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RELATED APPLICATION
[0001] Provisional Application No. 61/6808949 dated Aug. 8, 2012, “A Robotic Equipment for Automated Sample Harvesting and Analysis, using a 6-axis robot arm and a micro-gripper”, assigned to: COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES; inventors: LARIVE Nathalie, FERRER Jean-Luc, VERNEDE Xavier, HEIDARI KHAJEPOUR Mohammad Yaser.
BACKGROUND OF THE INVENTION
[0002] The resolution of protein structures by X-ray crystallography involves numerous steps. In the recent years, most of these steps such as protein purification (Kim et al., 2004, J. Struct. Funct. Genomics 5, 111-118), crystallization (Mueller-Dieckmann, 2006, Acta Cryst. D62, 1446-1452) and also data collection and processing have been mostly automated (Adams et al., 2011, Methods 55, 94-106; Ferrer, 2001, Acta Cryst. D57, 1752-1753; Manjasetty et al., 2008, Proteomics 8, 612-625). The critical step remains the harvesting of crystals from their crystallization drop, for crystals grown using the vapor diffusion method (McPherson, 1989, Preparation and analysis of protein crystals, Malabar, USA: Krieger Publishing Company), followed by the cryo-protection and freezing steps. These three steps are still performed manually, which is a real bottleneck to high-throughput crystallography and a limitation in the remote use of protein crystallography core facilities.
[0003] Due to their solvent content, ranging from 20% to more than 80%, protein crystals are very fragile and easily damaged due to variation of temperature and ambient humidity or mechanical stress. Considering also the small dimensions of protein crystals (from ˜10 μm to ˜500 μm), it is particularly difficult not to damage the crystal with manual harvesting. Furthermore with high throughput “nanodrops” crystallization robots mostly used nowadays, crystals grow even smaller, rather in the ˜5 μm to ˜50 μm range. In situ diffraction in the crystallization drop at room temperature is an alternative to crystal harvesting (Jacquamet et al., 2004, Structure 12, 1219-1225). Nevertheless because of limitations due to crystal symmetry and crystal degradation during beam exposure at room temperature, harvesting and freezing samples remain in many cases necessary.
[0004] Within the past few decades the most commonly used method to harvest protein crystals has been manual handling using micro loops (Teng, 1990, J. Appl. Cryst. 23, 387-391, and U.S. Pat. No. 8,210,057). Nowadays on high throughput protein crystallization setups, crystals are produced in micro to nano-litter drops dispensed with pipeting robots on 96-well microplates. Manipulating into these drops with micro-loops requires dexterity, due to the geometry of the microplates. Moreover, crystals are visualized through a binocular. Harvesting crystals in this configuration is very challenging since the microscope blocks an easy access to the drop. When the volume of crystallization drops is reduced, fast manipulation is mandatory to avoid drop evaporation. At the same time, manipulating crystals requires high delicacy and sharpness, especially when crystals are very small. Protein crystals with all their fragility have to be hanged in the loop liquid while taking out the loop from their crystallization drop. But crystals can be trapped in a skin at the surface of the drop, or stuck at the bottom of the well. In this last case, crystals are tapped to be removed from the bottom. In these difficult situations, manual harvesting stresses the crystal and could harm or even destroy the crystal. Thirdly, once the crystal is harvested on a loop it has to be transferred into a cryo-protecting solution before freezing (Parkina & Hope, 1998, J. Appl. Cryst. 31, 945-953). Consequently, in most cases, the crystal will be released into the cryo-protecting drop and it has to be harvested once again. All these manual operations increase the difficulty of the task and also the risk to damage the crystal even more. Finally, crystals must be flash-cooled to avoid ice formation (Kriminski et al., 2002, Acta Cryst., D58, 459-471) and kept at a temperature below 140 K (Garman & Schneider, 1997, J. Appl. Cryst. 30, 211-237). The most traditional methods are to immerse the loop into liquid nitrogen (77 K) or to expose the loop to a 100 K nitrogen gas stream. The reproducibility of these operations is quite random when performed manually (Warkentin et al., 2006, J. Appl. Cryst. 39, 805-811).
[0005] In addition to this, all the delicate steps described above are now to be performed at an increasing speed, because of the growing demand for protein crystallography data, especially for drug design. Therefore, automation and remote access to crystallography setups has become a strategic goal for laboratories, as illustrated by the emergence of beamlines coupled to crystallization platforms, or hig technology core facilities shared by several laboratories.
[0006] At least four different automated harvesting systems for protein crystals have been developed in the last decade:
1) one with a two-finger manipulator system (Ohara et al., 2004, Proceedings of the 2004 International Symposium on Micro-Nanomechatronics and Human Science, 301-306), using a loop, where the two-finger manipulator is used to push the sample into the loop inside the drop, the extraction of the sample from the drop being performed with the loop, 2) another with a traditional harvesting loop on a 6-axis robot arm (Viola et al., 2011, J. Struct. Funct. Genomics 12, 77-82), 3) the “Crystal Harvester”, that uses two motorized loops (BrukerAXS), 4) the last one consists in a series of micro-manipulators aimed at protein crystals seeding and a loop for harvesting (Georgiev et al., 2004, IEEERSJ International Conference on Intelligent Robots and Systems IROS; Vorobiev et al., 2006, Acta Cryst. D62, 1039-1045).
[0011] Even though these systems provide better accuracy and no vibration compared to human manipulation, they haven't been successful because of lack of reliability and compatibility issues to standard materials and procedures. Furthermore, none of these systems actually perform the harvesting, the preparation and the analysis of the samples using one single setup, with no need to transfer the samples to another setup.
[0012] Several examples of grippers used for sample handling exist in the literature. Specifically, a system using a gripper with soft-ending elements to manually handle cells in their medium has been described by Chronis and Lee (Chronis and Lee, 2005, Journal of MicroElectro Mechanical Systems, 14, 857-863). But none of these systems are used for the harvesting of fragile samples, such as protein crystals, because of the risk to break or deteriorate the sample upon extraction from its medium.
[0013] The simultaneous use of a robot for holding a protein crystal and positioning it in an X-ray beam, for example, has been reported in U.S. Pat. No. 6,408,047. But in such a system the sample is manually harvested, and mounted on a holder, prior to the automatic data collection operation.
[0014] It is an object of this invention to provide a micro-gripper comprising tweezers with an aperture range from 0 to 1 mm, designed to harvest sub millimeter samples, either manually or in an automated way, that is reliable and compatible with standard materials and procedure, and that can be directly used to position the sample for further analysis.
[0015] It is a further object of this invention to provide such a micro-gripper in which the tweezers are made of soft ending elements that prevent the deterioration of fragile samples such as protein crystals, these soft ending elements being either removable or permanent.
[0016] It is a further object of this invention to provide such a micro-gripper in conjunction with a robotic arm, used for the extraction, preparation and analysis of samples without releasing the samples between the different steps.
[0017] It is a further object of this invention to provide a method of performing crystallography experiments, comprising
a step of extracting a small sample from a medium using a gripper with tweezers, said gripper being mounted at the end of a robot arm or used manually a step of sequential transfer of the sample to preparation an optional step of preparation of said sample a step of analysis (performing x-ray crystallography) the said extracted sample
[0022] In the method according to the invention, the sample is preferably not released between the different steps.
[0023] During the step of analysis, an X-ray beam may be used, the sample being positioned by the robot, after some preparation steps.
BRIEF SUMMARY OF THE INVENTION
[0024] The present invention consists in a micro-gripper, with an aperture range from 0 to 1mm that is mounted on a robot arm, so that the sample can be transferred to different environments, in order to prepare it, and to present it to a specific setup for direct analysis. This merges in a unique way the “harvesting”, the “preparation” and the “analysis” operations. This gripper can be equipped, if required, with soft, removable, ending elements to handle samples as fragile as protein crystals. These ending elements are simple, easy to mount or dismount, which gives the possibility to adapt them to the type of samples to be manipulated.
[0025] All these operations start from a sample in its production or storage medium, with no need to pre-load the sample on a specific holder.
[0026] All these operations can be done manually, or remotely controlled by the user or even fully automated, depending on the difficulty to identify samples in their medium.
[0027] The present innovation is based on a highly flexible design. Indeed, the invention can be used:
in various fields of application, and therefore for various types and sizes of samples (small/medium molecule crystals or aggregates, macromolecule crystals or aggregates, quasi-crystals, partially ordered crystals, fibers, etc.), as well as various types of medium in which they are stored or produced (gel, liquid, dry support, etc.), no matter the function to be accomplished for the preparation steps, when required, or the means to accomplish them (soaking, heating, cooling, freezing, exposure to electric/magnetic fields, etc.), and the analysis methods (diffusion, diffraction, absorption, spectroscopy, etc.),
[0030] the gripper can be a piezoelectric, mechanical, or thermoelectric actuator, but not limited to these elements. The ending elements, or jaws, when needed, can be made of a polymer, with a thickness from about 10 microns to about 100 microns. Choice of material can be SU-8, Kapton™, Mylar™, polyester, polystyrene, polyolefin film, but not limited to these. And the robot arm can be anything from a 3 to 7 axis, with cartesian, scara or anthropomorphic geometry.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0031] FIG. 1 is a schematic representation of the elements of the micro-gripper. This embodiment comprises an actuator 1 on which ending elements 2 are attached, in order to grab sub-millimeter size sample 3 .
[0032] FIG. 2 is a schematic representation of an automated system made of a robotic arm equipped with the micro-gripper object of the invention, as shown during the sample harvesting operation. This embodiment comprises a robotic arm 4 equipped with the micro-gripper 5 (scaled up for a better understanding). The micro-gripper is presented while it grabs the sample 6 in its medium 7 .
[0033] FIG. 3 is a schematic representation of an automated system made of a robotic arm equipped with the micro-gripper, as shown during the sample analysis operation. This embodiment comprises a robot arm 4 equipped with the micro-gripper 5 (scaled up for a better understanding). The gripper is presented while it handles the sample 6 for analysis, via the exposition into a X-ray beam for example 8 .
DETAILED DESCRIPTION OF THE INVENTION
[0034] The present innovation is illustrated in the specific situation of protein crystallography. In such a situation, the sample is a protein crystal, the medium is the crystallization drop where the crystal has grown, the subsequent preparation steps are cryoprotection and freezing, and the analysis setup is a X-ray diffraction equipment. This system is a good example of the present innovation considering the specific challenging domain of protein crystallography. However, the innovation is not limited to this area, and only minor modifications of the overall system would be required to adapt it to a specific situation, the general layout of the robot arm equipped with a microgripper and ending elements remaining unchanged.
[0035] The embodiment of the present invention described here is a micro-gripping device equipped with tweezers and mounted on a robotic arm, that allows to perform crystal harvesting, cryo-protection and freezing in an automated or remotely-driven way. With this set-up, harvesting experiments were performed on several crystals, followed by direct data collection using the robot arm as a goniometer. Analysis of the diffraction data demonstrated that this system is highly reliable and efficient, and does not alter crystallography data. This is a surprising result, as gripping a protein crystal to move it through the surface of a drop has always been considered by experts in the field as extremely risky. Therefore, this new gripper provides the last step towards full automation of crystallography experiments and fills the gap of the high-throughput crystallography pipelines.
[0036] Surprisingly, it was found out that, contrary to what all the experts in crystallography thought, using proper tweezers to handle crystals did not break them. In the experiments presented here, a micro-gripper comprising tweezers from Percipio-Robotics, is used. Each finger of the tweezers has two degrees of freedom that are remotely controlled with a resolution of 1.0 μm and a reproducibility of 0.1 μm. By combining symmetrical translations of both piezo-electrical fingers, an opening gap range from 0 μm to 500 μm is obtained. The ending elements in contact with crystals are manufactured separately from the two-finger actuator. The material used for these ending elements is called SU-8 (Ling et al., 2009, Microsyst. Technol. 15, 429-435). SU-8 is known to produce a very low scattering background in X-ray. Comparing to other common materials used for the fabrication of crystal harvesting loops, the SU-8 shows a background scattering in X-ray exposure between Kapton™ and nylon. The ending elements geometry was designed to provide the best possible grip on crystals and the lowest volume of SU-8 exposed to the X-ray, in order to further minimize scattering for future data collection. We chose to reduce the thickness of the ending elements in order to bring enough flexibility to limit the stress on crystals. The level of reduced thickness appropriate to avoid breaking the crystals was totally unknown and never described or even imagined possible by the experts in the field. During the experiments, we realized that the thickness chosen when designing the ending elements quite surprisingly enabled us to actually grab the crystals without breaking them in the process.
Materials and Methods
[0037] In the experiments, 14.4 kDa lysozyme protein from hen egg-white (Roche, Reference number: 10837059001) was crystallized by mixing 500 nL of a 50 mg/mL protein solution in 0.24% (w/w) acid acetic with 500 nL of 5% NaCl (w/v) reservoir solution. The 56.3 kDa NikA protein from E. coli was also used. Its cytoplasmic apo form was expressed and purified as previously described in Cherrier and coworkers (Cherrier et al., 2008, Biochemistry 47, 9937-9943). A 10 mg/mL apo-NikA solution was pre-incubated overnight at 4° C. with 2 molar equivalent of FeEDTA and this protein-ligand complex was crystallized by mixing 0.5 μL of this solution with 0.5 μL sodium acetate 0.1 M pH 4.7, ammonium sulfate 1.5 to 1.95 M reservoir solution (Cherrier et al., 2005, J. Am. Chem. Soc. 127, 10075-10082). Protein samples were crystallized on CrystalQuick™ X plates, a vapor diffusion sitting drop microplate (Bingel-Erlenmeyer et al., 2011, Cryst. Growth Des. 11, 916-923). CrystalQuick™ X has been developed especially for in situ screening by Greiner Bio-One and the FIP-BM30A group. CrystalQuick™ X is a SBS-standard 96-Well microplate plate, with two flat wells for sitting drops per reservoir. The geometry of this plate gives a better access to drops for crystal manipulation. Wells are 1.3 mm deep in CrystalQuick™ X plate, whereas other wells of other plates range from 3 mm to 4 mm deep.
[0038] In our experiment, plates were filled manually, after which they were screened for pairs of crystals grown in the same drop. For each pair, one of the two crystals was manually harvested, cryo-protected and flash-cooled using LithoLoops™ (from Molecular Dimensions) and the other one went through the same steps using the micro-gripper object of the present invention. Comparison between the two methods is described further.
[0039] Experiments were led on beamline FIP-BM30A (Roth et al., 2002, Acta Cryst. D58, 805-814) at the ESRF. This beamline uses a bending magnet as a source and delivers a monochromatic beam with an intensity of 5 e 11 photons/(0.3×0.3 mm 2 )/s for 2×10 −4 energy resolution at 12.5 keV. In these experiments the beam size was defined at 0.2 mm×0.2 mm. An ADSC Q315r CCD detector was used for the recording of the diffraction frames. The goniometer used for these experiments was the G-Rob system, commercialized since 2009 by NatX-ray (www.natx-ray.com). G-Rob is a multi-task robotic system based on a Stäubli 6-axis robot arm, developed on beamline FIP-BM30A at the ESRF (Grenoble, France). G-Rob is accurate enough to operate as a goniometer (Jacquamet et al., 2009, J. Synchrotron Rad. 16, 14-21). It is able to collect X-ray diffraction data with a sphere of confusion smaller than 15 μm radius for frozen samples and capillaries. This setup is completed with a fully motorized visualization bench equipped with an inverted microscope and a three-direction motorized microplate holder.
[0040] On G-Rob, two motorized translations are installed at the end of the robot arm to center each sample on the 6th axis of the robot which is used as the spindle axis. In the following experiments, this centering operation is done only once, when G-Rob holds its micro-gripper tool before the harvesting operation. In so doing, once the crystal is transferred to the spindle position, it is already centered into the beam with a positioning error less than 10 μm. Thus X-ray diffraction data can be collected right away.
[0041] For these experiments the on-axis microscope is used to define the spindle position and to center the samples in the beam. The two centering translations on the robot arm were used to initially center the ending elements of the micro-gripper on the G-Rob spindle axis, or for the manual experiment, to center individually each harvested sample. For each sample, X-ray diffraction data were collected with 1° oscillation at 0.98 Å wavelength.
[0042] The experiment consisted in doing the harvesting manually, followed by data collection and analysis using the set-up available on FIP-BM30A beamline, and to compare that with the inventive method using the micro-gripper, followed by the same data collection and analysis as in the manual harvesting. In order to assess the impact of the stress inflicted on crystals with the micro-gripper, series of tests of harvesting, cryo-protection and flash-freezing were led manually and with the invention. With the invention, crystals are directly exposed in the X-ray beam (“direct data collection”) after being grabbed by the micro-gripper, in order to evaluate the gripping influence on crystals structure. Two pairs of crystals from the same wells of each protein were chosen and prepared for diffraction data collection with G-Rob, in both the manual and the invention (see Table 1 and 2).
[0043] In the manual method, crystals were visualized using a classical laboratory binocular and were manually harvested with SPINE standard loops (Hampton Research, reference number: HR8-124). Crystals were then soaked into the cryo-protecting solution (25% w/w Glycerol and reservoir solution) for about 20 to 30 seconds and flash-cooled into a 100 K temperature nitrogen gas stream generated by a Cryostream 700 system (Oxford Cryosystem).
[0044] In the present embodiment of the invention, crystallization plates were screened using an inverted microscope associated with a computer with a Graphical User Interface (GUI). In order to do that, a drop of the appropriate cryo-protecting solution is disposed over the crystallization drop. A button on the GUI enables to take the micro-gripper over the visualized well. The control of the robot and micro-gripper is enabled through the GUI and a game pad. Thanks to the 6-axis arm of the G-Rob, the micro-gripper is capable of three translations and two rotations movements. Furthermore the opening and closing control of the micro-gripper is integrated in the GUI and in the game pad buttons.
[0045] First, the motorized translations and zoom of the inverted microscope are used to center crystals in the microscope and to adjust the focus. Then the user drives the movements of the G-Rob arm to approach the micro-gripper to the crystals. The lights are also controlled with the GUI to optimize vision quality. Once the crystal is captured between the two SU-8 ending elements of the micro-gripper ( FIG. 2 ), a button on the GUI transfers the crystal into the nitrogen gas stream with a fast, still safe trajectory to the spindle position. The trajectory of the robot in approach of the spindle position is programmed perpendicular to the 100 K stream with the robot's fastest speed to optimize the flash-freezing. The trajectory ends at a position where the crystal is already properly centered into the spindle position. Since the G-Rob does the goniometer task and the ending elements of the micro-gripper are transparent to X-ray, it is possible to proceed right away with data collection, without having to release the crystal and without the need for any human manipulation.
[0046] Diffraction data were processed using XDS (Kabsch, 2010, Acta Cryst. D66, 125-132) and scaled with SCALA (Evans, 2006, Acta Cryst. D62, 72-82) from CCP4 (CCP4, C.C.P.N 1994, Acta Cryst. D50, 760-763) or XSCALE from XDS. Phasing was performed by molecular replacement with PHASER (McCoy et al., 2007, J. of Applied Crystallogr. 40, 658-674) from CCP4 using 1LZ8 and 1ZLQ form Protein Data Bank (PDB) as starting models for lysozyme and NikA-FeEDTA, respectively. Refinement was performed using PHENIX (Adams et al., 2010, Acta Cryst. D66, 213-221). Root mean square deviation (RMSD) values were calculated on main chains using COOT (Emsley and Cowtan, 2004, Acta Cryst. D60, 2126-2132).
[0047] Comparative analysis of data reduction showed no significant differences in mosaicity, resolution limits and unit cell dimensions (Table 1). Unit cell volume comparisons of both manual and automated harvested samples (Table 2) also showed no significant difference. Nevertheless their comparison with PDB structures 1ZLQ and 1LZ8, respectively for NikA-FeEDTA and for lysozyme, showed variations from 1.4% to 3.6%. Diffraction data for lysozyme (PDB entry: 1LZ8) were collected at 120 K and not at 100 K. Thermal expansion cannot account for this difference. Indeed, calculations based on Tanaka, 2001, J. Mol. Liquids 90, 323-332, considering the crystal and solvent as water, show only 0.15% volume variation of each unit cell. Therefore the unit cell volume differences are due to the experimental setup discrepancy.
[0048] Data and refinement statistics are similar whatever the crystal harvesting method, robotic or manual. The RMSD values (Table 2) between the structures, based on main chain comparison, are weak and do not exceed 0.46 Å for both proteins. Thus, we can confirm that the stress on the crystals is controlled and that there is no structural rearrangement due to the use of the micro-gripper. Although it does not show in the data statistics, certainly due to the small number of crystals tested, there is a reduced amount of solvent around the crystal when harvested with the robot. It results in a reduced scattering. Indeed, the average background measured by XDS (INIT step), and normalized to 1 sec exposure time and 1 mA current in the ESRF ring, is 0.126 and 0.071 respectively for lysozyme and NikA-FeEDTA when crystals are harvested with the robot, whereas it is 0.154 and 0.174 when harvested manually.
[0049] For the experiments presented above, cryo-protectant was added to the drop prior to harvesting. The crystal held by the micro-gripper object of the invention can also be soaked into a cryo-protecting drop, without the need to release the crystal. The soaking time can be specified on the Graphical User Interface (GUI), so that the robot transfers the crystal to the spindle position automatically at the end of the soaking period.
Advantage of the Invention
[0050] In the experiment using the invention, high accuracy and stability in manipulating crystals in their crystallization drops were demonstrated. In particular, the invention significantly helped the harvesting of crystals stuck at the crystallization plate bottom. Crystals from 40 μm to 400 μm were manipulated and harvested successfully with the invention, even when grown in 96 well microplates in nano-drops.
[0051] The inventive system provided significant time reduction for the overall experiment, mainly because when using the robot, the harvested crystal is already mounted on the “goniometer” G-Rob and centered into the beam, thus ready for data collection. When using the manual method, the sample holder has to be transferred to the goniometer head, and the crystal centering operation is needed because the loop dimensions and the position of the crystal in the loop are random. This operation is typically very time consuming. As an example, in our experiment it took from one to two minutes per crystal. The robotic method brings a higher reliability and repeatability, facilitates harvesting of difficult crystals, and shows a time saving benefit when coupled to direct data collection. In addition to that, the crystals harvested using the invention coupled with a robotic arm were transferred with a reduced amount of mother liquid and cryo-protecting solution, as compared with crystals harvested with a loop. Therefore, no ice formation and reduced diffusion rings which induces a lower background in diffraction data- was observed with the inventive system in comparison with crystals on loop.
[0052] The present invention, when used in association with a robotic system, enables to remotely manage protein crystallography experiments, from crystallization assays to structure resolution. It also provides a novel and innovative method and means to further achieve complete high throughput automated pipelines for crystallography.
[0000]
TABLE 1
lysozyme
NikA-FeEDTA
Data set
Manual 1
Manual 2
Robotic 1
Robotic 2
Manual 1
Manual 2
Robotic 1
Robotic 2
Data collection
Wavelength
0.97955
0.97955
0.9795
0.9797
0.97969
0.97968
0.97967
0.97967
(Å)
Oscillation (°)
1
1
1
1
1
1
1
1
Range
60
90
69
110
75
110
90
90
Data reduction
Space group
P4 3 2 1 2
P4 3 2 1 2
P4 3 2 1 2
P4 3 2 1 2
P2 1 2 1 2 1
P2 1 2 1 2 1
P2 1 2 1 2 1
P2 1 2 1 2 1
Resolution
38.65-1.50
36.78-1.80
38.62-1.75
38.99-1.60
47.01-2.65
40.70-1.85
44.25-2.30
44.22-1.95
(last shell) (Å)
(1.58-1.50)
(1.90-1.80)
(1.84-1.75)
(1.69-1.60)
(2.75-2.65)
(1.95-1.85)
(2.40-2.30)
(2.05-1.95)
Completeness
84.7 (88.7)
100 (100)
99.9 (100)
99.7 (100)
97.4 (98.3)
97.9 (98.4)
98.6 (98.6)
97.3 (98.2)
(last shell) (%)
Reduction
Total
4948
73949
59671
125316
90500
380011
163609
267767
reflections
(11509)
(10330)
(8306)
(16597)
(9330)
(54747)
(19205)
(37037)
(last shell)
Unique
15560
10887
11761
15436
29023
83913
44557
71555
reflections
(2324)
(1548)
(1671)
(2201)
(3015)
(12171)
(5294)
(9924)
(last shell)
Redundancy
5.5 (5.0)
6.8 (6.7)
5.1 (5.0)
8.1 (7.5)
3.1 (3.1)
4.5 (4.5)
3.7 (3.6)
3.7 (3.7)
(last shell)
R sym a (last
4.9 (37.9)
5.5 (46.4)
8.8 (42.0)
5.8 (42.7)
12.4 (39.2)
4.7 (35.9)
5.6 (33.5)
5.3 (32.9)
shell) (%)
R pim b (last
2.2 (18.2)
2.3 (19.2)
4.3 (20.7)
2.2 (16.5)
8.7 (26.1)
2.6 (19.2)
3.7 (20.7)
3.5 (20.1)
shell) (%)
I/σ (last shell)
17.2 (3.9)
21.5 (4.1)
10.8 (4.5)
17.7 (3.8)
7.34 (2.92)
19.23 (4.40)
16.68 (4.35)
16.45 (4.51)
(I)
Mosaicity
0.247
0.401
0.331
0.376
0.190
0.317
0.318
0.234
Unit Cell (Å)
a = 77.31
a = 77.51
a = 77.30
a = 77.98
a = 86.28
a = 86.24
a = 86.24
a = 86.33
b = 77.31
b = 77.51
b = 77.30
b = 77.98
b = 94.02
b = 93.64
b = 93.74
b = 93.88
c = 36.97
c = 36.78
c = 36.89
c = 36.71
c = 123.3
c = 123.2
c = 123.4
c = 123.1
Refinement
Resolution
38.65-1.50
34.66-1.80
34.57-1.75
33.21-1.60
47.01-2.65
40.70-1.85
40.71-2.30
43.17-1.95
range (last
(1.59-1.50)
(1.89-1.80)
(1.84-1.75)
(1.65-1.60)
(2.74-2.65)
(1.87-1.85)
(2.35-2.30)
(1.98-1.95)
shell) (Å)
R work c (last
18.16 (22.45)
16.90 (21.34)
16.25 (20.0)
17.25 (21.72)
17.40 (22.95)
17.53 (27.20)
18.51 (25.34)
17.17 (25.63)
shell) (%)
R free d (last
20.21 (25.77)
21.61 (26.09)
19.74 (27.11)
19.37 (22.08)
26.91 (33.81)
21.55 (32.57)
25.47 (35.85)
21.65 (31.81)
shell) (%)
R.m.s.d bonds
0.006
0.007
0.008
0.008
0.008
0.007
0.008
0.008
(Å)
R.m.s.d angles
1.063
1.062
1.187
1.125
1.150
1.124
1.087
1.117
(°)
Reflections in
15534
10856
11725
15394
29015
83910
44550
71549
refinement
B factor
19.1
26.6
21.9
25.1
32.94
30.23
41.51
30.04
average (Å 2 )
Data and Refinement Statistics. Comparison of dataset statistics for lysozyme and NikA-FeEDTA crystals harvested either manually (named “Manual 1” and “Manual 2”) or with the invention (named “Robotic 1” and “Robotic 2”).
a R sym = Σ|I i − </>|/ΣI i where I i is the intensity of a reflection and </> is the average intensity of that reflection.
b R pym = (Σ(1/(n−1))Σ|I i − </>|)/Σ</>, where n is the number of observation of the reflection.
c R work = Σ||F obs | − |F calc ||/Σ|F obs |.
d R free is the same as R work but calculated for 5% data omitted from the refinement.
[0000] TABLE 2 Comparative RMSD on main chain (Å) Volume changes (%) Lysozyme 1LZ8 Manual 1 Manual 2 Robotic 1 Manual 1 Manual 2 Robotic 1 Manual 1 0.202 — — — — — — Manual 2 0.259 0.162 — — 0.00 — — Robotic 1 0.223 0.083 0.123 — 0.24 0.24 — Robotic 2 0.246 0.181 0.090 0.156 1.03 1.02 1.27 NikA-FeEDTA 1ZLQ Manual 1 Manual 2 Robotic 1 Manual 1 Manual 2 Robotic 1 Manual 1 0.321 — — — — — — Manual 2 0.364 0.219 — — 0.57 — — Robotic 1 0.470 0.289 0.210 — 0.24 0.33 — Robotic 2 0.332 0.207 0.124 0.243 0.25 0.32 0.01
Unit Cell Changes between manually and robotically harvested crystals. | The present invention relates to a micro-gripper comprising tweezers, designed to be used for the harvesting of fragile sub-millimeter samples from their production or storage medium. The tweezers may be equipped with removable soft ending elements to prevent the deterioration of the sample. When coupled to a robotic arm, this micro-gripper allows automated flow of operations in a continuous and automated process, from harvesting to sample preparation and analysis. The present invention is particularly used in X-ray crystallography. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates generally to a portable toy vehicle racing set and, in particular, to a battery-powered toy vehicle racing set in which the components are housed in a portable case which folds open for use.
Toy vehicle racing sets such as slot car racing sets and the like generally include a plurality of track sections which must be selectively coupled together to form the racing track. The track sections include conductive rails which are electrically coupled together when the track sections are coupled to provide a closed track surface. Generally, power is supplied from an electrical power source through a transformer which is coupled to a house wiring circuit through a conventional plug. The speed of the cars on the track is controlled by a hand controller which includes a rheostat which varies the voltage applied across the tracks. The toy cars include motors which are coupled to the wheels of the vehicle. Power is supplied from the wheels through contact shoes to the motor.
Such racing car sets come packaged in large boxes and a significant amount of time is required to properly set up the track before play can begin. Because of the amount of time required to set up such a track, it is often required to leave the track in set up condition to avoid the time consuming procedure of dismantling the track, and reassembly when use is desired. Components are often bent or broken during the assembly and disassembly procedure and the play value is reduced because of this cumbersome and time consuming set-up procedure. In addition, such sets are not considered to be portable because of the set up requirements.
It would be desirable to provide a portable toy car racing set which is formed as part of a carrying case in which the track sections are formed as part of the case. The present invention provides such a system.
SUMMARY OF THE INVENTION
Generally speaking, in accordance with the present invention, a portable toy vehicle racing set for use with at least one toy vehicle having a motor therein, is provided. The racing set includes a case having a first section with inner and outer surfaces and a second section with inner and outer surfaces. The first and second sections are pivotally coupled together to permit movement of the first and second sections from a closed position where the case is closed to an open position where the first and second sections lie side by side with the inner surfaces thereof being essentially co-planar. The first section includes a first predetermined track layout and the second section includes a second predetermined track layout. The first and second track layouts form a closed loop track when the case is open. The closed loop track defines at least one lane in which a toy vehicle can ride. The lane includes contacts for supplying power from a power source to the motor of the toy vehicle.
In a preferred embodiment, the case sections are molded from a plastic material and the contacts are formed by conductive rails which lie along the track. A battery powered hand-held controller is coupleable to the rails to provide voltage thereto. The controller may include distinct contact positions whereby either one or two batteries can be coupled to the track section to simulate varying speeds for the toy vehicle.
In addition, the case sections may be releaseably coupled such that additional track sections may be coupled therebetween to provide a larger track layout.
Accordingly, it is an object of the present invention to provide a portable toy vehicle racing set.
Another object of the present invention is to provide a toy vehicle racing set in which the track sections are formed by the inner surfaces of a portable case.
A further object of the present invention is to provide a toy vehicle racing set in which the toy vehicles are powered by a hand-held battery-powered controller.
A still further object of the present invention is to provide a portable toy vehicle racing set formed in the shape of a carrying case which is molded from a plastic material.
A still further object of the present invention is to provide a portable toy vehicle racing set with enhanced play value.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises features of construction, combination of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:
FIG. 1 is a perspective view of a portable toy car racing set constructed in accordance with a preferred embodiment of the present invention in which the open case is shown in phantom;
FIG. 2 is an enlarged sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is a top plan view of the toy vehicle racing set of the present invention with the case shown in open condition;
FIG. 4 is an enlarged sectional view taken along line 4--4 of FIG. 3;
FIG. 5 is an enlarged sectional view taken along line 5--5 of FIG. 3;
FIG. 6 is an enlarged sectional view taken along line 6--6 of FIG. 3;
FIG. 7 is an elevational view of a hand-held controller for use with the toy vehicle racing set of the present invention shown in open position;
FIG. 8 is a sectional view taken along line 8--8 of FIG. 7;
FIG. 9 is an enlarged sectional view of a toy vehicle shown riding on a track section taken along line 9--9 of FIG. 3;
FIG. 10 is a sectional view taken along line 10--10 of FIG. 9;
FIG. 11 is a bottom plan view of the under surface of one section of the case; and
FIG. 12 is a top plan view of an additional track section for use in conjunction with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is first made to FIG. 1 which depicts a toy vehicle racing set, generally indicated at 20, and constructed in accordance with a preferred embodiment of the present invention. Racing set 20 is formed as a carrying case 22 having a first case section 24 and a second case section 26.
First case section 24 includes a handle portion 25 and second case section 26 includes a handle portion 27 which together define a handle 28 used for carrying racing set 20. A releasable lock 30 defined by opening 32 formed in first case section 24 and latch 34 formed on second case section 26 is provided to lock the case in closed condition when such is desired.
Referring now to FIGS. 3 through 6, it is seen that first case section 24 includes an inner surface 40 which defines a first track section 42 having a first track 44 and a second track 46. Similarly, second case section 26 includes an inner surface 50 defining a second track section 52 which also defines a portion of a first track 44 and a second track 46. Track 44 is defined by a slot 60 formed in the inner surface 40 of first case section 24. First and second conductive rails 62 and 64 are positioned and fixed on opposite sides of slot 60. Second track 46 is likewise formed from a central slot 70 formed between parallel conductive rails 72 and 74 disposed on opposite sides of slot 70.
As best seen in FIGS. 4, 6 and 11, the inner surface 40 is formed integrally with sidewall 100 which forms the outer periphery of carrying case 22. Slots 60 and 70 are molded in inner surface 40 and narrow slots 63 and 65 are formed on opposite sides of slot 60 to permit conductive rails 62 and 64 to be positioned and held therein. Likewise, narrow slots 73 and 75 are formed on opposite sides of slot 70 to permit contact rails 72 and 74 to be positioned respectively therein and locked thereto. As best depicted in FIG. 11, it is seen that contact rails 62, 64, 72 and 74 are staked in their respective narrow slots at a plurality of staking points 80. This prevents the contact rails from becoming dislodged from the respective slots in which they are positioned. It is noted that with respect to the foregoing description, first case section 24 is constructed similarly to second case section 26. In FIG. 6, the inner surface is designated at 50 and the sidewall is designated at 102. It is also noted that although two lanes are shown, the invention is not limited to this number of lanes.
In manufacturing the set, the two case sections are first molded from a plastic material leaving the underside 110 of inner surface 40 exposed from behind. The rails are then inserted in their appropriate slots and are then staked. As best depicted in FIG. 11, an electrical coupling is made between the four tracks and a coupling socket 112 through wire junctions 114 and 116. Once again, second case section 26 similarly includes a socket 120 which is coupled through appropriate wire junctions to the contact rails thereon. A plug 125 is coupled intermediate socket 112 and socket 120 to close the loop of electrical contact so that each rail forms a continuous electrical path. In folded condition as depicted in FIG. 1, plug 125 is removed and stored in one of a plurality of depressions 130a through 130e formed in second case section 26. These depressions can also be utilized to store the toy vehicles. When the case is folded open as depicted in FIG. 3, plug 125 is then interconnected between socket 112 and socket 120 to provide the appropriate electrical coupling.
First case section 24 also includes first controller socket 130 and second controller socket 132 which are appropriately coupled to the respective rails through wire 134 and 136 as best depicted in FIG. 11.
An additional advantage of the present invention is that first and second case sections 24 and 26 are releaseably pivotably coupled together so that the sections can be uncoupled when desired. In this regard, first case section 24 includes first and second posts 150 and 152 at opposite edges thereof which releaseably mate, respectively in U-shaped projections 154 and 156 as best depicted in FIG. 3. FIG. 5 depicts that U-shaped projection 154 includes a bulge 158 on the internal surface thereof to provide a snap-locking effect. U-shaped member 156 can provide a similar snap-locking effect. These hinges permit the case to be pivoted between opened and closed position, while also permitting the case section to be separated.
One major advantage of permitting separation of the cases is to permit additional track section such as track section 200 depicted in FIG. 12 to be coupled intermediate the two case halves. In fact, a plurality of such additional track sections can be coupled intermediate to provide a larger layout and enhanced play value. Each additional track section will include appropriate hinge members 202a through 202d to permit appropriate mechanical coupling, and electrical coupling sockets 206 and 208 to permit electrical coupling between the respective track sections using additional plugs 125. The only requirement is that the track slots and rails line up from edge to edge so that toy vehicles riding thereon can be provided with a continuous path.
Reference is now made to FIGS. 9 and 10 to describe the manner in which a toy vehicle 300 rides on the track. The toy vehicle includes a downwardly projecting pin 302 which rides in slot 70 to guide vehicle 300 along the track. First and second contact shoes 310 and 312 respectively contact rail 74 and rail 72. Voltage applied between rails 72 and 74 are likewise applied between contact shoes 310 and 312 and ultimately supplied to a motor 320 depicted in phantom in FIG. 9. Motor 320 is coupled through a gear train generally indicated at 325 to drive the wheels of the vehicle. As best depicted in FIG. 9, it is seen that contact shoe 310 is biased downwardly against rail 74 by a spring 330. Contact shoe 310 is bent and configured as depicted in FIG. 9 and contacts a second conductive leaf 350 which is coupled to motor 320.
Referring now to FIGS. 7 and 8, details of a particular controller generally indicated at 400 which may be used in conjunction with the toy car racing set of the present invention will be described. Controller 400 is formed in a plastic case 402 and 402a pivotally coupled together and includes a spring biased button 404 through a spring 406. Also coupled to switch button 404 is a specially configured contact strip 410. Controller 402 is adapted to house two AA batteries 410a and 410b. A first contact 420 is coupled to the negative side of first battery 410a. A second contact 422 is coupled to the positive end of second battery 410b. A third contact 424 is coupled to the negative side of battery 410b. Finally, a fourth terminal 426 is coupled to the positive terminal of battery 410a.
Projections 422a, 424a and 426a extend from terminals 422, 424 and 426 respectively. When spring button 404 is depressed and contact strip 410 is moved in the direction of arrow A, either one battery or both batteries together will be used to provide power. In this way, the controller can be used to simulate a conventional rheostat by adjusting the power supply to the track. Controller 400 also includes a battery door 700.
Wires 450 extend from controller 400 and are plugged into controller socket 130 or 132. A second controller 401 is provided for plugging in the other of controller sockets 130 and 132. Each of the controllers will control one lane of the track so that racing between two participants can be had. Storage slots are also provided in the case for storing the controllers. It is noted that other types of controllers including those with a rheostat may be used in the present invention. Moreover, the batteries may be housed in the case itself.
As depicted in FIGS. 1, 4 and 6, after the molding of the two case halves and the insertion of the various metal components, backplates 500 are slid into place to form the outer surface of the case. These panels are held in place by a plurality of lips 525. In this fashion, the entire case except for the outer back panels can be molded integrally to reduce and simplify manufacturing.
Each lane on the track may include a lap counter as shown at 800 in FIG. 3 to further enhance the play value of the system.
The present invention as described in detail above provides a toy vehicle racing set which is readily portable through the provision of providing the track built in a portable case with handles. The case is easy to manufacture and the play value of the toy racing set is substantially enhanced by permitting the case halves to separate with additional sections being added.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. | A portable toy vehicle racing set for use with at least one toy vehicle having a motor includes a case having a first section with inner and outer surfaces and a second section with inner and outer surfaces. The case sections are pivotally coupled together to permit movement between opened and closed positions. In the closed position, the set simulates a carrying case. In opened condition, a flat track surface is presented. The first and second sections of the case include predetermined track layouts which provide a closed loop track. The closed loop track defines at least one lane in which the toy vehicle can ride with the at least one lane including contact rails for supplying power to the toy vehicle motor. | 8 |
This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/DE02/02877 which has an International filing date of Aug. 5, 2002, which designated the United States of America and which claims priority on German Patent Application number DE 101 40 331.3 filed Aug. 16, 2001, the entire contents of which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
The invention generally relates to an illuminated sign for traffic control, in particular for road traffic. It further generally relates to a method for functional monitoring of such a sign.
BACKGROUND OF THE INVENTION
Signs of widely differing types and importance are generally used for controlling traffic, in order to assist the smooth handling of the traffic. This applies to marine navigation, to aircraft, for example to airports, as well as to all rail traffic, but in particular to road traffic.
Owing to the continuously rising amount of traffic, ever more traffic signs and illuminated signs are used for controlling traffic within cities and for controlling long-distance traffic. An increasing proportion of these signs are produced by light sources. Typical examples of this are the changing illuminated signs for light signaling systems at roadway crossings and the changing traffic signs at so-called freeway intersections.
At the moment, incandescent lamps are primarily used as the light sources for illuminated signs such as these. Incandescent lamps can fail by a short or discontinuity, thus resulting in a sign to be produced by them becoming distorted, with inadequate light intensity or not being displayed at all.
In order to prevent an incorrectly displayed illuminated sign from confusing those in the traffic, it must be switched off immediately in order to avoid a risk of accidents. In order to make it possible to check the availability of a safety-relevant sign, for example a red traffic light, a speed limit or a warning display, even when it is switched off, the monitoring must take place all the time. Thus, the monitoring must take place even when the corresponding sign is not active, that is to say when it is not actually illuminated.
Functional monitoring of the incandescent lamps that produce a sign can be carried out by passing a current through their filaments. The inertia of a filament refers to the fact that the serviceability of the incandescent lamp can be tested by passing a current through the filament for a short time, for example for 1 ms, without any light emerging.
The article “On-board multiplexing system checks car's lights automatically” on pages 68 and 70 of Electronics International may be cited as a reference for a cold lamp test such as this for automatically checking a car lighting system. In this case, commands to activate the lamps are passed via a microprocessor, the signals of the lamps and sensors are monitored, and the driver is informed of any malfunction via a display on the dashboard. A power transistor connects the lighting system to the car battery. A high-impedance voltage divider is connected in parallel with this, and its center potential is used as a criterion for checking a lamp state.
During operation, the microprocessor checks the value of the center potential of the voltage divider every 10 ms. When a light is switched on, the potential is 12 V and when it is off, the potential is 0 V. In the event of a short in the lamp circuit, the potential is, however, 0 V in both cases.
In order to obtain a positive indication for all possible faults and light operating modes, the test must be extended in order also to include the OFF mode when the light is switched on the ON mode when the light is switched off. A switched-on lamp is switched off for about 100 ms once every second by the system; when it is off, the system switches it on periodically for 100 ms every 40 seconds. The tests starts when the engine is started, and ends 100 s after the engine is stopped. This extended operation ensures that lamp failures are detected even during the period when the filament is cooling down.
Incandescent lamps are now increasingly being replaced by light-emitting diodes, which are also referred to in the following text for short as LEDs. This is being done since, as a low-maintenance and high-availability light source for optical signs, LEDs have many advantages for economic operation of light signaling systems.
One problem is that signs which can be produced by LEDs have until now been capable of being monitored only when they are in the switched-on state. It has therefore not been possible to use LED technology for safety-relevant signs, whose serviceability must also be monitored when they are switched off.
Owing to the effectively inertia-free conversion of current to light in LED light sources, a functional test analogous to the so-called cold lamp test was not feasible without production of disturbing, and thus unacceptable, light flashes. In complete darkness, when an LED is operated at its rated current, even pulses with a length of more than about 0.3 μs and with a continuous current of more than about 5 μA are noticeable in a disturbing manner, largely independently of the repetition rate. Signs with functional monitoring which produce sufficiently short and weak current pulses and can reliably monitor them have not until now been feasible at an acceptable complexity level.
SUMMARY OF THE INVENTION
An embodiment of the invention is thus based on an object of providing an illuminated sign as well as a method for functional monitoring of a sign, such that the serviceability of the sign can be monitored both when it is switched on and when it is switched off, with an acceptable technical complexity level.
One part of the object according to an embodiment of the invention is achieved by an illuminated sign. By limiting the current through the light-emitting diodes that is built up after the light source has been switched on, on the basis of the time duration or level, the light emission which occurs directly from the LEDs can be restricted such that it is no longer perceptible for a viewer, even in darkness. This avoids light flashes that would disturb those in the traffic. The rise in the current through the light-emitting diodes is used as the serviceability criterion.
In one preferred refinement of an embodiment of the invention, the monitoring device for the illuminated sign has a switching device for switching off the current flow, once it has been switched on, when the current level reaches a predetermined threshold value. The electrical current flowing through the light-emitting diodes is in this case limited by presetting a maximum threshold value at which the LED current level once it is switched off has been built up. Parts of the existing current monitoring device from the incandescent lamp technology can advantageously be used for the circuitry implementation of this form of current regulation, thus minimizing the circuit cost.
In one advantageous embodiment of the invention, the switching devices are in the form of a digital logic circuit with a memory element. The LED current limiting can therefore be achieved, for example, by using a D-flipflop as the memory element, and by means of further standard components from semiconductor circuit technology.
In one preferred embodiment of the invention, the monitoring device is also designed to measure the voltage which is dropped across light-emitting diodes when current is flowing through them. This separate additional monitoring of the voltage makes it possible to detect a failed light-emitting diode despite the LED current flow, for example in the event of a short. This improves the reliability of the functional testing of an illuminated sign according to an embodiment of the invention.
In other advantageous embodiments, the light sources are arranged as a chain of series-connected light-emitting diodes or as a cluster of light-emitting diodes which are connected to one another. This is advantageously used in an embodiment of illuminated signs with symbols in the form of lines, or flat structures.
Illuminated signs according to an embodiment of the invention and with functional monitoring can preferably be used for traffic signs, in particular for those signs with the option of alternately displaying different signs, or for light signaling systems, that is to say for the generally known traffic lights.
Another object element is achieved by a method of an embodiment of the invention. Since the current flow through the light-emitting diodes is first of all switched on, a current monitoring signal which represents the current level through the light-emitting diodes is generated and, upon reaching a predetermined threshold value for the current monitoring signal, the current flow is switched off again, the light sources in the illuminated sign, which are in the form of light-emitting diodes, have a limited amount of current flowing through them during functional monitoring, such that the only light which is emitted is no longer perceptible by a viewer.
In one preferred embodiment of the method according to the invention, a voltage monitoring signal which represents the voltage that is dropped across the light-emitting diodes through which a current is flowing is also generated. The voltage monitoring signal is used as an additional criterion for assessing the serviceability of a light-emitting diode, in order to make it possible to exclude a short when there is a positive LED current flow.
In one advantageous refinement of the method according to an embodiment of the invention, the current flows when the light-emitting diodes are in an inactive state, or periodically in an inactive phase. This allows the functional monitoring to be carried out not only when the illuminated sign is not in operation—even for a lengthy time period of several months—but also during operation, by switching off the regular LED current flow periodically for a short phase, in which the even shorter test current flow then takes place.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages, features and details of the invention will become evident from the description of illustrated embodiments given hereinbelow and the accompanying drawings, which are given by way of illustration only and thus are not limitative of the present invention, wherein:
FIG. 1 shows, schematically, a circuit for current regulation in an illuminated sign according to an embodiment of the invention,
FIG. 2 shows, schematically, the time periods of an LED drive signal, and
FIG. 3 shows, schematically, the logic circuit as switching means for the monitoring device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An illuminated sign according to an embodiment of the invention, for example a changing traffic sign for displaying different traffic signs alternately, is produced, for example, in an outdoor system which is in the form of a display gantry above roadways. The outdoor system has a mains connection for supplying voltage to the LED chains. For this purpose, a commercially available industrial switched-mode power supply, for a DC voltage of 48 V and having an input rating of 100 W, is used. This is connected via a CAN bus to a roadway section station which includes a modem as well as a control and a master module.
By way of example, 32 LED chains, subdivided into four groups of eight each, can be driven via a common drive assembly. The drive assembly contains a digital part and an analog part. The digital part has modules for initialization, assembly identification, read/write logic, a test register, the enabling logic for the normal mode and the test mode, the LED current setting as well as the current and voltage monitoring, while the 32 LED current regulators form the analog part. Up to 8 such drive assemblies can be connected to a common control unit, and they are controlled via a processor module which runs a stored program in order to drive and monitor the LED chains.
In a changing traffic sign for use on federal freeways, a light-emitting diode chain includes, for example, 11 to 19 series-connected light-emitting diodes LED. Each LED chain is driven, as is shown in FIG. 1 , by a transistor Q 3 which is connected as a current source. The reference variable for the current level is the output voltage from a digital/analog converter DAC, which is connected to the base of the transistor Q 3 via a transistor Q 4 .
When a positive drive signal is present in the LED switch-on signal LE, a collector current which corresponds approximately to the quotient of the voltage from the converter DAC and the resistance R 5 is produced after a circuitry-dependent delay time of approximately 1 μs in the transistor Q 3 . This constant current flows, minus a small parallel current flowing through the resistances R 2 and R 3 , as the operating current through the LED chain. The chain current itself produces a voltage drop in a resistance R 1 which is connected upstream of the LED chain and, on reaching the collector/emitter threshold of a transistor Q 1 , switches this transistor on and generates the current monitoring signal IO.
A transistor Q 2 is also driven via resistances R 2 and R 3 when the voltage drop across the LED chain reaches a value which is set by the voltage divider ratio of R 2 to R 3 , and a voltage monitoring signal UO is thus generated via the transistor Q 2 . Resistances R 6 and R 7 as well as R 8 and R 9 are in this case used for signal conversion to TTL levels.
The monitoring signals IO and UO are stored in the drive assembly and are signaled back to the control unit, where they are processed. The current monitoring is carried out using a standard, fixed threshold for all of the chains: the current sensor output indicates “OFF” when the chain current is less than 4 mA, and indicates “ON” when it is greater than 7 mA. The voltage monitoring for all of the LED chains is likewise carried out using a standard, fixed threshold.
In the test mode, all of the LED chains are checked cyclically, and current faults are found within 10 s. In the normal and test modes, an LED chain is deduced to have failed when the preset nominal value for the voltage indicates “ON” and the measured actual sensor value for the current level indicates “OFF” at the same time. A current fault does not lead to switching off unless a sign which is required at that time can no longer be identified as being able to be displayed. A sign is regarded as no longer capable of being displayed when the number of faulty LED chains exceeds the supplied limit.
The LED drive signal when the light source is active is built up periodically as shown in FIG. 2 with a period duration T period of, for example, 10.0 ms. A period starts at the starting point to and is subdivided into an illuminated time T Light , that is to say the maximum LED current flow time of, for example 9.0 ms, and a test time T Pause of, for example, 1.0 ms. The illuminated time T Light is composed of the actual current-flow time T current , which is approximately 0.1 to 1.0 times the illuminated time T Light for dimming as a function of the environmental brightness. The test pulse T Test , which has a maximum duration of 0.3 μs, is produced for functional monitoring of the LED chain during the test time T Pause .
In this case, the pulse length ensures that the LED current flow does not result in any disturbing light emission to any of those involved in the traffic. The test pulse T Test may, of course, be produced not only in a periodic interruption in the illuminated time T Light , but also in a longer-lasting inactive state of the light source, in order that the availability of the illuminated sign can be checked at any time for a safety-relevant application.
The maximum LED current flow time which is required for the purpose of avoiding visible light flashes is achieved by adding a logic circuit, as shown in FIG. 3 , to the current regulator circuit—as described in FIG. 1 . The LED switch-on signal LE is controlled via the output OR_out of an OR gate OR, for example of the 74HC32 type.
In the case of a regular LED current flow, the input OR_in 1 is equal to 1, and the output OR_out is thus likewise 1. In the test mode, the LED input OR_in 1 is equal to 0, and the test input is equal to 1. This is applied to one input XOR_in 2 of an EXOR gate XOR, for example of the 74HC86 type. The state at the other input XOR_in 1 is initially 0, so that the output XOR out assumes the value 1 owing to the different input states. The output XOR_out is connected to the second input OR_in 2 of the OR gate OR, which thus likewise assumes the value 1 .
In consequence, OR_out is equal to 1, so that the LED test current flow is switched on. The input XOR_in 1 is connected to the output FF_Q_out of a clock-state-controlled D flipflop FF, for example of the 74HC74 type, to whose D input FF_Reset the signal of the test input is applied, that is to say the value 1 .
The flipflop FF does not react to the initial state until the clock variable at the C input FF_Clock assumes the value 1 . This is the case when the current monitoring IO produces the value 1 , that is to say the LED current level has exceeded the predetermined threshold value. The Q output FF_Q_out of the flipflop FF will now assume the value 1 , and, in a corresponding manner, {overscore (Q)} will assume the value 0 . On the one hand, this results in the input state at XOR_in 1 changing from 0 to 1, which leads to an output state XOR_out of 0; via the OR gate, this switches off the LED current flow. On the other hand, FF_Q_out equal to 1 signals that the LED chain is serviceable.
Exemplary embodiments being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | An illuminated sign is for traffic control, in particular for road traffic, and includes light sources for generation of the sign and a monitoring device for functional monitoring of the light source. The light sources are embodied as light diodes and the monitoring device is embodied as a device for the limited current loading of the light diodes. The functional monitoring of said sign can be achieved with reasonable technical requirements in both the deactivated and activated state thereof. | 7 |
FIELD OF THE INVENTION
This invention relates generally to a novel process for producing allyl alcohol and, more specifically, to a process which utilizes a molten nitrate salt catalyst.
BACKGROUND OF THE INVENTION
Allyl alcohol is a widely used reactant in the production of glycerol as well as other organic chemicals (e.g., 1,4-butanediol). Conventional processes for the manufacture of allyl alcohol typically involve one of the following: (a) the alkaline hydrolysis of allyl chloride, (b) the oxidation of propylene to acrolein, followed by the reaction of the acrolein with a secondary alcohol to form allyl alcohol and a ketone, or (c) isomerization of propylene oxide using a lithium phosphate catalyst. None of these methods offer a direct one-step synthesis of allyl alcohol.
New methods of producing allyl alcohol that provide advantageous selectivity in a simple, inexpensive production process would be highly desirable.
SUMMARY OF THE INVENTION
In one aspect, the present invention relates to a process for producing allyl alcohol by reacting propylene with an oxygen-containing gas in the presence of at least one molten nitrate salt catalyst. The process preferably is effected under reaction conditions which provide a molar selectivity to allyl alcohol of at least about 40 percent based upon the propylene reactant.
In another aspect, the present invention relates to a process for producing allyl alcohol from propylene, or mixtures of propylene and propane, which comprises bubbling an oxygen-containing gas and said propylene or mixture through a bath of at least one molten nitrate salt catalyst under reaction conditions which include a temperature of between about 135° C. and about 600° C. (preferably between about 135° C. and about 350° C.) and a superatmospheric pressure not exceeding 100 atmospheres (preferably up to about 40 atmospheres).
In still another aspect, the present invention relates to a process for producing allyl alcohol by reacting propylene with an oxygen-containing gas in the presence of a catalyst, said catalyst consisting essentially of a mixture of sodium nitrate and potassium nitrate containing between about 20 weight percent and about 80 weight percent of sodium nitrate based upon the total amount of sodium nitrate and potassium nitrate in said mixture, under reaction conditions which include a reaction temperature of between about 275° C. and about 350° C. and a reaction pressure of between about 100 psig and about 400 psig.
In yet another aspect, the present invention relates to a process for producing allyl alcohol by reacting propylene with an oxygen-containing gas in the presence of a catalyst, said catalyst consisting essentially of a mixture of sodium nitrate, potassium nitrate and lithium nitrate, containing between about 10 weight percent and about 30 weight percent of lithium nitrate and between about 15 weight percent and about 75 weight percent of sodium nitrate based upon the total amount of said mixture, under reaction conditions which include a reaction temperature of between about 200° C. and about 350° C. and a reaction pressure of between about 100 psig and about 400 psig.
DETAILED DESCRIPTION OF THE INVENTION
It has now been found in accordance with the present invention that allyl alcohol is produced by the reaction of propylene with an oxygen-containing gas in the presence of at least one molten nitrate salt. Further, it has now been surprisingly discovered that high molar selectivities to allyl alcohol of at least about 40 percent are provided by suitable selection of reaction conditions.
Several factors will affect the reactant conversion to allyl alcohol and the selectivity of allyl alcohol production vis-a-vis by-product production in accordance with the process of the present invention. These factors include, for example: the contact time of the molten salt with the oxygen-containing gas, the temperature of the reactor product gases, the molten salt temperature, the molten salt composition, the feed gas temperature, the feed gas composition, and the feed gas pressure.
The oxygen-containing gas useful as a reactant in the present invention can be any such gas. Typically, air is employed as the oxygen-containing gas based upon its ready availability. However, other oxygen-containing gases such as pure oxygen may be employed, if desired, and the use of oxygen is expected to be preferred in a commercial setting.
The propylene reactant useful in the present invention is suitably propylene itself or a mixture of propylene and propane, and the choice is typically based upon commercial availability.
The propylene is preferably preheated to prevent condensation in the line delivering this gas to the reactor. Alternatively, both the oxygen-containing gas and the propylene (collectively referred to herein as "the feed gases") can be preheated to prevent condensation at any point in the feed gas system. However, in the absence of preheat, the molten nitrate salt will rapidly heat the feed gases up to reaction temperature. If the feed gas is preheated, it preferably is maintained at at least about 100° C. in the feed gas line(s).
The molten nitrate salt(s) is generally maintained at a temperature sufficient to keep the salt(s) in a molten condition. Generally, the temperature is maintained between about 135° C. (275° F.) and about 600° C. (1,000° F.) during the reaction in accordance with the present invention. The specific temperature selected is based upon the melting point of the particular molten nitrate salt chosen.
The molten salt(s), in addition to functioning as a catalyst, also serve as a temperature regulator. More specifically, the molten nitrate salt(s) have a high heat absorption capacity, enabling them to absorb large quantities of heat during the exothermic oxidation reaction whil maintaining an essentially constant reaction temperature and thereby preventing a runaway reaction. The absorbed heat of reaction from this exothermic oxidation may be employed in the process of the present invention to help maintain the molten salt in a molten state and/or to heat the gaseous reactants to reaction temperature. In the process of the present invention, the molten salt(s) is employed in an amount sufficient to maintain isothermal reaction conditions by absorbing the reaction exotherm. Typically, the molten salt(s) is employed in an amount on a weight basis of between about 5 times and about 100 times (preferably between about 5 times and about 50 times) the total weight of the reactants employed.
The nitrate salt used may be any one of the alkali or alkaline earth nitrates such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, or barium or mixtures thereof. In addition, the nitrate salts can be used in mixtures with other salts such as chlorides, bromides, carbonates, sulfates, and phosphates. Generally, the content of the other salt(s), when present, should be restricted to less than 60 percent by weight based upon the weight of the total melt and in most cases their contents should not exceed about 25 percent of the total melt.
In a preferred embodiment of the present invention, a mixture of potassium and sodium molten nitrate salts is employed comprising between about 20 and about 80 weight percent of sodium nitrate, preferably between about 45 and about 65 weight percent of sodium nitrate based upon the total amount of sodium nitrate and potassium nitrate in the molten salt mixture. When using this mixture, it has been found in accordance with the present invention that a product molar selectivity to allyl alcohol of at least about 40 percent based upon the propylene reactant is achievable by employing a temperature of between about 325° C. and about 350° C. and a pressure of between about 250 psig and about 350 psig (most preferably about 300 psig). When using higher elevated pressures of up to 600 psig or higher, the temperature is suitably adjusted downward to provide the desired high molar selectivity of allyl alcohol product.
Mixtures of molten lithium and potassium nitrate can be suitably employed at a temperature as low as about 280° F., and hence, this temperature may be employed when using lithium nitrate mixtures. In the selection of a suitable molten nitrate salt bath temperature it is important to choose a temperature below the thermal decomposition temperature for the particular molten nitrate salt chosen. In addition, it is important to maintain a sufficient isotherm across the molten nitrate salt bath so as to avoid crust formation of the nitrate salt in the bath. Such a crust formation in the nitrate salt bath can cause localized overheating of gases trapped by the crust in the bath and an associated "runaway" oxidation reaction due to overheating of the gases in the bath. In order to maintain a bath isotherm, constant stirring of the molten nitrate salt bath is preferred. Alternatively, the molten salt can be circulated by conventional means, such as the use of internal draft tubes or external pumping loops.
The ratio of propylene to oxygen in the oxygen-containing gas in the reactor can vary over a wide range. However, in accordance with the present invention, it has now been found that enhanced selectivity of the desired allyl alcohol product is achieved by maintaining a relatively low amount of oxygen relative to the amount of propylene fed into the reactor. For example, when reacting propylene with oxygen in a molten potassium nitrate salt column at atmospheric pressure, a ratio of between about 1 and about 20 volume percent of oxygen, (e.g., about 5 volume percent oxygen to about 95 volume percent propylene), suitably provides an enhanced selectivity of allyl alcohol. When using air as the oxygen-containing gas, it is preferably employed in an amount of between about 5 and about 75 volume percent based upon the total amount of air plus propylene employed in the reaction.
Another consideration in the selection of the amount of propylene to use as a feed is its high partial pressure which in high concentrations can cause thermal cracking of propylene. Therefore, when conducting the oxidation reaction at an elevated pressure, viz 300 psig, it is generally preferred to "cut" the amount of propylene in the illustrative example to 75 volume percent and utilize an inert blanket ("diluent") gas, such as nitrogen, to provide the remaining 20 volume percent of feed gas. Preferably, the amount of propylene in the feed gas containing oxygen and an inert blanket gas is less than about 50 volume percent, more preferably between about 20 volume percent about about 35 volume percent of propylene based on the total amount of feed gas. Alternatively, the diluent gas may be comprised of mixtures of oxidation by-product gases such as acetaldehyde, methane, and carbon dioxide, generally readily obtainable from the allyl alcohol purification operations downstream of the molten salt reactor.
In the selection of the ratio of the volume of oxygen-containing gas relative to the volume of propylene employed in the reaction mixture, the range of ratios which might pose a flammability hazard should be avoided, as is well known. For example, when utilizing an air/propylene reactant mixture at atmospheric pressure, the range of below 12 volume percent of propylene based upon total air plus propylene should be avoided.
The preferred method of contacting the gaseous reactants in the presence of the molten nitrate salt is by bubbling the reactants through a bath of the molten salt, preferably in a deep bed autoclave "bubble" reactor. If the gaseous reactants are bubbled into the bottom of the bath or column containing the molten nitrate salt, the contact time of the reactants with the molten salt catalyst is equal to the "rise time" of the reactants through the bath or column. Thus, the contact time can be increased by increasing the length of the molten nitrate salt bath or column. An alternate method of contacting the gaseous reactants in the presence of the molten salt would be to pass the gaseous reactants through a reaction countercurrently to a spray or mist of the molten salt. This method provides for enhanced surface area contact of the reactants with the molten salt. Still another method of contacting the gaseous reactants with molten salt would be to inject the reactants into a circulating stream of molten salt, wherein the kinetic energy of both streams is utilized to provide intimate mixing through the application of nozzles, mixers, and other conventional equipment. This latter method is expected to be preferred in a commercial setting. These methods are only illustrative of types of reaction systems which may be employed in the practice of this disclosure. Other conventional methods of gas-liquid contact in reaction systems may also be employed.
The propylene feed gas can be passed into the molten nitrate salt-containing reactor using a separate stream (e.g. feed tube) from the stream delivering the oxygen-containing gas to the reactor. Alternatively, the reactant gases can be fed into the reactor together in a single stream. In a preferred embodiment of the present invention, two co-axially mounted feed gas tubes are employed. The co-axial mounting of the feed gas tubes has been found to reduce or minimize the back-up of molten salt into an unpressurized feed tube if pressure is temporarily lost in either (but not both) feed tube. Mixing of the gaseous reactants prior to, or at the point of, the gas(es) inlet into the reactor is desired in order to facilitate the oxidation reaction. Mixing is suitably accomplished using an impingement mixer or sparger tube.
The feed gas is preferably bubbled into the molten nitrate salt-containing reactor using a sparger. If used, the sparger is preferably positioned in the molten nitrate salt to a sparger exit port depth of between about 2 and about 1000 centimeters, preferably between about 10 and about 200 centimeters, depending upon the size of the reactor utilized and the overall depth of the molten salt in the reactor. Alternatively, the gas can be fed directly into the bottom of the reactor by a feed tube.
The process can be run in a batchwise or continuous operation, the latter being preferred. The order of introduction of the reactants is determined by the operator based on what is most safe and practical under prevalent conditions. Generally, the desirability of avoiding flammable gas mixtures throughout the reaction and subsequent product separation systems will dictate the desired procedures.
The process can be carried out by feeding a mixture of propylene, inert gas, and oxygen into a reaction vessel containing molten nitrate salt. The reaction vessel can be glass, glass-lined metal, or made of titanium. For example, a glass-lined stainless steel autoclave can be used, although, even better from a commercial point of view, is an unlined type 316 stainless steel autoclave (as defined by the American Iron and Steel Institute). A tubular reactor made of similar materials can also be used together with multi-point injection to maintain a particular ratio of reactants. Other specialized materials may be economically preferred to minimize corrosion and contamination of the molten salt and products, or to extend the useful life of the reaction system.
Some form of agitation of the molten salt(s)/feed gas mixture is preferred to avoid a static system and insure the homogeneity of the molten salt, agitation helps prevent crust formation of the salt(s) at the head gas/salt interface in the reactor. However, excessive backmixing and reactor holdup time leads to undesirable overoxidation. The proper amount of mixing can be accomplished by using a mechanically stirred autoclave, a multi-point injection system, or a continuous process, e.g., with a loop reactor wherein the reactants are force circulated through the system. Sparging alone can also be used and is sufficient in certain cases. In the subject process, it is found that increased rates of reaction are obtained by good gas-liquid contact provided by agitation of the molten salt/gas mixture without excessive backmixing of the reactant gases.
The process of the present invention is suitably carried out at atmospheric, subatmospheric or superatmospheric pressure. Preferably, the process is effected at superatmospheric pressures not exceeding 100 atmospheres, preferably between about 250 psig and about 600 psig, more preferably between about 100 psig and about 400 psig. The process is suitably effected at a temperature of between about 135° C. and about 600° C., preferably between about 135° C. and about 350° C.
It is to be understood that by-products are also produced during the reaction. For example, some dehydrogenation of the feed is also effected, particularly at higher temperatures within the hereinabove noted temperature range, and therefore, the reaction conditions are generally controlled to minimize such production. The separation of the resulting by-products in order to recover the desired product may be effected by a wide variety of well-known procedures such as: absorption in water followed by fractional distillation, absorption, and condensation.
The following examples are intended to illustrate, but in not way limit the scope of, the present invention.
EXAMPLE 1
Preparation of Allyl Alcohol in High Molar Selectivity
A four liter stainless steel autoclave reactor rated for pressures up to 5,000 psi at 250° C. was charged with 3,900 g of sodium nitrate and 2,600 g of potassium nitrate. This salt mixture was melted and brought up to 334° C. by use of an external resistance heater. Propylene at the rate of 1400 cc/min (STP) was sparged into the melt through the inner tube of a set of co-axial feed tubes. An oxygen and nitrogen mixture consisting of 130 cc/min of oxygen and 2480 cc/min of nitrogen was sparged in through the outer tube. The two feed gas streams mixed inside the porous metal sparger fitted to the end of the co-axial feed tubes and immediately entered the molten salt. The depth of the sparger element into the salt was 52 cm. The gases were brought up to 300 psig pressure using a backpressure regulator. The gases flowed into and out of the reactor in a continuous manner such that the contact time with the molten salt amounted to only a few seconds. The gases exiting the molten salt were quenched to a temperature below 200° C. by a cooling coil mounted in the head space of the reactor. The gas exiting the reactor passed through an ice water trap for easily condensible substances and through a gas sample cylinder ("sample bomb") in line after the trap. After 30 minutes of operation, the reactor off gases were sampled, the reaction was stopped by stopping the flow of the reactant feed gases, and the trap contents were collected. The gas sample and the trap sample were analyzed by gas chromatography methods. The propylene per pass conversion was determined to be 2 percent, the selectivity to allyl alcohol was found to be 48 percent based upon the propylene reactant, and the selectivity to propylene oxide was found to be 5.5 percent.
EXAMPLE 2
Preparation of Allyl Alcohol in Lower Molar Selectivity
The oxidation of propylene was carried out in the exact same manner as in EXAMPLE 1 except that the molten salt temperature was raised to 360° C. instead of 334° C. in EXAMPLE 1 above. The propylene conversion was found to be 5.1 percent, the selectivity to allyl alcohol was found to be 3.7 percent and the selectivity to propylene oxide was found to be 42.3 percent. The major other products formed were acetaldehyde at 22 percent selectivity and carbon dioxide at 18 percent selectivity.
EXAMPLE 3
Preparation of Allyl Alcohol in Lower Molar Selectivity
The oxidation of propylene was conducted in the same manner as in EXAMPLE 1 at 300 psig total pressure with a total gas flow of about 4000 cc/min, but with the exception that the propylene flow was increased to about 2000 cc/min, the oxygen flow was increased to 205 cc/min, and the nitrogen flow was decreased to 1790 cc/min. The salt temperature was also lowered to 310° C. The results from this experiment showed a propylene per pass conversion of 0.5 percent, a selectivity to allyl alcohol of 15 percent, and a selectivity to propylene oxide of 13 percent.
EXAMPLE 4
Preparation of Allyl Alcohol in Lower Molar Selectivity
When the same conditions as in EXAMPLE 3 were tried except at 355° C., the propylene per pass conversion was 4.1 percent, the selectivity to allyl alcohol was 3.3 percent, and the selectivity to propylene oxide was 43.5 percent.
EXAMPLE 3 at 310° C. and EXAMPLE 4 at 355° C. illustrate processes which provide allyl alcohol selectivities of 15 and 4 percent, respectively. This illustrates the effect of temperature upon the allyl alcohol selectivity. Under otherwise similar conditions, the selectivity to allyl alcohol is generally higher at lower temperatures or has an optimum temperature for allyl alcohol production that is much lower than the optimum temperature for production of propylene oxide. | A novel process for producing allyl alcohol and, more specifically, to a process which utilizes a molten nitrate salt catalyst. | 2 |
This is a divisional of application Ser. No. 07/984,272, filed Dec. 1, 1992, now U.S. Pat. No. 5,376,542, which is a continuation of application Ser. No. 07/678,699, filed Apr. 1, 1991 now abandoned.
BACKGROUND OF THE INVENTION
A great deal is known about human platelet cells. General publications describing techniques, materials, and methods for the storage of platelets are described by Murphy et al. in "Improved Storage of Platelets for Transfusion in a New Container", Blood 60(1):194-200 (1982); by Murphy in "The Preparation and Storage of Platelets for Transfusion", Mammon, Barnhart, Lusher, and Walsh, PJD Publications, Ltd., Westbury, N.Y. (1980); by Murphy in "Platelet Transfusion", Progress in Hemostasis and Thrombosis, Vol. III, Ed. by T. Spaet, Grune and Stratton, Inc. (1976); by Murphy et al. in "Platelet Storage at 22° C.: Role of Gas Transport Across Plastic Containers in Maintenance of Viability", Blood 46(2):209-218 (1975); by Kilkson, Holme, and Murphy in "Platelet Metabolism During Storage of Platelet Concentrates at 22° C.", Blood 64(2):406-414 (1984); by Murphy in "Platelet Storage for Transfusion", Seminars in Hematology 22(3): 165-177 (1985); by Simon, Nelson, Carmen, and Murphy in "Extension of Platelet Concentrate Storage", Transfusion 23:207-212 (1983); by Cesar, Diminno, Alam, Silver, and Murphy in "Plasma Free Fatty Acid Metabolism During Storage of Platelet Concentrates for Transfusion", Transfusion 27(5):434-437 (1987), each of which publications is hereby incorporated by reference as if more fully set forth herein.
In order to maintain viability, platelets must generate new adenosine triphosphate (ATP) continuously to meet their energy needs. Two chemical pathways are generally available: glycolysis and oxidative phosphorylation. In glycolysis, one molecule of glucose is converted to two molecules of lactic acid generating two molecules of ATP. In oxidation, glucose, fatty acid or amino acid enters the citric acid cycle and is converted to CO2 and water. This pathway requires the presence of an adequate supply of oxygen. It is much more efficient than glycolysis, producing 36 molecules of ATP per molecule of glucose.
It has been recognized that platelets will meet their energy needs in a manner which is not necessarily consistent with their long term storage ex vivo in a viable condition. When given adequate oxygen, platelets produce most of their required ATP through oxidation, but continue to produce lactic acid through glycolysis instead of diverting all metabolized glucose through the oxidative pathway. Therefore, during storage of platelets in plasma, a glucose-containing medium, lactic acid concentrations have been found to rise approximately 2.5 mM per day. This leads to a gradual fall in pH, even in the presence of naturally occurring plasma buffers, principally sodium bicarbonate.
A considerable body of prior art exists concerning storage of platelets. Prior work has shown that the duration of platelet storage is limited by the continuing production of lactic acid by platelets. Although this provides energy for the platelets, the lactic acid produced acidifies the medium containing the platelets, which eventually destroys the cells. It is also known that fatty acids and amino acids may be used as substrates for oxidative metabolism of stored platelet cells.
In routine blood banking practice, platelet concentrates (PC) are prepared by drawing a unit of blood (about 450 ml) into a plastic bag containing an anticoagulant and then centrifuging the blood into three fractions: red cells, plasma, and platelets. The separated platelet fraction is then suspended in approximately 50 ml of plasma. This platelet-containing product is then stored until needed for transfusion into a patient.
A number of interrelated factors have been shown to affect platelet viability and function during storage. For example, the anticoagulant used for blood collection, the method used to prepare PC, and the type of storage container used.
The currently accepted standard practice is to store PC for five days at 22° C.; after five days, it has been shown that platelet function may be impaired. In addition to storage time, other storage conditions have been shown to affect platelet metabolism and function including initial pH, storage temperature, total platelet count, plasma volume, and agitation during storage.
One of the major problems in PC storage is regulation of pH. Virtually all units of PC show a decrease in pH from their initial value of approximately 7.0. This decrease is primarily due to the production of lactic acid by platelet glycolysis and to a lesser extent to accumulation of CO 2 from oxidative phosphorylation. As the pH falls, the platelets change shape from discs to spheres. If the pH falls below 6.0, irreversible changes in platelet morphology and physiology render them non-viable after transfusion. An important goal in platelet preservation, therefore, is to prevent this decrease in pH. Platelets must be stored in a container permeable to oxygen since glycolysis is stimulated when oxygen availability is limited.
In association with the decrease in pH, striking deceases in the total amount of ATP per platelet has been observed. It is well known that this reduction of the total ATP level is secondary to the degradation of metabolic ATP to hypoxanthine. The depletion of metabolically available ATP affects platelet function because ATP is essential for such roles in hemostasis as platelet adhesion and platelet aggregation. The ability of PC to maintain total ATP at close to normal levels has been found to be associated with platelet viability.
The composition of platelet storage media has been shown to have a direct effect on the maintenance of platelet function and viability. A number of approaches for the storage of platelets for transfusion have been described.
U.S. Pat. No. 2,786,014 (Tullis) discloses a therapeutic product for injection into humans comprising gelatin, sodium chloride, sodium acetate, carbohydrate (glucose), platelets, and water. It is taught at Col. 2, line 56-62, that the acetate anion acts as an anti-agglutinate for the platelets in this composition. The glucose is disclosed as an example of a hypertonicity-increasing agent.
U.S. Pat. No. Re. 32,874 (Rock et al.) and U.S. Pat. No. 4,447,415 (Rock et al.) disclose a medium for storing platelets in a plasma-free, balanced salt medium. Various additional additives may be added to enhance platelet stability including nutrients, reversible inhibitors of platelet activation, substances to raise cyclic adenosine monophosphate levels, and buffering agents. The disclosed nutrients are fructose, adenine, or acetyl CoA. The reversible inhibitors include indomethacin, quinacrine, or vitamin E. Prostaglandins E1, D2, or I2 are taught for raising AMP levels. The buffering agents disclosed are phosphate or amino acids such as histidine, cysteine, tyrosine, lysine or arginine.
U.S. Pat. No. 4,390,619 (Harmening-Pittiglio) discloses a method of storing and preserving shelf life of platelets for transfusion using ion-exchange resins. These resins provide a source of metabolizing ions in an amount and at a rate sufficient to maintain both pH and ATP levels suitable for transfusion.
While both acetate and phosphate have been used individually in media for storage of platelets for transfusion, the benefits of using them together in a platelet storage medium have not been appreciated previously.
SUMMARY OF THE INVENTION
The invention is concerned with a novel medium for the storage of platelets for transfusion, said medium comprising phosphate and acetate or a ketone body such as acetoacetate, beta-hydroxybutylate, or acetone or a soluble, short-chain fatty acid or other compound which can enter the tricarboxylic acid cycle in a fashion similar to acetate. The medium may also contain standard ingredients such as glucose, sodium, potassium, calcium, magnesium, chloride, citrate, and sulfate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing lactate accumulation over 7 days of storage of platelets in media C, C+P, C+AP and C+A.
FIG. 2 is a graph showing changes in pH over 7 days of storage of platelets in media C, C+P and C+AP.
FIG. 3 is a graph showing that superior pH maintenance in C+AP medium is not due simply to reduced rate of production of lactic acid by comparing media C+P and C+AP.
FIG. 4 is a graph showing the rates of oxygen consumption in paired studies in media C and C+AP on day 1 and day 7 of storage. Day 7 is also expressed as a % of day 1. Contrasting results in C+A are shown.
FIG. 5 is a graph showing the platelet count (as % of day 1 plt. count) and % discs, measures of platelet viability, after 7 days of storage in paired studies in media C and C+AP. C+A results are contrasted.
FIG. 6 is a graph showing the mean platelet volume (MPV) (as % of day 1) and dispersion, measures of platelet viability, after 7 days of storage in paired studies in media C and C+AP. C+A results are contrasted.
FIG. 7 is a graph showing ATP levels after 7 days of storage in paired studies in media C and C+AP as μm/10 11 platelets and as a % of day 1. C+A results are contrasted.
FIG. 8 is a graph showing osmotic reversal reaction (OS REV) (both % and as % of day 1) after 7 days of storage in paired studies in media C and C+AP. C+A results are contrasted.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to a medium for the storage of platelets for transfusion comprising phosphate and substrate for oxidative phosphorylation and for providing buffering upon oxidation. Useful substrates include acetate or a ketone body such as acetoacetate, beta-hydroxybutylate, or acetone or a soluble, short-chain fatty acid or other compound which can enter the tricarboxylic acid cycle in a fashion similar to acetate. Each medium component plays an essential role in maintaining platelet viability. Such acetate, ketone body or soluble, short-chain fatty acid acts as a substrate for oxidative phosphorylation and provides bicarbonate buffer upon oxidation. Phosphate inhibits AMP deaminase, which is activated upon a rise in AMP when acetate or a similar compound reacts with ATP. This is believed to be the basis for the beneficial effect of phosphate when used in combination with acetate, or an acetate-like compound.
The major problems in designing a platelet storage medium have been to include a substrate for oxidative phosphorylation and a buffer to counteract the acidifying effect of the lactic acid which platelets produce during storage. Acetate has been found to be a suitable substrate. In addition, its oxidation produces bicarbonate:
CH.sub.3 COOO+2O.sub.2 =CO.sub.2 +HCO.sub.3 +H.sub.2 O
Thus, the use of acetate serves two purposes, i.e., substrate for oxidative phosphorylation and buffer.
However, the initial activation of acetate involves:
Acetate+ATP+CoA=Acetyl-CoA+AMP+PP.sub.i.
The fall in ATP and rise in AMP may activate AMP deaminase leading to depletion of cellular adenine nucleotides which may lead to irreversible cellular damage and acceleration of lactic acid production to compensate for the decrease in ATP. It has been found that phosphate inhibits AMP deaminase, thus preventing this problem in the use of acetate in a platelet storage medium. Phosphate may also act as a buffer and/or provide substrate for resynthesis of ADP and ATP.
While both acetate and phosphate have been used previously individually, the benefits of using them in combination in a platelet storage medium was not appreciated. Platelets stored in the medium of the invention show outstanding in vitro characteristics which correlate with in vivo recovery.
EXAMPLES
Example 1
Preparation of Platelet Storage Medium
In a preferred embodiment, platelet storage medium is prepared as follows. A parent solution identified as "C+AP" is prepared by mixing the following ingredients:
______________________________________ mls______________________________________Ringers (147.5 mEq/L sodium, 4.5 mEq/L calcium, 2704.0 mEq/L potassium, 156 mEq/L chloride)Sodium Citrate (2.5%) 80Dextrose (50%) 2KCl (14.9%) 0.4MgSO.sub.4 (50%) 0.15Sodium phosphate (3 mmole/ml) 2.8Sodium acetate (2 mEq/ml) 4.5______________________________________
The resulting solution has an osmolarity of approximately 375, and a pH of approximately 6.5. Approximately 90 ml of water is then added to produce an osmolarity of approximately 300. 1N NaOH is then added to the solution to bring the pH, measured at 22° C., to 7.0 (approximately 2.5 ml).
Example 2
PC were prepared from whole blood donations in accordance with standard methods well known in the art, except that the supernatant plasma was extracted from the bag containing the platelet button as completely as possible using a Fenwal plasma extractor (Fenwal Laboratories, Deerfield, Ill.). Resulting platelet buttons were resuspended in approximately 60 ml of one of three media. Measured concentrations (mM) for each of these media were as follows:
______________________________________ MEDIA C C + P C + AP______________________________________Sodium 164 156 167Potassium 5.2 4.0 3.8Calcium 1.7 1.3 1.2Chloride 118 90 88Magnesium 0.9 0.6 0.5Phosphate 2.8 18.1 17.7Glucose 15.3 12.3 10.6pH 7.008 6.985 6.958Osmolarity 324 310 329______________________________________
C, which contains no acetate, is a satisfactory control medium but bicarbonate must be added or pH falls to an unacceptably low level. C+P contains no acetate. Each medium solution was designed to contain the same amount of citrate, i.e., the equivalent of 0.57% sodium citrate. Sodium acetate was added to C+AP to achieve the final concentration, 20 mM. For all figures, the poor results for acetate only addition (C+A) are indicated as triangles for comparison.
FIG. 1 shows lactate accumulation over 7 days of storage. The slowest lactate rise is seen with C+AP. C has an intermediate position while glycolysis is accelerated in C+P and C+A. FIG. 2 shows pH during storage. It is stable in C because of bicarbonate addition and in C+AP for which bicarbonate addition is unnecessary. However, pH falls to unacceptable levels in C +P. FIG. 3 shows that superior pH maintenance in C+AP is not due simply to reduced rate of production of lactic acid. The relationship between pH and lactate suggests that C+AP provides a buffering effect in spite of the fact that the maximum buffering capacity of acetate is at pH, 4-5.
In these studies, the mean starting PC volume was 64 ml with mean platelet count, 1.4×10 g . Thus, mean PC platelet content was 9.2×10 10 . Daily glucose fall in concentration and rise in lactate concentration were 0.67 mM and 1.28 mM, respectively. Thus, as expected, almost all of the glucose consumption can be accounted for by rise in lactate concentration. Mean bicarbonate concentrations (calculated from pH and pCO o with the Henderson-Hessalbach equation) were 3.8 and 3.2 meq/liter on days 1 and 7 respectively. Thus, in spite of the continuing accumulation of lactic acid, pH and bicarbonate levels are stable. The best explanation for this derives from the equation for acetate oxidation:
CH.sub.3 COOO+2O.sub.2 =CO.sub.2 +HCO.sub.3 +H.sub.2 O
Thus, a molecule of bicarbonate is produced for every molecule of acetate oxidized.
FIG. 4 shows that the rates of oxygen consumption for C+AP are consistently higher than for C by approximately 35% on day 1 of storage. This higher oxygen consumption persists on day 7. The oxygen consumption data translates into approximately 2.2 mmoles oxygen consumed per day per liter of PC. If all oxygen consumption were devoted to acetate oxidation, this would result in a fall in acetate concentration of approximately 1 mM per day and the generation of 1.1 mM bicarbonate per day. This essentially accounts for the buffering of the lactic acid being produced without consumption of the bicarbonate provided by plasma carryover. In the next series of experiments in the lab, we will measure acetate concentrations during storage. The results do suggest that 10 mM acetate should be satisfactory in an ideal PSM.
FIGS. 5-8 present results on day 7 of storage of in vitro laboratory measurements which have correlated with in vivo viability in the past. These include plt ct (platelet count as a % of day 1), % discs (by oil phase microscopy), MPV (mean platelet volume as a % of day 1), dispersion of the Coulter size distribution, ATP (both as an absolute number and as a % of day 1), and os rev (osmotic reversal reaction both as an absolute number and as a % of day 1).
The medium for storage of platelets for transfusion of the present invention, therefore, offers significant advantages over prior art media. | The invention is an improved platelet storage method and composition. Medium for the storage of platelets for transfusion comprising acetate or an acetate-like compound and phosphate is disclosed. | 0 |
FIELD OF THE INVENTION
[0001] This invention relates to solar cells, in particular to those of the type known as dye sensitized cells and the reduction/prevention of unwanted back reaction.
BACKGROUND OF THE INVENTION
[0002] Conventional dye-sensitized solar cells as described by Gratzel consist of a transparent conducting substrate such as ITO on glass or plastic, on top of which is a sintered layer of titanium dioxide nanoparticles coated with dye (the anode). A hole-carrying electrolyte that typically contains iodide/tri-iodide as the electron (or hole) transfer agent is placed within the pores of and on top of this layer. The solar cell sandwich is completed by putting on top of the electrolyte a catalytic conducting electrode, often made with platinum as the catalyst (the cathode). When light is shone on the cell, the dye is excited and an electron is injected into the titanium dioxide structure. The excited, now positively charged dye oxidises the reduced form of the redox couple in the electrolyte to its oxidised form e.g. iodide goes to tri-iodide. This may now diffuse towards the platinum electrode. When the cell is connected to a load the electrons from the anode pass through the load to the cathode and at the cathode the oxidised form of the redox couple is reduced e.g. tri-iodide to iodide, completing the reaction. The oxidised form of the redox couple may also react with an electron at the anode, where the electrolyte is at an interface with either the ITO or the titanium dioxide surface—this is known as a ‘back reaction’. If this happens, the cell potential and current will be diminished. The anode conducting material can be carefully chosen to reduce this ‘back reaction’ but this is not completely possible resulting in a reduction of cell efficiency.
[0003] The use of a recombination blocking layer is known in dye sensitised solar cells primarily as a layer between the titania and the dye but also as a layer located between the active titania mesoporous layer and the substrate electrode. This latter case has been solved by others through creating an underlayer by means of sputtering, spray-pyrolysis, hydrolysis of a precursor, microwave chemical bath deposition, electro deposition or dip coating. These are inconvenient methods in that they involve solution chemistry or vacuum operations and are not necessarily conformal to the existing surface.
[0004] US 2005/0098205 discloses growing an underlayer of titania (in a Photovoltaic device) to prevent unwanted contact between a material filling the templated structure and the substrate/base electrode. This layer is grown using atomic layer deposition (ALD) but this is not disclosed as an atmospheric pressure step and so has the disadvantage of high equipment cost, plus the additional time and inconvenience of a vacuum based process.
[0005] US 2005/0098204 discloses growing a recombination-reducing inorganic layer such as alumina between the first and second or second and third charge transfer material, but not adjacent to the substrate. This layer is again grown using ALD and, as for the previous example, this is not disclosed as an atmospheric pressure step and so has the disadvantages of high equipment cost plus the additional time and inconvenience of a vacuum based process.
[0006] US 2006/0162769 discloses a solution based alternative, to give a conformal coating using chemical processes akin to ALD, i.e. hydrolysis of a metal alkoxide. The process is used to coat, for example, alumina around the mesoporous titania in a dye sensitised solar cell. This process has the inconvenience of solution chemistry, e.g. solvent and solution preparation and increased steps in the process such as a post treatment drying step/period.
PROBLEM TO BE SOLVED BY THE INVENTION
[0007] The invention aims to provide a process in which unwanted “back reaction” of the redox couple is reduced or prevented completely.
[0008] By using atmospheric pressure atomic layer deposition, AP-ALD, a convenient method of depositing the recombination blocking layer has been identified, which is conformal to the existing surface and could be applicable to a roll to roll manufacturing process. This layer may be deposited onto the conducting substrate of the anode prior to the laying down of the light collecting charge separating layer and/or may be conformally deposited over the light collecting charge separating layer prior to or after the dyeing step. Examples of the light collecting charge separating layer are mesoporous titania, zinc oxide, tin oxide.
SUMMARY OF THE INVENTION
[0009] The invention is to coat a thin layer of material onto a conducting electrode of a cell (i.e. a recombination blocking layer) by AP-ALD such that electrons can still conduct to the electrode with little resistance but reduces or prevents the unwanted back reaction of the redox couple at an electrode/electrolyte interface. Such a layer might be titanium dioxide deposited from reacting titanium tetrachloride with water on the surface of the electrode from an AP-ALD device. Alternative layers might be an oxide which might include aluminium oxide, niobium pentoxide or zinc oxide.
[0010] According to the present invention there is provided a method of laying down one or more layers of material to reduce electrolytic reaction whilst allowing electron transfer between a conductive substrate and a light collecting charge separating layer, the layer being deposited between the conductive substrate and the light collecting charge separating layer and/or over the light collecting charge separating layer, the layer being deposited by simultaneously directing a series of gas flows along elongated channels such that the gas flows are substantially parallel to a surface of the substrate and substantially parallel to each other, whereby the gas flows are substantially prevented from flowing in the direction of the adjacent elongated channels, and wherein the series of gas flows comprises, in order, at least a first reactive gaseous material, inert purge gas, and a second reactive gaseous material, optionally repeated a plurality of times, wherein the first reactive gaseous material is capable of reacting with a substrate surface treated with the second reactive gaseous material.
ADVANTAGEOUS EFFECT OF THE INVENTION
[0011] By using AP-ALD as a deposition method, thin recombination blocking layers may be deposited either on the substrate of the anode and/or conformally over the light collecting charge separating layer, prior to or after the dyeing step without the disadvantage of cost, additional time and inconvenience of a vacuum based process or the solvent and solution preparation and increased steps involved with a solution process such as a post treatment dyeing step/period.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention will now be described with reference to the accompanying drawings in which:
[0013] FIG. 1 is a flow chart describing the steps of the process used in the present invention;
[0014] FIG. 2 is a cross sectional side view of an embodiment of a distribution manifold for atomic layer deposition that can be used in the present process;
[0015] FIG. 3 is a cross sectional side view of an embodiment of the distribution of gaseous materials to a substrate that is subject to thin film deposition;
[0016] FIGS. 4A and 4B are cross sectional views of an embodiment of the distribution of gaseous materials schematically showing the accompanying deposition operation;
[0017] FIG. 5 is a graph illustrating the effect of a 10 nm AP-ALD deposited TiO 2 recombination blocking layer on performance at 0.1 sun, where the layer is deposited directly on the ITO surface;
[0018] FIG. 6 is a graph illustrating the effect of AP-ALD deposited TiO 2 recombination blocking layer thickness on dark current, where these layers are deposited directly on the ITO surface;
[0019] FIG. 7 is a graph illustrating the effect of a 3 nm AP-ALD ZnO recombination blocking layer deposited above the nanoporous TiO 2 layer on performance at 0.1 sun;
[0020] FIG. 8 is a graph illustrating the effect of combining a 3 nm AP-ALD TiO 2 recombination blocking layer deposited on the ITO surface and a ZnO recombination blocking layer deposited above the nanoporous TiO 2 layer on performance at 0.1 sun; and
[0021] FIG. 9 is a graph illustrating the effect of AP-ALD recombination blocking layers on dark current.
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIG. 1 is a generalized step diagram of a process for practicing the present invention. Two reactive gases are used, a first molecular precursor and a second molecular precursor. Gases are supplied from a gas source and can be delivered to the substrate, for example, via a distribution manifold. Metering and valving apparatus for providing gaseous materials to the distribution manifold can be used.
[0023] As shown in Step 1 , a continuous supply of gaseous materials for the system is provided for depositing a thin film of material on a substrate. The Steps in Sequence 15 are sequentially applied. In Step 2 , with respect to a given area of the substrate (referred to as the channel area), a first molecular precursor or reactive gaseous material is directed to flow in a first channel transversely over the channel area of the substrate and reacts therewith. In Step 3 relative movement of the substrate and the multi-channel flows in the system occurs, which sets the stage for Step 4 , in which second channel (purge) flow with inert gas occurs over the given channel area. Then, in Step 5 , relative movement of the substrate and the multi-channel flows sets the stage for Step 6 , in which the given channel area is subjected to atomic layer deposition in which a second molecular precursor now transversely flows (substantially parallel to the surface of the substrate) over the given channel area of the substrate and reacts with the previous layer on the substrate to produce (theoretically) a monolayer of a desired material. Often in such processes, a first molecular precursor is a metal-containing compound in gas form (for example, a metallic compound such as titanium tetrachloride) and the material deposited is a metal-containing compound (for example titanium dioxide). In such an embodiment, the second molecular precursor can be, for example, a non-metallic oxidizing compound or hydrolyzing compound, e.g. water.
[0024] In Step 7 , relative movement of the substrate and the multi-channel flows then sets the stage for Step 8 in which again an inert gas is used, this time to sweep excess second molecular precursor from the given channel area from the previous Step 6 . In Step 9 , relative movement of the substrate and the multi-channels occurs again, which sets the stage for a repeat sequence, back to Step 2 . The cycle is repeated as many times as is necessary to establish a desired film or layer. The steps may be repeated with respect to a given channel area of the substrate, corresponding to the area covered by a flow channel. Meanwhile the various channels are being supplied with the necessary gaseous materials in Step 1 . Simultaneous with the sequence of box 15 in FIG. 1 , other adjacent channel areas are being processed simultaneously, which results in multiple channel flows in parallel, as indicated in overall Step 11 .
[0025] The primary purpose of the second molecular precursor is to condition the substrate surface back toward reactivity with the first molecular precursor. The second molecular precursor also provides material as a molecular gas to combine with one or more metal compounds at the surface, forming compounds such as an oxide, nitride, sulfide, etc, with the freshly deposited metal-containing precursor.
[0026] The continuous ALD purge does not need to use a vacuum purge to remove a molecular precursor after applying it to the substrate.
[0027] Assuming that two reactant gases, AX and BY, are used, when the reaction gas AX flow is supplied and flowed over a given substrate area, atoms of the reaction gas AX are chemically adsorbed on a substrate, resulting in a layer of A and a surface of ligand X (associative chemisorptions) (Step 2 ). Then, the remaining reaction gas AX is purged with an inert gas (Step 4 ). Then, the flow of reaction gas BY and a chemical reaction between AX (surface) and BY (gas) occurs, resulting in a molecular layer of AB on the substrate (dissociative chemisorptions) (Step 6 ). The remaining gas BY and by-products of the reaction are purged (Step 8 ). The thickness of the thin film can be increased by repeating the process cycle (steps 2 - 9 ).
[0028] Because the film can be deposited one monolayer at a time it tends to be conformal and have uniform thickness.
[0029] Referring now to FIG. 2 , there is shown a cross-sectional side view of one embodiment of a distribution manifold 10 that can be used in the present process for atomic layer deposition onto a substrate 20 . Distribution manifold 10 has a gas inlet port 14 for accepting a first gaseous material, a gas inlet port 16 for accepting a second gaseous material, and a gas inlet port 18 for accepting a third gaseous material. These gases are emitted at an output face 36 via output channels 12 , having a structural arrangement described subsequently. The arrows in FIG. 2 refer to the diffusive transport of the gaseous material, and not the flow, received from an output channel. The flow is substantially directed out of the page of the figure.
[0030] Gas inlet ports 14 and 16 are adapted to accept first and second gases that react sequentially on the substrate surface to effect ALD deposition, and gas inlet port 18 receives a purge gas that is inert with respect to the first and second gases. Distribution manifold 10 is spaced a distance D from substrate 20 , provided on a substrate support. Reciprocating motion can be provided between substrate 20 and distribution manifold 10 , either by movement of substrate 20 , by movement of distribution manifold 10 , or by movement of both substrate 20 and distribution manifold 10 . In the particular embodiment shown in FIG. 2 , substrate 20 is moved across output face 36 in reciprocating fashion, as indicated by the arrow R and by phantom outlines to the right and left of substrate 20 in FIG. 2 . It should be noted that reciprocating motion is not always required for thin-film deposition using distribution manifold 10 . Other types of relative motion between substrate 20 and distribution manifold 10 could also be provided, such as movement of either substrate 20 or distribution manifold 10 in one or more directions.
[0031] The cross-sectional view of FIG. 3 shows gas flows emitted over a portion of front face 36 of distribution manifold 10 . In this particular arrangement, each output channel 12 is in gaseous flow communication with one of gas inlet ports 14 , 16 or 18 seen in FIG. 2 . Each output channel 12 delivers typically a first reactant gaseous material O, or a second reactant gaseous material M, or a third inert gaseous material I.
[0032] FIG. 3 shows a relatively basic or simple arrangement of gases. It is possible that a plurality of non-metal deposition precursors (like material O) or a plurality of metal-containing precursor materials (like material M) may be delivered sequentially at various ports in a thin-film single deposition. Alternately, a mixture of reactant gases, for example, a mixture of metal precursor materials or a mixture of metal and non-metal precursors may be applied at a single output channel when making complex thin film materials, for example, having alternate layers of metals or having lesser amounts of dopants admixed in a metal oxide material. The critical requirement is that an inert stream labeled I should separate any reactant channels in which the gases are likely to react with each other. First and second reactant gaseous materials O and M react with each other to effect ALD deposition, but neither reactant gaseous material O nor M reacts with inert gaseous material I.
[0033] The cross-sectional views of FIGS. 4A and 4B show, in simplified schematic form, the ALD coating operation performed as substrate 20 passes along output face 36 of distribution manifold 10 when delivering reactant gaseous materials O and M. In FIG. 4A , the surface of substrate 20 first receives an oxidizing material from output channels 12 designated as delivering first reactant gaseous material O. The surface of the substrate now contains a partially reacted form of material O, which is susceptible to reaction with material M. Then, as substrate 20 passes into the path of the metal compound of second reactant gaseous material M, the reaction with M takes place, forming a metallic oxide or some other thin film material that can be formed from two reactant gaseous materials.
[0034] As FIGS. 4A and 4B show, inert gaseous material I is provided in every alternate output channel 12 , between the flows of first and second reactant gaseous materials O and M. Sequential output channels 12 are adjacent, that is, share a common boundary, formed by partitions 22 in the embodiments shown. Here, output channels 12 are defined and separated from each other by partitions 22 that extend perpendicular to the surface of substrate 20 .
[0035] Notably, there are no vacuum channels interspersed between the output channels 12 , that is, no vacuum channels on either side of a channel delivering gaseous materials to draw the gaseous materials around the partitions. This advantageous, compact arrangement is possible because of the innovative gas flow that is used. Unlike gas delivery arrays of earlier processes that apply substantially vertical (that is, perpendicular) gas flows against the substrate and should then draw off spent gases in the opposite vertical direction, distribution manifold 10 directs a gas flow (preferably substantially laminar in one embodiment) along the surface for each reactant and inert gas and handles spent gases and reaction by-products in a different manner. The gas flow used in the present invention is directed along and generally parallel to the plane of the substrate surface. In other words, the flow of gases is substantially transverse to the plane of a substrate rather than perpendicular to the substrate being treated.
[0036] The above described method and apparatus are used in the present invention to lay down a blocking layer.
Example 1
Improved V Oc (Open Circuit Voltage) and I Sc (Short Circuit Current) Through Use of a TiO 2 Recombination Blocking Layer Deposited on the ITO Surface
[0037] A sample of 50 Ω/square ITO-PET was taken and a 10 nm TiO 2 recombination blocking layer was deposited onto the ITO layer using AP-ALD. The conditions used for the deposition are shown in Table 1.
[0000]
TABLE 1
AP-ALD conditions used to deposit 10 nm TiO 2 recombination blocking
layer
Bubbler 1
Material
Water
Flow rate
22
ml/min
Bubbler 2
Material
TiCl 4
Flow rate
48
ml/min
Carrier gas flow
Inert (N 2 )
2000
ml/min
Water (compressed air)
300
ml/min
Metal (N 2 )
200
ml/min
Temperature
Platen
95-105°
C.
Coating Head
50°
C.
Deposition Settings
No. of oscillations
50
Platen speed
25
mm/sec
Head height
55
μm
Thickness of TiO 2 Layer
~10
nm
[0038] This support was then used to make a dye sensitised solar cell (cell A). To act as a control, an untreated piece of 50 Ω/square ITO-PET was used to create another dye sensitised solar cell (control).
[0039] Some titanium dioxide was dried in an oven at 90° C. overnight prior to use. This was a titanium dioxide sample which had an average particle size of 21 nm (Degussa Aeroxide P25, specific surface area (BET)=50+/−15 m 2 /g). The flexible dye sensitised solar cells relating to the invention (cell A) and the comparison (control) were fabricated as follows.
[0040] Approximately 15-20 μm thick nanoporous TiO 2 films were deposited onto both the sample of 50 Ω/square ITO-PET covered with the 10 nm AP-ALD TiO 2 layer and the untreated sample of 50 Ω/square ITO-PET by dispersing the dried TiO 2 in a mixture of dry Methyl Ethyl Ketone and Ethyl Acetate in the following amounts for each sample:
[0000] Degussa P25 TiO 2 (21 nm particles) 1.35 g Methyl Ethyl Ketone 45 g Ethyl Acetate 5 g
The resulting mixtures were sonicated for 15 minutes before being sprayed onto the two samples of conducting plastic substrate from a distance of approx 25 cm using a SATAminijet 3 HVLP spray gun with a 1 mm nozzle and 2 bar nitrogen carrier gas. The layers were allowed to dry in an oven at 90° C. for one hour, before being placed between two sheets of Teflon, sandwiched between two polished stainless steel bolsters and compressed with a pressure of 3.75 tonnes/cm 2 for 15 seconds. The sintered layers were then allowed to dry for a further hour at 90° C.
[0041] The sintered layers were then sensitised by placing them in a 3×10 +4 mol dm −3 ethanolic solution of ruthenium cis-bis-isothiocyanato bis(2,2′bipyridyl-4,4′dicarboxylic acid) overnight.
[0042] Platinum coated stainless steel foil electrodes were prepared by sputter deposition under vacuum.
[0043] The dye sensitised TiO 2 layers and the platinum counter electrode were arranged in a sandwich type configuration with an ionic liquid electrolyte contained within a gasket. The electrolyte comprised:
0.1M LiI
[0044] 0.6M DMPII (1,2,dimethyl-3-propyl-imidazolium iodide)
0.05M I 2
0.5M N-methylbenzimidazole
Solvent=MPN (Methoxypropionitrile)
[0045] Following fabrication, the dye sensitised solar cells were characterised by placing them under a source that artificially replicated the solar spectrum in the visible region to provide an illumination of 0.10 sun.
[0046] The data in FIG. 5 demonstrate that cell A (the invention comprising a 10 nm AP-ALD TiO 2 recombination blocking layer) has higher open circuit voltage (Voc) and short circuit current (Isc) compared to the control where no recombination blocking layer was employed.
Example 2
Effect of Thickness of AP-ALD TiO 2 Recombination Blocking Layer, Deposited on the ITO Surface, on Dark Current
[0047] One way of assessing the effectiveness of a recombination blocking layer is to measure the dark current.
[0048] Samples of 13 Ω/square ITO-PEN were taken and various thicknesses of TiO 2 recombination blocking layers were deposited onto the ITO layer of each using AP-ALD. The conditions used for the depositions are shown in Table 2.
[0000] TABLE 2 AP-ALD conditions used to deposit various thicknesses of TiO 2 recombination blocking layer for cells B, C & D Bubbler 1 Material Water Flow rate 22 ml/min Bubbler 2 Material TiCl 4 Flow rate 48 ml/min Carrier gas flow Inert (N 2 ) 2000 ml/min Water (compressed air) 300 ml/min Metal (N 2 ) 200 ml/min Temperature Platen 95-105° C. Coating Head 50° C. Deposition Settings Platen speed 25 mm/sec Head height 55 μm Cell B No. of oscillations 10 Thickness of TiO 2 Layer ~3 nm Cell C No. of oscillations 25 Thickness of TiO 2 Layer ~6 nm Cell D No. of oscillations 50 Thickness of TiO 2 Layer ~18 nm
Dye sensitised solar cells were then fabricated using the same method described in example 1. The same control from example 1 (i.e. no recombination blocking layer present but with 13 Ω/square ITO-PEN as the anode substrate) was used in this example.
[0049] The dark currents for cells B (2 nm AP-ALD TiO 2 recombination blocking layer), C (6 nm AP-ALD TiO 2 recombination blocking layer), D (14 nm AP-ALD TiO 2 recombination blocking layer) and the control cell (no AP-ALD TiO 2 recombination blocking layer) were then measured and are shown in FIG. 6 .
[0050] FIG. 6 demonstrates that as the thickness of the AP-ALD TiO 2 recombination blocking layer is increased from zero to 18 nm, so a higher voltage is required before current will flow in the opposite direction due to recombination back reactions.
Example 3
Improved V Oc (Open Circuit Voltage) Through Use of a ZnO Recombination Blocking Layer Conformally Deposited on the Surface of the Nanoporous TiO 2 Layer
[0051] Some titanium dioxide was dried in an oven at 90° C. overnight prior to use. This was a titanium dioxide sample which had an average particle size of 21 nm (Degussa Aeroxide P25, specific surface area (BET)=50+/−15 m 2 /g). The flexible dye sensitised solar cells relating to the invention (cell E) and the comparison (control) were fabricated as follows.
[0052] Approximately 30 μm thick nanoporous TiO 2 films were deposited onto two separate pieces of 13 Ω/square ITO-PEN by dispersing the dried TiO 2 in a mixture of dry Methyl Ethyl Ketone and Ethyl Acetate in the following amounts for each sample:
[0000]
Degussa P25 TiO 2 (21 nm particles)
1.35 g
Methyl Ethyl Ketone
45 g
Ethyl Acetate
5 g
[0053] The resulting mixtures were sonicated for 15 minutes before being sprayed onto the two samples of conducting plastic substrate from a distance of approximately 25 cm using a SATAminijet 3 HVLP spray gun with a 1 mm nozzle and 2 bar nitrogen carrier gas. The layers were allowed to dry in an oven at 90° C. for one hour, before being placed between two sheets of Teflon, sandwiched between two polished stainless steel bolsters and compressed with a pressure of 3.75 tonnes/cm 2 for 15 seconds. The sintered layers were then allowed to dry for a further hour at 90° C.
[0054] For the cell relating to this invention a 3 nm ZnO recombination blocking layer was then conformally deposited onto the surface of the nanoporous TiO 2 layer using AP-ALD. The conditions used for the deposition are shown in Table 3.
[0000]
TABLE 3
AP-ALD conditions used to deposit 3 nm ZnO recombination
blocking layer
Bubbler 1
Material
Water
Flow rate
22
ml/min
Bubbler 2
Material
Diethyl Zinc
Flow rate
49
ml/min
Carrier gas flow
Inert (N 2 )
2000
ml/min
Water (compressed air)
300
ml/min
Metal (N 2 )
200
ml/min
Temperature
Platen
95-105°
C.
Coating Head
50°
C.
Deposition Settings
No. of oscillations
40
Platen speed
50
mm/sec
Head height
55
μm
Thickness of ZnO Layer
~3
nm
[0055] The cell relating to the comparison (control) did not have a ZnO layer deposited on the surface of the nanoporous TiO 2 layer.
[0056] The samples were then sensitised by placing them in a 3×10 +4 mol dm −3 ethanolic solution of ruthenium cis-bis-isothiocyanato bis(2,2′bipyridyl-4,4′dicarboxylic acid) overnight.
[0057] Platinum coated stainless steel foil electrodes were prepared by sputter deposition under vacuum.
[0058] The dye sensitised TiO 2 layers and the platinum counter electrode were arranged in a sandwich type configuration with an ionic liquid electrolyte in between. The electrolyte comprised:
0.1M LiI
[0059] 0.6M DMPII (1,2,dimethyl-3-propyl-imidazolium iodide)
0.05M I 2
0.5M N-methylbenzimidazole
Solvent=MPN (Methoxypropionitrile)
[0060] Following fabrication, the dye sensitised solar cells were characterised by placing under a source that artificially replicated the solar spectrum in the visible region to provide an illumination of 0.10 sun.
[0061] The data in FIG. 7 demonstrate that cell E (the invention comprising a 3 nm AP-ALD ZnO recombination blocking layer deposited on the surface of the nanoporous TiO 2 layer) has higher open circuit voltage (Voc) compared to the control where no recombination blocking layer was employed.
Example 4
Improved V oc (Open Circuit Voltage) Through Use of a TiO 2 Recombination Blocking Layer Deposited on the ITO Substrate in Combination with a ZnO Recombination Blocking Layer Conformally Deposited on the Surface of the Nanoporous TiO 2 Layer
[0062] A sample of 13 Ω/square ITO-PEN was taken and a 3 nm TiO 2 recombination blocking layer was deposited onto the ITO layer using AP-ALD. The conditions used for the deposition are shown in Table 4.
[0000]
TABLE 4
AP-ALD conditions used to deposit 3 nm TiO 2 recombination
blocking layer
Bubbler 1
Material
Water
Flow rate
22
ml/min
Bubbler 2
Material
TiCl 4
Flow rate
48
ml/min
Carrier gas flow
Inert (N 2 )
2000
ml/min
Water (compressed air)
300
ml/min
Metal (N 2 )
200
ml/min
Temperature
Platen
95-105°
C.
Coating Head
50°
C.
Deposition Settings
No. of oscillations
10
Platen speed
25
mm/sec
Head height
55
μm
Thickness of TiO 2 Layer
~3
nm
[0063] This support was then used to make a dye sensitised solar cell (cell F). To act as a control, an untreated piece of 13 Ω/square ITO-PEN was used to create another dye sensitised solar cell (control).
[0064] Some titanium dioxide was dried in an oven at 90° C. overnight prior to use. This was a titanium dioxide sample which had an average particle size of 21 nm (Degussa Aeroxide P25, specific surface area (BET)=50+/−15 m 2 /g). The flexible dye sensitised solar cells relating to the invention (cell F) and the comparison (control) were fabricated as follows.
[0065] Approximately 30 μm thick nanoporous TiO 2 films were deposited onto the two separate pieces of 13 Ω/square ITO-PEN by dispersing the dried TiO 2 in a mixture of dry Methyl Ethyl Ketone and Ethyl Acetate in the following amounts for each sample:
[0000]
Degussa P25 TiO 2 (21 nm particles)
1.35 g
Methyl Ethyl Ketone
45 g
Ethyl Acetate
5 g
[0066] The resulting mixtures were sonicated for 15 minutes before being sprayed onto the two samples of conducting plastic substrate from a distance of approximately 25 cm using a SATAminijet 3 HVLP spray gun with a 1 mm nozzle and 2 bar nitrogen carrier gas. The layers were allowed to dry in an oven at 90° C. for one hour, before being placed between two sheets of Teflon, sandwiched between two polished stainless steel bolsters and compressed with a pressure of 3.75 tonnes/cm 2 for 15 seconds. The sintered layers were then allowed to dry for a further hour at 90° C.
[0067] For the cell relating to this invention (cell F) a 3 nm ZnO recombination blocking layer was then conformally deposited onto the surface of the nanoporous TiO 2 layer using AP-ALD. The conditions used for the deposition are shown in Table 5.
[0000]
TABLE 5
AP-ALD conditions used to deposit 3 nm ZnO recombination
blocking layer
Bubbler 1
Material
Water
Flow rate
22
ml/min
Bubbler 2
Material
Diethyl Zinc
Flow rate
49
ml/min
Carrier gas flow
Inert (N 2 )
2000
ml/min
Water (compressed air)
300
ml/min
Metal (N 2 )
200
ml/min
Temperature
Platen
95-105°
C.
Coating Head
50°
C.
Deposition Settings
No. of oscillations
40
Platen speed
50
mm/sec
Head height
55
μm
Thickness of ZnO Layer
~3
nm
[0068] The samples were then sensitised by placing them in a 3×10 −4 mol dm −3 ethanolic solution of ruthenium cis-bis-isothiocyanato bis(2,2′bipyridyl-4,4′dicarboxylic acid) overnight.
[0069] Platinum coated stainless steel foil electrodes were prepared by sputter deposition under vacuum.
[0070] The dye sensitised TiO 2 layers and the platinum counter electrode were arranged in a sandwich type configuration with an ionic liquid electrolyte in between. The electrolyte comprised:
0.1M LiI
[0071] 0.6M DMPII (1,2,dimethyl-3-propyl-imidazolium iodide)
0.05M I 2
0.5M N-methylbenzimidazole
Solvent=MPN (Methoxypropionitrile)
[0072] Following fabrication, the dye sensitised solar cells were characterised by placing under a source that artificially replicated the solar spectrum in the visible region to provide an illumination of 0.10 sun.
[0073] The data in FIG. 8 demonstrate that cell F (the invention comprising a 3 nm AP-ALD TiO 2 recombination blocking layer deposited on the ITO surface and a 3 nm AP-ALD ZnO recombination blocking layer deposited on the surface of the nanoporous TiO 2 layer) has considerably higher open circuit voltage (Voc) compared to the control where no recombination blocking layers were employed.
Example 5
Effect of the AP-APLD Recombination Blocking Layer on Dark Current
[0074] To assess the effectiveness of the various recombination blocking layers, dark currents were measured on cell B (TiO 2 blocking layer on ITO surface), cell E (ZnO blocking layer deposited on the nanoporous TiO2 surface), cell F (TiO 2 blocking layer on ITO surface & ZnO blocking layer deposited on the nanoporous TiO2 surface) and the control (see FIG. 9 ).
[0075] FIG. 9 demonstrates that when either the AP-ALD TiO 2 or ZnO recombination blocking layers were present on the ITO surface or the surface of the nanoporous TiO 2 layer respectively, a higher voltage was required before current will flow in the opposite direction due to recombination back reactions when the cell is not illuminated. When both recombination blocking layers were combined within one cell, even higher voltage was required. This demonstrates a considerable reduction in recombination reactions is present.
[0076] These examples demonstrate that AP-ALD can be used to deposit recombination blocking layers which are conformal to the existing surface and could be applicable to a roll to roll manufacturing process employing substrates only compatible with low temperature processing. This layer may be deposited onto the anode substrate prior to the mesoporous titania layer being laid down or may be conformally deposited over the mesoporous titania layer, prior to or after the dyeing step.
[0077] The above examples were performed using titanium dioxide. However any metal compound with group VI elements may be used.
[0078] The thickness of the layer may be up to 100 nm. Preferably however the thickness is less than 20 nm, even more preferably less than 5 nm.
[0079] The substrate is not limited to ITO-PET. Other materials may be used, for example but not limited to, ITO-PEN, transparent conductive oxide (TCO) coated film support materials, TCO coated glass.
[0080] The invention has been described in detail with reference to preferred embodiments thereof. It will be understood by those skilled in the art that variations and modifications can be effected within the scope of the invention. | A method of laying down one or more layers of material to reduce electrolytic reaction whilst allowing electron transfer between a conductive substrate and a light collecting charge separating layer, the layer being deposited between the conductive substrate and the light collecting charge separating layer and/or over the light collecting charge separating layer, the layer being deposited by atmospheric pressure atomic layer deposition. | 2 |
RELATED CASES
This application is a divisional of U.S. patent application Ser. No. 08/289,901, filed Aug. 12, 1994, U.S. Pat. No. 5,695,510, which was a continuation-in-part of U.S. patent application Ser. No. 08/055,042, filed Apr. 29, 1993, U.S. Pat. No. 5,342,380, which was a continuation of U.S. patent application Ser. No. 07/839,411, filed Feb. 20, 1992, now U.S. Pat. No. 5,261,922, issued Nov. 16, 1993.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to ultrasonic surgical instruments and, more particularly, to an improved ultrasonic knife.
2. Description of Related Art
The use of ultrasonic surgical instruments for cutting various types of tissues and/or removal of cement within the body is well known. An ultrasonic surgical instrument commonly comprises a knife blade connected to an ultrasonic oscillation source. The edge of the knife blade is brought into direct contact with the tissue being operated on and vibrated at ultrasonic frequencies. Conventional ultrasonic surgical instruments are used to cut or shatter a variety of living tissues such as the soft tissue found in cataracts, the cartilaginous tissue found around bones, and the osseous tissue of the bone itself. Surgeons are also finding ultrasonics to be an excellent tool for the removal of cements, such as, for example, Polymethylmethacrylate (PMMA) which is frequently used to affix a prosthetic hip joint to the existing femur.
The mechanical oscillation at the end of an ultrasonically vibrated knife blade reduces the amount of pressure required to initiate and propagate a cut or incision which allows the surgeon to concentrate more on the direction of cut. Advantageously, the surrounding tissue experiences minimal stretching and tearing as compared to procedures utilizing conventional stationary blades.
Problems which can be associated with ultrasonic surgery include excessive heat generation, tearing of tissue, or inadvertent cutting of nearby structures. Other problems have been associated with the ergonomics of ultrasonic surgical instruments. Moreover, different surgeons desire different tactile feedback and operating performance. The prior art generally has demonstrated a lack of understanding of the tactile feedback necessary to carefully re-sect different types of living tissues with one particular knife.
Some examples of prior art have attempted to reduce the "thermal footprint" of the ultrasonic cutting tool. For example, in U.S. Pat. No. 5,026,387 issued to Thomas, an ultrasonic surgical cutting tool is disclosed which automatically shuts off upon removal from the tissue. The automatic shut-off switch reduces the time that the surgical cutting knife is vibrating and thus decreases its heat build-up. U.S. Pat. No. 4,188,952 issued to Loschilov et al., discloses an ultrasonic surgical instrument which relies on a pentagonal cross section to reduce the thermal damage to the side surfaces of the tissue being cut because of a smaller area of surface contact. The thermal footprint of an ultrasonic surgical knife is defined by its surface area in contact with the tissue, both frontally and on the sides. In general, the inventions of the prior art have been fairly simple in their approach to reducing thermal footprint of ultrasonic blades and have failed to provide any real sophistication for the design of these tools which is sorely needed.
A need exists for an improved ultrasonic surgical blade which gives better feedback when cutting through various types of tissue and provides enhanced ergonomics to surgeons.
SUMMARY OF THE INVENTION
There is provided in accordance with one aspect of the present invention, a method of cavitation-assisted surgery utilizing an ultrasonic knife. An ultrasonic knife is provided, of the type having a source of ultrasonic vibrations, a knife blade coupled to the source, and a control for selectively causing the source to produce ultrasonic vibrations in the knife blade.
The source is activated to induce reciprocal movement of the knife blade throughout a predetermined axial stroke amplitude, and the blade is contacted with the tissue to be cut. The formation of cavitation bubbles is induced in the fluid media surrounding the knife blade, and the cavitation bubbles are thereafter permitted to implode, thereby producing shockwaves for breaking the tissue bond adjacent the cutting edge of the knife blade.
Preferably, the inducing formation of cavitation bubbles step is accomplished by providing the knife blade with a surface texture for creating cavitation bubbles. In one embodiment, the surface texture comprises a plurality of rounded spherical or hemispherical irregularities, having a width within the range of from about 20 microns to about 100 microns. The surface irregularities may be either pitted recesses such as by acid etching or other techniques known in the art, or beads adhered to the surface of the blade.
The inducing formation of cavitation bubbles may alone or in addition to the blade texturing be enhanced by providing a plurality of surfaces on the cutting edge of the knife, which extend generally perpendicular to the longitudinal axis of ultrasonic energy propagation through the knife. In a further aspect of the present method, inducing formation of cavitation bubbles may also be enhanced by modulating the energy driving the knife to include at least a first low frequency component for increasing cavitation, and a high frequency component for minimizing the depth of penetration of heat generated by the blade into the adjacent tissue.
In accordance with a further aspect of the present invention, there is provided an ultrasonic knife for conducting wet, cavitation-assisted surgery, or dry, cauterizing surgical procedures. The knife comprises a source of ultrasonic vibrations, a knife blade coupled to the source, and a control for selectively causing the source to produce ultrasonic vibrations, thereby inducing reciprocal movement of the knife blade through a predetermined stroke.
The blade comprises at least two teeth defining a recess therebetween, wherein the distance between the two teeth is no more than about the predetermined stroke. Preferably, the distance between the two teeth is no more than about 80% of the predetermined stroke. The predetermined stroke is preferably within the range of from about 0.001 to about 0.002 inches, and, most preferably, the predetermined stroke is approximately 0.0015 inches.
The width of each of the teeth is within the range of from about 30% to about 60% of the stroke, and preferably the width of each of the teeth is about 50% of the stroke. Preferably, a plurality of teeth are provided on the blade, extending throughout the cutting surface thereof.
The recess formed between each two adjacent teeth comprises a bottom portion and two sidewall portions, each sidewall portion terminating in a tooth edge at the most lateral extent, and the distance between the bottom of the recess and the tooth edge is within the range of from about 20% to about 100% of the stroke. Preferably, the distance between the bottom of the recess and the tooth edge is about 80% of the stroke.
Preferably, the bottom of the recess and sidewalls of the recess merge to form a generally parabolic shape. Alternatively, the two sidewalls are generally parallel to each other, and generally perpendicular to the bottom of the recess. In general, the two sidewalls and the bottom of the recess define a continuous boundary of the recess, and at least a portion of the boundary extends perpendicular to the longitudinal axis of ultrasonic energy propagation through the knife, and at least a second portion extends generally parallel to the longitudinal axis of ultrasonic propagation energy through the knife.
In a preferred embodiment, in which the thermal footprint of the knife is minimized, the blade comprises a generally planar body portion having a proximal connection end and at least one cutting edge thereon, and a width in a central region thereof which is less than the width at least one point between the central region thereof and the cutting edge.
In accordance with a further aspect of the present invention, there is provided a blade for ultrasonic surgery. The blade comprises a generally planar body having at least one cutting edge thereon and a longitudinal axis. A connector couples the body to a source of ultrasonic vibrations which oscillates the planar body at a predetermined stroke length. The cutting edge carries a plurality of teeth formed thereon, each tooth comprises a pair of generally parallel sidewall portions which terminate at a tooth end. The tooth end extends generally perpendicular to the sidewall portions and generally parallel to the longitudinal axis.
In accordance with another aspect of the present invention, there is provided an ultrasonic knife comprising a source of ultrasonic vibrations. The knife also includes a knife blade coupled to said source, the knife blade having a cutting edge which supports a plurality of teeth having a spacing apart from one another of 10 microns or less. A control selectively causes the source to produce ultrasonic vibrations to induce reciprocal movement of the knife blade through a predetermined stroke length. The cutting edge of the knife blade is formed of a material having a Rockwell (C) hardness of 55 or greater and an ultimate yield strength generally about four times greater than internal stresses produced by the ultrasonic vibration in the material. In a preferred embodiment, the material is selected from a group of hard, tough materials consisting of diamond, sapphire, and metal/ceramic composites or coatings.
In accordance with another aspect of the present invention, there is provided a blade for ultrasonic surgery comprising a generally planar body. The body has at least one cutting edge formed by the intersection of two curved surfaces which extend along a portion of the length of the blade on opposite sides of the planar body. A connector couples the body to a source of ultrasonic vibrations such that the planar body of the blade oscillates. In a preferred embodiment, a plurality of teeth are formed on the cutting edge, each tooth having a generally blunt, squared tip.
In accordance with a preferred method of performing cavitation assisted surgery utilizing an ultrasonic knife, an ultrasonic knife is provided of the type having a source of ultrasonic vibrations, a knife blade coupled to the source, and a controller for selectively causing the source to produce ultrasonic vibrations in the knife blade. The source is activated to induce reciprocal movement of the knife blade throughout a predetermined axial stroke amplitude. The knife blade is contacted with the tissue to be cut, and the formation of cavitation bubbles is induced in the fluid media surrounding the knife blade. The cavitation bubbles are permitted to implode, thereby producing shock waves which break the tissue bond adjacent the cutting edge of the knife blade. In a preferred method, a cavitation enhancing fluid is introduced at the surgical site to increase the effects of the cavitation assisted cutting.
In accordance with an additional feature of the present invention, there is provided a handpiece for an ultrasonic tool. The handpiece includes a transducer to produce ultrasonic vibrations which is interposed between an acoustical concentrator and a bulk head. The transducer comprises at least two piezo-electric washers interposed between a front block and a heel slug. A central bolt passes through aligned holes in the washers and interconnecting the front block and the heel slug to compress the washers. The central bolt includes an isolation region which extends proximally beyond an end of the heel slug to support the bulk head at a distance from the heel slug. The isolation region advantageously has a cross-sectional area no greater than one-tenth of the cross-sectional area of the heel slug.
In accordance with another aspect of the present invention, a blade for ultrasonic surgery includes a generally planar body having at least one cutting edge thereon. The cutting edge is formed at the intersection of at least one curved surface and at least one straight surface for the cutting edge. A connector, which is attached to the planer body, couples the body to a source of ultrasonic vibrations which oscillate the planar body. In a preferred embodiment, the cutting edge includes a plurality of teeth. Each tooth has an end formed by the intersection of one of the at least one curved surface and one of the at least one straight surface. Each tooth also is arranged so that the curved surface which forms the edge of the tooth extends into the blade from a side of the blade opposite that from which curved surfaces of adjacent teeth extend into the blade.
Further advantages and features of the present invention will become apparent to one of skill in the art from the detailed description of preferred embodiment which follows, when taken together with the claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of the ultrasonic surgical tool system of the present invention;
FIG. 2 is a side view of the preferred cutting blade of the present invention;
FIG. 3 is a top view of the blade of FIG. 2;
FIG. 4 is a cross section of an edge of the blade of FIG. 2 along line 4--4;
FIG. 4a is an alternative cross-sectional configuration of the blade edge of FIG. 2;
FIG. 5 is an enlargement of the teeth of the blade of FIG. 2 illustrating the preferred depth and pitch;
FIG. 5a is an alternative tooth configuration as viewed in cross-section;
FIG. 6 is a top view of the ultrasonic surgical tool of FIG. 1;
FIG. 7 is an exploded view of the ultrasonic surgical tool of FIG. 1;
FIG. 8 is a cross section of the ultrasonic surgical tool along lines 8--8 of FIG. 6;
FIG. 8a is a cross section of an ultrasonic surgical tool in accordance with another embodiment of the present invention;
FIG. 9 is a top view of an ultrasonic medical tool of the present invention showing a handpiece, an extender and a preferred blade.
FIG. 10 is a partial cross-sectional view of the ultrasonic medical tool of FIG. 9 taken along line 10--10 illustrating two junctions of the present invention;
FIG. 11 is an exploded partial cross-sectional view of the junctions of FIG. 10;
FIG. 12 is an exploded perspective view of one of the junctions of FIG. 10, illustrating the generally cylindrical male component on the proximal end of a surgical tool having a pair of splines interrupted by a pair of flats;
FIG. 12a is a cross-sectional view of the junction of FIG. 12 taken along line 12a--12a;
FIG. 13 is an assembly perspective view of the junction of FIG. 12 with a male component inserted into a female component;
FIG. 14 is an assembly perspective view of the junction of FIG. 13 with the components rotated to engage corresponding splines of each component;
FIG. 15 is a cross-sectional view of the junction of FIG. 13 taken along lines 15--15;
FIG. 16 is a cross-sectional view of the junction of FIG. 14 taken along lines 16--16;
FIG. 17 is a top view of an ultrasonic medical tool of the present invention showing a handpiece, an extender and an alternative flat blade held in a split chuck;
FIG. 18 is a side view of the split chuck and collet of FIG. 17 along lines 18--18;
FIG. 19 illustrates a knife blade carrier in accordance with the present invention; and
FIG. 20 is an end elevational view of the blade carrier of FIG. 19.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, the improved ultrasonic surgical tool provides enhanced tactile feedback to the surgeon and may be adjusted to customize the feedback, depending on the preference of the surgeon. Additionally, the ultrasonic tool of the present invention can be configured to cut a wide variety of tissues by altering the blade structure alone, or in combination with the operating mode. It thus is understood that the general shape of the present surgical tool can be changed to be similar to any of the 75 plus conventional shapes available from several microtome/sharps manufacturers, which are specifically designed to cut specific tissue or material type, while still incorporating the advantages of the present invention. Incorporation of the invention into known blade configurations will give a normally "static" blade/tool/sharps improved capabilities, as discussed below. The following discussion of the invention, however, will focus on an improved cutting tool configuration in combination with the other aspects of the present invention.
As schematically shown in FIG. 1, an ultrasonic surgical system 24 ultimately vibrates a surgical blade 26. The blade 26 couples to an ultrasonic transducer (not shown) mounted in a handpiece 28 which is driven by a control system 30. A surgeon grasps the handpiece 28 and manipulates the blade 26 within a patient. A cable 32 transmits the ultrasonic driving signals from the control system 30 to the transducer within the handpiece 28.
Referring to FIG. 2, a preferred embodiment of surgical blade 26 is shown. The blade 26 includes a cutting section 34 at its distal end. As seen best in FIG. 4, the cross section of the cutting section 34 reveals a central channel or relief 36 formed into each side. The blade 26 is symmetric about a vertical plane through the center. The relief portion 36 allows the knife blade 26 to cut through various types of tissue with a minimum thermal footprint. The thermal footprint of a blade includes all the surfaces in contact with the tissue. The blade 26 vibrating at ultrasonic frequencies can produce a substantial amount of heat from the frictional and ultrasonic contact with the tissue. The size of the relief 36, or percentage of area of the blade 26 out of contact with the tissue, directly affects the thermal footprint.
Adjacent the relief 36, tissue contact surfaces 38 extend for a distance generally parallel to the plane of the blade 26 towards the edge of the blade 26. In general, the width of each contact surface 38 in this plane is within the range of from about 0.0 to about 0.050 inches, and preferably within the range of from about 0.015 to about 0.025 inches .
These contact surfaces 38 represent the widest portion of the blade 26 along an axis transverse to the plane of the blade and produce a substantial amount of thermal friction with the tissue. Typically, the thickness of the blade through contact surface 38 is within the range of from about 0.010 to about 0.050 inches, and preferably within the range of from about 0.015 to about 0.025 inches. The size of the contact surfaces 38 also directly affects the thermal footprint. Smaller contact surfaces 38 reduce the thermal footprint of the blade 26.
With reference to FIG. 4, the sharpened edge 27 of the blade 26 comprises a first taper 40 which is separated from the contact surface 38 by a second taper 42. Both the first and second tapers widen in the medial direction.
As illustrated in FIG. 4, the first taper 40 is formed by the intersection of two inclined surfaces 41. Each inclined surface 41 tapers from a vertical central axis at a taper angle ranging between about 5° and about 45°, and more preferably between about 15° and about 30°. The taper angle most preferably equals about 30°. Consequently, the first taper 40 has an included angle ranging between about 10° and about 90°, and preferably equals about 60°. It has been determined that taper angles within the above ranges provide a good balance of mechanical sharpness and hemostatic tissue activity, as discussed below.
It is also understood that the cross-sectional profile of the blade edge 27 can be changed to obtain a different balance of these effects. For instance, FIG. 4a illustrates an alternative cross-sectional shape of a first taper 43. In this embodiment, a pair of intersecting curved surfaces 47 (preferably concave surfaces) form the first taper 43, thus giving the first taper 43 a "hollow-ground" shape. Each surface desirably has a radius of curvature ranging between about an eighth (1/8) to about ten (10) times the blade thickness, more preferably between about a quarter (1/4) to about five (5) times the blade thickness, and most preferably between about a half (1/2) to about two (2) times the blade thickness. The hollow-ground configuration of the first taper 43 also has a shorter depth 49, as measured in the direction of the vertical central axis, in comparison to the cross-sectional profile of the blade edge 27 illustrated in FIG. 4. The short, hollow-ground profile provides for a sharper cutting edge at the tip with increased thermal properties directly behind the tip. Of course, the smaller the radii of the curved surfaces, the closer these two effects (sharpness and thermal hemostatic activity) are brought together.
With reference back to FIG. 4, the second taper 42 desirably range between about 3° and about 45°, and more preferably the taper is about 8°. The angles of the tapered portions directly affect the character of cut and associated drag, or feel, experienced by the surgeon. A short taper, such as 45 degrees, would provide a duller blade generating more cavitation, drag and hemostasis. A longer, sharper taper would have substantially less tissue differentiation. The blade may have a continuous, sharp cutting edge as with conventional scalpels, or may have serrations or teeth as described below.
Referring now to FIG. 5, a preferred shape of the serrations is shown enlarged. The serrations comprise parabolic-shaped recesses 44 separated by outwardly protruding teeth 46. As seen in FIG. 5a, the teeth 46 also could have an alternate off-set or `set` where the blade includes hollow ground teeth. That is, the hollow ground, which forms the teeth, can extend into the blade from only one blade side and can alternate between the sides so as to give the blade edge 27 a wider kerf, as seen in FIG. 5a. This would cause additional drag, but also would allow better self-cleaning of the teeth 46, especially on harder material which tends to clog teeth.
With reference back to FIG. 5, the teeth 46 desirably are spaced a certain distance apart to result in optimal cutting. Advantageously, the teeth 46 are separated by a distance 46c of less than one longitudinal stroke of the blade 26 to ensure that the tips of at least two teeth 46 cross any one point in a single stroke. The spacing 46c of the teeth 46 is most preferably at most eight-tenths of the blade stroke so that every tissue bond is contacted by at least two teeth 46 during each stroke, while internal material stresses are minimized.
It is understood that the effect of mechanical cutting increases as the number of teeth, which pass over a particular tissue bond during each stroke, increases. Thus, the finer the teeth spacing for a given stroke length, the greater the effect of mechanical cutting. It has been determined that blades formed of an extremely hard material can support extremely fine teeth while withstanding the resultant internal material stresses produced by the ultrasonic vibrations at the cutting edge. For instance, materials with a Rockwell (C) hardness of 55 or greater can support teeth having a spacing between about 1 to 10 microns, and materials with a Rockwell (C) hardness of 65 or greater can support teeth having a spacing closer than 1 micron apart from one another. The material, however, should be selected such that the resultant internal material stresses produced by the acceleration and deceleration of the vibrating material stay below twenty-five percent (25%) of the ultimate yield strength of the material. Examples of suitable materials are diamond, sapphire, and composites formed by a metal base, such as, for example, aluminum alloy, high carbon stainless steel, or preferably titanium alloy, coated with a hard coating, such as, for example, a ceramic. Preferred examples of suitable ceramics are Tungsten carbide (Rc 74), titanium nitride (Rc 70), silicon-carbide (Rc 70+), aluminum oxide (Rc 78), plasma-chrome oxide (Rc 74) (i.e., chrome oxide applied by a plasma ion application) hard chrome plating (Rc 65), dense chrome plating (Rc 70), or electroless nickel plating after heat treatment (Rc 62).
The advantageous shape of the teeth 46 of the blade 26, shown in FIG. 5, provides an enhanced feel of cut at all times. A straight-edged ultrasonic knife blade will slip through tissue with a substantially constant resistance due to the blade edge being everywhere parallel to the tissue. Ultimately, the surgeon might apply more pressure than necessary, without realizing the depth of cut, and sever tissue not intended to be cut.
The contour of the recesses 44 on the ultrasonic blade 26 of the present invention changes the angle of the portion of the blade edge which strikes the tissue. During light cuts, the surgeon notices little resistance as bond severing occurs primarily at the tip edges of the teeth 46 parallel to the plane of uncut tissue ahead of the cutting edge. To provide ample light cutting surfaces, the width 46b of the tips of the teeth 46 are preferably 30-60% of the stroke amplitude, and most desirably the width 46b is 50% of the stroke.
Slightly more pressure results in cutting at the sidewalls 45 of the recesses 44, at least a portion of which is perpendicular to the plane of uncut tissue. The sidewalls 45 extend from the tip 46 of the teeth to the bottom 44 of the recess a sufficient distance to expose the perpendicular surfaces to the tissue. To ensure this exposure while retaining some strength for the extending teeth 46, the depth 46a of the sidewalls 45 is 20-100% of the blade stroke amplitude, and preferably the depth 46a is 80% of the stroke. Where a hollow-ground cutting edge 27 is used, it also is understood that if the depth 46a of the tooth 46 extends over the full radius of the curved surface 47 of the first taper 43, cavitation effects will be increased and thermal effects will be reduced.
An increase in the downward force causes more of the sidewalls 45 perpendicular to the tissue, between the teeth 46 to contact the tissue, resulting in a change of resistance due to the increased surface area contact at a high vector angle. Thus, the surgeon experiences a greater resistance as the blade 26 is pressed harder into the tissue, and may adjust accordingly to prevent inadvertent injury to the patient.
The surface texture of the blade 26 directly affects the amount of frictional and ultrasonic heat generation, in addition to the level of cavitation. Highly polished surfaces tend to slide through the tissue with minimal friction and associated heat generation and sound transfer. The tapered surfaces 40, 42 and the recessed region 36 are preferably polished to minimize thermal effects (i.e., thermal transfer) to the tissue. Concurrently, if dry cutting is preferred, the contact surfaces 38 may be finished slightly rougher to ensure heat will build up mostly at this region and increased hemostasis will occur. Alternatively, the surfaces of the blade 26 may be roughened all over, a saline solution introduced at the operative site, and the blade oscillated at preferred rates to minimize thermal effects yet increase the amount of cavitation. Such a situation is seen in brain surgery where a constant stream of water, or other coolant fluid, is applied to the incision area, and the majority of the cut is cavitation-assisted.
Referring again to FIGS. 2 and 3, a transition section 48 alters the cross section of the blade 26 from the flat cutting section 34 to a generally cylindrical portion 50 comprising opposing wrench flats 52. The transition section 48 amplifies the gain of the ultrasonic oscillations. A coupling member 54 adjacent to the cylindrical portion 50 mates with an opposite sex coupling member on the distal end of the handpiece 28 or an extender. Due to the minimum time-constraints imposed by surgery, the coupling members are preferably rapid connect/disconnect types described below, with reference to FIGS. 9-16, showing an alternative embodiment with an extender 55.
FIGS. 9-11 illustrate two junctions on either end of the extender 55. FIG. 10 shows a partial cross section of the coupling between the handpiece 28 and the extender 55, and the extender 55 and the blade 26. Of course, it is understood that the coupling between the extender 55 and the preferred surgical blade 26 applies equally as well to a direct coupling between the blade 26 and the handpiece 28.
Each junction comprises a generally cylindrical male component 56 and a tubular female component 58 comprising a generally cylindrical recess 60 adapted to receive the male component 56. These components quickly connect by inserting the male component 56 into the female component 58 and rotating one component with respect to the other component, preferably through a relatively short rotational arc, and optimally about 90°, plus or minus 10°.
Only one junction will be referred to, as the junctions are identical. When joined, the junction produces a relatively high axial compression force, which is preferably uniformly distributed symmetrically about the contact surfaces between the two components to optimize the transfer of ultrasonic energy across the junction. Non-uniform distribution of the axial compression force about the longitudinal axis of the junction tends to decrease the efficiency of the transfer of energy across the junction, and can cause unwanted transverse motion (whipping) and may lead to premature mechanical failure.
Although FIGS. 9 through 14 illustrate the male component 56 extending in a distal direction, it is understood that the relationship of the male and female components can be reversed.
Referring to FIGS. 9-12, the male component 56 comprises at least two axially extending splines 62 spaced apart by at least two axially extending flats 64. Preferably, the-male component 56 comprises two diametrically opposed splines 62 and two diametrically opposed flats 64, alternatively positioned around the circumference of the component, as seen in FIG. 12.
Each spline 62 comprises a plurality of external threads 66 preferably configured in accordance with the American National Standard for Unified Threads ("UN"). It will be understood that other thread configurations, such as the American National Standard Acme Screw Threads ("Acme"), can be used as well. It has been found preferable, however, to employ the UN thread design instead of others, such as the Acme thread design, primarily for manufacturing ease.
Advantageously, the thread pitch and the pitch diameter of the threads 66 and the length of the splines 62 are selected to produce high axial compression between the components without structural failure. It is also preferable to select a generally standard thread for manufacturing convenience. Additionally, the threads 66 must engage to produce high axial compression with little rotation. Preferably, circumferentially, 75% of the threads 66 engage with rotation of no more than about 90° plus or minus 10°. For example, in one preferred embodiment the splines 62 comprise a series of 4-56 UNS-2A threads 66 along a length of 0.215 inches, and in another embodiment, the splines 62 comprises a series of 5-48 UNF-2A threads 66 along a length of 0.250 inches. In general, the spline 62 preferably comprises about twelve interrupted threads 66.
In general, the junction has a minimum of 45° of total engagement between the spline threads 66 to produce the high axial compression without mechanical failure. Preferably, the junction has an engagement between about 90° to about 179°, and most preferably about 173° (48% of 360°=172.8°). Thus, in a most preferred embodiment, the sum of the lengths of the threads 66 on the male component 56 measured in a circumferential direction preferably range from 90° to 179°, and more preferably equal 173°.
The circumferential length of each spline thread 66 (i.e., the circumferential width of each spline) depends upon the number of splines 62 employed. For example, in a most preferred embodiment having two splines 62, the length of the thread 66 in a single spline along the circumferential direction ranges between 45° and 89.5°, and preferably equals 86.5°.
With specific reference to FIG. 11, the female component 58 likewise comprises at least two axially extending splines 68 and at least two axially extending flats 70, disposed on the recess 60 circumference in a corresponding relationship with the flats 64 and splines 62 on the male component 56, as best seen in FIGS. 9, 15 and 16. Preferably, the female component 58 comprises two diametrically opposed splines 68 and two diametrically opposed flats 70 alternatively positioned around the circumference of the recess 60, as best seen in FIG. 15. Each spline 68 comprises a plurality of internal threads 72 configured to match and engage with the threads 66 on the male component 56.
As discussed above, the sum of the length of the threads 72 around the circumference of the recess 60 is preferably not less than about 90° and not greater than about 179°, and most preferably equal 1730. Each spline thread length depends upon the number of splines 68 employed. For example, in a most preferred embodiment having two splines 68, the threads 72 of each spline extend around the circumference of the recess 60 for at least approximately 45°, but less than approximately 89.5°, and preferably equal 86.5°.
The two splines 68 and two flats 70 alternately disposed on the interior circumference of the female component 58 recess 60 provide an axial key-way 74 for receiving the two opposing splines 62 on the male component 56, as shown in FIG. 15. The male component 56 is inserted into the recess 60 of the female component 58 and rotated to interlock the corresponding splines 62, 68 on the male and female components, as shown in FIG. 16. It is desired that minimum rotation of one component with resect to the other component will produce a junction which achieves a relatively high efficiency of energy transmission therethrough.
In general, it has been found that a high compression across the junction symmetrically distributed about its longitudinal axis optimizes energy propagation. Preferably, the thread design of the junction produces greater than about 100 pounds of axial compression force between the components with rotation of about 90°±10%. More preferably, a compression in excess of about 200 pounds will be achieved. As a result of higher compression, the ultrasonic pressure wave propagates across the junction with minimal energy loss.
It is preferred that the points of contact between the two joined surgical components be symmetric about the longitudinal axis of the male component 56 to uniformly distribute the compression force about the junction in the radial direction. As a result, the ultrasonic oscillation maintains its propagation along the longitudinal axis of the joined surgical components without deflection from that axis. If deflection occurs, the tool will tend to whip resulting in undesired heat build-up and loss of energy at the tool tip.
In this regard, the female component 58 preferably additionally comprises an annular engagement surface 76 on the proximal end thereof which contacts a corresponding annular engagement surface 78 of the male component 56. Preferably, the engagement surface 76 of the female component 58 extends radially outwardly along a plane substantially perpendicular the axis of the internal recess 60, and the engagement surface 78 of the male component 56 extends radially outward along a plane substantially perpendicular to the axis of the male component 56. Referring to FIG. 10, as the splines 62, 68, interlock, the two components draw together to force the engagement surfaces 76, 78, against each other, resulting in an axial compression force across the junction.
Preferably, the engagement surfaces 76, 78, are smoothly polished to produce a substantially liquid-tight seal between the components as the surfaces abut. In addition to optimizing energy propagation, a liquid-tight seal reduces cavitation erosion of the components at the junction and thereby extends the life of each component.
In a preferred embodiment, the female component 58 additionally comprises an axially extending, generally cylindrical counterbore 80 at the distal end of the recess 60 for receiving a generally cylindrical shank barrel 82 on the proximal end of the male component 56. The counterbore 80 and the shank barrel 82 are preferably centered with respect to the longitudinal axis of the male component 56. Preferably, the shank barrel 82 smoothly fits into the counterbore 80 to center the female component 58 with respect to the male component 56.
Advantageously, the male component 56 further comprises an undercut region 84 positioned between the engagement surface 78 and the spline so that the spline threads 66 are fully formed (i.e., no run-out region). As a result, the splines 62, 68 can be reduced in overall length, as will be understood in the art.
Referring to FIG. 11, the female component 58 preferably additionally includes a generally cylindrical pilot recess 86 for receiving a corresponding generally cylindrical tip barrel 88 at the proximal end of the male component 56. Preferably, the diameters of the pilot recess 86 and the tip barrel 88 substantially coincide with the minor diameter of the threads 72. Advantageously, the pilot recess 86 and the tip barrel 88 are centered about the longitudinal axis of the male component 56 for optimizing the concentricity of the engagement surfaces, between the components to optimize the longitudinal transfer of ultrasonic energy through the junction.
To facilitate rapid interconnection between the components, the female component 58 preferably additionally comprises an annular internal chamfer 90 and the male component 56 additionally comprises an annular tip chamfer 92. When the male component 56 is inserted into the female component 58, the chamfers 90, 92 ease the insertion by funneling the components together. Additionally, the edges of the leading spline threads 66 of the male component 56 preferably include a chamfer 94 to ease the engagement between the splines 62, 68 of the male component 56 and female component 58.
Referring to FIGS. 13-16, it is preferred that the surgical components include alignment arrows 96 etched on the exterior surface of the components to aid in the connection process. By aligning the arrows 96, the splines 62 of the male component 56 align with the key-way 74 of the female component 58, as seen in FIGS. 13 and 15. By rotating the components as shown in FIG. 14, the splines 62, 68 of the two components interlock, as shown in FIG. 16. Flat opposing surfaces 98 are provided on the exterior of all parts to receive a wrench to facilitate tightening and untightening of the junctions.
Those skilled in the art can manufacture the disclosed junction by processes known in the art. For example, the generally cylindrical male component 56 and the shank barrel 82 thereto can be cut into an end of the shank of a surgical component, such as the extender or the tool bit. The threads 66 can either be cold rolled onto the cylinder or preferably machine cut into the cylinder. The flats 64 can then be milled onto the component thereby interrupting the threads 66. Finally, the tip barrel 88 can be cut onto the distal end of the male component 56 such as by lathing operations well known in the art and the chamfers 92, 94, similarly added thereto.
The recess 60 of the female component 58 can be made by drilling the pilot hole recess 86 into the end of a surgical component. The counterbore 80 then can be milled and a portion of the pilot hole 86 tapped with the appropriate internal threads 72 by processes known in the art. The flats 70 can be milled and broached into the recess 60 thereby interrupting the threads 72 on the recess wall. Finally, the internal annular chamfer 90 can be drilled or milled to form a smooth transition from the counterbore 80 to the threaded recess 60.
Referring again to the improved ultrasonic surgical knife system 24 of FIG. 1, the control system 30 comprises an ultrasonic signal generator 100 which supplies an electric impulse to the handpiece 28, the voltage of which can be varied at different frequencies and with different waveshapes. The signal may, for example, be a pure sinusoidal wave or may be modulated with one or more other frequencies. Alternatively, the signal may be a stepped or spiked pulse. In a preferred embodiment, the ultrasonic generator 100 transmits a signal of between 20-80 kHz. More preferably, the signal is at about 60 kHz. The signal generator 100 includes a liquid crystal or other display device 102 for convenient display of selected power or frequency mode. The signal generator 100 may, for example, transmit a constant amplitude signal at a constant frequency, or alternate one or both of these parameters. The cutting power level is normally selected as a percentage of maximum cutting power. Although not illustrated in FIG. 1, an audio output indicative of mode changes and present mode is preferably included which is responsive to the ultrasonic signal generator output 100.
The signal transmits through a multi-conductor shielded cable 32, for safety and durability, to the handpiece 28 which imparts ultrasonic, generally longitudinal, movement to the surgical blade 26. As will be described more fully later, high-efficiency piezo-ceramic washers 164 (FIG. 7) which generate the ultrasonic vibrations within the handpiece 28 (FIG. 7), allow a thin high-flex cable 32 to be used. The electronic signals are a lower than usual voltage not requiring a thick cable, which gives the surgeon added freedom to maneuver the handpiece 28. A high quality auto-clavable connector 106 couples the cable 32 to the signal generator 100.
Referring to FIGS. 6 and 7, the outer protective cover of the handpiece 28 generally comprises a nose cone 108, a cylindrical casing 110 and an end cap 112 of durable stainless steel or other corrosion resistant material. Advantageously, the protective cover is stainless steel and the sections are sealed hermetically, to protect the internal components from the corrosive fluids of surgery and temperatures in a steam autoclave. The handpiece 28 is preferably about 6 inches long and 1/2 inch in diameter.
The distal end of the handpiece 28 is the end proximate the blade 26, and the proximal end is the end proximate the cable 32. An acoustic horn 114 transmits standing pressure waves from the piezo-ceramic washers 164 to the blade 26. As used herein, the term "horn" means the component of the handpiece 28 that functions both as the acoustical concentrator, as well as the front end of the transducer. A central bolt 116 extends substantially the length of the handpiece 28 and provides a central coupling member rigidly joining the internal elements, as seen in cross section in FIG. 8. A heel slug 118 includes internal threads 120 for engagement with external threads 122 of the central bolt 116. The horn 114 also includes internal threads 124 which couple with external threads 126 on the central bolt 116. The piezo-ceramic washers 164 include a central bore 128 sized to fit over the external threads 122 of the central bolt 116. The horn 114 and heel slug 118 compress the washers 164 therebetween via longitudinal movement along the central bolt threads 122, 126. The piezo-ceramic washers 164, in combination with portions of both the horn 114 and heel slug 118, comprise an electromechanical transducer, converting electrical energy to mechanical pressure waves.
A rear annular bulkhead 130 is silver soldered to the rear of the central bolt 116 and supports the outer casing 110 at the proximal end of the handpiece 28. The interface between the outer circumference of the bulkhead 130 and cylindrical casing 110 provides a hermetic seal and a solid ground connection. Additionally, an O-ring 132 disposed between a front flange of the horn 114 and the nose cone 108 provides a fluid-tight interface. The piezo-ceramic washers 164, and all other internal components shown in FIG. 8 between the seals 130, 132, are thus enclosed within the cylindrical casing in a fluid-tight manner allowing the handpiece 28 to be immersed in a steam autoclave without harm.
The horn 114 comprises generally three sections, a cross-sectionally enlarged section 134, a transition section 136 and a narrow section 138 (see FIG. 7). The narrow section 138 at the distal portion of the horn 114 includes a female junction component 140 adapted to receive a male junction component (not shown) of a surgical blade 26, or other surgical component. The mechanical energy which is produced by the piezo-ceramic washers 164 propagates along the horn 114 and amplifies at the transition section 136.
As is well known in the art, decreasing the cross section of a structure transmitting longitudinal pressure waves increases the stroke, i.e., produces a positive gain in longitudinal oscillation. A stepped horn produces a gain which is approximately equivalent to the ratio of the larger area to the smaller area of the horn 114, while a more gradual change in diameter produces a gain equivalent only to the ratio of the diameters. Moreover, the location of the cross-sectional changes along the structure affects the degree of gain produced, as described below.
Thus, by adjusting the change in cross section of the horn 114, the shape of the dimensional transition, and the location of the dimensional transition, a specific gain may be obtained to tailor the stroke of the blade 26 for optimum performance. Preferably the gain achieved by the transition section 136 works in conjunction with a transition section of the blade 26 to produce an optimum longitudinal amplitude at the blade tip. The longitudinal amplitude of the blade 26 is preferably between 0.00025 and 0.004 inches peak-to-peak, and more preferably 0.0025 inches peak-to-peak at 60 kHz, reducing the chance of material failure and controlling the energy for a fixed thermal footprint.
The piezo-ceramic washers 164 remain in a stationary, compressed state between the horn 114 and the heel slug 118 and thus occupies a node of a standing wave created along the heel slug-washer-horn combination. At the nodes of vibration there is no motion but maximum stress. Nodes are spaced exactly one half wavelength apart and thus from the piezo-ceramic washers 164, nodes occur every half wavelength down the horn 114 (e.g., front transition 136).
Anti-nodes are points of absolute maximum amplitude, experience the largest longitudinal movement and the least stress, and are located 1/4 wavelength from each node. The closer the location of the cross-sectional change 136 to a node of vibration, the greater the gain realized, because the ultrasonic energy is stored as internal potential at these points, as opposed to kinetic energy at the anti-nodes.
The elongated, cylindrical horn 114 preferably includes one step concentrator to tailor the gain to cause a preferred blade 26 to function optimally; i.e., to preferably stroke from 0.00025 to 0.004 inches, peak-to-peak, and more preferably at 0.0025 inches, peak-to-peak at 60 kHz. The small stroke advantageously reduces internal stresses in the horn 114 and blade 26 and thus reduces the chance of material failure.
The proximal end of the horn 114 defines an aperture leading to a central cylindrical cavity 142 sized to receive the distal end of the central bolt 116. The cavity 142 includes internal threads 124 which mate with external threads 126 on the central bolt 116. The cavity 142 extends axially in the distal direction, past the internal threads 124, and ends at a chamfered portion 144. The central bolt 116 includes opposing axial flats 119 for a wrench-assisted insertion into the cavity 142.
The majority of the enlarged section 134 comprises a solid cylinder to optimize ultrasonic energy propagation. The horn 114 is thus preferably constructed of a high strength material which efficiently propagates ultrasonic energy. More preferably, the horn 114 is constructed of titanium. The enlarged section 134 desirably has a length equal to approximately a half wavelength, with an anti-node positioned generally at the longitudinal center of the enlarged section 134. In this manner, the front half of the enlarged section 134 forms part of the acoustical concentrator, while the back half forms the front end of the transducer.
The distal portion of the horn 114 includes a female coupling portion 140, as described above. The distal portion of the horn 114 additionally comprises a central lumen 146 extending proximally from the female coupling 140 preferably throughout the length of the narrow section 138. The lumen 146 extends slightly past the transition section 136. The lumen 146 assists in amplifying the ultrasonic energy propagated down the horn 114. As described previously, pressure waves crossing a reduction in the cross-sectional area of a structure experience a gain. The lumen 146 defines a tubular section at the distal portion of the horn 114, further reducing the cross-sectional area of the material of the narrow section 138.
In an alternative embodiment, as illustrated in FIG. 8a, the lumen 146' extends entirely through the handpiece 28'. For ease of understanding, like reference numerals with a prime mark (') have been used to indicate like parts between the two embodiments. The lumen 146' extends coaxially with the longitudinal axis of the horn 114' and the central bolt 116' and through the end cap 112'. The end cap 112' desirably is adapted to receive a tube coupling to couple the lumen 146' with a fluid tubing. It also is contemplated that the blade/tool/sharps bit coupled to the ultrasonic handpiece 28' likewise would include an internal lumen, which would communicate with the central lumen 146' of the handpiece 28' when coupled to the handpiece distal coupling 140'. In this manner, the central lumen 146' may be used either for irrigation or aspiration.
With reference back to FIG. 8, the overall length of the "horn" 114 for 60 kHz is preferably less than about 2.5 inches, and more preferably the length of the horn 114 is 2.40 inches. The horn 114 is sized so that the front coupling junction 140 experiences a minimum of stress from being positioned close to an anti-node of vibration. The transition section 136 is desirably 10:1 or greater, and more preferably less than 0.75 of an inches from the farthest front portion of the horn 114, and more desirably the transition section is 0.600 inches from the front of the horn 114. The enlarged section 134 has a diameter of no more than 1/2 inch to fit comfortably in the hand of a surgeon, and more preferably the diameter of the enlarged section is 0.425 inch. Advantageously, the inside diameter of lumen 146 in the narrow section 138 of the horn 114 is less than about 0.1 inches to provide a sufficient wall thickness of the frontal section to minimize stress failure. More preferably, the diameter of the lumen 146 is about 0.07 inches. The outer diameter of the narrow section 138 of the horn 114 is preferably no more than about 0.25 inches, and more preferably the outer diameter of the narrow section is 0.125 inches. Advantageously, an exterior annular flange 150 at a position proximal to the transition section 136 provides a shoulder against which the O-ring 132 abuts. The nose cone 108 of the outer cover compresses the O-ring 132 rearward against the flange 150 in a semi-rigid manner, and in a fluid tight manner between the inside diameter of the tubing 110 and the outside diameter of the horn 114.
Referring to the cross-sectional view of FIG. 8, the length of the central bolt 116 is shown. The central bolt 116 comprises a solid, generally cylindrical metallic rod with a chamfer 152 at the distal end of a distal cylindrical portion 154. The distal cylinder 154 fits in the distal cavity 142 of the horn 114, as previously described. The distal chamfer 152 bottoms out at the internal chamfer 144, providing a flush stop for the central bolt-horn interface, thus more efficiently transmitting ultrasonic energy.
The distal thread region 126 separates the cylindrical portion 154 from a middle cylindrical region 156. The threads 126 are preferably 0.2 inches from the front of the central bolt 116, and the proximal section of threads 122 is located 1.4 inches further rearward. Preferably, the threads 126 are 10-56 UNS-2A type threads, and configure to meet with similar internal threads 124 of the horn 114.
The middle cylindrical portion 156 extends through the central bore 128 of the piezo-ceramic washers 164. The washers 164 slide along the middle portion 156 to abut the horn 114 adjacent the distal threads 126 of the central bolt 116. The distal axial face of the washers 164 and proximal axial face of the horn 114 lie flush against a thin annular spacer 170 therebetween to optimize transmission of ultrasonic vibrational energy.
The proximal thread region 122 separates the middle region 156 from a cylindrical heel slug receiving portion 158. The bolt 116 terminates in a reduced diameter isolation region 160 and a rear bulk head support shaft 162. The rear thread 122 region is adapted to receive the heel slug 118. As stated previously, the heel slug 118 threads onto the central bolt 116, compressing the piezo-ceramic washers 164 against the horn 114. The rear-most portion of the heel slug 118 terminates at the transition of the central bolt 116 to the isolation region 160. The large change in diameter between the heel slug 118 and the isolation region 160 causes the isolation region 160 to tend to vibrate at its own natural frequency, interfering with sound propagation at the fundamental frequency in this direction. The ratio between the cross-sectional areas of the heel slug 118 to the isolation region 160 desirably is 10:1 or greater, and more preferably is 25:1 or greater. This abrupt cross-sectional area change in the transducer configuration causes less than 5 percent loading on the overall handpiece 28 to essentially isolate the handpiece 28 from the produced vibrations. In this manner, little ultrasonic energy is propagated rearward.
In addition, the additional 1/4 wavelength length of the bulk head support shaft 162 on one side, and the isolation region 160 of a length less than 1/4 wavelength--preferably about 1/16 to about 1/8 wavelength--on the other side forces the bulkhead 130 to be an artificial or virtual node (a node and an anti-node separated by less than λ/4). The 1/4 wavelength length of the bulk head support shaft 162 thus functions as a terminal resonator which is desirably tuned to reflect vibrations in phase with the vibrations propagating from the distal side of the piezo-ceramic washers 164 down the horn 114 and the attachments thereto (e.g., extender(s), tool/blade/sharp bit, etc.). This reinforces the stability of the bulkhead 130 location and minimizes any loading of the handpiece when the bulk head 130 is silver soldered to the central bolt 116 and the inside diameter of the tube 110.
The combination of the cross-sectional area ratio between the heel slug 118 and the isolation region 160 of the central bolt 116, the location of this area reduction at an anti-node, the one-quarter wavelength length of the bulk head support shaft 162, and the overall configuration provides good acoustical isolation (i.e., 5 percent or less transmission), good electrical conductivity between the components of the handpiece for a good ground path, and good mechanical stability (i.e., torque resistance) to prevent the horn 114 from rotating when coupling a tool/blade/sharp to the distal coupling end 140. In addition, where the central lumen 146' extends through the entire handpiece 28' (see FIG. 8a), this integral construction provides a uniform, continuous, low-resistance flow path between the proximal and distal ends of the handpiece 28'.
The material of the thin annular washers 164 is a piezo-ceramic compound of lead-titanate and zirconium titanate. Advantageously, two to eight washers 164 may be utilized, depending on the strength of vibration desired, and preferably there are two washers 164. These washers 164 include central bores 128 to fit over the middle cylindrical region 156 of the central bolt 116. The central bore 128 passes over the rear threads 122, and an insulating material 168 is wrapped around the central region 156 to fill the annular void formed and hold the washers centered on the bolt 116.
Two very thin annular spacers 170 separate the piezo-ceramic washers 164 from the horn 114 and heel slug 118, and distribute the compressive forces evenly. A layer of electrically insulating material 166 covers the washers 164 and isolates them from the outer casing 110 of the handpiece 28. An air gap 172 between the insulating layer 166 and the casing 110 provides effective thermal and acoustical isolation from the outer casing. Preferably, the air gap 172 is approximately 0.017 inches, which has been found to reduce the radiation of internal heat to the outer casing 110. A "hot" electrode 174a and a ground electrode 174b connect to the appropriate piezo-ceramic washer 164 to effectuate mechanical vibrations. The electrodes 174 extend proximally from the piezo-ceramic washers 164 within the air gap 172. The "hot" electrode 174a passes through a small passage 176 in the bulkhead 130 and from there to the rear end cap 112 and a "hot" circuit of the connector 106 of the cable 32. The ground electrode 174b connects directly to the bulkhead 130 which is in electrical contact with the ground circuit of the connector 106.
As is well known in the art, piezo-ceramic materials produce mechanical vibrations upon excitation by an applied voltage. This mechanical vibration is caused by changes in the internal structure when under the influence of the external voltage. The piezo-ceramic washers 164 are held under compression between the horn 114 and the heel slug 118. Preferably, the compression of the piezo-ceramic washers 164 is between 500 and 5000 psi, and most preferably about 1500 psi.
Aligning the washers so that the positive side of one abuts the positive side of another causes the washers to oppose each other's motion, and in effect double their amplitude vibrations. Such piezo-ceramic washers 164 held in compression are restricted from thickening; their internal stresses are transmitted to the surrounding compressive members in the form of pressure waves. The preferred piezo-ceramic configuration is a "Langevin sandwich" design.
As the waves propagate along the horn 114 and heel slug 118, the potential strain energy converts to kinetic energy and back, due to the wave-like nature of the signal. The heel slug 118 and adjacent isolation region of the central bolt 116 tend to reflect the vibratory motion with some losses (damping) while the excellent energy transmittal properties of the titanium horn 114 propagates the vibrations directly to the blade 26 with minimal losses. The washers are thus aligned and compressed between the heel slug 118 and the transducer/horn 114. The compression of the piezo-ceramic washers 164 results in standing pressure waves propagated down the horn 114 and reflected back.
As stated previously, the piezo-ceramic washers 164 preferably occupy a node of vibration and other nodes appear approximately one-half wavelength later (if the material or cross section does not change) and every half wavelength subsequently. Anti-nodes are located approximately 1/4 wavelength between the nodes and experience the largest longitudinal movement and the least stress. At 60 kilohertz, each 1/2 wavelength equals approximately 1.6 inches in the preferred titanium horn 114. The horn 114 is machined so that the transition region 136 desirably occupies a node. In addition, the coupling region 140 at the front portion of the horn 114 is preferably placed close to an anti-node to reduce the stress of the coupling. Thus, locations of the transition region 136 and the front coupling region 140 are multiples or fractions of the preferred 1/2 wavelength of 1.6 inches.
The heel slug 118 is preferably fabricated from tool steel or stainless steel. A central bore 178 extends through the heel slug 118 and includes internal threads 120 at the rear (proximal) end. The heel slug 118 also comprises two opposing wrench flats 180 at the rear end.
The parameters of the blade 26 may be altered, or the ultrasonic signal may be varied, to customize the type and character of incision desired. As stated previously, higher frequency surgical knives tend to propagate energy shorter distances into surrounding tissue and thus propagate thermal effects to less depth. At times though, some thermal effect on the tissue is desirable, especially when dry cutting. Modulating a high frequency signal with a substantially lower carrier frequency allows the surgeon to nominally retain the advantageous features provided at high frequencies (hemostasis) while periodically applying a lower frequency to effectuate some increased degree of cavitation. At lower frequencies there is more drag, and thus more feel and tissue differentiation. Adjusting the modulating frequency to decrease the periods of high frequency results in more feel, and thus the surgeon may selectably alter the response of the surgical blade 26 to different types of tissue. In a preferred embodiment, the surgical blade 26 of the present invention is vibrated at 60 kHz with a modulating frequency of between 10 and 10,000 Hz, and a preferred frequency of 600 Hz. This is a concession to ergonomics only. Loud, audible frequencies above 600 Hz are more irritating; otherwise, the modulation frequencies of choice to maximize cavitation would be about 5 to about 25 kHz, with about 10 to about 15 kHz the more preferred and about 10 kHz the most preferred.
Referring now to FIGS. 17 and 18, a split chuck 182 connects with an extender which couples with the handpiece 28 in an alternate form of the present invention. The split chuck 182 is shown in greater detail in FIG. 18. The split chuck 182 includes a forward slot 184 which receives a flat surgical cutting blade 186. The blade 186 is placed within the slot 184 and a collet 188 threads over the chuck 182 to tighten the blade within the chuck. Chuck 182 is provided with opposing wrench flats 190 to tighten the chuck in the handpiece 28, or an extender, with a wrench.
Advantageously, the extenders allow the handpiece of the present invention to be remain external to the body while the blade extends within a catheter, trocar sheath, or endoscope lumen for endoscopically-assisted surgery. The extenders possess excellent sonic transmission properties with minimal losses at the interfaces. Additionally, the rapid connect/disconnect coupling feature allows rapid changing of extenders, blades and chucks. Preferably, the present invention may be used endoscopically with a 4 millimeter catheter opening. Preferably, extenders allow surgery at a depth of as much as 24 inches from the handpiece 28.
Referring to FIG. 19, there is disclosed a blade carrier 195 in accordance with a further aspect of the present invention. Blade carrier 195 facilitates handling of the ultrasonic surgical blade in a sterile environment prior to installation on an ultrasonic handpiece. In addition, the use of the blade carrier 195 minimizes the risk of inadvertent blade sticks during handling and installation, removal, and disposal of the blade.
Blade carrier 195 generally comprises a blade housing having a blade connector end 196, and a blade tip end 198. The overall length of the blade carrier 195 is preferably about 2.5 inches. Blade cavity 200 is disposed therebetween, for receiving the sharp end of the blade. The connection end of the blade, which may be threaded or provided with other quick connection/disconnection means previously disclosed, projects from the blade cavity 200 axially through the open channel 204 and out the open end 210. The open channel 204 is provided with a pair of opposing surfaces 206 and 208 for frictionally engaging the wrench flats on the connector end of a blade, as has been previously described. Referring to FIG. 20, opposing surfaces 206 and 208 can be more clearly seen. In a preferred embodiment, projections 209 and 211 are additionally provided for retaining the connection end of the blade within the open channel 204.
The blade cavity 200 is a shallow flat or rounded bottomed recess, having a length dimension 201 of about 1.5 inches and a width dimension 202 of about 0.50 sufficient to accommodate a variety of blade configurations. In general, blades contemplated to be utilized with the ultrasonic knife in accordance with the present invention have a cutting edge length within the range of from about 0.5 inches to about 1.5 inches. In addition, the width along the plane of the blade varies within the range of from about 0.030 inches to about 0.40 inches for most applications. Specialty blades, for unique applications, may vary considerably from the foregoing ranges.
The blade carrier 195 is provided at its blade tip end 198 with a knob 212. Knob 212 comprises a generally cylindrical body, preferably having a diameter of about 0.50 inches, and length of about 0.5 inches, having friction enhancing structures such as knurling on the radially exterior wall thereof. The axis of knob 212 is aligned with the axis extending through the open channel 204. In this manner, the clinician can spin the knob 212 between two fingers to threadably engage the connector on the knife with the corresponding connector on the ultrasonic handpiece or extender as discussed below.
The blade carrier 195 is preferably also provided with a pair of opposing wings 214 and 216 to provide leverage for rotating the blade carrier to tighten the connection between the blade and the ultrasonic knife, extender, or handpiece. Preferably, the overall width of the carrier through the wings 214, 216 is about 1.2 inches. As has been previously discussed, the typical connection between the knife tip and the handpiece is a rotatably engageable connection. For example, with the quick connect and disconnect embodiment previously disclosed, the blade is inserted onto the handpiece or the connector by an axial advancement and then the blade is tightened by rotating the blade through an angle of approximately 90°. In an alternate embodiment, the blade is simply threaded onto the handpiece or connector by rotating through a series of complete revolutions. In either embodiment, the blade must be appropriately rotationally tightened into the handpiece or extender.
For this purpose, the opposing surfaces 206 and 208 and a hinge region 207 therebetween are preferably molded from a material having a suitable resilience that the rotation of the blade carrier 195 will rotate the blade contained therein until the blade is suitably tightened against the handpiece or extender. Further rotation of the blade carrier 195 will cause the opposing surfaces 206 and 208 to spread slightly, permitting relative rotation between the blade carrier 195 and the blade contained therein. The clinician simply rotates the blade carrier 195 until the assembly "snaps" or starts to cam over. In this manner, a predetermined predictable and repeatable amount of torque within the range of from about 0.50 to from about 80.0 inch-lbs., preferably about 3.0 inch-lbs., can be applied during installation of the blade. Wings 214 and 216 provide both a friction surface and leverage for the clinician to use to rotate the blade carrier 195 during installation. Following sufficient tightening of the blade, the blade carrier 195 is simply pulled laterally away from the tip of the blade and discarded, or saved, to be reinstalled at the end of surgery and then discarded with "sharps."
The blade carrier 195 may be constructed in any of a variety of ways which will be well known to one of skill in the art. For example, the entire blade carrier may be integrally molded such as by injection molding, thermo forming or vacuum forming of a pre-formed sheet of plastic. Alternatively, the blade carrier 195 can be fabricated from premolded component parts, such as by premolding the blade connection end 196 and the knob 212. The main body of the blade carrier 195 is preferably stamped or molded from a sheet of plastic, and may be thereafter secured to the blade connector end 196 and knob 212 using thermal bonding, solvent bonding, ultrasonic welding or other techniques known in the art.
Alternatively, some or all of the blade carrier 195 can be formed from an appropriate metal sheet, and preferably thereafter provided with an appropriate plastic coating. In general, the construction of the blade carrier 195 is of appropriate materials that will permit sterilization of the assembly of the blade carrier 195 with a blade therein. The blade carrier 195 and blade are thereafter introduced into a sealed packet or pouch for sterilization and shipment.
Problems associated with ultrasonic surgery can be generally classed in two categories. The first category would be the effect on the living tissue on either side of the cut. Excess heat generation, tearing of tissue or inadvertent cutting of nearby anatomical structures are all problematic to ultrasonic surgery. The second category of problems is a relative lack of operator comfort, flexibility and feedback.
In ultrasonic surgery, the knife blade may oscillate at anywhere within the range of from about 1 kHz to about 100 kHz. Typically, however, frequencies of lower than about 23 kHz are not used because they are within the audio range. In addition, frequencies in excess of about 50 or 60 Khz produce an increased amount of localized heating along the tissue contacting sides of the blades.
For relatively low frequencies, e.g., below about 20 or 30 kHz, high carbon steel or stainless steel is an appropriate construction material for the ultrasonic knife blades of the present invention. However, frequencies in excess of about 30 kHz, which are considered relatively high, are preferably used in conjunction with ultrasonic knife blades made from or coated with titanium, aluminum, or other metals or alloys which will transmit ultrasonic energy efficiently, with less internal heating.
Approximately 50% of the heat is produced from sound absorption in the surrounding tissue, 25% produced from internal frictional heating of the blade itself, and 25% produced by friction of the blade and tissue. At times, heat is preferred if a hemostatic nature of cut is desired. Hemostasis is the coagulation or formation of white gelatinous substance at the sides of the cut, and is commonly referred to as "bloodless surgery." At temperatures above 65° C. (149° F.), proteins in human tissue are denatured, producing coagulation. Although in some instances hemostasis is desirable, the increased temperatures involved in ultrasonic surgery potentially increase the likelihood of denaturing protein in tissue and can produce localized thermal damage, or necrosis, to the tissue surrounding the incision.
As mentioned above, sound absorption into the surrounding tissue comprises the majority of heat generation in ultrasonic surgery. Ultrasonic surgical instruments propagate pressure waves down the blade and into the surrounding tissue. At the interface of the blade material and the tissue, there is an impedance mismatch, causing the sound waves to dampen or "deaden" as they attempt to propagate further into the tissue. The energy absorbed by the damping characteristics of the tissue is converted to heat. Preferably, the ultrasonic energy does not propagate far into the tissue, to limit the effect the heat produces. It is well known that higher frequency, shorter wavelength signals dissipate faster and in shorter distances in elastic material, such as biological tissue, and therefore would appear to be favorable to limit the depth of thermal effects.
A smaller percentage of the total heat produced in an ultrasonic surgical procedure occurs from internal frictional heating of the knife blade. In general, the construction material of the surgical blade determines the level of internal friction, and potentially damaging heat. Stainless steel, for example, is a relatively inefficient conductor of acoustic energy, and a lot of internal friction results. Stainless steel used at frequencies above about 20 kHz can get very hot. The titanium used for the present surgical blade 26 on the other hand is an excellent conductor of acoustic energy and may be used at the highest frequency contemplated (60 kHz) with a minimum heat buildup, especially if caused to start and stop vibrating intermittently. However, as stated previously, some heating may be necessary if bloodless surgery is desired.
Sharp surgical blades oscillating at ultrasonic frequencies can tend to fall through living tissue, much like a hot knife through butter. Conversely, a duller knife, or one which has low or no ultrasonic assistance, requires a greater amount of force, and more subsequent tearing of the tissue occurs. Such slower cutting, which may result in more scarring, may be desirable when performing surgery proximate vital organs so that the surgeon can feel the blade advancing through the tissue and more carefully continue. Ultimately, ultrasonic surgery results in the breaking of living tissue bonds which are of varying strengths. The present invention addresses this issue and provides the surgeon with multitudes of configurations of blades, depending on the type of cut desired.
The second category of problems associated with ultrasonic surgical tools are those relating to the lack of operator control of, and poor ergonomics of, the instruments. First, there has been a lack of understanding of the tactile feedback necessary to carefully resect different types of living tissues with one particular knife. As discussed above, a very sharp knife might be desirable, for instance in cosmetic surgery, but provide the surgeon with little or no feedback of the type of tissue the knife is cutting through. Conversely, a knife with lots of drag may provide feedback, but may have a substantial reduction in the quality of cut desired. Additionally, the amount of feedback desired is a subjective determination by the individual surgeon. A more experienced surgeon would tend to require less feedback than a novice. The amount of heat generated is another critical control parameter, previously addressed by simply altering the thermal footprint of the blade. Another phenomenon associated with ultrasonic surgery is the formation of cavitation bubbles in the region proximate the surgical blade. Control of the amount of cutting from mechanical shearing of the tissue bonds, as opposed to that from cavitation-assisted cutting, has not previously been addressed.
Cavitation occurs when the local pressure in a fluid decreases below the vapor pressure of that fluid. Local voids or vacuum pockets, in effect, are created which then tend to implode violently upon an increase in pressure. objects moving rapidly through a fluid can induce such cavitation in their wakes by abrupt changes in fluidic pressure, as is known in the art of fluid dynamics. Ultrasonically oscillating surgical blades have a tendency to cavitate in the bodily fluids surrounding an incision. In addition, normal saline or other fluids can be supplied to a surgical site to enhance normal cavitation. The saline or irrigation solution desirably includes a biocompatible element to introduce micro-weaknesses in the solution. Carbonate salts, dissolved gases, and other compounds or particulates can be suspended or dispersed in the solution as the biocompatible element. The presence of such elements lowers the energy threshold requirements for effective cavitation. For instance, an effective power cavitation threshold can be reached at 40 kHz with a 0.0012-inch peak-to-peak stroke length in a well-filtered, degassed irrigation solution. With an enhanced salt solution (i.e. , an increased amount of biocompatible carbonate salts) , the power threshold can be lowered to produce a 0.0006-inch peak-to-peak stroke length while obtaining effective cavitation. At lower frequencies, e.g., below about 20 to 30 kHz, ultrasonic knives tend to create a cavitation emulsification layer which nominally provides better lubrication for the knife blade, and tends to minimize the effects of heat transfer to the surrounding tissue.
The amount of cavitation plays a major role in the characteristics of the final cut. The implosion of cavitation "bubbles" can be detrimental to the micro-surface of the surgical instrument, but also can assist the cutting action by breaking tissue bonds at the same time. The physics of the formation of cavitation bubbles is such that the temperature at their surface can reach 5000° F. This intense but highly localized energy is converted to the kinetic energy of a shock wave upon implosion. The result is that the knife tends to "blow through" the tissue and the energy which would have been converted to thermal transfer to the surrounding tissue is used for cutting. In some instances cavitation primarily, in conjunction with some hemostatic action, is a preferred cutting method.
The present invention addresses the aforementioned problems associated with ultrasonic surgery in terms of varying the characteristics of the incision and providing the surgeon with proper feedback and flexibility of use. The surgeon has a wide range of blade configurations and operating modes to best perform a particular procedure to his or her preference. The tactile feedback and cutting options available with the present ultrasonic surgical blade are a major improvement over prior instruments.
The amount of heat generated and propagated into the surrounding tissue is controlled by the shape of the preferred blade 26. The area of the contact surfaces 38 can be widened to increase the heat generation from sonic and conductive energy transfer. This is desirable in regions containing numerous blood vessels to induce hemostasis. Similarly, the angle of the tapers 40,42 affects the magnitude of thermal footprint of the blade 26. A large portion of the cross-section of the blade 26 in contact with the tissue being cut is removed by the formation of the relief 36. These parameters can be cohesively managed to provide a wide range of incision characteristics. For example, cosmetic surgery requires the sharpest blade with minimal thermal damage to minimize scarring. Alternatively, a sharp blade with more heat generation may require a similar blade tip with more contact surface and less relief in the central portion. The hollow-ground blade edge also brings these two effects closer together to provide a very sharp knife with substantial heat generation directly behind the cutting edge for increased hemostatic tissue activity. The various shapes of the current blade 26 contemplate an infinite number of functional combinations.
Another factor in heat generation is the surface texture of the blade 26 surfaces. Smoother surfaces result in less frictional resistance than rougher ones. Roughening the surface texture of the contact surfaces 38, while highly polishing the tapers 40, 42 and relief portions 36, results in some increase in heat generation, which can be customized for the type of tissue involved. Surface textures can be modified by either polishing an existing surface or roughening the existing surface of the blade. Minimal surface friction will be incurred in a blade having a highly polished surface such as an RMS of 1 or 2. RMS, or root-mean-square, is a proportionate term generally referring to the statistical average of the sizes of irregularities. Practically, however, polishes of this degree are difficult to produce on the construction material utilized for surgical blades. Relatively rough areas of the surgical blades disclosed herein are contemplated to have an RMS of about 63. This level of roughening can be accomplished by processing the knife blade with glass beading, chemical etching, or other techniques which will be known to one of skill in the art. Preferably, a random sized distribution of bumps or pockets within the range of from about 20 to about 400 micron are utilized when operating in an ultrasonic frequency range of about 20 kHz. The bumps or pockets are preferably rounded or hemispherical in shape, to improve longevity under ultrasonic vibration conditions, and to minimize fragmentation and leaving parent material behind.
It is understood that the size of the irregularities or micro cavities in the cutting edge surface can be decreased in size if the knife is intended for operation in a higher frequency range. For instance, if operated in an ultrasonic frequency range of about 40 kHz, the irregularities can have sizes ranging between about 10 to about 200 microns, and if operated in a frequency range of about 60 kHz, the irregularities can have sizes ranging between about 5 to about 100 microns. At higher frequencies (e.g., 100 kHz), the irregularities sizes can be smaller (e.g., 1.0 micron or less).
A further parameter influencing the amount of thermal generation is the frequency and mode of oscillations. The control system 30 of the present invention allows for complete flexibility for the surgeon to alter the oscillation character. As is known, a higher frequency surgical blade tends to transfer less thermal energy to a greater depth via sound propagation to the surrounding tissue but has higher internal heat of blade and at the interface of blade and tissue. The control system 30 provides a means for modulating such an advantageous frequency with lower frequencies to provide some drag, or tactile feedback, to the surgeon, and increase effective cavitation.
Other combinations of frequencies and waveforms can be generated by the control system 30 to tailor the oscillations of the blade 26 to the particular surgical environment. For instance, as discussed above, both the amplitude and the frequency of a signal driving the blade can be modulated to produce effective heating and cavitation cutting. By way of an example, the amplitude of a base signal (e.g., 60 kHz) can be modulated between about 5% and about 100% of its peak amplitude. That is, the control system 30 steps the amplitude of the base signal between about 5% and about 100% of the peak amplitude. (As noted above, the peak amplitude of the driving signal is selected to produce the desired stroke length of the blade). The period between modulations desirably can be as low as 600 Hz and as high as 15 kHz. During periods of peak amplitude, the base signal also can be modulated with a high frequency (e.g., 90 kHz). As discussed above, the modulation of the base signal with a high frequency provides excellent heating effects at the knife/tissue interface for tissue hemostatic activity, while amplitude modulation of the base signal at a low frequency increases cavitation formation to assist cutting.
The present invention also identifies and presents solutions to the problems of feedback and individual surgeon needs. The advantageous shape of the serrations of the present blade 26 transfer resistance forces more efficiently to the hand of the surgeon. Providing surfaces perpendicularly vectored to the tissue means that more resistance is encountered from an increase in the pressure of cut. Reducing the stroke of the blade and spacing the teeth 46 of the blade 26 so that at least two teeth 46 encounter a specific tissue bond on each stroke reduces the internal stresses on the knife as well as the magnitude of vibrations of the handpiece, while ensuring a clean and effective cut.
Another benefit of the ultrasonic surgical system 24 of the present invention is the ability to manage the amount of cavitation generated. Cavitation minimizes thermal energy penetration into the surrounding tissue by converting the transient shock wave energy into a cutting action. The dynamic feedback associated with cavitation-assisted cutting provides enhanced tissue differentiation, as the stronger, more elastic, bonds holding such anatomical structures as blood vessels together require more energy to break than does the surrounding tissue. The feedback from cavitation cutting, in effect, increases the surgeon's feel for changes in drag felt when cutting from weak to tough tissue, as opposed to the coarse changes in feedback from simply mechanically shearing the same tissue layers.
Control of the various parameters of the present invention allows the surgeon to select the amount of cavitation produced. The primary factor for changing the amount of cavitation at a fixed frequency and a uniform saline solution is the surface texture of the blade 26 surfaces. Smoother surfaces result in less frictional resistance than rougher ones and thus less disturbance of the fluid boundary layer next to the blade. Roughening the surface texture of a blade results in wakes and the subsequent formation of additional cavitation bubbles. In general, the larger the surface irregularity, the larger and more energetic bubbles are formed. The discussion of surface roughness of the blade 26 above in terms of preferred frictional heating applies to cavitation as well. Relatively rough areas of the surgical blades disclosed herein to induce a substantial amount of cavitation are contemplated to have an RMS of about 63.
Cavitation can also be increased by increasing the angle and width of the blade cross-section which contacts the tissue. The shape and surface texture of the teeth of the present blade can be altered to increase or decrease cavitation or, in effect, manage the percentage of cutting due to cavitation. For instance, as mentioned above, a blade edge having a hollow-ground first taper and a tooth depth 46a which extends over the full radius of the curved surface of the first taper will increase the amount of cavitation.
Cavitation is highly dependent on the frequency of oscillation. Lower frequencies, in general, produce more cavitation as slower moving blades tend to form larger bubbles; there is approximately nine times more cavitation energy at 20 kHz than at 60 kHz for the same stroke (peak to peak motion). The present invention advantageously can be configured to increase the amount of cavitation at higher frequencies. In addition to altering the shape and texture of the blade, the blade 26 oscillation may be started and stopped with gated pulses to induce more cavitation. A blade operating at 60 kHz to take advantage of the reduced thermal penetration, for example, may be gated to cause a greater number of larger cavitation bubbles to form during the slow-down and start-up periods without increasing the thermal effect on the surrounding tissue. The depth of thermal penetration is desirably limited to 1 mm into the sides and bottom of an incision. Advantageously, the gated pulses would be applied directly out of phase from the original frequency to rapidly dampen out the natural vibration of the oscillating blade 26 and horn 114. The gated pulse would preferably only reduce the vibrational amplitude to 5-10% of the original and thus leave the blade and horn "singing". The start up pulse would then be applied directly in synchronous phase with the small residual vibrations, to more quickly bring the blade 26 and horn 114 back to the original amplitude.
Another primary advantage with the surgical knife of the present invention is seen in its ability to cut through a wide range of materials with a maximum of control. Coordinating the blade 26 configuration, ultrasonic signal shape and surgical technique permit an infinite number of applications. For example, in the area of tissue resection, straight cutting or dry cutting with hemostasis, or cavitation-assisted cold-cutting are all within the realm of uses for the present invention. Similarly, other more durable materials may be cut with the present blade 26. Osseous matter can be sawed easily and with minimal necrosis. Plastics and cements, such as PMMA used in affixing prosthetic devices within body cavities, are also rapidly cut through with the proper toothed blade 26 and at the proper frequency. Another possible use for the present invention is for delaminating hi-tech composites, the vibrations serving to break the chemical bonds of the laminates.
A further configuration possible with the blade 26 of the present invention is machining more than one shaped edge around the blade. This time-saving feature would provide a surgeon with essentially two or more tools in one. Normally, a surgical incision passes through many different types of tissue, requiring different techniques or a new blade altogether. The time spent switching a blade can be extremely costly to the patient. The present surgical blade 26 may have one side shaped and finished for rapid, sharp cutting through outer layers of tissue. The other edge of the blade may have a rougher wider shape to induce more cavitation and drag, for "teasing" the blade through tissue close to vital organs. Other possibilities include edges preferred for cold-cutting (more cavitation), cauterizing (localized heating) or bone cutting (minimum heating).
Finally, the variations of blade and oscillation character provide the knowledgeable surgeon with a highly advanced and flexible surgical tool. The numerous combinations of the aforementioned surgical knife parameters give the surgeon ultimate freedom in choosing the preferred embodiment.
The present invention has been described in terms of certain preferred embodiments. However, additional embodiments and variations will become apparent to one of skill in the art in view of the disclosure contained herein. Such variations are intended to be within the scope of the present invention. Accordingly, the scope of the present invention is not limited by the specific embodiments disclosed herein, but is to be defined by reference to the appended claims. | Disclosed is an improved ultrasonic knife of a type for incising various types of material. The knife has a reduced thermal footprint to tailor thermally induced tissue effects. Tooth configuration on the knife cooperates with the stroke of the ultrasonic drive to produce efficient cutting, as well as tactile feedback to the surgeon with respect to the rate of cutting, and changes in tissue density. Ultrasonic knife tip extenders are also disclosed for advancing the ultrasonic knife tip through the working channel of an endoscope or trocar sheath. Methods utilizing the foregoing apparatus are also disclosed. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a fluid coupling for use with textile machines, particularly but not exclusively filament winders of the type known as bobbin revolvers.
A bobbin revolver is a machine for winding synthetic filaments; the latter term is here intended to cover continuous lengths of mono-filamentary and multi-filamentary materials. Such materials must be continuously wound on a suitable bobbin tube as they leave the spinneret or a preceding process. A bobbin revolver is designed to carry a plurality of bobbin tubes (usually two) so that when a yarn package upon one of the bobbin tubes is complete, the yarn can be quickly transferred to another tube of said plurality and winding can continue without interruption. Such machines are already well known in the filament winding art; one example of such a machine is described in the British Pat. No. 1,332,182. A development of that machine is described in recently filed U.S. Patent Application Ser. No. 945,330 herein referred to as prior Application. The full disclosure of British Patent No. 1,332,182 and the prior application is hereby incorporated in the present specification by reference.
The machines described in the Patent and prior application above referred to are of a generally known type comprising a positively driven drum as the main drive element for the bobbin tubes. The bobbin tubes can be brought successively into a winding condition in frictional contact with the drive drum, the tubes themselves being mounted on respective chucks which are freely rotatable on chuck shafts provided on the revolver. In such a machine it is desirable to maintain a controlled pressure between the friction drive drum and the bobbin tube or package thereon during a wind. While it is not essential to hold this pressure precisely constant, it is highly desirable that the pressure be held within certain definite limits dependant upon the particular machine or type of yarn to be wound.
Movement of bobbin tubes between winding and non-winding conditions involves rotation of a chuck carrier about a predetermined axis. There is almost always at least one fluid operated device on the rotatable chuck carrier. For example, each chuck will include a clamping device for releasably clamping a bobbin tube in place thereon; it is conventional practice to operate this clamping device by compressed air, at least to cause release of the bobbin tube even if the main clamping effect is achieved by spring operated means. In the more highly developed bobbin revolver described in the prior application, there is in addition a plurality of piston and cylinder units designed to enable adjustment of the positions of the individual chucks on the chuck carrier. Attention is drawn to these fluid operated devices by way of example only; the precise purpose for which pressure fluid is required on the chuck carrier is not important to the present invention.
There is another known form of bobbin revolver in which there is a demand for pressure fluid on a rotatable chuck carrier, namely that described in Japanese Utility Model No. 8739/53 (published Mar. 7, 1978). That specification describes a form of fluid coupling comprising a collar fitted to and rotatable with a shaft which rotates the chuck support. The collar is located within a sleeve and is provided with a plurality of annular grooves facing outwardly towards the sleeve. A corresponding plurality of O-ring seals are provided between the collar and the sleeve so that the grooves are isolated from each other. A plurality of passages lead from respective grooves through the collar to respective tubes which in use communicate with the pressure fluid operated devices on the chuck carrier. Also, a plurality of openings in the sleeve pass from respective grooves to the exterior of the sleeve. The latter is connected to the fixed housing of the machine, so that tubes can be connected to the exterior openings to enable pressure fluid to be fed to the associated grooves. With such an arrangement, the pressure operated devices on the chuck support can be supplied with operating fluid at any angular disposition of the chuck support because the passages in the collar are in permanent communication with their respective grooves.
The bobbin revolver shown in Japanese specification differs, however, from the other revolvers referred to above, in that the chuck shafts are positively driven by individual motors which are mounted on the chuck support. Accordingly, that machine does not require a friction drive drum, and there is no need for accurate control of a winding pressure exerted between the friction drive drum and a bobbin tube or package driven thereby. There is a substantial disadvantage to the fluid coupling described in the Japanese specification when it is applied to a bobbin revolver adapted for use with a friction drive drum and in which it is desired to maintain in use a controlled force urging a chuck towards a friction drive drum by way of the operating system for rotating the chuck carrier. Sliding friction between the two elements of the coupling, the collar and sleeve referred to above, is substantially uncontrollable and produces unacceptable variations in the winding pressure between different machines and possibly even on the same machine between different operating conditions. The machine manufacturer is therefore faced with the problem of individually adjusting each machine to take account of the individual friction performance of the fluid coupling in that machine, and the machine user may be faced with the problem of adjusting the machine to account for different operating circumstances over time.
PRESENT INVENTION
It is an object of the present invention to provide a modified form of coupling which enables the above disadvantage to be avoided. The invention provides a fluid coupling comprising first and second parts rotatable relative to each other about a predetermined axis, at least one channel defined between the parts, a fluid passage in the first part and a fluid passage in the second part said fluid passages communicating with said channel to permit transfer of pressure-fluid from one passage to the other via said channel, the first and second parts being rotatable together in at least one direction about said predetermined axis through a predetermined angle of rotation about said axis and the first part being rotatable in the same direction through a larger angle then the second part.
When a fluid coupling of the above type is included in a bobbin revolver, it can be arranged so that the two parts rotate together (in the same direction) during winding of a package, and hence there is no sliding friction in the coupling to affect the winding pressure between the package and a friction drive drum. The parts are, however, free to rotate relative to each other during other stages of operation of the bobbin revolver, for example during movement of the chucks between the winding and the non-winding conditions. It will be understood that such a fluid coupling on a bobbin revolver will normally have more than one channel and each channel will have its respective pressure fluid inflow and outflow passages associated therewith. There could be five such channels as illustrated in the Japanese specification above referred to or any other number depending upon the requirements for individual pressure fluid supplies and the space available for and within the fluid coupling.
With such a system, it is possible to control the winding pressure by applying a suitable turning moment to the chuck carrier tending to turn it about its axis in a direction urging the chuck in the winding condition towards the friction drive drum. The chuck carrier will in fact rotate about its axis so that the chuck in the winding condition moves away from the friction drive drum during winding of a package thereon (against said applied turning moment) because of the gradually increasing diameter of the package. The air coupling can be so arranged that the parts thereof are rotatable together throughout winding of a package so that the applied turning moment is unaffected by sliding friction between said parts.
Since both parts of the coupling are now rotatable relative to the machine frame, any tube leading from the coupling to a part fixed to the machine frame must be flexible or at least include a flexible portion. Limits should be placed upon rotation of a coupling part having such tubes connected thereto and these limits will normally permit a rotation of such a coupling part through less than 360° and preferably less than 180°. Arrangements may therefore be made to return such a coupling part from its angular disposition at the completion of winding a package to a starting disposition suitable for winding of the next package. Preferably such arrangements are incorporated into the general operating mechanism of the machine so that the return motion does not require an additional drive system. Where, as is conventional, the bobbin revolver itself is driven by a reversible drive system, for example comprising a piston and cylinder unit, the return for said returnable coupling part may be associated with said reversible drive system. Said coupling parts may rotate together by reason of static frictional forces between them during rotation of the chuck carrier while a package is being wound. At completion of winding of a package said returnable coupling part may be engaged by said reversible drive system travelling in a predetermined direction to return it to its starting position. The other coupling part will normally continue to rotate in the same direction as the full package is moved away from the friction drive drum during bobbin tube exchange. Where there is a reversible drive system for the bobbin revolver, there may be a free wheel connection between the drive system and the chuck carrier. However, the fluid coupling of the present invention is not limited to use with revolvers of this type since the chuck carrier itself could be reversibly rotatable. In any event, the degree of rotation of the coupling part fixed to the chuck carrier will normally be substantially greater in a given direction than the degree of rotation required of the other coupling part in the same direction.
BRIEF DESCRIPTION OF THE DRAWINGS
By way of example one embodiment of the invention will now be described with reference to the accompanying diagrammatic drawings, in which:
FIG. 1 is a diagrammatic end elevation of a bobbin revolver;
FIG. 2 is a side elevation in section of a fluid coupling mounted on the bobbin revolver shown in FIG. 1, the section corresponding with the line II--II in FIG. 1, and
FIG. 3 is a diagrammatic section on the plane III--III in FIG. 2 and showing part only of the fluid coupling and bobbin revolver for the purpose of description of the sequence of operations of the various elements.
DETAILED DESCRIPTION OF THE INVENTION
Since the details of the bobbin revolver construction are not essential to the present invention, FIG. 1 shows only the important elements of a bobbin revolver in schematic form. The machine comprises a frame 10 providing bearings (not shown) for a main shaft 14 to which a chuck carrier or support 12 is secured for rotation with the shaft about the longitudinal axis of the latter. Carrier 12 supports two chucks 16 A and 16 B. Although the details of these chucks are not illustrated, each chuck comprises a chuck shaft projecting in cantilever fashion from carrier 12; a bobbin tube receiving structure mounted for rotation about the longitudinal axis of the chuck shaft; and a bobbin tube clamping system for releasably securing a bobbin tube to the receiving structure for rotation therewith during winding of a package and operable to release the bobbin tube at the completion of winding to enable its removal from the chuck and replacement of the full bobbin tube with an empty tube.
The bobbin revolver also comprises a friction drive drum 18 which is mounted in bearings in frame 10 and can be driven (by means not shown) around its own longitudinal axis. Further, there is a traverse mechanism 20 which receives a filament 22 from a spinneret (not shown) and reciprocates the filament longitudinally of drive drum 18. In use, a bobbin tube or package on a chuck 16 in the winding condition is urged against drive drum 18 and is rotated around the chuck shaft through frictional contact with the drum. After leaving traverse mechanism 20, filament 22 is led around a portion of the circumference of drum 18 before being wound on the bobbin tube on chuck 16. The bobbin tube is driven at a constant peripheral velocity equal to the controlled peripheral velocity of drive drum 18. Filament 22 is therefore drawn forward at a substantially constant speed longitudinally of itself. Traverse of the filament axially of drum 18 and the bobbin tube by traverse mechanism 20 causes winding of the filament into the package at a predetermined wind-angle controlled by the relationship between the traverse speed and the speed of movement of the filament longitudinally of itself.
As indicated above, it is desirable to maintain a substantially constant (or at least controlled) winding pressure between the bobbin tube/package and friction drive drum 18. This is done by applying a predetermined torque to shaft 14 tending to turn carrier 12 in an anti-clockwise direction as viewed in FIG. 1, urging the chuck 16 in the winding condition towards drive drum 18.
As the package diameter increases, however, the chuck must move away from drive drum 18 and chuck carrier 12 is rotated in a clockwise direction as viewed in FIG. 1, against the applied torque, to permit buildup of the package.
Upon completion of winding of the package on one chuck 16, carrier 12 is rotated so as to bring the second chuck into the winding condition and to move the first chuck into a position where the full package can be removed from the chuck. In the course of this rotation of chuck carrier 12, filament 22 is transferred from the first to the second chuck and severed inbetween them. Arrangements for effecting such transfer are already well known and form no part of this invention, so that they will not be described herein. After release of the clamping mechanism of the first chuck, the full package can be removed from the chuck and replaced by an empty bobbin tube ready for a similar exchange upon completion of a package on the second chuck.
It is conventional practice to have pneumatically operable clamping mechanisms for the individual chucks 16. In addition, there may be other fluid operated devices (preferably pneumatically operable) mounted on the carrier 12. While the present invention is not limited to use with the bobbin revolver described in the prior application, reference to that application will show that there is a demand for supply of air to a plurality of piston and cylinder units enabling controlled pivotal movement of each chuck 16 on the carrier 12. There may be other demands for pressure fluid (hydraulic or pneumatic) on carriers 12 of different design. A fluid coupling is required to supply such demand and FIG. 2 shows a fluid coupling suitable for supplying operating fluid to devices mounted on the carrier 12 of the bobbin revolver shown in FIG. 1.
FIG. 2 again shows the main shaft 14 together with a portion of a carrier 12 suitable for the revolver described in the prior application; since details of the carrier are not important to this invention, only a mounting plate 24 which serves as a member rotatable about an axis is shown to which the fluid coupling itself is secured and which other portions of the carrier 12 are secured by connectors 26 extending to the left as illustrated in FIG. 2. The bearings by which carrier 12 is mounted in frame 10 are provided in those other, non-illustrated portions to the left of the parts seen in FIG. 2, and a connection (diagrammatically indicated at 13) between shaft 14 and carrier 12 is also made in the non-illustrated portions. It will be understood, that through the non-illustrated connections, plate 24 is rigidly secured to shaft 14 for rotation therewith.
Secured to plate 24 by means of pins 28 is a housing 30, having a generally cylindrical bore 32. A sleeve 34 is located in the bore 32 with the external surface of the sleeve 34 contacting surfaces of the housing 30 as will be further described below.
The bore 32 of housing 30 is provided with two series of annular grooves. The first series comprises six grooves or channels indicated by numeral 36 and the second series comprises five grooves indicated at 38. Grooves 38 alternate with grooves 36 along the axis of the housing 30, with a groove 36 adjacent each axial end of the housing. Grooves 36 are slightly deeper than grooves 38 and they receive O-ring seals 40, which contact the external surface of the sleeve 34 and thereby prevent passage of fluid from one groove 38 to the next by leakage between the housing 30 and sleeve 34. Housing 30 also has five bores 42 extending from the external surface of the housing to communicate with respective grooves 38. The remaining surface of bore 32 is in the form of a series of lands between grooves 36 and 38 and these lands are in sliding contact with the external surface of sleeve 34.
At its end remote from plate 24, sleeve 34 has a projection 46 extending axially and radially beyond bore 32 of housing 30. The projection is segment-shaped, extending around only a portion of the periphery of sleeve 34 as indicated by the diagram in FIG. 3. Five axial bores 48 (only one of which can be seen in FIG. 2) extend through the sleeve 34 and projection 46, being spaced circumferentially around the sleeve 34. The bores 48 extend to different axial depths of sleeve 34 and have side passages to enable them to communicate with respective grooves 38 in housing 30. Bores 48 also communicate with respective side passages 50 extending radially through the projection 46.
In use, five flexible tubes 52 (FIG. 3) are connected to respective side passages 50 and also to one or more sources of compressed air located on a fixed machine frame. The tapping passages 42 in housing 30 are connected via suitable leads 44 to respective pneumatically operated devices (not shown) on carrier 12, which devices exhaust to atmosphere. Since housing 30 is rigidly fixed to plate 24, the leads 44 will not be required to flex to any substantial extent in use. The leads 52 to passages 50 will, however, be required to flex substantially as will be described below. Although not shown in FIG. 2, projection 46 has secured thereto to plate 47 (FIG. 3) which lies between the leads 52 and the housing 30.
Although the structure of the revolver is generally the same as that described in prior application, there is a difference in the system for rotating the shaft 14. In the prior application, a pair of pneumatic cylinders operated directly upon a disc secured to the end of the shaft. In the construction shown in FIGS. 2 and 3, the driving power for rotating shaft 14 is derived from a single pneumatic cylinder 53 (FIG. 3) fixed to the machine frame and reciprocating a piston 54 with a connecting rod 56 secured thereto. This reciprocating drive is converted to rotation of shaft 14 via a rack 58 secured to connecting rod 56 and a pinion 60 rigidly secured to shaft 14. The rack 58 is formed on a slider 62 which can slide along a guide rod 64 mounted at its upper end in a coupling 66 which can pivot in a portion 68 of the machine frame. At its lower end rod 64 is pivotally secured to a connecting rod 70 and thence to the piston 72 of a second piston and cylinder unit. When piston 72 is drawn to the left in its cylinder 74 (as viewed in FIG. 3), rack 58 engages with pinion 60 and the drive from piston 54 is transmitted to shaft 14. When piston 72 is moved to the right as viewed in FIG. 3, rack 58 is disconnected from pinion 60 and movement of piston 54 does not result in rotation of shaft 14.
Both of the cylinder and piston units 53-54, 72-74 are double-acting, as indicated by the pressure leads 76, 78, 80, 82, to the ends of cylinders 53, 74 in FIG. 3. The pressurisation of those leads is under the control of a central control unit (not shown) which operates to produce the following sequence after first contact of a bobbin tube on, say, chuck 16 A with friction drive drum 18, that is after the start of winding of a package on chuck 16 A. Firstly, lead 82 is pressurized and lead 80 is opened to permit the piston 72 to draw rack 58 into contact with pinion 60. At this stage, slider 62 is at its uppermost position on guide rod 64, as indicated in full lines in FIG. 3, and lead 78 is pressurized at a substantially predetermined value tending to hold slider 62 and rack 58 in this uppermost position. Rack 58 is therefore urging pinion 60 in an anti-clockwise direction tending to apply chuck 16 A against friction drive drum 18, the torque on shaft 14, and hence the force urging chuck 16 A towards the drum 18, being determined by the pressure applied at lead 78.
As the size of the package increases, chuck 16 A is forced away from drum 18, rotating shaft 14 and pinion 60 in a clockwise direction as viewed in FIG. 3 against the applied torque. Leads 76 and 78 permit flow of air into and out of cylinder 53 such that the applied torque remains substantially constant and varies in a substantially predetermined fashion during the wind. Slider 62 is therefore forced downwardly reaching on intermediate position 62a, indicated in dash-dot-lines, at the completion of winding of a package. During this same period, plate 24 and housing 30 will be driven through the same angle as shaft 14 and pinion 60.
Because of the static friction between housing 30 and the sleeve 34, caused by the O-ring seals 40 and contact of the sleeve 34 with the lands in the bore 32 of the housing, the sleeve is carried along with housing 30. Projection 46 on the sleeve rotates from the full line position (FIG. 3) at the start of a wind to the position 46a indicated in dash-dot-lines. Leads 52 must flex correspondingly. Also a telescopic member 84, which is pivotally connected to the projection 46 and to a part 86 of the machine frame, pivots from the full line position to the dotted line position where the limit of its contraction prevents further rotation of projection 46 and therefore avoids any risk of snagging of leads 52 on other parts of the machine. It will be noted, however, that throughout winding of a package on the chuck 16 A there is no relative rotation of housing 30 and sleeve 34 and therefore no sliding friction between those parts. Accordingly, none of the motive power derived from cylinder 53 as a source of motive power is taken up in overcoming such sliding friction, and the torque applied to shaft 14 during winding of a package is accurately determined by the pressure applied to the lead 78.
At the completion of winding of the package, carrier 12 must continue to rotate in the same direction as it has rotated during the wind in order to carry the package away from drive drum 18 and to bring chuck 16 B into the winding condition. Accordingly, when slider 62 is at the intermediate position 62a, lead 76 is pressurized and lead 78 is depressurized so that pinion 60 continues to rotate in a clockwise direction but now under the motive power of the pressure in the upper chamber of cylinder 53. This motion continues until slider 62 reaches the lower end of guide rod 64 as shown in dash-dotted lines in FIG. 3. Since projection 46 and sleeve 34 are now stationary relative to the machine frame, there is relative rotation between the sleeve 34 and housing 30. However, since winding of the package is now complete, the disturbing influence of this sliding friction has no effect upon quality of the package.
Lead 80 is now pressurized and lead 82 is depressurized to pivot guide rod 64 anti-clockwise as viewed in FIG. 3 about the coupling 66. Rack 58 is therefore free to move upwards without rotating pinion 60. The pressurization of leads 76, 78 is now reversed so that piston 54 is driven upwardly carrying slider 62 and rack 58 upwards towards the starting position. During this motion, finger 88 mounted on slider 62 engages the underside of a lever 90 which projects from the plate 47 secured to extension 46. As such, the finger 88 and lever 90 act as abuttments for each other. When the finger 88 first engages the lever 90, the latter being in the dash-dot position shown in FIG. 3, upward movement of the slider 62 and finger 88 rotates the lever 90, projection 46 and sleeve 34 about the axis of shaft 14 to return them towards the starting position. Thus, the slider 62, finger 88 and lever 90 constitute a return device to return the sleeve 34 to its original position. Since rack 58 does not engage pinion 60, there is no accompanying rotation of housing 30 and once again there is sliding friction between the sleeve 34 and the housing. However, this again has no operational significance because at this stage winding pressure is not applied via shaft 14.
When the slider 62 reaches its uppermost position, pressurization of the leads 80, 82 is reversed so that guide rod 64 is returned to the disposition shown in FIG. 3 and rack 58 once again engages pinion 60. Finger 88 slides along lever 90 to the position illustrated in full lines in FIG. 3. The member 84 is now almost fully extended so that lever 90 and projection 46 cannot be rotated very much further in the anti-clockwise direction, thereby preventing accidental damage to the leads 52. When the pressurization of the lower chamber of the cylinder 53 is adjusted to a desired level, the parts are now ready to repeat the sequence of operations described above. It will be understood that since finger 88 is free to move relative to lever 90, the finger 88 simply moves downwards away from lever 90 when the latter is in the dash-dot position shown in FIG. 3, and the length of the lever 90 is sufficient to ensure that finger 88 will engage the lever 90 during upward motion of the finger 88, even though guide rod 64 is then pivoted to the right when compared with its position shown in FIG. 3. The above completes the description of the operation of the fluid coupling itself. By way of completeness of description of the illustrated parts, reference is made to the tubular shaft 92 which surround shaft 14 and projects through the sleeve 34 so that the end of the shaft 92 lies within projection 46. This free end of shaft 92 is coupled with a drive band 94 and the tubular shaft 92 is mounted in bearings 96 in plate 24 so that it can be rotated independently of shaft 14. Shaft 92 drives an acceleration ring on the carrier 12, the acceleration ring serving to bring a chuck 16 up to operating speed before it contacts friction drive drum 18. This arrangement forms no part of the present invention, but in the illustrated embodiment the angular extent of the segment-shaped projection 46 around the axis of shafts 14 and 92 must be limited to provide freedom of access for band 94 to shaft 92 throughout rotation of sleeve 34 and projection 46.
The invention is not limited to the embodiment illustrated in the drawings. A fluid coupling in accordance with the invention may be used with textile machines other than bobbin revolvers and with bobbin revolvers other than those described above. In particular, the exact sequence of rotations of the parts of the fluid coupling is not essential to the invention. For example, in the illustrated embodiment, carrier 12 is rotated persistently in one direction only, necessitating a free wheel connection between pneumatic cylinder 52 and shaft 14. The mechanical arrangement could, however, be such that the chucks 16 are brought into contact with respective winding points on opposite sides of a radial plane passing through the axis of the drum 18, so that the direction of motion of carrier 12 is reversed each time a chuck 16 engages drum 18. In this case, there may be no need for a return device, such as finger 88 and lever 90, to return projection 46 from the dash-dot to the full line position shown in FIG. 3. The sleeve 34 will merely be "picked up" by housing 30 during the reverse rotation of the latter and carried along to the limit of extension of member 84. With such a reversible arrangement, it may be possible to arrange the mechanism so that the grooves extend around only a portion of the periphery of the sleeve 34.
Even with this arrangement, however, the degree of rotation permitted for two parts will be different, because a two-part coupling (with continous or arc-type grooves) only has a purpose if the permitted angle of rotation of one part is less than that of the other, usually because of the necessity to connect the one part to fixed equipment such as a pressurized air source. In the case in which housing 30 rotates continually in one direction, as illustrated in the drawings, it is clearly impossible to permit sleeve 34, with the connected flexible leads 52, to follow this continual rotation. The angle of rotation permitted to the projection 46 and sleeve 34 may vary from that illustrated in FIG. 3, but these parts will usually be rotatable through less than 180°. In same instances, the one part may be rotatable through limited angular increments rather than between fixed angular positions, for example pending adjustment of other equipment on the machine-frame. Where the one part is limited to rotation between fixed positions, means alternative to the telescopic member 84 may be used to limit to rotation.
The invention is not limited to pneumatic couplings. The arrangement shown could be used to transmit pressurized liquid or a vapour (mist). Further, the number of channels, the form of each channel and the type of sealing means between them can be selected to suit the circumstances of use. For example, the channels could be formed by facing grooves in housing 30 and sleeve 34, but this is an undesirable option because it requires accurate location of the sleeve relative to the housing in order to align the grooves axially. Obviously, the grooves could be provided in the exterior of the sleeve 34 instead of in the interior of the housing 30. Further, in an alternative arrangement, the part 34 might be secured to the plate 24 for rotation therewith and the surrounding part 30 might have the flexible leads 52 secured thereto.
Where the grooves are formed in one only of the coupling parts, as illustrated in the drawings, and extend over part only of the circumference of the facing surfaces, it is not essential to the present invention that the passages in the other coupling part communicate with the grooves throughout relative rotation of the coupling parts. Whether or not this is necessary depends entirely upon the required mode of operation of the pressure fluid devices on the chuck carrier, and as indicated above that mode of operation is not important to this invention. It would be possible, for example to perform a switching function by having a passage in the non-grooved part move out of communication with the groove in the other part at a predetermined stage of relative rotation of those parts.
Further, it is not essential to the invention that each groove be pressurised continuously during operation. The devices provided on the carrier 12 may comprise a fluid logic unit requiring intermittent pressurisation to perform a control function in accordance with same prearranged cycle. In one convenient arrangement, pinion 60 is provided with a member shown with dotted lines at 96 in FIG. 2: this member is provided at a particular location on the pinion or extends around only part of the periphery of the pinion. A sensor (not shown) is provided on the machine frame and is responsive to the angular position of member 96 relative to the axis of shaft 14. The sensor is connected into an electrical circuit (not shown) which is thus responsive to the current disposition of the pinion 60 and carrier 12 which rotates therewith. Hence, the circuit is responsive to which chuck, 16 A or 16 B, is currently in the winding condition. The electrical circuit may control a valve (not shown) in one of the leads 52 to control pressurisation/depressurisation of the corresponding groove 38 in dependence upon which chuck is in the winding condition. The depressurisable groove 38 may feed a fluid logic unit which controls switching of pressure from the other grooves 38 to perform appropriate operations as the carrier 12 rotates. The sensor is preferably of the non-contact type to avoid introduction of sliding friction.
In FIG. 2 only five passage 42 in housing 30 are shown--one for each groove 38. In that Figure they all appear at about the same angular disposition about the axis of the housing. Clearly, there can be two or more passages 42 leading from each groove 38 depending upon the demand on the carrier and the ability of a single groove to supply that demand. The various passages can be spaced angularly around the housing axis as is found most convenient for production and assembly of the machine. In one convenient arrangement, there are two sets of passages in housing 30; each set comprises five passages which are associated with respective grooves 38, i.e. two passages per groove. The passages of one set supply devices associated with one chuck and the passages of the other set supply devices associated with the other chuck. The passages of the first set are angularly aligned and the passages of the second set are angularly aligned, but the two sets are spaced angularly, say, 180° about the housing axis.
Where the grooves are used to communicate hydraulic pressure rather than pneumatic pressure, it will be necessary to provide a flow circuit comprising both a "go" groove and a "return" groove. For this reason, the coupling is more conveniently used to transmit air pressure, the air being exhausted to atmosphere after use on the carrier. | A bobbin revolver for winding textile filaments has a rotatable chuck carrier with a plurality of bobbin chucks. The carrier is rotatable on a central shaft to urge the chucks successively towards a friction drive drum which rotates bobbins on the chucks to wind filament packages thereon. A fluid coupling, comprising co-axial, relatively rotable parts having communicating passages therethrough, is provided around the shaft to pass pressure fluid to and/or from devices on the carrier. The fluid coupling is arranged so that there is no relative rotation of its parts during winding of a package, thereby avoiding disturbance of the contact pressure between a package and the friction drum through sliding friction between the coupling parts. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application constitutes a utility application for Letters Patent to that certain Provisional Application Serial No. 60/095,147, filed Aug. 3, 1998.
FIELD OF THE INVENTION
The present invention relates generally to elevated decks for residential buildings, and more particularly to a rain water collection system for the underside of such decks to maintain a dry space there beneath.
DISCUSSION OF THE PRIOR ART
Exterior structures, such as decks, gratings and walkways, are typically designed to allow water to fall through the spacing between adjacent decking boards or other apertures. It may be desirable to otherwise collect this water to thereby make the space under such surfaces dry. The object of the present invention is to provide an impermeable assembly which may be easily mounted to the underside of existing decks, gratings or walkways, which collects and routes rain water to a discharge point while maintaining the area under the deck free of dripping water.
The closest prior art of which we are aware is the Moore U.S. Pat. No. 5,511,351. The patent describes a water collection and drainage system that is adapted to be attached to the underside of a residential deck and comprises flexible sheets that are affixed to deck joists so that they present concaved upper surfaces and convexed lower surfaces. While this structure may be suitable for use in climates that are not subject to freezing, the underdeck water collection system described in the Moore patent is unsuitable for use in freezing climes. In freezing climes, water from melting snow on the deck will fall between adjacent deck boards onto the concave collector structure suspended therebeneath. When out of the rays of the sun, the temperature beneath the deck very often is below freezing temperature, resulting in a build-up of ice thereon. Over a period of several days of thawing and freezing temperatures, the weight of the ice can cause the suspension structure to fail.
Another drawback of the apparatus described in the Moore '351 patent is that the flexible connectors extend below the bottom of the deck joists, thereby limiting the head room under the deck.
It is a further object of the invention that the impermeable assembly be comprised of a versatile system of components which may be easily assembled on site by a single person to form an aesthetically pleasing surface beneath the deck which drains all water to the perimeter of a deck, grating or walkway and which can be used in climates where frequent freezing and thawing occurs.
It is a further object of the invention to minimize the encroachment of the headroom space beneath the deck by the impermeable assembly.
It is a further object of the invention that at least some of the elements of the impermeable assembly be removable for maintenance and repair.
SUMMARY OF INVENTION
The invention will be taught with respect to residential decks which are typical of other exterior structures which could benefit from the invention. FIG. 1 shows a typical residential deck comprised of joists 10 , end plates 12 and deck boards 14 . Actual decks have a wide variety of sizes and shapes, however, between centers, the joist-to-joist spacing is typically 16″, and if not that then typically 24″. The description of various embodiments will be with orienting reference to a typical deck structure. As used herein longitudinal refers to the orientation along a line parallel to the deck joist while transverse refers to the orientation along a horizontal line perpendicular to the deck joist. With reference to the boundary edges of the deck the side edges are longitudinal while the front and back edges are transverse.
FIG. 2 ( a ) shows, conceptually, the surface contour of an impermeable water collection assembly constructed according to certain aspects of the disclosed embodiments. FIG. 2 ( b ) shows the end view of the surface of FIG. 1 . The surface is comprised of periodic peaks and valleys.
Water flows transversely into the gutter and then longitudinally to the perimeter of the deck. By controlling the slope or pitch of the assembly, water may be directed to flow to a single edge where it may undergo further collection by means which are not part of this invention. The realization of an impermeable assembly suspended to the underside of an existing structure presents problems not found in art which might otherwise be considered related. For example, prior art impermeable roofing systems which are applied to the top side of an underlying supporting structure are not adaptable to a suspended system. Further, the prior art structure and methods used to realize a permeable suspended ceiling are not amenable to modification which would render them impermeable. The subject invention realizes the impermeable surface of FIG. 2 ( a ) in a novel way which results in an attractive, yet inexpensive system which is exceptionally easy to install and to maintain beneath decks and walkways. In certain of the embodiments disclosed herein, the impermeable assembly is sectioned according to FIG. 2 ( c ). Collectors 20 are convexed on their upper surface to define peak regions which direct water transversely to their side edges and, thus, into inclined gutters 22 which comprise the valley regions directing water longitudinally to the edge of the deck. Gutters 22 are disposed directly beneath deck joists 10 and are attached thereto by various means. Collectors 20 are attached, or otherwise constrained so that their side edges are vertically overlapping with respect to gutters 22 to prevent leakage and to thus render the resulting assembly water impermeable for a typical rain shower. “Impermeability”, as used herein, does not require a watertight tight seal which would withstand gale force winds even though this capability is present in certain embodiments. Collector 20 may have an inverted V or a more crowned convex shape which provides useful stiffness, allowing relatively thin and inexpensive materials to withstand the stress of wind when so shaped. The crowned shape is achieved without loss of headroom in that the crown resides in the cavity between adjacent joists.
Thus, in a general sense, the present invention comprises rain water collection apparatus that is adapted to be affixed to an underside of an elevated, water-previous, deck structure of the type where a plurality of parallel, regularly-spaced, longitudinally extending joists project from a building structure and with a plurality of deck boards secured to an upper edge surface of the joists and which extend generally transversely to the joists. The collection apparatus comprises resilient, water-impervious, rectangular collector sheets having a predetermined length dimension and a width dimension between opposed side edges that is greater than the regular spacing between adjacent ones of the joists. Means are provided for mounting the collector sheets between adjacent ones of said joists for supporting the sheets in a space between adjacent joists with an upper surface of the sheets convex and a lower surface of the sheets concave. A plurality of gutter members are attachable to the joists and span the bottom edge of the joists to vertically overlap side edges of the collector sheets, such that water seeping between adjacent deck boards falls on the upper convex surface of the collector sheets and then flows laterally into the gutter members disposed beneath the side edges of the collector sheets. The gutter members are at a pitch such that the water therein flows to the outer perimeter of the deck structure.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts.
FIG. 1 is a perspective view, partially sectioned, to show the general construction of a typical residential deck;
FIGS. 2 ( a ), 2 ( b ) and 2 ( c ), respectively, show a perspective view of a collector component of one embodiment of the invention, an end edge view of the collector of FIG. 2 ( a ) and the gutter component thereof;
FIG. 3 ( a ) is an end view of a pair of adjacent deck joists with a collector and gutters suspended therefrom;
FIG. 3 ( b ) is a partial perspective view of a mounting bracket for connecting a gutter component to a joist;
FIG. 3 ( c ) is an end edge view of the mounting bracket affixed to a joist;
FIG. 3 ( d ) is an end view of a gutter design suitable for the outer side edges of the decks;
FIG. 3 ( e ) is a cross-sectional view of an alternative embodiment for a mounting bracket for connecting a gutter component to a joist;
FIG. 3 ( f ) is a front view of the mounting bracket of FIG. 3 ( e );
FIG. 3 ( g ) is a front elevation showing a different style of mounting bracket suspending a pair of collectors and a gutter from a joist;
FIG. 3 ( h ) shows the mounting bracket of FIG. 3 ( g ) when used to suspend a specially designed gutter from a rim joist;
FIG. 4 is a perspective view of the collector component in coiled form prior to installation beneath a deck structure;
FIGS. 5 ( a ) through 5 ( h ) illustrate the components of an alternative embodiment of the invention;
FIGS. 6 ( a ) through 6 ( d ) show the components of an alternative embodiment of the invention;
FIGS. 7 ( a ) and 7 ( b ) show an alternative gutter component and mode of attachment to a deck joist;
FIGS. 8 ( a ) through 8 ( d ) illustrate yet another embodiment for attaching collectors and gutters to the underside of a deck or walkway;
FIG. 9 ( a ) illustrates a continuous gutter support member in an exploded view;
FIG. 9 ( b ) is an end view of the gutter engaging the support member;
FIGS. 10 ( a ) through 10 ( d ) graphically illustrate the necessity of maintaining control over the collector contour to prevent puddling;
FIGS. 11 ( a ) through 11 ( d ) illustrate components for mounting a continuous collector sheet designed to span a plurality of joists so that water will drain from the surface of the collector without puddling;
FIGS. 12 ( a ) through 12 ( e ) show a tensioning apparatus for controlling the profile or contour of the collector sheets;
FIGS. 13 ( a ) through 13 ( e ) illustrates an arrangement for imparting a desired contour to pliable collector sheets;
FIGS. 14 ( a ) through 14 ( d ) schematically illustrates the manner in which the system of the present invention can be applied in different size modules;
FIGS. 15 ( a ) through 15 ( f ) illustrate a combined configuration of mounting and shaping devices for affixing a compliant sheet collector to the undersurface of a deck or elevated walkway;
FIGS. 16 ( a ) through 16 ( e ) illustrates another alternative configuration for securing collectors and gutters to the underside of an elevated deck structure; and
FIGS. 17 ( a ) through 17 ( c ) illustrate other shape profiles for coilable collector panels useable with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIGS. 2 ( a ) through 2 ( c ), the rain water collection apparatus of the present invention comprises a plurality of collector sheets 20 that are formed so as to be convex on their upper surface and concave on their lower surface when installed between joists 10 of an elevated deck structure. The collectors may be thin aluminum sheets or preferably roll-formed, generally rectangular plastic sheets of a sufficient thickness and resiliency so that when bowed, they will provide a counteracting force tending to return the sheet material to a planar condition. To provide longitudinal rigidity, the individual sheets spanning adjacent joists can be corrugated as indicated in FIGS. 2 ( a ) and 2 ( b ), but in most instances, this is unnecessary unless, of course, the sheet material of the collector 20 is quite thin.
FIG. 3 ( a ) shows a collector and gutter system wherein collector 32 is compressively retained by mounting brackets 30 in a position which allows water to drain between the side edge of collector 32 and joist 10 . Gutter 36 is also retained by mounting brackets 30 . It is formed of a resilient material with a radius somewhat smaller than the installed radius such that, when being installed, it must be spread so that when released, there is a compressive force acting to maintain contact with the bracket.
Mounting brackets 30 are mounted to facing vertical sides of adjacent joists 10 . Additional brackets, not shown, are mounted along the joists at an interval sufficient to provide adequate support. There is a trade off which must be made here. The number of attachment points should be minimized for ease of installation, however a larger interval between mounting brackets requires a stiffer, and thus more expensive, collector and gutter design. FIGS. 3 ( b ) and 3 ( c ) show one type of mounting bracket 30 in more detail. Shown here is tab 34 which functions to partially retain collector 32 . If the collector is fabricated of crimpable material, such as aluminum or galvanized steel, additional retention may be accomplished by crimping the edge of collector upward so as to be locatable behind tab 34 as shown in FIG. 3 ( c ). Collector 32 is installed by transverse compression to snap into mounting brackets 30 . Alternatively, mounting bracket 30 could be modified to accommodate any well known fastening means to retain the collector by piercing it. For example, apertures in the mounting bracket would allow a nail to pierce the collector and attach to the joist. Collector 32 may be any sheet material which will maintain a crowned shape under side-edge compression.
As shown in FIG. 3 ( b ) gutter 36 is formed with side lips or flanges 37 . The gutter is suspended from mounting brackets 30 by engaging flange 37 with tabs 38 and 40 . Gutters 36 may be formed of any material and process which results in a semi-rigid structure. As used herein the term semi-rigid refers to a structure which would not sag or otherwise deform as installed. The embodiment of FIGS. 3 ( a )- 3 ( c ) requires a semi-rigid structure, such as extruded PVC, to span the distance between mounting clips without sagging.
FIG. 3 ( d ) is an end view of a gutter design suitable for the interior side edges of the decks. As shown, gutter 42 is attached to the inside face of an outermost joist with screw 31 . The gutter can be reversed end-for-end, when attaching it to the inside face of the opposite outermost joist. An elongated slot in gutter 42 provides for thermal expansion and contraction.
FIGS. 3 ( e ) and 3 ( f ), respectively, show a front view and a cross-sectional view of an alternative embodiment of a mounting bracket 46 for connecting a gutter component to a joist which may be formed by injection molding of a plastic. Mounting bracket 46 is fastened to the side of joist 10 by nails, not shown, which pass through nail holes 48 and 49 . Slot 47 in bracket 46 receives an edge of collector 32 therein as well as an inwardly turned flange of gutter 36 , each being retained by the aforementioned compressive forces.
FIG. 3 ( g ) illustrates by means of an end view a mounting bracket 30 ′ that differs slightly from that shown in FIG. 3 ( a ). The mounting bracket 30 ′ comprises an extruded strip approximately 20 in. in length and which is adapted to affixed to opposed side surfaces of the joist 10 by means of nails or screws. The extrusion includes upper and lower tines 31 and 33 , respectively, which project obliquely at differing angles from the joist 10 to define an elongated slot therebetween. The slot is dimensioned to receive an edge of a collector panel 32 ′ along with the flange 37 ′ of the gutter 36 ′. In that the collector panels are under compression by virtue of the fact that their widths are greater than the spacing between joists and, hence, are bowed upwardly, they stay retained in the slot of the mounting bracket 30 ′. Likewise, because the side edges of the gutter must be spread apart from one another in order to have the flanges 37 ′ fitted into the elongated slots of the two mounting brackets, the spring force tending to return the gutter to its unstressed state insures that they will not pull free of the mounting brackets without manual intervention.
FIG. 3 ( h ) illustrates the mounting bracket 30 ′ affixed to a rim joist of a deck structure, the rim joist being the outermost joist of the deck. The bracket 30 ′ is nailed or screwed to an inner side surface of the rim joist and, as can be seen, the inwardly extending nubs 39 and 41 act as stand-offs or spacers allowing the thickness dimension of the uncurved portion 43 of a specially shaped gutter member 45 to be sandwiched between the bracket 30 ′ and the rim joist. A protuberance 47 on the gutter 45 cooperates with a finger-like projection 49 on the bracket 30 ′ to snap or latch the gutter in place when the straight portion 43 thereof is forced upward into the space or pocket created by the stand-offs 39 and 41 . Again, the slot defined by the outwardly and obliquely projecting tines 31 and 33 receives the edge portion of a collector sheet 32 ′.
When it is desired to discharge water from only one end of the gutter, discharge from the other end must be blocked by an end cap or end plug, not shown. The end plug is preferably a resilient material, totally contained within gutter 36 , which forms a watertight seal by exerting an expanding force upon the inner surface of the gutter. The end cap may be a plastic structure which pinches the end of gutter 36 to form a watertight seal.
For many deck structures, the collector could be very unwieldily to install as a single section due to its length′. To facilitate handling, the collector may be fabricated with both a longitudinal and transverse stress such that it has two stable rest modes. The first rest mode is achieved by rolling the collector in the transverse direction wherein the crown is formed. The second rest mode is achieved by additionally rolling the collector in the longitudinal direction to make it coil. As shown in FIG. 4, the collector maintains a flat mode when coiled, but converts to the semi-rigid crowned or convex mode as it is uncoiled. It is thus possible for a single person to readily handle and install a single piece collector of virtually any length by simply unrolling same as it is being inserted into its joist mounted support brackets. Alternatively, a long collector may subdivided into a plurality of shorter sections to facilitate handling. There are a variety of well-known ways to accomplish a water-tight seal at the end joints of such sections. For example, VHB type 4622 acrylic foam tape, manufactured by Minnesota Mining and Manufacturing (3M), may be applied to the underside of the collectors after they have been installed. Alternatively, collector ends may be joined with a resilient gasket in either an end-to-end configuration or an overlapping configuration.
FIGS. 5 ( a ) and 5 ( h ) show an alternative means for retaining the collector. With reference to FIG. 5 ( a ), an end view of a U-shaped mounting bracket 50 is shown attached to a bottom edge surface of joist 10 with screw 52 . Spacers 54 may be optionally interposed to add slope or pitch to the system. FIG. 5 ( b ) shows a bottom plan view of mounting bracket 50 , including slots 55 which receive the compression member 58 of FIG. 5 ( d ). The mounting bracket is comprised of relatively stiff resilient material which behaves as a spring to be the source of a compressive force to retain the collector acting through compression member 58 . The heavy solid line indicates the position of the bracket under compression as installed, while dashed lines 56 indicate its position prior to installation of the collector sheets. FIGS. 5 ( c ) and 5 ( d ) show a side view and plan, respectively, of one of the compression members 58 . Compression member 58 is comprised of relatively compliant material. Its wings 60 transmit the compressive force of mounting bracket 50 to region 64 , via hinge points 62 . Dotted lines 63 in FIG. 5 ( c ) show the rest position of wings 60 when unflexed. Connection to mounting bracket 50 is accomplished by ears 61 on the ends of wings 60 which engage slots 55 in the mounting bracket. Compression member 58 operates most efficiently when flexure is confined to hinge points 62 . Toward this end, elements 60 and 64 are stiffened by embossed ribs 66 and 68 while hinge point 62 is made more compliant by reducing the width of the compression member 58 in this region. The result is that only a small fraction of the force from mounting bracket 50 is required to overcome hinge points 62 and a persistent downward retaining force is transmitted to the domed portion of collector 69 (FIG. 5 ( f )).
FIGS. 5 ( e )- 5 ( h ) show the range of flexure of elements 50 , 60 , and 64 . In FIG. 5 ( e ) the compression member 58 has been wedged between the mounting clips 50 and is under a slight compression to hold it in place prior to installing the collector 69 . In FIG. 5 ( f ) these elements have flexed to allow the installation of collector 69 , while in FIG. 5 ( g ) the collector has been set in its installed position.
The system of FIGS. 5 ( a )- 5 ( h ) may be designed to provide a relatively low retaining force sufficient for nominal extremes of wind velocity since the collector is positively retained at the limit of flexure as shown in FIG. 5 ( h ) where mounting bracket 50 has been compressed to an almost vertical position, such that it is now in contact with a joist 10 . This arrangement reduces the susceptibility of the collector to exceptionally severe wind. With collector 69 positively retained with a relatively light retaining force, it may be easily removed for maintenance and repair.
FIG. 6 ( a ) through 6 ( d ) show an alternative embodiment of the deck rain diverter system which could be used in combination with the collector retaining system of FIG. 5 . FIG. 6 ( a ) shows a partial section of a U-shaped gutter 70 having regularly spaced mounting slots 74 formed therein. Mounting slots 74 are pre-formed on the opposed sides of gutter 70 and are periodically spaced along the length of the gutter at an interval sufficient to adequately support it. A mounting clip 76 may be formed from a plastic extrusion which is subsequently cut and drilled. Resilient tabs or fingers 78 are provided to captively mount the clips in the slots 74 while leaving them free to slide within the limits of the slots.
FIG. 6 ( b ) shows a section of a convexly bowed collector component 80 . The side edges of the collector are comprised of joist-contact regions 82 and notch regions 84 being defined therebetween. The contact regions provide a substantially continuous line of side edge support for the collector while the notch regions provide a slot-like opening for water to drain from the domed surface of the collector to the gutter 70 . FIG. 6 ( c ) shows a cross-sectional view of gutter 70 attached to joist 10 . Gutter 70 may be preformed according to the cross-sectional view of FIG. 6 ( d ), such that the mounting clips 76 frictionally engage the joist to temporarily hold the gutter in position. When the gutter is set in final position with a desired pitch for draining water to the free end of the deck, it is attached with screws for permanent placement. The mounting clips are registered in the center of slot 74 to provide for limited movement of the gutter due to the large differential thermal expansion and contraction of plastic material from which the gutter may be formed. For metal gutters, where differential thermal expansion is negligible, the width of slot 74 may be the nominal width of bushing 76 .
Collector 80 is pressed into a continuous linear contact with inclined flange 72 by the action of the collector retaining system of FIG. 5 ( a ). The contact force at this interface is non-uniform, due to deformation of both the collector and the gutter. However, this effect is mitigated and the integrity of the joint is enhanced by placing the attachment point of the collector retaining system midway between the attachment points of clips 76 to the joists. The integrity of this joint may be additionally enhanced by making flange 72 more compliant relative to the stiffness of the total gutter 70 and the collector 80 . If it is desirable to achieve a joint which is watertight in a high wind environment, it can be achieved with the embodiment of FIGS. 6 ( a ) through 6 ( d ).
For this embodiment, the preferred order of assembly is to first install the collector retaining system of FIGS. 5 ( a )-( h ). Next the gutter mounting clips 76 are added to the gutter and the gutter is mounted to the joist. Finally, the collector 80 is snapped into position as shown in FIG. 6 ( c ) in the manner described with reference to FIGS. 5 ( f ) and 5 ( g ).
FIG. 7 ( a ) shows a perspective view of an alternative example of a gutter which is attachable to the bottom of joist. Attachment of gutter 90 is made by a screw inserted through slot 92 . The length of slot 92 provides for differential thermal expansion as described earlier with reference to slot 74 of FIG. 6 ( a ). While it would be possible to achieve a watertight seal for this attachment, it is preferable that the shape of the gutter be modified to provide a dry region which positions the slot above the expected depth of water in the gutter. As shown in FIG. 7 ( a ), a center island is a feature of the extrusion and is thus continuous. Alternatively, discrete islands may be added to gutter 70 of FIG. 6 to achieve the same result, with water flowing in the adjacent U-shaped troughs 93 and 95 .
The embodiments considered thus far have employed gutters which must be semi-rigid to span the attachment points without sagging. It would be desirable to ship and otherwise handle gutters in a coilable form in the manner described with reference to FIG. 4 regarding coilable collector 32 . To be coilable, the gutter must be designed with a relatively large transverse radius. Further, the attachment means must be adapted to work with this shape. FIG. 8 shows such an embodiment.
In FIG. 8 ( a ) gutter 100 may be fabricated and coiled in the manner of FIG. 4, such that, when uncoiled, it snaps into a semi-rigid shape, as shown in FIG. 8 ( a ). A mounting bracket 102 is attached to the underside of joist 10 as shown in FIGS. 8 ( b ) and 8 ( c ) by nails or screws passing through hole 105 . Collector 100 is retained by tabs 104 on mounting bracket 102 , which provide a supporting ledge. Collector retaining band 106 and spring 108 perform the same function as the collector retaining system of FIGS. 5 ( a ) through 5 ( h ). Thus, the collector may be installed and removed in the manner previously described.
Gutter 100 is pre-formed with apertures 110 (FIG. 8 ( a )), which are regularly spaced along the gutter at intervals sufficient to adequately support the gutter. Mounting brackets 102 are first mounted to the bottom of joist 10 by screws or nails passed through aperture 105 at an interval which nominally corresponds to the interval of apertures 110 in tabs 104 . Next, gutter 100 is attached to bracket 102 by plastic or metal spring clips 114 , a perspective view of which is shown in FIG. 8 ( d ). The clips captures the edges of both aperture 110 in gutter 100 and slot 112 in tabs 104 . Slot 112 allows for both the variation in the actual spacing of brackets 102 as well as relative movement due to thermal expansion. As such, gutter 100 can be a plastic material such as PVC having a high coefficient of linear expansion.
FIGS. 9 ( a ) and 9 ( b ) show yet another alternative for mounting the collector and gutter components to joists and provide substantially continuous support for the gutter, to thereby reduce the stiffness requirements of the gutter and improving the integrity of the collector/gutter interface. Mounting brackets, as at 120 , attach to the lower end edges of joists 10 in the manner of bracket 102 of FIG. 8 ( a ). Support members 124 are supported at each end by being engaged in horizontal slots 122 . The substantially continuous support provided by support members 124 allows the gutter to be more flexible, thus making it easier to ship and install and less expensive to fabricate. Tabs 125 are spaced periodically along support member 124 to provide an edge stop for collector 32 such that the compressive force imparted by the collector retaining means positions the collector edge in intimate contact with gutter 126 to thereby improve the watertight integrity of this interface and also to assure the retention of the gutter. For this embodiment, the preferable order of assembly is as follows: First mounting brackets 120 and support members 124 are installed in an alternating sequence along each joist. Next, the collector retaining means are installed between each opposing pair of mounting brackets followed by installation of gutters 126 (the relative order of these two steps are not important). Finally, collectors 32 are snapped into position, relying upon the elasticity of the collector retaining means to allow the edge of the collector to pass by the edge of support member 124 and be forced into the notch formed by tabs 125 .
The embodiments considered thus far have comprised separate collector and gutter means to facilitated fabrication and installation of an impermeable assembly which does not compromise headroom because the joist cavity is used to crown the collector and thereby achieve the desired contour as shown conceptionally in FIG. 2 . Alternatively, headroom may be conserved by employing a tensional-stressed pliable sheet to establish substantially the same contour. Since the pliable sheet acquires its shape through tension, it is not confined to the joist cavity and may span a plurality of joists. Thus, it is possible to control the contour of a relatively large sheet of pliable material to form peaks and valleys for collecting and draining away water passing between adjacent deck boards. If the geometry of the peaks and valleys is judiciously chosen, there will be a drainage path for each point on the pliable sheet and no puddles will form.
It is important to preclude the possibility of puddles, since the weight of any puddle increases the strain on the pliable sheet which may lead to an avalanche type of failure as the size of the puddle increases to further increase the strain. Also, in cold climates, ice formation can present a problem.
The requisite contour is achieved by a tensional stress on the pliable sheet sufficient to assure conformity to the contouring means. The underlying principle is illustrated in FIGS. 10 ( a )- 10 ( d ), which show several examples of strain along a line connecting a peak and a valley. FIG. 10 ( a ) shows an ideal condition where the strain is negligible and the slope is constant. This ideal may be approached by increasing the yield strength of the pliable sheet and stressing the sheet near its yield stress to maintain the surface taught.
FIG. 10 ( b ) shows an example where the weight of the pliable sheet causes an unacceptable strain. A catenary is formed, and the weight of the collected water adds to the strain, thus exacerbating the problem. One solution is to choose a material which is light in weight, has a low modulus of elasticity, and has negligible plastic deformation under stress. This may be best accomplished with a composite material comprising a high performance plastic film and a woven re-enforcing mesh. For example, a woven mesh of fiberglass or graphite could be imbedded between upper and lower layers of Mylar film.
Another solution is to increase the slope of the catenary as shown in FIG. 10 ( c ). However, it is generally undesirable to do so since it reduces headroom which us usually at a premium. The preferable solution for a relatively large deck where headroom is important is shown in FIG. 10 ( d ). Here, a plurality of peaks reduce the span of the catenary to control the droop such that complete drainage is accomplished without excessive slope. However, the location of the intermediate peaks must be chosen judiciously since an intermediate peak which provides drainage for one area may block the drainage of another area. A pliable sheet may be contoured to assure complete drainage by a peak-forming device which exerts an upward force on selected regions of the pliable sheet, a valley-forming member which exerts a downward force on other selected regions of the pliable sheet, and a tensioning means which determines the relative elevation of the regions of the pliable sheet which form a catenary between the peak-forming means and the valley-forming means.
FIGS. 11 ( a )- 11 ( d ) show one example of well chosen peaks and valleys. Valley-forming members 150 , 152 , 154 , and 156 are mounted end-to-end along joists 10 at a slope sufficient to drain collected water to the exit edge. A large surface pliable sheet 151 is stretched across the valley forming members affixed to the underside of the joists and is retained in tension by a tensioning means (not shown). Peak-forming members, as at 158 , are shown in cross-sectional detail in FIG. 11 ( d ). It is comprised of a flexible tapered plate designed to place pliable sheet 151 in waterproof contact with the underside of joist 10 and provide stress relief by distributing the resulting upward force. FIG. 11 ( b ) shows a cross-sectional view through peak-forming member 158 , while FIG. 11 ( c ) shows a cross-sectional view through peak-forming member 160 . Peak-forming members 158 - 168 establish a watershed ridge wherein all water is constrained to flow into and along the valley-forming members 150 - 156 .
FIG. 12 ( a ) shows an cross-sectional view of a tensioning apparatus 178 while FIG. 12 ( b ) shows the elements of the apparatus 178 in an exploded cross-sectional view. A portion of joist 10 , to which 178 , is attached, is shown in phantom line 12 ( b ) for reference in FIG. 12 ( b ). Tensioning apparatus 178 is comprised of an inner core member 180 which may be made of wood and which has been treated to inhibit rot. As shown in FIG. 12 ( c ), barbed metal pins 182 are staked into inner core 180 at a periodic interval along its length and the resulting assembly is attached to joist 10 by screws 184 . The interval between barbed pins is chosen to impart a substantially uniform tensional stress to the pliable sheet 192 after it has been impaled on the barbed pins. A spacer 204 may optionally be used to set the elevation of the tensioning means relative to the bottom of joist 10 and thus allow water to drain over the top. If the tensioning apparatus is used at the right side edge then pliable sheet 186 (FIG. 12 ( b )) is stretched to the desired tension, attached to the barbed metal pins and the excess material (indicated by the dashed line extension) is trimmed away. The same may be done to pliable sheet 188 to tension the left side edge. As shown, the tensioning apparatus 178 performs the function of tensioning and additionally joining two sections of pliable sheets 186 and 188 together.
A retaining clip 190 is pressed onto the inner core as shown in FIG. 12 ( a ). It is designed to additionally stretch the pliable sheets 186 and 188 after they have been impaled on pins 182 , compressively wrapping around inner core 180 to lock into the position shown in FIG. 12 ( a ), and to provide a decorative cover. If required, retaining clip 190 may be additionally secured by screws. Retaining clip 190 may additionally function to provide a water-tight seal at the side walls of inner core 180 .
FIG. 12 ( d ) shows a partial plan view of a system employing tensioning apparatus 178 in various locations while FIG. 12 ( e ) shows an end view of the same system. Joists 10 are shown in dotted lines for reference. Locations 194 and 202 are left-side-edge and right-side-edge tensioning means as previously described. When FIG. 12 ( e ) is considered to be a cell of a wider system comprising a plurality of such cells, then the tensioning apparatus at locations 194 and 202 may additionally function as valley-forming devices. At location 198 the same means functions as a peak-forming device to establish a watershed ridge as previously explained.
Pliable sheet 192 may be continuous or, alternatively, may be spliced at any of the locations 194 - 202 . Spacers 204 - 210 set the slope of the pliable sheet while allowing water to drain to the side edges as best seen in FIG. 12 ( e ). Spacers 212 and 214 may be continuous along their respective joists to present a more attractive side-edge view.
For certain embodiments it is preferable to add a peak-forming means to a location intermediate of the joists after the pliable sheet has been attached. In this position, the elevation of the peak may have a wide range of adjustment to control the tension and shape of the pliable sheet. An example of such a devices is shown in FIGS. 13 ( a )- 13 ( e ). As shown in FIGS. 13 ( a ), 13 ( b ), and 13 ( c ), a screw device 250 is joined to a plastic coated cord 254 by plate 252 to suspend the cord from the bottom of a deck board (not shown). Screw 250 is secured to plate 252 by crimping regions 253 , while cord 254 is secured by crimping regions 255 . A side view of a cleat 256 is shown in FIG. 13 ( c ), while a bottom view thereof is shown in FIG. 13 ( d ). As shown in FIGS. 13 ( c ) and 13 ( d ), cord 254 passes through the center of cleat 256 , and is laced in a conventional figure-eight pattern to provide an adjustable tensioning support for pliable collector sheet 257 . Preferably, the interface of the pliable collector sheet 257 , cleat 256 and cord 254 should be water tight. The free end of cord 254 may be tapered such that it may be readily threaded through an aperture of cleat 256 which would result in a interference fit, thus rendering this interface water tight. If required, a gasket may be added to seal the region between the pliable sheet and the cleat.
FIG. 13 ( e ) shows a tool which may be used to attach screw 250 to the undersurface of a deck board between joists. The tool is comprised of a hollow tube 260 with slot 262 and handle 264 . Cord 254 is threaded through tube 260 and the side edges of plate 252 engage slot 262 . Pliable sheet 257 is pierced and screw 250 is driven into the deck board by the upward pressure and torque provided by tool 258 acting through plate 252 . When the tool is withdrawn the free end of cord 254 will be accessible for attachment to cleat 256 .
The aforementioned means for controlling the contour of the pliable sheet may be combined in a variety of ways to achieve complete drainage. FIGS. 14 ( a )- 14 ( d ) shows some illustrative examples. For each example arrows show the general direction of water flow. The actual direction of flow may vary due to the complex shape of the contour. The joist and end plate structure of the deck are shown as dashed lines for reference. The examples may also be considered as cells to be used in various combinations to extend the area of water collection.
With reference to FIG. 14 ( a ), elements 300 - 308 are peak-forming devices while elements 310 and 312 are valley-forming devices which collectively create a contour for a pliable sheet in the manner explained of FIGS. 11 ( a )- 11 ( d ). The peak-forming means 300 - 308 establish a watershed ridge under joist 10 such that water flows transversely to the region of the valley-defining means and, thereafter, longitudinally to the exit edge as indicated by the arrows as at 313 . FIG. 14 ( a ) is considered to be a 2× cell in that the span of water collection is twice the joist-to-joist spacing. With reference to FIG. 14 ( b ), elements 320 - 328 are peak-forming devices, while elements 330 and 332 are valley-forming devices which create a contour for a pliable sheet in the manner of FIG. 11 . Here, the watershed ridge is staggered to provide a 3× cell such as that described with reference to FIG. 10 . The general direction of flow is transverse to the valley-forming regions followed by longitudinal flow along the valley-forming means as shown by the arrows 333 . By combining 2× and 3× cells, a deck having any number of joist cavities can be accommodated.
FIG. 14 ( c ) shows a 4× cell wherein element 340 is a continuous member which establishes a peak region, i.e., a ridge at center joist 10 . Element 340 may be comprised of tensioning apparatus 178 as shown in FIG. 12 ( a ). FIG. 14 ( d ) shows a 4× cell which collects water to a single point at the exit end of valley-forming device 364 . Element 362 is also a valley-forming device which functions to allow transverse water flow through it as shown by the arrows 363 . Element 360 is a ridge-forming device in the manner of element 340 . Elements 350 - 358 are adjustable peak-forming members as shown in FIG. 13 ( c ). Valley-forming member 362 is attached to joist 10 such that each point along its length is at an elevation intermediate of the elevations of corresponding points along the top surface of element 360 and the bottom surface of element 364 . Peak-forming members 350 - 358 reduce the span of the catenary to mitigate the formation of puddles as described with reference to FIG. 10, while element 362 assures that, in contrast to FIG. 14 ( b ), the resulting ridge line has a saddle point at an intermediate elevation sufficiently low to completely drain all of the water from the right side and sufficiently high to discharge all of the collected water to the exit point. This condition is best satisfied when the height of peak-forming members 350 - 358 are adjusted to the minimum height necessary to insure complete contact between the impermeable sheet and valley-forming devices 362 . Post-installation adjustment of the height of peak-forming means 350 - 358 is very advantageous in this embodiment since improper height adjustment can create blocking ridges and valleys. After installation, these conditions may be readily detected by testing and then corrected by adjustment.
In the embodiments considered thus far, the impermeable assembly has been comprised of discrete means which are collectors and gutters or alternatively continuous pliable sheet means which are contoured to form both collector and gutter regions. The embodiment of FIGS. 15 ( a )- 15 ( f ) shows an example of how elements of the discrete embodiments may alternatively be combined with a pliable sheet and its associated contouring, tensioning, and joining means. In this example the structure of FIGS. 9 ( a ) and 9 ( b ) has been modified to be used with a pliable sheet collector means in a 3× cell configuration. FIG. 15 ( a ) shows an end view of the cell as installed. Gutter 400 corresponds to gutter 126 of FIG. 9 ( a ) while gutter support plate 402 corresponds to bracket 124 of FIG. 9 ( a ). Bracket 402 has been modified to provide attachment points for pliable sheet 404 , as shown in the detailed section of plan view of FIG. 15 ( b ) and the end view of FIG. 15 ( c ). As shown, the bracket 402 is periodically cut and formed to create a pointed hook 408 which impales pliable sheet 404 to retain it in tension in the manner described with respect to the barbed pins of FIGS. 12 ( a )- 12 ( e ). The installation of the pliable sheet may be simplified, and the density of attachment points may be reduced if the side edge of the pliable sheet has a stress distributing cord 406 in a hem thereof. Alternatively, there are many other well known ways to perform this attachment.
With continued reference to FIG. 14 ( a ), pliable sheet 404 is maintained in tension by means of flexible bracket 410 acting through wire link 412 and a flexible mounting pad 414 secured to sheet 404 . Flexible mounting pad 414 , shown in plan view in FIG. 15 ( d ) and in end view in FIG. 15 ( e ) is a circular rubber or plastic element which is suitably bonded to pliable sheet 404 . Wire link 412 is threaded through eye 416 in pad 414 . Elements 418 position pliable sheet 404 below the bottom surface of joists 10 to provide a transverse flow path in the manner of valley-forming means 150 of FIGS. 11 ( b ) and 11 ( c ). In this embodiment, the height of flexible bracket 410 may be accurately established before the pliable sheet is completely installed. This may be accomplished by measurement from the bottom surface, or other feature of valley-forming means 418 , or it may be set after the right-side edge of pliable sheet 404 has been installed as shown in FIG. 15 ( f ). In this figure, flexible bracket 410 is shown in its light stress position. It is raised to the elevation as shown, wherein, the installed portion of pliable sheet 404 is substantially taut and is fastened to joist 10 . Installation is completed by fastening the left-side edge of pliable sheet 404 to mounting plate 402 , thereby deforming flexible bracket 410 to the desired stressed state as shown in FIG. 15 ( a ).
FIGS. 16 ( a )- 16 ( c ) show yet another alternative for mounting the collector and gutter components to joists and providing continuous support for the gutter, to thereby reduce the stiffness requirements of the gutter and improve the integrity of the collector/gutter interface. The mounting system is comprised of a pair of mounting rails 450 constructed according to FIG. 16 ( a ), a two-piece bracket 452 for attaching the rails to the deck joists as shown in FIG. 16 ( b ), and a collector retaining clip 456 as shown in FIG. 16 ( c ). Each of these components may be readily realized using known plastic materials and thermo-forming processes. There are three essential features of rail 450 . Apertures 458 provide vias for water to pass from the collector to the gutter. Projection 462 allows the rail to be captured by the two-piece bracket 452 . Bracket 452 is comprised of a top piece 464 and a bottom piece 466 , each having a mounting hole 468 . Top piece 464 further includes elongated grooves or cavities 470 which receive the rail projections 462 therein. Bracket 452 can be attached at any point along rails 450 thus allowing the rails to run orthogonal to the joists without regard for the joist-to-joist interval.
FIG. 16 ( d ) is a cross-sectional view through the center of the bracket 452 as mounted showing how rails 450 are captured by the compression of bracket pieces 464 and 466 . FIG. 16 ( e ) is a cross-sectional view through the center of rail aperture 458 and the center of collector retaining clip 456 . The flexure and geometry of clip 456 is chosen such that when mounted as shown, the cop is held in a fixed position by tap 472 and exerts a downward force to retain collector 10 . Retaining clips 456 may be located at any aperture and the clip-to-clip interval is chosen to assure continuous intimated contact between the gutter and the rail. The final assembly step is to snap gutter 470 into groove 460 .
It would be desirable to enhance the transverse stiffness of the coiled collector of FIG. 4 while retaining the natural compliance of a relatively thin material. Well-known manufacturing processes may be used to corrugate, or otherwise add, a transverse rib structure to the collector, such that the transverse stiffness of the collector would be substantially greater than its longitudinal stiffness. FIGS. 17 ( a )- 17 ( c ) are illustrative of such a structure.
The embodiments explicitly disclosed are illustrative of the versatility of the individual elements, which may be employed in a wide variety of alternative configurations and combinations to most optimally achieve a desired combination of advantages. For example, various embodiments employing a pliable sheet may be less expensive and easier to install, while embodiments employing flexible or semi-rigid elements may be more durable.
While the invention has been described with embodiments intended to drain rainwater from deck structures, the benefits of an aesthetically pleasing ceiling system which is inexpensive and very easy to install is also desirable for dry or interior applications. Any of the disclosed embodiments could be used without modification in dry or interior applications. Further, it is intended that any of the disclosed embodiments may be appropriately modified for dry applications where impermeability is not required or for interior applications where environmental stress is relatively low.
This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment and operating procedures, can be accomplished without departing from the scope of the invention itself. | A combination of versatile and inexpensive elements are combined on site to create an impermeable assembly which collects water falling through a grating or cracks between adjacent boards of a deck and completely drains it to one or more points at a selected edge. The impermeable assembly is comprised of a plurality of peaks and valleys configured to simplify installation, conserve headroom and provide an aesthetically pleasing finished surface. In a first embodiment, a collector collects the water falling through cracks between boards spanning the space between adjacent joists from which it drains transversely to a gutter positioned beneath the joists. The gutter drains the water longitudinally to the perimeter of the deck. | 4 |
This application claims priority to U.S. Patent Application Ser. No. 60/651,380 filed on Feb. 9, 2005, which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to an improved soil aeration device.
II. Description of Prior Art
In grass fields and other lawn areas which experience sustained vehicular and pedestrian traffic, the turf surface and underlying soil can become undesirably compacted. The problems associated with soil compaction are that rain and fertilizing chemicals are prevented from fully penetrating the ground. The short-term effect of such a condition is that the field will remain soggy for longer periods after a rain, and the long-term effect is the prevention of deep and healthy root system and proper grass growth. Turf aeration is the process of creating channels in the soil so that water, air, and fertilizers can penetrate the ground and be dispersed effectively throughout the soil.
Many devices have been developed to alleviate soil-compaction problems ranging from pitchforks to heavy, tractor-pulled machinery having multiple, reciprocating tines. One tractor pulled heavy commercial device common in the industry today is the turf aerator manufactured by Verti-Drain® under U.S. Pat. No. 4,422,510 issued to de Ridder (hereinafter “de Ridder”), hereby incorporated by reference. That device teaches a main frame which supports several rotary shafts, drive links, and connecting rods which reciprocate a number of pantograph-type mechanisms. In each mechanism, a tine holder having soil-piercing tines is pivotally attached to an upper link in the mechanism, and a lower link supports a spring device which allows the tines to rotate within the soil to create a drain channel. The device is typically powered by the power take-off (PTO) drive of the pulling tractor. The chief advantage claimed by that reference is that the turf surface remains largely undisturbed because of the manner in which the path of the tines is substantially vertical during penetration and withdrawal due to the action of the pantograph mechanism. Examples of Verti-Drains are shown in FIGS. 1-5 .
Another device common in the industry is the “Soil Reliever”, manufactured by Southern Green, Inc. and described in U.S. Pat. Nos. 5,709,272 and 5,570,746, both incorporated by reference in their entirety. The Soil Reliever is a tractor pulled device, PTO powered, and also has a main frame supporting a rotary shaft which drives upper links. Associated with each upper link is a lower link pivotally attached to the frame. The upper link connects to the lower link to cause the lower link to reciprocate. Pivotally attached to the distal end of the lower link is a tine holder, containing a number of removable times. Attached between the tine holder 30 and the frame, below the lower link, is a spring member for biasing the spring against a stop positioned on the lower link. Examples of the Soil Reliever are shown in FIGS. 6-7 .
The main frames of both the Verti-Drain device and the Soil Reliever device contains a rotatable “front” roller (shown in FIGS. 1 , 5 and 7 as reference 10 ) attached to the main frame 6 (for reference purposes, the “front” of the aeration devise is the PTO end, that is, the end closest to the tractor). Front roller 10 is generally placed forward of the plane of the main frame, and hence, may be attached to the main frame with wings 15 as shown in FIGS. 5 and 7 . Front roller 10 may be vertically adjustable as shown in FIGS. 5 and 7 . Several Verti-Drain models also have a rear roller (shown as 12 in FIGS. 2 , 3 and 4 ) positioned rearward of the plane of the main frame 6 and behind the tine heads 30 . On these Verti-Drain devices, the rear roller 12 rotates in a frame 13 , and the frame 13 is generally pivotally connected to the main frame 6 of the device (See FIG. 3 ).
Both the Verti-Drain and the Soil Reliever's main frame is connected to the tractor through a three point pick up harness on the device, generally consisting of two lower attachment points 100 rigidly connected to the main frame 6 and a top attachment point 101 also rigidly connected to the main frame 6 . See generally, FIGS. 1 , 5 and 8 . Powered adjustment arm 200 can be powered by the PTO, hydraulics or other means, and can include an intermediate arm positioned between the tractor powered adjustment arm and top attachment point (see FIGS. 8 and 12 ).
Lower attachment points connect pivotally to arms on the tractor, and top attachment point 101 also pivotally connects directly or indirectly to a powered adjustment arm 200 on the tractor. The top attachment point 101 of the three point harness, as shown in FIGS. 1 , 5 and 7 , consists of two splayed arms 101 a and a top rail 101 b . The two splayed arms 101 fixedly connect at one end to the lower main frame, and at the other end to the top rail 101 b . Top rail 101 b is rigidly attached between the top of the main frame 6 and the two splayed arms. Additionally stiffening of the top rail 101 a can be provided as shown in FIG. 12 . The splayed arms 101 a diverge from the top attachment point 101 to allow the PTO to attach therebetween, as shown in FIG. 5 . The top attachment point 101 of the harness thus forms a rigid structure located between the bottom and top of the main frame 6 , and has a coupling means 101 c (as shown, a pin, but other types of couplings could be used) to couple the top attachment point 101 to the tractor's powered adjustable arm 200 .
Hence, the aerator's three point harness is a rigid structure on the device but is pivotally mounted at the three connection points with the tractor or pulling vehicle. This three point harness is used in conjunction with the tractor's three point hitch system to raise and lower the aerator. When lowered or deployed, the aerator's front roller contacts the ground allowing the working end (the tines) to be placed in operational contact with the ground (shown in FIG. 6A ). When lifted, the entire aerator is lifted off the ground (as shown in FIG. 6B ) to allow for ease transportation of the aeration between working sites or locations.
The position of the working end of the device (the tine heads) with respect to the ground is set by adjusting the length of the pulling vehicles powered adjustment arm (or intermediary member) 200 . As this arm is shortened, the coupling point 101 c of the top rail 101 b to the powered adjustment arm 200 is drawn closer to the tractor, thereby raising the tine heads upwardly. As this powered adjustment arm 200 is lengthened, the coupling point 101 c of the top rail 101 b to the powered adjustment arm 200 is pushed further from the tractor, lowering the tine heads downwardly. If the tine head is not properly positioned with respect to the ground, entry angle and depth of penetration will be improper, as shown in FIG. 18 . Hence, to keep the times in proper position with respect to the ground when covering complex terrain; the tractor operator must constantly monitor and adjust the length of the top adjustment bar.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a turf aeration device which automatically adjusts position for changes in ground topography.
Yet another object of this invention is to provide a turf aeration device which can rotate away from the attachment points to the pulling vehicle.
It is an object of the invention to provide an aeration device having front and rear rollers connected in a rigid frame.
These and other objects and advantages of the present invention will no doubt become apparent to those skilled in the art after having read the following description of the preferred embodiment which are contained in and illustrated by the various drawing figures
Therefore, in a preferred embodiment, an improved turf aeration device is provided, where the aeration device is a frame having a journal led drive shaft, wherein the frame is attachable to a pulling vehicle having a power take-off portion; power transfer means, operatively attachable between the drive shaft and said power take-off portion, for transferring power from the power take-off portion to the drive shaft; and a plurality of aerator mechanisms operatively attached to the drive shaft and the frame. Each aerator mechanism comprises a link member, having a base and a distal end, wherein the base is pivotally attached to said frame; a tine holder, having at least one tine, pivotally attached to the distal end of the link member; a resilient means pivotally connected between the frame and said the holder; the improvement is a roller frame having fixedly attached to the main frame, and two rollers (or multiple wheels) attached rotatably to the roller frame, and a means to allow the aeration device to rotate away from the pulling device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view from the front end (the tractor end) of a prior art aerator device
FIG. 2 is a perspective detailed view of the rear section of the prior art aerator device.
FIG. 3 is a perspective rear view of a prior art aerator device detailing a rear roller.
FIG. 4 is another rear prospective view of the prior art aerator device detailing a rear roller.
FIG. 5 is a front view of a prior art aerator device detailing a front roller.
FIG. 6A is a rear perspective view of a prior art aerator device in transit position.
FIG. 6B is a rear perspective view of a prior art aerator device showing a front roller
FIG. 7 is a perspective view a prior art aerator device.
FIG. 8 is a schematic diagram of a prior art aerator device showing the rotation of the device.
FIG. 9 is a schematic side vie of the device in two different operational positions.
FIG. 10 is a schematic side view of the inventive device.
FIG. 11A is a schematic side view of the time head Camber adjustments.
FIG. 11B is a schematic side vie of the time head showing the operation of the spring system.
FIG. 12 is a top perspective view of the device showing the top spring an intermediate member.
FIG. 13 is a detail perspective view of the spring attachment to the frame.
FIG. 14 is a schematic side view with exploded detail of the top coupling means.
FIG. 15 is a detailed prospective view of the top coupling means.
FIG. 16 is a schematic side view showing the relative position of the device's components when positioned on a downward curved surface.
FIG. 17 is a schematic side view showing the relative position of the device's components when positioned on an upward curved surface.
FIG. 18 is a schematic side view of a prior art aerator device showing the relative position of the devices components when positioned on a flat surface (top), a downward curved surface (middle drawing) and an upward curved surface (bottom drawing).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings many details pertaining to fabrication and maintenance utility well established in the machine construction art and not bearing upon points of novelty are omitted in the interest of descriptive clarity and efficiency. Such details may include threaded connections, lockrings, shear pins, weld lines and the like. Unless otherwise specified, all parts are constructed of steel or of some other material suited to performing substantially the same function described herein.
Shown on FIG. 9 is one embodiment of the improved aeration device, shown pulled by a tractor. Aerator has a main frame 6 . Located on the main frame 6 , with a gearbox interfacing the PTO, drive shafts, drive links, aeration mechanism, and connecting rods substantially as shown in FIG. 3 of the '272 and a further description will not be repeated. As described in the '272 patent, it is preferred that the aeration mechanisms be dynamically balanced on drive shaft, and that the primary shafts exiting the gearbox connect to the driveshaft through a pair of chain and sprocket assemblies. As before, such an arrangement balances power application and the torquing forces.
Fixedly attached to main frame 6 near the frame bottom are two wings 400 (one on each side) in which front roller 401 and rear roller 402 are rotatably mounted (multiple wheels could be used instead of the two rollers, but such an embodiment is not as stiff). The rollers 401 , 402 and wings 400 creates a roller frame 404 , as shown, a rectangle shaped frame which is rigidly fixed with respect to the main frame 6 ; that is, the roller frame 404 does not pivot with respect to the main frame 6 . A pivoting roller frame 404 , while possible, is not preferred, as it would be difficult to control the entry angle of the tines. As the tines are located on arms connected to the main frame 6 , it is desired to be able to control the relationship of the main frame 6 to the ground. By allowing the roller frame 404 to pivot, this task becomes more complicated as the entry angle of the tines would vary (with respect to the ground tangent) with surface contour, an undesirable effect. However, the roller frame 404 could be adjustably connected to the main frame 6 , to allow for a fixed point of attachment, where the fixed attachment point could be varied as the job required.
To position the tine head 30 (and ultimately the tines) for proper placement in the ground, a compressive spring 40 is provided on a spring arm 41 located above each lower link 50 , as shown in FIG. 10 . Spring arm 40 has one end pivotally connected to the tine head 30 , and the other end pivotally connected to the main frame 6 . The spring 40 operates to resist compression and hence, pushes the spring arm 41 rearwardly. Positioned around the spring 40 is boot 501 , to protect the spring 40 from becoming clogged. Obviously, a hydraulic piston or shock could be used in place of spring 40 . The rest position of the tine head 30 occurs when the spring is fully extended and the spring 40 is free from external compressive forces (hence, a tine holder stop is not required as an earlier device). The location of the spring arm 41 above the lower link arm 50 is distinct from that shown in the '272 patent, where the spring was located below the lower link arm 50 and operated to restrain the tine holder 30 when subject to tension forces (stretching). It is not possible to use a spring 40 located underneath the lower link arm 50 when using a rear roller 402 positioned very close to the tine holders 30 , as the rear roller 402 would interfere with the operation of the spring. If the rear roller 402 is positioned behind the tine holder 30 , an underneath spring as disclosed in the '272 patent could be used. However, such an arrangement implies a larger roller frame 404 , which as will be discussed later, has disadvantages. Obviously, instead of a spring, other biasing means can be utilized, as well as the pantograph push device as disclosed in the '510 patent.
Also as shown in FIG. 11A , the end of the spring arm 41 has a series of holes 43 positioned therethrough for varying the positioned of the tine holder 30 with respect to the spring arm 41 , thereby allowing one to modify the “rest” position of the tine holder to set the entry angle of the tines as needed for the particular application. Additionally, it is desired to mount the spring in a separate attachable bracket 60 positioned on the frame, to allowed for ease of removal, as shown in FIG. 13 . The compression of the spring or biasing member for entry and exit of the tines is shown in FIG. 11B . As shown, the spring motion in combination with the aeration device's motion results in a pivoting of the buried tine, helping to fracture the ground, enlarging the bottom of the penetration hole.
The main frame 6 and roller frame 404 provides a rigid structure that will follow the ground contours provided that the entire main frame structure 6 is free to rotate away from or toward the tractor. While the current designs of attachment systems allows the aerator to pivot about the attachment points, the aeration is not free to rotate in the plane of the pulling direction (toward or away from the tractor). One possibility to provide the needed degree of freedom would be to disconnect the tractor's powered adjustment arm 200 from the top arm 101 b of the main frame's three point harness system 101 . In this fashion, the bottom of the main frame is allowed to pivot, and the top is free to rotate in the desired fashion: the main frame 6 is free to rotate about the lower attachment points 100 on the main frame 6 . Simply dispensing with this particular attachment point has drawbacks: the aerator cannot be placed in the raised position by action of the three point hitch system on the tractor. In this instance, upon raising the three point harness on the tractor, the aerator would flop downward (that is, it would continue to rotate rearwardly) without being lifted off the ground.
To provide for a limited range of rotation, the coupling means 101 C at the top attachment point 101 is modified to provide a means to provide limited rotation of the aeration device. As shown in FIG. 14 , the means provided includes a spring retainer 202 . The retainer 202 has a protruding plate 202 A with a series of openings to allow for bolting of the plate 202 A to a matching set of openings on a plate member 102 positioned on the distal end of the attachment point 101 . As shown, the openings in plate member 102 are located in a channel formed by two plates, more clearly shown in FIG. 15 . Bolted into this channel 102 is plate 202 A. The position of the spring retainer 202 can be shifted forward or rearwardly in response to the degree of rotation desired. As shown, plate 102 is angled to more closely align with the angle at which the power adjustment arm or intermediary member connects to the coupling means 101 C.
A spring arm 203 and spring 204 are positioned partially in the spring retainer 202 , as shown in the detail of FIG. 14 . The spring arm is essentially a member slidable on the frame in a direction toward or away from the tractor. The slidable member could be a pin, plate, shock, etc. The distal end of the spring arm 203 is threaded, to allow a nut to be placed on the arm as it protrudes from the spring retainer 202 . The near tractor end of the spring arm has a coupling joint 205 (as shown, aligned holes and a pin) to couple to the power attachment arm (or intermediary arm) of the tractor's three point hitch system to the spring retainer 203 .
In operation, as the tractor traverses over a valley, the main frame 6 and roller frame 404 will rotate forwardly (toward the tractor) as shown in FIG. 17 . Rotation is allowed by the spring retainer 202 moving forwardly with respect to the spring arm 203 , and results in compression of the spring 204 . The desired rotation could be achieved without use of the spring 204 (as the weight of the device is sufficient to provide for rotation) but the spring 204 helps damp the forces and prevents the spring arm 203 from slamming into the spring retainer 202 , potentially causing damage. As the tractor traverses over a ridge, the main frame and roller frame rotate rearwardly, reversing the operation, as shown in FIG. 17 .
The amount of allowed rotation depends on the length of the spring arm (as shown about 12 inches) and the mount location of the spring retainer 202 on the plate(s) 102 . Additionally, the ability of the frame 6 to follow the contours of the ground will depend upon the footprint of the roller frame 404 . For instance, a small roller frame 404 (as shown in FIG. 10 , the distance separating the rollers is about 27 inches) is more readily able to follow local features as opposed to a larger roller frame (say 48 inches, with the rear roller located behind the tine holder). While a larger roller frame 404 (including placing the roller in front of the tine heads are possible), it is preferred where features vary rapidly, such as on golf courses.
Although the present invention has been described in terms of specific embodiments, it is anticipated that alterations and modifications thereof will no doubt become apparent to those skilled in the art. For example, it will be understood that by keeping the top attachment point only a pivot point, and placing springs and spring arms at the bottom attachment points of the three point harness, comparable rotation of the frame is achieved (here rotation about the top attachment point). It is therefore intended that the following claims be interpreted as coveting all such alterations and modifications as fall within the true spirit and scope of the invention. | An improved turf aeration device is provided, where the device has a frame having a journalled drive shaft, and the frame is attachable to a pulling vehicle having a power take-off portion; where the device has a power transfer means, attachable between the drive shaft and the power take-off portion, for transferring power from the power take-off portion to the drive shaft; and a plurality of aerator mechanisms operatively attached to the drive shaft and the frame, each aerator mechanism having a lower link member, with a base end and a distal end, where the base end is pivotally attached to the frame; a tine holder pivotally attached to the distal end of the lower link member, where the improvement includes a roller frame rigidly attached to the frame, the roller frame having two spaced apart, and a slideable member adapted to allow limited rotation of the aeration device toward or away from the pulling device. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of evaluating an ion irradiation effect, a process simulator and a device simulator. More specifically, it relates to a method of evaluating an ion irradiation effect, which is distinctive in an arrangement for evaluating the effect of ion irradiation in ion implantation or ion etching with high accuracy, a process simulator and device simulator.
2. Description of the Related Art
The ion implantation technique has been used as a method of forming an impurity-doped region in a semiconductor device for a step of forming a source and a drain of a MOSFET, etc. Various simulation methods have been proposed for the purpose of estimating an impurity distribution resulting from ion implantation like this with high accuracy in advance (see e.g. JP-A-2004-079656).
There are various kinds of parameters for performing such simulation, which require numerical values measured in fact. For example, the distribution of an actual impurity concentration after ion implantation has been measured in reality by use of e.g. SIMS (Secondary Ion Mass Spectrometry) or the like.
In the case where SIMS is used to perform composition analysis of a thin film, etc., a standard sample composed of different materials alternately stacked into a multilayered form is used to calibrate the resolution of a direction of the depth, and the calibration is performed based on an ion intensity distribution of the standard sample.
However, some standard samples like this have a problem that because of having two or more layers of different materials, the samples have a so-called interface effect developed in the vicinity of an interface between the layers of different materials, which can expand or shrink an ion intensity distribution extraordinarily.
Hence, it has been proposed to use a standard sample which has alternately-stacked atomic layers of different isotopes, but common in element species (see e.g. JP-A-06-273289).
As for an isotope standard sample like this, isotopes are slightly different in atomic mass number, but entirely identical in chemical property. Therefore it has been reported that the interface effect and matrix effect disappear, and the resolution in a direction of the depth can be improved in accuracy.
On the other hand, a silicon (Si) substrate is damaged by ion implantation, and therefore the evaluation of such damage has been made by use of a channeling method in Rutherford backscattering spectrometry or a transmission electron microscope (see e.g. Journal of Applied Physics, Vol. 88, p. 3993, 2000).
Likewise, such damage will be caused in nanometer-scale ion beam machining by means of FIB (Focused Ion Beam) technique.
However, a conventional method of evaluating a damage has had a problem that it is difficult to quantitatively know the extent to which the silicon atoms in a portion damaged by ion irradiation are displaced.
Further, in the case of analysis by SIMS, a sample is analyzed while being etched by ions. Therefore, there has been a problem that it is difficult to evaluate what influences an effect by a physical force caused by ion etching, e.g. ion beam induced diffusion has on a composition distribution and a silicon lattice.
Therefore, the invention aims at evaluating an influence which ion irradiation exerts on atoms constituting a substrate with high accuracy.
SUMMARY OF THE INVENTION
A means for resolving the problems in association with the invention will be described with reference to FIG. 1 which is a view of assistance in explaining an arrangement according to the invention in theory.
The reference numeral 2 in the drawing represents a substrate such as a monocrystalline Si substrate.
Making a reference to FIG. 1 helps understand the means for resolving the problems.
Means 1
To resolve the above problems, the invention offers a method of evaluating an ion irradiation effect which is characterized by the following steps. The first is irradiating a sample 1 prepared by alternately and periodically stacking a plurality of thin film layers with a beam of ions 5 . The second is evaluating influence of the ions 5 used for the irradiation on atoms making up the sample 1 . In the method, of the plurality of thin film layers, the layer of at least one kind is composed of an isotope layer 3 .
As stated above, when a sample 1 including periodically arranged isotope layers 3 is used, it becomes possible to evaluate influence of ions 5 used for the irradiation on atoms making up the sample 1 based on distributions of isotopes, i.e. depth profiles of isotopes, with high accuracy.
Incidentally, the above patent document JP-A-6-273289 merely proposes a standard sample 1 for increasing the resolution of SIMS in a direction of the depth, and does not describe that some treatment is performed on the standard sample 1 , and the displacement of constituent atoms of the sample owing to the treatment is evaluated based on the changes in distributions of isotopes.
Means 2
Also, the method of evaluating an ion irradiation effect according to the invention stated in MEANS 1 is characterized in that the sample 1 includes two kinds of isotope layers 3 and 4 .
Use of the sample 1 including two kinds of isotope layers 3 and 4 as stated above enables influence of ion irradiation on atoms making up the sample 1 to be evaluated with high accuracy.
Incidentally, a typical example of the two kinds of isotope layers 3 , 4 in this case is a combination of a 28 Si layer and a 30 Si layer.
Means 3
Further, the method of evaluating an ion irradiation effect according to the invention stated in MEANS 1 is characterized in that the sample 1 is a sample which is prepared by alternately and periodically stacking two kinds of thin film layers, provided that the two kinds of thin film layers consist of a thin film layer of one kind composed of a layer having a natural composition ratio and a thin film layer of the other kind composed of an isotope layer 3 .
In the case where the thin film layer of one kind is an isotope layer 3 like this, the thin film layer of the other kind may be a layer having a natural composition ratio, which enables the reduction in the manufacturing cost of the sample 1 .
Incidentally, a typical example of the two kinds of thin film layers in this case is a combination of a Si layer having a natural composition ratio and a 28 Si layer.
Means 4
Still further, the method of evaluating an ion irradiation effect according to the invention stated in any one of MEANS 1 to 3 is characterized in that the step of ion irradiation is one of an ion implantation step and an ion etching step, and influence of ions 5 in the ion beam used for the irradiation on atoms making up the sample 1 is evaluated by means of secondary ion mass spectrometry.
As stated above, typical examples of the step of ion irradiation targeted for evaluation are an ion implantation step and an ion etching step. Evaluation of their influences by means of the secondary ion mass spectrometry can realize evaluation of such influences by a relatively untroublesome means for measurement.
As the secondary ion mass spectrometry per se carries ion etching, evaluation can be made with higher accuracy when the influence thereof is taken into account.
Means 5
Also, the invention offers a process simulator characterized in that characteristic values derived from evaluation according to the method of evaluating an ion irradiation effect of any one of MEANS 1 to 4 are stored as parameters in the process simulator.
As stated above, when the characteristic values derived from evaluation according to the above-described method of evaluating an ion irradiation effect are stored in the process simulator as parameters, a highly accurate process simulation taking into account the displacement of atoms resulting from the damage caused by ions, which has been unable to be evaluated conventionally, can be achieved.
Means 6
In addition, the invention offers a device simulator characterized in that characteristic values derived from evaluation according to the method of evaluating an ion irradiation effect of any one of MEANS 1 to 4 are stored in the device simulator as parameters.
As stated above, when the characteristic values derived from evaluation according to the above-described method of evaluating an ion irradiation effect are stored in the device simulator as parameters, a highly accurate device simulation taking into account the displacement of constituent atoms of a substrate resulting from the damage caused by ions, which has been unable to be evaluated conventionally, can be achieved. Particularly, in regard to a device having a hetero interface, e.g. the change in the mobility of a carrier owing to mixing of constituent atoms of a substrate can be evaluated with high accuracy.
According to the invention, it is made possible by using a sample having isotope atoms arranged regularly and measuring the change in depth profiles of the isotope atoms to simulate damages caused by ions including the displacement of constituent atoms with high accuracy, which have been unable to be evaluated conventionally.
Therefore, according to a method of evaluating an ion irradiation effect that the invention provides, a sample prepared by alternately and periodically stacking a plurality of thin film layers, of which a thin film layer of at least one kind is composed of an isotope layer, or typically a 28 Si n / 30 Si n sample (n represents the number of atomic layers constituting each layer) is irradiated with ions, followed by performing ion implantation or ion etching on the sample typically. Then, the influence of ions used for the irradiation on atoms constituting the sample is evaluated by e.g. the secondary ion mass spectrometry.
With a process simulator that the invention offers, characteristic values derived from evaluation according to the above-described method of evaluating an ion irradiation effect, e.g. values derived from evaluation of standard deviations of recoils of silicon atoms owing to ion irradiation are taken in the process simulator as parameters, whereby it becomes possible to quantitatively evaluate mixing of silicon atoms caused by ion irradiation and a thermal treatment after that.
Further, with a device simulator that the invention offers, characteristic values derived from evaluation according to the above-described method of evaluating an ion irradiation effect, e.g. values derived from evaluation of standard deviations of recoils of Ga, Al and In atoms in the vicinity of a hetero interface owing to ion irradiation are taken in the device simulator as parameters, whereby it becomes possible to quantitatively evaluate e.g. the change in the mobility of a carrier owing to mixing of constituent atoms of a substrate caused by ion irradiation and a thermal treatment after that.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of assistance in explaining an arrangement according to the invention in theory;
FIG. 2 is a schematic sectional view of a sample used in a method of evaluating mixing caused by ion implantation according to the first embodiment of the invention;
FIG. 3 is a view showing SIMS depth profiles of Si isotopes in a sample;
FIG. 4 is a view of assistance in explaining the distribution of an arsenic (As) concentration after ion implantation;
FIG. 5 is a view showing SIMS depth profiles of Si isotopes in the sample after implantation of As ions (10 13 cm −2 );
FIG. 6 is a view showing SIMS depth profiles of Si isotopes in the sample after implantation of As ions (10 14 cm −2 );
FIG. 7 is a view showing SIMS depth profiles of Si isotopes in the sample after implantation of As ions (10 15 cm −2 );
FIG. 8 is a view of assistance in comparing distributions of 28 Si and 30 Si concentrations before and after implantation of As ions;
FIG. 9 is a view of assistance in comparing the results of an experiment and a simulation concerning distributions of 28 Si and 30 Si concentrations after implantation of As ions;
FIG. 10 is a view of assistance in comparing the standard deviations σ(x) for the experimental result and a depth profile of recoil silicon atoms obtained from calculation by TRIM;
FIG. 11 is a view showing SIMS depth profiles of Si isotopes in the sample after implantation of boron (B) ions (10 15 cm −2 );
FIG. 12 is a view showing SIMS depth profiles of Si isotopes in the sample after implantation of B ions (10 16 cm −2 );
FIG. 13 is a view for comparison of sample evaluation between SIMS and Raman scattering;
FIG. 14 is a schematic sectional view of a sample used in the method of evaluating mixing caused by ion implantation according to the third embodiment of the invention; and
FIG. 15 is a view of assistance in explaining the dependence of substrate damage on an ion species used for irradiation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
A method of evaluating mixing caused by ion implantation according to the first embodiment of the invention will be described here with referring now to FIGS. 2 to 11 .
Referring to FIG. 2 , there is presented a schematic sectional view of a sample used in the method of evaluating mixing caused by ion implantation according to the first embodiment of the invention. On a Si buffer layer 12 of a natural composition ratio on a monocrystalline Si substrate 11 having a natural composition ratio with its (001) plane made a top surface, 30 Si 20 layers 13 each composed of twenty atomic layers and 28 Si 20 layers 14 each composed of twenty atomic layers are alternately stacked to e.g. fifteen cycles of the layers by means of molecular beam epitaxy.
In this case, the thickness of one atomic layer of each Si layer is about 0.136 nm, and therefore the thickness of one cycle of 28 Si 20 / 30 Si 20 is 5.4 nm approximately.
Incidentally, the abundances of silicon isotopes are as follows.
28 Si: 92.2%
29 Si: 4.7%
30 Si: 3.1%
However, for the purpose of making larger the mass ratio of isotopes, the isotopes, 28 Si and 30 Si are selected here.
Referring to FIG. 3 , there is presented a view showing SIMS depth profiles of Si isotopes in the sample. It can be seen from the drawing that 30 Si and 28 Si are alternately distributed with a cycle of about 5.4 nm.
Now, it is noted that in this SIMS analysis, secondary ions are analyzed while Cs+ ion is applied to the sample with an acceleration energy of 1 keV and an incident angle of 45 degrees, and individual abundances of the isotope ratio are normalized with respect to those of Si buffer layer 12 of the natural composition ratio. The conditions also apply to the cases stated below.
Referring to FIG. 4 , there is presented a view of assistance in explaining the distribution of an arsenic (As) concentration after ion implantation. As ions ( 75 As) 15 are implanted into the sample 10 with an acceleration energy of e.g. 25 keV and a dose systematically changed within a range of 10 13 to 10 15 cm −2 . In this case, the distribution of implanted As ions 15 has a peak at a position of about 20 nm from the surface.
Referring to FIG. 5 , there is presented a view showing SIMS depth profiles of Si isotopes in the sample after implantation of As ions (10 13 cm −2 ). Although some disorder arises at and in the vicinity of the surface, 30 Si and 28 Si are distributed regularly and alternately at a position below a depth of 5.4 nm from the surface. It can be seen that little mixing is caused under the condition of a dose of about 10 13 cm −2 .
Now, samples used for this SIMS analysis are unannealed ones, and this condition applies to the cases stated below.
Referring to FIG. 6 , there is presented a view showing SIMS depth profiles of Si isotopes in the sample after implantation of As ions (10 14 cm −2 ). In addition to some disorder arising at and in the vicinity of the surface, both 30 Si and 28 Si abundances are made smaller to a depth of about 40 nm from the surface. Therefore, it can be seen that mixing is caused.
Referring to FIG. 7 , there is presented a view showing SIMS depth profiles of Si isotopes in the sample after implantation of As ions (10 15 cm −2 ). It can be seen that the periodicities of 30 Si and 28 Si disappear completely to a depth of about 20 nm from the surface.
Referring to FIG. 8 , there is presented a view of assistance in comparing distributions of 28 Si and 30 Si concentrations before and after implantation of As ions. In the drawing, the data shown in FIGS. 3 and 7 are compared within a depth range of 4 to 46 nm from the surface.
Referring to FIG. 9 , there is presented a view of assistance in comparing the results of an experiment and a simulation concerning distributions of 28 Si and 30 Si concentrations after implantation of As ions. The result of simulation is overlaid on FIG. 3 and shown in the lower portion of the drawing.
An equation to draw the result of simulation in this case is given by the following expression (1), by which the displacement of atoms damaged by ion implantation can be evaluated by recreating the distribution C as-impla (x) of the concentration of each isotope after ion implantation by use of the convolution integral of the distribution C as-grown (x) of the concentration before ion implantation, provided that x represents a depth from the surface:
C as-impla ( x )= INT{C as-grown ( x ′)×[1/((2π) 1/2 ×σ)]×exp [−( x−x ′) 2 /2σ 2 ]dx ′} [x′=−∞→+∞] (1),
where σ( x )= k /[(2π) 1/2 ×c ]×exp [−( x−d ) 2 /2 c 2 ] (2).
As a matter of convenience of preparation of the specification, INT{A(x′)dx′=} [x′=−∞→+∞] means that the function A(x′) placed between a pair of braces is integrated with respect to x′ from −∞ to +∞.
Further, k, c and d are fitting parameters, and they are set in order to fit the simulation result to the experimental result plotted in the upper portion of the drawing as follow: k=80, c=13, and d=14.
Referring to FIG. 10 , there is presented a view of assistance in comparing the standard deviations σ(x) for the experimental result and a depth profile of recoil silicon atoms obtained from calculation by TRIM. The experimental result was obtained under the condition where the sample had been subjected to sheer ion implantation only without undergoing thermal treatment (i.e. annealing). Accordingly, in this case, the experimental result should match up to the result offered by a standard simulator [TRIM] which shows that ion irradiation causes silicon atoms of the substrate to be removed from lattice positions. In fact, FIG. 10 shows a good correlation between the results.
Thus, mixing of silicon atoms can be evaluated quantitatively based on the changes in intensities of Si isotopes obtained with SIMS.
Further, the distribution of displacement of Si after thermal treatment, which TRIM cannot offer, can be obtained because the structure is heated, and k, c and d are derived from fitting.
FIG. 9 shows the case where the dose is 10 15 cm −2 . However, the dependence of the degree of mixing on doses can be grasped quantitatively by simulating the degrees of mixing in cases of various doses and fitting the fitting parameters k, c and d to values which enable an experimental result to be recreated faithfully.
Referring to FIG. 11 , there is presented a view showing SIMS depth profiles of Si isotopes in the sample after implantation of B ions (10 15 cm −2 ). It can be seen that less mixing is caused in comparison to As ions.
In this case, the abundance of 28 Si higher than that of 30 Si in each periodic structure is not ascribable to the mixing, and it can be inferred that such relation of the isotope abundances results from the step of normalization with respect to the Si buffer layer 12 having the natural composition ratio.
Referring to FIG. 12 , there is presented a view showing SIMS depth profiles of Si isotopes in the sample after implantation of B ions (10 16 cm −2 ). It can be seen that mixing is caused to a depth of 40 nm from the surface.
Also, in this case, when the simulation is performed as stated above to determine the fitting parameters k, c and d so that an experimental result is recreated more accurately, substrate damage by implantation of B ions can be simulated with high accuracy.
Consequently, in regard to various kinds of ions, values of the fitting parameters k, c and d for each dose are stored in a process simulator, whereby substrate damage by ion implantation can be simulated with high accuracy, for example.
Also, it is possible to quantitatively evaluate the change in mixing in the course of various types of thermal treatments to be executed after ion implantation, based on the changes in distributions of 28 Si, 30 Si and the like.
Second Embodiment
Next, a method of evaluating mixing caused by ion implantation according to the second embodiment of the invention will be described with reference to FIG. 13 . The basic arrangement thereof is exactly the same as that for the first embodiment, and therefore only critical points thereof will be described here.
Referring now to FIG. 13 , there is presented a view for comparison of sample evaluation between SIMS and Raman scattering. Also, in this case, 28 Si 20 / 30 Si 20 isotope superlattice samples were measured.
The Raman scattering depth profiles of isotopes in the lower portion of the drawing exhibit much sharper interfaces in comparison to SIMS depth profiles of isotopes in the upper portion of the drawing, which shows that little mixing of 28 Si and 30 Si is caused at an interface between 28 Si 20 layer and 30 Si 20 layer.
The Raman scattering depth profile of an isotope has been known to have a high accuracy (see Thin Solid Films, Vol. 508, p. 160, 2006, as required). In contrast, it is thought that the SIMS depth profile of an isotope reflects a knock-on effect on silicon atoms caused by irradiation of Cs + ions in a step of SIMS.
Therefore, when SIMS depth profiles of the isotopes are corrected so as to recreate Raman scattering depth profiles of isotopes before ion implantation, the influence by irradiation of Cs + ions at the step of SIMS can be eliminated. As a result, a simulation about substrate damage by ion implantation can be performed with high accuracy.
Third Embodiment
Next, a method of evaluating mixing caused by ion implantation according to the third embodiment of the invention will be described with reference to FIG. 14 . The basic arrangement thereof is exactly the same as that for the first embodiment, and therefore only critical points thereof will be described here.
Referring to FIG. 14 , there is presented a schematic sectional view of a sample used in the method of evaluating mixing caused by ion implantation according to the third embodiment of the invention. On a Si buffer layer 22 of a natural composition ratio on a monocrystalline Si substrate 21 having a natural composition ratio with its (001) plane made a top surface, 28 Si 20 layers 23 each composed of twenty atomic layers and Si 20 layers 24 each composed of twenty atomic layers and having the natural composition ration are alternately stacked to e.g. fifteen cycles of the layers by means of molecular beam epitaxy.
In this case, the abundance of 30 Si in each layer is 0% approximately in 28 Si 20 layer 23 , and 3.1% in Si 20 layer 24 . Therefore, the following procedure may be followed. That is, the change in 30 Si distribution is measured by means of SIMS, and the fitting parameters k, c and d are determined so that the result of the measurement is recreated by the simulation with high accuracy.
As stated above, according to the third embodiment of the invention, as a 28 Si 20 /Si 20 superlattice sample is used as a sample, purified gaseous raw material of 30 Si is not needed, which enables significant reduction in the manufacturing cost of samples. As a result, the cost for a process of collecting data to be stored in the process simulator can be cut down, and therefore the process simulator can be supplied at a low cost.
Fourth Embodiment
Next, a method of evaluating mixing during the time of ion machining according to the fourth embodiment of the invention will be described with reference to FIG. 15 .
Referring to FIG. 15 , there is presented a view of assistance in explaining the dependence of substrate damage on an ion species used for irradiation. The upper portion of the drawing shows the mixing effect in the case where a 28 Si 20 / 30 Si 20 isotope superlattice sample, which is exactly the same as that used according to the first embodiment, is etched with O 2 + ions at an acceleration energy of 5 keV. The lower portion of the drawing shows the mixing effect in the case where the sample is etched with Cs + ions at an acceleration energy of 5 keV.
As is clear from the difference in amplitude between the profiles shown in the drawing, the mixing effect caused by O 2 + ions is larger than that owing to the mixing effect by Cs + ions. Also, in this case, the above-described simulation may be performed thereby to determine the fitting parameters k, c and d so as to recreate the result of measurement by SIMS with high accuracy.
Also, in this case, the abundance of 28 Si higher than that of 30 Si in each periodic structure is not ascribable to the mixing, and it can be inferred that such relation of the isotope abundances results from the step of normalization with respect to the Si buffer layer having the natural composition ratio.
When the dependence of substrate damage involved in such ion machining on the ion species is taken in the process simulator as the fitting parameters k, c and d, damage to a substrate by ion machining can be simulated with high accuracy.
Also, the comparison between the mixing effect caused by Cs + ions at an acceleration energy of 1 keV as shown in FIG. 3 and the mixing effect caused by Cs + ions at an acceleration energy of 5 keV as shown in the lower portion of FIG. 15 enables the acquisition of data concerning the dependence of substrate damage involved in ion machining on acceleration energies.
Therefore, when data on the dependence of substrate damage involved in ion machining on acceleration energies, i.e. the fitting parameters k, c and d for the respective acceleration energies, another ion mixing model, etc. are stored in the process simulator, it becomes possible to perform a process simulation with higher accuracy.
While the embodiments of the invention have been described above, the invention is not limited to the arrangements and conditions stated in the embodiments and various changes and modifications may be made. For example, as for the above-described embodiments, the number of atomic layers constituting each layer is set to twenty, however the invention is not limited to the twenty atomic layers, and a 28 Si n / 30 Si n or Si n / 30 Si n isotope superlattice sample having an arbitrary number n of atomic layers may be used.
In order to evaluate a damage owing to a low acceleration energy with higher accuracy, for example, the sample may be arranged under the condition of n<20. To evaluate a damage owing to a higher acceleration energy with higher accuracy, the sample may be arranged under the condition of n>20.
In addition, as for the embodiments, attention has been directed toward 28 Si and 30 Si as isotopes, a combination of 28 Si and 29 Si or 29 Si and 30 Si may be used.
Further, with the first embodiment, the result of measurement of a sample after ion implantation, but before annealing has been shown, the details of the description are common to the sample which has undergone annealing. That is, the mixing condition and distribution of As after annealing are measured, and the fitting parameters are determined so as to recreate the results of the measurement faithfully as far as possible, whereby a process simulation can be performed with higher accuracy.
Still further, with the above embodiments, the invention has been described assuming that it is applied to a Si process. However, the invention is also applicable to a device using SiGe layers. In that case, only Si contained in each SiGe layer may be regarded as making up an isotope superlattice structure. Otherwise, germanium (Ge) contained in each SiGe layer may be also regarded as making up a superlattice structure with the isotopes.
Incidentally, it is desirable to use 70 Ge and 76 Ge for the purpose of increasing the accuracy of SIMS analysis because the isotope abundances of Ge are as follows.
70 Ge: 20.5%
72 Ge: 27.4%
73 Ge: 7.8%
74 Ge: 36.5%
76 Ge: 7.8%
Further, the embodiments can apply to processes for III-V compound semiconductors of GaAs, etc. An isotope superlattice sample configured of ( 69 Ga 75 As) n /( 71 Ga 75 As) n may be used because the abundances of gallium (Ga) and arsenic (As) are as follows.
69 Ga: 60.1%
71 Ga: 39.9%
75 As: 100%
For example, as for an InGaAs-based field effect-type semiconductor device, the characteristic values derived from evaluation by the above-described method of evaluating an ion irradiation effect, e.g. fitting parameters determined by evaluating standard deviations of recoils of Ga, Al and In atoms in the vicinity of a hetero interface owing to ion irradiation are taken in the device simulator. As a result, it becomes possible to quantitatively evaluate the change in mobility of a carrier, the change in barrier height, etc. owing to the mixing of constituent atoms of a substrate caused by ion etching, ion implantation, and a subsequent thermal treatment.
A typical example of application of the invention is a process simulation in a semiconductor process. However, except a semiconductor device, the invention is also applicable to process simulations concerning damages to electronic devices caused by ions including damage to a superconducting device owing to ion milling. | Provided are a method of evaluating an ion irradiation effect, a process simulator and a device simulator, which allow the influence of ion irradiation on atoms making up a substrate to be evaluated with high accuracy. The method includes irradiating a sample with a beam of ions, and evaluating influence of the ions used for the irradiation on atoms making up the sample, provided that the sample is prepared by alternately and periodically stacking a plurality of thin film layers, and of the plurality of thin film layers, the layer of at least one kind is composed of an isotope layer. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to and the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 61/856,898 filed Jul. 22, 2013, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an apparatus to be used in the provision of medical services, particularly surgical procedures within adverse field environments.
[0003] When a person suffers a major injury, the immediate next hour is the “Golden Hour” in that the medical treatment received in the first sixty minutes to stabilize the injury and prevent further complications is usually critical in preventing loss of life or limb.
[0004] For soldiers, sailors, and airmen injured in battle, the initial medical treatment is usually “care under fire” provided by a medic or Navy corpsman as close as possible to the time and place of injury with whatever medical equipment the medic or corpsman carries on their person. The medic or corpsman's critical task is to stabilize the wound and assist in getting the wounded soldier to the nearest medical facility where doctors and surgeons provide more extensive treatment of the wound and stabilization of the wounded soldier before transferring them to a hospital.
[0005] In modern warfare, military doctors and/or forward surgical treatment units are located even closer to the battlefield to stabilize major wounds and save soldiers' lives as soon as possible after the time of injury. In Iraq and Afghanistan today, this often means a surgeon operating on a wounded soldier in a house, hotel, commercial building, tent, or even in the open at or near the time and place of injury. For a surgeon to work effectively on wounded soldiers under such conditions and save as many soldiers' lives as possible, the surgeon needs a platform to hold the stretcher (or litter in military terms) on which the wounded soldier is brought to them. This platform would function as an operating table in a hospital in raising or lowering the patient to whatever height the surgeon requires, tilting the stretcher as needed for various medical procedures, and supporting required equipment such as intravenous poles, surgical instrument trays, lights, patient arm boards, stirrups for lower extremity wounds, and other surgical equipment.
[0006] Thus it can be seen that there is a need for this means a portable, light-weight operating platform that can be carried by one person and erected quickly under adverse conditions at any location to allow surgeons to treat the wounded soldier as quickly and effectively as possible to stabilize their wounds and save their life.
[0007] A similar need exists in the non-military world in situations of mass casualties in natural or man-made disasters. Under normal situations when a civilian suffers major injury, they can be rushed by ambulance or helicopter to a nearby hospital for emergency shock trauma treatment. However, in the event of a mass casualty, roads can be impassable, local hospitals can be overwhelmed, and medical evacuation helicopters insufficient by the sheer number of injured people. In non-military mass casualty disasters as in warfare, the need is for a portable, light-weight operating table or platform than can be carried by one person and erected quickly under adverse conditions at any location to allow surgeons to treat critically injured people as quickly and effectively as possible to stabilize wounds and save lives.
[0008] Another critical problem and need is in the event of biological or chemical attack or “spill.” In this situation, hospitals with formal operating rooms in close proximity may be available, but to prevent contamination of hospitals and surgical operating theaters it will almost certainly be necessary to perform life-saving surgical procedures in a variety of buildings, tents, or other facilities away from the hospitals and other patient treatment facilities.
[0009] The objective of the present invention is to provide a novel apparatus for a portable, light-weight operating platform that can be carried by one person and erected quickly under adverse conditions at any location.
BRIEF SUMMARY OF THE INVENTION
[0010] Among the several objects of this invention may be noted the provision of an apparatus for, as described and shown herein, a folding, lightweight, portable, and rugged surgical operating platform that can be erected quickly, in one embodiment in less than one minute, under adverse conditions at any location and without tools. The basic platform includes no loose pieces that would require assembly or risk being lost in the field. In one embodiment, the platform weighs approximately thirty-four pounds and the platform and its parts and attachments can be folded up to dimensions of approximately 41 inches by 12 inches by 15 inches so that it can be carried by one person. It will hold, support, elevate, move, and tilt as needed a stretcher carrying a wounded person weighing well in excess of at least 400 pounds, including any desired portable surgical support equipment such as IV poles, surgical instrument trays, armboards, wrist restraints, leg stirrups, light poles, and other equipment that a surgeon needs to treat major injuries and save lives. For example, the platform is designed to allow IV poles to be mounted into all four corners of the platform and the platform side rails accept all surgical table accessories that mount on 5/16 inch by 1⅛ inch rails. In the medical field, rail mounted accessories are designed to be compatible with standard rails with these measurements as such the side rails provided will accommodate most standard accessories.
[0011] The platform provides a stable platform for surgery in a wide variety of emergencies and other situations where in-hospital surgical facilities are not readily available. Different users have different applications and requirements for how the platform is supported using the support members, which are outward-canted to provide strength and stability, such as whether or not wheels and rolling capability are required. For some users the need for ultimate lightweight portability combined with maximum platform stability dictates rigid mounted legs, and wheels and rolling capability are not required in such embodiments. In other embodiments, rigid mounted legs can be switched to wheels or vice versa without tools in less than 10 seconds per leg. Where mobility is required, mounting holes in the rigid mounted legs are drilled off-center so that when mounted on the outward-canted support members, caster spindles are vertical so that the casters function properly.
[0012] The height of the stretcher may, in one embodiment, be adjusted from 28 inches to 36 inches without tools to meet the surgeon's preference by moving the yolk arms up or down with the locking pin. The legs are individually adjustable, such that the platform can be height-adjusted and tilted from end to end, with up to about a 15 inch change in elevation from end to end. Likewise, legs may be adjusted from side to side if on a sloping surface. Preferably, adjustments may be made in less than five seconds using the mounting knob. Having the ability to tilt the platform from side-to-side toward the surgeon makes it easier for a surgeon to work on a wounded soldier or injured person without having to lean over the platform, and should reduce surgeon physical fatigue in day-long mass casualty situations.
[0013] In a preferred embodiment, all swiveling, sliding, and folding aluminum connections between structural elements are separated by ultra-low coefficient of friction virgin polytetrafluoroethylene (or Teflon®) or ultra-high-molecular-weight (UHMW) polyethylene spacers to prevent aluminum self-galling and seizing of mating surfaces, incorporate oil-impregnated bronze bushings, and are held together with stainless steel bolts and deformed-thread self-locking nuts tightened to prevent play.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which:
[0015] FIG. 1 is a side perspective view of an embodiment of a portable surgical platform according to the present invention in an unfolded, operational configuration carrying a litter in a substantially level position.
[0016] FIG. 2 is a side perspective view of a portable surgical platform according to the present invention in a fully folded, upright configuration.
[0017] FIG. 3 is a side perspective view of the portable surgical platform of FIG. 1 in an unfolded operational configuration carrying a litter in the “Trendelenburg” position.
[0018] FIG. 4 is a side perspective view of another embodiment of the portable surgical platform of the present invention in an operational configuration showing the attachment of a number of optional, standard operating table attachments.
[0019] FIG. 5 is an end perspective view of a portable field surgical platform according to the present invention in a partially unfolder configuration.
[0020] FIG. 6 is a detailed perspective view of the folding cross-bars between the support members and the locking brace of an embodiment of the portable surgical platform.
[0021] FIG. 7 is a detailed perspective view of a yoke and yoke arm of a portable surgical platform according to the present invention having a stretcher pole of the litter secured to the yoke.
[0022] FIG. 8 is a detailed perspective view of a yoke arm housing about a yoke arm wherein the spring-loaded pin is positioned within the yoke arm housing in a first vertical position to prevent movement of the yoke arm.
[0023] FIG. 9 is a detailed perspective view of a yoke arm housing about a yoke arm wherein the spring-loaded pin is positioned within the yoke arm housing in a second horizontal position to allow movement of the yoke arm.
DETAILED DESCRIPTION OF THE INVENTION
[0024] FIG. 1 is a side perspective view of one embodiment of a portable field surgical platform 118 according to the present invention in an unfolded, operational configuration. Portable surgical platform 118 comprises a rigid support structure, such as a pair of collapsible sides, such as elongated horizontal beams 109 , 110 (parallel horizontal beam 110 shown better in FIG. 4 ), supported by a plurality of support members 32 connected to and supporting the horizontal beams. The plurality of support members 32 are preferably arranged in corresponding, opposing pairs 32 a - 32 b , and 32 c - 32 d spaced apart along the length of the substantially parallel horizontal beams 109 , 110 .
[0025] When the platform 118 is erected for use, opposing pairs of support members 32 a - 32 b , and 32 c - 32 d are preferably connected to and rigidly braced apart by a pair of folding, pivotably connected cross-bars 3 , 4 , said cross-bars 3 , 4 held rigidly in place by means of a two piece locking brace 2 connected at either end to both of the cross-bars 3 , 4 , the two pieces of the locking brace 2 joined together, such as by a connecting link 1 . Connecting link 1 may be pulled to straighten the two pieces of the locking brace 2 between the cross-bars 3 , 4 . The cross-bars 3 , 4 connect to opposing support members 32 at either end, thereby connecting each pair of support members 32 a - 32 b and 32 c - 32 d together and acting as a brace to force the support members 32 apart and maintain the horizontal beams 109 , 110 substantially in parallel when the platform 118 is assembled for operation.
[0026] The horizontal beams 109 , 110 are both comprised of two or more submembers 111 , 112 , such as a first submember and second submember, each submember having an inboard and outboard end, connected by a pivoting hinge 114 that is held rigidly in either an open or unfolded position (shown in FIG. 1 ) or a folded position (shown in FIG. 2 ) by a locking means, such as a locking knob 115 or pins or other suitable means. When the platform 118 is unfolded and in its assembled configuration for operation, the pivoting hinge 114 allows the inboard ends of the submembers 111 , 112 to meet and align such that submembers 111 , 112 are substantially coplanar and form substantially straight horizontal beams 109 , 110 . As shown in FIG. 2 , when the platform 118 is folded into its folded or carrying configuration, pivoting hinge 114 allows submembers 111 , 112 to lie substantially parallel to each other, and defines an internal space between the submembers 111 , 112 , leaving room into which the support members 32 may also be folded substantially parallel to the submembers 111 , 112 .
[0027] Returning to FIG. 1 , when in operational position, the submembers 111 , 112 of horizontal beams 109 , 110 are substantially parallel and are axially aligned, i.e. have a common or substantially common longitudinal axis. In one embodiment, the pivoting hinge 114 is configurable to lock in the folded position, the unfolded operational position, or, preferably, both. The locking means 115 can be automatic, e.g. spring loaded, or manual. In another preferred embodiment, the pivoting hinge 114 is configured to lock automatically in the operational position via releasable internal spring loaded hooks. In one embodiment, releasable, manual latching clamps may be suitably used, such latching clamps (not shown) having a mechanical stop to prevent any unwanted reversal of the mechanism under strain, which locks the submembers 111 , 112 in position relative to each other.
[0028] As shown in FIGS. 5 and 6 , the “scissor” action of the pivotably-connected cross-bars 3 , 4 between the support members 32 allows the platform 118 to unfold for operational use, maintaining the beams 109 , 110 in parallel, and fold for carrying without the use tools (other than the users hands) or the need to connect any loose pieces to form the unitary platform 118 . Cross-bars 3 , 4 are connected at a centrally-located pivot point 26 . Portions 27 , 28 of the cross-bars 3 , 4 , are also have a hinge point 29 , 30 to allow the opposing pairs of support members 32 a - 32 b , and 32 c - 32 d , to be pushed together inwardly, collapsing the cross-bars 3 , 4 until, as shown in FIG. 2 , the cross-bars 3 , 4 lie substantially parallel with each other and with the support members 32 and submembers 111 , 112 of the beams 109 , 110 .
[0029] In one embodiment, an untrained person can erect the platform from the folded up stage to the operational position ready to receive the stretcher, and with only minimal instruction, the surgical platform of the present invention may be erected from the fully folded, carrying position to the operational position in about 60 seconds or less.
[0030] As shown in FIG. 6 , each support member 32 is unfolded and locked in position with cross-bars 3 , 4 . To provide additional stability, a two-piece locking brace 2 and connecting link 1 are provided to brace the support members 21 apart. In one preferred embodiment, the outer opposing ends of the locking brace 2 are connected at the hinge point 29 , 30 of the portions 27 , 28 of the cross-bars 3 , 4 . Connecting link 1 may be pulled to straighten the two pieces of the locking brace 2 between the cross-bars 3 , 4 . Preferably, connecting link 1 is snugly snap fit about the locking brace when in the straightened, locking position, but may be unsnapped by hand when the platform 118 is to be folded.
[0031] When locked in position, support members 32 a - 32 b and 32 c - 32 d are canted outward away from each other from the opposing ends 107 , 108 of the platform 118 . Support members 32 a - 32 b and 32 c - 32 d are preferably positioned at an angle Ω relative to the submember to which it is hingedly connected, said angle being greater than 90 degrees, but less than about 105 degrees from the corresponding submember 111 , 112 , which range includes all values and subranges therebetween. In the preferred embodiment shown in FIG. 1 , the individual support members 32 a - 32 b and 32 c - 32 d and submembers 111 , 112 , 98 , 99 (shown in FIG. 4 ) to which it is connected are locked at an angle, for the operational position, at an angle Ω of about 95 degrees relative to one another. This has the desirable result that pushing the platform 118 from one end will not allow the support members 32 to fold up because the outward slant of the support member 32 causes the platform 118 to lift rather than the support members 32 fold inward. As such, the heavier load on the platform 118 , the greater the resistance to the platform support members 32 a , 32 b , 32 c , 32 d inadvertently folding up.
[0032] A two piece locking brace 2 having a connecting link 1 is connected between the individual support members 32 a , 32 b , 32 c , 32 d and the outboard end of its corresponding submember 111 , 112 , 98 , 99 . Of course, alternate locking means (not shown), such as a tightening knob or pin, may be provided at the joint or pivot point at which a support member 32 a , 32 b , 32 c , 32 d is connected to its corresponding submember 111 , 112 , 98 , 99 .
[0033] As shown in FIG. 1 , support members 32 may be adapted to receive an interchangeable base, such as non-skid, self-leveling feet 55 , wheels 58 , casters (not shown), or a combination thereof. For example, all or only two of the support members 32 may have self-leveling feet 55 , or all or only two of the support members 32 may have wheels 58 . In the embodiment shown in FIG. 1 , the two support members 32 a , 32 b at one end of the platform 118 have wheels 58 affixed, and the two support members 32 c , 32 d at the opposing end have self-leveling legs 55 affixed to allow the platform 118 to be moved by a single individual from one end like a wheelbarrow. In the alternate embodiment shown in FIG. 4 , non-skid, self-leveling feet 55 have been affixed to all support members 32 .
[0034] Where wheels 58 are desired, as best shown in FIG. 3 , they may be mounted to the support members 32 by means of a releasable connecting device, such as a mounting knob 57 . Wheels 58 may also comprise a break, such as foot-operated break lever 104 , and a swivel lock, such as locking knob 106 , or other control mechanism. Wheels 58 may be formed from any suitable material, but to achieve the desired reduction in weight, the wheels 58 are preferably constructed of expanded foam.
[0035] In a preferred embodiment best shown in FIG. 4 , support members 32 further comprise leg extensions 43 , 44 , 45 , 46 which may be used to adjust the length of support members 32 (and thus the height of the platform 118 ) as desired.
[0036] Connected to the platform 118 proximate to each corner 100 , 101 , 102 , 103 of the platform 118 is a yoke 48 , 49 , 50 , 51 to adapted to receive the litter or stretcher poles 67 and lock the stretcher 113 to the platform 118 . In the preferred embodiment, a yoke 48 , 49 , 50 , 51 is carried upon a corresponding yoke arm 68 , 69 , 70 , 71 which is pivotably attached proximate to each outboard or distal end of the horizontal beams 109 , 110 so that the yoke arm 68 , 69 , 70 , 71 may be pivoted to a first position flat, lengthwise along the beam 109 , 110 when the platform 118 is in the folded position, or pivoted to a second position substantially perpendicular to the beam 109 , 110 when the platform 118 is unfolded to the operational position. As best illustrated in FIG. 7 , which is a close-up view of yoke 51 , yoke arm 70 , yoke arm hinge 66 , and a distal end of beam 109 , a yoke arm hinge 66 provides the pivot point for the attachment of yoke arm 70 and is configured so that the yoke arm 70 may only be pivoted when the end of the yoke arm 70 attached to the yoke 51 is fully extended away from the pivot point inside yoke arm hinge 66 . When the yoke arm 70 is pivoted to the second, perpendicular position relative to the beam 109 , the yoke arm 70 may then be adjusted by raising and lowering it vertically, to adjust the height of the yoke 51 relative to the beam 109 .
[0037] As better illustrated in FIGS. 8 and 9 , in order to place the yoke 48 , 49 , 50 , 51 in operational position, the user will lift the yoke arms 68 , 69 , 70 , 71 to the second position and secure them in place with a securing device, such as a cotter-pin (not shown) or a key ring 14 which engages a spring-loaded pin 18 that extends within the housing 19 of the yoke arm hinge 66 and that is sized to engage with any one of a plurality of slots 23 through the yoke arm 68 . For storage and shipping yoke arms 68 , 69 , 70 , 71 are pivoted to the first position and secured to the horizontal beams 109 , 110 with releasable connectors, such as snaps 8 (shown in FIG. 1 ), straps (not shown), latches (not shown) or mating pressure points (not shown).
[0038] As shown in FIG. 7 , the yokes 51 are suitably designed to accommodate and securely hold in place a stretcher poles 67 having a variety of thicknesses and/or geometrical cross-sections, with the standard stretcher pole 67 diameter being 1.5 inches and having a roughly circular cross-section viewed along the longitudinal axis. The yoke 51 may further comprise a hook (not shown), over-center latch clamp (not shown), or a strap 73 made of nylon, polypropylene, rubber, silicone, canvas or similar high-strength webbing, depending on user preference and requirements.
[0039] As best shown in FIG. 4 , the platform 118 is configured for the attachment of a wide variety of standard operating table attachments, such as, but not limited to, one or more telescoping IV pole 80 , armboard 90 , surgical instrument trays 62 , 63 77 , a folding lower shelf 36 (shown in FIG. 1 ), a fluid containment sheet 61 (shown in FIG. 1 ), and other surgical or medical equipment. Optionally, on each end of the horizontal beams 109 , 110 is a mounting fixture, such as hole 79 designed receive and adjustably secure a standard 0.5 inch or other diameter IV pole, light pole, or other 0.5 inch. One or a plurality of holes 79 having other diameters sized to receive any desired post (not shown) may also be provided about the perimeter of the platform 118 . In one embodiment, on the side of the horizontal beam 109 , 110 in communication with hole 79 is a threaded thumbscrew mounting bracket 78 that may be tightened or loosened to lock the IV pole 80 or other pole rigidly in place with a securing knob 82 , such as in case of an abrupt upward or downward movement of the platform 118 while being transported in a land vehicle or aircraft. In another embodiment, stainless steel tie downs (not shown) are located at each corner, individually rated to approx. 8,000-pound tensile strength.
[0040] Standard operating table attachments, such as folding equipment tray 62 may be mounted on in holes 79 provided about the perimeter of the platform 118 , or may be proved with a slide rail shuttle 34 that engages with slotted side rails 117 formed or attached substantially along the length of the horizontal beams 109 , 110 . Attachments are held in place using holes 79 , a tightening knob 88 on the slide rail shuttle (shown in FIG. 1 ), mounting arms 84 , or on brackets (not shown) at the head end of the platform 118 , or a combination thereof. One embodiment of the tray 62 is configured to support anesthetist's equipment 77 equipped with adjustable arms that are locked in place with a securing knob 83 . Trays 62 , 63 , 77 may be configured to fold at a hinge 86 as desired to both conserve space and prevent damage when being transported before attachment to the platform 118 . Trays 62 , 63 , 77 may desirably be made from stainless steel or other metal or reusable fiberglass trays. Brackets (now shown) may be provided to support a piece of medical equipment, such as, but not limited to, a ventilator, a vital signs monitor, a surgical piece of equipment, or an anesthetist piece of equipment.
[0041] FIG. 4 also shows optional armboards 90 , which may be attached to the platform 118 in the same manner as trays 62 , 63 , 77 . Preferably, armboards 90 are mounted on slide rail shuttles 34 and readily slide on the side rails 117 on the horizontal beams 109 , 110 , and optionally lock in position with a threaded screw knob 89 . The armboards 90 can be oriented flush in line with the longitudinal axis of the platform 118 as shown in FIG. 1 , or swivel outward or inward as shown in FIG. 4 at an angle relative to the beams 109 , 110 utilizing a pivoting mechanism 92 . A pivoting mechanism 92 allows the armboard 90 to be angled relative to the platform, between 0 and 180 degrees to support the patient's arm at whatever angle the surgeon wishes, or by swiveling out the surgeon's way entirely. This range includes all values and subranges therebetween. The armboard 90 may also be configured to angle up or down relative to the plane of the stretcher 113 using a sliding collar 94 adjustment. The armboard 90 may also be contoured to cradle the patient's arm. Optionally attached to each armboard 90 is, depending on use preference, either a VELCRO-type hook and loop fastener or a latching strap to restrain the patient's arm onto the armboard 90 .
[0042] As shown in FIG. 1 , a fluid containment sheet 61 made of PVC-coated fabric or comparable non-porous fabric may be suspended between the beams 109 , 110 below the stretcher 113 on hooks attached proximate to each corner 100 , 101 , 102 , 103 of the platform 118 . The fluid containment sheet 61 contains bodily fluids and other materials spilling through the stretcher 113 before and during surgery. In a preferred embodiment shown best in FIG. 3 , the fluid containment sheet 61 further comprises a drain 60 through which all such fluids are funneled into a collection container (not shown), such as a pan, tank, bag, or, preferably, a disposable bag filled with a mass of absorbent crystals.
[0043] FIG. 1 shows one embodiment of a folding lower shelf 36 , which may be optionally attached to the platform 118 . Folding lower shelf 36 may be configured such that it also acts as a reinforcing brace and structural member of the platform 118 when attached. Folding lower shelf 36 comprises an opposing pair of shelf bars 39 connected between support members 32 , preferably connected longitudinally between support members 32 on the same side of opposing ends of the platform 118 . The shelf bars 39 of the lower shelf 36 may be suitably made of 1 inch diameter aluminum tubing. Shelf bars 39 have a connecting link or hinge 52 and, similar to the two piece locking braces 2 , serve to hold the opposing support members 32 rigidly in place. The folding lower shelf 36 further comprises a tear-resistant, flame retardant polymer fabric 37 , such as double-extruded polyester fabric, stretched tightly between the shelf bars 39 . Use of a fabric 37 to form the lower shelf 36 allows the fabric to be more easily carried as a folded or rolled fabric, rather than having a relatively large and cumberson rigid lower shelf (not shown) to span the space created between the shelf bars 39 . When disconnected from the support members 32 and folded in half at the hinge 52 , the shelf bars 39 and fabric 37 can be rolled up together for transport or storage. The lower shelf 36 unfolds as shown and is attached by any suitable means, including a mounting bolt 38 in each of the four corners to a receiver bracket 42 with a retaining knob 47 on the inside of the support members 32 of the unitary platform 118 . Steel inserts may be suitably installed in the receiver brackets 42 such that the mounting bolts 38 of the folding lower shelf 36 thread into steel rather than relatively soft aluminum, thus avoiding deformation caused by overtightening. The lower shelf 36 may be configured to desirably support up to approximately 500 pounds, including all values and subranges therebetween.
[0044] The configuration of the platform 118 may vary significantly. In one embodiment, horizontal beams 109 , 110 may be 1 inch by 2 inch by ⅛ inch think aluminum tubing, such that it should be sufficiently rugged to stand up to heavy use in the field. The beams 109 , 110 may have any cross section, such as, but not limited to, square, rectangle, I-beam, trapezoidal, hexagonal, triangular, oval, circular, rounded, or any combination thereof. Although any cross section is possible, it has been found that beams 109 , 110 having rectangular or I-beam cross sections provide the best strength and nesting capabilities, while allowing for significant amounts of material to be removed as a weight-saving measure without sacrificing the requisite strength of the beams 109 , 110 . Material may be removed (and weight thereby reduced) by having a plurality of openings 12 in not only beams 109 , 110 , but also in substantially all structural elements of the platform 118 , including beams 109 , 110 , submembers 111 , 112 , 98 , 99 , support members 32 , leg extensions 43 , 44 , 45 , 46 , yoke arms 48 , 49 , 50 , 51 , cross-bars 3 , 4 and locking braces 2 . In one embodiment, the platform 118 will support at least 400 pounds without damage or permanent deflection. This range include all values and subranges therebetween. In one embodiment the platform 118 has been successfully test-loaded with over 600 pounds without damage or permanent deflection.
[0045] Any or all structural elements of the platform 118 , including beams 109 , 110 , submembers 111 , 112 , 98 , 99 , support members 32 , leg extensions 43 , 44 , 45 , 46 , yoke arms 48 , 49 , 50 , 51 , cross-bars 3 , 4 and locking braces 2 may be made from any suitable material so long as it is sufficiently durable and operates as shown and described herein. Some exemplary materials include, but are not limited to, aluminum, steel, titanium, bronze, composite alloys or other sturdy metals, polymers, carbon fiber, plastic, ceramics, material composites and combinations thereof. In one embodiment, any or all of the structural elements of the platform 118 , including beams 109 , 110 , submembers 111 , 112 , 98 , 99 , support members 32 , leg extensions 43 , 44 , 45 , 46 , yoke arms 48 , 49 , 50 , 51 , cross-bars 3 , 4 and locking braces 2 are resistant to corrosion. Additionally, all swiveling, sliding, and folding aluminum connections may be separated by ultra-low coefficient of friction virgin polytetrafluoroethylene (or Teflon®) or ultra-high-molecular-weight (UHMW) polyethylene spacers to prevent aluminum self-galling and seizing of mating surfaces, incorporate oil-impregnated bronze bushings, and held together with stainless steel bolts and deformed-thread self-locking nuts tightened to prevent play.
[0046] To facilitate the purpose of portability over large distances by a single individual which is a primary object of the invention, the platform 118 is preferably constructed from lightweight materials providing sufficient strength to be used as an operating table. Preferably, the unitary platform 118 weighs as little as possible. A preferred embodiment weight as little as about 45 pounds. When the unitary platform 118 is supplemented by the addition of optional equipment such as a lower shelf 36 , armboards 90 , and surgical instrument support trays 62 , 63 , 77 , the combined weight of the platform 118 and optional standard operating table attachments may weigh only up to about 60 pounds. As already noted, the platform 118 and any of its components may be suitably made from any material, including metal aluminum, steel, titanium, bronze, allow composite, polymer, carbon fiber, plastic, or combinations thereof.
[0047] In one embodiment, the platform 118 is readily and quickly height-adjustable to provide a comfortable working height for surgeons of various heights and personal operating preferences. In one embodiment, the height of the platform 118 may be adjusted over a range of about 6 to 28 inches from the lower end of the support members 32 to the yokes 48 , 49 , 50 , 51 , which range includes all values and subranges therebetween. The height may be adjusted by adjusting the connection of leg extensions 43 , 44 , 45 , 46 to support members 32 by making such connection at any one of the plurality of adjustment slots 96 positioned incrementally along the length of the leg extensions 43 , 44 , 45 , 46 . Any one of the support members 32 may be independently height adjustable from the other support members 32 . The height of the platform 118 may be adjusted such that the entire platform may be raised or lowered uniformly (i.e., all support members 32 and leg extensions 43 , 44 , 45 , 46 connected to have the same length), or one end may be raised or lowered, or one side may be raised or lowered as appropriate. Any means of making connections for the height adjustment may be used so long as it is sufficiently durable and has a raising and lowering function. Exemplary but non-limiting examples of height adjustment means include clamp, knob, friction fit, self-leveling ratchet type, screw type spring pin, and the like.
[0048] As discussed above in connection with FIGS. 7 , 8 and 9 , in addition to the height adjustment using the support member, the platform 118 may suitably include an independent adjustment means to allow for the raising or lowering of the stretcher 113 . Independent adjustment members such as yoke arms 68 , 69 , 70 , 71 , allow for the adjustment of the height of either end of the stretcher 113 above the beams 109 , 110 . By raising the height of the yoke arms 68 , 69 on one end of the platform 118 to a first height, but leaving the opposing yoke arms 70 , 71 at a different second height, the stretcher 113 may be tiled up to 25 degrees from end to end independently of the platform 118 , which range include all values and subranges therebetween. This independent adjustment suitably allows the movement of the patient into the “Trendelenburg” position, a common critical surgical procedure in which the patient is tiled head-down such that the patient's heart is higher than the brain.
[0049] FIG. 2 shows a side view of a portable field surgical platform 118 in a folded, upright configuration, according to the present invention. In this configuration, the platform 118 folds to fit into the space of a cube approximately 41″ by 12″ by 15″, but the present article should not be limited by size, so long as it is sufficient to support a stretcher 113 . This folded-up position is one position that allows for easy transport and stowage, for example, as it would be carried by one person manually, or in a land vehicle, emergency vehicle, ship, or aircraft.
[0050] FIG. 7 is a detailed view of one embodiment of a portable field surgical platform 118 wherein yoke 51 and yoke arm 70 are in a raised position. The stretcher 113 is dropped into place, and a metal hook (not shown) or folding strap 73 is placed over the stretcher pole 67 and fitted into a retaining bracket (not shown) on the back side of the yoke 51 . In cases where of a metal hook is used (not shown), the latch clamp locks in an over-center position with a force that may, for example, be adjustable by self-locking nuts (not shown) on the clamp. This clamp can also be spring-loaded to automatically spring open when unlatched or closed when receiving the stretcher pole 67 should surgeons so desire. FIG. 7 shows one embodiment of the platform with the stretcher 113 locked in place using a strap 73 , which may include one or more eyes, openings, or grommets to receive and engage a hook or post or it may include a VELCRO type closure, snaps, or buckle, or any combination thereof.
[0051] Although this invention has been disclosed and described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms is only by way of example and that numerous changes in the details of operation and in the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed. | A folding, lightweight, portable, and rugged surgical operating platform apparatus that can be erected quickly under adverse conditions at any location and without tools other than the users hands and without the need to attach any loose pieces to form the unitary platform. As needed, the surgical platform will hold, support, elevate, move, and tilt a stretcher (or litter in military terms) bearing a wounded person and the portable surgical support equipment such as IV poles, surgical instrument trays, armboards, wrist restraints, leg stirrups, light poles, and other equipment that a surgeon needs to treat major injuries and save lives. In the folded position, the platform takes up limited, uniform space for ease of portability by a single individual. Different users have different applications and requirements for how the platform is supported using stationary supporting legs or wheels when rolling capability are required. | 0 |
TECHNICAL FIELD
[0001] The present invention relates to suppression of disturbances in sound pressure frequency characteristics due to the cabinet shape of a speaker system.
BACKGROUND ART
[0002] In recent years, with reduction in the thickness of crystal liquid displays and practical application of organic EL, television sets have become thinner. At the same time, speaker systems for television sets have also become thinner. However, in a low-profile speaker system, the propagation direction of sound within a speaker cabinet is limited by its thinness, and effects of standing waves that occur between the opposing walls in the cabinet are larger than a conventional cuboid cabinet. This causes large peaks and troughs in sound pressure frequency characteristics of a speaker, system.
[0003] The speaker system disclosed in Patent Literature 1 is a related art to solve this problem. FIG. 13 is a cross-sectional view of the conventional speaker system disclosed in Patent Literature 1. The speaker system illustrated in FIG. 13 includes a cuboid speaker cabinet 60 , a speaker unit 63 , first acoustic tubes 64 a and 64 b, and second acoustic tubes 66 a and 66 b.
[0004] The speaker cabinet 60 includes a top board 61 a, a bottom board 61 b, and side boards 62 a, 62 b, 62 c, and 62 d. Sound absorbing materials 65 a and 65 b are provided at the openings of the first acoustic tubs 64 a and 64 b, respectively. Sound absorbing materials 67 a and 67 b are provided at the openings of the second acoustic tubs 66 a and 66 b, respectively.
[0005] The operations of a conventional speaker system configured as above will be described. When an electrical signal is inputted into the speaker unit 63 attached to the side board 62 b of the speaker cabinet 60 , sound is also emitted into the speaker cabinet 60 . At this time, standing waves occur between the top board 61 a and the bottom board 61 b opposed to each other in the longer direction of the speaker cabinet 60 . The standing waves occur at a frequency f 1 having a wavelength that is equal to a half of the distance between the top board 61 a and the bottom board 61 b.
[0006] Here, the first acoustic tubes 64 a and 64 b are provided at the corner parts between the side boards 62 a and 62 d, and between the side boards 62 a and 62 b of the speaker cabinet 60 , respectively. The first acoustic tubes 64 a and 64 b with end parts closed are perpendicular to the bottom board 61 b, maintain a gap X from the bottom board 61 b, and have the absorbing materials 65 a and 65 b at each opening. In addition, each length of the first acoustic tubes 64 a and 64 b is equal to one-fourth of the wavelength of standing waves which occur at the frequency f 1 . The first acoustic tubes 64 a and 64 b absorb and suppress the standing waves at the frequency
[0007] Likewise, standing waves occur at a frequency f 2 (twice the frequency f 1 ) having a wavelength that is equal to the distance between the top board 61 a and the bottom board 61 b. Standing waves at the frequency f 2 are suppressed by the second acoustic tubes 66 a and 66 b which are provided at the corner parts between the side boards 62 c and 62 b, and between the side boards 62 c and 62 d of the speaker cabinet 60 respectively, in the same configuration as the acoustic tubes 64 a and 64 b in the speaker cabinet. In this case, each length of the second acoustic tubes 66 a and 66 b is half length of the first acoustic tubes 64 a and 64 b (i.e., one eighth of the wavelength of standing waves at the frequency f 1 ).
[0008] As a result, the first acoustic tubes 64 a and 64 b suppress standing waves having a frequency 2n−1 times the frequency f 1 . Here, n=1, 2, 3 . . . . In addition, the second acoustic tubes 66 a and 66 b suppress standing waves having a frequency 2(2n−1) times the frequency f 1 . This reduces disturbance in sound pressure frequency characteristics due to the standing waves of the speaker cabinet 60 .
CITATION LIST
Patent Literature
[0000]
[PTL 1] Japanese Unexamined Patent Application Publication No. 2000-125387
[PTL 2] Japanese Unexamined Patent Application Publication No. 2009-55605
SUMMARY OF INVENTION
Technical Problem
[0011] However, in the speaker system disclosed in Patent Literature 1, the speaker cabinet 60 is required to have the first and second acoustic tubes 64 a, 64 b, 66 a, and 66 b of different lengths in order to suppress standing waves at the different frequencies f 1 and f 2 . Furthermore, in terms of the narrow internal space of the speaker cabinet 60 , it is also difficult to provide the first and second acoustic tubes 64 a, 64 b, 66 a, and 66 b of two different lengths within the low-profile speaker cabinet 60 .
[0012] In addition, a bass reproduction limit frequency depends on the internal capacity of the speaker cabinet 60 . In other words, it is advantageous to have a larger capacity of the speaker cabinet 60 . In this case, the internal capacities of the first and second acoustic tubes 64 a, 64 b, 66 a, and 66 b are also considered as a part of the capacity of the speaker cabinet 60 . However, since the first and second acoustic tubes 64 a, 64 b, 66 a, and 66 b have the absorbing materials 65 a, 65 b, 67 a, and 67 b respectively at each opening, a part of sound in the bass range passes through the absorbing materials 65 a, 65 b, 67 a, and 67 b. Therefore, damping effect by the absorbing materials 65 a, 65 b, 67 a, and 67 b is apparent in the bass range and this leads to a problem that sound pressure level is lowered in the bass range.
[0013] The present invention has been made in view of the above problems. Accordingly, an object of the present invention is to provide a speaker system that can suppress occurrence of standing waves without lowering sound pressure level in the bass range.
Solution to Problem
[0014] A speaker system in accordance with an embodiment of the present invention includes a speaker cabinet; a speaker unit which is installed in a wall surface of the speaker cabinet and outputs sound; and an acoustic tube having ends, one of which is open and the other of which is closed. The acoustic tube is provided inside the speaker cabinet such that a side wall surface of the acoustic tube crosses a direction in which standing waves propagates, the waves occurring inside the speaker cabinet.
[0015] The above placement of the acoustic tube can suppress standing waves at multiple frequencies which are caused by the relationship between the distance between the opposing walls within the speaker cabinet and a wavelength of sound emitted into the speaker cabinet. Moreover, in the bass range having lower frequencies than those at which standing waves occur, the capacity of the acoustic tube serves as a part of the capacity of the speaker cabinet and thus sound pressure level in the bass range is not lowered.
[0016] As an example, the speaker cabinet may be a pillar-shaped speaker cabinet that is greater in height than in width or depth. The acoustic tube may be provided inside the speaker cabinet so as to reduce an apparent height of an inside of the speaker cabinet.
[0017] As another example, the speaker cabinet may be a thin cuboid that is smaller in thickness than in length or breadth. The acoustic tube may be provided inside the speaker cabinet so as to reduce an apparent length in a longer direction of an inside of the speaker cabinet.
[0018] Moreover, the speaker cabinet may have a bass reflex port.
[0019] Moreover, a resonance frequency that is determined by an inductance component of an acoustic impedance of the acoustic tube and an acoustic compliance of the speaker cabinet may substantially be identical to a peak frequency of a sound pressure of the speaker unit which is installed in the speaker cabinet.
[0020] According to the above configuration, the resonance between the acoustic tube provided in the speaker cabinet and the internal space of the speaker cabinet can suppress the sound pressure peak of a resonance frequency f o of the speaker unit which is attached to the speaker cabinet. As a result, flat sound pressure frequency characteristics with fewer peaks and troughs can be obtained.
[0021] Moreover, the speaker system may be a bass reflex speaker system. The resonance frequency may substantially be identical to the peak frequency which is higher than a lowest resonance frequency of the speaker unit which is not installed in the speaker cabinet.
[0022] Moreover, the larger a band width of a sound pressure peak of the speaker unit is, the larger an ratio of an internal space capacity of the acoustic tube to an internal space capacity of the speaker cabinet may be.
[0023] Moreover, the acoustic tube may be formed of an inner wall surface of the speaker cabinet and partition boards that are connected to the inner wall surface.
[0024] Moreover, a sound absorbing material is provided at the closed end of said acoustic tube.
Advantageous Effects of Invention
[0025] A speaker system according to the present invention can suppress standing waves at multiple frequencies which are caused by the relationship between the distance between the opposing walls inside the speaker cabinet and a wavelength of sound emitted into the speaker cabinet. Moreover, in the bass range having lower frequencies than those at which standing waves occur, the capacity of the acoustic tube serves as a part of the capacity of the speaker cabinet and thus sound pressure level in the bass range is not lowered. As a result, a speaker system with high sound quality which has small disturbances in the reproduction sound pressure due to the standing waves can be made without lowering the sound pressure level in the bass range.
BRIEF DESCRIPTION OF DRAWINGS
[0026] FIG. 1A is a plan view of a speaker system in accordance with the first embodiment.
[0027] FIG. 1B is a cross-sectional view of a speaker system in accordance with the first embodiment.
[0028] FIG. 2 shows sound pressure frequency characteristics of a speaker system in accordance with the first embodiment.
[0029] FIG. 3A is a plan view of a speaker system in accordance with the second embodiment.
[0030] FIG. 3B is a cross-sectional view of a speaker system in accordance with the second embodiment.
[0031] FIG. 4 shows sound pressure frequency characteristics of a speaker system in accordance with the second embodiment.
[0032] FIG. 5A is a plan view of a speaker system in accordance with the third embodiment.
[0033] FIG. 5B is a cross-sectional view of a speaker system in accordance with the third embodiment.
[0034] FIG. 6 shows sound pressure frequency characteristics of a speaker system in accordance with the third embodiment.
[0035] FIG. 7 is an equivalent circuit diagram of a speaker system in accordance with the third embodiment.
[0036] FIG. 8 shows sound pressure frequency characteristics when changing the location of an absorbing material in a speaker system in accordance with the third embodiment.
[0037] FIG. 9 shows sound pressure distortion frequency characteristics of a speaker system in accordance with the first embodiment.
[0038] FIG. 10 is a cross-sectional view of a speaker system in accordance with the fourth embodiment.
[0039] FIG. 11 shows sound pressure frequency characteristics of a conventional bass reflex speaker system.
[0040] FIG. 12 shows sound pressure frequency characteristics when changing the capacity ratio of an acoustic tube of a speaker system in accordance with the fourth embodiment.
[0041] FIG. 13 is a cross-sectional view of a conventional speaker system.
[0042] FIG. 14 is a cross-sectional view of a conventional speaker system.
DESCRIPTION OF EMBODIMENTS
[0043] Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First Embodiment
[0044] FIGS. 1A and 1B show a speaker system in accordance with the first embodiment of the present invention. FIG. 1A is a plan view, partially cut-away, of the surface of the speaker system in accordance with the first embodiment. FIG. 1B is a cross-sectional view taken along the line A-B in FIG. 1A . The speaker system shown in FIGS. 1A and 1B includes a cuboid and low-profile speaker cabinet 1 , partition boards 8 a and 8 b provided within the speaker cabinet 1 , and a speaker unit 9 .
[0045] The speaker cabinet 1 includes a front board 2 , a back board 3 , side boards 4 and 5 in the longitudinal direction, and side boards 6 and 7 in the lateral direction. The speaker unit 9 is attached to the front board 2 of the speaker cabinet 1 . The partition board 8 a is connected with the front board 2 , the back board 3 , and the side board 6 in the lateral direction of the speaker cabinet 1 . On the other hand, the partition board 8 b is connected with the front board 2 , the back board 3 , and the side board 7 in the lateral direction of the speaker cabinet 1 . Furthermore, an acoustic tube 11 within the speaker cabinet 1 is formed of the partition boards 8 a and 8 b, the front board 2 , the back board 3 , and the side boards 6 and 7 . The acoustic tube 11 has one end (opening 12 ) open and the other end (end part 13 ) closed.
[0046] With reference to the sound pressure frequency characteristics in FIG. 2 , the operations of a speaker system configured as above will be described. When an electrical input is applied to the speaker unit 9 attached to the front board 2 of the speaker cabinet 1 , a diaphragm vibrates to emit sound. At the time, the sound emitted into the internal space of the speaker cabinet 1 is transmitted to the inside of the acoustic tube 11 which is formed of the partition boards 8 a and 8 b. Here, since the end part 13 of the acoustic tube 11 is closed, the sound in the speaker cabinet 1 is not emitted from the acoustic tube 11 into the outside of the speaker cabinet 1 .
[0047] Thus, the major difference between a conventional speaker system and a speaker system in accordance with the first embodiment is that the acoustic tube 11 is provided inside the speaker cabinet 1 . Therefore, the operations of the speaker system in accordance with the first embodiment will be described in comparison with a conventional closed-type and thin-profile speaker system.
[0048] Here, the measurements of the inside of the speaker cabinet 1 in accordance with the first embodiment illustrated in FIGS. 1A and 1B are 410 mm long, 210 mm wide and 10 mm thick. In addition, the electrodynamic speaker unit 9 has an aperture of 8 cm and a thickness of 12 mm. Furthermore, the partition boards 8 a and 8 b are both 180 mm long and the distance between each other is 30 mm.
[0049] In other words, the speaker cabinet 1 in accordance with the first embodiment is a cuboid that has a thin thickness measurement compared to length and width measurements. In other words, the ratio of the thickness measurement to the measurement of the longer direction (longitudinal direction) is 410/10=41. It is more preferable that the acoustic cabinet 11 be provided in the speaker cabinet 1 with the ratio of 10 or more, or more preferably 20 or more as follows.
[0050] The acoustic tube 11 in accordance with the first embodiment is provided so as to reduce the apparent length in the longer direction (longitudinal direction in this example) of the inside of the speaker cabinet 1 . In other words, the acoustic tube 11 is provided such that the side wall surface of the acoustic tube 11 (partition board 8 b ) and the propagation direction of standing waves which occur inside the speaker cabinet 1 (longer direction) cross each other or intersect at right angles.
[0051] In the speaker system shown in FIGS. 1A and 1B , the characteristic I in FIG. 2 indicates the sound pressure frequency characteristic of a conventional closed-type speaker system in the absence of the acoustic tube 11 . In this case, standing waves occur between the side boards 4 and 5 opposed to each other in the longer direction of the speaker cabinet 1 . This leads to a peak and a trough in sound pressure at around 400 Hz, i.e., a large disturbance to the sound pressure frequency characteristics.
[0052] Next, the operations of the speaker system when the acoustic tube 11 in accordance with the first embodiment is provided within the speaker cabinet 1 will be described. The acoustic tube 11 with one end open and the other end closed is formed of the partition boards 8 a and 8 b. The partition boards 8 a and 8 b are provided almost parallel with the side board 4 which is one side in the longer direction of the speaker cabinet 1 . In other words, the partition boards 8 a and 8 b are almost perpendicular to the direction of the mode of the standing waves which occur between the side boards 4 and 5 in the longer direction when the acoustic tube 11 is not provided.
[0053] As a result, the inside of the speaker cabinet 1 can be acoustically divided into the space where the acoustic tube 11 is provided and a back capacity 10 of the speaker unit 9 . Note that the back capacity 10 of the speaker unit 9 means the capacity of the space which excludes the space enclosed by the partition boards 8 a and 8 b (i.e., acoustic tube 11 ) from the internal space of the speaker cabinet 1 .
[0054] Thus, the sound from the speaker unit 9 is emitted into the back capacity 10 and then transmitted to the acoustic tube 11 . Here, since the partition boards 8 a and 8 b have a narrow distance of 30 mm therebetween, it is acoustically considered that the long and narrow acoustic tube 11 is attached to the back capacity 10 . More specifically, the acoustic tube 11 in accordance with the first embodiment is a sound path that is turned around by the partition boards 8 a and 8 b and the length is approximately 400 mm. The acoustic tube 11 is rectangular in cross section and when the tube viewed from cross section is considered as a circle, the diameter is approximately 20 mm.
[0055] Thus, both the back capacity 10 and the acoustic tube 11 are located between the side boards 4 and 5 opposed to each other in the longer direction of the speaker cabinet 1 . The characteristic II in FIG. 2 is a sound pressure frequency characteristic of the speaker system in accordance with the first embodiment. As is evident from the characteristic II, it is possible to remove the standing waves which occur at around 400 Hz when the acoustic tube 11 , as indicated by the characteristic I is not provided. On the other hand, although a resonance that occurs due to the newly provided acoustic tube 11 causes a small trough in sound pressure at around 250 Hz, this does not cause a large disturbance to the sound pressure frequency characteristics of the speaker system.
[0056] Furthermore, a peak and a trough in sound pressure at around 800 Hz which is twice 400 Hz can be found from a detailed analysis of the sound pressure frequency characteristics shown in FIG. 2 . The frequency is due to the standing waves equivalent to the frequency f 2 which is twice the frequency f 1 of 400 Hz recited in the reference 1. The characteristic II of the first embodiment shows a flat characteristic without a peak and a trough at around 800 Hz. In other words, it is clear that the acoustic tube 11 suppresses the standing waves not only at the frequency f 1 , but also at the frequency f 2.
[0057] Thus, according to the first embodiment, a speaker system with high sound quality can be made, which has very small disturbances in the sound pressure frequency characteristics due to the multiple standing waves which occur in the speaker cabinet 1 . Furthermore, unlike the reference 1, a sound absorbing material is not provided at the opening 12 of the acoustic tube 11 . Therefore, the sound in the speaker cabinet 1 is not damped by the sound absorbing material, thus preventing the decline in sound pressure level, especially in the bass range.
[0058] Note that as shown in FIGS. 1A and 1B , the sound absorbing material 100 may additionally be placed on the end part 13 of the acoustic tube 11 . Accordingly, when there is a large resonance at around 250 Hz due to the acoustic tube 11 , the placement of the sound absorbing material 100 can more effectively suppress the resonance and lead to flat sound pressure frequency characteristics (For the sound pressure frequency characteristic indicated by the characteristic II in FIG. 2 , the sound absorbing material 100 is not placed.) In this case, the sound absorbing material 100 is provided within the speaker cabinet 1 . However, since the sound absorbing material 100 is placed on the end part 13 which is the closed end of the acoustic tube 11 , only a small amount of sound passes through the end part 13 . Thus, there is only a slight decline in sound pressure level in the bass range due to the absorbing effects of the absorbing material 100 .
[0059] Note that although the acoustic tube 11 is provided near the side board 4 in the longitudinal direction, another acoustic tube may also be provided nearby the side board 5 which is opposed to the side board 4 . In this case, since both of the surfaces opposed to each other in the longitudinal direction have the acoustic tubes 11 , occurrence of standing waves is suppressed more effectively than when the acoustic tube 11 is provided on only one side.
[0060] Note that although the acoustic tube 11 is provided in the cuboid speaker cabinet 1 which has a thin thickness measurement compared to length and width measurements in the above example, placement of the acoustic tube 11 is not limited to a speaker cabinet of this shape. For example, an acoustic tube may be provided within a pillar-shaped speaker cabinet that has a tall height compared to width and depth measurements (the following embodiments are the same). In this case, the acoustic tube may be provided near the top or bottom board inside the speaker cabinet so as to reduce the apparent height of the inside of the speaker cabinet.
Second Embodiment
[0061] Next, FIGS. 3A and 3B show a speaker system in accordance with the second embodiment of the present invention. FIG. 3A is a plan view, partially cut-away, of the surface of the speaker system in accordance with the second embodiment. FIG. 3B is a cross-sectional view taken along the line C-D in FIG. 3A . The speaker system shown in FIGS. 3A and 3B includes a cuboid and low-profile speaker cabinet 20 , partition boards 27 a, 27 b, 27 c, and 29 , an acoustic tube 28 , an acoustic port 30 , and a speaker unit 31 attached to a front board 21 .
[0062] The speaker cabinet 20 includes a front board 21 , a back board 22 , side boards 23 and 24 in the longitudinal direction, and side boards 25 and 26 in the lateral direction. The partition board 29 is provided in parallel with the side board 25 . Furthermore, the acoustic port (bass reflex port) 30 is formed of the front board 21 , the back board 22 , the side board 25 , and the partition board 29 . In addition, the acoustic tube 28 with one end open and the other end closed is formed of the partition boards 27 a, 27 b, 27 c, and 29 , the front board 21 , the back board 22 , and the side boards 23 and 26 .
[0063] With reference to the sound pressure frequency characteristics in FIG. 4 , the operations of a speaker system configured as above will be described. The difference from the first embodiment is that a type of speaker system is changed from the closed type to the bass reflex type.
[0064] When an electrical input is applied to the speaker unit 31 attached to the front board 21 of the speaker cabinet 20 , a diaphragm vibrates to emit sound. At the time, the sound emitted into the internal space of the speaker cabinet 20 is transmitted to the inside of the acoustic tube 28 which is formed of the partition boards 27 a, 27 b, and 27 c. Here, since the end part of the acoustic tube 28 is closed, the sound in the speaker cabinet 20 is not emitted from the acoustic tube 28 into the outside of the speaker cabinet.
[0065] Although the operations above are the same as the first embodiment, in the bass reflex speaker system in accordance with the second embodiment, the speaker cabinet 20 includes the acoustic port 30 by providing the partition board 29 . In other words, sound pressure level in the bass range is higher than the first embodiment due to the acoustic resonance between the acoustic port 30 and the internal capacity of the speaker cabinet 20 .
[0066] In order to explain the effects of the second embodiment, sound pressure frequency characteristics of a conventional bass reflex speaker system which eliminates the acoustic tube 28 from the speaker cabinet 20 in FIG. 3A and FIG. 3B will be compared with those of a speaker system in accordance with the second embodiment. Thus, the major difference between the conventional speaker system and the speaker system in the second embodiment is that the acoustic tube 28 is provided inside the speaker cabinet 20 . Therefore, the operations of the speaker system in accordance with the second embodiment will be described in comparison with a conventional bass reflex and thin-profile speaker system.
[0067] Here, the measurements of the inside of the speaker cabinet 20 in accordance with the second embodiment are 410 mm long, 210 mm wide and 10 mm thick as same as the first embodiment. In addition, the electrodynamic speaker unit 31 has an aperture of 8 cm and a thickness of 12 mm. Furthermore, each of the partition boards 27 a, 27 b, and 27 c is 88 mm long and the distances between each other are 30 mm. Furthermore, the acoustic port 30 is 130 mm long.
[0068] In addition, the acoustic tube 28 is provided so as to reduce the apparent length in the longer direction (longitudinal direction in this example) of the inside of the speaker cabinet 28 . In other words, the acoustic tube 28 is provided such that the side wall surface of the acoustic tube 28 (partition board 27 c ) and the propagation direction of standing waves which occur inside the speaker cabinet 20 (longer direction) cross each other or intersect at right angles.
[0069] The characteristic III in FIG. 4 indicates a sound pressure frequency characteristic of the conventional bass reflex speaker system which does not include the acoustic tube 28 in the speaker system shown in FIGS. 3A and 3B . Since a resonance of the acoustic port 30 increases the sound pressure level at around 80 Hz in the characteristic III, it is clear that the effects of the bass reflex speaker system are obtained. On the other hand, standing waves occur between the side boards 23 and 24 opposed to each other in the longer direction of the speaker cabinet 20 , leading to a peak and a trough in sound pressure at around 360 Hz. This causes a large disturbance to the sound pressure frequency characteristics.
[0070] Next, the operations of the speaker system in accordance with the second embodiment, which has the acoustic tube 28 inside the speaker cabinet 20 , will be described. Each of the partition boards 27 a, 27 b, and 27 c is provided almost parallel with the side board 23 which is one side in the longer direction of the speaker cabinet 20 . In other words, the acoustic tube 28 with one end open and the other end closed are almost perpendicular to the direction of the mode of the standing waves which occur between the side boards 23 and 24 in the longer direction when the acoustic tube 28 is not provided.
[0071] As a result, the inside of the speaker cabinet 20 can be divided into the space where the acoustic tube 28 is provided, a back capacity 32 of the speaker unit 31 , and the acoustic port 30 . Note that the back capacity 32 of the speaker unit 31 means,the capacity of the space which excludes the acoustic tube 28 and the acoustic port 30 from the internal space of the speaker cabinet 20 . Thus, the sound from the speaker unit 31 is emitted into the back capacity 32 and then transmitted to the acoustic tube 28 and the acoustic port 30 .
[0072] Here, the partition boards 27 a, 27 b, and 27 c have a narrow distance of 30 mm therebetween as same as the first embodiment.
[0073] Therefore, it is acoustically considered that the acoustic tube 28 with the end part closed and the acoustic port 30 are attached to the back capacity 32 . More specifically, the acoustic tube 28 is approximately 480 mm. When the cross-section area of the acoustic tube 28 is considered as a circle, the diameter is approximately 20 mm. Thus, both the back capacity 32 and the acoustic tube 28 are provided between the side boards 23 and 24 opposed to each other in the longer direction of the speaker cabinet 20 .
[0074] The characteristic IV in FIG. 4 is a sound pressure frequency characteristic of the speaker system in accordance with the second embodiment. The standing waves which occur at around 360 Hz when the acoustic tube 28 is not provided, as indicated by the characteristic III in FIG. 4 can be suppressed. On the other hand, although there is a little resonance at around 270 Hz due to the newly-provided acoustic tube 28 , this does not cause a large disturbance to the sound pressure frequency characteristics of the speaker system. In other words, the speaker cabinet 20 allows for a speaker system with high sound quality.
[0075] In addition, in the characteristic in the absence of the acoustic tube 28 as indicated by the characteristic III in FIG. 4 , a trough in sound pressure occurs at the frequency f 2 of 700 Hz due to the second standing waves. The frequency f 2 is twice the frequency f 1 of 350 Hz of the first standing waves. However, as shown in the characteristic IV in accordance with the second embodiment, the sound pressure frequency characteristic at 700 Hz is flat. In other words, according to the second embodiment, multiple standing waves are suppressed by the acoustic tube 28 alone without the need of the first and second acoustic tubes 64 a, 64 b, 66 a, and 66 b of different lengths, which are provided in the reference 1 in accordance with the first and second standing waves.
[0076] Here, in order to improve sound pressure level in the bass range, the bass reflex speaker system uses an acoustic resonance of an acoustic compliance that is determined by the acoustic mass of the acoustic port 30 and the capacity of the speaker cabinet 20 . For reproduction in the lower bass range, it is necessary to increase the acoustic compliance of the speaker cabinet 20 , i.e., to increase the internal capacity of the speaker cabinet 20 .
[0077] In the second embodiment, since the acoustic tube 28 is provided within the speaker cabinet 20 , the acoustic capacity seems to be reduced. However, in the band which has lower frequencies than the band which has a longer wavelength than the equivalent length of the acoustic tube 28 (for example, a wavelength of 3.4 m at 100 Hz), the space of acoustic tube 28 can be considered a part of the capacity of the speaker cabinet 20 .
[0078] Therefore, the Internal capacity of the speaker cabinet 20 is the total capacity of the back capacity 32 of the speaker unit 31 and the capacity of the acoustic tube 28 . As a result, there is no difference from the capacity of the conventional bass reflex type speaker cabinet 20 in the absence of the acoustic tube 28 , and thus there are few differences in the bass range characteristics which are determined by the acoustic compliance of the speaker cabinet 20 and the resonance of the acoustic port 30 . Thus, it is possible to make a bass reflex speaker system that has fewer disturbances in sound pressure due to multiple standing waves which occur within the speaker cabinet 20 and that is able to reproduce rich bass sound.
[0079] In addition, since a sound absorbing material is not provided at the opening of the acoustic tube 28 in contrast to the reference 1, the sound in the speaker cabinet 20 is not damped by the sound absorbing material. Therefore, the sound pressure level does not decrease especially in the bass range.
[0080] Here, in order to provide a lower-profile speaker system, it is necessary to reduce the thickness of a speaker unit to be installed in the speaker system so as to fit a low-profile cabinet. The current mainstream speaker units are electrodynamic speaker units that obtain a driving force by gathering magnetic flux from a magnet around a voice coil.
[0081] However, with reduction in the thickness of an electrodynamic speaker unit, a magnet constituting its magnetic circuit is also made thinner, thus reducing magnetic energy of the magnet. This results in a smaller driving force to be generated in the voice coil and lower sound pressure level. In addition, for electrodynamic speaker units, the Q-value of the lowest resonance frequency is damped by electromagnetic damping resistance that is caused by a counter-electromotive force generated by vibration of the voice coil. Thus, the decrease in magnetic flux due to the reduction in the thickness of the magnet lowers the electromagnetic damping force and a large peak in sound pressure occurs in sound pressure frequency characteristics at around the lowest resonance frequency f OB of the speaker unit which is attached to a speaker cabinet. This degrades sound quality.
[0082] Furthermore, another type of low-profile speaker unit is a piezoelectric speaker unit. Unlike the electrodynamic speaker unit, the piezoelectric speaker unit does not have a magnetic circuit that gathers magnetic flux from a magnet, and bends a diaphragm by the expansion and contraction of a thin piezoelectric element in the form of a board to emit sound. This allows a significant reduction in the thickness compared to the electrodynamic speaker unit. However, for the piezoelectric speaker unit, it is difficult to suppress the Q value of a resonance of the diaphragm and thus a large peak in sound pressure occurs at around the lowest resonance frequency f OB . This disturbs sound pressure frequency characteristics of the speaker system and degrades sound quality as in the case of the electrodynamic speaker system with reduced magnetic energy of a magnet.
[0083] The speaker system disclosed in Patent Literature 2 is the known art to solve this problem. FIG. 14 is a cross-sectional view of the conventional speaker system recited in Patent Literature 2. The speaker system illustrated in FIG. 14 is a bass reflex speaker system that includes a loudspeaker cabinet 70 , an electrodynamic loudspeaker unit 71 , an acoustic resistance member 72 , and a bass reflex port 75 .
[0084] The operations of a conventional speaker system configured as above will be described. The sound from the rear of the diaphragm of the speaker unit 71 is emitted into the capacity 74 of the space enclosed by the rear of the diaphragm of the speaker unit 71 and the acoustic resistance member 72 after passing through the acoustic resistance member 72 from the volume 73 of the space enclosed by the acoustic resistance member 72 and the speaker cabinet 70 . At this time, the acoustic resistance member 72 damps the sound which passes through the acoustic resistance member 72 , thus dampening the vibration of the diaphragm of the speaker unit. This damps the sound pressure of the speaker system which is emitted from the front of the speaker unit. This damping effect flattens peaks and troughs in the sound pressure frequency characteristics of the speaker system.
[0085] In addition, as mentioned above, the speaker system disclosed in Patent Literature 1 has the first and second acoustic tubes 64 a, 64 b, 66 a, and 66 b, each of which has an opening at one end in order to prevent the standing waves, which occur in the opposing faces of the wall of the speaker cabinet 60 , from disrupting movements of the diaphragm of the speaker unit 63 and disturbing the sound pressure frequency characteristics. Furthermore, the sound absorbing materials 65 a, 65 b, 67 a, and 67 b which seal the openings separate the internal spaces of the first and second acoustic tubes 64 a, 64 b, 66 a, and 66 b from the internal space of the speaker cabinet 60 , respectively. Furthermore, each of the first and second acoustic tubes 64 a, 64 b, 66 a, and 66 b has a tube length of approximately 1/(2n) times the wavelength corresponding to the lowest resonance mode of the sanding waves to be generated along an inner wall surface of the speaker cabinet 60 , and the first and second acoustic tubes 64 a, 64 b, 66 a, and 66 b are provided such that the openings are located in the vicinity of nodal points of standing waves. Here, n is a natural logarithm of 2 or more. This suppresses the standing waves and flattens the sound pressure frequency characteristics of the speaker system.
[0086] However, the speaker system disclosed in Patent Literature 2 has a damping effect on the wide bass range from around the lowest resonance frequency f OB of the speaker unit 71 which is attached to the speaker cabinet 70 to around the resonance frequency f OP of the bass reflex port 75 . In particular, the vicinity of the resonance frequency f OP for the bass reflex port 75 of the speaker cabinet 70 is an important frequency band to obtain the sense of bass sound of the speaker system. The problem is a shortage of the sense of bass sound when the damping effect of the acoustic resistance member 72 suppresses into the sound pressure level around the resonance frequency f OP which is a bass reproduction limit.
[0087] In addition, in the speaker system disclosed in Patent Literature 1, the acoustic resonance of the first and second acoustic tubes 64 a, 64 b, 66 a, and 66 b suppresses the standing waves which occur in the speaker cabinet 60 to allow the diaphragm of the speaker unit 63 to easily move, thus flattening the trough in sound pressure. Therefore, peaks of sound pressure cannot be suppressed by controlling the movement of the speaker unit 63 at around the lowest resonance frequency f OB of the speaker unit 63 .
[0088] The third and fourth embodiments have been made in view of the above problems. Accordingly, objects of the third and fourth embodiments are to provide a speaker system which can flatten peaks of sound pressure of a speaker unit without lowering sound pressure level in the bass range.
Third Embodiment
[0089] FIGS. 5A and 5B show a speaker system in accordance with the third embodiment of the present invention. FIG. 5A is a plan view, partially cutaway, of the surface of a speaker system in accordance with the third embodiment. FIG. 5B is a cross-sectional view taken along the line E-F in FIG. 5A .
[0090] The speaker system shown in FIGS. 5A and 5B includes a speaker cabinet 41 , a piezoelectric speaker unit 44 , a drone cone 45 , an acoustic tube 46 , and a sound absorbing material 40 . The speaker cabinet 41 includes a front board 42 and a back board 43 . In addition, an acoustic tube 46 with one end (opening 48 ) open and the other end (end part 49 ) closed is formed of partition boards 47 a and 47 b. Furthermore, the sound absorbing material 40 is provided at the end part 49 of the acoustic tube 46 .
[0091] Here, the speaker system described above is designed such that the resonance frequency which is determined by an inductance component of an acoustic impedance of the acoustic tube 46 and an acoustic compliance of the speaker cabinet 41 is substantially identical to a peak frequency of sound pressure of the speaker unit 44 which is attached to the speaker cabinet 41 . The peak frequency at the time is higher than the lowest resonance frequency of the speaker unit 44 which is not attached to the speaker cabinet 41 . In other words, the peak frequency should nearly identical to the lowest resonance frequency f OB of the speaker unit 44 which is attached to the speaker cabinet 41 .
[0092] Note that the inductance component of the acoustic impedance of the acoustic tube 46 changes according to the length of the acoustic tube 46 or the cross-sectional area of the acoustic tube 46 . More specifically, the longer the length of the acoustic tube 46 , the larger the inductance component. In addition, the acoustic compliance of the speaker cabinet 41 changes according to the capacity of the speaker cabinet 41 . More specifically, the larger the capacity of the speaker cabinet 41 , the larger the acoustic compliance.
[0093] For example, the resonance frequency f 0 can be obtained from the following equation 1. Here, M denotes the inductance component of the acoustic impedance of the acoustic tube 46 and C denotes the acoustic compliance of the speaker cabinet 41 . In other words, the resonance frequency f 0 can be set to a given value by adjusting the length (or cross-section area) of the acoustic tube 46 and the capacity of the speaker cabinet 41 .
[0000]
[
Equation
1
]
f
0
=
1
2
π
1
MC
(
Equation
1
)
[0094] With reference to the sound pressure frequency characteristics in FIG. 6 and the equivalent circuit in FIG. 7 , the operations of a speaker system configured as above will be described. When an electrical input is applied to the speaker unit 44 attached to the front board 42 of the speaker cabinet 41 , a diaphragm vibrates to emit sound. At the time, the sound emitted into the internal space of the speaker cabinet 41 is transmitted to the drone cone 45 attached to the front board 42 of the speaker cabinet 41 . In addition, the sound from the rear of the speaker unit 44 is also transmitted to the acoustic tube 46 which is formed of the partition boards 47 a and 47 b. Here, since the end part 49 of the acoustic tube 46 is closed, the sound is not emitted from the acoustic tube 46 into the outside of the speaker cabinet.
[0095] The major difference between a conventional drone cone speaker system and a speaker system in accordance with the third embodiment is that the acoustic tube 46 is provided inside the speaker cabinet 41 . Therefore, the operations of the speaker system in accordance with the third embodiment will be described in comparison with a conventional drone cone speaker system.
[0096] Here, in the third embodiment illustrated in FIGS. 5A and 5B , the measurements of the inside of the speaker cabinet 41 are 360 mm long, 210 mm wide and 8 mm thick. The speaker unit 44 is 90 mm long and 50 mm wide. Furthermore, the drone cone 45 has almost the same external size as the speaker unit 44 .
[0097] The characteristic i in FIG. 6 shows a sound pressure frequency characteristic of the speaker system which does not include the acoustic tube 46 in the speaker system illustrated in FIGS. 5A and 5B , i.e., a conventional drone cone speaker system.
[0098] The bass reproduction limit of the characteristic i in FIG. 6 is extended up to around a resonance frequency f pp of 120 Hz between the mass of the drone cone 45 and an acoustic compliance of the internal space of the speaker cabinet 41 due to a resonance of the drone cone 45 . On the other hand, the peak of sound pressure at 200 Hz is caused by a resonance of the speaker unit 44 attached to the speaker cabinet 41 . The speaker unit 44 has a high Q value of resonance due to a resonance of the diaphragm. Thus, the peak of sound pressure at 200 Hz is approximately 15 dB higher than the sound pressure level in the band around 200 Hz. If this remains the same, sound quality of the speaker system is significantly degraded.
[0099] Next, the operations of the speaker system when the acoustic tube 46 in accordance with the third embodiment is provided within the speaker cabinet 41 will be described. Here, the length L of the partition boards 47 a or 47 b is 150 mm and the width W of the sound path is 50 mm. The acoustic tube 46 is turned around by the partition boards 47 a and 47 b. When sound is considered to pass through the edge of the partition board 47 a in an arc as shown in a broken line in FIG. 5A , the length of the sound path is approximately 410 mm. Therefore, a capacity Vb of the speaker cabinet 41 excluding a capacity Vh of 0.15 liters of the acoustic tube 46 is 0.45 liters.
[0100] FIG. 7 shows an equivalent circuit of the speaker system in accordance with the third embodiment. In FIG. 7 , F denotes a driving force. Zms denotes a machine impedance of the speaker unit 44 . Sd denotes an area of the diaphragm. Cb denotes an acoustic compliance of the capacity Vb of the speaker cabinet 41 . Zh denotes acoustic impedance when the acoustic tube 46 is viewed from the opening 48 . Cd denotes an acoustic stiffness of the drone cone. Md denotes an acoustic mass of the drone cone.
[0101] When viewed from the diaphragm of the speaker unit (piezoelectric speaker) 44 , the acoustic compliance Cb of the speaker cabinet 41 and an inductance component of the acoustic impedance of the acoustic tube 46 cause a resonance at around the resonance frequency f pp . As is evident from the equivalent circuit in FIG. 7 , this resonance is a parallel resonance. Therefore, when viewed from the diaphragm side of the speaker unit 44 , the acoustic impedance of the resonance is very high, thus significantly dampening the vibrations of the diaphragm of the speaker unit (piezoelectric speaker) 44 .
[0102] The characteristic ii in FIG. 6 is a sound pressure frequency characteristic when the acoustic tube 46 is formed of the partition boards 47 a and 47 b in the speaker cabinet 41 . The resonance between the acoustic compliance Cb of the speaker cabinet 41 and an inductance component of the acoustic impedance of the acoustic tube 46 significantly suppresses the peak of the sound pressure in the sound pressure frequency characteristic at around a frequency f pp of 200 Hz, when compared to the characteristic in the absence of the acoustic tube 46 , and causes a trough of around 6 dB.
[0103] Next, the characteristic iii in FIG. 6 shows a sound pressure frequency characteristic when the absorbing material 40 is provided near the end part 49 of the acoustic tube 46 . The absorbing material 40 relaxes the Q value of the resonance between the acoustic compliance Cb of the speaker cabinet 41 and the inductance component of the acoustic impedance of the acoustic 46 , leading to almost a flat sound pressure frequency characteristic at around 200 Hz, compared to when only the acoustic tube 46 is provided.
[0104] On the other hand, the acoustic tube 46 does not function as an acoustic tube in the bass range at the resonance frequency f pp of around 120 Hz between the mass of the drone cone 45 and the acoustic compliance of the speaker cabinet 41 . Therefore, the capacity Vh of 0.15 liters and the capacity Vb of 0.45 liters of the speaker cabinet 41 are added to make a total capacity of Vh and Vb. In other words, the capacity of the acoustic tube 46 is included in a capacity of a conventional drone cone speaker cabinet. Thus, the sense of bass sound is rarely in shortage in contrast to the Patent Literature 2 in which the acoustic resistance member 72 provided at the rear of the speaker unit 73 lowers the sound pressure level to around the frequency f op , which is the bass reproduction limit.
[0105] Here, the location of the absorbing material 40 in the acoustic tube 46 will be described. The case when the absorbing material 40 is provided at the end part 49 of the acoustic tube 46 as described in third embodiment will be compared with the case when the absorbing material 40 is provided at the opening 48 as disclosed in Patent Literature 2.
[0106] FIG. 8 shows the measurement result of sound pressure frequency characteristics of the speaker system, in almost the same configuration as the one shown in FIGS. 5A and 5B , (iv) when the acoustic tube 46 is not provided, (vi) when the absorbing material 40 is provided at the end part 49 of the acoustic tube 46 and (v) when the absorbing material 49 is provided at the opening 48 of the acoustic tube 46 .
[0107] With reference to FIG. 8 , in the characteristic iv in the absence of the acoustic tube 46 , a high peak of sound pressure occurs at around 200 Hz due to the resonance of the speaker unit 44 .
[0108] Next, in the characteristic v when the absorbing material 49 is provided at the opening 48 of the acoustic tube 46 , the frequency at which the peak of sound pressure occurs increases to around 250 Hz. Therefore, sound pressure cannot be flattened. In contrast, in the characteristic vi when the absorbing material 40 is provided at the end part 49 of the acoustic tube 46 , the peak of sound pressure at 200 Hz is suppressed and flat sound pressure frequency characteristic is achieved.
[0109] This result leads to a problem that the resonance frequency fluctuates when the absorbing material 40 is provided at the opening 48 , rather than the effects that the acoustic impedance of the acoustic tube 46 changes and suppresses the Q value of the resonance. In addition, when the absorbing material 40 is provided at the opening 48 of the acoustic tube 46 , damping effect of the absorbing. material 40 also lowers sound pressure level in the bass range at around 100 Hz. In other words, it is clear that locating the absorbing material 40 at the end part 49 of the acoustic tube 46 is an effective means of suppressing the Q value of the resonance of the speaker system in accordance with the third embodiment, but of not affecting reproduction of the bass range.
[0110] In addition, the effect of decreasing harmonic distortion in accordance with the third embodiment will be described. FIG. 9 compares a sound pressure frequency characteristic and second harmonic distortion characteristic in sound pressure as to when the acoustic tube 46 is not provided in the speaker cabinet 41 , and when the acoustic tube 46 is provided. In FIG. 9 , the characteristic vii shows a sound pressure frequency characteristic when the acoustic tube 46 is not provided. The characteristic viii shows a second harmonic distortion when the acoustic tube 46 is not provided. The characteristic ix shows a sound pressure frequency characteristic when the acoustic tube 46 is provided. The characteristic x shows a second harmonic distortion when the acoustic tube 46 is provided. Note that as mentioned above, the acoustic tube 46 suppresses the peaks of sound pressure at around 200 Hz.
[0111] Here, as to distortion characteristics, the second harmonic distortion having a peak of 45 dB at around 100 Hz occurs as indicated by the characteristic viii in absence of the acoustic tube 46 . However, by providing the acoustic tube 46 , the second harmonic distortion at around 100 Hz decreases by around 20 dB as indicated by the characteristic x.
[0112] This is a secondary effect of suppressing the peak of sound pressure at 200 Hz by a resonance between the acoustic tube 46 and the capacity of the speaker cabinet 41 . This is because the resonance between the acoustic tube 46 and the capacity of the speaker cabinet 41 dampens vibrations of sound pressure components at 200 Hz included in vibration components of the diaphragm at 100 Hz, i.e., vibrations of second harmonic components. This reduces the distortion at 100 Hz which is a bass reproduction limit and a speaker system with improved sound quality can be made.
[0113] Note that in the third embodiment, the acoustic tube 46 is formed by placing partition boards 47 a and 47 b between the front board 42 and back board 43 of the speaker cabinet 41 . However, the third embodiment is not limited to this configuration. When the separate acoustic tube 46 of any opening shape such as a round shape is provided in the speaker cabinet 41 , the same effects are obtained as the third embodiment.
Fourth Embodiment
[0114] Next, FIG. 10 shows a cross-sectional view of a speaker system in accordance with the fourth embodiment. The speaker system illustrated in FIG. 10 includes a speaker cabinet 50 , an electrodynamic speaker unit 51 , a bass reflex port 52 , an acoustic tube 53 , and a sound absorbing material 56 . The acoustic tube 53 with one end (opening 54 ) open and the other end (end part 55 ) closed has the absorbing material 56 at the end part 55 .
[0115] The operations of a speaker system configured as above will be described. The differences from the third embodiment are that the piezoelectric speaker unit 44 is replaced by the electrodynamic speaker unit 51 , and that the drone cone 45 is replaced by the bass reflex port 52 .
[0116] The change from the drone cone 45 to the bass reflex port 52 does not dramatically change the operations of the speaker system. A resonance is caused by an acoustic compliance of an internal space 57 of the speaker cabinet 50 and the acoustic mass of the bass reflex port 52 , and a bass reproduction range is extended. This is a basic function of a bass reflex speaker system as same as the third embodiment.
[0117] On the other hand, unlike the piezoelectric speaker unit 44 , the Q value of the lowest resonance frequency is suppressed by electromagnetic damping resistance in the electrodynamic speaker unit 51 . However, the electromagnetic damping resistance is inversely proportional to the square of the product of a length of a voice coil L and a magnetic flux density B, (BL) 2 . Therefore, when a magnet of a magnetic circuit constituting the electrodynamic speaker unit 51 becomes smaller, the magnetic flux density B also becomes smaller. Thus, damping of the Q value is no longer effective.
[0118] FIG. 11 shows sound pressure frequency characteristics of a bass reflex speaker system that includes the 8-cm-aperture electrodynamic speaker unit 51 which is attached to the speaker cabinet 50 having an internal capacity of 1 liter. The characteristics are calculated by changing the value of BL. Here, as constants for the 8-cm-aperture speaker, the vibration mass is 4.5 g, a voice coil impedance is 8Ω, an effective radius of the diaphragm is 30 mm.
[0119] In FIG. 11 , BL=6 in the characteristic (a), BL=4 in the characteristic (b), and BL=2 in the characteristic (c). When BL=6, the electromagnetic damping resistance is large. Therefore, the sound pressure frequency characteristic at around 200 Hz which corresponds to the resonance frequency f OB of the speaker unit 51 attached to the speaker cabinet 50 is almost flat. On the other hand, when BL=2, there is a shortage of damping of the Q value of the resonance and a sound pressure peak of around 10 dB occurs at around 200 Hz. Even though such a speaker is in shortage of damping of the Q value due to small BL, when the acoustic tube 53 is provided within the speaker cabinet 50 as described in the fourth embodiment illustrated in FIG. 10 , the same effects as the third embodiment can be obtained. In other words, vibrations of the diaphragm of the electrodynamic speaker unit 51 can be suppressed by a resonance between an acoustic compliance of the capacity Vb of the internal space 57 of the speaker cabinet 50 which excludes the capacity Vh of the acoustic tube 53 and an inductance component of an acoustic impedance of the acoustic tube 53 . In addition, the absorbing material 56 which is provided at the end part 55 of the acoustic tube 53 can achieve flat sound pressure frequency characteristics.
[0120] Here, the relationship between the capacity Vh of the acoustic tube 53 and the capacity Vb of the internal space 57 of the speaker cabinet 50 which excludes the capacity Vh of the acoustic tube 53 will be described. The peaks of sound pressure at around 200 Hz can be suppressed by a resonance between an acoustic compliance of the capacity Vb of the internal space 57 of the speaker cabinet 50 and an inductance component of an acoustic impedance of the acoustic tube 53 . The tube diameter and the tube length of the acoustic tube 53 can be set to any value.
[0121] The longer the tube diameter and tube length of the acoustic tube 53 , the larger the capacity Vh of the acoustic tube 53 . This means the smaller capacity Vb of the internal space 57 of the speaker cabinet 50 which excludes the capacity Vh of the acoustic tube 53 . FIG. 12 shows sound pressure frequency characteristics when changing the ratio Vh/Vb of the two capacities described above from 0.2 to 0.5 to 0.8. In FIG. 12 , in order to clarify the effects of the acoustic tube 53 , the absorbing material 56 is not provided at the end part 55 of the acoustic tube 53 .
[0122] In FIG. 12 shows sound pressure frequency characteristics. A characteristic (d) shows when the acoustic tube 53 is not provided. A characteristic (e) shows when Vh/Vb=0.2. A characteristic (f) shows when Vh/Vb=0.5. A characteristic (g) shows when Vh/Vb=0.8 The larger the ratio Vh/Vb, i.e., the larger the ratio of the capacity of the acoustic tube 53 to that of the speaker cabinet 50 by increasing the tube diameter or tube length of the acoustic tube 53 , the larger the frequency band width of the trough of sound pressure. Therefore, the ratio Vh/Vb may be determined in accordance with a frequency band width of a sound pressure peak of the electrodynamic speaker unit 51 . For instance, it is preferable that the larger the band width of the sound pressure peak of the speaker unit 51 , the larger the ratio of the internal space capacity of the acoustic tube 53 to that of the speaker cabinet 50 .
[0123] The embodiments described above can independently be implemented or may optionally be combined.
[0124] Although the embodiments of the present invention have been described with reference to the drawings, the present invention is not limited to the above-illustrated embodiments. Various kinds of modifications and variations may be added to the illustrated embodiments within the same or equal scope of the present invention.
INDUSTRIAL APPLICABILITY
[0125] The present invention can be used in a wide variety of applications especially as a speaker system for television sets and mobile computers which have become thinner or as a speaker system for cars and others.
REFERENCE SIGNS LIST
[0000]
1 , 20 , 41 , 50 , 60 , 70 speaker cabinet
2 , 21 , 42 front board
3 , 22 , 43 back board
4 , 5 , 6 , 7 , 23 , 24 , 25 , 26 , 62 a, 62 b, 62 c, 62 d side board
8 a, 8 b, 27 a, 27 b, 27 c, 29 , 47 a, 47 b partition board
9 , 31 , 44 , 51 , 63 , 71 speaker unit
10 , 32 back capacity
11 , 28 , 46 , 53 acoustic tube
12 , 48 , 54 opening
13 , 49 , 55 end part
30 acoustic port
45 drone cone
61 a top board
61 b bottom board
64 a, 64 b first acoustic tube
40 , 56 , 65 a, 65 b, 67 b, 100 absorbing material
66 a, 66 b second acoustic tube
72 acoustic resistance member
73 volume
74 capacity
52 , 75 bass reflex port | A speaker system includes: a speaker cabinet; a speaker unit installed in a wall surface of said speaker cabinet; and an acoustic tube having ends, one of which is open and the other of which is closed, in which said acoustic tube is provided in said speaker cabinet such that a side wall surface of said acoustic tube crosses a direction in which standing waves propagates, the waves occurring inside said speaker cabinet. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 12/708307, filed Feb. 18, 2010, which is a continuation of U.S. patent application Ser. No. 10/524,809, filed on Feb. 15, 2005, which is a national phase of International Patent Application No. PCT/US03/02594, filed Aug. 19, 2003, published on Feb. 26, 2004 as International Patent Publication No. WO 04/017381, which claims priority from U.S. Application No. 60/404,447, which was filed on Aug. 19, 2002, each of which are incorporated by reference in their entireties herein, and from which priority is claimed.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to semiconductor processing methods, and more particularly, to methods for making semiconductors materials in a form suitable for fabrication of thin-film transistor (“TFT”) devices,
[0003] Flat panel displays and other display units are used as visual imaging interfaces for the common and ubiquitous electronic devices and appliances such as computers, image sensors, and television sets. The displays are fabricated, for example, from thin films of liquid crystal and semiconductor material placed on glass or plastic substrates. Each display is composed of a grid (or matrix) of picture elements (“pixels”) in the liquid crystal layer. Thousands or millions of these pixels together create an image on the display. TFT devices fabricated in the semiconductor material layer are used as switches to individually turn each pixel “on” (light) or “off” (dark). The semiconductor materials used for making the TFTs, traditionally, are amorphous or polycrystalline silicon thin films. These films are deposited on to the substrates by physical or chemical processes at relatively low deposition temperatures in consideration of the low melting temperatures of the substrate materials used (e.g., glass or plastic). The relatively low deposition temperatures degrade the crystallinity of the deposited silicon films and cause them to be amorphous or polycrystalline.
[0004] Unfortunately, the device characteristics of a TFT fabricated in a silicon thin film undesirably degrade generally in proportion to the non-crystallinity of the silicon thin film. For industrial TFT device applications, silicon thin films of good crystalline quality are desirable. The crystallinity of a thin film of silicon deposited at low temperatures on a substrate may be advantageously improved by laser annealing. Maegawa et al. U.S. Pat. No. 5,766,989, for example, describes the use of excimer laser annealing (“ELA”) to process amorphous silicon thin films deposited at low temperatures into polycrystalline silicon thin films for LCD applications. The conventional ELA processes, however, are not entirely satisfactory at least in part because the grain sizes in the annealed films are not sufficiently uniform for industrial use. The non-uniformity of grain size in the annealed films is related to the beam shape of the laser beam, which is used in the ELA process to scan the thin film.
[0005] Im et al. U.S. Pat. No. 6,573,531 and Im U.S. Pat. No. 6,322,625 (hereinafter “the '531 patent” and “the '625 patent”, respectively), both of which are incorporated by reference herein in their entireties, describe laser annealing apparatus and improved processes for making large grained polycrystalline or single crystal silicon structures. The laser annealing processes described in these patents involve controlled resolidification of target portions of a thin film that are melted by laser beam irradiation. The thin film may be a metal or semiconductor material (e.g., silicon). The fluence of a set of laser beam pulses incident on the silicon thin film is modulated to control the extent of melting of a target portion of a silicon thin film. Then, between the incident laser beam pulses, the position of the target portion is shifted by slight physical translation of the subject silicon thin film to encourage epitaxial lateral solidification. This so-called lateral solidification process advantageously propagates the crystal structure of the initially molten target portion into grains of large size. The apparatus used for the processing includes an excimer laser, beam fluence modulators, beam focussing optics, patterning masks, and a motorized translation stage for moving the subject thin film between or during the laser beam irradiation. (See e.g., the '531 patent, FIG. 1, which is reproduced herein).
[0006] Consideration is now being given to ways of further improving laser annealing processes for semiconductor thin films, and in particular for recrystallization of thin films. Attention is directed towards apparatus and process techniques, with a view to both improve the annealing process, and to increase apparatus throughput for use, for example, in production of flat panel displays.
SUMMARY OF THE INVENTION
[0007] The present invention provides systems and methods for recrystallizing amorphous or polycrystalline semiconductor thin films to improve their crystalline quality and to thereby make them more suitable for device applications. The systems and processes are designed so that large surface area semiconductor thin films can be processed quickly.
[0008] Target areas of the semiconductor thin film may be intended for all or part semiconductor device structures. The target area may, for example, be intended for active regions of the semiconductor devices. The target areas are treated by laser beam irradiation to recrystallize them. The target areas are exposed to a laser beam having sufficient intensity or fluence to melt semiconductor material in the target areas. A one shot laser beam exposure may be used—the melted semiconductor material recrystallizes when the laser beam is turned off or moved away from the target area.
[0009] A large number of target areas in a region on the surface of the semiconductor thin film may be treated simultaneously by using laser radiation that is patterned. A projection mask can be deployed to suitably pattern the laser beam. The mask divides an incident laser beam into a number of beamlets that are incident on a corresponding number of target areas in a surface region of the semiconductor thin film. Each of the beamlets has sufficient fluence to melt the semiconductor material in target area on which it (beamlet) is incident. The dimensions of the beamlets may be chosen with consideration to the desired size of the target areas and the amount of semiconductor material that can be effectively recrystallized. Typical beamlet dimensions and corresponding target area dimensions may be of the order of the order of about 0.5 μm to a few μm.
[0010] An exemplary mask for patterning the laser beam radiation has a number of rectangular slits that are parallel to each other. Using this mask, an incident laser beam can be divided into a number of parallel beamlets. The target areas corresponding to these beamlets are distributed in the surface region in a similar parallel pattern. Another exemplary mask has a number of rectangular slits that are disposed in a rectangular pattern of sets of parallel and orthogonal slits. The slits may for example, be arranged in pairs along the sides of squares. Using this mask the resultant radiation beamlets and the corresponding target areas also are distributed in a similar rectangular pattern (e.g., in sets of parallel and orthogonal target areas).
[0011] The laser beam may be scanned or stepped across the surface of the semiconductor thin film to successively treat all regions of the surface with a repeating pattern of target areas. Conversely, the semiconductor thin film can be moved relative to a laser beam of fixed orientation for the same purpose. In one embodiment of the invention, a motorized linear translation stage is used to move the semiconductor thin film relative to the laser beam in linear X-Y paths so that all surface regions of the semiconductor thin film can be exposed to the laser beam irradiation. The movement of the stage during the process can be continuous across a width of the semiconductor thin film or can be stepped from one region to the next. For some device applications, the target areas in one region may be contiguous to target areas in the next region so that extended strips of semiconductor material can be recrystallized. The recrystallization contiguous target areas may benefit from sequential lateral solidification of the molten target areas. For other device applications, the target areas may be geometrically separate from target areas in the adjoining areas.
[0012] The generation of laser beam pulses for irradiation of the target areas may be synchronized with the movement of the linear translation stage so that the laser beam can be incident on designated target areas with geometric precision. The timing of the generated laser beam pulses may be indexed to the position of the translation stage, which supports the semiconductor thin film. The indexing may be occur in response to position sensors that indicate in real time the position of the stage, or may be based on computed co-ordinates of a geometrical grid overlaying the thin film semiconductor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Further features of the invention, its nature, and various advantages will be more apparent from the following detailed description of the preferred embodiments and the accompanying drawings, wherein like reference characters represent like elements throughout, and in which:
[0014] FIG. 1 is a schematic and block diagram of a semiconductor processing system for the laser annealing of semiconductor thin films for recrystallization;
[0015] FIG. 2 is a top exploded view of an exemplary thin film workpiece;
[0016] FIGS. 3 a and 3 b are top views of exemplary masks in accordance with the principles of present invention;
[0017] FIG. 4 is a schematic diagram illustrating a portion of the thin film silicon workpiece of FIG. 2 that has been processed using the mask of FIG. 3 a , in accordance with the principles present invention;
[0018] FIG. 5 is a schematic diagram illustrating an exemplary processed thin film silicon workpiece that has been processed using the mask of FIG. 3 b in accordance with the principles present invention; and
[0019] FIG. 6 is a schematic diagram illustrating an exemplary geometrical pattern whose co-ordinates are used to trigger radiation pulses incident on a silicon thin film workpiece in accordance with the principles present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The present invention provides processes and systems for recrystallization of semiconductor thin films by laser annealing. The processes for recrystallization of semiconductor thin films involve one-shot irradiation of regions of a semiconductor thin film workpiece to a laser beam. The systems direct a laser beam to a region or spot on the surface of the semiconductor thin film. The incident laser beam has sufficient intensity or fluence to melt targeted portions of the region or spot of the semiconductor thin film on which the laser beam is incident. After the targeted incident areas or portions are melted, the laser beam is moved or stepped to another region or spot on the semiconductor thin film. The molten semiconductor material recrystallizes when the incident laser beam is moved away. The dwell time of the laser beam on a spot on the semiconductor thin film may be sufficient small so that the recrystallization of an entire semiconductor thin film workpiece can be carried out quickly with high throughput rates.
[0021] In order that the invention herein described can be fully understood the subsequent description is set forth in the context of laser annealing of silicon thin films. The annealed silicon thin films may be intended fur exemplary TFT device applications. It will, however, be understood that the invention is equally applicable to other types of materials and/or other types of device applications.
[0022] An embodiment of the present invention is described herein with reference to FIGS. 1-6 . Thin film silicon workpieces (see e.g., workpiece 170 , FIGS. 2 and 4 - 6 ) are used herein as illustrative workpieces. Workpiece 170 may, for example, be a film of amorphous or randomly expanding and collimating lenses 141 and 142 , homogenizer 144 , condenser lens 145 , a field lens 148 , eye piece 161 , controllable shutter 152 , multi-element objective lens 163 ), also may, for example, be any suitable commercially available optical components sold by the by Lambda. Physik USA, or by other vendors.
[0023] The suitable optical components 120 - 163 for shaping and directing the radiation beam may include a masking system 150 . Masking system 150 may be a projection masking system, which is used for patterning incident radiation ( 149 ) so that radiation beam ( 164 ) that is ultimately incident on workpiece 170 is geometrically shaped or patterned.
[0024] Stage assembly 180 , on which workpiece 170 rests during processing, may be any suitable motorized translation stage capable of movement in one or more dimensions. A translation stage capable of high translation speeds may be advantageous for the high throughput single-shot processing described herein. Stage assembly 80 may be supported on suitable support structures to isolate the thin film silicon workpiece 170 from vibrations. The support structures may, for example, include conventional optical benches such as a granite block optical bench 190 mounted on a vibration isolation and self-leveling system 191 , 192 , 193 and 194 .
[0025] A computer 100 may be linked to laser 110 , modulator 120 , stage assembly 180 and other controllable components of apparatus 1000 . Computer 100 may be used to control the timing and fluence of the incident laser beam pulses and the relative movement of the stage assembly 180 . Computer 100 may be programmed to controllably move stage assembly translation stage 180 in X, Y and Z directions. Workpiece 170 may be moved, for example, over predetermined distances in the X-Y plane and as well as in the Z direction in response to instruction from computer 1000 . In operation, the position of workpiece 170 relative to the incident radiation beam 164 may be continuously adjusted or intermittently reset during the single-shot laser annealing process at suitable times according to preprogrammed process recipes for single shot recrystallization of workpiece 170 . The movement of workpiece 170 may be synchronized or co-ordinated with the timing of radiation beam pulses generated by laser 100 .
[0026] In apparatus 1000 , the movement of stage assembly 180 translates the workpiece 170 and the radiation beam ( 164 ) relative to each other. In the processing described herein the radiation beam ( 164 ) is held fixed in a position or orientation while stage 180 is moved. Alternative configurations or arrangements of optical components may be used to move incident radiation beam 164 and workpiece 170 relative to each other along defined paths. For example, a computer-controlled beam steering mirror may be used to deflect radiation beam 164 while stage 180 is held fixed in position. By such beam deflecting arrangements it may be possible to completely or partially dispense with the use of mechanical projection masks (e.g., masking system 150 ) and instead use electronic or optical beam guiding mechanisms to scan or step selected portions of workpiece 170 at a rapid pace.
[0027] Using apparatus 1000 , sequential lateral solidification of molten semiconductor material may be achieved using, for example, the processes that involve incremental movement or shifting the position of stage 180 between excimer laser pulses as described in the '531 patent. The movements of stage 170 are small, so that the portions of the silicon thin film that are molten by sequential pulses are proximate to each other. The proximity of the two molten portions allows the first portion to recrystallize and propagate its crystal structure into the adjacent portion, which is melted by the next puke.
[0028] In the single shot recrystallization processes described here, apparatus 1000 may be used to scan or step a laser beam across the surface of a semiconductor thin film by moving of stage assembly 180 . The laser beam has sufficient intensity or fluence to melt target areas in the regions or spots at which the laser beam pulses are incident. To process an entire workpiece 170 , stage assembly 180 may be moved predetermined distances to cause the laser beam to move along paths across semiconductor thin film 175 /workpiece 170 . FIG. 2 also schematically shows paths 230 , 255 etc. that may be traced by incident radiation beam 164 as it is moved across the surface of the workpiece 170 .
[0029] The number of paths and their geometrical orientation may be determined by the cross sectional dimensions of the laser beam and the target area requirements of the circuit or device applications for which workpiece 170 is being processed. Accordingly, the surface of a semiconductor thin film 175 /workpiece 170 may be partitioned in a geometric array of regions for generating processing recipes for computer 1000 or otherwise controlling the operation of apparatus 1000 . FIG. 2 shows an exemplary geometrical partitioning of the surface of a semiconductor thin film 175 on workpiece 170 . In the exemplary geometrical partitioning shown in FIG. 2 , the surface is divided into a number of rows (e.g., 205 , 206 , 207 , etc.) each having a width W. The widths of rows W may be selected with consideration to the cross sectional width of incident radiation beam 164 . Each row contains one or more regions. As an illustrative numerical example, workpiece 170 may have x and y dimensions of about 30 cms and 40 cms, respectively. Each of rows 205 , 206 , 207 , . . . etc., may, for example, have a width W of about Vi cm in the Y direction. This value of W may, for example, correspond a laser beam width of about the same size. Thus, the surface of workpiece 170 can be divided into eighty (80) rows each with a length of about 30 cms in the X direction. Each row contains one or more regions whose combined length equals 30 cms (not shown).
[0030] The co-ordinates of each row may be stored in computer 100 for use by the processing recipes. Computer 1000 may use the stored co-ordinates, for example, to compute the direction, timing and travel distances of stage 180 during the processing. The co-ordinates also may be used, for example, to time the firing of laser 110 so that designated regions of semiconductor thin film 175 are irradiated as stage 180 is moved.
[0031] Workpiece 170 may be translated in linear directions while silicon thin film 175 is being irradiated so that a linear strip of silicon thin film 175 is exposed to radiation beams of melting intensity or fluence. The translation paths traced by the radiation beams may be configured an that the desired portions of the entire surface of thin film silicon 175 are successively treated by exposure to laser beams. The translation paths may be configured, for example, so that the laser beam traverses rows 205 . 206 , 207 , etc. sequentially. In FIG. 2 , the radiation beam is initially directed to a point 220 off side 210 ′ near the left end of row 205 . Path 230 represents, for example, the translation path traced by the center of the radiation beam through row 205 as stage 180 is moved in the negative X direction.
[0032] The movement of stage 180 may be conducted in a series of steps in an intermittent stop-and-go fashion, or continuously without pause until the center of the radiation beam is directed to a point 240 near the right end of row 205 . Path segments 225 and 235 represent extensions of path 230 that may extend beyond edges 210 ′ and 210 ″ of workpiece 170 to points 220 and 240 , respectively. These segments may be necessary to accommodate acceleration and deceleration of stage assembly 180 at the ends of path 230 and/or may be useful for reinitializing stage 180 position for moving stage 180 in another direction. Stage 180 may, for example, be moved in the negative Y direction from point 240 , so that the center of the radiation beam traces path 245 to point 247 next to the right end of row 206 in preparation for treating the silicon material in row 206 . From point 247 in manner similar to the movement along path 230 in row 205 (but in the opposite direction), stage 180 is moved in the X direction so that the center of the radiation beam moves along path 255 irradiating thin film silicon material in row 206 . The movement may be continued till the center of radiation beam is incident at spot 265 that is near the left end of row 206 . Path extensions 260 and 250 represent segments of path 255 that may extend beyond edges 210 ′ and 210 ″ to spots 247 and 265 , respectively. Further linear movement of stage 180 in the Y direction moves the center of the incident radiation beam along path 270 to a point 272 next to row 207 . Then, the thin film silicon material in row 207 may be processed by moving stage 180 in the negative X direction along path 275 and further toward the opposite side 210 ″of workpiece 170 . By continuing X and Y direction movements of stage 180 in the manner described for rows 205 , 206 , and 207 , all of the rows on the surface of thin film silicon 175 may be treated or irradiated. It will be understood that the particular directions or sequence of paths described above are used only for purposes of illustration, other directions or sequences may be used as appropriate.
[0033] In an operation of apparatus 1000 , silicon thin film 175 may be irradiated by beam pulse 164 whose geometrical profile is defined by masking system 150 . Masking system 150 may include suitable projection masks for this purpose. Masking system 150 may cause a single incident radiation beam (e.g., beam 149 ) incident on it to dissemble into a plurality of beamlets in a geometrical pattern. The beamlets irradiate a corresponding geometrical pattern of target areas in a region on the thin film silicon workpiece. The intensity of each of the beamlets may be chosen to be sufficient to induce complete melting of irradiated thin film silicon portions throughout their (film) thickness.
[0034] The projection masks may be made of suitable materials that block passage of radiation through undesired cross sectional areas of beam 149 but allow passage through desired areas. An exemplary projection mask may have a blocking/unblocking pattern of rectangular stripes or other suitable geometrical shapes which may be arranged in random or in geometrical patterns. The stripes may, for example, be placed in a parallel pattern as shown in FIG. 3 a , or in a mixed parallel and orthogonal pattern as shown in FIG. 3 b , or any other suitable pattern.
[0035] With reference to FIG. 3 a , exemplary mask 300 A includes beam-blocking portions 310 which has a number of open or transparent slits 301 , 302 , 303 , etc. Beam-blocking portions 310 prevent passage of incident portions of incident beam 149 through mask 300 A. In contrast, open or transparent slits 301 , 302 , 303 , etc. permit passage of incident portions of radiation beam 149 through mask 300 . Accordingly, radiation beam 164 exiting mask 300 A has a cross section with a geometrical pattern corresponding to the parallel pattern of the plurality of open or transparent slits 301 , 302 , 303 , etc. Thus when positioned in masking system 150 , mask 300 A may be used to pattern radiation beam 164 that is incident on semiconductor thin film 175 as a collection of parallel rectangular-shaped beamlets. The beamlets irradiate a corresponding pattern of rectangular target areas in a region on the surface of the on semiconductor thin film 175 . The beamlet dimensions may be selected with a view to promote recrystallization or lateral solidification of thin film silicon areas melted by a beamlet. For example, a side length of a beamlet may be chosen so that corresponding target areas in adjoining regions are contiguous. The size of the beamlets and the inter beamlet separation distances may be selected by suitable choke of the size and separation of transparent slits 301 , 302 , 303 , etc. Open or transparent slits 301 , 302 , 303 , etc. having linear dimensions of the order of a micron or larger may, for example, generate laser radiation beamlets having dimensions that are suitable fir recrystallization processing of silicon thin films in many instances.
[0036] FIG. 3 b shows another exemplary mask 300 B with a pattern which is different than that of mask 300 A. In mask 300 B, a number of open or transparent slits 351 , 352 , 361 , 362 . etc. may, for example, be arranged in pairs along the sides of squares. This mask 300 B also may be used in masking system 150 to pattern the radiation beam 164 that is incident on semiconductor thin film 175 . The radiation beam 164 may be patterned, for example, as a collection of beamlets arranged in square-shaped patterns. The beamlet dimensions may be selected with a view to promote recrystallization or lateral solidification of thin film silicon areas melted by a beamlet. Open or transparent slits 351 , 352 , 361 , 362 , etc. having linear dimensions of about 0.5 micron may generate laser radiation beamlets of suitable dimensions for recrystallization of thin film silicon areas
[0037] It will be understood that the specific mask patterns shown in FIGS. 3 a and 3 b are exemplary. Any other suitable mask patterns may be used including, for example, the chevron shaped patterns described in the '625 patent. A particular mask pattern may be chosen in consideration of the desired placement of TFTs or other circuit or device elements in the semiconductor product for which the recrystallized thin film silicon material is intended.
[0038] FIG. 4 shows, for example, portions of workpiece 170 that has been processed using mask 300 A of FIG. 3 a . (Mask 300 A may be rotated by about 90 degrees from the orientation shown in FIG. 3 a ). The portion shown corresponds to a row, for example, row 205 of workpiece 170 ( FIG. 2 ). Row 205 of processed workpiece 170 includes recrystallized polycrystalline silicon linear regions or strips 401 , 402 , etc. Each of the linear strips is a result of irradiation by a radiation beamlet formed by a corresponding mask slit 301 , 302 , etc. The continuous extent of recrystallized silicon in the linear strips across row 205 may be a consequence, for example, of a continuous movement of the stage 180 along path 230 under laser beam exposure ( FIG. 2 ). Strips 401 , 402 , may have a microstructure corresponding to the one shot exposure with colliding liquid/solid growth fronts in the center creating a long location-controlled grain boundary. Alternatively, in a directional solidification process the continuous extent may be a result of closely spaced stepped movements of stage 180 along path 230 that are sufficiently overlapping to permit formation of a continuous recrystallized silicon strip, hi this alternative process, the microstructure of the recrystallized material may have long grains parallel to the scanning direction. The recrystallized polycrystalline silicon (e.g. strips 401 , 402 , etc.) may have a generally uniform structure, which may be suitable for placement of the active region of one or more TFT devices. Similarly, FIG. 5 shows, exemplary results using mask 300 B of FIG. 3 b , Exemplary processed workpiece 170 includes recrystallized polycrystalline silicon strips 501 , 502 , etc. Recrystallized polycrystalline silicon strips 501 , 502 , etc. like strips 401 and 402 may have a uniform crystalline structure, which is suitable for placement of the active regions of TFT devices. Strips 501 and 502 that are shown to be generally at right angles to each other may correspond to radiation beamlets formed by orthogonal mask slits (e.g., FIG. 3 b slits 351 , 361 ). The distinct geometrical orientation and physical separation of strips 501 and 502 (in contrast to extended length of strips 401 and 402 ) may be a consequence, for example, of physically separated exposure to laser radiation during the processing of workpiece 170 . The separated radiation exposure may be achieved by stepped movement of stage 180 (e.g., along path 230 FIG. 2 ) during the processing. Additionally or alternatively, the separated exposure may be achieved by triggering laser 110 to generate radiation pulses at appropriate times and positions of stage 180 along path 230 while stage 180 and laser beam 164 are moved or scanned relative to each other at constant speeds.
[0039] Computer 100 may be used control the triggering of laser 110 at appropriate times and positions during the movement of stage 180 . Computer 100 may act according to preprogrammed processing recipes that, for example, include geometrical design information for a workpiece-in-process. FIG. 6 shows an exemplary design pattern 600 that may be used by computer 1000 to trigger laser 110 at appropriate times. Pattern 600 may be a geometrical grid covering thin film silicon 175 /workpiece 170 . The grid may, for example, be a rectangular x-y grid having co-ordinates (x 1 , x 2 , . . . etc.) and (y 1 , y 2 , . . . etc.). The grid spacings may be regular or irregular by design. Pattern 600 may be laid out as physical fiducial marks (e.g., on the thin film workpiece) or may be a mathematical construct in the processing recipes. Computer 100 may trigger laser 110 when stage 180 is at the grid coordinates (xi, yi). Computer 100 may do so in response, for example, to conventional position sensors or indicators, which may be deployed to sense the position of stage 180 . Alternatively, computer 100 may trigger laser 110 at computed times, which are computed from parameters such as an initial stage position, and the speeds and direction of stage movements from the initial stage position. Computer 100 also may be used advantageously to instruct laser 110 to emit radiation pulses at a variable rate, rather than at a usual even rate. The variable rate of pulse generation may be used beneficially to accommodate changes in the speed of stage 180 , for example, as it accelerates or decelerates at the ends of paths 230 and the like.
[0040] It will be understood that the foregoing is only illustrative of the principles of the invention and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention, which is limited only by the claims that follow. | High throughput systems and processes for recrystallizing thin film semiconductors that have been deposited at low temperatures on a substrate are provided. A thin film semiconductor workpiece is irradiated with a laser beam to melt and recrystallize target areas of the surface exposed to the laser beam. The laser beam is shaped into one or more pulses. The beam pulses have suitable dimensions and orientations to pattern the laser beam radiation so that the areas targeted by the beam have dimensions and orientations that are conductive to semiconductor recrystallization. The workpiece is mechanically translated along linear paths relative to the laser beam to process the entire surface of the workpiece at high speeds. Position sensitive triggering of a laser can be used to generate laser beam pulses to melt and recrystallize semiconductor material at precise locations on the surface of the workpiece while it is translated on a motorized stage. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of provisional patent applications: Inflator Employing A Propellant Produced From A Tetrazine-Based Energetic Material, Ser. No. 60/773,382 filed Feb. 13, 2006, Apparatus And Method For Employing Tetrazine-Based Energetic Material As A Propellant, Ser. No. 60/885,987 filed Nov. 11, 2006 and Apparatus And Method For Employing Tetrazine-Based Energetic Material To Produce A Fire Suppressant Gas, Ser. No. 60/859,058 filed Nov. 15, 2006, the disclosures of each of which are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to an apparatus and method for using tetrazine-based energetic materials. More particularly, this invention relates to an apparatus or method employing a gas produced from a tetrazine-based energetic material. This invention further relates to igniting the tetrazine-based energetic material. In some embodiments, the tetrazine-based energetic material is ignited through the use of a percussion cap, a piezoelectric crystal or a battery-supplied electric spark or by encapsulating it in a container that is then exposed to a burning flame. This invention further relates to using the gas produced upon ignition as a propellant such as to inflate life rafts, life vests, emergency evacuation slides, tires, air bags other inflatable devices. Still further, this invention relates to using the gas produced upon ignition in many other applications such as a fire suppressant or as an alternative vehicle fuel.
[0004] 2. Description of the Related Art
[0005] Presently, tetrazine-based energetic materials are well-known, such as that known as “BTATz” containing 3;6-BIS(1H-1,2,3,4-Tetrazol-5-ylamino)-1,2,4,5-tetrazine or salts thereof, as disclosed in U.S. Pat. Nos. 6,458,227 and 6,657,059, the disclosures of each of which are hereby incorporated by reference herein. BTATz was developed by the Los Alamos Laboratory principally as an explosive for military applications. The gas produced by igniting BTATz has many beneficial properties that have been incorporated by the present invention in many commercial applications such using the gas as a propellant to inflate life rafts, life vests, emergency evacuation slides, tires, air bags and other inflatable devices or as an alternative vehicle fuel to power an engine and such as using the gas as a fire suppressant.
[0006] More specifically, by way of background in the inflation art, there exist many types of inflators designed to inflate inflatable articles such as personal floatation devices (life vests, rings and horseshoes), life rafts, buoys, emergency signaling equipment and emergency evacuation slides. Inflators typically comprise a body for receiving the neck of a gas cartridge of compressed gas such as carbon dioxide. A reciprocating piercing pin is disposed within the body of the inflator for piercing the frangible seal of the gas cartridge whereupon the compressed gas therein flows into an exhaust manifold of the inflator and then into the article to be inflated. Typically, a manually movable firing lever is operatively connected to the piercing pin such that the piercing pin pierces the frangible seal of the cartridge upon jerking of a ball lanyard. U.S. Pat. No. 3,809,288, the disclosure of which is hereby incorporated by reference herein, illustrates one particular embodiment of a manual inflator.
[0007] In the inflation art, the gas cartridge is usually sized to contain the volume of carbon dioxide necessary to inflate the article. Small inflatable articles such as life vests are inflated with a relatively small volume of carbon dioxide. Hence, smaller gas cartridges can easily be employed. Larger articles such as life rafts and emergency evacuation slides for aircraft, require significantly larger volumes of carbon dioxide. Hence, either larger gas cartridges, or a multiplicity of gas cartridges, or a combination of both, must be used in order to have a sufficient volume of carbon dioxide to fully inflate the article.
[0008] It is desirable in many applications in the inflation art to minimize the weight of the inflatable article. For example, in the aircraft industry, it is desirable to minimize the weight of every appliance in the aircraft including the gas cartridges used to inflate the life vests, life rafts and emergency escape slides. Likewise, in other applications it is often desired to minimize not only the weight but also the size of the gas cartridge employed in the inflatable equipment. Hence, there presently exists a need for lighter weight and smaller sources for inflation gas which produce the same or higher volume of a propellant than conventional carbon dioxide gas cartridges. In related inflation applications such as air bags and the like, there likewise exists a need for producing an environmentally safe gas to inflate the air bag. For example, with regard to air bags, it is noted that various prior art propellants have been used in automotive safety restraint air bags. Most of these prior art propellants are problematic due to excessive heat generated, high sensitivity to inadvertent ignition. Some may even be are toxic in their unburned or burned state. Current prior art air bag propellants often pose a risk to the environment and require special handling and disposal procedures. Additionally, many of the prior art pyrotechnic materials commonly used in automotive air bags pose a risk of being collected and reused as improvised explosive devices.
[0009] Related to minimizing harmful propellants used in air bags, in the fire suppressant art, there also presently exists a need for producing an fire-suppressing gas that is safe to humans. Likewise, there presently exists a need for an environment-friendly gas that can be employed as an alternative vehicle fuel to power an engine, thereby minimizing fossil fuel pollution and greenhouse gases.
[0010] Therefore, it is an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art and provides an improvement which is a significant contribution to the advancement of using BTATz in a large variety of applications.
SUMMARY OF THE INVENTION
[0011] For the purposes of summarizing the invention, the present invention comprises apparatuses and methods employing a gas produced from a tetrazine-based energetic material such as that known as “BTATz” containing 3;6-BIS(1H-1,2,3,4-Tetrazol-5-ylamino)-1,2,4,5-tetrazine or salts thereof, as disclosed in U.S. Pat. Nos. 6,458,227 and 6,657,059, the disclosures of each of which are hereby incorporated by reference herein. In some embodiments, the tetrazine-based energetic material is ignited according to the present invention through the use of a percussion cap, a piezoelectric crystal or a battery-supplied electric spark or by encapsulating it in a container that is then exposed to a burning flame. The gas produced upon ignition is employed a propellant such as to inflate life rafts, life vests, emergency evacuation slides, tires, air bags and other inflatable devices. The gas produced upon ignition is alternatively employed to power an engine. Alternatively, according to the present invention, the gas produced upon ignition is employed in many other applications such as a fire suppressant.
[0012] More specifically, BTATz is employed as a deflagrating gas generating propellant to provide principally nitrogen gas as the inflation gas medium. The BTATz material is chosen, in part, due to the non-toxic nature of the effluent gasses produced from the deflagration of the material and its non-explosive nature as an energetic material. The effluent gas temperatures of BTATz remain sufficiently low and have a very rapid cooling rate to allow use of the propellant in traditional life vest, life raft and other emergency inflatable device gas containment bladder devices without thermal damage to the device or contact or exposure harm to the user.
[0013] The charge or grain shape of the BTATz material as employed in various embodiments of inflator may be of a variety of forms or shapes as specifically required with regard to time pressure curves desired for the inflation event. The grain shape may be alternately formed as a loose powder, a pelletized shape, a monolithic single grain charge or any number of specific geomemes required to provide the desired deflagration rate and gas generation, as well as any number of desired packaging arrangements suited to various inflators for various purposes, including, but not limited to; life vests, life rafts, aircraft emergency escape slides. Additionally, a variety of other chemicals may be added to the BTATz material to alter the performance with regard to deflagration rate, gas effluent temperature or other properties as required for specific environments or applications for the inflator device. The BTATz material may employ a binder material in order to form specific grain shapes as previously mentioned. Binder materials may include PVA, (polyvinylalcohol), PEA, (polyethylacrylate), or other appropriate chemical materials to provide a binding property to the base material in order to maintain a specific structure or formation such as pellets, spherical balls or a monolithic grain shape. Addition of a binder material to the BTATz has demonstrated a notable reduction in the electrostatic discharge spark sensitivity of the material. In order to reliably initiate deflagration of BTATz with binder material, inclusion of “neat” material (without binder), may be utilized as a primary, spark sensitive, charge to facilitate ignition when employing an electrical spark as ignition means.
[0014] In the several embodiments of the invention, the inflator may be initiated by either manual or automatic means or by a combination of manual and automatic methods. Initiation or ignition of the BTATz charge in the inflator mechanism may be by means of, but not limited to, a pyrotechnic primary charge such as a commercial primary or percussion cap, electrical or mechanical pyrotechnic squib, electric match, spark generated by a stored electrical energy source such as a battery or generated by means of a Piezoelectric device. In an automatic initiation mode the inflator device may be triggered by either mechanical or electronic means. Mechanical initiation may comprise a pull type lanyard and lever arrangement that alternately either releases a mechanical hammer or firing pin to strike a primary percussion cap or activates a Piezoelectric generator to produce electric spark across a conductive gap to initiate the BTATz propellant.
[0015] Optional automatic initiation may be by means of a water immersion sensing electronic circuit that will trigger release of battery stored electric energy to produce a spark, activate a pyrotechnic squib, initiate an electric match, or trigger the release of a mechanical hammer or firing pin to impact a primary or percussion pyrotechnic cap. Alternately, automatic initiation may be by means of a water-soluble bobbin that upon dissolving, releases a hammer or firing pin arrangement to strike a percussion or primary cap.
[0016] One embodiment of the inflator device includes an actuating lever and cam arrangement that provides for multiple striking impacts of the hammer or firing pin mechanism against the primary or percussion cap upon a single pull of the lever. Another embodiment of the inflator mechanism includes a similar lever and cam arrangement that provides for multiple actuations of a piezoelectric spark generator. Both multiple actuation mechanisms serve to provide a safety factor to insure activation of the BTATz deflagration event.
[0017] Containment of the BTATz gas generating charge may be in a separate metal, thermoplastic, thermosetting plastic or elastomeric container that is readily attachable and detachable from the inflator mechanism body to facilitate ease of arming and rearming the device. One embodiment of the charge container employs both the gas generating BTATz material and a percussion or primary cap. Another embodiment of the charge container includes electrical contact points and an internal conductive spark gap arrangement. Charge containers may have hermetic sealing to preclude moisture entry into the chemical charge and ignition components.
[0018] Charge containers may be of varying sizes and geometric configurations to contain various quantities of BTATz material, various grain geometries or various specialized connections for different specific inflator devices.
[0019] Another embodiment of the inflator includes a means of indicating alternately a fired or unfired, (ready), state by displaying an appropriate color indicator or by means of a physical indicator.
[0020] The inflator may be fabricated from thermoplastic, thermosetting polymer, metal, elastomeric material or any combination thereof.
[0021] The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
[0023] FIG. 1 is an exploded view of a gas cartridge containing the BTATZ material fluidly connected to an inflatable article to inflate the article upon activation of the BTATZ material;
[0024] FIG. 2 is a cut-away view of a device using BTATz as a propellant for automotive safety restraint air bags;
[0025] FIG. 3 is a cut-away view of a device containing BTATz that may be thrown, propelled, dropped or otherwise introduced into a fire to suppress the same;
[0026] FIG. 4 is a cut-away view of a portable fire extinguisher containing BTATz;
[0027] FIG. 5 is a cut-away view of a solid-material fire extinguisher containing BTATz without other propellants;
[0028] FIG. 6 is a cross-sectional view of a BTATz inflator including an electronic, water sensing trigger that ignites the BTATz material upon being submerged in a body of water;
[0029] FIG. 7 illustrates a BTATz tire inflator including an adjustable pop-off valve that limits the amount of gas pressure during inflation of the tire;
[0030] FIG. 8 illustrates a BTATz inflator that may be heat-sealed to a life vest or other inflatable; and
[0031] FIG. 9 illustrates a BTATz alternative fuel engine in which quantities of BTATz material are sequentially ignited to produce supplies of nitrogen gas to drive the engine.
[0032] Similar reference numerals refer to similar parts throughout the several figures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] The present invention comprises an apparatus and method for employing a gas produced from a tetrazine-based energetic material such as that known as “BTATz” as a propellant in one or more of the devices disclosed in the patents and patent applications listed in Table I appended hereto, the disclosures of each of the patents and patent applications are hereby incorporated by reference herein. More particularly, the BTATz propellant may be employed in any device, system or application, such as those described in Table I, in which a source of harmless gas is needed to be generated from a supply of material.
[0034] Without limiting the scope of the preceding paragraph, referring to FIG. 1 , one embodiment of the invention comprises a gas cartridge 1 - 10 having an outlet 1 - 12 for fluid connection to an inflatable article, shown generally as reference numeral 1 - 14 . The gas cartridge 1 - 10 comprises a conical reaction chamber 1 - 16 that contains the BTATZ material 1 - 18 . The conical reaction chamber 1 - 16 is desired to control the gas evolution rate as the BTATZ material 1 - 18 burns linearly (which is believed to be achievable through use of a binder). The conical chamber 1 - 16 is hermetically sealed and screen-off by a cover 1 - 20 to prevent moisture egress and hold the BTATZ material 1 - 18 in place in the chamber 1 - 16 . The conical chamber 1 - 16 is mounted within a cylindrical housing 1 - 22 which provides mechanical stability and creates an air gap that affords a low thermal conductivity, and thus a high resistance to heat transfer. A hemispherical dome 1 - 24 is positioned over the cover 1 - 20 to provide a headspace volume for the nitrogen gas to pressurize to drive Joule-Thompson cooling through the outlet 1 - 12 . Respective crimping flanges 1 - 26 allows the aforementioned parts to be crimped into a single unit that will withstand the pressure of the entire gas discharge from the deflagration of the BTATZ material 1 - 18 .
[0035] Another embodiment of the invention comprises using BTATz as a propellant for automotive safety restraint air bags. BTATz is particularly suited to be employed as a propellant for air bags due to its high nitrogen gas output and low gas temperatures. Also, the BTATz material is nontoxic and environmentally safe and is non-detonable, rendering it unusable for nefarious purposes, such as improvised explosive devices. The high nitrogen gas output of BTATz allows less propellant to accomplish inflation of the air bag restraint than with current commonly used materials.
[0036] More particularly, referring to FIG. 2 , the air bag inflation device of the invention comprises a vented housing 2 - 10 in which is positioned an internal cavity 2 - 12 filled with the BTATz propellant 2 - 14 . A firing cap/squib/igniter 2 - 16 is positioned within the bottom of the cavity 2 - 12 with its firing leads 2 - 16 L extending through the housing 2 - 10 for connection to a firing mechanism. A space may be provided between the vents 2 - 18 of the housing 2 - 10 and the internal cavity 2 - 12 to receive a filter 2 - 20 therein. The filter 2 - 20 functions to filter the gas produced by the propellant 2 - 14 upon firing.
[0037] Upon sensing an impact, the air bag firing mechanism is actuated to produce an electrical signal to fire the firing cap 2 - 16 , whereupon the BTATz propellant 2 - 14 ignites to produce the nitrogen gas that is then filtered to exit the housing 2 - 10 and inflate the airbag.
[0038] Another embodiment of the invention comprise an apparatus and method for employing a gas produced from a tetrazine-based energetic material such as that known as “BTATz” as a fire suppressant in one or more of the devices disclosed in the patents and patent applications listed in Table II appended hereto, the disclosures of each of the patents and patent applications are hereby incorporated by reference herein. More particularly, the BTATz propellant may be employed in any device, system or application, such as those described in Table I, in which a source of harmless gas is needed to be generated from a supply of material. More particularly, the fire suppressant nitrogen gas produced upon ignition of the BTATz material may be employed in any device, system or application, such as those described above, in which a source of fire suppressant gas is needed to be generated from a supply of material.
[0039] As shown in FIG. 3 , in accordance with the spirit and scope of the invention and without limitation, one exemplary application includes filling a container 3 - 10 with the BTATz material 3 - 12 to be fully encapsulated therein. The container 3 - 10 is constructed of a material 3 - 14 such that when it is thrown, propelled, dropped or otherwise introduced into a fire, the material 3 - 14 constituting the container 3 - 10 is melted, burned, cracked-open or otherwise released to expose the BTATz material 3 - 12 to the fire, whereupon the BTATz material 3 - 12 is then ignited by the flames of the fire. Upon ignition of the BTATz material 3 - 12 , a large volume of fire-suppressing nitrogen gas is produced to starve the fire of oxygen and thereby extinguish the fire. It is contemplated that the container 3 - 10 may comprise a variety of configurations and sizes for ease in being introduced into the fire.
[0040] More particularly, without limiting the spirit and scope of the invention, the container 3 - 10 may comprise a softball-sized flammable container 3 - 10 filled with the BTATz material 3 - 12 that is easily grasped by the human hand to be thrown into a burning fire. Once the soft-ball sized container 3 - 10 is in the fire, the flammable material 3 - 14 constituting the container 3 - 10 catches on fire whereupon the BTATz fire suppressant material 3 - 12 is ignited to produce a large volume of fire-suppressing nitrogen gas to extinguish the fire. Depending on whether the fire is burning in an enclosed space or is burning in the open, many of the soft-ball sized containers 3 - 10 may be thrown in as necessary to put out the fire. In the case of a forest fire, many, even thousands, of the soft-ball sized (or larger) containers 3 - 10 can be air-dropped into the fire.
[0041] As shown in FIG. 4 , BTATz material 4 - 12 may be incorporated into portable fire extinguishers 4 - 16 with or without other propellants. For example, as shown in FIG. 4 , similar to a conventional fire extinguisher 4 - 16 employing a propellant, a gas cylinder 4 - 18 may be partially filled via its opening 4 - 20 with the BTATz material 4 - 12 . A conventional hand-operated dispensing valve/nozzle 4 - 22 is then installed in the opening and the cylinder 4 - 18 is pressurized with a gas 4 - 24 . When needed to put out a fire, the nozzle 4 - 22 is pointed to the base of the fire and the valve 4 - 20 is actuated whereupon the pressurized gas 4 - 24 forces the BTATz material 4 - 12 from the bottom of the cylinder 4 - 18 up through a central tube 4 - 26 to then be propelled toward the base of the fire where it is ignited to produce a large volume of nitrogen gas that deprives the fire of oxygen thereby extinguishing the fire.
[0042] It is noted that the above-described “portable” extinguishers 4 - 16 may comprise a valve 4 - 22 that is actuated when a fire is sensed such that the extinguisher 4 - 16 may be mounted in a fixed location, such as in the bilge of a boat, to automatically release BTATz material 4 - 12 once a fire is detected.
[0043] The BTATz material may employed within a fire extinguisher 4 - 16 without a propellant. More particularly, a shown in FIG. 5 , the valve 5 - 22 may include an igniter (e.g., squib, percussion cap or other electronic or mechanical spark-generator). With the cylinder 5 - 18 being filled with the BTATz material 5 - 12 , it may be directly ignited by the igniter of the valve 5 - 22 . Upon ignition within the cylinder 5 - 18 , the expanding nitrogen gas produced from the burning BTATz material 5 - 12 pressurizes the cylinder 5 - 18 . The pressurized cylinder 5 - 18 is thus “charged” and the nitrogen gas therein may then be immediately released (or released at will) to extinguish the fire (similar to gas fire suppression systems that store Halon, FM2000 or other fire-suppression gases). Indeed, igniter of the valve 5 - 22 may be remotely actuated via a sensor 5 - 30 in an area 5 - 32 to be protected (e.g., computer room). The container 5 - 12 may be fixedly mounted on one central location and its output 5 - 34 plumbed to the protected area 5 - 32 in which the sensor is located 5 - 30 . In this manner, when a fire is detected in the protected area 5 - 32 , the igniter of the valve 5 - 22 is actuated ignite the BTATz material 5 - 12 to produce a large volume of nitrogen gas which then flows through the piping 34 to be injected into the protected area 5 - 32 to extinguish the fire.
[0044] Thus, it should be appreciated that the BTATz fire suppressant material 5 - 12 , coupled with an ignition system, may be used as a substitute for Halon or FM2000 in a large variety of fire suppression systems, such as those described in the above-listed patents and patent applications.
[0045] Referring to FIG. 6 , in another embodiment of a BTATz inflator of the invention, a generally cylindrical BTATz charge container 6 - 10 is partially filled with an amount of BTATz material 6 - 12 and then the charge container 6 - 10 is filled with a primer charge 6 - 14 . Preferably, a hollow central core 6 - 16 extends through the BTATz gas-generating charge 6 - 12 and the primer charge 6 - 14 of a specific grain shape that defines the burn rate of the BTATz material 6 - 12 once ignited by the primer charge 6 - 14 . The charge container 6 - 10 is then sealed with a hermetic seal membrane 6 - 16 (e.g., a film). A particulate filter 6 - 18 is installed over the seal membrane 6 - 16 and then a vented cover 6 - 20 with a downward-extending igniter 6 - 22 is installed about the opened end of the charge container 6 - 10 with the igniter 6 - 22 extending into the hollow central core 6 - 16 of the primer charge 6 - 14 . The exposed surface of the vented cover 6 - 20 includes swash-plate electrical contacts 6 - 24 electrically connected to the igniter 6 - 22 to fire the same upon application of an electrical voltage to the contacts 6 - 24 . Upon firing of the igniter 6 - 22 , the primer charge 6 - 14 is ignited which in turn ignites the main BTATz gas generating charge 6 - 12 to produce a supply of nitrogen gas at a rate determined by the grain shape employed. The nitrogen gas produced is vented from the charge container 6 - 10 via the vents in the cover 6 - 20 .
[0046] The BTATz charge container 6 - 10 is dimensioned to be replaceably installed, preferably sealably, within a lower chamber of a generally cylindrical inflator housing 6 - 26 and held into position once installed by locking lugs 6 - 28 that lock into corresponding locking grooves 6 - 30 formed in the lumen of the inflator housing 6 - 26 . The exposed end of the charge container 6 - 10 includes a finger tab 6 - 30 to facilitate installation of a fresh charge container 6 - 10 and then removal once the charge container 6 - 10 is spent (i.e., fired).
[0047] An exhaust port 6 - 32 is located in the lower chamber of the inflator housing 6 - 26 above the vents of the cover 6 - 20 of the charge container 6 - 10 such that upon ignition of the main BTATz gas generating charge 6 - 12 to produce the supply of nitrogen gas, the gas being vented therefrom is exhausted via the exhaust port 6 - 32 into the article to be inflated.
[0048] The inflator housing 6 - 26 further includes a separate upper chamber sealed from the lower chamber by an intermediate divider wall 6 - 34 . The upper chamber contains an water-activated electronic assembly, generally indicated by numeral 6 - 36 , that functions to supply a firing voltage to the electrical contacts 6 - 24 of the igniter 6 - 22 to fire the same when the inflator housing 6 - 26 is submerged in a body of water. More specifically, the electronic assembly 6 - 36 comprises a pair of water immersion contact sensors 6 - 38 extending through a wall of the upper chamber of the housing 6 - 26 . The sensors 6 - 38 are electrically connected to a controller 6 - 40 contained within the upper chamber. The controller 640 optionally is composed of discrete electrical components, integrated circuits or a microcontroller powered by a battery source 642 also contained within the upper chamber. The controller 640 senses when the sensors 6 - 38 have been submerged in a body of water.
[0049] The controller 6 - 40 further comprises output contacts 642 that extend through the intermediate wall 6 - 34 to make electrical contact with the respective swash plate electrical contacts 6 - 24 of the igniter 6 - 22 when the charge container 6 - 10 is installed in the lower chamber of the housing 6 - 26 . When the controller 6 - 40 senses that the sensors 6 - 38 have been submerged in a body of water, it produces an output voltage to its output contacts 6 - 42 to fire the igniter 6 - 22 .
[0050] It is noted that optionally the controller 6 - 40 may further include a red/green status indicator LED 6 - 44 that extends through the wall of the upper chamber of the housing 6 - 26 to indicate the firing condition (i.e., green for ready and red indicating a spent charge container 6 - 10 , low battery or other inoperative condition) of the inflator. Further optionally, the operation of the controller 640 may be controlled by an on/off mode switch 6 - 46 extending through the wall of the upper chamber housing 6 - 26 . It is further noted that the sensors 6 - 38 , the indicator LED 6 - 44 and the mode switch 6 - 46 are preferably sealed as they extend through the wall of the upper chamber to preclude any moisture from entering the upper chamber and otherwise damaging the operation of the controller 6 - 40 . Finally, it is noted that the end of the upper chamber may be removable to allow replacement of the battery 642 .
[0051] As shown in FIG. 7 , still another embodiment of the BTATZ inflator of the invention, similar to that of FIG. 6 , but configured to function as a tire inflator 7 - 10 . More specifically, the tire inflator 7 - 10 of the invention comprises a generally cylindrical housing 7 - 12 that sealingly receives at is proximal end a replaceable BTATz charge container 7 - 14 by circumferential mating threads 7 - 16 on the outside of the charge container 7 - 14 and the lumen of the housing 7 - 12 .
[0052] The charge container 7 - 14 includes a threaded vented cap 7 - 18 allowing filling. The charge container 7 - 14 is filled with a supply of BTATz material. A spark gap 7 - 16 is formed in the upper end of the charge container 7 - 14 for creating a spark when voltage is applied to its leads 7 - 18 . The firing spark created is injected into the charge container 7 - 14 to ignite the BTATz material therein. As described above in relation to FIG. 6 , the BTATz material may include a hollow core with a desired grain shape to control the degree of burning and hence the rate at which the nitrogen gas is produced. The nitrogen gas produced upon burning of the BTATz material is vented from charge container 7 - 14 into the distal end of the housing 7 - 12 .
[0053] A piezoelectric mechanism 7 - 20 is mounted to the wall of the distal end of the housing 7 - 12 . The piezoelectric mechanism 7 - 20 comprises a push-button 7 - 22 that when pressed, creates a spark of voltage by the piezoelectric that is supplied by internal electrical leads 7 - 24 to the leads 7 - 18 of the spark gap 7 - 16 . Thus, it should be appreciated that upon depressing the push-button 7 - 22 , the piezoelectric fires to create a spark of voltage that is supplied to the spark gap 7 - 16 to ignite the BTATz material in the charge container 7 - 14 , whereupon the nitrogen gas produced therein is vented into the distal end of the housing 7 - 12 .
[0054] The distal end of the housing is 7 - 12 is preferably tapered to receive a valve 7 - 26 that is designed to open a conventional inflation valve of a standard automotive tire, commonly referred to as a Schrader Valve. Consequently, during use to fill a tire, the valve 7 - 26 may be engaged into the tire's Schrader Valve and the push-button 7 - 22 depressed to fire the BTATz charge container 7 - 14 , whereupon the nitrogen gas produced flows into the tire to inflate the same.
[0055] Preferably, in order to prevent over-inflation of the tire, a presettable pressure-limiting mechanism 7 - 28 is incorporated into the housing 7 - 12 to automatically exhaust gas pressure to the atmosphere whenever the pressure of the gas exceeds the presettable pressure. IN one embodiment, the presettable pressure-limiting mechanism comprises an adjustable pop-off relief valve 7 - 30 whose pop-off pressure is presettable by a dial 7 - 32 with a pressure indicator lines 7 - 34 formed thereon. The indicator lines 7 - 34 allows informed dialing of the desired presettable pressure (e.g., 30 psi) whereupon any excess gas pressure is automatically vented from the housing 7 - 12 , thereby assuring that the tire is inflated only to such desired pressure (e.g., 30 psi).
[0056] As shown in FIG. 8 , a further embodiment of the BTATz inflator of the invention comprises an inflator 8 - 10 that employs a percussion cap 8 - 12 to ignite a charge container 8 - 14 filled with BTATz material 8 - 14 . In the specific embodiment illustrated, an inflator housing 8 - 16 comprises a generally rectangular configuration having a peripheral flange 8 - 18 that is intended to be heat-sealed to an inflatable article such as a life vest, life raft, evacuation chute or the like. The underside of the inflator housing 8 - 16 includes an exhaust port 8 - 20 fluidly connected to interior of the inflatable article to inflate the same upon firing of the charge container 8 - 14 .
[0057] Similar to the previous embodiments disclosed above, the charge container 8 - 14 comprises a generally cylindrical design that is removably installed into the inflator housing 8 - 16 , preferably sealingly by means of an O-ring 8 - 22 . The vented end cover of the charge container 8 - 14 allows filing with a desired quantity of BTATz material which, upon ignition, produces a desired volume of nitrogen gas to inflate the inflatable article.
[0058] The vented end cover of the charge container 8 - 14 comprises a percussion cap seat 8 - 24 configured to receive a percussion cap 8 - 26 . The percussion cap 8 - 26 functions upon striking to inject a spark into the charge container 8 - 14 to ignite the BTATz material contained therein.
[0059] A firing mechanism, generally indicated by numeral 8 - 28 , is provided to strike the percussion cap 8 - 26 one or more times upon the jerking of a lanyarded pull handle 8 - 30 . More specifically, the firing mechanism 8 - 28 comprises a generally cylindrical firing hammer 8 - 32 reciprocatingly positioned within an elongated bore 8 - 34 that is forcibly urged toward the percussion cap 8 - 26 by a firing spring 8 - 34 . An O-ring 8 - 36 is fitted about the firing hammer 8 - 22 to seal with the bore 8 - 34 , thereby precluding any blow-by of the nitrogen gas upon firing.
[0060] The lanyarded pull handle 8 - 30 is coupled to a pivotal trigger lever 8 - 36 . The trigger lever 8 - 36 includes at least one lobe 8 - 38 in alignment with an integral tang 8 - 38 extending transversely from the firing hammer 8 - 32 . As the pull-handle 8 - 30 is jerked, the lobe 8 - 38 pulls back the firing hammer 8 - 32 against the force of the firing spring 8 - 34 as the trigger lever 8 - 36 is pivoted until the lobe 8 - 38 slips off of the tang 8 - 38 to release the spring-loaded firing hammer 8 - 22 . Upon releasing of the spring-loaded firing hammer 8 - 22 , the hammer 8 - 22 is forcibly urged by the spring 8 - 34 toward the percussion cap 8 - 26 to strike the same and cause it to fire, thereby producing the nitrogen gas that is then vented from the charge container 8 - 14 from the housing 8 - 16 via exhaust port 8 - 20 to inflate the inflatable article.
[0061] As illustrated, preferably the trigger lever 8 - 36 includes plural lobes 8 - 34 (e.g., three) such that upon a single jerking of the pull handle 8 - 30 , each of the lobes 8 - 34 sequentially pulls back the firing hammer 8 - 32 and then slips off the tang 8 - 38 , thereby firing the hammer 8 -
[0062] A control unit 9 - 12 receives a signal from a pressure transducer 9 - 18 when the gas pressure in the storage tank drops below a predetermined level, at which point the control unit 9 - 12 provides an electric current to the igniter 9 - 11 to fire a BTATz charge in the combustion chamber 9 - 10 . The combustion chamber may contain several BTATz charges, which can be independently fired as needed to maintain the predetermined pressure level in the storage tank 9 - 6 .
[0063] In the event of an over-pressure condition in the storage tank, an emergency pressure relief valve 9 - 4 opens and exhausts gas to the atmosphere through an exhaust tube 9 - 5 . Once the gas pressure drops to the determined safe level, the relief valve 9 - 4 closes.
[0064] The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.
[0065] Now that the invention has been described,
[0000]
TABLE I
PROPELLANT APPARATUSES AND METHODS
Publication
Number
Title
RE36,296
Propellant composition for automotive safety applications
RE30,327
Inflator seal
RE36,587
Inflatable seat belt having bag filter
RE36,661
Inflatable seat belt with leak detection device
RE33,938
Aspirating/venting air bag module assembly
3,934,984
Gas generator
3,938,826
Aspirated vehicle occupant restraint system
3,942,051
Shock actuated electrical pulse generator
3,942,819
Safety belt tensioning device
3,966,226
Fluid supply for occupant restraint system
3,971,322
Pressure actuated tube primer
4,008,830
Liquid dispenser using a non vented pump and a collapsible plastic bag
4,023,643
Deceleration-responsive passenger-restraining device for motor vehicles
4,050,483
Inflation surge delay
4,061,088
Electric detonating fuse assembly
4,179,327
Process for coating pyrotechnic materials
4,198,075
Safety installation in motor vehicles with a knee impact element
4,200,615
All-pyrotechnic inflator
4,203,786
Polyethylene binder for pyrotechnic composition
4,203,787
Pelletizable, rapid and cool burning solid nitrogen gas generant
4,238,253
Starch as fuel in gas generating compositions
4,243,248
Air bag system for the protection of the passengers of motor vehicles in case of
accidents
4,244,758
Ignition enhancer coating compositions for azide propellant
4,246,051
Pyrotechnic coating composition
4,249,632
Safety device for the protection of pedestrians
4,369,079
Solid non-azide nitrogen gas generant compositions
4,369,707
Short circuit fuse for electrical igniters
4,370,181
Pyrotechnic non-azide gas generants based on a non-hydrogen containing tetrazole
compound
4,370,930
End cap for a propellant container
4,397,596
Method of making container for gas generating propellant
4,414,902
Container for gas generating propellant
4,424,914
Air bag explosive device
4,437,681
Inflator for a protective inflatable cushion system
4,441,632
Soft shell aerosol dispenser unit
4,462,244
Apparatus for field testing a smoke detector
4,484,577
Drug delivery method and inhalation device therefor
4,533,416
Pelletizable propellant
4,580,810
Air bag system
4,600,123
Propellant augmented pressurized gas dispensing device
4,604,151
Method and compositions for generating nitrogen gas
4,664,234
Self pressurized damper
4,706,990
Mechanical impact sensor for automotive crash bag systems
4,758,287
Porous propellant grain and method of making same
4,761,254
Method of and apparatus for fabricating a tool to form an asymmetrical constant
cross section bore in the propellant in a solid rocket motor
4,766,799
Method of and apparatus for fabricating a tool to form an asymmetrical constant
cross section bore in the propellant in a solid rocket motor
4,798,142
Rapid buring propellant charge for automobile air bag inflators, rocket motors, and
igniters therefor
4,806,180
Gas generating material
4,834,817
Gas-generating composition
4,845,377
Circuit arrangement for the actuation of a safety system
4,864,086
Vehicle deceleration sensor
4,865,635
Filter assembly for non-welded inflator device
4,865,667
Gas-generating composition
4,877,264
Aspirating/venting air bag module assembly
4,881,754
Safety device for the occupant of the central rear seat position in a motor vehicle
4,890,860
Wafer grain gas generator
4,902,036
Deflector ring for use with inflators with passive restraint devices
4,907,819
Lightweight non-welded gas generator with rolled spun lip
4,913,461
Airbag module and method of making same
4,915,410
Vehicle air bag module and method of assembly
4,915,411
Crash sensor with improved activation for stabbing primer
4,919,897
Gas generator for air bag
4,923,212
Lightweight non-welded inflator unit for automobile airbags
4,927,172
Mechanical acceleration sensor
4,928,991
Aspirating inflator assembly
4,938,140
Deceleration sensor
4,938,501
Inflator housing structure
4,944,527
Integral retainer, heat shield and assembly
4,955,638
Deceleration sensor having safety catch means
4,981,534
Occupant restraint system and composition useful therein
4,982,664
Crash sensor with snap disk release mechanism for stabbing primer
4,998,751
Two-stage automotive gas bag inflator using igniter material to delay second stage
ignition
5,002,309
Automatic mobile
5,005,486
Igniter for airbag propellant grains
5,015,311
Primary/detonator compositions suitable for use in copper cups
5,019,192
Primary/detonator compositions suitable for use in aluminum cups
5,019,220
Process for making an enhanced thermal and ignition stability azide gas generant
5,022,674
Dual pyrotechnic hybrid inflator
5,024,160
Rapid burning propellant charge for automobile air bag inflators, rocket motors, and
igniters therefor
5,031,932
Single pyrotechnic hybrid inflator
5,033,772
Hybrid inflator
5,035,757
Azide-free gas generant composition with easily filterable combustion products
5,043,030
Stab initiator
5,046,429
Ignition material packet assembly
5,058,921
Linear bilateral inflator module
5,060,974
Gas inflator apparatus
5,062,365
Rapid burning propellent charge for automobile air bag inflators, rocket motors, and
igniters therefor
5,066,038
Driver side hybrid inflator and air bag module
5,071,161
Air bag restraint system with venting means
5,076,607
Hybrid inflator
5,078,422
Gas inflator apparatus
5,089,069
Gas generating composition for air bags
5,091,992
Motorcyclist's air strips
5,092,750
Device for the compression and storage of air
5,098,123
Electrothermal inflatable restraint system
5,100,172
Inflator module
5,104,727
Air bag laminates
5,128,177
Method and apparatus of coating a vehicle frame
5,140,906
Airbag igniter having double glass seal
5,143,567
Additive approach to ballistic and slag melting point control of azide-based gas
generant compositions
5,149,129
Gas generator
5,160,386
Gas generant formulations containing poly(nitrito) metal complexes as oxidants and
method
5,161,820
Inflatable air bag safety device for motor vehicles
5,165,830
Mass transit vehicle
5,179,982
Apparatus for discharging a fluid and, more particularly, for spraying a liquid
5,184,846
Inflator assembly
5,197,758
Non-azide gas generant formulation, method, and apparatus
5,197,759
Air bag collision safety device
5,199,740
Hybrid inflator for air bag
5,203,427
Fire escape ladder with integral air cushion
5,207,450
Aspirated air cushion restraint system
5,221,107
Prefilter assembly
5,223,184
Enhanced thermal and ignition stability azide gas generant
5,224,734
Gas generator for air bags having vertical stack arrangement
5,230,287
Low cost hermetically sealed squib
5,233,141
Spring mass passenger compartment crash sensors
5,236,675
Gas generator with circumferential joints
5,243,492
Process for fabricating a hermetic coaxial feedthrough
5,246,083
Inflatable air bag for motor vehicles
5,249,826
Inertial mass safety system activation for personal vehicles
5,255,938
Tubular gas generator for an inflatable impact cushion
5,256,904
Collision determining circuit having a starting signal generating circuit
5,257,818
Apparatus for rapidly changing the temperature of a device in an inflatable restraint
system
5,257,819
Hybrid inflator
5,259,644
Ignition unit, in particular for an air bag gas generator
5,260,038
Gas generator for air bags with circumferentially disposed blades
5,263,740
Hybrid air bag inflator
5,273,311
Gas generator
5,273,722
Gas generator
5,277,440
Air bag retention device
5,286,054
Aspirating/venting motor vehicle passenger airbag module
5,294,414
Gas generator, in particular, a tubular gas generator for an air bag
5,295,709
Inertial mass safety system activation of an air bag in personal vehicles
5,305,914
Pressurized gas bottle discharge device
5,308,108
Manifold or retainer for a gas generator
5,309,138
Vehicle collision detecting method employing an acceleration sensor
5,314,203
Driver-side module attach bracket
5,320,382
Pulsed pressure source particularly adapted for vehicle occupant air bag restraint
systems
5,322,018
Surface-initiating deflagrating material
5,322,322
Side impact head strike protection system
5,324,075
Gas generator for vehicle occupant restraint
5,331,126
Pressure switch apparatus for monitoring pressure level in an enclosed chamber and
methods of calibrating same and for making a movable contact arm for use therewith
5,338,061
Air bag having double-wall construction
5,340,147
Air bag inflator assembly
5,342,081
Air bag module with top mounted bag
5,345,873
Gas bag inflator containing inhibited generant
5,345,875
Gas generator
5,345,876
Hybrid inflator
5,351,619
Gas generator ignited by lamina or film
5,351,988
Hybrid inflator with staged inflation capability
5,354,094
Air-bag arrangement
5,360,956
Acceleration sensor for vehicle
5,362,100
Control circuit for a compressed gas inflator device
5,364,127
Inflator assembly
5,372,380
Filter and method of forming
5,372,381
Air bag with inflatabe ribs
5,374,407
Gas generator with porous outer wall
5,378,011
Air bag assembly
5,378,012
Lid structure of air bag system
5,378,018
Process for inflating a gas cushion and safety system of the air bag type
5,383,388
Starting device
5,387,296
Additive approach to ballistic and slag melting point control of azide-based gas
generant compositions
5,388,322
Method of making a shatterproof air bag inflator pressure vessel
5,397,543
Gas generator
5,398,967
Air bag inflator
5,401,340
Borohydride fuels in gas generant compositions
5,403,035
Preparing air bag vehicle restraint device having cellulose containing sheet
propellant
5,403,036
Igniter for an air bag inflator
5,404,263
All-glass header assembly used in an inflator system
5,406,889
Direct laser ignition of ignition products
5,407,728
Fabric containing graft polymer thereon
5,419,875
Gas generator with novel nozzle structure
5,419,975
Inorganic ceramic paper, its method of manufacture and articles produced therefrom
5,429,691
Thermite compositions for use as gas generants comprising basic metal carbonates
and/or basic metal nitrates
5,431,101
Low cost hermetically sealed squib
5,431,102
Mechanical acceleration sensor
5,431,448
Three-point safety belt system for motor vehicles
5,437,188
Tell tale device for a pressure vessel
5,437,229
Enhanced thermal and ignition stability azide gas generant intermediates
5,439,250
Inflator for air bag device
5,439,537
Thermite compositions for use as gas generants
5,454,586
Driver side air bag module with extruded housing
5,457,991
Mechanical acceleration sensor
5,458,706
Solid pyrotechnic compositions with a thermoplastic binder and a polybutadiene
silylferrocene plasticizer
5,460,407
Restraint system for vehicle occupants having laser ignition for an air bag gas
generator
5,462,306
Gas generator for vehicle occupant restraint
5,462,308
Occupant protecting system for vehicle
5,464,246
Inflatable tubular cushions for crash protection of seated automobile occupants
5,466,002
Inflatable seat belt with leak detection device
5,466,003
Inflatable seat belt having bag filter
5,468,013
Dual air bag system for occupant restraint
5,470,104
Fluid fueled air bag inflator
5,472,534
Gas generant composition containing non-metallic salts of 5-nitrobarbituric acid
5,474,328
Stored gas hybrid driver inflator
5,480,181
Side impact head strike protection system
5,486,210
Air bag fabric containing graft polymer thereon
5,486,248
Extrudable gas generant for hybrid air bag inflation system
5,487,561
Safety bag inflation apparatus using a liquid propellant gas generator
5,489,118
Air bag inflator
5,492,364
Rupturable plastic housing for an air bag inflator
5,494,312
Autoignition of a fluid fueled inflator
5,501,152
Air bag gas generator with spontaneous ignition agent
5,503,079
Linear gas generant and filter structure for gas generator
5,504,288
Sensor for use with air bag inflator and method for making
5,507,890
Multiple layered gas generating disk for use in gas generators
5,507,891
Propellant composition for automotive safety applications
5,513,572
Hybrid inflator
5,516,146
Fastenerless airbag mounting
5,516,377
Gas generating compositions based on salts of 5-nitraminotetrazole
5,518,271
Inertial mass safety system activation of a seat belt restraint system in personal
vehicles
5,525,306
Gas generator system
5,527,062
Air bag apparatus for impact protection
5,527,067
Gas generator formed with electron beam welding
5,529,337
Air bag device
5,531,473
Fluid fuel-containing initiator device for an air bag inflator
5,531,941
Process for preparing azide-free gas generant composition
5,536,040
Inflator for side impact air bag
5,538,567
Gas generating propellant
5,538,568
Extrudable gas generant for hybrid air bag inflation system
5,542,688
Two-part igniter for gas generating compositions
5,542,695
Air bag deployment system
5,542,701
Wire track with integral sealing mechanism and inflator
5,542,997
Gas-generating mixture
5,544,687
Gas generant compositions using dicyanamide salts as fuel
5,544,913
Protective device for protecting vehicle occupant
5,544,916
Two piece inflator housing
5,547,214
Side impact soft pack air bag module
5,547,217
Air bag inflator and method of manufacture thereof
5,549,769
High temperature stable, low input energy primer/detonator
5,551,343
Special geometry generant bodies for automotive gas bag inflator
5,551,725
Vehicle airbag inflator and related method
5,552,472
Fabric containing graft polymer thereon
5,553,888
Snap-on, removable steering wheel with integral airbag housing
5,556,127
Seat mounted side impact module
5,556,132
Vehicle occupant restraint with auto ignition material
5,557,061
High temperature stable, low input energy primer/detonator
5,560,642
Driver air bag module assembly
5,562,303
Pyrotechnic mixture and gas generator for an airbag
5,564,734
Door mounted air bag assembly
5,566,543
PVC-based gas generant for hybrid gas generators
5,566,972
Air bag device
5,567,536
Inorganic ceramic paper, its method of manufacturing and articles produced
therefrom
5,570,904
Air bag inflator with movable container
5,571,988
Gas-producing material
5,575,497
Method for developing air bag for vehicle
5,575,499
Inflator for air bag device
5,577,769
Hybrid inflator for inflating air bags
5,580,086
Crash protection method and apparatus
5,582,422
Inflator mounting structure
5,582,426
Vented ignition cup in stored fluid inflator
5,584,505
Inflator assembly
5,585,597
Air bag inflator
5,586,386
Sensor for use with air bag inflator and method for making
5,586,782
Dual pressure side impact air bag
5,589,141
Use of mixed gases in hybrid air bag inflators
5,592,812
Metal complexes for use as gas generants
5,593,180
Dual chamber inflator for side impact air bag
5,597,179
Airbag inflation devices and methods
5,601,308
Inflator, inflation fluid heater and assembly methods
5,607,180
Airbag inflation devices and methods
5,607,181
Liquid-fueled inflator with a porous containment device
5,615,914
Inflatable metal bladders for automobile passenger protection
5,622,380
Variable nonazide gas generator having multiple propellant chambers
5,624,134
Gas generator formed with electron beam welding
5,628,528
Dual chamber nonazide gas generator
5,630,616
Seat frame integrated air bag inflator
5,630,618
Hybrid inflator with a valve
5,635,665
Linear gas generant and filter structure for gas generator
5,639,116
Instrument panel structure in vehicle
5,642,904
Two piece inflator housing
5,648,634
Electrical initiator
5,649,466
Method of rapidly deploying volume-displacement devices for restraining movement
of objects
5,652,389
Non-contact method and apparatus for inspection of inertia welds
5,653,464
Airbag system with self shaping airbag
5,658,011
Air bag apparatus of a tire's air pressure sensing system for a vehicle
5,659,150
Gas generating composition with cyanamide and transition metal nitrate
5,659,295
Sliding piston pressure sensing device
5,660,412
Hybrid inflator
5,660,606
Inflator filter for producing helical gas flow
5,672,843
Single charge pyrotechnic
5,673,935
Metal complexes for use as gas generants
5,681,904
Azido polymers having improved burn rate
5,682,013
Gas generant body having pressed-on burn inhibitor layer
5,683,104
Combustion moderation in an airbag inflator
5,690,356
Integrated switch for air bag deactivation
5,692,773
Air bag module with bendable base for mounting cover
5,697,638
Vehicle steering wheel arrangement
5,707,075
Protecting apparatus
5,709,724
Process for fabricating a hermetic glass-to-metal seal
5,711,546
Hybrid inflator with coaxial chamber
5,711,574
Air bag-equipped child's vehicle seat and alarm/arming system therefore
5,713,595
Inflator for vehicular air bags
5,719,351
Anti-rupture method for liquid propellant gas inflator
5,720,519
Air bag-equipped child's vehicle seat and alarm/arming system therefor
5,721,392
Pyrotechnic ignition device
5,725,245
Diffuser plate for an airbag gas generator
5,725,699
Metal complexes for use as gas generants
5,726,382
Eutectic mixtures of ammonium nitrate and amino guanidine nitrate
5,727,813
Air bag inflator
5,734,123
Extrudable gas-generating compositions
5,735,118
Using metal complex compositions as gas generants
5,738,374
Pyrotechnic gas generator for inflatable air-bag of a motor vehicle
5,741,465
Reactive waste deactivation facility and method
5,746,445
Injection termination feature
5,746,446
Plastic film airbag
5,747,696
Method of non-invasively monitoring pressure of a compressed gas in a closed
container
5,747,730
Pyrotechnic method of generating a particulate-free, non-toxic odorless and colorless
gas
5,752,717
Inflatable metal bladders for automobile passenger protection
5,755,457
Air bag device
5,756,929
Nonazide gas generating compositions
5,756,930
Process for the preparation of gas-generating compositions
5,762,369
Air bag inflator using liquid monopropellant and adaptable to produce ouputs with
various parameters
5,763,027
Insensitive munitions composite pressure vessels
5,763,817
Center gas fill inflator
5,763,821
Autoignition propellant containing superfine iron oxide
5,765,867
Air bag with externally mounted tether
5,769,452
Vehicle occupant protective air bag system
5,772,239
Airbag sub-module having fabric envelope with horn switch
5,773,754
Gas generating agent with trihydrazino triazine fuel
5,779,261
Vehicle air bag retaining arrangement
5,779,263
Integrated side impact air bag system within a seat structure
5,779,269
Propellant module assembly
5,780,768
Gas generating compositions
5,782,486
Rapid gas-fill apparatus and method
5,782,487
Gas generator
5,783,773
Low-residue azide-free gas generant composition
5,787,563
Method for assembling a compressed air bag inflator
5,788,275
Hybrid inflator
5,791,340
Resuscitator
5,791,685
Three-chambered side impact air bag
5,792,976
Rapidly deployable volume-displacement system for restraining movement of
objects
5,794,973
Dual stage air bag inflator
5,799,469
Method for the manufacture and/or filling of a two-chamber pressure pack
5,799,974
Vehicle air bag system
5,801,453
Process for preparing spherical energetic compounds
5,803,488
Inflator retainer and air bag module
5,806,885
Ignition orifice in fluid fueled inflator
5,806,886
Device for abating carbon monoxide in airbags
5,806,888
Air bag inflator
5,817,972
Iron oxide as a coolant and residue former in an organic propellant
5,821,448
Compact hybrid inflator
5,823,566
Air bag module with deployment flap
5,833,264
Inflator assembly for a vehicle air bag system
5,833,311
Add-on child seat
5,836,610
Multiple level fluid fueled airbag inflator
5,839,754
Multiple stage airbag gas generator
5,847,315
Solid solution vehicle airbag clean gas generator propellant
5,850,053
Eutectic mixtures of ammonium nitrate, guanidine nitrate and potassium perchlorate
5,851,027
Variable output driver side hybrid inflator
5,851,028
Inflator with flow diverter and heat sink
5,851,029
Gas pressure restraint, sensing and release systems
5,853,192
Variable vented housing
5,854,442
Gas generator compositions
5,856,710
Inductively coupled energy and communication apparatus
5,861,571
Gas-generative composition consisting essentially of ammonium perchlorate plus a
chlorine scavenger and an organic fuel
5,863,068
Plastic film airbag
5,868,422
Inflatabe metal bladders for automobile passenger protection
5,868,424
Substantially smoke-free and particulate-free inflator for inflatable safety restraint
system
5,872,329
Nonazide gas generant compositions
5,876,060
Seat mounted side impact module
5,884,939
Air bag system for automotive passenger seat
5,890,736
Aspiration-type air bag inflation apparatus
5,893,579
Seat mounted air bag system
5,895,070
Side impact air bag system
5,899,485
Air bag module with simplified manifold
5,899,488
Air bag arrangement and triggering process therefor
5,899,494
Deflagration venting system for airbag systems
5,904,366
Air bag apparatus
5,904,369
Catalytically plated air bag
5,907,120
Inflator for vehicle air bags
5,912,427
Semiconductor bridge explosive device
5,918,900
Hybrid inflator with bore and burst disk
5,920,029
Igniter assembly and method
5,924,727
Inflator assembly for a vehicle air bag system
5,931,495
Ignition system for a fluid-fueled inflator
5,931,499
Vehicle stabilizing apparatus
5,934,705
Two chamber inflator body
5,934,743
Impact absorbing outer body structure of a motor vehicle
5,938,233
Air bag device
5,938,235
Hybrid inflator
5,939,795
Seat sensor operating safety system for a motor vehicle
5,944,343
Miniature inflator
5,947,510
Air bag module
5,947,514
Valve controlled automotive pyrotechnic systems
5,951,040
Air bag inflator with pressure regulation
5,951,042
Vehicle occupant protection apparatus
5,951,043
Air bag inflator using liquid monopropellant and adaptable to produce outputs with
various parameters
5,962,803
Apparatus for preparing spherical energetic compounds
5,962,808
Gas generant complex oxidizers
5,967,550
Staged pyrotechnic air bag inflator
5,970,703
Metal hydrazine complexes used as gas generants
5,976,293
Method for making a case for combustible materials
5,979,328
Vehicular impact signaling device
5,984,351
Dual stage actuation system
5,984,352
Air bag inflator with pressure regulation
5,988,069
Electric initiator having a sealing material forming a ceramic to metal seal
5,988,438
Apparatus for rapid inflation of inflatable object and related method
5,997,666
GN, AGN and KP gas generator composition
6,000,718
End cap assembly for airbag inflator
6,004,410
Apparatus comprising an inflatable vehicle occupant protection device and a gas
generating composition therefor
6,009,809
Bridgewire initiator
6,012,737
Vehicle occupant protection apparatus
6,017,404
Nonazide ammonium nitrate based gas generant compositions that burn at ambient
pressure
6,019,389
Air bag inflator
6,019,390
Multiple panel airbag
6,020,655
Control circuit for an airbag release unit
6,029,558
Reactive personnel protection system
6,029,932
Detonating valve for releasing openings of air bag landing systems
6,036,226
Inflator capable of modulation air bag inflation rate in a vehicle occupant restraint
apparatus
6,039,347
Liquid propellant airbag inflator with dual telescoping pistons
6,039,348
Variable output inflator with adaptive heat sinking
6,039,820
Metal complexes for use as gas generants
6,042,147
Air-bag device
6,045,638
Monopropellant and propellant compositions including mono and
polyaminoguanidine dinitrate
6,047,541
HAN TEAN (xm-46) mixing gas generator propellant tank pressurizer for launch
vehicles and spacecraft
6,050,598
Apparatus for and method of monitoring the mass quantity and density of a fluid in a
closed container, and a vehicular air bag system incorporating such apparatus
6,053,110
Airbag generant wafer design with I-beam construction
6,053,270
Steering angle correcting system in vehicle
6,059,906
Methods for preparing age-stabilized propellant compositions
6,062,142
Autoignition system for inflator devices with separator that melts
6,062,143
Distributed charge inflator system
6,065,773
Gas pressure restraint, sensing and release systems
6,068,287
Electronic device and method for actuating a passenger-protection system
6,073,438
Preparation of eutectic mixtures of ammonium nitrate and amino guanidine nitrate
6,073,961
Inflatable side airbag curtain module
6,073,963
Initiator with injection molded insert member
6,074,502
Smokeless gas generant compositions
6,076,468
Solid propellant/water type hybrid gas generator
6,079,739
Pyrotechnic gas generator with an adaptable flow rate for air bags
6,086,095
Airbag cushion exhibiting low seam and fabric usage and simultaneously high
available inflation volume
6,093,269
Pyrotechnic gas generant composition including high oxygen balance fuel
6,095,558
Gas generator made of metal sheets for protective devices of motor vehicles
passengers
6,095,561
Multi-chamber inflator
6,099,033
Compressed air bag inflator
6,106,038
System for collision damage reduction
6,109,647
Seat-occupant restraining apparatus
6,116,641
Dual level gas generator
6,117,255
Gas generating composition comprising guanylurea dinitramide
6,120,058
Air bag inflator
6,120,626
Dispensing fibrous cellulose material
6,123,359
Inflator for use with gas generant compositions containing guanidines
6,123,790
Nonazide ammonium nitrate based gas generant compositions that burn at ambient
pressure
6,126,197
Lightweight discoidal filterless air bag inflator
6,131,949
Venting systems for inflatables
6,139,054
Reduced smoke gas generant with improved temperature stability
6,142,056
Variable thrust cartridge
6,142,508
Side impact air bag system
6,142,511
Inflatable passenger restraint and inflator therefor
6,142,515
Air bag inflator with heat sink and retainer
6,142,518
Dual inflator apparatus including pyrotechnic inflator
6,143,103
Gas generating material for vehicle occupant protection device
6,145,876
Vehicle inflator with stored gas for supplementing inflation
6,149,184
Simplified driver side air bag assembly
6,149,194
Plastic film airbag
6,155,600
Safety air bag inflation device
6,156,137
Gas generative compositions
6,156,230
Metal oxide containing gas generating composition
6,165,295
Gas-generating liquid compositions (PERSOL 1)
6,170,594
Method and apparatus for reducing vehicle rollover
6,170,868
Hybrid inflator
6,176,517
Gas generating apparatus
6,176,950
Ammonium nitrate and paraffinic material based gas generating propellants
6,179,326
Efficient airbag system
6,182,782
Device for reducing the impact of pedestrians
6,186,540
Method of filling an empty, flexible container, and a container device
6,186,541
Air bag arrangement with gas filtration
6,186,543
Air bag system for automotive passenger seat
6,189,919
Steering column arrangement for occupant protection
6,189,922
Inflator with multiple initiators
6,196,577
Air bag apparatus
6,196,581
Airbag inflator and an airbag apparatus
6,196,582
Variable output inflator for an air bag
6,196,583
Gas generator with cooling device
6,199,900
Vehicle safety collision headrest system
6,199,905
High thermal efficiency inflator and passive restraints incorporating same
6,203,061
Variable output air bag module with PAV heat sink
6,210,505
High gas yield non-azide gas generants
6,213,496
Airbag device with inner and outer bags
6,213,502
Air bag module with variable inflation
6,214,138
Ignition enhancer composition for an airbag inflator
6,217,067
Flame protection for a gas bag
6,218,577
Enegetic hydrazinium salts
6,220,309
Inflatable fabrics comprising basket-woven attachment points between fabric panels
6,220,626
Air belt apparatus
6,224,097
Inflator for inflatable restraint
6,224,099
Supplemental-restraint-system gas generating device with water-soluble polymeric
binder
6,224,100
Air bag apparatus, air bag folding method, and air-bag folding device
6,227,565
Air bag inflator with pressure regulation
6,227,566
Airbag device with inflator
6,228,191
Gas-generating preparation with iron and/or copper carbonate
6,230,491
Gas-generating liquid compositions (persol 1)
6,230,501
Ergonomic systems and methods providing intelligent adaptive surfaces and
temperature control
6,234,523
Dual type inflator device wherein light-emitting phenomenon is suppressed
6,235,132
Gas generating compositions
6,237,941
Inflatable side airbag curtain module
6,237,950
Staged air bag inflator
6,237,951
Device for letting pressurized gas stream into a safety device
6,241,281
Metal complexes for use as gas generants
6,247,726
Air bag module with variable inflation
6,250,668
Tubular airbag, method of making the same and occupant protection system
including the same
6,254,164
Vehicle occupant protection system
6,257,527
Hypersonic and orbital vehicles system
6,257,617
Air bag inflator with pressure regulation
6,266,926
Gas generator deployed occupant protection apparatus and method
6,270,113
Side air bag system
6,274,064
Metal oxide containing gas generating composition
6,274,252
Hermetic glass-to-metal seal useful in headers for airbags
6,277,221
Propellant compositions with salts and complexes of lanthanide and rare earth
elements
6,283,543
Motor vehicle roof
6,287,400
Gas generant composition
6,290,256
Air bag inflator with pressure regulation
6,293,581
Occupant restraint device
6,293,582
Control system for air bags in different vehicle locations
6,294,487
Airbag fabric processing very low cover factor
6,296,274
Apparatus for inflating a side curtain
6,298,787
Non-lethal kinetic energy weapon system and method
6,299,203
Airbag device in a vehicle and method for activating an airbag device
6,299,204
Vehicle restraint system comprising an airbag having an integrated mouth
6,299,205
Vehicle restraint system comprising an airbag having a looped pocket for inflation
canister disposition
6,299,206
Vehicle restraint system comprising an airbag having an integrated mouth
6,299,711
Gas-generating liquid compositions (OXSOL 3)
6,299,965
Inflatable fabrics comprising peel seams which become shear seams upon inflation
6,306,232
Thermally stable nonazide automotive airbag propellants
6,314,887
Microelectromechanical systems (MEMS)-type high-capacity inertial-switching
device
6,315,322
Air bag inflator
6,315,847
Water-free preparation of igniter granules for waterless extrusion processes
6,315,930
Method for making a propellant having a relatively low burn rate exponent and high
gas yield for use in a vehicle inflator
6,325,408
Air bag attachment arrangement
6,328,830
Metal oxide-free 5-aminotetrazole-based gas generating composition
6,328,831
Gas-generating liquid compositions (Perhan)
6,328,906
Chemical delivery systems for fire suppression
6,331,220
Gas-generating liquid compositions (PERSOL 2)
6,334,917
Propellant compositions for gas generating apparatus
6,334,961
Low ash gas generant and ignition compositions for vehicle occupant passive
restraint systems
6,336,657
Seat-occupant restraining apparatus
6,340,175
Air bag assemblies with foamed energetic igniters
6,341,562
Initiator assembly with activation circuitry
6,343,812
Method for fixing an adjustable automobile steering column and device for carrying
out the method
6,352,030
Gas generating eject motor
6,361,064
Inflator seal retainer for an air bag module
6,361,631
Liquid monopropellants for passive vehicle occupant restraint systems
6,363,307
Control system for occupant protection apparatus
6,364,350
Motor vehicle occupant safety device
6,364,353
Dual stage air bag inflator
6,364,356
Airbag cushion comprising sewn reinforcement seams
6,364,975
Ammonium nitrate propellants
6,368,431
Air bag inflator
6,371,517
Adaptive inflation mechanism
6,373,384
Inflatable security device
6,375,219
Airbag cushion exhibiting low fabric usage and simultaneously high available
inflation volume
6,379,627
Gas generator
6,382,660
Air bag assembly
6,400,145
Seat belt tension sensor, methods of integration and attachment
6,402,191
Inflatable air bag system which serves as a protective wall in front of a vehicle
sidewall
6,409,213
Adaptive inflation mechanism
6,409,214
Airbag inflator and an airbag apparatus
6,412,391
Reactive personnel protection system and method
6,416,600
Process for the production of an exothermically reacting composition
6,417,579
Electrical system with security battery disconnection
6,418,870
Torpedo launch mechanism and method
6,419,262
Occupant protective device located in the steering wheel of a motor vehicle
6,422,601
Dual chamber inflator
6,425,601
Air bag module
6,427,599
Pyrotechnic compositions and uses therefore
6,428,041
Airbag system for a motor vehicle
6,431,582
Simplified driver side air bag assembly
6,431,594
Air bag inflator with mechanism for deactivation of second stage and autoignition
6,431,597
Reduced smoke gas generant with improved mechanical stability
6,435,552
Method for the gas-inflation articles
6,439,603
Air bag module with variable inflation
6,447,007
Compact dual nozzle air bag inflator
6,450,529
Inflatable side air bag curtain module with chamber separators
6,450,573
Anti-submarine vehicle seat device
6,454,299
Airbag device
6,454,306
Gas generator for seat belt pretensioner
6,454,887
Gas generant for air bag
6,457,741
Seat mounted side air bag
6,464,253
Vehicular restraint system
6,472,033
Airbag cushion exhibiting low seam usage and simultaneously high available
inflation volume
6,472,352
Aqueous lubricant and process for cold forming metal, with improved formed
surface quality
6,474,684
Dual stage inflator
6,475,312
Method of formulating a gas generant composition
6,477,957
Ignition device for a safety system
6,478,329
Air bag
6,481,746
Metal hydrazine complexes for use as gas generants
6,481,747
Cool, low effluent pyrotechnic inflator
6,485,403
Air bag system of folding an air bag
6,485,588
Autoignition material additive
6,487,974
Inflator
6,488,310
Hybrid inflator
6,489,006
Inflatable fabrics comprising peel seams which become shear seams upon inflation
6,497,429
Airbag apparatus
6,497,774
Gas generant for air bag
6,508,894
Insensitive propellant formulations containing energetic thermoplastic elastomers
6,511,094
Automotive vehicle air bag system
6,513,602
Gas generating device
6,513,834
Monopropellant smokeless gas generant materials
6,513,835
Automotive vehicle air bag system
6,513,880
Power actuator suitable for vehicle occupant restraint systems
6,523,855
Air bag, method of manufacture and system therefor
6,530,543
Hypersonic and orbital vehicles system
6,533,316
Automotive electronic safety network
6,533,318
Air bag system for automotive passenger seat
6,536,798
Controlling activation of restraint devices in a vehicle
6,539,869
Heat transfer initiator
6,543,805
Dual stage air bag inflator
6,547,275
Air bag gas generator and air bag device
6,547,277
Two chamber gas generator
6,556,119
High current intensity fuse device
6,557,474
Initiator header subassembly for inflation devices
6,560,832
Structurally efficient airbag cushion exhibiting high available inflation volume
6,566,869
Seat belt tension sensor, methods of integration and attachment
6,568,703
Interference fit attachment for a rounded member
6,572,136
Automotive air bag system
6,572,144
Airbag
6,574,962
KOH flue gas recirculation power plant with waste heat and byproduct recovery
6,581,963
Catalytic filter for an inflator
6,581,964
Gas bag module
6,584,911
Initiators for air bag inflators
6,585,290
Diffuser for an air bag
6,595,102
Reactive personnel protection system and method
6,595,244
Inflatable fabrics having woven attachment points between fabric panels
6,595,548
Air bag system, method of folding air bag and air bag folding apparatus
6,598,899
Inflatable seat belt using MEMS devices
6,598,901
Gas generator for air bag and air bag apparatus
6,598,902
Welded airbag cushion comprising sewn reinforcement seams
6,601,872
Compact multi-level inflator
6,604,599
Anti-submarine vehicle occupant restraint system
6,605,233
Gas generant composition with coolant
6,607,213
Gas generating device for air bag and air bag inflating method
6,612,243
Fire extinguisher
6,612,610
Air bag device
6,619,692
Air bag inflators
6,623,033
Airbag inflation control system and method
6,626,455
Deformable air bag module housing
6,626,457
Curtain airbag
6,629,575
Vehicle occupant emergency system
6,640,721
Non-lethal airbag munition
6,641,074
Seat belt webbing pretensioner using MEMS devices
6,644,206
Electrically actuatable initiator with output charge
6,648,366
Driver side air bag with particulate diverter
6,648,367
Integrated occupant protection system
6,650,528
Ignition device for a safety system
6,659,500
Multi-chamber inflator
6,666,934
Extruded hydroxy terminated polybutadiene gas generating material
6,669,226
Air bag module with oppositely aligned inflators
6,669,229
Automotive vehicle air bag system
6,669,231
Adaptive venting for an air bag module
6,672,220
Apparatus and method for dispersing munitions from a projectile
6,672,618
Multiple panel airbag and method
6,673,172
Gas generant compositions exhibiting low autoignition temperatures and methods of
generating gases therefrom
6,673,728
Low permeability, high strength timing fabric for utilization within airbag inflation
modules
6,679,522
Airbag
6,688,231
Cord-type gas generator
6,688,555
Anti-hijacking system
6,695,259
Communication system, communication receiving device and communication
terminal in the system
6,701,849
Dual stage air bag inflator with secondary propellant cap
6,702,323
Air bag module with pressure regulator
6,705,637
Inflator
6,709,006
Air bag device
6,713,412
Low permeability, high strength timing fabric for utilization within airbag inflation
modules
6,715,371
Method of testing an airbag module
6,715,790
Side curtain air bag
6,718,884
Initiator assembly
6,719,323
Air bag apparatus and steering wheel
6,726,788
Preparation of strengthened ammonium nitrate propellants
6,733,036
Automotive electronic safety network
6,739,362
Hybrid-gas generator, in particular for filling a gas bag
6,746,044
Actuatable fastener for air bag module vent
6,749,218
Externally deployed airbag system
6,755,273
Combined airbag inflation and occupant displacement enabling method and
apparatus
6,758,199
Tuned power ignition system
6,764,096
Dual chamber inflator
6,767,030
Air bag system for automotive passenger seat
6,779,464
Gas generating composition
6,789,702
System for dispensing multi-component products
6,789,820
Variable output inflator
6,793,244
Multi-stage expansion tire hybrid inflator
6,796,579
Gas generator with airbag device
6,799,776
Hybrid inflator
6,805,376
Inflator with shock wave generator
6,805,377
Inflator
6,805,380
Vehicular passive safety device
6,808,204
Hybrid inflator
6,823,244
Vehicle part control system including electronic sensors
6,823,645
Radial tube air bag folding apparatus and method
6,834,885
Inflator
6,835,102
Connector provided with front holder
6,837,517
Multiple panel airbag and method
6,843,503
Controlled venting apparatus and method therefor
6,851,709
Multistage-inflating type hybrid inflator
6,854,762
Airbag system
6,860,510
Multistage inflating-type hybrid inflator
6,860,511
Multiple chamber dual stage inflator
6,860,951
Gas generating compositions
6,863,303
Hybrid inflator
6,865,825
Ergonomic systems and methods providing intelligent adaptive surfaces and
temperature control
6,871,871
Air bag inflator
6,874,544
System for dispensing multi-component products
6,877,435
Dual-stage gas generator utilizing eco-friendly gas generant formulation
6,877,698
Aircraft evacuation slide inflation system using a stored liquified gas capable of
thermal decomposition
6,883,827
Modular air bag cushion system
6,886,469
Distributed charge inflator system
6,887,326
Nonazide gas generant compositions
6,889,613
Variable output inflator
6,889,614
Air bag inflator
6,892,983
Anti-hijacking system
6,905,135
Inflator system
6,908,149
Anti-submarine vehicle seat device
6,910,713
Airbag cushion exhibiting low fabric usage and simultaneously high available
inflation volume
6,913,319
Power actuator
6,913,661
Ammonium nitrate propellants and methods for preparing the same
6,918,340
Dual-stage gas generator utilizing eco-friendly gas generant formulation for military
applications
6,918,459
Method and apparatus for deploying airbags
6,918,611
System and method for controlling an inflatable cushion
6,918,976
Gas generating composition
6,923,342
Systems for dispensing multi-component products
6,926,303
Inflatable vehicle occupant protection device with inflation fluid deflector
6,926,792
Method of fabricating an air-bag and an air-bag fabricated by the method
6,936,303
Electric type initiator and gas generator
6,945,559
Method and apparatus for air bag venting
6,951,317
Vehicle, lightweight pneumatic pilot valve and related systems therefor
6,953,823
Elastomeric insulating composition for a solid propellant rocket motor
6,962,113
Segmented-rod warhead
6,962,363
Multiple chamber airbags and methods
6,966,373
Inflatable sealing assembly and method for sealing off an inside of a flow carrier
6,969,435
Metal complexes for use as gas generants
6,979,022
Flexible inflator with co-extruded propellant and moisture barrier
6,979,024
Gas generator for seat belt pretensioner
6,983,955
Air bag inflators
6,988,026
Wireless and powerless sensor and interrogator
6,991,254
Airbag system
6,997,477
Inflator
7,004,074
Controlled fluid energy delivery burst cartridge
7,007,972
Method and airbag inflation apparatus employing magnetic fluid
7,017,944
Multiple chamber inflator
7,025,378
Air bag and method for making an air bag
7,042,696
Systems and methods using an electrified projectile
7,048,304
Multiple panel airbag and method
7,052,041
Gas generator and gas generant packet used therein
7,057,872
Systems and methods for immobilization using selected electrodes
7,059,633
Hybrid gas inflator
7,059,635
Hybrid inflator
7,069,961
Inflatable fabrics comprising basket-woven attachment points between fabric panels
7,070,204
Programmable gas generator using microcells
7,073,820
Inflator
7,080,854
Pyrotechnic linear inflator
7,080,855
Safety steering column, motor vehicle with a safety system and safety method
7,082,359
Vehicular information and monitoring system and methods
7,089,099
Sensor assemblies
7,097,203
Inflator
7,103,460
System and method for vehicle diagnostics
7,104,569
Air bag module with pressure regulator
7,107,706
Ergonomic systems and methods providing intelligent adaptive surfaces and
temperature control
7,111,871
Automotive vehicle air bag system
7,114,744
Airbag apparatus and related method
7,114,874
Security barrier
7,118,129
Air bag system for automotive passenger seat
[0000]
TABLE II
FIRE SUPPRESSOR APPARATUSES AND MEHTODS
Publication
Number
Title
20020023967
Effervescent liquid fine mist apparatus and method
20020070035
Method and system for extinguishing fire in an enclosed space
20020139542
Process and installation for fighting a fire in an aircraft compartment and aircraft
equipped with such an installation
20020144824
Microemulsion mists as fire suppression agents
20030006046
Fire extinguishing ball
20030019641
Fire suppression system and method for an interior area of an aircraft lavatory
waste container fire protection
20030051886
Fire suppression using water mist with ultrafine size droplets
20030062173
Method of fire extinguishment with gas and fire-extinguising equipment
20030062175
Fire suppression system and solid propellant aerosol generator for use therein
20030141082
Portable breathable fire extinguishing liquefied gas delivery system
20030150623
Fire extinguishing spray nozzle
20030155134
Fire blanket
20030205390
Method and apparatus for distributing granular material
20040016551
Methods and apparatus for extinguishing fires
20040020665
Helium gas total flood fire suppression system
20040020666
Explosion suppression system
20040045725
Retrofitted non-halon fire suppression system and method of retrofitting existing
halon based systems
20040069505
Method and apparatus to extinguishing fire in areas beyond the reach of standard
fire equipments
20040089460
System and method for suppressing fires
20040129435
Flame suppression agent, system and uses
20040140105
Combustion supression system
20040163826
Fire protection systems and methods
20040188103
Thermally activated fire suppression system
20040194974
Pressurization system for fire extinguishers
20040194977
Self-modulating inert gas fire suppression system
20040226726
Vehicle fire extinguisher
20040262018
Fire extinguishing cover
20050016741
Fire extinguishing system for large structures
20050023007
Methods using fluoroketones for: extinguishing fire; preventing fire; and
reducing or eliminating the flammability of a flammable working fluid
20050051345
Fire blanket
20050077054
Methods and apparatus for extinguishing fires
20050115722
Method and apparatus for suppression of fires
20050139363
Fire suppression delivery system
20050139365
System and method for suppressing fires
20050139366
Method and apparatus for extinguishing a fire in an enclosed space
20050139367
Fire extinguishing device and method
20050150663
Fire extinguishing device
20050178566
Fire extinguisher with means for preventing freezing at outlet
20050183869
Fire-suppression system for an aircraft
20050189123
System and method for suppressing fires
20050217871
Fire suppression system and method for an interior area of an aircraft lavatory
waste container fire protection
20050257937
Device for extinguishing fire by injection of a gas generated by the combustion of
a pyrotechnic block
20050263299
Fire extinguishing method by gas and extingushing device
20060011356
Fire-resistant tent for building structures
20060076430
Methods and systems for simulating multi-phase fluid flows, including fire
suppressant flows
20060175429
Fire fighting system
20060196681
Fire Suppression Using Water Mist with Ultrafine Size Droplets
20060201687
Self-contained automated residential fire extinguisher
20060213673
Method of preventing fire in computer room and other enclosed facilities
20060231270
Automotive Fire Suppression System With Dynamic Reservoir Seal
3,930,541
Flame prevention system for fuel tank fires
3,952,809
Series to parallel transfer circuit for initiator string
3,964,390
Bursting disc assembly
3,965,988
Fire extinguishing method and apparatus
3,967,255
Flame detection system
3,980,139
Fire extinguishing bomb for putting out fires
3,986,560
Fire protection means
3,990,516
Pneumatic time delay valve
4,006,780
Rupturing head for fire extinguishers
4,013,128
Modular fire protection system
4,020,904
Dispersion nozzle with removable dispersion element
4,020,905
Construction of fire extinguishers
4,046,156
Explosion discharge valve
4,055,844
Detection system
4,064,944
Apparatus for fire extinguishing system for floating-roof tanks
4,069,873
Apparatus for fire extinguishing system for floating-roof tanks
4,073,464
Cylinder valve for gas fire extinguishing system
4,082,148
Fire protection system
4,090,567
Fire fighting helicopter
4,109,726
Gas fire extinguishing system
4,110,812
Non-recurrent pulse generator
4,121,666
Fuel (flammable liquid) tank fire extinguisher
4,126,184
Instantaneous release, dual valve for fire suppression apparatus
4,129,185
Fire suppression system
4,132,271
Fragment prevention screen for explodable fire suppressant panels
4,159,744
Fire extinguishant mechanism
4,183,409
Automatic fire-extinguishing system
4,188,856
Compressed-gas-actuated switching device
4,194,571
Fire suppression mechanism for military vehicles
4,199,029
Multiple, independently actuatable fire suppression devices each having
individual actuating power source
4,201,178
Engine flameproofing
4,213,567
Discharge nozzle for fluorinated hydrocarbon fire suppression system
4,217,959
Electrically controlled fluid disperser for a fire extinguishing system
4,232,742
Flame-guard for electrical installations
4,262,749
Fire suppression bladder system for fuel tanks
4,263,971
Fire and explosion suppression apparatus
4,267,890
Fire extinguishing system including sensor comparable to determine charge
4,270,613
Fire and explosion detection and suppression system
4,275,860
Full span shipboard fueling system for aircraft
4,281,717
Expolosion suppression system for fire or expolosion susceptible enclosures
4,285,403
Explosive fire extinguisher
4,289,207
Fire extinguishing system
4,296,817
Fire suppression system for military tanks
4,305,469
Fire extinguishing system having a discharge valve and a distribution valve
actuated by a pneumatic actuator
4,319,640
Gas generator-actuated fire suppressant mechanism
4,328,867
Fire extinguishers
4,328,868
Fire suppressant impact diffuser
4,332,368
Valve
4,347,901
Fire extinguishing system for aircraft
4,351,394
Method and system for aircraft fire protection
4,390,069
Trifluorobromomethane foam fire fighting system
4,394,868
Horizontal discharge assembly for vertically oriented fire extinguisher
4,411,318
Fire-extinguishing waste receptacle
4,420,047
Stowable fire suppression system for aircraft cabins and the like
4,436,159
Manual/electric activated squib actuated discharge valve for fire extinguishers
4,462,319
Method and apparatus for safely controlling explosions in black liquor recovery
boilers
4,487,266
Explosion suppression apparatus
4,488,603
A compact and highly mobile fire-fighting vehicle
4,499,952
Fire and explosion detection and suppression system and actuation circuitry
therefor
4,520,871
Fire extinguishing system
4,531,588
Fire suppression system
4,532,996
Automatic fire extinguisher with acoustic alarm
4,567,948
Fire extinguisher valve
4,569,399
Safety enclosure
4,577,544
Ultrafast thermal actuator
4,580,638
Fire suppression and control system
4,583,597
Fire and explosion detection and suppression system
4,589,496
Fire suppressant valve using a floating poppet
4,592,301
Fire extinguisher support mechanism incorporating an audible alarm
4,597,451
Fire and explosion detection and suppression
4,606,832
Fire extinguishing composition
4,616,694
Fireproof cabinet system for electronic equipment
4,617,174
Automatic autonomous apparatus for the fast production of polyurethane foam
4,622,209
Process and apparatus for reducing the chances of ignition and explosion due to
the decomposition of high-pressure industrial process gases
4,625,808
Device for coupling fire extinguishers to closed-off compartments
4,630,684
Fire sensing and suppression method and system responsive to optical radiation
and mechanical wave energy
4,633,967
Circumbendibus safety system for a vehicle
4,637,472
Rapid discharge extinguisher
4,637,473
Fire suppression system
4,643,260
Fire suppression system with controlled secondary extinguishant discharge
4,645,009
Method and means for producing and dispensing extinguishing fluids
4,646,848
Fire suppression system for an aircraft
4,650,003
Light path heat detector
4,662,454
Foam extinguishing system
4,664,199
Method and apparatus for extinguishing fires in flammable liquid filled storage
vessels
4,668,407
Fire extinguishing composition and method for preparing same
4,676,319
Fire fighting tool and method
4,691,783
Automatic modular fire extinguisher system for computer rooms
4,693,320
Fire suppression test apparatus
4,697,643
Temperature-compensated pressure controller, operationally reliable extinguisher
provided with such a pressure controller and process for filling such a pressure
controller
4,702,322
Explosion suppression system
4,709,763
Self-activating fire extinguisher
4,711,307
Compact self-contained fire extinguisher
4,718,497
Fire and explosion detection and suppression
4,719,973
Fire and explosion detection and suppression
4,726,426
Fire extinguishment system for an aircraft passenger cabin
4,729,434
Portable fire-fighting apparatus
4,760,886
Fast discharge fire extinguisher and a method of fabricating same
4,763,731
Fire suppression system for aircraft
4,779,683
Discharge control head for aircraft fire extinguishant containers
4,805,701
Fire extinguisher and alarm apparatus
4,815,541
Fire extinguisher
4,826,610
Fire extinguishant
4,830,114
Self-activating fire extinguisher
4,830,116
Fire extinguishing system
4,830,762
Method for fire extinguishment of liquid chlorosilane compound
4,834,187
Explosion suppression system
4,854,388
Fire extinguishing apparatus
4,854,389
Linear fire extinguisher
4,856,762
Fire retardant gas spring assembly for a passenger seat control
4,889,189
Fire suppressant mechanism and method for sizing same
4,893,680
Fire suppression activator
4,895,208
Elevator cab fire extinguishing system
4,899,826
Combination fire extinguisher and tire sealer
4,938,293
Linear fire extinguisher
4,951,755
Manual actuator
4,953,623
Protected L-shaped environment using single chemical nozzle
4,953,624
Cylinder pressure switch for automatic fire protection systems
4,954,271
Non-toxic fire extinguishant
4,964,469
Device for broadcasting dry material by explosive force
4,970,936
Gas reservoir actuation device
4,986,366
Method and apparatus for suppressing explosions and fires
4,989,675
Spray nozzle for fire control
4,991,657
Fire suppression system
5,014,790
Method and apparatus for fire control
5,016,715
Elevator cab fire extinguishing system
5,018,586
Fire suppression system for a decorative tree
5,031,701
Suppressant discharge nozzle for explosion protection system
5,036,924
Container fire nozzle hole adapter
5,038,866
Powder discharge apparatus
5,040,609
Fire extinguishing composition and process
5,050,683
Extinguishing rocket/missile solid propellants
5,052,493
Fire suppression systems for vehicles
5,053,147
Methods and compositions for extinguishing fires
5,062,486
Firefighter's barrier penetrator and agent injector
5,069,291
Method and apparatus for suppressing explosions and fires and preventing
reignition thereof
5,088,560
Zero force fire extinguisher
5,090,482
Method and apparatus for extinguishing fires
5,093,013
Ozone friendly fire-extinguishing agents
5,099,976
Fire extinguishing apparatus for compressors
5,102,557
Fire extinguishing agents for streaming applications
5,113,947
Fire extinguishing methods and compositions utilizing 2-chloro-1,1,1,2-
tetrafluoroethane
5,115,867
Dual linear fire extinguisher
5,115,868
Fire extinguishing composition and process
5,119,877
Explosion suppression system
5,119,878
Impact activated vehicle-based fire extinguisher
5,121,797
Methods and apparatus for shutting in a burning oil well
5,124,053
Fire extinguishing methods and blends utilizing hydrofluorocarbons
5,135,054
Fire extinguishing agents for flooding applications
5,146,996
Apparatus and method for thrusting a cover over a target area
5,152,345
Fire extinguishing tool
5,154,237
Detonation suppression
5,154,238
Vehicular fire protection apparatus
5,158,138
Apparatus for shutting in a burning oil well
5,163,517
Fire extinguishing systems
5,174,384
Transport unit for fluid or solid materials or devices, and method
5,183,117
Fire extinguisher
5,211,245
Vehicle mounted aerial lift
5,211,246
Scouring method and system for suppressing fire in an enclosed area
5,224,550
Explosion suppression system
5,232,053
Explosion suppression system
5,244,021
Fuel transfer container
5,249,631
Water powered mobile robot
5,275,243
Dry powder and liquid method and apparatus for extinguishing fire
5,275,244
Apparatus and process for extinguishing fires with a noncombustible fluid in
liquid and gaseous states
5,276,433
Methods and apparatus for temperature sensing
5,277,256
Firefighter's nozzle
5,301,756
Vehicle mounted aerial lift
5,305,957
Process and apparatus for the fine dispersion of liquids or powders in a gaseous
medium
5,340,490
Azeotrope-like compositions of trifluoromethane and carbon dioxide or
hexafluoroethane and carbon dioxide
5,361,847
Failsafe phial-type fire extinguishing system
5,368,106
Fire-fighting tool particularly for shipboard fires and the like
5,370,189
Fire extinguisher bottle with pick-up tube
5,393,438
Fire extinguishing composition and process
5,402,967
Apparatus for supplying water to aircraft cabin spray systems
5,409,067
Portable fire fighting tool
5,423,384
Apparatus for suppressing a fire
5,423,385
Fire extinguishing methods and systems
5,425,426
Fire extinguishing methods and systems
5,425,886
On demand, non-halon, fire extinguishing systems
5,441,114
Portable system for extinguishing a fire
5,449,041
Apparatus and method for suppressing a fire
5,458,202
Pressurized extinguishant release device with rolling diaphragm
5,465,795
Fire suppressing apparatus for generating steam from a water-ice mixture
5,492,179
System for extinguishing a fire in a volume for delivery from a distance
5,492,180
Painting wall surfaces with an ignitable solid-fuel composition which generates a
fire-extinguishing particulate aerosol
5,495,893
Apparatus and method to control deflagration of gases
5,501,284
Inflatable bag fire extinguishing system
5,505,383
Fire protection nozzle
5,511,621
Local flooding fine water spray fire suppression system using recirculation
principles
5,518,075
Fire extinguisher
5,534,164
Non-toxic, environmentally benign fire extinguishants
5,573,067
Apparatus for extinguishing an oil well fire
5,575,341
Mechanical foam fire fighting equipment and method
5,588,493
Fire extinguishing methods and systems
5,588,987
Discharge stream conditioner and method
5,597,044
Method for dispersing an atomized liquid stream
5,609,210
Apparatus and method for suppressing a fire
5,609,787
Method for extinguishing fire
5,610,359
Method of generating non-toxic smoke
5,613,562
Apparatus for suppressing a fire
5,615,742
Noncombustible hydrogen gas containing atmospheres and their production
5,617,923
Modular fire extinguishing apparatus for an enclosed environment
5,626,786
Labile bromine fire suppressants
5,647,438
Explosion suppressant dispersion nozzle
5,651,417
Base for a fire-fighting tool
5,664,631
Apparatus for impulse fire extinguishing
5,678,638
Spark and flame suppression system
5,685,376
System and method utilizing low-pressure nozzles for extinguishing fires
5,718,293
Fire extinguishing process and composition
5,718,294
Fire suppression or explosion protection system having a manual actuator for an
electrically responsive initiator or gas-generating cartridge activator
5,727,635
Vehicular and marine fire suppression system
5,759,430
Clean, tropodegradable agents with low ozone depletion and global warming
potentials to protect against fires and explosions
5,775,434
Fire fighting method and installation for extinguishing an elongated object
5,785,126
Method of extinguishing of fire in open or closed spaces and means for
performing the method
5,785,127
User back-mounted fire suppressor
5,808,541
Hazard detection, warning, and response system
5,826,664
Active fire and explosion suppression system employing a recloseable valve
5,833,874
Fire extinguishing gels and methods of preparation and use thereof
5,845,714
Method and installation for fire extinguishing using a combination of liquid fog
and a non-combustible gas
5,845,716
Method and apparatus for dispensing liquid with gas
5,848,650
Vehicular engine combustion suppression method
5,848,652
Engine fire extinguishment system
5,850,876
Apparatus and system for the storage and supply of liquid CO.sub.2 at low
pressure for extinguishing of fires
5,856,587
Flame extinguishing compositions
5,857,627
Foam-forming nozzle
5,862,867
Gas-liquid mixture as well as unit and method for the use thereof
5,881,817
Cold compressed air foam fire control apparatus
5,884,710
Liquid pyrotechnic fire extinguishing composition producing a large amount of
water vapor
5,894,891
Method and device for extinguishing fires
5,909,776
Fire extinguishers
5,913,367
Aircraft penetrator
5,918,680
Water spray cooling system for extinguishment and post fire suppression of
compartment fires
5,919,393
Fire extinguishing process and composition
5,921,322
Device for regulating speed of deployment of sprinkler heads in preactive
sprinkler systems
5,934,379
Method and apparatus for detection and prevention of fire hazard
5,934,380
Apparatus for preparing and disseminating novel fire extinguishing agents
5,947,207
Dual sprinkler system
5,954,138
Fire extinguisher valve and fire-extinguishing equipment
5,971,080
Quick response dry pipe sprinkler system
5,975,213
Fire suppression device
5,984,016
Fire extinguisher for closed spaces
5,992,528
Inflator based fire suppression system
5,993,682
Hydrobromocarbon blends to protect against fires and explosions
6,003,608
Fire suppression system for an enclosed space
6,012,531
Fire extinguishing bomb
6,016,874
Compact affordable inert gas fire extinguishing system
6,019,177
Methods for suppressing flame
6,024,889
Chemically active fire suppression composition
6,029,751
Automatic fire suppression apparatus and method
6,032,745
Valve for fire suppression device
6,047,777
Method and device for suppressing an explosion-like fire, in particular of
hydrocarbons
6,053,256
Fire extinguishing system
6,053,256
Fire extinguishing system
6,056,063
Thermo-controlled, self-explosive fire extinguisher
6,065,546
Fire extinguishing and smoke eliminating apparatus and method using water mist
6,065,547
Apparatus and method for fire suppression
6,068,058
Apparatus and method for fire supression
6,076,610
Vehicular fire extinguishing device
6,082,464
Dual stage fire extinguisher
6,089,324
Cold compressed air foam fire control apparatus
6,095,251
Dual stage fire extinguisher
6,104,301
Hazard detection, warning, and response system
6,112,822
Method for delivering a fire suppression composition to a hazard
6,131,667
Manual and automatic fire extinguishing systems
6,138,766
Apparatus for preparing and disseminating novel fire extinguishing agents
6,146,544
Environmentally benign non-toxic fire flooding agents
6,164,382
Pyrotechnical device and process for extinguishing fires
6,173,790
Process and device for atomizing liquid extinguishing agents in stationary
extinguishing installations
6,182,768
Gas-liquid mixture as well as fire-extinguishing unit and method for the use
thereof
6,189,625
Liquid mist fire extinguisher
6,202,755
Fire extinguishing agent and method of preparation and use thereof
6,216,963
Device for regulating speed of deployment of sprinkler heads in preactive
sprinkler systems
6,241,164
Effervescent liquid fine mist apparatus and method
6,257,340
Fire extinguishing system using shock tube
6,267,788
Gas-Liquid mixture as well as fire-extinguishing unit and method for the use
thereof
6,314,754
Hypoxic fire prevention and fire suppression systems for computer rooms and
other human occupied facilities
6,317,053
Switch cabinet with a fire extinguishing system
6,318,473
Expansive fire extinguishing system
6,346,203
Method for the suppression of fire
6,352,648
Environmentally benign non-toxic fire flooding agents
6,367,560
Wet sprinkler system for cold environments
6,390,203
Fire suppression apparatus and method
6,394,188
Vehicular fire extinguishing device
6,401,487
Hypoxic fire prevention and fire suppression systems with breathable fire
extinguishing compositions for human occupied environments
6,401,830
Fire extinguishing agent and method
6,402,975
Environmentally benign non-toxic fire flooding agents
6,418,752
Hypoxic fire prevention and fire suppression systems and breathable fire
extinguishing compositions for human occupied environments
6,419,027
Fluoroalkylphosphorus compounds as fire and explosion protection agents
6,422,320
Enhanced agent misting extinguisher design for fire fighting
6,431,465
On-off valve and apparatus for performing work
6,478,979
Use of fluorinated ketones in fire extinguishing compositions
6,598,802
Effervescent liquid fine mist apparatus and method
6,601,653
Method and system for extinguishing fire in an enclosed space
6,637,518
Fire extinguishing apparatus
6,676,081
System for extinguishing and suppressing fire in an enclosed space in an aircraft
6,695,068
Textile and cordage net fire extinguisher system
6,702,033
Hybrid fire extinguisher
6,732,809
Apparatus for distributing granular material
6,739,400
Process and installation for fighting a fire in an aircraft compartment and aircraft
equipped with such an installation
6,745,847
Fire extinguishing spray nozzle
6,763,894
Clean agent fire suppression system and rapid atomizing nozzle in the same
6,796,382
Fire extinguishing ball
6,810,964
Pressurization system for fire extinguishers
6,840,331
Portable breathable fire extinguishing liquefied gas delivery system
6,849,194
Methods for preparing ethers, ether compositions, fluoroether fire extinguishing
systems, mixtures and methods
6,851,483
Fire suppression system and solid propellant aerosol generator for use therein
6,860,333
Thermally activated fire suppression system
6,868,915
Method for suppressing developing explosions
6,871,802
Self-modulating inert gas fire suppression system
6,889,775
Retrofitted non-Halon fire suppression system and method of retrofitting existing
Halon based systems
6,899,184
Fire suppression system and method for an interior area of an aircraft lavatory
waste container fire protection
6,902,009
Fire extinguisher with means for preventing freezing at outlet
6,907,940
Fast response fluid flow control valve/nozzle
6,935,433
Helium gas total flood fire suppression system
6,981,659
Liquid mist fire extinguisher
6,983,805
Fire blanket
6,988,558
Fire extinguishing method by gas and extinguishing device
7,004,261
Microemulsion mists as fire suppression agents
7,011,164
Engine disabler spray system
7,028,782
System and method for suppressing fires
7,048,068
Fire extinguishing system for large structures
7,066,274
Fire-suppression system for an aircraft
7,082,999
Pressurization system for fire extinguishers
7,083,742
Fluoroiodocarbon blends as CFC and halon replacements
7,089,862
Water pod
7,090,028
Fire suppression using water mist with ultrafine size droplets
7,121,353
Airborne vehicle for firefighting
7,121,354
Fire extinguishing device and method
7,128,163
Self servicing fire extinguisher with external operated internal mixing with wide
mouth and external CO.sub.2 chamber
H141
Fast dispensing fire extinguisher
RE29,614
Rupturing head for fire extinguishers | The present invention comprises apparatus and methods employing a gas produced from a tetrazine-based energetic material such as that known as “BTATz” containing 3;6-BtS(1H-1,2,3,4-Tetrazol-5-ylamino)1-,2,4,5-tetrazine 3;6-BtS(1H-1,2,3,4-Tetrazol-5-ylamino)1-,2,4,5-tetrazine or salts thereof. The tetrazinebased energetic material is ignited through the use of a percussion cap, a piezoelectric crystal or a battery-supplied electric spark or by encapsulating it in a container that is then exposed to a burning flame. The gas produced upon ignition is employed a propellant such as to inflate life rafts, life vests, emergency evacuation slides, tires, air bags and other inflatable devices. The gas produced upon ignition is alternatively employed to power an engine and many other applications such as a fire suppressant. | 2 |
BACKGROUND OF THE INVENTION
[0001] This application claims benefit of pending Provisional Application 60/302,130 filed Jun. 29, 2001.
[0002] Solid hand held skin cleaning compositions have been marketed for decades. Liquid skin cleansing compositions have made some inroads into sales of solid compositions, particularly in certain geographical areas. However, solid skin cleansing compositions, particularly bars, remain a preferred vehicle for skin cleansing worldwide.
[0003] In order to maintain and enhance continued sales of solid skin cleansing compositions, various improvements have been made such as use of mildness enhancing agents such as certain surfactants, free fatty acids, and the like as well as skin benefit agents and conditioning agents such as cationic polymers and oily material such as mineral oil and petrolatum. Efforts to make these bars more attractive such as translucent and transparent bars are also available. Particles such as mica, bismuth oxychloride, kaolin and the like have also been added to these compositions in order to enhance their attractiveness.
[0004] In an attempt to create striations in soap, U.S. Pat. No. 4,879,063 discloses a method for preparing a striated translucent bar utilizing a perforated plate situated next to and downstream from the spider, the part in the extruder which holds the screw in place. U.S. Pat. Nos. 5,196,131 and 5,242,614 disclose a soap having the alleged appearance of a polished wood grain prepared using a perforated plate situated next to and downstream from the spider and producing striations in the bar with an iron oxide coated micaceous pearlescent pigment which is oriented generally unidirectional. As aforestated, the perforated plate is next to the spider holding down the end of the screw. Translucent soap bars are clearly preferred over opaque because the resulting wood grain appearance is brighter and sharper. However, it is believed that in no situations are there clear, uniform and relatively thick striations, which can be observed by the human eye.
[0005] We have discovered a method of placing sharp, distinctive striations into a cleansing bar using substantially lower levels of platelet reflecting material than utilized previously and obtaining an even sharper more better defined striation than obtained previously. The benefits occur in opaque as well as translucent bars. The process utilizes a perforated barrier located a substantial displacement from the spider of the extruder. Such placement of the perforated barrier allows the striations to be clear and sharply defined.
SUMMARY OF THE INVENTION
[0006] In accordance with the invention there is a process for preparing a cleansing bar having well defined platelet striations therein which comprises extruding a cleansing bar having platelets therein using an extruder having a perforated barrier across the cross section of the extruder, the barrier a sufficient distance from the spider so that well-defined platelet striations are observed in the finished bar with the human eye. Generally the perforated barrier is located at least about 60% preferably at least about 70% from the spider, as measured from the spider to the extruder cone outlet. Generally, a standard extruder cone length from spider to cone outlet is about 483 mm to about 560 mm.
[0007] Further, in accordance with the invention, there is a process for preparing a cleansing bar having well defined platelet striations therein which comprises extruding a cleansing bar composition having platelets therein through an extruder which comprises having disposed within the extruder cone a smaller cone and having a perforated barrier across the cross section of the extruder cone or the smaller cone said perforated barrier substantially displaced downstream from the extruder spider, at least about 60% of the distance from the spider, as measured from the spider to the extruder cone outlet so as to prepare a cleansing bar having well defined striations therein.
[0008] A further aspect of the invention is an extruder suitable for extruding cleansing bar compositions having attached to the end of its cone a second cone having disposed in the extruder cone or the attached cone a perforated barrier across the cross section of the extruder cone or the smaller attached cone, said perforated barrier in each situation substantially displaced downstream from the extruder spider, at least about 60% of the distance from the spider as measured from the spider to the extruder cone outlet so as to prepare a cleansing bar having well defined striations therein.
[0009] An additional aspect of the invention is a cleansing bar having disposed therein and clearly defined to the human eye striations of a platelet.
[0010] Still further, an additional aspect of the invention is an extruder suitable for extruding a cleansing bar composition; said extruder having a perforated barrier disposed therein across the cross section of the extruder, the said barrier being located downstream from the spider holding the screw and the barrier being at least 60% of the distance between the spider and the extruder cone outlet.
DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a view of a cone fitting within the cone of an extruder wherein a perforated barrier is present across the full cross section.
[0012] [0012]FIG. 2 is a close up of the perforated barrier of FIG. 1 showing the alignment and passage through the perforations of a cleansing composition having platelets.
[0013] [0013]FIG. 3 is an example of a perforated barrier having a series of 4.75 mm diameter holes.
[0014] [0014]FIG. 4 is a view of an extruder cone with a perforated barrier inside the extruder at an appropriate distance away from the spider.
[0015] [0015]FIG. 5 is an extruder with a cone attached to the extruder cone outlet and the perforated barrier is located at the junction point of the attached cone and extrusion cone outlet.
[0016] [0016]FIG. 6 is a view of a cone with increased taper fitting within the extruder cone and a perforated barrier.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The aesthetics of a cleansing bar are extremely important to its acceptance and continual purchase by consumers. A bar's shape, color and fragrance are among the features, which appeal to the senses of touch, sight and smell. However, other aspects of visual appeal can also be accentuated. Striations are lines of a solid platelet material in a bar. When present, these can present an additional attractive feature, which is appealing to the consumer and provides an additional point of differentiation over competitor's offerings. However, obtaining well-defined striations is not easily done and has not been accomplished through known processes. Following the prior art teachings previously mentioned does not bring about a well-defined, visually attractive bar under commercial extrusion conditions, particularly in an opaque bar. The platelet material can barely be seen by the naked eye and there are no well-defined lines. In using this invention, the particles are readily observed by the naked eye in well-defined lines. These lines are not just on the surface but can be maintained in at least essentially the same definition throughout the bar, each separate use or series of bar uses revealing a new layer(s) of soap with striations. This can be accomplished with a minimum of platelets, substantially less than used in the prior art.
[0018] The type of particle, which can be added to the cleansing composition for striation purposes, is any type of platelet, which has an aspect ratio that allows it to be aligned under pressure. Generally, these are pearlescent platelets on an inorganic base, such as mica, bismuth oxychloride, kaolin, and the like. The mica is the preferred platelet and can be coated with titanium dioxide to be even more light reflective. This is available from Engelhard with the preferred material being Timica Extra Bright 1500. Englehard information says the Timica particle size range is about 8 to 48 microns and an average thickness of about 0.62 microns. Other coatings include iron oxide on the micaceous pearlescent pigment. The aspect ratio of the platelet is sufficient to easily align the platelet when forced through the perforations in the barrier while under pressure. The quantity of platelets, which can be used, is quite low, particularly with respect to the quantities noted in the above-noted patents and specifically with respect to opaque soaps. The quantity of platelet used covers at least that quantity which provides a better visually defined striation in a bar than produced with the same quantity of platelet using the process of the above noted patents. Generally the platelet is a minimum of about 0.1 wt % of the composition, or about 0.15, 0.2 or 0.25 wt % of the composition. A maximum amount is dependent upon the number, width, and depth of striations one wishes to have. Generally no more than about 3 wt % is employed. Less than about 2 or 1 wt % also can be employed.
[0019] The perforated barrier is inserted into the cone and extends the full cross section of the cone. The standard extruder generally is sufficient to bring about desired striations.
[0020] The closer the perforated barrier to the exit point of the cone, the more well defined the striation. The perforated barrier is located sufficiently distant from the cone exit point so as to have a complete cross-section of bar composition leaving the cone exit. The composition is desirably not in separate strands. The size and shape of the cone exit cross-section approximates the size and shape of the billet, which is further processed into the soap bar. A round cross section is preferred. Preferably, the cone exit is the same size and shape as the billet.
[0021] Various embodiments of the invention can be employed. A preferred embodiment is a cone within the extruder cone. This cone can be fitted in at the exit point. This additional cone providing a “cone within a cone” apparatus can be readily inserted and removed thereby increasing flexible use of the extruder. The inner diameter of the cone can be essentially the same taper as the extruder or it can be increased. The increased taper of the inner cone reduces the amount of dead spots thereby reducing eddies. Therefore an even more defined striation will occur. The perforated barrier is placed at least the aforestated minimum distance from the spider but it is preferred to place the barrier at the entrance to the inner cone or within the inner cone as long as the composition exits the cone exit as a single mass.
[0022] A more preferred embodiment is where an additional cone is attached to the outlet area of the extruder cone. This cone can have the same taper as the extruder cone or can have an increased taper. The perforated barrier can be located inside the extruder cone, at the juncture point of the attached cone or within the attached cone. The exit point of the attached cone approximates the size and the shape of the billet. A round billet is preferred. The composition should exit the attached cone outlet as a single mass. The use of an attached cone is more advantageous since it more easily attaches or removes in comparison to the inner cone.
[0023] The cone within the extruder cone and the attached cone are substantially shorter than the extruder cone. For example, it is generally no longer than about 40% of the distance between the spider and the cone extruder outlet. It is generally desirable to have the cone within the cone and the attached cone no longer than about 15 to 20% of the distance between the extruder spider and the extruder cone outlet. They can be a shorter length if desired.
[0024] The bar composition generally has at least some soap in it, preferably from about 5 to about 95 wt. % of the composition. The processing parameters are conventional as used in the preparation of any soap bar. The bars can be opaque or translucent. Opaque bars are preferred.
[0025] The barrier is made up of any material, which can withstand the temperatures and pressures of the processing. Steel can be used.
[0026] The cross sections of the perforations usually circular are in the range of about 0.5 to about 10 mm, desirably about 1, 1.5 or 2.5 as minimums, with a maximum up to about 7.5 mm in diameter. The number of perforations, the placement of the perforations in the barrier in specific patterns and the spacing of the perforation influence the thickness of the striation in the final cleansing bar. The striations can be essentially only on the surface of the bar but can also be any distance through the depth of the bar and including completely throughout the depth of the bar.
[0027] With respect to the Figures, FIG. 1 shows an extruder cone, 1 , having a spider, 3 , and disposed within the extruder cone a shorter cone, 6 , and a perforated barrier, 9 , at the juncture of the shorter cone.
[0028] [0028]FIG. 2 is a close-up perspective of the perforated barrier showing the soap composition with platelets passing through the perforations.
[0029] [0029]FIG. 3 provides a view of a perforated barrier, 11 , with perforations, 14 .
[0030] [0030]FIG. 4 shows an extruder cone, 17 , with a spider, 20 , a perforated barrier, 23 , and-the extruder cone outlet, 26 .
[0031] [0031]FIG. 5 shows an extruder cone, 29 , with a spider, 32 , and a cone, 35 , attached to the extruder cone at the extruder cone outlet, 38 , and a perforated barrier, 41 .
[0032] [0032]FIG. 6 shows an extruder cone, 44 , a spider, 47 , a cone within the extruder cone showing an increased taper, 50 , and a perforated barrier, 53 .
[0033] Below are specific examples of the invention, 1 and 2 . A comparative example is 3 .
EXAMPLE 1
[0034] The 80/20 tallow/coconut fatty acid blend sodium soap pellets were used. These soap pellets contained 18-19% moisture, 5% glycerin, 1% superfat. The glycerin was added to the neat soap, and the superfat was generated via in-situ with citric acid with the neat soap at the crutcher. These soap pellets were amalgamated with fragrance and 20% titanium dioxide coated mica slurry which consisted of 0.2% mica with 0.4% glycerin and 0.4% water (by weight on the finished bar), and colorant. After the amalgamation, the soap mixture was refined in a 10-inch duplex refiner with 0.6 mm and 0.4 mm screen were installed in the top and bottom stage respectively. The refined soap mixture was then passed through the 10-inch duplex vacuum plodder in which the perforated barrier and the attached cone were attached at the end of the original extrusion cone that is, the extrusion cone outlet. The perforated barrier has 4 mm diameter holes, 47 holes in the largest perimeter holes and total of 237 holes. The attached cone has an outlet diameter of 42 mm, a length of 80 mm and the cone angle (from the cone base) of 64.5 degrees. The soap mass was extruded through the perforated barrier and compacted into billet form by the extended cone. The billet was then cut and pressed. The very visible, uniform, orderly and consistent striation pattern was obtained on the bars.
EXAMPLE 2
[0035] The same equipment set-up as in Example 1 was used. The 80/20 tallow/coconut fatty acid blend sodium soap pellets were used. The pellets contained of 17-18% moisture, petrolatum, 1% glycerin, and 1% superfat, which generated by in-situ of phosphoric acid with neat soap at the crutcher. These soap pellets were amalgamated with fragrance, polyquat, dimethicone and 20% titanium dioxide coated mica slurry which consisted of 0.2% mica with 0.4% glycerin and 0.4% water (by weight on the finished bar), and colorant. This soap mixture was processed as in Example 1. The very visible (however, lesser than 5% glycerin soap), uniform, orderly and consistent striation pattern was obtained on the bars.
EXAMPLE 3
[0036] A study was conducted to compare this invention with prior art (1) the Wood-Rethwill et al, U.S. Pat. No. 4,879,063. Two trials were conducted on the same basic equipment, formula and process as in Example 1. The first was on a compact plate with 13 mm ID holes and a worm opening-to-compact plate ratio of 2.1. The second was a compact plate with 10 mm ID holes and a worm opening-to-compact plate opening ratio of 2.4. The soap was extruded on a standard cone with 42 mm diameter extrusion plate. A very, very fine, non-uniform and inconsistent striation pattern and a “milky” appearance resulted.
[0037] It should be noted that the use of higher quantities of glycerin, i.e. about 3, 4, or 5 wt % glycerine brings about sharper, more visible striations than those in lower content glycerine bars. Generally, no more than about 6, 7, or 8 wt % glycerine need be used. | A process for preparing a cleansing bar having well defined platelet striations therein which comprises extruding a cleansing bar having platelets therein using an extruder having a perforated barrier across the cross section of the extruder, the barrier a sufficient distance from the spider so that well-defined platelet striations are observed in the finished bar with the human eye. Generally the perforated barrier is located at least about 60% preferably at least about 70% from the spider, as measured from the spider to the extruder cone outlet. Generally, a standard extruder cone length from spider to cone outlet is about 483 mm to about 560 mm. | 1 |
BACKGROUND OF THE INVENTION
This invention relates generally to a performance enhancing and force absorbing quadruple composite dental appliance for use by athletes, and more particularly to such an adjustable, customizable appliance that spaces apart the teeth to absorb shock and clenching stress, to space apart the anterior teeth of the lower and upper jaws to facilitate breathing and speech, to lessen condyle pressure, force and impact upon the cartilage and temporomandibular joints, the arteries and the nerves, and to further increase body muscular strength and endurance.
Almost all athletes, such as body builders, weight lifters, baseball batters, golfers, football players, hockey players and bowlers, clench their teeth during exertion which results in hundreds of pounds of compressed force exerted from the lower jaw onto the upper jaw.
This clenching force is unevenly transmitted through the jaw structure into the connective tissues and muscles of the lower jaw and further into the neck and back. This can result in headaches, muscle spasms, damage to teeth, injury to the temporomandibular joint, and pain in the jaw. Furthermore, clenching the teeth makes breathing more difficult during physical exercise and endurance when breathing is most important.
The natural inclination to clench the jaw during physical exertion is impossible to avoid. One theory is that this is an ancient reflex designed to protect the caveman's jaw from displacement or fracture. An injury to ancient man's jaw meant almost certain death from starvation. Man still instinctively clenches his teeth to lock his jaw into a safe position during aggression or physical activity to protect his jaw. But when the teeth are clenched, the body puts an upper limit on one's strength so that one can't overclench and damage one's teeth and jaw structures.
There are over 60 million overweight Americans today. Spending in the diet aid category equals $1.06 billion annually. Research shows that use of a dental appliance to prevent damage to the teeth during clenching helps to increase the productivity of an aerobic workout by increasing endurance and muscle activity and therefore calorie burn.
More than 80% of the population has some measure of improper jaw alignment, causing painful chewing, tooth grinding, migraine headaches, stress or several of these problems at once. The temporomandibular (TM) artery runs directly through the TM joint. This main artery carries oxygenated blood to the arteries in the face and head. When the TM joint is properly balanced, blood flows freely to these areas, which is believed to lessen the incidence of headache and stress. When the TM joint is out of balance or improperly aligned, undue stress is placed on this vital artery and the corresponding muscle groups.
Each year, reports the Journal of the American Dental Association, dentists make approximately 3.6 million anti-bruxing devices for their tooth grinding patients. Sizing and fitting in the past has required dental assistance. At an average cost of $275 (but sometimes much higher), this equates to a one billion dollar market. Nocturnal tooth grinding is a major pain—powerful enough to crack a walnut at 250 pounds per square inch, the pressure is ten times the force registered during normal chewing. Bruxing causes the teeth to wear down at odd angles, affecting the shape of the face, causing migraine headaches and muscle soreness and aggravating TMJ disorders.
The market for over-the-counter analgesics in the U.S. was $2.91 billion in 1996. An estimated 18 million people suffer from migraine headaches, another 6 million form back and neck pain. While almost 3 million Americans are treated annually by pain clinics, many more remain in need due to inadequate insurance or denial of benefits for such treatment. Studies have shown that increasing the blood flow to the arteries of the face can help reduce headache pain. Repositioning the jaw by a dental appliance to alleviate stress and pain acts as a drug-free remedy to millions of stress and headache sufferers by temporarily restoring blood flow to the face and head.
It is well known that the birthing process creates a tremendous amount of physiological and psychological stress upon the mother. In fact, pregnant women go through weeks, if not months, of physical exercise to prepare them for the exertions necessary during the birth of their child. The actual birthing process is very analogous to athletes as women about to give birth may very well clench their teeth during the exertion of labor.
Rehabilitation relative to heart attacks, operations and injuries also require exertion and can be facilitated by an increased blood flow to the brain and return back to good conditioning with exercise.
Snoring occurs when the mouth is open and the tongue moves back into the throat. This causes the airway passage to narrow which increases the likelihood of snoring. It is known that moving the condyle of the lower jaw forward in a way will increase the airway and assist in the elimination of snoring.
It is believed that consciousness and the ability to focus is increased with an object in the mouth. This causes one to salivate, focus and be more awakened with improved concentration, hand eye coordination, and even thought process which otherwise would be non-voluntary reactions.
U.S. Pat. No. 5,584,687 discloses a singular material performance enhancing dental appliance. U.S. Pat. Nos. 5,865,619 (the '619 patent) and U.S. Pat. No. 6,012,919 (the '919 patent) disclose a triple composite performance enhancing dental appliance. Applicant has found that the embodiments of the '687 patent, the '619 patent and the '919 patent have several deficiencies that Applicant has corrected in the instant invention.
Most importantly, many problems exist with prior dental appliances having posterior pads and a connective arch. Labial or buccal walls did not accept wide teeth, were bulky and had sharp edges. Arches medially located across the palate caused gagging and speech impediments, as well as fitting problems. Weak arches cause the appliances to collapse and permit the pads to touch and stick together upon removal from hot water. Thus, fitting of such appliances has always been a problem. Wide posterior teeth and deep and shallow palates required multiple sizes which were difficult for the consumer to choose from, let alone fit. Delamination and chewing destruction caused short life.
The present invention solves the prior art problems and discloses an appliance suitable for all the above needs and uses, plus many more, which will be appreciated with a review of the specification, claims and figures.
SUMMARY OF THE INVENTION
A performance enhancing and force absorbing dental appliance adapted to lie within the mouth of an athlete consists of occlusal posterior pads made of quadruple composite material comprising four layers of distinct materials and a connective arch. The first bottom layer traction pad is of a durable, resilient elastomeric gripping material. The second layer is of non-softenable, flexible, shape maintaining framework material that is expandable and contractible. The third layer is of a hard, very durable wedge-shaped bite plate material. The fourth arch layer is of a softenable material, moldable to fit and grip the posterior teeth and anterior palate. The fourth material substantially encloses the appliance. The four materials are physically interlocked. An anti-microbial agent may be added to the materials.
A principal object and advantage of the present invention is that the appliance protects the teeth, jaws, gums, connective tissues, back, head and muscles from teeth clenching forces typically exerted during athletic activity and birthing.
Another object and advantage of the present invention is that it facilitates breathing and speech during strenuous physical activity such as in power lifting or bodybuilding.
Another object and advantage of the present invention is that the appliance places the lower jaw in the power position moving the condyle downwardly and forwardly away from the nerves and arteries within the fossae or socket to raise body muscular strength, greater endurance and improved performance by the appliance user.
Another object and advantage of the present invention is that the appliance is customizable to fit the width and configurations of the upper posterior teeth and the palate structure of any user. Teeth width, spacing from one side of the mouth to the other side of the mouth and palate height varies substantially from person to person.
Another object and advantage of the present invention is that it allows the wearer to increase effort and calorie burn during a workout by preventing the clenching reflex from limiting bodily strength and endurance.
Another object and advantage of the present invention is that it prevents grinding of the teeth (bruxing).
Another object and advantage of the present invention is that helps to alleviate pain such as migraine headache by properly positioning the lower jaw and increasing the blood flow through the temporomandibular artery and associated circulatory and nerve systems.
Another object and advantage of the present invention is that allows a woman to increase the force with which she bears down during labor contractions, without harming the teeth and associated oral structures.
Another object and advantage of the present invention is that it assists in the rehabilitation process of recovering from injury or heart attacks by increasing the flow of blood and oxygen to the brain.
Another object and advantage of the present invention is that it increases consciousness and is believed to have a systemic action that can alter non-voluntary reactions to external stimuli to make the appliance wearer more conscientious, focused, awake and ready.
Another object and advantage is that the present invention reduces snoring by moving the condyle forward and further opening up the airway passage.
Another object and advantage of the present invention is that it has a tough, rubbery, elastomeric, unpenetrable bottom layer or traction pad engaging and gripping the lower teeth which prevents the appliance from being chewed through and assures long life to the appliance.
Another object and advantage of the present invention is that it has a second layer of a non-softenable, flexible material. This material is extended in a serpentine bridge and cross-cantilever connectors that supports the appliance after heating to maintain shape and guides the upper teeth during the fitting process.
Another object and advantage of the present invention is that it has a third layer of a hard, very durable material that acts as a bite plate, reverse wedge or fulcrum that cannot be penetrated by the teeth, giving the appliance a longer life cycle.
Another object and advantage of the present invention is that the occlusal pads and the adjustable arch are preferably made of a fourth layer of a softenable material which will permit the user to refit the appliance should the appliance not originally fit properly.
Another object and advantage of the present invention is that the fourth layer has been extended over the second and third layers and provides for the formation of a smooth, labial wall, greatly increasing comfort and avoiding sharp edges. This allows the user to manipulate the softenable material and custom fabricate a labial wall that will accormnodate any tooth width and palate depth or height.
Another object and advantage of the present invention is that eliminating a rigid labial wall also decreases the amount of material between the teeth and cheek, making the appliance more comfortable and less intrusive and cumbersome. Less material also makes the appliance less visible and bulky in the wearer's mouth. Furthermore, the absence of a rigid labial wall results in less pressure and squeezing on the teeth, improving comfort and fit.
Another object and advantage is that the arch is dramatically canted forwardly toward the anterior teeth of the upper jaw, greatly increasing comfort and reducing gagging and speech impediment.
Another object and advantage of the present invention is that an anti-microbial and/or anti-bacterial ingredient keeps the appliance free of germs or odor causing microbials and bacteria during non-use and storage.
Another object and advantage of the present invention is that the mechanically interlocked four materials will not separate with use or chewing by the user which is common with athletes. This secure interlock of the materials is further supported by heat, pressure and ultimate compatible chemical bonding.
Another object and advantage is that the wearer of the appliance experiences decreased heart rate and quicker recovery during aerobic exercise and activity.
Another object and advantage is that wearing the present invention increases dopamine concentration for increased motor activity.
Another object and advantage is that the appliance is ideal for health and wellness, birthing, industrial, dental, bruxing, exercise, awareness and athletic competition and protection.
Another object and advantage is that the Belvedere bridge, Cross cantilever connectors and occlusal pad plates of the non-softening but flexible framework maintains appliance shape during heating and fitting and permits expansion and contraction to fit any teeth and palate.
Other objects and advantages will become obvious with the reading of the following specification and appended claims with a review of the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a maxillary mandibular buccal or partial side elevational view of the jaws and temporomandibular joint of the user of the dental appliance of the present invention;
FIG. 1A is an enlarged view of the temporomandibular joint portion of FIG. 1;
FIG. 2 is similar to FIG. 1, but shows the dental appliance of the present invention in place;
FIG. 3 is an exploded perspective view of the dental appliance of the present invention;
FIG. 4 is a bottom plan view partially broken away of the dental appliance of the present invention;
FIG. 5 is a side elevational view with the fourth arch material in phantom outline of the dental appliance of the present invention;
FIG. 6 is a bottom plan view of the dental appliance of the present invention in place in the mouth;
FIG. 7 is a bottom perspective view of the dental appliance of the present invention in place in the mouth;
FIG. 8 is a cross-section of the dental appliance of the present invention taken at approximately the lines 8 — 8 of FIG. 4;
FIG. 9 is a cross-sectional view taken along lines 9 — 9 of FIG. 4 partially broken away at the arch;
FIG. 9 a is an enlarged, detailed and broken away view of the interlocking projections 77 ;
FIG. 10 is a cross-sectional view taken along lines 10 — 10 of FIG. 4 partially broken away showing the interlocking projections;
FIG. 11 is a view similar to FIG. 10 with the posterior teeth fitted to the appliance;
FIG. 12 is a bottom plan view partially broken away showing another traction pad configuration;
FIG. 13 is a view similar to FIG. 12 showing another traction pad configuration; and
FIG. 14 is a perspective view collectively showing three different form-fitted appliances for different people made from the same invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
To understand the structural features and benefits of the dental appliance 70 of the present invention, some anatomy will first be described. Referring to FIGS. 1 and 1A, the user or athlete has a mouth 10 generally comprised of a rigid upper jaw 12 and a moveable lower jaw 42 which are movably connected at the temporomandibular joint (TMJ) 32 and 50 .
More specifically, the rigid upper jaw 12 has gum tissue 14 within mouth 10 . Gum tissue 14 , as well as the bone thereunder, supports anterior teeth (incisors and canines) 18 which have incisal or biting surfaces 19 . The gum tissues 14 and the bone thereunder also support posterior teeth (molars and bicuspids) 22 which have cusps or biting surfaces 26 .
Referring to one side of the human head, the temporal bone 28 is located upwardly and rearwardly of the upper jaw 12 and is in the range of {fraction (1/16)} to {fraction (1/32)} inch thick. The articular eminence 30 forms the beginning of the fossae 32 or the socket of the temporomandibular joint 32 and 50 .
Rearwardly and posteriorly to the articular eminence 30 is located cartilage 34 . Through the temporomandibular joint 32 and 50 pass the auriculo-temporalis nerve 36 and the supra-temporo artery 38 . Posteriorly to this structure is located the inner ear 40 . Within the mouth is located tongue 39 and the roof or hard palate 41 , which terminates rearwardly into the soft palate and forwardly into the anterior palate or ruggae 43 . The ruggae 43 has a ribbed surface which is identifiable by fingers or tongue 39 .
The movable jaw or mandible 42 supports a bone covered by gum tissue 44 which further supports anterior teeth (incisors and canines) 46 with incisal or biting surfaces 47 and posterior teeth (molars and bicuspids) 48 with occlusal biting surfaces 49 . The condyle 50 of the lower jaw 42 forms the ball of the temporomandibular joint 32 and 50 . The anatomical structure is the same for both sides of the head.
Repeated impacts, collisions, blows, stress or forces exerted on the movable lower jaw 42 result in excessive wearing forces upon the condyle 50 and the cartilage, meniscus, or disc 34 —typically resulting in bone deterioration on the head of the condyle or slippage and compressive damage of the cartilage 34 . Thereafter, the lower jaw 42 may be subject to irregular movement, pain, loss of comfortable range of movement and clicking of the joint 32 and 50 .
The auriculo-temporalis nerve 36 relates to both sensory and motor activity of the body. Any impingement or pinching of this nerve 36 can result in health problems as previously mentioned. The supra-temporal artery 38 is important in that it provides blood circulation to portions of the head. Impingement, pinching, rupture or blockage of this artery 38 will result in possible loss of consciousness and reduced physical ability and endurance due to the restriction of blood flow to portions of the brain. Thus, it is extremely important to assure that the condyle 50 does not impinge upon the auriculo-temporalis nerve 36 or the supra-temporal artery 38 .
It is also important to note that the temporal bone 28 is not too thick in the area of the glenoid fossae. Medical science has known that a sharp shock, stress, or concussive force applied to the lower jaw 42 possibly could result in the condyle 50 protruding through the glenoid fossae of the temporal bone 28 , thereby causing death. There is a suture line (growth and development seam) in the glenoid fossae, resulting in a possible weakness in the fossae in many humans. This incident rarely, but sometimes, occurs with respect to boxing athletes.
The dental appliance of the present invention is shown in the Figures as reference numeral 70 .
The dental appliance 70 has a pair of quadruple-composite occlusal pads 72 , comprised of four layers of distinct materials 74 , 80 , 90 and 100 . Each pad may or may not have a preformed moldable labial or buccal wall 82 (present in FIGS. 3, 8 and 10 ). The absence of a rigid labial wall assures comfortable fitting for any width of mouth and posterior teeth 22 .
The materials may have antimicrobial or antibacterial agents added. Swiss made Triclosan® by Siba Giegy or Microban® by Microban of Huntersville, N.C. 20808 are acceptable agents.
The traction pads or first layer 74 contacts and grips the occlusal biting surfaces 49 of the posterior teeth 48 of the lower jaw and is composed of a durable, resilient material which deforms somewhat when the jaws are closed and cushions the teeth 48 of the lower jaw.
The durable, resilient material of the first layer 74 comprises a mixture of a styrene block copolymer and ethylene vinyl acetate (EVA). A suitable styrene block copolymer is available as DYNAFLEX® part number G2782 from GLS Corporation, Thermoplastic Elastomers Division, 833 Ridgeview Dr., McHenry, Ill. 60050. EVA is available from a number of sources, such as the ELVAX® resins from Dupont Packaging and Industrial Polymers, 1007 Market Street, Wilmington, Del. 19898. It is desirable that the durable, resilient material have a Shore “A” hardness of 82 , which is very durable, yet rubbery.
In a second embodiment, the durable, resilient material of the first layer 74 comprises a mixture of a styrene block copolymer as described above and a polyolefin elastomer. Preferably, the polyolefin elastomer is a copolymer of ethylene and octene-1. A suitable copolymer is available as ENGAGE® from Dupont Canada, Inc., P.O. Box 2200, Streetsville, Mississauga, Ontario L5M 2H3.
In a third embodiment, the durable, resilient material of the first layer 74 comprises a mixture of a thermoplastic rubber and a polyolefin elastomer as described above. Suitable thermoplastic rubbers are Santoprene® from Advanced Elastomer Systems, L.P., 388 South Main Street, Akron, Ohio 44311 and Kraton® thermoplastic rubber from the Shell Oil Company, Houston, Tex. Kraton® is composed of a styrene-ethylene/butylenes-styrene block copolymer and other ingredients. The composition of Santoprene® is a trade secret.
The second layer 80 is composed of a non-softenable, flexible material that rigidly holds its shape in hot water and will not melt during molding of succeeding materials 90 and 100 . Polypropylene (co-polymer) is suitable. Polypropylene part number AP6112-HS from Huntsman Corporation, Chesapeake, Va. 23320, has a melting point of 386° F. The second layer includes a connected framework 80 including the pad plate 82 , cross-cantilevered connectors 86 and the serpentine Belvedere bridge 88 .
High-density polyethylene is a typical material. A suitable high-density polyethylene is HD-6706 ESCORENE® Injection Molding Resin from ExxonMobil Chemical Company, P.O. Box 3272, Houston, Tex. 77253-3272. This material is a linear polyethylene or ethylene-olefin copolymer. The third layer must be hard enough so that it cannot be penetrated by the teeth under maximum biting pressure and thereby forms a bite plate 90 .
The fourth arch layer 100 comprises a softenable material contacting the teeth of the upper jaw and encapsulating the framework 80 , bite plate 90 and partially the traction pads 74 . Typically, the material is softenable by heat.
In one embodiment, the softenable material of the fourth layer 80 comprises a mixture of polycaprolactone. A suitable polycaprolactone is Tone™ Polymer P-767 from Union Carbide Corporation, 39 Old Ridgebury Road, Danbury, Conn. 06817-0001.
In a second embodiment, the softenable material of the fourth layer 100 comprises a mixture of polycaprolactone and ethylene vinyl acetate (EVA) such as ELVAX®.
In a third embodiment, the softenable material of the fourth layer 100 comprises ethylene vinyl acetate (EVA) alone, such as ELVAX®.
In a fourth embodiment, the softenable material of the fourth layer 100 comprises a mixture of polycaprolactone and a polyolefin elastomer. Preferably, the polyolefin elastomer is a copolymer of ethylene and octene-1. A suitable copolymer is available as ENGAGE® from Dupont Canada, Inc., P.O. Box 2200, Streetsville, Mississauga, Ontario L5M 2H3.
As can be seen best in FIG. 8, the softenable material of the fourth layer 100 extends downwardly over encapsulating the second and third layers, forming the labial wall 82 of the appliance and leaving only the tread 76 of traction pads 74 exposed.
The four layers are bonded together. In addition, the bite plate 90 and framework 80 are further interlocked with the first layer 74 by projections 77 in the first layer mating with apertures 94 in the bite plate.
The dental appliance 70 further comprises a continuous vertical arch 100 open anteriorly and posteriorly, extending from the fourth layer 100 of the occlusal pads 72 and constructed from the softenable material of the fourth layer 100 . As best seen in FIGS. 2 and 5, the arch 100 is canted forwardly from the occlusal pads 72 toward the anterior teeth 18 of the upper jaw 12 , so that the arch 100 contacts the upper jaw 12 adjacent the gum tissue 14 of the anterior teeth 18 at the ruggae or anterior palate 43 . The arch 100 is adapted to expand and contract to be molded to the anterior palate 43 and adapted to lie along the anterior palate out of the way of the tongue and extending directly across to and connecting the pads 72 together within the mouth and out of the way of the tongue to maintain the positions of the occlusal pads within the mouth and to prevent loss of the pads such as by swallowing. The arch fourth material 100 forms tooth channel 102 with central raised portion 104 , labial wall 106 and lingual wall 108 .
A tunnel 110 (FIG. 8) extends beneath the arch 86 and is defined by the arch 100 and the lingual walls 108 . The tunnel 110 is open anteriorly and posteriorly to allow unobstructed movement of the tongue 39 anteriorly and posteriorly.
The framework 80 of the dental appliance 70 further preferably comprises a serpentine Belevedere bridge 88 embedded within the softenable material of the arch 100 . The bridge 88 is expandable and contractible, thereby following the arch 100 as it is molded to the palate. Also, the bridge 88 does not soften as much as the arch 100 during heating, and therefore prevents the arch 100 from collapsing during the fitting process described below. The bridge 88 is preferably comprised of the non-softening material of the second layer 80 and is continuous with the Cross-cantilever connectors 86 which is connected to the occlusal pad plates 82 . Thus, the appliance does not go limp upon heating as its shape is supported by the bridge 88 , connectors 86 and pad plate 82 .
To create the dental appliance 70 of the present invention, the second layer framework 80 is formed, including the occlusal pad plate 82 with openings 84 therethrough. Cross-cantilevered connectors 86 connect along the length of the pad plate 82 and join up with the serpentine Belevedere bridge 88 to give the appliance 70 rigidity while yet permitting the appliance to expand and contract laterally and upwardly as will be appreciated (see arrows in FIG. 4 ). Next, the third layer bite plate or reverse wedge 90 is formed having bosses or raised portions 92 on their underside along with apertures 94 extending therethrough. Next, the bite plate 90 has its bosses indexed into the openings 84 of the framework pad plate 82 . The first layer traction pads are next formed with their locking knobs 76 extending up through openings 84 and apertures 94 locking the first 74 , second 80 , and third 90 layers together. Lastly, the fourth layer arch 100 is formed around the entire dental appliance 70 , excepting the tread portion 76 of the traction pad 74 . Tooth channel 102 was formed along with central raised portion 104 , labial or buckle wall 106 and lingual or inner wall 108 . Tunnel 110 is thus formed thereunder.
To prevent the traction pads 74 from shearing away from the bite plate 90 , the projection 77 further comprises a curved portion 78 and thereby capturing and interlocking pads 74 , framework 80 and bite plate 90 . Preferably, the curved portion 78 is convex relative to the central axis X 1 , as shown in the Figures. This construction deters shearing.
To further lock the traction pad 74 to the framework 80 , a lip or retaining lid 79 integral with the traction pad 74 wraps over the pad plate 82 of the framework 80 like the lid of a bucket and thereby holds the appliance together as shown in FIGS. 9-11.
To fit the dental appliance 70 to the user's mouth, the dental appliance 70 is placed in hot water at about 212° Fahrenheit (i.e., water that has been brought to a boil and then taken off the heat) for about 15 seconds. The dental appliance is then removed from the hot water, and it will be very soft, but the framework 80 will hold the appliance's general shape. Excess water is allowed to drain off the appliance 70 by holding it with a spoon so that the walls 108 of the appliance 70 do not touch (they will stick to each other if brought together and will be very difficult to separate).
Next, the wearer carefully places the appliance 70 in the mouth so that the anterior portion of the appliance 70 touches or covers the eye teeth (the third set of teeth from the front) and extends backwards toward the molars, bites down firmly on the appliance 70 and pushes the tongue against the roof of the mouth. The Cross-cantilevered connectors guide the upper molars 22 into position on pads 72 . With a strong sucking motion, the wearer draws out all air and water from the appliance 70 . The projections or knobs 77 will index to the cusps of the molars 22 .
With a thumb, the wearer presses the appliance 70 tight against the roof of the mouth and then uses his hands and fingers to press the outside of the cheeks against the appliance 70 , as the fourth layer of raised portion 104 oozes inwardly and outwardly to form the lingual and buccal walls 108 and 106 respectively. Because there is no rigid lingual wall, the appliance 70 will fit any width of molar 22 or mouth.
The wearer retains the appliance 70 in the mouth for at least one minute and, with the appliance 70 still in the mouth, takes a drink of cold water. Next, the wearer removes the appliance 70 from the mouth and places it in cold water for about 30 seconds.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof; therefore, the illustrated embodiment should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention. | A performance enhancing and force absorbing dental appliance adapted to lie within the mouth of an athlete consists of an occlusal posterior pad made of quadruple composite material comprising four layers of distinct materials, further comprising a first layer of a durable, resilient material; a second layer of non-softenable, flexible material; a third layer of a hard, very durable material; and a fourth layer of a softenable material, engageable with the occlusal surfaces to space apart the upper and lower teeth, to absorb shock and clenching stress. An adjustable arch adapted to expand and contract to be molded to the palate is provided connecting the posterior pads together within the mouth and out of the way of the tongue to maintain the position of the occlusal posterior pads within the mouth during use and to prevent loss of the pads such as by swallowing. An expandable serpentine bridge may be embedded in the arch. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
None
BACKGROUND OF THE INVENTION
The use of natural-appearing materials such as slate or wood shake for composite shingles is a very established practice in building construction. These natural materials are coveted for their appearance and material properties. However, the use of natural materials often has drawbacks that make them less desirable and uneconomical for many applications in modern building construction. Natural slate is coveted for its appearance and durability; however, slate is a very heavy building material with high material and installation costs. The material cost for slate shingles is much greater than the standard asphalt shingles used in most residential construction and its use in certain applications is nearly cost prohibitive. In addition to the higher material price, slate shingles have high installation costs because the shingles must be hand nailed due to the tendency of slate to chip or split under the impact of a nail driven by a pneumatic nail gun. To further add to its disadvantages, slate shingles are much heavier than asphalt shingles. Traditional roof construction may not always be adequate to support the weight of slate shingles; as a result, the structure supporting a slate roof must be stronger to accommodate the increased loads. The increased design load associated with slate shingles ultimately increases entire structure costs as the extra load in the roof must be carried all the way down to the foundations.
Wood shake shingles are similar in weight to common asphalt shingles and do not require increased structure costs; however, wood shingles also have some competitive drawbacks in modern construction. Wood shingles do not have an equivalent life span to asphalt shingles; thus, they need to be replaced much sooner. Further, wood shingles are typically more expensive than asphalt shingles thereby increasing the up front material costs. Wood shingles without sufficient sun exposure are subject to the growth of moss and subsequent rot. Wood shingles also absorb water which results in a tendency to curl and not remain flat on the roof. Wood shingle roofs require frequent “conditioning” wherein rotten shingles are identified and replaced. All of these factors result in increased maintenance costs. Further, wood shingles do not have the fire resistance of asphalt shingles and, in fact, may create a fire hazard as wood shingles are often dry and can actually accelerate a fire if an errant airborne cinder lands on the roof.
Because of the aesthetic appeal of slate and wooden shake shingles, light weight composite shingles made to resemble slate and wooden shake shingles have been developed. Advancements in composite materials have made it possible to manufacture composite shingles that are colored and textured to realistically imitate slate or wood shake shingles. Composite shingles have many advantages over shingles made from natural materials. Composite shingles are lighter in weight and allow a homeowner to obtain the look of slate while maintaining the structural load and framing requirements for a roof with traditional asphalt shingles. Composite shingles will not rot and often have at least a fifty-year life span resulting in low maintenance costs during a roofs life span. Some composite shingles can be installed using a pneumatic nail gun to reduce installation costs. For someone seeking the look of a slate roof, without the associated high cost of materials and installation, composite shingles have great appeal. Likewise, a consumer desiring the look of wooden shake shingles but with lower maintenance costs and increased life span, composite roof shingles have great appeal.
As the demand for composite shingles has increased, many improvements have been made to increase the performance of previous generations of composite shingles. Technologies improving the manufacturing efficiency allow composite shingles to be made with less material. In addition, alignment aids, such as laying lines, scales and spacing nibs, increase the efficiency of installation. However, known composite shingles still have performance defects. For example, when shingles include a cavity under the top surface to achieve a greater, more realistic height while still maintaining a low shingle weight, the top surface often deforms when the composite shingles sit in the sun for prolonged periods of time, thereby creating sag in the middle of the shingle or between the surface supports. Support rails are often added lengthwise within the cavity under the top surface for support in an attempt to remediate this problem; however, while support rails helped reduce the sag in the middle previously experienced, sag between the support rails is still present. In addition, by only including lengthwise support rails, the shingle is still vulnerable to buckling upon application of an uplift force load due to wind loads. In an attempt to adequately resist uplift forces, these rails must be thick to prevent buckling which increases the amount of material required and thus the overall weight of the shingle.
A need exists to increase the performance and efficiency of the structural design of composite shingles with a thick butt end and a formed cavity below the top surface all the while meeting the manufacturing and material constraints of the industry. Improvements of the present invention reduce or maintain the amount of material used in manufacture while simultaneously maintaining or increasing the performance of composite shingles.
SUMMARY OF THE INVENTION
The present invention is generally directed toward a thick butt end composite shingle including a body shell including a top surface, a bottom surface, a butt end wall, a first side wall, second side wall, a tab portion and a lap portion. A portion of the top surface of the body shell may be textured to resemble slate or wood shake shingles. The butt end wall includes a height that creates a shingle profile to more closely resemble natural slate or shake shingles. The first side wall and second side wall generally taper from a greater height at the butt end to a lesser height at the top end. The longitudinal ribs generally extend downward from the bottom surface of the body shell to a common plane. A plurality of rib stiffeners are provided and also extend from the bottom surface of the body shell to the common plane. Further, the rib stiffeners are generally integral to the longitudinal ribs and laterally reinforce the longitudinal ribs at intersection points along the length of the longitudinal ribs.
The rib stiffeners may include a material saving profile having a smaller depth in the mid portion of the stiffener than at the ends, for example, a notched “V” or arched profile. This material saving profile still provides the necessary force transfer and stiffening properties, as well as reduces the amount of material required to manufacture the composite shingle. Generally, rib stiffeners have an orientation with respect to the longitudinal ribs having an angle of incidence less than ninety degrees. The rib stiffeners may be positioned in a centered rectangular lattice pattern or other pattern that creates an adequate framework to support the top-surface of the composite shingle.
The rib stiffeners can support the body shell and greatly reduce the effective span of the body shell using plate action to reduce shear and bending loads. A reduced effective span allows the body shell thickness to be less, thereby further reducing the material required to make the composite shingle. Additionally, rib stiffeners reduce the unbraced length of the bottom edge of the longitudinal ribs. When the body shell is subjected to an uplift force due to wind loads, the bottom edge of the longitudinal ribs is subjected to compression and the composite shingle is vulnerable to web buckling. The reduced unbraced length of the bottom edge increases the composite shingles resistance to buckling caused by uplift. Further, stiffening the longitudinal ribs allows the longitudinal ribs to be narrower; thus, providing the ability to further reduce the amount of raw material required per shingle.
The composite shingle may also include a nailing zone and/or nailing zone ribs. A nailing zone is generally a recessed portion of the top surface located in the lap portion of body shell. The recessed portion allows a head of a fully driven nail to be below the general bearing plane of the top surface of the shingle. The depressed nailing zone also can visually identify to an installer the proper locations to drive the roofing nails. Further, embodiments of composite shingle 10 use nailing zone ribs integral with the depressed nailing zone. These nailing zone ribs strengthen the area surrounding the nailing zone. The nailing zone is subjected to stress concentrations during installation from the use of pneumatically driven fasteners and throughout the life of the composite shingle from being the anchoring point of the composite shingle. Generally, the nailing zone ribs extend downward from the bottom surface of the body shell in direct proximity to the nailing zone. The nailing zone ribs are generally spaced closer together than the longitudinal ribs, but far enough apart that a fastener body may be driven between the ribs. In addition, the nailing zone rib spacing may be set to prevent a fastener head from passing between two adjacent nailing zone ribs.
An additional embodiment of the composite shingle further comprises alignment aids. Alignment aids may be a laying line, spacing nibs and/or a scale on the top surface. An embodiment of composite shingle includes an alignment aid comprising a laying line. A laying line includes a width that facilitates the application of a second course of composite shingles on top of an underlying course of composite shingles by providing a guide that allows for proper spacing between each of the composite shingles on the second course and ensuring second course is properly aligned with first course. Alternatively, the alignment aid may include at least two spacing nibs. The spacing nibs extend outwardly from the left-side wall, the first side wall, or both side walls. The spacing nibs aid an installer in properly spacing the shingles horizontally when installing composite shingles on the roof. Certain embodiments of the composite shingle include at least two nibs on one side wall. Two spacing nibs on one side wall help square the first shingle in relation to a second shingle horizontally adjacent to it. Additionally, the spacing nibs may be used in concert with the scale located on the top surface of the body shell to help an installer create offset composite shingle patterns or help make sure all the composite shingles have a uniform tab exposure.
A plurality of assembled composite shingles, as presented above, is also claimed as part of this invention. Finally, a method of applying multiple courses of shingles on a roof comprising the steps of providing an underlying shingle, coupling the underlying shingle to the roof, laying an overlying shingle of the type presented above on top of a least a portion of the underlying shingle and coupling the overlapping shingle to the roof.
Further, the method may also include providing a second overlapping shingle as presented above, laying the second overlapping shingle, horizontally proximate to first overlapping shingle, on at least a portion of the underlying shingle wherein the spacing nibs of the second overlapping shingle are in proximate contact with the first overlapping shingle and coupling the second overlapping shingle to the roof.
Additional objects, advantages and novel features of the composite shingle will be set forth in part in the description which follows, and will in part become apparent to those in the practice of the invention, when considered with the attached figures.
DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith in which like reference numerals are used to indicate like or similar parts in the various views:
FIG. 1 is a top plan view of a composite shingle according to an embodiment of the composite shingle;
FIG. 2 is a bottom plan view of a composite shingle according to an embodiment of the composite shingle;
FIG. 3 is a bottom perspective view of a composite shingle according to an embodiment of the composite shingle; and
FIG. 4 is a top perspective view of an assembly of composite shingles according to an embodiment of the composite shingle.
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawings.
Referring now to FIGS. 1 and 2 , reference numeral 10 generally denotes a composite shingle. Composite shingle 10 may be formed of any suitable material such as, but not limited to, rubber (e.g., ground up tire rubber), polymers such as polyethylene (e.g., various grades, recycled or virgin), fillers (e.g., wood fibers, glass, stone, limestone), asphalt embedded mats, tile, or any or suitable material. Further, composite shingle 10 may be made and cut, or molded, to any shape desired using known techniques. For example, one manner of making composite shingle 10 is through use of a combination mixer and extruder; however, any method to make composite building materials known in art may be utilized to manufacture composite shingle 10 . Natural versions of shingle 10 may also be made of stone, slate, wood, or any other suitable material and may be cut to shape using known techniques.
Shingle 10 generally includes a body shell 12 having a top surface 16 , a bottom surface 18 , a top end 20 , a butt end 22 , a first edge 24 , and a second edge 26 . Further, shell 12 includes a thickness defined as the distance between top surface 16 and bottom surface 18 from about 1/16 inches to about 1 inch or any other thickness suitable for use in the present invention and sufficient to meet applicable industry design standards. It will be appreciated that first and second edges 24 , 26 may also be referred to as a right edge or left edge or a leading edge or trailing edge depending on the direction the shingles are being laid on the roof (i.e., right to left or left to right). Top surface 16 generally includes a lap portion 28 and a tab portion 30 . In one embodiment, tab portion 30 of top surface 16 includes a textured face 32 configured to resemble either wood shake shingles or slate shingles. Additional embodiments may include texturing tab portion 30 to resemble shingles made of other suitable materials or having a desired aesthetic design. For example, at least a portion of top surface 16 may be textured to resemble slate or wood, and texturing may be accomplished by molding, cutting or otherwise forming one side to simulate natural slate or wood. When an embodiment includes a textured top surface 16 , the textured area of top surface 16 may range from just tab portion 30 to the entire top surface 16 .
As shown in FIG. 1 , shingle 10 may include at least one nailing zone 34 located on top surface 16 . Nailing zone 34 is an area in which shingle 10 can be fastened to a roof by a nail, adhesive or any other suitable method or device. Nailing zone 34 is generally positioned on top surface 16 so that shingle 10 will be adequately secured to the roof and also so that nailing zone 34 is covered by an overlying shingle. Nailing zone 34 may a rectangle, a square, a circle or any other shape suitable for use in the present invention. In the embodiment shown, a first nailing zone 34 a is generally disposed toward the bottom end of tab portion 30 proximate first edge 24 and a second nailing zone 34 b is generally disposed toward the bottom end of tab portion 30 proximate second edge 26 . Nailing zone 34 may be flat or recessed below the common plane of top surface 16 of body shell 12 and is configured to allow for the head of a fully driven nail to be below the general bearing plane of an overlapping shingle. Top surface 16 may also include at least one nail location indicia 36 proximate the top of nailing zone 34 to indicate to an installer where the nail or other suitable fastener should be driven.
In certain embodiments of the present invention, alignment aids such as a laying line 38 , at least one spacing nib 48 , and at least one scale 52 may be provided anywhere on top surface 16 to facilitate the alignment of an overlying course of composite shingles 10 with respect to an underlying course of shingles 10 . Laying line 38 , spacing nib 48 and scale 52 , as incorporated into the present invention are fully disclosed in U.S. Pat. No. 7,475,516 to Jolitz et al. and U.S. Pat. No. 7,516,593 to Jolitz et al. which are hereby incorporated by reference. In the embodiment shown in FIG. 1 , laying line 38 is generally centrally disposed on top surface 16 proximate to top end 20 . Laying line 38 may be thin or thick and may be a single line, a pair of lines, or a series of lines: As further illustrated, laying line 38 includes a left edge 40 and a right edge 42 that may also be referred to as a near edge and a far edge depending on the direction the shingles are being laid on the roof. Laying line 38 may extend downwardly from top end 20 to a length 44 . A suitable length 44 may be any length that is equal to or less than the entire length of the non-exposed portion of shingle 10 . The non-exposed portion is the amount of shingle 10 that is covered by the second course of shingles laid on top thereof. For example, suitable lengths 44 may vary from about 1 to 6 inches or longer depending upon the particular application. It is also within the scope of the present invention to provide a laying line 38 that is slightly raised or elevated from top surface 16 or perhaps colored so as to contrast with the remainder of top surface 16 .
Furthermore, laying line 38 has a width 46 that has a thickness sufficient to allow laying line 38 to be at least partially exposed when the edge of an overlying shingle is placed in contacting proximity or aligned with either left or right edge 40 , 42 . For example, a suitable width 46 for laying line 38 may be at least about ⅛ inches, but it will be understood that other widths such as, but not limited to 3/16 inches, ¼ inches, or ½ inches are also within the scope of the present invention. It will also be understood that the term “exposed” should be interpreted as meaning “visibly exposed” and “non-visibly exposed.”
In certain embodiments, composite shingle 10 may also include at least one spacing nib 48 to aid in spacing of shingles and to keep subsequent shingles aligned horizontally aligned with composite shingle 10 . As shown in FIG. 1 , two spacing nibs 48 outwardly extend from each of first edge 24 and second edge 26 . It will be appreciated that shingle 10 may include more than two nibs on each side, a single nib on each side, or no nibs extending from either first or second edge 24 , 26 . Each of nibs 48 may include an apex having a pointed or a rounded end and extends to a nib width 50 . It will be appreciated by those skilled in the art that the widths 50 are preferably equal but different widths are well within the scope of the present invention. Moreover, width 50 may be less than, greater than, or equal to width 46 of laying line 38 . Nibs 48 may be spaced apart at generally the same distance on each or first and second edges 24 , 26 or nibs 48 on first edge 24 may be staggered lower than nibs 48 located on second edge 26 or vice versa so that nibs 48 extending from first edge 24 would not occupy same position as opposing spacing nibs 48 on second edge 26 of an adjacent composite shingle 10 thereby allowing a course of composite shingles 10 to maintain the desired spacing. Finally, nibs 48 may include thermal expansion relief characteristics as taught in U.S. application Ser. No. 11/463,445 to Shadwell et al. which is hereby incorporated by reference.
In certain embodiments, at least one scale 52 is located on top surface 16 and extends inwardly from each of first and second edges 24 , 26 . Scale 52 includes a center tick 54 , a lower tick 56 positioned below center tick 54 , and an upper tick 58 positioned above center tick 54 . Each tick may be assigned a number that corresponds to the amount that an underlying shingle will be exposed when the tick mark is aligned with the top end 20 of the underlying shingle. For example, upper tick 58 may be assigned a number “8” that would indicate to an installer that 8 inches or any other unit of measurement of an underlying shingle would be exposed if tick 58 was aligned with the top end 20 of the underlying shingle. Scale 52 , alone or in combination with spacing nibs 48 , can be used by an installer to ensure a uniform exposure of tab portion 30 or aid in setting a staggered shingle pattern having varying tab portion 30 exposures.
Referring now to FIGS. 2 and 3 (disclosing the bottom surface of the shingle), bottom surface 18 of body shell 12 generally includes top end 20 , a first side wall 60 extending along first edge 24 , a second side wall 62 extending along second edge 26 , and a butt end wall 64 extending along butt end 22 . Side walls 60 , 62 and butt end wall 64 cooperatively define a cavity 66 and may be textured to match the texture of top surface 16 . As shown more clearly in FIG. 3 , top end 20 has a top end height 68 approximately equal to the thickness of body shell 12 whereas butt end wall 64 has a butt end height 70 of from about ⅛ inch to about 1.5 inches although any height suitable for a particular use or application may be used. First side wall 60 gradually tapers and decreases in height 72 from butt end 22 to top end 20 . Similarly, second side wall 62 also gradually tapers and decreases in height 74 from butt end 22 to top end 20 . It will be appreciated that the degree of tapering between first and second side walls 48 and 50 will be generally identical and uniform from butt end 22 to top end 20 .
Bottom surface 18 of body shell 12 further includes a plurality of longitudinal ribs 76 most of which extend substantially along the length of the shingle and are configured to support body shell 12 so as to prevent shell 12 from bending or displacing. Longitudinal ribs 76 generally include a first end 78 , a second end 80 , a top edge 82 and a bottom edge 84 and extend longitudinally from first end 78 located proximate to the butt end 22 to second end 80 located proximate to the top end 20 . It will be appreciated that the length and therefore the location of second end 80 of each longitudinal rib 76 may be the same or different and may also be alternately staggered. Longitudinal ribs 76 generally extend downwardly from bottom surface 18 of body shell 12 to a common plane.
In certain embodiments, bottom surface 18 may include transverse ribs 86 generally extending perpendicularly to longitudinal ribs 76 . Transverse ribs 86 may be spaced along the length of composite shingle 10 and generally extend from between first side wall 60 and its nearest longitudinal rib 76 and from between second side wall 62 and its nearest longitudinal rib 76 . A plurality of x-shaped rib stiffeners 88 are also provided although it will be appreciated that rib stiffeners 88 may be any shape suitable for use in the present invention. Rib stiffeners 88 generally include a first end 90 and a second end 92 and may be integral with longitudinal ribs 76 having an angle of incidence 94 with respect to longitudinal ribs 76 of less than ninety degrees as illustrated in FIG. 2 . Further, longitudinal ribs 76 in conjunction with rib stiffeners 88 may be spaced and orientated to create a lattice pattern or any or pattern suitable for use in the present invention. In general, first end 90 of rib stiffener 88 may be integral with a longitudinal rib 76 at an intersection point 96 . A plurality of intersection points 96 are spaced along the length of longitudinal rib 76 . Second end 92 may be integral with a second longitudinal rib 76 at another intersection point 96 along the length of second longitudinal rib 76 . Certain embodiments include rib stiffeners 88 in a centered rectangular lattice pattern. FIG. 3 illustrates one embodiment including rib stiffeners 88 in a centered square lattice pattern wherein the angle of incidence 94 with longitudinal ribs 76 is about forty-five degrees.
Rib stiffener 88 may further include a material saving profile 98 having an end height 100 at intersection point 96 that is greater than a midpoint recess depth 102 . Alternatively, rib stiffener 88 may have a constant height over the entire length as plurality of longitudinal ribs 76 . The embodiment illustrated in FIG. 3 includes rib stiffeners 88 having a generally arched cross-section. Another embodiment may include a v-shaped stiffener or any shape with a recessed midpoint. In certain embodiments, the amount of exposed top side of each rib stiffener 88 decreases due to a decrease in side wall heights 72 , 74 as side walls 60 and 62 taper from butt end 22 to top end 20 . In other embodiments, an interrupted rib stiffener may be provided. Interrupted rib stiffener may result from side wall heights 72 , 74 not exceeding midpoint recess depth 102 of rib stiffener 88 plus the shingle thickness as heights 72 , 74 taper from butt end 22 to top end 20 . Alternate embodiments include a rib stiffener 88 with material saving profile wherein midpoint recess depth 102 may be decreased as heights 72 , 74 decrease, or alternatively, a rib stiffener 88 may have a uniform profile wherein its height is adjusted proportionately to match that of longitudinal ribs 76 at each intersection point 96 .
The spacing between rib stiffeners 88 is dependent on both downward shear force and the thickness of body shell 12 and the uplift force, primarily due to wind loading, that body shell 12 must resist. Rib stiffeners 88 work with body shell 12 and longitudinal ribs 76 to resist force due to both shear and bending. Rib stiffeners 88 allow designers to use less material in body shell 12 and longitudinal ribs 76 because rib stiffeners 88 can be used to reduce shear stress on body shell 12 at top edge 82 of longitudinal rib 76 by reducing the effective span of body shell 12 through plate action. Rib stiffeners 88 can also increase the structural resistance of composite shingle 10 when uplift force causes compression in bottom edge 84 of longitudinal rib 76 by reducing an unbraced length of bottom edge 84 . FIGS. 2 and 3 illustrate an embodiment of composite shingle 10 that utilizes a center rectangular lattice pattern having a longitudinal rib spacing of about 1 inch, and a rib stiffener spacing of about 1.4 inches, and an unbraced length of about 2 inches.
FIGS. 2 and 3 also illustrate one embodiment of composite shingle 10 that includes a plurality of nailing zone ribs 110 located between longitudinal ribs 76 . Nailing zone ribs 110 generally extend downwardly from bottom surface 18 and located generally beneath nailing zone 34 . Concentrated stress forces occur at anchoring locations (the locations where fasteners couple composite shingle 10 to the roof) and nailing zone ribs 110 are configured to reinforce composite shingle 10 at these high stress locations. Alternatively, increasing the strength of composite shingle 10 at anchoring locations could also be achieved by increasing thickness of body shell 12 at these locations. Nailing zone ribs 110 can also be used to reinforce nailing zone 34 so that a pneumatically driven fastener does not shear through body shell 12 of composite shingle 10 .
The dimensions of composite shingle 10 may be altered depending at least in part upon the application or design considerations for which composite shingle 10 will be used. For example, composite shingle 10 may be ¼ inches thick, 12 inches wide and 18 inches long.
A composite shingle 10 constructed in accordance with the present invention may be used to form a roofing system, or at least a portion thereof. Turning now to FIG. 4 , an assembly 200 of composite shingles 10 includes a first course 210 and a second course 212 of composite shingles 10 on a roof. Composite shingle 10 can be used to shingle a roof using methods well known in the art including the use of a pneumatic nailing gun to affix composite shingle 10 to the roof. In a typical installation method, a waterproof membrane, such as roofing paper is applied to the roof. Next, composite shingles 10 are installed on the roof beginning with first course 210 . Each course consists of laying shingles in horizontal proximity to each other to form a first row. In some embodiments of an assembly of composite shingle 10 , spacing nibs 48 and/or laying line 38 are used to uniformly position adjacent composite shingles 10 and help an installer properly align composite shingles 10 .
Each composite shingle 10 is then individually coupled to the roof. Typically, composite shingles 10 are coupled to the roof using either hand driven fasteners or pneumatically driven fasteners. One embodiment of the present invention utilizes either hand driven or pneumatic driven roofing nails. Composite shingle 10 should not be limited to being coupled to the roof using roofing nails; however, roofing nails are currently the industry standard. Some embodiments of composite shingle 10 utilize nailing zones 20 to provide a designated area in which an installer should drive a fastener. Additional embodiments provide for nail location indicia 36 on top surface 16 of body shell 12 to specifically identify the point on composite shingle 10 where a fastener should be driven. Each shingle should be coupled to the roof with at least two fasteners.
When first course 210 has progressed, then second course 212 may be started. Second course 212 positions tab portion 30 of composite shingle 10 overlapping lap portion 28 of first course 210 of composite shingles 10 . In addition, second course 212 of composite shingles 10 are horizontally staggered such that vertical joint 214 between two adjacent composite shingles 10 on first course 210 is overlapped by tab portion 30 of composite shingle 10 of second course 212 . The placement of composite shingle 10 repeats in the same manner for the entire roof. An alternative embodiment includes using alignment aids such as a laying line 38 , spacing nibs 48 and scale 52 that facilitates the application of second course 212 of composite shingles 10 on top of first course 210 of shingles by providing a guide that allows for proper spacing between each composite shingle 10 on second course 212 and ensuring second course 212 is properly aligned with first course 210 . FIG. 4 illustrates an exemplary partial layout of first course 210 and second course 212 of composite shingle 10 . Subsequent courses are laid until the entire roof is covered. When composite shingles 10 have reached the upper-most point of the roof or a change in roof plane, any number of specially formed hip or ridge members are used at any transition in the roof plane to complete composite shingle 10 installation.
While particular embodiments of the invention have been shown, it will be understood, of course, that the invention is not limited thereto, since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. Reasonable variation and modification are possible within the scope of the foregoing disclosure of the invention without departing from the spirit of the invention. | A composite shingle having unitary construction is presented that includes a body shell, a plurality of longitudinal ribs, and a plurality of rib stiffeners. The present composite shingle may also include transverse ribs, a depressed nailing zone, nailing zone ribs, and/or at least one alignment aid. The plurality of rib stiffeners may include a material saving profile. Further, the dimensions of the composite shingle more closely resemble true slate and shake shingles and at least a portion of the outside face of composite shingle may be textured to resemble slate or wood shake shingles.
A plurality of assembled composite shingles of the present invention is also claimed as part of this invention. Finally, a method of applying multiple courses of shingles on a roof including the composite shingle of the present invention is presented. | 4 |
BACKGROUND OF INVENTION
[0001] 1. Field of Invention
[0002] The invention concerns a device for post-treatment of exhaust gases from internal combustion engines, in particular lean-burn internal combustion engines of motor vehicles.
[0003] 2. Description of Prior Art
[0004] The use of SCR catalysts to reduce the nitrous oxides in an exhaust gas flow from an internal combustion engine is generally known. As part of the selective catalytic reduction (SCR) performed with this SCR catalyst, a substance with directly reducing action is supplied to the exhaust gas flow, such as ammonia or a pre-product which only releases reducing substances in the exhaust gas. The pre-product can for example be a watery urea solution.
[0005] In internal combustion engines operated in motor vehicles, nitrous oxide reduction with the SCR process is therefore difficult because firstly fluctuating operating conditions predominate here which makes it difficult to supply the reducing agent in the correct quantities, and secondly for safety reasons the extremely reactive reducing agent ammonia cannot be used directly but must be produced by the decomposition of ammonia precursor substances such as urea, guanidinium formiate, ammonium carbonate, etc.
[0006] Also it must be noted that although firstly as high a conversion rate of nitrous oxides as possible is to be achieved, secondly unnecessary emissions of unconsumed reducing agent such as for example ammonia must be avoided.
[0007] In connection with the decomposition of urea into ammonia, it is known that under optimum conditions, i.e., at temperatures above 350° C., this takes place in two stages. According to
[0000] (NH 2 ) 2 CO→NH 3 +HNCO (1)
[0000] first thermolysis takes place, i.e., the chemical decomposition of urea. Then according to
[0000] HNCO+H 2 O→NH 3 +CO 2 (2)
[0000] hydrolysis occurs, i.e., the catalytic decomposition of iscocyanic add (HNCO) into ammonia (NH 3 ) and carbon dioxide (CO 2 ).
[0008] To convert one mole of nitrous monoxide, one mole of ammonia is needed.
[0000] 4NO+4NH 3 +O 2 →4N 2 +6H 2 O (3)
[0009] The ratio between NH 3 and NO x is known as the feed ratio α.
[0000] α=NH 3 /NO x (4)
[0010] In an ideal catalyst this means that with a feed ratio of one, all nitrous oxides are reduced so that a 100% NO x conversion is achieved, because for the NO x conversion X Nox :
[0000]
X
NOx
=
c
NOx
,
0
-
c
NOx
c
NOx
,
0
(
5
)
[0000] where: c NOx,0 : untreated NO x emissions [ppm]
c NOx : NO x emissions after catalyst [ppm]
[0012] If the quantity of ammonia supplied exceeds that of the converted nitrous oxides, unconsumed ammonia is emitted. Because of its toxicity, this must be avoided under all circumstances.
[0013] To better understand the process at the catalyst, some reaction principles are outlined briefly below.
[0014] If we consider the reaction
[0000] | 1 |·A 1 +| 2 |·A 2 →| 3 |·A 3 +| 4 |·A 4 (6)
[0000] where: A1, A2: educts
A3, A4: products v 1 : stoichiometric factors v 1 <0 for educt v 1 >0 for product
then this proceeds at a specific speed known as the reaction speed “r” (7). This is defined as the temporal change in the component “i” in relation to the stoichiometric factor. It therefore relates to a reaction equation and is valueless without this being specified.
[0000]
r
=
1
v
i
·
n
i
t
(
7
)
[0000] where: n i : mole count of component i [mol]
t: time [s]
[0020] For a volume-resistant reaction, the mole count change “dn i ” can be replaced by the concentration change “dc i ”:
[0000]
r
=
1
v
i
·
c
i
t
(
8
)
[0000] where: c i ; concentration of component i [mol/m3]
[0021] If it is not the speed of a particular reaction which is important but the change of a component, then the substance quantity change rate “R” is used.
[0000]
R
i
=
c
i
t
(
9
)
[0022] For the case of N reactions therefore:
[0000]
R
i
=
c
i
t
=
∑
j
=
1
N
v
ij
·
r
j
(
10
)
[0023] To allow better comparison of reaction speed and substance quantity change rate of different catalysts, these are related to representative values such as, e.g., the catalyst mass, the catalyst volume or the phase boundary area.
[0024] There are several ways of describing the correlations determining the reaction speed, one of which is the so-called potency method which is used if the reaction mechanism is unknown.
[0000] r=k·c 1 m 1 ·c 2 m 2 (11)
[0000] where k: speed constant of reaction
m: order of magnitude in relation to reactants Ai, m i ∈R m:
[0000]
m
=
∑
i
=
1
N
m
i
[0000] : total order of reaction
[0027] The part orders “m i ” of the reactants are normally determined from laboratory measurements.
[0028] The speed of a reaction depends not only on the concentration of the educts and their order, but naturally also on the temperature “T”. In the above method this is contained in the speed constant “k”.
[0000]
k
=
k
O
·
(
-
E
A
R
·
T
)
(
12
)
[0000] where k O : frequency or shock factor [mol 1−m ·s −1 ]
E A : activation energy [J/mol] R: general gas constant 8.31 J/molK
[0031] For the substance change speed for NO at SCR catalysts, a so-called formal kinetic method (potency method) can be used in the form
[0000] R NO =k·c NO m ·c NH 3 n (13)
[0000] wherein “m” normally assumes the value “one” and “n” the value “zero”.
[0032] In practical terms this means that the substance quantity change rate can be increased by raising the NO concentration, while an increase in NH 3 concentration has no effect on this.
[0033] If a platinum-containing NO oxidation catalyst is connected before the SCR catalyst to form NO 2
[0000] 2NO+O 2 2NO 2 (14)
[0000] then the SCR reaction can be substantially accelerated and the low temperature activity perceptibly increased.
[0000] NO+2NH 3 +NO 2 →2N 2 +3H 2 O (15)
[0034] Since the reducing agent, e.g., on use of the reducing fluid known as AdBlue®, is present in a form dissolved in water, this water must be evaporated before and during the actual thermolysis and hydrolysis, if the temperatures in the two reactions above lie below 350° C. or if heating takes place only slowly, mainly solid, unmeltable cyanuric add is formed by trimerisation of the isocyanic acid, which leads to solid deposits on or even clogging of the SCR catalyst. This can be remedied as described in DE 40 38 054 A1 in that the exhaust gas flow charged with the reducing agent is passed over a hydrolysis catalyst. The exhaust gas temperature at which quantitative hydrolysis is possible can thus be lowered to 160° C. as long as the urea quantities added are not too great, Such an additional hydrolysis catalyst however further increases the cost of the arrangement for exhaust gas post-treatment.
[0035] Despite these measures it is often not possible to avoid the formation of cyanuric acid, melamine or other undesirable solid reaction products, in particular if the NH 3 precursor substance, such as urea or urea watery solution, and the exhaust gas are not evenly distributed over the entire flow cross section or the quantities added are too great. It is particularly critical here if locally large quantities of reducing agents make contact with the pipe walls or urea decomposition catalysts while at the same time at this point there is a local minimum flow speed. This has the result that the exhaust gas cannot provide sufficiently high heat quantities to ensure a quantitative decomposition of the reducing agent into NH 3 , Rather at these points, said deposits of undesirable reducing agent decomposition products occur.
[0036] This effect is further amplified by the fact that in vehicles only a very restricted construction space is available for preparation of the reducing agent, which means that in particular in the inflow to the catalyst, the inlet lengths are very short, which in turn leads to a very poor equidistribution over the catalyst cross section because of the flow dead zones, cross section changes and/or flow stalling.
[0037] All this has the result that the NO x conversion is not usually limited by the actual SCR reaction but by the release of ammonia from its precursor substances.
[0038] DE 3604045C1 and EP 362 483 A1 disclose methods of using a periodically fluctuating addition of ammonia instead of a continuous, stationary ammonia addition, in order to raise the NO x conversion rate at the SCR catalyst.
[0039] Here briefly more ammonia is added than would be necessary under stationary conditions, in particular the feed ratio here can rise above one, and then the ammonia quantity falls below the quantity necessary under stationary conditions or is even interrupted completely.
[0040] The reason for the rise in NO x conversion observed with this process is the inhibition of educts by ammonia, which can be reduced by briefly lowering the NH 3 quantity in the exhaust gas and hence on the catalyst surface.
[0041] This method cannot however simply be applied to SCR systems which do not use pure ammonia but an ammonia precursor substance, since because of the periodically very great over-supply, usually the decomposition of reaction medium is incomplete and consequently deposits occur in the form of cyanuric acid, melamine, etc.
SUMMARY OF THE INVENTION
[0042] The object of the invention is to propose a method for post-treatment of exhaust gases in an exhaust gas system of internal combustion engines, in particular lean-burn internal combustion engines of motor vehicles, which in a simple and reliable manner allows a functional, in particular quantitatively improved NO x conversion in the exhaust gas.
[0043] To reduce the educt inhibition by ammonia deposited on the catalyst surface, the untreated NO x emissions are periodically raised and lowered without adapting the supplied quantity of reducing agent accordingly, in particular proportionally. This has the consequence that in phases with high untreated NO x emissions, the NO x quantity exceeds the supplied quantity of reducing agent so that the feed ratio falls, which in turn has the consequence that the NO x reacts with the ammonia deposited on the catalyst so that its ammonia charge falls, since this is now consumed, without it being able to be replaced by sufficient NH 3 from the gas phase. In addition by the increase in untreated NO x emission as described above, the substance quantity change rate and hence the converted NO x quantity are raised.
[0044] In phases with low untreated NO x emission however the supplied quantity of reducing agent exceeds the quantity necessary for the corresponding NO x conversion, so that a high feed ratio is present, whereby the catalyst is again charged with ammonia.
[0045] The advantage of this method is that it is possible to change the quantity of NH 3 stored on the catalyst even under usage conditions critical for the decomposition of reducing agent, such as low exhaust gas temperature and/or low exhaust gas mass flow, since there is no need to increase the reducing agent quantity to recharge the catalyst with ammonia. In addition the converted NO x quantity is raised by increasing the substance quantity change rate.
[0046] The method also allows operation of the internal combustion engine, at least in phases, at a higher NO x level which usually leads to improved efficiency and hence lower fuel consumption.
[0047] To accelerate the “discharge” of ammonia from the catalyst, it is possible in the phases with high untreated NO x emissions to lower the supplied quantity of reducing agent or interrupt it completely. Evidently in operating phases in which a secure reducing agent decomposition is guaranteed, it is also conceivable to raise the supplied quantity of reducing agent in the phases with low untreated NO x emissions and thus accelerate the deposition of ammonia. As already explained, the untreated NO x emissions can be varied by changing operating parameters of the internal combustion engine. Operating parameters which have a direct effect on the NO x emissions include the start of injection, the air/fuel ratio (lambda), the injection pressure, the number of individual injections per working cycle, the intake air temperature and the exhaust gas quantity recirculated (EGR rate) where exhaust gas recirculation is provided, Here the following changes in the above operating parameters lead to a rise in untreated NO x emissions:
advance of injection start, shift in the air/fuel ratio in the direction of higher lambda values, increase in injection pressure, reduction in the number of individual injections per working cycle, increase in intake air temperature, e.g., by bypassing the charge air cooler, reduction in the quantity of recirculated exhaust gas.
[0054] Evidently the measures to increase or reduce the untreated NO x emissions must be adapted to the other operating conditions of the internal combustion engine, in particular when used in a motor vehicle, e.g., to the maximum possible cooling power of the engine cooling, the power requirement by the driver.
[0055] As the ammonia intake and output behaviour depends greatly on the operating conditions of the exhaust gas post-treatment, such as catalyst temperature, ammonia charge level of catalyst, NO x conversion rate, untreated NO x emissions, NO 2 emission upstream of the SCR catalyst, NO x emission after the system, NH 3 emission after the system, and supplied quantity of reducing agent, it is advantageous to make the period length and/or the amount of rise and/or the amount of fall and/or the duration of rise and/or the duration of fall of the untreated NO x emissions and/or the supplied quantity of reducing agent dependent on these values. The following correlation is observed:
[0056] The period duration and/or the amount of rise and/or the amount of fall and/or the duration of rise and/or the duration of fall of the untreated NO x emissions rise as the catalyst temperature falls and/or the NO 2 emissions upstream of the SCR catalyst fall when the NO 2 /NO x ratio is less than one, and/or as the NO 2 emissions upstream of the SCR catalyst rise when the NO 2 /NO x ratio is greater than one, and/or as the post-system NH 3 emissions fall and/or the supplied quantity of reducing agent fails and/or the NO x conversion rate falls and/or the post-system NO x emissions rise.
[0057] The operating conditions can be determined firstly directly via sensors or via models in the form of mathematical functions, maps and/or neuronal networks. Such techniques have been known to the person skilled in the art for some time so there is no need for a detailed description.
[0058] FIG. 5 is schematic diagram showing an SCR catalyst 10 with a clean gas side 11 in an exhaust flow of an internal combustion engine. Also shown is a reducing agent input 12 upstream of the SCR catalyst 10 . A charge of material with oxidative action arranged on the clean gas side 11 decomposes unconsumed NH 3 passing the SCR catalyst 10 .
BRIEF DESCRIPTION OF THE DRAWINGS
[0059] The function of the method proposed will be explained below in more detail with reference to some examples, with reference to the figures, in which:
[0060] FIG. 1 is a graph showing a principle depiction of the region within which the feed ratio is changed;
[0061] FIG. 2 is a graph showing a first example of a periodic curve of the NO x rise/NO x fall with constant reducing agent supply;
[0062] FIG. 3 is a graph showing NO x conversion rates in % at different catalyst temperatures and the curve of the NO x rise/NO x fall according to FIG. 2 ;
[0063] FIG. 4 is a graph showing a second example of a periodic curve of the NO x rise/NO x fall with constant reducing agent supply.
[0064] FIG. 5 is a schematic diagram of a exhaust flow in which the method of the present invention operates.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0065] FIG. 1 shows in a principle depiction the dependency of the catalyst temperature and feed ratio at an SCR catalyst in an internal combustion engine in relation to the maximum achievable conversion rate of nitrous oxides, where the abscissa shows the temperature and the ordinate the feed ratio αa. The curve shown by the solid line indicates the theoretical feed ratio α which would be selected for a specific catalyst temperature in order to achieve a maximum conversion rate at this catalyst temperature for the nitrous oxides supplied to the catalyst. It thus constitutes a theoretical stationary state. It has now been found that if the feed ratio α varies within particular limits which can be established only by experiment for a particular catalyst type as a function of the catalyst temperature, by changing the untreated NO x emissions accordingly, the NO x conversion rate can be increased substantially. Said limits are also shown in FIG. 1 related to temperature in order to clarify the correlation principle. The dashed line indicates the temperature-related upper limit and the dotted line the lower limit for the variation width of the feed ratio α. Explained using an example, this means that for a catalyst temperature of 250° C. the feed ratio α is varied about the theoretical value 0.5 at short intervals, e.g. periodically, within the limits of 0.25 and 0.8. This variation as already stated is achieved in that the untreated NO x emissions of the internal combustion engine are briefly raised and then lowered again. Measures on the engine which achieve this have been known to the person skilled in the art for some time and have already been discussed above.
[0066] In tests it has proved advantageous to vary the untreated NO x emissions and/or the feed ratio α by at least 20%, preferably by at least 40%, most preferably by at least 60%.
[0067] In order to show the influence of the variation of untreated NO x emissions on the conversion rate, measurements were carried out on a specimen catalyst as described below in connection with FIGS. 2 and 3 in one example. The measurements were made on an internal combustion engine of type MAN-D2676 with external, cooled exhaust gas recirculation, in the exhaust tract of which an SCR catalyst with the following values was fitted:
cell count: 300 cpsi active component: V 2 O 5 on WO 3 -stabilised TiO 2 volume: 30.3 l
[0071] The untreated NO x emissions were varied by variation of the exhaust gas quantity recirculated to the fresh air side (increase in EGR rate). The engine operating points were 1200 rpm/800 Nm, 1200 rpm/1200 Nm and 1200 rpm/1700 Nm; the resulting catalyst temperatures were 200° C., 300° C. and 400° C.
[0072] As shown in FIG. 2 , the NO x concentration (in ppm) was varied so as to give a periodic trapezoid curve, wherein the NO x concentration oscillated symmetrically about the NH 3 concentration of 1000 ppm between the limit values of 500 ppm and 1500 ppm; the period duration was four seconds. FIG. 3 shows the NO x conversion rates in % for the catalyst temperatures 200° C., 300° C. and 400° C. achieved under the conditions selected in FIG. 2 . As a comparison, FIG. 3 also shows the NO x conversion rates in % which were achieved with unvaried untreated NO x emissions, i.e. with period duration 0 seconds, and otherwise unchanged arrangement and procedure. It is not difficult to see that with the proposed method, a clear rise in NO x conversion rates is achieved even at low catalyst temperatures.
[0073] As FIG. 4 shows, the NO x concentration (in ppm) can naturally also be varied following another curve. A periodic rectangular curve is shown here, wherein the NO x concentration again oscillates symmetrically about the NH 3 concentration of 1000 ppm between the limit values 500 ppm and 1500 ppm.
[0074] The period duration, which in the example in FIG. 3 is two seconds, can be used as a parameter for optimising the NO x conversion rate. The same applies to the amplitude of variation. The feed ratio α need not necessarily oscillate symmetrically about the theoretical stationary value (solid line in FIG. 1 ); it can in practice prove more useful to select the falls and rises in untreated NO x emissions asymmetrically (dotted and dashed lines in FIG. 1 ). As already emphasised above, a generally valid variation of feed ratio α can only be specified in so far as the value a is varied positively and negatively about an assumed theoretical value and this variation must be achieved by brief rises and falls in the untreated NO x emissions. The optimum amount of rise and fall to a great extent depends on the catalyst materials used and must be determined empirically for a catalyst of a specific type.
[0075] The core concept of the proposed process is that the NO 3 to NO x ratio (feed ratio α) is varied by changing the untreated nitrous oxide emissions in phases such that the feed ratio α oscillates in phases about a theoretical stationary value.
[0076] Evidently it is also possible to vary the above process, described as an example. Thus it is possible to optimise the effect of the method in that the supplied quantity of reducing agent is not adapted according to, in particular not proportional to, the periodically fluctuating, untreated NO x emissions. Also a lowering of the reducing agent quantity is conceivable here but it must be ensured, e.g., by temperature detection before and/or at the SCR catalyst, that the temperature does not fall below a predefined level when the reducing agent quantity is increased again.
[0077] Furthermore it may be advantageous to select the period length and/or the amount of rise and/or the amount of fall and/or the duration of rise and/or the duration of fall of the untreated NO x emissions as a function of the operating conditions of the exhaust gas post-treatment system. The operating conditions taken into account here can be the catalyst temperature and/or the ammonia charge level of the catalyst and/or the NO x conversion rate and/or the untreated NO x emissions and/or the NO 2 quantity upstream of the particle filter and/or the NO x emissions downstream of the exhaust gas post-treatment system and/or the NH 3 emissions downstream of the exhaust gas post-treatment system and/or the supplied quantity of reducing agent and/or the stored quantity of NH 3 and/or the NH 3 quantity which can be stored. Such operating conditions can be determined via sensors and/or via models, in the form of mathematical functions, maps and/or neuronal networks. Such techniques are well known to the person skilled in the art so no detailed description is required.
[0078] If despite the proposed measures the SCR catalyst allows unconsumed NH 3 to pass, it can be provided that this is decomposed by a charge of material with oxidative action arranged on the clean gas side and/or by increasing an ammonia storage capacity in the direction of the clean gas side to be able to buffer the ammonia peaks by storage. | A method for use with an exhaust gas post-treatment system on an internal combustion engine operated with aft surplus includes reducing nitrous oxides in that an ammonia-separating reducing agent is added to the exhaust gas flow upstream of a catalyst which is charged with a catalyst material for selective catalytic reduction of nitrous oxides. The method further provides that the NH 3 to NO x ratio (feed ratio α) is varied in phases by changing the untreated nitrous oxide emissions of the internal combustion engine such that the feed ratio α oscillates in phases about a predefined value. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Application is a continuation of U.S. patent application Ser. No. 10/495,109, filed May 6, 2004 and bearing Attorney docket no. UNIV0006, the entirety of which is incorporated herein by this reference thereto.
TECHNICAL FIELD
[0002] The invention relates to network management technology. More particularly, the invention relates to an apparatus and method of policy publication, diffusion and enforcement for management of large-scale networks of computational devices.
BACKGROUND OF THE INVENTION
[0003] Information technology (IT) administrators in enterprises everywhere face a daunting task of managing the software and hardware on tens, hundreds, or thousands of machines in their domains. With so many incompatibilities, patches, and policy advisories announced daily, the task is much more than just acquisition and installation. Even simply keeping aware of all potentially problematic situations on hardware and software products used in an enterprise requires more than a full-time job. Dealing with those situations in response to user complaints adds still further taxing demands. Thus it is required that IT managers must anticipate the situations which may soon arise in a specific enterprise and make plans to deal with those before they cause major problems. This creates an urgent need of a technique which enables the IT managers to understand the configuration of the hardware and software in a given intranet, to keep track of the policy advisories, updates, incompatibilities and patches relevant to the specific enterprise, and to match those policy advisories, updates, and patches with the specific equipment in the enterprise.
[0004] Donoho et al disclose in U.S. Pat. No. 6,256,664 a technique which enables a collection of computers and associated communications infrastructure to offer a new communications process. This process allows information providers to broadcast information to a population of information consumers. The information may be targeted to those consumers who have a precisely formulated need for the information. This targeting may be based on information which is inaccessible to other communications protocols because, for example, under other protocols the targeting requires each potential recipient to reveal sensitive information, or under other protocols the targeting requires each potential recipient to reveal information obtainable after extensive calculations using data available only upon intimate knowledge of the consumer computer, its contents, and local environment.
[0005] This process enables efficient solutions to a variety of problems in modern life, including the automated technical support of modern computers. In the technical support application, the disclosed invention allows a provider to reach precisely those specific computers in a large consumer population which exhibit a specific combination of hardware, software, system settings, data, and local environment, and to offer the users of those computers appropriate remedies to correct problems known to affect computers in such situations.
[0006] FIG. 1 is a schematic block diagram illustrating a communications system for computed relevant messaging according to the prior art. A user directs an advice reader running on his computer 101 to subscribe to three advice provider sites 103 - 105 . The corresponding advice is brought into his computer in the form of digital documents, where the advice reader inspects the advisories for relevance. These digital documents are called advisories. The transfer from Internet 102 to computer is entirely one-way. No information about the user's machine goes back to the advice provider. An advice typically comprises three parts: (1) a relevance clause written in relevance language which is evaluated by the advice reader to determine the relevance of the advice; (2) a message body for providing explanatory material explaining to an advice consumer as to what condition is relevant, why the advice consumer is concerned, and what action is recommended; and (3) an action button for providing the advice consumer with the ability to invoke an automatic execution of a recommended action.
[0007] Whereas in the consumer setting it is acceptable for the computer user to be in control of the process, learning which problems exist and applying the fixes, in the enterprise setting it is often the case that end user administration of computers is frowned upon. Instead, computers are often managed centrally, and a system administrator is in charge of keeping configurations workable and avoiding enterprise-wide problems.
[0008] What is desired is a technique that provides centralized advice management in a large-scale network of computers.
[0009] What is further desired is that such technique provides a management interface that can display relevant advisories of all computers in the network and deploy suggested actions to all relevant computers.
[0010] What is still further desired is that such management interface allows a system administrator to manage subscription of advice provider sites, monitor status of deployed actions and monitor status of computers in the network.
[0011] What is still further desired is that such technique can automatically apply the required management tasks to fix problems on susceptible machines before they occur.
SUMMARY
[0012] A system and method for centralized advice management of large-scale networks is provided, wherein a number of distributed clients run on registered computers, gathering advisories and report relevance to a central server. A system administrator may view the relevant messages through a management interface and deploy suggested actions to distributed clients where the actions are executed to apply the solutions of the advisories.
[0013] In the preferred embodiment of the invention, a centralized advice management system is disclosed, which includes a plurality of distributed clients, a central server, a central database, and a management interface. The distributed clients gather advisories from a plurality of advice provider sites and report relevance of advisories to the central server. A system administrator may view the details of relevant advisories and deploy the suggested actions to distributed clients of relevant computers, where the actions are executed to apply solutions provided by the advisories.
[0014] In another equally preferred embodiment, a centralized advice management system is disclosed, which includes a plurality of distributed clients, a mirror server, a central server, a central database, and a management interface.
[0015] In another equally preferred embodiment, a centralized advice management system having a distributed client is disclosed, in which the distributed client comprises various components performing functions such as gathering advisories, authenticating advisories, evaluating relevance of advisories, registering a computer to a central server, reporting relevance to the central server, listening messages from the central server, gathering deployed actions from the central server, and executing deployed actions.
[0016] In another equally preferred embodiment, a method for providing centralized advice management for large-scale computer networks is disclosed. The method comprises the steps of:
The distributed clients on the computers register to a central server; A system administrator subscribes registered computers to advice provider sites; The distributed clients gather advisories from subscribed advice provider sites; The distributed clients report relevance to the central server; The system administrator views relevant advisories using a management interface; The system administrator deploys actions suggested by the advisories to the distributed clients; and The distributed clients execute the deployed actions to apply the solutions of the advisories.
[0024] The method may further comprise a step to manage subscription of advice provider sites to the distributed clients. It may further comprise a step to monitor the status of deployed actions. Alternatively, it may further comprise a step to monitor the status of registered computers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a schematic block diagram illustrating a communications system for computed relevant messaging;
[0026] FIG. 2 is a block diagram illustrating a typical advice management system in large-scale computer networks according to the invention;
[0027] FIG. 3 is a block diagram illustrating another advice management system in large-scale networks according to the invention;
[0028] FIG. 4 is a block diagram illustrating the main functions of a distributed client according to the invention;
[0029] FIG. 5 is a block diagram illustrating the main functions of a management interface according to the invention;
[0030] FIG. 6 is a flow diagram illustrating a method 600 for providing centralized advice management according to the invention;
[0031] FIG. 6A is a flow diagram illustrating an additional step for the method 600 according to the invention;
[0032] FIG. 6B is a flow diagram illustrating another step for the method 600 according to the invention; and
[0033] FIG. 6C is a flow diagram illustrating another step for the method 600 according to the invention.
DETAILED DESCRIPTION
Centralized Advice Management System
[0034] FIG. 2 is a block diagram illustrating an advice management system in large-scale computer networks according to one preferred embodiment of the invention. The centralized advice management system comprises a plurality of distributed clients 201 - 203 ; a central server 222 , a central database 223 , and a management interface 224 .
[0035] A distributed client is installed on every machine to manage under the system. Each of the distributed clients accesses a plurality of advice provider sites 211 - 213 through the Internet 221 and receives a pool of advisories that specify known problematic conditions. The client also monitors the configuration and status of the computer on which it is installed to see if any of predefined conditions arises, and sends to the central server 222 a message when such a condition arises. The distributed client communicates with the central server 222 on a regular basis, according to several defined interactions, and may obtain messages from the central server 222 specifying actions that the distributed client needs to perform, modifying the computer. Ordinarily, the distributed client operates silently, without any direct intervention from the end user of the computer.
[0036] The central server 222 comprises a collection of interacting applications including a Web server, CGI-BIN applications, and a database server. The central server coordinates the relay of information to and from individual computers, the storage and retrieval of information about individual computers, and the presentation of information for the system administrator. Ordinarily, the central server components operate silently, without any direct intervention from the administrator. In the moderate-sized deployments, the server processes are hosted by a single server. In the large-scale deployments, it may be useful to segment the server into processes running on separate servers, or to separate the network into several administrative sub-domains.
[0037] The central database 223 stores data about individual computers, about advisories that are actively being monitored, and about the history and action status. The central server's interactions primarily affect this database, which typically is a standard Microsoft product (based on the MSDE or SQL Server database engine).
[0038] The management interface 224 is an application that constitutes the only visible part of the management system in ordinary operation. It gives the system administrator an overview of the status of the computers in the network, identifying which, if any, of them might exhibit a certain problem or condition, and mandating that those computers, or a subset or them, take actions to correct the situation. The management interface 224 can run on any machine with network access to the central server 222 .
[0039] FIG. 3 is a block diagram illustrating an advice management system in large-scale networks of computers according to another preferred embodiment of the invention. The system includes a plurality of distributed clients 301 - 303 , a mirror server 304 , a central server 322 , a central database 323 , and a management interface 324 .
[0040] A distributed client is installed on every machine to manage under the system of the invention. Each of the distributed clients 301 - 303 accesses the mirror server 304 to gathering advice messages. The distributed client also monitors the configuration and status of the computer on which it is installed to see if any of the predefined conditions arises, and sends the central server 322 a message when such a condition arises. The distributed client communicates with the central server 322 on a regular basis, according to several defined interactions, and may obtain messages from the central server 322 specifying actions that the distributed client needs to perform to modify the computer. Ordinarily, the distributed client operates silently, without any direct intervention from the computer end user.
[0041] The mirror server 304 gathers advice messages from a plurality of advice provider sites 311 - 313 through the Internet 321 and receives a pool of advisories that specify known problematic conditions.
[0042] The central server 322 is a collection of interacting applications including a Web server, CGI-BIN applications, and database server. The central server coordinates the relay of information to and from individual computers, the storage and retrieval of information about individual computers, and the presentation of information for the system administrator.
[0043] The central database 323 stores data about individual computers, about advisories that are actively being monitored, and about the history and action status. The central server's interactions primarily affect this database, which typically is a standard Microsoft product (based on the MSDE or SQL Server database engine).
[0044] The management interface 324 is an application that constitutes the only visible part of the management system in ordinary operation. It is basically a management interface that gives the system administrator an overview of the status of the computers in the network, identifying which, if any, of them might exhibit a certain problem or condition, and mandating that those computers, or a subset or them, take actions to correct the situation.
The Distributed Client
[0045] The distributed client is installed on every machine managed under the advice management system. It is responsible for gathering advisories, studying the configuration of the machine on which it is running, and determining whether any of the advisories is relevant to that computer's configuration. The distributed client communicates relevance status to the central server and executes actions mandated from the management interface. Yet in spite of its power and sophistication, the distributed client is typically a small application, for example, approximately 2MB, intended to place an imperceptible load on managed computers, to use few network resources, to be secure and reliable, and to require essentially no management, e.g., certainly no end-user or on-site management.
[0046] The distributed client has eight distinguishable functions in the advice management system according to the invention. These functions are summarized in Table 1.
[0000]
TABLE 1
Functions of Distributed Client
Gather
Gather advisories from advice provider sites.
Authenticate
Verify message authenticity.
Evaluate
Check advisories against computer configuration for
relevance.
Register
Identify computer to central server.
Report
Report computer relevance event to central server.
Listen
Listen for messages from central server.
Gather actions
Gather action requests from central server.
Act
Execute action to change computer configuration.
[0047] FIG. 4 is a block diagram illustrating the main functions of a distributed client 400 according to another preferred embodiment of the invention. The functions include: gather advisories 401 , authenticate advisories 402 , evaluate relevance 403 , register 404 , report 405 , listen 406 , gather actions 407 , and perform actions 408 .
Gather Advisories 401
[0048] The system administrator uses the management interface to subscribe computers in the organization to various advice provider sites. It is the job of the distributed client to connect to the sites periodically and synchronize its local advice content with the content at those sites. To do so, the distributed client looks in each site's masthead file. The masthead files are kept on the computer in the folder in which the distributed client is installed. From the masthead file, the distributed client extracts the URL for the location from which content is served. It then uses HTTP commands to obtain any new advice content.
Authenticate Messages 402
[0049] The distributed client checks that the advice content is authentic, i.e. digitally signed by the true owner of the advice provider site.
Evaluate Relevance 403
[0050] The distributed client parses the advisories and learns what aspects of the computer configuration need to be evaluated to determine the relevance of those advisories. Then the distributed client scans the computer configuration to determine whether the actual configuration matches the relevance clause. It is important to note that this scanning takes place periodically, so that as the system configuration changes, the result of relevance evaluation can change as well.
Register 404
[0051] The computer running the distributed client needs not be restricted to be always on or to be in one place, or even within one virtual LAN. To accommodate such dynamic behavior, the management system needs the distributed client to identify itself to the central server when it is running and ready to communicate. This process is called registration. The management system assigns the distributed client a unique computer ID to identify itself in communications.
Report 405
[0052] When the distributed client detects that some advice has become relevant, it reports to the central server that a relevance event has occurred. It identifies the advice that became relevant along with its own computer ID.
Listen 406
[0053] The distributed client listens to the messages sent to it from the central server (by default on port 6603 ). These messages can contain either the computer ID from the registration process or certain process requests, such as a request to “gather actions now,” as described below.
Gather Actions 407
[0054] In response to receiving information indicating a relevance event from the distributed client, the system administrator sees a recommended action at the management interface. If the administrator decides to propagate the action, action requests are placed at the action site. Distributed clients gather action requests from the action site on a periodic basis, and sometimes, in response to prompts from the central server, can also gather requests outside the usual schedule.
Perform Actions 408
[0055] Upon receiving an authenticated action request, the distributed client performs the requested action.
[0056] Note that the distributed client goes beyond the consumer procedure to include the steps of registration, reporting, listening, and gathering actions. These reflect the needs and desires of system administrators in the enterprise setting.
The Management Interface
[0057] FIG. 5 is a block diagram illustrating the main functions of a management interface 500 according to another preferred embodiment of the invention. The management interface 500 is the visible component of the management system, used by the system administrator to maintain the computers throughout the enterprise. The main functions include: manage subscriptions 501 , display advice messages 502 , deploy actions 503 , monitor actions 504 , and monitor computer status 505 .
Manage Subscriptions 501
[0058] The advice management system accesses advice content that has been created by a content provider outside the enterprise, for example a hardware or software supplies, and brings it from the advice provider site into the enterprise. The advice management system may subscribe to some predefined sites during initial setup. For access to any other advice provider sites besides those that are set up automatically, a system administrator has to initiate subscriptions to those sites.
[0059] There are presently two ways to initiate a subscription to an advice provider site. The first way is to provide, through advisories delivered from already subscribed sites, recommendations of enterprise advice provider sites appropriate to the computers in the enterprise. The system administrator can then simply double-click the appropriate action link in the advice message body, and the subscription is to be initiated.
[0060] The other way to initiate a subscription requires more conceptual understanding. In general, initiating a subscription requires that a masthead file for that advice provider site be obtained from the intended content provider, and that the file be appropriately announced to the management interface. As with the central server masthead file, the masthead file for the advice provider site contains information about the URL of the server and the frequency of the site operations and it is to be digitally signed. However, unlike the central server masthead file, the masthead file is signed not by the enterprise but rather by the content provider organization.
[0061] If the system administrator knows of an advice provider site that offers content for the distributed client and wants to subscribe the management system to use that content, he can obtain the masthead file through a Web browser download. There is generally a Web page, at a well-known Web site or at the content provider's Web site, containing a hyperlink to the masthead file. By double-clicking the link, the masthead file is downloaded from the site to the computer running the Web browser.
[0062] The administrator is now ready to initiate the subscription using the management interface. The administrator then selects to which computers in the enterprise he wants to subscribe as the advice provider site. He may subscribe all distributed clients to the site, or a subset based on machine characteristics. He may select a frequency for the distributed clients to check in with the advice provider site and gather new advisories, which typically is daily synchronization, but other options are also available.
[0063] The subscription of distributed clients to advice provider sites can be modified through the management interface along with the advice gathering frequency. If a subscription is not useful, the system administrator may also cancel it by removing the advice provider site from the list of those subscribed to.
Display Advisories 502
[0064] When advisories become relevant somewhere on the network, the management interface can be used to view summary information about these messages. The summary information may include: (1) The advice name and numeric advice ID, both assigned to the advice message by the advice author; (2) The advice provider site from which the advice originated; and (3) The number of computers in the network to which this message is relevant.
[0065] The administrator may also look at the detailed information of a message using the management interface, which typically includes the list of relevant computers, an English-language explanation of the problem and an action providing an automatically solution.
Deploy Actions 503
[0066] When the administrator chooses to take a proposed action, he is given several options concerning its deployment which includes: target of action, action message, schedule of action, and execution control.
[0067] The target of action specifies the computers on which the action is to be deployed. The administrator may choose to deploy to all computers on the enterprise network, or all relevant computers, or manually selected computers. The action message requires an active user present when the action is run, to alert the user with a specified message, and to offer certain interactive features on the message display. The user may be able to look at the details of the proposed action and may cancel the proposed action.
[0068] The schedule of action allows the administrator to control when the deployed action runs on the targeted computers. The administrator may also specify an expiration time to impose a limitation on the lifetime of the action.
[0069] The execution control allows the administrator to control status of the action after invocation, retry of actions and certain post-action tasks. Once the administrator specifies these options, he enters the signing password to deploy the action.
Monitor Actions 504
[0070] After actions are scheduled, the central server attempts to signal individual computers that actions are waiting for them. Ideally, the distributed client gathers the action information from the action server and carries it out. In reality, some computers may be powered off and others may be mobile at the time of the signal, so at least some actions may not be executed immediately.
[0071] The management interface can be used to observe the status of deployed actions, whether pending, running, completed successfully or failed. The administrator can also view detailed information of the deployed actions such as the various options he specifies when the action is deployed. He can also stop a previously deployed action that has not yet finished running.
Monitor Computer Status 505
[0072] Although the advice management system is typically deployed as a mass preventive maintenance tool, it also has several features that allow for analysis and display of computer configuration information. In effect, the management interface can query computers in the enterprise network about a very large range of characteristics as configured by the administrator, and get real-time responses about those selected characteristics across all machines in the domain. The administrator can use relevance language to write expressions that can name a rather rich collection of properties of the software and hardware on the machine, and he can direct computers in the enterprise network to evaluate those expressions and return the resulting value.
[0073] The following example demonstrates that an “OS” computer property is actually generated by the relevance clause:
[0074] Name of operating system & “ ” & release of operating system & “ ” & build number of operating system as string.
[0075] It means that this property is actually a concatenation of three strings of information produced by suitable relevance expressions and separated by spaces.
[0076] The administrator can specify that new computer properties be added to the central database by specifying a name for the new property and entering the appropriate relevance clause, yielding an expression that each distributed client is then routinely evaluated. This may be very useful because it can access not only hardware characteristics but also registry entries and even data in specific files on the end-user computer.
[0077] After the new property is added, the distributed clients in the domain automatically compute the value of the corresponding relevance expression and return it to the central database.
[0078] The management interface can access a list of all the computers on the network. For each specific computer, the administrator may view retrieved properties, as well as information of subscription, relevance, relevant history, or action. The subscription information includes the advice provider sites to which the computer has subscribed. The relevant information includes a listing of advice messages that are currently relevant to the computer. The relevant history information includes a listing of all advice messages that have ever been relevant to the computer. The action information includes a listing of all actions that have ever been deployed to the computer.
[0079] FIG. 6 is a flow diagram illustrating a communication method 600 for providing centralized advice management of large-scale computer networks according to one embodiment of the invention. A typical implementation of the method comprises the steps of:
Step 601 : The distributed client running on each computer registers to the central server; Step 602 : The administrator subscribes the computers to a plurality of advice provider sites using the management interface; Step 603 : The distributed client running on each computer gathers advisories from advice provider sites; Step 604 : The distributed client running on each computer reports relevant advisories to the central server; Step 605 : The administrator views details of relevant messages; Step 606 : The administrator deploys the actions to the distributed clients which are relevant to the advice; and Step 607 : The distributed client receiving the actions performs the action to follow the advice. In another equally preferred embodiment, the method further comprises a step as showing in FIG. 6A : Step 620 : The administrator monitors the status of actions deployed to each computer.
[0089] In another equally preferred embodiment, the method further comprises a step as showing in FIG. 6B :
Step 640 : The administrator monitors the status of each computer. In another equally preferred embodiment, the method further comprises a step as showing in FIG. 6A : Step 620 : The administrator manages the subscription of advice provider sites to each of the computers in the network.
Client/Server Communications
[0093] There are several modes of communication between the distributed client and various servers such as the advice provider servers, the mirror server, the registration server, the reporting server, and the action server.
[0094] The advice provider servers are Web servers offering advice provider site subscriptions. They can be either local to the enterprise network or external to the network provided the direct external Web access is allowed.
[0095] In many enterprises, direct Web access is not available. Instead, a proxy server is used. In many cases, the proxy requires password-level authentication. For such enterprises, the embodiment of the system requires installing and running a mirror server. This also provides bandwidth management advantages.
[0096] The registration server is a component of the central server, which processes the registration requests from distributed clients and the server-to-client communication requests from other components of the central server. Reporting server is also a component of the central server, which processes reports of relevance events from individual computers and passes them on to the central database.
[0097] The action server is also a component of the central server, which receives action requests from the management interface and serves them up to individual distributed clients.
[0098] Although these components are described separately here, they are often physically hosted on one machine. However, it is worth keeping in mind that the system can be easily reconfigured so that, for example, the mirror server, the reporting server, and the action servers are on their own server box. The ability to decompose the system in this way can be an important feature for scalability in terms of both network bandwidth use and the number of supported computers within a deployment, and can also be useful for administrative segmentation.
[0099] For the advice provider site URLs, the distributed client looks in the masthead files located in its install folder. The other servers are all reached through URLs recorded in the central server masthead file, located in the registry. These masthead files are all under the control of the management interface.
[0100] The specific modes of communication between the distributed client and these servers include advice gather traffic, registration traffic, reporting traffic and action traffic.
[0101] When mirroring is disabled, the distributed client uses HTTP to access each advice provider server directly. Mirroring involves first a request for a directory listing that tells the distributed client what content is available at the site; the distributed client requests whatever content is new, and the advice provider server sends a single advice digest containing all requested content. The typical size of such a message is no more than about 2 kilobytes per advice.
[0102] When mirroring is enabled, the distributed client uses HTTP to access the mirror server directly, making a request for the content that would have been delivered by a (hypothetical) direct access over the Internet to the specific advice provider site. If the mirror server is internal to the LAN, this saves on Internet access charges and offers what is considered improved security. In a network in which computers are not allowed to access the Internet directly without password authorization, mirroring must be enabled.
[0103] The distributed client uses HTTP to send to the registration server the distributed client's previous computer ID and ancillary information. The distributed client sends its previous computer ID and ancillary information to the registration server via HTTP. The registration server responds by sending a UDP message to the distributed client (by default to port 6603 ), indicating the distributed client's new computer ID and ancillary information.
[0104] The distributed client sends the reporting server a simple text file using an HTTP POST operation. The text file contains, in a transparent format, a list of all changes in relevance status on that computer since the previous relevance evaluation.
[0105] The distributed client uses HTTP requests containing the computer ID to gather action requests addressed specifically to it from the advice provider server.
[0106] Note that because the client/server traffic is directed via URLs, it is possible to reconfigure any or all of the HTTP requests to become HTTPS requests, or to reconfigure the URL, so that HTTP requests use port numbers other than the default ports 80 and 81 . This may provide extra security benefits. In the system, the distributed client initiates most of the communications. It maintains a schedule that is controlled by parameters in the masthead files. For example, an advice provider site masthead file contains the recommended frequency of gathering for that site, and the central server masthead file contains the recommended frequency for registration, and for gathering of actions.
[0107] However, there are exceptions. The central server can send, via the reporting server, a UDP message to a specific distributed client telling the distributed client to gather actions immediately or gather advisories immediately. Moreover, the management interface allows the system administrator to override advice provider site subscription policies of the site publisher, for example increasing or reducing the frequency of gathering or constraining gathers to take place at only certain times of day.
[0108] When if there is no network connection, the distributed client simply performs another evaluation loop, checking for the relevance of any advice message in the current advice pool on that computer. At the end of that loop, if any advisories are relevant at that time, it then attempts to communicate relevance back to the reporting server.
Message Authentication
[0109] The management system authenticates certain messages using secure public-key infrastructure (PKI) signature mechanisms based on digital encryption technology. In fact, PKI technology is deployed to protect the integrity of both advice content and action content.
[0110] The site author signs the communications from an advice provider site to a distributed client digitally. The signature must match the site's masthead file, which was placed in the distributed client install folder when the system administrator subscribed the distributed client to that site.
[0111] The action server signs every message digitally. Thus if the signature validation fails on the distributed client side, the message is ignored and discarded. This signature must match the action site's masthead file, which was placed in the Windows registry when the distributed client was installed.
[0112] To propagate any action request from the central server to the distributed client, the person operating the management interface must enter the signing password. This requirement is designed to prevent unauthorized users from using the management interface to propagate inappropriate actions.
[0113] Because of the important role played by the PKI and the signing password, it is very important to guard the public/private key pair and the password well, revealing them only to specially trusted people.
Action Capabilities
[0114] The distributed client performs actions on the computer at the request of the management interface operator. These actions can address process management issues, such as changing the advice provider sites to which the computer is subscribed, or system management tasks, such as changing the clock on the computer to agree with the central server clock, or they can involve downloading and installing a file. Such actions are specified in an Action Scripting Language, which enables the specification of actions that affect the computer as follows:
Files: Delete, move, or copy specific files; Registry: Set or delete registry entries; Commands: Run DOS commands or Visual Basic or JavaScript commands; and DLLs: Delete, add, or commit various DLL modules. Actions that offer management of the process can also be specified: Advice Ops: Delete, close, or restore an advice message; Site Ops: Subscribe or unsubscribe to an advice provider site; Gather Ops: Change the gathering schedule or force an immediate gathering; and Evaluation: Force an immediate relevance evaluation of advisories. As a scripting language, this language contains flow control facilities that enable conditional execution: Continue if {condition}: Continue if the condition is true. Pause while {condition}: Do not continue until the condition is false. The Action Scripting Language further offers a variety of user interface tools that enable the distributed client to interact with the user—for example, browseto, which opens a browser window at a specified URL. In many embodiments of the advice management system, system administrators do not want to involve the user in the process, although it is easy to imagine situations in which such involvement would be valuable, particularly because it can be pinpoint-directed to computers having specific attributes.
[0128] In addition, the action can be relevance-mediated, so that they are only applied on a certain computer if they are still relevant at the moment they are being considered for execution. This avoids the problem of fixing a problem that is no longer present on the machine at the time the action request to fix the problem is received.
[0129] The action can be scheduled, so that they are only applied on a certain computer at a certain time of day, local time. This makes it possible to run actions after everyone has gone home for the night, in whatever time zone “night” might be.
[0130] In short, the distributed client offers a powerful set of actions within a sensible context of scheduling and attention to continued relevance.
Network Traffic Considerations
[0131] The embodiment described above has been designed to be a lightweight client/server process which is highly responsive, giving the system administrator an up-to-the-minute view of the state of the network, while at the same time keeping host computer performance high and network traffic low. To understand how this is accomplished, the following factors must be considered.
[0132] First, the advice management system reacts only to changes in state of the computer. Every effort is made to report only how relevance is different now than it was in the previous evaluation loop. Because very few relevance events occur every day, most of the time the distributed client is not reporting anything to the server. In fact, if there are no relevance events in a specific day, the only interactions are likely to be a registration, hourly action gathers, and one or two advice gathers per subscribed site. The total network traffic associated with the registration and the action gathers may be less than a few kilobytes on that day.
[0133] Second, the advice gathering process likewise reacts only to changes in state of the advice provider site, so that every effort is made to report only new advisories that were not previously downloaded by the distributed client. If there are no new messages on a given day, the total network traffic associated with the advice gathering may be less than a few kilobytes on that day.
[0134] Third, the method described overhead, i.e. total bandwidth consumption when there are no issues that need to be dealt with, is absolutely minimal and beneath the radar even for computers operating on intermittent dial-up connections.
[0135] Fourth, when there are issues to be dealt with, the method described above is likewise efficient. Individual messages are very compact: an advice message is typically less than 2 kilobytes in size, a registration request less than 200 bytes, a registration response less than 400 bytes, and a relevance report less than 2 kilobytes. In addition, data compression is used where possible in the advice provider server, including both standard text compression algorithms and client-side include procedures.
[0136] Finally, in large organizations, where saving percentages of network bandwidth leads to appreciable benefits, it would be worth the extra effort to use mirroring to avoid the need for each distributed client to reach the public Internet and download all of its content over the Internet.
[0137] In summary, in most enterprise environments, the bandwidth use per distributed client by the method described above is negligible compared to existing bandwidth use for processes, such as e-mail, Web surfing, and Web-based data entry.
Security Considerations
[0138] Because the distributed client can change the configuration of the computer on which it is running, including removing and updating files, its security must be considered.
[0139] The distributed client reports only to the reporting server and honors only action requests from the action server. It is not easy to tamper with the URLs naming these servers because they are contained in digitally signed masthead files that are essentially forgery-proof. Furthermore, the content from these servers is digitally signed and thus is also essentially forgery-proof. These factors suggest that IP spoofing or DNS spoofing attacks are unlikely to be effective. Corporate networks with firewalls and other security measures are in all likelihood be far more secure.
[0140] Although it seems unnecessary, increasing the security of the communication process between the distributed clients and the central server is possible through several well-understood precautions that we only sketch here.
[0141] This invention comprehends two strategies. The first strategy is the closing off public access. This prevents any direct interactions between the distributed client and the public Internet. The system administrator has several choices. He can operate a mirror server, so that no individual distributed client needs to access to the public Internet. Alternatively, he can rewrite the URLs in the central server masthead file and the advice provider site masthead files so that they use port numbers which are not well known, or he can block firewall ports that correspond to the newly assigned set of distributed client port numbers.
[0142] The second strategy is secure public access. This strategy allows the use of the public Internet but makes access more secure by guaranteeing, not only the authenticity of the documents being delivered over the Internet, but also the privacy and security of the actual connection. The system administrator can rewrite the URLs in the central server masthead file to use HTTPS rather than HTTP. Then all transactions between the distributed clients and the central server are digitally encrypted and so are protected in the same way that modern e-commerce transactions are protected.
[0143] Although the invention is described herein with reference to the preferred embodiment, one skilled in the art will readily appreciate that other applications may be substituted for those set forth herein without departing from the spirit and scope of the present invention.
[0144] Accordingly, the invention should only be limited by the claims included below. | An apparatus and method for centralized policy management of large-scale networks ( 221 ) of computational devices is disclosed. The apparatus includes a number of distributed clients ( 400 ) run on registered computers ( 201 - 203 ), gathering policy advisories ( 401 ) and reporting ( 405 ) relevance ( 403 ) to a system administrator ( 224 ). The system administrator may view the relevant messages ( 505 ) through a management interface ( 500 ) and deploy suggested actions to distributed clients ( 503 ), where the actions are executed to apply the solutions of the advisories ( 408 ). | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
In general, this particular invention relates to the forging of metal articles having predetermined shapes. More specifically, however, the present invention relates to a novel and improved method of forging preselected recessed configurations in a body member by forging a slave preform and the body member, and quenching such slave preform after the forging to facilitate removal thereof.
2. Brief Description of the Prior Art
Present day forging methods are unable to satisfactorily forge either internally or externally constructed generally radial recesses on members, such as the type found on inner bearing cone members, or other conventional inner and outer bearing race members. It has been determined that the difficulty encountered in the formation of such recesses was due to conventional forging techniques. In particular, the external or internal recesses would lock on the die wall or core rod wall, respectively. Various techniques exist, however, in industry for forming such recesses. One standard approach for use in the formation of such bearing cones and races includes conventional machining steps of appropriate metal blanks so as to correspondingly form a continuously smooth and recessed surface. While this particular practice has been followed, it nevertheless prevents several significant shortcomings. For instance, one substantial drawback associated with machining is that it inevitably results in additional costs. These cost increases include not only that which results from high scrap rates, but also the additional heat treatment necessary following machining in order to obtain the necessary case hardness and case depth.
Moreover, it should be pointed that the the field of forming bearing components is competitive and there is somewhat of a narrow or small profit margin associated with the production of such bearing elements. As a consequence thereof, it will, of course, be appreciated that even slight savings in cost render such bearing components more desirable from a cost standpoint.
From the preceding considerations, it is quite apparent that the formation of external or internal recesses on these bearing components, especially of the powdered metal type using the conventional machining approach, is complicated and are relatively higher in cost as well as require added time and labor.
For the reasons enumerated above, it is difficult and time-consuming to accurately form each bearing component. The prior art is absent a reliable and accurate technique enabling the formation of conventional bearing components without the noted drawbacks.
Additionally, the state of the art is absent not only processes enabling even more economical manufacture of large numbers of inner or outer bearing race elements having continuously smooth recessed surfaces, but also enabling the surfaces of case hardened powdered metal bearing parts to be formed in a manner without impairing the protection provided by case hardening.
SUMMARY OF THE INVENTION
Accordingly it is an object of this invention to overcome the heretofore noted prior art failings by being able to forge internal recessed configurations in a member, especially a body member for use in the construction of bearing components.
Briefly, in accordance with the principles of the present invention, there is disclosed a novel and improved method of forging preselected recessed surfaces in a member comprising the steps of adding a suitable lubricant material to at least a slave or primary preform member wherein the lubricant material is sufficient to prevent welding between the noted preforms during the forging operation. Such invention envisions joining the slave preform to the primary body preform member followed by forging the joined together preforms such that the primary preform member is deformed to an extent generally complementary to a portion of the configuration of the slave preform, such that the forged primary preform has formed therein a shaped recess generally complementary to at least a portion of the slave preform. The forged slave and primary preforms are then quenched. Thereafter, the method contemplates removing the slave from the recess of the primary preform.
In a preferred embodiment, the foregoing method envisions use of powder metal primary and slave preform members wherein the slave preform is made of a quench crackable material and the forged slave and primary preforms are quenched to thereby enable the slave preform to quench crack. The quench cracking thereby facilitates easy removal from the formed recess in the primary preform.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become readily apparent upon reading a detailed description thereof when viewed in conjunction with the accompanying drawings wherein like reference numerals indicate like structure throughout the several views.
FIG. 1A is a partial cross-sectional view of a generally annular slave preform member embodying the principles of the present invention;
FIG. 1B is a partial cross-sectional view of a generally annular primary preform member;
FIG. 1C is a view depicting the slave and primary preform members of FIGS. 1A and 1B, respectively, in an assembled condition prior to forging;
FIG. 1D is a partial cross-sectional view depicting the relationship of the primary and slave preform members after the forging operation, whereby the primary preform member is deformed about the slave preform member, to form a generally vertical and external recess;
FIG. 1E is a partial cross-sectional view illustrating the cracking of the slave preform member during a quenching operation;
FIG. 1F is a partial cross-sectional view representing the forged primary preformed member without the slave preform;
FIG. 1G is a perspective view illustrating the fact that the forged primary preform has been formed into an inner bearing race member by virtue of the foregoing sequential steps shown in FIGS. 1A through 1F;
FIG. 2A is a partial cross-sectional view of a generally annular slave preform made in accordance with the principles of the present invention;
FIG. 2B illustrates a partial cross-sectional view of a generally annular primary preform member used in forming an outer bearing race member;
FIG. 2C is a view depicting the slave and primary preform members of FIGS. 2A and 2B, respectively, in an assembled position prior to a forging operation;
FIG. 2D is a partial cross-sectional view illustrating the arrangements of the slave and primary preform members after a forging operation whereby the primary preform member is deformed about the slave preform to form an internal and generally vertical recess;
FIG. 2E is a partial cross-sectional view representing the cracking of the slave preform member during a quenching operation;
FIG. 2F represents a partial cross-sectional view showing the forged primary preform member without the slave preform member;
FIG. 2G is a perspective view illustrating the fact that the forged primary preform has been formed into an outer bearing race member formed generally by virtue of the foregoing sequential steps shown in FIGS. 2A through 2F;
FIGS. 3, 4 and 5 represent forged gear members having a recessed area formed from a corresponding slave preform being of a shape and dimension such that it can form the noted recessed areas;
FIG. 6A is a cross-sectional view depicting a generally annular slave preform member in engagement with a primary preform member prior to a forging operation; and
FIG. 6B illustrates the cooperation between the slave and primary preform members after the forging operation whereby the primary preform member has been deformed to an extent determined by the slave preform member.
DETAILED DESCRIPTION
Although the succeeding description will be primarily directed to the forging of conventional inner and outer bearing race members, as well as cone-shaped bearing members, it will be understood that other types of articles may be suitably forged, particularly whenever it is desired to have the forged articles with an internal or external recess. As will be pointed out below, the forged bearing members with preselected generally axial recesses are to be made from conventional powdered metallurgical materials. It is contemplated by this invention that the formation of the axial recess be accomplished by forging together an appropriately sized and configured primary preform member 10 with an appropriately sized and configured slave preform member 12. The particular significance of such slave preform will be afterwards more completely described.
In particular, reference is made to FIGS. 1A-1F. As shown, in schematic form, there is illustrated a preferred sequence of operational steps which collectively serve to form inner bearing race member 14 (FIG. 1G) having an externally oriented recess 16 which will form a bearing raceway. FIG. 1A denotes a portion of slave preform 12 and insofar as this embodiment is directed to fabrication of cylindrical inner bearing race member 14 (FIG. 1G), it will be appreciated that slave preform 12 takes the configuration of a generally annular ring. The ring-shaped slave preform 12, as will be described, is for purposes of facilitating formation of the inner bearing race member 14 with a continuously smooth and circumferential raceway 16 in a single forging step. The slave preform 12, although not actually shown in this particular embodiment, can be formed with a plurality of internal or external grooves, such as of the kind depicted in FIG. 2A. The grooves can be suitably formed on the radially inner or outer surfaces of the slave preform on the surface opposite that which is complementary to the surface to be formed on the primary preform. The grooves advantageously facilitate quench cracking of the slave preform 12 which thereby enhances subsequent removal of the slave preform after forging.
Slave preform 12 is a briquetted powdered metal component. While the present invention envisions that several materials other than powdered metal can be used in fabrication of such a slave preform, it has been determined that powdered metal is preferred. In one embodiment, the invention envisions application of an iron powder having a relatively high amount of carbon added thereto. Alternatively, there need not be any carbon added. Typically, whatever carbon is added, however, generally takes the form of graphite. For instance, the amount of carbon, by weight, may range from about 0.0 percent to relatively high amounts in the order of 1.0 percent by weight. Whenever relatively high amounts of carbon are added, such as above 0. percent by weight, such facilitates the quench cracking of the slave preform 12.
The iron powder and carbon, in the form of graphite, are suitably blended and then pressed into a low-density, semi-finished slave preform 12 or briquette. If, for instance, the iron powder has 0.0 percent carbon, the briquetted slave preform 12 should be sintered, after briquetting, in a decarburizing atmosphere. On the other hand, whenever 1.0 percent carbon, by weight, is added to the iron powder, the briquetted slave preform 12 should be sintered in a carburizing atmosphere. The sequential briquetting and sintering operations, above noted, are known procedures performed by any suitable and conventional apparatus on powder metal parts. Since such operations do not, per se, form an aspect of this invention, a detailed description thereof will be dispensed with. It will be mentioned, however, that the reason the 0.0 percent carbon slave briquette is sintered in a decarburizing atmosphere, whereas the 1.0 percent carbon is sintered in a carburizing atmosphere is because decarburizing atmosphere provides for better machinability, while the carburizing atmosphere will facilitate quench cracking.
Generally, whenever in excess of 0. percent carbon, by weight, is found in the briquetted slave preform 12, such will be sintered in a protective atmosphere. It also being understood that the higher the amount of carbon, the more extensive quench cracking occurs, thereby enhancing separation of the quenched slave preform.
Apart from the above characteristics, the slave preform 12 is to have the physical geometry to be easily cracked in response to quenching. In addition, it is important that the physical geometry be such as to provide the strength necessary for the slave preform to resist failure resulting from any of the conditions occuring during the conventional forging steps contemplated by the present invention.
Towards the particular end of facilitating quench cracking of the slave preform 12, it will be appreciated, of course, that the powder metal material and carbon content are appropriately selected in accord with known techniques not forming a part of the invention. With the slave preform 12 quench cracked, it can be more easily removed or separated from the primary preform 10.
Primary preform member 10 forms the inner bearing component 14. FIGS. 1A to 1F, as noted, clearly disclose the steps followed in practice of the invention for use in formation of an inner bearing race member 14 with external recess or raceway 16. Primary preform 10 is also made of a suitable metal, preferably, powdered metal. The primary preform 10 is case hardened, in a manner to be described, to provide for a long operational life and to an extent to prevent the primary preform 10 from cracking when it is quenched with the slave preform 12. It is also envisioned that the exterior surface of primary preform 10 need not be case hardened. If such is the case, the primary preform is made of a metal which resists quench cracking whenever the slave preform is quenched in the manner to be described and the primary preform can be subsequently carburized. However, if powdered metal is to be used, case hardening is desirable. The powdered metal primary preform 10 should resist quench cracking, possess sufficient strength to avoid cracking or crumbling during forging, as well as facilitate the desired preselected deformation of the primary preform 10 to form the inner bearing member 14. Such powdered metal can be comprised of iron powder or a low alloy steel powder being the equivalent of the 1000 to 4600 wrought steel series, respectively. This type of powdered low alloy steel and the iron powder can have suitable amounts of carbon added thereto.
A blend of powdered metal and carbon is usable in the fabrication of the primary preform 10 and is suitably briquetted in a pressing step to a semi-finished product or preform having low density. The briquetting of the primary preform 10 is accomplished in standard fashion and such briquetting does not form an aspect of this invention.
Subsequent to the above operation, the briquetted powder metal preform 10 is subjected to known sintering and carburizing steps. The sintering and carburizing steps are performed in a known way to achieve, inter alia, a case hardened surface 22. It is evident that the conditions under which the known sintering-carburizing steps are performed are appropriately selected in accordance with known procedures to achieve the desired properties. A more detailed description of the sintering and carburizing steps are given below.
The foregoing is accomplished in a known sintering furnace having a known carburizing apparatus and treating conditions. An example of such a sinter-carburizing step, as contemplated for use, is generally described in U.S. Pat. No. 3,992,763, which is assigned to the assignee of the present invention. The above steps can, in known fashion, ensure attainment of a primary preform having the chemical and physical properties thought desirable for the bearing member 14.
For example, the case hardened surface 22 of bearing 14 is between about 0.85 percent to 0.95 percent carbon by weight, whereas the bearing core 24 could have between about 0.22 percent to 0.28 percent carbon by weight. The sinter-carburizing is performed until the case of the primary preform has the desired carbon level to produce about between 60 and 64 Rc. when quenched and attains the desired depth necessary for the purposes intended for the particular bearing member.
As best viewed in FIGS. 1B and 1C, the annular primary preform 10 is briquetted with an outwardly extending flange 26. Flange 26 not only supports the slave preform 12 prior to and during forging, but also forms a sidewall for the recess 16. The end portion 28 of the preform 10 is dimensioned to protrude from the slave preform such that, in conjunction with the slave preform 12, it will, whenever forged, be contacted and deformed. The end result of such deformation is perhaps best depicted in FIG. 1D. As observed, end portion 28 is deformed during forging to form the opposing sidewall of recess 16.
With reference to FIG. 1E, it is seen that slave preform 12 is disposed adjacent and in contact with flange 26 prior to the forging step. In practice of the invention, the slave preform 12 ordinarily has a slight press-fit with the primary preform 10.
Either or both of the preforms 10 and 12 can be suitably coated with an appropriate lubricant. This is done to prevent the adjoining surfaces of the preforms from adhering together. The lubricant tends to prevent the primary preform 10 and slave preform 12 from being welded or bonded together during the forging operation. Should such a welding action occur, however, the case hardened surface of the primary preform is detrimentally affected. Furthermore, removal of the slave preform 10 is complicated. It is, therefore, important that the kind of lubricant used prevent the above-described welding condition. It will be understood that impairment of the case hardened surface 22 on the primary preform 10 will not occur. In addition, separation of the slave preform 12 is facilitated.
Towards the foregoing end, the lubricant material is appropriately selected to possess properties which will effectuate the foregoing goal of preventing the welding of the slave and primary preforms during the forging operations. It being understood that the selection of lubricant materials is again made consistent with known engineering practice to ensure prevention of welding.
It has been determined that a water base, fine graphite suspension type lubricant works quite well.
In accordance with the invention, the assembled preforms 10 and 12 are suitably placed into the die of a known hot forging system, such as described in the aforementioned U.S. Pat. No. 3,992,763 and its related U.S. Pat. No. 4,002,471, which is also assigned to the Assignee of the present invention.
Both preforms 10 and 12 are further compacted during forging to a more dense state, wherein the deformed primary preform has its desired dimension. Mention is also made that both the primary and slave preforms 10 and 12, respectively, when forged in the hot-forge system are generally below the die or core rod surface. As mentioned above, previously attempted forging efforts to form generally axial recesses in forged members have been unsuccessful because of interference of the die surface or core rod.
After the forging step, both the primary and slave preforms 10 and 12 have had their cross-sectional area appropriately reduced and are then suitably removed from the forge die. Thereafter, both the preforms are subjected to the quenching step. As somewhat exaggerated for the purposes of illustration, FIG. 1E depicts the slave preform 12 in a cracked condition as a result of the quench cracking step.
The particular fluidic quenching medium, as well as the temperature of such medium and the prescribed time interval necessary to achieve the quench cracking is determined in accordance with sound engineering practice. Of course, the parameters of the quenching condition can be suitably varied. In this connection, the present invention contemplates the application of any suitable oil quenching medium, such as disclosed in the aforementioned U.S. Pat. Nos. 3,992,763 and 4,002,471.
However, the present invention envisages that the primary preform 10 be fabricated from a material and treated in a fashion to avoid having the forged primary preform member 10 quench cracked along with the slave preform. A powdered metal primary preform properly carburized during the sintering operation will not quench crack when forged and quenched.
After the slave preform 12 is quench cracked, it is removed from the formed primary preform 10. The removal step may be expeditiously and simply accomplished by any conventional approach. For instance, if the slave preform 12 has no carbon, it is removed by machining, whereas if relatively high amounts of carbon are present, the cracked slave preform can be removed by appropriate and conventional mechanical breaking techniques.
The quenching causes sufficient cracking which enables application of other suitable and conventional techniques which completely remove the cracked slave preform 12 from recess 16 formed in the resulting inner bearing member 14. The resulting recess 16 is completely ready for the purposes intended following a finish grind if surface finishes in the area of 0-50 microinches are required. Surface finishes of 125 microfinishes are easily obtainable with applicant's invention and applicant can obtain surface finishes as good as 60 microinches providing good lubrication procedures are followed with respect to the preforms. These other removal or separation techniques vary from machining, such as when virtually little cracking occurs, to mechanical breaking of the slave preform 12 by suitable implements when a significant quench crackable slave preform is used. In the later instance, the slave preform may be sufficiently cracked that it simply falls off to the bottom of the quenching bath. The foregoing list of separation techniques for slave preform 12 is for purposes of illustration and not limitation. Since lubricant is used, the case hardened surface 22 is not adversely affected by the slave preform 12, and the latter's extrication is facilitated.
It will be appreciated that by virtue of the foregoing sequence of steps utilizing the slave preform 12, only a single forging step is needed to form inner bearing member 14 having external axial recess 16.
In regard to the sequence of steps shown in FIGS. 2A through 2G, it will be appreciated that such depict the use of primary and slave preforms 10' and 12' for use in forming outer bearing member 30 with internal generally axial recess 32. It being understood that the primary difference between this embodiment and the earlier described embodiment is the fact that the slave and primary preforms 10' and 12' are used for the successful completion of an outer bearing race member 30 having an internal recess. The difference in the operational steps is, of course, the fact that the press-fit placement of the primary preform 10' is radially outwardly disposed with respect to the slave preform 12'. In the other embodiment, the slave preform was disposed exteriorly with respect to the primary preform. Slave preform 12' is supported by the outer annular flange 26' to maintain it in the desired position during forging. In this embodiment, grooves 34 function to even better effectuate the quench cracking of the slave preform 12'.
It will be understood that the formation steps for the slave and primary preforms are essentially the same as in the above embodiment. In addition, the materials for fabricating the preforms can be the same, as well as the forging, quenching and separating steps. Hence, a detailed description has been dispensed with.
Reference is now made to FIGS. 3, 4 and 5 where there are depicted powder metal gearing members 40, 50 and 60, each having a centrally formed opening and recessed area 42, 52 and 62, respectively. Recessed areas 42, 52 and 62 are formed during a suitable and conventional forging operation, such as in the noted hot-forge system, in which a correspondingly and complementary shaped slave preform (not shown) has been utilized to form such recesses. The foregoing examples of different recessed configurations demonstrate that the present invention contemplates that the slave preform can produce a wide variety of recesses on other than formed bearing members. As with the other described embodiments, it is desirable to have the slave preforms made of powdered metal material. In addition, of course, suitable lubricants coat either and, preferably, both of the preforms to avoid the welding or bonding together of such preforms whenever forged. Similarly, these slave preforms may have grooves or other indentations which will function to enhance the quench cracking.
Now referring to FIGS. 6A and 6B, there are only shown two operational steps in the formation of a cone bearing member 70. The steps for its formation are substantially the same as described earlier in connection with bearing members 14 and 30. The differences, of course, primarily relate to the fact that both slave and primary preforms 72 and 74, respectively, have been briquetted with different configurations. These configurations enable formation of cone bearing member 70. It will be seen that slave preform 72 has a suitable press-fit with the exterior tapered surface of the primary preform 74. The cone bearing preform 70 has its upper portion 76 formed with suitable dimension to ensure the formation of top flange member 78 during forging. As will be appreciated, the materials, the briquetting, sintering, carburizing, forging, quenching and separating steps, as well as lubricant, are appropriately selected to achieve the formation of the outer cone bearing.
The invention will be further described in connection with the following examples which are set forth for purposes of illustrating the present invention.
EXAMPLE 1
A slave preform is made of an appropriate iron powder material of the type utilized in the formation of powder metal parts. Added to the iron powder is a relatively high amount of carbon having 1.0 percent carbon, by weight. This carbon material is applied in the form of, for example, graphite. The blend of iron powder and carbon are briquetted at sufficient pressure to compress it into a semi-finished, low-density slave preform. The briquetting operation forms the annular shaped part having an inside diameter of about 3.30 inches and an outside diameter of about 3.53 inches, with a height of about 1.00 inches. Such dimension is sufficient to withstand failure during forging and enable formation of the recess on the forged primary preform, as well as facilitates quench cracking. The noted physical dimensions are such that it can be slightly press-fit onto the corresponding radially outer surface of the annular primary preform for purposes of effectuating formation of an external recess.
The primary preform is made of a powdered low alloy steel which is a powdered metal equivalent of the AISI 4600 wrought steel series. This preform has a carbon level in the range of 0.22 percent by weight. The foregoing materials are pressed or briquetted into a semi-final primary preform having a density of about 80 percent that of a fully dense part. The briquetted primary preform also has a generally annular configuration which has an inner diameter of 2.50 inches and an outer diameter of 3.30 inches and a height of 1.60 inches. In addition, the primary preform is briquetted with an annular flange adjacent one end such as shown in FIG. 1B to thereby receive the slave preform which is press-fit thereabout.
After completion of the briquetting operation, the preform is successively subjected to a combined sintering and carburizing process of the type described in said U.S. Pat. No. 3,992,763. In this process, the primary preform is simultaneously sintered and carburized in a sintering furnace equipped with the utilities and controls necessary to provide a carburizing atmosphere. In the sintering and carburizing process, the temperature is about 2050° F. endothermic carburizing gas is utilized at about 2700 ft 3 /hr. The sintering and carburizing operation is performed for a time interval of 45 min. with the sintering being performed at 2050° F. for about 25 minutes and the subsequent carburizing at 1700° F. for the remainder of the operation. As a result of the foregoing parameters being used, the surface is carburized and has 0.75-0.90 percent carbon by weight. The total carburized depth is approximately 0.080 inches. The remaining core of the primary preform has about 0.22 percent carbon, by weight.
Subsequent to the sintering and carburizing step, both the primary and slave preforms, respectively, are coated with lubricant. This prevents the preforms from being welded together during forging. The lubricant is a water base, fine graphite suspension.
Thereafter, the assembled preforms are suitably placed in a conventional hot-forge system. Under the hot-forge process, preferred by applicant, the operating temperature is about 1750° F. and the pressure applied to the assembled preforms is about 75 Tsi. As a result of the forging, both preforms have their cross-sectional areas further compressed such that the forged primary preform has the desired dimension and density.
After the forging, both the primary and slave preforms are quenched in an oil bath at approximately 1600° F. for a period of about 90 seconds. Under these conditions, the quench cracking of the slave preform is effectuated.
At the completion of the quenching, the cracked slave preform is easily removed from the forged inner bearing by any suitable mechanical breaking technique, such as by a sharp blow with a hammer or vibrator-type impact tool in the cracked areas.
EXAMPLE 2
In this example, the slave preform briquette is formed of iron powder material without carbon. As a result of the briquetting operation, the slave preform is formed. After the briquetting, it is sintered in a low carbon atmosphere as opposed to a carburizing atmosphere. This accomplishes a machinable material. The outside diameter of the preform is about 3.75 inches, the inner diameter is about 3.50 inches, and the height is about 1.00 inches. The physical dimensions of the slave preform are such as to enable it to be press-fit with the interior surface of the annular primary preform and to facilitate process handling as well as withstand forging.
The primary preform is briquetted, in the configuration shown in FIG. 2B, from the same low alloy steel powder as in example 1, but has 0.22 to 0.28 percent carbon by weight. The briquetted preform has an outer diameter of about 4.25 inches, an inner diameter of about 3.75 inches, and a height of about 1.60 inches. The noted sintering and carburizing process is performed. Such process case carburizes the exterior of the primary preform. In this sintering and carburizing process, the temperatures are the same as Example 1, 2050° F., endothermic carburizing gas is utilized in about 2700 ft 3 /hr. for a time period of about 45 minutes. As a result of such parameters being followed, there is produced a case carburized surface having 0.75-0.95 percent carbon by weight and a core having 0.25 percent carbon by weight.
After the sintering and carburizing step, the preforms coated with graphite lubricant and then assembled with the slave preform disposed radially inwardly relative to the primary preform much as in the manner depicted in FIG. 2C. Subsequent to the assembling step, the preforms are to be forged. The forging step taken on the assembled preforms of FIG. 2C results in the formation shown in FIG. 2D. The forging is accomplished in a known sinta-forge system.
In this sinta-forge process, the operating temperature is about 1750° F. and the pressure is about 75 Tsi.
After the forging, both the primary and slave preforms are quenched in an oil bath at 1600° F. for a period of about 90 seconds. Under these conditions, the slave preform can be machined off and the surfaces of the primary preform are carburized.
At the completion of the quenching, the cracked slave preform is easily removed from the forged inner bearing by any suitable machining technique.
EXAMPLE 3
In this example, the slave preform briquette is formed of powder material with 0.65 percent carbon by weight. After the briquetting, it is sintered in a carburizing atmosphere. The outer diameter is about 4.50 inches, the inner diameter about 4.25 inches, and the height about 1.00 inches. The slave preform is slightly press-fit interiorly of the annular primary preform.
The primary preform is briquetted, in the configuration shown in FIG. 2B, from low allow steel powder being the powdered equivalent of 4600 series, and has 0.25 percent carbon by weight. The briquetted preform has an outer diameter of about 4.75 inches, an inner diameter of about 1.50 inches, and a thickness of about 1.00 inches. The noted sintering and carburizing process is performed which case carburizes the exterior of the primary preform. The sintering and carburizing process is performed as in Example 1, the sintering temperature is about 2050° F., endothermic carburizing gas is utilized in about 2700 ft 3 /hr. for a time period of about 45 minutes. The result of such parameters being followed produces a case carburized surface with a surface carbon of about 0.85 percent carbon, and a core having 0.28 percent carbon.
After the foregoing, graphite lubricant is applied to coat both the preforms. The coated preforms are then assembled together in the fashion shown in FIG. 2C. The assembled preforms are forged in the hot-forge system wherein the temperature is about 1750° F. and pressure is about 75 Tsi.
At the conclusion of the above, the forged preforms are quenched in an oil bath at approximately 1600° F. for a time interval of 90 seconds. Under these conditions, quench cracking of the slave preform results. Thereafter, the quench cracked preform is removed from the outer bearing member by a sharp blow with a hammer or a vibrator-type impact tool in the cracked areas.
While the invention has been described in connection with the preferred embodiment, it is not intended to limit the invention to the particular form set forth above, but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. For example, an alternative could be a final product having a through hardened structure rather than a case (hard)/core (soft) structure. This would be accomplished by selecting a higher carbon content in the powder used for the fabrication of the primary preform and sintering the primary preform consistent with the aforementioned U.S. Pat. No. 4,002,471. Further, by using a 4600 type steel alloy powder with approximately 0.60-0.70 carbon by weight, sintering in a controlled atmosphere to maintain a combined carbon of 0.60-0.70 throughout said sintered preform, assembling the slave preforms as previously described, forging and quenching the assembled preforms as previously described, would result in a primary member having a uniform through hardened structure. | A novel and improved method of forging preselected recessed surfaces in a member is disclosed which comprises the steps of adding a suitable lubricant material to at least a slave or primary preform member wherein the lubricant material is sufficient to prevent welding between the noted preforms during the forging operation. Moreover, the method envisions the step of joining the slave preform to the primary body preform member, followed by forging the joined together preforms such that the primary preform member is deformed to an extent generally complementary to a portion of the configuration of the slave preform, such that the forged primary preform has formed therein a shaped recess generally complementary to at least a portion of the configuration of the slave preform. It is contemplated that the forged slave and primary preforms are quenched subsequent to forging. Thereafter, the method contemplates removing the quenched slave preform from the primary preform. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved socket assembly for use with an integrated circuit device or package (IC), having a socket which opens with force applied on the top edges of the socket to allow insertion or removal of the IC, and in one aspect to an improved socket in that means are provided to indicate an opening of the contacts to allow insertion and/or removal of the IC.
2. Description of the Prior Art
Top loading sockets for integrated circuit devices or packages (IC's) are known and are used to connect IC's to printed circuit boards for test or burn-in by automated operations, or for the functional application affording the replacement of the IC without subjecting other components on a printed circuit board or the like to heat, to afford the removal or replacement of the IC. The sockets are designed to load and unload the IC from the top of the socket. This is done manually or by automatic machines, but in any event, the cover on the socket is forced toward the socket body and a plurality of contacts are moved against their biasing force to a retracted position allowing insertion or removal of the IC. It has become important when manual pressure is applied against the cover to know when the open position has been reached to limit the continual application of force to the cover.
Examples of the sockets or carriers of the prior art include applicant's own U.S. Pat. No. 4,993,955 disclosing a carrier for an IC device which has leads and which has a cam member inserted on the socket body to withdraw the contacts, against their inherent biasing force, from a contacting position to a retracted position upon the movement of the cover toward the socket body. There are other patents which show a top load socket having similar top load characteristics but these sockets have the cover engaging each of the plurality of contacts directly to retract the same. These patents include patents such as U.S. Pat. No. 5,076,798 which have a socket body forming a support housing, a plurality of contacts and a contact shutter member comprising a pair of push-down operation portions disposed at both outer sides of the IC receiving window or opening. Guide members are used to maintain the movement of the shutter portions in the vertical direction. This patent also illustrates the use of a pushing portion 21 on the push-down operation portions 18, which has an initial gently inclined surface 21a at a front stage pushing portion and with a steeply inclined surface 21b at a rear stage pushing portion 21b. These portions are formed as linear surfaces and engage the pressure receiving portions 11 of each of the contacts 4. This patent, however, is not considered to provide a teaching of the present invention since the teaching of this patent is to use a gently inclined surface against the contact during the initial retracting stage when the resilient displacement can be obtained by a comparatively small displacement force, and the push-down force is abruptly reduced by using the rear stage steeply inclined surface 21b on the contact 4 to perform the remaining displacement at the latter half stage where the resilient force is increased, thereby achieving a targeted displacement amount and a targeted generally uniform push-down force since the push-down force can be reduced as a whole and a required amount of backward displacement can be obtained with a limited push-down stroke.
The present invention has as its purpose the creation of a change (or step) in the retracting movement of the cover to create an audible sound and/or a sharp change in the force needed to depress the cover and to provide a sensory indication to the operator that, and when, the contacts have reached a retracted open position for reception or removal of the IC.
In the socket of the present invention, the retraction device to retract the contacting portion of the contacts restricts displacement of the contacting portion and assures positive movement of the contacting portion. Further, there is a noted change in the retraction force during the lineal movement of the cover to clearly indicate that the socket is in the open position with the contacting portions of the contacts retracted.
SUMMARY OF THE INVENTION
The socket assembly of the present invention is adapted for use with an integrated circuit device having a plurality of leads arranged along at least one side of the device, and generally four sides. The assembly comprises a socket body having a generally rectangular configuration. The socket body is provided with spacers along at least one side for receiving a plurality of contact elements which are generally planar and are disposed in spaced parallel aligned arrays along the side or sides of the socket body. Each contact element comprises a terminal for connecting the contact element with an external electronic member, an anchor for anchoring the contact element to the socket body, a contacting portion for making resilient pressure contact with a lead or the contact point of an IC (integrated circuit device), and a resilient portion affording the movement of said contacting means from a first normal unflexed position to an open position for receiving an IC and to an operative position in pressure electrical contact with a lead on the IC. A cam member is positioned along the side of said socket body, or along two sides or along each side, and is supported by the socket body for engaging said contact elements to urge the contacting portion thereof from said normal position to the open position. The cam member is operative upon movement of a cover or a top plate supported above the socket body, which cover is mounted for sliding movement in relationship to said socket body from a first position to a second position, affording movement of the cam surface of said cam member for moving the contact elements to an open position upon movement of the cover toward the socket body and to release the contact elements upon movement thereof in a direction away from the socket body. The present invention affords to an operator an indication of when the contacts have been moved to the open position and this is accomplished by the cam follower engaging a cam surface formed with an irregularity in the surface to provide a sensory indication of the position of the cover in relationship to the socket body. The irregularity is a ridge or rib extending transverse to the cam surface at the point where the cam surface makes an abrupt change in contour from a constant initial planar surface at an angle of 50° to the surface of the cover to an abrupt steeper planar surface, the slope of which is at an angle of 85°, to substantially reduce the force required for the continued movement of the cover toward the socket body. A ridge or rib is thus formed at the transition line between the surfaces. A sound may be generated by the cam follower passing over the rib and the force required to continue the movement of the cover is significantly changed so the feel of the cover changes providing an indication to the operator that the contacts are moved to the open position.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in detail with reference to the accompanying drawing wherein:
FIG. 1 is a top plan view of the top load socket assembly of the present invention,
FIG. 2 is a side view, partially broken away for purposes of illustration, of the socket assembly of FIG. 1;
FIG. 3 is a perspective-exploded view of the socket assembly, with the cover partially broken away, only one of four cam members illustrated and only two of the contact elements;
FIG. 4 is an enlarged detail perspective sectional view of the area shown in the circle of FIG. 3;
FIG. 5 is a transverse sectional view of the socket assembly of the present invention taken along an irregular section line to show on the left side the position of the contact in the contacting position with the lead of an IC and showing on the right side of the view the position of the cam in relationship to the cover in this same position;
FIG. 6 is a transverse sectional view of the socket assembly of the present invention taken along an irregular section line similar to FIG. 7 to show on the left side the position of the contact in substantially the open position away from the lead of an IC and showing on the right side the position of the cam in the same position;
FIG. 7 is a transverse sectional view of the socket assembly of the present invention taken along an irregular section line as in FIGS. 7 and 8 to show on the left side the relationship of the parts with the contact in the retracted position and showing on the right side the position of the cam with the opening force substantially removed; and
FIG. 8 is a graph illustrating the force curve defined to open the socket assembly of the present invention and to compare this force curve with that of other existing products.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The socket assembly of the present invention provides a positive acting cam for moving the contacting portions of the many contacts from a first rest position, to an open IC receiving position, and then to pressure contacting electrical connection with the leads or contact points of an IC placed in the socket assembly. The cam member affords positive engagement with the contacts and restricts displacement of the contacting portions thereof and allows free movement thereof into the contacting position.
Referring now to FIGS. 1 through 4, there is illustrated a socket assembly 10 for use with an IC 11, which assembly is top loading to facilitate automated or manual loading and unloading of the socket to test and burn-in Ics rapidly. The socket assembly 10, illustrated in exploded view in FIGS. 3 comprises a top plate or cover 12 of generally rectangular shape, in this embodiment square, to receive a plastic leaded chip carrier IC package having leads 13 along all four sides in close spaced relationship. The cover has a depending leg 14 at each corner formed with a lower hook member to hold the cover in a predetermined spaced position from a socket body 15. The cover is formed with a central opening or window 16 to receive the IC device. The socket cover 12 is also formed with cam surfaces 17 adjacent each side of the corners and a plurality of closely spaced recesses 18 along each side for receiving the upper free contacting ends of a plurality of contacts 25.
A socket body 15, shown most clearly in FIG. 3, is also generally square in plan view with corners similar to that of the cover 12, except the corners are formed with recesses to receive the legs 14 of the cover 12 which legs 14 latch below the recesses in the corners of the body 15. Along the sides of the socket body 15 are recesses 21 to receive the plurality of contacts 25 and anchor the contacts thereto. The socket body 15 is provided with a central area defining a support for the IC 11, which support is defined by four support posts 24 symmetrically arranged within the center of the socket body and upon which the bottom of the IC will rest as illustrated in FIGS. 2, 5, 6 and 7. The socket body 15 is symmetrical and has four sides. Each side has a recess 28 at the ends adjacent to the corner. These recesses 28 receive and journal or cradle one end of a cam member 30. The recesses 21 space and support the contacts 25, with the anchoring portion 35 positioned in the recess and the pin type lead 36 thereof extending to a position below the socket body for engagement with an opening is a printed circuit board. The contacts 25 have an arcuate resilient portion 37 which is adapted to surround the cam member 30, and the arcuate portion terminates in a contacting portion 38 on the free end for making electrical contact with the lead or post on the IC device to make an electrical connection thereto.
The cam 30, as best illustrated in FIGS. 2 and 3, comprises a bar having opposite ends with a cam follower 31 and a rocker 32 formed at each end. The rocker supports the cam on the socket body 15 in the recesses 28 and the cam followers 31 are positioned to engage the cam surfaces 17 of the cover. Between the ends of the cam 30 and aligned with the recesses 21 and the recesses 28 are slots 34 formed in the outside walls of the cam 30 to receive the arcuate resilient portions 37 of the contacts 37 to maintain the same in spaced positions as the cam forces the contacts from the contact position to an open position which is a position during which stress is placed on the arcuate resilient portions 37 which may cause them to flex. The bar is formed with cam lobes extending radially from the axis of the bar along the upper face at the ends of slots 34, for engaging the contacts 37 adjacent the contacting portion 38. The cam followers 31 at each end of the bar comprise arm means extending radially from the bar to engage the cam surfaces 17 on the cover 12, causing the bar to oscillate to urge the cam lobes against the contacts to force the contacting portions 38 of the contacts 25 from a normally closed position to an open position.
During assembly of the socket, the contacts are stitched along each side of the socket body 15 into the recesses 21. The cam members 30 are placed along each side of the socket body 15 with the rockers 32 in the recesses 28. The cover 12 is then placed onto the socket body 15 and the legs 14 lock the cover thereon. The vertical movement of the cover 12 toward and away from the socket body 15 causes the cams 30 to rock under the force of the cam followers following a first face 17a of the cam surfaces 17 on the cover 12. As shown in FIG. 5, the contacting portions 38 of the contacts are in forcible electrical contact with the lead of the IC 11. The cam follower of the cam 30 is positioned against the surface 17a. As the cover is moved toward the socket body 15, the cam follower 32 rides along the surface 17a, rotating the cam and causing the upper face to engage the contacts adjacent the contacting portions 38 to drive the same away from the contacting position as shown in FIG. 6. Upon the cam follower 31 reaching a discontinuity or irregularity in the surface 17a of the cam surface as at 17b, the cover moves with substantially less force toward the socket body 15, and the operator, during manual opening of the socket, can feel the change in opening force required and is aware that the contacts have been moved to the open position. This is illustrated in FIG. 7 wherein the cam follower 31 has moved to a position to follow the surface position 17c, until the cover reaches a stop position. The stop position is reached when the upper surfaces of the members 29 at the corners of the socket body 15 engage the lower surfaces of the cover at the corners. Further movement of the cover is restricted.
The contacts 25 are preferably formed from flat conductive sheet stock and typically there are contact elements along each side spaced a distance of 0.5 mm to 0.65 mm. The contact elements 25 are designed to have a contact force against the leads of the IC device of approximately 50 to 70 grams. In a socket with 52 total contacts, positioned 13 to a side of the socket body, the total force needed to retract the contacts approaches 1.85 kilograms. The cam serves to provide considerable mechanical advantage to the force needed to have each contact disengage the IC leads. As the 35 contacting portions 38 of the contacts 25 are retracted, with the cam follower moving along cam surface 17a the force required to move the cover is approximately 1.85 kilograms and as the cam follower passes the rib 17b the force then drops to 1.65 kg during the continued movement. The cam surface 17c is not at 90 degrees to the face of the cover but only sufficiently inclined to allow the force of the contacts to assist in retracting the cover from the position adjacent to the socket body to the initial closed position.
The graph shown in FIG. 8 illustrates a profile of the force F needed to open the socket assembly of the present invention, see solid line 40, plotted against the displacement D of the contacting portion of the contact elements. FIG. 8 also makes a comparison of the forces needed to open the socket assembly of the present invention against the 52 lead PLCC socket of Enplas of Dai-ichi Seiko Co. Ltd of Japan or Enplas-Dai-ichi Seiko of Kawaguchi City of Japan, see the dashed line 41 and legend on the drawing, against the 52 lead PLCC socket of 3M, the assignee of the present application, see the line broken and filled with a dash 42, a 52 lead PLCC socket of Wells Electronics, Inc. of South Bend, Ind. indicated by the broken line 43, and a 52 lead PLCC socket of Texas Instruments Inc. of Dallas, Tex., indicated by the dotted line 44. The graph was generated using a series 1X, Model 1122 Instron Test Instrument. The graph illustrates the opening forces and the closing force against the resistance of the instrument such that for each curve there is an initial positive line and a return line. The graph shows the socket of the present invention has a constant opening force to retract the contacts by 142 mm at which time the cam follower 30 reaches the detent defined by the surface 17b and then the force drops off during the remaining travel of the cam follower and the final opening of the contacts to 188 mm. The Texas Instruments socket requires less opening force and greater displacement of the contact.
Having thus described the present invention, it will be appreciated that changes or modifications can be made in the disclosed and described embodiments without departing from the invention as recited in the appended claims. | A socket assembly for top-loading IC devices having a cam member, actuated by a vertically moving cover, and having means on the camming surface to produce a sensory act to provide an indication to the operator that the socket contact elements have been moved to an open position as the cover is moved toward the socket body. The sensory act can be audible or feel. | 7 |
FIELD OF THE INVENTION
The present invention relates to a device for collecting a sample of exfoliated cells from a colorectal mucosal surface of a human subject, to a kit comprising said device and to methods of colorectal cell sampling using said device.
BACKGROUND OF THE INVENTION
Sporadic colorectal cancer (CRC) is one of the most frequently occurring and deadly of the oncological diseases affecting people in developed Western countries. It predominantly affects people over the age of 50.
A serious obstacle to early diagnosis of CRC is the absence of early, readily identifiable clinical manifestations in the majority of cases. It is only in the advanced stages of the disease, when larger tumours have formed, resulting in pain, bleeding and symptoms of obstruction, that the disease is readily diagnosed. However, the late stages of the disease are also associated with invasive or metastatic tumours. Thus, detection of colorectal tumours prior to the advanced stages of the disease would greatly increase the chances of successful surgical intervention and overall survival rates.
In the absence of early, readily identifiable clinical indications, the search for suitable CRC screening methods has continued for decades. Unfortunately, there is presently no CRC screening technique that combines low invasiveness, simplicity and low cost with high sensitivity and specificity. Two methods of screening for CRC are flexible colonoscopy/sigmoidoscopy and faecal occult blood testing (FOBT) [Rennert, G. Recent Results Cancer Res. 2003; 163: 248-253, Atkin, W. Scand. J. Gastroenterol. (Suppl.) 2003; 237: 13-16, Walsh, J. M. and Terdiman, J. P. JAMA 2003; 289: 1288-1296]. However, both of these methods have significant drawbacks.
Flexible colonoscopy/sigmoidoscopy is regarded as a precise and reliable diagnostic procedure, however, its invasiveness, cost and requirement for skilled and experienced specialists to carry out the procedure make its use in routine screening impractical. The same is true for recently introduced computed tomographic colonography (virtual colonoscopy).
FOBT is cheap and simple, however, it produces unacceptably high rates of both false negative and false positive results. Despite these limitations, FOBT is presently the screening method of choice.
Alternative methods of diagnosing CRC based upon a direct indicator of tumour presence have been investigated. One indicator that has been identified is analysis of exfoliated colonocytes. Exfoliation of colonocytes (i.e. spontaneous detachment of cells from orderly organized epithelial layer of colonic mucosa) is an important cell renewal mechanism in the human gut [Eastwood, G. L. Gastroenterology 1977; 41: 122-125]. Cytological analysis of colonocytes obtained from colonic or rectal washings (i.e. by irrigation of the colorectal mucosa) was carried out approximately 50 years ago [Bader, G. M. and Papanicolau, G. N. Cancer 1952; 5: 307-14]. This work showed that morphologically distinct exfoliated neoplastic cells could be detected in CRC patients. However, the method of obtaining these samples (an invasive colonic lavage procedure) suffered from the same disadvantages as sigmoidoscopy/colonoscopy, and required detailed cytological analysis of the sample once obtained.
The prevailing approach to obtaining samples of exfoliated epithelial cells has been to isolate them from human faeces. Human faeces were identified as a source of such cells, as the exfoliated cells of the colonic epithelium can be excreted in conjunction with other faecal matter.
The first attempts to use colonocytes isolated from human faeces for diagnostic and research purposes were started about 15 years ago by P. P. Nair and his colleagues. They claimed to be able to recover thousands of “viable” exfoliated cells from a few grams of dispersed faecal material using an isolation procedure based on density gradient centrifugation [Iyengar, V. et al., FASEB J 1991; 5: 2856-2859, Albaugh, G. P. et al., Int. J. Cancer 1992; 52: 347-350]. However, these ambitious claims have generated substantial doubts due to the low likelihood of the presence of well-preserved colonocytes in an aggressive anaerobic environment such as that found in the faeces. Furthermore, morphological evidence presented in their 1991 reference was unconvincing. P. P. Nair and members of his group maintain the validity of their approach [Nair, P. et al., J. Clin. Gastroenterol. 2003; 36(5 Suppl.) S84-S93], but have not produced any practical advances based on the outcomes of their studies.
However, despite the lack of practical advances by P.P. Nair and his colleagues, the use of human stool for diagnostic and research purposes remains an active research area as it is not associated with any invasive intervention. A number of groups have undertaken attempts to isolate colonocyte-derived genetic material (DNA) from human stool samples in order to develop diagnostic procedures employing molecular biomarkers of malignancy. Whilst DNA directly isolated from homogenized faeces can be amplified and analysed for the presence of cancer-associated genetic alterations, the absence of a highly reliable single molecular biomarker for cancer resulted in the use of multiple molecular markers reflecting a number of genetic alterations known to be present in malignant cells at relatively high frequencies. Several approaches proposing simultaneous detection of multiple mutations in the APC, K-ras and p53 genes combined with microsatellite marker analysis have been described [Ahlquist, D. A. et al., Gastroenterology 2000; 119: 1219-1227, Dong, S. M. et al., J. Natl. Cancer Inst. 2001; 93: 858-865, Rengucci, C. et al., Clin. Cancer Res. 2001; 93: 858-865, Traverso, G. et al., N. Engl. J. Med. 2002; 346: 311-320]. Methylation changes in faecal DNA have also been considered as a potential diagnostic marker [Muller, H. M. et al., Lancet 2004; 363: 1283-1285]. Although detection of colorectal tumours by multi-target molecular assays appears to be feasible, the validity of these methods for screening purposes remains questionable due to the high cost and relative complexity of laboratory procedures involved.
The search for CRC molecular markers in DNA extracted from homogenized stool samples has overshadowed the importance of the initial collection/isolation of exfoliated colonocytes. It is, however, apparent that homogenized stool is a difficult material for human DNA extraction. In particular, the abundance of bacteria in faeces can interfere with colonocyte DNA recovery procedures, and rapid mammalian DNA damage and degradation occur in the presence of anaerobic bacterial flora of the human colon.
The development of approaches based upon exfoliated colonocyte isolation has been slow partially due to a surprising lack of knowledge on cell exfoliation in the gut both in normal physiological conditions and in disease. The current views on colonocyte exfoliation are still affected by an old and unproven hypothesis implying “obligatory” exfoliation of nearly all differentiated colonocytes upon their migration to the luminal epithelium from the colonic crypts (i.e. it is presumed that there should be millions of colonocytes present in faecal matter because the cell proliferation rate of colonic epithelium is high and all cells are eventually exfoliated). It is, however, becoming clear that programmed cell death or apoptosis in situ is at least as important as exfoliation [Hall, P. A. et al., J. Cell Sci. 1994; 107: 3569-3577, Barkla, D. H. and Gibson, P. R. Pathology 1999; 31: 230-238, Ahlquist, D. A. et al., Hum. Pathol. 2000; 31: 51-57]. The relationship between these two major mechanisms of cell removal from colonic mucosa may undergo significant changes in colorectal neoplasia [Ahlquist, D. A. et al. (supra)]. Indeed, it is now proven that normal regulatory pathways leading cells to apoptosis are severely deregulated in malignant tumours [Bedi, A. et al., Cancer Res. 1995; 55: 1811-1816, LaCasse, E. C. et al., Oncogene 1998; 17: 3247-3259, Jass, J. R. Gastroenterology 2002; 123: 862-876, Oren, M. Cell Death Differ. 2003; 10: 431-442, Boedefeld, W. M. 2nd et al., Ann. Surg. Oncol. 2003; 10: 839-851] resulting in a greatly reduced apoptotic potential of cancer cells. At the same time, tumour cell adhesion is known to diminish dramatically as cancer progresses [Yamamoto, H. et al., Cancer Res. 1996; 56: 3605-3609, Haier, J. and Nicolson, G. L. Dis. Colon Rectum 2001; 44: 876-884, Leeman, M. F. et al., J. Pathol. 2003; 201: 528-534]. The latter phenomenon is important for metastatic spread, however in colorectal neoplasia, combined suppression of apoptosis and decrease in intercellular adhesion/communication greatly increases the chances of malignant cell shedding from the surface of growing tumours. If this is the case, exfoliated tumour cells, some of which can probably retain proliferative potential, should differ from their normal (non-tumour) exfoliated counterparts in: i) being more abundant due to facilitated exfoliation from the tumour surface; and ii) having much greater “survival” capacity, in particular due to higher resistance to the lack of oxygen [Graeber, T. G. et al., Nature 1996; 379: 88-91]. Upon exfoliation, these cells enter a relatively well oxygenated “mucocellular layer” that separates the colonic mucosa from the faecal contents of the gut and permanently moves distally with the flow of faeces [Ahlquist, D. A. et al. (supra)].
The importance of the mucocellular layer providing an interface between colorectal mucosa and faecal contents of the gut has not been understood until recently. Experimental studies indicated that good quality DNA could be easily obtained from the surface of rat faeces and used for further amplification and gene mutation analysis [Loktionov, A. and O'Neill, I. K. Int. J. Oncol. 1995; 6: 437-445]. These early experiments suggested that DNA extracted from colonocytes isolated from human stool surface (stool surface can be regarded as a fraction of mucocellular layer excreted with faeces) could be used for molecular analysis. A method of exfoliated cell isolation from human whole stool samples by washing cells off the surface of cooled faeces and collecting them by immunomagnetic separation procedure has been developed [Loktionov, A. et al., Clin. Cancer Res. 1998; 4: 337-342]. Although work in this direction was initially planned in terms of developing a molecular diagnostic assay for CRC, it emerged that a simple quantitative analysis of colonocyte-derived DNA from human stool surface could be used for CRC diagnosis and screening since the relative DNA amount in CRC patients was much higher compared to healthy individuals. Other authors have also reported higher amounts of either exfoliated cells [Dutta, S. K. et al., Gastroenterology 1995; 108 (Suppl.): A463] or DNA [Villa, E. et al., Gastroenterology 1996; 110: 1346-1353] in dispersed or homogenized stool samples obtained from CRC patients, however the differences between healthy people and cancer patients observed in those studies were not large enough to be considered diagnostically valid. By contrast, Loktionov et al (supra) were able to show the existence of a striking difference between CRC patients and healthy individuals employing a calculated index relating to the amount of DNA extracted from cells isolated from the stool surface to stool weight (stool DNA index or SDNAI).
The SDNAI-based diagnostic method is described in U.S. Pat. No. 6,187,546. Although the technique and results of its initial trials apparently highlighted a very efficient, simple and inexpensive approach to CRC screening, it had a number of substantial faults (apparent difficulties of whole stool handling and especially impossibility of the procedure standardization) preventing its commercialization and serious introduction into clinical practice. It has also become clear that relatively small numbers of well-preserved cells can be obtained from human stool surface using this technique [Bandaletova, et al., APMIS 2002; 110: 239-246]. These problems, difficulty of standardization being the crucial one, cause serious doubts with regard to using exfoliated colonocytes isolated from stool samples for wide scale CRC screening.
There is a good body of evidence indicating that the mucocellular layer covering human rectal mucosa is particularly rich in well-preserved exfoliated colonocytes. In addition, the cellular content of this layer in CRC patients appears to be much higher than in healthy individuals primarily due to greatly increased presence of highly resistant malignant colonocytes. Therefore CRC patients' tumour cells, which are much better adapted to autonomous existence, should quantitatively dominate the rectal exfoliated cell pool. Several recent reports describing distal (e.g. anal) implantation of persisting exfoliated cells from removed colorectal tumours [Jenner, D. C. et al., Dis. Colon Rectum 1998; 41: 1432-1434, Wind, P. et al., Dis. Colon Rectum 1998; 41: 1432-1434, Isbister, W. H. Dig. Surg. 2000 ; 17 : 81 - 83 , Hyman, N. and Kida, M. Dis. Colon Rectum 2003; 46: 835-836, Abbasakoor, F. et al., Ann. R. Coll. Surg. Engl. 2004; 86: 38-39] strongly corroborate this hypothesis.
Direct access to the rectal mucosa is possible by routine digital rectal examination with an examiner's gloved finger. However, although one can achieve a contact with the rectal mucocellular layer by employing this simple manipulation, significant losses of material and simultaneous contamination with irrelevant squamous epithelium of the anal canal are inevitable during the removal of the finger from the rectum. Smears prepared from gloves used for rectal examination have shown well-preserved colonocytes, combined with a high level of contamination by cells of the squamous epithelium.
There is thus a great need for direct collection of exfoliated epithelial cells from the surface of rectal mucosa without the problems of material loss and serious contamination with other tissue elements at the stage of removal of the cell-collecting surface from the rectum. Such cells could be used not only for quantitative cell and DNA analysis, but also investigated for the presence of additional cancer biomarkers (e.g. proteins) and finally assessed immunohistochemically and cytologically.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, there is provided a colorectal cell sampling device comprising:
a colorectal insertion member having a distal, insertion end, a proximal end and a closable interior cavity; a flexible membrane having an outer, cell sampling surface and an inner surface, wherein said membrane is sealingly attached to the distal, insertion end of said insertion member and held within the interior cavity; such that, in use, pressurisation of the interior cavity to at least a first elevated pressure causes the membrane to emit from the distal end of said insertion member to make contact with the colorectal mucosal surface and pressurisation of the interior cavity to a second reduced pressure causes the membrane to invert and return to the interior cavity of said insertion member.
The device overcomes the difficulties with digital sampling by holding the flexible membrane within the insertion member both on insertion and withdrawal so that there is no material loss and the sample is not contaminated by cells from other surfaces (e.g. the squamous epithelium).
By sampling the mucosal surface directly, the device overcomes the difficulties associated with whole stool sampling including, the unpleasant nature of the work, the low concentration of cells obtainable, the high levels of contamination with faecal matter (especially bacteria), and especially method standardization difficulties related to such problems, for example, great variability of stool size and consistency.
Although the device is invasive, it is far less invasive than the devices currently used for colonoscopy/sigmoidoscopy, and does not require operation by a skilled and highly trained operator. The device may even be self-administered. The reduced level of invasiveness and the absence of complication risk are likely to lead to greater patient acceptance. These advantages should in turn allow for more sampling to be carried out, and at a lower cost.
In a preferred embodiment of the invention, the flexible membrane is expandable and is constructed from an elastic material. More preferably, the flexible membrane is constructed from a nitrile, latex or rubber based substance.
In a preferred embodiment of the invention, the closable interior cavity of the insertion member is closed.
In a preferred embodiment of the invention, the cell sampling device further comprises means for pressurisation of the interior cavity, wherein said means are attached to the proximal end of the insertion member.
Preferably, said means for pressurisation of the interior cavity are attached to the cell sampling device via a valve (e.g. a self-sealing valve) present at the proximal end of the insertion member.
It will be appreciated that the means for pressurisation of the interior cavity may comprise any means suitable for applying a fluid (e.g. liquid or gas) to the flexible membrane. Preferably, the means for pressurisation of the interior cavity comprise a source of compressed air, a syringe or a pump (e.g. bulb).
Preferably, the means for pressurisation of the interior cavity comprise a source of compressed air which comprises a mechanical device capable of delivering a pre-defined quantity of a first elevated pressure and a second reduced pressure to the cell sampling device. This embodiment has the advantage of accurately regulating the pressure inside the insertion member and the mechanical device has the advantage of being re-used with an indefinite number of disposable colorectal cell sampling devices.
More preferably, the means for pressurisation of the interior cavity comprise a syringe. The use of a syringe, allows for both simple operation, and for a fixed volume of air to be pumped into the flexible membrane (preferably at least a ten fold increase in the volume of air present in the flexible membrane). For example, in an embodiment of the invention where a 100 ml syringe is attached at the proximal end of the insertion member, the plunger of said syringe could initially be set at the 70-90 ml mark. A pre-defined quantity of a first elevated pressure could therefore be applied by pushing the plunger to its maximum extent (e.g. to the 0 ml mark) which would fill the flexible membrane with an air volume of 70-90 ml. A pre-defined quantity of a second reduced pressure could then subsequently be applied by pulling the plunger of the syringe back to its maximum extent (e.g. to the 100 ml mark) which would draw the membrane into the interior cavity of the insertion member. In a preferred embodiment of the invention, the syringe would be supplied with one or more retention features (e.g. snap locations) to mark the plunger positions of the syringe at each stage during use (e.g. one position prior to insertion, one during insertion and one after withdrawal). The advantage of the means for pressurisation of the interior cavity being a syringe is that the colorectal cell sampling device may be adapted to fit onto commonly available and disposable laboratory and hospital equipment.
In a preferred embodiment of the invention, the surface area of the outer, cell sampling surface of said flexible membrane is reproducibly controllable. This allows for a fixed surface area to be brought into contact with the colorectal mucosal surface being sampled, thereby providing a quantifiable collection of exfoliated cells which is correlated with the amount present on the surface of the colorectal mucosa. Preferably, the surface area is controlled by the means for pressurisation of the interior cavity. This allows for a fixed surface area to be brought into contact with the mucosal surface being sampled.
In a preferred embodiment of the invention, the insertion member is adapted to engage with a rectal access tube. This embodiment has the advantage of allowing a rectal access tube and an obturator, such as an olive shaped obturator (a conjoined rectal access tube and obturator is commonly known as a proctoscope) to be inserted first to open the rectal cavity followed by withdrawal of the obturator prior to insertion of the sampling device of the invention. The sampling device could then remain held in position with the rectal access tube for whatever period of time was required to obtain a sample. The obturator would then be replaced once the sampling device is removed and the obturator and rectal access tube would be withdrawn together.
In a preferred embodiment of the invention, the insertion member is configured to allow self-insertion. In such an embodiment, the insertion member is inserted together with a rectal access tube and therefore eliminates the need for an obturator (e.g. the insertion member has a rounded distal, insertion end). This embodiment provides the advantage that the sampling device of the invention may be self-administered, for example, patients will be easily able to sample exfoliated cells from their rectal mucosa. In this embodiment, it is envisaged that the insertion member and rectal access tube are inserted and removed together and only separated upon removal.
In a preferred embodiment of the invention, the flexible membrane forms a receptacle when held within the interior cavity of said insertion member, such that fluid may be added. This embodiment of the invention would allow for reagents to be added to the sampling device after a sample has been obtained without the need to transfer the sample to a separate receptacle, thereby losing some of the material from the sample.
In a preferred embodiment of the invention, the interior cavity of the insertion member is provided with adhesion means. This embodiment of the invention has the effect of drawing the flexible membrane towards the walls of the interior cavity of the insertion member once a sample has been obtained and application of the second reduced pressure has drawn the flexible membrane into the interior cavity of the insertion member. This feature has the advantage of providing a stable receptacle when filled with liquid.
In a preferred embodiment of the invention, the insertion member is adapted to engage with a sealing means to seal said receptacle. This would allow the sampling device, containing the sample, to be stored and transported prior to further analyses being carried out on the sample.
Preferably, the sealing means is a threaded cap. A threaded cap has the advantage of sealing the receptacle to prevent loss of sample and also allows removal for further analysis.
In the embodiment wherein the cell sampling device comprises means for pressurisation of the interior cavity, said means are preferably detachable from the insertion member. This has the advantage of converting the sampling device into a compact assay vial which may be conveniently transported and stored with many other compact assay vials for subsequent screening reactions.
In a second aspect of the invention, there is provided a kit for collecting a sample from a colorectal mucosal surface of a human subject, which comprises a colorectal cell sampling device as defined herein and a rectal access tube and optionally an obturator.
The use of a rectal access tube provides both for more comfortable insertion of the sampling device, and prevents contact between the sampling device and any surface other than the mucosal surface to be sampled. The use of an obturator in addition to the rectal access tube, may ease the discomfort of inserting the rectal access tube.
In a preferred embodiment of the invention, the kit may additionally comprise a lubricant, such as a lubricating jelly (e.g. K-Y jelly). This has the advantage of providing greater comfort during insertion of the obturator or cell sampling device of the invention.
In a preferred embodiment of the invention, the obturator is disengaged from the rectal access tube after insertion of the conjoined obturator and rectal access tube into the rectal cavity.
In a preferred embodiment of the invention, the kit further comprises sealing means, such as a threaded cap, to engage with the insertion member.
In a preferred embodiment of the invention, the kit further comprises one or more reagents, such as a buffer. The use of a buffer allows for the preparation of the sample prior to further analysis.
In a preferred embodiment of the invention, the buffer may be present in the threaded cap (e.g. as a blister packet), such that securing the cap to the insertion member releases the buffer into the receptacle (e.g. by piercing the blister packet) to suspend the cells present on the sampling surface of the flexible membrane prior to further analysis.
In a preferred embodiment of the invention, the buffer is a cell-lysis buffer which has the advantage of providing a key step prior to DNA extraction. In an alternatively preferred embodiment of the invention, the buffer is a cell-preserving medium which has the advantage of allowing enhanced cytological, biochemical and immunohistochemical analyses on the resultant cell sample. Preferably, the cell-preserving medium is supplemented with one or more cell culture components (e.g. nutrients and antibiotics).
It will be further appreciated by the person skilled in the art that any of the devices or kits previously described are suitable for sampling exfoliated epithelial tissue (e.g. colonocytes) from the surface of human colorectal mucosa.
In a third aspect of the invention there is provided a method of quantitative sampling of exfoliated cells from a colorectal mucosal surface of a human subject without contaminating the sample by contacting other body surfaces comprising the steps of:
bringing a sampling device comprising a sequestered cell sampling surface into proximity with the colorectal mucosal surface to be sampled, without making prior contact with any other body surface; contacting the cell sampling surface with the colorectal mucosal surface such that a sample is obtained from the mucosal surface; and removing the sampling device and sample from proximity with the mucosal surface without the sequestered cell sampling surface or sample making contact with any other body surface.
This method encompasses the key steps of directly sampling exfoliated cells from a mucosal surface, and ensures that the sample is not contaminated by the cell sampling membrane making contact with other body surfaces. Contamination is avoided by sequestering the sampling surface, wherein sequestering may be defined as isolating or setting apart the sampling surface prior to bringing it into contact with the colorectal mucosal surface or after collecting cells from the colorectal mucosal surface.
In a fourth aspect of the invention there is provided a method of sampling exfoliated cells from a colorectal mucosal surface of a human subject, comprising the steps of:
inserting a colorectal cell sampling device according to the invention into the rectal cavity and bringing said device into proximity with a colorectal mucosal surface without the outer, cell sampling surface of the flexible membrane making prior contact with any other body surface; pressurising the interior cavity to at least a first elevated pressure so that the flexible membrane emits from the distal end of the sampling device; contacting the colorectal mucosal surface with the outer, cell sampling surface of said membrane such that a sample of exfoliated cells is obtained from the colorectal mucosal surface; applying a second reduced pressure to the interior cavity so that the flexible membrane inverts and the sample present on the cell sampling surface of said membrane returns to the interior cavity of the cell sampling device; and removing the cell sampling device from proximity with the colorectal mucosal surface and withdrawing said device from the rectal cavity without the membrane or sample making contact with any other body surface.
It will be appreciated that the cell sampling device may additionally require a rectal access tube either alone or together with an obturator.
Thus, in a preferred embodiment of the invention, the method additionally comprises the steps of:
inserting a conjoined colorectal cell sampling device according to the invention and a rectal access tube into the rectal cavity; and removing said sampling device and sample from the rectal access tube.
In a preferred embodiment of the invention, the method additionally comprises the steps of:
inserting a conjoined rectal access tube and an obturator into the rectal cavity; withdrawing the obturator from the rectal access tube prior to inserting a sampling device; removing the sampling device and sample; replacing the obturator via the rectal access tube; and withdrawing the conjoined rectal access tube and obturator from the rectal cavity.
In a fifth aspect of the invention there is provided a method of sampling exfoliated cells from a colorectal mucosal surface of a human subject, comprising the steps of:
inserting a rectal access tube and an obturator into the rectal cavity via the anal canal; withdrawing the obturator from the rectal access tube; inserting a colorectal cell sampling device according to the invention into the rectal cavity via the rectal access tube, without the flexible membrane of the sampling device making contact with any other body surface; pressurising the interior cavity to at least a first elevated pressure so that the flexible membrane emits from the distal end of the sampling device; contacting the colorectal mucosal surface with the outer, cell sampling surface of said membrane; obtaining a sample of exfoliated cells from the colorectal mucosal surface; applying a second reduced pressure to the interior cavity so that the flexible membrane inverts and the sample present on the cell sampling surface of said membrane returns to the interior cavity of the cell sampling device; withdrawing the cell sampling device from the rectal cavity via the rectal access tube, without the flexible membrane of the sampling device contacting any body surface; replacing the obturator via the rectal access tube; and withdrawing the rectal access tube and obturator from the rectum via the anal canal.
It will be appreciated that while the rectal access tube remains inserted in the rectal cavity, a further cell sampling device of the invention may be introduced into the rectal cavity. For example, the first cell sampling device may be introduced which comprises a cell-lysis buffer to allow DNA extraction and analysis (e.g. quantitation) of any sampled cells. Thereafter, a second cell sampling device may be introduced which comprises a cell-preservation medium to allow cytological, biochemical and immunohistochemical analysis of any sampled cells.
In an alternative aspect of the invention, there is provided a sampling device for collecting a sample from a mucosal surface located within a rectal cavity of a subject, comprising:
a substantially cylindrical body, which has an open cavity at the distal end and a closable cavity at the proximal end; a flexible membrane held within the substantially cylindrical body which forms a seal separating the open distal cavity from the closable proximal cavity; the two surfaces of the membrane being the proximal surface and the distal surface; and means for inflation and deflation, wherein the means for inflation can increase the internal fluid pressure of the closable proximal cavity when closed causing the membrane to evert from the distal end of the substantially cylindrical body until the distal surface of the membrane contacts the mucosal surface to be sampled; and the means for deflation can decrease the fluid pressure of the closed proximal cavity causing the membrane to invert so that the membrane is held within the substantially cylindrical body after the distal surface of the membrane has contacted the mucosal surface to be sampled.
In a preferred embodiment of the invention, the deflation means is the valve. This embodiment of the invention would be particularly suitable for use with an elastic membrane where the internal pressure in the closable proximal cavity is greater than that outside the cavity.
In a preferred embodiment of the invention, the deflation means comprises the syringe connected to the valve.
In a second alternative aspect of the invention, there is provided a method of sampling exfoliated cells from a mucosal surface located within the rectal cavity of a human subject, comprising the steps of:
bringing a sampling device according to the invention into proximity with a mucosal surface without the sampling membrane making prior contact with any other body surface; increasing the internal pressure of the closed proximal cavity so that the flexible membrane everts from the distal end of the sampling device; contacting the mucosal surface with the distal surface of the membrane such that a sample of exfoliated cells is obtained from the mucosal surface; decreasing the internal pressure of the closed proximal cavity so that the flexible membrane inverts, and it and the sample are held within the open distal cavity; and removing the device and sample from proximity with the mucosal surface without the membrane or sample making contact with any other body surface.
In a preferred embodiment of the invention, the method comprises the steps of:
attaching a source of compressed air to the valve, and increasing the internal pressure of the closed proximal cavity by opening the valve; or attaching a syringe to the valve and increasing the internal pressure of the closed proximal cavity by inserting the plunger.
In a preferred embodiment of the invention, the method comprises the steps of:
decreasing the internal pressure of the closed proximal cavity by opening the valve; or decreasing the internal pressure of the closed proximal cavity by withdrawing the plunger.
In a preferred embodiment of the invention, the method comprises the steps of:
adding a cell lysis buffer or cell preserving medium to the open distal cavity of the sampling device; and sealing the open distal cavity of the sampling device.
In a third alternative aspect of the invention, there is provided a method of sampling exfoliated cells from a mucosal surface located within the rectal cavity of a human subject, comprising the steps of:
inserting a rectal access tube and an obturator into the rectal cavity via the anal canal; withdrawing the obturator from the rectal access tube; inserting a sampling device according to the invention into the rectal cavity via the rectal access tube, without the flexible membrane of the sampling device making contact with any other body surface; connecting the sampling device to a means for inflation; increasing the internal pressure of the closed proximal cavity so that the flexible membrane everts from the distal end of the sampling device; contacting the rectal mucosa with a fixed surface area of the sampling surface; obtaining a sample of exfoliated cells from the surface of rectal mucosa; decreasing the internal pressure of the closed proximal cavity so that the flexible membrane inverts, and it and the sample are held within the open distal cavity; withdrawing the sampling device from the rectal cavity via the rectal access tube, without the flexible membrane of the sampling device contacting any body surface; replacing the obturator via the rectal access tube; withdrawing the rectal access tube and obturator from the rectal cavity via the anal canal; adding a cell lysis buffer or cell preserving medium to the open distal cavity; and sealing the open distal cavity of the sampling device.
In a fourth alternative aspect of the invention, there is provided a method of screening and diagnosis for colorectal cancer which comprises any of the methods set out above and further comprising recovering the collected sample from the sampling device and performing an analysis on the sample.
In a preferred embodiment of the invention, the analysis is selected from DNA quantitation, DNA extraction followed by its quantitation and optional molecular analysis, cytological/cytochemical investigation and biochemical tests. It is to be noted that the accuracy of screening by any of these methods will be improved by the provision of a sample with low levels of contaminants and a high concentration of cells taken from the colorectal mucosal surface being sampled.
BRIEF DESCRIPTION OF THE FIGURES
The invention will now be described, by way of example only, with reference to the accompanying drawings in which:
FIG. 1 shows a cross-sectional view of a cell sampling device of the invention.
FIG. 2 shows a schematic representation of a cell sampling device of the invention wherein the means for pressurisation comprise a syringe.
FIG. 3 shows a schematic representation of a cell sampling device of the invention wherein the means for pressurisation comprise a source of compressed air.
FIG. 4 shows the components required for sampling exfoliated cells from a colorectal mucosal surface of a human subject.
FIG. 5 shows an example of a method of sampling exfoliated cells from a colorectal mucosal surface of a human subject using any of the devices shown in FIGS. 1-4 .
FIG. 6 shows an example of the steps which may follow the method depicted in FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
Description of Cell Sampling Embodiments
The cell sampling device of FIG. 1 is designed for insertion into a rectal cavity. The device comprises a substantially cylindrical insertion member 1 with an interior cavity 3 , closed at the distal insertion end 2 by a flexible and resilient membrane 4 which is sealingly attached to the member 1 at the distal end 2 . In the position shown in FIG. 1 , the membrane 4 is held within the cavity 3 , and is adapted to emit from the cavity 3 when the cavity 3 is pressurised by means 7 (shown in more detail in FIG. 2 ). The membrane 4 has a cell sampling surface 5 which in the rest position shown in FIG. 1 is the inner surface, but when the membrane emits is the outer surface, and an opposing surface 6 which in the rest position is the outer surface, but which becomes the inner surface when the membrane emits. The membrane is made of nitrile, latex or a rubber based substance. At the proximal end 34 , the cavity 3 is closed by a self-sealing valve 18 , to which the pressurisation means 7 is adapted to be attached.
The embodiment of the invention wherein the means for pressurisation of the interior cavity 7 is an integrated syringe is shown in FIG. 2 which schematically also shows the steps necessary to sample exfoliated cells from a colorectal mucosal surface of a human subject ( FIGS. 2A-2D ).
FIG. 2A shows a representation of the cell sampling device prior to insertion into a rectal cavity. The syringe 7 is attached to an insertion member 1 substantially as described in FIG. 1 . The syringe has a plunger 23 which sealingly slides along a barrel 32 of the syringe 7 to alter the volume within an inner chamber 33 of the syringe 7 . The plunger 23 of the syringe 7 is set such that 70 ml of air is present within the chamber 33 of the syringe 7 .
FIG. 2B shows a representation of the cell sampling device once inserted into a rectal cavity. The plunger 23 of the syringe has been fully depressed which causes the flexible membrane 4 to inflate to a volume of 70 ml. The inflated flexible membrane 4 then makes contact with the colorectal mucosal surface of a human subject such that any exfoliated cells are transferred to the outer surface of the flexible membrane 4 .
FIG. 2C shows a representation of the cell sampling device once exfoliated cells have been sampled and prior to removal from a rectal cavity. The plunger 23 of the syringe 7 is retracted such that 80 ml of air is present within the chamber of the syringe 7 . This therefore creates a reduced pressure within the chamber which causes the flexible membrane 4 to be drawn back into the interior cavity of the insertion member 1 and adhere firmly to the side walls of the insertion member 1 . The amount of reduced pressure may be pre-quantified by the presence of two snap fit retention features 24 (only one of which is shown in FIG. 2C ). The snap fit features 24 are arms present on the plunger 23 of the syringe 7 which locate into holes on the barrel 32 of the syringe 7 . The purpose of the snap fit features 24 is to prevent withdrawal of the plunger 23 from the syringe 7 .
FIG. 2D shows a representation of the cell sampling device after removal from the rectal cavity and prior to cell analysis. The distal, insertion end of the insertion member 1 is provided with a thread which is adapted to receive a 20 mm diameter threaded screw cap 8 . The cap 8 may have a blister packet containing a buffer such that upon screwing the cap 8 to the insertion member 1 , the buffer is released into the receptacle formed by the deflated flexible membrane 4 . After the cap 8 has been screwed to the insertion member 1 , the syringe 7 may be detached from the insertion member 1 to allow the insertion member 1 to be converted to a compact assay vial which, along with a plurality of other vials, may be packaged and sent to a laboratory for cell analysis.
The embodiment of the invention wherein the means for pressurisation of the interior cavity 7 is a source of compressed air is shown in FIG. 3 . This figure schematically shows a mechanical device 9 which is a pump operated by an electrical motor (not shown) capable of delivering repeated doses of a first elevated pressure followed by a second reduced pressure upon activation of the trigger 14 . The mechanical device 9 is capable of attachment to an insertion member 1 substantially as described in FIGS. 1 and 2 by way of a click-fit locator 16 present on the mechanical device 9 which co-operates with a locating lug 17 on the insertion member 1 . A self-sealing valve 18 is present on the insertion member 1 to ensure pressure is maintained within the insertion member 1 upon disconnection from the mechanical device 9 . The insertion member 1 comprises vanes 19 which are designed to engage with a proctoscope and is threaded 20 at the distal insertion end in order to receive a threaded cap 8 having a blister packet 21 containing buffer. The mechanical device 9 is intended to be battery powered and may be re-charged by a power supply through a charging jack 12 . The mechanical device 9 comprises an air intake filter 25 , a rubberised handle 13 and also has an on-off switch 15 and light emitting diodes 10 and 11 which indicate when the device 9 is ready and when the cycle of first and second pressure applications are complete.
In use, a user holds the mechanical device 9 by the rubberised pistol type handle grip 13 and attaches the device 9 to an insertion member 1 . The insertion member is then inserted into the rectal cavity where it engages with a proctoscope using the vanes 19 which enables an improved penetration consistency. A first elevated pressure is applied by the user by pressing the trigger 14 which causes air to be drawn into the mechanical device 9 through the air intake filter 25 which is then compressed and causes the flexible membrane to emit from the distal end of the insertion member 1 to make contact with the colorectal mucosal surface. A second reduced pressure is then applied by the user by pressing the trigger 14 a second time which causes the flexible membrane to return to the interior cavity of the insertion member 1 . Once cell sampling has been completed, the insertion member 1 is disengaged from the proctoscope and the mechanical device 9 is detached from the insertion member 1 and the pressure within the insertion member 1 is maintained by way of the self-sealing valve 18 . A threaded cap 8 having a buffer containing blister packet 21 may then be screwed to a thread 20 on the insertion member 1 causing buffer to be released into the receptacle formed by the deflated flexible membrane. The mechanical device 9 can then be re-used by attachment to subsequent insertion members 1 .
Components Required for the Touch-Print Cell Sampling Technique
The components required for sampling exfoliated cells from a colorectal mucosal surface of a human subject are presented in FIG. 4 .
i) Access to the rectal mucosa can be achieved by the use of a rectal access tube 29 , which can be a modification of an existing instrument for rectal examination (e.g. rectoscope 22 ). The rectal access tube 29 consists of a rigid tube (with a handle) equipped with an obturator 30 providing an olive-shaped end and uninterrupted surface facilitating introduction of the rectal access tube 29 through the anal canal into the rectum.
ii) The cell sampling device 1 shown in FIG. 4 is substantially as described in FIG. 1 and has an external diameter compatible with the internal diameter of the rectal access tube, i.e. in the range of 15-20 mm.
iii) A source of compressed air 7 serves to provide a means for pressurisation of the interior cavity. The means for pressurisation 7 may comprise a syringe (as described in FIG. 2 ), an air pump (as described in FIG. 3 ) or a compressed air mini-container (mini-cylinder). Air pressure inside the cell-sampling device can be limited/ controlled by either using a fixed air volume (simple syringe solution) or by reaching a fixed air pressure level (a precision valve would be needed for this purpose).
iv) A bottle or tube with a specific buffer 35 (different buffers should be used for different purposes, such as DNA or RNA extraction or cell isolation/separation for further analysis).
v) A hermetic lid 8 for the cell-sampling device (needed for cell/protein lysis reactions if immediate DNA or RNA extraction is performed, for cell isolation procedures and, especially, for storage/transportation of the material if it is not immediately used, e.g. transportation from surgery/clinic to laboratory).
The components required for the procedure can be developed to be used as a disposable kit, which should include all the listed components except the compressed air source, which can be used repeatedly.
Description of the Touch-Print Cell Sampling Technique (Rectal Manipulations)
FIG. 5 shows an example of the touch-print cell sampling technique to sample exfoliated cells from a colorectal mucosal surface of a human subject using any of the devices shown in FIGS. 1-4 . This procedure is simple and no special training in proctology or endoscopy is required for the operator to carry it out. It can be performed by any qualified medical professional (GP, nurse etc.) at a local surgery or patient's home or it may even be self-administered by the patient.
FIG. 5A schematically illustrates a cross-section of the anatomy of the human rectum 28 , anal canal 26 and colorectal mucocellular layer 27 . It should be noted that any contact of the cell-sampling device with squamous epithelium of anal canal can result in both material loss and contamination of the sample with squamous epithelium of the anal canal.
The procedure commences with introduction of a rectoscope-like rectal access tube 29 with an obturator 30 in place into the rectum 28 ( FIG. 5B ). An appropriate lubricant can be used for the introduction procedure to facilitate it and to diminish patient's discomfort, which can be caused by this initial stage of the procedure.
Once the rectal access tube 29 is introduced ( FIG. 5C ) and the obturator 30 has been removed, direct access to rectal mucosa is achieved and the mucocellular layer 27 opens.
The insertion member 1 is introduced to the rectal access tube 29 so that the upper edge of the insertion member is located just above the edge of the rectal access tube ( FIG. 5D ).
A first elevated pressure is applied which inflates the collecting flexible membrane in order to contact the membrane with the rectal mucocellular layer 27 to provide touch-print cell sampling ( FIG. 5E ). The device is left in this position for approximately 10-15 seconds to achieve better adhesion of exfoliated cells and cell-derived materials of the mucocellular layer to the collecting membrane.
FIG. 5F shows the application of a second reduced pressure which deflates the flexible membrane and causes it to return to its initial position with collected material 31 on the outer, cell sampling surface.
The insertion member 1 is removed from the rectal access tube 29 and taken for further manipulations and analyses. The obturator 30 (a new re-lubricated one can be used) is reinstalled into the rectal access tube 29 , and the tube 29 is removed from the rectum 28 (see FIG. 5G ). The complete procedure (rectal manipulations) should take no more than a couple of minutes.
Processing of Collected Cells.
FIG. 6 shows an example of the steps which may follow the method depicted above for FIGS. 5A-5G which should be completed immediately after cell collection to avoid drying of the cell collection membrane. Step (a) shows cell-sampling device 1 with exfoliated cells 31 on the cell-collecting flexible membrane after cell collection. The top compartment of the cell-sampling device is filled with a fixed volume of a specific buffer 35 which lyses or suspends the exfoliated cells (Step (b)). Different cell lysis buffers or cell preserving mediums can be used for DNA or RNA extraction procedures, special buffers/mediums should be used for applications requiring cell isolation. The cell-sampling device is prepared for sample transport or storage by being hermetically closed with a secure threaded cap 8 (step (c)) but it will be appreciated that when the threaded cap has a buffer containing blister packet then step (b) can be omitted. The device can then be stored or transported for further downstream procedures for screening/diagnostic and/or research purposes (step (d)).
Analysis of Samples
It should be stressed that the technique provides a much higher degree of standardization in comparison with other existing approaches. The use of a standard device with standard air pressure/volume, standard area of inflated collection membrane (contact area with rectal mucocellular layer can vary, but this variation is negligible compared to other ways of obtaining exfoliated cells, e.g. stool-based techniques) and standard amount of buffer added after the cell sampling procedure create very favourable conditions for comparative analysis of either cell numbers or amounts of cell-derived substances (e.g. DNA).
(a) Analysis of Samples for the Purpose of Colorectal Cancer Screening
Colorectal cancer screening implies wide, population-based (age-defined) assessment of individuals presenting no complaints to reveal asymptomatic (in most instances—early) cases of the disease, timely treatment of which can reduce mortality caused by the condition. One necessary requirement for the method is its simultaneous applicability for thousands/millions of people.
i) Given that there are strong indications of considerably higher amounts of colonocytes and colonocyte-derived DNA in rectal mucocellular layer of colorectal cancer patients compared to tumour-free individuals, it is very likely that the technique of direct sampling of exfoliated colonocytes and colonocyte-derived materials can provide a simple screening test for colorectal cancer based on the direct quantitation of -the amount of DNA extracted from the cells. For this approach the initial buffer used just after cell sampling should be a cell lysis buffer used for the selected DNA extraction procedure. The addition of the buffer should provide efficient cell lysis and preservation of the DNA-containing material during transportation to a dedicated laboratory and (probably) some period of storage. The DNA extraction method should be selected on the basis of its applicability for high throughput analysis, i.e. it should be compatible with multichannel liquid handling robotic systems. Exact values for DNA quantities defining “positive”, “negative” and “doubtful” results of the test should be determined in clinical trials.
ii) Similar initial steps of DNA extraction can be applied for the analysis of molecular markers of colorectal cancer. Cells sampled by the touch-print procedure should provide a much better quality DNA compared to currently employed techniques of DNA extraction from stool samples. PCR amplification of this DNA can be done without precise quantitation of its amount. Multi-target molecular analysis is considered as an option in colorectal cancer screening, however it may be more time-consuming and expensive compared to direct quantitative analysis. At the same time DNA extracted for direct quantitation can certainly be used for PCR amplification in further diagnostic analysis of quantitatively “positive” or “doubtful” cases.
iii) In case of a need for specific isolation of colonocytes from cells of other types, separation methods (e.g. immunomagnetic or density gradient separation) can be applied to achieve a higher purity of colonocyte cell population for the analysis. For this purpose some cell-preserving media containing antibiotics (some bacterial presence in the collected material is impossible to avoid) and mucolytic agents can be applied. Isolated colonocytes can then be used for different types of analysis such as DNA extraction and quantitation, DNA extraction followed by PCR amplification, cancer molecular and biochemical marker analysis, cytological/cytochemical assessment, and direct cell counting (doubtful in terms of screening due to low speed and high cost).
(b) Colorectal Cancer Diagnosis
Diagnostic use of tests is focused on individuals presenting some specific complaints or already identified as sufferers from a condition. Target groups of patients are much smaller than those expected for screening purposes.
i) Direct DNA quantitation can be applied in individuals presenting complaints indicating possible colorectal conditions.
ii) DNA extraction followed by PCR amplification and molecular analysis can be useful both for confirmation of the initial diagnosis and for advanced diagnostic procedures (assessment of cancer aggressiveness, sensitivity to chemotherapy for metastatic tumours, prognosis etc.).
iii) Cell isolation can be used for both further molecular/biochemical analysis and cytological investigation (tumour cells with specific morphological features) can be easily found among exfoliated colonocytes in CRC patients. | A device for collection of exfoliated cells from the rectal mucosa comprises a hollow, cylindrical body having an inflatable and invertible flexible membrane attached to one end thereof. Applying positive pressure to inflate the membrane after the device is inserted, preferably through a rectal access tube, into the rectum causes exfoliated cells to be collected on the surface of the membrane. Before removal of the device, negative pressure is applied and the membrane, along with the collected sample of exfoliated cells, is deflated, inverted and withdrawn into the body of the device, thereby avoiding contact of the collected sample with body surfaces or the rectal access tube as the device is removed from the rectum. | 0 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method and apparatus for hazardous gas abatement and emission control. Contaminated gas is decomposed, cleaned and neutralized. The present invention is particularly useful for global warming gases and other hard to decompose gases. These gases may include perflourocarbons (PFCs), tetraflouromethane (CF 4 ), hexaflouroethane (C 2 F 6 ) and many other ozone depleting global warming and greenhouse gases. The present system is also useful for decomposing the exit stream of a semiconductor process by removing gases such as arsine (AsH 3 ) or phosphine (PH 3 ). High temperatures are required to clean, neutralize and decompose these types of gases.
[0002] Existing systems do not provide adequate heating to effectively cleanse exit gas streams of global warming gases. Previous gas cleaning systems include controlled decomposition/oxidation (CDO) and others. These previous systems suffered from low efficiency in performance and considerable downtime of equipment during maintenance. Industries, such as the semiconductor industry, have a considerable need for gas cleansing systems in order to comply with environmental emissions codes and regulations.
[0003] In existing gas cleaning systems heaters are used. However, the heaters insufficiently heat all of the gases, and the heaters become fouled and unable to efficiently transfer heat. They also become so burdened with particulate contaminants or reaction products as to interfere with free flow of gases through the cleaning systems. Periodic cleaning of the heaters and the chambers becomes necessary, which requires shutting down of the systems or taking the treatment apparatus off line, resulting in duplicate systems and greater expense. If the systems are not cleaned contaminated gases will be released.
[0004] Needs exist for improved apparatus and systems for cleaning heater compartments in contaminated gas treatment methods and apparatus.
[0005] Needs still exist for improved systems for neutralizing, pacifying and cleaning contaminated chemical process exhaust and waste gases.
[0006] Needs exist for improved systems, which efficiently neutralize chemical process exhaust gas hazardous components and contaminates. The system should ensure complete or substantially complete neutralization and pacification of any out flowing contaminant gas in the gas stream to be neutralized. Needs exist for systems that are simple and inexpensive to build and to operate and that do not require a fuel source to operate.
[0007] Needs exist for systems that are capable of handling spent process gas streams that have contaminate gas concentrations from trace to substantial amounts in volumes of cubic centimeters to several tens or hundreds of liters per minute.
SUMMARY OF THE INVENTION
[0008] The present invention is a hazardous gas abatement system for reacting global warming, greenhouse and/or ozone depleting gases using an electrical heater and a water scrubber. The present invention provides higher temperatures and increased contact surfaces for decomposing the subject hazardous gases when compared with previous systems.
[0009] Preferably, but not limited to, one or more, or about one to four top flow hazardous gas inlets introduce hazardous gases into a heater compartment where the toxic gases are heated to approximately 1100 C. The hazardous gases flow into the heater compartment surrounded by an outer heater. An inner heater is positioned with respect to the outer heater to create additional heat and contact surfaces for higher gas temperatures. An air inlet introduces air into the cleaning system separate from the hazardous gases. The air is fed around the outside of an external heater for cooling and dynamic oxidation. After the hazardous gases and the air are heated, the two gas streams flow downward in the apparatus and meet below the heater compartment. Oxygen in the air reacts with the heated hazardous gases. When the gases have reacted, the exit gas stream passes through a filter at the base of the cleaning device for removal of solids. A quick disconnect clamp on the bottom of the cleaning system is used to periodically remove the filter for cleaning and removal of accumulated solids. After passing through the filter, exhaust gases flow upward in a chamber outside the heater compartment and then through water spray scrubbers that cool and scrub the gases.
[0010] A cleaning ring with an eccentric shaft cleans the entry point of the hazardous gas inlets, the outside of the internal heater, and the inside of the external heater. An air cylinder drives the eccentric shaft up and down between the heaters and along the gas inlets. The cleaner removes particles from the exposed surfaces of the heaters as it moves. The cleaning ring has an inner and outer surface for cleaning the inner heater and outer heater simultaneously. When not in use, the cleaner is positioned above the first and second gas inlets and away from the passage of contaminant gases and oxygen. In addition to cleaning the surfaces of the heaters, the cleaner also cleans the entry points of the gas inlets to prevent buildups.
[0011] Preferably, but not exclusively, the heater compartment, outer heater and inner heater are cylindrical. The cleaner is annular and coaxial with the outer heater. An operator, offset from a center of the cleaning system, moves the cleaner between the outer surface and the inner heater surfaces. The operator is a reciprocation device extending from an end of the treatment apparatus and a rod extending into the heater compartment and connected eccentrically to the annular cleaner for extending in a space between the heaters as the reciprocating device moves the cleaner.
[0012] Water sprays are also used for cooling and scrubbing of exhaust gases. A water scrubbing zone is positioned after the filter, but before exhaust gas leaves the apparatus. Moisture may also be introduced in the hazardous gas inlet or heater compartment in the form of steam or water. This addition of moisture reduces contaminants and possible damage to the heater compartment and other components by converting fluorine gas to hydrofluoric acid.
[0013] The present invention efficiently neutralizes, pacifies and cleans contaminated chemical process exhaust and waste gases and allows for easy cleaning of the heater compartment. The present invention ensures complete or substantially complete neutralization and pacification of any out flowing contaminant gas in the gas stream to be neutralized. The system is also simple and inexpensive to build and to operate. The systems is capable of handling spent process gas streams that have contaminate gas concentrations from trace to substantial amounts in volumes of cubic centimeters to several tens or hundreds of liters per minute.
[0014] These and further and other objects and features of the invention are apparent in the disclosure, which includes the above and ongoing written specification, with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a side cross sectional view of the hazardous gas abatement system.
[0016] FIG. 2 is a side view of the hazardous gas abatement system.
[0017] FIG. 3 is a top view of the cleaning ring with eccentric shaft.
[0018] FIG. 4 is a top view of the hazardous gas abatement system.
[0019] FIG. 5 is a top cross sectional view of the hazardous gas abatement system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The present invention is a hazardous gas abatement system for reacting global warming, greenhouse and/or ozone depleting gases using an electrical heater and a water scrubber. The present invention ensures complete or substantially complete neutralization and pacification of any out flowing contaminant gas in the gas stream to be neutralized.
[0021] FIG. 1 is a side cross sectional view of the hazardous gas abatement system 1 . Contaminated gases that are in need of neutralization and pacification are taken from a process stream. The contaminated gases feed into the hazardous gas abatement system 1 through a top flow hazardous gas inlet 3 . The hazardous gas inlet 3 introduces the contaminated gases through an entry point 5 that is attached to a heater compartment 7 . In order to carry out the neutralization and pacification of the contaminated gas, the contaminated gas is heated to temperatures of approximately 1100 C.
[0022] An air inlet 9 introduces an air stream into the cleaning system 1 . Air is introduced near the top of the abatement system 1 . Both the contaminated gas stream and air stream may be pumped into the abatement system 1 or may be drawn into the system 1 by a slight negative pressure within the vessel.
[0023] The contaminated gases leave the entry point 5 and move into the top of the heater compartment 7 . Gas flow in the heater compartment 7 is in a generally downward direction. At least one electric heater 11 is located within the heater compartment 7 . A second electric heater 13 may also be present. Walls 15 and other devices control gas flow and provide support for structures within the heater compartment 7 . The contaminated gases flow downward through the heater compartment 7 , between the inner 13 and outer 11 heaters. The use of a second heater 13 creates a second heat source and increases contact surfaces to ensure higher gas temperatures. The electric heaters 11 , 13 heat the contaminated gases to remove some of the contaminants.
[0024] After entering the system 1 , the air stream flows downward between the external heater 11 and the heater compartment walls 17 . Dynamic oxidation occurs as the air flows around the external heaters 11 and the insulation on the heater 11 is cooled. The pre-heated air stream exits the region between the external heater 11 and the heater compartment walls 17 through vent 15 .
[0025] At the base of the heater compartment 7 , the contaminated gases exit the heater compartment 7 and mix with the pre-heated air stream. The two gas streams react to decompose the contaminated gases. At the base of the system 1 , a filter 19 removes reacted solids from the combined gas stream. The filter 19 is periodically removed for maintenance and to clean out accumulated solids by means of a quick disconnect clamp 21 on the bottom of the heater compartment 7 .
[0026] The filtered exhaust gases flow upward in a chamber 23 , outside the heater compartment 7 and inside the outer wall 25 of the apparatus 1 . Prior to exiting the abatement system 1 , the filtered exhaust gases pass through a system of water spray scrubbers 27 that cool the exit stream and further remove contaminants from the exhaust gas. After being scrubbed by the water sprays 27 , the substantially cleaned exhaust gases are exhausted through an exhaust vent 29 . The exhaust is composed of water vapor, air and cleaned gas.
[0027] FIG. 2 is an exterior side view of the hazardous gas abatement system 1 . FIG. 2 also shows components 31 , 33 , 35 that are used to secure an air cylinder 37 onto the top 39 of the abatement system 1 .
[0028] FIG. 3 is a top view of a cleaning ring 41 with an eccentric shaft 43 . The decomposition of the contaminated gases results in the buildup of a solid residue within the heater compartment 7 . The filter 19 captures and collects many of the solid particles created from the process. However, decomposition occur throughout the length of the heater compartment 7 , including along the exposed surfaces of the heaters 11 , 13 . As a result, solid particles form on the heaters 11 , 13 and reduce the heating efficiency of the heaters 11 , 13 . In order for the abatement system 1 to work effectively, the heaters 11 , 13 must be cleaned frequently to remove solid particles on the heaters. In previous systems, the process needed to be shut down and opened for cleaning. In the present invention, the heaters 11 , 13 can be cleaned without extended disruptions of the abatement system 1 .
[0029] In an embodiment of the present invention with one heater, the cleaning ring 41 has an outer surface 45 in close proximity to the internal surface 47 of the heater 11 . The outer surface 45 of the cleaning ring 45 is used to scrape solid particles off the heater 11 . The cleaning ring 41 is positioned above the hazardous gas inlet 5 when the cleaning ring 41 is not in use. This positioning keeps the cleaning ring 41 away from the passage of contaminant gases, preventing solid buildup on the cleaning ring 41 itself and preventing the cleaning ring 41 from disturbing the flow of gases in the heater compartment 7 .
[0030] During cleaning, the cleaning ring 41 is depressed from its initial position above the gas inlet 3 by the air cylinder 37 . The air cylinder 37 provides force necessary to propel the cleaning ring 41 along the sides of the heater 11 while scraping solid particulates off the heater 11 and down toward the filter 19 . In addition to cleaning the surface of the heater 11 , the cleaning ring 41 also cleans the entry points of the gas inlets 3 to prevent buildups that would stifle the flow of gases. The cleaning ring 41 proceeds down the inner walls 47 of the heater 11 until it reaches a stop 49 . The inner walls 47 of the heater 11 are designed such that the cleaning ring 41 scrapes solid buildup from the entirety of some of the walls 47 , but not all of the walls 47 . Part of the inner walls 47 are tapered 51 and extend below the stop 49 to prevent the cleaning ring 41 from becoming misaligned. When the cleaning process is completed, the air cylinder 37 retracts the cleaning ring 41 to its initial position.
[0031] In an embodiment of the present invention with multiple heaters 11 , 13 , a cleaning ring 41 has an inner 53 and outer 45 surface to clean an inner 13 and outer 11 heater of solid particles. The outer surface 45 of the cleaning ring 41 is in proximity to the inner surface 47 of the first heater 11 . The inner surface 53 of the cleaning ring 41 is in proximity to an outer surface 55 of the second heater 13 . The cleaning ring 41 encircles the second heater 13 . The cleaning process with multiple heaters 11 , 13 is similar to the cleaning process for a single heater 11 . An air cylinder 37 depresses the cleaning ring 41 until reaching a stop 49 . The air cylinder 37 then retracts the cleaning ring 41 to its initial position. The air cylinder 37 acts on the cleaning ring 41 through an offset shaft 43 .
[0032] The cleaning ring 41 with its eccentric shaft 43 is used to clean the entry point of the gas inlets 3 , the outside of the internal heater 55 , and the inside of the external heater 47 . The cleaning ring 41 removes particles from the heaters' 11 , 13 exposed surfaces as it moves. The cleaning ring 41 cleans the inner heater 13 and outer heater 11 simultaneously. There is no need to disassemble the abatement system 1 in order to remove solid particles from the heaters 11 , 13 .
[0033] FIG. 4 is a top view of the exterior of the hazardous gas abatement system 1 . In a preferred embodiment of the present invention, the heater compartment 7 , outer heater 11 and inner heater 13 may be concentric cylinders. As a result, the cleaning ring 41 is annular and coaxial with the outer heater 11 . An operator 43 , offset from a center of the apparatus 1 , moves the cleaning ring 41 between the outer 55 and the inner 47 heater surfaces. The operator 43 is a reciprocation device extending from an end of the treatment apparatus 1 and a rod extending into the heater compartment 7 . The operator 43 is connected eccentrically to the annular cleaner 41 for extending in a space between the heaters 11 , 13 as the reciprocating device moves the cleaning ring 41 . The cleaning ring 41 is placed in close proximity to the heater surfaces 47 , 55 to ensure adequate cleaning, but the cleaning ring 41 is not in contact with these surfaces 47 , 55 .
[0034] FIG. 5 is a top cross sectional view of the hazardous gas abatement system 1 . Water sprays 27 are used for cooling and scrubbing of exhaust gases. A water scrubbing zone is positioned after the filter 19 , but before exhausting the gases out of the apparatus 1 via the exhaust duct 29 . The introduction of water into the system helps to further scrub the contaminated gases and cools the exit stream. Moisture may also be introduced in the earlier in the cleaning system 1 in the form of steam or water. Water sprays 27 may be reconfigured to dispense water or steam into the oxygenator 5 as well as the exit flow region 23 after the filter 19 . This addition of moisture in the form of water or steam reduces contaminants in the hazardous gas stream. Moisture also reduces the possible damage to the heater compartment 7 and other components by converting fluorine gas to hydrofluoric acid. Hydrofluoric acid is less damaging to the equipment than fluorine in the gaseous form.
[0035] The present invention efficiently neutralizes, pacifies and cleans contaminated chemical process exhaust and waste gases and allows for easy cleaning of the heater compartment 7 . The present invention ensures complete or substantially complete neutralization and pacification of any out flowing contaminant gas in the gas stream to be neutralized. The system is also simple and inexpensive to build and to operate and does not require a fuel source to operate. The systems is also capable of handling spent process gas streams that have contaminate gas concentrations from trace to substantial amounts in volumes of cubic centimeters to several tens or hundreds of liters per minute.
[0036] While the invention has been described with reference to specific embodiments, modifications and variations of the invention may be constructed without departing from the scope of the invention. | A hazardous gas abatement system decontaminates an exit gas stream containing global warming gases using an electrical heater and a water scrubber. One or more top flow hazardous gas inlets introduce hazardous gases into a heater compartment. Air or oxygen is introduced into a separate chamber for dynamic oxidation and cooling. The streams are mixed and oxygen reacts with the hazardous gases. Solid particulates from the reaction are removed by a filter in a quick disconnect bottom chamber. Filtered exhaust gases flow upward in an exhaust chamber surrounding the heater compartment and through water spray scrubbers. A cleaning ring mounted on an eccentric rod cleans particles from the outside of the internal heater, and the inside of the external heater. An air cylinder drives the eccentric rod and cleaning ring down and up between the heaters and stores the ring above the gas inlets. | 1 |
FIELD OF THE INVENTION
The present invention relates to a high pressure, reinforced hose of rubbery, elastic material of the type used as dredge hose, dredge couplings, dredge discharge sleeves, oil lines, petroleum lines and the like.
BACKGROUND OF THE INVENTION
High pressure hoses of rubbery material have been made by sequentially winding alternate layers of a tape of a vulcanisable rubber and of rubber-coated textile fabric and/or metal wire or cord reinforcement on a rotating mandrel, the rubber and reinforcement layers thus laid down be in cross section distinctly laminar in appearance. Such a winding procedure is not only time consuming but it is difficult to apply compact layers of rubber because not much tension can be applied to the easily stretchable tape of unvulcanized rubber.
Moreover, couplings commonly employed on this type of hose comprise an integral outer metal collar and sleeve combination, the sleeve portion of which is built into the internal end bore at each end of the hose section during manufacture. Outer compressive bands or clamps are placed over each end of the hose in the region of the sleeves to assist in retaining the sleeves under internal pressure. Axial forces on the hose are transferred to the couplings and in the existing hose these forces are taken up largely by the outer compression bands. Hose of this construction to be used as dredge discharge sleeves (connector between dredge and floating dredge line) or as floating dredge lines per se require that the internal bore of the sleeves be lined with rubber to resist abrasion. Such lining must be applied by hand in a difficult operation, especially in the smaller hose sizes, at significant expense. Such dredge hoses under favorable service can carry a nominal pressure (burst) rating of 50 to 57 atm. But under unfavorable or severe service conditions, the combination of high internal pressure, and especially of high transient internal pressures exceeding the pressure rating, with twisting, extension and shearing forces exerted at the couplings tend to expel the coupling sleeves. When this happens, dredging must be terminated while the damaged discharged sleeve or hose section is replaced. Also the damaged section usually must be sent back to the manufacturer for repair. Under these conditions the maximum allowable working pressure of the hose may be as low as 20 atm. or less, whereas the hose body can easily be built to withstand much higher pressures.
Floating dredge hoses of rubber are now made having externally applied flotation collars so as to float without the usual pontoon supports. The action of tides, winds and waves on such floating lines often impose very severe strain on the couplings which sometimes fail at an unacceptable rate. These problems plus a tendency for dredging pressures to increase require significantly improved hose incoporating improved couplings.
SUMMARY OF THE INVENTION
The present invention provides both an improved high pressure hose having integral metal couplings bound to a pattern of continuous filamentary reinforcements extending throughout the hose body and a method of manufacturing such hose.
According to the present invention there is provided a high pressure hose having a body wall of rubbery material reinforced with windings of filamentary reinforcement and a coupling member at each end for assembly in use, wherein each such winding comprises a plurality of continuous lengths of said filamentary reinforcement arranged in a band-like grouping in side-by-side spaced disposition, with each such grouping being disposed helically with respect to the axis of the hose and extending back and forth successively through the body wall in successive runs at equal but opposite angles with respect to such axis. The said band-like groupings of filamentary reinforcement are secured mechanically to the coupling members at peripheral locations thereon which are physically outside of the circumference of the hose body, and the portions of said windings at the coupling locations are clamped and sealed by rubbery material to the respective coupling member.
Preferably, each of the couplings comprises an outer collar and an inner collar with one of the outer collars carrying a plurality of winding-retaining means arranged in a circle outside of the body of the hose, each of the band-like winding groupings being brought outwardly at each of its ends from the body of the hose to the winding retaining means at the same peripheral location with respect to the circumference of the hose body, and the collars at each end of the hose being clamped over the collar-engaged ends of the windings by a compressive force exerted in a direction parallel to the axis of the hose.
Further, each of the couplings preferably comprises an outer and an inner collar with the outer collar having a plurality of winding-retaining projections arranged equidistantly in a circle outside of the hose body wall and extending in a direction parallel to the axis of the hose, each end of each successive run of the band-like groupings of filamentary reinforcement being passed over the peripherally-corresponding winding-retaining projection at each coupling, and the band-like groupings of filamentary reinforcement being arranged in successive complete passes back and forth through the body wall with each successive complete pass being indexed over the peripherally-successive winding-retaining projections at each coupling collar to form a balanced filamentary reinforcing structure
Each of the inner collars preferably has its inner periphery shaped to provide a smooth transition of the band-like winding groupings from the circumferential to the outward direction and its outer periphery shaped to form a recessed bundle of rubber-encased windings over each of said collar projections.
In the high pressure hose according to the present invention, each said coupling member preferably comprises an outer collar carrying a plurality of bolt-hole sleeves rigidly secured thereto and arranged equidistantly in a circle outside of the hose body wall and extending in a direction parallel to the axis of the hose, the band-like winding groupings being passed back and forth through the body wall in complete passes with each end of each pass passing over the bolt hole sleeve at the same peripheral location at each coupling, and the outer and inner collars of each coupling being secured together by bolts passed through the sleeves and exerting on the sleeve-engaged windings a compressive force exerted parallel to the axis of the hose.
The hose of the present invention has a network of numerous filamentary reinforcements helically disposed to the axis of the hose, which reinforcements are continuous in character in the sense that each individual strand thereof passes back and forth through the body of the hose a plurality of circuits or passes with each of such passes mechanically engaging the coupling member at each end of the hose, and with the coupling engagements of successive passes being circumferentially progressively and regularly advanced about the coupling to form a balanced structure in which longitudinally exerted forces tending to separate the couplings from the hose body are taken up largely by tension in the filamentary reinforcements. A "circuit" or "pass" in the sense used herein is a band of reinforcements comprising a plurality of continuous filamentary reinforcements which can be considered to extend from its point of engagement with a first coupling or coupling member through the hose body at one helix angle to the other coupling at the corresponding circumferential engagement location there on and return through the body at an equal but opposite helix angle to the first collar at the predetermined circumferential engagement location thereon. The hose of the invention has a reduced tendency to twist in service due to its highly balanced filamentary pattern. The coupling engaged windings are clamped to each coupling by clamping means exerting a compressive force directed only longitudinally of the hose parallel to the axis and the resulting structure is vulcanised in place on the mandrel to produce a hose of solid reinforced rubber having integral filament bound couplings. After vulcanization there is in the hose of the invention very little, if any, residual tension in the pattern of filamentary reinforcement.
According to the present invention there is also provided a method of making hose of a rubbery material having filamentary reinforcement and a coupling at each end for assembly in use, which comprises, mounting a pair of coupling members in spaced-apart relation on a rotatable mandrel, each coupling having a plurality of circumferentially disposed winding-retaining means carried above the surface of the mandrel by a distance exceeding the thickness of the hose to built thereon, rotating the mandrel while applying thereto a composite winding including one above the other a layer of a rubbery tape and a plurality of continuous lengths of filamentary reinforcement arranged in side-by-side spaced relation to form a band, translating the point of application of said composite winding back and forth along the length of said mandrel between the coupling members mounted thereon to generate thereon a winding in one direction of travel at a helical angle with respect to the axis of rotation and at an equal and opposite helical angle in the return direction, the point of application of the composite winding being brought repeatedly over each coupling member to cause the composite winding to engage at least one winding-retaining means thereon and the rotation of the mandrel being indexed with respect to the translational movement of the composite winding to cause the composite windings to engage circumferentially successive winding engaging means on each round-trip pass of the composite winding, after the requisite thickness of windings have been so applied clamping the coupling retained ends of the windings to each coupling, and vulcanizing the resulting assembly in place on the mandrel.
Preferably, the added steps of winding a layer of rubbery tape only over the built-up body of composite windings to form an outer skin of rubbery material thereon and then clamping the coupling retained ends of all windings to the couplings and vulcanizing the resulting assembly in place on the mandrel, are included.
The outer collar of each coupling member may further be mounted on the mandrel as described and carry a plurality of winding-retaining means arranged equidistantly in a circle on a radius exceeding that of the hose to be built thereon, and the outer and inner collars of each said coupling member may be clamped together over the collar-engaged ends of the composite windings before the vulcanizing step.
In one embodiment of the present invention, the composite winding is a band of continuous monofilamentary metal wires located above with respect to the rubbery tape and signficant tension is applied only to the band of wires during the winding.
A layer of rubbery tape may be wound onto the mandrel both before and after the composite windings are applied.
In a further embodiment of the method of the present invention an added short reciprocatory motion is imparted to the winding supply in the region of each coupling so as to apply an extra winding between each helical pass, each such extra winding including an elliptically-shaped loop between each coupling winding engaging means carrying helical windings and a portion of the mandrel surface adjacent each coupling.
The method of the present invention produces such a hose by a winding technique utilizing a composite winding comprising a rubbery tape and a band of reinforcements comprising a plurality of continuous lengths of filamentary reinforcements arranged in a flat band and simultaneously wound on a rotating mandrel. A pair of coupling members are mounted in spaced-apart relation on such mandrel. Each such coupling member has a plurality of circumferentially-disposed winding engaging means which extend longitudinally parallel to the axis of the mandrel and are peripherally equidistant one from the other and located radially with respect to the mandrel outside of the body of the hose to be generated thereon.
The composite winding is created by bringing together a continuous length of a rubbery tape from a supply reel and likewise a plurality of continuous lengths of filamentary reinforcements arranged in spaced-apart relation as an essentially flat band. Preferably, the filamentary reinforcements are applied to the mandrel simultaneously with the rubbery tape. While either the tape or the band of filaments can be uppermost, there is a signficant advantage to the filaments being above the tape so that a significant tension taken only on the filaments during winding compresses the tape as it is applied. Windings thus applied stay in position more precisely on the mandrel and produce a tighter and more coherent mass of windings.
Winding starts by temporarily securing the end of the composite winding to one of the collar bushings, passing the starting winding under moderate tension downwardly to the mandrel surface where it is wound thereon as a helical progressing to the other end of the mandrel to a similar outer collar. The winding is brought outwardly and is passed circumferentially over one or more bolt hole bushings and from thence back down to the mandrel surface where it is wound thereon in a winding of equal but opposite helical angle to the initial run of windings and progressing back to the original or first collar. Retainer fingers or clips on the ends of the bushings temporarily retain the windings.
The winding step proceeds by translating the winding feed point or supply back and forth in a reciprocating motion over the surface of the mandrel defined by the coupling members. The mandrel is rotated and the rotation of the mandrel and the lineal rate of translation of the winding supply along the mandrel are synchronized so as to generate on the surface of the mandrel, in one direction of travel of the winding supply, a composite band-like winding oriented at the desired helical angle with respect to the axis of the mandrel and, in the other direction of travel, a composite band-like winding at an equal but opposite helical angle.
During the winding, the winding supply or feed point is brought at each end of its path of reciprocating travel over or adjacent to each coupling member so that the composite winding "picks up" a winding engaging means on the coupling member. In each complete back and forth "pass" of the windings, the pass starts and ends at the corresponding peripheral locations on both coupling members. The winding then procedes by indexing the next peripherally adjacent pair of winding engaging means until all such means have been picked up and equal number of main helical windings and a circumferentially balanced pattern of windings of the requisite thickness has been built up on the mandrel.
At the latter point in the procedure, it is usual to sever the reinforcements and continue the winding procedure with tape only to generate a rubbery outer skin on the hose body and over the windings on the couplings.
The process of the invention then involves a step of applying a clamp around the coupling engaged ends of the continuous windings and the procedure is continued by vulcanizing the thus assembled structure in place on the mandrel. The last step is to remove the mandrel from inside the hose body to obtain the finished hose.
In such hose there is very little, if any, residual tension in the pattern of filamentary reinforcement but the couplings are firmly and integrally bound to the filamentary pattern of reinforcements in the hose body. Forces exerted on the couplings in service tending to separate the couplings from the hose body are taken up by tension in the reinforcements and which forces, due to the helical nature of the windings, are translated largely longitudinally of the hose as opposed to radially.
Preferably, the hose structure and method of the present invention can be modified by applying extra short windings in the region of the couplings to stiffen the ends of the hose and strengthen the attachment of couplings to the hose body. Such extra windings can be interposed between each helical pass or between each of a selected number of helical windings.
The procedure involves the interposition of a series of short reciprocatory motions of the winding feed in the region of each coupling, preferably so as to "throw" an elliptically-shaped loop of winding between each winding engaging means on the coupling and around a portion of the periphery of the mandrel adjacent each coupling. Each winding engaging means on each coupling carrying helical windings is thus given a loop before the next helical run of the pass is continued. By definition an "extra winding" in this sense at each coupling member thus includes at least a number loops equal to the number of winding engaging means carrying helical windings.
A convenient way of applying these extra windings is to start the extra winding at one of the bolt hole bushings and pass it down to the circumference of the mandrel in an elliptical winding and back to the same bushing with the extra windings being then advanced in progression around the circle of bushings until an appropriate number and distribution of bushings have received an extra winding. As each main helical body winding is applied an extra winding can be wound on engaging the bolt hole bushing in a suitable radial progression.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be further described by reference to the accompanying drawings, in which:
FIG. 1 is an isometric side view of one end of a winding mandrel on which the hose of the present invention may be wound, the view showing how a rubber tape and a band of continuous filamentary reinforcing are brought together and simultaneously wound on the mandrel, a coupling member in the form of a collar mounted on the mandrel and having a circle of bolt hole bushings each carrying a winding pick-up finger or clip to serve as winding engagement members, how the windings of each winding pass are applied at equal and opposite helix angles, and how, in the embodiment illustrated, each pass of the windings engages a number of bolt hole bushings;
FIG. 2 is a partial sectional end view taken diametrically through the mandrel of FIG. 1 just inside of the coupling collar, the view showing the shape of the winding retainer fingers carried by the bolt hole bushings and in dash-dot lines how each successive composite winding engages successive bolt hole bushings;
FIG. 3 is a view showing a section through a completed bundle of windings over one bolt hole bushing;
FIG. 4 is a partial sectional side view through the coupling collar and mandrel, the view showing the shape of the strand-retaining fingers, the bolt hole bushing, a rubber facing adhered to the strand-contacting portion of the inner collar face, a rubber breaker of triangular shape applied to the surface of the mandrel just inside the collar, the inward movement of the outer collar, which is the result of helically turns of a rope winding under tension at the reinforcements starting at a point where the reinforcement is leaving the mandrel and ending when the angle A has reached 75° (A = 54° before rope applied).
FIG. 5 is a partial end sectional view similar to that of FIG. 2 showing in dash-dot lines how the direction of the windings is changed by rope winding on the reinforcements;
FIG. 6 is a view similar to that of FIG. 4 but with an inner clamping collar in place, the view showing how the inner collar is similarly provided with a rubber facing on its winding contacting face and how the inner periphery of the inner collar is shaped to encourage a smooth transition from the horizontal helical winding to the outward direction; and
FIG. 7 is a view similar to that of FIG. 6 but showing the completed winding assembly in place, a face plate and the bolts in place and tightened, an outer collar seal applied, and the assembly as vulcanized showing coalescence of the windings on the collars to an integral bundle of solid filament reinforced rubber.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1, 2 and 3 the manufacture of the hose according to this invention starts by mounting and securing a pair of outer collars 10 (only one shown) in spaced - apart relationship on a cylindrical rotatable winding mandrel 11. The collars 10 preferably are continuous collars rather than the split variety. Each collar 10 has a plurality of bolt hole bushings 12 swaged into a circle of bolt holes. Such bolt holes, it should be noted, are peripherally equidistant one from the other and located in a circle at a radial distance above the mandrel surface which is beyond the thickness of the hose to be built thereon.
Each of the bolt hole bushings 12 is provided with a retainer clip or finger 13 of retatively thin crushable sheet metal or plastic and which is swaged into the bolt hole along with the bushing 12. The outer upper end of each finger or clip 13 is tapered in a two-sided arc coming to a point to allow windings to slide smoothly into place over the bushing and avoid interference with the winding leaving the bushing. A facing 14 (FIG. 4) of unvulcanized rubbery material is adhered to the inner surface of each of collars 10 in their winding contacting areas. Each collar 10 also has a recessed circle 15 on its outer surface into which a circular sheet of rubber 16 (see FIG. 7) is fitted after winding is completed. As will be noted, rubber sheet 16 is laid on the surface of mandrel 11 and collars 10 are installed thereover so as to have their inner peripheries coated with rubber not only as a pressure seal but also to protect the metal of the collars against abrasion. Lastly, an extra breaker band 17 of triangular shape and composed of unvulcanized hose body stock is applied over sheet 16 just ahead of each collar 10 to fill the gap between the reinforcements and outer collar.
As is shown in FIG. 1, a composite winding 20 is formed by bringing together a strip or tape 21, for example 200 mm wide by 1.5 mm thick, of a vulcanisable hose body rubber composition and a plurality of individual wires, filaments or cords 22 from suitable supply spools (not shown), the tape 21 being brought over an idler roll 23 and the wires 22 being brought first to a slotted comb-like guide element 24 having an individual slot for each wire 22. As few as two to as many as 100 or more of wires 22, more preferably between 6 and 50 (e.g. 20 to 50) wires 22, are thus brought together in uniformly spaced-apart relationship to form a flat band of wires. The tape 21 and the band of wires 22 converge until the wires 22 are laid on the top surface of the tape 21 and may be at least loosely adhered there to by the natural surface tack of unvulcanized rubber. Such composite winding 20 thus formed will usually carry from about 4 to about 20, for example from about 4 to 8, wires per centimeter of its width.
The winding procedure usually begins either by applying a continuous sheet 16 of rubber over the surface of the mandrel by hand lay-up procedure or by winding the rubber tape on the mandrel until the requisite thickness 16 of rubber is built up. In either case, the collars 10 are then installed and aligned on the mandrel 11 with their bushings 12 in alignment. The triangular breaker band 17 of unvulcanised rubber will be applied over sheet 16.
The winding procedure then continues by securing the end of composite winding 20 to one of the bolt hole bushings or sleeves 12, for example by wrapping the winding several times around the sleeve and/or by forcing the end thereof inside the end of one of the sleeves. A very significant tension is taken on each wire portion of the composite winding 20, for example, a force of one to four kilograms with the lower tension used if the tape is warm and the higher tension if the tape is cold. The mandrel is then put into rotation while simultaneously the winding feed is translated down the length of the mandrel towards the other collar 10. The rate is rotating the mandrel 11 and the lineal rate at which the winding 20 is moved or translated down the mandrel must be synchronised so as to generate a band-like winding 30 on the mandrel 11 (see FIG. 1) of the correct helical angle with respect to the axis of rotation. No means for doing this is shown since both filamentary winding techniques and filamentary winding machines embodying the requisite controls are equally well known and, morever, the machine forms no part of the present invention. The winding procedure can be carried out manually by a skilled operator.
When the composite helical winding 30 reaches the region of the opposite collar 10, the winding 20 is picked up by one of the fingers 13, which directs it over the associated bolt hole sleeve 12. The direction of translation of the composite winding 20 then is reversed and winding then progresses back towards the first collar 10 laying down the second half 30 of the complete pass at an equal but opposite helical angle. At the first collar the winding is picked up and passes over the same bushing on sleeve 12 from which the round trip pass originated. Winding then continues with a peripherally successive pair of bushings 12 being indexed for each pass. The peripheral indexing of successive passes produces a natural slight overlap of the edges of each pass.
As appears in FIG. 3 a great many such passes engage each of the bolt hole bushings 12.
While the winding procedure can employ any reasonable helix angle, it is greatly preferred to employ an angle of 53° to 55° (e.g. about 54° ) with respect to the axis of rotation since such an angle is most efficient in translating radially expansive forces to longitudinally directed tensional forces in the wires 22. It should be noted that, as originally applied, the windings in the region of the collars 10 describe an appreciable angle "A" (see FIG. 4) with respect to the longitudinal surface of the mandrel 11. As will be seen later on, such angle is considerably increased when an inner collar is attached and the windings clamped between the collars. The increase in angle can be seen by comparing FIG. 4 with FIG. 6 where the outer collars are shown to move toward each other under clamping action.
It should also be noted that both the structure of the hose and the procedure of the present invention may be modified so that each pass of the helical windings engages only one bolt hole sleeve 12 (as is shown in FIGS. 2 and 5) or each pass can engage 2 or more bolt hole sleeves 12, as is shown in FIG. 1. When each winding passes over a plurality of sleeves 12, the "bundle" of windings becomes larger as the number of sleeves included in each pass is increased. It is thus necessary to provide coupling collars having numbers of winding engaging means (i.e. sleeves 12) somewhat conditioned on the thickness of the hose body to be generated and to engage each winding pass with a selected number of such engaging means or sleeves 12 to provide a bundle of windings which can be recessed between the collars. However, a given collar design can be employed on hoses of a range of thicknesses by varying the number of sleeves engaged by each pass or even by skipping sleeves on collars having too nummerous and closely-spaced sleeves.
It also will be appreciated that, at the completion of the winding procedure, the filamentary pattern generated in the hose body is not laminar as in prior art hoses built by sequentially applying reinforcing and tape layers. Rather the filamentary pattern is criss-crossed so frequently that in section the filamentary dispersion in the vulcanised hose appears almost randomly uniform, see the section through the bundle in FIG. 7. Moreover, since each winding pass contains a plurality of continuous filaments all of which are secured to each respective winding engaging means on each collar, breakage of one or more of the individual filaments or wires in the same pass has a relatively minor effect on the strength of attachment of the couplings.
After the requisite thickness of composite helical windings 30 has been built up on the mandrel surface, the filaments or wires 22 are severed, the wire ends thus obtained secured to a winding engaging means to tie it down and the winding of tape only continued to build up a rubbery outer skin on the hose of the desired thickness.
The tape only winding is also applied to the outside of each outer collar 10 to fill the circular recess 15 with solid rubber. The rotation of the mandrel is then stopped. The installation of the inner collar can be facilitated by wrapping a rope or cable 31 tightly around the finished windings at each end of the hose and adjacent the triangular breaker strip 17 (FIG. 4). A number of tightly wrapped turns 31 of rope causes the outer collars 10 to move inwardly increasing the angle of the windings passing over the sleeves 12 somewhat and inducing sufficient slack in the windings to admit the inner collar. Subsequently the wrappings 31 are removed and an inner collar 40, in this case most conveniently of the split variety, is mounted over the mandrel 11 inside each outer collar 10. A collar-shaped face plate 41, also of the split variety, is then placed over each end of the mandrel 11, outside of the outer collar thereon, and bolts 42 inserted through the face plate 41, the outer collar 10, and inner collar 40.
The bolts 42 and nuts 46 are then uniformly and gradually tightened. Note in FIG. 4 how the rope wrappings 31 cause inward movement of the outer collars 10 and, in FIG. 6, how the collars 18 are moved still further inward towards each other. The fingers 13 are crushed by the clamping action of the collars. As will be seen also in FIG. 6 the inner collar 40 has a facing 43 of unvulcanised rubber on its winding contacting surfaces, for example adhered by a good adhesive to prevent filament-collar contact and insure a better seal of the winding bundles. Note also in FIGS. 6 and 7 how the inner peripheral corner 44 of inner collars 40 is gently rounded to avoid kinking of the filaments 22. The inner periphery of each inner collar 40 is angled sharply away from the rounded peripheral corner 44 to form a collar anchor surface 45, the purpose of which appears below. The outer peripheral portions 46 of inner collars 40 are thinner than the inner peripheral portions to provide room for a recessed bundle of windings. The inner collar has a certain profile designed for the following reason:
FIG. 4 shows the length and direction of the first (C-E) and the last (C-D) reinforcement layers.
The length of these two layers is shorter than the length of the layers in FIG. 6, length CD' and CE'.
By completing the assembly of the end coupling members the wires of the reinforcement layer will be stretched. Any wire will be stretched. By vulcanising the hose any wire of the reinforcement layers will become without any stretch. Thus by a hose in service any wire of the reinforcement will carry over the same tensile load to the coupling.
After completing the assembly of the end coupling members, tape only winding is resumed to build up an edge seal 50 (FIG. 7) between each pair of collars 10, 40 and a thickened rubbery band or anchor 51 encasing each inner collar 40 anchor surfaces 45. Anchor 51 may also be an extruded strip. The thickness of the resulting rubbery anchor 51 helps hold the coupling, spreads the load imposed by twisting at the couplings and increases sealing of the inner collars 40. The hose structure is now complete.
The next step in the procedure is, winding nylon tape 71 around the assembled hose with a large pitch. This will be done two times. After winding the nylon tape, a rope is coiled on the assembled hose with a certain force to make a body for free vulcanisation. Now the completed hose structure is vulcanized in place on the mandrel. This is usually done by placing the mandrel and the assembled hose in a hot air oven or in an open steam autoclave. The vulcanization is carried out at any temperature conventionally employed ranging from 150° to 225° C.
The last step is to remove the mandrel from the hose after the assembly has cooled.
In the hose of the present invention, the couplings are an integral part of the hose and are retained by tension in the wire reinforcement layers. The hose of this invention retains its couplings at any pressure up to 75 atm. or more which the hose body can be built to withstand. An experimental hose of i.d. 200 mm. built by the method described failed in the hose body at 50 atm. due to a defective cord angle in a portion of the body but the couplings held.
The hose of the present invention can be built of any rubbery material but preferably is built employing an unvulcanized tape made of a vulcanisable rubbery material based on any of the natural and/or synthetic rubbers. Synthetic rubbers which may be thus utilised are SBR, cis-polybutadiene, cis-polyisoprene, the oil-resistant synthetic rubbers such as neoprene and the butadiene/acrylic nitrile ("nitrile copolymer) rubbers, EPDM terpolymer (ethylene/propylene/diene) rubbers, butyl rubber, and many others. The rubber of the tape may be compounded by conventional techniques for the properties needed in the hose. It may be desirable to employ tapes of different rubbery composition in the various parts of the hose, for example, the tape only winding first applied to the mandrel surface can be of a special high abrasion composition or of an oil-resistant rubber composition whereas the tape employed in composite internal windings can be of a softer or tackier formulation having good flow or knitting action during vulcanisation and the tape only windings applied as the outer skin of the hose can be specially formulated of degradation-resistant or weather-resistant butyl or EPDM rubbers.
The reinforcement employed in the hose and method of this invention can be any filamentary reinforcement ranging from mono-filaments or monofilamentary wires or braided or twisted multi-filamentary cords of naturraly-occurring fibers, synthetic fibers, plastic or metals of many kinds. Metal reinforcements are preferred, and most preferred are mono-filamentary forms of iron and steel wire. The filamentary reinforcement, whatever its form and composition, is also preferably surface treated to increase its adhesion to rubbery materials as is well-known good practice in rubber technology. The filamentary reinforcement may be encased in or pre-coated with rubbery material before its incorporation in the composite windings of this invention. Most preferred reinforcing material is bare mono-filamentary wires of steel which have a brass plated coating for good adhesion to the rubber.
The hose as described may be built using any filamentary type of reinforcement including any metal wire or braided metal wire cord reinforcement members, rayon, nylon, aramide, polyester, glass fiber, etc. The reinforcements can be monofilamentary in character or may be braided as a cord. Un-braided metal wires of iron or steel are preferred. The surface of the metal on the reinforcement is preferably treated for good adhesion to rubber as is conventional in metal reinforcements in rubber articles, e.g. radial steel auto and truck tires. The wire reinforcing members may be applied to the mandrel either with or without a rubber coating on the metal but it is preferred to use bare wire. | A pair of coupling collars are fixed on each end of a tubular mandrel. Each such collar carries a plurality of fixed bolt-hole sleeves projecting in a direction axially of the hose. Layers of rubber tape and continuous steel reinforcing cords are sequentially wound in a helical fashion on the mandrel and at the collar are brought radially out along the collar and circumferentially over at least one of the bolt-hole sleeves before passing back over the next tape layer to the other collar where the collar securing winding is repeated and so on until the required structure is built up. After the final outer tape layer is in place a split collar is placed over the hose and bolted on the inside of each of the fixed outer coupling collars to clamp the windings in place. The section is finished off by laying down tape layer seals over the area between the collars. The mandrel with its green hose section is then kettle-cured. Before shipping, polyurethane foam filled float collars of ABS are attached to the section.
In this system of installing couplings, the outer coupling collars are held in place by the tension in the continuous cords. | 5 |
This application is a continuation-in-part of our copending U.S. application, Ser. No. 460,918, filed Apr. 15, 1974 and now abandoned.
This invention relates to an improved process for making paper. More particularly, it relates to a process in which the improvement concerns the mitigation or complete avoidance of " wet press picking" (or buildup on the wet presses) as commonly occurs on industrial paper machines.
When a web is first formed on the wire or otherwise in a papermaking process, it thereafter is threaded over and under or between more than a dozen rolls including press rolls, drying and calendering rolls. As the web approaches the press rolls it contains large amounts of water which previously served to carry the paper fiber for web formation, and considerable amounts of this water are removed by the action of press rolls operating in pairs, a top roll and a cooperative bottom roll. In usual practice, the wet web is carried on a felt through the nip of two or more pairs of press rolls, as well as a pair of rolls commonly referred to as the " smoothing press" which, together with the press rolls, constitutes the wet press section of the paper machine. The web then enters the dryer section of the paper machine immediately following the smoothing rolls.
The web makes direct contact with the upper press rolls and it is at this point that a problem termed "wet press picking" (or buildup on the wet presses) is often developed. The press rolls nearest the headbox are often referred to as "wet" press rolls in the industry. For convenience, the term "press rolls" as used herein will generally designate "wet" press rolls, as well as the smoothing press rolls. The bottom press rolls may be slotted or vacuum equipped for improved dewatering and, as previously indicated, covered by an endless moving felt to absorb water from the web.
The problem of wet press picking is manifested wherein small agglomerates of fibers from the web, with or without pigment or other particles (at times, just barely visible to the naked eye) are picked up from the web and attach themselves to the surface of the press rolls which come in direct contact with the travelling web. The deposited particles in turn create an obstruction on the press roll surface sufficient to detach a small portion of web from the moving web surface, constituting a singular point of wet press picking. The press roll turns at high speeds, and it is understandable that the picking may be repeated at localized areas of the press roll and in many cases the progressive buildup may be serious enough to cover the entire contacting surface of the roll. In extreme cases, the tacky roll surface may cause the moving web to follow and wrap itself around the roll resulting in a web breakage and considerable downtime. Even in less extreme cases, the surface of the paper will be generally gouged or badly disrupted causing serious quality problems.
The main cause or causes of web press picking have not been identified with any certainty. It is known, however, that a number of factors tend to initiate, contribute or aggravate the problem. Among these factors are included: (a) origin and type of pulp with hardwood pulps generally being more susceptible to wet press picking, (b) operating with little stock refining or web moisture outside of a prescribed moisture range, (c) impurities such as residual pulping impurities, pitch, slime or foam in the papermaking furnish (or feed stock), and (d) the inclusion of various additives in the stock slurry prior to sheet formation, particularly high concentrations of rosin or other commercially supplied sizing agents, as well as relatively high concentrations of polymeric binders and other chemical additives.
Various measures have been contemplated by the industry in recent years for dealing with wet press picking. To correct wet press picking according to recent prior art, most often the press roll would be equipped with a doctor blade and/or water shower. Such measures are not fully effective, however, and the use of a water shower also introduces undesired moisture to the web. Use of press rolls of various surface compositions, for example, specially compounded hard or soft rubber, granite or stone, polymer coated or filled plastic surfaces, have also been tried in an attempt to overcome the problem, but none have resolved the problem and no definite conclusions as to the superiority of one composition over another have been reached. Machine grinding of the rolls to effect special surface characteristics have also proven to be unsuccessful. The addition to the feed stock of extra amounts of alum over that ordinarily used has been found to reduce picking at times, but the procedure is not generally reliable and may actually create more picking under certain conditions. Careful control of operating conditions, within limits imposed by specific manufacturing objectives, can alleviate the problem, but not fully eliminate it when it arises. These measures include maximizing fiber refining and retention characteristics in the sheet-forming process, optimization of vacuums, draws and other machine variables, etc. Certain materials including, for example, natural gums, various pitch dispersants, talc, sequestering agents, etc. added to the furnish have provided only modest improvements in some cases. On an industry basis, wet press picking is still a common occurrence and none of the attempts to correct the picking can be said to be fully successful in eliminating the problem.
DESCRIPTION OF THE INVENTION
I have now discovered that wet press picking is substantially mitigated or essentially eliminated when a specified polymeric siloxane is added to the feed stock in a specified concentration range in accordance with the process of this invention. Moreover, the prevention of wet press picking in this manner is independent of the composition of the press roll or its surface characteristics. The process has been found successful in papermaking conditions employing high or, alternatively, low concentrations of alum or sizing agents. The process is not dependent on the source or type of pulp used in the feed stock, the presence of other additives, etc.
The principal object of this invention is to provide an improved process of making paper wherein wet press picking is substantially or completely eliminated so that it no longer presents a problem to the paper maker under normal papermaking conditions.
The principal object of the present invention may be accomplished by reference to the following detailed description.
The polymeric siloxane additives useful in the process of this invention are of two classes: (A) a fluid, water-soluble copolymer of dimethylpolysiloxane-polyoxyalkylene ether wherein the alkylene moiety may be ethylene, propylene or mixtures thereof. Examples of this copolymer available commercially are the products designated "SF-1066" sold by General Electric Company and "L-7001" sold by Union Carbide Corporation, and (B) an aqueous emulsion of dimethylpolysiloxane or self-emulsifying mixture of dimethylpolysiloxane and surfactant. The emulsified dimethylpolysiloxane must remain water dispersible in all proportions. Examples of useful dimethylpolysiloxane emulsions commercially available are the products designated "SM-2061" sold by General Electric Company; "LE-466" sold by Union Carbide Corporation; and "HV-490" sold by Dow Corning Corporation.
As to their actual use, the polymers are preferably diluted with water and thereafter added to the headbox or stock preparation system containing cellulose fibers and other papermaking ingredients to provide an amount ranging from about 0.005 to 0.15%, preferably 0.01 to 0.05% of siloxane polymer based on dry fiber weight. When sizing agents, strength additives, or retention aids are used in the stock, the siloxane polymer may be added in appropriate amounts directly to aqueous dispersions of these materials which, in turn, are subsequently added to the headbox or stock preparation system. The aqueous siloxane dispersions may also be sprayed on the web as it travels over the forming wire. The manner of addition is of no serious consequence, it being necessary only to see that the siloxane polymer is uniformly present in the stock in the required concentration prior to the web entering the press section of the paper machine.
It is to be noted that since these aqueous siloxane dispersions are chemically and electrochemically inert in the stock system and are also added to the paper stock during the "wet end" portion of the paper making operation, most of the siloxane is released in the plant effluent and little, if any, of the siloxane polymer is actually present in or on the final dried paper. Although measurement of such small quantities of polymer is virtually impossible, it is estimated that, at most, approximately one-quarter of the initially charged polymer is present in the paper after the drying is completed.
It is also noted that the addition of the polysiloxane polymer within the specified concentrations does not affect other variables in the papermaking process. Thus, the polymer has no deleterious effects on the properties of the resultant paper, for example, strength, porosity, smoothness, printability, optical properties, and the like, since measurements of these properties show them to be within established statistically variable limits for untreated paper products.
The invention will be more fully illustrated by the examples which follow representing specific embodiments of the invention and is not to be construed as a limitation thereon.
EXAMPLE I
A series of tests were conducted on a Fourdriner paper machine wherein the press section consisted of two main presses followed by a smoothing press, each press consisting of a top and bottom roll. The first press consisted of a straight-through plain press with a standard rubber covered top roll typically used in the industry and the second press was a plain reversing press with a composition ("Microrok") covered top roll, also typically used in the industry. The smoothing press consisted of a straight-through set of rolls with a "Press-Tex" metal surfaced top roll and composition covered ("Micromate" ) bottom roll. The basic papermaking furnish consisted of a very lightly refined mixture of approximately 80% bleached hardwood kraft pulp and 20% bleached softwood kraft pulp.
Additives noted below, commonly used in paper making operations to impart sizing and strength, were added continuously to the stock preparation system and a sheet of paperboard was formed at approximately 123 lbs. per 3,000 sq. ft. basis weight. When equilibrium conditions were reached, two polymeric siloxane additives of this invention (as further identified below) were diluted to 1% solids and added continuously to the stock system in concentrations specified in the following table. Build-up due to picking was ascertained under the indicated conditions on each of the press rolls and noted in descriptive terms: none, slight, moderate, heavy, etc. The finished paper was tested in terms of its physical properties.
Table I__________________________________________________________________________ Buildup Noted After Running 15 Min. SmoothingStock Conditions 1st Press 2nd Press Press__________________________________________________________________________(1) Base sheet - No additives Moderate Slight Slight(2) 0.6% Alum added Slight Slight Slight(3) 1% Rosin + 2% Alum added Moderate Slight Moderate(4) 0.5% Starch added Moderate None Slight(5) 0.25% Synthetic Size* Heavy Moderate Heavy+ 0.25% Alum added(6) 0.25% Synthetic Size* Very heavy Heavy Very heavy+ .05% caustic added(7) 0.025% Dimethylpoly- None None None siloxane/Polyethyleneoxide polypropyleneoxide copolymer (SF-1066) added to stock condition (5)(8) 0.01% Dimethylpoly- None None Slight siloxane/Polyethyleneoxide polypropyleneoxide copolymer (SF-1066) added to stock condition (5)(9) 0.025% Dimethylpoly- Slight Slight Slight siloxane/Polyethyleneoxide polypropyleneoxide copolymer (SF-1066) added to stock condition (6)(10) 0.025% polydimethyl- None None None siloxane emulsion (SM-2061) added to stock conditon (5)(11) 0.01% polydimethyl- None None Slight siloxane emulsion (SM-2061) added to stock condition (5)__________________________________________________________________________ *alkenyl succinic anhydride
The concentrations of the various ingredients listed in the above table are expressed in terms of percent active ingredient by weight of dry pulp.
The above results clearly illustrate the improved results with respect to wet press picking obtained with the use of two polysiloxane polymers typical of this invention under various conditions contrasted to a number of stock conditions in which no polysiloxane polymer was added.
Subsequent physical testing of all paper produced in terms of strength factors, sizing, porosity, surface characteristics, etc., showed no statistically significant differences due to the addition of the siloxane polymers. In order to illustrate the fact that there were no statistically significant changes in physical property, the water resistance (sizing properties) and Mullen burst strength of the samples produced in Sample 5, 7 and 8 were tested.
Water resistance was measured using the TAPPI standard method T441os-69 wherein the amount of water absorbed by the sheet over a period of two minutes was measured. The values obtained, designated Cobb size values, are shown in grams/sq. meter. Measurements are taken on both the top (felt) and bottom (wire) sides of the paper. In this testing procedure, lower Cobb values indicate higher water resistance.
The Mullen Burst Strength was measured using ASTM testing method D774-67. According to this method a sheet of the paper is clamped between two ring shaped platens, thus leaving an exposed circular surface of paper under which there is an inflatable rubber diaphragm. As air is pumped into this diaphragm it expands and comes into contact with the exposed surface of the paper. Note is made of the pressure in p.s.i., at which the diaphragm caused the paper to burst.
Higher values indicate stronger paper. The values are shown in p.s.i.g.
______________________________________ Mullen BurstSample Stock Conditions Cobb Size Strength______________________________________ (felt/wire)5 0.25% Synthetic size 31/32 35.0 (alkenyl succinic anhydride) + 0.25% alum added7 0.025% Dimethylpolysiloxane/ 34/36 34.0 polyethylene oxide poly- propyleneoxide copolymer (SF-1066) added to stock condition (5)8 0.01% Dimethylpolysiloxane/ 31/34 35.0 polyethyleneoxide poly- propyleneoxide copolymer (SF-1066) added to stock condition (5)______________________________________
Although there were minor variations presented above, they are within the range of experimental error and the limits of the tests and there were no statistically significant variations in water resistance or strength between the samples prepared with the polysiloxane in the stock system and those prepared without the additive. Thus, the fact that in the Cobb size test, higher amounts of siloxane yield apparently poorer water resistance (and is therefore in fact contrary to what would be expected) is considered to be due to the experimental error and imprecise nature of the test.
EXAMPLE II
In order to show that addition of the particular polysiloxanes of the present invention in amounts as high as 0.15% based on the dry film weight have no sizing effects on the final paper, handsheets were prepared and tested as follows.
Sheets were prepared according to TAPPI standards using bleached kraft of 50 lb./3000 sq. ft. basis weight, adjusted to pH 6 with alum. All the sheets contained 0.2% of the alkenyl succinic anhydride synthetic size and 0.03% of a cationic retention aid. Sheets were tested immediately after drying and again after one hour cure at 105° C.
In comparing the water resistance of these sheets, use was made of a dye test employing crystals of potassium permanganate and an acid ink penetration test. In the dye test several crystals of potassium permanganate are placed on the upper surface of a swatch of test paper which is then set afloat in distilled water at room temperature. As the water is absorbed into the paper the crystals are moistened and impart a characteristic deep violet color to the paper. The time measured in seconds required for an end-point where three colored spots first appear on the paper surface is noted and is in direct relation to the water resistance since a more water resistant paper will retard the moistening of the permanganate crystals which had been placed upon its upper surface.
The acid ink penetration test is a comparison test wherein a swatch of test paper is floated in a dish of acid ink (pH 1.5) at 100° F. and the time measured in seconds required for the ink to penetrate through the paper to reach an end-point where about 50% of the paper is colored is noted.
The following table presents data on the various paper sheets which were compared in the described testing procedures.
______________________________________ Acid Ink Penetration KMnO.sub.4 (Time in Seconds) (Time in Uncured Cured Seconds)______________________________________Sheets containing no 65 60 62silicone (control)Sheets containing 0.15% 62 62 66dimethylpolysiloxane/polyethyleneoxide poly-propyleneoxide copolymer______________________________________
Since the above tests are considered to be valid within a tolerance of ± 10%, it is seen that there are no statistically significant sizing effects apparent from the use of up to 0.15% of the polysiloxanes of the present invention.
Summarizing it is seen the invention provides an improved process for making paper essentially eliminating the problem of wet press picking by use of specified polymeric siloxane additives. Variations may be made in materials, proportions and procedures without departing from the scope of this invention. | An improved process for making paper is described which improvement concerns the mitigation or avoidance of a commonly occurring problem in the industry termed "wet press picking" by means of specified polymeric siloxane additives. | 3 |
TECHNICAL FIELD
[0001] This invention pertains to mathematical models for on-vehicle determination of the remaining useful life of its automatic transmission fluid. More specifically, this invention pertains to the development and use of a combination of a temperature-based oxidation model and a friction model based on transmission gear shifts for determining remaining useful life of the fluid.
BACKGROUND OF THE INVENTION
[0002] Automatic transmissions have long been employed in automotive vehicles for transmission of engine torque to the drive wheels of the vehicle. These transmissions are controlled to execute shifting between several gear ratios depending on engine speed and operator commanded vehicle speed. Automatic transmissions have used a hydraulic fluid for transmission of torque between rotating driving and driven members of the device. This automatic transmission fluid (ATF) is subjected to considerable shear forces in the operation of the torque converter and transmission.
[0003] Automatic transmission fluids typically comprise a base oil with additives to slow thermal degradation of the oil. An ATF is heated due to the energy that is put into it during operation of the torque converter and transmission as well as heat from the engine compartment environment. The fluid may experience temperatures of 160° C. or higher. Over the past decades, vehicle manufacturers have recommended ATF change intervals of 50,000 miles, 100,000 miles, or fill for life depending on severe, normal or mild operating conditions, respectively.
[0004] Now the trend in vehicle requirements is for smaller sump transmissions, more aggressive shift calibrations and lower cooling capacity. These requirements mean that an ATF may experience a more severe operating environment, resulting in faster degradation due to oxidation and high shift energy input. These more severe demands on the fluid may require shorter, less predictable change periods. Accordingly, it is an object of this invention to provide a method for on-vehicle computer execution for predicting the end of the useful life of a vehicle's ATF and for advising the vehicle operator to change the fluid.
SUMMARY OF THE INVENTION
[0005] This invention provides two mathematical models that are conducted in parallel on an electronic transmission control microprocessor to determine the remaining useful life of a vehicle's transmission fluid. The models are suitably incorporated into the transmission computer controller, which is already programmed to control the operation of the transmission in response to driver commands. Such a transmission controller may be part of an engine/transmission powertrain control module (PCM). In accordance with the invention, two ATF models are used in parallel to better assess the state of the ATF without impairing the efficiency and responsiveness of the microprocessor.
[0006] One of the models is an oxidation model starting with an experimentally-determined life of the specific ATF composition. The oxidation model tracks the temperature experiences of portions of the ATF in different parts of the transmission to project (i.e., calculate) the remaining useful life of the bulk fluid. The other model is a friction degradation model that continually tracks current transmission shift energy, at the current bulk fluid temperature, imparted to the fluid for each upshift/downshift of the transmission. For many fluids it is necessary or desirable to consider both the oxidation of the bulk oil and its friction properties to reliably determine its remaining useful life. When one of the two models first determines that useful fluid life has been depleted, the vehicle operator is advised to change the ATF. These two models complement each other both in reliably estimating the remaining useful life of the fluid and in efficient use of the PCM.
[0007] The bulk oxidation model is preferably developed for each specific ATF composition. Samples of the fluid are subjected to oxidation in heated open aluminum beakers at temperatures spanning the temperature range that the fluid will experience in operation of the automatic transmission in which the fluid is to be used. The extent of fluid oxidation is measured in the content of each beaker preferably using the change in total acid number, delta TAN, via ASTM D664, initially and at suitable time intervals of the test. An increase in total acid number of, for example, 2.5 mg potassium hydroxide per gram of fluid (mg KOH/g) may be taken as indicating the end of the useful life of the fluid sample. The useful life of the ATF composition at each temperature is thus determined. Such data is plotted in linear form as a graph of the natural logarithm of the time (t) to end of useful fluid life (when ΔTAN=2.5 mg KOH/g) against the reciprocal of the beaker test temperature (T) in degrees Kelvin. The linear plot of Equation (1):
Ln ( t ) = A + B kT
yields intercept, A, and slope, B, as oxidation parameters of the specific fluid that are used in the thermal oxidation model. The constant, k, is a proprietary parameter incorporated to account for increase transmission severity over the beaker test method.
[0008] In an operating transmission, portions of the total fluid volume are circulated from the sump into the torque converter and into the torque converter clutch interface. At any moment of transmission operation, the fluid volume fraction at the clutch interface is often experiencing the highest level of current energy input while the balance of the fluid in the converter is also experiencing shear and is being heated. More of the fluid is in the transmission sump and the temperature in the sump fluid represents the recent energy input history of the transmission and the working ATF. When the vehicle is being driven, the fluid volumes circulating through the torque converter and torque converter clutch are heated and carry that heat into the contents of the sump. In a preferred embodiment of the invention, the oxidation model recognizes the different, usually higher, temperatures of the volume fractions of the fluid in the torque converter and the clutch for their deleterious effect on the remaining life of the ATF. Equation 1 is used in an expanded form to account for the different temperatures in the sump, torque converter and torque converter clutch.
[0009] In a preferred embodiment of the invention, and for microprocessor efficiency, Equation 1 is used to calculate a remaining useful life (RUL) for the ATF in this oxidation model at a reference temperature such as 80° C. The equation is then used to calculate penalty factors (PF) for fluid temperatures different from the reference temperature. During transmission operation, the microprocessor continually reads transmission sump temperatures, over successive processor sequences, and applies the penalty factor for the fraction of the fluid in the sump. Successively higher temperatures and penalty factors are used for the volume fractions of the fluid in the torque converter (TC) portion of the transmission and in the torque converter clutch (TCC) portion, respectively. The three reduction values (sump+TC+TCC) in fluid life are subtracted from initial value of fluid life and the sequence is repeated for the oxidation model during transmission operation events until there is no remaining useful ATF life.
[0010] In parallel with the ATF oxidation model, the PCM also executes a shift event friction model. An initial determination of lifetime shifts for the ATF at a reference temperature is made. The reference temperature may, for example, be a transmission sump temperature of 80° C. During PCM processing cycles for this model, a record of all shift events is made together with average sump temperature over the time interval of the cycle. Shift events include 1 st gear to 2 nd gear upshift/downshift, 2 nd gear to 3 rd gear upshift/downshift, etc., over the whole range of forward speed gears of the transmission. A shift energy input to the ATF is determined and associated with each shift correlated to the sump temperature. The microprocessor correlates stored shift energy values with each shift and reduces the value of the remaining number of shifts by the appropriate amount based on shift energy input to the ATF. This microprocessor executed process, like the oxidation model, is continued until one model yields no useful remaining ATF life.
[0011] It has been found that the combination of the above-described oxidation model and shift energy models provide a reliable, useful and microprocessor efficient method for determining the remaining useful life of an automatic transmission fluid. This parallel model approach does not understate the remaining life so that unnecessary ATF changes are made. And the model protects the transmission itself.
[0012] Other objects and advantages of the invention will be understood from a description of a preferred embodiment of the invention which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a process flow diagram of a preferred method for calculating remaining useful life of a transmission fluid by a fluid oxidation model.
[0014] FIG. 2 is a process flow diagram of a preferred method for calculating remaining useful life of a transmission fluid using a shift energy input model.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] Automatic transmission fluids exhibit a finite useful life due to oxidative degradation of the base oil and additive package. One common metric for assessing the general quality of current formulation type transmission oil is to measure the extent of bulk fluid oxidation as reflected in an increase in the total acid number (delta TAN) of the fluid via ASTM D664. Based upon historical data correlating to increased shudder tendency and loss of frictional performance, ATFs exhibiting an increase in TAN of 2.5 mg KOH/g are considered to be at the end of their useful life. The rate of bulk oxidation differs between oils and is a function of time at temperature in the presence of an oxidizing environment, the base oil chemistry, and the additive package formulation. In addition to loss of performance through bulk oxidation of the base oil, friction modifiers, present in minute concentrations, can also oxidize in the bulk fluid or locally at clutch interfaces without contributing appreciably to an increase in delta TAN.
[0016] Currently vehicle owner's manuals often specify three recommendations for transmission oil change intervals depending upon driver behavior, namely 50,000 miles, 100,000 miles, and fill for life (no change). However, oils can reach their end of useful life at different mileages. In addition, more aggressive usage of transmission systems in some applications has led to increased operating temperatures, which could reduce useful fluid life to mileages below the severe service recommendation of 50,000 miles. To account for this, transmission oil life algorithms, based upon bulk oxidation, have been implemented in vehicle transmission applications but they have not accurately tracked the condition of the ATF.
[0017] A new enhanced oil life algorithm has been developed to provide accurate feedback to vehicle operators of the oil change interval recommended for their driving behavior and transmission application. The model integrates two parallel approaches to determining end of useful fluid life, namely bulk oxidation due to time at temperature and specific degradation of frictional performance due to transmission shift events. Preferably, the oxidation model uses temperature information from more than one region of the operating transmission.
[0000] Oxidation Model
[0018] The bulk oxidation model was developed by subjecting ATFs to an Aluminum Beaker Oxidation test (ABOT) at 140° C., 150° C., 155° C., and 160° C. The extent of fluid oxidation was measured as the change in total acid number, delta TAN, via ASTM D664 at time intervals of 0, 150, 200, 250, and 300 hours. The average delta TAN of three repeat runs was plotted versus time for each fluid at each temperature. Linear functions were fit to the resulting plots. The slope of the fit lines were taken as the oxidation rate, delta TAN/hour, of the fluid. The time to the end of useful fluid life in hours at a given temperature was determined by dividing an end of useful fluid life, delta TAN of 2.5 mg KOH/g fluid, by the oxidation rate. The data was then linearized by plotting the natural log of the time to end of useful fluid life against the reciprocal of the ABOT test temperature in degrees Kelvin.
[0019] The slope and intercept of this line were the set as the fluids characteristic A and B oxidation parameters that subsequently were used in the thermal model as described in the following Equation 1:
Ln ( t ) = A + B kT ,
where t is the time to fluid failure in hours, T is the fluid temperature in degrees Kelvin, A and B are parameters that describe the oxidation behavior of a particular ATF and k is a proprietary parameter incorporated to account for increased transmission severity over the bench test environment.
[0020] This base equation could be written as follows for the temperatures that would be seen in the transmission sump, torque converter and torque converter clutch interface as shown in the following Equation 2:
ln ( t ) SUMP = A + ( B k * T sump )
ln ( t ) CONVERTER = A + ( B k * T converter )
ln ( t ) TCC INTERFACE = A + ( B k * T TCC )
[0021] The exponential of the natural log of time to fluid failure for each regime was then calculated resulting in a time to fluid failure in hours for each transmission subsystem as shown in Equation 3:
t failure,i =e ln(t)
where i is determined for sump, torque converter and TCC interface.
[0022] The time to fluid failure for the three subsystems was then summed by weight averaging each subsystem on a percent volume basis as shown in Equation 4:
t Total = ( SumpVol . TransTotalVol ) * t Sump + ( ConverterVol . TransTotalVol ) * t TC + ( TCCVol . TransTotalVol ) * t TCC
A particular transmission may, for example have an ATF capacity of eight liters. At a given moment in the operation of the transmission, approximately 1.5 L of fluid may be in the torque converter with an additional 0.5 liter in the torque converter clutch. The balance is presumed to be in the sump for purposes of these models. The volume percentages of fluid in the respective portions of the transmission are, of course, based on the total volume of eight liters.
[0023] The value of the parameter k was determined by correlating temperature histograms and fluid oxidation levels from a commercial transmission vehicle test. The value of k was varied until the calculated time to end of useful fluid life was equal to the actual time to end of useful fluid life.
[0024] The values for characteristic oxidation parameters A and B for three different commercial automatic transmission fluids and the severity factor, k, for a production transmission are listed in the following Tables 1 and 2. Fluid 1 uses an API Group II base oil and Fluid 2 uses an API Group I base oil.
TABLE 1 Characteristic Oxidation Parameters Severity Factor Fluid A B k 1 −18.643 10787 1.116 2 −32.099 16009 1.116
[0025]
TABLE 2
Reference Remaining
Reference
Useful Life
Fluid
Temperature
Hours
Seconds
1
800° C./353 K
6191.3
22,288,680
2
800° C./353 K
5047.5
18,171,000
[0026] Using these values, the remaining useful fluid life was calculated across the range of expected transmission operating temperatures. From these values a reference temperature of 353K (80° C.) was arbitrarily assigned. Look-up tables displaying penalty factors were generated by normalizing remaining useful fluid life against the reference remaining useful fluid life. Examples of these tables can be seen in the following table.
TABLE 3 Temperature Penalty Factors Celsius Kelvin Fluid 1 Fluid 2 −40 233 0 0 −20 253 0 0 0 273 0 0 20 293 0.004 0 40 313 0.03 0.006 60 333 0.19 0.09 80 353 1.00 1.00 100 373 4.34 8.83 120 393 16.2 62.5 140 413 53.3 366 160 433 157 1820 180 453 421 7850
[0027] The model works by subtracting units of time multiplied by the penalty factor from the reference remaining useful life for the applicable fluid. For example, for fluid 1, every second spent at the reference temperature of 353 K (80° C.), one second is subtracted from the remaining useful fluid life. However, for every second spent at 373 K (100° C.), 4.34 seconds is subtracted from the reference remaining useful fluid life. When the reference remaining useful fluid life reaches a value of zero, the algorithm signals the driver that it is time to change the oil. A detailed process flow diagram of a preferred on-vehicle computer executable process for using the oxidation model to estimate the remaining useful life of an ATF is shown in FIG. 1 . Definitions of the variables used in the FIG. 1 flow diagram follow:
[0000] Definition of Variables— FIG. 1
[0028] RUL t=0 =The remaining useful fluid life for unused ATF at the reference temperature.
[0029] ΔRUL=The total reduction in remaining useful life over time interval n.
[0030] RUL t+n =The calculated remaining useful life after a time interval n.
[0031] T sump,i =The sump temperature at time i, where i could be in seconds or hours, falls within the interval i=1 to n.
[0032] T avgsump =The average sump temperature over time interval, n.
[0033] ΔT TCC =The estimated temperature difference between the fluid in the torque converter and the fluid at the torque converter clutch interface.
[0034] PF=Penalty factor for a given fluid found in look-up table.
[0035] x 1temp =Dummy (i.e., temporary) variable assigned to hold the pre-weight averaged reduction in the remaining useful fluid life in the sump at the average temperature over time interval n.
[0036] x 2temp =Dummy (i.e., temporary) variable assigned to hold the pre-weight averaged reduction in the remaining useful fluid life in the torque converter at the average temperature over time interval n.
[0037] x 3temp =Dummy (i.e., temporary) variable assigned to hold the pre-weight averaged reduction in the remaining useful fluid life at the TCC interface at the average temperature over time interval n:
[0038] x 1 =Volumetrically weight averaged contribution of reduction in remaining useful life due to the sump.
[0039] x 2 =Volumetrically weight averaged contribution of reduction in remaining useful life due to the torque converter.
[0040] x 3 =Volumetrically weight averaged contribution of reduction in remaining useful life due to the TCC interface.
[0041] FIG. 1 , Block 1 indicates the calculation of the useful life of a specific unused ATF material at a reference temperature, T ref , in this example, 353 K (80° C.). The calculation is based on beaker oxidation data as described above and using Equations 1-4. Usage of the fluid results in reductions from its original or initial useful life. This determination of fluid life is stored in the memory of the PCM or like on-vehicle computer.
[0042] During operation of the vehicle, the PCM performs its processing cycles, each second or so, and receives a temperature input from a suitable sensor in the fluid sump of the transmission. Block 2 indicates the reading of the temperatures of the fluid in the sump, T sump,i over a brief suitable time period. In Block 3 the average temperature, T avgsump , of the fluid in the sump is calculated. In this example, the average sump temperature, T avgsump , is also used in the parallel friction model as described with respect to step 2 of FIG. 2 .
[0043] In Block 4 , the average sump temperature value, T avgsump , is rounded up to the nearest 5° C. for reading the predetermined penalty factor, PF, in a prepared look-up table as indicated in Block 5 . An excerpt of a look-up table, prepared as described above, is shown between Blocks 5 and 6 in FIG. 1 .
[0044] The computer then calculates a reduction in the useful life of the fluid due to its temperature experience over time interval, n, by multiplying n by the PF for the T avgsump for the interval (Block 6 ). The product of this calculation, x 1temp , represents an estimated reduction in remaining life of the ATF if the total volume of the fluid was at the temperature of the sump. The variable, x 1temp , is temporarily held as a dummy variable for correction in accordance with the volume percent of the fluid in the sump. This calculation is made in Block 7 of FIG. 1 . The volume percentage of the fluid in the sump is known for a particular transmission and may be considered a constant throughout transmission operation or corrected for different operation conditions and temperatures. The value obtained in Block 7 is temporarily stored in computer memory pending similar fluid life reduction calculations for the volume fractions of the fluid in the torque converter (TC) and the torque converter clutch (TCC) interface.
[0045] Commencing with Block 8 the transmission controller determines the reduction in useful fluid life attributable to the temperature experience of the volume fraction of ATF in the torque converter. If continuous temperature measurements of the fluid in the TC are available, these values can be used in the process. However, temperature sensors may not have been incorporated in the TC or the TCC, and it is desirable that temperature estimates be made for these portions of the ATF because they experience high temperatures that contribute significantly to the reduction of useful fluid life by oxidation.
[0046] In this example, the temperature of the fluid volume in the TC was estimated to average about 11° C. above the sump volume temperature. Thus, Block 8 repeats the steps of Blocks 2 - 4 except that 11 degrees Celsius are added to the measured sump volume temperature. An average TC temperature over the time interval is determined and rounded to obtain a penalty factor PF for the TC volume. Block 9 applies the PF to obtain a dummy value, as in Block 6 , value x 2temp for correction by the volume percentage of fluid in the TC. This is performed in Block 10 .
[0047] The steps performed in Blocks 11 and 12 estimate a reduction in fluid life for the volume fraction at the TCC interface using an estimated average temperature at the TCC interface relative to the TC temperature. In Block 11 , ΔT TCC is added to the estimated TC temperature, T sump +11° C., where ΔT TCC is typically a function of the power, in kW, transferred through the TCC. For example, in a 6.0 L engine/300 mm converter application, ΔT TCC =57.6*P TCC −15.6 for ΔT TCC >0. Often the temperature of the fluid at the TCC interface is slightly higher than the fluid volume in the TC.
[0048] In Block 13 the total reduction in remaining useful fluid life over the time interval Δt is obtained by adding the reductions for the fluid volume percentages in the sump, TC and TCC interface. Thus, ΔRUL=x 1 +x 2 +x 3 . In Block 14 the computer calculates the new remaining useful life of the fluid by subtracting the currently determined reduction in fluid life due to oxidation from the previous cycle useful life value, indicated by the equation RUL t+n =RUL t −ΔRUL. The value for RUL t+n becomes RUL t in the next iteration from which a new ΔRUL will be subtracted. Thus, RUL continually decreases as the algorithm runs.
[0049] As indicated in oxidative model process Block 15 , the computer cycling continues during transmission use and the steps of Blocks 2 - 14 are repeated until RUL=0. When RUL=0, a signal is commanded to notify the vehicle operator to change the ATF. However, in accordance with this invention, a parallel computer process is being executed with a friction model accounting for shift energy input and the “change ATF” signal is given when one of these parallel processes first determines that RUL=0.
[0000] Friction Degradation Model
[0050] A friction degradation model is developed by subjecting an ATF to an SAE #2 Test Apparatus plate friction test using a modified DEXRON®-III test procedure. A 3 2 design of experiment, shown in the following table, was set up with shift energy and bulk fluid temperature as the two variables.
Design of Experiment for Friction Degradation Model
[0051]
Experiment
Shift Energy
Temperature
1
−
−
2
−
0
3
−
+
4
0
−
5
0
0
6
0
+
7
+
−
8
+
0
9
+
+
[0052] The fluid is run until frictional performance degrades to unacceptable levels as determined by a rapid decrease in midpoint torque below the DEXRON®-III specification limit and/or a slow decrease in midpoint torque to levels below a critical lower limit. The number of shift events which occurred prior to end of useful fluid life are calculated based upon the number of test cycles completed and the data will be fit using statistical analysis software to a general equation of the form shown below as Equation 5:
y=a 0 +a 1 x 1 +a 2 x 2 +a 3 x 1 x 2 +a 4 x 1 2 +a 5 x 2 2 +a 6 x 1 2 x 2 +a 7 x 1 x 2 2 +a 8 x 1 3 + . . .
[0053] The specific equation for a specific fluid follows as Equation 6:
TNS= 878000−2455 *T− 66330 *E+ 1410 *E 2 +82 *T*E
where
TNS=Total number of shifts until end of useful remaining fluid life, T=The temperature of fluid in the sump, and E=Estimated shift energy from a look-up table.
[0057] The model is equated to actual transmission performance by correlating to data gathered on a DEXRON®-III commercial transmission cycling test. If necessary, parameters are added to adjust to severity of the model to agree with the cycling test data. The model is then implemented into an algorithm similar to the bulk oxidation model to calculate remaining fluid life through a parallel path. The model works by counting the number and type of shift events occurring over a given time interval. Using the preset shift energies for each type of shift event and the average sump temperature over that interval (already calculated by the bulk oxidation model), the remaining number of shifts a fluid can experience before end of useful life at those conditions is determined.
[0058] Shift energy is generated when a transmission is shifted between gears. At the start of a shift, the clutch or band being applied is slipping at a known speed. At the end of a shift this slip speed is reduced to zero. Shift energy is the amount of energy generated in the process of eliminating this slip. To calculate the shift energy, a vehicle is instrumented and the following parameters are recorded: transmission sump temperature, transmission input and output speed, commanded gear, clutch pressure for the oncoming clutch for the shift, and vehicle acceleration. This data is then used with transmission hardware constants to calculate the clutch slip versus time and clutch-apply force versus time for the shift. Knowing the clutch-slip and clutch-apply force, the power generated in the clutch is calculated. This power is the shift energy used in the FIG. 2 friction process.
[0059] The preset shift energy data for each type of shift is normalized against the remaining number of shifts at a reference temperature and multiplied by the number of specific shift events (i.e, number of 1-2 up shifts), which have occurred over that time interval. This is done for all types of shift events, such as 1-2, 2-3, and 3-4 up shifts, and the reduction in the remaining number of shifts over that time interval due to all shift events is summed and subtracted from the remaining number of shifts to end of useful life. When the counter equals zero, the driver is notified to change the oil. In this algorithm, more than one look-up table would be required. In order to save PCM space, calculations were done as needed. Also, although the bulk oxidation model runs in parallel with the friction degradation model, the average sump temperature calculated over a given time interval in the bulk oxidation model are shared with the friction degradation model.
[0060] A process flow diagram of a preferred method of computer execution of determining remaining shift life is presented in FIG. 2 . In this example, an automatic transmission with six forward speeds is modeled. Such a transmission normally experiences more frequent gear shifts than transmissions with fewer forward gears. The definition of variables referred to in FIG. 2 follow in the next paragraphs.
[0000] Definition of Variables— FIG. 2 .
[0061] TNS ref =Total number of shifts for an unused ATF at the reference temperature and shift energy.
[0062] T ref =Predetermined reference temperature in Kelvin.
[0063] E ref =Predetermined reference shift energy in kJ.
[0064] RNS=Remaining number of shifts before end of useful fluid life.
[0065] ΔRNS t→t+n =Reduction in the remaining number of shifts over time interval n.
[0066] TNS(T avgsum , E i )=Abbreviation for total number of shifts as a function of average sump temperature and shift energy.
[0067] T avgsump =Average sump temperature in Kelvin over time interval, n.
[0068] E i =Shift energy for a given shift i, kJ.
[0069] P, Q, R, S, T=The number of 1-2, 2-3, 3-4, 4-5, and 5-6 shifts respectively, including corresponding downshifts, over time interval n.
[0070] An initial number of gear shifts for an unused fluid is estimated or determined at a reference temperature, for example, 353 K (80° C.). This may be done using a process like that summarized above resulting in Equation 5. Equation 6 is a specific example of an equation that may be used for this purpose. In FIG. 2 , this step is indicated in Block 1 and the resulting value of TNS ref is stored in the database of the computer.
[0071] In the step 2 of the FIG. 2 friction model process, Blocks 2 a and 2 b , the current average sump fluid temperature over a selected time interval, n, is noted (Block 2 a ) from FIG. 1 (Block 3 ). Concurrently, all forward shift events, upshift or downshift, during the same time interval, n, are read, Block 2 b . Shifts in and out of neutral are found to have negligible effect on the useful life of the ATF and are not recorded in this friction model. Downshifts are considered as imparting less shift energy into the transmission converter clutch than upshifts. Downshifts may be considered to impart half the energy input of a corresponding upshift. Accordingly, in Block 2 b , shift events during a time interval are recorded respectively as P 1 , upshift first to second gear; P 2 , downshift second to first gear; Q 1 , upshift second to third gear; Q 2 , downshift third to second gear; R 1 , upshift third to fourth gear; R 2 , downshift fourth to third gear; S 1 , upshift fourth to fifth gear; S 2 downshift fifth to fourth gear; T 1 , upshift fifth to sixth gear; and T 2 , downshift sixth to fifth gear.
[0072] Knowing the current average sump temperature and the respective shifts, a calculation of the reduction in remaining number of shifts (ΔRNS) is made to account for the reduction in fluid life due to shift energy input, i.e., friction degradation. This calculation is suitably made using a model as indicated in Block 3 of FIG. 2 . The model uses a predetermined shift energy, E, in kJ at an average sump temperature, T avgsump . The shift energies for the respective upshifts vary by vehicle application, are dependent on throttle position at the moment of the upshift and can be stored as a look-up table. As stated, the shift energies for the respective downshifts are half the values of the corresponding upshifts at the throttle position.
[0073] The determination of friction degradation is based on the shift energy and temperature of the fluid in the sump as described above. Thus, a value of the current ΔRNS over current time interval n is calculated. The process moves to Block 4 of FIG. 2 , which illustrates the calculation of the remaining number of shifts that the ATF can tolerate at time t+n. As shown in Block 4 , the calculation is RNS t+n =RNS t −ΔRNS t→t+n .
[0074] The steps of Blocks 2 - 4 are repeated as indicated in Block 5 until RNS=0, provided that the parallel oxidation process does not produce RUL=0 first. If the calculation of Block 5 reaches zero, notice is given to the vehicle operator (Block 6 ) to change the transmission fluid.
[0075] Thus, as described, an oxidation model and a friction model are used in parallel for determining the remaining useful life of an ATF in a vehicle automatic transmission. The models are adaptable and applicable to automatic transmissions with any number of forward speeds. The process is readily executed on a transmission control module with a microprocessor and is effective in notifying the operator of the vehicle of the end of the useful life of the transmission fluid. One of the advantages of this method is that, as current determinations of remaining life for the two models are made, the current temperature data and intermediate calculation data do not need to be retained in the processor. Reference data such as penalty factors for an oxidation model and shift energy data for the friction model are retained. But with respect to ongoing calculations, only the current remaining useful life data for the two models is retained. This reduces memory requirements and increases microprocessor efficiency.
[0076] The invention has been described in terms of certain examples, but the scope of the invention is not limited to these illustrations. | The remaining useful life of a transmission fluid in a vehicle is continually estimated by a transmission control computer module during vehicle operation using both an oxidation model and a shift energy model. The oxidation model uses experimentally determined remaining useful fluid life values obtained at temperatures experienced by the fluid in transmission usage and subtracts incremental values from said life based on the temperature-time experience of volume fractions of the fluid in the sump and torque converter. The shift energy model starts with an estimated maximum number of shifts and continually obtains a current remaining useful life by deducting for actual shifts and estimated shift energy inputs based on fluid temperature. Notice of end of fluid useful life is given when one of the models first determines no remaining useful fluid life. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims the priority benefit of U.S. provisional patent application Ser. No. 61/253,005, filed Oct. 19, 2009, the disclosure of which is hereby incorporated by reference.
This application is related to U.S. Pat. No. 6,270,431, issued Aug. 7, 2001, and U.S. Pat. No. 6,012,995, issued Jan. 11, 2000, the disclosures of which are both hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the game of table tennis and associated equipment. The present invention more particularly relates to a table tennis table with an automated ball serving device and an automatic scoring device.
2. Description of the Related Art
A game of recreational table tennis has at least three intrinsic factors that cause unwanted game delays. These factors include the following:
1. Retrieving the ball between rallies
2. Losing track of the serve-turn
3. Losing track of the score
The technology disclosed herein allows users to play table tennis without taking time to retrieve balls. The technology also relieves users of the need to track the score and the proper server.
SUMMARY OF THE INVENTION
The exemplary embodiments described herein allow users to enjoy a modified game of table tennis in which one or more automatic serving guns provide the serving function normally performed by the serving player. The ball may be put in play as fast as a player can trigger the automatic serving function, for example, by tapping a remote control device on his hip. An automated ball serving system may automatically track the serve-turn and cause a serving gun to serve the ball to the correct player. Additionally, the score may be accurately announced by the automated scoring device after each ball is put into play by the serving gun.
The serving guns may each include a propulsion device that directs the ball to an appropriate serve receiving area. A queuing device (e.g., a ball basket) associated with each serving gun holds a plurality of table tennis balls to be served. The automated ball serving system may include a serve-tracking function that instructs the serving device to direct each serve to an appropriate serve receiving area on a table tennis table.
The ball serving system may also include a method to vary the landing spot of the served balls. The system may vary the landing spot by altering the velocity at which the serving guns eject the balls. The system may be programmed to randomly vary the landing spot.
In some embodiments, sensors may provide data for determining the landing point of a served ball. The landing point data may be used to calibrate the serving guns.
In other embodiments, the serving gun may include a sensing device to measure the RPM of the rotation of the wheel. The sensing device may be a phototransistor that includes a light emitting diode (LED), whose light may be reflected off a mirror affixed to the wheel and detected by the phototransistor.
In still other embodiments, the direction in which the balls are served by the serving gun is variable. A variation may be implemented by rotatably mounting the serving guns on the table and controlling rotation of the guns with stepper motors. The rotation of the serving gun, and hence location of the serve, may be controlled by the ball serving system. The location of the serve may be randomly chosen by the system.
A target device may be positioned on the table. The target device may be coupled to a collection device with a mechanism that allows a user to visually determine a number of balls in the collection device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of an exemplary table showing four ball bucket motors, four serving guns, and associated ball connection tubes, according to various embodiments.
FIG. 2 is a first side view of the table of FIG. 1 .
FIG. 3 is a second side view of the table of FIG. 1 .
FIG. 4 is a detail view of the ball serving device control and display panel of the table of FIG. 1 .
FIG. 5 is a detail view of a first serving gun and the ball control panel of the table of FIG. 1 .
FIG. 6 is a detail view of a second serving gun, the score correction panel and the ball control panel of the table of FIG. 1 .
FIG. 7 is a detail view of a third serving gun and the ball control panel of the table of FIG. 1 .
FIG. 8 is a detail view of a fourth serving gun, the ball control panel, and the score correction panel of the table of FIG. 1 .
FIG. 9 is a diagram of an exemplary circuit that controls four bucket motors and four serving guns for the ball serving device.
FIG. 10 illustrates an exemplary configuration for a 3-button wireless remote used by player one and a diagram of an exemplary circuit for the player one 3-button wireless remote.
FIG. 11 illustrates an exemplary configuration for the 3-button wireless remote used by player two and a diagram of an exemplary circuit used for the player two 3-button wireless remote.
FIG. 12 illustrates an exemplary configuration for the score correction panel (wireless or wired) and a diagram of an exemplary circuit used for the wireless remote score correction panel
FIG. 13 is a top view of an exemplary embodiment of a table using two serving guns fed by two bucket motors.
FIG. 14 is a side view of the table of FIG. 13 using two serving guns fed by two bucket motors.
FIG. 15 is a side view of an exemplary ball serving device configured for use with an aftermarket table.
FIG. 16 is a diagram of an exemplary circuit for controlling two serving guns and two bucket motors.
FIG. 17 is a top view of an exemplary table that includes four serving guns fed by one bucket motor and a ball routing switch mechanism.
FIG. 18 is a first side view of the table of FIG. 17 .
FIG. 19 is a second side view of the table of FIG. 17 .
FIG. 20 is a diagram of an exemplary circuit that controls four serving guns, one bucket motor, and one ball routing switch mechanism.
FIG. 21 illustrates an exemplary configuration for a single-button wireless remote used by player one and a diagram of an exemplary circuit used for the player one single-button wireless remote.
FIG. 22 illustrates an exemplary configuration for a single-button wireless remote used by player two and a diagram of an exemplary circuit used for the player two single-button wireless remote.
FIG. 23 illustrates a top view of a table with two “Shooter Pong” buckets.
FIG. 24 is an end view of the table illustrated in FIG. 23 .
FIG. 25 shows a detail view of the “Shooter Pong” bucket and numbered penalty marker rows (one through five) and arrow pointer
FIG. 26 shows an example of a printed penalty label.
FIG. 27 shows an alternative example of a printed penalty label.
FIG. 28 shows another alternative example of a printed penalty label.
FIG. 29 is a diagram of an exemplary circuit to control a two gun/two bucket configuration with variable serve distance.
FIG. 30 is a diagram of an exemplary circuit to control a four gun/four bucket configuration with variable serve distance.
FIG. 31 is a diagram of an exemplary circuit to control a four gun/one bucket/ball router configuration with variable serve distance.
FIG. 32 shows a top view of an exemplary configuration for the self-calibrating ball serving system with pivot capability.
FIG. 33 is a detail view of a first serving gun with pivot capability.
FIG. 34 is a detail view of a second serving gun with pivot capability.
FIG. 35 is a detail view of a third serving gun with pivot capability.
FIG. 36 is a detail view of a fourth serving gun with pivot capability.
FIG. 37 is a diagram of an exemplary circuit for a self-calibrating ball serving system with a two serving guns/two bucket motors configuration.
FIG. 38 is a diagram of an exemplary circuit for a self-calibrating ball serving system with a four serving guns/four bucket motors configuration.
FIG. 39 is a diagram of an exemplary circuit for a self-calibrating ball serving system with a four serving guns/one bucket motor/one ball routing switch mechanism configuration.
FIG. 40 is a diagram of an exemplary circuit for a ball serving system with an RPM motor controller in a two serving guns/two bucket motors configuration.
FIG. 41 is a diagram of an exemplary circuit for a ball serving system with an RPM motor controller in a four serving guns/four bucket motors configuration.
FIG. 42 is a diagram of an exemplary circuit for a ball serving system with an RPM motor controller in a four serving guns/one bucket motor/one ball routing switch mechanism configuration.
FIG. 43 shows an exemplary configuration for a table tennis paddle with a wireless remote inside the paddle handle and the associated diagram of an exemplary circuit using encoder data channel D3 for player one inputs.
FIG. 44 shows an exemplary configuration for a table tennis paddle with a wireless remote inside the paddle handle and the associated diagram of an exemplary circuit using encoder data channel D4 for player two input.
FIG. 45 is a diagram of an exemplary circuit for manual serving gun wheel speed motor control.
DETAILED DESCRIPTION OF THE INVENTION
An exemplary embodiment is a ball serving system that may include an automated ball serving device and an automated scoring device for a table tennis game. The automated scoring device may include both audio and visual displays and may incorporate aspects of commonly-owned U.S. Pat. No. 6,012,995, titled “Scorekeeping Racket Device with Audio and Visual Display,” and U.S. Pat. No. 6,270,431, titled “Control Grid for Table Tennis Scorekeeping Device with Audio and Visual Display,” both of which are hereby incorporated by reference. Using both the automated ball serving device and the automated scoring device may eliminate common game delay conditions: retrieving the ball between rallies, losing track of the serve-turn, and losing track of the score.
FIG. 1 shows a top view of a table tennis table 100 utilizing the ball serving system. The table 100 may be equipped with automated ball serving devices (e.g., serving guns 105 ), and may utilize automated score keeping functions. In the configuration depicted in FIG. 1 , four serving guns 105 , 110 , 115 , 120 are used to serve from the four serving areas of the table. Serving gun 105 may be considered the right side serving gun of player one. Serving gun 110 may be considered the left side serving gun of player two. Serving gun 115 may be considered the right side serving gun of player two, and serving gun 120 may be considered the left side serving gun of player one.
Each serving gun may be supplied by a ball bucket 125 . The ball bucket 125 may hold a plurality of balls to supply the associated serving gun. In various embodiments of the device, the balls may be fed to the serving guns through elbow tubes 205 that feed into straight feed tubes 210 . The elbow tubes 205 and the feed tubes 210 are illustrated with additional detail in FIGS. 2 and 3 .
The motive force to move the balls through the tubes 205 , 210 and to propel the balls from the serving guns may be provided by a motor 130 . FIGS. 1-3 illustrate a configuration of the table 100 in which four motors 130 serve four serving guns. A diagram 900 for an exemplary circuit for the four motor/four gun configuration is illustrated in FIG. 9 .
FIGS. 1-3 show four motors 130 , one motor 130 associated with each serving of the four serving guns. It will be recognized by those skilled in the art that the table 100 can be configured with various other combinations of motors 130 and serving guns. Various alternative configurations of the serving guns and the motors 130 are possible. FIGS. 13 and 14 illustrate a configuration in which two serving guns are fed by two motors 130 . A diagram 1600 of an exemplary circuit for the two motor/two gun configuration is illustrated in FIG. 16 . FIGS. 17-19 illustrate a configuration in which four serving guns are fed by one motor 130 . A ball routing switch 1705 may be included in this configuration to properly route the balls to the correct serving guns. A diagram 2000 of an exemplary circuit for the one motor/four gun configuration is illustrated in FIG. 20 .
FIG. 15 shows a configuration in which the serving guns are not mounted on the table. It is envisioned that this embodiment may be used to add the serving guns to a standard table that was sold without the serving guns. The serving guns may be positioned on the floor under the table, and may be placed so that the serving guns serve the balls to proper serve receiving areas.
The serving guns, however configured, may be positioned to serve the ball to a specific section (i.e, a serve receive area) of the table 100 . The serving guns will typically serve the ball to the end opposite from the serving gun where there is a serve receive area. Referring again to FIG. 1 , the serving gun 105 to the right of player one may serve to the same table side (i.e., left side of player two) at a first end 140 of the table 100 . The serving gun 120 to the left of player one may serve to the right side of the first end 140 of the table 100 . Similarly, serving gun 110 to the left of player two may serve to the right side of a second end 135 of the table 100 , while the serving gun 115 to the right of player two may serve to the left side of the second end 135 of the table 100 .
FIGS. 5-8 illustrate an exemplary embodiments of a ball serving system including a method of ball direction and propulsion from the serving guns. While it will be recognized by those skilled in the art that many types of propulsion and direction may be utilized for each serving gun, in various embodiments of the technology, the propulsion mechanism may be a rotating wheel 505 .
Each serving gun may be provided with a ball control panel 510 that controls the serving gun. The ball control panel 510 may include a test serve button 515 that allows the user to determine if the serving gun is properly set up. A wheel speed adjustment control 520 may also be provided to adjust the speed at which the balls are ejected from the serving gun. The ball control panel 510 and the wheel speed adjustment control 520 may be mounted on an edge of the table 100 as depicted in FIGS. 5-8 . FIG. 45 is a diagram of an exemplary circuit 4500 that provides the ball serving system with manual control over the speed of the wheel 505 .
A ball position sensor 525 may be installed in the serving gun 105 to determine the position of a given ball in the serving queue.
In some embodiments, the distance that the serving guns propel the ball on a serve may be varied. The ball serving system may be programmed to randomly select a distance each time a serve is triggered. Diagrams of exemplary circuits 2900 , 3000 , and 3100 that provide the serving guns with variable serving distance are illustrated in FIGS. 29-31 . For a long serve (i.e., maximum distance), maximum power may be provided to the serving gun by enabling a power boost circuit that provides maximum power output through a second resistor B in parallel with the power from first resistor A. For a short ball-serve, the power boost circuit may be turned off and the serving gun may be powered using the single path power output through first resistor A.
When the ball serving system is used with the variable serving distance option, the ball serving distance may be manually calibrated during a first-time table set-up and power-on. To calibrate the short ball-serve, the serving gun may be triggered to fire balls while the user adjusts the wheel speed adjustment control 520 to provide enough power so that the ball consistently clears the net. It will typically not be necessary for manual adjustment of the long ball-serve function, as maximum power is simply applied to the serving gun.
In other embodiments of the ball serving system, the system may be self-calibrating. The self-calibrating system may use sensors to determine a landing position of the ball. Accelerometers may be used as the sensing devices. An exemplary configuration illustrated in FIG. 32 utilizes six accelerometers 3225 - 3250 and four serving guns 105 - 120 . Diagrams of exemplary circuits 3700 , 3800 , and 3900 that operate the self-calibrating method of distance control for various configurations of the system are illustrated in FIGS. 37-39 .
Calibration of the ball serving system may be initiated by triggering one of the serving guns (e.g., serving gun 115 ) to serve a ball. When the ball contacts the table 100 , two voltages may be read from accelerometers 3230 and 3235 . The accelerometer voltage data may be used to determine where the ball hit on the table. For illustrative purposes, the voltage from accelerometer 3230 is designated as V 3230 , and the voltage from accelerometer 3235 is designated as V 3235 . If V 3230 −V 3235 =0, then the ball hit at mid-point B. If V 3235 −V 3230 >0, then the ball landed short of mid-point B. If V 3235 −V 3230 <0, then the ball landed past mid-point B. The difference between the accelerometer voltages may be used to calculate the desired serving gun wheel speed RPM value based on the calibration serve.
An alternative configuration utilized in various embodiments to allow variable ball serve distance is illustrated in FIGS. 33-36 . Diagrams of exemplary circuits 4000 , 4100 , and 4200 that operate this alternative method of distance control for various configurations of the system are illustrated in FIGS. 40-42 . In this configuration, an LED and sensor unit (e.g., phototransistor 3305 ) may be used to monitor the RPM of the wheel 505 . The RPM is determined by the phototransistor 3305 detecting a reflection from a mirror 3310 affixed to the wheel 505 of the serving gun. The RPM of the wheel 505 may be varied according to the data obtained from the phototransistor 3305 . If the RPM drops below a preset low limit, power to the wheel 505 may be increased, thereby increasing the RPM. Conversely, if the RPM increases above a preset high limit, power to the wheel 505 is decreased. Using the digital RPM data from the phototransistor 3305 allows the ball serving system to compensate for aging components so that the system may retain accurate ball serve velocity throughout its lifetime. Those skilled in the art will recognize that many different systems of monitoring and varying the RPM of the wheel 505 may be utilized.
Another variation used in various embodiments of the ball serving system includes a configuration in which the serving guns 105 may be rotated to change the direction of the serve. In this configuration, illustrated in FIGS. 33-36 , the serving guns 105 are rotatably mounted on the table 100 . A pivot stepper motor 3315 may be used to rotate the serving gun, thereby altering the direction of the ball served. Operation of the ball serving system with rotating serving gun capability may be controlled by the circuits 3700 , 3800 , and 3900 illustrated in FIGS. 37-39 . In order to ensure proper serving distance, the ball serving system adjusts the RPM of the wheel 505 according to the direction in which the serving gun is directed. The calibration serve RPM value may serve as the baseline value used to calculate the required wheel RPM for different serve receive locations on the table. Each serve gun position (based on encoder data from the stepper motor) may have an associated predefined constant that is added or subtracted from the calibration serve RPM baseline value.
Referring now to FIG. 4 , the serving guns can typically be used in conjunction with an automated scoring device 405 . The automated scoring device 405 may include a speaker 410 so that the automated scoring device 405 may have the capability to audibly announce the score and game situation (e.g., server, change serve). In order to synchronize the operation of the serving guns and the automated scoring device 405 , a system link 415 may be provided. The system link 415 couples the automated scoring device 405 to a user interface and display panel 420 that controls the operation of the serving guns, thereby establishing the control system for the automatic ball serving system. (Options available through the user interface and display panel 420 are described in further detail below.) If the user has chosen to include the digital display option of the automated scoring device 405 , a digital display jack 425 is provided to connect the automated scoring device 405 to a digital display for a visual display of the score.
As is illustrated in FIGS. 6 , 8 , and 12 (wiring diagram), a score correction control panel 605 may be provided to manually control the automated scoring device 405 . At least one score correction control panel 605 may be mounted on each end 135 , 140 of the table 100 . The score correction control panel 605 may include an undo button 610 that erases the last point entered. The score correction control panel 605 may also include a reset score button 620 . The reset score button 620 may reset the score, for example, to 0-0 at the start of a new game.
At times, it may be desirable to fold the table 100 for storage. When this is the case, a connector joint 1710 may be included in each of the straight feed tubes 210 . The connector joint 1710 may also be positioned between the straight feed tubes 210 and the elbow tubes 205 . The connector joint 1710 may be employed at any position which facilitates folding of the ball feed tubes 205 , 210 in order to fold and store the table 100 .
The operation of the automated scoring device 405 is described in detail in the related U.S. Pat. No. 6,270,431, issued Aug. 7, 2001. In various embodiments, the automated scoring device 405 and the serving guns are coupled to establish the ball serving control system. The ball serving system outputs data to the automated scoring device 405 to track the score so that the automated scoring device 405 is able to audibly notify the players of the score.
The automated scoring device 405 may require an input of which player wins each point to accurately track game progress. One method of providing such input is illustrated in FIGS. 10 and 11 , each of which includes a three button wireless device 1005 that can communicate with the ball serving system, display panel's 420 user interface/display, and scoring device 405 . The three button device 1005 may include an undo button 1010 that, similar to the table mounted score correction control panel 605 , allows a user to erase the last result input to the automated scoring device 405 . The three button wireless device 1005 may also include a repeat button 1015 which allows the user to have the automated scoring device 405 repeat the current score.
One function of the three button wireless device 1005 is incrementing the score as points are completed. Whenever a user wins a point, the user may press a serve/score button 1020 . Depressing the serve/score button 1020 causes the ball serving system to increment the score of the proper player and to track the number of points played. In various configurations, pressing the serve/score button 1020 may cause one or more of the serving guns to eject a ball.
Another version of the wireless device is the one button wireless device 2105 illustrated in FIGS. 21 and 22 . The one button wireless device 2105 has only a serve/score button 2110 . The function of the serve/score button 2110 is the same as that of the serve/score button 1020 on the three button wireless device 1005 .
Another wireless device that may be used to operate the ball serving system is illustrated in FIGS. 43 and 44 . A table tennis paddle 4305 may include a serve/score button 4310 . In various embodiments, the serve/score button 4310 is located at the base of the handle of the paddle 4305 . A user may activate the serve/score button 4310 by tapping the paddle 4305 against his hip or thigh, on the table 100 , or on any other available resistive surface.
The table tennis game with an automated ball serving gun and automated scoring device 405 may be programmed to provide at least eight selectable play options. The options are shown in the detail view of the user interface and display panel 420 illustrated in FIG. 4 .
A first selectable option may be a “Rally Pong” mode. With this option, the remote devices 1005 , 2105 , and 4305 and serving guns are used to start each point. A ball is served by the serving gun directly to a receiving player after a serve/score button is pressed. Unlike traditional table tennis, no time is wasted waiting for a server to retrieve and serve the ball. Typically, a ball is served in less than two seconds after a player actuates his serve/score button.
Players may score their own points using wireless remote control devices 1005 , 2105 , and 4305 . Typically, the players try to score their points as quickly as possible in an attempt to catch their opponent off balance or out of position. The “Rally Pong” game is so fast that mentally keeping track of the serve-turn and score would be extremely difficult. The serve-turn problem may be solved by the ball serving system. The score keeping problem may be solved by the automated scoring device 405 , which announces the score after a ball is put into play.
In the “Rally Pong” mode, a new game may be initiated by selecting power on or by pressing a reset score button 620 . Either of these actions can reset the ball serving guns and output the “Reset Score” message from the automated scoring device 405 . The players may assume their playing positions and prepare for the first serve of the next game. At this point, the serving guns and the automated scoring device 405 may be waiting for a first remote serve/score button input from either player. After the first serve/score button input is received, the message “Begin New Game” is announced through the automated scoring device 405 and the display panel's 420 user interface randomly selects the first serving player. The ball is served to the receiving player immediately after the “Begin New Game” message is announced.
The automated scoring device 405 may also announce a midpoint of a game. According to the rules of the game of table tennis, at the midpoint of a game that is a rubber game, the players switch ends. If the game being played is not a rubber game, then the midpoint signal may be ignored by the players.
The table may be equipped with two serving guns, with one serving gun mounted on each side of the table ( FIGS. 13 , 14 , and 15 ). According to various embodiments of the invention, the table may be equipped with four serving guns. In the four gun configuration, a pair of serving guns is directed towards each end of the table ( FIGS. 1-3 , 17 , 18 , and 19 ). With the four serving gun option, the display panel's 420 user interface may randomly select left or right serve receiving area, with the display panel's 420 user interface then activating the appropriate serving gun for the chosen receiving area.
Still referring to FIG. 4 , the second selectable game option is the “Catch and Serve Mode.” This mode accommodates players who prefer to serve the ball themselves. In this mode, the serving gun can softly eject a ball to the serving player to catch-and-serve. This game may be slower than the “Rally Pong” option, but may still be faster than traditional table tennis because the server is not wasting time retrieving the ball between rallies. The score is announced by the automated scoring device 405 immediately after the ball is ejected to the serving player.
The third and fourth selectable options are single player practice modes, namely, “Practice Mode Left” and “Practice Mode Right,” respectively. A player may select an automatic continuous ball serving mode from either end of the table 100 . After the mode is selected, the player has a preset time (such as five seconds) to prepare before the serving guns begin serving. The serving guns continue to serve balls at a preset rate until the serving guns run out of balls or until the device is switched off by the player. If four serving guns are installed, the serve may alternate between left and right side serving guns.
The fifth selectable option shown in FIG. 4 is the “No Score Practice Mode” where two players (for singles) or four players (for doubles) may practice without the interruption caused by the score announcing system. In this mode, the score announcements and attendant ball serve delays may be suppressed. Specifically, there may be no ball serve delay for the “Begin New Game”, “Skunk”, “Reset Score”, “Deuce” and “Game Over” messages. However, there may be a ball serve delay for the change of serve direction where the ball is served after the “Rotate Serve” message. This mode of play may be even faster than “Rally Pong” mode. Players can practice against each other at a very fast rate continuously until the ball serving gun runs out of balls.
A sixth selectable option shown in FIG. 4 is the “Automatic Serve Off” mode where the serving players retrieve and serve the ball themselves. The automated scoring device feature may be used in this mode. This mode may be used, for example, if the serving machine is broken or not enough balls are available to utilize the serving machine function.
FIG. 4 shows a seventh selectable option, the “Shooter Pong” mode. In “Shooter Pong” mode, two serving guns from one end of the table 100 may alternate serving balls to the left and right side receiving areas at the second end 135 of the table 100 . As depicted in FIGS. 23 and 24 , two buckets 2305 may be positioned as targets at the table end opposite the players.
The object of the “Shooter Pong” game is for player 1 (or team 1 ) and player 2 (or team 2 ) to hit their balls into their designated target bucket 2305 . Balls that are hit into the target buckets 2305 may be funneled into a clear tube 2310 that may be rotatably attached to the bottom of the target bucket 2305 . The clear tube 2310 can display the number of balls made (i.e., hit into target bucket 2305 ) by the respective players or teams. A sensor in the clear tube 2310 may be used to detect when clear tube 2310 has been filled. The player/team that fills their clear tube 2310 first wins the game. The losing player/team may be subject to a penalty that may be found on a label affixed to the clear tube 2310 .
As depicted in FIGS. 25 thru 28 , the penalty labels may be listed between two border lines that are spaced apart to match the width of each ball. The last ball made, which appears under the tube label, is the losing team/player's penalty. To provide a greater variety of penalties and a more random selection of penalties, the ball tube may provide ten rows of penalties that are repeated in random order. To obtain a penalty, a player may simply rotate the ball tube (illustrated in FIG. 25 ) until the penalty number (which may be randomly chosen by the ball serving system) aligns with an arrow marker at the point where the ball tube connects to the ball bucket. In addition to the example ball tube labels shown in FIGS. 26 thru 28 , the players can design and/or order additional ball tube labels.
In “Shooter Pong” mode, after the serving guns serve a given number of balls (e.g., twenty balls), the ball serving system may cause the serving guns to momentarily stop serving and signal the automated scoring device 405 to output a series of beep tones and/or announce “Next Player”. If teams are playing, then player two may play the next twenty balls for his team. The “Shooter Pong” mode lends itself to certain social events as there is no limit to the number of players on a team, and it is not necessary for the teams to have the same number of players. The players on each team may rotate after each set of twenty balls served.
In “Shooter Pong” mode, after the clear tube 2310 is filled, the target bucket 2305 may output a signal to the ball serving system to turn off the serving guns and signal the automated scoring device 405 to announce or display the results of the game. For example, the announcement may be “Game over, your penalty number is three,” where the number three is a number randomly selected by the ball serving system.
As depicted in FIGS. 26 thru 28 , penalty labels may be listed between two border lines that are spaced apart to match the width of a ball. The label may then be affixed to the clear tube 2310 . The position of the last ball of the losing team/player under the label in the clear tube 2310 may indicate the penalty of the losing team/player. The nature of the penalty may vary according to the purpose of the game. FIG. 26 illustrates a table of penalties related to household chores for family use, while FIG. 27 illustrates a table of penalties of monetary donations for charitable events. Finally, FIG. 28 illustrates a list of penalties that may be used for parties.
To provide a greater variety and a more random selection of penalties, the label for the ball tube 2310 may be provided with any number of rows of penalties that are repeated in random order. To determine the penalty of a losing player/team, the clear tube 2310 is rotated (see FIG. 25 ) until the announced random penalty number three lines up with an indicator on the target bucket 2305 . The position of the last ball in the tube 2310 then determines the suggested penalty.
The eighth selectable option shown in FIG. 4 is the “Shooter Pong (SP)” or single player mode. In this mode, the ball serving system activates only one serving gun so that a single player can practice hitting balls into the target bucket 2305 .
Some of the above-described functions may be defined by instructions that are stored on storage media (i.e., non-transitory computer-readable storage media). The instructions may be retrieved and executed by the processor of the computer on which the system is resident. Some examples of storage media are memory devices, tapes, disks, integrated circuits, and servers. The instructions are operational when executed by the processor to direct the processor to operate in accordance with the invention. Those skilled in the art are familiar with instructions, processor(s), and storage media.
It should be noted that any hardware platform suitable for performing the processing described herein is suitable for use with the invention. The terms “computer-readable storage media” and “storage media” as used herein refer to any non-transitory medium or media that participate in providing instructions to a CPU for execution. Such media can take many forms, including, but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical or magnetic disks, such as a fixed disk. Volatile media include dynamic memory, such as system RAM. Transmission media include coaxial cables, copper wire and fiber optics, among others, including the wires that comprise an embodiment of a bus.
Common forms of computer-readable storage media include, for example, a floppy disk, a flexible disk, a hard disk, magnetic tape, any other magnetic medium, a CD-ROM disk, digital video disk (DVD), any other optical medium, a physical medium with patterns of marks or holes, a RAM, a PROM, an EPROM, an EEPROM, a FLASHEPROM, any other memory chip or cartridge, or any other storage medium from which a computer can read.
The embodiments described herein are illustrative of the present invention. As these embodiments of the present invention are described with reference to illustrations, various modifications or adaptations of the methods and or specific structures described may become apparent to those skilled in the art in light of the descriptions and illustrations herein. All such modifications, adaptations, or variations that rely upon the teachings of the present invention, and through which these teachings have advanced the art, are considered to be within the spirit and scope of the present invention. Hence, these descriptions and drawings should not be considered in a limiting sense, as it is understood that the present invention is in no way limited to only the embodiments illustrated. | A table tennis game table may include one or more automated ball serving guns and an automated score announcing system. Remote control actuators may be provided for one or more users to operate the features of the table. The system may be adjusted manually or remotely to correct mistakes, and may be used in multiple modes. Alternatively, the automated ball serving guns and automated score announcing system may be adapted to a standard after market table. | 0 |
FIELD OF THE INVENTION
This invention relates to tetragonal zirconia containing materials; and more particularly to the prevention of low temperatures degradation therein.
DESCRIPTION OF THE PRIOR ART
Ceramic materials appointed for structural applications are required to exhibit high hardness, strength, and fracture toughness. One class of materials meeting these criteria are those containing zirconia as a constituent thereof. Zirconia imparts toughness to a material through a stress-induced phase transition from the metastable tetragonal form to the equilibrium monoclinic phase. The transition is accompanied by volume increase of approximately 5 percent, which changes the stress field around an advancing crack. The energy needed to propagate the crack is increased, therefore increasing toughness.
In order to retain zirconia in its tetragonal form at room temperature after sintering, stabilizing oxides like Y 2 O 3 and CeO 2 are added in amounts ranging from 1 to 4 mol. % (Y 2 O 3 ). The larger the grain size of the sintered material the more unstable the tetragonal phase becomes. The stability of the tetragonal phase is the major factor determining the degree of toughening the sintered zirconia-containing material will achieve. The toughness of such material increases as the stability of the tetragonal phase decreases.
Zirconia ceramics containing yttria as the stabilizing agent have been shown to have the highest strengths of any material yet tested. The main drawback of these materials is the difficulty of controlling the metastable nature of the tetragonal phase. The same transformation which imparts high strength and toughness can cause a large reduction in strength when the material is exposed to temperatures in the range of 190° C. to 475° C. for an extended period of time. The exact mechanism for this degradation is not yet understood, but it is always accompanied by a large (>70%) monoclinic content on the surface and has been shown to be accelerated by the presence of polar liquids like water. The transformation originates at the surface causing cracks which proceed into the bulk during the degradation process.
The most direct method of preventing degradation of tetragonal zirconia containing materials is to decrease the metastability of the tetragonal phase by either increasing yttria content or by decreasing the grain size. (See T. Sato, et. al., J. Materials Science, 1985, 20, 1466-1470). Each of these methods has the disadvantage of reducing the desired high toughness of the material. Also, the composition and firing ranges have to be significantly narrowed, increasing the difficulty of reliable processing. Another method of preventing degradation of tetragonal zirconia containing materials is to effect a change in the surface region thereof as taught by U.S. Pat. No. 4,525,464 to Claussen et al. The stability of the surface region is increased by increasing the surface stabilizer content. A zone of fully stabilized zirconia is created on the surface by sintering the material in a bed of the stabilizing oxide. The stabilization of surfaces by this method is expensive, and is particularly difficult when such surfaces have complex shapes or sharp corners.
There remains a need in the art for an economical, reliable method for protecting zirconia containing material from low temperature degradation without sacrificing bulk toughness.
SUMMARY OF THE INVENTION
The present invention provides a method that is economical to practice and reliable in operation, and by way of which low temperature degradation in tetragonal zirconia, or in materials containing tetragonal zirconia, is virtually eliminated. The method of the invention results in preparation of a ceramic body having a surface region that contains tetragonal zirconia and is partially stabilized with yttria and, optionally, ceria. Generally stated, the method comprises the steps of sintering the body to at least 95% theoretical density at a temperature below about 1550° C.; abrading a portion of the surface region to impart strain and deformation thereto; and heat treating the surface region to recrystallize thereon tetragonal strain free grains of yttrium oxide zirconium oxide, the content of yttrium on the surface region being substantially the same as the average content of yttrium in the ceramic body, such that the surface region is covered with a thin layer of tetragonal grains.
In this manner, a fine grained surface layer of stable tetragonal zirconia is created on bulk metastable tetragonal zirconia which prevents the low temperature surface transformation to monoclinic from occurring. The creation of the fine grain surface layer involves the recrystallization of the surface region through a straining and annealing process. In order for the recrystallization to occur, the surface must first be plastically deformed within a region to increase the degree of strain energy present. Once deformed, the surface region is annealed within a temperature range that allows the nucleation and growth of new strain free grains of controllable size.
In addition, the invention provides a ceramic body having a surface region that contains tetragonal zirconia. The ceramic body is partially stabilized with yttria and, optionally, ceria. Substantially the entire surface region is composed of recrystallized tetragonal strain free grains of yttrium oxide zirconium oxide. The content of yttrium in the surface region is substantially the same as the average content of yttrium in the ceramic body, and the surface region is covered with a thin layer of stable tetragonal grains.
The recrystallization process can be readily performed in a single post-sintering annealing step. Structural ceramics containing tetragonal zirconia are generally machined using diamond wheels. An abraded surface of this type is ideal for recrystallization. Advantageously, complicated parts do not require special treatment as is previously the case for previous surface stabilization techniques. Also, the ceramic body can be provided with a large grain size for optimum toughness while, at the same time, its surface is provided with recrystallized tetragonal strain free grains, having much smaller grain size, that protect the body against low temperature transformation at the surface.
The increased toughness of the ceramic body, together with the increased protection against low temperature surface degradation provided by the recrystallized surface layer thereof, make the ceramic body especially suited for use in structural components such as valves, engine housings, piston chambers, and the like which, during operation, are frequently exposed to temperatures in the range of 190° C. to 400° C. for prolonged periods of time.
DETAILED DESCRIPTION OF THE INVENTION
Transformation toughened ceramics are formed by fabricating nominally 100% tetragonal zirconia bodies using stabilizing cations (i.e. Y 2 O 3 , CeO 2 ) or by incorporating a significant volume percent (5 to 40%) of tetragonal zirconia into the composition. Typically, a particular composition is selected to maximize toughness by adjusting the parameters which control the transformability of the tetragonal phase. The upper limit of toughness is determined by the provision that the tetragonal phase is stable enough to resist the low temperature transformation to monoclinic.
In accordance with the invention, a method is provided whereby the low temperature transformation to monoclinic is prevented within a surface region of the ceramic body, allowing a much greater range of toughness to be achieved in the bulk portion of the body. This technique is compatible with any material containing tetragonal zirconia stabilized with yttria and, optionally, ceria and is particularly suited for a body composed entirely of tetragonal zirconia. Preferably, the ceramic body has a composition consisting essentially of about 2 to 3 mol % yttria, about 0 to 6 wt % ceria, 0 to about 40 wt % alumina, the balance being zirconia plus incidental impurities.
The prevention of the low temperature transformation to monoclinic is brought about by the creation of a protective stable surface layer of fine grained tetragonal phase through recrystallization. By recrystallization is meant that the fine grained surface is the result of growth of new strain free grains from a substantially deformed surface. These recrystallized strain free grains are quite small, having an average grain size ranging from about 0.1 to 0.5 micrometers.
The recrystallization process requires both deformation and high temperature annealing steps. The specific temperature treatment employed depends on the state of the initial tetragonal phase including grain size, stabilizer content, matrix properties, and degree of deformation.
Typically, in heat treating, the ceramic body is heated at a heating rate of about 100° to 500° C./hr to a temperature within a range of about 1000° to 1400° C. The temperature is maintained within the 1000° to 1400° C. range for a time ranging from about 0.5 to 3.0 hrs. The body is then cooled to room temperature at a cooling rate of about 200° to 600° C./hr.
More specifically, in accordance with the invention there is provided a preferred process which is compatible with the processing of most transformation toughened ceramics. The tetragonal zirconia containing material utilized in this process has a composition consisting essentially of 2.45 mol. % Y 2 O 3 /ZrO 2 sintered to at least 98% theoretical density at temperatures below 1550° C. In conducting the preferred process, the surface of the tetragonal zirconia material is abraded with either a 220 or 180 mesh diamond wheel at a surface velocity of 5200 feet per minute with a downfeed rate of 0.0102 mm/pass. The body is then heat treated by heating it at a rate of 200° C./hr to a temperature of 1300° C.; maintaining the temperature at 1300° C. for 1 hour; and cooling the body to room temperature at a cooling rate of 300° C./hr. A body so treated will contain a fine grained (<0.2 u) surface structure. X-ray diffraction patterns of this surface show only the tetragonal form of zirconia.
Ceramic bodies processed in accordance with the present invention have recrystallized on a surface region thereof tetragonal strain free grains in the form of a thin layer. The thickness of this layer of tetragonal grains ranges from about 0.5 to 2 micrometers, and preferably from about 1 to 1.5 micrometers. The surface region of such bodies is 100% in the tetragonal lattice modification and the strain free grains have an average grain size ranging from about 0.1 to 0.5 micrometers.
The abrading step used in effectuating the recrystallization process of the invention is typically a grinding procedure, but can involve alternative mechanical means (i.e. sand blasting) of imparting significant deformation and strain to the surface region of the ceramic body. Materials harder than zirconia, such as alumina, silicon carbide, boron carbide, diamond and the like are suitable for use as grinding media in abrading the surface region.
The heat treatment (annealing) schedule (i.e. time and temperature) for the surface region will vary depending on (1) the state of the deformed tetragonal zirconia i.e. whether the surface region is substantially 100% in the tetragonal lattice modification or is a component in a matrix, (2) the prior heat treatment experienced by the ceramic body (i.e. the grain size of the ceramic body), and (3) the impurity level (particularly of silica) of the ceramic body. In general, the heat treatment temperature is inversely proportional to the sintering temperature, that is, it is decreased as the sintering temperature (and hence the grain size) is increased. Too low an annealing temperature (below about 1000° C.) will prevent a coherent recrystallized layer from forming on the surface region, thus negating any advantageous effect produced by grain size reduction at the surface region. Too high an annealing temperature (above about 1450° C.) causes recrystallized surface grains to grow to a size which are unstable and will transform to the monoclinic form upon subjection of the surface region to low temperature aging. In addition, the upper limit of the heat treatment temperature is markedly effected by the impurity level of components such as silica. At temperatures above 1400° C., the presence of silica at grain boundaries causes the redistribution of yttria in the body, with the result that the surface region becomes enriched in yttria at the expense of the bulk. This effect is highly undesirable; consequently, high purity material having low silica content is preferred.
The composition of the ceramic body is not limited to the 100% tetragonal embodiment. Compositions containing mixed stabilizers like ceria and yttria, and those containing strengthening additives like alumina, are also suitable for use with the process of the invention. Materials containing tetragonal zirconia as a toughening agent in a ceramic matrix should also respond well to the surface treatment provided by the present process. The usable toughness range of these materials should be extended by employing the process of this invention.
The following examples are presented to provide a more complete understanding of the invention. The specific techniques, conditions, materials proportions and reported data set forth to illustrate the principles and practice of the invention are exemplary and should not be construed as limiting the scope of the invention.
EXAMPLE 1
A sample of commercially available 2.45 mol % Y 2 O 3 /ZrO 2 powder was uniaxially pressed at 100 MPa and fired in air at 1400° C. for 3 hours. The sample was surface ground on one side with a LECO 220 mesh diamond wheel and polished on the other side (1 u diamond paste). The piece was reheated to 1300° C. for 3 hours to recrystallize the ground (deformed) side. After aging the sample for 100 hours at 200° C. in air, the surfaces were analyzed by X-ray diffraction. The polished (untreated) side contained about 70% monoclinic phase while the recrystallized (ground and annealed) side was 100% tetragonal, showing no degradation.
EXAMPLE 2
A sample of high purity 2.5 mol % Y 2 O 3 /ZrO 2 was isopressed at 275 MPa and fired at 1550° C. for 3 hours. The surface was polished down to 1 u diamond paste. Several scratches were put in the surface using 220 mesh SiC paper. The surface was then annealed at 1300° C. for 3 hours. The microstructure was examined by SEM. The polished areas contained grains in the 1 u size range. In the scratches the deformed region recrystallized into fine grains on the order of 0.1 to 0.2 u in size.
EXAMPLE 3
A batch of 2.5 mol % Y 2 O 3 /ZrO 2 was slip cast into blocks and fired to 1550° C. for 1 hour. The blocks were sliced into 3×6×50 mm bars for strength testing and 5.08×12.7×57.15 mm bars for IZOD impact testing. One set of bars was surface ground on all sides with a 220 mesh diamond wheel and then annealed at 1200° C. for 1 hour to develop the recrystallized surfaces. These bars were then aged at 200° C. in air for 1000 hours. The aged bars showed no strength degradation; their strengths (960 MPa) were slightly higher then the unaged bars (750 MPa). The impact strengths showed the same trend; unaged 7.7 ft-lbs. and aged 10.7 ft-lbs. In either, case no degradation was seen on the protected samples.
EXAMPLE 3
A cylinder of high purity 2.5 mol % Y 2 O 3 /ZrO 2 was formed by isostatically pressing at 275 MPa followed by sintering at 1500° C. for 2 hours to achieve 99% density. After sintering the cylinder was sliced into 2 mm thick disks. The disks were then surface ground using a 220 mesh diamond wheel at 5200 surface feet per minute with a downfeed rate of 0.0102 mm/pass on one side. The other side was polished down to a 1 u diamond paste. Each sample was then annealed at a temperature ranging from 900° C. to 1500° C. for 2 hours. The annealed pieces were placed in a low temperature furnace and aged for 20 hours at 200° C. X-ray diffraction was used to analyze the phase content of both surfaces of each piece after the low temperature age (see Table I).
TABLE I______________________________________Recrystallization Percent Monoclinic Content on Aged SurfacesTemperature °C. Polished Surface Ground Surface______________________________________Control (norecrystallization 67.7 35.3anneal)900 61.2 12.71100 76.4 1.31200 50.1 ND*1300 72.9 ND1400 64.2 1.41500 63.9 28.4______________________________________ *ND = not detectable
EXAMPLE 5
Isopressed disks of 2 mol % Y 2 O 3 /ZrO 2 containing 2, 4, 6 wt % CeO 2 and 5, 10, 15 wt % Al 2 O 3 were prepared and fired at 1450° and 1500° C., respectively. Surface of these materials were polished and ground as described in Example 1. After aging at 200° C. for 100 hours in air, all surfaces had transformed substantially from tetragonal to monoclinic phase. The samples were then recrystallized at 1300° C. for 3 hours (all surfaces transformed back to tetragonal) and re-aged at 200° C. for 100 hours. The polished side of these materials transformed to monoclinic, while the ground (recrystallized) side remained undegraded (tetragonal).
Having described the invention in rather full detail, it will be understood that such detail need not be strictly adhered to but that various changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the present invention as defined by the subjoined claims. | A ceramic body has a surface region that contains tetragonal zirconia. The body is partially stabilized with yttria and, optionally, ceria. Substantially the entire surface region is composed of recrystallized tetragonal strain free grains of yttrium oxide zirconium oxide. The content of yttrium in the surface region is substantially the same as the average content of yttrium in the ceramic body, and the surface region is covered with a thin layer of stable tetragonal grains. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority of Taiwan Patent Application No. 98141855, filed on Dec. 8, 2009, the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an electronic system, and more particularly to an electronic system including a shift register.
2. Description of the Related Art
FIG. 1 is a schematic diagram of a conventional shift register. The shift register 100 is composed of D-type flip-flops 101 - 104 . The D-type flip-flops 101 - 104 are connected in series with one another. The D-type flip-flops 101 - 104 shift a start signal START according to rising edges of a clock signal CLK.
FIG. 2 is a schematic diagram of another conventional shift register. The shift register 200 comprises shift register cells 201 - 204 . The shift register cells 201 - 204 shift a start signal START according to clock signals CLK and XCLK.
BRIEF SUMMARY OF THE INVENTION
An exemplary embodiment of an electronic system comprises a power transforming unit and a display panel. The power transforming unit provides an operational voltage. The display panel receives the operational voltage and comprises a gate driver, a source driver, a first pixel and a second pixel. The gate driver is coupled to a first gate line and a second gate line and comprises a shift register and a signal generating unit. The shift register comprises a first transistor, a first trigger circuit, a second transistor, and a second trigger circuit. The first transistor receives a first input signal. The first trigger circuit is serially connected to the first transistor between a first level and a second level and is connected with the first transistor in a first node. The second transistor receives a second input signal inverted to the first input signal. The second trigger circuit receives the level of the first node, is serially connected to the second transistor between a third level and the second level, and is connected with the second transistor in a second node. The signal generating unit provides the first, the second, and the third levels. The source driver is coupled to a first data line and a second data line. The first pixel is coupled to the first gate line and the first data line. The second pixel is coupled to the second gate line and the second data line.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be more fully understood by referring to the following detailed descriptions and examples with references made to the accompanying drawings, wherein:
FIG. 1 is a schematic diagram of a conventional shift register;
FIG. 2 is a schematic diagram of another conventional shift register;
FIG. 3A is a schematic diagram of an exemplary embodiment of a shift register of the invention;
FIG. 3B is a timing diagram of the output signals OUT 1 -OUT 4 ;
FIG. 4A is a schematic diagram of another exemplary embodiment of a shift register of the invention;
FIG. 4B is a timing diagram of the output signals OUT 1 -OUT 4 shown in FIG. 4A ;
FIG. 5 is a schematic diagram of another exemplary embodiment of a shift register of the invention;
FIG. 6A is a schematic diagram of an exemplary embodiment of the trigger circuit shown in FIG. 3A and FIG. 4A ;
FIG. 6B a schematic diagram of another exemplary embodiment of the trigger circuit;
FIG. 7 shows a control timing diagram of the trigger circuit;
FIG. 8A a schematic diagram of an exemplary embodiment of a gate driver;
FIG. 8B a schematic diagram of another exemplary embodiment of a gate driver;
FIG. 9 a schematic diagram of an exemplary embodiment of the switching unit shown in FIG. 8 ; and
FIG. 10 a schematic diagram of an exemplary embodiment of an electronic system.
DETAILED DESCRIPTION OF THE INVENTION
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
FIG. 3A is a schematic diagram of an exemplary embodiment of a shift register of the invention. The shift register comprises various shift register cells. The invention does not limit the number of the shift register cells. For clarity, FIG. 3A only shows four shift register cells 311 - 314 .
As shown in FIG. 3A , the shift register cell 311 comprises a transistor MP 1 and a trigger circuit TP 1 . The transistor MP 1 receives an input signal XIN. The trigger circuit TP 1 and the transistor MP 1 are coupled to a node NP 1 . The trigger circuit TP 1 is serially connected to the transistor MP 1 between levels V 1 and V 2 . In one embodiment, the level V 1 is an alternating current (AC) level and inverted to the input signal XIN. In addition, the level V 2 is maintained in a low level, such as a grounding level.
When a start signal START activates the trigger circuit TP 1 , the trigger circuit TP 1 outputs the level V 2 to the node NP 1 . When the start signal START does not activate the trigger circuit TP 1 , the transistor MP 1 outputs the level V 1 to the node NP 1 .
The shift register cell 312 comprises a transistor MP 2 and a trigger circuit TP 2 . The transistor MP 2 receives an input signal IN. The trigger circuit TP 2 and the transistor MP 2 are coupled to a node NP 2 . The trigger circuit TP 2 is serially connected to the transistor MP 2 between levels V 3 and V 2 . In one embodiment, the level V 3 is an AC level and inverted to the input signal IN. In this embodiment, the input signal IN is inverted to the input signal XIN. In one embodiment, the level V 1 is the same as the input signal IN and the level V 3 is the same as the input signal XIN.
When the level (i.e. an output signal OUT 1 ) of the node NP 1 is sufficient to activate the trigger circuit TP 2 , the trigger circuit TP 2 outputs the level V 2 to the node NP 2 . When the level of the node NP 1 is not sufficient to activate the trigger circuit TP 2 , the transistor MP 2 outputs the level V 3 to the node NP 2 .
The shift register cell 313 comprises a transistor MP 3 and a trigger circuit TP 3 . The transistor MP 3 receives the input signal XIN. The trigger circuit TP 3 is connected with the transistor MP 3 in a node NP 3 . The trigger circuit TP 3 is serially connected to the transistor MP 3 between the levels V 1 and V 2 . Since a function of the level of the node NP 3 is similar to a function of the level of the node NP 1 , the description of the function of the level of the node NP 3 is omitted for brevity.
The shift register cell 314 comprises a transistor MP 4 and a trigger circuit TP 4 . The transistor MP 4 receives the input signal IN. The trigger circuit TP 4 and the transistor MP 4 are coupled to a node NP 4 . The trigger circuit TP 4 is serially connected to the transistor MP 4 between the levels V 3 and V 2 . Since a function of the level of the node NP 4 is similar to a function of the level of the node NP 2 , the description of the function of the level of the node NP 4 is omitted for brevity.
In this embodiment, the transistors MP 1 -MP 4 are P-type transistors. As shown in FIG. 3A , the gates of the transistors MP 1 and MP 3 receive the input signal XIN. The sources of the transistors MP 1 and MP 3 receive the level V 1 . The drain of the transistor MP 1 is coupled to the node NP 1 . The drain of the transistor MP 3 is coupled to the node NP 3 . The gates of the transistors MP 2 and MP 4 receive the input signal IN. The sources of the transistors MP 2 and MP 4 receive the level V 3 . The drain of the transistor MP 2 is coupled to the node NP 2 . The drain of the transistor MP 4 is coupled to the node NP 4 .
Furthermore, the levels of the nodes NP 1 -NP 4 are served as output signals OUT 1 -OUT 4 of the shift register 310 , respectively. FIG. 3B is a timing diagram of the output signals OUT 1 -OUT 4 . When a trigger circuit is activated, a corresponding output signal is equal to a low level (i.e. the level V 2 ). When the trigger circuit is not activated, a corresponding output signal is equal to a high level. In this embodiment, only one output signal is equal to the low level at the same time.
FIG. 4A is a schematic diagram of another exemplary embodiment of a shift register of the invention. FIG. 4A is similar to FIG. 3A with the exception that trigger circuits TN 1 -TN 4 are coupled to N-type transistors MN 1 -MN 4 , respectively. Taking the transistors MN 1 and MN 3 as an example, the gates of the transistors MN 1 and MN 3 receive the input signal XIN. The sources of the transistors MN 1 and MN 3 receive the level V 2 . The drain of the transistor MN 1 is coupled to the node NN 1 . The drain of the transistor MN 3 is coupled to the node NN 3 . Additionally, the gates of the transistors MN 2 and MN 4 receive the input signal IN. The sources of the transistors MN 2 and MN 4 receive the level V 2 . The drain of the transistor MN 2 is coupled to the node NN 2 . The drain of the transistor MN 4 is coupled to the node NN 4 .
When the start signal START activates the trigger circuit TN 1 , the trigger circuit TN 1 outputs the level V 1 to the node NN 1 . When the start signal START does not activate the trigger circuit TN 1 , the transistor MN 1 outputs the level V 2 to the node NN 1 . Similarly, when the level (i.e. the output signal OUT 1 ) of the node NN 1 is sufficient to activate the trigger circuit TN 2 , the trigger circuit TN 2 outputs the level V 3 to the node NN 2 . When the level of the node NN 1 is not sufficient to activate the trigger circuit TN 2 , the transistor MN 2 outputs the level V 2 to the node NN 2 .
Furthermore, the levels of the nodes NN 1 -NN 4 are served as the output signals OUT 1 -OUT 4 of the shift register 410 . FIG. 4B is a timing diagram of the output signals OUT 1 -OUT 4 shown in FIG. 4A . In this embodiment, when a trigger circuit is activated, a corresponding output signal is in a high level. When the trigger circuit is not activated, the corresponding output signal may be in a low level. As shown in FIG. 4B , only one output signal is in the high level at the same time. In other words, only one trigger circuit is activated at the same time.
FIG. 5 is a schematic diagram of another exemplary embodiment of a shift register of the invention. FIG. 5 is similar to FIG. 4A with the exception that shift register cells 511 - 514 comprise P-type transistors MI 1 -MI 4 , respectively. Further, the levels V 1 and V 3 shown in FIG. 5 are different from the levels V 1 and V 3 shown in FIG. 4A . The levels V 1 and V 3 shown in FIG. 5 are direct current (DC) levels.
In this embodiment, the levels V 1 and V 3 shown in FIG. 5 are high, such as 10V and the level V 2 is low, such as 0V. Additionally, the input signal IN of FIG. 5 is inverted to the input signal XIN of FIG. 5 . The input signals IN and XIN are AC signals.
The shift register cell 511 comprises transistors MI 1 and MN 1 , and a trigger unit TI 1 . The transistors MI 1 and MN 1 are serially connected to the trigger unit TI 1 between the levels V 1 and V 2 . The trigger unit TI 1 and the transistor MN 1 are coupled to the node NN 1 . The gates of the transistors MI 1 and MN 1 receive the input signal IN.
In this embodiment, the source of the transistor MI 1 receives the level V 1 and the source of the transistor MN 1 receives the level V 2 . When the start signal START activates the trigger unit TI 1 , the level of the node NN 1 is equal to the level V 1 . When the start signal START does not activate the trigger unit TI 1 , the level of the node NN 1 is equal to the level V 2 .
The shift register cell 512 comprises transistors MI 2 and MN 2 , and a trigger unit TI 2 . The transistors MI 2 and MN 2 are serially connected to the trigger unit TI 2 between the levels V 3 and V 2 . The trigger unit TI 2 and the transistor MN 2 are coupled to the node NN 2 . The gates of the transistors MI 2 and MN 2 receive the input signal XIN.
In this embodiment, the source of the transistor MI 2 receives the level V 3 and the source of the transistor MN 2 receives the level V 2 . When the level of the node NN 1 is sufficient to activate the trigger unit TI 2 , the level of the node NN 2 is equal to the level V 3 . When the level of the node NN 1 is not sufficient to activate the trigger unit TI 2 , the level of the node NN 2 is equal to the level V 2 .
The shift register cell 513 comprises transistors MI 3 and MN 3 , and a trigger unit TI 3 . The transistors MI 3 and MN 3 are serially connected to the trigger unit TI 3 between the levels V 1 and V 2 . The trigger unit TI 3 and the transistor MN 3 are coupled to the node NN 3 . The gates of the transistors MI 3 and MN 3 receive the input signal IN. In this embodiment, the source of the transistor MI 3 receives the level V 1 and the source of the transistor MN 3 receives the level V 2 .
The shift register cell 514 comprises transistors MI 4 and MN 4 , and a trigger unit TI 4 . The transistors MI 4 and MN 4 are serially connected to the trigger unit TI 4 between the levels V 3 and V 2 . The trigger unit TI 4 and the transistor MN 4 are coupled to the node NN 4 . The gates of the transistors MI 4 and MN 4 receive the input signal XIN. In this embodiment, the source of the transistor MI 4 receives the level V 3 and the source of the transistor MN 4 receives the level V 2 .
As shown in FIG. 5 , the structures of all shift register cells are the same (e.g. each shift register cell comprises a P-type transistor, an N-type transistor, and a trigger unit). In some embodiment, any particular shift register cell in FIG. 5 can be replaced by anyone shift register cell in FIG. 3A or FIG. 4A , or any particular shift register cell in FIG. 3A or FIG. 4A can be replaced by anyone shift register cell in FIG. 5 .
The shift register cells in FIGS. 3A , 4 A, and 5 A execute a shifting action according to a small amount of input signals. Thus, complexity of the shift register can be reduced. Taking the shift register cell 311 shown in FIG. 3A as an example, the shift register cell 311 shifts the start signal START to generate the output signal OUT 1 according to the input signal XIN and the levels V 1 and V 2 .
In one embodiment, the input signal XIN is inverted to the level V 1 . In other words, one inverter is utilized to invert one of the input signals XIN and the level V 1 to generate an inverted input signal. Thus, the complexity of the shift register is reduced.
FIG. 6A is a schematic diagram of an exemplary embodiment of the trigger circuit shown in FIG. 3A and FIG. 4A . The trigger circuit shown in FIG. 3A or 4 A can be replaced by the trigger circuit shown in FIG. 6A . For clarity, FIG. 6A only shows the shift register cell 411 of FIG. 4A to describe a connection relationship between the trigger circuit TN 1 and the transistor MN 1 .
As shown in FIG. 6A , the trigger circuit TN 1 comprises a reset transistor MR and a capacitor C. The capacitor C is coupled between the gate and the drain of the reset transistor MR. In this embodiment, the reset transistor MR is an N-type transistor. Additionally, the trigger circuit TN 1 further comprises a current source CS and a setting transistor MS.
The current source CS provides a fixed current I. In this embodiment, the current source CS consists of a P-type transistor MI. As shown in FIG. 6A , the gate of the transistor MI receives a grounding level GND and the source of the transistor MI receives a high voltage VDD to provide the fixed current I.
The setting transistor MS receives the level V 1 and couples to the node NN 1 . In this embodiment, the setting transistor MS is utilized to increase the level of the node NN 1 such that the level of the node NN 1 is in a high level. Thus, the setting transistor MS is referred to as a pull-high transistor. In another embodiment, if the trigger circuit shown in FIG. 6A is applied in FIG. 3A , the setting transistor MS is coupled between the node NP 1 and the level V 2 to reduce the level of the node NP 1 such that the level of the node NP 1 is in a low level. AT this time, the setting transistor MS is referred to as a pull-low transistor.
Further, the start signal START shown in FIG. 6A represents an output signal of a previous shift register cell. The output signal OUT 1 shown in FIG. 6A represents a signal transmitted to the next shift register. Taking the shift register cell 413 shown in FIG. 4A as an example, the start signal START shown in FIG. 6A is the output signal OUT 2 shown in FIG. 4A . The output signal OUT 1 shown in FIG. 6A is the output signal OUT 3 shown in FIG. 4A .
FIG. 6B a schematic diagram of another exemplary embodiment of the trigger circuit. FIG. 6B is similar to FIG. 6A except for the addition of a transmitting transistor MT. The transmitting transistor MT transmits the fixed current I to the capacitor C. In this embodiment, the reset transistor MR is an N-type transistor and the setting transistor MS and the transmitting transistor MT are P-type transistors.
The reset transistor MR comprises a gate receiving the start signal START, a source receiving the level V 2 , and a drain coupled to the drain of the transmitting transistor MT. The setting transistor MS comprises a gate coupled to the drain of the transmitting transistor MR, a drain coupled to the node NN 1 , and a source receiving the level V 1 . The transmitting transistor MT comprises a gate receiving the start signal START, a source coupled to the current source CS and a drain coupled to the drain of the reset transistor MR.
FIG. 7 shows a control timing diagram of the trigger circuit. Since the control timing of FIG. 6A is similar to the control timing of FIG. 6B , FIG. 7 only shows the control timing of FIG. 6A . During the period P 1 , the start signal START is in a high level such that the reset transistor MR is turned on to reset the capacitor C. At this time, the gate voltage VG 1 of the setting transistor MS is low. Since the level V 1 is a low level, the setting transistor MS is turned off. During the period P 1 , the input signal XIN is a high level such that the transistor MN 1 is turned on.
During the period P 2 , the start signal is low, the transmitting transistor MR is turned off. Thus, the current source CS charges the capacitor C. During the period P 2 , the gate voltage VG 1 of the setting transistor MS is lower than the low level at the very start because the reset transistor MR is controlled from a turn-on state to a turn-off state. Then, the gate voltage VG 1 of the setting transistor MS is gradually increased because the capacitor C is charged. During the period P 2 , the setting transistor MS is turned on. Since the level V 1 is high, the setting transistor MS pulls the level (i.e. the output signal OUT 1 ) of the node NN 1 to a high level. At this time, since the input signal XIN is low, the transistor MN 1 is turned off.
During the period P 3 , the charge of the capacitor C is maintained in a preset value. Thus, the gate voltage VG 1 of the setting transistor MS is high. At this time, the reset transistor MR, the setting transistor MS, and the transistor MN 1 are turned off.
During the period P 4 , the input signal XIN is high such that the transistor MN 1 is turned on. Thus, the output signal OUT 1 is low. At this time, the reset transistor MR and the setting transistor MS are turned off.
Referring to FIG. 7 , the start signal START is shifted by the shift register of the invention. The shifted result is shown as the output signal OUT 1 . Since the shift register of the invention arrives to a shift function according to a small number of control signals. Thus, the complexity of the shift register can be reduced.
For example, the shift register 310 shown in FIG. 3A shifts the start signal START according to the levels V 1 -V 3 and the input signals XIN and IN. In one embodiment, when the level V 1 is inverted to the level V 2 , only one level (e.g. V 1 ) is required and utilized to generate the invented level (e.g. V 2 ). In another embodiment, when the level V 1 is equal to the input signal IN and the level V 2 is equal to the input XIN, only one level (e.g. V 1 ) is required and utilized to generate the inverted level (e.g. V 2 and XIN) and the non-inverted level (e.g. IN).
The invention does not limit the application field of the shift register. In one embodiment, the shift register is applied within a gate driver or a data driver of a display panel, but the disclosure is not limited thereto. In other embodiments, the shift register is combined with other circuits. For brevity, a gate driver is given as an example.
FIG. 8A a schematic diagram of an exemplary embodiment of a gate driver. The gate driver 800 is coupled to gate lines GL 1 -GL 4 . The invention does not limit the number of the gate lines. In this embodiment, only four gate lines are shown, but the disclosure is not limited thereto. Further, the gate driver 800 comprises a signal generating unit 810 , a shift register 830 , and a buffer unit 850 .
The signal generating unit 810 generates input signals XIN and IN and levels V 1 -V 3 according to input voltage V I . In one embodiment, the signal generating unit 810 is a level shifter. In another embodiment, the input signal XIN is inverted to the input signal IN. In this embodiment, the input signals XIN and IN are AC signals. In other embodiments the level V 1 is inverted to or equal to the level V 2 . In other words, the levels V 1 and V 2 are AC levels or DC levels.
The shift register 830 receives the signals output from the signal generating unit 810 to shift a start signal START. The shift register 830 may be the shift register shown in FIG. 3A , FIG. 4A , and FIG. 5 . The invention does not limit the structure of each shift register cell. In one embodiment, the structures of all shift register cells are the same. In another embodiment, the structures of a portion of shift register cells may be different from the structures of the remainder.
The buffer unit 850 increases the driving capability of the output signals OUT 1 -OUT 4 of shift register 830 such that the output signals OUT 1 -OUT 4 of shift register 830 is capable of driving the pixels coupled to the gate lines GL 1 -GL 4 . In this embodiment, the buffer unit 850 comprises buffer strings 851 - 854 . The buffer strings 851 - 854 are composed of various buffers.
FIG. 8B a schematic diagram of another exemplary embodiment of a gate driver. The gate driver 800 ′ comprises a buffer unit 820 , a shift register 840 , a switching unit 860 and a signal generating unit 880 . In this embodiment, the shift register 840 is the shift registers shown in FIG. 3A , FIG. 4A and FIG. 5 .
The signal generating unit 880 comprises level shifters 882 and 884 . The level shifter 882 generates a signal S BIN to a buffer string 821 . The level shifter 884 generates input signals XIN and IN and levels V 1 -V 3 to the shift register 840 . In other embodiments, the signal generating unit 880 may comprise a single level shifter to generate signals required by the buffer unit 820 and the shift register 840 .
The buffer string 821 amplifies the driving capability of the signal S BIN and serves the amplified signal as an output signal S BOUT . The output signal S BOUT is transmitted to the switching unit 860 . The switching unit 860 selectively transmits the output signal S BOUT to the gate lines GL 1 -GL 4 according to the output signals OUT 1 -OUT 4 of the shift register 840 .
In this embodiment, since the buffer unit 820 only comprises a single buffer string (i.e. 821 ), the size of the gate driver 800 ′ can be substantially reduced. Additionally, the start signal START received by the shift register 840 can be provided by a timing controller (not shown), but the disclosure is not limited thereto.
FIG. 9 a schematic diagram of an exemplary embodiment of the switching unit shown in FIG. 8 . The switching unit 860 comprises switches 861 - 864 . The switches 861 - 864 are controlled by the output signals OUT 1 -OUT 4 of the shift register 840 . For example, assuming the output signals OUT 1 -OUT 4 shown in FIG. 9 are the output signals OUT 1 -OUT 4 shown in FIG. 4B .
When the output signal OUT 1 is in a high level, the switch 861 transmits the output signal S BOUT of the buffer string 821 to the gate line GL 1 . At this time, switches 862 - 864 transmit low levels AGND to the gate lines GL 2 -GL 4 . Thus, the levels of the gate lines GL 2 -GL 4 are low. Similarly, when the output signal OUT 2 is in a high level, the switch 862 transmits the output signal S BOUT of the buffer string 821 to the gate line GL 2 . At this time, switches 861 , 863 and 864 transmit low levels AGND to the gate lines GL 1 , GL 3 and GL 4 .
The gate drivers shown in FIG. 8A and FIG. 8B can be applied to an electronic system. The electronic system may be a personal digital assistant (PDA), a cellular phone, a digital camera (DSC), a television, a global positioning system (GPS), a car display, an avionics display, a digital photo frame, a notebook computer (NB), a personal computer (PC).
FIG. 10 a schematic diagram of an exemplary embodiment of an electronic system. The electronic system 1000 comprises a power transforming unit 1010 and a display panel 1030 . The power transforming unit 1010 converts an input power V IN to generate an operation voltage V OP . The display panel 1030 receives the operation voltage V OP to display an image. In one embodiment, the input power V IN is an AC power or a DC power. In this embodiment, the operation voltage V OP is a DC voltage.
The display panel 1030 comprises a gate driver 1031 , a source driver 1033 and pixels P 11 ˜P mn . The gate driver 1031 provides scan signals to gate lines GL 1 ˜GL n . The source driver 1033 provides data signals to data lines DL 1 ˜DL n . The pixels P 11 ˜P mn receives the data signals according to the scan signals of the gate lines GL 1 ˜GL n and display the corresponding brightness according to the data signals.
In one embodiment, the gate driver 1031 sequentially activates the gate lines GL 1 ˜GL n . Thus, the gate driver 1031 requires a shift register. In another embodiment, the source driver 1033 sequentially provides data signals to data lines DL 1 ˜DL n . Thus, the source driver 1033 also requires a shift register. The gate driver 1031 and the source driver 1033 can utilize the shift register shown in FIG. 3A , FIG. 4A or FIG. 5 . In addition, since the application of the scan signals provided by the gate driver 1031 and the application of the data signals provided by the source driver 1033 are well known to those skilled in the field, such descriptions are omitted for brevity.
While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | An electronic system including a shift register is disclosed. The shift register includes a first transistor, a first trigger circuit, a second transistor, and a second trigger circuit. The first transistor receives a first input signal. The first trigger circuit is serially connected to the first transistor between a first level and a second level and is connected with the first transistor in a first node. The second transistor receives a second input signal inverted to the first input signal. The second trigger circuit receives the level of the first node, is serially connected to the second transistor between a third level and the second level, and is connected with the second transistor in a second node. | 6 |
This Application claims the benefit of U.S. Provisional Application No. 60/134,630, filed May 18, 1999.
FIELD OF THE INVENTION
This invention relates generally to devices used by law enforcement agencies and the like for puncturing the rubber tires of a motor vehicle, thereby slowing down and eventually stopping such motor vehicle. More particularly, this invention relates to an improved tire puncturing device which utilizes a tire deflating spike which is constructed and configured so as to facilitate the flow of air out of a rubber vehicle tire once the rubber tire is punctured by the deflating spike. It also relates to an array or an assembly having a plurality of such deflating spikes for use with the device.
BACKGROUND OF THE INVENTION
It has long been recognized that it is occasionally necessary for law enforcement agencies to impede and altogether stop the movement of a run-away motor vehicle. Direct pursuit of such vehicles is often necessary, but brings with it concerns for public safety when such pursuits lead through city streets and other populated areas. Because such pursuits can also result in high speed chases, the safety of the pursuers is also a concern.
As a safer alternative to the direct pursuit of such vehicles, it has been recognized that strategic placement of tire deflating mechanisms in the path, or the anticipated path, of such run-away motor vehicles can effectively impede and stop the movement of them. Such portable tire deflating mechanisms can be deployed with relative ease and have taken several forms in recent years. One such mechanism is a multiple blade system whereby a plurality of blades, which blades are biased in the direction of the oncoming motor vehicle, are deployed. See, for example, U.S. Pat. No. 5,588,774 issued to Behan. Other systems have been used which utilize what amount to large hollow needles or syringes. See, for example, U.S. Pat. No. Re. 35,373 issued to Kilgrow et al. Still other systems utilize pyramidal spikes. See, for example, U.S. Pat. No. 5,536,109 issued to Lowndes. While each of these systems is, in the experience of this inventor, useful in its own right, each such array has functional limitations when the deflating mechanisms are confronted with the prospect of stopping a motor vehicle fitted with modem tires of the multiple layered, steel belted, self-sealing type. Such tires are specifically designed and configured to resist and possibly completely neutralize tire puncturing obstacles, including those intended as well as unintended. In the experience of this inventor, blade arrays have the drawback that, while they may cut through the rubber tread, a sharp blade will not be able to cut through several mesh steel wire belts thereby completely frustrating the tire deflating intention of the blade array device. Similarly, a needle-like or syringe-like puncturing device may even remain within the tire, but to no adverse result if a plug of rubber tire material becomes lodged within the inner void of the puncturing device, much the same as a cookie cutter can and does. Finally, other deflating device structures may remain in the tire, but to no avail and with no way to remove air from the tire until the deflating device becomes dislodged from the tire. Another safety concern arises with the use of such devices. And that is that such devices may eventually be dislodged and thrown from the motor vehicle tires they have impaled, thereby causing a safety concern for those in pursuit of such vehicles.
SUMMARY OF THE INVENTION
It is, therefore, a principal object of this invention to provide a new, useful and uncomplicated device for quickly and efficiently puncturing and deflating the rubber tires of a motor vehicle. It is a further object of this invention to provide such a tire deflating device which requires only a minimal number of elements and which effectively enhances air flow from the tire along the outside of the device and then transfers the air flow to the interior of the device. It is yet another object of this invention to provide such a device which can be readily used in a variety of tire deflating arrays and which effectively punctures most, if not all, modem inflatable rubber tire constructions. It is still another object of this invention to provide such a device which remains imbedded in the rubber tire until removal is desired or required. It is still another object of this invention to provide such a device which minimizes the fracturing of puncturing device tips and which avoids any rubber tire material plug from being created in the tire puncturing process.
The present invention has obtained these objects. It provides for a rubber tire puncturing and deflating device which is insertable within and removable from a holder of an array of such devices. The tire puncturing and deflating device of the present invention comprises a metal spike having a plurality of sharp, fluted edges which are functionally adapted for puncturing a rubber tire as the tire passes over the spike. As the rubber tire moves away from the spike assembly or array, the fluted spike is withdrawn from the holder and remains imbedded in the tread of the tire. The spike of the present invention includes a plurality of grooves which extend along the body of the spike to allow pressurized air escaping from the tire to run along the spike grooves and to a plurality of air flow vents. Each air flow vent is an access opening to the interior of the spike which allows the pressurized air to continue to flow through the spike and out of the tire until the tire is partially or even completely deflated. The foregoing and other features of the device of the present invention will be further apparent from the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a device using an array of the tire puncturing and deflating spikes which are constructed in accordance with the present invention.
FIG. 2 is an enlarged vertical section through one of the puncturing and deflating spikes shown in FIG. 1 and further showing, in particular, an exploded view of one embodiment of the spike seat assembly.
FIG. 3 is an enlarged vertical view of the puncturing and deflating spike shown in FIG. 2 .
FIG. 4 is a perspective view of the puncturing and deflating spike shown in FIG. 3 .
FIG. 5 is an enlarged top plan view of the puncturing and deflating spike shown in FIG. 3 .
FIG. 6 is an enlarged vertical view of the puncturing and deflating spike shown in FIG. 3 .
FIG. 7 is an enlarged bottom plan view of the puncturing and deflating spike shown in FIG. 3 .
FIG. 8 is a greatly enlarged top plan view of the puncturing and deflating spike shown in FIG. 3 .
FIG. 9 is a vertical section of the spike shown in FIG. 6 and taken along Line 9 — 9 in FIG. 8 .
DETAILED DESCRIPTION
Referring now to the drawings in detail, FIG. 2 shows a preferred embodiment of a puncturing and deflating spike, generally identified 10 , which is constructed in accordance with the present invention. As shown in FIG. 1, an array of such spikes 10 is included in a scissors-like assembly, generally identified 20 , which includes rotatably attached base members 21 , 22 . In this fashion, the assembly 20 can be significantly reduced in size and can be transported between locations when such is desired or required. It also allows the assembly to be used over and over again. While disclosed as a preferred embodiment, it should be understood that any number of such expandible and portable arrays could be constructed without deviating from the scope of the present invention.
As shown in FIG. 2, the assembly base member 3 is fitted with a number of spike holders 1 . The spike holder 1 of the present invention is made of a rigid plastic material. The spike holder 1 is attached to the base member 3 by virtue of a screw 5 and nut 4 used in combination. It should also be mentioned that this inventor has configured a base member 3 which is constructed with an integrally formed spike holder 1 , thereby eliminating the need for the extra screw 5 and nut 4 as shown. The critical function performed by either spike holder configuration is that the spike 10 be retained within the spike holder void 2 until the spike 10 is ready to be deployed by the assembly 20 . To that end, the puncturing and deflating spike 10 of the present invention includes a cylindrical spike base 11 which is functionally adapted to fit within the spike holder void 2 . The spike base 11 is fitted with a rubber ring 8 which helps retain the spike 10 in position. This inventor has also experienced success by utilizing a viscous silicon rubber sleeve or band which is functional throughout a wide range of temperatures in retaining the spike base 11 in place and allowing it some movement within the spike holder 1 .
As also shown in FIG. 2, the puncturing and deflating spike 10 of the present invention includes an upwardly extending plurality of spike blades 15 . Extending from the spike base 11 , the spike blades 15 come together and culminate in a spike point 17 . It is this spike point 17 which serves as the initial portion of the spike 10 to contact and pierce one or more of the rubber tires of a motor vehicle traveling over the assembly 20 . Each of the spike blades 15 of the spike 10 has a razor sharp blade edge 16 which helps slice through the rubber tire and through the steel bands contained within it as the weight of the vehicle bears upon the spike 10 . Situated between each of the spike blades 15 is a longitudinally extending spike groove 18 . Each spike groove 18 extends along the length of the spike 10 , beginning just below the point 17 of the spike 10 and ending just above the spike base 11 . To each side of each spike groove 18 is a spike fillet 14 . The purpose and function of this pair of spike fillets 14 will become more apparent further in this detailed description.
As previously disclosed, the tire puncturing and deflating spike 10 of the present invention includes a spike base void 12 . The spike base void 12 , in actuality, extends up and into the spike 10 and terminates at a point where the spike base void 12 meets, or intersects, the spike grooves 18 which run along the exterior of the spike 10 . In this fashion, the spike 10 of the present invention creates an air flow continuum which begins just below the point 17 of the spike 10 , runs along the number of spike grooves 18 and terminates in a like number of openings 13 to the spike base void 12 . It is this feature of the spike 10 of the present invention which aids in the tire deflating function of the spike 10 , even when used to pierce today's anti-leak tires. It should also be mentioned that the placement of the spike openings 13 in the spike 10 is such that strength of the uppermost portion of the spike 10 is maximized whereby the possibility of the air flow along the spike 10 being interrupted because of a collapsed spike 10 , or a portion of it, is minimized.
In application, a plurality of puncturing and deflating spikes 10 are loaded into the scissors assembly 20 , or other similar assembly. In this fashion, deployment of the assembly 20 across the anticipated path of the run-away motor vehicle by law enforcement officers makes the assembly 20 ready for action. When the rubber motor vehicle tire encounters the assembly 20 , the foremost portion of the vehicle tire encounters the spike point 17 . As the weight and forward progress of the tire forces it to roll over the spike 10 , the uppermost portion of the spike 10 is urged into and through the tire tread. The rubber tire is then pierced by the spike point 17 and the tread is split by the edges 16 of the spike blades 15 . As the spike 10 penetrates deeper into the rubber tire, the air chamber of the tire is pierced (not shown). In this fashion, air begins to be discharged from the tire along the spike grooves 18 of the spike 10 . Although the physical construction of many of today's rubber tires would have a tendency to close off the flow of air and seal the tire at its puncture site, the strategic presence of fillets 14 to each side of the spike grooves 18 serves to push the rubber tire material back from the innermost and deepest portions of the spike grooves 18 . In this fashion, air flow from the tire is initiated and maintained through and along the spike grooves 18 . The flow of air continues along the spike grooves 18 until it reaches the air flow vents 13 situated just above the spike base 11 . It should also be mentioned that, at some point during this process, the forward progress of the vehicle and its tires has resulted in the spike 10 being pulled away from the spike holder 1 with the assembly 20 being left behind and the spike 10 being firmly imbedded in the tire tread. In this fashion, air flow continues through the air flow vents 13 , and through the spike base void 12 , until the vehicle tire is substantially deflated or completely flat, at which point the forward progress of the vehicle is substantially impaired.
From the foregoing detailed description of the illustrative embodiment of the invention set forth herein, it will be apparent that there has been provided a new, useful and uncomplicated device for quickly and efficiently puncturing and deflating the rubber tires of a motor vehicle; which requires only a minimal number of elements and which effectively enhances air flow from the tire along the outside of the device and then transfers the air flow to the interior of the device; which can be readily used in a variety of tire deflating arrays and which effectively punctures most, if not all, modern rubber tire constructions; which remains imbedded in the rubber tire until removal is desired or required; and which minimizes the fracturing of puncturing device tips and which avoids any rubber tire material plug from being created in the tire puncturing process. | A metal spike has a plurality of sharp blades which are functionally adapted for puncturing a rubber tire as the tire passes over the spike. As the rubber tire moves away from the spike assembly or array, the spike is withdrawn from the holder and remains embedded in the tread of the tire. The spike includes a plurality of grooves which extend along the body of the spike and between adjacent blades to allow pressurized air escaping from the tire to run along the spike grooves and to a central internal airflow vent until the tire is partially or completely deflated. | 4 |
BACKGROUND AND SUMMARY
Collapsible containers for the administration of medical solutions are well known and are disclosed, by way of example, in U.S. Pat. Nos. 3,519,158, 4,140,162, 4,170,994, 4,136,694, 3,986,507, 3,304,977, 3,788,374, 3,364,930, 4,191,231, and 4,049,033. Typically, such a container when used for the storage and administration of parenteral fluids, has an inlet port as well as an outlet port. The outlet port is intended to be coupled to an administration set and is therefore commonly referred to as the administration or set port, whereas the inlet port is designed to permit the injection of therapeutic agents and nutrients into the partially prefilled container and is sometimes identified as the med port. Such a container may contain a partial filling of a sterile solution such as saline or dextrose to function as a diluent for the injected additive. The diluted drug or nutrient is then administered to a patient by means of the administration set which may be either directly or indirectly (i.e., through another parenteral solution set) coupled to the patient.
Maintaining the sterility of the fluid to be administered is clearly of major importance. It has been found, however, that careless or inattentive handling of a parenteral solution container, as the connections are being made for fluid administration or additive introduction through the respective outlet and inlet ports, may create significant risks of contamination. Such risks may be increased where emergency situations are presented that require quick manipulation of the various components, or where extended storage conditions causes components to stick together or to separate in a manner differently than intended. For example, a conventional administration port is often sealed by a soft rubber sealing disc held in place by a thin metal tear-off cap. Should the disc remain in place upon the neck of the container after the cap is removed, a user attempting to remove the disc might inadvertently touch and contaminate the sterile end surface of the neck, and such contamination may then be transferred to the contents of the container when the spike of the administration set is later plugged into the outlet port.
It is therefore an object to provide a container for medical solutions having improved inlet and outlet port constructions to reduce possibilities of contamination during storage and use, improve the ease of handling such a container when fluids are to be withdrawn or introduced and, at the same time, increase the ease and efficiency by which such a container may be manufactured. Since such containers are discarded following use, greater efficiencies in production resulting from improvements in construction tend to benefit patients in terms of both greater safety and lower cost.
In brief, the medical solution container of this invention may take the form of a collapsible bag having inlet and outlet ports. Each port has a tubular neck enclosed at its end by a metal cap. In the case of the outlet or administration port, a sealing disc or liner of soft elastomeric material is interposed between the end surface of the neck and the tear-off metal cap. The disc has planar surfaces and is provided with an integral circumferentially-extending rib projecting outwardly from its side surface. Ideally, the rib is spaced equal distances from the planar faces and has a diameter (in an undeformed state) greater than the inside diameter of the cap. Specifically, the rib should have a radial dimension less than half distance between each of the planar faces of the disc, and should have an axial dimension within the range of about 15 to 30% of the thickness of the disc. When the parts are assembled, the rib engages the inside surface of the cap and may be deformed thereby without, at the same time, causing any significant deformation of the disc's planar surface in sealing engagement with the end surface of the neck. Because of the frictional engagement between the disc and cap, the disc tends to be removed as the cap is torn away from the neck; however, should the disc happen to remain upon the neck after the cap is removed, the outwardly-projecting rib may be easily gripped or engaged by the fingers, and the disc may be lifted from the neck, without contacting and contaminating the sterile end surface of the neck.
The neck of the outlet port includes a tapered annular collar disposed within the neck and formed integrally therewith for slidably and sealingly engaging the hollow spike of an administration set. The opening defined by the collar (when the collar is unstretched) is smaller than the reduced portion of the bore adjacent thereto, thereby helping to assure effective contact between the collar and the inserted spike. The neck also includes an integral membrane adapted to be pierced by the spike, with the portion of the bore directly beneath (or proximal to) the membrane being of larger diameter to accommodate material of the membrane when such membrane is pierced, deformed, and displaced by the spike.
It has been found that a highly effective tapered annular collar may be formed in a simple molding operation if the distal wall portion of the neck is provided with an enlarged bore to accommodate outward flexing or stretching of the collar as the mold section is withdrawn, and if the inner and outer surfaces of the collar slope inwardly and distally (at an angle of about 5° to 15° measured internally) with the outer surface having a greater acute angle of slope (measured from a line extending in an axial direction). The differential between the angles of slope of the inner and outer surfaces should be within the range of 3° to 10° with a preferred differential being about 5°.
The tubular neck of the inlet or medication port has an internal annular shoulder facing the open distal end of the neck and is also provided with a plurality of longitudinal ribs projecting inwardly from the surface of the bore above (distal to) the shoulder. The ribs serve to guide the body of an elastomeric stopper into sealing engagement with the shoulder while themselves making only limited engagement so as to avoid possibilities of interference with the formation of an effective end seal between the stopper and shoulder. Since the seal occurs at the end of the stopper, contact between the fluid contents of the container and the elastomeric material of the stopper is more limited than in prior constructions, a factor that may be of some significance depending in part on the nature of the contents and the composition of the stopper.
Other important advantages, objects, and features of the invention will become apparent from the specification and drawings.
DRAWINGS
FIG. 1 is a side elevational view of a medical solution container embodying the invention.
FIG. 2 is a perspective view of the container showing the port assemblies thereof.
FIG. 3 is an enlarged exploded perspective view illustrating the components of the outlet port assembly.
FIG. 4 is a further enlarged longitudinal sectional view of the outlet port assembly.
FIG. 5 is an elevational view showing the outlet port assembly after the tear-off cap has been removed therefrom, and further illustrating, in broken lines, the step of peeling away the elastomeric sealing disc.
FIG. 6 is a fragmentary view of the longitudinal outline of the sealing disc illustrating the dimensional relationships of structural features thereof.
FIGS. 7-10 depict successive steps in the method of molding the outlet port.
FIG. 11 is an exploded perspective view illustrating components of the inlet port assembly.
FIG. 12 is an enlarged perspective view of the neck and stopper elements of the inlet port assembly.
FIG. 13 is a longitudinal sectional view showing the cooperative relationship between the inlet port neck and the piercable stopper.
DETAILED DESCRIPTION
Referring to FIGS. 1 and 2 of the drawings, the numeral 10 generally designates a medical solution container in the form of a collapsible bag or pouch 11 and a molded header 12 formed of thermoplastic material. Any suitable thermoplastic material or materials may be used that have the desired properties of flexibility, durability, autoclavability, and inertness. Effective results have been obtained with polyolefins, particularly with propylene-ethylene copolymers.
In the embodiment illustrated, bag 11 is composed essentially of two sheets or films of thermoplastic material heat sealed to each other along their bottom and side marginal areas 13 and 14, respectively, and heat sealed to header 12 along their top marginal areas 15. The bottom end of the bag is provided with an opening 16 to facilitate suspension of the container from the hook of a conventional IV stand. A pair of port assemblies 17 and 18 project from header 12 for the introduction and removal of fluids from the container.
Outlet port assembly 17 may also be referred to as a set port because it is intended to be used to couple the container 10 to a conventional administration set (not shown). As is well known, such a set includes a hollow spike that would be inserted into the neck of the outlet port after the tear-off cap and sealing disc are removed. Such a spike is frictionally retained by the neck so that when the container 10 is inverted and suspended, the fluid contents may be withdrawn therefrom and administered intravenously to a patient at predetermined rates. The three essential components of the outlet port assembly 17 are depicted most clearly in FIGS. 3 and 4 and consist of an outlet port neck 19, a sealing disc 20, and a tear-off cap 21.
The tubular neck 19 is formed integrally with header 12 and includes a distal wall portion 22 with an enlarged cylindrical bore 23 and a proximal wall portion 24 defining a reduced coaxial cylindrical bore 25. A tapered annular collar 26 is disposed within the neck and is formed integrally therewith, the collar extending distally from the proximal wall portion 25 into the enlarged bore 23. It will be observed from FIGS. 4 and 10 that the collar 26 has an inner surface 26a merging proximally with the surface of the reduced cylindrical bore 25, and also has an outer surface 26b spaced inwardly from the surface of enlarged cylindrical bore 23. Both the inner surface 26a and the outer surface 26b slope inwardly and distally, terminating in rounded end surfaces 26c that define an opening 27 at the collar's distal end that has a smaller diameter than that of reduced cylindrical bore 25. Consequently, an administration set spike (not shown) having an outside diameter smaller than bore 25 but larger than opening 27 will sealingly engage collar 26 to cause limited expansion of the resilient collar, and will be retained at least in part by the tensioning of the collar about the spike.
The angle of taper of the collar's inner surface 26a is shown to be approximately 10° measured from the axis of the neck, although a greater or smaller angle may be provided depending in part on other factors such as the relative length of the collar. In general, inner surface 26a would ordinarily have a slope within the range of about 5° to 15°. Of particular significance, however, is the angular differential α between inner surface 26a and outer surface 26b. The outer surface should have a greater acute angle of slope, the differential α between the angles of slope of the inner and outer surfaces falling within the general range of 3° to 10°. In the preferred embodiment depicted in the drawings, the differential α is approximately 5°.
While the angular differential is believed advantageous because it promotes a more effective flexing, wiping, and sealing action of the collar against the outer surface of the spike, it is particularly important because it greatly simplifies the molding of the neck 19 and integral header 12. FIGS. 7-9 depict in somewhat schematic form the sequence of molding steps. Four mold sections 28-31 are shown, the latter being in the form of a pin that is retracted in the direction of arrow 31a after sections 28, 29 and 30 have separated and the part 19 is to be stripped from the pin. Since the opening 27 at the reduced end of the collar is smaller than bore 25, separation of the part 19 and pin 31 will necessarily cause enlargement or outward flexing of the wall of the collar. Such outward flexing is illustrated in FIG. 8 and is accommodated without interference from the core pin only because of the angular differential α which provides progressively increasing clearance for such flexure as the core pin separates from the neck. Once separation is complete, the flexible collar returns to its original molded configuration (FIG. 9). The collar construction, and specifically the angular differential between the inner and outer surfaces 26a and 26b of the collar 26, therefore permit a molding operation utilizing the advantages of core pin separation as shown while, at the same time, providing an outlet port neck having a reduced opening 27 for insuring effective sealing engagement with an administration set spike when the container is used.
The tubular neck 19 includes a pierceable-diaphragm 24a formed integrally with proximal wall portion 24 and extending across the reduced cylindrical bore 25. It will be observed that the portion 25a of the bore below (on the proximal side of) diaphragm 24a has a diameter substantially larger than the portion of the bore immediately above (distal to) that diaphragm. As a spike pierces diaphragm 24a, the material of the diaphragm tends to fold or roll downwardly and outwardly, and such displaced material is accommodated in the space afforded by the greater diameter of bore portion 25a. The extent of relief provided will depend on the diameter of the neck and the thickness of diaphragm 24a; however, the relief for any given construction should be just enough to accommodate the displaced material of the diaphragm while at the same time limiting the extent of lateral displacement, and bracing the displaced material of the diaphragm, so that a snug frictional seal is formed about the spike and the displaced material of the pierced diaphragm. Thus, in use of the container, two sealing areas are formed to prevent leakage and secure the spike in place: one between the spike and the stretched collar 26 at opening 27, and the other between the spike and the annulus of displaced diaphragm material within bore portion 25a.
The tubular neck 19 terminates at its distal end in a planar annular end surface 32. As revealed in FIGS. 3-5, that end surface is engaged by one of the faces 33 of resilient sealing disc 20. The opposite face 34 of the disc is engaged by tear-off cap 21. The cap itself is entirely conventional, may be formed of aluminum or any other relatively soft metallic or polymeric material, has its annular edge 21a swaged inwardly to secure it to neck 19 with the sealing disc 20 in a slightly compressed condition as shown in FIG. 4 (the cap as shown in FIG. 3 is un-swaged as it would appear prior to assembly of the parts), and has a disc-shaped central section 21b that is partially cut free from the cap and may be pried upwardly by a user and then pulled outwardly to tear the cylindrical wall portion of the cap and thereby cause separation of the cap from the remaining elements.
Sealing disc 20 has a generally cylindrical side surface 35 with an integral annular rib 36 projecting outwardly and circumferentially therefrom. As illustrated in FIGS. 5 and 6, the rib is spaced equal distances x from each of the faces 33 and 34. In an undeformed state, the rib has a diameter appreciably larger than the outside diameter of neck 19 adjacent surface 32, and sufficiently larger than the inside diameter of the cap to cause deformation of the rib when the sealing disc is disposed within the cap (FIG. 4). In addition, the rib, which preferably has a rounded periphery when viewed in elevation, has a radial dimension y less than the distance x between the rib and each of the faces 33, 34, and has an axial dimension z within the general range of 15 to 30% of the total thickness of the disc (2x plus z). In the illustrated embodiment, the axial distance z is approximately 18 to 20% of the disc's total thickness.
Such a construction yields a number of important advantages. The deformation of the rib when the disc is inserted into cap 21 causes the rib to function as a centering and retaining means tending to hold the disc in place within the cap; however, because of the relationships described, rib 36 is incapable of flexing downwardly (proximally) a distance sufficient to contact the end surface 32 of the neck 19 and possibly interfere with the formation of an effective seal between surface 32 and planar face 33 of the disc. Following removal of the tear-off cap, disc 20 may tend to cling or adhere to surface 32, as illustrated in FIG. 5. In that event, a user may easily lift the disc free from surface 32 by prying a portion of rib 36 upwardly (distally) as shown in broken lines in FIG. 5. Such prying action, using the index finger and lifting a portion of the rib away from neck 19, is readily accomplished without contacting end surface 32 and the surface of enlarged bore 23 because the rib is spaced a substantial distance from surface 32 and has a diameter greater than neck 19 (FIG. 5). Since the rib is equidistant from planar faces 33 and 34, the sealing disc 20 may be inserted into cap 21 in either of two ways (i.e., with faces 33 and 34 being reversible in position), thereby facilitating production assembly of the container.
In the preferred embodiment of the invention, sealing disc 20 is formed of natural rubber; however, any other relatively soft elastomeric material may be used that would be effective in providing a resilient seal in the manner described above. Also, while the drawings illustrate what is regarded as a particularly effective form of disc construction in which the rib extends continuously about the disc, it is believed that at least some of the functions and results described above might be achieved if the rib were discontinuous, that is, interrupted at one or more circumferential locations.
The inlet port assembly 18 is shown in detail in FIGS. 11-13 and includes tubular neck 39 formed integrally with header 12, stopper 40, and retention cap 41. Like cap 21, retention cap 41 may be formed of aluminum and is swaged along its periphery 41a to secure it to neck 39; however, cap 41 differs by being non-removable and having a central opening 42 in its top surface so that an axial portion of stopper 40 is exposed for needle insertion. To avoid contamination of the surface of the stopper exposed by opening 42, a suitable cover 43 formed of plastic or other material may be removably affixed to the cap 41. Since the cover and its method of attachment to the cap form no part of this invention, and since various means might be used to provide such attachment, all within the scope of the prior art, the cap and its mounting will not be described in further detail herein.
Neck 39 has a bore 44 extending therethrough. Within the bore is an annular projection 45 formed integrally with the wall of the neck and defining a planar annular upper (distal) surface 46. In the portion of bore 44 above (distal to) shoulder 46 are a plurality of longitudinally-extending circumferentially-spaced ribs 47. It will be observed from FIGS. 12 and 13 that the ribs not only extend distally with respect to shoulder 46 but are also disposed outwardly or laterally beyond that shoulder.
The stopper 40 is of inverted hat-shaped configuration with a head portion 48 and an integral, coaxial body portion 49. The head portion has a diameter generally the same as the outside diameter of the distal end of neck 39. The cylindrical body portion 49 has a diameter less than the diametric spacing between ribs 47, at least when the stopper is in an undeformed or uncompressed state. However, the length of the cylindrical body portion when the stopper is undeformed or uncompressed is slightly greater than the distance between the end surface 50 of the neck and shoulder 46. The free end of body portion 49 is provided with an annular end surface 51. In the embodiment illustrated, body portion 49 has a beveled edge or surface 52 circumscribing annular surface 51, and the central area of body portion 49 is recessed at 53 (FIG. 12).
The result is a construction in which effective sealing occurs in two annular zones. A proximal seal occurs between the annular end surface 51 of the stopper and shoulder 46 of the neck, and a distal seal occurs between the end surface 50 of the neck and the undersurface (or annular proximal surface) 48a of head 48. The proximal seal is of particular significance because it prevents the invasion of the liquid contents of the container into the zone extending about the cylindrical surface of body 49. Direct contact between the fluid and the stopper is therefore limited in area to the concave surface of recess 53. The effectiveness of the proximal seal is enhanced by a slightly greater length of body portion 49 (in an undeformed state) relative to the distance between shoulder 46 and surface 50, and by the further fact that a slight clearance is provided between body portion 49 and ribs 47, at least before axial compressive forces are applied to the stopper by cap 41. During an assembly operation, the cap 40 may therefore be fitted into place without encountering resistance from ribs 47 that might interfere with the formation of an effective proximal seal between end surface 51 of the stopper and annular shoulder 46. However, if for any reason the proximal seal should fail, the distal seal between head surface 48a and neck surface 50 will serve as a back-up to prevent leakage. Conversely, the distal seal performs a major function in preventing the entry of contaminants into the container; in that regard, the proximal seal serves a secondary or back-up function.
The inlet port assembly is used whenever an additive is to be injected into and mixed with the pre-packaged contents of the container. For that purpose, container 10 is only partially filled with parenteral fluid at the time of manufacture. FIG. 1 illustrates a typical level 60 for the contents of a container designed to hold 100 milliliters of sterile fluid for injection. If medication is to be administered intravenously to the patient, the medicament may be injected into the container through the inlet port, mixed with the diluent already packaged in the container, and administered to the patient through an administration set coupled to outlet port 17. When injecting the medicament into the container, cover 43 is removed and the needle of the syringe (not shown) is simply inserted through cap opening 42 and through resilient self-sealing stopper 40. The stopper may be formed of any suitable elastomeric material; in the embodiment illustrated, a soft natural rubber is utilized for stopper 40 as well as sealing disc 20.
While in the foregoing I have disclosed embodiments of the invention in considerable detail for purposes of illustration, it will be understood by those skilled in the art that many of these details may be varied without departing from the spirit and scope of the invention. | Improved port and closure constructions are disclosed for medical solution containers, particularly collapsible containers intended for storing and administering parenteral solutions. An outlet port includes a tubular neck with an elastomeric sealing disc held against the distal end of the neck by a tear-off cap, the disc having planar surfaces and a circumferential rib spaced from each of those surfaces for sealingly engaging the inside of the cap. Within the outlet port is an annular collar that slopes and tapers distally inwardly for engaging the spike of an administration set. An inlet port is also provided, such inlet port having a neck with an internal annular distally-facing shoulder and a plurality of longitudinal internal ribs located distal to the shoulder. The ribs are useful for guiding a stopper into sealing engagement with the shoulder without interfering with the seal as so formed. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to a structural member and, in particular, to a structural member that is capable of being interlocked with a member of similar construction to form a right angle section or a rectangular column.
As is well known in the art, preformed structural shapes have been used for some time in the building industry to carry out a wide variety of tasks. For the most part, however, these preformed members are generally designed to perform one specific function, are usually complex in construction and are relatively difficult to assemble. Furthermore, once brought into assembly, the component parts of the unit usually do not provide sufficient temporary holding power to allow the assemblage to be quickly and safely erected.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to improve structural members used in the construction of buildings or the like.
A further object of the invention is to provide a structural member that is capable of being joined to similar members to provide right angle sections or rectangular columns.
Another object of the present invention is to simplify the form of interlocking structural members used to create building sections.
A still further object of the present invention is to provide a structural member having a rectangular flange that can be simply snapped into place with another similar structure to provide an assembly having sufficient temporary holding power to allow the assemblage to be rapidly and safely erected.
These and other objects of the present invention are attained by means of a structural member including an elongated web having open ended flanges projecting laterally to the same side of the web from each of its two longitudinal edges and being opened to the opposite side of the web. Each flange is rectangular in form and includes a bottom wall or base and two parallel side walls. The inner side wall connects the base to the web while the outer side wall contains a lip that lies in the plane of the web and which is turned inwardly toward the web to restrict the flange opening. The length of the lip is controlled to allow two flanges to be snapped together with sufficient holding power to securely hold the two cojoined members together and thus enable the assemblage to be easily handled and erected at the building site.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of these and further objects of the present invention reference is had to the following detailed description of the invention which is to be read in conjunction with the following drawings, wherein:
FIG. 1 is a perspective view showing four structural members embodying the teachings of the present invention brought together to form a building column; and
FIGS. 2 and 3 illustrate the steps involved in snapping the end flanges of two members shown in FIG. 1 together to form a right angle section.
DESCRIPTION OF THE INVENTION
As illustrated in FIG. 1, there is shown a building column referenced 10 that is formed by bringing together four structural members, generally designated 11, which embody the teachings of the present invention. Each of the structural members includes an elongated web 12 having two end flanges 13 projecting laterally to one side of the web. The flanges, which are of similar construction, are generally rectangular in form and are open to the opposite side of the web. Preferably the structural member is roll formed from a single sheet of material that possesses relatively high strength but which is resilient enough to permit the member to deform sufficiently so that it can be interlocked or snapped together with similar members in a manner which shall be explained in greater detail below.
Each rectangular flange includes a bottom wall or base 15 that is positioned in parallel alignment with the web. The base is connected to the longitudinal edge of the web by means of an inner side wall 17 that is normal to the plane of the web. A second outer side wall 18 depends upwardly from the outer edge of the base. The outer side wall is positioned in parallel alignment with the inner side wall and teminates in the plane of the web. A lip 20 depends inwardly from the distal end of the outer wall and is located in coplanar relationship with the web. In practice, the lip extends inwardly into the opening 23 of the flange to restrict the size of the opening.
As best seen in reference to FIGS. 2 and 3, each flange is constructed so that the inside width of the flange between the two side walls 17 and 18 is held to a given dimension "D" that is substantially equal to or slightly greater than the overall depth of the flange as measured over the base 15 and the extended lip 20. As a result of this construction, a flange carried by one member can be conveniently received within the flange of a second member with the walls of the two cojoined flanges being in contiguous relationship as illustrated in FIG. 3.
To join the flange of one member with that of another, the lip of the first flange is inserted obliquely into the restricted opening of the second flange as shown in FIG. 2 and the members rotated as indicated by the arrow to seat one flange within the other. For purposes of explanation, the component parts of the receiving flange shown in FIGS. 2 and 3 shall be designated with the letter "a" while those of the accepted flange received therein shall be designated with the letter "b".
The overall length "h" of the turned lips 20a or 20b is held to about one third of the inside width "D" of the flange. By holding this width to lip length relationship to about that noted, the lip 20b will become seated between the base and the outer side wall of the receiving flange 13a as the flanges are turned. This in turn will place the outside corner 25b of the accepted flange into interferring contact with the inside of wall 17a. Further turning of the flange of the accepted member will cause the two resilient structural members to deform sufficiently to permit the lip 20b to move down the inner surface of the wall 18a.
Because of the geometry of the system, the biasing pressure exerted by the deformed member is greatest at the time that the lip 20b starts to move down the wall and becomes progressively less as the lip swings into parallel alignment with the wall 18a of the receiving flange. As a result of this decreasing biasing pressure, the side wall 18b of the accepted flange is pulled rapidly into seating contact against the base of the receiving flange as shown in FIG. 3 and the accepted flange is brought into contiguous alignment within the receiving flange.
As can be seen because of the predetermined shape of the flange, the elongated webs of the two cojoined members are supported at a right angle when the two members are brought together. It should be further noted that the lip provided to each interlocked flange also serves to hold the interlocked members in alignment as well as preventing them from becoming separated in assembly.
Referring once again to FIG. 1, there is shown a building column of rectangular form that is created through interlocking four members together. To form this column, three structural members are snapped together at their flanges as described above to establish a three sided section. The last or final member of the assembly is then simply joined to the section by sliding the two end flanges of the last member into the two unfilled flanges remaining in the section. This locks the four members securely together with sufficient holding power to permit the column to be quickly and safely erected at the building site.
While this invention has been described in reference to the disclosure herein set forth, it is not necessarily limited to this particular embodiment and this application is intended to cover any modifications or changes as may come within the scope of the present invention. | A structural member having similar flanges mounted on either end. The flanges of individual members can be interlocked to form either right angle sections or rectangular columns. | 4 |
FIELD OF THE INVENTION
[0001] This invention relates to systems for communicating alert messages to one or more recipients by way of a wireless communicating device and more particularly to such systems wherein a push button for the purpose of initiating the alert message is separate from the communicating device.
BACKGROUND
[0002] The unfortunate and often fatal surprise attack on people of all ages, but in particular young females has grown into a major concern in urban areas. Young women are often advised to stay away from certain communities and to never travel alone especially at night. Frequently attacks on young people are instigated by one or more perpetrators using surprise tactics. This means that the victim is often attacked from behind leaving very little time or opportunity to call for help.
[0003] The ubiquitous cell phone is often considered to provide some safety margin but if the attack is sudden and unexpected there is just no time to access the cell phone and then initiate a call for help. Further, if a call for help is made on the cell phone an attacker, determined to go forward with the attack, may take immediate and harmful action sooner rather than later. Thus what might otherwise have been a scare turns into a nightmare.
[0004] There is, therefore, a need for an alerting system by which the victim can initiate a call for help without the attacker knowing that the call was made. Accordingly, the problem addressed by this invention is to make a panic button system that allows a user to instantly and easily make a call to the police and/or others, so that they could know where the user is, and be able to send help. This would increase the users chances of survival if ever they get attacked.
[0005] The Inventors got the idea for this invention when a young woman in the Inventors' community went missing. They were amazed that there was no way to get help other than by calling 911, which in most cases of abduction or attack the victim doesn't have the time to do. The problem to be solved is to find an alternative mechanism that is simple to use, easy and reliable to activate, and cost effective enough to allow mass wide scale commercial adoption including by youth.
[0006] A specific system implemented to solve this problem is called “Jennifer Alert”, in memory of the victim, though other variations of the concept are possible.
PRIOR ART
[0007] The following discussion identifies the prior art of which the Inventors are aware. A description of each reference is provided followed by a brief explanation as to how the present invention distinguishes the reference. All the references deal with personal alert systems generated from a mobile device. None extend this system by decoupling the alert trigger button from the mobile device, as in the present invention, such that it can be easily hidden and activated without having to handle a mobile phone. The system of the present invention is also made cost effective, by using existing devices and systems. It is also unique with the ability to send continuous tracking information to multiple users.
[0008] U.S. Pat. No. 7,046,140—Method and System for Alerting a Person to a Situation.
[0000] A method of alerting a person to a situation is disclosed. An alert signal is received from a mobile communication device in signal communication with a wireless communication system and an alert system. In response to the alert signal, a database of an alert service is accessed for information relating to the subscriber of the mobile communication device and for information relating to a contact list associated with the subscriber. Information is obtained from the wireless communication system relating to the location of the subscriber, and a communication is made to a member of the subscriber's contact list providing information relating to the subscriber and the situation.
[0009] Differences: The main difference is that the above patent relates to a system for sending alerts from a mobile device only. But this would still require the user to pull out the mobile device and activate the alert signal. Jennifer Alert is better because of a wearable panic button that is easy to activate remotely from the cell phone. The cell phone can still be in the user's purse or pocket, saving valuable time and the user can do it without the attacker realizing that a call for help has been made. Also, this system uses GPS in the mobile device, giving an accurate and continuously update of location, not just the location where the button was hit. And, keeping the GPS in the cell phone instead of the button keeps the button small.
[0010] U.S. Pat. No. 7,058,409—Personal Safety Net
[0000] A personal safety net includes a mobile terminal, a server including a memory to store data, and a communications network to transmit data between the mobile terminal and the server. The mobile terminal may include an image data generator, such as a camera, to generate image data and a voice data generator, such as a microphone, to generate voice data. The mobile terminal further includes an output device to transmit the data to the communications network. The server stores, in its memory, the data transmitted from the output device of the mobile terminal to the network operator server via the communications network. A location data generator, located within either the mobile terminal or the communications network, for example, may be included to generate location data as to the location of the mobile terminal, the location data also being stored in the server.
[0011] Differences: The main difference is that this is a system that doesn't use Bluetooth remote activation of the alert system. Jennifer Alert is better because Bluetooth wireless technology makes it is easy to activate remotely from the cellphone. Also, the system of the present invention uses GPS in the mobile device, giving an accurate and continuously updated location, not just the location where the button was hit. And, keeping the GPS in the cellphone instead of the button keeps the alert button small.
[0012] U.S. Pat. No. 6,784,833—Personal Surveillance System with Locating Capabilities
[0000] A personal surveillance system configured to be worn by an individual includes a communication system configured to record communication files, a locating system configured to determine a location of the personal surveillance system, and a transmitter configured to send the communication files and the location of the personal surveillance system to a remote monitoring station. The locating system includes a satellite system interface configured to determine the location of the personal surveillance system and an alternate positioning system configured to determine the location of the personal surveillance system in at least one situation where the satellite system interface cannot determine the location of the personal surveillance system.
[0013] The main difference is that the system of the present invention sends a signal to the police, or anyone else on the contact list. Plus, Bluetooth sends the signal to a cell phone or blackberry instead of the button or the mobile device doing everything. This makes it better because it allows the button to be smaller, allowing it to be easier to wear, and less easy for the attacker to find. It would also benefit by more efficient transmission than satellite based system (power, battery consumption, cost, size).
[0014] U.S. Pat. No. 7,016,478—911 Emergency Voice/Data Telecommunication Network
[0000] Various embodiments of a 911 emergency voice/data telecommunication network are provided. In one embodiment, the telecommunication network includes: a caller device originating a 911 emergency call having a voice portion, and a data portion, a local service interface, a public voice network, a public data network, and an ESN, wherein the ESN determines the appropriate emergency service organization to receive the 911 emergency call and dispatches the voice portion and data portion thereto. In another embodiment, the telecommunication network includes: a BS, MSC, MPC, and PDE. In another embodiment, the 911 emergency call includes a 911 origination service option. In another aspect of the invention, a method for communicating a mobile-originated 911 emergency call to an appropriate PSAP is provided. In still another aspect of the invention, a caller device for originating the 911 emergency call is provided. The caller device includes: a microphone, a camera, and a 911 button.
[0015] The present solution is better because it is activated remotely from the mobile device, can be hidden, and can send it to more than 1 person, not just the police, and it sends an e-mail or text messages, saving time and effort.
SUMMARY OF THE INVENTION
[0016] There exists tracking devices so parents will know where to find their children, but most teenagers don't want their parents to track their every move. The proposed system is only activated by the user when required, and can notify both parents and authorities simultaneously. There are mobile phones and other systems with panic button 911 capabilities, but these still require the phone to be manually activated and spoken into. These also can only notify one party, not multiple.
[0017] The invention allows an individual to alert authorities and members of a contact list of a panic/alert situation. The novelty of this invention is it is activated by a small sized panic button, that can easily be disguised, and which communicates, in a preferred embodiment, wirelessly to a nearby personal communication device which in turn uses the existing mobile or fixed communications network to transmits the panic information, including location, on an ongoing basis.
[0018] Therefore in accordance with a first aspect of the present invention there is provided a system for sending an emergency alerting message to one or more recipients comprising: a manually operated alerting device; and a wireless communications device adapted to transmit an alert message received from the alerting device, the alert message being selectively transmitted to the one or more recipients over a communications network.
[0019] In accordance with a second aspect of the invention there is provided a method of sending an emergency alert message by a system user to one or more recipients over a communications network comprising: initiating an alert message by manually activating a pushbutton on an alert device carried by the system user, the alert device implementing a transmission protocol; and receiving the alert message by a communications device in proximity to the user, the communications device being programmed to transmit the alert message to the one or more recipients over a wireless communications network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The invention will now be described in greater detail with reference to the attached drawings wherein:
[0021] FIG. 1 is a high level illustration of alerting solution provided by the invention;
[0022] FIG. 2 illustrates the overall concept of the invention including functional blocks, information flows and participating entities;
[0023] FIG. 3 illustrates the overall operation of the invention; and
[0024] FIG. 4 shows the design concept of the alert button.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 shows, at a high level, the basic elements of the system according to the present invention. A system user 1 carries, wears or otherwise has easy access to, an alert device (not shown). The alert device has the capability of sending an alert message when a push button (alert button) on the alert device is activated. In a preferred embodiment the Bluetooth communications protocol is used to send a wireless message to the Blackberry 2 . It is within the scope of the invention for the alert device to be hard wired to the Blackberry 2 for use in transmitting the alert message. It is also within the scope of the invention to use a cell phone, computer with wireless access, or other PDA in place of the Blackberry. The Blackberry or equivalent relays the alert message via wireless telephony or via email through the internet 3 . The alert message, including the name of the system user and preferably the GPS coordinates and real time, is then delivered to one or more pre-designated recipients such as the police, parents, friends, etc.
[0026] The generic embodiment of the invention is captured in FIG. 2 . As indicated above it captures the overall concept including functional blocks, information flows, and the participating entities. The key participating entities within the operational framework are: user, Activation (Alert) Device (panic button), communications device, and communications network. Each functional block and the participating key entities are described in further details below:
[0000] a) User: A mobile or fixed service subscriber regardless of its physical access mechanisms. This subscriber will have an account or access connectivity permission using any fixed, mobile or cellular technology communications devices supporting a data interface including CDMA, GSM/GPRS, UMTS, Wifi (802.11×), WiMax etc. (A typical user is a cellphone subscriber.)
b) Destinations: The parties to be contacted with the alert message. The entries to call the appropriate destination number/address can be pre-configured in the communications device by the individual user, and can consist of one or many data interface destinations (email, SMS numbers) or voice call destinations (911, police, home phone etc. . . .)
[0027] The following describes the key functional blocks:
[0000] c) Activation Device: Any device used as a trigger to activate the alert system. The activation device will act as the Panic button, consisting of an activation switch and a mechanism to notify the host communications device of activation via any form of connection, typically with a short range wireless technology such as Bluetooth (IEEE 802.15.1). It can be connected with any alternative short-range technique not excluding wired methods. The activation device can be designed to be concealable, wearable or otherwise readily accessible for activation in the event of an emergency (such as being attacked). The portable, concealable aspects of the activation device makes it important for the activation device to be distinct and separated from the communications device—since the solution is intended for situations where it is not possible or impractical for the user to directly use the communications device.
d) Communications Device: any data enabled personal communications device including but not restricted to: cellular phones, laptop with wireless access, or Personal Digital Assistant (PDA). Use of such devices in conjunction with internal or adjunct device or mechanism for determining location (such as a GPS receiver) for positioning information is an optional but important aspect of the system. The communications device generates alert messages into the communications network using pre-configured message contents, combined with current GPS location. The messages can be sent as data messages (email, SMS . . . ) or voice message (using pre-recorded or text-to voice features)
e) Communications Network: The communication network through which the device can access the destination party, such as mobile cellular, wifi wireless, internet or PSTN phone system. This system infrastructure may have the ability to determine approximate device location in the event that the communication device is employed without providing location (e.g. GPS) information.
[0028] Example Specific Implementation:
[0000] One embodiment of the invention is captured in FIG. 3 . It captures the overall operation framework including functional blocks, information flows, and the participating entities. Each functional block and the participating entities are described in further details below:
Key Entities
[0029] a) User: A mobile service subscriber on any mobile (e.g. cellular) network. Such subscriber will be using any mobile/cellular technology supporting a data interface including CDMA, GSM/GPRS, UMTS, Wifi (802.11x), WiMax etc.
b) Destinations: The parties to be contacted with the alert message. These entries can be pre-configured in the device by individual users, and can consist of data interface destinations (email, SMS numbers) or voice call destinations (911, police, home phone etc. . . .)
Key Functional Blocks:
[0030] c) Activation Device: The Panic button design provides the key attributes of small size, low power, wearable on or inside of clothing or accessories such that it will be immediately accessible but inconspicuous. The Panic button is a small button disguised as a wearable pin, jewellery accessory etc., with integrated trigger protection that makes it easy to activate if required but protected from being accidentally activated. When activated it uses Bluetooth short range wireless communication to the mobile communications device.
[0031] The device includes the following aspects:
[0000] 1. Trigger Protection: to prevent inadvertent activation, a mechanical or electrical mechanism can be employed to provide positive but rapid and simple activation.
2. Activation Detection: a “switch” function that detects initiation. This can include the capability to recognize, allow and debounce multiple trigger initiations likely to occur in a true panic situation into one “triggered” indication to the transceiver. Multiple activations can be used as a technique to indicate varying levels of alert severity by sending multiple of differing indications to the communications device.
3. Transceiver: a wireless interface connecting the activation device to the host communications device via a short range wireless technology such as Bluetooth (IEEE 802.15.1). It can also be connected with any alternative short-range technique including wired methods, or can even be integrated into the communications device itself.
4. Battery: remote wireless capability requires integrated battery for powering the transceiver and any other electronics used.
d) Communications Device: The Mobile device can be a Blackberry or other Bluetooth capable cellphone with an integrated GPS receiver. The communications device generates alert messages into the communications network using pre-configured message contents, combined with current GPS location. The messages can be sent as data messages or voice message (using pre-recorded or text-to voice features).
[0032] The capability of the communications device include:
[0000] 1. Bluetooth transceiver: Bluetooth or similar short range connection system interfaces to the transceiver in the activation device. To ensure secure and private operation, a particular Bluetooth device is authenticated by the host configuration to ensure only that device will connect to the alert system. This requires pre-configuration of the Bluetooth systems. When an activation signal is received, the transceiver notifies to the Alert Application software of the event.
2. GPS Receiver: The GPS receiver can be included as an integrated function of the mobile communications device. Alternatively, an external adjunct GPS receiver can be connected to the communications device for positioning information, or the system can be implemented with no location information provided from the mobile communications device. Location information is vital to indicated to the communicated authorities the location of the attack/event. Subsequent retransmission of location at intervals allows tracking of the person and device in the event of an abduction or other reason for change of location. This is a unique aspect of the system compared to existing alert solutions.
3. Alert Application Software: This is a software application running in the device that receives indication of an alert trigger, collects the current location information, and formulates alert messages to be sent over the communications network. The destinations and alert message contents are pre-provisioned by the user. In the event of activation, messages are sent to the network at pre-programmed intervals until the alert state is cancelled by the user via the device user interface. Text or graphical notification can also be provided on the screen of the device for user notification of the alert status.
4. Cellular transceiver: the normal device interface is used to send the alert messages.
5. User Interface: Visual display screen and user input (keyboard etc) are used to interface between the user and the Alert application software. The use of the device keyboard and display allows the system to be enabled, disabled, and an activated alter to be cleared. These commands can be protected behind a security password to prevent unauthorized control of the system.
6. Battery: for mobile device operation.
[0033] e) Communications Network: The communication network through which the device can access the fixed network—internet or phone system. This system infrastructure can have the ability to determine approximate device location in the event that the system is employed without GPS information.
[0034] Other Functional Aspects of the System:
[0000] Device Configuration: The communication device is configured with information which is stored user configurable message content to be sent when the alert is triggered, such as an email containing “PANIC: this is Michelle Morin, home phone # xxx-xxxx. This is an emergency—please send help”. The destinations to which the message is to be sent are also configurable. The message type(s) can also be configured—email, SMS, voice etc., and any desired message to be displayed on the device user interface can be configured.
Alert Response: An optional capability is for the contacted destination parties to respond to the communications device to acknowledge receipt or other response.
[0035] This following describes the method of using the invention in the above embodiment. The embodiment of the invention is a mobile, wearable panic button. The system has been called “Jennifer Alert” by the inventors, in memoriam of a teenager by the name of Jennifer Teague who was abducted and murdered in Ottawa Ontario in 2005. She was in possession of a cellphone, but did not have time to use it. Hence the idea is to have a simple way that messages can be sent from cellphone devices in the person's possession, such as in a pocket, purse or packsack, but have the activation button easily reachable and disguised from the attacker such that activation of it can be done discretely without being noticed. The messages sent would contain a panic message, the time, and the location of the unit at the time of transmission by sending the GPS coordinates. These messages can be sent repeatedly at a predetermined interval, which will allow a person being moved to be tracked.
[0036] This system can be operated as a branded service feature from a mobile network operator, or may operate over a generic mobile service from a user configurable mobile device operating without the knowledge or explicit participation of the mobile operator.
[0037] The user needs to program the message contents and destinations into the device to prepare the system for operation. The mobile device can be provided with default messages such as “Panic—send help to this location”, and default destinations such as a local police number or 911 for voice messages. Multiple destinations can be supported, allowing a one to many broadcast for help.
[0038] The mobile device must have a mechanism to connect to the panic button over a short range. The typical example cited is using Bluetooth due to its low cost, low power, and small size of transmitter that can be embedded in the wearable panic button. Both the panic button and the mobile device would need to be powered on and enabled via the device user interface for the system to be armed.
[0039] The Panic Button is intended to be placed at an easy to reach location. This can be on clothing, in a pocket, be integrated into another Bluetooth device such as a headset, or even be enabled as a button on the mobile device itself. It can be disguised to be discrete so as not to draw attention before, during, or after activation.
[0040] If a panic event occurs, the user will remove the trigger protection and activate the button. This will send a signal to the mobile device, which will receive the activation and initiate “Jennifer Alert” software in the device. This software will interface to an embedded or external GPS receiver (if present and active) to gather current location information. This information is embedded into the preconfigured the Panic message that then gets transmitted to the configured destinations over the mobile network infrastructure.
[0041] The messages will continue to be sent for a configurable number of times or until the Jennifer Alert program in the mobile device is disabled or the Alert cleared. Enabling, disabling and clearing of triggered Alerts would be protected by an optional security password to prevent unauthorized control of the system. When activated, the Jennifer Alert system can also disable the device power-off button and other aspects of controlling the mobile device to prevent intentional or accidental disabling of the mobile device.
[0000] Responses to alert messages received can optionally be sent to the mobile device by the destination parties.
[0042] Appropriate response by the contacted authorities is now possible. Use of data messages such as SMS or email leaves a recorded log of the messages and times for subsequent analysis.
[0043] The following key advantages over existing solutions, as set out in Reference Table 1 below, quantifies advantages of the technologies described here:
[0000] 1) Standard mobile phones do not offer an effective level of protection during certain emergency situations, due to the need to dial a destination number or address and speak or type into the device, both of which may not be possible. In some cases the user may not even know their current location. This system allows simple activation, discrete operation, automatic location transmission, and many-to-one alert messages that can improve the response time for assistance. Unlike a standard 911 call, this system will continue to transmit messages with accurate and updated location information for as long as the system is activated. The system can be enabled using standard low cost commercially available Bluetooth, mobile device, and GPS technologies, thus enabling very cost effective implementation.
2) Personal panic systems employing the use of EPIRB satellite systems are physically very large, prohibitively expensive for wide scale personal use, and operate on tightly controlled and scarce RF spectrum. Activation can take up to several hours to be received by the satellite system, and will be dependent on atmospheric conditions such as storms. Activation (inadvertent or intentional) triggers response from the coast guard—hardly the proper authorities for a personal situation in a residential or rural environment.
3) Walkie-talkies are commonly used by parents for short range communications with their children within a local neighborhood range. However the operational range is extremely limited, subject to line of sight interference from building, trees, and hills, and still requires obvious voice activation and for communication of location. A parent can now provide a mobile device to the child, confident that the panic system will work in the very wide coverage of the cellular system.
4) There are tracking devices (e.g. the Trimble TrimTrac Personal Tracking device designed for automobile tracking systems) that enable parents will know where to find you at any time, but many users and parents don't wish a record to be kept to track their every move. This approach also requires a large, special purpose, and expensive device to be carried by the user. The Jennifer Alert system makes use of existing common personal communications devices.
5) Mobile Communications systems sometimes support the capability to use the mobile network device location information (based on cell location) to track movement of users. This enables tracking of all movements, not just at times selective by the user, and does not generate an Alert indication to authorities and parents that a panic event has occurred.
[0000]
TABLE 1
Characteristics of the system components by technology
Wifi
Walkie-
Cell
Bluetooth
Characteristics
(802.11)
Talkies
phone
EPIRBs
Blackberry
(Class 2)
Network Access
Rare
No
Good
Good
Good
Good
Programming
Easy
No
Hard
Hard
Medium
Hard (To
have the
device
use it)
Range
100 m
90 m
Anywhere
Unlimited
Anywhere
10 m
there is
there is
coverage
Data link
Cost
60$
40–100$
90–400$
500–1000$
50–500$
5–10$
Size
7.8 mL
220 mL
64 mL
2310 mL
73.5 mL
1.2 mL
(6.5 cm ×
(16 cm ×
(8 cm ×
(21 cm ×
(10.5 cm ×
(1.5 cm ×
4 cm × .3 cm)
5.5 cm × 2.5 cm)
4 cm × 2 cm)
11 cm × 10 cm)
7 cm × 1 cm)
3 cm × .28 cm)
Power
4 watts
2 watts
.125–.25
5 watts
Variable
4 dBm
watts
(similar to
(2.5 mW)
cell phones)
Other
+1 hour
response
time and
>1 mile
accuracy
Decision
No
No
No
No
Yes
No
[0044] As will be understood this invention's operation requires an activation device and a mobile phone, both operated on batteries which will require periodic changing or recharging. It is also to be noted that if the alert button is moved out of range of the mobile device the trigger cannot be activated.
[0045] Such concerns are addressed by the following:
[0000] The system can be designed to have the mobile device generate a message to the user via the user interface if it loses contact with the Bluetooth device, or if it senses the signal fading which could be an indication of power problems with the Bluetooth device. If the Bluetooth device moves out of range or the signal fails, a distinct message can be sent with the time and location that this occurred, but with a non-panic indication. This way if the button was taken out of range in a panic situation there will at least be a record of the time and location that this occurred.
[0046] The following provides a Blackberry Java Program for the Jennifer Alert system of the present invention.
[0000]
/*
* Jennifer.java
*
* © <your company here>, 2006–2007
* Confidential and proprietary.
*/
/**
* BasicMail.java
* Copyright (C) 2001–2005 Research In Motion Limited.
*/
package com.rim.samples.docs.basicmail;
import net.rim.blackberry.api.mail.*;
import net.rim.blackberry.api.mail.event.*;
import net.rim.device.api.ui.component.*;
import net.rim.device.api.ui.*;
import javax.microedition.location.*;
import net.rim.device.api.ui.container.*;
public class Jennifer extends UiApplication {
private Store store;
static void main (String args[ ])
{
Jennifer app = new Jennifer( );
app.enterEventDispatcher( );
}
Jennifer( )
{
pushScreen(new JenniferScreen( )); // move into instance vriable
}
private class JenniferScreen extends MainScreen
{
private LocationProvider _locationProvider;
private Location _location;
private int _interval = 5; // change this to change interval
int count = 0;
Font f;
Font[ ] fs;
JenniferScreen ( )
{
try {
_locationProvider=LocationProvider.getInstance(null);
_locationProvider.setLocationListener(new LocationListenerImpl(this),
_interval, 1, 1);
} catch(LocationException e) {e.printStackTrace( );
System.out.println(“LocationException”);
{ catch (IllegalArgumentException e) {
e.printStackTrace( );System.out.println(“IllegalArgumentException”);}
// Displaying line with font
f = Font.getDefault( );
f = f.derive(Font.EXTRA_BOLD);
Font.setDefaultFont(f);
fs = new Font[1];
fs[0] = f;
add (new RichTextField(“PANIC”, null, null, fs, 0));
// --------------------------
f = f.derive(Font.PLAIN);
Font.setDefaultFont(f);
}
public void showLocation (double lat, double lon) // this gets “called” which means run,
every “interval” ammount of seconds
{
deleteAll( );// clears screen
// Displaying line with font
f = Font.getDefault( );
f = f.derive(Font.EXTRA_BOLD);
Font.setDefaultFont(f);
fs = new Font[1];
fs[0] = f;
add (new RichTextField(“PANIC”, null, null, fs, 0));
f = Font.getDefault( );
f = f.Derive(Font.PLAIN);
Font.setDefaultFont(f);
// ------------------------- // this adds the text to screen
add (new LabelField(“Latitude” + lat));
add (new LabelField(“Longitude” + lon));
sendEmail(“michi.morin@sympatico.ca”, “SOS”, “Jennifer is in need of help!\n
Latitude: “ + lat + ”, Longitude: ” + lon);
count = count + 1;
add (new LabelField(“Number of e-mails sent ” + count));
}
public boolean onClose( );
{
if(_locationProvider != null)
{
_locationProvider.reset( );
_locationProvider.setLocationListener(null, −1, −1, −1);
}
sendEmail(“michi.morin@sympatico.ca”, “Test email” , “Jennifer exited Panic.”);
return super.onClose( );
}
private void sendEmail (String address, String subject, String message)
{
Store store = Session.getDefaultInstance( ).getStore( );
Folder[ ]folders = store.list(Folder.SENT);
Folder sentfolder = folder[0];
// Create message.
Message msg = new Message(sentfolder);
// Add TO Recipients.
Address toList[ ] = new Address[1];
try {
toList[0]=new Address(address, “Scott Toke”);
} catch(AddressException e) {
System.out.println(e.toString( ));
}
try {
msg.addRecipients(Message.RecipientType.TO, toList);
{ catch (MessagingException e) {
System.out.println(e.toString( ));
}
// Add the subject.
msg.setSubject(subject);
// Add the message body.
try {
msg.setContent(message);
} catch(MessagingException e) {
// Handle messaging exceptions.
{
// Send the message.
try {
Transport.send(msg);
} catch(MessagingEception e) {
System.out.println(e.getMessage( ));
}
System.out.println(“Email sent successfully.”);
}
}
private class LocationListenerImpl implements LocationListener
{
private JenniferScreen_screen;
LocationListenerImpl(JenniferScreen screen)
{
_screen = screen;
}
public void locationUpdated(LocationProvider provider, Location location) {
// add (new LabelField(“Latitude ”+
location.getQualifiedCoordinates( ).getLatitude( )));
_screen.showLocation(location.getQualifiedCoordinates( ).getLatitude( ),
location.getQualifiedCoordinates( ).getLatitude( ));
}
public void providerStateChanged(LocationProvider provider, int newState) {
}
}
}
[0047] While specific embodiments of the invention have been described and illustrated it will be apparent to one skilled in the art that numerous changes and/or variations can be made without departing from the basic concept. It is to be understood that such changes and/or variations, to the extent possible, will fall within the full scope of the invention as defined by the appended claims. | An emergency alerting system for permitting a user to secretly send a request for help to multiple parties is described. The system uses a small panic button which may be concealed on the user and which can be activated without an attacker knowing that a call for help has been initiated. The panic button communicates the call for help to a cell phone or Blackberry which in turn sends the call to predetermined recipients using wireless technology. The call or alert message may also include location coordinates using GPS and the time of day. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to fire-fighting equipment, and more specifically to equipment coupled to a fire hose or pipeline for integrating an additive to a water stream.
Fire fighting systems typically include a fire truck, such as truck T in FIG. 1 , which includes a pumping unit P that pumps water under high pressure from a tanker truck or a nearby fire hydrant, through a fire hose H 1 , H 2 and nozzle N. While water alone is sufficient for most fires, some fires cannot be efficiently controlled or extinguished by water alone. In this case, certain chemical additives are introduced into the water line to be discharged onto the particular type of fire. Incidents involving flammable liquids or hazardous materials often require the use of a foam that is spread over the fire to starve the fire of oxygen or to suppress noxious vapors. For instance, Class A foam concentrates are used for wildland, rural and urban fire suppression on Class A fuels, such as wood, paper and other solid materials. Class B foam concentrates are primarily intended for Class B materials, such as flammable liquids containing hydrocarbons or polar solvents, and can be used for vapor suppression or extinguishment.
There are numerous approaches to introducing chemical additives or foam concentrates into the flow through firefighting water lines. Some systems utilize additive pumps for forced injection of the chemical into the water line. Such systems are generally complicated and are not portable. On the other hand, portable systems rely upon the movement of water through the fire hose to educe the chemical. In the context of the present invention, educe or induct means that liquid is drawn into the system, such as by the flow of another liquid. In one typical arrangement, a foam bucket F contains a liquid foam concentrate that is induced into the fire hose H 2 by a foam eductor valve E. This typical eductor valve E relies upon venturi flow to draw the foam concentrate from the foam bucket F into the water stream passing through the eductor E.
The chemical additives or foam concentrates are often corrosive and usually expensive. Thus, the typical eductor valve E includes a check valve system to prevent backflow of water into the chemical supply. For instance, the by-pass eductor described in U.S. Pat. No. 5,960,887, includes a ball check valve integrated into a foam concentrate metering valve.
While the check valve is important to prevent water backflow, it can be problematic with respect to cleaning the eductor valve E. In fire-fighting equipment back-flow typically occurs when the discharge nozzle N is shut off or when the hose H 2 is kinked so that fluid discharge is terminated. Without cleaning, the chemicals passing through the valve may congeal and foul the valve or the metering orifice used to control the quantity of chemical introduced into the water stream. In an extreme case, the valve may be stuck open or closed. Prior devices require disengaging the eductor valve from the water line, connecting the water supply hose H 1 to the chemical inlet of the eductor valve E, and flushing the valve with water. This process is cumbersome, but perhaps more significantly this approach can be hazardous. In particular, disengaging a eductor valve filled with a chemical additive of foam concentrate will necessarily result in a chemical spill.
What is needed is an eductor valve apparatus that satisfies all of the necessary functions of an eductor, but that is easy and safe to clean. Such an apparatus would allow controlled flushing so that the chemicals can be safely collected without risk of spilling. A further need is the ability to readily determine the position of the check valve and to manually alter it.
SUMMARY OF THE INVENTION
To address this unmet need, the present invention contemplates a system for preventing actuation of a check valve within an eductor assembly. In one embodiment, the present invention contemplates an eductor assembly for use with firefighting equipment that comprises an eductor body defining a fluid inlet connectable to a source of a firefighting fluid (e.g., high pressure water), a fluid outlet for dispensing fluid therefrom in fluid communication with the fluid inlet, and an additive inlet connectable to a source of an additive to the firefighting fluid and in fluid communication with the fluid outlet. The additive can be, for example, a foam concentrate that is educed to mix with the high pressure water under venturi flow.
The eductor assembly further comprises a check valve disposed between the additive inlet and the fluid outlet that is moveable, in response to a flow of water through the fluid inlet, between a first position operable to prevent back flow of water through the additive inlet and a second position to permit flow of additive through the additive inlet to the fluid outlet. In other words, the check valve is open to permit the eduction of the additive under proper venturi conditions, but otherwise closes the additive inlet.
In one important feature of the invention, means are provided for holding the check valve in its open position while allowing water back flow through the additive inlet. This feature allows the additive fluid circuit to be back flushed and thus cleaned after use. In one embodiment, this means includes an actuator operable from outside the eductor body to move the check valve to the second position. In a more specific embodiment, this actuator is an elongated pin having a proximal end manually accessible outside the eductor body and an opposite working end engageable with the check valve to move the check valve to the second position. The actuator preferably includes a push button mounted to the proximal end of the pin to facilitate manual operation of the actuator.
Preferably, the actuator pin is sized so that it does not contact the check valve in its non-actuated position. In the preferred embodiment, means are provided for biasing the pin to this non-actuated position away from engagement with the check valve. When the push button is manually pressed, the pin moves against this biasing means to contact and push the check valve to its open position.
The eductor assembly further comprises a metering head in fluid communication with the additive inlet, in which the metering head includes a metering inlet connectable to the source of the additive and an adjustable metering element disposed between the metering inlet and the additive inlet. The actuator is supported by the metering head to engage the check valve to move the check valve to the second position. Where the actuator is an elongated pin, the pin is slidably disposed within the metering head and has a proximal end manually accessible outside the metering head and an opposite working end engageable with the check valve to move the check valve to the second position.
In one embodiment, the metering element is connected to a proportioning knob movably mounted to the metering head, and the knob defines a recess for receiving the push button and a bore communicating with the recess slidably receiving the pin therethrough. In a further feature, the eductor assembly includes a mating assembly between the metering head and the additive inlet of the eductor body for removably coupling the metering head thereto. This mating assembly allows removal of not only the additive metering components, but also the actuator pin and push button.
Preferably, the actuator includes a spring between the push button and the proportioning knob within the recess. The spring is arranged to bias the pin away from engagement with the check valve. In certain embodiments, the pin extends through the metering element, which can comprise a hollow proportioning ball defining a plurality of differently sized metering openings arranged to be selectively aligned with the metering inlet, and a hollow stem coupled to the proportioning ball and defining a passageway to slidingly receive the pin. A fluid sealing element or seal ring may be disposed between the pin and the hollow stem.
In the preferred embodiment, the check valve includes a valve disc sized to close the additive inlet in the first position and a number of alignment wings projecting from the valve disc into the additive inlet when the check valve is in either of the first and second positions. Thus, the wings maintain the position of the check valve as it moves between its open and closed positions. The wings are sufficiently dispersed to allow substantially unimpeded flow of additive of water back flow through the additive inlet. In a specific embodiment, the number of wings defines a hub arranged to be engaged by the actuator pin when the actuator is operated to move the check valve to the second position.
The invention further contemplates a method of cleaning an eductor assembly used to introduce an additive to a flow of water through a venturi nozzle. The eductor assembly includes an eductor body defining the venturi nozzle, an additive inlet in fluid communication with the venturi nozzle and a check valve disposed between the additive inlet and the venturi nozzle that is open when the venturi nozzle produces suction to educe additive through the additive inlet, and is otherwise closed to prevent back flow through the additive inlet of water passing through the venturi nozzle. The preferred embodiment of the method comprises the steps of moving the check valve to its open position, holding the check valve in that position and then flowing water through the venturi with the check valve open to produce back flow of water through the additive inlet. Preferably, the holding step includes manually depressing an actuator pin slidably disposed within the eductor assembly to push the check valve into its open position.
It is one object of the present invention to provide a system and method for cleaning an eductor assembly that is used for introducing a chemical additive, such as foam concentrate, into a flow of water used to battle a fire.
One benefit of the invention is that the inventive eductor valve apparatus satisfies all of the necessary functions of an eductor, but is easy and safe to clean. A further benefit of the apparatus is that it allows controlled flushing so that the chemicals can be safely collected without risk of spilling. Yet another benefit is provided by the ability to readily determine the position of the check valve and to manually alter it.
Other objects and benefits of the invention will become apparent upon consideration of the following written description, taken together with the accompanying figures.
DESCRIPTION OF THE FIGURES
FIG. 1 is a pictorial representation of a fire truck equipped for dispensing a foam for fire or vapor suppression or extinguishment.
FIG. 2 is a perspective view of the components of an eductor assembly in accordance with one embodiment of the invention.
FIG. 3 is an exploded view of the eductor assembly depicted in FIG. 2 .
FIG. 4 is a side partial cross-sectional view of the eductor assembly shown in FIGS. 2-3 .
FIG. 5 is an enlarged perspective view of a check valve for use in one embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains.
In accordance with one embodiment of the invention, the eductor valve E shown in FIG. 1 includes an eductor assembly 10 , as illustrated in FIG. 2 . This assembly includes a main body 11 having a water inlet 13 and an outlet 15 . A foam inlet 17 intersects the inlet and outlet and is configured to mate with a metering head 20 . The metering head 20 is connected to a suction hose 22 that terminates in a wand 23 . The wand 23 is configured to engage the foam bucket F ( FIG. 1 ) in a conventional manner to draw foam concentrate from the bucket by venturi flow of water through the main body 11 . The metering head 20 includes a mating ring assembly 27 that is configured for quick connect and disconnect to the foam inlet 17 . A proportioning knob 25 can be rotated to adjust the quantity of chemical additive fed through the metering head 20 into the main body 11 .
As shown in the detail view of FIGS. 3 and 4 , the eductor assembly as thus far described is of known construction. For instance, the main body 11 is hollow and defines a plenum 12 ( FIG. 4 ) into which the chemical or foam additive is drawn. A blending tube 35 is situated at the inlet 13 of the body 11 , terminating in a nozzle end 37 within the plenum 12 . A coupling assembly 39 mounts the blending tube 35 within the body and provides an interface for engagement to a fire hose H 1 ( FIG. 1 ). The coupling assembly 39 can be of known construction, including, for instance, a ball bearing mounted threaded coupling ring sized to mate with a 1½ inch fire hose connection. The coupling assembly 39 facilitates ready removal and replacement of the blending tube 35 to substitute a tube sized for different water flow rates.
At the outlet 15 , the body 11 mates with a discharge nozzle 42 . The nozzle 42 terminates in a nozzle end 44 within the plenum 12 and is arranged to receive water or a water/chemical mixture when water is supplied under pressure at the inlet 13 . The discharge nozzle 42 includes a coupling end 45 that is configured in a known manner for engagement to a hose H 2 or nozzle N. The discharge nozzle 42 is configured for threaded engagement within the main body 11 . Different discharge nozzles can be provided with differently sized outlets 15 to achieve selectable exit flow rates. In addition, the size of the inlet 13 to the eductor is preferably correlated to the discharge nozzle outlet size to achieve these flow rates.
The metering head 20 mates with the additive or foam inlet conduit 47 of the main body 11 . The mating ring assembly 27 can be configured in a known manner to provide a quick connect/disconnect fitting arrangement, as depicted in FIG. 3 . The mating ring assembly 27 allows a number of metering heads to be engaged to an eductor body depending upon the desired chemical/foam flow rate.
The metering head 20 includes a metering body 50 that defines a foam inlet 52 . A fitting assembly 24 connects the suction hose 22 to the metering body in a known manner. The metering body defines a cavity 51 that communicates with the inlet 52 . A proportioning ball 54 resides in and is rotatable within the cavity to align a plurality of differently sized metering orifices 56 with the inlet 52 . In a specific example, the proportioning ball includes five orifices of different sizes and shapes to correspond to different proportional settings for foam consumption, as well as a no flow or “off” setting in which the foam inlet 52 is blocked. In this specific example, the orifices correspond to ¼%, ½%, 1%, 3% and 6% ratios of foam concentrate to water volume. The two smaller settings correspond to small orifice diameters and are typically better suited for Class A foams. The larger settings are typically better suited for Class B foams.
The proportioning ball 54 includes a stem 60 that extends through a bore 53 in the metering body. The stem 60 is connected to the proportioning knob 25 to rotate with the knob. In a specific embodiment, the stem 60 extends through a bore 76 in the knob and includes a notch 61 that can interlock with a rib (not shown) within the bore so that the two components rotate together. An O-ring 58 between the proportioning ball 54 and the metering body helps prevent leakage through the bore 53 . As best seen in FIG. 4 , the metering ball 54 provides a fluid path from the foam inlet 52 through a selected metering orifice 56 and into the cavity 51 of the metering body. The knob preferably includes indicia corresponding to the position of the proportioning ball 54 relative to the foam inlet 52 .
When the metering head 20 is mounted on the eductor main body 11 , the metering cavity 51 communicates with the plenum 12 through a passageway 49 defined in the additive inlet conduit 47 . As is known in the art, water flowing from the nozzle end 37 of the blending tube 35 into the nozzle end 44 of the discharge nozzle 42 causes a pressure drop within the plenum. This pressure drop pulls or educts fluid from the foam bucket F through the wand 23 , creating a high speed flow of the chemical additive or foam concentrate. This educed fluid mixes with the water as it is discharged through the discharge nozzle 42 .
In order to prevent unwanted backflow of water from the plenum into the metering head 20 , a check valve 30 is provided within the foam inlet conduit 47 , as shown in FIGS. 3-4 . In a preferred embodiment of the invention, the check valve 30 includes a valve disc 85 that has a diameter greater than the diameter of the passageway 49 defined in the inlet conduit 47 . More specifically, the valve disc 85 is sized to engage a valve seat 49 a to completely close the passageway 49 to prevent the backflow of water into the inlet conduit and metering head.
The check valve 30 includes an arrangement of wings 87 projecting upward from the disc 85 into the passageway 49 . The wings are configured to constrain and guide the check valve so that it translates along the axis of the passageway and so that the valve disc 85 seats flush with the valve seat 49 a in the main body 11 to close the passageway 49 . The upper surface of the disc 85 can include a resilient seal ring 91 to improve the sealing capability of the check valve. Alternatively, the disc itself can be formed of a resilient material that deforms slightly under fluid pressure to form a tight seal against the main body. In the preferred embodiment, the check valve, including the disc 85 and wings 87 , is formed of a plastic material.
The wings 87 have a height calibrated so that the wings remain substantially disposed within the passageway even when the valve disc 85 is in contact with one or both of the nozzle ends 37 , 44 . Under normal operating conditions, the valve disc 85 will remain trapped between the nozzle ends and the additive inlet as the venturi suction pulls the disc downward and induces chemical fluid flow through the metering head 20 . However, once the venturi suction falls below a threshold value, or when no fluid is flowing through the metering head, the inlet water pressure will push the check valve upward until the valve disc seals against the main body and closes the inlet passageway 49 . This condition will occur in response to a termination of the flow downstream, such as when the nozzle N is shut off or when the hose H 2 is kinked. Under normal operating conditions, the check valve will remain closed (preventing backflow into the metering head) when the fire hose nozzle N ( FIG. 1 ) is off, since there is no flow through the eductor to produce venturi suction. However, once the nozzle is opened, water flow commences and the check valve opens to draw the chemical additive or foam concentrate into the plenum 12 .
As thus far described, the check valve 30 presents the same problem experienced by the prior eductor valves with respect to cleaning the eductor assembly 10 . In order to alleviate this problem, the present invention contemplates a system for holding the check valve 30 in an open position—i.e., with the valve disc 30 unseated or offset from the eductor body, leaving the passageway 49 substantially unobstructed even under water pressure. In order to achieve this objective, the preferred embodiment of the invention includes a back flush pin 65 ( FIGS. 3-4 ) that bears against a contact hub 89 defined at the peak of the wings 87 (see FIG. 5 ). The pin 65 is slidably disposed within a passageway 62 defined in the stem 60 of the proportioning ball 54 . Thus, while the proportioning ball is fixed in translation along the cavity 51 , the pin 65 is free to move vertically downward into contact with the hub 89 of the check valve 30 to push the valve downward away from the passageway 49 . For the purposes of the present disclosure, the “vertical” direction is defined as along the axis of the metering body 50 , and “downward” is movement toward the eductor body 11 .
In the illustrated embodiment, the proportioning knob 25 defines a recess 75 within the metering body 50 that communicates with the bore 76 . As explained above, the stem 60 of the proportioning ball 54 interlocks with the knob 25 within this bore. O-ring 58 provides a fluid tight seal between stem 60 and metering body 50 . A cross pin 69 passes through a bore 68 ( FIG. 3 ) in the back flush pin to set an upper limit for the travel of the pin. An O-ring 73 is mounted within a seal ring groove 74 in the pin 65 to provide a fluid-tight seal between the pin and the passageway 62 as the pin translates within the bore.
A push button 79 is threaded onto the end of the back flush pin 65 , trapping a return spring 77 within the recess 75 . The top end of the back flush pin 65 defines an internally threaded bore 71 to receive a locking screw 81 for fixing the back flush pin 65 to the push button 79 . The push button 79 is accessible above the proportioning knob 25 so that the button can be manually depressed when it is desired to clean the eductor assembly 10 . When the button is pushed, the back flush pin 65 is driven downward to push against the check valve 30 . With the button 79 fully depressed, the check valve is clear of the passageway, creating a back flush flow path from the water inlet 13 through the eductor assembly 10 . The eductor assembly does not need to be disconnected from the water supply, but instead remains connected as it was during the firefighting action. Water from the pumping unit P of the fire truck T, through fire hose H 1 , can be supplied directly to the eductor assembly to flush all of the chemicals out of the assembly components. The flushed liquid is discharged through the suction hose 22 and wand 23 , which means that the wand can be placed within an appropriate receptacle to receive the back flush liquid waste.
In a typically cleaning process after use, the wand is removed from the foam supply F and optionally placed in a discharge container. The water flow through the supply hose H 1 is significantly reduced from the typical fire-fighting water pressure and flow rate. In a specific embodiment, the back flush water pressure is reduced to below 45 psi (as compared to a typical operating pressure of about 200 psi). With the nozzle N closed (to prevent water flow through the hose H 2 ), the back flush button 79 is depressed to release the check valve 30 and allow the water to flow back through the metering body 50 , suction hose 22 and suction wand 23 . The proportioning knob 25 rotated as the water continues to back flush so that water passes through every foam metering orifice 56 in the proportioning ball 54 . Back flushing continues at each metering setting until there is no visible foam in the flush water. At that point, the water supply is stopped and the metering head 20 is removed from the main body 11 by manipulating the mating ring assembly 27 . The residual water within the metering body 50 and main body 11 can be gravity drained.
Under certain conditions, the check valve 30 may not properly engage the valve seat 49 a ( FIG. 4 ) to fully close the passageway 49 . In order to ensure a proper sealing engagement, the check valve 30 may be provided with a return element 100 , as shown in FIG. 5 . The return element 100 includes a ring 102 that defines an opening that is preferably larger than the flow path through the outlet 15 so as not to impede the flow of fluid through the eductor 10 . A base 104 is provided on the ring to bear against the wall of the plenum 12 .
The element 100 further includes an elongated stem 106 projecting upward from the ring 102 . The stem passes through a bore 107 defined in the hub 89 of the check valve 30 . In the preferred embodiment, the stem 106 is long enough to pass completely through the check valve bore 107 .
The ring 102 is formed of a corrosion resistant material that is flexible and resilient. In a preferred embodiment, the ring is formed of a thermoplastic elastomer, such as ALCRYN®. When the back flush pin 65 is depressed, the check valve 30 bears against the ring 102 to deform the ring. In a preferred embodiment, the ring 102 is circular in its installed shape, and becomes generally oval as it is deformed under pressure from downward movement of the check valve. The return element is configured so that it can be deformed when the check valve opens under venturi pressure. In the preferred embodiment, the opening force due to venturi pressure is about ½ ounce. In addition, when the back flush pin 65 is depressed, the check valve 30 bears against the ring 102 to deform the ring. When the back flush pin is release, the ring 102 seeks its neutral shape so that it springs back to its original oval shape. In so doing, the ring 102 pushes the check valve 30 upward into engagement with the valve seat 49 a . Moreover, as the ring 102 pushes the valve upward, the stem 106 keeps the check valve in proper alignment so the disc 85 bears fully against the valve seat.
In certain embodiments, the ring 102 is sized so that in its neutral or un-deformed shape the base 104 contacts the wall of the plenum 12 while the top of the ring is also in contact with the disc 85 of the check valve. Alternatively, the ring may be sized so that the top of the ring 102 is slightly offset from the disc 85 so as not to impede the downward movement of the check valve under venturi pressure only. However, in this alternative, the ring is sized so that the ring may be deformed when the back flush pin 65 is fully depressed.
In the preferred embodiment, the return element is in the form of a ring so that the return spring force produced by the element 100 will be directed substantially along the axis of the elongated stem 106 . Other forms of the return element may be contemplated provided that the element does not interfere with the flow of fluid through the eductor and that the element operates to accurately return the check valve to the valve seat. For example, in lieu of the complete ring 102 , the return element 100 may include a pair of resilient legs extending downward and outward from the check valve to contact the side walls of the plenum 12 .
The internal components of the eductor assembly 10 are formed of materials that are compatible with the types of chemical additives or foam concentrates flowing through the assembly. The component materials are preferably non-reactive with the chemicals and resistant to the corrosive effects of these chemicals. In a specific embodiment, the wand 23 and the back flush pin 65 , and ancillary hardware are formed of stainless steel, as is the back flush pin 65 . On the other hand, the blending tube 35 can be formed of a high density plastic. Preferably, all the other components are formed of a metal, such as aluminum that has been hard anodized. The proportioning ball 54 and integral stem 60 are also preferably formed of a high density plastic, which beneficially provides a smooth sliding surface for the O-ring 73 as the back flush pin 65 reciprocates within the passageway 62 .
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.
For instance, while the illustrated embodiment of the check valve contemplates a disc valve, other one-way valves can be utilized. For instance, a ball valve can be situated within the plenum 12 so that the ball seals against the passageway 49 . A cage may contain the ball in alignment with the passageway. The same back flush pin 65 described above can be arranged to bear against the check ball to prevent it from seating over the passageway. In this instance, the pin 65 and inlet conduit 47 would be commensurately sized so that the pin is clear of the ball valve during normal use but is capable of extension into contact with the ball when it is desired to back flush the eductor assembly.
Similarly, the check valve can be a resilient valve, such as a duckbill valve. With this type of valve, the working end of the back flush pin can be modified to hold open the duckbill when the pin is pushed through the valve.
As a further example, the illustrated embodiment contemplates a push button feature for actuating the back flush pin 65 . Other means and mechanisms for actuating the pin are contemplated by the present invention. For instance, a pivoting or sliding lever can be integrated into the side wall of the metering body so that manipulation of the lever will push the check valve to its open position. Non-contact actuation is also contemplated, such as a magnetically coupled valve. | An eductor assembly includes an inlet connectable to a high pressure water source useful in firefighting, an outlet connectable to a fire hose and/or nozzle, and a venturi therebetween. An additive inlet communicates with the venturi so that a chemical additive, such as a foam concentrate, is educed into the output stream. A check valve is positioned at the additive inlet to open under venturi flow conditions and remain closed otherwise. An actuator is provided that holds the check valve in its open position while water flows through the eductor assembly under non-venturi conditions to produce a back flow through the additive inlet and ultimately through the additive fluid circuit, including the additive metering valve components. A return element may be disposed within the eductor body to return the check valve to its closed position when the back flow ceases. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to event management of distributed systems and, more particularly, to techniques for automatic and semi-automatic validation, completion and construction of event relationship networks.
[0002] BACKGROUND OF THE INVENTION
[0003] High quality event management has long been seen as the cornerstone of a healthy business and Information Technology (IT) operation environment. As every business is becoming an electronic business (e-business), the demand from IT service customers has evolved from reactive management toward proactive management. Enormous academic research and commercial products have attempted to achieve proactive management by root cause analysis (RCA). However, what RCA can provide does not match well with the needs of two primary goals of event management:
[0004] (1) Rapid detection of, and a fast response to, exceptional situations; and
[0005] (2) Precise and accurate identification of the problem scope (hosts, networks, people, etc.).
[0006] In response to these real-world operational demands, a new paradigm referred to as action-oriented analysis (AOA) has recently been proposed, see, e.g., Thoenen et al., “Event Relationship Networks: A Framework for Action Oriented Analysis for Event Management,” International Symposium on Integrated Network Management, 2001, the disclosure of which is incorporated by reference herein. The concepts of AOA is concretized as the Event Management Design (EMD) methodology which contains four activities:
[0007] (1) Select the event sources;
[0008] (2) Take inventory of all events;
[0009] (3) Document event policy and processing decisions; and
[0010] (4) Construct Event Relationship Networks (ERNs) for correlation analysis.
[0011] By examining these activities, we can see that activity (1) is relatively straightforward for system administrators since important event sources (e.g., Unix servers, NT servers, NetWare Severs, hubs, routers, ATM switches, UPS systems, applications, web servers, database servers, etc.) are very easy to identify. Activity (2) mostly relies on the quality and coverage of service providers' event source repertoires and their quality of knowledge management. Activity (3) involves customizing policy specifications and making processing decisions for the particular operation environment based on its special requirements. Activity (4) involves constructing ERNs, an ERN being a graphical representation of how events are correlated.
[0012] IBM Global Service has developed a toolset that translates a set of ERNs along with a default action template to event correlation rules ready to be used in event correlation engines like the Tivoli Enterprise Console. Therefore, activity (4) is the pivotal step of the EMD methodology. Proportional to the significance, our experience shows activity (4) usually requires the most time and domain expertise.
[0013] ERN construction can be significantly sped up if the service providers have corresponding ERNs as their intellectual capital. However, there are roughly 11,000 types of event sources currently working in business environments that might be taken in event management. Considering the tremendous diversity of event sources, such advantage should not be expected. Furthermore, the same type of event sources may be configured very differently in different operation environments. Also, the decisions about event processing policies may invalidate ERNs constructed under different policies.
[0014] These constraints indicate that revising and constructing ERNs are unavoidable in most cases. Consider a typical operation environment containing 20 event sources and 100 enterprise significant event types for each event source. Domain and device experts have to mentally figure out all the autonomous events among the 2000 event types and the correlations among the rest, and document them into ERNs. The time and cost that have to be spent on constructing ERNs is significant.
[0015] Beside the cost of constructing ERNs, the correctness and effectiveness of ERNs also have a great impact on the performance of event management. On one hand, incomplete ERNs cause correlation engines to fail to correlate events that are “symptoms” of the same “problem” and initiate more than enough notifications or actions, thus, deteriorating the second goal of event management. On the other hand, incorrect ERNs cause correlation engines to fail to take proper action or notify the correct people, thus, violating the first goal of event management. Worst of all, ERNs can be both incomplete and incorrect. The need of a method to validate and construct ERNs based on true and complete correlations is apparent.
SUMMARY OF THE INVENTION
[0016] The present invention provides techniques for using event data to automatically and semi-automatically validate, complete and construct event relationship networks (ERNs).
[0017] In a first aspect of the invention, a computer-based technique for use in accordance with an event management system comprises the following steps. One or more event relationship networks are automatically generated from event data, wherein an event relationship network comprises nodes representing events and links connecting correlated nodes. Then, the one or more generated event relationship networks are utilized to construct one or more correlation rules for use by a correlation engine in the event management system. In a semi-automatic portion of the technique, the one or more generated event relationship networks may be subjected to human review prior to utilizing the one or more generated event relationship networks to construct the one or more correlation rules.
[0018] In a second aspect of the invention, when one or more previously generated event relationship networks are available, the step of automatically generating one or more event relationship networks may comprise the following steps. First, one or more previously generated event relationship networks are obtained. Next, the one or more previously generated event relationship networks are validated by removing any nodes or links included therein that are incorrect for a particular application context. Then, the one or more previously generated event relationship networks are completed by adding any nodes or links thereto that are missing for the particular application context. Lastly, the one or more validated and completed event relationship networks are output as the one or more event relationship networks used to construct the one or more correlation rules.
[0019] The validating and completing steps preferably utilize a statistical correlation analysis. The statistical correlation analysis may utilize pairwise correlation analysis, wherein correlation between a pair of events is measured in accordance with one or more statistical measurements. Further, the validating step may comprise, for a particular event relationship network, determining that links in the event relationship network have a confidence level not less than a given threshold. This operation corresponds to validation of a weak correlation semantic. Still further, the validating step, for a particular event relationship network, may comprise: splitting the event relationship network into correlation paths; for every correlation path, remove a node that has the least number of correlated nodes associated therewith until every node is fully correlated with every other node; and merging correlation paths into one or more event relationship networks such that every path in a resulting event relationship network has every node fully correlated with every other node in the path. This operation corresponds to validation of a strong correlation semantic.
[0020] In a third aspect of the invention, when one or more previously generated event relationship networks are not available, the step of automatically generating one or more event relationship networks may comprise the following steps. First, patterns are mined or discovered from the event data. The mined patterns are then utilized to construct the one or more event relationship networks. Lastly, the one or more event relationship networks constructed from the mined patterns are output as the one or more event relationship networks used to construct the one or more correlation rules. The constructing step preferably utilizes a statistical correlation analysis to mine patterns. As above, the statistical correlation analysis may utilize pairwise correlation analysis.
[0021] In a fourth aspect of the invention, the one or more event relationship networks generated with the techniques described above may comprise annotations relating to statistical correlation between nodes.
[0022] Further, the event data used in the event relationship network generation techniques of the invention is preferably obtained from an event log representing historical events associated with a particular system being managed by the event management system. Still further, the event data may be preprocessed (e.g., throttled) prior to use in generating the one or more event relationship networks by removing at least a portion of any redundant events.
[0023] These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 is a diagram illustrating an event relationship network according to an embodiment of the present invention;
[0025] [0025]FIG. 2 is a block diagram illustrating an operational model associated with an event correlation engine according to an embodiment of the present invention;
[0026] [0026]FIG. 3 is a table illustrating an event log according to an embodiment of the present invention;
[0027] [0027]FIG. 4 is a diagram for use in illustrating an incorrect global correlation;
[0028] [0028]FIG. 5 is a diagram illustrating the concept of ERN stratification according to an embodiment of the present invention;
[0029] [0029]FIG. 6 is a diagram further illustrating the concept of ERN stratification according to an embodiment of the present invention;
[0030] [0030]FIG. 7 is a diagram illustrating the concept of ERN validation according to an embodiment of the present invention;
[0031] [0031]FIG. 8 is a diagram illustrating a process of validating an ERN by event logs according to an embodiment of the present invention;
[0032] [0032]FIG. 9 is a diagram illustrating a process of completing and constructing an ERN according to an embodiment of the present invention;
[0033] [0033]FIG. 10 is a block diagram illustrating an ERN validation, completion and construction system according to an embodiment of the present invention;
[0034] [0034]FIG. 11 is a diagram illustrating an ERN validation, completion and construction process according to an embodiment of the present invention; and
[0035] [0035]FIG. 12 is a block diagram illustrating a generalized hardware architecture of a computer system suitable for implementing an ERN validation, completion and construction system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] It is known that true and complete event correlations are typically impossible to obtain because operational environments are always changing. However, the present invention realizes that the past is still the best indicator of the future. It is a norm that event correlation servers and middle layer managers have the capabilities of maintaining event repositories, typically in relational databases. The present invention, therefore, realizes that this historical event data provides the most reliable evidence of how one type of event is temporally correlated to other types of events. The present invention further realizes that the correlation implied in event data is very useful in confirming domain experts' hypotheses and, sometimes, providing surprising facts.
[0037] As mentioned, the present invention provides techniques for using event logs to validate, complete and construct event relationship networks (ERNs). In the remainder of the detailed description of the invention below, a brief description of ERNs is given. Next, an explanation is given on how to preprocess event data, via throttling, and obtain no redundant events. Then, a pairwise correlation measurement based on probabilistic and statistical concepts is described. With pairwise correlation defined, two semantics of global correlation are provided, namely, weak correlation and strong correlation. Then, a procedure for performing ERN validation, completion and construction is explained. In addition, an illustrative system structure and operating process are explained.
[0038] The approach taken by the present invention to describe correlation logic uses a conceptual framework called event relationship networks or ERNs. An ERN is a directed cyclic graph. Nodes are events and are labeled with the role of the event within the case. Arcs or links from one event to the next indicate that the latter is associated with or correlated with the former.
[0039] [0039]FIG. 1 is a diagram illustrating a simple event relationship network. In this example, a device on the distributed computing network that is being managed is referred to as a “chassis subagent.” The chassis subagent emits “minor” and “major” alarm events as problematic incidents escalate in accordance with power supply units associated with the chassis subagent, namely, PS 1 and PS 2 . As chassis status returns to normal the subagent emits an “alarmOff” event.
[0040] A key concept referred to herein as “event roles” is also introduced in FIG. 1. An event plays a primary role (i.e., is a primary event) if it provides an immediate, often unambiguous, indication as to the corrective action to take. For example, if a warning trap is the first event in the correlation case, then it is a primary event. Proactive management uses the receipt of a primary event to trigger a first level of response. As depicted in FIG. 1, the role of the chassisMinorAlarmOnPS 1 and chassisMinorAlarmOnPS 2 events are primary within the context of this example correlation case.
[0041] An event plays a secondary role (i.e., is a secondary event) if it is always extraneous in terms of selecting the corrective action in an exceptional situation. Although secondary events do not affect the choice of corrective action, they may invoke actions of their own.
[0042] If events were always either primary or secondary, then correlation would be much less complex. However, in a large number of cases, the role of an event depends on context within the correlation case. Events that may be either a primary or a secondary are called primary/secondary events. Within our example correlation case in FIG. 1, two events act in the role of primary/secondary, namely, the chassisMajorAlarmOnPS 1 and the chassisMajorAlarmOnPS 2 events.
[0043] There is an event role specified by events that identify the end of an incident. We refer to these as clearing events. Within our example correlation case in FIG. 1, chassisMinorAlarmOffPS 1 and chassisMajorAlarmOnPS 2 act in the role of the clearing event.
[0044] Referring now to FIG. 2, a block diagram illustrates an operational model associated with an event correlation engine according to an embodiment of the present invention. It is to be understood that the operational purpose of constructing ERNs is to instruct correlation servers, on which correlation engines reside, a proper way to process events. So the semantics of the links in ERNs should be interpreted as the way correlation servers work. Correlation servers can be modeled as a rule-based trigger system with an event cache. Thus, as shown in FIG. 2, a correlation server 200 comprises a correlation engine 202 , an event cache 204 , an event throttling module 206 , an event repository 208 and a problem reporting system 210 .
[0045] As shown, raw events 212 are received by the correlation server 200 . The raw events are preprocessed, via event throttling module 206 , such that redundant events are removed. Event throttling will be explained below in greater detail. The preprocessed events 214 are then stored in event cache 204 .
[0046] Thus, at any moment, the event cache 204 contains events received during the last period of a predefined duration. The rule-based triggering system (i.e., in accordance with the correlation engine 202 and the correlation rules implemented thereby) examines the content of the event cache 204 and determines whether any trigger rule should fire. The firing of a trigger rule results in the generation of a trouble ticket 218 which is sent on to the problem reporting system 210 for action to be taken by an operator and/or some response system in the network. Events 216 may be stored for further use in the event repository 208 .
[0047] In this operational model, it is to be appreciated that event correlation is a temporal relationship. Such correlation capabilities are at the heart of systems management. Thus, we can apply algorithms and techniques developed for finding temporal coupling relationships.
[0048] Referring now to FIG. 3, a table illustrates an event log according to an embodiment of the present invention. It is to be understood that an event log, which as will be explained below is used to generate ERNs, may represent a portion of event data stored in the event cache 204 and/or the event repository 208 . As shown, the event log 300 includes entries associated with an event for: timestamp 302 ; trap (or alert type) 304 ; time 306 ; host (or source of event) 308 ; category 310 ; and message 312 . Each row 314 through 334 represents information associated with a particular event. By examining the event log, we can see evidence that supports some common correlation, for example, correlation between “Node_Up” and “Interface_Up” (with respect to host 3 in rows 320 and 322 ) and correlation between “Node_Down” and “Interface_Down” (with respect to host 6 in rows 332 and 334 ).
[0049] We can also see certain correlations that might somewhat surprise ERN designers. For example, we can see there are two cases (events 316 and 318 associated with host 2 and events 324 and 326 associated with host 4 ) that “Interface_Up” is correlated with “Node_Marginal.” While “Interface_Up” is commonly regarded as an indicator that the host has been restored from non-operational status, a “Node_Marginal” event indicates the host is likely overloaded. Provided such observation, domain experts can look into the phenomena and determine the meaning of the correlation. It is most likely to be the case that “Node_Marginal” is simply a transient stage when a host is restoring the connection of the interface so host 2 and host 4 are working normally after time 00:40:59.
[0050] If the ERN designer erroneously considers every “Node_Marginal” as a problem, the consequence is twofold. First, many unnecessary trouble tickets will be issued. Second, the produced correlation rules could cause the correlation engine to keep those events in local cache all the time, hence, degrading the pattern matching performance.
[0051] As previously illustrated in the operational model of a correlation server in FIG. 2, raw events usually require preprocessing before being put into statistical testing. A common practice in event preprocessing is throttling. The purpose of throttling is to remove redundant events from the event stream before the event correlation server processes them.
[0052] For example, some probing events are generated periodically when a monitor agent has sensed anomalies. If the problem persists, the number of these periodically generated events tends to be much greater than the number of anomalies. Without throttling, events that occasionally happen together might be evaluated to a high confidence of coupling because the event repetition amplifies the coupling.
[0053] The following is a description of an illustrative throttling system that may be implemented to preprocess the raw event data. The system is parameterized by a 4-tuple (type, count, time period, time unit) where type is one of “First,” “At” and “After;” count and time period are integers, and time unit is one of “Seconds,” “Minutes,” “Hours” and “Days.” The meaning of the set of parameters can be exemplified as follows:
[0054] (First, 2, 5, Minutes): forward only first 2 event and ignore other occurrences of the event within the 5-minute time period.
[0055] (At, 3,1, Hours): forward only the 3rd event occurring in the one-hour time period.
[0056] (After, 2, 3, Minutes): forward all events occurring in the 3-minute time period after the 2nd event.
[0057] Historical event logs available for correlation analysis may be unprocessed reception logs of correlation engines. The same throttling process should be applied to historical event logs.
[0058] Thus, given the above description of how a correlation server may operate, the following portion of the detailed description provides illustrative event correlation criteria that may be used to construct correlation rules for use by the correlation engine in accordance with an ERN.
[0059] First, we provide a concept referred to as pairwise correlation. It is to be appreciated that the concept of pairwise correlation is described in the U.S. patent application identified by attorney docket no. YOR920010747US1 filed concurrently herewith and entitled: “Systems and Methods for Pairwise Analysis of Event Data,” the disclosure of which is incorporated by reference herein. While pairwise correlation is a preferred criteria for generating correlation rules from patterns in the event data, it is to be understood that other techniques may be used.
[0060] Recall that an ERN is a directed cyclic graph. Nodes are events and are labeled with the role of the event within the case, while links from one event to the next indicate that the latter is associated with or correlated with the former. In accordance with the concept of pairwise correlation, the invention employs two types of correlation: (1) weak global correlation; and (2) strong global correlation. Both types of correlation provide a way to compute link confidences. We assume a reasonable window length w that will be set as the time window of the event cache. For each link (A,B), we compute the following confidence statistics:
Conf AB=<N A ,P B|A , χ AB 2 >,
[0061] where:
[0062] N A is the total number of occurrences of event type A. N A indicates whether the event type A, as well as the link, are worth being included in an ERN. In a sense, N A represents the possible cost of applying an incomplete ERN. As previously stated, incomplete ERNs can cause unnecessary trouble tickets. The cost of processing these redundant trouble tickets caused by missing link (A,B) is proportional to N A . So, for a large N A , the link is included in the ERN if other statistics also indicate high correlation. For a small N A , the “cost” of the decision is up to the domain expert's judgment.
[0063] P B|A is the conditional probability that an occurrence of event type A is followed by an occurrence of event type B within time no later than w. This is defined as: (number of windows containing both A and B)/(the number of windows containing A).
[0064] χ AB 2 is the chi-squared test score of the A-B coupling which indicates the deviation of A's and B's distribution from a random distribution. A high χ AB 2 score indicates it is likely that the two events happen non-randomly, or have some relationship but do not occur together by accident.
[0065] The χ AB 2 test score is defined through the following statistics. The probability of observing an event A in a window is
P A = N A T
[0066] where T is the time covered in the log. The expected probability of finding both event A and event B in a window with event A occurring before event B is E(P AB )=P A +P B /2. The actual probability of finding both event A and event B in a window with event A occurring before event B is
P B | A = N A B 2 T
[0067] where N AB is the number of (A,B) event pairs. The variance of co-occurrences of event A and event B is defined as
V A R A B = P A B ( 1 - P A B ) T .
[0068] The χ AB 2 test score is defined as:
χ A B 2 = ( P B | A - E ( P A B ) ) 2 V A R A B .
[0069] Thresholds of the link confidence are also in the form of a triple <N t ,P t ,χ 2 t > such that a link (A,B) is valid if N A ≧N t , P AB ≧P t and χ 2 AB ≧χ 2 t . Note that it is possible that both links (A,B) and (B,A) are valid. In such cases, the direction of link (A,B) should be from A to B if P B|A ≧P A|B , otherwise, the direction should be from B to A.
[0070] Thus, the confidence of a link represents the likelihood that the two events linked are emitted together and in that order. In accordance with the two correlation semantics of the present invention, an ERN is valid in weak correlation if all links have confidences higher than a given threshold. An ERN is valid in strong correlation if the link confidence between any node and all its transitive successors (e.g., successor of successor, successor of successor of successor, etc.) are valid in the ERN.
[0071] Referring now to FIG. 4, a diagram is presented for use in illustrating an incorrect global correlation. As shown in FIG. 4, event A leads to a first event B, and a second event B leads to an event C. Thus, while a link between A and the first event B may be valid and a link between the second event B and C may be valid, a link of A to B to C may not be valid. But if there is a low correlation threshold set, then the first B event could still be correlated to event C. Thus, the sum of pairwise correlation does not necessarily show the whole picture, especially when the given threshold is low.
[0072] More particularly, suppose in this example that the given threshold of conditional probability is 40%. Assume that link (A,B) and (B,C) both have confidences higher than 40%. Then, this ERN is valid in a weak correlation semantic. As stated above, an ERN is valid in weak correlation if all links have confidences higher than a given threshold. But a further investigation may show that link (A,C) has very weak correlation such that it should not be placed in the same ERN. This is a motivating force for introducing the notion of strong correlation, as defined above.
[0073] [0073]FIGS. 5 and 6 are diagrams illustrating the concept of ERN stratification according to an embodiment of the present invention. For weak correlation, the main task is to stratify ERNs so the path between any two nodes, if it exists, is unique. The purpose of ERN stratification is to eliminate any link between two nodes that have longer paths between them. In the case shown in FIG. 5, there is more than one path from A to C, namely, A to B to C, and A to C directly. The path from A to B to C is a longer path than the direct path between A and C. Thus, according to the notion of stratification, the link from A to C should be eliminated. The resulting ERN is shown in FIG. 6.
[0074] In cases where there is more than one longest path, we eliminate the one with the weakest link. The weakest link is the link with the smallest conditional probability. In the cases where the links form a cycle, the weakest link is eliminated.
[0075] [0075]FIG. 7 is a diagram illustrating the concept of ERN validation according to an embodiment of the present invention. ERNs constructed in different installations or at different times may be used as starter sets for generating correlation rules. The task is to validate whether the correlation specified in the existing ERNs is valid in the environment of interest. The validation of weak correlation is straightforward. Users specify the window length w and the event log file. Then, an ERN validation, completion and construction (VCC) system, as will be illustrated and explained below, annotates the nodes and links. A preferred annotation format is illustrated in accordance with FIG. 7.
[0076] More particularly, FIG. 7 shows a simple ERN with three nodes (event types) annotated by statistics obtained from an event log of 90 days with specified window size 60 seconds. The count of an event types is placed near the corresponding node, e.g., Cisco_Link_Down has 1014 occurrences. Each link is annotated with two pairs of probabilities and χ 2 score, namely, (P B|A, χ 2 AB ) and (P A51 B , χ 2 BA ). For example, the link from Cisco_Link Up to Cisco_Link_Down has conditional probability 0.18 and χ 2 score 278. The reverse link has conditional probability 0.23 and χ 2 score 54. These statistics can be interpreted in the following way. The forward conditional probability, 0.18, is smaller than the backward conditional probability. Usually, this means the direction of the link should be reversed. However, Cisco_Link_Up is a clearing event. The link direction should remain unless the forward confidence is smaller than the threshold. Although the conditional probabilities do not look significant at first glance, the χ 2 scores, however, indicate otherwise. Consider a log history containing 129,600 non-overlapping windows, then conditional probabilities 0.18 and 0.23 are actually very high. This fact is indicated by the χ 2 scores which imply the two events are correlated with more than 99% confidence. The risk of missing the link (A,B) can be calculated as 1014*0.23=242. Also, it is very clear that Cisco_Cold_Start should not be included in this ERN because both the conditional probabilities and χ 2 scores are 0.
[0077] With respect to the validation of the two correlation semantics of the invention, it is to be appreciated that validation of strong correlation is comparatively more complicated than validating weak correlation. Thus, validation of strong correlation contains the following three steps:
[0078] 1. Split the ERN into correlation paths. For every source node (i.e., nodes with no incoming link) find paths to every reachable sink node (i.e., nodes with no outgoing link).
[0079] 2. For every correlation path, remove the node that has the least number of correlated nodes, upstream or downstream, until every node has full correlation with every other node.
[0080] 3. Merge correlation paths to ERNs with a constraint that every path in the resulting ERN is a valid path in step 2.
[0081] As implied by the definition of strong correlation, an ERN might be split to several ERNs after strong correlation validation.
[0082] [0082]FIG. 8 is a diagram illustrating a process of validating an ERN by an event log according to an embodiment of the present invention. More particularly, FIG. 8 illustrates an annotated ERN of a higher complexity than the annotated ERN shown in FIG. 7. As is evident, in the validation process, pairwise correlation statistics are annotated on links for domain experts to determine how to modify the ERNs. The annotated ERN in FIG. 8 shows some relationships that may be contrary to intuition. For example, “Minor Alarms” do not correlate to “Major Alarms” on both PS 1 and PS 2 . Also, clearing events “chassisMinorAlarm” and “Cisco —Cold _Start” do not actually clear alarm events.
[0083] [0083]FIG. 9 is a diagram illustrating a process of completing and constructing an ERN according to an embodiment of the present invention. For a given ERN, the validation method described above can identify incorrect links. But identifying missing nodes and links from ERNs requires searching all event types to find those correlated event types already in ERNs. This completion process is done in an iterative manner. In each iteration, all event types correlated to any event type in current ERNs are attached with corresponding links. The process proceeds until no more event types can be added.
[0084] Even a very simple completion procedure can be very helpful to ERN designers. In this case, we take an event type, chassisMajorAlarmPS 2 as denoted as block 90 in FIG. 900, from a real production environment, which does not seem to be correlated to other event types in existing ERNs. However, by computing its correlation (as described above) with all event types shown in an event log, we found there are 22 event types (denoted as blocks 902 through 944 in FIG. 9) that show strong pairwise correlation with the event type. Among the 22 event types, 15 event types (blocks 902 through 920 and blocks 934 through 942 ) are clearing events, one event type (block 944 ) tends to occur before the target event (block 900 ), and 6 event types (blocks 922 through 932 ) tend to occur after the target event.
[0085] In situations where no existing ERN can be used for a starter set, the ERN validation, completion and construction (VCC) system of the invention is responsible for generating ERNs for subject matter experts to review. ERN construction can be treated as a special case of ERN completion where no ERN is available. However, the corresponding computation is more expensive because the system has to start with computing all pairwise correlations instead of with only those containing at least one event in existing ERNs.
[0086] The ERN VCC system is designed to work closely with subject matter experts. We propose a data-driven design process. If there is an ERN starter set, the process starts by validating and completing the starter set. Otherwise, the system constructs an initial set of ERNs. Human experts can always modify machine-generated ERNs and put them back to the ERN VCC system for revalidation. A complete and correct set of ERNs can usually be obtained in a few iterations.
[0087] [0087]FIG. 10 is a block diagram illustrating an ERN VCC system according to an embodiment of the present invention. The system 1000 uses event logs 1002 in files or databases as input. The event miner component 1004 performs pairwise correlation on events with predefined threshold parameters 1006 (e.g., Dialog boxes, XML). The output of the event miner module is patterns 1008 in XML format. A default XSL (XML style sheet) file 1010 is provided along with the patterns to diagram construction module 1012 , which is a set of Visio VBA scripts (e.g., glue, transform interact). Existing ERNs 1014 , if available, are taken in at this point for validation. Validated or constructed ERNs 1016 are the final output of the system.
[0088] [0088]FIG. 11 is a diagram illustrating an ERN validation, completion and construction process according to an embodiment of the present invention. It is to be appreciated that the validation, completion and construction process of ERNs is an iterative process, with both automatic statistical analysis (e.g., pairwise correlation) and domain experts review. This process is illustrated in more detail in FIG. 11.
[0089] As shown, the ERN VCC process 1100 takes event data 1102 as input and, in step 1104 , throttles the event data, as previously described, to remove redundancies in the event data. Assuming an ERN starter set 1105 exits, an ERN validation/completion process 1106 is performed on the event data. Assuming no ERN starter set 1105 exits, an ERN construction process 1108 is performed on the event data. Such automated statistical analysis processes yield one or more verified ERNs 1110 . Domain experts review the output ERNs in block 1112 and determine the final ERNs. If they are not satisfied with the automatically generated ERNs, the domain experts instruct the system to repeat the process. If they are satisfied, the ERNs are used to construct correlation rules 1114 , as is known. Thus, as explained above, the operational purpose of constructing ERNs is to instruct correlation engines, in accordance with the constructed correlation rules, a proper way to process events.
[0090] Referring now to FIG. 12, a block diagram is shown illustrating a generalized hardware architecture of a computer system suitable for implementing the various functional components/modules of an ERN VCC system as depicted in the figures and explained in detail herein. It is to be understood that the individual components of the ERN VCC system may be implemented on one such computer system, or on more than one separate such computer system. Also, individual components of the system may be implemented on separate such computer systems. It is also to be appreciated that the correlation server components (of FIG. 2) may be implemented on one or more such computer systems.
[0091] As shown, the computer system may be implemented in accordance with a processor 1202 , a memory 1204 and I/O devices 1206 . It is to be appreciated that the term “processor” as used herein is intended to include any processing device, such as, for example, one that includes a CPU (central processing unit) and/or other processing circuitry. The term “memory” as used herein is intended to include memory associated with a processor or CPU, such as, for example, RAM, ROM, a fixed memory device (e.g., hard drive), a removable memory device (e.g., diskette), flash memory, etc. In addition, the term “input/output devices” or “I/O devices” as used herein is intended to include, for example, one or more input devices (e.g., keyboard, mouse, etc.) for entering data to the processing unit, and/or one or more output devices (e.g., CRT display, printer, etc.) for presenting results associated with the processing unit. For example, user interfaces of the system employed by a domain expert (e.g., to review ERNs, specify event logs, etc.) may be realized through such I/O devices. It is also to be understood that the term “processor” may refer to more than one processing device and that various elements associated with a processing device may be shared by other processing devices.
[0092] Accordingly, software components including instructions or code for performing the methodologies of the invention, as described herein, may be stored in one or more of the associated memory devices (e.g., ROM, fixed or removable memory) as an article of manufacture and, when ready to be utilized, loaded in part or in whole (e.g., into RAM) and executed by a CPU.
[0093] It is to be appreciated that the rule validation, completion and construction techniques described herein may be employed in accordance with the off-line event management decision support system described in the U.S. patent application identified by attorney docket no. YOR920010746US1 filed concurrently herewith and entitled: “Systems and Methods for Providing Off-Line Decision Support for Correlation Analysis,” the disclosure of which is incorporated by reference herein.
[0094] Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. | Techniques for data-driven validation, completion and construction of event relationship networks (ERNs) are provided. Event relationship networks are widely used in event management system design. To date, ERNs are constructed purely based on human expertise and there is no automatic or event semi-automatic method that validates or completes ERNs. The present invention provides techniques for automatically validating and completing existing ERNs and/or constructing new ERNs, based on collected event data. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a method of heat treating polybenzazole fibers in order to improve the physical properties of the fibers.
Polybenzazole fibers, such as polybenzoxazole fibers, are expected to be the super fibers of the next generation because they can have a modulus two or more times higher than the modulus of poly-p-phenyleneterephthalamide fiber which is representative of super fibers on the market now.
The best modulus for polybenzazole fiber is not obtained unless the fiber is heat-treated. Conventional heat treatment methods are described in J. Mater. Sci., 20, 2727(1985) and H. D. Ledbetter, S. Rosenberg, C. W. Hurtig, Symposium Proceedings of The Materials Science and Engineering of Rigid-Rod Polymers, Vol. 134, 253 (1989). These conventional heat treatment processes for polybenzazole fibers must be conducted at temperatures of 500° C. or more since the rigidity of the polybenzazole molecule is very high. Conventional fiber heat-treating equipment tends to be expensive, and the amount of time required can lead to heat treating becoming the bottle neck of industrial fiber production.
Heat treating is required in order to improve the modulus of polybenzazole fibers. This invention provides a new method of heat treatment which eliminates the necessity for prolonged high temperature heat treatment of polybenzazole fibers. Polybenzazole (IIPBZII) fibers include fibers made of polybenzoxazole ("PBO") or polybenzothiazole ("PBT").
SUMMARY OF THE INVENTION
One aspect of the invention is a method to heat treat a polybenzazole fiber by contacting the polybenzazole fiber under tension in a heat treating zone with a heating medium heating gas, characterized in that the heating medium heating gas is steam which moves through the heat treating zone in a cocurrent or countercurrent fashion relative to the fiber.
A second aspect of the invention is a method to heat treat a polybenzazole fiber by contacting the polybenzazole fiber under tension in a heat treating zone with steam which moves through the heat treating zone in a cocurrent or countercurrent fashion relative to the fiber at a velocity of at least about 5 m/sec.
A third aspect of the invention is a method to heat treat a polybenzazole fiber by contacting the polybenzazole fiber under tension in a heat treating zone with a heating medium heating gas, characterized in that the heating medium heating gas is steam which moves through the heat treating zone in a cocurrent or countercurrent fashion relative to the fiber at a velocity of at least about 5 m/sec. wherein the residence time of the fiber in the heat treating zone is no more than about 3 seconds.
DETAILED DESCRIPTION OF THE INVENTION
Polymers
The present invention uses shaped articles containing polybenzazole (polybenzoxazole and polybenzothiazole) polymers. Polybenzoxazole, polybenzothiazole and random, sequential and block copolymers of polybenzoxazole and polybenzothiazole are described in references such as Wolfe et al., Liquid Crystalline Polymer Compositions, Process and Products, U.S. Pat. No. 4,703,103 (Oct. 27, 1987); Wolfe et al., Liquid Crystalline Polymer Compositions, Process and Products, U.S. Pat. No. 4,533,692 (Aug. 6, 1985); Wolfe et al., Liquid Crystalline Poly(2,6-Benzothiazole) Compositions, Process and Products, U.S. Pat. No. 4,533,724 (Aug. 6, 1985); Wolfe, Liquid Crystalline Polymer Compositions, Process and Products, U.S. Pat. No. 4,533,693 (Aug. 6, 1985); Evers, Thermooxidatively Stable Articulated p-Benzobisoxazole and p-Benzobisthiazole Polymers, U.S. Pat. No. 4,359,567 (Nov. 16, 1982); Tsai et al., Method for Making Heterocyclic Block Copolymer, U.S. Pat. No. 4,578,432 (Mar. 25, 1986); 11 Ency. Poly. Sci. & Eng., Polybenzothiazoles and Polybenzoxazoles, 601 (J. Wiley and Sons 1988) and W. W. Adams et al., The Materials Science and Engineering of Rigid-Rod Polymers (Materials Research society 1989), which are incorporated herein by reference.
The polymer may contain Ab-mer units, as represented in Formula 1(a), and/or AA/BB-mer units, as represented in Formula 1(b) ##STR1## wherein: Each Ar represents an aromatic group. The aromatic group may be heterocyclic, such as a pyridinylene group, but it is preferably carbocyclic. The aromatic group may be a fused or unfused polycyclic system, but is preferably a single six-membered ring. Size is not critical, but the aromatic group preferably contains no more than about 18 carbon atoms, more preferably no more than about 12 carbon atoms and most preferably no more than about 6 carbon atoms. Examples of suitable aromatic groups include phenylene moieties, tolylene moieties, biphenylene moieties and bisphenylene ether moieties. Ar 1 in AA/BB-mer units is preferably a 1,2,4,5-phenylene moiety or an analog thereof. Ar in AB-mer units is preferably a 1,3,4-phenylene moiety or an analog thereof.
Each Z is independently an oxygen or a sulfur atom.
Each DM is independently a bond or a divalent organic moiety that does not interfere with the synthesis, fabrication or use of the polymer. The divalent organic moiety may contain an aliphatic group, which preferably has no more than about 12 carbon atoms, but the divalent organic moiety is preferably an aromatic group (Ar) as previously described. It is most preferably a 1,4-phenylene moiety or an analog thereof.
The nitrogen atom and the Z moiety in each azole ring are bonded to adjacent carbon atoms in the aromatic group, such that a five-membered azole ring fused with the aromatic group is formed.
The azole rings in AA/BB-mer units may be in cis- or transposition with respect to each other, as illustrated in 11 Ency. Poly. Sci. & Eng., supra, at 602, which is incorporated herein by reference.
The polymer preferably consists essentially of either AB-polybenzazole mer units or AA/BB-polybenzazole mer units, and more preferably consists essentially of AA/BB-polybenzazole mer units. The molecular structure of the polybenzazole polymer may be rigid rod, semi-rigid rod or flexible coil. It is preferably rigid rod in the case of an AA/BB-polybenzazole polymer or semi-rigid in the case of an AB-polybenzazole polymer. Azole rings within the polymer are preferably oxazole rings (Z =0). Units within the polybenzazole polymer are preferably chosen so that the polymer is lyotropic liquid-crystalline, which means it forms liquid-crystalline domains in solution when its concentration exceeds a "critical concentration point". Preferred mer units are illustrated in Formulae 2 (a)-(h). The polymer more preferably consists essentially of mer units selected from those illustrated in 2(a)-(h), and most preferably consists essentially of a number of identical units selected from those illustrated in 2(a)-(c). ##STR2##
Each polymer preferably contains on average at least about 25 mer units, more preferably at least about 50 mer units and most preferably at least about 100 mer units. The intrinsic viscosity of lyotropic liquid-crystalline AA/BB-polybenzazole polymers (as estimated by a single-point method in methanesulfonic acid at 25° C.) is preferably at least about 10 deciliters/gram ("dL/g"), more preferably at least about 15 dL/g, and most preferably at least about 20 dL/g. For some purposes, an intrinsic viscosity of at least about 25 dL/g or 30 dL/g may be best. Intrinsic viscosity of 60 dL/g or higher is possible, but the intrinsic viscosity is preferably no more than about 45 dL/g. The intrinsic viscosity is most preferably about 33 dL/g. The intrinsic viscosity of lyotropic liquid-crystalline semi-rigid AB-polybenzazole polymers is preferably at least about 5 dL/g, more preferably at least about 10 dL/g and most preferably at least about 15 dL/g.
The polymer is fabricated into fibers and films by spinning or extruding from a dope. A dope is a solution of polymer in a solvent. If freshly made polymer or copolymer is not available for spinning or extruding, then previously made polymer or copolymer can be dissolved in a solvent to form a solution or dope. Some polybenzoxazole and polybenzothiazole polymers are soluble in cresol, but the solvent is preferably an acid capable of dissolving the polymer. The acid is preferably non-oxidizing. Examples of suitable acids include polyphosphoric acid, methanesulfonic acid and sulfuric acid and mixtures of those acids. The acid is preferably polyphosphoric acid and/or methanesulfonic acid, and is more preferably polyphosphoric acid.
The dope should contain a high enough concentration of polymer for the polymer to coagulate to form a solid article but not such a high concentration that the viscosity of the dope is unmanageable to handle. When the polymer is rigid or semi-rigid, then the concentration of polymer in the dope is preferably high enough to provide a liquid crystalline dope. The concentration of the polymer is preferably at least about 7 weight percent, more preferably at least about 10 weight percent and most preferably at least about 14 weight percent. The maximum concentration is limited primarily by practical factors, such as polymer solubility and, as already described, dope viscosity. Because of these limiting factors, the concentration of polymer is seldom more than 30 weight percent, and usually no more than about 20 weight percent.
Suitable polymers or copolymers and dopes can be synthesized by known procedures, such as those described in Wolfe et al., U.S. Pat. No. 4,533,693 (Aug. 6, 1985); Sybert et al., U.S. Pat. No. 4,772,678 (Sep. 20, 1988); Harris, U.S. Pat. No. 4,847,350 (Jul. 11, 1989); and Ledbetter et al., "An Integrated Laboratory Process for Preparing Rigid Rod Fibers from the Monomers," The Materials Science and Engineering of Rigid-Rod Polymers at 253-64 (Materials Res. Soc. 1989,), which are incorporated herein by reference. In summary, suitable monomers (AA-monomers and BB-monomers or AB-monomers) are reacted in a solution of nonoxidizing and dehydrating acid under nonoxidizing atmosphere with vigorous mixing and high shear at a temperature that is increased in step-wise or ramped fashion from a starting temperature of no more than about 120° C. to a final temperature of at least about 190° C. Examples of suitable AA-monomers include terephthalic acid and analogs thereof. Examples of suitable BB-monomers include 4,6-diaminoresoreinol, 2,5-diaminohydroquinone, 2,5-diamino-1,4-dithiobenzene and analogs thereof, typically stored as acid salts. Examples of suitable AB-monomers include 3-amino-4-hydroxybenzoic acid, 3-hydroxy-4-aminobenzoic acid, 3-amino-4-thiobenzoic acid, 3-thio-4-aminobenzoic acid and analogs thereof, typically stored as acid salts.
Preparation of PBO "Dope"
A PBZ dope is a solution of PBZ polymer in a solvent. Polybenzoxazole polymer is only soluble in very highly protic acid solvents such as methane sulfonic acid or polyphosphoric acid. A preferred solvent is polyphosphoric acid (IIPPAII). The preferred concentration of PBO in the polyphosphoric acid is about 14 weight percent. The intrinsic viscosity of the PBO/PPA polymer dope should be in the range of 22 to 45 dL/g (based on measuring in a methane-sulfonic acid solution at 25° C. and a 0.05g/dL concentration) .
Preparation of Polybenzazole Fibers
These polybenzazole fibers are preferably made employing a so-called coupled process of polymerization and spinning, in which polybenzazole dope from the polymerization is supplied directly to a spinning part which includes orifices, without taking the spinning dope from the polymerization reaction equipment, although one may perform dry-spinneret-wet spinning type process separately, after taking the dope from the polymerization equipment.
In a dry-jet-wet-spinning process the dope is extruded from the orifices of the spinneret. The pattern of orifices on the spinneret can be in the shape of a circle or a lattice. The number of orifices and the arrangement of orifices in a spinneret needs to be selected to ensure that the dope fibers exiting the spinneret do not stick or fuse to each other. It is important to equalize the temperature of all the fibers exiting the spinneret because a difference in temperature among fibers of a fiber bundle is reflected in spinning tension difference immediately. (See copending, same-day filed U.S. Patent Application "Method for Rapid Spinning of a Polybenzazole Fiber" which is assigned to the same entity as this application and which is incorporated by reference.)
After exiting the orifices on the spinneret the dope fibers enter an "air gap". The gas in the "air gap" may be air, but it may also be another gas such as nitrogen, carbon dioxide, helium or argon. The temperature in the air gap is preferably between about 0° C. and 150° C., more preferably between about O° C. and 100° C. and most preferably between 50° C. and 100° C. After traveling through the air gap, the extruded dope fibers are contacted with a fluid known as a coagulant to separate the solvent from the polybenzazole polymer.
The coagulant can be in a bath or it can be sprayed onto the fibers. If a liquid medium coagulation bath is used it should be installed downward of the spinneret. The extraction of solvent at a level of more than 99.0 percent and more preferably of more than 99.5 percent is accomplished in this liquid medium coagulation bath. Any coagulation bath/spray used can contain water or water/acid mixtures, with the preferred acid being phosphoric acid at a concentration of 30 percent or less. Other coagulants for the fiber include organic solvents such as acetone, methanol or acetonitrile. Any kind of liquid medium coagulation bath system can be used, for example, very common solidification baths have a roller inside, or the funnel type bath mentioned in Japan laid open patent No. 51-35716, or the Japanese Patent Publication No. 44-22204, or the coagulation bath with high speed aspirator mentioned in U.S. Pat. No. 4,298,565 or waterfall type coagulation bath mentioned in U.S. Pat. No. 4,869,860.
The solvent concentration in the coagulated fiber decreases further by the washing of the fiber using a washing liquid. As before, any washing bath/spray used can contain water or dilute water/acid mixtures, with the preferred acid being phosphoric acid at a concentration of 5 percent or less. Other washing liquids for the fiber can include organic solvents such as acetone, methanol or acetonitrile.
After being coagulated and washed the fiber is dried and taken up on storage rolls. The fiber obtained in this way has sufficient tenacity and sufficient modulus for an as-spun fiber, but the modulus of this polybenzazole fiber can be improved dramatically by subsequent heat-treatment.
The heat treatment process can be conducted separately or continuously. Typical heat treatment apparati have the appearance of narrow tubes or rectangles with a means to deliver and take-up the fiber as it enters and exits the heat treatment apparatus. The heat treatment apparatus must also have a means for delivering a directed flow of heating medium heating gas relative to the fiber. The means to deliver a directed flow of heating medium heating gas to the fiber could provide a cocurrent directed flow of heating medium heating gas or a countercurrent directed flow of heating medium heating gas relative to the fiber.
It is also possible to have both countercurrent and cocurrent flow in a heat treatment apparatus, by having a delivery system in the center of the apparatus with this delivery system having two nozzles which can supply the heating medium heating gas simultaneously in both a cocurrent (with the fiber) direction and a countercurrent (against the fiber) direction.
High velocity and high temperature gas, such as steam, nitrogen or other inert gases, can be used as the heating medium heating gas for a heat treatment process in order to increase the imodulus of polybenzazole asspun fiber. The area in the heat treating apparatus where the fiber is in contact with the heating medium heating gas is referred to as the "heat treating zone". The velocity of the heating medium heating gas should be higher than at least 5 m/sec and preferably higher than 10 m/sec, because heat exchange efficiency between fibers and heating gas i3 determined by the velocity difference between fiber and gas as explained in the following equation.
ΔTαL.sup.0.8 ·u.sup.0.8 ·t·(Ts-Tf)
where L is length of heater or heat treating zone, u is velocity difference between fibers and gas, t is residence time of heater, Ts is temperature of gas and Tf is temperature of fibers before heater.
In order to enhance the heat exchange between the heating medium heating gas and the fiber, it is important that the heating medium heating gas be impelled into the heat treatment apparatus such that the flow of heating medium heating gas is directed at the fiber in either a cocurrent or countercurrent manner. With either cocurrent or countercurrent flow, there will be a velocity difference between the fiber and the heating medium heating gas with such velocity difference aiding in heat transfer efficiency. Of course, the velocity difference will be greater for countercurrent flow than for cocurrent flow.
It is also possible to have both countercurrent and cocurrent flow in a heat treatment device, by having a delivery system in the center of the device with this delivery system supplying the heating medium heating gas in both a cocurrent (with the fiber) direction and a countercurrent (against the fiber) direction.
The speed of the fibers through the heat treating zone is preferably at least about 20 re/min. and more preferably at least about 40 re/min. The velocity of the gas is preferably at least 5 m/sec. and most preferably at least 10 m/sec. The velocity difference between the fibers and the gas is preferably at least 5 m/sec and more preferably at least 10 m/sec. The gas flow rate is measured by a flow meter as mass in kg/hr. For a heat treatment apparatus which has both cocurrent and countercurrent flow of heating medium heating gas, the gas velocity is converted from flow rate by the following equation:
v=Q/d/60.sup.2 /2S
where v is velocity in m/see, Q is mass flow rate in kg/hour, d is density of steam, and S is cross sectional area of steam heater in square meters. The residence time of the fibers in the heating zone is preferably at most 20 sec., more preferably at most 5 sec. and most preferably at most about 3 sec. The tension on the fibers is preferably between 0.1 and 10 g/den, although it may be more or less.
Through the instantaneous increase of temperature of fiber by the use of a high velocity and high temperature gas heating medium, such as steam, the negative heat set effect during heat treatment can be reduced and as a result this improved heat treatment process can decrease the conventional temperature required (usually 600 degrees C) and the conventional residence time required (more than 10 seconds) . By using a cocurrent flow of a high velocity and high temperature gas in the heat treatment apparatus, the temperature required for heat treatment can be reduced down to 400° C. and the residence time for the fiber in the heat treatment process can be shortened to less than 3 seconds. The tensile modulus of the fibers heat treated by this method is preferably at least 220 GPa (31.9 msi) and more preferably at least about 250 GPa (36.3 msi).
The following examples are given as specific illustrations of the invention. It should be understood, however, that the invention is not limited to the specifics set forth in the examples.
EXAMPLE 1
A polybenzoxazole polymer dope (approximately 14 weight percent polymer) is created. Once created, this polymer dope is transferred through a wire mesh filter to a twin screw extruder in order to mix and degas. Then the spinning dope is extruded from a spinneret which has 334 orifices of 0.20 mm in diameter at 150 degrees C. Throughput of dope per orifice is 0.22 g/min. The extruded fibers are coagulated in a funnel type water coagulation bath which is 20 em below the spinneret. The atmosphere in the twenty cm gap between the spinneret and the coagulation bath is dry air. The coagulated fibers are taken up at 200 re/min velocity. The coagulated fibers are then washed and dried. The dried fibers had 0.4 weight percent of moisture content, approximately 1110 g/d of modulus, 38.6 g/d of tenacity and 9.8 percent of elongation at break.
The dried fibers are heat treated under the specifications mentioned in Table 1. In the table, SJ stands for "Steam Jet", resid. is the residence time of the fiber in the heat treatment apparatus, GR1 is the feed roll and GR2 is the take-up roll.
TABLE 1__________________________________________________________________________Heat-Treated With Steam Jet Conv. SJ SJ E atSample Heater Temp. Velocity GR1 GR2 Elong. Resid. Den. Tena. Brake Mod# C C m/sec m/min m/min % sec Stability d g/d % g/d.__________________________________________________________________________AS-SPUN -- -- -- -- -- -- -- -- 206.8 38.6 3.8 1110Ref. 1 350 none -- 10.03 10.13 1.00 20.0 Good 207.0 38.1 3.5 1158Ref. 2 450 none -- 10.03 10.13 1.00 20.0 Good 206.3 36.6 2.9 1486Ref. 3 550 none -- 10.03 10.13 1.00 20.0 Good 205.8 34.8 2.5 1653Ref. 4 650 none -- 10.03 10.13 1.00 20.0 Good 206.0 36.1 2 1857Ref. 5 600 none -- 20.05 20.25 1.00 10.0 Good 205.4 36.5 2.9 1750Ref. 6 600 none -- 50.06 50.13 1.00 4.0 Good 205.3 35.7 3.1 1642Ref. 7 600 none -- 100 101 1.00 2.0 Good 206.5 37.2 3.1 1350 1 none 440 100 290 293 1.02 0.2 Good 206.9 36.7 2.8 1674 2 none 440 100 290 294 1.30 0.2 Good 207.5 37.6 2.7 1694 3 none 470 100 199 202 1.45 0.3 Good 199.7 38.0 2.3 1838 4 none 440 100 151 153 1.07 0.4 Good 205.0 33.3 2.2 1859 5 none 470 100 151 153 1.35 0.4 Good 207.2 36.5 2.3 1809 6 none 475 100 20.05 20.25 1.00 2.8 Good 205.3 33.0 2.0 1908 7 none 440 100 20.05 20.47 2.09 2.8 Poor* 199.0 30.8 1.8 1888 8 none 440 100 20.05 20.40 1.75 2.8 Good 206.1 32.9 1.9 1963 9 none 440 100 20.05 20.23 0.90 2.8 Good 204.7 32.5 2.1 183110 none 440 100 20.05 20.32 1.35 2.8 Good 203.4 35.4 2.1 193711 none 390 100 20.00 20.10 0.50 2.8 Good 205.0 33.3 2.2 185912 none 390 100 20.00 20.20 1.00 2.8 Good 209.0 34.7 2.0 192513 none 366 100 20.10 20.23 0.65 2.8 Good 204.0 34.5 2.6 175914 none 366 100 20.10 20.35 1.24 2.8 Good 206.7 34.3 2.2 182615 none 340 100 20.10 20.30 1.00 2.8 Good 207.3 34.3 2.4 175716 none 340 100 20.10 20.38 1.39 2.8 Good 205.1 35.3 2.3 179817 none 320 100 20.10 20.39 1.44 2.8 Good 206.2 35.1 2.4 175618 none 320 100 20.10 20.28 0.90 2.8 Good 205.9 35.8 2.7 166619 none 300 100 20.10 20.33 1.14 2.8 Good 207.2 36.9 2.8 166420 none 300 100 20.10 20.43 1.64 2.8 Good 204.6 37.3 2.6 177521 none 410 100 44.25 44.80 1.24 1.3 Good 203.8 34.8 2.3 183822 none 410 100 44.18 44.80 1.41 1.3 Good 205.2 35.5 2.2 184523 none 410 100 44.03 44.45 0.95 1.3 Good 203.6 34.4 2.5 170124 none 460 10 44.03 44.45 0.95 1.3 Good 205.3 36.1 2.5 1654Ref. 8 none 410 5 44.03 44.45 0.95 1.3 Good 207.9 35.5 3.1 1320Ref. 9 none 410 1 44.03 44.45 0.95 1.3 Good 208.0 37.6 3.5 114925 none 460 100 20.14 20.34 0.99 2.8 Good 207.5 36.6 2.3 186026 none 460 100 20.14 20.49 1.44 2.8 Good 202.1 36.3 2.1 1972__________________________________________________________________________ *Fiber Broke and was fuzzy
In the case where the heating medium heating gas is steam, the sufficiently effective temperature is only 370 degrees C., as compared to the 600 degrees C. needed for conventional heat treatment. Further advantage for industrial manufacturing is that the line velocity of heat treatment can increase to higher than 200 re/min as compared with a line velocity of approximately 20m/min using conventional means of heat treatment..
The measurement methods of physical-properties used for evaluation of this invention are as follows.
Limiting Viscosity Number
The limiting viscosity number of polybenzbisoxazole polymers is measured by the zero extrapolation of the reduction viscosity measured at 30 degrees C. using methanesulfonic acid as a solvent.
Denier of Fiber
Samples of fiber are measured after being conditioned for 16 hours at 22 degrees C. and RH of 65+-2. Single fiber denier are measured by Denier Computer DC-I 1B type made by Search Co., Ltd. Fiber denier is measured by the wrap reel method according to JIS L-1013 (1981).
Tensile Properties of Fibers
Measurement are performed according to JIS L-1013 (198 1). Both a single fiber and a yarn are measured. | This invention aims at improvement of heat-treatment technology for manufacture of large amounts of polybenzazole fibers. The fibers are heat treated using steam as the heat treatment gas in a device that provides for a rapid, cocurrent, countercurrent or both cocurrent and countercurrent flow of steam. | 3 |
This application is a continuation-in-part of U.S. non-provisional application Ser. No. 13/622,398 filed on Sep. 19, 2012 which is included herein in its entirety by reference.
COPYRIGHT NOTICE
A portion of the disclosure of this patent contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to devices for protecting shoes. In particular, the present invention relates to a method for protecting the raised heel of a woman's high heel shoe.
2. Description of Related Art
Women's high heel shoes are typically designed for dress-up occasions. They are designed to add height to a woman's stature as well as accent the musculature of the leg. While high heels have become thicker and flatter, the typical stiletto type high heel is still very popular as are other types of high heels. One problem that occurs when wearing stiletto heels or other such heels is the ease with which the heel portion of the shoe can become damaged. While the very bottom of the heel is replaceable, the upper portion that is normally colored is affixed to the shoe and is for the most part not replaceable without great cost if at all.
Damage to the upper portion of a high heel is very noticeable and can cause the shoe to be unwearable from a fashion standpoint. Very little has been available to address this problem which has been around as long as there have been high heels. One attempt is shown in German patent DE 10 2009 051 289 A1 to Vera Zwiauer. In this attempt, a rectangular piece of material is wrapped around the lower portion of the upper heel. However, since a heel is not perfectly cylindrical and is tapered, the material bunches up in spots and must be overlapped causing a visible bulge when mounted. To date, this device has not seen any commercial use most likely because of fit problems as well as poor decorative look.
BRIEF SUMMARY OF THE INVENTION
The present invention involves the discovery that a tapered clear plastic material that is adjustable in size, e.g. by tearable perforations, allows the user to adjust a covering for the lower portion of the upper high heel in a manner that is barely visible during use and avoids fit problems.
Accordingly, in one embodiment of the invention, there is disclosed a device for protecting the lower portion of a woman's tapered stiletto or high heel of a given diameter and taper above the replaceable heel portion comprising a piece of clear film having a lower portion of an essentially trapezoidal shape of a fixed height and width wherein the device is adjustable in width and taper to fit the diameter and taper of the heel and an upper tapered portion wherein the height of the tapered portion is adjustable and wherein there is an adhesive film on one side of the device for adhering the device to the tapered heel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a frontal view of the device of the present invention.
FIGS. 2 a , 2 b and 2 c are a perspective view of the device wrapping around a stiletto heel.
FIG. 3 is a perspective view of the device mounted on a stiletto heel.
FIG. 4 is a frontal view of an alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
While this invention is susceptible to embodiment in many different forms, there is shown in the drawings and will herein be described in detail specific embodiments, with the understanding that the present disclosure of such embodiments is to be considered as an example of the principles and not intended to limit the invention to the specific embodiments shown and described. In the description below, like reference numerals are used to describe the same, similar or corresponding parts in the several views of the drawings. This detailed description defines the meaning of the terms used herein and specifically describes embodiments in order for those skilled in the art to practice the invention.
The terms “about” and “essentially” mean±10 percent.
The term “comprising” is not intended to limit inventions to only claiming the present invention with such comprising language. Any invention using the term comprising could be separated into one or more claims using “consisting” or “consisting of” claim language and is so intended.
The terms “a” or “an”, as used herein, are defined as one or as more than one. The term “plurality”, as used herein, is defined as two or as more than two. The term “another”, as used herein, is defined as at least a second or more. The terms “including” and/or “having”, as used herein, are defined as comprising (i.e., open language). The term “coupled”, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.
Reference throughout this document to “one embodiment”, “certain embodiments”, and “an embodiment” or similar terms means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of such phrases or in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments without limitation.
The term “or” as used herein is to be interpreted as an inclusive or meaning any one or any combination. Therefore, “A, B or C” means any of the following: “A; B; C; A and B; A and C; B and C; A, B and C”. An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive.
The drawings featured in the figures are for the purpose of illustrating certain convenient embodiments of the present invention, and are not to be considered as limitation thereto. Term “means” preceding a present participle of an operation indicates a desired function for which there is one or more embodiments, i.e., one or more methods, devices, or apparatuses for achieving the desired function and that one skilled in the art could select from these or their equivalent in view of the disclosure herein and use of the term “means” is not intended to be limiting.
As used herein the term “woman's stiletto” or “high heel” is the standard tapered woman's shoe heel as depicted in the figures and well known in the art. It is the generally non-replaceable part of the shoe heel. While a variety of different diameters and tapering exist (which has created the problem solved herein) the general style of heel is shown and well known. As used herein, the “lower portion of the stiletto or high heel” is the very bottom portion of the heel just above the replaceable heel (heel cap or heel tip) which is usually some sort of leather, rubber, or plastic portion that is worn down during walking and can be easily replaced by a cobbler. The upper portion of the heel is where the heel is attached to the rest of the shoe. The heel is essentially permanently attached to the shoe and is generally not replaceable. For purposes of this invention, the non-replaceable heel will have a lower portion that extends from the replaceable heel portion upwards to a desired height, such as ¾, half or a quarter, up the entire heel as necessary. The heel will have a diameter that varies depending on the distance from the replaceable heel but generally tapered as well. The problem being solved by the present invention is in part dealing with this variable diameter and taper of the heel and still making the device unobtrusive and effective.
As used herein the term “clear plastic film” refers to a polymer film that is see tough and flexible enough to wrap around the stiletto heel in use. Examples of polymers suitable for the present invention include polyurethane but based on this disclosure, others are taught. The polymer has an adhesive backing. The adhesive is one that is compatible with the polymeric film and sticks to the material the outer surface of the heel is made of so for example it may need to be compatible with leather, plastic coatings or the like. As an example silicone adhesive could be used. Other adhesives could be used or found with little experimentation based on the disclosure herein.
The polymeric film will have a lower portion of an essentially trapezoid shape (including a rectangle shape) having a fixed height and width or tapered width in a manner to match the stiletto or high heel shape (tapered heel). Generally the width of the present invention will be greater than the height but may change depending on the exact heel to be adapted. In order to be useful on a wide variety of heels, the straight or tapering sides have one or more adjustable features, for example, perforations which allow the width and taper to be adjusted to fit the circumference of the heel and taper of the heel and make a fit with little or no bulge. Perforations can be done in any convenient manner such as between about 2 perforations to about 12 perforations per inch. For example, perforations could be 0.07″ cut to 0.08″ cut and 0.01″ tear to 0.02″ tear. It will have an upper portion that is tapered and is adjustable in height. Again, adjustability can be by perforations which adjust the height of the upper portion.
The circumference of the heel is the distance around the heel as shown in the figures, however, a wide variety of heels could be produced for a variety of heels but all can be made adjustable within the scope of the present invention. In one embodiment, there is a non-adhesive backing to protect the adhesive backing until the film is applied to the heel of choice.
In applying the device of the present invention to a heel, the device's middle line is aligned with the center back of the heel and is positioned around the stiletto heel and portions of the side and top portion removed excess device until wrapping it around the heel matches the circumference and/or taper of the heel. Then the removable backing is removed and the device's side is placed against the heel (as shown in the figures), wrapped around the heel, and smoothed to remove any air bubbles and make sure it matches. In one embodiment, the seam created by the device is placed where it is least likely to be seen, that is facing the toe of the stiletto or high heel shoe.
Now referring to the figures, FIG. 1 is a frontal profile of the device of the present invention. Protective wrap 1 is shown having trapezoid bottom portion 10 having parallel top 3 and bottom 2 and parallel sides 4 and 5 . (This example depicts a rectangle but nonparallel sides are also contemplated.) The device has left side 7 and right side 6 which are tapering from the top side 3 to the bottom side 2 to form a trapezoidal shape when torn on 8 a . In order to adjust the width of the device 1 , diagonal perforations 8 a and 8 b are shown in the rectangular portion.
In FIG. 1 the device 1 has diagonal perforation 8 a being which can be torn to remove that piece and narrow the width as well as perforating for adjusting the height of lower portion 10 . It is clear there can be one or more perforations as desired to narrow the width of the device and the perforations can be angled as needed. One skilled in the art in view of this disclosure, could easily determine placement of perforations. Also shown is backing 9 which in this drawing is in the process of being pulled off the back side of device 1 which is being shown from the front side 15 . An adhesive would be on the back side.
FIG. 1 shows tapered upper portion 11 . The upper portion 11 is tapered from the lower portion 10 down to the rounded top 12 . Perforations 13 and 14 are also shown for adjusting height.
FIGS. 2 a , 2 b , and 2 c are a perspective series of the device 1 being wrapped around the lower portion of stiletto heel 23 on shoe 24 . Also shown is the replaceable heel cap 25 . While the wrapping is such that the seam will be to a side of the shoe 24 , in one embodiment, the seam is positioned to face shoe toe 26 (as shown in FIG. 3 ).
FIG. 3 shows a perspective of the device completely wrapped around heel 23 without seems or bulges. Notice that it is mounted on the lower portion of the heel 23 but any height of the heel can be chosen especially with the adjustable height feature. When in place, it protects the heel from scuffing or damage and can be removed and replaced with a new device easily and quickly.
FIG. 4 depicts another embodiment of the present invention. In this view the device 1 has additional vertical width adjusts perforations 20 and 21 which extend from the tapered portion 11 to the trapezoidal portion 10 . Also shown is notch 22 for making it easier to peel backing (not shown in this view) off of device 1 .
Those skilled in the art to which the present invention pertains may make modifications resulting in other embodiments employing principles of the present invention without departing from its spirit or characteristics, particularly upon considering the foregoing teachings. Accordingly, the described embodiments are to be considered in all respects only as illustrative, and not restrictive, and the scope of the present invention is, therefore, indicated by the appended claims rather than by the foregoing description or drawings. Consequently, while the present invention has been described with reference to particular embodiments, modifications of structure, sequence, materials and the like apparent to those skilled in the art still fall within the scope of the invention as claimed by the applicant. | A device for the protection of a high heel is disclosed which is adjustable to adapt to various shoe heel diameters and is barely visible during use. | 0 |
The invention relates to motorized wheelchairs and more particularly to an apparatus and method for attaching a motorized driven wheel to a manually-operated wheelchair.
BACKGROUND OF THE INVENTION
There are a variety of types of motorized wheelchairs which are known. These include three-wheel wheelchairs having a pair of rear wheels and a front wheel. With this arrangement, there are examples of both rear-wheel-drive and front-wheel-drive chairs. Alternatively, four-wheel motorized wheelchairs are also available. With this arrangement, the larger rear wheels are normally the driven wheels and the smaller front wheels are normally idler wheels. One major drawback of most three-wheeled and four-wheeled wheelchair arrangements is the fact that the motor and drive apparatus are permanently installed on the wheelchair. This results in high cost, excessive weight and a wheelchair which cannot be easily collapsed to be transported.
For these and other reasons, motorized attachments for standard wheelchairs have been developed. However, these attachments have suffered from the drawbacks of being overly complex and heavy so that the occupant or user of the wheelchair cannot easily connect and disconnect the motorized attachment to the wheelchair while in the chair.
For example, U.S. Pat. No. 5,016,720 issued to Coker, discloses a battery-powered steerable electric drive unit for detachable connection to a conventional wheelchair. The unit includes a clamp for receiving and being connected to a bolt extending from the frame underneath the wheelchair in a position inaccessible to the user.
U.S. Pat. No. 3,921,744 issued to Benoit et al. discloses a detachable drive means for a wheelchair that is manipulable by the occupant but is heavy and complex. The connecting means includes ramps that guide laterally-sliding pins toward their sockets and rotatable cams received in vertical slots at the forward ends of the wheelchair arm rests.
U.S. Pat. No. 4,503,925 issued to Palmer et al. discloses a steerable motorized power unit constructed for detachable coupling to a wheelchair. Coupling pins are provided with mounting plates which can be fixably clamped to the chair frame to engage with a downwardly opening recess formed in a member of the detachable power unit. However, this arrangement is also heavy and cumbersome.
In order to address these and other problems and to achieve an improved method and apparatus for attaching a motorized wheel to a wheelchair, the following invention has been developed.
SUMMARY OF THE INVENTION
The apparatus for attaching a motorized wheel to a wheelchair includes a mounting frame operatively connected to the motorized wheel and a mounting bracket operatively connected to the frame of the wheelchair, wherein the bracket defines an open slot for receiving a laterally-extending cylindrical member of the mounting frame. The slot defines an interior cam surface and is open on the front side thereof and enclosed on the bottom, back and top sides thereof. The mounting frame and motorized wheel can be rotated so that the cylindrical member bears against the interior cam surface of the mounting bracket and lifts a front wheel of the wheelchair off the ground.
Another aspect of the present invention includes a method for mounting a motorized wheel to a frame of a wheelchair including the first step of positioning the motorized wheel relative to the wheelchair so that a first laterally-extending cylindrical member of a mounting frame attached to the motorized wheel engages with an interior cam surface of a mounting bracket attached to the wheelchair. The motorized wheel and mounting frame are then pivoted about the first cylindrical member until a second cylindrical member of the mounting frame is aligned with and is in position to engage with a receptacle of the mounting bracket on the wheelchair frame. The mounting frame is then engaged with the mounting bracket to attach the motorized wheel to the wheelchair.
Other aspects of the present invention include the open slot in the mounting bracket having a C-shape, a width adjusting means in the mounting frame for selectively varying and adjusting the width of the frame to accommodate a variety of differently-sized wheelchairs, and the second cylindrical member being a selectively slidable pin within the mounting frame.
Other aspects, features and details of the present invention can be more completely understood by reference to the following detailed description of the preferred embodiment, taken in conjunction with the drawings, and from the appended claims.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a standard wheelchair with a detachable motorized unit attached to the wheelchair by the apparatus of the present invention.
FIG. 2 is an enlarged isometric view of the attachment apparatus shown in FIG. 1.
FIG. 3 is an exploded view of the attachment apparatus shown in FIG. 1 along with selected portions of the detachable motorized unit.
FIG. 4 is a side elevational view of the attachment apparatus shown in FIG. 1 installed on the wheelchair and receiving the motorized unit.
FIG. 5 is a front elevational view of the apparatus in FIG. 4.
FIG. 6 is a schematic of the apparatus shown in FIG. 4 showing initial placement of the mounting frame into a C-shaped opening in the mounting bracket.
FIG. 7 is a schematic of the apparatus shown in FIG. 4 showing the mounting frame after being moved relative to the mounting bracket by actuation of an installation handle.
FIG. 8 is a schematic of the apparatus shown in FIG. 4 showing the mounting frame moved further relative to the mounting bracket so that a fixed pin of the mounting frame bears against a top edge of the C-shaped opening in the mounting bracket.
FIG. 9 is a schematic of the apparatus shown in FIG. 4 showing further actuation of the installation handle to begin to lift a front wheel of the wheelchair off the ground.
FIG. 10 is a schematic of the apparatus shown in FIG. 4 showing further actuation of the installation handle to align a slide pin of the mounting frame with an opening formed in the mounting bracket.
FIG. 11 is a fragmented section taken along line 11--11 of FIG. 4.
FIG. 12 is an isometric view of a portion of the apparatus shown in FIG. 2, showing the attachment of the mounting bracket to the frame of the wheelchair.
FIG. 13 is another isometric view of the apparatus shown in FIG. 12.
FIG. 14. is an isometric view of an alternative embodiment showing a second mounting bracket mounted on a tubular portion of the frame of the wheelchair.
FIG. 15 is another isometric view of the apparatus shown in FIG. 14.
FIG. 16 is an exploded isometric view of the mounting frame and mounting brackets of the second embodiment.
FIG. 17 is a schematic of the drive components of the detachable motorized unit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The apparatus 20 of the present invention as best seen in FIGS. 2 and 3 is employed to attach a detachable motorized unit 22 to a wheelchair 24. The apparatus includes a mounting frame 26 detachably connected to the motorized unit and a pair of mounting brackets 30 attached to the wheelchair for supporting the mounting frame on the wheelchair. A first embodiment of the apparatus 20 is used for collapsible wheelchairs. A second embodiment of the apparatus, described later, is used for attachment of the detachable motorized unit to rigid, non-collapsible wheelchairs.
The collapsible wheelchair 24 (FIGS. 1 and 4) includes a frame 32 composed of a plurality of hollow tubular members 34. The frame supports a seat 36 and a seat back 40. The wheelchair frame 32 is supported by a pair of relatively large rear wheels 42 and a pair of relatively smaller front caster or idler wheels 44. For supporting the arms and legs of the occupant, a pair of arm rests 46 and foot rests 50 are conventionally mounted on the frame. An exemplary wheelchair is sold under the product designation QUICKIE II by Motion Design, Inc. of Fresno, Calif.
The pair of mounting brackets 30 (FIGS. 2, 3, 12 and 13) are mounted on the tubular frame 32 of the wheelchair 24. Each bracket 30 is preferably composed of a sturdy material such as aluminum, metal or plastic and is formed to define a plurality of openings therein. A circular opening 52 best seen in FIG. 3 and an oval or slot-shaped opening 54 receive mounting bolts 56 which are part of the mounting hardware for the front caster wheels 44 on the wheelchair 24. Each of the mounting brackets are held in place against the frame 32 of the wheelchair by a pair of nuts 60 threaded onto the bolts 56. The variability provided by the oval-shaped opening allows the mounting brackets to be used on a variety of differently-sized and configured collapsible wheelchairs.
For support of the mounting frame 26 of the apparatus 20, the mounting brackets 30 each include a slotted or C-shaped opening 62 defined in a front edge 64 of the brackets by an interior cam surface, as shown in FIG. 2. In addition, a second circular opening 66 is defined in each of the brackets 30 adjacent to a top edge 70 for further support of the mounting frame (FIG. 13). To facilitate support of the mounting frame 26, a laterally and inwardly extending lip 72 is formed on an inner side 74 of each of the mounting brackets 30 adjacent to the second circular opening. The lip 72 extends along approximately one-quarter of the periphery of the second circular opening 66.
The detachable motorized unit 22 (FIG. 3) includes a steering or control handle 76, a steering control rod assembly 80, and a power head 82 with a motor 84 (FIG. 17) and drive wheel 86. The motor 84 receives command signals from the control handle 76. As best seen in FIG. 17, the motor is linked to a gear assembly 90 by a timing drive belt 92. In turn, the gear assembly 90 is linked to the drive wheel 86 by a drive chain 94. Thus, activation of the motor results in rotation of the drive wheel in a conventional manner. Each of these drive components is mounted to and housed within a power head housing 96. A pair of battery lead wires 100 (FIG. 3), having battery connectors 102 at an end thereof, extend from the motor 84 through the housing 96 for connection to a battery as discussed below.
The control handle 76 is connected to the power head 82 by the steering control rod assembly 80. The control rod assembly 80 includes an upper tube 104 and a lower tube 106. The lower tube 106 is connected to the power head housing 96. The upper tube 104 is connected to the control handle 76 at its upper end 110. A lower end 111 of the upper tube 104 is bifurcated to form a key slot 113 for engagement with a complementary member (not shown) in the lower tube 106 so that the upper and lower tubes are pivotable in unison about their longitudinal axes. The upper tube is telescopically received in the open upper end 114 of the lower tube 106 and retained in position by a collar 112 and a set screw 117. Thus, by tightening or loosening the retaining collar 112, the upper tube can be connected to or disconnected from the lower tube.
The T-shaped control handle 76, connected to the upper end 110 of the upper tube 104 of the steering control rod assembly 80, is provided so that the operator can control the direction and speed of the detachable motorized unit 22 and thus of the wheelchair 24, when motorized. The control handle 76 includes a pair of hand grips 115 and a forward/reverse rocker switch 116. This switch 116 serves in a conventional way to control the activation and direction of rotation of the motor 84 discussed above. The detachable motorized unit 22 is available as part of a motorized wheelchair sold under the product designation AMIGO by Amigo Sales Inc. of Bridgeport, Mich.
The mounting frame 26 (FIGS. 3 and 11) includes a hollow, vertical center support tube 120 for rotatably receiving the steering control rod assembly 80 of the detachable motorized unit 22. The center support tube 120 is connected to a pair of transverse lower and upper horizontal support tubes 122 and 124. Attached to as by welding and depending from the transverse support tubes 122 and 124 is a battery frame assembly 126. The battery frame assembly includes a base plate 127 supported by a plurality of extension arms 128 depending from the support tubes 122 and 124. For retaining a battery 129 within the frame assembly 126, a retaining strap is attached to the base plate 127. The battery connectors 102 on the ends of the battery lead wires 100 can be attached to a pair of terminals 132 on the battery 129.
For adjusting the width of the mounting frame 26 to allow the apparatus to be mounted on a variety of wheelchairs of various widths, a pair of support collars 134 are slidably received on each open end of the transverse support tubes 122 and 124. The support collars are adjustably affixed to the transverse support tubes by set screws 136. The screws 136 protrude through the support collar and associated transverse support tube 122 or 124 so as to be engagable with laterally adjustable sleeves 140 and 142 slidably received within the upper and lower support tubes respectively. There are a pair of the sleeves 140 associated with the support tube 124 and a pair of the sleeves 142 associated with the support tube 122 with the sleeves projecting out of the opposite open ends of the support tubes.
The adjustable sleeves 140 and 142 can be repositioned to different longitudinal positions as desired by loosening and tightening the set screws 136. Thus, the overall width of the mounting frame 26 can be adjusted while leaving the center support tube 120 centered between the sides of the wheelchair.
For engagement with and support by the mounting bracket 30, a fixed pin 144 is received within opposite open ends of the lower adjustable sleeve 142. The fixed pin includes a shaft 150 and an enlarged integral head 156 at a free end of the shaft. The fixed pin has a blind threaded radial hole 146 in its shaft 150 for receiving an attachment screw 152 protruding through an unthreaded hole 154 in the associated lower adjustable sleeve 142.
For selective engagement with the mounting bracket 30, a slide pin 160 protrudes from and is slidably received in each open end of the upper adjustable sleeve 140. Each slide pin includes a shaft 162 and a rounded head 164 on its free end. Each upper adjustable sleeve 140 has a longitudinal slot 166 along a top surface for receiving an adjustment screw 170 with a knob 172 on an end thereof. The screw 170 protrudes slidably through the longitudinal slot 166 and is threadedly received in a radial blind hole 174 in the slide pin 160. By tightening the screw 170, the slide pin can be longitudinally fixed within the upper adjustable sleeve. Conversely, upon loosening the screw 170, the slide pin can be repositioned longitudinally within the adjustable sleeve 140. Thus, the slide pin can be selectively moved into and out of operative engagement with the mounting bracket 30. Alternatively, the screw 170 could be replaced with a spring-biased locking device (not shown).
For facilitating the connection of the detachable motorized unit 22 to the wheelchair 24, an installation handle 176 is provided (FIGS. 6-10). The L-shaped installation handle 176 can be inserted into the open upper end 114 of the lower tube 106 of the steering control rod assembly 80, after the upper tube 104 has been removed. A grip portion 180 of the installation handle is provided as a lever arm for installation of the detachable motorized unit 22.
As shown sequentially in FIGS. 6-10, the detachable motorized unit 22, with the installation handle 176 inserted, is brought into proximity with the front of the wheel chair 24. The slide pins 160 in each of the upper width adjustable sleeves 140 are first placed in the retracted position. The fixed pins 144 of the lower width adjustable sleeves 142 are placed in the C-shaped opening 62 of the mounting brackets 30 (FIG. 6). The motorized unit 22 is thus supported by its drive wheel 86 with the fixed pins 144 bearing against a bottom surface 182 of the C-shaped opening 62. This operation can be easily accomplished by the occupant in the wheelchair.
Next, the occupant pivots the detachable motorized unit 22 by applying a downward and forward force to the grip portion 180 of the installation handle 176. As the unit is pivoted clockwise as viewed in FIGS. 6-10, the fixed pin slides along the cam surface from the bottom surface 182 of the opening 62 along a side surface 184 and into engagement with a top surface 186 of the C-shaped opening (FIGS. 7 and 8). As the operator continues to pivot the motorized unit by applying downward force on the grip portion 180, the front caster wheels 44 of the wheelchair 24 are lifted off the supporting surface (FIG. 9). The wheelchair is now supported by the rear wheels 42 and the drive wheel 86 of the detachable motorized unit 22, through the cooperative action of the mounting bracket 30 and the mounting frame 26. The operator continues to pivot the motorized unit until the rounded end 164 of the retracted slide pin 160 contacts the protruding lip 72 formed on the inner side 74 of the mounting brackets 30 (FIGS. 10 and 13). At this point, the retracted slide pins can be repositioned longitudinally and locked in position with knobs 172 so that the pins protrude through and engage with the second circular openings 66 formed in the mounting brackets 30. Thus, the mounting frame 26 is now securely attached to the mounting brackets 30 and in turn to the wheelchair 24.
Before or after the motorized unit is positioned and attached to the wheelchair as described above, the occupant can slide the battery 129 into the battery frame assembly 126 (FIG. 3) so that the battery connectors 102 of the battery lead wires 100 can be attached to the battery terminals 132. Once the installation handle 176 is removed from the lower tube 106, the upper tube 104 of the steering control rod assembly 80 can be inserted. The motorized wheelchair is then ready for operation.
To disconnect the motorized unit 22 from the wheelchair 24, the occupant reverses the above-described procedure (FIGS. 6-10). The upper tube 104 of the steering control rod assembly 80 is removed from the lower tube 106 and replaced with the installation handle 176. After loosening the knobs 172, the slide pins 160 are retracted out of engagement with the second circular opening 66 of the mounting brackets 30. The operator then applies an upward force to the grip portion 180 of the installation handle 176 so as to pivot the motorized unit and return the front caster wheels 44 of the wheelchair 24 into engagement with the support surface. As the motorized unit continues to be pivoted, the fixed pins 144 of the mounting frame 26 slide along the side surface 184 of the C-shaped opening 62 and into engagement with the bottom surface 182 thereof. The fixed pins can then be lifted out of the C-shaped opening to completely disconnect the motorized unit from the wheelchair.
A second embodiment 188 of the mounting frame and mounting brackets for use with a rigid, non-collapsible wheelchair is shown in FIGS. 14-16. Similar components from the first embodiment are shown with a prime (') denotation. Mounting brackets 190 affixed to the wheelchair frame at laterally spaced locations include a C-shaped opening 62', an intermediate slot-shaped opening 54' and upper and lower circular openings 66' and 52', respectively Each of the mounting brackets 190 is attached to the wheelchair 24 via a frame clamp 194. The frame clamp 194 includes a pair of confronting U-shaped members 196 clamped to a hollow tubular portion of the frame 32 of the wheelchair 24. Bolts 56' extend through the U-shaped members 196 and through the lower and intermediate openings 52' and 54' of the mounting bracket 190. The bolts are retained in place by a pair of nuts 60'. The mounting bracket includes a protruding lip 72' formed adjacent to the upper circular opening 66'.
The second embodiment 200 of the mounting frame includes a center support tube 120' and a pair of transverse support tubes 122' and 124'. The support tubes are supported on the rear side of the center support tube 120' by a bracket 202. Other than this opposite mounting of the support tubes to the center support tube, the mounting frame 200 is substantially identical to the first embodiment 26 of the mounting frame. Connection and disconnection of the motorized unit 22 to the wheelchair 24 using the mounting frame 200 and mounting bracket 190 is identical to that of the mounting frame 26 and mounting brackets 30 described above.
A presently preferred embodiment of the present invention has been described above with a degree of specificity. It should be understood, however, that this degree of specificity is directed toward the preferred embodiment. The invention itself, however, is defined by the scope of the appended claims. | An apparatus and method for attaching a motorized wheel to a wheelchair including a mounting frame operatively connected to the motorized wheel, the frame having a laterally-extending cylindrical member, and a mounting bracket operatively connected to a frame of the wheelchair, the bracket having an open slot for receiving the cylindrical member of the mounting frame, the slot defining an interior cam surface which is open on the front side thereof and enclosed on the bottom, back and top sides thereof. The frame has means for adjusting the width thereof to accommodate a variety of different wheelchairs. The mounting frame has a second laterally-extending cylindrical member which is a slidable pin for selective engagement with the mounting bracket to attach the motorized wheel to the wheelchair. | 0 |
OBJECT OF THE INVENTION
The invention herein relates to a system for the mounting of shelving, which allows for the provision of multiple shelves adequately separated in height to allow the placement thereon of pieces of crockery such as plates, bowls, coffee cups, trays, dessert dishes, etc., together with the contents thereof, thereby obtaining the maximum use of available space.
The system is especially suitable for use in refrigerators, for the purpose of improving the vertical division of same, but is equally useful outside same, wherever space-saving or a better use of available space is required, as for example on a kitchen work-top, on a table for the stacking of dishes whether full or empty, on shelves, etc.
In any event the structure of this system is easily assembled or dismantled, so that apart from the aforesaid characteristics, the space occupied by the system when not in use or while being dismantled is minimal.
BACKGROUND OF THE INVENTION
In relation to refrigerators, one of the areas in which the system is applicable, the sides of the interior of refrigerators usually come with slots which allow the regulation in height of the shelving, meshes or racks, so that starting with an original spacing between the shelves which tends to be in the region of 20 cm., such spacing can be changed by increasing it in some cases and reducing it in others, subject always to certain restrictions dictated by the original structure of the appliance.
Outside the refrigerator or any other similar container, there are known simple or multiple trays, the latter of which are usually two tier, which tend to increase the storage capacity of any determined space, but which obviously offer a very limited level of capacity and usually constitute a single bulky piece which is difficult to store.
In any event, there does not presently exist a system for the mounting of shelving which, starting from a modular design, permits the optimum use of available space on the basis of closely spaced shelves through the placement at different levels of individual pieces of crockery, such as for example plates, bowls, etc., foods containers.
DESCRIPTION OF THE INVENTION
The system which this invention proposes fills this technological gap by offering a simple rational solution with a high level of capacity.
For this purpose and more precisely, the essential element of said system is a small flat module, which basically constitutes a separating leg between shelves, and which has means for attachment for the mesh of the corresponding shelf itself, as well as tongue and groove attachments for coupling to the modules immediately below and above so that a racking effect is achieved with such modules creating a global support for the entire shelving structure which together with another three legs gives the entire structure appropriate stability.
More precisely, each module has at the top two cylindrical parallel and horizontal slots which are intended to hold the ends of the rods belonging to the metal support which constitutes the corresponding shelf, it having been envisaged that such slots should have a cut along their shanks, so that they could act as elastically deformable elements thus giving a maximum hold on the said rods and a better fitting of same.
On the other hand each module has an appendage at its lower end, preferably with a graduated front, with a lateral protuberance close to its open side which acts as a fixing clip, while at its upper end it has a slot to accommodate the appendage of the module immediately above which it will hold so that a perfect fit is achieve between modules which in turn ensures a perfectly perpendicular continuous racking of the elements while same remain attached to each other through the clips which join them.
As a complement to the said structure it has been envisaged that each continuous rack or stack of modules should be fitted at the bottom with a small rectangular foot fitted with a slot as previously described which when fitted to the end of the bottom module would appropriately complete the shelving structure for placement on any type of flat surface.
DESCRIPTION OF THE DRAWINGS
To complement the description which is hereby set out and with a view to a better understanding of the characteristics of the invention, the within specifications are accompanied by a set of drawings which form an integral part of same, and where the following is set out for illustrative purposes but without limiting the scope hereof:
FIG. 1: Shows a view of one of the modules which form part of the shelving assembly for pieces of crockery and the like which constitutes the subject of this invention, together with a view by sections of the part of a mesh forming part of a shelf and a rectangular foot for the completion of the lower end.
FIG. 2: Shows an opposite view to that in the preceding diagram of a pair of modules duly attached to each other, facing the corresponding rectangular foot and showing a partial view of the corresponding shelves duly affixed.
FIG. 3: Shows a section in detail of the linkage between two super-imposed modules, in accordance with cross-section a-b in FIG. 2.
FIG. 4: Shows a general view of a multiple shelving unit built in accordance with the mounting system which is the subject of this invention, in which two circular plates are shown placed on one of the shelves.
FIG. 5: Shows, finally, the frontal elevation of the unit illustrated in the preceding FIG. 4, but one should highlight that the number of shelves, which in the said Figure is two, can be increased to any reasonably required level.
IDEAL CONSTRUCTION OF THE INVENTION
In view of these Figure one can note how the suggested system is based on the use of identical modules (1), ideally molded in an appropriate plastic material, flattened, comprising a large open area (2) which reduces its weight as well as the amount of material used in same without reducing its structural rigidity, the module (1) being of a length which relates to the distance which is envisaged between shelves (3) and which ideally is in the region of 5 cm., although obviously this figure can vary depending on the specific requirements of each practical situation without affecting the essence of the invention.
Each module (1) has at its top a pair of horizontal protrusions (4) which point inward and on which there are parallel and horizontal blind slots and holes (5) to accommodate the rods (6) which form part of the corresponding shelving (3). As previously indicated, these slots (5) should ideally have a cut (7) along their shanks which would allow them to be elastically deformable and facilitate a more secure fitting of the rods therein under pressure.
On the other hand, for the tongue and groove coupling of modules (1) forming a continuous rack as can be seen from FIGS. 2 and 5, each module has at the bottom an appendage with a graduated front (8), and on whose graduations there is a lateral protrusion (9), while at the top there is a slot (10) to house the said appendage, and in the center of same fissure (11) to which the protrusion (9) fits as a clip through elastic expansion, giving rise to a stable coupling which nevertheless allows a simple dismantling of the structure through the simple pulling of one module (1) away from another.
The structure described above is complemented by a rectangular foot 12 intended to complete the bottom of each of the vertical stacks or continuous racks built with modules (1), each such rectangular foot 12 having, for its attachment to the rack (1), (1) . . . , a slot (13) similar to the slot (10) belonging to the aforementioned modules (1) and in which there is likewise a lateral and interior fissure (14) similar to the aforesaid fissure (11) and with the same purpose of housing and holding the module (1) immediately above through the latter's clip (9).
In this way, as can be seen in particular from FIGS. 4 and 5, a light structure is achieved, with a high capacity for the storage of crockery, for example plates (15), with a structure which is easily assembled and dismantled, and which, as a result, easily allows the adaptation of the number of shelves in the structure to the requirements of any particular situation, whether this relates to the fitting of the multi-shelf structure in a refrigerator, freezer or the like, or whether what is required is the increase of storage capacity over any flat surface.
It is considered that it is not necessary to expand this description for any expert in this field to understand the scope of the invention and the advantages of same.
The materials, shape, size and arrangements of the elements are subject to change provided always that this does not imply a change in the purpose of the invention.
The provisions of this memo should always be interpreted in a wide and not limiting sense. | System for the mounting of shelving for pieces of crockery and the like, consisting of a multiplicity of identical modules (1), stacked vertically and interconnectable through tongue and groove pressure coupling, each of which has lateral and internal protrusions each with blind orifices, to house the rods (6) belonging to the relevant shelves, so that the selves (3) remain separated by a distance equivalent to the length of the modules (1), a minimum distance which is however sufficient to allow the placements of plates, bowls or other prices of crockery on each self, with maximum use of available space. | 5 |
BACKGROUND OF THE INVENTION
[0001] Snoring is very common among mammals including the humans. Snoring is a noise produced while breathing during sleep due to the vibration of the soft palate and uvula. Not all snoring is bad, except it bothers the bed partner or others near the person who is snoring. If the snoring gets worst over time and goes untreated, it could lead to apnea.
[0002] Those with apnea stop breathing in their sleep, often hundreds of times during the night. Usually apnea occurs when the throat muscles and tongue relax during sleep and partially block the opening of the airway. When the muscles of the soft palate at the base of the tongue and the uvula relax and sag, the airway becomes blocked, making breathing labored and noisy and even stopping it altogether. Sleep apnea also can occur in obese people when an excess amount of tissue in the airway causes it to be narrowed.
[0003] In a given night, the number of involuntary breathing pauses or “apneic events” may be as high as 20 to 60 or more per hour. These breathing pauses are almost always accompanied by snoring between apnea episodes. Sleep apnea can also be characterized by choking sensations.
[0004] Sleep apnea is diagnosed and treated by primary care physicians, pulmonologists, neurologists, or other physicians with specialty training in sleep disorders. Diagnosis of sleep apnea is not simple because there can be many different reasons for disturbed sleep.
[0005] The specific therapy for sleep apnea is tailored to the individual patient based on medical history, physical examination, and the results of polysomnography. Medications are generally not effective in the treatment of sleep apnea. Oxygen is sometimes used in patients with central apnea caused by heart failure. It is not used to treat obstructive sleep apnea.
[0006] Nasal continuous positive airway pressure (CPAP) is the most common treatment for sleep apnea. In this procedure, the patient wears a mask over the nose during sleep, and pressure from an air blower forces air through the nasal passages. The air pressure is adjusted so that it is just enough to prevent the throat from collapsing during sleep. The pressure is constant and continuous. Nasal CPAP prevents airway closure while in use, but apnea episodes return when CPAP is stopped or it is used improperly. Many variations of CPAP devices are available and all have the same side effects such as nasal irritation and drying, facial skin irritation, abdominal bloating, mask leaks, sore eyes, and headaches. Some versions of CPAP vary the pressure to coincide with the person's breathing pattern, and other CPAPs start with low pressure, slowly increasing it to allow the person to fall asleep before the full prescribed pressure is applied.
[0007] Dental appliances that reposition the lower jaw and the tongue have been helpful to some patients with mild to moderate sleep apnea or who snore but do not have apnea. A dentist or orthodontist is often the one to fit the patient with such a device.
[0008] Some patients with sleep apnea may need surgery. Although several surgical procedures are used to increase the size of the airway, none of them is completely successful or without risks. More than one procedure may need to be tried before the patient realizes any benefits. Some of the more common procedures include removal of adenoids and tonsils (especially in children), nasal polyps or other growths, or other tissue in the airway and correction of structural deformities. Younger patients seem to benefit from these surgical procedures more than older patients.
[0009] Uvulopalatopharyngoplasty (UPPP) is a procedure used to remove excess tissue at the back of the throat (tonsils, uvula, and part of the soft palate). The success of this technique may range from 30 to 60 percent. The long-term side effects and benefits are not known, and it is difficult to predict which patients will do well with this procedure.
[0010] Laser-assisted uvulopalatoplasty (LAUP) is done to eliminate snoring but has not been shown to be effective in treating sleep apnea. This procedure involves using a laser device to eliminate tissue in the back of the throat. Like UPPP, LAUP may decrease or eliminate snoring but not eliminate sleep apnea itself. Elimination of snoring, the primary symptom of sleep apnea, without influencing the condition may carry the risk of delaying the diagnosis and possible treatment of sleep apnea in patients who elect to have LAUP. To identify possible underlying sleep apnea, sleep studies are usually required before LAUP is performed.
[0011] Somnoplasty is a procedure that uses radio frequency (RF) to reduce the size of some airway structures such as the uvula and the back of the tongue. This technique helps in reducing snoring and is being investigated as a treatment for apnea.
[0012] Tracheostomy is used in persons with severe, life-threatening sleep apnea. In this procedure, a small hole is made in the windpipe and a tube is inserted into the opening. This tube stays closed during waking hours and the person breathes and speaks normally. It is opened for sleep so that air flows directly into the lungs, bypassing any upper airway obstruction. Although this procedure is highly effective, it is an extreme measure that is rarely used.
[0013] Patients in whom sleep apnea is due to deformities of the lower jaw may benefit from surgical reconstruction. Surgical procedures to treat obesity are sometimes recommended for sleep apnea patients who are morbidly obese. Behavioral changes are an important part of the treatment program, and in mild cases behavioral therapy may be all that is needed. Overweight persons can benefit from losing weight. Even a 10 percent weight loss can reduce the number of apneic events for most patients. Individuals with apnea should avoid the use of alcohol and sleeping pills, which make the airway more likely to collapse during sleep and prolong the apneic periods. In some patients with mild sleep apnea, breathing pauses occur only when they sleep on their backs. In such cases, using pillows and other devices that help them sleep in a side position may be helpful.
[0014] Recently, Restore Medical, Inc., Saint Paul, Minn. has developed a new treatment for snoring and apnea, called the Pillar technique. Pillar System is a procedure where 2 or 3 small polyester rod devices are placed in the patient's soft palate. The Pillar System stiffens the palate, reduces vibration of the tissue, and prevents the possible airway collapse. Stiff implants in the soft palate, however, could hinder patient's normal functions like speech, ability to swallow, coughing and sneezing. Protrusion of the modified tissue into the airway is another long-term concern.
[0015] As the current treatments for snoring and/or apnea are not effective and have side-effects, there is a need for additional treatment options. For the treatments that rely on the implants in the patient 's airways, there is a need for systems and methods for inserting the implants into the airways.
BRIEF SUMMARY OF THE INVENTION
[0016] The present invention relates to methods and tools that insert implants for the treatment of snoring and sleep apnea in a cavity created in the patient's airway passage tissue. Some tools and methods can additionally verify that the cavity has proper cavitation depth and that it does not have unwanted perforations.
[0017] In one embodiment, a system for inserting an implant into a cavity in a periosteum region of patient's palate includes: a sheath having a substantially flat portion for housing an implant, the sheath having a distal end and a proximal end, the sheath having a hollow collar on the proximal end, an insertion depth mark near the distal end, and a slit on the distal end, the slit being in fluid communication with the hollow collar; and a substantially rigid pusher configured to be disposed within and in a slidable engagement with the sheath, the pusher having a distal end and a proximal end, the pusher having a rigid body having an outside diameter for slidably engaging with the hollow collar of the sheath, a tip on the distal end configured for engaging a proximal end of an implant, and a lumen extending from said proximal side to said distal side of said rigid body, the lumen being configured for fluid communication with a syringe at the proximal end and being in fluid communication with the sheath at the distal end.
[0018] In one aspect, the implant is disposed in the flat portion of the sheath.
[0019] In another embodiment, a method for inserting an implant into a cavity in a periosteum region of patient's palate includes: cutting the periosteum region with a sharp surgical tool to create a cavity; inserting a sheath having an insertion depth mark and an implant into the cavity; verifying that the sheath is insertable into the cavity up to the insertion depth mark; injecting a saline solution from a syringe into the cavity through a lumen of a pusher disposed with said sheath; verifying that the saline solution flows back out of the cavity, thus ensuring a perforation-free cavity; and sliding the sheath out of the cavity and along the pusher, while holding the pusher in a fixed contact with the implant, thus leaving the implant inside the cavity.
[0020] In another aspect, the saline solution flows back out of the incision through one or more perfusion holes on the sheath.
[0021] In another embodiment, a system for inserting an implant into a cavity in a periosteum region of patient's palate includes: a sleeve having a substantially flat portion configured for housing an implant, the sleeve having a distal end and a proximal end, the sleeve being slitted at the distal end and the proximal end, the sleeve being connected at the proximal end with a substantially flexible handle that extends proximally; a substantially rigid stylet for slidably engaging with the sleeve and configured for pushing the implant out of the sleeve, the stylet having a distal end and a proximal end, the stylet having a peripheral slit at the proximal end, an inner slit disposed between the proximal and distal ends, and a tip on the distal end for engaging a proximal end of an implant; and the substantially flexible handle configured for slidable connection with the stylet, whereby the handle is configured to slide inside the stylet between the peripheral slit and the inner slit of the stylet, and whereby the handle is configured for a placement outside the stylet between the inner slit and the distal end of the stylet.
[0022] In another aspect, the sleeve has a depression substantially at the distal end of the sleeve for keeping the implant securely inside the sleeve.
[0023] For a further understanding of the nature and advantages of the invention, reference should be made to the following description taken in conjunction with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a cross sectional view of a patient's head showing the hard and soft palate.
[0025] FIG. 2 is schematic depiction of the occurrence of an apneic event due to the blockage of the airway.
[0026] FIG. 3 shows relationship of the implant, soft palate, and the airway blockage.
[0027] FIG. 4 shows a perspective view of an implant.
[0028] FIG. 5 shows an implant device in the soft palate.
[0029] FIG. 6 shows a top planar view of an embodiment of the cavitation tool.
[0030] FIG. 6A shows a cavitation depth verification using the cavitation tool of FIG. 6 .
[0031] FIG. 6B shows a cavity perforation verification using the cavitation tool of FIG. 6 .
[0032] FIG. 6C shows a delivery of an implant using the cavitation tool of FIG. 6 .
[0033] FIG. 7 shows several views of an embodiment of the implant delivery tool.
[0034] FIG. 8 shows an exploded view of an embodiment of the implant delivery tool of FIG. 7 .
[0035] FIG. 8A shows a delivery of an implant using the implant delivery tool of FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
[0036] The embodiments of the present invention are directed toward tools and methods for inserting an implant device that treats snoring and apnea. The tools and methods can verify the sufficiency of cavity depth for the implant fit, and also whether the cavity is perforation-free. The tools and methods have numerous advantages. For example, the tools can be used to verify the proper depth and the absence of the perforation in the cavity, followed by leaving the implant in the cavity without the need to take the tool out first. The details of the exemplary embodiments of the present invention are explained with reference to FIGS. 1-8 .
[0037] FIG. 1 shows a cross-sectional view of patient's palate having soft palate 84 and hard palate 74 . Periosteum 118 is a membrane that lines the outer surface of hard palate 74 . Periosteum region includes hard palate 74 , Periosteum 118 , and soft palate 84 . The tools that are described below are inserted through the mouth of the patient, and into the cavity in the patient's palate. An incision is made in soft palate 84 , and a cavity is formed in the soft palate, and may also extend to a portion of hard palate 74 .
[0038] FIG. 2 depicts the occurrence of an apneic event due to the blockage of airway 3701 by the movement of soft palate 84 . Detail 2 A shows soft palate 84 position during normal breathing cycle. An airway gap 3803 is maintained between the soft palate 84 and laryngeal wall 3804 to maintain airflow 3805 . Airway gap 3803 is the most narrow part of the overall airway 3701 . Detail 2 B shows the position of soft palate 84 just prior to the blockage of airway 3701 . It can be seen that airway gap 3803 ′ in Detail 2 B is smaller than airway gap 3803 in Detail 2 A because soft palate 84 has moved towards laryngeal wall 3804 . This causes a reduction in the space available to maintain the airflow. Detail 2 C shows soft palate 84 blocking airway 3701 . Here, soft palate 84 came to a contact with laryngeal wall 3804 thus cutting off airflow 3805 . Since there is no flow of oxygen to the brain, an apneic event occurs, causing a brief wake-up and increased tension in soft palate 84 in order to open airway gap 3803 .
[0039] FIG. 3 shows implant 3 inserted in patient's soft palate 84 . Implant 3 can be used to prevent the sequence of events described in FIG. 2 . Some implants for snoring or apnea treatment are disclosed in the assignee's patent application Ser. No. 11/613,027 (“Implant for Treatment of Sleep Disorders”), which is herein incorporated by reference. Implant 3 can have a changeable stiffness or shape, thus being able to modulate the position of soft palate 84 , which can modulate the size of gap 3803 in airway 3701 . Power source and/or control electronics (not shown) may also be implanted in patient's tissue or held on a retainer which may be placed in the mouth or external to the mouth of the patient.
[0040] FIG. 4 shows a perspective view of an embodiment of implant 3 . An electrically controlled implant is shown, but other types of control and other shapes of the implant are possible. Implant 3 can have Printed Circuit Board (PCB) 31 for receiving power and signal input from a power supply and control electronics. Implant 3 can have flexible body 30 that can change its shape or stiffness in response to the signal sent from PCB 31 or other control electronics (not shown).
[0041] FIG. 5 shows a partial cross-sectional view of patient's mouth. Tooth 64 is at the proximal side of the mouth. Patient's palate has hard palate 74 , periosteum 118 , and soft palate 84 . FIG. 5 shows implant 3 inserted through incision 95 and into cavity 94 formed in soft palate 84 , but implant 3 can also be inserted in hard palate 74 and/or periosteum 118 . Cavity 94 can be made by a variety of surgical tools and methods. Some of the tools and methods for making a cavity in patient's palate are described in a co-pending patent application No. (to be assigned; attorney file 026705-000200US). When the cavity extends to the hard palate, then periosteum 118 may be separated from or lifted off hard palate 74 . Implant 3 may take different shapes and sizes, and may be implanted in different locations along soft palate 84 . A change in the implant's shape or stiffness causes a change in soft palate 84 shape and, consequently, a change in the distance from soft palate 84 to laryngeal wall 3804 . Consequently, the size of gap 3803 that is available for airflow 3805 can be changed by changing the shape or stiffness of implant 3 . As explained in reference to FIG. 2 , an insufficient size of gap 3803 may obstruct airflow 3805 thus leading to snoring or an apneic event. A suitable change in implant 3 shape or stiffness may increase the size of gap 3803 , therefore preventing or reducing snoring and apneic events.
[0042] FIG. 6 shows a planar view of an embodiment of cavitation tool 10 . This embodiment of cavitation tool 10 can verify cavitation depth, verify that no cavitation perforations are present, and deliver implant 3 to cavity 94 . Cavitation tool 10 can have syringe 1 , pusher 2 , and sheath 4 . Implant 3 can be located inside sheath 4 , which can be shaped as a substantially flat pouch. Sheath 4 can have one or more implant engagement structures 46 located on the interior of the sheath for holding implant 3 securely in place. The engagement structures may be ribs, dimples, or other protrusions. The distal side of sheath 4 , which may contain implant 3 , can be inserted in perforation 94 (not shown). Sheath 4 can have one or more insertion depth mark 43 . The distance from slit 47 at the distal end of the sheath to insertion depth marks 43 can be designed to be at least as big as the minimum required depth of perforation 94 . Sheath 4 may be made of transparent plastic as a visual aid. Cavitation tool 10 can have syringe 1 containing a saline or similar solution. A substantially rigid pusher 2 can have pusher coupling 21 for fluidic coupling with the distal end of syringe 1 . Pusher coupling 21 can be threadably engaged with syringe 1 , but other engagements are also possible, for instance press fit or gluing. Lumen 23 for transporting saline solution can extend through pusher body 20 from pusher coupling 21 at the proximal end to pusher tip 22 at the distal end of the pusher. Pusher tip 22 is preferably located distally in reference to one or more profusion apertures 45 on sheath collar 44 . Some embodiments of cavitation tool 10 may not have syringe 1 or implant 3 . For example, if all that a surgeon wants to verify is a proper depth of the cavity then a tool having only pusher 2 and sheath 3 may be enough to accomplish the purpose, because no syringe, solution, or an implant would be needed for this purpose. Pusher 2 can have an outside diameter dimensioned for a slideable connection with sheath collar 44 . Pusher 2 and collar 44 can be substantially round, but other mating shapes are also possible. Pusher tip 22 at the distal end of the pusher can be in contact with the proximal end of implant 3 . PCB 31 may be at the proximal end and flexible body 30 may be at the distal end of implant 3 . Slit 47 can be substantially aligned with the distal end of implant 3 . Implant 3 can be securely held in place by implant engagement structure 46 in the interior of sheath body 40 .
[0043] FIG. 6A shows a cavitation depth verification using cavitation tool 10 . The distal end of cavitation tool 10 can be inserted in cavity 94 . An operator can keep moving cavitation tool 10 into the cavity up to or past insertion mark 43 on sheath 3 . Insertion mark 43 can be positioned at a predetermined distance from slit 47 on sheath 3 such that when mark 43 aligns with or passes incision 95 , an operator can conclude that cavity 94 is deep enough for the implant delivery.
[0044] The embodiment of cavitation tool 10 shown in FIG. 6 can also be used to verify the absence of perforations in cavity 94 . A perforation could be created if, for instance, an excessively long cavity is made such that the cavity runs through the soft palate and terminates in another incision in addition to the tool entrance incision. Normally, a cavity without perforations (other than incision 95 ) is preferred for housing implant 3 .
[0045] FIG. 6B shows a cavity perforation verification using cavitation tool 10 . When saline solution from syringe 1 is pushed through lumen 23 , saline solution enters sheath body 42 and, from there, saline solution enters cavity 94 . If there is an implant inside the sheath, the solution can flow around it. If the cavity has no perforations where saline solution could escape, saline solution flows back in the proximal direction, either through sheath body 42 , around pusher body 20 , and out of the sheath through perfusion apertures 45 , or between sheath body 42 and the walls of cavity 94 , and out through incision 95 . Thus, the flow of saline solution through profusion apertures 45 or through incision 95 can indicate that no perforations exist in the cavity. On the other hand, an ill-formed cavity having a drainage pathway in addition to incision 95 would allow for a drain of the saline solution, thus allowing the saline solution to escape from the cavity. Consequently, the saline solution would not flow through perfusion apertures 45 or the incision 95 , thus indicating a presence of the non-desired perforation in the cavity. If the tool is used to verify a perforations free cavity, then implant 3 would not necessarily be needed in that embodiment of the tool.
[0046] Cavitation tool 10 shown in FIG. 6 can also be used to deliver implant 3 into the cavity. FIGS. 6C shows a delivery of an implant using cavitation tool 10 . When sheath 4 is located at a desired location inside cavity 94 , thus positioning implant 3 at a desired location along cavity 94 , sheath 4 can be slid in the proximal direction while holding pusher body 20 in a fixed contact with implant 3 , thus leaving implant 3 in the cavity. Cavitation tool 10 can be removed from cavity 94 when implant 3 is not in contact with sheath 4 any more. Some embodiments of cavitation tool 10 may not have syringe 1 when the tool is used to deliver implant 3 in the cavity, because the delivery step may not need saline solution.
[0047] FIG. 7 shows several views of another embodiment of implant delivery tool 100 . The perspective view at the top of FIG. 7 shows implant delivery tool 100 having substantially rigid stylet 5 . Channel 9 (not visible) extends through stylet 5 from peripheral slit 7 on the proximal end of the stylet and at least past inner slit 52 on the stylet. In some embodiments, channel 9 may extend through the entire interior of stylet 5 , from peripheral slit 7 to another slit on the distal end of stylet 5 . Stylet 5 can be in a slidable engagement with sleeve 4 (see Detail D). Substantially flexible handle 6 can be disposed with stylet 5 , partially alongside the stylet and partially inside the stylet. Handle 6 can be disposed inside stylet 5 from peripheral slit 7 at the proximal end of the stylet (see Detail B) to inner slit 52 on the stylet (see Detail C). Handle 6 can be disposed outside and substantially alongside stylet 5 from inner slit 52 to sleeve 4 . Handle 6 can be in a fixed connection with sleeve 4 . Handle 6 can have handling button 8 at the proximal end for the easier operation.
[0048] Implant 3 can be housed in a substantially flat sleeve 4 . The proximal end of implant 3 can be in contact with the distal end of stylet 5 (see Detail D). The proximal end of implant 3 can be partially inside channel 9 . Sleeve 4 can have depression 57 to securely keep implant 3 inside the sleeve (see detail E).
[0049] FIG. 8 shows an exploded view of an embodiment of implant delivery tool 100 of FIG. 7 . In this embodiment, channel 9 extends through the entire stylet 5 , but other stylet embodiments where channel 9 extends at least from peripheral slit 7 to inner slit 52 are also possible. Handle 6 and sleeve 4 are shown as one piece, but other methods of fixed connection between handle 6 and sleeve 4 are also possible, for example by fasteners or by gluing or by other methods.
[0050] FIG. 8A shows a delivery of an implant using the implant delivery tool 100 . An operator can insert the distal end of implant delivery tool 100 into cavity 94 . Pulling handle 6 or button 8 (not shown) in the proximal direction while holding stylet 5 in a fixed contact with implant 3 causes sleeve 4 to move in the proximal direction, because sleeve 4 is connected to handle 6 . As sleeve 4 moves in the proximal direction, implant 3 stays in its place because stylet 5 , which is held fixed, prevents implant 3 from being pulled by sleeve 4 in the proximal direction. Therefore, when sleeve 4 is moved in the proximal direction enough to free implant 3 , the implant is delivered into cavity 94 . Implant delivery tool can be removed from cavity 94 , while implant 3 stays in the cavity.
[0051] As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. For example, the delivery tools may not have depression at the distal end, instead holding an implant by the retaining protrusions on the inside of the sleeve, like dimples, ribs, or similar. The tools may be used to deliver medications or diagnostic instruments or similar to cavity. Many other embodiments are possible without deviating from the spirit and scope of the invention. These other embodiments are intended to be included within the scope of the present invention, which is set forth in the following claims. | Methods and tools that insert implants for the treatment of snoring and sleep apnea in a cavity created in the patient's tissue are disclosed. Some tools and methods can additionally verify that the cavity has proper cavitation depth and does not have unwanted perforations. The tools include: a sheath having a substantially flat portion for housing an implant, the sheath having a distal end and a proximal end, the sheath having a hollow collar on the proximal end, an insertion depth mark near the distal end, and a slit on the distal end, the slit being in fluid communication with the hollow collar; a substantially rigid pusher configured to be disposed within and in slidable engagement with the sheath, the pusher having a distal end and a proximal end, the pusher having a rigid body having an outside diameter for slidably engaging with the hollow collar of the sheath, a tip on the distal end for engaging a proximal end of an implant, and a lumen extending from said proximal side to said distal side of said rigid body, the lumen configured for fluid communication with a syringe at the proximal end and in fluid communication with the sheath at the distal end. | 0 |
BACKGROUND
[0001] Medium and heavy duty vehicles, as well as some light duty pickup trucks and sport utility vehicles, are commonly built using the basic and longstanding design of a vehicle frame supporting a separate body, running gear, and powertrain. Often, during the process of manufacturing the vehicle certain components, such as battery boxes, fuel tank assemblies, fluid reservoirs, and exhaust supports are attached to the vehicle frame subsequent to its assembly. These components may even be added following installation of the running gear and powertrain, such that it is important that the vehicle undergoing construction remain upright. Because of this, and because the components to be attached to the vehicle frame are usually quite heavy, various techniques have been devised to assist in their installation.
[0002] Examples of techniques or devises used to temporarily support components to be attached to a vehicle frame during the process of installation include powered lifts or hoists, or fixtures either attached to the vehicle frame or located along the vehicle assembly line. Alternately, smaller brackets, referred to as alignment brackets, are sometimes first attached to the vehicle frame, and followed by attaching the heavier components to the alignment brackets. These alignment brackets may be provided with features that allow the heavier components to remain in place prior to installation and tightening of any fasteners. It is even known to use one or more shoulder bolts in conjunction with keyhole features located in the component to be attached to the vehicle frame, such that the keyhole is placed over the shoulder bolt and the component is left hanging thereupon, until such time as any fasteners may be installed and tightened.
[0003] Each of the prior art techniques or devises have one or more drawbacks. Powered lifts or hoists are expensive and add operator time to the cost of manufacturing the vehicle. Fixtures similarly must be designed, built, handled, maintained, removed, and stored, each of which activities add to the cost of the vehicle being manufactured. Alignment brackets add considerably to the cost of manufacturing a vehicle having a vehicle frame, as they add the cost of usually at least two additional pieces, including the associated manufacturing, engineering, and logistics costs. Also, alignment brackets add to stack-up of manufacturing tolerances and increase the number of potentially fallible joints in the assembly.
SUMMARY
[0004] It is advantageous in the design and construction of vehicles having vehicle frames to provide a way to temporarily support any heavy components that may need to be installed subsequent to assembly of the vehicle frame. It is further advantageous that any technique or devise that is provided to fulfill this function be inexpensive and easy to install. It has been noted that prior art shoulder bolts and keyhole features have effectively if inefficiently fulfilled this function in such manner. The key drawback to prior art shoulder bolts and keyhole features is the fact that once the remaining conventional fasteners that attach the heavy component to the vehicle frame are tightened, the prior art shoulder bolts and keyhole features contribute nothing to the integrity of the joint. Therefore, once they have done their job at the time of installation, prior art shoulder bolts and keyhole features are entirely redundant and unnecessary.
[0005] An ineffective alternative to the shoulder bolt and keyhole is to use a conventional nut and non-shoulder bolt in conjunction with a keyhole feature in the component to be attached to the vehicle frame. The conventional nut and non-shoulder bolt is installed loosely, such that the keyhole feature may be placed over it and then tightened. The reason that this method is ineffective is because when the keyhole feature in the component to be attached to the vehicle frame is moved over the conventional nut and non-shoulder bolt, the nut and bolt tends to catch on the edges of the keyhole feature and slide inwards toward the vehicle frame. Thus, the installation becomes an awkward affair requiring more than one individual to accomplish.
[0006] One embodiment of the present invention solves the problems of the prior art by providing a shoulder bolt that works in conjunction with a keyhole in a component to be attached to the vehicle frame, which shoulder bolt will not tend to slide inward toward the vehicle frame when the keyhole feature is placed over it, and which may have a nut fully tightened upon it, thereby becoming a full contributing member to the integrity of the joint. An embodiment of the present invention may be a bolt having a sacrificial spacer, such as shoulder made from an easily compressible, deformable, or extrudable material. The easily compressible, deformable, or extrudable material may be a polymer, rubber, soft plastic, wax, or the like. An alternate embodiment of the present invention may have a sacrificial spacer in the form of shoulder made from a crushable material, such as loosely sintered powder metal or porous ceramic. Yet another embodiment of the present invention may have a separate sacrificial spacer in the form of a sleeve made from an easily compressible, deformable, extrudable, or crushable material, which separate sacrificial sleeve functions in place of a sacrificial shoulder upon the bolt. Another embodiment may have an easily compressible, deformable, extrudable, or crushable sacrificial spacer in the form of a shoulder attached to the nut, such that the bolt extends from within the vehicle frame, and the sacrificial shoulder attached to the nut overlaps a portion of the bolt, thereby functioning in the same manner as an easily compressible, deformable, extrudable, or crushable sacrificial shoulder upon the bolt.
[0007] In use, one or more shoulder bolts having a sacrificial spacer in the form of a shoulder made from an easily compressible, deformable, extrudable, or crushable material are installed into one or more holes in the vehicle frame. One or more compatible nuts are threaded onto the one or more sacrificial shoulder bolts sufficiently tightly to hold the sacrificial shoulder bolts in place, yet not tightly enough to compress or crush the easily compressible, deformable, extrudable, or crushable material of which the sacrificial shoulder is made. Keyhole features provided in the component to be attached to the vehicle frame are placed over the head of the sacrificial shoulder bolts, allowing the component to hang from the sacrificial shoulder bolts, while the sacrificial shoulders made from an easily compressible, deformable, extrudable, or crushable material prevent the sacrificial shoulder bolts from catching on the edges of the keyhole features and being pushed back into the holes in the vehicle frame. Any remaining conventional fasteners affixing the component to be attached to the vehicle frame may then be installed and tightened. Finally, the nuts and shoulder bolts having sacrificial shoulders made from easily compressible, deformable, extrudable, or crushable materials are fully tightened. The sacrificial shoulders then either crush or extrude into the slots and clearances of the keyhole feature, allowing the shoulder bolts to become a fully contributing member to the integrity of the joint.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 —Vehicle having body, chassis, vehicle frame, and component to be attached to vehicle frame.
[0009] FIG. 2 —Component to be attached to vehicle frame.
[0010] FIG. 3 —Bolt with easily compressible, deformable, extrudable, or crushable sacrificial shoulder.
[0011] FIG. 4 —Bolt and easily compressible, deformable, extrudable, or crushable sacrificial sleeve.
[0012] FIG. 5 —Bolt and nut having easily compressible, deformable, extrudable, or crushable sacrificial shoulder.
[0013] FIG. 6 —Exploded view of component to be mounted to frame using keyhole feature and shoulder bolt having easily compressible, deformable, extrudable, or crushable sacrificial shoulder.
[0014] FIG. 7 —Exploded view of component to be mounted to frame using keyhole feature and bolt with easily compressible, deformable, extrudable, or crushable sacrificial sleeve.
[0015] FIG. 8 —Exploded view of component to be mounted to frame using keyhole feature and nut with easily compressible, deformable, extrudable, or crushable sacrificial shoulder.
[0016] FIG. 9 —Bolt with easily compressible, deformable, extrudable, or crushable sacrificial shoulder, installed.
DETAILED DESCRIPTION OF THE INVENTION
[0017] FIG. 1 shows a vehicle 101 having a body 102 and a chassis 103 . The chassis 103 is comprised of a vehicle frame 104 . One or more components 105 are attached to the vehicle frame 104 .
[0018] FIG. 2 shows a component 105 intended to be attached to a vehicle frame 104 (not shown). The component 105 is provided with keyhole features 106 having slots 117 and clearances 118 , as well as regular mounting holes 108 . For illustrative purposes, conventional fasteners 107 are shown inserted in one of the keyhole features 106 and one of the regular mounting holes 108 , although such conventional fasteners 107 would not actually be inserted into the keyhole features 106 or the regular mounting holes 108 prior to installation of the component 105 onto the vehicle frame 104 (not shown).
[0019] FIG. 3 shows a bolt 109 having an easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 . The easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 is located between the threaded portion of the body 111 and the head of the bolt 112 , and is of greater diameter than the nominal diameter of the threaded portion of the body 111 and of lesser diameter than the nominal diameter of the head of the bolt 112 . The easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 may be made from polymer, rubber, soft plastic, wax, loosely sintered powder metal, or porous ceramic material, or any like material which qualifies as easily compressible, deformable, extrudable, or crushable. The easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 may be bonded to, overmolded upon, or mechanically attached to the bolt 109 .
[0020] FIG. 4 shows a bolt 109 and an easily compressible, deformable, extrudable, or crushable sacrificial sleeve 113 . In use, the easily compressible, deformable, extrudable, or crushable sacrificial sleeve 113 is inserted over the bolt 109 so that it performs the same function as the easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 on the bolt 109 shown in FIG. 3 . The easily compressible, deformable, extrudable, or crushable sacrificial sleeve 113 shown in FIG. 4 is again of greater diameter than the nominal diameter of the threaded portion of the body 111 and of lesser diameter than the nominal diameter of the head of the bolt 112 , and is again made from polymer, rubber, soft plastic, wax, loosely sintered powder metal, or porous ceramic material, or any like material which qualifies as easily compressible, deformable, extrudable, or crushable.
[0021] FIG. 5 shows a bolt 109 and a nut 114 having an easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 . The bolt 109 is a conventional bolt having a threaded portion 111 and a head 112 . The easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 is attached to the nut 114 , and aligned axially with the threaded bore 115 of the nut 114 . The easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 is of greater diameter than the nominal diameter of the threaded portion of the body 111 of the bolt 109 and of lesser diameter than the nominal diameter of the nut 114 , and is again made from polymer, rubber, soft plastic, wax, loosely sintered powder metal, or porous ceramic material, or any like material which qualifies as easily compressible, deformable, extrudable, or crushable. The easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 may be bonded to, overmolded upon, or mechanically attached to the nut 114 .
[0022] FIG. 6 shows a vehicle frame 104 and a component 105 to be mounted to the vehicle frame 104 in an exploded view. Bolts 109 having easily compressible, deformable, extrudable, or crushable sacrificial shoulders 110 are inserted into frame mounting holes 116 . Nuts 114 are threaded onto the bolts 109 having easily compressible, deformable, extrudable, or crushable sacrificial shoulders 110 , and are tightened sufficiently to retain the bolts 109 , but not tightly enough to compress or crush the easily compressible, deformable, extrudable, or crushable sacrificial shoulders 110 . The component 105 to be mounted to the vehicle frame 104 is placed such that the keyhole features 106 having slots 117 and clearances 118 pass over the heads 112 of the bolts 109 , and rest upon the easily compressible, deformable, extrudable, or crushable sacrificial shoulders 110 , thereby temporarily supporting the component 105 . Conventional fasteners 107 are then installed through regular mounting holes 108 (not visible in view) and through frame mounting holes 116 and are fully tightened. The nuts 114 upon the bolts 109 having easily compressible, deformable, extrudable, or crushable sacrificial shoulders 110 are then fully tightened, such that the easily compressible, deformable, extrudable, or crushable sacrificial shoulders 110 either crush or extrude into the unoccupied slots 117 and clearances 118 of the keyhole features 106 , allowing the bolts 109 to become a fully contributing member to the integrity of the mounting of the component 105 to the vehicle frame 104 .
[0023] FIG. 7 shows a vehicle frame 104 and a component 105 to be mounted to the vehicle frame 104 in an exploded view, similar to the vehicle frame 104 and component 105 shown in FIG. 6 . Easily compressible, deformable, extrudable, or crushable sacrificial sleeves 113 are placed over bolts 109 , which bolts 109 are inserted into frame mounting holes 116 . Nuts 114 are threaded onto the bolts 109 , and are tightened sufficiently to retain the bolts 109 , but not tightly enough to compress or crush the easily compressible, deformable, extrudable, or crushable sacrificial sleeves 113 . The component 105 to be mounted to the vehicle frame 104 is placed such that the keyhole features 106 having slots 117 and clearances 118 pass over the heads 112 of the bolts 109 , and rest upon the easily compressible, deformable, extrudable, or crushable sacrificial sleeves 113 , thereby temporarily supporting the component 105 . Conventional fasteners 107 are then installed through regular mounting holes 108 (not visible in view) and through frame mounting holes 116 and are fully tightened. The nuts 114 upon the bolts 109 are then fully tightened, such that the easily compressible, deformable, extrudable, or crushable sacrificial sleeves 113 either crush or extrude into the unoccupied slots 117 and clearances 118 of the keyhole features 106 , allowing the bolts 109 to become a fully contributing member to the integrity of the mounting of the component 105 to the vehicle frame 104 .
[0024] FIG. 8 shows a vehicle frame 104 and a component 105 to be mounted to the vehicle frame 104 in an exploded view, similar to the vehicle frames 104 and components 105 shown in FIG. 6 and FIG. 7 . Bolts 109 are inserted into frame mounting holes 116 from within the vehicle frame 104 . Nuts 114 having easily compressible, deformable, extrudable, or crushable sacrificial shoulders 110 are threaded onto the bolts 109 , and are tightened sufficiently to retain the bolts 109 , but not tightly enough to compress or crush the easily compressible, deformable, extrudable, or crushable sacrificial shoulders 110 of the nuts 114 . The component 105 to be mounted to the vehicle frame 104 is placed such that the keyhole features 106 having slots 117 and clearances 118 pass over the nuts 114 , and rest upon the easily compressible, deformable, extrudable, or crushable sacrificial shoulders 110 , thereby temporarily supporting the component 105 . Conventional fasteners 107 are then installed through regular mounting holes 108 (not visible in view) and through frame mounting holes 116 and are fully tightened. The nuts 114 having easily compressible, deformable, extrudable, or crushable sacrificial shoulders 110 upon the bolts 109 are then fully tightened, such that the easily compressible, deformable, extrudable, or crushable sacrificial shoulders 110 either crush or extrude into the unoccupied slots 117 and clearances 118 of the keyhole features 106 , allowing the bolts 109 to become a fully contributing member to the integrity of the mounting of the component 105 to the vehicle frame 104 .
[0025] FIG. 9 shows a section of a vehicle frame 104 and a portion of the component 105 to be mounted to the vehicle frame 104 . The keyhole feature 106 having slots 117 and a clearance 118 has been placed over the head 112 of the bolt 109 , and the nut 114 (not visible) has been fully tightened. The easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 is shown extruded from beneath the head 112 of the bolt 109 and at least partially into the slot 117 or clearance 118 . Alternately, if the easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 is instead crushed, the crushed remnants of the easily compressible, deformable, extrudable, or crushable sacrificial shoulder 110 may flow into the slot 117 or clearance 118 of the keyhole feature 106 .
[0026] While specific embodiments have been described in detail in the foregoing detailed description and illustrated in the accompanying drawings, those with ordinary skill in the art will appreciate that various permutations of the invention are possible without departing from the teachings disclosed herein. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof. Other advantages to a vehicle equipped with a component mounting system utilizing keyhole features and easily compressible, deformable, extrudable, or crushable sacrificial spacers in the form of shoulder bolts, sleeves, or shoulder nuts may also be inherent in the invention, without having been described above. | A mounting system for a component to be mounted to a vehicle frame is provided utilizing keyhole features in the component, and fasteners having sacrificial spacers in the vehicle frame. The sacrificial spacers upon the fasteners prevent them from being pushed into the vehicle frame when the component having keyhole features is placed over them. Once the keyhole features have been placed over the fasteners having sacrificial spacers, the fasteners having sacrificial spacers may be fully tightened, thereby fully contributing to the integrity of the resulting joint. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation of U.S. patent application Ser. No. 13/825,749, filed on Apr. 26, 2013, which is a National Stage Entry of PCT/EP2011/065350, filed on Sep. 6, 2011, which claims priority from EP 10179213.3, filed on Sep. 24, 2010.
FIELD OF THE INVENTION
The present invention relates to a process for producing isoprene from iso-butanol, preferably obtained from renewable resources. Isoprene is used as a basic chemical starting material for various chemical products and elastomers. The limited supply and increasing cost of crude oil has prompted the search for alternative processes for producing hydrocarbon products such as isoprene. Iso-butanol can be obtained by fermentation of carbohydrates or by condensation of lighter alcohols, obtained by fermentation of carbohydrates. Made up of organic matter from living organisms, biomass is the world's leading renewable energy source.
BACKGROUND OF THE INVENTION
Conventionally isoprene is produced by extraction from pyrolysis gasoline, which is a byproduct of steamcracking of naphtha. The yield is typically very low, of the order of 1-3% of the produced ethylene. Hence it is difficult to justify this capital-intensive technology for only a small production capacity of isoprene. The process to isolate isoprene from pyrolysis gasoline consist first in the removal of cyclopentadiene by dimerisation and distillation. Next the pipirylenes are separated by superfractionation. The last steps consist in an extractive distillation using a solvent. Moreover the quality of isoprene obtained from pyrolysis gasoline is hard to guarantee as the specifications with respect to cyclopentadiene and pipirylenes are very severe and these compounds are plentiful present in the same pyrolysis gasoline. As pyrolysis gasoline contains only small amounts of isoprene (10-20%), a lot of byproducts (dicyclopentadiene and pipirylene) are produced according to the same laborious manner while their market value is not necessary in line with the evolution of the market value of isoprene.
Recently, there is a tendency to shift to lighter feedstock for steamcracking feeding. Most new steamcrackers are using ethane as feedstock that does not produce pyrolysis gasoline as byproduct. Also many naphtha-based steamcrackers are shifting to lighter feedstock because of its abundant availability and competitive advantage.
Other routes to produce isoprene are the isolation of isoamylenes from refinery and petrochemical cuts and perform a dehydrogenation into isoprene. This process is typically done over iron oxide catalyst promoted with potassium compounds at temperatures above 600° C. in presence of water steam and reduced pressure. As this reaction is limited by a thermodynamic equilibrium, only partial conversions can be obtained.
Isoprene can also be produced from isopentane by a double dehydrogenation.
In still another process, isoprene is produced by a two-step process. In the first step iso-butene, tertiary-butanol, di-t-butyl ether, methyl-t-butyl ether or ethyl-t-butyl ether is condensed with two molecules of formaldehyde to form dimethyloxirane. The dimethyloxirane is separated and purified. In the second step the dimethyloxirane is decomposed under appropriate conditions into isoprene and one molecule of formaldehyde. An improvement on the latter two-step process is a one-step process, in which iso-butene, tertiary-butanol, di-t-butyl ether, methyl-t-butyl ether or ethyl-t-butyl ether is directly reacted with formaldehyde into isoprene.
The U.S. Pat. No. 4,511,751 describes a process for producing isoprene in good yield. The process is characterized in that iso-butene and/or tertiary butanol and a formaldehyde source are fed, together with water, into an acidic aqueous solution continuously or intermittently while maintaining the reaction pressure in an adequate range and at the same time distilling off the product isoprene and unreacted starting materials, together with water, from the reaction zone.
The U.S. Pat. No. 4,593,145 describes a process for producing isoprene, characterized in that an alkyl-t-butyl ether and a formaldehyde source are fed, together with water, into an acidic aqueous solution continuously or intermittently while maintaining the reaction pressure in an adequate range and at the same time distilling off the product isoprene, unreacted starting materials, iso-butene and tertiary butanol, together with water, from the reaction zone.
EP106323 describes a process for producing isoprene by reacting iso-butene and/or tertiary butanol and/or an alkyl tertiary butyl ether which gives iso-butene and/or tertiary butanol under the reaction conditions with formaldehyde in an acidic aqueous solution, under such conditions (a) that the acidic aqueous solution is present in the reaction zone, (b) that iso-butene and/or tertiary butanol and/or the alkyl tertiary butyl ether, a formaldehyde source and water are fed to said reaction zone continuously or intermittently, and (c) that isoprene, water, unreacted starting materials and other low-boiling components are distilled off from said reaction zone, wherein a glycol ether is added, in an amount of 5 to 15 percent by weight, to the acid aqueous solution. It is specified that the presence of a solvent in the reactor improves the solubility of iso-butene in the aqueous phase and hence the contact with the acid catalyst that is substantially dissolved in the aqueous solution.
EP 1 614 671 A1 describes process for producing isoprene, which includes continuously or intermittently supplying iso-butene and/or t-butanol, formaldehyde and water into an acidic aqueous solution, and reacting the reaction mixture while distilling away a mixture containing produced isoprene, water, unreacted starting materials and other low boiling point components from this reaction mixture to the outside of the reaction system, wherein the reaction is carried out while controlling the concentration of high boiling point byproducts, which is produced and accumulated in the reaction mixture, to fall within the range of 0.5-40 mass %.
EP 2 157 072 A1 describes a method to obtain isoprene by way of liquid-phase interaction between trimethyl carbinol (also known as t-butanol, or its water solutions) and formaldehyde (or its source substances) in the presence of acidic catalyzer water solution; this can be made in one or several contacting stages, with use (at the final contacting stage) of separation reactor containing a heat supply zone, a reaction zone and a separation zone, with reaction products and water taken, out of the separation zone, in the form of a vapor flow to be subsequently cooled down, condensed and separated and with liquid flow of the catalyzer water solution put out for extraction and, after this, put back into the heating zone. As it goes from the reaction zone into the separation zone, the reactive flow is throttled. In the reaction zone, temperature is maintained at the level of 140-180° C., while pressure is 8-25 atmospheres; in the separation zone, pressure is 1.2-9.5 atmospheres. The separation reactor contains two or three separation zones. The balance quantity of water is put out of catalyzer water solution, which is circulating along the circuit, by way of its evaporation as the flow is throttled into the separation zone (zones) during regulation of the quantity of the circulating liquid phase in the interval of 0.2-6.0 parts of the total reaction zone area.
US 2010 0216958 A1 relates, in one embodiment, to a method of preparing butadiene comprising (a) providing an alcohol mixture comprising one or more butanols; (b) contacting the alcohol mixture with a dehydration catalyst, thereby forming an olefin mixture comprising one or more linear butenes and isobutene; (c) contacting the olefin mixture of step (b) with a dehydrogenation catalyst, thereby forming a di-olefin mixture comprising butadiene and isobutene; and (d) isolating butadiene from the di-olefin mixture of (c).
In another embodiment, it relates to a method of preparing isoprene comprising (a) providing an olefin mixture comprising one or more pentenes, with the proviso that at least a portion of the olefin mixture comprises one or more methylbutenes; (b) contacting the olefin mixture of (a) with a dehydrogenation catalyst, thereby forming a mixture comprising isoprene; and (c) isolating isoprene from the mixture of (b).
In still another embodiment, it relates to a method of preparing monomers, comprising: (a) providing an olefin mixture comprising one or more linear butenes and isobutene; (b) contacting the olefin mixture of step (a) with a dehydrogenation catalyst, thereby forming a di-olefin mixture comprising butadiene and isobutene; (c) isolating isobutene from the mixture of step (b); and (dl)) converting the isobutene to methyl t-butyl ether, ethyl t-butyl ether, isooctane, methacrolein, methyl methacrylate, butyl rubber, butylated hydroxytoluene, or butylated hydroxyanisole.
In still other embodiments, it relates to methods for preparing isobutene or isoprene as described herein, wherein the olefin mixture is prepared by dehydration of a renewable alcohol mixture comprising one or more renewable C 4 or C 5 alcohols.
Iso-butanol (2-methyl-1-propanol) has historically found limited applications and its use resembles that of 1-butanol. It has been used as solvent, diluents, wetting agent, cleaner additive and as additive for inks and polymers. Recently, iso-butanol has gained interest as fuel or fuel component as it exhibits a high octane number (Blend Octane R+M/2 is 102-103) and a low vapor pressure (RVP is 3.8-5.2 psi).
Iso-butanol is often considered as a byproduct of the industrial production of 1-butanol (Ullmann's encyclopedia of industrial chemistry, 6 th edition, 2002). It is produced from propylene via hydroformylation in the oxo-process (Rh-based catalyst) or via carbonylation in the Reppe-process (Co-based catalyst). Hydroformylation or carbonylation makes n-butanal and iso-butanal in ratios going from 92/8 to 75/25. To obtain iso-butanol, the iso-butanal is hydrogenated over a metal catalyst. Iso-butanol can also be produced from synthesis gas (mixture of CO, H 2 and CO 2 ) by a process similar to Fischer-Tropsch, resulting in a mixture of higher alcohols, although often a preferential formation of iso-butanol occurs (Applied Catalysis A, general, 186, p. 407, 1999 and Chemiker Zeitung, 106, p. 249, 1982). Still another route to obtain iso-butanol, is the base-catalysed Guerbet condensation of methanol with ethanol and/or propanol (J. of Molecular Catalysis A: Chemical 200, 137, 2003 and Applied Biochemistry and Biotechnology, 113-116, p. 913, 2004).
Recently, new biochemical routes have been developed to produce selectively iso-butanol from carbohydrates. The new strategy uses the highly active amino acid biosynthetic pathway of microorganisms and diverts its 2-keto acid intermediates for alcohol synthesis. 2-Keto acids are intermediates in amino acid biosynthesis pathways. These metabolites can be converted to aldehydes by 2-keto-acid decarboxylases (KDCs) and then to alcohols by alcohol dehydrogenases (ADHs). Two non-native steps are required to produce alcohols by shunting intermediates from amino acid biosynthesis pathways to alcohol production (Nature, 451, p. 86, 2008 and US patent 2008/0261230). Recombinant microorganisms are required to enhance the flux of carbon towards the synthesis of 2-keto-acids. In the valine biosynthesis 2-ketoisovalerate is on intermediate. Glycolyse of carbohydrates results in pyruvate that is converted into acetolactate by acetolactate synthase. 2,4-dihydroxyisovalerate is formed out of acetolactate, catalysed by isomeroreductase. A dehydratase converts the 2,4-dihydroxyisovalerate into 2-keto-isovalerate. In the next step, a keto acid decarboxylase makes isobutyraldehyde from 2-keto-isovalerate. The last step is the hydrogenation of isobutyraldehyde by a dehydrogenase into iso-butanol.
Of the described routes towards iso-butanol above, the Guerbet condensation, the synthesis gas hydrogenation and the 2-keto acid pathway from carbohydrates are routes that can use biomass as primary feedstock. Gasification of biomass results in synthesis gas that can be converted into methanol or directly into iso-butanol. Ethanol is already at very large scale produced by fermentation of carbohydrates or via direct fermentation of synthesis gas into ethanol. So methanol and ethanol resourced from biomass can be further condensed to iso-butanol. The direct 2-keto acid pathway can produce iso-butanol from carbohydrates that are isolated from biomass. Simple carbohydrates can be obtained from plants like sugar cane, sugar beet. More complex carbohydrates can be obtained from plants like maize, wheat and other grain bearing plants. Even more complex carbohydrates can be isolated from substantially any biomass, through unlocking of cellulose and hemicellulose from lignocelluloses.
It is the object of the present invention to use of iso-butanol for the production of isoprene by condensation with formaldehyde. Without willing to be bound to any theory, it is believed that the t-butyl-carbocation is the reactive specie that attacks formaldehyde and that its presence in the aqueous solution where resides also the acid catalyst and the formaldehyde is essential for high reaction rates for the selective condensation reaction. The decomposition of iso-butanol is significantly slower than that of t-butanol under the reaction conditions and as a consequence iso-butanol will serve as efficient solvent that improves the solubility of iso-butene and enhances the presence of t-butyl-carbocations in the aqueous phase. t-Butanol tends to dehydrate too fast so that most of the iso-butene escapes from the aqueous reaction medium and hence a lot of recycling is required.
The following reactions occur under the reaction conditions:
Dehydration:
Condensation:
It is the object of the present invention to produce isoprene by reacting formaldehyde with an iso-butene producing alcohol comprising iso-butanol.
BRIEF SUMMARY OF THE INVENTION
The present invention is a process to make isoprene comprising:
a) providing a reaction zone comprising an acidic aqueous solution,
b) introducing, continuously or intermittently, in said reaction zone a mixture comprising (I) isobutanol and optionally (ii) t-butanol or an iso-butene precursor which is not isobutanol and not t-butanol or iso-butene or any combination of two or three of these (ii) components, an aqueous solution of formaldehyde,
c) operating said reaction zone at conditions effective to dehydrate isobutanol and optionally (ii) t-butanol and optionally the iso-butene precursor to iso-butene and produce isoprene by reaction of formaldehyde and iso-butene while distilling away a mixture comprising produced isoprene, water, unreacted starting materials and other low boiling point components from this reaction zone to the outside of the reaction zone.
An isobutene precursor which is not isobutanol and not t-butanol is a component which is decomposed to isobutene under the above reaction conditions. One can cite ethers.
In another embodiment isobutanol provides 10% or more of the iso-butene for the isoprene synthesis.
In another embodiment isobutanol provides 20% or more of the iso-butene for the isoprene synthesis.
In another embodiment isobutanol provides 30% or more of the iso-butene for the isoprene synthesis.
In another embodiment isobutanol provides 40% or more of the iso-butene for the isoprene synthesis.
In another embodiment isobutanol provides 50% to 100% of the iso-butene for the isoprene synthesis.
DETAILED DESCRIPTION OF THE INVENTION
As regards the feedstock, iso-butanol whereby, advantageously, at least 25 mole % of the carbon is obtained from renewable resources, is a part of the feedstock of the presence invention. Iso-butanol can be produced (i) by Guerbet condensation of methanol with ethanol or propanol, (ii) by direct hydrogenation of carbon monoxide with hydrogen or (iii) by direct biosynthesis via 2-Keto acids, intermediates in amino acid biosynthesis pathways or (iv) by hydroformylation of propylene with a mixture of carbon monoxide and hydrogen. The iso-butene reacting with formaldehyde comes for at least 10% from iso-butanol; the remaining part of the iso-butene reacted with formaldehyde comes from t-butanol, other iso-butene precursor or from fresh iso-butene as feedstock. As regards the iso-butene precursor which is not the isobutanol and not the t-butanol one can cite methyl-t-butyl ether, di-isobutyl-ether, di-t-butyl-ether, ethyl-t-butyl ether and the like, which are decomposed to iso-butene under reaction conditions.
The formaldehyde can be any commercially available form of formaldehyde, most preferable an aqueous solution of formaldehyde.
As regards of the condensation reaction, reacting iso-butene with formaldehyde to make isoprene is know per se. Iso-butene reacts with formaldehyde to give 4,4-dimethyl-m-dioxane which decomposes to isoprene. Said route is described, by way of example, in GB 1370899 and U.S. Pat. No. 3,972,955, the content of which is incorporated by reference in the present application. By way of example, EP 106323 A1, EP 1614671 A1 and EP 2157072 A1, the content of which is incorporated by reference in the present application, describe a route in which iso-butene or t-butanol is reacted with formaldehyde in acidic aqueous medium to produce isoprene. The operating conditions described in the above cited prior art can be used in the present invention.
In an embodiment the operating conditions and the catalyst are optimised such that directly isoprene is produced. The process is catalysed by acid catalysts. The operating conditions are chosen such that the isoprene is removed as quickly as possible form the reaction mixture upon its formation. This is generally being done by vaporisation of the formed isoprene together with non-converted iso-butene and water vapour. An appropriate control of the reactor pressure will determine the boiling off of the reaction products and other entrained components present in the reactor. The reactor pressure is from 7 to 18 bars, preferably from 8 to 15 bars gauge. The reaction temperature is from 140 to 240° C., preferably from 160 to 220° C. These vapours are condensed and the isoprene is isolated from the remaining iso-butene and an aqueous phase. The iso-butene (as fresh feed or as dehydration product of iso-butanol or t-butanol or coming from the iso-butene precursor), iso-butene precursor, iso-butanol and t-butanol can be recycled back into the conversion reactor. So the t-butyl-moieties in the reactor are coming from fresh feed composed of iso-butanol, t-butanol, iso-butene precursor and iso-butene, although the t-butyl-moiety can also originate from the recycled iso-butene, recycled t-butanol, recycled iso-butene precursor and recycled iso-butanol. The isolated isoprene is typically very pure after distillation as no other hydrocarbons with five carbons can be produced out of iso-butanol/t-butanol/iso-butene and formaldehyde. Typical byproducts are oligomers of isoprene and formaldehyde that are easy to separate from isoprene.
The catalyst may be any acid, homogeneous or heterogeneous. It is preferred that the catalyst is a high boiling acid that remains in the aqueous phase of the reactor and does not vaporises with the isoprene out of the reactor vessel. Examples of liquid homogeneous catalysts are sulphuric acid, hydrosulfuric acid, phosphoric acid, monohydrophosphoric acid, dihydrophosphoric acid, boric acid, nitric acid, methanesulfonic acid, para-toluyl-sulfonic acid, heteropolyacids etc. Heterogeneous acids may also be use, among others sulfonated crosslinked divinylstyrene, sulfonated polyfluorohydrocarbons, sulfonated amorphous silica's, sulfonated mesoporous silica's, sulfonated zirconia's, supported heteropolyacids, zeolites etc.
The condensation reaction can be carried out in various reactor configurations: (i) batch stirred tank reactors, (ii) continuous stirred tank reactors, (iii) jet type or siphon type circulating reactors and (iv) bubble column reactors. It is essential that a good mixing of the reactants occurs as otherwise the local ratio of t-butyl-moieties to formaldehyde might be non-optimal and hence resulting in different reactions pathways resulting in loss of selectivity. The molar ratio of t-butyl-moiety (as the molar sum of fresh iso-butanol, t-butanol, iso-butene precursor or iso-butene) send as fresh feed to the reactor to formaldehyde send as fresh feed to the reactor is from 0.5 to 2, preferably close to 1. The molar ratio of t-butyl-moiety (as the molar sum of fresh iso-butanol, fresh t-butanol, fresh iso-butene, fresh iso-butene precursor, recycled iso-butanol, recycled t-butanol, recycled iso-butene precursor or recycled iso-butene) to formaldehyde in the reactor is from 1 to 18, preferably from 1.5 to 5, most preferably from 2 to 4. Should the iso-butene precursor leads to 2 or 3 moles iso-butene, the number of moles of isobutene precursor has to be multiply by 2 or 3 in the above ratios of t-butyl-moiety to formaldehyde. | A process to make isoprene may include providing a reaction zone containing an acidic aqueous solution. The process may include introducing, continuously or intermittently, in the reaction zone a mixture containing isobutanol and an aqueous solution of formaldehyde. The process may include operating the reaction zone at conditions effective to dehydrate isobutanol to iso-butene, and produce isoprene by reaction of formaldehyde and iso-butene, while distilling away a mixture containing produced isoprene and water. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a §371 US National Stage Application of International Application No. PCT/EP2013/053257 filed on Feb. 19, 2013, claiming the priority of European Patent Application No. 12156180.7 filed on Feb. 20, 2012 and European Patent Application No. 12160499.5 filed on Mar. 21, 2012.
FIELD OF THE INVENTION
[0002] The invention relates to a high strength bake-hardenable low density steel and to a method for producing said steel.
BACKGROUND OF THE INVENTION
[0003] In the continuing efforts to reduce the carbon emissions of vehicles the steel industry, together with the car manufacturers, continue to strive to steels which allow weight reduction without affecting the processability of the steels and the safety of the finished product. To meet future CO 2 -emission requirements, the fuel consumption of automobiles has to be reduced. One way towards this reduction is to lower the weight of the car body. A steel with a low density and high strength can contribute to this. At the same thickness, the use of a low density steel reduces the weight of car components. A problem with known high strength steels is that their high strength compromises the formability of the material during forming of the sheet into a car component.
[0004] Ordinary high strength steels, for example dual phase steels, allow use of thinner sheets and therefore weight reduction. However, a thinner part will have a negative effect on other properties such as stiffness, crash - and dent resistance. These negative effects can only be solved by increasing the steel thickness, thus negating the effect of the downgauging, or by changing the geometry of the component which is also undesirable.
SUMMARY OF THE INVENTION
[0005] It is an object of this invention to provide a low density steel with a high strength in the finished component combined with excellent formability prior to forming the car component.
[0006] It is also an object of this invention to provide a high strength steel with excellent stiffness and dent resistance.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0007] One or more of these objects can be reached by providing a ferritic steel strip or sheet comprising, in weight percent,
up to 0.01% C_total; up to 0.5 % Si; up to 1.0 % Mn; from 5 to up to 10% Al; up to 0.010% N; up to 0.019% Ti; up to 0.08% Nb; up to 0.1% Zr; up to 0.1% V; up to 0.01% S; up to 0.1% P; optionally between 5 and 50 ppm B; remainder iron and inevitable impurities; wherein C_solute=C_total
Minimum[X,Y] Maximum[Z,0] 12/93*Nb 12/91*Zr 12/51*V;
wherein
[0000] X=2*12/(2*32)*S;
[0000] Y=2*12/(4*48)*(Ti−48/14*N);
[0000] Z=12/48*(Ti−48/14*N−4*48/(2*32)*S);
wherein Minimum[X,Y]=lower value of X and Y and Minimum[X,Y]=zero if Y is negative; Maximum[Z,0]=higher value of zero and Z; and wherein C_solute is at least 0.0005 (5 ppm).
[0032] All percentages are in weight percent, unless otherwise indicated. For the sake of avoiding any misunderstanding, the formulae given above, when typed in in a commercial spreadsheet programme such as Microsoft Excel will result in the correct interpretation of the formulae. For instance 12/93*Nb is correctly interpreted as (12/93)*Nb as the skilled person will recognise the atomic masses of carbon (12) and Nb (93) in this formula. This is the same for the other numbers in the formulae (mutatis mutandis). So, superfluously:
[0000]
X
=
2
·
(
12
2
·
32
)
·
S
Y
=
2
·
(
12
4
·
48
)
·
(
Ti
-
(
(
48
14
)
·
N
)
)
Z
=
(
12
48
)
·
(
Ti
-
(
(
48
14
)
·
N
)
-
(
4
·
48
(
2
·
32
)
·
S
)
)
[0033] The steel according to the invention has a tailored chemical composition to allow the steel to contain carbon in solid solution (C_solute) after the annealing and optional galvanising step. This carbon in solid solution allows the steel to be bake-hardenable e.g. in a paint-baking cycle. The car component is formed from the steel coming of the mill, and the component is painted and baked after it has been formed into its final shape.
[0034] In addition, the steel according to the invention combines the good formability prior to forming a car component, i.e. before the paint-baking operation, with a higher strength after the paint-baking operation.
[0035] The inventors found that for the steel to be bake-hardenable in a paint baking cycle at least 5 ppm of solute carbon (C_solute) must be present in steel. At lower amounts of solute carbon the effect is negligible or not reproducible.
[0036] The level of solute carbon may also not exceed a critical upper value because the steel is preferably free from natural ageing. Natural ageing is the spontaneous ageing of a supersaturated solid solution at room temperature and involves a spontaneous change in the physical properties of the steel, which occurs on being held at atmospheric temperatures after hot- or cold rolling or after a final heat treatment, e.g. during transport to or storage at a customers prior to processing the strip. This natural ageing involves changes of the mechanical properties which are considered undesirable as they lead to unpredictable variations in processability during the forming of the car components. Also, the surface quality may be adversely affected due to the formation of so-called Luder-lines. Also, too high a carbon level in solid solution may result in a deterioration of the formability prior to bake-hardening.
[0037] For that reason a maximum value of 50 ppm of solute carbon is preferable. A more suitable maximum is 40 ppm of solute carbon (i.e. 0.004%).
[0038] In an embodiment of the invention C_solute is at least 0.0010 (10 ppm) and/or at most 0.0030 (30 ppm). This achieves a stable process and reproducible properties.
[0039] Nitrogen, in particularly free nitrogen (i.e. nitrogen in solid solution), is not desirable but unavoidable in steel making. Titanium can be optionally added to bound nitrogen into TiN. The large amount of aluminium in the steel can also ensure that all nitrogen is bound. This means that the matrix is substantially free of nitrogen in solid solution.
[0040] Boron is optionally added to the steel. Its presence is not mandatory, but it may help to suppress any tendency for secondary work embrittlement. If added, a minimum amount of 5 ppm boron is required.
[0041] In an embodiment of the invention the manganese content is at least 0.1%. In another embodiment the aluminium content is at least 6% and/or at most 9%, preferably at most 8%.
[0042] The steel is preferably calcium treated. The chemical composition may therefore also contain calcium in an amount consistent with a calcium treatment.
[0043] In the steels according to the invention the amount of carbon in solid solution is controlled by the addition of microalloying elements (Ti, Nb, V, Zr) in combination with excellent control of the total carbon content in the steel.
[0044] The amount of Ti or Nb should be strictly controlled. Too much titanium or niobium will combine with carbon to form carbides or, in the presence of sulphur, carbosulphides. As a consequence of this, no solute carbon is available and no bake-hardenability.
[0045] The amount of carbon in solid solution according to this invention is calculated by subtracting from the total carbon content C_total the precipitates comprising carbon as follows:
C_solute=C_total
Minimum[X,Y] Maximum[Z,0] 12/93*Nb 12/91*Zr 12/51*V;
wherein
[0000] X=2*12/(2*32)*S;
[0000] Y=2*12/(4*48)*(Ti-48/14*N);
[0000] Z=12/48*(Ti−48/14*N−4*48/(2*32)*S);
Wherein Minimum[X,Y]=lower value of X and Y and Minimum[X,Y]=zero if Y is negative; Maximum[Z,0]=higher value of zero and Z.
[0056] For the interpretation of these formulae see herein above. The addition of Ti is beneficial for binding nitrogen, but not strictly necessary. Up to 0.019% Ti can be added into the steel, mainly to bind nitrogen into TiN and secondarily to control the amount of solute carbon. The titanium content must 0.019% or lower, e.g. at most 0.018% or 0.015% or even at most 0.012%.
[0057] If titanium is added as an alloying element, a suitable minimum value for the titanium content is 0.005%. If added, then a suitable minimum value for Nb is 0.008%. If added, then for V and Zr suitable minimum values are 0.002 and 0.004 respectively.
[0058] According to a preferable embodiment the composition of the ferritic steel according to the invention has a base composition of (in weight percent),
up to 0.01% C_total; up to 0.5 % Si; up to 1.0 % Mn; from 5 to up to 10 % Al; up to 0.010 % N; up to 0.08% Nb; up to 0.1% Zr; up to 0.1% V; up to 0.01% S; up to 0.1% P; optionally between 5 and 50 ppm B; remainder iron and inevitable impurities;
[0071] In this composition there is no titanium added to the steel, and any titanium present is an unavoidable impurity.
[0072] Titanium, as an alloying element or as an inevitable impurity, will first form TiN. If there is excess nitrogen, then the remaining nitrogen will be bound to aluminium. If there is excess titanium, then the remaining titanium will form Ti 4 C 2 S 2 until all titanium is consumed. The factor Minimum[X,Y] calculates how much carbon is consumed by the formation of Ti 4 C 2 S 2 after all free nitrogen was bound to TiN. If the calculation results in a negative value for Y, then the factor is to be set to zero.
[0073] If there is no titanium at all, no TiN or Ti 4 C 2 S 2 will be formed and then Minimum[X,Y] amounts to zero. The factor Maximum[Z,0] determines how much carbon is bound to titanium after accounting for the formation of TiN and Ti 4 C 2 S 2 .
[0074] The other three factors account for the formation of NbC, ZrC and VC, and thereby together with the factors Minimum[X,Y] and Maximum[Z,0] determine the amount of solute carbon in the steel.
[0075] By adding no or only small amounts of titanium and/or a specified amount of Nb, there will be sufficient solute carbon available for bake hardening. By controlling the level of solute carbon below 50 ppm, and preferably below 40 ppm, the steel according to the invention is bake hardenable and nature-aging resistant.
[0076] According to a second aspect, a method for producing a ferritic steel strip is provided comprising the steps of:
providing a steel slab or thick strip by:
continuous casting, or by thin slab casting, or by belt casting, or by strip casting;
optionally followed by reheating the steel slab or strip at a reheating temperature of at most 1250° C.; hot rolling the slab or thick strip and finishing the hot-rolling process at a hot rolling finishing temperature of at least 850° C.; coiling the hot-rolled strip at a coiling temperature of between 550 and 750° C.
[0085] In preferable embodiment the coiling temperature is at least 600° C. and/or the hot rolling finishing temperature is at least 900° C.
[0086] This hot-rolled strip can be subsequently further processed in a process comprising the steps of:
cold-rolling the hot-rolled strip at a cold-rolling reduction of from 40 to 90% to produce a cold-rolled strip; annealing the cold-rolled strip in a continuous annealing process with a peak metal temperature of between 700 and 900° C.; optionally galvanising the annealed strip in a hot-dip galvanising or electro-galvanising or a heat-to-coat process.
[0090] The hot-rolled strip is usually pickled and cleaned prior to the cold-rolling step. In an embodiment the peak metal temperature in the continuous annealing process is at least 750° C., preferably at least 800° C.
[0091] In an embodiment the cold rolling reduction is at least 50%.
[0092] In an embodiment the thickness of the hot-rolled strip is between 1 and 5 mm and/or the thickness of the cold-rolled strip is between 0.4 and 2 mm.
[0093] In an embodiment of the invention the hot-rolled strip is annealed in a continuous annealing step and optionally galvanised in a hot-dip galvanising step. The annealing may also take place in a so called heat-to-coat cycle. In a heat-to-coat cycle the hot-rolled steel is reheated to a temperature sufficient for performing the hot-dip galvanising, but not to a temperature as high as the conventional continuous annealing step. During the reheating the carbon, which may have precipitated during the slow cooling of the hot rolled coil after hot rolling is brought into solid solution again. After annealing and/or galvanising the steel has to be fast cooled to avoid precipitation of the carbon in solid solution. When using this galvanised steel sheet for producing a car component or other product by forming, followed by painting and baking, then the paint-baking also ensures the strength increase associated with the paint-baking cycle.
[0094] The invention is now further explained by means of the following, non-limiting examples.
[0095] Steels were produced and processed into cold-rolled steel sheets having a thickness of 1 mm. The hot rolled strip had a thickness of 3.0 mm. The chemical composition of the steels is given in Table 1.
[0000]
TABLE 1
Chemical composition
Steel
C
Al
Mn
N
Ti
Nb
S
C_solute
1
0.0020
7.0
0.20
0.0035
0.000
0.000
0.004
0.0020
I
2
0.0020
7.0
0.20
0.0030
0.010
0.000
0.004
0.0020
I
3
0.0040
7.0
0.20
0.0030
0.000
0.020
0.004
0.0014
I
3a
0.0040
6.9
0.20
0.0025
0.005
0.010
0.001
0.0031
I
4
0.0030
8.0
0.20
0.0030
0.010
0.010
0.004
0.0017
I
5
0.0040
7.5
0.20
0.0040
0.000
0.020
0.004
0.0014
I
6
0.0050
6.5
0.25
0.0030
0.010
0.020
0.004
0.0024
I
7
0.0050
6.0
0.20
0.0030
0.010
0.040
0.005
0.0000
R
8
0.0050
6.8
0.20
0.0030
0.100
0.000
0.005
0.0000
R
9
0.0050
7.0
0.20
0.0030
0.010
0.050
0.005
0.0000
R
(I = invention, R = reference)
[0096] The steels were produced by casting a slab and reheating the slab at a temperature of at most 1250° C. This temperature is the maximum temperature, because at higher reheating temperatures excessive grain growth may occur. The finishing temperature during hot rolling was 900° C., coiling temperature 650° C. followed by pickling and cold rolling (67%) and continuous annealing at a peak metal temperature of 800° C. and hot-dip-galvanising. Steel 3a also contained 16 ppm B.
[0000]
TABLE 2
Mechanical properties before and after the paint-baking cycle
As-produced
YLD
UTS
A80
After 2% + 170° C./20 min
steel
(MPa)
(MPa)
(%)
YLD
WH (MPa)
BH (MPa)
1
340
460
32
420
35
45
2
345
465
31
425
35
45
3
351
470
30
426
36
39
4
420
530
17
498
34
44
5
408
518
18
483
35
40
6
349
468
29
424
35
40
7
295
420
34
330
35
0
8
359
475
29
394
35
0
9
362
480
29
398
36
0
3a
371
480
27
457
34
52
WH = workhardening due to 2% prestrain
BH = Bake-hardening due to 20 min at 170° C.
[0097] The results presented in Table 2 clearly demonstrate that the presence of solute carbon at levels of 14 to 24 or to 31 ppm results in an increase of about 40 MPa on top of the work-hardening and the base strength of the steel. The inventors found this effect to be present at solute carbon levels between 5 and 50 ppm. | This invention relates to a high strength bake-hardenable low density steel and to a method for producing said the steel. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to incandescent electromagnetic (E-M) radiation sources and electrical switching circuits. More specifically this invention relates to selective incandescent emitters that preferentially radiate within a selected portion of the E-M spectrum, and to electrical power controllers and switching.
[0003] 2. General Background and Description of Related Art
[0004] For an emitter of thickness d that has spectral absorption coefficients a ν at frequency ν, which is much larger than its optical scattering coefficient σ ν , the spectral emissivity, ε ν , at frequency νis given by, ε ν =(1−R)(1−T)/(1−RT a ). R is the surface reflectivity and T a , being the transmissivity, is given by exp(−a ν d). Therefore, by utilizing the appropriate first order expansions, for optically thin media (i.e. a ν d<<1, yielding minimal absorption of internally generated radiation) with negligible optical scattering, we get an emissivity equal to a ν d, and for optically thick media (i.e. a ν d>>1, yielding almost total absorption of internally generated radiation) we get an emissivity equal to 1−R. The spectral emissivity of an object that absorbs perfectly (i.e. R=0) at all wavelengths is a constant value of one. The object is called a blackbody, and its spectral intensity distribution is given by the Plank blackbody distribution.
[0005] For an incandescent body radiating at a particular temperature, the power radiated as a function of wavelength is the product of the emissivity and the Plank blackbody spectral distribution. The Plank distribution varies strongly with temperature, and therefore, so does the radiated intensity. The hotter the blackbody, the shorter the median wavelength of its radiated spectrum. For example, up to about solar temperatures (5776 K), the visible-to-infrared (VIS/IR) radiant power ratio increases with temperature. Since thermal material properties limit practical incandescent lighting to temperatures less than about 3100 K (a standard 100 W tungsten bulb operates at about 2770 K), significant improvements in the VIS/IR ratio require making the emissivities within the near infrared (NIR) much smaller than those within the visible spectrum. Selective emitters are incandescent radiant bodies with emissivities that are substantially larger in a selected portion of the spectrum, thereby significantly shifting their radiated spectral distribution from that of a blackbody radiating at the same temperature.
[0006] One means of attaining selective emissivity within the VIS is to construct optically thick emitters from materials with reflectivity R larger within the NIR than within the VIS (the emissivity of an optically thick emitter is 1−R). However, the relatively small variations in R exhibited by most refractory materials within the visible and NIR regions are not enough to provide significant selectivity. The tungsten-filament emitter used in standard incandescent light bulbs is an example. Its emissivity, which is almost two times greater within the VIS than within the NIR, provides very little selectivity because even at 2770 K, the total power within the NIR of the Plank distribution is an order of magnitude greater than that within the VIS.
[0007] An optically thick emitter resulting in better selectivity than tungsten is the Nernst Glower (Ropp 1993, and Solomon 1912). Commercially produced from 1902 to 1912, it consists of a ceramic oxide composite (zirconia, thoria, ceria and yttria) filament that glows brightly when resistively heated to up to 2650 K by an electric current. Typical lamp life, which is limited by electrolysis of the oxides during operation, is about 800 hours. Thermal failure of the electrodes (i.e. the electrical leads), which are drawn from platinum, can also be a problem. Though its VIS/NIR radiant power ratio is grater than that of tungsten, the glower has a negative temperature coefficient of resistance, which, without adequate ballast, causes thermal runaway to catastrophically high temperatures. A wire-wound ballast resistor having a positive current vs. voltage curve is used. However, energy loss within the ballast decreases overall energy efficiency to about half that of tungsten bulbs, and while modem electronic ballast have been developed for fluorescent lighting, none have been developed for incandescent lighting. Moreover, since electrical conduction within the ceramic composition occurs only at high temperatures, a separate heater is required to attain “turn-on” temperatures (i.e. the minimum temperature at which the ceramic composition appreciably conducts).
[0008] Another means of attaining selective emissivity is to utilize optically thin emitters. Optically thin selective emitters are important because their spectral emissivities are a direct function of their spectral absorptivities, which can vary by orders of magnitude. One well-known approach to exploiting the spectral selectivity of certain optically thin ceramic oxides is to heat the emitters within a gas flame that does not itself radiate extensively within the NIR. Known as the Welsbach mantle, a mixture of ceramic oxides (mainly zirconia, thoria and ceria) is impregnated within thin gauze strands and arranged within a cylindrical framework. When first lit, the gauze burns away, leaving the ceramic composition in the form of thin strands. Since, for zirconia, thoria and ceria, the spectral absorptivity is well over two orders of magnitude greater within the VIS than within the NIR, and since the ceramic strands constitute optically thin emitters with spectral emissivity proportional to spectral absorptivity, the mantles radiate at significantly greater VIS/NIR radiant power ratios than tungsten bulbs. But since gas flame heating is unsuitable for general lighting purposes the lanterns are limited to mainly outdoor recreational use. The patent of Fok (1970) is another example of a special purpose (i.e. miniature lighting) optically thin, selective emitter, but in this case, a semiconductor, instead of ceramic oxides compose the emitter body. The rear-earth oxide emitters discussed by Chubb et al. (1999), present other examples of special purpose (i.e. thermophotovoltaic energy conversion) optically thin selective emitters. In this case the emitters are optimized for selective emissivity within the NIR.
[0009] A relatively recent approach to selective emissivity that combines the potentially high selectivity of optically thin emitters with the versatility of thick emitters is to utilize significant optical scattering within materials having large variations in spectral absorptivity (see Warren et al. 1976, Riseberg 1985, Chubb and Lowe 1993, or McIntosh, 2000). With this approach, an optically thick emitter can radiate as if optically thin because scattering limits the distance below the surface from which significant amounts of internally generated radiation can emerge. Unlike the case with no internal scattering, with scattering an optically thick medium can exhibit a selective emissivity that is a function of its spectral absorption coefficient, a ν . This is important because oxides such as zirconia and ceria have absorption coefficients that can be two to three orders of magnitudes greater within the VIS than within the NIR. However, a mathematical description of such emitters requires a radiation transfer model. A formulation of such a model was solved in closed form by Chubb and Lowe (1993) to obtain a general expression for the spectral emissivity. In FIG. 13, ε ν (the spectral emissivity) is plotted as a function of z ν (the scattering albedo) for an optically thick body with z ν =σ/(a ν +σ) (a ν is the spectral absorption coefficient and σ is the scattering coefficient). As z ν approaches 1, ε ν decreases by many orders of magnitude. Therefore, for high selectivity, 1−z ν should be roughly two to three orders of magnitude smaller than 1 in the desired low emissivity portion of the emission spectrum, and a ν should have values roughly two to three orders of magnitude greater within the desired high emissivity portion of the spectrum than its values within the low emissivity portion of the spectrum. Since σ does not vary significantly with wavelength, this requires a substantial decrease in a ν as ν transitions from the VIS to the NIR (assuming the VIS is the desired high emissivity portion of the spectrum). For zirconia and ceria, a ν decreases by approximately three orders of magnitude.
[0010] Only a few published reports describe attempts to enhance spectral selectivity by introducing significant optical scattering within incandescent emitters (Warren et al. 1976, Riseberg 1985, McIntosh 2000). Riseberg discloses a candoluminescent filament with a carbonized resistive core, wherein the sheath surrounding the core contains a porous structure that one supposes could provide some degree of optical scattering. However, nowhere within the disclosure is there mention of utilization of the porous structure to provide any optical scattering or enhancement of spectral selectivity. Moreover, due to the carbon-thoria and the carbon-ceria makeup of the filament, and the fact that the maximum temperature at which phase stability at the carbon interfaces exists is only about 2250 K, sufficiently high temperatures cannot be maintained to provide the desired efficiency improvements.
[0011] In Warren et al. (1976), the core of the emitter contains a metal-ceramic oxide composite that is resistively heated via an electric current and that conducts heat to the outer emitting portion, which has a plurality of spaced minute optical scattering discontinuities and optical absorption coefficients such that visible radiation is substantially absorbed while traversing the distance between scattering discontinuities. However, similarly to Riseberg (1985), phase instabilities at the metal-ceramic interface do not allow stable operation above 2200 K. Another fundamental problem for Warren (as well as for Riseberg) is the reliance on thermal conduction between a heating component (the emitter core) and an emitting component (the outer sheathe), which are chemically different, and therefore cannot maintain interface stability at sufficiently high temperatures. This problem is a result of being unable to directly heat the emitting layer via stable electrical resistive heating.
[0012] McIntosh (2000) describes a selective emitter having absorption and scattering coefficients consistent with the radiative transfer design suggested by FIG. 13 and described above. The body of the disclosed Multi-Element Selective Emitter (MESE) is structured in the form of a hollow bi-layer tube with a tungsten heating coil enclosed within. The coil does not physically contact the tube, thereby avoiding thermally activated surface-to-surface corrosion. Heating is accomplished by radiant energy transfer; however, this approach yields maximum outer layer temperatures of less than 2200 K. Consequently, the VIS/NIR radiant power ratio is no greater than that of a standard tungsten bulb operated at 2770 K.
SUMMARY OF THE INVENTION
[0013] The invention provides an incandescent selective emitter having an electrically conducting externally emitting body that is directly resistively self-heated, and that contains significant optical discontinuities such that the relative values of its optical scattering and absorption coefficients allow substantial selectivity within the relevant E-M spectrum. In the preferred embodiment, direct resistance heating of the emitter body is accomplished by connecting electrodes across and conducting a current through the emitter. This approach overcomes the need to depend on radiant heating, which proved insufficient with the MESE (McIntosh 2000), and overcomes the need to depend on thermal conduction between two dissimilar materials, which proved unstable at high temperatures with the emitters disclosed by Warren et al. (1976) and Riseberg (1985). Selective emissivity is accomplished by utilizing, for the emitter body, a refractory material with spectral absorption coefficients that are much larger within the desired high emissivity portion of the spectrum (i.e. the selected spectrum) than that within the desired low emissivity portion of the spectrum. Significant scattering is introduced by incorporating many minute pores within a multicrystalline body. Wide band-gap materials such as the ceramic oxides zirconia, ceria and thoria, are used for selectivity within the UV-VIS, and a wide band-gap semiconductor such as silicon carbide or rare earth doped ceramics such as ytterbium and thulium doped zirconia (Chubb et al.) are used for selectivity within the VIS-NIR. However, because the conductivity of such materials increases with temperature, without a means of electro-thermal stabilization, thermal runaway to catastrophically high temperatures occur.
[0014] Different methods for limiting the emitter current can be used to prevent thermal runaway. For instance, a variety of electronic, magnetic or resistive ballast, which are well known within the art, can be used. Additionally, a novel electronic ballast utilizing a triac to switch off electrical power for longer durations in response to a load with a decreasing resistance is disclosed. This provides a simplified electronic ballast design that is more efficient and cost-effective that one based on fluorescent lamp ballast designs. Also provided is an efficient resistive ballast design obtained by mounting a metal coil resistor within the cylindrical cavity of a tube-shaped emitter body without physically contacting the cavity walls. This allows recovery by the emitter of the heat dissipated by the resistor. A further stabilization approach provided involves applying additional radiant heating to the emitter body during operation. The absorbed radiant power raises the emitter temperature to significantly greater values than would otherwise be possible at that particular emitter current and voltage. Since the radiated power, which is proportional to (temperature){circumflex over ( )}4 is now substantially greater (or, from the other perspective, the resistively generated power, which is proportional to (voltage){circumflex over ( )}2, is now substantially less), thermal power fluctuations are quickly radiated away and do not result in heat buildup and thermal runaway. While an externally positioned electrical coil heater is conceivable for this task, a heater mounted concentrically within a tubular emitter is more efficient.
[0015] In oxygen rich atmospheres, ceramic oxides such as zirconia and thoria are solid-state electrolytes that conduct electricity primarily via oxygen ion charge carriers. This can yield oxygen evolution at, and oxidation of the electrodes. But at high temperatures and very low oxygen partial pressures, the oxygen ion component is essentially eliminated and conduction is via electron hopping between stationary oxygen sites within the crystalline lattice. The invention facilitates electronic condition by providing an evacuated or an inert gas enclosure (i.e. a glass bulb) for the emitter, allowing the use of inexpensive metal electrodes such as molybdenum and tungsten (platinum electrodes are used with the Nernst Glower). An oxygen getter is provided to maintain negligibly low oxygen levels.
[0016] To minimize electrode-emitter interface instabilities, the electrodes are spatially isolated from the emitter by electrically conducting spatial isolation terminals positioned between the electrodes and the electrical contact points on the emitter body. The isolation terminals are formed from materials exhibiting stable interfaces with both the emitter material and the electrode material at temperatures somewhat below that of the emitter center. This includes terminals formed from the emitter material, in which case the major function is providing thermal insulation between emitter and electrode, or terminals formed from an inert metal, in which case the major function is electrochemical buffering.
[0017] At room temperature, ceramic oxides such as zirconia and thoria have high electrical resistances and must be preheated to minimum “turn-on” temperatures, at which point electrical conduction ensues. For the embodiments involving an internally mounted electrical coil, this arrangement allows using the coils as pre-heaters. The other embodiments are heated with externally mounted heating coils. The need for preheating requires a resistance change sensing device that signals a switching device to modify the heater current (typically to shut it off) once electrical conduction within the emitter body ensues. Such devices, which are well known within the art, include solid-state relays, electromagnetic relays, bimetallic switches, and electronic switching circuits. A novel electronic switching circuit utilizing triacs to decrease the on-time of electrical power in response to an electrical component having a decreasing resistance is disclosed. Prior art triac switching circuits of comparable simplicity can only increase instead of decrease the on-time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is a perspective view of physical layout- 1 of the invention.
[0019] [0019]FIG. 2 is a perspective view of physical layout- 2 of the invention.
[0020] [0020]FIG. 3 is a perspective view of physical layout- 3 of the invention.
[0021] [0021]FIG. 4 is a functional diagram showing functional relationships applicable to layout- 1 or layout- 2 .
[0022] [0022]FIG. 5 is a functional diagram showing an additional functional relationship applicable to layout- 1 .
[0023] [0023]FIG. 6 is a functional diagram showing a functional relationship applicable to layout- 3 .
[0024] [0024]FIG. 7 is a functional diagram showing an additional functional relationship applicable to layout- 3 .
[0025] [0025]FIG. 8 is a schematic circuit diagram applicable to the FIG. 4 functional diagram.
[0026] [0026]FIG. 9 is a schematic circuit diagram applicable to the FIG. 5 functional diagram.
[0027] [0027]FIG. 10 is a schematic circuit diagram applicable to the FIG. 6 functional diagram.
[0028] [0028]FIG. 11 is a schematic circuit diagram applicable to the FIG. 7 functional diagram.
[0029] [0029]FIG. 12 is a functional diagram that highlights the resistance inversion function of the stabilization circuits.
[0030] [0030]FIG. 13 is a plot of emissivity as a function of z ν for optically thick scattering media.
DETAILED DESCRIPTION OF THE INVENTION
[0031] [0031]FIG. 1 shows a perspective view of physical layout- 1 of the invention, which is a first physical layout of the thermal components of the invention. An internal tungsten heating coil 102 is positioned within a tubular emitter body 104 such that there is no physical contact between the two by threading coil leads 110 and 110 ′ concentrically through fixed end-caps 108 and 108 ′. To ensure no sagging, the coil is mounted in a stretched position and fixed in place by utilizing molybdenum crimps 120 applied between a bend in the leads 121 and the end-caps. The end caps help contain radiation within the emitter cavity 106 . To prevent electrical conduction between the emitter body and the coil leads, the end-caps are made from a high electrical resistivity refractory oxide such as magnesia or alumina using standard powder pressing techniques. Electrodes 112 and 112 ′, attached roughly 5 mm from the end of the emitter body, provide electrical current to the middle two thirds of the emitter body without significantly heating the ends. Annular isolation terminals 114 and 114 ′, formed from the emitter material by extrusion into rings of width greater than the emitter body thickness, are positioned between annular electrode contacts 116 and 116 ′ and the emitter body to provide thermal insulation between emitter and electrode (the electrode contacts distribute the current from the electrodes to the emitter body).
[0032] For all the drawing figures, the emitter body is extruded from a paste obtained by mixing a sucrose solution with a micron grain size powder mixture comprised of 32% by volume yttria stabilized zirconia doped with about 1 volume percent ceria and mixed with 33% by volume each of carbon-black and graphite powder and subsequently sintered at about 1300 C to form a tubular body roughly 30 mm long, 4 mm in diameter, and 0.5 mm thick. The carbon black and graphite powder vaporize during sintering leaving a porous microstructure, and as with the outer layer of the emitter described by McIntosh (2000), yields 1 −z ν values of roughly 0.60 within the VIS and 0.0013 within the IR.
[0033] [0033]FIG. 2 shows a perspective view of physical layout- 2 of the invention, which is a second physical layout of the thermal components of the invention. In this layout, an external tungsten heating coil 224 is positioned externally outside the tubular emitter body 204 such that there is no physical contact between the two. Electrodes 212 and 212 ′ connected to annular electrode contacts 216 supply electrical current to the emitter body. Annular isolation terminals 214 , formed from the emitter material by extrusion, are positioned between annular electrode contacts 216 and the emitter body to provide thermal insulation between emitter and electrode. Bi-layer spacing rings 226 and 226 ′ positioned between the heating coil's end hoops 222 and 222 ′, and the electrode contacts 216 maintain concentricity and spacing of the heating coil. The outer layer 227 and 227 ′ of the spacing rings are thin molybdenum rings whose electrical contact with the end hoops 222 ensure high electrical conductivity in these areas, thereby generating minimal resistive heating in these regions. The inner layers 225 and 225 ′ of the spacing rings are extruded from alumina or magnesia or other high electrically resistive refractory oxide. End-caps 208 are used to help contain radiation within the emitter cavity (not shown). The external heating coil is connected to electrical power via leads 228 and 228 ′.
[0034] [0034]FIG. 3 shows a perspective view of layout- 3 of the invention, which is essentially layout- 1 with the externally mounted heating coil of layout- 2 . Internal tungsten heating coil 302 is positioned within a tubular emitter body 304 such that there is no physical contact between the two by threading coil leads 310 and 310 ′ concentrically through fixed end-caps 308 , which are identical to 108 . The internal coil is mounted in a stretched position and fixed in place by tubular molybdenum crimps 320 positioned between the end caps and a bend 321 in the coil leads. Electrodes 312 and 312 ′ attach to ring-shaped electrode contacts 316 roughly 5 mm from the end of the emitter body. Annular isolation terminals 314 are positioned between the electrode contacts 316 and the emitter body. Bi-layer spacing rings 326 positioned between the end hoops 322 and 322 ′ of external heating coil 324 and the electrode contacts 316 maintain concentricity and spacing of the heating coil. As described for spacing rings 226 , the outer layer 327 of the spacing rings are thin molybdenum rings whose electrical contact with the end hoops 322 ensure high electrical conductivity in these areas. The inner layer 325 of the spacing rings is extruded from alumina or magnesia or other high electrically resistive refractory oxide. The external heating coil is connected to electrical power via leads 328 and 328 ′.
[0035] [0035]FIG. 4 is a functional diagram showing a first and a second functional layout of the thermal and electrical components applicable to physical layout- 1 and physical layout- 2 respectively. For functional layout- 1 , electrical power for the emitter body 404 and the heating coil (in this case heating coil 402 is mounted internally and corresponds to internal coil 102 ) is derived from voltage source 452 . One end of the emitter body is electrically connected to resistance sensing device 440 , which senses the emitter body's increase in electrical conductivity when heated to its turn-on temperature by heating coil 402 , and signals switching module 442 (which is connected to heating coil 402 ), via interconnection 444 . In response, the switching module switches terminal 411 from a high power to a low power. Ballast 450 , through which electrical power to the emitter body is routed, via electrode 412 , ensures stable emitter operation. Functional layout- 2 is exactly the same as for functional layout- 1 except that coil 402 now corresponds to outer coil 224 , and the low power switched to by switching device 442 corresponds to zero power.
[0036] [0036]FIG. 5 is another functional diagram showing a third functional layout of the thermal and electrical components applicable to physical layout- 1 . Prior to the emitter body 504 attaining its turn-on temperature, terminals 541 and 539 are electrically connected via switching module 542 such that internal heating coil 502 is connected directly across the input power source 552 . Electrode 512 connects emitter body 504 to resistance sensing device 540 , which senses the emitter body's increase in electrical conductivity when heated to its turn-on temperature by internal heating coil 502 , and signals switching module 542 via interconnection 544 , at which point the switching device severs electrical contact between terminals 539 and 541 and connects terminal 539 to terminal 543 instead. This provides a series connection between the emitter body and the heating coil, and allows use of the internal heating coil as both an emitter body pre-heater and as ballast.
[0037] [0037]FIG. 6 is a functional diagram showing a fourth functional layout of the thermal and electrical components applicable to physical layout- 3 . Electrical power for the emitter body 604 , external heating coil 624 , and internal heating coil 602 is derived from voltage source 652 . One end of the emitter body is electrically connected to resistance sensing device 640 , which senses the emitter body's increase in electrical conductivity when heated to its turn-on temperature by the heating coils, and signals switching module 642 , which is connected to internal heating coil 602 , and switching module 643 , which is connected to external heating coil 624 . In response, switching module 642 switches terminal 611 from a high power to a low power, and switching module 643 disconnects terminal 629 from electrical power. As described above, this configuration does not require separate ballast because of the increase of emitter body temperature attributable to inner heating coil 602 .
[0038] [0038]FIG. 7 is another functional diagram showing a fifth functional layout of the thermal and electrical components applicable to physical layout- 3 . Prior to the emitter body 704 attaining its turn-on temperature, terminals 741 and 739 are electrically connected via switching module 742 such that external heating coil 724 is connected directly across the input power supply 752 . Electrode 712 connects emitter body 704 to internal heating coil 702 in series with input power supply 752 . The change in voltage at terminal 743 due to the emitter body's increase in electrical conductivity when heated to its turn-on temperature by external heating coil 724 , is communicated to switching device 742 via interconnection 744 , at which point the switching module disconnects terminal 739 from electrical power. The internal heating coil functions as ballast in its series connection with the emitter body.
[0039] [0039]FIG. 8 is a schematic circuit diagram showing a first and a second electrical schematic applicable to functional layout- 1 and functional layout- 2 respectively of FIG. 4. For functional layout- 1 resistor 824 represents internal heating coil 102 , and for functional layout- 2 resistor 824 represents external heating coil 224 . Before emitter body 804 is heated to its turn-on temperature by heating coil 824 , capacitor 874 charges quickly enough through resistor 866 to cause diac 862 to fire relatively early in the phase of the AC supply voltage 852 as the phase increases from zero degrees or from 180 degrees. This causes the length of time that triac 843 conducts electricity to be relatively long, which causes heating coil 824 to dissipate a relatively large electrical power.
[0040] After emitter body 804 attains its turn-on temperature, its conductivity increase causes a decrease in the voltage between nodes 884 and 886 via resistor 870 (which functions as a resistance sensing device) during the period of time when triac 842 is switched off. This causes slower charging of capacitor 874 , and for functional layout- 1 where resistor 824 is the internal heating coil, resistor 866 is chosen such that diac 862 fires relatively late in the phase of the supply voltage so as to decrease the power dissipated by heating coil 824 by a predetermined amount. For functional layout- 2 where resistor 824 is the external heating coil, resistor 866 is chosen such that capacitor 874 charges so slowly that diac 862 never fires, effectively turning off heating coil 824 . For both layout- 1 and layout- 2 , the circuit arrangement yielding an effective decrease in electrical power caused by the increase in emitter conductivity constitutes a resistance inverting switching device that decreases the length of time current flows through the load (i.e. heating coil 824 ) in response to the resistance decrease of a variable resistance electrical component (i.e. the emitter body 804 ). In this case the load is distinct from the variable resistance electrical component.
[0041] After emitter body 804 attains its turn-on temperature, but before self-heating to its predetermined operating temperature, capacitor 872 charges quickly enough through resistor 864 to cause diac 860 to fire relatively early in the phase of the AC supply voltage as the phase increases from zero degrees or from 180 degrees. This causes the length of time that triac 842 conducts electricity to be relatively long, which causes the emitter body to dissipate a relatively large electrical power. If the emitter body 804 self-heats past its predetermined operating temperature, its conductivity increase causes a larger decrease in the voltage between nodes 884 and 880 via resistor 868 (which functions as another resistance sensing component) during the period of time when triac 842 is switched off. This larger voltage decrease causes slower charging of capacitor 872 such that diac 860 fires relatively late in the phase of the supply voltage so as to decrease the electrical power dissipated by the emitter body and return it to its predetermined operating temperature, thereby providing ballast. In this case the load is the same as the variable resistance electrical component, and the resistance inverting switching circuit is employed as ballast.
[0042] [0042]FIG. 9 is a schematic circuit diagram showing a third electrical schematic applicable to functional layout- 3 of FIG. 5. Resistor 902 represents internal heating coil 102 . Before emitter body 904 is heated to its turn-on temperature by heating coil 902 , capacitor 974 charges quickly enough through resistors 970 and 968 (triac 942 is off) to cause diac 962 to fire relatively early in the phase of the AC supply voltage 952 . This causes the length of time that triac 943 conducts electricity to be relatively long, which causes heating coil 902 to dissipate a relatively large electrical power. Meanwhile, capacitor 972 is chosen large enough such that it charges too slowly to allow diac 960 to fire, thereby maintaining triac 942 in its off state. After emitter body 904 is heated to its turn-on temperature, its conductivity increase causes a decrease in the voltage between nodes 984 and 980 . This causes capacitor 974 to charge so slowly that diac 962 never fires, effectively severing the heating coil's direct connection, via triac 943 , across the supply voltage. However, because the voltage at node 980 is now much closer to that at node 984 , capacitor 972 can now charge fast enough to cause diac 960 to fire early enough in the phase of the supply voltage to turn on triac 942 for a substantial length of time. This essentially connects the emitter body in series with the heating coil across the supply voltage. In this case, in addition to utilizing a resistance inverting switching arrangement to disconnect the heating coil 902 from direct connection (via triac 943 ) across the power supply 952 , a non-inverting switching arrangement is employed to connect it in series with the emitter body.
[0043] [0043]FIG. 10 is a schematic circuit diagram showing a fourth electrical schematic applicable to functional layout- 4 of FIG. 6. Resistor 1002 represents internal heating coil 102 , and resistor 1024 represents external heating coil 224 . Before emitter body 1004 is heated to its turn-on temperature by heating coils 1024 and 1002 , capacitors 1074 and 1072 charge quickly enough through resistors 1066 and 1064 respectively to cause diac 1062 and 1060 respectively to fire relatively early in the phase of the AC supply voltage 1052 . This causes the length of time that triacs 1043 and 1042 conduct electricity to be relatively long, which causes heating coils 1024 and 1002 to dissipate relatively large amounts of electrical power. After emitter body 1004 attains its turn-on temperature, its conductivity increase causes a decrease in the voltage between nodes 1084 and 1086 via resistance sensing resistor 1070 , and between nodes 1084 and 1080 via resistance sensing resistor 1068 during the period of time when diac 1040 is not conducting. This causes slower charging of capacitors 1074 and 1072 , such that diac 1062 never fires, effectively turning off heating coil 1024 , and such that diac 1060 fires substantially later, effectively decreasing electrical power to heating coil 1002 . In this case two different switching modules are used to decrease and disconnect the power from the internal and external heating coils respectively.
[0044] [0044]FIG. 11 is a schematic circuit diagram showing a fifth electrical schematic applicable to functional layout- 5 of FIG. 7. Resistor 1102 represents internal heating coil 102 , and resistor 1124 represents external heating coil 224 . Before emitter body 1104 is heated to its turn-on temperature by heating coils 1124 , capacitor 1172 charges quickly enough through resistor 1168 and heating coil 1102 to cause diac 1160 to fire relatively early in the phase of the AC supply voltage 1152 . This causes the length of time that triac 1142 conducts electricity to be relatively long, which causes heating coil 1124 to dissipate a relatively large amount of electrical power. After emitter body 1104 attains its turn-on temperature, its conductivity increase causes a decrease in the voltage between nodes 1184 and 1180 . This causes slower charging of capacitor 1172 such that diac 1160 never fires, effectively turning off heating coil 1124 .
[0045] Nominal values of the various circuit elements are:
Triacs (All): Trigger and latching currents ˜15 mA Trigger and on-state voltage ˜1 V Diacs (All): Breakover voltage ˜35 V Breakover current ˜.1 mA Capacitors (All except 972 and 1072): - .1 μF Capacitor (972): - .15 μF Capacitor (1072): - .075 μF Resistor (868): ˜10 kΩ Resistor (968 and 1168): ˜50 kΩ Resistors (864, 866, 970, 1062, 1064): ˜100 kΩ Resistors (870, 1068, and 1070): ˜200 kΩ Resistor (Internal heating coil): ˜50 Ω Resistor (External heating coil): ˜150 Ω Resistor (Emitter body): ˜50 Ω
[0046] [0046]FIG. 12 is a functional diagram that illuminates the relationships described above between the variable resistance element (i.e. the emitter body) 1204 , the resistance inverting switching device 1250 , comprising at least one resistance sensing device and at least one switching module, and the output loads 1202 and 1203 . Increased conduction in the variable resistance element 1204 causes the switching device 1250 to decrease the length of time that load current flows between nodes 1280 and 1290 , thereby effectively decreasing the time-averaged current (the opposite action occurs for increased conduction in the variable resistance element) and providing ballast to the variable resistance element as described in FIG. 8. Increased conduction in the variable resistance element 1204 also causes the switching device to decrease the length of time that load current flows between nodes 1281 and 1291 , or between nodes 1283 and 1293 , thereby providing the power control functions described in FIGS. 8, 10 and 11 . Further switching is also provided to connect or disconnect nodes 1280 b , 1281 b , and 1283 to any one of nodes 1290 , 1291 and 1293 b , thereby providing changes in circuit topology similarly to that described in FIG. 9.
[0047] The invention is not limited to the particular physical layouts shown in FIGS. 1 to 3 . Any layout that allows radiant heating and direct electrical resistive heating of the emitting volume is contemplated by the invention. For instance, the emitter body could be fabricated as a bi-layer tube, either to obtain a particularly absorbing inner layer as with the MESE (McIntosh 2000) or to obtain a thinner emitting outer layer with a low emissivity inner layer, thereby incorporating the advantages of optically thin emitters. Also, the emitter cavity could be pressurized with an inert gas such as argon to extend the life of the internal heating coil. A further example is to incorporate several support rods for the external heating coil that are attached at either end to the inner layer 225 of the bi-layer spacing rings so as to ensure stability of the heating coil. Moreover, the mounting of the emitter need not be constrained to be within a bulb enclosure. As with the Nernst Glower, the utilization of platinum or other stable electrode allows operation within air.
[0048] The functional interrelations of the electrical components of the invention are not limited to those shown in FIGS. 4 to 7 , instead all configurations are contemplated by the invention that allow various heating coils to radiantly heat the emitter body, and that allow the emitter to operate stably at elevated temperatures. For instance, a constant current source can be used instead of the ballast in FIG. 4, or a separate tungsten incandescent filament with associated switching module could be used to provide near-instant-on lighting until the emitter body heats up, or the external coil in FIG. 5 could be eliminated. The resistance sensing device 440 and the switching module 442 could likewise be eliminated. Also, direct electrical connections to the emitter body could be eliminated by inductively coupling microwave energy to the emitter body similarly to the induction approach used in electrode-less high intensity discharge lighting.
[0049] The electronic implementation of the functional diagrams shown in FIGS. 4 to 7 are not limited to the switching circuits shown in FIGS. 8 to 11 . For instance, instead of the electronic switching described, electromagnetic relays or bimetallic switches could be used. Other types of ballast such as the resonant designs used with fluorescent lamps can also be utilized. Any electrical arrangement capable of supplying the emitter with a stable current and modifying the current conducted by the heating coils is contemplated by the invention. For instance, a timed switching of the electrical power supplied to the heating coils instead of one triggered by changes in the emitter body's conductivity is an additional possibility.
[0050] The electronic implementations of the resistance inverting switching circuits are not limited to those shown in FIGS. 8 to 11 . Instead, any implementation such that the function described for FIG. 12 is retained is contemplated by the invention. For instance, the further switching that is provided to connect or disconnect nodes 1280 b , 1281 b , and 1283 to any one of nodes 1290 , 1291 and 1293 b could be via electromagnetic relay instead of electronic switching. Moreover, the switching circuits are not limited to the number of input and output devices shown in FIG. 12. More variable resistance elements can be added and the number of loads can be changed.
[0051] It can thus be appreciated that the objectives of the present invention have been fully and effectively accomplished. The foregoing specific embodiments have been provided to illustrate the structural and functional principles of the present invention and is not intended to be limiting. To the contrary, the present invention is intended to encompass all modifications, alterations, and substitutions within the spirit and scope of the appended claims.
REFERENCES
[0052] Chubb, D. L. and Lowe, R. A., J. Appl. Phys. 74, (9), 5687 (1993).
[0053] Chubb, D. L., Pal, A. T., Patton, M. O., and Jenkins, P. P., J. European Ceramic Soc. 19, 2551, (1999).
[0054] Fok, M. V., Incndescent Lamp With a Glower Made of an Alloyed Semiconductor Material, U.S. Pat. No. 3,502,930, (Mar. 24, 1970).
[0055] McIntosh, D. R., Multielement Selective Emitter, U.S. Pat. No. 6,018,216, (Jan. 25, 2000).
[0056] Riseberg, L. A., Candolumiscent Electric Light Source, U.S. Pat. No. 4,539,505, (Sep. 3, 1985).
[0057] Ropp, R. C., The Chemistry of Artifical Lighting Devices (Elsevier, N.Y., 1993).
[0058] Solomon, M., Electric Lamps, P. 138-175 (D. van Nostrand, N.Y., 1912).
[0059] Warren, R. W., Feldman, D. W., Incandescent Source of Visible Radiation, U.S. Pat. No. 3,973,155, (Aug. 3, 1976). | The invention provides an incandescent electromagnetic radiation source comprising a non-metallic emitter body that conducts electricity, and an emitting volume within the emitter body that has a thermal energy, optical absorption coefficients, and optical scattering coefficients, and that generates and externally emits electromagnetic radiation. An electric current is applied to the emitting volume such that a substantial portion of the thermal energy is generated by electrical resistive heating within the emitting volume. The optical absorption coefficients have significantly larger values within a predetermined high emissivity portion of the electromagnetic spectrum than within a predetermined low emissivity portion of the spectrum, and the optical scattering coefficients have much larger values than the optical absorption coefficients within the predetermined low emissivity portion of the spectrum. Also, to provide electrical stability and electrical switching, a resistance inverting switching device is used. The device comprises a variable resistance element, at least one output load, at least one resistance sensing device whereby changes in the resistance of the variable resistance element is sensed, and at least one electronic switching element that switches the load current on and off. Electrical interconnections between the switching element and the resistance sensing device causes the switching element to decrease the length of time that the load conducts current when the electrical resistance of the variable resistance element decreases, and to increase the length of time that the load conducts current when the electrical resistance of the variable resistance element increases. | 7 |
This application is a continuation of International Application No. PCT/AT2005/000306, filed Aug 2, 2005.
The present invention concerns a damper, especially for movable furniture parts, with a damper with a ram which can be subjected to pressure and which is supportable on a support element.
There are an enormous variety of dampers known in the state of the art, for example for use in movable furniture parts. These can be designed both as linear and as rotation dampers. They normally have a path-dependent damping function. This means that the degree of damping depends on how far the ram is pushed in or pulled out. In the state of the art, the ram comes into contact with a support element at the start of the damping movement, if it is not originally already permanently connected to this. The course of the damping movement is then fixed by the characteristics of the damper per se and the geometrical arrangement of damper and support element.
The object of the invention is to be able further to influence the damping function of the damper arrangement of the generic type.
This is achieved according to the invention by the fact that the support element is displaceable or slidable in its position relative to the ram.
The start, the course and the end of the damping process can additionally be influenced by the displaceable or slidable support element. When dampers with a path-dependent damping function are used, this then automatically results in an effect on the instantaneous damping value as a function of the position relative to each other of those movable furniture parts on which the damper arrangement is affixed.
It is usually desirable in that case if the ram meets the support surface on the support element assigned to it before it reaches the furniture part, fitting element, articulated lever or suchlike. This causes the damper to take effect at an earlier stage. Moreover, the ram can also be pressed into the damper more quickly than would be possible without the support element. Normally, the support area of the support element will thus be arranged between the ram and the fitting elements, articulated levers, furniture parts or suchlike arranged behind it—at least during the active damping process. It is, however, also possible by a corresponding recessed arrangement of the support element to achieve a later activation of the damper, to reduce the stroke or suchlike.
In principle, there are two possible variants in this case. The first of these makes provision that the support element is movable between a first and at least one second end position by means of a movement of the damper arrangement. In this embodiment, the support element moves automatically each time in the same way while the damper arrangement is in operation, so that the damping function of the damper used is always influenced in the same way. This variant is especially advantageous when the damping function of a fabricated damper is to be modified for a special application.
In a second group of variant embodiments of the invention, however, provision may also be made that the damper arrangement provides an adjustment device, preferably an adjustment screw, which enables the support element to be fixed in various positions relative to the ram. The support element can be fixed in various positions by the adjustment device, as the result of which a preferably manual adaptation is possible. This can be used, for example, in hinges with a damper arrangement according to the invention, to reverse a change in the damping path of the damper caused by a joint adjustment screw and/or a depth adjustment screw, in order thereby to ensure a constant damping function.
DESCRIPTION OF THE DRAWINGS
Further features of the invention are explained with the aid of the following description of some embodiments. The figures show:
FIGS. 1 to 3 : a first embodiment according to the invention,
FIGS. 4 and 5 : a second embodiment according to the invention,
FIGS. 6 to 8 : a third embodiment according to the invention and
FIGS. 9 to 12 : a fourth embodiment according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The embodiment according to FIGS. 1 to 3 shows an inventive damper arrangement which is integrated into a furniture hinge with hinge arm 5 and hinge cup 6 as fitting elements. The damper 1 in this embodiment is arranged on the hinge cup 6 . It has a ram 2 which travels in and out, preferably with a path-dependent damping function. The hinge arm 5 of the hinge 1 shown can, as known in the state of the art, be clipped onto a base plate 11 via a hook-on device 12 and a snap closure 13 . A joint adjustment screw 15 and a depth adjustment device 10 are provided as known in the art to adjust the relative position between hinge cup and hinge arm. Hinge arm 5 and hinge cup 6 are linked by articulated levers 8 and 8 ′ which are arranged on articulated axles 7 . According to the present invention, a movable support element 3 is now provided. In this embodiment, the support element 3 is rotatably mounted on the hinge arm 5 , thus on one of the two fitting elements of the hinge. In addition, a coupling lever 9 is provided which is also rotatably mounted on the hinge arm 5 . In this embodiment the coupling lever 9 is integrated into the outer articulated lever 8 ′. However, it may also be designed as a separate lever in addition to the articulated lever or levers 8 , 8 ′.
FIG. 2 shows a section along the straight line AA from FIG. 3 through the inventive arrangement, where hinge cup 6 and hinge arm 5 can be seen in the folded-out position. When moving into the position shown in FIG. 1 , the coupling lever 9 is pivoted relative to the arm 5 . As a result, the coupling lever 9 moves the support element 3 from the position shown in FIG. 2 to that shown in FIG. 1 . During the closing movement, the ram 2 comes into contact with the support element 3 . By raising the support element 3 , this contact occurs earlier than if the ram 2 , as known in the state of the art, were to rest directly on the hinge arm 5 . So the ram 2 is pushed sooner and then deeper into the cylinder of the damper 1 , as the result of which, especially in dampers with path-dependent damping function, the damping value assigned to a certain angle of incidence between the fitting elements increases in each case. The coupling lever 9 in this embodiment is essentially z-shaped, but can take any other form, depending on the geometry of the damper arrangement. While in the first embodiment the coupling lever 9 is arranged such that it converts a movement of the articulated lever 8 ′ into a movement of the support element 3 , the second embodiment according to FIGS. 4 and 5 has an inventive arrangement in which the support element 3 itself is integrated into the articulated lever 8 ′. The support element 3 can—in an embodiment not shown here—also alternatively be pivotably mounted on the hinge arm 5 and acted upon by the hinge cup 6 , without being integrated into an articulated lever 8 , 8 ′. The form of the support element 3 and, if applicable, of the coupling lever 9 specifies in the embodiments from when, and how far, the ram 2 is pressed into the damper 1 at the respective pivoting angles between hinge cup 6 and hinge arm 5 , as the result of which, in turn, the angle-dependent damping function is influenced.
In the third. embodiment according to FIGS. 6 to 8 , the housing 20 of the damper 1 is anchored on the hinge atm 5 . The support element 3 forms a cover with a cross-section in the form of a hollow profile over at least one articulated lever 8 . It is pivotably arranged on one of the articulated levers 8 with the axle 16 . In this embodiment, the second fitting element 6 is not designed as a hinge cup but, as is usual for example for glass doors, as a fitting element with planar joint faces FIG. 6 shows this embodiment in the so-called closed position, in which the door 22 is closed. FIG. 7 shows an intermediate position, in which the damper is just coming into contact with the supporting area 19 of the support element 3 and is thereby activated, FIG. 8 shows the open position in which the door is open. The pivotably arranged support element 3 in this embodiment has a control contour 17 , which serves to support the support element 3 . In the variant shown here, the control contour 17 rests on a guide contour 18 formed on the fitting element 6 . Both contours 17 and 18 are at least partially convex in form. The forms of the convexities 23 and 24 are selected such that the ram 2 comes into contact with the supporting area 19 due to the pivoting of the support element 3 at the desired closing angle between door 22 and side wall 25 . Via a corresponding design of the contours 17 and 18 , there is also a guarantee that the damping characteristics of the damper 1 can be optimally exploited and the maximum possible damping stroke can be realised It is immediately obvious to the person skilled in the art that the form of the contours 17 and 18 can be adapted to the respective damper and the respective hinge, in order to achieve the optimum of the desired damping characteristics. The support element 3 has, as in the other embodiments, the advantage that to achieve the optimum damping characteristics, it is not the form of the fitting elements or articulated lever which must be modified, but the support element 3 itself can be freely designed according to the desired specifications. When opening and closing, both the contours 17 and 18 and also the ram 2 and the support element 3 slide along each other. It would, however, also be possible to provide fixed rotational connections instead of a loose fit. Obviously it would also be possible, instead of two contours 17 and 18 , also to provide only one correspondingly designed control contour 17 . This could then rest on the fitting element, articulated lever or furniture part of ordinary design. Apart from this, there is also the possibility of providing a smooth, non-convex control contour 17 via a correspondingly convex or bulging design of the guide contour 18 , since ultimately the decisive factor is the movement resulting from the interaction of the support element 3 , which can be designed in the form of an additional structural component, and the supporting area 19 respectively.
In order to prevent the support element executing unnecessary movements or rattling, provision may be made to spring-load the support element, e.g. by a bow spring, not shown in detail here, which is connected with the support element 3 and preferably always forces this in the direction of the fitting element 6 .
As is also the case in the other embodiments, it is also possible in the embodiment according to FIGS. 6 to 8 to fix the damper to the respective other fitting element. In a variation of FIGS. 6 to 8 , in this variant the housing 20 of the damper 1 would then be arranged on the second fitting element 6 , also executable as a hinge cup. The control contour 17 would then rest on the side of the hinge arm on a guide contour 18 which may be provided there.
FIGS. 9 to 12 show an embodiment in which the position of the support element 3 is manually adjustable by means of an adjustment device 4 . The support element 3 thereby remains fixed in the position once set during the relative movement between the fitting elements (hinge arm and hinge cup). The support element 3 is rotatably attached to an axle 16 and can be pivoted relative to the hinge arm 5 . The adjustment device 4 can for example be designed as a simple adjustment screw. In the embodiment shown, however, the adjustment device 4 is realised in one structural unit with the joint adjustment device 15 . To this end, the screw 4 has two areas 4 ′ and 4 ″ with different thread pitches. With the adjustment device 4 and the support element 3 , it is possible to equalise a relative position between the two fitting elements 5 and 6 which has been modified by the depth adjustment device 10 and/or the joint adjustment device 15 in such a way that the same damping function of the damper exists as before the adjustment by the depth adjustment device or the joint adjustment device. Thus it is possible to adjust the damping function at least within certain limits, independently of the relative position of hinge cup 6 to hinge arm 5 . One example of this is shown in FIGS. 11 and 12 . By corresponding adjustments of the joint adjustment screw 4 , the upper edge of the hinge arm 5 is at an angle of 9° relative to the base plate 11 in FIG. 11 . An angle of 3° is set between said upper edge of the hinge arm 5 and the support element 3 . If the angle between base plate 11 and upper edge of the hinge arm 5 is now reduced to 5° (see FIG. 12 ), then the combined adjustment device 4 automatically lowers the support element 3 to an angle of 1° relative to the upper edge of the hinge. The result of this is that in both cases the ram 2 , the fitting elements being at the same angle with respect to each other, comes into contact with the support element 3 and then is immediately forced deep into the cylinder of the damper 1 . The same damping function is thus exercised in both positions.
As the individual embodiments show, by using a correspondingly designed support element, an optimum damping path can be achieved for dampers known in the state of the art. This is especially advantageous in arrangements or hinge types in which the articulated levers are only moved very slightly in the last 20° of the closing movement, as the result of which a sufficient damping path cannot be achieved without the inventive support element.
Even when inventive damper arrangements are shown in the embodiments integrated in hinges, it is still possible to design damper arrangements according to the invention detached from hinges. In the case of hinges, the damper 1 and also the support element 3 can each be arranged on both fitting elements 5 and 6 . Naturally, the inventive damper arrangement can also be combined with any other hinge, thus not only with hinges with hinge arm and hinge cup. | A damping arrangement, in particular for displaceable furniture parts, includes a damper ( 1 ) which is provided with a tappet ( 2 ) which can be impinged upon, and which can be supported by a support element ( 3 ). The support element ( 3 ) can be positioned and/or displaced in relation to the tappet ( 2 ). | 4 |
FIELD OF THE INVENTION
The present invention relates to devices for marking radiography specimens, and in particular to devices that indicate the orientation of the specimen in a patient's body prior to removal. The present invention further relates to radiographic markers that will remain secured to specimens during manipulations accompanying radiography and pathology.
BACKGROUND INFORMATION
Radiologists frequently use markers that absorb xrays and cast an image when placed within an xray field to convey pertinent information on xray film. For example, right and left markers are routinely used to designate the anatomical orientation of the patient or to identify a particular extremity being examined. These types of markers are often placed on the surface of the examination table or xray film cassettes, within the exposure field but outside the image of the patient, to define the patient's physical orientation in relationship to the xray beam or the film.
Markers consisting of a radiopaque body and adhesive can be attached directly to the skin of patients. These markers give the radiologist a specific target for the xray and, since the radiopaque body will appear on radiographs later taken, help pinpoint the location of the area in question when reading the developed film. Some markers have been developed that can be inserted into the body to mark tissues or organs that require repeated xray monitoring. These types of markers are manufactured as staples or hooks (to attach to tissues), and even partial rings (to encircle grafted veins).
All of the previously described devices, while useful for specific purposes, have not been ideal for marking specimens removed from patients, as the described devices fail to address circumstances particular to specimen removal, radiography, and pathology. Successful removal of tumors from a patient's body requires an accurate evaluation of the excised tissue boundaries. To ensure that the entire tumor is removed, an adequate amount of healthy tissue surrounding the tumor is also extracted. The success of the surgery and the patient outcome is directly related to resection of the entirety of the tumor with an adequate healthy tissue boundary. For example, successful removal of breast tumors requires an accurate evaluation of the removed tissue boundaries to see if the tumor has effected the surrounding healthy tissue.
In the case of biopsies, a specimen is marked by the surgeon during removal from the patient. This mark aids the radiographers and pathologists in identifying the orientation of the specimen as it was present in the patient's body. Permanent marking of the exact orientation of the specimen is critical because of the manipulations—specimens must be pressed flat to properly xray—that take place during radiography. Presently, a surgeon may mark a tissue specimen by attaching sutures of various lengths, colors, or number combinations. The lengths, colors, or number of sutures convey to the pathologist the orientation of the gross pathology specimen in the patient's body. Unfortunately, this process of suturing and knotting may not be regularly performed because it is time consuming and requires detailed oral and/or written communications between surgeons, radiologists, and pathologists which can result in frustrations between the three professionals. Additional confusion may arise due to the fact that there is no standard marking method in the medical profession, since each surgeon develops his or her own method of marking.
Some radiopaque markers have been developed to address this problem, but still have some shortcomings. For example, existing markers can be attached to specimens by securing the markers with a clamping pair of pinchers, but these markers may release while the specimen is being radiographed and otherwise examined, and thus, the benefit is lost. Also, because such existing markers have sliding components and locking points, they tend to be thicker and larger than ideal. Since specimens must lay flat for proper radiography and pathology, a large, thick marker may obscure subtle pathology within the specimen. While the simple solution to this problem would be to decrease the marker size, if the marker is too small, it may be virtually impossible to hold while securing to a specimen. Existing devices also fail to standardize the method of marking specimens, thereby perpetuating the confusion and misinterpretation between the surgeon removing the specimen and the pathologist studying the specimen.
Accordingly, it is an object of the present invention to overcome the above-described drawbacks and disadvantages of existing markers.
SUMMARY OF THE INVENTION
The present invention is directed to a device for marking the margins of radiography specimens. The device includes a base and a plurality of markers detachably connected to the base. The base allows a user to easily grip the device while securing the small individual markers to a specimen. The base can take many forms from which the individual markers extend outwardly to facilitate attachment of the markers to specimens. The markers preferably include at least one aperture for receiving sutures, staples, or the like, which are used to secure the markers to specimens. After a marker is secured to a specimen, it can be broken away from the base of the device, thereby remaining secured to the specimen during radiography and pathology. The markers define distinctive, radiopaque marking indicia and/or shapes. The indicia (and/or the shapes of the markers themselves) are visible in a radiograph and indicate orientation of the specimen before the specimen was removed from the body.
One advantage of the present invention is that the device may standardize the marking system used to indicate the orientations of specimens, thereby eliminating confusion between the different medical professionals involved in treatment. Another advantage is that the device may remain fixedly secured to specimens during radiography because the device can be attached to a specimen with a suture, staple, or like connecting means, rather than relying on any pinching or squeezing elements that can accidentally release. Still another advantage is that the base of the device itself may be configured to be easily gripped during use, even though the markers themselves may be relatively small (so as to limit the amount of obstruction during x-ray). Yet another advantage is that the device may be able to retain multiple markers with various indicia, wherein one or more of the markers may be usable for the same or multiple specimens. Additionally, the device may be readily adaptable to mark all types of specimens and orientations.
These and other features and advantages of the invention are more fully disclosed or rendered apparent from the following detailed description of certain preferred embodiments of the invention, that are to be considered together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a rendering of a first embodiment of a device of the present invention for marking the margins of a specimen shown during use;
FIG. 2 is a side view of the margin marking device;
FIG. 2A is a front view of the margin marking device;
FIG. 2B is a back view of the margin marking device;
FIG. 2C is a perspective view of the margin marking device;
FIG. 3 is a plan view of a second embodiment of the margin marking device of the present invention; and
FIG. 4 is a plan view of a third embodiment of a margin marking device of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention overcomes many of the problems that arise when other radiopaque markers are used to mark radiography specimens. The advantages, and other features of the disclosed device, will become more readily apparent to those having ordinary skill in the pertinent art from the following detailed description of certain preferred embodiments taken in conjunction with the drawings which set forth representative embodiments of the present invention and wherein like reference numerals identify similar structural elements.
In FIGS. 1, 2 , and 2 A-C, numeral 110 generally refers to a margin marking device. In FIG. 1, a marker 116 is being secured to a specimen 114 to mark the margins of the specimen. The marker 116 defines an aperture 126 sized to accommodate sutures 118 , staples, or like connecting means for securing the marker 116 to the specimen 114 . The sutures 118 may be any length, although longer lengths will allow the marker 116 to be moved away from the specimen 114 during radiography, thereby reducing or eliminating possible obstruction of the specimen 114 caused by the image of the radiopaque marker 116 . A user 130 grips (with fingers, forceps, pliers, or other means) the base 112 while securing the marker 116 to the specimen 114 . Once attached, the marker 116 , because of its distinctive shape and indicia 124 , identifies the orientation of the specimen 114 prior to removal from the patient's body. The user 130 then disconnects the marker 116 from the base 112 by breaking the marker 116 at a frangible connection 122 . The user 130 may then mark different areas of the specimen 114 with the remaining markers 120 and/or may dispose of the device 110 . Because the markers 116 are radiopaque, the markers 116 will appear on a radiograph of the specimen.
Referring now to FIGS. 2A-C, the base 112 , frangible connections 122 , and markers 116 are formed by photoetching a single piece of radiopaque material. For ease of handling the desirably small markers, each marker 116 is joined to the base 112 at a respective connection 122 . The base 112 is of sufficient size to allow ease of handling the margin marking device 110 , whether a user is using forceps, fingers, or other means to hold the base 112 . The base 112 is circular, but those with ordinary skill in the pertinent art will notice that virtually any shape could be used for the base 112 including hexagons, triangles, rods, ovals, stars and other shapes. The connection 122 is strong enough to prevent inadvertent breakage, but weak enough to allow a user to disconnect the marker 116 from the base 112 once the marker 116 is attached to a specimen. The connection 122 can be a frangible connection (if the base and markers are constructed of a single piece of material, as shown), or can be any of numerous other types of connections that will allow for easy disconnection of the marker 116 from the base 112 . Other such connections include, without limitation, wires, removable or breakable pins, hooks, adhesives, or the like.
As can be seen, each marker 116 defines a distinctive shape which, once attached to a specimen, indicates orientation of the specimen prior to removal. Indicia 124 , also photoetched from the radiopaque material, aid in indicating orientation of each marker 116 . In the illustrated embodiment, the indicia 124 are letters defined by apertures photoetched through the respective marker. Since the markers 116 are formed from radiopaque material, the markers will cast an image when radiographed, thus making the indicia 124 and/or distinctive shape of the marker 116 visible. As shown, the markers 116 each indicate orientation preferably by including indicia 124 in the form of one of the following words: “cranial,” “caudal,” “medial,” “deep,” “lateral,” or “skin,” and each marker further defines a peripheral shape forming a graphical representation of the respective indicia.
One of ordinary skill in the pertinent art will recognize that the indicia 124 can be formed through processes other than photoetching. For example, indicia 124 also may be formed in the radiopaque markers 116 by stamping, laser cutting, or by other means. In FIGS. 2A-C, the indicia 124 are defined by one or more apertures formed through the respective marker 116 , those apertures defining the shapes of letters. Alternatively, the indicia can comprise distinctive shapes or other forms to provide unique identifying information. One of ordinary skill in the pertinent art also will recognize that the indicia themselves may be radiopaque. This method would allow the indicia to be mounted on or embedded in a non-radiopaque marker. In this case, indicia may be applied to each marker by printing the indicia thereon with a radiopaque ink or other suitable material. Radiopaque indicia could also be embedded within non-radiopaque markers while the markers are being formed (i.e., during casting, injection molding, or some other process).
It will be apparent to one of ordinary skill in the pertinent art that the markers 116 , including the indicia 124 and/or the distinctive shapes of the markers, can define virtually any information relevant to the marking of specimens. Additionally, the marking system indicated, while directed to breast specimens, can be utilized with obvious modifications to mark any type of specimen, from any body part, for any purpose. A non-exhaustive list of possible alternative indicia include the words: “breast,” “first,” “second,” “left,” “right,” “malignant,” “base,” “testicle,” “anterior,” etc. In addition, each marker may define a respective shape forming a graphical representation of the representative indicia or otherwise conveying desired information. Each marker 116 defines an aperture 126 large enough to accommodate sutures, staples or other attachment elements as desired, which allow fast attachment of the marker 116 to a specimen.
In the currently preferred embodiment of FIGS. 2A-C, the margin marking device 110 is approximately one inch in diameter, with each marker 116 defining a footprint of approximately 0.2 inches by 0.2 inches. The small size of the individual markers 116 allows for accurate marking of specimen margins and decreases the amount of specimen obstructed by the marker's image during xray. The base 112 and the markers 116 are both approximately 0.005 inch thick, which reduces the possibility of markers 116 impeding the required flattening of a specimen during radiography. Those of ordinary skill in the pertinent art will note that the thickness and size of the markers 116 can vary depending on any of numerous different factors, such as the size of the specimen to which the markers 116 will be affixed (i.e., larger markers can be attached to larger specimens).
Those of ordinary skill in the pertinent art also will recognize that the margin marking device 110 can be made from any of numerous different materials that are currently or later become known for performing the function of the markers described herein. While FIG. 1 shows a marking device 110 made from a single piece of stainless steel, other radiopaque materials may be used, including platinum, titanium, lead, other metals or alloys, non-radiopaque materials with radiopaque coatings, or any combination of any of the foregoing. Additionally, non-radiopaque markers may be used with radiopaque indicia fixed thereon. In addition, the markers could be made of partially radiopaque, partially radiolucent material as disclosed in U.S. patent application Ser. No. 09/372,835, filed Aug. 12, 1999, entitled “An intermediate density marker and a method for using such a marker for radiographic examination”, which is assigned to the assignee of the present invention and is hereby expressly incorporated by reference as a part of the present disclosure. This material would allow the image of the marker to appear on a radiograph yet would not obstruct any underlying structure of the specimen from being visible through the image of the marker on the radiograph.
Photoetching is the currently preferred method of making the margin marker system, since this process is relatively cost-effective, produces a precise reproduction of the original design, and produces a marking device that is burr and stress free. Photoetching also allows for a simple way to manufacture the entire device (base, connections, and markers) as a single piece. Other manufacturing processes such as stamping, casting, injection-molding, laser-cutting, and the like equally may be used.
Referring to FIG. 3, a margin marking device 310 defines a hexagonal base 312 . As will be appreciated by those of ordinary skill in the pertinent art, margin marking device 310 utilizes the same principles of the margin marking device 110 of FIGS. 1 and 2 A-C. Accordingly, like reference numerals preceded by the numeral “3,” instead of the numeral “1,” are used to indicate like elements. Each base 312 is connected to plate 316 at a respective connection 322 . Each plate 316 is radiopaque and is photoetched with indicia 324 defining a respective unique orientation. Each plate 316 is connected to a respective wire 328 which is, in turn, connected to respective closed ring defining an aperture. The aperture 326 of each closed ring is sized to accommodate sutures, staples, or like connecting means, and may be fabricated from any of numerous materials available in the art and those developed in the future.
The length of each wire 328 may be set as desired. Alternatively, the wire 328 may be eliminated and each closed ring may be directly connected to the respective plate 316 . The presence of the wire 328 is particularly useful for extremely small specimens, where little or no obstruction of the radiograph by the plate 316 would be acceptable. In this case, the closed ring can be fixed to a specimen, and the respective plate 316 can be moved away from the specimen during xray procedures, thereby eliminating possible obstruction of relevant portions of the specimen by the radiopaque plate 316 . The wire 328 may be fabricated from radiopaque, non-radiopaque material, or partially radiopaque, partially radiolucent. A radiopaque wire 328 would be particularly useful, as it would be visible on a radiograph of the specimen, thereby defining a line from the respective plate 316 to the point of connection on the specimen. This would allow those viewing the radiograph to pinpoint the location of a particular point of interest on the specimen, without blocking that point with a radiopaque plate 316 .
FIG. 4 shows a margin marking device 410 particularly well-suited to known methods of plastic construction. A rod-shaped base 412 is connected to markers 416 at frangible connections 422 . Each marker 416 defines unique indicia, shown typically at 424 , indicative of a respective orientation. The indicia 424 may be defined by one or more apertures formed through the respective marker 416 , wherein the apertures define the shapes of letters and/or other unique identifying information. Alternatively, the indicia 424 may be applied to each marker 416 by printing the indicia thereon with a radiopaque ink or other suitable material. An aperture 426 is present in each marker 416 for attaching sutures, staples, or like attachment means. The margin marking device 410 can be molded as one piece of plastic or other suitable material. Each plastic marker 416 may be sufficiently radiopaque to mark the specimen. Alternatively, a radiopaque coating may be applied to each marker 416 , or radiopaque material may be embedded or attached to the markers 416 in a manner known to those of ordinary skill in the pertinent art.
Although FIGS. 1 through 4 show margin marking devices having a plurality of markers connected to a base, one of ordinary skill in the pertinent art will recognize that the markers individually are novel in their own right. While the small size of the markers necessitates the use of a base to hold the markers as those markers are being fixed to specimens, this base is not necessary for larger markers, which can be stored in a container until they are secured to a specimen. These larger markers could be used to mark the margins of larger specimens, specimens where obstruction caused by the image of the marker during radiography is less of a concern, or for markers made of partially radiopaque, partially radiolucent material. The novelty of the present invention is not lost with an increase of marker size and the elimination of the base, as the advantages of a marker that remains secured to a specimen and standardizes the method of marking specimens still exist.
The skilled artisan also will recognize that any or all components of the margin marking device of the present disclosure (including the base and markers) could be made from many materials presently available in the art or invented in the future. If a marker is made from radiopaque material (or non-radiopaque material coated with radiopaque coating), indicia can be formed on the marker, either by photoetching, stamping or other means. The markers themselves also may define a distinctive shape without indicia, provided the markers are of such a shape as to clearly indicate a unique orientation or other requisite identifying information. Markers also may be completely non-radiopaque, with radiopaque indicia printed or otherwise fixed thereon. It also will be apparent to those of ordinary skill in the pertinent art that the base and markers may be manufactured from more than one piece of material or various combinations of materials. After manufacture, the markers could be attached to the base in any of numerous different ways that allow for disconnection during use. As indicated above, these points of connection between the markers and the base may be formed by hooks, wire, pins, frangible portions, or like connections.
Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the scope and range of the equivalents of the invention as defined by the appended claims. | A marking device for defining the margins and orientation of radiography specimens includes a plurality of visually distinctive markers joined by a base that holds the markers until the markers are secured to a specimen. The base serves as a holder for the individual markers as the markers are secured to a specimen with sutures or staples, at which time the markers are disconnected from the base. One or more markers may be secured to a specimen as needed to define the orientation of the specimen. By securing markers to specific locations on a specimen, a surgeon can indicate to radiologists and pathologists the specimen's orientation in the body before removal, thus aiding in future study of the specimen. Since the markers are made either wholly or partially from radiopaque material, the markers are visible when radiographed. | 0 |
BACKGROUND
[0001] The present invention relates generally to a thermal barrier coating system for a component that is exposed to high temperatures, such as a gas turbine engine component (e.g., blades, vanes, etc.). More particularly, the present invention relates to a coating including a low aluminum content, where the coating is suitable for use as a bondcoat in a thermal barrier coating system.
[0002] A gas turbine engine component (“component”), such as a blade tip, blade trailing edge, blade platform, vane trailing edge, or vane platform, is typically exposed to a high temperature and high stress environment. The high temperature environment may be especially problematic with a superalloy component. Namely, the high temperatures may cause the superalloy to oxidize, which then decreases the life of the component. In order to extend the life of the component, a thermal barrier coating system (TBC system) may be applied to the entire superalloy component or selective surfaces, such as surfaces of the superalloy component that are exposed to the high temperatures and other harsh operating conditions. A TBC system reduces the temperature of the underlying material (also generally called the “substrate”) and helps inhibit oxidation, corrosion, erosion, and other environmental damage to the substrate. Desirable properties of a TBC system include low thermal conductivity and strong adherence to the underlying substrate.
[0003] The TBC system typically includes a metallic bondcoat and a ceramic topcoat (i.e., a thermal barrier coating or TBC topcoat). The bondcoat is applied to the substrate and aids the growth of a thermally grown oxide (TGO) layer, which is typically aluminum oxide (Al 2 O 3 or “alumina”). Specifically, prior to or during deposition of the TBC topcoat on the bondcoat, the exposed surface of the bondcoat can be oxidized to form the alumina TGO layer. The TGO forms a strong bond to both the topcoat and the bondcoat, and as a result, the TGO layer helps the TBC topcoat adhere to the bondcoat. The bond between the TGO and the topcoat is typically stronger than the bond that would form directly between the TBC topcoat and the bondcoat. The TGO also acts as an oxidation resistant layer, or an “oxidation barrier”, to help protect the underlying substrate from damage due to oxidation.
[0004] During use in a gas turbine engine, the TGO thickens as aluminum diffuses into the TGO from the bondcoat and oxygen diffuses into the TGO from the combustion products and cooling air in the turbine gas path, reacting to form more alumina TGO. As the TGO thickness increases, it carries a proportionally larger share of any stresses that arise in the TBC system. Eventually, this share of the stress exceeds the strength of the TGO, leading to its failure. Once the TGO fails, the TBC topcoat spalls from the bondcoat because there is little to no TGO to provide adhesion.
[0005] Most bondcoats are designed to maintain slow growth of the TGO and to insure that the TGO consists of pure alumina. If the amount of aluminum that diffuses from the bondcoat to the TGO is insufficient to sustain growth of pure alumina, spinel oxide may form. Spinels grow quickly because they do not act as oxidation barriers. A TGO containing spinels has a significantly shorter life than a pure alumina TGO because spinels are not as strong as pure alumina.
[0006] The TBC topcoat may consist of a zirconia material that includes yttria as a stabilizing material. The primary role of the TBC topcoat is to provide insulation, thereby reducing the temperature of the bondcoat and the substrate. Thus, TBC ceramic topcoats are designed to have low thermal conductivity. There are various techniques of applying the TBC topcoat on the component, including air plasma spraying, vapor deposition and thermal spraying methods such as a high velocity oxy-fuel method.
[0007] The bondcoat is important to the life of the TBC system. If the bondcoat fails, the TBC topcoat may spall, after which the TBC system quickly deteriorates. TBC topcoat spallation exposes the bondcoat to the high-temperature, oxidizing environment of the turbine gas path, as well as to any corrosive species that may be in the gas path arising from impurities in the fuel and ingested fine particulates or contaminants. The higher temperatures and any deposits of contaminants accelerate the oxidation or corrosion of the bondcoat, eventually consuming the bondcoat. Once the bondcoat is consumed, the harsh environment attacks the underlying substrate. A deteriorated TBC system is undesirable because it may shorten the life of the component, and at the very least, requires the component to be taken out of service in order for the TBC system to be repaired. Whenever possible, the TBC system is removed and replaced prior to its complete failure to ensure no degradation of the underlying substrate.
[0008] In addition to its role in protecting the substrate from oxidation and corrosion, it is preferable that the bondcoat adheres well to the substrate with minimal reaction and interdiffusion.
BRIEF SUMMARY
[0009] The present invention is a bondcoat suitable for use with a superalloy gas turbine engine component. In one embodiment, the bondcoat includes about 5 to about 10 weight percent of aluminum (Al), about 10 to about 18 weight percent of cobalt (Co), about 4 to about 8 weight percent of chromium (Cr), about 0 to about 1 weight percent of hafnium (Hf), about 0 to about 1 weight percent of silicon (Si), about 0 to about 1 percent of yttrium (Y), about 1.5 to about 2.5 weight percent of molybdenum (Mo), about 2 to about 4 weight percent of rhenium (Re), about 5 to about 10 weight percent of tantalum (Ta), about 5 to about 8 weight percent of tungsten (W), about 0 to about 1 weight percent of zirconium (Zr), and a remainder of nickel (Ni).
[0010] In another embodiment, the bondcoat includes about 5 to about 10 weight percent of Al, about 10 to about 18 weight percent of Co, about 4 to about 8 weight percent of Cr, about 0 to about 1 weight percent of Hf, about 0 to about 1 weight percent of Si, about 0 to about 1 percent of Y, about 1.5 to about 2.5 weight percent of Mo, about 2 to about 4 weight percent of Re, about 5 to about 10 weight percent of Ta, about 5 to about 8 weight percent of W, about 0 to about 1 weight percent of zirconium Zr, about 10 to about 40 weight percent of platinum (Pt) or other noble metals, such as palladium (Pd) or iridium (Ir), and a remainder of nickel (Ni).
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a turbine blade.
[0012] FIG. 2 is a cross-sectional view of the turbine blade of FIG. 1 , where a section has been taken at line 2 - 2 (shown in FIG. 1 ), and shows a TBC system overlying the body of the turbine blade.
DETAILED DESCRIPTION
[0013] The present invention is a coating that is suitable for use as a bondcoat in a thermal barrier coating system. In one embodiment, the composition of the inventive coating includes about 5 to about 10 weight percent of Al, about 10 to about 18 weight percent of Co, about 4 to about 8 weight percent of Cr, about 0 to about 1 weight percent of Hf, about 0 to about 1 weight percent of Si, about 0 to about 1 percent of Y, about 1.5 to about 2.5 weight percent of Mo, about 2 to about 4 weight percent of Re, about 5 to about 10 weight percent of Ta, about 5 to about 8 weight percent of W, about 0 to about 1 weight percent of Zr, and a balance (or “remainder”) of Ni. In another embodiment, about 10 to about 40 weight of Pt or other noble metals, such as Pd, Ir or combinations thereof, are substituted for some or all of the balance of Ni. The exact composition of the bondcoat may be modified within the broad ranges in order to form a bondcoat that exhibits desirable mechanical and chemical properties that are compatible with the underlying substrate.
[0014] The bondcoat of the present invention may be applied (or “deposited”) to a suitable substrate, including a superalloy gas turbine engine component, in order to protect the substrate from oxidation, corrosion, erosion, and other adverse effects attributable to a harsh operating environment. The inventive bondcoat is particularly suitable for use with a component formed of a single crystal superalloy that is commonly designated a “fourth generation single crystal superalloy.” The fourth generation single crystal superalloy contains high levels of ruthenium and rhenium, and exhibits enhanced creep strength compared to other single crystal alloys. An example of a fourth generation single crystal superalloy is described in U.S. Pat. No. 6,007,645, entitled, “Advanced High Strength, Highly Oxidation Resistant Single Crystal Superalloy Composition Having Low Cr Content.”
[0015] One preferred composition of the bondcoat when used in conjunction with the fourth generation single crystal superalloy substrate described in U.S. Pat. No. 6,007,645 is: about 7.5 weight percent of Al, about 14 weight percent of Co, about 6 weight percent of Cr, about 0.5 weight percent of Hf, about 0.5 weight percent of Si, about 0.5 percent of Y, about 2.0 weight percent of Mo, about 3 weight percent of Re, about 7.5 weight percent of Ta, about 6.5 weight percent of W, about 0.5 weight percent of Zr, and about 51.5 weight percent of Ni. Another preferred composition is about 7.5 weight percent of Al, about 14 weight percent of Co, about 6 weight percent of Cr, about 0.5 weight percent of Hf, about 0.5 weight percent of Si, about 0.5 percent of Y, about 2.0 weight percent of Mo, about 3 weight percent of Re, about 7.5 weight percent of Ta, about 6.5 weight percent of W, about 0.5 weight percent of Zr, about 25 weight percent of Pt (or Pd or Ir), and about 26.5 weight percent of Ni.
[0016] The inventive bondcoat provides an oxidation resistant coating for a TBC system. After cycling a bondcoat having a composition in the ranges disclosed above in a burner rig at about 1148.89° C. (about 2100° F.), it was found that there was no evidence of bondcoat failure by oxidation or cracking after more than 100 cycles and more than 100 hours.
[0017] It has been found that when many existing TBC system bondcoats are applied to a single crystal superalloy substrate, such as the fourth generation single crystal superalloy substrate, aluminum diffuses from the bondcoat to the underlying substrate because the bondcoat typically has a higher aluminum content than the superalloy substrate. In addition, nickel and cobalt diffuse from the substrate into the bondcoat. It is desirable to minimize this interdiffusion in order to maximize the aluminum available for the stable and slow growth of a pure alumina TGO. Furthermore, when the single crystal superalloy substrate contains high concentrations of refractory metals such as rhenium (Re), the aluminum, nickel, and cobalt interdiffusion can result in the formation of deleterious topographically close packed (TCP) phases (i.e., phase instability) near the bondcoat-substrate interface. The phase instability adversely affects the mechanical properties of the superalloy, and essentially weakens the superalloy substrate. The deleterious phases act as sites for crack initiation because these phases typically form weak, high-angle grain boundaries with the superalloy substrate. If the degree of phase instability is extensive enough to consume a fair percentage of the substrate forming the component, the integrity of the component may be compromised.
[0018] The present invention is a bondcoat that includes a lower aluminum content than conventional bondcoats, while at the same time exhibits adequate oxidation resistance for a high-pressure turbine engine environment. The lower content of aluminum in the bondcoat contributes to a lower amount of diffusion of aluminum from the bondcoat to a superalloy substrate. As a result, the bondcoat of the present invention is more compatible with a fourth generation single crystal superalloy substrate, as well as other alloy substrates having high concentrations of refractory metals, than many existing bondcoats having a higher aluminum content. The possibility that the fourth generation single crystal superalloy substrate will form a TCP phase is decreased with a bondcoat of the present invention.
[0019] The aluminum content in a bondcoat aids the formation of an alumina TGO layer. As mentioned in the Background section, this TGO layer serves at least two purposes. First, the oxide layer acts as a barrier to oxidation of the underlying substrate (e.g., the fourth generation single crystal superalloy). Second, the TBC topcoat is inclined to chemically bond to the oxide layer. In a sense, the oxide layer acts as an adhesive to bond the TBC topcoat to the bondcoat. Despite a lower aluminum content than existing-bondcoats, the bondcoat of the present invention contains a sufficient amount of aluminum to aid the growth of an oxide layer that is thick enough to act as an oxidation barrier. The aluminum in combination with the yttrium content of the inventive bondcoat aids the slow growth of a spinel-free oxide layer with good adhesion to both the TBC topcoat and to the bondcoat.
[0020] It has been found that the bondcoat of the present invention exhibits a coefficient of thermal expansion (CTE) of about 6.4 microns/inch/° F. This value is very similar to the CTE of a state-of-the-art superalloy, including a fourth generation superalloy. The propensity for thermal cycle induced cracking or failure of the bondcoat in a TBC system increases with an increase in the difference of CTE values between the bondcoat and the substrate on which it is applied. For this reason, it is preferable to minimize the difference in the CTE values, and even more preferable to have the same CTE value for the bondcoat and the substrate.
[0021] In addition to being used as a bondcoat in a thermal barrier coating system, a bondcoat of the present invention may also be a stand alone environmental coating, such as an oxidation and corrosion resistant coating.
[0022] FIG. 1 is a perspective view of turbine blade 10 of a gas turbine engine. Turbine blade 10 includes platform 12 and body 14 . Body 14 of turbine blade 10 is formed of a fourth generation single crystal superalloy in accordance with the composition described in U.S. Pat. No. 6,007,645, where the specific composition exhibits a CTE of about 6.4 microns/inch/° F. Turbine blade 10 is exposed to high temperatures and high pressures during operation of the gas turbine engine. In order to extend the life of turbine blade 10 and protect turbine blade 10 from high stress operating conditions and the resulting oxidation and corrosion, TBC system 16 (shown in FIG. 2 ) is applied over body 14 of turbine blade 10 .
[0023] The exact placement of TBC system 16 depends upon many factors, including the type of turbine blade 10 employed and the areas of turbine blade 10 that are exposed to the most stressful conditions. For example, in alternate embodiments, TBC system 16 may be applied over a part of the outer surface of body 14 rather than over the entire outer surface of body 14 . Furthermore, because bondcoat 18 may also be a stand-alone environmental coating, body 14 may be fully covered with bondcoat 18 and only partly covered with ceramic layer 20 . If turbine blade 10 includes cooling holes leading from internal cooling passages to the outer surface of body 14 , TBC system 16 may also be applied to the surface of the cooling holes.
[0024] Turbine blade 10 is shown as an example of a gas turbine engine component that requires the use of a TBC system. However, the bondcoat of the present invention may be used with any suitable component for which it is desirable to protect against its operating environment, including other components in a gas turbine engine.
[0025] FIG. 2 is a sectional view of turbine blade 10 , where a section is taken at line 2 - 2 in FIG. 1 . TBC system 16 is applied to an exterior surface of body 14 . TBC system 16 includes bondcoat 18 and ceramic layer 20 . Bondcoat 18 overlays and bonds to body 14 , while ceramic layer 20 overlays bondcoat 18 . In the embodiment shown in FIG. 2 , bondcoat 18 is applied to body 14 in a thickness range of about 0.0127 millimeters (about 0.5 mils) to about 0.254 millimeters (about 10 mils). Ceramic layer 20 may be any thermal barrier coating (or “topcoat”) that is suitable for use on alumina-forming bondcoats and/or alloys, such as, but not limited to, zirconia stabilized with yttria (Y 2 O 3 ), gadolinia (Gd 3 O 3 ), ceria (CeO 2 ), scandia (Sc 2 O 3 ), or other oxides. Ceramic layer 20 is deposited in a thickness that is sufficient enough to provide the required thermal protection for bondcoat 18 .
[0026] Bondcoat 18 consists essentially of about 5 to about 10 weight percent of Al, about 10 to about 18 weight percent of Co, about 4 to about 8 weight percent of Cr, about 0 to about 1 weight percent of Hf, about 0 to about 1 weight percent of Si, about 0 to about 1 percent of Y, about 1.5 to about 2.5 weight percent of Mo, about 2 to about 4 weight percent of Re, about 5 to about 10 weight percent of Ta, about 5 to about 8 weight percent of W, about 0 to about 1 weight percent of Zr, and a balance of Ni.
[0027] In another embodiment, bondcoat 18 consists essentially of about 5 to about 10 weight percent of Al, about 10 to about 18 weight percent of Co, about 4 to about 8 weight percent of Cr, about 0 to about 1 weight percent of Hf, about 0 to about 1 weight percent of Si, about 0 to about 1 percent of Y, about 1.5 to about 2.5 weight percent of Mo, about 2 to about 4 weight percent of Re, about 5 to about 10 weight percent of Ta, about 5 to about 8 weight percent of W, about 0 to about 1 weight percent of Zr, about 10 to about 40 weight percent of Pt, and a balance Ni. Alternatively, other noble metals such as Pd or Ir, or combinations thereof, can be substituted for Pt.
[0028] Bondcoat 18 includes a lower level of aluminum as compared to conventional bondcoats, and as a result, less aluminum diffuses from bondcoat 18 to body 14 . This helps to minimize the formation of a TCP phase in body 14 that is attributable to the diffusion of aluminum from bondcoat 18 to body 14 . As previously stated, body 14 is formed of superalloy that exhibits a CTE of about 6.4 microns/inch/° F. Bondcoat 18 also exhibits a CTE of about 6.4 microns/inch/° F. Because the CTE values for bondcoat 18 and body 14 are similar, the propensity for thermal cycle induced cracking or failure of bondcoat 18 is decreased.
[0029] Bondcoat 18 in accordance with the present invention may be applied to body 14 (or another substrate in alternate embodiments) with any suitable technique, including thermal spray processes (e.g., plasma spray deposition or high velocity oxyfuel (HVOF) deposition), physical vapor deposition (e.g., cathodic arc deposition), or chemical vapor deposition. In one embodiment, a vacuum plasma spray deposition method is used to apply bondcoat 18 to body 14 . As known in the art, vacuum plasma spray deposition is a thermal spray process that is carried out in a vacuum chamber. A plasma spray torch, which applies a powdered form of the coating onto a substrate, typically operates in a low-pressure environment of an inert gas, such as Argon. The plasma spray torch is typically manipulated by a control mechanism that allows the torch to move at least in one direction relative to the substrate.
[0030] In one method of applying bondcoat 18 to body 14 , a vacuum plasma spray process is used, where the process utilizes a deposition chamber pressure ranging from about 13.33 kilopascals (kPa) (about 100 Torr) to about 40 kPa (about 300 Torr), a plasma torch current ranging from about 400 amperes (A) to about 900 A, and a plasma torch voltage ranging from about 50 volts (V) to about 85 V. The plasma spray torch is controlled by a 3 to 5 axis robot, which positions the torch about 15.24 centimeters (about 6 inches) to about 50.8 centimeters (about 20 inches) from body 14 . During the deposition process, body 14 exhibits a temperature in a range of about 815.56° C. (about 1500° F.) to about 982.22° C. (about 1800° F.). In alternate embodiments, a vacuum plasma spray method including different parameters may be used.
[0031] In another embodiment, a cathodic arc deposition method, which is a type of physical vapor deposition, is used to apply bondcoat 18 to body 14 . As known in the art, in a cathodic arc deposition method, a source material and a substrate to be coated are disposed in an evacuated deposition chamber. In the cathodic arc deposition embodiment, a deposition chamber pressure ranges from about 0.133 kPa (about 1 Torr) to about 13.33 kPa (about 100 Torr). Argon gas, flowing at a rate from about 100 standard cubic centimeters per minute (sccm) to about 500 sccm, maintains the chamber pressure in the desired range. Arc currents ranging from about 300 A to about 650 A are established and a negative bias from about 30 V to about 100 V is applied to body 14 . In alternate embodiments, a cathodic arc deposition method including different parameters may be used.
[0032] The terminology used herein is for the purpose of description, not limitation. Although the present invention has been described with reference to a preferred embodiment, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | A coating suitable for use as a bondcoat for a thermal barrier coating system includes about 5 to about 10 weight percent of aluminum (Al), about 10 to about 18 weight percent of cobalt (Co), about 4 to about 8 weight percent of chromium (Cr), about 0 to about 1 weight percent of hafnium (Hf), about 0 to about 1 weight percent of silicon (Si), about 0 to about 1 percent of yttrium (Y), about 1.5 to about 2.5 weight percent of molybdenum (Mo), about 2 to about 4 weight percent of rhenium (Re), about 5 to about 10 weight percent of tantalum (Ta), about 5 to about 8 weight percent of tungsten (W), about 0 to about 1 weight percent of zirconium (Zr), and a remainder of nickel (Ni). | 2 |
FIELD OF THE INVENTION
[0001] The invention relates to a method and to an apparatus for automatically querying databases to extract trademark information and/or domain name registration information. The invention finds practical applications in identifying registration domain names that are identical or confusing with registered trademarks and/or with other registered domain names. The invention can also be used for identifying names for which trademark and/or domain names registrations are available.
BACKGROUND OF THE INVENTION
[0002] The Internet allows access to many databases that provide information on registered trademarks, in particular, trademark ownership details. Among these databases are the USPTO (United States Patent and Trademark Office) and CIPO (Canadian Intellectual Property Office).
[0003] Also available to the public are Internet sites which provide information on Domain name registration and/or ownership. Some examples are www.nsi.com, www.internic.net and www.internic.ca. A common name for the database sites, which produce domain name ownership information, is “WHOIS”.
[0004] In the present specification, the following definitions apply:
[0005] 1. “BOT” implies an automated software implemented agency that can access Internet sites and retrieve data;
[0006] 2. “WHOIS” A database containing Domain name registration and/or ownership details;
[0007] 3. “DATABASE” refers to a database that provides information on registered trademarks, in particular, trademark ownership details or to a database containing Domain name registration and/or ownership details. CIFO, USPTO and WHOIS are considered to be databases;
[0008] 4. “REGISTRANT” person or entity which has registered a Domain or Trademark;
[0009] 5. “NAME” refers to registered trademarks, product names and domain names;
[0010] 6. OWNER” the rightful owner of a NAME;
[0011] 7. “OTHERS” A term used to indicate a person other then the OWNER;
[0012] 8. “PRODUCT” name refers to a name that an “OWNER” has not registered as trademark or registered as a domain name;
[0013] 9. “PARKED” an Internet site accessible under a domain name that has been registered but the site has not yet been activated;
[0014] 10. “FOR SALE” an Internet Domain name that has been registered and is being offered for sale;
[0015] 11. “CONSTRUCTION” an Internet Site that has posted a message stating that it is under construction;
[0016] 12. “STATUS” indicates whether an Internet site is under construction, for sale , parked or active;
[0017] 13. “META TAGS” is information hidden from view in an Internet site. Typically, Search engines use these words to classify the site;
[0018] 14. “KEYWORDS” information used in an Internet site that describe the site. This information may be in the form of meta tags or information in another form, for example words that are apparent to the visitor of the site;
[0019] 15. “BAD FAITH” term indicating that a NAME was registered for the purpose of being sold or to divert business by having a close spelling to that of an existing Domain name, where the NAME is registered by an entity of person other than the owner of the domain name;
[0020] 16. “BAD FAITH ANALYSIS” analysis for finding the registrant of a Domain name and then searching for any other domain name that this registrant may have registered. Optionally, the status of the sites under the located domain names is also investigated. This information is used to determine the history and intent of the registrant;
[0021] 17. “CONFLICT” refers to any of the following combinations.
1. OWNER trademark vs OTHER trademarks 2. OWNER trademark vs OTHER domain names 3. OWNER Domain name vs OTHER trademarks 4. OWNER Domain name vs OTHER Domain names 5. OWNER Product name vs OTHER trademarks or Domain names.
[0022] The use of the Internet for e-commerce has produced three areas of questionable business tactics, namely:
[0023] 1. Cybersquatting.
[0024] Here an individual has registered a domain name using the trademark registered by another with the intent to later sell the Domain name to the original trademark owner.
EXAMPLE
[0025] Consider the famous trademark “ABC”. If the owner of the mark has not registered a Domain name www.abc.com then any person can do so. These being done in the hope that the company “ABC” will offer a substantial amount of money to the registrant to purchase the name. Consider also the situation whereby ABC has registered the name www.abc.com. A Cybersquatter could register www.abc-europe.com again hoping to sell the domain name back to ABC.
[0026] 2. Typopiracy.
[0027] In this case an individual has registered a Domain name with a slight variation in spelling from that of a competitor. The individual hopes to capitalize on spelling errors to divert a customer to his site.
EXAMPLE
[0028] Consider the registered name www.baby.com, which is a fictitious store for baby clothing. A typopirate could register a name www.babie.com This individual could operate a baby clothing store and capitalize on typo errors to divert business to his site.
[0029] 3. Meta Tag and Keywords.
[0030] In this case the individual has hidden his competitor trademarks or keywords in Meta Tags. If a potential customer uses a search engine to look for a particular product or service he may be diverted to a competitor.
EXAMPLE
[0031] Consider the case where an individual hides the name “baby clothing” in his meta tags. A user using a search engine to find the “baby.com” site would receive a list of sites that relate to “baby”. Amongst them would be the pointer to a competitive Domain.
[0032] At the present time an individual who wants to perform a correlation between a registered trademark and registered domain names must manually access a database then type the name to be searched. This must be repeated for each database of interest. For example a user would have to manually access the USPTO, CIPO and the pertinent WHOIS site. In some cases the WHOIS site accessed may not contain the required information and the USER would then have to try another WHOIS site.
[0033] In the case of a search involving multiple spellings the individual would have to repeat the search for each spelling variation. Some sites allow for the use of wild cards to effect a multiple spelling search. However, this search facilitation is not consistent among different databases and the user must accommodate this.
[0034] After all the sites and spelling combinations have been searched the user then correlates the results by hand and manually types a report.
[0035] As an illustration consider a search for the name “copitrak”. Copitrak can be spelled with either a c, k, or ck. Also the middle letter “i” can be replaced by a “y”. The search would involve six names. Since the Domain names have four suffixes of interest that is com, net, org, ca and at least two possible trademark registrations that is CIPO and USPTO the total number of searches could amount to thirty six. This only returns ownership information. To obtain the status of these site would require twenty-four site visits. Total number of access now equals sixty.
[0036] To do a wild card search, that is, look for sites that have the following pattern www.e-copitrak.com or www.copitrak-europe.com where the search is done as follows *copitrak* etc would increase the number of accesses.
[0037] Against this background it appears that a need exists in the industry to provide a method and an apparatus for performing correlation between trademark information and domain name information that avoids or at least alleviates the disadvantages associated with prior art techniques.
SUMMARY OF THE INVENTION
[0038] Under a broad aspect, the invention provides a method for performing trademark and domain name information analysis. With this method the user is prompted under control of a client system to enter information about a certain name. The name may be a registered trademark, a registered domain name or a name that is neither a registered trademark nor a registered domain name. On the basis of the information entered by the user, a query request is formulated and sent by the client system to at least one database containing trademark information and to at least one database containing domain name information. The responses to the query requests are received and processed by the client system. Next, the client system displays to the user trademark information related to the name, associated with domain name information also related to the name.
[0039] This method is beneficial by its ability to seek and obtain automatically by the client system responses to the queries made at the trademark and domain name databases and also to process and correlate the information in the responses such that trademark information related to a given name is associated with domain name information also related to the name.
[0040] Optionally, the method allows formulating query requests based on variations in the spelling of the certain name. For example, the user may indicate alternative spelling of the name or use wildcard characters. The query formulation then includes the step of breaking down the entry of the user into a plurality of search inquiries, each inquiry corresponding to a certain spelling of the name.
[0041] Under a second broad aspect, the invention provides a method for performing domain name information analysis. With this method the user is prompted under control of a client system to enter information about a certain name owned by a certain entity. The name may be a registered trademark, a name that is neither a registered trademark nor a registered domain name, or a registered domain name. On the basis of the information entered by the user, a query request is formulated and sent by the client system to at least one database containing domain name information. The query request is a message to extract from the domain name information database domain names that are similar to the certain name entered by the user. The response to the query request is received and processed by the client system. The processing includes a filtering function allowing displaying to the user the name owned by the certain entity versus domain names owned by entities that belong to group of entities excluding the certain entity owning the name.
[0042] Under a third broad aspect, the invention provides a method for performing trademark information analysis. With this method the user is prompted under control of a client system to enter information about a certain name owned by a certain entity. The name may be a registered trademark, a name that is neither a registered trademark nor a registered domain name, or a registered domain name. on the basis of the information entered by the user, a query request is formulated and sent by the client system to at least one database containing trademark information. The query request is a message to extract from the trademark information database registered trademarks that are similar to the certain name entered by the user. The response to the query request is received and processed by the client system. The processing includes a filtering function allowing displaying to the user the name owned by the certain entity versus domain names owned by entities that belong to group of entities excluding the certain entity owning the name.
[0043] The invention also provides a computer readable storage medium containing a program element for execution by a computing device, the program element implementing the method under the first broad aspect of the invention.
[0044] The invention also provides a computer readable storage medium containing a program element for execution by a computing device, the program element implementing the method under the second broad aspect of the invention.
[0045] The invention also provides a computer readable storage medium containing a program element for execution by a computing device, the program element implementing the method under the third broad aspect of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] A detailed description of examples of implementation of the present invention is provided hereinbelow with reference to the following drawings, in which:
[0047] [0047]FIG. 1 is a block diagram of a network arrangement allowing a client system to retrieve domain name and trademark information from remote databases;
[0048] [0048]FIG. 2 is block diagram of the client system;
[0049] [0049]FIG. 3 is a functional block diagram of the program element executed on the client system; and
[0050] FIGS. 4 to 10 are representations of Graphical User Interfaces (GUI) that illustrate the functionality of the program element executed by the client system.
[0051] In the drawings, embodiments of the invention are illustrated by way of example. It is to be expressly understood that the description and drawings are only for purposes of illustration and as an aid to understanding, and are not intended to be a definition of the limits of the invention.
DETAILED DESCRIPTION
[0052] [0052]FIG. 1 illustrates a network arrangement 10 comprising a client system 12 that communicates with a plurality of databases 14 - 20 through the Internet 22 . Some of the databases 14 - 20 contain registered trademark information. Possible examples include the database operated by the United States Patent and Trademark Office and the database operated by Canadian Intellectual Property Office. Some of the databases 14 - 20 also contain registered domain name information. Examples include the databases at the following sites: www.nsi.com, www.internic.net and www.iternic.ca.
[0053] The client system 12 is illustrated in greater detail at FIG. 2. The client system includes a Central Processing Unit 24 , a memory 26 , an Input/Output (I/O) interface 28 and a data bus 30 . The memory contains a program element that is executed by the CPU 24 to donate to the client system 12 a functionality that will be described in detail later. The I/O port 28 is the agency through which the CPU 24 communicates with the external world. The data bus 30 allows the components of the client system 12 to exchange messages between them.
[0054] The architecture of the program element 32 is illustrated at FIG. 3. The program element 32 has a central manager 34 that is responsible for the overall control and processing done by the program element 34 . A set of GUIs 38 communicate with the central manger 34 . The GUIs 38 display information to the user on a monitor (not shown) and also constitute an agency through which the user can input data to the central manager 34 .
[0055] Finally, the program element 32 also includes an Internet Interface 34 through which messages exchanged between the central manager and the databases 14 - 20 transit.
[0056] The functionality of the program element 34 will now be described.
[0057] Typopiracy Search
[0058] In order to initiate a typopiracy search, the user enters name for which an analysis is required through a GUI shown in FIG. 4. As shown, the user is not restricted to inputting precise names 42 since the program entity 32 allows for variations due to spelling as well as variations due to prefixes and suffixes by respectively allowing the use of shorthand and wildcards. This enables the generation of a plurality of search inquiries that include all permutations of that name. FIG. 4 further shows that below each name 42 , the user may, by clicking on an appropriate icon, input different keywords 44 that are particular to the name being checked. For example, these could be trademarks wares or services or terms that have been advertised and have become associated with a particular site or descriptions of the products or services offered. Note that variants of a similar name, such as starbel(l)y and star belli(e) in FIG. 4 for example, can be grouped together one directly below the other. Although FIG. 4 shows that only two groups of names have been input into the GUI text pad input screen, it should be expressly understood that any number of groups of names can be input by the user. The user can also enter the name of the entity (such as the owner, for example) for whom the search is being performed via domain or trademark filters 26 , 28 . Those filters are accessible by clicking the tabs 45 and 43 respectively. This will enable the user to identify a given trademark or domain name as being owned or affiliated with the owner for which the search is being conducted.
[0059] Once the proper data has been input into the search list, the user then generates a search report by clicking on a search button (not shown) thereby allowing the Central manager module 34 to formulate the query request. In doing so, the central manager module 34 will expand the list of names to include all the spelling variations defined by the shorthand and the wildcards, thus generating a plurality of search inquiries each corresponding to spelling variation. The search inquires are then sent by the Interface module 34 through the Internet 22 to one or more of the databases 14 - 20 that contain registered trademark information and registered domain name information. Upon reception of these results through the Internet interface 34 , the data is processed by the central manager and placed into a typopiracy GUI such as that depicted in FIG. 5.
[0060] [0060]FIG. 5, more specifically, shows a GUI having a main table 50 containing the expanded list of names 52 for each group that was specified in relation with FIG. 4 as well as any pertinent ownership information for all related registered domain names and registered trademarks. Moreover, each cell of the main table 50 will indicate whether or not the trademark or domain is “taken” or “free”. The cells which are marked as taken will further display either a check mark 54 or an “x” 56 . The check mark 54 indicates that the name is owned by the owner; ownership having been defined by entries into the domain and trademark filters 26 , 28 as defined previously. Additional pertinent information returned by the database in response to the query, is status information on the various sites. The status information is in the form of various icons, is also contained within the relevant cell. More specifically, main table 50 in FIG. 5 also displays the operational status of the site under the registered domain name. In the example shown, one cell contains an icon, such as a money bag 58 which implies that the Internet domain name has been registered and is for sale. Another icon contains a construction sign 60 implying that that specific Internet site is under construction. A key 62 , on the other hand, indicates that the associated site contains one or more of the keywords that were specified by the user initially. A darkened cell 64 reveals that the site is parked while a line 66 indicates that the site has meta tags in common with the owner's site. Although specific icons are described above, it should be expressly understood that any icon, symbol, and the like can be used without departing from the spirit of the invention.
[0061] The user can also, by clicking on a desired cell, generate more detailed information (i.e, registrant, contacts, etc.) on a particular domain, as shown by the GUI of FIG. 6. This is particularly useful in cases where the owner owns, or is affiliated with, other domains that were not registered under his or her name. In such cases, the user can send these domains into the domain filter 45 and, as a result, the corresponding cells in the main table 50 will thereafter be marked accordingly with a check mark 54 . The user can also view more detailed information pertaining to a given trademark by clicking on the appropriate cell. Moreover, the user can also generate a list containing other similar trademarks (not shown). once again, the program allows for situations in which the owner owns, or is affiliated with, other trademarks that were not registered under his or her name. In such cases, the user simply sends these trademarks into the trademark filter 48 and, as a result, the corresponding cells in the main table 50 will thereafter be marked with a check mark 54 .
[0062] At any time during the course of this stage, the user can generate a conflict analysis or a bad faith analysis by clicking on the appropriate buttons. Both analyses are described below with reference to subsequent figures.
[0063] Conflict Analysis
[0064] [0064]FIG. 7 illustrates the GUI of a conflict analysis. As shown, a portion of the screen contains a list of the names 72 being analyzed; the latter being the same which were specified with respect to FIG. 4 and which were used during the course of the typopiracy search. The user need only click the specific name for which the analysis is required. Another portion of the screen, designated by the reference numeral 54 , enumerates the five different types of analyses that can be done. These five types, which were described in greater detail in the background, include: owner trademark versus other trademarks, owner trademark versus other domain names, owner domain name versus other trademarks, owner domain name versus other domain names, and owner product name versus other trademarks or domain names. The third and final portion of the screen contains the actual results of the conflict analysis 76 .
[0065] Bad Faith
[0066] [0066]FIG. 8 shows the GUI of the menu that allows the user to perform a bad faith analysis. As shown, as in the main table 50 , if a domain or trademark is recognized as being owned or affiliated with the owner, it may be added to the domain filter 45 or trademark filter 43 respectively. Alternatively, the user may instruct the BOTS to search for all domains registered to a specific registrant by highlighting the cell 82 associated with that same registrant and clicking on the appropriate button 84 . As a result, the bad faith module, described hereinafter is invoked.
[0067] [0067]FIG. 9 shows the GUI of the bad faith module. As shown, the name of the registrant being investigated, as specified in connection with FIG. 8, is shown on a portion of the screen 92 . An adjacent portion of the screen 94 shows all the domains registered by the registrant under investigation. Thus, the user can visually assess the specified registrant's domain name registering strategy.
[0068] Cybersquatting
[0069] In order to conduct a cybersquattirig search, the user clicks on the appropriate button and a GUI such as that shown in FIG. 10 is obtained. By clicking on an appropriate menu, the user can access a text entry box (not shown) where the name or names on which searches are to be conducted can be entered. As described in relation with the typopiracy module, the user is not required to input specific or precise names since the program allows for variations due to spelling as well as variations due to prefixes and suffixes by respectively allowing the use of shorthand and wildcards. Moreover, the user can input any number of names as well as associated keywords for each. Each group in the text box is then represented by a name in a group list 102 . At this point, the user specifies a given group by clicking on it and thereby placing a check mark adjacent to it. A regular search or a search including keywords/meta tag information can then be conducted by clicking on the appropriate icons. The results are tabulated and displayed on an adjacent portion of the screen. More specifically, FIG. 10 shows the domain names 104 returned by the BOTS as well as their respective registrants 106 . The status of each site 108 (i.e., parked, for sale, etc.) is also displayed via the use of icons such as those described previously.
[0070] Once the results of the analyses detailed hereinabove are obtained, they can be forwarded to a report module.
[0071] Although various embodiments have been illustrated, this was for the purpose of describing, but not limiting, the invention. Various modifications will become apparent to those skilled in the art and are within the scope of this invention, which is defined more particularly by the attached claims. | A method for performing domain name information and trademark information analysis. The method includes prompting a user to enter a name on which a search is to be conducted and then formulating a query request directed to remote databases containing domain name information and trademark information. The response received to the query request is processed and displayed to the user. The method allows detection of questionable Internet practices such as typopiracy, cybersquatting and bad faith. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to apparatus for heating and sealing glass, and more particularly to a burner manifold with dual gas and temperature controls for use in sealing a wafer in a CRT (cathode ray tube) neck.
A CRT comprises three major sections, namely a panel, a funnel, and a neck. The neck comprises at its end remote from the panel an electron gun that is mounted on a wafer with lead wires for the gun electrodes projecting through the wafer. Surrounding the lead wires at the wafer are round portions of glass called "fillets" to provide a better seal around the lead wires.
During manufacture, the CRT is held in the vertical panel-up position, and the wafer with the gun mounted thereon is upwardly inserted into the neck. Heat from burners is then applied to the outside of the neck proximate the wafer, i.e., at the "seal plane", and the CRT and the wafer are rotated about their vertical central axes so that the neck softens, thins and then seals to the wafer. Also excess neck material that is lower than the wafer (cullet) is cut off and therefore falls away from the neck. However, the optimum temperature for softening is not the same as that for cutting. Thus a compromise temperature of about 950° C. is used.
However, if for any reason the axis of the gun does not match the axis of the neck, or if the plane of the burners does not substantially match that of the wafer, then an incomplete cullet cut-off resulting in excess glass material called a "hanger" can be produced. The normal response of a production worker is to increase the temperature of the burners to achieve a better cut-off. Unfortunately, this can result in a "hot seal", where a portion of the inside of the neck glass melts and forms a sharp angle called a "reentrancy" with one or more of the fillets. Such reentrancies are stress concentration points that can result in a break in the wafer (called a "cracked stem" or "cracked seal"). Other problems with a hot seal include creating a burn hole, so that evacuation of air from the CRT is not possible during a subsequent pump-down operation, and creating an excessively thin region of the neck glass, which region can be easily broken.
The present invention overcomes the above problems.
SUMMARY OF THE INVENTION
Apparatus for sealing a wafer in the neck of a cathode ray tube and for cutting off excess neck material comprises a plurality of burners divided into two groups. The first group has a higher temperature than the second group. Also, the first group is aimed slightly below said wafer, while the second group is aimed at said wafer. Thus, the first group of burners cuts off excess neck material, while the second group seals the neck to the wafer.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view showing apparatus in accordance with the invention; and
FIG. 2 is a top view of the apparatus, partly in cross-section, along the line 2--2 of FIG. 1.
DETAILED DESCRIPTION
FIG. 1 shows a CRT assembly 10 comprising a panel 12, a funnel 14, and a neck 16, all made of glass. As known in the art, the CRT assembly 10 is supported by a carrousel (not shown) that rotates the CRT assembly 10 among successive mount sealing stations, one of which, the wafer sealing and cullet cut-off station, is shown in FIGS. 1 and 2. In the neck 16 is disposed an electron gun 18 mounted on a wafer 20 by a plurality of leads 22 that project through the wafer 20. In the center of the wafer 20 is a tubulation 24 that is supported by a spindle (not shown), as is conventional.
FIG. 2 best shows a burner in accordance with the invention. A manifold 26 has a pair of partitions 28 and 30 so that it is divided into a central chamber 32, and a pair of outside chambers 34 and 36. Communicating with the central chamber 32 are a pair of inner burners 38 and 40; and communicating with the outside chambers 34 and 36 are outer burners 42 and 44, respectively. The inner burners 38 and 40 preferably are aimed so that their flames perpendicularly impact the neck 16 at the sealing plane, for best sealing action. On the other hand, the outer burners 42 and 44 preferably are aimed so that their flames tangentially impact the neck 16 slightly below the sealing plane, for best cutting action. The burners are arrayed in an arc, which has an angle of 60 degrees, with a range of from 60 to 90 degrees being typical.
Fuel, such as natural gas, is received by a pipe 46 and provided to adjustable valves 48 and 50 and then to mixers 52 and 54. Oxygen is received by a pipe 56 and provided to adjustable valves 58 and 60 and then to the mixers 52 and 54. The mixers 52 and 54 mix the fuel and oxygen to form combustible gas mixtures. The combustible gas mixture from the mixer 52 is provided by pipes 62 and 64 to the outside chambers 34 and 36, respectively. Thus the burners 42 and 44 comprise a first group of burners providing the same temperature since they have the same gas mixture applied thereto. The combustible gas mixture from the mixer 54 is applied by a pipe 66 to the central chamber 32. Thus the inner burners 38 and 40 comprise a second group of burners. A stand 68 (shown only in FIG. 1) is used to support the pipe 66 and the manifold 26 with its associated burners 38, 40, 42 and 44. The height of the stand 68 is selected to assure that the flames from the burners 38 and 40 are essentially at the sealing plane.
In operation, the burners 38, 40, 42, and 44 are ignited. The valves 48 and 58 are adjusted so that the first group of burners 42 and 44 provide an optimum temperature (about 975° C. at the neck 16) for cutting. The valves 50 and 60 are adjusted so that the second group of burners 38 and 40 provide an optimum temperature (about 925° C. at the neck) for sealing. These temperatures are optimum for type EG-20 glass manufactured by Owens-Illinois Co. and type 0137 glass manufactured by Corning Glass Works and for a wall thickness of the neck 16 of 0.090 inches (2.286 mm). In general, greater oxygen sharpens the flame for a better cutting action, while less oxygen broadens the flame for better sealing. The nozzle shape of the burners 38, 40, 42, and 44 can also be selected to provide a desired flame shape. The CRT assembly 10 is rotated by the carrousel (not shown) into the wafer sealing and cullet cut-off station as shown by an arrow 70 in FIG. 2. About 19 seconds are available at each station. Means (not shown) are provided on the carrousel to rotate the CRT assembly 10 about its central vertical axis as shown by an arrow 72. The spindle (not shown) holding the tubulation 24 and hence the wafer 20 is also rotating at the same rate as the CRT assembly 10, which is about nine rotations per station. As the CRT assembly 10 and the wafer 20 rotate, sealing of the neck 16 to the wafer is done by the second group of burners 38 and 40, while cut-off of the cullet 74 is done by the first group of burners 42 and 44. Since each group has the optimum temperature for the operation it performs, no hangers result, and therefore the operator will not increase the temperature of any of the burners. This eliminates hot seals and the problems resulting therefrom. The CRT 10 is then rotated by the carrousel to the next station. | An apparatus for sealing a wafer in the neck of a CRT has two groups of burners, one group provides the optimum temperature for sealing, the other group provides the optimum temperature for cutting off the cullet. The burners are arranged in an arc with the outer burners performing the cutting off operation and the inner burners performing the sealing operation. | 2 |
TECHNICAL FIELD
[0001] This invention relates to thermoplastic constructs and more particularly, to the combined use of first and second fatty acid amides as melt additives to improve the softness of extruded thermoplastic constructs, such constructs including continuous filaments, microfilaments, staple fibers and films.
BACKGROUND OF THE INVENTION
[0002] Thermoplastics are becoming an evermore-popular material to be used in the fabrication of disposable and semi-durable goods. The ability of thermoplastics to be formed into specialized fabrics, both woven and nonwoven, and films designed to meet specific performance requirements has resulted in such thermoplastic materials being incorporated into numerous medical, hygiene, and industrial applications. Research and development are ongoing to modify these thermoplastic materials to further improve or otherwise alter the resulting performance of the thermoplastic materials in the fabricated articles.
[0003] Particular focus of this research and development has been to the addition of additives to a thermoplastic polymer base, to thus tailor the performance of the thermoplastic resin. Advances in the modification of thermoplastic polymer performance are evident in exemplary performance additive patents directed to changes in hydrophobicity, hydrophilicity, anti-microbial activity, barrier properties, and retention or dissipation of static charge.
[0004] While such additives have successfully modified the performance of the thermoplastic polymer, deleterious effects on the softness qualities of a resulting article are expected. The softness of an article, measured in terms of both tactile and ductile performance, is a critical aspect of the user-acceptance of such articles. A number of patents address specifically the improvement of softness in thermoplastic constructs; however, the associated chemistries are such that they are incompatible with the performance additives.
[0005] An unmet need remains for a thermoplastic additive that improves the softness of the resulting article, and yet is compatible with performance additives. Due to the criticality of perceived softness in end-use articles, there is also a need for a softness additive that can be favorably compounded with other softness improvement additives, to render thermoplastic constructs of further improved softness.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to the combined use of first and second fatty acid amides to improve the softness of a thermoplastic polymer construct. A combination of fatty acid amides is provided in the blend ratio of about 10 to 90 percent by weight of a first fatty acid amide and 90 to 10 percent by weight of a second fatty acid amide. The first and second fatty acid amides are compounded into a thermoplastic polymer carrier resin and, preferentially, produced as concentrate pellets containing 0.5 to 75 percent by weight total fatty acid amide loading. The concentrate pellets are introduced into a thermoplastic polymer base, to form a thermoplastic resin, at a letdown level in the range of about 1 to 15 percent, with the range of 2 to 10 percent being preferred, and the range of 3 to 6 percent being most preferred.
[0007] A fatty acid amide containing thermoplastic resin can then be extruded as multiple and continuous filaments or as a film or film layer. The continuous filaments can be directly integrated into a nonwoven fabric or included as a layer of a nonwoven composite or laminate fabric. In the alternative, the continuous filaments may be bundled and incorporated into a yarn, which in turn, can be used in part or whole as the yarns of a woven or knitted textile fabric. Fatty acid amide films can be cast as a single sheet product or extruded onto a carrier substrate, such as another film, a textile fabric, or a nonwoven fabric.
[0008] The extruded multiple and continuous filaments can be optionally imparted with a selected level of crimp, then cut into fibers of finite staple length. These thermoplastic resin staple fibers can then be subsequently used to form textile yarns or carded and integrated into nonwoven fabrics by appropriate means, as exemplified by thermobonding, adhesive bonding, and hydroentanglement technologies.
[0009] In addition to the first and second fatty acid amides, additional performance additives can be admixed into the thermoplastic resin. Such performance additives include those directed to modifying the performance of the thermoplastic polymer base. Those that modify the thermoplastic polymer base in terms of hydrophobicity, hydrophilicity, anti-microbial activity, barrier properties, and static charge retention or dissipation exemplify suitable performance additives.
[0010] It is within the purview of the present invention that first and second fatty acid amides can be compounded with other softness improvement additives to obtain yet further softness improvement of the thermoplastic resin construct. Suitable softness improvement additives include inert organic materials such as insoluble carbonate salts and inorganic agents such as silicones and siloxanes. Oleic compounds typically utilized in the preparation of cosmetics would also be of consideration.
[0011] It is also within the purview of the present invention that the manufacture of homogenous or composite fabrics embodying the principles of the present invention includes the use of a blend of fibers and/or filaments having different composition. Differing thermoplastic polymers can be compounded with the same or different fatty acid amides, and with the same or different performance or softness improvement additives. Further, fatty acid amide fibers and/or filaments may be blended with fibers and/or filaments that have not been modified by the compounding of fatty acid amides. Unmodified fibers and/or filaments are selected from natural or synthetic composition, of homogeneous or mixed fiber length. Suitable natural fibers include, but are not limited to, cotton, wood pulp and viscose rayon. Synthetic fibers, which may be blended in whole or part, include thermoplastic and thermoset polymers. Thermoplastic polymers suitable for blending with fatty acid amide thermoplastic resins include polyolefins, polyamides and polyesters. The thermoplastic polymers may be further selected from homopolymers; copolymers, conjugates and other derivatives including those thermoplastic polymers having incorporated melt additives or surface-active agents.
[0012] Multi-component fibers and/or filaments can also be practiced whereby a first thermoplastic polymer composition containing two fatty acid amides is juxtaposed in relationship to a second thermoplastic polymer composition; the second thermoplastic polymer composition being a different thermoplastic polymer than the first thermoplastic polymer, but with the same or lower levels of fatty acid amide softness additives. Multi-component fibers and/or filaments can also include the same first and second thermoplastic polymer compositions, with one or more of the fatty acid amides additives used differing between the two compositions. Additionally, multi-component fibers and/or filaments can be practiced whereby the first thermoplastic polymer contains two fatty acid amides and the second thermoplastic polymer contains either a lower level or no fatty acid amides. The profile of the fiber or filament and the number of thermoplastic polymer compositions juxtaposed is not a limitation to the applicability of the present invention.
[0013] Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.
DETAILED DESCRIPTION
[0014] While the present invention is susceptible of embodiment in various forms, hereinafter is described a presently preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
[0015] The softness of thermoplastic constructs, such as continuous filaments, staple fibers, and film, can be advantageous improved by the combined incorporation of a first and second fatty acid amide. Amides are organic chemicals with a —CONH 2 group. These chemical compounds are recognized as amides or acid amides due to their derivation from a carboxylic acid. Carboxylic acids arise in various molecular forms and also constitute for the make up of fatty acids.
[0016] Fatty acid amides useful in terms of the present invention, include those of the following general primary amine description:
[0017] wherein
[0018] X=the range of 6 to 26 and
[0019] Y=the range of 13 to 53
[0020] The carbon chain of the fatty acid can be of either an alkane, alkene, or alkyne structure, dependent upon the degree of saturation, with a corresponding modification in the value, y. Also, the carbon chain of the fatty acid can exhibit moderate alkyl substitution and bifurcation while maintaining softness improving characteristics.
[0021] In addition to the first and second fatty acid amides, additional performance additives can be admixed into the thermoplastic resin. Such performance additives include those directed to modifying the performance of the thermoplastic polymer base. Hydrophobic modification includes the incorporation of hydrophobic agents such as fluorocarbons taught in patent number U.S. Pat. No. 5,178,931, hereby incorporated by reference. Suitable hydrophilic agents include the oleyl ethers included in U.S. Pat. No. 6,239,047 and the use of stearic acids in U.S. Pat. No. 5,969,026, both of which are hereby incorporated by reference. Representative chemistries with anti-microbial activity include the use of quaternary ammonium salts, as is well covered by the combination of patent numbers U.S. Pat. Nos. 5,300,167, 5,569,732, and 5,854,147, all herein incorporated by reference. U.S. Pat. No. 5,645,627, herein incorporated by reference, teaches static charge retention by use of perfluoroalcohols. U.S. Pat. No. 5,814,688, herein incorporated by reference, teaches suitable static charge dissipation based chemistries.
[0022] It is also within the purview of the present invention that first and second fatty acid amide can be compounded with other softness improvement additives to obtain yet further softness improvement of the thermoplastic resin construct. Suitable softness improvement additives include inert organic materials such as insoluble carbonate salts and inorganic agents such as silicones and siloxanes, and metal oxides, specifically including titanium dioxide. Oleic compounds typically utilized in the preparation of cosmetics would also be of immediate consideration. It is also within the purview of the present invention to include suitable colorants and/or opacifiers in the melt blend.
[0023] Thermoplastic polymers suitable for compounding in accordance with the present invention include polyolefins, polyamides and polyesters. The thermoplastics may be further selected from homopolymers; copolymers, conjugates and other derivatives including those thermoplastic polymers having incorporated melt additives or surface-active agents.
[0024] Technologies capable of employing the fatty acid amide thermoplastic resin of the present invention include those which form continuous filament nonwoven fabrics, staple fiber nonwoven fabrics, continuous filament or staple fiber woven textiles, and films.
[0025] In general, continuous filament nonwoven fabric formation involves the practice of the spunbond process. A spunbond process involves supplying a molten polymer, which is then extruded under pressure through a large number of orifices in a plate known as a spinneret or die. The resulting continuous filaments are quenched and drawn by any of a number of methods, such as slot draw systems, attenuator guns, or Godet rolls. The continuous filaments are collected as a loose web upon a moving foraminous surface, such as a wire mesh conveyor belt. When more than one spinneret is used in line for the purpose of forming a multi-layered fabric, the subsequent webs are collected upon the uppermost surface of the previously formed web. The web is then at least temporarily consolidated, usually by means involving heat and pressure, such as by thermal point bonding. Using this bonding means, the web or layers of webs are passed between two hot metal rolls, one of which has an embossed pattern to impart and achieve the desired degree of point bonding, usually on the order of 10 to 40 percent of the overall surface area being so bonded.
[0026] A related means to the spunbond process for forming a layer of a nonwoven fabric is the melt blown process. Again, a molten polymer is extruded under pressure through orifices in a spinneret or die. High velocity air impinges upon and entrains the filaments as they exit the die. The energy of this step is such that the formed filaments are greatly reduced in diameter and are fractured so that microfibers of finite length are produced. This differs from the spunbond process whereby the continuity of the filaments is preserved. The process to form either a single layer or a multiple-layer fabric is continuous, that is, the process steps are uninterrupted from extrusion of the filaments to form the first layer until the bonded web is wound into a roll. Methods for producing these types of fabrics are described in U.S. Pat. No. 4,043,203, incorporated herein by reference
[0027] Currently, many nonwoven manufacturing lines include at least two spunbond stations and optionally one or more meltblown stations in between. This enables the continuous production of a composite fabric consisting of discrete spunbond and meltblown layers. These fabrics are commonly called SMS, referring to a spunbond-meltblown-spunbond arrangement of layers. Thermal point bonding, as previously described, is typically used to consolidate such webs.
[0028] Staple fibers used to form nonwoven fabrics begin in a bundled form as a bale of compressed fibers. In order to decompress the fibers, and render the fibers suitable for integration into a nonwoven fabric, the bale is bulk-fed into a number of fiber openers, such as a garnet, then into a card. The card further frees the fibers by the use of co-rotational and counter-rotational wire combs, then depositing the fibers into a lofty batt. The lofty batt of staple fibers can then optionally be subjected to fiber reorientation, such as by air-randomization and/or cross-lapping, depending upon the ultimate tensile properties of the resulting nonwoven fabric. The fibrous batt is integrated into a nonwoven fabric by application of suitable bonding means, including, but not limited to, use of adhesive binders, thermobonding by calender or through-air oven, and hydroentanglement.
[0029] The production of conventional textile fabrics is known to be a complex, multi-step process. The production of staple fiber yarns involves the carding of the fibers to provide feedstock for a roving machine, which twists the bundled fibers into a roving yarn. Alternately, continuous filaments are formed into bundle known as a tow, the tow then serving as a component of the roving yarn. Spinning machines blend multiple roving yarns into yarns that are suitable for the weaving of cloth. Certain of the weaving yarns are transferred to a warp beam, which, in turn, contains the machine direction yarns, which will then feed into a loom. Other of the weaving yarns supply the weft or fill yarns which are the cross direction threads in a sheet of cloth. Currently, commercial high speed looms operate at a speed of 1000-1500 picks per minute, whereby a pick is a single yarn. The weaving process produces the final fabric at manufacturing speeds of 1260 inches to 1980 inches per minute.
[0030] The formation of finite thickness films from thermoplastic polymers is a well-known practice. Thermoplastic polymer films can be formed by either dispersion of a quantity of molten polymer into a mold having the dimensions of the desired end product, known as a cast film, or by continuously forcing the molten polymer through a die, known as an extruded film. Extruded thermoplastic polymer films can either be formed such that the film is cooled then wound as a completed product, or dispensed directly onto a substrate material to form a composite material having performance of both the substrate and the film layers. Examples of suitable substrate materials include other films, polymeric or metallic sheet stock and woven or nonwoven fabrics.
[0031] The application of the extruded film directly onto a substrate material imparts the substrate material with enhanced physical properties. It is known in the art that the application of a thermoplastic polymer film having suitable flexibility and porosity onto a nonwoven fabric results in a composite material having significant barrier properties and is suitable for disposable protective garment manufacture.
[0032] Extruded films utilizing the composition of the present invention can be formed in accordance with the following representative direct extrusion film process. Blending and dosing storage comprising at least two hopper loaders, one for thermoplastic polymer chip and one for pelletized fatty acid amide in thermoplastic carrier resin, feed into two variable speed augers. The variable speed augers transfer predetermined amounts of polymer chip and additive pellet into a mixing hopper. The mixing hopper contains a mixing propeller to further the homogeneity of the mixture. Basic volumetric systems such as that described are a minimum requirement for accurately blending the fatty acid amide into the thermoplastic polymer. The polymer chip and additive pellet blend feeds into a multi-zone extruder. Upon mixing and extrusion from the multi-zone extruder, the polymer compound is conveyed via heated polymer piping through a screen changer, wherein breaker plates having different screen meshes are employed to retain solid or semi-molten polymer chips and other macroscopic debris. The mixed polymer is then fed into a melt pump, and then to a combining block. The combining block allows for multiple film layers to be extruded, the film layers being of either the same composition or fed from different systems as described above. The combining block is connected to an extrusion die, which is positioned in an overhead orientation such that molten film extrusion is deposited at a nip between a nip roll and a cast roll.
[0033] When a substrate material is to receive a film layer extrusion, a substrate material source is provided in roll form to a tension-controlled unwinder. The base layer is unwound and moves over the nip roll. The molten film extrusion from the extrusion die is deposited onto the substrate material at the nip point between the nip roll and the cast roll. The newly formed base layer and film composite is then removed from the cast roll by a stripper roll and wound onto a new roll.
[0034] Breathable barrier films can be formed utilizing the improved softness imparted by the compounding of the fatty acid amides. Monolithic films, as taught in patent number U.S. Pat. No. 6,191,211, and microporous films, as taught in patent number U.S. Pat. No. 6,264,864, both patents herein incorporated by reference, represent the mechanisms of forming such breathable barrier films.
[0035] Reticulated films, such as those of patent numbers U.S. Pat. Nos. 4,381,326 and 4,329,309, are representative of macroporous films. Such macroporous films, which are typically employed as the topsheet or facing layer of a disposable feminine hygiene product, come in direct contact with the body and benefit significantly from improved softness as embodied by the present invention.
[0036] Utilizing the above discussed thermoplastic construct technologies, combinations of different thermoplastic constructs can be practiced to yield composite materials of improved softness performance. One or more thermoplastic constructs can incorporate the inclusion of two fatty acid amides, then be combined with one or more thermoplastic constructs which utilize an alternate formulation of two fatty acid amides, or includes reduced levels of fatty acid amide, or contains no fatty acid amide in the thermoplastic polymer composition.
[0037] Manufacture of homogenous or composite fabrics embodying the principles of the present invention includes the use of a blend of fibers and/or filaments having different composition. Differing thermoplastic polymers can be compounded with the same or different fatty acid amides, and with the same or different performance or softness improvement additives. Further, fatty acid amide fibers and/or filaments may be blended with fibers and/or filaments that have not been modified by the compounding of fatty acid amides. Unmodified fibers and/or filaments are selected from natural or synthetic composition, of homogeneous or mixed fiber length. Suitable natural fibers include, but are not limited to, cotton, wood pulp and viscose rayon. Synthetic fibers, which may be blended in whole or part, include thermoplastic and thermoset polymers. Thermoplastic polymers suitable for blending with fatty acid amide thermoplastic resins include polyolefins, polyamides and polyesters. The thermoplastic polymers may be further selected from homopolymers; copolymers, conjugates and other derivatives including those thermoplastic polymers having incorporated melt additives or surface-active agents. Staple lengths are selected in the range of 0.25 inch to 8 inches, the range of 1 to 3 inches being preferred and the fiber denier selected in the range of 1 to 15, the range of 2 to 6 denier being preferred for general applications. The profile of the fiber is not a limitation to the applicability of the present invention.
[0038] Fabrics made of the aforementioned polymer compositions, have a wide variety of end use applications, including hygiene, medical and industrial articles. Personal hygiene articles, which benefit from improved softness, include the construction of liners and the external barrier layers. Liners for sanitary articles, such as disposable diapers and feminine hygiene product top-sheets or facing layers, come in direct contact with the wearer of the article, and thus improved softness, in particular in terms of tactile qualities, results in improved comfort. External barrier layers of hygiene articles such as disposable diapers and incontinence protection gain improved flexibility and conformance to body contours as a result of increased softness as measured by changes in ductile qualities. Medical and Industrial protective articles, such as face masks, surgical drapes and operating gowns, as well as, clean-room garments, once again, benefit from the improved softness and thus improving the wearers comfort when such articles are worn for protracted periods of time. Cuffs construction, as is respectively practiced in the fabrication of hygiene, medical, and industrial articles, relies upon the intimate and prolonged contact with the users skin. Softness improvement in cuffs utilizing the present invention would enable such articles to maintain improved fit and function for longer durations.
[0039] From the foregoing, it will be observed that numerous modifications and variations can be affected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims. | The present invention is directed to the combined use of first and second fatty acid amides to improve the softness of a thermoplastic polymer construct. A combination of fatty acid amides is provided in the blend ratio of about 10 to 90 percent by weight of a first fatty acid amide and 90 to 10 percent by weight of a second fatty acid amide. The first and second fatty acid amides are compounded into a thermoplastic polymer carrier resin and, preferentially, produced as concentrate pellets containing 0.5 to 75 percent by weight total fatty acid amide loading. The concentrate pellets are introduced into a thermoplastic polymer base, to form a thermoplastic resin, at a letdown level in the range of about 1 to 15 percent, with the range of 2 to 10 percent being preferred, and the range of 3 to 6 percent being most preferred. | 3 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to building construction and reinforcement, and specifically to a continuity system that resists tension from wind uplift forces or overturning forces from wind or seismic events while compensating for the downward settling of buildings caused by shrinkage of wooden members. Most specifically, the present invention relates to a ratcheting take-up device that reduces slack due to wood shrinkage and building settling in a holdown system of continuous rods, eases installation and compensates for imperfectly aligned rods.
[0002] A continuity system is a secondary support system that ties walls or other building elements together and resists lateral overturning forces or uplift forces from events such as earthquakes or strong winds. Earthquake and wind forces produce overturning and uplift loads in the building, which load the building elements in overturning or uplift with respect to the building foundation. A continuity system resists such movements of the building elements. A continuity system generally comprises a plurality of interconnected vertically-oriented elements, typically metal rods and bearing plates, or holdowns, that provide a discrete structural mechanism or load path framework for the transfer of loads through the building from the structural elements that are intended to resist such forces, such as roof or floor diaphragms and shearwalls, to the continuity system, and then to the foundation. For example, the presence of a continuity system enables wall panels to resist overturning and/or moments that might damage or destroy the wall.
[0003] A known continuity system is described in U.S. Pat. No. 4,875,314 (“the '314 patent”), the entire disclosure of which is hereby incorporated herein by reference. The '314 patent describes a system in which at least one tie rod is connected to the foundation through a simple threaded coupler and a foundation anchor. Although the tie rod system can be used in a single-story structure, it is particularly suited to multistory structures, as illustrated in the '314 patent. In a multistory structure, a series of anchor elements is used to couple multiple tie rods in a line from the foundation to the top plate of the top story of the structure. The anchor elements of the '314 patent, in addition to coupling tie rods together, are used to secure the tie rods at each level of the structure to eliminate initial slack in the system. The principal shortcoming of the system of the '314 patent is the lack of a means of compensating for slack that builds up in the system as the wood structural members shrink over time. As slack builds up in the system, the system's capacity to resist uplift is correspondingly reduced.
[0004] The prior art includes a number of technical solutions to the problem of increasing slack in continuity systems. Simpson Strong-Tie Company's Anchor Tiedown System uses the TUD and ATUD take-up devices, as well as the CTUD coupling take-up device. The CTUD coupling take-up device is the subject of U.S. Pat. No. 7,905,066, granted to Steven E. Pryor et al. All three devices are driven by a torsion spring. The TUD and ATUD are slipped over the tie rod between a horizontally disposed member and a nut threaded onto the tie rod, and they expand to fill the space as it expands enlarges. The CTUD threads onto and couples the vertically-aligned ends of two tie rods, drawing the two together to maintain tight connections between the wood and steel elements as the wood structural members shrink over time.
[0005] Similar continuity systems with ratcheting take-up devices are described in U.S. Pat. No. 6,007,284 the entire disclosure of which is hereby incorporated herein by reference, and U.S. Pat. No. 7,744,322, the entire disclosure of which is also hereby incorporated herein by reference. These devices, while similar in both basic form and function to the present invention, lack inventive features of the present invention.
[0006] The ratcheting take-up device of the present invention eases installation of continuity systems, compensates for tie rods that are not perfectly perpendicular to the top and bottom plates, and takes up slack in the continuity system after installation.
SUMMARY OF THE INVENTION
[0007] The take-up device of the present invention has a plurality of insert segments with concavities that form an inner bore. The insert segments are contained within a housing that has an outer bore. The lower portion of the outer bore in the housing narrows. The lower portions of the insert segments and the lower portion of outer bore contained by the housing have frusto-spherical bearing surfaces. The insert segments are formed and arranged so that they grasp and hold a tie rod received in the housing when a wind uplift or a shear wall overturning force is applied to the wall of which the take-up device is a part. When a wind uplift or a shear wall overturning force is applied to the wall, the tie rod is placed in tension from an anchoring, reactive force pulling on the tension rod from below the housing while the structural member that is part of the wall to which the take-up device is attached pushes upwardly on the housing of the take-up device. The tie rod, the insert segments and the housing are formed such that when the tie rod moves downwardly with respect to the housing, the insert segments will be pulled downwardly in the housing as well. The tension on the tie rod combined with the narrowing in the lower portion of the outer bore of the housing causes a constriction of the insert segments about the tie rod forcing them to grasp and hold the tie rod, preventing any further downward movement of the tie rod with respect to the housing and thus to the building component to which the housing is attached.
[0008] An important advantage of the take-up device of the present invention is that its frusto-spherical bearing surfaces allow it to anchor imperfectly aligned tie rods by swinging about a central pivot on the vertical axis of the device in any direction without a reduction in the bearing surfaces or the strength of the anchorage. The lower portions of the insert segments collectively have the geometry of a spherical segment—a spherical cap with the top truncated, or a spherical frustum. The first frusto-spherical bearing surface is the outward-facing, lower surfaces of the insert segments taken together. The second frusto-spherical bearing surface is the inward-facing lower portion of the outer bore of the housing. The insert segments are inserted in the outer bore of the housing. The frusto-spherical sections of each, solid in the segments and hollow in the outer bore, are closely matched. Because the lower bearing surfaces of the insert segments are able to rotate or swing to be in contact with a matching surface in the lower portion of the outer bore of the device housing, there is little or no reduction in the net bearing interface when the rod received by the nut segments is out of alignment with the vertical axis of the housing.
[0009] A further advantage of the present invention is that the housing and insert segments are shaped and arranged to allow a tie rod to be quickly inserted through the inner bore formed by the insert segments by pushing the tie rod up through the bore. When a tie rod is first inserted up into the housing, the upward movement of the tie rod forces the insert segments apart from a constricted position—the constriction preferably caused by the downward force of gravity and possibly by a compression member placed above the insert segments, combined with the narrowing in the lower portion of the outer bore of the housing—to the width of the tie rod. The interface between the surfaces of the tie rod and the insert segments creates a ratcheting action as the tie rod is pushed up and the insert segments move up and out laterally, allowing the tie rod to be inserted as far as needed into the housing for installation. When the building shrinks, the relative movement of the tie rod and the housing is similar to movement during installation. The relative upward movement of the rod with respect to the housing pushes the insert segments up and out laterally, and gravity and any relative downward movement of the tension rod as well as the usual tension that is placed on the rod once it is installed pulls the insert segments downwardly and inwardly in combination with the narrowing of the outer bore of the housing and thus against the rod, holding it with respect to the housing.
[0010] A further object of the present invention is to provide insert segments that are made with flat tops and bottom edges and in the preferred embodiment are compressed by a member with a flat surface so that it allows tie rods to be inserted with a minimal risk of jamming the take-up device because the insert segments are held in place by a flat, hard washer above, which interface with flat surfaces at the tops of the insert segments to stabilize them as they expand away from and constrict towards the central vertical axis of the device. Another object of the present invention is to provide the housing with a small ledge which interfaces with the bottom edges of the insert segments to stabilize them as they expand away from and constrict towards the central vertical axis of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of the take-up device of the present invention.
[0012] FIG. 2 is an exploded perspective view of the take-up device of the present invention.
[0013] FIG. 3 a perspective view of a connection made with the take-up device of the present invention, showing the take-up device installed on the top plate of a stud wall.
[0014] FIG. 4 is a perspective view of a connection made with the take-up device of the present invention, showing two take-up devices of the present invention, each installed on a different level of the same structure.
[0015] FIG. 5 is a top plan view of the housing of the take-up device of the present invention.
[0016] FIG. 6 is a cross-sectional elevation view of the housing of the take-up device of the present invention taken along view line 6 - 6 in FIG. 5 .
[0017] FIG. 7 is a top plan view of the upper and lower hard washers of the compression member of the take-up device of the present invention.
[0018] FIG. 8 is a cross-sectional elevation view of the hard washers of the take-up device of the present invention taken along view line 8 - 8 in FIG. 7 .
[0019] FIG. 9 is a top plan view of the soft washer of the take-up device of the present invention.
[0020] FIG. 10 is a cross-sectional elevation view of the soft washer of the take-up device of the present invention taken along view line 10 - 10 in FIG. 9 .
[0021] FIG. 11 is a top plan view of the insert segments of the take-up device of the present invention.
[0022] FIG. 12 is a cross-sectional elevation view of the insert segments of the take-up device of the present invention taken along view line 12 - 12 in FIG. 11 .
[0023] FIG 13 is a top plan view of the take-up device of the present invention.
[0024] FIG. 14 is a cross-sectional elevation view of the take-up device of the present invention taken along view line 14 - 14 in FIG. 13 .
[0025] FIG. 15A is a cutaway elevation view of a connection made with the take-up device of the present invention, showing a threaded rod perfectly centered within and parallel to the inner bore.
[0026] FIG. 15B is a cutaway elevation view of a connection made with the take-up device of the present invention, showing a threaded rod imperfectly centered within and not parallel to the inner bore, with the insert segments rotated to accommodate the angle of the threaded rod.
[0027] FIG. 16 is a cutaway cross-sectional elevation view of the interface between the insert segments and the outer bore of the take-up device housing of the present invention.
[0028] FIG. 17 is a perspective view of an insert segment of the take-up device of the present invention.
[0029] FIG. 18 is a perspective view of an insert segment of the take-up device of the present invention; the insert segment shown in FIG. 18 has smaller inner bore than the similar insert segment shown in FIG. 17 .
[0030] FIG. 19 is a top plan view of the take-up device of the present invention; the take-up device shown in FIG. 19 has a smaller inner bore than the similar take-up device shown in FIG. 13 .
[0031] FIG. 20 is a cross-sectional elevation view of the take-up device of the present invention taken along view line 20 - 20 in FIG. 19 ; the take-up device shown in FIG. 20 has a smaller inner bore than the similar take-up device shown in FIG. 14 .
DETAILED DESCRIPTION
[0032] For clarity and convenience, the take-up device 1 of the current invention is described in a single, most common, orientation (except as noted otherwise) in which a top faces up and a bottom faces down. The take-up device 1 can, nevertheless, be installed in essentially any orientation, so that a top can face down or to the side and a bottom can face up or to the side.
[0033] As best shown in FIGS. 2 and 11 , the take-up device 1 of the present invention preferably has four insert segments 2 arranged sectionally around an inner bore 16 . Greater or lesser numbers of insert segments 2 are possible, but four is preferred. The insert segments 2 are designed to grasp a preferably vertical tie rod or threaded bolt 24 . Preferably, vertical tie rod 24 is a least threaded where it is grasped by insert segments 2 . Vertical tie rod 24 can be wholly threaded, partially threaded, or unthreaded, although if is unthreaded it is preferable to have a grooved surface that can mate with similar grooves on the insert segments 2 for achieving design load values, although alternate methods of the grasping of the insert segments 2 of the tie rod 24 are encompassed within the invention. The insert segments 2 preferably surround the tie rod or threaded bolt 24 , but with gaps between the insert segments 2 . Preferably, each insert segment 2 has a substantially planar top surface 3 .
[0034] The top surface 3 need not be planar, but it is generally advantageous to maximize the area of the top surface 3 because the top surface 3 is where the insert segments 2 are pushed down by compression member 46 which helps to prevent the insert segments 2 from rotating too far out of their upright orientation when the tie rod 24 pushes them upwardly and outwardly during shrinkage of the building or installation of the tie rod 24 , and thus the insert segments 2 are properly positioned to grasp the tie rod 24 as firmly as possible when the tie rod 24 is in tension again. The top surface 3 of each insert segment 2 preferably has a concave inner bore-defining edge 4 that has a first end 5 and a second end 5 . The inner bore-defining edge 4 is preferably an arc 4 . Preferably, a substantially straight first side edge 6 connects the first end 5 of the concave inner bore-defining edge 4 to the first end 8 of a convex outer bore edge 7 . Preferably, a substantially straight second side edge 6 connects the second end 5 of the concave inner bore-defining edge 4 to a second end 8 of the convex outer bore edge 7 . The first and second substantially straight side edges 6 of the top surface 3 are preferably orthogonal to each other. The outer bore edge 7 is preferably a nearly 90-degree arc 7 except where the arc 7 is interrupted by a tab 9 that projects from the convex outer bore edge 7 . Preferably, the tab 9 has a slightly curved outer edge 10 with first and second ends 11 that are connected to the arc 7 by first and second substantially straight side edges 12 , respectively. The tab 9 is preferably formed as an integral part of the insert segment 2 , rather than as a separate part attached to the insert segment 2 .
[0035] In the currently preferred embodiments of the invention optimized to grasp a ⅜″ or ½″ diameter threaded rod, in which there are four insert segments 2 , as shown in FIGS. 11 and 14 , the distance between opposite outer edges 10 of the tabs 9 of opposed segments 2 is preferably 1.375 inches.
[0036] As best shown in FIGS. 12 , 17 and 18 , each insert segment 2 preferably has first and second substantially planar sides 13 perpendicular to the top surface 3 . Preferably, the first substantially planar sides 13 extend downward from the first and second edges 6 of the top surface 3 . The first and second substantially planar sides 13 are preferably orthogonal to each other. Each insert segment 2 preferably has a rough, threaded, concave inner bore-defining surface 14 that extends downward from the concave inner bore-defining edge 4 and connects the first and second substantially planar sides 13 . Preferably, each bore-defining surface 14 is primarily a section of a rough, threaded, right circular cylindrical surface 15 that defines the inner bore 16 . As shown in FIGS. 12 and 18 , each insert segment 2 preferably has an outer bore-interfacing surface 17 that extends downward from the arc 7 of the outer bore edge 7 . In the currently preferred embodiments of the invention the outer bore-interfacing surface 17 and the inner bore 16 preferably has a surface roughness of 125-250 micro-inches (3.2-6.3 μm).
[0037] As best shown in FIGS. 2 and 11 , a portion 103 of the substantially planar top surface 3 of each insert segment 2 preferably extends radially outward away from the inner bore 16 to form the top surface 103 of each tab 9 , bounded by the outer edge 10 and the two sides edges 12 of each tab 9 . Preferably, each tab has a substantially planar outer surface 18 that descends from the outer edge 10 . Each tab 9 preferably has first and second substantially planar side surfaces 19 that descend from the first and second side edges 12 , respectively, of the tab 9 . Preferably, each tab 9 has a substantially planar bottom surface 20 opposite the top surface 103 of the tab 9 . In the currently preferred embodiments of the present invention, each tab 9 is 0.250 inches wide from the first side edge 12 to the second side edge 12 , and each tab 9 is preferably 0.120 inches thick from the top surface 103 to the bottom surface 20 .
[0038] As best shown in FIGS. 2 , 12 , 17 and 18 , preferably the general shape of the lower portion of the outer bore-interfacing surfaces 17 of the insert segments 2 is collectively that of a spherical segment—a spherical cap with the top truncated or a spherical frustum. In the currently preferred embodiments of the present invention a radius of 0.5 inches is preferred. The insert segments 2 generally have the form of an inverted dome with the inverted apex cut off parallel to the base. If there are four insert segments 2 , each is approximately one quarter of the spherical frustum and the spherical frustum is vertically quartered, and the quarters preferably spaced slightly apart. Two segments 2 side-by-side have the general shape of an inverted semi-dome. The outer bore-interfacing surfaces 17 preferably taper from the top surfaces 3 of the insert segments 2 to bottom edges 21 of the insert segments 2 , reducing the cross-section of each insert segment 2 from the top surface 3 to the bottom edge 21 . Preferably, the general shape of the upper portion 104 of the outer bore-interfacing surface 17 of the insert segments 2 is collectively that of a cylinder with tabs 9 splayed circumferentially. The lower portion 105 the outer bore-interfacing surface 17 of the insert segments 2 curves inward. In the currently preferred embodiments of the present invention, the substantially planar bottom surface 20 of each tab 9 joins the tapering outer bore-interfacing surface 17 of its insert segment 2 at a tab juncture 25 that has a radius of 0.020 inches. The insert segments 2 together preferably form an inverted dome with a central vertical through-bore.
[0039] As best shown in FIGS. 12 , 14 and 20 , the rough, preferably threaded, inner bore-defining surface 14 of each insert segment 2 extends from a top end 22 to a bottom end 23 , where the inner bore 16 flares outward with a substantially annular widening taper surface 36 , or chamfer 36 , on each insert segment 2 that meets the bottom edge 21 of each insert segment. These flared, or beveled, bottom portions 36 of the inner bore 16 are where the tie rod or threaded bolt 24 is inserted; the flared portions 36 ease insertion of the tie rod or threaded bolt 24 . Each substantially planar widening taper surface 36 is preferably oriented at 45 degrees to the top surfaces 3 of the insert segments 4 and at 45 degrees to the central axis 100 of the take-up device 1 , with the acceptable range being up to 15 degrees more or less. Preferably, each taper surface 36 is a surface section of a conical frustum. In the currently preferred embodiments of the present invention, the flared bottom portions 36 widen the inner bore 16 to a maximum width of 0.545 inches across. In the currently preferred embodiments of the present invention, the bottom edge 21 is preferably not a true edge, but is instead a very narrow annular surface 21 , a flat base 21 that helps to stabilize the insert segments 2 . As shown in FIG. 16 , in the currently preferred embodiments of the present invention, the bottom edge 21 of each insert segment is preferably 0.0085 inches across parallel to the top surface 3 : the maximum width across the lowest part of the insert segments 2 collectively is 0.562 inches from edge 21 to edge 21 of opposed segments 2 when the insert segments 2 are resting on the ledge 45 of the outer bore 27 ; the height of the insert segments 2 , measured from the top surface 3 to the bottom edge 21 , is preferably 0.539 inches. The height of the insert segments 2 is sufficient to grasp enough of the tie rod or threaded bolt 24 for a secure connection 110 by connecting to multiple turns of the threaded bolt 24 . In the currently preferred embodiments of the present invention, the insert segments 2 are held apart by the tie rod or threaded bolt 24 , so that adjacent sides 13 of the insert segments 2 do not interface but are instead held 0.062 inches apart.
[0040] Currently, the inventors have engineered and developed two preferred sizes of the take-up device 1 of the present invention. The inventors contemplate developing additional sizes for larger sizes of tie rods 24 and will adjust dimensions to maximize the performance of the take-up device with the different tie rods 24 . Currently, the two sizes differ only in the dimension of the right circular cylindrical surfaces 15 that define the inner bore 16 , which in a first embodiment is sized to accept a ⅜-16 UNC threaded rod 24 (best shown in FIG. 20 ) and in a second embodiment is sized to accept a ½-13 UNC threaded rod 24 (best shown in FIG. 14 ). With the preferable spacing of 0.062 inches between the insert segments 2 , the maximum diameter of the rough, threaded, concave inner bore-defining surface 14 (made up of the the right circular cylindrical surfaces 15 ) of the inner bore 16 is 0.342 inches when the threaded rod is ⅜-16 UNC. When the threaded rod 24 is ½-13 UNC, the maximum diameter of the rough, threaded, concave inner bore-defining surface 14 (made up of the the right circular cylindrical surfaces 15 ) of the inner bore 16 is 0.459 inches.
[0041] As best shown in FIGS. 13 , 14 , 19 and 20 , the insert segments 2 fit into an outer bore 27 in a housing 26 that holds the segments 2 in the correct sectional arrangement to form the inner bore 16 . The housing 26 is preferably a seamless, unitary member 26 with a vertical body 28 that is preferably cylindrical and contains the outer bore 27 and a horizontal plate 29 below the vertical body 28 . The horizontal plate 29 has a top face 101 and a bottom face 102 . Preferably, the horizontal plate 29 is shaped generally as an elongated rhombus with two relatively closely spaced corners 30 and two relatively distantly spaced corners 31 . The two relatively closely spaced corners 30 and two relatively distantly spaced corners 31 are preferably rounded. The two closely spaced opposing corners 30 do not extend beyond the cylindrical body 28 and match the curvature of the cylindrical body 28 where the plate 29 and cylindrical body 28 coincide. The two distantly spaced opposing corners 31 are spaced away from the cylindrical body 28 . The plate 29 has a fastener opening 32 between each distantly spaced 31 corner and the cylindrical body 28 . In the currently preferred embodiments of the present invention, each of the fastener openings 32 has a diameter of 0.171 inches. The fastener openings 32 are preferably spaced 1.886 inches apart on center. The center of the outer bore 27 is 0.943 inches from the centers of the fastener openings 32 .
[0042] Also, in the currently preferred embodiments of the present invention, the cylindrical vertical body 28 preferably has an outer diameter of 1.283 inches. The vertical body 28 has a top edge 33 . The outer bore 27 within the vertical body 28 has a diameter at the top edge 33 of 1.123 inches. Therefore, the vertical body 28 has a wall 34 that is preferably 0.16 inches thick at the top edge 33 . The cylindrical vertical body 28 is 1.209 inches in diameter from the middle of the wall 34 across to the middle of wall 34 opposite. The top edge 33 is preferably flat except where it is notched with a number of indentations or slots 35 that match the tabs 9 on the insert segments 2 . Each tab 9 preferably fits in an indentation 35 and preferably extends outside the vertical body 28 , and the interlock prevents the insert segments 2 from rotating around the central axis 100 . The interface between the tabs 9 and the indentations 35 also helps to stabilize the insert segments 2 , helping to keep them level especially when a threaded rod 24 is inserted into the inner bore 16 . Rather than being screwed into the inner bore 16 , the threaded rod 24 is preferably pushed in without rotation and the insert segments 2 react by moving apart and together, ratcheting when the threaded inner bore 16 interfaces with a threaded bolt 24 . The compression member 46 allows the insert segments 2 to move up within the housing 26 , and the upwardly-widening outer bore 27 allows the insert segments 2 to move apart. This allows the threaded bolt 24 to be inserted into the inner bore 16 , and as the threaded bolt 24 and the threaded portion of inner surfaces 14 of the insert segments 2 slide against each other, the segments 2 are moved up and outwardly and down and inwardly repeatedly, the inward motion urged by the compression member 46 and the narrowing outer bore 27 in the housing 2 . The threaded bolt 24 can only be inserted in one direction because when it is pulled down, the downwardly-narrowing outer bore 27 forces the insert segments 2 against the threaded rod 24 so that the threaded bolt 24 and the threaded portion of inner surfaces 14 of the insert segments 2 interlock as if the threaded bolt 24 had been screwed into a conventional solid nut.
[0043] As shown in FIG. 5 , preferably the housing 26 has a lateral horizontal axis 37 that passes through centers of the two fastener openings 32 and the center of the outer bore 27 , which is preferably also the center of the cylindrical body 28 , the housing 26 and the inner bore 16 . Preferably, the housing 26 also has a medial horizontal axis 38 that also passes through the center of the outer bore 27 and is orthogonal to the lateral horizontal axis 37 . The indentations 35 are preferably centered on first and second diagonal horizontal axes 39 that are 45 degrees off of the lateral horizontal axis 37 and the medial horizontal axis 38 . In the currently preferred embodiments of the present invention, each indentation 35 is preferably 0.281 inches wide along the circumference of the top edge 33 of the cylindrical body 28 . Preferably, each indentation 35 is 0.454 inches deep from the top edge 33 of the cylindrical body 28 .
[0044] As best shown in FIGS. 2 , 6 and 16 , in the currently preferred embodiments, the outer bore 27 preferably descends at right angles to the flat surface of the top edge 33 . The outer bore 27 descends 0.045 inches to a groove 40 that runs parallel to the top edge 33 . The groove 40 is 0.062 inches tall and has cross-section that is U-shaped in cross-section, with an internal radius of 0.031 inches. The outer bore 27 preferably descends another 0.324 inches straight down, creating an upper vertical portion 41 that descends a total of 0.431 inches straight down from the top edge 33 ; the groove 40 is within that upper vertical portion 41 . At a depth of 0.431 inches, the outer bore 27 preferably tapers inward at an angle of 65 degrees relative to the bottom face 102 of the horizontal plate 29 , creating a middle inward-angled portion 42 . The middle inward-angled portion 42 transitions to a lower inward-curved portion 43 that preferably has a radius of 0.510 inches in a vertical plane. This closely matches the 0.5-inch radius, also in a vertical plane, of lower portion 105 of the outer bore-interfacing surfaces 17 of the insert segments 2 . The lower inward-curved portion 43 reduces the taper angle from 65 degrees. The middle inward-angled portion 42 and the lower inward-curved portion 43 together reduce the diameter of the outer bore 27 , and their collective depth is preferably 0.419 inches, so that with the upper vertical portion 41 the collective depth is preferably 0.85 inches. Below the lower inward-curved portion 43 the outer bore 27 has a bottom portion 44 that is flared and preferably has a depth of 0.091 inches and that slightly increases the diameter of the outer bore 27 from a minimum of 0.545 inches at the bottom face 102 of the horizontal plate 29 to 0.558 inches. The slight widening of the bottom flared portion 44 eases insertion of the threaded rod 24 . Between the inward-curved portion 43 and the bottom flared portion 44 is a horizontal, or flat, ledge 45 that is 0.0115 inches wide and orthogonal to the central axis 100 of the housing 26 . The diameter of the outer bore 27 is 0.568 inches at the bottom of the lower inward-curved portion 43 and is 0.545 inches at the top of the bottom flared portion 44 . This horizontal ledge 45 helps to keep the insert segments 2 level when a threaded rod 24 is inserted into the ratcheting take-up device 1 to create the basic connection 110 . The preferred total height of the outer bore is 0.941 inches.
[0045] As best shown in FIGS. 7-10 , preferably the insert segments 2 are retained within the outer bore 27 by a compression member 46 . The compression member 46 preferably comprises a lower hard washer 47 , a middle soft washer 48 and an upper hard washer 47 . The middle soft washer 48 is preferably made from a resilient material like rubber that, when compressed, stores energy and expands when compression forces are released. Preferably, the middle soft washer 48 is made from soft quick-recovery super-resilient polyurethane foam, which has a firmness at 25 percent deflection, of 4-8 psi, a tensile strength of 40 psi, a stretch limit of 100 percent, and a density of 15 pounds per cubic foot. The middle soft washer 48 functions like a standard metal compression spring and a spring could be used, but the washer 48 is preferred. In the currently preferred embodiments of the present invention, the middle soft washer 48 preferably a 0.235-inch thick ring with an outer diameter of 1 inch and an inner diameter of 0.567 inches. The inner diameters of the compression member 46 limit how far the insert segments 2 can tilt or rotate. The upper and lower hard washers 47 are preferably made from steel. Preferably, each has an inner edge 50 , an outer edge 51 , an upper surface 52 and a lower surface 53 . Preferably, the inner edge 50 and the outer edge 51 are both generally circular. The inner edge preferably has a pair of inclusions 52 , each with a preferred radius of 0.063 inches that evenly divide the remainder into two arcs 53 with a diameter of 0.562 inches. Preferably, the outer edge 51 has four pairs of inclusions 54 , each with a preferred radius of 0.063 inches. Each pair of inclusions 54 preferably is 90 degrees apart around the circumference of the outer edge 51 . Preferably, between the inclusions 54 of each pair is a small arc 55 that is preferably 0.254 inches wide. These four small arcs 55 preferably each have a diameter of 1.187 inches. Preferably, between each pair of inclusions 54 is a large arc 56 with a diameter of 1.108 inches. The preferred total of eight inclusions 54 in the outer edge 51 bound an inner area with a circumference 57 with a diameter of 1.068 inches. The upper and lower hard washers 47 are preferably 0.047 inches thick. Preferably, the small arcs 55 , which project slightly from the rest of the outer edges 51 of the upper and lower hard washers 47 , and are therefore on slight projections 49 that are inserted in the indentations 35 in the wall 34 of the cylindrical body 28 of the housing 26 of the take-up device 1 . The lower hard washer 47 is stabilized by the interfaces between the small arcs 55 and the indentations 35 . The upper hard washer 47 is rotated so small arcs 55 slide into the groove 40 in the wall 34 of the cylindrical body 28 of the housing 26 of the take-up device 1 . This locks the upper hard washer 47 in place. The upper hard washer 47 holds the middle soft washer 48 and the lower hard washer 47 in place, and this whole compression member 46 holds the insert segments 2 down within the outer bore 27 of the take-up device 1 . When the insert segments 2 push up, the middle soft washer 48 compresses and, because it is resilient, the middle soft washer 48 pushes the insert segments 2 down when the upper hard washer 47 is locked in place. The whole compression member 46 functions as a spring tailored for the best performance in this device 1 and connection 110 . The interface between the outer bore-interfacing surfaces 17 of the insert segments 2 and the inward-angled and inward-curved portions 42 and 43 of the outer bore 27 forces the insert segments 2 together. The insert segments 2 clamp together on the tie rod or threaded bolt 24 . The matching curvatures of the bore-interfacing surfaces 17 of the insert segments 2 and the inward-curved portions 43 of the outer bore 27 allow the insert segments 2 to rotate or swing on a horizontal axis generally orthogonal to, and intersecting with, the tie rod or threaded bolt 24 without diminishing the interface area. This allows the take-up device 1 to compensate for imperfect alignment of the tie rod or threaded bolt 24 without diminishing the strength of the connection 110 . The insert segments 2 can tilt, or rotate, in any direction. Generally, the segments 2 need only rotate a maximum of two degrees from the central axis 100 , but the ability to do this without diminishing the interface with the outer bore 27 and the strength of the connection 110 is substantially advantageous since tie rods or threaded bolts 24 are rarely, if ever, aligned perfectly.
[0046] As shown in FIG. 3 , an anchor bolt 118 is embedded in a concrete foundation 112 . The anchor bolt 118 passes through the horizontal bottom plate 113 of a wall 111 , in this case the mudsill 113 , and it attached to a coupler 117 that bears down on a holdown 116 that is mounted on one of the vertical wall studs 114 . The coupler 117 joins the anchor bolt 118 to an in-line threaded rod 24 that runs parallel to the wall stud 114 and up through the double top plate 115 , where it is secured to the top plate 115 by a take-up device 1 of the present invention that is fastened to the top plate 115 with a bearing plate 120 sandwiched between the bottom face 102 of the take-up device 1 and the top plate 115 .
[0047] As shown in FIG. 4 , take-up devices 1 of the present invention can be placed at every level of a multistory structure. In FIG. 4 , a first take-up device 1 is shown fastened to the bottom plate 113 of an upper floor and a second take-up device 2 is attached to the top plate 115 directly above.
[0048] In its simplest form, the present invention is a take-up device 1 that has a housing 26 and a plurality of insert segments 2 . The housing 26 has an outer bore 27 and the outer bore 27 has a lower inward-curved portion 43 that is frusto-spherical. The insert segments 2 each has an outer bore-interfacing surface 17 that interfaces with the inward-curved portion 43 of the outer bore 27 of the housing 26 . The outer bore-interfacing surfaces 17 of the plurality of insert segments 2 are at least in part collectively frusto-spherical. Each insert segment 2 has a concave inner bore-defining surface 14 and the plurality of concave inner bore-defining surfaces 14 define an inner bore 16 . Preferably, the outer bore 27 of the housing 26 has a ledge 45 , the insert segments 2 each have a bottom edge 21 , and the bottoms edges 21 of the insert segments 2 interface with the ledge 45 in the outer bore 27 , stabilizing the insert segments 2 . The take-up device 1 preferably has four insert segments 2 . Each insert segment 2 preferably has a substantially planar top surface 3 . The top surface 3 preferably has a concave inner bore-defining edge 4 with first and second ends 5 , a convex outer bore edge 7 with first and second ends 8 , a first substantially straight side edge 6 that connects the first end 5 of the inner bore-defining edge 4 to the first end 8 of the outer bore edge 7 , and a second substantially straight side edge 6 that connects the second end 5 of the inner bore-defining edge 4 to the second end 8 of the outer bore edge 7 . Each segment 2 preferably also has a tab 9 on the convex outer bore edge 7 , an inner bore-defining surface 14 that descends from the inner bore-defining edge 4 , and an outer bore-interfacing surface 17 that descends from the outer bore-defining edge 7 and tapers a bottom edge 21 . Preferably, the inner bore 12 of the take-up device 1 is threaded.
[0049] The housing 26 preferably also has a horizontal plate 29 and a vertical body 28 that surmounts the horizontal plate 29 and the outer bore 27 of the housing 26 is contained within the vertical body 28 . Preferably, the vertical body 28 is cylindrical and has an outer wall 34 with a top edge 33 , a plurality of indentations 35 extend down from the top edge 33 of the wall 34 , and a tab 9 of an insert segment 2 interfaces with each of the indentations 35 in the wall 34 of the cylindrical vertical body 28 . The insert segments 2 are preferably retained within the outer bore 27 by a compression member 46 . Preferably, the compression member 46 has an upper hard washer 47 , and a resilient lower soft washer 48 that pushes the insert segments 2 downward in the outer bore 27 and is restrained from upward movement by the upper hard washer 47 . The compression member 46 preferably also has a lower hard washer 47 that is between the resilient lower soft washer 48 and the insert segments 2 . Preferably, the upper and lower hard washers 47 each have an outer edge 51 with a plurality of projections 49 . The outer bore 27 preferably has a groove 40 connected to the indentations 35 in wall 34 of the cylindrical body 28 . Preferably, the projections 49 of the upper hard washer 47 project into the groove 40 in the outer bore 27 , restraining the compression member 46 . The projections 49 of the lower hard washer 47 preferably project into the indentations 35 in wall 34 of the cylindrical body 28 , stabilizing the compression member 46 .
[0050] Preferably, the take-up device 1 is part of a connection 110 that has a first structural member 115 to which the take-up device 1 is fastened, and a tie rod 24 with a top end 124 at least partially held within the inner bore 16 of the take-up device 1 by a plurality of the insert segments 2 . The first structural member 115 preferably is a top plate 115 in an at least partially wood frame wall 111 , and a bearing plate 120 is disposed between the first structural member 115 and the take-up device 1 . Preferably, the tie rod 24 is secured to a foundation 112 below the wood frame wall 111 .
[0051] The outer bore 27 of the take-up device 1 preferably has a central vertical axis 100 . Preferably, when the tie rod 24 is not parallel to the central vertical axis 100 of the outer bore 27 , the insert segments 2 that hold the tie rod 24 are canted so the inner bore 16 is parallel to the tie rod 24 where the tie rod 24 is held by the insert segments 2 but the inner bore is not parallel to the central vertical axis 100 of the outer bore 27 .
[0052] Preferably, the connection 110 is formed by inserting the top end 124 of the tie rod 24 into the inner bore 16 of the take-up device and fastening the take-up device 1 to the first structural member 115 . The take-up device 1 is preferably fastened to the first structural member 115 with a plurality of screws or nails 119 . Screws provide a stronger connection than nails, but nails are less expensive and can still often provide the necessary strength for the connection.
[0053] For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. | A ratcheting take-up device that compensates for imperfect alignment in a tie rod continuity system in the frame of a building wall. The upper ends of the tie rods are tightly clamped within the take-up device by domed segments inserted in a bowl-shaped housing. The segments are also forced together by a compression member in the housing. The domed shape of the segments and the bowl shape of the housing cooperate so that the segments can rotate in any direction to accommodate tie rods that are not perfectly vertical, without a corresponding loss of strength in the connection. | 4 |
CROSS REFERENCES TO RELATED APPLICATIONS
This application is a divisional application of Ser. No. 07/418,757 filed Oct. 5, 1989, U.S. Pat. No. 5,041,254 which in turn is a continuation-in-part of application Ser. No. 07/258,574 filed Oct. 17, 1988, now abandoned.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to an improved method of encapsulating a semiconductor device by heat curing an encapsulating compound comprising an epoxy, a hardener, a catalyst, a mold release agent, optionally a filler, optionally a colorant, optionally a coupling agent and a flame retardant system around a semiconductor device.
In the improvement, the flame retardant system comprises a lower percentage of antimony pentoxide, a lower percentage of sodium and an organic compound containing a higher percentage of halogen than prior art molding compounds.
In the improvement, molding compounds with an organic compound containing a higher percentage of halogen along with a lower percentage of antimony pentoxide and sodium have the unexpected results of releasing less free bromine ion upon heat aging and water extraction than prior art molding compounds. Also when the improved molding compounds were molded onto a semiconductor device, they exhibit unexpected superior high temperature stability and compatability, ball lift and live device performance.
The present invention also relates to improved flame retardant thermosetting epoxy molding compounds of the type comprising an epoxy, a hardener, a catalyst, a mold release agent, optionally a filler, optionally a colorant, optionally a coupling agent and a flame retardant system wherein the flame retardant system comprises a lower percentage of antimony pentoxide, a lower percentage of sodium, an organic compound containing a higher percentage of halogen than prior art molding compounds and optionally a basic metal oxide to reduce corrosion of metal conductor lines and pads of the semiconductor device.
The present invention also includes an improved encapsulated semiconductor device wherein the encapsulant is as described above, with as flame-retardant system comprising a lower percentage of antimony pentoxide, and sodium, an organic compound containing a higher percentage of halogen than prior art molding compounds and optionally a basic metal oxide to reduce corrosion of metal conductor lines and pads of the semiconductor device.
In all three instances the halogen-containing organic compound may be a separate ingredient, but is preferably a part of either the epoxy or the hardener. The halogen containing organic compounds can also be halogen-containing compounds which become chemically incorporated into the product of the epoxy resin and the hardener upon setting or part of other ingredients such as the lubricant or the colorant.
The term "epoxy molding compounds" as used herein means epoxy molding compound conventionally known in the art including any material containing two or more reactive oxirane groups. For example, the epoxy molding compound may have two or more epoxy groups in one molecule, including glycidyl ether type such as bisphenol A type, phenol novolac type, cresol novolac type and the like; glycidyl-ester type; alicyclic type; heterocyclic type and halogenated epoxy resins etc. The epoxy resins may be used either singly or as a mixture of two or more resins.
Similarly, the term "epoxy novolac molding compound" as used herein includes any phenol-derived and substituted phenol derived novolac hardener conventionally used as hardener for epoxy resins. For example, phenolic novolacs, cresolic novolacs and Bisphenol A derivatives are suitable. The epoxy novolac molding compounds may be used either singly or as a mixture of two or more compounds.
The term "catalyst" as used herein means a catalyst appropriate to the hardener used to promote the curing of the present composition. Such catalysts include basic and acidic catalysts such as the metal halide Lewis acids, e.g., boron trifluoride, stannic chloride, zinc chloride and the like, metal carboxylate-salts such as stannous octoate and the like; and amines, e.g., triethylamine, imidazole derivatives and the like. The catalysts are used in conventional amounts such as from about 0.1 to 5.0% by weight of the combined weight of epoxy and hardener.
The term "mold release agents" as used herein means chemical agents commonly used to assist the release of the cured epoxy molding compounds from the mold. For example, carnauba wax; montanic acid ester wax; polyethylene wax; polytetrafluoroethylene wax; glyceral monostearate; metallic stearates; paraffin waxes and the like are suitable.
The term "fillers" as used herein means one or more of the conventional fillers such as silica, calcium carbonate, calcium silicate, aluminum oxide, glass fibers, clay, and the like. The preferred filler is silica or a mixture of predominantly silica with other filler(s). The fillers usually are used in at least 50 percent by weight of the molding compound.
The term "colorant" as used herein includes colorant commonly used in epoxy molding compound, such as carbon black, pigments, dyes and the like.
The term "coupling agent," as used herein means a coupling agent known to improve wet electrical properties of the compound. The coupling agents may be of the silane type, characterized by the formula R'Si(OR) 3 ; where R' represents an organo-functional group such as amino, mercapto, vinyl, epoxy or methacryloxy, and OR represents a hydrolyzable alkoxy group attached to the silicon. Preferred coupling agents are described in U.S. Pat. Nos. 4,042,550 and 3,849,187, of which the descriptions are incorporated herein by reference.
The term "halogen-containing organic compound" or "organic compound containing halogen", as used herein, includes organic compound in which the halogen is present from any source including halogenation of a component or its precursor (such as a monomer) or by addition of halogen-containing monomers by reactions in which the halogen is not completely removed.
The halogen-containing organic compound used in a flame retardant system is preferably of the reactive type and further preferably has, as halogen, chlorine or bromine. Exemplary halogenated organic compounds are those types of polyglycidyl ether of bromophenol-formaldehyde novolac, commercially sold by Nippon Kayaku under the tradename "Bren™" and is of the general formula I: ##STR1## Other exemplary halogenated organic compounds are described in U.S. Pat. Nos. 4,042,550 and 4,282,136, of which the descriptions are incorporated herein by reference and include halogenated bisphenol A and derivatives of bisphenol A such as tetrabromobisphenol A. Additional examples of reactive halogenated organic compounds which are a part of the epoxy resins are glycidyl ethers of halogenated resins such as the diglycidyl ether of tetrabromobisphenol A.
The halogen containing organic compound may be a separate additive or may be contained in one or more of the organic components of the molding compound, especially the epoxy or the hardener, or possibly other components such as the lubricant, or the colorant or the filler (if organic).
Exemplary of reactive halogen-containing organic compounds which are part of the hardener are halogenated anhydrides such as tetrabromo and tetrachloro-phthalic anhydride. Tetrabromobisphenol A and other such halogenated monomers may also be considered part of the hardener, especially the phenol-derived or substituted phenol-derived hardener.
The term "antimony pentoxide" as used herein means antimony pentoxide in any available form. Preferably, antimony pentoxide used is Nyacol A1590 commercially sold by the Nyacol Division of P.Q. Corporation which has a very low sodium content of 0.03 to 0.06% by weight of the antimony pentoxide as compared to that of 3 to 4% in prior art products such as Nyacol A1588LP.
The term "basic metal oxide" as used herein means any metal oxide in any available form capable of neutralizing the acidity of the antimony pentoxide and thereby reducing the corrosion of the metal semiconductor device lines and pads, especially in regions where two different metals are in contact with each other. Preferably, the basic metal oxide is bismuth trioxide (Bi 2 O 3 ).
2. Description of Background Art
Epoxy resin compounds have often been used for encapsulation of semiconductor or device such as integrated circuits (IC), large scale integrated circuits (LSI), transistors and diodes, etc., or other electronic components. Such encapsulants generally comprise an epoxy, a hardener, a catalyst, a mold release agent, optionally a filler, optionally a colorant and sometimes a coupling agent.
Exemplary formulations of these ingredients are described in U.S. Pat. Nos. 4,710,796 to Ikeya et al., 4,282,135 to Hunt et al., U.S. Pat. No. 4,042,550 and references cited therein. Recently, the electronic industries require these epoxy molding compounds be flame retardant. Additives including halogenated compounds, transition metal oxides and hydrated alumina to improve the flame retardancy, as measured for example by Underwriters Laboratory Test 94V-0 of 1/16" bar have been reported. However, at high temperatures, these flame retardant additives detract from the compatibility of the encapsulant with semiconductor devices.
U.S. Pat. No. 4,710,796 to Ikeya et al. teaches a resin for encapsulating semiconductor device comprising an epoxy resin, curing agent, organic phosphine compound and at least one antimony oxide.
U.S. Pat. No. 4,042,550 teaches epoxyanhydride molding compounds with secondary fillers including antimony trioxide or antimony tetraoxide and halogenated compounds in flame retardant systems.
Similarly, U.S. Pat. No. 4,282,136 to Hunt et al. describes the use of synergistic flame retardants consisting of halogen-containing organic compounds and antimony pentoxide. The reference teaches that an encapsulant employing such a flame retardant system, when used to encapsulate a semiconductor device, has improved high temperature compatibility compared to similar molding compounds with antimony trioxide or antimony tetraoxide. However, the prior art epoxy molding compounds contains a high percent of sodium which is known to cause poor performance in semiconductor devices due to current leakage. See Moltzan et al., The Evolution of Epoxy Encapsulation Compounds For Integrated Circuits: A User's Perspective, Polymer for High Technology Electronics and Protronics, ACS Sym. Series No. 346, p. 521, Sep. 7-12, 1986.
While the prior art flame retardant combinations provides reasonable flame retardance and satisfactory compatibility on electronic devices, a need clearly exists for flame retardant epoxy molding compounds of all types with improved compatibility, performance, cost and lower toxicity.
Accordingly, it is an object of the present invention to provide an improved flame retardant thermosetting epoxy molding compound.
It is yet another object of the present invention to provide an improved method of encapsulating a semiconductor device.
It is yet another object of the present invention to provide an improved encapsulated semiconductor device.
These and other objects of the invention, as well as a fuller understanding of the advantage thereof, can be had by reference to the following descriptions and claims.
SUMMARY OF THE INVENTION
The foregoing objects are achieved according to the present invention by an improved epoxy molding compound comprising:
(a) about 5-25 percent by weight of compound of an epoxy;
(b) about 4-20 percent by weight of compound of a phenol-derived or a substituted phenol derived resin hardener;
(c) an effective amount of a catalyst for the reaction between said epoxy resin and said hardener in an amount of from about 0.1 to 10% by weight of the combined weight of epoxy and hardener;
(d) an effective amount of a mold release agent for the release of the cured molding compound from a mold in an amount of between about 0.01 and about 2 percent by weight of composition;
(e) between about 50 and 85 percent by weight of composition of a filler; and
(f) a flame retardant system of:
(1) ≦about 0.8% antimony pentoxide by weight of molding compound;
(2) from about 0.01-1% sodium by weight of antimony pentoxide; and
(3) a reactive organic compound containing at least about 1.0% of bromine by weight of molding compound which may include one or more of the other components; and
(4) ≦about 4.0% by weight of molding compound of a basic metal oxide which is most preferably bismuth trioxide.
Accordingly, Table 1 below summarizes the improved epoxy molding compounds.
TABLE 1______________________________________ PreferredDescription Range RangeFormulation A: (%) (%)______________________________________Epoxy Cresol Novolac resin 5-25 10-16epoxy resin (preferably at least 1.0-1.8BREN ™) -containing about 1.0bromine (%)sodium (present in the 0.01-1 0.03-0.06antimony pentoxide)antimony pentoxide ≦0.80 0.40-0.80bismuth trioxide ≦4.0 1.60-3.20Carbon black colorant 0.05-0.5 0.1-0.5phenol Novolac Hardener 4-20 4-12Fused Silica (SiO.sub.2) filler 50-85 60-80silanes 0.05-2.0 0.1-1.5catalysts 0.01-10.0 0.5-2.0wax lubricants 0.01-2 0.02-1.0______________________________________
The improved epoxy molding compounds of the present invention are suitable for use in encapsulating a semiconductor device.
According to the present invention, the said improved epoxy molding compounds may be prepared by any conventional method. For example, the ingredients may be finely ground, dry blended and then densified on a hot differential roll mill, followed by granulation. Generally, the ingredients (or any portion of them) may be prepared as a fine powder, fed directly into a compounding device such as an extruder prepared as a premix of raw materials. If less than all of the ingredients are present in the initial form, the remainder of the ingredients can be added prior to or during densification.
Densification can be by mechanical compacting using a preformer or a combining mill in the case of a fine powder, or by an extruder or differential roll mill in the case of the fine powders, direct feed or premix. Premixes or densified forms (such as preforms and granular forms), containing less than all of the ingredients can also be fed to the ultimate mold in the system with the remaining ingredients in a similar or different form.
The present invention includes flame retardant molding compounds in any physical form or even as systems of two or more components. Where two or more components are used, one should contain the epoxy, the other the hardener. Preferably, the catalyst is in the hardener component to avoid catalyzed homopolymerization of the epoxy.
In a preferred embodiment, in the laboratory, the dry ingredients of the formula are preground to a fine powder and then mixed in a large plastic bag. The liquid ingredients (i.e., the silane coupling agents) are added to dry ingredients and the mixture is mixed again by hand. The mixture is then treated on a large two-roll mill (one roll heated to ˜90° C. and the other cooled with tap water) until a uniform sheet (˜6" wide by 24" long) is obtained. The sheet is allowed to cool and then ground to a fine powder.
In another preferred embodiment, in the pilot plant and during large scale production, the dry ingredients are mixed in a large hopper, the liquid ingredients are added in a homogeneous manner to ensure blending, and mixing continues. This mixture is then extruded (with heating) to give a continuous sheet which is cooled and grounded. The final ground powder can be used as is, or compacted (densified) in a preformer to give tablets (performs) of desired shape and size.
These compounds may be molded into various articles by application of the appropriate temperature and pressure. For example, molding conditions for the encapsulated semiconductor of the present invention may range from about 300° to 400° F., (about 149°-204° C.), preferably about 350° to about 375° F., (about 177°-191° C.), at 400 to 1,500 psi, (about 28-105 kg/cm 2 ), for a time ranging from about 30 to 120 seconds, preferably 60 to 90 seconds.
Any suitable molding apparatus may be employed, such as a transfer press equipped with a multi-cavity mold.
The ratio between the various ingredients may vary widely. In general, the epoxy will be in proportion to a novolac hardener so as to give a mole ratio of oxirane:reactive hydroxy between about 0.8 and 1.25. Similarly, the epoxy will be in proportion to an anhydride hardener so as to give a ratio of oxirane:anhydride equivalent between about 1.0 and 1.7, preferably between about 1.11 and 1.25.
The catalyst employed is generally applied at levels sufficient to harden the epoxy molding compound under anticipated molding conditions. Amounts between about 0.1 and 5 weight percent (by combined weight of epoxy and hardener) are sufficient.
The mold release agent will be employed in amounts sufficient to give good release from the mold and also to improve the wet electrical properties of the encapsulated semiconductor device. Amounts between about 0.01 and 2 percent by weight of total compound, preferably between about 0.02 and 1 percent by weight of total compound can be used.
The total amount of filler may range from 0 up to about 85 percent of the total compound. Preferably, the filler comprises a total of more than 50 weight percent of the total compound and more preferably between about 60 and about 85 weight percent of the total compound. Also, preferably, between about 60 and about 80 weight percent of the total compound is a silica filler.
Colorants, if employed, are generally in amounts sufficient to give encapsulated devices the desired color preferably black. Amounts between about 0.1-1.5% by weight of total compound can be employed.
Coupling agents, and in particular silane coupling agents, are provided in amounts sufficient to give the desired wet electrical properties and preferably between about 0.05 and 2 weight percent by total weight of compound, more preferably between about 0.1 and 1.5 weight percent by total weight of compound.
The epoxy molding compound obtained may be used to encapsulate semiconductor devices by any conventional method. For example, the preferred improved epoxy molding formulations comprising 0.4-0.8% percentage of antimony pentoxide; 0.03-0.06% sodium content (by weight of antimony pentoxide) and an organic compound containing about 1.0-1.8% of bromine when molded on test devices have unexpected superior thermal device compatibility, flameretardancy, ball lift property, live device performance compared to prior art formulations as disclosed in U.S. Pat. No. 4,282,136 to Hunt et al.
The use of a lower percentage of antimony pentoxide in the present invention is preferred because antimony pentoxide is expensive and toxic.
Improved epoxy molding formulations comprising 0.4-0.8 percent of antimony peroxide, 0.03-0.06 percent of sodium (by weight of antimony pentoxide) and an organic compound containing about 1.0-1.8 percent of bromine; when molded on test devices (autoclave) give superior ball lift test results. The ball lift (autoclave) test is routinely performed by semiconductor manufacturers to assess reliability of the devices in a humid environment. In the ball lift test, percent of ball bonds lifted when pulled and loss of bond strength as a function of the number of hours the devices held in an autoclave under two conditions (121° C., 15 psi steam and 135° C., 30 psi steam) are measured.
The improved epoxy molding formulations are uniquely effective in delaying or eliminating the "ball lift problem" in a molded semiconductor device. The improved epoxy molding compound shows no ball lift out to 1200 hours at both 15 and 30 psi while comparable sample with antimony trioxide shows 50% ball lift in 370 hours at 30 psi.
Further the improved epoxy molding compounds unexpectedly give superior live-device performance than the other combination of brominated resin and antimony trioxide/pentoxide. In the live-device performance test, National Semiconductor LF412 operational amplifiers are encapsulated with the improved epoxy molding compound. A group of about 40 of these molded packages (14 pin dual in-line) are subject to a high humidity environment (131° C., 100% relative humidity in an autoclave at 30 psi gauge pressure) with no bias. The parts are then pulled from the autoclave at regular intervals and examined for electrical failure (gain less than 7 or greater than 65).
Nineteen of the thirty eight National Semiconductor LF412 operational amplifiers encapsulated with the improved epoxy molding compound remain operational after 3036 hours of testing. On the other hand, nineteen of the thirty-eight operational amplifiers molded with comparable prior art compound containing 2.4 percent antimony pentoxide failed in less than 198 hours.
This is especially surprising in view of the prior art teaching that a higher percent antimony pentoxide (≧1%) will give formulation with better synergistic performance. One skilled in the art of molding compound systems would not be lead to use ≦ about 0.8% antimony pentoxide because prior art teaches ≦ about 0.8% antimony pentoxide is expected to give poor flame retardancy and also insufficient to give improved "ball lift" performance.
It is well known in the art that the interaction of organic brominated species with the Au/Al intermetallic is the predominant failure mechanism, causing "ball lift" problems. (See Khan et al., Effect of High Thermal Stability Mold Material On the Gold-Aluminum Bond Reliability in Epoxy Encapsulated VLSI Devices, in Proc. IEEE. Paper presented at the Int. Reliability Physics Symp., pp. 40-49, April, 1988). Thus the use of an organic compound containing a higher amount of bromine, as flame-retardants, in molding compound compositions to give improved ball-lift and live device performance is unexpected.
The use of an organic compound containing a higher percent of bromine in the improved epoxy molding compound has the unusual properties of releasing less free bromine ion, upon heat aging and water extraction than prior art compounds.
The free bromine ion released from the molding compounds is determined by the "bromine extraction test." In the bromine extraction test, the molding compound is heat cured at 175° C. for 4 hours. The cured compound is then grounded and screened through 35-mesh sieve. The sieved compound is then heat aged at specific temperatures, preferably in the range from 200°-240° C. At specific intervals, small amounts of compound are removed. A one gram sample is then mixed with 100 ml of deionized water and reflux for 24 hours. The amount of free bromine ion extracted from the compound is then determined by ion chromatography.
In the present invention, after exposing the molding compounds at 200° C. for 500 hours, bromine ion extracted by water was 175 ppm for the device with the improved epoxy molding compound and 400 ppm for the prior art molding compound devices. At 240° C., after 500 hours, bromine extracted by water was 240 ppm for improved epoxy molding compound devices and 1000 ppm for prior art epoxy molding compound devices.
The present invention is not restricted to the above ingredients but may include other ingredients which do not detract from flame retardant properties of the flame retardant agent. Accordingly, other organic or inorganic materials may be added under the above conditions, including antimony trioxide and antimony tetraoxide in total amounts less than the amount of antimony pentoxide. Additionally, basic metal oxides such as bismuth trioxide may be added to further improve the live device performance of the encapsulated semiconductor devices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 describes test results of the ball lift (autoclave) test on molded devices (Examples 6-9) as a function of time and the estimated hours of 50% occurrence of ball lift at 15 psi.
FIG. 2 describes test results of the ball lift (autoclave) test on molded devices (Examples 6-9) as a function of time and the estimated hours of 50% occurrence of ball lift at 30 psi.
FIG. 3 describes test results of the ball lift test on the encapsulated devices Example 14.
FIG. 4 describes test results of the bromine extraction test performed at 200° C. upon the molding compound from Example 14.
FIG. 5 describes test results of the bromine extraction test performed at 240° C. upon the molding compound from Example 14.
FIG. 6 describes test results of the ball lift (autoclave) test on the encapsulated devices Examples 14 and 19-21 as a function of time at 15 psi.
FIG. 7 describes test results of the ball lift (autoclave) test on the encapsulated devices Examples 14 and 19-21 as a function of time at 30 psi.
DESCRIPTION OF PREFERRED EMBODIMENTS
The following nonlimiting examples further illustrate the present invention relating to an improved epoxy molding compound, method and encapsulated device. All parts are by weight unless indicated otherwise.
EXAMPLES 1-4
Epoxy encapsulants are prepared from the modified formulation A indicated in Table 2. The four groups of formulation differ in the presence/absence of antimony trioxide and/or brominated resin of the following type. ##STR2##
TABLE 2______________________________________ ExamplesDescription 1 2 3 4molding compound % % % %______________________________________Crystalline silica 71.36 73.76 71.36 73.76fillerCarbon black coloring 0.23 0.23 0.23 0.23Phenol Novolac 8.64 8.64 9.06 9.06HardenerEpoxy Cresol Novolac 15.00 15.00 15.82 15.82resinSilane coupling agent 0.48 0.48 0.48 0.48catalyst 0.25 0.25 0.25 0.25wax lubricants 0.40 0.40 0.40 0.40Brominated bis-A* 1.24 1.24 -- --type resinantimony trioxide 2.40 -- 2.40 --______________________________________ *A tetrabromobisphenolA glycidyl ether resin with a softening point of 70-80° C. determined by Durran's method, an epoxy equivalent weigh of 450-470, and 49 percent by weight of bromine.
EXAMPLE 5
The four compounds as described in Examples 1-4 are molded onto test devices and then subjected to the ball lift (autoclave) test. The test results as a function of time and the estimated hours to 50% occurrence of ball lift, or hours to 50% of initial bond-pull strength are summarized in Table 3.
TABLE 3______________________________________LS00 - Bond Strength and Ball Lift Hours to 50% Hours to 50% Pull Strength Ball Liftpsi 15 psi 30 psi 15 psi 30______________________________________Examples1 540 230 460 1602 1040 410 910 3503 630 200 500 1804 >>1300 1170 >>1300 1130______________________________________
A review of the data shows that the gold wire ball bond to the aluminum bonding pad on the devices are degraded (loss of physical bonding strength) by the presence of the flame-retardant ingredients (brominated resin of the bis-A type and antimony trioxide) in the plastic encapsulant under the high moisture environment of the autoclave. Specifically, the presence of antimony trioxide is found to be the overriding factor in causing ball lift, with the brominated resin playing a secondary role and only when the antimony content is lowered. When both of these ingredients are absent [Example 4], ball lift could not be detected out to 1300 hours at 15 psi.
EXAMPLES 6-9
A series of epoxy encapsulant compounds comparing the effectiveness of antimony pentoxide and trioxide as a flame retardant synergist are prepared in the laboratory then molded on test devices as indicated in Table 4.
TABLE 4______________________________________molding Examplescompound 6 7 8 9______________________________________Brominated Brominated* Brominated Bren ™ Bren ™Resin Ether EtherBromine in .60 .60 .895 .895resin (%)Antimony 2.4 -- 0.80 --Trioxide (%)Antimony -- 2.4 -- 0.80Pentoxide (%)______________________________________ *The brominated resin is a tetrabromobisphenol-A glycidyl ether resin wit a softening point of 70-80° C. determined by Durran's method, an epoxy equivalent weight of 450-470, and 49 percent by weight of bromine.
EXAMPLE 10
The properties of the cured encapsulants of Examples 6-9 are further determined by total burn times of 1/16" bar according to UL-94V-0. The test results are summarized in Table 5.
TABLE 5______________________________________ 1/16" Bars TotalExample # 1st Burn/2nd Burn/Burn Time 94V-0 Status______________________________________6 0 6 19 sec Pass 0 2 2 0 0 6 1 27 4 6 28 pass 0 2 2 5 2 2 3 28 2 5 1 5 54 Fail.sup.+ 2 4 0 3 2 309 2 30 88 Fail.sup.+ 8 2 3 6 5 4 3 25______________________________________ .sup.+ The encapsulated device failed the UL94V-0 test for 1/16" bar because only 0.89% of bromine (2.5% of Bren ™) is used in the molding compound. The encapsulated device will pass the UL94V-0 test if 1/8" bar or at least 1.0% of bromine is used in the molding compound.
In contrast to prior art teachings, the data in Table 5 shows antimony pentoxide give poorer flame-retardance relative to antimony trioxide as measured by (UL-94V-0) total burn times of 1/16" bar.
EXAMPLE 11-12
The molded devices (Examples 6-9) are subjected to the ball lift (autoclave) test as described in Example 5. The test results as a function of time and the estimated hours of 50% occurrence of ball lift at both 15 and 30 psi conditions are summarized in Table 6 and FIGS. 1-2.
TABLE 6______________________________________LF412R - Bond Strength and Ball Lift Hours to Hours to 50% Pull Strength 50% Ball LiftExample Description 15 psi 30 psi 15 psi 30 psi______________________________________6 1430 300 1430 2807 >>1500 ˜1100 >>1500 ˜10008 >1500 400 -1530 3709 >>1500 >>1200 >>1500 >>1200______________________________________
A review of the data shows that when antimony pentoxide is used in place of antimony trioxide, the ball lift problem is either delayed or it can not be detected at all, depending on the brominated resin used. The two samples with antimony pentoxide (7 and 9) show much reduced ball lift compared to samples 6 and 8. Also, sample 9 shows no ball lift out to 1200 hours at both 15 and 30 psi, while the comparable sample (8) with antimony trioxide shows 50% ball lift in 370 hours at 30 psi.
EXAMPLE 13
National Semiconductor LF412 operational amplifiers are encapsulated with encapsulants described in Examples 6-9. A group of about 40 of these molded packages (14 pin dual in-line) are subjected to the live device performance test.
The results of the live device test are summarized in Table 7.
TABLE 7______________________________________Live Device Performance at 30 psi, no bias of LF412Operational Amplifiers in 14 pin DIP packagesencapsulated with molding compounds from Examples 6-9______________________________________Examples 6 7 8 9Initial Number 37 38 40 38of Sample DevicesHours Cumulative Number of Failures______________________________________ 0 0 0 0 0 44 0 0 0 0 154 0 8 0 0 198 l 22 0 2 286 2 23 1 2 352 2 26 1 2 440 3 28 2 3 506 3 32 2 3 594 4 No 2 3 660 5 Further 2 3 748 5 Testing 4 3 792 5 4 3 924 18 13 91056 19 13 91210 22 13 91364 28 19 111518 No 22 121672 Further 23 121826 Testing 28 121980 No 152134 Further 182442 Testing 192750 193036 19______________________________________
A review of the data shows that the combination of Bren™ and antimony pentoxide in the improved molding compound encapsulated device gives superior live-device performance than the other combination of brominated resin and antimony trioxide/pentoxide.
EXAMPLE 14
On a pilot plant scale epoxy encapsulants are prepared from the formulation indicated in Table 8. The improved molding compound is then molded onto test devices as in Example 5.
TABLE 8______________________________________ ExampleDescription 14______________________________________Epoxy Cresol Novolac resin 13.26epoxy resin (BREN ™) - 1.36.sup.+containing bromine (%)antimony pentoxide 0.75.sup.++Carbon black coloring 0.20Phenol Novolac Hardener 9.10Fused Silica (SiO.sub.2) filler 71.39Silane coupling agent 0.70catalysts 0.35wax lubricants 0.45______________________________________ .sup.+ The 1.36% of bromine equivalents to 3.8% Bren .sup.++ The level of 0.75% commercial antimony pentoxide represents an actual level of 0.67-0.68%
EXAMPLE 15
The properties of cured encapsulants of Example 14 are tested according to UL-94V-0 (one sixteenth inch). The test results are summarized in Table 9.
TABLE 9______________________________________ 1st Burn 2nd Burn______________________________________Example 0 2 Pass14* 0 0 1 1 0 0 0 0______________________________________ *Example 14 is molded at 350° F., postcured six hours at 175° C.
EXAMPLE 16
The encapsulated device from Example 14 is subjected to the ball lift test. Test results are summarized in FIG. 3. The test results show that the cured encapsulant of Example 14 does not cause degradation of the wire bond strength after 1500 hours at 135° C., 30 psi steam.
EXAMPLE 17
The molding compound from Example 14 is subjected to the bromine extraction test. Test results are summarized at FIG. 4.
The test results show that the heat cured molding compound of Example 14 after heat aging at 200° C. for 500 hours releases bromine ion extracted by water of 175 ppm concentration. This is far lower than the 400 ppm water extractable bromine ion concentration released by encapsulant of prior art epoxy molding compounds under the same condition.
EXAMPLE 18
The bromine extraction test as described in Example 17 was repeated for the molding compound from Example 14 at 240° C. Test results are summarized in FIG. 5. The test results show that the heat cured encapsulant molding compound of Example 14 after heat aging at 240° C. for 500 hours releases bromine ion extracted by water of 240 ppm concentration. This is far lower than the 1000 ppm water extractable bromine ion concentration released by encapsulant of prior art epoxy molding compound under the same condition.
EXAMPLE 19-21
Epoxy encapsulants (Examples 19-21) using 0.75% Sb 2 O 3 , 0.50% Sb 2 O 3 /0.25% Sb 2 O 5 and 0.25% Sb 2 O 3 /0.50% Sb 2 O 5 respectively are prepared in the laboratory. Examples 19-21 are of similar compositions as used in Example 14 except that antimony trioxide or a mixture of antimony trioxide/pentoxide are used in place of antimony pentoxide.
EXAMPLE 22
The epoxy molding compounds prepared in Examples 19-21 are molded on test devices as in Example 14.
The encapsulated devices from Examples 14, 19-21 are subjected to the ball lift test as described in Example 5. Test results as a function of time at both 15 and 30 psi conditions are summarized in FIGS. 6 and 7 respectively. The improved epoxy molding compound as described in Example 14 containing 0.75% antimony pentoxide gives superior ball lift performance than the other combination of brominated resin and antimony trioxide/pentoxide mixtures.
EXAMPLES 23-25
Epoxy encapsulants are prepared from the formulations indicated in Table 10. The formulations are similar to that presented in Table 8 except for the content of antimony pentoxide and bismuth trioxide.
TABLE 10______________________________________ ExampleDescription 23 24 25______________________________________Epoxy Cresol Novolac resin 13.26 13.26 13.26epoxy resin (BREN ™) - 1.36.sup.+ 1.36.sup.+ 1.36.sup.+containing bromine (%)bismuth trixoide -- 1.6 1.6antimony pentoxide 0.4 -- 0.4Carbon black coloring 0.20 0.20 0.20Phenol Novolac Hardener 9.10 9.10 9.10Fused Silica (SiO.sub.2) filler 71.39 71.39 71.39Silane coupling agent 0.70 0.70 0.70catalysts 0.35 0.35 0.35wax lubricants 0.45 0.45 0.45______________________________________ .sup.+ The 1.36% of bromine equivalents to 3.8% Bren
EXAMPLE 26
National Semiconductor LF412 operational amplifiers are encapsulated with encapsulants described in Examples 23-25. A group of about 40 of these molded packages (14 pin dual in-line) are subjected to the live device performance test at 15 psi and no bias of the operational amplifiers.
The results of the live device test are summarized in Table 11.
TABLE 11______________________________________Live Device Performance at 15 psi, no bias of LF412Operational Amplifiers in 14 pin DIP packagesencapsulated with molding compounds from Examples 23-25______________________________________Examples 23 24 25Initial # of 38 37 36Sample Devices Cumulative Number ofHours Parametric Failures______________________________________ 44 1 1 0 88 2 1 0 176 2 1 0 242 5 1 0 330 6 1 0 396 7 3 0 440 10 5 0 506 11 5 0 594 14 10 3 660 20 16 7 748 24 17 11 814 No further 28 17 924 testing No further 171056 testing 20 No further testing______________________________________
The test data indicates that the combination of antimony pentoxide and bismuth trioxide at the same level of Bren™ (Example 25) gives superior live-device performance than the formulation having antimony pentoxide alone or bismuth trioxide alone.
Furthermore, additional burn time and ball lift testing of Example 25 indicates the formulation maintains adequate flame retardancy and adequate resistance to ball-bond degradation comparable to formulations having antimony pentoxide alone.
The foregoing examples are intended to illustrate without limitation, the improved flame retardant epoxy molding compound, method and encapsulated device. It is understood that changes and variation can be made therein without departing from the scope of the invention as defined in the following claims. | An improved flame retardant epoxy molding compound comprises an epoxy, a hardener preferably of the novolac or anhydride type, a catalyst, a mold release agent, preferably a filler, preferably a colorant, preferably a coupling agent, an organic compound containing a higher percent of halogen (which can be part of the resin or the hardener), preferably the polyglycidyl ether of the bromophenol-formaldehyde novolac type, preferably containing at least about 1.0% of bromine by weight of the molding compound, a lower percent of sodium, preferably in the range of 0.03-0.06% by weight of the antimony pentoxide, a lower percent of antimony pentoxide, preferably in the range of ≦ about 0.8% by weight of the molding compound, and an amount of bismuth trioxide ≦ about 4.0% by weight of the molding compound.
The improved flame retardant epoxy molding compounds when used to encapsulated semiconductor devices have improved high temperature stability and compatibility, ball-lift performance, live-device performance, cost and lower toxicity compared to similar prior art molding compounds. | 8 |
BRIEF SUMMARY OF THE INVENTION
A shroud for use with a digging bucket lip has an integral body with a rounded forward portion and a divided rearward portion affording two parallel legs adapted to receive a part of the lip between them. Apertures through the legs each slidably receive a ring welded on its inner wall to the lip.
PRIOR ART
No particularly pertinent prior art is known to the applicants.
BRIEF DESCRIPTION OF THE SEVERAL VIEW OF THE DRAWINGS
FIG. 1 is a plan of a portion of a digging bucket provided with the customary digging teeth and equipped with the shrouds of this invention, certain portions of the bucket being broken away to reduce the size of the figure.
FIG. 2 is a cross-section, the plane of which is indicated by the line 2--2 of FIG. 1.
FIG. 3 is an enlargement of a portion of the structure shown in FIG. 2.
FIG. 4 is a plan of the structure shown in FIG. 3, various portions being broken away.
FIG. 5 is a cross-section, the plane of which is indicated by the line 5--5 of FIG. 4.
DETAILED DESCRIPTION
In the carrying out of various excavating, mining and dredging operations, it is customary to provide a bucket usually of heavy-walled construction and of metal and including a lower generally planar transverse portion 6 that normally is substantially horizontal and that at its sides 7 curves upwardly to provide at least a partial enclosure.
The bucket is characterized by a leading lip 8 on which are mounted a number of digging teeth 9. These are customarily spaced apart across the width of the bucket and project forwardly therefrom a substantial distance. While there are various different constructions of teeth 9, they are only generally illustrated herein, as no particular tooth pattern is required. The spaced mounting of the teeth on the bucket is customary in order that the teeth may dig readily into the material being excavated. Customarily also, such teeth are provided with removable tips or caps since they are subject to very severe wear, and the caps themselves are changed from time to time to preserve digging integrity.
While in some instances no further protection of the bucket is required, in many instances it has been found that the lip 8 in between the various teeth 9 is subject to substantial abrasion, wear and disintegration due to impact of the excavated materials.
To obviate some of this wear and to restore to better working conditions a bucket that has already become worn in the lip area, a shroud 11 is particularly provided in accordance with out invention. A number of such shrouds are afforded, each one being mounted on the bucket lip in between adjacent ones of the digging teeth 9 and sometimes are mounted on the forward edges of the bucket sides, also.
Each shroud 11 has a relatively blunt forward portion 12 of a length substantially less that the length of the teeth 9 and of a width something less that the width between adjacent teeth but occupying a fairly large portion of the space therebetween, The shroud 11 is conveniently fabricated of cast high alloy steel and is given a quasi-teardrop shape in longitudinal cross-section substantially as shown in FIG. 2. The shroud has a leading portion 13 which may be somewhat sharper than the remainder of the body and that swells or expands and then diminishes. The shroud is bifurcated to afford a pair of legs 14 and 15 defining a space 16 between them of a dimension to fit over the lip 8 of the bucket. The fit need not be a particularly close one and is perferably looser than a driving fit, so that a shroud easily can be put into position with its legs straddling the forward portion of the lip and centered approximately between the adjacent teeth 9.
Preferably the top and bottom boundaries of the slot between the legs are substantially planar and parallel to each other, just as the outer boundaries of the shroud preferably taper to a lesser thickness toward the rear of the shroud.
In especial accordance with the invention, the legs 14 and 15 are provided with openings 21 and 22. The openings usually are made in alignment on a transverse axis 23 (FIG. 4). Each opening is substantially non-circular or elliptical in plan with its long axis extending transversely, as shown in FIG. 4.
Designed to fit into either of the openings is one of a number of rings 24 of a thickness approximately equal to the thickness of the adjacent leg and of a plan contour also elliptical and slightly smaller than the contour of the opening. The ring 24 in cross-section, as shown in FIG. 4, is preferably tapered from a narrow portion adjacent the outside or top to a wide portion adjacent the bottom or lip, so that the inner wall 26 of the ring is tapered. The ring is of a dimension so that it can readily be dropped into the opening 21 and can be moved easily into abutment with the adjacent lip 8. It is not necessary to use any tools or special force to install any of the rings.
After a ring has been put into position in abnutment with the lip and against the sides of the opening 21, it is fastened in place by a bead 27 of weld material securing the ring in position on the lip itself. Normally, no weld is made between the ring and the shroud 11. After both rings for each shroud have been welded into position, it is found in practice that the shroud is well fixed and acts to protect the otherwise exposed leading edge of the lip. The overall performance of the bucket is substantially improved, for a uniform edge is presented and material is well guided.
In some instances even though the bucket lip 31 (FIG. 5) is out of shape or is worn, the positioning of a ring 32 in each of the openings 33 and 34 is an effective positioner. In the event there has been substantial wear of the lip, the rings may not extend entirely to the outside surfaces 36 of the shrouds. Even so, a line 37 of welding is usually sufficient to hold the parts in position, although if desired an additional bead of welding 38 can be afforded.
In installations of this sort, it is found that the transversely elliptical shape of the ring is effective to assist in resisting twisting of the shroud on the bucket lip and affords an increased area of welding over and above a circular interconnection.
In all cases, the addition of the shrouds does not in any way adversely affect the digging ability of the customary teeth 9, but does serve to preclude or make up for undue wear on the intervening portions of the bucket lip, so that an overall improvement in service is afforded.
While there is no size limitation on the shrouds, a representative weight of a shroud cast in low alloy steel is in the range of 250 to 300 pounds. | A digging bucket lip is provided with one or more shrouds, each shroud having a blunt forward portion and a rearward portion divided into two spaced-apart legs. There are apertures through the legs, preferably in alignment. Rings are slidably disposed in the apertures and are welded on their inner margins to the lip disposed between the legs. | 4 |
BACKGROUND OF THE INVENTION
The invention relates to the field of the restoration of noise-affected audio recordings. It is of relevance to signals which have been recorded on any medium (magnetic tape, vinyl record, cylinder) and then sampled and stored on a computer medium.
Pre- and post-echoes constitute a defect commonly encountered in this type of signal. Pre- or post-echoes are very frequently encountered in analog recordings on a magnetic medium (tape, cassettes) and also on records, when a passage in which the signal is of low sound level precedes or follows a passage of high sound level. The presence, a few moments before a signal of high level, of a greatly attenuated copy of this signal, clearly audible if the useful signal at this moment is of low level, is referred to as pre-echo. Similarly, the presence a few moments after a signal of high level of a greatly attenuated copy of this signal, which may be audible if the useful signal is of low level at this moment, is referred to as post-echo.
Pre- and post-echoes stem, in the case of magnetic tapes, from the magnetization, through the backing of the tape, of one turn by the adjoining turns. In the case of recordings on vinyl record, the phenomenon stems from plastic modification of a groove through the engraving of the adjacent grooves.
In all of what follows, the term "echo" will denote either a pre-echo or a post-echo which it is desired to eliminate from an audio recording.
In the context of telecommunications, the rather similar problem of echo cancellation arises, the echo now being due to the round trip time for the path separating the talker from his opposite party across the communication system. However, the techniques used in the context of communications allow the echo to be attenuated only if the transmission channel can be identified in the absence of any useful signal, this not being the case in the context of audio recordings. Indeed, in order to apply the techniques used in communication, it would be necessary for the echo to be able to be heard entirely on its own, that is to say in the absence of any useful signal. In the context of audio recordings, the echoes are troublesome precisely when they are heard in the presence of a useful signal which should not be impaired.
The purpose of the present invention is to eliminate or greatly attenuate the pre-echoes and post-echoes affecting an audio recording, in the presence or absence of any useful signal, and to do so without impairing the latter.
SUMMARY OF THE INVENTION
The invention thus proposes a process for eliminating, from a first segment of a digitized audio signal, an attenuated replica of a portion of a second segment of the digitized audio signal, said portion of the second segment exhibiting a time shift with respect to said replica, this process comprising the following steps:
determining a value representative of an attenuation factor between said portion of the second segment and said replica for a plurality of values of a frequency index k;
for a plurality of values of an integer p, calculating respective short-term discrete Fourier transforms X(p,k) and Xτ(p,k) of the audio signal shifted by pR samples and of the audio signal shifted by pR+τ samples, R denoting a predetermined integer at most equal to the length T of said short-term discrete Fourier transforms and τ denoting said time shift expressed as a number of samples, calculating a corrected signal in the frequency domain by nonlinear transformation of the short-term Fourier transform X(p,k) taking account, for each of said plurality of values of the frequency index k, of the value representative of the attenuation factor and of the short-term Fourier transform X.sub.τ (p,k), and calculating a short-term component of a corrected signal in the time domain by short-term inverse Fourier transform of the corrected signal in the frequency domain; and
forming the corrected signal in the time domain by weighted summation of the short-term components thereof.
The nonlinear transformation used to calculate the corrected signal in the frequency domain Y(p,k) is for example of the form: ##EQU1## g(k) denoting the value representative of the attenuation factor for the frequency index k, f(.) denoting a decreasing real function, and |.| representing the modulus of a complex number.
This process uses a simple model of echo production: the echo (pre- or post-) is simply an attenuated and time-shifted version of the signal of which it is the replica. The nonlinear attenuation technique based on the use of the Fourier transform exhibits the following advantages in particular: it makes it possible to obtain very good attenuation factors even in the presence of errors in the estimate of the delay τ; it makes it possible to over-estimate the attenuation factor and to obtain a yet greater reduction in the echo; it does not impair the useful signal.
When the time shift is not known precisely a priori, its prior determination advantageously includes the following steps:
performing a discrete Fourier transform, of predetermined length N, of the first segment of the digitized audio signal in order to obtain a first function of the frequency domain;
performing a discrete Fourier transform of length N of the second segment of the digitized audio signal in order to obtain a second function of the frequency domain;
calculating a truncated correlation function between the first and second segments by inverse discrete Fourier transform of length N of a third function of the frequency domain taking the value U(m) * ·V f (m) for each frequency index m for which |U(m)|<g max · |V f (m)| and the value 0 for the other frequency indices m, U(m) and V f (m) respectively denoting the values for the frequency index m of the first and second functions of the frequency domain, g max denoting a predetermined coefficient, and (.) * representing the complex conjugate; and
calculating the time shift from the value of an integer for which the modulus of said truncated correlation function exhibits a maximum.
It is thus possible to solve the problems raised by the presence of useful signals during the step for estimating the shift, by virtue of a method of estimation by filtering/correlation in the frequency domain.
The determination of the value representative of the attenuation factor advantageously includes the following steps:
obtaining an estimate of the attenuation factor; and
increasing by a predetermined quantity said estimate in order to yield said representative value of the attenuation factor.
The estimate of the attenuation factor may be dependent on or independent of the frequency index k. The obtaining of this estimate can include the following steps:
for a plurality of values of an integer q, calculating respective short-term discrete Fourier transforms of length T U(q,k) and V(q,k) of the audio signal shifted by qR samples belonging to the first segment and of the audio signal shifted by qR+τ samples belonging to the second segment; and
calculating the estimate of the attenuation factor via: ##EQU2## or, if the estimate g is independent of the frequency index k, via: ##EQU3## where Q=1+E (n f -n d -T)/R! with n f -n d denoting the length of the first segment and E .! representing the integer part.
The determination of the attenuation thus takes into account the method used in the subsequent echo elimination step. The attenuation factor is estimated by a method of minimization of the least squares type in the frequency domain.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are timing diagrams of signals used in an example implementation of the process according to the invention, in the case of a pre-echo in FIG. 1 and of a post-echo in FIG. 2.
FIGS. 3 to 5 are flow charts respectively of procedures for determining the time shift, for determining the value representative of the attenuation factor and for eliminating the echo, which can be used for the implementation of the process.
FIG. 6 is a schematic representation of one part of the echo elimination procedure represented in FIG. 5.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1 and 2 illustrate a section of an audio signal x(n) obtained by sampling and digitizing a recording affected by echoes. The sampling frequency F e is for example of 44.1 kHz. The signal x(n) is available in the form of a computer file which can be accessed by a computer programmed to implement the process according to the invention.
It is assumed that a first segment A containing an echo E pre , E post and a second segment B, one portion O of which is the "original" of which this echo is a replica, have already been located. Such locating is readily performed aurally. Since the unwanted echo is clearly audible, the operator can pinpoint instants (samples n d and n f ) bracketing the echo, which will constitute the start and end of the segment A. Having picked out the echo, the operator can recognize and locate the original O in the same way. It is also possible to perform automatic locating of the segments in which echoes and their originals are liable to be found, for example by analysing the energy levels of the signal so as to mark the soft passages preceded or followed by loud passages. The locating of the segments need not be precise in order for the process according to the invention to work.
The locating of the segments A and B makes it possible to furnish the following initial data: start and end samples n d , n f of the first segment A, minimum and maximum values τ min , τ max of the time shift between the echo and the original, expressed in terms of number of samples. The start and end samples of the second segment B correspond to n d +τ min and n f +τ max . The actual shift τ is then such that 0<τ min <τ<τ max in the case of a pre-echo (FIG. 1), and τ min <τ<τ max <0 in the case of a post-echo (FIG. 2).
When the shift τ is not known a priori (the case of a recording on magnetic tape for example), the first phase of the process according to the invention consists in determining it. FIG. 3 shows a procedure which can be used for this purpose. The first two steps 10, 11 consist in transferring the signals of the first and second segments A, B to a time window N samples long over which their discrete Fourier transforms will be calculated in step 12. For optimal implementation by fast Fourier transform (FFT), it is expedient to take the length N in the form of a power of 2, for example N=2 a , with a=1+E log 2 (n f -n d +τ max -τ min )! where E .! denotes the integer part, so that N is greater than or equal to the lengths n f -n d and n f -n d +τ max -τ min of the segments A and B.
Thus, the signals u and v f illustrated in FIGS. 1 and 2 are defined in steps 10 and 11:
u(n)=x(n+n.sub.d)if 0≦n<n.sub.f -n.sub.d
u(n)=0if n.sub.f -n.sub.d ≦n<N
v.sub.f (n)=x(n+n.sub.d +τ.sub.min)if 0≦n<n.sub.f -n.sub.d +τ.sub.man -τ.sub.min
v.sub.f (n)=0if n.sub.f -n.sub.d +τ.sub.max -τ.sub.min ≦n<N
In step 12, a conventional FFT algorithm is used to calculate the discrete Fourier transforms of length N U(m) and V f (m) of the first and second segments A, B, that is to say, for 0≦m<N: ##EQU4##
The next step 13 is a thresholding operation in the frequency domain. In the frequency zones in which |U(m)| is relatively high (that is to say greater than the maximum level at which it would be expected to be found having regard to an envisageable maximum attenuation and to the level of the signal |V f (m)| which generated the echo), the useful signal is regarded as of greater energy than the echo. This frequency zone is therefore not to be taken into account in estimating the time shift since it is not necessarily representative of the echo signal. The operation carried out in step 13, which is comparable to a temporal filtering separating the echo from the useful signal, is then, for 0≦m<N: ##EQU5## where g max represents a predetermined coefficient equal to a maximum expected attenuation factor. A typical order of magnitude for the choice of g max corresponds to an attenuation of the order of -30 dB.
In step 14 the inverse discrete Fourier transform of the function W(m) of the frequency domain is performed in order to obtain a truncated correlation function c(n) between the first and second segments A, B. This correlation function is truncated in the sense that the function W(m) has been set to zero in step 13 for those frequency zones in which the signal of the first segment is regarded as too energetic relative to that of the second segment as the representative of an echo. The inverse discrete Fourier transform of length N can also be performed in step 14 by an FFT algorithm, so as to obtain, for 0≦n<N: ##EQU6##
In step 15, the integer n 1 is sought for which the modulus of the truncated correlation function c(n) is a maximum in the interval 0≦n<τ max -τ min . The function c(n) is generally real, and the maximum of its modulus generally corresponds to a positive real, so that it is possible to dispense with the calculation of the moduli |c(n)|. The actual time shift τ is then obtained in step 16 from the value of the integer n 1 obtained in step 15. With the conventions adopted in the example embodiment described, the shift τ is simply obtained by τ=n l +τ min .
This manner of estimating the time shift τ by means of a correlation calculation involving filtering in the frequency domain allows reliable estimation through the use of information available a priori about the maximum value g max of the attenuation factor.
When the time shift τ is known a priori, the estimation procedure illustrated by FIG. 3 may be dispensed with. This is the case for example for an audio frequency signal stemming from a recording on a ν rpm vinyl record: the shift τ can then be obtained in an elementary way via τ=E F e /(ν/60)!.
The second phase of the process according to the invention consists in determining a value g representative of the attenuation factor between the original O and its echo E pre or E post . Considered below, with reference to FIG. 4, is the case of a single value g independent of frequency to represent the attenuation factor.
The obtaining of the value g includes firstly a calculation of an estimate g of the attenuation factor (steps 20 to 22), and then a step 23 of overestimating the estimated attenuation factor. In step 23 it is thus possible to take g=μ.g, the predetermined coefficient μ corresponding for example to a gain of 3 or 5 dB.
Short-term Fourier transforms T samples long are used for estimation 20-22 of the attenuation factor g. An analysis window L samples long is defined, corresponding for example to a duration of the order of 40 ms: L=F e ×0.04. This duration can be adjusted depending on the type of audio signal processed. The analysis window is conventionally associated with a windowing function h(n), for example a rectangular function or alternatively a Hamming function such that:
h(n)= 1-cos(2πn/L)!/2for 0≦n<L
h(n)=0for n<0 and n≧L
The length T of the short-term Fourier transform can be taken equal to the length L of the analysis window. For optimal implementation via an FFT algorithm, it is expedient to take T in the form of a power of 2: T=2 b with b=1+E log 2 L!. From the value of T, an increment factor R is defined, equal to at most T, for example R=T/4.
The first step 20 of the estimation of the attenuation consists in temporally aligning the first segment A containing the echo E pre , E post with the corresponding portion of the second segment B containing the original O. A shifted signal v(n) is thus defined by:
v(n)=x(n+n.sub.d +τ)for 0≦n<n.sub.f-n.sub.d
τ being the previously determined value of the time shift (τ<0 for a pre-echo and τ>0 for a post-echo). It may be seen in FIGS. 1 and 2 that, in the signals u(n) and v(n), the echo and its original are temporally aligned.
The short-term Fourier transforms are calculated in step 21. More precisely, Q pairs of short-term Fourier transforms are calculated, Q being the integer defined by Q=1+E (n f -n d -T)/R!. Thus, for each integer q such that 0≦q<Q, the FFT algorithm makes it possible to obtain two functions U(q,k) and V(q,k) of the frequency domain (0≦k<T): ##EQU7##
The estimate g is then calculated in step 22 by applying formula (2). It is noted that this formula takes account only of the moduli of the short-term Fourier transforms U(q,k) and V(q,k).
If it is chosen to model the echo by a frequency-dependent attenuation factor, the flow chart of FIG. 4 can be modified in a straightforward way as regards steps 22 and 23. In the modified step 22, T estimates of the attenuation factor g(k) dependent on the frequency index k (0≦k<T) are calculated according to formula (1); and in the modified step 23, we take g(k)=μ.g(k) for 0≦k<T (it would also be possible to take a frequency-dependent overestimation factor μ).
The last phase of the process consists in the elimination proper of the echo, for example according to the nonlinear spectral subtraction procedure illustrated in FIG. 5.
Firstly the zone to be processed is defined; as previously, it may be the time interval n d ≦n<n f , but it may also be longer (possibly the whole recording if the attenuation factor and the time shift are regarded as not changing over time). This zone is delimited by the samples numbered n s and n e . The integer P is then defined by P=1+E n e -n s -T)/R!.
In step 30, P pairs of short-term Fourier transforms X(p,k), X.sub.τ (p,k), of length T, are calculated. For each integer P such that 0≦p<T, an FFT algorithm makes it possible to obtain the two functions of the frequency index k (0≦k<T): ##EQU8##
In step 31, a nonlinear transformation is applied to the short-term Fourier transform X(p,k) to obtain a corrected signal in the frequency domain Y(p,k), and this is done for each integer p such that 0≦p<P. This nonlinear transformation takes account, for the various values of the frequency index k, of the value g(k) or g representative of the attenuation factor and of the short-term Fourier transform X.sub.τ (p,k). More precisely, the corrected signal Y(p,k) is expressed in the form: ##EQU9## f being a positive, decreasing real function which introduces the nonlinearity. Such a transformation affects the modulus but not the argument of X(p,k). Step 31 represented in FIG. 5 corresponds to the case in which the attenuation factor is chosen to be independent of frequency (g(k)=g=Const) and to the choice f(z)=max{0, 1-z}. It will be noted that various other forms could be adopted for the function f, for example f(z)=(max{0, 1-z 2 }) 1/2 .
In step 32, P short-term components y(p,n) of a corrected signal are formed in the time domain by short-term inverse discrete Fourier transform of the corrected signals Y(p,k) in the frequency domain. For 0≦p<P, the FFT algorithm thus makes it possible to obtain the signal y(p,n) of time index n (0≦n<T): ##EQU10##
It is noted that steps 30 to 32, represented separately in FIG. 5, may be executed within one and the same loop over the integer p ranging from 0 to P-1. The operations corresponding to an iteration within this loop are illustrated in block diagram form in FIG. 6. Blocks 41 and 42 represent the short-term Fourier transforms (STFT) of the signal x(n+pR) and of the same signal shifted by τ samples at 40 (step 30 of FIG. 5 for one value of p). The multiplier block 43 applies the factor g to the modulus of Xτ(p,k), and the result is subtracted from the modulus of X(p,k) by the subtractor block 44. Block 46 represents the short-term inverse Fourier transform (ISTFT) applied to the corrected complex signal Y(p,k) whose argument is the same as that of X(p,k) and whose modulus is the greater, delivered by block 45, of 0 and the output from the subtractor block 46. Blocks 43 to 45 correspond to step 31 of FIG. 5 for one value of p, and block 46 to step 32.
In the final step 33, the corrected signal is formed in the time domain y(n) by weighted summation of its short-term components y(p,n). This is an overlap sum (overlap-add) which can be expressed, for T/2≦n<n e -n s -T/2, by: ##EQU11##
In this expression, w(n) denotes a synthesis windowing function of length L (that is to say zero outside the interval 0≦n<L), such as a rectangular or Hamming function.
The signal y(n+n s ) is the restored version of the signal x(n+n s ), in which the echo has been eliminated or at least substantially attenuated.
This echo attenuation procedure using a nonlinear short-term spectral subtraction technique has the advantage of working even if the shift τ is estimated only approximately, and even if the attenuation factor is overestimated. Overestimating g (step 23) makes it possible to further improve the attenuation.
Multiple pre-echoes or post-echoes may be observed in certain rare cases. For example, this is the case if one turn of a magnetic tape corrupts several neighbouring turns. Such a situation can be handled by executing several times in succession the routine corresponding to FIGS. 4 and 5, once for each individual shift. It is also possible to handle such a situation in a single iteration. In the example in which there are two shifts τ and 2τ, it is possible to obtain two values (or two sets of values) g.sub.τ and g 2 τ in steps 22, 23, provided that the short-term Fourier transforms V'(q,k) of the doubly shifted signal v'(n)=x(n+n d +2τ) were calculated on completion of steps 20 and 21. The corrected signal in the frequency domain Y(p,k) is then obtained, in the modified step 31, via ##EQU12## obtained in the modified step 30 and, for example, f'(z,z')=max{0, 1-z-z'}.
In the case in which the time shift is constant (for example for a 33 rpm record, but not for a magnetic tape), and in which the attenuation factor is also regarded as being constant over time, the entire signal can be processed without impairing the useful signal, that is to say n s and n e can correspond to the start and end of the complete recording. | For various values of an integer p, short-term discrete Fourier transforms X(p,k) and X.sub.τ (p,k) of the audio signal shifted by pR samples and of the audio signal shifted by pR+τ samples are respectively calculated, R denoting a predetermined integer and τ denoting a time shift between the echo and the portion of signal which gave rise to it, a corrected signal is calculated in the frequency domain by nonlinear transformation of X(p,k) taking account, for the various values of the frequency index k, of a value representative of an attenuation factor relating to the echo and of X.sub.τ (p,k), and a short-term component of a corrected signal is calculated in the time domain by short-term inverse Fourier transform of the corrected signal in the frequency domain. The corrected signal in the time domain is then formed by weighted summation of its short-term components. Application to the digital reprocessing of analog recordings. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to controlling a heating system. More particularly, the present invention relates to a method and apparatus for causing a heating system controller to change modes of operation.
There are many uses for industrial heating systems such as ovens, furnaces and boilers. Many such heating systems are sold by Original Equipment Manufacturers (OEM's). However, before OEM's can sell such heating systems, they are generally required to check out the operation of the heating system for any flaws. In order to check out the heating system, the OEM's cause the heating system controller to control operation of the heating system such that the heating system is run through a check-out sequence. During the check-out sequence, the heating system controller exercises all critical functions of the heating system so that check-out personnel can verify correct operation of the heating system and controller.
Some heating systems are controlled by a microprocessor. Therefore, in order to cause the heating system controller to perform the check-out sequence, a signal must be provided to the microprocessor so the microprocessor can enter a check-out mode.
In the past, there were several techniques for causing the microprocessor to enter the check-out mode. In one technique, the microprocessors used in heating system controllers had a designated pin for receiving the check-out mode signal. Upon receiving a check-out mode signal, the microprocessor would change from a normal operation mode to a check-out mode during which it cycled through the check-out sequence. In a second technique, heating system controllers had extra hardware added to facilitate the change between the normal mode of operation and the check-out mode. By manipulating inputs to this extra hardware, the OEM operator could command the microprocessor to enter the check-out mode.
However, as heating system controllers have become more complex, and as more control parameters are sensed by the heating system controller in controlling the heating system, the availability of pins on the microprocessor used in the heating system controller has declined. Also, the amount and complexity of the extra hardware required to accomplish the change between a normal operation mode and a check-out mode has increased. This has caused heating system controller hardware to grow to an undesirable size, or in some cases, has caused heating system controller manufacturers to increase the number of pins available on the microprocessor unit used in the heating system controller. For example, some heating system controllers now require a 40 pin microprocessor rather than a 28 pin processor. Both the increase in hardware and the increase in processor size are costly in terms of space and component cost.
For these reasons, there is a continuing need for the development of improved techniques for causing heating system controllers to change between a normal operation mode and a check-out mode. Further, there is a continuing need for developing these techniques which use no extra microprocessor pins and no extra hardware.
SUMMARY OF THE INVENTION
The present invention relates to a heating system controller suitable for controlling a heating system based on a plurality of sensed control signals representing control parameters. The heating system controller includes a first input, suitable for being coupled to provide a control signal, and sensing means coupled to the first input. The sensing means senses control signals, in a first pattern, a second pattern and a third pattern, where each pattern requires two successive time intervals to be sensed. The heating system controller also includes control means coupled to the sensing means for controlling the heating system based on the first pattern, the second pattern and the third pattern. The control means causes the controller to change modes when the third pattern is sensed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a heating system.
FIG. 2 is a more detailed diagram of a portion of the heating system shown in FIG. 1.
FIG. 3 is a plot of a control signal representing a control parameter in a first state.
FIG. 4 is a plot of the control signal shown in FIG. 3 at a controller input.
FIG. 5 is a plot of the control signal representing the parameter in a second state.
FIG. 6 is a plot of a mode signal.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a block diagram of heating system 10. Heating system 10 includes transformer 12, switches S1, S2, and S3, burner controller 14, control sensors 15 and burner 16. Burner controller 14 controls the operation of burner 16 based on control parameter signals received through switches such as switches S1, S2 and S3 as well as sensor signals received from control sensors 15. The control parameter signals represent control parameters which are sensed at burner 16 or which are operator selected parameters.
Burner 16 includes various components such as fuel valves 18, pilot/igniter 20 and inducer 22. Fuel valves 18 control the flow of fuel to burner 16. Pilot/igniter 20 controls ignition of the fuel provided to burner 16, and inducer 22 controls airflow in burner 16. Burner controller 14 controls fuel valves 18, pilot/igniter 20 and inducer 22 based on the control signals received through switches S1, S2 and S3 as well as control sensors 15.
Control sensors 15 include, for example, solid state analyzers which monitor such control parameters as the presence of a flame in burner 16, heat exchanger temperature, and pressure drop across the heat exchanger.
Switches S1, S2 and S3 are typically transducer controlled contacts set up to sense various parameters in heating system 10. For simplicity's sake, one switch contact is shown for each. More typically, however, switches S1, S2 and S3 could each be a string of series-connected contacts. When the sensed parameter corresponding to a given switch is in a first state, the switch is open. When the sensed parameter is in a second state, the corresponding switch is closed. Switch S1, for example, is a high temperature limit switch that opens if the heating system overheats (e.g. during a fan failure when the fuel valves are open). Otherwise, switch S1 is closed.
Switch S2, in this preferred embodiment, is a pressure switch which senses air pressure controlled by inducer 22. For example, when inducer 22 is ON and the air pressure flowing through the combustion chamber and heating system 10 is at a sufficient level, pressure switch S2 closes. On the other hand, when there is insufficient air pressure in the combustion chamber, switch S2 opens.
Switch S3, in this preferred embodiment, is a thermostat switch. Switch S3 closes on a call for heat; otherwise, switch S3 remains open. Therefore, by monitoring the state of switches S1, S2 and S3, burner controller 14 acquires needed information to control heating system 10. Based on the states of switches S1, S2 and S3, as well as the inputs from control sensors 15, burner controller 14 commands outputs to the various components of burner 16.
Line voltage L1 (which is typically an AC voltage) is coupled to transformer 12. Transformer 12 is a step-down transformer which steps down line voltage L1 to a 24 volt AC signal. This signal is applied to one side of switches S1, S2 and S3. Therefore, when switches S1, S2 or S3 are closed, the corresponding signal at the inputs to burner controller 14 is a time-varying signal. However, the inputs to burner controller 14 are resistor-coupled to a logic low state. Therefore, when switches S1, S2 or S3 are open, the corresponding signal at burner controller 14 is a logic low signal.
FIG. 2 is an enlarged portion of heating system 10 shown in FIG. 1. Input protection circuit 24 is shown coupled to switch S1. Input protection circuit 24 is typically coupled to each input to burner controller 14 to protect burner controller 14 from being damaged by voltage spikes caused by noise or static discharge. Input protection circuit 24 is either implemented externally to burner controller 14 or internally. Included in input protection circuit 24 are resistors R1 and R2 and diodes D1 and D2. FIG. 2 also shows switch terminals 26 and 27 and input terminal 28.
FIG. 3 is a plot of a control signal which typically appears at switches S1, S2 and S3. In this embodiment, FIG. 3 shows a plot of the signal appearing at switch terminal 26 shown in FIG. 2. When switch S1 is closed, control signal CS, shown in FIG. 3, is applied to input protection circuit 24. FIG. 4 shows the signal appearing at input terminal 28 of burner controller 14 when switch S1 is closed. The control signal CS appearing at input terminal 28 is substantially a square wave.
Normal Operation Mode
During normal operation, burner controller 14 samples the signal appearing at input terminal 28 once each half cycle. By doing this, burner controller 14 determines the state of corresponding switch S1 and hence, the state of the sensed control parameter.
For example, burner controller 14 samples the signal appearing at input terminal 28 at approximately the midpoint of time period t1 to verify that control signal CS is above a threshold voltage V t . Then, at approximately the midpoint of time period t2, burner controller 14 again samples control signal CS to verify that it is below a threshold voltage V t . That control signal CS has changed states from time period t1 to time period t2 with respect to threshold voltage V t indicates to burner controller 14 that switch S1 is closed. Therefore, in this preferred embodiment, burner controller 14 determines that the system is operating below a high limit temperature.
FIG. 5, on the other hand, shows control signal CS appearing at input terminal 28 which represents that the heating system is operating above the high limit temperature. When switch S1 is open, control signal CS is pulled down to a logic low level below the threshold voltage V t . Therefore, during the two successive time intervals t1 and t2, control signal CS remains at a logic low level. By monitoring input terminal 28 at approximately the midpoint of time periods t1 and t2, burner controller 14 determines that switch S1 is open and, hence, that the system has overheated. Burner controller 14 monitors switches S1, S2 and S3 and determines the state of various sensor parameters in this way. Based on that information, burner controller 14 controls burner 16 accordingly.
In essence, during a normal operation mode, signals appearing at the inputs to burner controller 14 corresponding to switches S1, S2 and S3, represent control parameters which can be in one of two states. Where the heating system is operating below the high limit temperature, control signal CS representing the state of high temperature limit switch S1, which is provided at control input 28, is essentially a square wave. On the other hand, where the system has overheated and high temperature limit switch S1 is open, control signal CS provided at control input 28, is essentially a static signal which remains at a logic low level. To determine which state the particular control parameter is in, burner controller 14 must monitor the control inputs (such as control input 28) during two successive time intervals (in this case intervals t1 and t2).
Check-out Mode
Before heating system 10 is ready for normal operation, it must be checked out. This requires burner controller 14 to enter a check-out mode where it operates heating system 10 in a check-out sequence. In order to enter the check-out mode, upon power-up of heating system 10, an operator applies mode signal MS (shown in FIG. 6) to switch terminal 27 of switch S1 (shown in FIG. 2). As described earlier, burner controller 14 monitors input terminal 28 at a point near the middle of time period t1 and at a point near the middle of time period t2. Upon sensing that the signal at terminal 28 is a logic high level during both of the two successive time periods t1 and t2, burner controller 14 enters the check-out mode.
In this embodiment, the check-out mode includes a speed-up mode where a normal operation sequence is speeded up to save check-out time. During the speed-up sequence, burner controller 14 effectively cycles through and exercises all of the essential functions in heating system 10. For example, one of the functions exercised is the ignition function. A typical ignition sequence during normal operation is as follows:
______________________________________30 seconds of prepurge during which inducer 22 is turned on and the combustion chamber is ventilated to remove any fumes from unburned fuel.36 seconds of hot surface igniter (HSI) warm- up during which a hot surface igniter is activated and brought to ignition temperature.6 seconds of trial for ignition during which fuel is supplied to the hot surface igniter and ignition is attempted.30 seconds of fan on delay time.102 seconds = Total Ignition Sequence Time during normal operation.______________________________________
However, it is undesirable for the equipment manufacturer to be required to wait 102 seconds since the heating system is only being checked-out and not actually operating a heating system in a normal operation mode. Therefore, during check-out burner controller 14 is provided with a check-out signal, which causes burner controller 14 to exit the normal operation mode and enter a check-out mode. During the check-out mode, in this preferred embodiment, burner controller 14 cycles through the ignition sequence as follows:
5 seconds of prepurge.
12 seconds of HSI warm-up.
6 seconds of trial for ignition.
5 seconds of fan on delay time.
This reduces the ignition check-out sequence time from 102 seconds to 28 seconds. Even though the sequence time is reduced, the manufacturer is still able to check out all critical ignition functions.
Burner controller 14 is programmed so that it only recognizes mode signal MS upon power-up of heating system 10. Therefore, if, during normal operation, switch terminal 27 is somehow short-circuited to a logic high voltage level, controller 14 detects a heating system fault rather than a valid mode signal. This allows the mode selection technique of the present invention to be used safely by both OEM check-out personnel as well as service or other maintenance personnel. Also, by utilizing the input corresponding to switch S1 not only to indicate the state of the high temperature limit switch, but also as a mode input, burner controller 14 needs no extra pins or external hardware-implemented logic to accommodate a test mode signal input.
Also, it should be noted that input terminal 28 is not uniquely suited to operate as a mode signal input. The mode signal MS (in this preferred embodiment, a logic high signal) could be applied to any input to burner controller 14 where the signal appearing at the input during normal operation represents two states of a control parameter where one state is represented by a first signal pattern (in this case, an alternating signal over two successive time periods which changes states between the two consecutive time periods t1 and t2) and where the second state is represented by a second signal pattern (in this case, a logic low level) for the two consecutive time periods t1 and t2. It should also be noted that, upon receiving the mode signal MS, burner controller 14 could be programmed to enter any type of check-out mode such as a mode where the manufacturer simply tests fan speeds, proves pressure switches or tests air flow capacity of inducer 22. The speed-up mode is merely one preferred alternative.
Conclusion
In the present invention, burner controller 14 in heating system 10 is configured to recognize three signal patterns over two successive time intervals t1 and t2. The first signal pattern is a time varying signal, substantially a square wave. Control signal CS is monitored by burner controller 14 during each of the two successive time intervals t1 and t2 and moves between a first logic level (above threshold level V t to a second logic level (below threshold level V t ). When burner controller 14 senses this first signal pattern, burner controller 14 determines that switch S1 is closed and that the particular control parameter being sensed (in this case heating system temperature) is in a first state (below the high temperature limit).
The second pattern, in this preferred embodiment, is substantially a steady state signal at a logic low level for the two successive time intervals t1 and t2. Upon sensing the second pattern, burner controller 14 determines that switch S1 is open and the particular control parameter being sensed is in a second state (above the high temperature limit).
However, burner controller 14 is also configured for sensing a third signal pattern. This is the signal pattern of mode signal MS shown in FIG. 6. When burner controller 14 senses signal MS, it switches modes of operation. Since burner controller 14 is only configured to recognize the third signal pattern upon power-up, or within a predetermined period after power-up, burner controller 14 is prevented from switching modes of operation during a normal heating cycle.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | A heating system controller is suitable for controlling a heating system based on a plurality of sensed control signals representing control parameters. The heating system controller has a first input suitable for being coupled to provide a control signal. The heating system controller also includes a sensor, coupled to the first input, for sensing control signals at the first input, the control signals having a first pattern, a second pattern, or a third pattern detected over at least two successive time periods. The heating system controller includes a control mechanism, coupled to the sensor for controlling the heating system based on the first, second and third patterns. The control mechanism causes the controller to change modes when the third pattern is sensed. | 5 |
[0001] This application claims priority from provisional application Ser. No. 60/207,082, filed May 25, 2000, which is incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates generally to a surgical instrument for puncturing a body cavity. More particularly, the present disclosure relates to a trocar assembly for puncturing a body cavity having a hand grip including a cushioned slip-resistant portion.
[0004] 2. Background of Related Art
[0005] Surgical instrumentation for puncturing body cavities, i.e., trocar assemblies are well known in the art. Typically, a trocar assembly includes an obturator having a sharpened tip at one end for piercing the body cavity and a hand grip portion mounted on the other end of the obturator which the surgeon grasps in the palm of his hand. The hand grip portion includes a plunger which engages the other end of the obturator and can be pressed with the palm of the hand to force the sharpened end of the obturator through the body cavity wall. Often, during endoscopic surgical procedures, multiple punctures through the body cavities are required.
[0006] In known trocar assemblies, the hand grip portion of the trocar assembly is formed from a hard plastic material and considerable force may be required to thrust the obturator through the body cavity wall. This force typically ranges from about 2 lbs. to about 20 lbs. and may be even higher, especially when operating on obese individuals. Such a force may cause discomfort to and eventually bruising of the surgeon's hand. Moreover, during most surgical procedures, blood and other body fluids collect on a surgeon's hands or gloves making it difficult for the surgeon to grip the hand grip portion of the trocar assembly.
[0007] Accordingly, a need exists for an improved trocar assembly which can be actuated by a surgeon without causing the surgeon discomfort and which can be securely gripped by a surgeon even in the presence of body fluids.
SUMMARY
[0008] In accordance with the present disclosure, a trocar assembly is provided which includes an obturator having a sharpened tip at one end and a hand grip secured to the other end. The hand grip includes a cushioned slip resistant member. The cushioned member is preferably formed from a thermoplastic elastomer, e.g., Versaflex™ or Santaprene™, and over-molded onto the hand grip of the trocar assembly. Alternately, the cushioned member may be formed of other cushioned or pliant materials, e.g., elastomeric or synthetic materials, including isoprenes or nitrile or silicon containing material, etc. Moreover, the grip member can be fastened to the grip portion using other known fastening techniques, e.g., physical, chemical or mechanical, including adhesives, welding, screws, etc.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Various preferred embodiments of the presently disclosed trocar assembly are described herein with reference to the drawings, wherein:
[0010] [0010]FIG. 1 is a side cross-sectional view of the presently disclosed trocar assembly; and
[0011] [0011]FIG. 2 is a perspective view of one preferred embodiment of the presently disclosed trocar assembly positioned within a valved cannula assembly.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0012] Preferred embodiments of the presently disclosed trocar assembly will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views.
[0013] [0013]FIG. 1 illustrates a trocar assembly including an obturator 6 defining a longitudinal axis and having first and second ends. FIG. 2 illustrates the trocar assembly in combination with a cannula assembly 30 . A sharpened tip 8 is mounted on the first end of the obturator 6 . Tip 8 functions to penetrate or pierce a body cavity. A hand grip 4 is mounted on the second end of the obturator. Hand grip 4 is preferably formed from molded thermoplastic housing half-sections which are secured together to define a cavity 10 for receiving the second end of obturator 6 . Alternately, other materials may be suitable for use, including other plastics, composites, surgical grade metals, etc.
[0014] A cushioned grip member 22 is secured to at least one pressure contact region of hand grip 4 . The pressure contact regions of the hand grip include those areas of hand grip 4 to which a surgeon must grasp or apply pressure to during manipulation of the trocar assembly or insertion of obturator 6 through tissue into a body cavity. In a preferred embodiment, cushioned grip member 22 is formed from a thermoplastic elastomer or elastomer blend, such a Versaflex™ or Santoprene™, and is over-molded onto hand grip 4 . A preferred thermoplastic elastomer is OM1040-X Versaflex™. Alternately, the use of different cushioned or pliant materials is envisioned, as is the use of different techniques for fastening grip member 22 onto hand grip 4 . For example, grip member 22 may be formed from other pliant materials, including plastics, elastomers, synthetics, etc. Moreover, grip member 22 may be fastened to hand grip 4 using other fastening techniques, e.g., chemical, physical, or mechanical, including adhesives, screws, welding, interengaging members, bonding, fusing, coating, dipping, spraying, etc.
[0015] The use of a cushioned portion formed from a thermoplastic or an elastomeric material on the pressure contact regions of the handle assembly cushions the impact on a surgeon's hand during operation of the surgical instrument. Preferably, the cushioned portion is formed from a material having slip resistant properties which adhere well to the gloves worn by a surgeon, even in the presence of bodily fluids, to improve a surgeon's grip on the surgical instrument. In addition, the cushioned material may include a textured, roughened or ridged surface to enhance or provide the slip-resistant surface. The hardness of the cushioning material employed will vary depending on a particular surgical instrument and its application. The pressure required to actuate a particular instrument should be considered when choosing the material for forming the cushioned portion of the instrument. For example, a softer material may be more suitable for use with instruments requiring higher actuation pressures. Conversely, a harder material may be suitable for use in surgical instruments requiring smaller actuation pressures. The durometer of the cushioning material can be from about 10 to about 80, but is preferably between about 20 to about 50, and more preferably about 40.
[0016] Other factors should also be considered prior to selecting the cushioning material. These include whether the instrument is disposable or reusable and will be subjected to sterilization or other cleaning processes. If the instrument is reusable, a cushioning material having heat resistant properties should be used. In the alternative, it is contemplated that the cushioning member can be removable such that it could be removed from the surgical instrument prior to the sterilization and/or cleaning process. For example, the cushioning member could be provided as a removable flexible sleeve.
[0017] It will be understood that various modifications may be made to the embodiments disclosed herein. For example, it is envisioned that other pliant or cushion materials may be used to achieve a cushioning effect similar to that disclosed above. Moreover, the above described cushioned portion may be provided on other hand operated surgical devices. Therefore, the above description should not be construed as limiting, but hereby as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. | A trocar assembly is provided which includes an obturator having a sharpened tip supported on one end thereof and a hand grip supported on an opposite end thereof. A cushioned grip member is supported on the hand grip. The cushioned grip member includes a slip resistant surface and is positioned on pressure contact regions of the hand grip. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the priority of U.S. Provisional Patent Application Ser. No. 60/849,241 filed on Oct. 4, 2006, which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
This invention relates to a motor vehicle body assembly, and more particularly to the formation and welding of motor vehicle body sub-assemblies with unrestricted model mix and quick changeover between models.
BACKGROUND OF THE INVENTION
A typical motor vehicle assembly plan is set up to produce several different body styles or models on the same assembly line. Each body style requires unique sub-assemblies and each sub-assembly requires unique end effector tooling. In the prior art, in order to change end effector tooling to effect a body style changeover at a sub-assembly location from a first model to a second model, robots are utilized to move the end effecter tooling corresponding to the first model from the sub-assembly location to a suitable storage location, all of the energy feeds for the tooling are decoupled, the robot picks up new tooling corresponding to the second model, the energy feeds of the new tooling are coupled to the robot, and the robot moves the new tooling to the sub-assembly location. This entire procedure is time consuming and inefficient especially in a random model mix assembly plant where the body style is frequently changed.
SUMMARY OF THE INVENTION
This invention is directed to the provision of a method and apparatus for providing motor vehicle sub-assemblies for a plurality of motor vehicle models with unrestricted model mix and quick changeover between models.
According to an important feature of the invention apparatus, the apparatus includes a turret having a central axis and first and second tooling faces spaced circumferentially about the central axis; unique tooling fixtures on the respective first and second faces for receiving unique work piece components corresponding respectively to the first and second motor vehicle body styles; and mounting structure mounting the turret for movement along a linear path between first and second work stations and for rotation about its central axis to selectively present a respective face and its unique tooling to a work station for receipt of unique work piece components corresponding to a respective motor vehicle body style.
According to a further feature of the invention apparatus, the first work station is defined on one side of the path; the second work station is defined on an opposite side of the path; and the apparatus further includes means operative to rotate the turret through 180° as the turret moves between the first and second work stations whereby to move a tooling face from a position presenting on one side of the path at the first work station to a position presenting on an opposite side of the path at the second work station. In one disclosed embodiment of the invention, the first work station comprises a loading station and the second work station comprises a welding station.
According to a further feature of the invention apparatus, the mounting structure includes a track, a carriage mounted for linear movement along the track, and journal structure on the carriage mounting the turret on the carriage for rotation about its central axis.
According to a further feature of the invention apparatus, the turret comprises a first turret and the apparatus further includes a second turret rotatably mounted on the carriage in longitudinally spaced relation to the first turret and including first and second tooling faces spaced circumferentially with respect to the rotational axis of the second turret and unique tooling fixtures on the respective first and second tooling faces of the second turret for receiving unique work piece components corresponding respectively to the first and second motor vehicle body style.
According to a further feature of the invention apparatus, the apparatus further includes power means operative to rotate each turret through 180° as the carriage is moved from its first position to its second position.
According to a further feature of the invention apparatus, the power means comprises a carriage motor assembly operative to move the carriage along the path between the first and second positions and turret motor assemblies mounted on the carriage and operative to rotate the turrets on the carriage.
According to a further feature of the invention apparatus, each turret includes a tower structure defining the first and second faces and a base ring gear positioned on the carriage and each turret motor assembly includes a motor driving a pinion engaging the ring gear of the respective turret.
According to a further feature of the invention apparatus, the track includes a plurality of longitudinally spaced rollers; the carriage is rollably mounted on the rollers; and the carriage motor assembly includes a motor driving the rollers whereby to propel the carriage along the track.
According to a further feature of the invention apparatus, the apparatus further includes a latch assembly mounted on the carriage and operative to selectively preclude sliding movement of the carriage along the track and rotation of the turrets on the carriage.
According to an important feature of the invention methodology, a turret is provided having a central axis and first and second tooling faces spaced circumferentially about the central axis; unique tooling fixtures are provided on the respective first and second faces for receiving unique work piece components corresponding respectively to first and second motor vehicle body styles; the turret is moved along a linear path between first and second work stations; and the turret is rotated about its central axis to selectively present a respective face and its unique tooling to a work station for receipt of unique work piece components corresponding to a respective motor vehicle body style.
According to a further feature of the invention methodology, the first work station is defined on one side of the path; the second work station is defined on an opposite side of the path; and the turret is rotated 180° as the turret moves between the first and second work stations whereby to move a tooling face from a position presenting on one side of the path at the first work station to a position presenting on an opposite side of the path at the second work station.
According to a further feature of the invention methodology, a track is provided extending between the first and second work station; a carriage is provided mounted for linear movement along the track; and journal means are provided on the carriage mounting the turret on the carriage for rotation about its central axis.
According to a further feature of the invention methodology, the turret comprises a first turret and the method includes the further steps of providing a second turret rotatably mounted on the carriage in longitudinally spaced relation to the first turret and including first and second tooling faces spaced circumferentially with respect to the rotational axis of the second turret and unique tooling fixtures on the respective first and second tooling faces of the second turret for receiving unique work piece components corresponding respectively to the first and second motor vehicle body style.
According to a further feature of the invention methodology, a path is provided having a load side and an unload side; a carriage is provided mounted for longitudinal movement along the path between a first position and a second position; first and second turrets are provided rotatably mounted on the carriage at longitudinally spaced locations on the carriage; first and second circumferentially spaced individual tooling faces are provided on each turret; unique tooling fixtures are provided on the respective first and second turret tooling faces for receiving unique work piece components corresponding to first and second motor vehicle body styles; the carriage is positioned in its first position with the first turret positioned with a first face thereof facing the load side of the path and the second turret positioned with the first face thereof facing the unload side of the path and work piece components corresponding to the first motor vehicle body style positioned on the first face thereof; work piece components corresponding to the first motor vehicle body style are loaded onto the tooling fixtures on the first side of the first turret while welding the work piece components corresponding to the first motor vehicle body style positioned on the first side of the second turret and thereafter removing the welded together work piece components from the second turret for further processing; and the carriage is thereafter moved to its second position while rotating the first turret to position the first face thereof facing the unload side of the path and rotating the second turret to position the first face thereof facing the load side of the path.
According to a further feature of the invention methodology, the method includes the further steps of, with the carriage in its second position, loading work piece components corresponding to the first motor vehicle body style onto the tooling fixtures on the first face of the second turret while welding the work piece components corresponding to the first motor vehicle body style positioned on the first face of the first turret and thereafter removing the welded together work piece components from the first turret for further processing.
According to a further feature of the invention methodology, the invention includes the further steps of, when a changeover to the second motor vehicle body style is required, rotating the first and second turrets to bring the second face of each carriage into the position corresponding to the position of the first face prior to the changeover.
According to a further feature of the invention methodology, each turret includes a third face circumferentially spaced from the first and second faces and unique tooling fixtures corresponding to a third motor vehicle body style are positioned on the third faces of the turrets whereby to allow changeover between the first and third body styles and the second and third body styles in addition to the changeover between the first and second body styles.
According to a further feature of the invention methodology, each turret further includes a fourth face circumferentially spaced from the first, second and third faces and unique tooling fixtures corresponding to a fourth motor vehicle body style are positioned on the fourth faces of the turrets whereby to allow changeover between the first and fourth body styles, the second and fourth body styles and the third and fourth body styles in addition to the changeovers between the first and second body styles, the first and third body styles and the second and third body styles.
Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
FIG. 1 is a schematic plan view of an automotive body assembly installation including an automotive body subassembly apparatus according to the invention;
FIG. 2 is a perspective view of the automotive body subassembly apparatus;
FIG. 3 is a fragmentary detail view of a power roll assembly utilized in the body subassembly apparatus;
FIG. 4 is a perspective view of a shuttle assembly utilized in the body subassembly apparatus;
FIGS. 5 and 6 are detail views of a latch mechanism utilized in the shuttle assembly;
FIG. 7 is an exploded perspective view showing a carriage and a track structure utilized in the body subassembly apparatus;
FIG. 8 is a perspective view of a roller turret guide assembly; and
FIG. 9 is a cross-sectional view of the power roll assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The automobile body assembly installation seen in FIG. 1 is especially suited for use in fabricating automotive sub-assemblies such as doors, hoods, deck lids, cowls, etc.
An important part of the installation of FIG. 1 comprises an automotive body subassembly apparatus 10 , two of which are seen in FIG. 1 .
Each body subassembly apparatus 10 , broadly considered, includes a track structure 12 and a shuttle assembly 14 .
Track structure 12 includes a plurality of transverse longitudinally spaced cross members 16 supported at their opposite ends by foot pads 18 suitably secured to a floor surface 20 ; a central longitudinal spine member 22 interconnecting the cross members, a pair of tubular rail members 24 extending along opposite end edges of the cross members; and a power roll assembly 26 .
Power roll assembly 26 includes a plurality of rollers 28 , a plurality of drive elements 30 , and a motor assembly 32 .
Each roller 28 is journaled within a respective rail member 24 by a shaft 34 with an upper portion of the roller projecting through a window 24 a in the rail member to position the upper peripheral face 28 a of the roller above the upper face of the rail member. A series of rollers 28 are positioned in longitudinally spaced relation in each rail member 24 .
Drive elements 30 may comprise belts or chains driving the rollers 28 via pulleys or sprockets 36 fixedly secured on the respective shafts 34 .
Motor assembly 32 includes an electric motor 38 driving an output shaft 40 through a reduction gear mechanism 42 . Shaft 40 extends through rail members 24 , terminates in free end 40 a , and serves to drive a central roller 28 in each of the series of the rollers in the respective rail members, whereby powered rotation of shaft 40 acts via drive elements 30 to rotate all of the rollers in both rail members in a direction corresponding to the direction of rotation of shaft 40 .
Shuttle assembly 14 includes a pallet or carriage 46 , a pair of turrets 48 , a pair of turret motor assemblies 50 , and a latch assembly 52 .
Carriage 46 is sized to slide along track structure 12 on rollers 28 so as to effectively shuttle back and forth along the track structure.
Carriage 46 includes a pair of tubular rail members 54 , laterally spaced by a distance corresponding to the lateral spacing of the rail members 24 so as to enable the rail members 54 to move rollably along the rollers 28 in the respective rail members 24 ; end cross members 56 ; central cross members 58 ; intermediate cross members 60 ; X structures 62 positioned between each respective set of end members 56 and intermediate members 60 ; turret roller guide structures 64 ; a guide plate 66 underlying central cross members 58 ; a motor mount structure 68 positioned centrally on each end cross member 56 ; and a latch guide structure 70 centrally positioned on each intermediate cross member 60 .
Each roller guide structure 64 includes a base plate 64 a , spaced upstanding lugs 64 b , and a roller 72 journaled between the spaced lugs. A roller guide structure 64 is fixedly positioned on each distal end of each X structure 62 at the intersections of the guide rails 54 , end rails 56 , and intermediate rails 60 with the rotational axes of the rollers 72 on each X structure 62 intersecting at the center 62 a of the X structure.
Each motor mount structure 68 includes a plurality of stacked plates including an upper lug plate 68 a.
Each latch guide structure 70 includes a base portion 70 a secured to a respective intermediate cross-member 60 and a pair of spaced lugs 70 b.
Each turret 48 includes a base ring gear 74 and a tower structure 76 fixedly secured to an upper face of the ring gear.
Tower structure 76 has a truncated pyramidal configuration and includes an upper rectangular frame structure 76 a , a lower lattice work base structure 76 b , and a plurality of inwardly angled upstanding members 76 c extending between the base structure 76 b and the upper frame structure 76 a . The described structure will be seen to define four upwardly angled rectangular turret faces A, B, C and D, with each face defined between a pair of spaced upright members 76 c.
Each turret is mounted at the center 62 a of a respective X structure 62 via a suitable bearing structure 80 journaling a central hub portion 74 a of the respective ring gear with the underface of the rim 74 b of the ring gear rollably guiding on the rollers 72 of the respective turret guide structures 64 whereby to allow free rotation of the turret on the carriage about the axis of the bearing 80 .
Each turret motor assembly 50 comprises an electric motor 82 , a reduction gearing 84 , an output shaft 86 , and a pinion gear 88 driven by the output shaft. The motor 50 is mounted on the end of a guide rail 54 with the reduction gearing 84 mounted beneath a respective lug plate 68 a with the output shaft extending upwardly thorough the lug plate to position the pinion gear 88 above the lug plate face in meshing engagement with the gear teeth 76 c of the respective ring gear of the respective turret whereby actuation of the motor 50 has the effect of rotating the respective turret about the axis of its central bearing structure 80 .
Latch assembly 52 includes an electric motor 90 , reduction gearing 92 , an output shaft 94 , a three pronged lever structure 96 driven by shaft 94 , turret latch assemblies 98 , and a carriage latch assembly 100 .
Motor 90 and reduction gearing 92 are suitably mounted on central carriage cross-members 58 .
Each turret latch assembly 98 includes a latch finger 102 pivotally mounted intermediate its ends on a pivot shaft 103 extending between the lugs 70 b of a respective latch structure 70 , and a link 104 pivotally mounted at an inboard end thereof to a prong 96 a of the lever structure 96 and pivotally mounted at its outboard end to the lower end of a respective finger 102 .
Carriage latch assembly 100 includes a plunger 106 and a link 108 . Plunger 106 is received in a bushing 110 in plate 66 and coacts at its lower end 106 a with an aperture 22 a in track structure central spine member 22 . Link 108 is pivotally connected at its lower end to the upper end of plunger 106 and pivotally connected at its upper end to prong 96 b of the lever structure 96 .
Latch assembly 52 is arranged such that with the latch elements in the position seen in FIG. 4 , and in the solid line position of FIG. 5 , the lower end 106 a of plunger 106 engages aperture 22 a in spine member 22 to preclude sliding movement of the shuttle assembly on the track structure and fingers 102 are positioned between rollers 112 down standing from the rim 74 b of each ring gear 74 to preclude rotation of the turrets relative to the carriage 46 .
When the latch lever 96 is rotated to the dash line position seen in FIG. 5 by suitable energization of motor 90 , fingers 102 are rotated to a position clear of the rollers 112 , whereby to allow free rotation of the turrets on the carriage, and the lower end 106 a of plunger 106 is withdrawn from aperture 22 a to allow sliding movement of the shuttle assembly on the track structure.
In overview, energization of motor 38 operates via rollers 28 and drive elements 30 to move the shuttle assembly longitudinally along the track structure, and energization of motors 82 acts via pinions 88 and ring gears 74 to rotate the turrets with respect to the carriage with the reciprocal or rotational movement selectively precluded or allowed by selective actuation of latch assembly 52 . The reciprocal movement of the carriage along the track structure is facilitated by the rolling engagement of the side rails 54 of the carriage on the rollers 28 with lateral displacement of the carriage relative to the track structure precluded by guide rollers 113 suitably engaging the side rails of the carriage, and the rotation of the turrets on the carriage is facilitated by the bearing structures 80 and by the rolling engagement of the underface of the rim of the respective ring gear with the rollers 72 . The amount of reciprocal movement imparted to the shuttle assembly as well as the amount of rotary movement imparted to the turrets is, in each case, controlled in known manner by encoder devices associated with the respective motors. Pneumatic, hydraulic, and electric energy requirements are delivered to the shuttle assembly by flexible conduits seen schematically at 114 and it will of course be understood that a suitable control mechanism will be provided to control the movements of the various components of the body subassembly apparatus 10 including the selective control of latch assembly 52 to selectively preclude and allow linear movement of the pallet and rotational movement of the turrets.
The operation of the body subassembly apparatus 10 in the context of the body assembly installation seen in FIG. 1 will now be described with attention first to the body subassembly apparatus 10 seen on the left side of FIG. 1 .
The following description is on the assumption that the subassembly apparatus 10 will be utilized to perform the subassembly of a vehicle door and it will be understood that the four sides A, B, C and D of each turret have previously been outfitted with schematically illustrated tooling fixtures 116 (including clamps, risers, etc.) that are peculiar to a specific model of motor vehicle. Specifically, side A of each turret would be outfitted with fixtures 116 A specific to the assembly of a door for a Model A vehicle; side B of each turret would be equipped with fixtures 116 B specific to the assembly of a door for a Model B vehicle; side C of each turret would be equipped with fixtures 116 C specific to the assembly of a door for a Model C vehicle; and side D of each turret would be equipped with fixtures 116 D specific to the assembly of the door of a Model D vehicle. The Model A, B, C and D doors may comprise different doors for different body styles of the same basic vehicle and/or may comprise doors for totally distinct vehicles.
Assuming that it is desired initially to fabricate a door for a Model A vehicle, and with the shuttle assembly in the left position (as viewed in FIG. 2 ) with the A face of the left turret facing the operator “O” and the A face of the right turret facing weld robots WR 1 and WR 2 , the operator “O” positioned at a load station LS 1 for the left hand turret would load Model A door components from bins I, II and III onto the A Model tooling fixtures 116 A positioned on the “A” face of the left turret whereafter the shuttle assembly would be moved to the right (as viewed in FIG. 2 ) to move the right turret to the right end of the track assembly to a load station LS 2 for the right hand turret while moving the left turret to a weld/unload station WU at the center of the track assembly while simultaneously rotating the left turret through 180° so that the “A” face of the left hand turret as it arrives at the weld/unload station WU now faces weld robots WR 1 and WR 2 . Simultaneously, as the right turret moves to the right end of the track assembly the right turret is rotated through 180° to present the “A” face of the turret assembly to the operator “O” who has now moved to load station LS 2 so that, as robots WR 1 and WR 2 weld the “A” Model components positioned on the “A” face of the left hand turret, the operator “O” may load “A” Model components from bins I, II and III onto the “A” model tooling fixtures 116 A positioned on the “A” face of the right hand turret whereupon, following the simultaneous loading of the “A” face of the right hand turret and welding of the components on the “A” face of the left hand turret, the welded door may be unloaded from the “A” face of the left hand turret by a transfer robot TR 1 positioned proximate weld/unload station WU and the shuttle assembly may be moved to the left to return the left hand turret to load station LS 1 and move the right hand turret to the weld/unload station WU while simultaneously rotating each turret through 180° so that as the left turret arrives at the load station LS 1 the “A” face is again presented to the operator “O” (who has now returned to his initial position at LS 1 ) and as the right turret arrives at the weld/unload station WU the “A” face is presented to the weld robots. This simultaneous shuttling, rotating, and unloading procedure is repeated in so long as the plant manufacturing requirements are calling for the manufacture of “A” Model doors.
However, in a random mix assembly process in a plant capable of manufacturing several vehicle models, it is frequently necessary to effect a change-over in the subassembly procedures so as to provide door assemblies for a different model, such for example as a Model “B” vehicle. With the invention subassembly apparatus, this change-over is quickly and efficiently accomplished by simply rotating the turrets, utilizing motor assemblies 50 , through 90° whereby to present the “B” face of each turret with the 116 B tooling fixtures to the operator as the left turret is loaded at load station LS 1 and the right turret is loaded at load station LS 2 . Once the turrets have been readjusted by a simple 90° rotation to accommodate a Model “B” subassembly procedure, the previously described loading and welding procedure can be undertaken and continued so long as Model “B” door assemblies are called for. If and when Model “C” door assemblies are required, a further 90° adjusting rotation of the turret assemblies is performed and if and when Model “D” door sub-assemblies are required, a further 90° rotation of the turret assemblies is performed. If it is desired to change from an “A” Model door assembly to a “C” Model door assembly or from a “B” Model door assembly to a “D” Model door assembly this change-over is quickly and efficiently accomplished by a 180° rotation of the turrets.
In each case, after the robots WR 1 and WR 2 have completed their welding operation on the respective door components, the transfer robot TR 1 is utilized to unload the welded door assembly from the turret and move it to a nest N 1 where further welding on the door assembly may be provided by a weld robot WR 3 located at a respot station, whereafter a transfer robot TR 2 may be utilized to move the respotted door assembly to a further nest N 2 whereafter a further transfer robot TR 3 may be utilized to access a further door assembly part (such for example as an impact beam) from a bin IV, add it to the previously welded door assembly, and transfer the door assembly with the added impact beam to a further transfer robot TR 4 mounted on a table “T” for reciprocal movement between left and right positions (or upper and lower as viewed in FIG. 1 ) so as to coact with a further body subassembly apparatus 10 seen on the right hand side of FIG. 1 . In this case the transfer robot TR 4 takes the place of the manual operator “O” associated with the left hand body subassembly apparatus 10 and moves back and forth on table “T” between left and right positions to selectively load the left hand turret of the right hand apparatus 10 and the right hand turret of the right hand apparatus 10 in the manual manner previously described with respect to the left hand apparatus 10 with the shuttle assembly moving back and forth between left and right load stations as previously described with respect to the manual operator and with the turrets rotating through 180° as the turrets undergo their shuttling movement so as to present components loaded for example on an “A” face of a turret by the robot TR 4 to further weld robots WR 4 and WR 5 located at a central weld/unload station whereafter the welded door assembly may be unloaded by a transfer robot TR 5 for movement to a further respot station where further weld robots may perform further welding on the door assembly.
As with the left hand manual load body subassembly apparatus 10 , the turrets of the right hand robot load body subassembly apparatus 10 may be readily rotated through either 90° or 180° to quickly provide a change-over between a Model “A”, Model “B”, Model “C” or Model “D” random door requirement with the model change-over performed at the right hand robot load apparatus 10 of course corresponding in each case to the model change-over performed at the left hand manual load apparatus 10 .
The invention body subassembly apparatus will be seen to provide a quick and efficient means of effecting a model change-over. Specifically, model change-over is accomplished with the invention apparatus simply by rotating the turrets through the required angular amount, as compared to prior art installations where it is required for the robot to pick up the tooling at the sub-assembly location, transport the tooling to a suitable storage location, decouple all of the energy feeds for the tooling, and then, in a separate time consuming operation, pick up a new end effecter tooling corresponding to the new model requirements, couple the energy needs of the new tooling to the robot, and transport the tooling to the sub-assembly location. The total time required to simply rotate the turrets of the invention apparatus is a fraction of the time required in the prior art installation to deposit and decouple the old end effecter tooling at a suitable storage location and pick up and couple a new end effecter tooling to accomplish the proper subassembly for the new model. The overall effect is that the cost of the machinery required to provide ready and efficient subassembly of various vehicle models on a random basis is significantly reduced both in terms of the cost of the initial equipment, the maintenance required on the equipment, and the space required in the plant facility to accommodate the equipment.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. | A method and apparatus for providing motor vehicle sub-assemblies with unrestricted model mix and quick changeover between models. The apparatus includes a track; a carriage mounted for longitudinal movement along the track between first and second positions; and first and second turrets rotatably mounted on the carriage at longitudinally spaced locations and each including a plurality of circumferentially spaced individual faces and unique tooling fixtures on the respective faces for receiving unique work piece components corresponding to a plurality of motor vehicle body styles. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a method for the separation of coal from ROM coal. More particularly, it relates to a method for separating coal from slate, shale, limestone, fireclay, and boney coal present in ROM coal.
As presently mined, ROM coal contains many impurities such as slate, shale, limestone, fireclay, and boney coal in varying concentrations. These and various other impurities in the ROM coal are hereinafter referred to as refuse. Separation of the coal from the refuse is generally required for about 2/3 of all the bituminous coal mined in the United States before the coal can be economically used in an environmentally acceptable manner. Separation of coal from the refuse has been conducted through techniques such as jigging, heavy media separation, shaking tables, and hydrocyclones. These techniques are based upon differences between the specific gravities of coal and the refuse. All of these techniques require large volumes of water to achieve desired separation. Gravity separation techniques are limited where large amounts of water are not available. Efficiency of separation of these techniques decreases as the specific gravities of the coal and refuse approach each other. For example, it is difficult to separate good coal from boney coal, as there is only a small difference between their specific gravities.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a method for the separation of higher BTU coal from ROM coal containing particles of higher BTU coal, lower BTU coal and refuse, which comprises conditioning the ROM coal (or any lower grade coal) with a coupling agent capable of selectively coating the particulate coal to the substantial exclusion of coating refuse, which coupling agent is at least one alcohol containing from about 6 to 22 carbon atoms. Also added, preferably combined with said coupling agent, is a fluorescent dye in a quantity to make the coated particles of coal fluoresce upon excitation to a degree sufficient to distinguish the higher grade coated coal particles from the lesser coated, lower grade coal particles and the substantially non-coated refuse. The fluorescent dye coupled to the coal particles is excited to induce fluorescence and the fluorescing, higher grade coated coal particles are separated from the substantially non-fluorescing, refuse particles and the lesser intensity fluorescing, lower grade coal particles.
As used herein, "higher grade" and "higher BTU" mean particles of economically significantly greater fuel value (or carbon, including hydrocarbon, content) as compared to "lower grade" or "lower BTU" coal or "refuse" (which has substantially no economic value as a fuel. It is to be understood that the distinction between higher and lower grade or BTU is a matter of economic choice. Once the economic choice (e.g. of a minimum BTU particle) is made, the sorting apparatus can be set to separate particles which possess a higher or lower fluorescent intensity than that chosen as the "cut-off point" corresponding to the intensity of a particle of the desired minimum BTU.
It should also be understood that the intensity cut-off point can be chosen so as to substantially separate refuse of substantially no fuel value from very low grade coal; however, the economic choice will more frequently be to separate higher BTU from lower BTU particles. For convenience, hereinafter, the process will be described as separation of refuse from ROM coal, but is intended to also describe to one of skill in the art how to separate higher from lower grade coal.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, there is provided a method for the separation of refuse from ROM coal to recover coal therefrom. The practice of the method of this invention involves the separation of coal from the refuse present in the ROM coal. The ROM coal to be separated is conditioned with a coupling agent that will selectively coat the coal (or carbonaceous material) in a particle but will not coat the non-carbonaceous refuse. Combined with the coupling agent is a fluorescent dye that is capable of fluorescence when excited. The conditioned ROM coal is exposed to electromagnetic radiation to excite the fluorescent dye. The coated coal particles will fluoresce, whereupon they can be separated from the substantially non-coated, non-fluorescing refuse particles.
It should also be understood that a non-fluorescent dye or pigment which has a distinctive color in the visible range can be combined with the coupling agent, whereby the sorting can be done by eye or optical detection apparatus.
The method of the present invention is based upon the differences in surface chemical properties of the material present in ROM coal. Due to these differences, there can be utilized a coupling agent that will substantially, selectively coat only the carbonaceous coal present. By proper selection of coupling agent, the desirable coal in the ROM coal can be separated from the undesirable refuse. Surface chemical properties are relatively more consistent than other properties such as color, reflectance, or conductivity. These other properties tend to be similar for coal and refuse requiring a fine degree of resolution to distinguish between the coal and refuse. Such a degree of resolution is difficult to obtain and, therefore, the efficiency of separation based upon these properties suffers. Separation of material based upon the surface chemical properties is, therefore, more consistent than techniques based upon the above other properties.
To distinguish between the coupling agent coated coal and the non-coated material, there is incorporated with the coupling agent a tagging agent, such as a fluorescent dye. Following coating of the ROM coal with the coupling agent and dye, the ore can be radiated with electromagnetic radiation to cause the dye to fluoresce. The dye coupled with the coal by the coupling agent that is coating the coal will fluoresce to a substantial degree and the non-coated refuse material will essentially not fluoresce, thereby enabling the materials to be separated by differences in fluorescence.
Generally, fluorescence refers to the property of absorbing radiation at one particular wavelength and simultaneously re-emitting light of a different wavelength so long as the stimulus is active. It is intended in the present method to use the term fluorescence to indicate that property of absorbing radiation at one particular wavelength and re-emitting it at a different wavelength, whether or not visible, during exposure to an active stimulus or after exposure or during both these time periods. This, fluorescence is used generically herein to include fluorescence and phosphorescence, and envisions the emission of electromagnetic waves whether or not within the visible spectrum.
Electromagnetic radiation generally refers to the emission of energy waves of all the various wavelengths encompassed by the entire electromagnetic spectrum. It is intended in the present method to use the term electromagnetic radiation to indicate any and all stimuli that will excite and induce fluorescence of the fluorescent dye. Thus, electromagnetic radiation is used generically herein to include electromagnetic radiation and envisions other stimuli that will excite and induce fluorescence of the fluorescent dye.
The choice of a water-soluble or an oil-soluble dye is further described in Ser. No. 897,740 filed on the same day as the present application, of Brij M. Moudgil, titled "Separation of Limestone from Limestone Ore", (the entire disclosure of which is incorporated herein).
In general, if the coating on the coal (or carbonaceous material) is hydrophobic, an oil-soluble dye would be chosen to cause the coal to fluoresce; however, a water-soluble dye could be applied, which would preferentially coat the refuse in which case the higher grade coal would have a lower intensity and the refuse the higher fluorescence (or visible color). Similarly, if a coupling agent is used (e.g. a polyhydric alcohol) which produces a hydrophilic surface on the "carbon" of the coal, an oil-soluble dye (in an organic solvent) could be used to preferentially "color" the refuse or a water-soluble dye, in aqueous solution, could be used to preferentially color the carbonaceous material.
In practicing the present method in regard to ROM coal is, in general, first subjected to a crushing step. The ROM coal is crushed to physically separate the coal from the refuse present. Crushing increases the surface area of the particles and further provides a greater surface and reactive site for the coating of the particles by the coupling agent and fluorescent dye. In this crushing step, the ROM coal as mined is crushed to a particle size of from about 1/4 to about 8 inches. It is preferred to crush the ROM coal in particle sizes of from about 1/2 to 3 inches. Particles less than 1/4 inch and greater than 8 inches can be used in the practice of the method of this invention. However, the coating and separation of ore particles of less than 1/4 inch is less economically attractive and ore particles of greater than 8 inches entrain impurities so as to make the separation process less efficient. Following the crushing and sizing process, the ROM coal can be deslimed to remove soluble impurities and surface fines on the particles.
Following the crushing and desliming steps, the ROM coal is conditioned with a coupling agent selected from an alcohol or mixture of alcohols containing from about 6 to about 22 carbon atoms. Preferably, the alcohol is monohydric, to produce a hydrophobic surface on the carbonaceous material in the particles. It is preferred to select at least one alcohol containing from about 8 to about 14 carbon atoms. Alcohols of more than about 22 carbon atoms tend to be less selective in coating only the coal particles. Therefore, since alcohols of more than about 22 carbon atoms are not as selective in coating the particles in the ROM coal, the efficiency of the separation decreases. Alcohols of less than about 6 carbon atoms will not generally remain on the coal particles.
Suitable alcohols useful as coupling agents in the practice of the method of the present invention include, but are not limited to: 1-hexanol, 1-decanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-heneicosanol and 1-docosanol.
The coupling agent is combined with a marking agent, preferably a fluorescent dye, to distinguish coated particles from uncoated particles. Fluorescent dyes known to those skilled in the art and which are compatible with the coupling agents can be used in the practice of the method of this invention. Many such fluorescent dyes are commerically available, such as fluoranthene and fluorescent yellow G. (product of Morton Chemical, Chicago). It is preferred that the fluorescent dye be water-insoluble. Water-soluble fluorescent dyes can remain in the dispersant water used during the conditioning of the ore and can, therefore, be entrained in an aqueous surface coating on the refuse as well as combined with the coupling agent coating the coal. Thereby, the efficiency of distinguishing between the coal and refuse would be reduced. The preferred water-insoluble dyes remain combined with the coupling agent and are not attracted to the surface of the refuse particles.
The fluorescent dye can be combined with the coupling agent either before or after the ROM coal is conditioned with the coupling agent. The fluorescent dye can be used in any form, such as a solution, suspension, emulsion, dispersion or alone. The fluorescent dye can be combined with the coupling agent prior to conditioning the ROM coal by either mixing the fluorescent dye directly with the coupling agent or by mixing the fluorescent dye with a suitable diluent or solvent such as an oil, then mixing with the coupling agent. If the fluorescent dye is combined with the coupling agent following the alcohol-conditioning of the ROM coal, it can be applied directly to the conditioned ROM coal or it can be used in one of the above forms such as by mixing the dye with the diluent or solvent, then applying it to the conditioned ore. The fluorescent dye has an affinity toward the coupling agent coating and will, therefore, be attracted to and entrained substantially in only the coated coal particles. Any dye that adheres to the refuse particles, generally, is rinsed off through a wash of the ROM coal. It is preferred to combine the coupling agent and fluorescent dye prior to conditioning the ROM coal. Such prior treatment uses less flourescent dye, requires fewer steps and is generally more efficient both economically and in separation results.
To condition the ROM coal, the coupling agent is mixed with the sized ROM coal. The coupling agent can be dissolved in a suitable solvent, mixed with a dispersant such as water, or can be used alone. It is preferred to form a dispersion of the coupling agent in water. The aqueous dispersion is then contacted with the ROM coal. Many methods can be employed to contact the dispersion with the ROM coal. Such methods include, but are not limited to, spraying the dispersion onto the particles, passing the particles through a dispersion bath, and the like. It is preferred to spray the ROM coal particles with the dispersion of coupling agent in water. Such a spraying operation can consist of spraying the ROM coal particles as they pass on a belt or shaker bed. The ROM coal can also be passed through a ring sprayer or series of ring sprayers as in Ser. No. 897,946, filed concurrently herewith of Moudgil and Roeschlaub, titled "Method and Apparatus for Selective Wetting of Particles", the entire disclosure of which is hereby incorporated herein, to condition and coat the coal particles. The excess dispersion and that physically entrained in the particles can be washed from the ROM coal and used on a subsequent batch. Due to the surface chemical properties of the coal, the coupling agent selectively adheres to the coal and will coat the coal with a coating capable of fluorescence, which will allow the coal to be separated from the refuse present in the ROM coal.
Following the conditioning of the ROM coal, the ROM coal is exposed to electromagnetic radiation to cause the coating on the coal particles to fluoresce. The coated fluorescing particles can be separated from the substantially non-fluorescing particles by many different means, such as by hand or by an optical sorting device such as the Matthews' apparatus taught by Matthews' U.S. Pat. No. 3,472,375, incorporated herein by reference. In the Matthews' apparatus, a free-falling mixture of ore passes in front of a row of detectors. Each detector by proper attenuation is capable of distinguishing between non-fluorescence and fluorescence or in degree of fluorescence. Each detector in turn controls one flowing fluid stream selectively directed transverse to the path of the falling particle, the fluid stream being permitted to impinge only on the properly emitting ore particles. The directed fluid stream deflects the ore particles into a divergent path by which they are separated from the undesired ore particles. Such an apparatus is capable of detecting and separating the coupling agent and dye-coated particles from the non-coated particles.
The invention is further illustrated by the following examples, which are not intended to be limiting.
EXAMPLE 1
A quantity of crushed coal consisting of 83% by weight coal with an average particle size of from 1.5 to 2 inches was conditioned with a coupling agent of decyl alcohol coupled with fluoranthene. Fluoranthene fluorescent dye was dissolved in decyl alcohol. An aqueous dispersion of decyl alcohol, and fluoranthene dye, in water was made. The aqueous dispersion was sprayed onto the crushed and sized coal and refuse particles. The decyl alcohol coupling agent combined with fluoranthene selectively coated the carbonaceous matter or "coal" particles and was rejected by the non-carbonaceous matter or refuse particles. The excess aqueous dispersion was washed from the coal with a water wash.
The coated coal particles were separated from the non-coated refuse particles through the use of a Matthews' separator apparatus as shown in U.S. Pat. No. 3,472,375 by passing free-falling particles of the ore in front of a radiating source and subsequently fluorescence detectors. The coated coal particles fluoresced substantially to a greater degree than the refuse when radiated. Each detector had been attenuated to detect the degree of fluorescence of the coal particles and each controlled one flowing fluid steam selectively directed transverse to the path of the falling particles. The fluid streams impinged only on the fluorescing coal particles. The directed fluid stream deflected the fluorescing coal particles on a divergent path from the free-falling, substantially non-fluorescing refuse particles.
The fluorescing coal particles recovered consisted of 99% coal and accounted for 98% of the coal present in the initial feed material.
The initial feed material had an ash content of 17.3%, a total sulfur content of 0.52%, a pyritic sulfur content of 0.2%, and a BTU/lb rating of 11,339. The fluorescing coal particles separated by the method of this invention had an ash content of 5%, sulfur content of 0.47%, pyritic sulfur content of 0.1%, and a BTU/lb rating of 13,384.
There was a total BTU recovery from the upgraded coal of 96%. The rejected substantially non-fluorescing particles had an ash content of 71.1%, a sulfur content of 0.72%, a pyritic sulfur content of 0.6%, and a BTU/lb rating of 2,377.
EXAMPLE 2
The procedure of Example 1 was repeated in all essential details except the coupling agent used was decyl alcohol combined with the fluoranthene and fluorescent yellow G. The initial coal ore consisted of 88% by weight coal. The fluorescing coal particles recovered consisted of 99.5% coal and accounted for 92% of the coal present in the initial feed material.
The initial feed had an ash content of 19.4%, a sulfur content of 0.12%, a pyritic sulfur content of 0.45%, and a BTU/lb rating of 13,445. The fluorescing coal particles separated by the method of this invention had an ash content of 9.93%, a sulfur content of 0.07%, a pyritic sulfur content of 0.44%, and a BTU/lb rating of 15,138 for a BTU recovery of 91%. The substantially non-fluorescing refuse particles contained 59.64% ash, 0.27% sulfur, 0.50% pyritic sulfur, and had a BTU/lb rating of 6,155.
EXAMPLE 3
The procedure of Example 2 was repeated in all essential details except the initial feed material coal was of a particle size of from 1.5 to 2.5 inches and contained 75% by weight coal.
The fluorescing coal particles recovered consisted of 99% coal and accounted for 94% of the coal present in the initial ore.
The initial feed material consisted of 26.5% ash, 0.45% sulfur, 0.08% pyritic sulfur, and had a BTU/lb rating of 9,729. The fluorescing coal particles separated by the method of this invention consisted of 7.36% ash, 0.52% sulfur, 0.14% pyritic sulfur, and had a BTU/lb rating of 12,563 for a BTU recovery of 91%. The substantially non-fluorescing refuse particles contained 72.53% ash, 0.28% sulfur, 0.14% pyritic sulfur, and had a BTU/lb rating of 2,900.
EXAMPLE 4
The procedure of Example 2 was repeated in all essential details except the initial feed material was of a particle size of from 1.5 to 2.5 inches and contained 55% by weight coal.
The fluorescing coal particles recovered consisted of 91% coal and accounted for 98% of the coal present in the initial feed material.
The initial feed material consisted of 46.19% ash, 0.42% sulfur, 0.14% pyritic sulfur, and had a BTU/lb rating of 7,058. The fluorescing coal particles separated by the method of this invention consisted of 15.54% ash, 0.49% sulfur, 0.13% pyritic sulfur, and had a BTU/lb rating of 11,637 for a BTU recovery of 96%. The substantially non-fluorescing refuse particles contained 80.64% ash, 0.22% sulfur, 0.16% pyritic sulfur, and had a BTU/lb rating of 728.
EXAMPLE 5
The procedure of Example 1 is repeated in all essential details except the coupling agent is octanyl alcohol. The octanyl alcohol selectively coats the coal particles, but does not coat the refuse present in the coal ore.
The coated coal particles fluoresce when radiated with electromagnetic radiation. The fluorescing, coated coal particles are separated from the substantially non-fluorescing refuse particles.
EXAMPLE 6
The procedure of Example 1 is repeated in all essential details except the coupling agent is n-tetradecanol. The tetradecanol selectively coats the coal particles, but does not coat the refuse present in the coal ore.
The coated coal particles fluoresce when radiated with electromagnetic radiation. The fluorescing, coated coal particles are separated from the substantially non-fluorescing refuse particles.
EXAMPLE 7
The procedure of Example 1 is repeated in all essential details except eicosanyl alcohol is used as the coupling agent. The eicosanyl alcohol selectively coats the coal particles, but does not coat the refuse present in the coal ore.
The coated coal particles fluoresce when radiated with electromagnetic radiation. The fluorescing, coated coal particles are separated from the non-fluorescing refuse particles. | A method is disclosed for the separation of coal from run of mine (ROM) coal containing particles of coal and refuse, which comprises conditioning the ROM coal with a coupling agent capable of selectively coating the particulate coal to the substantial exclusion of coating the refuse, which coupling agent is at least one alcohol containing from about 6 to about 22 carbon atoms. Combined with said coupling agent is a fluorescent dye in a quantity to make the coated particles of coal fluoresce upon excitation to a degree sufficient to distinguish the coated coal particles from the substantially non-coated refuse. Exciting (e.g. as with ultraviolet light) the fluorescent dye coupled to the coal particles induces fluorescence and enables separating the fluorescing, coated coal particles from substantially non-fluorescing, non-coated refuse particles. | 1 |
TECHNICAL FIELD
The present technology is directed generally to vibration meters, and associated systems and methods.
BACKGROUND
Vibration can be an important consideration when designing, testing, and maintaining machinery. For example, significant levels of vibration can indicate poor design or an impeding failure of the machinery. The presence of unexpected frequency peaks in a vibrating structure may indicate nonlinear interactions among the natural frequencies of the subassemblies, which can cause premature failure of the machinery. In some applications, detecting an increase in vibration amplitude is a trigger for initiating equipment maintenance and/or service.
Vibration detection is often performed in the field by attaching one or more accelerometers or other vibration sensors to the rotating machinery or other vibrating structure. Vibration sensors produce output signals that can be used to determine the amplitude and frequency of vibration. It is known that contact between the vibration sensor and the vibrating structure can be improved by rigidly attaching vibration sensors (i.e., accelerometers) to the rotating machinery. In general, rigidly attaching the vibration sensor improves the transmission of vibrations from the vibrating structure to the sensor. However, such rigid attachment may not be possible or at least not practical with hand held vibration meters, which are preferred for the field use. Instead, a hand held vibration detector is typically kept by hand in contact with rotating machinery in the field to measure the vibrations.
FIG. 1 is a plan view of a conventional vibration meter 100 . In operation, a wand 3 of the vibration meter 100 contacts a vibrating structure 5 . The vibrations are transmitted through the wand 3 to an accelerometer 2 inside a housing 4 . When subjected to vibrations, the accelerometer 2 produces an output signal to be routed to electronics within the unit 100 via wires 6 . The unit 100 then determines vibration amplitude/frequency based on the signal coming from the accelerometer. The output (i.e., the amplitude and frequency of the vibration) can be displayed using display 7 . However, such a conventional device is sensitive to the quality of contact between the device and the vibrating structure. Therefore, the accuracy of reading for the vibration sensor in a hand-held device remains a problem.
BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on clearly illustrating the principles of the present disclosure. Furthermore, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is a plan view of a hand held vibration meter in accordance with the prior art.
FIG. 2 is a plan view of a hand held vibration meter in accordance with an embodiment of the presently disclosed technology.
FIG. 3A is an exploded view of a hand held vibration meter in accordance with an embodiment of the presently disclosed technology.
FIG. 3B is an isometric view of a force sensor assembly in accordance with an embodiment of the presently disclosed technology.
FIG. 4 is a graph of a sensitivity of the vibration sensor as a function of frequency.
FIG. 5 is a schematic diagram of the vibration sensor output linearization in accordance with an embodiment of the presently disclosed technology.
DETAILED DESCRIPTION
Specific details of several embodiments of representative vibration meters and associated methods for vibration measurements are described below. In some embodiments of the present technology, the vibration meter is a hand held device that contacts a vibrating structure (e.g., rotating machinery) and measures vibrations of the vibrating structure. The vibration meter can also include a force sensor to measure force between the vibration sensor and the vibrating equipment. The measurement of force can be used to improve accuracy of the vibration reading (e.g., amplitude and frequency) because the output of the vibration sensor generally changes with the intensity of the contact force between the vibration meter and the vibrating structure. Therefore, in some embodiments, the output of the vibration sensor can be combined with the force reading to produce an adjusted output that automatically takes into account the contact force without further input from the user. Furthermore, one or more vibration isolators can contact the vibration sensor to filter the noise created by the unsteadiness or shaking of the hand of the operator, which, if unfiltered, would appear as low frequency vibrations at the output of the vibration sensor. A person skilled in the relevant art will also understand that the technology may have additional embodiments, and that the technology may be practiced without several of the details of the embodiments described below with reference to FIGS. 2-5 .
FIG. 2 illustrates a vibration meter 200 in accordance with embodiments of the presently disclosed technology. The vibration meter 200 has a housing 70 that can be made from molded plastic or other suitable materials. In operation, the vibration meter 200 can be hand held against a vibrating structure 5 such that a vibrating sensor 10 contacts the vibrating structure. In other embodiments of the technology, the vibrating sensor may contact the vibrating structure 5 through an intermediary element (not shown) that transfers the vibrations from the vibrating structure to the vibrating sensor. The vibrating sensor 10 can be protected from mechanical or environmental damage by a jacket 25 , which can be made of rubberized molded plastic, metal, textile, or other suitable materials. In some embodiments, the vibrating sensor 10 can have a tip 11 that is harder than the rest of the vibrating sensor 10 to improve the contact between the vibrating sensor 10 and the vibrating structure 5 . A person skilled in the art would know of many examples of vibrating sensors including, for example, accelerometers. The vibrating sensor 10 is connected to signal processing electronics (not shown in FIG. 2 ) inside the housing 70 . The signal processing electronics can determine the amplitudes and frequencies of the vibration based on the output from the vibration sensor 10 . For example, the amplitude of vibration can be determined by twice integrating the signal from the vibration sensor 10 (e.g., an accelerometer). A person skilled in the art would know of many methods for numerically or electronically integrating a vibrating sensor signal to determine the corresponding displacement of the vibrating structure under the measurement. Command buttons 80 and a display 90 can be used to select and display the frequencies and amplitudes of vibrations corresponding to the vibrating structure 5 . As discussed in detail with reference to FIGS. 3A-5 below, the low frequency noise can be filtered from the vibration sensor 10 . Furthermore, the signal from the low frequency noise can be processed in conjunction with the signal from the force sensor to yield a more accurate vibration reading.
FIG. 3A shows an exploded view of the vibration meter 200 configured in accordance with embodiments of the presently disclosed technology. Starting from the upper right corner of the figure, the vibration sensor jacket 25 can at least partially house the vibration sensor 10 for protection from environmental or mechanical damage. Additionally, in at least some embodiments, the vibration sensor 10 can be at least partially contacted by vibration isolators 16 , 20 . With conventional hand held vibration meters, the vibration of the operator's hand can be transferred to the vibration sensor 10 and may be erroneously interpreted as being generated by the vibrating structure itself. The vibration of the operator's hand is typically in the low frequency range (e.g., less than about 50 Hz). In at least some embodiments of the inventive technology, the vibration isolators 16 , 20 can filter out these low frequencies before they reach the vibration sensor 10 . The vibration isolators 16 , 20 can be made of rubber-like material or other material that attenuates vibrations of the vibration sensor 10 for the frequencies of interest. For example, the rubber-like material can be selected based on its known frequency attenuating properties. The vibration isolators 16 , 20 can have lips 17 , 21 , respectively, for a more secure engagement with the vibration sensor 10 . An output signal from the vibration sensor can be transferred through a cable 11 to an interface board 61 and further to signal processing electronics (not shown).
The vibration meter 200 also can include a force sensor 30 . When the vibration meter 200 presses against the vibrating structure (not shown), the contact force is transferred from the vibration sensor 10 to the force sensor 30 , as explained in more detail with reference to FIG. 3B below. The force sensor can be supported by a structure, for example, a combination of load boss 65 , a load beam 55 and a load beam brace 50 , to keep the force sensor in place. Screws 70 can engage with receiving threaded holes 26 to hold the parts of the vibration meter 200 in contact.
FIG. 3B shows an isometric view of the force sensor 30 positioned between a pad 45 and a plunger 40 . A person skilled in the art would know of many force sensors available on the market including, for example, load cells and film resistor force sensors. A plunger 40 having a generally flat first surface 41 can transfer contact force from the vibration sensor to the force sensor 30 , which can be sandwiched between the plunger 40 and the pad 45 . In some embodiments, the force sensor 30 can be preloaded to precondition its output within the range of sensitivity. The preloading can be achieved by, for example, pressing the plunger 40 against the force sensor 30 that is supported by the elastic pad 45 on the opposite side. When loaded, the force sensor 30 changes its electrical resistance. This change in the resistance, corresponding to the change in force, can be measured through a connector 35 . As explained below with reference to FIG. 4 , the measurements of vibration amplitude can be improved based on the value of contact force between the vibrating structure and the vibrating sensor.
FIG. 4 is a graph of frequency response of the vibration sensor 10 . The horizontal axis of the graph shows a range of frequencies on a logarithmic scale. The vertical axis on the left shows a sensitivity of the vibration sensor in dB. The sensitivity of a vibration sensor can be interpreted as, for example, a ratio of the amplitude indicated at output of the vibration sensor 10 and the vibration amplitude of the vibrating structure itself. The sensitivity that is close to zero on the logarithmic scale of graph 300 corresponds to a sensitivity value of about one on the linear scale. Conversely, a positive value on the vertical axis indicates a higher sensitivity and a negative value on the vertical axis indicates a lower sensitivity. In general, the sensitivity of a vibration sensor is a function of the vibration frequency. Furthermore, if the sensitivity of vibration sensor is known, an appropriate coefficient or other adjustment can be used to determine the relevant vibration amplitude of the vibration structure at particular frequency of vibration.
The vertical axis on the right shows the vibration amplitude. Normally, the sensitivity of the vibration sensor as a function of frequency can be obtained from the vibration sensor manufacturer or it can be determined experimentally. Therefore, the amplitude of vibration can be back-calculated for a particular frequency of vibration. However, if the sensitivity of the vibration sensor is also a function of the contact force between the sensor and the vibrating structure, a measurement of the vibration amplitude that does not take the contact force into account may reduce the accuracy of the measurement. For example, curves F 1 , F 2 , F 3 in FIG. 4 may correspond to the vibration amplitude measurements over a range of frequencies, but using different contact force. A person having ordinary skill in the art would know that for a given frequency of vibration an amplitude of vibration can be calculated by integrating the acceleration signal twice and by adjusting the result based on the known sensitivity of the vibration sensor.
In the illustrated example, for the frequency of vibration of about 1.4 kHz, the vibration sensor would indicate vibration amplitudes A 1 , A 2 , or A 3 for the respective sensitivity curves F 1 , F 2 , F 3 , depending on the magnitude of the contact force between the vibration sensor and the vibrating structure. To obtain more precise vibration amplitude measurements the contact force can be measured and used to select appropriate sensitivity curve, e.g., F 1 , F 2 or F 3 . The amplitude of the vibrating structure can then be determined from the appropriate sensitivity curve. For example, the force sensor 30 (described with reference to FIGS. 3A-3B ) can measure contact force, which is in turn used to select the correct vibration sensitivity curve among the sensitivity curves F 1 , F 2 and F 3 . In at least some embodiments, the sensitivity curves can be available in a tabulated form for easier calculations per relevant frequencies of vibration. The tabulated sensitivity curves can be accessed using suitable electronics based on the force sensor reading, and then further processed to calculate the vibration amplitude using, for example, signal integrating algorithms. In some embodiments, the sensitivity curves can be linearized using linearization circuits. For example, the sensitivity curves F 1 , F 2 , F 3 can be linearized to yield linearized sensitivity curves L 1 , L 2 , L 3 , respectively. In at least some embodiments, the linearized sensitivity curves make the vibration amplitude calculation easier and/or faster.
FIG. 5 is a schematic diagram of a linearization circuit 500 in accordance with embodiments of the presently disclosed technology. A non-linear input 110 (for example the sensitivity curves F 1 , F 2 , F 3 shown in FIG. 4 ) can be fed to a function generator 120 which outputs a function which can be attenuated by an attenuator 130 . Next, the non-linear input 110 and the output of the attenuator 130 can be summed up in a summing amplifier 140 to produce a linearized output 150 (for example the linearized sensitivity curves L 1 , L 2 , L 3 shown in FIG. 4 ). The linearized output 150 can be used for easier determination of the vibration amplitudes. Many function generators and linearization circuits are commercially available on the market, for example function generators AD640, AD639, AD538 and linearization circuits AD7569 by Analog Devices, Norwood, Mass.
From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the disclosure. For example, in some embodiments, a function analyzer can be used in conjunction with the disclosed technology to help in determining dominant frequencies. In other embodiments, the output of the vibration sensor can be acquired by an analog-to-digital conversion circuit for a subsequent data processing which may be done outside of the vibration detector. Furthermore, the vibration detector may include analog or digital frequency filters for eliminating the unwanted harmonics or subharmonics of the main frequencies of the vibration structure. Moreover, while various advantages and features associated with certain embodiments have been described above in the context of those embodiments, other embodiments may also exhibit such advantages and/or features, and not all embodiments need necessarily exhibit such advantages and/or features to fall within the scope of the technology. Accordingly, the disclosure can encompass other embodiments not expressly shown or described herein. The following examples provide further embodiments of the present technology. | A vibration detector suitable for field use and associated systems and methods are disclosed. A representative apparatus includes a vibration sensor in contact with the vibrating structure. The vibration sensor can be in contact with the vibration isolators to eliminate the frequencies of the operator's hand. In some embodiments, a contact force between the vibration sensor and the vibrating structure can be measured using, for example, contact resistors. Since the sensitivity of the vibration sensor can be a function of the contact force, the vibration amplitude measurements can be adjusted for a known contact force to improve the precision of the vibration amplitude measurement. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of and priority to U.S. Provisional Patent Application No. 60/987,444, filed Nov. 13, 2007, the entire disclosure of which is incorporated by reference herein.
BACKGROUND
1. Technical Field
The present disclosure relates to a dual lumen catheter having an operative passageway for use in minimally invasive endoluminal surgery. More particularly, the present disclosure relates to a duel lumen catheter and method of performing minimally invasive endoluminal surgery through the stomach of a patient.
2. Background of Related Art
Surgeons are constantly searching for ways of performing surgical procedures within the body of a patient in a minimally invasive manner. This is desirable in order to reduce scarring, as well as, to shorten the healing or recuperation time of a patient from the surgery. As an example, one way to accomplish this is through the use of trans-luminal or trans-gastric surgery. In these methods, the surgeon inserts various instruments through the esophagus of the patient to gain access to the stomach. Once the stomach has been reached, and opening in the gastric wall is accomplished to gain access to the peritoneal cavity and perform various surgeries, such as, for example, hernia repair, etc.
In these surgical procedures the peritoneal cavity is typically insufflated to provide a visualization area and\or working room for the surgical instruments. However, a potential problem exists when the peritoneal cavity is pressurized in that the pressure created within the peritoneal cavity pushes down on the stomach thereby flattening the stomach and making it difficult to manipulate surgical and/or visualization instruments through the interior of the stomach.
Thus, it would be desirable to provide a catheter and method of performing a trans-gastric surgery without the attendant problem of stomach collapse due to pressurization of the adjacent peritoneal cavity.
SUMMARY
There is disclosed a dual lumen catheter for use in minimally invasive surgery. The catheter generally includes a hub, a first tube extending through the hub and defining an operative lumen from the hub to a distal end of the first tube. A second tube extends parallel to the first tube and sealed at its distal end. The distal end of the second tube is positioned proximally of the distal end of the first tube, wherein the second tube defines an inflation lumen.
In one embodiment the second tube is positioned concentrically about the first tube. The second tube includes inflation ports positioned adjacent the distal end of the second tube. A seal is positioned between the first and second tubes to seal the distal end of the second tube. A valve system is in fluid communication with the inflation lumen such that the valve system applies a source of fluid through the inflation lumen.
The first tube includes ports positioned adjacent the distal end of the first tube and includes a cutting edge at the distal end thereof.
In an alternative embodiment, the first and second tubes extend through and distally of a support tube associated with the hub. A seal is positioned within the support tube and about the first and second tubes to seal interior of the support tube. The second tube includes inflation ports positioned adjacent the distal end of the second tube.
There is also disclosed a method of performing a minimally invasive procedure utilizing a dual lumen catheter. A catheter is provided having a first tube defining an operative lumen and a second tube, parallel to the first tube, defining an inflation lumen and terminating proximally of the distal end of the first tube. The catheter is inserted through the esophagus of a patient so as to position a distal end of the second tube within the stomach of a patient. The catheter is further advanced through the esophagus of a patient so as to position the distal end of the first tube outside of the stomach of the patient and a surgical operation is performed through the first tube and outside the stomach of the patient. The method further includes pressurizing the interior of the stomach by forcing a fluid through the inflation lumen and pressurizing an area outside of the stomach by forcing a fluid through the operative lumen.
In one use of the disclosed method the wall of the stomach is punctured with the distal end of the first tube.
DESCRIPTION OF THE DRAWINGS
Various embodiments of the presently disclosed dual lumen surgical catheter are disclosed herein with reference to the drawings, wherein:
FIG. 1 is a perspective view of one embodiment of a duel lumen catheter for use in minimally invasive endoluminal surgery;
FIG. 2 is a cross-sectional view taken along the line 2 - 2 of FIG. 1 ;
FIG. 3 is a cross-sectional view taken at the junction of the outer tubular member and the inner tubular member;
FIG. 4 is a perspective view, partially shown in section, illustrating the embodiment of FIG. 1 initially inserted into a patient;
FIG. 5 is a perspective view, similar to FIG. 4 , illustrating the operating end of the catheter positioned within the peritoneal cavity of the patient;
FIG. 6 is a perspective view of an alternative embodiment of a duel lumen catheter for use in minimally invasive endoluminal surgery;
FIG. 7 is a cross-sectional view taken along lines 7 - 7 of FIG. 6 ;
FIG. 8 is a cross-sectional view taken at the junction of an outer sheath with the inner lumens;
FIG. 9 is a perspective view, partially shown in section, illustrating the embodiment of FIG. 6 initially inserted into a patient; and
FIG. 10 is a perspective view, similar to FIG. 9 , illustrating the operating end of the catheter positioned within the peritoneal cavity of a patient.
DETAILED DESCRIPTION OF EMBODIMENTS
Embodiments of the presently disclosed dual lumen catheter and methods of endoluminal surgery will now be described in detail with reference to the drawings wherein like numerals designate identical or corresponding elements in each of the several views. As is common in the art, the term ‘proximal” refers to that part or component closer to the user or operator, i.e. surgeon or physician, while the term “distal” refers to that part or component further away from the user.
Referring to FIG. 1 , there is disclosed a dual lumen catheter 10 particularly suitable for use in endoluminal surgery to support the stomach against collapse during surgical procedures. Catheter 10 generally includes a hub 12 having an outer sheath 14 extending distally from hub 12 . An operative or inner tube 16 extends through hub 12 and sheath 14 and defines an operative lumen 18 extending from a proximal end 20 of inner tube 16 to a distal end 22 of inner tube 16 . Operative lumen 18 in inner tube 16 provides an access passageway for surgical instruments as well as a fluid flow path for insufflation fluids to insufflate the peritoneal cavity. A plurality of insufflation ports 24 are provided adjacent distal end 22 of inner tube 16 . Insufflations ports 24 are provided in case the instruments inserted through inner tube 16 block or seal the distal end of operative lumen 18 and thus prevent the flow of insufflation fluid out of the open end of operative lumen 18 . Distal end 22 of inner tube 16 may additionally be provided with a cutting edge 26 to facilitate advancement of distal end 22 through a stomach wall and a peritoneal lining. In order to steer or direct catheter 10 through the body of a patient, hub 12 may be provided with a pair of wings 28 . It should be noted that, however, other methods of steering catheter 10 to the body of a patient are contemplated here in such as, for example, various steerable guide wires etc. Additionally, other means or instruments known in the art may be provided to penetrate the stomach wall and peritoneal lining to provide access to the peritoneal cavity.
Catheter 10 is additionally provided with an outer tube 30 which extends partially over inner tube 16 to define a common longitudinal axis A-A. Outer tube 30 is sealed at a distal end 32 to inner tube 16 . A plurality of inflation ports 34 are provided adjacent distal end 32 of outer tube 30 and are spaced proximally from insufflation ports 24 at a distal end 22 of inner tube 16 . A T-collar 36 surrounds sheath 14 and is in fluid communication with inflation ports 34 at distal end 32 of outer tube 30 . A valve system 38 is in fluid communication with T-collar 36 through a fluid tube 40 . The inner tube 16 extends to a position 50 distal from the distal end 32 of the outer or insufflation tube 30 to define the common longitudinal axis A-A, the common longitudinal axis A-A extending at least to the position 50 . The distal end 22 of the inner tube 16 defines a portion 16 ′ of the inner tube 16 that extends at least from the position 50 to define an offset axis B-B with respect to the common longitudinal axis A-A. The offset axis B-B defines an offset angle θ with respect to the common longitudinal axis A-A of the inner tube 16 . Consequently, the radially oriented insufflation ports 24 in proximity to the distal end 22 of the operative or inner tube 16 are positioned at a position that is offset from the radially oriented insufflation ports 34 at the distal end 32 of the outer or insufflation tube 30 .
Referring for the moment to FIG. 2 , an inflation lumen 42 is defined between outer tube 30 and inner tube 16 . As shown, inner tube 16 and outer tube 30 , and thus operative lumen 18 and inflation lumen 42 , are concentric. Inflation lumen 42 carries inflation fluid from valve system 38 to inflation ports 34 at a distal end of outer tube 30 .
Referring to FIG. 3 , and as noted hereinabove, distal end 32 of outer tube 30 terminates proximally of distal end 22 of inner tube 16 and is sealed to inner tube 16 . Specifically, distal end 32 of outer tubes 30 is sealed to inner tube 16 by a circumferential seal 44 . Seal 44 may be formed by gluing distal end 32 to inner tube 16 or may be provided as a separate member which is glued, welded, or otherwise affixed to distal end 32 and inner tube 16 . Thus, fluid flowing from valve system 38 through inflation lumen 42 can only exit inflation ports 34 formed in distal end 32 of outer tube 30 .
Referring to FIGS. 4 and 5 , and initially with regard to FIG. 4 , the use of catheter 10 in endoluminal surgery to access the peritoneal cavity through the stomach will now be described. Initially, catheter 10 is inserted through the mouth M of a patient P and advanced through the esophagus E so as to position distal end 22 of inner tube 16 , as well as distal end 32 of outer tube 30 , within the stomach S of the patient. Once catheter 10 has been so positioned, a first source of insufflation fluid (not shown) may be attached to a valve system 38 and actuated to force a first inflation fluid F 1 through inflation lumen 42 and out inflation ports 34 in outer tube 30 in order to insufflate stomach S. The first source of inflation fluid may provide various auxiliary functions such as, for example, providing for pressure measurement so as to maintain constant pressure within the stomach, etc. While the present procedure is being described as insufflating stomach S prior to penetration of the stomach and the peritoneal cavity and insufflation of the peritoneal cavity, insufflation of stomach S may be delayed until after one or more of these steps have been accomplished.
With continued reference to FIG. 4 , catheter 10 is then further advanced through the esophagus E to cause cutting edge 26 at distal end 22 of inner tube 16 to engage and puncture stomach S.
Referring now to FIG. 5 , continued advancement of catheter 10 through esophagus E causes cutting edge 26 to form a hole 46 through stomach S and a hole 48 in peritoneal cavity PC to position distal end 22 of inner tube 16 within peritoneal cavity PC. Thereafter, a second source of inflation fluid (not shown) is connected to hub 12 and actuated to force a second inflation fluid F 2 through operative lumen 18 so as to insufflate peritoneal cavity PC. Once peritoneal cavity PC has been insufflated, operative lumen 18 is used as the access passageway for the insertion of instruments into peritoneal cavity PC to perform any of various surgical procedures. It should be noted that, during the performance of the surgical procedures, the fluid pressure within stomach S due to inflation fluid F 1 prevents the flattening or collapse of stomach S due to the inflation pressure in the peritoneal cavity PC and the activities of the surgical procedures being conducted therein. As with the first source of inflation fluid described hereinabove, the second source of inflation fluid might also be provided with auxiliary functions such as, for example, pressure measurement, pressure monitors and control devices, etc. in order to manage and adjust any losses in inflation pressure within peritoneal cavity PC during the surgical procedure.
It should be further noted that the disclosed catheter 10 and disclosed surgical method allows the surgeon to precisely control the pressures within peritoneal cavity PC and stomach S concurrently.
While not specifically shown, it is also contemplated that catheter 10 may be provided with the various anchoring and or sealing structures, such as, for example anchoring or sealing balloons adjacent distal ends 22 and 32 of inner tube 16 and outer tubes 30 , respectively. This will assist in preventing movement of catheter 10 during the surgical procedures as well as preventing leakage and/or transfer of inflation fluids between stomach S and peritoneal cavity PC.
Referring now to FIG. 6 , there is disclosed in alternative embodiment of a dual lumen catheter 50 . In contrast to dual lumen catheter 10 described hereinabove, the operative and inflation lumens of catheter 50 are parallel but not concentric as was the case with dual lumen catheter 10 . Catheter 50 generally includes a hub 52 having an outer sheath 54 extending distally therefrom. A support tube 56 extends through hub 52 and outer sheath 54 and encases the operative and inflation lumens of catheter 50 as described in more detail hereinbelow. Hub 52 is provided with a pair of wings 58 to facilitate manipulation of catheter 50 through the body of a patient.
A distal tube 60 extends through hub 52 , outer sheath 54 and support tube 56 to define a longitudinal axis N-A′. A proximal end 62 of distal tube 60 is positioned adjacent hub 52 while a distal end 64 of distal tube 60 is provided with a plurality of ports 66 . A cutting edge 68 may be provided on distal end 64 to facilitate puncturing of the stomach and the peritoneal cavity.
A proximal tube 70 extends partially through sheath 54 and through support tube 56 . Proximal tube 70 has a sealed distal end 72 and a plurality of ports 74 adjacent sealed distal end 72 . A T-collar 76 surrounds sheath 54 and is in fluid communication with ports 74 in proximal tube 70 . A valve system 78 is provided to receive of source of fluid and is connected to T-collar 76 by a fluid tube 80 .
Distal tube 60 defines an operative lumen 82 extending from proximal end 62 to distal end 64 . As best shown in FIG. 7 , inner tube 70 defines an inflation lumen 84 . Distal tube 60 and proximal tube 70 , and thus operative lumen 82 and inflation lumen 84 , extend through support tube 56 in parallel, but not concentric, fashion. The distal tube 60 extends at least to a position 92 that is distal from the sealed end 72 of the proximal tube 70 to define the longitudinal axis A′-A′. The distal end 64 of the distal tube 60 defines a portion 60 ′ of the distal tube 60 that extends at least from position 92 to define an offset axis B′-B′ with respect to the longitudinal axis A′-A′. Additionally, the sealed distal end 72 of proximal tube 70 extends through hub 52 , outer sheath 54 and support tube 56 to define a longitudinal axis A″-A″ along the proximal tube 70 . Since the distal tube 60 and proximal tube 70 , and thus operative lumen 82 and inflation lumen 84 , extend through support tube 56 in parallel fashion, the longitudinal axes A′-A′ and A″-A″ are also parallel to each other.
The offset axis B′-B′ of the portion 60 ′ of the distal tube 60 defines an offset angle θ 1 with respect to the longitudinal axis A′-A′ of the distal tube 60 . The offset axis B′-B′ also defines an offset angle θ 2 with respect to the longitudinal axis A″-A″ of the proximal tube 70 . When the two longitudinal axes A′-A′ and A″-A″ are precisely parallel, the offset angles θ 1 and θ 2 are equal. Consequently, the radially oriented insufflation ports 66 in proximity to the distal end 64 of the distal tube 60 are positioned at a position that is offset from the radially oriented insufflation ports 74 at the sealed distal end 72 of the proximal tube 70 .
Referring for the moment to FIG. 8 , both distal tube 60 and proximal tube 70 extend beyond support tube 56 . A seal 86 is provided within support tube 56 and about distal tube 60 and proximal tube 70 to prevent the influx of any fluids or other matter within support tube 56 during a surgical procedure.
Referring to FIGS. 9 and 10 , and initially with regard to FIG. 9 , the use of catheter 50 in endoluminal surgery to access the peritoneal cavity through the stomach will now be described. The following procedure is substantially identical to that described hereinabove with respect to catheter 10 . Initially, catheter 50 is inserted through the mouth M of a patient P and advanced through the esophagus E so as to position in distal end 64 of distal tube 60 as well as distal end 72 of proximal tube 70 within stomach S of the patient. Once catheter 50 has been so positioned, a first source of insufflation fluid (not shown) may be attached to a valve system 78 and actuated to force a first inflation fluid F 1 through inflation lumen 84 and out inflation ports 74 in proximal tube 70 in order to insufflated stomach S. As above, the first source of inflation fluid may provide various auxiliary functions such as, for example, providing for pressure measurement so as to maintain constant pressure within the stomach, etc. While the present procedure is being described as insufflated stomach S prior to penetration of the stomach and the peritoneal cavity and insufflation of the peritoneal cavity, insufflation of stomach S may be delayed until after one or more of these steps have been accomplished.
With continued reference to FIG. 9 , catheter 50 is then further advanced through the esophagus E to cause cutting edge 68 at distal end 64 of distal tube 60 to engage and puncture stomach S.
Referring now to FIG. 10 , continued advancement of catheter 50 through esophagus E causes cutting edge 68 to form a hole 88 through stomach S and a hole 90 in peritoneal cavity PC to position distal end 64 of distal tube 60 within peritoneal cavity PC. Thereafter, a second source of inflation fluid (not shown) may be connected to hub 12 and actuated to force a second inflation fluid F 2 through operative lumen 82 so as to insufflate peritoneal cavity PC. Once peritoneal cavity PC has been insufflated, operative lumen 82 is used as the access passageway for the insertion of instruments into peritoneal cavity PC to perform any of various surgical procedures. As noted hereinabove, the fluid pressure within stomach S due to inflation fluid F 1 prevents the flattening or collapse of stomach S due to the inflation the peritoneal cavity PC and the activities of the surgical procedures being conducted therein. As with the first source of inflation fluid described hereinabove the second source of inflation fluid might also be provided with auxiliary functions such as, for example, pressure measurement, pressure monitors and control devices, etc. in order to manage and adjust any losses in inflation pressure within peritoneal cavity PC during the surgical procedure.
It should be further noted that the disclosed catheter 50 and the disclosed surgical method allow the surgeon to precisely control the pressures within peritoneal cavity PC and stomach S concurrently.
While not specifically shown, it is also contemplated that catheter 50 , similar to catheter 10 described hereinabove, may be provided with the various anchoring and or ceiling structures, such as, for example anchoring or sealing balloons adjacent distal ends 64 and 72 of distal tube 60 and proximal tube 70 , respectively. This will assist in preventing movement of catheter 50 during the surgical procedures as well as preventing leakage and/or transfer of inflation fluids between stomach S and peritoneal cavity PC.
It will be understood that various modifications may be made to the embodiments disclosed herein. For example, additional lumens may be provided through the disclosed catheters to provide for auxiliary instruments such as, for example, endoscopes, etc. Further, as noted hereinabove, various anchoring and/or sealing structures may be provided on the disclosed tubes to prevent leakage as well as movement of the catheter within the body of the patient. Additionally, various known types of fluid sources and auxiliary devices for maintaining and monitoring pressure through the various lumens and within the various cavities in the body of the patient may be provided. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. | A duel lumen catheter is provided for use in minimally invasive surgery. The catheter generally includes a first tube defining an operative lumen and a second tube terminating proximally of the first tube and defining an inflation lumen. In one embodiment, the first and second tubes are concentric. In an alternative embodiment, the first and second tubes are separate and extend parallel to each other. The first and second tubes are provided with inflation ports adjacent their respective distal ends. There is also provided a method for performing minimally invasive surgery by inserting the catheter through the esophagus of a patient, insufflating the stomach and performing a surgical operation through the catheter and external to the stomach. | 0 |
FIELD OF THE INVENTION
[0001] The invention relates to an oil separator for an internal combustion engine. More particularly, the invention relates to an oil separator for removing oil from PCV gases of an internal combustion engine.
DESCRIPTION OF THE RELATED ART
[0002] An internal combustion engine typically includes a combustion chamber, where a fuel air mixture is burned to cause movement of a set of reciprocating pistons, and a crankcase, which contains the crankshaft driven by the pistons. During operation, it is normal for the engine to experience “blowby,” wherein combustion gases leak past the pistons from the combustion chamber and into the crankshaft. These combustion or blowby gases contain moisture, acids and other undesired by-products of the combustion process.
[0003] An engine typically includes a Positive Crankcase Ventilation (PCV) system for removing harmful gases from the engine and prevents those gases from being expelled into the atmosphere. The PCV system does this by using manifold vacuum to draw vapors from the crankcase into the intake manifold. Vapor is then carried with the fuel/air mixture into an intake manifold of the combustion chambers where it is burned. Generally, the flow or circulation within the system is controlled by the PCV valve, which acts as both a crankcase ventilation system and as a pollution control device.
[0004] It is normal for blowby gases to also include a very fine oil mist. The oil mist is carried by the PCV system to the manifold. The oil mist is then burned in the combustion chamber along with the fuel/air mixture. This results in an increase in oil consumption. A known method of removing oil from the blowby gases is to use a labyrinth or cyclone-type separator design. A path is provided through which small oil droplets pass. The small oil droplets impact the walls of the path and coalesce into larger droplets. The droplets are then re-introduced back to a sump, which generally holds excess oil in the system. Conventional cyclone separators, however, have a fixed radius and convergent nozzle and, as a result, require a high velocity to generate a sufficient centrifugal force to promote a formation of oil film from smaller droplets. Conventional cyclone separators are also known to generate a high pressure loss. Examples of cyclone separators are disclosed in U.S. Pat. Nos. 6,279,556 B1 and 6,626,163 B1 to Busen et al., both of which are assigned Walter Hengst GmbH & Co. KG.
[0005] Thus, it remains desirable to provide a cyclone oil separator that provides improved oil separation performance, lower pressure loss and greater system flexibility over conventional cyclone designs.
SUMMARY OF THE INVENTION
[0006] According to one aspect of the invention, an oil separator for removing oil from ventilation gases flowing between a crankcase and an intake manifold of an internal combustion engine. The oil separator includes a housing, a wall and a diaphragm. The housing has an inlet and an outlet. The wall is cooperative with the housing to define a path through which the gases flow between the inlet and the outlet. The wall is movably coupled to the housing to effect a change in the height of the path. The diaphragm has a movable portion coupled to the wall. The diaphragm defines a substantially closed volume. The substantially closed volume is continuous with the intake manifold so that pressure changes in the intake manifold causes corresponding displacement of the movable portion and the wall relative to the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
[0008] FIG. 1 is an exploded view of an oil separator according to one embodiment of the invention;
[0009] FIG. 2 is a cross sectional view of the oil separator in an closed position;
[0010] FIG. 3 is a cross sectional view of the oil separator in an open position;
[0011] FIG. 4 is an exploded view of an oil separator according to a second embodiment of the invention;
[0012] FIG. 5 is a cross sectional view of the oil separator of FIG. 4 shown in the closed position; and
[0013] FIG. 6 is a cross sectional view of the oil separator of FIG. 4 shown in the open position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] Referring to FIGS. 1-3 , an oil separator according to an embodiment of the invention is generally indicated at 10 . The separator 10 includes a housing 12 having first 14 and second 16 halves. Each half 14 , 16 of the housing 12 is generally cylindrical and cup shaped with a closed end 18 , 20 and an open end 22 , 24 . The first half 14 of the housing 12 has a smaller diameter than the second half 16 , so that the first half 14 can be arranged concentrically inside of the second half 16 . The first 14 and second 16 halves are arranged with the open ends 22 , 24 facing each other, such that a cavity 26 is defined between the closed ends 18 , 20 of the first 14 and second 16 halves of the housing 12 . The cavity 26 is substantially enclosed. By this arrangement, the first 14 and second 16 halves of the housing 12 can be axially displaced relative to each other in a telescopic manner. Further, the volume of the cavity 26 varies as the first 14 and second 16 halves of the housing 12 are displaced relative to each other. The housing 12 includes an outlet 30 formed in the closed end 18 of the first half 14 of the housing 12 .
[0015] A spiral shaped guide 40 extends outwardly from the closed end 18 of the first half 14 of the housing 12 toward the second half 16 . A spiral shaped wall 42 extends outwardly from the closed end 20 of the second half 16 toward the first half 14 . The housing 12 includes an inlet 32 formed in the spiral shaped wall 42 of the second half 16 . The guide 40 and wall 42 have corresponding shapes so as to divide the cavity 26 and define a continuous spiral shaped path that guides a flow of gases between the inlet 32 and the outlet 30 . The guide 40 and wall 42 are slidably engaged along an axis 44 . Optionally, a seal or gasket is provided between the guide 40 and wall 42 to prevent gases from leaking therebetween. The path has a width that decreases in size between the inlet 32 and the outlet 30 . Preferably, the width of the path between the inlet 32 and the outlet 30 decreases at a constant rate. The function of the spiral path in the removal of oil from the crankshaft gases flowing between the inlet and the outlet of the housing is discussed in greater detail in co-pending U.S. patent application Ser. No. 10/961,557 filed on Oct. 8, 2004, which is incorporated herein by reference in it entirety.
[0016] The path has a height that varies within a predetermined range that corresponds with sliding movement of the wall 42 relative to the guide 40 along the axis 44 . More specifically, sliding the guide 40 and wall 42 apart increases the height and volume of the path, thereby increasing the amount of gases that can flow therethrough under a fixed pressure. Sliding the guide 40 and wall 42 toward each other decreases the height and volume of the path, thereby increasing flow speed under a fixed pressure drop condition.
[0017] The oil separator 10 also includes a cap 50 and a flexible diaphragm 52 . The cap 50 and diaphragm 52 are each cup shaped with frustoconical walls. The cap 50 and diaphragm 52 are arranged in an inverted or opposed manner relative to each other to define a substantially closed volume or cavity 54 therebetween. The cap 50 is fixedly secured to the housing 12 by a rigid L-shaped bracket 55 . The diaphragm 52 includes a movable portion or end 56 coupled to the wall 42 . The diaphragm 52 is made from an elastomeric material so as to be deformable between an closed position, as shown in FIG. 2 , and an open position, as shown in FIG. 3 . Deformation of the diaphragm 52 between the closed and open positions causes substantially linear displacement of the end 56 of the diaphragm 52 along the axis 44 . Optionally, the diaphragm is provided in the form a plurality of rigid shells arranged concentrically for telescopic movement between the open and closed position. Optionally, the diaphragm is provided in the form of a cylinder/plunger arrangement, wherein the plunger is slidably supported within the cylinder for movement between the closed and open positions. Optionally, the cap is integrally formed with the diaphragm, such that the diaphragm defines the substantially closed cavity.
[0018] A biasing member 60 is continuously energized between the cap 50 and the diaphragm 52 to bias the end 56 of the diaphragm 52 toward the closed position. Preferably, the biasing member 60 is a helical coil spring. Optionally, a washer 57 is disposed between the end 56 of the diaphragm 52 and the biasing member 60 . The washer 57 includes a boss to keep the biasing member 60 centered on the end 56 of the diaphragm 52 .
[0019] A conduit 58 is coupled between the cap 50 and the intake manifold (not shown) so that the cavity 54 of the diaphragm 52 is open with an atmosphere defined by the intake manifold. The diaphragm 52 stays in the closed position while the pressure of the cavity 54 remains above a threshold amount. The threshold amount is related to the predetermined spring rate of the biasing member 60 . That is, it is possible for the pressure to be below ambient pressure, while the biasing member 60 maintains the end 56 of the diaphragm 52 in the closed position.
[0020] Typically, a vacuum is created in the intake manifold and cavity 54 due to decreased engine speed. The diaphragm 52 begins to deform and collapse toward the open position when the pressure in the cavity 54 falls below the threshold amount. The extent of the deformation of the diaphragm 52 and resulting displacement of the end 56 of the diaphragm 52 is proportional to the amount of change in the pressure below the threshold amount. Thus, low engine speeds will result in the formation of a large vacuum or pressure drop in the intake manifold and cavity 26 . In turn, the large pressure drop below the threshold amount causes a large displacement of the end 56 and wall 42 along the axis 44 away from the guide 40 . Displacement of the wall 42 away from the guide 40 increases the height of the path, thereby allowing decreased gas flow velocity between the inlet 32 and outlet 30 of the housing 12 . The increased capacity of the path between the inlet 32 and outlet 30 , therefore, accommodates the decreased demand from the PCV valve.
[0021] Increased engine speeds results in a pressure drop decrease between manifold and cavity 26 , which tends to expand the cavity 54 and displace the end 56 of the diaphragm 52 toward the closed position. It should be appreciated that pressure increase means positive change in the pressure, although the resulting pressure may still be below ambient, i.e. a vacuum may still exist in the cavity 54 . Displacement of the diaphragm 52 toward the closed position shortens the path between the inlet 32 and outlet 30 , as the wall 42 is moved toward the guide 40 . The shortened path allows increased gas flow velocity between the inlet 32 and outlet 30 of the housing 12 for improving oil droplet capturing function. The capacity of the path between the inlet 32 and outlet 30 , therefore, increases device efficiency in response to the decreased functionality of PCV valve.
[0022] Referring to FIGS. 4-6 , a second embodiment of the oil separator is generally indicated at 110 , wherein like components are referenced by numerals offset by 100 . The oil separator 110 includes an impact plate 70 , a guide plate 72 and a wall 74 . The impact plate 70 , guide plate 72 and wall 74 are each planar and substantially parallel to each other. The guide plate 72 is disposed between the impact plate 70 and the wall 74 . The guide plate 72 includes a plurality of holes 76 allowing gases to flow between the inlet 132 and outlet 130 of the housing 112 . Each of the plurality of holes 76 has a predetermined diameter, preferably ranging between 2 and 4 mm. The wall 74 is slidably coupled to the housing 112 and coupled to the end 156 of the diaphragm 152 for movement along a linear path between the closed position, as shown in FIG. 5 , and the open position, as shown in FIG. 6 .
[0023] In the closed position, the wall 74 prevents the flow of gases through all except at least one of the plurality of holes 76 , therefore to increase gas flow velocity to improve oil droplet capturing efficiency. Sliding the wall 74 to the open position reveals all of the plurality of holes 76 allowing increased gas flow through the guide plate 72 when enough flow rate is achieved to main consistent oil droplet capturing efficiency at different engine operating conditions. The plurality of holes 76 are arranged in rows normal to the linear path of the wall 74 , such that movement of the wall 74 toward the open position reveals successive rows of holes 76 . In either position, gases flow through the guide plate 72 and toward the impact plate 70 . A high velocity impact region is formed at the impact plate 70 as gases are redirected around the impact plate 70 and toward the outlet 130 . The high velocity impact region promotes coalescence due to impact and removal of oil from the gas flow.
[0024] The invention has been described in an illustrative manner. It is, therefore, to be understood that the terminology used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the invention are possible in light of the above teachings. Thus, within the scope of the appended claims, the invention may be practiced other than as specifically described. | An oil separator that removes oil from ventilation gases flowing between a crankcase and an intake manifold of an internal combustion engine. The oil separator includes a housing, a wall and a diaphragm. The housing has an inlet and an outlet. The wall is cooperative with the housing to define a path through which the gases flow between the inlet and the outlet. The wall is movably coupled to the housing to effect a change in the height of the path. The diaphragm has a movable portion coupled to the wall. The diaphragm defines a substantially closed volume. The volume is open with the intake manifold so that pressure changes in the intake manifold causes corresponding displacement of the movable portion and the wall relative to the housing. | 5 |
BACKGROUND OF THE INVENTION
The present invention generally relates to culvert structures and, more specifically, to low head room culvert structures made up of a series of shallow arch-shaped corrugated sections secured together and secured to base receiving channels.
The culvert structure of the present invention incorporates improvements over culvert structures of the past, such as the one disclosed in U.S. Pat. No. 4,141,666 issued in the name of DeGraff, the disclosure of which is hereby incorporated by reference herein. The DeGraff patent discloses a culvert structure having a plurality of corrugated curved sections secured together and secured into a base receiving angle as shown in FIG. 2 of that patent. This patent further discloses a series of outer reinforcing ribs which are likewise curved to conform to the outer surface of the culvert.
Box culverts or low head room culverts have found success in the marketplace as they are generally faster and easier to install than, for example, cast in place concrete. No forms or curing time is necessary and large installation crews are likewise unnecessary. In addition, box culverts use more mass produced, standard components, and therefore material costs are generally lower than with alternative structures. For these reasons and others, box culverts have provided practical and cost efficient solutions for such applications as small bridge replacement.
Despite the success of conventional box culvert structures, the areas of component standardization and material costs are of continuing concern and in need of improvement. Specifically, the receiving angles used in the past for box culverts commercialized by the assignee of the present invention have been required to accommodate box culverts having side walls extending upwardly at various angles to horizontal. As a result, two different receiving channels have been manufactured and stocked, each being generally L-shaped but one being angled at 90° and one being angled at 80°. The manufacture and stocking of two separate parts increases the overall material and inventory costs.
Another problem related to standardization of components and material costs concerns the attachment and configuration of reinforcement ribs on the separate corrugated sections which form the overall box culvert structure. With reference to FIG. 3, culvert sections 10 have been assembled with reinforcement ribs 12 bolted to the outer surface by nut and bolt assemblies 14 and spaced from each other by, for example, 18 inches, Also, a series of bolt holes 16 were punched along opposite side edges 18 of section 10 to receive nut and bolt assemblies (not shown) for securing adjacent culvert sections to each other. These bolt holes were spaced about nine inches from the adjacent reinforcement ribs 12, Thus, when additional culvert sections 10 were attached along edges 18 of section 10, the ribs of adjacent sections were likewise spaced 18 inches apart. Although this system allowed the stocking of standard components, i.e., sections 10, it required numerous relatively expensive heavy duty nut and bolt assemblies for bolting ribs 12 to sections 10, as well as for separately bolting adjacent sections 10 together along edges 18.
It would therefore be desirable to even further standardize the components making up box culvert structures and to further reduce the numbers of components and material costs associated with such culverts.
SUMMARY OF THE INVENTION
The present invention generally provides improvements related to the standardization of components and reduction in materials cost associated with box culverts. Specifically, in a first aspect of this invention, a single receiving channel is provided and specially designed to accommodate lower edge portions of box culverts extending at different angles relative to horizontal, In the preferred embodiment, the receiving channel is designed for receiving the lower edge of a box culvert at various angles relative to horizontal. The receiving channel of the invention includes a lower horizontal base, a lip extending upwardly along an outside edge for containing the box culvert within the channel and a taller curved member extending upwardly from the other edge of the base for supporting the box culvert at one of a plurality of angles. Fasteners, such as nuts and bolts, are used to secure the lower edge of the box culvert to the inside surface of the curved member.
In a second aspect of this invention, a culvert section is provided which reduces the material and manufacturing costs associated with the prior art culvert section mentioned above. Specifically, a culvert section of the present invention includes one less row of bolt holes and nut and bolt assemblies, yet still retains the same number of reinforcement ribs spaced the same distance apart when adjacent sections are bolted together. Specifically, while five rows of bolts and holes were required in the prior culvert section, for example, only four are necessary with the present invention. Ribs are fastened to opposite edges of the section and the same bolts are used to fasten adjacent edges of sections together. This has reduced both the manufacturing costs associated with the sections themselves since one less row of holes needs to be punched in each section and has also eliminated the need for one complete row of nuts and bolts associated with each section. These cost reductions can be significant considering the size and length of many box culvert structures.
Additional advantages of the invention will become more readily apparent to those of ordinary skill upon review of the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a box culvert structure constructed in accordance with the present invention;
FIG. 2A is an enlarged view of the base of the box culvert as viewed along line 2--2 of FIG. 1 and showing the receiving channel of the present invention supporting the lower edge of the box culvert at a first angle α;
FIG. 2B is a view similar to FIG. 2A, but showing the receiving angle supporting the lower edge of the box culvert at a second angle β;
FIG. 3 is a developed top view of a culvert section of the prior art flattened out and not showing the conventional corrugated structure;
FIG. 4 is a developed top view similar to FIG. 3 but showing a culvert section and outer reinforcement rib configuration of the present invention; and
FIG. 5 is a developed top view schematically showing a plurality of culvert sections as shown in FIG. 4 bolted together as they are to form a box culvert according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, a low head room culvert or box culvert 20 constructed in accordance with the present invention is shown and is generally manufactured from corrugated aluminum plate material 22 which has been formed into the curved shape shown. Although a single piece structure has been shown in FIG. 1 for clarity, the structure may be formed from separate corrugated plate sections as will be described further below. Not only are these plate sections overlapped and bolted together to form the culvert 20 with a desired length, but separate plate sections are also generally used to form the overall, curved cross-sectional shape of the culvert 20. In this regard, generally to form the entire cross-sectional shape, two curved side wall pieces are used and connected with an upper slightly curved top piece by bolts or other fasteners.
As also shown in FIG. 1, outer reinforcement ribs 24, 26 are also often used along the length of culvert 20 for applications requiring that culvert 20 have additional strength. Like culvert sections 22, each reinforcement rib 26 preferably is formed by three separate ribs 24a, 24b, 24c and 26a, 26b, 26c. The number of ribs 24, 26 will depend on the specific strength requirements of the application as well as the length of culvert 20, and only two are shown in FIG. 1. Ribs 24, 26 may be spaced from one another by, for example, 18 inches.
Still referring to FIG. 1, in many applications it is desirable to rigidly fix the base of the culvert to footing pads 28, 30 which may be formed of concrete. For this purpose, and in accordance with one aspect of the invention, an identical receiving channel or angle 32 is provided on each side of culvert 20, with each receiving channel 32 receiving and securing one longitudinal lower edge of culvert 20. As will be described further below, culvert 20 is secured to each receiving channel 32 by a plurality of fastener assemblies 34. Fill material 36, such as soil, is generally used to stabilize and secure the entire culvert structure 20 in place.
Referring now to FIGS. 2A and 2B, a universal receiving channel 32 constructed in accordance with the present invention is shown being used in two separate applications. Specifically, in FIG. 2A, receiving channel 32 receives a culvert section 22 which extends into receiving channel 32 at an angle α, which may be 80° relative to horizontal, or in other words, relative to the upper surface of footing pad 28. In FIG. 2B, an alternatively designed culvert section 22' extends into the same receiving channel 32 at an angle β which is 90° to horizontal or to the upper surface of footing pad 28.
In each of these applications, receiving channel 32 must fully support and secure the lower edge of culvert 20. The reason that receiving channel 32 of the present invention can secure the lower edge of either culvert section 22 or 22' relates to the cross-sectional shape of receiving channel 32. In this regard, receiving channel 32 includes an outer lip 40 and an inner curved leg 42 which each extend upwardly from a base horizontal portion 44. Base portion 44 is rigidly fixed to footing pad 28 or 30. Lip 40 preferably extends vertically upward with respect to base 44 while curved leg 42 curves generally outwardly from a lower edge thereof to an upper edge thereof and with respect to the interior of channel 32 which receives culvert section 22 or 22'. As will be appreciated from a review and comparison of FIGS. 2A and 2B, in each application a support surface area is provided on the inner surface of curved leg 42 when fastener assembly 34, and specifically nut 46 and bolt 48, are tightened as shown. In each application, there is surface area contact made as shown at 50 in FIG. 2A and 52 in FIG. 2B. Furthermore, upwardly extending lip 40 provides additional retaining structure for either culvert section 22 or 22'.
Referring to FIG. 4, another aspect of this invention relates to the reconfiguration of reinforcement ribs on each culvert section 22 with respect to the prior configuration shown in FIG. 3. In this regard, and as explained previously with regard to FIG. 3, it is generally desirable to space reinforcement ribs equidistantly along the entire length of culvert 20 (FIG. 1). In the example given, a spacing of 18 inches is used. Previously, as explained with respect to FIG. 3, one practice was to provide separate bolt holes 16 along each side each of a culvert section 10. Ribs 12 were bolted nine inches from each edge such that a spacing of 18 inches resulted when two culvert sections 10 were fixed together. As shown in FIG. 4, and in accordance with the present invention, the same spacing is provided between reinforcement ribs 54 while eliminating the need for one entire row of nut and bolt assemblies 60. Comparing FIGS. 3 and 4, it will be recognized that four rows of bolt holes are necessary in the present invention as opposed to five rows in the previous design. Each of the rows of bolt holes 62 (with three rows shown in FIG. 4 as having ribs 54 secured thereto) are spaced equidistant from each other and at the intended spacing of ribs 54. Thus, as shown in FIG. 5, when culvert sections 22 are overlapped at their edges and nut and bolt assemblies 60 are used to secure both ribs 54 to each culvert section 22 and, along the edges, to secure both ribs 54 to culvert sections 22 and adjacent culvert sections 22 to each other, proper rib spacing is achieved with a much lower overall number of nut and bolt assemblies 60 required. Also, as only four rows of bolt holes 62 need to be punched in each culvert section 22, lower manufacturing costs result.
While a detailed embodiment of the present invention has been described fully above, applicant does not intend to be bound by the details provided but only by the scope of the appended claims. Additional modifications and substitutions will become readily apparent to those of ordinary skill upon review of this detailed description without departing from the spirit and scope of the invention. | A box culvert formed from a plurality of corrugated sections. Reinforcing ribs are secured to the outside surface of the culvert. A universal receiving channel is provided for each lower edge of the culvert and may be used to secure lower edge portions extending at different angles relative to horizontal. A rib configuration is disclosed which results in manufacturing and material savings. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 USC §119(e) of U.S. Provisional Application Ser. No. 60/868,429, having a filing date of Dec. 4, 2006 and claims the benefit under 35 USC §119(a)-(d) of French Application No. 06.53266, filed Aug. 3, 2006, the entireties of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of magnetic materials, more especially those intended to be used firstly in non-volatile random-access magnetic memories used to store and read data in electronic systems and secondly in the field of radio-frequency oscillators that use magnetic thin-film systems technology.
BACKGROUND OF THE INVENTION
[0003] In the field of magnetic memories, so-called M-RAM (Magnetic Random Access Memory) consisting of a magnetic tunnel junction have attracted considerable interest ever since the development of such tunnel junctions which have high magnetoresistance at ambient temperature. These random-access magnetic memories have many significant advantages:
[0004] speed (write and read times of just a few nanoseconds);
[0005] non-volatile;
[0006] no read/write fatigue; and
[0007] unaffected by ionising radiation.
[0008] This being so, they are increasingly replacing memory that uses more conventional technology based on the charge state of a capacitor (D-RAM, S-RAM, FLASH).
[0009] In these magnetic memories, coding of information (“0” or “1”) depends on the relative orientation (parallel or antiparallel) of the magnetisation of two magnetic layers having different coercivities, one of the layers being “free”, i.e. having a magnetisation direction that can be modified by applying an external low-intensity magnetic field and the other layer being referred to as “anchored”, i.e. having a magnetisation direction that is unaffected by said external magnetic field.
[0010] This change in the relative orientation of magnetisation directions modifies the electrical resistance of the stack of two layers thus formed and the magnetic state is read by measuring an electric voltage after injecting an electric current in a direction that is perpendicular to the plane of the layers.
[0011] Generally speaking, information is written by sending two electrical pulses via conductors that intersect at a right angle close to the point where the memory cell in question is located. Adding the two magnetic fields created by these electrical pulses at the level of the cell and the direction of the electric currents injected makes it possible to change the magnetisation direction of the “free” layer, thus writing the information in question.
[0012] However, the existence of relatively widely distributed switching fields of all the memory cells due to the method of fabrication makes it necessary, in order to ensure a change in the orientation of magnetisation, to use an external magnetic field that is higher than the highest switching field of said distribution. This being so, there is a risk of inadvertently reversing certain memory cells located on the corresponding row and/or column having a switching field, possibly located in the lower part of the distribution, that is weaker than the magnetic field generated by the row or column alone.
[0013] If one wants to make sure that no memory cell can be written by one row or column alone, the write current must be limited so that it never exceeds, for these memory cells, the magnetic field that corresponds to the lower part of the distribution with the risk of not writing the selected memory cell at the intersection of said rows and columns if the switching field for that memory location is in the upper part of the distribution. In other words, this architecture with selection by magnetic fields using rows and columns of conductors can easily result in write addressing errors.
[0014] In addition, it has generally been observed that the average value of the switching field increases as the size of the memory cells decreases. This being so, a stronger electric current is required in order to ensure actual switching of the magnetisation of the memory cell and this consequently entails an increase in the required electric power.
[0015] Because of this, another write technique referred to as “magnetisation switching by spin-polarised current” has been proposed. This technology involves writing memory cells by using a spin-polarised electric current rather than an external magnetic field. In fact, it has been demonstrated that a spin-polarised current is capable of causing precession or even reversal of magnetisation by spin angular momentum transfer between polarised carriers and the magnetic moment of the layer in question (see U.S. Pat. No. 5,695,864, for example).
[0016] One of the advantages of this technique is the fact that the same current row is used for both reading and writing the magnetic information and this simplifies the architecture of the device considerably. Thus, as it passes through the various layers of the magnetic stack in question, the electric current is polarised and the electron spin tends to align itself with the local magnetisation direction. If there is no depolarisation in the layers through which the current passes, this polarisation is maintained in the second magnetic layer and in turn induces precession of the magnetisation of the so-called “free” magnetic layer around the polarisation direction.
[0017] If the electric current density increases, the angle of the precession cone increases until it eventually exceeds 90° for a certain critical current, thus causing the magnetisation of the “free” layer to flip to a direction that is opposite to its initial direction.
[0018] Nevertheless, this particular technology is hampered by one serious limitation. In fact, in this configuration, in order to achieve magnetisation reversal, it is necessary to overcome the demagnetising field of said “free” layer. For thin magnetic films, this demagnetising field tends to hold magnetisation in the plane of said layer. Because this demagnetising field is proportional to the magnetisation of the material, it is obvious that magnetisation reversal makes it necessary to inject a high-intensity current which is capable of damaging the device, especially by causing electric breakdown of the insulating barrier that separates the two magnetic layers in the case of a magnetic tunnel junction.
[0019] Magnetic thin-film systems are also used in the field of radio-frequency oscillators. RF oscillators have undergone considerable development directly associated with corresponding development of mobile telephony. In fact, mobile telephony has brought about the use of oscillators having a very wide frequency band with especially good jitter performance and hence a high quality factor.
[0020] One technical solution to meet this demand is to use electron-spin based radio-frequency oscillators. Using such oscillators makes it possible to obtain a wide frequency band with a high quality factor Q and straightforward frequency tunability and, moreover, to use a relatively simple architecture.
[0021] Spin polarisation of an electric current which causes magnetoresistive phenomena in magnetic multilayers such as giant magnetoresistance and tunnel magnetoresistance is known. In addition, when it passes through a magnetic thin layer, such a spin-polarised current can affect the magnetisation of a magnetic nanostructure by inducing reversal of its magnetisation in the absence of any external magnetic field or by generating sustained magnetic excitation also referred to as oscillations. The frequency of this excitation depends, in particular, on the density of the current that flows through the nanostructure.
[0022] Using the effect of generating sustained magnetic excitation in a magnetoresistive device makes it possible to convert this effect into electrical resistance modulation that can be directly used in electronic circuits with the consequent possibility of acting at the level of frequency.
[0023] However, one of the problems encountered with these radio-frequency oscillators is the density of the spin-polarised current that has to be injected into the magnetic system in question and which is capable of causing damage to the device due to breakdown or electromigration phenomena.
[0024] Regardless of the prospective application, in order to reduce the current densities required to write information, attempts are always made to obtain a thin-layer magnetic material whose magnetisation is spontaneously parallel to the plane of that layer but can easily be oriented in a perpendicular direction by the effect of a low-amplitude magnetic field (or polarised current) or a thin-layer magnetic material whose magnetisation is spontaneously (without any external magnetic field or polarised current) perpendicular to the plane of that layer.
[0025] For this purpose, the reader is reminded of the physical principles that underlie these phenomena. For a single magnetic layer, i.e. for example a thin layer of magnetic material deposited on a substrate where there is no particular interaction with said layer, the form effect (the fact that the lateral dimensions of this layer are much larger than its thickness) tends to keep its magnetisation direction in plane (so-called “planar” magnetisation).
[0026] If a magnetic field of increasing amplitude is applied in a direction perpendicular to the plane of this layer, the direction of its magnetisation will gradually exit this plane and orient itself parallel to the applied field. It will therefore be perpendicular to the plane when the applied magnetic field reaches a perpendicular saturation field value H sp equal to a so-called “demagnetising field” H dm that is proportional to the magnetisation per unit of volume M s of this magnetic material in accordance with the following equation:
H sp =H dm =4πM 5 .
[0027] To give some idea of values, this field H sp is of the order of 18 kilo-oersteds (kOe) for a material such as cobalt and 6 kOe for nickel. The first way of reducing this field H sp is therefore to use a weakly magnetic material. However, this may be disadvantageous for some applications in which the wanted signal depends on this magnetisation.
[0028] A second way of reducing H sp is to introduce an additional term of opposite sign to H dm . This so-called “perpendicular anisotropy” term H ap may, as indicated in the rest of this explanation of the prior art, be the result of volume anisotropy of magnetocrystalline origin or induced by elastic growth strains or it may be interface anisotropy due to interfacial electronic interactions. The influence of a layer of platinum in contact with a magnetic layer of cobalt, nickel or iron is a typical case, for example.
[0029] When this additional term is present, the perpendicular saturation field can be expressed as follows:
H sp =H dm −H ap .
[0030] Qualitatively, the perpendicular saturation field H sp will therefore reduce uniformly as H ap increases, the magnetisation of the magnetic layer always being parallel to the plane until it approaches zero, the limit beyond which, when H ap exceeds H dm , magnetisation of the magnetic layer will spontaneously (i.e. without any applied magnetic field) be perpendicular to the plane of the layer.
[0031] It must also be noted that, in the case of perpendicular anisotropy of interfacial origin, H ap will, as an initial approximation, be inversely proportional to the thickness e of the magnetic layer in accordance with:
H ap =C+K ap /e
where C is a constant that depends on the volume properties of the magnetic layer and where K ap , the perpendicular anisotropy constant, depends on the intimate structure of the material in contact with the magnetic layer and the structural quality of the interface.
[0032] This dependence of the perpendicular anisotropy field on the thickness of the magnetic layer therefore indicates that it will only be possible to stabilise magnetisation in a direction that is perpendicular to the plane for thin magnetic-layer thicknesses and, conversely, that the critical perpendicular/planar transition thickness increases with the amplitude of K ap .
[0033] The first object of the invention in relation to applications of the RF oscillator or MRAM memory type is to propose a means of producing a magnetic layer with magnetisation perpendicular to the plane of that layer which can be integrated in spin valve or tunnel junction type structures having free and anchored layers with planar magnetisation. This additional magnetic layer with perpendicular magnetisation is intended to be used as a “polarizer” (see U.S. Pat. No. 6,532,164).
[0034] In such a “polarizer”, the spin of the current electrons injected into the magnetic system is coupled with magnetisation in a direction perpendicular to the plane of the layers and the axis of the magnetisation precession cone is therefore also perpendicular to this plane. For weak currents, magnetisation of the “free” magnetic layer rotates in a plane that is practically identical to the plane of the layers.
[0035] The use of syncronised current pulses and the uniaxial planar magnetic anisotropy of the “free” layer make it possible to reverse the magnetisation direction easily by causing it to perform a half precession cycle in the plane of the layer.
[0036] The use of such a polarizer in the production of radio-frequency oscillators is also especially sought-after. In such a configuration, the spin-polarised current is injected continuously through the stack rather than as pulses. This being so, the precession motion of the magnetisation is sustained rather than resulting in half precession for a write operation in the case of a magnetic memory.
[0037] If the magnetisation that processes is that of the free (or soft) layer of a tunnel junction deposited on top of the polarising layer, this precession movement results in oscillating variation of the resistance of the stack due to the tunnel magnetoresistance effect of the junction. This results in the appearance of an oscillating voltage between the two opposite-facing surfaces of the stack, this voltage can be used to produce a tunable radio-frequency oscillator with the frequency being directly related to the intensity of the injected current.
[0038] It is important to note that, in order for them to operate, the magnetic layers with perpendicular magnetisation must not contain any materials that have a strongly depolarising effect on the electrons in the vicinity of the active area of the structure.
[0039] By way of example, in the case of the perpendicular polarizer mentioned above, inserting a thin layer of platinum between this polarizer and the two magnetic layers of the spin valve or magnetic tunnel junction type structure would completely destroy the polarisation of electrons brought about by this polarizer. In the rest of this document, the term “effective” magnetic thickness will be used to denote the thickness of the magnetic layer with perpendicular magnetisation, considered relative to the direction of travel of the electrons, beyond any final layer of strongly depolarising material such as platinum, palladium or gold.
[0040] Another object of the invention in relation to MRAM type applications is to propose a means of producing thin magnetic layers that can be integrated in spin valve or magnetic tunnel junction type structures having perpendicular magnetisation where the magnetisations of the two active magnetic layers (anchored layer and free layer) are perpendicular to that plane.
[0041] A third object of the invention is to propose a means of producing a magnetic layer with planar magnetisation, i.e. magnetisation located in the plane of the layers that constitute it, for which its demagnetising field is partially compensated by a perpendicular anisotropy term, thus making it possible to reduce the density of the current required to switch the magnetisation of that layer. This magnetic layer may, for instance, be used as a free layer in spin valve or tunnel junction type structures with planar magnetisation.
[0042] Various methods have been proposed in order to produce thin magnetic layers with magnetisation perpendicular to their plane and capable of being used in some of the types of applications mentioned above.
[0043] Producing cobalt/nickel multilayers by vapour deposition on a buffer layer of gold covering the substrate has been proposed (Daalderop, Kelly and den Broeder, Physical Review Letters 68, 682, 1992). The operating window is relatively narrow (for example, for a cobalt thickness of 0.4 nm, the nickel layers must be 0.6 to 0.8 nm thick). Not only that, according to the authors, the result obtained depends critically on preparation conditions.
[0044] Adopting a similar approach, Ravelosona et al (Physical Review Letters 95, 117203, 2005) have proposed a combination of (cobalt/platinum)/(cobalt/nickel) multilayers, also prepared by vapour deposition. In this case, the effective magnetic thickness (i.e. above the final layer of platinum) is extremely small and equivalent to approximately 1.0 nm of cobalt.
[0045] In both these cases it seems necessary to grow the magnetic layers by vapour deposition, a technique that is not very compatible with industrial fabrication. The reason for this is that this perpendicular magnetic anisotropy property is due to the effects of elastic strain between the layers of nickel and cobalt which have crystalline parameters that are slightly different. This explains both the need to use such a preparation technique as well as the difficulty in producing such structures. In any case, any possibility of production on an industrial scale using this technology can be ruled out, at least at acceptable cost. In addition, these elastic strain effects only occur for certain crystalline magnetic materials. There is therefore no possibility, for example, of using other magnetic materials or amorphous magnetic alloys.
[0046] U.S. Pat. No. 6,835,646, which deals with structures of the substrate/buffer layer/Ni/FeMn/Cu type, proposes a method whereby growth of the nickel must be epitaxial. This means that the layers that are successively deposited must adopt the symmetry and inter-atomic distance of the underlying layers. In addition, the buffer layer must be made either of monocrystalline copper with crystallographic orientation (002) or diamond with crystallographic orientation (001). This can only be obtained by growth on a monocrystalline silicon substrate with crystallographic orientation (001) and chemical cleaning, moreover, in order to obtain satisfactory orientation of the copper or diamond buffer layer.
[0047] This production method is especially onerous to use because of the epitaxial growth and the monocrystalline nature of the substrates. In addition, no magnetic material other than nickel would give the hoped-for result.
[0048] Nishimura et al (Journal of Applied Physics 91, 5246, 2002, U.S. Pat. No. 6,844,605) have proposed another production method using structures based on rare earth metals of the GdFeCo/CoFe/Al 2 O 3 /CoFe/TbFeCo type, with “effective” thicknesses of magnetic metal (cobalt-iron alloy) of the order of 1 nm.
[0049] This production method involves using alloys based on metals in the rare earth family (gadolinium, terbium) that are known to be highly polluting and are prohibited in the industry.
[0050] It is evident from the foregoing considerations that none of the proposed solutions can be used to produce, using conventional magnetic materials and a simple preparation method, thin layers with magnetisation perpendicular to their plane and having a sufficient “effective” magnetic thickness for the applications in question.
[0051] In fact, the magnetic thicknesses that one manages to achieve are either too small to provide exploitable polarisation of the electric current that flows at right angles to the plane of the layers or it is necessary to use a specific magnetic material deposited using a very special method in order to achieve larger magnetic thicknesses.
SUMMARY OF THE INVENTION
[0052] The invention firstly relates to a thin-film magnetic device comprising, on a substrate, a composite assembly deposited by cathode sputtering and consisting of:
[0053] a first layer made of a ferromagnetic material with a high rate of spin polarisation, the magnetisation of which is in plane in the absence of any electric or magnetic interaction;
[0054] a second layer made of a ferromagnetic material with high perpendicular anisotropy, the magnetisation of which is outside the plane of said layer in the absence of any electric or magnetic interaction, and coupling of which with said first layer induces magnetisation of the device located outside the plane of the layers and/or a decrease in the effective demagnetising field of the entire device; and
[0055] a third layer that is in contact with the first layer via its interface opposite to that which is common to the second layer and made of a material that is not magnetic and not polarising for electrons passing through the device.
[0056] The device also comprises means of causing an electric current to flow through it substantially perpendicular to the plane of the layers.
[0057] According to the invention, said first layer consists of a magnetic material selected from the group comprising cobalt, iron, nickel or binary alloys thereof such as, for instance, Permalloy Ni 80 Fe 20 , or ternary alloys as well as magnetic, crystallised or amorphous alloys also containing one or more of the magnetic elements cited, and added non-magnetic materials such as, for instance, boron, silicon, phosphorous, carbon, zirconium, hafnium or alloys thereof.
[0058] However, this first layer may also consist of a multilayer of the magnetic metal/magnetic metal (e.g. Co/NiFe for instance) or magnetic metal/non-magnetic metal (Co/Cu for instance) type.
[0059] Consequently, the thickness of said first layer makes it possible to optimise the spin polarisation of an electric current passing through it.
[0060] In diffusion mode, the crucial length to produce spin polarisation is the spin-diffusion length l SF . Spin polarisation increases as function (1−exp(−e/l SF )) as a function of the thickness e of said first layer. This spin-diffusion length is typically 4.5 nm at 300 K in Permalloy Ni 80 Fe 20 , and 20 nm in cobalt. Diffusion mode is the mode encountered, for example, if the polarizer thus produced is separated from the free magnetic layer of a tunnel junction by a metallic or non-magnetic spacer with a view to producing an MRAM cell or a radio-frequency oscillator.
[0061] In tunnel mode, the polarisation of the tunnel electrons is determined by the electronic state densities in the vicinity of the tunnel barrier. The optimum thickness in order to obtain strong spin polarisation is then determined by the thickness of the magnetic layer that is in contact with the barrier which makes it possible to establish strong contrast in electron energy-state densities between spin-up and spin-down electrons close to the Fermi energy in the vicinity of the interface with the tunnel barrier. This thickness is typically several atomic planes and depends on the peak-to-valley height of the interfaces and the materials used. Another point that must be taken into account when determining the thickness of this first layer is the thermal stability of its magnetisation. An excessively fine layer (typically a thickness of less than 1 nm) may give rise to thermally activated magnetic fluctuations or even superparamagnetism phenomena that are well known to those skilled in the art.
[0062] Generally speaking, the greater the spin polarisation, the more the current density required in order to write a memory cell using such a magnetic device or to obtain a radio-frequency oscillator with a wide frequency band can be reduced.
[0063] According to the invention, the second layer may consist of an alloy or a multilayer consisting of materials selected from the group comprising cobalt, platinum, iron, nickel, palladium, gold and copper.
[0064] The nature, number and thickness of the various elementary layers that constitute said second layer are selected in order to maximise the magnetic perpendicular anisotropy energy of the assembly consisting of the first and second layers in order to obtain the desired characteristics with the maximum thickness of said first layer that is compatible with optimum polarisation of the electric current electrons passing through the structure.
[0065] According to one advantageous aspect, a so-called “buffer layer” made of one or more materials selected from the group comprising tantalum, chromium, titanium, titanium nitride, copper, gold, palladium, silver and/or alloys thereof is interposed between the magnetic device thus defined and the substrate. This buffer layer is more particularly intended to optimise growth of the first and second layers besides improving their adhesion to each other and to the substrate. It also makes it possible to enhance the flatness of said layers because of the adaptation of lattice parameters that it induces. It can also be used to supply current to the base of the device.
[0066] According to the invention, the magnetic device is topped by a third non-magnetic layer made either of metal (for example copper) or an insulator (for example silicon, magnesium or aluminium oxide). The function of this third layer is to protect the magnetic layer of the magnetic device immediately below it against corrosion and it may also be used to supply current to the top of the device. Finally, it also has to magnetically decouple said first magnetic layer from another magnetic layer that is likely to be deposited on top of said third layer, for example in the context of producing a magnetic tunnel junction or a radio-frequency oscillator.
[0067] In contrast, this third layer is selected so as not to cause any particular effect in terms of magnetic perpendicular anisotropy or in terms of polarisation of the electrons passing through the structure.
[0068] According to the invention, production of this magnetic device is achieved by depositing the various layers by cathode sputtering.
[0069] This magnetic device can advantageously be used:
[0070] as a perpendicular polarising layer inside spin valves or magnetic tunnel junctions with planar magnetisation;
[0071] as active layers, i.e. both free layer and anchored layer, in structures with perpendicular magnetisation; and
[0072] as an active layer, i.e. as a free layer with a weak magnetising field, in structures with planar magnetisation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0073] For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description of a preferred mode of practicing the invention, read in connection with the accompanying drawings in which:
[0074] FIG. 1 is a schematic view of a first embodiment of the magnetic device according to the invention;
[0075] FIG. 2 is a graph showing the variation in remanent magnetisation measured in the perpendicular field as a function of the equivalent cobalt thickness for structures of the type shown in FIG. 1 ;
[0076] FIG. 3 is a schematic view of a second embodiment of the invention;
[0077] FIG. 4 is a graph showing the variation in remanent magnetisation (measured in the perpendicular field) as a function of the equivalent cobalt thickness for the structures shown in FIG. 3 ;
[0078] FIG. 5 is a schematic view of a third embodiment of the invention;
[0079] FIG. 6 is a schematic view of a fourth embodiment of the invention;
[0080] FIG. 7 is a graph showing the variation in the saturation field (measured in the perpendicular field) as a function of the equivalent cobalt thickness that constitutes the free layer of the structure of the type shown in FIG. 6 ; and
[0081] FIG. 8 is a schematic view of a fifth embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0082] The reader is first of all reminded of the phenomenon of spin polarisation of electrons flowing in devices, especially tunnel junction or spin-valve devices.
[0083] An electric current flowing through a conductor consists of electrons, the spin of which has no reason, a priori, to be oriented in any particular direction. Nevertheless, on passing through a magnetic layer having a particular magnetisation, the spins of said electrons are oriented by magnetic-moment transfer phenomena so that the electrons have polarised spin when they emerge from this layer.
[0084] Such a layer or a set of such layers constitutes a polarizer. This phenomenon may make itself evident in terms of transmission (through a layer) as well as reflection (against certain layers) depending on the direction in which the current flows. It may also make itself evident in the opposite sense in that it allows preferential passage of electrons that have spin polarised in a certain direction. The function of the layer is then that of an analyser.
[0085] Thus, in the context of magnetic memories that are written by magnetisation switching by a spin-polarised current, when the electric current passes through a first so-called anchored layer, it is polarised in the sense that the electron spin tends to align itself with the local magnetisation direction. If no strongly depolarising layer separates this first magnetic layer from a second so called “free” magnetic layer in the sense that it has no particular magnetisation orientation, this spin polarisation of electrons in return induces precession of the magnetisation of said second free magnetic layer around the polarisation direction.
[0086] In the case of magnetic systems with planar magnetisation, if the electric current density passing through these layers increases, the angle of the precession cone increases until it eventually exceeds 90° for a certain critical current, thus causing switching of the magnetisation of the “free” layer. However, in order to achieve such flipping, it is necessary to overcome the demagnetising field of the free layer, the reader being reminded that this demagnetising field tends to hold magnetisation in-plane for thin magnetic layers.
[0087] Because this physical unit is proportional to the magnetisation of the material, magnetisation switching consequently requires the injection of high-density current for conventional magnetic materials, but tunnel junction type magnetic devices are incapable of withstanding such high-density current.
[0088] One attraction of the present invention is therefore the use of magnetic devices that, by reducing the demagnetising field, make it possible to limit these current densities in order, in the context of producing magnetic memories, to optimise their operation.
[0089] According to the invention, the magnetic device uses a current substrate which, in particular, is not necessarily monocrystalline. Such a substrate consists, for instance, of silica or oxidised silicon. This oxidation may be the result of thermal oxidation or may be caused by natural oxidation of silicon.
[0090] If it is amorphous, this substrate does not induce any preferential crystallographic growth orientation of subsequent layers. It is therefore chosen solely for its known properties such as extremely low peak-to-valley height with a view, in particular, to obtaining satisfactory flatness of upper layers.
[0091] Besides silicon and oxidised silicon, this substrate may also consist of other materials that have an extremely low peak-to-valley height such as, for example, silicon nitride or molten glass. It may also be made of alumina or magnesium oxide.
[0092] Cathode sputtering is used to deposit a buffer layer 1 on this substrate. As stated above, this buffer layer encourages the growth of upper layers, adapts lattice parameters, ensures wettability of said upper layers, as well as their adhesion and improved flatness. The purpose of this layer is also to make it possible to supply the electric current that flows through the device.
[0093] In the first embodiment of the invention, more especially shown in FIG. 1 , this buffer layer 1 consists of a thick layer of copper topped by a layer of tantalum and/or platinum. The thickness of the tantalum layer is 2 to 20 nm and advantageously 3 nm. The thickness of the platinum layer is 2 to 30 nm and advantageously 20 nm.
[0094] A layer 2 , consisting of a stack of layers of platinum and cobalt in a pattern (Pt/Co) n is then deposited where n is the number of repetitions of the platinum/cobalt stack.
[0095] The thickness of the cobalt layers of multilayer 2 (Co/Pt) n is 0.2 to 1 nm and advantageously 0.6 nm. The thickness of the platinum layers is 0.1 to 2 nm and advantageously roughly 0.3 nm. In addition, the number of repetitions of the stack n (Co/Pt) is 1 to 10.
[0096] A layer 3 made of a ferromagnetic material with a high rate of spin polarisation is then deposited on this layer 2 . In the example described, this layer 3 is made of cobalt. One can, however, advantageously substitute cobalt by another magnetic material known for its propensity to significantly polarise the electron spin of current passing through it, such as, for example, Permalloy Ni 80 Fe 20 . Another advantage of Permalloy already mentioned previously is its short spin-diffusion length (˜4.5 nm) such that, in diffusion mode, a Permalloy thickness of the order of 4.5 nm is sufficient to generate the maximum polarisation that can be expected from this material (of the order of 50 to 60%).
[0097] This layer 3 can be made of a binary or ternary magnetic alloy of elements selected from the group comprising cobalt, iron and nickel. This alloy may also be crystallised or amorphous and contain added non-magnetic materials selected from the group comprising boron, silicon, phosphorus, carbon, zirconium, hafnium or alloys thereof. This layer 3 may also consist of a magnetic metal/magnetic metal or magnetic metal/non-magnetic metal type multilayer.
[0098] This layer 3 has magnetisation that is naturally oriented in its plane when it is not coupled with the preceding layer 2 .
[0099] Finally, a layer of copper 4 having a thickness of 2 to 10 nm is deposited on layer 3 , also by cathode sputtering. The ultimate purpose of this layer 4 is to protect layer 3 against corrosion, without inducing any particular effect both in terms of out-of-plane anisotropy of layer 3 and in terms of depolarisation of electrons passing through the structure.
[0100] This layer 4 is also intended to magnetically decouple layer 3 from other magnetic layers that are likely to be deposited on top of said third layer, such as, for example, adding a tunnel junction with a view to producing an MRAM cell or a radio-frequency oscillator. This layer of copper may also be replaced by a layer of silicon, aluminium or magnesium oxide or of any other material or alloy that does not cause excessive depolarisation of electrons.
[0101] The purpose of multilayer 2 is, thanks to its high perpendicular magnetic anisotropy, to pull the magnetisation of cobalt layer 3 out of plane. To achieve this, it has been demonstrated that the respective thicknesses of these two layers should be selected so that the absolute value of the effective anisotropy of the (Co/Pt) n multilayer exceeds the absolute value of the effective anisotropy of the cobalt layer.
[0102] The following phenomena are described in order to illustrate this statement.
[0103] If the magnetisation of multilayer 2 is m 2 , if its thickness is e 2 and if the magnetisation of cobalt layer 3 and its thickness are m 3 and e 3 respectively, this gives the following equations:
[0104] Firstly, the anisotropy per unit of surface area of each of these two layers is defined as the sum of the magnetocrystalline anisotropy and the interfacial anisotropy. Thus, for layer 2 , the effective anisotropy per unit of surface area k eff2 is defined by the following equation:
k eff2 =k v2 ·e 2 +k s2
where k v2 and k s2 are the magnetocrystalline anisotropy and the interfacial anisotropy respectively of multilayer 2 .
[0105] Similarly, the following equation applies to cobalt layer 3 :
k eff3 =k v3 ·e 3 +k s3
where k v3 and k s3 are the magnetocrystalline anisotropy and the interfacial anisotropy respectively of the cobalt layer.
[0106] Another factor that must be taken into consideration is shape anisotropy which tends to maintain in-plane magnetisation of the layer in question in order to minimise magnetostatic energy and is equivalent to the demagnetising field. Shape anisotropy per unit of surface area is expressed respectively as follows:
[0107] for layer 2 : −2π· M 2 2 ·e 2 ;
[0108] and for layer 3 : −2π·M 2 3 ·e 3
[0000] where M 2(3) is the spontaneous magnetisation of the corresponding layer.
[0109] Finally, A is the exchange coupling constant at the interface between multilayer 2 and cobalt layer 3 .
[0110] The anisotropy energy per unit of surface area of multilayer 2 is then:
E =−[( k v2 −2 πM 2 2 ) e 2 +k s2 ] cos 2 θ 2
where θ 2 is the magnetisation angle of layer 2 relative to the direction that is perpendicular to the plane of the layers.
[0111] As a result of this expression, in order to make sure that layer 2 has resultant out-of-plane magnetisation in the absence of interaction with any other layer, one must check the relation [(k v2 −2π·M 2 2 )e 2 +k s2 ]>>0, so that energy [(k v2 −2π·M 2 2 )e 2 +k s2 ] cos 2 θ 2 is minimised for θ 2 =0, i.e. for out-of-plane magnetisation.
[0112] To achieve this, the thickness of multilayer 2 must be sufficiently small (i.e. the number of repetitions n in particular) for shape anisotropy not to reduce interfacial perpendicular anisotropy excessively.
[0113] Experience demonstrates, however, that this material—the cobalt/platinum multilayer in the example described—produces excessively weak spin polarisation; any polarisation obtained when electrons pass through a cobalt layer is practically lost when they pass through the next platinum layer. In order to increase this polarisation, this multilayer is coupled with a thicker layer of magnetic metal which, in a known manner, has strong spin polarisation.
[0114] In fact, the cobalt mentioned in the example can advantageously be replaced, as was stated above, by a Permalloy Ni 80 Fe 20 or cobalt-iron CoFe alloy. However, the magnetisation direction of these materials, in the absence of coupling with layer 2 and parallel to the plane, is in accordance with the following expression:
[( k v3 −2π M 2 3 ) e 3 +k s3 ]<0.
[0115] But exchange coupling between the magnetisations of layers 2 and 3 , in accordance with the expression−A cos(θ 2 −θ 3 ), in which θ 2 and θ 3 are the respective magnetisation angles of each of the two layers relative to the direction that is perpendicular to the plane of the layers, tends to keep the magnetisations of said layers parallel to each other.
[0116] Thus, the magnetic energy produced by stacking these two coupled layers 2 and 3 is defined by the following relation:
E =−[( k s2 −2π M 2 2 ) e 2 +k s2 ] cos 2 θ 2 −[( k v3 −2π M 2 3 ) e 3 +k s3 ] cos 2 θ 3 −A cos(θ 2 −θ 3 ).
[0117] This being so, in order for the cobalt/platinum multilayer 2 to pull the magnetisation of the cobalt or permalloy layer 3 out of plane, two conditions must be met.
[0118] Firstly, the effective out-of-plane anisotropy of layer 2 must be stronger than the effective planar anisotropy of layer 3 which is expressed by:
[( k v2 −2π M 2 2 ) e 2 +k s2 ]+[( k v3 −2π M 2 3 ) e 3 +k s3 ]>0.
[0119] Also, within the framework of the simple model presented here consisting of two layers coupled by coupling constant A and with out-of-plane anisotropy for layer 2 and planar anisotropy for layer 3 respectively, it will be possible for the magnetisation of layer 3 to be pulled out of plane by the effect of coupling with layer 2 provided that the coupling energy per unit of surface area is twice the absolute value of the effective anisotropy of layer 3 per unit of surface area.
[0120] In the case of layer 3 (cobalt or permalloy), the greater its thickness e 3 , the asymptotically higher its polarisation, especially in relation to the spin-diffusion length in diffusion mode. Nevertheless, this thickness must not assume an excessively high value capable of reducing its in-plane magnetisation once the layers have been assembled.
[0121] FIG. 2 shows, for such a structure, typically consisting of an Si/SiO 2 /Ta/(Pt/Co) n /Co x /Cu stack, the variation in remanent magnetisation, measured with a magnetic field applied perpendicular to the plane of the layers, as a function of the cobalt thickness measured from the last platinum layer.
[0122] Note that 100% remanent magnetisation in a zero field, corresponding to the characteristic whereby magnetisation of the cobalt layer is perpendicular to the plane of the layers, persists for cobalt thicknesses approaching 2.8 nm. Consequently, there is 0% remanent magnetisation indicating that magnetisation of the cobalt layer is parallel to the plane of the layers for a cobalt thickness exceeding 3 nm.
[0123] In the configuration of this first embodiment and for cobalt thicknesses less than 3 nm, one can therefore produce a perpendicular polarizer as referred to in the introduction.
[0124] In a second embodiment, shown in FIG. 3 , the structure described in the preceding example is reversed, giving a succession of substrate/copper/cobalt (ferromagnetic material)/multilayer (Co/Pt) n . This embodiment is symmetrical with the preceding embodiment, “effective” cobalt layer 3 now being located, in terms of the sequence in which the various layers are deposited, underneath cobalt/platinum multilayer 2 .
[0125] The thickness of the cobalt layers of cobalt/platinum multilayer 2 is 0.2 to 1 nm and advantageously 0.6 nm.
[0126] The thickness of the platinum layers of cobalt/platinum multilayer 2 is 0.2 to 2 nm and advantageously 1.6 nm.
[0127] The number of repetitions of the cobalt/platinum stack is 1 to 10 and advantageously 5.
[0128] FIG. 4 shows, for such a structure, more particularly the Cu/Co/(CoO 0.6 /Pt 1.6 ) 5 /Pt structure, the variation in remanent magnetisation, measured with a magnetic field applied perpendicular to the plane of the layers, as a function of the cobalt thickness.
[0129] Note that there is 100% remanent magnetisation in a zero field corresponding to magnetisation of “effective” cobalt layer 3 perpendicular to the plane of the layers for cobalt thicknesses less than 1.2 nm.
[0130] Consequently, there is less than 100% remanent magnetisation indicating that a part of magnetisation of the magnetic layers is parallel to the plane of the layers for cobalt thicknesses exceeding 1.2 nm.
[0131] In a third embodiment, one can, by combining the above two embodiments, produce a complete structure of the “spin valve” or “magnetic tunnel junction” type in particular with perpendicular magnetisation, as shown schematically in FIG. 5 in which each of the “active” magnetic layers of the junction or spin valve is produced according to one of the first two embodiments. If one wants to produce an MRAM magnetic memory, the structures of the first and of the second embodiment will be separated, for example, by a non-magnetic conductive layer or a tunnel barrier of the Al 2 O 3 or MgO type.
[0132] In a fourth embodiment shown in FIG. 6 , one uses the stack shown in the first embodiment, but this time as a “free layer” in a structure of the spin valve or tunnel junction type with planar magnetisation. The so-called “anchored” layer can have the usual structure, namely a traditional magnetic material, for example, with planar magnetisation which is exchange coupled with an antiferromagnetic material (AFM).
[0133] For a stack of the type shown in FIG. 6 , FIG. 7 shows the variation in the saturation field (the magnetic field is always applied in a direction perpendicular to the plane of the layers) as a function of the cobalt thickness (layer 3 ). This saturation field shows the intensity of the magnetic field required in order to force magnetisation of the cobalt, which is naturally parallel to the plane of the layer for thicknesses in excess of approximately 2 nm in accordance with FIG. 6 , to orient itself in a direction perpendicular to the plane.
[0134] One can see that the saturation field values are much less than those which would be required (of the order of 18 kOe) in the case of a cobalt layer of the same thickness in the absence of the perpendicular anisotropy term introduced by interaction between layer 2 and magnetic layer 3 .
[0135] In other words, this graph shows the reduction in the perpendicular saturation field when the cobalt thickness is reduced, especially when reduced down to thicknesses of the order of 2 nm. If one wants to obtain a layer with planar magnetisation but a weak demagnetising field, i.e. in the context of using the magnetic device according to the invention in relation to magnetic memories in which magnetisation switching is performed by using a spin-polarised current, one will therefore choose a cobalt thickness slightly in excess of 2 nm for the example described here.
[0136] In a fifth embodiment shown in FIG. 8 , one uses the stack shown in the second embodiment, but this time as a “free layer” in a structure of the spin valve or tunnel junction type with planar magnetisation. The so-called “anchored” layer can have the usual structure, namely a traditional magnetic material, for example, with planar magnetisation which is exchange coupled with an antiferromagnetic material (AFM).
[0137] As in the case of the fourth embodiment, this will therefore give a free layer with planar magnetisation but a weak demagnetising field, this free layer being, in this embodiment, located above the anchored layer in terms of the sequence in which the various layers of the device are deposited. | A thin-film magnetic device comprises, on a substrate, a composite assembly deposited by cathode sputtering and consists of a first layer made of a ferromagnetic material with a high rate of spin polarisation, the magnetisation of which is in plane in the absence of any electric or magnetic interaction, a second layer made of a magnetic material with high perpendicular anisotropy, the magnetisation of which is outside the plane of said layer in the absence of any electric or magnetic interaction, and coupling of which with said first layer induces a decrease in the effective demagnetising field of the entire device, a third layer that is in contact with the first layer via its interface opposite to that which is common to the second layer and made of a material that is not magnetic and not polarising for electrons passing through the device. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of remote control and more particularly, to an apparatus and method for remotely controlling a plurality of devices by means of radio frequency signals. The invention includes a number of novel security features to prevent unauthorized usage.
2. Discussion of the Prior Art
The use of radio frequency (rf) signals for the remote control of equipment is well known. For example, most automatic garage door openers employ low-power rf transmitters to open or close the garage door from within an approaching or departing vehicle. Children's remote controlled cars, trucks, boats and airplanes are also popular. However, most remote control systems have very little inherent security since the radio frequency spectrum is open to eavesdropping with both simple and elaborate receivers. Even digitally encoded control messages may be readily intercepted and these same messages may be rebroadcast by an unauthorized "intruder" at will. It is often easy for an intruder to correlate an intercepted digital message with the observation of a controlled activity and then for the intruder to replicate the desired controlled activity at will.
Most remote control devices of the prior art are configured for the control of a single device. If multiple devices must be controlled, multiple remote control channels and associated hardware (i.e., receivers, antennas, etc.) are generally required. The use of multiple rf channels makes the interception task of an intruder relatively simple since individual remote control tasks are more easily correlated with individual, identifiable rf signals. The present invention overcomes this problem by utilizing a single, primary rf channel (i.e., frequency) for the control of multiple devices. A transceiver usually located proximate the device(s) to be controlled receives remote control commands over a primary rf signal. The transceiver, in turn, decodes, authenticates, modifies, and rebroadcasts the remote control commands to individual devices using one or more low-power transmitters. The rebroadcast signal are at a different frequency than the primary rf signal. In addition, random time delays may be introduced before the rebroadcast to further disassociate the rebroadcast signal from the primary signal. Other security features are also included to make the task of interception of control signals extremely difficult.
Many attempts have been made to remotely control multiple devices. U.S. Pat. No. 3,735,412 for Remote Control Systems; issued May 22, 1973 to Roy Kampmeyer, teaches a simple, self-powered rf transmitter and receiver combination for use in a security system. The operating frequency is in the commercial fm band (88-109 MHZ) and the receiver output has only a simple relay contact. The system differs significantly from the system of the present invention. First, no attempt is made to keep the operating frequency secret. No transceiver employing a secondary frequency for rebroadcasting control information is employed. In addition, there is no attempt to encode a digital message packet, or to transmit only partial control information. Finally, unlike the inventive system, the Kampmeyer system is only capable of controlling a single device.
The problem of controlling multiple devices is addressed in U.S. Pat. No. 3,835,454 for Plural Channel Fm Remote Control System; issued Sep. 10, 1974 to Joseph Palmieri, et al. Palmieri, et al. teach a system for remotely controlling multiple servo units by using multiple, discreet transmission frequencies. In contradistinction, the system of the present invention features the use of a single transmission frequency and the encoding of a digital message including both address and control information to allow control of multiple, diverse remote devices. The Palmieri, et al. system controls only a single type of remote device, namely a servo unit. In addition, unlike the inventive system, no security features are disclosed.
U.S. Pat. No. 4,355,309 for Radio Frequency Controlled Light System; issued Oct. 19, 1982 to Robert M. Hughey, et al. teaches a system for the remote control of plural lights. The system operates at a frequency in the 320-360 MHZ range and features a digitally encoded device address. Plural receivers are set to one of several possible address codes so that each receiver responds only to transmissions intended for it. Complete control information is transmitted. The Hughey, et al. system also differs significantly from the inventive system. No transceiver is employed. No secondary, time delayed signal is utilized, and none of the other security features of the instant invention are present.
U.S. Pat. No. 4,454,509 for Apparatus for Addressably Controlling Remote Units; issued Jun. 12, 1984, to James A Buennagel, et al. uses a central message generation site and transmitter to send tone-encoded messages to a plurality of receivers. Upon command, each receiver may connect or disconnect an electrical load from the electrical power distribution network. In contradistinction, the inventive system utilizes a wireless command converter (transceiver) to rebroadcast a digitally encoded message packet on a different frequency. Also, elaborate security precautions at the central control center of the inventive system are missing from the Buennagel, et al. system.
Another attempt to provide remote control of multiple devices is disclosed in Telephone Operated Heating, Ventilating And/or Air Conditioning, the subject of U.S. Pat. No. 5,386,461, issued Jan. 31, 1995 to Richard R. Gedney. Gedney teaches a system for intercepting dual tone multiple frequency (DTMF) signal sent over a regular telephone line. Tones are decoded and utilized to activate a switch to provide on/off control of an electrical load. In an alternate embodiment, Gedney teaches the use of a low-power rf link between the tone decoding apparatus near a telephone line, and a thermostat in a remote location within the building. Specific tone sequences are used to set the thermostat to a desired temperature. The system of the present invention differs in that no telephone line is required for operation. In addition, the inventive system may be used to control a plurality of devices as opposed to the single heating, ventilating, air conditioning (HVAC) device described by Gedney. The inventive system utilizes significantly more secure encoding than is possible with simple, DTMF-based control systems. Also absent from the Gedney system is any provision for the authentication of a control signal. In contradistinction, the present invention features elaborate provisions to insure that only authorized control messages may be issued.
Another telephone-based control system, is described in U.S. Pat. No. 5,434,973 for Microcontroller for Providing Remote Control of Electrical Switches, issued Jul. 18, 1995 to Chao-Cheng Lu. Lu teaches a system for conveniently controlling multiple electrical loads within the confines of an area such as a house. Load switching is initiated at a local keyboard, although activation by means of telephone, cellular telephone, or computer network using conventional DTMF technology is also taught. Unlike the system of the present invention, no security is provided in the Lu system. Neither is the control of the system by means of a rf link (other than the cellular phone line) per se taught. In addition, Lu does not teach the use of a low power, secondary rf transmitter for the control of multiple loads within the structure.
It is, therefor, an object of the present invention to provide a radio frequency-based, remote control system for a plurality of diverse devices.
It is another object of the invention to provide control only from a central location.
It is a further object of the invention to provide a multiplicity of security features to prevent unauthorized control of any of the remotely-controlled devices.
It is still a further object of the invention to utilize wireless command converters (transceivers) which receive a partial or incomplete control message packet on a first frequency, authenticate the message packet and then form a new, complete message packet for re-transmission at a different frequency.
It is an additional object of the invention that the wireless command converter introduce a random time delay between reception of a message packet and rebroadcast of a new, complete message packet.
It is a further object of the invention to occasionally transmits spirrous, dummy control message packets.
SUMMARY OF THE INVENTION
The remote control system of the present invention features a transceiver for receiving remotely-broadcast, radio frequency (rf) signals containing encoded control commands (i.e., message packets). Each transceiver is adapted to respond only to signals intended for it. Upon receipt of an intended rf signal, the transceiver decodes and authenticates the signal. If authenticity is established and the decoded signal is recognized as a proper control signal, a new control message packet is generated using information contained in the incoming message packet and information stored in the internal micro-controller. The new message packet is broadcast by a low-power rf transmitter tuned to a different frequency than the frequency of the incoming rf signal. A random delay may be introduced between the receipt of the incoming message packet and the broadcast of the outgoing message packet to minimize the probability of correlating the output signal with the input signal. Each controlled device within range of the low-power transmitter then receives the re-broadcast signal, decodes its contents, and responds appropriately to signals intended it. A system employing a central control facility and one or more rf broadcast facilities for controlling multiple devices at independent sites is also described.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when taken in conjunction with the detailed description thereof and in which:
FIG. 1 is a schematic block diagram of the control system of the invention;
FIG. 2 is a schematic block diagram of the central wireless control facility;
FIG. 3 is a schematic block diagram of the wireless command converter (transceiver) of the invention; and
FIG. 4 is a schematic block diagram of a typical remote control receiver for use with the transceiver of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, there is shown generally at reference number 10, a schematic block diagram of the remote control system of the of the present invention. A central wireless command center 12 generates encoded control messages packets (not shown) which are then broadcast. Typically, the signal containing the encoded control messages is linked to one or more broadcast facilities by a land-line link 14. Alternatively, microwave relay link 14', a satellite uplink, 14" or similar system could be employed to transport the signal containing the control message packets from command center 12 to a broadcast facility 16.
A broadcast facility 16 receives the signal from command center 12, processes the signal, and eventually, modulates a relatively high-power transmitter with the encoded control message packets.
Typically, a sub-carrier on a commercial FM broadcast signal would be employed. The modulated rf signal is then broadcast from a transmission tower 18. In the alternative, the cellular telephone network 20, a commercial pager network 22, or a satellite uplink facility 24 could be used to broadcast an appropriate rf signal. A dedicated transmitter 26 using a frequency allocated for private commercial purposes could also be employed. This alternative potentially provides the highest level of security. In any eventuality, an rf signal 30 containing the encoded control message packets is broadcast.
A plurality of wireless command converter (WCC) transceivers 40 are deployed throughout a geographic area where rf signal 30 may be received. Each WCC 40 is surrounded by devices 42 which are to be remotely controlled. A low-power rf transmitter 90 (FIG. 3) within each WCC 40 broadcasts secondary rf signals 44. Receivers 104 (FIG. 4) in remote control units 100 (FIG. 4), attached to or contained within each device 42, are adapted to respond to rf signals 44. Remote control units 100 only respond to signals addressed to an individual device 42. In addition to devices 42 controlled by WCC 40, individual devices 46 could be adapted for the direct reception of rf signals 30 without the need for the use of WCC 40. This would defeat a major security provision of the system but, nonetheless, it could be done. For purposes of disclosure, transmitter 90 (FIG. 3) has been labeled low-power. It should be obvious to anyone skilled in the art that a high-powered secondary transmitter could be employed giving a greater geographic area within which individual devices 42 could be located without departing from the inventive concept.
Referring now to FIG. 2, there is shown generally at reference number 50 a schematic block diagram of central command facility 12 (FIG. 1). An operator 52 attends a computer console 54 comprising a keyboard 56 and monitor 58 attached to CPU 60. Console 54 could be implemented using a "dumb" terminal or in a variety of other ways well known in the art. Console 54 is attached via a communications port or local area network (LAN) to host computer 62. Computer 62 could be configured to support virtually any number of consoles 54 although only one has been shown for purposes of disclosure. Both console 54 and host computer 62 are supplied power from an uninterruptible power source (UPS) 64. A wide range of uninterruptible power options such as battery backup and/or gas or diesel-powered generation equipment might be employed to provide continuous power to the central control facility equipment. The host computer 62 communicates any valid command signals to the broadcast facilities 14 for distribution to the (WCC)) units 40. A receiver 70 tuned to the broadcast signal carrier monitors the transmitted signal 30. Receiver 70 is connected to host computer 62 and provides feedback to computer 62 regarding the actual signal broadcast 30.
Operator 52 receives instructions via telephone, facsimile, computer network, or other such communication facility (not shown) regarding control instructions to be issued. Operating procedures require that operator 52 be logged into computer 62 before any control commands may be generated. An operator 52 must be relieved by another operator 52 logging in to the system before the transfer of responsibility of the command center from the retiring operator 52 is given to the new operator 52 for only one operator can be logged into the system at a time. In addition, the identity of anyone requesting operator 52 to issue a command is also carefully ascertained. Systems of identification including passwords, etc. may be employed to minimize the acceptance of remote control requests from anyone except authorized callers.
Referring now to FIG. 3 there is shown a schematic block diagram of the wireless command converter (WCC) 40 of the invention. A receiver 82 is turned to the known broadcast frequency of transmitter 16 (FIG. 1). An antenna 84, tuned to the selected broadcast frequency 30, is confined to the interior of WCC 40. This provided physical protection for antenna 84 and also provides a measure of security in that a probable operating frequency range can not be casually surmised from the physical characteristics of antenna 84 by someone attempting to compromise the control system. In some implementations, receiver 82 may have its reception frequency controlled by an optional external crystal 86. The output of receiver 82 is connected to a micro-controller 88 which serves to decode and authenticate commands received from receiver 82. Micro-controller 88 is connected to a low-power transmitter 90. The operating frequency of transmitter 90 does not need to be related in any way the frequency of primary signals broadcast by transmitter 66 (FIG. 2). A transmitting antenna 92 is also fully contained within the housing of WCC 40 for the same reasons as described for receiving antenna 84. All components of WCC 40 are powered from a power supply 94. Power supply 94 is normally connected to a 115 volt ac power source. In addition to powering the circuitry of WCC 40, power supply 94 keeps battery backup 96 at a full charge. In the event of an ac power failure, battery 96 powers WCC 40. The size of battery 96 is chosen for a particular set of operating circumstances such as the probability of a power failure and the criticality of the mission of WCC 40.
Referring now to FIG. 4, there is shown a schematic block diagram of a wireless remote control unit (RCU) 100. RCU 100 contains a receiving antenna 102. Antenna 102 is fully contained within the housing of RCU 100 for the same reasons previously enumerated hereinabove. Antenna 102 is tuned to the secondary frequency of broadcast of WCC 40 (FIG. 3). A receiver 104 is connected to antenna 102. Receiver 104 is also turned to the secondary frequency broadcast by WCC 40 (FIG. 3). Micro-controller 106 is connected to the output of receiver 104 and functions to decode and authenticate commands broadcast by WCC 40 (FIG. 3). A switching means 108, typically a relay or latching relay is connected to the output of micro-controller 106. The contact configuration of switching means 108 may be chosen to properly interface to the device (not shown) being controlled. Contacts may appear at a terminal strip 110 or at a connector (not shown) as best serves a particular external device (not shown). RCU 100 is also typically powered from a 115 volt AC line by means of power supply 112. A battery backup 114 may be optionally included if operating circumstances warrant. Power supply 112 also serves as a battery charger for battery 114. While a simple relay has been chosen for purposes of disclosure, it will be obvious to anyone having skill in the art that a wide variety of output devices, well known to those skilled in the art, for providing analog and/or digital outputs could easily be configured.
The operation of the inventive system will now be described. Referring again to FIG. 2, an operator 52 enters the remote command center 12 (FIG. 1). Operator 52 enters a unique identification code into computer console 54. The operator's id is compared to a database of valid operator ids in host computer 62. If the entered operator id is valid (i.e., it is recognized by host computer 62), the operator 52 is allowed to log into the system.
A request for a control action originates outside remote command center 12 and is transmitted to operator 52 by phone, fax, computer network, or other communications means. The request must be validated using any of a variety of techniques well know in the art and forming no part of the present invention. Once operator 52 has validated the request for a control action, a command is entered into console 54 via keyboard 56, a mouse (not shown), a voice recognition unit (not shown), or any other known data entry device or technique. Included in the data entered must be the identification of the device to be controlled and the control action desired. A database (not shown) within host computer 62 is queried. Assuming that a valid device has been identified and a meaningful, legal control action has been requested, host computer 62 assembles a message packet. The message packet is encoded and contains data that is incomplete with regard to ultimately controlling the selected device. That is, even if the message packet were to be intercepted and applied to the selected device, no control action could occur. This is an important security feature of the inventive system.
Referring again also to FIG. 1, The message packet is sent to a broadcast facility 16. Transmission of the message packet may be by dedicated land-line 14, dial-up common carrier line (not shown), microwave link 14', a cellular telephone link (not shown), satellite uplink/downlink 14" or by any other means known to those skilled in the art for the transmission of data from one location to another. It should be noted that a secure communications link is desirable, although not absolutely necessary to overall maintain security of the system. At broadcast facility 16, the message packet modulates an rf carrier 30 at a frequency compatible with the WCC 20 (FIG. 3) associated with the selected device. The rf signal 30 is then broadcast from a transmitting tower 18. In alternate embodiments, any of a number of different transmission strategies may be employed to implement the inventive system. A commercial pager network 22 or a cellular telephone network 20 could be employed to carry the message packet. The message packet could be carried as a sub-carrier on a commercial FM broadcast signal as is also well known in the art. A direct satellite uplink/downlink 26 might also be employed.
Rf signal 30 eventually arrives WCC 40. Referring now also to FIG. 3, rf signal 30 is received at receiving antenna 84 which is completely enclosed within the case of WCC 40. Receiver 82 is tuned to the frequency of rf signal 30. In some embodiments, an optional crystal 86 may be employed to stabilize the receiving frequency of receiver 82. Receiver 82 demodulates rf signal 30 and recovers the message packet. The message packet is passed to micro-controller 88 where it is checked against an embedded address. If the message packet is destined for the particular WCC 40, it is further processed, otherwise, the message packet is ignored. Assuming that the message packet is intended for the particular WCC 40, the message content is further decoded according to a pre-programmed algorithm in micro-controller 88. If the decoded message packet passes any necessary validity tests, a new, output message packet is assembled by micro-controller 88 using a combination of the received message packet and additional information stored within memory (not shown) associated with micro-controller 88. It is important to note that neither the original message packet nor the data within micro-controller 88 is sufficient in and of itself to control the selected device. Only when the original message packet is combined with additional information from within micro-controller 88 is a message packet capable of controlling the selected device formed. This technique forms another important part of the security strategy of the present invention.
An additional security feature, which is implemented in micro-controller 88, is the insertion of a pseudo-random delay between receiving the incoming message packet and transmitting the outgoing message packet. This delay further thwarts any attempt to correlate an incoming rf signal with the outgoing rf signal from the WCC 40 and forms another important component of the security of the inventive system. The output message packet is eventually passed to transmitter 90 where it modulates a new rf signal. The output rf signal is usually at a significantly different frequency than the input signal. Typical operating frequencies could be approximately 900 MHZ for the input frequency and approximately 300 MHZ for the output frequency. Any two frequencies could be chosen to be compatible with particular operating environments and circumstances and the choice of particular frequencies does not form part of the present invention. It is possible that under some circumstances that an identical input and output frequency could be chosen but this would circumvent an important security feature. The rf output signal is applied to transmitting antenna 92. Both antennas 84 and 92 are generally optimized to operate at their respective chosen operating frequencies. Both antennas 84 and 92 are also physically contained within the enclosure of WCC 40 for two important reasons. First, because the physical length of the antennas could provide a clue to the operating frequencies, it is hidden from view. The case also provided physical protection for the antennas. The rf output signal is now broadcast to the remote control units associated with a plurality of devices under the control of the particular WCC 40.
Referring now also to FIG. 4, the output rf signals from WCC 40 arrive at the receiving antenna 102 of remote control unit 100. The signal from antenna 102 is applied to receiver 104 where the received message packet is demodulated. The demodulated message packet is applied to micro-controller 106 where is checked to determine whether or not the transmission is intended for the particular device under the control of the remote control unit 100. If the address component of the incoming message packet matches the address of the remote control unit, micro-controller 106 performs further decoding and verification of the message packet. Finally, a control signal is provided to relay 108 where contacts are opened or closed to provide a controlling signal for an external device. It should be obvious to those skilled in the art that any number of control strategies more sophisticated than the simple contact closure chosen for disclosure could be employed to provide either analog and/or digital control outputs from remote control unit 100. For example, a digital-to-analog converter (DAC) could be utilized to provide a controlled analog signal, if required.
In some operating environments, optical (opto) isolators may prove beneficial and may also be included in wireless remote control unit 100 to protect internal circuitry from externally-generated voltage spikes or other interference.
Since other combinations, modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the chosen preferred embodiments for purposes of disclosure, but covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims. | A transceiver is used to receive remotely-broadcast, radio frequency (rf) signals at a first frequency. The remotely-broadcast rf signals contain encoded, partial control commands as message packets. Each transceiver is adapted to respond only to signals addressed to it. Upon receipt of an intended rf signal, the transceiver decodes and authenticates the signal. If authenticity is established and the decoded signal is recognized as a proper control signal, a new control message packet is generated using information contained in the incoming message packet and information stored in the memory of the internal micro-controller. The new message packet is broadcast using by a low-power rf transmitter tuned to a different frequency that the frequency of the incoming rf signal. A random delay may be introduced between the receipt of the incoming message and the broadcast of the outgoing message to minimize the probability of correlating the output signal with the input signal. Each controlled device within range of the low-power transmitter then receives the new signal, decodes its contents, and responds appropriately to signals intended for the individual device. | 8 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Patent Application Ser. No. 60/526,457 filed on Dec. 3, 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to the field of electrical field logging of oil wells. More specifically, the present invention is a method of obtaining a measure of a parameter of a formation using a real component of an electrically induced signal in a formation.
[0004] 2. Description of the Related Art
[0005] It is important to the oil and gas industry to know the nature and characteristics of the various sub-surface formations penetrated by a borehole because the mere creation of a borehole (typically by drilling) usually does not provide sufficient information concerning the existence, depth location, quantity, etc., of oil and gas trapped in the formations. Various electrical techniques have been employed in the past to determine this information about the formations. One such technique commonly used is induction logging. Induction logging measures the resistivity (or its inverse, conductivity) of the formation by first inducing eddy currents to flow in the formations in response to a transmitter signal, and then measuring a phase component signal in a receiver signal generated by the presence of the eddy currents. Variations in the magnitude of the eddy currents in response to variations in formation conductivity are reflected as variations in the receiver signal. Thus, in general, the magnitude of the in- phase component (the component that is in-phase with the transmitter signal) is indicative of the conductivity of the formation.
[0006] The physical principles of electromagnetic induction resistivity well logging are described, for example, in H. G. Doll, Introduction to Induction Logging and Application to Logging of Wells Drilled with Oil - Based Mud, Journal of Petroleum Technology, vol. 1, p.148, Society of Petroleum Engineers, Richardson, Tex. (1949). Many improvements and modifications to electromagnetic induction resistivity instruments have been devised since publication of the Doll reference, supra. Examples of such modifications and improvements can be found, for example, in U.S. Pat. No. 4,837,517; U.S. Pat. No. 5,157,605 issued to Chandler et al.; and U.S. Pat. No. 5,452,761 issued to Beard et al.
[0007] The basic theory of induction logging instruments for evaluation of formation resistivity is taught in U.S. Pat. No. 3,147,429 to Moran and is summarized here. Shown in FIG. 1 are exemplary transmitter coil and receiver coil with a distance L between them. The transmitter has a product A t of the cross-sectional area times the number of coils. The corresponding product for the receiver coil is A r . The propagation constant k is given by:
k={square root}{square root over (jωσμ)} (1)
where j is the square root of −1, ω is the angular frequency of the signal, σ is the formation conductivity and μ is the permeability of the medium. Eqn. (1) can be rewritten as
γ = 1 + j δ ( 2 )
where δ denotes the “skin depth” in the medium and is given by
δ = 2 ω σ μ ( 3 )
[0008] When a current I is passed through the transmitter, eddy currents are induced in the formation which in turn induce a magnetic field and eddy currents in the receiver. The total receiver voltage V is given by the expression:
V = - j ω I μ A T A R 2 π L 3 [ 1 - ( j γ L ) 2 2 - ( j γ L ) 3 3 - - ( j γ L ) 4 8 - ( j γ L ) 5 30 - … ] . ( 4 )
[0009] Separating into real and imaginary parts gives the real and imaginary parts V r and V x (in-phase and quadrature components) as
V r = σω 2 μ 2 A t A r 4 π L [ 1 - 2 3 ( L δ ) + 2 15 ( L δ ) 2 - … ] ( 5 ) and V x = σωμ I A t A r 4 π L [ - 1 + 2 3 ( L δ ) 3 - 1 2 ( L δ ) 4 + 2 15 ( L δ ) 5 ] ( 6 )
It should be pointed out that the quadrature component of voltage is equivalent to the real component of the magnetic field.
[0010] A typical electrical resistivity-measuring instrument is an electromagnetic induction military well logging instrument such as described in U.S. Pat. No. 5,452,761 issued to Beard et al. The induction logging instrument described in the Beard '761 patent includes a number of receiver coils spaced at various axial distances from a transmitter coil. Alternating current is passed through the transmitter coil, which induces alternating electromagnetic fields in the earth formations. Voltages, or measurements, are induced in the receiver coils as a result of electromagnetic induction phenomena related to the alternating electromagnetic fields. A continuous record of the voltages forms curves, which are also referred to as induction logs. Induction instruments that are comprised of multiple sets of receiver coils are referred to as multi-array induction instruments. Every set of receiver coils together with the transmitter is called a subarray. A multi-array induction tool consists of numerous subarrays and acquires measurements with all the subarrays.
[0011] Voltages induced in the axially more distal receiver coils are the result of electromagnetic induction phenomena occurring in a larger volume surrounding the instrument, and the voltages induced in the axially proximal receiver coils are the result of induction phenomena occurring more proximal to the instrument. Therefore, different receiver coils see a formation layer boundary with different shoulder-bed contributions, or shoulder-bed effects. The longer-spaced receiver coils see the formation layer boundary at further distance from the borehole than the shorter-spaced receiver coils do. As a result, the logs of longer-spaced receiver coils have longer shoulder-bed effects than the logs of shorter-spaced receiver coils. The logs of all the receiver coils form a certain pattern.
[0012] A newly developed induction instrument comprises three mutually orthogonal transmitter-receiver arrays. Such a configuration makes it possible to determine both horizontal and vertical resistivities for an anisotropic formation in vertical, deviated, and horizontal boreholes. A description of the tool can be found in U.S. Pat. No. 6,147,496 to Strack, et al. The transmitters induce currents in three mutually perpendicular spatial directions and the receivers measure the corresponding magnetic fields (H xx , H yy , and H zz ). In this nomenclature of the field responses, the first index indicates the direction of the transmitter, the second index denotes the receiver direction. As an example, H zz is the magnetic field induced by a z-direction transmitter coil and measured by a z-directed receiver. The z-direction is parallel to the borehole. Included in Strack is a teaching of how measurements made at two frequencies can be combined to give the resistivity of the earth formation away from the borehole while avoiding the effects of possible invasion of borehole fluids into the formation. Other methods for processing of multicomponent induction data use a frequency focusing method in which measurements are made at several frequencies. Examples of such methods are given in U.S. Pat. No. 6,574,562 of Tabarovsky et al.
[0013] The imaginary component of the magnetic field is commonly used in the inversion processing methods identified above. This corresponds to the real part of the voltage noted above in eqn. (5). The real component of a single frequency magnetic field measurement has similar properties to the imaginary component of a dual frequency (or multi-frequency) magnetic field measurement. So far, industry has not used the real component of magnetic field from induction logging data in data processing. The present invention is directed towards the use of the real component of the magnetic field for determination of anisotropic formation resistivity.
SUMMARY OF THE INVENTION
[0014] The present invention is a method and apparatus for logging of an earth formation including a plurality of layers having a horizontal resistivity and a vertical resistivity, at least one of the layers having a horizontal resistivity different from the vertical resistivity
[0015] A logging tool is conveyed into a borehole in the earth formation. The logging tool has first and second transmitter axes inclined to each other. The first and second transmitters send electromagnetic signals at at least one frequency into the earth formation. Signals resulting from interaction of the transmitted signals with the earth formation are received by suitable receivers, the received signals having a phase substantially the same as the phase of said transmitted signals. A processor is used to process the received signals to determine the horizontal and vertical resistivity of the at least one layer.
[0016] One of the two transmitters may have an axis substantially parallel to an axis of the logging tool and the other transmitter may have an axis substantially orthogonal to the first axis. Alternatively, the axes of the two transmitters may be inclined at angles other than 0° and 90° to the tool axis: in the latter case, the processor performs a rotation of coordinates of the received signals.
[0017] The processing includes defining a layered earth model of the earth formation. The received signals are inverted using the defined model. The inversion may include first determining the horizontal resistivity using a subset of the received signals. The vertical resistivity is then determined using another subset of the received signals and the derived horizontal resistivity. The invention may be practiced with measurements at either a single frequency or with measurements at a plurality of frequencies.
[0018] The processor may be located at a surface location or at a downhole location. The transmitters and receivers may be conveyed on a wireline or on a bottom hole assembly for measurement-while-drilling applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention is best understood with reference to the accompanying figures in which like numerals refer to like elements and in which:
[0020] FIG. 1 (prior art) shows the geometry of coils for a prior art induction logging tool;
[0021] FIG. 2 (prior art) is an illustration showing an induction logging tool deployed in a borehole for measuring the conductivity of the adjacent formation;
[0022] FIG. 3 shows a resistivity formation model and several logging responses to the model;
[0023] FIG. 4 shows true and obtained resistivity values for the model of FIG. 3 ;
[0024] FIG. 5 shows obtained logging responses from a low-resistivity field formation;
[0025] FIG. 6 shows obtained resistivity values for the low-resistivity field formation of FIG. 5 ;
[0026] FIG. 7 shows obtained logging responses from a high-resistivity field formation;
[0027] FIG. 8 shows obtained resistivity values for the high-resistivity field formation of FIG. 7 ; and
[0028] FIG. 9 (prior art) shows an arrangement of transmitter and receiver coils for making multicomponent measurements.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Referring now to FIG. 2 , an induction logging tool 20 suitable for use with the present invention is shown positioned in a borehole 22 penetrating earth formations 54 . The tool 20 , which is suspended in the borehole 22 by means of a wireline cable 24 , includes a borehole sonde 34 and an electronic circuitry section 32 . The tool 20 is lowered into the borehole 22 by a cable 24 , which passes over a sheave 31 located at the surface of the borehole 22 . The cable 24 is typically spooled onto a drum 30 . The cable 24 includes insulated electric conductors for transmitting electrical signals. The electronic circuitry section 32 of the tool 20 receives signals from the sonde section 34 to perform various analog and digital functions, as will be described later.
[0030] The sonde 34 preferably includes a plurality of coils 40 - 52 . Coil 46 is a transmitter coil for transmitting an oscillating signal into the adjacent surrounding geological formation 54 . Preferably, a square wave signal is supplied to the coil 46 . However, it is contemplated that any of a number of oscillating voltage signals having multiple frequency components can be used. Further, it is desirable that, on occasion, a single-frequency signal, such as a sinusoidal signal, is used. The oscillating voltage signal applied to the coil 46 generates a current in coil 46 which in turn generates an electromagnetic field in the surrounding formation 54 . The electromagnetic field, in turn, induces eddy currents, which flow coaxially with respect to the borehole 22 . The magnitudes of the eddy currents are related to the conductivity of the surrounding formation 54 . The remaining coils 40 , 42 , 44 , 47 , 48 , 50 and 52 are receiver coils in which signals are induced by the electric fields caused by the eddy currents produced in the formation. As the tool 20 is raised in the borehole 22 , the conductivity of the surrounding formation 54 can be determined from the received signals in order that a bed or layer 55 having a conductivity that is indicative of the possibility of containing hydrocarbons may be located.
[0031] The electronic circuitry section 32 includes a converter circuit 60 , a stacker circuit 62 , a random access memory (RAM) 63 , and a telemetry circuit 61 . The converter circuit 60 comprises a plurality of pre-amplifiers, filters, and analog-to-digital (A/D) converters for receiving signals from the receiver coils 40 - 52 and transforming them into digitized signals for further processing by the stacker circuit 62 . The analog voltage signals provided by the receiver coils 40 - 52 are digitally sampled according to a predetermined sampling rate in the period defined by the fundamental frequency of the transmitter signal, which in a typical embodiment is approximately 10 kHz.
[0032] The sampling is repeated over a large number of transmitter voltage signal cycles, preferably at least 1,024 cycles to improve the signal-to-noise ratio of the received signals. To reduce the amount of data that must be stored or transmitted, corresponding digital samples taken in each of the transmitter cycles are summed. The summed digital signal samples corresponding to each of the plurality of receiver coils form corresponding stacked signal samples, which are stored in the RAM 63 . The stacked signals corresponding to the plurality of receiver coils 40 - 52 can then be retrieved from the RAM 63 and can be transmitted by the telemetry circuit 61 through the cable 24 to a processor 64 which forms part of the surface equipment 26 , where analyses of the stacked signals can be performed. Alternatively, processing of at least part of the data could be performed downhole using a processor at a suitable location (not shown) and results of the processing telemetered uphole.
[0033] In an alternative embodiment, a processor having sufficient digital signal processing capabilities could form part of the electronic circuitry section 32 . Thus, it is contemplated that the required discrete Fourier transform could be performed downhole, which would further reduce the amount of data to be transmitted to the surface.
[0034] The measured zz signal in a borehole drilled perpendicular to a formation is responsive only to the horizontal resistivity of the earth formation. This is due to the fact that the currents induced by a z-component transmitter are in a plane parallel to bedding and are not affected by the vertical resistivity of an anisotropic formation. An x- or a y-component transmitter in a borehole drilled perpendicular to a formation, on the other hand, induces currents that flow in both vertical and horizontal directions (and also at intermediate angles). Hence the xx and yy signals are responsive to both vertical and horizontal resistivities. Commonly used inversion procedures rely on the zz signal for determination of horizontal resistivity, and this determined horizontal resistivity is used for obtaining the vertical resistivity from the xx and/or yy signals. Consequently, inverted values of vertical resistivities are less accurate than inverted values of horizontal resistivities.
[0035] Before discussing the remaining figures, we note the convention used for the tracks in FIGS. 3 - 8 :
The term ‘single’ represents the imaginary component of the magnetic field obtained for a single frequency measurement; the term ‘dual’ represents the imaginary component of the magnetic field obtained for a dual frequency measurement; and the term ‘real’ represents the real component of the magnetic field obtained for a single frequency measurement.
[0039] Referring now to FIG. 3 , the model is shown in the first track and depicts an anisotropic formation having horizontal and vertical resistivities. 201 and 203 show the horizontal and vertical resistivities used in a model. A vertical well was used for the model, so that the XX and YY responses are identical 204 and 205 in track 2 show the XX responses for frequencies of 20.8 kHz and 41.7 kHz respectively. Track 3 shows two dual frequency responses to the resistivity model of track 1 . 207 is the dual frequency response for frequencies of 20.8 kHz and 41.7 kHz respectively, while 208 shows the dual frequency response for frequencies of 41.7 kHz and 83.3 kHz respectively. Finally, track 4 shows the real responses 209 and 210 for frequencies of 20.8 kHz and 41.7 kHz respectively. The scale at the top of tracks 3 and 4 are for a range of values of ±0.004 Wb/m 2 . It can be seen that the real component ( 209 and 210 ) generally has larger signal values than the dual frequency measurements ( 207 and 208 ).
[0040] FIG. 4 shows inversion results for the noise-free synthetic data in a vertical well of FIG. 3 . One method for inversion of multicomponent data suitable for use in the present invention is described in U.S. Pat. No. 6,591,194 to Yu et al. having the same assignee as the present invention and the contents of which are fully incorporated by reference. Yu's method is also applicable to deviated boreholes.
[0041] As described in Yu, measurements made by a multicomponent logging tool in a borehole are inverted to obtain horizontal and vertical resistivities of a formation traversed by the borehole. The model includes layers of equal thickness, each layer having a horizontal resistivity and a vertical resistivity. For a vertical borehole, the inversion is done by first iteratively obtaining the horizontal resistivities of the layer using the H zz component of the data wherein in successive steps of the iteration, the horizontal resistivity for each layer is multiplied by a ratio of a model H zz output to the measured H zz . The vertical resistivity model is set equal to the derived horizontal resistivities and the iterative process is repeated using the ratio of the model H xx output to the measured H xx . A similar process is used for boreholes with a known inclination. For such an inclined borehole, the two horizontal components H xx and H yy are summed to give a horizontal measurement H xxyy that is independent of tool rotation. The first step uses a ratio of the model H zz output to the measured H zz data to obtain an apparent resistivity, and, in the second step, the ratio of the model H xxyy output and the measured H xxyy data are used along with a known relationship between the apparent resistivity and the horizontal and vertical resistivities in an iterative manner. No Jacobians or gradients are necessary in the method, so that computational times are small relative to prior art gradient methods. It should be noted that similar results can be obtained by using other inclinations of the transmitter and receiver axes to the borehole axes as long as they can be rotated into principal components (x-, y- and z- directions) by a rotation of coordinates. While Yu discusses the inversion of dual frequency data, there is no teaching therein of inversion of the real component of data. It should also be noted that methods other than those disclosed by Yu could also be used for inversion of multicomponent data. An example of such a method is described in U.S. Pat. No. 6,643,589 to Zhang et al.
[0042] Track 1 301 shows three curves that are very similar. One is the true anisotropy of the model, a second curve shows the result of inverting the dual frequency model output of FIG. 3 , while the third curve shows the results of inverting the real component model output of FIG. 3 . Track 2 303 of FIG. 4 shows a comparison of the true horizontal resistivity and the results of inverting the single frequency model output. The fact that there is little difference between the curves in track 2 demonstrates the accuracy of the inversion technique. Finally, track 3 shows a comparison of the true vertical resistivity with the results of inverting the dual frequency model output and inverting the real component of the model output. The differences of the three curves of track 3 are somewhat larger than in track 2 , but are still within acceptable limits. The somewhat larger differences are an indication the vertical resistivity inversion is not quite as accurate as inversion for horizontal resistivity. Reasons for the somewhat lower accuracy have been noted above.
[0043] Turning now to FIG. 5 , a field data for a formation having high conductivity is shown. 401 , 402 and 403 are dual frequency xx measurements for frequencies of (20.8 kHz, 41.7 kHz), (41.7 kHz, 83. kHz) and (83.3 kHz and 166 kHz) respectively. 405 , 406 , and 407 are the real component xx measurements at 20.8 kHz, 41.7 kHz and 83.3 kHz respectively. The scale for the dual frequency measurements is ±0.002 Wb/m 2 , while the scale for the real component measurements is ±0.004 Wb/m 2 . FIG. 5 shows that the real component has higher signal levels than the dual frequency measurements in conductive formations. This is to be expected since the dual frequency measurement is a scaled difference between two single frequency measurements. Results of inverting the data of FIG. 5 are shown in FIG. 6 .
[0044] Track 1 501 of FIG. 6 shows two interpreted anisotropy curves that are very similar to each other. One curve is from inversion of dual frequency data from FIG. 5 while the other curve is from inversion of real component data from FIG. 5 . Track 2 503 of FIG. 6 shows horizontal resistivity obtained by inversion of single component data while track 3 505 shows a comparison of inverted vertical resistivity from dual and real component data. The agreement between the inverted resistivities is good, demonstrating that in conductive formations, inversion of the real component of induction measurements gives results as good as those obtained by inversion of the imaginary component of dual frequency measurements.
[0045] FIG. 7 shows a field example from a resistive formation that has a horizontal resistivity greater than 5 Ω-m. Track 1 shows dual frequency measurements 601 at 20.3 kHz and 41.7 kHz. Track 2 shows dual frequency measurements 602 at 41.7 kHz and 83.3 kHz, while track 3 shows dual frequency measurements 603 at 83.3 kHz and 166 kHz. Tracks 4 , 5 and 6 (curves 604 , 605 and 606 ) show real component measurements at 20.8 kHz, 41.7 kHz and 83.3 kHz respectively. The dual frequency measurements show more high frequency jitter than the real components. Compare, for example, 602 and 605 . While full-scale values for the corresponding dual and real components are the same, i.e., tracks 1 and 4 , tracks 2 and 5 , and tracks 3 and 6 , it is noted that the real component has somewhat higher signal level. This higher amplitude is most clearly seen at the depth indicated by 611 .
[0046] Turning now to FIG. 8 , results of inverting the data of FIG. 7 are shown. Track 1 701 shows a comparison of the inverted anisotropy from dual frequency and real component measurements. Track 2 703 shows a comparison of the inverted horizontal resistivities. Little difference is noted in track 2 between the two curves. Finally, track 3 705 shows large differences between the real and dual frequency inversions.
[0047] One possible explanation for the large excursions is the presence of an offset in the measurements. The real component measurements are inherently more susceptible to errors caused by direct coupling between the transmitter and the receiver. This is commonly addressed by the use of bucking coils in the hardware. The effects of direct coupling between the transmitter and receiver are much smaller for the imaginary component of the measured signal. Consequently, offset is more likely to be present with the real component measurement. The effect of direct coupling needs to be removed.
[0048] Thus, using the method and apparatus described above, it is possible to determine parameters of interest of an earth formation such as horizontal and vertical resistivities of one or more layers of the earth formation.
[0049] A suitable arrangement of transmitter and receiver coils for making multicomponent measurements is shown in U.S. Pat. No. 6 , 618 , 676 to Kriegshauser et al and shown in FIG. 9 . Shown therein is the configuration of transmitter and receiver coils of the 3D Explorer™ induction logging instrument of Baker Hughes. Three orthogonal transmitters 801 , 803 and 805 that are referred to as the T x , T z , and T y transmitters are shown (the z- axis is the longitudinal axis of the tool). Corresponding to the transmitters 801 , 803 and 805 are associated receivers 807 , 809 and 811 , referred to as the R x , R z , and R y receivers, for measuring the corresponding magnetic fields. In a preferred mode of operation of the tool, the H xx , H yy , H zz , H xy , and H xz components are measured, though other components may also be used.
[0050] In FIG. 9 , the transmitter and receiver coils are shown in a fixed orientation relative to the body of the logging tool. In an alternate embodiment of the invention, the transmitters and/or receivers may be gimbal mounted using methods known in the art.
[0051] The method of the present invention has been discussed above with reference to a logging device conveyed on a wireline. However, the method of the invention is equally applicable to logging devices conveyed on a bottomhole assembly for measurement-while-drilling (MWD) applications.
[0052] It should further be noted that the method of the present invention has been given using examples of a single frequency, measurement of the real component of the magnetic field. The method of the present invention could also be used with dual or multiple frequency, real component measurements.
[0053] While the foregoing disclosure is directed to the preferred embodiments of the invention, various modifications will be apparent to those skilled in the art. It is intended that all such variations within the scope and spirit of the appended claims be embraced by the foregoing disclosure. | Multi-component induction measurements are made using a resistivity logging tool in an anistropic earth formation. A subset of the multi-component measurements are inverted to first determine horizontal resistivities. Using the determined horizontal resistivities and another subset of the multi-component measurements, the vertical resistivities are obtained. Results of using the in-phase signals are comparable to those obtained using multifrequency focusing of quadrature signals. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a hair styling system. More particularly, the present invention relates to a hair treatment system and method utilizing a hot hair iron.
[0003] 2. Description of the Related Art
[0004] Flat iron hair straighteners and/or crimpers are well known. Typically, these devices have two pivoting arms with at least one arm having a heating surface suitable for making direct contact with the hair of a user. These devices can be configured to provide a variety of different styling effects to the hair. For example, as locks of hair are gripped between the two arms, the hair can be straightened, curled or crimped depending on the configuration of the heating surface.
[0005] Furthermore, it is also well known to apply various substances to the hair in the treatment and/or styling of hair. These substances are often in liquid semi-liquid (e.g., gel) form and are typically applied to the hair via a person's hand and/or a delivery vessel with a dispensing outlet. Examples of substances commonly applied to the hair include moisturizing agents, anti-static agents, de-tangling agents, straighteners, conditioners, and shine enhancers. Certain of these various substances are intended to be applied in a dry form or when the hair itself is dry. For example, it is desirable to apply certain substances only to the distal ends or portions of the hair rather than to the scalp. Another example is when it is desirable to apply a substance during a final styling step such as brushing or blow-drying. Consequently, techniques have been developed to facilitate these different applications. For example, certain substances are applied to the hair via a medium such as a cloth or fabric. Typically, a piece of cloth or fabric is impregnated or soaked in the hair treatment substance to be applied to the hair and is then applied to the hair as appropriate to achieve a desired effect (e.g., applied directly to the distal ends of the hair or to selected groups of hair).
[0006] In using a piece of cloth or fabric to apply a substance to the hair, it is often necessary to drape or wrap the saturated cloth over and/or about the hair or head to facilitate the effective transfer of the substance to the hair. Further, it is also often necessary to apply heat, via a blow dryer, for example, to facilitate the effective transfer of certain heat sensitive substances.
[0007] Accordingly, there is a need for an effective, efficient and versatile system that facilitates the effective transfer of any of a variety of different hair treatment substances in accordance with various specialized or required hair styling or conditioning procedures.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a system, and related method, for efficiently and effectively applying any of a variety of substances to selected portions of a person's hair via a cloth.
[0009] It is another object of the present invention to provide a system, and related method, for applying any of a variety of heat sensitive substances to selected portions of a person's hair via a cloth in combination with a heatable hair styling tool.
[0010] It is a further object of the present invention to provide a system, and related method, for applying any of a variety of substances to selected portions of a person's hair via a cloth in combination with a straightening and/or curling iron.
[0011] These and other objects and advantages of the present invention are achieved by a hair treatment system with a hair styling tool having a pair of pivotally connected arms, one or more hair contacting elements that can be permanently or removably connected to the hair styling tool, a securing frame that can be permanently or removably connected to the one or more hair contacting elements and/or the hair styling tool, and an application cloth for applying a substance to desired, selected portions of a person's hair.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is an exploded perspective view of a hair styling or conditioning system in accordance with an illustrative embodiment of the present invention;
[0013] [0013]FIG. 2 is a top view of a contacting plate in accordance with an illustrative embodiment of the present invention;
[0014] [0014]FIG. 3 is a side view of the contacting plate of FIG. 2;
[0015] [0015]FIG. 4 is a bottom plan view of the contacting plate of FIG. 2;
[0016] [0016]FIG. 5 is a plan view of a first frame element in accordance with an illustrative embodiment of the present invention;
[0017] [0017]FIG. 6 is a plan view of a second frame element in accordance with an illustrative embodiment of the present invention; and
[0018] [0018]FIG. 7 is a plan view of the first frame element of FIG. 5 and second frame element of FIG. 6 cooperating to hold an application cloth in accordance with an illustrative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring to the drawings and, in particular, FIG. 1, there is shown a hair treatment system in accordance with an illustrative embodiment of the present invention generally represented by reference numeral 1 . Preferably, treatment system 1 has a hair styling tool 2 , one or more heatable hair contacting elements 4 connected to hair styling tool 2 , one or more securing frames 6 connected to hair styling tool 2 and/or hair contacting elements 4 , and one or more application fabric or cloth 8 cooperative with hair contacting elements 4 via frames 6 .
[0020] While the preferred aspects described herein relate, by way of example, to a styling tool as shown in FIG. 1, system 1 of the present invention may additionally and/or alternatively use any of a variety of other styling tools, such as, for example, curling irons, hair setters, setting rollers, and other like devices. Also, although a heat-activated substance is, by way of example, used to illustrate certain preferred aspects of the present invention, a variety of additional and/or alternative substances including, but not limited to, moisturizing agents, anti-static agents, de-tangling agents, straighteners, conditioners, shine enhancers and/or other heat-activated substances.
[0021] Hair styling tool 2 preferably has a pair of pivotally connected arms 10 . Each arm 10 preferably has a hand gripping portion 12 and a hair engaging portion 14 . Each arm 10 has a proximal end 16 and a distal end 20 . Arms 10 are preferably pivotally connected at proximal end 16 thereof via a hinge 18 . Hinge 18 preferably biases arms 10 apart. The bias associated with hinge 18 can be selectively overcome via a user interaction. For example, hand gripping portions 12 are preferably shaped, sized and/or configured to enable a user to efficiently overcome the bias of hinge 18 .
[0022] Hair engaging portions 14 are preferably located at distal ends 20 of arms 10 and arms 10 . Arms 10 can be manipulated, for example, via gripping portions 12 so that the arms pivot relative to each other about hinge 18 to selectively move hair engaging portions 14 between a closed, relatively parallel state, and an open, relatively angled state. Hair engaging portions 14 are preferably suitable for selectively mounting, holding and/or retaining hair contacting elements 4 and/or frames 6 .
[0023] In one aspect of the present invention, hair engaging portions 14 of each arm 10 form paddles that face each other so as to be selectively closed or clamped together and open or separated apart. In this aspect of the invention, hair engaging portions 14 are suitable to be clamped about selected portions of hair to apply heat and/or provide a styling effect thereto. Depending on the shape, size and/or configuration of hair engaging portions 14 and the technique employed, hair can be straightened, shaped and/or otherwise styled as desired.
[0024] Arms 10 can preferably be made of any suitable material and/or combination of materials for providing safe and effective handling. Also, arms 10 may have any appropriate shape or configuration sufficient to accommodate a variety of different applications in use.
[0025] Referring to FIGS. 1 to 4 , in a preferred aspect of the present invention, heatable hair contacting elements 4 selectively cooperate with hair engaging portions 14 to provide additional and/or alternative hair styling options. Contacting elements 4 may be fixed or removable with respect to hair engaging portions 14 and can have any shape, size and/or configuration appropriate for their intended use. For example, contacting elements 4 can have an upper surface 24 that is flat or smooth for straightening hair, corrugated for crimping hair, or otherwise formed to provide other hair styling effects.
[0026] Contacting elements 4 can have an engaging groove 26 as shown in FIG. 4, preferably in a lower surface 28 thereof and with guides 29 , for cooperating with a complementary engaging tongue 30 associated with hair engaging portions 14 as shown in FIG. 1. The tongue 30 can be either in and/or on the paddles. The tongue and groove connection can be used to facilitate the interchangeability of the various contacting elements 4 . Also, in one aspect of the present invention tongue 30 and groove 26 can be thermally interactive such that heat generated via hair styling tool 2 can be selectively transferred to an engaged contacting element 4 via tongue 30 of hair engaging portions 14 . Further, the tongue and groove connection can inhibit or prevent vertical displacement of contacting elements 4 with respect to hair engaging portions 14 . In another aspect of the invention, hair engaging portions 14 can each have a lock/release mechanism 32 suitable to selectively secure contacting elements 4 in position and, in combination with the tongue and groove connection, prevent any lateral displacement of contacting elements 4 with respect to hair engaging portions 14 .
[0027] Contacting elements 4 can also have a fastener 34 with a locking element 32 for cooperating with a lock/release mechanism 33 associated with hair engaging portions 14 as shown in FIG. 1, to removably connect contacting elements 4 to hair engaging portions 14 . Fastener 34 can additionally and/or alternatively be suitable to removably connect frames 6 to contacting elements 4 and/or hair engaging portions 14 . For example, in one aspect of the present invention, hair engaging portions 14 are each provided with one or more flanges 36 , shown in FIG. 1. Flanges 36 are preferably configured so that contacting elements 4 and/or frames 6 can be snap-fit thereover. Other configurations may additionally and/or alternatively be used.
[0028] Referring to FIGS. 1 and 5 to 7 , in a preferred aspect of the present invention, frames 6 preferably have two clamping elements, a first upper clamping element 38 and a second lower clamping element 40 . First clamping element 38 preferably has a grasping portion 39 and can preferably be removably connected to hair styling tool 2 . Second clamping element 40 can preferably be pivotally connected to first clamping element 38 via a pin 41 that cooperates with a socket 43 in first clamping element 38 . Preferably, first and second clamping elements 38 , 40 can selectively, securely hold or retain cloth 8 therebetween. For example, in one aspect of the present invention, first clamping element 38 can have one or more first securing elements 42 , best shown in FIG. 1. Also, second clamping element 40 can likewise have one or more second securing elements 44 , best shown in FIG. 1. First securing elements 42 can preferably penetrate cloth 8 and traverse second securing elements 44 . While second securing elements 44 can preferably receive first securing elements 42 when first clamping element 38 and second clamping element 40 are clamped or closed together. Thus, cloth 8 can preferably be secured between first and second clamping elements 38 , 40 via first and second securing elements 42 , 44 , and can be operatively connected to hair styling tool 2 via frames 6 .
[0029] It is noted that other configurations and/or arrangements may additionally and/or alternatively be used to operatively connect cloth 8 to hair styling tool 2 . For example, snaps, clips, Velcro™ straps, or any similar type connection may be used. Alternatively, cloth 8 can be modified to facilitate cooperation between hair styling tool 2 and cloth 8 . For example, cloth can be formed into a sock (not shown) with an open end suitable to slip over the hair styling tool in an operatively appropriate manner.
[0030] Preferably, each contacting element 4 is formed of a suitable heat conductive material such as, for example, a metallic material and/or a ceramic material.
[0031] Cloth 8 , as best shown in FIG. 7, is preferably suited to be selectively secured or clamped between clamping elements 38 , 40 of each frame 6 . One or more pieces of cloth 8 may be used as desired for accomplishing a desired hair styling effect. Cloth 8 can have any of a variety of shapes, sizes and/or configurations appropriate to effectively cooperate with frames 6 and/or hair styling tool 2 . Cloth 8 can be single-layered or multi-layered. Cloth 8 is preferably appropriately absorbent to selectively absorb and/or hold, as desired, any of a variety of different substances (e.g., hair treatments). Cloth 8 can be disposable and/or reusable. Cloth 8 can be made of a paper and/or fabric construction. The absorbency and heat resistance characteristics associated with cloth 8 are preferably sufficient for its intended use. For example, hair styling tool 2 may operate at temperatures in excess of 200° C. Thus, cloth 8 is preferably able to safely withstand these temperatures. Also, cloth 8 is preferably able to effectively absorb substances of a variety of different consistencies and/or viscosities.
[0032] Having described some of the preferred aspects of the present invention, the method for implementing the present invention to efficiently and effectively apply a substance to selected portions of a person's hair includes providing a hair styling tool such as, for example, the styling tool previously described herein. The styling tool is preferably operatively connected to contacting elements 4 , securing frames 6 , and cloth 8 .
[0033] Referring again to FIG. 1, in use, one or more pieces of cloth 8 are preferably secured to hair styling tool 2 via securing frames 6 . That is, the one or more pieces of cloth 8 are preferably sandwiched between clamping elements 38 , 40 of each frame 6 such that securing elements 42 , 44 thereof can securely hold the one or more pieces of cloth in place. Each frame 6 can be connected to hair styling tool 2 at any time, as desired, before and/or after cloth 8 is secured to frames 6 . Frame 6 may be connected to hair styling tool 2 in any suitable manner (e.g., fasteners 34 and/or flanges 36 ). The one or more pieces of cloth 8 can have thereon the desired hair treatment substance. Cloth 8 may be provided with the desired hair treatment substance at any time, as desired, before and/or after cloth 8 is secured to frames 6 .
[0034] Once the one or more pieces of cloth 8 are properly secured to frames 6 , and the frames are properly secured to the hair styling tool 2 , the hair styling tool, which preferably has a heater (not shown) operatively connected to a power source (not shown) via a power cord 15 , can be activated to provide heat either directly to the one or more pieces of cloth 8 or indirectly thereto via contacting elements 4 .
[0035] The hair treatment substance can then be applied to selected portions of the person's hair via the one or more pieces of cloth 8 in combination with hair styling tool 2 as desired. Thus, the one or more pieces of cloth 8 preferably cooperate with hair styling tool 2 so that a heat-activated substance contained in the pieces of cloth can be activated while in contact with the selected portions of hair during use of the hair styling tool to apply the hair treatment substance as desired to the hair.
[0036] The present invention having been thus described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit of the present invention as defined herein. | There is provided a hair treatment system and method that utilizes a hair styling tool suitable for styling hair and an application cloth suitable for applying a substance to selected portions of a person's hair. The application cloth and the hair styling device cooperate, via hair contacting elements and/or a securing frame, to provide an effective, efficient and versatile system that facilitates the effective transfer of any of a variety of different hair treatment substances in accordance with various specialized or required hair styling or conditioning procedures. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to and the benefit of U.S. provisional patent application Ser. No. 61/515,258 filed Aug. 4, 2011, which application is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The invention relates to beam guiding apparatus in general and particularly to a proton beam guiding apparatus that does not require an applied electromagnetic field to control the beam.
BACKGROUND OF THE INVENTION
Since the 1960s a small but stable element in radiation therapy has involved MeV ion beams. At Lawrence Berkeley Laboratory and Harvard University (and subsequently many other places) accelerators previously used for nuclear physics pioneered the use of this technique. Proton therapy as well as ion beam therapy have become very effective therapeutic tools and are becoming more and more widespread worldwide. In the LA area, the group at Loma Linda Hospital has established a solid reputation for their cancer treatment program, which is based on high energy (MeV) proton beams.
One substantial advantage of such ion beams is that the radiation dose is more localized than for x-rays or electrons. The reduction of the scattering of the beam permits irradiation volumes with sharper boundaries. In particular the Bragg peak at the end of the range permits a relatively high dose to the region of interest.
Bent crystals have been efficiently used for channeling of GeV particle beams at accelerators, as described by V. M. Biryakov, Yu. A. Chesnokov & V. I. Kotov, “Crystal Channeling and its Application at High Energy Accelerators,” Springer, Berlin 1997.
There is a need for systems and methods that can provide proton beams having very narrow beam width.
SUMMARY OF THE INVENTION
According to one aspect, the invention features a proton beam guidance apparatus useful to provide a micro-beam of protons. The proton beam guidance apparatus comprises a proton beam guide having defined therein an enclosed channel having scattering centers located on an interior surface of the enclosed channel, the enclosed channel having an internal cross sectional dimension of tens of nanometers or less, the enclosed channel configured in the shape of a helix, the proton beam guide having an input port configured to accept protons from a proton source, and having an output port configured to provide a proton beam having a beam width of a dimension comparable to the internal cross sectional dimension of the enclosed channel. The proton beam is guided by scattering interactions with atomic scatterers on (or part of) the surface of the enclosed channel.
In one embodiment the proton beam guide is fabricated from a glass.
In a different embodiment the proton beam guide is fabricated from an insulator having a conductive coating applied to a surface of the insulator.
In one embodiment, the proton beam guide is fabricated from an electrically conductive material. The electrically conductive material can be a surface coating on a non-conducting material like glass.
In another embodiment, the electrically conductive material comprises a metal.
In yet another embodiment, the electrically conductive material comprises carbon. In some embodiments the carbon is present as a carbon nanotube.
In still another embodiment, the proton beam guide comprises a plurality of atoms having atomic number Z above 72 located on the interior surface of the enclosed channel surface of the enclosed channel.
In a further embodiment, the enclosed channel is an annular channel. In still another embodiment, the annular channel has a circular cross section.
According to another aspect, the invention relates to a proton beam guiding method. The method comprises the steps of providing a proton beam guide having defined therein an enclosed channel having scattering centers located on an interior surface of the enclosed channel, the enclosed channel having an internal cross sectional dimension of tens of nanometers or less, the enclosed channel configured in the shape of a helix, the proton beam guide having an input port configured to accept protons from a proton source, and having an output port configured to provide a proton beam having a beam width of a dimension comparable to the internal cross sectional dimension of the enclosed channel; applying a supply of protons having energy measured in tens to hundreds of MeV to the input port of the proton beam guide; and receiving from the output port of the proton beam guide a beam of protons having a beam width of comparable dimension to the internal cross sectional dimension of the enclosed channel. The proton beam is guided by scattering interactions with atomic scatterers on (or part of) the surface of the enclosed channel.
In one embodiment, the method further comprises the step of measuring the received proton beam with respect to one or more of a fluence, an energy, a dose, and a beam width.
In another embodiment, the guiding method further comprises the step of using the received proton beam to provide medical treatment to a patient.
In yet another embodiment, the proton beam guide is fabricated from a glass.
In a further embodiment, the proton beam guide is fabricated from an insulator having a conductive coating applied to a surface of the insulator.
In yet another embodiment, the proton beam guide is fabricated from an electrically conductive material. The electrically conductive material can be a surface coating on a non-conducting material like glass.
In still another embodiment, the electrically conductive material comprises a metal.
In a further embodiment, the electrically conductive material comprises carbon. In some embodiments the carbon is present as a carbon nanotube.
In yet a further embodiment, the proton beam guide comprises a plurality of atoms having atomic number Z above 72 located on the interior surface of the enclosed channel.
The foregoing and other objects, aspects, features, and advantages of the invention will become more apparent from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the invention can be better understood with reference to the drawings described below, and the claims. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views.
FIG. 1 is a perspective view of a graph of a helix with x y, and z axes shown in a right-handed coordinate system.
FIG. 2 is a graph illustrating the calculated path of propagation of a 20 MeV proton within a bent helix of Au scattering atoms, with bending radius of 10 8 Angstrom (1 cm), which operates according to principles of the invention. The diameter of the helix is 10 Angstroms (1 nm).
FIG. 3A is a graph of the initial part of the path of the incoming proton, showing the points of interaction (indicated by triangles) with the bending helix on which the atomic scatterers are placed. The curves representing the top and bottom of the helix are shown in the figure.
FIG. 3B is a graph showing the details of the second interaction point, the first point on the bottom of the helix. The model takes into account proton motion that comprises 226 individual interactions with adjacent spheres representing atoms. The centers of the spheres are placed on the curve denoting the helix.
FIG. 4 is a graph showing the calculated path of a 20 MeV proton within a 10 nm diameter glass helix of atomic scatterers, up to the point where it is scattered out of the helix. The bending radius of the helix is 10 cm while the initial angle of inclination with the z axis is 0.036 degrees.
FIG. 5 is a graph showing the penetration length of a 20 MeV proton beam within a 10 nm diameter bent glass helix, as a function of the incident proton angle with the z axis. The bending radius of the helix is 10 cm. In addition to the data points, a smooth curve is provided to guide the eye.
FIG. 6 is a graph showing the calculated path of a 20 MeV proton within a 10 nm diameter helix of tungsten atoms that operates according to principles of the invention.
DETAILED DESCRIPTION
The present description outlines a class of apparatus and a method for creating submicron beams of 20 MeV protons for very localized medical treatment, which is expected to achieve sub-micron dimension treatment regions. For ease of exposition, such apparatus will be referred to as a proton beam guidance apparatus. In other embodiments, the proton energies of interest range from tens to hundreds of MeV. The apparatus relies on a helical path (an enclosed channel) that comprises scattering sites provided by atoms. The enclosed channel is bent into a smooth curve (e.g., a portion of a circle) so that it guides the proton beam gradually and deflects the protons, so as to bend the proton beam. The proton beam undergoes atomic scatterings in this gradually curved enclosed channel, thus being deflected.
In a preferred embodiment, the atoms are heavy atoms such as tungsten (Z=74) and gold (Z=79), where Z represents atomic number, or number of protons present in the atomic nucleus. Other elements that are expected to be useful include Hf (Z=72), Ta (Z=73), Re (Z=75), Os (Z=76), Ir (Z=77) and Pt (Z=78). In general, elements having atomic number above 72 are expected to be good scatterers of protons, although some of them may have other properties that render them less preferable for use, such as chemical reactivity or radioactive properties.
The use of a helical path provides a way to create such submicron beams that uses no electromagnetic focusing elements near the site of the irradiation, which makes it substantially more flexible to use in practice. Another contemplated application of these beams lies is in the very active field of microbeam irradiation of individual and bystander cells.
Two contemplated applications include using proton beams in highly localized cancer therapy treatment and using the nanometer dimension proton beams for studying the irradiation effects inside individual cells on the submicron scale as well as the effect of this irradiation on nearby cells. Another contemplated application is a method of digging trench profiles, e.g. nanogrids, using particles transmitted through such nanopipes or nanotubes.
As explained in the following description, we exploit the phenomenon of “channeling”, in which ions are steered by grazing collisions with the atoms in a crystalline lattice or with atoms aligned along a desired propagation path. Recently, nanotubes made from elements heavier than carbon permit channeling to be used to steer high energy ion beams which can have application in cancer therapy, among other potential uses. Based on the results of our simulations, we expect this to be successful.
The Helix
Parametric equations are convenient for describing curves in higher-dimensional spaces. A helix can be represented by the three equations Eqn (1)-Eqn (3) using the parameter t (for example representing time).
x =α cos( t ) Eqn (1)
y =α sin( i ) Eqn (2)
z=bt Eqn (3)
The helix represented by Eqn (1)-Eqn (3) has a radius of a units and rises by 2πb units per turn. FIG. 1 is a diagram illustrating a helix. Equations (1) and (2) are the equations that can be used to represent circular motion in a plane. Equation (3) provides a linear change in the value of z with time. The helix can also be represented in parametric form as
r ( l )=( x ( l ), y ( l ), z ( l ))=(α cos( l ),α sin( l ), bl ). Eqn (4)
We have investigated by simulation the possibility of bending and steering proton beams of medical and biological interest by means of high atomic number (Z) metallic nanotubes. The proton energies involved here are of the order of tens of MeV. A particularly interesting application of this research lies in the delivery of therapeutic proton beams to tumors, as well as for producing beams for single cell level studies of proton irradiation effects. The metallic nature of the nanotube is of importance, as will be discussed below.
Model
A computer program has been written which describes the following situation. The results obtained in using the computer program to model the interaction of a proton beam with an annular guiding structure are described hereinafter.
In the model employed here, a nanotube having atomic scattering sites situated at the inner surface of an annular channel in the shape of a helix of atoms is used as a guide for a beam of energetic protons. As presently contemplated, the nanotube can be fabricated from a single chemical substance, such as a metal; from a compound chemical substance, such as an oxide glass; or from a combination of substances, such as a support fabricated from a material such as carbon (e.g., a carbon or graphene nanotube) that is decorated with heavy atoms that serve as scattering sites on the inner surface of the annular volume.
The nanotube has been approximated by a long thin annulus that takes the form of a helix, on which the target atoms are spread out in a screw-like manner. For simplicity, the annulus, which has a centerline which describes a helix, may be referred to as a helix. The atoms are approximated by spheres, with which the protons interact, and are repelled gently, since the collisions are essentially grazing collisions. In a further analysis, packets of annular nanotubes that are each bent into helical configuration, and that are adjacent to each other, have also been modeled.
In one model, a single bent glass capillary tube is represented by alternating Si and O atoms wrapped around a helix in rings, in a screw like manner. The atoms in the calculation are represented by small spheres of radius 0.7 A. The radius of the ring is 50 A, while 200 atoms are spread out in an equally spaced manner along the circumference of the ring. Thus, the distance between the center of an atom to the center of its nearest neighbor is 1.57 A, close to the value of 1.6 A in glass. The distance between the centers of the advancing rings along the screw like helix is 2 A.
In the present calculation the binary collision approximation is used, with protons interacting individually with each target atom they encounter. This approximation is widely used in the literature in connection with channeling as well as radiation defect studies. See for example M. T. Robinson & I. M. Torrens, Physical Review B 9, 5008 (1974) and A. Mertens & H. Winter, Phys. Rev. Lett. 85, 2825 (2000). A simplified screened potential was used, denoting b as the impact parameter and R the atomic radius of the scatterer, the scattering angle θ is given by Eqn (5), discussed by I. Nagy et al., Phys. Rev. A 78 012902 (2007),
tan 2 (θ/2)=[ Ze 2 /( bmv 2 )] 2 [(1−( b/R ) 2 ]/[1−( Ze 2 /R )* mv 2 ] 2 Eqn (5)
Omitting the second term in square brackets on the right hand side (RHS) gives the Rutherford scattering formula for a bare charge. After traversing the atomic sphere, the proton is deflected by the angle θ in the direction normal to its trajectory. The change of the angle is carried out in the plane of the incoming proton trajectory and the line connecting the center of the sphere to the point where the proton leaves the sphere.
The bending radius of the helix in the present calculation is R b =10 cm, the proton energy is 20 MeV, while the radius of the rings comprising the helix is R h =5 nm. The proton initially moves in the z direction, the direction of the initial major axis of the helix, with a very slight inclination angle Θ towards the x direction. The calculation is initiated by forcing the proton to interact with the first atom of the helix at its external edge.
As discussed in T. Nebiki et al., Nucl. Instrm. & Meth. B 266, 1324 (2008), it is believed that the charging-up of the capillary tube walls will be minimized. It is believed that the charging effect on the particle trajectory is negligible for the problems encountered here. Thus, particle deflection is only achieved by small angle scattering with the atoms comprising the helix.
In one embodiment, the helix is assumed to be made up of gold (Au) atoms. As will be further explained, a structure having an annulus that has a centerline that describes a helix can have heavy atoms of other elements on its inner surface. The helical annulus itself does not have to be constructed exclusively of heavy atoms, but can have heavy atoms present on its inner surface, so long as sufficient heavy atoms are present at the required locations on the inner surface. The scattering angle is calculated in accordance with a screened Coulomb scattering law, assuming a binary collision model with each of the atoms on the helix. The program searches for the next interaction with a given atom on the helix and continues this procedure until the proton escapes the helix. In one embodiment, protons that escape by passing through the wall of the helix, or protons that are scattered out of the tube, can be “caught” by an adjacent tube and will continue to propagate. An investigation of the latter step has been made.
In FIG. 2 we plot the propagation of a 20 Me V proton as curve 210 within an annulus that is helical in shape, with a bending radius of 10 8 Angstrom (1 cm). The diameter of the annulus is 10 Angstrom. The proton enters the helical annulus as shown in FIG. 2 at an angle of 0.026 degrees with respect to the z axis, where it interacts with the first atom on the surface (for example the top side) of the helical annulus at the inward edge of the atomic sphere. FIG. 2 demonstrates for this specific problem, the successful guiding of the proton up to 120 microns in the direction of propagation while being bent by almost 7000 Angstroms in the transverse direction. For the example illustrated in FIG. 2 , the calculation terminated due to memory constraints. It is believed that in the absence of the memory constraints, it would have been observed that the proton could have continued to propagate. It is observed that by decreasing the angle of incidence, the proton penetration and bending increases further and further. Note that this has model indicates that this propagation can be accomplished without magnets or strong external fields.
In one embodiment, the capillary can be a glass capillary tube. We have demonstrated by modeling that 20 MeV protons can be guided within a 10 nm diameter helical tube, for a distance of 0.55 cm, with the beam bending in the transverse direction by 0.16 mm. It is expected that larger distances of travel of the beams will be achievable.
We show at first on a local scale how the proton oscillates from one side of the capillary to the other, also clarifying the geometry of the problem.
FIG. 3A gives the initial part of the path of the incoming proton, showing the points of interaction with the helix of scatterers. Curve 302 represents the upper side of the annular helix and curve 304 represents the lower side of the annular helix. Triangles on each curve represent the location of scatterers. The second point of interaction, the first at the bottom line of the helix, is modeled using 226 individual interactions between a proton and a scatterer. A blowup of this interaction is given in FIG. 3B , where the proton motion, represented by solid triangles 310 , is plotted as the proton approaches the lower surface of the helix, represented by line 320 , and is then repelled, after which it interacts with the other (top) side of the helix.
The parameter in the results presented here below is the initial inclination angle, Θ, of the incoming proton trajectory with the z axis. The result for 0.036 degrees is presented in FIG. 4 , where the line 410 represents the path of the proton within the helix. This path comprises 67,100 individual interactions with different target atoms along the bent helix. The striking feature here is the deep penetration of the beam of up to 0.55 cm, with the beam bending in the transverse direction by 0.16 mm. These calculations show that substantial penetration of a proton beam even in strongly bent glass capillaries could be obtained.
In FIG. 5 we present the proton penetration length as a function of the initial inclination angle Θ. In addition to the data points, a smooth curve 510 is provided to guide the eye. As expected, the depth of penetration decreases with increasing Θ, at relatively large initial inclination angles. However, decreasing Θ below 0.03 degrees, causes the penetration distance to decrease to 0.3 cm. This result indicates that there is a well-defined acceptance angle for propagation of protons through the annular nanotube.
FIG. 6 is a graph showing the calculated path 610 of a 20 MeV proton within a 10 nm diameter helix of tungsten atoms that operates according to principles of the invention.
A subsequent step introduces adjacent surrounding nanocapillaries and in so doing constructing a bundle of capillaries. In such a configuration, it is expected that protons leaving the central capillary can be captured in and transported by any of the surrounding adjacent capillaries. A calculation in which a ring of six parallel capillary tubes surrounded the central tube was carried out. In some of the cases studied, capture occurred, with maximum transmitting path lengths of the order of 0.1 μm until the proton scattered out of the second capillary. This could be understood, since deep penetration occurs only at very small grazing angles. However, we cannot rule out the important possibility, that with several hundred surrounding capillaries, appreciable additional transport could be obtained. A multi-capillary system similar to the well-known neutron and X-ray lenses, could be of particular importance. Specifically, if the bent capillaries are arranged in a pattern, such as a circular pattern, so that all transmitted nanobeams point at the same focus of nanometer size, one might be able to enhance the focal proton beam intensity greatly.
While the present disclosure provides an analysis for a proton beam guidance apparatus having an annular (e.g., circular cross section) channel shaped as a helix, it is expected that an enclosed channel of a different cross sectional shape, having two opposed reflective surfaces at a top surface and a bottom surface of the channel, could also be used to provide a similar proton beam guidance apparatus. For example, an enclosed channel shaped as a helix having a square cross section, or a hexagonal cross section, could also serve to construct a proton beam guidance apparatus according to principles of the invention.
After a proton beam has traversed the proton beam guidance apparatus, there can be reasons to measure some of the properties of the exit beam. The measurements can include measuring the received proton beam with respect to one or more of a fluence, an energy, a dose, and a beam width. The results of the measurement can be used to control the beam so that a patient is given appropriate treatment. In one embodiment, the measurements can be made by first placing the measurement apparatus in the location where the patient would be situated, and after confirming that the beam is operating as intended, removing the measurement apparatus and placing the patient in position to be treated.
Applications
We now enumerate some of the medical and biological applications of the proposed metallic proton guiding nanotube, which we believe to be novel.
Radio Surgery Applications
One goal is to be able to deliver proton or ion beam radiation to a specific destination. Healthy tissues would be expected to absorb less radiation using this delivery method as compared to conventional proton therapy of tumors, because the sharper definition of the proton beam allows it to avoid more precisely healthy tissues surrounding the tumor. We believe that this is a novel form of brachytherapy, with the advantage of no need for radioactive sources. The dose and range could also be more accurately controlled than with the cumbersome and difficult to handle radioactive source. Electrical feedback of irradiated areas by using a conductive nanotube as both a delivery apparatus and a probe is expected to be of additional value. It is our expectation that the systems and methods disclosed put a radiation scalpel in the hands of a radiologist or surgeon.
Microbeam Irradiation of Individual Cells
Investigations of the radiation action on cells at the submicron scale have been a very active field of research for over the past 15 years. We have investigated by modeling the effects of radiation in individual cells, permitting also the possibility of investigation on the subcellular level, as well as on the non-targeted bystander cells. The current methods struggle with collimation of such fine beams, using glass capillaries which give beams having a diameter of the order of microns, for example as described by N. Stoltefoht et al. “Dynamic properties of ion guiding through nanocapillaries in an insulating polymer”, Phys. Rev. A 79, 022901 (2009). Glass capillaries also have the disadvantage that they fluoresce under irradiation. In addition most publications deal with KeV energy beams, with pronounced oscillations in the time evolution of the transmission profiles. Electromagnetic collimation is now also being attempted.
Additional papers on similar research include N. Stoltefoht et al., Phys. Rev. A 76, 022712 (2007) and T. Ikeda et al., J. Phys. Conf. Series, 88, 012031 (2007).
Besides the much smaller beam size, the conductive tube described here would be favorable since the proton emitting needle has a well-defined potential, thus avoiding disturbing bio-effects on neighboring living matter, which might arise by the electrostatic charging up of the tube. In some embodiments the tube can be metallic. In some embodiments the tube can be made of carbonaceous material such as carbon nanotubes or grapheme. Furthermore, in parallel to proton injection, the conductive tube can be used to probe the local potential and currents in the biological samples at the point of proton impact. These possibilities also apply to therapeutic applications, as will be discussed below.
Production of metallic nanotubes has been and is an active area of research. In particular, both gold and platinum (Pt) serve our purpose well. Gold tubes having a diameter of 1 nm and about 6 microns of length have been fabricated, as described in C. R. Martin et al. “Investigations of the transport properties of gold nanotube membranes” J. Phys. Chem. B 105, 1925 (2001). It is expected that heavy metal nanotubes of tens of microns and more in length will be readily available in the near future.
Advantages of such narrow conductive tubes include better definition of beam diameter than wider tubes, and absence of fluorescent signal from conductive tubes. These advantages can be expected to provide better physical resolution with regard to beam impingement, and the possibility of sensing fluorescence from irradiated samples without having to separate those signals from spurious fluorescence generated by interaction of the beam with the tube.
Definitions
Unless otherwise explicitly recited herein, any reference to an electronic signal or an electromagnetic signal (or their equivalents) is to be understood as referring to a non-volatile electronic signal or a non-volatile electromagnetic signal.
Theoretical Discussion
Although the theoretical description given herein is thought to be correct, the operation of the devices described and claimed herein does not depend upon the accuracy or validity of the theoretical description. That is, later theoretical developments that may explain the observed results on a basis different from the theory presented herein will not detract from the inventions described herein.
Any patent, patent application, or publication identified in the specification is hereby incorporated by reference herein in its entirety. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material explicitly set forth herein is only incorporated to the extent that no conflict arises between that incorporated material and the present disclosure material. In the event of a conflict, the conflict is to be resolved in favor of the present disclosure as the preferred disclosure.
While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be affected therein without departing from the spirit and scope of the invention as defined by the claims. | A proton beam guidance apparatus and a method of providing proton beams having sub-micron beam width and MeV energies. The apparatus is a structure having an enclosed channel that can reflect or guide protons by grazing incidence interactions. The enclosed channel is in some embodiments an annular channel. The enclosed channel is shaped to provide a helical path for each proton in the beam. Protons are provided to an input port of the channel, and after multiple grazing incidence interactions with the walls of the channel, are provided as an output beam having dimensions comparable to the cross sectional dimensions of the channel. The channels can have cross sectional dimensions of tens of nanometers or less. No externally applied electromagnetic fields are needed to guide the proton beam. Contemplated applications include use of the exit proton beams to provide medical treatment to patients. | 7 |
FIELD OF THE INVENTION
The invention relates to a method and apparatus for monitoring run/stop conditions of a yarn in a knitting or warping machine.
BACKGROUND OF THE INVENTION
In order to detect yarn breakage in textile machines, like knitting or warping machines, a yarn feeler is known which is able to output a logical final output signal indicating the run/stop conditions of a yarn actuating a transducer. A typical structure of a yarn feeler includes the transducer, a variable gain amplifier, a detector/comparator operating with a threshold in order to gain a detected run signal and an output filter operating with a predetermined time delay to output final output signals. The electrical run input signal of the transducer will mainly be generated on the basis of the yarn speed but also on the basis of other parameters like yarn tension, yarn linear specific mass, yarn count, yarn flexibility, yarn surface roughness, electrostatic charge of the yarn, etc. A variable gain amplifier is used because the amplification gain needs to be adjusted towards a minimum just assuring a stable output signal irrespective of parametric natural influences. A gain amplification which is too strong results in a poor time definition of the output and an output sensitive to spurious yarn motions simulated by external noise. A gain amplification which is too low results in an erratic output signal despite a correct run of the yarn. In the known yarn feeler the variable gain amplifier is adjusted manually. However, this is not well accepted by the users, because such empirical adjustment or trimming procedures are a waste of time and require particular skill, especially if a plurality of yarn feelers are installed at a machine. On the other hand, there is always a large risk that the adjustment is not carried out correctly.
It is an object of the invention to provide a method as disclosed and a yarn feeler which operates on the basis of this method, both leading to the highest quality of yarn monitoring, i.e. to avoid a poor time definition of the output signal, to achieve output signals insensitive to external noise, and to safely avoid an erroneously generated final output stop signal in case of a proper run of the yarn.
According to the method of the invention, the gain amplification permanently and automatically is adjusted to an optimum, namely a minimum just sufficient to ensure stable final output signals. No manual adjustments are necessary. Since the yarn feeler is adapting itself to an optimum sensitivity assuring stable final output signals, poor time definitions of the output signals and influences of external noises are avoided as well as an erroneously generated final output stop signal in case of properly running yarn. Said minimum is permanently adapted to instantaneously cope with all influencing parameters.
The yarn feeler does not need any manual trimming or adjustments since it automatically is seeking an optimum gain amplification. In knitting or warping machines having a plurality of such yarn feelers, the quality of each yarn feeler in view of its operation behaviour is enhanced significantly. The improved monitoring quality is achieved without the need for adjustment procedures carried out by operators. Of particular advantage is that a change of the yarn count or the yarn quality does not need any preparatory work at the yarn feelers since each yarn feeler has its own self-learning control adapting automatically to the instantaneous conditions and influencing parameters. The control strategy used is an automatic gain control technique interfering in a regulating fashion at the variable gain amplifier in order to maintain the final output signal within specified limits and independently of the amplitudes of the run input signal. A prerequisite is that the control band width is larger than the band width of the input run signal variation such that the control is able to follow these natural parametric variations. The control is operating with a constant reaction time. In order to avoid false output stop signals during normal run of the yarn, the output signals are filtered with a time delay slightly longer than the reaction time of the control. Said additional delay is acceptable for applications where yarn speed variations are moderate and also where the top speed of the yarn during the run is predeterminably moderate as on knitting or warping machines. Any type of electronic transducer can be integrated into the yarn feeler like piezo-electronic, electrostatic or other transducers. A final prerequisite of a correct function is that the band width of signals caused by yarn breakages is by far larger than the control band width. A yarn breakage will lead to an input run signal drop occurring much faster than the reaction time of the control so that a correct final output stop signal will result safely.
Particularly in knitting or warping machines, the natural parametric variations are slow enough, since the yarn starts its run with a mild acceleration, runs for a long time at essentially constant speed, until it then stops after a smooth deceleration. The slowness of the physical phenomenon provides enough time to adjust the gain amplification without the danger of generating false final stop signals, namely by filtering with an acceptable time delay prior to putting out the final output signal.
It is advantageous to compare the amplified run input signal with a predetermined threshold in order to output a detected run signal, on the basis of which the final output signal can safely be generated, but which simultaneously can be used to control the gain amplification such that the amplified run input signal is just higher than the threshold. As already mentioned, the mutually related band widths of the control and the natural variations of the run input signal allow the control to follow such variations in order to reliably achieve an essentially stable detected run signal, fluctuations of which are filtered by the output filter as long as such a fluctuation is not caused by a fast breakage drop.
According to a further aspect of the method, the variations of the gain amplification are controlled independently from the amplitudes, of the run input signal in order to keep the final output signal within specified limits.
Said AGC-control strategy can be carried out reliably and permanently by generating an amplification gain control signal on the basis of the detected run signal, to which amplification gain control signal the amplifier is responding by varying its amplification factor or sensitivity accordingly. As soon as the detected run signal shows the tendency to rise or to fall, the gain amplification will be lowered or raised accordingly.
Since in the case of a piezo-electric transducer almost all parameters originating from the yarn and its run are essentially constant, except the yarn tension decisive for the run input signal, the amplification gain control signal generated on the basis of the detected run signal is reflecting relatively precisely the control effort necessary to compensate for tension variations. Said interrelationship can be used to measure the instantaneous yarn tension.
In order to generate a reliable, logical, detected run signal or run/stop signal it could also be necessary to vary the detection threshold.
Since a final output stop signal also can occur within the correct operation cycle of the machine equipped with the yarn feeler, namely when the yarn is stopped as intended but not due to a yarn breakage, it is useful to evaluate the final output signals representing the run/stop conditions of the yarn in view of a sync-signal associated with normal or correct run/stop conditions. A final output stop signal-representing a yarn breakage leads to a stop of the machine when the associated sync-signal is indicating that the yarn should run.
In the yarn feeler it is advantageous to have a reaction time of the AGC-control strategy weak enough to compensate for natural parametrical fluctuation or spikes in the detected run signal, which fluctuations, as mentioned, occur slowly enough. Since to the contrary, a yarn breakage leads to a sudden drop of the yarn input signal, the then detected run signal cannot be maintained stable further on, and even the output filter cannot filter out said sudden drop, such that in the case of a yarn breakage a reliable final output stop signal will be generated.
The reaction time of the amplification gain control circuit ought to be adapted to the compensation of natural parametrical fluctuations.
Any type of transducer can be used for the yarn feeler. Of particular advantage are piezo-electric or electrostatic transducers which operate reliably and safely.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will be explained with the help of the drawings, in which:
FIG. 1 shows a yarn supply and intake position of a knitting machine;
FIG. 2 shows a block diagram of a yarn feeler as used in FIG. 1; and
FIG. 3 shows several superimposed diagrams representing the method of operation of the yarn feeler.
DETAILED DESCRIPTION
As an example of a yarn consuming textile machine in FIG. 1 a knitting machine K its shown, consuming a yarn Y intermediately stored at yarn feeder F. Yarn feeder F is equipped with rotatable storage body 1 carrying a braking ring 2 , below which the yarn is withdrawn through an outlet eyelet and via a yarn feeler A into a knitting station 7 of knitting machine K. Yarn feeder F contains an electrical drive 3 controlled by a control unit 4 and sensors 5 monitoring the yarn store on storage body 1 .
Yarn feeler A is equipped with yarn guide element 6 through which yarn Y while being withdrawn is deflected such that it actuates by its speed and/or tension an electronic transducer T apt to generate signals processed in a control circuit C. Yarn feeler A has the task to, e.g. stop knitting machine K and/or feeder F, in case that a yarn breakage has occurred. Furthermore, final output signals as provided by yarn feeler A have to reliably represent run/stop conditions of the yarn, e.g. in accordance with the operating cycle of the knitting machine or its sync-signal.
Yarn feeler A with its control circuit C is depicted-in FIG. 2 in the form of a block diagram. The output of transducer T (e.g. a piezo-electric or electrostatic transducer) providing run output signal S is connected to a variable gain amplifier VA generating an amplified run output signal, AS in the form of a so-called “coloured” noise signal for a detector/comparator D/C, which in turn outputs a detected run signal DS. For this purpose detector/comparator D/C is operating with a predetermined threshold, i.e. detected run signal DS will be present with running yarn at the output of detector/comparator D/C as long as amplified output signal AS with its level is higher than the threshold. Detected run signal DS is finally filtered by output filter OF and is outputted in the form of a final output signal OS, i.e. either a final output run signal or a final output stop signal. Said final output signals will be considered, e.g. in the control unit or stop motion relay of the knitting machine and/or the feeder, e.g. in correlation to a so-called sync-signal indicating that the yarn Y from yarn feeder F should run or should not run. (A plurality of similar yarn feeders F may be arranged to feed several yarns to the knitting stations of knitting machine K, each having its own yarn feeler A.)
Furthermore, in the control circuit of yarn feeler A of FIG. 2, an amplification gain control circuit AGC is provided and connected to the adjustment inlet of variable gain amplifier VA and also to the output of detector/comparator D/C. Amplification gain control circuit AGC, e.g. in the form of a “blocked oscillator” (oscillation frequency e.g. about 2.5 KHz) is able to generate an amplification gain control signal CS for varying the gain amplification of variable gain amplifier VA or the respective amplification factor or the amplified output signal AS, respectively. The momentary value or level of detected run signal DS is used as a decisive parameter for the generation of amplification gain control signal CS. Amplification gain control circuit AGC is operating with constant reaction time Tc of about 40 ms. Similarly, output filter OF is operating with a predetermined constant time delay To e.g. about 50 ms. I.e., time delay To is at least slightly bigger than reaction time Tc.
The operation of yarn feeler A will be described with the help of FIGS. 2 and 3. Prerequisites for a proper operation of yarn feeler A is the already mentioned difference between To and Tc. Furthermore, the control band width has to be broader than the band width of any natural parametric variations of the run input signal S so that the AGC control will be able to follow these natural parametric variations. A yarn breakage is no natural parametric variation of the run input signal but will cause a run input signal decrease much faster than the reaction time Tc of the AGC circuit.
As shown in the first upper diagram of FIG. 3, in a knitting machine the yarn is starting with weak acceleration, will then run for a long time at constant speed and will finally stop after a smooth deceleration, if no yarn breakage has occurred. In the second part of the curve in the first upper diagram the yarn again starts with moderate acceleration and then runs with essentially constant speed. However, in this case a yarn breakage B is occurring, meaning that the yarn speed is suddenly dropping to zero.
The second curve in FIG. 3 represents the amplification gain control signal CS as generated on the basis of or in order to stably maintain detected run signal DS (third diagram from the top). The second diagram from the top indicates that amplification gain control signal CS is controlled at a maximum when there is no yarn speed and varied indirectly proportional to the yarn speed behaviour. Actually, amplification gain control signal CS by the interference of AGC circuit and during the run of the yarn is adjusted to an optimum floating minimum M just sufficient to maintain a relatively stable detected run signal DS and also to assure a stable output signal OS (fourth diagram from the top). The most advantageous minimum of the sensitivity or the amplification gain in a certain point of time corresponds to a value with which a stable final output signal derived from the yarn speed and other parameters typical of the operating conditions will be generated, and for which minimum the final output signal remains insensitive to spurious yarn motions only simulated by external noise and where there is no danger that an erroneously final output stop signal can be generated even though the yarn is running correctly. As already stated, signal CS is modulated essentially inversely proportional to the run input signal S or the speed profile of the yarn and so that the amplified run output signal AS always will remain just above the threshold as considered in detector/comparator D/C resulting in the signal chain DS, namely the detected run signal DS in the third diagram from the top.
AGC circuit is operating with the above-mentioned reaction time Tc since parametric natural fluctuations cannot be avoided during the run of the yarn. Such fluctuations might cause spikes E in the signal chain of DS, resulting from the fact that the amplification gain control is compensating for such signal fluctuations upon their occurrence and with reaction time Tc. However, since such spikes E will be compensated for in a time shorter than time delay To of the output filter OF, the finally generated output run signals OS will be stable and without any spikes and will allow one to reliably judge the run/stop conditions of the monitored yarn.
The lowest diagram in FIG. 3 is indicating the so-called sync-signal, namely a signal as e.g. emitted by the control unit of the knitting machine and indicating, e.g. for the respective yarn feeder or even the control circuit C of the yarn feeler A when the yarn should run and when not.
If, as shown in the upper diagram, left-side, the yarn is decelerated to stand still as. required by the sync-signal, the end of detected run signal DS occurring in correspondence with the standstill of the yarn will result in final output stop signal (right-end flank of the left signal chain OS) which, however, will not be considered as being critical, e.g. in the control unit of the knitting machine, since this is only a confirmation of an expected stop condition of the yarn as required by the drop of the sync-signal.
When, however, as shown in the right curve of the upper diagram in FIG. 3 (V dropping due to yarn breakage B) the signal drop is occurring so fast that the amplification gain control signal CS is unable to follow and to compensate for this sudden signal drop, the amplified output signal AS will not reach the threshold so that the detected run signal DS will drop accordingly at SDS leading, due to time delay To of output filter OF, to a somewhat delayed final output stop signal SOS of signal chain OS. Since at this point in time sync-signal (lowest diagram in FIG. 3) still is present indicating that the yarn actually still should run, the control unit of knitting machine K immediately recognises final output stop signal SOS as an indication of yarn breakage B and will switch off the knitting machine and/or the feeder.
The applied AGC-control strategy must not allow false final stop signals during the normal operation. Unavoidable, natural signal fluctuations also must not generate a false stop. This is achieved by filtering the detected run signal DS for a time delay To slightly longer than the reaction time Tc of the AGC-circuit. However, this added delay To is acceptable in case of knitting or warping machines operating with relatively slow natural parametric variations, because the slowness of the physical phenomena gives enough time to adjust the sensitivity or the gain amplification by the AGC-control strategy and to avoid the generation of false final stop signals by filtering the detected run output signal DS with said acceptable time delay To prior to output. Furthermore, (second diagram from the top in FIG. 3) the amplification gain control signal CS in case of a piezo-electric transducer T, where all yarn parameters are essentially constant, except the yarn tension, also is actually a measurement of the control effort to compensate tension variations. As such CS can be taken to measure or monitor even the yarn tension.
Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed method and apparatus, including the rearrangement of parts, lie within the scope of the present invention. | A method and apparatus for monitoring run/stop conditions of a yarn, particularly in a knitting or warping machine utilizing a yarn feeler. The yarn feeler includes an electronic, yarn actuated transducer operating with variable gain amplification of run input signals which are further processed to final output signals representing the run/stop conditions. The amplification gain for the run input signal is automatically electronically controlled with a time delay and is adjusted towards a floating minimum which is just sufficient to derive stable final output signals. The, reaction time delay allows compensation for naturally occurring parametric fluctuations of the run input signal, while a sudden drop of the run input signal due to yarn breakage is processed to a final output stop signal. | 3 |
This is a continuation, of application Ser. No. 548,034, filed Feb. 7, 1975 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to plasma tubes and to methods for their manufacture and more particularly to a reliable, low cost plasma tube particularly suitable for use in manufacturing helium-neon electron-excited gas lasers.
In the past it has been common to build envelopes and associated components for helium-neon gas lasers of a borosilicate glass, such as Corning brand Pyrex 7740 or 7052 glass, widely used for laboratory glassware. Such glass has good thermal properties in that it is resistant to thermal shock, has good thermal conductivity, and also has a low coefficient of thermal expansion. However, it is also known that there are few, if any, metals to which borosilicate glasses can be joined without the use of some sort of graded seal or Housekeeper seal. Accordingly, envelopes for gas lasers have generally required the use of expensive glass forming or molding techniques in order to establish the envelope configuration. The required metallic conductor parts have generally consisted of small-wire tungsten seals through a graded seal in 7740 or Kovar metal seals in 7052 borosilicate glass because of the limitations of glass/metal seal technology. Accordingly, prior tubes have usually been made of all glass structural parts, including seals, tip-offs, and the like, through which special non-structural conductive elements must pass in order to establish an electrical discharge. There is, therefore, a need for an improved gas envelope structure plasma tube and method of manufacture which will overcome the foregoing limitations.
SUMMARY OF THE INVENTION AND OBJECTS
In general, it is an object of the present invention to provide a plasma tube and manufacturing method for use in gas lasers which will overcome the foregoing limitations and disadvantages.
It is a further object of the invention to provide a plasma tube structure which is simple to assemble, reliable and which uses readily available, low cost materials.
Another object of the invention is to provide a plasma tube and manufacturing method, particularly for gas lasers, which can be constructed with a small number of manufacturing steps without the use of conventional glass lathes or other expensive forming procedures.
Another object of the invention is to provide a plasma tube and method by which the same can be readily and easily tuned for maximum laser power output.
The foregoing objects are achieved in the present invention by employing the following manufacturing technique and materials. First, a laser capillary having a flange is joined to an outer envelope, as for example, near one end to establish a discharge path, the end being closed by a metal disc anode. The capillary, the outer envelope and the metal disc are all selected from readily available materials which have closely matched thermal properties so that an excellent metal-to-glass seal is obtained. The next step involves inserting a cathode assembly into the outer envelope from the outer end, to which is electrically joined a metal cathode disc having the same thermal properties as the anode. The outer envelope is then fused to the metal cathode disc to thereby define the gas envelope structure, except for end optical elements such as mirrors. In one preferred procedure the fusion of the anode and cathode discs to the outer envelope is accomplished through the known technique of "drop sealing" in which the parts are jigged together with the outer envelope extending below the anode or cathode during each sealing operation. The outer envelope is then heated until it shrinks slightly and fuses into an intimate bond with the respective anode or cathode end disc. The excess outer envelope material drops free under gravity and away from the plasma tube structure during the sealing process.
As preferred materials, the invention calls for the use of potash soda lead glass, available under the trade designations 0120 from Corning or KG12 from Kimble, together with a nickel-chrome-iron alloy (42% Ni, 5-6% chrome, balance Fe) commercially available under the designation Sylvannia No. 4. Less preferred combinations substitute soda lime glass, such as Corning's designation 0080, the more expensive lead silicate glass such as Corning's 0010, and No. 52 nickel alloy (52% Ni, balance Fe) for the respective glass or metal constituent.
The resultant structure is characterized by an elongate, cylindrical glass envelope having a capillary bore carried therein and fused together with the other envelope. A metal anode disc and a metal cathode disc is carried at the respective ends of the structure, the cathode disc being interconnected by suitable means to a cathode carried within the outer envelope at that end.
The entire structure can be readily tuned to maximum output by a technique particularly adapted to the present configuration. The envelope is bent slightly about several radials to its axis until a maxim power output is measured. When a maxim is noted, the bending is released and at least one end disc is inelastically deformed at a very small angular increment to the axis of the capillary by indenting the respective end disc on the maximum radial with a punch as often as necessary to re-establish maximum output.
These and other objects and features of the invention will become apparent from the following description and claims when taken with the accompanying drawings, of which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal view, partly in section, of a gas laser plasma tube constructed in accordance with the present invention;
FIG. 2 is a cross-sectional view of the plasma tube of FIG. 1 taken along the lines 2--2 thereof;
FIG. 3 is a diagrammatic view in cross-section showing the formation of the capillary assembly of the present invention;
FIG. 4 is a diagrammatic view in cross-section showing the capillary, outer envelope, and anode of the plasma tube of FIG. 1 ready for sealing;
FIG. 5 is a perspective, exploded view of the plasma tube of FIG. 1, emphasizing the parts of the cathode assembly; and
FIG. 6 is a diagrammatic view in cross-section showing the plasma tube of FIG. 1 including capillary cathode assembly and outer envelope ready for sealing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a plasma tube constructed in accordance with the present invention is shown in detail and consists generally of an outer envelope 10 having integrally fused therewith a capillary 12 extending coaxially within the tube along a portion of the distance of the outer envelope 10. In general, plasma tubes are constructed in cylindrical geometry for convenience and ease of availability of the basic glassware configurations of which they are made. A flange 14 is formed on the capillary and serves to interconnect the same with the outer envelope. As shown, the flange is preferably located at one end of the outer envelope and capillary tube and is in the shape of a funnel or flared structure and is sealed to envelope 10 to effectively prevent any electron discharge path from existing through the structure other than through the capillary itself. Although the capillary flange is shown as fused at one end, and at an end of the envelope the flange may be located at other positions, as for example, at some intermediate position. An anode 16 is fused to the end of the capillary flared portion and the wall of the outer envelope.
A cathode assembly 18 is positioned in the other end of the outer envelope and extends inwardly into a slightly overlapping relationship with the free end 20 of the capillary. The cathode assembly 18 includes a spider-like member 22 at its free end which positions a hollow aluminum, cylindrical cathode 24 symmetrically in a radial sense within the tube and also supports the cantilevered end 20 of the capillary against movement if the plasma tube becomes subjected to large vibration or other inertial forces. The other end of the cathode assembly terminates in a spring positioning clip 28 which is fused and electrically connected to a cathode end disc 30 under mechanical pressure or brazing, the latter being fused into the respective end of the outer envelope 10. In a typical appliction as, for example, in constructing a helium-neon laser, each of the disc members is provided with a respective one of axially aligned apertures 32, 34. Each of the apertures 32, 34 is closed by one of reflective mirror or partially transmitting mirror 36, 38 which are sealed to the disc with suitable permanent adhesives, such as epoxy cement or fused to the respective disc with glass frit.
The principal length of the cathode assembly which extends within the tube consists of a cylindrical aluminum sleeve 24 and serves, for example, in a cold cathode configuration for excitation of the gas discharge within the plasma tube by dischare of electrons therefrom to the anode.
Each of the end discs is coined as by stamping to provide a region surrounding the aperture having a predetermined radius of curvature. In one application, such a radius of curvature was approximately 8 inches, centered on the axis of the capillary and externally of the tube, and permits the alignment of the end mirrors, if such be used, to a very fine degree by mere shifting of the end mirror within the socket formed in the coined disc. After alignment, the end mirrors 36, 38 are sealed in place as hereinbefore explained. A small diameter piece of metal tubing 40 is fused by being brazed into a second aperture 42 formed in the cathode end disc to permit evacuation and gaseous filling of the plasma tube.
As previously partially explained, the present invention permits the use of readily available low cost glasses for use in manufacture of laser plasma tubes. The principal glasses believed to be most suitable include Corning 0120 (Kimble KG12) or equivalent having a coefficient of expansion of 90 × 10 - 7 /° C. This glass is thermally matched to Sylvannia No. 4 nickel-chrome-iron alloy having a composition of 42% nickel, 6% chrome and 52% iron, also sold under the trade designations Sealmet HC-4 and Carpenter 42-6. Pretreatment by wet hydrogen firing is used to obtain greening of this alloy which permits good fusion between the glass and a surface coating of chromium oxide formed on the alloy. The aforementioned No. 4 nickel-chrome-iron has a coefficient of expansion of 82 × 10 - 7 /° C.
The foregoing materials are preferred for use herein in view of their compatability, stability, low cost, and ready availability. However, substitutions can be made, such as Corning 0080(Kimble R-6) having a coefficient of expansion of 93 × 10 - 7 /° C. Use of 0080 or equivalent may be limited, however, due to shortening of tube life of operation as leaching of sodium from this glass cause cause plasma oscillation, the effect of which increases with time. Alternate metals include No. 52 nickel alloy (52% Ni, balance Fe) and platinum. Use of platinum is obviously prohibitively expensive.
The following glass-metal combinations are also found to be suitable, but involve substantial increase in costs. They are Corning 7052, having a coefficient of expansion of 51 × 10 - 7 /° C, Corning 7720 or Nonex, having a coefficient of expansion of 35 × 10 - 7 /° C, which are sufficiently close to Kovar, having a coefficient of expansion of 48 × 10 - 7 /° C and tungsten, having a coefficient of expansion of 44 × 10 - 7 /° C, respectively, to be useful. As previously stated, Corning 7740 (Pyrex) has no matching metal.
While the foregoing glasses and matching metals normally would be selected on the basic of cost as a principal consideration, there are also factos having to do with the use of frit or solder sealing glasses which are contemplated for use in the future production of so-called hard seals in plasma tubes in which the end mirrors are sealed by a glass-to-metal seal, as set forth herein, to thereby eliminate one main source of tube failure; that is, eventual permeability to water vapor existing in current epoxy sealed designs. For such designs, suitable frit or solder glass must be available which will match the glass-metal combinations selected. Examples of such frit or solder sealing glasses are SG-67 (83 × 10 - 7 /° C) and CV-101 (94 × 10 - 7 /° C), both of which have good chemical stability. SG-67 appears preferable due to low weight loss characteristic in the presence of water vapor (0.4 mg/in 2 at 120° C) compared to CV-101 (11 mg/in 2 at 120° C). These frit or solder sealing glasses are suitable for use with either 0120 (KG-12) or 0080 (R-6) glasses.
Referring now to the FIGS. 3 through 6, the procedure for constructing the plasma tube in the present invention will now be described in detail.
Referring more particularly to FIG. 3, there is shown a preshrunk precision bore capillary tube 50 of the type used generally in the manufacture of such tubes, only made of one of the specified glasses set forth herein. Another short section 52 of similar glass tubing is positioned upon a mold 54 which is then heated and compressed by a die 56 to seal the short section of tubing into a flared flange 14 resembling a cup sealed to the end of capillary tube 50. In this way, the subassembly of capillary 12 is completed.
The outer jacket or envelope 10 of the plasma tube is a length of similar glass, somewhat longer than the ultimate design length of the tube to be formed. Preliminarily, a small depression 60 is formed into the glass tubing by known means and thereby forms a circumferential shoulder therein which will subsequently serve as a cathode assembly stop. The jacket is interior dimension with respect to the outer radius of the flange on the capillary so that there is a slight distance between them.
The anode end plate 16, appropriately selected and treated to match the glasses, is then assembled together with the outer jacket 10 and the capillary in a vertical rotating jig. The jig consists of an upper chuck 62 and spindle 64 having a downwardly projecting tip 66 which precisely locates the free end 68 of the capillary in midposition within the envelope 10. The anode 16 rests on a shoulder 70 of a lower spindle 71 and is raised up within the tube into contact with the flange lower portion of the capillary. Lateral positioning of the lower end of the capillary and of the anode is made by second and third projections 72, 74 which extend upwardly from the lower spindle. The entire unit is then rotated and gradually heated by flame at 76 to the point where the outer tube shrinks slightly, fusing itself into intimate sealing contact with the periphery of both the anode and the flared portion of the capillary resulting in the seal as shown in FIG. 1.
FIG. 5 illustrates the cathode assembly 18. The cathode end disc is fused by spot welding to compression spring clip 28 which electrically contacts the electron emitting element 24 of the cathode which usually comprises a section of aluminum tubing. The other end of the cathode is inserted into the capillary and cathode support member 22 having centrally opening fingers 78 and, radially spaced therefrom, a set of outwardly and axially extending spring clip fingers 80. A getter 82 is spot welded to the support member 22. The cathode assembly is then inserted with the capillary/cathode support member end first into the open end of the partially manufactured plasma tube until the cathode support contacts the previously formed shoulder 60 within the tube. The entire unit is then rejigged, as shown in FIG. 6, the previously formed end 84 of the tubing being held in chuck 86 upwardly and positioned by a spindle 88 having a downwardly projecting tip 90 extending through the aperture 32 in the anode disc. The cathode disc 30 rests on a shoulder 98 formed on the upstanding spindle 94 and located at a predetermined location defining the desired length of the finished plasma tube and also serving to slightly compress spring clip 28. When top and bottom spindles are aligned very accurately, the stem portion above dotted lines 96A is not needed and can be removed. The unit is then flame heated at 99 until the outer envelope shrinks into sealing contact and fuses with the cathode disc. The resulting plasma tube is shown in FIG. 1 after the end mirror members 36, 38 have been applied.
The structure and procedure for assembly of the plasma tube as set forth herein possesses many advantages and overcomes limitations inherent in prior art designs. Each of the end plates, i.e. discs, are easily fabricated from a commonly available alloy, as by stamping and coining the same by well-known operations. When incorporated into the present invention, they provide a fused hard seal to each end of a substantially straight, cylindrical envelope which is also commonly available. The stamped or dished ends provide a mirror seat to which a mirror is sealed either by epoxy cements or by glass frit and suitable firing. Thus, each of the end discs serves several purposes in a single, exceedingly simple structure: the purpose of mirror adjustment; the purpose of sealing the end of the tube in a hard seal; and the purpose of providing electrical contact directly through each end of the tube. In addition, the pinch-off tube can also be made of metal devices which eliminate the usual types of different pinch-off tubulation normally made of glass. It is an obvious advantage in the present structure that the pinch-off tubulation is sealed to the tube by a simple brazing operation which is structurally very mechanical and strong. After the tube has been evacuated and filled satisfactorily, the seal off operation can consist of merely utilizing a pinch-off tool to disconnect the unit from the filling station. This eliminates the rather cumbersome heat sealing and annealing of glass tubulation which had previously been required.
While there has been set forth one preferred form of the invention, it should be understood that other structures should be included within the general understanding of what is taught as within the scope of the present invention. By way of further example to alternatives already presented, there has been shown herein a technique of drop sealing which is reaidly adaptable to certain types of laser glass tube forming equipment. Also, the end discs are shown as sealed by the drop sealing technique by slight contractions and edge envelopment of the outer seal within its own diameter. Many variations will occur to those skilled in the art. For example, the end plates could be butt-sealed in which the disc overlaps the ends of the envelope, either by flame heat, induction heating or baking when utilizing a frit interposed between the end disc and the envelope. In any case, the general procedure calls for direct contact between the end of the glass envelope and the disc, after which heat is applied to the point of flowing of the glass or of the frit. Frits suitable for such purposes can be selected to have a high melting point, more specifically, to have a melting point above or approximately in the range of the softening temperature of the glass itself. In the general selection of materials herein, the discs themselves and the corresponding glasses have been selected so that the metal of which the discs are made has a thermal coefficient of expansion sufficiently close to that of the corresponding glass to be within progressible stress limits for differential expansion when cooled to ambient from the annealing point temperature of the glass to thereby permit formation and retention of a direct glass-to-metal seal between these parts. After filling, pinch-off and preferably the further fine tuning of the plasma tube, as will hereinafter be described, the same as connected by suitable conductors to a power supply as shown diagrammatically in FIG. 1.
While the foregoing structure presents itself as a substantial improvement for the reasons set forth and while it is satisfactory with respect to adjustment of the end mirrors by usual means utilizing the coined spherical recesses in each end disc, it would be desirable to provide for fine tuning of the structure to assure that each unit achieves a maximum potential output. The following has been found to provide an elegant and extraordinarily cheap method of custom tuning each tube to maximum output at exceedingly low cost and effort. The method proceeds by placing the laser tube structure in a jig arrangement in which each end is clamped in place. The middle of the tube is then elastically deformed slightly off axis while the tube is rotated in position to a plurality of angular positions. This can be accomplished by having the entire clamping structure provided with rotatable means or by unclamping and reclamping the plasma tube at successive angular positions with respect to the axis of its length. During this process the power output of the tube is measured and it will readily be found that certain radial direction of bending about its axis results in an improvement in the performance. At this juncture, the amount of bending can be varied to note the maximum power available from the tube which should correspond with tubes of known design and character. This establishes a radial direction in which either the tube itself, as in the testing procedure, or the end plate could be changed, i.e., permanently moved in angular direction, so that the new angular direction, as for example, of the orientation of the mirror surface might be varied permanently a small increment to enhance the power. It is found that the end plates as disclosed herein can be inelastically deformed to tilt the mirror supported thereon in that radial direction by impinging upon the same with a punch to cause a small indentation and resulting deformation in the end plate on that radial direction where improvement has been noted by test. Since this test also establishes the maximum power output available from a given laser, such punch operation can be continued successively until a maximum power output is achieved. In practice, the foregoing has been accomplished with a commonly available spring-loaded center punch, as for example a Starrett No. 18A automatic adjustable stroke center punch.
To those skilled in the art to which this invention pertains, many modifications and adaptations thereof will occur, many of which have been set forth as alternatives herein. Accordingly, the descriptions and examples given herein should be taken as representing the preferred form thereof presently known. However, other adaptations, modifications and substitutions therefor which would be expected of a person skilled in this art should be taken as included within the scope of this invention. | Plasma tube for gas lasers including an elongate cylindrical glass envelope closed at one end with a conductive metal anode disc and at the other with a metal cathode disc, each of which has been intimately fused with the envelope. The envelope carries an internally mounted capillary having a bore for confining a discharge within the tube, the capillary being supported by a flange member connected between the capillary and the envelope. Each disc has a centrally located aperture which is aligned with the capillary bore, each aperture being closed by a suitable reflector for defining an optical cavity. Fine tuning of the cavity is accomplished by incremental deformation of one or both of the discs. | 7 |
Field of the Invention
This invention relates to horn speakers, and more particularly to an exponential horn speaker having improved operating characteristics at low cutoff frequencies.
The Prior Art
Experience has shown that most effective horns are those whose rate of flare increases from the throat to the horn mouth. Various functions, such as hyperbolas, catenaries, and exponentials have been used in constructing such horns. The most common horn is one whose cross sectional area increases exponentially with distance from the horn throat. Several characteristics effect the operation of an exponential horn including the length, mouth size, throat size, flare rate and the cutoff frequency at which the horn is to operate.
Previously developed horn speakers such as those described and claimed in U.S. Pat. No. 2,338,262 to Salmon, entitled "Acoustic Horn", issued Jan. 4, 1944, U.S. Pat. No. 2,537,141 to Klipsch, entitled "Loud Speaker Horn", issued Jan. 9, 1951, U.S. Pat. No. 2,690,231 to Levy et al, entitled "Acoustic Device", issued Sept. 28, 1954, U.S. Pat. No. 3,930,561 to Klayman, entitled "Low Distortion Pyramidal Dispersion Speaker", issued Jan. 6, 1976 and U.S. Pat. No. 3,935,925 to Koiwa et al, entitled "Horn Unit for a Speaker", issued Feb. 3, 1976, all describe various horn configurations. However, such prior art horns have provided unsatisfactory operating characteristics at low cutoff frequencies, particularly below a frequency of 500 Hz.
A need has thus arisen for an exponential horn configuration having improved operating characteristics. Moreover, a need has arisen for an exponential horn speaker capable of operating at relatively low cutoff frequencies, particularly below a frequency of 500 Hz.
SUMMARY OF THE INVENTION
In accordance with the present invention, an exponential horn is provided which overcomes the disadvantages associated with prior art exponential horns. The exponential horn of the present invention achieves significant gain in acoustic output at relatively low cutoff frequencies, particularly below a frequency of 500 Hz.
In accordance with the present invention, an exponential horn for use in a speaker is provided and includes a mouth, a throat and horn wall sections connecting the horn mouth and the horn throat. The horn wall sections define a horn whose cross sectional area progressively increases at a selected rate from a value S o at the horn throat in accordance with the function S(z)=S o e mz . S(z) is the cross sectional area measured at any distance z from the horn throat. The flare constant, m, is expressed as (4πf c )/c, where f c is the cutoff frequency of the horn and is from about 300 Hz to about 500 Hz. The horn mouth is rectangular in shape and has a perimeter substantially equal to one wavelength of the cutoff frequency of the horn. The distance between the horn throat and the horn mouth is from about 10 inches to about 17 inches.
DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and for further objects and advantages thereof, reference is now made to the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of a first embodiment of the exponential horn of the present invention;
FIG. 2 is a top plan view of the exponential horn shown in FIG. 1;
FIG. 3 is a side elevational view of the exponential horn shown in FIG. 1;
FIG. 4 is a front elevational view of the exponential horn shown in FIG. 1;
FIG. 5 is a graph of the frequency response characteristics of the first embodiment of the exponential horn of the present invention shown in FIG. 1;
FIG. 6 is a perspective view of a second embodiment of the exponential horn of the present invention;
FIG. 7 is a top plan view of the exponential horn shown in FIG. 6;
FIG. 8 is a side elevational view of the exponential horn shown in FIG. 6;
FIG. 9 is a front elevational view of the exponential horn shown in FIG. 6; and
FIG. 10 is a graph of the frequency response characteristics of the second embodiment of the exponential horn of the present invention shown in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring simultaneously to FIGS. 1-4, a first embodiment of the exponential horn of the present invention is illustrated and is identified generally by the numeral 20. Exponential horn 20 includes a throat 22 and a mouth 24. Throat 22 and mouth 24 are interconnected by top and bottom wall sections 26 and 28 and side wall sections 30 and 32. Top and bottom wall sections 26 and 28 are inclined upwardly and downwardly, respectively, from the throat 22 to mouth 24, while side walls 30 and 32 are inclined outwardly. Although wall sections 26 and 28 have been referred to as being the top and bottom of exponential horn 20, this is for purposes of convenience in discussion. Alternatively, wall sections 30 and 32 could equally be identified as a top and bottom wall section. The configuration of wall sections 26, 28, 30 and 32 will be subsequently described. It can be seen that the cross sectional area of horn 20 from the throat 22 to the mouth 24 increases at a predetermined rate primarily determined by the elected horn cutoff frequency.
Horn 20 is connected to a conventional driver 34 through any convenient coupling. For best results, the internal diameter of horn throat 22 should be approximately equal to the diameter of the driver 34's sound throat. Horn 20 further includes a flange 36 formed integrally around the mouth 24.
Horn 20 may be constructed from materials well known to those skilled in the art; however, in the preferred embodiment horn 20 is constructed from a metal consisting of substantially an aluminum alloy No. 356 and has a wall thickness of approximately 0.25 inches. The weight of horn 20 is approximately 3.75 pounds.
For purposes of discussion, reference axes have been identified in FIGS. 1-4. A longitudinal axis, identified by the letter "z" is centrally disposed within horn 20 and lies perpendicular to planes which contain throat 22 and mouth 24. A second axis identified by the letter "x" extends perpendicular to the z axis, being horizontally disposed to perpendicularly intersect side wall sections 30 and 32 of the exponential horn 20. A third axis is identified by the letter "y" and is disposed perpendicular to the x and z axes and extends vertically to perpendicularly intersect top and bottom wall sections 26 and 28 of exponential horn 20.
Exponential horn 20 is designed in accordance with the following relation:
S(z)=S.sub.o e.sup.mz (1)
where,
S(z) is the cross sectional area measured at any distance along the z axis from throat 22,
S o is the cross sectional area of throat 22,
m is the flare constant, and
e is the base of a natural logarithm.
The flare constant, m, is given by the following relation:
m=(4πf.sub.c)/c (2)
where
f c is the cutoff frequency, defined as the lowest frequency at which the exponential horn provides a significant gain in acoustic output, and
c is the velocity of sound in air, typically 331.6 meters/second. The derivation of Equations 1 and 2 above and an analysis of the propagation of waves in horns is provided in Elements of Acoustical Engineering by H. F. Olson, copyright 1940, 1947 by D. Van Nostrand Co., Chapter V and Fundamentals of Acoustics by L. E. Kinsler and A. R. Frey, Second Edition, copyright 1950, 1962 by John Wiley & Sons, Inc. at Chapter 10. From these and other sources it is apparent that the horn mouth size, throat size and flare rate all effect the operating characteristics of exponential horns.
In the preferred embodiment, exponential horn 20 is designed to operate at a cutoff frequency, f c , of approximately 483 Hz. Substituting this cutoff frequency into Equation 2 above, yields a flare constant of approximately 0.45 inches -1 . The size of mouth 24 is configured in order to provide a sound-to-air impedance match, and is determined using the desired cutoff frequency of approximately 483 cycles. In order to achieve this impedance match, the peripheral dimensions of mouth 24 are approximately equal to one wavelength of the cutoff frequency as determined using the following relation:
wavelength=c/f.sub.c (3)
where
c is the velocity of sound in air, and
f c is approximately 483 cycles.
Therefore, the wavelength of the cutoff frequency is approximately 27 inches. The dimensions of mouth 24 were therefore selected to be approximately 10 inches along the x axis between side wall sections 30 and 32 and approximately 3.5 inches along the y axis between top and bottom wall sections 26 and 28 of exponential horn 20.
Utilizing the above parameters together with Equations 1 and 2, the cross sectional areas S(z) and any distance z along the z axis measured from throat 22 can be calculated. In addition, the dimensions of the exponential horn 20 along the y and x axes thereof can be selected such that the calculated area at any distance z along the z axis is satisfied. In the preferred embodiment of exponential horn 20, driver 34 has a diameter of 0.707 inches, and the overall length of horn 20 from throat 22 to mouth 24 is approximately 10 inches. Utilizing these additional parameters, the data contained in Table 1 below describes the configuration of exponential horn 20.
It will be apparent from Table 1 that the distances between wall sections 26, 28, 30 and 32 do not increase but remain substantially constant in that portion of horn 20 immediately adjacent to throat 22 to form a transition region.
TABLE 1__________________________________________________________________________ S(z) x yz Cross sectional Distance measured Distance measured Reference ReferenceDistance measured are of horn from z axis to from z axis to top letter used in letter used inalong z axis from at distance z side walls and bottom walls FIG. 2 to indi- FIG. 2 to indi-throat (inches) (square inches) (inches) (inches) cate x distance cate y distance__________________________________________________________________________0 .39 .35 .350.25 .44 .35 .350.50 .49 .35 .35 a a'0.75 .55 .39 .351.0 .62 .43 b b'1.25 .69 .47 .361.50 .77 .52 .37 c c'1.75 .86 .56 .382.0 .96 .60 .40 d d'2.5 1.21 .71 .423.0 1.51 .83 .46 e e'3.5 1.89 .97 .494.0 2.37 1.12 .53 f f'4.5 2.97 1.29 .575.0 3.72 1.49 .62 g g'5.5 4.65 1.71 .686.0 5.83 1.95 .74 h h'6.5 7.29 2.23 .827.0 9.14 2.54 .90 i i'7.5 11.44 2.89 .998.0 14.32 3.23 1.11 j j'8.5 17.93 3.63 1.239.0 22.45 4.04 1.39 k k'9.5 28.11 4.50 1.5610.0 35.2 5.03 1.75 l l'__________________________________________________________________________
FIG. 5 illustrates the frequency response of the exponential horn 20 having the configuration detailed above.
Referring simultaneously to FIGS. 6-9, a second embodiment of the exponential horn of the present invention is illustrated and is identified generally by the numeral 40. Exponential horn 40 includes a throat 42 and a mouth 44. Throat 42 and mouth 44 are interconnected by top and bottom wall sections 46 and 48 and side wall sections 50 and 52. Top and bottom wall sections 46 and 48 are inclined upwardly and downwardly, respectively from the throat 42 to mouth 44, while side walls 50 and 52 are inclined outwardly. Although wall sections 46 and 48 have been referred to as being the top and bottom of exponential horn 40, this is for purposes of convenience in discussion. Alternatively, wall sections 50 and 52 could equally be identified as a top and bottom wall section.
The configuration of wall sections 46, 48, 50 and 52 will be subsequently described. It can be seen that the cross sectional area of horn 40 from the throat 42 to the mouth 44 increases at a predetermined rate primarily determined by the elected horn cutoff frequency.
Horn 40 is connected to a conventional driver 54 through any convenient coupling. For best results, the internal diameter of horn throat 42 should be approximately equal to the diameter of the driver 54 sound throat. Horn 40 further includes a flange 56 formed integrally around the mouth 44.
Horn 40 may be constructed from materials well known to those skilled in the art; however, in the preferred embodiment horn 40 is constructed from a metal consisting of substantially an aluminum alloy No. 356 and has a wall thickness of approximately 0.25 inches. The weight of horn 40 is approximately 8 pounds.
For purposes of discussion, reference axes, x, y and z, have been identified in FIGS. 6-9 corresponding to the reference axes in FIGS. 1-4.
In the preferred embodiment, exponential horn 40 is designed to operate at a cutoff frequency, f c , of approximately 310 Hz. Substituting this cutoff frequency into Equation 2 above, yields a flare constant of approximately 0.28 inches -1 . The size of mouth 44 is configured in order to provide a sound-to-air impedance match, and is determined by the desired cutoff frequency of approximately 310 cycles. The dimensions of mouth 44 were selected to be 12.7 inches along the x axis between side wall sections 50 and 52 and approximately 3.5 inches along the y axis between top and bottom wall sections 46 and 48 of exponential horn 40.
Utilizing the above parameters together with Equations 1 and 2, the cross sectional area S(z) at a distance z along the z axis measured from throat 42 can be calculated. In addition, the dimensions of the exponential horn 40 along the y and x axes thereof can be selected such that the calculated area at any distance along the z axis is satisfied. In the preferred embodiment of exponential horn 40, driver 54 has a diameter of 0.707 inches, and the overall length of horn 40 from throat 42 to mouth 44 is approximately 16.5 inches. Utilizing these additional parameters, the data contained in Table 2 below describes the configuration of exponential horn 40.
It will be apparent from Table 2 that the distance between wall sections 46 and 48 does not increase but remains substantially constant in that portion of horn 40 immediately adjacent to throat 42 to form a transition region.
TABLE 2__________________________________________________________________________ S(z) x yz Cross sectional Distance measured Distance measured Reference ReferenceDistance measured area of horn from z axis to from z axis to top letter used in letter used inalong z axis from at distance z side walls and bottom walls FIG. 7 to indi- FIG. 8 to indi-throat (inches) (square inches) (inches) (inches) cate x distance cate y distance__________________________________________________________________________0 .39 .35 .350.25 .43 .30 .360.5 .45 .32 .35 a a'0.75 .48 .34 .351.0 .52 .37 .35 b b'1.5 .6 .42 .362.0 .70 .48 .36 c c'2.5 .80 .54 .373.0 .93 .61 .38 f d'3.5 1.06 .68 .394.0 1.24 .76 .41 e e'4.5 1.4 .84 .425.0 1.6 .93 .44 f f'5.5 2.00 1.05 .476.0 2.2 1.13 .49 g g'6.5 2.53 1.24 .517.0 2.94 1.36 .54 h h'7.5 3.42 1.5 .578.0 3.84 1.6 .60 i i'8.5 4.5 1.77 .649.0 5.25 1.93 .68 j j'9.5 6.05 2.1 .7210.0 7.0 2.3 .76 k k'10.5 8.04 2.48 .8111.0 9.3 2.70 .86 l l'11.5 10.7 2.92 .9212.0 12.4 3.16 .98 m m'12.5 14.2 3.42 1.0413.0 16.4 3.70 1.11 n n'13.5 18.8 4.01 1.1714.0 21.9 4.35 1.26 o o'14.5 25.3 4.68 1.3515.0 29.3 4.06 1.45 p p'15.5 33.8 5.46 1.5516.0 39 5.9 1.65 q q'16.5 45 6.36 1.77__________________________________________________________________________
FIG. 10 illustrates the frequency response of exponential horn 40 having the configuration detailed above.
Whereas the present invention has been described with respect to specific embodiments thereof, it will be evident to those skilled in the art that numerous modifications and alterations are possible without departing from the spirit and scope of the invention as set forth in the appended claims. | An exponential horn for use in a speaker is provided and includes a horn having a mouth, a throat and horn wall sections connecting the horn mouth and the horn throat. The horn wall sections define a horn whose cross sectional area progressively increases at a selected rate from a value S o at the horn throat substantially in accordance with the function S(z)=S o e mz . S(z) is the cross sectional area measured at any distance z from the horn throat, m is the flare constant defined as 4πf c /c, where f c is the cutoff frequency of the horn and is from about 300 Hz to about 500 Hz. The horn mouth is rectangular in shape and has a perimeter substantially equal to one wavelength of the cutoff frequency of the horn. The distance between the horn throat and the horn mouth is from about 10 inches to about 17 inches. | 6 |
This application is a continuation in part of U.S. patent application Ser. No. 09/253,551 filed on Feb. 22, 1999, which in-turn is a Continuation-in-Part of application Ser. No. 09/236,466 filed Jan. 25, 1999 and priority-based on Japanese patent applications No. 10-13686, No. 10-32471 and No. 10-40213.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a recording medium discharging apparatus and an image forming apparatus provided with the discharging apparatus. In particular, the invention relates to a recording medium discharging apparatus which can be mounted on top of an image forming apparatus such as a printer in order to receive, sort and store recording media on which images have been formed.
2. Description of Related Art
Conventionally known is a recording medium processor apparatus for receiving, sorting and storing or holding recording media such as sheets of paper on which images have been formed by an image forming machine such as a copying machine, a printer and a facsimile machine. A recording medium processor of this type is provided generally as an option for an image forming apparatus, and is sometimes called as “discharging apparatus”, “sorter”, “mail box” etc. The recording medium processor can be mounted detachably on top of the image forming apparatus so that a space over the image forming apparatus can be utilized for space saving.
The recording medium processor has an inlet formed at its bottom, through which recording media can enter it. The processor also has two legs protruding downward from its bottom each on one side. The image forming apparatus has an outlet formed at its top for discharging through it the recording media on which images have been formed. The image forming apparatus also has two slots formed at its top for receiving the respective legs. The processor can be mounted on top of the image forming apparatus with the legs inserted from above into the respective slots, and with the inlet and the outlet connected together.
The image forming apparatus originally includes a tray for storing or holding sheets of paper on which images have been formed by the image forming apparatus. When the recording medium processor is not mounted on the image forming apparatus, all the sheets are discharged to the tray. When the processor is mounted on the image forming apparatus, all or some of the sheets may be conveyed from the image forming apparatus to the processor. The image forming apparatus also includes a pivotable flapper for switching the conveyance of sheets to either the image forming apparatus tray or the processor inlet.
Because the flapper is required only when the recording medium processor is mounted on the image forming apparatus, the provision of the flapper may lead to a wasteful cost increase for the image forming apparatus itself (the first problem).
After dismounting the recording medium processor from the image forming apparatus, it is not possible to place the processor on only the two legs stably on a floor or the like. If the dismounted processor is placed on the legs, it may fall down and consequently be damaged. Therefore, the dismounted processor needs to be laid down on a floor, leaned against a wall or supported by a member. It is thus troublesome to dismount the processor from the image forming apparatus, keep the dismounted processor from damage, and mount the dismounted processor again on the image forming apparatus (the second problem).
The recording medium processor is mounted on the image forming apparatus simply with its legs inserted into the respective slots of the image forming apparatus. If external force is applied to the thus mounted processor, the processor may tilt and consequently result in defective operation. Even greater external force may cause the mounted processor to fall from the image forming apparatus and consequently be damaged (the third problem).
The recording medium processor might be screwed or bolted to the image forming apparatus. This would, however, be troublesome and/or time-consuming, and therefore prevent the processor from being mounted on and dismounted from the image forming apparatus simply or easily.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a recording medium discharging apparatus and the image forming apparatus which can prevent wasteful cost increase for the image forming apparatus.
It is another object of the invention to provide a recording medium discharging apparatus which can be placed stably on a floor or the like even after dismounted from an image forming apparatus, and which is easy to mount on and dismount from the image forming apparatus.
It is still another object of the invention to provide a recording medium discharging apparatus which can be held securely or reliably on an image forming apparatus, and which is simple or easy to mount on and dismount from the image forming apparatus.
In accordance with a first aspect of the invention, an image forming machine is provided, which includes an image forming apparatus for forming images on recording media. The apparatus also includes a recording medium discharging apparatus which can be mounted on top of the image forming apparatus, the discharging apparatus including a plurality of recording medium storers. The apparatus further includes a locking mechanism for locking the discharging apparatus to the image forming apparatus when the discharging apparatus is mounted on the image forming apparatus. The locking mechanism includes a release lever for unlocking the discharging apparatus by being manipulated to shift in the same direction as the discharging apparatus moves away from the image forming apparatus to be dismounted from it.
As stated above, the image forming apparatus includes a locking mechanism for locking the recording medium discharging apparatus to the image forming apparatus when the discharging apparatus is mounted on the image forming apparatus. The locking mechanism prevents the discharging apparatus from falling off the image forming apparatus even if external force is applied to the discharging apparatus mounted on the image forming apparatus. The release lever for unlocking the discharging apparatus makes it easy to dismount the discharging apparatus from the image forming apparatus. This lever can be manipulated to shift in the same direction as the discharging apparatus moves away from the image forming apparatus to be dismounted from it. This makes it possible to drive the lever by utilizing the force applied by a user to dismount the discharging apparatus from the image forming apparatus. It is therefore possible to unlock the discharging apparatus by the operation of dismounting the discharging apparatus from the image forming apparatus.
The recording medium discharging apparatus may include a holding portion which can be held by a user's hand. In particular, by supporting the release lever on the holding portion, it is possible for a user to manipulate the lever while holding the holding portion to dismount the discharging apparatus from the image forming apparatus. The lever may be urged to protrude from the holding portion. In this case, when the user lifts the discharging apparatus from the image forming apparatus, his or her hand draws the lever until the lever retracts into the holding portion against the urging force.
The locking mechanism may include a locking member provided at one of the image forming apparatus and the recording medium discharging apparatus, and shiftable between a locking position and an unlocking position. This mechanism may also include an engaging portion provided at the other of the image forming apparatus and the discharging apparatus. When in the locking position, the locking member is in engagement with the engaging portion. In this case, the release lever moves to shift the locking member from the locking position to the unlocking position.
The recording medium discharging apparatus may include a pair of connectors provided on both sides thereof and extending toward the image forming apparatus. The image forming apparatus may include a pair of engaging portions for receiving the respective connectors. The holding portion may be formed substantially at the midpoint between the connectors. In this case, when a user lifts the discharging apparatus, its weight is balanced with respect to the holding portion. This enables the discharging apparatus to be dismounted safely.
In accordance with a second aspect of the invention, a recording medium discharging apparatus is provided, which can be mounted on top of an image forming apparatus for forming images on recording media. This discharging apparatus includes a plurality of recording medium storers. The discharging apparatus also includes a locking mechanism for locking the discharging apparatus to the image forming apparatus when the discharging apparatus is mounted on the image forming apparatus. The locking mechanism includes a release lever for unlocking the discharging apparatus by being manipulated to shift in the same direction as the discharging apparatus moves away from the image forming apparatus to be dismounted from the image forming apparatus.
This recording medium discharging apparatus can be mounted on an image forming apparatus according to the first aspect, and may further include:
a recording medium introducing section for introducing the recording media with images formed thereon by the image forming apparatus;
a conveying device for conveying the media introduced into the introducing section;
a plurality of discharging devices for discharging to the respective recording medium storers the media conveyed from the conveying device; and
a switching device for guiding selectively to any of the discharging devices the media conveyed by the conveying device.
In accordance with a third aspect of the invention, another recording medium discharging apparatus is provided, which can be mounted on top of an image forming apparatus. This discharging apparatus includes a body including a recording medium storer. The discharging apparatus also includes at least three extensions extending downward from the body for mounting the body with them on the image forming apparatus. The bottoms of the extensions support the discharging apparatus on a horizontal plane when the discharging apparatus is dismounted from the image forming apparatus.
The extensions, with which the discharging apparatus body can be mounted on the image forming apparatus, function as supports for the discharging apparatus. Therefore, when dismounted from the image forming apparatus, the discharging apparatus can stand on the bottoms of the extensions stably on a floor. This prevents the discharging apparatus from being damaged by falling down.
The extensions may be two pairs of extensions, and each pair of them may extend downward from the discharging apparatus body on one side of the discharging apparatus. The four extensions can support the discharging apparatus more stably on a floor. In order to make the discharging apparatus more stable, it is preferable that the center of gravity of the discharging apparatus be positioned between two vertical planes each extending through one of the extensions of one pair and the adjacent extension of the other pair. It is more preferable that the center be positioned substantially at the midpoint between the planes. The image forming apparatus may include four engaging portions for receiving the respective extensions.
The discharging apparatus body may include a recording medium receiver which can be mounted on the image forming apparatus for receiving recording media from the image forming apparatus. The recording medium storer may be mounted on the receiver. The recording medium discharging apparatus may include a pair of connectors for mounting the storer with them on the receiver. The connectors may be fitted to either of the storer and the receiver. Each of the connectors may be positioned between the extensions of one pair.
The recording medium storer may include a plurality of bins. The recording medium discharging apparatus may include a conveying device for conveying the recording media received by the recording medium receiver. The discharging apparatus may also include a plurality of discharging devices for discharging to the respective bins the media conveyed from the conveying device. The discharging apparatus may further include a switching device for guiding selectively to any of the discharging devices the media conveyed by the conveying device.
In accordance with a fourth aspect of the invention, still another recording medium discharging apparatus is provided, which can be mounted on top of an image forming apparatus for forming images on recording media. This forming apparatus includes a discharging portion for discharging the media with images formed thereon. This discharging apparatus includes a plurality of recording medium storers. The discharging apparatus also includes a recording medium introducing section for introducing the media from the image forming apparatus into the discharging apparatus when the discharging apparatus is mounted on the image forming apparatus. The discharging apparatus further includes a switching device for guiding selectively to either of the discharging portion of the image forming apparatus and the introducing section the media with images formed thereon.
As stated above, this recording medium discharging apparatus can be mounted on top of an image forming apparatus. When the discharging apparatus is dismounted from the image forming apparatus, the image forming apparatus discharges recording media through its discharging portion. When the discharging apparatus is mounted on the image forming apparatus, the switching device can guide recording media to the recording medium introducing section of the discharging apparatus. The switching device is fitted to the discharging apparatus, not to the image forming apparatus. It is therefore possible to manufacture the image forming apparatus as an independent image forming apparatus without raising the costs for the image forming apparatus.
The switching device may include a flapper which can pivot between a first guide position where it guides recording media to the discharging portion of the image forming apparatus and a second guide position where it guides recording media to the recording medium introducing section. The switching device may also include a drive for driving the flapper. The recording medium discharging apparatus may include an urging device for urging the flapper toward the second guide position. The discharging apparatus may also include a transmitting device. When the discharging apparatus is mounted on the image forming apparatus, the transmitting device causes no urging force of the urging device to act on the flapper. When the discharging apparatus is dismounted from the image forming apparatus, the transmitting device causes the urging force of the urging device to act on the flapper. The discharging apparatus is thus constructed for the following reason.
The image forming apparatus may have a top opening through which recording media can be conveyed from the image forming apparatus to the recording medium discharging apparatus. The opening should be as small as possible to prevent dust, rubbish, etc. from entering the image forming apparatus. On the other hand, the discharging apparatus needs to be mounted smoothly on the image forming apparatus, with the flapper inserted into the opening without interfering with the opening. For this purpose, when the discharging apparatus is in the process of being mounted on the image forming apparatus, the transmitting device causes the flapper to be urged to the second guide position, where the flapper does not interfere with the opening.
Otherwise, when the recording medium discharging apparatus is mounted on the image forming apparatus, the urging force of the urging device might be applied to the flapper. This could cause the recording media to be conveyed from the image forming apparatus to the discharging apparatus when the discharging apparatus has been mounted.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention is shown in the accompanying drawings, in which:
FIG. 1 is a schematic side view in cross section of a sorter embodying the invention and a laser printer, on which the sorter is mounted;
FIG. 2 is an enlarged schematic side view in cross section of the sorter;
FIG. 3 is a perspective view of the sorter;
FIG. 4 is a schematic side view in cross section of the sorter, showing how the sorter is mounted on the printer;
FIG. 5 is a schematic side view in cross section of the sorter mounted on the printer;
FIG. 6 is a schematic side view in cross section of the sorter placed on a floor;
FIGS. 7 and 8 are side views of the adapter of the sorter, but the left side cover of the casing of the adapter has been removed in order for the locking mechanisms of the sorter to be shown;
FIG. 9 is a partially broken side view of the sorter adapter mounted on the printer, but the right side cover of the adapter casing has been removed so that the selectively switching mechanism of the sorter can be shown;
FIG. 10A is another partially broken side view of the sorter adapter mounted on the printer, but the right side cover of the adapter casing has been removed so that the switching mechanism can be shown;
FIG. 10B is an enlarged view of the selecting flapper and the solenoid of the switching mechanism shown in FIG. 10A;
FIG. 11 is a partially broken side view of the sorter adapter dismounted from the printer, but the right side cover of the adapter casing has been removed in order for the switching mechanism to be shown;
FIG. 12 is a schematic side view in cross section of the sorter, showing how the sorting unit of the sorter is mounted on the adapter;
FIG. 13A is a schematic side view in cross section of the sorter.
FIG. 13B is a schematic side view in cross section of the sorter, showing how two sorting units are mounted;
FIG. 14 is a schematic side view in cross section of the sorter, showing the two sorting units as mounted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a laser printer 2 as an image forming apparatus, which is fitted with a sorter 1 as a recording medium processor according to the present invention. The sorter 1 is mounted removably on top of the printer 2 .
The printer 2 includes a sheet cassette 3 for storing in it sheets of paper as recording media, an image forming unit 4 for forming a toner image, a fixing unit 5 for fixing the toner image transferred onto a sheet of paper, discharge rollers 15 for discharging a sheet of paper with a toner image fixed on it, and a discharge tray 16 for storing or holding a sheet of paper discharged by the rollers 15 . The cassette 3 , the units 4 and 5 , the rollers 15 , and the tray 16 are arranged in order in the direction of sheet flow.
Sheets of paper are stacked in the sheet cassette 3 , which is positioned at the bottom of the printer 2 . The cassette 3 includes a support plate 10 for supporting the stacked sheets. One end of the plate 10 is urged upward by a compression spring 131 . Provided near the urged end of the plate 10 are a feed roller 11 and a frictional separation pad 132 for separating one of the stacked sheets at a time and feeding the separated sheets in order from the cassette 3 to the image forming unit 4 .
The image forming unit 4 and the fixing unit 5 are positioned over or above the sheet cassette 3 in the printer 2 . The image forming unit 4 includes a photosensitive drum 6 , a development processor (not shown) and a charger (not shown). After the drum 6 is charged, the image forming unit 4 forms a toner image by developing with toner an electrostatic latent image formed by scanning for exposure with a laser scanner 133 . Provided under the drum 6 is a transfer roller 7 for transferring onto a sheet of paper the toner image formed on the drum. The fixing unit 5 includes a heating roller 8 and a pressing roller 9 opposite it. A sheet of paper fed from the cassette 3 is fed to the nip between the photosensitive drum 6 and the transfer roller 7 of the image forming unit 4 , where a toner image is transferred onto the sheet. The sheet is moved from the image forming unit 4 to the nip between the heating roller 8 and the pressing roller 9 of the fixing unit 5 , where the transferred toner image is fixed. The sheet is moved from the fixing unit 5 to the discharge rollers 15 .
Formed downstream of the discharge rollers 15 are a first guide passage 18 and a second guide passage 19 for guiding to the discharge tray 16 and the sorter 1 , respectively, the sheets discharged from the rollers 15 .
The discharge tray 16 is positioned downstream of the first guide passage 18 . Sheets of paper discharged from the discharge rollers 15 can be received by and stacked on the tray 16 . The tray 16 is positioned in a recess formed in an upper portion of the printer 2 . The front end of the tray 16 is supported rotatably, and the rear end is urged upward by a compression spring 134 . As sheets of paper are stacked on the tray 16 , their increasing weight turns it gradually downward around its front end. This makes it possible to stack a large number of sheets in aligned condition.
Provided over or above the rear end of the discharge tray 16 is a level sensor 17 for detecting the tray being filled with stacked sheets of paper. The sensor 17 includes a pivotable detecting lever for contact by its own weight with the top one of the sheets stacked on the tray 16 . The sensor 17 detects the filled tray 16 when sheets of paper are stacked up to the position indicated by a phantom line F, and consequently the detecting lever does not pivot downward beyond this position. Provided in the first guide passage 18 are uncurling rollers 20 for uncurling a sheet of paper.
The printer 2 includes a manual feed tray 13 and a feed roller 14 for feeding a sheet of paper placed on this tray. With reference to FIG. 2, the sorter 1 includes an adapter or adapting unit or recording medium receiver 29 as an introducing section for introducing a sheet of paper with an image formed on it by the printer 2 into the sorter 1 . The sorter 1 also includes a sorting unit 28 as a processing unit, which is mounted removably on top of the adapter 29 .
The printer 2 includes a manual feed tray 13 and a feed roller 14 for feeding a sheet of paper placed on this tray. With reference to FIG. 2, the sorter 1 includes an adapter or adapting unit 29 as an introducing section for introducing a sheet of paper with an image formed on it by the printer 2 into the sorter 1 . The sorter 1 also includes a sorting unit 28 as a processing unit, which is mounted removably on top of the adapter 29 .
The adapter 29 has an introducing passage 21 formed through its casing 27 . This passage 21 is for introducing a sheet of paper. The adapter 29 includes in the casing 27 a count lever 31 for detecting a sheet of paper introduced into the passage 21 . The adapter 29 also includes uncurling rollers 30 for uncurling the introduced sheet. The adapter 29 is fitted with a selectively switching mechanism 58 as selectively switching device for guiding a sheet of paper selectively to the discharge tray 16 of the printer 2 or the introducing passage 21 of the sorter 1 .
As shown in FIG. 3, the adapter casing 27 includes a rectangular trunk or body 53 and side portions 51 and 52 . Each of these portions 51 and 52 extends forward from one end of the body 53 . Each of the side portions 51 and 52 generally takes the form of an inverted U in side view. These portions 51 and 52 each include a trunk or body 56 , a front leg 54 and a rear leg 55 . The rear leg 55 extends straight downward from the trunk 56 . The front leg 54 first extends downward and forward from the trunk 56 , and then extends downward. Provided in each of the side portions 51 and 52 is a support plate 57 (FIG. 7 ), which will be described below in detail. This plate 57 includes a front fitting portion 81 and a rear fitting portion 82 as fitting members for fitting on the printer 2 .
As shown in FIG. 2, the introducing passage 21 extends generally vertically through the adapter 29 so that a sheet of paper discharged from the discharge rollers 15 of the printer 2 can be conveyed through this passage to the sorting unit 28 . The nips between the uncurling rollers 30 are positioned in the passage 21 , which extends across the count lever 31 . This lever 31 is positioned upstream of the uncurling rollers 30 .
As described below in detail, the selectively switching mechanism 58 protrudes downward from the adapter 29 , and is inserted into the printer 2 when the adapter 29 is mounted on the printer. The switching mechanism 58 includes a selecting flapper 12 which can pivot between a first guide position as indicated by phantom lines in FIG. 1, where the flapper guides a sheet of paper toward the discharge tray 16 , and a second guide position as indicated by solid lines in FIG. 1, where the flapper guides a sheet of paper toward the introducing passage 21 . In accordance with the guide position of the flapper 12 , a sheet of paper from the discharge rollers 15 is guided selectively to one of the guide passages 18 and 19 . The flapper 12 is controlled by a CPU (not shown) and can be actuated by a solenoid 61 which will be described below.
By fitting the switching mechanism 58 to the adapter 29 , it is possible for the sorter 1 to include all the members and/or parts for determining the direction of sheet discharge. This makes the printer 2 simpler in structure, thereby preventing wasteful cost increase for the printer.
The sorting unit 28 includes a casing 26 , which has an inlet 47 formed at its bottom. A sheet of paper from the introducing passage 21 of the adapter 29 passes through the inlet 47 into the sorting unit 28 . This unit 28 also includes a first bin 41 , a second bin 42 , a third bin 43 , a fourth bin 44 and a fifth bin 45 for storing or holding sheets of paper. The unit 28 includes, in its casing 26 , pairs of discharge rollers 22 as discharging devices for discharging sheets of paper to the respective bins 41 - 45 . The unit 28 also includes pairs of conveying rollers 24 as a conveying device for conveying, to the discharge rollers 22 , sheets of paper passing from the inlet 47 . The unit 28 further includes a first switching flapper 35 , a second switching flapper 36 , a third switching flapper 37 , a fourth switching flapper 38 and a fifth switching flapper 39 as direction switching devices for guiding, to the respective pairs of discharge rollers 22 , sheets of paper passing from the inlet 47 . The casing 26 has an outlet 46 formed at its top, through which a sheet of paper conveyed by the conveying rollers 24 can be discharged upward from the unit 28 . The unit 28 has a conveying passage 32 , which includes a vertical stem or trunk 33 and five branches 34 . The stem 33 is formed vertically through the unit 28 , and extends between the inlet 47 and the outlet 46 . The branches 34 extend from the stem 33 toward the respective pairs of discharge rollers 22 , and open to them. This passage 32 guides sheets of paper from the inlet 47 to the discharge rollers 22 and the outlet 46 .
As shown in FIG. 3, the casing 26 of the sorting unit 28 includes a rectangular trunk or body 50 and side portions 48 and 49 . These portions 48 and 49 each extend forward from one end of the body 50 .
Each of the bins 41 - 45 generally takes the form of a plate to receive and store or hold sheets of paper. Rear end portions of the bins 41 - 45 are supported by the body 50 and the side portions 48 and 49 of the casing 26 . The bins 41 - 45 extend forward and upward, and their front end portions protrude forward beyond the side portions 48 and 49 . The bins 41 - 45 are arranged in vertical alignment.
As shown in FIGS. 1 and 2, the pairs of discharge rollers 22 are positioned over or above the rear ends of the respective bins 41 - 45 . One of the discharge rollers 22 of each pair is driven, and the other roller follows the driven roller.
Each of the switching flappers 35 - 39 is supported pivotably on its horizontal axis positioned over the rear end of the associated branch 34 of the conveying passage 32 . Each of these flappers 35 - 39 can pivot between a third guide position (the position of the third flapper 37 in FIG. 2 ), where it guides a sheet of paper to the associated discharge rollers 22 , and a fourth guide position (the position of the switching flappers other than the third flapper 37 in FIG. 2 ), where it guides a sheet of paper vertically. In accordance with the guide positions of the flappers 35 - 39 , sheets of paper having entered the sorting unit 28 are guided from the vertical stem 33 to arbitrary branches 34 of the passage 32 .
The pairs of conveying rollers 24 for conveying sheets of paper vertically are positioned between the switching flappers 35 - 39 along the vertical trunk 33 of the conveying passage 32 . One of the conveying rollers 24 of each pair is driven, and the other roller follows the driven roller.
The sorting unit 28 includes a motor (not shown) as a motive power source for driving the discharge rollers 22 and the conveying rollers 24 through gear trains (not shown). This motor can also drive the uncurling rollers 30 of the adapter 29 , which includes no motor.
Sheets of paper discharged from the printer 2 can be stored by the bins 41 - 45 of the sorter 1 in the following manner. If the selecting flapper 12 , which has been inserted in the printer 2 , is switched to the second guide position (solid lines in FIG. 1 ), this flapper guides to the introducing passage 21 of the sorter adapter 29 a sheet of paper discharged by the discharge rollers 15 of the printer. The sheet in this passage 21 is uncurled by the uncurling rollers 30 , and then pushes the count lever 31 . Thereafter, the sheet passes through the inlet 47 into the conveying passage 32 of the sorting unit 28 .
Because the uncurling rollers 30 are provided in the adapter 29 , a sheet of paper is uncurled immediately before it is sorted and stored in the sorting unit 28 . The uncurled sheet smoothly enters the sorting unit 28 . This makes it possible to store sheets of paper in an orderly manner in the bins 41 - 45 and restrain sheets of paper from being jammed.
When the count lever 31 is pushed, a detection signal is output, causing the CPU (not shown) to judge that a sheet of paper has entered the sorter 1 . Thus, by providing this lever 31 in the adapter 29 , it is possible to determine whether a sheet of paper has entered the sorter 1 . Therefore, when a sheet of paper is jammed, it is easy to judge whether the sheet is jammed in the printer 2 or the sorter 1 .
A sheet of paper having entered the conveying passage 32 can be conveyed upward in the vertical passage stem 33 by the conveying rollers 24 . When the sheet reaches the switching flapper 35 , 36 , 37 , 38 or 39 in the third guide position, this flapper guides the sheet to the associated discharge rollers 22 . In more detail, the flappers 35 - 39 are controlled by the CPU (not shown) and can each be actuated by a solenoid (not shown). When a sheet of paper should be discharged to one of the bins 41 - 45 , the associated flapper 35 , 36 , 37 , 38 or 39 is turned to the third guide position, with the other switching flappers in the fourth guide position.
As shown in FIG. 2, there may be a case where sheets of paper should be discharged to the third bin 43 . In this case, only the third switching flapper 37 is in the third guide position, while the other switching flappers 35 , 36 , 38 and 39 are in the fourth guide position. After a sheet of paper enters the conveying passage 32 , the sheet is conveyed in the vertical passage stem 33 up to the third flapper 37 in the third guide position by the conveying rollers 24 below this flapper. This flapper 37 turns the sheet to the associated passage branch 34 . The turned sheet is then discharged by the associated discharge rollers 22 to the third bin 43 .
In the case shown in FIG. 2, a sheet of paper from the introducing passage 21 is conveyed without slowing down in the vertical passage stem 33 by the conveying rollers 24 below the third switching flapper 37 until the sheet reaches this flapper. After the sheet is turned by the third flapper 37 to the associated passage branch 34 , the sheet is completely discharged without slowing by the associated discharge rollers 22 to the third bin 43 . Therefore, the sorter 1 can reliably, at high speed, sort and store sheets of paper on which images have been formed by the printer 2 .
With reference to FIGS. 3-6, the sorter 1 can be mounted on and dismounted from the printer 2 as follows. In FIGS. 4-6, locking mechanisms are not shown, which will be described below. As shown in FIGS. 3-6, the front fitting portion 81 of the support plate 57 of each side portion 51 or 52 of the adapter casing 27 protrudes downward from the front leg 54 of the side portion. Likewise, the rear fitting portion 82 of each side portion 51 or 52 protrudes downward from the rear leg 55 of the side portion. The fitting portions 81 and 82 are substantially rectangular, and each include a thin bottom portion. Each front fitting portion 81 has a flat bottom surface for surface contact with another surface. The bottom portion of each rear fitting portion 82 is bifurcated and has round bottom surfaces for surface contact with another surface. The bottom surfaces of the fitting portions 81 and 82 are substantially in horizontal alignment. These portions 81 and 82 surround the center of gravity (dotted line 85 in FIG. 6) of the sorter 1 .
The printer 2 includes a pair of front holding plates 83 and a pair of rear holding plates 84 , all of which are provided in its upper portion. The front holding plates 83 are located for engagement with the respective front fitting portions 81 of the support plates 57 of the sorter 1 . The rear holding plates 84 are located for engagement with the respective rear fitting portions 82 .
With the front fitting portions 81 engaging with and positioned by the respective front holding plates 83 , these portions can be held by these plates. With the rear fitting portions 82 engaging with and positioned by the respective rear holding plates 84 , these portions can be held by these plates. By inserting each of the fitting portions 81 and 82 from above into the associated holding plate 83 or 84 , as shown in FIG. 4, and engaging them, as shown in FIG. 5, it is possible to mount the sorter adapter 29 on the printer 2 . In FIG. 5, each of the fitting portions 81 and 82 is positioned by the associated holding plate 83 or 84 . This makes the sorter 1 mounted stably in an upright or standing position on the printer 2 .
It is possible to dismount the sorter 1 from the printer 2 by lifting the adapter 29 in an upright position to pull each of the fitting portions 81 and 82 out of the associated holding plate 83 or 84 . The sorter 1 may be dismounted from the printer 2 with a user's hands holding the trunks 56 of the side portions 51 and 52 of the adapter casing 27 . Because the trunks 56 are positioned substantially on a vertical plane extending through the center of gravity 85 of the sorter 1 , the sorter can be lifted in balance.
When the sorter 1 is placed on a floor, as shown in FIG. 6, the bottoms of the fitting portions 81 and 82 are substantially in horizontal alignment. These portions 81 and 82 surround the center of gravity 85 of the sorter 1 . It is preferable that, as shown in FIG. 6, the center 85 be positioned substantially at the midpoint between a vertical plane extending through the front fitting portions 81 and a vertical plane extending through the rear fitting portions 82 . It is also preferable that the center 85 be positioned substantially at the midpoint between two vertical planes each extending through the fitting portions 81 and 82 on one side. Therefore, the sorter 1 can rest on the floor stably, without toppling or falling down, substantially in the same upright position as it is mounted on the printer 2 . Therefore, it is not necessary to lay the sorter 1 down on a floor, lean it against a wall and support it with a member, and it is easy to dismount the sorter 1 from the printer 2 , store the dismounted sorter and mount the dismounted sorter again on the printer. Because the sorter 1 can contact with the floor with the bottom surfaces of the fitting portions 81 and 82 , it is possible to well keep the sorter 1 mounted stably on the floor.
The fitting portions 81 and 82 , which are provided as fitting members used when the sorter 1 is mounted on the printer 2 , function as legs when the sorter is dismounted from the printer and placed on a floor. Therefore, there is no need to provide special or extra legs other than the fitting portions 81 and 82 , with which to place the sorter 1 stably on a floor. This simplifies the structure of the sorter 1 and reduces the number of parts of the sorter.
The sorter 1 is mounted in an upright position on the printer 2 . After the sorter 1 is dismounted from the printer 2 , the sorter is placed still in an upright position on a floor. In other words, the sorter 1 is mounted and dismounted substantially in the same position. Therefore, the sorter 1 can be dismounted from the printer 2 by being lifted in an upright position, and then be placed still in the same position on a floor. Likewise, the sorter 1 placed in the upright position on the floor can be lifted still in the same position, and then be mounted still in this position from above on the printer 2 . It is therefore easier to mount the sorter 1 on and dismount it from the printer 2 .
FIGS. 7 and 8 are left side views of the sorter adapter 29 , but the side cover (not shown) of the left side portion 52 of the adapter casing 27 is removed. With reference to FIGS. 7 and 8, the sorter 1 includes two locking mechanisms 101 (only one shown in FIGS. 7 and 8) for keeping it mounted on the printer 2 . These mechanisms 101 are provided in the respective side portions 51 and 52 of the casing 27 .
With reference to FIG. 7, each of the support plates 57 of the sorter adapter 29 includes a trunk or body 59 integrally connecting the tops of the associated fitting portions 81 and 82 . Each of the locking mechanisms 101 is provided on the trunk 59 and a top portion of the rear fitting portion 82 of the associated support plate 57 . Each locking mechanism 10 includes a lever 102 , a pivot or swing member 103 as first engaging portion, a compression spring 104 as an urging device, and a link 105 . The pivot member 103 interlocks or works with the lever 102 . The link 105 links the lever 102 and the pivot member 103 together.
The lever 102 is supported pivotably by the associated support plate 57 in such a manner that it can be positioned partially under the trunk 56 of the associated side portion 51 or 52 of the adapter casing 27 . The lever 102 includes an operating portion 106 for manual operation or manipulation, a horizontal support pin 107 , a spring shoe or seat 108 and a connector 109 . The operating portion 106 , the pin 107 , the shoe 108 and the connector 109 are formed integrally. The pin 107 is supported rotatably on the trunk 59 of the support plate 57 so that the operating portion 106 can pivot up and down around the pin. The pin 107 is positioned at the top of the lever 102 and near the rear end of the lever. The shoe 108 is positioned above and in the rear of the pin 107 , and bears one end of the spring 104 ,the other end of which is fixed to the trunk 59 . The connector 109 extends downward and backward from the pin 107 , and is connected to the pivot member 103 .
Part of the operating portion 106 is positioned under the trunk 56 of the associated side portion 51 or 52 of the adapter casing 27 . Through the operating portions 106 of the side portions 51 and 52 extends a vertical plane on which the center of gravity 85 of the sorter 1 is positioned. The spring 104 downward urges the front end of the associated operating portion 106 , which is positioned opposite the associated spring shoe 108 with respect to the associated support pin 107 .
The pivot member 103 includes a connector 110 as a portion for receiving motive power, a pawl 111 , and a horizontal pivot pin 112 . This pin 112 is supported rotatably on the top of the rear fitting portion 82 of the support plate 57 in such a manner that the pivot member 103 can pivot around this pin. The connector 110 extends upward and forward from the pin 112 toward the trunk 59 of the plate 57 . The pawl 111 extends downward from the pin 112 .
Each of the rear holding plates 84 of the printer 2 includes an engaging portion 113 as a second engaging portion formed at its top. The pivot member 103 can pivot between an engaging position, where its pawl 111 engages with the associated engaging portion 113 , and a disengaging position, where the pawl disengages from the engaging portion 113 . The connectors 110 and 109 of the pivot member 103 and the lever 102 , respectively, are linked together by the link 105 . The engaging portion 113 protrudes toward the pawl 111 so that it can engage with the pawl. When the sorter 1 is mounted on the printer 2 , the engaging portion 113 is positioned in front of the pawl 111 . The pawl 111 includes a slope 114 for sliding on the engaging portion 113 to guide the engagement of the pawl with the engaging portion when the sorter 1 is in the process of being mounted on the printer 2 .
FIG. 7 shows the sorter 1 as mounted on the printer 2 and locked by the locking mechanisms 101 . The spring 104 of each locking mechanism 101 urges the front end of the operating portion 106 of the associated lever 102 downward and the connector 109 of the lever upward. The upward urged connector 109 turns the connector 110 of the associated pivot member 103 upward through the associated link 105 , moving the associated pawl 111 forward to the engaging position, where the pawl engages with the associated engaging portion 113 of the printer 2 .
FIG. 8 shows the sorter 1 as unlocked in the process of being dismounted from the printer 2 . It is possible to unlock the sorter 1 by pushing upward the operating portions 106 of the levers 102 of the locking mechanisms 101 . Specifically, when each operating portion 106 is pushed upward against the urging force of the associated spring 104 , the associated lever connector 109 turns downward. This turns the connector 110 of the associated pivot member 103 downward through the associated link 105 , moving the associated pawl 111 backward to the disengaging position, where the pawl disengages from the associated engaging portion 113 of the printer 2 .
When a user mounts the sorter 1 on the printer 2 , he or she basically holds the trunks 56 of the side portions 51 and 52 of the adapter casing 27 with both his or her hands, as stated above. Therefore, with a user's hands holding and raising the levers 102 of the side portions 51 and 52 , the sorter 1 can be mounted from above on the printer 2 . By thus mounting the sorter 1 with the levers 102 held by a user's hands, it is possible for the levers to be turned upward relative to the support plates 57 naturally by the weight of the sorter. The upward turning of each lever 102 moves the associated pawl 111 to the disengaging position, in which the pawl is kept during the mounting operation. This allows the pawl 111 to be inserted smoothly without contacting with the associated engaging portion 113 of the printer 2 . When the mounting operation ends, the hands are moved out of contact with the levers 102 , causing the urging force of the springs 104 to move the pawls 111 to the engaging position. As a result, as shown in FIG. 7, the pawls 111 engage with the engaging portions 113 .
Consequently, while the sorter 1 is mounted on the printer 2 , the springs 104 keep the pawls 111 in engagement with the engaging portions 113 of the printer 2 , thereby keeping the sorter locked. This fixes the mounted sorter 1 securely to the printer 2 . Even if external force is applied to the mounted sorter 1 , the sorter hardly tilts or falls from the printer 2 . It is therefore possible to hold the sorter 1 reliably on the printer 2 .
Otherwise, the sorter 1 may be mounted on the printer 2 without the levers 102 being held. If the sorter 1 is mounted without the levers 102 being operated, the pawls 111 come into engagement with the engaging portions 113 . Then, the pawls 111 move against the urging force of the springs 104 to the disengaging position, where they disengage from the engaging portions 113 . When the slopes 114 of the pawls 111 disengage from the engaging portions 113 , the pawls return to the engaging position, where they are caused by the springs 104 to engage with the engaging portions 113 . It is therefore possible to lock the sorter 1 with the locking mechanisms 101 even without operating the levers 102 during the mounting operation.
When a user dismounts the sorter 1 from the printer 2 , he or she lifts the sorter with both his or her hands holding the levers 102 . In this situation, because the sorter 1 and the levers 102 are moved in the same direction, naturally the levers are turned upward relative to the sorter by the weight of the sorter. The upward turned levers 102 move the pawls 111 to the disengaging position, where the pawls disengage from the engaging portions 113 . This makes it possible to unlock the sorter 1 and dismount it from the printer 2 at a time by only holding the levers 102 with a user's hands. It is therefore easy to dismount the sorter 1 from and mount it on the printer 2 .
The levers 102 are positioned partially under the trunks 56 of the side portions 51 and 52 of the adapter casing 27 . As stated above, a user holds the trunks 56 with his or her hands when he or she mounts the sorter 1 on and dismounts it from the printer 2 . When a user dismounts the sorter 1 from the printer 2 , he or she holds the levers 102 as well as the trunks 56 . That is to say, it is possible to carry out the holding for removal and the lever operation by holding the same parts. This makes it possible to dismount the sorter 1 more efficiently.
The operating portions 106 of the levers 102 are positioned partially under the respective trunks 56 of the side portions 51 and 52 of the adapter casing 27 . Through the operating portions 106 extends a vertical plane on which the center of gravity 85 of the sorter 1 is positioned. Therefore, when the sorter 1 is lifted with the levers 102 held by a user's hands, it can be held in balance. Therefore, by mounting and dismounting the sorter 1 with the levers 102 held by a user's hands, it is possible to hold the sorter in balance. This enables the sorter 1 to be mounted on and dismounted from the printer 2 stably.
When the connectors 110 of the pivot members 103 turn upward, these members pivot so that their pawls 111 can engage with the engaging portions 113 of the rear holding plates 84 . There may be a case where external force is applied to pull upward the sorter 1 mounted on the printer 2 . This may turn the connectors 110 of the pivot members 103 upward. In this case, the pawls 111 do not disengage from the engaging portions 113 , rather engage more firmly or strongly with them. Therefore, even if external force is applied to the sorter 1 mounted on the printer 2 , the pawls 111 do not disengage accidentally from the engaging portions 113 . This makes it possible to more reliably or securely hold the sorter 1 mounted on the printer 2 .
As stated before, when the sorter 1 is mounted on the printer 2 , the pawls 111 of the pivot members 103 are moved to the engaging position, where they engage with the engaging portions 113 of the printer. This makes it possible to securely hold the sorter 1 mounted on the printer 2 . Therefore, even if external force is applied to the sorter 1 , the sorter hardly tilt or fall from the printer 2 . It is consequently possible to keep the sorter 1 operating in good condition, and prevent or restrain the sorter from being damaged by falling down.
As also stated, when the sorter 1 is in the process of being dismounted from the printer 2 , the sorter is lifted in an upright position with a user's hands holding the levers 102 of the locking mechanisms 101 . This moves the pawls 111 of the pivot members 103 to the disengaging position, where the pawls disengage from the engaging portions 113 of the printer 2 . The disengagement allows the sorter 1 to be dismounted easily from the printer 2 .
Thus, by moving the pawls 111 of the pivot members 103 between the engaging and disengaging positions, it is possible to securely hold the sorter 1 mounted on the printer 2 , while it is easy or simple to mount the sorter on and dismount it from the printer.
FIGS. 9-11 are right side views of the sorter adapter 29 , but the right side cover (not shown) of the right side portion 51 the adapter casing 27 is removed. FIGS. 9 and 10A show the sorter 1 as mounted on the printer 2 . FIG. 10B is an enlarged view of the selecting flapper and the solenoid of the switching mechanism, and parts near them shown in FIG. 10 A. FIG. 11 shows the sorter 1 as dismounted from the printer 2 .
With reference to FIG. 9, the selectively switching mechanism 58 includes the selecting flapper 12 as a switching device, the solenoid 61 , a first tension spring 62 as an urging device and a link 63 as a transmitting device for transmitting urging force. The solenoid 61 can move the flapper 12 between the first and second guide positions. The spring 62 can urge the flapper 12 toward the second guide position. When the sorter 1 is mounted on the printer 2 , the link 63 causes no urging force of the spring 62 to act on the flapper 12 . When the sorter 1 is not mounted on the printer 2 , the link 63 causes the urging force of the spring 62 to act on the flapper 12 .
The selecting flapper 12 includes a horizontal shaft (not shown), a number of flap members 64 and a flapper swinger 66 which are formed integrally. This shaft has an axis 65 , extends through the trunk 53 of the adapter casing 27 longitudinally of it, and is supported rotatably between the side portions 51 and 52 of this casing. The flap members 64 are formed on this shaft at intervals along it, protrude downward from the casing trunk 53 , and can pivot or swing between the first and second guide positions. The swinger 66 is formed on the right end of this shaft and positioned in the right side portion 51 of the casing 27 .
The flapper swinger 66 includes a rear connector 68 , a front engaging portion 69 and a middle connector 70 . The rear connector 68 and the front engaging portion 69 are positioned opposite each other with respect to the shaft axis 65 . The middle connector 70 is positioned above and in front of the axis 65 , and between the rear connector 68 and the engaging portion 69 . The rear connector 68 is connected to one end of a second tension spring 67 , the other end of which is anchored above the swinger 66 . This spring 67 urges the selecting flapper 12 toward the first guide position, but is weaker than the first tension spring 62 .
The solenoid 61 is positioned in the right side portion 51 of the adapter casing 27 , and above and in the rear of the selecting flapper 12 . The middle connector 70 of the flapper swinger 66 is connected to a plunger 71 . If the solenoid 61 is energized or excited, it retracts the plunger 71 .
When the sorter 1 is mounted on the printer 2 , the link 63 is out of engagement with the front engaging portion 69 of the flapper swinger 66 , as described below. In this situation, if the solenoid 61 is not energized, the second tension spring 67 pulls the rear connector 68 of the swinger 66 upward. This turns the selecting flapper 12 around the axis 65 clockwise in FIG. 9, moving this flapper to the first guide position, which is shown in FIG. 9 . If the solenoid 61 is energized, the plunger 71 retracts, pulling the middle connector 70 of the swinger 66 backward. This turns the flapper 12 around the axis 65 counterclockwise in FIG. 9 against the force of the spring 67 , moving the flapper to the second guide position, which is shown in FIGS. 10A and 10B.
The link 63 is positioned in front of the selecting flapper 12 , and includes a body 73 , a first protrusion 74 as a connector, a second protrusion 75 as a second engaging portion, and an engaging portion 76 as a first engaging portion. The link body 73 has a horizontal shaft 72 . The protrusions 74 and 75 protrude from one side of the body 73 , and are spaced angularly from each other. The engaging portion 76 protrudes from the side of the body 73 opposite the protrusions 74 and 75 with respect to the shaft 72 . The body 73 and the parts 72 , 74 , 75 and 76 are formed integrally. When the sorter 1 is mounted on the printer 2 , as shown in FIGS. 9 and 10, the first protrusion 74 is oriented upward and backward, and the second protrusion 75 is oriented downward and backward, while the engaging portion 76 is oriented downward.
The shaft 72 of the link 63 is supported rotatably in the right side portion 51 of the adapter casing. The first protrusion 74 is connected to one end of the first tension spring 62 , the other end of which is anchored above and in front of the link 63 . This spring 62 urges the link 63 to turn around its shaft 72 clockwise in FIG. 11 so that the second protrusion 75 of the link 63 can engage with the front engaging portion 69 of the flapper swinger 66 .
When the sorter 1 is not mounted on the printer 2 , as shown in FIG. 11, the first tension spring 62 pulls the first protrusion 74 of the link 63 forward. This turns the link 63 around the shaft 72 clockwise in FIG. 11 to a second engaging position, where the second protrusion 75 of the link 63 pushes the front engaging portion 69 of the flapper swinger 66 . The pushing turns the selecting flapper 12 around the shaft axis 65 against the force of the second spring 67 counterclockwise in FIG. 11 to the second guide position, where the flap members 64 are oriented substantially downward.
When the sorter 1 is mounted on the printer 2 , as shown in FIGS. 9 and 10, the engaging portion 76 of the link 63 rests on the upper frame 77 of the printer. This turns the link 63 around the shaft 72 against the force of the first tension spring 62 counterclockwise in FIGS. 9 and 10 to a first engaging position, where the second protrusion 75 of the link 63 disengages from the front engaging portion 69 of the flapper swinger 66 . The disengagement allows the second tension spring 67 to urge the selecting flapper 12 toward the first guide position, which is shown in FIG. 9, where the flap members 64 are oriented slightly outward or backward. Only if the solenoid 61 is energized, the flapper 12 is turned against the force of the second spring 67 to the second guide position, which is shown in FIGS. 10A and 10B, where the flap members 64 are oriented downward.
When the sorter 1 is in the process of being mounted on the printer 2 , and when the sorter is dismounted from the printer, the sorter is not mounted on the printer, as shown in FIG. 11 . In this situation, the second protrusion 75 of the link 63 is in engagement with the front engaging portion 69 of the flapper swinger 66 . This allows the urging force of the first tension spring 62 to act through the link 63 on the selecting flapper 12 . This force keeps the flapper 12 in the second guide position, where the flap members 64 are oriented substantially downward. It is therefore possible to mount the sorter 1 on the printer 2 smoothly without the printer interfering with the flap members 64 . This avoids the sorter damage which would be caused if the printer 2 interfered with the flap members 64 . Even when the sorter 1 is dismounted from the printer 2 , no external force is liable to damage the flap members 64 , which are kept in a substantially downward oriented position. It is therefore possible to improve the durability of the sorter 1 .
When the sorter 1 is mounted on the printer 2 , as shown in FIGS. 9 and 10, the second protrusion 75 of the link 63 is out of engagement with the front engaging portion 69 of the flapper swinger 66 . This prevents the urging force of the first tension spring 62 from acting through the link 63 on the selecting flapper 12 . Therefore, the actuation of the solenoid 61 can switch the flapper 12 selectively between the first and second guide positions.
When the sorter 1 is not mounted on the printer 2 , that is to say, when the sorter is in the process of being mounted on the printer, and when the sorter is dismounted from the printer, the first tension spring 62 keeps the selecting flapper 12 in the second guide position, resulting in no electric power consumption. When the sorter 1 is mounted on the printer 2 , the solenoid 61 is energized only if the flapper 12 needs to be in the second guide position for guiding a sheet of paper to the introducing passage 21 of the sorter. Electric power is consumed only for the energization of the solenoid 61 . Thus, no electric power for switching the flapper 12 is consumed, not only when the sorter 1 is dismounted, but also if the sorter is not used even when it is mounted on the printer 2 . This saves electric power.
When the sorter 1 is mounted on the printer 2 , and when the sorter is dismounted from the printer, the link 63 is turned between the engaging positions. This, securely with simple structure, either allows the urging force of the first tension spring 62 to act on the selecting flapper 12 or prevents this force from acting on the flapper. It is therefore possible to simplify the sorter structure and reduce production costs. The sorting unit 28 of the sorter 1 can be fitted to the adapter 29 of the sorter as follows.
With reference to FIGS. 7-12, the support plate 57 in each side portion 51 or 52 of the adapter casing 27 includes a third fitting portion 86 and a fourth fitting portion 87 which are formed integrally. These portions 86 and 87 protrude upward from the top of the casing 27 so as to be fitted into the sorting unit 28 .
With reference to FIGS. 3 and 12, each side portion 48 or 49 of the casing 26 of the sorting unit 28 includes a fitting plate 88 protruding downward from its bottom so as to be fitted into the adapter 29 .
By inserting the third fitting portion 86 and the fourth fitting portion 87 of the support plate 57 into the sorting unit 28 , and inserting the fitting plate 88 of the sorting unit into the adapter 29 , as shown in FIG. 6, it is possible to mount this unit in positioned condition on the adapter.
During such fitting, whether the sorting unit 28 is mounted on the adapter 29 or not, as shown in FIGS. 6 and 12, the adapter is placed stably in an upright position without falling down. It is therefore possible to produce the sorter 1 by placing the adapter 29 on a floor and then fitting the sorting unit 28 to the adapter. This makes it possible to fit the sorting unit 28 well to the adapter 29 during the production, and to thereby improve the productivity.
As shown in FIGS. 13 and 14, one or more additional sorting units may be mounted on the sorting unit 28 . An additional sorting unit 128 is identical with the sorting unit 28 , and these units can be mounted on each other. The additional unit 128 includes five switching flappers 25 corresponding to the respective flappers 35 - 39 of the unit 28 and five bins 23 corresponding to the respective bins 41 - 45 likewise. Each of the units 28 and 128 includes a removable top lid or cover 127 . In FIGS. 13 and 14, the lid (not shown) of the unit 28 is removed, and the additional unit 128 is mounted on the unit 28 .
By inserting the fitting plates 88 of the additional sorting unit 128 into the top of the sorting unit 28 , as shown in FIG. 14, it is possible to mount the additional unit 128 on the unit 28 in stacked condition. The outlet 46 of the unit 28 is connected to the inlet 47 of the additional unit 128 mounted on the unit 28 . The top of the upper sorting unit 128 is covered with its lid 127 .
If all the switching flappers 35 - 39 of the sorting unit 28 mounted on the adapter 29 are in the fourth guide position, a sheet of paper can pass through this unit into the sorting unit 128 mounted on the unit 28 . It is therefore possible to sort and store sheets of paper with the units 28 and 128 combined together.
In particular, if only one of the sorting units 28 and 128 were used always, its top flapper 39 would not need to be pivotable, but might be fixed to the third guide position. Because the top flapper 39 of each unit 28 or 128 can pivot between the first and second guide positions like the other switching flappers 35 - 38 can, the unit can discharge a sheet of paper from its outlet 46 . This makes it possible to combine two or more sorting units.
It is therefore possible to add one or more sorting units depending on the number of bins needed by the users. This makes it possible to easily provide, without specially designing, a sorter 1 having an optimum number of bins for the users. Because the sorting units are stacked upward, the mounting area for the sorter 1 does not change even if a number of sorting units are stacked. This makes it possible to provide in a small mounting space a sorter 1 having a number of bins.
Even if one or more sorting units are added, the center of gravity 85 of the sorter 1 does not change substantially, as shown in FIGS. 6 and 14. Even in this case, the center of gravity 85 is positioned substantially at the midpoint between the vertical plane extending through the front fitting portions 81 and the vertical plane extending through the rear fitting portions 82 . Likewise, the center 85 is positioned substantially at the midpoint between the two vertical planes each extending through the fitting portions 81 and 82 on one side. This makes it possible to place the sorter 1 on a floor stably, without falling down, in substantially the same upright position in which the sorter is mounted on the printer 2 .
It is therefore possible to mount or dismount the additional sorting unit 128 with the adapter 29 placed on a floor. This makes it easier to mount or dismount the unit 128 . More specifically, if the additional unit 128 needed mounting or dismounting with the sorter 1 mounted on the printer 2 , it would be difficult to mount or dismount this unit at the high position over the sorter on the printer. By contrast, it is easier to mount or dismount the unit 128 with the sorter 1 placed on a floor. This greatly improves the working efficiency.
As shown in FIG. 3, the front legs 54 of the side portions 51 and 52 of the adapter casing 27 protrude forward or are positioned in front of the side portions 48 and 49 of the casing 26 of the sorting unit 28 . The front fitting portions 81 of the support plates 57 are positioned in the respective front legs 54 . Therefore, even if one pushes the back of the sorting unit 28 mounted on the adapter 29 , these fitting portions 81 securely support this unit so that the unit 28 may not fall down. This makes it possible to place the adapter 29 stably even with the unit 28 mounted on the adapter.
With reference to FIG. 14, each of the sorting units 28 and 128 is provided with a motor for driving it. Otherwise, only one of the units 28 and 128 might be provided with a motor for driving them. In such a case, the drive systems in the units 28 and 128 might be coupled together by one or more gears. Instead of the sorting unit 28 , the adapter 29 might be provided with a motor.
The recording medium processor (discharging apparatus) according to the invention is not limited to the sorter 1 , the processing unit of which is the sorting unit 28 . The recording medium processor may instead be a stapler, a puncher, a cutter, a laminator or any other processor. In such a case, the processing unit of the processor is a stapling unit, a punching unit, a cutting unit, a laminating unit or any other unit. | A recording medium discharging apparatus which can be mounted on top of the image forming apparatus includes a plurality of recording medium storers and a locking mechanism for locking the discharging apparatus to the image forming apparatus when the discharging apparatus is mounted on the image forming apparatus. The locking mechanism includes a release lever for unlocking the discharging apparatus by being manipulated to shift in the same direction as the discharging apparatus moves away from the image forming apparatus to be dismounted from it. The locking mechanism prevents the discharging apparatus from falling off the image forming apparatus even if external force is applied to the discharging apparatus mounted on the image forming apparatus. The release lever for unlocking the discharging apparatus makes it easy to dismount the discharging apparatus from the image forming apparatus. | 1 |
DESCRIPTION
[0001] The present invention refers to a hub-bearing assembly for a driving wheel of a vehicle particularly a light truck.
[0002] For a better understanding of the state of the art and problems relating thereto, there will be at first described a hub-wheel assembly of conventional design, shown in FIG. 2 of the attached drawings.
[0003] With reference to FIG. 2, a hub 11 of elongated form has a flanged portion 2 with axial bores 3 for bolts 4 for fastening to a brake disc 5 . The hub 11 is accommodated in a stationary tubular housing 6 and rotatably supported by means of a bearing unit, schematically indicated 7 , which is radially interposed between the tubular housing 6 and the cylindrical part of the hub 11 . The bearing unit 7 is of the so-called first generation type, comprising a stationary outer ring, a rotatable inner ring and rolling bodies interposed therebetween. For supporting a brake member 9 , an annular member 8 is welded on the outer surface of the tubular housing 6 . The cylindrical gap 10 defined between the cylindrical part of the hub 11 and the housing 6 is normally filled with lubricant oil.
[0004] An object of the present invention is to provide a hub-bearing assembly that may simplify assembling and maintenance operations.
[0005] An other object of the invention is to make use of a hub and a bearing of smaller size with respect to the above discussed prior art, with a consequent saving of weight and costs.
[0006] These and other objects and advantages, that will be better understood hereinafter, are attained according to the present invention by a hub-bearing assembly as defined in the appended claims.
[0007] There will now be described, by way of a non-limiting example, a preferred embodiment of a hub-bearing assembly according to the present invention, reference being made to the accompanying drawings in which:
[0008] [0008]FIG. 1 is a partially sectioned axial cross-sectional view of an embodiment of a hub-bearing assembly according to the invention; and
[0009] [0009]FIG. 2 is a schematic axial cross-section of a hub-bearing unit of conventional design.
[0010] With reference to FIG. 1, and using the same reference numerals already adopted in FIG. 2 to indicate equal or like parts, numeral 1 indicates an axle shaft for a driving wheel (not shown) of a motor vehicle, particularly a light truck. Naturally, reference to this possible field of use should not be interpreted as in any way limiting the scope of the patent.
[0011] The axle shaft 1 is accommodated in a conventional stationary tubular housing 6 on the outer surface of which there is welded an annular member 8 constituting a flange for supporting a brake bracket 9 .
[0012] An annular hub indicated 11 is formed separately from the axle shaft 1 and coupled for rotation and axially thereto, as will be described in detail in the following. The hub 11 has a central axial tubular portion 12 . At the axially outer end, the hub 11 forms a radial flange portion 2 extending in a radially outer direction with axial bores 3 for bolts 4 for fastening to a wheel and a brake disc (not shown). At the side of the outer flange 2 , the tubular portion 12 has an outer surface of cylindrical shape 14 joining a radial shoulder surface 15 .
[0013] A bearing unit 7 of the so-called second generation is mounted on the cylindrical surface 14 of the hub, at a position outside the tubular housing 6 . The bearing unit includes a pair of radially inner half-races 71 , 72 axially located side-to-side and fast for rotation with the hub, a radially outer stationary race 73 , and a dual set of rolling bodies 74 , 75 (preferably cone rollers) radially interposed between the outer race 73 and the inner half-races 71 , 72 . The outer race 73 forms a radially outwardly extending flange 76 in which there are obtained axial bores 77 for bolts 18 for fastening to the stationary tubular housing 6 . The fastening bolts 18 pass through axially aligned bores 19 and 20 obtained in the brake bracket 9 and the annular flange 8 of the tubular housing 6 , respectively.
[0014] In order to transmit the driving torque from the axle shaft 1 to the hub 11 , these two members are coupled for rotation by an intermediate annular member 30 having a first internal toothing or spline 31 coupled with a corresponding outer toothing or spline 21 formed on the end portion of the axle shaft 1 , and a second inner toothing or spline 32 coupled with a corresponding outer toothing or spline 22 formed on the hub 11 . The outer spline 22 of the hub is formed on the cylindrical surface 12 of the hub at a zone adjacent to the zone where the inner half-race 72 of the bearing is fitted. In the preferred embodiment shown in the drawing, the intermediate annular member 30 has a substantially L-shaped axial cross-section, with a tubular or cylindrical axial portion 33 forming internally the first toothing or spline 31 , and a radial flange portion 34 the central opening of which forms the second internal spline or toothing 32 .
[0015] The hub 11 forms a tubular portion 25 (shown in phantom line in its initial indeformed condition) protruding beyond the flange portion 34 of the intermediate annular member 30 . After the annular member 30 has been fitted onto the tubular portion 25 , the part of this which protrudes beyond the flange portion 34 is cold deformed, preferably by rolling, in a radially outer direction against the flange portion 34 so as to form a plastically deformed edge 26 . The deformed edge 26 axially locks the annular intermediate member 30 on the hub and eliminates axial play between the opposite shoulder 15 of the hub, the inner half-races 71 , 72 and the intermediate annular member 30 . In this way the bearing unit 7 remains axially pre-loaded onto the hub.
[0016] Then, the hub 11 is clamped axially to the axle shaft 1 by means of a central bolt 27 fitted into a central axial bore 16 formed by a radial flange portion 15 extending in a radially inner direction from the tubular portion 12 of the hub. Finally, after having rotated the outer race 73 so as to align the bores 77 with the bores 19 and 20 of the brake bracket 9 and the annular flange 8 , the bolts 18 for fastening to the tubular housing 6 are inserted and tightened.
[0017] At the interface between the bearing outer race 73 and the brake bracket 9 there is fitted an O-ring 28 hermetically sealing the cylindrical gap 10 defined between the axle shaft 1 and the housing 6 and containing lubricant oil.
[0018] While a specific embodiment of the invention has been disclosed, it is to be understood that such disclosure is to be regarded as an exemplary embodiment of the hub-bearing assembly, and that modifications concerning the shape and location of parts, and constructional and functional details may be carried out. | An annular hub ( 11 ) has flange ( 2 ) for connecting to a wheel and an axial cylindrical surface ( 14 ) for mounting a bearing unit ( 7 ). An intermediate annular member ( 30 ) is coupled for rotation to a driving axle shaft ( 1 ) by a first toothed/splined coupling ( 21, 31 ) and to the hub ( 11 ) by a second toothed/splined coupling ( 22, 32 ). | 5 |
This application is a continuation-in-part application of application Ser. No. 08/984,741, filed Dec. 4, 1997.
BACKGROUND
1. Field of the Invention
The present invention relates generally to room air dehumidification, and more particularly, to a liquid desiccant dehumidifier which is portable, energy efficient, and corrosion resistant.
2. Description of the Prior Art
It is known in the art to dehumidify ambient air using liquid desiccant systems. These devices typically utilize hygroscopic liquids such as lithium bromide (LiBr), lithium chloride (LiCl) or calcium chloride (CaCl 2 ) as the desiccant solution. Desiccant units offer advantages over commercial dehumidifiers based on vapor compression technology, specifically in terms of lower energy usage.
In a desiccant system, the desiccant solution absorbs moisture from ambient air exposed to the solution. As the desiccant solution continues to absorb moisture, it becomes dilute and must be regenerated. In the regeneration process, the desiccant solution is heated to evaporate the excess moisture or the desiccant solution is brought into contact with a hot gas to desorb the excess moisture. In some expedients, air regenerators are used to regenerate the desiccant. These arrangements have relatively high operating costs as energy is required to provide a source of heat and to generate a suitable flow of air. In others, boiler-type regenerators are employed. However, boiler embodiments are expensive, as the corrosive nature of liquid desiccant solutions necessitates the use of costly corrosion resistant metals.
A liquid desiccant dehumidfication system in which a liquid desiccant is regenerated with a boiler is described in U.S. Pat. No. 4,939,906 ("the '906 Patent"). The '906 Patent discloses a gas-fired desiccant boiler and a combined desiccant regenerator/interchange heat exchanger, in which the combined regenerator/heat exchanger utilizes steam produced from the boiler to provide heat for partial regeneration. The desiccant boiler has a liquid/vapor separator chamber and thermosyphon recirculation to reduce scale and corrosion of the boiler. Specifically, the overall system is shown in FIG. 1, wherein outdoor air is drawn into the system through an inlet duct 22, and is evaporatively cooled by a water spray 24. The cooled air is directed to a desiccant conditioner 26 to which return air is also directed through a duct 30. In the desiccant conditioner 26, the return air is contacted with a liquid desiccant solution from a sprayer 28. The desiccant liquid is disclosed as lithium calcium chloride.
This dehumidified air is then supplied to the space to be dehumidified, or it can be sensibly cooled through an evaporative cooler 32. The desiccant dehumidifies the air stream, and in the process its moisture-absorbing capability is reduced; this capability is regenerated by passing a portion of the dilute desiccant from the conditioner 26 to a first interchange heat exchanger 44, wherein the temperature of the desiccant is raised. The weakened desiccant is partially concentrated in an air-desiccant regenerator 46, in which heated air from a regeneration air heater 48 contacts the liquid desiccant. This desiccant is pumped through a second interchange heat exchanger 52 and thereafter to a desiccant boiler 56, in which regeneration of the desiccant is completed. The water vapor generated in the desiccant boiler 56 raises the temperature of the air passing through the regeneration air preheater 48. The interchange heat exchangers 44, 52 reduce the temperature of the regenerated desiccant as it returns along the pipe 60 to the conditioner 26.
The boiler 56 is depicted in FIG. 2, and operates on natural circulation, with the density of the fluid (part liquid, part vapor) in the "fired" tubes 70 being less than the density of the liquid in the outer "unfired" tube 74. A porous ceramic burner 80 facilitates combustion to provide a heat source and hot combustion gases are blown through a combustion chamber formed by a housing 88 enclosing the fired tubes 70, and flow across fins 90 of the fired tubes 70. Weak desiccant is pumped into the fired tubes 70 through a manifold 94 which causes water in the desiccant to be vaporized. Accordingly, a density differential is created between the fluid in the fired tubes 70 and the unfired tubes 74 connected between the manifold 94 and a liquid/vapor separator 98 outside the combustion chamber housing 88. This density differential induces a natural flow of desiccant solution up the fired tubes 70 and down the unfired tubes 72. In this manner, the natural circulation of desiccant keeps the inside walls of the fired tubes 70 coated with desiccant to thereby reduce or prevent "hot spots" from forming on the inside of the fired tubes 70 to reduce corrosion and scale build up in the fired tubes 70.
The liquid vapor separator 98 at the top of the boiler 56 separates water vapor from the concentrated liquid desiccant. A portion of the concentrated desiccant is withdrawn from the bottom of the liquid/vapor separator 98 and is returned to the desiccant conditioner 26. Water vapor flowing out of the top of the liquid/vapor separator 98 is subsequently condensed to heat air for use in an earlier regeneration step shown in FIGS. 3 and 4.
The combined regenerator/interchange heat exchanger, depicted in FIGS. 3 and 4, comprises two (2) interchange heat exchangers 44, 52, the desiccant regenerator 46 and the regeneration air heater 48. The combined desiccant regenerator/interchange heat exchanger is identified by the reference numeral 102, and is constructed by alternately stacking two (2) different corrugated plates (see FIG. 4) to define alternating flow channels. Water vapor or steam from the desiccant boiler 56 is introduced near the top of the regenerator/exchanger 102 in alternate channels (plate A). This water vapor is condensed, thereby transferring heat to the air and weak desiccant entering adjacent channels near the top of the regenerator/heat exchanger 102 (plate B). The upper portion of each plate corresponds to the desiccant regenerator 46 and regeneration air heater 48. As the water vapor condenses, the weak desiccant and air mixture is heated and the desiccant is partially regenerated. Warm air and moisture are exhausted by fan 106 to the outdoors. An entrainer 108 is provided to prevent desiccant from escaping the combined regenerator/exchanger 102. The partially regenerated desiccant flows into the middle of a channel plate B, and is further heated by the hot concentrated desiccant removed from the liquid/vapor separator 98. Hot concentrated desiccant from the boiler 56 is introduced at the middle of plate A while the partially regenerated desiccant is removed from the middle of plate B. The partially regenerated desiccant is then pumped to the desiccant boiler 56. Diluted desiccant from the regenerator/heat exchanger 102 is introduced at the bottom of the plate A and is heated by the hot desiccant from the boiler 56. The heated dilute desiccant from the regenerator/heat exchanger 102 is then removed from the center of plate B and pumped to the top of plate B.
The apparatus shown and described in the '906 Patent suffers from several disadvantages. The regeneration process described therein requires the flow of hot air through the system in order to operate. This necessitates the use of additional components such as fans, air preheaters, and liquid/vapor separators, which adds system complexity. Furthermore, the multiple stacked plate interchange heat exchanger configuration is complex and takes up a relatively large amount of space. This arrangement is not suitable for use in a small portable unit.
SUMMARY OF THE INVENTION
In view of the disadvantages in the prior art, it is an object of the present invention to provide a portable liquid desiccant dehumidifier which efficiently regenerates the liquid desiccant using a simple arrangement having a minimum number of components.
It is another object of the present invention to provide a portable liquid desiccant dehumidifier which is energy efficient.
It is still another object of the present invention to provide a portable liquid desiccant dehumidifier which utilizes primarily plastic components to prevent corrosion.
It is yet another object of the present invention to provide a portable liquid desiccant dehumidifier in which steam to desiccant heat recovery takes place in a condenser.
It is still another object of the present invention to provide a portable liquid desiccant dehumidifier in which air vents are provided on the condenser.
It is a further object of the present invention to provide a portable liquid desiccant dehumidifier in which plastic components are used for the interchange heat exchangers.
It is yet another object of the present invention to provide a portable liquid desiccant dehumidifier in which the waste heat radiating from the boiler is utilized in an interchange heat exchanger for desiccant regeneration.
It is another object of the present invention to provide a portable liquid desiccant dehumidifier having a boiler including inner and outer vessels to preheat incoming liquid desiccant entering the outer vessel with hot liquid desiccant from the inner vessel.
It is still another object of the present invention to provide a portable liquid desiccant dehumidifier having a boiler which is primarily elongated in a horizontal orientation to minimize the temperature gradient and consequent concentration differential in the liquid desiccant.
It is yet another object of the present invention to provide a portable liquid desiccant dehumidifier which is lightweight, energy efficient, and inexpensive to manufacture.
It is a further object of the present invention to provide an improved heat exchanger employing at least one polytetrafluoroethyline tube concentrically disposed within a silicone rubber tube.
In accordance with the foregoing objects and additional objects that will become apparent hereinafter, the present invention provides a liquid desiccant dehumidifier, including a liquid desiccant absorber for absorbing moisture contained in ambient air entering the dehumidifier and passing through the desiccant absorber, the desiccant absorber constructed and arranged for receiving concentrated liquid desiccant and dispensing dilute liquid desiccant. A boiler is provided for boiling partially preheated dilute liquid desiccant to evaporate moisture to reconstitute the liquid desiccant into concentrated liquid desiccant. A condenser fluidly communicates with the boiler to receive steam generated by boiling liquid desiccant in the boiler, and with the absorber to receive dilute liquid desiccant from the absorber. The condenser and without directly exposing the dilute liquid desiccant to air is operable to sensibly heat the dilute liquid desiccant therein by recovering the latent heat of condensation as steam delivered from the boiler is condensed, to preheat the dilute liquid desiccant prior to delivery to the boiler to increase operating efficiency.
In a preferred embodiment, the invention provides a liquid desiccant dehumidifier including a liquid desiccant absorber for absorbing moisture contained in ambient air entering the dehumidifier and passing through the desiccant absorber, the desiccant absorber constructed and arranged for receiving concentrated liquid desiccant and dispensing dilute liquid desiccant. A boiler is provided for boiling partially preheated dilute liquid desiccant to evaporate moisture to reconstitute the liquid desiccant into concentrated liquid desiccant. A first heat exchanger fluidly communicates with the desiccant absorber and a second heat exchanger. The first heat exchanger is operable to transfer heat from the concentrated liquid desiccant to the dilute liquid desiccant directed to the first heat exchanger from the desiccant absorber to raise the temperature of the dilute liquid desiccant to a first temperature. A condenser fluidly communicates with the boiler to receive steam generated by boiling the liquid desiccant in the boiler, and with the first heat exchanger to receive partially heated dilute liquid desiccant from the first heat exchanger at the first temperature. The condenser without directly exposing the dilute liquid desiccant to air is operable to sensibly heat the dilute liquid desiccant therein to a second temperature by recovering the latent heat of condensation as steam delivered from the boiler is condensed. The second heat exchanger fluidly communicates with the condenser, the boiler and the first heat exchanger. The second heat exchanger is operable to transfer heat from concentrated liquid desiccant directed to the second heat exchanger from the boiler to the dilute liquid desiccant directed to the second heat exchanger from the condenser at the second temperature to raise the temperature of the dilute liquid desiccant to a third temperature. The dilute liquid desiccant at the third temperature is directed to the boiler and the concentrated liquid desiccant from the second heat exchanger is directed to the first heat exchanger. The second heat exchanger is disposed with respect to the boiler to recover waste heat from the boiler. A pump is provided for pumping concentrated liquid desiccant into the absorber.
In a preferred embodiment, the desiccant absorber includes a top and a bottom and comprises: a plurality of horizontally and vertically disposed interconnected microglass fiber plates; a distributor disposed above the fiber plates at the top of the desiccant absorber for introducing the concentrated desiccant into the desiccant absorber; and a drain pan for collecting the dilute desiccant disposed at the bottom of the desiccant absorber.
In another embodiment, the desiccant absorber includes a plurality of absorber pads disposed side-by-side, the desiccant absorber further comprising a top distributor pan for distributing liquid desiccant to a top side of the pads, and a drain pan for collecting dilute liquid desiccant from a bottom side of the pan. The pads are bonded together at the ends inside the pans. A sealant may be used to fill any gaps between the pads and the pans.
The first heat exchanger comprises at least one tube assembly including an inner tube concentrically disposed within an outer tube to define an annulus therebetween. The dilute liquid desiccant from the desiccant absorber is passed through the inner tube, and the concentrated liquid desiccant is passed through the annulus, or vice-a-versa.
The second heat exchanger comprises at least one tube assembly including an inner tube concentrically disposed within an outer tube to define an annulus therebetween. The tube assembly is coiled around the boiler to recover waste heat passing through the walls of the boiler. The concentrated liquid desiccant from the boiler is passed through the annulus and the partially heated dilute liquid desiccant from the condenser is passed through the inner tube, or vice-a-versa.
In a preferred embodiment, the inner tubes of the heat exchangers are fabricated from Polytetrafluoroethyline and the outer tubes are fabricated from silicone rubber. The inner tubes may be convoluted or corrugated to increase the available heat transfer area.
In a preferred embodiment, the condenser comprises an inner shell disposed within an outer housing defining at least one chamber between the inner shell and the housing. Steam is directed to the inner shell from the boiler through a steam inlet. The housing includes a solution inlet to direct partially heated dilute liquid desiccant from the first heat exchanger into the at least one chamber. A solution outlet communicates with the chamber and directs partially heated dilute desiccant at the second temperature to the second heat exchanger. The inner shell is fabricated from materials including inconel, monel, titanium, Polytetrafluoroethyline, Polytetrafluoroethyline-coated copper, Polytetrafluoroethyline Teflon-coated aluminum, and Polytetrafluoroethyline Teflon-coated stainless steel; and the outer shell is fabricated from materials including Polytetrafluoroethyline, polycarbonate, polyvinylidene fluoride, polypropylene, silicone rubber, polyethylene, and polystyrene.
In an alternative embodiment, the condenser comprises at least one steam inlet communicating steam from the boiler with the at least one chamber and at least one solution inlet communicating partially heated dilute liquid desiccant from the first heat exchanger with the inner shell.
The condenser may incorporate a plurality of fins associated with the inner shell and a plurality of fins associated with the housing. The inner shell may be provided with a plurality of baffles to prevent short circuiting from the steam inlet to the condensate outlet.
In another embodiment, the condenser comprises a housing and a plurality of convoluted tubes. The tubes are supported by opposing support plates, and communicate with a steam inlet to receive steam from the boiler. The housing includes a solution inlet to receive partially heated dilute liquid desiccant from the first heat exchanger, and a solution outlet through which partially heated dilute liquid desiccant is delivered to the second heat exchanger. The tubes are fabricated from Teflon, and the support plates include at least one silicone rubber sheet attached thereto.
In yet another embodiment, the condenser comprises at least one tube assembly including an inner tube defining a first flow passageway and an outer tube, the inner tube being disposed within the outer tube to define an annular second flow passageway therebetween, wherein liquid desiccant is communicated through a first of the flow passageways and steam is communicated through a second of the flow passageways. In an alternative embodiment, the tube assembly is coiled.
In all condenser embodiments, air vents may be provided to vent air from the system. In a preferred embodiment, the air vent may consist of Teflon tape laminated between a polypropylene mesh. Alternatively, conventional float-type air vents may be used.
In a preferred embodiment, the boiler includes an inner vessel and an outer vessel, a heating element disposed in the inner vessel, and a pipe communicating heated liquid desiccant from the inner vessel and disposed within the outer vessel, whereby liquid desiccant is returned to the outer vessel from the condenser and is heated in the outer vessel by hot liquid desiccant passing through the pipe prior to entering the inner vessel.
In an alternative embodiment, the boiler includes an inner vessel and an outer vessel, a heating element disposed in the inner vessel, and an interchange heat exchanger disposed in the outer vessel. The interchange heat exchanger includes an inner tube and an outer tube defining an annulus therebetween, and an inlet disposed to admit desiccant rising to the top of a desiccant puddle in the outer vessel to enable heat transfer with hot desiccant leaving the inner vessel. In this manner, liquid desiccant returned to the outer vessel from the condenser is preheated in the outer vessel and the interchange heat exchanger prior to entering the inner vessel.
In a preferred embodiment, the respective components are disposed with respect to one another to take advantage of gravity feed to communicate the liquid desiccant from the absorber to the boiler via the first and second heat exchangers and the condenser, thereby eliminating the need for multiple pumps in the system.
BRIEF DESCRIPTION OF THE DRAWINGS
In accordance with the above, the present invention will now be described in detail with particular reference to the accompanying drawings.
FIG. 1 is an exploded isometric view of the portable liquid desiccant dehumidifier in accordance with the present invention;
FIG. 1A is a block diagram depicting the general operation of the invention;
FIG. 2 is an exploded isometric view of a desiccant absorber assembly;
FIG. 2A is a detail view of the microglass fiber plates in the absorber;
FIG. 2B is a side elevational view of a desiccant absorber in another embodiment;
FIG. 2C is a detail view of the absorber pads;
FIG. 2D is an isometric view of the desiccant absorber of FIG. 2B;
FIG. 3 is an isometric view of a boiler;
FIG. 4 is a an isometric view of a coiled interchange heat exchanger and the boiler;
FIG. 4A is an isometric view of a boiler in an alternative embodiment;
FIG. 4B is an isometric view of a boiler in another embodiment;
FIG. 5 is an isometric view of a split interchange heat exchanger;
FIG. 5A is a plan view of an inner tube for an interchange heat exchanger having a convoluted profile;
FIG. 5B is a plan view of an inner tube for an interchange heat exchanger having a corrugated profile;
FIG. 6 is an isometric cut-away view of a condenser in a first embodiment;
FIG. 7 is an isometric cut-away view of an inner shell of the condenser shown in FIG. 6;
FIG. 8 is an isometric cut-away view of a condenser in a second embodiment;
FIG. 9 is an isometric cut-away view of a condenser in a third embodiment;
FIG. 9A is an isometric view of a condenser in a fourth embodiment;
FIG. 9B is an isometric view of a condenser is a fifth embodiment;
FIG. 10 is an isometric cut-away view of a frame for housing the respective components of the system; and
FIG. 11 is an isometric cut-away view depicting the frame and some of the components installed therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the several views of the drawings, there is shown a portable liquid desiccant dehumidifier ("PLDD"), generally characterized by the reference numeral 10.
Referring now to FIGS. 1 and 1A, the PLDD 10 includes a liquid desiccant absorber 12 for absorbing moisture contained in ambient air entering dehumidifier 10 and passing through desiccant absorber 12. The desiccant absorber 12 is constructed and arranged for receiving concentrated liquid desiccant at the top of desiccant absorber 12 and dispensing dilute liquid desiccant from the bottom of desiccant absorber 12. The desiccant solution may be any one of several conventional solutions, including aqueous LiBr, LiCl or CaCl 2 , as described above, or any mixture of these solutions. Referring now to FIGS. 2 and 2A, desiccant absorber 12 includes a distributor 14 disposed at the top of desiccant absorber 12 which receives concentrated liquid desiccant and delivers the liquid desiccant through a plurality of "spaghetti" tubes 16 extending radially outward from a central hub 18. The desiccant absorber 12 includes a plurality of horizontally and vertically disposed interconnected microglass fiber plates. The vertical plates are identified by the reference numeral 20, and are supported by horizontal interconnecting fiber plates 22 as shown. The top plate 22 is referred to as a distribution sheet. The concentrated desiccant wicks into the distribution sheet 22 and down the vertical plates 20. The vertical plates 20 contain beads 21 which separate and support contiguous vertical plates 20. Ambient air is drawn into the unit and forced through the microglass fiber plates by a fan 23 (see FIG. 1), where the moisture in the air is removed as the air makes contact with the liquid desiccant. As the desiccant dehumidifies the air stream, the moisture-absorbing capability of the desiccant is reduced and the desiccant must be regenerated. This dilute desiccant is collected in a drain pan 24 disposed at the bottom of desiccant absorber 12. The drain pan 24 includes an intermediate support plate 26 defining at least one drain hole 28 which enables the dilute desiccant to flow into a bottom chamber defined between support plate 26 and a bottom wall 30 of drain pan 24. A drain tube 32 including a one-way or check valve 33 extends from the bottom chamber to direct the dilute desiccant out of absorber 12. The absorber components are disposed within a frame 35 as shown in FIG. 10, which can be fabricated from materials including, but not limited to, polypropylene, polyethylene, polytetrafluoroethyline, which is commercially available under the tradename TEFLON, polyvinylidene fluoride, polycarbonate, PVC or polystyrene. The frame 35 includes a plurality of shelves 37a, 37b, and 37c for supporting the respective components of the unit described below.
The dilute liquid desiccant is regenerated into concentrated desiccant by boiling the liquid desiccant in a boiler 34 at a temperature in the range of from approximately 260° F. to 320° F. An improvement over prior art systems resides in the use of steam to desiccant heat recovery to directly preheat the dilute liquid desiccant. The dilute liquid desiccant is thus passed through a condenser and preheated using the latent heat of condensation of the steam produced by boiling the liquid desiccant. Preferably, a series of interchange heat exchangers are employed to further preheat the dilute liquid desiccant entering the boiler 34 by recovering heat from the concentrated liquid desiccant delivered to absorber 12 from boiler 34 to further increase operating efficiency. These components are described in more detail below.
In an alternative embodiment shown in FIGS. 2B-2D, a plurality of absorber pads 20a are stacked side-by-side. The pads 20a are received in an aperture or slots in a top tray or distributor pan 25 and a bottom tray or drain pan 27. The pads 20a are bonded to each other at the ends thereof with an adhesive "A" (or taped) so that the gaps between the pads 20a and the supporting structure are completely sealed to force the liquid desiccant to wick through the pads 20a. Any other gaps between the pads 20a and the pans 25, 27 may be filled with an RTV silicone sealant or like material. Liquid desiccant is communicated into the distributor pan 25 through an inlet 29. This configuration prevents the liquid desiccant from just flowing over the surface of the pads, and consequently increases absorber efficiency. The trays 25, 27 effectively prevent spillage of liquid desiccant from the absorber 12 in the event of tilting. In addition, the liquid desiccant supplied to the distributor pan 25 forms a thin film on the pan surfaces to reach every distributor pad 20a to improve desiccant distribution.
The boiler 34 is shown in FIG. 3, and is configured in the shape of a tub or vessel having an elongated horizontal dimension. The horizontal elongation provides a uniform temperature gradient, and thus a uniform concentration level of the liquid desiccant solution, as compared to a vertically elongated boiler. The boiler 34 includes side walls 36, a bottom wall 38, a top wall 40, and a peripheral support flange 42 for supporting the other dehumidifier components above the boiler. The boiler 34 is constructed from materials including, but not limited to, polycarbonate, polyvinylidene fluoride, Teflon, fiber glass and the like. A heating element 44 is coiled proximal to the bottom wall 40 as shown, and is connected to a pair of leads 46 in a conventional manner. A thermocouple 48 extends into boiler 34 to monitor the internal temperature. The leads 46 and thermocouple 48 extend through top wall 40. The heating element 44 and thermocouple 48 are operably associated with a controller (not shown) for maintaining boiler 34 at the optimum temperature. A pair of steam outlets 50 extend through top wall 40 to deliver steam generated by boiling the liquid desiccant to a condenser described in more detail below.
Referring now to FIG. 4, a drain tube 51 is coupled to one of the side walls 36 to enable boiler 34 to be emptied as required. A U-fitting 52 is coupled to the upper region of one of the side walls 36 to receive preheated dilute liquid desiccant from the condenser through an inlet port 54, and to dispense concentrated liquid desiccant through an outlet port 56. The U-fitting 52 communicates with a coiled interchange heat exchanger 58, which comprises at least one tube assembly including an inner tube 60 concentrically disposed within an outer tube 62 to define an annulus 64 therebetween. The tube assembly is coiled around boiler 34 to recover the waste heat radiating through side walls 36. This arrangement is exemplary, as the tube assembly could be embedded within the side walls 36, or disposed in contact with top wall 40. The concentrated liquid desiccant from boiler 34 enters the annulus 64 through side wall 36 and is directed to outlet port 56. The partially heated dilute liquid desiccant from the condenser is passed through the inner tube 60 in a direction counter to the concentrated liquid desiccant and enters boiler 34 through side wall 36. Alternatively, the concentrated liquid desiccant is passed through inner tube 60 and the dilute liquid desiccant is passed through annulus 64. In a preferred embodiment, inner tube 60 is fabricated from TEFLON, and outer tube 62 is constructed from silicone rubber. The TEFLON inner tube 60 has relatively high heat conductivity, while the outer silicone rubber tube 62 has a relatively low thermal conductivity, and is a good insulator. These components can withstand relatively high temperatures (˜400° F.), and are not corroded by the desiccant solution. To improve efficiency, inner tube 60 may be convoluted as shown in FIG. 5A or corrugated as shown in FIG. 5B. It is to be understood that the use of this type of TEFLON/silicone rubber tube-in-tube heat exchanger is not limited to a liquid desiccant system. There are many applications in which this arrangement may be employed. The particular operation of the coiled interchange heat exchanger 58 will be described in more detail below.
Referring now to FIG. 4A, there is shown an isometric view of an boiler 34a in an alternative embodiment, having a double-wall configuration including an inner wall 400 and an outer wall 402 which define an inner vessel 404 and an outer vessel 406. A heating element 408 extends into the inner vessel 404 and around the floor as shown. The incoming liquid desiccant from condenser 86 enters the outer vessel 406 of the boiler at inlet 410. Hot liquid desiccant from the inner vessel 404 is communicated into pipe 412 which coils through the outer vessel 406 to effect heat transfer with the incoming liquid desiccant. The desiccant puddle contained in the outer vessel 406 is heated and the hottest portion of the liquid is forced to rise to the top of the vessel 406. It is then fed into the inner vessel 404 via an inlet 414. A thermocouple 416 is disposed in the inner vessel 404 as described above to control the boiler temperature. This arrangement forces any heat radiated or conducted from the inner vessel 404 to flow through the desiccant puddle in the outer vessel 406, thereby reducing thermal losses, and pressure losses attributable to long flow paths. The heating element 408 is disposed below the pump suction or inner vessel boiler outlet 415a so that heating element 408 is always immersed in a pool of liquid desiccant within the inner vessel 404. In this manner, the pump 80 stops drawing liquid desiccant from inner vessel 404 before it is reduced to a level beneath the heating element 408. Hot liquid desiccant leaves the boiler through outlet 415b. This arrangement eliminates the need for a low-level control switch. High level control in the boiler is necessary to provide consistent dehumidification and to prevent excess liquid buildup. A high level control switch can be eliminated by sizing the inner vessel 404 with an internal volume equal to approximately twice the volume of pooled liquid desiccant accumulation. This takes advantage of the inherent desiccant properties to make the system flexible to adapt to varying weather conditions without compromising performance.
Referring now to FIG. 4B, there is shown an isometric view of a boiler 34b in an alternative embodiment, having a double-wall configuration including an inner wall 400b and an outer wall 402b which define an inner vessel 404b and an outer vessel 406b. A heating element 408b extends into the inner vessel 404b and around the floor as shown. The incoming liquid desiccant from condenser 86 enters the outer vessel 406b of the boiler at inlet 410b. An interchange heat exchanger 412a is disposed within the outer vessel 406b. The interchange heat exchanger comprises an inner tube 407a and an outer tube 407b defining an annulus therebetween. The tube arrangement may be similar to that described above with the inner tube being either convoluted or corrugated to improve heat transfer characteristics. An inlet 417 permits liquid desiccant to enter the annulus between inner tube 407a and the outer tube 407b. This liquid desiccant has been preheated by heat transfer between the inner vessel 404a and the outer vessel 406b. The hottest portion of the heated liquid desiccant in the outer vessel is forced to rise to the top of the puddle, and enters the interchange heat exchanger 412a through inlet 417. Hot liquid desiccant from the inner vessel 404b is communicated into the interchange heat exchanger 412a at outlet 415a to effect heat transfer with the incoming liquid desiccant. The preheated liquid desiccant is then fed from the interchange heat exchanger 412a into the inner vessel 404a via an inlet 414a. A thermocouple 416 is disposed in the inner vessel 404a as described above to control the boiler temperature.
Referring now to FIG. 5, there is depicted a split interchange heat exchanger 66, which includes a pair of tube assemblies 68. Each tube assembly 68 comprises an inner tube 70 concentrically disposed within an outer tube 72 to define an annulus 74 therebetween. The dilute liquid desiccant from desiccant absorber 12 is gravity fed to the interchange heat exchanger 66, where it is directed through a manifold 76 and into the inner tubes 70. Concentrated liquid desiccant from boiler 34 is first delivered through coiled interchange heat exchanger 58 and thereafter directed through a U-fitting 78 coupled to the respective outer tubes 72 and into the annuli 74. Alternatively, dilute liquid desiccant is passed through annuli 74 and concentrated liquid desiccant is passed through inner tubes 70. In this manner, heat is transferred from the concentrated liquid desiccant to the dilute liquid desiccant within split interchange heat exchanger 66. The concentrated liquid desiccant is thereafter drawn into a pump 80 (see FIGS. 1 and 1A) through a U-fitting 82 coupled to the respective outer tubes 72. The pump 80 delivers the concentrated liquid desiccant to distributor 14 of absorber 12. The partially heated dilute liquid desiccant flows through a manifold 84 to the condenser. During this stage, the dilute liquid desiccant dispensed from absorber 12 is raised to a first temperature. As discussed above with respect to coiled interchange heat exchanger 58, the inner tubes 70 may be fabricated from TEFLON and the outer tubes 72 may be constructed from silicone rubber. Likewise, the inner tubes may be provided with a convoluted or corrugated profile as shown in FIGS. 5A and 5B, respectively.
The partially heated liquid desiccant at the first temperature is delivered to a condenser 86 from split interchange heat exchanger 66 as shown in FIGS. 1 and 1A. Referring now to FIGS. 6 and 7, there is depicted a first embodiment of condenser 86, which is comprised of an inner shell 88 disposed within an outer housing 90 defining at least one chamber 92 between inner shell 88 and housing 90. The housing 90 includes a plurality of side walls 94, a top wall 96 and a bottom wall 98. A pair of steam tubes 100 communicate with inner shell 88 through top wall 96 to deliver steam from boiler 34. A pair of air vents 102 likewise communicate with chamber 92 through top wall 96 to evacuate excess air therefrom. A condensate tube 104 communicates with inner shell 88 through bottom wall 98 to drain condensate into a condensate pan 106 (see FIG. 1A). An inlet tube 108 communicates with chamber 92 through one of the side walls 94 to deliver partially heated dilute desiccant to condenser 86 from split interchange heat exchanger 66. An outlet tube 110 is similarly disposed to communicate with chamber 92 on an opposite side of condenser 86 to deliver dilute desiccant which is sensibly heated to a second temperature by the latent heat of condensation as the steam condenses in the inner shell 88, to the coiled interchange heat exchanger 58 via the inlet port 54 of U-fitting 52 shown in FIGS. 1 and 4. A fraction of the desiccant flow leaving the condenser may be recirculated to the desiccant absorber 12. This reduces the flow rate to the boiler 34 to lower heat loss and increase energy efficiency. In addition, this maintains a relatively high flow through the absorber 12 and condenser 86 to yield a higher absorption and condensation capacity. To facilitate heat transfer, inner shell 88 is fabricated from materials including inconel, monel, titanium, TEFLON, TEFLON-coated copper, TEFLON-coated aluminum, and TEFLON-coated stainless steel. The housing 90 is fabricated from materials including TEFLON, polycarbonate, polyvinylidene fluoride, polypropylene, silicone rubber, polyethylene, and polystyrene. If a plastic such as TEFLON is used for the housing 90, the wall thickness is made suitably thick to provide the necessary insulating properties.
The condenser 86 may incorporate a plurality of fins 112 located on the exterior of inner shell 88 and a plurality of fins 114 disposed on bottom wall 98 of housing 90. The inner shell 88 may be provided with a plurality of baffles 116 to prevent short circuiting from steam inlets 100 to condensate outlet 104.
Although depicted with the steam being directed into the inner shell 88 and the liquid desiccant being directed into the chamber 92, the opposite arrangement may be employed with the liquid desiccant directed into the inner shell 88 and the steam delivered to the chamber 92. Referring now to FIG. 8, there is shown an alternative embodiment of a condenser 86a, including a housing 90a and inner shell 88a, where the inner shell 88a segregates housing 90a into two compartments 92a, 92b, respectively. A steam inlet tube 100a communicates with compartment 92a, and a steam inlet tube 100b communicates with compartment 92b. Partially heated dilute desiccant solution is delivered to inner shell 88a through solution inlet 108a, and is sensibly heated by the latent heat of condensation as the steam condenses in the respective chambers 92a, 92b. Condensate flows out of chambers 92a, 92b, via condensate outlets 104a, 104b, respectively. Partially heated dilute desiccant at the second temperature flows out of inner shell 88a through solution outlet 110a to coiled interchange heat exchanger 58. Baffles 112a, 112b are provided in chambers 92a, 92b, respectively.
Referring now to FIG. 9, there is shown a third embodiment of a condenser 86b, comprising a housing 90b and a plurality of tubes 118, which may be convoluted or corrugated as described above with regard to the interchange heat exchangers and shown in FIGS. 5A and 5B. The tubes 118 are supported by opposing support plates 120 and communicate with respective steam inlets 100c, 100d through which steam is delivered from boiler 34. The housing 90b includes a liquid desiccant solution inlet 108b to receive dilute liquid desiccant from split interchange heat exchanger 66, and an outlet 110b to deliver partially heated liquid desiccant at the second temperature to the coiled interchange heat exchanger 58. The tubes 118 are fabricated from TEFLON, and the support plates 120 include at least one silicone rubber sheet attached thereto.
Referring now to FIG. 9A, there is shown another embodiment of a condenser 86c, utilizing multiple double-pipe heat exchangers. Each double-pipe heat exchanger comprises an outer straight tube 300 and an inner convoluted tube 302 concentrically disposed within the outer tube. A small annular gap is defined between the outer and inner tubes 300, 302 which forces the fluid to follow a "screw-like" tortuous path through the convolutions at high velocity. This arrangement provides high heat transfer coefficients and condensation capacity. The components can be fabricated from plastics such as polypropylene, TEFLON, PVDF or silicone rubber. Dilute liquid desiccant from split Interchange heat exchanger 66 is directed into a manifold 304. Similarly, steam from boiler 34 flows into a manifold 306 through inlet ports 308. Manifold 304 communicates with the inner convoluted tubes 302. Steam flows through the annuli formed between outer tubes 308 and inner tubes 302, causing the dilute liquid desiccant entering the heat exchangers from manifold 304 to be partially heated to the second temperature. This heated liquid desiccant is delivered to the coiled interchange heat exchanger 58 from exit manifold 310. Condensate is collected in manifold 312, and is then delivered to pan 106. Air vents are utilized to ensure reliable gravity assisted drain flow of the liquid desiccant from the absorber 12 to the boiler 34. In a preferred embodiment, small pieces of TEFLON tape having a micro-pore structure can be used in the vent assembly. The TEFLON material is hydrophobic and has a micro-pore structure which enables the free passage of air while preventing desiccant leakage. The air vent 314 comprises a tube 316 extending upwardly from manifold 310. The tube 316 includes a polypropylene mesh 318 and a piece of TEFLON tape 320 in a laminated structure. Alternatively, conventional float-based air vents, such as air vents manufactured by Honeywell, can be utilized to vent air from the system.
Referring now to FIG. 9B, in another embodiment the condenser 86d comprises multiple coiled double pipe heat exchangers. Each double pipe heat exchanger includes an outer straight tube 300a and inner convoluted tube 302a concentrically disposed within the outer tube 300a. Steam from boiler 34 enters a manifold 306a, from where it is communicated into the annuli formed between outer tubes 300a and inner tubes 302a. Dilute liquid desiccant is delivered to manifold 304a and thence into the inner tubes 302a. Partially heated liquid desiccant exits into manifold 310a, and is delivered to coiled Interchange heat exchanger 58. Condensate flows through outlets 312a to pan 106. This condenser 86d, operates on the same principles and offers the same advantages as the double-pipe condenser 86c described above.
Referring now to FIG. 11, the respective components of the PLDD 10 are shown stacked within frame 35.
During the operating cycle, ambient air is drawn into the unit, through absorber 12 and exhausted to the room by fan 23. The moisture in the air is extracted as the air makes contact with the liquid desiccant wicking across the microglass fiber wick plates 20, 22. Dilute liquid desiccant is gravity fed from drain pan 24 of absorber 12 to manifold 76 of split interchange heat exchanger 66, wherein it is raised to a first temperature through heat transfer from concentrated liquid desiccant flowing through annuli 74. The dilute liquid desiccant at the first temperature is then delivered to the condenser 86, in which the latent heat of condensation as the steam condenses sensibly heats the liquid desiccant to the second temperature. The liquid desiccant at the second temperature is thereafter delivered to the coiled interchange heat exchanger 58 in which it is further heated to a third temperature prior to introduction into boiler 34 for regeneration. The coiled interchange heat exchanger 58 recovers waste heat radiating from the walls 36 of boiler 34. The concentrated liquid desiccant solution produced by boiling the liquid desiccant is drawn through the coiled interchange heat exchanger 58 and split interchange heat exchanger 66, and thereafter delivered to distributor 14 of absorber 12 by pump 80. The stacking of the respective components as shown in FIG. 1 provides for the gravity feed of dilute liquid desiccant from absorber 12 to boiler 34 through the first and second heat exchangers and the condenser, thereby eliminating the need for multiple pumps in the system.
The present invention has been shown and described in what are considered to be the most practical and preferred embodiments. It is anticipated, however, that departures can be made therefrom and that obvious modifications will be implemented by persons skilled in the art. | A liquid desiccant dehumidifier includes a liquid desiccant absorber arranged to receive concentrated liquid desiccant and absorb moisture contained in ambient air passed through the absorber thereby diluting the liquid desiccant. A first heat exchanger is operative to heat dilute liquid desiccant received from the desiccant absorber prior to passage to a boiler that evaporates moisture from the diluted liquid desiccant to create steam and reconstitute the desiccant into a concentrated liquid desiccant. Dilute liquid desiccant from the first heat exchanger first passes to a condenser that receives steam from the boiler and sensibly heats the dilute liquid desiccant to a higher second temperature without direct exposure to steam or air. A second heat exchanger communicates with the condenser, the boiler and the first heat exchanger and is operative to further heat diluted liquid desiccant received from the condenser to a higher third temperature prior to entry into the boiler by recovering waste heat from the boiler. A pump draws concentrated liquid desiccant from the boiler through the heat exchangers and passes it to the absorber. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of PCT/EP02/14392, filed Dec. 17, 2002, which is incorporated herein by reference in its entirety, and also claims the benefit of German Priority Application No. 101 62 842.0, filed Dec. 20, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates to cosmetic and dermatological light-protective preparations, in particular it relates to cosmetic and dermatological formulations with increased UV-A protection performance.
BACKGROUND OF THE INVENTION
[0003] The harmful effect of the ultraviolet part of solar radiation on the skin is generally known. Depending on their particular wavelength, the rays have different effects on the skin as an organ:
[0004] The so-called UV-C radiation with a wavelength between 100 and 280 nm is absorbed by the ozone layer in the Earth's atmosphere and accordingly is not found in the solar spectrum. It is therefore of no physiological importance during sunbathing.
[0005] The so-called UV-B region is between 290 nm and 320 nm. UV-B rays are essentially responsible for the long-lasting tanning of the skin, but can at the same time cause an erythema, simple sunburn or even burns of greater or lesser severity. Chronic photodamage, photodermatoses and Herpes solaris can also be caused by UV-B radiation.
[0006] It has for a long time been incorrectly assumed that long-wave UV-A radiation with a wavelength between 320 nm and 400 nm only has a negligible biological effect and that, correspondingly, the UV-B rays are responsible for most photodamage to the human skin. However, in the meantime, numerous studies have studied that UV-A radiation is much more hazardous than UV-B radiation with regard to the triggering of photodynamic, specifically phototoxic reactions and chronic changes in the skin. The harmful influence of UV-B radiation can also be further intensified by UV-A radiation.
[0007] Thus, it has, inter alia, been found that even UV-A radiation suffices under very normal everyday conditions to harm, within a short time, the collagen and elastin fibers which are of essential importance for the structure and strength of the skin. The consequences are chronic photo-induced changes in the skin—the skin “ages” prematurely. The clinical appearance of skin aged by light includes, for example, wrinkles and lines, and also an irregular, furrowed relief. In addition, the parts affected by photo-induced skin aging have irregular pigmentation. The formation of brown spots, keratoses and even carcinomas or malignant melanomas is also possible. Skin aged prematurely by everyday UV exposure is, moreover, characterized by lower activity of the Langerhans cells and slight, chronic inflammation.
[0008] Approximately 90% of the ultraviolet radiation which reaches the Earth consists of UV-A rays. While UV-B radiation varies widely depending on numerous factors (e.g. time of year and time of day or degree of latitude), UV-A radiation remains relatively constant day to day irrespective of the time of year and time of day or geographical factors. At the same time, the majority of UV-A radiation penetrates into the living epidermis, while approximately 70% of UV-B rays are retained by the horny layer.
[0009] The relatively recent findings concerning the effect of UV-A rays on the skin have led to increased attention now being devoted to protective measures for this ray range. In practice, no sunscreen product is complete any more without an effective UV-A filter effect, and pure UV-B filter preparations are rare.
[0010] When applying a sunscreen to the skin, the ultraviolet rays can be weakened through two effects: firstly, by reflection and scattering of the rays at the surface of pulverulent solids (physical light-protective) and, secondly, by absorption on chemical substances (chemical light-protective). Depending on which wavelength region is absorbed, a distinction is made between UV-B filters (absorption range 280 to 320 nm), UV-A filters (absorption range 320 to 400 nm) and broadband filters (absorption range 290 to about 380 nm).
[0011] To protect against UV-B radiation, numerous compounds are known, the absorption maximum of which should be around 308 nm as far as possible since this is the highest erythema effectiveness of solar radiation. Typical UV-B filters are, for example, derivatives of 3-benzylidenecamphor, of 4-aminobenzoic acid, of cinnamic acid, of salicylic acid, of benzophenone, and also of 2-phenylbenzimidazole.
[0012] Some compounds are also known for protecting against UV-A radiation, such as, in particular, dibenzoylmethane derivatives. However, dibenzoylmethane derivatives are generally not photostable, as a result of which cosmetic or dermatological preparations with a content of this substance should also comprise certain UV stabilizers. Further known UV-A filter substances are certain water-soluble, sulfonated UV filter substances, such as, for example, phenylene-1,4-bis(2-benzimidazyl)-3,3′-5,5′-tetrasulfonic acid and its salts.
[0013] Besides the pure UV-A or UV-B filters, there are substances which cover both regions. This group of broadband filters includes, for example, asymmetrically substituted s-triazine compounds, such as, for example, 2,4-bis{[4-(2-ethylhexyloxy)-2-hydroxy]phenyl}-6-(4-methoxyphenyl)-1,3,5-triazine (INCI: BisEthylhexyloxyphenol Methoxyphenyl Triazine), certain benzophenones, such as, for example, 2-hydroxy-4-methoxybenzophenone (INCI: Benzophenone 3) or 2,2′-methylenebis(6-(2H-benzotriazole-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol) (INCI: Methylene Bis-Benzotriazolyl Tetramethylenebutylphenol).
[0014] In general, the light absorption behavior of light-protective filter substances is very well known and documented, especially as there are positive lists for the use of such substances in most industrialized countries, which impose very strict standards on the documentation. Since, in order to characterize a filter substance, not only is the position of the absorption maximum important, but primarily the absorption range, absorption spectra are recorded for each substance. However, the absorbance values can at best be a guide for the concentration of the substances in the finished formulations since interactions with ingredients of the skin or of the surface of the skin itself may give rise to imponderables. In addition, it is usually difficult to estimate beforehand how uniformly and thickly the filter substance is distributed in and on the horny layer of the skin.
[0015] To test the UV-A protection performance, use is usually made of the IPD method (IPD≡immediate pigment darkening). Similarly to the determination of the sun protection factor, this method gives a value which indicates how much longer the skin protected with the light-protective composition can be irradiated with UV-A radiation until the pigmentation which occurs is the same as for the unprotected skin.
[0016] The use concentration of known light-protective filter substances present in the form of a solid, which exhibit a high filter effect in the UV-A region is, however, often limited—especially in combination with other substances to be dissolved. This therefore gives rise to certain technical difficulties relating to formulation in achieving relatively high sun protection factors or UV-A protection performance.
[0017] Since light-protective filter substances are generally expensive and since some light-protective filter substances are also difficult to incorporate into cosmetic or dermatological preparations in relatively high concentrations, it was an object of the invention to arrive, in a simple and cost-effective manner, at preparations which, despite having unusually low concentrations of conventional UV-A light-protective filter substances, nevertheless achieve an acceptable or even high UV-A protection performance.
SUMMARY OF THE INVENTION
[0018] It was surprising and could not have been foreseen by the person skilled in the art that light-protective cosmetic or dermatological preparations, characterized in that they comprise
[0019] (a) at least one benzotriazole derivative and
[0020] (b) at least one benzoxazole derivative,
[heading-0021] would overcome the disadvantages of the prior art.
[0022] The preparations according to the invention are entirely satisfactory preparations in every respect, which are not restricted to a limited choice of raw materials. Accordingly, they are particularly suitable as bases for preparations with diverse application purposes. The preparations according to the invention exhibit very good sensory and cosmetic properties, such as, for example, extensibility on the skin or the ability to be absorbed into the skin, and are further characterized by very good light-protective effectiveness, an exceptionally high UV-A protection performance, and by excellent skin compatibility coupled with excellent skincare data.
[0023] The invention therefore also provides light-protective cosmetic or dermatological preparations, characterized in that they comprise synergistic substance combinations of
[0024] (a) at least one benzotriazole and
[0025] (b) at least one benzoxazole derivative,
[heading-0026] where the UV protection performance, in particular the UV-A protection performance, of these preparations is increased supraproportionally.
[0027] Surprisingly, the substance combinations according to the invention act synergistically, i.e. superadditively relative to the individual components. They are photostable without further additives and exhibit a surprisingly high protective performance in the UV-A region.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] For the purposes of the present invention, advantageous benzoxazole derivatives are characterized by the following structural formula,
in which R 1 , R 2 and R 3 , independently of one another, are chosen from the group of branched or unbranched, saturated or unsaturated alkyl radicals having 1 to 10 carbon atoms. It is particularly advantageous according to the invention to choose the radicals R 1 and R 2 to be the same, in particular from the group of branched alkyl radicals having 3 to 5 carbon atoms. It is also particularly advantageous for the purposes of the present invention if R 3 is an unbranched or branched alkyl radical having 8 carbon atoms, in particular the 2-ethylhexyl radical.
[0030] A benzoxazole derivative which is particularly preferred according to the invention is 2,4-bis[5-1(dimethylpropyl)benzoxazole-2-yl-(4-phenyl)imino]-6-(2-ethylhexyl)imino-1,3,5-triazine with the CAS No. 288254-16-0, which is characterized by the structural formula
and is available from 3V Sigma under the trade name Uvasorb® k2A.
[0032] The benzoxazole derivative or derivatives are advantageously in dissolved form in the cosmetic preparations according to the invention. It may in some instances, however, also be advantageous when the benzoxazole derivative or derivatives are present in pigmentary, i.e. undissolved form—for example in particle sizes of from 10 nm to 300 nm.
[0033] The total amount of one or more benzoxazole derivatives in the finished cosmetic or dermatological preparations is advantageously chosen from the range from 0.01% by weight to 20% by weight, preferably from 0.1 to 10% by weight, in each case based on the total weight of the preparations.
[0034] Benzotriazoles are characterized by the following structural formula:
in which
R 1 and R 2 , independently of one another, may be linear or branched, saturated or unsaturated, substituted (e.g. substituted by a phenyl radical) or unsubstituted alkyl radicals having 1 to 18 carbon atoms or polymer radicals which themselves do not absorb UV rays (such as, for example, silicone radicals, acrylate radicals and the like), and R 3 is chosen from the group H or alkyl radical having 1 to 18 carbon atoms.
[0038] For the purposes of the present invention, an advantageous benzotriazole is 2,2′-methylenebis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol), a broadband filter which is characterized by the chemical structural formula
and is available under the trade name Tinosorb® M from CIBA-Chemikalien GmbH.
[0040] For the purposes of the present invention, an advantageous benzotriazole is also 2-(2H-benzotriazol-2-yl)-4-methyl-6-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propyl]phenol (CAS No.: 155633-54-8) with the INCI name Drometrizole Trisiloxane, which is characterized by the chemical structural formula
[0041] Further advantageous benzotriazoles for the purposes of the present invention are [2,4′-dihydroxy-3-(2H-benzotriazol-2-yl)-5-(1,1,3,3-tetramethylbutyl)-2′-n-octoxy-5′-benzoyl]diphenylmethane, 2,2′-methylenebis[6-(2H-benzotriazol-2-yl)-4-(methyl)-phenol], 2,2′-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2-(2′-hydroxy-5′-octylphenyl)benzotriazole (CAS No.: 003147-75-9), 2-(2′-hydroxy-3′,5′-di-t-amylphenyl)benzotriazole (CAS No.: 025973-55-1) and 2-(2′-hydroxy-5′-methylphenyl)benzotriazole.
[0042] The total amount of one or more benzotriazoles in the finished cosmetic or dermatological preparations is advantageously chosen from the range 0.01% by weight to 20% by weight, preferably from 0.1 to 10% by weight, in each case based on the total weight of the preparations.
[0043] It is particularly advantageous to choose the weight ratios of the benzoxazole derivative or derivatives to the benzotriazole or the benzotriazoles as 30:1 to 1:30, preferably as 10:1 to 1:10, particularly preferably as 5:1 to 1:5.
[0044] Besides comprising one or more oil phases, the preparations for the purposes of the present invention may preferably additionally comprise one or more water phases and be present, for example, in the form of W/O, O/W W/O/W or O/W/O emulsions. Such formulations can preferably also be microemulsions, sticks, mousses, solids emulsions (i.e. emulsions which are stabilized by solids, e.g. Pickering emulsions), sprayable emulsions or hydrodispersions. Furthermore, the preparations may advantageously also be oil-free or aqueous/alcoholic solutions.
[heading-0045] Sprayable Emulsions, in Particular Microemulsions
[0046] For the purposes of the present invention, sprayable O/W emulsions, in particular O/W microemulsions, are particularly advantageous.
[0047] The droplet diameters of the customary “simple”, i.e. non-multiple, emulsions are in the range from about 1 μm to about 50 μm. Such “macroemulsions” are, without further coloring additives, multi-white in color and opaque. Finer “macroemulsions”, the droplet diameters of which are in the range from about 0.5 μm to about 1 μm, are, again without coloring additives, bluish-white in color and opaque. Such “macroemulsions” usually have a high viscosity.
[0048] The droplet diameter of microemulsions for the purposes of the present invention, by contrast, is in the range from about 50 to about 500 nm. Such microemulsions are bluish-white in color to translucent and in most cases of low viscosity. The viscosity of many microemulsions of the O/W type is comparable with that of water.
[0049] An advantage of microemulsions is that active ingredients can be present in an essentially more finely disperse form in the disperse phase than in the disperse phase of “macroemulsions”. A further advantage is that, due to their low viscosity, they are sprayable. If microemulsions are used as cosmetics, corresponding products are characterized by high cosmetic elegance.
[0050] Advantageous according to the invention are, in particular, O/W microemulsions which are obtainable using the so-called phase-inversion temperature technology and comprise at least one emulsifier (emulsifier A), which is chosen from the group of emulsifiers with the following properties:
their lipophilicity is dependent on the temperature, such that by increasing the temperature the lipophilicity increases, and by reducing the temperature the lipophilicity of the emulsifier decreases.
[0052] Advantageous emulsifiers A are, for example, polyethoxylated fatty acids (PEG-100 stearate, PEG-20 stearate, PEG-150 laurath, PEG-8 distearate and the like), polyethoxylated fatty alcohols (cetearath-12, cetearath-20, isoceteth-20, beheneth-20, laureth-9 etc.), or alkyl polyglycosides (cetearyl glycoside, stearyl glycoside, palmityl glycoside etc.).
[0053] If the phase inversion is triggered essentially by varying the temperature, O/W emulsions, in particular O/W microemulsions, are obtainable where the size of the oil droplets is determined essentially by the concentration of the emulsifier or the emulsifiers used, in such a way that a higher emulsifier concentration results in relatively small droplets, and a lower emulsifier concentration results in relatively large droplets. The droplet sizes are usually between 20 and 500 nm.
[0054] For the purposes of the present invention, it is in some instances advantageous to use further W/O or O/W emulsifiers which do not fall under the definition of emulsifer A, for example in order to increase the water resistance of the preparations according to the invention. For example, alkylmethicone copolyols or alkyldimethicone copolyols (in particular cetyl dimethicone copolyol, lauryl methicone copolyol), W/O emulsifiers (such as, for example, sorbitan stearate, glyceryl stearate, glycerol stearate, sorbitan oleate, lecithin, glyceryl isostearate, polyglyceryl-3 oleate, polyglyceryl-3 diisostearate, PEG-7 hydrogenated castor oil, polyglyceryl-4 isostearate, acrylate/C 10-30 -alkyl acrylate crosspolymer, sorbitan isostearate, poloxamer 101, polyglyceryl-2 dipolyhydroxy-stearate, polyglyceryl-3 diisostearate, polyglyceryl-4 dipolyhydroxystearate, PEG-30 dipolyhydroxystearate, diisostearoyl polyglyceryl-3 diisostearate, glycol distearate, polyglyceryl-3 dipolyhydroxystearate) or fatty acid esters of sulfuric acid or phosphoric acid (cetyl phosphate, trilaureth-4 phosphate, trioleth-8 phosphate, stearyl phosphate, cetearyl sulfate etc.) can be used.
[0055] Further advantageous sprayable O/W emulsions for the purposes of the present invention are low-viscosity cosmetic or dermatological hydrodispersions which comprise at least one oil phase and at least one water phase, where the preparation is stabilized by at least one gel former and does not necessarily have to comprise emulsifiers, but may comprise one or more emulsifiers.
[0056] Advantageous gel formers for such preparations are, for example, copolymers of C 10-30 -alkyl acrylates and one or more monomers of acrylic acid, of methacrylic acid or esters thereof. The INCI name for such compounds is “Acrylates/C10-30 Alkyl Acrylate Crosspolymer”. The Pemulen® grades TR1, TR2 and TRZ from Goodrich (Noveon) are particularly advantageous.
[0057] Carbopols are also advantageous gel formers for such preparations. Carbopols are polymers of acrylic acid, in particular also acrylate-alkyl acrylate copolymers. Advantageous carbopols are, for example, the grades 907, 910, 934, 940, 941, 951, 954, 980, 981, 1342, 1382, 2984 and 5984, likewise the ETD grades 2020, 2050 and Carbopol Ultrez 10. Further advantageous gel formers for such preparations are xanthan gum, cellulose derivatives and carob seed flour.
[0058] Possible (optional) emulsifiers which may be used are ethoxylated fatty alcohols or ethoxylated fatty acids (in particular PEG-100 stearate, ceteareth-20) and other nonionic surface-active substances.
[0059] The very low-viscosity to sprayable emulsions may also advantageously be W/O emulsions or water-in-silicone oil (W/S) emulsions. W/O or W/S emulsions which comprise
at least one silicone emulsifier (W/S) with a HLB value of ≦8 or at least one W/O emulsifier with a HLB value of <7 and at least one O/W emulsifier with a HLB value of >10 are particularly advantageous.
[0062] Such preparations further comprise at least 20% by weight of lipids, where the lipid phase can also advantageously comprise silicone oils, or even consist entirely of such oils.
[0063] The silicone emulsifier or emulsifiers can advantageously be chosen from the group of alkyl methicone copolyols and alkyldimethicone copolyols (e.g. dimethicone copolyols which are sold by Goldschmidt AG under the trade names Abil® B 8842, Abil® B 8843, Abil® B8847, Abil® B 8851, Abil® B 8852, Abil® B 8863, Abil® B 8873 and Abil® B 88183, cetyl dimethicone copolyol [Goldschmidt AG/Abil® EM 90], cyclomethicone dimethicone copolyol [Goldschmidt AG/Abil® EM 97], lauryl methicone copolyol [Dow Corning Ltd./Dow Corning® 5200 Formulation Aid], octyl dimethicone ethoxyglucoside [Wacker].
[0064] The W/O emulsifier or emulsifiers with a HLB value of <7 can advantageously be chosen from the following group: sorbitan stearate, sorbitan oleate, lecithin, glyceryl lanolate, lanolin, hydrogenated castor oil, glyceryl isostearate, polyglyceryl-3 oleate, pentaerythrityl isostearate, methylglucose dioleate, methylglucose dioleate in a mixture with hydroxystearate and beeswax, PEG-7 hydrogenated castor oil, polyglyceryl-4 isostearate, hexyl laurate, acrylate/C 10-30 -alkyl acrylate crosspolymer, sorbitan isostearate, poloxamer 101, polyglyceryl-2 dipolyhydroxystearate, polyglyceryl-3 diisostearate, PEG-30 dipolyhydroxystearate, diisostearoyl polyglyceryl-3 diisostearate, polyglyceryl-3 dipolyhydroxystearate, polyglyceryl-4 dipolyhydroxystearate, polyglyceryl-3 dioleate.
[0065] The O/W emulsifier or emulsifiers with a HLB value of >10 can advantageously be chosen from the following group: glyceryl stearate in a mixture with ceteareth-20, ceteareth-25, ceteareth-6 in a mixture with stearyl alcohol, cetylstearyl alcohol in a mixture with PEG-40 castor oil and sodium cetylstearyl sulfate, triceteareth-4 phosphate, glyceryl stearate, sodium cetylstearyl sulfate, lecithin trilaureth-4 phosphate, laureth-4 phosphate, stearic acid, propylene glycol stearate SE, PEG-9 stearate, PEG-20 stearate, PEG-30 stearate, PEG-40 stearate, PEG-100 stearate, ceteth-2, ceteth-20, polysorbate-20, polysorbate-60, polysorbate-65, polysorbate-100, glyceryl stearate in a mixture with PEG-100 stearate, ceteareth-3, isostearyl glyceryl ether, cetylstearyl alcohol in a mixture with sodium cetylstearyl sulfate, PEG-40 stearate, glycol distearate, PEG-22 dodecyl glycol copolymer, polyglyceryl-2 PEG-4 stearate, ceteareth-12, ceteareth-20, ceteareth-30, methylglucose sesquistearate, steareth-10, PEG-20 stearate, steareth-21, steareth-20, isosteareth-20, PEG-45/dodecyl glycol copolymer, methoxy-PEG-22/dodecyl glycol copolymer, glyceryl stearate SE, ceteth-20, PEG-20 methylglucose sesquistearate, glyceryl stearate citrate, cetyl phosphate, cetearyl sulfate, sorbitan sesquioleate, triceteareth-4 phosphate, trilaureth-4 phosphate, polyglyceryl methylglucose distearate, potassium cetyl phosphate, isosteareth-10, polyglyceryl-2 sesquiisostearate, ceteth-10, isoceteth-20, glyceryl stearate in a mixture with ceteareth-20, ceteareth-12, cetylstearyl alcohol and cetyl palmitate, PEG-30 stearate, PEG-40 stearate, PEG-100 stearate.
[0066] Aqueous-alcoholic solutions are also advantageous. They can comprise from 0% by weight to 90% by weight of ethanol. Aqueous-alcoholic solutions for the purposes of the present invention may advantageously also comprise solubility promoters, such as, for example, PEG-40 or PEG-60 hydrogenated castor oil.
[0067] The preparations according to the invention can advantageously also be used as cosmetic or dermatological impregnation solutions with which water-insoluble substrates in particular—such as, for example, woven or nonwoven wipes—are moistened. Impregnation solutions of this type are preferably of low viscosity, in particular sprayable (such as, for example, PIT emulsions, hydrodispersions, W/O emulsions, oils (see below), aqueous solutions etc.) and preferably have a viscosity of less than 2000 mPa·s, in particular less than 1500 mPa·s (measuring device: Haake Viskotester VT-02 at 25° C.). They can be used to obtain, for example, cosmetic sunscreen wipes, care wipes and the like, which represent the combination of a soft, water-insoluble material with the low viscosity cosmetic and dermatological impregnation solution.
[heading-0068] Oils
[0069] The preparations according to the invention can advantageously also be in the form of water-free oils or oil gels or pastes. Examples of advantageous oils are synthetic, semisynthetic or natural oils such as, for example, rapeseed oil, rice oil, avocado oil, olive oil, mineral oil, cocoglycerides, butylene glycol dicaprylate/dicaprate, C 12-15 alkyl benzoate, dicaprylyl carbonate, octyldodecanol and the like. Oil gel formers which may be used are diverse waxes with a melting point >25° C. Also advantageous are gel formers from the group of Aerosils, of alkyl galactomannans (e.g. N-Hance AG 200 and N-Hance AG 50 from Hercules) and polyethylene derivatives.
[heading-0070] Mousses
[0071] Also particularly advantageous for the purposes of the present invention are self-foaming, foam-like, after-foaming or foamable cosmetic and dermatological preparations.
[0072] “Self-foaming”, “foam-like”, “after-foaming” and “foamable” preparations are understood as meaning preparations from which foams can in principle be produced by introducing one or more gases—whether during the preparation process, whether upon use by the consumer or in another way. In such foams, the gas bubbles are (randomly) distributed in one (or more) liquid phase(s), where the (foamed) preparations do not necessarily have to have the appearance of a foam in macroscopic terms. Cosmetic or dermatological preparations (foamed) according to the invention (referred to below for the sake of simplicity also as foams) may, for example, be macroscopically visibly dispersed systems of gases dispersed in liquids. The foam character may, however, for example also only be visible under a (light) microscope. Moreover, foams according to the invention—particularly when the gas bubbles are too small to be seen under a light microscope—are also evident from the considerable volume increase of the system.
[0073] For the purposes of the present invention, such preparations advantageously comprise an emulsifier system which consists of
A. at least one emulsifier chosen from the group of completely neutralized, partially neutralized or unneutralized, branched r unbranched, saturated or unsaturated fatty acids with a chain length of from 10 to 40 carbon atoms, B. at least one emulsifier chosen from the group of polyethoxylated fatty acid esters with a chain length of from 10 to 40 carbon atoms and with a degree of ethoxylation of from 5 to 100 and C. at least one coemulsifier C chosen from the group of saturated or unsaturated, branched or unbranched fatty alcohols with a chain length of from 10 to 40 carbon atoms.
[0077] The emulsifier or emulsifiers A are preferably chosen from the group of fatty acids, which are completely or partially neutralized with customary alkalis (such as, for example, sodium hydroxide or potassium hydroxide, sodium carbonate or potassium carbonate, and mono- or triethanolamine). Stearic acid and stearates, isostearic acid and isostearates, palmitic acid and palmitates, and myristic acid and myristates, for example, are particularly advantageous.
[0078] The emulsifier or emulsifiers B are preferably chosen from the following group: PEG-9 stearate, PEG-8 distearate, PEG-20 stearate, PEG-8 stearate, PEG-8 oleate, PEG-25 glyceryl trioleate, PEG-40 sorbitan lanolate, PEG-15 glyceryl ricinoleate, PEG-20 glyceryl stearate, PEG-20 glyceryl isostearate, PEG-20 glyceryl oleate, PEG-20 stearate, PEG-20 methylglucose sesquistearate, PEG-30 glyceryl isostearate, PEG-20 glyceryl laurate, PEG-30 stearate, PEG-30 glyceryl stearate, PEG-40 stearate, PEG-30 glyceryl laurate, PEG-50 stearate, PEG-100 stearate, PEG-150 laurate. Polyethoxylated stearic esters, for example, are particularly advantageous.
[0079] According to the invention, the coemulsifier or the coemulsifiers C are preferably chosen from the following group: behenyl alcohol (C 22 H 45 OH), cetearyl alcohol [a mixture of cetyl alcohol (C 16 H 33 OH) and stearyl alcohol (C 18 H 37 OH)], lanolin alcohols (wool wax alcohols which are the unsaponifiable alcohol fraction of wool wax which is obtained following saponification of wool wax). Cetyl and cetylstearyl alcohol are particularly preferred.
[0080] It is advantageous according to the invention to choose the weight ratios of emulsifier A to emulsifier B to emulsifier C (A:B:C) as a:b:c, where a, b and c, independently of one another, may be rational numbers from 1 to 5, preferably from 1 to 3. A weight ratio of, for example, 1:1:1 is particularly preferred.
[0081] For the purposes of the present invention, it is advantageous to choose the total amount of the emulsifiers A and B and of coemulsifier C from the range from 2 to 20% by weight, advantageously from 5 to 15% by weight, in particular from 7 to 13% by weight, in each case based on the total weight of the formulation.
[heading-0082] Pickering/Solids-Stabilized Emulsions
[0083] Also particularly advantageous for the purposes of the present invention are cosmetic or dermatological preparations which have been stabilized only by very finely divided solids particles. Such “emulsifier-free” emulsions are also referred to as Pickering emulsions.
[0084] In Pickering emulsions, the solid material accumulates at the oil/water interface in the form of a layer, as a result of which coalescence of the disperse phases is prevented. Of essential importance here are, in particular, the surface properties of the solids particles, which should exhibit both hydrophilic and also lipophilic properties.
[0085] The stabilizing solids particles can also advantageously be treated (“coated”) to repel water, the intention being to form or retain an amphiphilic character of these solids particles. The surface treatment can consist in providing the solids particles with a thin hydrophobic or hydrophilic coat by processes known per se.
[0086] The average particle diameter of the microfine solids particles used as stabilizer is preferably chosen to be less than 100 μm, particularly advantageously less than 50 μm. In this connection, it is essentially unimportant in what form (platelets, rods, spheres, etc.) or modifications the solids particles used are present.
[0087] The microfine solids particles are preferably chosen from the group of amphiphilic metal oxide pigments. In particular,
titanium dioxides (coated and uncoated): e.g. Eusolex T-2000 from Merck, titanium dioxide MT-100 Z from Tayca Corporation zinc oxides, e.g. Z-Cote and Z-Cote HP1 from BASF AG, MZ-300, MZ-500 and MZ-505M from Tayca Corporation iron oxides
are advantageous.
[0092] Furthermore, it is advantageous when the microfine solids particles are chosen from the following group: boron nitrides, starch derivatives (tapioca starch, sodium corn starch octynyl succinate etc.), talc, latex particles.
[0093] It is advantageous according to the invention when the solids-stabilized emulsions comprise significantly less than 0.5% by weight of one or more emulsifiers or are even entirely emulsifier-free.
[heading-0094] Sticks
[0095] Also advantageous for the purposes of the invention are preparations in the form of sticks. Viewed technically, most stick formulations are anhydrous fatty mixtures of solid or semisolid waxes and liquid oils, where highly purified paraffin oils and paraffin waxes are the stick base.
[0096] Customary bases for stick preparations are, for example, liquid oils (such as, for example, paraffin oils, castor oil, isopropyl myristate, C 12-15 alkyl benzoate), semisolid constituents (e.g. vaseline, lanolin), solid constituents (e.g. beeswax, ceresin and microcrystalline waxes and ozokerite) or high-melting waxes (e.g. carnauba wax, candelilla wax). Water-containing stick preparations are also known per se, it being possible for these also to be present in the form of W/O emulsions.
[0097] The cosmetic or dermatological light-protective formulations according to the invention can have the customary composition and be used for cosmetic or dermatological light-protective, and also for the treatment, care and cleansing of the skin or of the hair and as a make-up product in decorative cosmetics.
[0098] Depending on their formulation, cosmetic or topical dermatological compositions for the purposes of the present invention can, for example, be used as skin protection cream, cleansing milk, day or night cream etc. It is optionally possible and advantageous to use the compositions according to the invention as a base for pharmaceutical formulations.
[0099] For use, the cosmetic and dermatological preparations are applied to the skin or the hair in an adequate amount in the manner customary for cosmetics.
[0100] The cosmetic and dermatological preparations according to the invention can comprise cosmetic auxiliaries as are customarily used in such preparations, e.g. preservatives, preservative aids, complexing agents, bactericides, perfumes, substances for preventing or increasing foaming, dyes, pigments which have a coloring action, thickeners, moisturizing or humectant substances, fillers which improve the feel on the skin, fats, oils, waxes or other customary constituents of a cosmetic or dermatological formulation, such as alcohols, polyols, polymers, foam stabilizers, electrolytes, organic solvents or silicone derivatives.
[0101] Advantageous preservatives for the purposes of the present invention are, for example, formaldehyde donors (such as, for example, DMDM hydantoin, which is available, for example, under the trade name Glydant™ from Lonza), iodopropyl butylcarbamates (e.g. those available under the trade names Glycacil-L, Glycacil-S from Lonza, or Dekaben LMB from Jan Dekker), parabens (i.e. alkyl p-hydroxybenzoates, such as methyl-, ethyl-, propyl- or butylparaben), phenoxyethanol, ethanol, benzoic acid and the like. In addition, the preservative system according to the invention also usually advantageously comprises preservative aids, such as, for example, octoxyglycerol, glycine soya etc.
[0102] Advantageous complexing agents for the purposes of the present invention are, for example, EDTA, [S,S]-ethylenediamine disuccinate (EDDS), which is available, for example, under the trade name Octaquest from Octel, pentasodium ethylenediamine tetramethylenephosphonate, which is available, for example, under the trade name Dequest 2046 from Monsanto or iminodisuccinic acid, which is available, inter alia, from Bayer AG under the trade names Iminodisuccinate VP OC 370 (about 30% strength solution) and Baypure CX 100 solid.
[0103] Particularly advantageous preparations are also obtained when antioxidants are used as additives or active ingredients. According to the invention, the preparations advantageously comprise one or more antioxidants. Favorable, but nevertheless optional, antioxidants which may be used are all antioxidants customary or suitable for cosmetic or dermatological applications.
[0104] For the purposes of the present invention, water-soluble antioxidants may be used particularly advantageously, such as, for example, vitamins, e.g. ascorbic acid and derivatives thereof.
[0105] Preferred antioxidants are also vitamin E and derivatives thereof, and vitamin A and derivatives thereof.
[0106] The amount of antioxidants (one or more compounds) in the preparations is preferably 0.001 to 30% by weight, particularly preferably 0.05 to 20% by weight, in particular 0.1 to 10% by weight, based on the total weight of the preparation.
[0107] If vitamin E or derivatives thereof are the antioxidant or the antioxidants, it is advantageous to choose their respective concentrations from the range from 0.001 to 10% by weight, based on the total weight of the formulation.
[0108] If vitamin A or vitamin A derivatives, or carotenes or derivatives thereof are the antioxidant or the antioxidants, it is advantageous to choose their respective concentrations from the range from 0.001 to 10% by weight, based on the total weight of the formulation.
[0109] It is particularly advantageous when the cosmetic preparations according to the present invention comprise cosmetic or dermatological active ingredients, preferred active ingredients being antioxidants which can protect the skin against oxidative stress.
[0110] Further advantageous active ingredients for the purposes of the present invention are natural active ingredients or derivatives thereof, such as, for example, α-lipoic acid, phytoene, D-biotin, coenzyme Q10, α-glucosylrutin, carnitine, carnosine, natural or synthetic isoflavonoids, creatine, taurine or β-alanine, and 8-hexadecene-1,16-dicarboxylic acid (dioic acid, CAS number 20701-68-2; provisional INCI name Octadecenedioic acid).
[0111] Formulations according to the invention which comprise, for example, known antiwrinkle active ingredients, such as flavone glycosides (in particular α-glycosylrutin), coenzyme Q10, vitamin E and derivatives and the like are particularly advantageously suitable for the prophylaxis and treatment of cosmetic or dermatological changes in the skin, as arise, for example, during the skin aging (such as, for example, dryness, roughness and formation of dryness wrinkles, itching, reduced refatting (e.g. after washing), visible vascular dilations (telangiectases, cuperosis), flaccidity and formation of wrinkles and lines, local hyperpigmentation, hypopigmentation and incorrect pigmentation (e.g. age spots), increased susceptibility to mechanical stress (e.g. cracking) and the like). In addition, they are advantageously suitable to counter the appearance of dry or rough skin.
[0112] The water phase of the preparations according to the invention can advantageously comprise customary cosmetic auxiliaries, such as, for example, alcohols, in particular those of low carbon number, preferably ethanol or isopropanol, diols or polyols of low carbon number, and ethers thereof, preferably propylene glycol, glycerol, butylene glycol, ethylene glycol, ethylene glycol monoethyl or monobutyl ether, propylene glycol monomethyl, monoethyl or monobutyl ether, diethylene glycol monomethyl or monoethyl ether and analogous products, polymers, foam stabilizers, electrolytes, and in particular one or more thickeners, which may advantageously be chosen from the group consisting of silicon dioxide, aluminum silicates or polysaccharides or derivatives thereof, e.g. hyaluronic acid, xanthan gum, hydroxypropylmethylcellulose, particularly advantageously from the group of polyacrylates, preferably a polyacrylate from the group of so-called Carbopols [from Bf. Goodrich], for example carbopol grades 980, 981, 1382, 2984, 5984, ETD 2020, ETD 2050, Ultrez 10, in each case individually or in combination.
[0113] In addition, the preparations according to the invention can advantageously also comprise self-tanning substances, such as, for example, dihydroxyacetone or melanin derivatives in concentrations of from 1% by weight to 8% by weight, based on the total weight of the preparation.
[0114] In addition, the preparations according to the invention can advantageously also comprise repellents for protection against flies, ticks and spiders and the like. For example, N,N-diethyl-3-methylbenzamide (trade name: Meta-delphene, “DEET”), dimethyl phthalate (trade name: Palatinol M, DMP) and in particular ethyl 3-(N-n-butyl-N-acetylamino)propionate (available under the trade name Insekt Repellent® 3535 from Merck). The repellents can either be used individually or in combination.
[0115] Moisturizers is the term used to refer to substances or mixtures of substances which impart to cosmetic or dermatological preparations the property, following application or distribution on the surface of the skin, of reducing moisture release by the horny layer (also called trans-epidermal water loss (TEWL)) or of positively influencing hydration of the horny layer.
[0116] Advantageous moisturizers for the purposes of the present invention are, for example, glycerol, lactic acid, and lactates, in particular sodium lactate, butylene glycol, propylene glycol, biosaccharide gum-1, glycine soya, ethylhexyloxyglycerol, pyrrolidone-carboxylic acid and urea. In addition, it is particularly advantageous to use polymeric moisturizers from the group of water-soluble or water-swellable or water-gelable polysaccharides. Hyaluronic acid, chitosan, and a fucose-rich polysaccharide, which is filed in the Chemical Abstracts under the registry number 178463-23-5 and which is available, for example, under the name Fucogel® 1000 by SOLABIA S.A., for example, are particularly advantageous. Moisturizers can advantageously also be used as anti-wrinkle active ingredients for the prophylaxis and treatment of cosmetic or dermatological changes in the skin, as arise, for example, during skin aging.
[0117] The cosmetic or dermatological preparations according to the invention can also advantageously, but not necessarily, comprise fillers, which, for example, further improve the sensory and cosmetic properties of the formulations and, for example, bring about or enhance a velvety or silky feel on the skin. Advantageous fillers for the purposes of the present invention are starch and starch derivatives (such as, for example, tapioca starch, distarch phosphate, aluminum or sodium starch octenylsuccinate and the like), pigments which have neither a primarily UV filter effect nor a coloring effect (such as, for example, boron nitride etc.), or Aerosils® (CAS No. 7631-86-9).
[0118] The oil phase of the formulations according to the invention is advantageously chosen from the group of polar oils, for example from the group of lecithins and of fatty acid triglycerides, namely the triglycerol esters of saturated or unsaturated, branched or unbranched alkanecarboxylic acids with a chain length of from 8 to 24, in particular 12 to 18, carbon atoms. The fatty acid triglycerides can, for example, advantageously be chosen from the group of synthetic, semisynthetic and natural oils, such as, for example, cocoglyceride, olive oil, sunflower oil, soybean oil, peanut oil, rapeseed oil, almond oil, palm oil, coconut oil, castor oil, wheat germ oil, grape seed oil, thistle oil, evening primrose oil, macadamia nut oil and the like.
[0119] Also advantageous according to the invention are, for example, natural waxes of animal and vegetable origin, such as, for example, beeswax and other insect waxes, and berry wax, shea butter and lanolin (wool wax).
[0120] For the purposes of the present invention, further advantageous polar oil components may also be chosen from the group of esters of saturated or unsaturated, branched or unbranched alkanecarboxylic acids with a chain length of from 3 to 30 carbon atoms and saturated or unsaturated, branched or unbranched alcohols with a chain length of from 3 to 30 carbon atoms, and from the group of esters of aromatic carboxylic acids and saturated or unsaturated, branched or unbranched alcohols with a chain length of from 3 to 30 carbon atoms. Such ester oils can then advantageously be chosen from the group consisting of octyl palmitate, octyl cocoate, octyl isostearate, octyldodeceyl myristate, octyldodecanol, cetearyl isononanoate, isopropyl myristate, isopropyl palmitate, isopropyl stearate, isopropyl oleate, n-butyl stearate, n-hexyl laurate, n-decyl oleate, isooctyl stearate, isononyl stearate, isononyl isononanoate, 2-ethylhexyl palmitate, 2-ethylhexyl laurate, 2-hexyldecyl stearate, 2-octyldodecyl palmitate, stearyl heptanoate, oleyl oleate, oleyl erucate, erucyl oleate, erucyl erucate, tridecyl stearate, tridecyl trimellitate, and synthetic, semisynthetic and natural mixtures of such esters, such as, for example, jojoba oil.
[0121] In addition, the oil phase can advantageously be chosen from the group of dialkyl ethers and dialkyl carbonates, advantageous examples being dicaprylyl ether (cetiol OE) or dicaprylyl carbonate, for example, that is obtainable under the trade name Cetiol CC from Cognis.
[0122] It is also preferred the oil component or components from the group consisting of isoeicosane, neopentyl glycol diheptanoate, propylene glycol dicaprylate/dicaprate, caprylic/capric/diglyceryl succinate, butylene glycol dicaprylate/dicaprate, C 12-13 -alkyl lactate, di-C 12-13 -alkyl tartrate, triisostearin, dipentaerythrityl hexacaprylate/hexacaprate, propylene glycol monoisostearate, tricaprylin, dimethyl isosorbide. It is particularly advantageous when the oil phase of the formulations according to the invention has a content of C 12-15 -alkyl benzoate or consists entirely of this.
[0123] Advantageous oil components are also, for example, butyloctyl salicylate (for example that available under the trade name Hallbrite BHB from CP Hall), hexadecyl benzoate and butyloctyl benzoate and mixtures thereof (Hallstar AB) and diethylhexyl naphthalate (Hallbrite TQ or Corapan TQ from H&R).
[0124] Any mixtures of such oil and wax components can also be used advantageously for the purposes of the present invention.
[0125] In addition, the oil phase can likewise advantageously also comprise nonpolar oils, for example those which are chosen from the group of branched and unbranched hydrocarbons and hydrocarbon waxes, in particular mineral oil, vaseline (petrolatum), paraffin oil, squalane and squalene, polyolefins, hydrogenated polyisobutenes and isohexadecane. Among the polyolefins, polydecenes are the preferred substances.
[0126] The oil phase can advantageously also have a content of cyclic or linear silicone oils or consist entirely of such oils, although it is preferred to use an additional content of other oil phase components apart from the silicone oil or the silicone oils.
[0127] Silicone oils are high molecular weight synthetic polymeric compounds in which silicon atoms are joined via oxygen atoms in a chain-like or in a reticular manner and the remaining valences of the silicon are saturated by hydrocarbon radicals (in most cases methyl groups, more rarely ethyl, propyl, phenyl groups etc.). Systematically, the silicone oils are referred to as polyorganosiloxanes. The methyl-substituted polyorganosiloxanes, which represent the most significant compounds of this group in terms of amount and are characterized by the following structural formula
are also referred to as polydimethylsiloxane or Dimethicone (INCI). Dimethicones have various chain lengths and various molecular weights.
[0129] Particularly advantageous polyorganosiloxanes for the purposes of the present invention are, for example, dimethylpolysiloxanes [poly(dimethylsiloxane)], which are available, for example, under the trade names Abil 10 to 10 000 from Th. Goldschmidt. Also advantageous are phenylmethylpolysiloxanes (INCI: Phenyl Dimethicone, Phenyl Trimethicone), cyclic silicones (octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane), which are also referred to as cyclomethicones in accordance with INCI, amino-modified silicones (INCI: Amodimethicones) and silicone waxes, e.g. polysiloxane-polyalkylene copolymers (INCI: Stearyl Dimethicone and Cetyl Dimethicone) and dialkoxydimethylpolysiloxanes (stearoxy dimethicone and behenoxy stearyl dimethicone), which are available as various Abil wax grades from Th. Goldschmidt. However, other silicone oils can also be used advantageously for the purposes of the present invention, for example cetyldimethicone, hexamethylcyclotrisiloxane, polydimethylsiloxane, poly(methylphenylsiloxane).
[0130] The preparations according to the invention can also advantageously comprise one or more substances from the following group of siloxane elastomers, for example in order to increase the water resistance or the light-protective factor of the products:
(a) siloxane elastomers which contain the units R 2 SiO and RSiO 1.5 or R 3 SiO 0.5 or SiO 2 ,
where the individual radicals R, in each case independently of one another, are hydrogen, C 1-24 -alkyl (such as, for example, methyl, ethyl, propyl) or aryl (such as, for example, phenyl or tolyl), alkenyl (such as, for example, vinyl), and the weight ratio of the units R 2 SiO to RSiO 1.5 is chosen from the range from 1:1 to 30:1;
(b) siloxane elastomers which are insoluble and swellable in silicone oil and which are obtainable by the addition reaction of an organopolysiloxane (1) which contains silicon-bonded hydrogen with an organopolysiloxane (2) which contains unsaturated aliphatic groups,
where the quantitative amounts used are chosen such that the amount of hydrogen in the organopolysiloxane (1) or in the unsaturated aliphatic groups of the organopolysiloxane (2)
is in the range from 1 to 20 mol % when the organopolysiloxane is noncyclic and is in the range from 1 to 50 mol % when the organopolysiloxane is cyclic.
[0137] For the purposes of the present invention, the siloxane elastomer or elastomers are advantageously present in the form of spherical powders or in the form of gels.
[0138] Siloxane elastomers present in the form of spherical powders which are advantageous according to the invention are those with the INCI name Dimethicone/Vinyl Dimethicone Crosspolymer, for example that available from DOW CORNING under the trade names DOW CORNING 9506 Powder.
[0139] It is particularly preferred when the siloxane elastomer is used in combination with oils from hydrocarbons of animal or vegetable origin, synthetic oils, synthetic esters, synthetic ethers or mixtures thereof.
[0140] It is very particularly preferred when the siloxane elastomer is used in combination with unbranched silicone oils which are liquid or pasty at room temperature or cyclic silicone oils or mixtures thereof. Organopolysiloxane elastomers with the INCI name Dimethicone/Polysilicone-11, very particularly the Gransil grades obtainable from Grant Industries Inc. GCM, GCM-5, DMG-6, CSE gel, PM-gel, LTX, ININ gel, AM-18 gel and DMCM-5 are particularly advantageous.
[0141] It is very extremely preferred when the siloxane elastomer is used in the form of a gel of siloxane elastomer and a lipid phase where the content of the siloxane elastomer in the gel is 1 to 80% by weight, preferably 0.1 to 60% by weight, in each case based on the total weight of the gel.
[0142] It is advantageous for the purposes of the present invention to choose the total amount of the siloxane elastomers (active content) from the range from 0.01 to 10% by weight, advantageously from 0.1 to 5% by weight, in each case based on the total weight of the formulation.
[0143] The cosmetic and dermatological preparations according to the invention can comprise dyes or color pigments, particularly when they are in the form of decorative cosmetics. The dyes and color pigments can be chosen from the corresponding positive list in the Cosmetics Directive or the EC list of cosmetic colorants. In most cases, they are identical to dyes approved for foods. Advantageous color pigments are, for example, titanium dioxide, mica, iron oxides (e.g. Fe 2 O 3 , Fe 3 O 4 , FeO(OH)) and tin oxide. Advantageous dyes are, for example, carmine, Prussian blue, chromium oxide green, ultramarine blue and manganese violet. It is particularly advantageous to choose the dyes or the color pigments from the Rowe Colour Index, 3 rd Edition, Society of Dyers and Colourists, Bradford, England, 1971.
[0144] If the formulations according to the invention are in the form of products which are used on the face, it is favorable to choose one or more substances from the following group as the dye: 2,4-dihydroxyazobenzene, 1-(2′-chloro-4′-nitro-1′-phenylazo)-2-hydroxynaphthalene, Ceres red, 2-(sulfo-1-naphthylazo)-1-naphthol-4-sulfonic acid, calcium salt of 2-hydroxy-1,2′-azonaphthalene-1′-sulfonic acid, calcium and barium salts of 1-(2-sulfo-4-methyl-1-phenylazo)-2-naphthylcarboxylic acid, calcium salt of 1-(2-sulfo-1-naphthylazo)-2-hydroxynaphthalene-3-carboxylic acid, aluminum salt of 1-(4-sulfo-1-phenylazo)-2-naphthyl-6-sulfonic acid, aluminum salt of 1-(4-sulfo-1-naphthylazo-2-naphthyl-3,6-disulfonic acid, 1-(4-sulfo-1-naphthylazo)-2-naphthol-6,8-disulfonic acid, aluminum salt of 4-(4-sulfo-1-phenylazo)-1-(4-sulfophenyl)-5-hydroxypyrazolone-3-carboxylic acid, aluminum and zirconium salts of 4,5-dibromofluorescein, aluminum and zirconium salts of 2,4,5,7-tetrabromofluorescein, 3′,4′,5′,6′-tetrachloro-2,4,5,7-tetrabromofluorescein and its aluminum salt, aluminum salt of 2,4,5,7-tetraiodofluorescein, aluminum salt of quinophthalonedisulfonic acid, aluminum salt of indigodisulfonic acid, red and black iron oxide (CIN: 77 491 (red) and 77 499 (black)), iron oxide hydrate (CIN: 77 492), manganese ammonium diphosphate and titanium dioxide.
[0145] Also advantageous are oil-soluble natural dyes, such as, for example, paprika extracts, β-carotene or cochineal.
[0146] Also advantageous for the purposes of the present invention are formulations with a content of pearlescent pigments. Preference is given in particular to the types of pearlescent pigments listed below:
1. Natural pearlescent pigments, such as, for example,
“pearlessence” (guanine/hypoxanthin mixed crystals from fish scales) and “mother-of-pearl” (ground mussel shells)
2. Monocrystalline pearlescent pigments, such as, for example, bismuth oxychloride (BiOCl) 3. Layer-substrate pigments: e.g. mica/metal oxide
[0152] Bases for pearlescent pigments are, for example, pulverulent pigments or castor oil dispersions of bismuth oxychloride or titanium dioxide, and bismuth oxychloride or titanium dioxide on mica. The luster pigment listed under CIN 77163, for example, is particularly advantageous.
[0153] Also advantageous are, for example, the following types of pearlescent pigments based on mica/metal oxide:
Group Coating/layer thickness Color Silver-white pearlescent TiO 2 : 40-60 nm Silver pigments Interference pigments TiO 2 : 60-80 nm Yellow TiO 2 : 80-100 nm Red TiO 2 : 100-140 nm Blue TiO 2 : 120-160 nm Green Color luster pigments Fe 2 O 3 Bronze Fe 2 O 3 Copper Fe 2 O 3 Red Fe 2 O 3 Red-violet Fe 2 O 3 Red-green Fe 2 O 3 Black Combination pigments TiO 2 /Fe 2 O 3 Gold shades TiO 2 /Cr 2 O 3 Green TiO 2 /Prussian blue Deep blue TiO 2 /carmine Red
[0154] Particular preference is given, for example, to the pearlescent pigments obtainable from Merck under the trade names Timiron, Colorona or Dichrona.
[0155] The list of given pearlescent pigments is not of course intended to be limiting. Pearlescent pigments which are advantageous for the purposes of the present invention are obtainable by numerous methods known per se. For example, other substrates apart from mica can be coated with further metal oxides, such as, for example, silica and the like. SiO 2 particles coated with, for example, TiO 2 and Fe 2 O 3 (“ronaspheres”), which are sold by Merck and are particularly suitable for the optical reduction of fine lines, are suitable.
[0156] It can, moreover, be advantageous to dispense completely with a substrate such as mica. Particular preference is given to iron pearlescent pigments prepared without the use of mica. Such pigments are obtainable, for example, under the trade name Sicopearl Kupfer 1000 from BASF.
[0157] In addition, also particularly advantageous are effect pigments which are obtainable under the trade name Metasomes Standard/Glitter in various colors (yellow, red, green, blue) from Flora Tech. The glitter particles are present here in mixtures with various auxiliaries and dyes (such as, for example, the dyes with the Colour Index (CI) numbers 19140, 77007, 77289, 77491).
[0158] The dyes and pigments may be present either individually or in a mixture, and can be mutually coated with one another, different coating thicknesses generally giving rise to different color effects. The total amount of dyes and color-imparting pigments is advantageously chosen from the range from, for example, 0.1% by weight to 30% by weight, preferably from 0.5 to 15% by weight, in particular from 1.0 to 10% by weight, in each case based on the total weight of the preparations.
[0159] For the purposes of the present invention, it is also advantageous to provide cosmetic and dermatological preparations whose main purpose is not protection against sunlight, but which nevertheless have a content of further UV protection substances. Thus, for example, UV-A and/or UV-B filter substances are usually incorporated into daycreams or make-up products. UV protection substances, like antioxidants and, if desired, preservatives, also constitute effective protection of the preparations themselves against spoilage. Also favorable are cosmetic and dermatological preparations in the form of a sunscreen.
[0160] Accordingly, for the purposes of the present invention, the preparations preferably additionally comprise at least one further UV-A, UV-B, or broadband filter substance. The formulations can, but do not necessarily, optionally comprise one or more organic or inorganic pigments as UV filter substances, which may be present in the water phase and/or the oil phase.
[0161] In addition, the preparations according to the invention can also advantageously be in the form of so-called oil-free cosmetic or dermatological emulsions, which comprise a water phase and at least one UV filter substance which is liquid at room temperature as a further phase.
[0162] For the purposes of the present invention, particularly advantageous UV filter substances which are liquid at room temperature are homomenthyl salicylate (INCI: Homosalate), 2-ethylhexyl 2-cyano-3,3-diphenylacrylate (INCI: Octocrylene), 2-ethylhexyl 2-hydroxybenzoate (2-ethylhexyl salicylate octyl salicylate, INCI: Octyl Salicylate) and esters of cinnamic acid, preferably 2-ethylhexyl 4-methoxycinnamate (INCI: Octyl Methoxycinnamate) and isopentyl 4-methoxycinnamate (INCI: Isoamyl p-Methoxycinnamate), 3-(4-(2,2-bisethoxycarbonylvinyl)phenoxy)propenyl)methoxy-siloxane/dimethylsiloxane copolymer, which is available, for example, under the trade name Parsol® SLX from Hoffmann La Roche.
[0163] Preferred inorganic pigments are metal oxides or other metal compounds which are insoluble or sparingly soluble in water, in particular oxides of titanium (TiO 2 ), zinc (ZnO), iron (e.g. Fe 2 O 3 ), zirconium (ZrO 2 ), silicon (SiO 2 ), manganese (e.g. MnO), aluminum (Al 2 O 3 ), cerium (e.g. Ce 2 O 3 ), mixed oxides of the corresponding metals, and mixtures of such oxides, and also the sulfate of barium (BaSO 4 ).
[0164] For the purposes of the present invention, the pigments may advantageously also be used in the form of commercially available oily or aqueous predispersions. Dispersion auxiliaries or solubility promoters may advantageously be added to these predispersions.
[0165] According to the invention, the pigments may advantageously be surface-treated (“coated”), the intention being to form or retain, for example, a hydrophilic, amphiphilic or hydrophobic character. This surface treatment can consist in providing the pigments with a thin hydrophilic or hydrophobic inorganic or organic coat by methods known per se. For the purposes of the present invention, the various surface coatings may also comprise water.
[0166] Inorganic surface coatings for the purposes of the present invention may consist of aluminum oxide (Al 2 O 3 ), aluminum hydroxide Al(OH) 3 , or aluminum oxide hydrate (also: alumina, CAS No.: 1333-84-2), sodium hexametaphosphate (NaPO 3 ) 6 , sodium metaphosphate (NaPO 3 ) n , silicon dioxide (SiO 2 ) (also: silica, CAS No.: 7631-86-9), or iron oxide (Fe 2 O 3 ). These inorganic surface coatings may be present on their own, in combination or in combination with organic coating materials.
[0167] Organic surface coatings for the purposes of the present invention may consist of vegetable or animal aluminum stearate, vegetable or animal stearic acid, lauric acid, dimethylpolysiloxane (also: Dimethicone), methylpolysiloxane (Methicone), simethicone (a mixture of dimethylpolysiloxane with an average chain length of from 200 to 350 dimethylsiloxane units and silica gel) or alginic acid. These organic surface coatings may be present on their own, in combination or in combination with inorganic coating materials.
[0168] Zinc oxide particles and predispersions of zinc oxide particles which are suitable according to the invention are obtainable under the following trade names from the companies listed:
Trade name Coating Manufacturer Z-Cote HP1 2% Dimethicone BASF Z-Cote / BASF ZnO NDM 5% Dimethicone H&R MZ-303S 3% Methicone Tayca Corporation MZ-505S 5% Methicone Tayca Corporation
[0169] Suitable titanium dioxide particles and predispersions of titanium dioxide particles are available under the following trade names from the companies listed:
Trade name Coating Manufacturer MT-100TV Aluminum hydroxide/ Tayca Corporation stearic acid MT-100Z Aluminum hydroxide/ Tayca Corporation stearic acid Eusolex Alumina/Simethicone Merck KgaA T-2000 Titanium dioxide Octyltrimethylsilane Degussa T805 (Uvinul TiO 2 ) Tioveil AQ Alumina/Silica Solaveil/Uniquema 10PG
[0170] Further advantageous pigments are latex particles. Latex particles advantageous according to the invention are those described in the following specifications: U.S. Pat. No. 5,663,213 and EP 0 761 201. Particularly advantageous latex particles are those which are formed from water and styrene/acrylate copolymers and are available, for example, under the trade name “Alliance SunSphere” from Rohm & Haas.
[0171] Advantageous UV-A filter substances for the purposes of the present invention are dibenzoylmethane derivatives, in particular 4-(tert-butyl)-4′-methoxydibenzoyl-methane (CAS No. 70356-09-1), which is sold by Givaudan under the name Parsol® 1789 and by Merck under the trade name Eusolex® 9020.
[0172] Further advantageous UV-A filter substances for the purposes of the present invention are hydroxybenzophenones which are characterized by the following structural formula:
in which
R 1 and R 2 , independently of one another, are hydrogen, C 1 -C 20 -alkyl, C 3 -C 10 -cycloalkyl or C 3 -C 10 -cycloalkenyl, where the substituents R 1 and R 2 , together with the nitrogen atom to which they are bonded, can form a 5-membered or 6-membered ring and R 3 is a C 1 -C 20 -alkyl radical.
[0176] A particularly advantageous hydroxybenzophenone for the purposes of the present invention is hexyl 2-(4′-diethylamino-2′-hydroxybenzoyl)benzoate (also: Aminobenzophenone), which is characterized by the following structure:
and is available under Uvinul A Plus from BASF.
[0178] Advantageous further UV filter substances for the purposes of the present invention are sulfonated, water-soluble UV filters, such as, for example:
Phenylene-1,4-bis(2-benzimidazyl)-3,3′-5,5′-tetrasulfonic acid and its salts, particularly the corresponding sodium, potassium or triethanolammonium salts, in particular the phenylene-1,4-bis(2-benzimidazyl)-3,3′-5,5′-tetrasulfonic acid bis-sodium salt with the INCI name Bisimidazylate (CAS No.: 180898-37-7), which is available, for example, under the trade name Neo Heliopan AP from Haarmann & Reimer; Salts of 2-phenylbenzimidazole-5-sulfonic acid, such as its sodium, potassium or its triethanolammonium salt, and the sulfonic acid itself with the INCI name Phenylbenzimidazole Sulfonic Acid (CAS No. 27503-81-7), which is available under the trade name Eusolex 232 from Merck, or under Neo Heliopan Hydro from Haarmann & Reimer; 1,4-di(2-oxo-10-sulfo-3-bornylidenemethyl)benzene (also: 3,3′-(1,4-phenylene-dimethylene)bis(7,7-dimethyl-2-oxobicyclo[2.2.1]hept-1-ylmethanesulfonic acid) and salts thereof (particularly the corresponding 10-sulfato compounds, in particular the corresponding sodium, potassium or triethanolammonium salt), which is also referred to as benzene-1,4-di(2-oxo-3-bornylidenemethyl-10-sulfonic acid). Benzene-1,4-di(2-oxo-3-bornylidenemethyl-10-sulfonic acid) has the INCI name Terephthalidene Dicamphor Sulfonic Acid (CAS No.: 90457-82-2) and is available, for example, under the trade name Mexoryl SX from Chimex; sulfonic acid derivatives of 3-benzylidenecamphor, such as, for example, 4-(2-oxo-3-bornylidenemethyl)benzenesulfonic acid, 2-methyl-5-(2-oxo-3-bornylidenemethyl)sulfonic acid and salts thereof.
[0183] Advantageous UV filter substances for the purposes of the present invention are also so-called broadband filters, i.e. filter substances which absorb both UV-A and also UV-B radiation.
[0184] Advantageous broadband filters or UV-B filter substances are, for example, triazine derivatives, such as, for example,
2,4-bis{[4-(2-ethylhexyloxy)-2-hydroxy]phenyl}-6-(4-methoxyphenyl)-1,3,5-triazine (INCI: BisEthylhexyloxyphenol Methoxyphenyl Triazine), which is available under the trade name Tinosorb® S from CIBA-Chemikalien GmbH; dioctylbutylamidotriazone (INCI: Dioctylbutamidotriazone), which is available under the trade name UVASORB HEB from Sigma 3V; Tris(2-ethylhexyl) 4,4′,4″-(1,3,5-triazine-2,4,6-triyltriimino)trisbenzoate, also: 2,4,6-tris[anilino(p-carbo-2′-ethyl-1′-hexyloxy)]-1,3,5-triazine (INCI: Octyl Triazone), which is sold by BASF Aktiengesellschaft under the trade name UVINUL® T 150; 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-(octyloxy)phenol (CAS No.: 2725-22-6).
[0189] The further UV filter substances may be oil-soluble or water-soluble. Advantageous oil-soluble filter substances are, for example:
3-benzylidenecamphor derivatives, preferably 3-(4-methylbenzylidene)camphor, 3-benzylidenecamphor; 4-aminobenzoic acid derivatives, preferably 2-ethylhexyl 4-(dimethyl-amino)benzoate, amyl 4-(dimethylamino)benzoate; 2,4,6-trianilino(p-carbo-2′-ethyl-1′-hexyloxy)-1,3,5-triazine; esters of benzalmalonic acid, preferably di(2-ethylhexyl) 4-methoxybenzalmalonate; esters of cinnamic acid, preferably 2-ethylhexyl 4-methoxycinnamate, isopentyl 4-methoxycinnamate; derivatives of benzophenone, preferably 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4′-methylbenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone and UV filters bonded to polymers.
[0197] Advantageous water-soluble filter substances are, for example:
Sulfonic acid derivatives of 3-benzylidenecamphor, such as, for example, 4-(2-oxo-3-bornylidenemethyl)benzenesulfonic acid, 2-methyl-5-(2-oxo-3-bornylidene-methyl)sulfonic acid and salts thereof.
[0199] A further light-protective filter substance to be used advantageously according to the invention is ethylhexyl 2-cyano-3,3-diphenylacrylate (octocrylene), which is available from BASF under the name Uvinul® N 539 T.
[0200] Besides the filter substance(s) according to the invention, particularly advantageous preparations for the purposes of the present invention which are characterized by high or very high UV-A protection preferably also comprise further UV-A or broadband filters, in particular dibenzoylmethane derivatives [for example 4-(tert-butyl)-4′-methoxydibenzoylmethane] or 2,4-bis{[4-(2-ethylhexyloxy)-2-hydroxy]phenyl}-6-(4-methoxyphenyl)-1,3,5-triazine or hexyl 2-(4′-diethylamino-2′-hydroxybenzoyl)benzoate, in each case individually or in any combinations with one another.
[0201] The list of given UV filters which can be used for the purposes of the present invention is not of course intended to be limiting.
[0202] The preparations according to the invention advantageously comprise the substances which absorb UV radiation in the UV-A and/or UV-B region in a total amount of, for example, from 0.1% by weight to 30% by weight, preferably from 0.5 to 20% by weight, in particular 1.0 to 15.0% by weight, in each case based on the total weight of the preparations, in order to provide cosmetic preparations which protect the hair or the skin from the entire range of ultraviolet radiation.
[0203] In addition, it may in some instances be advantageous to incorporate film formers into the cosmetic or dermatological preparations according to the invention, for example in order to improve the water resistance of the preparations, or to increase the UV protection performance (UV-A and/or UV-B boosting). Both water-soluble or dispersible and also fat-soluble film formers are suitable, in each case individually or in combination with one another.
[0204] Advantageous water-soluble or dispersible film formers are, for example, polyurethanes (e.g. the Avalure® grades from Goodrich), Dimethicone Copolyol Polyacrylate (Silsoft Surface® from the Witco Organa Silicones Group), PVPNA (VA=vinyl acetate) copolymer (Luviscol VA 64 Powder from BASF), C 20-40 carboxylic acid with polyethylene (Performacid 350 from New Phase Technologies) etc.
[0205] Advantageous fat-soluble film formers are, for example, the film formers from the group of polymers based on polyvinylpyrrolidone (PVP)
[0206] Particular preference is given to copolymers of polyvinylpyrrolidone, for example the PVP hexadecene copolymer and the PVP eicosene copolymer, which are available under the trade names Antaron V216 and Antaron V220 from GAF Chemicals Cooperation, and also Tricontayl PVP and the like.
[0207] The examples below are intended to illustrate the present invention without limiting it. The numerical values in the examples are percentages by weight, based on the total weight of the respective preparations.
EXAMPLES
[heading-0208] In the following examples:
[none]
UVASorb® K2A=2,4-bis[5-1(dimethylpropyl)benzoxazol-2-yl-(4-phenyl)imino]-6-(2-ethylhexyl)imino-1,3,5-triazine [CAS No. 288254-16-0]
Uvinul® A Plus=hexyl 2-(4′-diethylamino-2′-hydroxybenzoyl)benzoate (also: amino-benzophenone)
[0211] 1. O/W Sunscreen Emulsions
1 2 3 4 5 6 7 Glycerol monostearate SE 0.50 1.00 3.00 1.50 Glyceryl stearate citrate 2.00 1.00 2.00 2.50 Stearic acid 3.00 0.75 2.00 PEG-40 stearate 0.50 2.00 PEG-100 stearate 1.50 Lauryl methicone copolyol 0.75 0.50 Cetyl phosphate 0.75 1.00 Stearyl alcohol 3.00 2.00 0.50 Cetyl alcohol 2.50 1.00 0.50 2.00 UVASorb ® K2A 1.00 2.50 3.00 4.00 1.50 5.00 1.00 Methylenebisbenzotriazolyl 2.00 5.00 tetramethylbutylphenol Drometrizole trisiloxane 1.00 4.50 0.50 2.00 1.00 5.00 Bisethylhexyloxyphenol 0.50 1.00 0.50 methoxyphenyltriazine Disodium phenyl 0.50 2.00 dibenzimidazole tetrasulfonate Ethylhexyltriazone 2.00 2.00 2.00 Diethylhexylbutamidotriazone 2.00 Ethylhexyl 3.50 10.00 methoxycinnamate Octocrylene 10.00 5.00 9.00 7.50 2.50 Ethylhexyl salicylate 3.00 5.00 Titanium dioxide T 805 1.50 1.00 0.50 Titanium dioxide MT-100Z 1.00 3.00 1.00 C12-15 Alkyl benzoate 2.50 7.00 5.00 Dicaprylyl ether 3.50 2.00 Butylene glycol 5.00 5.00 3.00 dicaprylate/dicaprate Cetearyl isononanoate 4.00 2.00 2.00 Dimethicone 0.50 1.00 2.00 Cyclomethicone 2.00 4.50 0.50 Dimethicone/vinyl 4.00 0.50 dimethicone crosspolymer PVP eicosene copolymer 0.50 0.50 1.00 1.00 Glycerol 3.00 7.50 7.50 5.00 2.50 Xanthan gum 0.15 0.05 0.30 Butylene glycol 5.00 7.00 Vitamin E Acetate 0.5 0.25 0.50 0.75 1.00 Alpha-glucosylrutin 0.25 0.20 0.25 Fucogel ® 1000 1.50 5.00 DMDM hydantoin 0.60 0.40 0.20 Iodopropyl butylcarbamate 0.12 0.10 Methylparaben 0.15 0.25 0.50 Phenoxyethanol 1.00 0.40 0.40 0.50 0.60 EDTA 0.20 0.35 0.50 0.02 0.03 Ethanol 2.00 1.50 3.00 5.00 1.00 Perfume 0.20 0.20 0.30 0.40 Water ad ad ad ad ad ad ad 100 100 100 100 100 100 100
[0212] 2. Foam-Like O/W Emulsions:
Emulsion 1 Emulsion 2 % % % % by wt. by vol. by wt. by vol. Stearic acid 5.00 1.00 Cetyl alcohol 5.50 Cetylstearyl alcohol 2.00 PEG-40 stearate 8.50 PEG-20 stearate 1.00 Caprylic/capric 4.00 2.00 triglycerides C12-15 Alkyl benzoate 10.00 15.50 Cyclomethicone 4.00 Dimethicone 0.50 Octyl isostearate 5.00 Myristyl myristate 2.00 Ceresine 1.50 Glycerol 3.00 UVASorb ® K2A 2.00 4.00 Methylenebisbenzotriazolyl 0.45 tetramethylbutylphenol Drometrizole trisiloxane 1.50 2.00 Terephthalidenedicamphor 0.50 sulfonic acid Ethylhexyl 5.00 4.00 methoxycinnamate Ethylhexyltriazone 3.00 Octocrylene 5.00 Titanium dioxide 1.00 Uvinul T 805 BHT 0.02 Na 2 H 2 EDTA 0.50 0.10 Perfume, preservative, q.s. q.s. Dyes, etc. q.s. q.s. Potassium hydroxide q.s. q.s. Water ad 100.00 ad 100.00 pH adjusted pH adjusted to 6.5-7.5 to 5.0-6.0 Emulsion 1 70 Emulsion 2 35 Gas (nitrogen) 30 Gas (helium) 65
[0213] Combining of the fatty/light-protective filter phase heated to 78° C. with the water/light-protective filter phase heated to 75° C. Homogenization using a toothed-wheel dispersing machine (rotor-stator principle) at 65° C. Stirring for 45 min in the Becomix with gassing with helium at 1 bar with cooling to 30° C. Addition of the additives at 30° C. (perfume). Homogenization by means of a toothed-wheel dispersing machine (rotor-stator principle) at 23° C.
[0214] 3. PIT Emulsions (For Use as Impregnation Solution, Spray or Aerosol)
1 2 3 4 5 6 7 8 Glycerol monostearate SE 0.50 2.00 3.00 5.00 0.50 4.00 Glyceryl isostearate 3.50 4.00 2.00 Isoceteth-20 0.50 2.00 Ceteareth-12 5.00 1.00 3.50 Ceteareth-20 2.00 2.50 3.00 PEG-100 stearate 5.00 1.00 0.50 Cetyl alcohol 2.50 1.00 1.50 0.50 1.50 Cetyl palmitate 0.50 1.00 Lauryl methicone copolyol 1.00 0.75 Polyglyceryl-2 dipolyhydroxystearate 0.75 0.25 UVASorb ® K2A 1.50 2.00 2.00 3.00 5.00 3.00 1.00 3.50 Drometrizole trisiloxane 3.00 0.25 2.00 1.00 0.50 3.00 4.00 1.00 Disodium phenyldibenzimidazoletetrasulfonate 2.00 2.00 Terephthalidenedicamphorsulfonic 0.50 1.00 acid Butylmethoxydibenzoylmethane 1.00 2.00 0.75 Ethylhexyl 8.00 4.50 5.00 10.00 methoxycinnamate Diethylhexylbutamidotriazone 1.00 1.50 Ethylhexyltriazone 2.00 2.00 2.00 3.00 Octocrylene 5.00 10.00 7.50 C12-15 Alkyl benzoate 3.50 Cocoglycerides 3.00 3.00 3.50 Dicaprylyl ether 4.00 2.00 Butylene glycol 4.00 dicaprylate/dicaprate Dicaprylyl carbonate 5.00 6.00 Cyclomethicone 2.00 6.00 PVP hexadecene copolymer 1.00 1.50 0.50 Glycerol 10.0 5.00 7.50 10.00 Vitamin E acetate 1.00 0.75 0.50 1.00 2,6-Diethylhexyl naphthalate 4.00 3.50 0.50 Iodopropyl butylcarbamate 0.12 0.20 DMDM hydantoin 0.10 0.05 Methylparaben 0.50 0.45 Phenoxyethanol 0.50 0.40 1.00 1.00 Ethylhexyloxyglycerol 0.30 1.00 0.35 Ethanol 5.00 7.50 4.00 Dyes, water-soluble 0.02 0.01 Trisodium EDTA 0.14 0.20 0.50 Perfume 0.20 0.20 0.20 0.45 0.20 Water ad ad ad ad ad ad ad ad 100 100 100 100 100 100 100 100
[0215] 4. Low Viscosity to Sprayable W/O Emulsions (For Use as Impregnation Solution, Spray or Aerosol)
1 2 3 4 5 Cetyl dimethicone copolyol 4.00 2.50 3.00 Polyglyceryl-2 3.00 dipolyhydroxystearate PEG-30 dipolyhydroxystearate 2.00 0.75 0.30 Lauryl methicone copolyol 3.00 2.00 Polysorbate-21 2.00 1.50 PEG-40 stearate 1.00 1.20 0.70 Cetyl phosphate 0.25 1.00 Dimethicone 4.00 2.00 Cyclomethicone 12.00 10.00 30.00 15.00 UVASorb ® K2A 2.00 1.50 3.00 0.50 5.00 Drometrizole trisiloxane 3.00 1.50 1.00 0.50 Methylenebisbenzotriazolyl 0.25 1.00 tetramethylbutylphenol Uvinul ® A Plus 0.25 Disodium phenyldibenzimidazoletetrasulfonate 1.50 2.00 Ethylhexyl methoxycinnamate 3.00 4.00 10.00 Ethylhexyl salicylate 5.00 3.50 Octocrylene 5.00 4.00 Diethylhexylbutamidotriazone 1.00 6.50 Ethylhexyltriazone 3.00 4.00 Titanium dioxide MT-100 TV 0.50 1.00 1.50 0.50 Zinc oxide Z-Cote HP1 2.00 4.00 Dicaprylyl carbonate 5.00 15.00 4.00 Dihexyl carbonate 10.00 C12-15 Alkyl benzoate 7.00 10.00 Mineral oil 10.00 6.00 Cocoglycerides 2.00 5.00 PVP eicosene copolymer 0.75 0.40 Glycerol 5.00 7.00 α-Glucosylrutin 0.15 EDTA 0.15 0.03 0.15 Glycine soya 0.75 1.50 Magnesium sulfate 0.75 1.00 0.45 1.00 DMDM hydantoin 0.05 0.10 Phenoxyethanol 1.00 0.75 0.50 1.00 Ethanol 2.00 5.00 1.00 Dye, oil-soluble 0.02 Perfume 0.30 0.45 0.35 0.15 Water ad 100 ad 100 ad 100 ad 100 ad 100
[0216] 5. W/O Sunscreen Emulsions (Creams and Lotions)
1 2 3 4 5 Cetyldimethicone copolyol 2.00 4.00 Polyglyceryl-2 5.00 4.50 4.50 dipolyhydroxystearate PEG-30 dipolyhydroxystearate 5.00 2.00 UVASorb ® K2A 3.50 2.00 1.50 4.00 0.25 Drometrizole trisiloxane 2.00 0.75 3.00 0.25 4.00 Phenylbenzimidazolesulfonic acid 4.00 2.00 0.25 Disodium phenyldibenzimidazoletetrasulfonate 2.00 Ethylhexyl methoxycinnamate 8.00 5.00 4.00 Diethylhexylbutamidotriazone 3.00 1.00 3.00 Ethylhexyltriazone 3.00 4.00 Octocrylene 7.00 8.00 2.50 Titanium dioxide Uvinul ® T 805 2.00 1.00 Titanium dioxide MT-100 TV 3.00 2.00 Zinc oxide Z-Cote ® HP1 2.50 6.00 Mineral oil 10.0 8.00 Cocoglycerides 4.00 6.50 C12-15 Alkyl benzoates 9.00 Dicaprylyl ether 10.00 7.00 Butylene glycol 2.00 8.00 4.00 dicaprylate/dicaprate Cyclomethicone 2.00 2.00 PVP eicosene copolymer 0.50 1.50 1.00 Trisodium EDTA 1.00 0.35 Ethylhexyloxyglycerol 0.30 1.00 0.50 Glycerol 3.00 7.50 7.50 2.50 Butylene glycol 10.00 6.50 Glycine soya 1.00 1.50 MgSO 4 1.00 0.50 0.50 Vitamin E 0.50 0.25 1.00 DMDM hydantoin 0.60 0.20 Methylparaben 0.50 0.15 Phenoxyethanol 0.50 0.40 1.00 0.60 Dihydroxyacetone 5.50 Ethanol 3.00 4.50 1.00 Perfume 0.20 0.20 0.20 Water ad 100 ad 100 ad 100 ad 100 ad 100
[0217] 6. Hydrodispersions (For Use as Lotion, Impregnation Solution or Spray)
1 2 3 4 5 PEG-40 stearate 1.25 Cetyl alcohol 2.00 Sodium carbomer 0.20 0.30 Acrylates/C10-30 alkyl acrylate 0.40 0.10 0.10 crosspolymer Xanthan gum 0.50 0.30 0.15 0.50 Dimethicone/vinyldimethicone 5.00 3.00 crosspolymer UVASorb ® K2A 2.00 1.50 4.00 3.50 0.50 Methylenebisbenzotriazolyl 1.00 tetramethylbutylphenol Drometrizole trisiloxane 2.00 0.75 3.00 0.25 4.00 Uvinul ® A Plus 0.25 Bisethylhexyloxyphenol methoxyphenyltriazine 0.25 Terephthalidenedicamphorsulfonic 0.50 acid Disodium phenyldibenzimidazoletetrasulfonate 0.75 1.00 Ethylhexyl methoxycinnamate 4.00 5.00 8.00 Diethylhexylbutamidotriazone 2.00 Ethylhexyltriazone 4.00 4.00 Octocrylene 4.00 10.00 2.50 Titanium dioxide MT-100 Z 0.50 2.00 3.00 1.00 C12-15 Alkyl benzoates 2.00 2.50 Butylene glycol 4.00 6.00 dicaprylate/dicaprate Dicaprylyl carbonate 3.00 Cyclomethicone 7.50 Lanolin 0.35 PVP hexadecene copolymer 0.50 0.50 1.00 Ethylhexyloxyglycerol 0.50 1.00 0.50 Glycerol 3.00 7.50 7.50 2.50 Glycine soya 1.50 1.00 Vitamin E acetate 0.50 0.20 0.25 0.75 1.00 Fucogel ® 1000 0.30 0.25 Trisodium EDTA 0.30 0.10 0.20 Konkaben LMB ® 0.20 0.15 Methylparaben 0.50 0.15 Phenoxyethanol 0.50 1.00 0.60 Ethanol 3.00 7.00 3.50 1.00 Perfume 0.20 0.20 0.40 0.20 Dyes, water-soluble 0.02 Water ad 100 ad 100 ad 100 ad 100 ad 100
[0218] 7. Solids-Stabilized Emulsions
1 2 3 4 5 Mineral oil 16.00 16.00 Octyldodecanol 9.00 9.00 5.00 Caprylic/capric triglyceride 9.00 9.00 6.00 C12-15-Alkyl benzoates 5.00 8.00 Butylene glycol 8.00 dicaprylate/dicaprate Dicaprylyl ether 9.00 4.00 Dicaprylyl carbonate 9.00 Hydroxyoctacosanyl 2.00 2.00 2.00 2.00 1.50 hydroxystearate Disteardimonium hectorite 1.00 0.750 0.50 0.50 0.25 Cera Microcristallina + Paraffinum 2.50 5.00 Liquidum Hydroxypropylmethylcellulose 0.15 0.05 Dimethicone 4.50 UVASorb ® K2A 2.00 5.00 3.00 1.50 1.00 Drometrizole trisiloxane 2.00 0.75 3.00 0.25 4.00 Phenylbenzimidazolesulfonic acid 2.00 0.50 Ethylhexyl methoxycinnamate 6.00 3.0 Octocrylene 3.50 7.50 Ethylhexyl salicylate 3.50 4.00 Diethylhexylbutamidotriazone 4.0 Titanium dioxide Eusolex ® T-2000 2.00 4.00 2.00 4.00 Silica dimethyl silylate 1.00 Boron nitride 4.00 3.00 Tapioca starch 1.00 Sodium chloride 1.00 1.00 1.00 1.00 Glycerol 5.0 10.0 6.00 10.0 Trisodium EDTA 1.00 1.00 Methylparaben 0.21 0.20 Propylparaben 0.07 Phenoxyethanol 0.50 0.40 0.40 0.50 Hexamidine diisethionate 0.08 Diazolidinylurea 0.28 0.28 Alcohol 5.00 2.50 Perfume 0.45 0.20 0.45 Water ad 100 ad 100 ad 100 ad 100 ad 100
[0219] 8. Oils and Oil Gels
1 2 3 4 5 Octyldodecanol 9.00 9.00 Caprylic/capric triglyceride 9.00 6.00 C12-15-Alkyl benzoates 5.00 8.00 Butylene glycol 9.00 8.00 dicaprylate/dicaprate Dicaprylyl ether 9.00 4.00 Dicaprylyl carbonate 7.00 Ethyl galactomannan (N-Hance ® 3.50 4.00 AG 200) C20-40 fatty acids + polyethylenes 3.60 (Performacid ® 350) Hydroxyoctacosanyl 2.00 hydroxystearate Disteardimonium hectorite 1.00 1.00 Cetyl dimethicone 0.50 4.50 Cyclomethicones 15.00 5.00 UVASorb ® K2A 2.00 5.00 3.00 1.50 1.00 Drometrizole trisiloxane 0.75 2.00 1.85 3.00 0.50 Butylmethoxydibenzoylmethane 1.00 2.00 Ethylhexyl methoxycinnamate 6.00 10.00 3.0 Octocrylene 3.50 7.50 10.00 Ethyihexyl salicylate 3.50 4.00 Ethylhexyltriazone 2.00 Diethylhexylbutamidotriazone 0.50 3.00 4.0 Phenoxyethanol 0.50 2,6-Diethyihexyl naphthalate 5.00 4.50 5.00 Perfume 0.45 0.20 0.45 0.45 Dyes, oil-soluble 0.015 0.025 Mineral oil ad 100 ad 100 ad 100 Rice oil ad 100 ad 100
[0220] 9. Sunscreen Sticks (For Lips and/or Face)
1 2 3 4 Caprylic/capric triglyceride 12.00 10 6 Octyldodecanol 7.00 14 8 3 Butylene glycol 12 dicaprylate/dicaprate Pentaerythrityl tetraisostearate 10.00 6 8 7 Polyglyceryl-3 diisostearate 2.50 Bisdiglyceryl polyacyl adipate-2 9.00 8.00 10.00 8.00 Cetearyl alcohol 8.00 11.00 9.00 7.00 Myristyl myristate 3.50 3.00 4.00 3.00 Beeswax 5.00 5.00 6.00 6.00 Cera carnauba 1.50 2.00 2.00 1.50 Cera Alba 0.50 0.50 0.50 C16-40-Alkyl stearates 2.50 1.50 1.50 UVASorb ® K2A 2.00 4.50 3.00 0.50 Drometrizole trisiloxane 1.00 2.00 4.00 Methylenebisbenzotriazolyl 1.00 4.00 tetramethylbutylphenol Ethylhexyltriazone 2.00 Diethylhexylbutamidotriazone 3.00 Z-Cote ® HP1 4.50 MT-100 TV 4.00 2.50 Titanium dioxide T 805 3.60 5.00 Ethylhexyl methoxycinnamate 3.00 3.60 2.50 Octocrylene 7.50 Benzophenone-3 3.50 Tocopheryl acetate 0.50 1.00 Ascorbyl palmitate 0.05 0.05 Buxus Chinensis 2.00 1.00 1.00 Perfume, BHT 0.10 0.25 0.35 Ricinus Communis ad ad 100 ad 100 ad 100 100 | The invention is a light-protective cosmetic or dermatological preparation, comprising (a) at least benzotriazole and (b) at least one benzoxazole derivative. The invention is also a cosmetic or dermatological preparation comprising at least one benzotriazole from a select group and at least one benzoxazole derivative of a specified chemical structure. The invention is also a method of treating or preventing cosmetic or dermatological changes in the skin, a method of tanning or accelerating tanning of the skin, and a method of protecting the skin against light-induced aging, each comprising applying the preparation to the skin. The invention also includes a wipe impregnated with the preparation. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and hereby claims priority to International Application No. PCT/EP2012/061078 filed on Jun. 12, 2012 and German Application No. 10 2011 077 819.5 filed on Jun. 20, 2011, the contents of which are hereby incorporated by reference.
BACKGROUND
[0002] The present invention relates to a method for carbon dioxide reduction during the production of steel and also to a suitable arrangement with a steelworks.
[0003] During the production of steel, large amounts of coal and coke are expended. When fossil fuels are combusted, carbon dioxide is formed and up to now has been exported from steelworks into the ambient air in many cases. It is known that these emissions increasingly lead to an environmental and climatic problem.
[0004] A known approach for reducing carbon dioxide emission is so-called CCS routes (Carbon Dioxide Capture and Storage) which lead to the sequestration of highly concentrated carbon dioxide. During the sequestration, highly concentrated carbon dioxide is stored in underground chambers. In order to obtain highly concentrated carbon dioxide of a purity of approximately 98% or higher from steelworks off-gases, this is separated therefrom by gas-scrubbing processes.
[0005] In this case, the emission is indeed avoided, or at least reduced, but new carbon is still continuously introduced into the blast-furnace process and additional carbon dioxide is constantly produced and reemitted or has to be separated and stored.
SUMMARY
[0006] It one potential object to provide a method and a system with which the carbon dioxide emission of a steelworks can be reduced and a carbon dioxide sequestration can be avoided.
[0007] The inventors propose a method in which the carbon dioxide emission during the production of steel is reduced. The carbon dioxide which is formed in the steel production process is converted in this method in a combustion step with an electropositive metal. At least a first combustion product is formed in this case and resupplied to the steel production process. This method, therefore, compared with previously known methods for avoiding carbon dioxide emission, such as sequestration, has the advantage that it chemically reconverts the environmentally harmful carbon dioxide, and at least one product, which can be reused in the same process, is formed at the same time.
[0008] In an advantageous embodiment, the method for carbon dioxide reduction comprises a combustion step with an electropositive metal, in which an exothermic reaction with the electropositive metal takes place, generating thermal energy which can be used in power plant technology. This thermal energy can therefore be converted into electric energy or it is supplied to the steel production process. This has the advantage that in addition to avoiding carbon dioxide emission, electric energy can be generated, or the consumption of electric energy in the steel production process can be reduced.
[0009] For utilizing the thermal energy for generating electric energy, the method can be coupled to a method for generating electric energy. To this end, the steelworks is especially arranged with a power plant. This has the advantage that the thermal energy is not lost.
[0010] If the method is combined with a method for generating electric energy in which the thermal energy which is generated in the combustion step and can be used in power plant technology is converted into electric energy, the method has the further advantage of ensuring an almost complete utilization of secondary and waste products of, for example, the electric energy generation.
[0011] If the thermal energy, which in particular becomes free in the combustion step with an exothermic reaction of the electropositive metal, is to be supplied to a step for generating electric energy, a heat transport, for example, is carried out. The utilization process, taken separately, already generates energy in the form of high-temperature heat in the combustion step which can be utilized for generating electric energy, for example via a steam turbine. The utilization process is advantageously connected via the heat transport to a process for generating electric energy.
[0012] If alternatively the thermal energy is to be supplied to the steel production process, this can be used for air preheating, for example, in the blast furnace process. This process is called blast heating. The so-called blast in the blast furnace process is delivered in counterflow to the stock column into the metallurgical reactor of the blast furnace, which benefits the reaction, i.e. the combustion of the carbon from the coke.
[0013] This embodiment therefore has the advantage that in addition to the reutilization of the carbon dioxide additional energy can be generated and used in the same steel production process.
[0014] In an advantageous embodiment of the method, the electropositive metal is a metal of the first main group or a metal of the second main group, or a metal with a normal potential which is smaller than 0 V. The electropositive metal is especially lithium. Alternative electropositive metals are sodium, magnesium or zinc. Alternatively, electropositive metals such as potassium, calcium, strontium or barium can also be used. The globally available quantity of lithium is indeed limited, but a shortage only has to be reckoned with in about 40 years from now. The described method is not necessarily intended to completely cover the entire global energy demand for steel production via the alkali metal lithium. The electropositive metal which is used, however, is especially cycled, i.e. after the combustion step the combustion products of the metal are fed back into the metal. That is to say, no consumption of the electropositive metal takes place in effect. The annual production of lithium, for instance, today lies at 20,000 t, without reprocessing of the unexploited lithium taking place to date. The global reserves of lithium carbonate are estimated at 58 million tons, which corresponds to 11 million tons of lithium. The natural resources of sodium and magnesium, for instance, are subject to practically almost no occurrence limitation.
[0015] In a further advantageous embodiment, in the method the first combustion product is at least partially fed back into the steel production process. This first combustion product comprises especially carbon monoxide. This is used in the steel production process for reducing iron oxide.
[0016] In the combustion step of the electropositive metal with carbon dioxide, these reaction partners react exothermically. In addition to generating thermal energy, the reaction also yields different combustion products. The reaction is especially conducted so that at the end carbon monoxide is formed as a combustion product. During the combustion step of the electropositive metal with the carbon dioxide, oxides and carbonates of the electropositive metal accumulate as waste products. The carbon dioxide can be reduced by electropositive metals, culminating in carbon. The carbon which is formed in the combustion chamber can, however, in accordance with a Boudouard equilibrium, comproportionate with further carbon dioxide into carbon monoxide, so that at the end carbon dioxide is formally reduced to carbon monoxide by the electropositive metal. The forming of carbon monoxide in this combustion step has the advantage that the carbon monoxide plays an important role in the steel production process and can be resupplied to this. That is to say, a cycle of carbon dioxide and carbon monoxide can be created in this way. Therefore, the carbon can be retained in the system and the emission of carbon dioxide can be prevented.
[0017] In a further advantageous embodiment of the method, the first combustion product, which especially features carbon monoxide, is supplied to a blast furnace process of the steel production process. There, the carbon monoxide replaces some of the fuel which is used in the blast furnace process. Coal and/or coke are, or is, especially used as fuel. The coal or the coke in the blast furnace process also serves for the mechanical stabilization of the stock column in order to ensure a sufficiently large contact area between the solid iron ore and the reducing gas atmosphere. In this process step, some of the coal or the coke in the blast furnace is now therefore replaced by the recirculated carbon monoxide. Owing to the fact that only some of the coal or the coke is replaced, the mechanical integrity of the process remains risk free. At the same time, however, a good part of the carbon dioxide converted into carbon monoxide can be reused here. The amount of cycled carbon defines the required amount of electropositive metal by which the conversion of carbon dioxide into carbon monoxide first of all takes place. The smaller the amount of carbon which is to be converted, the smaller the required amount of this electropositive metal too.
[0018] In an alternative advantageous embodiment of the method, the blast furnace process is replaced by a direct reduction process in the steel production process. In this case, the first combustion product, i.e. especially the carbon monoxide, is used as reducing gas. In particular, the pure carbon monoxide or the carbon monoxide in a mixture with hydrogen is used as reducing gas. That is to say, in this direct reduction process the coal or the coke can be replaced completely by the recycled carbon monoxide. In a direct reduction process, finely ground iron ore, for example, is exposed to a flow of reducing gas in counterflow in a fluidized bed reactor and converted in the process. This method has, for example, the advantage that additional fossil fuels are no longer used, rather these can be replaced completely by the carbon monoxide from the carbon cycle.
[0019] The carbon cycle offers the advantage of being able to realize a steelworks which is free of CO 2 emission. In addition, the process of carbon dioxide recycling can be connected to the process for electric power generation by a power plant.
[0020] If the generated carbon monoxide is not kept totally within the cycle, the carbon monoxide proportion which is not fed back into the steel production process can, for example, be converted into a further usable end product, such as methanol.
[0021] In a further advantageous embodiment, a second combustion product, which is electrochemically reconvertible and which is converted in a reconversion process, is formed in the combustion step of the method. For this reconversion process and the electrochemical reaction which is vital for it, energy is required. For this, especially a regenerative energy source can be used. The second combustion product is especially an oxide and/or a salt of the electropositive metal. If the electropositive metal is lithium, Li 2 O, Li 2 C 2 and Li 2 CO 3 , for example, it is formed as a combustion product. That is to say, CO 2 can especially be separated out as lithium carbonate from a flue gas flow in this way. This oxide or salt of the electropositive metal can be converted again into the metal in the reconversion process. The metal itself is therefore not consumed in the process, rather only the oxidation step is changed. Therefore, the metal can also be seen as an energy store. Since the reconversion, i.e. the electrochemical conversion, is independent of the steel production process in respect of time, regenerative energies, such a photovoltaic energy or wind energy, can be used for this reconversion process. The method therefore has the added advantage, in addition to reducing carbon dioxide emission, of coupling a store for regenerative energies to the steel production process. The use of an electropositive metal as an energy store also has the advantage, for transmission over longer distances, of being superior to previous energy transmissions, e.g. by transmission lines.
[0022] In principle, the carbon dioxide could also be reduced by hydrogen instead of with an electropositive metal. The use of hydrogen, however, is effective only when this is also directly converted at the site of generation. Under standard conditions of 25° C. and 1013 mbar, 1 mole of hydrogen occupies a volume of 24.5 L, whereas 2 moles of lithium occupy only a volume of 0.025 L. The formation enthalpies in relation to the mass for lithium oxide and water are comparable:
[0000] Li 2 O: −20 kJ/g
[0000] H 2 O: −16 kJ/g
[0023] As a result, the metallic lithium has an energy density which is more than 1000 times higher in comparison to the gaseous hydrogen. Hydrogen can be compressed or liquefied, admittedly, but its effective energy density with regard to normal conditions is considerably reduced as a result, however. Moreover, the lithium can be transported much more easily than hydrogen can.
[0024] Such a reprocessing of the converted electropositive metal therefore forms a second cycle which, via the combustion reaction, is coupled to the carbon dioxide-carbon monoxide cycle. Such a reprocessing of the electropositive metal can be an electrochemical reduction, for example. In this case, especially oxides, hydroxides or salts of the electropositive metal can be reconverted into the metal. In general, an electrochemical reduction of the metal ions Mn+ can lead back to the metal M. Again, electric energy, which can be produced from regenerative energy, for example, is required for this. Such a reprocessing or reconversion process of the electropositive metal can especially be seen as an energy store for energy which is produced from photovoltaics. Particularly advantageous, therefore, is especially the conducting of a reconversion process for electropositive metals which are subjected to a natural occurrence limitation, such as lithium.
[0025] The reconversion process can take place separately from the steelworks process-spatially and temporally.
[0026] For the described steelworks process, a steelworks with a combustion chamber, which comprises an electropositive metal, is expediently arranged. In this case, the combustion chamber serves for combusting the electropositive metal. The combustion chamber is preferably designed so that the electropositive metal and carbon dioxide can be introduced into the combustion chamber and so that a combustion step can be carried out therein with an exothermic reaction of the electropositive metal.
[0027] The combustion chamber is especially designed so that the reaction can be conducted in such a way that carbon monoxide is formed at the end. In principle, during the exothermic reaction of the electropositive metal with the carbon dioxide, carbon can also be produced. This, however, can additionally comproportionate to carbon monoxide via the Boudouard equilibrium.
[0028] The steelworks system proposed by the inventors comprises a combustion chamber, however, which is designed for converting carbon dioxide, which is formed in the steel production process, with an electropositive metal in a combustion step.
[0029] In this case, the combustion chamber is designed so that an electropositive metal can be introduced into the combustion chamber and at least a first combustion product can be exported from the combustion chamber and fed back into a device of the steelworks. This has the advantage that not only the environmentally harmful carbon dioxide is processed and chemically reconverted but that at the same time it also directly forms a product which is required for the steel production process and can be made available again to this.
[0030] In an advantageous embodiment of this arrangement, the device of steelworks is a blast furnace or alternatively a fluidized bed reactor. The corresponding processes, which were run in the blast furnace or in the fluidized bed reactor, have already been described in the method. In the blast furnace, a so-called stock column is exposed to a flow of hot air in counterflow and only some of the recycled carbon monoxide is added to this method for reducing the iron oxide. In the fluidized bed reactor, a direct reduction process takes place, in which process the synthesis gas includes only the fed-back carbon monoxide from the first combustion product.
[0031] In a further advantageous embodiment, the arrangement with the steelworks comprises a recycling device. This recycling device is designed for the electrochemical reconversion of an oxide and/or of a salt of an electropositive metal. This combination with the recycling device has the advantage that the electropositive metal which is converted in the combustion step can be directly recovered. In contrast to carbon dioxide, which cannot be simply split again into carbon and oxygen by electric energy, the situation with the electropositive metal is such that by an electrochemical process the oxide can be reconverted into oxygen and the electropositive metal. It is also the situation with the salts of the electropositive metal.
[0032] By way of example, the reactions for lithium oxide are specified in the following.
[0000] 2Li+O2→2Li2O+mechanical, chemical, electric energy
[0000] 2Li2O+electric energy→2Li+O2
[0033] Therefore, lithium serves as an energy carrier and store and can therefore be cycled without being consumed. This aspect is known from printed publication DE 10 2008 031 437 A1, for example.
[0034] The recycling device can especially draw the electric energy which is required for the reconversion from a regenerative energy source. This therefore has the advantage that by an energy store, such as lithium, renewable energies can be integrated into the steelworks process. Lithium lies, for instance, sufficiently high up a thermodynamic energy scale in this case so that it can strongly exothermically react not only in air, but also in pure nitrogen, hydrogen and carbon dioxide, which enables conversion of the carbon dioxide.
[0035] Furthermore, the energy which is produced as a result of the exothermic reaction can also be used in power plant technology. That is to say, the waste heat temperature is high enough for this to be able to be used for generating electric energy.
[0036] Alternatively, the thermal energy remains in the steel production process. For this, the arrangement especially comprises a heat transporting device via which the combustion chamber is connected to the steelworks so that thermal energy, which is produced in the combustion chamber as a result of the combustion step and can be used in power plant technology, can be transported and supplied to the steel production process. The heat can be used in the steel production process, especially in the blast furnace process for blast heating.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawing of which:
[0038] The figure schematically shows the arrangement of a steelworks 30 , 40 with a recycling device 20 for reconversion of the electropositive metal M with a plant for producing electric energy 10 from the wind and/or sun.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawing, wherein like reference numerals refer to like elements throughout.
[0040] The figure schematically shows the arrangement of a steelworks 30 , 40 with a recycling device 20 for reconversion of the electropositive metal M with a plant for producing electric energy 10 from the wind and/or sun. On the left-hand side of the drawing, a wind-powered turbine wheel and the sun are symbolically depicted for the regenerative energy source 10 . From this regenerative energy source 10 , electric current 11 is transported to the recycling device 20 . In the recycling device 20 , the reduction of an electropositive metal M from an oxide or a salt MO x takes place. This reduction process is especially carried out electrochemically. The energy which is required for this is drawn from the regenerative energy source 10 . Leading away from the recycling device 20 is an arrow which represents a product of the recycling device 20 , specifically the electropositive metal M. Leading towards the recycling device 20 is an arrow which represents the introduction of a salt or oxide MOx of the electropositive metal M which is to be converted. The electropositive metal M serves as an energy store 21 , so-to-speak. This is represented symbolically by a cylindrical tank 21 , into which an arrow leads. Leading away from this cylindrical tank 21 as an energy store is an arrow 22 which illustrates the transporting path to the steelworks 30 , 40 . The electropositive metal M in its function as an energy store 21 can admittedly also be formed in a recycling device 20 directly at the steelworks 30 , 40 , but transporting 22 of the metal M is also conceivable since this is significantly more effective and more loss-free to realize than the transporting of comparable energy stores such as hydrogen, or in comparison to electric current transporting via transmission lines.
[0041] A combustion chamber 30 and also a further device of the steelworks 40 are then schematically shown, in which the following processes take place:
[0042] In the combustion chamber 30 , the carbon dioxide conversion with the electropositive metal M takes place. By an arrow which leads into the combustion chamber 30 and leads away from the combustion chamber 30 , it is shown that the carbon dioxide CO 2 can be introduced into the combustion chamber 30 and carbon monoxide CO leaves the combustion chamber 30 . Also, the arrow with the oxide or salt of the electropositive metal MO x , which leads into the recycling device 20 , leads away from this combustion chamber 30 .
[0043] Shown in addition to the combustion chamber 30 is the device 40 of the steelworks into which the carbon monoxide CO is fed again and from which the carbon dioxide CO 2 is separated out. The process in which the carbon monoxide CO reacts to form carbon dioxide CO 2 therefore takes place in this device. This occurs when reducing iron oxides, as is undertaken in the processing of iron ores for steel production. The device 40 can represent the blast furnace of the steelworks, in which some of the carbon monoxide CO is reused together with further fossil fuels. The device 40 , however, can also represent a fluidized bed reactor in which a direct reduction process uses up the entire carbon monoxide CO as reducing gas. According to this, no new carbon is introduced into the system but the carbon is fully cycled between these two devices of the combustion chamber 30 and the fluidized bed reactor 40 . The figure illustrates that in addition to the carbon cycle, an additional cycle, specifically the cycle of the electropositive metal M, can be coupled to the steelworks process.
[0044] The combustion in the combustion chamber 30 is especially to be conducted so that the end product is carbon monoxide:
[0000] 2Li+CO 2 →Li 2 O+CO.
[0045] The resulting carbon monoxide CO can be used in the blast furnace 40 of the steelworks directly for reducing the iron oxide. In this case, it is reconverted into carbon dioxide CO 2 .
[0046] This is resupplied to the combustion chamber 30 where it can react with an electropositive metal M, especially lithium. As a result, the carbon is therefore cycled. This consequently circulating part of the carbon no longer leaves the steelworks 30 , 40 and leads to reduced CO 2 emissions.
[0047] A further advantage of the carbon dioxide conversion with the electropositive metal lies in the fact that during the combustion step in the combustion chamber 30 energy in the form of high-temperature heat is generated and can be used for generating electric energy. The combustion chamber 30 is therefore preferably coupled to a power plant. In this case, the energy, in the form of high-temperature heat, which is generated in the combustion step in the combustion chamber 30 can additionally be supplied to the power plant, especially to the steam generator in the power plant, and can serve for generating electric energy.
[0048] Especially if the present aims for generating regenerative electric energy continue to be successful in this way, sufficient energy can be provided from these sources in the near future to economically and ecologically realize the described cycle. Since this electric energy is generated at a point in time at which it cannot be consumed or completely consumed, it is important that this can be temporarily or even seasonally intermediately stored. The described recycling of an electropositive metal M, especially lithium, fulfills this criteria on such a completely reusable energy carrier 21 .
[0049] The blast furnace of a steelworks 40 emits about 1.3 million tons of carbon dioxide per year, with a production capacity of 4 million tons per year of steel. For the rereduction of 10% of this carbon dioxide CO 2 to carbon monoxide CO would require 42,000 tons of lithium per year. The lithium in this case is not consumed in one pass but is kept in a cycle in which it is regenerated again. Depending upon the cycle duration, only a fraction of the aforementioned lithium quantity would therefore be generally required. If, for example, the lithium were to carry out the cycle 10×/year, only 4200 tons of lithium would be consumed in the cycle for a reduction of 10% of the carbon dioxide output.
[0050] The invention has been described in detail with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention covered by the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 69 USPQ2d 1865 (Fed. Cir. 2004). | A method reduces carbon dioxide resulting from a steel production process. The carbon dioxide is reacted with an electropositive metal in combustion to produce carbon monoxide. The resultant carbon monoxide is fed back into the steel production process. In this method, the carbon monoxide can be used in a direct reduction method as a reduction gas or can be fed to a blast furnace process. The reacted metal can also be recovered by electrochemical conversion from its oxides or salts. In particular, a form of regenerative energy can be used to recycle the electropositive metal. | 8 |
This application claims the benefit of priority under 35 U.S.C. §119(e) from U.S. Provisional Patent Application Ser. No. 60/820,714, filed Jul. 28, 2006, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to crystalline erlotinib, including anhydrous as well as hydrated forms, processes for preparing them, pharmaceutical compositions thereof and their use in preparing erlotinib or pharmaceutical acceptable salts of erlotinib.
Erlotinib, chemically [6,7-bis(2-methoxyethoxy)-quinazolin-4-yl]-(3-ethynylphenyl)amine of formula 1
is a compound that inhibits the human epidermal growth factor receptor tyrosine kinase, also known as EGFR-TK, that is critical for growth of malignant cells. EGFR overexpression is associated with disease progression, and reduced survival. Erlotinib acts by blocking tyrosine kinase activity of EGFR-TK, resulting in inhibition of signaling pathway, and decreased growth of malignant tumors. Erlotinib is thus useful for the treatment of proliferative disorders such as cancers in humans. Erlotinib is marketed as its hydrochloride salt under such brand names as TARCEVA® (OSI Pharmaceuticals, Inc.) for treatment of certain lung cancers and pancreatic cancer.
WO 96/30347 and U.S. Pat. No. 5,747,498 teach quinazoline derivatives for treating hyperproliferative diseases such as cancers. Example 20 shows the formation of erlotinib free base and the subsequent conversion to the hydrochloride salt. Before the conversion to the salt, an organic phase containing the erlotinib was concentrated and the residue flash chromatographed on silica to obtain the free base as a pale yellow solid. This solid was then dissolved in a solvent and reacted with HCl to form the hydrochloride salt. There is no report of whether the solid erlotinib was crystalline.
European patent application EP 1044969 discloses processes for making erlotinib, its salts, and related compounds. Several examples make the hydrochloride salt (see examples 4, 7 and 9-11) and several make the mesylate salt (see examples 8 and 12). No mention is made in the examples of forming a solid erlotinib free base. Rather the solid forms are obtained by precipitation of the erlotinib salts.
Several patent publications disclose the existence of polymorphic forms of erlotinib salts. For example, WO 01/34574 discloses the existence of two polymorphic Forms of erlotinib hydrochloride which were designated as Form A and B. Form B is thermodynamically more stable than Form A. More recently WO 2004/072049 discloses the existence of another polymorph of erlotinib hydrochloride, designated as Form E, which is thought to have similar stability as Form B but with a higher solubility. The mesylate salt of erlotinib, with enhanced solubility compared to the hydrochloride, and its preparation is disclosed in WO 99/55683. Anhydrous erlotinib mesylate exists in three different polymorphic Forms designated Form A, B and C. Also a monohydrate of erlotinib mesylate and its use in the preparation of anhydrous mesylate Forms is disclosed.
While crystalline salts of erlotinib have been studied, it would be advantageous to be able to provide erlotinib in a solid, crystalline form.
SUMMARY OF THE INVENTION
The present invention is based on the discovery that erlotinib free base can be formed as a crystalline solid material and, more particularly, to the discovery of three specific crystalline forms. Accordingly, a first aspect of the invention relates to crystalline erlotinib free base which is substantially Form I, Form II, or Form III. The crystalline erlotinib can be an anhydrous crystal or a hydrated crystal. The crystalline erlotinib can be a stable solid material suitable for making a pharmaceutical dosage form and is thus also useful for treating hyperproliferative diseases such as cancer. Alternatively, the crystalline erlotinib can be useful in forming salts of erlotinib. For example, crystalline erlotinib free base according to the invention can be precipitated from a solution and then converted to a pharmaceutically acceptable salt such as the aforementioned hydrochloride or methanesulfonate salts. The formation of the crystalline free base can provide a useful pathway for purifying erlotinib or an erlotinib salt.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a representative XRPD pattern of erlotinib free base Form II.
FIG. 1B is a representative DSC spectra of erlotinib free base Form II.
FIG. 1C is a representative FT-IR spectra of erlotinib free base Form II.
FIG. 2A is a representative XRPD pattern of erlotinib monohydrate Form I.
FIG. 2B is a representative DSC spectra of erlotinib monohydrate Form I.
FIG. 2C is a representative FT-IR spectra of erlotinib monohydrate Form I.
FIG. 3A is a representative XRPD pattern of erlotinib monohydrate Form III.
FIG. 3B is a representative DSC spectra of erlotinib monohydrate Form III.
FIG. 3C is a representative FT-IR spectra of erlotinib monohydrate Form III.
FIG. 4 is a XRPD pattern of the product of the Comparative Example
The XRPD patterns were recorded according to the following settings:
Start angle (2θ):
2.0°
End angle (2θ):
35.0-50°
Scan step width:
0.02°
Scan step time:
between 1-6 seconds
Radiation type:
Cu
Radiation wavelengths:
1.54060 Å (Kα 1 ),
primary monochromator used
Exit slit:
6.0 mm
Focus slit:
2 mm
Divergence slit:
Variable (V20)
Antiscatter slit:
3.37 or 6.17 mm
Receiving slit:
5.25 or 10.39 mm
The DSC spectra were obtained according to the temperature schedule given below and the samples were measured in an aluminum pan with a pierced lit:
Start temperature:
25° C.
End temperature:
260° C.
Heating rate:
10° C./min
The FT-IR spectra were obtained according to the KBr-method. The FT-IR spectra were recorded from 600 cm −1 to 4000 cm −1 . From each FT-IR spectrum a blank FT-IR spectrum of KBr was subtracted. That blank IR spectrum was recorded prior to the measurements of the samples.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to the discovery of crystalline Forms of erlotinib free base. As used herein, “crystalline erlotinib” and “crystalline erlotinib free base” are used broadly to include solvates/hydrates of erlotinib as well as anhydrous forms. The crystal need not be morphologically pure but does substantially comprise one of the Forms I, II, or III. Thus the erlotinib crystalline material is “substantially” one of the Forms I, II, or III, e.g., one Form accounts for at least 80%, more typically at least 85%, and usually at least 90% of the crystalline erlotinib. A “pure” Form is substantially free of any other crystalline Forms having less than 5%, typically less than 2%, and more preferably no XRPD-detectable amount of any other crystal Form. While none of the above-mentioned prior art describes a crystalline erlotinib free base, it appears that Example 20 of WO 96/30347 may be capable of producing a type of crystalline erlotinib free base. As shown in the Comparative Example hereinafter, a similar experiment to the Example produced a material having some crystallinity as demonstrated by the XRPD shown in FIG. 4 . The material has several strong peaks below 10° 2θ and may have a significant amorphous content. The crystalline portion of the material is either a different crystal From than Forms I, II and III of the present invention or is a mixture of forms; in the latter event, the crystalline erlotinib is not substantially one of Forms I, II, or III. Being able to reliably form a solid, crystalline form of erlotinib can provide useful ways of administering erlotinib. Additionally, the crystallization of the free base can serve as a useful purification step for the erlotinib base or a salt thereof, e.g., using crystalline erlotinib as the starting material for the salt formation reaction.
In general, the crystalline erlotinib free base Forms of the present invention can be formed by crystallizing erlotinib from an erlotinib solution. The solvent is generally an alcohol such as methanol, ethanol or isopropanol; acetone; acetonitrile, chloroform; 1,4-dioxane; toluene; or a mixture of two or more of these solvents. The crystallization can be induced/caused by cooling and/or adding a contrasolvent such as water or an alkane such as heptane. Other crystallization techniques may also be used, including reducing the volume of the solution by evaporation, and/or seeding.
Three specific crystalline forms have been found useful and are designated Forms I, II, and III, respectively. Forms I and III are hydrates while Form II is an anhydrate. The three forms, beginning with the anhydrous Form II, are hereafter described in more detail.
Crystalline erlotinib free base Form II of the present invention is an anhydrous crystalline form. It can generally be identified or distinguished from other erlotinib crystalline forms by the following characteristic XRPD peaks at 2θ: 6.4, 12.8, 15.6, 18.2, 22.3, 23.2, 23.6, and 25.8+/−0.2 degrees, and/or FT-IR peaks v max (KBr) cm −1 : 772, 851, 1033, 1131, 1218, 1256, 1334, 1430, 1502, 1576, 1619, and 3251+/−4 cm −1 . As used herein, the +/−0.2 degrees for the XRPD peaks and the 4 cm −1 for the FT-IR peaks applies to each peak listed, respectively. Also, the listed peaks for each Form are not intended to represent an exhaustive list. Generally crystalline Form II erlotinib, in a relatively pure state, has an XRPD that substantially corresponds to FIG. 1A and/or an FT-IR that substantially corresponds to FIG. 1C . The expression “substantially corresponds” means that a pattern or spectra does not have to be superimposable over the recited figure but rather can have minor variations of the type caused by differences in sample preparation, conditions of measurement, purity of the sample to other compounds, polymorphic purity, etc., as understood by a worker skilled in the art. For example, the increase or decrease in a peak in an FT-IR spectrum corresponding to the presence of the amount of carbon dioxide gas would not indicate a different crystalline form, even though the spectra would not be superimposable.
The DSC scan of Form II shows a melting peak around 154-158° C. TGA shows only little mass loss below 180° C. Form II may be present as needles or thin plates.
When Form II is melted and cooled, no recrystallization takes place, regardless of the cooling rate or rate upon reheating. While not entirely clear, probably a stable glass is formed that does not recrystallize. Another explanation may be degradation.
XRPD under non-ambient conditions (30° C./10-90% RH and 50° C./75% RH) showed that Form II does not undergo polymorphic transitions under humid conditions at elevated temperatures. TGA confirmed that Form II can be considered non-hygroscopic.
Erlotinib base Form II can be formed by precipitating from a solution. Typically the solvent is an alcohol, especially isopropanol, or acetone. Co-solvents such as ethanol or toluene may also be present. The presence of water is generally avoided in the solution. Specific techniques include:
(i) (re)crystallization of erlotinib base from an alcoholic solvent, typically from 2-propanol; or (ii) precipitation by adding n-heptane to a solution of erlotinib in acetone at room temperature (R.T.).
Recrystallization from 2-propanol may initially give Form II with a small amount of another Form. However, prolonged stirring results in pure Form II. This indicates that Form II is the thermodynamically more stable Form.
Mixtures of Form I and Form II were obtained by recrystallization from ethanol, toluene, 2-propanol/n-heptane (1:10 V/V), or by adding a solution of erlotinib in 2-propanol to n-heptane at 0° C. Such mixtures may be recrystallized to yield pure Form II by processes a) or b) above, if desired. Pure Form II should be understood as substantially free of any other crystalline Forms of erlotinib.
Crystalline Form I is a monohydrated form of erlotinib free base that can generally be identified by the following characteristic XRPD peaks at 2θ: 7.4, 10.9, 14.6, 14.9, 18.3, 20.1, 20.5, 20.8, 22.4, 24.6, 27.6, 30.0, and 30.3+/−0.2 degrees, and/or FT-IR peaks; vmax (KBr) cm − : 791, 883, 897, 1030, 1128, 1208, 1243, 1293, 1429, 1482, 1533, 1629, and 3569+/−4 cm −1 . Generally a relatively pure crystalline Form I erlotinib has an XRPD that substantially corresponds to FIG. 2A and/or an FT-IR that substantially corresponds to FIG. 2C . As used herein a “monohydrate” means that the crystalline material contains approximately 1 mole of water for each mole of erlotinib. It can vary typically by up to about 15% from a perfect 1:1 ratio. As is well known in the art, this water is bound to the crystal lattice and is not simply a wet material.
A DSC scan of Form I shows a complex evaporation endotherm below 145 C with an embedded (melting) peak around 126-129° C. Melting can be observed around 155-157° C. TGA shows evaporation of about 1 equivalent of water below 140-170° C. The crystals are well defined prisms and bars.
Crystalline Form III is a monohydrated Form of erlotinib free base that can generally be identified by the following characteristic XRPD peaks at 2θ: 6.8, 13.1, 14.7, 20.4, 21.1, and 24.5+/−0.2 degrees and/or FT-IR peaks; vmax (KBr) cm −1 : 871, 1118, 1131, 1212, 1249, 1434, 1517, 1536, 1629, 3274, and 3536+/−4 cm −1 . Generally relatively pure crystalline Form III erlotinib has an XRPD that substantially corresponds to FIG. 3A and/or an FT-IR that substantially corresponds to FIG. 3C .
A DSC scan of Form III shows overlapping evaporation effects and melting around 154-156° C. TGA clearly showed a single step, corresponding to about 1 equivalent of water. Form III may be present as rectangular or square-like thin plates.
The hydrated crystalline erlotinib free base may be crystallized from a solvent comprising water. Preferably a water/ethanol/acetone mixture (2:1:1 V/V/V) at ambient temperature may be used which results in the hydrated Form I, preferably in pure Form I. Pure Form I should be understood as substantially free of any other crystalline forms of erlotinib. Pure Form III can be obtained by crystallizing from acetone/water (3:10 V/V) at ambient temperature. Pure Form III should be understood as substantially free of any other crystalline form of erlotinib.
The starting erlotinib used to prepare the crystalline erlotinib free base of the invention, can be obtained by any suitable or known means. The erlotinib can be obtained as an oil, an amorphous solid or as a crystalline material (such as a mixture of crystalline Forms) directly from the erlotinib synthesis and then dissolved into an appropriate solvent for (re)crystallization. Alternatively, the erlotinib free base can be liberated from an acid salt of erlotinib such as a hydrochloric acid or methanesulfonic acid salt of erlotinib, under aqueous basic conditions followed by an extraction of the free base with a water immiscible organic solvent, for instance ethyl acetate. The free base can be recovered as an oil or solid and then, if necessary, dissolved into a suitable solvent for (re)crystallization
The hydrates of the invention can be converted into anhydrous forms and vice versa. For instance, any of the hydrates provides for the erlotinib free base Form II by heating.
The transition of hydrate Form I into Form II proceeds via melting of Form I after which the melt recrystallizes to Form II. The transition of Form III into Form II occurs via the solid-solid transformation. Form II appears to be the thermodynamically most stable form.
Another way to convert the hydrates to Form II includes recrystallization in a suitable solvent, preferably with some provision for removing water; e.g. by a Dean-Stark trap. Suitable solvents are for instance 2-propanol, chloroform, 1,4-dioxane, and mixtures thereof. Seeding can be used to speed up the crystallization rate.
Crystalline Forms I, II, and III are stable crystalline Forms which make them suitable for formulation of pharmaceutical compositions and for handling and storage, either individually or in combinations, e.g. a mixture of crystalline forms. Form II is generally considered the preferred form for making a pharmaceutical dosage form.
The invention also relates to the use of crystalline erlotinib free base, especially Form I, II, and/or III and their pharmaceutical compositions as a medicament. Generally the compound is used for the treatment of a hyperproliferative disease, especially a cancer. Specific cancers include brain, squamous cell, bladder, gastric, pancreatic, hepatic, glioblastoma multiform, head, neck, esophageal, prostate, colorectal, lung especially non-small cell lung cancer (NSCLC), renal, kidney, ovarian, gynecological, thyroid, and refractory cancers. Suitable dosage regimens comprise from 0.001 to 100 mg/kg/day.
The pharmaceutical composition can be in the form for enteral, parenteral or transdermal administration. The composition can be administered orally in the form of tablets, capsules, solutions, suspensions or emulsions. The composition can also be administered in the form of an injection solution or suspension or infusion solution, or transdermally with for instance a patch. Pharmaceutical compositions can be obtained in a way which is common for a person skilled in the art.
The compositions comprise a crystalline erlotinib and at least one pharmaceutically acceptable excipient. Finished dosage forms, such as tablets or capsules, generally contain at least a therapeutically effective amount of crystalline erlotinib and a suitable carrier.
Suitable carriers are for instance solid inert diluents or fillers or liquids such as water, alcohols, etc. Examples of common types of carriers/diluents include various polymers, waxes, calcium phosphates, sugars, etc. Polymers include cellulose and cellulose derivatives such as HPMC, hydroxypropyl cellulose, hydroxyethyl cellulose, microcrystalline cellulose, carboxymethylcellulose, sodium carboxymethylcellulose, calcium carboxymethylcellulose, and ethylcellulose; polyvinylpyrrolidones; polyethylenoxides; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; and polyacrylic acids including their copolymers and crosslinked polymers thereof, e.g., Carbopol® (B.F. Goodrich), Eudragit® (Rohm), polycarbophil, and chitosan polymers. Waxes include white beeswax, microcrystalline wax, carnauba wax, hydrogenated castor oil, glyceryl behenate, glycerylpalmito stearate, and saturated polyglycolized glycerate. Calcium phosphates include dibasic calcium phosphate, anhydrous dibasic calcium phosphate, and tribasic calcium phosphate. Sugars include simple sugars, such as lactose, maltose, mannitol, fructose, sorbitol, saccharose, xylitol, isomaltose, and glucose, as well as complex sugars (polysaccharides), such as maltodextrin, amylodextrin, starches, and modified starches.
Furthermore the compositions may contain additional additives including stabilizers, preservatives, flavoring agents, colorants, lubricants, emulsifiers or other additives which will be apparent for the skilled persons in the art of preparing pharmaceutical compositions.
Crystalline erlotinib free base can also be used for the synthesis of a pharmaceutical acceptable salt of erlotinib. The compound may react in a solvent with an organic or inorganic acid followed by isolation of the pharmaceutical acceptable salt of erlotinib, generally by precipitation from the reaction mixture.
Suitable organic acids are methanesulfonic acid, naphthalene sulfonic acid, maleic acid, acetic acid, malic acid, fumaric acid, and citric acid. Suitable inorganic acids are hydrobromic and hydrochloric acid. Preferably the acid is methanesulfonic acid or hydrochloric acid. The salts of erlotinib may be obtained in anhydrous, hydrated or solvated forms. Preferably the erlotinib salts are obtained in solid form. More preferably the erlotinib salts are obtained in crystalline form.
The following examples are illustrative to the present invention. They are not intended to limit the scope of the invention in any manner.
EXAMPLES
Example 1
Erlotinib Form II
0.2 g of erlotinib monohydrate Form I was dissolved in 5 ml of 2-propanol at reflux. The solution was allowed to cool to R.T. and stirred at R.T. for about 19 hours; crystallization already occurred within the first hour of stirring. The solid was isolated by filtration over a P3-glass filter (reduced pressure) and air dried at R.T. and under ambient conditions for a few hours. An off-white powder with a yield of 140 mg was obtained. (analytical data in FIGS. 1A , 1 B, and 1 C)
Example II
Erlotinib Monohydrate Form I
3.0 g of erlotinib hydrochloride was suspended in 400 ml of demi-water/ethyl acetate (1:1 V/V) at R.T. To the suspension/emulsion, vigorously stirred at R.T., 300 mg of NaOH dissolved in 50 ml of demi-water was added very slowly (dropwise, >1 equivalent of OH − ). As a result of this, the HCl was removed from the drug substance and the drug substance was extracted into the organic phase. Some extra NaOH was added as the water-layer proved to be hardly basic afterwards and to ensure complete removal of HCl from the drug substance. The organic phase was twice washed with water and filtered over a P3-glass filter (reduced pressure), packed with prewashed Celite 545. The filtrate was dried with sodium sulphate for 15-30 minutes. The solution was filtered over a P3-glass filter (reduced pressure) to remove the sodium sulphate. Then, the solvent was evaporated under vacuum to dryness, yielding a pale beige, crystalline solid with a yield of approximately 1.85 g. (analytical data in FIGS. 2A , 2 B, and 2 C)
Example 3
Erlotinib Monohydrate Form III
0.2 g of erlotinib was dissolved in 15 ml of acetone at R.T. The solution was filtered over a P3-glass filter (reduced pressure) to remove foreign particles. To the clear filtrate, stirred at R.T., 50 ml of demi-water was added dropwise. During addition of water, fast crystallization occurred. The suspension was stirred at R.T. for about 2 minutes. The solid was isolated by filtration over a P3-glass filter (reduced pressure) and air dried overnight at R.T. and under ambient conditions. An off-white, fluffy to foamy powder mass was obtained. The yield was 150 mg. (analytical data in FIGS. 3A , 3 B, and 3 C)
Example 4
Erlotinib Monohydrate Form I
0.2 g of erlotinib form II was mixed together with 20 ml of demi-water. The suspension was refluxed, but the drug substance did not dissolve. To the hot suspension, 10 ml of ethanol was added, but no clear solution was obtained upon reflux. 10 ml of acetone was added to the suspension. After additional reflux, a clear solution was obtained. The solution was allowed to cool to R.T. and stirred at R.T. for about 23 hours; crystallization occurred. The suspension was stirred for a few minutes at 0° C. The solid was isolated by filtration over a P3-glass filter (reduced pressure) and air dried at R.T. and under ambient conditions for about 3 days. An off-white, nicely flowable powder of small and shiny crystals was obtained. The yield was 160 mg.
Example 5
Erlotinib Form II
1.5 g of erlotinib hydrochloride was suspended in 100 ml of demi-water/dichloromethane (1:1 V/V) at R.T. To the suspension/emulsion, vigorously stirred at R.T., 300 mg of NaOH dissolved in about 10 ml of demi-water was added slowly. As a result of this, the HCl was removed from the drug substance and the drug substance was extracted into the organic phase. Some extra 1M NaOH (few ml) and 50 ml of dichloromethane were added as extraction appeared to be far incomplete (solid material remained in the water phase).
After vigorous stirring at R.T. for 1 hour, both liquid layers appeared to be more or less clear. The organic layer was separated. Possible remaining drug substance in the water phase was extracted with an additional 50 ml of dichloromethane. The combined organic phases were filtered over a P3-glass filter (reduced pressure, packed with Celite 545), washed with 50 ml of fresh demi-water and filtered over the same filter again. The clear filtrate was dried with sodium sulphate for 1.5 hours (stirring). The solution was filtered over a P3-glass filter (reduced pressure) to remove the sodium sulphate. Then, the solvent was slowly evaporated under vacuum to dryness, yielding an off-white to pale beige, crystalline solid. No yield was determined.
Example 6
0.2 g of erlotinib monohydrate Form I was dissolved in 10 ml of acetone at R.T. and by means of stirring. To the solution, 150 μl of 2-propanol with 5-6 N HCl was added (>1 equivalent of HCl), while stirring was continued. As a result of this, immediate precipitation took place. The suspension was stirred at R.T. for an additional few minutes. The solid was isolated by filtration over a P3-glass filter (reduced pressure, rapid) and air dried overnight at R.T. and under ambient conditions. Lumps of off-white, sticky powder were obtained. The yield was 150 mg.
Erlotinib hydrochloride was obtained as a mixture of Form A and Form B.
Comparative Example
Based on Example 20 of WO 96/30347
37 mg of 3-ethynylaniline and 90 mg of 4-chloro-6,7-bis-(2-methoxy-ethoxy)quinazoline were added to a mixture of 1.5 ml of isopropanol and 25 μl pyridine. The resulting mixture was refluxed for 4 hours under an atmosphere of dry nitrogen. During reflux the color changed from pale yellow to orange-pink. The solvent was removed in vacuo on a rotavap (water bath 40° C.) The residue was partitioned between 5 ml 10% methanol in chloroform and 5 ml saturated aqueous NaHCO 3 . The organic layer was dried over Na 2 SO 4 , filtered and concentrated in vacuo. The residue was dissolved in a mixture of 2.5 ml of acetone and 2.5 ml hexane and flash chromatographed on silica using 30% acetone in hexane, concentrated in vacuo on a rotavap (water bath 40° C.) About 90 mg of a sticky pale yellow solid was obtained (attached to the wall of the flask) The solid was analyzed on XRPD and the results shown in FIG. 4 .
Each of the patents, patent applications, and journal articles mentioned above are incorporated herein by reference. The invention having been described it will be obvious that the same may be varied in many ways and all such modifications are contemplated as being within the scope of the invention as defined by the following claims. | Crystalline Forms of erlotinib are made. The crystalline materials are useful as pharmaceutical active agents in treating various cancers as well as in forming erlotinib salts. | 2 |
This is a national stage of PCT/US2006/045375 filed Nov. 24, 2006 and published in English, claiming benefit of U.S. provisional application No. 60/739,943, filed Nov. 28, 2005.
FIELD OF THE INVENTION
The present invention generally relates to an apparatus and process which can provide careful regulation of the thermal, shear, and rheological components of materials in a pelletization process. The materials being pelletized are prepared or formulated in a mixing device such as a vessel or extruder and subsequently processed through a heat exchanger and extruder to achieve the proper temperature for that pelletization without detrimental phase separation or die freeze off and which provides uniform pellet geometries and acceptably low pellet moisture levels. The apparatus and method of this invention has application for narrow-range melting compounds, high melt flow formulations, low melting temperature materials, and polymeric mixtures, formulations, dispersions, or solutions of which waxes, asphalts, adhesives including hot melt adhesives, high melt flow polyolefins including polypropylenes and copolymers, and gum base formulations are exemplary.
DESCRIPTION OF RELATED PRIOR ART
Pelletization of materials and particularly polymeric materials has been well-known in the art for many years and has been integral to the operations of the assignee of the present invention from as early as U.S. Pat. No. 4,123,207 issued Oct. 31, 1978. Processing polymeric materials through heat exchangers and extruders have similar early histories in the literature and have been used in association with pelletizers in various arrangements throughout that period. Processing pellets through centrifugal dryers to obtain suitably low moisture pellets is readily established in the literature and has been instrumental to the present assignee from as early as U.S. Pat. No. 3,458,045 issued Jul. 29, 1969. Modifications and improvements of these processes have been demonstrated through subsequent issuance of U.S. Pat. Nos. 4,251,198 (Feb. 17, 1981), 4,447,325 (May 8, 1984), 4,500,271 (Feb. 19, 1985), 4,565,015 (Jan. 21, 1986), 4,728,276 (Mar. 1, 1988), 5,059,103 (Oct. 22, 1991), 5,265,347 (Nov. 30, 1993), 5,638,606 (Jun. 17, 1997), 6,237,244 (May 29, 2001), 6,739,457 (May 25, 2004), 6,793,473 (Sep. 21, 2004), and 6,807,748 (Oct. 26, 2004) owned by the assignee of the present invention and included herein by way of reference exemplarily in whole or in part.
The following additional patents and published patent applications are relevant to the present invention:
U.S. patents
RE36,177
4,617,227
5,019,610
5,298,263
5,482,722
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5,987,852
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6,150,439
6,358,621
6,713,540
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U.S. Published Patent Applications
2005/101702 2005/191325
Pelletization of polymeric materials has proven particularly successful for a wide range of material types where rapid cooling quickly solidifies at least the outermost layer or layers of the pellet formed allowing them to be propagated to a dryer or to further processing. There are numerous materials which suffer from qualities which do not lend themselves readily to these processes. Exemplary of these qualities are very narrow melting ranges, low temperature melting ranges, low viscosity of molten or semi-solid materials, slow thermal conductivity and therefore slow ability to cool rapidly enough for processing, proclivity to undergo phase separation on cooling, surface tack, poor miscibility of liquids during blending processes, and extreme temperature variance from the mixing/blending stage to the extrusion/pelletization stage. Materials which typically exhibit the foregoing properties and, therefore, have heretofore not lent themselves to pelletization technologies include, for example, waxes, asphalts, adhesives, gum base formulations, high melt-flow polyolefins, and non-polymeric organic and/or inorganic compounds. Hence, there is a need in the art for an apparatus and process which can successfully pelletize these challenging materials and applications, especially when using underwater pelletizers to form the pellets.
SUMMARY OF THE INVENTION
The material, or materials, to be pelletized in accordance with the present invention are charged into a vessel or an extruder to be melted, sheared, and/or mixed. The vessel may be at atmospheric pressure, pressurized, or under vacuum and may be unpurged or purged with air or an inert gas such as nitrogen, argon, or the like. Pressure, vacuum, and purging may be applied sequentially or continuously in any combination and order. The requisite energy converts the formulation to a molten or semi-solid mixture or liquid which flows suitably by gravity or under pressure when released in batch processing or continuous flow processing. The applied energy may be thermal and/or mechanical in the form of low, medium, or high shear as necessitated by the formulation requirements which directly and significantly impacts the temperature of the molten, semi-solid or liquid material.
The material mixed or blended in the vessel, once released, optionally may flow into and through a booster pump and/or is pressurized sufficiently to flow through a coarse filter apparatus as required. The material from the vessel, pressurized and/or filtered as required, or alternately from an extruder, then flows through a diverter valve which allows the material to flow toward a heat exchanger or melt cooler or otherwise recirculate back to the vessel or extruder, or may be purged or discharged from the system. Pressure is induced on the melt flow by a melt pump with discharge into the melt cooler for significant temperature reduction. Additional mixing may be achieved wherein baffles are within the melt cooler. Cooling by the heat exchanger may be sufficient to allow some crystallization or phase separation within the melt. Alternatively, the diverter valve may be placed after the melt cooler rather than as described above with similar capabilities as described therein.
In accordance with the present invention, the material to be pelletized, after exiting from the melt cooler or heat exchanger, is fed to a cooling extruder. The cooling extruder provides for more efficient mixing while at the same time providing additional and controlled cooling of the molten, semi-solid mixture or liquid material. The combination of the melt cooler and the cooling extruder surprisingly allows for pre-cooling of the molten material which reduces the total energy, including the thermal energy, contained within that material more effectively than can be achieved by an extruder operating alone.
The cooling extruder optionally allows purging, devolatilization, or addition of other chemicals or materials inclusive of which may be impurities, by-products, degradation products, volatiles or thermally sensitive components as required by or as a consequence of the formulation and processing. Control of the cooling temperature and thorough mixing during the melt cooler and cooling extruder sequence are necessary to insure uniform homogeneity of the material or mixture being processed and to reduce the temperature to, or near to, that at which pelletization occurs. This lowering of the temperature serves to reduce or eliminate the likelihood that phase separation or die freeze-off will result during extrusion/pelletization.
The molten, semi-solid mixture or liquid material or materials leaving the cooling extruder continues through the processing or may be discharged out of the system through the diverter valve. Continuation of the flow proceeds toward the pelletization unit and passes through a melt pump to pressurize the flow sufficient to pass optionally through a secondary melt cooler or directly into the pelletization unit. Additionally, a melt pump may be necessary following the secondary melt cooler to insure adequate pressurization for the extrusional pelletization.
The pressurized melt proceeds through the thermally regulated die toward the water box of the underwater pelletizer or other equivalent pelletization unit known to those skilled in the art. The uniformly dispersed fluid material passes through the die and is cut by rotating blades in the pelletizing unit. Water which is thermally controlled removes the pellets from the cutter blade and transports them through the agglomerate catcher for removal of coarsely aggregated or agglomerated pellets, through the dewatering device, and into the centrifugal dryer or fluidized bed to remove excipient surface moisture from the pellets.
The pellets may pass through the pellet discharge chute either for collection or may proceed to additional processing including pellet coating, crystallization, or further cooling as required to achieve the desired product. As is readily understood by those skilled in the art, coating, enhanced crystallization, cooling operations, or other processing appropriate to the pelletized material may be performed after pelletization and before introduction of the pellet into the drying process as well.
While the additional extruder added to the pre-pelletizing processing of the polymer or other material to be pelletized in accordance with the present invention has been called a “cooling extruder”, those skilled in the art will readily understand that any known or available extruder can be used as the cooling extruder. The cooling extruder, therefore, may be a single, twin, or multiple screw design, or a ring extruder for example. The cooling extruder is preferably a single screw and more preferably a twin screw.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing illustrating a first conventional mixing vessel, pelletizer, and centrifugal dryer.
FIG. 2 is a schematic drawing illustrating a second conventional extruder, pelletizer and centrifugal dryer.
FIG. 3 is a schematic drawing illustrating a sequentially arranged mixing vessel, melt cooler, pelletizer and centrifugal dryer known in the prior art.
FIG. 4 is a schematic drawing illustrating a first embodiment of the present invention with sequentially arranged mixing vessel, filtration, melt cooling, extrusional dispersion and cooling, pelletizer and centrifugal dryer.
FIG. 5 is a schematic drawing illustrating a second embodiment of the present invention with sequentially arranged extrusional mixing, filtration, melt cooling, extrusional dispersion and cooling, pelletization, and centrifugal dryer.
FIG. 6 is a schematic drawing illustrating a third embodiment of the present invention with sequentially arranged optional mixing vessel or mixing extruder, filtration, melt cooler, extruder for dispersion and cooling, optional additional melt cooling, pelletizer, and centrifugal dryer.
DETAILED DESCRIPTION OF THE INVENTION
Although preferred embodiments of the invention are explained in detail, it is to be understood that other embodiments are possible. Accordingly, it is not intended that the invention is to be limited in its scope to the details of constructions, and arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, in describing the preferred embodiments, specific terminology will be resorted to for the sake of clarity. It is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. Where possible, components of the drawings that are alike are identified by the same reference numbers.
Referring specifically to the drawings, FIG. 1 illustrates a basic prior art system including a mixing vessel, pelletizer, and centrifugal dryer. Material or component materials to be pelletized are fed into the thermally regulated mixer or blender, generally designated by reference numeral 10 , manually as a solid or liquid, or by a feed screw 12 , pump, or similar device through or attached to the vessel orifice 14 . The vessel chamber 16 may be atmospheric or purged with air or an inert gas, preferably nitrogen or argon. Liquids may be drawn into the chamber 16 by siphoning with a partial vacuum. This may be useful for reactive or moisture-sensitive components. Components may be added in portions with mixing and warming to temperature as required. Mixing is achieved by rotation of the rotor 18 by motor 20 . Attached to the rotor are mixing blades 22 exemplary of which may be propeller or boat style, ploughshare style, delta or sigma style in single, double or multiple configurations, and helical or helical dispersion blades. Alternatively the mixer may be a ribbon blender, Banbury-type blender, horizontal mixer, vertical mixer, planetary mixer or equivalent device known to those skilled in the art.
Various levels of mixing and shear are achieved by the differing styles of blades and mixer designs. Higher shear blades are preferred for components such as rubbers or cross linkable rubbers and thermally sensitive polymers. Energy is introduced into the polymer and resultant mixture mechanically by the shear, as well as thermally by any conventional physical heating process. Propeller style blades are more preferred for physical mixing where less or no shear is required to achieve uniformity of blending. Heating of the vessel (and its contents) may be achieved electrically, by steam, or by circulation of hot liquids such as oil or water. Mixing or blending continues until the batch reaches an appropriate temperature or other criterion of consistency determined or known specifically for the process.
On reaching the appropriate pour point, valve 24 is opened and the molten, semi-solid mixture or liquid material or materials (hereinafter sometimes collectively “the melt”) passes into the pipe 26 and is drawn into the booster pump 30 . The booster pump 30 may be a centrifugal or positive displacement reciprocating or rotary pump, and preferably is a rotary pump which may be a peristaltic, vane, screw, lobe, progressive cavity, or gear pump, and more preferably is a gear pump. The gear pump may be high precision, or even more preferably open clearance, and generates an intermediate pressure, typically up to 500 psi and preferably less than 150 psi. The pump pressure is sufficient to force the melt through the coarse filter 35 which is preferably a candle filter, basket filter, or screen changer, and is more preferably a basket filter of 20 mesh or coarser. The coarse filter 35 removes larger particles, agglomerates, or granular material from the melt as it flows through the pipe 32 to and through melt pump 40 which generates pressures on the melt, preferably at least 200 psi and more preferably from 500 psi to 2000 psi. The melt pump 40 may be a centrifugal or positive displacement reciprocating or rotary pump, and preferably is a rotary pump which may be a peristaltic, vane, screw, lobe, progressive cavity, or gear pump, and more preferably is a gear pump. Seals must be compatible with the material being processed, chemically and mechanically, the details of which are well understood by those skilled in the art.
The pressurized melt passes through a second filter 45 which is preferably a basket filter or screen changer, and is more preferably a screen changer of 200 mesh or coarser, and even more preferably a multilayer screen changer of two or more screens of differing mesh, most preferably a series of filters exemplary of which is 20 mesh, 40 mesh, and 80 mesh. The screen changer may be manual, plate, slide plate, single or dual bolt, and may be continuous or discontinuous. The melt passes into and through the diverter valve 60 wherein the melt may be diverted to waste, to a recycle stream back to the vessel 16 , or may continue to the extrusion die 65 . Pressure generated by the melt pump 40 must be sufficient to force the melt through the screen changer 45 , the diverter valve 60 and through the die plate 65 without allowing the melt to cool and potentially freeze off the die openings in the die plate 65 . The extrusion die contains a multiplicity of orifices of number and geometry appropriate to the flow rate, throughput, and melt material as is known to those skilled in the art.
Pelletization of the melt is achieved by an underwater, hot face, strand, water ring or similar pelletizer, and preferably by an underwater pelletizer 70 of construction by or similar to designs marketed by Gala Industries, Inc., (Eagle Rock, Va.), the assignee of the present invention (hereinafter “Gala”). As the melt extrudes through the die plate orifices, the pelletizer motor rotates a series of blades which cut the strands of melt into small pellets. The pellets so made are conveyed out of the water box by a rapid flow of thermally controlled water provided by the pump 72 through the conduit 74 and out through the effluent pipe 78 . Alternatively, a series of valves and piping form a bypass loop 76 that allows the water to be shunted past the water box when the molten material is not being pelletized. The temperature of the water, the rotational rate of the cutter blades, and the flow rate of the melt through the die contribute to the production of proper pellet geometries. The temperature of the pellets, both in the interior and the exterior or shell, also influence the formation of the pellets as well as the drying of the pellets. The flow rate of the water through the pipe 78 should be sufficiently rapid to convey the pellets to the dryer, generally designated by reference numeral 80 , with controlled loss of heat from the pellets. The dryer 80 is preferably a centrifugal pellet dryer as manufactured by Gala.
Drying of the pellets with controlled loss of heat is achieved by passing the pellet and water slurry through an agglomerate catcher 75 which contains a round wire grid or coarse screen 82 to remove oversize chunks or agglomerates of pellets. The slurry optionally passes through a dewatering device 84 , or series of dewatering devices, containing baffles 86 and an angular feed screen 88 which collectively reduce the water content, preferably 90 percent, and more preferably 98 percent or more. The water removed passes through the fines removal screen 92 into a water tank or reservoir 90 and is available for recycling or disposal. The pellets immediately transfer to the inlet at the base of the centrifugal dryer 80 where they are lifted rotationally upward by a rotating rotor with lifters 94 and are propelled outwardly against a foraminous screen 96 , preferably a perforated plate or pierced screen, concentrically surrounding the rotor/lifter assembly 94 and contained within the housing 98 . As the pellets impact the screen, the excess surface moisture is transferred away through the screen, and the pellets bounce back multiple times while being lifted farther up the dryer toward the dried pellet chute 100 at the top of the dryer 80 . Motor 102 rotates the rotor/lifter assembly 94 and counter-current air flow is provided by blower 104 in models of centrifugal dryers marketed by Gala as previously noted. Power for all processes is provided by control system 95 . The dried pellets pass out the chute 100 for storage or may be further processed with coatings, additional crystallization, or further cooled as is well understood by those skilled in the art. The design and operation of the pelletizer and centrifugal dryer are detailed in the aforementioned patents by Gala.
Turning now to FIG. 2 , an alternative prior art embodiment is illustrated. Instead of mixing vessel 10 and related components of FIG. 1 , an extruder 200 with one or more feed units 212 is utilized to mix and heat the melt material to be pelletized. The extruder 200 optionally may be a single, twin, or multiple screw design, a ring extruder for example, and is preferably a single screw and more preferably a twin screw. The sections of the screw must feed, mix, and convey the melt material simultaneously providing sufficient energy, thermal and mechanical, to melt, mix, and uniformly disperse the melt material or materials to be pelletized. The twin screw or multiple screw is capable of being purged by air or preferably an inert gas, such as nitrogen, or may be evacuated at one or more ports to remove gases, volatiles, or impurities. Multiple feeding and injection ports may be added along the barrel of the screw as required to allow addition of ingredients, solid or liquid, to the melt in process. Configuration of the screw must be satisfactory to achieve an appropriate level of feeding, mixing, melting, blending, and throughput and is well understood by those skilled in the art.
Once the melt materials are properly admixed in the extruder 200 the melt optionally may pass through a melt pump 240 and/or a screen changer 245 comparable to melt pump 40 and screen changer 45 , respectively, as described for FIG. 1 . Pressure generated by the extruder 200 or by the extruder 200 and melt pump 240 must be sufficient to extrude the melt through the die and pelletization system which follow the equipment described for FIG. 1 . Designs illustrated in FIG. 1 and FIG. 2 require the components upstream of the extrusion die 65 in FIG. 1 and analogously in FIG. 2 to provide sufficient energy to mix, melt, and extrude the melt. Where shear is high, as is common in gum base and adhesive formulations, these same elements must not only input tremendous energy to achieve that shear but then must cool or otherwise dissipate that energy and heat prior to the extrusion through the die to avoid excessively low viscosity or excessively hot pellets which lead to extruded material wrapping around the die face by the cutter, elongated pellets, and formation of poor geometry pellets and/or pellet aggregates and agglomerates. The zones of the extruder distal from the material inlet, therefore more proximal to the extruder outlet can be adjusted to provide some of this cooling by reducing the actual temperature of the zones or sections. Designs in the configuration of FIG. 1 do not have this capability.
A present commercial design which interjects cooling into the apparatus illustrated in FIG. 1 is shown in FIG. 3 . The components described in FIG. 1 are identified with numerically the same number and fulfill all conditions and preferences of the FIG. 1 illustration. A melt cooler 250 is introduced into the process following the melt pump 40 and screen changer 45 . The melt pump 40 must generate sufficient pressure to force the melt through the melt cooler 250 and on through the extrusion die 65 and for the subsequent processing described for FIG. 1 . The melt cooler 250 is a heat exchanger of the coil type, scrape wall, plate and frame, shell and tube design with or without static mixers, or U-style tube design with or without static mixers, and preferably is a shell and tube design which includes static mixing blades within the individual tubes to further mix the material and bring more of the material in intimate contact with the wall of the tube outside of which is a flow of oil or water coolant circulating within the shell housing, preferably in a countercurrent flow pattern as is understood by those skilled in the art. The temperature and flow rate of the circulating medium is carefully regulated by a control unit, not shown. This unit is capable of reducing the temperature of the melt prepared in vessel 10 to that which will allow extrusion of the melt through the die plate 65 with reduced likelihood of wrap around the die face by the cutter, improved pellet geometry, lower pellet temperature, and less aggregation and agglomeration of the pellets.
Limitations of the FIG. 2 and the FIG. 3 embodiments remain problematic in that cooling, though present, does not have a level of control and narrowness of definition of degree in temperature to acceptably be able to reproducibly produce high quality pellets of narrow melting range materials, such as waxes, where the liquid to solid temperature transition may be twenty degrees or less, and may be as narrow as only a few degrees. The designs illustrated in FIGS. 1-3 are further limited in their capacity to achieve sufficient dispersive mixing to eliminate phase separation of blended materials, examples of which include synthetic asphalt formulations, adhesive and hot melt adhesives, and gum bases.
Furthermore, materials of high melt flow index commonly require high shear to melt the material after which the resultant viscosity is extremely low and with limited cooling as exemplified in FIGS. 2 and 3 may still result in problematic extrusion as cited in the foregoing discussions. For these materials the temperature transition from fluid to more viscous semi-solid or solid is typically narrow and control challenges are similar in difficulty to those encountered for waxes and the like.
It is with these basic considerations and challenges that the preferred embodiments of the present invention are illustrated in FIGS. 4 , 5 , and 6 . In all cases the equipment from the die face and downstream are the same as described for FIG. 1 and have not been described again for sake of conciseness and clarity.
In consideration of FIG. 4 , the material or materials to be pelletized are charged into vessel 10 and progresses through the system analogous to that described in connection with FIG. 1 and as modified by incorporation of the melt cooler 250 as described in detail in connection with FIG. 3 . Reference numbers and process preferences remain the same as for those similarly numbered components illustrated and described in connection with the prior drawing figures. The material or materials are mixed in the mixer 10 commonly with high shear and subsequently are high in temperature as well. On release of valve 24 the melt flows through pipe 26 to booster pump 30 and is moderately pressurized to insure flow into and through the coarse filter 35 . Coarsely filtered flow proceeds through pipe 32 to melt pump 40 and is pressurized sufficiently to progress through screen changer 45 and melt cooler 250 where the temperature is reduced in accordance with the previous descriptions associated with FIGS. 1 and 3 .
To maximize the dispersive homogeneity of the melt, it passes directly into a cooling extruder 300 , which can be the same as previously described extruder 200 in connection with FIG. 2 . The screw configuration of cooling extruder 300 should provide rigorous mixing and propagation through the distal zones or sections from the inlet where the further cooling is achieved. Addition of thermally sensitive ingredients may be accomplished through one or more side feeders 310 , illustrated separately from extruder 300 to indicate the variability in positioning relative to that extruder. The side feed or side feeders 310 may provide additional solid, semi-solid or liquid materials to the mix such as rheological additives, miscibilizing agents, surfactants, expanding agents, catalysts, inhibitors, antioxidants, chain extenders, nucleation agents, flavors, fragrances, colorants, devolatilizing agents, chemical scavengers, or additives appropriate to the application and well known to those skilled in the art. On final mixing in the cooling extruder, the uniform and homogeneous melt has been cooled sufficiently for extrusional pelletization. Optionally a melt pump 340 and screen changer 345 may be positioned following the effluent orifice of the extruder 300 and prior to the inlet to the extrusion die 65 . This allows pressure to be increased as necessary to achieve appropriate pelletization of the uniformly disperse, cooled product melt. Pelletization and drying follow as described in connection with FIG. 1 . Inclusion and positioning of the booster pump 30 , coarse filter 35 , and screen changer 45 are optional.
The equipment illustrated in FIG. 5 follows that shown and described in FIG. 2 for shear mixing through the extruder 200 . One or more feeders 412 may be solid or liquid inlets to the initial extruder 400 which are similar to feeders 212 and extruder 200 , respectively, as described in connection with FIG. 2 . In the embodiment of FIG. 5 , extruder 400 is designed with screw objectives of shear mixing and melting. The melt passes through the outlet of the extruder through a diverter valve 460 , comparable to diverter valve 60 described in connection with Figure i, and then through a booster pump 440 and coarse filter 445 into the melt cooler 450 . Descriptions and preferences follow from analogous components, 40 and 45 , as well as for melt cooler 450 versus 250 , and differ only in that, although meeting the preference criteria described in connection with previous figures, they may or may not be identical to components 40 , 45 or 250 in this preferred embodiment. As shown in FIG. 5 , the cooled melt proceeds directly to the cooling extruder 300 and is processed in accordance with the description previously provided in connection with FIG. 4 . Inclusion and positioning of the diverter valve 460 , booster pump 440 , and coarse filter 445 are optional.
FIG. 6 illustrates a composite of components from the FIGS. 4 and 5 embodiments. Mixing vessel 10 and/or extruder 400 with feed 412 may serve as the shear mixer and feed through a common diverter valve 560 into a melt pump 40 and screen changer 45 . The melt proceeds through melt cooler 450 and into cooling extruder 300 and diverter 460 as previously described in connection with FIG. 5 . Diverter 560 differs only in that it must provide two inlets as well as a waste/recycle and outlet position. From the outlet of the extruder 300 and diverter 460 the material optionally may pass through a melt pump 540 and screen changer 545 into a secondary melt cooler 550 for additional regulation of the temperature of the melt and final mixing. An additional melt pump 555 optionally provides further pressurization as the melt proceeds to the extrusion die 65 and through pelletization and drying as described previously. Additional pressurizations before the screen changers and melt coolers are preferable to insure proper flow of the melt through those devices. Pressure limitations of 2000 psi are commercially common and therefore limit pressurization prior to extrusion. The addition of melt pump 555 provides additional pressurization capabilities which may be necessary to proper extrusion through the die 65 .
The illustrated embodiments reflect the use of a preferred centrifugal dryer to produce pellets with minimum surface moisture content. Pellets with high tack, high friability or brittleness, low melting or softening temperatures, or low deformation temperatures optionally may be processed through vibratory dewatering devices, fluidized beds, or other comparable devices not illustrated and well known to those skilled in the art to achieve the desired level of surface moisture. Prior to or subsequent to the drying operations alternatively, pellets may be coated, crystallized, or cooled by processes, techniques, and equipment readily available commercially.
By way of an example, a polyolefin copolymer was processed utilizing the apparatus illustrated in FIG. 4 . The temperature in mixing vessel 10 to achieve formulation was 200° F. to 600° F., preferably 200° F. to 500° F., more preferably from 200° F. to 400° F., and most preferably from 300° F. to 400° F. The pour temperature of the melt from the vessel 10 was 200° F. to 600° F., preferably 200° F. to 500° F., more preferably from 200° F. to 400° F., and most preferably from 300° F. to 400° F. On cooling and subsequent mixing the temperature of the melt after the melt cooler 250 was 100° F. to 550° F., preferably 100° F. to 450° F., more preferably from 100° F. to 350° F., and most preferably from 200° F. to 300° F. With additional cooling through the cooling extruder 300 , the temperature of the melt at the die plate 65 was reduced to 75° F. to 400° F., preferably 75° F. to 300° F., more preferably from 100° F. to 250° F., and most preferably from 150° F. to 250° F. The water temperature for the underwater pelletization was regulated at 40° F. to 200° F., preferably 40° F. to 150° F., more preferably from 40° F. to 100° F., and most preferably from 40° F. to 80° F. to insure proper pellet geometry, sufficiently low temperature for pelletization without deformation, reduced likelihood of freeze-off at the die, and to avoid wrapping the extrudate around the face of the die by rotation of the cutter.
Asphalt to be pelletized in accordance with the apparatus and method of the present invention may be naturally occurring or synthetic including, for example, formulations comprised of bitumen, plasticizers, a binder, and/or a polymeric resin base. Bitumen exemplarily may be derived from crude oil, petroleum pitch, plastic residues from distillation of coal tar, mineral waxes, bituminous schists, bituminous sands, bituminous coal, and asphalt dispersions.
Adhesives to be processed in accordance with the apparatus and method of the present invention include those containing a polymeric base or binder, tackifier, wax, fillers, additives and the like. Gum bases similarly contain a polymeric base which is capable of mastication, polymeric gum base, emulsifiers, softeners or plasticizers, texturizing agents, fillers, flavors, and fragrances. Thermally and oxidatively sensitive medicaments and medicating agents are also contained within the scope of applications for the present invention.
Polymeric bases and gum bases may include acrylonitrile-butadiene-styrene elastomers, alkyds, amorphous polyalphaolefins or APAO, atatic polypropylene, balata, butadiene rubber, chicle, crumb rubber, ethylene-acrylic acid copolymers, ethylene-cyclopentadiene copolymers, ethylene-methacrylate copolymers, ethylene-propylene-diene monomer or EPDM, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, guayule, gutta hang kang, guttapercha, halobutyl rubber, high density polyethylene or HDPE, isobutylene rubber, isobutylene-isoprene copolymeric rubber, isotactic polybutene, polypropylene, and polystyrene, jelutong gum, lechi caspi, low density polyethylene or LDPE, maleated polyolefins, massaranduba balata, massaranduba chocolate, natural or liquid latexes, natural rubber, nispero, nitrile or halonitrile rubber, oxidized polyolefins, perillo, polyacrylamides, polyacrylates, polyacrylonitriles, polyamides, polybutadiene, polycarbonates, polychloroprene, polyesters including PET and PBT, polyisoprene, polynorbornenes, polysilicates, polyurethane, polyvinylacetate or PVA or PVAc, polyvinyl alcohol, polyurea, pontianak gum, rosindinha, sorva, styrene-acrylonitrile, styrene butadiene rubber or SBR, styrene butadiene styrene or SBS, styrene ethylene butylene block copolymers, styrene ethylene propylene block copolymers, styrene-isoprene rubber or SIR, styrene-isoprene-butadiene rubber or SIBR, styrene-isoprene-styrene or SIS, vinyl acetate homopolymer, vinyl acetate-vinyl laurate copolymers, or blends thereof, by way of example. Masticatory or chewable bases may also include prolamines, gliadin, horedein, zein, or similar proteinaceous materials. Polymeric materials may be cross-linked or cross-linkable.
Tackifiers, and resins, often as plasticizers and softeners, for processing in accordance with the present invention, include hydrocarbons which are aliphatic, cycloaliphatic, and aromatic, mixed aliphatic/aromatic hydrocarbons, natural and partially hydrogenated rosin esters, natural and partially hydrogenated wood rosins, glycerol rosin esters, glycerol tall oil ester, maleic-modified rosin, pentaerythritol rosin esters, polyterpenes, terpenes, a-pinene, b-pinene, and d-limonene, phenolic modified terpenes, polyethylene grease, polyvinylacetate, mineral oils including paraffinic and naphthionic, and styrene-terpene copolymers, as well as other liquid plasticizers well known to those skilled in the art.
Waxes, individually or formulationally, which may be processed in accordance with the present invention, include beeswax, candelilla wax, carnauba, ceresin wax, China wax, Fischer-Tropsch waxes including oxidized forms, high density low molecular weight polyethylene or HDLMWPE, hydroxystearamide wax, japan wax, lardeceine, lignite wax, microcrystalline wax, ozokerite, paraffin or petroleum wax, polyethylene wax, polyolefin wax, rice bran wax, sugarcane wax, and vegetable waxes including those from canola, coconut, corn, cottonseed, crambe, linseed, palm, palm kernel, peanut, rape, or soybean.
High melt flow polymerics, for processing in accordance with the present invention, include low viscosity molten polyolefins and preferably include polypropylene and vinylic copolymers thereof including ethylene, butylene, cyclic vinylics by way of example.
Emulsifiers, colorants, fillers, flavorants, perfumants, and other additives appropriate to the formulation and known to those skilled in the art can be used as desired in accordance with the present invention.
The term “melt” as used in the claims following hereafter, and as used previously herein, is intended to encompass all extrudable forms of a material or materials, including but not limited to molten, semi-solid, mixed or liquid material or materials.
Further, it is not intended that the present invention be limited to the specific processes described herein. The foregoing is considered as illustrative only of the principles of the invention. Further, 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. | An apparatus and process maintain control of the temperature of low-melting compounds, high melt flow polymers, and thermally sensitive materials for the pelletization of such materials. The addition of a cooling extruder, and a second melt cooler if desired, in advance of the die plate provides for regulation of the thermal, shear, and rheological characteristics of narrow melting-range materials and polymeric mixtures, formulations, dispersions or solutions. The apparatus and process can then be highly regulated to produce consistent, uniform pellets of low moisture content for these otherwise difficult materials to pelletize. | 1 |
BACKGROUND OF THE INVENTION
The invention relates to a device for continuous drying of a pulp web, particularly a tissue web, with a drying drum and an air circulating system, where the drying drum has a cylindrical shell designed as a honeycombed body.
In conventional tissue plants, the drying process begins at an ingoing dryness of some 40 to 45%. In order to achieve higher paper volume, papermakers now dispense with preliminary mechanical dewatering, and the ingoing dryness of this newer type of device is around 20 to 25%. These plants operate with through-air drying. During the heating process, one or more consecutive through-air drying drums at ambient temperature are exposed abruptly to the supply air temperature of approximately 300° C. The drying drums currently in use have a thin-walled shell, for example a perforated or honeycombed body, that is joined to thick-walled end flanges. Due to the substantial differences in mass between drum shell and end flange, there is excessive stress at the transition points that leads to deformation and even structural damage. The same damage occurs if the drums are cooled down abruptly from operating to ambient temperature during an emergency shutdown, when they are sprayed with cold water in order to prevent the plastic wires enclosing the drums from being damaged.
SUMMARY OF THE INVENTION
The invention now aims to eliminate this disadvantage and is characterized by the honeycombed cylinder shell of the drying drum having an annular, flexible transition profile at the edges. Thus, any changes occurring in diameter and any resulting thermal stress can be reduced.
An advantageous further development of the invention is characterized by the transition profile being designed as a U-profile and preferably being butt-welded onto the honeycombed cylinder shell. With this design of transition piece, continuous heat transition is guaranteed during both the heating and the cooling process of the machine. The special type of joint leads to a reduction of the stresses in the welds to such extent that the welds suffer no deformation or structural damage at all.
A favorable embodiment of the invention is characterized by the cross-section of the transition profile, preferably a U-profile, narrowing towards its center. As a result, the heat flow can be influenced particularly well. In addition, this design creates a flexible connection, which also guarantees that the cylinder shell is centered and thus, runs exactly true.
It is an advantage if the honeycombed cylinder shell is wider than the paper web to be dried, thus allowing a defined variation of the paper web width.
A favorable further development of the invention is characterized by an endless ring being shrunk on at each end and which extends beyond the transition profile and into the honeycombed cylinder shell. This prevents dust or fibers from entering the cavity of the U-profile.
It has proved favorable to make the cylinder shell out of longitudinal ribs that are connected to upright, edged profiles. This achieves good stability in the cylinder shell.
A favorable embodiment of the invention is characterized by the longitudinal ribs of the honeycombed cylinder shell being spaced at a distance of between 20 and 80 mm from one another, preferably between 30 and 40 mm. If the spacing is narrower, there is also less specific load and thus, reduced risk of marks on the paper web.
An advantageous embodiment of the invention is characterized by the edged connecting profiles mounted in a honeycombed pattern protruding beyond the longitudinal ribs and supporting the paper web and the conveying wire. This results in a large supporting surface and a further reduction in the risk of marks on the paper web.
It is particularly favorable it the honeycombed cylinder shell has an open area of at least 85%. The through-air drying process can thus be implemented particularly well.
A particularly favorable further development of the invention is characterized by covers being provided on the face ends to stabilize the cylinder shell and by these covers being bolted to the cylinder shell, particularly to the transition pieces. This design guarantees improved stability of the drum shell; in particular, it prevents any sliding movement by the end cover and the drum shell if there is radial expansion caused by the temperature.
An advantageous embodiment of the invention is characterized by the drying drum having a fully welded drum body. This design virtually excludes the risk of any areas where cracks could occur.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in examples and referring to the drawings, where
FIG. 1 shows a variant of a configuration of a through-air drying unit;
FIG. 2 is a sectional view through FIG. 1 along the line marked II-II;
FIG. 3 shows a drying drum according to the invention;
FIG. 4 shows detail IV in FIG. 3 ;
FIG. 5 shows detail V in FIG. 3 ; and
FIG. 6 a sectional view along the line marked VI-VI in FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a possible configuration of a through-air drying process. The figure shows the drum 1 with its bearings 2 and 3 , and the drive 4 .
Beneath the drum there is a two-part hood 5 and 6 (see FIG. 2 ) from which the hot supply air flows through the paper web, through a conveying wire 8 , then through the drying drum 1 into the inside of the drum, and is removed from the drum on the drive side through an annular channel 10 . The hot supply air at a temperature of approximately 300° C. is cooled down to approximately 120° C. by the drying process. The exhaust air cooled in this way is then returned to its entry status in a processing system. At the outlet, the paper web 7 with the conveying wire 8 is carried over a deflection roll 11 . The cover device 12 is clearly visible here, covering the area of the drum 1 from the inside outwards in the sector that does not come into contact with the tissue web 7 and which also is not enclosed by the hood 5 and 6 . This prevents additional air from being drawn into the drying drum, which would greatly reduce the suction effect through the paper web. In principle, the air can also be conveyed from the inside of the drying drum 1 through the cylinder shell 9 to the outside.
FIG. 3 show a sectional view through a drying drum 1 , comprising a perforated, preferably honeycombed cylinder shell 9 with a flexible ring 13 rolled into a horizontal U-profile, butt-welded onto the edges of the shell on both the operator and the drive side. Due to this U-shaped transition profile 13 between cylinder shell 9 and end covers 14 , 15 , the maximum stresses in the connecting weld are reduced to approximately one third of those occurring in conventional designs, which guarantees damage-free operation of the drying drum over its entire service life.
FIG. 4 shows a sectional view of the connection between the drum shell and the flexible ring 13 , as well as the weld joint itself and the bolted connection 17 to the drum cover 14 . As viewed in section, each flexible ring 13 is preferably a unitary (or two half-ring) member having a radially extending, relatively rigid inner rim portion that is butt welded to the outer edges of the longitudinal ribs 18 (see FIG. 6 ), and a radially extending, relatively rigid outer rim portion that forms a flange for the bolted connection to a mating flange portion of the cover. A relatively thin, flexible, web portion extends axially between the inner and outer rim portions, forming the preferred “U” profile in section. As used herein, “flexible” should be understood in the context as semi-rigid with the capability to bend or flex under thermal or mechanical stresses, while retaining sufficient rigidity to transmit the rotational drive torque between one or both covers 14 , 15 and the shell body 9 . A cavity or channel is formed by the flange portions and the web, and can be considered as having a center C that lies on an imaginary circle around the drum axis. Likewise, the web can be considered as having a center that lies in radial alignment with the center of the channel, and preferably has a varying width along the direction between the flange portions, which narrows toward the center.
The external flanges of these flexible rings 13 are bolted to the drum covers 14 and 15 , which have journals to hold the two bearing assemblies 2 and 3 that are designed to take account of the changing length of the drying drum 1 in cross-machine direction, caused by the differences in temperature during heating up and cooling down. The temperature of the exhaust air is normally around 120° C., while the supply air entering the drying drum has a temperature of approximately 300° C. The two ends of the drum including flexible ring 13 are covered by an endless imperforate protective ring 16 from the outer edge of the outer flange portion inwardly beyond the inner flange portion to the edges P of the paper web. This arrangement prevents any dust or fibers from entering the cavity in the U-profile. This endless ring 16 is shrunk on in such a way that it cannot detach itself from the drum surface during the heating and cooling process, nor during drying operation.
A view of the peripheral sector of the drum 1 is illustrated in FIG. 5 . This drawing shows the covering ring 16 , which extends inwardly beyond the outer edges of the honeycombed cylinder shell 9 a distance D and marks the edges P of the paper web.
FIG. 6 shows the supporting structure of the cylinder shell 9 with longitudinal ribs 18 , with advantageous spacing α of approximately 30 to 40 mm and the connecting profiles 19 protruding beyond the longitudinal ribs in radial direction to form the honeycomb and support the paper web 7 and the conveying wire 8 . | A device for continuous drying of a pulp web, particularly a tissue web, with a drying drum ( 1 ) and an air circulating system, where the drying drum ( 1 ) has a cylindrical shell ( 9 ) designed as a honeycombed body with an annular, flexible transition profile ( 13 ) at the edges of the shell and connected to the end covers. | 3 |
RELATED APPLICATIONS
[0001] This application is the U.S. national phase entry under 35 U.S.C. §371 of International Application No. PCT/EP2014/074794, filed Nov. 17, 2014, which is related to and claims the benefit of priority of French Application No. 1302710, filed Nov. 22, 2013. The contents of International Application No. PCT/EP2014/074794 and French Application No. 1302710 are incorporated by reference herein in their entirety.
FIELD
[0002] The present invention relates to a device for ECG derivation from a catheter.
BACKGROUND
[0003] In order to control the position of a catheter during its placement precisely, especially a central venous catheter, the catheter is displaced toward the heart after having punctured the vein under permanent ECG control until the potentials of the cardiac atrium appear on the screen. It would be dangerous to push the tip of the catheter further forward since it could reach the ventricle and cause arrhythmias. The catheter is then retracted by about 2 or 3 cm. By doing so, the atrium-specific potentials disappear, and the user knows that the tip of the catheter is now in front of the atrium which corresponds to the correct position of a central venous catheter.
[0004] To realize an intracardiac ECG, an electrically conducting connection needs to be established by means of a cardiac catheter for deriving the necessary signals.
[0005] The electrically conducting connection may be established in two different ways, namely by means of an electrically conductive guide wire or else by means of an electrically conductive liquid, in particular a saline solution which is introduced into the catheter.
[0006] Both methods may be necessary one after the other at different moments of a patient's treatment. Thus, it can prove to be advantageous to establish the electrical connection during the positioning of the catheter by means of a guide wire which is systematically used during the insertion of the catheter. In contrast, the utilisation of a physiological saline solution is advantageous during the subsequent position control so that a guide wire is not required to be reinserted into the catheter.
[0007] To allow ECG signals to be derived by means of an electrically conductive liquid, a device is known for example from document EP 0 153 952 B1 which is fixed at the free end of a catheter and allows an electrically conductive liquid to be introduced into the catheter by means of a syringe. An electrical contact, from which a connection cable to the ECG device is routed, is situated at the attachment piece of the syringe.
[0008] Document DE 43 18 963 C1 discloses a similar device which also allows the contact between a contact pin in a lateral attachment piece at the device and a guide wire to be established through an electrically conductive liquid, while the guide wire passes within a channel in the device.
[0009] The known solutions presuppose in any case the use of an electrically conductive liquid supplied from outside. The equipment used must be sterile and the amount of supplied liquid must be dosed with precision so as to ensure the electrical contact.
SUMMARY
[0010] The object of the present invention is to propose a device for the ECG derivation from a catheter, which can be used with a guide wire as well as without a guide wire, and which can be manipulated in a simple and sterile manner.
[0011] The object of the invention is achieved by a device for the ECG derivation from a catheter, comprising a pipe section exhibiting a channel, which is characterized in that the channel comprises a contact pin which is connected to a terminal on the outer face of the device and is movable between a first position and a second position, the two positions representing different positions with respect to the channel axis.
[0012] The pipe section of such a device can be slipped onto a guide wire situated in a catheter for deriving a signal. The contact pin which is disposed within the channel of the pipe section is then in a first position, in which the passage of the guide wire through the pipe section is perfectly possible.
[0013] The contact pin can then be displaced to a second, different position with respect to the axis of the channel. In this position, the guide pin establishes an electrical connection with the guide wire. In this position of the guide pin, the guide wire can then be slightly trapped so that the device can no longer be freely displaced along the guide wire. An ECG device can be connected at the terminal on the outer side of the device which is connected to the contact pin. The signals from the tip of the guide wire are then transmitted to the ECG device without any loss.
[0014] The introduction of a conductive liquid into the catheter, which must be performed in a sterile manner, is not necessary in this case of application. The device may be located apart from the free end of the catheter on the guide wire and thus does not pose any sterility problem of the catheter.
[0015] The displacement of the contact pin may be linear or follow a circular trajectory. The device may be provided with a drum for instance, which is mounted to be rotatable about an axis perpendicular to the axis of the pipe section. The contact pin is disposed on the drum in an eccentric manner. The pin can move along a circular trajectory due to the rotation of the drum. The guide wire can introduce itself easily into the pipe section, provided the contact pin remains outside the axis of the pipe section. The rotation of the drum allows the contact pin to be set into a different position with respect to the axis of the tube section. Preferably, the trajectory of the pin crosses the axis of the pipe piece so that the guide wire is slightly under constraint to slightly leave the axis, and can thus be locked.
[0016] For example, the first and the second positions of the contact pin can be homothetic with respect to the axis of the pipe section. The contact can be established by rotating the drum by 180°.
[0017] In a preferred embodiment, the ECG derivation device exhibits at an end of the pipe section a terminal for a catheter. The device can also be used without a guide wire when an electrically conductive liquid, such as a physiological saline solution for example, is poured into the pipe section. The liquid then establishes the contact between the catheter and the contact pin, and the signal can be derived. A terminal for a syringe, in particular a female Luer lock, can be provided for introducing the liquid.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0018] Hereinafter, different embodiments of the invention are described in more detail by means of the annexed Figures, in which:
[0019] FIG. 1 is a schematic representation of the principle of the present invention;
[0020] FIG. 2 a shows the schematic representation of a preferred embodiment of the present invention with the contact pin in the first position;
[0021] FIG. 2 b shows the schematic representation of the embodiment of FIG. 2 a with the contact pin in the second position;
[0022] FIG. 3 a shows another preferred embodiment of the present invention in a sectional view;
[0023] FIG. 3 b shows the use of the embodiment of FIG. 3 a with the use of a guide wire; and
[0024] FIG. 3 c shows the use of the embodiment of FIG. 3 a without a guide wire.
DETAILED DESCRIPTION
[0025] FIG. 1 is a schematic representation of the principle of the present invention. The Figure represents the ECG derivation device according to the invention with a pipe section 2 as a main part. The pipe section comprises a channel 3 inside thereof and is dimensioned to receive a guide wire 4 . The inside of the channel 3 comprises a contact pin 5 which can move between a first position P 1 and a second position P 2 along the trajectory T L , which is represented as a dotted line in the Figure.
[0026] The contact pin 5 is connected to a terminal/connection/access 6 disposed on the outer face of the device 1 by which a connection cable 7 can be branched off for connecting to an ECG device.
[0027] In the first position P 1 , the contact pin is outside the axis A of the pipe section 2 , so that the guide wire 4 can be easily introduced. The device can thus be easily displaced at the end of the guide wire 4 mounted in a catheter.
[0028] If the guide wire 4 is introduced into the channel 3 of the pipe section 2 , the contact pin 5 can be displaced along its trajectory T L . At this time, the pin enters the axis of the channel and forces the guide wire 4 slightly against the opposite wall of the channel 3 to establish a secure electrical contact between the contact pin 5 and the guide wire 4 . Thus, an electrical connection between the end of the guide wire 4 situated within the patient, by means of the contact pin 5 , the terminal 6 and the connection cable 7 is achieved with the ECG device not shown in this Figure.
[0029] FIG. 2 a shows the schematic representation of a preferred embodiment of the present invention with the contact pin 5 in the first position. The guide wire 4 is introduced into the channel 3 of the device 1 along the axis A.
[0030] The contact pin 5 is situated on a drum 9 rotatably mounted in a cylindrical extension 8 of the pipe section and is connected in an electrically conductive manner with the terminal 6 in the rotation axis of the drum. In the first position, the contact pin is situated outside the axis A of the pipe section without any contact with the guide wire 4 .
[0031] FIG. 2 b shows the schematic representation of the embodiment of FIG. 2 a with the contact pin 5 in the second position. To this end, the drum 9 is rotated by about 90° using the handle 10 situated outside the device 1 . The contact pin 5 moves along the circular trajectory T C in the axis A of the channel 3 of the pipe section 2 , and there abuts against the guide wire 4 . The electrical contact is established. The position of the handle 10 permits to determine immediately whether the contact is established or not.
[0032] The device 1 can also be dimensioned such that the drum can be rotated by 180°, while the contact pin is arranged in the second position with respect to the channel axis in a homothetic manner relative the first position. In the second position, the contact pin 5 compresses the guide wire 5 again to withdraw it from its position along the axis A of the channel 3 , and establishes an electrical contact. The advantage of this position is that the drum is rotatable by 360°, and even when it is forced, there is no risk of damaging pieces such as the contact pin inside the device.
[0033] FIG. 3 a shows another preferred embodiment of the present invention. Here, a terminal/connection/access 11 for a catheter is provided at an end of the pipe section 2 , while a female Luer lock 12 is provided to connect to a syringe.
[0034] This embodiment of the invention is particularly advantageous in that it can be used both with a guide wire and an electrically conductive liquid. A catheter can be positioned first with the device, for instance, by means of a guide wire. For doing this, a contact can be established with a guide wired used during the positioning of the catheter. The introduction of a liquid, which is subjected to high requirements regarding sterility, is not necessary. The guide wire can be withdrawn once the catheter is positioned. The regular control of the catheter's position can be performed on the basis of the conventional liquid process without any need to use a separate device. On the one hand, there is no sterility problem as could have been the case when another device after the implantation of the catheter would have been added to its free end, on the other, savings can be realized in that the same single device is used both for the positioning of the catheter by means of a guide wire and subsequently without a guide wire.
[0035] FIG. 3 b shows the device according to FIG. 3 a in the case of usage with a guide wire 4 . The terminal 11 is associated with a catheter 13 in which the guide wire 4 is situated. The guide wire 4 passes through the channel 3 of the device 1 and exits the channel 3 at the opposite end. The contact pin 5 is in the second position where it establishes an electrical contact with the guide wire 4 .
[0036] FIG. 3 c shows the device of FIG. 3 b after the guide wire has been withdrawn. For doing this, the contact pin 5 is set in the first position which allows the guide wire to be withdrawn without any resistance. To ensure ECG signals to be derived, a commercially available syringe 14 including a sterile physiological saline solution is placed at the Luer lock 12 at the opposite end of the device 1 , and the saline solution is introduced into the channel 3 of the device and thus into the catheter 13 . The saline solution establishes an electrical contact with the contact pin 5 in the channel 3 of the device. The saline solution in the catheter 13 finally serves the purpose of establishing an electrical contact between the distal end of the catheter and the contact pin 5 and then by means of the terminal 6 and a suitable cable to the ECG device. | A device for the ECG derivation from a catheter can be used with a guide wire as well as without a guide wire, and can be manipulated in a simple and sterile manner. The device includes a pipe section exhibiting a channel that includes a contact pin which is connected to a terminal at the outer face of the device and is movable between a first position and a second position, the two positions representing different positions with respect to the channel axis. | 0 |
BACKGROUND OF THE INVENTION
[0001] In the manufacture of paper products from cellulose fibers, such as facial tissue, bath tissue, paper towels, dinner napkins and the like, it is often desirable to enhance product properties by the addition of chemical additives. Properties that may be enhanced using additives include: dry strength, wet strength, softness, absorbency, opacity, brightness and color.
[0002] Softness is a key attribute in tissue products. A feeling of softness imparts to human skin a clean and soothing effect. Improving the balance of tissue softness and strength is a continuous effort in tissue making. Tissue product designers attempt to maximize the strength and softness of tissues. It has been recognized as a general rule of tissue manufacture that the greater the strength of a given tissue, the lower the softness of that tissue. There is usually an inverse relationship between strength and softness.
[0003] In general, prior efforts have been directed at achieving softness using debonders directed at reducing the inter-fiber bonding within the tissue structure or coating the tissue surface with such chemicals. Additionally and/or alternatively, mechanical means have been used in the art of tissue making to increase the softness of tissue paper. For example, many tissues are creped with a doctor blade to increase softness. Through-air drying processes, however, are not as amenable to creping as Yankee dryer processes. Uncreped tissues sometimes are subjected to a rush transfer step to increase softness.
[0004] During the papermaking process, additives are commonly added to fiber slurries in the wet end of a papermaking machine. Wet end chemical addition may provide a relatively uniform distribution of chemical additives on the fiber surfaces of a tissue product. Additionally, wet end chemical addition sometimes facilitates the selection of a particular fraction to be treated with a specific chemical additive in order to enhance the performance of the paper, or to enhance the performance of a chemical additive. Wet end chemical addition enables multiple additives of various types to be added to a fiber slurry, either simultaneously or sequentially, prior to formation of the paper web. However, adding debonder to the fiber furnish results in debonder being present in the whitewater that is recirculated after formation of the paper web. As there is often a large quantity of white water, the presence of additives in the whitewater can result in significant down time for grade changes, or large amounts of waste material produced when changing chemical compositions. Topical spraying, printing and size press are other methods for chemical addition. However, such chemical addition methods result in higher concentrations of chemical at the surface of the paper sheet, with lower concentrations in the middle of the sheet.
[0005] What is needed in the industry is a technique of manufacture that will result in a softer, stronger tissue. A system that will provide a final tissue product having a desirable strength, with good tactile sensory softness characteristics in a process of manufacture that is relatively simple to apply at a reasonable cost would be highly desirable.
SUMMARY OF THE INVENTION
[0006] In one aspect of the invention, a method of making a tissue product includes the steps of: forming a web of cellulosic fibers on a forming wire; thereafter, treating the exposed surface of the web with a treatment composition that includes a chemical debonding agent; subjecting the opposing surface of the web to vacuum suction whereby the chemical debonding agent is distributed substantially through the entire thickness of the web; and through-air drying the web. In another embodiment, the chemical debonding agent is distributed at a substantially uniform concentration through substantially the entire thickness of the sheet. Desirably, the vacuum suction is applied without removing a substantial quantity of the chemical debonding agent from the web. The method may optionally include a rush transfer operation. In one embodiment the treatment composition is applied to the web in between a first through-air drying operation and a second through-air drying operation.
[0007] Desirably, the treatment composition may be applied to the web when the web has a consistency of greater than about 10%. More desirably, the treatment composition may be applied to the web when the web has a consistency of greater than about 15% and less than about 80%. Even more desirably, the treatment composition may be applied to the web when the web has a consistency of greater than about 15% and less than about 30%.
[0008] The treatment composition may include any of those chemical debonding agents known to one skilled in the art. In one embodiment, the chemical debonding agent comprises a quaternary amine compound, for example, an oleyl imidazolinium compound. In the dried product, the chemical debonding agent may be present in the product in an amount of from about 0.01% to about 10% by weight. In another embodiment, the chemical debonding agent may be present in an amount effective to soften substantially the entire thickness of the sheet.
[0009] In another embodiment, the treatment composition further comprises a lubricant and a surfactant. The lubricant may be, for example, a lanolin derivative. The surfactant may include a polyethylene glycol ester, a polypropylene glycol ester, mixtures thereof, and so forth.
[0010] The tissue product may include layers of different types of cellulosic fibers. For example, the tissue product may include a middle layer positioned in between a first outer layer and a second outer layer of fibers, the first and second outer layers comprising hardwood fibers and the middle layer comprising softwood fibers. In another embodiment, the method may further include the step of combining the tissue treated sheet with additional tissue layers to form a layered tissue product.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] A full and enabling disclosure of this invention, including the best mode shown to one of ordinary skill in the art, is set forth in this specification.
[0012] FIG. 1 shows a plan view of one embodiment of a system and process for producing uncreped through-air dried paper webs.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Reference now will be made to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not as a limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in this invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present invention are disclosed in or are obvious from the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions.
[0014] A “debonding agent” or “debonder” refers to any chemical that can be incorporated into paper products, such as tissue, to prevent or disrupt interfiber or intrafiber hydrogen bonding. In general, a debonder stops the hydrogen bonding and reduces the strength of the tissue by preventing the formation of bonds. As a general rule, use of a debonder softens the tissue. However, a debonding agent also can cause the tissue to lint or slough, which is undesirable. Therefore, softness is normally inversely proportional to strength when it comes to tissue.
[0015] Depending upon the nature of the chemical, debonding agents may also act as softening agents. A softening agent is generally any chemical additive that can be incorporated into paper products, such as tissue, to provide improved tactile feel.
[0016] These chemicals can also act as debonding agents or can act solely to improve the surface characteristics of tissue, such as by reducing the coefficient of friction between the tissue surface and the skin on the hand.
[0017] In contrast, the term “bonding agent” refers to any chemical that can be incorporated into tissue to increase or enhance the level of interfiber or intrafiber bonding in the sheet. The increased bonding can be either ionic, hydrogen or covalent in nature.
[0018] The current invention is geared towards the addition of a debonder or softening agent during the manufacture of a paper product, such as a tissue. Typically, the debonder is added to the tissue at an add-on rate of from about 0.01 to about 10 weight percent of the fiber. For example, the add-on rate may be from about 0.1 to about 5 weight percent of the fiber. Desirably, the add-on rate may be from about 0.1 to about 0.5 weight percent of the fiber.
[0019] According to the present invention, various debonders can be used. Exemplary debonders include silicone compounds, mineral oil and other oils or lubricants, quaternary ammonium compounds with alkyl side chains, imidazolinium compounds, and so forth. Examples of quaternary ammonium compounds include hexamethonium bromide, tetraethylammonium bromide, lauryl trimethylammonium chloride, dihydrogenated tallow dimethylammonium methyl sulfate, oleyl imidazolinium, and so forth. Other debonders can be tertiary amines and derivatives thereof; amine oxides, saturated and unsaturated fatty acids and fatty acid salts; alkenyl succinic anhydrides; alkenyl succinic acids and corresponding alkenyl succinate salts; sorbitan mono-, di- and tri-esters, including but not limited to stearate, palmitate, oleate, myristate, behenate sorbitan esters, and so forth. The above debonders can be used alone or in combination.
[0020] In one embodiment of the current invention, quaternary amine debonders such as, for example, Hercules® PPD D-1203 debonder may be used. Hercules® PPD D-1203 debonder is manufactured and distributed by Hercules Incorporated of Wilmington, Del. Hercules® PPD D-1203 debonder is a proprietary mixture that is believed to include approximately 63% quaternary amine salt mixture. Hercules® PPD D-1203 debonder is available as an amber liquid having a viscosity of 200 centipoise at 25° C. that is dispersible in water.
[0021] In another embodiment of the current invention, a blend of nonionic and cationic surfactants such as, for example, Arosurf PA777 debonder may be used. Arosurf PA777 debonder is manufactured and distributed by the Goldschmidt AG of Essen, Germany (“Arosurf” is believed to be a trademark of Goldschmidt). Arosurf PA777 debonder is a nonvolatile specialty formulation which imparts fiber debonding and softening, conforms to FDA regulations for food contact, and is believed to be based on an imidazolinium methosulphate. Arosurf PA777 debonder is available as a yellow-brown liquid having a viscosity of 180 centipoise at 25° C. that is dispersible in water.
[0022] Debonders applied at the wet end of the papermaking process may increase surface softness by reducing base sheet strength. It has been discovered by the present invention, however, that topically applying the debonder directly on the sheet followed by drawing the debonder through the thickness of the sheet will provide increased surface softness at similar strength levels. Put another way applying the debonder directly on the sheet followed by drawing the composition through the thickness of the sheet will provide similar strength and softness at reduced chemical add-on levels.
[0023] Any of the debonders mentioned above may be added during the manufacture of the tissue. The debonder composition can be applied to the surface of the paper product by spraying, rotogravure printing, trailing blade coating, flexographic printing, and the like. Desirably, the debonder composition is sprayed on the surface of the formed sheet. Spraying is performed using a spray nozzle that adds the debonder to the tissue. In one embodiment, the debonder may be applied to the exposed surface of the tissue while the tissue is on a forming wire or fabric, or while the tissue is on a transfer fabric. The debonder may also be applied to the outer layer of a multi-layer tissue.
[0024] The debonder may require dilution with water when applying using a spraying method. For example, the debonder may be present in an aqueous composition in an amount less than about 30% by weight, such as in an amount less than about 20% by weight. For example, in one embodiment, the debonder can be present in an aqueous composition in an amount less than about 10% by weight, such as less than 5% by weight. In one particular embodiment, the debonder can be present in an aqueous composition in an amount less than about 3% by weight.
[0025] The amount of moisture contained within the web when the debonder composition is applied to the web can vary depending on the particular application and process conditions. In general, the consistency of the web can be from about 10% to about 80%. More particularly, the consistency of the web can be from about 15% to about 30%.
[0026] After application of the composition to the surface of the paper, vacuum is applied to the opposite surface of the paper to draw the composition through the thickness of the paper web. The vacuum may be applied by conventional vacuum sources including uhle boxes, vacuum boxes, suction boxes, and so forth. The level of vacuum applied may be controlled to draw the debonder through the thickness of the web. Desirably, the level of vacuum is applied without removing substantial quantities of the debonder from the web, and more desirably the level of vacuum is applied without removing the debonder from the web. For example, the level of vacuum used for drawing the debonder through the web can be from about 3 to about 15 inches (about 75 to about 380 millimeters) of mercury. Water containing debonder that is vacuumed from the web can be recycled or sewered. Because the quantity of water in the spray system is small compared to the sheet forming process, grade changes can be made much more rapidly and with less waste than when adding debonder at the wet end of the paper making process.
[0027] In general, the debonder composition of the present invention can be applied to any suitable paper product, such as bath tissue, facial tissue, paper towels, industrial wipers, and the like. The paper product can be made in any suitable manner. For example, paper products utilized in the present invention can be made utilizing adhesive creping, wet creping, double creping, embossing, wet-pressing, air-pressing, through-air drying, creped through-air drying, uncreped through-air drying, as well as other steps known in the paper art. By way of illustration, various tissue making processes are disclosed in U.S. Pat. No. 5,607,551 issued Mar. 4, 1997 to Farrington and U.S. Pat. No. 5,667,636 issued Sep. 16, 1997 to Engel et al., which are incorporated herein by reference.
[0028] A variety of conventional papermaking apparatus may be used in the application of this invention, as they are known by persons of skill in the art. Conventional operations may be used with respect to the stock preparation, headbox, forming fabrics, web transfers, and through-air drying.
[0029] Conventional stock preparation equipment may be used to prepare papermaking fibers according to one embodiment of the present invention. The stock preparation equipment may include one or more stock chests. When more than one stock chest is used, there may be a dewatering device between the stock chests. Papermaking fibers and water are added to the first stock chest to form a fiber slurry. The fiber slurry in the first stock chest typically has a consistency of about 20% or lower, and particularly about 5% or lower, such as about 3 to about 5%. The fiber slurry in the first stock chest is desirably under agitation using a mixing blade, rotor, recirculation pump, or other suitable device for mixing the fiber slurry.
[0030] One or more chemical additives may be supplied from a reservoir and added to the fiber slurry in the first stock chest. The amount of chemical additive may range from about 0 to about 20 kg/metric ton. The fiber slurry and chemical additive are desirably allowed to remain together in the first stock chest under agitation for a residence time sufficient to allow the papermaking fiber to absorb a substantial portion of the chemical additive. A residence time of about 15 to about 30 minutes, for example, may be sufficient.
[0031] When more than one stock chest is used, the fiber slurry is thereafter transferred through suitable conduits and a pump to the dewatering device. In this illustrated embodiment, the dewatering device can comprise a belt press, although alternative dewatering devices such as a centrifuge, a nip thickening device or the like may be used. The fiber slurry is injected between a pair of foraminous fabrics such that press filtration removes water from the slurry. The press filtrate comprises a portion of the process water along with unabsorbed chemical additives in the water. The belt press or other dewatering device suitably increases the fiber consistency of the slurry to about 20% or greater, and particularly about 30% or greater. Desirably, at least a portion of the unabsorbed chemical additive can be removed from the process to minimize the amount sent forward with the chemically treated finish.
[0032] When more than one stock chest is used, the thickened fiber slurry is then transported through conduits to a subsequent stock chest. The fiber slurry is then re-diluted with fresh water from a suitable reservoir and optionally agitated using a mixing device. The fiber consistency of the slurry is suitably decreased to about 20% or less, and particularly about 5% or less, such as about 3 to about 5%. The fiber slurry may then be removed from the subsequent stock chest through suitable conduits and a pump for subsequent processing. Alternatively, the fiber slurry may be processed through the foregoing procedure again in an effort to further increase the chemical additive retention level.
[0033] In an alternative embodiment of the present invention, the stock preparation equipment may be used to additionally mechanically treat the fibers. Dispersers suitable for use in the present method are disclosed in U.S. Pat. Nos. 5,348,620 and 5,501,768 which are incorporated herein by reference.
[0034] One suitable process for making paper products from the fiber slurries is the uncreped through-air drying method (UCTAD). One or more embodiments of the uncreped through-air drying method is disclosed in U.S. Pat. No. 5,656,132 to Farrington, Jr. et al., which is incorporated herein by reference.
[0035] As shown in FIG. 1 , one embodiment of the present invention includes a twin wire former having a papermaking headbox 10 that injects or deposits a stream 11 from the fiber slurry onto a forming fabric 13 to form a cellulosic web. The web is then transferred to a fabric 15 which serves to support and carry the newly-formed wet web downstream in the process as the web is partially dewatered to a consistency of about 10 dry weight percent. Additional dewatering of the wet web can be carried out, such as by vacuum suction, while the wet web is supported by the fabrics.
[0036] The transfer fabric 15 travels at a slower speed than the forming fabric in order to impart increased MD (machine direction) stretch into the web. A so-called “kiss” transfer is completed in many embodiments to avoid compression of the wet web, preferably with the assistance of a vacuum shoe. The transfer fabric may be a fabric having impression knuckles or it may be a smoother fabric such as Asten 934, 937, 939, 959 or Albany 94M, which are fabrics known to persons of skill in the art.
[0037] If the transfer fabric is of the impression knuckle type described herein, it can be utilized to impart some of the same properties as the through-air drying fabric and can enhance the effect when coupled with a through-air drying fabric also having the impression knuckles. When a transfer fabric having impression knuckles is used to achieve the desired CD (cross direction) stretch properties, it provides the flexibility to optionally use a different through-air drying fabric, such as one that has a decorative weave pattern, to provide additional desirable properties not otherwise attainable.
[0038] One or more spray nozzles 17 apply a debonder to a surface of the web. A vacuum source 18 draws the debonder through the thickness of the web.
[0039] The web then may be transferred from the transfer fabric to a through-air drying fabric 19 with the aid of a vacuum transfer roll 20 or a vacuum transfer shoe. The through-air drying fabric typically travels at about the same speed or a different speed relative to the transfer fabric. If desired, the through-air drying fabric may be run at a slower speed to further enhance MD (machine direction) stretch. Transfer is preferably carried out with vacuum assistance to ensure deformation of the sheet to conform to the through-air drying fabric, thus yielding desired bulk, flexibility, CD stretch and appearance. The through-air drying fabric is preferably of the impression knuckle type, but it is not necessary that it be of that type.
[0040] The level of vacuum used for the web transfers can be from about 3 to about 15 inches (about 75 to about 380 millimeters) of mercury, such as from about 10 to about 15 inches (about 254 to about 380 millimeters) of mercury. The vacuum shoe (negative pressure) used in the rush transfer step can be supplemented or replaced by the use of positive pressure from the opposite side of the web to blow the web onto the next fabric in addition to or as a replacement for sucking it onto the next fabric with vacuum. Also, a vacuum roll or rolls can be used to replace the vacuum shoes.
[0041] While supported by the through-air drying fabric, the web is dried to a consistency of about 94% or greater by a through-air dryer 21 and thereafter transferred to a carrier fabric 22 as a dried base sheet 23 . The dried base sheet 23 is transported to a reel 24 using the carrier fabric 22 and an optional carrier fabric 25 . An optional pressurized turning roll 26 can be used to facilitate transfer of the web from the carrier fabric 22 to the optional carrier fabric 25 .
[0042] Many fiber types may be used in the practice of the present invention including hardwood or softwoods, straw, flax, milkweed seed floss fibers, abaca, hemp, kenaf, bagasse, cotton, reed, and the like. Numerous different types of papermaking fibers may be employed, including bleached and unbleached fibers, fibers of natural origin (including wood fiber and other cellulosic fibers, cellulose derivatives, and chemically stiffened or crosslinked fibers), some component portion of synthetic fibers (synthetic papermaking fibers include certain forms of fibers made from polypropylene, acrylic, aramids, acetates, and the like), virgin and recovered or recycled fibers, hardwood and softwood, and fibers that have been mechanically pulped (e.g., groundwood), chemically pulped (including but not limited to the kraft and sulfite pulping processes), thermomechanically pulped, chemithermomechanically pulped, and the like.
[0043] Mixtures of any subset of the above mentioned or related fiber classes may be used. The fibers can be prepared in a multiplicity of ways known to be advantageous in the art. Useful methods of preparing fibers include dispersion to impart curl and improved drying properties.
[0044] Further, a single headbox or a plurality of headboxes may be used in the practice of the invention. The headbox or headboxes may be stratified to permit production of a multilayered structure from a single headbox jet in the formation of a web. In particular embodiments, the web may be produced with a stratified or layered headbox to preferentially deposit shorter fibers on one side of the web for improved softness, with relatively longer fibers on the other side of the web or in an interior layer of a web having three or more layers. The web is desirably formed on an endless loop of foraminous forming fabric which permits drainage of the liquid and partial dewatering of the web. Multiple embryonic webs from multiple headboxes may be couched or mechanically or chemically joined.
[0045] In one embodiment, the formed paper web contains three layers of fibers. In particular, the web may contain a middle layer of softwood fibers surrounded by two outer layers of hardwood fibers. Paper broke can also be added to the outer layers in an amount less than about 25% by weight of the layer, for example, in an amount of less than about 10% by weight of the layer. In this embodiment, each of the outer layers can comprise from about 20% to about 40% of the total weight of the web.
[0046] In one embodiment, application of the debonder is performed between a rush transfer step and a through-air drying step. Prior to the through air drying step, the consistency of the web in one embodiment is less than about 40% such as from about 10% to about 30%. For example, in one embodiment, the consistency is from about 26% to about 29% after rush transfer and prior to drying.
[0047] In an alternative embodiment, the papermaking process can include a first through-air dryer and a second consecutive through-air dryer. Application of the debonder can be performed in between the through-air dryers. In this embodiment, the consistency of the web can be from about 40% to about 80%.
[0048] Other chemical additives may be used in conjunction with the present invention. These additives include: dry strength aids, wet strength aids, softening agents, debonding agents, absorbency aids, sizing agents, dyes, optical brighteners, chemical tracers, opacifiers, dryer adhesive chemicals, and the like. Additional forms of chemical additives may include: pigments, emollients, humectants, virucides, bactericides, buffers, waxes, fluoropolymers, odor control materials and deodorants, zeolites, perfumes, debonders vegetable and mineral oils, humectants, sizing agents, superabsorbants, surfactants, moisturizers, UV blockers, antibiotic agents, lotions, fungicides, preservatives, aloe-vera extract, vitamin E, or the like. Suitable chemical additives are adsorbable by the cellulosic papermaking fiber and are usually water soluble or water dispersible.
[0049] The following Examples serve to illustrate possible approaches pertaining to the present invention. The particular amounts, proportions, compositions, and parameters are meant to be exemplary, and are not intended to specifically limit the scope of the invention.
EXAMPLES
[0050] Uncreped through-air dried tissue products were produced as described below. The chemicals screened included the following examples:
[0051] 1) Hercules® PPD D-1203 debonder
[0052] 2) Arosurf PA 777 debonder
[0053] The speed of the continuous sheet former machine used in the testing was about 50 ft./minute. The headbox used was a Voith three-layer headbox. The fiber furnish used for each layer was 53% recycled fiber, 31% northern softwood kraft fiber, and 16% southern softwood kraft fiber. The forming wire was a Voith 2164B. After formation, the wet sheet is transferred to a transfer wire, Voith 2164. The chemical composition sprayed on the sheet was according to Table 1.
[0054] The spraying equipment used comprised Spraying Systems Company spray nozzles 1/4 JCO-SS+SUE15B-SS with SUE 15B spray set-up. The spray boom was located just prior to the vacuum slot on the fabric. The spray fans were aimed directly at the sheet. Given the configuration of the machine, this resulted in the debonder formulation being sprayed at the exposed surface of the tissue. Two nozzles were placed to improve uniformity. The concentration of the chemical solutions was adjusted accordingly to obtain the desired target add-on. The geometry and pressure were maintained constant for all samples. All samples had a dry basis weight of 41 gsm.
TABLE 1 Tensile Tensile Rush Add-On (MD) % Stretch (CD) % Stretch Geometric Mean Tensile Caliper Sample % Debonder % grams (MD) grams (CD) grams (mils) 1 22 none 0 5316 18.2 2773 5.9 3840 24.5 2 22 PPD D1203 1 1689 14.8 542 6.3 957 25.2 3 22 none 0 5761 18.2 2778 6.1 4000 24.9 4 22 PA777 .5 2809 16.3 952 7.7 1635 25.8 5 22 PA777 .25 2915 16.6 1189 7.4 1861 — 6 10 water 0 4333 17.0 2038 9.0 2972 29.6 7 10 water 0 6895 6.3 2134 7.1 3836 24.7 8 10 water 0 6681 6.8 2786 6.6 4314 25.6 9 10 PA777 .25 4600 6.2 1641 5.9 2748 26.1 12 10 PA777 .125 4589 6.1 1379 7.1 2515 26.8 13 10 none 0 7868 7.4 3325 5.5 5114 21.6 14 10 PA777 .125 5358 6.0 1463 7.0 2800 — 15 10 PPD D1203 .25 4653 6.4 1190 7.1 2353 28.1
[0055] It is understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions. The invention is shown by example in the appended claims. | Disclosed is a method of making a soft, strong cellulosic tissue sheet comprising the steps of forming a web of cellulosic fibers on a forming wire, thereafter treating the exposed surface of the web with a treatment composition comprising a chemical debonding agent, subjecting the opposing surface of the web to vacuum suction whereby the chemical debonding agent is distributed substantially through the entire thickness of the web, and through-air drying the web. The method allows grade changes to be made much more rapidly and with less waste than when adding debonder at the wet end of the paper making process. | 3 |
BACKGROUND OF THE INVENTION
One of the primary safety problems facing persons operating electric pressing irons involves the fact that the iron, if left unattended can constitute a fire or safety hazard to children. In the past a number of schemes have been developed to interrupt power to an electric heating element of a pressing iron in the event that the iron is not being used.
Recently an electronic pressing iron was developed which has a motion and attitude sensing circuit which terminates a flow of electric power to the heating element when the pressing iron is positioned with its soleplate horizontal and not moving for a period of thirty seconds. That electronic pressing iron is disclosed in a U.S. patent application, Ser. No. 605,442, filed Apr. 27, 1984, entitled ELECTRONIC PRESSING IRON and assigned to the same assignee as this application.
That electronic pressing iron also has the ability to interrupt electric power to the electric heating element when the pressing iron is positioned with its soleplate in a substantially vertical plane or is resting on its heel rest for a period of ten minutes.
Thus, it may be appreciated that when the pressing iron has its soleplate in the lowered or horizontal position electric power is quickly interrupted if the pressing iron is not being moved in order to prevent damage to fabrics upon which the iron may be resting and to avoid the likelihood of fire.
Similarly, when the pressing iron was positioned in the soleplate raised position, electric power was interrupted to the heating element after a ten minute period in that position to allow the soleplate to cool down.
One of the drawbacks of that electronic pressing iron lies in the fact that the circuit required to perform the motion and attitude sensing functions is relatively bulky, portions of it being located in the handle of the pressing iron, ard other portions being located in a heel rest cavity within the pressing iron. That construction requires numerous electrical leads which connect the circuits in the handle to the circuits in the heel rest to be threaded through the back of the pressing iron, leading to significantly increased production costs over those found in a conventional pressing iron. In addition, the switching device which controls the electric power flowing to the heating element comprises a direct current relay which is relatively expensive and bulky. Additional power handling circuits are required to convert the alternating line current which the pressing iron receives to direct current so that the direct current relay may be employed in the circuit.
Thus there is a need for a low cost compact circuit which may be substantially enclosed within the handle portion of the pressing iron away from the heel rest portion where the circuit may be exposed to moisture. What is also needed is an electronic pressing iron which can interrupt power to its heating element after a relatively brief period in which the soleplate is stationary and horizontal and which can interrupt power to its electric heating element after a longer period when the soleplate is in a substantially vertical plane.
SUMMARY OF THE INVENTION
An electric pressing iron is disclosed herein which includes a soleplate having an electric resistance heating element mounted in good heat conducting relationship therewith. The electric heating element is adapted to receive alternating current from a suitable external source. A plastic shell housing is connected to the soleplate and includes a motion and attitude sensing circuit having a mercury switch operatively associated therewith. The motion and attitude sensing circuit also includes a programmable timer driven from a constant period clock circuit. The programmable timer provides a first relatively short period timing function which is reset from time to time as the pressing iron is moved with the soleplate in the horizontal or down position. The pressing iron also includes a long period timing function which is periodically reset except when the iron is stationary with the soleplate in the raised or vertical position.
In the instant invention when the electronic pressing iron is resting on its soleplate and not moving for thirty seconds, the programmable timer generates an output signal which is fed to a silicon controlled rectifier which controls a thermal relay. The thermal relay in a preferred form of the invention comprises a ceramic positive temperature coefficient (PTC) heater connected in good electrical and heat conducting relationship with a snap action thermostat. The snap action thermostat is connected in series with the source of alternating line current and the electric resistance heating element in the soleplate. When the PTC heater is energized by the programmable timer at the end of the thirty second interval, the snap action thermostat opens, interrupting the flow of electric power to the electric heating element. Likewise, when the electronic pressing iron is in the heel rest position, after a period of sixteen minutes, the programmable timer produces an output signal which energizes the PTC heater causing the thermostat of the thermal relay to open and to interrupt electric power to the electric heating element.
A neon indicating lamp is connected in series with the PTC heater of the thermal relay. The neon indicating lamp remains off when the electronic pressing iron is switched off. The lamp is on and illuminated steadily when the electronic pressing iron is on and flashes when the programmable timer has timed out either in the soleplate down position or in the heel rest position to provide an output indication to the user that the motion and attitude sensing circuit has disabled the electric heating element.
An object of the present invention is to provide an electronic pressing iron having a compact and reliable motion and attitude sensing circuit for automatically interrupting power to an electric heating element in a soleplate when the electronic pressing iron is not being used.
Another object of the instant invention is to provide an electronic pressing iron having a compact thermal relay control which occupies very little space but is able to switch relatively large currents flowing through the electric heating element in the soleplate.
A still further object of the present invention is to provide an electronic pressing iron having a highly accurate, programmable timer which is unaffected by manufacturing variations.
A still further object of the instant invention is to provide an electronic pressing iron having a digital timer which is unaffected by the presence of moisture in the vicinity of the motion and attitude sensing circuit in order to provide a highly accurate timing function.
Another object of the present invention is to provide an electronic pressing iron wherein the user is provided an output indication as to whether the iron is off, on, or the heating element is disabled.
Further objects and advantages of the instant invention will become apparent to one skilled in the art upon perusal of the following specification and claims in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an electronic pressing iron comprising our invention;
FIG. 2 is a side elevational view of a thermal relay contained within the electronic pressing iron of FIG. 1 for controlling a flow of electric current through an electric heating element in a soleplate of the electronic pressing iron;
FIG. 2A is a sectional view taken on line A--A of FIG. 2;
FIG. 3 is a side elevational view having portions broken away to show sectional details of the electronic pressing iron of FIG. 1; and
FIG. 4 is a schematic diagram of the electrical circuit of the electronic pressing iron of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 of the drawings, there is shown an electronic pressing iron 10 embodying the instant invention and having a soleplate 12 and a plastic housing 14 connected thereto. The soleplate 12 has an electric resistance heating element 16 (shown only schematically in FIG. 4) mounted in good heat conducting relationship therewith. A conventional soleplate temperature control thermostat 18 of a type well known to those skilled in the art and employed in electric pressing irons is connected to the soleplate 12 by a threaded fastener 20 which engages a thermally conducting mounting block 22.
The plastic housing 14 includes a phenolic lower housing 24 and a thermoplastic polyester upper housing 26. The phenolic lower housing 24 and the thermoplastic polyester upper housing 26 are sealed together with a room temperature vulcanizing compound at a joint 28. The plastic housing 14 also has a heel rest portion 29 located at the rear thereof.
The soleplate 12 has a bottom face or pressing surface 30 adapted to be placed in contact with a suitable fabric to be ironed.
The lower phenolic housing 24 and the upper thermoplastic polyester housing 26 together define a water tank 32 which may be filled with water through a funnel-like structure 34 at the front of the electronic pressing iron 10 as is conventional. Water contained in the tank 32 may be delivered to the soleplate 12 where it is converted to steam in a well known manner. The water delivery is controlled by a steam setting control 36 which is mechanically connected to a steam valve structure 38 in a well known fashion.
The lower phenolic housing 24 is secured to the soleplate 12 by a plurality of threaded fasteners including a threaded fastener 40 connected to a rear clip 42 which is connected by a threaded fastener 44 to the soleplate 12. The upper thermoplastic polyester housing 26 is secured to the lower phenolic housing 24 by a plurality of threaded fasteners, one of which is shown in FIG. 3 and indicated as fastener 46. The upper thermoplastic housing 26 includes a handle section 50 having a grip portion 52. The handle section 50 and the grip portion 52 define a hollow interior portion 54.
A temperature selector 56 is mounted on an upper part of the upper thermoplastic housing 26 and is connected by a control rod 58 to the thermostat 18 in order to select a temperature setpoint to which the thermostat 18 may control the soleplate in a manner well known to those skilled in the art.
A pair of reciprocating pumps 59, one of which is shown in FIG. 3, is contained in the upper portion of the upper thermoplastic housing 26. The reciprocating pumps 59 are adapted, respectively, to draw water from the water tank 32 and deliver it to a spray head 60 or to the soleplate 12 in order, respectively, to produce a spray of water from the front of the electronic pressing iron 10 for dampening fabrics to be ironed and to produce an extra quantity of steam to be delivered to the fabric through steam vents in the soleplate 12. Both of these functions are performed in a manner well known to those skilled in the art and particularly as disclosed in U.S. Pat. No. 4,398,364 to Augustine, et al. which is also assigned to the assignee of this application.
The interior 54 of the handle 50 encloses a printed circuit board 70 having an electronic circuit mounted thereon. Referring now to FIG. 4, a conventional alternating current line connector 72 is shown therein which is connected to a power control switch 74. Switch 74 in this case is a single pole rocker type switch, although other types of switches may be substituted therefor by one skilled in the art. Alternating current, received from a suitable source of alternating current such as a 110 volt AC wall socket, is fed from the connector 72 through a lead 76 to the rocker switch 74. The rocker switch 74 is, in turn, connected to a lead 78 which feeds current through a 22 kilohm resistor 80. The resistor 80 acts as a current limiter to deliver reduced potential AC to a half wave rectifying diode 82 connected in series with it. The diode 82 is, in this embodiment, a 1N4004 diode. The diode 82 is connected to a lead 84 which delivers half wave rectified DC to a combination filter-voltage regulator 86. The filter-voltage regulator 86 includes a zener diode 88, in this embodiment a 1N5242B 12 volt one-half watt zener diode, which is connected in parallel with a 22 microfarad 16 volt electrolytic capacitor 90. The combination of the zener diode 88 the electrolytic capacitor 90 provides a clipped, voltage regulated DC signal having a potential of +12 volts at the lead 84.
A lead 94 is also connected to the filter-voltage regulator 86 opposite the lead 84 and comprises a ground bus for other portions of the circuit.
A mercury switch 96 is connected between the lead 84 and a 47 kilohm resistor 98. Resistor 98 is connected to lead 94. The mercury switch 96, as will be described in more detail hereinafter, senses both the state of motion and the attitude or orientation of the electronic pressing iron 10 and provides an output signal representative thereof to other portions of the circuit.
A programmable timer 100, in this embodiment a Motorola MC14541B programmable timer, is connected at its V DD pin 102 to receive the 12 volt potential from the lead 84 which is delivered to the pin 102 through a lead 106. A parallel lead 108 also delivers the positive 12 volt potential to a Q/Q select pin 110. An auto-reset pin 112, a V ss pin 114, a cycle mode pin 116 and a modulo divider B pin 118 are all connected by a lead 120 to the ground bus 94 to maintain the pins 112 through 118 at zero volts. The resistor 98 is connected through a lead 122 to a frequency doubler cicuit 119 including a 0.01 microfarad capacitor 124, which is connected to a 560 microhenry coil 125. The coil 125 is connected by a lead 123 to resistor 134 and is also connected to the base of a transistor 127. A resistor 126 is connected to the collector of transistor 127 and also to the reset pin 137 of the programmable timer. Resistors 126 and 134 are connected to the + 12 volt potential at lead 84 by a lead 129. In combination all of these components provide reset pulses to the programmable timer 100, as will be seen hereinafter. A 220 picofarad capacitor 136 is connected between the master reset pin 137 and the ground bus 94. The lead 122 is also connected to a 220 kilohm resistor 128 which is connected to a modulo divider A pin 130. The modulo divider A pin 130 is also connected to the ground lead 94 through a 220 picofarad capacitor 132.
A clock circuit 140 consisting of a 2.2 megohm resistor 142, a 0.047 microfarad capacitor 144 and a 3.9 megohm resistor 146 is connected to the programmable timer 100 and generates an approximately 4 Hz oscillator signal which is supplied to a lead 148 connected to the resistor 142. A 220 picofarad noise bypass capacitor 150 is connected between the resistor 146 and the ground bus 94. The resistor 142 is also connected to an R tc pin 152 of the programmable timer 100. The capacitor 144 is connected to a C tc pin 154 of the programmable timer 100. The resistor 146 and capacitor 150 are connected to an R s pin 156 of the programmable timer 100. An output lead 158 is connected to a Q pin 160 of the programmable timer 100.
In operation, DC voltage to operate the programmable timer 100 is supplied to the V DD pin 102 and V SS pin 114 of the programmable timer 100. The modulo divider B pin 118 is latched low, as is the cycle mode pin 116 and the auto reset pin 112. The Q/Q select pin 110 is latched high to select Q output pin 160 as being set high after reset. Once the programmable timer 100 is energized, the timing network 140 generates the 4 Hz clock signal, which is fed to the programmable timer 100 and is also fed through the lead 148 to a 47 kilohm resistor 162.
When the electronic pressing iron 10 is positioned on its heel rest, the mercury switch 96 remains open so that the resistor 98 and the lead 122 are held substantially at ground potential. Therefore, the pin 130 is also at ground potential selecting a high modulus which will cause the programmable timer 100 only to generate an output signal indicative of a time out event when the mercury switch 96 is not closed for sixteen minutes. At the end of the sixteen minutes, the Q output at the pin 160 would switch low, pulling low a resistor 164 which is connected to pin 160 by the lead 158. When the resistor 164 has a low voltage, a transistor 166, which is connected at a base 168 to resistor 164, switches nonconducting. When the transistor 166 switches nonconducting, its collector 170, which is connected to a gate 172 of a silicon controlled rectifier 174, would be allowed to float at a potential of the R tc pin 152 so that the 4 Hz clock pulses would switch the SCR 174 on four times a second, allowing current to flow through the SCR 174 and through a positive temperature coefficient heater 176 of a thermal relay 178. This would cause a bimetallic thermostat 180 of the thermal relay 178 to open, interrupting electric power flowing through the thermal relay and the electric heating element 16. In the preferred form of the invention, the thermal relay is of the snap acting type.
In the event that the electronic pressing iron 10 is in the soleplate down position and is not moving, the mercury switch 96 remains closed, causing the pin 130 to reach approximately 12 volts which sets the modulo divider pins so that the programmable timer 100 times out more rapidly. When the mercury switch 96 remains closed continuously for 30 seconds, the Q output pin 160 would drop low, switching the SCR 174 on, and allowing alternating current to flow through the PTC heater 176 to open the thermostat 180.
In the event that the electronic pressing iron 10 is moving, whether the soleplate 12 is down or up, the mercury switch 96 will be opening and closing as mercury within the switch is accelerated by the changing motion of the electronic pressing iron 10. The pulses from the opening and closing of the mercury switch 96 are applied to the frequency doubling circuit 119 consisting of capacitor 124, inductor 125, resistors 134 and 126, and transistor 127. Resistor 126 applies the +12 volt potential to reset pin 137, causing the programmable timer 100 to reset and cease timing. The transistor 127 is biased into its conducting state by resistor 134, causing it to shunt the potential applied to reset pin 137, thus allowing programmable timer 100 to function in its normal timing mode.
When the mercury switch 96 is initially closed, current will attempt to flow through capacitor 124 and inductor 125. The inductor 125 will momentarily oppose this current, reverse biasing transistor 127 off and, therefore allowing the reset pin 137 to receive the +12 volt potential. When the mercury switch 96 is opened, capacitor 124 will discharge through resistor 98, again momentarily reverse biasing transistor 127 off and enabling the +12 volt potential to appear on reset pin 137. Thus it can be realized that each time the electronic pressing iron 10 is moved, causing mercury switch 96 to either open or close, the programmable timer 100 is reset, thereby preventing it from timing out and disabling the iron in the manner to be described hereinafter.
Thus, the combination of the mercury switch 96, together with the programmable timer 100 as configured, provides a motion and attitude sensing apparatus which is capable of interrupting current through the electrical heating element 16. One of the particular advantages of the instant circuit lies in the use of the thermal relay 178 wherein the PTC heater 176 is connected to the snap acting thermostat 180, as may best be seen in FIGS. 2 and 2A. The PTC heater 176 is connected to the snap acting thermostat 180 by an epoxy bonding compound 182 which is both electrically conductive and heat conductive or alternatively by a tin-lead solder. A shrink fit plastic sleeve 184 surrounds the PTC heater 176 and the snap acting thermostat 180 to secure better the PTC heater 176 to the snap acting thermostat 180.
It may be appreciated that when the PTC heater 176 is energized, heat flows to a bimetal moving member 186 of the snap acting thermostat 180 which is normally in electrically conductive contact with a fixed electrical contact 188. As the bimetal member 186 heats up, it moves away from the contact member 188 and travels into an off position whereby the alternating current flowing through the thermal relay 178 is interrupted. It may also be appreciated that the thermal relay 178 can handle large amounts of current while occupying a relatively small amount of space. Furthermore, no special current conditioning measures are necessary to be taken for the PTC heater as might be needed for a conventional solenoid of a direct current relay.
An indicating leg 190 is connected in parallel with the silicon controlled rectifier 174. When the rocker switch 74 is open, no current flows through the indicating leg 190, which consists of a diode 192, an 18 kilohm resistor 194 and a neon lamp 196. When the rocker switch 74 is closed and current flows through the circuit, as long as the silicon controlled rectifier 174 remains nonconducting, maintaining the electronic heating element 16 in an enabled mode, a junction 198 of the silicon controlled rectifier anode and the lead 190 remains at a relatively high voltage providing sufficient potential drop across the neon lamp 196 to illuminate it continuously. If the silicon controlled rectifier 174 is switched conducting, the potential at the junction 198 drops below the magnitude at which the potential drop across the neon lamp 196 can illuminate it. It may be appreciated that the relatively large resistance 194 prevents significant current flow through the PTC heater when the silicon controlled rectifier 174 is off, thus avoiding substantial heating of the PTC heater and false opening of the thermal relay 178.
Thus, it may be appreciated that all of the circuit components including the motion and attitude sensing switch 96, the programmable timer 100 and the thermal relay 178 are mounted compactly inside the handle 50. In addition, the thermal relay 178 provides a compact switching element which can be used to control the flow of electric current through the electric heating element 16.
In the disclosed embodiment, the electronic circuitry remains energized after the thermal relay 178 has been actuated to disable the power to the heating element 16. As an alternative embodiment, the electronic circuit could be connected in parallel with the heating element 16 and the thermostat 18 and in series with the switch 180 so that the electronic circuit would be disabled along with the heating element 16 when the relay 178 opened. In this embodiment, a manual reset would be required for the thermal relay 178 so that the electronic circuit could be powered up along with the heater 16 after conditions had caused the relay 178 to open.
While there has been shown and described several embodiments of the present invention, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the invention in its broadest aspects, and it is, therefore, contemplated in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the present invention. | An electronic pressing iron having a soleplate and a housing connected to the soleplate is disclosed herein. An electric resistance heating element is mounted in the soleplate for receipt of an alternating current from a suitable source. A temperature control thermostat is connected in series with the electric heating element and is mounted in good heat conduction relationship with the soleplate to control the temperature thereof. A motion and attitude sensing switch is mounted in a handle of the housing and provides a motion signal to a programmable timer also mounted in the handle. A thermal relay mounted in the handle is connected to the programmable timer to receive a time out signal therefrom. When the electronic pressing iron is switched on and is stationary with its soleplate oriented horizontally, for a period of thirty seconds, the programmable timer signals the thermal relay which interrupts the electric current flowing through the heating element. When the electronic pressing iron is resting on its heel rest and is not moved for a period of sixteen minutes, the programmable timer also signals the thermal relay to interrupt electric current flowing through the electric heating element. | 3 |
FIELD OF THE INVENTION
The present invention relates to a device for storing pipes, especially in vertical position.
BACKGROUND OF THE INVENTION
In connection with drilling for oil and gas there are heavy requirements as regards capacity and safety in respect of pipe handling. There exist a plurality of various handling systems on today's market, and the present invention has for an objective to provide an improved device for storing pipes whereby the handling and storing operations can be effected in a rational and appropriate manner.
PRIOR ART
In connection with the stacking of pipes vertically in a derrick, there are specifically two types which will be discussed in the following.
A first method is to the fact of positioning the pipes between stationary parallel fingers. This will give a good utilization of the storage area, but there are required four movements of the pipe handling machine.
A second method is to the fact of arranging the fingers in a star-shaped pattern, such that the pipe handling machine itself can reside in the middle thereof. Thereby is achieved one movement less than in the first method by fetching or storing pipes in the pipe storage. However, this second method entails a poor utilization of the storage area, at the same time as the arms of the handling machine must be pulled in when turning said machine.
BRIEF DISCLOSURE OF THE INVENTION
The object of the present invention is to provide a device wherein the advantages of better area utilization in relation to said first method, and the advantages of a direct and rapid movement in relation to said second method, are combined in a novel and expedient arrangement. This is substantially achieved according to the invention in that the device comprises fingers which are arranged as partly or approximately fully circle-shaped configurations.
In a device of the type as stated in the preamble, this is consequently, according to the invention, characterized in that it comprises an upper supporting means having one or more curved fingers for providing arch-shaped storage paths for pipes.
Appropriately, the device can be designed so that the distance between the curved fingers can be adjusted, which entails that the storage paths between said curved fingers can be adjusted in width as regards the pipe size to be used.
According to the invention there is provided a device which by co-operation with a suitable pipe handling machine will operate more rapidly as regards the stacking or fetching of pipes, because, specifically in relation to said second method, it is not necessary to pull in the scissor arms of the pipe handling machines for allowing turning of the pipe handling machine to the opening of the selected storage path.
Still another advantage of the present device is to the fact that it may comprise an arbitrary number of sets of curved fingers, appropriately arranged around a pipe handling machine, and having appropriate pipe handling openings therebetween, for thereby enabling operation towards one, two or more well centres.
Further features and advantages of the present invention will appear from the following description taken in conjunction with the appending drawings.
BRIEF DISCUSSION OF THE DRAWINGS
FIG. 1 is a schematical side view illustrating the main elements of a first embodiment of a device for handling pipes, according to the invention.
FIG. 2 is a plan view illustrating a first embodiment of the device according to the invention, especially adapted to a simple derrick solution, respectively an operation towards one well centre.
FIG. 3 is a plan view illustrating a second embodiment of the device according to the invention, especially related to a double derrick solution, respectively an operation towards two different well centres.
DESCRIPTION OF EMBODIMENTS
In FIG. 1 there is schematically illustrated a side view of the main elements included in a drilling system, wherein the present device for storing pipes according to the present invention, can be applied.
In FIG. 1 reference numeral 1 indicates a pipe handling machine which is designed substantially cylindrical and adapted to turn around a central centre axis C. The pipe handling machine 1 is pivotably supported in a bottom bearing 2 and arranged pivotable in an upper bearing 3, which can be built together with an upper finger drilling top structure 4, which will be discussed further with reference to FIG. 2.
The pipe handling machine 1 comprises a lower scissor arm 5a which at its outer end carried a lower claw 6a adapted to clamp around a pipe 7 and by means of a lifting mechanism 8 to lift and lower the pipe 7, and then through an upper claw 6b which is adapted to close around the pipe 7 for providing a guide for the latter, at the same time as the upper claw 6b is located outermost on the upper scissor arm 5b. The upper scissor arm 5b is manoeuvred by means of an upper mechanism 9.
In FIG. 1 there is illustrated by a dashed line a derrick assembly 10, in which derrick assembly there may be included one, two or more well centres with which the pipe handling machine 1 can communicate in an appropriate manner, and specifically in an expedient manner by using the device according to the present invention.
In FIG. 2 there is illustrated a first embodiment of a device for storing pipes, according to the invention, and in this Figure there is recognized the finger drilling top structure 4 which can be built together with, respectively comprise a supporting beam 11, provided with a longitudinally extending track 12 within, according to the invention, there are provided one or more curved fingers 13a . . . 13n in a first set 14 and a second unit of curved fingers 15a . . . 15n arranged in a second set 16. It is to be understood that the curved lingers are substantially arranged with the same radius of curvature, which means that between the respective curve fingers there will be defined correspondingly curved storage paths 17x and 17y.
By letting the curved fingers 13a . . . 13n and 15a . . . 15n, respectively, be arranged displaceable in said track 12 in the supporting beam 11, the width between said fingers can be adjusted, such that the width of the storage paths 17x and 17y, respectively, can be adjusted for adaption to the desired pipe dimension, for example pipes 7a of a lesser dimension in the storage path 17x, and for example pipes 7b of a larger dimension in the storage path 17y.
In FIG. 2 it is illustrated that the respective curved fingers are arranged in two sets 14 and 16, respectively, which means that the illustrated embodiment of the device encloses in a semi-ring-structure around the upper portion of the previously discussed pipe handling machine 1, and will through a pipe handling opening 18 between said two sets enable operation towards one well centre. Consequently, in said pipe handling opening 18 the upper scissor arm 5b with its upper claw 6b will be able to pass a pipe 7' to an appropriate position in front of the mouth of a storage path 17x and 17y, and by an appropriate turning of the claw 6b through an appropriate turning element 19 passing said pipe 7' in position in the storing device, or fetch a corresponding pipe therefrom towards the well centre.
In FIG. 3 there is illustrated a second embodiment of a device for storing pipes according to the invention, wherein the pipe handling machine is designated by reference numeral 101 and the finger drilling top structure is designated by reference numeral 111, this embodiment of the finger drill top structure 111 being adapted for four set of curved fingers, namely a first set 114 comprising the finger 113a . . . 113n, and a second set 116 comprising fingers 115a . . . 15n, which fingers at their one end are attached in a channel 112 for mutual displacement and thereby adjustment of the mutually arranged storage paths 17x, 17y.
Said two mentioned sets 114 and 116 will therebetween define a pipe handling opening 118 wherein the upper scissor arm 115b of the pipe handling machine 101 can be brought forward and rearward for fetching and storing of pipes, respectively.
Correspondingly, on the diametrically opposite side of the finger drill top structure 112 there is provided a third set 114 with curved fingers 213a . . . 213n and a fourth set 216 comprising curved fingers 215a . . . 215n.
The four sets which are curved in a substantially full ring configuration about the rotation axis C for the pipe handling machine 101, will through their respective pipe handling openings, respectively 118 between the two first sets 114 and 116 and the pipe handling opening 218 between the third set 214 and the fourth 216, be able to operate towards two different well centres, arranged substantially diagonally in relation to each other in relation to said pipe handling machine 101.
By arranging an upper supporting means with one or more curved fingers, as this is suggested according to the present invention, there is achieved a device providing a plurality of arch-storage paths for pipes between said fingers, which means a great improvement as regards the utilization of storage area and the reduction in handling time.
Since said fingers are arranged for mutual in-between adjustment there may be provided storage paths having different widths adapted to the pipe dimensions in question in the various types of drilling.
During operation it is only necessary to pull in the scissor arms on the pipe handling machine so far that the respective claws of the scissor arms are flush with the mouth of the selected storage path, whereafter or at the same time as said claws are rotated to correct position, it being for the storage or the fetching of the selected pipe. | The present invention relates to a device for storing pipes, especially in vertical position, and for the purpose of providing an improved structure wherein a better utilization of the storage area is achieved, the pipe handling can be effected in a faster and safer manner, and wherein the device can more easily be adjusted for various pipe dimensions, it is according to the present invention suggested that the device comprises an upper supporting means (11; 111) having one or more curved fingers (13a; 113a) for providing arch-shaped storage paths (17x, 17y; 117x, 117y) for pipes (7; 7'). | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of Application Ser. No. 038,680, filed Apr. 15, 1987, entitled "Process for the Preparation of Chromogenic Cryptahemispherands", now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a class of compounds generally known as chromogenic cryptahemispherands useful in the measurement of ions and more particularly, to a process for the preparation of such chromogenic cryptahemispherands.
2. Description of the Prior Art
Certain terms used in the present discussion should be defined to assure that the reader is of the same mind as the author as to their respective meanings. Thus the following definitions are provided to clarify the scope of the present invention.
The term "ionophore" includes, broadly, molecules capable of forming a complex with an ion in solution. For example, the cyclic polypeptide, valinomycin, binds selectively to potassium ions in solution to form a cationic complex. Also included in this term are podands, corands, cryptands, hemispherands, cryptahemispherands and spherands.
A "podand" is an organic linear compound containing donor or receptor atoms which has the capacity of associating with positively charged ions to form complexes.
The term "corands" refers to monocyclic compounds which contain electron donor atoms or acceptor atoms, which are electron rich or deficient, and which are capable of complexing with particular cations or anions because of their unique structures. Because of the unique sizes and geometries of particular corands, they are adaptable to complexing with various ions. In so complexing, the electron rich atoms, such as the oxygens in a corand, become spacially oriented towards the electron deficient cation. The carbon atom segments of the cycle are simultaneously projected in a direction outwards from the ion. Thus, the resultant complex is hydrophilic in the center, but is relatively hydrophobic at its perimeter.
"Cryptands" refers to polycyclic analogs of the corands. Accordingly, they include bicyclic and tricyclic multidentate compounds. In the cryptands, the cyclic arrangements of donor atoms is three dimensional in space, as opposed to the substantially planar configuration of the corands. A cryptand is capable of virtually enveloping the ion in three dimensional fashion and, hence, is capable of strong bonds to the ions in forming the complex. As with the corands, the donor atoms can include such atoms as oxygen, nitrogen and sulfur. The term "hemispherands" refers to macrocyclic or macropolycyclic ionophore systems, whose cavities are partially preorganized for binding by the rigidity of the hydrocarbon support structure and the spatial and orientational dictates of appended groups.
The designation "cryptahemispherand" was given by Donald J. Cram in 1986 (Cram, et al., J. Am. Chem. Soc., 108 pp. 2998-3005 (1986)) to the class of macrobicyclic compounds which show an extraordinary propensity for complexation of alkali metal cations. Cryptahemispherands combine the partially preorganized cavity features of the hemispherands, but contain multiple other ligand-gathering features of the cryptands. The generic structure of a cryptahemispherand is depicted, infra, as structure (I). ##STR2## wherein: R is hydrogen, alkyl, alkylidene, alkenyl, allyl, aryl or benzyle;
m is 0 to about 2; and
n is 0 to about 2;
Certain compounds were described in the literature prior to Cram, et al. supra, which are capable of not only behaving as ionophores by forming cation complexes, but also, when complexed, exhibit a detectable formation of or change in color.
Thus, experiments were published in 1977 whereby chromogenic moieties were covalently attached to ionophores to achieve a color change response to potassium (Takagi, et al., Analytical Letters, 10(3), pp. 1115-1122 (1977)). There it is taught to couple covalently a chromogenic moiety such as 4-picrylamino to an ionophore such as benzo-15-corand-5. Moreover, U.S. Pat. No. 4,367,072 mentions many corands, cryptands and podands covalently substituted with a chromogenic group, such as ##STR3##
Yet another reference, German Offenlegungschift No. 3202779, published Aug. 4, 1983 discloses a chromogenic cryptand structure.
Although the synthesis of non-chromogenic cryptahemispherands have been described by Cram, et al., incorporation of a chromogenic moiety into the cryptahemispherand structure requires different synthetic strategy and has not been described before.
SUMMARY OF THE INVENTION
The invention relates to a process in which a variety of chromogenic cryptahemispherands of the general structure (I) may be synthesized in a direct fashion. The process is a nine-reaction preparation of cryptahemispherands bearing a chromogenic group attached to the partially preorganized moiety. The procedure of the present invention allows preparation of preferred chromogenic cryptahemispherands of the general formula: ##STR4## wherein: R, same or different, is hydrogen, lower alkyl, lower alkylidene, lower alkenyl, allyl, aryl or benzyl;
R', same or different, is lower alkyl, lower alkylidene, lower alkenyl, allyl, aryl or benzyl;
R", same or different, is hydrogen, lower alkyl, lower alkylidene, lower alkenyl, allyl, aryl or benzyl;
Z is halogen;
Y is an electron withdrawing group, e.g., CN, NO 2 , CF 3 , COOR;
m is 1 to 3;
n is 1 to 3;
a is 1 to 3;
b is 1 to 3;
k is 1 to 3;
l is 1 to 3; and
x is 2 to 4.
The term "lower alkyl", as used in the present disclosure includes an alkyl moiety, substituted or unsubstituted, containing 1-4 carbon atoms. Included in the meaning of lower alkyl are methyl, ethyl, n-propyl, isopropyl, n-butyl and tert-butyl.
"Lower alkylidene" is used herein in the same context as "lower alkyl", but designates an alkylene group (i.e., a divalent alkyl) having 1-4 carbon atoms. The term lower alkylidene includes, but is not limited to, methylene, ethylidene, n-propylidene, iso-propylidene, n-butylidene, sec-butylidene and tert-butylidene.
The term "aryl" includes substituted or unsubstituted aryl moieties containing 6-12 carbon atoms, such as, for example, phenyl, tolyl, butyl phenyl, naphthyl ethyl, chlorophenyl, nitrophenyl and carboxyphenyl.
"Lower alkenyl" as used herein designates an lower alkenyl moiety, substituted or unsubstituted, having 1 to 4 carbon atoms and includes, for example, ethenyl, 1-propenyl, 2-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, isobutenyl, and tert-butenyl.
The above moieties may be unsubstituted or substituted as noted providing any such substituents do not interfere with the operation or functioning of the presently claimed invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the appended drawing, which is presented to further describe the invention, and to assist in its understanding through clarification of its various aspects, FIGS. 1A and 1B describe a reaction pathway for synthesizing preferred chromogenic cryptahemispherands of the general structure (II).
DETAILED DESCRIPTION OF THE INVENTION
The chromogenic cryptahemispherand of the general structure (II) can be synthesized in accordance with the reaction pathway depicted in FIGS. 1A and 1B and described in detail below.
Preparation of Known Intermediate Compounds 2 and 6
The 2-bromo-6-(hydroxymethyl)-methylphenol 2 used in the following preparation was obtained from commercially available 2-bromo-4-methylphenol 1 by the method described in the article by Cram, et al., J. Am. Chem. Soc., 106 pp. 4977-4987 (1984).
The 4-nitro-2,6-dimethylanisole 6 was prepared from commercially available 4-nitro-2,6-diiodophenol 5 by the method described in the article by Block, et al., J. Am. Chem. Soc., 64 pp. 1070-1074 (1942).
Both of the articles are incorporated herein by reference.
Preparation of Compound 3
To a solution of 2 (23.4 g, 107.8 mmol) in 600 ml of THF under Ar at 0° C. was added 15.2 g (381 mmol) of 60% NaH. After warming to room temperature, 45.7 g (360 mmol) of dimethyl sulfate was added and the mixture was refluxed 18 h, cooled to 0° C. and methanol was added to decompose the excess NaH. The solvent was removed in vacuo to give a crude product which was dissolved in 100 ml of CHCl 3 and brine was added. The organic layer was separated, dried (MgSO 4 ) and evaporated. The residue was purified on a silica gel column (flash) with benzene-cyclohexane (1:4→1:1) to afford 23.7 g (90%) of 3 as a colorless liquid.
The 1 H NMR spectrum (CDCl 3 ) gave absorptions at δ2.29 (s, ArCH 3 , 3H), 3.43 (s, OCH 3 , 3H), 3.82 (s, OCHHD 3, 3H), 4.48 (s, ArCH 2 , 2H), 7.14 (d, ArH, 1H) and 7.30 (d, ArH, 1H). Calcd. for C 10 H 13 BrO 2 (percent): C, 49.00; H, 5.35. Found (percent): C, 49.11; H, 5.34.
Preparation of Compound 4
To a solution of 3 (13.0 g, 53 mmol) in 200 ml of THF under Ar at -78° C. was added 22.5 ml of 2.4M n-BuLi (hexane). After stirring for 8 min, the lithiation solution was cannulated over 15 min into 48.0 g (460 mmol) of trimethyl borate in 125 ml of THF at -78° C. The mixture was stirred 30 min at -78° C. over 45 min, diluted with 400 ml of 2N HCl, and stirred 1 h at 25° C. Ether (250 ml) was added, the mixture was stirred 6 h at 25° C., and the layers were separated. The aqueous layer was extracted with fresh ether (3×100 ml). The combined ether extracts were extracted with 3N aqueous NaOH (4×100 ml). The base extracts were cooled to 5° C. and acidified to pH1 with concentrated HCl. Extraction of the aqueous solution with ether (3×100 ml) gave after evaporation of the solvent (room temperature, vacuum) 10.5 g (95%) of a colorless viscous oil 4 which solidified during storage at -5° C. and was used without further purification.
The 1 H NMR spectrum ((CD 3 ) 2 CO) gave absorptions at δ2.29 (s, ArCH 3 , 3H) 3.38 (s, OCH, 3H), 3.80 (s, OCH 3 , 3H), 4.45 (s, ArCH 2 , 2H), 7.29 (d, ArH, 1H) and 7.52 (d, ArH, 1H).
Preparation of Compound 7
To a mixture of 6 (4.00 g, 9.9 mmol), and 4 (5.00 g, 24.0 mmol) in 60 ml of toluene and 15 ml of ethanol was added under Ar 30 ml of 2M aqueous Na 2 CO 3 . To this vigorously stirred two-phase mixture was added 0.60 g (0.52 mmol) of tetrakis (triphenylphosphine)palladium (0) and the mixture was refluxed for 45 h. The layers were separated and the organic layer was dried (MgSO 4 ), evaporated and the residue was column chromatographed on alumina with benzene, and benzene-ethyl acetate (20:1) to give 4.44 g (93%) of 7 as a very viscous, pale yellow oil.
The mass spectrum (70 eV) gave the expected molecular ion at m/e 481. The 1 H NMR spectrum (CDCl 3 ) gave absorptions at δ2.36 (s, ArCH 3 , 6H), 3.30 (s, OCH 3 , 3H), 3.47 (s, OCH 3 , 6H), 3.49 (s, OCH 3 , 6H), 4.54 (s, ArCH 2 , 4H), 7.12 (d, ArH, 2H), 7.28 (d, ArH, 2H) and 8.25 (s, ArH, 2H).
Calcd. for C 27 H 31 NO 7 (percent): C, 67.35, H, 6.49. Found (percent): C, 67.27; H, 6.38.
Preparation of Compound 8
To a mixture of 7 (4.65 g, 9.7 mmol) in 175 ml of benzene and 175 ml of 1N NaOH under Ar was added 4.65 g (23.7 mmol) of iron pentacarbonyl. The mixture was stirred for 18 h at room temperature, 500 ml of benzene was added, and the benzene layer was separated. The aqueous layer was extracted with benzene (2×100 ml), the combined organic layers were filtered through Celite (twice), dried (K 2 CO 3 ), filtered and evaporated to a 70 ml volume and a residue was column chromatographed on silica gel (flash) with petroleum ether-ethyl acetate (3:1→1:1) to give 2.88 g (66%) of 8 as a heavy, pale yellow oil which solidified during storage.
The mass spectrum (70 eV) gave the expected molecular ion at m/e 451. The 1 H NMR spectrum (CDCl 3 ) gave absorptions at δ2.33 (s, ArCH 3 , 6H), 3.14 (s, OCH 3 , 3H), 3.45 (s, OCH 3 , 6H), 3.51 (s, OCH 3 , 6H), 4.54 (s, ArCH 2 , 4H), 6.70 (s, ArH, 2H), 7.13 (s, ArH, 2H) and 7.19 (s, ArH, 2H).
Calcd. for C 27 H 33 NO 6 (percent): C, 71.82; H, 7.37. Found (percent): C, 71.75; H, 7.56.
Preparation of Compound 9
A mixture of 8 (2.75 g, 6.1 mmol), picryl chloride (2.00 g, 8.1 mmol) and NaHCO 3 (0.51 g, 6.1 mmol) in 325 ml of methanol under Ar at room temperature was stirred overnight, the solvent was removed in vacuo (room temp.) and a residue was dissolved in CHCl 3 --H 2 O (110 ml of each). The chloroform layer was dried (MgSO 4 ), concentrated to 10 ml and column chromatographed on silica gel (flash) with petroleum ether-ethyl acetate (2:1) to give 3.82 g (95%) of 9 as a red foam.
The mass spectrum (70 eV) gave the expected molecular ion at m/e 662. The 1 H NMR spectrum (CDCl 3 ) gave absorptions at δ2.35 (s, ArCH 3 , 6H), 3.23 (s, OCH 3 , 3H), 3.46 (s, OCH 3 , 6H), 3.53 (s, OCH 3 , 6 H), 4.53 (s, ArCH 2 , 4H), 7.09-7.25 (m, ArH, 6H), 9.08 (s, ArH, 2H) and 10.29 (s, NH, 1H).
Calcd. for C 33 H 34 N 4 O 11 (percent): C, 59.81; H, 5.17. Found (percent): C, 59.86; H, 5.36.
Preparation of Compound 10
Anhydrous HBr was bubbled into a solution of 9 (2.05 g, 3.1 mmol) in 650 ml of CHCl 3 for 10 min. After stirring an additional 10 min in the solution was poured into 800 ml of water and the mixture was stirred over 30 min. The organic layer was dried (MgSO 4 ), concentrated to 10 ml and column chromatographed on silica gel with CH 2 Cl 2 to afford 1.79 g (75%) of 10 as a red glass.
The 1 H NMR spectrum (CDCl 3 ) gave absorptions at δ2.34 (s, ArCH 3 , 6H), 3.23 (s, OCH 3 , 3H), 3.62 (s, OCH 3 , 6H), 4.61 (s, ArCH 2 , 4H), 7.09-7.24 (m, ArH, 6H), 9.09 (s, ArH, 2H) and 10.30 (NH, 1H).
Calcd. for C 31 H 28 Br 2 N 4 O 9 (percent): C, 48.07; H, 3.71. Found: C, 48.70; H, 3.71.
Cryptahemispherand 11
To a vigorously stirred solution containing 0.49 g (6.6 mmol) of anhydrous Li 2 CO 3 in 100 ml of CH 3 CN was added over a period of 20 h 1,7-dioxa-4,10-diazacyclododecane (0.022 g, 1.25 mmol) in CH 3 CN (27 ml) and dibromide 10 (0.95 g, 1.25 mmol) in 27 ml of CH 3 CN at reflux. After addition was completed, reflux was continued for additional 15 h, then the solvent was removed in vacuo (25° C.) and the residue was chromatographed on a silica gel column with CH 2 Cl 2 --CH 3 OH (95:5) to afford 0.54 g (56%) of an orange foam which is a complex of 11 with lithium bromide.
The 1 H NMR spectrum (CDCl 3 ) showed absorptions at δ2.36 (s, ArCH 3 , 6H), 2.53 (s, OCH 3 , 3H), 2.36-2.72 (m, NCH 2 , 8 H), 3.12-4.19 (m, OCH 2 , NCH 2 , OCH 3 , 18H), 7.05 (d, ArH, 2H), 7.14 (d, ArH, 2H), 7.28 (s, ArH, 2H) and 9.09 (s, ArH, 2H).
The cryptahemispherand 11 has the structure shown in FIG. 1 wherein n is 0.
Cryptahemispherand 12
To a vigorously stirred solution containing 0.85 g (8.0 mmol) of anhydrous Na 2 CO 3 in 120 ml of CH 3 CN was added over a period of 20 h Kryptofix®22 (0.42 g, 1.6 mmol) in CH 3 CN (35 ml) and dibromide 10 (1.22 g, 1.6 mmol) in CH 3 CN (35 ml) at reflux. After addition was completed, reflux was continued for additional 15 h, then the solvent was removed in vacuo (25° C.) and the residue was chromatographed on a silica gel column with CH 2 Cl 2 --CH 3 OH (95:5→90:10) to give 1.30 g (84%) of 12 as a dark red powder. The product is a complex of 12 with NaBr.
The 1 H NMR spectrum (CDCl 3 ) showed absorptions at δ2.36 (s, ArCH 3 , 6H), 2.84 (s, OCH 3 , 3H), 3.48 (s, OCH 3 , 6H), 2.18-4.10 (m, NCH 2 , OCH 2 , 24H), 2.67 (d, ArCH 2 N, 2H), 4.20 (d, ArCH 2 N, 2H), 7.03 (d, ArH, 2H), 7.12 (d, ArH, 2H), 7.17 (s, ArH, 2H) and 9.09 (s, ArH, 2H).
The cryptahemispherand 12 has the structure shown in FIG. 1B wherein n is 1.
The invention has been particularly described with reference to the preparation of compounds 11 and 12. It is to be understood that all the other compounds falling within formula II as defined herein, can be made in essentially the same way by choosing the appropriate reactant(s) at each state of the process.
It should be understood by those skilled in the art that various modifications may be made in the present invention without departing from the spirit and scope thereof as described in the specification and defined in the amended claims. | The invention relates to a process in which a variety of cryptahemispherands bearing a chromogenic group attached to the partially preorganized moiety may be synthesized. The procedure of the present invention allows preparation of preferred chromogenic cryptahemispherands of the general formula: ##STR1## wherein: R, is same or different, is hydrogen, lower alkyl, lower alkylidene, lower alkenyl, allyl, aryl, or benzyl;
R', same or different, is hydrogen, lower alkyl, lower alkylidene, lower alkenyl, allyl, aryl, or benzyl;
R", same or different, is hydrogen, lower alkyl, lower alkylidene, lower alkenyl, allyl, aryl, or benzyl;
Z is halogen;
Y is an electron withdrawing group, e.g., CN, NO 2 , CF 3 , COOR;
m is 1 to 3;
n is 1 to 3;
a is 1 to 3;
b is 1 to 3;
k is 1 to 3;
l is 1 to 3; and
x is 2 to 4. | 2 |
RELATED APPLICATIONS
The present application claims the benefit of the filing date of European Patent Application No. 07018308.2 filed Sep. 18, 2007 and of PCT-Application No. PCT/EP2008/062349 filed Sep. 17, 2008, the disclosures of which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to an architecture, in particular a home agent being placed in a visited connectivity service network in order to separate a data traffic path to a home connectivity service network and a data traffic path to the internet in order to minimise a number of hops and delay times.
BACKGROUND OF THE INVENTION
In the Worldwide Interoperability for Microwave Access (WiMAX) Forum, network reference architectures based on the IEEE802.16e broadband wireless access technology are defined. The WiMAX standard defines beside an access service network (ASN), a connectivity service network (CSN). The access service network comprises, for example, a base station (BS), in particular a radio base station and an access service network gateway (ASN-GW). The connectivity service network provides services like authentication, authorisation and accounting (AAA), dynamic host configuration protocol (DHCP) and a mobile internet protocol home agent (MIP HA). The home agent usually also constitutes an internet protocol router. Via the connectivity service network a terminal, for example, a mobile station (MS) or a subscriber station (SS) may have an access to the internet or to services which are specific for the respective operator, like, for example, an internet protocol multimedia subsystem (IMS).
A WiMAX roaming architecture comprises, for example, an access service network, a visited connectivity service network (V-CSN) and a home connectivity service network (H-CSN). In case of roaming, the access service network is connected to the visited connectivity service network, but not to the home connectivity service network. However, usually in the home connectivity service network the user specific data is managed, but not in the visited connectivity service network. Therefore, if a terminal or a mobile station accesses to an access service network, the mobile station will be authenticated by an authentication, authorisation and accounting server of the home connectivity service network, the home authentication, authorisation and accounting (H-AAA) server. In this case the authentication, authorisation and accounting server in the visited connectivity service network, the visited AAA (V-AAA) server only serves as an AAA proxy server. WiMAX uses for authentication an extensible authentication protocol (EAP) which may be transported within the AAA protocol corresponding to RADIUS OR DIAMETER. According to the WiMAX standard, the user data will be transported between the access service network and the connectivity service network in a mobile internet protocol (MIP) tunnel. The MIP home agent will be localised in the connectivity service network. During the MIP registration an authentication of the subscriber with the home AAA server takes place, which home AAA server also provides the key or key material to the home agent during authentication. The protocol between the home agent and the home AAA server is, again, RADIUS OR DIAMETER. In case of roaming, the WiMAX standard defines that the home agent is provided either in the home connectivity service network or in the visited connectivity service network. In case the home agent is provided in the home connectivity service network, the home agent address may be provided from the home AAA server to the access service network during the EAP authentication phase. In case the home agent is provided in the visited connectivity service network, the visited AAA server inserts the local home agent address in the AAA signalling to the access service network, owing to the provision of the home agent in the visited connectivity service network.
SUMMARY OF THE INVENTION
There may be a need to provide a method and a device for a local break out of data, in order to avoid a diversion of data traffic between the internet and the visited connectivity service network via the home connectivity service network.
The invention provides a device and a method for a local break out of data, a corresponding programme element and a computer readable medium according to the subject matter of the independent claims. Further embodiments are incorporated in the dependent claims.
It should be noted that the following described exemplary embodiments of the invention apply also for the method, the device, the programme element and the computer readable medium.
According to an exemplary embodiment of the invention, there is provided a home agent, which home agent being adapted to be placed in a visited connectivity service network, and which home agent being adapted to separate a first data traffic path and a second data traffic path, wherein the first data traffic path is routed between the visited connectivity service network and the internet, and the second data traffic path is routed between the visited connectivity service network and a home connectivity service network, in order to minimise a number of hops and delay times.
Thus, the home agent being placed in a visited connectivity service network provides the possibility of a local break out of data, so that it may be avoided to divert the internet traffic via the home connectivity service network, and to provide the break out to the internet in the home connectivity service network. In other words, by providing an inventive home agent in the visited connectivity service network, the internet traffic may be directly routed between the visited connectivity service network and the internet without the need to carry out a further hop via the home connectivity service network, which further hop would cause a further timely delay. Thus, those networks of the operators do not have to manage a data traffic to or from the internet, whose data traffic is not dedicated to the concerning networks. Further, the routing of internet protocol packets may be optimised, in particular when the access service network and the visited connectivity service network are located in a country being different from that country in which the home connectivity service network is located, i.e. in case of international roaming. Thus, the present invention provides for a device being capable of separating a data traffic for a local break out. The visited connectivity service network, in particular the home agent being provided in the visited connectivity service network decides which internet protocol packet is to be routed directly into the internet, and which internet protocol packet is to be routed into the home connectivity service network, either directly or via an own network connecting the connectivity service networks.
According to an exemplary embodiment of the invention, the first data traffic path and the second data traffic path are to be routed between the visited connectivity service network and an access service network.
This allows providing a data communication between, for example, a mobile station or a subscriber station accessing to the access service network and the internet, as well as a connection between the access service network and the home connectivity service network, wherein the respective data traffic is separated in the home agent provided in the visited connectivity service network.
According to an exemplary embodiment of the present invention, the traffic is routed to or from an internet protocol multimedia subsystem of the home connectivity service network.
According to an exemplary embodiment of the invention, the home agent has therein a configured internet protocol route to a connectivity service network, wherein the home agent is adapted to route data traffic based on the configured internet protocol route.
Thus, the home agent may, for example, separate the first and second data traffic path based on information stored in the home agent, for example, in a list or a look up table. The home agent may, for example, check the internet protocol address of a data packet to determine the destination of the respective internet protocol packet and may route packets having an address which is intended to be routed to the home connectivity service network to the home connectivity service network, i.e. without detention via the internet.
According to an exemplary embodiment of the invention, the internet protocol route is a static internet protocol route.
Thus, the allocation of the internet protocol packets and the respective routing is carried out in a pre-determined manner, without the need for a dynamic adoption or update.
According to an exemplary embodiment of the invention, the home agent is adapted to route data traffic, which is not routed to a connectivity service network, by default to the internet.
Thus, the volume of data representing the internet protocol route may be reduced, since only those addresses have to be stored which correspond to the respective connectivity service network, wherein in absence of an internet protocol packet address in, for example, the look up table, by default the internet protocol packet is routed to the internet. It should be noted that the data traffic to a connectivity service network also may be tunnelled, for example, via an L2TP or IPSec tunnel, depending on the contracts between the respective roaming partners.
According to an exemplary embodiment of the invention, the home agent is adapted to receive a routing policy from a home authentication, authorisation and accounting server, wherein the home agent is adapted to route data traffic based on the received routing policy.
Thus, during the mobile internet protocol authentication between the home agent and the home AAA server in the home connectivity service network, routing policies may be submitted from the home AAA server to the home agent, so that the home agent may use the received routing policies for the routing procedure, i.e. to route the internet protocol packets according to the received rules towards the correct corresponding destination. A mobile internet protocol authentication may be carried out during a mobile internet protocol registration and may serve to authenticate the subscriber and the mobile internet protocol specific key material to be submitted from the home AAA server to the home agent. It should be noted that “during” also means a short time before or after, or a totally or partially timely overlapping.
According to an exemplary embodiment of the invention, the home agent is adapted to associate a subscriber station internet protocol address and a foreign agent internet protocol address.
Thus, during mobile internet protocol registration, the internet protocol address of a subscriber station may be related to a foreign agent address in the home agent. The foreign agent may be implemented on the access service network gateway.
According to an exemplary embodiment of the invention, the routing policy comprises an internet protocol address or address range, wherein the address or address range being associated with a home connectivity service network, and wherein the home agent is adapted to route data traffic having a destination address of the home connectivity service network to or from the home connectivity service network.
Thus, the routing policy or routing policies provide for an internet protocol address or address range being managed by the home connectivity service network in order to serve as a base to route internet protocol packets having a destination address being included in the aforementioned address range from the home agent to the home connectivity service network.
According to an exemplary embodiment of the invention, the home agent is adapted to receive a key and to establish a secure data traffic route to or from the home connectivity service network.
Thus, the traffic to the home connectivity service network may, for example, be carried out in a tunnel, for example, an internet protocol security tunnel, in order to provide a secure connection between the visited connectivity service network and the home connectivity service network, for example, for the submission of sensitive data like, e.g., bank account access data, etc. It should be noted that it may be necessary to provide a key to the home agent in order to build up a secure connection to the home connectivity service network. The routing policy may, for example, be submitted as a separate attribute in the RADIUS or DIAMETER ‘access-accept’ message of the mobile internet protocol authentication to the home agent.
According to an exemplary embodiment of the invention, the home agent is adapted to dynamically adapt the routing policy during mobile internet protocol authentication.
According to an exemplary embodiment of the invention, the home agent is adapted to dynamically adapt the routing policy separately for each operator domain, for example, an internet or home connectivity service network domain.
Thus, it is possible to change dynamically the structure for authentication based on changed requirements of the home connectivity service network. If, for example, home connectivity service networks of different subscriber stations use overlapping internet protocol address ranges, it may be necessary to provide for routing policies in the home agent, which are individual for each operator of a domain, so that the requirements may be adapted to each of the several subscriber stations. Further, this may provide access control lists in the home agent in order to route particular data traffic of a subscriber station from a particular domain to a certain gateway or through a pre-configured tunnel. Since the number of domains, as well as the number of internet protocol address ranges is limited, the home agent does not have to store large routing tables or access control lists.
According to an exemplary embodiment of the invention, there is provided a visited connectivity service network having implemented therein an inventive home agent, as previously described.
According to an exemplary embodiment of the invention, there is provided a method for separating data traffic in a home agent comprising separating in a home agent, which home agent being located in a visited connectivity service network, a first data traffic path and a second data traffic path, wherein the first data traffic path is routed between the visited connectivity service network and the internet, and the second data traffic path is routed between the visited connectivity service network and a home connectivity service network, in order to minimise the number of hops and delay times.
According to an exemplary embodiment of the invention the method may further comprise associating a subscriber station (SS) internet protocol address and a foreign agent (FA) internet protocol address.
According to an exemplary embodiment of the invention in relation to the method it may be foreseen that the routing policy comprises an internet protocol address or address range, the address or address range being associated to a home connectivity service network (H-CSN), and the method further comprising routing data traffic having a destination address of the home connectivity service network (H-CSN) to or from the home connectivity service network (H-CSN).
According to an exemplary embodiment of the invention the method may further comprise receiving a key and establishing a secure data traffic route path to or from the home connectivity service network (H-CSN).
According to an exemplary embodiment of the invention the method may further comprise dynamically adapting the routing policy during a mobile internet protocol (MIP) authentication.
According to an exemplary embodiment of the invention in relation to the method it may be foreseen that the routing policy is provided separately for each subscriber station and/or operator domain.
It should be noted that, according to several exemplary embodiments of the invention, the method may have implemented the functions and features which have been described with respect to the home agent device described above. The description of the home agent therefore applies correspondingly to the method, as well as the programme element and the computer readable medium.
According to an exemplary embodiment of the invention, there is provided a programme element, which, when being executed by a processor, is adapted to carry out the inventive method.
According to an exemplary embodiment of the invention, there is provided a computer readable medium having stored the inventive programme element.
It should be noted that the above features may also be combined. The combination of the above features may also lead to synergetic effects, even if not explicitly described in detail.
These and other aspects of the present invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention will be described in the following with reference to the following drawings.
FIG. 1 illustrates a WiMAX roaming scenario, where a home agent is provided in a home connectivity service network.
FIG. 2 illustrates a WiMAX roaming scenario, where the home agent is provided in a visited connectivity service network.
FIG. 3 illustrates a WiMAX roaming scenario with a local break out, where a home agent is provided in a visited connectivity service network.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIG. 1 illustrates a WiMAX roaming scenario, in which the home agent is located in the home connectivity service network. A mobile station (MS) may access an access service network (ASN) via a base station (BS) and an access service network-gateway (ASN-GW). The ASN gateway carries out an extended authentication protocol authentication to a visited authentication, authorising and accounting server (V-AAA) in a visited connectivity service network (V-CSN), wherein the visited AAA server further carries out an extensible authentication protocol (EAP) authentication to a home AAA server in a home connectivity service network. A home agent being provided in a home connectivity service network receives during mobile internet protocol authentication a key to build up a data transmission connection between the access service network and the home connectivity service network, in particular the home agent. The data transport path for carrying out a routing of a data transport will be established from the home agent in the home connectivity service network to the mobile station (MS) via a router in the visited connectivity service network, the access service network gateway (ASN-GW) and the base station (BS). The data path may be provided as a mobile internet protocol (MIP) tunnel.
The home agent (HA) in the home connectivity service network (H-CSN) will provide data to the home connectivity service network via a data transport path to an internet protocol multimedia subsystem (IMS). The home agent further establishes a data transport path to the internet, wherein the internet is a separate network from the home connectivity service network. This roaming scenario being illustrated in FIG. 1 is called R3 roaming, in which the home agent in the home connectivity service network routes internet protocol packets into the internet or into the home connectivity service network, in particular the IMS.
FIG. 2 illustrates a WiMAX roaming scenario, wherein the home agent is provided in the visited connectivity service network. The configuration of the access service network is the same as already described with respect to FIG. 1 . Also the EAP authentication via a visited AAA server in the visited connectivity service network to the home AAA server and the home connectivity service network is the same as already described with respect to FIG. 1 . FIG. 2 illustrates an architecture, in which the home agent is provided in the visited connectivity service network (V-CSN), and the MIP authentication is carried out between the home AAA server in the home connectivity service network and the home agent (HA) in the visited connectivity service network. Based thereon, the home agent establishes a data transport path between the mobile station (MS) and the access service network (ASN) via the base station (BS) and the ASN-gateway (ASN-GW) via the home agent to the internet. It should be noted that the architecture described with respect to FIG. 2 provides a home agent, which routes all data packets into the internet, wherein the internet protocol packets being intended to be routed to the home connectivity service network are first routed to the internet and then routed to the home connectivity service network, in particular the IMS in the home connectivity service network. This roaming scenario is a so called R5 roaming.
FIG. 3 illustrates a WiMAX roaming scenario with a local break out, where the home agent (HA) is provided in the visited connectivity service network (V-CSN). The configuration of the access service network (ASN) is the same as already described with respect to FIG. 1 .
Also the EAP authentication from the access service network to the home AAA server of the home connectivity service network (H-CSN) via the visited AAA server of the visited connectivity service network is the same as already described with respect to FIG. 1 . The home agent (HA) in the visited connectivity service network provides a data transport path between the visited connectivity service network (V-CSN) and the access service network (ASN), wherein this data transport path may be an MIP tunnel. The home agent (HA) in the visited connectivity service network receives from the home AAA server of the home connectivity service network during, for example, the MIP authentication, a routing policy or routing policies. It should be noted that the reception of the routing policy is not mandatory timely during the MIP authentication, and that the term ‘during’ should be understood as coupled with the MIP authentication. This means that the reception of the routing policy does not have to be fully covered by the time required for the MIP authentication, and may also be carried out, at least partially, before or after the MIP authentication.
The home agent is adapted to carry out a separation of the data traffic path to the home connectivity service network and the internet, namely based on information stored in the home agent. This information may be, for example, static, however, may also be dynamically adapted by successively receiving routing policies from the home AAA server in the home connectivity service network. Based on this information, which information may be the routing policies, the data traffic paths may be separated so that the home agent may provide internet protocol packets having an address corresponding to an address or address range of the home connectivity service network to the home connectivity service network, in particular to the IMS in the presently illustrated architecture. The data traffic path may be carried out on an L2TP or IPSec tunnel between the home agent and the H-CSN.
If, for example, the home connectivity service network includes the address range 120.1.1.0 to 120.1.2.255, the home agent will route internet protocol packets having an address being included in this address range as a destination address to the home connectivity service network, for example, via an L2TP or IPSec tunnel or via a further intermediate network. The home agent thus may have stored the address range of the home connectivity service network of 120.1.1.0 to 120.1.2.255. However, the home agent may also have stored a further address range, for example, 162.1.0.0 to 162.1.0.255, which corresponds to an address range of a further connectivity service network. Thus, if receiving an internet protocol packet having an address included in the address range of the home connectivity service network, the home agent will route the packet to the home connectivity service network. If receiving an internet protocol packet having an address being included in the address range of a further connectivity service network, the home agent will route the internet protocol packet to the other connectivity service network, wherein, for example, internet protocol packets with all remaining addresses will be generally routed to the internet. It should be noted that the home agent thus may have included a plurality of address ranges of different connectivity service networks. These address ranges may also overlap so that if an IP packet having an address being included in the overlapping range, this IP packet will be routed to the connectivity service network the mobile or subscriber station is subscribed to.
For the method, which may be carried out by the home agent, during an MIP authentication between the home agent and the home AAA server, a routing policy or routing policies are submitted from the home AAA server to the home agent, so that the home agent may use the routing policy for the further routing process. The routing process may be carried out based on the routing policy, in order to forward the internet protocol packets to the intended destination. The MIP authentication may be carried out during the MIP registration, and may serve to authenticate the subscriber station and to provide the subscriber station with MIP specific key material, which key material is submitted from the home AAA server to the home agent. It should be noted that the MIP authentication may be also carried out during a time before or after registering or overlapping with the time for registration.
By the MIP registration, in the home agent the IP address of the subscriber station will be related to the foreign agent address. The foreign agent (FA) may be implemented on the access service network gateway (ASN-GW).
In a very simple case, the routing policy includes the IP address ranges being managed by the home connectivity service network (H-CSN). IP packets having a destination address being included in the above mentioned address range, are therefore to be routed from the home agent to the home connectivity service network. If an internet protocol packet address is included in the address range being managed by the home connectivity service network, the respective internet protocol packet is routed to a gateway having the respective address in the home connectivity service network. The data traffic may also be carried out in a tunnel for sake of security. In this case, further keys have to be submitted to the home agent in order to establish a safe connection to the home connectivity service network. Since the routing policy may be provided by the respective home AAA server, the volume of the information to be submitted is limited and the values may be changed dynamically at an MIP authentication by the home connectivity service network. If the home connectivity service networks of different subscriber stations use overlapping IP address ranges, the routing policies in the home agent have to be provided in the home agent for each mobile or subscriber station and each operator domain, wherein such a domain may be the internet or a connectivity service network. Thus, in the home agent access control lists (ACL) may be created and built up, which ACL determine that the data traffic of a subscriber station from a particular domain has to be routed to a particular gateway or by a pre-configured tunnel.
If providing routing policies dynamically from the home connectivity service network to the visited connectivity service network, in particular to the home agent in the visited connectivity service network, a static establishment of a plurality of different rules in the home agent may be avoided. If changing the address ranges in the home connectivity service network, it may further be avoided to instruct all roaming partners (visited connectivity service networks) in order to adapt the configuration. This may be carried out automatically during the next MIP authentication of a subscriber station.
Overlapping address ranges in the home connectivity service network or different subscriber stations may be supported by the use of tunnels (VPN technologies).
It should be noted that the term ‘comprising’ does not exclude other elements or steps and the ‘a’ or ‘an’ does exclude a plurality. Also elements described in association with the different embodiments may be combined.
It should be noted that the reference signs in the claims shall not be construed as limiting the scope of the claims. | A home agent is configured to be placed in a visited connectivity service network and configured to provide a possibility of a local break out of data. The home agent is configured to separate a first data traffic path and a second data traffic path. The first data traffic path is directly routed between the visited connectivity service network and the internet, and the second data traffic path is routed between the visited connectivity service network and a home connectivity service network, in order to minimize a number of hops and delay times. The home agent is configured to receive a routing policy from a home authentication, authorization and accounting server. The home agent is configured to route data traffic based on the received routing policy. | 7 |
This application claims priority from U.S. provisional patent application Ser. No. 60/055,493, filed Aug. 14, 1997.
FIELD OF THE INVENTION
This invention is directed to a seal and a process for minimizing interzonal fluid migration in boreholes.
BACKGROUND OF THE INVENTION
When petroleum well bores are drilled to the desired depth for production, the well operator determines whether the well bore should be placed into production or abandoned. A bore hole cuts through the various rock layers in the formation through which it is drilled and provides a route between the numerous porous zones of the formation. The bore hole allows fluids to migrate either upwardly or downwardly in between zones. Such interzonal migration must be controlled.
When it is determined that the well bore should be placed into production, a casing is run into the well. The casing is a length of tubing usually formed of steel. To prevent migration of fluids through the annulus between the casing and the well bore wall, a cement slurry is often pumped into the annulus during well completion. The cement is placed in sufficient volume to displace the drilling fluid in the annulus and is intended to prevent interzonal migration of fluid outside of the casing. However, fluid migration outside of the casing sometimes occurs through voids formed during set up of the cement or due to cement decomposition. Because the cement, when set, is solid, any voids formed in the cement during set up are permanent.
In some drilled bore holes, it is determined that the hole is not suitable for production. Such a bore hole is abandoned without running casing. Cement is also used in open boreholes to plug and abandon the well. Voids may also form during the set up of the cement in an abandonment plug.
Problematic interzonal migration occurs through voids in the cement seals used for completion and abandonment of boreholes.
SUMMARY OF THE INVENTION
A seal and a process have been invented for minimizing interzonal migration of fluids in a borehole.
In accordance with a broad aspect of the present invention, there is provided a process for sealing a borehole having a bottom, the process comprising placing an amount of a bituminous material into the borehole to extend up from the bottom of the borehole, the bituminous material being selected to remain viscous over time in borehole conditions retaining its ability to flow.
In accordance with another broad aspect of the present invention, there is provided a process for sealing a well, the well having a borehole defined by a bottom and side walls and being lined with a casing, the process comprising placing an amount of a viscous material into the casing, to fill a length of the borehole above the bottom of the borehole, the viscous material being selected to remain viscous over time in borehole conditions, to retain its ability to flow.
In accordance with a further broad aspect of the present invention, there is provided a casing annulus seal comprising an amount of viscous material disposed in the casing annulus, the material being selected to remain viscous over time in borehole conditions, the amount of viscous material in the annulus forming a vertical column sufficient to effect a seal against the pressure of fluids attempting to migrate into the annulus, and a means for retaining the viscous material in the annulus.
In accordance with a further broad aspect of the present invention, there is provided a casing annulus seal comprising: an amount of bituminous material disposed in the casing annulus and a means for retaining the bituminous material in the annulus.
In accordance with a further broad aspect of the present invention, there is provided a well comprising a borehole having a wall and lined along a portion of its length with a casing, an amount of viscous material disposed in the casing annulus, the material being selected to remain viscous over time in borehole conditions, and a means for retaining the viscous material in the annulus.
In accordance with another broad aspect of the present invention, there is provided a process for completing a cased well, the well having a casing extending therein and a casing annulus surrounding the casing, the process comprising: retaining an amount of a viscous material in the casing annulus, the viscous material being selected to remain viscous over time in borehole conditions, to retain its ability to flow.
In accordance with a further broad aspect of the present invention, there is provided a process for completing a cased well, the well having a casing extending therein and a casing annulus surrounding the casing, the process comprising:
retaining an amount of a bituminous material in the casing annulus.
DESCRIPTION OF THE INVENTION
The seal and process of the present invention are useful in cased wells to reduce interzonal migration of fluids between the borehole wall and the casing in the area termed herein as the casing annulus. The seal and process of the present invention are also useful in cased or uncased wells during well or borehole abandonment.
The seal includes a viscous material which is placed where a seal against the migration of fluids is desired for example in the casing annulus or across the borehole. A viscous material which is useful in the present invention is a material which will remain viscous over time in borehole conditions thereby retaining its ability to flow. The viscous material must be of sufficient viscosity to prevent the leakage and loss of the material into fissures and porous materials (i.e. sandstone). In one embodiment, the viscous material contains solid material and preferably fine grain solid matter such as for example, clay fines and/or sand. In a preferred embodiment, the solid material is present in a gradation of sizes to enhance the plugging and sealing characteristics of the viscous material. The viscous material must also have a density greater than water so that it will not be displaced by water which may be present in the borehole. It has been found that a bituminous material, such as asphalt, is useful for use as the sealing material.
The seal includes a retaining means to maintain the placement of the viscous material in the borehole. Suitable retaining means depend on the desired position of the seal. Where the seal is in the annulus of a cased well, the retaining means can be, for example, a mechanical means such as an external packer, or other means such as a cement platform or a combination thereof. Where the seal is in an open bore hole, the retaining means can be the bottom of the bore hole.
Since the retaining means acts to prevent the seal from moving out of its sealing position, the permanency of the seal can be controlled by the selection of the retaining means. For example, a temporary mechanical means can be used to temporarily retain the viscous material of the plug, while viscous material placed on the bottom of the borehole will be retained indefinitely, thereby forming a substantially permanent seal. The materials used to form the retaining means are preferably selected with consideration as to the borehole conditions. For example, where a formation produces hydrogen sulphide, the retaining means is preferably formed of sulphate resistant materials, such as sulphate resistant cement.
The sealing properties are provided by the hydrostatic pressure of the viscous material as determined, for example, by the height and density of the column of viscous material used. The hydrostatic pressure forces the material into fissures of the formation and into close contact with the structures in the borehole and acts against the pressure of fluids attempting to migrate from the productive zone. The hydrostatic pressure can be increased by increasing the height of the column of viscous material. In one embodiment, the viscous material extends from the retaining means to the surface opening of the borehole. In instances where bituminous material is only placed in the lower portion of the borehole, additional hydrostatic pressure can be provided by the presence, above the viscous material, of a liquid having a lower density than the viscous material. In one embodiment, the viscous material is a bituminous material and the liquid is water.
Alternately or in addition, the hydrostatic pressure of the viscous material can be increased by the addition of weighting materials thereto. For example, where the viscous material is asphalt, weighting materials such as crushed and/or ground barite and/or calcium carbonate can be added thereto to increase the density of the viscous column.
The seal is preferably placed in the portion of the well which passes through a layer of impermeable rock to prevent the passage of fluids between the productive zone and upper layers. The process for placement of the seal can include a preliminary examination of data related to the borehole to locate the position of the impermeable rock layer. Further, in the preferred embodiment the borehole and well data is examined to determine additional information, for example: the pressure of the fluids in the productive zone (this is useful information in the determination of the hydrostatic pressure which is required to effect a seal); and the most likely source of fluids that may migrate up the borehole (useful in determining if the fluids are hazardous or corrosive).
The viscous material can be placed in the well by any suitable means. For example, where the viscous material is bituminous material, it can be placed in the well by heating it to reduce its viscosity temporarily. This enables it to be pumped down the well. It can, alternately, be dumped at ambient surface temperature down the well. In another method, the bituminous material is introduced to the well as an emulsion. Once introduced the emulsion can be left to break on its own or can be broken by use of suitable breakers such as, for example, salt brine, acids, caustic soda or by passing an electric current therethrough. In yet another method, the material is cooled to a solid or near-solid state and processed to form pellets. The pellets are dumped down the well. At well temperatures, the pellets liquefy to a viscous state and flow to fill the space in the well into which they are introduced.
The seal is used in any position in a well where it is desired to seal off a passage of fluids. The fluids can be oil, gas, water or any other fluid which is leaking through the well bore. In one embodiment, the seal can be in the annulus of a cased well to complete the well and prevent migration of fluids outside of the casing in producing wells. In another embodiment, the seal is used as a plug during well abandonment to block migration of fluids along the well.
When the seal is used as a well bore abandonment plug, the plug can be used in cased wells or uncased wells. The plug can be placed to extend up from the bottom of the well. When it is placed in this way, the bottom of the well will retain the plug in position. Alternately, the plug can be positioned to extend upward from any position in the well by use of another retaining means such as a cement platform which is already present in the well or which is placed in the well to assist in plug placement.
To form the plug, the viscous material is introduced to the well to extend up either from the bottom of the well or from some other retaining means, such as a cement platform or a bridge plug. When the retaining means must be placed in the borehole, it is placed below the selected position of the viscous material which forms the sealing portion of the plug.
The viscous material must be placed in the borehole such that it can flow to seal the passage of fluids about the plug. Thus, in a cased well, preferably the well is prepared for placement of the viscous material by opening a port in the casing to gain access to the casing annulus. After opening a port in the casing, the viscous material can flow unimpeded into any voids behind the casing. The port should be formed at a position adjacent an impermeable rock layer. Preferably, the port are formed along a length of the casing, for example a length of at least 2 metres, to allow some margin of error in the positioning of the port at an impermeable rock layer. The port can be formed by perforating the casing. In a preferred embodiment, substantially all of a cylindrical section of the casing is removed such that the viscous material can flow to fill any voids behind the casing. In one embodiment, a cylindrical portion of the casing, the solid material in the annulus behind this portion of the casing and a portion of the exposed borehole wall are removed, such as by milling or grinding, prior to placement of the viscous material. By such an operation, a section is formed in the borehole which is substantially free of any material which may provide a conduit for the passage of fluids about the plug. A similar operation is also useful in the abandonment of an uncased borehole. In such a borehole, contamination on the surface of the borehole walls can be removed, thereby enhancing the integrity of the seal provided by the plug. Preferably, the removal of a portion of the borehole wall is carried out in a manner which substantially avoids fracturing of the rock.
Where the borehole has been prepared for placement of the viscous material by removing a portion of the casing and a retaining means is used to maintain the placement of the plug above the bottom of the borehole, the retaining means should be positioned to block any large voids through which the viscous material may pass down the borehole, past the retaining means.
Once the borehole is prepared, the viscous material is applied on top of the retaining means. An amount of viscous material is added to fill any voids in the borehole and to effect a seal against the pressure of fluids moving up the well from the productive zone. Further, an amount of viscous material is preferably used which can flow to fill voids which may arise over time. If necessary, weighting materials are added to the material to increase its density.
If desired, the liquid is then added above the viscous material. Liquid such as water may also be present in the borehole. This liquid will be displaced up the borehole by placement of the viscous material and, therefore, will be present above the viscous material and can remain there.
The present plug can be used in the abandonment of a well which passes through a plurality of productive zones. The plug can be placed such that the viscous material is able to extend through a plurality of productive zones and impermeable layers. Where the well is cased, a cylindrical section of the casing or casing and surrounding cement and borehole wall can be removed at each impermeable layer between the productive zones or the casing can be perforated at each impermeable layer.
As noted hereinbefore, the seal can also be used in the casing annulus to complete a cased well. The casing annulus seal can be used in a cased well having no cement or in a cased well having cement behind at least portions of its length. The casing annulus seal prevents the migration of fluids outside of the casing, but fluids can still pass through the casing tube.
In a cased well having no solid annular material, the seal can be placed at any location in the casing annulus. It can extend for substantially the entire length of the casing or only along a portion thereof. The viscous material is retained in the annulus of the casing in any suitable way, such as by an external packer or by introduction of an amount of cement which is allowed to set below the viscous layer. The viscous material can be introduced into the casing annulus using any suitable means, for example, a one-way check valve mounted adjacent the lower opening of the casing and a wiper plug. The wiper plug is forced down the casing after introduction of the viscous material to force the material through the check valve and into the casing annulus. An amount of un-set cement can be introduced after the viscous material such that it is positioned below the viscous material in the annulus. When set the cement will act to retain the viscous material in sealing position in the annulus.
Where the cased well contains cement or an anchor in the annulus along a portion thereof, the viscous material can be introduced into the casing annulus above and/or, if possible, below the cement. Where the bottom of the casing is open and not blocked by cement, standard completion procedures can be used, as described above, to introduce the viscous material to the casing annulus.
Where the viscous material is to be introduced above the existing cement or anchor, any suitable method can be used to position the viscous material. As an example, perforations can be made in the casing above the cement or anchor through which the material can be introduced to the casing annulus. The perforations can be patched, according to known procedures, to permit the well to be returned to production. In another method, the viscous material is poured into the annulus from above. In yet another method, the viscous material is introduced through a stage collar.
The viscous material is placed in the casing annulus to extend past at least one impermeable layer to prevent interzonal migration of fluids outside the casing. The viscous material can have added thereto weighting materials to increase its density, thereby, to increase the hydrostatic pressure of the material in the annulus. Alternately or in addition, water can be added above the viscous material to increase the hydrostatic pressure.
Once the well is completed by introduction of the viscous material into the casing annulus, the well can be placed into or returned to production. The seal prevents migration of fluids outside the casing. Where it is desired to open a new producing zone along the well, an amount of cement can be introduced into the casing annulus at the desired location of the productive zone and allowed to set at that location. Perforations are then made through the cement layer to gain access to the producing zone.
To abandon a well which has viscous material disposed in the annulus, the casing can be filled with further amounts of viscous material with or without initially perforating the casing to allow communication between the inside of the casing and the annulus.
BRIEF DESCRIPTION OF THE DRAWINGS
A further, detailed, description of the invention, briefly described above, will follow by reference to the following drawings of specific embodiments of the invention. These drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. In the drawings:
FIG. 1 shows a schematic representation of a section along an open borehole;
FIG. 2 shows a schematic representation of a section along a borehole, the borehole having been cased with a casing tube;
FIG. 3 shows a schematic representation of a section along a borehole, the borehole having been cased and completed, according to the prior art, by placement of cement in the annulus about the casing:
FIG. 4 shows a schematic representation of a section along a plug according to the present invention, the plug being positioned within a borehole;
FIG. 5 shows a schematic representation of a section along a well, the well having had a section of casing, the cement in the casing annulus removed and a portion of the borehole wall removed;
FIG. 6 shows a schematic representation of a section along another plug according to the present invention, the plug being positioned within a borehole;
FIG. 7 shows a schematic representation of a section along a cased borehole, the borehole having a seal placed in the casing annulus according to a process of the present invention;
FIG. 8 shows a schematic representation of a section along another completed well according to the present invention;
FIG. 9 shows another schematic representation of a section along another completed well according to the present invention; and
FIG. 10 shows another schematic representation of a section along another completed well according to the present invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
Referring to FIG. 1, a sectional schematic view of an open borehole is shown. The borehole, indicated at 12, is defined by walls 13a and bottom 13b and passes through a formation including an upper permeable layer 14 and an impermeable rock layer 16 into a permeable layer, termed the productive zone 18.
Referring to FIG. 2, a borehole 12 having a casing tube 20 therein is shown. Casing tube 20 is commonly formed of steel. The casing extends substantially from the ground surface 11 to bottom 13b of borehole. An annulus 22 is formed between casing 12 and borehole walls 13a.
FIG. 3 shows, a sectional schematic view of a conventional cased and sheathed well is showing having a borehole, indicated at 12 and defined by walls 13a and bottom 13b, which passes through a formation including an upper permeable layer 14 and an impermeable rock layer 16 into a production zone 18. Within borehole 12 is a casing 20 formed of steel. Cement 22a is positioned in the annulus about casing 20. Prior to abandonment, the well is substantially uniform having the arrangement of casing and sheath along most of the borehole, as shown. Casing 20 is embedded in a cement anchor 23 at its lower end.
A well abandonment plug according to the present invention can be used in uncased or cased wells.
Referring to FIG. 4, a sectional schematic view of a plug 28 according to the present invention is shown. Plug 28 is placed in borehole 12 of a well to prevent the passage of gas and liquid into and through the well at the position of the plug. Plug 28 includes bitumen 34 which may contain particulate matter and, preferably, fine grain particulate matter. The bitumen is positioned to extend up the borehole from its bottom 13b past the impermeable rock layer 16.
The hydrostatic force of the bitumen causes the bitumen to be brought into close contact with the walls 13a of borehole 12 and forced into cracks in the borehole wall. Because the bitumen is viscous at borehole conditions, the bitumen can flow to seal any cracks which may develop over time in the borehole.
To place plug 28, the bitumen is introduced to the borehole by any suitable means. For example, the bitumen can be heated, to reduce its viscosity temporarily, enabling it to be pumped down the well. In another embodiment, the mixture is cooled to a solid or near-solid state and processed to form solid pellets. The pellets are dumped down the well bore. Once in place, the heat within the well causes the bitumen pellets to liquefy to the viscous state to effect well bore plugging. In another embodiment, the pellets are maintained separate during the placement process by admixing the pellets with a liquid, such as water. The water is introduced with the pellets to the well bore. In yet another embodiment, the bitumen is introduced as an emulsion in water.
A column of bitumen is introduced to the well to yield sufficient hydrostatic pressure to prevent the passage of fluids from the productive zone into the wellbore. This can be done by simply adding bitumen until the passage of fluids is stopped. Alternately, the fluid pressure in the productive zone can be determined and this pressure can be used to determine the required height of bitumen which is required to effect a seal. From a knowledge of the fluid pressure of the production zone and the density of the bitumen, the required height of the bitumen column can be calculated. This height can then be translated into the required volume from a knowledge of the wellbore dimensions and volume factor. More specifically, the required height of the bitumen column can be obtained, as follows:
H=P·(1+SF)/(S.G.·9.81)
Where H=requited hight of bitumen column (m)
P=fluid pressure of the production zone (kPa)
S.G.=specific gravity of bitumen
9.81=constant equal to the hydrostatic gradient of water (kPa/m)
SF=safety factor
If one assumes that P=1,000 kPa, S.G.=1.01 and SF=0.25, then ##EQU1## To translate this height into volume of bitumen, a knowledge of the volume factor of the wellbore is required. If one assumes the borehole is 158.75 mm in diameter with no casing in the hole, the volume factor would be 0.0198 m 3 /m. The required volume of bitumen, V, would then become: ##EQU2## In summary, the resultant hydrostatic pressure of the plug can be raised by increasing the height of the bitumen column or by increasing the specific gravity of the bitumen by adding weighting materials to it.
Referring to FIG. 6, a sectional schematic view of a another plug 28a is shown. Plug 28a is placed in borehole 12 of a well to prevent the passage of gas and into the well borehole. Plug 28a includes asphalt 34a positioned on top of cement layer 23 which was placed in the well during the well completion. Cement layer 23 acts to retain asphalt 34a in its position in the well. The total hydrostatic force of the mixture causes it to be forced into close contact and into cracks in the borehole wall, the casing and any cement in the borehole by the hydrostatic force, and will continue to do so as the casing disintegrates.
The preferred process for placement of plug 28a can be better understood by referring to FIGS. 3, 5, and 6. After examination of well information, a position is located substantially adjacent impermeable layer 16. As best seen in FIG. 5, at this position, a section of the well is milled out to remove a cylindrical portion of the casing, the cement behind the casing and a layer of the borehole wall to form a section, indicated at 40. At least a portion of section 40 is within impermeable rock layer 16.
Mixture 34a is placed into the well in a sufficient volume such that a column is formed which extends from layer 23 up into section 40 and produces a sufficient hydrostatic pressure to prevent fluids from passing the plug. Mixture can be introduced to the well by first heating it, to reduce its viscosity temporarily, enabling it to be pumped down the well and onto cement layer 23. The mixture can be placed down the well by other methods. In one embodiment, the mixture is cooled to a solid or near-solid state and processed to form solid pellets. The pellets are placed on top of layer 23 by dumping them down the well bore. Once in place, the heat within the well causes the asphalt pellets to liquefy to the viscous state to effect well bore plugging. In another embodiment, the pellets are maintained separate during the placement process by admixing the pellets with a liquid, such as water. The water is introduced with the pellets to the well bore. In yet another embodiment, the asphalt is introduced as an emulsion.
FIG. 7 shows a sectional schematic view of a cased well having a casing annulus seal 70 according to the present invention. Casing annulus seal 70 is used in well completion to prevent the migration of fluids outside of the casing between a productive zone 18 and another layer, for example a permeable layer 14, while permitting the passage of fluids within the casing. Seal 70 is formed of asphalt 34a which is retained in position in the annulus 22 of casing 20 by an external casing packer 72. Packer 72 has at least one one-way flapper valve 73 which permits liquids to flow upwardly through the valve but restricts flow in the reverse direction. At least a portion of the asphalt 34a is adjacent the impermeable rock layer 16. Preferably, the asphalt fills the full length of the casing annulus.
The casing annulus seal is positioned by pumping the asphalt down the inside of the casing and up around the bottom of the casing tube 20 past the packer into the annulus 22. Once in place in the annulus, the asphalt is prevented from draining back into the casing tube 20 by the packer 72 in combination with the flapper valve 73.
If necessary, depending on the pressure of fluids in the well, weighting materials are added to the asphalt to be used in the seal. The asphalt can alternately be introduced in the form of an emulsion.
There are many other methods for placing a casing annulus seal according to the present invention in position. FIGS. 5 to 7 illustrate some exemplary methods.
Referring to FIG. 8, the seal is positioned in a borehole 12 having a casing tube 20 anchored by a cement grout anchor 79. A stage collar 80 is provided in casing 20 above anchor 79. Stage collar 80 has a sliding sleeve 81 that can be moved to a first position to open access ports 82 to annulus 22 and to a second position to seal access ports 82. The casing annulus seal is formed of asphalt 34a which is introduced to annulus 22 through ports 82, when the sleeve is in the first position. When a desired amount of asphalt is introduced to the annulus, the sliding sleeve 81 is moved to the second position to seal the access ports. The asphalt is retained in the annulus by the cement anchor and the sealing sleeve.
FIG. 9 shows another casing annulus seal in which the bituminous material 34 of the seal is introduced into the annulus by first forming perforations 84 through casing 20 above cement anchor 79 and forcing the material 34 therethrough. After the annulus 22, is filled to a selected level with the asphalt, a metal patch 85 is then secured over perforations 84 to prevent the material from draining back into the casing.
FIG. 10 shows another casing annulus seal which is formed by first pumping an amount of bituminous material 34 down the casing tube 20, followed by an amount of un-set cement. The bituminous material and cement are forced through a check valve 86 into the annulus by a wiper plug 87. The cement will eventually set to form an anchor to retain the bituminous material in position in the annulus.
It will be apparent that many other changes may be made to the illustrative embodiments, while falling within the scope of the invention and it is intended that all such changes be covered by the claims appended hereto. | A process and a material for use in sealing casing lining in a borehole is taught. The process includes the placement of a bitumen sealant material in a position between the casing tube and the wall of the borehole to be maintained in this annulus by means of a retaining devise such as an external casing packer or with the placement of a retainer made of cement grout and situated at the lower end of the casing tube. The bitumen sealant material prevents the passage of fluids vertically through the borehole. The sealant material remains viscous over time and can flow to fill voids which may occur in the rock formations adjacent to the borehole, or in the steel casing of the casing tube. To improve the sealing capabilities of the bitumen material a measured amount of fine grain weight material can be added to the bitumen to increase the density of the sealant material and thereby increase the hydrostatic pressure that the column of bitumen sealant will exert on the bottom and the walls of the borehole. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for continuously producing a precipitate by reacting together at least two reactants. More specifically, the invention relates to a vortex apparatus, intended more particularly for producing precipitates which are particularly adhesive during their formation.
A precipitation apparatus is already known, which comprises a fixed cylindrical vessel having a vertical axis into which the reagents are continuously introduced at the top of the said vessel and in the vicinity of its axis. A stirrer formed by a magnetized bar is positioned on the bottom of the vessel. The rotation of this bar is controlled by a rotary magnetic field generator positioned below the bottom of the vessel. The rotation of the stirrer makes it possible to produce a vortex, which has the effect of stirring the mixture and removing the freshly formed precipitates from the walls. Thus, the precipitates, which are denser than the solution, form in the vicinity of the vessel axis and tend to become localized there. Thus, the precipitates age in the vicinity of the vessel axis before lightly touching the vessel walls and are discharged with the solution via an overflow formed in the upper part of the vessel. Heating means may have to be provided outside the vessel if made necessary by the chemical reaction.
Thus, in this known apparatus, the vortex has the effect of moving the freshly formed precipitates away from the supports, which prevents incrustation of the apparatus when the precipitates are particularly adhesive. However, this apparatus has a certain number of disadvantages. Thus, when the envisaged chemical reaction involves radioactive products, the limits imposed by the safety conditions significantly restrict the capacity of such an apparatus. The increase in the capacity consequently necessitates the arrangement in parallel of a plurality of such apparatus, which has the effect of complicating the division of the feeds and the collection from the overflows. Moreover, the friction of the stirrer on the bottom of the vessel leads to a relatively short service life of the apparatus, which can only be improved by equipping the stirrer and the bottom of the vessel with special coatings based on tetrafluoroethylene and stainless steel. The effect of such equipment is to significantly increase the cost of the precipitator and leads to a limited period of use. In addition, the direct discharge of the precipitate through an overflow formed in the fixed vessel is accompanied by a simultaneous discharge of the solution, which is explained by the fact that the precipitates are denser than the solution.
In addition, precipitation apparatus are known, which comprise two, coaxial, fixed, cylindrical channels having vertical axes into which the reagents are introduced via the upper part of the central channel. The mixture is stirred by means of a plurality of stirrers regularly distributed around a rotary shaft positioned in the central channel. The rotary shaft carries a bladed turbine beneath the lower orifice of the central tube. This turbine ensures the raising of the precipitate and the solution in the lateral channel up to an overflow provided in the upper part of the lateral channel. This apparatus functions discontinuously, because the velocity of the liquids in the lateral outlet channel would be too low to raise the precipitate up to the overflow. This would lead to the choking up of the apparatus. Moreover, the precipitates tend to form dense beds between the stirrers.
Finally, precipitation apparatus are known, which comprise two fixed, coaxial, cylindrical channels in which the mixture is stirred by means of a scraper, which rotates in the central channel and undergoes vertical shocks to ensure its cleaning. At the bottom of the central channel, the reagents are stirred by a turbine, which localizes a dense precipitate bed. The solution rises in the lateral channel and is then discharged through an overflow. During its rise, the solution is purified of the precipitate, which settles and passes through the dense bed to be received at the base of the apparatus. Although this apparatus functions continuously, it does not permit a very high flow rate, because the increase in the flow rate helps to bring about the incrustation of the scraper. Moreover, in this solution, the precipitate must be raised at the outlet of the apparatus and it should be noted that the increase in the flow rate is also unfavourable to the raising of the precipitate.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is to provide a vortex apparatus, which is particularly intended for the continuous production of a relatively adhesive precipitate, although it is not limited thereto. This precipitator does not have the disadvantages of the prior art precipitators. Thus, the main object of the invention is the provision of a large capacity precipitator having a particularly long service life, whilst ensuring both the raising and the separation of the precipitates, although their density is higher than that of the solution, by carrying out a significant recycling of the solution and without affecting the precipitation time. The invention also relates to the provision of an apparatus in which the reagents present can be heated or cooled, if necessary, by means located within the very apparatus, which was not possible in the case of the prior art precipitators.
Thus, the present invention specifically relates to a vortex apparatus for the continuous production of a precipitate by reacting together at least two reactants, wherein it comprises a rotary bowl, having a vertical axis a fixed cylinder arranged coaxially within the bowl and being positioned with its bottom spaced from the bottom surface of the rotary bowl thereby defining an annular raising chamber and providing a fluid flow connection between the raising chamber and a reaction chamber defined within the cylinder, reactant inlet pipes issuing into the upper part of the reaction chamber in the vicinity of the axis of the bowl, at least one weir fixed to the rotary bowl at the upper end of the raising chamber and a turbine fixed to the rotary bowl in the lower part of the reaction chamber, so as to produce a vortex in the latter and ensure the raising of part of the precipitate into the raising chamber.
As a result of these features, it is apparent that the reaction chamber defined within the fixed cylinder of the apparatus according to the invention, behaves in substantially the same way as the chamber defined in the fixed vessel of the prior art vortex precipitation apparatus. However, the presence of a bowl rotating outside the fixed cylinder makes it possible to produce a centrifugal effect in the annular chamber defined between the bowl and the cylinder. This effect tends to agglomerate the precipitates which are denser than the solution outside the said space and only the solution is in contact with the outer wall of the fixed cylinder. This contact has the effect of breaking the liquid and making it drop again along the said wall. This recycling of the liquid permits the raising of the precipitate, whilst creating an upward stream on the outer periphery of the annular space. By accelerating the rotation of the rotary bowl, it is even possible to almost completely empty the apparatus.
Preferably, the blades of the turbine fixed to the bottom of the rotary bowl comprise a portion located above the lower end of the cylinder, so as to ensure a recycling of part of the precipitate into the reaction chamber, and a part located below the lower end of the cylinder, in such a way as to ensure the raising of part of the precipitate into the raising chamber.
In practice, the vortex apparatus according to the invention preferably comprises an outer enclosure integral with the fixed cylinder and supporting the rotary bowl, as well as means for driving the latter in a rotary manner. The outer enclosure comprises an annular collector into which the weir issues and an outlet pipe communicating with the collector. In the hypothesis that the products treated in the precipitator are radioactive products, this enclosure can also provide the neutron insulation of the apparatus.
According to a preferred embodiment of the invention, the fixed cylinder has recesses which receive the heating means, cooling means and/or control means. These heating, cooling and control operations can therefore be carried out directly within the solution and not outside the apparatus, as is generally the case in the prior art apparatus.
According to a secondary feature of the invention, the outer face of the fixed cylinder can be provided with ribs downwardly channeling the liquid which descends into the raising chamber in the vicinity of the cylinder as a result of the deceleration caused by the latter being stationary.
In order to accelerate the raising of the precipitate, the inner face of the rotary bowl is preferably upwardly divergent. In practice, the inner face of the rotary bowl can in its lower part form an angle in excess of 7° with the vertical, and over the remainder of its height an angle of approximately 1° with the vertical.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail hereinafter relative to non-limitative embodiments and the attached drawings, wherein show:
FIG. 1 a diagrammatic sectional view of a vortex precipitation apparatus according to the invention.
FIG. 2 a larger scale sectional view of the upper part of the apparatus of FIG. 1.
FIG. 3 a larger scale sectional view of the lower part of the apparatus of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus shown in the drawings is particularly suitable for the production of a precipitate in a radioactive medium. To this end, it comprises an enclosure in several parts 10a, 10b, said parts being respectively made from boron carbide and polythene in order to insulate the bowl from α-particles and neutrons. The inner part 10a of the enclosure defines a cavity 12 having a cylindrical configuration with a vertical axis. The cavity is extended at its lower end by a purge opening 14. A rotary bowl 16 is arranged coaxially within cavity 12. Bowl 16 has a lateral wall 18 and a bottom 20. Lateral wall 18 is extended upwards by a widened portion 21 mounted in rotary manner in part 10a by means of at least one bearing 22.
In the represented embodiment, there is only one bearing 22 and bottom 20 of bowl 16 is extended downwards so as to be received in rotary manner by means of a second bearing 28 in a nacelle 24 joined to enclosure 10a by fins 26. According to another not shown embodiment, bearing 28, as well as nacelle 24 can be eliminated in which case bearing 22 is duplicated. However, this solution has the disadvantage that it requires balancing of the bowl.
It can be seen in FIGS. 1 and 2 that the upper part 21 of bowl also defines a spur ring 30 which meshes with a pinion 32, whose vertical axis is parallel to the axis of bowl 16. The spindle of pinion 32 is rotated by a motor 34 fixed to the apparatus enclosure.
A hollow cylinder 36 is fixed, for example, by screws 38 to the upper end of the enclosure, which is coaxial to bowl 16. These screws 38 pass through a flange 40 covering the upper end 21 of bowl 16 and is then fixed by screws 41 to enclosure 10. The upper end of hollow cylinder 36 is sealed by a plug 42. Oblique supplied pipes 44 pass through the side wall of cylinder 36 and issue into the interior and at the upper end of the latter in the vicinity of its vertical axis.
As is shown in the drawings, the fixed cylinder 36 extends over most of the length of the rotary bowl 16 and ends in the vicinity of bottom 20. Thus, a reaction chamber 46 is defined within the fixed cylinder 36 and an annular raising chamber 48 is defined between the rotary bowl 18 and the fixed cylinder 36. These chambers are linked by a passage 49 between the lower end of cylinder 36 and bottom 20 of the rotary bowl.
In order to stir the mixture in reaction chamber 36 and assist the raising of the precipitate into annular chamber 48, bottom 20 of the rotary bowl 16 carries a turbine 50 constituted by blades arranged in vertical planes and radially with respect to the axis of the bowl and the vessel. More specifically, it can be seen that the blades of turbine 50 have a portion located above the lower end of fixed cylinder 36 and a portion located below said end. Thus, turbine 50 ensures the production of a vortex diagrammatically represented at 52 in FIGS. 1 and 2 in reaction chamber 46. Moreover, turbine 50 makes it possible to eject part of the mixture into annular chamber 48.
In order to facilitate the discharge of the precipitate towards annular chamber 48, the inner wall of bottom 20 of rotary bowl 16 is shaped like a cone whose apex is directed upwards. Moreover, the raising of the precipitate into annular chamber 48 is facilitated by the fact that the inner part of side wall 18 of rotary bowl 16 is slightly upwardly divergent. More specifically, the inner part of said wall is inclined relative to the vertical by an angle exceeding 7° over a height substantially equal to the height of turbine 50. The slope of the remainder of the wall is less and is preferably approximately 1°. This limited slope is justified both by the fact that the raising of the precipitate into annular chamber 48 is not due solely to this feature, as will be described hereinafter, and by the fact that a greater slope would increase the overall dimensions of the precipitator under conditions not satisfactory particularly from the standpoint of safety when the treated reactants have a radioactive nature.
In order to facilitate the recycling of the solution constituting, as will be shown hereinafter, the main element ensuring the raising of the precipitate into annular chamber 48, the outer surface of fixed cylinder 36 can be provided over its entire length with a helical rib 54 channeling the downward path of the solution along the said surface.
The chemical precipitation reaction taking place within the apparatus may require either heating or cooling of the reagents. It may also be necessary to control the reaction by means of appropriate probes. To this end and as is more particularly illustrated by FIGS. 2 and 3, recesses 56 are formed over the entire height of fixed cylinder 36, e.g. by providing the latter with a double wall. In addition to the cooling means, electrical heating resistors and control probes, recesses 56 can also be used to house discharge piping or neutrophage material when the nature of the reagents justifies it.
As shown in FIGS. 1 and 2, the upper end of annular chamber 48 forms an overflow issuing into weirs 58 formed in the divergent portion 21 of rotary bowl 16 and whereof only one is shown in the drawing. The lower end of these weirs issues into an annular collector 60 formed in part 10a of the outer enclosure. This annular collector 60 has a V-shaped section and its bottom is provided with at least one discharge pipe 62 traversing the outer enclosure for moving the precipitate formed outside the apparatus.
Finally, pipes 54, 66 and 68 pass through different parts of the enclosure in order to issue respectively into the space containing the spur ring 30, in the upper part of the annular collector 60 and at the upper end of the annular space defined between rotary bowl 16 and the outer enclosure. These pipes are used for the cleaning and decontamination of the apparatus, when it is used for treating radioactive reactants.
The apparatus described hereinbefore with reference to FIGS. 1 to 3 functions in the following way.
Each of the reactants is introduced into the upper end of reaction chamber 48 and in the vicinity of its axis by means of one of the intake pipes 44. This introduction takes place continuously. The rotation of bowl 16 and turbine 50 has the effect of creating a vortex, diagrammatically represented at 52. This vortex ensures the mixing of the reactants and the passage of the precipitate formed towards the bottom and in accordance with the axis of the apparatus, in the manner shown by the arrows in FIG. 1. The freshly formed precipitate is consequently moved away from the walls for a sufficient time to ensure its ageing. As this ageing is accompanied by a significant decrease in the adhesion of the precipitate, the latter has become relatively slightly adhesive by the time it becomes level with turbine 50. At this level, it can be seen in FIGS. 1 and 3 that part of the precipitate rises with the solution into chamber 46 along the inner wall of fixed cylinder 36 before redescending again along the axis under the effect of the vortex, as illustrated by the arrows. Another part of the precipitate and of the solution is laterally discharged by turbine 50 into passage 49 and then into annular chamber 48. As a result of the slight slope of the inner face of side wall 18 of rotary bowl 16, the radial force to which the precipitate is exposed under the action of turbine 50 gives rise to an upwardly directed vertical component, which tends to raise the precipitate along the said wall. Moreover, the rotation of bowl 16 subjects the dissolved precipitate to a centrifugal force, which tends to engage the precipitate, which is denser than the solution, with the inner face of wall 18 of the rotary bowl. Thus, the solution is localized in the part of the annular space 48 closest to the outer face of fixed cylinder 46. The stationary nature of the latter leads to the deceleration of the solution, which redescends along cylinder 36 under the effect of gravity forces. This descent of the solution is channeled by the helical rib 54. To this end, rib 54 preferably has a left-hand pitch when the rotation direction of rotary bowl 16 is the trigonometric direction corresponding to the direction of the natural vortex. This descent of the solution along the outer face of fixed cylinder 36 ensures a looped circulation of the liquids in annular space 48, as shown by the arrows in FIGS. 2 and 3. Thus, this looped circulation ensures the raising of the precipitate into space 48. In addition, this circulation also has the effect of cleaning the walls and reducing the static charge created by the rotation of the bowl. Thus, the precipitate and only a small part of the solution are discharged by weirs 58, which rotate with bowl 16. The precipitate then drops into fixed collector 60, from where it is discharged towards the outside of the apparatus by means of pipe 62. As the latter is positioned in the upper part of the apparatus, it is not necessary to subsequently raise the precipitate.
In order that the vortex 52 correctly fulfils its function, the rotation speed of bowl 16 must exceed 200 r.p.m. Preferably, a speed between 250 and 400 r.p.m. is chosen.
When a precipitation cycle is finished and it is necessary to empty the apparatus, the rotation speed of bowl 16 is increased to approximately 1000 r.p.m. The precipitator is then almost completely emptied, as a result of the inclination of the inner wall of the bowl. This total emptying is facilitated by a change of the rotation direction (reversed as compared with the trigonometric direction), which adds the helical effect to the centrifugal effect.
When the precipitation reaction is carried out at a temperature differing from the ambient temperature, it has been seen that the necessary heater can be constituted by electrical resistors located in recesses 56 of the fixed cylinder. The temperature obtained can be regulated by thermocouples, which are also placed in recesses 56.
The above description has shown that the precipitator according to the invention has numerous advantages compared with the known vortex precipitator, whilst ensuring the raising of the precipitate and its separation from the solution. | Vortex apparatus for the continuous production of a precipitate by reacting together at least two reactants wherein it comprises a rotary bowl, having a vertical axis a fixed cylinder arranged coaxially within the bowl in order to define with the latter an annular raising chamber, thus providing a fluid flow connection with a reaction chamber defined within the fixed cylinder, reactant inlet pipes issuing into the upper part of the reaction chamber in the vicinity of the axis of the bowl, at least one weir fixed to the rotary bowl at the upper end of the raising chamber and a turbine fixed to the rotary bowl in the lower part of the reaction chamber, so as to produce a vortex in the latter and ensure the raising of part of the precipitate into the raising chamber. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to the field of chairs or couches. More particularly, this invention relates to a couch or chair for supporting a human occupant in a predetermined posture which reduces both physical and mental stress thereby allowing for enhanced work productivity.
Present day work environments are based on traditional methods of dealing with paper data bases. Books, ledgers, papers and the like are often scattered around a work surface located at a suitable height for a person sitting upright. As electronic displays have been introduced into the workplace, these displays have been added to the desk top as a device which had to coexist with, rather than replace, the paper database This phenomenon has lead to numerous side effects to workers resulting from occupational stress which effectively reduces the very productivity improvements which the automation was intended to bring. Office workers have blamed the video display units for eye strain, muscular discomfort, backaches, emotional disorientation, anxiety and a general increase in stress levels.
However, it has been determined that many of these problems stemmed not from the video display unit, but from the physical relationship with the terminal. For example backache may be traced to poor posture, eye strain may be due to poor lighting and screen reflections, and stress may result from the intrusion of a video display unit in a work environment designed for paper management. These problems all result in an overall decrease in work productivity.
The chairs presently available for use in conjunction with electronic work stations have improved somewhat over the past ten years. These chairs offer improved ergonomics, aesthetics and modern materials. However, such contemporary chairs do not directly improve the work environment, but only aid in the worker's posture and comfort.
SUMMARY OF THE INVENTION
The above-discussed and other problems and disadvantages of the prior art are overcome by the chair or couch of the present invention. In accordance with the present invention, a couch is presented which supports the body in a relaxed posture. This Posture results in the worker enjoying enhanced improved overall concentration. The predetermined posture provided by the couch of the present invention is derived from the posture of a body in zero gravity (neutral body position) and the posture of a body in the savasana yoga position.
In zero gravity, no external forces act on the body, the muscles realign the posture so that the internal muscular forces are in equilibrium. The legs bend and float apart, the feet droop, the back curves, arms float up and away from the body, and the neck muscles bend the head forward. At rest, there are no internal or external forces acting on the body.
The yoga position of meditation called savasana (e.g. the corpse pose), has been practiced for thousands of years. In this position, the yogi lies flat on his back, with his body perpendicular to gravity's pull, and his legs and arms spread apart. The yogi then performs a combination of rhythmic breathing, stretching and relaxation exercises.
The posture achieved by the chair of the present invention combines the neutral body position and the savasana body Position to produce a compromise position with gravity. Essentially, the chair of this invention supports the body so that the side view approximates the neutral body position, and the plan view reproduces the savasana position.
By lying in the couch, the user adopts the position of relaxation. The users legs are apart, the feet are dangling, the arms are resting along the arm rests, the body is reclining at 30° and the head is looking upwards. In this relaxed Position, the user can remain focused on a particular task for a much longer period of time.
If the user works for long periods of time at a video display unit, the couch of the present invention can help maintain the user's mental focus for greater lengths of time. This enhances the user's productivity and the productivity of the computer system. A feedback system which measures the user's level of stress may also be incorporated in the couch. This stress measurement system is based on the user's heart beat, body movements, breathing rate and the like. If, based on the user history, any of these measurements reach a predetermined level, relaxing music or a relaxation video tape will be provided to optimize the stress level.
The couch of the present invention consists of two principle parts including a suspension structure and a supporting cushion. The suspension structure provides a mechanical support system and the predetermined posture for the user. The cushion is cut from one piece of long memory foam and covered with soft material such as vinyl or leather. At first, the foam feels firm, but as it responds to body heat and pressure, it softens and the foam feels as if it is molding to the body. All human parts in contact with the chair are supported by the foam cushion.
The couch can be custom built to match the size and shape of the user and yet be produced at a reasonable cost. Modern manufacturing technology can be employed to custom produce the chair to the requisite parameters of the user/purchaser.
The above-discussed and other features and advantages of the present invention will be apparent to and understood by those skilled in the art from the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now the the drawings, wherein like elements are numbered alike in the several FIGURES:
FIG. 1 is a profile view of a human body in the neutral body position;
FIG. 2 is a ventral view of a human body in the neutral body position of FIG. 1;
FIG. 3 is a profile view of a human body in the yoga savasana position;
FIG. 4 is a ventral view of a human body in the yoga savasana position of FIG. 3;
FIG. 5 is a profile view of a human body as seated in the couch or chair of the present invention;
FIG. 6 is a ventral view of the human body as seated in the couch or chair as shown in FIG. 5;
FIG. 7 is the profile view of a human body shown in FIG. 5;
FIG. 8 is a side elevation view of a cushion for the couch of the present invention;
FIG. 9 is a side elevation view of a frame for the couch of FIG. 8;
FIG. 10 is a ventral view of the human body of FIG. 5,
FIG. 11 is a top elevation view of the cushion of FIG. 8;
FIG. 12 is a top elevation view of the frame of FIG. 9;
FIG. 13 is a top elevation view of the couch of the present invention;
FIG. 14 is a back elevation view of the couch of FIG. 13;
FIG. 15 is a side elevation view of the couch of FIG. 13;
FIG. 16 is a front elevation view of the couch of FIG. 13;
FIG. 17 is a bottom elevation view of the couch of FIG. 13;
FIG. 18 is a top elevation view of an alternate embodiment of the couch of the present invention;
FIG. 19 is a back elevation view of the couch of FIG. 18;
FIG. 20 is a side elevation view of the couch of FIG. 18;
FIG. 21 is a front elevation view of the couch of FIG. 18;
FIG. 22 is a bottom elevation view of the couch of FIG. 18;
FIG. 23 is a top elevation view of another alternate embodiment of the couch of the present invention;
FIG. 24 is a back elevation view of the couch of FIG. 23;
FIG. 25 is a side elevation view of the couch of FIG. 23;
FIG. 26 is a front elevation view of the couch of FIG. 23;
FIG. 27 is a bottom elevation view of the couch of FIG. 23; and
FIG. 28 is a diagram of a bio-feed back loop for use with the couch of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIGS. 1 and 2, a human body is shown in the neutral body position or posture. This is the position the body takes when it is relaxed in a zero gravity environment. In zero gravity, no external forces act on the body. As a result, the muscles realign the posture so that internal muscular forces are in equilibrium. In the neutral body posture, the legs bend and float apart, the feet droop, the back curves, the arms float up and away from the body, and the neck muscles bend the head forward. When at rest there are no internal or external forces acting on the body. It will be appreciated that astronauts who have experienced zero gravity have expressed a deep sense of relaxation when floating in this physical equilibrium (sometimes for hours at a time).
Still referring to FIG. 1, in the neutral body posture (e.g. a relaxed state in zero gravity), an angle A is formed between the foot and the calf, with its axis point at the ankle. Angle A measures about 111°±7°. An angle B is formed between the calf and the thigh, with its axis point at the knee. Angle B has a measurement of about 135°±8°. An angle C is formed between the thigh and the torso, with its axis point at the hip. Angle C has a measurement of about 128°±7°. An angle D is formed between the upper arm and the torso, with its axis point at the shoulder. Angle D has a measurement of about 36°±19°. An angle E is formed between the forearm and the upper arm, with its point of axis at the elbow. Angle E has a measurement of about 122°±24°. An angle F is formed between the neck and the torso, with its point of axis at essentially the shoulder. Angle F has an angle of 25°±6°.
Referring to FIG. 2, an angle G is formed between the central axis of the body (the line which runs from the nose, to the belly button, to the crotch) and the thigh. Angle G has a measurement of about 12°±6°. An angle H is formed between the central axis line and the upper arm. Angle H has a measurement of about 39°±11°.
Referring now to FIGS. 3 and 4, a representation of a human body is shown lying in the yoga savasana position. This position (also called the corpse pose) is a yoga position of meditation used for thousands of years. In this position, the yogi lies flat on his back, with his body perpendicular to gravity's pull, and his legs and arms spread comfortably apart. At this point, the yogi performs a combination of rhythmic breathing, stretch and relaxation exercises. The result is a state of enlightened relaxation that is both meditative and exhilarating; and which can be maintained for prolonged periods of time. It will be appreciated that the savasana position of FIGS. 3 and is the equivalent of the neutral body position of FIGS. 1 and 2 in a gravitational environment. The force of gravity comprises the relaxation which can be achieved in a zero gravity environment. In essence, the savasana position is a two dimensional relaxation position rather than a three dimensional relaxation position. In other words, in savasana position, the body is forced by gravity to lie flat, rather than in the folded position of the Neutral Body posture. Comparing the posture of FIGS. 1, 2 to the posture of FIGS. 3, 4, it will be appreciated that while the difference in respective angles A-F are quite distinct, angle G of FIG. 4 (having a measurement of 12°±6°) is substantially the same as angle G in the neutral body position. Angle H in FIG. 4 is 10°±5°, while angle H of FIG. 2 is 39°±11°. This difference is a direct result of the effect of gravity.
Now referring to FIGS. 5 and 6, a human body is shown as it would be positioned in a couch or chair produced in accordance with the present invention. The couch or chair of the present invention supports the human body in a manner that merges or combines the neutral body position of FIGS. 1 and 2 and the savasana position of FIGS. 3 and 4 to produce a compromise posture. The chair or couch is designed for use in a gravitational field. It will be appreciated that the gravitational field can range in gravitational force from 0 upwards. However, the couch of the present invention creates a profiled posture in which only slight differences exist between it and the body in the neutral body posture. In the posture of the present invention, angle B varies about 2° and angle D varies about 36°. In essence, the body while seated in the couch of the present invention, has the profiled orientation of a body at rest in a zero-gravity environment, while in the ventral (plan) view the body as shown in FIG. 6 has identical angles G and H as does the body in the savasana position shown in FIG. 4.
It will be appreciated that the couch of the present invention provides the three-dimensional relaxation of zero gravity, yet utilizes the time tested yoga savasana position used in a gravity environment to achieve a couch which provides maximum relaxation while in a gravitation environment.
Referring now to FIGS. 7-17, a couch in accordance with the present invention will now be described in detail. The preferred embodiment of the couch of the present invention is shown generally at 10 in FIGS. 13-17. Couch 10 comprises a frame 12 and a cushion 14. It will be noted that from the top view (FIGS. 11, 12 and 13), couch 12 has a wedge configuration, narrow at the head and wide at the feet, so that the user's legs and arms can be spread apart.
Frame structure 12 provides the mechanical support system for cushion 14 which, in turn, provides the necessary posture for the user. Frame 12 preferably consists of two sheets of aluminium 15a and 15b which mate together at a seat 16, and are held in place with a plurality of fasteners 18. Fasteners 18 fasten a pair of arm rests 20 to a back rest 22. A tension cable 24 is positioned between sheets 15a and 15b at ground level to balance the forces in structure 12. Structure 12 has a certain degree of elasticity which enables a limited amount of rocking to take place about a fulcrum 26 located at the base of the users spine. Couch or chair 10 will respond to movement imparted by the user and provide a limited but gentle rocking motion.
In a preferred embodiment sheet 15a includes a slot 17 which receives a tab 19 from sheet 15b. Tab 19 and a lower portion 21 of sheet 15a together form the support legs for frame 12. Arms are integral to sheet 15b and are attached by fasteners 18 to sheet 15a (see FIG. 14). Preferably, sheets 15a and 15b are made of aluminium which is anodized to a military specification in black. Alternatively, sheets 15a and 15b may be comprised of other materials (e.g. wood or other metals) which may or may not be painted or otherwise coated. This provides long term protection against scraping and corrosion, and allows the chair structure to be left outside. Fasteners 18 and cable 24 are preferably made from stainless steel or toher non-corrosive materials.
Cushion 14 should preferably be cut from a single piece of long memory foam and covered with a soft flexible synthetic or natural material such as leather. Cushion 14 can include a head rest 15. Preferably, foam 14 comprises a foamed polymeric material such as CONFOR FOAM manufactured by Specialty Composites, Inc. Long memory foam initially feels firm, but as it responds to body's heat and pressure, the foam softens and feel as if it is molding to the body. Thus, cushion 14 distributes pressure equally over the contact surface of the body and reduces or eliminates pressure points.
It will be appreciated that the combination of distributed pressure loading and absence of pressure points enables the body to remain immobile for prolonged periods of time. Use of memory foam also reduces the need for thick layers of foam, so that the cushion need only have a thickness of about one inch. This reduces material cost and enhances the aesthetics of chair 10. Long memory foam is surface sealed, so it is pleasant to the skin. Thus, cushion 14 could be sold without a cover, although a cover is preferred, if memory foam is used as the cushion material.
Referring to FIGS. 7-9 it can be seen how cushion 14, frame 12 and the human body merge together. Cushion 14 is separable from frame 12. Cushion 14 is simply laid on top of frame 12 and is held in place with Velcro straps (not shown) or some other like fastening means. Thus, cushion 14 can be easily removed for cleaning, changed to match decor, or upgraded to a higher quality covering material. Cushion 14 may also be removed and used as a floor mat. Cushion 14 may also be transferred to different structures such as shown in FIGS. 13-27.
It will be appreciated that other support structures may be incorporated into the present invention to provide individualized ergonomics. These additional support structures include, but are not limited to, ergonomically shaped head and neck rests, inflatable lumbar support balloons, and other secondary products.
It is noted that frame 12 is designed individually so as to provide the proper posture shown in FIGS. 5 and 6. Frame 12 and cushion 14 are angled in a manner to achieve the ideal posture as seen in FIGS. 8 and 9.
Referring now to FIGS. 18-22, an alternate embodiment of the couch of the present invention is shown generally at 30. Couch 30 provides the angular orientation of couch 10 which will support the user in the manner contemplated in FIGS. 5 and 6 (i.e. the cross between the neutral body position of zero gravity and the yoga savasana position of a gravity environment). Couch 30 also comprises a frame 32 and cushion 34. Cushion 34 is identical to cushion 14 of couch 10 and is attached to frame 12.
Frame 32 of couch 30 differs in several respects from frame 12 of couch 10. Frame 32 uses flat elongated sheets 35a and 35b as a base 36. Sheets 35a and 35b are slightly arched to provide couch or chair 30 with a slight rocking motion.
Frame 32 is constructed of three pieces including base sheets 35a, 35b and seat section 40. Base sheets 35a and 35b are each flattened elongated sheets of metal, preferably anodized aluminium as discussed above, joined at the ends to form an irregular shaped ring. Located directly above base 36 is an arm section 40. Arm section 40 is the section of couch 30 on which the arm of the user rests.
A seat section 42 comprises the remainder of frame 32. Seat section 42 is the section of frame 32 on which the body of the user rests. Section 42 is bent at angles to support the users body in the posture shown in FIGS. 5 and 6.
It will be appreciated that the configuration of chair 30 allows a user to rock slightly while he or she relaxes. In some instances, this may further deepen his concentration.
Referring now to FIG. 23-27, yet another alternate embodiment of the couch of the present invention is shown generally at 50. Couch 50 is comprised of a frame 52 and a cushion 54. Cushion 54 is fundamentally the same as cushions 14 and 34 while the Frame 52 of couch 50 will place the user's body in the posture of FIGS. 5 and 6. Frame 52 also differs from frames 12 and 32. Frame 52 has two independent legs 56a and 56b which support main chair frame 58. Legs 56a and 56b are attached to main chair frame 58 at the front of couch 50. Legs 56a and 56b are attached by a plurality of fasteners 60 to frame 58. Thus, while the user sits in chair 50, he or she will experience a certain springiness caused by the manner in which frame 52 is assembled.
While several embodiments of the chair of the present invention have been described, several more embodiments are easily envisioned. Thus, an important feature of this invention is not how the chairs or couches are assembled, but rather that the chair and cushion assembly support the users body as contemplated in FIGS. 5 and 6.
Still another feature of the chair of the present invention is the provision of reduced load on the user's spine. Accordingly, the present invention will assist in the reduction of back pain.
Some additional accessories are contemplated for use with the chair of this invention in addition to those previously mentioned. An important accessory which aids in relaxation is a bio-feed back system as shown in FIG. 28. In the system of FIG. 28, an accelerometer or similar transducer 70 is attached to the back of chair 72. Accelerometer 70 measures movements, such as chair movements, breathing rate, heart beat and the like. These measurements are compared against a historic collection of measurements stored in a microprocessor 74. A positive increase in the number of movements, breathing rate, or heart beat, signal the chair user is under stress. Once determined the user is under stress, microprocessor 74 signals a video recorder, software program or a music/speech synthesizer to begin showing user relaxing visual displays and providing the user with relaxing music. As the user's movement, breathing rate, and heart beat are optimized, the stimulation is removed and the user can continue to relax and work at a computer screen if preferred.
The accelerometer/processor system can also be used for non-contacting patient monitoring of breathing rate, heart beat and the like, for use in patient care in hospitals, rest homes, etc.
The apparatus of the present invention can be manufactured by standard mass production methods. An alternate method involves collecting anthropomorphic data from the user, and using this data to custom build the chair or couch.
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 illustrations and not limitation. | A chair or couch is presented which supports the person using it in a predetermined relaxation position. The position merges the neutral body position (the position the body takes in zero gravity) with the savasana yoga position (the position used for thousands of years by yogi to reach enhanced meditative relaxation). The chair of the present invention is characterized by a pre-selected profile configuration and a preselected ventral configuration. In profile, the user's body takes on the angles found in the profile of the neutral body position. In the ventral view, the user's body has the same angles as in the savasana yoga position. | 0 |
This application is a continuation-in-part of International Application PCT/JP00/04858 filed Jul. 19, 2000 (not published in English) which is incorporated herein by this reference.
BACKGROUND OF THE INVENTION
This invention relates to therapeutic and prophylactic agents for neoplasms which comprise a fused heterocyclic compound or a pharmaceutically acceptable salt thereof as an active ingredient; to the use of such a compound in the preparation of a medicament for the treatment and prevention of neoplasms; and to a method for treatment and prevention of neoplasms which comprises administering a pharmaceutically effective amount of such a compound to a warm-blooded animal (preferably a human).
The term ‘neoplasms’ in this specification includes sarcoma, various cancers, and leukemia, which include fibrosarcoma, liposarcoma, osteosarcoma, angiosarcoma, cancers of the lung, the stomach, the large intestine, the breast, the prostate gland, the kidney, the liver, the pancreas, the esophagus, the tongue, the pharynx, the bladder and ovary, brain tumors, acute leukemia, chronic leukemia, and lymphoma.
The compounds which are useful for the present invention and general methods of preparing these compounds are described in Japanese Patent Application Publication Hei 9-295970, EP 0745600 and U.S. Pat. No. 5,886,014 (all incorporated by reference). However, these descriptions about these compounds do not disclose their suppressive effects against proliferation of cancer cells. Further, these compounds have been disclosed as therapeutic or prophylactic agents for diabetes mellitus or hyperlipidemia; thus, the prior art documents differ from the present invention.
Compounds having the benzimidazole ring group are disclosed in WO 99/18081. However, the fused hetero ring has phenoxy, phenylthio, pyridyloxy or pyridylthio groups as substituents. The present invention compounds do not have such substituents.
Numerous compounds are commercially available as chemotherapeutic agents for cancer. However, it has become clear that the efficacy of currently available chemotherapeutic agents against various cancers is sometimes insufficient, i.e., in some cases cancer cells have developed natural tolerance against the therapeutic agents. Further, some therapeutic or prophylactic agents exert side effects, or make cancer cells gain tolerance during clinical use. Therefore, clinical use of chemotherapeutic agents for cancers has been complicated. Under these circumstances, novel anticancer agents have always been desired in cancer chemotherapy.
The problem to be solved by the present invention is to provide novel anticancer agents to satisfy the desire described above.
The inventors have earnestly carried out research on the synthesis of fused heterocyclic compounds, pharmaceutically acceptable salts thereof, and their pharmacological activity in order to solve this problem. The inventors have found that some fused heterocyclic compounds exhibit excellent suppressive effects against proliferation of cancer cells and that they are excellent therapeutic and prophylactic agents for cancer.
BRIEF SUMMARY OF THE INVENTION
This invention comprises a therapeutic and prophylactic agent for neoplasms which comprises as active ingredient a fused heterocyclic compound of formula (I) or a pharmaceutically acceptable salt thereof:
wherein
X is a benzimidazolyl group which is optionally substituted with 1 to 5 substituents selected from Group A;
Y is an oxygen or sulfur atom;
Z is a group selected from the following formulae:
(hereinafter, these groups are referred to as i) 2,4-dioxothiazolidin-5-ylidenylmethyl, ii) 2,4-dioxothiazolidin-5-ylmethyl, iii) 2,4-dioxooxazolidin-5-ylmethyl, iv) 3,5-dioxooxadiazolidin-2-ylmethyl and v) N-hydroxyureidomethyl groups, respectively);
R is hydrogen, straight or branched chain C 1 -C 6 alkyl, straight or branched chain C 1 -C 6 alkoxy, halogen, hydroxyl, nitro, amino which is optionally substituted with one or more substituents selected from Group B and straight or branched chain C 7 -C 11 aralkyl which is optionally substituted with one or more substituents selected from Group C;
m is an integer from 1 to 5 inclusive;
Group A comprises straight or branched chain C 1 -C 6 alkyl, straight or branched chain C 1 -C 6 alkoxy, straight or branched chain C 7 -C 11 aralkyloxy, halogen, hydroxyl, straight or branched chain C 1 -C 11 aliphatic acyloxy, straight or branched chain C 1 -C 6 alkylthio, straight or branched chain C 1 -C 6 halogenoalkyl, nitro, amino which is optionally substituted with one or more substituents selected from Group B, C 6 -C 10 aryl which is optionally substituted with one or more substituents selected from Group C, and straight or branched chain C 7 -C 11 aralkyl which is optionally substituted with one or more substituents selected from Group C;
Group B comprises straight or branched chain C 1 -C 6 alkyl, straight or branched chain C 7 -C 11 aralkyl, C 6 -C 10 aryl, straight or branched chain C 1 -C 11 aliphatic acyl, C 8 -C 12 aromatic aliphatic acyl and C 7 -C 11 aromatic acyl; and
Group C comprises straight or branched chain C 1 -C 6 alkyl, straight or branched chain C 1 -C 6 alkoxy, halogen, hydroxyl, nitro, C 6 -C 10 aryl, straight or branched chain C 1 -C 6 halogenoalkyl, and amino which is optionally substituted with one or more substituents selected from Group B.
DETAILED DESCRIPTION OF THE INVENTION
Preferred compounds of formula (I) are:
(1) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein X is benzimidazolyl which is optionally substituted with 1 to 3 substituents selected from Group A;
(2) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein X is benzimidazolyl which is optionally substituted with two substituents selected from Group A;
(3) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein Y is an oxygen atom;
(4) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein Y is a sulfur atom;
(5) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein Z is 2,4-dioxothiazolidin-5-ylmethyl or 2,4-dioxooxazolidin-5-ylmethyl;
(6) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein Z is 2,4-dioxothiazolidin-5-ylmethyl;
(7) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein R is hydrogen, straight or branched chain C 1 -C 4 alkyl, straight or branched chain C 1 C 4 alkoxy, halogen, hydroxyl, nitro, amino, or straight or branched chain C 7 -C 11 aralkyl;
(8) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein R is hydrogen;
(9) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein m is an integer from 1 to 3 inclusive;
(10) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein m is 1;
(11) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein Group A comprises straight or branched chain C 1 C 6 alkyl, straight or branched chain C 1 C 6 alkoxy, straight or branched chain C 7 -C 11 aralkyloxy, halogen, hydroxyl, straight or branched chain C 1 -C 7 aliphatic acyloxy, straight or branched chain C 1 C 6 alkylthio and straight or branched chain C 7 -C 11 aralkyl;
(12) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein Group A comprises straight or branched chain C 1 -C 4 alkyl, straight or branched chain C 1 C 4 alkoxy and straight or branched chain C 7 -C 11 aralkyloxy;
(13) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein Group A comprises methyl, methoxy and benzyloxy;
(14) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein Group B comprises straight or branched chain C 1 C 4 alkyl, straight or branched chain C 7 -C 11 aralkyl and straight or branched chain C 1 -C 7 aliphatic acyloxy; and
(15) a fused heterocyclic compound or a pharmaceutically acceptable salt thereof wherein Group C comprises straight or branched chain C 1 -C 4 alkyl, straight or branched chain C 1 C 4 alkoxy, halogen, hydroxyl, straight or branched chain C 1 -C 4 halogenoalkyl and amino.
In addition, a preferred compound, which is included in the scope of compounds of formula (I), is a fused heterocyclic compound of formula (II) or a pharmaceutically acceptable salt thereof:
wherein X is benzimidazolyl which is optionally substituted with 1 to 5 substituents selected from Group A′; and
Group A′ comprises straight or branched chain C 1 -C 6 alkyl, straight or branched chain C 1 -C 6 alkoxy, straight or branched chain C 7 -C 11 aralkyloxy, halogen, hydroxyl, straight or branched chain C 1 -C 7 aliphatic acyloxy, straight or branched chain C 1 -C 6 alkylthio and straight or branched chain C 7 -C 11 aralkyl.
In the compound of formula (II), the number of substituents selected from Group A′ is preferably from 1 to 3 and more preferably 2. In the compound of formula (II), the preferred Group A′ is a group described in (12) or (13) above which is a preferred group of the substituent Group A.
Typical compounds of this invention are listed below in JP HEI-9-295970 and in U.S. Pat. No. 5,886,014 (especially Tables in columns 24-141). However, the scope of the invention is not restricted by these compounds.
5-[4-(1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione;
5-[4-(6-methoxy-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione;
5-[4-(5-methoxy-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione;
5-[4-(1-benzyl-1-H-benzimidazol-5-ylmethoxy) benzyl]thiazolidine-2,4-dione;
5-[4-(5-hydroxy-1,4,6,7-tetramethyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione;
5-[4-(5-acetoxy-1,4,6,7-tetramethyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione;
5-[4-(6-benzyloxy-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione;
5-[4-(6-chloro-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione;
5-[4-(6-methylthio-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione; and pharmaceutically acceptable salts thereof.
A salt of the compound of formula (I) can be prepared by a conventional method. Examples of the salt include hydrohalogenic acid salts such as hydrofluoride, hydrochloride, hydrobromide and hydroiodide; inorganic acid salts such as nitrate, perchlorate, sulfate and phosphate; alkanesulfonic acid salts such as methanesulfonate, trifluromethanesulfonate and ethanesulfonate; arylsulfonic acid salts such as benzenesulfonate and p-toluenesulfonate; amino acid salts such as glutamate and aspartate; and carboxylic acid salts such as acetate, fumarate, tartrate, oxalate, maleate, malate, succinate, benzoate, mandelate, ascorbate, lactate, gluconate and citrate. Preferred salts are hydrohalogenic acid salts such as hydrofluoride, hydrochloride, hydrobromide and hydroiodide and a more preferred salt is hydrochloride.
In addition, when the compound of formula (I) has a phenolic hydroxyl group, a metal salt of the compound can be prepared by a conventional method. Examples of the salt include alkali metal salts such as lithium, sodium and potassium salts; alkaline earth metal salts such as calcium, barium and magnesium salts; and inorganic salts such as an aluminum salt.
The compounds of this invention can exist in various isomeric forms. For example, certain fused heterocyclic compounds of formula (I) have asymmetric carbon(s) on the thiazolidine or oxazolidine ring and also have asymmetric carbon(s) on the substituent(s) of said compound of formula (I). Such compounds can exist as optical isomers.
Certain fused heterocyclic compounds of formula (I) can exist as stereoisomers having (R) and (S) configuration(s) on each asymmetric carbon. The present invention encompasses each pure stereoisomer and a mixture of the isomers in any ratio. A pure stereoisomer of the fused heterocyclic compound of formula (I) can be synthesized from an optically active starting material or can be obtained from a mixture of synthesized fused heterocyclic compounds of formula (I) via a conventional optical resolution technique.
When certain fused heterocyclic compounds of formula (I) are allowed to stand in the air or recrystallized, such compounds absorb or adsorb water to form a hydrate. Such hydrates are encompassed in the scope of this invention.
In addition, certain fused heterocyclic compounds of formula (I) may absorb a solvent to form a solvate. Such solvates are also encompassed in the scope of this invention.
This invention encompasses a compound (prodrug) which converts into a fused heterocyclic compound of formula (I) or a pharmaceutically acceptable salt thereof in vivo. When the fused heterocyclic compound of formula (I) has a phenolic hydroxy group, a prodrug of the compound of formula (I) is a compound wherein the hydroxyl group is protected by a protecting group that can be cleaved by a biological process such as hydrolysis in vivo.
A protecting group that can be cleaved by a biological process such as hydrolysis in vivo is a group that is capable of being cleaved by a biological process to afford a compound having a free phenolic hydroxyl group or a salt thereof. Whether a compound of formula (I) has a protecting group that can be cleaved by a biological process can easily be determined. The hydroxy-protected compound of formula (I) under investigation is intravenously administered to a test animal such as a mouse or rat and the body fluids of the test animal are thereafter studied. If the parent compound of formula (I) having a free phenolic hydroxyl group or a salt thereof is detected in the body fluids of the test animal, the hydroxy-protected compound of formula (I) under investigation is judged to be a prodrug of the compound of formula (I).
Examples of such protecting groups include 1-(lower aliphatic acyloxy) lower alkyl groups such as formyloxymethyl, acetoxymethyl, propionyloxymethyl, butyryloxymethyl, pivaloyloxymethyl, 1-formyloxyethyl, 1-acetoxyethyl, 1-propionyloxyethyl, 1-butyryloxyethyl and 1-pivaloyloxyethyl; (lower alkoxycarbonyloxy)alkyl groups such as methoxycarbonyloxymethyl, ethoxycarbonyloxymethyl, propoxycarbonyloxymethyl, isopropoxycarbonyloxymethyl, butoxycarbonyloxymethyl, isobutoxycarbonyloxymethyl, 1-(methoxycarbonyloxy)ethyl, 1-(ethoxycarbonyloxy)ethyl, 1-(propoxycarbonyloxy)ethyl, 1-(isopropoxycarbonyloxy)ethyl, 1-(butoxycarbonyloxy)ethyl, 1-(isobutoxycarbonyloxy)ethyl and 1-(t-butoxycarbonyloxy)ethyl; and phthalidyl groups such as phthalidyl, dimethylphthalidyl and dimethoxyphthalidyl.
When the group Z in the compound of formula (I) is 2,4-dioxothiazolidin-5-ylmethyl, 2,4-dioxooxazolidin-5-ylmethyl, 2,4-dioxothiazolidin-5-ylidenylmethyl or 3,5-dioxooxadiazolidin-2-ylmethyl, these groups can exist in various tautomeric forms respectively. Examples of these tautomers are shown below.
The compounds of formula (I) include each tautomer and a mixture of tautomers. Each tautomer and a mixture of tautomers are encompassed in the scope of this invention.
Dosage forms for the compounds of formula (I) include tablets, capsules, granules, powders or syrups for oral administration; and injections, suppositories and eyedrops for parenteral administration. These dosage forms can be prepared by a method known to those skilled in the art using additives such as excipients, lubricants, binders, disintegrants, stabilizers, corrigents and diluents. Examples of excipients include organic excipients, for example, sugar derivatives such as lactose, white soft sugar, glucose, mannitol and sorbitol; starch derivatives such as corn starch, potato starch, α-starch, dextrin and carboxymethylstarch; cellulose derivatives such as crystalline cellulose, low-substituted hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, calcium carboxymethylcellulose, internally cross-linked sodium carboxymethylcellulose; gum arabic; dextran; pullulan; inorganic excipients, for example, silicate derivatives such as light silicic anhydride, synthetic aluminum silicate and magnesium aluminate metasilicate; phosphates such as calcium phosphate; carbonates such as calcium carbonate; and sulfates such as calcium sulfate.
Examples of lubricants include stearic acid; metal stearates such as calcium stearate and magnesium stearate; talc; colloidal silica; waxes such as beeswax and spermaceti; boric acid; adipic acid; sulfates such as sodium sulfate; glycol; fumaric acid; sodium benzoate; DL-leucine, sodium salts of fatty acids; lauryl sulfates such as sodium lauryl sulfate and magnesium lauryl sulfate; silicic acid derivatives such as silicic acid anhydride and silicic acid hydrate; and the starch derivatives described above.
Examples of binders include polyvinylpyrrolidone, macrogol (trade mark) and the excipients described above.
Examples of disintegrants include the excipients described above and chemically modified starches and celluloses such as sodium croscarmellose, sodium carboxymethylstarch; and cross-linked polyvinylpyrrolidone.
Examples of stabilizers include paraoxybenzoates such as methylparaben and propylparaben; alcohols such as chlorobutanol, benzyl alcohol and phenethyl alcohol; benzalkonium chloride; phenol derivatives such as phenol and cresol; thimerosal; dehydroacetic acid; and sorbic acid.
Examples of corrigents include sweeteners, souring agents, and flavoring agents which are usually used.
The dose of the compound of formula (I) or pharmaceutically acceptable salt thereof will vary depending on a variety of factors such as the age, symptoms of the patient and the route of administration. A suitable dosage level for oral administration is from 0.01 mg (preferably 0.1 mg) per day as a lower limit to 2000 mg (preferably 500 mg, more preferably 100 mg) per day as an upper limit for a patient (warm-blooded animal, particularly a human) and the dosage is administered either as a single unit dosage or divided into several times throughout the day depending on the symptoms of the patient. A suitable dosage level for intravenous administration is from 0.001 mg (preferably 0.01 mg) per day as a lower limit to 500 mg (preferably 50 mg) per day as an upper limit for an adult (particularly an adult human), and the dosage is administered either as a single unit dosage or divided into several times throughout the day depending on the symptoms of the patient.
The following Examples, Reference Examples, Test Examples and Formulation Examples are intended to further illustrate the present invention and are not intended to limit the scope of this invention in any manner.
EXAMPLES
Example 1
5-[4-(6-Methoxy-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione hydrochloride
A mixture of 5-[4-(6-methoxy-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione (10.6 g) and 4N hydrochloric acid in 1,4-dioxane (100 ml) was stirred at room temperature for 1 hour. The reaction mixture was concentrated, and to the residue was added ethyl acetate to form a precipitate. The precipitate was collected by filtration and washed with ethyl acetate to afford the title compound (11.0 g).
melting point: 275-277° C.
1 H NMR spectrum (DMSO-d 6 , 400 MHz, δ ppm): 3.11 (1H, dd, J=14 Hz and 9 Hz), 3.34 (1H, dd, J=14 Hz and 4 Hz), 3.89 (3H, s), 3.98 (3H, s), 4.91 (1H, dd, J=9 Hz and 4 Hz), 5.64 (2H, s), 7.14 (2H, d, J=9 Hz), 7.15 (1H, d, J=9 Hz), 7.25 (2H, d, J=9 Hz), 7.50 (1H, s), 7.70 (1H, d, 9 Hz), 12.04 (1H, s, signal disappeared on addition of D 2 O).
Example 2
5-[4-(6-Benzyloxy-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione hydrochloride
2-1
N-[2-[4-(2,4-dioxothiazolidin-5-ylmethyl)phenoxyacetylamino]-5-benzyloxyphenyl]-N-methylcarbamic acid t-butyl ester
To a mixture of N-(2-amino-5-benzyloxyphenyl)-N-methylcarbamic acid t-butyl ester (2.29 g) (obtained in Reference Example 1), 4-(2,4-dioxothiazolidin-5-ylmethyl)phenoxyacetic acid (1.96 g) (obtained in Reference Example 6), triethylamine (0.97 ml) and anhydrous tetrahydrofuran (100 ml) was added diethyl cyanophosphonate (1.06 ml) and the resulting mixture was stirred at room temperature for 29 hours. The reaction mixture was concentrated and the residue partitioned between ethyl acetate and water. The ethyl acetate layer was dried over anhydrous sodium sulfate and evaporated in vacuo to give the crude desired product (4.27 g). 2—2
5-[4-(6-Benzyloxy-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione hydrochloride
N-[2-[4-(2,4-Dioxothiazolidin-5-ylmethyl)phenoxyacetylamino]-5-benzyloxyphenyl]-N-methylcarbamic acid t-butyl ester (4.27 g) (obtained in Example 2-1) was dissolved in 4N hydrochloric acid in dioxane (30 ml) and the resulting mixture was allowed to stand at room temperature for 19 hours. The reaction mixture was concentrated and to the residue was added ethyl acetate to form crystals. The crystals were washed with ethyl acetate and dried in vacuo to afford the title compound (4.27 g).
melting point: 202-205° C.
Example 3
5-[4-(6-Chloro-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione hydrochloride
3-1
N-[2-[4-(2,4-Dioxothiazolidin-5-ylmethyl)phenoxyacetylamino]-5-chlorophenyl]-N-methylcarbamic acid t-butyl ester
To a mixture of N-(2-amino-5-chlorophenyl)-N-methylcarbamic acid t-butyl ester (2.50 g) (obtained in Reference Example 2), 4-(2,4-dioxothiazolidin-5-ylmethyl)phenoxyacetic acid (3.01 g) (obtained in Reference Example 6), triethylamine (1.49 ml) and anhydrous tetrahydrofuran (50 ml) was added diethyl cyanophosphonate (1.75 g) and the resulting mixture was stirred at room temperature for 10 hours. The reaction mixture was concentrated and the residue partitioned between ethyl acetate and water. The ethyl acetate layer was washed with saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate and evaporated in vacuo. The resulting residue was chromatographed on a silica gel column using n-hexane/ethyl acetate (2/1) as the eluant to give the desired product (3.26 g). R f =0.41 (thin-layer chromatography on a silica gel plate using n-hexane/ethyl acetate (2/3) as the eluant).
3-2
5-[4-(6-Chloro-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione hydrochloride
N-[2-[4-(2,4-Dioxothiazolidin-5-ylmethyl)phenoxyacetylamino]-5-chlorophenyl]-N-methylcarbamic acid t-butyl ester (3.16 g) (obtained in Example 3-1) was dissolved in dioxane (30 ml). To the solution was added 4N hydrochloric acid in dioxane (30 ml) and the resulting mixture was stirred at room temperature for 3 hours and allowed to stand overnight. The reaction mixture was filtered and the crystals were washed with ethyl acetate and dried in vacuo to afford the title compound (2.44 g). softening point: 301-303° C.
Example 4
5-[4-(6-Methylthio-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione hydrochloride
4-1
N-[2-[4-(2,4-Dioxothiazolidin-5-ylmethyl)phenoxyacetylamino]-5-methylthiophenyl]-N-methylcarbamic acid t-butyl ester
To a mixture of N-(2-amino-5-methylthiophenyl)-N-methylcarbamic acid t-butyl ester (2.0 g) (obtained in Reference Example 4), 4-(2,4-dioxothiazolidin-5-ylmethyl)phenoxyacetic acid (2.31 g) (obtained in Reference Example 6), triethylamine (1.14 ml) and anhydrous tetrahydrofuran (40 ml) was added diethyl cyanophosphonate (1.34 g) and the resulting mixture was stirred at room temperature for 4 hours and allowed to stand overnight. To the reaction mixture were further added 4-(2,4-dioxothiazolidin-5-ylmethyl)phenoxyacetic acid (0.84 g), triethylamine (0.3 g) and diethyl cyanophosphate (0.49 g) and the resulting solution was stirred at room temperature for 1.5 hours. At the end of this time the reaction mixture was concentrated and the residue was partitioned between ethyl acetate and water. The ethyl acetate layer was washed with saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate and evaporated in vacuo. The resulting residue was chromatographed on a silica gel column using n-hexane/ethyl acetate (2/1) as the eluant to give the desired product (3.54 g).
4-2
5-[4-(6-Methylthio-1-methyl-1H-benzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione hydrochloride
N-[2-[4-(2,4-Dioxothiazolidin-5-ylmethyl)phenoxyacetylamino]-5-methylthiophenyl]-N-methylcarbamic acid t-butyl ester (2.54 g) (obtained in Example 4-1) was dissolved in dioxane (25 ml). To the solution was added 4N hydrochloric acid in dioxane (25 ml) and the resulting mixture was stirred for 30 minutes at room temperature and allowed to stand for two nights. The reaction mixture was filtered and the crystals were washed with ethyl acetate and dried in vacuo to afford the title compound (2.98 g). softening point: 247-249° C.
Reference Example 1
N-(2-Amino-5-benzyloxyphenyl)-N-methylcarbamic acid t-butyl ester
To anhydrous DMF were added benzyl alcohol (2.48 ml) and 55% NaH (1.05 g) and then N-(2-nitro-5-chlorophenyl)-N-methylcarbamic acid t-butyl ester (5.73 g) was added in small portions. The resulting mixture was stirred at room temperature for 2 hours. The reaction mixture was concentrated and the residue partitioned between ethyl acetate and water. The extract was dried over anhydrous sodium sulfate and concentrated. The resulting residue was stirred in a mixture of dioxane (100 ml), water (10 ml), sodium hydrosulfite (20.9 g) and sodium hydrogencarbonate (21.0 g) at room temperature for 1 hour. The reaction mixture was partitioned between ethyl acetate and water and the extract was dried over anhydrous sodium sulfate and concentrated. The resulting residue was chromatographed on a silica gel column using ethyl acetate/n-hexane (1/2) as the eluant to afford the title compound (2.29 g). melting point: 86-89° C.
Reference Example 2
N-(2-Amino-5-chlorophenyl)-N-methylcarbamic acid t-butyl ester
A mixture of N-(2-nitro-5-chlorophenyl)-N-methylcarbamic acid t-butyl ester (6.0 g), dioxane (150 ml), water (30 ml), sodium hydrosulfite (14.6 g) and sodium hydrogencarbonate (17.6 g) was heated under reflux for 30 minutes. The reaction mixture was partitioned between ethyl acetate and water. The extract was washed with saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate and then concentrated. The residue was chromatographed on a silica gel column using ethyl acetate/n-hexane (1/3) as the eluant to afford the title compound (2.98 g). R f =0.23 (thin-layer chromatography on a silica gel plate using ethyl acetate/n-hexane (1/3) as the eluant).
Reference Example 3
N-(2-Nitro-5-methylthiophenyl)-N-methylcarbamic acid t-butyl ester
To a suspension of sodium thiomethoxide (1.47 g) in anhydrous tetrahydrofuran (50 ml) was added dropwise a solution of N-(2-nitro-5-chlorophenyl)-N-methylcarbamic acid t-butyl ester (6.0 g) in anhydrous tetrahydrofuran (120 ml) while cooling at 0° C. The resulting mixture was stirred at 0° C. for 30 minutes and at room temperature for 1 hour. At the end of this time anhydrous DMF (30 ml) was added and the resulting mixture stirred at room temperature for 1 hour. DMF (20 ml) was added and then sodium thiomethoxide (0.73 g) and further DMF (50 ml) were added. The resulting mixture was stirred at room temperature for 7 hours. The reaction mixture was concentrated in vacuo and the residue was partitioned between ethyl acetate and aqueous sodium hydrogencarbonate solution. The extract was washed with saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate and concentrated to afford the desired compound (6.15 g).
Reference Example 4
N-(2-Amino-5-methylthiophenyl)-N-methylcarbamic acid t-butyl ester
To a solution of N-(2-nitro-5-methylthiophenyl)-N-methylcarbamic acid t-butyl ester (obtained in Reference Example 3) in anhydrous methanol (120 ml) and anhydrous tetrahydrofuran (30 ml) was added 10% palladium on carbon (3.0 g). The resulting mixture was vigorously stirred under a hydrogen atmosphere. Further 10% palladium on carbon (1.5 g) was added after 2.5 hours and 4.5 hours of the reaction respectively. The resulting mixture was stirred at room temperature for 1.5 hours and allowed to stand overnight. 10% palladium on carbon (0.7 g) was further added to the reaction mixture, which was then stirred under a hydrogen atmosphere for 1 hour. At the end of this time the 10% palladium on carbon was filtered off and the filtrate concentrated in vacuo. The residue was chromatographed on a silica gel column using ethyl acetate/n-hexane (⅓) as the eluant to afford the desired compound (3.61 g). R f =0.24 (thin-layer chromatography on a silica gel plate using ethyl acetate/n-hexane (⅓) as the eluant).
Reference Example 5
4-(2,4-dioxo-3-tritylthiazolidin-5-ylmethyl)phenoxyacetic acid t-butyl ester
To a solution of 5-(4-hydroxybenzyl)-3-tritylthiazolidine-2,4-dione (20.0 g) in acetonitrile (200 ml) was added cesium carbonate (21.0 g), followed by the addition of bromoacetic acid t-butyl ester (7.4 ml). The resulting mixture was stirred at 25° C. for 3 hours. To the reaction mixture was added water and the organic layer was separated and concentrated in vacuo. The residue was extracted with toluene and the extract was washed with diluted hydrochloric acid and water and concentrated in vacuo to afford the desired compound (24.9 g).
IR spectrum (KBr, νcm −1 ): 1754, 1691, 1512, 1300, 1218, 1155, 740. 1 H NMR spectrum (CDCl 3 , 400 MHz, δ ppm): 1.48 (9H, s), 3.04 (1H, dd, J=14.2, 9.0 Hz), 3.43 (1H, dd, J=14.2, 3.9 Hz), 4.36 (1H, dd, J=9.0, 3.9 Hz), 6.83 (2H, d, J=8.5 Hz), 7.11 (2H, d, J=8.5 Hz), 7.15-7.35 (15H, m).
Reference Example 6
4-(2,4-dioxothiazolidin-5-ylmethyl)phenoxyacetic acid
To a solution of 4-(2,4-dioxo-3-tritylthiazolidin-5-ylmethyl)phenoxyacetic acid t-butyl ester (6.2 g) (obtained in Reference Example 5) in toluene (25 ml) was added p-toluenesulfonic acid monohydrate (204 mg). The resulting mixture was heated under reflux for 3 hours. Ethyl acetate (10 ml) was added while heating and then the mixture stirred at 25° C. for 1.5 hours. The resulting crystals were collected by filtration to afford the desired compound (2.5 g).
IR spectrum (KBr, νcm −1 ): 3435, 3011, 1753, 1693, 1513, 1244, 1203. 1 H NMR spectrum (DMSO-d 6 , 400 MHz, δ ppm): 3.04 (1H, dd, J=14.2, 9.0 Hz), 3.30 (1H, dd, J=14.2, 4.3 Hz), 4.63 (2H, s), 4.86 (1H, dd, J=9.0, 4.3 Hz), 6.84 (2H, d, J=8.7 Hz), 7.15 (2H, d, J=8.7 Hz), 11.20 (1H, s), 12.94 (1H, br.s).
Test Example
Test Example 1
Antitumor Effects upon Human Large Intestine Cancer Cells COL-2-JCK.
Human cancer cells from the large intestine, COL-2-JCK (moderately differentiated adenocarcinoma), purchased from the Central Institute for Experimental Animals, were employed in the Test Example of the present invention as the solid tumor strain. The proliferated CLO-2-JCK cells were cultured and used for the experiments in our laboratory. In order to subculture the strain of the cancer cells and to test compounds in the experiments, the cancer cells were cultured with D-MEM/F-12 culture medium containing bovine fetal serum (manufactured by GIBCO Co.).
The test was carried out as follows: COL-2-JCK cells growed confluently on a petri dish for culture of cells (inner diameter 100 mm) were removed from the petri dish by using EDTA and 0.05% trypsin solution, and diluted to 100 cells/ml cell density with the culture medium. 3 ml of the diluted cell solution was then placed into each well of a 6-well plate (300 cells/well). At the same time, the test compound dissolved in DMSO solution was added so as to be 1, 10, 100 nM, 1 and 10 μM of the final concentrations to each well. The final concentration of the DMSO solution was adjusted to 0.1%. DMSO solution (0.1%) alone was placed in wells of the control group. After addition of the test compound, the cells were incubated in the presence of 5% CO 2 gas for 10 days at 37° C. After incubation was terminated, each well containing the cells was washed once with Dulbecco phosphate buffer saline (bivalent ion minus). Then 1 ml of 10% neutral formalin solution containing 0.02% crystal violet was added to the well and left for 5 minutes in order to stain the cells. After the dye was fixed, the cells were washed with water and air-dried. The total colony area (mm 2 ) of dye-fixed tumor cells was calculated by using an image analyzer of PCA-11 (manufactured by SystemSience Co.).
TABLE 1
Total colony area (mm 2 ) of tumor cells
Test compound
final concentrations of the test compound
Example No.
0
1 nM
10 nM
100 nM
1 μM
10 μM
1
3311
2795
2018
1352
933
768
Test Example 2
Antitumor Effect on Human H69 Lung Cancer Cells.
A piece (5 mm×5 mm) of human lung affected by H69 strain of lung cancer was subcutaneously inoculated in a group of 10 BALB/c nude mice (female, 6 weeks old). The test compounds were suspended in 5% emulsified saline containing 2.5% dimethylacetamide. They were orally administered once a day for 24 times in total, i.e., from the first day after the inoculation to the 4th day, from the 7th to the 11th day, from the 14th to the 18th day and from the 21st to the 25th day and from the 28th to the 32nd day after inoculation.
The short diameter (mm) and the long diameter (mm) of the tumor were measured with an electronic digital caliper square on the 39th day after inoculation. The efficacy of the test compound was evaluated by calculation of the inhibitory growth rate of the tumor (GI %) according to the following equation:
GI (%)=(1 −A/B )×100
A: average tumor volume on the 39th day after inoculation in the group treated with the test compound (*)
B: an average tumor volume on the 39th day after inoculation in the non-treated group (*)
*: The tumor volume indicates ½×(long diameter of the tumor)×(short diameter of the tumor) 2 .
The results are summarized in Table 2.
TABLE 2
Test compound
dose (mg/kg)
GI (%)
Example 1
10
57
Test Example 3
Antitumor Effects on Human MKN-74 Stomach Cancer Cells.
A piece (5 mm×5 mm) of human stomach affected by MKN-74 strain of stomach cancer was subcutaneously inoculated in a group of 10 BALB/c nude mice (female, 6 weeks old). The test compounds were suspended in 5% emulsified saline containing 2.5% dimethylacetamide. They were orally administered once a day for 24 times in total, i.e., from the first day after inoculation to the 4th day, from the 7th to the 11th day, from the 14th to the 18 th day, from the 21st to the 25th day and from the 28th to the 32nd day after the inoculation.
The short diameter (mm) and the long diameter (mm) of the tumor were measured with an electronic digital caliper square on the 35th day after inoculation. The efficacy of the test compound was evaluated by calculation of the inhibitory growth rate of the tumor (GI %) in a similar to those described above in Test Example 2.
TABLE 3
Test compound
dose (mg/kg)
GI (%)
example 1
10
76
Test Examples 1-3, show inhibitory activities against proliferation of the tumor cells. Therefore it is expected that compounds of the present invention will be potent prophylactic and therapeutic agents for cancers.
In particular, the compound of Example 1 of the present invention suppressed the proliferation of human stomach cancer cells to a remarkable extent, as shown by Test Example 3. This activity leads to the expectation of activity as a prophylactic and therapeutic agent for stomach cancer in warm blooded animals, especially in humans.
Formulation Examples
Formulations containing the compounds having general formula (I) or their salts as active ingredient can be prepared, for example, as follows:
Formulation Example 1
Powder
A powder can be made by pulverizing and mixing 4 g of 5-[4-(6-methoxy-1-methylbenzimidazol-2-ylmethoxy)benzyl]thiazolidine-2,4-dione hydrochloride (the compound of Example 1, hereinafter referred to as “compound A”), 10 g of polyvinylpyrrolidone, and 0.5 g of hydroxypropylmethylcellulose (trade mark: TC-5E; manufactured by Shin-etsu Chemical Industries Co.) by using an oscillatory mill for 30 min.
Formulation Example 2
Capsule
Twenty grams of compound A and 20 g of polyvinylpyrrolidone are dissolved in a mixture of 100 g of acetone and 100 g of ethanol. Granules can be obtained by aerification of the mixed solution with 200 g of sodium croscarmellose. 0.1 g of hydroxypropylmethylcellulose (Trade name: TC-5E, manufactured by Shin-etsu Chemical Industries Co.) and 1.9 g of lactose are mixed with 10 g of the granules. Filling a gelatin-made capsule with 0.24 g of the mixture affords a capsule. Each capsule contains 0.1 g of compound A.
Formulation Example 3
Tablet
One gram of the compound A and 1 g of polyvinylpyrrolidone are dissolved in mixture of 5 g of acetone and 5 g of ethanol. The organic solvent was then removed under reduced pressure by using a rotary evaporator. Fine granules are obtained by pulverization of the solid material obtained. One gram of the fine granules was mixed with 0.25 g of crystalline cellulose, 0.25 g of low substituted hydroxypropylcellulose, 0.05 g of hydroxypropylmethylcellulose (Trade name: TC-5E, manufactured by Shin-etsu Chemical Industries Co.), 0.18 g of lactose and 0.2 g of magnesium stearate. The tablets can be formed by use of a tabletting machine.
The fused heterocyclic compounds of formula (I) of this invention or pharmaceutically acceptable salts thereof exhibit excellent inhibitory activity against cancer-cell proliferation and are useful as agents for inhibiting cancer-cell proliferation in warm blooded animals, especially in humans.
Therefore, the fused heterocyclic compounds of formula (I) of this invention and pharmaceutically acceptable salts thereof are useful as therapeutic and prophylactic agents for cancers (especially, cancers of the large intestine, lung and stomach) in warm blooded animals, especially in humans. | This invention relates to therapeutic and prophylactic agents for neoplasms which comprise a fused heterocyclic compound or a pharmaceutically acceptable salt thereof as an active ingredient; to the use of such a compound in the preparation of a medicament for the treatment and prevention of neoplasms; and to a method for treatment and prevention of neoplasms which comprises administering a pharmaceutically effective amount of such a compound to a warm-blooded animal (preferably a human). | 2 |
FIELD OF THE INVENTION
This invention relates to hanger assemblies for suspending heavy objects such as ceiling fans, and particularly to a hanger assembly that may be easily installed to bridge the distance between two beams or joists. The hanger assembly will easily accommodate beams or joists spaced at various offsets.
BACKGROUND OF THE INVENTION
The National Electrical Code currently specifies a maximum acceptable weight of 80 pounds for ceiling light fixtures and 70 pounds for ceiling fans. It is therefore important to provide proper support for these potentially heavy devices to accommodate the static and, in the case of ceiling fans, dynamic loads that are encountered.
Light fixtures and ceiling fans are commonly mounted centrally on the ceiling of a room, and, in most cases, the exact center of a room does not coincide with the location of an overhead beam or joist from which to suspend the fixture. It therefore becomes necessary to provide overhead support in the exact center of the room from which to anchor the fixture or fan. Contractors typically provide overhead support by cutting a 2″×4″ header to the proper size to bridge the distance between overhead joists and then fastening it to the joists with nails or screws.
Typically, in new home construction, the building is framed out well before the electrical contractor arrives to install ceiling fans, light fixtures, and other electrical devices. It therefore becomes impractical and inconvenient for an electrical contractor to carry a cutting device to the work site. A need therefore exists for a device and method to easily provide overhead support for a heavy hanging object such as a light fixture or a ceiling fan.
For installation of light fixtures and ceiling fans in existing homes, many manufacturers produce expandable fixture support units that are inserted through the normal junction box hole in a ceiling to save the effort of creating a larger hole. A typical fixture support unit of this type is disclosed in U.S. Pat. No. 4,463,923 to Reiker (hereinafter the '923 patent). This patent describes a heavy-duty expansible junction box hanger assembly adapted for installation from beneath a ceiling through a junction-box aperture in the ceiling without complete prior removal of a previously installed light-weight hanger assembly. The portion of the light-weight hanger directly above the aperture is cut away, and the heavy duty hanger is maneuvered through the aperture to a position above the light-weight hanger. A pair of feet on each end of the heavy duty hanger straddle the light-weight hanger and rest on the upper ceiling surface, aligning the heavy duty hanger parallel to the ceiling, after which joist engagement means on the hanger assembly are expanded into biting contact with the joists.
Although the '923 patent and similar devices provide an adequate device for providing overhead support for a heavy fixture, it and similar devices have the disadvantage of being composed of a number of mechanical parts, thereby making it a complex device that is relatively expensive to manufacture. It is limited to bridging a minimum distance of 14.25″. Additionally, if the existing overhead joists are not arranged parallel to each other, no provision is made for squaring the junction box with the room. A need therefore exists for a simple, relatively inexpensive device for providing overhead support for a heavy hanging object such as a light fixture or a ceiling fan. Additionally, the device should be capable of bridging a wide range of distances between joists and allow for easy squaring of junction boxes with the room in which they are to be installed.
SUMMARY OF THE INVENTION
The present invention comprises a hanger assembly comprised of a longitudinal member and end brackets attached to and pivotable with respect to the member. The length of the longitudinal member is selected to span the maximum distance typically encountered with overhead joists and beams. The hanger assembly provides the advantages of being of simple construction, inexpensive, capable of spanning a wide range of distances between joists, and allowing easy squaring of junction boxes with the room in which they are installed.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the preferred embodiment of the hanger assembly with the longitudinal member in phantom lines and having a portion broken away.
FIG. 2 is a bottom view of one of the end brackets of the hanger assembly depicted in FIG. 1 .
FIG. 3 is a side view of one end of the hanger assembly of FIG. 1 .
FIG. 4 is an end view of one of the end brackets of the hanger assembly of FIG. 1 .
FIG. 5 is a bottom view showing the arrangement of the hanger assembly of FIG. 1 when used to span between joists spaced 24 inches apart.
FIG. 6 is a bottom view showing the arrangement of the hanger assembly of FIG. 1 when used to span between joists spaced 18 inches apart.
FIG. 7 is a bottom view showing the arrangement of the hanger assembly of FIG. 1 when used to span between joists spaced 16 inches apart.
FIG. 8 is a bottom view showing the arrangement of the hanger assembly of FIG. 1 when used to span between joists spaced 12 inches apart.
FIG. 9 is a side view depicting the hanger assembly of FIG. 1 installed between two joists and including an attached junction box and a ceiling fan.
INDEX TO REFERENCE NUMERALS IN DRAWINGS
10 hanger assembly
12 longitudinal member
14 end bracket
16 top (of longitudinal member)
18 bottom (of longitudinal member)
20 end flange
22 top flange
24 bottom flange
26 vertical tab
28 horizontal tab
30 channel
32 pivot pin
34 flathead screw
36 locking nut
38 aperture (in bottom flange)
40 aperture (in longitudinal member)
42 aperture (in top flange)
44 joist-accepting seat
46 aperture
48 joist
50 junction box
52 ceiling fan
54 ceiling
56 lower edge (of joist)
58 fastener
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 and FIG. 3, the preferred embodiment of a hanger assembly 10 according to the present invention includes a longitudinal member 12 and two end brackets 14 pivotably attached thereto. The hanger assembly 10 , when placed into use, will be oriented as shown in FIG. 1, with the reference numeral 16 referring to the top and the reference numeral 18 referring to the bottom of the longitudinal member 12 . The end brackets 14 are essentially U-shaped and consist of an end flange 20 and a top 22 and bottom 24 flange. A vertical tab 26 extends vertically from the junction of the end 20 and top 22 flange and a horizontal tab 28 extends horizontally from the junction of the end 20 and bottom 24 flange. The inside portion of the U-shaped end brackets 14 form a channel 30 capable of accepting the longitudinal member 12 therein. As shown in FIG. 3, a pivot pin 32 , consisting of a flathead screw 34 and a locking nut 36 pivotably secure end bracket 14 to longitudinal member 12 through aperture 38 in the bottom flange 24 , aperture 40 in longitudinal member 12 , and aperture 42 in top flange 22 . As shown on the far left of FIG. 3, a joist-accepting seat 44 is created on the outward surfaces of the horizontal tab 28 , end flange 20 , and vertical tab 26 .
Referring to FIG. 2, an end bracket 14 is shown as viewed from the bottom 18 side of the longitudinal member 12 (shown in FIG. 1) and depicts the bottom flange 24 and the end of the flathead screw 34 which, in conjunction with the locking nut (not shown), form the pivot pin 32 that will secure the longitudinal member (not shown) rotatably to each end bracket 14 .
FIG. 4, an end view of one of the end bracket 14 as viewed from the left side of FIG. 1, depicts the vertical tab 26 and end flange 20 both of which include apertures 46 for receipt of fasteners (not shown) for later securing the hanger assembly between overhead joists. Apertures 46 are included in the horizontal tab 28 (not shown), vertical tab 26 , and end flange 20 for the receipt of fasteners (not shown) during installation of the hanger assembly 10 .
For the preferred embodiment of the hanger assembly 10 , the length of the longitudinal member 12 is 21.5 inches and the end brackets 14 extend the overall length, with the end brackets 14 arranged orthogonal to the longitudinal member 12 , of the hanger assembly 10 to 22.5 inches. The length of the longitudinal member 12 could be set longer than 21.5 inches, but typically the preferred length is sufficient to span most overhead joists, which typically are spaced at 24 inches or less center to center. The preferred width of the longitudinal member is 1.5 inches and the preferred height between the top 16 and bottom 18 is 3.5 inches.
FIGS. 5 through 8 are bottom views of the preferred embodiment of the hanger assembly 10 , viewed from the perspective of looking upwards at the overhead joists, illustrating the arrangement of the preferred embodiment of the hanger assembly 10 when used to span between adjacent joists 48 spaced at various distances. For example, as shown in FIG. 5, when used to span between adjacent joists 48 spaced 24 inches apart center to center (c/c), the end brackets 14 are pivoted orthogonal to the longitudinal member 12 and the longitudinal member 12 therefore is orthogonal to the joists 48 . Referring to FIG. 6 as a second example, with the adjacent joists 48 spaced at 18 inches c/c, the end brackets 14 are pivoted as shown to the longitudinal member 12 and the longitudinal member 12 therefore is at an angle of approximately 45° to the joists 48 . As depicted in the third example of FIG. 7, with the adjacent joists 48 spaced at 16 inches c/c, the end brackets 14 are pivoted as shown to the longitudinal member 12 and the longitudinal member 12 therefore is at an angle of approximately 37° to the joists 48 . For a final example, as depicted in FIG. 8, with the adjacent joists 48 spaced at 12 inches c/c, the end brackets 14 are angled as shown to the longitudinal member 12 and the longitudinal member 12 therefore is at an angle of approximately 25° to the joists 48 . As suggested by the various examples depicted in FIGS. 5 through 8, the preferred embodiment of the hanger assembly 10 of the present invention can easily span a wide range of joist geometries including spans of 4.0 inches c/c to 24.0 inches c/c. Smaller or larger distances may be spanned by varying the length or width of the longitudinal member 12 from the dimensions selected for the preferred embodiment.
Referring to FIG. 9, a side view is shown of the preferred embodiment of the hanger assembly 10 installed between two joists 48 with an attached junction box 50 and a ceiling fan 52 secured thereto. FIG. 9 includes a ceiling 54 , typically consisting of dry wall, secured to the lower edge 56 of the joists 48 . To install a light fixture (not shown) or a ceiling fan 52 between two existing overhead joists 48 , a hanger assembly 10 is provided and the end brackets 14 are pivoted with respect to the longitudinal member 12 until the total length of the hanger assembly 10 spans the distance between the two joists 48 . The hanger assembly 10 is then inserted between the two joists 48 such that, referring to FIG. 1, the joist-accepting seat 44 of each end bracket 14 is flush against its respective joist 48 . Referring again to FIG. 9, fasteners 58 are then hammered or threaded through apertures 46 in the horizontal tab 28 , vertical tab 26 , or end flange 20 as appropriate to secure the hanger assembly 10 to the joists 48 . When secured to the joists 48 , the horizontal tab 28 is flush against the lower edge 56 of the joists 48 and therefore a ceiling 54 , typically consisting of sheet rock, may be secured to the lower edge 56 of the adjacent joists 48 and other joists in the vicinity to cover the joists. Alternatively, the hanger assembly 10 may be used to suspend a heavy object from two adjacent rafters where the rafters in the room are visible. In this case, the hanger assembly 10 would be used to provide support between two adjacent rafters and no covering material such as sheet rock would be used.
After the hanger assembly 10 is secured to the joists 48 with fasteners 58 , as shown in FIG. 9, an appropriate junction box 50 is secured to the hanger assembly 10 in the usual manner. The junction box 50 may be of a circular shape that is typically used with hanging light fixtures or ceiling fans or may be of the L-shaped type or of the type that contains a U-shaped channel in the top of the junction box to accommodate an overhead joist. The electrical wiring and the installation of the light fixture or ceiling fan 52 are then completed in the typical manner.
The preferred material of construction for the end bracket is {fraction (1/16)}″ thick pre-galvanized steel, however, it should be understood that the end brackets may be provided in various gauges without departing from the scope of the invention. The material of construction of the end brackets can also consist of various other materials such as rigid plastic, aluminum, titanium, fiberglass, etc., without departing from the scope of the invention.
The longitudinal member is preferably constructed from a typical piece of 2″×4″ wood such as that used for framing houses. It should be apparent that other materials, such as fiberglass, rigid plastic, steel, aluminum, or various other materials could also easily be used to construct the longitudinal member.
The preferred material for constructing a pivot pin is a ¼-20×4 long flathead screw and a mating lock nut. Other types, lengths, and diameters of cylindrical fasteners and locking means, or other means such as a cylindrical pin with a cotter key, may be used to connect the end brackets pivotably to the longitudinal member without departing from the scope of the invention.
Although the description above contains many specific descriptions, materials, and dimensions, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention.
Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given. | A hanger assembly comprised of a longitudinal member and end brackets attached to and pivotable with respect to the member. The length of the longitudinal member is selected to span the maximum distance typically encountered with overhead joists and beams. The hanger assembly provides the advantages of being of simple construction, inexpensive, capable of spanning a wide range of distances between joists, and allowing easy squaring of junction boxes with the room in which they are installed. | 4 |
This is a continuation of application Ser. No. 07/265,076, filed Oct. 31, 1988, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a semi-rigid plastic container which may be pre-filled with a highly heat-sensitive liquid food product after which the filled container may be retorted to sterilize the contents thereof. Most known semi-rigid plastic containers may not be retort-sterilized when filled with highly heat-sensitive liquid food products as the length of time and high temperatures required for such sterilization processes result in unacceptable deformation of such containers and/or damage to the highly heat-sensitive food products contained therein.
SUMMARY OF THE INVENTION
The present invention relates to a new and novel semi-rigid plastic container which, due to its structure, composition and method of fabrication, may be pre-filled with a highly heat-sensitive liquid food product and then retort-sterilized without container deformation and without damage to the contents thereof. These retort-sterilized containers will have a long shelf life whereby a hospital, nursing home or other health facility may maintain an inventory of easily storable, ready-to-use semi-rigid containers of sterilized nutritional products for tube-feeding of its patients. This unique container is formed by a coextrusion blow-molding process with the multi-layer coextrusion being characterized by at least one high-oxygen-barrier layer. The container is formed with a ribbed formation on one or more of the sidewalls thereof whereby to increase the heat transfer properties thereof and thus reduce the high-heat sterilization process time and thus the likelihood of container deformation and/or damage to the highly heat-sensitive contents thereof. The method of providing the sterilized pre-filled containers of liquid nutrient also includes the step of agitating the contents of the container during both the heat-up and cool-down cycles, as by rotating the pre-filled containers in the retort, to maximize the heat transfer characteristics thereof and also the step of pressurizing the retort during both the heat-up and cool-down cycles to minimize container deformation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of a retortable, coextrusion blow-molded, semi-rigid plastic container embodying the invention and shown in its upright position;
FIG. 2 is a rear elevational view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a side elevational view thereof;
FIG. 5 is a front elevational view thereof;
FIG. 6 is a bottom plan view thereof;
FIG. 7 is a front perspective view of the container of FIG. 1 when inverted and adapted for feeding a patient;
FIG. 8 is an enlarged fragmentary horizontal sectional view illustrating the layered structure of the container wall and taken generally along line 8--8 of FIG. 5; and
FIG. 9 is a fragmentary vertical sectional view taken generally along line 9--9 of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Historically, retortable containers had to be fabricated of glass or metal as plastics have relatively low thermal conductivity and low melting points. However, plastic containers do have greater consumer appeal than glass or metal containers and the previous concerns as to retortable plastic containers have now been overcome. Referring now to the drawings, a preferred form of a semi-rigid plastic container 10 embodying the present invention is shown in its upright filling or one of its storage positions in FIGS. 1-6. This container 10, because of its unique structure, composition, and method of fabrication, may be pre-filled with a highly heat-sensitive liquid medical nutritional product and then heated in a retort to sterilize said product. This retort-sterilized plastic container 10 of medical nutritional product has a long shelf life whereby hospitals, nursing homes, and other health facilities may maintain an inventory of easily storable, ready-to-use, semi-rigid, plastic containers of sterilized nutritional products for tube-feeding of its patients. The container 10 is preferably formed by a multi-layer co-extrusion blow-molding process, the characteristics and properties of which multi-layer co-extrusion will be described hereinafter.
As shown in FIGS. 1-6, the container 10 is generally rectangular in configuration and is characterized by a front wall 12, a rear wall 14, a pair of side walls 16, and a bottom wall 18. In the embodiment illustrated in the drawings, the transverse or horizontal dimensions of the front and rear walls 12 and 14 are substantially greater than that of the side walls 16. The upper portions of the four walls 12, 14, and 16, converge upwardly to define inwardly inclined portions, 12', 14', and 16' which define an open-topped generally cylindrical neck-portion 20 which may be provided with an annular rib 21. The neck portion 20 may be threaded for sealingly receiving a threaded cap 22 which may be spikable or piercable to receive a feeding tube set 24 (FIG. 7). Although not shown in the drawings, a foil cover is heat sealed over the open neck portion 20 immediately after filling of the container 10 in a manner well known in the medical art. As an alternative to the threaded cap 22, a plastic protective cap (not shown) may be snap-fitted over the neck portion 20 of the container 10. As an alternative to the feeding tube set 24, a feeding tube set which includes a cap having a foil-cutting plow may be used when preparing container 10 for tube-feeding of a patient.
A fixed or removable hanger 26 may be provided on the bottom wall 18 of the container 10 for supporting same in an inverted feeding position from a support bar 28 at a patient's bedside as shown in FIG. 7. The bottom wall 18 may be recessed, as at 30, to accommodate the hanger 26 when folded into an out-of-the-way position to permit upright support of the container 10 on a generally flat or level surface, as during storage thereof.
As illustrated in the drawings, the front and side walls 12 and 16 are characterized by a plurality of horizontally disposed offset ribbed formations 32 which serve to increase the surface area of the container 10 in direct contact with the contents thereof. As illustrated in FIG. 9, which is a vertical sectional view taken generally along line 9--9 of FIG. 5, the thickness of the walls in the rib formations 32 is substantially constant. The ratio of the surface area of a container to its fill volume is critical when high heat transfer rates are involved. The higher the ratio, the higher the heat transfer rate and the shorter the heat or cook time to reach sterility. Although the rear wall 14 could also be provided with similar offset ribbing, it is often preferred that one wall of such a container be left unribbed to provide an area for content and/or patient labeling.
With reference to FIG. 8, the multi-layered wall structure of the container 10 is characterized by inner and outer layers 34 and 36 both of which are of a food-grade polypropylene having a minimum thickness of 0.002 inches, a regrind layer 38 adjacent the outer layer 36, a pair of high temperature adhesive layers 40 and 42, such as 0.0015 inch polyolephin disposed adjacent the regrind layer 38 and the inner layer 34, respectively, and, between the two high temperature adhesive layers 40 and 42, an oxygen barrier layer 44 of ethyl-vinyl-alcohol (EVOH) having a thickness of from 0.0015 to 0.002 inches.
This new and unique method of providing pre-filled, sterilized, semi-rigid plastic containers 10 of highly heat-sensitive liquid medical nutritional products of the present invention comprises the basic steps of 1) forming the container 10, 2) filling and sealing the container 10, and 3) sterilizing the filled container 10 in a retort. The problems considered and overcome in producing this pre-filled, semi-rigid plastic container 10 of sterilized highly heat-sensitive liquid medical nutritional product included minimizing the length of the heating portion of the sterilization cycle so as to prevent damage to the various highly heat-sensitive nutritional products to be contained therein and also minimizing distortion of the semi-rigid, but relatively thin-walled, plastic containers 10 during the heat-up and cool-down cycles of the sterilization step of the method.
The fabrication step of the method comprises a co-extrusion blow molding process utilizing known apparatus with the multi-layer co-extrusion being characterized by at least one high-oxygen-barrier layer 44 and with the formed container 10 having wall portions provided with the offset ribbed formations 32 which effectively increase the surface area of container contact with the liquid contents thereof and thus the heat transfer rate whereby to minimize the length of the heating portion of the sterilization step.
The filling and sealing steps may be accomplished in a known manner by known apparatus with the filled container 10 being immediately sealed by a heat-sealed foil cover after which either a threaded cap 22 or a snap-on cap is provided over the foil seal.
The sterilization step comprises a heat-up portion in a known-type retort (not shown) and a cool-down portion in the same retort with both temperature and time being critical. With the heat-sensitive liquid nutritional products with which the containers 10 are filled, the maximum temperature in the retort should be limited to 275° F. The heating period may be minimized by agitating the contents of the container 10 during the heating cycle as by axial or end-to-end rotation of the containers 10 in the retort by any suitable known rotation means. It is noted that the offset ribbed formations 32, in addition to providing increased surface area for improving the heat transfer rate, also provide secondary agitation of the liquid contents of the container 10 during rotation thereof. This combination of agitation of the container contents and the greater surface area contact thereof with the container 10 due to the ribbed configuration of the container walls thus improves the heat transfer rate of the method and minimizes the possibility of damaging the highly heat-sensitive liquid nutritional products that could result from too long an exposure to the heat required for sterilization thereof. For example, some liquid nutritional products will degrade and caramelize upon extended exposure to high temperatures.
By pressurizing the interior of the retort by known methods, particularly during the cool-down cycle, any undesirable deformation of the relatively thin-walled container 10 is minimized.
While there has been shown and described a preferred embodiment of the invention, it would be obvious to those skilled in the art that changes and modifications may be made without departing from the invention, and it is intended by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention. | A multi-layer co-extrusion blow molded plastic container adapted to be filled with a heat-sensitive nutrient and then retorted at relatively high temperatures to sterilize the contents thereof, the contents being agitated by rotating the container while it is being retorted and certain of the side walls being ribbed to both increase the surface area of the container and thus the heat transfer properties thereof and to aid in agitation of the contents whereby to minimize the time period the heat-sensitive contents must be exposed to such high temperatures for sterilization thereof, and the method of providing such a sterile container of heat-sensitive nutrient. | 1 |
PRIORITY INFORMATION
This application claims priority from provisional application Ser. No. 60/759,877 filed Jan. 18, 2006, which is incorporated herein by reference in its entirety.
SPONSORSHIP INFORMATION
This application was made with government support awarded by DARPA under Grant No. HR0011-05-C-0027. The government has certain rights in the invention.
BACKGROUND OF THE INVENTION
The invention is related to the field of ring resonators, and in particular to Ge/Si resonator-based modulators for optical data communications in silicon photonics.
It is highly desired to have a field effect based modulator by using materials compatible with Si-CMOS platform. Ring resonators are gaining more and more interest due to its very small footprint (<a few tens μm), extremely high sensitivity to refractive index change, large extinction ratio and small power consumption. There are several reports on Si based ring modulators, where the refractive index change is induced by free carrier absorption.
It is well known that field effect devices are theoretically able to operate at the highest speed. Epitaxial SiGe on Si has been proposed for modulator devices by using Franz-Keldysh effects. However, there are several challenges needed to be solved in order to achieve workable ring modulator. First, Ge on Si is a high refractive index contrast system and its single mode dimension size is very small. Next, the index difference between Si and Ge is very large and it results in a very small coupling efficiency between Si waveguide and Ge (or SiGe) ring. Furthermore, depending on the operating composition of Si in SiGe, the Q-factor of Ge (or SiGe) ring could be low due to intrinsic absorption, which could result a low extinct ratio.
SUMMARY OF THE INVENTION
According to one aspect of the invention, there is provided an optical modulator structure. The optical modulator structure includes at least two waveguide structures for inputting and outputting an optical signal. At least one ring resonator structure provides coupling between the at least two waveguide structures. The at least one ring resonator structure includes Ge or SiGe.
According to another aspect of the invention, there is provided a method of performing optical modulation. The method includes using at least two waveguide structures for inputting and outputting an optical signal. Also, the method includes providing coupling between the at least two waveguide structures using at least one ring resonator structure, the at least one ring resonator structure comprising Ge or SiGe.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1B are schematic diagrams illustrating the inventive ring resonator modulator structure;
FIGS. 2A-2B are schematic diagrams illustrating another embodiment of the inventive ring resonator modulator structure;
FIG. 3 is a schematic diagram illustrating an embodiment of a ring resonator modulator structure having multiple ring resonators; and
FIGS. 4A-4B are graphs demonstrating the overall performance of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention provides a ring resonator modulator structures that utilizes either Ge or SiGe ring resonators. This allows for more compact ring resonator structures that can be used in modulator structures requiring less space and higher performance.
FIGS. 1A-1B show the inventive ring resonator modulator structure 2 . In particular, FIG. 1A shows a top view of the ring resonator modulator structure 2 and FIG. 1B shows a cross-section view of the ring resonator modulator structure 2 . The ring resonator modulator structure 2 includes a Ge or SiGe ring resonator structure 4 . A doped poly-Si layer 10 is formed on top of the ring resonator structure 4 and acts as the top contact. A Si substrate 12 with an opposite doping type acts as the bottom contact to provide the vertical field and RF signal.
Input and output waveguides 6 and 14 are located laterally next to the ring resonator structure 4 to provide lateral coupling between the input and output waveguides 6 and 14 and the ring resonator structure 4 . The waveguides 6 and 14 can include Si or SiON waveguide. Short channel waveguides 8 can be inserted into the input and output waveguides 6 and 14 at the area close to ring resonator structure 4 to enhance side coupling. The short channel waveguides 8 can comprise Ge or SiGe. The ring resonator structure 4 and the short channel waveguides 8 can be fabricated by selective growth of Ge or SiGe in a trench. Both TE and TM can be used to couple into and out of the waveguides 6 and 14 . A resonator with a Q on the order of 100 that permits ultrafast modulation speeds (resonant photon lifetime on the order of 160 fs) with adequate extinction ratio on the order of 3 to 4 dB.
FIGS. 2A-2B shows another embodiment of the inventive ring resonator modulator structure 20 . In particular, FIG. 2A shows a top view of the ring resonator modulator structure 20 and FIG. 2B shows a cross-section view of the ring resonator modulator structure 20 . The ring resonator modulator structure 20 includes a Ge or SiGe ring resonator structure 22 . The ring resonator structure 22 is formed on a dopant layer comprising two n-type regions and a p-type region formed between the n-type regions. The dopant layer 28 is formed on a Si substrate 26 .
Input and output waveguides 24 are located laterally on the edge to the ring resonator structure 22 to provide lateral coupling between the input and output waveguides 24 and the ring resonator structure 22 . The waveguides 24 can include Si or SiON waveguide. Both TE and TM can be used to couple into and out of the waveguides 24 . A resonator with a Q on the order of 100 that permits ultrafast modulation speeds (resonant photon lifetime on the order of 160 fs) with adequate extinction ratio on the order of 3 to 4 dB.
FIG. 3 show an embodiment of a ring resonator modulator structure 30 having multiple ring resonators 32 . The ring resonator modulator structure 30 is similar to the ring resonator modulator structure 2 discussed for FIG. 1 , except the ring resonator modulator structure 30 includes multiple ring resonator structures 32 . Input and output waveguides 34 are located laterally next to the ring resonator structures 32 to provide lateral coupling between the input and output waveguides 34 and the ring resonator structures 32 .
The waveguides 34 can include Si or SiON waveguides. A short channel waveguides 36 can be inserted into the input and output waveguides 34 at the area close to ring resonator structures 32 to enhance side coupling. The short channel waveguides 36 can comprise Ge or SiGe. The ring resonator structures 32 and the short channel waveguides 36 can be fabricated by selective growth of Ge or SiGe in a trench. Both TE and TM can be used to couple into and out of the waveguides 34 . A resonator with a Q on the order of 100 that permits ultrafast modulation speeds (resonant photon lifetime on the order of 160 fs) with adequate extinction ratio on the order of 3 to 4 dB.
FIGS. 4A-4B are graphs demonstrating the overall performance of the invention. FIG. 4A shows actual and theoretical results associated with the relationship between the extinction ratio, Q value, and insertion loss of a single ring resonator modulator structure. Graph 40 illustrates the theoretical results of Si ring resonator structure and graph 42 show actual results of Ge ring resonator structure used in accordance with the invention. There is significant lower insertion loss in graph 42 as compared to graph 40 . FIG. 4B shows actual and theoretical results associated with the relationship between the extinction ratio, Q value, and insertion loss of a multiple ring resonator modulator structure having multiple Si ring resonator structures, shown in graph 44 , and multiple Ge ring resonator structures, shown in graph 46 . The multiple Ge ring resonator structures show lower insertion loss as compared to the multiple Si ring resonator structures for the same range of extinction ratios. Thus, this proves the performance is increased using the structures described herein.
Inclusion of a larger ring radius modulator increases the extinction ratio, although the insertion loss also increases (though not linearly proportional). Insertion loss includes of two components: loss from non-unity (less than 100%) coupling into the microring, and loss from material absorption. A larger ring proportionally increases the extinction ratio given the increased interaction length; a larger ring increases the material absorption insertion loss but does not affect the non-unity coupling insertion loss. An improvement of the extinction ratio divided by insertion loss can thus be expected with a larger ring radius high-speed intensity modulator.
Inclusion of higher-order filters will also increase the extinction ratio with a likewise expense of increasing insertion loss. Racetrack resonators further improve the ring-waveguide coupling, resulting in a larger extinction ratio for a given insertion loss in the modulator.
Absorption and refractive index change of Ge or SiGe material under electric field has been modeled based on Franz-Keldysh effect, and has been experimentally confirmed. Full first-principles numerical simulations of a Ge/Si ring intensity modulator have confirmed the physical operation of the device and have been used to design the device for optimum performance. These full 3D Finite Difference Time Domain (FDTD) simulations have been used to identify the waveguide design parameters that will make the best modulator, based on realistic achievable Ge/Si material absorption values. Numerical simulations have also been used to determine the best polarization that works for several device geometries.
Various modulator geometries have been simulated to extract the insertion loss and the extinction ratio. The current design results illustrate an insertion loss of 4.31 dB and an extinction ratio of 3.31 dB. These values are for a geometry that consists of a microring modulator with a 5 μm diameter and a 0.15 μm ring-waveguide gap.
A resonator having a Q in the order of 100 corresponds to photon lifetimes of 160 fs (1.5 THz). The RC limited bandwidth of the device is well above 40GHz. The device operates at a low voltage of <3.3V and the power consumption is in the order of a few mW, compared to several W of LiNbO 3 or BaTiO 3 modulators currently used in telecommunications.
Also, the designed intensity modulator discussed here is directly compatible with the process flow of a germanium detector, permitting full optical channelizers in a monolithic silicon CMOS compatible chipset. The process flow to create this high-speed modulator is immediately compatible with CMOS process line foundries. The modulator is compact (in the order of 10× wavelengths or less in physical size), permitting high-density integration of photonic and electronic drivers and circuits on an identical materials platform.
Although the present invention has been shown and described with respect to several preferred embodiments thereof, various changes, omissions and additions to the form and detail thereof, may be made therein, without departing from the spirit and scope of the invention. | An optical modulator structure includes at least two waveguide structures for inputting and outputting an optical signal. At least one ring resonator structure provides coupling between the at least two waveguide structures. The at least one ring resonator structure includes Ge or SiGe. | 6 |
FIELD OF THE INVENTION
The present invention relates to electric current converter topologies comprising several induction coils.
BACKGROUND OF THE INVENTION
An electric current converter is a device which is used to control the electric current flowing between a current source and a load. A conventional electric converter topology basically comprises an electric switching device and a magnetic coupling means. In a known topology the switching device consists for instance of a MOSFET transistor and a diode, and the magnetic coupling means consists of an induction coil which is sometimes associated with an input or output electric filter.
In such a topology the transistor is controlled at a high switching frequency (e.g. 50 kHz) so as to be conducting in saturation for a determined fraction of a time period. The diode is conducting only during the time that the transistor is not conducting. The magnetic coupling means are sized so as to assure limited voltage and current ripple capability.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a family of converter topologies which offers a wide variety of topologies from which to select the optimum topology to suit any particular application.
The electric converters according to the invention comprise at least three reactive elements connected in series, and a switching device comprising a switching transistor operating at a high frequency so that it becomes conducting for a fraction of each period of said frequency. The transistor and the diode are connected to the connection points between the reactive elements so that the diode is conducting only when the transistor is non-conducting and so that it is non-conducting each time the transistor becomes conducting.
Other features of the invention will be apparent from the detailed description hereinafter, in which the invention is disclosed in detail with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a buck converter with non-inverted voltage and continuous input and output currents, wherein the three reactive elements are connected in series between an input terminal and an output terminal;
FIG. 2 is a schematic diagram of a buck converter with non-inverted voltage, wherein the three reactive elements are connected in series between an input terminal and a common terminal;
FIG. 3 is a schematic diagram of a non-inverted boost converter with continuous input and output currents, wherein the three reactive elements are connected in series between an input terminal and an output terminal;
FIG. 4 is a schematic diagram of a non-inverted boost converter with continuous input and output currents, wherein the three reactive elements are connected in series between a common terminal and an output terminal;
FIG. 5 is a schematic diagram of a non-inverted buck/boost converter with continuous input and output currents, wherein the three reactive elements are connected in series between an input terminal and a common terminal;
FIG. 6 is a schematic diagram of a non-inverted buck/boost converter with continuous input and output currents, wherein the three reactive elements are connected in series between an output terminal and a common terminal;
FIG. 7 is a modification of FIG. 5 wherein the two induction coils are replaced by two transformers;
FIG. 8 is a modification of FIG. 6 wherein the two induction coils are replaced by two transformers;
FIG. 9 is a schematic diagram of an inverted buck/boost converter with continuous input and output currents, wherein the three reactive elements are connected in series between an input terminal and an output terminal;
FIG. 10 is a schematic diagram of an inverted buck/boost converter, wherein the three reactive elements are connected in series between an input terminal and an output terminal;
FIG. 11 is a schematic diagram of an inverted buck/boost converter, wherein the three reactive elements are connected in series between an input terminal and an output terminal;
FIG. 12 is a schematic diagram of an inverted buck/boost converter, wherein the three reactive elements are connected in series between an input terminal and an output terminal;
FIG. 13 is a schematic diagram of an inverted buck/boost converter, wherein the three reactive elements are connected in series between an input terminal and a common terminal;
FIG. 14 is a schematic diagram of an inverted buck/boost converter, wherein the three reactive elements are connected in series between an output terminal and a common terminal;
FIG. 15 is a schematic diagram of an inverted buck/boost converter, wherein the three reactive elements are connected in series between an output terminal and a common terminal; and
FIG. 16 is a schematic diagram of an inverted buck/boost converter, wherein the three reactive elements are connected in series between an input terminal and a common terminal.
DETAILED DESCRIPTION
As can be seen from the appended drawings, all the arrangements shown comprise three reactive elements connected in series: a first induction coil 1, a capacitor 2 and a second induction coil 3. A switching power transistor 4 and a diode 5 are connected to the connection points 12 and 13 between the reactive elements 1, 2 and 3 so that the transistor 4 and the diode 5 are never simultaneously conducting, i.e. so that the diode 5 is conducting when the transistor 4 is non-conducting and that the diode 5 is non-conducting each time the transistor 4 becomes conducting.
The arrangement of FIG. 1 represents a buck converter with non-inverted voltage and continuous input and output currents. In this arrangement, the reactive elements 1, 2 and 3 are connected in series between the input terminal 10 and the output terminal 20. The diode 5 is connected between the common terminal 15 and the connection point 12. A second capacitor 7 and the transistor 4 are connected in series between the common terminal 15 and the connection point 13. A third induction coil 6 is connected on the one hand to the connection point 12 and on the other hand to the connection point 16 between the capacitor 7 and the drain electrode of transistor 4.
In the arrangement of FIG. 2, the reactive elements 1, 2 and 3 are connected in series between the input terminal 10 and the common terminal 15. The transistor 4 is connected between the connection point 12 and the output terminal 20. The diode 5 is connected in series with a second capacitor 7 between the connection point 13 and the output terminal 20. A third induction coil 6 is connected on the one hand to the connection point 12 and on the other hand to the connection point 17 between the diode 5 and the capacitor 7. This arrangement is also used as a buck converter with non-inverted voltage.
In the arrangement of FIG. 3 the reactive elements 1, 2 and 3 are connected in series between the input terminal 10 and the output terminal 20. The transistor 4 is connected between the connection point 13 and the common terminal 15. The diode 5 is connected in series with a capacitor 7 between the connection point 12 and the common terminal 15. A third induction coil 6 is connected on the one hand to the connection point 19 between the diode 5 and the capacitor 7 and on the other hand to the connection point 13. This arrangement is used as a non-inverted boost converter with continuous input and output currents.
The arrangement of FIG. 4 is also used as a non-inverted boost converter. The reactive elements 1, 2 and 3 are connected in series between the common terminal 15 and the output terminal 20. The diode 5 is connected between the input terminal 10 and the connection point 13. A second capacitor 7 is connected in series with the transistor 4 between the input terminal 10 and the connection point 12. A third induction coil 6 is connected between the connection point 13 and the connection point 16 between the second capacitor 7 and the transistor 4.
The arrangement of FIG. 5 is used as a non-inverted buck/boost converter with continuous input and output currents. In this arrangement, the reactive elements 1, 2 and 3 are connected between the input terminal 10 and the common terminal 15. The transistor 4 is connected in series with a second capacitor 7 between the connection point 12 and a terminal 18 connected to the output terminal 20. The diode 5 is connected between the connection point 13 and said terminal 18. A third induction coil 6 is connected on the one hand to the connection point 16 between the drain electrode of transistor 4 and the capacitor 7 and on the other hand to the connection point 13.
In the arrangement of FIG. 6, the reactive elements 1, 2 and 3 are connected in series between the common terminal 15 and the output 20. The transistor 4 is connected between the connection point 12 and a terminal 19 connected to the input terminal 10. The second capacitor 7 is connected in series with the diode 5 between the terminal 19 and the connection point 13. A third induction coil 6 is connected on the one hand to the connection point 17 between the capacitor 7 and the diode 5 and on the other hand to the connection point 12. This arrangement is used as a non-inverted buck/boost converter with continuous input and output currents.
The FIGS. 7 and 8 show two variations to the arrangement of FIGS. 5 and 6 respectively, in which galvanic isolation is provided between the input and the output of the quadripole. More specifically, the arrangement of FIG. 7 is similar to the one of FIG. 5, except that the induction coils 3 and 6 are comprised of two transformers. The arrangement of FIG. 8 is similar to the one of FIG. 6, except that the induction coils 1 and 6 are comprised of two transformers.
In the arrangement of FIG. 9, the reactive elements 1, 2 and 3 are connected in series between the input terminal 10 and the output terminal 20. The transistor 4 is connected in series with a second capacitor 7 between the connection point 12 and the common terminal 15. The diode 5 is connected between the connection point 13 and the common terminal 15. A third induction coil 6 is connected on the one hand to the common point 16 between the drain electrode of transistor 4 and the capacitor 7 and on the other hand to the connection point 13. This arrangement is used as an inverted buck/boost converter with continuous input and output currents.
The FIGS. 10 to 16 also show arrangements for inverted buck/boost converters. In the arrangement of FIG. 10, the reactive elements 1, 2 and 3 are connected in series between the input terminal 10 and the output terminal 20. A second capacitor 7 is connected in series with the transistor 4 between the common terminal 15 and the connection point 12. The diode 5 is connected between the common terminal 15 and the connection point 13. A third induction coil 6 is connected on the one hand to the connection point 16 between the transistor 4 and the capacitor 7 and on the other hand to the connection point 13.
In the arrangement of FIG. 11, the reactive elements 1, 2 and 3 are connected in series between the input terminal 10 and the output terminal 20. The transistor 4 is connected between the common terminal 15 and the connection point 12. A second capacitor 7 and the diode 5 are connected in series between the common terminal 15 and the connection point 13. A third induction coil 6 is connected on the one hand to the connection point 12 and on the other hand to the connection point 17 between the capacitor 7 and the diode 5.
The arrangement of FIG. 12 includes three reactive elements 1, 2 and 3 connected in series between the input terminal 10 and the output terminal 20. The transistor 4 is connected between the connection point 12 and the common terminal 15. The diode 5 is connected in series with a second capacitor 7 between the connection point 13 and the common terminal 15. A third induction coil 6 is connected between the connection point 12 and the connection point 17 between the diode 5 and the capacitor 7.
In the arrangement of FIG. 13, the three reactive elements 1, 2 and 3 are connected in series between the input terminal 10 and the common terminal 15. The diode 5 is connected between the output terminal 20 and the connection point 12. A second capacitor 7 is connected in series with the transistor 4 between the output terminal 20 and the connection point 13. A third induction coil 6 is connected between the connection point 12 on one side and the connection point 16 between the capacitor 7 and the transistor 4 on the other side.
The arrangement of FIG. 14 includes three reactive elements 1, 2 and 3 connected in series between the output terminal 20 and the common terminal 15. The transistor 4 is connected between the input terminal 10 and the connection point 12. A second capacitor 7 is connected in series with the diode 5 between the input terminal 10 and the connection point 13. A third induction coil 6 is connected between the connection point 12 on one side and the connection point 17 between the diode 5 and the capacitor 7 on the other side.
In the arrangement of FIG. 15, the three reactive elements 1, 2 and 3 are connected in series between the output terminal 20 and the common terminal 15. The transistor 4 is connected between the input terminal 10 and the connection point 12. The diode 5 and a second capacitor 7 are connected in series between the connection point 13 and the input terminal 10. A third induction coil 6 is connected between the connection point 12 and the connection point 17 between the diode 5 and the capacitor 7.
FIG. 16 shows an arrangement in which the three reactive elements 1, 2 and 3 are connected in series between the input terminal 10 and the common terminal 15. The diode 5 is connected between the connection point 12 and the output terminal 20. The transistor 4 is connected in series with a second capacitor 7 between the connection point 13 and the output terminal 20. A third induction coil 6 is connected between the connection point 12 and the connection point 16 between the transistor 4 and the capacitor 7.
Each of the arrangements described in the foregoing can be adjusted in an optimum way for a particular application by properly sizing the reactive elements so as to reduce the output current ripple and the output voltage ripple to a minimum. Further, all the topologies as disclosed have bi-directional properties, i.e. each of terminal pairs of the quadripole which a converter is comprised of, can be used either as an input port or as an output port as well. | An electric converter comprising at least three reactive elements (1, 2, 3) connected in series, and a switching device comprising a switching transistor (4) and a diode (5), the switching transistor operating at a high frequency so that it becomes conductive for a fraction of each period of said frequency. The transistor (4) and the diode (5) are connected to the connection points (12, 13) between the reactive elements (1, 2, 3) so that the diode (5) is conductive only when the transistor (4) is non-conductive and so that it is non-conductive each time the transistor (4) becomes conductive. This device is used to control the electric current from a DC power supply to a load. | 7 |
FIELD OF THE INVENTION
The present invention relates to a Novel mutant strain of Clostridium acetobutylicum and a fermentation process for producing butanol using that mutant strain.
BACKGROUND OF THE INVENTION
Diminishing petroleum resources have made the search for alternative fuel and chemical feedstock sources increasingly important. Butanol, in addition to its many uses as a chemical feedstock, is among the alternatives. The acetone/butanol/ethanol (ABE) fermentation, therefore, has received considerable attention in recent years as a prospective process for production of commodity chemicals from biomass. 3 ,6
ABE fermentations are biphasic. During the first (acidogenic) phase logarithmic growth is accompanied by acetic and butyric acid production which also causes a drop in pH. In the second (solventogenic) phase growth ceases and the solvents (ABE) are produced concomitant with consumption of already produced acids and further consumption of the carbohydrates. Hydrogen and carbon dioxide are produced throughout the fermentation.
Traditionally, the commercial ABE fermentation was conducted only in a batch mode due to culture instability and spore-forming nature of the organism. Several solvent-yielding fermentation processes using batch or continuous cultures 2 ,4,7, chemostats with cell recycling 1 or immobilized cell systems 5 have been described. These processes yield butanol, acetone and ethanol in a ratio of 6:3:1 11 . Mixed solvent yields of 29-33% of fermentable carbohydrate have been reported in the literature. 12 A total solvent concentration of about 16-20 g/L and a butanol concentration of 10-12 g/L is generally the limit due to toxicity of the butanol produced. 10
When C. acetobutylicum is grown in a chemostat, different proportions of acids and solvents are produced depending on the dilution rate and the medium composition. In batch fermentation with the spore-forming strain, selectivity and stability is affected by high carbohydrate concentrations and for this reason high carbohydrate containing fermentations have not been practiced.
For a fermentation process to produce butanol and solvents from carbohydrates to be economical, the solvent yield, concentrations and productivity should be as high as possible.
To make the ABE fermentation economically viable, a number of problems must be addressed. The first of these relates to product toxicity. C. acetobutylicum is intolerant to high concentrations of butanol, 8 with, as little as 1.3% inhibiting growth and fermentation. However, it is important to note that an increase in the butanol concentration from 1.2% to 2% in the fermentation broth would halve the energy consumption for distillation. 9 The second problem relates to the fermentation of a high level of initial substrate concentration. C. acetobutylicum ATCC 4259, will not grow and ferment an initial substrate level higher than 78-80 g/L. Thus, achievable levels of butanol and solvents are limited. An equally important problem with a C. acetobutylicum culture is its sporulation which as mentioned earlier is associated with inefficiency of the culture in terms of solvent production. Another problem relates to low productivity. The productivity of the ABE process could be increased by enhancing the fermentation rate of the culture. The organism used for fermentation should have high butyrate uptake activity so that the intermediary compound ends up in butanol and no residual butyrate is left in the fermentation broth. Finally, the instability of the conventional ABE fermentation process is another problem.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to disclose on a mutant microorganism for use in an ABE fermentation. of C. acetobutylicum, ATCC (55025) is prepared by treating the parent strain C. acetobutylicum (ATCC 4259) with ethyl methane sulfonate. The mutant is asporogenic, has a high butyrate uptake rate, a good tolerance to increased initial substrate levels and butanol produced, and that it produces high levels of solvents in high yield when used in an ABE fermentation process. The mutant has been deposited with American Type Culture Collection and assigned ATCC 55025.
We also have discovered that high butanol and solvent concentrations can be obtained by using this mutant in an improved fermentation process which basically comprises an initial continuous fermentation stage or stages followed by batch fermentation(s) to completion. The improved process using the mutant results in butanol and solvent yields of between 22 to 38%, and permits an increase in initial substrate concentration which helps achieve increased levels of butanol and total solvents. The mutant strain also has in an unexpectedly high uptake of butyrate which results in high concentration of butanol in the fermentation broth with low residual butyrate. The increased concentration facilitates recovery of the butanol, thereby reducing the energy and costs of distillation.
Other advantages and objects of the invention will be apparent to those skilled in the art from the description of the asporogenic strain, process and the examples.
DESCRIPTION OF PREFERRED EMBODIMENT
In the preferred practice of the invention, a mutant strain C. acetobutylicum ATCC 55025, is prepared by growing a culture of C. acetobutylicum ATCC 4259 at about pH 4.9 to about 5.6 at about 33 to about 38° C for about 9 to about 18 hours, treating the cells with aqueous ethyl methane sulfonate, growing the treated cells anaerobically and selecting and isolating the asporogenic cells. The asporogenic strain has an increased tolerance to the high initial substrate levels, butanol and solvent levels, and has high butyrate uptake rate.
In the preferred method of the invention, the mutant is employed in a process configuration which comprises first a three-stage continuous fermentation at about 36° C followed by batch fermentation(s) of the fermentation broth from second or subsequent stages of continuous fermentation.
The practice of the invention is illustrated by the examples in which the following materials and methods were used:
Organisms
Clostridium acetobutylicum parent strain (ATCC 4259) was obtained from American Type Culture Collection, Rockville, Md. while the mutant strain E604 of C. acetobutylicum (ATCC 55025) was prepared at Michigan Biotechnology Institute, Lansing, Mich.
Growth and Fermentation Media
The media for growth unless otherwise stated contained starch hydrolysate (Maltrin M-100) 60 g/L, commercially available corn steep liquor, 10 g/L (d.b.), and corn gluten (Prarie Gold), 10 g/L d.s.; pH was adjusted to 5.4 with NaOH. Fifty ml of medium reduced with 0.025% cysteine-sulfide was inoculated from a fresh stock culture and incubated at 36±1° C. anaerobically for 12 hours. Agar medium was made by supplementing the growth medium with Bacto-agar (Difco, Ann Arbor, Mich.) at 2.0%.
Mutant colonies were picked up in tubes containing CAB medium which contained (g/L): glucose, 30; yeast extract, 4; tryptone, 1; KH 2 PO 4 , 0.7; K 2 HPO 4 . DL-asparagine, 0.5; MgSO 4 .7H 2 O. 0.1; MnSO 4 .H 2 O, 1.0; FeSO 4 .7H 2 O, 0.015; NaCl,0.1; and resazurin, (0.2%), 1 ml. The pH was adjusted to 5.4 and after autoclaving the media tubes were reduced with cysteine-sulfide (2.5%) @ 0.1 ml/10 ml.
Media for fermentation contained:
______________________________________Starch hydrolysate 50-60 g/L 80 g/L 100 g/L(Maltodextrin M-100)Corn Steep Liquor, CSL 7.5 g/L 10 g/L 11.3 g/L(d.b.)Gluten (d.b.) 7.5 g/L 10 g/L 11.3 g/LFeSO.sub.4 5 ppm 5 ppm 5 ppm______________________________________
The pH of the medium was adjusted to 5.2 with concentrated NaOH before autoclaving. The gluten and CSL were autoclaved separately and added later. All the media were boiled and gassed with N 2 prior to fermentation.
Butyrate Uptake Studies
Butyrate uptake experiments were carried out in 58 ml serum vials (Wheaton, Millville, N.J.). These vials were made anaerobic by repeated evacuation and flushing with N2 gas. Twenty ml effluent from stage 2 fermentor was anaerobically transferred to the serum vial, to which was then added a desired concentration of sodium butyrate solution before incubation. Samples were withdrawn at different time intervals. Controls without addition of butyrate were also kept.
Quantitative Analysis of Substrates and Products
Carbohydrate substrate was analyzed as dextrose equivalent using YSI analyzer after treatment with glucoamylase and α-amylase. Soluble fermentation products were analyzed using GC fitted with chromosorb column with injector, column and detector temperature being 230, 170 and 250° C., respectively.
EXAMPLE 1
Mutagenesis
The parent strain of C. acetobutylicum (ATCC 4259) was grown in the media containing 60 g/L maltrin (M-100), 10 g/L corn gluten, and 10 g/L corn steep liquor (d.b.) pH was adjusted to 5.3 and after autoclaving at 121° C. for 25 min cysteine-sulfide was added at 0.20 ml/10 ml. When the culture was in active state after 12 h growth at 37° C., 5 ml of it was treated with 0.2 ml of 1:1 diluted aqueous ethyl methane sulfonate (EMS) solution. A drop of titanium (Ti-NTA) solution was added to keep the reduced conditions in the tube. The culture medium inoculated with the EMS mutagen was incubated at 37° C. for 60 min. At the end of incubation, the cells were pelleted by centrifugation at 3000×g for 10 min. The supernatant containing EMS was removed by syringe and the cells were washed twice with the reduced media. Finally, the pellet was resuspended in 9 ml of reduced media and the culture was incubated at 37° C. for 24 h. At the end of incubation, the cells were centrifuged at 3000×g for 10 min and the pellet was resuspended in the fresh media. After another 24 h growth at 37° C., a tube containing fresh media was inoculated with this culture using a 5% inoculum. After 12 h of growth, the culture was plated on the same media containing 2 % agar in an anaerobic glove box. The plates were incubated anaerobically under a blanket of nitrogen gas. After 4 days of growth at 37° C. the colonies were picked by sterile toothpicks and placed into tubes containing CAB media. After growth, the cells were observed for sporulation and the asporogenic cultures were selected and isolated. The mutant ATCC 55025 was further streaked onto agar plates of CAB media to obtain a pure culture.
EXAMPLE 2
Butanol Tolerance
The ability of the parent strain and the mutant to tolerate and grow in presence of various levels of end product butanol was examined in 58 ml serum vials under batch conditions. Various levels of butanol ranging from 1-11 g/L was added to the medium in vials (initial carbohydrate, 10 g/L) before inoculation and the vials were incubated at 36° C. After 35 hours of incubation, growth was examined by measuring absorbance at 660 nm and by analyzing production of butyrate in the culture broth.
TABLE 1______________________________________Butanol tolerance of parent strain (ATCC4259) and mutant strain (ATCC 55025) of C. acetobutylicumATCC 4259 ATCC 55025Initial Butyrate ButyrateButanol Growth Production Growth Productiong/L A.sub.660 nm g/L A.sub.660 nm g/L______________________________________0 0.8 1.3 1.1 1.12.75 0.6 1.0 1.1 1.15.2 0.0 0.1 1.1 1.16.9 0.0 0.1 1.0 1.08.9 0.0 0.1 0.9 0.711.4 0.0 0.0 0.6 0.5______________________________________
Results presented in Table 1 clearly indicate that growth initiation of the parent strain was inhibited at initial butanol level above 5.0 g/L. However, the growth initiation of the mutant strain was not affected up to an initial butanol level of about 11.4 g/L. Even at such high concentrations of butanol only the growth rate was affected but not the ability of the mutant to initiate the growth and ferment the substrate. These results indicate that the mutant strain has more tolerance to the end product butanol than the parent strain.
EXAMPLE 3
Batch Fermentation
The comparative results obtained when batch fermentations were run using the parent and mutant strain of C. acetobutylicum are shown in Table 2. In the batch fermentations the initial substrate concentration was approximately 60 g/L, the pH was controlled between 5.0 and 5.2, the fermentation temperature was 36° C. and agitation was set at 200 rpm. The fermentations were run in a 2-liter fermentor with 1-liter working volumes.
TABLE 2______________________________________Comparison of parent and mutant strains of C.acetobutylicum (Batch fermentation) Substrate Actual Butanol Consumption Final Pro- Butanol Rate Butanol ductivity YieldStrain g/L hr g/L g/L hr (wt %)______________________________________Parent 0.79 10.6 0.17 21.3(ATCC 4259)Mutant 1.45 13.0 0.33 22.7(ATCC 55025)______________________________________
The fermentation with mutant strain ATCC 55025 was completed much earlier than parent strain. A substrate consumption rate of 1.45 g/L hr was obtained for mutant strain which was nearly twice the rate of parent strain. Similarly, butanol productivity rates by mutant strain were also almost twice (0.33 vs 0.17 g/L hr) in comparison to parent strain. Actual final butanol concentration in the fermentation broth of the parent strain was 10.6 g/L while in that of mutant it was 13.0 g/L. Butanol yield by mutant was also higher than parent strain.
The results indicate that under the same batch fermentation conditions the mutant strain unexpectedly shows a very active fermentation in terms of increased substrate consumption and butanol productivity rates.
EXAMPLE 4
Continuous Fermentation
The mutant strain and the parent strain were also compared in the multistage continuous fermentation configuration in terms of butanol and total solvent concentrations and solvent productivity rates. The fermentation process equipment consisted of three continuous fermentors in series with respective dilution rates of 0.25, 0.135 and 0.135 h -1 for stage 1, stage 2 and stage 3. Stage 1 continuous fermentor was a New Brunswick Multigen fermentor with 400 ml working volume. The pH was controlled at 5.1±1° C. with 4N NaOH at 200 rpm agitation. Stage 2 and 3 were Multigen fermentors with 1-liter working volumes. The temperatures in all the stages were maintained at 36° C. The pH was controlled only in the first stage. The fermentation in stage 2 and 3 were self-buffering and required no pH control. Agitation was set at 200 rpm.
The results presented in Table 3 represent the average of at least 4 observations after the steady-state. Only acids were produced in the stage 1 with no detectable production of butanol, acetone or ethanol. However, stage 2 data show that butanol and total solvent concentrations produced by mutant were higher by 41-45% and this was repeated in stage 3. The solvent productivity rates in stage 2 (0.90 vs 0.64 g/L hr, mutant vs parent strain) as well as stage 3 (0.96 vs 0.71 g/L hr, mutant vs parent strain) also show that mutant strain has better fermentation rate. The results indicate that the mutant strain also performs better in a multistage continuous fermentation system when compared with parent strain in terms of butanol and total solvents concentrations and solvent productivity rates.
TABLE 3______________________________________Comparative Performance of Parent (ATCC 4259) and Mutant(ATCC 55025) Strain of C. acetobutylicum (Multistage,Continuous Fermentation of Steady-State) Butanol Solvent Solvent Production Production Productivity (g/L) (g/L) (g/L hr)Fermentation ATCC ATCC ATCC ATCC ATCC ATCCStage 4259 55025 4259 55025 4259 55025______________________________________1 0 0 0 0 0 02 4.7 6.8 7.3 10.3 0.63 0.903 8.7 11.6 13.3 18.0 0.70 0.95 Stage 1 Stage 2 Stage 3Dilution Rate 0.25 0.135 0.135Rate (.sup.-1)pH: 5.1 ± 1° C. Uncontrolled UncontrolledTemperature 36 36 36(°C.)______________________________________
EXAMPLE 5
Butyrate Uptake
The butyrate uptake rates of parent and mutant strain were compared in 158 ml serum vials by supplementing additional butyrate (approximately 4.7 g/L) to stage two effluent of a three stage continuous system and incubating at 30° C. After incubation for 24 h, the culture broth was analyzed for butyrate, butanol, acetone and ethanol.
The results presented in Table 4 indicate that the mutant has about 27% higher butyrate uptake rate (0.33 vs 0.26 g/L hr) in comparison to parent strain. The butyrate conversion efficiency for the mutant was also higher (97.5%) as compared to parent strain (86.6%). The data indicate that mutant strain has a much better butyrate uptake rate and butyrate conversion efficiency than the parent strain. Also the repetitive fermentation runs with the mutant showed only negligible residual butyrate level (about 1/10th or less in comparison to parent strain) in the fermentation broth. This also indicates that butyrate uptake rate of the mutant strain was much higher than the parent strain.
TABLE 4______________________________________Comparison of Parent and Mutant Strains of C. acetobutylicumfor Butyrate Uptake Using Stage Two Broth in Three StageContinuous Process at Steady-State Parent Strain Mutant StrainParameter ATCC 4259 ATCC 55025______________________________________Butanol (g/L) 13.9 17.6Total Solvents (g/L) 18.8 25.3Solvent Production 0.53 0.71Rate (g/L hr)Butyrate Uptake 0.26 0.33Rate (g/L hr)*Butyrate Conversion 86.6 97.5Efficiency (%)**______________________________________ *Butyrate was added at the concentration of 4.7 ± 0.6 g/L in the stage two broth contained in a vial and incubated for 24 hours at 30° C. **Calculations based on butyrate conversion in 24 hours in vials
EXAMPLE 6
Substrate Tolerance
The parent and mutant strains were compared in relation to their ability to initiate growth at, and ferment, high initial substrate concentration. The comparison was made in the multistage continuous fermentation process followed by batch fermentation of second and third stage fermentation broth to completion. The initial substrate concentration was 97 g/L.
The parent strain was not able to initiate growth and ferment substrate when the substrate concentrations was 97 g/L. In contrast, the mutant strain initiated growth and fermented such a high substrate concentration. The results obtained are presented in Tables 5 and 6.
At steady-state, stage three showed 3.8 g/L acids and 16.2 g/L total solvents (Table 5) in a residence time of 19 hours during which a total of about 58 g/L substrate was consumed. The results of batch fermentation of stage three broth presented in Table 6 show that a very high concentration of butanol (approximately 20 g/L) and total solvents (about 30 g/L) can be achieved.
TABLE 5__________________________________________________________________________Three Stage Continuous Fermentation by C.acetobutylicum mutant at Elevated Substrate Level Steady-State). Total Carbohydrates Fermentation Products (g/L) as glucose Acetic ButyricStage g/L Acid Acid Acetone Butanol Ethanol__________________________________________________________________________Feed 97.0 -- -- -- -- --Stage One 85.2 1.1 1.9 -- 0.1 --Stage Two 57.0 1.6 2.5 2.3 5.9 0.6Stage Three 39.0 1.7 2.1 4.6 10.8 0.8__________________________________________________________________________
TABLE 6______________________________________Batch Fermentation of Stage Two and ThreeBroth of Process with Elevated Substrate Level for 48 h. Stage Two Stage Three______________________________________Products (g/L)Acetic Acid 1.8 1.7Butyric Acid 0.2 0.1Acetone 6.9 8.4Butanol 19.6 20.2Ethanol 1.4 1.5Total Solvents 27.9 30.1Substrate (g/L) 12.2 10.0Residual CarbohydrateSubstrate (g/L)______________________________________
These results show that the mutant strain is better than the parent strain in tolerance to high substrate concentrations. The mutant strain under the multistage continuous fermentation coupled to batch fermentation and high substrate concentrations has produced butanol (20 g/L) and total solvents (30 g/L) in very high concentrations.
EXAMPLE 7
Comparison of Parent and Mutant Strains
Side by side comparison of parent and mutant strain under identical conditions, i.e. vials, batch fermentations, continuous fermentations, multistage continuous - batch fermentations, high substrate concentration, has shown that the asporogenic mutant strain is an improved and better strain than the parent strain. The key results obtained under examples 1 to 6 are summarized in Table 7.
TABLE 7______________________________________Summary comparison of parent and mutantstrain of C. acetobutylicum Parent Strain Mutant StrainParameters (ATCC 4259) (ATCC 55025)______________________________________Sporulation + -Maximum Substrate 78.5 97.0Tolerance (g/L)Maximum Butanol 16.7 20.2Production (g/L)Maximum Total 25.3 30.1Solvent Production (g/L)Butyrate Uptake Rate 0.26 0.33(g/L hr)Butyrate Conversion Efficiency 86.6 97.5(%)______________________________________
The results show that the mutant strain of C. acetobutylicum ATCC 55025 is much better than parent strain; it can tolerate a very high level of substrate (greater than 95 g/L), butanol, and total solvent concentrations; it can produce a high concentration of butanol (greater than 20 g/L) thus cost of recovery could be reduced; it can produce a high concentration of solvents (greater than 30 g/L); it has a higher rate of butyrate uptake; it has a high substrate consumption rate; it has shown high solvent productivity; and it is stable in batch as well as multistage continuous fermentation processes.
REFERENCES
1. Afschar, A. S., H. Biebl, K. Schaller, and K. Schugerl. 1985. Production of acetone and butanol by Clostridium acetobutylicum in continuous culture with cell recycle. Eur. J. Appl. Microbiol. Biotechnol. 22:394-398.
2. Bahl, H., W. Andersch, and G. Gottschalk. 1982. Continuous production of acetone and butanol by C. acetobutylicum in a two-stage phosphate limited chemostat. Eur. J. Appl. Microbiol. Biotechnol. 15:201-205.
3. Gibbs, D. F. 1983. The rise and fall (. . . and rise?) of acetone/butanol fermentations. Trends Biotechnol. 1:12-15.
4. Gottschal, J. C. and G. Morris. 1982. Continuous production of acetone and butanol by Clostridium acetobutylicum growing in turbidostat culture. Biotechnol. Lett. 4:477-482.
5. Haggstrom, L. and S. 0. Enfors. 1982. Continuous production of butanol with immobilized cells of Clostridium acetobutylicum. Appl. Biochem. Biotechnol. 7:35-37.
6. Jones, D. T. and D. R. Woods. 1986. Acetone-butanol fermentation revisited. Microbiol. Rev. 50:484-524.
7. Kim, B. H., P. Bellows, R. Datta and J. G. Zeikus. 1984. Control of carbon and electron flow in Clostridium acetobutylicum fermentation: utilization of carbon monoxide to inhibit hydrogen production and to enhance butanol yields. Appl. Environ. Microbiol. 48:764-770.
8. Linden, J. C. and A. R. Moreira. 1983. Anaerobic production of chemicals. In "Biological Basis for New Developments in Biotechnology", eds. A. Hollander, A. I. Laskin and P. Rogers, p. 377. Plenum Pub. Co., New York
9. Linden J. C., Moreira, A. R. and T. G. Lenz. 1986. Acetone and Butanol. In "Comprehensive Biotechnology" ed. M. Moo Young, vol. 3, The Practice of Biotechnology: Current Commodity Products, eds. H. W. Blanch, S. Drew and D. I. C. Wang, p. 915-931. Pergamon Press, Oxford, England.
10. Moreira, A. R., A. C. Ulmer and J. C. Linden. 1981. Butanol toxicity in the butylic fermentation. Biotechnology and Bioengineering Symposium. 11:567-579.
11. Prescott, S. C. and C. G. Dunn. 1959. The acetone
butanol fermentation, p. 250-284. In S. C. Prescott and C. G. Dunn (ed.), Industrial Microbiology, 3rd ed. McGraw Hill Book Co., New York.
12. Underkofler, L. A. and R. Hickey, Eds. Chemical Publishing Co., New York, 1954. Chap. 11, pp. 347-390. | A biologically pure asporogenic mutant of Clostridium acetobutylicum is produced by growing sporogenic C. acetobutylicum ATCC 4259 and treating the parent strain with ethane methane sulfonate. The mutant which as been designated C. acetobutylicum ATCC 55025 is useful in an improved ABE fermentation process, and produces high concentrations of butanol and total solvents. | 8 |
FIELD OF THE INVENTION
This invention relates to the use of enzymes for industrial processes, particularly, purification methods advantageous for the enhancement of enzyme activity and stability.
BACKGROUND OF THE INVENTION
The industrial use of enzymes is often limited by their high cost and rapid inactivation. Soluble enzymes are lost with the product at the conclusion of a process, and must be replenished. One area of technological development involves modification of proteins to enhance their activity and/or stability. Processes, such as those involving site-directed mutagenesis and the cultivation of wild forms of enzymes in extreme environments, i.e. extremophiles, have led to significant advances in enzyme technology involving the reduction in the cost per unit of enzyme activity.
Another means to improve the economic feasibility of enzymes for industrial processes is through enzyme immobilization onto a matrix, which may facilitate re-use of the enzyme. Immobilization research has focused upon means to enhance the transfer of enzymes onto the support, and upon means to ensure that the immobilized enzymes remain active. Inactivation of enzymes during catalytic turnover is, however, a key obstacle which may limit the economic feasibility of enzyme-mediated processes. Enzymes may be inactivated by extremes of temperature, pH, shear, and also by free radicals and other reactive species present in the reaction medium. Immobilization technology has the potential to reduce such enzyme inactivation, and, thus, extend the useful lifespan of the enzymes.
Activated carbon is a well-known absorbent and has been previously used for enzyme immobilization via absorption (A. S. Rani, M. L. M. Das, S. Satyanarayana, J. Mol. Catal. B. Enzymatic, 10, 471, 2000), or following derivatization or cross-linking. It is also frequently used for purification of water, beverages, and other process streams. Activated carbon has been used to remove phenolics and phenolic exudates from cultures of A. Canadensis , to facilitate cell growth (G. M. Roy, Activated Carbon Applications in the Food and Pharmaceutical Industries, Technomic Publishing Co., Lancaster, Pa., 1995). It has also been used for removal of amino acids from protein hydrolysate solutions (Roy, ibid), and for removal of phenolics from soy protein extracts. Activated carbon has also been used to remove chill-sensitive proteins from beer (J. W. Hassler, Purification With Activated Carbon, Chemical Publishing Co., New York, 1974). U.S. Pat. No. 6,582,606 discusses the benefits of activated carbon for microfiltration, in order to reduce fouling of ultrafiltration membranes and enhance separation. However, the prior art is silent as to the effect of activated carbon in enhancing the activity of enzyme solutions.
SUMMARY OF THE INVENTION
It is the object of the present invention to produce an enzyme form of enhanced activity for use in industrial processes which improved enzyme form is produced by reagent purification.
Accordingly, in one aspect the invention provides a method of enhancing the intrinsic activity of an enzyme from a raw enzyme solution, said method comprising treating said enzyme solution with an effective amount of a purifying agent for a sufficient period of time, preferably, activated carbon to effect said enhancement and provide an enzyme solution of enhanced activity.
The raw enzyme solution comprises one or more proteins resulting from a fermentation process.
Thus, the invention, as hereinabove defined, results from the surprising discovery that purification of a raw enzyme solution using the purifying agent, most preferably, activated carbon, can dramatically enhance the activity of the enzyme solution.
By the term “raw enzyme solution” in this specification is meant a commercial grade formulation, produced by fermentation from any one of a variety of bacterial and microbial sources. In the case of an extracellular enzyme, the crude enzyme extract is obtained by, e.g., filtration or centrifugation of the fermentation broth, thus isolating the enzyme from protein debris. If the enzyme is produced intracellularly, the cells are lysed prior to filtration/centrifugation. The crude enzyme extract may also be subjected to membrane separation, ion exchange, or ultrafiltration to produce a partially purified, concentrated enzyme extract rich in the desired enzyme, and relatively devoid of other competing/contaminating enzymes and/or cells. The enzyme solution may also include residual components from the fermentation medium, protease inhibitors, and stabilizing agents.
We have found that the specific enzyme activities, particularly of commercial enzyme formulations are greatly enhanced after purification with, for example, activated carbon.
We have found that the purified enzymes exhibit a significant change in UV-VIS and Far UV (CD) spectra, exhibit substantially different properties as demonstrated by gel electrophoresis and by chromatographic separation, and have increased enzyme activity. Without being bound by theory, we believe that this positive effect of activated carbon purification is a result of improved enzyme substrate interactions, interconversion between inactive and active forms of the protein (enzyme), or the removal of inhibitors. Commercial enzyme preparations, formulations and the like, are, generally, colloid solutions that may have a significant amount of dispersed solids, such as, cell debris that may adsorb onto the enzyme and shield the enzyme active centre, and, thus, limit access to bulky substrates, such as starches. Accordingly, enzyme active centre shielding by dispersed solids may, thus, decrease the enzyme specific activity.
In a further aspect, the invention provides a method as hereinabove defined wherein said enzyme solution of enhanced activity shows in the CD spectral range of 205-230 nm; a relative absorbance intensity lower than said raw enzyme solution.
Preferably, the ratio of A to B the ratio of A′ to B′, wherein A is the amount of enzyme in the enzyme solution of enhanced activity; B is the a mount of said organic entities A′ is the amount of enzyme and B′ the amount of said organic entities in said raw enzyme solution.
By the term “raw enzyme in connection with its weight” as used in this specification and claims is meant the volume of the raw enzyme solution x the density of the raw enzyme solution.
The weight ratio of raw enzyme to purifying agent is dependent on the enzyme and purifying agent. Preferably, the ratio is not greater than 50:1, more preferably, not greater than 25:1, and still more preferably not greater than 15:1. A preferred ratio for use with activated carbon as the purifying agent provides 11 g raw enzyme purified with 0.75 g activated carbon.
Accordingly, the invention provides in a preferred aspect, a method as hereinabove defined wherein said ratio is not greater than 50, preferably, the ratio is not greater than 25, and more preferably, not greater than 15.
Typical contact, i.e. residue time, of the raw enzyme with the purifying agent may be selected by the skilled person, but could be as short as less than 15 minutes, preferably 30 minutes, and more preferably at least 1-2 hours, depending on the enzyme and the purifying agent.
Preferably, the enzyme is selected from the group consisting of amylase, glucoamylase, cellulase, xylanase and any other group 3 hydrolase.
The resultant enzyme solution of enhanced activity may be used in admixture with the activated carbon, in its intended subsequent industrial process, such as, the hydrolysis of corn starch, if desired.
Most preferably, the activated carbon is removed, preferably, by filtration or centrifugation, prior to subsequent use of the enhanced activity formulation, which filtration method comprising passing said enzyme solution through a column containing an effective amount of said purifying agent.
We have discovered that the raw enzyme solution obtained as a product of a commercial, fermentation-derived product is preferably diluted with water prior to or at the time of admixture, with the purifying agent by a factor of at least three, and more preferably by about 5-10 times, in the process according to the invention. The raw enzyme solution is diluted with a desired amount of water or aqueous buffer solution for ease of mixing and separation of the activated carbon while, most surprisingly, at least maintaining its original level of enzymatic activity. Thus, the process according to the invention comprising the dilution of the raw enzyme solution provides a more efficacious use of the enzyme.
In a further aspect, the invention provides an enzyme aqueous formulation of enhanced activity when made by a process as hereinabove defined when suitably diluted with water.
In a further aspect, the invention provides a method of treating a substrate susceptible to enzymatic reaction with an enzyme, said method comprising treating said substrate with an enzyme formulation of enhanced activity as hereinabove defined.
The invention is of particular value in the treatment of polysaccharide products such as, for example, starch from, for example, wheat, potatoes and rice, with alpha-amylase, glucoamylase, cellulase, xylanase, glucose isomerase, or any other group 3 hydrolase.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be better understood, preferred embodiments will now be described by way of example only, wherein
FIG. 1 is a schematic process diagram illustrating a process according to the invention;
FIG. 2 represents spectral scans of each of (a) raw enzyme, (b) diluted raw enzyme; and (c) purified enzyme;
FIG. 3 represents Far UV circular dichroism (CD) spectral scans of each of (a) raw enzyme, and (b) purified enzyme for various commercial amylases and a purified amylase according to the invention;
FIG. 4 compares the characteristics of the purified enzyme with those of various commercial raw alpha amylases, as determined by polyacrylamide gel electrophoresis;
FIG. 5 represents the exhibits heat-sensitive quaternary structure of raw amylase (Allzyme); and
FIG. 6A and FIG. 6B represent the catalytic characteristics of the heavy and light species of raw and purified amylase towards soluble starch, at 25° C. as determined by a standard calorimetric iodine assay.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The following examples illustrate the method according to the invention.
EXAMPLE 1
Purification of Alpha Amylase with Activated Carbon
A purified enzyme solution was prepared as shown generally as 10 in FIG. 1 .
A diluted raw enzyme solution ( 12 ), comprising 60 mL raw amylase (Allzyme®, amylase from Alltech) and 270 mL of 0.05M phosphate buffer (pH 6), was prepared and mixed with 24 g of activated carbon ( 14 ) for 3 h with magnetic stirring at 300 rpm in a vessel ( 16 ). The purified enzyme ( 18 ) was separated from the activated carbon ( 20 ) by filtration. Assays of the raw enzyme solution, before dilution ( 12 ) and the purified enzyme solution ( 18 ) were conducted. The activity of the amylase solution ( 19 ) before dilution to produce solution ( 12 ) was 2035 U/mL, whereas the activity of the purified enzyme ( 18 ) was 2010 U/mL, notwithstanding that, due to dilution, the purified preparation contained only about 18 mL of amylase per 100 mL of solution ( 18 ). Thus, the activity of the purified enzyme ( 18 ), expressed per mL of raw amylase, would be about 11000 U/mL, or about 5.4 times the activity of the original amylase formulation ( 12 ). The activity of the diluted enzyme before purification ( 12 ) was statistically equivalent to that of the raw enzyme ( 19 ), when expressed per mL of raw amylase in the solution.
EXAMPLE 2
Purification of Alpha Amylase with Activated Carbon
An alternative purified enzyme solution ( 18 ) was prepared according to FIG. 1 wherein a diluted raw enzyme solution ( 12 ), comprising 40 mL raw amylase (Spezyme® Fred amylase, from Genencor) and 360 mL of water was prepared and mixed with 8 g of activated carbon ( 14 ) for 12 h with magnetic stirring at 250 rpm in vessel ( 16 ). The purified enzyme ( 18 ) was separated from the activated carbon ( 20 ) by filtration. Assays of the raw enzyme solution before dilution ( 19 ) and the purified enzyme solution ( 18 ) were conducted. The activity of the amylase solution before dilution ( 19 ) was 4486 U/mL, whereas the activity of the purified enzyme ( 18 ) was 4170 U/mL, notwithstanding that, due to dilution, the purified formulation ( 18 ) contained only about 10 mL of raw amylase per 100 mL of solution. Thus, the activity of the purified enzyme ( 18 ), expressed per mL of raw amylase, would be about 41700 U/mL, or about 9.3 times the activity of the original amylase formulation ( 19 ).
EXAMPLE 3
Purification of Glucoamylase
5 mL of glucoamylase (Genencor) was blended with 45 mL of 0.05M citrate buffer (pH 4.0), added to 2 g of activated carbon and mixed for 12 h at 250 rpm. The purified enzyme was separated from the activated carbon by filtration. Assays of the raw enzyme solution before dilution ( 19 ) and the purified enzyme solution ( 18 ) were conducted. The activity of the raw enzyme solution was 980 U/mL, and the activity of the purified enzyme solution was 350 U/mL, notwithstanding that, due to dilution, the purified formulation ( 18 ) contained only about 5 mL of raw amylase per 50 mL of solution. Thus, the activity of the purified enzyme ( 18 ), expressed per mL of raw amylase, would be about 3500 U/mL, or about 3.6 times the activity of the original amylase formulation ( 19 ).
The aforesaid examples show that purification of these two commercial amylase formulations with activated carbon has led to a clear improvement in activity. As hereinbefore mentioned, this improvement in activity may be due to removal of inhibitors from the enzyme solution, or may be due to removal of dispersed solids, e.g., cell debris that may adsorb onto the enzyme and restrict access of substrates to the enzyme active site. The results show that notwithstanding the significant dilution of the commercial formulations, the purified enzyme solutions according to the present invention possess nearly the same activity as the raw commercial enzyme formulations.
Evidence that treatment with activated carbon has affected the pre-treated enzyme solution is provided through FIG. 2 and 3 , which show spectral scans of the raw, undiluted enzyme (Δ), the modified enzyme (□), and the raw enzyme diluted in water (▪). Spectra in FIG. 2 are normalized with respect to their maximum absorbance values, which are 14.5, 1.0, and 1.43 for the raw, purified, and diluted forms, respectively. Clearly, there is a significant spectral shift. Compared to the raw enzyme solution, FIG. 2 illustrates that the purified preparation exhibits enhanced absorbance in the range from 340 to 380 nm, and a reduction in the absorbance from about 390 to 410 nm. The spectrum for the water-diluted preparation is similar to the spectral profile for the purified enzyme preparation, but exhibits a broader peak from 350 to 360 nm and a depression in absorbance from 390 to 440 nm. Similarly, the CD spectra for various enzymes ( FIG. 3 ) show that there is a substantial difference between the purified enzyme (MK10) and other alpha amylases (ALZ, LQZ, SPEZ, and THZ, especially in the range from 205 and 230 nm, as:
A sensitive aspect of these curves is the differences in wavelength (x axis) as well as differences in ellipticity (y axis). A small shift along the x axis reflects a difference in protein structure. Furthermore, the overall shapes of the curves are indicative of structure. Changes in shape also indicate differences in secondary structure. The CD equipment used for these studies detected wavelength differences as low as 0.1 nm, and thus, a 1 nm shift in the location of the minimum of the spectrum is significant, and a 2 nm shift is most significant.
The MK10 samples (purified amylases) differ from their parents (raw amylases) in that their minima in ellipticity are shifted by at least 2 nm from the minima exhibited by their parents. In one case, the minimum is shifted to the left, and in the other case, it is shifted to the right. However, the 2 nm shift to the left, and in the other case, it is shifted to the right. However, the 2 nm shift is significant, and it represents a significant structural change.
The invention in one preferred form provides a purified enzyme in which the minimum ellipticity on the CD spectrum is shifted by at least 1 nm from its parent (raw) amylase, in the range of between 205 and 230 nm.
Several different shapes of the spectra are also observed. The “dual minima” at ˜208 and 222 nm shown by samples D, E, and F are characteristic of an α-helix structure. The purified samples (G and H) do not exhibit such dual minima; rather, they have a fairly sharp minimum that is consistent with a substantially different secondary structure. The process according to the invention leads to changes in secondary structure of the following types:
α-helix→β-sheet α-helix→uncoiled β-sheet→α-helix β-sheet→uncoiled uncoiled→β-sheet
Clearly, some of the other enzyme preparations are also relatively devoid of an α-helix structure, and, thus, although the purified enzymes are not unique in this way, however, a change in secondary structure, e.g. from a structure dominated by α-helices to one devoid of α-helices is significant.
When separated by denaturing polyacrylamide electrophoresis (in the presence of sodium dodecyl sulfate and after boiling, i.e., SDS-PAGE), both the native amylases and the purified form exhibit two distinct species between 47 and 86 kDa ( FIG. 4 ). 5 μg of total protein was heat-denatured in the presence of SDS and separated in a 12% Lammeli gel. The image intensity has been log-transformed to clarify the faint lighter species in the source products. The two products differ significantly in the proportion of the two species; namely, raw amylase is more highly populated by the apparently larger species relative to the purified form.
FIG. 4 :
Two ratios have been calculated, whereby a first ratio, R, is defined as “top:bottom”, and represents the relative quantities of the top and bottom bands. The second ratio is a “recovery ratio”, F, defined as “bottom:(top+bottom)”. A higher value of F and a lower value of R each indicated a greater proportion of the more active lower band.
The following table summarizes these values:
Lane
Description
R
F
1
Purified Allzyme
1.6
0.39
2
Allzyme
4.7
0.18
3
Thermozyme
6.1
0.14
4
Purified Thermozyme
2.1
0.33
Thus, in each case, the process according to the invention has demonstrably increased the proportion of the more active form of the enzyme in the system (comparing purified form 1 vs. raw form 2 and purified form 4 vs. raw form 3).
Without boiling prior to electrophoresis, the intensity of these two characteristic bands diminish in favour of higher-molecular weight species (above 118 kDa; FIG. 5 , lane 2), suggestive of oligomerization. The source enzyme forms SDS-resistant assemblies (Lane 2) which dissociate upon boiling (Lane 1). This structure is not maintained by intermolecular disulfide bonds as the presence of 25% 2-mercaptoethanol exerts no effect (data not shown). Fractions obtained from Sephadex G-100 chromatography performed under native conditions (Lanes 3 and 4) do not appear to interconvert. This proposal is supported by size exclusion chromatography: elution through a Sephadex G-100 column produces two fractions, the first appearing in the void volume (i.e., >100 kDa) and the other in subsequent fractionation volumes. SDS-PAGE analysis of the eluates reveals that the void-volume fraction corresponds to the heavier species on the gel and the other fraction corresponding to the lighter species. The relative amounts of the two fractions track the proportions found in the unfractionated product, i.e., raw amylase, which exhibits a greater fraction of the heavier species in SDS-PAGE, also elutes a larger fraction of its contents in the void volume. Moreover, the two species appear to be stable and do not interconvert even under native conditions ( FIG. 5 , Lanes 3 and 4).
The functional significance of the two species is demonstrated by kinetic assays of their catalytic activities on soluble starch hydrolysis. For raw amylase, the heavier void-volume fraction is catalytically inactive; all of the product's activity resides in the lighter fraction ( FIGS. 6A and 6B ). A similar observation is found with the purified enzyme. This dichotomy in activity is also indirectly observed in Sephadex chromatography. Kinetics of raw amylase (solid) and purified amylase's light fraction (hollow) from pH 3 to 8. B, 40 μg of heavy species of raw amylase, isolated in the void volume from Sephadex G-100 chromatography, caused no change in starch-iodine staining after 10 min., while 1.3 μg of the lighter species quantitatively cleared iodine staining in the same period at pH 5.
Comparison of the lighter fractions from the two products indicates that they share similar, but not identical, activities, in terms of affinity and turnover, towards soluble starch across a pH range of 3 to 8 at 25° C.; specifically, both display maximal turnover between pH 4 to 5.
In the aggregate, the greater per-unit mass activity found in the purified enzyme can be largely accounted for by a greater proportion of active enzyme and suggest that a significant fraction of enzyme in raw amylase is inactive. The purification/derivatization of raw amylase may result in the conversion of this reservoir of stable, inactive amylase to a catalytically active form.
Although this disclosure has described and illustrated certain preferred embodiments of the invention, it is to be understood that the invention is not restricted to those particular embodiments. Rather, the invention includes all embodiments which are functional or mechanical equivalents of the specific embodiments and features that have been described and illustrated. | A method of enhancing the intrinsic activity of an enzyme in a raw enzyme solution, the method comprising treating the raw enzyme solution with an effective amount of a purifying agent, most preferably, activated carbon, to effect the enhancement and provide an enzyme solution of enhanced activity. Preferred enzymes are amylase, glucoamylase, cellulase, xylanase, and all other group 3 hydrolases. | 2 |
SUMMARY OF THE INVENTION
The present invention relates generally to a two position, bistable, straight line motion actuator and more particularly to a fast acting actuator which utilizes high fluid pressure acting on a piston to perform fast transit times between the two positions. The invention utilizes control valves to gate high pressure fluid to the piston and permanent magnets to hold the control valves in their respective closed positions until the associated one of two coils is energized to neutralize the permanent magnet latching force and temporarily open the control valve allowing the high pressure fluid to move the piston from one position to the other.
This actuator finds particular utility in opening and closing the gas exchange, i.e., intake or exhaust, valves of an otherwise conventional internal combustion engine. Due to its fast acting trait, the valves may be moved between full open and full closed positions almost immediately rather than gradually as is characteristic of cam actuated valves. The actuator mechanism may find numerous other applications.
Internal combustion engine valves are almost universally of a poppet type which are spring loaded toward a valve-closed position and opened against that spring bias by a cam on a rotating cam shaft with the cam shaft being synchronized with the engine crankshaft to achieve opening and closing at fixed preferred times in the engine cycle. This fixed timing is a compromise between the timing best suited for high engine speed and the timing best suited to lower speeds or engine idling speed.
The prior art has recognized numerous advantages which might be achieved by replacing such cam actuated valve arrangements with other types of valve opening mechanism which could be controlled in their opening and closing as a function of engine speed as well as engine crankshaft angular position or other engine parameters.
For example, in U.S. patent application Ser. No. 226,418 entitled VEHICLE MANAGEMENT COMPUTER filed in the name of William E. Richeson on July 29, 1988 there is disclosed a computer control system which receives a plurality of engine operation sensor inputs and in turn controls a plurality of engine operating parameters including ignition timing and the time in each cycle of the opening and closing of the intake and exhaust valves among others. This application teaches numerous operating modes or cycles in addition to the conventional four-stroke cycle.
U.S. Pat. No. 4,009,695 discloses hydraulically actuated valves in turn controlled by spool valves which are themselves controlled by a dashboard computer which monitors a number of engine operating parameters. This patent references many advantages which could be achieved by such independent valve control, but is not, due to its relatively slow acting hydraulic nature, capable of achieving these advantages. The patented arrangement attempts to control the valves on a real time basis so that the overall system is one with feedback and subject to the associated oscillatory behavior.
U.S. Pat. No. 4,700,684 suggests that if freely adjustable opening and closing times for inlet and exhaust valves is available, then unthrottled load control is achievable by controlling exhaust gas retention within the cylinders.
Substitutes for or improvements on conventional cam actuated valves have long been a goal. In the Richeson U.S. Pat. No. 4,794,890 entitled ELECTROMAGNETIC VALVE ACTUATOR, there is disclosed a valve actuator which has permanent magnet latching at the open and closed positions. Electromagnetic repulsion may be employed to cause the valve to move from one position to the other. Several damping and energy recovery schemes are also included.
In copending application Ser. No. 153,257, now U.S. Pat. No. 4,878,464, entitled PNEUMATIC ELECTRONIC VALVE ACTUATOR, filed Feb. 8, 1988 in the names of William E. Richeson and Frederick L. Erickson and assigned to the assignee of the present application there is disclosed a somewhat similar valve actuating device which employs a release type mechanism rather than a repulsion scheme as in the previously identified U.S. Patent. The disclosed device in this application is a jointly pneumatically and electromagnetically powered valve with high pressure air supply and control valving to use the air for both damping and as one motive force. The magnetic motive force is supplied from the magnetic latch opposite the one being released and this magnetic force attracts an armature of the device so long as the magnetic field of the first latch is in its reduced state. As the armature closes on the opposite latch, the magnetic attraction increases and overpowers that of the first latch regardless of whether it remains in the reduced state or not. This copending application also discloses different operating modes including delayed intake valve closure and a six stroke cycle mode of operation.
The forgoing as well as a number of other related applications all assigned to the assignee of the present invention and filed in the name of William E. Richeson or William E. Richeson and Frederick L. Erickson are summarized in the introductory portions of copending Ser. No. 07/294,728, now U.S. Pat. No. 4,875,441, filed in the names of Richeson and Erickson on Jan. 6, 1989 and entitled ENHANCED EFFICIENCY VALVE ACTUATOR.
Many of the later filed above noted cases disclose a main or working piston which drives the engine valve and which is, in turn powered by compressed air. The power or working piston which moves the engine valve between open and closed positions is separated from the latching components and certain control valving structures so that the mass to be moved is materially reduced allowing very rapid operation. Latching and release forces are also reduced. Those valving components which have been separated from the main piston need not travel the full length of the piston stroke, leading to some improvement in efficiency. Compressed air is supplied to the working piston by a pair of control valves with that compressed air driving the piston from one position to another as well as typically holding the pistion in a given position until a control valve is again actuated. The control valves are held closed by permanent magnets and opened by pneumatic force on the control valve when an electrical pulse to a coil near the permanent magnet neutralizes the attractive force of the magnet.
In these later filed cases which disclose a main or working piston and separate control valves, a portion of the main piston cooperates with the control valves to achieve the desired control. Moreover, the cooperating portion of the main piston invariably has multiple diameters to achieve these results. Simplification of the main piston shape and the correlative reduction in the cost thereof would be highly desirable. Utilization of a straight section of such a main piston to provide piston bearing support, piston sealing and a portion of the cooperative valving would also be highly desirable.
These devices of these cases also require permanent magnets sufficiently strong to overcome the high pressure air effect on the control valve. It would be desirable to reduce the area of the control valve subjected to this high pressure air thereby reducing the air pressure force on the control valve and, therefor, also reducing the size and cost of the permanent magnet required to oppose that air pressure force.
In the devices of these applications, air is compressed by piston motion to slow the piston (dampen piston motion) near the end of its stroke and then that air is abruptly vented to atmosphere. A more controlled and gentle release of the air would tend to smooth the motion and quiet operation.
On extremely rare occasions the mechanism of these applications may be stranded in its midway position when the mechanism is turned off and some scheme for initializing, i.e., moving the piston to one of its extreme positions on start-up is desirable.
Variations in engine speed and other operating parameters take their toll on the source of compressed air and it is difficult to maintain a constant high pressure air source. It has been found that a regulator to maintain a constant ratio of the high pressure to the intermediate (latching) pressure reduces the problems of pressure source pressure variations.
Finally, it has been observed that the latch plates which, in conjunction with the permanent magnets, hold the control valves closed may tend to stick in the closed position due to the surface tension of oil being trapped in a very thin film across a large area, and, moreover, that these latch plates require some final hand adjustment relative to the control valve seal to achieve proper mechanism operation. Annular and radial relief grooves in the face of the latch plate relieves this surface tension sticking problem and provides some other unexpected benefits. An adjustable coupling between the latch plate and its control valve speeds adjustment of the mechanism.
The above noted aspects are, for lack of a better term, problem areas all of which are addressed by the present invention, and any one of which may be improved upon independent of the others to provide some measure of improvement in overall mechanism operation.
The entire disclosures of all of the above identified copending applications and patents are specifically incorporated herein by reference.
Among the several objects of the present invention may be noted the provision of a bistable transducer which implements a solution to each of the above noted problem areas; the provision of a fast acting, reliable and economical internal combustion valve actuating mechanism; the provision of a valve actuator having an adjustable latch plate; the provision of a valve actuator having a latch plate with a surface tension reducing face; the provision of a pressure ratio regulator for a pressure actuated valve actuator; the provision of an initialization routine preparatory to starting an air powered valve system; the provision of valve actuator with a piston having a three function, one diameter subpiston to either side thereof; the provision of a throttled step in pressure release of damping air in a valve actuating mechanism; and the provision of a number of different techniques to reduce the cost of a permanent magnet used to latch a control valve in a valve actuating mechanism. These as well as other objects and advantageous features of the present invention will be in part apparent and in part pointed out hereinafter.
In general, an electronically controllable pneumatically powered valve actuating mechanism for use in an internal combustion engine has a power piston reciprocable along an axis and adapted to be coupled to an internal combustion engine valve along with a pneumatic arrangement for moving the piston, thereby causing an engine valve to move between valve-open and valve-closed positions. The pneumatic arrangement includes a pair of control valves movable relative to the piston for selectively supplying high pressure air to the piston and a pneumatic damping arrangement for imparting a first decelerating force to the piston when the engine valve reaches a first separation from one of the valve-open and valve-closed positions to begin reducing engine valve velocity as the engine valve approaches that one position, and for imparting a second lesser decelerating force to the piston when the engine valve reaches a second lesser separation from that one position. This two stage damping and blow-down reduces the likelihood of damping induced oscillation or bounce of the valve at the extremes of its motion.
Also in general and according to one aspect of the invention, an electronically controllable pneumatically powered valve actuating mechanism for use in an internal combustion engine has a power piston reciprocable along an axis. The power piston is adapted to be coupled to an engine valve and has a pair of spaced apart enlarged diameter cylindrical portions for providing a sliding seal to confine high pressure air which has been supplied to the piston as well as providing a pair of sliding bearing surfaces for supporting the piston. A pneumatic arrangement supplies high pressure air to the piston causing the piston and engine valve to move in the direction of stem elongation between valve-open and valve-closed positions. A permanent magnet latching scheme, including a control valve, renders the pneumatic arrangement ineffective, but may be released allowing the pneumatic arrangement to move the control valve. The enlarged diameter cylindrical portion is also responsive to control valve motion to stop the supply of high pressure air to the piston. The air control valve includes an inner cylindrical surface which slidingly engages a portion of the outer surface of one of the enlarged diameter cylindrical portions of the power piston. This inner cylindrical surface includes a strengthened end portion of reduced inner diameter for threadedly receiving a magnetic latch plate and is too small to receive the enlarged diameter cylindrical portion of the piston.
Still further in general, a bistable electronically controlled pneumatically powered transducer has an armature which is reciprocable between first and second positions by an air pressure source and an air control valve which cooperate to cause the armature to move. A permanent magnet latching arrangement holds the air control valve in a closed position and an electromagnetic arrangement temporarily neutralizes the effect of the permanent magnet latching arrangement to open the air control valve and cause the armature to move from one position to the other. A resilient member cooperates with and is deformed by the air control valve to prevent the application of armature moving air pressure to the armature when the air control valve is in the closed position, and the amount of deformation of the resilient member when the air valve is in the closed position is adjustably selectable.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a view in cross-section of a valve actuating mechanism incorporating the invention in one form;
FIGS. 2-7 are views in cross-section similar to FIG. 1, but illustrating the sequential motion of the components as the piston moves from its extreme left to its extreme right position;
FIGS. 8a and 8b are enlarged sectional views of a portion of FIGS. 4 and 6 respectively illustrating the two stage release of damping pressure;
FIG. 9 is an enlarged sectional view of another portion of FIG. 1 illustrating the area limiting feature of the air control valve as well as the adjustable latch plate feature of the present invention;
FIGS. 10a and 10b are enlarged sectional views of a further portion of FIG. 1 illustrating initialization of the valve actuating mechanism;
FIG. 11 is a view in cross-section of a differential pressure regulator in accordance with the invention in one form; and
FIGS. 12a and 12b are orthogonal views, one in cross-section, of the flux transmitting surface of a modified control valve latch plate according to the present invention.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawing.
The exemplifications set out herein illustrate a preferred embodiment of the invention in one form thereof and such exemplifications are not to be construed as limiting the scope of the disclosure or the scope of the invention in any manner.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The overall valve actuator is illustrated in cross-section in FIG. 1 in conjunction with which various component locations and functions in moving a poppet valve or other component (not shown) from a closed to an open position will be described. Motion in the opposite direction will be clearly understood from the symmetry of the components. The actuator includes a shaft or stem 11 which may form a part of or connect to an internal combustion engine poppet valve. The actuator also includes a low mass reciprocable piston 13, and a pair of reciprocating or sliding control valve members 15 and 17 enclosed within a housing 19. The piston and control valves reciprocate along the common axis 12. The control valve members 15 and 17 are latched in one (the closed) position by permanent magnets 21 and 23 and may be dislodged from their respective latched positions by energization of coils 25 and 27. The permanent magnet latching arrangement also includes ferromagnetic latch plates 20 and 22 which are iron or similar ferromagnetic members and are attached to and move with the air control valves 15 and 17. The control valve members or shuttle valves 15 and 17 cooperate with the cylindrical end portions 24 and 26 of piston 13 as well as with the housing 19 to achieve the various porting functions during operation. The housing 19 has a high pressure inlet port 39, a low pressure outlet port 41 and an intermediate pressure port extending from the sidewall apertures 43. The low pressure may be about atmospheric pressure while the intermediate pressure is about ten psi. above atmospheric pressure and the high pressure is on the order of 100 psi. gauge pressure.
When the valve actuator is in its initial state with piston 13 in the extreme leftward position and with the air control valve 15 latched closed, the annular abutment end surface 29 of the control valve seals against an O-ring 31. This seals the pressure in cavity 39 and prevents the application of any moving force to the main piston 13. The high pressure cavity 39 is similarly sealed by a symmetric O-ring 32. In this position, the main piston 13 is being urged to the left (latched) by the pressure in cavity or chamber 35 which is greater than the pressure in chamber or cavity 37. When it is desired to open, e.g., an associated engine intake or exhaust valve, coil 25 is energized and the current flow therein induces a magnetic field opposing the field of the permanent magnet 21. With the magnetic latching force on plate 20 thus essentially neutralized, the unbalanced force of the high pressure air against surface 29 moves the control valve 15 leftward as viewed from the position of FIG. 1 to the position illustrated in FIG. 2 where an annular opening is just beginning to form near the O-ring 31 between the control valve 15 and edge 47 of the housing 19.
In FIGS. 1 and 2, the piston 13 has not yet moved from its leftmost position. In one illustrative embodiment, the desired engine valve opening and thus, the maximum piston movement was 0.390 inches as shown in FIG. 7. In this case, piston displacement is 0.140 inches in FIG. 3, 0.240 inches in FIG. 4, 0.320 inches in FIG. 5 and 0.350 inches in FIG. 6. Similarly, in FIGS. 1, 6 and 7, the air control valve 15 is closed and is opened 0.035 inches in FIG. 2, 0.070 inches in FIG. 3, 0.085 inches in FIG. 4, and has nearly reclosed to only 0.025 inches in FIG. 5. Such figures are illustrative and provided for comparison purposes only.
FIG. 3 illustrates completion of this annular opening admitting high pressure air from chamber 39 into chamber 37 forcing the piston 13 rapidly toward the right. As the piston 13 continues its rightward motion, edge 49 cooperates with cylindrical end portion 24 (which is an enlarged subpiston portion of the piston 13) to close off the annular opening and remove the high pressure air supply from source 39 to chamber 37. This reclosure of the annular opening (as opposed to reclosure of the control valve 15 which does not happen until FIG. 6) is shown in FIG. 4. The piston 13 now moves as the air in chamber 37 continues to expand until further rightward movement of the piston as depicted in FIG. 5, uncovers the partial annular apertures 43 leading to intermediate pressure port so that the high pressure air in chamber 37 begins to blown down to the intermediate pressure. Also in FIG. 4, it will be noted that while the high pressure source 39 is no longer supplying air to drive the piston 13, the high pressure is maintained in chamber 51 so that the effective pressure differential is only that acting on annular area 53. While the air control valve 15 has begun to close in FIG. 5, the pressure in chambers 39 and 51 is substantially the same and when, in FIG. 6, the chamber 51 is vented to atmosphere, the area exposed to the high pressure is reduced back to surface 29 as depicted in FIGS. 1 and 9.
Beginning with FIG. 3, the piston 13 has closed the intermediate or "latching" pressure apertures 43 and the air captured in chamber 35 is being compressed to dampen or slow the piston motion. In FIGS. 4 and 5, a portion of this pressure is being slowly released as shown in FIG. 8a, while in going between FIGS. 6 and 7 the remaining pressure is suddenly removed in the manner depicted in FIG. 8b.
FIGS. 4 and 8a show the corner 55 of subpiston segment 26 just after it clears the corner 57 of housing 19. These corners are much more easily seen in the enlarged view of FIG. 8a. Prior to this time, the pressure in chamber 35 has been increasing rapidly. An annular opening is just beginning to form at 59 between the abutting corners 55 and 57. This annular opening slowly vents the high pressure air from chamber 35 as the piston continues its rightward journey to more gradually slow the piston motion as it approaches its right hand resting position. As shown in FIGS. 6 and 8b, just prior to the piston reaching that righthand extreme position, the corner 55 clears corner 61 and the heretofor small annular opening 59 becomes large allowing the remaining superatmospheric pressure air to rapidly escape chamber 35 to help prevent any rebound of the piston 13 back toward the left. This two stage venting or blow-down provides a more gradual and more easily controlled deceleration of piston motion.
The main piston 13 has reached its righthand extreme in FIG. 7, the respective annular openings 59 and 63 are venting chambers 35 and 51 to low, essentially atmospheric, pressure and the piston 13 is held or latched in the position shown by the intermediate pressure in chamber 37 from the intermediate pressure source openings 43. The return or leftward piston motion from the position of FIG. 7 back to that of FIG. 1 upon energization of coil 23 follows essentially the same sequence of events as has been described and should be clear from the symmetry of the actuator.
The tasks of the magnets 21 and 23 are to hold the air control valves 15 and 17 in their closed positions until neutralized by energization of the corresponding one of the coils 25 or 27 and to reclose the control valves subsequent to actuation. These holding and restorative forces required of the magnets are determined primarily by the force exerted by the internal unbalanced air pressure acting on the corresponding control valve. That force is, in turn, proportional to the projected component of valve area 29 in a plane normal to axis 12 which is exposed to unopposed high pressure air within the actuator. A reduction in this effective area will result in a reduction in the required magnetic field, a reduction in the size and cost of the magnets, and a reduction in the required ampere turns required of the coil to neutralize that magnetic field. Such an area limiting feature is best understood by referring to FIG. 9. The area reduction is made possible by reducing the valve cross-sectional area where unbalanced air pressure problems will be experienced. Such an area decrease facilitates the latch plate adjustment feature to be discussed subsequently in conjunction with FIG. 10. The control valve of FIG. 9 includes a thin walled portion 87 having an inner cylindrical surface 89 which slidingly engaging a portion of one of the enlarged diameter cylindrical portions 24 of the armature. The inner cylindrical surface 89 includes an end portion 91 of enhanced strength and reduced inner diameter which is too small to receive the enlarged diameter cylindrical portion or subpiston 24 of the armature. The enlarged diameter cylindrical portion responds to or cooperates with the control valve motion to stop the supply of high pressure air to the piston at the appropriate time. The control valve 15 when in the open position is subjected to the pressure of the source of high pressure fluid over the cross-sectional area of the thin walled portion 87 of the control valve in a plane normal to the axis 12 so that the effective area subjected to high pressure air after the control valve has opened is minimized thereby minimizing the restorative force required of the permanent magnet in reclosing the control valve. The ratio of this smaller air (control) valve area exposed to the internal unbalanced high pressure is less than 25% of the area exposed to the internal balanced pressure.
In FIG. 9, the O-ring 31 is a resilient member which cooperates with and is deformed by the air control valve 15 to prevent the application of armature moving air pressure from chamber 39 to the chamber 37 when the air control valve is in the closed position. The amount of deformation of the resilient member 31 when the air valve is in the closed position may be adjustably selected by movement of the latch plate 20 along the threaded portion 93 of air control valve 15. The diameter reduction at ledge 91 leads to an enhanced strength region which is threaded at 93 to receive latch plate or armature 20 and a lock nut 95 threadedly engaging the control valve and abutting the latch plate. A plurality of threaded fasteners such as set screw 97 pass transversely through the lock nut 95 and into locking engagement with the latch plate 20. The latch plate abuts the housing when the control valve is closed and functions as a member movable with the control valve for limiting control valve motion toward the seal. The threaded coupling between the member 20 and the air control valve provides for presetting the force applied to the seal by the air control valve. Prior to the present invention, this pressure was set by a trial and error technique of putting shims between the latch plate and a shoulder on the actuator body. Such a time consuming shim technique did not allow for matching the differential seal pressure to any variations in source pressure nor to variations in the delatching pulse driver energy levels.
In rare cases, the actuator may have the piston resting in other than one of its extreme positions. An initializer as shown in FIG. 10a and 10b is a device used to preposition the actuator piston in either of the extreme positions regardless of what intermediate position in which the piston might happen to be. The initializer may be used to obtain a desired initial position for the engine poppet valve (either open or closed) preparatory to starting the engine or at other times when it is desired to reset the valve to an open or closed position. Initialization is accomplished by three distinct actions. The source pressure is supplied to one of the chambers 35 or 37, i.e., to one face of the piston 13. The air which might otherwise be trapped in the other of the chambers 35 or 37 is vented to atmosphere. The centrally located intermediate pressure ports 43 must not be allowed to vent high pressure air from the cylinder and are somehow temporarily blocked.
In FIG. 10a, the initializer is in its non-actuated position while in FIG. 10b, is activated. The initializer is fastened as by bolts to one side of an actuator. The actuator includes openings 65 and 67, to adapt it to the initializer. The initializer comprises a cylinder 69 and a control piston 71 having first and second ends 73 and 75 and a reduced diameter intermediate section 77 movable within the cylinder. Application of high air pressure through inlet 79 to the first end 75 moves the control piston against the bias of spring 81 from its inactive position as shown in FIG. 10a, to an initializing position of FIG. 10b. The control piston cylinder 69 is ported to atmosphere at 83 and 85 and to establish pneumatic communication between the high pressure air and one side of said power piston at 79. The piston portion 75 is effective to seal off the intermediate air pressure path from the power piston 13 cylinder via 43 and 86 when it is in the initialized position. The control piston 71 is urged by spring 81 to a return position upon removal of said high pressure air from end 75 and in the returned position, the piston effectively seals the high pressure air inlet 67 and the low pressure air outlet 65 while unsealing the intermediate air pressure path 43-86 from the power piston cylinder. As illustrated, the initializer moves the power piston to its leftmost location which would typically correspond to the engine valve being closed. To configure a particular actuator to always move the engine valve to an open position, the initializer is merely fastened to the side of the actuator end-for-end from the orientation shown. Like spacing of openings such as 65 and 67 will facilitate this reversibility.
In FIG. 11, a differential pressure regulator for maintaining the ratio of the high air pressure (in chamber 39) to the intermediate or latching air pressure (the initial damping pressure at ports 43) constant is shown. When this ratio is maintained nearly constant despite variations in the pressure of the high pressure source, then critical damping of piston motion can also be maintained. The bistable actuator of the present invention has a piston which is held in either of its extreme positions by a latching air pressure and when commanded to change states, it does so by applying a high line pressure in opposition to the latching pressure, i.e., to the opposing face of piston 13. During the change of state, the latching force is overcome causing a slight increase in the latching pressure and an escape of air through the apertures 43. When ports 43 are closed by piston movement, the captured gas provides a stopping force which, if properly controlled in level as a function of time, can critically damp the piston motion. Critical damping depends on the correct damping air pressure at the time the openings 43 are closed relative to the applied high pressure which is driving the piston. For example, an increase in high pressure means the piston is being driven harder, is moving faster, and requires a greater retarding force to be stopped. An increase in intermediate air pressure will provide such an increase in the retarding force. A constant ratio between the source and latching pressures and rapid pressure regulator response time on the same order as the actuation time of the actuator have been found to be highly desirable.
In FIG. 11, the high pressure line connects to port 99 while the intermediate or latching pressure is present at port 101. For example, if it is desired to maintain a ratio of 10:1, the area of the annular piston surface 103 would be ten times the area of piston 105 and with a source pressure of 100 psi. The pressure at port 101 would be 10 psi. If source pressure were to drop to, e.g., 90 psi., the force on piston face 105 would decrease and piston 103 would move to the left increasing the opening of the outlet 107 and increasing the air flow out of opening 107 until the pressure at port 101 decreases to a value 1/10 of 90 psi. which is 9 psi. At that time the opposing forces would again be balanced. Also, as shown in FIG. 11, an accumulator can be connected to threaded opening 113 in order to provide a means of damping the pressure pulses inside the regulator.
The regulator of FIG. 11 is coupled to each of the source pressure 99, an intermediate pneumatic pressure 101 higher than said initial damping pressure, to an accumulator at 113, and to an exhaust pressure at 107 (frequently atmospheric pressure) which is lower than the initial damping pressure. The regulator senses instantaneous source pressure and continuously balances the intermediate pressure and exhaust pressure to obtain an instantaneous initial damping pressure that will provide the desired ratio. The regulator has a regulating piston reciprocable along an axis 115 and having a first surface 103 which is subjected to intermediate pressure to drive the regulating piston in one axial direction and a second surface 105 subject to source pressure to drive the piston in the opposite axial direction against the force on the first surface. The first surface area is a predetermined amount larger than the second surface area with that predetermined amount being chosen so that the regulating piston will move in the first axial direction (left as viewed) to admit the exhaust pressure at 107 to the atmosphere. This will decrease the initial damping pressure at 101 when the force on the first surface is greater than the force on the second surface until the force on the second surface moves the regulating piston in the second axial direction to seal the exhaust pressure from the atmosphere and to increase the initial damping pressure, thereby continuously maintaining the predetermined ratio between the initial damping pressure and the source pressure as determined by the ratio of the first surface area to the second surface area. The opening 109 is typically a vent to atmospheric pressure, but may provide for adjusting the predetermined ratio by applying a variable pneumatic bias pressure to the surface 111.
In FIGS. 1-7 the ferromagnetic latch plate or armature 20 appears to rest directly on the ferromagnetic pole pieces 115 and 117. The latch plate may be held very tightly in this position for two reasons. With no air gap between these two parts, the path reluctance is quite low, the flux quite high and the parts may be driven into magnetic saturation. Whatever lubricating medium the system employs will eventually find its way onto the latch plate surface which faces the actuator and pole pieces. The surface tension of the lubricant will significantly increase both the force and the variability of the force required to separate the two parts. Such variability introduces variations in opening time and required damping. The flux could be reduced by using a smaller magnet, but then the required force at a distance to reclose the control valve would be lacking. Saturation could be reduced or eliminated by utilizing additional iron, but this creates a slower heavier and more costly device. The introduction of a nonmagnetic gap when the members are closed on one another will solve the magnetic problems and such a gap with air passageways will reduce the lubricant surface tension problems.
To reduce the surface tension and to reduce the magnetic holding force on the latch plate 20, a nonmagnetic surface of, for example, brass 0.015 inches in thickness is created to space at least part of said flux transfer surface of the plate from the flux transmitting surface of the pole pieces 115 and 117 when the control valve 15 is in the closed position whereby the magnetic flux between the surfaces is measuredly decreased in the closed location so that the force required to overcome the attraction between the surfaces is substantially decreased and any liquid surface tension due to any lubricating liquid residues when the surfaces are in contact is minimized. The spacing arrangement is best seen in FIGS. 12a and 12b. The spacing arrangement includes at least one arcuate rim such as 119 extending from one of the flux transmitting and flux transfer surfaces and abutting the other of the surfaces when the control valve is in the closed location. As illustrated, a plurality of concentric circular arcuate rims are spaced from one another along a radius common to all the circular rims. A slot such as 121 is formed in the surface and across the rim for providing liquid passage for liquids collected and contained along and adjacent the rim. An opening such as the hole 123 is also provided in liquid communication with each of the slots to provide a liquid drain for any liquid in any of the slots. As shown, there are two openings and four arcuately equispaced radial slots each in liquid communication with the openings.
Little has been said about the internal combustion engine environment in which this invention finds great utility. That environment may be much the same as disclosed in the abovementioned copending applications and the literature cited therein to which reference may be had for details of features such as electronic controls and air pressure sources.
From the foregoing, it is now apparent that a novel electronically controlled, bistable pneumatically powered valve actuator has been disclosed meeting the objects and advantageous features set out hereinbefore as well as others, and that numerous modifications as to the precise shapes, configurations and details may be made by those having ordinary skill in the art without departing from the spirit of the invention or the scope thereof as set out by the claims which follow. | An electronically controllable pneumatically powered valve actuating mechanism for use in an internal combustion engine is disclosed. The engine is of the type having engine intake and exhaust valves with elongated valve stems. The actuator has a power piston reciprocable along an axis and adapted to be coupled to an engine valve and a pneumatic arrangement for moving the piston. A pneumatic damping arrangement imparts a first decelerating force to the piston when the engine valve reaches a first separation from one of said valve-open and valve-closed positions to begin reducing engine valve velocity as the engine valve approaches said one position, and imparts a second lesser decelerating force to the piston when the engine valve reaches a second lesser separation from that one position. A resilient member cooperates with and is deformed by the air control valve to prevent the application of piston moving air pressure to the piston when the air control valve is in the closed position, and included is an arrangement for adjustably selecting the amount of deformation of the resilient member when the air valve is in the closed position. An initializer to force the piston to one of its extreme positions upon start up, a pressure regulator, and an arrangement for minimizing surface tension induced valve sticking problems are also disclosed. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates generally to an aqueous base lubricant, and more specifically to a lubricant for the high temperature application upon surfaces of a glass shear, or otherwise upon relatively movable metallic surfaces at high temperature. The lubricant contains a substantial quantity of coconut oil together with an alkanolamine, the phosphate ester of a linear primary alcohol, an emulsifier, a primary amine and a wetting agent. The lubricant formulation of the present invention is usable at modest concentrations, hence rendering the material cost effective, and furthermore reducing any unusual load on sewage treatment facilities.
The present invention was specifically designed to accommodate certain unique requirements of the glass industry. In the process of making glass containers, a cylinder of molten glass is extruded and cut by shear blades into a "gob". The molten glass gob then leads into the mold chamber by sliding down a loading chute. The molten glass is highly abrasive to both the shear blades and loading chute. A mixture of water and a lubricant is sprayed onto the shear blades and loading chute to assure a continuation of efficient and precise shear cuts and loading times.
It is necessary therefore for the efficient production of quality glassware, that the following conditions be met:
1. Lubricity must be adequate for the continuous protection of the shear blades and loading chute.
2. Corrosion inhibition is necessary for the protection of all surfaces which come into contact with the aqueous lubricating solution.
3. The lubricant must be composed of non-drying components such that a hard film does not form or is otherwise built-up on shear blades resulting in poor heat transfer and inefficient gob cuts.
4. The lubricant must be able to provide lubrication at minimal concentrations in water to produce maximum cooling benefits.
5. The lubricant must provide good surface wetting characteristics in order to assure efficient heat transfer at the shear blades.
6. The lubricant must be biodegradable since essentially all shear lubrication systems are based upon a once-through, non-recirculating system with the spent lubricant solution entering municipal water treatment facilities.
Since the temperature of the molten glass in contact with the shear blades is normally in the vicinity of 2000° F., cooling of the shear blades is a primary concern. Generally speaking, the lubricants best suited for cooling efficiency are the water-based lubricants.
Since lubrication of the shear blades and loading chute is necessary for the production of high quality glassware and since a lubricating film must be present a high water-to-lubricant dilution, the lubricant must possess excellent lubrication properties. Generally speaking, the compounds offering the best lubricity are oil-based lubricants.
The present invention combines the best properties of soluble oil lubricants and water-based lubricants. In other words, the invention is considered to be a hybrid of oil-based and synthetic lubricants; thus a semi-synthetic. The definition of semi-synthetic is essentially a compound containing oil in which the oil component comprises less than 50% by weight of the total non-aqueous component fractions of the formulation. Water, therefore, may be present in a semi-synthetic product but normally is not considered when computing the percentage of oil present in the formulation.
The importance of lower levels of oil can be appreciated by considering the problems of pollution in a once-through system wherein the spent lubricant is discharged into the environment. While animal and vegetable oils are considered biodegradable, their BOD values are high enough to warrant efforts to decrease the amount discharged into the environment or into municipal sewage systems. Often municipalities impose surcharges on the sewage treatment rates of a manufacturing or commercial facility dependent on the BOD or COD of their effluent.
The present invention therefore provides a lubricant having lubricating properties essentially equal to those of the soluble oil products at equal or greater dilutions while reducing the amount of oil used in the process.
The primary lubricant component of the invention is the non-drying vegetable oil, with coconut oil being preferred. The alkanolamine, methyl ester and phosphate ester are lubricant additives. The function of the lubricant additives is to lower the percentage of oil necessary to maintain efficient lubrication, with the methyl ester functioning as a primary wetting agent. Additionally, the methyl ester provides secondary emulsion stability. The emulsifier system is composed of an ethyoxylated sorbitol hexaoleate. Secondary emulsion stability is also provided by the primary amine and phosphate ester. Corrosion inhibition is afforded to the product by the alkanolamine, primary amine and phosphate ester. Bacterial degradation and rancidity are inhibited by the primary amine.
SUMMARY OF THE INVENTION
A primary object of this invention is to provide an environmentally compatible lubricant useful at high dilution rates in aqueous solutions for the shear blades and loading chute of glass container producing machines, with the formulation including an oil, an emulsification system, lubrication additives and corrosion inhibitors.
A further object of the invention is the inhibition of corrosion on those surfaces contacted by the lubricant-water solution.
A further object of the invention is the virtual prevention or reduction of bacterial degradation of the concentrated product while allowing for biodegradation in the working solution at lower concentration levels.
A further object of the invention is the improvement of cooling of the shear blades through wetting by providing a water interface with inclusion of a wetting agent.
A further object of the invention is the prevention of the build-up of a hard or tacky film formation on surfaces contacted by the lubricant through the incorporation of non-drying components and an efficient emulsifier system.
Other and further objects of the present invention will become apparent to those skilled in the art upon a study of the following specification and appended claims.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In order to best disclose the properties of the preferred embodiment, the following specific formulation is provided:
EXAMPLE 1
______________________________________ Percent byComponent Weight______________________________________Non-drying vegetable oil(refined coconut oil) 15.00Alkanolamine (triethanol amine,widely commercially available) 7.00Phosphate ester (the reaction productof the ethylene oxide adduct of alinear primary alfol alcohol blendhaving the following structuralformula:CH.sub.3 (CH.sub.2).sub.X CH.sub.2 (O CH.sub.2 CH.sub.2).sub.n OHwhere the value of "X" is approximately11 and "n" is 3. This material iscommercially available fromContinental Oil Company of New YorkCity, New York under the designation"Alfonic 1412-40", and polyphosphoricacid 115% widely commerciallyavailable) 3.00Emulsifier (ethoxylated sorbitalhexaoleate available commerciallyfrom Emery Industries, Inc. of -Cincinnati, Ohio under the tradename "Trylox 6747") 6.00Primary amine (the fatty nitrogenderivative of distilled coconutoil primary amine, availablecommercially under the designation"Kemamine P-650D" from Humko Products,Division of Kraftco Corporation,Memphis, Tennessee) 2.00Wetting agent (the methyl estermixture of a 50:50 methyl palmitateand methyl oleate availablecommercially as "Stepan C65" fromStepan Chemical Company ofNorthfield, Illinois) 4.00Water balance______________________________________
In order to provide a variety of related formulations which perform the functions of the formulation of Example 1, the following table is presented as related to Example 1 wherein the useful ranges of the components is set forth hereinbelow:
TABLE 1______________________________________Component Percent by Weight______________________________________Non-drying vegetable oil(preferably refined coconut oil) 5.0 to 40.0Alkanolamine (preferablytriethanolamine widelycommercially available) 1.0 to 20.0Phosphate ester (the reaction productof the ethylene oxide adduct of alinear primary alfol alcohol blendhaving the following structuralformula:CH.sub.3 (CH.sub.2).sub.X CH.sub.2 (O CH.sub.2 CH.sub.2).sub.n OHwhere the value of "X" is approximately11 and "n" is 3. This material iscommercially available fromContinental Oil Company of New YorkCity, New York under the designation"Alfonic 1412-40", and polyphosphoricacid 115% widely commerciallyavailable) 0.5 to 10.0Emulsifier (preferably ethoxylatedsorbitol hexaoleate availablecommercially from Emery Industries,Inc. of Cincinnati, Ohio under thetrade name "Trylox 6747") 2.0 to 15.0Wetting agent (preferably the methylester mixture of a 50:50 mixture ofmethyl palmitate and methyl oleateavailable commercially as "Stepan C-65"from Stepan Chemical Company ofNorthfield, Illinois) 0.5 to 10.0Primary amine (preferably the fattynitrogen derivative of distilledcoconut oil, primary amine,available commercially as"Kemamine P-650D" from HumkoProducts, Division of KraftcoCorporation of Memphis, Tenn.) 0.1 to 8.0Water Balance______________________________________
The working solution is prepared by the addition of the present invention to water while mixing. The resulting emulsion is stable in hard, soft or distilled water for at least two days without further agitation. With occasional agitation, the emulsion is stable essentially indefinitely. The preferred range of dilution is 1 part of the formulation of Example 1 to from 50 to 800 parts of water. Optimum dilution is generally 1 part the formulation of Example 1 to 500 parts of water. The invention has been found to exhibit the characteristics described above when used in the afore-mentioned dilution ratios.
DISCUSSION OF THE SELECTED COMPONENTS
Each component of the formulation was selected to provided specific functions in the working solution. These components and advantages are discussed below.
(A) Refined Coconut Oil
This oil was chosen as the main lubricating agent because of its excellent lubricating properties under the intended application, as well as its commercial availability, low odor, biodegradability and non-drying characteristics.
(B) Phosphate Ester
Several phosphate esters of linear, primary alcohols which are commercially available have been found to be effective in this invention. The preferred phosphate ester is prepared by following the procedure outlined below.
Synthesis of Preferred Phosphate Ester
The raw materials for the reactant mixture are:
(i) An ethylene oxide adduct of a linear, primary alfol alcohol blend having the structural formula:
CH.sub.3 (CH.sub.2).sub.X CH.sub.2 (OCH.sub.2 CH.sub.2).sub.n OH
where the value of "X" is approximately 11 and "n" is 3 (commercially available).
(ii) Polyphosphoric acid 115% (readily commercially available).
The phosphate ester is composed of 79.68% by weight of the alfol alcohol ethyoxylate and 20.32% by weight of polyphosphoric acid 115%.
The alfol alcohol ethoxylate is charged to a clean, dry, stainless steel mixing tank equipped with a mixer. The temperature is brought to 120° F.
The polyphosphoric acid 115% is added to the mixing tank with agitation and the mixture is brought to a temperature of 220° F. and allowed to react for four hours at that temperature. The reacted material is subsequently cooled and checked for quality. The pH of the phosphate ester is approximately 2.1.
The phosphate ester has been found to provide extreme pressure lubrication in the overall formulation and also aids in emulsion stabilization and corrosion inhibition.
(C) Alkanolamine
The preferred alkanolamine is triethanolamine although diethanolamine is also effective in the formulation. The alkanolamine is used to adjust the pH of the formulation between 7.0 and 10.0. The alkanolamine also aids in corrosion inhibition and surface boundary lubrication.
(D) Methyl Ester
The preferred methyl ester is one which is a mixture of 50% by weight methyl palmitate and 50% by weight methyl oleate. The methyl ester may comprise methyl palmitate or methyl oleate, as well as the preferred mixture set forth. This component is an efficient wetting agent and has been shown to provide emulsion stabilization and lubrication characteristics in the formulation.
(E) Primary Amine
The preferred primary amine is the fatty nitrogen derivative of distilled coconut oil primary amine. This material offers corrosion inhibition as well as emulsion stabilization in the formulation. The component also inhibits bacterial degradation of the concentrated formulated product.
(F) Emulsifier
The preferred emulsifier is ethyoxylated sorbitol hexaoleate.
Preparation of the Invention
The present invention is prepared by premixing the oil soluble components until a uniform mixture is formed. All components with the exception of water are considered oil soluble. When a non-aqueous concentrate is desired, the procedure is complete at this point. If a preformed emulsion is the desired finished product, the water is then added, slowly, with agitation, to the oil soluble components. This procedure provides an inverted, oil-in-water emulsion which is stable in hard, soft or distilled water.
Description of the Emulsion Formed
The initial few percent of water are readily emulsified by the oil components forming a water-in-oil emulsion. Upon the further addition of water, the emulsion inverts, becoming an oil-in-water emulsion. Inverted emulsions are generally considered to be more stable than non-inverted emulsions. | A semi-synthetic lubricant for high temperature applications, particularly adapted for use on relatively movable metallic surfaces during the shearing of molten glass, and consisting of an aqueous solution of a formulation comprising a non-drying vegetable oil, such as coconut oil, alkanolamine, the phosphate ester of an ethylene oxide adduct of a linear primary alcohol, an emulsifier, preferably the ethoxylated sorbitol hexaoleate, the fatty nitrogen derivative of distilled coconut oil primary amine, and a wetting agent. The wetting agent is preferably the methyl ester of a 50:50 mixture of methyl palmitate and methyl oleate. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a laboratory apparatus for a wet treatment of textile materials, including a specimen carrier being located in an exactly defined path of flow of a treatment liquid in a treatment chamber which in turn is integrated with a structural unit a conveying unit for the treatment liquid.
The application of such laboratory apparatuses is to examine and influence the physical and technical parameters of a treatment procedure by scientific methods prior to using such on a large technical scale.
2. Description of the Prior Art
A laboratory apparatus of the kind set forth above is disclosed the Swiss patent specification CH-PS 538 303 which apparatus comprises a treatment liquid conveying means which includes two conveying chambers which are open at two opposed sides and are closed towards the outside by two conveying membranes which are driven synchronously and oscillatingly in the same sense.
Such conveying means allows a circulating of the treatment liquid without any losses due to leakage and without contamination by particles produced by wear.
The design leads, however, positively to the pulsating flow of the treatment liquid which is unsatisfactory regarding a treatment procedure which should represent a realistically practical procedure for technically large scale operations.
Quite often, such test runs to not lend themselves to reproduction.
Furthermore, a reversing of the direction of flow of the treatment liquid is possible only by means of a additional use of a reversing valve which influences detrimentally the flow delivery capacity, the dead or clearance, respectively volume as well as the costs.
A further drawback is created by the fact that the delivery or conveying, respectively, capacity of such a conveying means--considering the small dimensions demanded in a laboratory--under certain conditions cannot satisfy the prevailing demands made. A mere enlargment of the conveying spaces leads additionally to a worsening of the base relation which contradicts again the desire of a laboratory apparatus which produces realistic and reproducible results.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to provide a laboratory apparatus for a wet treatment of textile materials which produces realistic and reproduceable results.
A further object of the invention is to provide a laboratory apparatus in which the conveying unit comprises a pump having a rotating pumping means for generating a non-pulsating flow of the treatment liquid of which pumping means the sense of rotation is reversable whereby the flow in the flow passage can be reversed.
Another object is to provide a laboratory apparatus by means of which a exactly defined flow pass can be arrived at in the area of the textile material being treated which flow can be reversed within desired time intervals and in which the dead volume or dead space, respectively and accordingly the base relationship may be held in realistic dimensions. This will allow of the production in the laboratory of a true and reduceable representation of a technically large scale treatment procedure.
Still a further object is to provide a laboratory apparatus in which the direction of rotation of the conveying pump allows a direction of flow through the material being treated mounted to a specimen carrier in radial direction from the inside towards the outside and additionally also in the opposite direction.
A further object is to provide a laboratory apparatus in which the design of the specimen carrier is such that the flow of the treatment liquid through the specimen being treated is also possible in an axial direction thereof from the bottom to the top or also from the top to the bottom.
Still a further object is to provide a laboratory apparatus in which the flow capacity can be substantially increased together with an improvement of the base relation such that it can correspond completely to the demands made in laboratories.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be more fully understood and objects other than those set force 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 longitudinal section through a first preferred embodiment of the inventive laboratory apparatus;
FIG. 2 illustrates an axial section through a conveying unit located in the apparatus illustrated in FIG. 1;
FIG. 3 is a view of a section extending perpendicularly to the axis of the conveying unit of FIG. 2;
FIG. 4 is a longitudinal section through a second embodiment of the inventive laboratory apparatus;
FIG. 5 is an axial section of the conveying unit of the embodiment illustrated in FIG. 4; and
FIGS. 6 and 7 are sectional views of two specimen carrier sets removed from the apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a first embodiment of the laboratory apparatus for a wet treatment of textile materials which apparatus comprises basically a conveying unit 1 and a treatment chamber 2 which two structures are integrated to one structural unit. The apparatus further comprises a specimen carrier 3 located in the treatment chamber 2 and a exactly defined flow pass of the treatment liquid. The treatment chamber 2 is made up of basically three parts:
Firstly of a open topped cylinder 4 which is provided in the center of its bottom with two annular coaxially arranged openings for coupling with the feeding channel 7 and discharging, channel 8. The selected arrangement produces a flow characteristic in both radial directions of flow and which characteristic is extremely smooth. This cylinder is surrounded by heating or cooling, respectively coils 9,10 having a relatively small mass and extending at the side and at the bottom of the cylinder such that it is possible to achieve steep heating and chilling or cooling, respectively gradients with a low expenditure of energy.
The center part of the treatment chamber 2 comprises a transparent cylindrical intermediate piece 5 which is fixedly held by means of a tensioning device and which upon a simple loosening thereof can be pulled out laterally and exchanged respectively upon removal of the specimen carrier 3. The filling volume of the treatment chamber 2 can be adjusted by a suitable selection of a corresponding intermediate piece 5 which exchangeable intermediate pieces 5 have a constant height but varying diameters. A sealing system 12 secures the impeccable operation of this module - like arrangement. A cylinder 6 forms the upper part of the treatment chamber 2 which cylinder 6 is in turn closed at its upper end by a cover 13 having an integrated steam protection arrangement. The lower side of the cover 13 is provided with an edge 14 producing a defined forming of droplets.
Upon an opening of the cover 13 the specimen carrier 3 can be removed. By means of its lower tube-like designed end 15 the carrier 3 is positively centered in a specimen carrier receiving part. At the same time this tube shape section forms the inner flow channel 8 and is sealed against the outer channel 7 by means of a seal 16.
The treatment liquid exits the feeding channel 8 through an annular opening 17 from (or in case of a opposite flow is aspirated thereinto) and is urged by a displacement body 18 towards a specimen drum 19 having perforations and flows smoothly through the prevailing specimen 20 wound thereupon.
At its upper end the specimen carrier 3 is provided with a disk shaped closure 21 which centers the specimen carrier by means of a guide ring 22 relative to the treatment chamber. A line (not illustrated) line extends from a overflow valve 23 through the cover 13 or cylinder 6 such to allow the overflow scavenging of the apparatus (see herebefore).
Upon interrupting the feed flow by means of a interrupting apparatus 24 the specimen being treated can be contacted by external mediums (e.g. cold water/steam) feed via an infeed line 25 without influencing the treatment liquid.
Further possibilities of influencing and monitoring the treatment operation are provided by a apparatus 26 for removal of liquid and an apparatus 27 for a defined adding of auxiliary materials.
The monitoring and controlling of the operation is supported, furthermore, by two pressure sensors 28, 29 in the feeding and discharging, respectively channels 7,8, a means for an inductive measurement of the magnitude of the through flow, a temperature sensor 31 and a bypass system 32 for the determination of the actual extract of colour from the treatment liquid by means of a colourmetric probe or sampling device, respectively.
The lower part of the apparatus is surrounded by a integral casing 33 which can be slipped over and removed from the fixedly mounted parts of the apparatus without a disassembling, which greatly facilitates maintenance operations.
At its bottom, the casing 33 is closed by a bottom plate 34 which is designed as collecting vat.
A cleaning and feeding or draining, respectively system 35 which is coupled to a pump allows a complete draining of the apparatus and impeccable cleaning thereof.
A pivotable control unit 36 is integrated in the coverhood of the apparatus.
The conveying unit 1 comprises, as best illustrated in FIGS. 2 and 3, a rotary vane pump 37 and a motor 38 with a magnetic rotor which are interconnected via shaft 39. The permanent magnetic rotor 40 of the drive motor 38 is completely encased by a casing 41. It is driven by a rotating pot-shaped magnet located outside of the casing. Accordingly, the dead or clearance, resp. volume of the motor may be kept small and there is nothing that gives rise to sealing difficulties.
Due to the mounting of displacement bodies 42 the dead volume of the conveying unit is decreased still further.
The feeding and discharging, channels 7,8 are short circuited via through bores 43 through the drive space such that in case of a changing of the direction of feed a speedy pressure equalization is arrived at and accordingly no overloading of the drive motor is achieved.
In order to prevent a contamination of the treatment liquid by particles produced by wear of the vanes 44, the friction part 45, the roller or slider bearings 46, the rotor 47 as well as the bearing and mounting section 48 of the shaft 39 are provided with a layer of wear resistant and chemically resistant materials or fabricated of such materials (ceramic, glass, iron-chromium-nickel/triboloy-basis alloys). The two openings 49 in the pumping and drive section are used for draining and cleaning.
FIG. 4 illustrates a further embodiment of the invention which basically corresponds to the initially described embodiment with exception of the conveying unit 1. Accordingly, the description of the corresponding structures having the same reference numerals is not necessary. The conveying unit 1 has a design of a peripheral-wheel pump (see also FIG. 5). The peripheral wheel 50 comprises along its circumference lateral recesses 52 arranged staggered at the front and back side which recesses 52 cooperate with a pump channel 53. The feeding and discharging, respectively channels 7,8 open into this pump channel 53 (illustrated in FIG. 5 by broken lines). The peripheral wheel 50 can be rotated by a drive motor 52 in both senses of rotation such that the direction of feed can be reversed. The apparatuses 26,27 for the removal of liquid and the addition of auxiliary materials open directly into the pump channel 53, so as to secure an excellent distribution of such auxiliary materials in the treatment liquid. The same is true for the by pass system 32 for the determination of the actual colour extract from the treatment liquid. In order to prevent a contamination of the treatment liquid, the friction part 55 of the pump casing as well as the journal bearing 56 for the drive shaft 57 are covered by a layer of a chemical resistant material. At its exit out of the pump casing, the drive shaft 57 is sealed by a slide ring seal 58 and coupled to the motor shaft by a coupling 59.
The above description reveals that both embodiments incorporate pumps with a small dead or clearance volume which pumps operate reversably and impulse free and moreover can be excellently sealed also in case of aggressive treatment liquids. This allows an achieving of tests results which are close to actual practice and specifically are reproduceable in that controllable liquid flows can be generated.
The design of the specimen carrier 3 such as illustrated in FIGS. 6 and 7 has the same object. The centrally and coaxially located feeding and discharging channels 7,8 lead to a smooth equal distribution of the flow inside the treatment chamber.
FIGS. 6 and 7 illustrate 2 specimen carrier inserts 3, which can be mounted selectively. The embodiment illustrated in FIG. 6 is intended for receipt of a textile roll having a rigid material specimen carrier bush 60 (at the left hand of the fig.) or a flexible material specimen carrier bush 61 having an adjustable height. The specimen carrier bush includes perforations for the through flow of the treatment liquid. It is supported by means of a closed distance holder tube 62 adapted to conform to the height of the respective bush and via a sealing ring 63. Accordingly the height of the roll (spool) can be accordingly selected by maintaining the same displacement body 18. A flow bush 64 which is open at its top is provided at the outside of the specimen supporting bush 60,61 which bush 64 extends roughly up to the height of the specimen carrier bush or the roll, respectively. Accordingly, the flow path of the treatment liquid is definitely defined. The returning of the flow from the central inlet 8 to the cylinder 4 does not proceed in and through the specimen roll but rather through the flow tube (see FIG. 4) such that less turbulances are generated which could lead to unwanted differences of the flow speed and temperatures, respectively through the roll of the specimen. The equal temperature distribution across the roll is generated further by a temperature exchange effect specifically in case of rolls having a large diameter or if the height of the roll extends above the directly heated height of the cylinder 4. The flow bush 64 is exchangeable and can be adjusted to the hight the roll. It secures an excellent reproduceabilty of the test results.
According to a alternative design the specimen carrier insert 3 may be structured as basket such as illustrated in FIG. 7. This basket 65 comprises at the bottom and at the top a perforated wall 66, 67 and is closed laterally by a bush 68 which defines a volume of the basket. The treatment liquid flows through the basket, that is through the textile material contained therein from the bottom to the top or vice-versa. Because the volume of the basket is set by the prevailing height of the bush a reproduceable density of the textile material is achieved. Differing volumes can be arrived at by a suitable selecting of the height of the bush.
By means of the laboratory apparatus described above, the apparatus is provided by means of which a broad range of tests can be covered by using a small member of exchange parts only. The flow and temperature conditions defined clearly at all applications allow to conduct tests having a excellent reproduceability and an exact realism.
Whilst there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims: | A specimen carrier is located in a clearly defined flow path of a treatment liquid in a treatment chamber. This treatment chamber is integrated with a conveying unit to one structural unit. For a realistic representation of the treatment operation the conveying unit comprises a pump having a rotating conveyor part for generating a non-pulsating flow. This flow can thereby be reversed by a reversal of the sense of rotation of the conveying part. | 3 |
BACKGROUND OF THE INVENTION
The invention relates to apparatus for the extraction of vapour from a mash and/or wort tub in which the vapour is guided under the control of a valve via a tub vapour condenser or a vapour vent pipe arranged as a bypass to the tub vapour condenser.
Apparatus of this type with alternative guiding of the vapour makes it possible in those instances in which part of the heat energy of the vapour is to be recovered in a condenser by heating water, as well as in those instances in which the heat recovery to be dispensed with (for instance when the temperature of the vapour is not sufficient for heating water or when no hot water is needed for operational reasons).
In known constructions of this type a tub vapour condenser is arranged at the side of a vapour vent pipe and the vapour is guided as a rule under the control of two valves (one in the vapour vent pipe and one in the pipe leading to the tub vapour condenser). A particular disadvantage of this known construction is that it requires a large amount of space. In many cases this precludes the possibility of equipping existing plant with such an alternative vapour guiding arrangement at a later stage.
SUMMARY OF THE INVENTION
An object of the invention is to avoid the disadvantages of known apparatus and to provide apparatus distinguished by a particularly simple construction requiring little space, thereby enabling it to be installed at a later stage without difficulty in existing plant.
This object is achieved according to the invention by the following features:
(a) The tub vapour condenser is constructed as a helical tube condenser and is arranged coaxially around the vapour vent pipe;
(b) a valve is provided in the region of the lower end of the vapour vent pipe.
If the tub vapour condenser is arranged as a helical tube condenser around the vapour vent then an extremely simple vapour guiding arrangement is provided when the condenser is connected to the flow path.
For this purpose at the lower end of the vapour vent pipe the vapour coming from the tub merely has to be guided somewhat outwards into the annular flow chamber surrounding the vapour vent pipe. If then passes through the condenser while maintaining its substantially vertical flow and is then brought together again at the upper end of the central vent pipe forming the bypass to the condenser. The vapour vent pipe thus forms the inner boundary wall of the flow chamber containing the vapour in the region of the condenser. The outer boundary wall of this flow chamber is formed by a tubular housing the diameter of which is only slightly greater than the diameter of the vapour vent pipe. Thus the apparatus according to the invention has the advantage that it requires a particularly small amount of space and has a very simple construction; it therefore can be installed at a later stage, i.e., retrofitted, without difficulty even in existing plant where space is restricted.
In this construction it is necessary to make use of a single valve only, which is arranged in the region of the lower end of the vapour vent pipe. When the valve is closed the vapour passes exclusively through the helical tube condenser. When the valve is open, on the other hand, almost all of the vapour passes through the vapour vent pipe since the helical tube condenser constitutes a much greater flow resistance for the vapour than does the vapour vent pipe. The use of one single valve to control the vapour flow simplifies the construction and thus contributes to a reduction in the cost of construction.
DESCRIPTION OF THE DRAWINGS
Two embodiments of the invention are illustrated in the accompanying drawings, wherein:
FIG. 1 is a partly elevational, partly sectional, simplified view of a first embodiment of the apparatus; and
FIG. 2 is a fragmentary view similar to FIG. 1, but illustrating a modified embodiment.
DETAILED DESCRIPTION
The apparatus 1 has a tubular outer housing 2 which comprises a substantially cylindrical peripheral wall 3, a (lower) housing base 4, a cover 5 in the form of an inverted truncated cone, and a vapour extraction pipe 6 which is connected approximately at the top of the cover and can be connected or flanged onto an extension pipe which is not shown. At the lower end of the outer housing 2 is a vapour delivery pipe 7 which projects axially through the housing base 4 into the interior of the housing 2. This delivery pipe 7 is preferably of cylindrical construction, arranged coaxially with the peripheral wall 3, and has at its lower end a flange that can be connected to a vapour extraction pipe, not shown, of a mash and/or wort tub.
A vapour vent pipe 8 which is of cylindrical construction and extends over the greater part of the length or height of the cylindrical peripheral housing wall 3 is arranged coaxially (cf. longitudinal axis 2a of the housing) inside the tubular outer housing 2. The lower end 8a of the vapour vent pipe is spaced from the upper end 7a (extending inside the housing) of the vapour delivery pipe 7 by a distance SA. In the region of its lower end 8a the vapour vent pipe 8 has a shut-off valve 9 which can be pivoted about an axis 10 of rotation in the direction of the two-headed arrow 11 in such a way that the lower end 8a of the vapour vent pipe can be opened or closed (naturally intermediate positions are also possible); this movement of the shut-off valve 9 can of course be carried out manually or mechanically.
A substantially cylindrical annular chamber 12 is provided between the peripheral housing wall 3 and the vapour vent pipe 8, the cross-section of the annular chamber being of such a size that a vapour tub condenser constructed as a helical tube condenser 13 can be received and arranged there. This tube condenser 13 is thus arranged coaxially around the vapour vent pipe 8 and in the illustrated embodiment it comprises concentric coils 13a, 13b of the pipe which are arranged coaxially one inside the other. The two coils of pipe are radially spaced relative to each other and to the respective adjacent walls (peripheral wall 3 on the one hand and vapour vent pipe wall on the other hand) and extend over the greater part of the height of the vapour vent pipe 8. Depending upon the structural size and the desired capacity it is of course also possible to construct the tube condenser 13 with only one pipe coil or with more than two pipe coils. In each case, however, a supply 14 of fluid, such as cold water, is provided in the region of the upper end of the apparatus 1 and thus at the upper end of the tube condenser 13, while at the lower end a discharge pipe 15 is provided for the heated water or other fluid.
There are essentially two different ways of operating the apparatus shown in FIG. 1. If it is assumed that the vapour delivered via the delivery pipe 7 is to be led over the tub vapour condenser pipe coil or coils 13, then the shut-off valve 9 is closed as shown in the drawing. Because of the sufficiently large axial distance SA between the adjacent ends of the delivery pipe 7 and the vapour vent pipe 8 the vapour may enter the annular chamber 12 and is there guided upwards in a substantially vertical direction (arrow 16) and thus over the tub vapour condenser coils 13. Since there is also a sufficiently large distance between the upper end 8b and the cover 5 in the upper part of the apparatus 1, the vapour can escape upwards unhindered through the extraction pipe 6. There thus is no need to provide a shut-off valve or the like in the region of the upper end 8b of the vapour vent pipe 8.
If the vapour delivered via the delivery pipe 7 is to be led through the apparatus 1 in the bypass to the tub vapour condenser coils 13, then it is sufficient merely to open the shut-off valve 9 so that the vapour finds its way (because of the lower flow resistance) upwards through the vapour vent pipe 8 (cf. broken arrow 16a). Since the diameter of the vapour delivery pipe 7 is somewhat smaller than that of the vapour vent pipe 8 the bypass arrangement explained immediately above is further favored.
In order for condensate collecting in the lower part of the apparatus or in the base region of the housing 2 to be led off, a condensate discharge pipe 17 which is constructed as a pipe connection and can optionally be equipped with a shut-off valve (not shown) is provided in the region of the housing base 4.
For effective heat exchange between the vapour and the cold water flowing in the tub vapour condenser coils 13 it is also particularly advantageous if the condenser, and in particularly the pipe coils 13a and 13b thereof, can be cleaned from time to time. For this purpose an annular spray line 18 for cleaning fluid may be provided in the annular chamber 12 between the vapour vent pipe 8 and the peripheral housing wall 3 above the condenser 13. This spray line can have an outer delivery connection 19 and can be operated periodically. In this case a discharge connection 20 through which used cleaning fluid can be led off is provided in the housing base 4. This discharge connection 20 can be normally closed (when the cleaning arrangement is out of operation) by a conventional valve (not shown) in the region of the housing base 4 so that no condensate flows off through the connection 20.
In the embodiment of FIG. 2 the upper part of the apparatus 21 can be constructed in the same manner as the embodiment to FIG. 1. For the sake of simplicity parts of the apparatus in FIG. 2 which essentially correspond to those of FIG 1 are provided with the same reference numerals modified by prime so that a detailed description thereof is superfluous.
Thus, in the embodiment of FIG. 2 the tub vapour condenser 13' has helical coils arranged coaxially around the vapour vent pipe 8'. The vapour vent pipe 8' can be opened opened and closed, as explained above, by the valve 9' provided in the region of the lower 8a' of the vapour vent pipe 8'. The inner end 7a' of the vapour delivery pipe 7' which projects from below into the housing 2' terminates at a distance below the lower end 8a' of the vapour vent pipe 8'.
In the embodiment according to FIG. 2 an annular condensate collecting chamber 22 is constructed in the lower part of the housing 2' of the apparatus between the peripheral housing wall 3' and the wall 7b' of the vapour delivery pipe 7' inside the housing. Depending upon the desired size or height of this condensate collecting chamber 22 the wall 7b' of the vapour delivery pipe 7' inside the housing can have a corresponding axial length. The condensate running or dripping from the condenser 13' is to be collected in this condensate collecting chamber 22 up to a level 23 which lies somewhat below the inner end 7a' of the vapour delivery pipe 7'. This level can be adjusted or maintained as desired with the aid of a suitable level regulating arrangement. In the illustrated embodiment a siphon pipe 24 connected to the condensate discharge pipe 17' is provided as level regulating means.
A heat exchanger 25 inside the condensate collecting chamber 22 and, as shown is preferably constructed in the same way as the tube condenser 13', and is arranged around the part 7b' of the vapour delivery pipe 7' inside the housing coaxially therewith. The upper end of the heat exchanger terminates below the condensate level 23, as a consequence of which the heat exchanger 25 is always immersed in fluid condensate. With the aid of the heat exchanger 25 the residual heat still contained in the condensate can be recovered for use, for example, in preheating cold water which is delivered at the lower end of this heat exchanger by a cold water delivery pipe 26. A water discharge pipe 27 is provided at the upper end of the heat exchanger 26.
The heat exchanger 25 also can be used particularly advantageously to preheat the fluid, e.g. cold water, to be delivered to the tube condenser 13'. In this case, as is indicated by a broken line, the water discharge pipe 27 is connected to the delivery pipe to the tube condenser 13' which is not shown in greater detail in the drawing and is only represented by the reference numeral 14'.
In contrast to the first embodiment in which the diameter of the vapour delivery pipe 7 is smaller than that of the vapour vent pipe 8, the vapour delivery pipe 7', as shown in FIG. 2, can have the same diameter as the vapour vent pipe 8' so that the same installation conditions (in the corresponding annular chambers) are provided for the tube condenser 13' and the heat exchanger 25.
The FIG. 2 embodiment of the vapour extraction apparatus may be used most advantageously where vapour delivered via the pipe 7' still has a relatively high heat content. | Apparatus for the extraction of vapor from a brewing tub enables the vapor to be guided selectively under the control of a valve either via a tub vapor condenser or a vapor vent pipe arranged as a bypass to the tub vapor condenser. A particularly space-saving construction which enables retrofitting an existing plant comprises a helical tube condenser arranged around the vapor vent pipe having the control valve in the region of its lower end. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60/627,491, filed Nov. 12, 2004; and U.S. Utility application Ser. No. 11/270,944, filed Nov. 10, 2005, both of the foregoing hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates generally to firearms and, more particularly, to revolvers having modified structures that are adapted for the firing of high velocity ammunition.
BACKGROUND OF THE INVENTION
[0003] High velocity ammunition is well known for use in rifles and other long guns. Ammunition of this type is characterized by muzzle velocities in excess of 2,500 feet per second (fps). Handguns, however, have not been capable of muzzle velocities of this magnitude, and have an upper bound of about 1,500 fps. Revolvers present the added challenge of a barrel-cylinder (BC) gap to allow for cylinder rotation. In such revolvers, the hot gases generated by the ignition of the powder are vented out the cylinder and down the barrel, with some venting at the BC gap, with a concomitant loss of pressure and bullet velocity. The BC gap must be established and uniformly maintained between the forward-most surface of the chamber and the rearward-most surface of the barrel to ensure that proper cylinder pressures are maintained during firing. In revolvers in which the barrels are threaded to the frame so as to extend through a rearward-facing portion of the frame, methods for setting the BC gap include broaching the rearward surface of the barrel after the barrel is threaded into the frame. This broaching method produces tool marks on the end surface of the barrel adjacent the cylinder and oftentimes mars the finish of the barrel.
[0004] The use of high velocity ammunition causes a more powerful and intense release of the high-pressure gases from the cartridge casings upon firing. Correspondingly, a greater acceleration of the bullet from the cartridge is realized with the projectile traveling from the cylinder across the BC gap to the barrel. The greater force necessary to achieve muzzle velocities in the range of 2,500 fps generates forces of a magnitude that can cause cartridge brass to flow in a rearward direction and somewhat increased bullet deformation. Standard geometries at the rearward end of the barrel (at which the bullet enters) include tapered or chamfered surfaces to facilitate the engagement of the deformed projectile. Standard constant twist rifling allows the projectile to be sufficiently engaged and longitudinally rotated at a constant rate as the projectile traverses the length of the barrel.
[0005] Certain high-powered revolvers have a shroud placed over the barrel and can therefore have a releasably secured sight assembly mounted at the forward end of the shroud. Such sight assemblies usually employ known mounting arrangements to ensure proper sight alignment and positive sight retention. These replaceable sight assemblies generally comprise sights with a dovetail base that are urged by springs in the forward direction such that forward edges of the sights engage laterally-positioned mounting pins. With this releasable sight configuration, there sometimes is displayed an undesirable lateral shift or drift of the laterally-positioned pin due to the forces associated with high velocity ammunition. In such cases, the sights correspondingly shift with the laterally-positioned mounting pins.
[0006] What is needed is a revolver firearm that is capable of reliably firing high velocity ammunition and that addresses these and other special circumstances found with operating a handgun in this extreme range of muzzle velocities.
SUMMARY OF THE INVENTION
[0007] An embodiment of the present invention relates to a firearm for firing high velocity ammunition, provided in the form of a revolver that includes a frame, a cylinder, a firing mechanism, and a barrel, all of which are operably interconnected in a manner similar to a standard revolver. For example, the cylinder is pivotally mounted in the frame and includes a plurality of chambers configured to receive and align cartridges with the barrel, while the firing mechanism includes a trigger and a hammer, wherein upon a user pressing the trigger in a rearward direction, the hammer is operated to discharge a cartridge loaded into one of the chambers.
[0008] One advantage of the revolver of the present invention is that a space between a rearward portion of the barrel and a forward surface of the cylinder can be adjusted longitudinally within a shroud housing the barrel from a forward end of the barrel. Such adjustment is typically effected by the use of one or more spacers. By allowing the position of the barrel to be adjusted in such a manner, the need to broach the rearward surfaces of the barrel is eliminated.
[0009] Another advantage is that the barrel is provided with a forcing cone integrally formed at the rearward opening thereof. The forcing cone (and/or the rear surface of the barrel) can be polished or otherwise finished to provide a reflective surface that reduces the amount of erosion that can result from using the revolver with high velocity ammunition. Thus, because the surface of the cone is subject to less erosion, the barrel life of the handgun can be extended. Furthermore, the geometry of the surface of the cone in conjunction with the reflective finish allows the projectile of the high velocity ammunition to show a smoother translation across the BC gap, thereby showing improved performance results in the revolver.
[0010] Another advantage of the present invention is the use of gain-twist rifling in the barrel that allows for a more gradual engagement of the high velocity projectile with the rifling and further allows for a smoother transition to the full velocity of the projectile as the projectile exits the barrel. Moreover, by using a preferred electrochemical process to produce the rifling, variations in land width and profile, as well as a smoother transition to the full twist rate, can be realized.
[0011] Yet another advantage of the present invention is the optional provision of a larger diameter, hardened firing pin bushing that allows for improved support at the head of the cartridge casing. By utilizing a larger bushing (e.g., a bushing in which the diameter thereof is at least as large as the casing head), brass flow in the rearward direction may be minimized when high velocity ammunition is fired.
[0012] Still another advantage of the present invention is an interchangeable front sight assembly with a lateral locating pin having a dumbbell-shaped configuration. Such a configuration minimizes lateral shift or drift of the sight pin during the firing of high velocity ammunition from the handgun.
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIG. 1 is a simplified schematic representation of a handgun made in accordance with the present invention.
[0014] FIG. 2 is a perspective view of a cylinder and ejector of the handgun of FIG. 1 .
[0015] FIG. 3 is a simplified schematic representation of the handgun of FIG. 1 in exploded cutaway view.
[0016] FIGS. 4 , 4 A, and 5 are simplified schematic representations of the handgun of FIG. 1 in cutaway view.
[0017] FIG. 6 is a simplified schematic representation of a barrel of the handgun of FIG. 1 showing a forcing cone.
[0018] FIG. 7 is a simplified schematic representation of a barrel of the handgun of FIG. 1 showing gain-twist rifling.
[0019] FIG. 8 is a perspective view of a portion of a frame of the handgun of FIG. 1 .
[0020] FIG. 9 is a perspective view of the frame of the handgun of FIG. 8 showing a firing pin bushing mounted in a yoke of the frame.
[0021] FIG. 10 is a perspective view of the firing pin bushing of the handgun of FIG. 9 mounted in the yoke of the frame and shown in cutaway view.
[0022] FIGS. 11 and 12 are perspective views of the firing pin bushing for a revolver made in accordance with the present invention.
[0023] FIG. 13 is a side elevation view of the frame and firing pin bushing of FIG. 9 .
[0024] FIG. 14 is a side elevation view of a front sight assembly on the forward end of the barrel of a revolver made in accordance with the present invention.
[0025] FIG. 15 is a perspective view of the front sight assembly of FIG. 14 .
[0026] FIGS. 16 and 17 are perspective and side elevation cross-section views, respectively, of a bushing-less, hardened frame according to an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Referring to FIG. 1 , one exemplary embodiment of a firearm incorporating the present invention is shown generally at 10 and is hereinafter referred to as “firearm 10 .” The firearm 10 is preferably a revolver (as described in U.S. Pat. Nos. 6,330,761 and 6,523,294, which are incorporated herein by reference) that includes a frame 12 , a cylinder 14 , a firing mechanism 16 , and a barrel 18 . A firing axis 19 extends coaxially with the barrel 18 . High velocity ammunition is the preferred type of ammunition for use in the firearm 10 , such ammunition typically being capable of attaining bullet muzzle velocities of about 2,500 feet per second or greater.
[0028] The cylinder 14 is pivotally mounted in the frame 12 and includes an ejector 20 , a ratchet 22 , and a plurality of chambers, two of which are shown at 26 . The chambers 26 are configured to receive and align cartridges with the barrel 18 . The cylinder 14 is pivotally mounted on a yoke 28 that is attached to the frame 12 . A top strap 29 extends across a top portion of the frame 12 from a forward portion to a rearward portion to define a generally rectangular aperture. When the cylinder 14 is closed with respect to the yoke 28 , the cylinder 14 is positioned in the rectangular aperture such that a chamber 26 of the cylinder 14 is longitudinally aligned with the barrel 18 . A retaining mechanism 30 maintains the cylinder 14 within the rectangular aperture. A cylinder release bar actuated by a thumb piece 36 allows the cylinder 14 to be rotated out of the rectangular aperture into a cylinder-open position.
[0029] The firing mechanism 16 includes a trigger 40 and a hammer 42 . Upon a user pressing the trigger 40 in a rearward direction, the hammer 42 is operated to discharge a cartridge loaded into the firearm 10 .
[0030] Referring now to FIG. 2 , the ejector 20 includes a rod 21 about which the cylinder 14 rotates. The ratchet 22 is attached at a rearward end of the rod 21 and has a plurality of detent or cut out portions 25 that correspond to the respective rearward edges of each chamber 26 . The ratchet 22 is dimensioned such that it is received in a recess at the rear surface of the cylinder 14 so as not to obstruct the rotation of the cylinder 14 on the yoke 28 or the opening and closing of the cylinder 14 in the rectangular aperture. Upon loading a cartridge into any chamber 26 , a rim on a base of the casing of the cartridge engages the cut out portion 25 of the ratchet 22 . To eject cartridges from the cylinder 14 , the firearm is placed in the cylinder-open position and a forward end of the rod 21 is urged in the rearward direction. The defining edges of each cut out portion 25 engage the rims of the casings, and the casings are pulled out of the rear of the cylinder 14 .
[0031] Referring now to FIGS. 3-5 , the barrel 18 is mounted in a shroud 44 attached to a forward portion of the frame 12 . (The shroud 44 may be considered part of the frame 12 , i.e., part of the support structure of the firearm.) The barrel 18 comprises an elongated, substantially cylindrical member having a cylindrical bore 46 extending longitudinally there through. The surfaces of the barrel 18 , namely, the rearward-most edge surface at which the projectile enters the barrel and the wall of the cylindrical bore 46 , are polished or otherwise finished to provide a reflective surface such that the hot gases generated during the firing of ammunition are less likely to have an effect on the barrel surfaces. For example, the reflective surface may be a highly reflective surface (by which it is meant a surface with a reflectance or albedo of at least 0.85) or a mirrored surface (a reflectance/albedo of at least 0.95). Upon assembly of the revolver, the cylindrical bore 46 registers with the respective chambers 26 of the cylinder 14 and forms the longitudinal firing axis 19 .
[0032] The clearance between the forward-most surface of the cylinder 14 and the rearward-most surface of the barrel 18 is the barrel-cylinder (BC) gap. The barrel 18 is mounted in the shroud 44 using a spacer 48 positioned at a forward end of the barrel 18 to give the desired BC gap (see FIG. 4A for a detail view). The spacer 48 , which may be annular-shaped, washer like device, is positioned against a flange 50 on the shroud 44 . The fore end of the barrel 18 may also be provided with a flange 51 for abutting the spacer 48 when the firearm 10 is assembled. Alternatively, the spacer 48 may be removably connected to the barrel in a standard manner. The width of the spacer 48 is selected to give the desired BC gap. Alternatively, two or more spacers 48 can be stacked together on the barrel 18 to adjust the BC gap. Thus, because the BC gap is adjusted via the spacer(s) 48 , the threading of the barrel into the frame and the broaching operation in which the rearward portion of the barrel is cut off (potentially marring the polished barrel surface) is avoided. A muzzle brake 52 ( FIG. 5 ) fits over the forward end of the barrel 18 and is positioned in the shroud 44 . The muzzle brake 52 is held in the shroud 44 using a screw 54 or similar device.
[0033] Referring now to FIG. 6 , a forcing cone 60 is integrally formed with the barrel 18 at the rearward opening thereof. The forcing cone 60 , which accommodates for the deformation of the projectile as the projectile traverses the BC gap, comprises a rearward edge 62 that is defined by the perimeter of the rearward opening of the barrel 18 . The forcing cone 60 extends radially inward toward the firing axis 19 to terminate at the inner wall 64 of the barrel 18 . Thus, the forcing cone 60 has a slightly larger entry diameter as compared to the central bore diameter of the barrel 18 , thereby providing a clearance between the cylinder and the barrel 18 to facilitate movement of a projectile (e.g., bullet) from the cylinder to the barrel 18 . In particular, the slightly larger entry diameter of the forcing cone 60 enables the projectile to enter the barrel 18 with a reduced probability that the projectile will engage a rearward-facing surface 66 of the barrel 18 .
[0034] The rearward edge 62 of the forcing cone 60 is configured to have a radius (e.g., it is rounded) to further facilitate the movement of the projectile from the cylinder into the forcing cone 60 . A forward edge 68 of the forcing cone 60 may be likewise configured to have a radius to even further facilitate the movement of the projectile from the forcing cone 60 to the barrel 18 . A wall 70 of the forcing cone 60 adjacent the rearward edge 62 may be provided with a reflective finish (e.g., a highly reflective or mirrored surface) to allow hot gases to flow more smoothly and to reduce the opportunity for the surface of the forcing cone 60 to erode.
[0035] Referring now to FIG. 7 , lands 74 and grooves 76 are disposed on an inner wall 78 of the cylindrical bore 46 of the barrel 18 to form gain-twist rifling. Gain-twist rifling is characterized by a twist rate (turns per unit distance) that varies along the length of the barrel from a slow twist at the breech/rear end of the barrel to a tighter twist at the muzzle/fore end of the barrel, e.g., from a slow rate such as one twist per 100 inches to a higher rate such as one twist per 20 inches. The gain-twist rifling of the present invention may be produced on the inner wall 78 using an electrochemical process that produces rifling in which the width of the lands 74 increases as the twist rate increases, thereby allowing more of the bullet surface to be engraved as the bullet traverses the length of the barrel 18 . Essentially, as the lands get wider, the bullet is gripped tighter as it spins faster. This is different from conventional grain-twist rifling, where the full land and groove profiles are engraved initially, and then the twist rate is increased. One exemplary electrochemical process for producing rifling in gun barrels is disclosed in U.S. Pat. No. 5,819,400, which is incorporated herein by reference in its entirety. Gain-twist rifling lessens the abrupt transition from zero angular velocity to the nominal or maximum angular velocity. The smoother transition up to the nominal or maximum angular velocity has been found to increase accuracy by minimizing bullet deformation as it engraves the rifling. Furthermore, users may feel less recoil torque because of the bullets' smoother transition to maximum angular velocity.
[0036] As noted, the lands 74 closest to the breech end of the barrel (near the forcing cone 60 ) may be smaller in width. The edges of these lands will typically not be as sharp as those of the lands further down the barrel where the twist rate is increased. In particular, the edges of the lands proximate to the forcing cone may be provided with smoother or more rounded edges, as a result of the electrochemical process or otherwise. This results in a reduction of bore erosion ahead of the forcing cone.
[0037] Referring now to FIGS. 8-13 , the firearm also incorporates a firing pin bushing 80 having a diameter (or other widest dimension if the bushing is non-circular) that meets or exceeds the diameter of the head of the cartridge casing used in the handgun. As is shown in FIG. 8 , the firing pin bushing 80 is mounted in a recess 82 in a forward-facing, bolster face portion 81 of the frame 12 . The recess 82 is defined by a first vertical surface 84 , a first land 86 , a second vertical surface 88 , and a second land 90 . A chamfered rim 89 defines the edge between the first land 86 and the second vertical surface 88 . The lands and vertical surfaces of the recess 82 are sufficient to accommodate the firing pin bushing 80 with a degree of precision such that the firing pin bushing 80 can be mounted with a minimum amount of angular displacement from the flush surface of the bolster face 81 at the upper portion thereof. Referring to FIG. 9 , a lower portion of the firing pin bushing 80 extends into a cavity or recess 91 in the bolster face 81 .
[0038] Referring now to FIGS. 11-13 , the firing pin bushing 80 comprises a primary member 92 having a planar front face 94 , a firing pin aperture 96 drilled, bored, machined, cast, or otherwise formed in the center of the primary member 92 so as to extend therethrough, and a seating member 98 extending from a rearward face 100 of the primary member 92 . The primary member 92 may be disc- or plate-shaped, i.e., shaped akin to a washer or squat cylinder, and the seating member 98 is preferably generally cylindrical in shape and concentrically positioned relative to the firing pin aperture 96 .
[0039] The width dimension of the front face 94 is at least as great as the diameter of a cartridge casing head used in the firearm to prevent brass flow during the use of high-pressure ammunition. As can be best seen in FIGS. 11 and 13 , the perimeter of the front face 94 has a radius, i.e., its outer edge is rounded. The perimeter of the rearward face 100 ( FIGS. 12 and 13 ) is chamfered to facilitate the insertion of the firing pin bushing 80 into the recess. A transition surface 104 between the rearward face 100 and the outer wall of the seating member 98 is concavely radiused to provide a space between the chamfered rim 89 and the firing pin bushing 80 . The rearward-most edge of the seating member 98 is chamfered at an angle of about 30 degrees to even further facilitate the insertion of the firing pin bushing 80 into the recess. As can best be seen in FIG. 13 , the diameter of the aperture of the seating member 98 is greater than the diameter of the firing pin aperture. The aperture of the seating member 98 registers with a bore 108 in the yoke 28 through which the firing pin (not shown) translates to extend through the firing pin aperture 96 to engage a cartridge.
[0040] Referring to FIG. 14 , the firearm incorporates a front sight assembly 120 that is mountable into the shroud 44 . The sight assembly 120 of the present invention is an improvement on the sight assembly of U.S. Pat. No. 5,802,757, which is incorporated herein by reference in its entirety. The sight assembly 120 of the present invention includes a sight 123 having a sight pin portion 121 and an anchor portion 122 . The anchor 122 is attached to or connected to the sight pin 121 via a connector 124 , which is of a lesser width-wise dimension than either the sight pin 121 or the anchor 122 . The anchor 122 is received in a slot 126 on the uppermost surface of the forward portion of the shroud 44 . The anchor 122 and the receiving slot 126 extend longitudinally in the direction of the longitudinal firing axis of the firearm. In mounting the sight 123 , the anchor 122 is press-fitted into the receiving slot 126 such that the connector 124 and the anchor 122 engage a laterally mounted dumbbell-shaped pin 125 that is positioned across the receiving slot 126 perpendicular to the direction in which the slot 126 and the longitudinal firing axis extend. A spring 130 mounted in the rearward portion of the receiving slot 126 is configured to urge the anchor 122 (and, accordingly, the connector 124 and the sight 121 ) in a forward direction against the dumbbell-shaped pin 125 .
[0041] Referring now to FIG. 15 , the dumbbell-shaped pin 125 comprises a dowel-shaped connection member 131 , a first protrusion 132 attached to a first end of the connection member 131 , and a second protrusion 134 attached to a second end of the connection member 131 . A forward surface of the connector is substantially vertical and perpendicular to the longitudinal firing axis when the sight 123 is mounted in the shroud. A forward surface of the anchor 122 is tapered such that when the connector 124 and the anchor 122 are attached to each other or integrally formed, an angle A is defined. Upon urging the anchor 122 and the connector 124 against the dumbbell-shaped pin 125 , the dowel-shaped connection member 131 is received in a vertex of the angle A. The first protrusion 132 and the second protrusion 134 capture the anchor 122 and the connector 124 there between, thereby facilitating the retention of the sight assembly 120 in place.
[0042] FIGS. 16 and 17 show a “bushing-less” frame 140 according to an alternative embodiment of the present invention. The frame 140 is not provided with an enlarged firing pin bushing 80 (as shown in FIGS. 8-13 ) or other type of firing pin bushing. Instead, the frame 140 has a firing pin aperture 142 formed directly in the frame and extending there through, and the area 144 of the frame around the aperture (e.g., the bolster face 81 ) is hardened using standard methods. Optionally, the entire frame 140 may be hardened. As should be appreciated, traditional firing pin bushings present a “seam” in the bolster face proximate the casing head, as between the bushing and frame. With high velocity ammunition, the brass casing may start to flow into the seam, jamming the cylinder. With the enlarged bushing 80 , the seam is moved away from the casing head. With the bushing-less frame 140 , the seam is eliminated entirely.
[0043] Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of the above disclosure. | A revolver for firing high velocity ammunition includes a frame, a cylinder, a barrel, and a firing mechanism. The revolver may include one or more of the following, each of which is especially adapted for use in the context of firing high velocity ammunition: spacers for adjusting a barrel-cylinder gap, for eliminating broaching of the rearward surface(s) of the barrel; a forcing cone formed in the rearward opening of the barrel for accommodating deformed projectiles; a reflective surface (e.g., mirrored surface) provided on the cone and/or barrel rearward surfaces, for reducing erosion resulting from using high velocity ammunition; gain-twist rifling in the barrel for a smoother transition to full projectile velocity; a larger diameter, hardened firing pin bushing for minimizing brass flow in the rearward direction; and a front sight assembly that minimizes lateral shift or drift of the sight pin during firing. | 5 |
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