evaporators or condensers, must be removably connected to refrigerant carrying lines in the system, which are under high pressure. It is important that the seal be fluid tight, and it is advantageous that the connection be simple and reliable to make and break.
A typical connector currently in use is shown in FIG. 1, and indicated generally at (10). Connector (10) is used to connect both the inlet and outlet of an evaporator to a compressor suction line (12) and a condenser liquid line (14), in one step. The ends of the lines (12) and (14) are upset or shouldered at (16) and (18) to create an axial stop surface, and are received with radial clearance through two cylindrical sealing sockets (20) and (22) bored into the face of a connector block (24). Before the lines (12) and (14) are inserted, a pair of O-rings (26) and (28) are stretched over the ends of the lines (12) and (14) and against the stop shoulders (16) and (18). Finally, a clamping plate (30) is attached to block (24), by a central bolt (32) to clamp the stop shoulders (16) and (18) in place. The abutment of plate (30) with block (24) signals the assembler that the connection is complete. However, the compression control of the O-rings (26) and (28) arises not from the axial tightening of bolt (32) or from the abutment of plate (30), but instead from the radial interference with the sealing sockets (20) and (22).
An advantage of the typical connection just described is that the shoulders (16) and (18) act as retainers to prevent the rings (26) and (28) from being blown axially out of their sockets (20) and (22) by the high pressure refrigerant. A disadvantage is that the rings (26) and (28) may become damaged or cocked as they enter the sockets (20) and (22), especially with repeated making and breaking of the connection. Furthermore, the degree of compression of the seal is dependent upon the radial gap between the upset ends of the lines (12) and (14) and their respective sockets (20) and (22). That gap cannot be held as precisely as the gap between two machined surfaces.
SUMMARY OF THE INVENTION
The invention provides a connector in which the control of the seal compression is assured by the axial abutment of a pair of block members, and in which the metal retainer for the seal does not interfere with or cooperate in setting that seal compression.
In the embodiment disclosed, the connector handles a single refrigerant line. A first connector block has a refrigerant passage of predetermined diameter bored through it, opening through a flat primary engagement face. Counterbored into the face, and surrounding the passage opening, is an annular seal pocket that provides a primary seal face, axially inset from the engagement face. A second connector block has a matching, secondary engagement face, from which projects a tubular inlet sized to fit freely into the refrigerant passage, and surrounded by an annular shoulder that fits freely into the seal pocket. The shoulder is axially stepped, comprising an annular, secondary seal face surrounded by an annular relief notch.
A bolt or other clamping means is provided to hold the blocks snugly together. When the blocks are connected and the shoulder and seal pocket interfitted, a pair of axial gaps are created, a lesser thickness gap between the axially opposed seal faces, and a greater thickness gap between the primary seal face and the relief notch.
A sealing assembly is designed to cooperate with the two gaps. A metal retainer ring with a diameter matching the relief notch, but thinner than the greater gap, surrounds an elastomeric seal ring with a diameter matching the secondary seal face, and thicker than the lesser gap. Before the blocks are clamped together, the sealing assembly is placed between them, concentric to the refrigerant passage and inlet. The elastomeric ring is assured of complete, even compression between the axially opposed, accurately ground seal faces, without interference from the retainer.
DESCRIPTION OF THE PREFERRED EMBODIMENT
These and other features of the invention will appear from the following written description, and from the drawings, in which:
FIG. 1 is the prior art connector already described above;
FIG. 2 is a perspective view of a preferred embodiment of the connector of the invention;
FIG. 3 is a cross section through the connector with the various components axially parted and aligned;
FIG. 4 is an enlarged portion of the cross section of the blocks clamped together, without the seal assembly in place;
FIG. 5 is a view similar to FIG. 4, but showing the seal assembly in place as the connector blocks move together;
FIG. 6 is a view similar to FIG. 5, showing, the blocks clamped and the seal ring compressed.
Referring first to FIGS. 2 and 3, a preferred embodiment of the sealed connector of the invention is indicated generally at (34). The two main components are a first and second connector block, indicated at (36) and (38) generally, which are cylindrical in form and machined from aluminum. First connector block (36) is machined with a flat inner surface (40) that provides a primary engagement face. Bored through its center is a stepped cylindrical refrigerant passage (42). Welded into passage (42) at the outside of first block (36) is one part of a refrigerant line (44), which could be any line, such as the suction line from the evaporator outlet to the compressor inlet, or the liquid line from the condenser to the expansion valve. The inner diameter of passage (42) is determined in advance by the size of line (44), and is large enough so as to not constrict flow therethrough. Counterbored into face (40) and surrounding the other end of passage (42) is an annular seal pocket (46), which provides a flat primary seal face (48) that is axially inset from primary engagement face (40). In addition, the interface between primary seal face (48) and passage (42) is chamfered at (49), for a purpose described below.
Still referring to FIGS. 3 and 4, second connector block (38) is similar as to material and shape, with a flat inner surface (50) that provides a secondary engagement face abutable with (40). Projecting therefrom is a tubular inlet (52) sized to fit freely into passage (42), that is, with axial and radial clearance. The outer edge of tubular inlet (52) is chamfered at (53). At the outside of block (38), the other half of line (44) is welded in line with inlet (52). Surrounding inlet (52) is a stepped annular shoulder (54) which, in general, is sized to fit freely into seal pocket (46). More specifically, shoulder (54) comprises a radially inboard, annular secondary seal face (56) that is axially outset from secondary engagement face (50), and which is itself surrounded by an annular relief notch (58).
Referring next to FIG. 4, the ultimate result of the relative size and shape of the surfaces described above is illustrated. When the respective engagement faces (40) and (50) are abutted, with tubular inlet (52) plugged into passage (42), the secondary seal surface (56) and relief notch (58) create a pair of lesser thickness and greater thickness axial gaps relative to the axially opposed primary seal surface (48), indicated at X1 and X2 respectively. Since the surfaces are machined on solid metal blocks, they can be fairly accurately maintained, as compared to the radial gap in the prior art seal described above. Elsewhere, there is a significant radial gap between pocket (46) and shoulder (54,) and a small radial gap between passage (42) and inlet (52). Furthermore, a relief space is created between the chamfer (49) and passage (42), indicated by the circled area, which serves a purpose described below. Somewhere in this series of gaps, a complete blocking seal must be provided in order to prevent the leakage of the high pressure refrigerant out of line (44) and between the mated blocks (36) and (38).
Referring again to FIG. 3, a seal assembly, indicated generally at (60), provides the necessary seal. Seal assembly (60) includes an outboard annular steel retainer (62), with an axial thickness that is less than X2, but slightly greater than X1, and a diameter substantially equal to the relief notch (58). Integrally molded to the inside of retainer (62) is an annular elastomeric seal ring (64), molded of a suitable seal material. The axial thickness of seal ring (64) is approximately the same as its retainer (62), and its diameter is substantially equal to secondary seal face (56), but with its radially innermost edge being slightly smaller in diameter than the cylindrical outer surface of tubular inlet (52). It is not possible to control the dimensions of the elastomeric seal ring (64) as precisely as the steel retainer (62). However, by sizing it as described, dimensional control of that precision is not necessary, as described below.
Referring next to FIGS. 3 and 5, the initial steps in the final assembly of sealed connector (10) are illustrated. A clamping means, here a threaded bolt (66), is provided to draw the connector blocks (36) and (38) securely together in the axial direction. Before the bolt (66) is tightened, the seal assembly (60) is dropped in place in seal pocket (46), against primary seal face (48), and at least approximately centered with passage (42). Since retainer (62) has a fair degree of radial clearance relative to seal pocket (46), dropping it in place alone will not serve to precisely center it on passage (42), but precise centering is not necessary. This unencumbered drop in of seal assembly (60), it will be appreciated, is much simpler to accomplish than the push on installation of the O-rings described above.
Referring next to FIGS. 5 and 6, the next step is to align tubular inlet (52) with passage (42), which is easily achieved by the operator shifting the same shaped connector blocks (36) and (38) into alignment with each other. This alignment can be sensed manually if visual access is limited. Then, the bolt (66) is tightened. The chamfered edge (53) of tubular inlet (52), even if it is not precisely centered relative to seal ring (64), will eventually engage it, and will, given the flexibility of ring (64), shift ring (64) until it is centered. As bolt (66) continues to tighten, tubular inlet (52) enters passage (42), and shoulder (54) enters pocket (46). Eventually, the engagement faces (40) and (50) abut, which is easily sensed by the operator, and the tightening of bolt (66) is ended.
Referring finally to FIG. 6, the result of tightening bolt (66) to completion is illustrated. As tubular inlet (52) passes through the inner edge of seal ring (64), which, as noted above, is slightly undersized relative to it, some of the elastomeric material is drawn axially down. This seal material is sheared, in effect, between the two chamfered edges (49) and (53) as they move axially past one another, but is not cut or damaged by any sharp edges. As the blocks (36) and (38) seat on one another, the seal ring (64) is assured of complete and unrestricted axial compression between the primary seal face (48) and secondary seal face (56). Complete compression is assured both because seal ring (64) is thicker than X1, causing it to be squeezed down, and because the retainer (62) is less thick than X2, which guarantees that the retainer (62) will not bind between the blocks (36) and (38) to prevent their complete seating. In addition, retainer (62) can float axially in the gap X2, finding its own equilibrium position, which helps to prevent interference with the compression of ring (64). Any excess material from ring (64) displaced by the squeezing down process can shift axially down into the relief space described above, preventing overcompression and blocking the radial clearance between passage (42) and inlet (52). The net result is a complete sealing and blocking of the various gaps, both radial and axial, between inlet (52) and passage (42). Seal ring (64) will hold up to the very high pressures involved, since it is backed up by metal in more than one direction. That is, forces acting axially upwardly as viewed in FIG. 6, force seal ring (64) axially into flat secondary seal face (56). Forces acting radially outwardly are resisted by retainer (62). Should it be necessary to break the connection, seal assembly (60) will be visible, whether it stays in pocket (46) or remains on shoulder (54). If it needs replacement, it can be easily stripped off by grasping retainer (62), which is accessible, and replaced.
In conclusion, a high pressure, high reliability, easily handled and replaced seal is provided with a minimal number of component parts. The same advantages could be incorporated in other embodiments. For example, one block could be machined totally flush on it's inner surface, combining its engagement face and sealing face into one, in effect. Then, the other connector block would have an annular sealing face machined into it axially offset from its engagement face, so as to create the lesser thickness axial gap for compression of the seal ring. The relief notch could then be machined into either block, surrounding the secondary sealing face, and providing the greater axial gap to make room for the retainer. Therefore, it will be understood that it is not intended to limit the invention to the specific embodiment disclosed.
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A sealed connector for an automotive air conditioning system compresses a sealing ring between accurately ground, axially opposed sealing surfaces of a pair of mated connector blocks that are bolted together. A steel retainer to which the sealing ring is molded prevents it from being blown out under high pressure, and one of the connector blocks is relieved to accommodate the retainer, thereby preventing interference with the clamping of the blocks. Seal compression is even and complete.
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BACKGROUND OF THE INVENTION
It is common practice in the installation of concrete earth anchors, or deadmen, to drill holes with augers and to bell the holes at the bottom with a belling bucket. The belling time per hole has been 45-60 minutes. When the belling is done with the use of the procedure and apparatus of the present inventions, the belling time per hole is reduced to 3-5 minutes. This reduction in time is due to the fact that it is not necessary to remove the bell cuttings from the hole and to the fact that the belling tool does not load up during the belling operation.
SUMMARY OF THE INVENTION
The principal object of the invention is to make it possible to bell a ground anchor hole in a small fraction of the time required to do so under conventional belling practice.
This object is accomplished by limiting the downward movement of the belling bucket within the hole by means of holding cables interconnecting the bucket and the Kelly nut. These cables halt the downward movement of the bucket at a predetermined level above the bottom of the hole. Subsequent downward movement of the Kelly bar causes the cutting blades of the belling bucket to bell the hole. The belling bucket is modified to be open at the bottom so that the bell cuttings drop into and fill the lower end of the hole.
In a modified form of the apparatus of the invention, bell-cutting blades are attached to an auger. Once the hole has been drilled the auger is backed off from the bottom of the hole and holding cables are connected between the Kelly nut and the bell-cutting blades. Subsequent downward movement of the Kelly bar in the hole causes the blades to cut the bell and causes the bell cuttings to be deposited in the bottom of the hole.
DESCRIPTION OF THE DRAWING
FIG. 1 is a view partly in section and partly in elevation showing one embodiment of the apparatus of the invention positioned within a drilled hole for the bell-cutting operation.
FIG. 2 is a view similar to FIG. 1 showing the apparatus at the end of the bell-cutting operation.
FIG. 3 is a view similar to FIG. 1 of a further embodiment of the apparatus of the invention.
FIG. 4 is a view similar to that of FIG. 3 but showing the apparatus at the end of the bell-cutting operation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Pivotally mounted and self-powered drill heads are put on truck tractors for ready transport and use in the digging of ground anchor holes. Such equipment comprises Kelly bar 10, Kelly nut 12 and Kelly bar drive 14. Drive 14 operates to raise and lower the Kelly bar 10 and to rotate Kelly nut 12 to impart rotational movement to the bar 10.
The ground anchor hole 16, which is about 12 feet deep on the average, has been formed with an auger, not shown, which was attached to Kelly bar 10. Following the digging of hole 16, the bar 10 was raised and the auger was replaced with the belling apparatus shown in FIGS. 1 and 2.
The belling apparatus of FIGS. 1 and 2 comprises a cylindrical bucket or shell 18 open at both ends, link member 20 fixedly attached to bucket 18, cutting blades 22 pivotally connected to link 20 and projectable through slots 24 in the bucket 18, collar 26 removably attached to Kelly bar 10 as by pin 28, links 30 pivotally connected to blades 22 and to ears 32 on collar 26, and a pair of cables 34 interconnecting Kelly nut 12 and bucket 18. The cables 34 suspend the bucket 18 a predetermined distance above the bottom of hole 16.
Belling is accomplished by moving Kelly bar 10 downwardly from its FIG. 1 position to the position shown in FIG. 2 while bar 10 is driven in rotation by nut 12. The cables 34 maintain the bucket 18 and link 20 at the same vertical level as the Kelly bar is moved downwardly to progressively pivot the blades 22 from their FIG. 1 to their FIG. 2 position, thereby cutting the bell 36. The cuttings pass through slots 24 and through the open bottom end of bucket 18 to the lower end of hole 16.
After the belling operation, the Kelly bar is raised to its FIG. 1 position and thereafter the apparatus is withdrawn from hole 16.
In the embodiment of FIGS. 3 and 4 the drill auger 40 which was used to dig hole 16 is shown attached to Kelly bar 10 as by pin 42. Cutting blades 44 having pivotal connections 46 with auger collar 48 are provided for the belling operation. For the belling operation the cables 134 are provided in interconnecting relation with the cutting blades and Kelly nut 12. The cables 134 and blades 44 were not in place during the drilling of hole 16 with auger 40. Thereafter cables and blades are attached to the auger and the apparatus is put back in the hole 16 to the depth shown in FIG. 3. Subsequent rotative movement and downward movement of Kelly bar 10 causes the blades 44 to be swung from their FIG. 3 position to their FIG. 4 position to cut the bell 50. During this belling operation the cuttings pass downwardly along the auger into the cutting receptacle constituted by the bottom of hole 16.
The FIGS. 3-4 embodiment may be modified to cut a bell of the shape of FIG. 2 by connecting the cables to a ring carrying the pivotal connections 46 and connecting the collar 48 to the middle parts of the undersides of the blades through thrust links. Thus, as the Kelly bar is moved down the blades would be thrust outwardly about the stationary pivotal connections 46.
It is desirable to provide in all embodiments swivel hook connectors 52 between the upper ends of the cables and the Kelly nut 12 and to provide right below the swivel hooks a helical spring 54 in each cable constituting a flexible, stretchable part of the cable. The operator of the drill rig may then control the power applied to the Kelly bar in a way to avoid undue stretching of the springs. This enables the operator to so operate the rig as to minimize the breakage of parts. For example, undue stretching of the springs would indicate that the blades are about to become hung-up by taking too big a "bite" for the ground being worked. The operator would then reduce the "bite" accordingly.
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Cables attached to a rotating Kelly nut of a drill rig serve to maintain the vertical level of pivot points of bell-cutting blades while the blades are swung outwardly about these stationary pivot points to cut a bell for a drilled hole. The bell cuttings gravitate to the bottom of the drilled hole which is disposed a predetermined distance below the location of the bell.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an impact reducing sport equipment for use in connection with absorbing and dispersing, at least in part, an impact force.
2. Description of the Prior Art
The use of protective sport equipment and helmets is known in the prior art. Protective headgear such as helmets has been worn by users to protect from head injuries. Protective helmets have been used for many activities, including for participants in sports, such as but not limited to, football, hockey, baseball, lacrosse, racing, skiing), for commercial activities and for military personnel. Prior art helmets have generally comprised a single layer rigidly secured to the head of a user, or multiple layers including absorbing elements therebetween.
The known impact absorbing helmets are designed to reduce direct impact forces that can mechanically damage an area of contact. Known impact absorbing helmets will typically include padding and a protective shell to reduce the risk of physical head injury. Helmet liners are provided beneath a hardened exterior shell to reduce violent deceleration of the head. These types of protective gear are reasonably effective in preventing injury. Nonetheless, the effectiveness of protective gear remains limited.
While the above-described devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not describe an impact reducing sport equipment that allows absorbing and dispersing, at least in part, an impact force.
Therefore, a need exists for a new and improved impact reducing sport equipment that can be used for absorbing and dispersing, at least in part, an impact force. In this regard, the present invention substantially fulfills this need. In this respect, the impact reducing sport equipment according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provide an apparatus primarily developed for the purpose of absorbing and dispersing, at least in part, an impact force.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of protective headgear now present in the prior art, the present invention provides an improved impact reducing sport equipment, and overcomes the above-mentioned disadvantages and drawbacks of the prior art. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved impact reducing sport equipment and method which has all the advantages of the prior art mentioned heretofore and many novel features that result in an impact reducing sport equipment which is not anticipated, rendered obvious, suggested, or even implied by the prior art, either alone or in any combination thereof.
To attain this, the present invention essentially comprises a sport equipment for absorbing and dispersing, at least in part, an impact force, thereby reducing the impact force. The sport equipment can be a helmet having an outer shell, an inner shell, and a tensile sheet located between the outer and inner shells. The outer shell includes an interior side featuring a plurality of outer shell detents extending out therefrom. The inner shell includes an exterior side featuring a plurality of inner shell detents extending toward the outer shell. The tensile sheet is configured to dissipate and redirect, randomly directed impact force applied to the outer shell, to a tensile loading directed along a respective longitudinal axis of the tensile sheet. The outer and inner shells are in a spaced apart relationship with and movable to each other. The outer shell detents extend toward the inner shell.
The sport equipment can further include at least one fastener configured to pull the outer shell and the inner shell together, and a coupling member connecting a portion of the outer shell to a portion of the inner shell.
The outer shell can also include a plurality of outer shell troughs each adjacent to at least one of the outer shell detents, and the inner shell can also include a plurality of inner shell troughs each adjacent to at least one of the inner shell detents. With each of the outer shell detents configured to contact a first side of the tensile sheet, and each of the inner shell detents configured to contact a second side of the tensile sheet opposite the first side.
The outer shell troughs can be configured to receive a portion of the first side of the tensile sheet and a portion of at least one of the inner shell detents. Additionally, the inner shell troughs can be configured to receive a portion of the second side of the tensile sheet and a portion of at least one of the outer shell detents.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated.
The invention may also include an inflatable member configured to apply pressure against the tensile sheet. The inflatable member can be received in a groove defined adjacent a peripheral edge of the inner shell, with a portion of the inflatable member being configured to extend from the groove and contact the tensile sheet. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims attached.
Numerous objects, features and advantages of the present invention will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of presently preferred, but nonetheless illustrative, embodiments of the present invention when taken in conjunction with the accompanying drawings. In this respect, before explaining the current embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
It is therefore an object of the present invention to provide a new and improved impact reducing sport equipment that has all of the advantages of the prior art protective headgear and none of the disadvantages.
It is another object of the present invention to provide a new and improved impact reducing sport equipment that may be easily and efficiently manufactured and marketed.
An even further object of the present invention is to provide a new and improved impact reducing sport equipment that has a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such impact reducing sport equipment economically available to the buying public.
Still another object of the present invention is to provide a new impact reducing sport equipment that provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
Even still another object of the present invention is to provide an impact reducing sport equipment for absorbing and dispersing, at least in part, an impact force. This allows for converting a portion of an impact force to a tensile force, thereby reducing the impact force.
These together with other objects of the invention, along with the various features of novelty that 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 the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a perspective view of an embodiment of the impact reducing sport equipment constructed in accordance with the principles of the present invention, with phantom lines depicting environmental structure and forming no part of the claimed invention.
FIG. 2 is a cross-sectional view of the impact reducing sport equipment in a non-impacted state taken along line 2 - 2 of FIG. 1 .
FIG. 3 is an enlarged cross-sectional view of a section of the impact reducing sport equipment of FIG. 2 .
FIG. 4 is an enlarged cross-sectional view of a section of the impact reducing sport equipment in an impacted stated.
FIG. 5 is an enlarged cross-sectional view of a frontal section of an alternate embodiment inner shell of the impact reducing sport equipment.
FIG. 6 is an enlarged cross-sectional view of a rear section of the alternate embodiment inner shell of the impact reducing sport equipment.
FIG. 7 is an enlarged cross-sectional view of the frontal section of the alternate embodiment inner shell in a tensioned stated.
The same reference numerals refer to the same parts throughout the various figures.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and particularly to FIGS. 1-7 , an embodiment of the impact reducing sport equipment of the present invention is shown and generally designated by the reference numeral 10 .
In FIG. 1 , a new and improved impact reducing sport equipment 10 of the present invention for reducing the impact force on sport equipment by dispersing and converting a percentage of the impact force to tension is illustrated and will be described. More particularly, the impact reducing sport equipment 10 can be any sport equipment that receives impact, such as but not limited to, helmets, shoulder protectors, elbow protectors, knee protectors, thigh protectors, hip protectors, shin protectors, wrist protectors, arm protectors, chest protectors, spine protectors, neck protectors, face protectors, torso protectors, and abdomen protectors.
Alternatively, the impact reducing sport equipment 10 can also be sport equipment not worn by a player, such as but not limited to, baseballs, softballs, bats, hockey pucks, hockey sticks, footballs, polo mallets, walls, boards, backboards, goal posts or ground surfaces. The present application will describe, as an example, an embodiment of the present invention as associated with a football helmet 12 . However, it can be appreciated that the present invention can be associated with any impact protection equipment. Thus the following exemplary description does not limit the scope of the present invention to helmets.
The impact reducing sport equipment 10 can be a helmet 12 having an outer shell 14 , an inner shell 20 , a tensile sheet 30 between the outer and inner shells, multiple padding or shock absorbing elements 34 , and an optional inner liner or harness 36 , as best illustrated in FIGS. 1 and 2 . It can be appreciated that a face guard and/or chin strips can be removably attached to the helmet 12 . Furthermore, vent holes can be defined in the outer and/or inner shells.
The outer shell 14 includes an exterior side and an interior side. The interior side features a plurality of detents 16 extending toward the inner shell 20 , and a plurality of troughs 18 . The detents 16 can be, but not limited to, concentric ridges and troughs, radially distributed ridges and troughs, a plurality of protrusions or a sinusoidal profile. An apex or tip of the detents 16 can be rounded, squared or any geometric shape.
The inner shell 20 includes an exterior side toward the interior side of the outer shell 14 and an interior side. The exterior side of the inner shell 20 features a plurality of detents 22 extending toward the outer shell 14 , and a plurality of troughs 24 . The detents 22 can be, but not limited to, concentric ridges and troughs, radially distributed ridges and troughs, a plurality of protrusions or a sinusoidal profile. An apex or tip of the detents 22 can be rounded, squared or any geometric shape. The detents 22 and troughs 24 of the inner shell 20 are offset from the detents 16 and troughs 18 of the outer shell 14 , so that the detent 16 of the outer shell 14 is receivable in the trough 24 of the inner shell 20 and the detent 22 of the inner shell 20 is receivable in the trough 18 of the outer shell 14 .
The outer shell 14 and inner shell 20 can be made from the same or different materials, such as but not limited to, laminates, plastics, carbon fiber, polycarbonate, polymers, polyethylene, epoxy, metals, composites or alloys.
The tensile sheet 30 is positioned between the outer shell 14 and inner shell 20 , and can be secured at its peripheral edge to either the outer shell 14 of inner shell 20 . As an example and as best illustrated in FIG. 3 , the tensile sheet 30 is placed over the inner shell 20 and the peripheral edge of the tensile sheet 30 is wrapped around a peripheral edge of the inner shell 20 . The peripheral edge of the tensile sheet 30 can then be secured to the interior side of the inner shell 20 so that the tensile sheet 30 is stretched to a predetermined tensile force. The tensile sheet 30 can be, but not limited to, woven, laminated, layered or a fabric made from KEVLAR™ (para-aramid synthetic fiber), TWARON™ (para aramid), TECHNORA™ (aramid), INNAGRA S™ (polyolefin), DYNEEMA™ (Ultra-high-molecular-weight polyethylene), aramid, para aramid, polyamides, Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW), carbon nanotube, graphene, SPECTRA® (Ultra-high-molecular-weight polyethylene), spider silk, carbon/carbon composite, carbon fiber or silicon carbide fiber.
A coupling member 28 is positioned between the outer shell 14 and inner shell 20 . The coupling member is configured to join the interior side or edge of the outer shell 14 to the exterior side, an extension or edge 26 of the inner shell 20 . The coupling member 28 can be, but not limited to a rigid member, an elastomeric member, a shock absorbing member, a biasing member, an articulating member or a spring member. The coupling member 28 has a predetermined length so as to produce a gap 32 between the outer shell 14 and inner shell 20 . It can be appreciated that different sizes of coupling members 28 can be used to produce a predetermine gap 32 , which results in different pretension forces on the tensile sheet 30 and to an amount of travel of the outer shell 14 to the inner shell 20 .
A fastener 38 can be used to attach or couple the outer shell 14 and inner shell 20 , as best illustrated in FIG. 3 . The fastener 38 can pass through the coupling member 28 or can be associated at any location so as to pull the outer shell 14 toward the inner shell 20 , vice versa. The fastener 38 can also be configured to produce a pretension force to the tensile sheet 30 by compressing the outer shell 14 and inner shell 20 so that the detents 16 , 22 stretch the tensile sheet 30 . The pretension force can be adjusted by adjusting the clamping force produced by the fastener 38 .
As best illustrated in FIG. 2 , the helmet 12 is in a pre-impact state where the gap 32 has a first distance D 1 . It can be appreciated that the gap 32 can be filled with an impact absorbing material, such as but not limited to, elastomers, foams, plastics, rubbers, gels, fluids, gases, polymers, ferrofluids, SORBOTHANE® (visco-elastic polymer), PORON® (urethanes), biasing members, visco-elastics, ethylene vinyl acetate (EVA), neoprene, polyurethane gels, carbon fibers or D30®. The pretension force of the tensile sheet 30 has been predetermined and produced by the tension force of the tensile sheet 30 secured to the inner shell 20 , the size of the coupling member 28 , the clamping force of the fastener 38 or a combination thereof.
In use, it can now be understood that when a second helmet or object 2 impacts the outer shell 14 of the helmet 12 , an impact force IF is produced which pushes the outer shell 14 toward the inner shell 20 to an impacted state having a second distance D 2 therebetween. The impact force IF is distributed across multiple detents 16 of the outer shell 14 , which travel toward and are received in corresponding troughs 24 of the inner shell 20 . Simultaneously, multiple detents 22 of the inner shell 20 travel toward and are received in corresponding troughs 18 of the outer shell 14 . The impact force IF is transmitted through related detents 16 of the outer shell 14 to the tensile sheet 30 , which stretches the tensile sheet 30 . A portion of the impact force IF is converted to a tension force TF radiating through the tensile sheet 30 at the point of impact, thus allowing the tensile sheet 30 to stretch.
The remaining portion of the impact force or resultant force RF, which is less than the initial impact force IF, is transmitted from the tensile sheet 30 to the multiple detents 22 of the inner shell 20 and distributed to an area that is larger than the point of impact. The resultant force RF is further reduced and dispersed by the multiple padding or shock absorbing elements 34 , and the inner liner or harness 36 .
After impact, the outer shell 14 returns to its pre-impacted state and first distance D 1 , because the tensile strength returns the tensile sheet 30 to its original shape thus pushing against the detents 16 of the outer shell 14 . The tensile sheet 30 is configured to dissipate and redirect the impact force IF applied to the outer shell 14 , to a tensile loading directed along a respective longitudinal axis of the tensile sheet 30 .
In support of the above-identified claims, the impact force IF absorption and distribution by the tensile sheet 30 can be describes as the following, with the assumption that no fiber breakage occurs under low level of impact energy. When the impact or outer shell detents strikes the tensile sheet 30 , the impact force IF can be classified into two quantities. One is the elastic energy which is stored elastically in the tensile sheet and transferred back to the second helmet (impactor) and/or the outer shell detents 16 . Another is the absorbed energy which is the sum of the absorbed energy in the tensile sheet and inner shell by its damage initiation and propagation, and the energy absorbed by the impact system in vibration, heat, inelastic behavior of the impactor or supports. Thus, the following relationship described in Equation 1 holds under low velocity, low energy impacts.
E total =E reb +E abs Equation 1
where E reb is the rebound energy, E abs is the absorbed energy, and E total is the total energy. Thus, a portion of the absorbed energy is distributed through the helmet 12 as the tension force TF, prior to the resultant force RF reaching a person wearing the helmet 12 .
Two types of waves are formed just after impact which is the sudden local momentum transfer at time t=0. The first type consists of radially growing tensile waves through the tensile sheet, and these are followed by much slower transverse waves in the form of growing cones with the point of impact at their apexes. The impactor, which can be treated as the outer shell detents, is decelerated by the membrane forces generated as the waves propagate in the layers made up by the outer shell, tensile sheet, and inner shell.
It can be appreciated that the size or radius of the detents 16 , 22 can be changed to increase or decrease the surface area of the point of contact with the tensile sheet 30 so as to alter the impact force IF distribution to and from the tensile sheet 30 . For example, a larger radius of the detents 16 , 22 would increase the impact force surface area to and from the tensile sheet 30 , thus distributing the impact force IF over a larger area.
FIGS. 5-7 reference an alternate embodiment inner shell 20 , which includes a groove 40 defined in or near the peripheral edge. An inflatable member 42 is received in the groove 40 interior of the tensile sheet 30 . The inflatable member 42 includes a nipple or valve 44 for inflating or deflating the inflatable member 42 , as best illustrated in FIG. 6 .
In use, the inflatable member 42 can be inflated using the valve 44 so that a portion of the inflatable member 42 expands outside the groove 40 . During expansion, the inflatable member 42 will contact an interior side of the tensile sheet 30 and push a corresponding section of the tensile sheet 30 away from the peripheral edge of the inner shell 20 , as best illustrated in FIG. 7 . This pushing force will produce a gap G between the corresponding section of the tensile sheet 30 and the peripheral edge of the inner shell 20 , thus stretching the tensile sheet 30 to produce and control a pretension force on the tensile sheet 30 . The pretension force can be adjusted by inflating or deflating the inflatable member 42 a predetermined amount.
It can be appreciated that the inflatable member 42 can be replaced with a tensioning wire that when tightened by a control dial or lever would pull the tensile sheet 30 , and thus produce a pretension force.
While embodiments of the impact reducing sport equipment have been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. And although absorbing and dispersing, at least in part, an impact force have been described, it should be appreciated that the impact reducing sport equipment herein described is also suitable for any impact absorbing surface.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A sport equipment for absorbing and dispersing, at least in part, an impact force, thereby reducing the impact force. The sport equipment can be a helmet having an outer shell, an inner shell, and a tensile sheet located between the outer and inner shells. The outer shell includes an interior side featuring a plurality of outer shell detents extending out therefrom. The inner shell includes an exterior side featuring a plurality of inner shell detents extending toward the outer shell. The tensile sheet is configured to dissipate and redirect, randomly directed impact force applied to the outer shell, to a tensile loading directed along a respective longitudinal axis of the tensile sheet. The outer and inner shells are in a spaced apart relationship with and movable to each other. The outer shell detents extend toward the inner shell.
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CROSS REFERENCE TO RELATED APPLICATION
Pursuant to 35 U.S.C. §119(e), this application claims priority to U.S. Provisional Application Ser. No. 60/873,041, filed Dec. 5, 2006, the content of which is incorporated herein by reference.
BACKGROUND
The role of lymphangiogenesis in promoting metastasis via the lymphatic system has been the subject of extensive research. Vascular endothelial growth factor receptor-3 (VEGFR-3) is a major mediator of lymphangiogenesis. VEGF-C and VEGF-D are two ligands for VEGFR-3. Both of them were shown to stimulate lymphangiogenesis in transgenic mice. Specifically, three cancer cell lines transfected with VEGF-C or VEGF-D were recently reported to exhibit increased tumor lymphangiogenesis and undergo lymphatic metastasis. Clinical studies also revealed that increased expression of VEGF-C was associated with lymph node metastasis in a variety of cancers in human. Thus, it is desirable to develop novel drugs that inhibit VEGFR-3 activities for use in treating cancer.
SUMMARY
This invention is based on the discovery that certain indazole compounds are effective in reducing metastasis and treating cancer by inhibiting VEGFR-3 activities.
In one aspect, this invention features indazole compounds of formula (I):
In this formula, each independently is a double bond or single bond; each of X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , and X 7 , independently, is C or N, provided that at least two of X 1 , X 2 , and X 3 are N; and that when X 1 is N, R 1 is deleted, when X 3 is N, R 3 is deleted, when X 4 is N, R 4 is deleted, when X 5 is N, R 5 is deleted, when X 6 is N, R 6 is deleted, and when X 7 is N, R 7 is deleted; each of X 8 and X 9 , independently, is C or N + ; and each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 , independently, is H, C 1 -C 10 alkyl, C 2 -C 10 alkenyl, C 2 -C 10 alkynyl, C 3 -C 20 cycloalkyl, C 3 -C 20 cycloalkenyl, C 1 -C 20 heterocycloalkyl, C 1 -C 20 heterocycloalkenyl, aryl, heteroaryl, halo, CN, NO 2 , OR a , COOR a , OC(O)R a , C(O)R a , C(O)NR a R b , C(O)N(R a )N(R b )C(O)R c , NR a R b , N(R c )SO 2 NR a R b , SO 2 NR a R b , or SR a , in which each of R a , R b , and R c , independently, is H, C 1 -C 10 alkyl, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, or heteroaryl, or R a and R b together with the nitrogen atom to which they are attached form a C 1 -C 20 heterocycloalkyl or heteroaryl.
Referring to formula (I), a subset of the indazole compounds described above are those in which each of X 1 , X 4 , X 5 , X 6 , X 7 , X 8 , and X 9 , independently, is C and each of X 2 and X 3 , independently, is N. In these compounds, R 1 can be H or OR a ; R 2 can be C 3 -C 20 cycloalkyl, C 1 -C 10 alkyl optionally substituted with aryl or C 1 -C 20 heterocycloalkyl, or aryl optionally substituted with C 1 -C 10 alkyl; and each of R 4 , R 5 , R 6 , and R 7 , independently, can be H, C 1 -C 10 alkyl, NR a R b , COOR a , C(O)NR a R b , C(O)N(R a )N(R b )C(O)R c , or heteroaryl.
In another aspect, this invention features indazole compounds of formula (II):
In this formula, each of X 1 , X 2 , and X 3 , independently, is C or N, provided that at least two of X 1 , X 2 , and X 3 are N; and that when X 1 is N, R 1 is deleted, when X 2 is N, R 2 is deleted; and each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 , independently, is H, C 1 -C 10 alkyl, C 2 -C 10 alkenyl, C 2 -C 10 alkynyl, C 3 -C 20 cycloalkyl, C 3 -C 20 cycloalkenyl, C 1 -C 20 heterocycloalkyl, C 1 -C 20 heterocycloalkenyl, aryl, heteroaryl, halo, CN, NO 2 , OR a , COOR a , OC(O)R a , C(O)R a , C(O)NR a R b , C(O)N(R a )N(R b )C(O)R c , NR a R b , N(R c )SO 2 NR a R b , SO 2 NR a R b , or SR a , in which each of R a , R b , and R c , independently, is H, C 1 -C 10 alkyl, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, or heteroaryl, or R a and R b together with the nitrogen atom to which they are attached form a C 1 -C 20 heterocycloalkyl or heteroaryl.
Referring to formula (II), a subset of the indazole compounds described above are those in which X 1 is C, each of X 2 and X 3 , independently, is N, and each of R 3 , R 4 , R 5 , R 6 , and R 7 , independently, is H, C 1 -C 10 alkyl, NR a R b , COOR a , C(O)NR a R b , C(O)N(R a )N(R b )C(O)R c , or heteroaryl.
The term “compound” used herein includes both compounds and ions. For example, when X 8 or X 9 is N + , the compound of formula (I) is a cation. The term “alkyl” refers to a saturated, linear or branched hydrocarbon moiety, such as —CH 3 or —CH(CH 3 ) 2 . The term “alkenyl” refers to a linear or branched hydrocarbon moiety that contains at least one double bond, such as —CH═CH—CH 3 . The term “alkynyl” refers to a linear or branched hydrocarbon moiety that contains at least one triple bond, such as —C≡C—CH 3 . The term “cycloalkyl” refers to a saturated, cyclic hydrocarbon moiety, such as cyclohexyl. The term “cycloalkenyl” refers to a non-aromatic, cyclic hydrocarbon moiety that contains at least one double bond, such as cyclohexenyl. The term “heterocycloalkyl” refers to a saturated, cyclic moiety having at least one ring heteroatom (e.g., N, O, or S), such as 4-tetrahydropyranyl. The term “heterocycloalkenyl” refers to a non-aromatic, cyclic moiety having at least one ring heteroatom (e.g., N, O, or S) and at least one ring double bond, such as pyranyl. The term “aryl” refers to a hydrocarbon moiety having one or more aromatic rings. Examples of aryl moieties include phenyl (Ph), phenylene, naphthyl, naphthylene, pyrenyl, anthryl, and phenanthryl. The term “heteroaryl” refers to a moiety having one or more aromatic rings that contain at least one heteroatom (e.g., N, O, or S). Examples of heteroaryl moieties include furyl, furylene, fluorenyl, pyrrolyl, thienyl, oxazolyl, imidazolyl, thiazolyl, pyridyl, pyrimidinyl, quinazolinyl, quinolyl, isoquinolyl and indolyl.
Alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, aryl, and heteroaryl mentioned herein include both substituted and unsubstituted moieties, unless specified otherwise. Possible substituents on cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, aryl, and heteroaryl include, but are not limited to, C 1 -C 10 alkyl, C 2 -C 10 alkenyl, C 2 -C 10 alkynyl, C 3 -C 20 cycloalkyl, C 3 -C 20 cycloalkenyl, C 1 -C 20 heterocycloalkyl, C 1 -C 20 heterocycloalkenyl, C 1 -C 10 alkoxy, aryl, aryloxy, heteroaryl, heteroaryloxy, amino, C 1 -C 10 alkylamino, C 1 -C 20 dialkylamino, arylamino, diarylamino, C 1 -C 10 alkylsulfonamino, arylsulfonamino, C 1 -C 10 alkylimino, arylimino, C 1 -C 10 alkylsulfonimino, arylsulfonimino, hydroxyl, halo, thio, C 1 -C 10 alkylthio, arylthio, C 1 -C 10 alkylsulfonyl, arylsulfonyl, acylamino, aminoacyl, aminothioacyl, amidino, guanidine, ureido, cyano, nitro, nitroso, azido, acyl, thioacyl, acyloxy, carboxyl, and carboxylic ester. On the other hand, possible substituents on alkyl, alkenyl, or alkynyl include all of the above-recited substituents except C 1 -C 10 alkyl. Cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, aryl, and heteroaryl can also be fused with each other.
In another aspect, this invention features a method for treating cancer. The method includes administering to a subject in need thereof an effective amount of one or more indazole compounds of formula (I) or (II) shown above. An example of cancer that can be treated by the indazole compounds of this invention is lung cancer. The term “treating” or “treatment” refers to administering one or more indazole compounds to a subject, who has an above-described disease, a symptom of such a disease, or a predisposition toward such a disease, with the purpose to confer a therapeutic effect, e.g., to cure, relieve, alter, affect, ameliorate, or prevent the above-described disease, the symptom of it, or the predisposition toward it.
In addition, this invention encompasses a pharmaceutical composition that contains at least one of the above-mentioned indazole compounds and a pharmaceutically acceptable carrier.
The indazole compounds described above include the compounds themselves, as well as their salts, prodrugs, and solvates, if applicable. A salt, for example, can be formed between an anion and a positively charged group (e.g., amino) on a indazole compound. Suitable anions include chloride, bromide, iodide, sulfate, nitrate, phosphate, citrate, methanesulfonate, trifluoroacetate, acetate, malate, tosylate, tartrate, fumurate, glutamate, glucuronate, lactate, glutarate, and maleate. Likewise, a salt can also be formed between a cation and a negatively charged group (e.g., carboxylate) on a indazole compound. Suitable cations include sodium ion, potassium ion, magnesium ion, calcium ion, and an ammonium cation such as tetramethylammonium ion. The indazole compounds also include those salts containing quaternary nitrogen atoms. Examples of prodrugs include esters and other pharmaceutically acceptable derivatives, which, upon administration to a subject, are capable of providing active indazole compounds. A solvate refers to a complex formed between an active indazole compound and a pharmaceutically acceptable solvent. Examples of pharmaceutically acceptable solvents include water, ethanol, isopropanol, ethyl acetate, acetic acid, and ethanolamine.
Also within the scope of this invention is a composition containing one or more of the indazole compounds described above for use in treating cancer, and the use of such a composition for the manufacture of a medicament for the just-mentioned treatment.
The details of one or more embodiments of the invention are set forth in the description below. Other features, objects, and advantages of the invention will be apparent from the description and from the claims.
DETAILED DESCRIPTION
Shown below are 55 exemplary compounds of this invention:
The indazole compounds described above can be prepared by methods well known in the art. Examples 1-55 below provide detailed descriptions of how compounds 1-55 were actually prepared.
Scheme I shown below illustrates a typical synthetic route for synthesizing certain exemplary indazole compounds. R 2 and R 5 in this scheme can be those described in the Summary section above.
Specifically, as shown in Scheme I above, a substituted benzene containing a nitro group and a halo group can first react with a primary amine compound to form a secondary amine compound. This compound can then undergo a ring closure reaction between the nitro group and the secondary amino group to form an indazole compound of this invention.
An indazole compound synthesized above can be purified by a suitable method such as column chromatography, high-pressure liquid chromatography, or recrystallization.
Other indazole compounds can be prepared using other suitable starting materials through the above synthetic routes and others known in the art. The methods described above may also additionally include steps, either before or after the steps described specifically herein, to add or remove suitable protecting groups in order to ultimately allow synthesis of the indazole compounds. In addition, various synthetic steps may be performed in an alternate sequence or order to give the desired compounds. Synthetic chemistry transformations and protecting group methodologies (protection and deprotection) useful in synthesizing applicable indazole compounds are known in the art and include, for example, those described in R. Larock, Comprehensive Organic Transformations , VCH Publishers (1989); T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 2 nd Ed., John Wiley and Sons (1991); L. Fieser and M. Fieser, Fieser and Fieser's Reagents for Organic Synthesis , John Wiley and Sons (1994); and L. Paquette, ed., Encyclopedia of Reagents for Organic Synthesis , John Wiley and Sons (1995) and subsequent editions thereof.
The indazole compounds mentioned herein may contain a non-aromatic double bond and one or more asymmetric centers. Thus, they can occur as racemates and racemic mixtures, single enantiomers, individual diastereomers, diastereomeric mixtures, and cis- or trans-isomeric forms. All such isomeric forms are contemplated.
Also within the scope of this invention is a pharmaceutical composition containing at least one indazole compound described above and a pharmaceutical acceptable carrier. Further, this invention covers a method of administering an effective amount of one or more of the indazole compounds to a patient having cancer. “An effective amount” refers to the amount of an active indazole compound that is required to confer a therapeutic effect on the treated subject. Effective doses will vary, as recognized by those skilled in the art, depending on the types of diseases treated, route of administration, excipient usage, and the possibility of co-usage with other therapeutic treatment. For example, a daily dose of 5 mg/kg of compound 1 can be used reduce metastasis and a daily dose of 50 mg/kg can be used to inhibit tumor growth.
To practice the method of the present invention, a composition having one or more indazole compounds can be administered parenterally, orally, nasally, rectally, topically, or buccally. The term “parenteral” as used herein refers to subcutaneous, intracutaneous, intravenous, intramuscular, intraarticular, intraarterial, intrasynovial, intrasternal, intrathecal, intralesional, or intracranial injection, as well as any suitable infusion technique.
A sterile injectable composition can be a solution or suspension in a non-toxic parenterally acceptable diluent or solvent, such as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that can be employed are mannitol, water, Ringer's solution, and isotonic sodium chloride solution. In addition, fixed oils are conventionally employed as a solvent or suspending medium (e.g., synthetic mono- or diglycerides). Fatty acid, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions can also contain a long chain alcohol diluent or dispersant, carboxymethyl cellulose, or similar dispersing agents. Other commonly used surfactants such as Tweens or Spans or other similar emulsifying agents or bioavailability enhancers which are commonly used in the manufacture of pharmaceutically acceptable solid, liquid, or other dosage forms can also be used for the purpose of formulation.
A composition for oral administration can be any orally acceptable dosage form including capsules, tablets, emulsions and aqueous suspensions, dispersions, and solutions. In the case of tablets, commonly used carriers include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions or emulsions are administered orally, the active ingredient can be suspended or dissolved in an oily phase combined with emulsifying or suspending agents. If desired, certain sweetening, flavoring, or coloring agents can be added.
A nasal aerosol or inhalation composition can be prepared according to techniques well known in the art of pharmaceutical formulation. For example, such a composition can be prepared as a solution in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other solubilizing or dispersing agents known in the art.
A composition having one or more active indazole compounds can also be administered in the form of suppositories for rectal administration.
The carrier in the pharmaceutical composition must be “acceptable” in the sense that it is compatible with the active ingredient of the composition (and preferably, capable of stabilizing the active ingredient) and not deleterious to the subject to be treated. One or more solubilizing agents can be utilized as pharmaceutical excipients for delivery of an active indazole compound. Examples of other carriers include colloidal silicon oxide, magnesium stearate, cellulose, sodium lauryl sulfate, and D&C Yellow # 10.
The indazole compounds described above can be preliminarily screened for their efficacy in treating above-described diseases by in vitro and in vivo assays (see Examples 56 and 57 below) and then confirmed by clinic trials. Other methods will also be apparent to those of ordinary skill in the art.
The specific examples below are to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. Without further elaboration, it is believed that one skilled in the art can, based on the description herein, utilize the present invention to its fullest extent.
EXAMPLE 1
Preparation of Compound 1
methyl 2-(3,3-diphenylpropyl)-2H-indazole-6-carboxylate
A solution of dicyclohexylcarbodiimide (DCC, 0.95 g, 4.61 mmol, 1.2 equiv) in 10 mL of dichloromethane (DCM) was added dropwise to a stirred mixture of 4-bromomethyl-3-nitro-benzoic acid 1 (1.0 g, 3.84 mmol, 1.0 equiv) and 4-dimethylaminomethylpyridine (DMAP) (0.020 g, 0.19 mmol, 0.05 equiv) in 10 mL of dichloromethane-methanol (10%) at room temperature. The mixture was stirred for 6 hours to obtain 4-bromomethyl-3-nitro-benzoic acid methyl ester 2. Dicyclohexyl urea (DCU) thus obtained was removed by filtration and the solvent in the filtered solution was removed under vacuum. The residue was purified by column chromatography using hexane-ethyl acetate (15%) as an eluant to give ester 2 as a light yellow oil.
To a solution of ester 2 (0.91 g, 3.32 mmol, 1.0 equiv) in 10 mL of dichloromethane was added dropwise 3,3-diphenyl-propylamine (1.40 g, 6.64 mmol, 2.0 equiv). The mixture was stirred at room temperature for 8 hours. After the amine salt thus obtained was removed by filtration, the solvent in the filtered solution was removed under vacuum to give crude 4-[(3,3-diphenyl-propylamino)-methyl]-3-nitro-benzoic acid methyl ester 3. The crude product was purified by column chromatography using hexane-ethyl acetate (25%) to give ester 3 as a light brown oil.
4-[(3,3-diphenyl-propylamino)-methyl]-3-nitro-benzoic acid methyl ester 3 (0.81 g, 3.21 mmol) was dissolved in 10 ml of methanol and treated with ammonium formate (1.26 g, 20.02 mmol, 10 equiv) and palladium on carbon (162 mg, 20%). The mixture was stirred for 1 day at room temperature. After the mixture was then filtered through a small plug of Celite and washed with dichloromethane, the solvent was removed under vacuum to give a crude product. The crude product was purified by column chromatography using hexane-ethyl acetate (25%) to give compound 1,2-(3,3-diphenyl-propyl)-2H-indazole-6-carboxylic acid methyl ester, as a white solid.
1 H NMR (300 MHz, CDCl 3 ) δ 8.53 (s, 1H), 7.82 (s, 1H), 7.75˜7.72 (dd, J=8.7, 1.2 Hz, 1H), 7.69˜7.66 (dd, J=8.7, 0.5 Hz, 1H), 7.35˜7.20 (m, 10H), 4.41 (t, J=6.9 Hz, 2H), 3.97 (s, 3H), 3.88 (t, J=7.9 Hz, 1H), 2.87˜2.80 (q, J=7.2 Hz, 2H).
13 C NMR (75 MHz, CDCl3) δ 167.56, 148.13, 143.25, 128.68, 127.71, 126.61, 123.65, 123.27, 121.28, 121.18, 120.07, 52.36, 52.13, 48.12, 35.94; IR (cm-1, neat): 3236, 2948, 1713, 1601, 1443, 1269.
MS (EI): m/z 370 (M + ). Exact mass calculated for C 24 H 22 N 2 O 2 : m/z 370.1681 Found 370.1681.
EXAMPLES 2-55
Preparation of Compounds 2-55
Compounds 2-55 were prepared in a manner similar to that described in Example 1.
EXAMPLE 56
KIRA-ELISA Assay
This assay was performed in two microtiter plates. The first plate was used to culture an adherent cell line expressing the VEGF receptor 3 and to stimulate the receptor with a test compound. The second plate was used to capture the solubilized membrane receptor, which was then probed for phosphotyrosine content with phosphotyrosine-specific antibody.
Specifically, H928 cells (2×10 5 ) in 100 μl medium were added to each well in a flat-bottom 24-well culture plate and cultured overnight at 37° C. in 5% CO 2 . After the supernatants were removed, the cells were serum-starved for 24 hours. A medium containing a test compound was added into each well and the cell culture was incubated for 30 minutes before it was stimulated by recombinant VEGF-C for 15 minutes. After the supernatants were removed, 100 μl of a lysis buffer were added into each well to lyse the cells and solubilize the VEGFR3. The lysis buffer included 150 mM NaCl containing 50 mM Hepes (Genentech media prep), 0.5% Triton-X 100 (Genentech media prep), 0.01% thimerosol, 30 kIU/ml aprotinin (ICN Biochemicals, Aurora, Ohio), 1 mM 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride (AEBSF; ICN Biochemicals), and 2 mM sodium orthovanadate. The plate was then put on a plate shaker (Bellco Instruments Vineland, N.J.) and the substance in each well of the plate underwent mixing for 60 minutes at room temperature. While the cells were being solubilized, an ELISA microtiter plate (Nunc Maxisorp, Inter Med, Denmark) coated overnight at 4° C. with the affinity-purified polyclonal anti-VEGFR 3 (2.5 μg/ml in phosphate buffered saline (PBS), 100 μl/well) were decanted, tamped on a paper towel, and blocked with 150 μl/well block buffer (PBS containing 0.5% BSA and 0.01% thimerosol) for 60 minutes at room temperature with gentle agitation. The anti-VEGFR 3-coated plate was subsequently washed twice with a wash buffer (PBS containing 0.05% Tween 20 and 0.01% thimerosol). The lysate containing solubilized VEGFR 3 from the cell-culture microtiter well were transferred (85 μl/well) to the anti-VEGFR 3-coated ELISA plate and incubated for 2 hours at room temperature with gentle agitation. The unbound receptors were removed by washing with a wash buffer. 100 μl of biotinylated 4G10 (antiphosphotyrosine) diluted to 0.2 μg/ml in dilution buffer (PBS containing 0.5% BSA, 0.05% Tween 20, 5 mM EDTA, and 0.01% thimerosol) were added into each well. After incubation for 2 hours at room temperature, the plate were washed and 100 μl HRP-conjugated streptavidin (Zymed Laboratories, S. San Francisco, Calif.) diluted 1:2000 in dilution buffer will be further added. After the free avidin conjugate were washed away, 100 μl freshly prepared substrate solution (tetramethyl benzidine, TMB) was added to each well. The reaction was allowed to proceed for 10 minutes and the color development was stopped by the addition of 100 μl/well 1.0 M H 3 PO 4 . The absorbance at 450 nm and the absorbance at a reference wavelength of 650 nm (A 450/650 ) were measured using an ELISA reader.
The inhibition efficacy of each test compound is expressed as an inhibition percentage calculated according to the following formula: 1-[(C−A)/(B−A)]. In this formula, A is the basal amount of phosphotyrosine detected in a blank control, B is the amount of phosphotyrosine detected with VEGF-C only, and C is the amount of phosphotyrosine detected with a test compound and VEGF-C.
Among the 55 compounds, 50 compounds (i.e., compounds 1-22, 24-30, 32, 34-39, 41-50, and 52-55) were tested. Unexpectedly, 46 of the test compounds showed more than 20% inhibition of VEGF receptor 3. Among the 46 compounds, 24 showed more than 50% inhibition, and 5 showed more than 75% inhibition.
EXAMPLE 57
In Vivo Assay
Compound 1 was tested for its efficacy in inhibiting tumor growth on murine tumor xenografts. Briefly, VEGF-C overexpressing H928 cells or LLC were trypsinized, washed with PBS and resuspended in PBS. The concentration was adjusted to 3×10 6 cells/100 μl in PBS. The cell suspension was then injected subcutaneously into the right abdominal wall of C57BL/6J mice (7-8 week old, one tumor per mice). When the diameter of implanted tumor cells reached 5 mm, compound 1 or vehicle was administered intraperitoneally once daily. The length and width of the tumor was measured every 2-3 days by using a caliper. The tumor volume was then calculated as follows: volume=length×width 2 ×0.52. Student's t test was used to compare tumor volumes, with P<0.05 being considered significant. After 8 weeks, the mice were sacrificed in a CO 2 chamber and the tumors were collected. Lungs and lymph nodes were removed. For tumor metastasis assay (Quantitative analysis of lung metastatic nodules), the number of lung tumor nodule was counted under a dissecting microscope. Compound 2 was tested by the same procedure.
OTHER EMBODIMENTS
All of the features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.
From the above description, one skilled in the art can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Thus, other embodiments are also within the scope of the following claims.
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This invention relates to indazole compounds of formula (I) or (II) shown below. Each variable in formula (I) or (II) is defined in the specification. These compounds can be used to treat cancer.
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BACKGROUND OF THE INVENTION
This invention relates generally to methods and system for filtering and binarizing images, and, more particularly to binarizing images in the presence of specular noise, where the information of interest in the image is contained in edges.
Edges contain a significant portion of the information in an image. In some images, such as images containing addresses (text) and bar codes typical of address labels in postal items and packages, edges contain almost all the information. Recovering that information in the presence of specular noise can be difficult. An example of an application where those conditions occur is the recovery of address and bar code information in mail pieces with high gloss wrappings. The specular reflection caused by the high gloss wrappings introduces noise in the image and renders the detection difficult. Typically, OCR systems are used to recover the information. Binarizing in OCR systems, as described by Wu and Manmatha (V. Wu, R. Manmatha, Document Image Clean Up and Binarization, available at http://citeseer.nj.nec.com/43792.html) is traditionally performed with a multi directional global threshold method. Under such a binarization method, the results obtained when the image is obscured by specular noise can be difficult to interpret.
Many difficulties are encountered in recovering the information from images in the presence of specular noise, such as the noise caused by transmission through high gloss wrappings, when global binarization methods are used.
Several adaptive binarization methods have been proposed (see, for example, Ø. D. Trier and T. Taxt, Evaluation of binarization methods for document images, available at http://citeseer.nj.nec.com/trier95evaluation.html, also a short version published in IEEE Transaction on Pattern Analysis and Machine Intelligence, 17, pp. 312–315, 1995). Such proposed adaptive binarization algorithms are in general complex, difficult to implement, and, therefore, have not seen widespread use.
SUMMARY OF THE INVENTION
In order to render information contained in images more recoverable in the presence of specular noise, the present invention discloses a system and method to binarize the image in the presence of specular noise. The method of this invention comprises the steps of applying a dynamic range reducing filter to the digitized image values, obtaining a range reduced image; applying an edge detecting filter to the range reduced image, obtaining a filtered image; and then, adaptively binarizing the digitized image utilizing the corresponding filtered image to obtain an adaptive threshold.
In one embodiment of this invention, the dynamic range reducing filter is a base ten logarithm of one plus the digitized image pixel value. In another embodiment of this invention, the edge detecting filter is a Marr-Hildreth filter times a constant.
The method of this invention can be implemented by a system comprising means for calculating the range reduced image, means for calculating the filtered image and means for determining the binarization. For example, a dedicated processor and supporting memory could be used to implement the method of this invention. In another embodiment, a digital signal processor or a general purpose processor and supporting memory could be used to implement the method of this invention. In still another embodiment, any of the previously described processor and memory systems could be used to implement the filtering operation and a dedicated binarization circuit could be used to implement the binarization operation.
For a better understanding of the present invention reference is made to the accompanying drawings and detailed description and its scope will be pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A depicts an original image under the presence of noise;
FIG. 1B depicts the binarized image obtained using a global binarization algorithm;
FIG. 1C depicts the binarized image obtained using an embodiment of a binarization algorithm of this invention;
FIG. 2A depicts a second original image under the presence of noise;
FIG. 2B depicts the binarized image, corresponding to the second image, using a global binarization algorithm;
FIG. 2C depicts the binarized image, corresponding to the second image, obtained using an embodiment of a binarization algorithm of this invention;
FIG. 3 is a graphical representation of the pixels from an image, depicting the locations at which a filter as used in an embodiment of this invention is applied;
FIG. 4 is a flow chart representative of an embodiment of the method of this invention;
FIG. 5 is a flow chart representative of a detailed embodiment of the method of this invention;
FIG. 6 is a block diagram representative of an embodiment of the system of this invention; and
FIG. 7 is a block diagram representative of another embodiment of the system of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A system and method for binarizing an image in the presence of specular noise, that renders information contained in images more detectable in the presence of noise, is disclosed.
In order to better understand the difficulties encountered in past attempts to apply global binarization methods as described above, reference is made to FIGS. 1A , 1 B, 2 A, and 2 B of the drawings. More specifically, FIG. 1A depicts an original image under the presence of specular noise. FIG. 1B depicts the binarized image obtained from the image of FIG. 1A using a global binarization algorithm. Similarly, FIG. 2A depicts another original image under the presence of noise. FIG. 2B depicts the binarized image obtained from the image of FIG. 2A using a global binarization algorithm.
A graphical representation of the pixels from an image 1 (where image 1 contains only bar codes), depicting the locations at which an embodiment of a filter as used in this invention is applied, is shown in FIG. 3 . Referring to FIG. 3 , for every point in the digitized image 10 , there is a corresponding pixel value 5, p i,j . Every pixel value 5, p i,j , has a neighborhood of surrounding pixel values 15. Exceptions have to the made for the pixel values at the borders of the image. The methods for treating elements at the boundary are well known to those skilled in the art.
A flow chart representative of an embodiment of the method of this invention is shown in FIG. 4 . Referring to FIG. 4 , a dynamic range reducing filter or transformation is applied to each pixel value 5, p i,j , (step 20 , FIG. 4 ) obtaining a range reduced image with range reduced image pixel values, (p i,j ) reduced . If the dynamic range reducing filter or transformation is given by R(x), the range reduced image is given by
( p i,j ) reduced =R ( p i,j )
An edge detecting filter is applied to each pixel value of the range reduced image, (p i,j ) reduced , and to surrounding pixels of the range reduced image (step 30 , FIG. 4 ). (Exemplary embodiments of dynamic range reducing filters and edge detecting filters are described in J. S. Lim, Two Dimensional Signal and Image Processing , ISBN 0-13-935322-4, pp. 453–59 and pp. 476–94, respectively.) A filtered image, (p i,j ) filtered , is obtained by applying the edge detecting filter to the range reduced image. If the edge detecting filter is given a by h i,j , where the index j extends from −n to +n, and, similarly, the index i extends from −n to +n, the filtered image pixel values are given by
(
p
i
,
j
)
filtered
=
∑
k
=
-
n
n
∑
l
=
-
n
n
h
k
+
n
,
l
+
n
(
p
i
+
k
,
j
+
l
)
reduced
Using the filtered image pixel values, an adaptive threshold, T i,j is obtained (step 40 , FIG. 4 ). The digitized image pixel value is then compared to the threshold, T i,j (step 50 , FIG. 4 ). If the pixel value is greater than or equal to the threshold T i,j , the binarized pixel value is set equal to 1 (step 60 , FIG. 4 ). If the pixel value is less than the threshold, the binarized pixel value is set equal to zero (step 70 , FIG. 4 ).
It should be apparent that other embodiments of the threshold comparison step could be used. The binarized pixel value could be set to 1 when the pixel value is greater than the threshold T i,j , and to zero otherwise. Similarly, the binarized pixel value could be inverted (applying the logical NOT function) resulting in the logical opposite of the embodiment described above.
In a specific embodiment of this invention, the dynamic range reducing filter is a base ten logarithm of one plus the digitized image pixel value. In that embodiment,
( p i,j ) reduced =log 10 (1+p i,j )
In another specific embodiment, the edge detection filter used is a constant multiple of a Marr-Hildreth edge detector. A Marr-Hildreth edge detector is a filter generated by a Laplacian of a Gaussian and, for a 2n +1 by 2n +1 kernel, the filter, h i,j , is given by
h i , j = ⅇ - ( ( i - n ) 2 + ( j - n ) 2 ) / 2 π σ 2 π σ 2 [ 1 π ( i - n σ ) 2 + 1 π ( j - n σ ) 2 - 2 ]
In one embodiment, the filter used is sixty times a Marr-Hildreth filter with a σ of 1.5, and is given by
h
i
,
j
=
60
ⅇ
-
(
(
i
-
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)
2
+
(
j
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4
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5
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π
2.25
[
1
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(
i
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2
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]
A flow chart representative of a detailed embodiment of the method of this invention is shown in FIG. 5 wherein identical steps to those of FIG. 4 are represented by blocks with the same reference numbers. Referring to FIG. 5 , the threshold is selected equal to the filtered image pixel value, (p i,j ) filtered (step 45 , FIG. 5 ).
The method of this invention can be implemented by a system 100 ( FIG. 6 ) comprising means for calculating the filtered image and means for determining the binarization. Referring to FIG. 6 , a processor 110 and supporting memory 130 could be used to implement the method of this invention. Processor 110 can be a dedicated processor, or a digital signal processor, or a general purpose processor and supporting memory 130 could be any computer readable memory. The digitized image values are provided as input by input means 120 . It should be apparent that input means 120 could be any input means known in the art. Other memory 140 could be used for housekeeping and other functions. The processor and memory systems and the code to cause the processor to implement the methods of this invention constitute means for applying a dynamic range reducing filter to the digitized image values, means for applying the edge detecting filter to the reduced range image and means for binarizing the digitized image. In another embodiment, shown in FIG. 7 , wherein identical blocks as those shown in FIG. 6 are shown as blocks with the same block numbers, the previously described processor 110 and supporting memory 160 could be used to implement the filtering operations and the determining of the adaptive threshold and a dedicated binarization circuit 170 could be used to implement the binarization operation. For example, the operation of comparing the digitized image value to the filtered image pixel value at each pixel could be implemented by means of digital circuits.
The results obtained by applying the method of this invention to images in the presence of specular noise, such as the noise caused by viewing the image through a high gloss wrapping, can be seen from FIGS. 1A , 1 C, 2 A, 2 C. FIG. 1A depicts an original image under the presence of noise. FIG. 1C depicts the binarized image obtained from the image of FIG. 1A using the method and system of this invention described above in which a range reducing filter equal to a base ten logarithm of one plus the digitized image pixel value and an edge detecting filter equal to sixty times a Marr-Hildreth (Laplacian of Gaussians) filter with a σ of 1.5 pixels are used. Similarly, FIG. 2A depicts another original image under the presence of noise. FIG. 2C depicts the binarized image obtained from the image of FIG. 2A using the method and system of this invention described above.
While the detailed embodiment of this invention has been described in terms of a filter that is a multiple of a Marr-Hildreth filter it should be apparent that any edge detecting filter could be used. Similarly, while the detailed embodiment of this invention has been described in terms of a range reducing filter that is a base ten logarithm of one plus the digitized image pixel value, it should be apparent that any dynamic range reducing filter can be used. Also, similarly, while the detailed embodiment of this invention has been described in terms of an adaptive threshold equal to the filtered image pixel value, it should be apparent that other functions of the filtered image pixel values could be used.
In general, the techniques described above may be implemented, for example, in hardware, software, firmware, or any combination thereof. The techniques described above may be implemented in one or more computer programs executing on a programmable computer including a processor, a storage medium readable by the processor (including, for example, volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. Program code may be applied to data entered using the input device to perform the functions described and to generate output information. The output information may be applied to one or more output devices.
Elements and components described herein may be further divided into additional components or joined together to form fewer components for performing the same functions.
Each computer program within the scope of the claims below may be implemented in any programming language, such as assembly language, machine language, a high-level procedural programming language, or an object-oriented programming language. The programming language may be a compiled or interpreted programming language.
Each computer program may be implemented in a computer program product tangibly embodied in a computer-usable storage device for execution by a computer processor. Method steps of the invention may be performed by a computer processor executing a program tangibly embodied on a computer-readable medium to perform functions of the invention by operating on input and generating output.
Common forms of computer-usable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, a CDROM, any other optical medium, punched cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave, or any other medium from which a computer can read.
Although the invention has been described with respect to various embodiments, it should be realized this invention is also capable of a wide variety of further and other embodiments within the spirit and scope of the appended claims.
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In order to render information contained in images more detectable in the presence of noise, the present invention discloses a system and method to binarize the images in the presence of noise. The method of this invention comprises the steps of applying a dynamic range reducing filter to the digitized image values, obtaining a range reduced image; applying an edge detecting filter to the range reduced image, obtaining a filtered image; and then, adaptively binarizing the digitized image utilizing the corresponding filtered image to obtain an adaptive threshold.
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BACKGROUND
This disclosure relates to computer networks in general, and in particular, to apparatus and methods for efficiently and automatically detecting functional defects and performance bottlenecks in home and small business computer networks.
Although most network devices are subject to some quality assurance (QA) testing before being shipped to customers, their relatively high complexities, coupled with the almost unlimited number of ways in which they can be integrated into networks by users, makes it relatively difficult for the developers of the devices to ensure that they have been exhaustively tested, especially under urgent time-to-market pressures. Further, each of the myriad of possible user applications of the devices takes time to simulate, setup, generate and verify.
Thus, when end-users deploy a particular network device within their network, they often discover that the device does not function according to their expectations in terms of functional behavior and/or performance, and this disappointment can generate a large number of requests for technical support. Moreover, during manufacturer-provided technical support sessions, it is often difficult for the remotely located technical support personnel to understand and replicate exactly the particular end-user application so as to provide the most effective customer support, especially if the user is not technically sophisticated, which is often the case for home users and small business entities lacking information technology (IT) expertise. This situation can result in a large volume of customer complaints, and in many cases, issuance of unnecessary return-to-manufacturer authorizations (RMAs) by the manufacturer of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a typical home or small business computer network incorporating a number of network devices;
FIG. 2 is a functional block diagram of a pair of connected, related network devices, including a Device Testing Doctor (DTD) and a Device Under Test (DUT) in accordance with an example embodiment of the present disclosure;
FIG. 3 is a process flow diagram of an example embodiment of method for the automated testing of a DUT network device for functional defects by a DTD in accordance with the present disclosure; and,
FIG. 4 is a process flow diagram of an example embodiment of method for the automated testing of a DUT network device for performance bottlenecks by a DTD in accordance with the present invention.
DESCRIPTION
Overview
In accordance with this disclosure, methods and apparatus are provided for the automated testing of computer network devices that enable in-depth functional and performance testing by inserting traffic-pattern generation codes and functional behavior testing codes into a related pair of the devices of the network, wherein the inserted codes comprise standard configuration template files, standard behavior output template files, and auto testing program and/or script files for measuring correct network behavior, as well as network performance bottleneck discovery codes that measure each software component's utilization rate of the CPU of the device under test for discovering the source of network bottlenecks.
DESCRIPTION OF EXAMPLE EMBODIMENTS
FIG. 1 illustrates a typical home or small business computer network 10 incorporating a number of network devices, including servers 12 , clients 14 (both wired and wireless), switches 16 , routers 18 and a wireless access point (AP) 20 , and at least a portion of which is routed through the internet 22 .
FIG. 2 is a functional block diagram of an example embodiment of an apparatus operable to automatically detect functional defects and performance bottlenecks in the network devices of the network 10 of FIG. 1 in accordance with the present disclosure. The apparatus comprises a pair of interconnected and “related” network devices, including a “Device Testing Doctor” (DTD) network device 100 , and a “Device Under Test” (DUT) network device 200 . Any two interconnected network devices that are “related” to each other, i.e., are in the same “family” of device types, may respectively serve as both the DUT and the DTD, in a manner analogous to the relationship between a patient and a doctor, but with the advantageous distinction that the DUT and DTD can exchange the doctor/patient roles with each other. For example, in a typical home or small business network such as that illustrated in FIG. 1 , the two related devices can comprise a pair of the routers 18 , a pair of the switches 16 , or a router 18 and switch 16 , that are connected to each other within the network 10 , in either a wired or a wireless manner. Further, to qualify as either a DTD 100 or a DUT 200 in accordance with the present disclosure, the network device must, as a minimum, include a programmable CPU and a memory device of some type.
Most network devices, such as switches 16 and routers 18 , incorporate both a CPU and a memory device of some type, e.g., RAM and/or ROM. Thus, at the cost of only a minor increase in the code size of its memory, a network device that is augmented to serve as either a DTD 100 or a DUT 200 can be made capable of generating standard network traffics and transmitting them to any related DUT, monitoring those traffics, and measuring the correctness of the DUT's output in accordance with a standard-behavior-output template, and vice-versa. Accordingly, if a DUT 200 under test by a DTD 100 either malfunctions and/or is the source of a performance bottleneck, the device detecting the malfunction, which may be either the DTD or the DUT itself, can be programmed to, upon the detection of an anomaly, proactively send warning and/or advisory messages, either in real-time, e.g. via the network 10 and/or the internet 22 , or time-delayed, e.g., via e-mails, to the user, an IT administrator, and/or to remotely located tech support personnel situated at, e.g., the device manufacturer's site, that includes system log information regarding the current, specific system configuration and the nature of the problem detected, for a rapid diagnosis and cure of the problem.
To achieve this desirable end, additional code must be provisioned within both the DTD 100 and the DUT 200 , and this may be made entirely resident in the respective memories of the devices (i.e., via firmware), partially resident, or entirely uploaded into the respective memories of the two devices from, e.g., a local hard drive or CD, or even remotely, via the network 10 and/or the internet 22 . The additional testing code required is of three types: 1) Possible network device configurations that can be loaded via configuration files (i=1, . . . N) into the DUT 200 ; 2) possible traffic patterns that can be generated from the DTD 100 or other traffic sources to the DTD and DUT, such as from a server 12 or client 14 connected to the DTD and DUT; and, 3) one or more standard-behavior-output templates that are specific to detecting device functional defects and network bottlenecks.
As those of skill in this art will appreciate, a “device configuration file” is one that contains the definition of a possible network configuration in a network device, e.g., the DUT. The file format can be a simple text file. For example, each line can simply contain a keyword and one or more arguments of a particular network configuration option, e.g., “FIREWALL BLOCK ALL PING TRAFFICS”).
A “standard network traffic pattern file” may comprise a simple script file that contains executable commands to the network device for creating the appropriate testing traffic patterns, e.g., “PING IP_Address [of the network device to be tested] time_duration.”
A “standard-behavior-output template file” contains the definitions of the correct behavior outputs associated with a particular device configuration file and a standard network traffic pattern file, and is thus adapted for detecting network device functional defects and bottlenecks. By comparing the traffic behavior of the DUT to the associated standard-behavior-output template file, it can be readily determined whether the DUT is functioning correctly when it programmed with a given configuration and handling a standard network traffic pattern, e.g., “No PING TRAFFICS PASS-THROUGH FIREWALL.” However, if a “PING TRAFFICS PASS-THROUGH FIREWALL” is observed, a defect will be detected in the network device under test that is not functioning correctly according to the instructions of the particular device configuration file.
As illustrated in FIG. 2 , the great majority of possible network device test cases can be decomposed into a related, interconnected DTD 100 and DUT 200 pair. Additionally, as will be appreciated by those of skill in the art, in most instances, once the initial network device configuration setup has been done in a real user environment, the device configuration will typically remain in the device without changing for relatively long periods of time, i.e., until the next modification of the network, e.g., by the addition or removal of devices.
The functional behavior defect and performance bottleneck testing and detection operations or processes are illustrated in the process flow diagrams of FIGS. 3 and 4 , respectively, and as may be seen, the two procedures are very similar to each other. During the iterative testing cycles of each, the test cases are determined by two key factors, the possible DUT 200 configurations that are loaded via the configuration files (i=1, . . . N) into the DUT, and the possible resulting traffic patterns that can be generated from the DTD 100 (or from other traffic sources) to the DTD and DUT, such as from a server 12 or a client 14 connected to the DTD-DUT pair. As further illustrated in FIGS. 3 and 4 , the functional behavior defect and performance bottleneck detection can be classified into two types of detection or discovery paradigms, viz., “auto-” or self-detection, which is effected by the DUT 200 itself (e.g., a software component is causing a CPU of the DUT to function anomalously), and detection effected by the measurements made by the DTD 100 (e.g., a firewall malfunction, with an impermissible passing of secured traffic from a secured traffic source). In each case, either the DTD 100 or the DUT 200 itself compares the output of the DUT in response to the traffic patterns input to the DUT to the appropriate standard-behavior-output templates respectively stored in (or temporarily uploaded to) the respective memories of the two devices to determine whether a device defect or network bottleneck exists.
In FIG. 3 , the functional defect testing procedure begins at step S 1 , in which a configuration file i (where i=1 2, . . . N) may be loaded from the DTD 100 to the DUT 200 , or alternatively, from a server 12 or client 14 to both the DTD and DUT, which again, may be initiated either on a pre-programmed, periodic basis, i.e., fully automatically, or alternatively, on an elective basis, at a user's specific command (and which can be effected either remotely or locally), at the beginning of the test. As discussed above, the initial configuration of the DUT is typically fixed or static for most real user situations before testing begins, and the testing procedure can commence using the initial DUT configuration as the initial configuration file (i=1), and if it develops that the DUT is configured incorrectly, the testing procedure will reveal this.
At step S 2 of the functional defect testing procedure, a standard traffic input pattern j (where j=1, 2, . . . M) is supplied to the DUT 200 , again either from the DTD 100 , or to both the DTD and the DUT from a server 12 or client device 14 under the command of a user, either remotely or locally.
At step 3 , a functional defect in the DUT 200 may be self-detected by the DUT, or in some cases, by the DTD 100 using the DUT output that is fed back to the DTD via the feedback connection illustrated in FIG. 2 . In either case, the DUT or DTD that detects the defect may be programmed to send an appropriate warning or advisory message and a log or other type of report of the nature of the defect detected to the user and/or to appropriate technical support personnel, on either a real-time or a time-delayed basis, as discussed above. As those of skill in the art will appreciate, for real traffic that is input to the DUT 200 during actual use of the network, the DUT 200 can perform a limited amount of self-detection of functional defects by comparing the actual traffic input pattern with a standard traffic pattern and associated standard-behavior-output template stored in its memory, say pattern j, at step 3 of FIG. 3 , but the full benefit of the testing method and apparatus is obtained when the related DTD and DUT are working in cooperation with each other, as discussed above.
At step S 4 of the test, a check is made as to whether all of the traffic patterns j, where j=1 to M, have been tested for a particular configuration file i. If not, then at step S 5 , the number of the traffic pattern j is incremented by 1, and the process then loops back to step S 2 , where the next, or j+1th traffic pattern is then input to the DUT 200 , and this procedure is reiterated until all of the traffic patterns j=1 to M have been tested for the particular configuration file i. When all M traffic patterns have been processed by the DUT 200 for the configuration file i, which is determined at step S 5 , then the number of the configuration file is incremented by 1 to the next, or i+1th configuration file at step S 6 , and the above procedure is then repeated for the i+1th configuration file. The functional defect testing procedure continues iteratively in this manner until each of the N configuration files has been tested with each of the M traffic pattern files. When this is done, the test is finished, and, optionally, if no functional defects have been detected during the test, the DTD 100 or the DUT 200 can be provisioned to send a “system normal” log or report to the user and/or appropriate technical support personnel to that effect, in the same manner as a defect is reported above.
The flow of the performance bottleneck testing and detection procedure is illustrated in FIG. 4 , and as may be seen by a comparison to FIG. 3 , is very similar to that implemented for the detection of a DUT 200 functional defect. As illustrated in FIG. 4 , the functional defect testing procedure begins at step S 1 , in which a configuration file i (where i=1 2, . . . N) is automatically loaded from the DTD 100 , or alternatively, to both the DTD 100 and the DUT from a server 12 or a client 14 on the network 10 immediately prior to the testing operation, either automatically, or electively, at a user's command, and which can be effected either remotely or locally, at the beginning of the test. As discussed above, the initial DUT configuration is typically already set and static for most real user situations before testing begins, and the testing procedure can begin using this as the initial device configuration file (i.e., i=1).
At step S 2 , a standard traffic input pattern j (where j=1, 2, . . . M) is supplied to the DUT 200 from the DTD 100 , or alternatively, from a server 12 or a client 14 device under the user's command, either remotely or locally, to both the DTD and the DUT.
At step S 3 , the DUT 200 itself typically determines whether the overall utilization rate of its CPU is exceeding the normal threshold for the particular traffic input pattern j (j=1, 2, . . . M). If it is, i.e., if a bottleneck is self-detected by the DUT 200 , or in some cases, by the DTD 100 at step 3 , the DUT and the DTD are programmed to send an appropriate advisory message and a log or other type of report of the software component's utilization rate of the DUT's CPU, i.e., a bottleneck, to the user and/or appropriate technical support personnel, on either a real-time or a time-delayed basis, as discussed above. Further, as discussed above, for real traffic input to the DUT during actual use of the network, the DUT 200 can perform a limited amount of bottleneck self-detection by matching the actual input pattern with a standard traffic pattern j and associated standard-behavior-output CPU usage template associated with the standard traffic pattern stored in its memory.
At step S 4 of the test, a check is made as to whether all of the traffic patterns j, where j=1 to M, have been tested for a particular configuration file i. If not, then at step S 5 , the number of the traffic pattern j is incremented by 1, and the process then loops back to step S 2 , where the next, or j+1th traffic pattern is then input to the DUT 200 , and this procedure is reiterated until all of the traffic patterns j=1 to M have been tested for the particular configuration file i. When all M traffic patterns have been processed by the DUT 200 for the configuration file i, which is determined at step S 5 , then the number of the configuration file is incremented by 1 to the next, or i+1th configuration file at step S 6 , and the above procedure is then repeated for the DUT configured with the i+1th configuration file. The functional defect testing procedure continues iteratively in this manner until each of the N configuration files has been tested with each of the M traffic pattern files. When this is done, the test is finished, and, optionally, if no bottlenecks have been detected in the DUT during the test, the DTD 100 or the DUT 200 can be provisioned to send a “system normal” log or report to the user and/or appropriate technical support personnel to that effect, in the same manner as a “system normal” log is reported above.
As those of skill in the art will by now appreciate, the apparatus and methods disclosed herein provide a unique, advantageous mechanism by which defects and performance bottlenecks in a network DUT 200 are automatically detected and identified using a related DTD 100 in combination with the DUT. The DTD-DUT pair can be deployed in either a manufacturer's testing (QA) environment or at a customer site during troubleshooting and diagnostics activities. The universality of the DTD-DUT pairing thus enables it to be deployed in multiple environments and under multiple configurable conditions.
It should be understood that the invention can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is therefore not intended to be exhaustive nor to limit the invention to the precise form disclosed. It should be understood that the invention can be practiced with modification and alteration and that the invention be limited only by the appended claims and the functional equivalents thereof.
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A network device, such as a router or switch, has a CPU and a memory operable to receive, store and output computer code. The code includes device configuration files, traffic pattern files, and standard-behavior-output template files adapted for detecting network device functional defects and bottlenecks. The device is operable in a testing mode to act as either a Device Testing Doctor (DTD) or a Device Under Test (DUT), in which it loads into or accepts from a related, interconnected and similarly configured and operable network device selected ones of the device configurations, transmits to or receives from the other device selected ones of the input traffic patterns, compares its own output or that of the other device in response to the input traffic pattern with selected ones of the standard-behavior-output templates, and detects a network device defect or bottleneck in itself or in the other device based on the comparison.
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BACKGROUND OF THE INVENTION
1. Field of Use
This invention relates generally to self-propelled steerable apparatus for removing material from the surface of a confined area and for pumping it to another location for disposition.
In particular, it relates to such apparatus which is especially well-adapted, for example, to clean sludge from the bottom of large liquid storage tanks, such as chemical or oil tanks, but could have other applications, such as cleaning any container or confined area having a solid rigid bottom or floor made of metal, concrete, plastic or the like.
2. Description of the Prior Art
My U.S. Pat. No. 5,093,949, issued Mar. 10, 1992, discloses self-propelled steerable sludge cleaning apparatus for cleaning sludge from the bottom of large liquid storage tanks. That apparatus, which had motor-driven crawler tracks and was able to move across the bottom of the tank along desired paths in accordance with a computer program, employed a horizontally disposed rotatable motor-driven auger for delivering sludge through a horizontal center-feed pipe to a motor-driven pump for subsequent disposal elsewhere. The auger had oppositely-wound helical auger flights at opposite ends and fed the sludge to the center-feed pipe located near the center of the auger. The motor-driven crawler tracks and associated components were relatively large and heavy and required a separate drive motor and associated controls to effect propulsion and steering.
My U.S. Pat. No. 4,574,501, issued Mar. 11, 1986, discloses underwater dredging apparatus of the crater sink type for dredging fluid material such as sand from an underwater area. That apparatus, which was stationary and positioned at a fixed location beneath a body of water by means of a crane, employed a horizontally disposed rotatable motor-driven auger for delivering sand through a vertical pipe to a motor-driven pump for subsequent disposal elsewhere. The auger had oppositely-wound helical auger flights at opposite ends and the vertical pipe was located near the center of the auger. That apparatus was incapable of self-propulsion to other locations.
Each of my prior art machines is well-adapted for its intended purpose but it is desirable to provide an improved apparatus for removing material from a confined area and which employs a horizontally-disposed motor-driven auger for supplying material to a motor-driven pump, such improved apparatus being self-propelled, steerable, more compact and less complex than prior art apparatus.
Heretofore, it was common practice in tank cleaning operations to decant the liquid in the tank into another container, to de-gas the tank to remove noxious vapors, and admit men into the tank through an access opening, such as a man-way in the side of the tank, with buckets and shovels to remove the sludge or sediment accumulated at the bottom of the tank. However, safety requirements aimed at limiting the exposure of working personnel to noxious vapors and liquids contained the tank are becoming more restrictive and expensive as time goes on. Therefore, it is desirable to eliminate the need for personnel to enter the tank and to limit the time clean-up personnel are exposed to the atmosphere within the tank while installing or removing automated cleaning equipment in the tank.
Furthermore, the need to decant the tank to be cleaned, as mentioned above, means that the tank must be taken out of service and this has very expensive consequences. For example, the liquid must be placed in another compatible container and tanks are very expensive. Furthermore, the tank to be cleaned is taken out of service and this is another expense. Also, an out-of-service tank could slow down or even stop an industrial process, resulting in a very expensive production cut-back.
SUMMARY OF THE PRESENT INVENTION
The present invention provides improved self-propelled, steerable apparatus for removing material from the surface of a confined area for disposition elsewhere. The material may, for example, take the form of sludge which has settled at the bottom of a liquid storage tank such as a chemical or oil tank or the like.
The improved apparatus generally comprises a support frame or platform having top and rear walls; a horizontally disposed motor-driven rotatable auger beneath the platform; a motor-driven dredge or sludge pump mounted on the platform; and remotely operable steering means mounted on the platform.
The auger provides two functions. First, the auger cooperates with the walls of the support frame to define a passage in which sludge material can collect and be acted upon and moved by the rotating auger to the sludge pump. Second, the auger engages the floor of the confined area and its rotation propels the apparatus across the floor. Forward motion of the apparatus across the floor is restrained by a back-haul cable or tether which is periodically paid out by a remotely controllable winch in small increments to allow the apparatus to move forward a short distance, whereupon the back-haul cable prevents further forward motion while the auger continues to rotate and deliver sludge material to the sludge pump. Means are provided to supply by-pass liquid from a suitable source (and compatible with the sludge) to the aforesaid space to make the sludge more soluble and easier to handle by the auger and pump.
The dredge pump has a sludge inlet port communicating with the aforesaid space. The dredge pump also has a sludge discharge port connectable to a sludge discharge hose for disposing of the sludge exteriorly of the tank.
The remotely operable steering means comprises an elongated arcuately movable steering arm which extends rearwardly from the platform. One end of the steering arm is pivotally connected to the platform and a rotatable tail wheel is mounted at its other end. An extendible/retractable hydraulic ram is connected between the platform and the steering arm and is operable to pivotally move the steering arm and the tail wheel thereon to effect steering of the apparatus. The afore-mentioned back-haul cable or tether is connected to the tail end of the steering arm. During operation the apparatus is then lowered into a layer of sludge on the floor of a tank to be cleaned so that the edge of the auger and the tail wheel rest on the tank floor. Assuming that there is a small amount of slack in the back-haul cable, rotation of the auger then causes the apparatus to move across the tank floor in a direction transverse to the auger axis until it is stopped by the back-haul cable. With the apparatus at rest, sludge already in the aforesaid space between the platform and auger (and mixed with by-pass fluid to make it more fluid) is moved by the still-rotating auger toward the discharge end of the auger into the dredge pump and from thence through the discharge hose for final disposition. If the sludge is especially fluid, it can continue to flow into the space even though the apparatus is stationary. The back-haul cable, which is attached to the selectively controllable winch, controls the distance the apparatus can move across the tank floor. Paying out or reeling in the back-haul cable can control the position of the apparatus on the tank floor. Counter-torque movement of the platform in response to rotor torque forces the tail wheel firmly against the tank floor to achieve effective steering.
The auger can take various forms and the form chosen determines the behavior of the apparatus. If the auger has a single helical spiral, it rotates to feed sludge to an end outlet located at one end of the platform and connected to the sludge pump. In such an arrangement auger action tends to cause the apparatus to move or drift slightly in the axial direction of the auger but such drift is overcome by positioning the tail wheel so that it is at the "dynamic center" of the apparatus. The steering arm can be positioned either by pre-shaping the steering arm or by operating the steering cylinder to overcome the tendency of the apparatus to drift. Furthermore, the steering means enables the apparatus to be steered along arcuate paths across the tank floor.
If the auger has oppositely formed helical flights at opposite ends, the auger can feed sludge to a center outlet on the platform and the apparatus has no tendency to drift.
Apparatus in accordance with the present invention offers several advantages over the prior art. For example, it is constructed of a minimum number of components. The components of the apparatus are easily assembled and disassembled and can be assembled inside a tank which has a "man way" or access opening smaller than the fully assembled apparatus.
It can be quickly assembled and disassembled, thereby reducing the time operating personnel are exposed to toxic or noxious vapors near the man-way.
It does not require the tank to be taken completely out of service because it can be lowered into a tank which contains liquid having a layer of sludge at the bottom of the tank. This can result in monetary savings which easily exceed many times over the direct cost of cleaning the tank.
It can use the liquid in the tank as by-pass fluid to fluidize the sludge to be removed or can be supplied with by-pass liquid from an external source, if necessary.
It relies on the auger to process material, as well as to furnish motive power for the apparatus.
It is easily steered along desired paths by remote controls which are manually operable or programmable.
Other objects and advantages of the invention will hereinafter appear.
DRAWINGS
FIG. 1 is schematic view of a tank having apparatus in accordance with the invention disposed therein and associated components disposed thereon;
FIGS. 2 and 3 are perspective views of apparatus in accordance with the invention taken from the front side and left end thereof and from the rear side and right end thereof, respectively;
FIGS. 2A and 3A are perspective views of the platform of apparatus in accordance with the invention taken from the front side and left end thereof and from the rear side and right end thereof, respectively;
FIG. 2B is a bottom plan view of the platform of the apparatus showing details thereof and the auger;
FIG. 4 is a top plan view of the apparatus;
FIG. 5 is an elevation view of the front side of the apparatus;
FIG. 6 is an elevation view of the rear side of the apparatus;
FIG. 7 is an elevation view of the left end of the apparatus;
FIG. 8 is an elevation view of the right end of the apparatus;
FIG. 9 is a cross-section view taken on line 9--9 of FIG. 5;
FIG. 10 is an enlarged top plan view of the apparatus with the pump deleted and showing the steering arm, the slide bearing and the steering ram of the apparatus;
FIG. 11 is a perspective view of the steering arm and the tail wheel;
FIGS. 12 and 12A are schematic views of an elementary control system for the apparatus;
FIG. 13 is a schematic top plan view of another embodiment of the invention; and
FIG. 14 is a schematic view showing a typical path of movement of apparatus in accordance with the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, the numeral 10 designates a first preferred embodiment of improved self-propelled steerable apparatus in accordance with the present invention for removing material 12 from a confined area, such as the bottom surface or floor 13 of a storage tank 14, for disposition elsewhere. The material 12 may, for example, take the form of sludge which has settled at the bottom of a body of liquid L, such as a liquid chemical or oil, in a liquid storage tank such as a chemical or oil tank or the like. Tank 14, which is not shown in scale, could be on the order of 20 to 60 feet high and 25 to 100 feet in diameter and could be filled to a level about five feet below a man-way 15, for example.
Sludge layer 12 is assumed, for purposes of illustration, to be on the order of 10 to 15 inches deep but could be deeper, as hereinafter explained. For example, 10 to 15 inches is typical in petroleum tanks but in chemical processing tanks the depth can reach more than 20 feet.
Tank 14 is provided on top with an access opening or man-way 15 (typically 18 to 36 inches in diameter) through which apparatus 10 is lowered and recovered by means of a hoist cable 11 connected to a hoisting winch 17 temporarily mounted on the roof 19 of the tank. Hoist cable 11 is reeved around a pulley 23 supported on an A-frame mast 25 which is releasably bolted to the man-way flange. Preferably, mast 25 is provided with a crane (not shown) for raising the apparatus 10 and related equipment to the top 19 of tank 14. If man-way 15 is too small to accommodate fully-assembled apparatus 10, portions of the apparatus may be suspended on hoist cable 11 just below the man-way while being assembled/disassembled for lowering/raising relative to tank floor 13.
As hereinafter explained, apparatus 10 requires a back-haul cable or tether 96 to be attached thereto and this cable is connected to a motor-driven back-haul winch 98 which is also temporarily mounted on the top 19 of tank 14. Back-haul cable 96 is reeved around a rotatable back-haul cable pulley 97 which is swivelably mounted on a gin-pole mast 100 about 5 feet above floor 13 of tank 14. Mast 100 is rigidly secured to tank floor 13 and tank top 19. This arrangement enables apparatus 10 to move about floor 13 while keeping cable 96 taught.
Referring now to FIGS. 2 through 9, the improved apparatus generally comprises a support frame or platform 16 having top and rear walls; a horizontally disposed motor-driven reversely rotatable auger 18 beneath the platform; a motor-driven dredge or sludge pump 20 mounted on the platform; and remotely operable steering means 22 mounted on the platform. Platform 16 comprises a top wall or upper deck 24 beneath which auger 18 is rotatably mounted, being supported at one end by a bearing 26 mounted at one end of the platform on a bearing support bracket 39A. Auger 18 is supported at its other end by a reversible hydraulic motor 28 which is mounted on plate 35 at the other end of the platform and connected to said other end of the auger. Platform 16, which in an actual test embodiment was a steel plate about 40" long, 12" wide and 1/4" thick, has a downwardly extending front lip 30 to which a lip extension 32 (portion shown in FIG. 5) is attached. Lip extension 32 serves several purposes, namely: to extend below lip 30 to control the amount of material entering auger 18; to act as a dozer blade to guide material 12 to the auger; to limit penetration of apparatus 10 into the material; and, if extended upwardly above deck 24, as shown in FIG. 9, to as much as 2 or 3 feet, operates to prevent material from flowing over the top of the apparatus.
Referring to FIG. 9 and 10, a rear sealing plate or wall 34 extends downwardly from beneath the rear of deck 24 and cooperates with auger 18 to define a space or passage 36 for accumulating the material so it can be moved or transported by the auger to pump 20 as the auger rotates. As FIGS. 2, 2A, 3 and 3A show, end plate 35 closes one end of passage 36 and another removable end plate 39 curves around bearing support bracket 39A and bearing 26 and closes the other end of the passage.
Rear sealing plate 34 has a curved portion 34A to allow space for the lower portion of a T-shaped conduit 56 hereinafter described in detail which extends into and communicates with space 36 between auger 18 and rear sealing plate 34.
As FIGS. 3 and 4 show, hydraulic motor 28 for auger 18 is rigidly but detachably connected by bolts 29 to plate 35 and has hydraulic fluid inlet/outlet ports 38 and 40 which are connected by hydraulic fluid lines 42 and 44, respectively, to an auger motor control valve 45 shown in FIG. 12.
If preferred, auger 18 may be constructed as hollow so that bearing 26 and motor 28 may be mounted internally thereof to make apparatus 10 even more compact.
As FIGS. 3A and 7 show, rear plate 34 extends downwardly so that its lower edge edge is about 1 inch above the floor 13 of tank 14. To allow for an uneven floor 13 or projections (not shown) a rubber or neoprene flexible sealing lip 34B engageable with the floor is secured to rear plate 34 by entrapment between rear plate 34 and a rigid mounting strip 34C which is secured to the rear plate by a series of bolts 34D. The sealing lip 34B drags along floor 13 and effectively seals the gap between the plate 34 and the floor against leakage of the sludge material to be removed by auger 18.
As FIGS. 2 through 10 show, steering means 22 (hereinafter described in detail) comprises an elongated rigid slide-bearing member 46 which is rigidly mounted on the upper side of deck 24 in spaced apart relationship therefrom and parallel to auger 18. Dredge pump 20, which has a sludge inlet port 48 and a sludge discharge port 50 connectable to a discharge hose 52, is rigidly but detachably mounted on slide-bearing member 46 by brace 21. Dredge pump 20 is driven by a hydraulic dredge pump motor 47 which has hydraulic fluid inlet/outlet ports 49 and 51 which are connected by hydraulic fluid lines 53 and 55 which are connected to a pump control valve 57, as FIG. 12 shows.
Pump inlet port 48 is connected by a quick-disconnect coupling 54 to a T-shaped conduit 56. More specifically, T-shaped conduit 56, is rigidly but detachably mounted on platform 16 by bolts 57 extending through a flange 57A (FIG. 9) to enable it to be installed on the platform after the components have been inserted through the man-way 15. Conduit 56 has an upper by-pass liquid inlet port 56A, a lower sludge inlet port 56B and an intermediate sludge outlet port 56C. Sludge inlet port 56B communicates with the aforesaid space or passage 36, as FIGS. 6 and 9 show, and extends downwardly to within about one or two inches of tank floor 13.
By-pass liquid inlet port 56A is provided with an adjustable, remotely controllable throttle valve VT (FIG. 3). Valve VT is operable to admit only a desired amount of by-pass liquid to sludge pump 20 to facilitate the desired flow of the sludge. The by-pass fluid must be compatible with the liquid in tank 14. In fact, in most cases the by-pass fluid is the liquid in the tank and it can flow directly into valve VT. In rare cases, by-pass liquid from an external source may be required and the valve VT may be used to detachably connect liquid inlet port 56A to a by-pass liquid supply hose 58 which, as FIG. 12 shows, is connected to a by-pass liquid supply 60. Sludge discharge port 56C is connected by coupling 54 to sludge inlet port 48 of pump 20. The bypass liquid must be compatible or miscible with the sludge being removed and mixes with the sludge to render it more easily transported by pump 20.
Referring to FIGS. 2, 3, 4, 5, 6, 7, 8, 10 and 11, remotely operable steering means 22 comprises an elongated rigid L-shaped steering arm or member 62 which extends through a space 64 between upper deck 24 and slide-bearing member 46. One end of steering-arm 62 is pivotally connected to deck 24 by a pivot pin 66. The other end of steering arm 62 is provided with a wheel support bracket 68 which is rigidly connected thereto as by a bolt 70. A tail wheel 72 is rotatably mounted on bracket 68 by an axle 74. Spaced-apart members 76 and 78 are mounted beneath and near opposite ends of slide-bearing member 46 to rigidly support it on deck 24.
An extendible/retractable hydraulic ram or steering cylinder 80 is connected between deck 24 and steering arm 62 by pivot pins 82 and 84 and is operable to pivotally move the steering arm and the tail wheel thereon to effect steering of the apparatus. Ram 80 is provided with hydraulic fluid inlet/outlet ports 86 and 88 which are connected by hydraulic fluid lines 90 and 92, respectively. Line 92 is connected to a steering control valve 94 and line 90 is connected to return line 51 of the hydraulic motor 20, as FIGS. 12 and 12A show. Ram 80 is supplied at one end with hydraulic fluid at a constant pressure of 300 psi, for example, and this creates a bias in one direction. The other end of ram 80 is supplied with hydraulic fluid of variable pressure to effect steering.
Referring to FIG. 10, if steering arm 62 is swung all the way in the direction of arrow E, apparatus 10 tries to pivot in an arc in the direction of arrow F. Movement of steering arm 62 in the opposite way causes apparatus 10 to pivot oppositely in an arc. If the steering-arm is positioned in its dynamic center as shown broken lines in FIG. 10, apparatus 10 will tend to move straight ahead. It should be noted that tail wheel 72 is straight when steering arm 62 is in its dynamic center so as to off-set the unwanted shift of apparatus 10 caused by auger rotation.
Back-haul cable or tether line 96 is connected between winch 98 and a hook 99 on steering arm 62.
As FIG. 1 and 2 show, the apparatus is provided with a jet nozzle 67 for supplying a pressurized stream of compatible liquid to assist in fluidizing the material to be dredged, if this becomes necessary, as hereinafter explained. Nozzle 67 is provided with liquid through a supply hose 67A (FIG. 1) from a suitable pump (not shown). The source of liquid may be filtered liquid which is being returned to tank 14 or can be any compatible liquid. Preferably, nozzle 67 is a known type of back-thrust or balanced nozzle located so as not to interfere with the steering or operation of the apparatus.
OPERATION
It should be understood at the outset that the material 12 to be dredged is similar in its characteristics to sand on an ocean floor in that it is not in itself fluid or fluidized until action is taken to do so. The material can be very fine and packed and needs to be fluidized before it can be handled by pump 20. However, in some cases it may be an organic type material that behaves like a fluidized material without the need to take steps to fluidize it. Note that in the dredging industry material mixed with a liquid to fluidize it is referred to as a slurry and the slurry density is the ratio of material to liquid.
Generally considered, the present apparatus fluidizes the material 12 in the following manner:
(a) the action of auger 18 stirs up the material while moving the material in the direction of inlet port 56B which is connected to the inlet of pump 20;
(b) pump 20 causes fluidization of the material by mixing it with by-pass liquid supplied through throttle valve VT to inlet port 56A;
(c) the forward motion of the apparatus across tank floor 13 also helps in fluidizing the material;
(d) the apparatus operates at the bottom of the slope of the material which it confronts and the material has a natural tendency under the force of gravity to roll to the bottom of the slope, although in some cases the weight of the material becomes greater than its shear resistance, motion occurs and the motion causes fluidization;
(e) in some cases all of the above actions are insufficient to fluidize the material and it is necessary to employ a jet of liquid from jet nozzle 67 which is pointed in the digging direction.
Assume that the apparatus 10 is disposed in tank 14 as shown in FIG. 1, that by-pass liquid supply hose 58 is connected, if needed, that throttle valve VT is opened the proper amount, that discharge hose 52 is properly connected, and that the hydraulic fluid control hoses described above are connected to the winches 17 and 98, to hydraulic pump motor 47, to hydraulic auger motor 28 and to hydraulic steering ram 80. Further assume that back-haul cable or tether 96 is connected to hook 99 at the end of steering arm 62.
If the layer of material is relatively deep (i.e., more than 10 to 15 inches deep when apparatus of the size disclosed herein is employed) and very viscous, other equipment may be used to excavate a hole in the layer of material so that apparatus 10 can reach floor 13. Such equipment may take the form of a crater sink mechanism (not shown) which is disclosed in my U.S. Pat. No. 4,979,322 issued Dec. 25, 1990. As previously mentioned, the sludge depth in a chemical processing tank can reach more than 20 feet. The apparatus 10 cannot work in mid-material but must be in contact with the floor 13 of the tank and the apparatus disclosed in U.S. Pat. No. 4,979,322 can be lowered through the man-way to excavate a crater in the sludge into which the apparatus can descend to the floor.
Now assume that the edge of auger 18 and tail-wheel 72 rest on the tank floor. Rotation of auger 18 then causes apparatus 10 to move in a direction transverse to the auger axis and at the same time moves material toward the discharge end of the auger, through T-shaped conduit 56 and into dredge pump 20 and from thence through discharge hose 52 for final disposition.
As FIG. 14 shows, during a cleaning operation the apparatus moving forward first sweeps in an arcuate path to the left. Then, the position of the steering arm 62 is reversed, the apparatus turns around and the apparatus moves forward and sweeps in an arcuate path to the right. This sweep maneuver sequence is repeated as often as necessary to cover the area to be cleaned. While dredging, the auger 18 always rotates in the forward direction and the apparatus always moves in the forward direction. The auger is only operated in reverse to back away from the tank wall and aid the apparatus in turning.
The forward progress of the apparatus is dependent on the depth and type of material 12. It is to be understood that the auger rotates at a speed of between 0 and 30 rpm. If auger 18 is 10 inches in diameter and the angular (rotational) velocity is 30 rpm, assuming no slip, then the maximum forward velocity would be about 20 feet per minute or 1,178 feet per hour.
It is to be further understood that the back-haul cable 96 is paid out as the apparatus 10 moves forward. The cable 96 is fed out only about one foot at a time. Cable is taken in to pull the apparatus in reverse, as while attempting to move it away from the tank wall during a turn. Care must be taken so as not to allow the apparatus to run over the back-haul cable.
Referring to FIG. 9, if auger 18 is rotating clockwise in the direction of arrow A, apparatus 10 tends to move forward in the direction of arrow B and auger action tends to move material to the sludge inlet port 56B of the apparatus and from thence to pump 20. However, such auger rotation also tends to move apparatus 10 slightly in the general direction of arrow C in FIG. 5. Furthermore, the torque of auger 18 turning in the direction of arrow A tends to cause platform 16 to rotate counter-clockwise in the direction of arrow D in FIG. 9, thus causing a downward force to be exerted on tail wheel 72 to stabilize the apparatus and improve steering.
As previously mentioned, the auger 18 can take various forms and the form chosen determines the behavior of the apparatus 10. If the auger has a single helical spiral, as is the case with auger 18, it rotates to feed sludge to an outlet 56B located at one end of platform 16. However, in such an arrangement auger action tends to cause the apparatus to move or drift slightly in the axial direction of the auger, but such drift is overcome by positioning the tail wheel 72 so that it is at the "dynamic center" of the apparatus. The steering arm 62 can be positioned either by pre-shaping the steering arm (notice the L-shaped configuration in FIG. 10) or by operating the steering cylinder 80 to overcome the tendency of the apparatus to drift.
If, as shown in FIG. 13, the auger 18A has oppositely formed helical flights at opposite ends, the auger can feed sludge to a center outlet 156B on platform 16 and the apparatus has no tendency to drift. As a result, the steering arm 62A for tail wheel 72 can be made straight and centrally located.
Referring to FIG. 1, it is apparent that the system disclosed therein requires various motors to drive auger 18, pump 20, steering arm 62, load hoist winch 17 and back-haul winch 98. Such motors are preferably hydraulic rather than electric because some tank cleaning operations take place in a flammable or explosive environment. The valves which control the several motors are solenoid-operated hydraulic control valves which are remotely located exteriorly of tank 14 and operated by a programmable electronic controller EC which can be manually over-ridden when necessary. Such a controller is disclosed in my aforementioned U.S. Pat. No. 5,093,949.
Typically, the winch motors M1 and M2 for the winches 17 and 98, respectively, are selectively operable by means of solenoid valves V1 and V2. The solenoid valves 45, 57 and 94 for the auger motor 28, the pump motor 47 and the steering ram 80, respectively, readily lend themselves to programmable sequences of operation. Throttle valve VT is operable to control the flow of by-pass liquid to pump 20. The sludge pump 20 preferably takes the form of a variable displacement pump. Referring to FIGS. 12 and 12A, the sludge pump 20, which is hydraulically driven, is supplied with oil by means of a positive displacement control unit EDC. This type of control easily lends itself to remote control, either manually or by an electronic programmable controller EC.
When a cleaning operation is ready to begin, the pump 20 is started and brought up to design speed and the steering arm 62 is centered. Effluent discharge rate and pressure are checked. If all is in accordance with design specifications, auger 18 is slowly speeded up to rated speed for the particular operation.
The back-haul cable 96 is fed out about 6 inches and the pump performance is closely monitored. Then, the back-haul cable 96 is slowly paid out and, at some point, the apparatus will stall against the material 12. If it does not stall, three to five more feet of cable 96 is paid out.
When the material output diminishes, the steering arm 62 is adjusted to steer the apparatus to the left and the speed of auger 18 is adjusted to maintain the rate of material pumping that is best suited to the particular operation. When the apparatus reaches the left side of the tank 14, the steering arm 62 is turned to the right but no back-haul cable 96 is paid out.
When the apparatus reaches the opposite (right) side of the tank 14, the steering arm 62 is turned to the left and, as the apparatus moves to the left, another foot of back-haul cable 96 is paid out. All necessary controls are then adjusted to obtain optimum production for the conditions encountered.
When cleaning is finished, the apparatus is turned off and hoist winch 17 is operated to raise the apparatus to man-way 15 whereat it is disassembled, if necessary, withdrawn from the tank and lowered to the ground.
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Self-propelled steerable apparatus for removing material, such as sludge, from the bottom surface of a liquid storage tank for disposition elsewhere comprises a support platform and a reversely rotatable motor-driven auger mounted below the support platform and cooperating therewith to define a space for receiving sludge when the rotatable auger is engaged with the surface. A motor-driven pump mounted on the support platform is operable to receive sludge from the auger and deliver it through a discharge hose to a remote location. Rotation of the auger delivers the sludge to the pump and propels the apparatus across the surface. A remotely controllable steering mechanism on the support platform has a tail wheel which engages the surface and steers the apparatus along a desired path. A winch-controlled back-haul cable is connected to the apparatus to periodically stop forward movement of the apparatus while the auger is still rotating so that the sludge can be more efficiently removed.
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CROSS-REFERENCE TO PRIOR APPLICATIONS
[0001] This application is a U.S. National Phase Application under 35 U.S.C. §371 of International Application No. PCT/EP2015/055350, filed on Mar. 13, 2015, and claims benefit to Utility Model Application No. DE 20 2014 002 413.8, filed on Mar. 18, 2014. The International Application was published in German on Sep. 24, 2015 as WO 2015/140078 under PCT Article 21(2).
FIELD
[0002] The invention relates to a door arrangement, in particular a house or balcony door arrangement, comprising a door leaf which can be moved relative to a frame, having a locking device which in a locked state locks the door leaf to the frame by at least one locking element, and which in an unlocked state releases the door leaf relative to the frame, wherein an actuating element which can be actuated mechanically by an operator is provided to select the state of the locking device, and wherein, in order to transmit a movement of the actuating element to the at least one locking element, the locking device has a traction rod or driving rod which is arranged displaceably on the door leaf, wherein a motor-driven drive unit for driving the traction rod or driving rod is provided.
BACKGROUND
[0003] A door arrangement of this type has become known under the name “GU-SECURY Automatic mit A-Öffner” [“GU-SECURY Automatic with A-Opener”] by the applicant Gretsch-Unitas GmbH Baubeschläge, Johann-Maus-Straβe 3, 71254 Ditzingen. The already-known door arrangement has the advantage that the motor-driven drive unit provides an additional possible way of driving the traction rod or driving rod, so that a locking state of the locking device can be changed independently of an actuating state of the actuating element (for example a follower or a closing cylinder). In this manner, remote control of the locking device can be realized, for example in order to unlock the street door of an apartment building by a control unit provided in the apartment.
[0004] It is an object of the invention to further improve the operating comfort of the already-known door arrangement.
SUMMARY
[0005] This object is achieved according to the invention in that a sensor device for the contactless detection of a movement of the traction rod or driving rod is provided and in that the motor-driven drive unit can be activated dependent on a movement of the traction rod or driving rod detected by the sensor device.
[0006] In the context of the invention, it has been recognized that in unfavorable conditions it may happen that operation of the actuating element independent of the motor-driven drive unit is accompanied by increased operating forces. According to the invention, it has furthermore been recognized that the traction rod or driving rod is moved upon actuation of the actuating element and that this movement can be detected. The detection of the movement of the traction rod or driving rod takes place in contactless manner, so that the detection of movement as such does not itself contribute to increasing the operating forces necessary for operation of the actuating element. Furthermore, it has been recognized according to the invention that the operating forces for displacing the traction rod or driving rod upon an initial movement of the traction rod or driving rod out of an idle position are still comparatively low, at any rate as long as such a movement of the traction rod or driving rod is not yet effective for changing the locking state of the at least one locking element. Finally, it has been recognized according to the invention that a further movement, succeeding the initial movement, of the traction rod or driving rod can take place in that the drive device already present (for example for the purpose of remote control) is activated and thus the subsequent movement of the traction rod or driving rod which is effective for changing the locking state of the at least one locking element is brought about by the motor-driven drive. This motor-driven driving of the traction rod or driving rod can take place in particular independently of an actuating state of the actuating element, so that a change in the locking state of the at least one locking element takes place exclusively by the action of the motor-driven drive and without operating forces having to be exerted on the operating element.
[0007] Overall, a very comfortably operable door arrangement is provided which is suitable in particular also for stiff locking devices.
[0008] In a preferred embodiment of the invention, provision is made for a first part of the sensor device to be formed by a portion of the traction rod or driving rod and for a second part of the sensor device to be arranged fixed to the door leaf. This has the advantage that movement of the traction rod or driving rod can be detected directly without the traction rod or driving rod having to be changed or converted by an additional sensor part. This is advantageous in particular with regard to the fact that already-known systems referred to first hereinbefore can be retrofitted in a simple manner.
[0009] The portion of the traction rod or driving rod which forms the first part of the sensor device is preferably a material recess or material cutout in the traction rod or driving rod, in particular in the form of an elongate hole pocket or elongate hole aperture. Such material recesses or material cutouts are provided in already-known and conventional traction rods or driving rods in order to screw the lock in the door leaf and nevertheless to permit free movement of the traction rod or driving rod between the faceplate and door leaf. Advantageously, elongate hole pockets or elongate hole apertures can therefore be used without any modification of the already-known traction rods or driving rods being necessary. This too provides a particularly simple possibility of retrofitting for already-known systems referred to first hereinbefore.
[0010] A more preferred embodiment of the invention provides for the second part of the sensor device to be in the form of a coil for generating a magnetic field which is changeable dependent on the position of the traction rod or driving rod. A coil of this type permits the use of a non modified traction rod or driving rod described above. As a result, a contactless sensor device can be provided which furthermore is not susceptible to disruption, for example due to dirt.
[0011] Additionally or alternatively to the use of a coil, the second part of the sensor device is in the form of an optical sensor.
[0012] Further, it is advantageous if the second part of the sensor device and the motor-driven drive are arranged in a common housing.
[0013] This has the advantage that the motor-driven drive of an already-known system referred to first hereinbefore can be exchanged in a simple manner, without additional installation space having to be provided for the second part of the sensor device. This too makes simple retrofitting possible.
[0014] The invention is advantageous in particular when the locking device comprises a plurality of locking elements which cooperate with the traction rod or driving rod. Such locking devices provide a greater degree of security against break-ins in particular for external doors of buildings; the use of a plurality of locking elements is however accompanied by an increase in the operating force necessary for the actuation of the locking elements as a whole. Therefore it is particularly advantageous for a plurality of locking elements if the motor-driven drive unit, once an initial movement of the traction rod or driving rod has been detected, brings about the further, subsequent movement of the traction rod or driving rod and thus drives the locking elements independently of the actuating element which can be actuated by the operator.
[0015] The activation of the motor-driven drive unit dependent on a movement of the traction rod or driving rod which is detected by the sensor device preferably takes place for the purpose of transferring the locking device out of the locked state into the unlocked state, in particular exclusively for the purpose of transferring the locking device out of the locked state into the unlocked state, and not for the purpose of transferring the locking device out of the unlocked state into the locked state. This has the advantage that a possibility of unlocking the locking device which is desired for safety reasons can be triggered by initial low operating forces on the actuating element. This is advantageous in particular when the operator is a child or a frail person.
[0016] In the event that the motor-driven drive unit does not serve to transfer the locking device out of the unlocked state into the locked state, it is preferred for the motor-driven drive unit to transfer the traction rod or driving rod by a pressure force transmission unit in an opening direction out of the locked state into the unlocked state, and for the motor-driven drive unit to be uncoupled from the traction rod or driving rod in a closing direction which is opposed to the opening direction. In this manner, it is possible for unlocking of the locking device to take place by the motor-driven drive unit, but in the event of a power failure and failure of the motor-driven drive unit for the traction rod or driving rod nevertheless—upon application of the operating forces necessary for unlocking, but not counter to self-locking of the motor-driven drive unit—to be able to be actuated both in the opening direction for unlocking the locking device and in the closing direction for locking the locking device. The motor-driven drive unit is therefore then effective only in the opening direction, and in the closing direction is not coupled with the traction rod or driving rod.
[0017] When using an abovementioned pressure force transmission unit, it is more preferable for an initial movement of the traction rod or driving rod which is brought about by the actuating element to be accompanied by an idle stroke of the traction rod or driving rod which ends with a force uptake surface of the traction rod or driving rod, following on from the idle stroke, coming to lie against a force transmission surface of the motor-driven drive unit. In this manner, it is ensured that an initial movement of the traction rod or driving rod is in each case uninfluenced by self-locking of the motor-driven drive unit.
[0018] In a further preferred embodiment of the invention, provision is made for a first part of the sensor device to be formed by an additional element coupled for movement with the traction rod or driving rod, and for a second part of the sensor device to be arranged fixed to the door leaf. The use of an additional element has the advantage that it can be optimized with regard to particularly reliable and accurate detection of a movement of the additional element. Advantageously, the additional element has exclusively the above-mentioned functions. This permits simple retrofitting of an additional element on existing installations.
[0019] It is possible for the additional element and the traction rod or driving rod to be connected together firmly and immovably relative to each other, for example by a positive and/or non-positive connection.
[0020] It is however preferred if the additional element and the traction rod or driving rod are coupled together such that the traction rod or driving rod upon movement in a first direction of movement drives the additional element, and that the additional element upon movement of the traction rod or driving rod is uncoupled from the traction rod or driving rod in a second direction of movement which is opposed to the first direction of movement. This can for example be achieved in that the additional element has an entraining portion which cooperates with only one limitation of a material recess or material cutout (in particular in the form of an elongate hole pocket or elongate hole aperture) formed in the traction rod or driving rod. Preferably the first direction of movement corresponds to unlocking of the locking device (“opening direction”), while the second direction of movement corresponds to locking of the locking device (“closing direction”).
[0021] In the event that the additional element is not coupled with the traction rod or driving rod in both directions of movement thereof which are opposed to each other, it is advantageous to provide a restoring device which transfers the additional element out of a deflected position (into which the additional element has been brought by the traction rod or driving rod) back into a basic position. The restoring device may for example comprise a compression spring or tension spring.
[0022] Further, it is preferred if the second part of the sensor device is in the form of a coil or other suitably formed electrical conductor for generating an electrical, magnetic or electromagnetic field which changes dependent on the position of the additional element. In particular, precisely one and only one coil, or precisely one and only one suitably formed electrical conductor is provided. A coil or a suitably formed electrical conductor permits detection of a movement and/or ascertaining of a position of the additional element. As a result, a contactless sensor device can be provided which furthermore is not susceptible to disruption, for example due to dirt.
[0023] The additional element is preferably at least in portions, in particular as a whole, made from a ferromagnetic material, in particular iron. Such a material influences a magnetic field, the properties of which vary from the point of view of the second part of the sensor device upon displacement of the additional element, so that a movement of the additional element can be detected and/or a position of the additional element can be ascertained.
[0024] Independently of the use of an additional element, additionally or alternatively to the use of a coil or other suitably formed electrical conductor as the second part of the sensor device, other sensors may also be used, for example an optical sensor and/or a capacitive sensor which detects the change in an electrical field.
[0025] Likewise independently of the use of an additional element, in a departure from the feature named in claim 1 “sensor device for the contactless detection of a movement . . . ” it is also possible to use a sensor device which is not contactless. Examples of such non-contactless sensor devices are named below for an electrical sensor and for a mechanical sensor.
[0026] Likewise, as the second part of the sensor device the use of an electrical sensor (for example a potentiometer) which detects the change in electrical parameters (for example resistance, voltage, current, eddy currents) is possible.
[0027] A mechanical sensor, for example a microswitch, can also be used as the second part of the sensor device.
[0028] Further, it is advantageous if the second part of the sensor device and the motor-driven drive are arranged in a common housing. This has the advantage that the motor-driven drive of an already-known system referred to first hereinbefore can be exchanged in a simple manner, without additional installation space having to be provided for the second part of the sensor device. This too makes simple retrofitting possible. In particular, it is preferred if the additional element and/or a restoring device described above is or are also arranged and/or mounted on or in the housing.
[0029] It is more preferable if the additional element has at least two material portions which are adjacent to each other, viewed in the direction of movement of the additional element, which portions have different dimensions from each other, viewed transversely to the direction of movement of the additional element. Therefore in each case more or less material is made available at the level of the material portions which are adjacent to each other, for example by varying the material thickness and/or material height of the material portions. In the event that the material portions are produced from an electrically and/or magnetically conductive material, the second part of the sensor device can detect a different electric, magnetic or electromagnetic field strength or field pattern for a smaller material portion compared with a field strength or a field pattern for a larger material portion.
[0030] A preferred embodiment of the invention provides for the additional element to have at least one land extending in the direction of movement of the additional element, which land has at least one margin which is stepped or arranged inclined relative to the direction of movement. Different positions of the additional element can be detected corresponding to the number of steps; in the case of a margin which is arranged inclined, even a number of positions of the additional element which corresponds to the resolution of the sensor device can be detected. In the simplest case, however, in each case a movement of the additional element can be detected.
[0031] It is likewise conceivable to detect the movement and/or the position of the additional element by its partial arrangement within an electrical, magnetic or electromagnetic field which is generated by a coil or by another suitably formed electrical conductor.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0032] The present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. All features described and/or illustrated herein can be used alone or combined in different combinations in embodiments of the invention. The features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following:
[0033] FIG. 1 : a perspective view of an embodiment of a door arrangement;
[0034] FIG. 2 : a detail designated II in FIG. 1 in an enlarged exploded view;
[0035] FIG. 3 : the detail of FIG. 2 in a side view;
[0036] FIG. 4 : a perspective view of a detail, which corresponds substantially to FIG. 2 , of a further embodiment of a door arrangement, comprising an additional element;
[0037] FIG. 5 : a side view of the additional element; and
[0038] FIG. 6 : a plan view of the additional element.
DETAILED DESCRIPTION
[0039] An embodiment of a door arrangement is designated as a whole by the reference numeral 10 in the drawing. The door arrangement 10 comprises a door leaf 14 which can be moved, for example can be pivoted, relative to a frame. A locking device 16 is provided for locking the door leaf 14 to the frame 12 , which device in the embodiment illustrated comprises two locking elements 18 , 20 . Actuation of the locking device 16 can take place by an actuating element 22 , for example in the form of a closing cylinder 24 . It is also possible for a door handle (not shown) to form an actuating element 22 which cooperates with a follower hub 26 .
[0040] In the embodiment illustrated in the drawing, the actuating element 22 and/or the follower hub 26 is/are part of a lock case 28 . It is possible for the lock case 28 to comprise a bolt 30 which is actuated directly by the actuating element 22 , in particular in the form of the closing cylinder 24 . The lock case 28 may, in addition or alternatively to a bolt 30 also comprise a latch bolt 32 which is actuated directly by an actuating element 22 in the form of a door handle using the follower hub 26 .
[0041] In order to transmit a movement of the actuating element 22 to the locking elements 18 , 20 a traction rod or driving rod 34 is provided which is overlaid by a faceplate 36 in a state mounted on the door leaf 14 . In particular, the traction rod or driving rod 34 and the faceplate 36 extend along a vertically oriented side of the door leaf 14 which is remote from the hinge plate.
[0042] The door arrangement 10 further comprises a motor-driven drive unit which is designated as a whole by the reference numeral 38 , by which the traction rod or driving rod 34 can be driven in particular directly, preferably exclusively in an opening direction 40 of the traction rod or driving rod 34 which is indicated in FIG. 3 .
[0043] The motor-driven drive unit 38 comprises a motor arranged within a housing 42 , by which motor a drive element 44 can be moved in the opening direction 40 of the traction rod or driving rod 34 , and in the opposite direction thereto. The drive element 44 has a force transmission surface 46 which in a locked state of the locking device 16 is spaced apart by an idle stroke 48 from a force uptake surface 50 of a force uptake element 52 which is connected in positive and/or non-positive manner to the traction rod or driving rod 34 .
[0044] The motor-driven drive unit 38 can be connected securely to the faceplate 36 by screws 54 . In such case, it is preferable for the motor-driven drive unit 38 to comprise projections 56 which penetrate material apertures 58 , in particular designed as elongate hole apertures, in the traction rod or driving rod 34 . In such case, a front side of the projections 56 which faces the rear side of the faceplate 36 protrudes over a front side 60 of the traction rod or driving rod 34 , so that the motor-driven drive unit 38 on one hand can be connected securely to the faceplate 36 and on the other hand permits free movement of the traction rod or driving rod 34 between the motor-driven drive unit 38 and the faceplate 36 .
[0045] The door arrangement 10 further comprises a sensor device 62 for contactless detection of a movement of the traction rod or driving rod 34 . The sensor device 62 comprises a first sensor part 64 which is formed by a portion 66 of the traction rod or driving rod 34 .
[0046] A second part 68 of the sensor device 62 is arranged fixed to the door leaf, and therefore does not move jointly with the traction rod or driving rod 34 . The second part 68 of the sensor device 62 is advantageously a coil 70 which generates a magnetic field 72 indicated in FIG. 3 when a current flows through it. An embodiment with two coils 70 is illustrated in the drawing; in another embodiment, merely one coil 70 is provided.
[0047] The magnetic field 72 of a or the coil 70 is changed by changing the position of the traction rod or driving rod 34 , namely in that in the course of a movement of the traction rod or driving rod 34 the degree of coverage of the material aperture 58 which is in the form of an elongate hole relative to the coil 70 changes. The change in the magnetic field 72 brings about a change in a current flowing through the coil 70 . This change is detected by a control unit and on exceeding a specifiable threshold value is used to activate the motor of the motor-driven drive unit 38 .
[0048] Starting from a closed state of the door leaf 14 , in which the door leaf 14 lies against the frame 12 , and starting from a locked state of the locking device 16 , in which the locking elements 18 and 20 lock the door leaf 14 to the frame 12 , actuation of the actuating element 22 by an operator causes the traction rod or driving rod 34 to be moved starting from the state illustrated in FIG. 3 . Due to the idle stroke 48 , in such case the traction rod or driving rod 34 can be moved counter to the force of gravity (i.e. upwards); it is sufficient for the traction rod or driving rod 34 , starting from its rest position, to be displaced at all and in so doing for the relative position of the material aperture 58 of the traction rod or driving rod 34 relative to the coil 70 to change. The change in the magnetic field 72 which is detectable thereby is used by the control unit of the motor-driven drive unit 38 to activate the motor.
[0049] Once the idle stroke 48 or part of the idle stroke 48 has been overcome and the force transmission surface 46 has subsequently come to lie against the force uptake surface 50 , further driving of the drive element 44 brings about a movement of the traction rod or driving rod 34 in the opening direction 40 . In this manner, the locking elements 16 , 18 are unlocked in a manner known per se; in such case, operating forces on the actuating element 22 can be dispensed with entirely.
[0050] Once the locking device 16 has been released, the door leaf 14 can be opened.
[0051] The locking elements 18 , 20 are for example spring-actuated latch bolts. Transferring of the traction rod or driving rod 34 counter to the opening direction 40 can take place by the spring actuation and/or by the traction rod or driving rod 34 being displaced downwards due to its own weight.
[0052] The housing 42 is provided spatially separated from the lock case 28 . This simplifies retrofitting of an existing installation.
[0053] The magnetic field 72 is in particular an electromagnetic field.
[0054] FIG. 4 illustrates an assembly which can be used instead of the components illustrated in FIG. 2 . In FIG. 4 , however, the traction rod or driving rod 34 and the faceplate 36 are not shown in order to improve clarity. The mode of operation of the assembly according to FIG. 4 corresponds to the mode of operation described above with reference to FIGS. 1 to 3 ; identical reference numerals are used for identical or functionally identical components. The assembly according to FIG. 4 too comprises a housing 42 and a motor-driven drive 38 . The drive 38 has a motor 74 which cooperates with a drive element 44 (cf. FIG. 2 ) via an actuator 76 .
[0055] The assembly according to FIG. 4 comprises an additional element designated as a whole by the reference numeral 78 , which is mounted displaceably on the housing 42 . The additional element 78 forms the first part 64 of the sensor device 62 . The second part 68 of the sensor device 62 is formed by a single coil 70 .
[0056] The additional element 78 is in particular in the form of a metal part which is preferably produced by forming. The additional element 78 is produced in particular from a magnetic material.
[0057] The additional element 78 has for example a material thickness 80 of approx. 0.5 mm to approx. 0.9 mm, in particular of approx. 0.7 mm (cf. FIGS. 5 and 6 ). The additional element 78 has a main plane 82 and an additional plane 84 . The main plane 82 is arranged within the housing 42 . The additional plane 84 runs parallel to the main plane 82 and offset in the direction of the faceplate 36 .
[0058] The main plane 82 has a reference portion 88 at a free end 86 . This portion comprises two lands 90 , which jointly delimit a gap 92 . The lands have margins 94 facing the gap 92 . The margins 94 are oriented inclined relative to a main direction of extent 96 of the additional element 78 , for example at an angle of approx. 5° to approx. 30°.
[0059] The main direction of extent 96 of the additional element 78 corresponds to an axis along which the additional element 78 can be moved relative to the housing 42 . This axis runs parallel to an axis of movement of the traction rod or driving rod 34 . The axis of movement 42 is defined by the opening direction 40 and a closing direction which is opposed thereto.
[0060] As a result of the margins 94 which are oriented inclined, the reference portion 88 , viewed in the direction of movement of the additional element 78 , has smaller material portions 98 and larger material portions 100 which are arranged adjacent to one another. These material portions preferably merge continuously into each other.
[0061] The main portion 82 of the additional element 78 has on its end remote from the reference portion 88 an angled portion 102 , which together with a fixing device 104 (cf. FIG. 4 ) fixed to the housing serves to arrange a restoring device 106 in the form of a tension spring 108 .
[0062] The additional portion 84 has a entraining portion 110 which faces away outwards relative to the housing 42 , which portion cooperates with a (lower, in the drawing) limitation 112 of the material recess or material cutout 58 , formed in the traction rod or driving rod 34 , in the form of an elongate hole pocket or elongate hole aperture (cf. FIG. 2 ).
[0063] Upon a movement of the traction rod or driving rod 34 in the opening direction 40 , the limitation 112 of the material recess or material cutout 58 entrains the additional element 78 in the identical direction, so that the reference portion 88 moves relative to the coil 70 . This movement can be detected by the sensor device 62 , in order subsequently to activate the motor-driven drive unit 38 , so that a further movement of the traction rod or driving rod 34 is supported in a motor-driven manner.
[0064] During the course of the displacement of the additional element 78 , the restoring device 106 is tensioned. If then the traction rod or driving rod is moved in a closing direction opposed to the opening direction 40 , the limitation 112 of the material recess or material cutout 58 lifts off from the entraining portion 110 . Returning of the additional element back into the non-deflected position takes place independently of the movement of the traction rod or driving rod 34 in that the energy stored in the restoring device 106 is released, in particular in that the tension spring 108 contracts.
[0065] Moreover, for example with respect to the fastening of the housing 42 to the faceplate 36 , reference is made to the description relating to FIGS. 1 to 3 for the embodiment illustrated in FIGS. 4 to 6 .
[0066] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments.
[0067] The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.
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A door arrangement includes a door leaf movable relative to a frame. A locking device in a locked state locks the door leaf to the frame by at least one locking element and in an unlocked state releases the door leaf relative to the frame. An actuating element selects the state of the locking device. To transmit a movement of the actuating element, the locking device has a connecting bar which is arranged displaceably on the door leaf, wherein a motor-operated drive unit for driving the connecting bar is provided. A sensor device for the contactless detection of a movement of the connecting bar is provided and the motor-operated drive unit can be activated in accordance with a movement of the connecting bar detected by the sensor device.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to a Leg Muscle Therapy Apparatus which has a frame structure composed of at least two support structures, each having a generally arc shaped inner surface, with the support structures being adjustably coupled together. Each support structure has rounded user engagement elements along the arced inner surface of the structure which may be used to engage the thigh and calf of the user, allowing the user to perform body therapy routines on these areas of the lower body. These therapy routines may be performed while the user is in any type of relaxed position by grasping the invention with their hands and moving the invention over the desired thigh or calf area of the lower body. The invention will automatically adjust itself to different thigh and calf contours, since these muscles are typically smaller at the lower ends. The ability of the apparatus to engage any area of the leg muscle with the engagement elements of the support structure, and also its ability to easily adjust itself for the various thickness and contours of the thigh and calf muscles, allows for an easy and comfortable message type therapy for those particular leg muscle groups which are sore or have been traumatized due to an accident or illness. The invention may also be used to assist in the removal of fat tissues and cellulite from any affected leg muscle area.
SUMMARY AND OBJECTS OF THE INVENTION
[0002] It is the object of this invention to provide a therapeutic apparatus which may provide the user as efficient and inexpensive means for messaging the leg muscle groups of the lower body. The main purpose of this application is to demonstrate an apparatus which performs the stated function, and to demonstrate the many options and configurations this apparatus may take on.
[0003] Briefly stated, the apparatus that forms the basis of the present invention comprises a frame structure means, a coupling means, and a user engagement means. The frame structure means may be comprised of at least two main support member, each having an arc shaped inner surface onto which the user engagement means may mount. The main support members may include a hand engagement member so that the user may easily grasp the structure with their hands. The coupling means of the apparatus couples the two main support members together so that they may easily move in a controlled manner away and towards one other as the varying contours of the leg muscles are being engaged by the user engagement means. Movement may be in either along a generally arced path or along a generally linear path, depending upon the design of the apparatus. The apparatus may also utilize a resistance means which provides resistance to the members moving apart from one another, and which may also provide a force against the leg muscles by the user engagement means.
[0004] In order to operate the apparatus, the user will grasp the main support members with their hand, place their leg within the opening created by the main support members, and move the Leg Muscle Therapy Apparatus along the thigh and/or calf area of the lower body, in either a linear or circular pattern. As mentioned, the leg of the user will be placed within the apparatus, which has a ring-type form when the two main support members are coupled together. As the apparatus moves along an area of the leg, such as the thigh muscles, the main support members will begin to separate, or move opposite one another, as the apparatus moves over the larger areas of the thigh muscles. This separation may he resisted by the hands of the user, or by the optional resistance means, or both. Also, as the apparatus moves back over the smaller areas of the thigh muscles, the main support members will move back towards one another, either by the user pushing the members back together or by the force exerted on the members by the optional resistance means which pulls them back together, or both. The resistance to separation, as provided by either the hands of the user or the optional resistance means, thus allows a force to be applied to the thigh area as the apparatus moves along its various contours.
[0005] Also, other configurations may be possible which allow the apparatus to increase it flexibility. The apparatus may be designed to utilize more than two main support members coupled together to increase the amount of leg muscles area being engaged at any given time. Also, additional resistance components may be added to the apparatus to easily vary the amount of resistance to separation, and thus the amount of force provided by the apparatus against the leg muscle of the user. Also, having a user engagement means which is a completely separate component from the main support member may be preferred.
[0006] The overall basic design of the apparatus is such that the user engagement means may be a component which mounts upon the arced inner surface of the main support member and provides the main contact with the leg muscle of the user. The user engagement means may be a series of user engaging elements which are rounded, nodule-like elements which extend outward from the arced inner surface of the main support members. They may be spaced apart from each other so that maximum contact is provided upon the leg muscle. The user engaging elements may be a molded part of the main support member, individually attached components, or part of a user engagement means which is separately attached. The user engaging elements may also be a type of roller bearing elements which roll as they engage the leg muscle of the user. As mentioned previously, the force exerted on the leg muscles by the user engaging elements may be applied by the hands of the user, by an optional resistance component, or both. The user engaging elements will therefore apply a firm force against the leg muscles, and provide a deep therapeutic message. The arc design of the inner surface of the main support members allows numerous engaging elements to simultaneously be in contact with the leg muscles, allowing for a maximum therapeutic effect. The arced inner surface of the main support member also allows the apparatus to be easily moved by the user along the leg muscles not only in a forward and backward linear motion, but also in a circular motion around the leg muscle, either individually or simultaneously. In addition to providing a type of therapeutic exercise of the thigh and calf muscles as described, the apparatus will also assist with the removal of fat tissues and cellulite from affected areas of the leg by breaking them down and allowing the body to naturally dissolve the fat tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1A is a front view of the Leg Muscle Therapy Apparatus.
[0008] FIG. 1B is a side view of the Leg Muscle Therapy Apparatus.
[0009] FIG. 1C is a top view of the Leg Muscle Therapy Apparatus,
[0010] FIG. 2A is a front view of a main support member of the frame structure means and the user engagement means of the Leg Muscle Therapy Apparatus.
[0011] FIG. 2B is a side view of a main support member of the frame structure means and the user engagement means of the Leg Muscle Therapy Apparatus.
[0012] FIG. 2C is a top view of a main support member of the frame structure means of the Leg Muscle Therapy Apparatus.
[0013] FIG. 3A is a front view of the coupling means of the Leg Muscle Therapy Apparatus.
[0014] FIG. 3B is a side view of the coupling means of the Leg Muscle Therapy Apparatus.
[0015] FIG. 3C is a top view of the coupling means of the Leg Muscle Therapy Apparatus.
[0016] FIG. 3D is a side view of the Leg Muscle Therapy Apparatus demonstrating how the coupling means joins together the main support members of the frame structure means.
[0017] FIGS. 4A and 4B are front views of the Leg Muscle Therapy Apparatus demonstrating the automatic adjusting feature of the apparatus which occurs as the apparatus is moved along the various contours of the leg muscles, along with the optional resistance means.
[0018] FIG. 4C is a side view of the Leg Muscle Therapy Apparatus demonstrating a cross sectional area of a user leg located within the apparatus, and demonstrating how the user engagement means of the apparatus engages the leg of the user while moving along its contour, and also how the main support members reacts accordingly.
[0019] FIG. 4D is a side view of the muscle therapy apparatus demonstrating a cross sectional area of a user leg located within the apparatus, and demonstrating how the user engagement means of the apparatus engages the leg of the user while moving along its contour, and also how the main support members reacts accordingly, with a resistance means located at the top, and the main support members being shorter in length.
[0020] FIG. 5A is a front view of the Leg Muscle Therapy Apparatus having roller bearings as user engagement elements of the user engagement means for making movement of the body therapy apparatus smoother.
[0021] FIG. 5B is a side view of the inner surface of the Leg Muscle Therapy Apparatus demonstrating multiple row series of user engagement elements which may allow for greater contact with the leg muscle and thus a greater therapeutic message
[0022] FIG. 6A is a front view of the Leg Muscle Therapy Apparatus having user engagement means which are separate components pivotally mounted to the inner surface of the main support members.
[0023] FIG. 6B is a front view of the Leg Muscle Therapy Apparatus having user engagement means which are separate components pivotally mounted to the inner surface of the main support members, and also demonstrating a cross sectional area a user leg located within the apparatus, and demonstrating how the user engagement means and main support members of the apparatus react as the user engagement means engages the leg of the user while moving along its contour.
[0024] FIG. 6C is a side view of the user engagement means of the muscle therapy apparatus which is pivotally mounted to the inner surface of the main support members.
[0025] FIG. 6D is a side view of the user engagement means of the muscle therapy apparatus, showing two user engagement means pivotally mounted to the inner surface of the main support members with, each mounted so that they may pivot independent of one another.
[0026] FIG. 7A is a front view of a second version of the Leg Muscle Therapy Apparatus.
[0027] FIG. 7B is a side view of a second version of the Leg Muscle Therapy Apparatus.
[0028] FIG. 7C is a top view of a second version of the Leg Muscle Therapy Apparatus.
[0029] FIG. 8A is a front view of a main support member of the frame structure means, along with the user engagement means, both for the second version of the Leg Muscle Therapy Apparatus.
[0030] FIG. 8B is a side view of the inner surface of a main support member of the frame structure means along with the user engagement means, both for the second version of the Leg Muscle Therapy Apparatus.
[0031] FIG. 8C is a top view of a main support member of the frame structure means, both for the second version of the Leg Muscle Therapy Apparatus.
[0032] FIG. 8D is a side view of the outer surface of a main support member of the frame structure means, for the second version of the Leg Muscle Therapy Apparatus.
[0033] FIG. 9A is a front view of the coupling means for the second version of the Leg Muscle Therapy Apparatus.
[0034] FIG. 9B is a side view of the coupling means for the second version of the Leg Muscle Therapy Apparatus.
[0035] FIG. 9C is a top view of the coupling means for the second version of the Leg Muscle Therapy Apparatus.
[0036] FIG. 9D is a side view of the coupling means for the second version of the Leg Muscle Therapy Apparatus, demonstrating the various components of the coupling means.
[0037] FIGS. 10A and 10B are side views of the second version of the Leg Muscle Therapy Apparatus demonstrating a cross sectional area of a user leg located within the apparatus, and demonstrating how the user engagement means of the apparatus engages the leg of the user while moving along its contour, and also how the main support members react accordingly.
[0038] FIGS. 10C and 10D are front views of the Leg Muscle Therapy Apparatus demonstrating the automatic adjusting feature of the apparatus which occurs as the apparatus is moved along the various contours of the leg muscles, along with the optional resistance means.
[0039] FIGS. 11A and 11B are front views of the second version of the Leg Muscle Therapy Apparatus having user engagement means which are separate components pivotally mounted to the inner surface of the main support members, and also demonstrating a cross sectional area of a user leg located within the apparatus, and demonstrating how the user engagement means and main support members of the apparatus react as the user engagement means engages the leg of the user while moving along its contour.
[0040] FIGS. 12A and 12B are front views of the second version of the Leg Muscle Therapy Apparatus demonstrating the main support members of the apparatus having a larger inner radius of curvature.
[0041] FIGS. 13A, 13B, and 13C are front views of a third version of the Leg Muscle Therapy Apparatus demonstrating an apparatus with more than two main support members, and how the main support members react as the user engagement means is moved along the leg of the user.
[0042] FIGS. 14A and 14B are front views of the Leg Muscle Therapy Apparatus with a main support member having a user engagement means which is both pivotally and linearly mounted as a separate component such that the user engagement means may pivot in an arced path and simultaneously move back and forth along a linear path.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0043] Before explaining in detail the present invention, it is to be understood that the invention is not limited in its application to the details of construction or arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description, and not limitation.
[0044] As best can be seen by references to the drawings, and in particular to FIGS. 1A-1C , the Leg Muscle Therapy Apparatus that forms the basis of the present invention is designated generally by the reference numeral 1 , and includes a frame structure means 10 , coupling means 20 , and user engagement means 30 . The frame structure means 10 may be structured in such a manner that it has a circular form into which the leg of the user may be placed. The components of the frame structure means 10 and the coupling means 20 are mounted together in such a manner that the apparatus may automatically adjust to different leg muscles sizes and contours.
[0045] As may be seen in FIGS. 2A-2D , the frame structure means 10 may comprise at least two main support members 11 , user handle members 12 , and support coupling members 13 with coupling member openings 14 . The main support member 11 may be a relatively rigid structure having an outer surface and a curved inner surface. The curved inner surface supports user engagement means 30 . The user engagement means 30 may be a series of rounded nodule-like user engagement elements 31 which extend outward from the inner surface of the main support member 11 . They may be a molded part of the main support member 11 , or they may be individually attached in some typical manner such as a screw. User handle member 12 may be an open area extending through main support member 11 which allows the user to more easily grasp and hold the main support member 11 with their hand. As further shown, main support member 11 has support coupling members 13 mounted at one end, with the support coupling member 13 having a coupling member opening 14 . Coupling member opening 14 is an elongated shaft-like opening extending from one side of the main support member 11 to its opposite side.
[0046] In the figures, user engagement means 30 has user engaging elements 31 which are rigidly mounted to the inner surface of main support member 11 . As mentioned, they may be individually mounted elements or molded to the inner surface of the main support member. They could also be part of a separate curved user engagement means which rigidly mounts to the inner surface of main support member 11 through a mounting element such as a screw. The figures also show a handle member 12 which extends as a curved opening through the main support member 11 , but the user handle member 12 could also be just an indented space extending a small distance into the main support member 11 . The handle member 12 could also be a separate component mounted at some location on main support member 11 . It is also possible for the user to just grasp each main support member 11 with their respective hand so that the members themselves function as a type of handle member, provided the members are sized to easily grasp. Many variations of this apparatus are thus possible.
[0047] As may be seen in FIGS. 3A-3D , coupling means 20 comprises a generally elongated shaft member 21 with stop members 22 mounted on each end. Stop members 22 are used to prohibit the main support members 11 from separating completely from on another as they move. The stop members 22 may be a type of locking cap which slide onto shaft member 21 and lock in place. Shaft member 21 and stop members 22 may also be a type of bolt and screw assembly. FIG. 3D demonstrates how the coupling means 20 and frame structure means 10 mount together so that the main support members 11 may pivot about shaft member 21 .
[0048] FIGS. 4A and 4B demonstrate the basic configuration and operation of the apparatus. As shown, the support coupling members 13 of main support members 11 are coupled together by shaft members 21 and form a generally loop shaped structure. Shaft members 21 extend through the coupling member openings 14 of each support coupling members 13 . As mentioned, stop members 22 are mounted on each end of shaft member 21 to limit the amount of separation possible between the two main support members 11 . The apparatus may include an optional resistance component 40 , such as a resistance band.
[0049] As may be further seen, the user may operate the apparatus by grasping the apparatus with their hands using the user handle members 12 , while placing their leg within the open loop area created by the coupling of the two main support members 11 . Shown in the FIG. 4C is a typical cross section of a human leg. Using the handle members 12 , the user may grasp the apparatus and move it over the desired leg muscle, with the leg muscles being engaged by the user engaging members 31 of the user engagement means. As the apparatus moves along the respective leg muscle group, the user engaging members 31 will make contact with the respective muscles, providing a type of therapeutic message. As also shown, as the apparatus moves along the contour of the thigh or calf muscles, the main support structures 11 of the apparatus will pivot apart from one another as larger areas of the leg muscles are being engaged. They will pivot closer to one another as smaller portions of the leg muscles are being engaged. While moving the body therapy apparatus along the thigh or calf muscles of the leg, the user may also simultaneously rotate the apparatus in a circular pattern around the leg to provide an even better therapeutic action. For a smaller area that may need a heavy message, the user may want to rotate the apparatus in a back and forth circular motion only over that area of the leg needing the heavier message. This ability to engage the leg muscle in a linear or circular motion, either individually or simultanously, makes the apparatus extremely flexible. FIG. 4D is a side view of the muscle therapy apparatus demonstrating a resistance means located at the top, and the main support members being shorter in length. This should allow the apparatus to more easily be placed upon the leg.
[0050] As shown, the main support members 11 are guided as they pivot away and towards one another by shaft member 21 . Optional resistance component 40 may be mounted at either end of main support member 11 , and may be utilized to provide a resistance to the pivoting motion of main support members 11 , while also pushing the main support members 11 back towards one another. When the resistance component 40 utilizes a conventional resistant band, different resistant band with different strengths may be used to provide different amount of resistance. These resistance bands 40 may be convention resistance bands found and used in various fitness equipment and may mount to main support members 11 through a typical securing means such as a pin or bolt 41 . Multiple resistance bands 40 may be utilized which mount to the main support members 11 at the top and bottom, and on both the front and back sides. When the resistance component 40 is not utilized, the resistance to separation and the pushing motion of the members back together may be accomplished manually by the hands of the user.
[0051] It is also possible to disassemble the leg apparatus so that the individual main support structures 11 are utilized separate from one another. The user may grasp a single main support member 11 , either one at a time or one in each hand, and perform a therapy routine on parts of the body other than the leg muscles. For example, if the user is suffering from a sore arm bicep muscle, the user may grasp one of the main support members 11 with one hand, and move the user engaging elements 31 along the bleep muscle, in either a linear motion, circular motion, or both. This routine may be performed also on other parts of the body, such as the stomach, hips, or buttocks. Using an individual main support member 11 may also be performed on the leg muscles, but would not provide as much therapeutic action as the members would when coupled together.
[0052] FIG. 5A demonstrates the Leg Muscle Therapy Apparatus using conventional roller bearings 32 as user engaging elements 31 . Roller bearings 32 may be mounted within curved openings 33 , which are semi-spherical in shape and have a larger diameter than do the roller bearings 32 . This is to allow the roller bearings 32 to rotate within in any direction. The roller bearings 32 may be held in place by inner surface support 34 , which may have surface openings 35 which are smaller in diameter than the roller bearings 32 . The inner surface support 34 may be securely mounted to the arced inner surface of the main support member 11 through some common securing means, such as a screw, with the surface openings 35 of the inner surface support 34 being place over the roller bearings 32 . This allows roller bearings 32 to rotate, but keeps them from exiting out of curved openings 33 . In this instance, the user engagement means 30 is comprised of roller bearings 32 , curved openings 33 , inner surface support 34 , and surface openings 35 .
[0053] FIG. 5B demonstrates the Leg Muscle Therapy Apparatus utilizing multiple rows of user engaging elements 31 mounted to main support member 11 , instead of only a single row. Multiple rows should allow for a better therapy message, since multiple user engaging elements 31 will move over the same area. It may also prove better to have each row staggered from the one next to it, so that more contact is made with the muscles. The figures show three rows of user engaging members 31 , but many versions of the apparatus may be created having four, five, six, or even more rows, depending on what works best for the individual user. It may be possible to connect two or more apparatuses together, so that the number of rows in contact with the user muscles may be selectively varied. As mentioned previously, the. user engaging elements 31 may be a molded part of main support member 11 , may be individually attached to main support member, or may be part of a separately attached user engagement means. The best configuration, which is that shown, may prove to be a series of rows of roller hearings 32 mounted into curved openings 33 and held in place by inner surface support 34 having surface openings 35 .
[0054] FIGS. 6A and 6B demonstrate a Leg Muscle Therapy Apparatus having the user engaging elements 31 incorporated into a user engagement means 30 which is a completely separate component from the main support member 11 . The user engaging members 31 may mount upon or may be part of an engagement support structure 36 , which may be pivotally mounted at its approximate center to the inner surface of main support member 11 . The engagement support structure 36 may be an arced structure having an outer and inner arced surface. As shown, the outer arc surface may be pivotally mounted at its proximate center to the arced inner surface of main support member 11 , while the user engaging members 31 may mount upon the inner arced surface of engagement support structure 36 . The engagement support structure 36 may also be constructed with curved openings so that user engaging members 31 . may be roller bearings, as has been discussed previously. As also shown, an alternate configuration may have the resistance band 40 located near the coupling means 20 , instead of being located on the opposite end of the main support members. This configuration will allow the user to position the apparatus over the leg muscles, instead of the leg muscles having to be placed within. FIG. 6B shows a cross sectional area of a user leg placed with the apparatus, and demonstrates how the user engagement means 30 reacts when it engages the leg of the user.
[0055] FIGS. 6C and 6D show side views of one type of user engagement means 30 for the Leg Muscle Therapy Apparatus. In this type, there is at least one row of user engaging members 31 mounted to the engagement support structure 36 . As may be seen, it is possible to have more than one, in this case, two engagement support structures 36 pivotally mounted to the inner surface of main support member 11 such that they pivot independent of one another. This could prove useful for not only engaging a larger area of the leg of the user, but also allow better adjustment to the varying contours of the leg of the user. Having more than one row of user engaging members 31 may also prove beneficial in use with the multiple engagement support structures 36 .
[0056] A second version of the Leg Muscle Therapy Apparatus 1 may be seen in FIGS. 7A-7C . As with the original version, the Leg Muscle Therapy Apparatus is designated generally by the reference numeral 1 , and includes a frame structure means 10 , coupling means 20 , and user engagement means 30 . The frame structure means 10 may be structured in such a manner that it has a circular form into which the leg of the user may be placed. The components of the frame structure means 10 and the coupling means 20 are mounted together in such a manner that the apparatus may automatically adjust to different leg muscles sizes.
[0057] As may be seen in FIGS. 8A-8D , the frame structure means 10 may again comprise at least two main support members 11 , user handle members 12 , and support coupling members 13 with coupling member openings 14 . The main support member 11 may be a relatively rigid structure having an outer surface and a curved inner surface. The curved inner surface supports user engagement means 30 . The user engagement means 30 may be rounded nodule-like user engagement elements 31 which extend outward from the inner surface of the main support member 11 . They may be a molded part of the main support member 11 , or they may be individually attached in some typical manner such as a screw. User handle member 12 may be an open area extending through main support member 11 which allows the user to more easily grasp and hold the main support member 11 with their hand. As further shown, main support member 11 has support coupling members 13 mounted at each end, with each support coupling member 13 having a coupling member opening 14 . Coupling member opening 14 is an elongated shaft-like opening extending from the inner portion of the main support member 11 to its outer portion.
[0058] As may be seen in FIGS. 9A-9D , coupling means 20 comprises a generally elongated shaft member 21 with stop members 22 mounted on each end. Coupling means 20 may also comprise optional resistance spring members 23 , which are basically conventional coiled spring members located on each end of shaft member 21 , and are held in place by stop members 22 . Stop members 22 are used to prohibit the main support members 11 from separating completely from on another as they move, whether the optional resistance springs 23 are utilized or not. The stop members 22 may be a type of locking cap which slide onto shaft member 21 and lock in place. Shaft member 21 and stop members 22 may also be a type of bolt and screw assembly.
[0059] As with the original version, the components of the frame structure means 10 , the coupling means 20 , and the user engagement means 30 , all function in similar manner and may also take on various configurations. The main difference in this version is that main support members 11 move away and toward one another along a linear path of motion, as opposed to an arced path of motion.
[0060] FIGS. 10A and 10B show a cross sectional area of a user leg placed within the apparatus. As may be seen, when various parts of the leg which are different in size are engaged by the user engaging members 31 , the main support members will move accordingly. When a larger cross sectional area is engaged, the main support members 11 move away from one another. When a small cross sectional aim is engaged, the main support members 11 move towards one another. Again, motion is along a linear path.
[0061] As shown in FIGS. 10C and 10D , optional resistance means 40 comprising optional resistant bands 41 may be also utilized with this version of the apparatus. As before, different resistant bands having different resistance strengths may be used to vary the amount of resistance. These resistance bands 40 may be convention resistance bands found and used in various fitness equipment and may mount to support coupling members 13 through a typical seeming means such as a pin or bolt 42 . Multiple resistance bands 41 may also be utilized which mount to the support coupling members 13 at the top and bottom of each main support member. and on both the front and back sides. When the resistance component 40 is not utilized, the resistance to separation and the pushing motion of the members back together may be accomplished manually by the hands of the user.
[0062] FIGS. 11A and 11B demonstrate the second version of the Leg Muscle Therapy Apparatus having the user engaging elements 31 incorporated into a user engagement means which is a completely separate component from the main support member 11 . The user engaging members 31 may mount upon or may be part of an engagement support structure 36 , which may be pivotally mounted at its approximate center to the inner surface of main support member 11 . The engagement support structure 36 may be an arced structure having an outer and inner arced surface. As shown, the outer arc surface may be pivotally mounted at its proximate center to the the arced inner surface of main support member 11 , while the user engaging members 31 may mount upon the inner arced surface of engagement support structure 36 . The engagement support structure 36 may also be constructed with curved openings so that user engaging members 31 may be roller bearings, as has been discussed previously. FIG. 11A and 11B both demonstrates a cross sectional area of a user leg which has the apparatus placed within. FIG. 11A and 11B show a cross sectional area of a user leg placed within the apparatus, and demonstrates how the user engagement means 30 reacts when it engages the leg of the user.
[0063] In any version, having the user engaging member 31 mounted on an engagement support structure 36 which is pivotally mounted as a separate component to the main support member 11 should provide a much more flexible body therapy apparatus. As also shown, the engagement support structure 36 may pivot both towards and away from the inner surface of main support member 11 . Shown in the figures is a cross section of the human leg. When the apparatus is moved along a portion of the leg of the user, the pivoting motion of the engagement support structure 36 allows the user engaging members 31 to remain in better contact with the leg muscle of the user. This concept will make the apparatus more complicated and thus more expensive, but should provide more flexible and a better therapy routine. This concept may be incorporated into any of the versions described previously. As also mentioned previously, a single main support member 11 having this pivoting engagement support structure 36 may be used to provide therapy to other parts of the body, such as the biceps of the arm, the hips, the stomach, and the buttocks.
[0064] FIG. 12A and 12B demonstrate a different construction feature for the second version of the Leg Muscle Therapy Apparatus 1 . In this version, the frame structure means 10 forms a more elliptical shape when coupled together by coupling means 20 , as opposed to the more circular shape shown previously. This elliptical shape may prove to provide better contact between user engagement means 30 and leg muscles which are larger in size than normal. This may prove true also tor the original pivoting version, and also for the user engagement means when it is a separately attached component.
[0065] FIGS. 13A and 13B demonstrate another version of Leg Muscle Therapy Apparatus 1 having a frame structure means 10 with more than two main support members coupled together. In this instance, frame structure means 10 has four main support members coupled together by four coupling means 20 . In this version, each of the main support members comprise a quarter-arc shape, with all four quarter-arc shaped main support member creating a closed circular shaped frame structure means 10 when coupled together. FIG. 13C demonstrates this version having a separately mounted user engagement means 30 .
[0066] FIGS. 14A and 14B demonstrate a Leg Muscle Therapy Apparatus having an engagement support structure 36 which is both pivotally and linearly coupled to the main support member 11 . The engagement support structure 36 will not only pivot towards and away from the inner surface of the main support member 11 , but also move along a linear path towards and away from its inner surface. The main support member 11 thus serves as a type of guide bearing for guiding the engagement support structure 36 along a linear path of motion. In this case the handle member 12 would more than likely need to be an indented space into the main support member 11 instead of a through space.
[0067] In this version, a spring member 23 may also be used to resist the movement of the engagement support structure 36 towards the inner surface of the main support member 11 . It will also push the engagement support structure back against the leg muscle of the user. Therefore a spring member or some type of resistance hand will not necessarily be used by the coupling means and the support coupling members as previously shown. Instead of two or more main support members, the main structure means may now be constructed of only one arced or circular shaped main member, since the linear movement away and towards the leg muscle of the user is now done by the engagement support member, not the support coupling member and the coupling means. The main disadvantage with this version is that resistance may no longer be applied by the hands of the user. Multiple main support members may still be utilized, but may now be rigidly connected together using a bolt and nut. However, an apparatus may still be constructed which has two or more main support members connected together using a coupling means, and also utilize a pivoting and linear moving engagement support structure. Hence the combinations and variations of the body therapy apparatus derived from this capability are numerous.
[0068] Many variations of the Leg Muscle Therapy Apparatus exist, along with the configurations described above. While it will be apparent that the preferred embodiment of the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation, and change without departing from the proper scope or fair meaning of the subjoined claims.
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A Leg Muscle Therapy Apparatus is provided which enables the user to easily and comfortable engage the various muscles of the leg, providing the leg muscles with a therapeutic message which helps to loosen and relieve sore or damages muscles. The apparatus may also be used to assist in the removal of cellulite from areas of the leg. The apparatus is basically comprised of a frame, structure means, a user engagement means, a coupling means, and an optional resistance means. The frame structure means has at least two main support members coupled together in such a manner that the leg of the user may be placed within, with the main support members surrounding a significant portion of the leg. The main support members are adjustably coupled together by the coupling means such that they may alternatively move away and towards one another, as the various leg muscles of the user are being engaged by the user engagement means. The optional resistance means may be used to provide motion resistance.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a display device such as a liquid crystal display device.
[0003] 2. Description of the Related Art
[0004] As an example of a conventional display unit, a conventional liquid crystal display device is illustrated in FIGS. 1 to 10 .
[0005] The conventional liquid crystal display device includes a backlight unit 30 (see FIG. 1), a panel unit 50 (see FIG. 5), and a rear plate 26 (see FIG. 8).
[0006] As illustrated in FIG. 1, the backlight unit 30 is comprised of lamps 15 , light-reflectors 16 , an optical sheet comprised of a lens film 22 and a light-diffusion film 23 (see FIG. 2), a light-reflection film 14 , a light-guide 13 (see FIG. 2), a rear frame 21 , and a front frame 31 (see FIG. 3).
[0007] As illustrated in FIG. 5, the panel unit 50 is comprised of a plurality of flexible substrates 300 on each of which a driver IC is mounted, connector substrates 500 , and signal-processing substrates 400 . The connector substrates 500 and the signal-processing substrates 400 are mechanically and electrically connected to a liquid crystal display panel through the flexible substrates 300 .
[0008] As illustrated in FIG. 6, the panel unit 50 is framed by a front bezel 40 formed centrally with an opening 61 .
[0009] As illustrated in FIG. 8, on the rear plate 26 are mounted a conversion substrate 600 which receives external signals, converts the thus received signals into a desired form, and transmits the converted signals to the signal-processing substrate 400 , an inverter substrate 700 which supplies a desired voltage to the lamps 15 , and circuit substrates (not illustrated).
[0010] As illustrated in FIG. 9, the rear plate 26 is mounted on a rear of a display unit 60 , and as illustrated in FIG. 10, the display unit 60 is fixedly sandwiched between a case front 70 and a case rear 80 . Thus, a liquid crystal display device is completed.
[0011] Japanese Patent Application Publication No. 11-281963 suggests a method of fixing the backlight unit 30 and the panel unit 50 to each other.
[0012] As illustrated in FIGS. 5 and 6, a frame of the backlight unit 30 is formed at an external sidewall thereof with a plurality of hooks 34 for horizontally supporting and positioning a liquid crystal display panel, and the front bezel 40 fixes the panel unit 50 onto the backlight unit 30 .
[0013] Japanese Patent Application Publication No. 9-297542 suggests a method of fixing the display unit 60 .
[0014] In the method, as illustrated in FIGS. 7 to 10 , the display unit 60 is comprised of the backlight unit 30 and the panel unit 50 both connected to each other through the front bezel 40 . The display unit 60 is designed to have such a flange that the display unit 60 is fixedly sandwiched between a front housing as the case front 70 and a rear housing as the case rear 80 .
[0015] FIGS. 1 to 4 illustrate parts constituting the backlight unit 30 and steps of assembling the backlight unit 30 .
[0016] As illustrated in FIG. 1, the light-reflection sheet 14 , the lamps 15 as a light source, and the light-reflectors 16 are all inserted into the rear frame 21 . Each of the lamps 15 is temporarily fixed to the light-reflector 16 by means of a holder rubber 19 , and includes a lamp cable 20 extending from an end of the lamp 15 .
[0017] As illustrated in FIG. 2, the light-guide 13 , the light-diffusion film 23 and the lens film 22 are mounted in this order on the light-reflection sheet 14 fixed in the rear frame 21 .
[0018] Then, as illustrated in FIG. 3, the front frame 31 is fixed onto the rear frame 21 to thereby fix the light-guide 13 , the light-diffusion film 23 and the lens film 22 therebetween. The front and rear frames 31 and 21 are fixed to each other by insertion of the hooks 34 into hook holes 32 formed at an external surface of the front frame 31 , and further by screws 35 .
[0019] Thus, as illustrated in FIG. 4, the backlight unit 30 is completed.
[0020] FIGS. 5 to 7 illustrate parts constituting the display unit 60 and steps of assembling the display unit 60 .
[0021] The front frame 31 is formed with ribs 37 for supporting a liquid crystal display panel. The panel unit 50 is mounted on the backlight unit 30 in dependence on the ribs 37 .
[0022] As illustrated in FIG. 6, the signal-processing substrates 400 and the connector substrates 500 are positioned on a rear of the backlight unit 30 by bending the flexible substrates 300 . As an alternative, the connector substrates 500 may be fixed to sidewalls of the backlight unit 30 by perpendicularly bending the flexible substrates 300 .
[0023] The panel unit 50 mounted on the backlight unit 30 is then fixedly sandwiched between the front bezel 40 and the backlight unit 30 , in which case, the front bezel 40 and the backlight unit 30 are fixed to each other by inserting the hooks 34 of the backlight unit 30 into hook holes 41 of the front bezel 40 , as illustrated in FIG. 7.
[0024] FIGS. 8 to 10 illustrate parts constituting a liquid crystal display device and steps of assembling the same.
[0025] As illustrated in FIG. 9, a power source connector 610 and an interface connector 620 are mounted on the conversion substrate 600 . As illustrated in FIG. 8, the inverter substrate 700 and the conversion substrate 600 are fixed onto the rear plate 26 by means of hooks 27 and screws 24 . The rear plate 26 is fixed on a rear of the display unit 60 , as illustrated in FIG. 9.
[0026] As illustrated in FIGS. 8 and 9, the substrates are electrically connected to one another through connection cables 25 . A backlight cable is electrically connected to the inverter substrate 700 .
[0027] Then, as illustrated in FIG. 10, the display unit 60 on which the conversion substrate 600 and the inverter substrate 700 have been mounted is fixedly sandwiched between the case front 70 and the case rear 80 by insertion of hooks 71 of the case front 70 into hook holes 81 of the case rear 80 , and further by screws 28 . Thus, there is completed a liquid crystal display device.
[0028] As mentioned above, the conventional liquid crystal display device is fabricated as follows.
[0029] First, there are assembled the backlight unit 30 comprised of the lamps 15 , the light-reflectors 16 , the optical sheet 22 - 23 , the light-reflection sheet 14 , the light-guide 13 and the frames 21 and 31 , and the panel unit 50 including a liquid crystal display panel to which the connection substrates 500 and the signal-processing substrates 400 are connected through the flexible substrates 300 . Then, the backlight unit 30 and the panel unit 50 are connected to each other through the front bezel 40 formed with the opening 61 , thereby forming the display unit 60 . Then, the rear plate 26 on which the conversion substrate 600 , the inverter substrate 700 and the circuit substrates are mounted is fixed onto a rear of the backlight unit 30 . Then, the display unit 60 is fixedly sandwiched between the case front 70 and the case rear 80 . Thus, there is fabricated the liquid crystal display device.
[0030] As is obvious in light of the above-mentioned fabrication process of the conventional liquid crystal display device, the conventional liquid crystal display device is accompanied with problems that it has a lot of parts for fabrication, and fabrication process is quite complicated, because the fabrication process includes a plurality of steps of inverting parts or semi-products.
[0031] In addition, an increase in the number of the parts for fabrication of a liquid crystal display device causes difficulty in preparing and delivering parts, and an increase in lead-time necessary for assembling a liquid crystal display device after parts are obtained. As a result, costs for fabrication of a liquid crystal display device are unavoidably up.
[0032] Furthermore, since fabrication error in assembly of the units is accumulated, a resultant liquid crystal display device unavoidably have much reduced accuracy in fabrication.
[0033] The above-mentioned problems are common to a display device other than a liquid crystal display device.
SUMMARY OF THE INVENTION
[0034] In view of the above-mentioned problems in the conventional liquid crystal display device, it is an object of the present invention to provide a display device which can reduce the number of assembling steps for simplifying a fabrication process.
[0035] In one aspect of the present invention, a display device including a display unit for displaying images, and a case in which the display unit is installed, the case being formed with an opening through which the display device is slid into and out of the case.
[0036] It is preferable that the case is formed with a guide for supporting the display unit therewith.
[0037] It is preferable that the case includes a cover for covering the opening therewith, the cover being formed as a part of the case.
[0038] It is preferable that the cover is bendable for having a first position in which the cover does not close the opening, and a second position in which the cover closes the opening.
[0039] The display device may further include a base plate on which the display unit is fixed.
[0040] For instance, the display device is fabricated as an electroluminescence (EL) display device.
[0041] In another aspect of the present invention, there is provided a liquid crystal display device including a liquid crystal display unit for displaying images, and a case in which the liquid crystal display unit is installed, the case being formed with an opening through which the liquid crystal display unit is slid into and out of the case.
[0042] For instance, the liquid crystal display unit may be comprised of a liquid crystal display panel, a first substrate supplying a desired voltage to the liquid crystal display panel, a second substrate supplying a signal voltage to the first substrate, a backlight unit supplying backlight to the liquid crystal display panel, a third substrate acting as an interface, and a fourth substrate supplying a desired voltage to the backlight unit;
[0043] It is preferable that the liquid crystal display unit further includes a base plate on which the liquid crystal display panel is supported, the base plate is formed centrally with a window through which a display area of the liquid crystal display panel is exposed, and the base plate is formed with ribs for supporting the liquid crystal display panel, and a light-guide and a light-reflector both constituting the backlight unit.
[0044] It is preferable that the base plate acts as a guide for the liquid crystal display unit to be slid into and out of the case.
[0045] It is preferable that the opening is closed by bending a part of the case.
[0046] It is preferable that the opening is closed by a cover composed of the same material as that of the case.
[0047] It is preferable that the liquid crystal display panel, the first substrate, the second substrate, the backlight unit, the third substrate and the fourth substrate are stuck on the base plate.
[0048] The advantages obtained by the aforementioned present invention will be described hereinbelow.
[0049] In accordance with the present invention, a display device is simply slid into and out of a case through an opening formed with the case. Thus, it is no longer necessary to carry out steps of inverting parts or semi-products which steps were inevitably carried out in fabrication of the conventional liquid crystal display device, ensuring reduction in the number of fabrication steps.
[0050] In addition, by mounting a liquid crystal display panel, a light-guide and a light-reflector on a base plate, it would be possible to reduce the number of parts in comparison with the conventional liquid crystal display device in which a holder plate is necessary for each of assembly units.
[0051] The above and other objects and advantageous features of the present invention will be made apparent from the following description made with reference to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] FIGS. 1 to 10 are perspective views of a conventional liquid crystal display device, illustrating respective steps in fabrication of the same.
[0053] FIGS. 11 to 17 are perspective views of a liquid crystal display device in accordance with an embodiment of the present invention, illustrating respective steps in fabrication of the same.
[0054] [0054]FIG. 18 is a cross-sectional view taken along the line 18 - 18 in FIG. 16.
[0055] [0055]FIG. 19 is a cross-sectional view taken along the line 19 - 19 in FIG. 16.
[0056] FIGS. 20 to 22 are perspective views of a liquid crystal display device in accordance with an embodiment of the present invention, illustrating respective steps in fabrication of the same.
[0057] [0057]FIG. 23 is a cross-sectional view taken along the line 23 - 23 in FIG. 22.
[0058] [0058]FIG. 24 is a cross-sectional view taken along the line 24 - 24 in FIG. 22.
[0059] [0059]FIG. 25 is a cross-sectional view taken along the line 24 - 24 in FIG. 22, illustrating different state of a liquid crystal display device from a state illustrated in FIG. 24.
[0060] [0060]FIG. 26 is a cross-sectional view taken along the line 26 - 26 in FIG. 22.
[0061] [0061]FIG. 27 is a rear view of an display apparatus including the liquid crystal display device in accordance with an embodiment of the present invention.
[0062] [0062]FIG. 28 is a front view of the liquid crystal display device in accordance with an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0063] FIGS. 11 to 17 and 20 to 22 are perspective views of a liquid crystal display device in accordance with an embodiment of the present invention, illustrating respective steps in fabrication of the same, and FIGS. 18, 19 and 23 to 26 are cross-sectional views of the liquid crystal display device.
[0064] [0064]FIG. 11 illustrates a frame-shaped base plate 100 as a part of the liquid crystal display device. The base plate 100 is composed of plastic resin or metal, and is centrally formed with a rectangular opening 110 through which a display area of the liquid crystal display device can be seen. The base plate 100 is formed with ribs 121 , 122 , 131 , 132 and 133 for positioning and supporting other parts.
[0065] Hereinbelow is explained a fabrication process of the liquid crystal display device with reference to FIGS. 12 to 20 .
[0066] As illustrated in FIG. 12, a resilient and/or adhesive strip 140 is arranged along the rectangular opening 110 of the base plate 100 .
[0067] As illustrated in FIG. 13, the panel unit including the liquid crystal display panel 200 , the signal-processing substrate 400 and the connection substrate 500 both of which are mechanically and electrically connected to the liquid crystal display panel 200 through the flexible substrates 300 is mounted on the base plate 100 with the strip 140 being sandwiched therebetween such that a display area of the liquid crystal display panel 200 can be seen through the opening 110 from a rear of the base plate 100 . The strip 140 absorbs deformation of the base plate 100 to ensure close contact between the liquid crystal display panel 200 and the base plate 100 .
[0068] The liquid crystal display panel 200 is partially supported by the ribs 121 and 122 such that a display screen of the liquid crystal display panel 200 is kept horizontal.
[0069] Since the connector substrates 500 are connected to the liquid crystal display panel 200 through the flexible substrates 300 , when the connector substrates 500 make contact with the ribs 133 , the flexible substrates 300 are made bent, and the connector substrates 500 slide on chamfered rounded tops of the ribs 133 into a gap formed between the ribs 131 and 133 . As a result, the connector substrates 500 are kept perpendicular relative to a display plane of the liquid crystal display device, as illustrated in FIG. 14.
[0070] The liquid crystal display panel 200 is partially supported by the ribs 121 and 122 of the base plate 100 horizontally of a display plane of the liquid crystal display device. Then, a spacer 11 for positioning an optical sheet 12 , an optical sheet 12 and the light-guide 13 are mounted in this order on the liquid crystal display panel 200 .
[0071] Specifically, a plastic spacer 11 having a thickness of about 0.2 to 1.5 mm and a width of about 1.0 to 5.0 mm is fixed onto a rear of the liquid crystal display panel 200 mounted on the base plate 100 . For instance, an adhesive is applied to a surface of the spacer 11 , and then, the spacer 11 is adhered to a rear surface of the liquid crystal display panel 200 . Then, the optical sheets 12 such as a lens sheet for collecting light, and a light-diffusion sheet for diffusing light are mounted in the spacer 11 adhered onto a rear surface of the liquid crystal display panel 200 . Then, the light-guide 13 is arranged on the spacer 11 . Between the liquid crystal display panel 200 and the light-guide 13 is formed a clearance equal to a thickness of the spacer 11 . The optical sheets 12 are mounted within the clearance.
[0072] The ribs 132 are designed to have a distal end formed as a L-shaped hook for supporting the liquid crystal display panel 200 , the light-guide 13 , and the light-reflection sheet 14 all mounted on the base plate 100 . The ribs 132 vertically support the liquid crystal display panel 200 , the light-guide 13 and the light-reflection sheet 14 with the distal ends formed as a L-shaped hook, and horizontally support them with sidewalls thereof. The ribs 132 have a tapered outer sidewall, as illustrated in FIGS. 14 and 15.
[0073] The cold cathode lamps 15 and the light-reflectors 16 for reflecting or collecting light to a desired direction are attached to opposite edges of the light-guide 13 . The light-reflectors 16 are composed of metal or plastic. The light-reflectors 16 in which the lamps 15 are arranged are U-shaped, and are open to the edges of the light-guide 13 .
[0074] Lights emitted from the lamps 15 and reflected from the light-reflectors 16 are introduced entirely into and diffused in the light-guide 13 . As a result, the light-guide 13 act as a surface light source for the liquid crystal display panel 200 .
[0075] The light-reflection sheet 14 is attached to a rear surface of the light-guide 13 for reflecting light back to the light-guide 13 . The light-reflection sheet 14 makes close contact with a surface of the light-guide 13 .
[0076] The light-guide 13 is supported horizontally relative to a display plane of the liquid crystal display panel 200 by the ribs 131 of the base plate 100 .
[0077] As illustrated in FIG. 15, the light-reflectors 16 are partially supported by the ribs 121 and 122 .
[0078] After the light-reflection sheet 14 has been attached to the light-guide 13 , the signal-processing substrates 400 of the panel unit are mounted on a rear surface of the light-reflection sheet 14 by bending the flexible substrates 300 , as illustrated in FIG. 16.
[0079] Then, as illustrated in FIG. 17, a conversion substrate 600 which receives external signals, converts the thus received signals into a desired form, and transmits the converted signals to the signal-processing substrate 400 , and an inverter substrate 700 which supplies a desired voltage to the lamps 15 are mounted on a rear surface of the light-reflection sheet 14 .
[0080] [0080]FIG. 18 is a cross-sectional view taken along the line 18 - 18 in FIG. 16, illustrating that the liquid crystal display panel 200 and the light-reflector 16 are supported by the ribs 121 of the base plate 100 .
[0081] [0081]FIG. 19 is a cross-sectional view taken along the line 19 - 19 in FIG. 16, illustrating that the light-guide 13 and the light-reflection sheet 14 are supported horizontally relative to a display plane 17 of the liquid crystal display panel 200 by the ribs 131 extending upwardly from the base plate 100 . As mentioned earlier, the connector substrates 500 are mounted perpendicularly to the display plane 17 of the liquid crystal display panel 200 in a gap formed between the ribs 131 and 133 .
[0082] As illustrated in FIG. 16, the signal-processing substrates 400 are mounted on a rear surface of the light-reflection sheet 14 by bending the flexible substrates 300 , in which case, the flexible substrates 300 are bent so as to partially surround the optical sheets 12 , the light-guide 13 , the lamp 15 and the light-reflector 16 .
[0083] On a rear surface of the light-reflection sheet 14 are mounted the conversion substrate 600 and the inverter substrate 700 . The conversion substrate 600 and the inverter substrate 700 are electrically connected to the signal-processing substrate 400 through cables 18 , as illustrated in FIGS. 17 and 20. The conversion substrate 600 and the inverter substrate 700 are fixed onto the light-reflection sheet 14 through double-sided adhesive tape having high cushion.
[0084] [0084]FIG. 21 illustrates that a display unit, that is, the base plate 100 on which the above-mentioned various units are mounted is slid into a case 800 through an opening 801 formed at a side of the case 800 . FIG. 22 illustrates that the opening 801 of the case 800 is covered with a cover 820 . FIG. 23 is a cross-sectional view taken along the line 23 - 23 in FIG. 22, illustrating that the display unit is put in the case 800 .
[0085] As illustrated in FIG. 23, the case 800 is formed at an inner surface of a sidewall thereof with a guide 810 by which the display unit is appropriately positioned and along which the display unit is slide into the case 800 through the opening 801 . After the display unit is slid into the case 800 , the guide 810 supports the display unit in the case 800 .
[0086] [0086]FIG. 24 is a cross-sectional view taken along the line 24 - 24 in FIG. 22, illustrating that the display unit is slid into the case 800 through the opening 801 .
[0087] The rib 132 is designed to have a reverse-L-shaped distal end acting as a hook for supporting the light-guide 13 or both of the light-guide 13 and the light-reflection sheet 14 making close contact with a rear surface of the light-guide 13 . The rib 132 supports the light-guide 13 and the light-reflection sheet 14 with its L-shaped distal end in a vertical direction, and has a tapered wall at which the rib 132 makes contact with the cover 820 .
[0088] [0088]FIG. 25 is a cross-sectional view taken along the line 24 - 24 in FIG. 22, illustrating that the opening 801 is closed with the cover 820 after the display unit has been slid into the case 800 through the opening 801 .
[0089] [0089]FIG. 26 illustrates an example of fastening the cover 820 to the case 800 . For instance, as illustrated in FIG. 26, the cover 820 may be fixed to the case 800 in the vicinity of the opening 801 by means of screws 45 .
[0090] As illustrated in FIGS. 24 and 25, the cover 820 is formed as a part of the case 800 . The cover 820 is designed to be able to rotate about a bending center 830 for closing and opening the opening 801 of the case 800 . The bending center 830 is formed thinner than the rest of the case 800 for facilitating rotation of the cover 820 .
[0091] The cover 820 engages to the rib 132 . When the opening 801 of the case 800 is closed with the cover 820 , the cover 820 makes contact with the rib 132 , and then, compresses the rib 132 . As a result, the rib 132 is deformed due to a compressive force exerted by the cover 820 , ensuring that the rib 132 firmly supports the light-guide 13 .
[0092] The cover 820 is designed to have an inner surface at which the cover 820 makes contact with the rib 132 , identical to an outer shape of the rib 132 . As illustrated in FIG. 25, when the cover 820 is closed, the cover 820 surrounds the L-shaped distal end of the rib 132 to enhance a strength of the L-shaped distal end of the rib 132 as a hook.
[0093] As illustrated in FIGS. 22 and 26, the cover 820 is fixed to the case 800 by the screws 45 , in which case, the L-shaped distal end of the rib 132 may be fixed in position also by the screws 45 .
[0094] The rib 132 makes contact at the tapered sidewall thereof with the cover 820 . Due to a compressive force exerted by the cover 820 , the rib 132 is deformed, and hence, the L-shaped distal end of the rib 132 firmly compresses the light-guide 13 and the light-reflection sheet 14 . As illustrated in FIG. 26, the cover 820 is formed with through-holes 46 through which the screws 45 are inserted. The L-shaped distal end of the rib 132 is fixed to the case 800 by the screws 45 , which ensures that the L-shaped distal end of the rib. 132 more firmly compresses the light-guide 13 and the light-reflection sheet 14 .
[0095] The liquid crystal display device having been assembled in the above-mentioned way is further assembled into a display apparatus 1 illustrated in FIGS. 27 and 28 wherein FIG. 27 is a rear view and FIG. 28 is a front view. The display apparatus 1 is supported with a stand 2 . An AC adapter 3 or a voltage transformer for feeding power to the display apparatus 1 is electrically connected to the display apparatus 1 , and an image-signal transmitter 4 is electrically connected to the display apparatus 1 through a cable 5 .
[0096] For instance, the image-signal transmitter 4 is comprised of a personal computer. Image-signals transmitted from the image-signal transmitter 4 are input into the conversion substrate 600 in the display apparatus 1 through the cable 5 . A voltage transformed from a domestic voltage by the AC adapter 3 is input into the conversion substrate 600 . The conversion substrate 600 converts the thus received image-signals into drive signals, and further, the received voltage into a voltage suitable for driving the inverter substrate 700 . The inverter substrate 700 drives the lamps 15 for making a surface light source in the light-guide 13 .
[0097] The conversion substrate 600 supplies desired voltage and signals to the signal-processing substrate 400 , which then supplies desired voltage and signals to the driver ICs to thereby drive the liquid crystal display panel 200 in the display apparatus 1 .
[0098] In the above-mentioned embodiment, a liquid crystal display device is selected as an example of a display device. The present invention may be applied to other planar displays such as an organic electroluminescence (EL) display.
[0099] While the present invention has been described in connection with certain preferred embodiments, it is to be understood that the subject matter encompassed by way of the present invention is not to be limited to those specific embodiments. On the contrary, it is intended for the subject matter of the invention to include all alternatives, modifications and equivalents as can be included within the spirit and scope of the following claims.
[0100] The entire disclosure of Japanese Patent Application No. 2002-240174 filed on Aug. 21, 2002 including specification, claims, drawings and summary is incorporated herein by reference in its entirety.
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A liquid crystal display device includes a liquid crystal display unit for displaying images, and a case in which the liquid crystal display unit is installed, the case being formed with an opening through which the liquid crystal display unit is slid into and out of the case.
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FIELD OF THE INVENTION
The present invention relates to a guide device for a connection element.
BACKGROUND OF THE INVENTION
A device of this general type is known from the European Patent Application No. EP-A2-0 297 033.
SUMMARY OF THE INVENTION
It is the object of the invention to create a different type of guide device than the device disclosed in the above-mentioned European Patent Application.
The present invention provides a guide device for a connection element including a bolt which by means of a sleeve insert, can be rotatably fastened to an end of a rod. The bolt is connected slidably axially to the front part of a guide sleeve so that rotary movement of the guide sleeve can be transmitted to the bolt. A bell-shaped flange is at a rear part of the guide sleeve which serves to define an inside space which is dimensioned as that a head of the sleeve insert can be disposed therein.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in greater detail by a description of exemplified embodiments with reference to the drawings; wherein:
FIGS. 1 to 3 show diagrammatic sectional views of various connection elements with various variants of the device according to the invention, and
FIGS. 4 and 5 show views of a guide insert for the guide sleeve according to FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The connection element according to FIG. 1 comprises a sleeve insert 3 consisting of a flange-shaped sleeve head 1 and a tubular part 2, wherein the tubular part 2 is provided with an external thread 4 for fastening it to one end of a rod of a three-dimensional framework. A bolt 5 is guided through a through-bore of the sleeve insert 3, the head 6 of the bolt 5 resting on the end wall of the tubular part 2.
The bolt 5 has an elongated, round, smooth part 7 and an end part 8 which is provided with an external thread 9 for fastening the bolt to a guide insert 10 (FIG. 4).
FIG. 4 shows a side sectional view transversely to the longitudinal axis of the guide insert 10 with a threaded part 11 which serves to screw it onto a junction part.
The guide insert 10 has on one side thereof a hexagonal part 12 (FIG. 5) with a threaded bore 13, into which the threaded bolt can be screwed. Approximately in the middle of the shell of the guide part 12, a perpendicular threaded hole 14 is provided, through which a threaded pin 15 shown in FIG. 1, e.g. a hegaxonal socket pin, can be screwed on to guide the guide insert 10 in the assembled state.
The bolt 5 is guided through the through-bore of a guide device or guide sleeve 16, from which the threaded part 11 of the guide insert 10 projects. At the front part of the guide sleeve 16 this through-bore is shaped complementally to the guide part 12, so that a rotary movement of the guide sleeve 16 can be transmitted to the threaded part 11 with as little play as possible.
The through-bore of the front part of the guide sleeve 16 can, therefore, also be polygonal, the same as the guided part of the guide insert. However, these cross-sections are preferably hexagonal, as illustrated in FIGS. 4 and 5. In contrast thereto the guide sleeve 16 is, in its rear part, made flange-shaped towards the outside and rear, to form an approximately bell-shaped flange 17, in the inside space 18 of which the sleeve head 1 can be accommodated. As shown in FIG. 1, the flange 17 includes a bevel 17', and a height h is more than half (50%) of the total height H. In addition, the guide sleeve 16 has in its rear part a radially arranged ring-shaped wall 19, wherein in the inside space of the guide sleeve 16 between the wall 19 and the guide insert 10 a coil spring 20 is arranged around the bolt 5, which spring 20 presses the guide insert 10 and the bolt 5 connected thereto forwards. Further, guide sleeve 16 includes an inside space 18'.
The maximum outside diameter of the flange 17 is preferably the same as the outside diameter of the rod 21 to be connected by the connection element, so as to obtain a pleasing aesthetic effect, and the minimum inside diameter of the flange 17 in the bell-shaped space is greater than the maximum cross-section of the sleeve head 1, which preferably is not round, so that it can be screwed onto the rod 21 by means of a spanner. The diameter of the bore of the ring-shaped wall 19 is larger than the diameter of the bolt 5 and smaller than the diameter of the coil spring 20. The sleeve 16 according to FIG. 1 has an opening 22, through which the pin 15 is guided.
The mode of operation of the element according to FIG. 1 is basically known from the European Patent Application No. 297.033 with the difference that according to the present invention in its rear part, the guide sleeve 16 is constructed differently. The flange-shaped construction has the advantage that the transition between the end of the rod 21 and the sleeve 16 can be realized harmonically, and this in various variants, as, for example, on the outside the front part of the guide sleeve 16 may be hexagonal and the flange 17 round.
The connection element according to FIG. 2 corresponds essentially to the embodiment of FIG. 1, wherein for identical parts the same reference numerals are used. However, with this embodiment the guide device or sleeve 16' does not have an opening in its shell.
The connection element according to FIG. 3 has a few characteristics in common with the embodiment of FIG. 1, and also here the same reference numerals are used for identical parts. The connection element according to FIG. 3 comprises, in particular, also a sleeve insert 3 consisting of a sleeve head 1 and a tubular part 2, wherein the tubular part 2 is provided with an external thread 4. Through a through-bore of the sleeve insert 3 a bolt 5' is guided, the head 6 of which rests on the end face of the tubular part 2.
The bolt 5' has an elongated, round, smooth part 7', a guide part 23, the cross-section of which may be polygonal, and an end part 9' which is provided with an external thread 9". To simplify the drawing, the junction part 24 and the rod 25 are indicated only by broken lines.
The bolt 5' is guided through the through-bore of a guide sleeve 26, from which the end part 9' projects. In the front part of the guide sleeve 26 this through-bore is shaped complementally to the guide part 23 of the threaded bolt 5', so that a rotary movement of the guide sleeve 26 can be transmitted to the bolt 5' with as little play as possible.
The through-bore of the front part of the guide sleeve 26 can, therefore, also be polygonal, the same as the guided part of the bolt 5'. However, preferably these cross-sections are hexagonal. In contrast thereto the through-bore has in the rear part of the guide sleeve 26 a preferably round cross-section, in which case there occurs between the round part 7' of the bolt 5' and the preferably cylindrical inside wall of the guide sleeve 26 a relatively large gap, to form an open space in which a coil spring 27 can be accommodated.
In the shell of the guide sleeve 26 an elongated opening 22 may be provided through which a pin 15 can be loosely inserted and connected to the bolt 5', preferably radially in its guide part 8.
The spring 27 is arranged in the gap in such a way that at its end on the right it rests on a bush 28 having a cylinder part 28' and a flange part 28" and at its end on the left it rests on the pin 15 to press it forward and with this push the end part 9' out of the guide sleeve 26, when it is, for example, pushed by hand into the guide sleeve 26. The transmitting of the rotary movement is ensured by the shape of the front part of the guide sleeve 26. On the other hand the pin 15 is provided so that the bolt 5' can be pushed with the fingers along the elongated opening 22 against the action of the spring 27.
With this embodiment the bell-shaped flange 29 is separate from the actual guide sleeve 26, and the bush 28 is provided to fasten the flange 29 to the guide sleeve 26, e.g. by screwing or by a bayonet connection. In this case the flange 29, the bush 28 and the guide sleeve 26 form the guide device for the connection element.
The embodiment according to FIG. 3 has the property that the spring 27 no longer remains constantly clamped-in in the sleeve 26 if this is closed off, e.g. by screwing on the bush 28. The spring 27 can, therefore, easily be removed from the sleeve 26. This property is often desirable so that the spring 27 can be replaced more easily. In addition to this advantage, the connection element of FIG. 3 has the further advantage that due to the bell-shaped flange 29 a well matching transition can be realized between the rod 25 and the guide sleeve 26. This embodiment can be made without any opening 22 whatsoever in the shell of the guide sleeve 26, as it can be dismantled very easily. Instead of the pin, a projection of the bolt in the parts 7 and/or 23 could be provided, in which case the opening 22 could also be provided right up to the rear end of the guide sleeve 26.
In a further development of the invention, the flange 29 could form an integral part with the rear end of the guide sleeve 26.
In a further development of the invention, the flange 29 could form an integral part with the bush 28.
Finally, it must still be pointed out that instead of a coil spring it is also possible to use a spring that is put on from the side, e.g. a meander-shaped spring, and that with a view to maintaining the tolerances the flange ring and/or the sleeve may also be made from die cast metal, e.g. as bronze or zinc die castings.
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A guide device including a bolt (5) which through a sleeve insert can be fastened rotatably to one end of a rod (21), which bolt is connected, sliding axially, to the front part of a guide sleeve (16') in such a way that a rotary movement of the guide sleeve (16') can be transmitted to the bolt (5). A spring (20) pushes the bolt (15) out of the guide sleeve (16'), and the rear end of the guide sleeve (16') an approximately bell-shaped flange (17) is provided, which delimits an inside space which is dimensioned such that the head (1) of the sleeve insert can be accommodated therein.
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FIELD OF THE INVENTION
The present invention pertains to data processing, database and file management or data structures and, more particularly, query augmenting or refining.
BACKGROUND OF THE INVENTION
Many prior methods of identifying and highlighting text in a document rely on syntactic or semantic parsing methods, or probabilities, or string matching.
Generally, parsing methods are slow and fail, or degrade, dramatically given less than highly structured text. Many parsers work well for highly structured prose found in newspapers but do not work well on less structured text.
Probabilistic methods such as those used in Hidden Markov Models require substantial training sets and, generally, are not very accurate.
String matching on large lists generally require substantial storage capacity and are either limited to recognizing specific spellings or are slow if not so limited.
Therefore, there is a need for a more accurate and faster method of identifying text and highlighting the same. The present invention is such a method.
U.S. Pat. No. 5,287,278, entitled “METHOD FOR EXTRACTING COMPANY NAMES FROM TEXT,” discloses a method of identifying a name of a company by first locating its suffix (i.e., Company, Corporation) and then locating the beginning of the company's name. The present invention is not limited to using suffixes, and uses additional steps not disclosed in U.S. Pat. No. 5,287,278. U.S. Pat. No. 5,287,278 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 5819,265, entitled “PROCESSING NAMES IN A TEXT,” discloses a device for and a method of identifying a proper name in text by identifying capitalized words and specially designated words. Then, leading and trailing substrings (e.g., spaces, punctuation) are removed. Then, the identified word is split, if possible, until it cannot be split any further. The result is a list of possible proper names. The present invention does not use the same method as does U.S. Pat. No. 5,819,265 and includes steps that are not disclosed in U.S. Pat. No. 5,819,265. U.S. Pat. No. 5,819,265 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 5,832,480, entitled “USING CANONICAL FORMS TO DEVELOP A DICTIONARY OF NAMES IN A TEXT,” discloses a device for and a method of creating canonical forms of a proper name in text by first establishing an equivalence group where each name, which was identified using the method of U.S. Pat. No. 5,819,265, shares an attribute (e. g., professional title, suffix, last name, personal title, first name, prefix, nickname, organization place, organization tag, organization name). Then, selecting the name with a high confidence score as an anchor. Then, designating one or more names that share an attribute with the anchor as a variant of the anchor. The present invention does not use the same method as does U.S. Pat. No. 5,832,480 and includes steps that are not disclosed in U.S. Pat. No. 5,832,480. U.S. Pat. No. 5,832,480 is hereby incorporated by reference into the specification of the present invention.
SUMMARY OF THE INVENTION
It is an object of the present invention to identify user-definable text in a document and highlight the same.
It is another object of the present invention to identify user-definable text in one language in a document of another language and highlight the same.
It is another object of the present invention to identify, independent of the character case, user-definable text in one language in a document of another language and highlight the same.
The present invention is a method of identifying textual units (e. g., names) in a document and highlighting the same using a computer.
The first step of the method is receiving text.
The second step of the method is identifying each token in the text.
The third step of the method is selecting a token.
The fourth step of the method is determining if the token includes a user-definable prefix, user-definable root, user-definable suffix, user-definable disqualified textual unit, and the token's length.
The fifth step of the method is replacing each identified prefix, root, and suffix with a standard form of the same.
If there is an unselected token then the sixth step of the method is selecting the token next in sequence and returning to the fourth step.
The seventh step of the method is reselecting the token selected in the third step.
If the reselected token does not start a user-definable textual unit then the eighth step of the method is printing the reselected token in a first font, reselecting the token next in sequence and returning to the eighth step, and if no token to reselect then stopping.
If the reselected token does start a user-definable textual unit then the ninth step of the method is marking the reselected token for highlighting, reselecting the token next in sequence, and if no token to reselect then printing in the second font the reselected token marked for highlighting and stopping.
If the token reselected in the last step is an end-of-textual-unit indicator then the tenth step of the method is printing in the second font the reselected token marked for highlighting except tokens marked as loose tokens, printing tokens marked as loose tokens in the first font, and returning to the eighth step.
If the token reselected in the ninth step is not an end-of-textual-unit indicator then the eleventh step of the method is determining if the reselected token marked for highlighting can include an additional token.
If the reselected token marked for highlighting can include an additional token then the twelfth step of the method is determining if the reselected token can be concatenated to the reselected token marked for highlighting.
If the reselected token marked for highlighting can include an additional token and the reselected token cannot be concatenated to the reselected token marked for highlighting without qualification then the thirteenth step of the method is marking the reselected token as a loose token, concatenating the reselected token to the reselected token marked for highlighting, reselecting token next in sequence and returning to the tenth step, and if no token to reselect then printing in the second font the reselected token marked for highlighting except for any reselected token marked as a loose token, and printing in the first font any reselected token marked as a loose token and stopping.
If the reselected token marked for highlighting can include an additional token and the reselected token can be concatenated to the reselected token marked for highlighting without qualification then the fourteenth step of the method is concatenating the reselected token to the reselected token marked for highlighting, removing the loose token mark from any reselected token so marked, reselecting token next in sequence and returning to the tenth step, and if no token to reselect then printing in the second font the reselected token marked for highlighting and stopping.
If the reselected token marked for highlighting cannot include an additional token then the fifteenth step of the method is printing in the second font the reselected token marked for highlighting except any reselected token marked as a loose token, printing in the first font any reselected token marked as a loose token, and returning to the eighth step.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a list of the steps of the present invention.
DETAILED DESCRIPTION
The present invention is a method of identifying user-definable textual units and highlighting the same using a computer. The steps of the method are listed in FIG. 1 .
The first step 1 of the method is receiving text on a computer. The received text may be from one or more documents, or may be provided in query form. In the preferred embodiment, the text is in a first language, where the user-definable textual units of interest (e.g., names, places, things, events, time periods, results) are transliterated into the first language from a second language.
The second step 2 of the method is identifying each token in the text. In the preferred embodiment, a token is an alpha-numeric string that may include leading spaces and leading punctuation. The alpha-numeric portion of a token is referred to as a “word,” whereas a leading space, leading punctuation, end-of-line indicator (i. e., carriage return), and any combinations thereof is referred to as a “pre-word.” However, any other suitable non-textual information may be included in the pre-word. In an alternate embodiment, the characters of each token may be converted to all one case (i.e., upper case or lower case).
The third step 3 of the method is selecting a token. In the preferred embodiment, the first token selected is the first token in the text. However, any token may be selected as the first token. Thereafter, the tokens are selected in sequence or, in other words, order of occurrence.
The fourth step 4 of the method is determining if the token includes a prefix, root, suffix, disqualified textual unit, and what is the token's length. In the preferred embodiment, the prefix, root, and suffix are user-definable (e.g., from a dictionary) and are transliterated prefixes, roots, and suffixes from a different language than that of the text in which the token appears. However, the method of the present invention works equally well on text that includes prefixes, roots, and suffixes in the same language as that of the text. The disqualified textual unit is also user-definable and preferably consists of a word in the language of the text that is irrelevant to the type of textual unit to be highlighted. For example, if names are to be highlighted then disqualified textual units include words in the language of the text that are not names. A user-definable list of stop-words in the language of the text may also be included as disqualified textual units. A dictionary may be established for either or both types of disqualified textual units.
The fifth step 5 of the method is replacing each identified prefix, root, and suffix with a standard form of the same. The fifth step 5 accounts for any variation in the type of text that is possible (e.g., Joe for Joseph, 3M for Minnesota Mining and Manufacturing).
If there is an unselected token then the sixth step 6 of the method is selecting the token next in sequence and returning to the fourth step 4 . Otherwise, proceeding to the next step. The present invention requires the tokens be processed in order once the first token is selected, which may be the first, or user-definably placed, token in the text.
After the tokens of interest are processed a first time to determine their content and such, they are processed a second time as follows.
The seventh step 7 of the method is reselecting the first token selected in the third step 3 .
If the token reselected in the seventh step 7 does not start a user-definable textual unit then the eighth step 8 of the method is printing the reselected token in a first font, reselecting the token next in sequence and returning to the eighth step 8 , and if no token to reselect then stopping. A token is determined to start a textual unit if it satisfies the following logical relationship: (the token includes a user-definable root OR the token includes a user-definable prefix) AND (the token does not include a user-definable disqualified textual unit) AND (the token does not include less than two characters). In the preferred embodiment, the first font is the same as that of the token as received in the first step 1 .
If the reselected token does start a user-definable textual unit then the ninth step 9 of the method is marking the reselected token for highlighting, reselecting the token next in sequence, and if there are no tokens to reselect then printing in a second font the reselected token marked for highlighting and stopping. In the preferred embodiment, the second font is a font selected from the following list of fonts: bolded, underlined, colored, italicized, superscripted, subscripted, hyperlinked, and any other suitable font. In an alternate embodiment, multiple second fonts (e.g., bold and even more bold) may be used to indicate different degrees of highlighting (e.g., weak, strong, very strong, etc.). Varying degrees of highlighting may be based on the number of characters or elements in the textual unit to be highlighted or on a user-settable strength rating of user-definable characters or elements in the textual unit to be highlighted.
If the token reselected in the last step is an end-of-textual-unit indicator then the tenth step 10 of the method is printing in the second font the reselected token marked for highlighting except any reselected token marked as a loose token, printing loose tokens in the first font, and returning to the eighth step 8 . End-of-textual-unit indicators are a function of the type of text to be highlighted. For example, if personal and company names are to be highlighted then indicators such as “AKA,” “formerly,” “Company,” and “Incorporated” would be good end-of-textual-unit indicators, In the preferred embodiment, the end-of-textual-unit indicators could be transliterated from a language other than the language of the text. In the preferred embodiment, an end-of-textual unit indicator is a token that satisfies the following logical relationship: (the token is a number OR (the token is a user-definable disqualified word) OR (the token includes a user-definable condition, where the user-definable condition includes having more than one line-indicator)). A user-definable disqualified word includes one that satisfies the following logical relationship: (the token is longer than 6 characters OR the token is (longer than 10 characters AND ends in “ed”)) OR (the token is an end-of-textual-unit indicator) OR (the token includes a space OR includes punctuation).
If the token reselected in the ninth step 9 is not an end-of-textual-unit indicator then the eleventh step 11 of the method is determining if the reselected token marked for highlighting can include an additional token. A token is determined to not be able to include an additional token if it satisfies the following logical relationship: (the number of loose tokens in the token to be highlighted is less than a user-definable number AND the number of loose tokens in the token to be highlighted that are user-definable disqualified textual units is below a user-definable number AND (the token does not include a new-line indicator OR the token is below 80 characters in length)). A user-definable disqualified textual unit includes a textual unit that is recognizable as a known word in the main language of the document in which it appears.
If the reselected token marked for highlighting can include an additional token then the twelfth step 12 of the method is determining if the reselected token can be concatenated to the reselected token marked for highlighting. A token can be concatenated to another token if it satisfies the following logical relationship: ((the word portion of the token includes only alphabetic characters AND the token follows a prefix other than the character “a”) OR ((the word portion of the token is not a user definable disqualified word) AND ((the token includes a user-definable root) OR (the token includes a user-definable prefix AND (the token directly follows a token not identified as loose OR is not the character “a” OR the token does not directly follow a disqualified word)) OR (the word portion of the token is a user-definable suffix AND the token directly follows a token that is not marked as a loose token))) OR (the token reselected includes two open parentheses)).
If the reselected token marked for highlighting can include an additional token and the reselected token cannot be concatenated to the reselected token marked for highlighting without qualification then the thirteenth step 13 of the method is marking the reselected token as a loose token, concatenating the reselected token to the reselected token marked for highlighting, reselecting token next in sequence and returning to the tenth step 10 , and if no token to reselect then printing in the second font the reselected token marked for highlighting except for any reselected token marked as a loose token, printing in the first font any reselected token marked as a loose token, and stopping.
If the reselected token marked for highlighting can include an additional token and the reselected token can be concatenated to the reselected token marked for highlighting without qualification then the fourteenth step 14 of the method is concatenating the reselected token to the reselected token marked for highlighting, removing the loose token mark from any reselected token so marked, reselecting token next in sequence and returning to the tenth step 10 , and if no token to reselect then printing in the second font the reselected token marked for highlighting and stopping.
If the reselected token marked for highlighting cannot include an additional token then the fifteenth, and final, step 15 of the method is printing in the second font the reselected token marked for highlighting except any reselected token marked as a loose token, printing in the first font any reselected token marked as a loose token, and returning to the eighth step 8 .
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The present invention is a method of identifying and highlighting textual units of interest using a computer. Text is received and tokens therein are identified. Prefixes, suffixes, and roots are identified and replaced with their standard forms. Starting and continuing tokens of textual units of interest are identified and printed in a user-defined font. The other tokens are printed in another user-defined font.
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FIELD OF THE INVENTION
The present invention relates to a rolling bearing, and more particularly to a rolling bearing suitably used for, for example, information instruments such as a hard disc device (HDD), a video tape recorder (VTR), a laser printer, etc.
BACKGROUND OF THE INVENTION
Hitherto, as, for example, a roller bearing for supporting a spindle motor of hard disc devices, a roller bearing wherein the bearing ring and rolling element are formed with a ball bearing steel, etc., has become the main current.
In the above-described hard disc device, to prevent the occurrence of writing errors and reading errors, the improvement of the acoustic characteristics such as vibrations, noises, etc., has been required.
Also, because these information instruments are frequently placed near users at a relatively calm place in an office, a home, etc., it is strongly desired to reduce the generation of noises, particularly, having the frequency of the audible range of a human.
Under such circumstances, to quiet a rolling bearing for supporting spindle motor, it has been carried out to reduce the shape errors of each constituting element as small as possible, such as, for example, to improve the out of roundness of inner and outer rings and to equalize the sizes of all rolling elements used.
In addition, when the constituting elements of a rolling bearing are composed of a ball bearing steel, generally a heat treatment such as hardening, tempering, etc., is applied to the elements to control such that the residual austenite amount becomes about 10%.
Now, in the above-described conventional counterplan, there is a definite limit and thus further improvement has become necessary. Also, under the circumstance that the lubricating condition is severe, a rolling bearing is liable to generate heat as well as fine impressions, cracks, peelings, etc., are liable to form on the rolling elements and the bearing rings, whereby the caustic characteristics such as vibrations, noises, etc., are reduced.
Also, as the result of investigations, it has been confirmed that one of the causes of generating noises of a rolling bearing is the fine scratches formed on, in particular, rolling elements. On the other hand, recently, there are rolling elements formed with a ceramic material which is hard to be scratched. When the rolling element is formed with a ceramic material, the generation of noises by scratches can be restrained as well as because the material of the rolling element differs from the material of a bearing ring (steel-made), the effect of preventing sticking by coagulation of them by the inferior lubricant can be obtained.
As described above, the formation of rolling elements with a ceramic material is effective for improving the acoustic characteristics of a ball bearing but by the inventor's further investigations. It has been found that there remains the following point to be solved.
That is, when a rolling element is formed with a ceramic, because the rigidity of the rolling element is increased and the rolling element is hard to deform, the contact area of the rolling element and the bearing ring becomes small and the stress applied to the orbital surface becomes large. Accordingly, when the bearing ring is formed with a conventional ball bearing steel wherein the residual austenite amount is about 10%, the contact portion with the bearing element is liable to cause a permanent deformation and impressions form to generate vibrations and noises to deteriorate the caustic characteristics. Also, when a stress applied to the orbital surface becomes large, there is a problem that austenite is liable to cause a martensite transformation. Furthermore, in the case of using a ball bearing steel wherein the residual austenite amount is about 10%, there is a problem that the amount of the generated heat by the martensite transformation caused at raising the bearing temperature becomes large.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a rolling bearing excellent in the caustic characteristics such as vibrations, noises, etc.
Other object of the present invention is to provide a rolling bearing capable of stably and continuously giving excellent caustic characteristics for a long period of time even under the circumstances of severe lubricating condition.
Still other objects, the features, and the merits of the present invention will become clear from the following descriptions.
That is, a 1st aspect of the present invention is a rolling bearing comprising a bearing ring formed with a steel material and a rolling element formed with a ceramic material, wherein the residual austenite amount of the steel material forming the bearing ring is not more than 8%.
Furthermore, a 2nd aspect of the present invention in a preferred embodiment is a rolling bearing of the 1st aspect wherein the residual austenite amount of the steel material forming the bearing ring is from 0.05% to 6%.
In addition, if the residual austenite amount (γ R ) is less than 0.05%, the crack proceeding speed becomes fast caused by greatly lowering the tenacity to lower the life. On the other hand, if the residual austenite amount exceeds 8%, the permanent deformation amount of the orbital surface by a load (a static load and an impact load) from outside is increased and scratches and impressions are liable to form. From the view point, the critical value of the residual austenite (γ R ) is specified as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects as well as advantages of the present invention will become clear by the following description of preferred embodiments of the present invention with reference to the accompanying drawings, wherein:
FIG. 1 is a cross-sectional view of the upper half of a preferred embodiment of the rolling nearing of the present invention,
FIG. 2 is a graph showing the change of the vibration of the rolling bearing of FIG. 1 with the passage of time, and
FIG. 3 is a cross-sectional view showing an using example of the rolling bearing of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Then, the preferred example of the rolling bearing of the present invention is explained by referring to the accompanying drawings.
First, a preferred example of the rolling bearing of the present invention is explained by referring to FIG. 1 to FIG. 3 .
The rolling bearing A according to the preferred example of the present invention is a deep groove ball bearing. The rolling bearing A is constituted by an inner ring 1 , an outer ring 2 , plural rolling elements 3 , and a retainer 4 . Also, the inner ring 1 and the outer ring 2 are formed with a metal material, the rolling elements 3 are formed with a ceramic material, and the retainer 4 is formed with a synthetic resin material, etc.
Practically, the inner ring 1 and the outer ring 2 are prepared by, after shaping the forms using a ball bearing steel (JIS Standard SUJ 2), applying a series of heat treatments such as a hardening treatment, a sub-zero treatment, a tempering treatment, whereby the residual austenite amount (γ R ) is controlled to become from 0.05 to 6%, and thereafter, by applying thereto a finishing treatment such as polishing, etc. The above-described hardening treatment is the treatment of holding for several tens minutes at 850° C. and thereafter oil-cooling. The sub-zero treatment is the treatment of holding for from several tens minutes to several hours at −70° C. and thereafter air-cooling. And the tempering treatment is the treatment of holding for several tens minutes to several hours at 220° C. and thereafter air-cooling. For example, when in the hardening treatment, after holding for 10 minutes at about 850° C., oil-cooled, in the sub-zero treatment, after holding for 1 hour at −70° C., air-cooled, and in the tempering treatment, after holding for 1 hour at 220° C., air-cooled, the residual austenite amount (γ R ) can be controlled to 2%. The region of the residual austenite is a surface portion, for example, is the portion from the surface to a depth of about 10 μm, and also the surface hardness is established to be from 60 to 64 in HRC. In addition, as the material for the inner ring 1 and the outer ring 2 , in addition to the above-described material, JIS standard SUS440 and various ball bearing steels obtained by improving the above-described JIS standard SUJ2 may be used.
The rolling elements 3 can be formed with ceramics made up of silicon nitride (Si 3 N 4 ) as the main body and using yttria (Y 2 O 3 ) and alumina (Al 2 O 3 ), and further aluminum nitride (AlN), titanium oxide (TiO 2 ), and spinel (MgAl 2 O 4 ) as sintering aids, and also can be formed with ceramics using alumina (Al 2 O 3 ), siliconcarbide (SiC), zirconia (ZrO 2 ) aluminumnitride (AlN)), etc.
Practically, it is preferred that the rolling elements 3 are formed with a ceramic made up of from 1.5 to 5.5% weight yttria (Y 2 O 3 ), from 1 to 2% by weight aluminum nitride (AlN), from 2 to 4.5% by weight alumina (Al 2 O 3 ), from 0.5 to 1.0% by weight titanium oxide (TiO 2 ), and rest being silicon nitride (Si 3 O 4 ). Also, when the rolling element 3 is a ball having a diameter of 2 mm, it is preferred that the precision is JIS Standard B1501-G3 as shown in or higher following Table 1.
TABLE 1
Surface
Diameter
Diameter
roughness
difference
unequal
Sphericity
Ra
of rots
Class
Largest
Largest
Largest
Largest
3
0.03
0.03
0.002
0.05
5
0.08
0.08
0.004
0.14
In the above table, the unit is μm.
The retainer 4 can be formed with a general polyamide resin (nylon 66) or other thermoplastic resins having a heat resistance, for example, fluorine-based resins such as polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), etc., and engineering plastics such as polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polyether sulfone (PES), nylon 46, etc. In addition, in the use under a low-temperature circumstance at about room temperature and under a right-load condition, polypropylene (PP) or polyethylene (PE) can be used. Also, as the form of the retainer 4 , in addition to the crown form shown in FIG. 1, a wave form, etc., is optionally used.
In the above-described rolling bearing A according to the preferred practical example of the present invention, the orbital surfaces of the inner ring 1 and the outer ring 2 have a proper hardness and also a proper tenacity and have a stable structure that the residual austenite is hard to cause a martensite transformation. Also, the work scratches on the surface of the rolling element 3 are less than those of a steel-made rolling element and the rolling movement of the rolling elements 3 becomes smooth.
In particular, when the rolling elements 3 are formed with a ceramic, the contact surface pressure becomes large but by constructing the inner ring 1 and the outer ring 2 as described above, fine impressions, cracks, peelings, etc., are hard to form on the inner and outer rings 1 and 2 , whereby the occurrence of the surface scratches with the passage of time is restrained.
Moreover, because the material of the inner and outer rings 1 and 2 differs from the material of the rolling elements 3 , even in the circumstance of severe lubricating condition and the circumstance that the rolling elements 3 become rolling contact with slipping, the surface scratches of the inner and outer rings 1 and 2 and the rolling elements 3 by sticking by aggregation as the conventional case of using a same metallic material for these parts become hard to occur. That is, the scratch-retraining effect of the inner and outer rings 1 and 2 and the rolling elements 3 is greatly improved as compared with the conventional cases and also the dimensional changes of the inner and outer rings 1 and 2 are retrained, whereby the rolling movement of the rolling elements 3 can be smoothly maintained.
From the above-described improvements, the acoustic characteristics such as vibrations and noises of the rolling bearing A can be stabilized for a long period of time at a low value.
The acoustic characteristics of the rolling bearing A practically determined are explained using FIG. 2 . Although not shown in the figure, the test was carried out in the state that an axis is support in the inside wall of an outer cylinder via a pair of two sample bearings. As the above-described bearings, the roller bearings described above as the preferred practical example were used and as a comparative example, rolling bearings wherein the inner and outer rings and the rolling elements were formed with a ball bearing steel which was subjected to a hardening treatment and a tempering treatment were used.
The sample bearing is call no. 695 of JIS Standard, the pressurization is 1.5 kgf, and the outer ring rotation is 72—rpm. The lubricating state is an oil dropped lubrication (1 mg, viscosity 14 cst at 40° C.
The acoustic value is almost same at the initial value in the preferred example of the present invention and the comparative example but in the case of the comparative example, the acoustic value rapidly increased after 800 hours and in the case of the preferred example of the present invention, the test was stopped after 1400 hours but the value is almost same as the initial value. As described above, in the preferred example of the present invention, the acoustic characteristics such as vibrations and noises can be stabilized for a long period of time at a low value.
The rolling bearing A according to the preferred example of the present invention described above can be used for supporting a spindle motor of a hard disc device as shown in FIG. 3 . In FIG. 3, the numeral 50 shows a spindle motor for HDD and a rotor hub 51 to which a discs 53 are fixed is rotatably supported via a pair of rolling bearings A, A to a motor spindle 52 to which a stator 51 is fixed.
In this case, an excellent calmness can be maintained such that the rotary shaking of the motor spindle 52 can be reduced as small as possible and the occurrence of the vibrations and the noises of the rolling bearings A, A can be restrained. Thus, the rolling bearing of the present invention can largely contribute to the prevention of the occurrences of the writing errors of information to the disc 53 and the reading errors of information from the disc 53 .
In addition, the rolling bearing of present invention can be utilized for not only a spindle motor for HDD but also a video tape recorder and a laser bean printer, the support of the rotary portions by the rolling bearing is stabilized, and thus, the rolling bearings of the present invention can contribute to the improvement of the performance.
While there has been described what is at present considered to be preferred embodiment of this invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of this invention.
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A rolling bearing composed of a combination of bearing wings formed with a steel material and rolling elements formed with a ceramic material, wherein the residual austenite amount of the steel material forming the rolling rings is controlled to a specific value. By the construction, at rolling of the rolling elements formed with a relatively hard ceramic material, the occurrence of the surface scratches of the rolling elements can be restrained, which results in restraining the vibrations and noises caused from the rolling bearing.
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TECHNICAL FIELD
[0001] The present invention generally relates to systems and methods for purging super heated air contained within a passenger compartment of an automobile.
BACKGROUND
[0002] The air contained within the interior of a vehicle absorbs the sun's radiated emissions and depending on the external environment can become extremely hot after a vehicle has been exposed to the sunlight for an extended period of time. Typically, the vehicle passenger must ventilate the passenger compartment by lowering the vehicle windows. While this manual method of purging the super heated air works to remove the air from the interior of the vehicle, unfortunately, the vehicle occupant is also subjected to the super heated air. Consequently, depending on how long the vehicle has been exposed to sunlight the cool down time or “time to comfort” might be significant causing the vehicle occupant to be subjected to a very uncomfortable environment.
[0003] While this and other prior art systems and methods for controlling the build up of super heated air within vehicle interiors achieve their intended purpose other problems still exist. For example, ventilating super heated air through vehicle sunroofs and windows leaves the vehicle vulnerable to theft, as well as water damage in rainy conditions, and dirt in dusty conditions. Generally, prior art solutions are inflexible and only eliminate the super heated air at fixed times and for fixed time periods.
[0004] Therefore, what is needed is a new and improved system and method for controlling the build up of super heated air within an interior compartment of a vehicle. Such a new and improved system and method should ventilate the super heated air only as required to provide a comfortable environment for vehicle occupants.
SUMMARY
[0005] In accordance with an aspect of the invention a ventilation system for purging air contained within a vehicle interior is provided. The ventilation system includes a blower, a first vent, a second vent, at least one interior temperature sensor, at least one external temperature sensor, a humidity sensor, a motion sensor for windy days and dusty areas, a sunload sensor and a control module. The blower is a conventional vehicle air conditioning blower and is located within the vehicle interior for creating a pressure differential between the interior and exterior of the vehicle. The first vent expels air from the vehicle interior and the second vent draws external air into the vehicle interior. The at least one interior sensor is located within the vehicle interior for determining an interior condition of the vehicle. The at least one external sensor determines an external condition of environment external to the vehicle interior. Finally, the control module is in communication with the blower, first and second vents, interior and exterior sensors for monitoring the internal and exterior sensors and comparing the sensor outputs to predefined thresholds for actuating the blower, first and second vents to exhaust the air contained within the interior of the vehicle and draw in ambient air.
[0006] In accordance with another aspect of the invention a method for ventilating hot air contained with a vehicle interior is provided. The method includes creating a pressure differential between the interior and exterior of the vehicle using a bidirectional blower, expelling air from the vehicle interior using a first vent, drawing external air into the vehicle using a second vent, determining an interior condition of the vehicle using at least one interior sensor located within the vehicle interior, determining an external condition of the environment external to the vehicle using at least one external sensor, and finally, communicating with the blower, first and second vents, interior and exterior sensors to monitor the internal and exterior sensors and to compare the sensor outputs to predefined thresholds to actuate the blower, first and second vents to exhaust the air contained within the interior of the vehicle and draw in ambient air, using a control module.
[0007] Further objects, features and advantages of the invention will become apparent from consideration of the following description and the appended claims when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a schematic diagram of a system for controlling the build up of super heated air within a vehicle's interior, in accordance with the present invention;
[0009] [0009]FIG. 2 is a block diagram illustrating a control module for use with the system of the present invention;
[0010] [0010]FIGS. 3 a - d are flow diagrams illustrating a method for controlling build up of super heated air within a vehicle interior, in accordance with the present invention;
[0011] [0011]FIG. 4 is a flow diagram illustrating a method for carrying out a High Cabin Pressure Strategy, in accordance with the present invention; and
[0012] [0012]FIG. 5 is a flow diagram illustrating a method for carrying out a Low Cabin Pressure Strategy, in accordance with the present invention.
DETAILED DESCRIPTION
[0013] The following description of the preferred embodiment is merely exemplary in nature, and is in no way intended to limit the invention or its application or uses.
[0014] Shown in FIG. 1 is a vehicle 10 that includes a cabin air purge system (CAPS) 12 for evacuating super heated air trapped within the passenger compartment 14 of vehicle 10 . Cabin air purge system 12 , includes a passenger compartment temperature sensor 16 , a passenger compartment humidity sensor 18 , a motion sensor 20 , a bidirectional blower motor 22 , defrost vents 24 , fresh air intake vent 26 , ambient temperature sensor 28 , ambient humidity sensor 30 , and a cabin air purge control module 32 . Passenger compartment temperature sensor 16 and passenger compartment humidity sensor 18 are placed within the passenger compartment of vehicle 10 for measuring the temperature and humidity of the passenger compartment, respectively. Motion sensor 20 also located within the passenger compartment may be used in conjunction with the other sensors to detect wind direction. Blower motor 22 is capable of running in a forward direction to draw fresh air into the fresh air intake vent 26 and distributing the air into the passenger compartment through the panel/floor vents 24 . Blower motor 22 also may be operated in reverse to draw cabin air into the defroster vents 24 and expel the air out of the passenger compartment through fresh air intake vent 26 .
[0015] With continuing reference to FIG. 1, ambient temperature sensor 28 and ambient humidity sensor 30 are illustrated, in accordance with the present invention. Ambient temperature sensor 28 and ambient humidity sensor 30 are placed outside of the passenger compartment. Temperature sensor 28 measures the ambient air temperature while humidity sensor 30 measures the ambient air humidity.
[0016] Control module 32 , is shown in greater detail in FIG. 2. Control module 32 is operatively configured to receive sensor signals from the sensors described above. As will be described in greater detail below, control module 32 broadcasts control signals to actuate various vehicle components such as windows 34 , the mode doors (not shown) of the vehicles climate control system, and blower motor 22 to carry out the cabin air purge strategy of the present invention. Other vehicle components may also be actuated by control module 32 to aid in carrying out the control strategy. For example, a vehicle sunroof may also be used to purge cabin air or draw in ambient air.
[0017] Control module 32 is preferably located within the passenger compartment and has a plurality of sensor input ports 50 for receiving various sensor signals. It will be apparent to one of ordinary skill in the art that additional input ports and/or output ports may be utilized for communicating with additional sensors and vehicle components. Accordingly, a plurality of actuator ports 52 are provided on control module 32 for actuating various vehicle components 54 .
[0018] Vehicle components 54 may include blower motor 22 , mode door (not shown) and windows 34 . Of course, other motor vehicle components and systems may also be actuated by control module 32 for enhancing the operation of cabin air purge system 12 . Additionally, for each of the vehicle components 54 actuated by control module 32 , feedback input ports 56 are provided in control module 32 for receiving feedback signals from the vehicle components. For example, a blower motor feedback signal allows control module 32 to determine the direction of the blower motor, as well as, the rotational speed of the motor. Similarly, a mode door feedback signal is received by control module 32 for determining mode door status, such as open or closed. A window feedback signal is also provided, for enabling control module 32 to determine the window status (open or closed).
[0019] With continuing reference to FIG. 2, battery power 58 , ignition 60 , and ground 62 connections are illustrated, in accordance with the present invention. Battery power connection 58 provides a battery voltage signal to control module 32 to allow monitoring of the battery voltage to insure the system does not degrade the battery voltage to an unacceptable level. For example, the present invention may prevent the continued operation of the cabin air purge system to insure the vehicle's engine will start. The unacceptable battery voltage level is, of course, temperature dependent. Additionally, an adaptive learning strategy is incorporated to optimize battery performance. Ignition connection 60 provides the input that triggers control module 32 to operate. Ground connection 62 provides the required electrical ground for control module 32 , typically, ground 62 is at or near the voltage level of the negative battery terminal.
[0020] Reference is now made to FIGS. 3 a - 3 d , wherein a cabin air purge strategy (CAPS) or methodology is illustrated, in accordance with the present invention. The cabin air purge strategy is initiated, at block 100 . At block 102 , an ignition switch is checked. If the ignition switch is “OFF” then a read CAPS sensors routine is initiated, at block 97 . The CAPS sensors that are read are, for example, the sensors described above. At block 106 a cabin pressure equalization strategy is initiated. The cabin pressure equalization strategy cracks open the windows (if they are shut) when the ignition is turned “OFF” and any car door is opened. Further, the windows are then shut after all the car doors are closed. Thus, door closing efforts are reduce and the vehicle has a higher quality feel. However, If the ignition switch is not “OFF”, then a last ignition state flag is set to “ON”, as represented by block 105 . The last ignition state is determined, at block 103 . If the last ignition state is “ON” then the last ignition state flag is set to “OFF”, as represented by block 107 . This path is only executed once upon the transition from ignition “ON” to ignition “OFF”.
[0021] At block 101 , a CAPS user switch is checked. If the CAPS user switch is “on” then the system checks whether the windows are closed, at block 104 . However, if the CAPS user switch is “OFF” then the system determines the whether a CAPS enable flag has been set to “TRUE”, at block 113 .
[0022] A block 104 , the system determines whether the windows are closed. If the windows are determined to be closed then the “CAPS enabled flag” is set to “TRUE”, as represented by 109 and an “ignition off time” variable is set to “getTime( )”, at block 111 . This function gets the current time and stores it in the variable “ignition off time”. Thus, as illustrated above, CAPS is only activated if the ignition transitions from “on” to “off” and the CAPS user switch is “on” and the windows are closed at the time of the ignition transition. A CAPS enabled flag is checked, at block 113 . If the CAPS enabled flag is “TRUE” then a CAPS entry ignition off time is set equal to a calculated adaptive CAPS entry ignition off time, as represented by block 99 . However, if CAPS enabled flag is not set to “True” then a cabin pressure equalization strategy complete flag is set equal to “True”, as represented by block 159 .
[0023] The cabin air purge strategy also determines how long the ignition has been “off”, as represented by block 108 . This “ignition off-time” determination is calibratable and is selected based on the environmental conditions the vehicle will be primarily exposed to. Further this “ignition off time” is determined via an adaptive learning algorithm. For example, if the vehicle is primarily operated in an extremely hot environment, the ignition “off time” may be adjusted to a low value in order to activate the cabin air purge strategy more often. Thus, if the getTime( ) minus the ignition “off time” is not greater than the preset ignition “off time” (or CAPS_entry_IGW_off_time) the cabin air purge strategy is restarts. However, if the ignition “off time” is greater than the preset ignition “off time”, then the cabin air purge strategy continues at block 115 where a daylight hysteresis flag is checked. Thus, the present invention does not enable CAPS unless the vehicle has been off for a minimum amount of time. For example, preferably CAPS is not activated when a user goes to a gas station to re-fuel the vehicle.
[0024] If the daylight hysteresis flag is “on” as it would be during a first cycling of the cabin air purge strategy then a CAPS_Validdaylight variable is set to a high value, as represented by block 117 . However, if the daylight hysteresis flag is “off”, then the CAPS_Validdaylight variable is set to a low value, as represented by block 119 . At block 121 , the daylight, as measured at block 97 is compared to the CAPS_Validdaylight variable. If the current daylight is not greater than the CAPS_Validdaylight variable, then the daylight hysteresis flag is set to “off”, as represented by block 125 and the cabin air purge strategy is terminated. However, if the current daylight is greater than the CAPS_Validdaylight variable, then the daylight hysteresis flag is set to “on”, as represented by block 123 . Thus, CAPS is aborted if it is dark outside (i.e. night time), since it is unlikely the temperature of the vehicle's interior will be elevated due to radiated heat from the sun. This strategy also lessens wear and tear on the battery and other mechanical actuators.
[0025] Continuing at block 127 , the strategy checks the in car hysteresis flag. If the in car hysteresis flag is “on” as it would be during a first cycling of the cabin air purge strategy then a CAPS_ValidinCarTemp variable is set to a high value, as represented by block 129 . However, if the in car hysteresis flag is “off”, then a CAPS_ValidinCarTemp variable is set to a low value, as represented by block 131 . At block 133 , the in car temperature, as measured during the block 97 is compared to the CAPS_ValidinCarTemp variable. If the current in car temperature is not greater than the CAPS_ValidinCarTemp variable the in car hysteresis flag is set to “on”, as represented by block 137 and the cabin air purge strategy is restarted. However, if the ambient temperature is greater than the ambient temperature variable, then the ambient hysteresis flag is set to “off”, as represented by block 120 . Thus, if an in-car temperature is low then CAPS is aborted.
[0026] At block 110 it is determined whether the algorithm will be using a “low” or “high” temperature constant when determining whether or not to execute the cabin air purge strategy. Upon entering this algorithm the first time the hysteresis flag is set to “on” which means that the ambient temperature must be higher than the “hi” temperature constant, block 112 , to continue with the cabin air purge strategy, block 116 . This means that the strategy will never be executed unless the ambient temperature has exceeded this “hi” temperature constant, block 118 . Assuming that the ambient temperature has exceeded the “hi” temperature constant, block 116 , the ambient hysteresis flag is set to “off”, block 120 . This means that the next time the algorithm executes, block 110 , the temperature constant which is compared against the ambient temperature, is the “low” temperature constant, block 114 . Therefore, even when the ambient temperature falls below the ambient temperature “hi” constant the cabin air purge strategy will continue to function based on the ambient temperature sensor input until it falls below the “low” constant. In which case, the ambient hysteresis flag is set to “on”, block 118 and the strategy is disabled till the ambient temperature sensor rises above the “hi” temperature constant. This insures that the system is not cycled rapidly because of an ambient temperature sensor that is fluctuating by several degrees. This protects the system from wear and tear, and provides for more efficient operation. The method or control strategy of the present invention uses hysteresis and hysteresis flags throughout for this purpose.
[0027] Continuing at block 127 , the strategy checks an InCar hysteresis flag. If the InCar hysteresis flag is “on” as it would be during a first cycling of the cabin air purge strategy then an CAPS_InCar variable is set to a high value, as represented by block 129 . However, if the InCar hysteresis flag is “off”, then the CAPS_InCar variable is set to a low value, as represented by block 131 . At block 133 , the InCar temperature, as measured during the cabin pressure equalization strategy of block 106 , is compared to the CAPS_ValidInCar temperature. If the current InCar temperature is not greater than the CAPS_ValidInCar temperature the InCar hysteresis flag is set to “on”, as represented by block 137 and the cabin pressure equalization strategy complete flag is set equal to “True”, as represented by block 159 . However, if the InCar temperature is greater than the CAPS_ValidInCar temperature variable, then the InCar hysteresis flag is set to “off”, as represented by block 135 .
[0028] At block 139 , an ambient temperature is subtracted from the in car temperature and the result is compared to an Incar_ambient_delta variable. If the result is greater than the Incar_ambient_delta variable then the cabin pressure equalization strategy complete flag is set equal to “True”, as represented by block 159 . Thus, if the absolute value of the difference between the in car temperature and the ambient air temperature is greater than the calibratable value “in car_ambient delta” CAPS is aborted. This may result from a malfunctioning sensor, or the vehicle recently running with the heater on in cold weather, or the AC running in hot weather. However, if the result is less than the Incar_ambient_delta variable then the in car temperature is compared to the ambient temperature at block 141 . If the in car temperature is less than the ambient temperature then the cabin pressure equalization strategy complete flag is set equal to “True”, as represented by block 159 . However, if the in car temperature is greater than the ambient temperature then a calculate adaptive CAPS battery voltage parameter routine is executed, at block 143 . This routine calculates an “AdaptiveCAPS_BatteryVoltage low” and an “AdaptiveCAPS_BatteryVoltage High” parameters. Thus, if the vehicle's interior is cooler than the outside air temperature, CAPS is aborted. This may occur, for example, if it is a sunny day and the vehicle is parked in the shade and the AC has been running for a significant period of time.
[0029] At block 122 a voltage hysteresis flag is checked to determine whether the flag is “on”. If the flag is “on”, then a voltage variable is set to a high voltage, as represented by block 124 . However, if the voltage hysteresis flag is “off”, then the voltage variable is set to a low voltage level, as represented by block 126 . The system voltage as measured during the cabin pressure equalization strategy of block 106 , is compared to the voltage variable, as represented by block 128 . If the system voltage is not greater than the voltage variable, the voltage hysteresis flag is set to “on”, as represented by block 130 and the cabin air purge strategy is terminated. However, if the system voltage is greater than the voltage variable then the voltage hysteresis flag is set to “off”, as represented by block 132 . Thus, the system verifies that the battery has enough voltage to operate CAPS and allow the vehicle to be started.
[0030] A humidity hysteresis flag is checked, at block 134 . If the humidity hysteresis flag is “on”, then a humidity variable is set to a low humidity level, as represented by block 136 . However, if the humidity hysteresis flag is set to “off”, then the humidity variable is set to a high humidity level, as represented by block 138 . At block 140 , the humidity read during the cabin pressure equalization strategy of block 106 is compared to the humidity variable. If the current humidity is greater than the humidity variable, then the humidity hysteresis flag is set to “on”, as represented by block 142 . However, if the humidity is less than the humidity variable, the humidity hysteresis flag is set to “off”, as represented by block 144 . Thus, if it is very humid the humidity hysteresis flag will be set to “on”.
[0031] At block 146 , a sunload load hysteresis flag is checked to determine whether it is “on”. If the sunload hysteresis flag is “on”, then a sunload variable is set to a high sunload value, as represented by block 148 . However, if the sunload hysteresis flag is set to “off”, then the sunload variable is set to a low sunload value, as represented by block 150 . At block 152 , the actual measured sunload measured during the cabin pressure equalization strategy routine of block 106 is compared to the value of the sunload variable. If the sunload is not greater than the sunload variable, then the sunload hysteresis flag is set to “on”, as represented by block 154 . However, if the sunload is greater than the sunload variable, the sunload hysteresis flag is set to “off”, as represented by block 156 . Thus, if it is very cloudy the sunload hysteresis flag will be set to “on”.
[0032] At block 158 , the sunload hysteresis flag and the humidity hysteresis flag are checked. If the sunload hysteresis flag and the humidity hysteresis flag are set to “on” then the cabin pressure equalization strategy complete flag is set equal to “True”, as represented by block 159 . At block 172 , a CAPS_Close Window( ) routine is executed to close the vehicle's windows. Thus, if it is cloudy and humid (high chance of rain) then CAPS is aborted. Moreover, this strategy uses feedback current from the window motors to determine if anything is blocking the window's path. If the window's path is being blocked the window opens and tries to closes several times. If the window's path is still blocked the window will remain open.
[0033] At block 173 , a CAPS_StopActuators( ) routine is initiated. This routine stops the operation of the climate control motor and mode doors. Various system variable are then reset at block 170 before the strategy returns to the beginning, as represented by block 168 .
[0034] However, if either the sunload hysteresis flag or the humidity hysteresis flag are set to “off”, then a HCPS_LCPS_StartDelay time is subtracted from a gettime( ) variable and the result is compared to a HCPS_LCPS_Delay_Time constant, at block 157 . If the result is greater than or equal to the HCPS_LCPS_Delay_Time constant a high pressure cabin strategy flag is checked, at block 160 . This allows for a time delay between the High Cabin Pressure Strategy (HCPS) and Low Cabin Pressure Strategy (LCPS), so that the system is not running the blower continuously till the battery is drained.
[0035] If the high pressure cabin strategy flag is “off”, then a low pressure cabin strategy flag is checked, at block 162 . However, if the high pressure cabin strategy flag is set to “on”, then the high pressure cabin strategy routine is initiated, as represented by block 163 , and thereafter the strategy returns to the beginning of the process, as represented by block 168 . Upon initial entry into this algorithm the high pressure cabin strategy flag is “on” which will initiate the execution of the high pressure cabin strategy. The high pressure cabin strategy incorporates a series of timers and logic that set the high pressure cabin strategy flag to “off” and turns “on” the low pressure cabin strategy flag.
[0036] Accordingly, at block 166 a low pressure cabin strategy routine is initiated if the low cabin pressure strategy flag is on, as determined at block 162 . Thereafter, the strategy returns to the beginning of the process, as represented by block 168 . However, if the low cabin pressure strategy flag is off then the strategy returns to the beginning of the process, as represented by block 168 . Likewise, the low pressure cabin strategy also incorporates a series of timers and logic that turns “off” the low pressure cabin strategy flag and turns “on” the high pressure cabin strategy flag. This enables a mutually exclusive cycling of the low pressure cabin strategy and the high pressure cabin strategy.
[0037] The high cabin pressure strategy is illustrated in flow chart form in FIG. 4. In operation, the high cabin pressure strategy is initiated at block 200 . At block 202 , the climate control mode doors are set to panel/floor. The climate control blower direction is set to normal and the blower is set to maximum speed, as represented by 204 . At block 206 , a startHCPS_Time is subtracted from the gettime( ) and the result is compared to HCPS_Window_Open_Time variable. Here the system determines whether the windows have been open long enough. HCPS_Window_Open_Time must be greater than HCPS_Window_Closed_Time for the strategy to function properly. If the result is not greater than HCPS_Window_Open_Time the result is compared to HCPS_Window_Closed_Time variable to determine if the windows have been closed long enough, as represented by block 208 . However, if the result is greater than HCPS_Window_Open_Time variable then a CAPS_CloseWindow routine is activated, at block 210 . At block 212 , the high cabin pressure strategy flag is set to “off”. At block 214 , the low cabin pressure strategy flag is set to “on”. At block 216 , a start_LCPS_Time variable is set equal to the getTime( ) variable and then terminates at return block 218 . Thus, the HCPS is completed, the windows are closed and setup for LCPS.
[0038] However, if at block 208 , the result of startHCPS_Time subtracted from gettime( ) is greater than HCPS_Window_Closed_Time variable then a MotionSensorSelectCAPS_ActiveWindows( ) routine and a CAPS_OpenWindow( ) routines are activated, at blocks 219 and 220 . The MotionSensorSelectCAPS_ActiveWindows( ) routine determines wind direction and which windows should be opened. Thereafter, the strategy returns to the starting point, as represented by block 218 . However, if at block 208 , the result of startHCPS_Time subtracted from gettime( ) is less than HCPS_Window_Closed_Time variable then the strategy terminates at return block 218 .
[0039] Thus, in operation the high cabin pressure strategy forces outside air into the vehicle via panel and floor vents, for example, by running the blower in the normal forward direction while the windows are closed. This will cause the hotter air to rise within the vehicle interior and create a positive pressure within the vehicle interior, so that when the windows are opened the hot air is forced out.
[0040] A low cabin pressure strategy is illustrated in flow chart form in FIG. 5. In operation, the low cabin pressure strategy is initiated, at block 300 . At block 302 , the climate control mode doors are set to panel/defrost. The climate control blower direction is set to reverse and the blower is set to maximum speed, as represented by 304 . At block 306 , the start_LCPS_Time is subtracted from the gettime( ) and the result is compared to an LCPS_Window_Open_Time variable. Here the system determines whether the windows have been open long enough. LCPS_Window_Open_Time must be greater than LCPS_Window_Closed_Time for the strategy to function properly. If the result is not greater than LCPS_Window_Open_Time variable the result is compared to LCPS_Window_Closed_Time variable to determine if the windows have been closed long enough, as represented by block 308 . However, if the result is greater than LCPS_Window_Open_Time variable then a CAPS_CloseWindow routine is activated, at block 310 . At block 312 , the high cabin pressure strategy flag is set to “on”. At block 314 , the low cabin pressure strategy flag is set to “off”. At block 316 , a start_HCPS_Time variable is set equal to the getTime( ) variable and then terminates at return block 318 . Thus, the LCPS is completed, the windows are closed and setup for HCPS.
[0041] If at block 308 , the result of start_LCPS_Time subtracted from gettime( ) is greater than LCPS_Window_Closed_Time variable then a MotionSensorSelectCAPS_Active-Windows( ) and a CAPS_OpenWindow( ) routines are activated, at blocks 319 and 320 . The MotionSensorSelectCAPS_ActiveWindows( ) routine determines wind direction and which windows should be opened. Thereafter, the strategy returns to the starting point, as represented by block 318 . However, if at block 308 , the result of start_LCPS_Time subtracted from gettime( ) is less than LCPS_Window_Closed_Time variable then the strategy terminates at return block 318 .
[0042] Thus, in operation the low cabin pressure strategy expels hot air out of the vehicle via the panel and defrost vents, by running the blower in the reverse direction while the vehicle's windows are closed. The panel and defrost vents are used since the hotter air will rise within the vehicle interior. This creates a negative pressure within the interior of the vehicle, so that when the windows are opened fresh cool air rushes into the vehicle through the windows replacing the hot interior air.
[0043] Upon system reset or initialization key CAPS variables are initialized. For example, InCarHysteresisFlag is set to “on”, VoltageHysteresisFlag is set to “on”, HumidityHysteresisFlag is set to “on”, SunloadHysteresisFlag is set to “on”, and the DaylightHysteresisFlag is set to “on”. Additionally, the CAPS_enabledFlag is set to “false”, the LowCabinPressureStrategyFlag is set equal to the Low_CPS_Flag, the HighCabinPressureStrategyFlag is set equal to the High_CPS_Flag and the CabinPressureEqualizationStrategyCompleteFlag is set equal to “False”. These calibration constants are stored in non-volatile RAM, such as EEPROM, and if both are set to off, the CAPS strategy will be disabled. This allows the manufacturing plant flexibility in deciding which vehicles have the CAPS strategy activated.
[0044] The foregoing discussion discloses and describes a preferred embodiment of the invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that changes and modifications can be made to the invention without departing from the true spirit and fair scope of the invention as defined in the following claims.
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A ventilation system for purging air contained with a vehicle interior is disclosed. The ventilation system includes a blower, a first vent, a second vent, at least one interior temperature sensor, at least one external temperature sensor, a motion sensor for windy days and dusty areas, a humidity sensor, a sunload sensor and a control module. The blower is a conventional vehicle air conditioning blower and is located within the vehicle interior for creating a pressure differential between the interior and exterior of the vehicle. The first vent expels air from the vehicle interior and the second vent draws external air into the vehicle interior. The at least one interior sensor is located within the vehicle interior for determining an interior condition of the vehicle. The at least one external sensor determines an external condition of environment external to the vehicle interior. Finally, the control module is in communication with the blower, first and second vents, interior and exterior sensors for monitoring the internal and exterior sensors and comparing the sensor outputs to predefined thresholds for actuating the blower, first and second vents to exhaust the air contained within the interior of the vehicle and draw in ambient air.
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This application claims the benefit of U.S. Provisional Application No. 60/003,351 filed Sep. 7, 1995.
BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to three and four component blends of ethylene vinyl alcohol copolymers, ionomer, and nylon (semicrystalline nylon in the three-component blend and semicrystalline and amorphous nylon in the four-component blend). These blends have a unique balance of properties and are useful in packaging films, laminates, co-extrusions and containers prepared therefrom. Also, the barrier resins of the present invention can be used as coatings on substrates such as paperboard and can be used in structures that are not multi-layer.
2. Background Discussion and Related Art
Ethylene/vinyl alcohol copolymers (EVOH), particularly those with high levels of vinyl alcohol, exhibit excellent oxygen barrier properties at low humidity. Typically, to provide good barrier properties at high humidities, EVOH is laminated on both sides with polyolefins (see U.S. Pat. No. 3,882,259 which is incorporated herein by reference). U.S. Pat. Nos. 4,952,628; 4,990,562; 5,003,002; 5,064,716; 5,110,855; 5,126,401; 5,126,402; 5,194,306; 5,208,082; and 5,286,575 (all of which are incorporated herein by reference) teach various blends of EVOH and amorphous nylon, and, in some cases, semicrystalline nylon with the amorphous nylon that have barrier properties less dependent on humidity. U.S. Pat. No. 4,082,854 which is incorporated herein by reference suggests a wide variety of polymers that can be blended with EVOH to improve gas permeation characteristics particularly for packaging applications.
In European Patent No. 0 470 486, entitled, "Toughened ethylene (vinyl alcohol) copolymer resins," which is incorporated herein by reference, the EVOH is blended with terpolymers of alpha-olefin, acrylate and either partly neutralized carboxylic acid groups or carbon monoxide. The combination is taught to have a combination of excellent oxygen barrier, toughness and thermoforming characteristics in the form of sheet or film.
It is also known that excellent properties such as gas-barrier, impact resistance, stretchability, drawability and transparency can result from blends of EVOH, ionomer and semicrystalline nylon (see Japanese Patent Application HEI6-310239, filed Dec. 14, 1994, to Kenji Miharu, inventor, which is incorporated herein by reference).
SUMMARY OF INVENTION
This invention provides resin compositions with good gas-barrier properties, in particular properties that provide barrier to oxygen and carbon dioxide. The compositions are three- and four-component blends of ethylene vinyl alcohol (EVOH), ionomer, and polyamide (semicrystalline polyamide, plus, in the four-component blend, amorphous polyamide). The three-component blend employs EVOH, an ionomer with low free acid and high melt flow, low semicrystalline polyamide content, and optionally a metal salt of stearic acid, such as calcium stearate, which is believed to act as an acid scavenger.
Films or laminated structures which incorporate these blends are suitable for use in packaging applications, particularly as a gas barrier layer in multilayer co-extruded, blown, or cast films, cast sheet, laminated structures or coextrusion-blow-molded containers.
DETAILED DESCRIPTION OF INVENTION
One composition of this invention comprises a melt-blend of EVOH, amorphous nylon, semicrystalline nylon, and an ionomer. The components (percentages are weight percentages based on the total weight of the four components) are present in the following amounts:
1. About 40 to about 92%, or about 60 to about 80%, or about 50 to about 75 EVOH resin;
2. About 1 to about 30%, or about 5 to about 25%, or about 10 to about 20%, amorphous polyamide resin;
3. About 2 to about 30%, or about 5 to about 20%, or about 10 to about 15%, semicrystalline polyamide; and
4. About 5 to about 30%, about 10 to about 25%, about 5 to about 15%, ionomer.
Optionally, about 0.1 to 1.0% by weight of the total melt-blend of a hindered phenol antioxidant such as IRGANOX available from Ciba may be included. In another embodiment, the melt blend may optionally contain from 0.05 to 5% by weight of a hindered phenol antioxidant based on total melt-blend. Fillers such as those described in U.S. Pat. No. 4,952,628, particularly Muscovite mica and Phlogopite mica (up to about 20 weight %) with an aspect ratio of 10 to 150 and particle size of smaller than 200 mesh (74 micrometers) may be included. Also, metal salts of long chain (C 8 to C 10 or greater) carboxylic acids, particularly metal salts of stearic acid, more particularly calcium stearate (0.1 to 1.0% by weight, alternatively 0.05 to 5%) can be added.
In another embodiment, the amorphous nylon is excluded from the blend. That is, the blend of this embodiment consists essentially of EVOH, an ionomer with a low free-acid level and relatively high melt flow, a low weight percent semicrystalline nylon (preferably less than 9 weight percent of the polymers in the blend), and optionally a metal salt of stearic acid, preferably calcium stearate, believed to operate as an acid scavenger. This embodiment has been found to provide surprising improvements in thermal stability and adhesion over the three-component blends of Japanese Patent Application HEI6-310239.
The components (percentages are weight percentages based on the total weight of the three components) in this three-component blend are present in the following amounts:
1. About 60 to about 90%, or about 65 to about 85%, or about 70 to about 80% EVOH resin; and
2. About 10 to about 40%, or about 15 to about 35%, or about 20 to about 30%, of a blend of semicrystalline polyamide and ionomer, the ionomer being about 50 to about 90 weight % of the ionomer/polyamide blend, preferably about 75 to about 90 weight % of the blend.
Other components such as the hindered phenol antioxidants, fillers, and metal salts of long-chain carboxylic acids such as discussed above and in levels noted may be used. It is particularly preferred, however, to incorporate about 0.01 to about 3.0, preferably about 0.0 to about 1 weight percent, based on the weight of the polymer components, of a metal salt of a long-chain carboxylic acid, particularly a metal salt of stearic acid, most preferably calcium stearate.
Components of the present invention are discussed below along with the process for making the melt-blends of the present invention.
EVOH
The EVOH resins useful in this invention include resins having a copolymerized ethylene content of about 20 to about 60 mole %, especially about 25 to about 50 mole %. These polymers will have a degree of saponification of at least about 90%, especially at least about 95%. The EVOH copolymer may include as an optional comonomer other olefins such as propylene, butene-1, pentene-1, or 4-methylpentene-1 in such an amount as to not change the inherent properties of the copolymer, that is, usually in an amount of up to about 5 mole % based on total copolymer. The melting points of these EVOH polymers are generally between 160° and 190° C.
The EVOH polymers are normally prepared by a process well known in the art, that is, by copolymerization of ethylene with vinyl acetate, followed by hydrolysis of the vinyl acetate component to give the vinyl alcohol group.
Amorphous Nylon
Amorphous polyamides are well known to those skilled in the art (particularly as selected from among those described in U.S. Pat. Nos. 4,952,628 and 4,990,562). "Amorphous polyamide," as used herein, refers to those polyamides which are lacking in crystallinity as shown by the lack of an endotherm crystalline melting peak in a Differential Scanning Calorimeter ("DSC") measurement (ASTM D-3417), 10° C./minute heating rate.
Examples of amorphous polyamides are those prepared from the following diamines: hexamethylenediamine, 2-methylpentamethylenediamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)isopropylidine, 1,4- and 1,3 diaminocyclohexane, meta-xylylenediamine, 1,5-diaminopentane, 1,4-diaminobutane, 1,3-diaminopropane, 2-ethyldiaminobutane, 1,4-diaminomethylcyclohexane, p-xylyenediamine, m- and p-phenylenediamine, and alkyl-substituted m- and p-phenylenediamine. These examples are prepared from the following dicarboxylic acids: iso- and tere-phthalic acid, alkyl-substituted iso- and tere-phthalic acid, adipic acid, sebacic acid, butane dicarboxylic acid, and the like.
Specific examples of the amorphous polyamides that can be used include hexamethylenediamine isophthalamide/terephthalamide having iso/terephthalic moiety ratios of 100/0 to 60/40, mixtures of 2,2,4- and 2,4,4-trimethylhexamethylenediamine terephthalamide, copolymers of hexamethylene diamine and 2-methylpentamethylenediamine with iso- or terephthalic acids, or mixtures of these acids. Polyamides based on hexamethylenediamine iso/terephthalamide containing high levels of terephthalic acid moiety may also be useful provided a second diamine such as 2-methyldiaminopentane is incorporated to produce a processible amorphous polymer.
Amorphous polyamides may contain, as comonomers, minor amounts of lactam species such as caprolactam or lauryl lactam, even though polymers based on these monomers alone are not amorphous as long as they do not impart crystallinity to the polyamide. In addition, up to about 10 wt. % of a liquid or solid plasticizer such as glycerol, sorbitol, mannitol, or aromatic sulfonamide compounds (such as "Santicizer 8" from Monsanto) may be included with the amorphous polyamide.
The amorphous polyamide may also be selected from those containing less than about 100 milli-equivalents of terminal carboxyl groups per kilogram of polyamide, as disclosed in U.S. Pat. No. 5,126,402. Preferably, those amorphous polyamides having less than 85 or less than 55 milliequivalents per kilogram may be used.
Semicrystalline Nylon
Semicrystalline polyamides used in the present invention are well known to those skilled in the art. Semicrystalline polyamides suitable for this invention are generally prepared from lactams or amino acids, such as nylon-6 or nylon-11, or from condensation of diamines such as hexamethylene diamine with dibasic acids such as succinic, adipic, or sebacic acid. Copolymers and terpolymers of these polyamides are also included.
Preferred semicrystalline polyamides are polyepsiloncaprolactam (nylon-6), polyhexamethylene adipamide (nylon-66), most preferably nylon-6. Other semicrystalline polyamides useful in the present invention include nylon-11, nylon-12, nylon-12,12 and copolymers and terpolymers such as nylon-6/66, nylon-6/10, nylon-6/12, nylon-66/12, nylon-6/66/610 and nylon-6/6T. In the three-component blend, nylon 6 is the most preferred semicrystalline polyamide.
Ionomer
The ionomers of the present invention are derived from direct copolymers of ethylene and α,β-ethylenically-unsaturated C 3 -C 8 carboxylic acid ("ethylene-acid copolymers") by neutralization with metal ions. By "direct copolymer", it is meant that the copolymer is made by polymerization of monomers together at the same time, as distinct from a "graft copolymer" where a monomer is attached or polymerized onto an existing polymer chain. Methods of preparing such ionomers are well known and are described in U.S. Pat. No. 3,264,272 which is herein incorporated by reference. Preparation of the direct ethylene-acid copolymers on which the ionomers are based is described in U.S. Pat. No. 4,351,931 which is also incorporated by reference herein.
The ethylene-acid copolymers used to make the ionomeric copolymer of this invention can be E/X(Y copolymers where E is ethylene; X is a softening comonomer and Y is the α,β-ethylenically-unsaturated C 3 -C 8 carboxylic acid, particularly acrylic or methacrylic acid. Preferably, however, the ethylene-acid copolymer is a dipolymer (no softening comonomer). The preferred acid moieties are methacrylic acid and acrylic acid.
By "softening", it is meant that the polymer is made less crystalline. Suitable "softening" comonomers (X) are monomers selected from alkyl acrylate, and alkyl methacrylate, wherein the alkyl groups have from 1-12 carbon atoms which, when present, may be up to 30 (preferably up to 25, most preferably up to 15) wt. % of the ethylene-acid copolymer.
A wide range of percent acid moiety in the ethylene-acid copolymer may be used. The acid moiety may be present in a range of about 1 to 30 weight percent of the acid copolymer, preferably in a range of about 5 to 25, alternatively about 10 to about 20. The ethylene-acid copolymers with high levels of acid are difficult to prepare in continuous polymerizers because of monomer-polymer phase separation. This difficulty can be avoided however by use of "cosolvent technology" as described in U.S. Pat. No. 5,028,674 which is also incorporated herein by reference or by employing somewhat higher pressures than those at which copolymers with lower acid can be prepared.
The ethylene-acid copolymers are partially neutralized (15 to 75 percent) with metal cations, particularly monovalent and/or bivalent metal cations. Preferably about 25 to about 60 of the acid is neutralized. Preferred metal cations include lithium, sodium, and zinc, or a combination of such cations. Zinc is most preferred.
In the case of the three-component blend, the ionomer has a low free-acid level and preferably has a relatively high melt flow. By "low free-acid level," it is meant that the residual acid after neutralization is less than about 10 weight %, about 7%, preferably less than about 5%. The desired free acid level may be achieved by controlling the acid in the starting ethylene-acid copolymer, preferably to less than about 15%, more preferably 12% or less, and by controlling the percent neutralization to get the desired free acid level. High neutralization, that is neutralization above about 60, should be avoided since it may reduce thermoformability. By "relatively high melt flow," it is meant that the melt flow of the partially-neutralized ethylene/α,β-ethylenically-unsaturated C 3 -C 8 carboxylic acid copolymer has a melt flow greater than that taught in Japanese Patent Application HEI6-3 10239, preferably greater than 3, or greater than 5, or more preferably about 10 grams/10 minutes or greater when measured per ASTM D-1238, condition E.
Preferred ethylene-acid dipolymers are ethylene/acrylic acid and ethylene/methacrylic acid. Specific other copolymers include ethylene/n-butyl acrylate/acrylic acid, ethylene/n-butyl acrylate/methacrylic acid, ethylene/iso-butyl acrylate/methacrylic acid, ethylene/iso-butyl acrylate/acrylic acid, ethylene/n-butyl methacrylate/methacrylic acid, ethylene/methyl methacrylate/acrylic acid, ethylene/methyl acrylate/acrylic acid, ethylene/methyl acrylate/methacrylic acid, ethylene/methyl methacrylate/methacrylic acid, and ethylene/n-butyl methacrylate/acrylic acid.
Process
The composition of this invention is preferably made by melt compounding a mixture of the ionomer and the polyamide (amorphous polyamide and semicrystalline polyamide in the four component blend and semicrystalline polyamide alone in the three component blend), and then melt-blending the ionomer/polyamide blend with EVOH. All three or four components, however, could be directly melt-blended together. The order of addition of the polyamide and ionomer is not important. Preferably, however, the polyamide and ionomer are melt blended and then the EVOH is added.
In a preferred embodiment, the polyamide (semicrystalline and, in the four component case, amorphous polyamide) and ionomer are melt blended using conventional equipment such as a Banbury mixer, a single-screw extruder, or a twin-screw extruder at a temperature sufficiently high to melt the ionomer and semicrystalline polyamide components provided that the temperature is also high enough in the four component case for the amorphous polyamide to be softened enough to be processible. Preferably the temperature should be close to the melting point of the highest melting ionomer or semicrystalline polyamide component, so long as in the four component case the amorphous nylon is soft enough at that temperature. The mixture should be processed at a temperature that will enable one to get a homogeneous melt blend at moderate shear. Temperatures of from about 190° to 260° C. or 200° to 230° C. or perhaps even lower temperatures, say 160° to 210° C., can be used.
While the resulting melt-blend can be directly melt blended with EVOH, the melt is preferably extruded into a strand, water cooled and cut into pellets. It is also possible to melt cut the blended material into pellets using known techniques. Preferably, pellets are then cooled. Cooled pellets can then be mixed by tumble-blending with EVOH resin to make a salt and pepper blend, which in turn can be melted and used to form an extruded, cast, or blown film that can be a barrier layer in a multilayer film (up to about 10 mils in total thickness); a cast sheet (from about 10 mils up); a blow-molded container or the like. The barrier layer, typically from 0.1 to 2-5 mils (2.5 to 50-130 micrometers) thick, can be included in a multilayer structure using known techniques and equipment. Preferably the multilayer structure is co-extruded.
EXAMPLES
The objective of these examples is to demonstrate how certain variables interact to affect key properties such as gel formation, processing temperature, haze, oxygen permeation (at high and low relative humidity), thermal stability, toughness, and thermoformability. From the analysis of the data obtained, compositional blends having an outstanding balance of properties are identified. In particular, blends having an outstanding balance of properties not requiring use of 20% acid copolymer resins are identified.
EVOH/SELAR® PA/SURLYN®/Nylon Blends Test Protocol
Employing an "experimental design" protocol known as ECHIP®, a copyrighted product of Echip Inc., a 36-run experimental design (Table 1) consisting of 26 unique trials, 5 replicates and 5 checkpoints was used to evaluate the effects of and interactions between each of the following eight variables:
EVOH Concentration (60-80 wt. %).
SELAR®PA Concentration (0-30 wt. %).
SURLYN® Ionomer Concentration (5-25 wt. %).
Nylon Concentration (5-25 wt. %).
Nylon Type (6 vs. 6,66).
Acid Concentration of SURLYN® Ionomer (10-20 wt %).
Percent Neutralization of SURLYN® Ionomer (25-70%.).
Termonomer in ionomer (yes, no).
The experimental design is known as an "interaction model." Table 3. shows the 23 pairwise interactions evaluated. Specifically identified pairwise interactions demonstrate surprising performance benefits of specific blends.
For the purpose of the examples, a number of factors are kept constant and not varied. Ionomers used in making the barrier resin films were limited to Zn ionomers and the EVOH used was limited to the most widely used grade, one containing 32 mol % ethylene.
The ionomer resins used in making the barrier resin films evaluated are the ones identified in Table 2. Ionomer resins that are not commercially available are identified as Lab Grades and were prepared using well-known technology for producing ionomers.
All formulations containing SELAR®PA, SURLYN® and Nylon (either 6, or 6,6) were melt compounded and pelletized using a twin-screw extruder. All blends were made with 0.5 wt. % IRGANOX 1010 antioxidant.
EVOH pellets were tumble-blended and melt-compounded with the other materials that were melt compounded earlier, the concentrations being as set forth in Table 1, then co-extruded into three-layer films were prepared using the Brampton blown-film line. Three-layer films consisting of a 1.5 mil layer of low density polyethylene (LDPE), a 1.0 mil layer of the Barrier Blend of the composition of this invention, and another 1.5 mil layer of LDPE, without adhesive tie layers, were made. The LDPE layers were then removed to produce the barrier layer samples for testing by themselves in each of the following tests except the one for Thermoformablity (results are reported in Table 4):
OPV (cubic centimeters oxygen passing through a 100 square inch, 1 mil thick sample per day at 1 atmosphere, cc-mil/100 in 2 -day-atm.) was measured at 23° C. and 80% RH (OPV wet) and at 23° C. and 35% RH (OPV dry) using an OXTRAN Model 1000H 10-head oxygen analyzer, manufactured by Modern Controls, Inc., Minneapolis, Minn., operated in mode 4, following the method of ASTM D 3985. During the test period, probes were recalibrated daily using a PROCAL Model 1 R. H. Sensor manufactured by Modern Controls, Inc. (To obtain the cubic centimeters through a 1 square meter, 25 micrometer sample per day per 1 atmosphere, cc-25 μm/m 2 -day-atm., the cc-mil/100 in 2 -day-atm. values in the table should be multiplied by 15.5.)
Pinhole Flex Life (cycles to failure) was measured by forming a film sample into an airtight tube, applying air pressure to the inside to the tube, and then alternately flexing and relaxing axially (by a twisting and compressing and then relaxing) until failure occurs (Pin Flex). A machine similar to a Gelbo Flex tester is used.
Total Haze and Internal Haze (Intern Haze) were measured per ASTM D 1003. Total Haze measures the scattering of light from the top and bottom surfaces as well as through the film, while Internal Haze measures only the portion of light scattered in passing through the film. Internal Haze reduction is considered key and is therefore the value reported in the table. Units are percent haze.
Thermoformability (T-form) was measured using a single-station thermoformer. Three-layer film samples were solid-phase pressure formed into a specially-designed 9-cavity mold at a temperature sufficient to soften the polymer, about 150° C.). Each cavity is 1 inch (2.54 cm) in diameter. Each cavity has a different depth, varying by 0.2 inches (0.5 cm) from 0.2 to 1.8 inches (0.5 to 4.6 cm). Each cavity contained 6 vents. For each film sample, the highest depth-of-draw and the thermoform quality were noted. The highest depth of draw was determined as the deepest cavity filled without tearing the three-layer laminate. The thermoform quality (1-10, with 10 being best quality) was subjectively determined based on appearance (clarity, uniformity, EVOH breaks and layer separation causing "orange peel" in the film and striations, etc.) of the film that filled the deepest cavity without tear. The results recorded in the table were obtained by multiplying the deepest draw ratio (depth-of-draw/diameter of cavity) by the thermoform quality rating.
Spencer Impact (joules/millimeter) measured per ASTM D-3420.
Elmendorf Tear (grams/mil) measured in machine direction (MD) and the transverse direction (TD) per ASTM D-1922.
Thermal Stability was evaluated using the following factors:
1. Haake (slope)=Slope of curve (meter-kilograms/minute) measured using a Haake Model 90 Viscometer operated at 250° C., 60 revolutions per minute. Slope equals (Maximum Torque minus Minimum Torque)/Stabil. min. The Slope of the torque/time curve provides the rate of gel formation for the barrier blend being tested.
2. Trq -- Max=Maximum torque reached during the one hour test.
3. Stabil, min=Time in minutes to reach maximum torque. This is the time required to reach the "gel point" (where the torque/time curve reaches an inflection point and the torque drops rapidly to very low levels).
4. MI -- Stab.=Ratio of melt index (MI) determined for a sample after being held for 30 minutes at 250° C. to the MI of the sample before the 30 minute "cook" time. Employing a melt indexer operated at 230° C. with 2160 gram weight on the plunger the melt index (MI) of the sample is determined at the start of the test. The same test is re-run after the sample has been allowed to sit at the 250° C. temperature for 30 minutes. The ratio of the MI after the thirty-minute cook to the MI at the start is the MI -- Stab. reported in the table.
Superior Thermal Stability is indicated by the following:
1. Haake (slope)--lower slope indicates increased stability.
2. Trq -- Max--lower maximum torque indicates increased stability.
3. Stabil. min--longer time to reach maximum indicates increased stability.
4. MI -- Stab. ratios close to 1 are preferred. Ratios greater than about 0.70 indicate good thermal stability. Ratios greater than 1 (indicating that chain scission has occurred) are not satisfactory.
TABLE 1______________________________________Interaction Design for Eight Variables# EV!.sup.1 PA!.sup.2 SU!.sup.3 NY!.sup.4 Nylon.sup.5 SURLYN ®.sup.6______________________________________22 0.6 0.1 0.15 0.15 6 4 3 0.6 0 0.25 0.15 6/66 610 0.7 0 0.25 0.05 6 2 5 0.8 0.1 0.05 0.05 6/66 6 2 0.6 0.3 0.05 0.05 6/66 4 6 0.8 0 0.15 0.05 6/66 712 0.6 0.1 0.25 0.05 6 5 4 0.7 0 0.05 0.25 6/66 421 0.6 0.1 0.05 0.25 6/66 814 0.6 0 0.15 0.25 6/66 8 5 0.8 0.1 0.05 0.05 6/66 625 0.7 0.2 0.05 0.05 6 8 7 0.6 0.3 0.05 0.05 6 5 2 0.6 0.3 0.05 0.05 6/66 416 0.6 0.1 0.05 0.25 6 3 3 0.6 0 0.25 0.15 6/66 623 0.7 0.2 0.05 0.05 6/66 1 8 0.6 0 0.25 0.15 6 718 0.6 0 0.15 0.25 6 1 1 0.6 0.3 0.05 0.05 6 2 1 0.6 0.3 0.05 0.05 6 213 0.8 0 0.05 0.15 6/66 2 9 0.7 0 0.05 0.25 6 620 0.7 0 0.25 0.05 6/66 315 0.6 0.1 0.05 0.25 6/66 219 0.8 0 0.05 0.15 6 826 0.6 0 0.25 0.15 6/66 124 0.68 0.06 0.13 70.13 6/66 9 4 0.7 0 0.05 0.25 6/66 411 0.8 0.1 0.05 0.05 6 417 0.6 0.1 0.25 0.05 6/66 427 0.7 0 0.20 0.10 6 1028 0.7 0 0.15 0.15 6 529 0.7 0 0.21 0.09 6 1130 0.7 0 0.21 0.09 6 531 1.0 0 0 0 -- --______________________________________ .sup.1 Concentration of EVOH. .sup.2 Concentration of SELAR ® PA3426. .sup.3 Concentration of Zinc SURLYN ® Ionomer. .sup.4 Concentration of Nylon .sup.5 Type of Nylon employed. .sup.6 See Table 2 for SURLYN ® Ionomer identification and other variables considered in the design.
TABLE 2______________________________________Identity of Ionomers in Table 1No. used in % % %Table 1 Grade.sup.7 Acid.sup.8 Neut.sup.9 Free Acid Termonomer______________________________________1 1652 9 18 7.4 No2 Lab Grade 10 28 7.2 10% i-BA3 9520 10 71 2.9 No4 9020 10 73 2.7 10% i-BA5 9220 20 34 13.2 No6 Lab Grade 16 32 10.9 10% i-BA7 Lab Grade 19 56 8.4 No8 Lab Grade 14 62 5.3 10% i-BA9 9950 15 23 11.6 No10 9320 9 50 4.5 23.5% n-BA11 Lab Grade 20 40 12.0 No______________________________________ .sup.7 Commercial grade of SURLYN ® Ionomer available from E. I. du Pont de Nemours and Company unless indicated as a laboratory grade. .sup.8 Weight percent methacrylic acid in ionomer .sup.9 Neutralized with zinc.
TABLE 3______________________________________Interactions to be EvaluatedTerm Factor Effect______________________________________ 0 CONSTANT 1 EVOH! 2 PA! 3 SU! 4 NY! 5 Su.sub.-- Ac 6 Su.sub.-- Neut 7 EVOH!* PA! 8 EVOH!* SU! 9 EVOH!* NY!10 EVOH!*Su.sub.-- Ac11 EVOH!*Su.sub.-- Neut12 PA!* SU!13 PA!* NY!14 PA!*Su.sub.-- Ac15 PA!*Su.sub.-- Neut16 SU!* NY!17 SU!*Su.sub.-- Ac18 SU!*Su.sub.-- Neut19 NY!*Su.sub.-- Ac20 NY!*Su.sub.-- Neut21 Su.sub.-- Ac*Su.sub.-- Neut22 Ny.sub.-- type 6/66!23 Ter-ion No!______________________________________
TABLE 4__________________________________________________________________________Responsespin Intern Haake Trq Stab MI- Spencer OPV OPV ElmendorfTrial Flex T-form Haze (slope) Max min Stab. Impact dry wet MD TD__________________________________________________________________________22 3870 3.6 22.5 20.1 1294 60 0.96 7.4 0.003 0.199 23.1 25.23 5705 6.0 3.87 57.5 2285 38 0.59 10.2 0.009 0.221 12.9 14.95 2433 4.2 14.60 16.4 1095 60 1.14 2.4 0.000 0.089 12.1 13.610 3857 2.4 12.43 21.7 1347 60 0.70 20.6 0.000 0.087 22.3 25.62 2264 3.0 27.20 8.3 708 60 0.74 1.5 0.005 0.096 15.8 19.96 2736 5.6 9.56 21.6 1316 58 0.72 6.5 0.000 0.096 20.6 24.112 2521 4.8 9.5 27.4 1651 60 0.16 2.0 0.003 0.133 13.5 19.54 6738 5.6 1.51 52.6 1883 36 0.46 22.6 0.060 0.405 28.3 33.721 4836 5.6 12.77 42.9 1796 41 0.51 14.1 0.050 0.503 25.3 29.314 8446 8.0 1.46 58.5 1912 33 0.68 12.5 0.078 0.790 37.4 26.35 2880 6.4 14.53 15.5 940 60 1.01 3.2 0.000 0.109 14.8 16.425 2177 1.2 32.37 11.6 800 60 1.05 2.5 0.002 0.113 16.9 20.57 2378 2.4 24.97 10.8 729 60 1.04 1.5 0.002 0.135 17.3 21.22 2174 1.8 34.10 10.2 666 60 0.74 1.5 0.002 0.103 17.9 20.616 5065 3.2 13.53 38.7 1713 42 1.04 11.4 0.032 0.403 26.1 25.13 6323 8.0 4.98 59.7 2121 36 0.62 5.0 0.050 0.191 12.8 16.423 2969 5.6 40.27 11.7 843 60 0.93 4.2 0.010 0.104 16.4 16.98 4961 6.0 6.05 16.9 1148 60 0.69 2.6 0.023 0.274 13.0 23.318 7886 4.8 4.64 43.7 1263 29 1.29 21.7 0.081 0.600 36.7 48.01 2601 1.8 37.43 8.3 650 60 0.81 2.0 0.007 0.088 16.4 18.31 2282 3.0 36.43 10.4 770 60 0.82 2.3 0.006 0.110 17.5 20.813 4375 2.4 3.11 39.7 1556 40 0.47 23.5 0.013 0.127 23.7 24.79 4909 1.2 0.71 53.4 1894 36 0.57 7.4 0.040 0.290 23.1 26.420 3544 6.4 9.41 11.7 808 60 0.68 17.4 0.006 0.083 25.4 27.515 5022 5.6 11.76 50.1 1773 36 1.06 23.9 0.058 0.343 24.8 26.919 4120 3.0 0.83 38.2 1874 47 0.76 8.7 0.017 0.148 20.6 25.226 4258 6.0 8.83 16.3 792 46 0.45 4.4 0.009 0.074 21.5 27.924 3904 5.6 9.12 26.1 1270 46 0.32 12.5 0.007 0.108 21.3 22.34 6713 7.2 1.09 52.6 1883 36 0.58 22.8 0.041 0.249 25.9 27.111 2638 2.4 21.30 13.9 897 60 0.89 5.7 0.002 0.086 16.8 18.917 4163 s.0 12.57 14.7 958 54 0.27 18.7 0.006 0.161 22.8 25.927 3971 4.8 15.17 21.9 1351 55 0.34 24.6 0.005 0.105 26.9 25.128 4833 4.8 2.19 30.6 1578 47 0.77 12.5 0.017 0.172 19.7 22.329 3794 5.6 4.53 31.8 1536 46 0.66 12.3 0.008 0.147 19.4 21.030 2954 6.4 6.37 29.0 1604 56 0.70 11.1 0.002 0.161 19.1 21.531 1657 1.2 2.15 32.2 1599 47 -- 5.3 0.000 0.049 17.7 21.2__________________________________________________________________________
From analysis of the above data, the following determinations were made:
Internal Haze can be minimized by reducing the amorphous polyamide concentration, increasing the EVOH concentration, and increasing the semicrystalline polyamide concentration in the blend. Also, it was found that blends containing nylon-6 produce less internal haze than those containing copolymer nylon such as nylon-6/66, even though blends with nylon-6/66 process better than blends with nylon-6. But, when copolymer nylon such as nylon 6/66 is used in conjunction with an ionomer containing a softening ter-monomer, a less objectionable haze results than when the copolymer nylon is used with an ionomer without the softening ter-monomer.
OPV wet can be minimized by decreasing the semicrystalline polyamide concentration. Nevertheless, it was found that oxygen barrier properties at high humidity of EVOH/amorphous polyamide blends are improved by the addition of semicrystalline nylon. OPV wet can also be minimized by increasing the ionomer concentration, this despite the fact that ionomer itself is known to be both hygroscopic and provide poor oxygen barrier properties. Employing copolymer nylon such as nylon 6/66 instead of nylon-6 in the blend resulted in better high-humidity oxygen barrier.
Thermoformability appears to be improved by employing copolymer nylon such as nylon-6/66 instead of nylon-6. Thermoformability does not appear to be influenced by the concentration of EVOH semicrystalline nylon, amorphous nylon or ionomer. If the concentration of EVOH is high and the ionomer neutralization is high, thermoformability appears to improve. On the other hand, if the concentration of amorphous nylon is high and the ionomer neutralization is also high, thermoformability appears to be impaired.
Pinhole flex appears to be improved by employing copolymer nylon such as nylon 6/66 or by using ionomer containing softening ter-monomer such as one containing iso-butyl acrylate or n-butyl acrylate.
Thermal stability appears to be reduced when high concentrations of semicrystalline nylon are used.
Three-Component Example
To compare the effects on MI -- Stab. of percent free-acid and melt flow, the melt-blends in Table 5 were prepared by first making the ionomer/polyamide blend and then melt-blending with the EVOH (32 mol % ethylene). MI -- Stab. reported in Table 5 was measured as described above. In addition, up to 3 parts calcium stearate per hundred parts by weight of the EVOH/ionomer/polyamide blend was added to determine its effect. Some improvement in MI -- Stab. is seen, particularly in the case of blends with higher free-acid levels, when the calcium stearate is added.
Further, films of the EVOH/ionomer/polyamide were coextruded or blow-molded with various BYNEL® coextrudable adhesive grades as the tie layer (50E571 in a polypropylene-tie layer-EVOH blend -tie layer-polypropylene five-layer, blow-molded bottle, and 41E557, 4104, and 41E558 in a HDPE-tie layer-EVOH blend three-layer blown film). All BYNEL® coextrudable adhesives are available from E. I. du Pont de Nemours and Company. A qualitative comparison of adhesion of the anhydride modified tie layer to the EVOH blends showed that Blend No. 1 and Blend No. 2 in Table 5 had poor adhesion, while Blend No. 3 had significantly better adhesion, almost equivalent to EVOH alone.
TABLE 5__________________________________________________________________________Blend EVOH Nylon-6 Ionomer Free-Acid MI.sup.10 ofNo. wt. % wt. % wt. % wt. % Ionomer/Polyamide MI.sub.-- Stab.__________________________________________________________________________1 70 9 21 12.0.sup.11 2.0 0.522 70 4 26 7.4.sup.12 4.3 0.583 70 4 26 4.7.sup.13 11.9 0.78__________________________________________________________________________ .sup.10 Melt index (MI) of ionomer/polyamide blends measured essentially per ASTM D1238, condition E (grams of ionomer exiting a 0.0823 inch orifice in ten minutes (gm/10 min) with 2160 gram weight applied force) except at a temperature of 230° C. .sup.11 Ethylene/20% MAA, 40% zinc neutralized. .sup.12 Ethylene/12% MAA, 38% zinc neutralized. .sup.13 Ethylene/11% MAA, 57% zinc neutralized.
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A blend of ethylene/vinyl alcohol copolymers with crystalline nylon, and ionomers and optionally amorphous nylon that have a unique balance of properties and to packaging films, laminates, co-extrusions and containers prepared therefrom.
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FIELD OF THE INVENTION
[0001] The invention relates to boom operation on work vehicles such as, for example, loaders. It relates to a simple and inexpensive system and method of improving the safety, comfort, accuracy and repeatability/consistency in boom operation.
BACKGROUND OF THE INVENTION
[0002] On many work vehicles such as, for example, loaders and backhoes, the heights and angles of the work tools must be visually estimated and manually adjusted on a somewhat constant basis. This will quickly lead to fatigue for a normal human operator. On other work vehicles, a few positions, i.e., heights and angles, of the work tools are factory preset allowing the work tools to be automatically placed in those positions at the direction of the operator via a simple pushing of a button, a manipulation of a handle or some other simple operation. On still other work vehicles, kickout positions for the work tools may be programmed and modified by the vehicle operators from without or within the cab. However, the adjustment methods and/or mechanisms appear to be complex, cumbersome and/or expensive as they require sensor systems with complex linkages and/or adjustments by vehicle operators outside of the operator cab.
SUMMARY OF THE INVENTION
[0003] The inventors recognize that conventional boom height sensing and adjustment mechanisms are somewhat cumbersome and/or expensive and have determined that such is unnecessary. They have invented a simplified method of tracking the position of a boom for a work vehicle. The method uses a height or angle sensor of very simple design which comprises a spring loaded follower arm biased such to constantly exert pressure against the boom at all boom positions. Thus, the follower arm rotates as the position of the boom changes and causes a change in electrical potential across an electromechanical device such as, for example, a potentiometer. This change in electrical potential is fed to a signal processing device or onboard computer such as, for example, a chassis control unit and the operator. After electronically sensing the boom position, it is possible to set kickout positions, return to dig positions and/or return to carry positions from the cab with a mere push of a button or operation of a switch at desired boom heights. A boom manipulating control lever, used by the operator to manipulate the boom from within the cab normally has at least one detent or locked position. The boom may be automatically set to move to a set/stored position by moving the control lever to the detent position. Once the boom reaches the position associated with the stored signal the chassis control unit sends a signal to release the control lever from the detent position and allows it to return to a neutral position. Thus, the movement of the boom stops upon release of the control lever.
[0004] The system is extremely simplified and does not require a linkage system between the sensor and the boom as in conventional systems. Thus, the sensor is capable of being attached with a minimum of modifications to the work vehicle as it is merely rigidly affixed to a portion of the vehicle and connected via electrical cable or wirelessly to the height estimating device. Conveying the position data to the chassis control unit may be accomplished through a flexible electrical cable or wirelessly via electromagnetic waves.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Embodiments of the invention will be described in detail, with reference to the following figures, wherein:
[0006] FIG. 1 is view of a work vehicle in which the invention may be used;
[0007] FIG. 2 is an oblique view of an exemplary embodiment of the assembled invention showing the boom in a heightened or kickout position;
[0008] FIG. 3 is a side view of the embodiment illustrated in FIG. 2 ;
[0009] FIG. 4 is a side view of an exemplary embodiment of the assembled invention showing the boom in a lowered or return position;
[0010] FIG. 5 is a rearward view of the sensor;
[0011] FIG. 6 is a frontal view of the sensor;
[0012] FIG. 7 is an exploded view of the sensor; and
[0013] FIG. 8 is an exemplary embodiment of a functional diagram of the invention.
DETAILED DESCRIPTION
[0014] FIG. 1 illustrates a work vehicle in which the invention may be used. The particular work vehicle illustrated in FIG. 1 is an articulated four wheel drive loader having a main vehicle body 10 that includes a front vehicle portion 100 pivotally connected to a rear vehicle portion 200 by vertical pivots 220 , the loader being steered by pivoting of the front vehicle portion 100 relative to the rear vehicle portion 200 in a manner well known in the art. The front and rear vehicle portions 100 and 200 are respectively supported on front drive wheels 101 and rear drive wheels 201 . An operator's station 210 is provided on the rear vehicle portion 200 and is generally located above the vertical pivots 220 . The front vehicle portion 100 includes a mast 120 having a right mast portion 120 a and a left mast portion 120 b . The front and rear drive wheels 101 and 201 propel the vehicle along the ground and are powered in a manner well known in the art.
[0015] Mounted on the front vehicle portion 100 is a boom 110 that is partly formed by first and second boom arms 110 a and 110 b respectively. The first and second boom arms 110 a and 110 b are connected by a transverse cross tube 111 that is welded to each of the first boom arm 110 a and the second boom arm 110 b . The rear end of the boom 110 is connected to the mast 120 by transverse pivots 125 and a loader bucket 115 is mounted on the forward end of the boom 110 by transverse pivots 116 . The boom 110 is rotated about the transverse pivots 125 by hydraulic lift cylinders (not shown).
[0016] FIG. 2 illustrates an exemplary embodiment of a boom position sensing device 300 of the invention mounted to the mast 120 . In this particular embodiment, the sensing device 300 is mounted to a side wall 121 of the mast 120 via screws 301 . In this particular embodiment, a spring loaded follower arm 312 is biased against the underside of the first boom arm 110 a such that the follower arm 312 exerts pressure against the first boom arm 110 a at all rotational locations. Thus, as shown in FIG. 3 and FIG. 4 , the spring loaded follower arm 312 of this embodiment contacts the underside of the boom 110 a at all points of rotation for the boom 110 without the necessity of a physical attachment to the boom 110 and the accompanying complexities associated with such an attachment.
[0017] FIG. 5 illustrates an exemplary embodiment of the boom position sensing device 300 of the invention. As shown in FIG. 5 , the boom position sensing device 300 includes a body 309 , a follower assembly 310 and a potentiometer assembly 306 .
[0018] The body 309 includes a first body portion 302 and a second body portion 303 , the first and second body portions 302 and 303 being rigidly connected to each other via bolts 304 a and locknuts 304 b . The first body portion 302 includes a L channel portion 302 a and a C channel portion 302 b . The L channel portion 302 a contains two holes 301 a for attaching the entire boom position sensing device 300 to the outer wall 121 of the mast 120 via bolts 301 . It also contains two holes 304 a for attaching the first body portion 302 to the second body portion 303 via bolts 304 a and locknuts 304 b . The C channel portion 302 b contains two holes 307 a for attaching a potentiometer assembly 306 via locknuts 306 e and bolts 306 c and a third hole 306 j to allow the passage of shaft 316 through the wall of the C channel portion 302 b and into the potentiometer 306 b . Finally, the C channel portion 302 b contains an anchor bolt hole 320 a for attaching a spring anchor bolt subassembly 320 .
[0019] The second body portion 303 contains two holes 304 b for attaching the first body portion 302 to the second body portion 303 . The second body portion 303 also contains two additional holes 315 a and 316 a . Attached to the second body portion at holes 315 a is a stop assembly 315 to restrict rotational motion on the follower arm 312 . Press fitted into the hole 316 a and toward a first end of a shaft 316 of the follower assembly 310 is a shaft bushing 310 a to enhance rotational movement of the shaft and to restrict axial movement of the spring bushing 318 . Washers 317 are placed along the shaft 316 on either side of the spring bushing 318 , a first end of the follower arm 312 is press fitted onto the shaft at a position next to the spring bushing 318 , and a snap ring is assembled to a snap ring groove 316 a toward a second end of the shaft 316 to hold all of the washers 317 and the spring bushing 318 in place as well as to restrict axial movement of the shaft 316 . A first end of torsional loading spring 314 is anchored to spring anchor 320 while a second end of torsional loading spring 314 constrains and biases the follower arm 312 against the underside of the first boom arm 110 a . Attached to a second end of the follower arm 312 is a roller assembly 313 which includes a roller wheel 313 a and bushing 313 d as well as a roller bolt 313 b and a locknut 313 c to restrict all motion of the roller wheel 313 a and the bushing 313 d relative to the roller bolt 313 b excepting rotational motion.
[0020] The follower assembly 310 includes the follower arm 312 , the torsional spring 314 , the shaft 316 , the shaft bushing 310 a , the plurality of spacers 317 , the snap ring 330 , and the spring bushing 318 .
[0021] Attached to the C channel portion 302 b is a sensor or potentiometer assembly 306 which includes a bracket portion 306 a and a sensor portion or potentiometer 306 b . The bracket portion 306 a and the potentiometer 306 b are attached to opposite sides of a C channel wall 302 c via bolts 306 c , washers 306 d and locknuts 306 e . On assembly of the potentiometer assembly 306 , rubber washers 302 f are placed between the C channel wall 302 c and the potentiometer 306 b as a seal against the environment. On assembly of the entire boom height sensing device 300 the second end of the shaft 316 protrudes through a hole 306 g in the bracket portion 306 a and into a hole 306 h in the potentiometer 306 b where it is keyed in a well known manner to a conventional rotor in the potentiometer 306 b such that a change in the angle of the shaft 316 results in a proportional change in the potential across the potentiometer 306 b.
[0022] As illustrated in FIG. 8 , the detected signal from the boom position detector 300 is transmitted to the chassis control unit 500 via electrical wire or wirelessly through electromagnetic waves. The first rocker switch 601 and the second rocker switch 602 are activated with a push. Subsequent to activation, the operation of the first rocker switch 601 and/or the second rocker switch 602 sends a momentary signal to the chassis control unit 500 which causes the chassis control unit 500 to record the current signal value from the boom position detector 300 . The chassis control unit 500 then compares the recorded signal from the signal recorder 510 and the detected signal from the boom position detector 300 and sends a signal to unlock the control lever 700 from the detent position when the recorded signal is approximately equal to the detected signal. The chassis control unit 500 is capable of storing additional detected signal values, i.e., after storing a value for the first rocker switch 601 , it may store an additional value for the second rocker switch 602 . Thus, boom kickout values and return to carry values may coexist in the chassis control unit increasing the convenience and ease of operation of the work vehicle.
[0023] Having described the illustrated embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims. For example, it is possible for a dial in potentiometer or a digital device with a position readout to be calibrated to the potentiometer 306 b such that the position could be dialed or typed in by the operator prior to placing the boom in that position.
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A boom position detecting device that detects a boom angle on a work vehicle for a boom that rotates about a pivot. The device includes a boom angle follower and positional sensor. The boom angle follower includes a spring and a follower arm arranged such that the spring biases the follower arm against a surface of the boom and keeps the follower arm in contact with the boom throughout a rotational movement of the boom about the pivot. The positional sensor is physically connected to the boom angle follower and detects at least one boom angle.
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FIELD OF THE INVENTION
[0001] The present invention concerns the field of surgery, more particularly the field of cancer surgery and is related to a medical device or instrument.
STATE OF THE ART
[0002] Most cancer cells first develop in a primary tumor site such as the breast, colon or lung, but then cells from these cancers can spread, or metastasize, to other parts of the body where they may form new tumors.
[0003] A possible strategy for the treatment of cancer corresponds to a local treatment of the tumor, wherein cancer is attacked at a specific site. Different techniques have been developed on the basis of said strategy. Ablation surgery in order to remove tumors is certainly the most common local treatment used worldwide. However, other local treatment techniques also exist, among which is radiation therapy, wherein radioactive particles, seeds or rods implanted directly into a tumor are used. This type of radiation treatment is called brachytherapy.
[0004] New local treatment techniques such as radiofrequency (RF) ablation procedure and other similar interventional radiology catheter ablation procedures reveal to be particularly promising for patients whose cancers cannot be treated surgically.
[0005] The device used in the radiofrequency ablation technique generally comprises a needle which is placed through the skin and into the tumor. The needle is linked to a radiofrequency generator such that when a radiofrequency is sent through the needle, the needle is heated and destroys the tumor. This procedure is performed under conscious sedation and most patients can go home the same day.
[0006] RF treatment presents several advantages:
it is a new local treatment option for cancer; it is a minimally invasive method; its safety has been proven over many years in thousands of people; it is less risky and has fewer complications compared to surgery; generally, only local anesthesia is required; it may be done as an outpatient procedure, or shorten hospital stay; most patients can resume normal activities within a few days; it can be repeated if necessary; and it may be combined with other treatment options, such as chemotherapy.
[0016] However, the capabilities of RF technique are nowadays limited as there is a real technical difficulty in controlling precisely the region to be destroyed with the existing RF devices. Indeed, the conception of said devices is such that the heating of the tissues tends to propagate beyond the tumour site. In some cases, cell's dehydration stops the heating propagation and then, the treatment's effectiveness. Currently, some cooled devices and expandable electrodes allows bigger regions to be destroyed. Then, increasing the destruction volume is possible, but the precise control of the destruction region becomes to be reached. This is important in some organs where the lesion of neighbour organs and structures, like important vessels, represents a real and still unsolved problem.
[0017] Among the solutions proposed in the prior art in order to solve this problem, it has been suggested in document U.S. Pat. No. 5,507,743 to use a RF ablation device comprising a variable pitch helical electrode capable of wrapping the tumor. However, the use of said device presents a serious drawback from a practical point of view, as it is known that increasing the distance between the two poles of the electrode produces two undesirable effects. The first undesirable effect is that the physician must increase the RF generator power, so as to compensate the bigger distance to destroy. However, increasing the power heats the cells closer to the active electrode to temperatures as high as 90 or 100 Celsius degrees, dehydrating these cells and stopping the heating effect (the heating and consequently the destruction effect is propagated through the cell's water). The second undesirable effect is that more distant tissues are easily cooled by surrounding vessels, thereby increasing the risk of non destruction of all tumoral cells.
[0018] In other words, there is still a need for a satisfying device which could be used in RF ablation techniques in order to destroy by heating a tumor site inside an organ.
AIMS OF THE INVENTION
[0019] The present invention aims to provide a medical device or instrument and a process adapted for the ablation (i.e. destruction) by radiofrequency technique of a target volume, such as a tumor, located inside or at an anatomical organ such as prostate, kidney, adrenal glands, breast, lungs and pancreas, an even brain, which would not present the drawbacks of the solutions of the prior art.
[0020] In particular, the present invention aims to provide a device and a process which would ensure, in operating conditions, a total but specific destruction of a predetermined unsafe tissue volume inside or at said organ, while preserving the surrounding safe tissues.
[0021] Another aim of the present invention is to provide a device and a process which could be used or carried out both easily and securely.
SUMMARY OF THE INVENTION
[0022] The present invention is related to a medical device adapted for the ablation of a target volume inside an anatomical organ, said device comprising as elements a main body, stabilising means for stabilising the device relatively to the organ and heating means in the form of a bipolar electrode comprising parts activable by an external radiofrequency generator for heating said target volume, wherein said bipolar electrode comprises a first element having the form of a central anchoring member, and a second element having the form of at least two concentric helices of predetermined diameter and length, said helices surrounding the central anchoring member.
[0023] Advantageously, said central anchoring member may take the form of a central needle or of an extremely thin helix.
[0024] Preferably, said helices are rigid i.e. said helices are not deformable by simple external manual pressure (not deformable by direct manipulation).
[0025] Preferably, the medical device can adopt at least one rest configuration wherein the bipolar electrode is unactivable and is folded-up inside the stabilising means and the main body, and at least one working configuration wherein the bipolar electrode protrudes outside the stabilisation means so as to deploy both the anchoring member and the helices, said helices thereby forming a cage-like structure around said anchoring member, with an internal face facing the central anchoring member and an external face oriented in an opposite manner (exposed to the environment), and wherein said bipolar electrode is activable so as to have a passive pole and an active pole.
[0026] It is meant by “activation of the electrode” the circulation inside said electrode of a current of electric or electromagnetic type from one area of said electrode which forms the active pole to another area of said electrode which forms the passive pole.
[0027] According to a first preferred embodiment of the medical device, in the working configuration at least one of the helices is activable independently from the others, only on its internal face, so as to form the active pole of the bipolar electrode, while the passive pole of the bipolar electrode can be formed either by the central anchoring member or by the external face of the helix forming the active pole or by the external face of an helix of smaller diameter than the helix forming the active pole.
[0028] According to a second preferred embodiment of the medical device, in the working configuration at least one of the helices is activable independently from the others, on both its internal face and its external face, so as to form the active pole of the bipolar electrode, while the passive pole of the bipolar electrode can be formed either by the central anchoring member or by a helix of smaller diameter than the helix forming the active pole.
[0029] In the present invention, the helices of the medical device may be activable at least on one fraction of their length, and possibly on their full length.
[0030] Preferably, in the rest configuration, the device according to the invention has the following degrees of freedom in a referential system (O,X,Y,Z) centred at the centre of the main body:
Rotation around the Z axis; Rotation around the Y axis; Translation along the X axis; Translation along the Y axis; Translation along the Z axis.
[0036] Preferably, in the working configuration, the anchoring member of the bipolar electrode has one degree of freedom in a referential system (O,X,Y,Z) centred at the centre of the main body corresponding to a translation along the X axis, while the helices have two degrees of freedom each, one corresponding to a translation along the X axis, and the other to a rotation around the X axis.
[0037] Preferably, in the working configuration any translation or rotational movement of the main body and of the stabilising means is blocked.
[0038] Preferably, the medical device of the invention is conceived such that the positioning of its different elements relatively to the target volume and relatively to each other and the activation state of said parts of the bipolar electrode are able to be controlled by controlling means.
[0039] Advantageously, said controlling means comprise a robot.
[0040] The present invention is also related to a surgical assembly comprising the medical device according to any one of the preceding claims, coupled to controlling means.
[0041] Preferably, said controlling means comprise a robot.
[0042] Preferably, the surgical assembly further comprises a 3D-navigation system. It is meant by “3D-navigation system any device able to take 3D informations on the position in real time of an object such as a camera or ultrasound measurement device (echographic navigation system).
[0043] Preferably the controlling means also comprise a computer coupled to the robot via interfacing means such as an A/D converter.
[0044] Preferably, said assembly is linked to a fixed support such as a surgical table.
[0045] Another object of the present invention is a process for the destruction of a target volume inside an anatomical organ by radiofrequency ablation technique using the medical device or the surgical assembly as disclosed above, said process comprising the following steps:
determining parameters comprising at least the anatomical features (size, shape, position, . . . ) of the target volume to be treated; on the basis of said parameters, defining at least the number of helices to use in the bipolar electrode, the passive and active poles of the bipolar electrode, the sequence of activation of the bipolar electrode, and the intensity and time of activation of said bipolar electrode; introducing said medical device inside the patient; once the target organ is reached, positioning the medical device relatively to the target volume; performing the treatment procedure of the target tumor following the predetermined parameters.
[0051] The present invention also concerns a process for the destruction of a target volume inside an anatomical organ by radiofrequency ablation technique using the medical device or the surgical assembly disclosed hereabove.
[0052] Preferably, said process comprises the following steps:
[0000] by means of the 3D navigation system,
[0000]
establishing a surgical protocol according to different parameters including the anatomical features of the target volume to be treated, said surgical protocol defining namely the sequence and type of movements of the medical device and of its different elements, the number of helices to use in the bipolar electrode, the definition of the passive and active poles of the bipolar electrode, the sequence of activation of the bipolar electrode, the intensity and time of activation of said bipolar electrode;
manually introducing said medical device inside the patient and approximately positioning said device relatively to the target volume;
starting the automatic operating of the robot so as to perform the surgical procedure under automatic control following the pre-established surgical protocol;
monitoring the surgical procedure and possibly restoring a manual control on the device, in case of security problems.
[0057] Another object of the invention concerns the use of said medical device or said surgical assembly for the treatment of a target volume inside an anatomical organ selected from the group consisting of kidneys, lungs, liver, breast, prostate and brain.
SHORT DESCRIPTION OF THE DRAWINGS
[0058] FIG. 1 represents an overview of the medical device according to the present invention.
[0059] FIG. 2 represents said medical device in rest configuration (pre-operative position with the electrode folded-up inside the main body of the device).
[0060] FIG. 3 a represents a detailed view of the bipolar electrode comprised in a device according to the invention, and including a needle shaped central pole and two cage-like helical poles.
[0061] FIG. 3 b represents a front view of said cage-like helical poles.
[0062] FIG. 4 represents the main body of a medical device provided with its stabilizing means, and shows the different degrees of freedom for said medical device.
[0063] FIG. 5 represents a medical device according to the invention, with its bipolar electrode in a first operating position, wherein the needle-like pole arranged inside a target volume and one helical pole deployed and arranged around said target volume.
[0064] FIG. 6 represents a medical device according to the invention, with its bipolar electrode in a second operating position, wherein two helical poles are deployed around said target volume.
[0065] FIG. 7 illustrates an overview of a surgical system comprising the medical device according to the present invention which is linked to a robotic arm and controlling means, and is fixed via the robotic arm to a surgical table or floor.
DETAILED DESCRIPTION OF THE INVENTION
[0066] As illustrated on FIG. 1 , the medical device 1 according to the invention comprises as elements a main body 2 , stabilizing means 3 , and a bipolar electrode 10 .
[0067] Advantageously but not necessarily, said device 1 , as shown on FIG. 7 , is in fact part of an assembly comprising also controlling means. Said controlling means may advantageously comprise a robot supported by a robotic arm 6 and piloted by computerising means 7 , for controlling the operating state of the device 1 .
[0068] The main body 2 and the stabilizing means 3 of the device 1 according to the invention have both a distal end, 20 and 30 respectively, and a proximal end 21 and 31 respectively.
[0069] The main body 2 is attached by its distal end 20 to the proximal end 31 of the stabilizing device 3 , while its proximal end 21 can be attached to the robotic arm 6 of a robot.
[0070] The stabilizing means 3 is configured so as to allow its positioning at the outer surface of a target volume or organ in operating conditions, thereby contributing to the stabilisation of said target relatively to the device. For example, as shown on FIG. 1 and more detailed on FIG. 4 , the stabilising means 3 may have a hollow cylindrical shape, with its walls delimiting an internal cavity 33 and a more external cavity 32 .
[0071] The bipolar electrode 10 , as further shown on FIG. 1 , comprises a central needle 5 . The needle 5 of the electrode 10 has a distal end 51 in the form of a tip so as to be able to penetrate inside a target tissue volume in operating conditions. Said needle 5 has also a proximal end 52 , by which the needle 5 of the electrode 10 may be linked to an external radio-frequency (RF) source or generator so as to constitute a passive pole of the electrode 10 that is to say in operating conditions an electric or electromagnetic current provided by the radiofrequency generator may flow towards it.
[0072] The bipolar electrode 10 also comprises at least two helical or coiled elements 4 ′, 4 ″, . . . which are concentric helices able to surround the needle 5 and to form a cage-like structure around said needle 5 , when deployed according to a working configuration (see hereafter). Each of said helices is defined by its diameter D and its length L. Another feature characterizing an helix is its pitch P.
[0073] Preferably, the diameter D of all the helical elements 4 ′, 4 ″, . . . are a multiple of a distance d, d being the diameter of the smallest helix, i.e. the distance between the smallest helical elements 4 ′ and the main axis A of the needle 5 .
[0074] According to the present invention, this distance d can be different depending on the embodiment of the medical device 1 and on the target organ (prostate, kidneys, breast, . . . ) to be treated and its anatomical features (size and shape, namely).
[0075] Each of the helical elements 4 ′, 4 ″, . . . of the electrode 10 has a distal end 41 ′, 41 ″, . . . and a proximal end 42 ′, 42 ″, . . . . The proximal ends 42 ′, 42 ″, . . . are linked to the external radio frequency (RF) generator, while the distal ends 41 ′, 41 ″, . . . are free.
[0076] As illustrated in FIG. 3 b , for each of said helical elements 4 ′, 4 ″. . . , an internal face 43 ′, 43 ″, . . . arranged towards the central needle 5 and an external face 44 ′, 44 ″, . . . arranged towards the outside environment can be defined.
[0077] According to a first preferred embodiment of the invention, only the internal faces 43 ′, 43 ″, . . . of said helical elements are activable separately and independently by the controlling means so that the internal face of one of said helices may constitute the active pole of the electrode 10 , that is to say in operating conditions, an electric or electromagnetic current flows from it to the area of the bipolar electrode forming the passive pole.
[0078] On the contrary, each of the external faces 44 ′, 44 ″, . . . of the helical elements 4 ′, 4 ″, . . . are susceptible to form the passive pole of the electrode 10 , so that in operating conditions an electric or electromagnetic current may flow from the active pole to the external face of one of the helices forming the passive pole.
[0079] In this first embodiment, the passive pole of the bipolar electrode 10 may also be formed by the central needle 5 .
[0080] According to a second preferred embodiment of the invention, the helices are activable separately and independently by the controlling means on both their internal faces 43 ′, 43 ″, . . . and their external faces 44 ′, 44 ″, . . . so that one of said helix may constitute the active pole of the electrode 10 , that is to say in operating conditions, an electric or electromagnetic current flows from it to the area of the bipolar electrode forming the passive pole.
[0081] In said second embodiment, the passive pole may be formed either by another helix of smaller diameter than the helix forming the active pole, or by the central needle 5 .
[0082] It should be noted that the composition of the helices is adapted according to the activation scheme to be achieved. For example, in the hereabove mentioned second embodiment, wherein the the helices are activable on both faces, the helices are entirely made of an adequate biocompatible and conducting metallic component. Comparatively, in the first embodiment, wherein the helices are activable only on their internal face, only said internal face is made of such a metallic conducting component, while the external faces of the helices is made of an adequate biocompatible and isolating polymeric component.
[0083] It should be noted that in both said first and second embodiments, the helices are activable either along their full length or only along at least one fraction of said length. It means that in the case wherein the helices are activable only on one or more fractions of their length an adequate isolation pattern of the helices has to be provided.
[0084] According to the invention, the device 1 may adopt at least one rest configuration as shown on FIG. 2 , wherein the bipolar electrode 10 (needle 5 +helices 4 ′, 4 ″, . . . ) is folded up inside the main body 2 and the stabilising means 3 (bipolar electrode hidden from the outside environment) and wherein the bipolar electrode 10 cannot be activated (is unactivable).
[0085] It means that in said rest configuration, both the ends 41 ′, 41 ″, . . . and 42 ′, 42 ″, . . . of the helices 4 ′, 4 ″, . . . are folded up inside the stabilizing device 3 and main body 2 .
[0086] Moreover, in rest configuration, the medical device 1 as a whole presents different degrees of freedom.
[0087] More precisely, as illustrated on FIG. 4 , in the referential system (O, X, Y, Z) centred at the centre O of the main body 2 of the medical device 1 , the following degrees of freedom are associated to the medical device 1 :
rotation around the Z axis; rotation around the Y axis; translation along the X axis; translation along the Y axis; translation along the Z axis.
[0093] According to the invention, the device 1 may also adopt at least one working configuration, wherein the bipolar electrode 10 (needle 5 and at least one helix 4 ′) protrudes outside the stabilising means, beyond the distal end 30 of said stabilising means 3 . The distal ends 41 ′, 41 ″, . . . of the helical elements 4 ′, 4 ″, . . . can be deployed out from the stabilizing device 3 , while the proximal ends 42 ′, 42 ″, . . . of said helical elements remains inside the stabilizing device 3 and main body 2 . In addition, in working configuration the bipolar electrode 10 is activable. It means that the bipolar electrode can be activated or not, depending on its activation state.
[0094] An example of such a working configuration is represented on FIG. 1 .
[0095] In said working configuration, the device 1 is such that only the bipolar electrode 10 is able to move, the needle 5 presenting one degree of freedom, which corresponds to a translation along the X axis, while the helices 4 ′, 4 ″, . . . of the electrode 10 are able to perform a translation along the X axis and/or rotation around the X axis.
[0096] Therefore, the working configurations of the medical device 1 differ from each other at least by a different orientation of the bipolar electrode 10 that is to say of the needle 5 and/or of the helices 4 ′, 4 ″, . . . , relatively to the main body 2 in the referential system mentioned hereabove (see FIG. 6 ).
[0097] It should be noted that the combination of both movements (translation+rotation around X axis) allows in operating conditions the positioning of the helices 4 ′, 4 ″, . . . of the electrode 10 around a target volume (target tumor or tumoral target region) with one unique entry point into the organ, following a corkscrew-like movement.
[0098] It should also be noted that the medical device 1 of the invention is conceived in such a manner that the movements of the main body 2 and of the stabilisation means 3 are locked before the needle 5 and the helices 4 ′, 4 ″. . . of the electrode 10 can move. It means that in working configuration, the main body 2 and the stabilising means 3 cannot move. In addition, it is also possible to lock the robotic arm 6 of the assembly.
[0099] All these movements of the medical device 1 are done with a near millimeter precision, under the control of the controlling means.
[0100] Advantageously, all these movements are done via the robotic arm 6 of a robot and by means of different activators and micro-activators.
[0101] In this case, all the activators or micro-activators necessary for these movements can be placed in the main body 2 of the device 1 , or in the robotic arm 6 or somewhere else in the assembly itself.
[0102] These activators and micro-activators necessary for the described movements of the medical device 1 can be of several types, including electrostatic, magnetic, piezo-electric, thermic, shape memory allow (SMA), fluidic and electro-rheologic ones
[0103] An important feature of the present device is the fact that the configuration the device 1 , as well as the activation state of the bipolar electrode are contrallable by the controlling means.
[0104] Furthermore, it should be noted that the composition and dimensions of the different elements of the device 1 i.e. the main body 2 , the stabilizing device 3 , the needle 5 or other equivalent anchoring member and the helices 4 ′, 4 ″, . . . of the electrode 10 are compatible with their technical use (the prostate, kidneys, adrenal glands, lungs, etc . . . ), in particular in terms of biocompatibility, and can be easily adapted from the present description by the man skilled in the art.
[0105] In practice, the anchoring member (needle 5 ) and the helices 4 ′, 4 ″, . . . always work together so as to form the bipolar electrode 10 , with the electric or electromagnetic current flowing from the more external pole (the active pole) to the more internal pole (passive pole) as defined hereabove.
[0106] This movement of the current from the periphery to the center of the medical device allows a better control of the region to be destroyed by heating. The present apparatus and associated process thus prevent undesirable heating of the surrounding tissues located immediately outside the active helix.
[0107] In a first case, as illustrated in FIG. 5 , wherein the target volume 100 (target tumor or tumoral region) is sufficiently small, the controlling means and thus possibly the robot, control the different elements of the device in such a manner that in the working configuration the needle 5 and the smallest helix 4 ′ protrude outside the main body and stabilising means 3 , the needle 5 penetrating inside the target volume 100 and the helix 4 ′ wrapping said target volume 100 , while helix 4 ″ of greater diameter is folded up inside the main body 2 and stabilising means 3 . The needle 5 operates as a passive pole, while the internal face 43 ′ of the smallest helix 4 ′ operates as the active pole and the external face 44 ′ of said helix 4 ′ remains inactive i.e. is not activated by the RF external generator.
[0108] In a second case, as illustrated in FIG. 6 , the target volume 100 to be destroyed by heating is bigger than the diameter of the smallest helix 4 ′. Therefore, the controlling means and thus possibly the robot control the device in such a manner that the needle 5 as anchoring member and the helices 4 ′, 4 ″ protrude outside the main body 2 and stabilising means 3 , the needle 5 and the helix 4 ′ penetrating inside the target volume 100 and the helix 4 ″ wrapping said target volume 100 . The passive pole is the external face 44 ′ of the smallest helix 4 ′ and the active pole is the internal face 43 ″ of the immediately bigger helix 4 ″. (The other faces of the two helices 4 ′ and 4 ″, i.e. the internal face 43 ′ of the smallest helix 4 ′ and the external face 44 ″ of the immediately biggest helix 4 ″ are inactive, i.e. not activated by the external RF generator).
[0109] Similarly, if necessary, it is possible to destroy even bigger target volumes 100 by deploying and activating through the controlling means other helices 4 ′″, 4 ″″ . . . , of bigger diameter as mentioned previously. So, the technical features of the device 1 , and namely the number of helices 4 ′, 4 ″, 4 ′″, 4 ″″, . . . in the device 1 , depend on the conception of said device 1 and can be adapted according to one or more target organs and their anatomical characteristics and specificities.
[0110] It is thus possible to adapt the diameter of the helix to the volume of the target volume by selecting the appropriate external helix.
[0111] In practice, the use of the device and assembly according to the invention can be done according to a process comprising the following steps, in the embodiment wherein the controlling means comprise a micro-robot.
[0112] Before the surgery, the robot orders the 3D navigation system to take informations such as images about the tumor and target organ. Said informations are treated by the robot (controlling means) so as to determine a surgical protocol (sequence in time of movements of the device 1 , number of helices to be protruding, definition of the passive and active poles, intensity and length of the activation of the electrode, . . . ) according to parameters including anatomical features (position, shape, size, . . . ) of the tumor and organ to be treated.
[0113] During the surgery, the surgeon introduces the medical device in rest configuration inside the patient using the 3D-navigation system which allows the monitoring in real time of the position of both the medical device and the target organ. Once the target organ is reached, the surgeon positions approximately the medical device relatively to the target organ and starts the automatic operating of the robot according to the predefined surgical protocol. The surgeon lets the robot operating but he has the possibility to monitor the whole surgical procedure through the navigation system.
[0114] Using its robotic arm 6 the robot readjust the position of the device, which is still in rest configuration, relatively to the target organ and namely the precise positionning of the stabilizing means 3 at the outer surface of the target organ so as to align the main axis X of the medical device 1 with the tumoral region 100 to be destroyed by heating.
[0115] The stabilizing device 3 thus gives to the navigation system an important fixed point and allows an easier penetration of the electrode 10 into the patient's skin or organ's surface.
[0116] The robot then orders the configuration change of the device into the working configuration, with the deployment of the needle 5 until it reaches the tumor or tumoral region center and the deployment of the smallest helix 4 ′ in such a manner that said helix 4 ′ may wrap the tumor or tumoral region 100 to be destroyed. The actuators responsible for this deployment and the degrees of freedom have been described above.
[0117] The robot then activates the poles of the electrode 10 as described above in the first case.
[0118] When the tumor or tumoral region 100 is bigger than the diameter of the smallest helix 4 ′, the robot orders the deployment of one or more additional helices 4 ″, 4 ′″, 4 ″″, . . . so as to completely wrap the tumoral region to be destroyed by heating. The activation of the helices is done as in the second case described above.
[0119] The tumoral regions wrapped by the helical cage-like helices 4 ′, 4 ″, 4 ′″, . . . of the electrode 10 are thus destroyed by heating with no damage to surrounding tissues and only a few penetration points in the patient's skin or on the surface of the organ (the prostate, kidneys, adrenal glands, lungs, etc . . . ). The present device 1 thus requires a minimally invasive intervention.
[0120] It should be noted that the robot 1 with its robotic arm 6 is provided with securing means activable in case of abnormalities for interrupting the working of the robotic system so that the surgeon may continue manually the surgical procedure.
[0121] In this manner, the medical device of the present invention offers all the guarantees of security for the patient.
[0122] As illustrated hereabove, the medical device 1 and method according to the present invention thus offer undeniable advantages over the state of the art.
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The present invention is related to a medical device ( 1 ) adapted for the ablation of a target volume inside an anatomical organ, said medical device ( 1 ) comprising as elements a main body ( 2 ), stabilising means ( 3 ) for stabilising the device relatively to the organ and heating means in the form of a bipolar electrode ( 10 ) comprising parts activable by an external radiofrequency generator for heating said target volume, wherein said bipolar electrode comprises a first element having the form of a central anchoring member ( 5 ), and a second element having the form of at least two concentric rigid helices or coils ( 4′,4″, ) of predetermined diameter (D) and length (L), said helices surrounding the central anchoring member ( 5 ). The present invention also concerns a surgical assembly comprising said medical device and controlling means as well as a process for the specific destruction a target volume inside an organ by means of said medical device or surgical assembly.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and a device for sealing the place of penetration of a pipeline, especially a riser pipeline, in the wall of a submerged structure, which pipeline extends generally horizontally at the place of penetration and is connected to a generally vertical section inside the structure, wherein an annular sealing device which is flexible at least in the axial direction of the pipeline is placed coaxially with the pipeline at the place of penetration, one end of the sealing device being connected tightly to the wall while its other end is tightly connected to the pipeline.
2. The Prior Art
One of the most desirable methods for transporting fluids like oil, gas, slurry, and water to and from offshore structures resting on the sea bed is through pipeline systems. The part of the pipeline system resting on the sea bed is called a submarine pipeline, while the part which is connected to the structure is called the riser.
The riser is vulnerable to many problems which range from corrosion and overstressing to damage caused by supply vessels. Because of these problems the riser is subjected to thorough design considerations. In order to avoid wave loads and damage due to supply vessels, there has been a tendency in resent years to place the riser inside the platform structure. This necessitates the penetration of the pipeline through the wall of the platform structure. The area inside the platform structure where the riser is located can either be a wet or dry environment. Since the riser is located inside the platform structure and thus is in the vicinity of areas where people work, any damage to the riser can cause loss of human life. In order to maximize safety, the riser inside the platform structure must be inspected periodically and minor damage repaired to avoid catastrophic failure.
Underwater inspection and repair of the riser in a confined space inside the platform structure are very hazardous operations. This space must therefore be capable of being dewatered in order to allow inspection and/or repair of the riser in a dry environment.
Therefore, whether the riser is in a dry or wet area, a safe sealing system must be provided at the place of penetration of the pipeline in the wall of the pipeline structure in order to ensure maximum safety during repair, maintenance and inspection.
There are situations where large relative movement takes place between the structure and the submarine pipeline. Such movements may be caused, for instance, by expansion of the pipeline due to temperature and/or pressure in the pipeline and movement of the structure due to external influences like waves, current, wind and soil deformation.
Large relative movements between the pipeline and the platform structure may thus give rise to high stresses and loads in the pipeline and in equipment and parts of the structure directly in the way of such movements, such as the seal and pipe support systems.
From U.S. Pat. No. 4,009,584 it is known to seal the place of penetration of a pipeline in the wall of a submerged structure, wherein the pipeline by casting is fixed to the wall of the structure at the place of penetration by means of epoxy or the like. The epoxy is said to be sufficiently flexible to absorb minor relative motion between the pipeline and the structure, that is, minor movements or in the order of magnitude of a few centimeters. One can assume, however, that there may occur forces between the pipeline and the structure which are high enough to destroy the epoxy joint. In order to safeguard against catastrophic results of such an occurrence a safety seal can be arranged around the joint, which seal generally has the form of a stuffing box which is meant to prevent the major leakage until the main seal can be repaired. In one of the embodiments shown the safety seal is connected to a bellow-like sleeve in order to give the safety seal a certain ability to move together with the pipeline without the occurrence of sliding motion--and thereby leakage--between these elements. However, the safety seal remains only a temporary emergency solution until the main seal can be repaired. Such a pipeline being rigidly held in or near the wall of the structure will readily be subjected to high loads at this place since it will serve as a fixed point when the pipeline seeks to move as a result of changes in temperature and/or pressure when the pipeline is put into service. These loads give rise to stresses which may be so high that danger of rupture results. Furthermore, such stresses can often lead to accelerated corrosion and cracking.
The object of the present invention is to provide a method and an apparatus of the type mentioned whereby the above-mentioned drawbacks and deficiencies are generally avoided.
SUMMARY OF THE INVENTION
The method according to the invention thus permits the pipeline to move relatively freely at the place of penetration when subjected to temperature and/or pressure changes when being put in service. By letting both the sealing device and the vertical section of the riser pipeline be prestressed corresponding to the movement which is to be expected when the pipeline is put in service, neither the seal or the pipeline will be subjected to deflection stresses of any magnitude in use, and the probability of a failure occurring in the critical area inside the platform structure will thereby be substantially reduced.
Since the sealing device may be built to any desirable length by putting together a sufficient number of seal elements according to the invention, the flexibility of the seal may be adapted to the expected movement of the pipeline at the place of penetration. The seal elements are of a very robust and simple design and are very resistant both to mechanical and chemical influence. Furthermore, the sealing device according to the invention is easy to install and does not invite incorrect assembly. Consequently, it satisfies generally all the requirements which may be imposed on such a sealing device.
For improved understanding of the invention, it will be described in greater detail with reference to the examplifying embodiments shown in the drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically a platform structure resting on the sea bed and being penetrated by a pipeline.
FIG. 2 shows, partly in section, an enlarged view of the place of application of the invention at II of the structure in FIG. 1.
FIG. 3 shows, partially in section, a sealing device according to the invention during installation.
FIGS. 4-7 show sections through seal elements according to the invention in various load situations.
FIG. 8 shows partially in section a sealing device according to the invention after installation, but before the pipeline is commissioned.
FIG. 9 shows the sealing device in FIG. 8 after commissioning of the pipeline.
FIG. 10 shows an alternative application in a platform having a supporting structure of steel.
FIG. 10a shows an enlarged view of the penetration point in the platform leg of the pipeline.
FIG. 11 shows an alternative examplifying embodiment of the invention, partially in section, used in close quarters.
FIGS. 12 and 13 show axial sections of some of the components of the sealing device in FIG. 11.
FIG. 14 shows the parts in FIGS. 12 and 13 installed together with a further component of the sealing device.
FIGS. 15 and 16 show the sealing device in FIG. 14, partially in section, during two phases of installation of a pipeline.
FIG. 17 shows the sealing device in FIGS. 15 and 16 following completed pipeline installation.
FIG. 18 shows a further sealing device according to the invention applied for a pipeline having substantially smaller dimension than the maximum possible.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The structure 5 shown in FIGS. 1 and 2 is partially submerged in water 2. The deck 15 of the structure 5 is situated in the atmosphere 4 above the water surface 3. The base 13 of the structure rests on the sea bed. The water depth 8 may vary; however, the present invention may be used at water depths of 150 m or more.
As shown in FIG. 2, a submarine pipeline 6 is connected to the riser pipe 7 at point 19. The riser 7 penetrates the wall 12 of a passage 113 in the base 13 of the structure 5 through a penetration sleeve 11. A seal 10 keeps water 2 out of the areas 20 and 22 inside the structure 5, so that inspection and repair work may be performed as indicated in FIG. 2 by means of a worker 21.
The riser 7 extends generally horizontally from the connection point 19 outside the structure 5 to the area 20 inside a column 14 of the structure. Here the riser extends generally vertically with a section 16 up through the column 14 to the deck 15 of the structure. The seal 10 permits the riser 7 to move in the direction of the arrows 17 and 18 while maintaining the sealing action.
FIG. 3 shows the seal 10 in greater detail. The seal consists of a plurality of individual seal elements 23 which are bolted together by means of flanges 24 into a row which forms the complete sealing device. One end 25 of the sealing device 10 is bolted to the penetration sleeve 11, while the other end 26 is bolted to a flange 27 which is welded to the riser pipe 7 to effect a permanent seal.
Each seal element 23 consists, as is apparent from FIG. 4, of an inner cylinder 28 and two outer cylinders 29 of larger diameter and each overlapping an end of the inner cylinder 28, and two rings 31 of elastomer material which is placed in between each of the overlapping parts 30 of the cylinders. The elastomer rings 31 are bonded to the walls of the cylinders 28 and 29. The two elastomer rings 31 in each seal element 23 can allow relative movement between the cylinders, as suggested in FIGS. 5, 6 and 7. FIG. 6 shows the inner cylinder 28 and the outer cylinder 29 is unstressed condition without any displacement therebetween. FIG. 5 shows the outer cylinders 29 displaced away from each other, while FIG. 7 shows the outer cylinders 29 displaced towards each other.
The total relative displacement between the ends 25 and 26 of the sealing device 10 can be given any desirable magnitude by simply adjusting the number of individual seal elements 23 to be bolted together.
The thick elastomer rings 31 connecting the inner cylinder and the outer cylinders 29 will not easily be subjected to mechanical damage, and they will therefore be able to resist quite a high differential pressure. Thus, the sealing device 10 will give a high degree of safety during its entire lifetime.
The elastomer rings 31 may be made of synthetic rubber having a hardness of 65 Shore A.
When the pipeline is in operation, the pressure and/or temperature of the fluid conveyed in the submarine pipeline 6 and the riser 7, 16 during normal circumstances give a substantially permanent displacement of the riser 7, 16 and the seal 10 of magnitude 32 in the direction of the arrow 18 in FIGS. 2 and 9. In order to eliminate sustained stresses in the elastomer rings 31 and the riser 7, 16 due to this displacement 18, the riser and the seal 10 is displaced or prestressed an equivalent distance 32 in the opposite direction 17 before the pipeline sections are welded together.
This may be achieved, e.g., by means of a number of rods 33 attached between the wall 12 and a point 35 on the riser 7. By tightening turnbuckles 34 in the rods 33 the riser will be displaced a corresponding distance 32 in the direction of the arrow 17, and concurrently the elastomer rings 31 will be compressed or prestressed the same amount, as indicated in FIG. 8.
When the pipeline sections have been completely connected to each other and the pipeline has been activated, i.e., a fluid is flowing through the pipeline system 6, 7, 16, the rods 33 are removed so that the riser 7 and the seal 10 are allowed to move in the direction 18 a distance 32, as indicated in FIG. 9. This brings the elastomer rings 31 back to their undeformed condition, and concurrently the bending stresses originating in the vertical riser section 16 during prestressing of the seal, are reduced. The length of the horizontal section 7 of the riser between the seal 10 and the vertical section 16 is small enough that thermal expansion of this section 7 will have insignificant effect on the stresses in the vertical section 16. According to the invention both the seal 10 and the riser 7, 16 during normal operating conditions are subjected to the lowest possible loads. This is of major importance for the safety and useful life of the installation.
The individual seal elements 23 may on one or more sides be equipped with a coating for protection against corrosion and/or for giving electrical isolation. Thus, the elements shown in FIGS. 3 and 4 are equipped with a rubber coating on the side facing inwards towards the pipeline.
FIG. 10 shows a sealing device 110 in accordance with the invention applied on a riser pipe 7 which extends into a leg 36 of a steel supporting structure for a platform 37.
FIG. 11 shows a riser pipe, the horizontal section 7 of which extends through the wall 36 of a hollow column of a steel structure. This riser pipe continues in a vertical section 16 inside the column. At the place of penetration a penetration sleeve 11 is welded to the wall 36 of the column. Between the penetration sleeve 11 and the riser pipe 7 is installed a sealing device according to the invention, here in a form requiring little space inside the column.
The design of this sealing device will be apparent from FIGS. 12-14. FIG. 12 shows a flexible body consisting of two seal elements 23 which are bolted together at adjacent flanges 24. The flexible body is placed on to a cylinder 38 which at one end is equipped with a flange 39. The flange 39 is bolted together with the adjacent flange 24 of the flexible body. Thereafter the outer cylinder 40 is placed on to the flexible body and attached rigidly and tightly at one end to the flange 39, for instance by welding. The other end of the outer cylinder 40 is equipped with a flange 41. The flanges 24 of the flexible body are equipped with holes 42 in addition to the bolt holes, and in the ones of these flanges which are attached to the flange 39, these holes have a somewhat smaller diameter and are internally threaded for attachement of prestressing bolts 43 introduced through the larger holes in the other flanges 24. The prestressing bolts 43 are also equipped with threads at their opposite, free ends, and nuts 44 are screwed onto these ends. By tightening these nuts the flexible body will be compressed, as is apparent from FIG. 14. This figure further shows that the inner cylinder 38, the flange 39 and the outer cylinder 40 together form a protective housing 45 for the flexible body.
In FIG. 15 the housing 45 is shown, together with the flexible body in compressed condition, installed in a penetration sleeve 11. The flange 41 of the housing is attached to an inner flange 46 on the penetration sleeve via a distance piece 47. The length of the distance piece 47 is adapted to the length of the housing 45 so that its annular bottom plate 39 is located adjacent to a generally funnel-shaped guide 48 arranged at the outside end of the penetration sleeve 11. The guide is preferably formed so that the inner wall 38 of the housing forms an extension thereof without stepwise transitions.
FIG. 15 also shows the end of a pipe 7 in the process of being pulled through the penetration sleeve 11 and the sealing device. The pipe end is equipped with a fixed ring 49, against which is resting a loose ring 50. An elastic steel 51 is attached to the loose ring. During pulling in of the pipe end the seal 51 will be brought into contact with a rest 52 fixed to the inwardly facing surface on the flexible body. A temporary seal will hereby be formed, permitting water to be pumped out from the inside of the column in order for the sealing device according to the invention to be attached permanently to the pipe. This is done by attaching a connecting piece 53 between the flexible body and the pipe, for instance by welding. As shown in FIG. 18, the connecting piece 153 may preferably have a conical portion in order to reduce bending stresses. After the connecting piece has been installed, the prestressing bolts 43 (FIG. 16) are removed, and the flexible body may now follow movements of the riser pipe 7 with respect to the column wall 36.
FIGS. 17, and 18 show the condition of the flexible body when the riser pipe 7 has moved inwards the expected amount, for instance due to thermal expansion.
The sealing device according to the invention may easily be adapted to pipelines having smaller diameter than the largest pipelines which during the design stage have to be expected and therefore will be decisive for the diameter of the penetration sleeve 11. At this point it will often not be possible to know the exact number and dimension of the pipelines that will have to be connected to the structure when it has been placed on the sea floor. It is therefore necessary to provide sufficiently many penetration sleeves with sufficiently large diameter in order to be able to cover the actual situation at a later stage. Should it become desirable to install a pipeline having substantially smaller diameter than expected, the penetration sleeve may easily be adapted to the new pipe dimension by means of the sealing device according to the invention. An example of such adaptation is shown in FIG. 18. The distance piece 47 is here given a smaller internal diameter than the sleeve 11 so that a housing 45 for the flexible body adapted to the particular pipe dimension easily may be attached. Furthermore, the funnel-shaped guide 48 is equipped with an extension piece 54 which is formed so as to avoid a step transition between the guide and the inner wall of the housing. This is of importance for avoiding problems during pulling in of the pipe and for avoiding unnecessary damage to the seal 51. In order to further reduce the risk of such damage, the seal 51 may alternatively be fixed to the rest 152 instead of sitting on the pipe 7. In FIG. 18 the rest 152 is shown to be arranged on the lower cylinder 28 of the element 23. This positioning will usually be entirely satisfactory, especially by smaller pipe dimensions. By larger pipe dimensions, and especially when there is danger that the pipes may be pulled in somewhat misaligned with the axis of the penetration sleeve, it will usually be advantageous to arrange the rest 152 and possibly the seal 51 on the outer cylinder 29. Thus, the prestressing bolts 43 may be used to adjust the seating of the seal against the ring on the pipe and this way stop any leakage due to insufficient alignment between these cooperating parts.
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An axially flexible sealing device connecting two pipeline ends which comprises a number of sealingly connected annular members, each annular member including an inner cylindrical member, two spaced apart outer cylindrical members, and separate flexible ring members connecting the outer cylindrical members to the inner cylindrical member, each outer cylindrical member having a portion extending axially beyond the adjacent end of the inner cylindrical member when the attached flexible ring member is in an untensioned state. The sealing device is designed for use in connecting two pipelines located beneath sea level wherein the end of one of the pipelines is located in a hollow structure and one of the sealing devices is connected thereto, whereas the other end of the sealing device is sealingly connected to one end of a penetration sleeve which is sealingly connected through the wall of the structure (the other end of the sleeve being connected to the end of the other pipeline).
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This is a division of application Ser. No. 307,124, filed Nov. 6, 1972, now U.S. Pat. No. 3,888,519.
DESCRIPTION OF THE PRIOR ART
The present invention relates generally to fittings for coupling lined tubing, without permitting the fluid, passing through the tubing, to come into contact with the outer jacket of the tubing.
Lined pipe has been used successfully in a variety of applications where it is necessary that the pipe not contaminate or react with the fluid passing through the tubing. Typically this lining material is expensive and its structural properties are such that is is desirable to have a surrounding jacket of a stronger and less-expensive metal.
Tin lined copper pipe has been used successfully in pure water systems, since the tin does not contaminate or react with the distilled water. The copper jacket provides the necessary structural support for the substantially weaker tin, and together they provide a pipe that is substantially less expensive than a pipe made completely of tin. However in such pure water systems, it is necessary that the distilled water not come in contact with the copper jacket. For this reason a problem exists whenever one desires to connect one tin lined copper pipe with another. Obviously if one cuts one of these pipes, in order to connect it with another, as one normally does when connecting piping, the outer copper jacket would be exposed to the distilled water.
A common method, which has been used to join tin lined copper pipes, has been to thread the exterior copper jacket and then, by means of a threaded coupling, tightly butt the pipes together. Obviously this installation method requires precise alignment and close tolerancing, in order to prevent any possible water contamination. Furthermore, since threads must be cut into the pipe's outer jacket, it must be of a thickness considerably greater than is required for structural reasons alone. Therefore tin lined pipe systems are considerably more expensive, in terms of material and installation costs, than corresponding tin lined tubing systems would be, if practical.
Prior art devices for connecting tin lined copper tubing have also used the abutment technique and require complex threaded coupling systems, which are accurately toleranced and expensive, have proven difficult to install, and which cannot be relied upon to prevent the pure water from coming into contact with the outer copper jacket.
It is therefore desirable to provide a fitting, for coupling lined tubing that is simple and easy to install, can be used with any size copper tubing, eliminates the necessity for using of tin lined copper pipe, and will not permit the fluid, passing through the tube, to come into contact with the outer jacket.
A SUMMARY OF THE INVENTION
A cylindrical segment of the jacketing material is removed from the end of the lined tubing, to be connected to a similarly lined coupling. An O-ring formed of a flexible, compressible material, which will not contaminate or react with the fluid passing through the tubing is slipped over the completely exposed inner lining, until it abuts the end of the outer metal jacket. The inner lining is then slightly flared and the tubing is now inserted into a female receptacle of the lined coupling. The tubing is inserted until a cylindrical segment of the remaining outer jacket of the lined tubing is enclosed by the female receptacle and the O-ring has formed a fluid tight seal between the receptacle and the exterior surface of the exposed inner lining. The enclosed outer portion of the lined tubing is clamped to the receptacle, providing a direct load path through the outer metal jacket of the lined tubing and the lined coupling. This arrangement does not require threaded joints, it can be used for any sized tubing and is simple and easy to install. In view of its superiority over prior art methods, this arrangement makes practical the use of tin lined tubing, of any size, in pure water systems, thereby providing a system that is cheaper and lighter than previous tin lined copper systems and which will not contaminate or react with the distilled water passing through it.
BRIEF DESCRIPTION OF THE DRAWING
The several features and advantages of this lined tubing fitting arrangement, constructed in accordance with the invention, will be more readily understood and appreciated from the following detailed description of the preferred embodiments, herein selected for purposes of illustration, as shown in the accompanying drawing in which:
FIG. 1 is a perspective view of a coupling for lined tubing and a lined tubing, constructed in accordance with the invention;
FIG. 2 is a front elevational view, partly in section, of a lined tubing fitting, constructed in accordance with the invention;
FIG. 3 is a side elevational view, partly in section, of a clamping device suitable for use in a lined tubing fitting constructed in accordance with the invention; and
FIG. 4 is a front elevational view, in section, of a lined pipe fitting, constructed in accordance with the invention.
DESCRIPTION OF PREFERRED EMBODIMENT
As shown in FIG. 1 a lined tubing 2 has an outer supporting jacket 4 for an inner lining 6. Tubing 4 and lining 6 are constructed of dissimilar materials and are concentric tubes fit together by means well-known in the art. A cylindrical segment of tube 4 has been removed, by a standard pipe cutter for example, to expose completely lining 6, allowing it to protrude from end 7 as indicated at 10. An elastic and compressible O-ring 8 has been slipped over the protruding portion 10 until it abuts end 7 of outer-tubing 4. The protruding portion 10 has been slightly flared, to hold the O-ring in place. Also shown in FIG. 1 is a lined coupling 12 having a female receptacle 14 for receiving tubing 2. A lubricant, soluble in the fluid which will pass through tubing 2, may be applied to permit easier insertion of the end of tubing 2 into receptacle 14.
Referring to FIG. 2, tubing 2 had been completely inserted into lined coupling 12. Coupling 12 has an exterior jacket 18 which, for purposes for this preferred embodiment, will be assumed to be of the same material as outer-tubing 4 of tubing 2, and has an interior lining of material 16 which, for purposes of this preferred embodiment, will be assumed to be the same material as inner lining 6 of tubing 2. For pure water systems, it is preferrable that materials forming linings 6 and 16 be of pure tin while, for strength and cost reasons, materials forming jackets 4 and 18 are preferably copper.
Tubing 2 has been inserted until a cylindrical segment of outer-tubing 4 is partially within receptacle 14 and O-ring 8 has been compressed to form a fluid tight seal between lining 16 of the receptacle and the outer surface of inner lining 6. As noted above, the protruding portion of inner lining 6 is flared as indicated at 10. The outer most portion of the flared portion 10 should be of equivalent dimensions with the outer surface of tubing 2. For purposes of this embodiment, end 10, of lining 6, has come to rest at shoulder 20 of lining 16 within coupling 12.
O-ring 8 is composed of an elastic and compressible material which will not react with or contaminate the fluid passing through tubing 2, and is of such a thickness that, with tubing 2 fully inserted, O-ring 8 has been tightly compressed against end 7 of outer-tubing 4, lining 16 of receptacle 14 and the outer surface of the inner lining 6. The fluid pressure against O-ring 8, further compresses it against end 7 of outertubing 4, thereby providing an even tighter seal. In this manner, the fitting of this invention prevents any fluid, passing through tubing 2, from leaking from coupling 12 or coming into contact with either outer-tubing 4 of jacket 18 of coupling 12. Therefore it can be seen that fluid passing through tubing 2 and coupling 12 will only come into contact with non-contaminating, non-reactive surfaces.
Receptacle 14 is shown with jacket 18 extending beyond lining 16 and coming into direct contact with the outer-tubing 4 of tubing 2. With the outer-tubing 4 directly attached to jacket 18, any loading imposed on the coupling will be transmitted through the structurally stronger jacketing materials. For purposes of this preferred embodiment, a clamping device 24 is shown for attaching tubing 2 to coupling 12.
Referring to FIG. 3, an outer ring 24 is shown placed concentrically about receptacle 14 beyond lining 16, with symmetrically arranged and radially directed, threaded holes 28 extending through it. Receptacle 14 has holes 22 which are concentrically aligned with holes 28 in ring 24. Set screws 26 threadedly engage holes 28 and pass through holes 22, until they come to bear against outer-tubing 4 of tubing 2. These screws also press against the sides of holes 22 in jacket 18 and thereby provide a direct load path between jacket 18 of coupling 12 and outer-tubing 4 of tubing 2. This arrangement insures that all loads, imposed on the coupling, will be transmitted through the structurally stronger jacketing materials. Obviously coupling 12 could be a cast fitting, or be constructed so that jacket 18 is thick enough to receive set screws 28. In this latter modification holes 22 would of course be threaded and clamping device 24 would not be needed. Other means, such as belt clamps or strong adhesives should also prove satisfactory as an attachment mechanism between tubing 2 and coupling 12.
While our invention is especially attractive to users of lined tubings, it is also suitable for coupling any type of lined conduits. For example, referring to FIG. 4, coupling 12 could be cast, with jacket 18 considerably thicker. Outer-tubing 4 could be a pipe. Pipe 4 and jacket 18 would be threaded with matching threads as shown respectively at 30 and 32. In this arrangement no clamping device would prove necessary and since O-ring 8 still provides a seal between lining 16 and the exposed portion of lining 6, this arrangement would provide a non-contaminative coupling for lined pipes that does not require precise tolerancing.
Our invention is particularly suitable for tin lined copper tubing, where outer-tubing 4 and jacket 18 are formed from copper and linings 6 and 16 are formed from tin. Thus it can be seen that it is no longer necessary to employ tin lined copper piping in order to obtain a satisfactory joint. Fittings constructed in accordance with our invention are simple to install using standard tools, yet provide leak-proof and contamination-free couplings. Therefore our invention makes practical the use of lined copper tubing, of any size, in pure water systems, thereby greatly reducing the weight and expense of such systems.
It should be understood, of course, that the foregoing disclosures relate only to the preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen, within the purposes of the disclosures, which do not constitute departures from the spirit and scope of the invention.
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A leak-tight non-contaminative joint, for connecting tin lined copper tubing with a tin lined coupling member, is formed by exposing the tin lining at the tube end and inserting an elastic "O"-ring between the exposed lining and the surrounding coupling, so that the fluid within the tubing and coupling does not contact any metal other than tin. A clamp for holding the coupling member and tubing together is also disclosed.
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BACKGROUND OF THE INVENTION
The present invention relates to methods for treating unstable atherosclerotic lesions using cytotoxic, nonablative ultraviolet radiation.
Atherosclerosis is a disease which causes thickening and hardening of the arteries. It is characterized by lesions of raised fibrous plaque formed within the arterial lumen. Atherosclerotic plaque is commonly treated by means of angioplasty through the use of a balloon catheter. Balloon angioplasty involves passing a small, balloon-tipped catheter percutaneously into an artery and up to the region of obstruction. The balloon is then inflated to dilate the area of obstruction. Other devices, such as atherectomy instruments, which remove obstructions by peeling or shaving plaque from the artery wall, can also be utilized in the treatment of atherosclerosis.
More recently, laser systems have been proposed for performing angioplasty. In laser angioplasty, a catheter carrying a fiber optic waveguide is passed through a blood vessel, positioned near an obstruction, and then activated to decompose the plaque with laser radiation.
Unfortunately, restenosis, or closure of the blood vessel following angioplasty, is a common-occurrence following all types of such surgery. Angioplasty and atherectomy procedures to open a stenosis or closed blood vessel are highly invasive procedures which induces injury to the arterial wall. Such operations often cause medial smooth muscle cells of the arterial wall to proliferate in response to this injury. This proliferation is believed to contribute, at least in part, to restenosis.
It is known from U.S. Pat. No. 5,053,033 that such restenosis following angioplasty can be inhibited by irradiating the angioplasty site with ultraviolet radiation to kill a portion of the smooth muscle cells. In particular, U.S. Pat. No. 5,053,033 discloses that ultraviolet radiation, preferably at a wavelength ranging from about 240 nanometers to about 280 nanometers can have cytotoxic effects and kill a large percentage of the smooth muscle cells after angioplasty but before proliferation occurs.
While angioplasty followed by ultraviolet radiation to inhibit restenosis may be one method to treat occluded blood vessels, many atherosclerotic lesions do not warrant invasive treatment by angioplasty or atherectomy. For example, many lesions are characterized by a raised fibrous plaque which is not yet substantially obstructing a blood vessel. Such a condition may not necessitate angioplasty to physically open the obstruction, but the lesion still has the potential to thicken further and eventually cause a more severe obstruction, vasospasms, or the cup of the fibrous plaque may rupture, leading to thrombosis of the vessel. These lesions may be associated with reduced medial smooth muscle cell layers of the blood vessel wall and certain biochemical changes in the intima or inner surface of the blood vessel which cause platelet attraction and blood coagulation over time.
There exists a need for a method of stabilizing such lesions or preventing further plaque development without risking injury to the arterial wall by invasive angioplasty. Accordingly, it is an object of the present invention to provide a method of stabilizing atherosclerotic lesions without physically altering the lesion site.
SUMMARY OF THE INVENTION
Atherosclerotic lesions can be treated and stabilized without mechanically assaulting or otherwise physically reshaping the lesion by irradiating the lesion with cytotoxic, nonablative ultraviolet (UV) radiation. Such radiation, preferably ranging from about 240 nanometers to about 280 nanometers, kills or inactivates smooth muscle cells of the blood vessel wall, thereby reducing the potential for vasospasms. The smooth muscle cells of the plaque are also inactivated and prevented from migrating by this treatment. The UV radiation is preferably delivered via an optical fiber or other waveguide incorporated, for example, into a percutaneous catheter.
Various UV radiation sources can be use in accordance with the present invention to deliver lesion stabilizing therapy without physically reshaping or altering the lesion, including both laser and non-coherent radiation sources. The terms "without physically reshaping" and "without physically altering" are defined herein as encompassing procedures which treat vascular lesions without physically removing atherosclerotic plaque by, for example, using a plaque shaving device or ablative radiation, or by mechanically opening the lumen, or by applying pressure to dilate the area of obstruction using a balloon catheter or the like. Either pulsed or continuous wave ("CW") lasers can be used in the present invention, and the lasant medium can be gaseous, liquid or solid state. One preferred laser source is a pulsed excimer laser, such as a KrF laser. Alternatively, rare earth-doped solid state lasers, ruby lasers and Nd:YAG lasers can be operated in conjunction with frequency modification means to produce an output beam at the appropriate UV wavelength. In another alternative, a UV flash lamp can be employed.
The UV radiation source preferably produces an output beam having a wavelength less than about 280 nanometers. The therapeutic UV radiation useful in the present invention will typically range from about 280 nanometers down to about 240 nanometers (due to the limited transmission efficiency of glass fibers at lower wavelengths). In one preferred embodiment, a laser system is disclosed which operates at about 266 nanometers to maximize the cytotoxic effect of the radiation. Other useful UV radiation sources include, for example, Argon ion lasers emitting UV light at about 257 or 275 nanometers and KrF excimer lasers emitting light at about 248 nanometers.
The invention can be practiced with a low energy radiation source. The term "low energy" is used herein to describe both laser and non-coherent radiation systems having an energy output of less than about 5 J/cm 2 per pulse for pulsed lasers, or a total dose of less than about 1000 J/cm 2 , more preferably less than 100 J/cm 2 , for continuous wave lasers or non-coherent radiation sources.
In one illustrated embodiment of the invention, at least one optical fiber for transmission of UV radiation is incorporated into a conventional percutaneous catheter and operated to deliver therapeutical UV radiation to the lesion site. In this embodiment, the therapeutic radiation can be provided by a single laser or a plurality of lasers operating in tandem to deliver cytotoxic, nonablative laser radiation.
In another aspect of the invention, novel UV radiation sources are disclosed herein. In one illustrated embodiment, a laser having an output beam wavelength of about 1064 nanometers, such as a common Nd:YAG laser, can be used in conjunction with two doubling crystals to yield a radiation output of about 266 nanometers. Similarly, a Nd:YLF laser operating at about 1047 nanometers can be used in conjunction with two frequency doubling crystals.
Novel catheter systems are also disclosed herein. Such catheter systems are useful in the performance of laser angioplasty and are preferably equipped with at least one optical waveguide for delivery of the UV radiation therapy, which can be, for example, an optical fiber having about a 200 micron diameter core. The catheter tip can also contain focusing optics or diffusive elements for use in directing the radiation emitted from the catheter within an artery.
The invention will next be described in connection with certain illustrated embodiments. However, it should be clear that various changes and modifications can be made by those skilled in the art without departing from the spirit or scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of a laser therapy catheter for stabilizing atherosclerotic lesions without physically reshaping the lesion site;
FIG. 2 is a view of the distal end of the catheter of FIG. 1;
FIGS. 3A-3B are schematic cross-sectional illustrations of a system incorporating the catheter of FIG. 1;
FIG. 4 is a schematic perspective view of an alternative catheter for delivering nonablative, cytotoxic UV radiation to the site of an unstable lesion;
FIG. 5 is a view of the distal end of the catheter of FIG. 4;
FIG. 6 is a schematic illustration of a laser device useful in the present invention.
DETAILED DESCRIPTION
In FIG. 1, a laser therapy catheter 10 is shown, including a guide wire 14. Also disposed within the catheter are a plurality of optical fibers 54 for delivery of ultraviolet radiation. The catheter can also include a radio-opaque tip 50. In FIG. 2, the distal end 12 of the catheter of FIG. 1 is shown in more detail, including an exemplary disposition of six optical fibers 54 about a central guide wire 14. Alternatively, the distal end of the catheter can include an optically diffusive tip, as known in the art, which serves to diffuse the UV radiation from one or more optical fibers into a circumferential or partially circumferential pattern.
The use of the catheter system 10 is schematically illustrated in FIGS. 3A-3B. In use, the guide wire 14 is first introduced into the obstructed blood vessel and used to guide the catheter 10 into position adjacent to the plaque or lesion (e.g., under radiographic control). As shown in FIG. 3A, the distal tip of the catheter is then positioned to deliver UV radiation therapy to the lesion 32. A therapeutical laser 28 can then be activated to deliver UV radiation 30 which will kill a major portion of the smooth muscle cells 40 within the media 24 of the blood vessel wall without physically reshaping the lesion and without damaging either the inner endothelium layer 22 or the outer adventitia 26 of the blood vessel. The energy of the UV radiation can be about 5 J/cm 2 per pulse or less for pulsed lasers, or a total dose of about 1000 J/cm 2 or less. The power density of the radiation is preferably less than 5 watts per square centimeter, more preferably less than 2 watts per square centimeter.
As shown in FIG. 3B, by killing or inactivating a major portion of the smooth muscle cells in the vicinity of the lesion, the end result of the treatment is substantially fewer, if any, smooth muscle cells remaining in the lesion site to proliferate or migrate and cause lesion instability. Thus, the capability of the blood vessel wall to constrict or produce vasospasms is substantially limited or completely removed.
In FIGS. 4 and 5, an alternative catheter configuration 10A for delivering therapeutic, nonablative UV radiation to the site of an unstable atherosclerotic lesion is shown, including a guide wire 14 and two laser radiation delivery systems 76 and 78. The laser delivery systems 76 provide therapeutic UV radiation to inactivate smooth muscle cells in the vicinity of the lesion, thereby stabilizing the lesion. Like the system of FIG. 1, the catheter of FIG. 4 can also include a radio-opaque tip 50 to aid in positioning the catheter within a blood vessel under radiographic control. The second laser delivery system 78 can provide illumination and viewing fibers or a second source of therapeutic (or even ablative) radiation (e.g., at a different wavelength or energy fluence).
As shown in more detail in FIG. 5, the distal end of 12A of the catheter can include two therapeutic UV radiation delivery systems 76 and 78. Multiple optical fibers 54 for UV radiation therapy are encased in sleeve 66 which is positioned on one side of the guide wire 14 to provide the UV therapy system. A similar sleeve 67 encasing the second set of optical fibers 68 forms the second radiation therapy subsystem 78 disposed on the opposite side of the guide wire 14. The catheter can further include a flushing port 72 for the introduction of saline at the site and/or a suction port 74 for clearing the site of fluids during laser operations.
The catheter system 10A operates essentially in the same manner as system 10 described in FIGS. 3A and 3B.
As noted above, the therapeutic UV radiation can be provided by a variety of sources, including non-coherent UV light sources and excimer laser sources (e.g., an Argon ion laser operating at about 275 nanometers or a KrF excimer laser operating at 248 nanometers). In FIG. 6, an alternative laser device 70 is shown which can be used in the present invention to provide the therapeutic UV radiation. In the system 70, an output beam from a laser source 48, such as Nd:YAG laser with an output radiation having a wavelength of about 1064 nanometers is introduced via coupler 56 into an optical fiber 54 which is preferably a rare earth-doped silica fiber (e.g. a Neodymium-doped optical fiber). As the radiation from laser source 48 is introduced into the optical fiber 54, the fiber is also optically pumped by an optical pump source 52 (e.g., a laser diode having an output radiation wavelength of about 808 nanometers, likewise coupled to the fiber 54 by coupler 56). The doped optical fiber thus acts a laser amplifier.
At the distal end of fiber 54, the system is terminated in two frequency-multiplying crystals 60 and 62. The first crystal 60 is a frequency-doubling optical element, such as a potassium dihydrogen phosphate (KDP) crystal, and the second crystal 62 is also a frequency-doubling optical clement, such as a barium boron oxide (BBO) crystal. Focusing optics 64, such as a grated refractive index ("GRIN") lens, can be included at the output end of the optical fiber 54. With the system as described, therapeutic laser radiation of a wavelength of about 266 nanometers is produced.
The therapeutic radiation useful in stabilizing lesions in accordance with the present invention is preferably delivered at an energy level below the threshold for ablation. This ablation threshold will vary depending on the wavelength of the radiation. Table 1, below, provides guidance with reference to a number of commonly used UV emission bands. As can be seen from Table 1, the therapeutic dose of radiation for stabilizing vascular lesions using a pulsed radiation source will typically employ radiation at less than about 5 J/cm 2 per pulse, preferably less than 2 J/cm 2 per pulse and, in many applications, less than 1 J/cm 2 per pulse. The present invention is thus intended to operate well below the ablation threshold.
TABLE 1______________________________________WAVELENGTH ENERGY FLUENCE______________________________________350 nm 4.2 J/cm.sup.2308 nm 1.4 J/cm.sup.2266 nm 1.0 J/cm.sup.2248 nm .35 J/cm.sup.2222 nm .22 J/cm.sup.2193 nm .13 J/cm.sup.2______________________________________
Whether radiation is pulsed or continuous wave, it is important to minimize the total dose delivered to the target vascular region. For a typical treatment protocol, the total dose will usually be less than 1000 J/cm 2 , preferably less than 100 J/cm 2 , and more preferably less than 20 J/cm 2 , regardless of the nature of the radiation (i.e., pulsed or continuous wave).
The present invention can also be practiced in conjunction with the systemic administration of therapeutic agents that enhance the effects of site irradiation. For example, a chromophore, such as psoralen, can be administered prior to irradiation of the lesion site. The psoralen will be absorbed by the smooth muscle cells, thus rendering them more susceptible to the UV light.
Those skilled in the art will be able to recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific compositions and procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the following claims.
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Ultraviolet radiation can be used to treat vascular diseases. In particular, for unstable lesions where angioplasty may not be warranted, cytotoxic, nonablative ultraviolet radiation, preferably at a wavelength in the range of about 240 to about 280 nanometers, can be used to disable the intima and reduce spasms associated with partially occluded blood vessels.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of U.S. patent application Ser. No. 10/330,573 filed Dec. 26, 2002 in the name of the Applicants, to which priority is claimed.
FIELD OF THE INVENTION
This invention relates generally to online dating support systems and methods and, more particularly, to a secure online dating support system and method in which relevant personal information about participants is obtained, verified and provided to other participants.
BACKGROUND OF THE INVENTION
The online (or Internet) dating service industry has grown significantly in recent years. ComScore Media Medtrix has provided recent user information for a number of the larger personals/dating web-sites (there are over 200 on-line dating sites), as follows:
Number of Unique Users (as of Web-site July 2002) Match.com 5,665,000 Yahoo! Personals 4,412,000 Date.com 2,295,000 Matchmaker.com 1,522,000 Someonelikesyou.com 1,237,000 Dreammates.com 983,000
In addition, a recent Jupiter Research study stated that more than 34 million people have visited online personal ad sites, and that the average user spends 13 hours a month on such sites.
Despite its growth, the online dating/personals industry continues to be plagued by the problem of users either misrepresenting themselves (e.g., as younger, more attractive (via outdated pictures or through misrepresentation of height/weight), more successful, etc.), or concealing important information (e.g., a criminal record, a drug or alcohol addiction, sexually transmitted diseases, a marriage, etc.). As of Dec. 11, 2002, there have been over 17,900 online dating horror stories, and some have ended tragically.
Accordingly, a need exists for a support system and method for online dating that provides participants with the security of knowing that participants are representing themselves accurately, and further that potentially harmful information is fully disclosed. The system and method needs to provide a convenient vehicle for persons to submit information and to provide the online dating support service with the needed permission and information to conduct a further background examination. The present invention satisfies these needs and provides other, related advantages.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an online dating support system and method that provides for the voluntary verification of relevant personal information concerning participants.
It is a further object of the present invention to provide an online dating support system and method that provides for the conduct of a voluntary background check of participants.
It is a still further object of the present invention to provide an online dating support system and method in which verified personal and background information concerning one participant may be disclosed to other participants.
It is a yet further object of the present invention to provide more than one level of participant verification, with the extent of verification and/or the frequency of re-verification varying from level to level.
It is a yet further object of the present invention to provide a method of personal information verification for dating that provides for the verification of relevant personal information concerning participants.
Other objects, features and advantages of the present invention will become apparent from a consideration of the following detailed description.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with one embodiment of the present invention, an online dating support system is disclosed. The system comprises, in combination: an online dating service; at least one potential member in communication with the online dating service; at least one member in communication with the online dating service; a personal information and authorization receiving center in communication with the online dating service; and an investigator in communication with the online dating service.
In accordance with another embodiment of the present invention, a method of online dating is disclosed. The method comprises the steps of: providing an online dating service; providing at least one potential member of the online dating service; providing at least one member of the online dating service; providing a personal information and authorization receiving center in communication with the online dating service; providing an investigator in communication with the online dating service; the at least one potential member visiting the personal information and authorization receiving center; the at least one potential member providing personal information to the information and authorization receiving center; the information and authorization receiving center communicating the personal information to the online dating service; the online dating service accepting the potential member as a member; and the online dating service posting at least some of the personal information concerning the potential member on a web-site.
In accordance with still another embodiment of the present invention a method of online dating is disclosed. The method comprises the steps of: providing an online dating service; providing at least one potential member of the online dating service; providing at least one member of the online dating service; providing a personal information and authorization receiving center in communication with the online dating service; providing an investigator in communication with the online dating service; the at least one potential member visiting the personal information and authorization receiving center; the at least one potential member providing personal information to the information and authorization receiving center, the personal information includes at least one of the following: a photograph of the potential member, wherein the photograph is taken at the information and authorization receiving center, height and weight information concerning the potential member, wherein the height and weight information is obtained at the information and authorization receiving center, birth certificate, information concerning marital status, income information, sexually transmitted disease information, and property ownership information; the potential member providing to the information and receiving center written authorization to obtain additional information concerning the potential member; providing an investigator in communication with the online dating service; the investigator investigating the potential member; providing at least two levels of membership for the online dating service, wherein the at least two levels of membership are differentiated based on an amount of the personal information provided; the information and authorization receiving center communicating the personal information to the online dating service; the online dating service accepting the potential member as a member; and the online dating service posting at least some of the personal information concerning the potential member on a web-site, wherein an accessing member's access to the personal information concerning other of the members is restricted based on the accessing member's membership level.
In accordance with still another embodiment of the present invention a method of personal information verification for dating is disclosed. The method comprises the steps of: providing a personal information and authorization receiving center; a person providing personal information to the information and authorization receiving center, wherein the personal information further includes at least one of the following: a photograph of the person, wherein the photograph is taken at the information and authorization receiving center, height and weight information concerning the person, wherein the height and weight information is obtained at the information and authorization receiving center, birth certificate, information concerning marital status, income information, sexually transmitted disease information, and property ownership information; the personal information and authorization receiving center verifying the personal information; and the personal information and authorization receiving center providing the person with a certification of the personal information.
In accordance with still another embodiment of the present invention a method of personal information verification for dating is disclosed. The method comprises the steps of: providing an online dating service, providing at least one potential member of the online dating service, providing at least one member of the online dating service, providing an information collector in communication with the online dating service, the information collector visiting the at least one potential member, the at least one potential member providing personal information to the information collector, the information collector communicating the personal information to the online dating service, the online dating service accepting the potential member as a member, and the online dating service posting at least some of the personal information concerning the potential member on a web-site.
In accordance with still another embodiment of the present invention a method of personal information verification for dating is disclosed. The method comprises the steps of: providing an online dating service, providing at least one potential member of the online dating service, providing at least one member of the online dating service, taking a photograph of the at least one potential member, the photograph having a date tag, providing the photograph to the online dating service, the online dating service accepting the potential member as a member, and the online dating service posting the photograph on a web-site.
In accordance with still another embodiment of the present invention a method of personal information verification for dating is disclosed. The method comprises the steps of: providing an online dating service, providing at least one potential member of the online dating service, providing at least one member of the online dating service, the at least one potential member obtaining a credit report, the at least one potential member sending the credit report to the online dating service, the online dating service accepting the potential member as a member, and the online dating service posting at least some information from the credit report concerning the potential member on a web-site.
In accordance with still another embodiment of the present invention a method of personal information verification for dating is disclosed. The method comprises the steps of: providing an online dating service, providing at least one potential member of the online dating service, providing at least one member of the online dating service, a person providing personal information to the online dating service, wherein the personal information further includes at least one of the following: at least one photograph of the person, height and weight information concerning the person, birth certificate, information concerning marital status, income information, sexually transmitted disease information, and property ownership information, the online dating service verifying the personal information, the online dating service accepting the potential member as a member, and the online dating service posting at least some of the personal information concerning the potential member on a web-site.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart illustrating an embodiment of an online dating method and support system consistent with the present invention.
FIG. 2 is a block diagram of the basic components of an embodiment of an online dating support system consistent with the present invention, reflecting the interaction therebetween.
FIG. 3 is a flow chart illustrating an embodiment of dating method and support system consistent with the present invention.
FIG. 4 is a flow chart illustrating another embodiment of an online dating method and support system consistent with the present invention and involving an information collector and a screening service.
FIG. 5 is an exemplar of a bronze member report.
FIG. 6 is an exemplar of a silver member report.
FIG. 7 is an exemplar of a gold member report.
FIG. 8 is a flow chart illustrating another embodiment of an online dating method and support system consistent with the present invention whereby a potential member provides an online dating service with a photograph having a date tag.
FIG. 9 is a flow chart illustrating another embodiment of an online dating method and support system consistent with the present invention whereby a potential member provides an online dating service with a credit report.
FIG. 10 is a flow chart illustrating another embodiment of an online dating method and support system consistent with the present invention whereby a potential member provides an online dating with personal information that is first verified by the online dating service before being posted on a website.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 2 , the basic components of an online dating support system 10 consistent with the present invention is shown. The online dating service 12 includes an Internet-based web-site, where members 14 of the service 12 can access information about other members 14 and about the service 12 . Optionally, authorized non-members of the service are permitted to access information about other members 14 . One way in which this could be accomplished could be through the use of access codes. A member 14 could give a non-member (or a member) an access code that allows the non-member (or member) to access a pre-determined amount of personal information about the member 14 . Optionally, each member 14 could be given more than one access code, with each access code allowing a non-member (or member) to access a different amount of personal information about the member 14 . The non-member (or member) could access an amount of personal information about the member 14 through a website of the online dating service, by receiving an email from the online dating service, or by some other means. Also optionally, from that web-site, through a hyperlink or the like, members 14 can communicate with other members 14 .
The service 12 will also comprise an operations component, which is concerned with the intake of new members, the obtaining of personal information concerning potential and existing members, the obtaining of authorization from potential and existing members for background checks, and, generally, the overall operation of the system 10 . The service 12 will interface, electronically and/or otherwise, with each of the other system 10 components. These include, specifically, potential members and members 14 of the service 12 , a personal information and authorization receiving center(s) 16 , and an investigator(s) 18 .
Referring now to FIG. 1 , the operation of the method of the present invention and the functions performed by the various system components will be illustrated by a description of its operation. Initially, a potential member contacts the service 12 . Preferably, that contact is made by accessing the service 12 's web-site, though contact may be made in other forms as well. It should further be noted that contact may be made, initially, by a potential member contacting another dating service web-site, which web-site could provide a hyperlink to the service 12 's web-site. Still further, initial contact may be made at a physical location, such as copy center, a health club or the like. Yet further, initial contact may be made by an information collector who visits a potential member at an agreed upon location (this embodiment is illustrated in FIG. 4 ).
The potential member will then provide the service 12 with some initial personal information. This should include, at a minimum, the potential member's name. It may, optionally, include additional information, such as an address, date of birth, telephone number, photograph, etc. Following receipt of the initial personal information, the service 12 preferably will provide the potential member with an alphanumeric code.
At least at this point, the verification process begins. In one embodiment, the potential member will travel to a personal information and authorization receiving center 16 . This may be an office or the like operated by the service 12 , or a copy center or the like that has arranged with the service 12 to perform information and authorization receiving services. In one embodiment, the center 16 is a copy center, due to the large number of such establishments and their possession of photographic, scanning, copying and computer equipment of a type that greatly facilitates the information and authorization receiving process, and the communication of that information to the service 12 . It should be clearly understood, however, that substantial benefit could be derived from an alternative configuration of the method and support system for online dating in which the personal information and authorization receiving center 16 is at a location other than a copy center, such as a health club.
The potential member will provide the center 16 with the alphanumeric code that the potential member received from the service 12 . The center 16 will then obtain personal information from the potential member. Such information can include any of the following: a fingerprint, a driver's license, the potential member's height and weight, digital (or non-digital) photographs (preferably a head shot and a full body shot), digital (or non-digital) video clip, a year-to-date pay stub, a birth certificate (or other proof of citizenship/lawful residence, such as a visa or green card), college diploma(s), reference letters, mortgage statement, income tax form 1040's for prior year, credit report, resume and/or other employment information, divorce decree, professional association information, and an e-mail address. In the event that multiple membership levels are provided, the extent of personal information obtained may be a function of the level of membership selected by the potential member, with the higher membership levels requiring greater disclosure of personal information.
The documentary information is preferably scanned by the center 16 , so that it may be provided electronically to the service 12 . The potential member's height and weight should be obtained using standard measuring equipment, and recorded by the center 16 for transmission to the service 12 . The fingerprint should be obtained in the ordinary manner and scanned, again for electronic transmission to the service 12 . Once received by the service 12 or a screening service, the personal information of the potential member is verified.
Referring now to FIGS. 8-10 , alternative embodiments of the present invention are shown. The methods of online dating shown in these figures are essentially the same as before, except that the potential member transmits the documentary information or other personal information (by fax, electronically, regular mail, or by some other means) directly to the service 12 (as shown in FIG. 10 ) or to a screening service. In the embodiments shown in FIGS. 8-10 , the method of online dating may comprise only a potential member and the online dating service, with no authorization and receiving center or other individual or entity involved. Referring to FIG. 9 , the potential member obtains his or her own credit report and subsequently provides it to the service 12 . Referring to FIG. 8 , the potential member has a photograph taken having a date tag of some kind. The date tag could be imprinted on the photograph or the date tag could be some other tag capable of verifying the date of the photograph (such as the subject of the photograph holding a newspaper or magazine with the date clearly visible). The potential member then provides the photograph to the service 12 or, alternatively, to a screening service.
In addition to the obtaining of personal information from the potential member, the center 16 will also accept signed authorizations from the potential member for further investigation. Again, the number and type of authorizations obtained may be a function of membership level, if multiple levels are provided. Authorizations could include forms permitting access to Department of Motor Vehicle records, medical records, criminal records, to conduct screening of blood and urine samples, and the like. Additionally, the center 16 could obtain from the member 16 urine and blood samples, for purposes of conducting tests for the presence of drugs, alcohol, or sexually transmitted diseases. (Alternately, a potential member could be referred to a medical practitioner or the like for purposes of providing such samples.)
Information and authorization obtained from the potential member should be communicated to the service 12 . To the extent needed for purposes of conducting further investigation of the potential member, the service 12 will communicate information/authorization to an investigator(s) 18 or a screening service (as shown in the flow chart in FIG. 5 ). The investigator 18 can inquire into a potential member's marital status, criminal background, employment record, educational background, professional licenses, court records, driving record, credit record, and other information potentially relevant to a potential member's suitability as a dating or marriage partner.
It is preferred that the investigator(s) 18 be one or more vendors that operate independently of the service 12 and pursuant to an agreement therewith, though it is possible that some or all of these investigation services could be performed internally by the service 12 or by a screening service. If the investigator(s) 18 is independent of the service 12 , it will communicate the information that it obtains regarding a potential member to the service 12 .
Referring now to FIG. 4 , an alternative embodiment of the method for online dating is shown. The method of online dating shown in FIG. 4 is essentially the same as before, except that in place of an authorization and receiving center, an information collector visits the potential member. Preferably, the information collector will photograph and measure the potential member (preferably height and weight). The information collector may also gather other basic information, such as the person's name and address. The information collector preferably will also collect signed authorizations from the potential member for further investigation. In addition, the information collector preferably will also collect any documentary information in order to transfer this documentary information to a screening service for verification purposes. Optionally, the information collector may take a blood and/or urine sample. Once the information collector has completed collecting information, the information is then communicated either directly to the service 12 or to a screening service for verification. The screening service would then communicate its findings to the service 12 .
When the information gathering process is completed, the service 12 may then communicate to the potential member whether or not he or she has been accepted as a certified member (as opposed to a potential member at the beginning of the process). At one or more of the foregoing steps, payment can be required of the potential member, in the form of an application fee, processing fee, provisional membership fee, monthly membership fees, membership fee, or the like. Preferably, the potential member pays at the beginning of the process, but holds only provisional member status until verification of personal information is achieved. Upon acceptance as a member, it may also be desired to require payment of a periodic subscription fee, such as a monthly fee, for participation in the service 12 .
Once a potential member's membership in the service 12 is finalized, the service 12 should take the necessary steps to make the new member's personal and background information available to other members of the service 12 . Referring to FIGS. 5-7 , this represents one form in which the member information may be displayed, with more information being displayed depending on the level of membership (e.g., bronze, silver and gold).
Preferably, members of the service 12 are required to update their personal and background information on a periodic basis, for example, once a year.
With respect to the possible feature of membership levels, these can be differentiated on one or more bases. Higher (and presumably more expensive) levels can require greater disclose of personal and background information. Alternatively, or in addition, higher levels can require more frequent updating of personal and background information.
By way of example, it may be desired to provide three levels of membership—bronze, silver, and gold—with bronze being the most basic and gold being the highest. A bronze membership may only require confirmation of identity, height and weight, a current photograph(s), and marital status. A silver membership could additionally require home ownership confirmation, provision of a birth certificate, income verification, and a credit report. A gold membership could require the silver and gold information and, in addition, driving and criminal records, substance abuse testing, professional license and association information, etc. (It should be noted that where membership levels are provided, there may be as few as two or more than three.)
Where different levels are provided, it may be desired to limit a member's access to other members at or below his or her level. For example, a gold member could access gold, silver or bronze members, while a silver member could only access silver or bronze members. Alternatively, a one-time fee could be charged for accessing members at higher levels. Alternatively, each member could access at least bronze level personal information from any other member, but additional personal information will only be available to those of an equal or greater level of membership.
The service 12 will preferably perform other functions, in addition to those described above. For example, it can facilitate the filing by e-mail or otherwise complaints by one member against another. It can, relatedly, create records of such complaints, so that they may be reviewed by members. The service 12 can facilitate a member's response to complaints against him or her, and possibly the resolution of complaints.
Additionally, the service 12 may offer psychological and/or personality testing of members/potential members. Such test(s) could be administered at the center 16 , or online via the service's web-site or the web-site of an independent test administering entity.
Referring now to FIG. 3 , an alternative embodiment of the present invention is shown. In this embodiment, personal information verification for dating is provided for users in an offline forum. Initially, a user would provide personal information to a personal information and authorization receiving center (or potentially to an information collector as discussed in other embodiments above). Once all information is fully screened and verified, the information and authorization center (or the information collector) will provide the user/member with a certification of the personal information. This certification could come in the form of a personal card that could be used in much the same way as a business card, whereby one could present such a personal card to a prospective date in person or when meeting for the first time face-to-face.
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 the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.
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A secure online dating support system and method requires potential members to submit personal information regarding themselves as a predicate to becoming a member of the dating system. This personal information is provided in a manner, either in-person at an information receiving center, or submitted to an information collector, or submitted directly to an online dating service, that permits its verification. Preferably, authorization is also provided by the potential member for further investigation, resulting in an investigator conducting an investigation, and communicating the results to the online dating service, so that the information revealed by the investigation can be displayed to members of the online dating service and/or to individuals outside of the dating service who have been given access by the participating member.
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[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10/763,091, filed Jan. 21, 2004, which claims the benefit of provisional Application No. 60/441,797, filed Jan. 21, 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to astragals and more particularly to locking astragals.
[0004] 2. Background Art
[0005] Double entrance doorways are used in a large variety of residential homes and commercial buildings. Typically, an active door provides for day to day ingress and egress to and from the residential home or building, and an inactive door remains closed, except in instances when a width greater than or equal to the width of the active door and less than or equal to the width of the double entrance doorway is required, such as, for example, for delivery of furniture and/or equipment that cannot fit through the double entrance doorway. If large objects, such as furniture and/or equipment must pass through the double entrance doorway, both the normally inactive door and the active door of the doorway are opened, to create a wide entrance way, through which the furniture and/or equipment may pass.
[0006] Mating edges of the inactive door and the active door do not typically contact one another directly, but are separated by an astragal, the astragal being attached to the edge of an inactive leaf, the astragal extending the length of the inactive door, cushioning the closing of the active door and associated inactive leaf of the doorway, and sealing gaps between the inactive door and the active door.
[0007] The astragals often have upper and lower bolt-slide assemblies, which lock the astragals and the inactive doors to upper and lower portions of a door frame surrounding the double entrance door way. The upper and lower bolt-slide assemblies have bolts, which slide within upper and lower ends of the astragal, and are pushed outwardly from the inactive door to extend beyond the ends of the astragal, and are received by upper and lower apertures in the upper and lower portions of the door frame, also known as the header and threshold sill, respectively, to lock the inactive door in place.
[0008] Stationary seals are typically used at the lower end of the astragals for sealing and preventing drafts from entering the residential homes and/or commercial buildings through the double entrance doorways at the threshold sill. Since many different types, sizes, and shapes of thresholds are used, the drafts remain an unwanted by product of using the stationary sills. In many instances, the fixed size of the seals, and the materials used, for the stationary seals, are either too thick or too thin to fill the gap between the lower end of the astragal and the threshold sill, and, thus, result in not providing an adequate seal, and/or the seal degrading over time.
[0009] There is thus a need for an astragal having self positioning astragal seal that prevents unwanted drafts, is easy to use and install in a quick, convenient, and efficient manner, is durable and long lasting, maintains its seal against drafts over time, even in situations where repeated opening and closing of the inactive door is necessary, and can be used with a variety of astragals and threshold sills, types, sizes, and shapes of threshold sills, doors, and door frames.
[0010] The self positioning astragal seal should be capable of automatically positioning at least one seal at the lower end of the astragal adjacent the threshold sill, and prevent drafts at the vicinity of the lower end of the astragal and the threshold sill, and/or of automatically positioning at least one seal at the upper end of the astragal adjacent the header, and prevent drafts at the vicinity of the header.
[0011] The self positioning astragal seal should independently position itself abuttingly adjacent the sill and/or the header when the bolts are extended from a retracted position to an extended position and are received by the upper and/or lower apertures in the upper and/or lower portions of the door frame.
[0012] The astragal should also have a lock for locking the bolts into the extended position, and unlocking the bolts at a user's discretion, thus, provide additional security.
[0013] Different astragals have heretofore been known. However, none of the astragals adequately satisfies these aforementioned needs.
[0014] Locking astragals have been disclosed. However, none of these astragals adequately satisfies the aforementioned needs.
[0015] U.S. Pat. No. 6,666,486 (Fleming) discloses a slide bolt unit for releasably locking a door or window or the like, such as a semi-active door in a double door entry set. The slide bolt unit includes an elongated slide bolt carried by a channel-shaped housing adapted for recessed mounting into a side edge of a door or the like. An actuator tab on the slide bolt is exposed through a position control slot formed in the housing for fingertip actuation to displace the slide bolt between an advanced position engaging a keeper on an adjacent header or sill or the like to lock the door in a closed position, and a retracted position to permit door opening. The actuator tab has a slotted profile defining lock shoulders biased by a spring for releasably engaging and locking with the housing at opposite ends of the position control slot, and a narrowed central slide track for alignment with the position control slot upon fingertip depression of the actuator tab to permit sliding displacement of the actuator tab along the position control slot from one end to the other.
[0016] U.S. Pat. No. 6,491,326 (Massey, et al.) discloses a swing adaptable astragal with lockable unitary flush bolt assemblies, which includes an improved astragal assembly for double door entryways having an extruded aluminum frame into which upper and lower flush bolt assemblies are slidably disposed. The flush bolt assemblies include a relatively long metal bolt about which is injection overmolded a series of retainer guides, which ride in the frame. Locking mechanisms are also integrally overmolded onto the bolts. The frame and all components of the astragal assembly are symmetrical and reversible so that the assembly is non-handed; that is, it can be adapted to both a right hand swing and a left-hand swing inactive door. A strike plate mounting system and bottom-sealing block are provided, and the upper end of the assembly includes means for sealing against the stop of a head jamb. Drafts at the upper and lower inside corners of the doors of a double door entryway are thus prevented.
[0017] U.S. Pat. No. 6,457,751 (Hartman) discloses a locking assembly for an astragal, which is attached to the inactive door of a double door unit that is installed in a residence or a building. The astragal is attached to the edge of the inactive door in the space between the inactive door and the active door. A separate locking assembly is attached adjacent the top end of the door and also adjacent the bottom end of the door. A plug having an elongated locking bolt extending from the plug is mounted in the front end of the carriage member. Additional structure is provided for reciprocal travel of the carriage member between a locked position and an unlocked position.
[0018] U.S. Pat. No. 6,453,616 (Wright) discloses an astragal for use with exterior double door installations, such as french doors. When attached to the edge of the generally inactive door, the astragal provides a door stop for the active door, a seal to prevent intrusion of water, and a lock for the inactive door. The invention particularly pertains to extruded metal astragals capable of increasing the resistance of the double door system to high wind conditions. The astragal comprises a longitudinally extending base member that has at least one longitudinally extending channel and a pair of spaced apart outwardly extending legs. At least one bolt is slidably inserted in the channel adjacent to one of the first and second ends of the channel. The astragal is attached to the door by at least one cleat whose spaced apart arms engage the legs of the base member, providing resistance to the astragal rocking in relation to the door edge when the doors are under wind forces.
[0019] U.S. Pat. No. 5,857,291 (Headrick) discloses an astragal with integral sealing lock block, for use with a double door installation, which includes an astragal strip secured along the vertical edge of the inactive door. A lock block is slidably disposed in at least one end of said astragal strip and can be moved between an extended position for securing the door and a retracted position for freeing the door. The lock block has a projecting bolt receivable in a receptacle in the door frame, when the lock block is slid to its extended position. A gasket is secured to the end of the lock block, and the bolt passes through an opening in the gasket. The gasket engages and seals against the door frame when the lock block is in its extended position. Gaskets are also provided on the sides of the lock block for engaging and sealing against the doors of the double door installation. When the doors are closed and secured in place, the lock block and gasket assembly prevents drafts from flowing under the door installation beneath the astragal thereof.
[0020] U.S. Pat. No. 5,590,919 (Germano) discloses a T-astragal and sleeve for use with double swinging doors, such as french doors. The T-astragal includes a cap portion perpendicular to a base portion, wherein both the cap and base can be formed from wood, such as plywood or plastic. The T-astragal is a moulding that extends the full height of the swinging doors. One side of the base portion is fixably coupled to the free end of one of the swinging doors by nails or screws. The free end of the other swinging doors is able to swing up to and against a shoulder portion formed from the cap and base portions. A metal pipe shaped sleeve having an approximate length of one foot is partially positioned along the longitudinal axis of the T-astragal molding. A bolt slides within the sleeve from a rest position to an extended position, where the extended position locks the attached door to a matching slot in the door frame.
[0021] U.S. Pat. Nos. 5,350,207 and 5,328,217 (Sanders) disclose a locking astragal for attachment to an inactive leaf of a double doorway, in which an elongated astragal casing has a channel and bolt-slide assemblies mounted slidably within the channel. Each bolt-slide assembly includes a latching member and bolt. By depressing the latching member, the latching member can slide through the channel to extend and lock the bolts into indentations in the upper and lower surfaces of the door frame. The bolts may also be retracted back into the astragal to open the inactive leaf. Each latching member has an integral spring, which simplifies fabrication and assembly.
[0022] U.S. Pat. No. 4,999,950 (Beske, et al.) discloses an inwardly swinging door assembly, which includes a door member hingedly mounted to a frame. A multi-point lock engages the frame at more than one point. Weather stripping is cooperatively connected to the edged surfaces. A pressure equalization member is cooperatively connected to the frame, for engaging the weather strip connected to the bottom edged surface.
[0023] U.S. Pat. No. 4,644,696 (Bursk) discloses a patio door assembly for removable astragal, in which a double door installation includes an astragal, which is removably mounted in the head jamb and sill portions of a door frame independently of the doors, and which includes a locking mechanism in one door which incorporates a bolt arranged to project through the astragal into the other door to effect firm locking of both doors to each other and to the astragal. The mounting for the astragal in the door frame includes a sill anchor, which is fixed on the sill, and is provided with a vertical projection that fits in complementary relation within the hollow lower end of the stem portion of the astragal. At its upper end, the astragal is releasably secured to the head jamb by a latch assembly and an anchor of generally inverted cup shape, which is set in a complementary recess in the head jamb and functions as a keeper for the flush bolt, which is mounted for vertical sliding movement in the hollow upper end of the astragal stem portion.
[0024] U.S. Pat. No. 4,535,578 (Gerken) discloses a seal-actuating mechanism for a wall panel, which when mounted in a wall panel of the type having channel-shaped opposed frame members can be installed, replaced or repaired without removing the exterior finished surface of the wall panel. The seal-actuating mechanism includes a rotatable shaft mounted between the opposed frame members, and an operator member including pivot lever means is mounted on each end thereof. At least one tension member is disposed in the cavity of each frame member, one end of which is coupled to the pivot lever means, and the other end of which is coupled to the shiftable seal assembly, so that when the shaft is rotated the seal assembly is shifted respectively from an extended unlatched position to its retracted latched position.
[0025] U.S. Pat. No. 4,489,968 (Easley) discloses a selectively operable doorstop for converting a double-acting door to a single-acting door. A selectively removable or retractable doorstop for converting double-acting, double or single doors to a single-acting, single door, for permitting control over traffic into and out of public premises at desired times. The doorstop includes an intercept portion which can be selectively removably or retractably inserted into the path of a double-acting door thereby restricting it to opening in one direction only. Different embodiments of the doorstop are provided respectively for temporary or permanent mounting on or in a doorjamb, or on or in the stile of a temporarily fixed-in-place door, thus giving a selection of options for any specific situation.
[0026] U.S. Pat. No. 4,488,378 (Symon) discloses an entrance for buildings, which comprises first and second doors mounted in a common door frame, each door including a lock stile positioned adjacent a lock stile of the other door when the doors are closed. A panic device is mounted on at least one of the doors for emergency opening thereof, and a retractable latch is extended between the stiles of the doors when closed, for minimizing or eliminating the unauthorized forced separation of the stiles into a position wherein the panic device can be actuated with an implement inserted from outside the entrance to release and open the door. Mechanism is included for interconnecting the latch and the panic device for retraction of the latch, when the panic device is actuated for opening the door, thus, providing both a substantially safe and secure entrance system.
[0027] U.S. Pat. No. 4,429,493 (St. Aubin) discloses an astragal housing seal and lock, for use in a double door assembly having an active door and a relatively inactive door. The astragal has a vertically extending mullion housing, which is attached to the free edge of the relatively inactive door. A vertically extending slide section is mounted on the mullion housing on the sealing side of the free edge of the inactive door. The slide section extends from the free vertical edge of the inactive door, when the active door is in the closed position. The slide section is vertically movable from an unlocked position to a locked position, wherein the slide section is moved vertically downward with respect to the mullion housing to engage the sill/threshold of the door frame, thereby preventing movement of the inactive door.
[0028] U.S. Pat. No. 4,262,450 (Anderson) discloses a sliding door structure, including an outer frame, at least one fixed and one movable door panel, and a screen door, the frame including a head having a single, inwardly extending movable door panel guiding fin and all mitered corners, which corners include integral, offset abutment structure for insuring proper alignment of the corners in assembly, weather stripping at both the top and bottom rail of both the fixed and movable door panels, bottom adjusting structure for the movable door panel, and two-member glazing structure for the door panels, capable of resisting high wind force and permitting glazing of the door panels from the inside. The frame and door panels include substantially universal and reversible members. Resilient bumpers, a weather stop, and prowler lock structure permitting locking of the sliding door structure of the movable door panel in a number of selected positions are also disclosed.
[0029] U.S. Pat. No. 4,225,163 (Hubbard, et al.) discloses a panic device actuator for a door, which includes apparatus for unlatching a door mounted in a door frame and one or more elements movable for retracting one or more door latches normally engaged with the door frame for positively locking the door. The panic actuator includes a relatively large panel having an enlarged outer face responsive to pressure applied at any area thereon for unlocking the door without a key. A mounting system is provided for supporting the panel on the door for controlled movement in a horizontal direction in continuous parallelism with the face of the door in a direction normal to the door face. A linkage is provided for interconnecting the panel and the door latching element(s) for moving the same to unlock the door latches in response to pressure movement of the panel on the door.
[0030] U.S. Pat. No. 4,204,369 (Hubbard) discloses an entrance door system, which includes an automatic astragal along an edge of a door and an operator on the door for controlling one or more latch assemblies normally engaged to latch an edge of the door with a member of a door frame in which the door is mounted. The latch assembly is mounted on the door to normally latch the door with the door frame, when the door is closed, and the latch is releasable to an unlatched condition, so that the door may be opened. The elongated astragal is mounted in parallel along the edge of the door and is guided for parallel movement between a retracted and an extended position. The door operator is effective for moving the astragal between retracted and extended positions, and the astragal is interconnected for moving the latch assembly to release the latching engagement, when the astragal is moved to the retracted position, so that the door may be opened.
[0031] U.S. Pat. No. 4,058,332 (DiFazio) discloses an astragal and flush bolt assembly to be secured to a relatively stationary member, such as a door jamb or to the edge of an inactive door of a pair of double doors or the like. The astragal assembly includes a flat metal body mounted on the edge of the stationary member and a metal stop member secured to the body along one edge thereof. The flat body includes first and second spaced apart legs extending outwardly from the stationary member, with the flat body and legs defining a channel to receive and retain a door latch bolt from the active door. The stop member prevents movement of the door in a first direction, and when the latch bolt is engaged in the channel, the channel and the latch bolt prevent the door from moving in the opposite direction. A pair of flush bolts are slidably mounted in the channel, one adjacent each end thereof, so that when the astragal assembly is utilized with double doors, the flush bolts are moved to engage the header and sill, respectively, to hold the inactive door stationary. The astragal body is secured to the stop member by a thermal barrier or thermal break structure to provide thermal insulation between the inside and the outside of the doors. The stop member also includes a weather strip to form a tight seal against the active door, and when metal doors or metal covered doors are used, the weather strip may include a magnetic member to form a seal against the 1 active door.
[0032] U.S. Pat. No. 4,052,819 (Beischel, et al.) discloses a double door astragal, which comprises a rigid support member securable to the vertical edge portion of a normally inactive door, a rigid cover member securable in a plurality of positions relative to the rigid support member and mounted on the rigid support member with a U-shaped portion having an outer leg extending into the swinging path of the active door, and a flexible sealing member secured to the rigid support member and extending into the opening formed by the U-shaped portion of the cover member so as to contact the outside surface of the active door when the vertical edge portions of the active and inactive doors are in abutting relation, to provide an adjustable seal against weather.
[0033] U.S. Pat. No. 4,009,537 (Hubbard) discloses an automatic astragal assembly for inclusion or attachment to a door edge, comprising an elongated astragal housing mounted on the door and having an outwardly opening longitudinal recess therein, an elongated astragal slidably mounted in the recess, means supporting the astragal in the recess for upward and inward relative movement in the housing in response to lifting of the astragal from lifting means mounted on an inside surface of the door, the lifting means including a lift slide mounted on the housing for reciprocal vertical movement and having an L-shaped slot defined therein with an interconnecting horizontal and vertical section and a dead lock pin engaged in the slot and secured to the astragal for elevating the same upon lifting movement of the slide, the vertical section of the slot and the dead lock pin engaging to prevent elevation of the astragal from pressure exerted against an outer edge of the astragal tending to force the astragal horizontally into the recess.
[0034] U.S. Pat. No. 3,997,201 (DeSchaaf, et al.) discloses a latch structure for releasably locking a door to a cabinet, including switch structure for permitting operation of electrical apparatus associated therewith to be operated only when the door is in the latched closed position. The switch is hidden within the door behind the latch bolt, so as to be operated substantially only by the strike which has a preselected configuration, to effect the latching and switch operating operations. The bolt may be operated manually to release the door from the latched condition. A pivotally mounted operator is also disclosed for effecting the unlatching movement of the bolt.
[0035] U.S. Pat. No. 3,940,886 (Ellingson, Jr). discloses a door locking structure forming a panic exit device, consisting of an elongated housing recessed within the leading edge of a door structure, an operating rod including latch bolts disposed in the housing, an astragal seated within a channel formed in the leading edge of the housing, link members connecting the rod and the astragal, and operating means carried by the housing operating the rod to move the astragal inwardly and outwardly of the channel, a plurality of cam headed lug members carried by the rod, a plurality of studs corresponding to the cam members extending rearwardly of the astragal, whereby latching movement of the rods moves the cam members to engage their corresponding studs to hold the astragal in an outward or extended dead locked position.
[0036] Astragals with seals and other astragals have been disclosed. However, none of these astragals adequately satisfies the aforementioned needs.
[0037] U.S. Pat. No. 5,857,291 (Headrick) discloses an astragal with integral sealing lock block, for use with a double door installation, which includes an astragal strip secured along a vertical edge of an inactive door. A lock block is slidably disposed in at least one end of the astragal strip, and can be moved between an extended position, for securing the inactive door, and a retracted position for freeing the inactive door. The lock block has a projecting bolt receivable in a receptacle in a door frame, when the lock block is slid to its extended position. A gasket is secured to an end of the lock block, and the bolt passes through an opening in the gasket. The gasket engages and seals against the door frame, when the lock block is in its extended position. Gaskets are also provided on the sides of the lock block, for engaging and sealing against the doors of the double door installation. When the doors are closed and secured in place, the lock block and gasket assembly prevents drafts from flowing under the door installation beneath the astragal thereof.
[0038] U.S. Pat. Nos. 5,350,207 and 5,328,217 (Sanders) disclose locking astragals, for attaching to an inactive leaf of a double doorway, and in particular U.S. Pat. No. 5,350,207. Each of the locking astragals has an elongated astragal casing, which has a channel and bolt-slide assemblies mounted slidably within the channel. Each bolt-slide assembly includes a latching member and bolt. By depressing the latching member, the latching member can slide through the channel, to extend and lock the bolts into indentations in upper and lower surfaces of a door frame. The bolts may also be retracted back into the astragal, to open the inactive leaf. Each of the latching members has an integral spring, which simplifies fabrication and assembly.
[0039] U.S. Pat. No. 6,491,326 (Massey, et al) discloses a swing adaptable astragal with lockable unitary flush bolt assemblies, for double door entryways, which includes an extruded aluminum frame into which upper and lower flush bolt assemblies are slidably disposed. The flush bolt assemblies include a long metal bolt about which is injection overmolded a series of retainer guides, which ride in the frame. Locking mechanisms are also integrally overmolded onto the bolts. The frame and all components of the astragal assembly are symmetrical and reversible, so that the assembly is non-handed; that is, it can be adapted to both a right hand swing and a left-hand swing inactive door. A strike plate mounting system and bottom-sealing block are provided, and the upper end of the assembly includes means for sealing against a stop of a head jamb. Drafts at upper and lower inside corners of the doors of a double door entryway may be prevented.
[0040] U.S. Pat. No. 6,125,584 (Sanders) discloses an automatic door bottom for a hinged door, which is pivotable to be positioned over a sill when closed, the door having a hinge side and a width, the door bottom having an inverted channel having an open bottom, a length corresponding to the door width and a hinge end corresponding to the hinge side of the door; a sealing member having a length corresponding to the length of the channel, the sealing member being housed in the channel and being movable vertically downwardly into a sealing position, in which the sealing member contacts the sill when the door is closed; and a displacement mechanism installed in the channel and coupled to the sealing member, for moving the sealing member vertically into the sealing position in response to closing of the door, wherein the displacement mechanism is coupled to the sealing member at a plurality of points along the length of the sealing member, and is operative to move the end of the sealing member at the hinge side of the channel into the sealing position, prior to the remainder of the sealing member, during closing of the door.
[0041] U.S. Pat. No. 6,457,751 (Hartman) discloses a locking assembly for an astragal, which can be attached to an inactive door of a double door unit of a residence or a building. The astragal is attached to an edge of the inactive door in space between the inactive door and active door. A separate locking assembly is attached adjacent a top end of the door and also adjacent a bottom end of the door. A plug having an elongated locking bolt extending therefrom is mounted in a front end of a carriage member. Additional structure is provided for reciprocal travel of the carriage member between a locked position and an unlocked position.
[0042] U.S. Pat. No. 5,335,450 (Procton) discloses an astragal, which has an exterior aluminum extrusion and an interior wooden portion. The exterior extrusion includes a pair of rearwardly extending center walls, which form a channel for receiving the wooden interior portion. Attachments and door hardware can be installed in the wooden interior portion, while the extruded exterior acts as cladding.
[0043] U.S. Pat. No. 5,590,919 (Germano) discloses a T-astragal and sleeve for door, for use with double swinging doors, such as for french doors. The T-astragal includes a cap portion perpendicular to a base portion, wherein both the cap and base can be formed from wood, such as plywood or plastic. The T-astragal is a molding that extends the full height of the swinging doors. One side of the base portion is fixably coupled to the free end of one of the swinging doors by nails or screws. The free end of the other swinging doors is able to swing up to and against a shoulder portion formed from the cap and base portions. A metal pipe shaped sleeve having an approximate length of one foot is partially positioned along the longitudinal axis of the T-astragal molding. A bolt slides within the sleeve from a rest position to an extended position, where the extended position locks the attached door to a matching slot in the door frame.
[0044] U.S. Pat. No. 4,429,493 (St. Aubin) discloses an astragal housing seal and lock, for use in a double door assembly having an active door and a relatively inactive door. The astragal has a vertically extending mullion housing, which is attached to a free edge of the relatively inactive door. A vertically extending slide section is mounted on the mullion housing on a sealing side of the free edge of the inactive door. The slide section extends from the free vertical edge of the inactive door, when the active door is in the closed position. The slide section is vertically movable from an unlocked position to a locked position, wherein the slide section is moved vertically downward, with respect to the mullion housing, to engage the sill/threshold of the door frame, thereby preventing movement of the inactive door.
[0045] U.S. Pat. No. 4,058,332 (DiFazio) discloses an astragal and flush bolt assembly to be secured to a relatively stationary member such as a door jamb or to the edge of an inactive door of a pair of double doors or the like. The astragal assembly includes a flat metal body mounted on the edge of the stationary member and a metal stop member secured to the body along one edge thereof. The flat body includes first and second spaced apart legs extending outwardly from the stationary member, with the flat body and legs defining a channel to receive and retain a door latch bolt from the active door. The stop member prevents movement of the door in a first direction, and when the latch bolt is engaged in the channel, the channel and latch bolt prevent the door from moving in the opposite direction. A pair of flush bolts are slidably mounted in the channel, one adjacent each end thereof, so that when the astragal assembly is utilized with double doors, the flush bolts are moved to engage the header and sill, respectively, to hold the inactive door stationary. The astragal body is secured to the stop member by a thermal barrier or thermal break structure, to provide thermal insulation between the inside and the outside of the doors. The stop member also includes a weather strip to form a seal against the active door, and when metal doors or metal covered doors are used, the weather strip may include a magnetic member to form a seal against the active door.
[0046] U.S. Pat. No. 6,453,616 (Wright) discloses an astragal for use with exterior double door installations, such as french doors. When attached to the edge of a generally inactive door, the astragal provides a door stop for an active door, a seal to prevent intrusion of water, and a lock for the inactive door. The invention particularly pertains to extruded metal astragals, capable of increasing the resistance of the double door system to high wind conditions. The astragal comprises a longitudinally extending base member that has at least one longitudinally extending channel and a pair of spaced apart outwardly extending legs. At least one bolt is slidably inserted in the channel adjacent to one of the first and second ends of the channel. The astragal is attached to the door, by at least one cleat whose spaced apart arms engage the legs of the base member, providing resistance to the astragal rocking in relation to the door edge, when the doors are subject to wind forces.
[0047] U.S. Pat. No. D293,719 (Stepanian) discloses a combined astragal extrusion and seal.
[0048] For the foregoing reasons, there is a need for a self positioning astragal seal that prevents unwanted drafts, is easy to use and install in a quick, convenient, and efficient manner, is durable and long lasting, maintains its seal against drafts over time, even in situations where repeated opening and closing of the inactive door is necessary, and can be used with a variety of astragals and threshold sills, types, sizes, and shapes of threshold sills, doors, and door frames. The self positioning astragal seal should be capable of automatically positioning at least one seal at the lower end of the astragal adjacent the threshold sill, and prevent drafts at the vicinity of the lower end of the astragal and the threshold sill, and/or of automatically positioning at least one seal at the upper end of the astragal adjacent the header, and prevent drafts at the vicinity of the header. The self positioning astragal seal should independently position itself abuttingly adjacent the sill and/or the header when the bolts are extended from a retracted position to an extended position and are received by the upper and/or lower apertures in the upper and/or lower portions of the door frame. The astragal should also have a lock for locking the bolts into the extended position, and unlocking the bolts at a user's discretion, thus, provide additional security.
SUMMARY
[0049] The present invention is directed to a locking astragal and a locking astragal with a self positioning astragal seal that automatically positions at least one seal at the lower end of an astragal adjacent the threshold sill of a door frame, and prevent drafts at the vicinity of the lower end of the astragal and the threshold sill, and/or of automatically positions at least one seal at the upper end of the astragal adjacent the header of the door frame, and prevent drafts at the vicinity of the header. The self positioning astragal seal independently positions itself abuttingly adjacent the sill and/or the header when the astragal's bolts are extended from a retracted position to an extended position and are received by the upper and/or lower apertures in the upper and/or lower portions of the door frame. The self positioning astragal seal prevents unwanted drafts, is easy to use and install in a quick, convenient, and efficient manner, is durable and long lasting, maintains its seal against drafts over time, even in situations where repeated opening and closing of the inactive door is necessary, and can be used with a variety of astragals and threshold sills, types, sizes, and shapes of threshold sills, doors, and door frames. The astragal also has a lock for locking the bolts into the extended position, and unlocking the bolts at a user's discretion, thus, provide additional security.
[0050] The locking astragal has a bolt having a bolt retracted position and a bolt extended position, spring means and a latching mechanism having a latch; the latching mechanism retracting the bolt into the bolt retracted position and compressing the spring means when the latch is retracted to a latch retracted position; the latching mechanism releasing the bolt and the spring means forcing the bolt into the bolt extended position and the latch into a latch released position when the latch is released, and an astragal lock, which locks the bolt into the bolt extended position when the astragal lock is locked and unlocks the bolt when the astragal lock is unlocked, which when unlocked allows the bolt to be moved from the bolt extended position to the bolt retracted position and from the bolt retracted position to the bolt extended position. The astragal lock has a lock cylinder, which is rotatably mounted to the astragal, the lock cylinder having an axis substantially perpendicular to the axis of the astragal bolt, and a notch, which has an axis substantially perpendicular to the axis of the lock cylinder, the notch preferably having an arcuate shape and slidably matingly accepting at least a portion of the astragal bolt therethrough when the astragal lock is unlocked and in an unlocked position, the lock cylinder preventing movement of the astragal bolt and locking the astragal bolt in the bolt extended position, when the lock cylinder is rotated into a locked position, which is substantially perpendicular to the unlocked position. The lock cylinder also has a stop, which limits the angular rotation of the lock cylinder to substantially ninety degrees.
[0051] An astragal having features of the present invention comprises: a bolt having a bolt retracted position and a bolt extended position; a lock having a locked position and an unlocked position, the lock locking the bolt into the bolt extended position when the bolt is in the bolt extended position and the lock is in the locked position, the lock having a wall, which prevents movement of the bolt and locks the bolt into the bolt extended position, when the bolt is in the bolt extended position and the lock is in the locked position; the lock unlocking the bolt when the lock is in the unlocked position, the lock having a keyway, which allows at least a portion of the bolt to pass therethrough when the bolt is unlocked.
[0052] Another astragal having features of the present invention comprises: a bolt having a bolt retracted position and a bolt extended position; a lock having a locked position and an unlocked position, the lock locking the bolt into the bolt extended position when the bolt is in the bolt extended position and the lock is in the locked position, the lock unlocking the bolt when the lock is in the unlocked position; a seal block having a catch and a hole, the bolt slidably disposed through the hole, the catch catching a portion of the bolt and holding the seal block in a seal block retracted position when the bolt is in the bolt retracted position and releasing the seal block when the bolt is in the bolt extended position; spring means forcing the seal block into a seal block extended position when the seal block is released.
DRAWINGS
[0053] These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
[0054] FIG. 1 is a perspective view of a locking astragal with a self positioning astragal seal, constructed in accordance with the present invention, shown locked with a bolt and the self positioning astragal seal extended;
[0055] FIG. 1A is a perspective section view of the locking astragal with the self positioning astragal seal of FIG. 1 ;
[0056] FIG. 1B is a section view of the locking astragal with the self positioning astragal seal of FIG. 1 ;
[0057] FIG. 1C is an exploded section view of the locking astragal with the self positioning astragal seal of FIG. 1 ;
[0058] FIG. 2 is a perspective view of a locking astragal with the self positioning astragal seal, shown unlocked with the bolt and the self positioning astragal seal retracted;
[0059] FIG. 2A is a perspective section view of the locking astragal with the self positioning astragal seal of FIG. 2 ;
[0060] FIG. 2B is a section view of the locking astragal with the self positioning astragal seal of FIG. 2 ;
[0061] FIG. 2C is an exploded section view of the locking astragal with the self positioning astragal seal of FIG. 2 ;
[0062] FIG. 3 is an exploded view of the locking astragal with the self positioning astragal seal and a latching mechanism;
[0063] FIG. 4 is an exploded view of selected components of the locking astragal with the self positioning astragal seal and a portion of the latching mechanism of FIG. 3 ;
[0064] FIG. 5 is an exploded view of the latching mechanism of FIG. 3 ;
[0065] FIG. 6 is a perspective view of entrance doors, comprising an inactive door, shown in a closed position, and an active door;
[0066] FIG. 7 is a perspective view of the inactive door, showing the locking astragal with the self positioning astragal seal installed on the inactive door, shown locked with the bolt and the self positioning astragal seal extended;
[0067] FIG. 8 is a section view of the locking astragal with the self positioning astragal seal, shown locked with the bolt and the self positioning astragal seal extended;
[0068] FIG. 9 is a section view of the locking astragal with the self positioning astragal seal, shown locked with the bolt and the self positioning astragal seal extended;
[0069] FIG. 10 is another section view of the locking astragal with the self positioning astragal seal, with the bolt and the self positioning astragal seal extended;
[0070] FIG. 11 is another section view of the locking astragal with the self positioning astragal seal, with the bolt and the self positioning astragal seal extended;
[0071] FIG. 12 is another section view of the locking astragal with the self positioning astragal seal, with the bolt and the self positioning astragal seal extended;
[0072] FIG. 13 is another section view of the locking astragal with the self positioning astragal seal, with the bolt and the self positioning astragal seal extended;
[0073] FIG. 14 is another section view of the locking astragal with the bolt and the self positioning astragal seal, with the self positioning astragal seal extended;
[0074] FIG. 15 is a section view of the latching mechanism of FIG. 3 , along a portion of line 8 - 8 of FIG. 7 , with the bolt and the self positioning astragal seal extended;
[0075] FIG. 16 is a section view of the locking astragal with the self positioning astragal seal, along a portion of line 8 - 8 of FIG. 7 , shown locked with the bolt and the self positioning astragal seal extended;
[0076] FIG. 17 is a section view of the locking astragal with the self positioning astragal seal, shown unlocked with the bolt and the self positioning astragal seal retracted;
[0077] FIG. 18 is another section view of the locking astragal with the self positioning astragal seal, shown unlocked with the bolt and the self positioning astragal seal retracted;
[0078] FIG. 19 is an exploded view of an upper bolt and latching mechanism of the astragal of FIG. 7 ;
[0079] FIG. 20 is a section view of an alternate embodiment of a locking astragal with a self positioning astragal seal, shown installed on the inactive door;
[0080] FIG. 21 is a section view of an alternate embodiment of a locking astragal with a self positioning astragal seal, shown installed on the inactive door;
[0081] FIG. 22 is a section view of an alternate embodiment of a locking astragal with a self positioning astragal seal, shown installed on the inactive door and also showing the active door;
[0082] FIG. 23 is a section view of an alternate embodiment of a locking astragal with a self positioning astragal seal, shown installed on the inactive door and also showing the active door;
[0083] FIG. 24 is a section view of an alternate embodiment of a locking astragal with a self positioning astragal seal, shown installed on the inactive door and also showing the active door;
[0084] FIG. 25 is a section view of an alternate embodiment of a locking astragal with a self positioning astragal seal, shown installed on the inactive door and also showing the active door; and
[0085] FIG. 26 is a perspective view of a locking astragal, constructed in accordance with the present invention, shown locked with a bolt extended;
[0086] FIG. 26A is a perspective section view of the locking astragal of FIG. 26 ;
[0087] FIG. 26B is a section view of the locking astragal of FIG. 26 ;
[0088] FIG. 26C is an exploded section view of the locking astragal of FIG. 26 ;
[0089] FIG. 27 is a perspective view of the locking astragal of FIG. 26 , shown unlocked with the bolt retracted;
[0090] FIG. 27A is a perspective section view of the locking astragal of FIG. 27 ;
[0091] FIG. 27B is a section view of the locking astragal of FIG. 27 ;
[0092] FIG. 27C is an exploded section view of the locking astragal of FIG. 27 ;
[0093] FIG. 28 is an exploded view of the locking astragal of FIGS. 26 and 27 and a latching mechanism;
[0094] FIG. 29 is another exploded view of the locking astragal of FIGS. 26 and 27 and the latching mechanism of FIG. 28 ;
[0095] FIG. 30 is an exploded view of the locking astragal of FIGS. 26 and 27 ;
[0096] FIG. 31 is an exploded view of the latching mechanism of FIGS. 28 and 29 ;
[0097] FIG. 32 is a perspective view of entrance doors, comprising an inactive door, shown in a closed position, and an active door, with the locking astragal of FIGS. 26 and 27 installed on inactive door; and
[0098] FIG. 33 is a perspective view of the inactive door of FIG. 32 , showing the locking astragal of FIG. 26 installed on the inactive door, shown locked with the bolt extended.
REFERENCE NUMERALS
[0099] These and other features, aspects, and advantages of the present invention will become better understood with regard to the references and associated reference numerals of the following description and accompanying drawings where:
1 locking astragal with self positioning astragal seal 2 lock 42 inactive door edge 44 inactive door 46 sill 48 door frame 52 elongated guide 54 elongated guide channel 56 lower bolt 58 shoulder 60 astragal bottom 86 compression spring guide holder 88 compression spring bottom end 90 base top 92 barrel 94 barrel extension 96 barrel extension arcuate interior 98 extension 100 extension arcuate interior 102 T top portion 104 arcuate interior 105 angled edges 106 shoulder 108 face plate reinforcement 110 face plate stop 112 guide block edge stop 114 guide block reinforcement 116 guide block stop 130 astragal recess 132 astragal extension stop 134 astragal retraction stop 136 astragal opposing side 138 astragal side 140 astragal side 142 side channel 144 threaded hole 146 threaded hole 148 set screw 150 angled longitudinal channel edge 158 face plate exterior side 160 active door edge 162 active door 164 header 180 astragal housing 182 longitudinal channel 184 longitudinal retention guide 185 channel base 186 lockset strike 188 deadbolt strike 190 upper bolt 191 upper bolt assembly 192 lockset 194 deadbolt 196 lockset cover plate 198 deadbolt cover plate 199 screws 200 latching member 202 pull block 204 elongated connector 206 compression spring 208 slide plate 210 bolt lower portion 212 bolt mid portion 214 bolt upper portion 216 bolt slot 218 bolt hole 220 end pin 222 elongated connector hole 224 pin 226 pin 228 pull block track 230 pull block retention track 232 pull block retention track 234 pull block channel 236 pull block channel 238 pull block notch 240 pull block base 242 pull block notch 244 pull block bearing notch 246 pull block notch side 248 lever arm receiving hole 250 lever arm 252 trunnion 254 spring tail 256 latching dog 260 slide plate retraction hole 262 slide plate extension hole 264 slide plate notch 266 slide plate end tab 268 slide plate projecting tab 270 slide plate projecting notch 280 elongated guide notched recess 282 elongated guide end 284 pull block arrow marking 286 arcuate side 288 arcuate base 289 oblique angled side portion 290 longitudinally disposed side channel base wall 291 longitudinally disposed side channel side wall 292 lock mounting hole 293 lock cylinder 294 arcuate keyway 295 arcuate tab 296 lock stop 297 unlock stop 298 head 299 slot 300 alternate astragal housing 302 saw tooth recess 304 finned tail 306 foam weather strip 308 cavity 310 alternate astragal housing 312 thermal break 314 slot 320 alternate astragal 322 alternate astragal housing 324 cover 326 outer seal 328 inner seal 330 alternate astragal 332 thermal break 340 alternate astragal 342 cover element 344 saw tooth recess 346 finned tail 348 weather strip seal 349 inner seal 350 alternate astragal 352 thermal break 400 mounting shoulder 402 bearing surface 404 astragal longitudinal wall 406 lock contact area 408 unlock contact area 410 lock cylinder wall 412 bolt top contact portion 414 other bolt top portion 416 bolt portion 500 locking astragal 552 elongated guide 554 longitudinal channel 556 upper bolt 558 shoulder 636 planar side 638 planar side 640 side 642 side channel 644 threaded hole 646 threaded hole 648 set screws 660 astragal top 710 bolt lower portion 714 bolt upper portion 716 slot 718 hole 786 elongated guide arcuate side 788 arcuate base 789 oblique angled side portion 790 base wall 791 side wall 792 lock mounting hole 904 longitudinal wall 906 lock contact area 908 unlock contact area 912 bolt top contact portion 914 other bolt top portion 916 bolt portion
DESCRIPTION
[0268] The preferred embodiments of the present invention will be described with reference to FIGS. 1-33 of the drawings. Identical elements in the various figures are identified with the same reference numbers.
[0269] FIGS. 1-19 show an embodiment of the present invention, a locking astragal with self positioning astragal seal 1 , which has a lock 2 and a self positioning astragal seal 10 . The self positioning astragal seal 10 comprises a seal block 12 having a substantially centrally disposed hole 14 therethrough, a shoulder 16 , compression springs 18 , and end seal 20 , for use with an astragal 30 .
[0270] The astragal 30 is mounted to edge 42 of inactive door 44 , and the self positioning astragal seal 10 is mounted to the astragal 30 adjacent sill 46 of door frame 48 , as shown in FIGS. 6 and 7 . The astragal 30 has an elongated guide 52 having a substantially centrally disposed longitudinal channel 54 and a bolt 56 having a shoulder 58 , the bolt 56 slidably mounted therein the substantially centrally disposed longitudinal channel 54 .
[0271] The astragal seal shoulder 16 catches the bolt shoulder 58 when the bolt 56 is retracted to a retracted position, as shown in FIGS. 2, 17 , and 18 , and is released from the bolt shoulder 58 when the bolt 56 is extended to an extended position, as shown in FIGS. 1 and 7 - 16 , the compression springs 18 forcing the seal block 12 into an extended position, when the bolt 56 is in the bolt extended position. The seal block 12 is, thus, retracted to a retracted position, the astragal seal shoulder 16 catching and abutting the bolt shoulder 58 , and holding the seal block 12 in a seal block retracted position when the bolt 56 is in the bolt retracted position. The seal block 12 is extended to the seal block extended position, when the astragal seal shoulder 16 is released from the bolt shoulder 58 , the compression springs 18 forcing the seal block 12 into the seal block extended position, when the bolt 56 is in the bolt extended position. The astragal seal shoulder 16 , thus, acts as a catch, which catches the bolt shoulder 58 when the bolt 56 is retracted to the bolt retracted position, and is released from the bolt shoulder 58 when the bolt 56 is extended to the bolt extended position.
[0272] FIGS. 1 , 1 A- 1 C, 7 - 9 , and 16 show the bolt 56 locked into the bolt extended position with the lock 2 locked. FIGS. 2 , 2 A- 2 C, 17 , and 18 show the bolt 56 in the bolt retracted position with the lock 2 unlocked.
[0273] The self positioning astragal seal 10 automatically and independently adjusts itself to fit snugly and fill any gaps between bottom 60 of the astragal 30 and the sill 46 of the door frame 48 , when the bolt 56 is in the bolt extended position, thus, preventing unwanted drafts between bottom 74 of the seal block 12 and the sill 46 of the door frame 48 , the compression springs 18 forcing the seal block 12 opposingly away from the bottom 60 of the astragal 30 and forcing the end seal 20 , which is affixed to the bottom 74 of the seal block 12 , to abut the sill 46 of the door frame 48 .
[0274] The seal block 12 has base 78 , face plate 80 , and guide block 82 , which is adjacent the inactive door edge 42 , when the self positioning astragal seal 10 and the astragal are installed on the inactive door 44 and the seal block 12 is in the retracted position, the face plate 80 and the guide block 82 being substantially perpendicular to the base 78 , and substantially parallel one to the other.
[0275] The seal block 12 has substantially “T” shaped member 84 integral with the guide block 82 and compression spring guide holders 86 , which hold the compression springs 18 in place, the compression springs 18 being mounted about the compression spring holders 86 , with bottom ends 88 of the compression springs 18 abutting top 90 of the base 78 . The seal block 12 has barrel 92 integral with the guide block 82 , the barrel 92 having the substantially centrally disposed hole 14 therethrough to the bottom 74 of the seal block 12 , the bolt 56 slidable therethrough the substantially centrally disposed hole 14 , and the seal block 12 slidable about the bolt 56 . The barrel 92 has extension 94 , which is integral with the barrel 92 , having arcuate interior 96 , which is substantially collinear with the interior of the barrel 92 , and extension 98 having the shoulder 16 and arcuate interior 100 . The substantially “T” shaped member 84 has T top portion 102 , which has arcuate interior 104 , angled edges 105 , and shoulder 106 . The face plate 80 has reinforcements 108 having stops 110 . The guide block 82 has edge stops 112 and reinforcements 114 having stops 116 . The compression spring holders 86 have splines for reinforcement.
[0276] The elongated guide 52 of the astragal 30 has recesses 130 , which have extension stops 132 and retraction stops 134 at opposing ends thereof, and substantially planar opposing side 136 . The elongated guide 52 of the astragal 30 has substantially planar side portions 138 adjacent the recesses 130 , which oppose the substantially planar opposing side 136 , and sides 140 , which are substantially perpendicular to the substantially planar side portions 138 , the recesses 130 , and the substantially planar opposing side 136 . The elongated guide 52 also has opposing longitudinally disposed side channels 142 . The substantially planar side portions 138 and the substantially planar opposing side 136 have threaded holes 144 and 146 , respectively, therethrough, opposing one another, having set screws 148 therein, the set screws 148 extending across the longitudinally disposed side channels 142 . The elongated guide 52 also has angled longitudinal edges 150 atop the substantially centrally disposed longitudinal channel 54 adjacent the recesses 130 and the substantially planar side portions 138 .
[0277] The substantially “T” shaped member 84 and the face plate 80 of the seal block 12 matingly sandwich the recesses 130 and the substantially planar opposing side 136 of the astragal 30 , respectively, therebetween, and retain the seal block 12 slidably mating about the elongated guide 52 between the seal block retracted position and the seal block extended position, and vice versa.
[0278] The compression springs 18 are mounted about the compression spring holders 86 , with the bottom ends 88 of the compression springs 18 abutting the top 90 of the base 78 of the seal block 12 and top 152 of the compression springs 18 abutting the set screws 148 in the longitudinally disposed side channels 142 of the astragal 30 . The compression springs 18 are held in the longitudinally disposed side channels 142 of the astragal 30 under compression, the extension stops 132 of the astragal 30 preventing the compression springs 18 from forcing the substantially “T” shaped member 84 out of the recesses 130 .
[0279] The barrel 92 of the seal block 12 is matingly slidable about the bolt 56 of the astragal 30 , and the bolt 56 is matingly slidable therethrough the substantially centrally disposed hole 14 of the barrel 92 of the seal block 12 . The angled edges 105 of the substantially “T” shaped member 84 matingly abut the angled longitudinal edges 150 of the astragal 30 . The angled edges 105 of the substantially “T” shaped member 84 and the barrel 92 of the guide block 82 guide the seal block 12 collinearly with the angled longitudinal edges 150 of the astragal 30 and the substantially centrally disposed longitudinal channel 54 , the bolt 56 being substantially aligned with the substantially centrally disposed longitudinal channel 54 .
[0280] The extension stops 132 and the retraction stops 134 limit the extent of travel of the substantially “T” shaped member 84 , and, thus, limit the extent of travel of the seal block 12 and the end seal 20 from the seal block extended position to the seal block retracted position, respectively, the compression springs 18 forcing the seal block 12 into the extended position, other than when the seal block 12 is retracted. The seal block 12 is retracted to the retracted position, the astragal seal shoulder 16 catching and abutting the bolt shoulder 58 , and holding the seal block 12 in the seal block retracted position, when the bolt 56 is in the bolt retracted position. The seal block 12 is extended to the seal block extended position, when the astragal seal shoulder 16 is released from the bolt shoulder 58 , the compression springs 18 forcing the seal block 12 into the seal block extended position, when the bolt 56 is in the bolt extended position.
[0281] The end seal 20 has substantially centrally disposed hole 154 therethrough, which is substantially aligned collinearly with the substantially centrally disposed hole 14 of the seal block 12 , which allows the end seal 20 to slide about the bolt 56 , and vice versa.
[0282] The self positioning astragal seal 10 has face seal 156 , which is affixed to exterior side 158 of the face plate 78 of the seal block 20 and abuts edge 160 of active door 162 , when the active door 162 is closed abuttingly against the inactive door 44 , thus, preventing unwanted drafts between the self positioning astragal seal 10 and the edge 160 of the active door 162 . The astragal 30 also has edge seal 163 .
[0283] The self positioning astragal seal 10 may be used with the astragal 30 adjacent the sill 46 and/or header 164 of the door frame 48 , and may be used with the inactive door 44 and/or the active door 162 . Typical installations, however, have the astragal 30 mounted to the edge 42 of the inactive door 44 , and the self positioning position astragal end seal 20 mounted to the astragal 30 adjacent the sill 46 .
[0284] The self positioning astragal seal 10 may be used with a variety of astragals but is preferably used with the astragal 30 shown in the accompanying figures. Other astragals may be modified to suit the needs of particular applications.
[0285] The end seal 20 and the face seal 156 may have adhesives covered by peel off adhesive strips 166 and 168 , respectively, the end seal 20 and the face seal 156 being fastened to the seal block 12 with the adhesives, upon removal of the adhesive strips 166 and 168 , respectively.
[0286] The astragal 30 has astragal housing 180 having longitudinal channel 182 , which has longitudinal retention guides 184 , the elongated guide 52 inserted into the longitudinal channel 182 and held in the longitudinal channel 182 by the retention guides 184 and the set screws 148 , and channel base 185 , the set screws 148 locking the elongated guide 52 into the astragal housing 180 . The astragal 30 also has lockset strike 186 , deadbolt strike 188 , and upper bolt 190 mounted to the longitudinal channel 182 of the astragal housing 180 , the bolt 56 and the upper bolt 190 being used to lock the astragal 30 , and, thus, the inactive door 44 , which the astragal 30 is affixed to, to the sill 46 and the header 164 , respectively, of the door frame 48 . The upper bolt 190 may be used with the self positioning astragal seal 10 and/or alternatively the upper bolt 190 may use an alternative sealing means. Upper bolt assembly 191 having the upper bolt 190 is installed into the longitudinal channel 182 in substantially the same manner as the elongated guide 52 . The active door 162 has lockset 192 and deadbolt 194 , which are received by lockset strike 186 , deadbolt strike 188 , respectively, on the inactive door 44 , for securing the active door 162 to the inactive door 134 when the active door 162 is closed abuttingly adjacent the inactive door 44 . The astragal housing 180 has lockset cover plate 196 and deadbolt cover plate 198 , which are mounted to the astragal housing 180 , the lockset strike 186 and the deadbolt strike 188 being fastened to the lockset cover plate 196 and the deadbolt cover plate 198 with screws 199 .
[0287] The astragal 30 has latching member 200 , pull block 202 , elongated connector 204 , compression spring 206 about the elongated connector 204 , and slide plate 208 . The bolt 56 has lower portion 210 , mid portion 212 adjacent the shoulder 58 , the mid portion 212 having a smaller diameter than the diameter of the lower portion 210 , and upper portion 214 , the upper portion 214 of the bolt 56 having substantially the same diameter as the lower portion 210 , and having a slot 216 therethrough and a hole 218 therethrough, the slot 216 and the hole 218 substantially perpendicular one to the other.
[0288] The elongated connector 204 has end pin 220 , opposing hole 222 , and pin 224 therebetween, the end pin 220 and the pin 224 substantially perpendicular to the plane of the elongated connector 204 . The elongated connector 204 is sandwiched in the slot 216 of the upper portion 214 of the bolt 56 , the hole 218 and the hole 222 aligned one with the other, the bolt 56 and the elongated connector 204 pinned one to the other with pin 226 , the pin 226 therethrough the holes 222 and 218 .
[0289] The pull block 202 has longitudinal tracks 228 , retention tracks 230 and 232 , and channels 234 and 236 , the channels 234 between the longitudinal tracks 228 and the retention tracks 230 , and the channels 236 between the longitudinal tracks 230 and the retention tracks 232 . The pull block 202 is inserted into the longitudinal channel 182 of the astragal housing 180 , the channels 234 and 236 being adjacent to the retention guides 184 of the astragal housing 180 , the retention guides 184 slidably retaining the pull block 204 in the astragal housing 180 . The pull block 202 has substantially centrally disposed notch 238 at base 240 of the pull block 202 , notch 242 adjacent and substantially perpendicular to the substantially centrally disposed notch 238 , and bearing notches 244 . The substantially centrally disposed notch 238 is adjacent to and surrounds the elongated connector 204 adjacent the end pin 220 of the elongated connector 204 ; and sides 246 of the notch 242 surround and abut the end pin 220 , thus, pinning the elongated connector 204 to the pull block 202 one to the other. The pull block 202 also has lever arm receiving hole 248 .
[0290] The latching member 200 has lever arm 250 , which has trunnions 252 protruding therefrom, spring tail 254 , and latching dog 256 .
[0291] The slide plate 208 has retraction hole 260 , extension hole 262 , notches 264 , which form end tabs 266 , and projecting tabs 268 , which form projecting notch 270 therebetween, the projecting notch 270 for matingly slidably receiving the elongated connector 204 therebetween.
[0292] The elongated guide 52 is locked into the astragal housing 180 with the set screws 148 . The elongated guide 52 has notched recesses 280 opposing the recesses 130 , the notched recesses 280 matingly receiving the end tabs 266 of the slide plate 208 therein, and adjacent ends 282 , the notches 264 of the slide plate 208 matingly receiving the ends 282 of the elongated guide 52 therein, the slide plate 208 being sandwiched and locked between the elongated guide 52 and the channel base 185 of the astragal housing 180 . The projecting notch 270 of the slide plate 208 slidably guides the elongated connector 204 , which is located in the projecting notch 270 , substantially collinear with the center line of the elongated guide 52 .
[0293] The latching member 200 is sandwiched between the pull block 202 and the slide plate 208 , with the trunnions 252 in the bearing notches 244 of the pull block 202 and the lever arm 250 extending through the lever arm receiving hole 248 of the pull block 202 , thus facilitating operator control.
[0294] The retraction hole 260 and the extension hole 262 of the latching member 200 matingly receive the latching dog 256 of the latching member 200 therein.
[0295] The latching member 200 may be retracted to a latching member retracted position, when the lever arm 250 of the pull block 202 is depressed and pushed in the direction of pull block arrow marking 284 , which pulls the elongated connector 204 in the direction of the pull block arrow marking 284 , pulls the bolt 56 into the bolt retracted position, pulls the seal block 12 into the seal block retracted position, compresses the compression springs 18 , and compresses the compression spring 206 between the pin 224 of the elongated connector 204 and the projecting tabs 268 of the slide plate 208 . When the latching member 200 is retracted to the latching member retracted position, the spring tail 254 of the latching member 200 forces the latching dog 256 into the retraction hole 260 of the slide plate 208 , thus, locking the bolt 56 into the bolt retracted position and locking the seal block 12 into the seal block retracted position.
[0296] The latching member 200 may be released into a latching member extended position from the latching member retracted position, when the lever arm 250 of the pull block 202 is depressed and released, releasing compression from the compression spring 206 between the pin 224 of the elongated connector 204 and the projecting tabs 268 of the slide plate 208 , forcing the elongated connector 204 in the direction opposing the pull block arrow marking 284 , forcing the bolt 56 into the bolt extended position, releasing compression on the compression springs 18 , which forces the seal block 12 into the seal block extended position. When the latching member 200 is released, the latching member 200 snaps into latching member extended position, the latching dog 256 snaps into the extension hole 262 of the slide plate 208 , the spring tail 254 of the latching member 200 forcing the latching dog 256 into the extension hole 262 , thus, locking the bolt 56 into the bolt extended position with the seal block 12 in the seal block extended position, the seal block 12 automatically and independently self positioned with the end seal 20 abutting the sill 46 of the door frame 48 . The latching member 200 may alternatively be pushed into the latch member extended position.
[0297] The substantially centrally disposed longitudinal channel 54 of the elongated guide 52 has arcuate sides 286 and arcuate base 288 to slidably and matingly accommodate the bolt 56 , the lower portion 210 and the upper portion 214 of which are substantially cylindrical and have substantially the same diameter. The mid portion 212 of the bolt 56 is also substantially cylindrical, but has a smaller diameter than the diameter than that of the lower portion 210 and the upper portion 214 .
[0298] The elongated guide 52 also has oblique angled side portions 289 between the substantially planar side portions 138 and the arcuate sides 286 of the substantially centrally disposed longitudinal channel 54 . The longitudinally disposed side channels 142 have base walls 290 , which oppose the arcuate sides 286 of the substantially centrally disposed longitudinal channel 54 , and side walls 291 opposingly adjacent the substantially planar opposing side 136 .
[0299] Again, FIGS. 1 , 1 A- 1 C, 7 - 9 , and 16 show the bolt 56 locked into the bolt extended position with the lock 2 locked in the locked position, and FIGS. 2 , 2 A- 2 C, 17 , and 18 show the bolt 56 in the bolt retracted position with the lock 2 unlocked in the unlocked position. The elongated guide 52 has lock mounting hole 292 therethrough one of the substantially planar side portions 138 , the adjacent one of the oblique angled side portions 289 , the adjacent one of the arcuate sides 286 of the substantially centrally disposed longitudinal channel 54 and the adjacent one of the opposing longitudinally disposed side channel base walls 290 , and through the adjacent one of the longitudinally disposed side channel side walls 291 and the substantially planar opposing side 136 . The lock 2 is mounted in the lock mounting hole 292 .
[0300] The lock 2 comprises lock cylinder 293 , the lock cylinder 293 having an arcuate keyway 294 , arcuate tab 295 having lock stop 296 and unlock stop 297 , head 298 having slot 299 , mounting shoulder 400 , and bearing surface 402 . The lock 2 is rotatably mounted in the lock mounting hole 292 , with the mounting shoulder 400 rotatably mounted about the longitudinally disposed side channel side wall 291 adjacent the lock mounting hole 292 .
[0301] The astragal 30 has longitudinal wall 404 adjacent the edge 42 of the inactive door 44 . The lock 2 is rotatably mounted and held within the locking astragal with self positioning astragal seal 1 between the longitudinal wall 404 and the longitudinally disposed side channel side wall 291 adjacent the lock mounting hole 292 . The bearing surface 402 of the lock 2 is rotatably mounted abuttingly about the longitudinal wall 404 , and the mounting shoulder 400 is rotatably mounted abuttingly about the longitudinally disposed side channel side wall 291 adjacent the lock mounting hole 292 , thus, rotatably holding the lock 2 within the locking astragal with self positioning astragal seal 1 .
[0302] The arcuate tab 295 has a substantially ninety degree arc. The lock stop 296 and the unlock stop 297 are, thus, substantially perpendicular to each other, and thus, the locked position and the unlocked position of the lock 2 are substantially perpendicular to each other. The opposing longitudinally disposed side channel base wall 290 has lock contact area 406 and unlock contact area 408 , each adjacent to and on opposing sided of the lock mounting hole 292 . The lock stop 296 contacts the lock contact area 406 of the opposing longitudinally disposed side channel base wall 290 when the lock 2 is locked, and the unlock stop 297 contacts the unlock contact area 408 of the opposing longitudinally disposed side channel base wall 290 when the lock 2 is unlocked. The slot 299 at the head 298 of the lock 2 is substantially perpendicular to the axis of the bolt 56 , when the lock 2 is locked, the lock 2 is in the locked position and the lock stop 296 contacts the lock contact area 406 of the opposing longitudinally disposed side channel base wall 290 , indicating to a user that the bolt 56 is locked in the bolt extended position. The slot 299 at the head 298 of the lock 2 is substantially parallel to the axis of the bolt 56 , when the lock 2 is unlocked, the lock 2 is in the unlocked position and the unlock stop 297 contacts the unlock contact area 408 of the opposing longitudinally disposed side channel base wall 290 , indicating to the user that the bolt 56 is unlocked and may be moved from the bolt extended position to the bolt retracted position and vice versa, or the bolt 56 may be left in either the bolt extended position or the bolt retracted position, at the user's discretion. The lock 2 may be locked or unlocked by rotating the slot 299 at the head 298 of the lock 2 substantially ninety degrees from either unlocked to locked or substantially ninety degrees from locked to unlocked.
[0303] The lock cylinder 293 has wall 410 , and the bolt 56 has bolt top contact portion 412 and other bolt top portion 414 , the bolt top contact portion 412 being adjacent the wall 410 of the lock cylinder 293 , when the lock 2 is locked. When the lock 2 is locked, the lock 2 is in the locked position and the lock stop 296 contacts the lock contact area 406 of the opposing longitudinally disposed side channel base wall 290 , the bolt top contact portion 412 of the bolt 56 is blocked by the wall 410 of the lock cylinder 293 , which prevents the bolt 56 from moving from the bolt extended position to the bolt retracted position, thus, locking the bolt 56 in the bolt extended position. When the lock 2 is unlocked, the lock 2 is in the unlocked position and the unlock stop 297 contacts the unlock contact area 408 of the opposing longitudinally disposed side channel base wall 290 , the axis of the arcuate keyway 294 is substantially parallel to the axis of the bolt 56 , the bolt 56 is unlocked, and portion 416 of the bolt 56 adjacent the arcuate keyway 294 of the lock 2 may be slidably moved through the arcuate keyway 294 , thus, allowing movement of the bolt 56 from the bolt extended position to the bolt retracted position and vice versa, or the bolt 56 may be left in either the bolt extended position or the bolt retracted position.
[0304] A screwdriver or other suitable tool may be used to lock or unlock the lock 2 , by inserting the screwdriver or other suitable tool into the slot 299 and rotating the head 298 , and, thus, the lock 2 into the locked position or the unlocked position. Other suitable means may alternatively be used to rotate the lock 2 into the locked or unlocked position. The head 298 may, in lieu of or in addition to the slot 299 , which acts as a keyway, alternatively have a socket, a keyway, a protuberance, such as, for example, having a hex head, a knob, such as a knurled knob, or other suitable means adapted to facilitate rotating the lock 2 , in which case an alan wrench, a wrench, other suitable tool, or other suitable means may be used to rotate the lock 2 into the locked or unlocked position.
[0305] The lock 2 is preferably injection molded from an engineered plastic resin that has properties to provide strength, such as an acetal, although metal, such as aluminum or steel, thermoplastics, thermosetting polymers, rubber, or other suitable materials may be used.
[0306] The astragal housing 180 and the elongated guide 52 are preferably of metal, such as aluminum or steel, thermoplastics, thermosetting polymers, rubber, or other suitable material or combination thereof.
[0307] The seal block 12 and the latching member 200 are preferably injection molded from an engineered plastic resin that has properties to provide flexural strength, such as an acetal, although other suitable materials may be used. The end seal 20 and the face seal 156 are preferably of cellular material, such as closed cell neoprene sponge, although other suitable materials may be used.
[0308] FIG. 15 shows the latching member 200 with the lever arm 250 depressed and the latching dog 256 ready to be moved to the retraction hole 260 of the slide plate 208 , which is shown after being moved in FIGS. 17 and 18 . The seal block 12 is also retracted along with the bolt 56 , when the latching dog 256 is moved into the retraction hole 260 , as shown in FIGS. 17 and 18 .
[0309] The active door 162 and the inactive door 44 are “handed” as either right hand, in which the hinges of the active door 162 are on the right side of the active door 162 as viewed from the outside of the door frame 48 and left hand if the hinges of the active door 162 are on the left side of the door frame 48 as viewed from the outside of the door frame 48 . The elongated guide 52 and the self positioning astragal seal 10 may easily be reversed from left hand to right hand, and vice versa, by merely loosening the set screws 148 , removing the elongated guide 52 with the self positioning astragal seal 10 from the longitudinal channel 182 of the astragal housing 180 , and installing the elongated guide 52 with the self positioning astragal seal 10 on the end of the astragal housing 180 opposing that from which it was removed, thus, converting the astragal 30 from one hand to the other.
[0310] FIGS. 20-25 show alternate embodiments of astragals having astragal housings that the self positioning astragal 10 may be used with, although other suitable astragals having other suitable astragal housings may be used.
[0311] FIG. 20 shows an alternate embodiment of an astragal housing 300 , which has a saw-tooth recess 302 to retain finned tail 304 of a typical wrapped foam type weather strip 306 for sealing. The astragal housing 300 also has cavity 308 .
[0312] FIG. 21 shows an alternate embodiment of an astragal housing 310 , which is substantially the same as the astragal housing 300 , except that the astragal housing 310 has thermal break 312 , for installations in climates that experience extremely cold weather, in which the astragal housing 310 is fabricated from an aluminum extrusion, or other suitable material having substantially the same properties, which would otherwise readily lose heat to the outside and result in condensation, and in some cases even the formation of ice. The thermal break 312 is created by filling cavity 308 of the astragal housing 300 with a polyurethane thermal break compound, after which it is de-bridged by milling slot 314 , thus, separating outer and inner portions of the astragal housing 310 and preventing infiltration of the cold.
[0313] FIG. 22 shows an alternate embodiment of an astragal 320 , which may be used for installation on a pair of outwsinging rather than inswinging doors, which has astragal housing 322 , cover 324 that provides overlap, and outer seal 326 , and is used on the active leaf of the pair of out swinging doors. Inner seal 328 is of greater reach as the beveled edge of the active door is reversed, creating a greater gap at its inner edge.
[0314] FIG. 23 shows an alternate embodiment of an astragal 330 , which may be used for installation on a pair of outwsinging rather than inswinging doors, which is substantially the same as the astragal housing 320 , except that the astragal 330 has thermal break 332 .
[0315] FIG. 24 shows an alternate embodiment of an astragal 340 , which may be used for installation on a pair of outwsinging rather than inswinging doors, in which cover element 342 has saw-tooth recess 344 to accommodate finned tail 346 of a wrapped foam weather strip seal 348 . Inner seal 349 is of greater reach as the beveled edge of the active door is reversed, creating a greater gap at the inner edge.
[0316] FIG. 25 shows an alternate embodiment of an astragal 350 , which may be used for installation on a pair of outwsinging rather than inswinging doors, which is substantially the same as the astragal housing 340 , except that the astragal 350 has thermal break 352 .
[0317] FIGS. 26-33 show an alternate embodiment of a locking astragal 500 , which is substantially the same as the locking astragal with self positioning astragal seal 1 , except that the self positioning astragal seal has been removed from the locking astragal 500 . The locking astragal 500 has the lock 2 , as in the locking astragal with self positioning astragal seal 1 .
[0318] The locking astragal 500 has an elongated guide 552 having a substantially centrally disposed longitudinal channel 554 and a bolt 556 slidably mounted therein the substantially centrally disposed longitudinal channel 554 .
[0319] The bolt 556 is retracted to a retracted position, as shown in FIG. 1 , and is released when the bolt 556 is extended to an extended position, as shown in FIG. 27 .
[0320] FIGS. 26 and 26 A- 26 C show the bolt 556 locked into the bolt extended position with the lock 2 locked. FIGS. 27 and 27 A- 27 C show the bolt 556 in the bolt retracted position with the lock 2 unlocked.
[0321] The elongated guide 552 of the astragal 500 has substantially planar side 636 and substantially planar sides 638 , which are substantially parallel to the substantially planar side 636 , and sides 640 , which are substantially perpendicular to the substantially planar sides 638 and the substantially planar side 636 . The elongated guide 552 also has opposing longitudinally disposed side channels 642 . The substantially planar sides 638 and the substantially planar opposing side 636 have threaded holes 644 and 646 , respectively, therethrough, opposing one another, having set screws 648 therein, the set screws 648 extending across the longitudinally disposed side channels 642 .
[0322] The bolt 556 is substantially aligned collinearly with the substantially centrally disposed longitudinal channel 554 .
[0323] The locking astragal 500 has astragal housing 180 , and is mounted to the astragal housing 180 , which is mounted to the edge 42 of the inactive door 44 adjacent the header 164 of the door frame 48 , as shown in FIGS. 32 and 33 .
[0324] The locking astragal 500 may be used adjacent the sill 46 and/or header 164 of the door frame 48 , and may be used with the inactive door 44 and/or the active door 162 . Typical installations, however, have the locking astragal with self positioning astragal seal 1 adjacent the sill 46 and the locking astragal 500 adjacent the header 164 . Top 660 of the locking astragal 500 is shown adjacent the header 164 of the door frame 48 , and the locking astragal with self positioning astragal seal 1 is shown adjacent the sill 46 of the door frame 48 in FIGS. 32 and 33 . The bolt 56 of the locking astragal with self positioning astragal seal 1 locks the locking astragal with self positioning astragal seal 1 to the sill 46 , and the bolt 556 of the locking astragal 500 locks the locking astragal 500 to the header 164 of the door frame 48 , which, thus, locks the inactive door 44 to the door frame 48 .
[0325] The locking astragal 500 may have or be used with the astragal housing 180 , as in the locking astragal with self positioning astragal seal 1 , or the locking astragal 500 may have or be used with an alternate astragal housing. The elongated guide 552 of the locking astragal 500 may be inserted into the longitudinal channel 182 and held in the longitudinal channel 182 by the retention guides 184 and the set screws 648 , and the channel base 185 . The set screws 648 lock the elongated guide 552 into the astragal housing 180 . The locking astragal 500 may, thus, be installed into the longitudinal channel 182 in substantially the same manner as the locking astragal with self positioning astragal seal 1 .
[0326] The locking astragal 500 may also have or be used with the lockset strike 186 and the deadbolt strike 188 mounted to the longitudinal channel 182 of the astragal housing 180 , or an alternative lockset strike and/or an alternative deadbolt strike may be used. The active door 162 may have the lockset 192 and the deadbolt 194 , which may be received by the lockset strike 186 and the deadbolt strike 188 , respectively, on the inactive door 44 , for securing the active door 162 to the inactive door 134 when the active door 162 is closed abuttingly adjacent the inactive door 44 . The astragal housing 180 may have the lockset cover plate 196 and the deadbolt cover plate 198 , which are mounted to the astragal housing 180 , the lockset strike 186 and the deadbolt strike 188 being fastened to the lockset cover plate 196 and the deadbolt cover plate 198 with the screws 199 .
[0327] The locking astragal 500 has the latching member 200 , the pull block 202 , the elongated connector 204 , the compression spring 206 about the elongated connector 204 , and the slide plate 208 , as in the locking astragal with self positioning astragal seal 1 .
[0328] The bolt 556 has lower portion 710 and upper portion 714 , the upper portion 714 of the bolt 556 having substantially the same diameter as the lower portion 710 , and having a slot 716 therethrough and a hole 718 therethrough, the slot 716 and the hole 718 substantially perpendicular one to the other.
[0329] The elongated connector 204 of the locking astragal 500 has the end pin 220 , the opposing hole 222 , and the pin 224 therebetween, the end pin 220 and the pin 224 substantially perpendicular to the plane of the elongated connector 204 , as in the locking astragal with self positioning astragal seal 1 . The elongated connector 204 is sandwiched in the slot 716 of the upper portion 714 of the bolt 556 , the hole 718 and the hole 222 aligned one with the other, the bolt 556 and the elongated connector 204 pinned one to the other with the pin 226 , the pin 226 therethrough the holes 222 and 718 , as in the locking astragal with self positioning astragal seal 1 .
[0330] The pull block 202 of the locking astragal 500 has the longitudinal tracks 228 , the retention tracks 230 and 232 , and the channels 234 and 236 , the channels 234 between the longitudinal tracks 228 and the retention tracks 230 , and the channels 236 between the longitudinal tracks 230 and the retention tracks 232 , as in the locking astragal with self positioning astragal seal 1 . The pull block 202 is inserted into the longitudinal channel 182 of the astragal housing 180 , the channels 234 and 236 being adjacent to the retention guides 184 of the astragal housing 180 , the retention guides 184 slidably retaining the pull block 204 in the astragal housing 180 . The pull block 202 has the substantially centrally disposed notch 238 at the base 240 of the pull block 202 , the notch 242 adjacent and substantially perpendicular to the substantially centrally disposed notch 238 , and the bearing notches 244 . The substantially centrally disposed notch 238 is adjacent to and surrounds the elongated connector 204 adjacent the end pin 220 of the elongated connector 204 ; and the sides 246 of the notch 242 surround and abut the end pin 220 , thus, pinning the elongated connector 204 to the pull block 202 one to the other. The pull block 202 also has the lever arm receiving hole 248 .
[0331] The latching member 200 of the locking astragal 500 has the lever arm 250 , which has the trunnions 252 protruding therefrom, the spring tail 254 , and the latching dog 256 , as in the locking astragal with self positioning astragal seal 1 . The slide plate 208 has the retraction hole 260 , the extension hole 262 , the notches 264 , which form the end tabs 266 , and the projecting tabs 268 , which form the projecting notch 270 therebetween, the projecting notch 270 for matingly slidably receiving the elongated connector 204 therebetween.
[0332] The elongated guide 552 of the locking astragal 500 is locked into the astragal housing 180 with the set screws 648 . The elongated guide 552 has the notched recesses 780 , the notched recesses 780 matingly receiving the end tabs 266 of the slide plate 208 therein, and adjacent ends 782 , the notches 264 of the slide plate 208 matingly receiving the ends 782 of the elongated guide 552 therein, the slide plate 208 being sandwiched and locked between the elongated guide 552 and the channel base 185 of the astragal housing 180 . The projecting notch 270 of the slide plate 208 slidably guides the elongated connector 204 , which is located in the projecting notch 270 , substantially collinear with the center line of the elongated guide 552 .
[0333] The latching member 200 is sandwiched between the pull block 202 and the slide plate 208 , with the trunnions 252 in the bearing notches 244 of the pull block 202 and the lever arm 250 extending through the lever arm receiving hole 248 of the pull block 202 , thus facilitating operator control. The retraction hole 260 and the extension hole 262 of the latching member 200 matingly receive the latching dog 256 of the latching member 200 therein.
[0334] The latching member 200 of the locking astragal 500 may be retracted to a latching member retracted position, when the lever arm 250 of the pull block 202 is depressed and pushed in the direction of pull block arrow marking 284 , which pulls the elongated connector 204 in the direction of the pull block arrow marking 284 , pulls the bolt 556 into the bolt retracted position, and compresses the compression spring 206 between the pin 224 of the elongated connector 204 and the projecting tabs 268 of the slide plate 208 . When the latching member 200 is retracted to the latching member retracted position, the spring tail 254 of the latching member 200 forces the latching dog 256 into the retraction hole 260 of the slide plate 208 , thus, locking the bolt 556 into the bolt retracted position.
[0335] The latching member 200 of the locking astragal 500 may be released into a latching member extended position from the latching member retracted position, when the lever arm 250 of the pull block 202 is depressed and released, releasing compression from the compression spring 206 between the pin 224 of the elongated connector 204 and the projecting tabs 268 of the slide plate 208 , forcing the elongated connector 204 in the direction opposing the pull block arrow marking 284 , forcing the bolt 556 into the bolt extended position. When the latching member 200 is released, the latching member 200 snaps into latching member extended position, the latching dog 256 snaps into the extension hole 262 of the slide plate 208 , the spring tail 254 of the latching member 200 forcing the latching dog 256 into the extension hole 262 , thus, locking the bolt 556 into the bolt extended position. The latching member 200 may alternatively be pushed into the latch member extended position.
[0336] The substantially centrally disposed longitudinal channel 554 of the elongated guide 552 has arcuate sides 786 and arcuate base 788 to slidably and matingly accommodate the bolt 556 , the lower portion 710 and the upper portion 714 of which are substantially cylindrical and have substantially the same diameter. The elongated guide 552 also has oblique angled side portions 789 between the substantially planar side portions 638 and the arcuate sides 786 of the substantially centrally disposed longitudinal channel 554 .
[0337] The longitudinally disposed side channels 642 have base walls 790 , which oppose the arcuate sides 786 of the substantially centrally disposed longitudinal channel 554 , and side walls 791 opposingly adjacent the substantially planar opposing side 636 .
[0338] Again, FIGS. 26 and 26 A- 26 C show the bolt 556 locked into the bolt extended position with the lock 2 locked in the locked position, and FIGS. 27 and 27 A- 27 C show the bolt 556 in the bolt retracted position with the lock 2 unlocked in the unlocked position. The elongated guide 552 has lock mounting hole 792 therethrough one of the substantially planar side portions 638 , the adjacent one of the oblique angled side portions 789 , the adjacent one of the arcuate sides 786 of the substantially centrally disposed longitudinal channel 554 and the adjacent one of the opposing longitudinally disposed side channel base walls 790 , and through the adjacent one of the longitudinally disposed side channel side walls 791 and the substantially planar opposing side 636 . The lock 2 is mounted in the lock mounting hole 792 .
[0339] The lock 2 of the locking astragal 500 comprises lock cylinder 293 , the lock cylinder 293 having an arcuate keyway 294 , arcuate tab 295 having lock stop 296 and unlock stop 297 , head 298 having slot 299 , mounting shoulder 400 , and bearing surface 402 . The lock 2 is rotatably mounted in the lock mounting hole 792 , with the mounting shoulder 400 rotatably mounted about the longitudinally disposed side channel side wall 791 adjacent the lock mounting hole 792 .
[0340] The locking astragal 500 has longitudinal wall 904 adjacent the edge 42 of the inactive door 44 . The lock 2 is rotatably mounted and held within the locking astragal 500 between the longitudinal wall 904 and the longitudinally disposed side channel side wall 791 adjacent the lock mounting hole 792 . The bearing surface 402 of the lock 2 is rotatably mounted abuttingly about the longitudinal wall 904 , and the mounting shoulder 400 is rotatably mounted abuttingly about the longitudinally disposed side channel side wall 791 adjacent the lock mounting hole 792 , thus, rotatably holding the lock 2 within the locking astragal with self positioning astragal seal 1 .
[0341] The arcuate tab 295 has a substantially ninety degree arc. The lock stop 296 and the unlock stop 297 are, thus, substantially perpendicular to each other, and thus, the locked position and the unlocked position of the lock 2 are substantially perpendicular to each other. The opposing longitudinally disposed side channel base wall 790 has lock contact area 906 and unlock contact area 908 , each adjacent to and on opposing sided of the lock mounting hole 792 . The lock stop 296 contacts the lock contact area 906 of the opposing longitudinally disposed side channel base wall 790 when the lock 2 is locked, and the unlock stop 297 contacts the unlock contact area 908 of the opposing longitudinally disposed side channel base wall 790 when the lock 2 is unlocked. The slot 299 at the head 298 of the lock 2 is substantially perpendicular to the axis of the bolt 556 , when the lock 2 is locked, the lock 2 is in the locked position and the lock stop 296 contacts the lock contact area 906 of the opposing longitudinally disposed side channel base wall 790 , indicating to a user that the bolt 556 is locked in the bolt extended position. The slot 299 at the head 298 of the lock 2 is substantially parallel to the axis of the bolt 556 , when the lock 2 is unlocked, the lock 2 is in the unlocked position and the unlock stop 297 contacts the unlock contact area 908 of the opposing longitudinally disposed side channel base wall 790 , indicating to the user that the bolt 556 is unlocked and may be moved from the bolt extended position to the bolt retracted position and vice versa, or the bolt 556 may be left in either the bolt extended position or the bolt retracted position, at the user's discretion. The lock 2 may be locked or unlocked by rotating the slot 299 at the head 298 of the lock 2 substantially ninety degrees from either unlocked to locked or substantially ninety degrees from locked to unlocked.
[0342] The lock cylinder 293 has wall 410 , and the bolt 556 has bolt top contact portion 912 and other bolt top portion 914 , the bolt top contact portion 912 being adjacent the wall 410 of the lock cylinder 293 , when the lock 2 is locked. When the lock 2 is locked, the lock 2 is in the locked position and the lock stop 296 contacts the lock contact area 906 of the opposing longitudinally disposed side channel base wall 790 , the bolt top contact portion 912 of the bolt 556 is blocked by the wall 410 of the lock cylinder 293 , which prevents the bolt 556 from moving from the bolt extended position to the bolt retracted position, thus, locking the bolt 556 in the bolt extended position. When the lock 2 is unlocked, the lock 2 is in the unlocked position and the unlock stop 297 contacts the unlock contact area 908 of the opposing longitudinally disposed side channel base wall 790 , the axis of the arcuate keyway 294 is substantially parallel to the axis of the bolt 556 , the bolt 556 is unlocked, and portion 916 of the bolt 556 adjacent the arcuate keyway 294 of the lock 2 may be slidably moved through the arcuate keyway 294 , thus, allowing movement of the bolt 556 from the bolt extended position to the bolt retracted position and vice versa, or the bolt 556 may be left in either the bolt extended position or the bolt retracted position.
[0343] A screwdriver or other suitable tool may be used to lock or unlock the lock 2 , by inserting the screwdriver or other suitable tool into the slot 299 and rotating the head 298 , and, thus, the lock 2 of the locking astragal 500 into the locked position or the unlocked position. Other suitable means may alternatively be used to rotate the lock 2 into the locked or unlocked position. The head 298 may, in lieu of or in addition to the slot 299 , which acts as a keyway, alternatively have a socket, a keyway, a protuberance, such as, for example, having a hex head, a knob, such as a knurled knob, or other suitable means adapted to facilitate rotating the lock 2 , in which case an alan wrench, a wrench, other suitable tool, or other suitable means may be used to rotate the lock 2 into the locked or unlocked position.
[0344] The lock 2 of the locking astragal 500 is preferably injection molded from an engineered plastic resin that has properties to provide strength, such as an acetal, although metal, such as aluminum or steel, thermoplastics, thermosetting polymers, rubber, or other suitable materials may be used.
[0345] The astragal housing 180 and the elongated guide 552 are preferably of metal, such as aluminum or steel, thermoplastics, thermosetting polymers, rubber, or other suitable material or combination thereof.
[0346] The latching member 200 of the locking astragal 500 is preferably injection molded from an engineered plastic resin that has properties to provide flexural strength, such as an acetal, although other suitable materials may be used.
[0347] The active door 162 and the inactive door 44 are “handed” as either right hand, in which the hinges of the active door 162 are on the right side of the active door 162 as viewed from the outside of the door frame 48 and left hand if the hinges of the active door 162 are on the left side of the door frame 48 as viewed from the outside of the door frame 48 . The elongated guide 552 may easily be reversed from left hand to right hand, and vice versa, by merely loosening the set screws 648 , removing the elongated guide 552 from the longitudinal channel 182 of the astragal housing 180 , and installing the elongated guide 552 on the end of the astragal housing 180 opposing that from which it was removed, thus, converting the locking astragal 500 from one hand to the other.
[0348] The locking astragal 500 may be used adjacent the sill 46 and/or the header 164 of the door frame 48 ; the locking astragal with self positioning astragal seal 1 may be used adjacent the sill 46 and/or the header 164 of the door frame 48 ; the locking astragal 500 and/or the locking astragal with self positioning astragal seal 1 being used adjacent the sill 46 and/or the header 164 of the door frame 48 as required.
[0349] The bolt 556 of the locking astragal 500 may be used without sealing means, alternatively with the self positioning astragal seal 10 and/or alternatively the bolt 556 may use alternative sealing means.
[0350] The elongated guide 552 and the bolt 556 of the locking astragal 500 have been simplified for lower cost, simplicity, and ease of manufacture. Alternatively, a locking astragal can be constructed by simply removing the self positioning astragal seal from the locking astragal with self positioning astragal seal 1 , with the elongated guide 52 and/or the bolt 556 unmodified. Selection and/or use of the elongated guide 552 versus the elongated guide 52 and the bolt 556 versus the bolt 56 may depend on availability of already manufactured components and tooling for new components. The locking astragal 500 and the locking astragal with self positioning astragal seal 1 are constructed with substantially interchangeable parts where possible, in order to keep manufacturing, assembly, and tooling costs to a minimum.
[0351] Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.
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A locking astragal comprising: a bolt having a bolt retracted position and a bolt extended position; a lock having a locked position and an unlocked position, the lock locking the bolt into the bolt extended position when the bolt is in the bolt extended position and the lock is in the locked position, the lock having a wall, which prevents movement of the bolt and locks the bolt into the bolt extended position, when the bolt is in the bolt extended position and the lock is in the locked position; the lock unlocking the bolt when the lock is in the unlocked position, the lock having a keyway, which allows at least a portion of the bolt to pass therethrough when the bolt is unlocked. The locking astragal can be used with a variety of thresholds, sills, headers, doors, and door frames
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BACKGROUND
The present invention relates to a method for automatically depositing objects for transporting the objects. It also relates to a system implementing this method.
The invention relates more particularly to a method and a system capable for example of implementation at places such as airports for the deposit of baggage items by an air transport passenger for the purpose of the transport of the baggage items in an aircraft hold, or places such as post offices for depositing packages to be transported by a postal organization.
The current procedure for depositing a baggage item at airports is carried out:
at a check-in desk where an agent weighs a baggage item and enters its deposit into the data associated with the passenger (PNR), or at a desk for depositing baggage items where the passenger goes after completing his check-in and having printed, or not, a luggage label on paper media, containing a barcode. Such a desk is also attended by at least one agent.
In both cases, an agent inspects the boarding card of the passenger and the number of baggage items deposited and updates the centralized information system of the airline.
This means that the airline must employ a sufficient number of agents in order to attend to the deposit of baggage. This involves a cost for the airline as well as a reduction in customer service. In fact, in many cases the agent performs additional tasks: seat changes, discussion with the passenger, information. These tasks take up time, reduce the efficiency of the agent and result in queues.
Moreover, in most cases, depositing the baggage is carried out at desks which are dedicated to a specific route only. Thus, the number of agents increases according to the number of routes, especially when the departure times of the different routes are close together and the baggage items for several routes must be deposited at the same time.
SUMMARY
A purpose of the present invention is to overcome the above mentioned drawbacks.
A further purpose of the invention is to propose a method and a system making it possible to carry out the depositing of objects with fewer agents and a higher quality of service.
Finally, a further purpose of the invention is to propose a method and a system for depositing objects, capable of use at the same time by several companies for several routes, while reducing the time and space for depositing objects.
The invention proposes to achieve the above-mentioned purposes by a method for automatically depositing objects for the purpose of the transport of said objects, said method comprising:
a depositing phase or step, comprising the following steps:
applying, by a user, a first electromagnetic identification label onto an object to be transported, placing, by said user, said object to be transported on means of conveyance, reading an identification data, by a first reading means, from said first electromagnetic identification tag, and storing said identification data read in storage means in association with previously stored data relating to said transport;
a conveying phase or step for conveying said object for the purpose of its transport.
According to the invention, the objects to be transported are either baggage items to be transported when the invention is applied to automatically depositing baggage items at places such as airports, or packages when the invention is applied to automatically depositing packages at places such as post offices or similar.
Hereinafter, “user” denotes a traveller when the invention is applied to automatically depositing baggage items at places such as airports, or a client of a postal organization when the invention is applied to automatically depositing packages at places such as post offices or similar.
The first identification tag, which is an electromagnetic tag, can be associated with the user, such as for example an RFID tag with a number of a user or frequent traveller.
The first electromagnetic tag can be an identification tag of the RFID (Radio Frequency Identification) type, optionally reusable. The risk of incorrect routing of baggage is thus reduced, as the passenger applies an RFID identification tag, for example a permanent tag, that is more robust and easier to read than the paper label with a barcode currently provided. This results in a substantial reduction in distribution of incorrectly routed baggage items by the airlines and an improvement in customer service.
The method according to the invention makes it possible to dispense with agents for carrying out the depositing phase, during which the object is deposited by the user. The airline or postal organization can thus economize on the salary of the agent present at the location of deposit of objects to be transported.
Moreover, using the method according to the invention, depositing objects for several routes can be carried out at the same time. It is not necessary to provide additional personnel as the users will deposit their baggage items themselves.
For the users, the advantage lies in a significant reduction in the deposit time for objects as queues are avoided: each user spends much less time depositing his object(s) and scalability of systems for depositing objects is facilitated as management of personnel is not required.
For the airport or the post office, the method according to the invention represents a much more efficient use of space, as a space identical to one counter can allow a greater number of users to deposit objects (baggage items or packages). This advantage is even more significant as the system is capable of use in parallel by several companies responsible for transport, which is rarely the case at present.
According to a particular version of the invention, the method according to the invention can comprise, before the phase of conveying said object for the purpose of its transport:
a phase of conveying said object to second reading means; and a processing phase or step, performed out of reach of said user and comprising the following steps:
automatic reading of the identification data from the first electromagnetic identification tag, by said second reading means, writing, on a second identification tag, at least a part of the data relating to said transport associated with said read identification data, and applying said second identification tag onto said object.
Thus, using the method according to the invention, only an unqualified agent is required in order to apply the second identification tag. This second phase can be carried out outside the area that is accessible to the passengers and out of their sight.
Advantageously, the second identification tag can be either an electromagnetic tag, for example RFID, or a barcode label or also a combination of the two. When this second identification tag is an RFID tag, it can be used by the airline or postal organization for other applications for the handling of baggage items or packages using RF (Radiofrequency), such as for example the sorting of baggage items or packages.
The method according to the invention comprises moreover a prior phase of storing the data relating to the transport in storage means, said data comprising:
data relating to the user with whom the object is associated, data relating to the total number of objects ( 306 ) declared by said user, and/or data relating to the destination, the route and the time of the transport.
The advantages of the method according to the invention are increased when the user registers in advance, for example on a terminal provided for this purpose, over the internet or by telephone.
Thus the method according to the invention can comprise an identification of the user with whom the baggage items or packages to be transported are associated, during the depositing phase, before the automatic reading of the first identification tag by the first reading means. The user who has registered in advance is identified by means of an identity document, a secret code or other, and can thus begin to deposit his baggage items or packages onto which he has applied a first electromagnetic identification tag.
The depositing phase can advantageously comprise a measurement of the weight and/or the dimensions of the baggage item and/or storing in storage means of said weight and/or said dimensions in association with the data relating to the transport. This measurement can in particular take place during the reading of the first identification tag by the first reading means. Thus, the weight of the baggage item or package can be checked. If the weight is greater than a maximum weight, the method according to the invention can comprise a display on display means of a notice inviting the passenger or the user to pay a sum of money for the excess weight. The payment can take place either directly in the depositing area, for example using a credit card, or at a desk located in the airport or the post office close to the depositing area.
Advantageously, the storage means can be accessible via an information system of a company responsible for the transport. The storage means can also form part of such a system which can communicate with:
the first and/or the second reading means, the writing means, and optionally, the means of conveyance;
and which can carry out the control of these different means and the management of the exchanges of data between these means.
According to an advantageous feature of the method according to the invention, the depositing phase can comprise a step of taking or reading a biometric data of the user, i.e. the passenger, for example taking a fingerprint, iris imprint, a facial photo. The same biometric data is read or taken during the boarding phase. The biometric data provided during the boarding phase is then compared to the one provided during the depositing phase. This comparison allows a very reliable reconciliation between the person who has deposited a baggage item and the person boarding the flight.
In a particular embodiment, the method according to the invention can be implemented for automatically depositing baggage items at an airport for one or more travel companies.
In another particular embodiment, the method according to the invention can be implemented for automatically depositing packages at a place such as a post office or similar.
According to another aspect of the invention, there is proposed a system for automatically depositing objects for the purpose of the transport of said objects, said system comprising:
first means of reading an identification data from a first electromagnetic identification tag applied by a user onto an object to be transported, storage means, communicating with said first reading means, provided for storing said identification data in association with previously stored data relating to said transport, and means of conveyance provided for conveying said object deposited by said user on said means of conveyance, for the purpose of the transport of said object.
Advantageously, the system according to the invention can moreover comprise:
means of conveying the object, from the first reading means to second reading means, second means of reading the identification data from the first identification tag, said second reading means being arranged out of reach of the user, and means of writing, on a second identification tag, data relating to said transport associated with said identification data read by said second reading means, said second identification tag being provided in order to be applied onto said object.
The writing means can be printing means, in particular printers, advantageously arranged approximately at the level of the second reading means. When the second identification tag is an electromagnetic tag, and more particularly an RFID tag, the writing means can comprise at least one electromagnetic or RFID antenna provided in order to write data into the second RFID tag.
The different means of which the system is composed can communicate with each other and with a centralized information system by means of the use of a management module, which moreover communicates with the centralized information system. Such a module can carry out the control of at least a part of the different means of which the system is composed.
In a particular embodiment, the different means of which the system according to the invention is composed can communicate, at least indirectly, with the centralized information system of the company responsible for the transport which can carry out the control of all or part of these means.
Advantageously, the system according to the invention can moreover comprise means of measuring the weight and/or the dimensions of the object, incorporated into the means of conveying the objects at the level of the first reading means.
In a particular embodiment, the means of conveyance comprise at least one conveyor. The first and the second reading means comprise RFID antennas, arranged on the path of conveyance of the objects. The first reading means are arranged upstream of the second reading means, with respect to the direction of conveyance of the objects.
In a particular embodiment, the RFID antennas can be arranged on mobile supports, flexible or not, arranged substantially perpendicular to the direction of passage of the objects and which:
when idle form a barrier or curtain with respect to the direction of passage of the objects and, on contact with the objects move to a retracted position in order to allow the objects to pass.
According to another particular embodiment, the RFID antennas can also be arranged on a portal that the objects pass through during their conveyance. The system according to the invention comprises at least one first portal on which the first reading means are arranged and, optionally, a second portal on which the second reading means are arranged.
The storage means can communicate with a centralized information system of a company responsible for the transport, i.e. an airline or a postal organization.
The writing means communicate with the second reading means, or the storage means, or both, or also with the centralized information system of the company responsible for the transport. The data to be written are sent to the writing means by the second reading means or the storage means or also by the centralized information system of the company responsible for the transport of the objects.
The system according to the invention can be implemented for automatically depositing baggage items at an airport for the purpose of the air transport of said baggage items or for automatically depositing packages at a post office for the purpose of the transport of said packages.
The system according to the invention can moreover comprise means of reading or taking a biometric data of the user, i.e. the passenger, at the time of depositing baggage items, for example means for taking fingerprints, iris imprints, a facial photo. The installation can comprise in this case means for storing the biometric data taken or read at the time of depositing baggage items in relation to identification data of the user and/or data relating to the baggage items deposited by said user. The system according to the invention can then also comprise means of reading or taking the same biometric data at the time of boarding, and means of comparison of the data taken or read at the time of boarding with the data taken or read at the time of deposit. These means allow a very reliable reconciliation between the person who has deposited a baggage item and the person boarding the flight.
According to another aspect of the invention, there is proposed an installation for automatically depositing objects for the purpose of the transport of said objects, said installation comprising:
a plurality of first reader modules, each comprising first means of reading an identification data from a first electromagnetic identification tag applied by a user onto an object to be transported, storage means, communicating with each of said first reader modules, and provided for storing identification data read by said first reader modules, and means of conveying said object deposited by said user onto said means of conveyance, for the transport of said object.
Advantageously, the installation according to the invention can moreover comprise:
means of conveying the baggage items from the first reader modules to at least one second reader module, at least one second reader module comprising second means of reading the identification data from the first electromagnetic identification tag, at least one module for writing, on a second identification tag, data relating to said transport associated with said identification data read by said second reading means, said second identification tag being provided in order to be applied onto said object.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flowchart showing an example of the sequence of different operations during a depositing phase of a particular version of the method according to the invention implemented for automatically depositing baggage items;
FIG. 2 is a flowchart showing an example of the sequence of different steps during a second phase of a particular version of the method according to the invention implemented for automatically depositing baggage items;
FIG. 3 is a diagrammatic representation of an example of a system according to the invention implemented for automatically depositing baggage items;
FIG. 4 is a diagrammatic representation of an example of a system according to the invention, implemented for automatically depositing baggage items, at the level of the first reading means;
FIG. 5 is a diagrammatic representation of an example of a system according to the invention, implemented for automatically depositing baggage items, at the level of the second reading means; and
FIG. 6 is a diagrammatic representation of an installation according to the invention, implemented for automatically depositing baggage items, at the level of the first reader modules;
DETAILED DESCRIPTION
FIG. 1 shows an example of the progress of the different steps during a depositing phase of a method according to the invention in which a passenger has deposited one or more baggage items.
During step 102 , the passenger registers on a flight and declares the number of baggage items that he wishes to check in. This first step 102 can be carried out in the airport but also remotely, for example during a booking on the website of a travel company, this booking capable for example of being carried out at home or in the office. This step 102 is very important in terms of security, as it makes it possible to verify that a malicious person does not deposit baggage items in place of the passenger. In fact, boarding cards can be printed on normal paper at home, in the office, etc. Thus, there is an easy opportunity for this boarding card to be duplicated. A malicious person, having retrieved a boarding card, could attend in order to deposit a baggage item in place of a passenger. If the genuine passenger has already deposited his baggage, the system will reject this and request the passenger to go to a manual desk in order to verify his identity. If the malicious person has deposited his baggage first, the genuine passenger is blocked and must then go to a desk. After having proved his identity, for example by means of a secret code, the first baggage deposited by the malicious person can be removed and that of the passenger accepted.
Similarly, a passenger who indicated no baggage items at registration but who has changed his mind must go to a manual desk.
Advantageously, the passenger can also register by using a biometric identity document.
After registering and declaring the number of baggage items to be deposited, the passenger attaches a radio frequency (RFID) tag to his baggage in step 104 . This tag can be a tag that is reusable on several flights.
At the airport, during step 106 , the passenger is identified on a system for automatically depositing baggage items according to the invention by presenting for example his boarding card, inserting his frequent traveller card, giving his name, presenting the biometric identity document used for the registration during step 102 . In order to carry out this identification, the system according to the invention can comprise means of reading an identity document, optionally biometric, communicating with the information system of the airline. The system can comprise means of measuring biometric characteristics of the passenger in order to validate the identity of the passenger.
After verification of the identity of the passenger, in step 108 , the system according to the invention communicates with the information system of the airline in order to verifier if the passenger is authorized to deposit baggage items.
If the passenger is not authorized to deposit one or more baggage items, the system invites the passenger to go to a desk attended by an agent in step 110 .
If the passenger is authorized to deposit one or more baggage items, in step 112 the system invites the passenger to place his first baggage item on the means of conveying the baggage item, for example a conveyor, to the first means of reading the RFID tag, namely one or more radiofrequency antennas, for example arranged at the level of a RF reader portal.
In step 114 , the conveyor conveys the baggage item under the RF reader portal. The tag is read by the RF antennas and system and the number of the tag is added to the items of passenger information (PNR) which are stored in the information system of the airline.
If the airline has chosen the “weigh” option, a scale is incorporated into the conveyor at the location where the RF portal is placed. The weight of the baggage item is measured in step 116 and the result of the weighing is added to the PNR together with the number of the RFID tag. The system according to the invention is designed so that the passenger cannot reach his baggage item when it is under the RF tunnel. This means that he cannot falsify the weighing.
If the weight of the baggage item is greater than a limit set by the company, then the system invites the passenger to go to a desk in order to pay the amount covering the excess weight. The system according to the invention can also comprise means for paying this amount on site using automatic payment means, for example by bank card or in cash.
The system comprises moreover means for display and alerting the passenger to the different steps of depositing baggage items. Thus, a green warning light shows if the PNR is correctly updated.
In step 118 , the conveyor conveys the baggage item to the second means of reading the RFID tag.
In step 120 , the system queries the passenger or the information system, in order to determine if another baggage item is to be deposited. If affirmative, the system invites the passenger to deposit the next baggage item, and steps 112 to 120 are repeated for each of the baggage items. Otherwise, a receipt showing the passenger that his baggage item(s) has (have) been registered is issued in step 122 and another passenger can then deposit his baggage items.
FIG. 2 shows an example of the progress of the different steps during a second phase of a method according to the invention during which the baggage items deposited by a passenger are processed by an unqualified agent.
In step 118 , the baggage item is conveyed by the conveyor from the first means of reading the RFID tag to the second means of reading the RFID tag. These second reading means can comprise a portal including one or more antennas and through which the baggage items are conveyed by the conveyor.
In step 200 , the number of the RFID tag is read by the second reading means and sent to the centralized information system of the airline.
In step 202 , the centralized information system of the company determines if the baggage item has been identified. To this end the centralized information system consults the storage means in which the numbers of the RFID tags read by the first reading means are stored.
If the baggage item is not identified by the centralized information system of the company then the baggage item is conveyed, in step 204 , to a service for managing unidentified baggage items.
If the baggage item is identified by the information system, i.e. if the number of the tag is recognized by the centralized information system, the items of information concerning the journey and the passenger which are stored in the storage means, in particular during step 102 , and which are to be printed on the paper luggage label, are sent to printing means during step 206 .
During step 208 , the printing means print the received items of information onto a standard luggage label, for example IATA standard with a barcode.
An agent then collects the printed luggage label and places it on the baggage item that is undergoing processing during step 210 .
After placing the label on the baggage item, the agent causes the forward movement of the baggage item, which then passes into a standard sorting procedure in step 212 . The processed baggage item passes into the baggage sorting system and the following baggage item is then processed according to steps 200 - 212 , which initiates the printing of the associated label.
FIG. 3 is a very diagrammatic representation of a system according to the invention. The system according to the invention comprises first means 300 of reading, by radiofrequency waves 302 , a radiofrequency tag 304 applied onto a baggage item 306 . The first reading means communicate with the centralized information system 308 of the airline. The items of information read by the first reading means 300 , and in particular the number of the RFID tag 304 , are sent to the centralized information system 308 of the company. The centralized information system stores these items of information, in storage means 310 , in association with the items of information relating to the passenger depositing the baggage item 306 , previously identified using means of identification 312 communicating with the centralized information system 308 .
The baggage item is then conveyed from the first reading means 300 to the second reading means 314 using means of conveyance 316 . The second reading means 314 carry out the reading by radiofrequency waves 318 , of the radiofrequency tag 304 of the baggage item 306 . The read items of information, and in particular the number of the RFID tag 304 , are sent to the centralized information system 308 . The latter consults the storage means in order to determine if this baggage item is correctly identified and determines the passenger with whom this baggage item is associated. Then, the centralized information system 308 sends the items of information relating to the journey and to the passenger to the printing means 318 . These printing means 318 print the items of information received onto a standard format paper luggage label 320 that an operator places on the baggage item 306 .
FIG. 4 is a diagrammatic representation of an example of a system according to the invention at the level of the first reading means. As shown, the system according to the invention comprises an interactive module 400 arranged so that the user can be identified before depositing his baggage item(s). This interactive module also makes it possible to guide the user throughout the baggage deposit process and allows information to be provided to the user during the different steps. The module 400 comprises means 404 of displaying different items of information and indicator light means 406 making it possible to indicate to the user if the deposit of a baggage item has been validated or not.
The passenger 402 is identified using all identification means at the level of the interactive module 400 . Once identified, the user places his baggage item 306 , bearing an RFID tag, on the conveyor means, here a conveyor belt 408 . This conveyor belt 408 conveys the baggage item to a first reader module 410 comprising a portal 412 including three series of radiofrequency antennas 300 . The RFID tag is read by the radiofrequency antennas.
The system according to the invention comprises moreover, at the level of the portal, means for the measurement of the weight of the baggage item (not shown) carrying out a measurement of the weight of the baggage item 306 . During the reading of the RFID tag and the measurement of the weight of the baggage item 306 , the latter is out of reach of the passenger 402 so that the passenger 402 cannot falsify the weight of the baggage item 306 .
If all the steps 102 - 122 described above are carried out successfully, a green indicator lights up at the level of the indicator means 406 in order to indicate to the passenger 402 that depositing the baggage item has taken place successfully. The baggage item is then conveyed by a conveyor 414 to the second reading means.
Moreover, the interactive module further comprises means of payment (not shown), for example by payment card or in cash, when the weight of the baggage item 306 is greater than a maximum weight and an additional payment is necessary.
FIG. 5 is a diagrammatic representation of an example of the system according to the invention at the level of the second reading means. As shown, the system according to the invention comprises, at the level of the second reading means, a second reader module 500 comprising a portal 502 including three series of RFID antennas 314 . The baggage items deposited by the passengers are conveyed to this portal by the conveyor. The RFID tag of each of the baggage items is read by the radiofrequency antennas 314 , and the information read are sent to the centralized information system of the company, which sends the items of information relating to the journey and the passenger to a printer 318 which prints these items of information onto a standard luggage label 320 . An agent 504 places the luggage label 320 on the baggage item 306 .
FIG. 6 is a diagrammatic representation of an installation according to the invention at the level of the first reading means. As shown in FIG. 6 , the installation comprises 3 conveyors 408 defining a baggage item deposit line and discharging onto the conveyor 414 . A first reader module, comprising a portal and radiofrequency antennas, is arranged on each of the conveyors 408 . The users 402 place their baggage items on the conveyors 408 . The radiofrequency tag attached to each of the baggage items 306 is read by the corresponding first reader module 410 and the baggage items are conveyed, by each of the conveyors 408 , to the conveyor 414 . The latter conveys the baggage items in the direction indicated by the arrow F to the second reader module, not shown in FIG. 6 .
Moreover, according to the invention, at the time of depositing the baggage, the passenger can provide a biometric data, for example a one-finger or two-finger print, an iris imprint or a facial photo, which is associated with his registration in the centralized information system of the company for example. This biometric information can be temporary or permanent.
An alternative is enrollment of the passenger data in a storage medium, for example a card or passport, containing their biometric information. This storage medium must then be used as an identifier during the depositing of the baggage item. When boarding, the passenger provides the same biometric information as when depositing the baggage item. This information is compared to the items of information stored in the centralized information system. Advantageously, the biometric information is “live”, and not limited to an item of information stored on a medium, for example in order to avoid the case of a stolen storage medium.
Of course, the invention is not limited to the examples that have just been described. It can be implemented for automatically depositing packages at a place such as a post office. Moreover, adjustments can be made to the invention as described above, without exceeding the scope of the invention.
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A method for automatically depositing objects for transport, including a phase of user storing transport data in a storage element, the data relating to: the user associated with the object; the total number of objects declared by the user; the destination, the route and the time of the transport; a depositing phase, including: a user applying a first electromagnetic identification tag onto an object to be transported; placing, by the user, the object to be transported on a conveyance device; reading an identification data, by first reading device, from the first electromagnetic identification tag, storing identification data read in the storage element in association with previously stored transport data; a phase of conveying the object for transport; the depositing phase including a measurement of the weight and/or dimensions of the object and/or storing, in the storage element, of the weight and/or the dimensions in association with the transport data.
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REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application under 37 C.F.R. §1.53(b) of pending prior application Ser. No. 10/675,399, filed Sep. 30, 2003 of Christopher MIDGLEY et al., for SYSTEMS AND METHODS FOR BACKING UP DATA FILES. This Application is also related to U.S. patent application serial No. 09/465,408 (now U.S. Pat. No. 6,625,623), Ser. No. 09/465,411 (now U.S. Pat. No. 6,526,418), Ser. No. 09/465,435 (now U.S. Pat. No. 6,779,003), Ser. No. 09/465,436 (now U.S. Pat. No. 6,847,984), Ser. No. 09/465,485 (now U.S. Pat. No. 6,460,055), Ser. No. 10/152,060 (now U.S. Pat. No. 6,704,755), and Ser. No. 11/743,875 (pending), which is a continuation of U.S. patent application Ser. No. 10/320,762 (abandoned), the contents of which applications are expressly incorporated by reference herein in their entireties.
BACKGROUND
[0002] Some back up systems operate by having the network administrator identify a time of day during which little or no network activity occurs. During this time, a network administrator can allow a backup system and the data files stored on the computer network to be backed-up, file by file, to a long term storage medium, such as a tape backup system. Typically the network administrator will back up once a week, or even once a day, to ensure that the back up files are current. Such a backup process can be a time consuming, labor intensive, and cumbersome. As computer networks generally operate twenty-four hours a day, seven days week, it can be difficult for a system/network administrator to identify a time period during which network resources may be relegated to a back up procedure. Further, increased users and numbers of changes on a regular daily basis diminishes the value of a back up system that operates once a week or once a day. Systems that only generate back up data periodically are thus of a reduced value.
[0003] In some alternate systems, a data server and a backup server can maintain mirrored data files and backup files. For example, in one such system, a data server can execute change requests on data files and transmit the change requests to the backup server, and the backup server can execute the change requests on the corresponding backup files to keep the backup files mirrored to the data files. Such systems may be viewed as lacking efficiency in their use of data processing capacity and data storage capacity, as two copies of all files are generally required.
SUMMARY
[0004] Methods for backing up data files are described. In one embodiment, the methods can include detecting changed locations in one or more data files, storing the contents of the changed locations at a storage time, and associating the stored contents with the storage time, the changed locations, and one or more file identifiers identifying the one or more data files.
[0005] The storage time can be based on an actual time, a time interval, and/or an event.
[0006] In one embodiment, the methods can further include generating a baseline image prior to detecting the changed locations. The baseline image can include one or more of the data files and can be based on a snapshot image, a file image, and/or a volume image.
[0007] Detecting changed locations in the data files can include using one or more data integrity procedures to generate a summary of an image of the data files. The data integrity procedures can include a cyclic redundancy check (CRC) procedure and/or an MD5 message digest procedure.
[0008] Detecting changed locations in the data files can include generating a baseline image of the data files and using a data integrity procedure to generate a summary of the baseline image at a time prior to the storage time, generating a second image of the data files and using the data integrity procedure to generate a summary of the second image thereafter, and determining whether the data files include changed locations based on the baseline summary and the second summary.
[0009] Detecting changed locations can include dynamically detecting the changed locations.
[0010] Storing the contents can include selecting at least one memory to store the contents. The memory can be distinct from a previously selected memory associated with a prior storage time.
[0011] For the described systems and methods, associating can include generating one or more indexes to associate the stored contents, the respective storage times, the respective changed locations, and the respective file identifiers. The indexes can include a first index to the changed locations based on the file identifiers and a second index to the stored contents based on the changed locations.
[0012] In one embodiment, the method can further include iteratively returning to detecting changed locations.
[0013] In one embodiment, the method can further include using the stored contents to create a version of a selected one of the data files.
[0014] For the described systems and methods, using the stored contents to create a version of a selected data file can include querying the indexes to identify stored contents and respective changed locations associated with the selected data file and combining the identified stored contents with data from a baseline image associated with the selected data file. The indexes can be queried for each of the storage times associated with the version based on the file identifier associated with the selected data file.
[0015] Querying the indexes can include determining that the changed locations are the same for two or more different storage times and identifying the stored contents of the changed locations associated with the latest of the different storage times.
[0016] In one embodiment, the methods can further include coalescing data.
[0017] Coalescing data can include coalescing: two or more stored contents associated with the same file identifier and two or more different storage times, the respective changed locations associated with the two or more coalesced contents, and the indexes to associate the coalesced contents, the respective coalesced changed locations, the file identifier, and the latest of the different storage times.
[0018] Coalescing data can also include coalescing: two or more stored contents associated with the same file identifier and the same storage time, the respective changed locations associated with the two or more coalesced contents, and the indexes to associate the coalesced contents, the respective coalesced changed locations, the file identifier, and the same storage time.
[0019] Also described are processor programs for backing up data files. The processor programs can be stored on a processor-readable medium. In one embodiment, the processor programs can include instructions to cause a processor to: detect changed locations in one or more data files, store the contents of the changed locations at a storage time, and associate the stored contents with the storage time, the changed locations, and one or more file identifiers identifying the one or more data files.
[0020] Also described are systems for backing up data files. In one embodiment, the systems can include one or more data files, one or more servers in communication with the data files, where one or more of the servers can be configured to execute change requests on the data files, and one or more agents in communication with the one or more servers, where the one or more agents can be configured to: detect changed locations in the one or more data files, store the contents of the changed locations at a storage time, and associate the stored contents with the storage time, the changed locations, and one or more file identifiers identifying the one or more files.
[0021] These and other features of the described systems and methods can be more fully understood by referring to the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIGS. 1A-1C schematically illustrate an exemplary system for backing up data files;
[0023] FIG. 2 schematically illustrates exemplary operations for a system according to FIGS. 1A-1C ;
[0024] FIGS. 3 and 4 schematically illustrates exemplary delta files and indexes for a system according to FIGS. 1A-1C and 2 ; and,
[0025] FIG. 5 schematically illustrates an exemplary display of a graphical user interface that can facilitate the described systems and methods.
DETAILED DESCRIPTION
[0026] Illustrative embodiments will now be described to provide an overall understanding of the systems and methods described herein. One or more examples of the illustrative embodiments are shown in the drawings. Those of ordinary skill in the art will understand that the systems and methods described herein can be adapted and modified to provide devices, methods, schemes, and systems for other applications, and that other additions and modifications can be made to the systems and methods described herein without departing from the scope of the present disclosure. For example, aspects, components, features, and/or modules of the illustrative embodiments can be combined, separated, interchanged, and/or rearranged to generate other embodiments. Such modifications and variations are included within the scope of the present disclosure.
[0027] Generally, the described systems and methods relate to backing up data files. In embodiments of the described systems and methods, one or more agents can detect changed locations in one or more data files with respect to an image of the data files. The agents can store the contents of the changed locations at a storage time and can generate one or more indexes to associate the stored contents with the storage time, the changed locations, and one or more file identifiers identifying the data files associated with the changed locations. The agents can thus iteratively return to detecting and/or continue to detect changed locations in the data files with respect to the image, at respective times. Based on the image, the stored contents, and the indexes, the agents can recreate one or more versions of one or more of the data files including changed locations at one or more of the storage times.
[0028] FIGS. 1A-1C schematically illustrate an exemplary system for backing up data files. As shown in the embodiment of FIG. 1A , the system 100 can include first and second client data processing devices (“clients”) 110 , 120 , first and second data server data processing devices (“data servers”) 130 , 140 , and first and second backup server digital data processing devices (“backup servers”) 150 , 160 . The first and second data servers 130 , 140 and the first and second backup servers 150 , 160 can be associated with first and second data storage devices 135 , 145 and first and second backup storage devices 155 , 165 , respectively. The data servers 130 , 140 can provide the clients 110 , 120 with access (e.g., read and/or write access) to data files stored on the data storage devices 135 , 145 , respectively, based on requests from the clients 110 , 120 . In some embodiments, the data servers 130 , 140 can maintain different types of data files on the data storage devices 135 , 145 , respectively. For example, in one such embodiment, the data server 130 can maintain email files on the data storage device 135 , and the data server 140 can maintain document files on the data storage device 145 . The clients 110 , 120 can open, close, modify, and/or delete the data files stored on the data storage devices 135 , 145 . The backup servers 150 , 160 can backup changes in the data files stored on the data storage devices 135 , 145 to the backup storage devices 155 , 165 . In some embodiments, the backup servers 150 , 160 and the backup storage devices 155 , 165 can be configured to store backed up data with different terms of data retention. For example, in one such embodiment, the first backup server 150 and the first backup storage device 155 can store data for a relatively short term, while the second backup server 160 and the second backup storage device 165 can store data for a relatively long term. In one such embodiment, the first backup storage device 155 can include one or more magnetic disks, and the second backup storage device 165 can include one or more magnetic tapes. The terms of data retention can be selected by a user (e.g., a system administrator or another entity).
[0029] As shown in FIG. 1A , the clients 110 , 120 , the servers 130 , 140 , 150 , 160 , and the storage devices 135 , 145 , 155 , 165 can exchange data over a data communications network 105 . The data communications network 105 can include one or more network nodes (e.g., the clients 110 , 120 , the data servers 130 , 140 , and the backup servers 150 , 160 ) that can be interconnected by wired and/or wireless communication lines (e.g., public carrier lines, private lines, satellite lines, etc.) that enable the network nodes to communicate. The exchange of data (e.g., messages) between network nodes can be facilitated by network devices (e.g., routers, switches, multiplexers, bridges, and gateways, etc.) that can manipulate and/or route data from an originating node to a server node regardless of dissimilarities in the network topology (e.g., bus, star, or token ring), spatial distance (local, metropolitan, or wide area network), transmission technology (e.g., transfer control protocol/internet protocol (TCP/IP) or Systems Network Architecture), data type (e.g., data, voice, video, or multimedia), nature of connection (e.g., switched, non-switched, dial-up, dedicated, or virtual), and/or physical link (e.g., optical fiber, coaxial cable, twisted pair, or wireless, etc.) between the originating and server nodes. The nodes can include a networking subsystem (e.g., a network interface card) to establish a communications link between the nodes. The communications link interconnecting the nodes can include elements of a data communications network, a point to point connection, a bus, and/or another type of digital data path capable of conveying processor-readable data.
[0030] As will be understood by those of ordinary skill in the art, in some embodiments, one or more nodes of the data communications network 105 can be included in a local area network (“LAN”). For example with reference to FIG. 1A , in one such embodiment, the clients 110 , 120 , the data servers 130 , 140 , the first backup server 150 , the data storage devices 135 , 145 , and the first backup storage device 155 can form or otherwise be included in a LAN. Such a LAN can include a publicly accessible or a private, i.e., non-publicly-accessible, LAN. In such an embodiment, the second backup server 160 and the second backup data storage device 165 can be located remotely from the LAN and can communicate with one or more nodes of the LAN based on schemes known to those of ordinary skill in the art. Alternatively, for example with reference to FIG. 1A , in some embodiments, the clients 110 , 120 , the data servers 130 , 140 , and the data storage devices 135 , 145 can form or otherwise be included in a LAN, and the first and second backup servers 150 , 160 and the associated backup storage devices 155 , 165 can be located remotely from the LAN.
[0031] The described systems and methods are not limited to network-based systems, and can be implemented on stand-alone systems. For example, in some embodiments, the systems and methods described herein can be implemented on a stand-alone system that includes a digital data processing device and a data storage device. The digital data processing device can include features of data servers and backup servers as described herein, and the data storage device can include storage for data files and backed-up data.
[0032] The digital data processing devices 110 , 120 , 130 , 140 , 150 , 160 can include a personal computer, a computer workstation (e.g., Sun, Hewlett-Packard), a laptop computer, a mainframe computer, a server computer, a network-attached storage (NAS) device, a handheld device (e.g., a personal digital assistant, a Pocket Personal Computer (PC), a cellular telephone, etc.), an information appliance, and/or another type of generic or special-purpose, processor-controlled device capable of receiving, processing, and/or transmitting digital data. As will be understood by those of ordinary skill in the art, a processor can refer to the logic circuitry that responds to and processes instructions that drive digital data processing devices and can include, without limitation, a central processing unit, an arithmetic logic unit, an application specific integrated circuit, a task engine, and/or combinations, arrangements, or multiples thereof.
[0033] As shown in FIG. 1A , the storage devices 135 , 145 , 155 , 165 can store data files that can be maintained by the servers 130 , 140 , 150 , 160 , respectively. As used herein, the term data files can be understood to include files having types and formats of data known to those of ordinary skill in the art. For example, the term data files can include application files, data files, executable files, object files, program files, operating system files, registry files, and other types of data files known to those of ordinary skill in the art, with such examples provided for illustration and not limitation. In some embodiments, the term data files can be understood to include one or more portions of data files. For example, in some embodiments, the term data files can be understood to include data objects within data files, such as attachments (e.g., attachments to email files), records (e.g., records in an email file), and data rows and tables (e.g., data rows and tables in a structured query language (SQL) database file), with such examples being provided for illustration and not limitation. The storage devices 135 , 145 , 155 , 165 can include, for example, volatile and/or non-volatile memory and/or storage elements, such as a random access memory (RAM), a hard drive (e.g., an internal or external hard drive), a magnetic disk, a magnetic tape, a compact disk (CD), a digital video disk (DVD), a redundant array of independent disks (RAID), a removable memory device. In some embodiments, the storage devices 135 , 145 , 155 , 165 can include storage devices networked via a network storage topology known to those of ordinary skill in the art, such as, but not limited to, network-attached storage (NAS) and/or storage area networking (SAN) topologies. In some embodiments, such as the embodiment shown in FIG. 1A , the storage devices 135 , 145 , 155 , 165 can be physically separate from the servers 130 , 140 , 150 , 160 , respectively. Alternatively and/or in combination, in some embodiments, one or more of the storage devices 135 , 145 , 155 , 165 can be physically integrated into one or more respective servers 130 , 140 , 150 , 160 . For example, in one such embodiment, storage device 135 can be integrated into server 130 . In some embodiments, one storage device can be associated with two or more servers.
[0034] FIG. 1B schematically illustrates features of an exemplary data server and an associated data storage device. As shown in FIG. 1B , the data server 200 can include a schedule agent 210 , a storage space agent 215 , a status agent 225 , a policy coordinator agent 230 and one or more policies 235 , a command coordinator agent 240 and one or more commands 245 , an index agent 250 , a file system interface 255 , an image agent 260 , and a detecting agent 265 . As used herein, the term agent can refer to one or more software processes executing on the data server 200 , and the term policy can refer to an operation (such as a backup operation, a restore operation, and a coalescence operation) to be performed by the agents of the data server 200 . A policy can include data based on and/or otherwise associated with one or more data files (e.g., a list of the data files affected by the policy) and times of executing the policy. As further described herein, a policy can be generated by a user (e.g., a system administrator or another entity). Although the features of the data server 200 (and the features of the backup server 300 shown in FIG. 1C ) are shown as performing different functions, those of ordinary skill in the art will understand that the features of the data server 200 (and, separately, the features of the backup server 300 ) can be combined or otherwise modified to form different features and should be interpreted in an illustrative and non-limiting manner.
[0035] As shown in the embodiment of FIG. 1B , the data server 200 can be associated with a data storage device 270 that can store one or more data files 275 in a format such as a directory and sub-directory structure, although other formats can be employed. The schedule agent 210 can provide messages including time data that can be used by the policy coordinator agent 230 and/or other agents to initiate one or more actions. For example, as described further herein, in one embodiment, the schedule agent 210 can provide a message to the policy coordinator agent 230 indicating that a time included in a policy 235 for performing an action has been reached. The storage space agent 215 can determine the quantity of available storage space on the data storage device 270 . The status agent 225 can provide status information (e.g., error messages and/or informational messages) to one or more agents of the data server 200 . The policy coordinator agent 230 can manage the policies 235 on the data server 200 and can specify an operation to be executed (e.g., a backup operation, a restore operation, and a coalescence operation). The command coordinator agent 240 can execute an operation specified by the policy coordinator agent 230 . For example, the command coordinator agent 240 can generate commands 245 (e.g., backup, restore, and coalescence commands) for executing an operation specified by the policy coordinator 230 . The index agent 250 can generate one or more indexes to locate backed-up data. For example, in one embodiment, the index agent 250 can generate two indexes for locating backed-up data based on the data files 275 stored on the data storage device 270 . The file system interface 255 can provide an interface to the data files 275 stored on the data storage device 270 . The image agent 260 can generate an image of one or more of the data files 275 stored on the data storage device 270 . The detecting agent 265 can detect changed locations in one or more of the data files 275 stored on the data storage device 270 with respect to an image of the data files. As provided previously herein, the illustrated embodiments are merely exemplary, and accordingly, agents 210 , 225 , 230 , 240 , 250 , 260 , 265 can be combined, separated, and/or rearranged in different embodiments.
[0036] FIG. 1C schematically illustrates features of an exemplary backup server and an associated backup storage device. As shown in FIG. 1C , the backup server 300 can include one or more agents similar to those shown in FIG. 1B . These agents are denoted by reference numerals that differ by increments of 100 with respect to the reference numerals of the agents shown in FIG. 1B . Also, the backup server 300 can include a delta agent 380 and a storage management agent 385 . The delta agent 380 can manage data stored on backup storage device 370 , such as data associated with a backup of the data files stored on data storage device 270 . The storage management agent 385 can provide input and output (e.g., asynchronous input and output) to the backup storage device 370 .
[0037] As will be understood by those of ordinary skill in the art, the described systems and methods are not limited to a particular configuration of clients, data servers, backup servers, and storage devices, and can be implemented on systems different than those shown in FIGS. 1A-1C . For example, the described systems and methods can be implemented on configurations including one or more clients, one or more data servers, one or more data storage devices, one or more backup servers, and one or more backup storage devices. Those of ordinary skill in the art will also understand that the functions of one or more of the features of the data server 200 and backup server 300 can be distributed among two or more features. For example, the functions of the imaging agent 260 of the data server 200 can be distributed between agents residing on the data server 200 and the backup server 300 . Also for example, the functions of the imaging agent 260 of the data server 200 can be distributed among two or more imaging agents associated with different groupings of the data files 275 stored on the data storage device 270 .
[0038] FIG. 2 schematically illustrates a portion of the exemplary system 100 shown in FIGS. 1A-1C . As shown in FIG. 2 , the illustrated portion of the exemplary system 100 can include a data server 400 and an associated data storage device 470 and a backup server 500 and an associated backup storage device 570 . The data server 400 and the backup server 500 can include features similar to those described herein with respect to FIGS. 1A-1C . Some of these features are denoted in FIG. 2 with reference numerals that differ by increments of 100 with respect to the reference numerals of FIGS. 1B and 1C . As will be understood by those of ordinary skill in the art, the data server 400 and the backup server 500 can exchange data based on a client/server model, in which the data server 400 can represent the client portion of the model and the backup server 500 can represent the server portion of the model.
[0039] Exemplary operations for a system according to FIGS. 1A-1C will now be described with reference to FIG. 2 . The operations shown in FIG. 2 can be initiated by one or more agents residing on the data server 400 and/or one or more agents residing on the backup server 500 . Those of ordinary skill in the art will understand that the exemplary operations should be interpreted in an illustrative and non-limiting manner.
[0040] An overview of an exemplary backup operation for a system according to FIGS. 1A-1C will now be provided with reference to FIG. 2 . For purposes of illustration, the exemplary backup operation will be described with respect to initiation by agents residing on the data server 400 . Based on a backup command 445 from a command coordinator agent 440 , the imaging agent 460 can generate a byte-level image 478 of the data files 475 stored on the data storage device 470 . As shown in FIG. 2 , the data storage device 470 can store one or more data files 475 which can include a hierarchical structure, such as the illustrated directory and subdirectory structure. In some embodiments, the byte-level image 478 can be stored on the data storage device 470 . Alternatively and/or in combination, in some embodiments, the byte-level image 478 can be stored on the backup storage device 570 . Substantially contemporaneously with and/or subsequent to generation of the image 478 , the detecting agent 465 can detect, on a byte level, changed locations in the data files 475 with respect to the image 478 . The data server 400 (e.g., the command coordinator agent 440 , the detecting agent 465 , and/or another agent on the data server 400 ) can provide the changed locations to the backup server 500 , and, at a storage time, such as the storage time t 0 shown in FIG. 2 , the delta agent 580 can store the contents of the changed locations in a delta file 590 on the backup storage device 570 . Alternatively and/or in combination, the backup server (e.g., the command coordinator agent 540 , the delta agent 580 , and/or another agent on the backup server 500 ) can retrieve the changed locations from the data server 400 . Substantially contemporaneously with and/or subsequent to generation of the delta file 590 , the index agent 450 and/or 550 can associate the stored contents in the delta file 590 with the storage time t 0 , the changed locations, and one or more file identifiers identifying the data files 475 including the detected changed locations. For example, as shown in FIG. 2 , the index agent 450 and/or 550 can generate a first index 592 to the changed locations based on the file identifiers and a second index 594 to the stored contents based on the changed locations. As shown in the embodiment of FIG. 2 , the first and second indexes 592 , 594 , respectively, can be stored on the backup storage device 570 . Alternatively and/or in combination, the first and second indexes 592 , 594 , respectively can be stored on the data storage device 470 . The detecting agent 465 can iteratively return to detecting and/or continue to detect changed locations in the data files 475 with respect to the image 478 , and the delta agent 580 can generate delta files 590 ′, 590 ″ at subsequent storage times, such as the times t 1 , t 2 shown in FIG. 2 . The index agent 450 and/or 550 can generate first and second indexes associated with the delta files, denoted as 592 ′, 592 ″ and 594 ′, 594 ″, respectively. As described further herein, the image 478 , the delta files 590 , and the associated first and second indexes 592 , 594 can be used to create a version of a data file including changed locations at one or more of the storage times t 0 , t 1 , and t 2 .
[0041] Data included in one or more of the delta files 590 , first indexes 592 , and second indexes 594 can be compressed and/or encrypted based on schemes known to those of ordinary skill in the art.
[0042] Some features of the exemplary backup operation shown in FIG. 2 will now be described. The backup operation can be initiated by a request to backup a data file stored on the data storage device 470 . In some embodiments, a scheduling agent 410 and/or 510 can provide a message indicating that a time or an event (e.g., condition satisfied) included in a backup policy 435 and/or 535 has occurred. A backup policy 435 and/or 535 can include data based on data files for which to detect changed locations (which are referred to herein as “policy data files”) and storage times at which to store the contents of the changed locations. The storage times can be based on times, such as actual times (e.g., times as measured by a clock on a server, such as the data server 400 and/or the backup server 500 ) and time intervals (e.g., periodic time intervals as measured by a clock on a server), and/or events (e.g., events specified by a system administrator or another entity). For purposes of illustration, the policy data files in FIG. 2 are designated as the data files 475 stored on the data storage device 470 . Those of ordinary skill in the art will understand that the policy data files can include one or more of the data files 475 stored on data storage device 470 . Those of ordinary skill in the art will also understand that the described systems and methods can be configured to concurrently execute multiple policies associated with different policy data files.
[0043] Based on a request to backup the policy data files 475 and/or a message from a scheduling agent 410 that a time or an event included in a backup policy 435 has occurred, a policy coordinator agent 430 can determine whether an image for the policy data files already exists, i.e., was previously generated. As used herein, the term image can be understood to include a copy of the policy data files 475 at a previous time. The policy coordinator agent 430 can determine whether the image of the policy data files exists based on schemes known to those of ordinary skill in the art. Based on determining that an image of the policy data files does not exist, the policy coordinator agent 430 can instruct the command coordinator agent 440 to generate an image of the policy data files 475 , and the command coordinator agent 440 can instruct the image agent 460 to generate an image of the policy data files 475 . For example, as shown in the embodiment of FIG. 2 , the image agent 460 can generate an image 478 of the policy data files 475 and store the image 478 on the data storage device 470 .
[0044] The image agent 460 can generate one or more different types of images. In some embodiments, the image agent 460 can generate a snapshot image 478 of the policy data files 475 . As used herein, the term snapshot image 478 can be understood to include the contents of the policy data files 475 and their interrelationships, e.g., the directory and sub-directory structure shown in FIG. 2 . Alternatively and/or in combination, in some embodiments, the image agent 460 can generate one or more file images (e.g., images of one or more of the policy data files 475 ) and/or one or more volume images, as the term volume images is understood by those of ordinary skill in the art. The image agent 460 can generate the image 478 in a transactional safe state of the policy data files 475 . For example, prior to generation of the baseline image 478 , the command coordinator agent 440 can instruct the data server 400 and/or the data storage device 470 to place the policy data files 475 into a transactional safe state. As will be understood by those of ordinary skill in the art, a transactional safe state refers to a state of a data file in which changes to a data file are prohibited at least temporarily. The transactional safe state of the policy data files 475 can be released after generation of the image 478 .
[0045] In some embodiments, the command coordinator agent 440 can command the index agent 450 to use one or more data integrity procedures to generate a summary or digest of the image 478 . The data integrity procedures can be based on one or more of a Cyclic Redundancy Check (CRC) algorithm, the MD5 message digest algorithm, and other digest algorithms known to those of ordinary skill in the art. The index agent 450 can associate the summary with the image 478 and can store the summary in the data storage device 470 . In some embodiments, the index agent 450 can generate a summary of one or more portions of the image 478 . For example, in one such embodiment, the index agent 450 can generate summaries of directories and/or subdirectories included in the image 478 . Also for example, in one such embodiment, the index agent 450 can generate summaries of one or more of the policy data files 475 included in the image 478 .
[0046] In the following discussion, references will be made to baseline images and summaries and second images and summaries. As used herein, the terms “baseline” and “second” can refer to a relative time relationship, in which baseline indicates association with an earlier time, and second indicates association with a later time.
[0047] Based on a baseline image 478 for the policy data files 475 being generated and/or otherwise identified, the policy coordinator agent 430 can instruct the command coordinator agent 440 to backup the policy data files 475 , and the command coordinator agent 440 can instruct the detecting agent 465 to detect changed locations in the policy data files 475 . In some embodiments, the detecting agent 465 can include a file system filter. As will be understood by those of ordinary skill in the art, a file system filter can include a driver that interacts with an operating system via a kernel interface and that can intercept and communicate requests (e.g., input/output request packets (IRPs)) from an operating system to a file system. Alternatively and/or in combination, in some embodiments, the detecting agent 465 can include a file scanning agent. In some embodiments, the detecting agent 465 can include a file system filter and a file scanning agent as part of a redundancy scheme. For example, the detecting agent 465 can detect changes by default with the file system filter and, based on a failure of the file system filter, with the file scanning agent. In some embodiments, the detecting agent 465 can detect changed locations on a byte-level and/or a disk block-level.
[0048] As will be understood by those of ordinary skill in the art, the described systems and methods are not limited to detecting agents 465 that include a file system filter and/or a file scanning agent and can include detecting agents 465 that are configured to detect changes and/or changed locations in data files 475 based on other schemes for accomplishing the same.
[0049] In embodiments in which the detecting agent includes a file system filter, the detecting agent can intercept requests (e.g., write requests) from an operating system of the data server 400 to the policy data files 475 stored on the data storage device 470 . In one such embodiment, the detecting agent 465 can provide messages that describe changes to the policy data files 475 . For example, the detecting agent 465 can provide messages including data based on changed locations in the policy data files 475 . The data can include file identifiers identifying files having changed locations and the byte-level changed locations. The detecting agent 465 can provide the messages dynamically, i.e., substantially contemporaneously with the changes to the policy data files 475 . In embodiments in which the detecting agent 465 includes a file system filter, therefore, the detecting agent 465 can provide the command coordinator agent 440 with file identifiers identifying one or more policy data files 475 having changed locations and the corresponding byte-level changed locations.
[0050] In embodiments in which the detecting agent 465 includes a file scanning agent, the detecting agent 465 can scan the policy data files 475 for changed locations based on commands from the command coordinator agent 440 . In one such embodiment, the image agent 460 can generate a second image of the policy data files 475 , the index agent 450 can generate a second summary of the second image, and the detecting agent 465 can use the second summary and the baseline summary to determine whether the policy data files 475 include changed locations. For example, the detecting agent 465 can compare the second summary with the baseline summary to determine whether one or more of the policy data files 475 includes changed locations. Generally, differences between the baseline summary and the second summary can indicate that one or more of the policy data files 475 includes changed locations. As will be understood by those of ordinary skill in the art, the detecting agent 465 can compare multiple second summaries with multiple corresponding baseline summaries to identify policy data files 475 including changed locations. For example, the detecting agent 465 can compare summaries in a descending hierarchical manner, such as directory summaries, subdirectory summaries, and data file summaries, to identify policy data files 475 including changed locations. Based on identifying one or more policy data files 475 including changed locations, the detecting agent 465 can compare the second images of the policy data files having the changed locations with the corresponding baseline images to identify the changed locations. In embodiments in which the detecting agent 465 includes a scanning agent, therefore, the detecting agent 465 can provide the command coordinator agent 440 with file identifiers identifying one or more policy data files 475 having changed locations and the corresponding byte-level changed locations.
[0051] At a storage time included in the backup policy 435 and/or 535 , such as the storage time t 0 shown in FIG. 2 , the data server 400 (e.g., the detecting agent 465 , the command coordinator agent 440 , and/or another agent on the data server 400 ) can provide to the backup server 500 (e.g., the command coordinator agent 540 , the delta agent 580 , and/or another agent on the backup server 500 ) the contents of the changed locations, and the delta agent 580 can store the contents in a delta file 590 on the backup storage device 570 . Alternatively and/or in combination, the backup server 500 can retrieve from the data server 400 the contents of the changed locations. Generally, the contents of the changed locations detected by the detecting agent 465 can be copied from the policy data files 475 stored on the data storage device 470 to the delta file 590 stored on the backup storage device 570 . The delta agent 580 can store the contents in a delta file 590 that can be uniquely associated with the storage time, i.e., in a memory location that is different than a memory location associated with a different storage time. As shown in FIG. 2 , the index agent 450 and/or 550 can generate the first and second indexes 592 , 594 , respectively, substantially contemporaneously with and/or subsequent to the generation of the delta file 590 .
[0052] In some embodiments, the command coordinator agent 440 and/or 540 can include summaries of the contents of the changed locations in the second indexes 594 . For example, the command coordinator agent 440 and/or 540 can command the index agent 450 and/or 550 to generate summaries of the contents of the changed locations being stored in the delta file 590 . The detecting agent 465 can use the summaries to detect subsequently changed locations in the policy data files 475 based on schemes described herein.
[0053] Substantially contemporaneously with and/or subsequent to the storage time t 0 , the detecting agent 465 can iteratively return to detecting and/or continue to detect changed locations in the policy data files 475 . As shown in FIG. 2 , delta files 590 and associated first and second indexes 592 , 594 can be generated at storage times t 1 and t 2 that are later than the storage time t 0 based on schemes described herein. As previously indicated, a delta file 590 can represent changed locations in the policy data files 475 at a storage time t 1 with respect to the baseline image 478 .
[0054] FIG. 3 schematically illustrates features of exemplary delta files and indexes for a backup operation of a system according to FIGS. 1A-1C and 2 . As shown in FIG. 3 , a first index 600 can include data based on file identifiers 610 for policy data files including changed locations and locations 620 , in a second index 640 , of those changed locations. The locations 620 can be provided in the form of block offsets in the second index 640 . As shown in FIG. 3 , the second index 640 can include data based on the changed locations 650 and locations 660 , in a delta file 670 , of the contents of the changed locations. The locations 660 can be provided in the form of block offsets in the delta file 670 . The delta file 670 can include contents 680 of the changed locations 650 . For purposes of illustration, the delta file 670 includes an explanatory column 690 showing the changed locations 650 and file identifiers 610 associated with the contents 680 .
[0055] In some embodiments, the changed locations 650 and the contents 680 can be grouped consecutively. As shown in the second index 640 , the changed locations 650 can be grouped consecutively based on the file identifier associated with the changed locations 650 . For example, the changed locations 650 a associated with file A 610 a can be grouped consecutively, and the changed locations 650 b associated with file B 610 b can be grouped consecutively. As shown in the delta file 670 , the contents 680 can be grouped consecutively based on the changed locations 650 associated with the contents 680 . For example, the contents 680 a associated with the changed locations 650 a can be grouped consecutively, and the contents 680 b associated with the changed locations 650 b ′ can be grouped consecutively. Although FIG. 3 shows that the changed locations 650 and the contents 680 can be stored consecutively, those of ordinary skill in the art will understand that the described systems and methods are not limited to consecutive storage of the changed locations 650 and/or the contents 680 , and that non-consecutive storage schemes for the changed locations and/or the contents different than those described herein can be used.
[0056] An exemplary restore operation for a system according to FIGS. 1A-1C will now be described with reference to FIG. 2 . For purposes of illustration, the exemplary restore operation will be described with respect to restoring a version of a policy data file 476 by agents residing on the backup server 500 . Those of ordinary skill in the art will understand that the exemplary restore operation should be interpreted in an illustrative and non-limiting manner and that an operation similar to that described herein can be used to restore two or more policy data files.
[0057] The exemplary restore operation shown in FIG. 2 can be triggered by a request to restore a version of the policy data file 476 . In some embodiments, a scheduling agent 410 and/or 510 can provide a message indicating that a time or an event included in a restore policy 435 and/or 535 has been reached. A restore policy 435 and/or 535 can include data based on versions of data files to restore and restore times at which to restore the versions. The restore times can be based on times, such as actual times and time intervals, and/or events.
[0058] Based on a request to restore a version of the data file 476 and/or a message from a scheduling agent 510 , a policy coordinator agent 530 can instruct a command coordinator agent 540 to create the version 600 (e.g., open a new file for the version 600 ), write to the version 600 the baseline image 478 associated with the data file 476 , and determine a delta file range and/or a storage time range for the version 600 . As will be understood by those of ordinary skill in the art, the version 600 of the data file 476 can be associated with a version time, e.g., a past time. Based on the version time, the command coordinator agent 840 can determine the delta file range and/or the storage time range for the version 600 . The storage time range can include storage times that are earlier than and/or substantially equal to the version time, and the delta file range can include delta files associated with times that are earlier than and/or substantially equal to the version time. For example with reference to FIG. 2 , for a version time t 1 ′, where t 2 <t 1 ′<t 1 , the storage time range can include the storage times t 0 and t 1 and the delta file range can include the delta files 590 and 590 ′.
[0059] FIG. 4 shows exemplary delta files and indexes for a restore operation for a system according to FIGS. 1A-1C and 2 . For purposes of illustration, the storage time range for the version 600 of the data file 476 to be restored includes the storage times t 0 , t 1 , and t 2 , the delta file range includes the delta files 790 , 790 ′, and 790 ″, and the file identifier for the data file 476 is “file A.” The command coordinator agent 540 can query the first indexes associated with the delta file range for the version 600 (i.e., the first indexes 792 , 792 ′, 792 ″) to determine whether one or more the first indexes includes the file identifier file A. Based on a first index including a file identifier file A, the command coordinator agent 540 can query the corresponding second index and delta file to identify the changed locations and the contents of the changed locations. As shown in FIG. 4 , the first indexes 792 and 792 ″ include file identifiers for file A, while the first index 792 ′ does not include a file identifier for file A. The first indexes 792 , 792 ″ indicate that changes for file A were stored at storage times t 0 and t 2 , while the first index 792 ′ indicates that changes for file A were not stored at storage time t 0 . Based on the second indexes 794 , 794 ″ and the delta files 790 , 790 ″ corresponding to the first indexes 792 , 792 ″, the command coordinator agent 540 can write to the version 600 the contents of the changed locations for file A. As shown in FIG. 4 , the contents in delta files 790 , 790 ″ can be written to the version 600 . The command coordinator agent 540 can combine the contents of the changed locations with the data from the baseline image previously included in the version 600 (e.g., the command coordinator can overwrite one or more portions of the baseline image with the contents of the changed locations). The backup server 500 (e.g., the command coordinator agent 540 ) can provide the recreated version 600 to the data server 400 (e.g., the command coordinator agent 440 ).
[0060] As previously described, in some embodiments, a version of a data file can be restored based on a backup server 500 (e.g., one or more agents residing on the backup server 500 ) writing backed-up data associated with the version of the data file to a version 600 and providing the recreated version 600 to a data server 400 (e.g., to one or more agents residing on the data server 400 ). Alternatively and/or in combination, in some embodiments, a version of a data file can be restored based on the backup server 500 providing the backed-up data associated with the version of the data file (e.g., backed-up data based on the delta files 590 , first indexes 592 , and/or second indexes 594 associated with the version of the data file) to the data server 400 , and the data server 400 can use the image 478 and the backed-up data to recreate a version 600 of the data file. In such embodiments, the backup server 500 can provide the data server 400 with relevant portions of relevant delta files, first indexes, and second indexes for recreating a version of a data file, and the data server 400 can open the version and write to the version the relevant portions of the backed up data and the image 478 . The data server 400 can combine the relevant portions of the backed up data and the image 478 . For example, the data server 400 can overwrite portions of the image 478 with corresponding portions of more recent backed-up data.
[0061] A version of a data file can be restored to one or more memory locations on one or more servers. For example, in some embodiments, a restored version of a data file can be associated with the same memory location as an original version, and the original version can be moved to and/or otherwise associated with a different memory location. Alternatively and/or in combination, in some embodiments, a restored version of a data file can be associated with one or more different memory locations than an original version. For example, a restored version of a data file can be associated with a different directory than an original version. Also for example, a restored version of a data file can be restored to one or more different storage devices (e.g., different storage devices on a LAN). A restored version of a data file can be associated with a name based on schemes known to those of ordinary skill in the art.
[0062] In one embodiment of the disclosed methods and systems, a coalescing process as provided herein can be employed to simulate a tape rotation scheme where a coalesced file, for example, can be associated with a virtual “tape.” The number of virtual tapes, and hence, associated tape file(s) (e.g., a file derived using coalescence) may vary based on a user selection, administrator configuration, etc., and can depend on, for example, storage capacity, back up time/interval, and other factors. In some embodiments, one or more user interfaces can be provided to provide a tape rotation experience to a user and/or system administrator via the virtual tapes and the associated tape file(s). Access to a file can thus be provided based on an associated tape identity.
[0063] In one example of a virtual tape embodiment, a user and/or system administrator can determine a time t 0 generate a “tape” file, and thus determine a time for coalescence. In some embodiments, this manual determination of the time may override and/or be performed in addition to otherwise scheduled coalescing processes as provided herein. In some embodiments, a user and/or system administrator may be limited to the number of “tape” files, and thus, the creation of a new tape file may overwrite and/or otherwise cause to be inaccessible, the oldest and/or another designated tape file within the limited number of tape files. It can be understood that the aforementioned methods for providing a virtual tape scheme can be employed via one or more user interfaces that can allow the user/system administrator to perform the features as provided herein. For example, the user/system administrator can be provided an interface that may show virtual tape identifiers, associated file identifiers, file information (e.g., time of creation, user ID associated with the creation, storage location, coalescence information, etc.), to allow the user/system administrator to make selections and/or designations as provided herein.
[0064] With continuing reference to FIG. 2 , in some embodiments, the command coordinator agent 540 can process delta files, first indexes, and/or second indexes in a time order. In one embodiment including a reverse time processing order, the command coordinator agent 540 can determine whether changed locations for a file identifier at two or more storage times are the same. For example, the command coordinator agent 540 can determine whether changed locations associated with a file identifier in two or more second indexes are the same. Based on the changed locations being the same, the command coordinator agent 540 can write to the version 600 the stored contents of the changed locations associated with the latest storage time, i.e., the stored contents in the delta file associated with the latest storage time. For example with reference to FIG. 4 , the second indexes 792 and 792 ″ indicate that block 10 of file A changed at storage time t 0 and, later, at storage time t 2 . In some embodiments, the command coordinator agent 540 can write to the version 600 the contents of block 10 from delta file 790 ″ and ignore the contents of block 10 from delta file 790 . Those of ordinary skill in the art will understand that the described systems and methods are not limited to a processing time order of the delta files, first indexes, and second indexes, and that other processing orders and/or schemes can be used within the scope of the present disclosure.
[0065] As previously described herein, in some embodiments, a version of a data file can be restored based on identifying a delta file range associated with the version and querying delta files and first and second indexes associated with the delta file range to identify changed locations and contents of the changed locations for the version. In embodiments in which the detecting agent 465 includes a file system filter, the version can be restored based on the backup server 500 (e.g., one or more agents on the backup server 500 ) providing the relevant backed-up data for the version (e.g., the relevant portions of the relevant delta files and indexes for the delta file range and file identifier associated with the data file) to the data server 400 (e.g., one or more agents on the data server 400 ), and the data server 400 can combine the contents of the backed-up data with the changes detected by the detecting agent 465 at times later than the latest storage time associated with delta file range but earlier than and/or contemporaneous with the version time. For example, with reference to FIG. 2 , for a version time t 1 ′ that occurs between two storage times, e.g., t 2 <t 1 ′<t 1 , the detecting agent 465 can provide changed locations occurring subsequent to the storage time t 1 and earlier than and/or contemporaneous with the version time t 1 ′.
[0066] An exemplary coalescence operation for a system according to FIGS. 1A-1C will now be described with reference to FIG. 2 . For purposes of illustration, the coalescence operation will be described with respect to initiation by agents residing on the backup server 500 . Those of ordinary skill in the art will understand that the exemplary coalescence operation should be interpreted in an illustrative and non-limiting manner and that an operation similar to that described herein can be used to coalesce different types of backed up data, e.g., delta files, first indexes, and/or second indexes.
[0067] The exemplary coalescence operation shown in FIG. 2 can be triggered by a request to coalesce one or more portions of the backed up data stored on the backup storage device 570 . In some embodiments, a scheduling agent 410 and/or 510 can provide a message indicating that a time or an event included in a coalescence policy 435 has been reached. A coalescence policy can identify backed up data to be coalesced and times at which to coalesce the backed up data. The coalescence times can be based on times, such as actual times and time intervals, and/or events. In some embodiments, the events can be based on available storage space. For example, a coalescence operation can be triggered based on an available storage space on the backup storage device 570 dropping below a threshold. Based on a request to coalesce and/or a message from the scheduling agent 510 , the policy coordinator agent 530 can instruct the command coordinator agent 540 to coalesce one or more portions of the backed up data stored on the backup storage device 570 .
[0068] In some embodiments, the command coordinator agent 540 can coalesce stored contents within a single delta file. As previously described, in some embodiments, the detecting agent 465 can include a file system filter that can detect changed locations as the changed locations happen, i.e., substantially contemporaneously with the changed locations. For example, the file system filter can detect changes in the same changed location of a data file at different times between storage times. A delta file can thus include multiple instances of stored contents corresponding to the same changed locations of the same data file. In some embodiments, the command coordinator agent 540 can coalesce, i.e., merge, stored contents in a single delta file that are associated with the same changed locations of a data file, so that the coalesced delta file includes one instance of a changed location of a data file. Also for example, a file system filter can detect portions of consecutive changed locations at different times between storage times. A delta file can thus store contents of consecutive changed locations in a data file at non-consecutive locations. In some embodiments, the command coordinator agent 540 can coalesce, i.e., concatenate, stored contents in a single delta file that are associated with consecutive changed locations for a data file, so that the stored contents in the coalesced delta file are stored consecutively. Based on coalescing the stored contents in the delta file, the command coordinator agent 540 can coalesce the corresponding first and second indexes to associate the coalesced contents in the coalesced delta file with the coalesced changed locations and the coalesced file identifiers.
[0069] Alternatively and/or in combination, in some embodiments, the command coordinator agent 540 can coalesce, i.e., merge, two or more delta files associated with different storage times t 0 generate a coalesced delta file. As shown in FIG. 4 , two or more delta files associated with different storage times can include stored contents associated with the same data files. For example, the delta files 790 and 790 ″ associated with storage times t 0 and t 2 , respectively, both include stored contents associated with file identifier A. A coalesced delta file based on two or more delta files that include the same changed locations for the same file identifier can include the stored contents associated with the latest storage time, i.e., the stored contents in the delta file associated with the latest storage time. For example with reference to FIG. 4 , a coalesced delta file based on the delta files 790 and 790 ″ can include the contents of block 10 for file A stored in delta file 790 ″ (which is associated with the later storage time t 2 ) and not the contents of block 10 for file A stored in delta file 790 (which is associated with the earlier storage time t 0 ). Based on coalescing two or more delta files to generate a coalesced delta file, the command coordinator agent 540 can coalesce the corresponding first and second indexes to associate the coalesced delta file with the coalesced changed locations and the coalesced file identifiers.
[0070] As previously described, the command coordinator agent 540 can coalesce, i.e., merge, two or more delta files to generate a coalesced delta file based on opening a coalesced delta file, coalescing the delta files, and writing and/or otherwise providing the coalesced data to the coalesced delta file. In some embodiments, the command coordinator agent 540 can coalesce, i.e., merge, two or more delta files based on breaking the delta files into two or more portions and iteratively coalescing the portions. For example, in one such embodiment, the command coordinator agent 540 can separate, partition, and/or otherwise divide the delta files into portions, coalesce one of the portions, write and/or otherwise provide the coalesced portion to the coalesced file, delete the portion, and iteratively return to coalescing the remaining portions. Iteratively coalescing portions of the delta files can reduce data storage capacity for coalescence. In embodiments in which portions of delta files are iteratively coalesced, indexes corresponding to the coalesced delta files can be updated based on the status of the coalesced portions. For example, the indexes can be updated to refer to the locations of the portions of the delta files and, based on coalescing the portions, updated to refer to the coalesced delta file.
[0071] As previously described, in some embodiments, the backup servers 150 , 160 of the exemplary system 100 shown in FIG. 1A can be configured to store backed up data with different terms of data retention. In such embodiments, the first backup server 150 can be configured to store data for a relatively short term, and the second backup server 160 can be configured to store data for a relatively long term. For example, the first backup server 150 can be configured to store data for one or more days, weeks, or months, and the second backup server 160 can be configured to store data for one or more years. In some embodiments, the first backup server 150 can backup the data files maintained by the data server 130 and/or 140 based on a backup period and can provide the backed up data to the second server 160 based on a data retention period that is greater than the backup period. Alternatively and/or in combination, in some embodiments, the first backup server 150 can coalesce the backed up data based on a coalescence period that is greater than the backup period and can provide the coalesced data to the second server 160 . In one such embodiment, the backup period can be one day, the coalescence period can be one week, and the retention period can be one month. In such an embodiment, the first backup server 150 can maintain as many as three weekly-coalesced delta files and seven daily delta files associated with a backup policy, and the backup server 160 can maintain as many as fifty-two weekly-coalesced delta files associated with the same backup policy. Alternatively and/or in combination, in some embodiments, the second server 160 can coalesce the backed up data provided by the first data server 150 .
[0072] As will be understood by those of ordinary skill in the art, the described systems and methods are not limited to using two backup servers 150 , 160 that are associated with different terms of data retention. For example, in some embodiments, the backup servers 150 , 160 can be configured to separately backup data files maintained by the first and second data servers 130 , 140 , respectively.
[0073] Using first and second indexes to associate stored contents with storage times, changed locations, and file identifiers can facilitate recreating versions of data files. As previously described with respect to FIG. 2 , the backup server 500 (e.g., one or more agents residing on the backup server 500 ) can store delta files 590 and indexes 592 , 594 on the backup storage device 570 . In some embodiments, copies of the indexes 592 , 594 can also be stored on the data storage device 470 . In one such embodiment, the data server 400 can facilitate a request to recreate a version of a selected data file by using the indexes 592 , 594 to determine a storage time range for the version. Based on the storage time range and the file identifier for the selected data file, the data server 400 can query the indexes 592 , 594 to identify the changed locations for the selected data file and the locations of the corresponding stored contents in delta files associated with the indexes 592 , 594 . Based on processing the indexes 592 , 594 , the data server 400 can generate a request for the relevant portions of the relevant delta files from the backup server 500 , and the backup server 500 can provide the relevant portions of the relevant delta files to the data server 400 .
[0074] Using first and second indexes to associate stored contents with storage times, changed locations, and file identifiers can also facilitate recreating data files based on backed up data maintained by a relatively long-term data storage device. As previously described with respect to FIG. 1A , the first backup server 150 and the first backup storage device 155 can be configured to store data for a relatively short term, and the second backup server 160 and the second backup storage device 165 can be configured to store data for a relatively long term. In some embodiments, the first backup storage device 155 can be based on magnetic disk, and the second backup storage device 165 can be based on magnetic tape. Based on the schemes previously described, a requesting server (e.g., the data server 130 , 140 and/or the first backup server 150 ) can generate a request for relevant portions of relevant delta files from the second backup server 160 , and the second backup server 160 can provide the relevant portions of the relevant delta files to the requesting server.
[0075] In some embodiments, backup server 150 , 160 can access both of the data storage devices 155 , 165 associated with different terms of data retention. For example, in some embodiments, backup server 150 can be configured to access backup storage device 155 (e.g., relatively short term data storage) and backup storage device 165 (e.g., relatively long term data storage). Alternatively and/or in combination, in some embodiments, backup server 150 can access a single data storage device having a data storage capacity allocated between relatively short term data storage and relatively long term data storage.
[0076] The described restore and coalescence operations can provide backed up data to one or more servers. For example, in some embodiments, the restore and/or coalescence operation can transmit backed up data to one or more data servers (e.g., a data server from which a request to restore a data file originated) and/or one or more backup servers (e.g., a short term backup server and/or a long term backup server) connected to and/or otherwise in communications with one or more data communications networks.
[0077] As previously described herein, data associated with a version of a data file can be stored on one or more servers, such as one or more data servers 400 (e.g., in an image 478 ) and/or one or more backup servers 500 (e.g., in one or more delta files 590 and first and second indexes 592 , 594 ). In some embodiments, the described systems and methods can restore a version of a data file based on a pre-determined spatial hierarchy. In one such spatial hierarchy, a request to restore a version of a data file can be fulfilled based on accessing storage devices in a local-to-remote order. As used herein, the term local can be interpreted to include nodes that are included in a LAN, and the term remote can be interpreted to nodes that are not included in the LAN. For example, based on receiving a request from a client to restore a version of a data file, a data server can first determine whether one or more images stored on local storage devices include data sufficient to recreate the version. Based on locally stored images not being sufficient to recreate the version, the data server can communicate the request to one or more other local servers (e.g., local backup servers capable of accessing relatively short-term backed up data) and then directly and/or indirectly to one or more remote servers (e.g., remote backup servers capable of accessing relatively long-term backed up data).
[0078] As previously described, a user can interact with the clients 110 , 120 , the data servers 130 , 140 , and/or the backup servers 150 , 160 to determine and/or otherwise select one or more policies (e.g., backup policies, restore policies, and coalescence policies 235 , 335 , 435 , 535 shown in FIGS. 1B, 1C , and 2 ), one or more data retention terms (e.g., data retention terms for the first and second backup servers 150 , 160 shown in FIG. 1 ), and/or other parameters of interest. The user can include a system administrator and/or another entity.
[0079] A local user can interact with the clients 110 , 120 by, for example, viewing a command line, using a graphical and/or other user interface, and entering commands via an input device, such as a mouse, a keyboard, a touch sensitive screen, a track ball, a keypad, etc. The user interface can be generated by a graphics subsystem of the client 110 , 120 , which renders the interface into an on- or off-screen surface (e.g., on a display device and/or in a video memory). Inputs from the local user can be received via an input/output ( 0 /) subsystem and routed to a processor via an internal bus (e.g., a system bus) for execution under the control of an operating system of the client 110 , 120 .
[0080] Similarly, a remote user can interact with the clients 110 , 120 over the data communications network 105 . The inputs from the remote user an be received and processed in whole or in part by a remote digital data processing device collocated with the remote user. Alternatively and/or in combination, the inputs can be transmitted back to and processed by a local client 110 , 120 or to another digital data processing device via one or more networks using, for example, thin client technology. The user interface of the local client 110 , 120 can also be reproduced, in whole or in part, at the remote digital data processing device collocated with the remote user by transmitting graphics information to the remote device and instructing the graphics subsystem of the remote device to render and display at least part of the interface to the remote user.
[0081] In one illustrative operation, a graphics subsystem of the client 110 , 120 can render and display a graphical user interface (including, for example, one or more menus, windows, and/or other visual objects) on a display device associated with the client 110 , 120 that can support the definition of one or more policies, one or more data retention terms, and/or other parameters of interest.
[0082] An illustrative display of a graphical user interface that can facilitate a definition of a backup policy will now be described. Those of ordinary skill in the art will understand that the display should be interpreted in an exemplary manner and that displays different than that described herein can be used within the scope of the present disclosure. For example, aspects, components, features, and/or modules of the illustrative display can be combined, separated, interchanged, and/or rearranged to generate other displays.
[0083] FIG. 5 shows an exemplary backup policy window 800 that can be used by a user (e.g., a system administrator and/or another entity) to determine a backup policy. As shown in FIG. 5A , the backup policy window 800 can include a data file selection region 810 and a storage time selection region 820 .
[0084] The data file selection region 810 can include one or more features (e.g., pull-down menus, radio buttons, selectors, and/or fill-in boxes) for selecting files to be backed up. For example, as shown in FIG. 5 , the data file selection region 810 can include radio buttons 820 for selecting files to be backed up, such as all data files or data files of a specific type (e.g., operating system files), and a display 830 of data based on the data files maintained by a data server, such as data server 130 . The display 830 can present data based on the directories, subdirectories, and other file structures maintained by the data server 130 on data storage device 135 . For example, as shown in FIG. 5 , the display 830 presents a data structure 835 having data files arranged in a directory and subdirectory structure. A user may select one or more data files to be backed up by, for example, selecting the files with a mouse click, drawing a box around the files, etc. For example, data files included in the box 840 represent data files selected by a user for backup and association with a backup policy. Unselected files can be excluded from backup and/or can be associated with different backup policies.
[0085] The storage time selection region 850 can include one or more features (e.g., pull-down menus, radio buttons, selectors, and/or fill-in boxes) for determining the storage times for the data files selected in box 840 . For example, as shown in FIG. 5 , the storage time selection region 850 can provide selectors 860 and pull-down menus 865 associated with different storage times, such as continuous storage times (which can be understood to refer to backup of the data files 840 substantially contemporaneously with changed locations to the data files 840 ), periodic storage times (e.g., daily and weekly as shown in FIG. 5 ), and custom storage times 870 (e.g., daily on Monday-Friday at 6:00 AM and daily on Saturday-Sunday at 8:00 AM).
[0086] As will be understood by those of ordinary skill in the art, displays similar to those shown in FIG. 5 can be provided to allow a user to determine and/or otherwise select other parameters of interest, e.g., a restore policy, a coalescence policy, and a data retention term. For example, for a restore policy, a user can select one or more versions of one or more data files to be restored, one or more locations to which to restore the versions, and one or more times corresponding to the versions, i.e., past times; for a coalescence policy, a user can select a storage time range of delta files to be coalesced and/or a storage capacity threshold for initiating a coalescence; and, for a data retention term, a user can select a time interval for retaining backed up data.
[0087] The systems and methods described herein are not limited to a hardware or software configuration; they can find applicability in many computing or processing environments. The systems and methods can be implemented in hardware or software, or in a combination of hardware and software. The systems and methods can be implemented in one or more computer programs, in which a computer program can be understood to comprise one or more processor-executable instructions. The computer programs can execute on one or more programmable processors, and can be stored on one or more storage media readable by the processor, comprising volatile and non-volatile memory and/or storage elements.
[0088] The computer programs can be implemented in high level procedural or object oriented programming language to communicate with a computer system. The computer programs can also be implemented in assembly or machine language. The language can be compiled or interpreted. The computer programs can be stored on a storage medium or a device (e.g., compact disk (CD), digital video disk (DVD), magnetic disk, internal hard drive, external hard drive, random access memory (RAM), redundant array of independent disks (RAID), or removable memory device) that is readable by a general or special purpose programmable computer for configuring and operating the computer when the storage medium or device is read by the computer to perform the methods described herein.
[0089] References to a network, unless provided otherwise, can include one or more intranets and/or the Internet. References herein to microprocessor instructions or microprocessor-executable instructions, in accordance with the above, can be understood to include programmable hardware.
[0090] References to “a microprocessor” and “a processor”, or “the microprocessor” and “the processor,” can be understood to include one or more microprocessors that can communicate in a stand-alone and/or a distributed environment(s), and can thus can be configured to communicate via wired or wireless communications with other processors, where such one or more processor can be configured to operate on one or more processor-controlled devices that can be similar or different devices. Use of such “microprocessor” or “processor” terminology can thus also be understood to include a central processing unit, an arithmetic logic unit, an application-specific integrated circuit (IC), and/or a task engine, with such examples provided for illustration and not limitation.
[0091] Furthermore, references to memory, unless otherwise specified, can include one or more processor-readable and accessible memory elements and/or components that can be internal to the processor-controlled device, external to the processor-controlled device, and/or can be accessed via a wired or wireless network using a variety of communications protocols, and unless otherwise specified, can be arranged to include a combination of external and internal memory devices, where such memory can be contiguous and/or partitioned based on the application. Accordingly, references to a database can be understood to include one or more memory associations, where such references can include commercially available database products (e.g., SQL, Informix, Oracle) and also proprietary databases, and may also include other structures for associating memory such as links, queues, graphs, trees, with such structures provided for illustration and not limitation.
[0092] Unless otherwise stated, use of the word “substantially” can be construed to include a precise relationship, condition, arrangement, orientation, and/or other characteristic, and deviations thereof as understood by one of ordinary skill in the art, to the extent that such deviations do not materially affect the disclosed methods and systems.
[0093] Throughout the entirety of the present disclosure, use of the articles “a” or “an” to modify a noun can be understood to be used for convenience and to include one, or more than one of the modified noun, unless otherwise specifically stated.
[0094] Elements, components, modules, and/or parts thereof that are described and/or otherwise portrayed through the figures to communicate with, be associated with, and/or be based on, something else, can be understood to so communicate, be associated with, and or be based on in a direct and/or indirect manner, unless otherwise stipulated herein.
[0095] While the systems and methods described herein have been shown and described with reference to the shown embodiments, those of ordinary skill in the art will recognize or be able to ascertain many equivalents to the embodiments described herein by using no more than routine experimentation. Such equivalents are intended to be encompassed by the scope of the present disclosure and the appended claims. Accordingly, the systems and methods described herein are not to be limited to the embodiments described herein, can comprise practices other than those described, and are to be interpreted as broadly as allowed under prevailing law.
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Disclosed are systems and methods for maintaining, in a storage system having a source storage system and target storage system, information from which a set of source data files stored on a storage system can be retrieved. In one embodiment, the method comprises storing baseline images of one or more source data files in target files of the target storage system. For a selected target storage time, locations in the source storage system where changes have been made since a previous target storage time are dynamically identified. Contents that occupy the locations are read and sent to the target storage system. The contents are stored in the target storage system together with associations of the contents with the locations.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the manufacture of a compound semiconductor single crystal and, more particularly, to a method and apparatus for manufacturing a compound semiconductor single crystal capable of growing a single crystal having a uniform carrier concentration.
2. Description of the Related Art
In recent years, compound semiconductor single crystals such as GaAs, GaP, InP, and the like are used as substrate materials of various semiconductor devices. These single crystals are manufactured by the Czochralski method, the Bridgman method, and the like. In these methods, if a semiconductor single crystal is manufactured by growing a single crystal from a raw melt, oxygen, carbon, and the like remain in the resultant single crystal as residual impurities. These impurities are produced from graphite normally used as a material for a heater or other furnace members, and are mixed in the raw melt through an atmosphere.
Oxygen, carbon, and the like as the residual impurities in the single crystal normally exhibit a change in concentration along the growth direction of the single crystal, and the change in concentration adversely influences electrical characteristics of a semiconductor single crystal and causes the following disadvantages.
First, desired electrical characteristics are obtained by doping a certain impurity in the single crystal. The electrical characteristics are influenced by the change in concentration of the residual impurity along the growth direction of the single crystal, as described above. Therefore, it is difficult to control the electrical characteristics to be uniform throughout one single crystal ingot. Therefore, the desired electrical characteristics can be obtained from only a limited portion of the single crystal ingot, resulting in very low product yield.
Second, when a semi-insulating GaAs single crystal is manufactured by a liquid encapsulated Czochralski method (LEC method), a carbon concentration in the resultant single crystal ingot tends to be high in a head portion of the ingot and be lowered toward the tail portion. Therefore, when a semiconductor device is manufactured using a substrate prepared from the head portion of the ingot having a large carbon content, the resistance of the substrate is decreased during a heat-treatment process, and a desired semiconductor device cannot be obtained. If the carbon concentration is too low, a semi-insulating property is often already lost and a resistance becomes low when the single crystal is manufactured.
A GaAs single crystal of the compound semiconductor single crystals is widely used as a substrate material for a variety of semiconductor devices, such as a light-emitting device, e.g., a light-emitting diode, a semiconductor laser or the like, a high frequency field effect transistor, a Hall device, and the like. When the GaAs single crystal is used as the substrate material of the light-emitting device, a high-concentration n-type GaAs single crystal is normally used. Recently, a technique of fabricating a light-emitting device on a p-type GaAs single crystal substrate of a high carrier concentration (10 17 to 10 20 /cm 3 ) has been developed, and a p-type GaAs single crystal has also become popular. As an impurity for the p-type GaAs single crystal, zinc is normally used. However, since the zinc is solid, it must be doped in a raw melt. In addition, since the zinc has a segregation coefficient of about 0.3 with respect to GaAs, the carrier concentration of the head portion of the growth of the single crystal ingot is ten times or more of that of the tall portion. Since the boiling point of the zinc is as low as 906° C., it is very difficult to dope the zinc with high controllability.
In a field effect transistor, element isolation becomes difficult to achieve along with further micropatterning of devices. For this reason, a method of producing a device using a p-type GaAs single crystal substrate of a low carrier concentration (10 14 to 10 17 /cm 3 ) is proposed. However, the substrate for the field effect transistor has a very strict specification as compared to that of a light-emitting device. As described above, a zinc-doped p-type GaAs single crystal has low reproducibility of a carrier concentration among crystal ingots, and a carrier concentration is also largely varied in one crystal ingot due to its segregation coefficient. For this reason, it is very difficult to obtain a p-type GaAs single crystal for a substrate of the field effect transistor.
As described above, a p-type GaAs single crystal with a controlled carrier concentration is demanded. However, as long as zinc is used as a dopant, it is very difficult to control a carrier concentration to be uniform not only among a plurality of crystal ingots but even in one crystal ingot.
In consideration of the above situation, the present inventors examined various impurities as a p-type impurity in to replace zinc. It has been found that carbon can be used as a p-type impurity, and that carbon can be doped in a gas state, e.g., CO or CO 2 .
If an apparatus as a combination of a conventional GaAs single crystal pull device and a carbon supplying system is used, a p-type GaAs single crystal can be obtained. However, the carbon concentration of the resultant single crystal cannot be controlled to a desired value. Furthermore, even if a supply amount of a gas as a carbon source is controlled to be constant, it is difficult to maintain the carrier concentration of the resultant GaAs single crystal to be constant.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method of manufacturing a compound semiconductor single crystal capable of controlling a carrier concentration to be uniform.
It is another object of the present invention to provide an apparatus used for the manufacturing method.
According to the present invention, there is provided a method of manufacturing a compound semiconductor single crystal, comprising the steps of: placing a container containing a raw melt in an atmosphere containing at least one monitor gas selected from the group consisting of hydrogen, oxygen, carbon monoxide, and carbon dioxide; detecting a concentration of the monitor gas in the atmosphere; and controlling the detected concentration of the monitor gas to be a preset value.
In the method of the present invention, the monitor gas can be supplied in a chamber housing the container together with a dilution gas, and can be exhausted therefrom together with the dilution gas. In this case, control of the monitor gas concentration can be performed by controlling supply of the monitor gas and/or dilution gas into the chamber, and/or exhaust of the monitor gas and dilution gas from the chamber. Such control can be made by adjusting the degree of opening of valves attached to monitor and dilution gas supply pipes and to monitor and dilution gas exhaust pipes.
The preset value to which the concentration of the monitor gas is controlled can be a value which is set according to a pull weight of a single crystal and is normally a constant value.
A compound semiconductor single crystal obtained by the method of the present invention includes a group III-V compound semiconductor single crystal. The group III-V compound semiconductor includes GaAs, GaP, InP, and the like.
An n-type GaAs single crystal can be obtained from a GaAs raw melt containing an n-type impurity. As the n-type impurity, silicon can be used.
A p-type GaAs single crystal can be obtained from a GaAs raw melt containing a p-type impurity. As the p-type impurity, carbon can be used.
Furthermore, according to the present invention, there is provided an apparatus for manufacturing a compound semiconductor single crystal, comprising: a crystal growth chamber; a container, placed in the chamber, for containing a compound semiconductor raw material; heating means for heating and melting the compound semiconductor raw material in the container; means for growing a compound semiconductor single crystal from a raw melt obtained by heating and melting the compound semiconductor raw material; means for supplying at least one monitor gas selected from the group consisting of hydrogen, oxygen, carbon monoxide, and carbon dioxide into the chamber; means for detecting a concentration of the monitor gas in the chamber; and means for comparing the detected concentration of the monitor gas with a preset concentration of the monitor gas to control the concentration of the monitor gas in the chamber.
When a graphite heating element is used as the heating means, the heating element serves as a carbon source, and a CO or CO 2 concentration in an atmosphere is varied. Therefore, control of the gas concentration is particularly necessary. Control of the gas concentration can be made by adjusting the degrees of opening of valves attached to monitor and dilution gas supply pipes and to monitor and dilution gas exhaust pipes based on an instruction from a computer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing a GaAs single crystal manufacturing apparatus according to an embodiment of the present invention;
FIG. 2 is a graph showing the relationship between a carbon concentration in an atmosphere and a carrier concentration in a manufactured GaAs single crystal;
FIG. 3 is a graph showing a carrier concentration at respective positions of a wafer obtained from a GaAs single crystal ingot according to the embodiment of the present invention;
FIG. 4 is a graph showing a carrier concentration at respective positions in the longitudinal direction of the GaAs single crystal ingot obtained according to the embodiment of the present invention;
FIG. 5 is a view showing a surface of a wafer obtained from the GaAs single crystal ingot according to the embodiment of the present invention;
FIG. 6 is a view showing a longitudinal direction of the GaAs single crystal ingot obtained according to the embodiment of the present invention; and
FIG. 7 is a view showing a GaAs single crystal manufacturing apparatus according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A single crystal in which a residual impurity is maintained to be a constant value throughout an entire ingot can be obtained according to the method of the present invention for the following reason.
When a compound semiconductor single crystal is grown from a raw melt, the concentration of an impurity mixed in the single crystal is uniquely determined by the impurity concentration and a segregation coefficient when no impurity exchange is present between the raw melt and the atmosphere, or by a solidification rate of the single crystal when the growth condition of the single crystal is uniform.
However, the present inventors found that if oxygen, carbon monoxide and the like are present in the atmosphere around the raw melt, these impurities are mixed in the raw melt. The present inventors also found contents of that oxygen, carbon monoxide, and the like in the atmosphere are increased along with the time elapse (as the crystal is grown). When a compound semiconductor single crystal is manufactured by the LEC method or the like, exchange of carbon is complex. For example, mixing in of carbon from carbon monoxide is suppressed due to the presence of a liquid sealant (B 2 O 3 ), carbon in the raw melt is bettered by B 2 O 3 , and such exchange of carbon is changed according to a hydrogen concentration in the atmosphere, and so on.
As described above, oxygen or carbon (carbon monoxide) is exchanged between the raw melt and the atmosphere (in the LEC method, through a liquid sealant layer). Therefore, the concentration of oxygen or carbon monoxide in the atmosphere is detected, and is controlled to be constant in a predetermined period of time (time wherein a crystal is grown to a predetermined length), so that mixing in of oxygen or carbon into a compound semiconductor single crystal can be maintained constant throughout the entire single crystal ingot.
When a p-type GaAs single crystal is manufactured, carbon can be used as a p-type impurity. Unlike zinc, carbon is a typical element, and is a very stable element in a GaAs single crystal. For this reason, as compared to a case wherein zinc is used as a p-type impurity, a very stable p-type GaAs single crystal can be obtained. When CO or CO 2 gas is used as a carbon source and the concentration of the gas in the atmosphere is controlled to be constant, a doping amount of carbon in the GaAs single crystal can be accurately controlled. In this manner, according to the present invention, a p-type GaAs single crystal having a uniform carrier concentration can be manufactured.
According to the present invention, when an n-type GaAs single crystal is manufactured, silicon is used as an n-type impurity, and can be doped in a raw melt. In this case, since the silicon as the n-type impurity causes the following reaction with a water content in a liquid sealant, its addition efficiency is not so good:
Si+H.sub.2 O→SiO+H.sub.2 ↑
As the n-type GaAs single crystal is grown, the reaction progresses along with the time, and the water content in the liquid sealant is decreased. For this reason, in the head portion of growth, doping efficiency is poor. However, as the growth progresses, the doping efficiency becomes better. As a result, since the silicon concentration in the single crystal is changed along the longitudinal direction of the single crystal, the carrier concentration becomes nonuniform in the longitudinal direction of the single crystal.
In this case, if a high hydrogen concentration is set in the atmosphere in the head portion of growth of the single crystal, the above reaction can be suppressed. Therefore, based on this finding, the hydrogen concentration in the atmosphere is detected and controlled, so that the doping efficiency of silicon can be controlled along with growth. As a result, a single crystal having a uniform silicon concentration in the longitudinal direction thereof can be obtained.
The O 2 and CO (or CO 2 ) concentrations in the atmosphere are detected and controlled as well as detection and control of the hydrogen concentration in the atmosphere, so that the concentrations of oxygen and carbon defining an acceptor level in the single crystal can be uniformed in the longitudinal direction of a single crystal ingot.
The present invention will now be described in detail with reference to the illustrated embodiments.
FIG. 1 is a schematic diagram showing a GaAs single crystal manufacturing apparatus according to an embodiment of the present invention. This apparatus embodies the LEC method.
In FIG. 1, reference numeral 10 denotes a high-pressure chamber, in which crucible 11 (raw material container) 11 and heater 12 are disposed. Crucible 11 contains raw melt 13 and liquid sealant 14 of, e.g., B 2 O 3 . Note that raw melt 13 and sealant 14 are separated in a two-layered state such that after the raw material of GaAs crystal and boric oxide are charged in crucible 11, they are heated and melted. Crucible 11 is attached to rotating shaft 15 to be rotated and vertically moved. Heater 12 is formed of graphite, and is arranged concentrically with crucible 11 to surround it.
Upon manufacture of a crystal, seed crystal 17 attached to the lower end of pull shaft 16 is brought into contact with GaAs melt 13 through liquid sealant 14, so that the seed crystal is wetted with melt 13. Thereafter, pull shaft 16 is gradually moved upward, so that GaAs single crystal 18 is pulled and manufactured.
The above-mentioned arrangement is the same as a conventional apparatus. The apparatus of the present invention is different from the conventional apparatus in the following points. That is, gas inlet ports 20a and 20b are formed in chamber 10, and are connected to gas cylinders 31 and 32 through electromagnetic valves 21 and 22. First gas cylinder 31 contains an inert gas, e.g., argon gas, and second gas cylinder 32 contains an inert gas, e.g., argon gas containing CO or CO 2 as a carbon supply source. Gas exhaust port 30 is also formed in chamber 10, and is connected to a vacuum pump (not shown) through electromagnetic valve 25.
Chamber 10 is connected to pressure sensor 41 for detecting a gas pressure in chamber 10, and gas analyzer 42 for analyzing the type and the content of gas. Output signals from pressure sensor 41 and gas analyzer 42 are supplied to CPU 40. CPU 40 obtains a carbon concentration based on the input data signals, i.e., the gas pressure signal and gas type signal, and controls the degrees of opening of electromagnetic valves 21, 22, and 25 based on the measured carbon concentration and a preset carbon concentration. Thus, the carbon concentration in chamber 10 can be maintained constant.
A method of manufacturing a p-type GaAs single crystal using the above-mentioned apparatus will now be described. In this embodiment, 1 kg of GaAs prepared by direct synthesis of gallium and arsenic were charged in pyrolytic boron nitride (PBN) crucible 11 as a raw melt, and 150 g of B 2 O 3 with low water content were used as a sealant. The prepared GaAs crystal had a diameter of 50 mm and a length of 100 mm. An inert gas used in the manufacture of the crystal was high-purity argon gas, and a carbon supply source was high-purity argon containing 10% of CO. A gas mass analyzer was used for analyzing gases in chamber 10. The CO concentration was detected based on the relationship between the analysis result and the gas pressure, thus estimating the CO concentration in chamber 10.
First, a correspondence between the CO concentration in high-pressure chamber 10 and a carrier concentration of the GaAs single crystal was examined. FIG. 2 shows the relationship between the CO concentration in an atmospheric gas and the carrier concentration of the GaAs crystal. From this result, in this embodiment, an attempt was made to produce a crystal having a carrier concentration of 1×10 16 cm -3 . As can be seen from FIG. 2, in order to obtain the above crystal, the CO concentration in the atmospheric gas must be 100 ppm. The CO concentration of the atmospheric gas was controlled to 100 ppm using the apparatus shown in FIG. 1 to perform crystal growth.
FIGS. 3 and 4 show a carrier concentration distribution of the produced crystal. FIG. 3 shows a carrier concentration distribution in the wafer surface in a direction of arrow in FIG. 5, i.e., a distribution in a direction of the diameter of the wafer which is cut from the crystal in a direction perpendicular to the pull shaft. FIG. 4 shows a carrier concentration distribution in a crystal pull direction, as shown in FIG. 6. In FIG. 4, mark "•" indicates a carrier concentration at the center, and mark "o" indicates a carrier concentration at a position deviated from the center by 12 mm. In the carrier concentration distribution in the direction of the diameter of the wafer which was cut from the crystal in a direction perpendicular to the pull shaft, the carrier concentration was (1±0.1)×10 16 cm -3 over the entire region, and a variation in carrier concentration was within 10%, as shown in FIG. 3. In the carrier concentration distribution in the direction of the crystal pull shaft, the carrier concentration was 1×10 16 cm -3 over the entire region, as shown in FIG. 4, and its variation was within 10%.
In this embodiment, as described above, since CO gas is used as a p-type impurity, and the CO concentration in chamber 10 is controlled to be constant, carbon can be supplied at a constant rate to a GaAs single crystal which is pulled and manufactured. As a result, a p-type GaAs single crystal can be easily manufactured. In this case, unlike zinc, carbon can be supplied in a gas state, and is stable in GaAs. Therefore, the carrier concentration can be accurately controlled. Therefore, the single crystal of this embodiment can be satisfactorily used in a field effect transistor which requires strict control of a carrier concentration of a substrate material, and is very useful.
A product yield of a GaAs crystal substrate obtained from a single crystal ingot can be greatly improved, and a variation among produced crystals is small. Therefore, p-type GaAs crystal substrates having a uniform carrier concentration can be supplied with low cost. Furthermore, when a supply amount of CO gas is varied to change a gas concentration, a carrier concentration can be easily changed.
FIG. 7 is a schematic diagram showing a GaAs single crystal manufacturing apparatus according to another embodiment of the present invention. Note that the same reference numerals in FIG. 7 denote the same parts as in FIG. 1, and a detailed description thereof will be omitted.
Crucible 11 is placed in chamber 10, and heater 12 and heat shielding member 19 are concentrically arranged around crucible 11. Pipe 51 for sampling a gas in chamber 10, gas chromatograph device 53 for quantitatively analyzing the sampled gas, and flow rate adjuster 52 for supplying the sampled gas to gas chromatograph device 53 are attached to chamber 10. Chamber 10 is connected to argon cylinder 31 containing argon gas as a major component of an atmospheric gas, carbon monoxide cylinder 32, oxygen cylinder 33, and hydrogen cylinder 34. By opening valves (electromagnetic valves) 21, 22, 23, and 24, corresponding gases are supplied into chamber 10.
With this apparatus, a GaAs single crystal having uniform carbon and oxygen concentrations in the pull shaft direction can be obtained as in the previous embodiment. A method of manufacturing a semi-insulating GaAs single crystal using the apparatus shown in FIG. 7 will be described below.
First, a total of 4 kg of gallium and arsenic as GaAs raw materials were charged in crucible 11 to obtain an atomic ratio of Ga/As=0.95, and 700 g of B 2 O 3 were then charged therein. After the interior of chamber 10 was evacuated to a vacuum of about 5×10 -2 Torr, valve 21 of argon gas cylinder 31 was opened to compress the interior of chamber 10 to about 40 atm. Thereafter, heater 12 was energized to start heating and to cause gallium to react with arsenic. The heating was continued to completely melt the raw materials to prepare raw melt 13, so that the surface of raw melt 13 was covered with B 2 O 3 liquid sealant 14.
Then, the pressure in chamber 10 was reduced to 20 atm, and raw melt 13 was adjusted to a seeding condition tenperature. In this state, a gas near crucible 11 in chamber 10 was taken in gas chromatograph device 53 through pipe 51 and flow rate adjuster 52 arranged near the opening portion of crucible 11, so that a carbon monoxide concentration was measured by a hydrogen flame ionization detector (not shown) in device 53, and the hydrogen and oxygen concentrations were measured by a thermal conduction type detector (not shown) in device 53. Thereafter, valves 21 to 24 were adjusted so that the carbon monoxide, hydrogen, and oxygen concentrations in the argon gas coincided with preset concentrations. More specifically, if the measured concentrations were higher than the predetermined concentrations, the degree of opening of valve 21 of argon gas cylinder 31 was increased to supply argon gas into chamber 10, thereby diluting the atmosphere. However, if the measured concentrations were lower than the predetermined concentrations, the degrees of opening of valves 22, 23, and 24 were increased to supply carbon monoxide, hydrogen, and oxygen gases to chamber 10.
Crystal pull shaft 16 was then moved downward by a lift mechanism (not shown) and seed crystal 17 was brought into contact with raw melt 13 through liquid sealant 14. After seed crystal 17 was sufficiently wetted with raw melt 13, a pull operation was started by the lift mechanism. While a single crystal was pulled, carbon monoxide, hydrogen, and oxygen concentrations were measured at 10-minute intervals, and valves 21 to 24 were adjusted so that the carbon monoxide, hydrogen, and oxygen concentrations always coincided with the preset concentrations (normally, constant concentrations) in accordance with a pull weight at respective times.
Wafers were cut from a GaAs single crystal prepared in this manner and having a diameter of 85 mm and a weight of 3.5 kg, and their carbon concentrations were measured by an FTIR method and their oxygen concentrations were measured by a charge particle activation analysis method. As a result, in any of head, intermediate, and tail portions of the crystal, the carbon concentration fell within the range of 2 to 3 ×10 15 cm -3 , and the oxygenconcentraiton fell within the range of 4 to 5× 10 15 cm -3 .
As described above, the components and concentrations of a gas atmosphere in chamber 10 were detected, and were controlled to be constant, and a single crystal having uniform carbon and oxygen concentrations in a pull shaft direction could be obtained. A similar single crystal pull operation was continuously repeated ten times. As a result, in a wafer which was cut from any portion of a single crystal, the carbon concentration fell within the range of 2 to 3×10 15 cm -3 , and the oxygen concentration fell within the range of 4 to 5×10 15 cm -3 . In addition, high reproducibility was demonstrated.
A method of manufacturing an n-type GaAs single crystal using the apparatus shown in FIG. 7 will now be described.
The n-type GaAs single crystal is manufactured following basically the same procedures as that of the semi-insulating GaAs described above, except that GaAs raw materials and silicon as an n-type impurity are charged in crucible 11. More specifically, n-type GaAs raw melt 13 doped with silicon as a dopant is formed in crucible 11, and its surface is covered with B 2 O 3 liquid sealant 14. In this state, a GaAs single crystal is pulled and manufactured following the same procedures as described above.
Wafers were cut from an n-type GaAs single crystal having a diameter of about 55 mm and a weight of 1 kg, and their carrier concentrations were determined by Hall measurement. As a result, the carrier concentration fell within the range of 7 to 9×10 17 cm. In any of head, intermediate, and tail portions of the single crystal. More specifically, the concentrations of gas components in chamber 10 were detected and controlled, so that a single crystal having a uniform carrier concentration in the longitudinal direction of the crystal could be obtained.
Note that the present invention is not limited to the above embodiments. For example, a means for detecting a gas concentration is not limited to a gas chromatograph device, but may be any means which can easily detect a gas concentration. In the above embodiment, a crystal growth apparatus based on the LEC method has been exemplified. However, the present invention can be applied to any other apparatuses which can grow a single crystal from a raw melt by a method other than pulling. A crystal to be grown is not limited to GaAs, but may be any other compound semiconductors, e.g., GaP, InP, and the like.
CO 2 can be used as a supply source of carbon as a p-type impurity in place of CO. Furthermore, a gas material containing carbon as a major component can be used. The present invention is not limited to a crystal pull apparatus utilizing the LEC method but may be one which can dope carbon gas in a raw melt upon crystal growth. More specifically, the present invention can be applied to various other manufacturing apparatuses which do not have a closed tube type raw material container. Various other changes and modifications may be made within the spirit and scope of the invention.
As described above, according to the present invention, a raw material container containing a raw melt is placed in a predetermined gas atmosphere, and the concentrations of atmospheric gas components are controlled to be constant, so that a carrier concentration of the resultant crystal can be uniformed. Therefore, a compound semiconductor single crystal can be easily manufactured from a raw melt, and its carrier concentration can be uniformly controlled, thus allowing a wide application range.
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Disclosed is a method of manufacturing a compound semiconductor single crystal, wherein a container containing a raw melt is placed in an atmosphere containing at least one monitor gas selected from the group consisting of hydrogen, oxygen, carbon monoxide, and carbon dioxide, a concentration of the monitor gas in the atmosphere is detected, and the detected concentration of the monitor gas is controlled to be a preset value. A compound semiconductor single crystal having a uniform carrier concentration can be obtained by controlling the concentration of the monitor gas.
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REFERENCES CITED
German Patent DE 3641 365 (1988) Klose; G.
European Patent EP 6682 44 (1994) Batt; S.
PCT/WO. 95/15295 (1995) Beaujean; H.
U.S. Pat. No. 6,179,991 (2001) Norris; B.
U.S. Pat. No. 6,663,766 (2003) Adin; A.
OTHER REFERENCES
Matteson, Michael J., Dobson, Regina L. et al., Electrocoagulation and separation of aqueous suspensions of ultrafine particles, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 104; 1 (November): 101-109 (1995).
Vik, E A, Carlson, D A, Eikun, A S and Gjessing, E T, Electrocoagulation of potable water, Water Research, 18; 11: 1355-1360 (1984).
FIELD OF THE INVENTION
This invention relates to water treatment and relates particularly, though not exclusively, to treating polluted water using electroflocculation and/or electrocoagulation reactions.
BACKGROUND OF THE INVENTION
Electroflocculation cells have been described in the prior art (see for example German Patent DE 3,641,365 to Klose, U.S. Pat. No. 6,179,991 to Norris, U.S. Pat. No. 6,663,766 to Adin, European Patent EP 6682 44 to Batt; and PCT International Application PCT/WO. 95/15295 to Beaujean).
The publication by Matteson, Michael J., Dobson, Regina L. et al “Electrocoagulation and separation of aqueous suspensions of ultrafine particles”, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 104; 1 (November): 101-109 (1995), and the publication by Vik, E A, Carlson, D A, Eikun, A S and Gjessing, E T, “Electrocoagulation of potable water”, Water Research, 18; 11: 1355-1360 (1984) describe electroflocculation cells or electroflocculation systems.
A disadvantage of the prior art electroflocculation cells is tendency to foul. Solutes present in many ambient waters, such as Calcium Sulfate or Calcium Carbonate or other solutes, are present at or near saturation. Such solutes have a tendency to form scales and foul the equipment. Commonly present suspended hydrocarbons, turbidity, colloids, and particles may also form strongly adherend deposits and oil films on the cell electrodes, thereby causing local pitting resulting in low current efficiency.
Klose, German Patent DE 3641 365 describes an apparatus in which electroflocculation takes place by serpention flow of contaminated water through a bed of vertical positioned electrodes of alternating iron and aluminium sheet metal. Practical examination shows that this configuration has a low volume capacitiy and shows a strong tendency to form nonconducting deposits on the electrodes resulting in low current efficiency.
A similar apparatus in form of a stack of horizontal electrodes made of perforated iron and aluminium metal sheet has been submitted by Adin, U.S. Pat. No. 6,663,766. This electroflocculation cell has local stagnant areas prone to fouling and requires costly machining of the electrode stack.
A vertical and parallel array of aluminium and/or iron electrodes plus a stream of compressed air alongside these electrodes has been proposed by Beaujean PCT/WO. 95/15295. This stream of compressed diminishes fouling of the apparatus, however examination in practice reveals that the current efficiency of this design is poor.
A high volume column type electroflocculation cell has been disclosed by Batt European Patent EP 6682 44. This design however requires one of the electrodes to be of the composite type, something that turns out to be more costly than the use simple electrodes. Moreover, composite electrodes tend to be unstable due to the different dissolution rates of aluminium and iron.
Norris, U.S. Pat. No. 6,179,991 proposes a machine for treating contaminated water comprising a chamber with at least two electrodes having voltages of different polarities and made of multivalent metals and one or more scraper blades in substantial contact with said electrodes wherein said blades are capable of movement along the length of said electrodes to remove accumulated debris. Despite that the problem has been correctly recognized no practical realization is possible because the electrodes thin out. Since an additional cleaning mechanism is necessary this proposal becomes very costly.
There is therefore a significant and unfulfilled need for a new and improved flow-through electroflocculation apparatus, method and system. Such an electroflocculation cell would be resistant to fouling and have high current efficiency. It would furthermore be desirable for such an electroflocculation cell to be easy to manufacture, and not require any unnecessary parts that increase cost, or limit the usefulness of the electroflocculation cell.
SUMMARY OF THE INVENTION
This invention is directed to an electroflocculation cell that meet this need. The cell comprises two electrodes, a “top” and a “bottom” electrode having voltages of different polarities and made of iron and/or aluminium which form multivalent salts. Said electrodes are in constant or periodic movement thereby minimizing the build-up of organic or inorganic deposits.
The lower (or “bottom”) electrode consists of a non-fluidized porous bed of loose iron and/or aluminium granules, kept in periodic motion by pulsed gas injections. This porous bed electrode rests on a tilted conductive support said conductive support being connected to a electric current source.
The upper (or “top”) vibrating electrode is made of an iron/and or aluminium grid mesh or ribmesh. Said top electrode is connected to a electric current source of opposite polarity with regard to the bottom electrode and said top electrode is held in constant motion by means of a mechanical vibrator.
a) Water containing contaminants susceptible to flocculation and precipitation upon electrolysis of the water is pumped upwards first through the porous bottom electrode and thereafter the water contacts the top electrode. (b) by energizing the top and bottom electrodes with direct current, the electrolyzed water forms a sedimentable flocculate therein. Suspended solids able to flocculate in this cell include bacteria, parasites, algae, paint and other pigments, carbon black, asbestos fibres, industrial grit, clay and similar.
The insoluble contaminants are separated from the substantially cleansed water by known methods such as mechanical filtering or by centrifuging.
Another object of the invention is the system and process to treat waste streams that are both complex and with variable contaminate compositions.
This new, state-of-the-art, technique is simple. It does not require expensive electrodes, nor does it use sophisticated equipment. Energy requirement is also minimal for there is a higher current efficiency. Another object of the present invention is to provide a high volume, foul-resistant electroflocculation process which uses much less costly equipment. All the problems that are circumvented by this new method are clearly present in all prior disclosed methods of electroflocculation.
Further objects and advantages will become obvious by comparison of this simple, economical method described herein and conventional uneconomical methods.
These and other objects of the present invention will become apparent to those familiar with various types of processes and systems for electrolytic, electroflocculation or electrocoagulation treatment of high volumes of contaminated water when reviewing the following detailed description, showing novel construction, combination, and elements as herein described, and more particularly defined by the claims, it being understood that changes in the embodiments to the herein disclosed invention are meant to be included as coming within the scope of the claims, except insofar as they may be precluded by the prior art.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a flow diagram and the individual components making up the subject high volume electroflocculation cell for treating and cleaning contaminated water streams.
DETAILED DESCRIPTION OF THE INVENTION
It is to be understood, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.
Turning now to FIG. 1 , an electroflocculation cell according to my invention is schematically illustrated.
The electroflocculation cell comprises a generally rectangular casing ( 1 ) composed preferably of a suitable non-conductive material. The cell casing ( 1 ) can however be of any material or design that will contain aqueous solutions and of any geometric shape that will allow contaminated water upflow between charged electrodes, as discussed hereinafter. The material should be chemically inert or corrosion-resistant, preferably non-conductive, although the casing may be composed of metal if proper insulation is applied. The casing ( 1 ) has an inlet supply pipe ( 1 a ) at its bottom and a treated water outlet ( 1 b ) at its top in order to discharge the treated medium. The aqueous medium is flowed through the casing as illustrated at FIG. 1 , by means of a suitable pump ( 7 ) for treatment, as described hereinafter, and discharged to a suitabe vessel, tank or other electroflocculation cell of the same type. The pump ( 7 ) may be operable at either a fixed rate or selectable variable rate. Suction line ( 7 a ) may be connected either to a water reservoir to be treated or to another electroflocculation cell.
It should be understood that more than on cell may be connected in parallel or series.
With reference to FIG. 1 , the electroflocculation cell comprises a pair of electrodes ( 3 ) and ( 4 ). Each electrode is separately connected to a source of electric current ( 5 ) by means of electrical feeder cables ( 5 a ) and ( 5 b ). At least one of the electrodes is isolated within the casing ( 1 ).
The electrode ( 3 ) consists of a porous, non-fluidized bed of loose iron and/or aluminium granules kept in periodic motion by pulsed gas injections.
The electrode ( 3 ) is supported by a conducting, tilted support plate ( 2 ) which has a suitable number of nozzle inlets ( 2 a ), for flowing aqueous medium through the cell. Preferably the support plate ( 2 ) has a tilting angle of more than about 5 degrees and less than about 65 degrees. The nozzle inlets ( 2 a ) preverably have an inner diameter smaller than that of the average diameter of the metal granules of bed electrode ( 3 ). The tilted support plate is preverably made from iron or aluminium and is connected to the electrical torrent source via feeder cable ( 5 b ).
As water is pumped upward from inlet pipe ( 1 a ) into the bottom part of the casing ( 1 ) and through nozzle inlets ( 2 a ), the water enters the porous bed of metal granules ( 3 ). The metal is preferably aluminium or iron. It is preferred that the average particle size of the metal granules be at least about 1 mm in size and range up to about 6 mm. The volume of the electrode bed ( 3 ) should be that volume which will assure electro-chemical activity of the bed to pass current. The flow capacity of the feed pump ( 7 ) must be regulated so that the electrode bed ( 3 ) does not expand or gets fluidized under the action of the water flow for this would dramatically lower the current efficiency of the cell.
With reference to FIG. 1 , a few centimeters situated parallel and above the bottom electrode ( 3 ), the second and top electrode ( 4 ) is situated. Electrode ( 4 ) is made of commercial iron or aluminium grid mesh or ribmesh and is held in position by metal rod ( 4 a ) (only one shown).
Metal rods ( 4 a ) are connected to mechanical vibrators (not shown in the drawing), which causes the vibration ( 4 b ) of electrode ( 4 ). The amplitude of these vibrations ( 4 b ) of the electrode ( ) 4 is about 0.1 mm to about 1 o mm and the frequency of this vibration is preferably between about 0.1 to 100 per second.
Near the bottom of the casing ( 1 ) and embedded in granule bed ( 3 ) is positioned gas injection tube ( 6 ), which features a number of small holes (not shown) so that gas-pulses can be injected into the lower part of electrode bed ( 3 ). These gas pulses have a pulse-duration of between about 0.2 to about 2 seconds and cause a mixing action in the whole electrode bed ( 3 ). This mixing action is very slow and enhanced by the tilt of the support plate ( 2 ). The completion of one total mixing takes two to three days. According to my experiments the gas injections cause the electrode bed ( 3 ) to be in slow motion. By this slow mixing movement, fresh granules are constantly supplied to the water boundary facing the electrode ( 4 ), resulting in an outstanding current efficiency of my electroflocculation cell design.
With reference again to FIG. 1 , the aforesaid gas injection tube ( 6 ) is connected via pipe ( 6 a ) to magnet-operated valve ( 6 b ) and to pressure gas pipe ( 6 c ). Air or Nitrogen are the preferred gases to be injected into electrode bed ( 3 ), the preferred gas pressure being between about 4 to 40 bars. Electronic controller ( 6 d ) sends pulses of about 0.2 to about 2 seconds duration to magnet-operated valve ( 6 b ). In order to achieve the slow movement of the electrode bed 3 about 5 to 50 gas injections have to be performed per each operating hour of the electroflocculation cell.
In use, water containing contaminants such as bacteria, heavy metals, oils, grease, hydrocarbons, volatile organic compounds, metals and cyanide complexes enters into the inlet ( 7 a ) of the pump ( 7 ) and flows into casing ( 1 ) via inlet ( 1 a ) and exits via the outlet ( 1 b ). The influent water source may be a holding tank, sump, pit, pond, lagoon and the like. At the same time, a voltage is applied between the electrodes ( 3 ) and ( 4 ). While a wide range of voltages may be used, a voltage in the range of from about 10 volts to about 30 volts has been found to be necessary to effect the flocculation of all wastewater contaminants. Operating the voltage in this range produces mean electrode current densities of from 2-9 milliampere/sq. cm and localized, point current densities as high as from 8-80 milliampere/sq. cm, sufficient to partially oxidize the oils, greases, hydrocarbons, volatile organic compounds and other organics in the wastewater by opening double bonds and thereby changing the polarity of the contaminants making them more compatible with the polar chemical flocculating agents. The electrical operating conditions at the electrodes ( 3 ) and ( 4 ) effect the oxidation of volatile organic compounds quantitatively as well as other organics to a significant degree.
Operating the voltage at a range from 15 to 20 volts also promotes the oxidation of the electrodes to form metal-hydroxides. The enhancement of aluminium and/or iron hydroxide formation is a result of the effect of the high voltage operation on the surface of the electrodes.
Gas bubbles created by the electrolytic action lift the greater parts of the coagulated solids to the air-water interface of the electroflocculation cell, creating floating sludge ( 8 ) which can be easily collected by mechanical means. Both electrodes slowly sacrifice themselves but, due to their easy and low cost availability and the absence of any dismantling process, with this electroflocculation design the present invention will operate hundred of hours before any maintenance is required.
EXAMPLE I
An electroflocculation cell according FIG. 1 contained as electrode ( 3 ) aluminium granules (pellets) of 2-3 mm diameter. This bed of aluminium granules rested on a 5 mm aluminium metal plate as the support ( 2 ). The metal plate ( 2 ) had various 1 mm diameter openings ( 2 a ). The tilting angle of the support ( 2 ) was 20 degrees. At the thickest part of the granule bed ( 3 ) and attached to the support plate ( 2 ) a gas injection tube ( 6 ) of 25 mm outer diameter was positioned. This gas injection tube was equipped with a number of tiny openings to permit passage of the gas directed into the granule bed ( 3 ). The medium depth of the granule bed was 40 cm.
Directly above the granule bed electrode ( 3 ) an aluminium gridmesh electrode ( 4 ) as a 4 mm strong perforated metal plate had been attached via metal rods ( 4 a ) to a mechanical vibrator.
The perforations represented 45% of the metal plate ( 4 ).
Measured submerged, the average vibration amplitude of the gridmesh electrode ( 4 ) was 1 mm. Vibration frequency was 50 Hz.
The distance between electrode ( 3 ) and ( 4 ) was 3 centimeters.
Turbid water from a pond which, after test-filtration across a coarse sand filter still containing nonfilterable remnants of suspended clay solids (TSS) of 800-1000 milligrams/liter, was directed into the electroflocculation cell.
The capacity of pump ( 7 ) was maintained at 30% of a flow rate which would have caused the granule bed ( 3 ) to fluidize.
The electrodes ( 3 ) and ( 4 ) received a constant supply of 250 amperes/m3-flow/hour.
Every 2 minutes the magnet-valve ( 6 b ) attached to the 16 bar air pressure line ( 6 c ) openend for one second, and with help of the pressure gas pulse slowly mixed the aluminum granules of electrode ( 3 ).
After 30 hours of use constant operating conditions were achieved. And now the flocculated effluent from the cell after filtration over a coarse sand filter showed a TSS of only 2 bis 6 milligrams/Liter.
EXAMPLE II
An electroflocculation cell according FIG. 1 contained as electrode ( 3 ) iron granules of 1-3 mm diameter. This bed of granules rested on a 6 mm steel plate as the support ( 2 ). The steel plate ( 2 ) had various plastic nozzles with 0.7 mm openings ( 2 a ). The tilting angle of the support ( 2 ) was 28 degrees. At the thickest part of the granule bed and attached to the support plate ( 2 ) a gas injection tube ( 6 ) of 20 mm outer diameter was positioned. This gas injection tube was equipped with a number of tiny openings to permit passage of the gas directed into the granule bed ( 3 ). The medium depth of the granule bed was 60 centimeters.
Directly above the granule bed electrode ( 3 ) an rib mesh electrode ( 4 ) made from 8 mm diameter steel wire had been attached via metal rods ( 4 a ) to a mechanical vibrator.
The perforations represented 85% of the electrode area ( 4 ).
Measured submerged, the average vibration amplitude of the rib mesh electrode ( 4 ) was 2 mm. Vibration frequency was 50 Hz.
The distance between electrode ( 3 ) and ( 4 ) was 4 centimeters.
Turbid water from a pond which, after test-filtration across a coarse sand filter still containing nonfilterable remnants of suspended clay solids (TSS) of 800-1000 milligrams/liter, was directed into the electroflocculation cell.
The capacity of pump ( 7 ) was maintained at 20% of a flow rate which would have caused the granule bed ( 3 ) to fluidize.
The electrodes ( 3 ) and ( 4 ) received a constant supply of 200 amperes/m3-flow/hour.
Every 3 minutes the magnet-valve ( 6 b ) attached to the 25 bar nitrogen pressure line ( 6 c ) openend for one second, and with help of the pressure gas pulse slowly mixed the iron granules of electrode ( 3 ).
After 38 hours of use constant operating conditions were achieved. And now the flocculated effluent from the cell after filtration over a coarse sand filter showed a TSS of only 0.5 to 1 milligrams/Liter.
While the invention has been described above with references to specific embodiments thereof, it is apparent that many changes, modifications and variations in the material, arrangements of parts and steps can be made without departing from the inventive concept disclosed herein. Accordingly, the spirit and broad scope of the appended claims is intended to embrace all such changes, modifications and variations that may occur to one of skill in the art upon a reading of the disclosure. All patent applications, patents and other publications cited herein are incorporated by reference in their entirety.
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The present invention provides a high volume, foul-resistant electrolytic process for treating contaminated water comprising at least one upflow electroflocculation cell consisting of (i) a lower (or “bottom”) electrode ( 3 ) in form of a porous, non-fluidized bed of loose iron or aluminium granules kept in periodic motion by pulsed gas injections and (ii) an upper (or “top”) vibrating electrode ( 4 ) made of an iron or aluminium grid mesh or ribmesh. A voltage potential between the upper ( 4 ) and lower ( 3 ) electrode causes ions to be released from the moving electrodes. These ions oxydise and/or render insoluble contaminants in the ascending flow of wastewater and create easy filterable insoluble contaminants resulting in substantially cleansed water. Such moving electrodes electroflocculation cells are useful at municipal water works and commercial and industrial applications were large amounts of raw water have to be processed.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a process for manufacturing an electrochemical device comprising at least one component based on a ceramic or ceramic containing material, for example cermets (ceramic and metallic composites), and for preparing nanosize powders for producing said at least one component.
[0002] The active basic structure of an electrochemical device such as a solid oxide fuel cell (SOFC) or an oxygen generator consists of an electrolyte layer (electrolyte membrane) interposed between an anode and a cathode. Typically, electrolyte membrane, cathode and anode contain ceramics and/or cermets.
[0003] In the present specification and claims, ceramic and cermet materials are collectively referred to as “ceramics” or “ceramic materials”.
PRIOR ART
[0004] The effectiveness of ceramics in electrochemical devices depends upon the characteristics of the powders used as starting materials which are used to produce bulk ceramic products. In general, to achieve desirable characteristics in the finished products, a ceramic powder should consist of particles with a narrow size distribution in the submicron range. In addition, to avoid pores larger than the mean primary grain size, the particles should be finally subdivided, rather than aggregated in agglomerated clusters. Agglomerated clusters often produce low-density green ceramics and leave numerous large pores after sintering. Finally, it is important that the ceramic powder is substantially free of contaminants to insure purity of the resulting high technology ceramic. Nanosize powders are expensive and difficult to prepare in large quantities. As reported by A. Sin and P. Odier, Advanced Materials Vol. 12, No. 9 (2000) 649-652, a method commonly applied for obtaining fine powders is the so-called solid-state reaction or “ceramic way”. It involves intimate mechanical mixing of oxides, carbonates or nitrates, repeated grinding and heating cycles to achieve complete reaction between all reagents. However, besides its simplicity, this technique has clear disadvantages because it provides large grain size (1-10 μm) and requires multiple repetitions of prolonged thermal treatment and grinding. As a consequence, uncontrolled crystalline growth might occur which causes chemical and dimensional non-uniformity.
[0005] Synthesis using wet chemistry, often called “chemical route”, can overcome many of these disadvantages. The homogeneity of the product is expected to increase because mixing of the reagents occurs at a molecular level, in solution. The resulting powders have a high specific surface area and, consequently, have a high reactivity that decreases the final temperature treatment and time of synthesis. Different chemical routes exist to form fine ceramic powders such as co-precipitation, spray drying, freeze drying, sol-gel. Unfortunately these methods are time consuming if large quantity of fine powders are to be obtained. Moreover, obtaining a high homogeneity for complex compositions (involving different metal cations) might become very difficult owing to the generally different chemical behavior of each cation.
[0006] FR 2 628 664 (in the name of Rhône-Poulenc Chimie) illustrates the preparation of ultrafine and homogeneous powders of simple or mixed mineral oxide by preparing a stable cation solution (Sol), where an organic macromolecular matrix (gel) is formed. Said matrix is prepared by polymerizing and/or copolymerizing, e.g. by polycondensing one or more organic monomer previously added to said solution or sol. Acrylamide or methacrylamide are used as monomers, N,N′-methylenediacrylamide as cross-linker, in the presence of tetramethylene-ethylenediamine (TEMED) as polymerization accelerator, and ammonium persulfate as polymerization initiator. The resulting powders have an average mean primary grain size comprised between 0.1 and 0.5 μm.
[0007] A. Sin and P. Odier, supra, relate to the use of acrylamide gel for obtaining a 3D organic matrix in a cationic solution, especially for preparing oxide nanopowders. However, the presence of chemical elements such as transition elements (Cu, Ni, Mn), rare-earth elements (La, Y) and metalloid elements of the p-group (Bi) impedes the gel formation because they react with acrylamide monomers to form complexes. For this reason, formation of gels containing, e.g. copper and yttrium, is possible only when a low concentration of cations is used. In order to avoid this side-reaction, a chelating agent, e.g. EDTA, is commonly used to sequester the cation from the monomers. Nevertheless, different side-reactions may affect the formation of the chelate, depending on the nature of the cation used. In these cases, it is appropriate to chelate each cation separately, in its most stable range of pH.
[0008] The drawbacks discussed by the above document are of particular importance in manufacturing nanosize crystallite powder for electrochemical devices such as solid oxide fuel cells wherein transition elements and rare-earth elements like lanthanum and yttrium are widely used. For example, in the case of SOFC, electrolyte membrane can be yttria-doped zirconia (YSZ), La(Sr)MnO3 (LSM) can be used as cathode material, and a cermet comprising Ni can be provided as anode material (B. C. H. Steele and A. Heinzel, Nature, vol. 414, 2001, 345-352).
[0009] U.S. Pat. No. 5,698,483 (in the name of Institute of Gas Technology) relates to a process for producing nanosize powders comprising the steps of mixing an aqueous continuous phase comprising at least one metal cation salt with a hydrophilic organic polymeric disperse phase, forming a metal cation salt/ /polymer gel, and heat treating the gel at a temperature sufficient to drive off water and organics within the gel, leaving as a residue a nanometer particle-size powder. By the term “gel” it is meant a colloid in which a disperse phase is combined with a continuous phase to produce a viscous gel-like product. Among the hydrophilic organic materials, 2-hydroxyethylenemethacrylate, hydroxyalkylmethacrylate, hydroxyalkylacrylate and acrylamide are listed. Examples are provided which employ polyethyleneglycol, methylcellulose or polyurethane in solution with a metal cation at concentration lower than 0.4 mol/l in water.
SUMMARY OF THE INVENTION
[0010] The Applicant has perceived that a key-point for manufacturing electrochemical devices with reliable and efficient performance lies in providing cathode, anode and/or electrolyte membrane based on ceramics prepared from nanosize powders. A process for producing nanosize powders is desirable, which should allow large scale production of substantially pure, homogeneous powders in high yields.
[0011] The Applicant has found that by a process comprising in situ formation of a gel from a hydrosoluble ethylenically unsaturated ester monomer and a cross-linker eliminates the problem of metal cation interaction, and allows the large scale obtainment of nanosize chemically complex products in a single batch and without the necessity of employing chelating agents.
[0012] Therefore, the present invention relates to a process for manufacturing an electrochemical device including a cathode, an anode and at least one electrolyte membrane disposed between said anode and said cathode, wherein at least one of the cathode, the anode and the electrolyte membrane, each containing at least a ceramic material, is produced by performing at least the following steps of:
thermally treating an aqueous solution comprising at least one metal cation, at least one hydrosoluble ethylenically unsaturated monomer with an ester moiety, and a hydrosoluble cross-linking monomer with at least two ethylenically unsaturated ester moieties, to provide a gel and to obtain said at least one metal cation in an oxide form; calcining said gel to remove organic substances and to form a crystal phase of said at least one metal oxide in a nanosize powder form; sintering said powder to provide the ceramic material.
[0016] Examples of electrochemical devices which can be manufactured according to the process of the present invention are solid oxide fuel cells (SOFCs), molten carbonate fuel cells (MCFCs), gas separators and gas sensors.
[0017] Examples of ceramic materials useful for the anode of the electrochemical device manufactured according to the inventions are ceramic composite materials (cermet) wherein the metallic portion can be selected from copper, aluminum, gold, praseodymium, ytterbium, cerium, nickel, iron, cobalt, molybdenum, platinum, iridium, ruthenium, rhodium, silver, palladium, and the ceramic portion can be selected from yttria-stabilized zirconia (YSZ), ceria doped with gadolinia (CGO) or samaria (SDC), and La 1-x Sr x Ga 1-y Mg y O 3−δ wherein x and y range from 0 to 0.7, extremes included, and δ is from stoichiometry; or ceramics such as cerium oxide (ceria), manganese oxide, molybdenum oxide, titania, SDC, CGO, niobia-doped ceria, and perovskite-like composites such as La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3 (LSCM) and La 0.8 Sr 0.2 Fe 0.8 Co 0.2 O 3−δ (LSCFO).
[0018] Examples of ceramic materials useful for the electrolyte membrane of the electrochemical device manufactured according to the inventions are YSZ, CGO, SDC and La 1-x Sr x Ga 1-y Mg y O 3−δ wherein x and y are as above.
[0019] Examples of ceramic materials useful for the cathode of the electrochemical device manufactured according to the inventions are oxides of rare earth elements, such as praseodymium oxide, perovskites as those above, optionally in combination with a doped ceria, and mixtures thereof.
[0020] As aqueous solution is intended a solution wherein as solvent water or a mixture of water and at least one hydrosoluble solvent is used. As hydrosoluble solvent an alcohol, glycol, tetrahydrofuran, dioxane may be used.
[0021] Examples of metal cations suitable for the process of this invention comprise lanthanum, strontium, chromium, zirconium, yttrium, aluminium, lithium, antimony, boron, cadmium, cerium, cobalt, copper, dysprosium, erbium, europium, gallium, gold, hafnium, holmium, iridium, iron, lutetium, manganese, molybdenum, nickel, niobium, osmium, palladium, platinum, praseodymium, rhenium, rhodium, rubidium, ruthenium, samarium, scandium, silver, sodium, tantalum, terbium, thorium, thulium, tin, titanium, tungsten, uranium, vanadium, ytterbium.
[0022] The at least one metal cation solution can be obtained by dissolving a hydrosoluble precursor thereof. Examples of precursors are oxides, chlorides, carbonates, β-diketonates, hydroxides, nitrates, acetates, oxalates, and mixtures thereof. Additional considerations for selecting the cation precursor may include low temperature decomposition and environmentally safe composition of the cation precursors.
[0023] Advantageously, the concentration of the at least one metal cation in the aqueous solution is higher than 0.5 mol/l, preferably from 1 to 10 mol/l. It should be noted that the process of the invention allows to use such high concentration of metal cation, thus providing high yield of product.
[0024] It should be also noted, that the process of the invention allows to obtain stable metal cation solution in the substantial absence of any chelating agent.
[0025] Preferably, hydrosoluble ethylenically unsaturated monomers with an ester moiety used in the process of the present
[0000]
[0000] invention are encompassed by the general formula (I)
[0026] wherein R is hydrogen, (C 1 -C 4 )alkyl, aryl or aryl(C1-C4)alkyl; R 1 is a C 1 -C 8 hydrocarbon group containing at least one polar group selected from —COOH, —NH 2 , —NHR′, —N(R′) 2 , —OH, —OR′—SO 3 H, —SH, wherein R′ is a (C 1 -C 6 )alkyl group; and R 2 is hydrogen, methyl, ethyl, propyl or phenyl.
[0027] Preferably R′ is a (C 1 -C 4 )alkyl group.
[0028] Examples of monomers of formula (I) are (meth)acrylate monomers such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl phenacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, butandiol monoacrylate, 2-(2-ethoxyethoxy)ethyl acrylate, dimethylamino ethyl acrylate, and dimethylamino ethyl methacrylate.
[0029] Cross-linking monomers useful in the present process are preferably selected from diacrylates and triacrylates wherein the acrylates groups are linked to alkoxylated moieties or polyoxyalkylene linear units. Examples are polyethyleneglycol diacrylate, ethoxylated trimethylolpropanetriacrylate.
[0030] Advantageously, said aqueous solution comprises a hydrosoluble polymerization initiator, such as α,α′-azaisobutyronitrile (AIBN), tetramethylene-ethylenediamine, peroxides, e.g. hydrogen peroxide, benzoyl peroxide or dicumyl peroxide, persalts, e.g. ammonium, sodium or potassium persulfate.
[0031] Preferably, the aqueous solution is thermally treated at a temperature ranging between about 50° C. and about 150° C.
[0032] By the term “gel” as used throughout the specification and claims, it is intended a jellylike, non-flowable structure based on a polymeric network entrapping a liquid phase comprising solvent, reactants and not cross-linked polymer chains. Before proceeding to the calcining step, the gel obtained by the process of the invention is optionally dried to obtain a xerogel.
[0033] Said xerogel is a substantially dry, hard gel resulting from the removal of the aqueous phase from the gel, which usually causes a shrinkage of the gel network.
[0034] This optional drying step is preferably carried out by heating at a temperature ranging between about 80° C. and about 300° C.
[0035] Advantageously, the xerogel is disaggregated by known techniques, e.g. grinding or ball-milling, and subjected to the calcining step.
[0036] The calcining step is preferably carried out at a temperature ranging between about 300° C. and about 1500° C. This treatment results in the removal of residual impurities such as solvent and organic substances, and the crystallization of the oxide or mixed oxide phase in form of a nanosize powder.
[0037] In an embodiment of the invention, the calcining step is carried out by progressively increasing temperature. This is preferable when the temperature for eliminating the impurities is different, and it is typically lower, than the crystallization temperature. Advantageously, at least one grinding step of the powder is carried out at an intermediate stage of the calcining step.
[0038] As “nanosize powder” it is intended a powder having a mean primary grain size lower than 1,000 nm, preferably lower than 100 nm. Advantageously, the nanosize powders obtained by the process of the present invention show a mean primary grain size lower than 20 nm, for example comprised between about 3 nm and 15 nm.
[0039] By the term “primary grain size” as used throughout the specification and claims, it is intended the size of the primary particles which are distinguishable units in a transmission electron micrograph (TEM).
[0040] Advantageously, before the sintering step the nanosize powder is compacted in pellets or shaped in form of anode, cathode or electrolyte membrane for electrochemical devices.
[0041] The sintering step is carried out at temperatures depending on the nature of the components of the desired ceramic.
[0042] When a cermet is desired, a nanosize powder comprising all of the constituents of the final product is advantageously prepared. Alternatively, a nanosize powder of oxide precursor/s of the metallic portion is prepared separately from the nanosize powder of oxide/s of the ceramic portion. In both of the cases, a reduction step is effected, advantageously together with the sintering step in the latter case, for example under hydrogen atmosphere.
[0043] Advantageously the sintering temperatures are lower than those for powders prepared in accordance with the teachings of the prior art. For example, La 0.60 Sr 0.40 Fe 0.80 Co 0.20 O 3−δ , was obtained by sintering at 700° C., 500 lower than the sintering temperature reported by the prior art (S. Wang, T. Kato, S. Nagata, T. Honda, T. Kaneko, N. Iwashita, M. Dokiya, Solid State Ionics, 146 (2002), 203-210).
[0044] Advantageously, the ceramic or cermets material are obtained by the process of the present invention already in the shape suitable for an anode, a cathode or an electrolyte membrane of an electrochemical device.
[0045] Another object of the present invention relates to a process for manufacturing a nanosize oxide powder, the process comprising the steps of:
thermally treating an aqueous solution comprising at least one metal cation, at least one hydrosoluble ethylenically unsaturated monomer with an ester moiety, and a hydrosoluble cross-linking monomer with at least two ethylenically unsaturated ester moieties, to provide a gel and to obtain said at least one metal cation in an oxide form; calcining said gel to remove organic substances and to form to form a crystal phase of said at least one metal oxide in nanosize powder form.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0048] The invention will be further illustrated hereinafter with reference to the following examples and figures, wherein:
[0049] FIG. 1 schematically represents an example of electrochemical device;
[0050] FIGS. 2-6 show X-ray diffraction (XRD) patterns of powders obtained with the process of the invention.
[0051] FIG. 1 schematically illustrates a fuel cell comprising anode ( 1 ), cathode ( 2 ) and electrolyte membrane ( 3 ) with the reactant/product gases and the ion conduction flow directions through the cell. Gaseous fuels ( 4 ), e.g. hydrogen, hydrocarbons, alkali carbonates are fed to the anode ( 1 ) (negative electrode) and an oxidant ( 5 ) (i.e., oxygen from air) is fed to the cathode ( 2 ) (positive electrode); the electrochemical reactions take place at the electrodes to produce an electric current. Depleted fuel ( 4 a ) and depleted oxidant ( 5 a ) are eliminated optionally with by-products of their reactions.
[0052] The architecture of an oxygen separator is substantially analogous (anode, cathode and electrolyte membrane). Similarly to a fuel cell, air or an oxygen containing gas ( 5 ) is provided to the cathode ( 2 ). By an electrical potential applied across an oxygen ion conductive electrolyte membrane ( 3 ) via electrodes, oxygen is dissociated and reduced at the cathode ( 2 ). Oxygen ions travel through the electrolyte membrane ( 3 ), and are oxidized and recombined at the anode ( 1 ) to produce oxygen.
EXAMPLE 1
Cerium/Gadolinium Oxides Nanopowder and Ce 0.8 Gd 0.2 O 1.9
[0053] 1.8716 g of Ce(NO 3 ) 3 .6H 2 O and 0.4279 g of Gd(NO 3 ) 3 .6H 2 O were added to 10 ml H 2 O while stirring and heating up to 50° C. to provide a solution with a metal cation concentration of 0.538 mol/l. 10 ml of 2-hydroxyethylmethacrylate and 5 ml polyethyleneglicoldiacrylate were added. The solution was heated up to 100° C. 20 drops of 35 vol % H 2 O 2 were added to initiate the gel formation.
[0054] The resulting gel was decomposed at 500° C. for 5 h. 1 g of the title compound was obtained and characterized as follows.
[0055] The XRD pattern of FIG. 2 shows that the sample is monophasic and Ce 0.8 Gd 0.2 O 1.9 powder has a mean primary grain size of 10 nm calculated using the Debye-Scherrer formula (A. R. West, “Solid State Chemistry and its application” Ed. John Wiley & Sons, 1996, page 174).
[0056] The nanopowder was compacted in pellet under an uniaxial pressure of 200 MPa and sintered at a temperature of 800° C. for 5 hours, then at 1450° C. for 3 hours.
[0057] Density measurement using the method of Archimede (PSS model, Gibertini, Italy) showed a relative density >95% of the crystallographic one.
EXAMPLE 2
Copper/Nickel Oxides Nanopowder and Cu 0.47 Ni 0.53 Alloy (1:1 by Weight)
[0058] 1 g of Cu was added with 5 ml H 2 O while stirring and heating up to boiling. HNO 3 (3 ml; 65 vol %) was dropwise added, followed by 1 g of Ni. Further HNO 3 (3.5 ml; 65 vol %) was added followed by H 2 O up to a total volume of 10 ml. The resulting solution had a metal cation concentration of 3.277 mol/l. The solution was added with 10 ml of 2-hydroxyethylmethacrylate, 5 ml of polyethyleneglycol diacrylate and 50 mg of AIBN, then heated (80° C.) to yield a gel.
[0059] The gel was dried at 200° C. for 2 h. The resulting xerogel was ground, crashed and decomposed at 500° C. for 2 h to give a mixture of CuO, NiO and Cu 0.47 Ni 0.53 O which was characterized as follows.
[0060] FIG. 3 shows the XRD patterns of said mixture. The mean primary grain size was calculated from the XRD patterns by use of the Debye-Scherrer formula (A. R. West “Solid State Chemistry and its application” Ed. John Wiley & Sons, 1996, page 174) giving a values of 10 nm for NiO (together with the isostructural phase (Ni,Cu)O) and 8 nm for CuO. The TEM imaging was in agreement with the calculated mean primary grain size. SEM images showed that powders were weakly agglomerated each other.
[0061] The oxide mixture was reduced at 500° C. for 2 hours in H 2 (100%) to give 2.5 g of the title alloy. The XRD pattern of FIG. 3 indicates that the Ni—Cu alloy pure phase has a mean primary grain size of 16 nm.
EXAMPLE 3
Copper/Nickel/Cerium/Gadolinium Oxides Nanopowder and CU 0.47 Ni 0.53 and Ce 0.8 Gd 0.2 O 1.9 Cermet
[0062] 1.164 g of Cu was added with 5 ml of H 2 O while stirring and heating up to boiling. HNO 3 (3.5 ml; 63%) was dropwise added. 1.212 g of Ni was then added followed by HNO 3 (63%) up to a total acid volume of 4.3 ml.
[0063] The resulting mixture was added with 5.992 g. of Ce(NO 3 ) 3 ×6H 2 O, 1.370 g of Gd(NO 3 ) 3 ×6H 2 O and water up to a total volume of 15 ml to provide a solution with a metal cation concentration of 3.747 mol/l.
[0064] The resulting mixture was added with 15 ml of 2-hydroxyethylmethacrylate, 7.5 ml of polyethyleneglycol diacrylate and 100 mg of AIBN, and heated (80° C.) up to the gel formation.
[0065] The gel was dried at 200° C. for 2 h to yield a xerogel which was ground, crashed and decomposed at 500° C. for 1 h. A powder mixture (6 g) of CuO, NiO, CU 0.47 Ni 0.53 O and Ce 0.8 Gd 0.2 O 1.9 (hereinafter CGO-20) was obtained and characterized as follows.
[0066] FIG. 4 shows the XRD analysis of the powder mixture. The mean primary grain size was calculated from the XRD patterns by use of the Debye-Scherrer formula (A. R. West “Solid State Chemistry and its application” Ed. John Wiley & Sons, 1996, page 174) giving values of 10 nm for NiO (together with the isostructural phase (Ni,Cu)O), 12 nm for CuO and 5 nm for CGO-20. The TEM imaging was in agreement with the calculated mean primary grain size. Moreover, it is not possible to distinguish all phases by shape due to their intimate mixing. The powders were weakly agglomerated as from SEM images.
[0067] The powder mixture was reduced at 500° C. for 2 h in H 2 (100%) to give the title cermet. According to the XRD pattern of FIG. 4 the resulting NiCu alloy pure phase has a mean primary grain size of 8 nm, and the CGO-20 has a mean primary grain size of 6 nm.
EXAMPLE 4
La 0.60 Sr 0.40 Fe 0.80 Co 0. 20 O 3−δ Nanopowder
[0068] 1.0064 g La(NO 3 ) 3 .6H 2 O, 0.3278 g Sr(NO 3 ) 2 , 1.2596 g Fe(NO 3 ) 3 .9H 2 O and 0.2254 g Co(.NO 3 ) 2 .6H 2 O were added to 10 ml H 2 O while stirring and heating up to 50° C. The metal cation concentration of the solution was 0.776 mol/l H 2 O.
[0069] The solution was added with 10 ml of 2-hydroxyethylmethacrylate and 5 ml polyethyleneglicoldiacrylate, then heated (80° C.). 20 drops of 35% H 2 O 2 were added to initiate the gel formation.
[0070] The resulting gel was decomposed at 500° C. for 5 hours and at 700° C. for 5 hours. 1 g of the title compound were obtained and characterized as follows.
[0071] XRD of FIG. 5 showed that the sample contained a substantially single phase. The powder has a mean primary grain size of 10 nm calculated using the Debye-Scherrer formula (A. R. West “Solid State Chemistry and its application” Ed. John Wiley & Sons, 1996, page 174). The material was obtained at a sintering temperature of 500° C. lower than that previously reported (see S. Wang, T. Kato, S. Nagata, T. Honda, T. Kaneko, N. Iwashita, M. Dokiya, Solid State Ionics, 146(2002) 203-210).
EXAMPLE 5
SrFeCo 0.50 O 3+δ Powder
[0072] 0.9589 of g Sr(NO 3 ) 2 , 1.8290 g of Fe(NO 3 ) 3 .9H 2 O and 0.6588 of g Co(NO 3 ) 2 .6H 2 O were added to 10 ml H 2 O while stirring and heating up to 40-50° C. The metal cation concentration was of 1.132 mol/l. Subsequently, 10 ml of 2-hydroxyethylmethacrylate and 5 ml polyethyleneglicoldiacrylate were added. The solution was heated (80° C.). 20 drops of 35 vol % H 2 O 2 were added to initiate the gel formation.
[0073] The resulting gel was decomposed at 500° C. for 4 hours and then at 1000° C. for 6 hours. 1 g of the title compound was obtained and characterized as follows.
[0074] The XRD pattern of FIG. 6 shows that the sample is almost monophasic. It should be noted that we obtained the same material quality at 100-200° C. lower than it was reported before [R. Bredesen and T. Norby, Solid State Ionics, 129 (2000) 285].
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Process for manufacturing an electrochemical device including a cathode, an anode and at least one electrolyte membrane disposed between the anode and the cathode, wherein at least one of the cathode, the anode and the electrolyte membrane, contains at least a ceramic material.
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BACKGROUND OF THE INVENTION
The present invention relates to a digital signal reproducing apparatus suitable for reproducing digital PCM audio signals that have been recorded in the form of single helical tracks on a recording medium, one track being formed per unit time, with a rotary head.
A technique is known in which audio signals are recorded on magnetic tape in the form of helical tracks by helical scanning with a rotary head, one track being formed per unit time, and being reproduced subsequently. A digital signal recording/reproducing apparatus known as an R-DAT (rotary head type digital audio tape recorder) has been designated for recording audio signals as PCM signals and subsequently reproducing the same.
One recorded track format in an actual R-DAT system is shown in FIG. 14A, in which each of MARGIN, PLL and POSTAMBLE has a frequency of 1/2 f m (f m =9.4 MHz) and IBG has a frequency of 1/6 f m . Each of SUB and PCM is composed of a plurality of blocks, as shown in FIG. 14B. SYNC is composed of 10 bits, of which 9 bits are fixed, with the remainder assuming various patterns depending upon the pace and audio signals. SUB consists of a cyclic pattern of 8 such blocks, and PCM has 128 blocks. The numerals given in FIG. 14A represent the numbers of blocks occupied by the respective regions. The regions ATF-1 (between SUB-1 and PCM) and ATF-2 (between PCM and SUB-2) (ATF=automatic track finding) are provided to ensure that tracking control, i.e., control for allowing a rotary head to correctly scan the recorded tracks during reproduction, can be accomplished by means of the output of the head itself without employing any special head.
In R-DAT, time base compressed PCM signals are recorded in the form of helical tracks on magnetic tape by means of two rotary heads. Instead of providing a guard band between adjacent tracks, a tracking pilot signal is recorded both at the beginning and at the end of each track in a region independent of the area in which the PCM signals are recorded. During reproduction, the recorded tracks are scanned with a rotary head having a scanning width larger than the width of each track, and the output of the reproduced pilot signals from the two tracks adjacent to the track being scanned is used to control the tracking of the rotary head.
The ATF track pattern is shown in FIG. 15 and is hereinafter described with reference to the case of a drum having a diameter of 30 mm which is rotating at 2,000 rpm with the tape wound at an angle of 90° with respect to the drum.
ATF-1 and ATF-2, located respectively in the front and rear portions of each track, have a small azimuth effect signal f 1 having a low frequency of 130 kHz (=f m /72) as a tracking pilot signal. This signal is used to detect the levels of crosstalk resulting from the two tracks adjacent to the track being reproduced, so as to obtain the difference between the levels of such crosstalk as a tracking error signal.
In each of ATF-1 and ATF-2 there is recorded a sync signal for identifying the location at which the pilot signal f 1 is recorded. In the presence of crosstalk, the sync signal is unable to distinguish the current track from adjacent tracks, so it is selected in such a way that it not only has a frequency capable of producing an azimuth-effect but also affords a pattern different from that of the PCM signal. If the head having a + (plus) azimuth is designated A and the head having a - (minus) azimuth is designated as B, two different sync signals are provided to distinguish head A from head B. Stated more specifically, a sync 1 signal f 2 having a frequency of f m /18 (=522 kHz) and a sync 2 signal f 3 having a frequency of f m /12 (=784 kHz), respectively corresponding to head A and B, are recorded in predetermined positions.
In an R-DAT which does not employ an erase head, a new signal is written over the previously recorded signal. In order to enable this "overwrite" mode, an erase signal f 4 having a frequency of f m /6 (=1.56MHz) is recorded at a predetermined position to erase the previously recorded pilot signal f 1 , sync 1 signal f 2 , and sync 2 signal f 3 .
The ATF pilot signals are located at different positions on the current track and the two adjacent tracks. The level of the pilot signal on the current track (i.e., the track being scanned) differs on a time basis from the level of each of the pilot signals on the adjacent tracks, so that the three different levels can be sampled independently of each other.
Five blocks are assigned to each of the ATF regions, ATF-1 and ATF-2, and the pilot signal f 1 is recorded in two of these blocks. The sync signal f 2 is recorded in an area covering 1 or 0.5 block from the center of the position in which one of the two other adjacent tracks is recorded. The pilot signal f 1 on the other adjacent track is recorded in such a way that its center is positioned two blocks after the beginning of the sync signal recorded on the current track. A one-block sync signal is assigned to an odd-number frame, and a half-block sync signal is assigned to an even-number frame.
As described above, the sync signals to be recorded in the ATF region have different frequencies depending upon which head is used in scanning, and these sync signals also have different recording lengths in odd-number frames and even-number frames. This design enables four consecutive tracks to be distinguished from one another since they are provided with different ATF regions. Thus, the pattern of ATF regions is of the 4-track completed type, being cyclically repeated every 4 tracks.
When magnetic tape in which signals have been recorded in the format shown in FIG. 14A is played back with a rotary head, an RF signal of the type shown in FIG. 16A is reproduced from the head. If this RF signal is obtained by playback of a track with the odd-number frame (A) shown in FIG. 15, it may be passed through a bandpass filter (BPF) of 130 KHz so as to obtain a pilot signal f 1 as shown in FIG. 16B.
The signal in zone I is due to the pilot signal on the current track, and those in zones II and III result from crosstalk of the pilot signal on a track with the odd-number frame (B) and a track with the even-number frame (B), respectively. If the rotary head were scanning the current track correctly, the envelope levels of zones II and II, or the values of V II and V III indicated in FIG. 16C should be equal to each other. However, if a tracking deviation occurs, V II is not equal to V III (V II ≠V III ), and the amount and direction of the deviation of the rotary head with respect to the current track can be determined by the magnitude and polarity of the difference between V II and V III . Therefore, by actuating a capstan servo according to the difference between V II and V III so as to effect fine adjustment of the tape speed, the rotary head can be controlled to travel correctly on the current track.
However, as described before, R-DAT does not employ an erase head, and subsequent recording is carried out by overwriting. Therefore, it is sometimes not possible to generate a correct error signal upon correct detection of the sync signal and sampling of the value V II and V III .
Specifically, in R-DAT, recording may be performed with the range of ± two blocks from the center of the PCM region. Further, pilot signal f 1 (=130 kHz) is recorded at a level slightly lower than the recording levels of the reminder signals. This is done in order to have the previously recorded pilot signal erase by the erasing signal, since the signal having a lower frequency is recorded on the tape with a deeper recording level. However, with the pilot signal f 1 having a lower recording level, the previously recorded sync signal tends to remain unerased when the pilot signal f 1 is newly recorded in place of the sync signals f 2 and f 3 which have previously been recorded.
More specifically, when new recording is carried out with a displacement in the forward direction with respect to the previous recording, there is no problem, since the sync signal of the new recording always precedes the sync signal of the previous recording which has remained unerased. However, a problem will be caused in the case in which the sync signals of the new recording are displaced in the backward direction and the unerased sync signal precedes the new sync signal. An example of such a problem is that the displacement occurs in the backward direction by an amount in the range of one to two blocks. Partial or entire sync signals f 2 and f 3 which previously have been recorded remain unerased in the portion of the pilot signal f 1 in even-number frame (A) and odd-number frame (A) with respect to ATF-1 and in even-number frame (B) and odd-number frame (B) with respect to ATF-2.
If such a problem occurred, sampling would be implemented to sample a level of a frequency component of the pilot signal contained in the reproduced RF signal in response to the previously recorded sync signal. This pilot signal should have been at a crosstalk level of the sampling signal in one adjacent track. However, the sampled frequency component actually is that of the pilot signal of the current track, and the level obtained by sampling is extremely large. Thereafter, the frequency component of the pilot signal contained in the reproduced RF signal coming after two blocks is sampled, the difference in level of this sampled value and the sampled value obtained two blocks before is computed, and the capstan servo is controlled in accordance with this level difference as the amount of track deviation. However, since the previously sampled value is not the crosstalk level of the adjacent track but the level of the current track, an extremely large level difference compared with the actual track deviation is obtained. When such a phenomenon occurs, the capstan servo is disturbed and the tape travel is badly affected.
Although description has been provided for the case in which the previous sync signal remains unerased in the portion of the pilot signal which has been newly recorded, the sync signal may otherwise remain as noise as a result of incomplete erasure of the sync signal by the erase signal.
SUMMARY OF THE INVENTION
The present invention has been made in view of the foregoing deficiencies, and thus it is an object of the invention to provide a digital signal reproducing apparatus which does not operate erroneously even if the previously recorded sync signal remains unerased as a result of erasure through overwriting.
It is another object of the present invention to provide a digital signal reproducing apparatus which is capable of performing stable capstan servo control in response to crosstalk difference between the pilot signals on two adjacent tracks as obtained by the respective rotary heads.
It is still another object of the present invention to provide a digital signal reproducing apparatus in which tracking control can be correctly carried out even if a previously recorded sync signal remains unerased as a result of being overwritten. Further, in accordance with the present invention, when it is judged that the levels of the pilot signal frequency components which are the outputs of the respective rotary heads are not in a particular relationship with respect to a predetermined level, detection of the sync signal is prohibited so as to not to cause erroneous capstan servo control because of the difference in level between the pilot signal on the current track and the signal detected after a predetermined period of time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a system block diagram showing the general layout of a digital signal reproducing apparatus according to one embodiment of the present invention;
FIG. 2 is a block diagram showing the essential parts of the apparatus of the present invention;
FIGS. 3A-3H, 4a-4c, and 4A-4G are timing charts showing the waveforms of signals generated in various parts of the system shown in FIG. 2;
FIG. 5 is a circuit diagram showing a specific configuration of part of the system shown in FIG. 2;
FIGS. 6A-6J are timing charts showing the waveforms of signals generated in various parts of the system shown in FIG. 5;
FIG. 7 is a block diagram showing a specific configuration of another part of the system shown in FIG. 2;
FIGS. 8A-8G and 9A-9E are timing charts showing the waveforms of signals generated in various parts of the system shown in FIG. 7;
FIG. 10 is a circuit diagram showing a specific configuration of still another part of the system shown in FIG. 2;
FIGS. 11A-11J are timing charts showing the waveforms of signals generated in various parts of the system shown in FIG. 10;
FIGS. 12 and 13 are circuit diagrams showing partial modifications of the system shown in FIG. 2;
FIGS. 14A and 14B show a track format and a block format used in R-DAT;
FIG. 15 is a diagram showing an ATF track pattern used n R-DAT; and
FIGS. 16A-16C are diagrams illustrating the principle of tracking control with the track pattern shown in FIG. 15.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
One preferred embodiment of the present invention now will be described with reference to the accompanying drawings.
FIG. 1 is a system block diagram showing a digital signal recording/reproducing apparatus according to one embodiment of the present invention. In the figure, a rotary drum 1 has a diameter of 30 mm and is equipped with two rotary heads 1A and 1B spaced apart by 180°, head 1A recording and reproducing (+) azimuth and head 1B recording and reproducing (-) azimuth. Pulse generators (PG) PGA and PGB are provided diametrically opposite positions midway between the heads 1A and 1B.
A crystal oscillator 2 generates a basic clock f m having a frequency of 9.4 MHz, with the basic clock f m being supplied to various parts of the system. A system controller 3 outputs a PB/REC signal for performing such operations as on-off control on a toggle switch unit 4 composed of switches SW1 and SW2. A reference signal generator 5, in response to the basic clock f m fed to its CK input, generates reference signals having frequencies of X Hz (66 Hz assuming the use of 2 PGs), Y Hz (which varies according to the number of FGs in the capstan motor), and Z Hz.
A drum servo 6 is controlled by system controller 3 and, in response to the reference signal X Hz, performs servo control on the rotation of a drum motor. A reel servo 7 also is controlled by the system controller 3 and, in response to the reference signal Z Hz, performs servo control on the rotation of a reel motor. A capstan servo 8 also is controlled by the system controller 3 and performs servo control on the rotation of a capstan motor either in response to the reference signal Y Hz in a recording mode where the switch 4 is placed on the side of contact b or on the basis of the amount of tracking deviation in a playback mode where the switch 4 is on the side of contact a.
An HSWP (A/B) signal generator 9, in response to the pulses from the two PGs on the drum 1, generates an HSWP (A/B) signal for switching A head 1A to B head 1B and vice versa. The HSWP (A/B) signal, which assumes a high (H) level when A head is scanning and a low level (L) when B head is scanning is supplied to various parts of the system.
A phase inversion detector circuit 10 receives the basic clock f m (fed to CK input) and HSWP (A/B) as inputs and produces an output that is supplied to the S input of an initial flag latch 11. The initial flag latch 11 receives at its R input a CY output from an initial counter 12; the Q output of the latch 11 is supplied to the R input of the initial counter 12.
A table 13 outputs a threshold value to the initial counter 12 under the control of the PB/REC signal issued from the system controller 3. The CY output of the initial counter 12 becomes high (H) in accordance with the count of the set value. The CY output is applied to the encoding data processing unit 18 via the AND gate 13b which is enabled or disabled in response to the PB/REC signal applied to the AND gate 13b via the inverter 13a. The CY output of the initial counter 12 is further applied to the S input of the head touch window flag latch 14 via the AND gate 13c which is enabled or disabled in response to the PB/REC signal.
The head touch window flag latch 14 generates a window for prohibiting the detection of head touch as long as noise is produced when head switching is effected. The Q output of the latch 14 is fed as an ON signal into a decoding data processing unit 17 and the R input of the latch 14 is fed with a clear signal from the unit 17.
A reproducing amplifier 15 amplifies the signals from rotary heads 1A and 1B which send the amplified signals to the decoding data processing unit 17 to be described below. A recording amplifier, in response to the HSWP (A/B) signal, receives data to be recorded from the encoding data processing unit 18 (to be described below) and supplied it to the rotary heads 1A and 1B via switch SW1.
The decoding data processing unit 17 extracts data from the RF signal from the reproducing amplifier 15 and sends it to a D/A converter unit after performing the necessary operations such as 10/8 conversion (demodulation), de-interleaving, and error correction. At the same time, the unit 17 performs other operations, such as head touch detection, ATF sync detection and tracking error detection, on the extracted data and supplies error signals to the capstan servo 8 from a tracking deviation signal generator section 17a.
The encoding data processing unit 18 performs the necessary processing operations on A/D converted data such as interleaving, parity addition, 8/10 conversion and ATF signal addition, and supplies the processed data to the recording amplifier 16.
The system having the above-described configuration performs a recording operation when the PB/REC signal from the system controller 3 is at a low (L) level. When the PB/REC signal is "L", switch 4 is placed on the side of contact b and the capstan servo 8 is supplied with the reference signal Y Hz from the reference signal generator 5, whereupon capstan servo as referenced to the signal Y Hz is actuated to perform tracking control.
As the drum 1 rotates, PGA and PGB generate pulses and in response to these pulses, the HSWP (A/B) generator 9 produces an HSWP (A/B) output signal which assumes a "H" level when A head 1A is scanning and a "L" level when B head 1B is scanning. The HSWP (A/B) signal is fed into the phase inversion detector circuit 10 and when the level of this signal changes, or when the circuit 10 has detected a head change, its output is maintained at a "H" level for one basic clock pulse period.
When the output of the phase inversion detector circuit 10 has risen from a "L" to "H" level, the initial flag latch 11 is set and its Q output becomes high, whereupon the initial counter 12 starts a counting operation. In the embodiment under discussion, the counter 12 counts the number of basic clocks f m corresponding to a given period equivalent to 3.75 ms in response to a set value supplied from a table 13, when the CY output of the counter rises to reset the initial flag latch 11 while at the same time, the high CY output is applied to the encoding data processing unit 18 as a recording start signal. In response to this recording start signal, the encoding data processing unit 18 produces data to be recorded in a predetermined format.
When the PB/REC signal from the system controller 3 is at a high (H) level, the switch 4 is placed on the side of contact a and the rotary heads 1A and 1B are connected to the reproducing amplifier 15 while the RF signal is fed to the decoding data processing unit 17.
The operation of the capstan servo 8 is referenced to the amount of tracking deviation supplied from the decoding data processing unit 17. The amount of tracking deviation is an ATF error signal that is associated with the difference between the levels of amplitude of crosstalk of pilot signals from the two tracks adjacent to the track being scanned. The details of this signal will be given later in this specification.
The HSWP (A/B) signal generator 9 and the phase inversion detector circuit 10 will operate in a playback mode in the same manner as in a recording mode. The initial counter 12 operates as a playback mode counter in response to the set value supplied from the table 13, in which the level of the CY output of the counter 12 becomes high when the counts become equivalent to a certain value, say, 100 μs/1 ms. This is in order to ensure that the head touch operation to be described later in this specification will be prohibited as long as noise is produced when a head change is effected. It also is to ensure that, after the lapse of the given period specified above, the high CY output is sent through and AND gate 13c to the head touch window flag latch 14, which then is set to bring its Q output to a high level and to produce an ON signal for head touch detection. In response to the ON signal from the latch 14, the decoding data processing unit 17 detects the occurrence of a head touch, or the generation of an RF signal upon contact between tap T and head 1A or 1B, and as a result of this detection, the head touch window flag latch 14 is cleared and the ON signal returns to a low level.
The details of the portion of the decoding data processing unit 17 which is specifically related to tracking control are hereinafter described with reference to a block diagram shown in FIG. 2. The circuit shown in FIG. 2 is roughly divided into two portions, an analog portion that is shown above the one-short-and-one-long dashed line and digital portion shown below that line. The analog portion is composed of the reproducing amplifier 15, a bandpass filter (BPF) 101, an envelope detector 102, a first sample-and-hold (S/H) circuit 103, a second S/H circuit 104, a comparator 107, a differential amplifier 108, and a half-fixed resistor VR.
The digital portion is composed of the crystal oscillator 2, a head touch detector circuit 201, a sync detector circuit 202, an ATF timing generator 203, a reproducing flag latch 204, a system counter 205, a timing generator 206, a half-frequency divider 207, an ATF initial flag latch 208, a power-on reset circuit 209, a latch circuit 210, a protective counter 211, noise flag latch 212, a latch 213, an error detection counter 214, a sampling counter 215, and OR gates 216 and 217.
The analog portion is first described. The reproducing amplifier 15 receives at its input a RF signal from the rotary heads 1A and 1B (FIG. 1) and the output of the amplifier is supplied to the BPF 101, head touch detector circuit 201, and the sync detector circuit 202.
The BPF 101 transmits only the 130 kHz component of the RF signal and supplies it to the envelope detector 102, which performs envelope detection on the 130 kHz component and applies its output to the input of the S/H circuit 103, the (+) input of the differential amplifier 108, and another input of the comparator 107.
The S/H circuit 103 samples and holds the output of the envelope detector 102 in response to a sampling signal SP 1 that is applied to its C input from the sync detector circuit 202. That held output thereafter is applied to the (-) input of the differential amplifier 108. What is sampled and held by the S/H circuit 103 is the DC level of crosstalk of the pilot signal from one of the two tracks adjacent to the track being scanned. The output of the envelope detector 102 also passes to an input of the comparator 107.
The S/H circuit 104 receives at its input the output signal g from a differential amplifier 108. This signal g is sampled and held by the circuit 104 in response to a sampling signal SP 2 from the ATF timing generator 203, and thereafter is supplied to the capstan servo 8 (FIG. 1) as an ATF error signal which indicates the difference between the DC levels of crosstalk from the two adjacent tracks.
The differential amplifier 108 determines the difference between the output of the envelope detector 102 applied to its (+) input and the output of the S/H circuit 103 applied to its (-) input and feeds the difference of the S/H circuit 104. In other words, when the envelope detector 102 produces as its output the DC level of crosstalk from the other adjacent track, the amplifier 108 produces as its output the amount of tracking deviation, or the difference between the levels of crosstalk from the two adjacent tracks.
The digital portion of the circuit shown in FIG. 2 now will be described. Upon receiving an ON signal from the head touch window flag latch 14 (FIG. 1) and the basic clock f m , the head touch detector circuit 201 detects the reception of an ATF signal and supplies a signal to the S input of the reproduction flag latch 204. The details of this operation will be shown later in this specification.
The sync detector circuit 202 receives at its inputs the RF signal, the HSWP (A/B) signal, an ATF window set signal from the timing generator 206, an ATF window off signal from the OR gate 217, a noise signal from the noise flag latch 212, the basic clock f m from the crystal oscillator 2, and an enable clear signal from the OR gate 216, and produces a sampling signal SP1, an enable signal and a detection pulse signals its outputs. The sampling signal SP1 is sent to the C input of the S/H circuit 103 and to the R input of the latch 210. Each of the enable signal and the detection pulse signal is sent to the ATF timing generator circuit 203. After converting the RF signal to a digital signal, the sync detector circuit 202 detects the beginning of the sync pattern SY1 of rotary head 1A and that of the sync pattern SY2 of rotary head 1B so as to produce a sampling signal SP1 as an output, and thereafter outputs detection pulse signals in response to sequentially detected sync signals. The details of the operation of the sync detector circuit 202 also will be given later in this specification.
The ATF timing generator 203 receives at its inputs the OK signal from the comparator 107, an ODD/EVEN signal coming from the Q output of the half-frequency divider 207, an initial signal coming from the Q output of the ATF initial flag latch 208, an enable signal and a detection pulse signal from the sync detector circuit 202, a rear/front signal from the timing generator 206, an enable clear signal from the OR gate 216, and the basic clock f m from the crystal oscillator 2, and produces sampling signals SP2, an error detection signal, and an ATF END signal at its outputs. The sampling signal SP2 is fed to the C input of the S/H circuit 104 and to the S input of the ATF initial flag latch 208; the error detection signal is fed to the S input of latch 210, to one output of the OR gate 216, and to the CK input of the error detection counter 214; and an ATF END signal is fed to one input of each of the OR gates 216 and 217.
The ATF timing generator 203 receives an enable signal from the sync detector circuit 202 and when the level of said signal is high, a timer counter (not shown) for timing generation is enabled. At the same time, the generator 203 receives a detection pulse signal from the sync detector circuit 202, and when the number of detection pulses counted within a specified time exceeds a specified value, the generator 203 outputs an error detection signal when the detection pulse counts are below the specified value or if the OK signal coming from the comparator 107 is at a low (L) level. The details of the operation of the ATF timing generator 203 will also be described later in this specification.
For producing the basic clock f m , the crystal oscillator 2 oscillates at 9.4 MHz which is the rate of transmission of channel bit data by an R-DAT. The basic clock f m produced by the oscillator 2 is applied to the CK input of each of the head touch detector circuit 201, sync detector circuit 202, ATF timing generator 203, system counter 205, and the protective counter 211.
Each of the latches 204, 208, 210 and 313 is composed of an R-S flip-flop whose Q output becomes high in response to the rising edge of its S input and becomes low in response to the rising edge of its R input.
The reproduction flag latch 204 receives the output of the head touch detector circuit 201 and an END signal from the timing generator 206 at the S and R inputs, respectively, and the Q output of the latch 204 is supplied to the R input of the system counter 205. The system is in a relay mode when the Q output of the latch 204 is at a high level.
The system counter 205 receives the Q output of the reproduction flag latch 204 and the basic clock f m at the R and CK inputs, respectively, and the outputs Q O -Q x of the counter 205 are fed into the timing generator 206. The function of the system counter 205 is to indicate the approximate positions at which various signals are recorded on the tracks.
In response to the Q 1 -Q X outputs from the system counter 205, the timing generator 206 generates an ATF window set signal, a rear/front signal, a window clear signal and an END signal at its outputs. The ATF window set signal is supplied to the sync detector circuit 202, the rear/front signal to the ATF timing generator 203, the window clear signal to the OR gate 217, and the END signal to the R input of the reproduction flag latch 204. The timing generator 206 decodes the outputs of the system counter 205 and generates the necessary timing signals for various parts of the system.
The half-frequency divider 207 receives an HSWP (A/B) signal at the CK input and halves its frequency to produce an ODD/EVEN signal at the Q output, which is supplied to the ATF timing generator 203. The R input of the half-frequency divider 207 is fed with the Q output of the ATF initial flag latch 208.
The ATF initial flag latch 208 receives a sampling signal SP2 from the ATF timing generator 203 at the S input and a signal from the power-on reset circuit 209 at the R input. The Q output of the latch 208 is fed to the R input of the half-frequency divider 207 and to the ATF timing generator 203. The ATF initial flag latch 208 generates a flag indicating the application of capstan servo by ATF.
The power-on reset circuit 209 produces a high (H) output when power is on. The latch 210 receives an error detection signal from the ATF timing generator 203 as its S input, and a sampling signal SP1 from the sync detector circuit 202 at its R input. The Q output of the latch 210 is fed to the R input of the protective counter 211. The Q output of the latch 210 becomes high when it detects an error and is reset in response to the reception of a sampling signal SP1.
The protective counter 211 performs counting for a given period after error detection; only when its R input is at a high level does the counter 211 counts the number of basic clocks f m applied to the CK input, and the counter is cleared when the level of the R input becomes low. The R input of the counter 211 is fed with the Q output of the latch 210, and its CY output is fed to an input of the OR gate 217.
The noise flag latch 212 stores temporarily the result of checking to whether the system is noisy in a replay mode. The latch 212 is composed of a D flip-flop, in which the D input is fed with the Q output of the latch 213 and the CK input with the CY output of the sampling counter 215, with the Q output being supplied as a noise signal to the sync detector circuit 202.
The latch 213 receives the CY output of the error detection counter 214 at its S input, and the CY output of the sampling counter 215 at its R input, with the Q output being supplied to the D input of the noise flag latch 212.
The error detection counter 214 receives the error detection signal from the ATF timing generator 203 at its CK input, and the CY output of the sampling counter 215 at its R input, with the CY output of the counter 214 being supplied to the S input of the latch 213. The counter 214 counts the number of times the sampling signal SP1 was detected erroneously in a given period, and when the number exceeds a predetermined value, the CY output of the counter 214 becomes high.
The sampling counter 215 receives an HSWP (A/B) signal at its CK input, and its CY output is supplied to each of the R input of the error detection counter 214, the R input of the latch 213, and the CK input of the noise flag latch 212.
The OR gate 216 is fed with the error detection signal and ATF END signal from the ATF timing generator 203, as well as the CY output of the protective counter 211. The gate produces as its output an enable clear signal which is sent to both the sync detector circuit 202 and the ATF timing generator 203.
The OR gate 217 receives at its three inputs a window clear signal from the timing generator 206, an ATF END signal from the ATF timing generator 203, and the CY output from the protective counter 211, and produces at its output an ATF window off signal which is sent to the sync detector circuit 202.
In the system having the configuration described above, the reproduced RF signal is supplied through the reproduction amplifier 15 to the head touch detector circuit 201 and sync detector circuit 202, as well as to the BPF 101 which transmits only the 130 kHz component of the RF signal. The amplitude level of the 130 kHz components is converted to a DC level in the envelope detector 102 and thereafter is applied to the input of the S/H circuits 103, and to the (+) input of the differential amplifier 108.
The envelope detector 102 outputs in order on a time basis the DC level of the amplitude of the crosstalk of a pilot signal from one adjacent track and that of the crosstalk of a pilot signal from the other adjacent track. The detector 102 also outputs the DC level of the amplitude of the pilot signal from the current track either before or after the pilot signals on the two adjacent tracks.
The S/H circuit 103 samples and holds the DC level of the pilot signal on one adjacent track at the timing determined by the sampling signal SP1 from the sync detector circuit 202. The sample-and-hold level of crosstalk from the one adjacent track is applied to one input of the differential amplifier 108. As mentioned above, the output of the envelope detector 102 goes to the other input of the differential amplifier 108.
When the level of the input that is supplied to the comparator 107 via the half-fixed register VR is higher than the input from the S/H circuit 103, the comparator 107 produces a high (H) OK signal, indicating that the level of crosstalk from one adjacent track has been sampled correctly. The opposite case indicates that the level of the current track has been sampled. Therefore, a low (L) OK signal produced by the comparator 107 indicates erroneous detection of the sync signal. The OK signal produced from the comparator 107 is supplied to the ATF timing generator 203.
When the envelope detector 102 outputs the DC level of the amplitude of crosstalk from the other adjacent track, the differential amplifier 108 receives at the (-) input the DC level of the amplitude of crosstalk from one adjacent track, thereby producing at its output the difference between the DC levels of crosstalk from the two adjacent tracks. The difference provided the amount of tracking deviation, which is fed to the input of the S/H circuit 104.
The S/H circuit 104 samples and holds an amount of deviation for the two adjacent tracks in response to the sampling signal SP2. The output of the S/H circuit 104 is supplied to the capstan servo 8.
FIGS. 3A-3H are timing charts that show the waveforms for the signals generated in various parts of the system as a result of the operations described above, with the individual waveforms being keyed to the symbols attached to the respective parts.
The level of the HSWP (A/B) signal whose waveform is depicted in FIG. 3B becomes high (H) when reproduction is achieved by A head 1A with (+) azimuth, and becomes low (L) when reproduction is made with BV head 1B having (-) azimuth. When there is a head change, the phase of the HWSP (A/B) signal is inverted. Upon phase inversion, the level of the Q output of the initial flag latch 11 (FIG. 1) becomes high and the initial counter 12 (FIG. 1) is actuated. The level of the CY output of the initial counter 12 becomes high when the tape passes a noisy portion, and as a result, the initial counter 12 sets the head touch window flag latch 14 (FIG. 1) and brings its Q output to a high level. When the level of the Q output of the latch 14 becomes high, the head touch detector circuit 201 is actuated.
When detecting the reproduction of RF signal due to contact between tape and head, the head touch detector circuit 201 produces a high (H) output, which sets the reproduction flag latch 204 and brings its Q output to a high level. When the level of the Q output of the latch 204 becomes high, the system counter 205 starts a counting operation. With this point of time being used as a reference, the system counter 205 allows estimation of the approximate positions at which the individual signals are recorded on the tape. In a response to Q 0 -Q x outputs from the system counter 205, the timing generator 206 supplies the sync detector circuit 202 with an ATF window set signal a little before the positions at which ATF-1 and ATF-2 are recorded.
After converting the RF signal into a digital signal, the sync detector circuit 202 detects sync signal 1 (=f 2 ) generated when reproduction is achieved by A head 1A made with B head 1B. Detection of these sync signals by circuit 202 is based on the following relationship between frames and the patterns of the sync signals:
______________________________________Frame f.sub.2 (A) f.sub.3 (B)______________________________________ODD (1 block) 20 waves/40 signals 30 waves/60 signalsEVEN (0.5 block) 10 waves/20 signals 15 waves/30 signals______________________________________
When detecting three consecutive sync signals in a normal mode or four consecutive sync signals in a noisy mode, the sync detector circuit 202 outputs a sampling signal SP1 to the S/H circuit 103 so that it will sample and hold the level of crosstalk of the pilot signal f 1 from one adjacent track. At the same time, the sync detector circuit 202 supplies an enable signal to the ATF timing generator 203. Upon each detection of consecutive sync signals, the sync detector 202 supplied a pulse detection signal to the ATF timing generator 203.
In response to a high (H) enable signal from the sync detector circuit 202, the sync detection counter and timer in the ATF timing generator 203 will be actuated. At a time 0.25 blocks after the outputting of the sampling signal SP1 from the sync detector circuit 202, the ATF timing generator 203 checks to see if the crosstalk from adjacent tracks has been correctly sampled and held at the timing determined by the sampling signal SP1. Then, after 1.25 blocks, the timing generator 203 checks to see if the number of sync signals detected exceeds a specified value. If the result is affirmative, it is concluded that detection of sync signals has been effected correctly and after 2 blocks, the generator 203 supplies a sampling signal SP2 to the S/H circuit 104, which samples and holds the difference between the levels of crosstalk from the two adjacent tracks and supplies its output to the capstan servo 8 as the amount of tracking deviation.
If the above sequence of operations has been performed correctly, the ATF timing generator 203 outputs an ATF END signal which is supplied as an enable clear signal to the sync detector circuit 202 and back to the ATF timing generator 203 via the OR gate 216. The ATF END signal is also passed through the OR gate 217 to be supplied to the sync detector circuit 202 as a window off signal, in response to which the window for sync detection by the circuit 202 disappears to as to stop the operation of detecting the pattern of sync signals.
In the case of erroneous sampling, that is, if it is found that the level of the pilot signal on the current track has been sampled-and-yield by the S/H circuit 103, with the level of the output from the comparator 107 being low, or if the number of sync signals detected is below a specified value, both the error detection signal and the Q output of the latch 210 are brought to a high level so that the protective counter 211 performs a counting operation while the error detection counter 214 counts down by "1". When the level of the error detection signal becomes high, the enable clear signal which is sent through the OR gate 216 to the sync detector circuit 202 an the ATF timing generator 203 is again brought to a high level. When the level of the enable clear signal becomes high, the sync detector circuit 203 restarts the sync detection operation and if a predetermined number of sync signals have been detected, the circuit 203 outputs another sampling signal SP1. At the same time, the ATF timing generator 203 sets the sync detection counter and timer to its initial state. If the sync detector circuit 202 outputs another sampling signal SP1 as mentioned above, the latch 210 is reset and its Q output becomes low so that the protective counter 211 is set to its initial state.
When a specified time (2.5 block periods) has passed after the outputting of one error detection signal (i.e., when the level of the CY output of the protective counter 211 has become high), the enable clear signal that is sent through the OR gate 216 to the sync detector circuit 202 and the ATF timing generator 203 is brought to a high level so as to stop the operation of these components.
The sampling counter 215 counts down by "1" in response to the rising edge of the HSWP (A/B) signal. This is in order to control the tape over a certain length in such a way that if error detection effected in that period exceeds a specified value, the level of the CY output of the error detection counter 214 becomes high, whereupon the Q output of the noise flag latch 213 is brought to a high level so as to inform the sync detection circuit 202 that the tape is noisy.
In response to a window clear signal coming from the timing generator 206, the level of the ATF window off signal supplied to the sync detector circuit 202 through the OR gate 217 becomes high; this provision is made to deal with large dropouts.
FIGS. 4a-4c and 4A-4G are timing charts that show the approximate waveforms of the signals generated in various parts of the digital potion of the system after the initial flag latch 11 is set in a playback mode, with the individual waveforms being keyed to the symbols used in FIG. 2.
FIG. 5 is a block diagram showing a specific configuration of the head touch detector circuit 201 described on the foregoing pages. In FIG. 5, a comparator 1--1 receives an RF signal at one input, and a reference voltage +V at the other input, and a comparator 1-2 receives the RF signal at one input, and a reference voltage -V at the other input. The outputs of the two comparators are connected to the D input of a D flip-flop (FF) 1-5 through an OR gate 1-3 and a resistor 1-4, and to ground through a capacitor 1-6. The D FF 1-5 receives basic clock f m at the CK input, and its Q and Q outputs are connected to one input of an AND gate 1-7 and one input of an AND gate 1-8, respectively.
A basic clock f m is fed to the other input of the AND gate 1-7 and to a second input of AND gate 1-8. The output of AND gate 1-7 is connected to the UP input of an up-down counter 1-9, and the output of AND gate 1-8 is connected to the DOWN input of the counter 1-9. The Q A -Q D outputs of the up-down counter 1-9 are connected to a third input of the AND gate 1-8 through an OR gate 1-10, and the CY output of the counter 1-9 is connected to the CK input of a D FF 1-11. The D input of the D FF 1-11 is connected to Vcc and its Q output provides the output of the touch detector circuit 201.
The R input of each of the up-down counter 1-9 and the D FF 1-11 is fed with the Q output of the head touch window flag latch 14 (FIG. 1).
In the configuration described above, comparator 1--1 produces a high (H) output if the level of the RF signal is higher than +V, and produces a low (L) output in the opposite case. Comparator 1-2 produces a high output if the level of the RF signal is lower than -V, and produces a low output in the opposite case. Therefore, if the level of the RF signal is not within the range of ±V, the OR gate 1-3 will produce a high output.
The resistor 1-4 and capacitor 1-6 together form an integrator circuit for absorbing any noise such as a noise spike that may be present in the output of the OR gate 1-3. The output of OR gate 1-3 from which any spike noise has been rejected by the integrator circuit is applied to the D input of the D FF 1-5.
The D FF 1-5 samples the state of its D input at the timing determined by the basic clock f m applied to the CK input, and produces the sampled state at its Q output. The Q output of D FF 1-5 is an inverted version of the Q output. The Q output of the D FF 1-5 is applied to one input of the AND gate 1-7 which is fed with the basic clock f m at the other input. When the Q output of the D FF 1-5 is high, the basic clock f m is fed with to the UP input of the up-down counter 1-9 via AND gate 1-7. Therefore, the up-down counter 1-9 counts up the basic clock f m if the Q output of the head touch window flag latch 14 is high (i.e., the window is on) and if the Q output of the D FF 1-5 is high.
If the Q output of the D FF 1-5 is low, that is, if the level of the RF signal is within the range of ±V indicating that no signal to be reproduced is present, the Q output of the D FF 1-5 becomes high. In this state, if any one of the Q A -Q D outputs of the up-down counter 1-9 is high (i.e., the contents of the counter are not zero), the basic clock f m is applied to the DOWN input of the counter through the AND gate 1-8 so that the counter will count down. If, as a result of this countdown or resetting, the contents of the counter become zero, with all of the Q A -Q D outputs being at a low level, the OR gate 1-10 will produce a low output and the AND gate 1-8 is closed so that the basic clock f m will not be supplied to the DOWN input of the counter 1-9.
If, as a result of countup by the up-down counter 1-9, a carry is produced, the CY output of the counter becomes high. In response to the rising edge of the high CY output, the D FF 1-11 stores the state of its D input. Since the D input is at a high level D FF 1-11 will produce a Q output of high level.
FIGS. 6B through 6J are timing charts showing the waveforms of signals generated at various parts of the head touch detector circuit shown in FIG. 5 when it is fed with an RF signal having the waveform depicted in FIG. 6A).
In the presence of a signal to be produced, the RF signal continuously provides amplitudes exceeding the range of ±V, whereas in the absence of a signal to be reproduced (i.e., in the area where neither head contacts the tape) the RF signal seldom has amplitudes exceeding the range of ±V. The value of ±V are set in such a way that they can be clearly distinguished from noise components.
In response to an input RF signal having the waveform shown in FIG. 6A, the comparator 1--1 will produce an output having the waveform shown in FIG. 6B and the comparator 1-2 produces an output having the waveform shown in FIG. 6C. The OR gate 1-3 will produce an output having the waveform shown in FIG. 6D which is the logical sum of 6B and 6C. As is clear from FIG. 6D, the output of the gate 1-3 is incompletely gated and any undesired portions of this output are eliminated by the integrator circuit such that the D input of the D FF 1-5 is fed with a signal having the waveform shown in FIG. 6E.
As a result, a signal having the waveform shown in FIG. 6F appears at the Q output of the D FF 1-5. Since the basic clock f m passes through the AND gate 1-7 as long as the Q output remains high, and AND gate 1-7 will output a signal having the waveform depicted in FIG. 6G. A signal having the waveform depicted in FIG. 6H will appear at the output of the AND gate 1-8.
Any noise component that slightly exceeds the range of ±V and any incompletely gated portions can be rejected by the integrator circuit but a noise impulse having a large amplitude cannot be rejected by this circuit.
Signals having the waveforms shown in FIGS. 6G and 6H are applied to the UP and DOWN inputs, respectively, of the up-down counter 1-9. When a predetermined number of counts are attained, the up-down counter 1-9 will produce a carry having the waveform depicted in FIG. 6I which is sent to the CY output. In response to this event, the D FF 1-11 will store the state of its D input and produce a signal at the Q output which rises as shown in FIG. 6J.
In the manner described above, any small noise or incomplete gating can be eliminated by the integrator circuit, whereas any large noise can be rejected by the up-down counter 1-9 which achieves control of the duration of time. This provides a clear-cut distinction between the case where a signal is actually reproduced because of contact between tape and head and the case where no signal is reproduced in the absence of tape-to-head contact. In other words, head touch detection can be accomplished in a precise manner.
FIG. 7 shows a specific configuration of the sync detector circuit 202. The sync detector circuit 202 receives at its inputs an RF signal HSWP (A/B) signal, basic clock f m , ATF window set signal, ATF window clear signal, noise signal and an enable clear signal.
An ATF equalizer 2-1 that is supplied with an RF signal from the reproduction amplifier 15 (FIG. 1) emphasizes the frequency band of the ATF sync signal (400-900 kHz) and sends the thus processed RF signal to a limiter 2--2. In the limiter 2--2, the RF signal is converted to a digital signal which is high (H) if the amplitude of the input signal is greater than a specified level, and is low (L) in the opposite case.
The output of the limiter 2--2 is supplied both to the D input of a D FF 2-3 which is fed with the basic clock f m at its CK input and to one input of an EXCLUSIVE (E) OR gate 2-4. The other input of EOR gate 2-4 is fed with the Q output of the D FF 2-3 so that the combination of EOR gate 2-4 and D FF 2-3 will constitute a phase inversion detector circuit.
The ATF window set signal is supplied to the S input of an ATF window latch 2-5 that is fed with an ATF window clear signal at its R input, and an ATF window signal is produced from the Q output of the ATF window latch 2-5.
The output of the EOR gate 2-4 is supplied to the D input of a 11-stage shift register 2-6 that is fed with the basic clock f m and the ATF window signal from the latch 2-5 at its CK and R inputs, respectively. The Q1 output of the shift register 2-6 is supplied to AND gates 2-8 and 2-9 through an inverter 2-7; the Q2-Q5 outputs of the register are supplied to AND gates 2-8 and 2-9; the Q6-Q8 outputs are supplied to a NOR gate 2-10 and the AND gate 2-9; and the Q9-Q11 outputs are supplied to a NOR gate 2-11. The outputs of NOR gates 2-10 and 2-11 are supplied to AND gates 2-8 and 2-9, respectively. The AND gate 2-8 is also fed with an HSWP (A/B) signal that has been inverted by an inverter 2-12, whereas the AND gate 2-9 is fed with an uninverted HSWP (A/B) signal. The outputs of AND gates 2-8 and 2-9 are supplied to the two inputs of an OR gate 2-13.
The output of the OR gate 2-13 is supplied to the D input of a 29-stage shift register 2-14 that is fed with the basic clock f m at its CK input. The Q1 of the shift register 2-is supplied to the input of each of AND gates 2-15 and 2-20; the Q6-Q8 output of the shift register which will become high upon reception of a sync 2 signal are supplied to the inputs of an OR gate 2-12; the Q9-Q11 outputs which will become high upon reception of a sync 1 signal are supplied to the inputs of an OR gate 2-22; the Q12-Q14 outputs which will become high upon reception of a sync 2 signal are supplied to the inputs of an OR gate 2-23; the Q10-Q20 outputs which will become high upon reception of sync 1 and 2 signals are supplied to the inputs of an OR gate 2-24; and the Q27-Q29 outputs which will become high upon reception of a sync 1 signal are supplied to the inputs of an OR gate 2-25.
The output of OR gate 2-21 is supplied to the inputs of AND gates 2-16 and 2-18 and to the input of OR gate 2-26; the output of OR gate 2-22 is supplied to the inputs of AND gates 2-15 and 2-17 and to the input of OR gate 2-27; the output of OR gate 2-23 is supplied to the inputs of AND gates 2-16 and 2-18 and to the input of AND gate 2-26; the output of OR gate 2-24 is supplied to the inputs of AND gates 2-15 to 2-18 and to the input of OR gate 2-27; and the output of OR gate 2-25 is supplied to the input of AND gate 2-15. The outputs of OR gates 2-26 and 2-27 are supplied to the inputs of AND gates 2-20 and 2-19, respectively.
The AND gates 2-15, 2-17 and 2-19 are supplied with an HSWP (A/B) signal, whereas AND gates 2-16, 2-18 and 2-20 are supplied with an HSWP (A/B) signal that has been inverted by the inverter 2-12. The AND gates 2-15 and 2-16 are also fed with a noisy signal, whereas the AND gates 2-17 and 2-18 are also fed with a noisy signal that has been inverted by an inverter 2-28.
The outputs of AND gates 2-19 and 2-20 are supplied to an OR gate 2-28, and the output of the OR gate 2-28 is supplied to an AND gate 2-29 from which it is sent out as a detection pulse signal. The outputs of AND gates 2-15 to 2-18 are applied to an OR gate 2-30, and the output of OR gate 2-30 is fed to an AND gate 2-31 from which it is sent out as a sampling signal SP1 and forwarded to the S input of an ATF enable latch 2-32 which is fed with an enable clear signal at the R input. The Q output of the ATF enable latch 2-32 is both sent out as an enable signal and supplied to the input of AND gate 2-29. The Q output of the latch 2-32 is supplied to the inputs of AND gates 2-15 to 2-18 and 2-31 so as to control their gating operation.
The sync detector 202 with the foregoing configuration operates as follows. The limiter 2--2 outputs a digital signal that corresponds to ATF sync 1 and sync 2 in the RF signal, and in accordance with the phase inversion of this digital signal, one clock period of the output of EOR gate 2-4 will become low (L). Shift register 2-6 which receives the output of EOR gate 2-4 at the D input will pick up the contents of this D input in response to the rising edge of the basic clock f m which is applied to the CK input when the window signal that is supplied to the R input from the ATF window latch 2-5 is at a high level, and the picked up input is sent to the Q1 output. Upon each subsequent rising of the basic clock f m , the D input is shifted in successive stages and sent to the Q2-Q11 outputs. In other words, the shift register 2-6 delays the output of EOR gate 2-4 by 1-11 clock periods before it is sent to the Q1-Q11 outputs.
When the Q1 output is at a low level (indicating a change in its level, it is applied to AND gates 2-8 and 2-9 through inverter 2-7. When any one of the Q6-Q8 outputs has become low in level, it is passed through a AND gate 2-10 to provide one high (H) input for the AND gate 2-8. The Q2-Q5 outputs are high unless there is a change in its level. If, in this instance, the HSWP (A/B) signal is low, it is inverted by inverter 2-12 to apply a high input to the AND gate 2-8.
If the conditions described above are met, all the inputs to AND gate 2-8 are high, producing a high output. Therefore, if these conditions are not met, the output of AND gate 2-8 remains low and will not change during a minimum of 4 clock periods. Instead, the output will change during 5-7 clock periods and half the period of sync 2 signal for the case where the HSWP (A/B) is low and reproduction is effected by B head 1B is detected. In practice, the sync 2 signal has a frequency of F 3 (=784 kHz=f m /12), so the duration of time during which no change occurs in the output of AND gate 2-8 is equivalent to six clock periods but in consideration of such factors as the timing of clock pulses and jitter, a margin of ±1 clock period is allowed.
The AND gate 2-8 outputs a pulse that becomes low in level for one clock period at every half of the period of the sync 2 signal. Being processed as in the case of sync 2, the sync 1 signal having a frequency of f 2 (=520 kHz= f m /18) is detected from the output of AND gate 2-9 if the HSWP (A/B) signal is high (i.e., reproduction is effected by A head 1A). In this case, the output of AND gate 2-9 will remain unchanged for seven clock periods and changes in state during clock period 8-10.
The sync 2 signal is produced from the AND gate 2-8 when the HSWP (A/B) signal is low, and the sync 1 signal is produced from the AND gate 2-9 when the HSWP (A/B) signal is high. Each of these sync signals is passed through the OR gate 2-134 and fed to the D input of the shift register 2-14.
The 29-stage shift register 2-14 stores the state of its D input in response to the rising edge of an input clock signal and sends the memory to the Q1 output. Upon every application of a clock in subsequent stages, the memory is shifted and sent to Q2-Q29 outputs. Therefore, the state of the D input produced at the Q1-Q29 outputs has been delayed by 1-29 clock periods.
When there is a change in the Q1 output of shift register 2-14, the level of this output becomes high. If, in the case of detection of sync 2 signal (f 3 780 kHz=1/12 f M ), there occurs a change one half period before the Q1 output, the OR gate 2-21 produces a high output. If there occurs a change one period after the Q1 output, the OR gate 2-23 will produce a high output. Therefore, output of OR gate 2-26 becomes high if there is a change one half period and/or one period before the Q1 output. The output of OR gate 2-26 becomes high if there is a change one half period and/or one period before the Q1 output. The output of OR gate 2-26 is applied to the input of AND gate 2-20 together with the Q1 output of the shift register 2-14 and the HSWP (A/B) signal. The foregoing explanation can be summarized as follows: in the case of detection of sync 2, the Q1 output becomes high when the D input is delayed by one clock period after detection of sync 2 by AND gate 2-8, and if the change that has occurred one half period before Q1 output and the change that has occurred one period before Q1 output are applied simultaneously to the input of AND gate 2-20 (the first change is passed through OR gates 2-21 and 2-26 whereas the second change is passed through OR gates 2-23 and 2-26), the output of AND gate 2-20 becomes high so as to produce a high output from OR gate 2-28.
The outputs of OR gates 2-21, 2-23 and 2-24 connected to the output of 29-stage shift register 2-14 become high when sync 2 is detected, therefore, when the noisy signal is at a low level, the output of AND gate 2-18 becomes high and is passed through OR gate 2-30 and AND gate 2-31, from which it is produced as a sampling signal SP1; at the same time, the output from AND gate 2-31 is applied to the S input of ATF enable latch 2-32 so that its Q output becomes high while the Q output becomes low. The Q output of latch 2-32 not only serves as an enable signal; it is also applied to AND gate 2-29 which then produces a detection pulse signal as its output.
Also referring to the case of detection of sync 2, if the noise signal is high, the output of AND gate 2-16 becomes high and the same operations as described above will proceed.
In the case of detection of sync 1, the outputs of OR gates 2-22, 2-24 and 2-25 become high; if the noise signal is at a low level, the output of AND gate 2-17 becomes high, and if the noise signal is at a high level, the output of AND gate 2-15 becomes high. The operations that follow are the same as described in the previous paragraphs.
In short, decision of sync detection is made at either 3 or 4 points depending upon the level of the noisy signal.
FIGS. 8a-8g are timing charts showing the waveforms of the signals that are generated in various parts of the system when detecting sync 2, with the individual waveforms being keyed to the symbols used in FIG. 7.
FIGS. 9A-9E are also timing charts showing the waveforms of the signals that are generated in various parts of the system when detecting sync 1, with the individual waveforms being keyed to the symbols used in FIG. 7.
FIG. 10 shows a specific configuration of the ATF timing generator 203. The generator 203 is fed at its inputs with an ODD/EVEN signal, a basic clock f m , and HSWP (A/B) signal, an enable signal, an enable clear signal, a rear/front signal, an OK signal, an initial signal, and a pulse detection signal.
As shown in FIG. 10, a 0.25-block counter 3-1 receives an enable signal, a basic clock f m and an enable clear signal at the E, CK and R inputs, respectively. After counting 0.25 blocks equivalent to 9.5 μs, the CY output of the counter 3-1 becomes high and is fed both to the E input of a high counter 3-2 and to the C input of a decoder 3--3.
The high counter 3-2 receives a basic clock f m and an enable clear signal at the CK and R inputs, respectively, and counts up after each 0.25 blocks. The Q0-Q4 (2 0 -2 4 ) outputs of the counter 3-2 are fed into the decoder 3--3.
The decoder 3--3 decodes each of the timing signals it receives. Only when the C input is high do 0-8, 16 and 17 outputs becomes active and the 0-8 outputs will produce 0.25-2.25 block signals at intervals of 0.25 blocks while the 16 and 17 outputs produce 4- and 4.25-block signals, respectively.
The outputs of decoder 3--3 are fed into gates 3-5 to 3-10 and the 0.5-block signal is supplied both to the R input of a latch 3-12 and to the CK input of a D FF 3-13 while the 1-block signal is supplied to the CK input of a D FF 3-14.
A decoder 3-15 receives an HSWP (A/B) signal and a rear/front signal at its inputs and decodes the location of an ATF signal presently being reproduced. It produces B-ATF-1, A-ATF-1, B-ATF-2 and A-ATF-2 signals at the 0-3 outputs, respectively, which are supplied to gates 3-16 and 3-17.
A table 3-18 is fed with an HSWP (A/B) signal and an initial signal at its inputs, and in response to these signals it changes the present threshold value it has for sync detection and sets the appropriate value in a sync detection counter 3-19. Depending upon the HSWP (A/B) value, one of the two threshold values is set, one being for detection of sync 1 when reproduction is conducted with head A and the other being for detection of sync 2 when head B is in action. Each of the two threshold values occupies 50% of the number of consecutive sync patterns, provided that it occupies 60% of the number of consecutive sync 2 patterns when the initial signal is at a low level. The sync detection counter 3-19 counts the number of pulse detection signals and its CY output is supplied to the S input of a latch 3-12.
The other components of the ATF timing generator 203 are gates 3-20 to 3-27 and inverters 3-28 to 3-30.
The sampling signal SP2 appears at the output of gate 3-9; an error detection signal at the output of gate 3-26; and ATF END signal at the output of gate 3-27.
The ATF timing generator with the foregoing configuration will operate in the following manner. When the sync detector circuit 202 generates a sampling signal SP1, the 0.25-block counter 3-1 starts a counting operation in response to an enable signal and an OK signal, both becoming high in coincidence with the falling edge of SP1. The CY output of the counter 3-1 becomes high at intervals of 0.25 blocks. Decoder 3-1 decodes the state of high counter 3-2 and produces a high output only when the CY output of the counter 3-1 is high.
When the 0 output of decoder 3--3 appears (i.e., 0.25 blocks after the generation of a sampling signal SP1), the OK signal is at a high level if the sampled value of crosstalk level on an adjacent track is less than a predetermined level. Therefore, the 0 output of decoder 3--3 will not appear at the output of AND gate 3-7 which is fed with the OK signal via inverter 3--31. When the OK signal is at a low level, AND gate 3-7 will produce a high (H) output which is sent to OR gate 3-26 and delivered therefrom as an error detection signal.
When the 1 output of decoder 3--3 becomes high, the processing performed after 0.5 block periods consists of applying this high output to the L input of sync detection counter 3-19 via OR gate 3-10, as well as to the R input of latch 3-12 and to the OK input of D FF 3-13.
The D input of D FF 3-13 is fed with the CY output of sync detection counter 3-19 via latch 3-12, so after 0.5 block periods sampling is conducted by D FF 3-13 to see if the number of detection pulse signals generated exceeds a specified value. At the same time, latch 3-12 is reset and the table 3-18 sets an appropriate threshold value again in the sync detection counter 3-19.
When the 3 output of decoder 3--3 is high, the necessary processing is conducted after one block period and a D FF 3-14 which is fed at the D input with the CY output of sync detection counter 3-19 via latch 3-12 performs sampling to see if a specified number of pulses have been detected in one block period.
The combination circuit of gates 3-20, 3-21, 3-23 and inverter 3-30 determines whether a specified number of detection pulse signals have been generated based on an ODD/EVEN signal. If the Q outputs of both D FF 3-14 and 3-14 are at a high level in the case of application of an ODD signal, and if the Q output of D FF 3-13 is high in the case of application of an EVEN signal, it is concluded that a specified number of detection pulse signals have been generated and the output of OR gate 3-25 becomes high.
If the same processing is performed with the initial signal having a high level, OR gate 3-25 produces a high output via inverter 3-29 and AND gate 3-22
If the sync detection counter 3-19 fails to detect a specified number of pulse signals, OR gate 3-25 will produce a low (L) output. Therefore, if a specified number of detection pulse signals have not been detected after 1.25 block periods (i.e., the 4 output of decoder 3--3 is at a high level), OR gate 3-26 will produce a high (H) error detection signal via inverter 3-28 and AND gate 3-8.
If the 7 output of decoder 3--3 is high (i.e., after 2 block periods), the generation of a specified number of detection pulse signals and the application of an OK signal will allow a sampling signal SP2 to be produced at the output of AND gate 3-9 for effecting sampling for the other adjacent track.
If the 17 output of decoder 3--3 is high and if ATF-2 is scanned with head A while ATF-1 is scanned with head B, the generator 2-3 produces an ATF END signal via gates 3-17, 3-5 and 3-27. If the 8 output of decoder 3--3 becomes high when ATF-1 is scanned with head A while ATF-2 is scanned with head B, the decoder 3-15 will produce an ATF END signal via gates 3-16, 3-6 and 3-27.
FIGS. 11A-11J show the waveforms of the signals generated at various parts of the system during the operations described above, with the individual waveforms being keyed to the symbols attached to the respective parts.
In the above-described embodiment, comparison of the signal level which has been sampled and held in the S/H circuit 103 with a predetermined level is performed in the comparator 107 in response to the sampling signal SP1 fed from the sync detector circuit 202, and the resultant signal which is referred to as an OK signal is applied to one input of ATF timing generator 203, to thereby control the output of the sampling signal SP2 in the AND gate 3-9. Stated another way, it is determined if the difference between the signal level which has been sampled and held in response to the sampling signal SP1 and the level of a signal coming two blocks after from that sampling and holding should be sampled and held in the S/H circuit as the ATF error signal. When the signal level which has been sampled and held in response to the sampling signal is extraordinarily large, it is determined so that level is not a crosstalk of the pilot signal of one adjacent track whose level is adequate. And, it is contemplated not to produce the ATF error signal based on that extraordinary signal to thereby prevent tracking from being disturbed.
It should be noted that the circuit configuration for preventing the disturbance of the tracking is not limited to that described above but various modifications are possible as will be described hereinafter.
FIG. 12 is a circuit diagram showing one such modification in which the comparator 107 compares the output of the differential amplifier 108 with a predetermined level, whereupon the OK signal is outputted from the ATF timing generator 203. This modification is derived from the fact that the difference in level between the sampled and held signal in the S/H circuit and the signal coming two blocks after the former signal becomes extraordinary if the level of the former signal is extraordinary. Similar effects can be obtained from this modification to those obtained from the FIG. 2 circuit.
FIG. 13 is also a circuit diagram showing another modification. The comparator 107 compares the output of the S/H circuit 104 with a predetermined level, and the resultant signal is applied to the D input of the latch circuit 110. The latch circuit 110 maintains the signal state on the D input at the time when the sampling signal, which is delayed by a certain period of time by passing through the delay circuit 111, is applied to the OK input and is sent to Q output. The Q output is utilized as a control signal for the switch circuit 112. The switch circuit 112 includes two switches SW1 and SW2 which are ganged with each other. The a contacts of the switches SW1 and SW2 are connected to the output of the S/H circuit 104. The common contact of the switch SW1 and the b contact of the switch SW2 are connected to one terminal of the capacitor 113 whose other terminal is grounded. The ATF error signal is outputted from the common contact of the switch SW2.
In the circuit of FIG. 13, when the level difference which has been sampled and held in the S/H circuit 104 is normal, the switches SW1 and SW2 in the switch circuit 112 are switched to the a contact sides, thereby permitting the output of the S/H circuit 104 to output as the ATF error signal and charging the capacitor 113. When the level difference becomes extraordinary, the switches SW1 and SW2 are switched to b contact sides so as not to output the extraordinary level difference as the ATF error signal. Instead, the level having been held in the capacitor 113 is outputted as the ATF error signal.
The same effects can be achieved by the provision of another S/H circuit in place of the capacitor, in which the same level difference having been sampled and held in the S/H circuit 104 is sampled and held.
As described, in accordance with the present invention, it is decided if the level sampled in response to the sync signal is appropriate, and the control of the capstan servo is not performed if the level difference is inappropriate caused by inappropriate crosstalk level difference. Therefore, the disturbance of the capstan servo can be prevented.
Further, in accordance with present invention, since the detection of the sync signal ceases when the level of the pilot signal frequency components in the output signals of the respective rotary heads are not in a particular relationship with respect to a predetermined level, the pilot signal of the current track is not erroneously detected in response to the inerased sync signal, and so the capstan servo control is not effected so as not to cause disturbance of the capstan servo.
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A digital signal reproducing apparatus which reproduces digital PCM audio signals recorded on a recording medium in the form of single helical tracks. The apparatus is provided with at least two rotary heads for reproducing signals on the recording medium. The apparatus, however, is not provided with an erase head. Previously recorded signals are erased by overwriting, as a result of which a problem may arise in which a sync signal remains unerased. Therefore, a level of a pilot signal frequency component sampled in response to the sync signal is compared with a predetermined level to see if the sampled level is appropriate. It it is not appropriate, capstan servo control is not performed.
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BACKGROUND OF THE INVENTION
[0001] The monolithic integration of several optoelectronics devices in optoelectronics integrated circuits (OEICs) and photonic integrated circuits (PICs) is of considerable interest for the development of telecommunications systems.
[0002] In OEICs, optical devices such as lasers and electronic devices such as transistors are integrated on a single chip for high speed operation since parasitic reactance in the electrical connections can be minimized from the closely packed devices.
[0003] PICs are a subset of OEICs with no electrical components, in which only photons are involved in the communication or connection between optoelectronics and/or photonic devices. The driving forces for PICs are to improve the complexity of next-generation optical communication links, networking architectures and switching systems, such as in multiple channel wavelength division multiplexing (WDM) and high speed time division multiplexing (TDM) systems. In PICs, besides gaining from the low cost, size reduction, and increased packaging robustness, the main advantage is that all the interconnections between the individual guided-wave optoelectronics devices are precisely and permanently aligned with respect to one another since the waveguides are lithographically produced.
[0004] In the integration process, complex devices are built up from components that are very different in functionality such as light emitters, waveguides, modulators and detectors. Each component needs different material structures to achieve optimized performance. As a result, the ability to modify the bandgap energy and the refractive index of materials is important in order to realize OEICs and PICs. A number of techniques have emerged for this purpose, including growth and regrowth, selective area epitaxy or growth on a patterned substrate and quantum well intermixing (QWI).
[0005] Growth and regrowth is a complicated and expensive technique which involves growing, etching and regrowing of quantum well (QW) layers at selected areas on bulk material. These layer structures are overgrown with the same upper cladding but a different active region. This approach suffers from mismatches in the optical propagation coefficient and mismatches in the dimensions of the waveguide at the regrown interface. In addition, this process gives low yield and low throughput, and therefore adds cost to the final product.
[0006] Selective area growth utilizes differences in epitaxial layer composition and thickness produced by growth through a mask to achieve spatially selective bandgap variation. Prior to epitaxy growth, the substrate is patterned with a dielectric mask such as SiO 2 , in which slots with different widths are defined. The growth rate in the open areas depends on the width of the opening and the patterning of the mask. No growth can take place on top of the dielectric cap. However, surface migration of the species can take place for some distance across the mask to the nearest opening. The advantage of this approach is a reduction in the total number of processing steps such that essentially optimum laser and modulator multiple quantum well (MQW) sections can be accomplished in a single epitaxial growth stage. This process works well under a precisely controlled set of parameters but is difficult to manipulate in a generic fashion. In addition, this technique gives poor spatial resolution of around 100 μm, and hence the passive section generally has a relatively high loss.
[0007] QWI is based on the fact that a QW is an inherently metastable system due to the large concentration gradient of atomic species across the QWs and barriers interface. Hence, this allows the modification of the bandgap of QW structures in selected regions by intermixing the QWs with the barriers to form alloy semiconductors. This technique offers an effective post-growth method for the lateral integration of different bandgaps, refractive index and optical absorption within the same epitaxial layers.
[0008] The QWI technique has been gaining recognition and popularity for which several potential applications in integrated optoelectronics have been identified, for example bandgap-tuned electroabsorption modulators, bandgap-tuned lasers, low-loss waveguides for interconnecting components on an OEIC or PIC, integrated extended cavities for line-narrowed lasers, single-frequency distributed Bragg reflector (DBR) lasers, mode-locked lasers, non-absorbing mirrors, gain or phase gratings for distributed feedback (DFB) lasers, superluminescent diodes, polarization insensitive QW modulators and amplifiers and multiple wavelength lasers.
[0009] Current research has been focused on QWI using approaches such as impurity free vacancy induced disordering (IFVD), laser induced disordering (LID) and impurity induced disordering (IID). Each of these QWI techniques has its advantages and shortcomings.
[0010] The IFVD method involves the deposition of a dielectric capping material on the QW materials and subsequent high temperature annealing to promote the generation of vacancies from the dielectric cap to the QW materials and hence enhance the intermixing at selected areas. For instance, in GaAs-AlGaAs QW materials, SiO 2 is known to induce out-diffusion of Ga atoms during annealing, hence generating group III vacancies in the QW material. The thermal stress at the interface between the GaAs and the SiO 2 layer plays an important role. The thermal expansion coefficient of GaAs is ten times larger than that of SiO 2 . During high temperature annealing, the bonding in the highly porous SiO 2 layer deposited using plasma-enhanced chemical vapor deposition (PECVD) may be broken due to the stress gradient between the GaAs and SiO 2 film. Thus, the out-diffusion of Ga helps to relieve the tensile stress in the GaAs. These Ga vacancies then propagate down to the QW and enhance the interdiffusion rate of Ga and Al, and hence result in QWI. After the intermixing process, the bandgap in the QW material widens and the refractive index decreases.
[0011] The selectivity of this technique can be obtained using an SrF 2 layer to inhibit the outdiffusion of Ga, hence suppress the QWI process. Using this technique, devices such as multiple wavelength bandgap tuned lasers and multiple channel waveguide photodetectors have been successfully demonstrated.
[0012] Although IFVD is a successful technique when employed in GaAs/AlGaAs system, this technique gives poor reproducibility in InGaAs/InGaAsP systems. Furthermore, due to the poor thermal stability of InGaAs/InGaAsP materials, the IFVD process, which requires high temperature annealing, is found to give low bandgap selectivity in InGaAs/InGaAsP based QW structures.
[0013] Laser induced disordering (LID) is a promising QWI process to achieve disordering in InGaAs/InGaAsP QW materials due to the poor thermal stability of the materials. In the photoabsorption-induced disordering (PAID) method, a continuous wave (CW) laser irradiation is absorbed in the QW regions, thereby generating heat and causing thermal induced intermixing. Although the resulting material is of high optical and electrical quality, the spatial selectivity of this technique is limited by lateral flow to around 100 μm. A modification of the PAID method, known as pulsed-PAID (P-PAID), uses high-energy Q-switched Nd:YAG laser pulses to irradiate the InP-based material. Absorption of the pulses results in disruption to the lattice and an increase in the density of point defects. These point defects subsequently interdiffuse into the QW during high temperature annealing and hence enhance the QW intermixing rate. Though P-PAID can provide spatial resolution higher than 1.25 μm and direct writing capability, the intermixed materials give low quality due to the formation of extended defects.
[0014] Of all the QWI methods, impurity induced disordering (IID) is the only process which requires the introduction of impurities into the QW materials in order to realize the intermixing process. These impurities can be introduced through focused ion beam, furnace-based impurity diffusion and also ion implantation.
[0015] IID is a relatively simple and highly reproducible intermixing process. It has the ability to provide high spatial resolution for the integration of small dimension devices and bandgap shifts can be controlled through the implantation parameters. This technique is commonly used to achieve lateral electrical and optical confinement in semiconductors such that low threshold current and single lateral-mode operation can be obtained. Furthermore, the IID process is of considerable interest for the integration of WDM systems, such as multiple wavelength laser sources, low-loss waveguides, modulators and even detectors.
[0016] The IID effect is widely accepted to consist of two stages. The first stage is to implant impurities into the QW material. The subsequent stage is to anneal the material to induce diffusion of both impurity and point defects into the QWs and barriers, and hence interdiffusion of matrix elements between QWs and barriers. In an InGaAs/InGaAsP QW system, the interdiffusion of Group V elements from barrier to well, which results in blueshifting of the bandgap energy, are believed to be caused by the diffusion of point defects generated during the implantation process, the self-interdiffusion at elevated temperature (thermal shift), and the diffusion of the implanted species.
[0017] During implantation, impurities as well as point defects, such as Group III vacancies and interstitials, are introduced into the material in selected areas. The diffusion of these point defects and impurities at elevated temperature enhances the interdiffusion rate between the QWs and barriers and hence promotes intermixing after annealing. Under the influence of injected impurities, the compositional profile of the QW is altered from a square to a parabolic-like profile. As a result, after the interdiffusion process, the local bandgap increases and the corresponding refractive index decreases.
[0018] Using the IID technique, selective area intermixing across a wafer can be obtained by using an SiO 2 implant mask with various thicknesses. However, this technique involves multiple lithography and etching steps which complicate the fabrication process.
[0019] A paper entitled “Integration process for photonic integrated circuits using plasma damage induced layer intermixing”, Electronics Letters, Volume 31, 449, 1995, by B S Ooi, A C Bryce, and J H Marsh, describes a quantum well intermixing process based on reactive ion bombardment damage. In this technique, a high RF power, and hence high damage, H 2 plasma process was used to introduce point defects on the surface of samples which were then annealed to diffuse the point defects into the QW region. The plasma exposure was performed using a parallel plate reactive-ion etching (RIE) machine. Similarly, L M Lam et al, in a paper entitled “Plasma Immersion Ar + Ion Implantation Induced Disorder in Strained InGaAsP Multiple Quantum Wells”, Electronic Letters, Volume 34, No. 8, 16 April 1998, disclose a plasma immersion ion implantation process that uses an RIE machine. In each of these techniques, the QWI process is based on ion bombardment damage and requires multiple cycles to affect fairly modest degrees of bandgap shift.
[0020] The ability to control the bandgap across a III-V semiconductor wafer is a key requirement for the fabrication of monolithic PICs. The absorption band edge of QW structures needs to be controlled spatially across a wafer to allow the fabrication of integrated lasers, modulators, and low-loss waveguides. Although QWI techniques offer great advantages over growth and regrowth and selective epitaxial growth techniques for the bandgap engineering process, the spatial control of conventional QWI techniques is indirect and complicated.
[0021] The explosive growth of Internet traffic, multimedia services and high-speed data services has exerted pressure on telecommunications carriers to expand the capacity of their networks quickly and cost effectively. Carriers normally have three options to expand capacity, ie install new fibers, increase the bit rate of the transmission system, or employ wavelength division multiplexing (WDM). While the first option has problems of high cost and right-of-way and the second option has limited growth potential because of inherent system limitations, the third option is therefore very attractive because it is capable of manifold increase of the network capacity at a modest cost.
SUMMARY OF THE INVENTION
[0022] According to the present invention, a method of manufacturing a photonic integrated circuit comprising a compound semiconductor structure having a quantum well region, in which the method comprises the steps of irradiating the structure using a source of photons to generate defects, the photons having an energy (E) at least that of the displacement energy (E D ) of at least one element of the compound semiconductor, and subsequently annealing the structure to promote quantum well intermixing.
[0023] The preferred radiation source is a plasma, although there are a number of sources of high energy photons that can be used. Suitable plasma sources include those generated using an electron cyclotron resonance (ECR) system, an inductively coupled plasma (ICP) system, a plasma disk excited by a soft vacuum electron beam, and plasma soft x-ray (SFR) devices. Other suitable sources of high energy radiation include electrical gas discharge devices, excimer lasers, synchrotron devices, flash x-ray devices and gamma ray sources.
[0024] The method may include the step of masking a portion of the structure to control the degree of radiation damage. In this manner, the mask may be adapted to prevent intermixing entirely. However, preferably the structure is masked in a differential manner to selectively intermix the structure in a spatially controlled manner by controlling the exposure of portions of the structure in a predetermined manner.
[0025] There are a number of suitable forms of exposure masks, including binary masks, phase masks, gray masks, dielectric or metal masks, and photoresist masks. The spatial control of intermixing is advantageously controlled using a variable profile mask pattern. Our co-pending International patent application number (Agent's reference PJF01075WO) describes a method for patterning a structure by exposing a layer of photoresist through a gray scale mask. The degree of quantum well intermixing is controlled in a spatially selective manner in dependence on the optical transmittance characteristics of the gray scale mask. This technique is especially suitable for use in the present invention since it allows a mask to be constructed that can control the exposure of the structure to high energy radiation. The photoresist mask pattern may be used alone to control the degree of exposure or it may instead be used to transfer a mask pattern to an underlying material, such as a layer of dielectric material, through an etching process.
[0026] The key feature of the present invention is the use of a radiation source to cause radiation damage to a crystalline structure. To achieve this, a well defined minimum energy transfer is needed. This is called the displacement energy, E D . Energy transfers exceeding E D will cause atom displacement, either primary displacement, when a host ion is struck by one of the instant particles, or secondary displacement, when energy transfer is from the host atom previously struck. Energy values of E D in eV for a range of group III-V materials are given in the table below.
GaAs 9/9.4 InP 6.7/8.7 InAs 6.7/8.3 InSb 5.7/6.6
[0027] Whilst it is known that vacuum ultraviolet (VUV) radiation can cause damage to semiconductor structures, this has always previously been investigated on the basis that this damage should be avoided, or at least repaired by annealing to ensure that these defects do not affect the operation of the device.
[0028] This novel, low cost, and simple technique can be applied for the fabrication of PICs in general, and WDM sources in particular. By applying a QWI technique in accordance with the present invention, the bandgap energy of a QW material can be tuned to different degrees across a wafer. This enables not only the integration of monolithic multiple-wavelength lasers but further extends to integrate with modulators and couplers on a single chip. This technique can also be applied to ease the fabrication and design process of superluminescent diodes (SLDs) by expanding the gain spectrum to a maximum after epitaxial growth.
[0029] The photonic integration research community currently views QWI technology as a promising approach only for two-section photonic devices as conventional QWI processes would otherwise become tedious and complicated. Although it is complex and not cost effective, researchers have instead preferred to use selective area epitaxy for multiple-section integration. The present invention demonstrates that the application of QWI is not limited to two sectional devices. In addition, the technique is more cost effective, and offers a higher throughput and higher yield compared to selective area epitaxy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Examples of the present invention will now be described in detail with reference to the accompanying drawings, in which:
[0031] [0031]FIG. 1 is a schematic diagram of an example of an ECR system;
[0032] [0032]FIG. 2 is a schematic representation of an InGaAs/InGaAsP SQW layer structure and a band diagram for the structure;
[0033] [0033]FIGS. 3A and 3B are graphs illustrating the PL spectra of samples exposed to Ar plasma;
[0034] [0034]FIG. 4 is a graph illustrating the relationship between Ar exposure time and relative bandgap energy shift for different microwave powers;
[0035] [0035]FIG. 5 is a graph illustrating the relationship between process temperature and relative bandgap energy shift;
[0036] [0036]FIG. 6 is a graph illustrating the relationship between process pressure and relative bandgap energy shift;
[0037] [0037]FIG. 7 is a schematic diagram of a sample partially masked by a layer of photoresist;
[0038] [0038]FIG. 8 is a graph illustrating the PL spectra obtained from the sample of FIG. 7 after exposure to an Ar plasma;
[0039] [0039]FIG. 9 is a graph illustrating the relationship between RF power and relative bandgap energy shift;
[0040] [0040]FIG. 10 is a graph illustrating the relationship between microwave power and relative bandgap energy shift;
[0041] [0041]FIG. 11 is a graph illustrating the relative bandgap energy shift for samples exposed to Ar plasma with different SiO 2 mask thicknesses;
[0042] [0042]FIG. 12 is a schematic diagram of a broad area gain guided laser; and,
[0043] [0043]FIG. 13 is a graph illustrating the normalized spectra of the device of FIG. 12.
DETAILED DESCRIPTION
[0044] The present invention is based on the discovery that a more effective form of plasma induced QWI can be achieved using high energy radiation, such as the VUV radiation generated in an ECR generated plasma. This plasma process operates in a totally different regime compared to that described in earlier plasma induced disordering QWI techniques. In an ECR, the microwave power control allows for the generation of high energy radiation that is not found in a conventional RIE machine. As a result, the QWI blue shift obtained using high energy radiation is significantly greater.
[0045] In an ECR system, a magnetic field is applied with an exciting electromagnetic wave. Electrons under these fields undergo a circular or orbital motion with a radius relating to the strength of the fields, and rotating at a frequency known as electron cyclotron frequency. If the frequency of the electromagnetic wave is equal to the cyclotron frequency, there will be a phase coherence causing the electrons to continuously gain energy. Under this condition, emission transfer of energy from the exciting electromagnetic field to the electrons takes place in what is known as the resonant process. In this resonant process, the electrons in the bulk of the plasma gain their energy from the exciting microwave and subsequently transfer the energy to the molecules via collisions, causing electron impact ionizations and generating a high plasma density. The highly ionized ions emit photons with VUV line emissions.
[0046] ECR plasma is becoming increasingly popular in microelectronics processing such as etching and thin film deposition due to its ability to sustain highly dissociated and highly ionized plasmas at relatively low pressures and temperatures. It has the capability to operate at lower pressure (typically 10 −3 to 10 −2 torr) than a conventional RIE RF plasma and its degree of ionization can be as high as 10% or so in some cases.
[0047] Resonance, or enhanced energy absorption, occurs when the frequency of the alternating electric field equals the cyclotron frequency. At this condition, the electron's spiral motion is in phase with the alternating electric field, allowing it to be accelerated resonantly with each change in polarity. At the industrial microwave frequency of 2.45 GHz, resonance occurs with a permanent magnet of 873G. For resonant absorption of energy to occur efficiently, the electrons must undergo their cyclotron orbits without collision with neutrals. Collisions interfere with energy absorption due to energy transfer to the neutrals and randomization of direction. As a general rule, collisions result in inefficient electron cyclotron heating at pressures above 20 mTorr. In an efficient ECR discharge, ion and electron densities up to 10 12 cm −3 are achievable. This is roughly 100 to 1000 times the density achievable in plasma generated by conventional RIE systems.
[0048] The ECR system used in the processing of the samples described below was a Plasma Quest Series II PQM-9187-A system. This is shown in FIG. 1. The system 10 consists of a microwave generator 11 of 2.45 GHz that is fed into the ECR cavity 12 through a quartz window. The microwave power ranges from 0-1500 W. It is attached with a three-stub tuner, which consists of three impedance matching stubs installed within a 9-inch length of waveguide 13 . This is used to reduce the reflected power of microwave energy directed to an easy-to-tune plasma source or customer load. Additional Nd-Fe-B permanent magnets 14 of alternating polarity are arranged around the perimeter of the reactor and embedded in the grounded upper electrode. This arrangement produces a magnetic field which better confines the plasma. It focuses the plasma ions into the center of the chamber, away from the chamber wall, and thereby reduces the loss of charged species to the wall.
[0049] The ECR reactor also consists of a sample chuck 15 that is connected to a 13.56 MHz RF power supply 16 . The maximum power producible by the RF generator is 500 W. The microwave power controls the amount of dissociation and generation of reactive species. On the other hand, the RF source provides the bias to the substrate and thus controls the ion flux to the substrate, enhancing the directionality of the process.
[0050] The In 2 Ga 1−Z As/In x Ga 1−x As y P 1−y structures used in the examples described below were grown by metal organic chemical vapour deposition (MOCVD) on an InP substrate. The single quantum well (SQW) region is undoped and consists of a 5.5 nm wide In 2 Ga 1−z As QW, with 12 nm In x Ga 1−x As y P 1−y (λ g =1.26 μm) barriers. The active region was bounded by step graded index (GRIN) In x Ga 1−x As y P 1−y confining layers. The thickness and composition of these layers were 50 nm of λ g =1.18 μm and 80 nm of λ g =1.05 μm, respectively. The structure, which was lattice matched to InP throughout, was completed with a 1.4 μm InP upper cladding layer and a layer of 0.65 μm In x Ga 1−x As y P 1−y followed by a 0.1 μm In 2 Ga 1−2 As which functions as the contact layer. The lower cladding layer was sulfur-doped to a concentration of 2.5×10 18 cm −3 . The first upper cladding layer (InP) was doped with Zn to a concentration of 7.4×10 17 cm −3 and the subsequent layer was doped with 2×10 18 cm −3 and 1.3×10 19 cm −3 concentration of Zn respectively. A summary of the layer structure and graphical interpretation is given in Table 1 and FIG. 2, respectively.
TABLE 1 Thick- ness Conc Layer (nm) Material Ts (x) Dopant Type (cm −3 ) 11 100 In(x)GaAs 650 0.53 Zn p 8.000e + 18 10 50 InGaAsP, 650 Zn p 2.000e + 18 λg = 1.18 9 1400 InP 650 Zn p 6.000e + 17 8 80 InGaAsP, 650 u λg = 1.05 7 50 InGaAsP, 650 u λg = 1.18 6 12 aInGaAsP, 650 u λg = 1.26 5 5.5 In(x)GaAs 650 0.53 u 4 12 InGaAsP, 650 u λg = 1.26 3 50 InGaAsP, 650 S n 5.000e + 17 λg = 1.18 2 80 InGaAsP, 650 S n 5.000e + 17 λg = 1.05 1 1000 InP 650 S n 2.000e + 18 — — *InP — Substrate
[0051] The GRIN structure is used to produce better optical confinement due to the difference in refractive index, i.e. higher refractive index in the QW as compared to the barriers. The lower GRIN region is doped with S (n-type), but the upper GRIN region (layer 7 - 8 ) is not doped with p-type Zn to prevent it from diffusing into the QW region during the QWI stage, hence degrading the quality of the active layer. The top InGaAs layer is used as a contact layer, and an InGaAsP layer is sandwiched between the InP and InGaAs layer so as not to cause an abrupt change from InP structure to InGaAs structure.
[0052] Samples 17 were first cleaned and cleaved into size of 2×2 mm 2 . They were then exposed to Ar plasma within the ECR arrangement 10 shown in FIG. 1 at different process conditions. For the first set of samples subjected to plasma treatment, the RF and microwave powers were fixed at 450 W (self-DC bias around −35 V) and 1400 W respectively, with an Ar flow rate of 50 scam and process pressure of 30 mTorr. The exposure time was varied from 1 to 15 minutes. Another set of samples was then exposed to the Ar plasma with the same process conditions with the exception that the microwave power was reduced to 800 W (self-DC bias around −60 V). The exposure time was varied from 1 to 9 minutes. After plasma exposure, the samples were subsequently annealed at 600° C. for 2 minutes using a rapid thermal processor (RTP). A GaAs proximity cap was used during the annealing stage in order to provide As over pressure to the samples.
[0053] [0053]FIGS. 3A and 3B show the PL spectra of the samples exposed to Ar plasma at different times and microwave powers of 1400 W and 800 W, respectively. FIG. 4 shows the relative bandgap shift with respect to the as-grown sample, as a function of exposure time, for Ar plasma generated using RF 450 W and microwave powers of 800 W and 1400 W, respectively.
[0054] As can be seen from FIG. 4, the QWI effect, which causes the broadening of the bandgap energy and blue shifting of the luminescence wavelength, can be observed for the samples exposed to the Ar plasma. The degree of intermixing increases gradually with increasing exposure time for samples exposed at 1400 W. The bandgap shift saturated at about 106 nm (72 meV) after 10 minutes of plasma treatment. The saturation in energy shift implies that the maximum point defects generated by both ion bombardments and radiation damage saturates after an exposure time of 10 minutes. The samples exposed to 800 W produced results of similar trend to that of 1400 W, but with lower degrees of blue shift. This could be attributed to the use of lower microwave power, and hence lower ionization of the Ar plasma. The highest attainable blue shift under this exposure condition was found to be around 66 nm (42 meV) for the sample treated for 9 minutes.
[0055] As can be seen from FIG. 5, there is no linear relationship governing the bandgap energy shift and the process temperature. A maximum bandgap shift of 32 nm was obtained at a process temperature of 100° C. It is generally expected that higher temperature would produce higher degree of QWI under the ion bombardment damage process. However, this phenomenon was not observed here. It could thus be concluded that the concentration of the damage induced by this process is below a certain threshold to activate QWI.
[0056] [0056]FIG. 6 shows the bandgap energy shift with respect to different process pressures. The bandgap energy shift increased to a maximum of 49 nm at process pressure of 30 mTorr and gradually decreases with increasing process pressure. From the results obtained, it could be explained that as the process pressure increased from 10 mTorr to 30 mTorr, the density of the neutral and ionized species of the plasma increased. Thus, a higher amount of damage is produced, resulting in a higher degree of intermixing. However, as the pressure continues to increase, the mean free path of the ions becomes shorter. This causes the amount of ions and neutral species colliding onto the sample surface to reduce significantly, thus reducing the amount of damage induced. Higher ionization due to increasing process pressure should produce greater radiation damage. However, the results indicate that the radiation intensity change is minimal and its effect on QWI over a range of different pressures remains fairly constant.
[0057] QWI is generally only useful if it can be localized to desired areas of the semiconductor, i.e. it is able to intermix selectively. Selectivity is an important aspect in a process as it provides the possibility of integration. For QWI, interface sharpness between the intermixed and un-intermixed region is known as the spatial resolution. High spatial resolution is necessary in intermixing processes as it ensures the compactness in device integration.
[0058] In order to study the selectivity of the plasma process, samples 20 of 2×4 mm 2 were prepared (FIG. 7). Half of the samples were then patterned with photoresist 21 . These samples 20 were exposed to an Ar plasma of RF 450 W and microwave 1400 W for 5 minutes. The portion masked with photoresist 21 is shielded from the damage caused by the Ar plasma exposure and thus would undergo none or minimal QWI after the RTP process.
[0059] [0059]FIG. 8 shows the PL spectra obtained from the sample 20 after Ar exposure and subsequent thermal annealing. As can be seen from the graph, the portion masked with a layer of photoresist 21 underwent a small amount of bandgap shift (˜10 nm), whereas the portion 22 exposed to the plasma exhibited a much larger bandgap shift of 64 nm, thus producing a relative bandgap difference of 54 nm between masked and unmasked regions. This result strongly indicates that high selectivity is obtainable in the InGaAs-InGaAsP samples using only photoresist as a masking layer. The small amount of bandgap shift in the masked region could be due to the bandgap modification induced by thermal related effects.
[0060] The plasma generated using only RF power is expected to predominantly create ion bombardment damage. This is mainly due to the high potential difference between the plasma and the semiconductor, which could be as high as 130 eV. By exposing the sample with such plasma, the QWI mechanism in an ion-bombardment dominated plasma environment can be investigated.
[0061] A set of samples was exposed to Ar plasma generated using different RF conditions, while other process parameters were held constant. All the exposures were performed for 5 minutes. FIG. 9 shows the relative bandgap shift as a function of RF power. As can be seen from FIG. 9, samples treated with plasma under RF-only conditions exhibit insignificant bandgap shift, with a maximum shift of 22 nm (10 meV). The bandgap shifts under different RF values were also rather small.
[0062] A further set of samples was then exposed to plasma generated by different microwave conditions, while other process parameters were held constant. All the exposures were performed for 5 minutes. Upon exposure, the samples were annealed at 600° C. for 2 minutes. FIG. 10 shows the relative bandgap energy shift as a function of microwave power.
[0063] As can be seen from FIG. 10, samples treated with plasma under microwave-only conditions produced a bandgap energy shift as large as 66 nm (42 meV). The amount of bandgap shift also increases with increasing microwave power. This result implies that high-energy VUV radiation generated by high-density ECR plasma has a stronger influence on the QWI effect than ion bombardment. It thus plays an important role in QWI in the InGaAs-InGaAsP structures using this process.
[0064] Table 2 below provides a summary of the process variables investigated above, showing the potential operating range of each variable and the preferred operating range.
TABLE 2 Potential Preferred Operating Operating Range Range RF power 0˜500 W 0 W Microwave power 300˜3000 W 1000˜2000 W Process temperature 25˜500° C. 25˜200° C. Process pressure 0.1˜100 mTorr 20˜50 mTorr Exposure time 30 s˜1 hr 4˜14 min
[0065] In the following example, a layer of SiO 2 is used to act as an Ar plasma exposure mask to investigate the rate of intermixing with respect to the SiO 2 thickness deposited on InGaAs/InGaAsP MQW. The ability to control the amount of intermixing with different SiO 2 thicknesses would enable the lateral variation of bandgap energy in the sample. This would enable the realization of devices requiring different operating wavelengths across the sample, such as multiple wavelength lasers.
[0066] InGaAs/InGaAsP MQW samples were cleaved into 2×2 mm 2 , and SiO 2 of different thicknesses were deposited on the samples using a PECVD system. The SiO 2 thicknesses ranged from 100 nm to 1200 nm. Four samples were used for each SiO 2 thickness; this was done in order to study the repeatability of the process.
[0067] All the samples were exposed to an Ar plasma of RF 450 W and microwave 1400 W for 10 minutes. After exposure, two of the samples for each SiO 2 thickness were placed in a solution of HF:H 2 O in the ratio of 2:1. This is to remove the SiO 2 layer on the samples before going through the annealing process. Thus, the effect of annealing with and without SiO 2 capping could be studied. The samples were then annealed in an RTP at a temperature of 590° C. for 2 minutes. PL measurements were then performed to analyze the degree of QWI.
[0068] [0068]FIG. 11 shows the relative bandgap energy shift for samples exposed to the Ar plasma with different SiO 2 thicknesses. As can be seen from FIG. 11, the degree of intermixing decreased gradually as the thickness of SiO 2 increases. However, the degree of intermixing remains rather constant, having a bandgap shift in the range of 40-50 meV, when the SiO 2 thickness is below 500 nm. No significant bandgap shift was observed for an SiO 2 cap thickness above 800 nm. In the SiO 2 thickness range of 500-800 nm, the degree of intermixing reduced significantly with increasing thickness.
[0069] Accordingly, we have shown that QWI in InGaAs/InGaAsP MQW using Ar plasma exposure is controllable by altering the thickness of SiO 2 deposited on the sample before exposure. The ability to control the degree of intermixing enables the fabrication of devices which require different bandgap energy across a sample. Devices such as multiple wavelength lasers for WDM applications could be realized by controlling the thickness of the SiO 2 across the wafer before Ar exposure. With the invention of the novel gray scale mask lithographic technique described in our co-pending International patent application number (Agent's reference PJF01075WO), this fabrication would be further simplified, as it requires only one-step RIE processing to transfer various thickness of SiO 2 onto the samples. Alternatively, the mask may consist only of a photoresist pattern having different thicknesses applied using the same gray scale mask technique.
[0070] In order to investigate the lasing wavelength of the materials after QWI, broad area gain guided lasers were fabricated from an as-grown sample (no plasma treatment and annealing), a control sample (no plasma treatment but annealed), and an Ar plasma intermixed sample.
[0071] Samples of 6×6 mm 2 were cleaved along the crystal orientation from an InGaAs/InGaAsP MQW wafer. They were then exposed to Ar plasma of RF 450 W and microwave 800 W for 5 minutes. An annealing step at 590° C. for 120 seconds was subsequently carried out to promote QWI. The samples were then coated with a 200 nm PECVD SiO 2 dielectric cap. Next, 50 μm stripe windows were defined using photolithography and both dry and wet etching were used to open the windows. To minimize RIE damage from the CF 4 and O 2 process, dry etching was first carried out for 5 minutes, followed by wet-etching using buffered HF for 10 seconds, to remove the remaining 75 nm of SiO 2 . These lasers are gain-guided since the injected current produced population inversion and a subtle waveguide effect only in the 50 μm stripe regions. After this, front contact metallization (p-type: Ti/Au, 50 nm/200 nm) was done using an electron beam evaporator. Samples were then thinned to a thickness of around 180 μm. Another metallization for back contact (n-type: Au/Ge/Au/Ni/Au, 14 nm/14 nm/14 nm/11 nm/200 nm) were evaporated and the whole fabrication was completed by annealing the samples using RTP at 360° C. for 60 seconds. The processed samples were then scribed into individual lasers with different cavity lengths for characterization. A schematic diagram of a bandgap shifted oxide stripe laser 30 is given in FIG. 12.
[0072] [0072]FIG. 13 shows the as-grown, control and Ar plasma intermixed laser spectra. From the Figure, the control samples and as-grown samples exhibit almost similar peak lasing wavelength at 1.55 μm, and the Ar plasma intermixed lasers give a peak lasing wavelength at 1.517 μm, a shift of 38 nm.
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In a method of manufacturing a photonic integrated circuit having a compound semiconductor structure having a quantum well region, the structure is irradiated using a source of photons to generate defects, the photons having energy (E) at least that of the displacement energy (E D ) of at least one element of the compound semiconductor. The structure is subsequently annealed to promote quantum well intermixing. The preferred radiation source is a plasma generated using an electron cyclotron resonance (ECR) system. The structure can be masked in a differential manner to selectively intermix the structure in a spatially controlled manner by controlling the exposure portions of the structure to the source of radiation.
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CROSS REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of application Ser. No. 152,751, filed May 23, 1980, now abandoned.
TECHNICAL FIELD
The heparinizing of blood, especially for use in the in vitro testing of blood samples.
BACKGROUND ART
Heparin is normally provided by the pharmaceutical industry as an alkali metal (for example, primarily sodium) or alkaline earth (for example calcium) salt in view of the limited stability of the free acid form of heparin. The salts are most commonly provided for pharmaceutical use in the form of solutions. Solid heparin salts tend to be somewhat hygroscopic and gradually absorb water unless maintained in a low humidity environment. They are amorphous rather than crystalline and are available as fine powders.
Both the solution and solid forms of the heparin salts are conventionally utilized in blood-gas analyses wherein they serve as anticoagulants to maintain liquidity of the blood being tested. Blood-gas analyses are widely used in diagnostic medicine, oxygen and carbon dioxide contents of blood samples being of particular importance. From such measurements, a physician may obtain accurate oxygen level readings from which he may more accurately anticipate the patient's supplementary oxygen needs.
The measurement of arterial blood gas normally involves drawing a sample of blood into a syringe containing an anticoagulant and then injecting the blood sample into an analyzing instrument. The anticoagulant is used to maintain the liquidity of the blood sample so that the partial pressures of the blood gases are at substantially the same level as when initially drawn.
Even though the procedure seems simple and straightforward there are numerous opportunities for sources of error to be introduced. One particular source of error has been found to result from the method in which the anticoagulant is added to the drawn blood samples.
There are three primary methods for the introduction of an anticoagulant such as heparin into the blood samples. The first method involves the drawing of a quantity of heparin solution into a syringe in order to wet the interior walls. A substantial portion of the excess heparin is ejected and the blood is then drawn into the syringe from the patient. The blood when drawn mixes with the heparin solution to prevent coagulation. The error in this method results from the fact that an indeterminate amount of heparin solution remains in the syringe interior, needle hub and cannula. As a result, the drawn blood sample is diluted by an indeterminate amount of heparin solution which in most cases leads to less accurate blood gas data.
A second method involves the use of preheparinized syringes. These syringes are prepared by depositing a lyophilized heparin on the internal surface of the syringe. They have been found to vary in the location and the amount of heparin on the syringe barrel wall. Also, the deposited heparin dissolution rate into the blood is slower than optimal and is unpredictable. This slow dissolution rate combined with the variability in amount allows partial blood coagulation thereby introducing a source of error into the analysis. Because lyophilized heparin is more difficult and complex to manufacture and use than a heparin solution, these preheparinized syringes have been found to be much more costly without proportionately minimizing the amount of potential error.
A third method recently introduced comprises placing an anticoagulant tablet in the hub of the needle of the syringe used to obtain a blood sample from a patient. The blood flowing through the needle and into the syringe dissolves the tablet and the blood is heparinized. These tablets are comprised of a salt of heparin, a tablet binder and a pH controlling substance. Although the rate of dissolution of these tablets is fast compared to the heparinized syringe, the time required for disintegration is up to 20 seconds, and for complete dissolution up to two minutes. Also, the use of these tablets requires a mixing step after the blood is drawn into the syringe. The tablet binder and pH controlling substance are adjuvants requiring added cost and additional manufacturing complexities.
DISCLOSURE OF THE INVENTION
The present invention relates to microfibers of amorphous heparin salts which have average length to diameter ratios of at least 20 (and preferably at least 80), to open, nonwoven webs of the fibers, to processes for their preparation and to a method for heparinizing blood which comprises intermixing heparin salt microfibers (ordinarily a web of such fibers) with blood. The microfibers are of particular use in in vitro blood test procedures. They provide a much more rapidly dissolving heparin source which does not dilute the blood which is heparinized. They are easily and inexpensively prepared and can be conveniently quantized in individual test needles and syringes.
The process of the invention comprises expressing an aqueous heparin salt solution into a large excess of a fluid which is a nonsolvent for the heparin salt. It has in fact been discovered in connection with the present invention that when a much greater proportion of the fluid nonsolvent (a gas stream such as air or nitrogen or a liquid nonsolvent such as isopropanol) is utilized, the water can be removed very rapidly from the heparin salt solution while the latter is in rapid laminar motion and the heparin salt fibers are formed, rather than a blocky precipitate. Thus, in the case of a liquid nonsolvent, the ratio (by volume) of the nonsolvent to the aqueous heparin salt solution is 10 or greater (e.g. from 10 to 50) and is preferably 20 or more.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention may be obtained with reference to the drawings wherein
FIG. 1 is a schematic diagram of an apparatus for preparing a microfibrous web of the present invention;
FIG. 2 is an enlarged section through a microfibrous web of the present invention; and
FIG. 3 is a schematic diagram illustrative of an alternative apparatus for the preparation of a microfibrous web of the present invention.
In the apparatus of FIG. 1, the microfibers are formed in a stream of an inert gas. The microfiber-blowing portion of the apparatus can be a conventional structure as taught, for example, in Wente, Van A., "Superfine Thermoplastic Fibers", in Industrial Engineering Chemistry, Vol. 48, pages 1342 et seq (1956), or in Report No. 4364 of the Naval Research Laboratories, published May 25, 1954, entitled "Manufacture of Superfine Organic Fibers" by Wente, V. A.; Boone, D. C.; and Fluharty, E. L. Such a structure includes a die 10 which has a solution injection chamber 11 through which liquified fiber-forming solution is advanced; die orifices 12 arranged in line across the forward end of the die and through which the fiber-forming solution is directed; and cooperating gas orifices 13 through which a gas, typically air or nitrogen, is forced at very high velocity. The high-velocity gaseous stream draws out and attenuates the extruded fiber-forming heparin solution, whereupon the fiber-forming heparin solidifies as microfibers during travel to a collector 14. The collector 14 is typically a finely perforated screen, which in this case is in the form of a closed-loop belt, but which can take alternative forms, such as a flat screen or a drum or cylinder. Gas-withdrawal apparatus may be positioned behind the screen to assist in deposition of the microfibrous web 22 and removal of gas. It will be understood by the art that operating conditions must be controlled to avoid decomposition of the heparin.
The web, as shown in FIG. 2, can be cut or shaped into a variety of forms, e.g. plugs, discs, cubes, etc. The crossover points of the individual fibers in the webs may be partly or completely fused.
The apparatus shown in FIG. 3 forms the webs by precipitating the microfibers from solution. The apparatus includes a heparin solution injecting portion, a nonsolvent fluid circulating system and a web take-off portion. The fluid system is comprised of a collection reservoir 30 and a filament attenuation section 36. In line between the reservoir 30 and attenuation section 36 is a pump 32 and a flow meter 34 which may be used to control the flow rate of the fluid. The selection of the fluid is dependent on the environment in which the heparin is to be used. The heparin solution is injected into the fluid path at filament attenuation section 36 through injection orifice 44. The heparin solution enters injection orifice 44 from the heparin reservoir 38 after passing through control valve 40 and flow meter 42. The movement of the heparin solution may be facilitated by numerous means known to the art, e.g. a pump, air pressure, etc. As with the air-blown system, it is necessary that the fluid stream have a relative velocity greater than that of the injected stream of the heparin. The combined streams (e.g. fluid and heparin) are directed to the web take-off portion which is comprised of a movable collector 48 where the microfibers are collected in web form and the fluid returns to the fluid reservoir 30 for recycling. Screen 48 movement is facilitated by rollers 51 and 53 and motor 52. The width of the formed web 54 is controlled by the gauge bars 46. The web 54 passes under a wringer roller 50 which further aids in the removal of the fluid from web 54. Web 54 may then be directed to a drier or to further processing as desired.
DETAILED DESCRIPTION
The heparin salt webs of the invention are, as noted previously, particularly useful in and adapted for certain in vitro blood tests, e.g. in which the blood is subjected to them immediately upon being drawn from a mammalian subject in order to stabilize the blood in a liquid state suitable for testing. This stabilization reaction is commonly referred to as heparinization.
The webs are, when properly packaged and stored, stable for years under ambient conditions or longer when stored cold. At relative humidities of approximately 55 percent (at ambient temperatures, e.g. 20°-25° C.) they are still stable for several months although under very high humidity conditions they absorb an excess of moisture and deform grossly. They dissolve very rapidly in aqueous solutions, including blood, due, it appears, to the open structure and relatively high surface area of the microfibers and to the absence of any solid excipient or other additive. Thus, relatively small pledgets of heparin web (less than about one cubic centimeter) have been found to dissolve completely in about one second in water or blood.
The webs are moderately stable to cobalt irradiation and can thus be easily sterilized. They are capable of absorbing up to about three megarads while retaining about 83 percent of the USP activity and 77 percent of the anti Factor X a activity of the heparin salt starting material. The density of the individual microfibers is about 1.8 g/cc. The acidity of solutions of the heparin salt microfibers depends upon the acidity of the solutions from which they were originally prepared and the acidity of the water used to dissolve them. However, the webs do not significantly affect the pH of the blood samples which are heparinized due to the relatively small amount used and the buffering capacity of blood.
The length and diameter of the microfibers is dependent upon the process used to prepare them, for example stirring rate, means of extrusion, velocity of extrusion, the nonsolvent (if any) used and the ratio of nonsolvent to water used. Generally, the shorter fibers are less useful for many purposes because they are difficult to handle and form poorer webs and mats. Thus, the average length to diameter ratio of the fibers is preferably at least 20 and is more preferably at least about 80.
The cation in the heparin salts is generally selected from group I or group II of the Periodic Table of the Elements and is normally an alkali metal, an alkaline earth or zinc, for example lithium, sodium, potassium, magnesium, calcium or zinc. Fibers of salts of heparin and all of these cations having length to diameter ratios of at least 80 are conveniently prepared by the process of the invention.
The strength and structural integrity of the webs, their ability to be cut, punched or divided into pieces of desired shapes and weights, their open structure and high surface area render them ideally suited for rapidly heparinizing blood under controlled conditions, e.g. in the blood gas analysis test. Such pieces of the web may be placed in a syringe in any acceptable way, but are preferably inserted into the hub of a needle through which blood to be analyzed is drawn. When utilized in this way the heparin web pieces heparinize the blood drawn through the needle virtually instantaneously and essentially eliminate all presently known sources of error due to inadequate heparinization during blood gas analysis. This method is faster than any previous heparinization method, and allows immediate analysis of the blood sample drawn.
The weight of the fragment to be used in a single syringe depends upon the specific USP activity of the heparin and will be gauged to provide a desired level of USP activity, for example at least 250 USP units of anticoagulant activity. The density of the web and the size of the cut piece may be varied as desired. Typical sizes are 1.5 to 4.0 mm. in diameter and 1 to 5 mm. in thickness. Thinner discs of larger diameter of heparin web of at least 250 units activity may be placed in the barrel of the syringe before inserting the plunger as an alternative to placing the web in the needle hub.
The process of preparing the microfiber, which constitutes a separate aspect of the invention, comprises expressing an aqueous heparin salt solution into a large excess of a fluid which is a nonsolvent for the heparin salt. The fluid can be gas which is inert with respect to the heparin salt, such as nitrogen or air or a liquid nonsolvent for heparin salt and the process can be carried out as a batch operation or continuously. Three more specific embodiments of the process are as follows:
1. An aqueous solution of from about 40 percent to 60 percent heparin salt by weight is expressed through a small concentric orifice into a stream of dry inert gas and blown onto a collection screen. See FIG. 1.
2. An aqueous solution of from about 10 percent (w/w) to 40 percent heparin salt by weight is expressed into a rapidly stirred dry liquid nonsolvent for heparin such as methanol, ethanol, 1-propanol, isopropanol, t-butanol, acetone and the like.
3. An aqueous solution of from 10 percent to 30 percent by weight heparin salt is continuously mixed into a stream of nonsolvent liquid and the microfibers are collected on a moving screen while the nonsolvent is recirculated and excess water is removed from the solvent stream. The concentration of nonsolvent is maintained at 95 percent or higher. See FIG. 3.
When a batch process is used with a liquid nonsolvent (2 above), the concentration of the nonsolvent must be retained at greater than 90 percent by volume at all times during the process (the remainder of less than 10 percent being the aqueous solution of the heparin salt) and preferably the concentration of the liquid nonsolvent is retained at 95 percent or even better, 99 percent or more by volume. Thus, even at 90 percent of nonsolvent liquid, the resulting microfibers are short and thin. The concentration of the liquid nonsolvent is maintained at 95 percent by volume or greater in the continuous process. In both cases, the microfibers increase in length (and hence in length to diameter ratio) as the concentration of the water decreases. The preferred liquid nonsolvent is isopropanol since it produces the best microfibers.
The microfibers obtained from the foregoing processes contain some water and, where a liquid nonsolvent has been used, normally some of it as well. The combined nonsolvent and water content of the microfibers (webs) generally ranges up to 25 percent, usually 10 to 15 percent. The webs are dried by conventional methods such as vacuum oven, streams of dry gas, expressing or centrifuging off excess fluid followed by oven or gas drying, and the like to maintain flexibility and pliability. The resulting webs may then be cut, sliced, punched or divided in other conventional ways due to the inherent strength and structural integrity of the webs. More specifically, a web of the microfibers may be dried in a vacuum oven for example at about 60° C. and will ordinarily reach desirable handling characteristics after 2 to 3 hours. Such a drying cycle typically produces product having a USP LOD (loss on drying) of about 7 to 11 percent. The drying time needed to produce such a product can be reduced by varying these conditions. When heparin salt microfibers are overdried, they become flaky and fragile but will absorb moisture under controlled humidity, e.g. about 25 to 35 percent, preferably 30 to 35 percent, from the atmosphere and again become pliable.
The following examples are given for the purpose of further illustrating the invention but are not intended, in any way, to be limiting of the scope thereof. All parts are given by weight unless otherwise specifically noted.
EXAMPLE 1
A sample of 10 g. of sodium heparin (U.S.P. activity 161 units per milligram) is dissolved in 15 g. of water to provide a solution of 40 percent by weight of sodium heparin. The solution is passed through a hypodermic needle with a tip opening of 0.84 mm. (18 gauge needle) by using a syringe as the pump. The solution expressed from the needle is blown by a stream of compressed air at a pressure of about 3400 N/m 2 blown through a 6.35 mm. diameter nozzle. The resulting microfibers are further attenuated and dried by blowing a stream of warm air from a heat gun over the stream issuing from the nozzle. The sodium heparin microfibers formed are collected at a web screen consisting of a 232 cm 2 piece of standard laboratory burner gauge. 300 Mg. of the microfibers are obtained from 3 ml. of the solution (a yield of 25 percent), and the balance of the sodium heparin is collected as droplets in a pan.
A portion of the resulting web is found to dissolve instantly in water.
EXAMPLE 2
The web of material from Example 1 is evaluated as follows:
A 12 mm. diameter disc of the web weighing about 2 mg. is dropped into a small (about 0.5 ml.) quantity of rabbit blood on a watch glass and observed to dissolve immediately.
Three 13 mm. diameter discs of the web are cut and weighed by difference after being inserted into the barrel of 5 ml. plastic syringes. Human blood (1 ml.) is drawn into each of the syringes from a reference supply of blood. The web dissolves in less than one second. No clotting is observed. The pH of both the reference supply of blood and each of the heparinized samples is checked as shown in Table I below by using the pH sensor in a commercial blood gas analyzer.
TABLE I______________________________________ Weight of pH ofSample Description Heparin Disc Sample______________________________________A Reference Blood none 7.32B Sample 1 0.0021 g. 7.33C Sample 2 0.0019 g. 7.33D Sample 3 0.0017 g. 7.32______________________________________
Thus, the sodium heparin web does not significantly affect the pH of the blood sample.
EXAMPLE 3
0.8 Ml. of a 25 percent by weight aqueous solution of sodium heparin is expressed into a stirred reactor containing 50 ml. of isopropanol from a syringe through a 22 gauge needle. The resulting microfibers collect and mat around the stirring bar. The mat or web is pressed between two pieces of filter paper, placed on a vacuum filter apparatus covered with a rubber dam and dried by pulling a vacuum on the apparatus.
A portion of this web is removed and tested for solubility in water. It dissolves very rapidly.
EXAMPLE 4
A syringe with a 22 gauge needle is used to extrude 6.2 g. of a 22.5 aqueous solution of sodium heparin into a magnetically stirred reactor containing 120 ml. of anhydrous isopropanol. The mixture is poured into a homogenizer and homogenized for about 2 minutes at high speed. The mixture is transferred to the Buchner funnel of a vacuum filter apparatus, allowed to settle and a vacuum is applied. A piece of filter paper is placed on top of the sodium heparin web or mat, and a rubber dam is used over the Buchner funnel. After the web has been pulled dry under vacuum, it is placed in a vacuum drying over at 85° C. for about 18 hours. The weight of the web is 1.587 g. (1.395 g. theoretical) indicating about 15 percent solvent content.
The web is cut with a 3.8 mm. cork borer to form discs of the heparin web weighing about 2.5 mg. which dissolve very rapidly in blood or water.
EXAMPLE 5
A sample of heparin web is prepared using the method of Example 4. The web is photomicrographed and the dimensions of fibers of the web are measured. The diameter of the fibers range from 3 to 50 microns. The relative lengths of the individual fibers are measured to be at least 20 to 30 times greater than the diameter. Generally the lengths of the fibers are 80 or more times greater than the diameter.
EXAMPLE 6
A 25% aqueous solution of calcium heparin is prepared. A sample (7.2 g.) of the solution is expelled from a syringe through an 18 gauge needle into 200 ml of isopropyl alcohol. Fibers having average length to diameter ratios greater than 80 are formed, collected and dried under vacuum at 50° C. for 16 hours. The web has excellent integrity and dissolves rapidly in water.
A sample of this web is stored at 37° C. under 75% relative humidity for 20 days. The structural integrity of the web is maintained and a sample is observed to dissolve rapidly in water.
A sample of calcium heparin web is sterilized with ethylene oxide. It maintains its physical integrity, ability to disintegrate in water and anticoagulant activity. Blood gas analyses carried out on blood treated with this calcium heparin web compare favorably with those utilizing the sodium heparin webs.
EXAMPLE 7
A. Preparation of Zinc Heparin
A sample of 5 g. of calcium heparin web is dissolved in 20 ml of deionized water. To this solution is added 20 ml of an aqueous solution of 4.4 g. of zinc sulfate heptahydrate. After stirring one-half hour the solution is filtered to remove calcium sulfate. To the filtrate is added 150 ml of methanol, providing a gummy product. The solvents are removed by decantation, the gum is dissolved in 20 ml of water, filtered and reprecipitated with 180 ml of methanol. The precipitate is separated by decantation of solvents, dissolved in 20 ml of water and added to 300 ml of stirred isopropyl alcohol. Solid zinc heparin precipitates and is separated by filtration providing 4.47 g. after air drying.
B. Preparation of Zinc Heparin Web
A solution of 1 g. of zinc heparin in 4 ml of deionized water is prepared. Using a syringe fitted with an 18 gauge needle the solution is injected through a 0.8μ filter into 100 ml of rapidly stirred isopropyl alcohol. The resulting fibers, which have an average length to diameter ratio greater than 20, form a web which is separated by filtration and dried at 105° C. for one hour under vacuum. The total weight of the web is 0.81 g. of zinc heparin.
A small plug of the web is observed to dissolve very rapidly, almost instantaneously, in water.
EXAMPLE 3
A. Preparation of Magnesium Heparin
An aqueous solution of magnesium chloride (300 ml of 5% w/v) is added to a 10 g. sample of purified sodium heparin. The pH of the solution is adjusted to between 6.5 and 7.0 (6.6 measured) by the addition of 0.1 N hydrochloric acid or magnesium hydroxide. Methanol (300 ml) is added and the mixture is stirred for one-half hour. Isopropyl alcohol (150 ml) is added and the mixture is stirred for one-half hour. The magnesium heparin containing-layer is separated by decantation and dissolved in 5% (w/v) aqueous magnesium chloride solution. The solution is diluted with an equal volume of isopropyl alcohol and the magnesium heparin containing-layer is separated by decantation. This layer is dissolved in 1% (w/v) aqueous magnesium chloride solution and the pH is adjusted to 6.5 to 7.0 (6.7 measured) with 0.1 N hydrochloric acid. The solution is diluted with an equal volume of isopropyl alcohol and stirred. The magnesium heparin gradually separates out as a syrup.
The syrup is collected with a syringe and expelled into a swirling bath of isopropyl alcohol. A precipitate of magnesium heparin is formed which is collected on filter paper and dried under ambient conditions to provide 9.5 g. of product.
B. Preparation of Magnesium Heparin Web
Using the magnesium heparin from Step A., a 20% (w/w) solution of magnesium heparin in water is prepared. A sample (10 ml) of this solution is collected in a syringe and expelled through an 18 gauge needle into a swirling bath of isopropyl alcohol. Fibers of magnesium heparin are formed which have an average length to diameter ratio greater than 20. These fibers are collected on filter paper and dried at 60° C. for 30 minutes under vacuum. Several webs are prepared from these fibers.
EXAMPLE 9
A 20% aqueous solution of potassium heparin is prepared. 9 g. of this solution is expelled through an 18 gauge needle into 200 ml of isopropyl alcohol. Fibers having an average length to diameter ratio greater than 20 are formed, collected and dried at 50° C. under vacuum. A plug of the web disintegrates completely in water in less than 5 seconds.
EXAMPLE 10
Lithium heparin is prepared from sodium heparin by substantially the process of Example 8, but utilizying lithium chloride in place of magnesium chloride.
A 25% aqueous solution of the lithium heparin is prepared and a portion (7.2 g.) of this solution is expelled through an 18 gauge needle into 200 ml of isopropyl alcohol. Fibers having an average length to diameter ratio greater than 20 are formed, collected and dried under vacuum at 50° C. for 16 hours. A plug of the web disintegrates completely in water in less than five seconds. The fibers are firm and of excellent quality for the formation of a web.
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Microfibrous heparin salts, nonwoven webs of such fibers, a process for preparing the fibers and the use of the webs for the rapid heparinization of blood are disclosed.
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[0001] The present invention relates generally to a relocatable oil sand slurry preparation system. More specifically, the relocatable oil sand slurry preparation system comprises a relocatable rotary digester for forming an oil sand slurry free of oversize rejects and a relocatable rejects recirculation unit for receiving the oversize rejects and delivering the rejects back to the rotary digester for further digestion therein. Preferable, relocatable oil sand slurry preparation system further comprises a rejects crusher for crushing oversize rejects prior to delivering them back to the rotary digester.
BACKGROUND OF THE INVENTION
[0002] Oil sand, such as is mined in the Fort McMurray region of Alberta, generally comprises water-wet sand grains held together by a matrix of viscous bitumen. It lends itself to liberation of the sand grains from the bitumen, preferably by slurrying the oil sand in heated process water, allowing the bitumen to move to the aqueous phase.
[0003] For many years, the bitumen in the McMurray sand has been commercially removed from oil sand using what is commonly referred to in the industry as the “hot water process”. The oil sand is strip-mined and conveyed on belt conveyors, often several kilometres in length, to an extraction plant. At the extraction plant, the oil sand is mixed with hot water (95° C.) and a small amount of caustic in a rotating horizontal drum or tumbler, where oil sand conditioning occurs. Here, the larger lumps of oil sand are ablated or digested and the released bitumen flecks coalesce and attach to air bubbles (referred to as “conditioning”). On leaving the tumbler, the conditioned slurry is diluted with additional hot water and retained under quiescent conditions for a prolonged period in a primary separation vessel (“PSV”), where the bitumen forms a froth that rises to the top of the vessel.
[0004] However, use of belt conveyors extending from the mine site to the extraction plant produced a number of problems. First, belt conveyors are expensive to install, operate and maintain. Further, as the mining area increases in the Fort McMurray region, the location of mining faces became more and more remote from the extraction plant, requiring more and longer belt conveyors to transport the mined oil sand.
[0005] The introduction of a pipeline to convey an aqueous slurry of the oil sands from the mine site to the extraction plant was a major advancement in the art. Surprisingly, it was found that much of the oil sand slurry conditioning takes place during transport of the slurry through the pipeline. Hence, the pipelined slurry could be fed directly to the PSV, thereby eliminating the need for large tumblers at the extraction plant. Nevertheless, the oil sand must still be satisfactorily blended with heated water at the mine site to produce a slurry capable of being conveyed through a pipeline (referred to as “pumpable slurry”) for transport and conditioning therein.
[0006] One slurry preparation system for producing pumpable slurry is referred to as the mixer circuit and is taught in Canadian Patent No. 2,000,984 and U.S. Pat. No. 5,264,118. The stationary mixer circuit comprises a vertically oriented mixer vessel forming a cylindrical, open-topped mixing chamber. A vortex is formed in the mixing chamber by tangentially feeding recycled slurry and to this rotating vortex is added oil sand and fresh water. However, the residence time in the mixer circuit is short (e.g., less than 30 seconds), resulting in a higher than desirable number of larger oil sand lumps, which are incapable of being pumped through the pipeline, and as such have to be removed. Further, the mixer circuit is very large and not amenable to being readily moved.
[0007] There is a need for an efficient oil sand slurry preparation system comprising a slurry preparation means for suitably digesting oil sand lumps to produce a pumpable oil sand slurry and a means for recycling oversize rejects, which rejects include large oil sand lumps, back to the slurry preparation means for further digestion, thereby reducing the overall amount of oversize rejects remaining. Preferably, the system is relocatable and can be periodically moved from location to location as the mine face advances.
[0008] Thus, the present invention is directed towards a relocatable oil sand slurry preparation system, which satisfactorily blends the oil sand with heated water to yield a consistent, dense (e.g., 1.5-1.65 g/cc), aerated oil sand slurry that is amenable to pipeline conveyance while substantially reducing the overall amount of oversize rejects.
SUMMARY OF THE INVENTION
[0009] In accordance with the invention, a relocatable rotary digester is provided for producing an aqueous oil sand slurry amenable to pipeline conveyance (i.e., a pumpable slurry), comprising:
a rotatable drum arranged for rotation about a substantially longitudinal axis of the drum, said rotatable drum having a feed end for receiving oil sand and water, a slurrying chamber for slurrying the oil sand and water and digesting oil sand lumps, and a trommel or cylindrical screen end for screening out oversize lumps of oil sand, rocks, lumps of clay and the like from oil sand slurry which falls through the trommel screen; a plurality of lifters longitudinally arranged in the slurrying chamber for lift-drop crushing and ablating oil sand lumps during slurrying; and a drive means operably engaged with the rotatable drum for rotating the rotatable drum about the substantially longitudinal axis of the drum.
[0013] By “pumpable slurry” is meant an aerated oil sand and water slurry having a density of about 1.4 to about 1.65 g/cc which is devoid of any material having any dimension greater than about 2″ to about 4″, such as oil sand lumps, rocks, lumps of clay and the like.
[0014] By “rejects” or “oversize rejects” is meant undigested oil sand lumps and other material such as rocks, clay lumps and the like, all of which have a dimension greater than about 2″ to about 4″.
[0015] The relocatable rotary digester provides a retention time for the oil sand and water in the slurrying chamber that is sufficiently long to assure adequate oil sand lump digestion/ablation. Residence time is preferably 1 minute or longer.
[0016] In one embodiment, the relocatable rotary digester further comprises propulsion means such as crawlers, flat skids or wheels for assisting in the relocation of the digester closer to the mine face as the mine face progresses.
[0017] In another embodiment, the relocatable rotary digester further comprises a plurality of ejectors arranged in the slurrying chamber of the rotatable drum near the trommel screen end for assisting in the removal of oil sand slurry and ejecting oversize rejects from the drum, said ejectors preferably comprising a plurality of individual scoop flights.
[0018] In another embodiment, the internal lifters are perforated for sifting preferably larger lumps and aerating the oil sand slurry.
[0019] Further in accordance with the invention, an oil sand slurry preparation system is provided for preparing a pumpable oil sand slurry while producing minimum overall rejects, comprising:
a slurry preparation means for slurrying oil sand and water and digesting oil sand lumps, said slurry preparation means comprising means for screening out oversize rejects to produce pumpable oil sand slurry; and a rejects recirculation unit operably associated with the slurry preparation means for receiving oversize rejects and delivering said rejects back to the slurry preparation means for further digestion.
[0022] In a preferred embodiment, the oil sand slurry preparation system further comprising a crushing means or impactor for crushing and comminuting the screened rejects prior to delivering them back to the rotary digester.
[0023] In one embodiment, the rejects recirculation unit of the oil sand slurry preparation system comprises a plurality of belt conveyors. In another embodiment, the rejects recirculation unit comprises a spiral lift pump.
[0024] In another embodiment, a relocatable oil sand slurry preparation system is provided for preparing a pumpable oil sand slurry while producing minimum overall rejects, comprising:
a relocatable rotary digester for slurrying oil sand and water to form a pumpable oil sand slurry, said rotary digester having a feed end for receiving the oil sand and water, a slurrying chamber comprising a plurality of lifters for slurrying the oil sand and water and digesting oil sand lumps, and a trommel screen end for screening out oversize rejects from the oil sand slurry which falls through the trommel screen; and a relocatable rejects recirculation unit operably associated with the rotary digester for receiving oversize rejects and delivering said rejects back to the rotary digester for further digestion.
[0027] In a preferred embodiment, the relocatable oil sand slurry preparation system of the present invention further comprises a crushing means or impactor for crushing and comminuting the screened rejects to a smaller size prior to delivering them back to the rotary digester.
[0028] In one embodiment, the rejects recirculation unit comprises a plurality of belt conveyors. In another embodiment, the rejects recirculation unit comprises a spiral lift pump.
[0029] In a further preferred feature, the relocatable oil sand slurry preparation system further comprises a metal detector for detecting any metal objects in the screened rejects, such as broken teeth from oil sand excavating shovels, prior to recirculating the rejects via the rejects recirculation unit back to the rotary digester.
[0030] In a preferred embodiment, the relocatable oil sand slurry preparation system further comprises a pump box positioned beneath the trommel screen end for receiving the pumpable slurry. The pump box is connected to a pump, which pumps the oil sand slurry through a pipeline of sufficient length to further condition the slurry.
[0031] The mined dry oil sand is preferably delivered to the rotary digester of the relocatable oil sand slurry preparation system from the mine site by means of a plurality of belt conveyors. In one embodiment, the mined dry oil sand is first conveyed to a mixing box operably associated with the rotary digester. Water is then added to the mixing box and the water and oil sand mixture is delivered to the rotary digester for further slurrying and lump ablation in the slurrying chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a perspective view of the relocatable rotary digester in accordance with an embodiment of the invention.
[0033] FIG. 2 shows the interior of the rotatable drum of the rotary digester to display internal lifters, rock ejectors and trommel screen.
[0034] FIG. 3 is a perspective view of one of the perforated lifters.
[0035] FIGS. 4 a and 4 b show rock ejectors of the present invention, wherein 4 a is a frontal view of the discharge end of the rotary digester where trommel screen has been removed to show rock ejectors and 4 b is a cross-sectional view of the rotary digester showing the rock ejectors.
[0036] FIG. 5 is a perspective view of one embodiment of the oil sand slurry preparation system comprising belt conveyors and an impactor crusher.
[0037] FIG. 6 is a perspective view of another embodiment of the oil sand slurry preparation system comprising a shuttle conveyor, metal detector, reject crusher and spiral lift pump.
[0038] FIG. 7 is a perspective view of the spiral lift of FIG. 6 showing part of the cylinder wall broken away to display the internal screw.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] An embodiment of a slurry preparation means of the slurry preparation system according to the invention is illustrated in FIG. 1 . In this embodiment, the slurry preparation means is a rotary digester generally designated 10 , which comprises a rotatable drum 12 arranged for rotating about a substantially longitudinal axis of the drum. Rotatable drum 12 comprises a feed end 14 , a slurrying chamber 16 and a discharge end 18 . In a preferred embodiment, as shown in FIG. 4 a , discharge end 18 comprises a lip 19 for controlling the flow of oil sand slurry from the rotary digester 10 .
[0040] Operably associated with feed end 14 of drum 12 is a mixing box 20 where mined dry oil sand and water are first pre-mixed. Mined dry oil sand is delivered to mixing box 20 by means of feed conveyor 52 . The oil sand/water mixture from the mixing box 20 is then delivered to rotatable drum 12 via feed end 14 and tumbled within slurrying chamber 16 of rotatable drum 12 for further slurrying and processing/digestion of larger lumps of oil sand to produce oil sand slurry.
[0041] Discharge end 18 of rotatable drum 12 further comprises a trommel screen 22 for screening out any oversize oil sand lumps (e.g., lumps greater that about 2″ to about 4″ in any dimension) and other rejects still remaining in the oil sand slurry. Screened oil sand slurry (which is now referred to as pumpable slurry) is collected in pump box 24 and is pumped via pump 26 to pipeline 48 for further conditioning. In one embodiment, trommel screen 22 further comprises rejects chute 28 , which directs oversize lumps or rejects either to a discharge pile (not shown) or to a rejects recirculation unit as illustrated in FIGS. 4 and 5 .
[0042] Surrounding the outer circumference of rotatable drum 12 is a plurality of steel riding rings 30 that bear against tire drive means 32 . Tire drive means 32 comprises a plurality of rubber tires 34 and a drive means (not shown) and operates to rotate the rotatable drum along its horizontal axis. In one embodiment, crawlers 50 , located underneath the rotary digester support frame, assist in the relocation of the digester closer to the mine face as the mine face progresses. In another embodiment (not shown), the rotary digester is mounted on a flat skid allowing the entire structure to be lifted and relocated. It is understood that other propulsion means could also be used such as wheels.
[0043] With reference now to FIG. 2 , which shows the inside of rotatable drum 12 , a plurality of lifters 36 are arranged longitudinally within the slurrying chamber 16 of rotatable drum 12 for lifting and dropping oil sand lumps as the drum rotates so that most of the oil sand lumps will be broken, ablated and digested. The rotary digester is designed such that the residence time of the slurry in the rotatable drum 12 is in the order of about one to about three minutes, or longer.
[0044] Each lifter 36 comprises a plurality of gussets 38 mounted to the interior wall 40 of the slurrying chamber 16 of drum 12 , preferably at about a 45° angle, and a perforated plate 42 that is attached along its length to the free end of each gusset 38 , as shown in FIG. 3 . The perforated plate 42 comprises a plurality of perforations 44 , which are each about 4 inches in diameter and operate to selectively lift and drop lumps that are larger than 4 inches and to aerate the oil sand slurry each time the slurry contacts the perforated bar 42 .
[0045] Rotatable drum 12 further comprises a plurality of rock ejectors 46 attached to the interior wall 40 of the rotatable drum 12 near its discharge end 18 , as shown in FIG. 2 . The rock ejectors 46 , shown in more detail in FIGS. 4 a and 4 b , are comprised of scoop-like, curved projections which operate to pick up oil sand slurry and large lumps and rocks, and direct these materials out of the rotatable drum onto the trommel screen.
[0046] In operation, most oil sand lumps are digested in the rotary digester due to the effective multiple lifting/dropping, lump ablation and collateral attrition. Thus, the number of primary oversize rejects is reduced as compared to conventional slurry preparation units.
[0047] FIG. 5 shows one embodiment of the relocatable oil sand slurry preparation system of the present invention comprising rotary digester 10 and one embodiment of a rejects recirculation unit, said rejects recirculation unit generally designated 100 . Rejects recirculation unit 100 is operably associated with the rotary digester 10 for receiving rejects and delivering the rejects back to the rotary digester to be digested again. In this embodiment, rejects recirculation unit 100 comprises two belt conveyors, impactor feed conveyor 102 , which is reversible, and impactor discharge conveyor 104 .
[0048] Rejects are deposited onto impactor feed conveyor 102 by means of rejects chute 28 . Impactor feed conveyor 102 travels in the direction shown by arrow 56 and deposits the rejects into impact crusher or impactor 106 , where the rejects are crushed to a smaller size. The crushed rejects are then deposited onto impactor discharge conveyor 104 travelling in the direction shown by arrow 58 and delivered back to rotary digester 10 . In a preferred embodiment, the crushed rejects are first deposited into mixer box 20 where the crushed rejects are mixed with oil sand and water prior to being fed into the rotary digester 10 .
[0049] Impactor feed conveyor 102 can be equipped with a metal detector (not shown), which operates to protect the impactor 106 from metal objects that may be mixed in with the rejects. The direction of travel of the impactor feed conveyor 102 , which is normally towards the impactor 106 as shown by arrow 56 , will be reversed when the metal detector detects a metal object. Hence, the metal object can be discarded, along with a small quantity of rejects, thereby protecting the impactor 106 from damage that could be caused by the metal object.
[0050] Rejects recirculation unit 100 further comprises a plurality of wheels 108 which allow the unit to be relocatable, depending upon the location of the mine site.
[0051] Thus, in operation, oil sand is delivered to mixer box 20 via feed conveyor 52 . Preferably, heated water is added to mixer box 20 to pre-mix the oil sand with water. The oil sand and water is then delivered to the rotary digester 10 via feed end 14 and the oil sand and water is slurried in slurry chamber 16 with the assistance of a plurality of internal lifters. Oil sand slurry exits via discharge end 18 with the assistance of rock ejectors and the slurry is delivered onto the internal surface of trommel screen 22 where rejects are screened out from the pumpable oil sand slurry which falls through the trommel screen.
[0052] Pumpable oil sand slurry passes through trommel screen 22 into pump box 24 and is pumped via a pump through a pipeline for further conditioning. Rejects remaining on the inside surface of trommel screen 22 are delivered via rejects chute 28 to impactor feed conveyor 102 . Conveyor 102 then delivers the rejects to impactor 106 where rejects are crushed and comminuted to smaller size. Crushed rejects are then deposited onto impactor discharge conveyer 104 and delivered back to the mixer box 20 for further digestion in the rotary digester 10 .
[0053] FIG. 6 shows another embodiment of the relocatable oil sand slurry preparation system of the present invention comprising rotary digester 10 and another embodiment of a rejects recirculation unit, which is generally designated 200 . Rejects recirculation unit 200 is operably associated with the rotary digester 10 for receiving rejects and delivering the rejects back to the rotary digester to be digested again. In this embodiment, rejects recirculation unit 200 comprises a spiral lift 202 operated by variable speed drive 204 .
[0054] Oversize lumps or rejects, which do not pass through trommel screen 22 , drop onto shuttle conveyor 206 , a reversible conveyor, travelling in a forward direction as indicated by arrow 208 . Rejects are then dropped into reject crusher or impactor 210 , which in this embodiment comprises double rollers, crushed to a smaller size and the crushed rejects are then dropped into crushed reject sump 212 , where water is added to produce a dense slurry of crushed rejects and water. Operably associated with reject sump 212 is spiral lift 202 , which rotates by means of drive means 204 .
[0055] In a preferred embodiment, shuttle conveyor 206 is equipped with a metal detector (not shown) to protect the impactor 210 from receiving metal objects that may be mixed in with the rejects. The direction of travel of the shuttle conveyor 206 , which normally is in the direction as shown by arrow 208 , will be reversed when the metal detector detects a metal object. Hence, the metal object, along with a small pile of rejects, can be discarded and thus protect the impactor 21 0 from damage. Alternatively, a mechanically operated flip-chute may be used to discharge a metal object with a small quantity of reject outside the crusher.
[0056] Thus, in operation, oil sand is delivered to mixer box 20 via feed conveyor 52 . Preferably, heated water is added to mixer box 20 to pre-mix the oil sand with water. The oil sand and water is then delivered to the rotary digester 10 via feed end 14 and the oil sand and water is slurried in slurry chamber 16 with the assistance of a plurality of internal lifters. Oil sand slurry exits via discharge end 18 with the assistance of rock ejectors and the slurry is delivered onto the internal surface of trommel screen 22 where rejects are screened from the pumpable oil sand slurry.
[0057] Pumpable oil sand slurry passes through trommel screen 22 into pump box 24 and is pumped via pump 240 through a pipeline for further conditioning. Rejects remaining on the inside surface of trommel screen 22 are dropped onto shuttle conveyor 206 . Conveyor 206 then delivers the rejects to a crusher/impactor 210 where rejects are crushed and comminuted to smaller size. Crushed rejects are then deposited into crushed reject sump 212 and water is added to form a crushed rejects slurry. Spiral lift 202 , which is rotated by drive means 204 , delivers crushed rejects slurry back to the mixer box 20 for further digestion in the rotary digester 10 .
[0058] A side view of spiral lift 202 is shown in FIG. 7 . Spiral lift 202 is an Archimedes screw and comprises cylinder 214 having an open bottom end 216 and a top end 218 and an integral, primarily internal, single-pitch helical auger or spiral screw 220 . The spiral lift 202 is designed to be able to “pump” or lift slurries ranging in densities from about 1.44 to about 1.78 kg/litre (70% solids concentration by mass). The helical flights of spiral screw 220 are oriented perpendicularly to the cylinder wall and are continuously welded to the interior surface of cylinder 214 to give a single, rigid, revolving unit.
[0059] Top end 218 further comprises a labyrinth seal 222 and anti-splatter containment 224 . Spiral lift 202 further comprises support bearings 226 and 228 at the lower and upper ends of the spiral lift 202 , respectively. The lower support 226 comprises a garland of rollers for supporting the rotating cylinder 214 and preventing it from accidental lifting, but still allowing it the axial movement. The upper support 228 comprises a thrust bearing to support the main shaft of cylinder 214 both vertically and axially. Spiral lift 202 further comprises drive means 204 , which is located at the upper end of spiral lift 202 , for rotating the cylinder 214 .
[0060] The bottom portion of screw 220 extends past open bottom end 216 and is submerged in the relatively dense slurry of crushed rejects and water, which is present in crushed reject sump 212 . The exposed portion of screw 220 acts as an inducer to mix the crushed rejects with water and feed the crushed rejects slurry to the spiral lift 202 , which then lifts it further into mixing box 20 . As the spiral lift rotates, the slurry from the sump 212 fills the pockets formed between the bottom end 216 of the cylinder 214 and the helical spiral flights. Although there is no relative movement between the spiral screw 220 and the cylinder 214 , the geometry of the rotating spiral lift causes slurry pockets to travel up the cylinder and discharge at the top end 218 of cylinder 214 . The pumping rate is proportional to the rotational speed, up to a point at which centrifugal forces start to interfere with the slurry settling within the pockets.
[0061] Use of the spiral lift 202 to return crushed, oversize reject slurry to the rotary digester allows for construction of smaller, more compact oil sand slurry preparation units, with the added advantage of extended digestion of oil sand lumps and the ability to be relocated closer to the mine site as the mine site advances.
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A relocatable oil sand slurry preparation system is provided for preparing an aqueous oil sand slurry amenable to pipeline conveyance while producing minimum overall rejects, comprising (a) a relocatable rotary digester for slurrying oil sand and water and digesting oil sand lumps to form a pumpable slurry, the rotary digester having a feed end for receiving oil sand and water, a slurrying chamber comprising a plurality of lifters for slurrying the oil sand and water, and a trommel screen end for screening out oversize rejects from the oil sand slurry which falls through the trommel screen; and (b) a relocatable rejects recirculation unit operably associated with the rotary digester for receiving oversize rejects and delivering the rejects back to the rotary digester for further digestion. In a preferred body, relocatable oil sand slurry preparation system further comprises a rejects crusher for crushing oversize rejects prior to delivering rejects back to the rotary digester.
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